Restricted lateral mobility of plasma membrane CD4 impairs HIV-1 envelope glycoprotein mediated fusion. We investigated the effect of receptor mobility on HIV-1 envelope glycoprotein (Env)-triggered fusion using B16 mouse melanoma cells that are engineered to express CD4 and CXCR4 or CCR5. These engineered cells are resistant to fusion mediated CD4-dependent HIV-1 envelope glycoprotein. Receptor mobility was measured by fluorescence recovery after photobleaching (FRAP) using either fluorescently-labeled antibodies or transient expression of GFP-tagged receptors in the cells. No significant differences between B16 and NIH3T3 (fusion-permissive) cells were seen in lateral mobility of CCR5 or lipid probes. By contrast CD4 mobility in B16 cells was about seven-fold reduced compared to its mobility in fusion-permissive NIH3T3 cells. However, a CD4 mutant (RA5) that localizes to non-raft membrane microdomains exhibited a three-fold increased mobility in B16 cells as compared with WT-CD4. Interestingly, the B16 cells expressing the RA5 mutant (but not the wild type CD4) and coreceptors supported HIV-1 Env-mediated fusion. Our data demonstrate that the lateral mobility of CD4 is an important determinant of HIV-1 fusion/entry.


Predictability of conjunctival-Müellerectomy for blepharoptosis repair. To assess the predictability of the algorithm used to determine the amount of tissue resection for conjunctival-Müellerectomy during blepharoptosis repair. A consecutive case series of all patients undergoing conjunctival-Müellerectomy during blepharoptosis repair between July 2001 and February 2005. All of the cases had a positive phenylephrine test, and the mean preoperative upper marginal reflex distance (MRD1) was +1.60 mm (range: -1 +/-3.5 mm). Each patient underwent excision according to the following algorithm: 10 mm of resection for 2 mm of ptosis, 8 mm of resection for 1.5 mm of ptosis, and 6 mm of resection for 1 mm of ptosis. Fifty-five patients underwent conjunctival-Müellerectomy during blepharoptosis repair on 73 eyelids, using the above algorithm. Thirty-seven cases were unilateral and 18 were bilateral. The mean postoperative MRD1 was +3.42 mm (range 0-+4.5 mm). Postoperative symmetry was found in 42 of 55 patients (76.4%) after one surgical procedure. Patient satisfaction based on contour, symmetry and height after one repair was achieved in 52 of 55 patients (94.55%). There were three reoperations for previous undercorrection. This algorithm quantifies conjunctival-Müellerectomy during blepharoptosis repair. Excellent and very predictable results are obtained by a technique that is both simple and achievable in a short operating time.


Orbitotemporal neurofibromatosis: classification and treatment. To review the clinical findings in orbitotemporal neurofibromatosis and discuss treatment options. Clinical features, histopathologic characteristics, and treatment options are reviewed. A Medline literature search from 1966 to 2004 was performed, using the key words: orbitotemporal neurofibromatosis, orbitopalpebral neurofibromatosis, orbitofacial neurofibromatosis, cranio-orbital neurofibromatosis, and cranio-orbital-temporal neurofibromatosis, and the pertinent literature was reviewed. Additionally, our experience with two patients is reported. The surgical procedures are discussed. The management of orbitotemporal neurofibromatosis is challenging. The planned surgical approach and extent of resection depend on the severity of the orbital soft tissue and bony involvement and on the visual potential. Ultimately, orbital exenteration may be needed for rehabilitation and cosmesis.


Quantitative assessment of dacryoscintigraphic images in the evaluation of epiphora. At the present time, only visual analysis is implemented on dacryoscintigraphic images and quantitative assessments are not routinely obtained. The authors have designed a novel, simple, quantitative method for the diagnosis of sac and post-sac obstructions based on the dacryoscintigraphic images. Fifty-nine patients with severe unilateral epiphora were included and the contralateral asymptomatic eyes were used as controls. After ocular instillation of 0.1 cc isotonic saline containing 4 MBq 99mTcO4, dynamic images were obtained for 20 minutes. Visual interpretation was done by two blinded specialists in nuclear medicine. A Time-Activity Curve (TAC) was generated for each eye and its pattern was divided to plateau type, shallow-down sloping and deep-down sloping. The excretion ratio (expressed as the percentage of drained activity) in the 2nd, 3rd, 5th, 7th, 10th, 15th and 20th minute of the study was calculated based on the following formula: (the total count in the region of interest (ROI) in the 1st minute - the total ROI count in the 2nd, 3rd, 5th, 7th, 10th, 15th or 20th minute/the total ROI count in the 1st minute) x 100. The results of the quantitative analysis were compared with the clinical symptoms, visual analysis and TAC pattern. At the optimal cut-off points for the 2nd, 3rd, 5th and 7th minute, the sensitivity of the prediction of obstruction was 76%, 72%, 71% and 69%, respectively. The correlation between visual interpretation and the TAC pattern was statistically significant. The quantitative evaluation of dacryoscintigraphic images would contribute greatly to achieving an easier and more objective interpretation of the scintigraphic results and also provides a reliable tool for inter-individual comparison and the follow-up of patients. As it is the first time that this innovative method has been examined clinically, it will be necessary to investigate its clinical utility in a larger series of patients.


Overview of the lacrimal canaliculus in microscopic cross-section. Although many illustrations have been published seeking to explain the anatomy of the lacrimal canaliculus and its surroundings, to our knowledge, no micrograph showing the total length of the lacrimal canaliculus has ever been displayed. Here, we present a clear microscopic cross-section of the total length of an upper lacrimal canaliculus, except for the vertical part. A winding path was found in part of the canaliculus. The common canaliculus opened into the lacrimal sac almost perpendicularly and was covered by solid fibrous tissue. The transition between squamous cell epithelium and columnar epithelium did not always take place at the opening. There were superficial goblet cells, mucous secretory glands and intraluminal debris in the distal part of the canaliculus, including the common canaliculus, where the lining consisted of columnar epithelium. The clear overview of the structures presented here should be helpful in the treatment of the lacrimal canaliculus.


Digital subtraction dacryocystography and syringing in the management of epiphora. To compare the diagnostic information provided by digital subtraction dacryocystography (DCG) and syringing of the nasolacrimal system in patients with epiphora. Twenty-five lacrimal systems of 17 patients, who presented with unilateral or bilateral epiphora and no concurrent ocular or lid abnormality, were prospectively entered into the study. The patients initially underwent syringing by a lacrimal specialist followed by DCG. Anatomical obstructions were detected in 88% of systems with syringing and in 84% with DCG. The anatomical sites of obstruction varied between the two tests in 20% of lacrimal drainage systems. Additional useful information was provided by DCG in 28% of the cases, including identification of multiple sites of obstruction, the presence of dacryoliths, fistulae, and congenital malpositions of the nasolacrimal sac-duct junction. The two investigations were found to have comparable detection rates for anatomical obstructions. Syringing thus appears to be able to detect the problem in the majority of cases but DCG can help delineate unidentified factors of surgical significance in a selected subgroup of patients.


Patient satisfaction and results after evisceration with a split-sclera technique. A retrospective study of the postoperative results and patient satisfaction after evisceration with a split-sclera technique. The medical records of 60 patients were reviewed. All patients were operated by evisceration with a split-sclera technique and placement of an orbital implant. The patients were operated by the same surgeon between 1995 and 2003. Multiple-choice questionnaires were sent to the patients, and the patients were also offered a clinical examination. Extrusion/exposure of the implant was seen in 3/62 (4.8%) orbits. Migration of the implant was seen in one patient. At the time of the study, 45/60 patients were still alive, 32 of these answered the questionnaire. In a question about the patient's psychological well-being after the operation, 9/32 (28%) answered that they had felt depressed; four of these had had a recent trauma to the eye resulting in the evisceration; 25/32 (78%) patients were pleased or very pleased with the operation. A clinical examination was performed in 31 patients. The motility of the prosthesis and implant was measured and found to be rather poor (mean between 2.5 to 4.1 mm in each direction); however, most patients judged their motility to be good or excellent. Evisceration with a scleral split modification has been used successfully in our clinic since 1995. The risk for exposure is low, 3/62 (4.8%). Postoperative depression was common (9/32). Recent trauma was a risk factor for postoperative depression.


The switch flap in eyelid reconstruction. Full-thickness eyelid defects are conventionally reconstructed by either a Hughes flap or a Cutler-Beard bridge flap. The switch flap is an alternative method and is not very widely practiced. The author has used this method for repair of large full-thickness eyelid defects and describes her experience with the use of this technique. Eight cases of large full-thickness eyelid defects resulting from excision of tumours such as basal cell carcinoma (bcc), squamous cell carcinoma (scc) and sebaceous gland carcinoma (sgc) were taken for repair using the switch flap technique. The technique involves switching a full-thickness flap on a pedicle to fill a defect from lower lid to upper or vice versa. The pedicle is divided in three weeks. The recipient lid is reconstructed by direct closure and the donor lid by direct closure with or without cantholysis or sliding flap, or it is left to heal by second intention. The patients were followed up frequently in the first few weeks according to need, at six months, and then every year for five years before discharge. At these visits, contour of lid, condition of wound, cornea and donor site were examined for infection, dehiscence, corneal ulcer, notching, trichiasis, and recurrence. The preoperative and postoperative photographs were also compared. Out of the eight cases of eyelid defects, one was from squamous cell carcinoma, three were from sebaceous gland carcinoma, and four were from infiltrative basal cell carcinoma. Using the switch flap technique, the defects resulting from their excision were completely covered in all cases. The main complication was a corneal ulcer in cases 1 and 3 where the flap had crossed the central cornea. A bandage contact lens was inserted until the division of the flap. The main morbidity was the blurred vision until the flap is divided, especially in the cases of reduced vision in the other eye. At about 4-6 weeks post flap division, the recipient and donor sites have healed completely, even when the donor lid was left to heal by second intention (case 4). There was no trichiasis, notching or notable deformity, and the morbidity was minimal. A comparison between preoperative and postoperative photographs shows satisfactory results with the switch flap technique. The author has found the switch flap technique very useful for reconstruction of large full-thickness eyelid defects resulting from tumour excision as this method results in complete repair of defects with a full-thickness flap, tarsus, lid margin and eyelashes and without causing notable deformity at the donor site. The switch flap can successfully replace the Hughes flap technique and Cutler-Beard technique for repair of large eyelid defects.


Favorable effects of lacrimal plugs in patients with an anophthalmic socket. The use of punctal plugs in the treatment of dry eyes is well established. Anophthalmic patients have less tears in the anophthalmic socket in comparison to their normal side, due to an absent corneal reflex (Lee & Elsie, 1981a,b). Many of those patients complain of dry eye symptoms, even when they are treated with tear replacement therapy. The authors wished to examine whether they could improve their dry socket complaints with punctal plugs. To evaluate the clinical efficacy and tolerability of punctal plug (Smart Plugs) insertion in anophthalmic patients with symptoms of dry eye. Interventional case series. Fifteen anophthalmic patients with dry eye symptoms, a Schirmer test of less than 3 mm and an open lacrimal passage were examined before and after insertion of punctal plugs. The patients were asked for their subjective evaluation of the treatment and were examined to evaluate the change. Schirmer tests were compared. Bacterial cultures were taken at both visits. Schirmer results of less than 3 mm in the anophthalmic socket were obtained in 75% of patients with dry eyes symptoms; 87% of patients in whom punctal plugs were inserted reported an improvement in dry eye sensation. More than half of the patients demonstrated less discharge (p < or = 0.05). Schirmer tests improved from 1.4 mm to 1.9 mm (p < or = 0.05). Patients with a Schirmer outcome of 2 mm or more tended to have less pathogenic bacterial cultures (p = 0.11). Punctal plugs improve the symptoms and signs of dry socket. Punctal plugs seem to reduce the pathogenic bacterial growth in the anophthalmic socket.


Basosquamous carcinoma of the lacrimal sac: a case report. A 58-year-old woman, diagnosed with primary obstruction of the nasolacrimal system, underwent external dacryocystorhinostomy and silicone stent implantation. During surgery, an incisional biopsy was obtained from the posterior wall of the lacrimal sac. Pathological examination revealed basal cell carcinoma of the lacrimal sac. Two weeks later, the diseased sac and surrounding tissue were excised, using frozen sections to ensure adequate tumor-free margins. The lacrimal sac tumor was diagnosed as basal cell carcinoma with focal squamous differentiation. No tumor recurrence was detected in 1.5 years of follow-up. The authors recommend that lacrimal sac biopsy should be performed in patients with an enlarged lacrimal sac and nasolacrimal system obstruction.


Aggressive orbital optic nerve meningioma with benign microscopic features: a case report. Primary optic nerve meningiomas occur at lower ages than meningiomas arising from the coverings of the brain and spinal cord. Here we report the case of a 20-year-old female with an aggressive orbital meningioma referred to the Ophthalmology Department of the Farabi Hospital in Tehran. The patient had a history of orbital meningioma from 10 years ago and several surgical resections due to tumor recurrence during these 10 years. On admission, the patient had a large orbital mass and severe proptosis. MRI images revealed a large left orbital mass with optic nerve involvement and extension to the left maxillary sinus, pterygoid fossa and the dura in the floor of the anterior fossa. Fine-needle aspiration cytology of the mass confirmed tumor recurrence. The patient first received radiotherapy due to the inoperable mass, and the tumor was resected 1.5 month later. Microscopic study showed meningotheliomatous meningioma with extensive involvement of the optic nerve and invasion of the optic disc, sclera and choroid. The interesting aspect of this case was the aggressive behavior of the tumor with intraocular invasion, despite its benign histopathological features, which led to wide exenteration of the eye together with resection of the upper and lower lids.


Secondary orbital implant insertion in an anophthalmic patient after orbital reconstruction. The authors report the case of a 20-year-old man who underwent enucleation of his right eye with teratoma when he was an infant, without volume replacement by an implant. As a result, an underdeveloped shallow bony orbit finally occurred. Also, a contracted socket was present with shallow lower fornix, making ophthalmic prosthesis fitting almost impossible. The patient underwent surgical reconstruction of the orbit with expansion of the orbit vertically and horizontally. A secondary implant with an adequate volume was inserted to correct the orbital volume deficit. The previous expansion of the orbit allowed the insertion of an 18 mm-diameter hydroxyapatite implant wrapped in fascia lata. The lower fornix was expanded with a mucosal graft in order to overcome the socket contraction and the conjunctival shortage. The authors conclude that the final result of this approach is satisfactory. Almost 20 years after enucleation of an eye with teratoma, an attempt was made to correct most of the difficult problems dealing with a malformed shallow orbit and a contracted socket. The young patient is now able to wear a fine ophthalmic prosthesis and his appearance is greatly improved.


Near lethal art--transorbital brain injury. Penetrative transorbital injuries put intracranial structures in peril. We present one such case where a low velocity transorbital injury resulted in traumatic temporal lobe injury, but with full recovery. Clinicians should be vigilant of intracranial complications of transorbital injuries.


Visual recovery after evacuation of orbital emphysema. Orbital emphysema due to orbital trauma is a well-known occurrence. Visual loss due to orbital emphysema, however, is an uncommon phenomenon. A case of unilateral orbital emphysema following door-handle trauma with subsequent proptosis, painful ophthalmoplegia and compressive optic neuropathy resulting in compromised vision is presented in an 8-year-old male child. Conservative management, including intravenous corticosteroids, failed to resolve the patient's symptoms and compressive optic neuropathy. Surgical intervention to evacuate orbital emphysema resulted in prompt resolution of symptoms, including recovery of vision. A review of the medical literature revealed that only few isolated cases of orbital emphysema with compressive optic neuropathy have been reported previously, with no reports due to door-handle trauma.


Inferior oblique schwannoma: diagnosis and management. Orbital schwannoma accounts for less than 5% of orbital tumours and few cases arising in the superior orbit are reported in the literature. To present, to our knowledge, the first report of inferior oblique-associated orbital schwannoma. Interventional case report with clinical photographs, MRI imaging, intra-operative photographs and histology. A 68 year-old man presented with decreased right vision and double vision in downgaze. Examination revealed a right 3 mm ptosis, hypertropia and limitation of depression. Exploration and excision, via anterior orbitotomy, and histological examination confirmed a schwannoma located within the right inferior oblique muscle. Vision normalised post-operatively and there has been no clinical or radiological recurrence of the lesion at 2 years. This rare case highlights that schwannoma may occur in association with the inferior oblique complex and we suggest that schwannomas should now be considered in the differential diagnosis when patients present with a clinically-suspected or radiologically-proven orbital mass.


Contralateral orbital melanoma 28 years following enucleation for choroidal melanoma. A 79-year-old man underwent right enucleation for a choroidal melanoma. Twenty eight years later he presented with a nine month history of progressive left proptosis. Orbital imaging revealed a large left lateral orbital mass, extending back to the orbital apex, which was found on subtotal resection to represent an orbital melanoma. Skin survey was negative, and the prior right choroidal melanoma was the most likely metastatic source. He underwent radiotherapy of the residual tumor at the left orbital apex, as well as radiotherapy of small liver and lung nodules felt to likely represent metastatic melanoma. Five years later, he was still alive and well, with no further tumor demonstrable in the orbit, lung or liver. This case demonstrates the indolence and favorable prognosis of some orbital melanomas. We discuss some hypotheses that may explain such tumor behavior. While melanoma is often considered a highly malignant and lethal tumor, some melanomas are characterized by a more benign course. In addition, certain melanomas may respond to radiotherapy.


Orbital abscess and hemi-occlusion of the central retinal vein in a child. Orbital abscess is a serious infection which demands immediate and aggressive management. A case of orbital abscess associated with central retinal vein occlusion in a seven year old girl is reported. The diagnosis was established by computerised tomographic scanning and confirmed by bacteriological examination.


Endoscopic and trans-fornix removal of a giant orbital-ethmoidal osteoma. A 39-year old female was referred with a 2 year history of slowly progressive headache, exophthalmos, diplopia and restricted eye movements with exotropia of the right eye. Orthoptic examination revealed restricted elevation and mildly restricted adduction of the right eye. CT and MRI demonstrated a large (35 x 20 x 23 mm) calcified infraorbital lesion extending into the ethmoidal sinus. Because the visual field defects were progressive and the acuity OD dropped to 20/80 surgical intervention was necessary. The osteoma was successfully removed using an inferior and medial orbitotomy with swinging eyelid combined with an endoscopic approach. In a second procedure the orbital floor was reconstructed with a porous polyethylene (Medpor) implant. A final procedure consisted of a 3 mm recession of the left superior rectus muscle and infundibulotomy by the sinus surgeon to open the blocked maxillary sinus. After 6 months visual acuity OD had returned to 20/20. Orthoptic examination showed normal binocular function.


Basal cell carcinoma in lacrimal sac.

Basal cell carcinoma in lacrimal sac. A 53-year-old woman was admitted to the hospital one year after the onset of her complaints. She suffered from epiphora and swelling in the lacrimal sac region. Biopsy revealed islets of classical basal cell carcinoma with peripheral formation of palisades within a hyperemic stroma. During surgery, the lacrimal drainage system and neighboring bony structures were completely excised. No local recurrences were detected on orbital tomography performed 6 and 15 months postoperatively. As far as the authors know, this is the first case of basal cell carcinoma in the lacrimal sac reported in the literature.


A case report of bilateral autoenucleation and its prevention. To report a case and review both the ophthalmic and psychiatric literature to document the pattern of this self-mutilation and review prevention techniques. Case report and retrospective review. Surgical repair of the orbits in a patient who autoenucleated both eyes. To determine methods to prevent self-destructive behavior. Up to 75% of these acts are performed by psychiatric inpatients as a form of focal suicide. Methods to prevent self-inflicting behavior include differential reinforcement, boxing gloves, soft cotton gloves, a bubble helmet, facial screening, electrical stimulation, and tarsorraphy. Prevention of autoenucleation requires early identification of susceptible subjects and timely initiation of preventive measures.


Soft tissue plasmacytoma of the orbit as part of the spectrum of multiple myeloma.


Reconstruction following subtotal full-thickness upper eyelid resection with preservation of the lid margin. To describe a modification of a technique for upper eyelid reconstruction previously described by Patrinely et al. Radical excision of a large adenoid cystic carcinoma of the upper eyelid resulted in a subtotal full-thickness eyelid defect with preservation of 2 mm of eyelid margin. Reconstruction was performed with a free transconjunctival graft of maximum size from the contralateral upper eyelid, an overlying bipedicled skin-orbicularis oculi muscle flap and a free skin graft. With this one-step technique, a good cosmetic and functional result could be obtained. If the eyelid margin can be spared, reconstruction of even very large upper eyelid defects with a modification of the technique reported by Patrinely et al. may yield a good result.


An unusual case of complete ptosis and failure of elevation due to severe facial trauma. The authors describe the case of 49-year-old female teacher who had sustained severe facial lacerations following a minor fall on the kerb. The severe shearing force by which the flap was ripped off the forehead caused complete ptosis and complete failure of elevation of the left eye, which was presumed to be due to mechanical damage to the superior rectus and levator complex. The management by a multidisciplinary approach and clinical course of the patient are described with documentary photographs. This presentation is meant to highlight an unusual case of severe facial trauma resulting from a minor injury, and its successful management with gratifying results for both patient and the surgeon.


Is this really a capillary haemangioma?

Is this really a capillary haemangioma? Periocular tumours in newborn babies are not uncommon and their diagnosis and management can be challenging. Capillary haemangioma is the most common of them and superficial ones are easy to recognise. Deep-seated (orbital) lesions can mimic various other orbital mass lesions - dermoid cysts, cellulitis, lymphangioma and the more serious rhabdomyosarcoma and neuroblastoma. A careful elicitation of history, physical examination, and appropriate orbital imaging (ultrasound for superficial ones and magnetic resonance imaging/angiography for deep-seated lesions) helps in the diagnosis. This is a brief report of a very large vascular lesion involving the lower lid with very atypical clinical features. The approach to diagnosis and successful treatment and the histological features are discussed.


Mycobacterium abscessus infection in a case of recurrent orbital implant exposure. Exposure is one of the most frequent complications of porous orbital implants, while infection is rarely observed. Atypical mycobacteria are ubiquitous germs of mostly variable pathogenicity. A patient with recurrent orbital implant exposure is described, in whom a final diagnosis of Mycobacterium abscessus infection was made on culture of the orbital implant remnant at its removal. In orbital implant exposure, infection with unexpected organisms should be considered and in these cases only the complete removal of the implant may allow the socket to settle.


Linear nevus sebaceous syndrome associated with choroidal hemangioma. To report a rare case of linear nevus sebaceous syndrome in a little Chinese girl with a new ocular finding. Case report. The clinical manifestations, ophthalmic features and central nervous system abnormalities associated with this neurocutaneous syndrome are presented. A little girl, aged 1 year and 8 months, had several linear or oval nevi on her forehead and parietal scalp. Three round well-defined subcutaneous masses, approximately 1 cm in size, were present on the occipital, parietofrontal and right mastoid region, respectively. A round choroidal hemangioma, approximately 4-5 PD in diameter, was found in the superotemporal portion of the right fundus without retinal detachment. A round mass, 8 x 8 mm in size and tough in consistency, was located in the left upper eyelid, together with a 1/2 coloboma of the middle upper eyelid. Extensive choristomas of the superior bulbar conjunctiva and nearly the whole cornea were found in the left eye. CT-scans of both the brain and orbit disclosed left cerebral hypoplasia, dysplasia of sphenoid bone and temporal bone, and multiple calcifications of posterior sclera of both the right and the left eye. The mass on the left upper eyelid was removed and pathological examination confirmed the diagnosis of eyelid choristoma. Patients with linear nevus sebaceous syndrome may have choroidal hemangioma.


Pharmacokinetics of linezolid in bone tissue investigated by in vivo microdialysis. Pharmacokinetics of unbound anti-infectives in bone is difficult to characterize. The aim of this study was to assess the feasibility of the microdialysis technique to cancellous bone for single dose pharmacokinetic investigations of the anti-infective linezolid. Serial bone biopsies (left tibia) and microdialysate samples (right tibia: 2 catheters) as well as plasma and bone marrow samples were obtained from 10 pigs. The concentrations of linezolid reached bacteriostatic levels in plasma, bone marrow, bone biopsies and microdialysates. With the use of microdialysis we here present the first results for unbound linezolid bone penetration. Unbound linezolid concentrations in bone obtained by microdialysis were lower than might have been expected from previous bone biopsy studies. To achieve effective concentrations (24 h) for susceptible organisms the chosen dose of linezolid might not be sufficient.


Cognitive processing and motor skill learning in motor-handicapped teenagers: effects of learning method. This study aimed to assess the efficiency of a motor skill learning method intended to promote learning course personalization through an increase in cognitive processing deployment in motor-handicapped persons. Thirty-three secondary school students volunteered to participate in an archery motor skill learning session, 11 motor-handicapped (MH(1)) and 11 able-bodied (AB) teenagers following a standard learning method, and 11 motor-handicapped teenagers following a cognitive enriched learning method (MH(2)) based on the use of an individually written and illustrated document. The results showed that MH(1) displayed lower performances than AB, both in terms of the mental representations of the movements expected and performed and of efficiency of the movement. On the other hand, MH(2) performances were higher than MH(1) for all these parameters, and similar to those of AB at the end of the learning session. Personalization of the learning course allowed optimization of the learning potential in motor-handicapped teenagers to resolve the difficulties inherent to their handicap.


Plantar hypoesthesia alters time-to-boundary measures of postural control. Our purpose was to identify the effect of diminished plantar cutaneous sensation on time-to-boundary (TTB) measures of postural control during double and single limb quiet standing. Thirty-two healthy young adults underwent 10 min of ice immersion of the plantar aspect of the feet prior to balance testing. On a different day, the subjects did not receive this intervention prior to testing. A 2 x 2 vision (eyes open, eyes closed) by sensation (control, hypoesthesia) repeated measures design was used to analyze the TTB measures. In double limb stance, there were significant interactions between sensation and vision for the absolute TTB minimum and the mean of TTB minima in the anteroposterior (AP) direction. There was a significant increase in both measures after sensation was diminished with eyes closed compared to the control, but not with eyes open. In single limb stance, the TTB absolute minimum, the mean of TTB minima in the AP direction, and the standard deviation of TTB minima significantly increased with hypoesthesia regardless of vision. No significant differences were found in the medial-lateral (ML) direction for any of the TTB measures in double or single limb stance. Sensory information from the plantar cutaneous receptors appears to be most important in the maintenance of AP postural control.


Spatial localization of electrotactile stimuli on the fingertip in humans. This study was designed to determine the extent to which sensations elicited by discrete electrotactile stimulation can be spatially localized, with a qualitative comparison to mechanical stimulation, in a 2 x 2 electrode array on the fingertip. Electrotactile stimulation was delivered in two modes: (1) same current to all locations (constant) or (2) current adjusted to perceptual threshold of each location (varied). For each stimulus location, subjects were asked to identify the location of the stimulus. Mechanical stimulation of the same locations on the fingerpad was delivered through von Frey hairs (0.07, 0.2 and 0.4 g). The percentage of accurate responses was computed for all stimulation modes. We found that the accuracy of discrimination of stimulus location in both the constant (46%) and varied (40%) electrotactile stimulation modes was significantly higher than chance level (25%; p < 0.01). Furthermore, subjects were significantly more accurate in discriminating electrotactile stimuli in the constant than in the varied mode (p < 0.05). We also found that the accuracy of spatial discrimination was dependent on stimulation site for mechanical, but not electrotactile stimulation. Finally, we found a significant difference in accuracy over the duration of the experiment only for mechanical modes, which may indicate that electrotactile stimuli are less biased over time. These results suggest that, although low in accuracy, human subjects are able to extract spatial information from electrotactile stimuli. Further research is needed to optimize the amount of the information that can be delivered through electrotactile stimulation.


The genetics and ocular findings of Alagille syndrome. Alagille syndrome is an autosomal dominant disorder caused by mutations in the JAG1 gene. The JAG1 gene encodes a ligand for the Notch receptor and thus is part of a critical signaling pathway during development. The ophthalmologist can play an important role in the diagnosis of Alagille syndrome by identifying the characteristic ocular findings. These include a posterior embryotoxon, optic disc drusen, angulated retinal vessels, and a pigmentary retinopathy. Despite recent advances in the genetics of Alagille syndrome, the correlations between genotypes and phenotypes remain incompletely defined.


Cortical correlates of perception and suppression of electrically induced pain. Two neuroimaging studies using fMRI were conducted in order to assess the cortical processes involved in the perception and suppression of pain. In the first study, 15 healthy subjects were stimulated with variable intensities of electrical pulses during a discrimination task. In the second study, the same subjects had to try to suppress the feeling of pain during tonic stimulation. The discrimination task resulted in cortical activation of contralateral SI, corresponding in extent to the intensity of the stimulus. Activation of contralateral operculum/posterior insula (SII) and non-dominant dorsolateral prefrontal cortex (DLPFC) with non-painful stimuli changed to activations of non-dominant anterior insula upon painful stimulation. In the second study, all subjects succeeded in suppressing the feeling of pain during previously painful levels of stimulation. During this suppression task, activations changed from anterior to posterior insula; also there was a suppression of activity in the anterior cingulated cortex (ACC) and caudate nucleus. Subjects seem to be able to suppress to a certain degree the feeling of pain under constant (and previously painful) stimulation. The cortical correlate seems to be a shift of cerebral activation from anterior to posterior right insula and a suppression of activity in the ACC and caudate nucleus.


Pain additivity, diffuse noxious inhibitory controls, and attention: a functional measurement analysis. This study utilized the methodology of Functional Measurement theory to investigate the additivity of painful and non-painful thermally induced experiences at one body site with those produced by brief noxious and innocuous electrical stimuli at another. Forty healthy young subjects were tested, using a Peltier thermode to induce tonic pain and an electrocutaneous stimulator for presenting phasic pain, under conditions of either full attention or visual/cognitive distraction (counting numerous light signals) in order to evaluate whether the summed effects are attributable to refocused attention. Six levels of intensity were combined in a factorial design for both tonic and phasic pain. Subjects indicated the overall strength of their dual perception on a visual analog scale. Stimuli showed complex patterns of interaction. Two stimuli were generally rated as greater than one, but the summation was far from additive and greatly influenced by the intensity of the stronger stimulus, suggesting inhibitory action. In general, tonic heat pain strongly affected the perception of phasic electrocutaneous pain whereas the reverse was only partly true. Distraction had a very small effect, suggesting that the "pain inhibits pain" phenomenon attributable to diffuse noxious inhibitory controls (DNIC) is not due to attentional processes. Our data also relate to issues regarding spatial summation across dermatomes and to adaptation level effects in pain, in which a strong painful experience serves as an anchor or comparison point by which others are judged. The psychophysical findings provide a perceptual foundation for clinical phenomena in which patients face with comorbid pain disorders.


Activity cage as a method to analyze functional recovery after sciatic nerve injury in mice. The aim of this paper is to show the activity cage as a viable method for tracking functional nerve recovery. The activity cage measures spontaneous coordinate activity, meaning movement in either the horizontal or vertical plane, of experimental animals within a specified amount of time. This uses a minimum of researcher time conducting functional testing to determine functional recovery of the nerve. Using microsurgical forceps, a crush injury was inflicted unilaterally, on the left side, upon the 4-month-old C3H mice creating a very high degree of pressure for 6 s upon the exposed sciatic nerve. The locomotion function of the mice was evaluated using the activity cage preoperatively, 1, 7, 14, 21, and 28 days after the surgical procedure. We found that using the activity cage functional recovery occurred by 14 days after nerve crush injury. It was also shown that, coinciding with functional recovery, immunohistochemistry changes for GD1a and nNOS appeared at the level of L4, where the sciatic nerve joins the spinal column. GD1a and nNOS have both been linked to regenerative processes in mammalian nervous systems.


The interstitial system of the trigeminal spinal tract projects to the red nucleus in mice. We studied projections from the interstitial system of the spinal trigeminal tract (InSy-S5T) to the red nucleus of the mouse with retrograde tracers (fluorogold and latex microbeads impregnated with rhodamine and fluorescein). Injections in the magnocellular part of the red nucleus caused labeling of cells in the rostral, intermediate, and caudal paratrigeminal nucleus (Pa5), dorsal paramarginal nucleus (PaMD), insular trigemeo-lateral cuneate nucleus (I5CuL), and the trigeminal extension of the parvocellular reticular formation (5RPC). All projections were bilateral, but contralateral projections were stronger. The number of retrogradely labeled cells in the InSy-S5T in 3-, 6-, and 12-month-old mice was similar. Injections restricted to the parvocellular red nucleus did not label the nuclei of the InSy-S5T. This projection from the InSy-S5T to the red nucleus may mediate modulation of the facial muscles by pain and other sensory information.


Review of genetics in age related macular degeneration. Age-related macular degeneration (AMD) is a degenerative disease of the retina and the leading cause of blindness in industrialized countries. AMD is a complex disease caused by the combination of genetic predisposition and environmental factors. The prevalence of AMD increases with age. The adverse effect of smoking is well established. Genetic predisposition has been demonstrated by familial aggregation studies and twin studies. Using genome linkage scan and association studies, multiple potentially causative genes have been identified. The chromosomes most commonly implicated are 1q25-31 and 10q26. In particular, variants in the gene for the complement factor H (CFH) and the genes PLEKHA1/LOC387715/HTRA1, Factor B (BF) and complement component 2 (C2) have been implicated as major risk or protective factors for the development of AMD. There have been some advances in the treatment of this condition; however, a complete cure remains remote but hopeful. Understanding the causative environmental and genetic interactions will facilitate the development of future preventive methods and treatments.


The Use of Mitragynine speciosa ("Krathom"), an addictive plant, in Thailand. This study describes patterns and consequences of chewing leaves of krathom, Mitragynine speciosa, Kroth., traditionally used by rural people in Thailand as a mild narcotic. We surveyed 149 long-term regular users (daily for >or= 5 years), 168 occasional users (used only in social situations or medicinally, less than once a week), and 116 nonusers from three rural villages where krathom use was traditional in southern Thailand. Users focused on the perceived advantages of krathom in relation to increased work endurance, medication, and as a substitute for other hard substances rather than its harmful effects. Limitations regarding self-report and generalizability of the study were noted, and further longitudinal study among other population groups is required for educating people and users about possible harmful impacts of krathom use.


The Wnt signaling pathway in familial exudative vitreoretinopathy and Norrie disease. The Wnt signaling pathway is highly conserved among species and has an important role in many cell biological processes throughout the body. This signaling cascade is involved in regulating ocular growth and development, and recent findings indicate that this is particularly true in the retina. Mutations involving different aspects of the Wnt signaling pathway are being linked to several diseases of retinal development. The aim of this article is to first review the Wnt signaling pathway. We will then describe two conditions, familial exudative vitreoretinopathy (FEVR) and Norrie disease (ND), which have been shown to be caused in part by defects in the Wnt signaling cascade.


Understanding the relative influence of neighborhood, family, and youth on adolescent drug use. In the United States, a variety of programs have been developed to prevent substance use among youth. These programs often target youth directly, and may also have components that address the relational influence of families, schools, and communities. We discuss clustering of youth marijuana use within and between households and neighborhoods. As often discussed in the literature, we consider analyzing "components of variance" in a hierarchical sample design with two or more levels. With a continuous outcome variable, the estimated relative size of variance components at each level can be interpreted as its relative "importance." We estimate variance components when the outcome is dichotomous, and find that for the use of marijuana in the past year, the role of the individual (individual adolescent vs. role of household vs. role of neighborhood) is quite prominent (79% of variation). A similar result is observed for the continuous scale variable of individual positive attitudes toward drug use (83%). For continuous constructs related to either household (parental monitoring) or neighborhood (neighborhood disorganization) the majority of variation still occurs at the individual level (67% and 51%, respectively), although they reveal significant percent variation (about 30%) at the corresponding family or neighborhood levels as well. We discuss the use of variance component methodology and the relevance for prevention programs.


Integrating HIV prevention into substance user treatment: current practices and challenges. Despite well-organized prevention efforts, HIV continues to spread in the United States. Injection drug users (IDUs) and other substance users who engage in high-risk behaviors are at particularly high risk for contracting HIV. Substance abuse(dagger) counselors therefore are in a unique position to present HIV prevention messages to their clients. This article reports the results of a study that surveyed counselors in an urban setting (n = 116) to assess their knowledge of HIV, their current HIV prevention practices, and their attitudes about integrating HIV prevention more fully into their work. The article concludes with a discussion of the survey's limitations and its implications for training.


Genetics of hereditary vitreoretinal degenerations. The hereditary vitreoretinal disorders have variable vitreoretinal and other ocular and skeletal abnormalities. Some of these conditions represent a spectrum of clinical disease. This, along with the phenotypic variability, often leads to diagnostic difficulties. In this context, genetic testing is of valuable diagnostic value. Molecular genetic studies have helped distinguish conditions that were previously grouped together and proven others to represent spectrum of the same clinical entity. Accurate diagnosis is important in order to offer effective screening and genetic counseling and appropriate ophthalmological as well as systemic clinical surveillance.


Somatic configuration: a model for an integrated approach to the understanding of disease. A diachronic and synchronic interpretation of man and his relationship with the environment, with the contribution of the neurosciences and genetics, have made it possible to gain a better understanding of how organic, psychological, and environmental factors interact and contribute to the genesis of disease, whether mental or physical. The concepts of somatic configuration and interactional synchrony on which our model is based offer a unified approach to the relationship between man and his environment in which motor and relational capacities are aspects of a single process - one that aims to establish the best equilibrium with the environment in every moment depending on the individual's condition.


The application of machine learning techniques as an adjunct to clinical decision making in alcohol dependence treatment. With few exceptions, research in the addictive sciences has relied on linear statistics and methodologies. Addiction involves a complex array of nonlinear behaviors. This study applies two machine learning techniques, Bayesian and decision tree classifiers, in the assessment of outcome of an alcohol dependence treatment program. These nonlinear approaches are compared to a standard linear analysis. Seventy-three alcohol-dependent subjects undertaking a 12-week cognitive-behavioral therapy (CBT) program and 66 subjects undertaking an identical program but also prescribed the relapse prevention agent Acamprosate were employed in this study. Demographic, alcohol use, dependence severity, craving, health-related quality of life, and psychological measures at baseline were used to predict abstinence at 12 weeks. Decision trees had a 77% predictive accuracy across both data sets, Bayesian networks 73%, and discriminant analysis 42%. Combined with clinical experience, machine learning approaches offer promise in understanding the complex relationships that underlie treatment outcome for abstinence-based alcohol treatment programs.


Congenital corneal opacities: a review with a focus on genetics. Congenital corneal opacities present in approximately 3/100,000 newborns. Many different disorders may result in corneal opacifications of infancy, including Peters' anomaly (PA), congenital hereditary endothelial dystrophy (CHED), congenital hereditary stromal dystrophy (CHSD) and posterior polymorphous dystrophy (PPMD). Current studies have localized defects using genetic testing in PA, CHED, CHSD and PPMD. Identifying mutations for specific disorders may lead to better understanding of the underlying pathogeneses and may help with diagnosis and prognosis. This article will review the clinical presentations, treatments and genetics of Peters' anomaly, congenital hereditary endothelial dystrophy, congenital hereditary stromal dystrophy and posterior polymorphous dystrophy.


Parental support and control and early adolescent smoking: a longitudinal study. The aim of this study is to examine the role of parental support and control on young adolescent smoking initiation, increase, continuation, and cessation. Longitudinal data gathered every 6 months over a one-year period were collected in Utrecht, The Netherlands, for 1,012 adolescents in 2000. Logistic regressions demonstrated that low parental control predicted adolescent smoking initiation but neither support nor control predicted adolescent smoking increase or continuation. Parental smoking status was important in adolescent smoking continuation and cessation. Suggestions based on these findings are made for prevention programs. A limitation is that the study only utilized adolescent reports.


Molecular genetics of RB1--the retinoblastoma gene. Thirty-seven years ago Alfred Knudson proposed his "two-hit" theory of the molecular etiology of retinoblastoma, establishing an elegant conceptual paradigm for tumorigenesis in general. A great body of work has subsequently elucidated the structure and function of the RB1 gene and the biology of its protein product, pRB. Multiple categories of mutations have been characterized and correlated with phenotypic expression, including translocations, deletions, insertions, and point mutations. The purpose of this review is to provide a concise overview of the molecular genetics and genotype-phenotype correlations in retinoblastoma.


Methamphetamine users entering treatment: characteristics of the methamphetamine treatment project sample. The Center for Substance Abuse Treatment funded the Metamphetamine Treatment Project to evaluate and compare treatment approaches for methamphetamine users. As part of this study, drug use patterns, history of physical or sexual abuse, history of suicidality, and psychopathology were assessed in 1,016 methamphetamine-dependent outpatients entering treatment between 1999 and 2001 at eight sites across the western United States. The sample was predominately female and racially diverse. The mean age of the participants was 32.8 years. Most were methamphetamine smokers, but there were marked regional variations. Suicidality and physical or sexual abuse were common and measures of current psychopathology were high. These clinical issues were associated with more frequent use of methamphetamine and, more strongly, with concurrent use of other drugs. Therefore, the relationship between polydrug use and psychopathology in methamphetamine users warrants further investigation.


Playing [with] God: prayer is not a prescription.


Mandating vaccination: what counts as a "mandate" in public health and when should they be used? Recent arguments over whether certain public health interventions should be mandatory raise questions about what counts as a "mandate." A mandate is not the same as a mere recommendation or the standard of practice. At minimum, a mandate should require an active opt-out and there should be some penalty for refusing to abide by it. Over-loose use of the term "mandate" and the easing of opt-out provisions could eventually pose a risk to the gains that truly mandatory public health interventions, such as childhood vaccines, have provided over the last 50 years. Already, confusion about what counts as a mandate, and about what criteria should be used to determine when a public health intervention should be implemented as a mandate, has led to some inappropriate public policy decisions. For instance, by any reasonable criteria, the yearly influenza vaccine should be mandatory for health care workers. To enforce this mandate, those who refuse vaccination should be required to sign a waiver, and patients - especially those at high risk from flu - should be informed when they receive care from unvaccinated practitioners.


Universal and uniform protections of human subjects in research.


Clash of definitions: controversies about conscience in medicine. What role should the physician's conscience play in the practice of medicine? Much controversy has surrounded the question, yet little attention has been paid to the possibility that disputants are operating with contrasting definitions of the conscience. To illustrate this divergence, we contrast definitions stemming from Abrahamic religions and those stemming from secular moral tradition. Clear differences emerge regarding what the term conscience conveys, how the conscience should be informed, and what the consequences are for violating one's conscience. Importantly, these basic disagreements underlie current controversies regarding the role of the clinician's conscience in the practice of medicine. Consequently participants in ongoing debates would do well to specify their definitions of the conscience and the reasons for and implications of those definitions. This specification would allow participants to advance a more philosophically and theologically robust conversation about the means and ends of medicine.


The physician's conscience.

The physician's conscience.


Always let your conscience be your guide.


Defining conscience and acting conscientiously.


The proper place of values in the delivery of medicine.


The role of moral complicity in issues of conscience.


Negotiating the tension between two integrities: a richer perspective on conscience.


Conscience is the means by which we engage the moral dimension of medicine.


Conscience and conflict.

Conscience and conflict.


The moral significance of claims of conscience in healthcare.


Some reflections on conscience.

Some reflections on conscience.


The tao of conscience: conflict and resolution.


Defining the scope of implied consent in the emergency department. To determine the relative value that patients place on consent for procedures in the emergency department (ED) and to define a set of procedures that fall in the realm of implied consent. A questionnaire was administered to a convenience sample 134 of 174 patients who were seen in the ED of a Midwestern teaching hospital. The questionnaire asked how much time they believed was necessary to give consent for various procedures. Procedures ranged from simple (venipuncture) to complex (procedural sedation). Participants valued a simple blood draw at a low mean of 1.02 minutes of extra time and a lumbar puncture at a high mean of 7.78 minutes. Of all participants 52% and 48% noted a time-value of "0" time on blood draw and intravenous line starts, respectively, indicating that they desire no additional consent for these procedures. Defining a set of ED procedures covered under implied consent will be difficult because many patients value formal consent for even the simplest procedure.


Implied, presumed and waived consent: the relative moral wrongs of under- and over-informing.


The three faces of "yes": consent for emergency department procedures.


Is patients' time too valuable for informed consent?


Information disclosure and consent: patient preferences and provider responsibilities.


Consent: informed, simple, implied and presumed.


Defining the scope of implied consent in the emergency department: shortchanging patients' right to self determination.


Consent by survey: losing autonomy one percentage point at a time.


Mouse skin models for carcinogenic hazard identification: utilities and challenges. This report addresses 1) the predictability of mouse skin models for carcinogenic hazard identification, 2) the association between early changes in the skin and later tumorigenic responses, and 3) the relative sensitivity of three mouse models of skin tumorigenesis; i.e. the genetically-initiated Tg.AC and RasH2 lines and the SENCAR mouse model. All three mouse models responded similarly, with mild inflammation and epidermal hyperplasia, to several weeks of treatment with a topical agent. Based on our previous research experience, we hypothesized that inflammation, irritation, proliferation, and/or hyperplasia in the skin would precede and predict the appearance of tumors in these sensitive mouse skin models. Consistent with our hypothesis, the test agent caused a low but significant tumorigenic response in Tg.AC mice. We propose that inflammation, irritation, and hyperplasia are sensitive predictors of a later tumorigenic response in Tg.AC mice. Further studies are needed, however, to better determine the relative sensitivity of these 3 models to a wider variety of agents.


Effects of cigarette smoke in mice wound healing is strain dependent. It has been clinically and experimentally shown that cigarette smokers suffer from impaired wound healing, but the mechanisms that lead to the alterations are not well understood. The aim of this study was to investigate if the effects of cigarette smoke exposure on excisional cutaneous wound healing are different depending on the strain (Swiss, BALB/c and C57BL/6 mice) studied. Male mice were exposed to smoke of nine whole cigarettes per day, 3 times/day, daily, for 10 days. In the 11th day a full-thickness excisional wound was performed. Control group was sham-exposed and also had a full-thickness excisional wound. The cigarette smoke exposure protocol was performed until euthanasia. Animals were euthanatized 14 days after wounding. Wound contraction was evaluated 7 and 14 days after lesion. Sections were stained with hematoxylin-eosin, Sirius red or toluidine blue and immunostained for alpha-smooth muscle actin. Smoke exposed animals presented delay in wound contraction, in fibroblastic and inflammatory cells recruitment and in myofibroblastic differentiation; those alterations were strain dependent. Cigarette smoke exposure also affected mast cells recruitment and neoepidermis thickness. In conclusion, the present study demonstrated that the effects of cigarette smoke in mice cutaneous wound healing are related to mice strain studied.


Pulmonary lesions in female Harlan Sprague-Dawley rats following two-year oral treatment with dioxin-like compounds. Dioxin and dioxin-related compounds have been associated with high incidences of pulmonary dysfunctions and/or cancers in humans. To evaluate the relative potencies of effects of these compounds, the National Toxicology Program completed a series of two-year bioassays which were conducted using female Harlan Sprague-Dawley rats. The rats were treated orally for up to 2 years with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), 3,3',4,4',5-pentachlorobiphenyl (PCB126), 2,3,4,7,8-pentachlorodibenzofuran (PeCDF), and a ternary mixture of TCDD, PCB126 and PeCDF. In addition to treatment-related effects reported in other organs, a variety of pulmonary lesions were observed that were related to exposure. Pulmonary CYP1A1-associated 7-ethoxyresorufin-O-deethylase (EROD) activity was increased in all dosed groups. The most common non-neoplastic lesions, which occurred in all studies, were bronchiolar metaplasia and squamous metaplasia of the alveolar epithelium. Cystic keratinizing epithelioma was the most commonly observed neoplasm which occurred in all studies. A low incidence of squamous cell carcinoma was associated only with PCB126 treatment. Potential mechanisms leading to altered differentiation and/or proliferation of bronchiolar and alveolar epithelia may be through CYP1A1 induction or disruption of retinoid metabolism.


Diuron lacks promoting potential in a rat liver bioassay. The promoting activity of the herbicide Diuron was evaluated in a medium-term rat liver carcinogenesis bioassay that uses as endpoint immunohistochemically identified glutathione S-transferase positive (GST-P+) foci. Male Wistar rats were allocated to the following groups: G1 to G6 were initiated for liver carcinogenesis by a single dose of diethylnitrosamine (DEN, 200 mg/kg) while groups G7 and G8 received only 0.9% NaCl (DEN vehicle). From the 2nd week animals were fed a basal diet (G1 and G7) or a diet added with Diuron at 125, 500, 1250, 2500 and 2500 ppm (G2 to G5 and G8, respectively) or 200 ppm Hexaclorobenzene (HCB; G6). The animals were submitted to 70% partial hepatectomy at the 3rd week and sacrificed at the 8th week. The herbicide did not alter ALT or creatinine serum levels. No conspicuous GST-P+ foci development was registered in non-initiated rats fed Diuron at 2500 ppm. While DEN-initiated animals fed Diuron at 1250 or 2500 ppm developed mild centrilobular hypertrophy, DEN-initiated HCB-fed animals showed severe liver centrilobular hypertrophy and significant GST-P+ foci development. These findings indicate that the medium-term assay adopted in this study does not reveal any liver carcinogenesis initiating or promoting potential of Diuron in the rat.


A critical comparison of murine pathology and epidemiological data of TCDD, PCB126, and PeCDF. 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD, or dioxin) and dioxin-like compounds (DLCs) induce numerous toxicities, including developmental, endocrine, immunological, and multi-organ carcinogenic, in animals and/or humans. Multiple studies completed by the National Toxicology Program (NTP) focused on the effects caused in Harlan Sprague-Dawley rats by specific DLCs, among them the prototypical dioxin, TCDD. Because humans are exposed daily to a combination of DLCs, primarily via ingestion of food, the Toxic Equivalency Factor (TEF) was developed in order to evaluate health hazards caused by these mixtures. Herein we review the pathological effects reported in humans exposed to TCDD; 3,3',4,4',5-pentachlorobiphenyl (PCB 126); and 2,3,4,7,8,-pentachlorodibenzofuran (PeCDF) and compare them to similar changes seen in NTP murine studies performed with the same compounds. While there were differences in specific pathologies observed, clear consistency in the target organs affected (liver, oral cavity, cardiovascular system, immune system, thyroid, pancreas, and lung) could be seen in both human studies and rodent toxicity and carcinogenicity investigations.


Comparison of endothelial cell proliferation in normal liver and adipose tissue in B6C3F1 mice, F344 rats, and humans. Peroxisome proliferator-activated receptor gamma (PPARgamma) and dual PPARalpha and gamma agonists have been developed for use in the treatment of diabetes and hyperlipidemias. Vascular tumors were increased in mice treated with some PPAR agonists, but not in rats. Spontaneous hemangiosarcomas are common in several strains of mice, uncommon in rats, and rarely occur in humans. The objective of this study was to determine the endothelial cell proliferation rate in liver and adipose tissue of B6C3F1 mice, F344 rats, and humans to aid in investigations of the genesis and development of hemangiosarcoma formation, and to determine the relevance of the increased endothelial cell proliferation rate in drug-treated rodents in assessing the risk of these drugs in humans. We determined the endothelial cell labeling index (LI) in untreated mice, rats, and humans, in normal liver, brown fat (rats and mice only) and white fat by dual immunohistochemistry of CD31 and Ki-67. The LI, highest in mice and lowest in humans, was statistically significantly greater in the mouse compared to the human and rat. The increased rate of spontaneous or PPAR agonist-induced hemangiosarcoma formation in mice may be related to the higher background endothelial cell proliferation rate compared to rats and humans.


Histopathology of hemangiosarcomas in mice and hamsters and liposarcomas/fibrosarcomas in rats associated with PPAR agonists. Peroxisome proliferator-activated receptors (PPAR) are involved in the pathogenesis of insulin resistance, diabetes, and related complications. Consequently, the identification of PPAR subtypes and the potential for their activation provides promising therapeutic targets for the management of type 2 diabetes mellitus. Available data from rodent carcinogenicity studies, however, demonstrate that PPAR agonists can be tumorigenic in one or more species of rodents at multiple sites. In 2005, the Health and Environmental Sciences Institute (HESI) PPAR Agonist Project Committee was established by a group of pharmaceutical companies to advance research on and to understand the modes of action and human relevance of this emerging rodent tumor data for PPAR agonists. Since the most commonly observed tumor types reported in rodents are hemangiosarcomas, fibrosarcomas and liposarcomas, the PPAR Agonist Project Committee approved a Pathology Working Group (PWG) to develop consensus of morphologic criteria for tumor diagnoses and consistency of diagnoses across multiple studies for hemangiosarcomas in mice and hamsters and liposarcomas/fibrosarcomas in rats. Therefore, the focus of the PWG review was to establish consistent tumor diagnostic criteria, to assess evidence of potentially preneoplastic changes and to identify distinguishing morphologic differences which may exist between spontaneous changes present in control animals with similar changes from treated animals. Specific diagnostic criteria and nomenclature are recommended for the classification of proliferative vascular lesions which may be present in mice or hamsters and for proliferative mesenchymal changes in rats in studies that are conducted with PPAR agonists.


Preclinical evaluation of a dual-acting microbicidal prodrug WHI-07 in combination with vanadocene dithiocarbamate in the female reproductive tract of rabbit, pig, and cat. The mucosal safety of the combination antiretroviral spermicide,WHI-07 [5-bromo-6-methoxy-5,6-dihydro-3'-azidothymidine-5'-(p-bromophenyl)-methoxy alaninyl phosphate] and vanadocene dithiocarbamate (VDDTC), was evaluated in 3 different animal models. Twenty-seven NZW rabbits in four subgroups were exposed intravaginally to a gel-microemulsion (GM) with and without three dose levels of WHI-07 plus VDDTC (0.5+0.06%, 1.0+0.12% and 2.0+0.25%) or 4% nonoxynol-9 (N-9; Conceptrol) for 14 consecutive days. Ten nonestrus gilts (Duroc) in three subgroups received either a single or daily intravaginal application of GM with and without 2.0% WHI-07 plus 0.25% VDDTC or 2.0% benzalkonium chloride (BZK)-containing gel for 6 and 4 consecutive days, respectively. Five cats received a single intravaginal application of GM incorporating 2.0% WHI-07 plus 0.25% VDDTC. Genital tract histopathology was performed in the pig and rabbit at the end of dosing period but after 18 weeks post-dosing in the cat. Porcine cervicovaginal lavage (CVL) fluid was obtained for up to 72 hours after a single exposure and changes in the levels of inflammatory cytokines (IL-1beta, IL-8, IFN-gamma, and TNF-alpha) were quantitated by a multiplexed chemiluminescence-based immunoassay. Rabbit vaginal tissues were evaluated for localized cellular inflammation and in situ apoptosis by immunohistochemical staining for CD45, nuclear factor (NF)-kappa B, and terminal deoxynucleotidyl transferase-mediated FITC-deoxyuridine triphosphate nick-end labeling (TUNEL) using confocal laser scanning microscopy (CLSM), respectively. Vanadium content in selected organs and body fluids from rabbits and pigs was determined by atomic absorption spectroscopy. When compared with 4% N-9 (total irritation score 13-14 out of a possible 16), none of the rabbits given WHI-07 plus VDDTC intravaginally, developed histological alterations such as epithelial erosion, edema, leukocyte influx or vascular congestion characteristic of inflammation (total irritation score 4-6). CD45 and NF-kappa B immunoreactivity was limited to cells within the vascular lumen of both control and WHI-07 plus VDDTC-treated vaginal tissues. TUNEL assay revealed lack of increased apoptotic cells in vaginal mucosa exposed to increasing concentrations of WHI-07 plus VDDTC. Basal levels of proinflammatory cytokines (IL-1beta, IL-8, IFN-gamma and TNF-alpha) in porcine CVL were unaffected by intravaginal exposure to WHI-07 plus VDDTC when compared with BZK used as a positive control. Endpoint histology of the reproductive tract from cats and pigs after a single or repeated intravaginal exposure to WHI-07 plus VDDTC, respectively, revealed lack of irritation/inflammation in the epithelium, subepithelium/lamina propria, vessels/perivascular tissues, and underlying/surrounding muscles. Vanadium was not preferentially incorporated into rabbit or porcine tissues and body fluids at levels above 1 microg/g. Based on comparative histologic data and surrogate markers for inflammation, repeated intravaginal administration of WHI-07 plus VDDTC via a gel-microemulsion did not result in vaginal irritation, mucosal toxicity, or systemic absorption of vanadium. Therefore, the combined use of WHI-07 and VDDTC via gel-microemulsion appears safe for topical use as a prophylactic anti-HIV microbicide.


The demonstration of immunohistochemical biomarkers in methyl methacrylate-embedded plucked human hair follicles. Plucked human hair follicles have been proposed as a potential surrogate for tumour tissue for measuring the effect of drugs on pharmacodynamic biomarkers in drug intervention studies. We describe a new technique of embedding plucked hair follicles in the acrylic resin, methyl methacrylate, and the immunohistochemical demonstration of six potential biomarkers (Ki67, EGFR, phospho-p27, phospho-histone H3, phospho-MAPK and phospho-Rb) in de-plasticised sections. The advantages of this technique over those that have been used in support of clinical drug trials, such as skin and tumour biopsies, whole blood and whole hair samples is discussed.


Differential tumor biology effects of double-initiation in a mouse skin chemical carcinogenesis model comparing wild type versus protein kinase Cepsilon overexpression mice. Our previous studies showed that protein kinase Cepsilon (PKCepsilon) verexpression in mouse skin resulted in metastatic squamous cell carcinoma (SCC) elicited by single 7,12-dimethylbenz(a)anthracene (DMBA)-initiation and 12-O-tetradecanoylphorbol-13-acetate (TPA)-promotion in the absence of preceding papilloma formation as is typically observed in wild type mice. The present study demonstrates that double-DMBA initiation modulates tumor incidence, multiplicity, and latency period in both wild type and PKCepsilon overexpression transgenic (PKCepsilon-Tg) mice. After 17 weeks (wks) of tumor promotion, a reduction in papilloma multiplicity was observed in double- versus single-DMBA initiated wild type mice. Papilloma multiplicity was inversely correlated with cell death indices of interfollicular keratinocytes, indicating decreased papilloma formation was caused by increased cell death and suggesting the origin of papillomas is in interfollicular epidermis. Double-initiated PKCepsilon-Tg mice had accelerated carcinoma formation and cancer incidence in comparison to single-initiated PKCepsilon-Tg mice. Morphologic analysis of mouse skin following double initiation and tumor promotion showed a similar if not identical series of events to those previously observed following single initiation and tumor promotion: putative preneoplastic cells were observed arising from hyperplastic hair follicles (HFs) with subsequent cancer cell infiltration into the dermis. Single-initiated PKCepsilon-Tg mice exhibited increased mitosis in epidermal cells of HFs during tumor promotion.


Novel vascular lesions in mice given a non-peptide vitronectin receptor antagonist. Novel vascular lesions were observed in mice given an alpha vbeta 3, alpha vbeta 5 receptor antagonist (SB-273005) for up to 3 months. Vascular smooth muscle cell (VSMC) necrosis was observed in aorta and renal hilar arteries approximately 6 hours after dosing followed by loss of VSMC, adaptive medial thickening by VSMC hypertrophy and deposition of PAS-positive matrix and collagen. Renal hilar and arcuate arteries developed delayed and transient fibrinoid necrosis and inflammation. Vascular regeneration was not evident following drug-withdrawal after 3 days of dosing. Vascular lesions were associated with necrosis, regeneration and fibrosis of heart, kidney and spleen consistent with initial ischemic injury followed by tissue repair. VSMC toxicity was likely not related to integrin antagonism because lesions were not observed with related compounds and no vascular changes were observed in other preclinical species. In vitro studies failed to demonstrate a direct toxic effect of SB-273005 on VSMC or unique species sensitivity of murine VSMC. In conclusion, SB-273005 caused VSMC necrosis in aorta and renal arteries of mice. Lesions did not progress or recover, but there was medial hypertrophic adaptation even with continued dosing. This is considered direct species-specific VSMC toxicity of unknown mechanism and unrelated to vitronectin receptor antagonism.


Expression of serine/threonine protein-kinases and related factors in normal monkey and human retinas: the mechanistic understanding of a CDK2 inhibitor induced retinal toxicity. Protein-kinase inhibitors are among the most advanced compounds in development using the new drug discovery paradigm of developing small-molecule drugs against specific molecular targets in cancer. After treatment with a cyclin dependent kinase CDK2 inhibitor in monkey, histopathological analysis of the eye showed specific cellular damage in the photoreceptor layer. Since this CDK2 inhibitor showed activity also on other CDKs, in order to investigate the mechanism of toxicity of this compound, we isolated cones and rods from the retina of normal monkey and humans by Laser Capture Microdissection. Using Real-Time PCR we first measured the expression of cyclin dependent protein-kinases (CDK)1, 2, 4, 5, Glycogen synthase kinase 3beta (GSK3beta) and microtubule associated protein TAU. We additionally verified the presence of these proteins in monkey eye sections by immuno-histochemistry and immunofluorescence analysis and afterwards quantified GSK3beta, phospho-GSK3beta and TAU by Reverse Phase Protein Microarrays. With this work we demonstrate how complementary gene expression and protein-based technologies constitute a powerful tool for the understanding of the molecular mechanism of a CDK2 inhibitor induced toxicity. Moreover, this investigative approach is helpful to better understand and characterize the mechanism of species-specific toxicities and further support a rational, molecular mechanism-based safety assessment in humans.


Mesial temporal lobe epilepsy: pathogenesis, induced rodent models and lesions. Mesial temporal lobe epilepsy (MTLE), the most common epilepsy in adults, is generally intractable and is suspected to be the result of recurrent excitation or inhibition circuitry. Recurrent excitation and the development of seizures have been associated with aberrant mossy fiber sprouting in the hippocampus. Of the animal models developed to investigate the pathogenesis of MTLE, post-status epilepticus models have received the greatest acceptance because they are characterized by a latency period, the development of spontaneous motor seizures, and a spectrum of lesions like those of MTLE. Among post-status epilepticus models, induction of systemic kainic acid or pilocarpine-induced epilepsy is less labor-intensive than electrical-stimulation models and these models mirror the clinicopathologic features of MTLE more closely than do kindling, tetanus toxin, hyperthermia, post-traumatic, and perinatal hypoxia/ischemia models. Unfortunately, spontaneous motor seizures do not develop in kindling or adult hyperthermia models and are not a consistent finding in tetanus toxin-induced or perinatal hypoxia/ischemia models. This review presents the mechanistic hypotheses for seizure induction, means of model induction, and associated pathology, especially as compared to MTLE patients. Animal models are valuable tools not only to study the pathogenesis of MTLE, but also to evaluate potential antiepileptogenic drugs.


Temporal clinical chemistry and microscopic renal effects following acute uranyl acetate exposure. Military use of depleted uranium (DU) has renewed interest in the toxicology of this metal. In this study, the nephrotoxicity of single exposure DU was assessed with and without pre-exposure stress. Adult male Sprague-Dawley rats (n=288) were administered a single IM dose of 0, 0.1, 0.3 or 1.0 mg/kg DU. Corticosterone concentrations (ng/ml, mean+/-SD) were 763.65+/-130.94 and 189.80+/-90.81 for swim stressed and unstressed rats. Serum and kidney uranium concentration, hematocrit, chemistry, and renal histology were assessed on sacrifice days 1, 3, 7 and 30 post-DU-dosing. Dose related increases in serum and kidney uranium were noted. DU concentration peaked day 1 in the kidney and days 3-7, in the serum. Dose-related elevations of Cr and BUN concentrations were seen on days 3 and 7. A decline in serum albumin coincided with Cr and BUN suggesting protein losing nephropathy. Dose related acute tubular necrosis and proliferative glomulonephritis were seen. Tubular regeneration in low dose rats was almost complete by day 30. High dose rats had extensive tubular necrosis and delayed regeneration with focal residual chronic interstitial nephritis and cortical scarring. Glomular changes were reversed in all treatment groups by day 30. Stress exposure had no impact on any measured renal parameter.


An occurrence of multiple carcinomas in both kidneys of a 5-year-old female cynomolgus monkey (Macaca fascicularis). An occurrence of multiple carcinoma in both kidneys of a 5-year-old female cynomolgus monkey is described in the present paper. Macroscopically, the kidneys were enlarged with multiple solid and grayish-white masses and cysts mainly in the cortex and outer medulla. Light microscopically, carcinomas showed either tubulopapillary or tubulosolid growth patterns. Carcinoma cells were pleomorphic cuboidal to columnar cells. Cytoplasm was abundant and either granular and eosinophilic or clear, and nuclei were large and vesicular with prominent nucleoli. Electron microscopy revealed the existence of a brush border-like structure on the cell surface of carcinoma cells, suggesting that carcinoma cells arose from proximal tubular epithelial cells. Small foci of tubular epithelial cell hyperplasia and adenomas were also observed independently of carcinomas. There was no evidence of transition from adenoma to carcinoma, and no metastases were detected.


Melanin precursor 5,6-dihydroxyindol: protective effects and cytotoxicity on retinal cells in vitro and in vivo. 5,6-dihydroxyindole (DHI) is a melanin pigment precursor with antioxidant properties. In the light of a report about cytotoxicity of DHI, the aim of this study was to assess possible toxic effects of DHI on cells related to the eye, such as human ARPE-19 cells and mouse retinal explants. Moreover, DHI was tested on its effects on retinal function in vivo using electroretinography. We found cytotoxicity of DHI against ARPE-19 cells at 100 microM, but not at 10 microM. 10 microM DHI exhibited a slight, though not significant protective activity against UV-A damage in ARPE-19 cells. We found cytoprotection in cultured mouse retinas by 50 microM DHI or its diacetylated derivative 5,6-diacetoxyindole (DAI), respectively. In ERG measurements in vivo, amplitudes were decreased only slightly by 100 microM DHI compared to saline, whereas a better preservation of amplitudes was visible at 10 microM DHI, in particular with respect to cones. In histological sections, more cones were found at 10 microM DHI than at 100 microM DHI. As a conclusion, DHI shows a slight protective effect at 10 microM both in vitro and in vivo. At 100 microM, it shows a strong cytotoxicity in vitro, which is strongly reduced in vivo.


Excess mortality in two-year rodent carcinogenicity studies. This paper considers the impacts of various patterns of differential or excess mortality on the biological and statistical interpretation of 2-year rodent carcinogenicity studies. It provides suggestions on experimental design that are intended to maximize the value of such studies for carcinogenic risk assessment. Specifically, it recommends dose reduction, possibly to the level of dose cessation, when biologically feasible and considers the merits of termination of the entire study as alternatives to the commonly employed strategy of terminating particular dose groups. It then recommends statistical analysis modifications that are appropriate when these suggestions on experimental design are adopted. One of the recommended modifications is a new statistical test to determine whether a dose group exceeds the maximum tolerated dose (MTD) on the basis of mortality. While the authors provide recommendations for the most commonly occurring exigencies, they acknowledge the need for and strongly support the practice of active engagement of the appropriate regulatory agency, e.g., the FDA, prior to any action.


Variations in animal populations over time and differences in diagnostic thresholds used can impact tumor incidence data.


Six-month continuous intraputamenal infusion toxicity study of recombinant methionyl human glial cell line-derived neurotrophic factor (r-metHuGDNF in rhesus monkeys. Recombinant human glial cell line-derived neurotrophic factor (r-metHuGDNF) is a potent neuronal growth and survival factor that has been considered for clinical use in the treatment of Parkinson's disease (PD). Here we present results of a 6-month toxicology study in rhesus monkeys conducted to support clinical evaluation of chronic intraputamenal infusion of r-metHuGDNF for PD. Monkeys (6-9/sex/group) were treated with 0 (vehicle), 15, 30, or 100 microg/day r-metHuGDNF by continuous unilateral intraputamenal infusion (150 microl/day flow rate) for 6 months; a subset of animals (2-3/sex/group) underwent a subsequent 3-month treatment-free recovery period. Notable observations included reduced food consumption and body weight at 100 microg/day and meningeal thickening underlying the medulla oblongata and/or overlying various spinal cord segments at 30 and 100 microg/day. In addition, multifocal cerebellar Purkinje cell loss (with associated atrophy of the molecular layer and, in some cases, granule cell loss) was observed in 4 monkeys in the 100-microg/day group. This cerebellar finding has not been observed in previous nonclinical studies evaluating r-metHuGDNF. The small number of affected animals precludes definitive conclusions regarding the pathogenesis of the cerebellar lesion, but the data support an association with r-metHuGDNF treatment.


Quantitative analysis of aryl hydrocarbon receptor activation using fluorescence-based cell imaging--a high-throughput mechanism-based assay for drug discovery. Early identification of toxicity associated with new chemical entities is important for reducing compound attrition in late stage drug discovery. Activation of the aryl hydrocarbon receptor (AhR) by xenobiotics is a recognised mechanism of toxicity: the AhR mediates most, if not all, of the serious toxicities caused by the environmental contaminant 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). In addition to compounds such as TCDD, the AhR can be activated by compounds with drug-like properties; consequently there is a desire to eliminate AhR activity in candidate drug programs. Endogenous AhR translocates from the cytoplasm to the nucleus in response to prototypical AhR ligands. This trafficking was monitored in mouse Hepa-1 cells, human HepG2 cells and rat primary hepatocytes using an anti-AhR antibody. A confocal imaging plate reader, the InCell Analyzer 3000, was used to image fixed cells cultured in 96 well plates, and algorithms were used to analyse both population data and individual cell responses. The subsequent induction of the CYP1A1 gene, in the three cell models, was also assessed using quantitative real-time polymerase chain reaction and showed good correlation with the translocation assay. To conclude, we have established robust, automated high throughput assays for the identification of AhR activators in primary hepatocytes and cell lines.


Identification of cytochrome P450 enzymes responsible for N -dealkylation of a new oral erectogenic, mirodenafil. The purpose of this paper is to characterize the cytochrome P450 (CYP) enzymes involved in the metabolism of a new oral erectogenic, mirodenafil, to a major circulating active metabolite, N-dehydroxyethyl-mirodenafil, and to investigate the inhibitory potential of mirodenafil on seven CYP enzymes in human liver microsomes. CYP3A4 was identified as the major enzyme and CYP2C8 as a minor enzyme responsible for mirodenafil N-dealkylation based on correlation analysis, inhibition studies, and cDNA-expressed CYP enzyme activities. Plasma concentrations of mirodenafil and its N-dealkylated metabolite could therefore change with co-administration of known CYP3A4 inducers or inhibitors. Mirodenafil inhibited CYP3A4, CYP2C19 and CYP2D6 activities with IC50 values of 15.6, 38.2 and 77.0 microM, respectively, in human liver microsomes. However, it is very unlikely that mirodenafil will significantly alter the clearance of other compounds metabolized by CYPs 1A2, 2A6, 2C8, 2C9, 2C19, 2D6 and 3A4 because the maximum plasma concentration of mirodenafil is 0.55 microM after oral dosing of mirodenafil (100 mg) in male volunteers.


Nicotine metabolism and urinary elimination in mouse: in vitro and in vivo. This study aimed at elucidating the in vivo metabolism of nicotine both with and without inhibitors of nicotine metabolism. Second, the role of mouse CYP2A5 in nicotine oxidation in vitro was studied as such information is needed to assess whether the mouse is a suitable model for studying chemical inhibitors of the human CYP2A6. The oxidation of nicotine to cotinine was measured and the ability of various inhibitors to modify this reaction was determined. Nicotine and various inhibitors were co-administered to CD2F1 mice, and nicotine and urinary levels of nicotine and four metabolites were determined. In mouse liver microsomes anti-CYP2A5 antibody and known chemical inhibitors of the CYP2A5 enzyme blocked cotinine formation by 85-100%, depending on the pre-treatment of the mice. The amount of trans-3-hydroxycotine was five times higher than cotinine N-oxide, and ten times higher than nicotine N-1-oxide and cotinine. Methoxsalen, an irreversible inhibitor of CYP2A5, significantly reduced the metabolic elimination of nicotine in vivo, but the reversible inhibitors had no effect. It is concluded that the metabolism of nicotine in mouse is very similar to that in man and, therefore, that the mouse is a suitable model for testing novel chemical inhibitors of human CYP2A6.


Scanning electron micrographic features of a giant submandibular sialolith. To recognize recently appearing mineralization phenomena, one must study the external surface of the sialoliths, since it is not possible to study them in the central portions of sialoliths. The authors examined the external surface of a sialolith by scanning electron microscopy and analyzed its microstructures. The study revealed the presence of numerous microstructures of different shapes (nodular, laminar, reticular, microgranular, and multinodular) and variable size arranged in a haphazard fashion. The diverse microstructures encountered strongly suggest that different mechanisms of mineralization occur during growth and development of the sialoliths.


In vivo effects of Urtica urens (dwarf nettle) on the expression of CYP1A in control and 3-methylcholanthrene-exposed rats. The in vivo effects of the intraperitoneal administration of an Urtica urens L. (dwarf nettle) seed extract were examined on the hepatic, pulmonary, and renal cytochrome P450-dependent monooxygenase activities of rats co-administered with 3-methylcholanthrene (MC). Urtica extract was administered by intraperitoneal injection to male Wistar rats at 200 mgkg(-1)day(-1) for 4 days from which were also co-administered with intraperitoneal injection of 50mg of MC kg(-1) of body weight twice on days 1 and 3. MC treatment increased the 7-ethoxyresorufin O-deethylase (EROD) activity of the liver, lung, and kidney 54-, 21-, and 119-fold, respectively. Urtica treatment substantially reduced the 3MC induction of hepatic, lung, and renal EROD activity by 79, 42, and 50%, respectively. Similarly, compared with the control, MROD activities in liver and kidney were increased after MC administration, and these increases were significantly inhibited by Urtica. reverse transcriptase-polymerase chain reaction (RT-PCR) analysis clearly showed that the hepatic CYP1A1 and CYP1A2 mRNA levels substantially increased after treatment with MC, which was suppressed by Urtica supplementation. Western blotting studies also supported the alterations observed in the catalytic activities and mRNA levels. In conclusion, substantial reduction in CYP1A1 and CYP1A2 expression levels and related activities with Urtica are possibly associated with a potential chemoprotective ability of the Urtica due to the anticipated decrease in the activation of environmental chemical carcinogens through modulation of the CYP1A enzymes.


Disposition and metabolism of dipropyl disulphide in vivo in rat. The metabolism of dipropyl disulphide (DPDS), a sulphur compound from onion, was investigated in vivo in the rat. A single dose (200 mg kg(-1)) was administered by gastric intubation and the time courses of DPDS and its metabolites were followed over 48 h by gas chromatography coupled with mass spectrometry in the stomach, intestine, liver, and blood. DPDS was detected in the stomach where it was transformed into propyl mercaptan, whereas the liver contained only traces of DPDS and none at all in the other examined organs. The metabolites methylpropyl sulphide, methylpropyl sulphoxide (MPSO), and methylpropyl sulphone (MPSO2) were sequentially formed in the liver. The route of elimination from the liver seemed to be mainly via the blood. The bile also participated in the excretory process, but only for MPSO2. The pharmacokinetic parameters were determined for all of the above compounds. Whereas the bioavailability of DPDS was very low (0.008 h mM), the areas under the curve were higher for the S-oxidized metabolites MPSO and MPSO2, i.e. 9.64 and 24.15 h mM, respectively. The half-lives for DPDS and its metabolites varied between 2.0 and 8.25 h, except for MPSO2, which had a half-life of 29.6 h. MPSO2 was the most abundant and persistent of these metabolites.


Ultrastructural studies of jaw lymphomas and apoptosis. Research on ultrastructural cytopathological changes and apoptosis that occur in jaw lymphoma were done by using electron microscopy and ground sections. The author described this tumor in 1977-1978 as a highly malignant and lethal condition affecting children between 2 and 8 years (mean age 5 years). A duration of illness between 2 and 3 weeks is common and with a general condition of severe toxicity, anemia, and high body temperature. Clinical and pathological features of 24 children with jaw lymphoma seen in the Maxillofacial Unit, Surgical Specialized Hospital, Medical city, Baghdad, are described. Thirteen males and 11 females were included, with a death rate at 91.1%. The morphological characteristics were examined by ground sections. Lymphoblastic lymphoma features were observed and apoptotic changes were seen in some of the cells. Electron microscopy showed a high number of mitotic figures and lymphoblast transformation to plasma cells with high nucleo-cytoplasmic ratio. Some cells had double nuclei and some nuclei were more convoluted. Apoptotic changes were seen in some cells; chromatin clumps aggregated near the nuclear membrane. Cytoplasmic processes and mitochondria showing degeneration and virus-like particles were seen in both nuclei and cytoplasm. The presence of a high mitotic figure with active oncogenic virus growth and reduced apoptosis is a poor prognostic feature in jaw lymphoma.


Heredity mode of genetic polymorphism in aldehyde oxidase activity in Donryu strain rats. Donryu strain rats show genetic polymorphisms in the aldehyde oxidase gene, resulting in the phenotypic expression of ultrarapid metabolizers with homozygous nucleotide sequences (337G, 2604C), extensive metabolizers with heterozygous nucleotide sequences (377G/A, 2604C/T), and poor metabolizers with homozygous nucleotide sequences (377A, 2604T). In the mating experiments the ratio of the number of ultrarapid metabolizers, extensive metabolizers, and poor metabolizers rats in the F1 generation from the heterozygous F0 extensive metabolizers male and female rats was roughly 0.6 : 1.5 : 1, and the ratio converged to approximately 1 : 2 : 1 in the F2 generation from the heterozygous F1 extensive metabolizers male and female rats. On the contrary, all the F2 generation from homozygous F1 ultrarapid metabolizers male and female rats or from homozygous F1 poor metabolizers male and female rats had the ultrarapid metabolizers or the poor metabolizers genotypes and phenotypes. The genotypes completely agreed with the phenotypes in all individuals of F0, F1, and F2 generations. The results indicate that the genetic polymorphism of aldehyde oxidase in Donryu strain rats obeys Mendelian heredity. The reason for a low ratio of the ultrarapid metabolizers rats in the commercially available Donryu strain rats - not more than several per cent - compared with the ratio expected from the Mendelian rule is unknown.


Bartonella henselae infects human erythrocytes. Bartonella henselae, a facultative intracellular bacterium, has been known as the agent of cat scratch disease, bacillary angiomatosis, peliosis hepatis, endocarditis, and bacteremic syndrome in humans. Bartonella species can cause intraerythrocytic infections and have been isolated from the bloodstream of patients by several methods. It was demonstrated that B. bacilliformis and B. quintana infect human endothelial cells and human erythrocytes and B. henselae infects erythrocytes of cats. The aim of this study was to investigate through transmission electron microscopy whether B. henselae infects mature human erythrocytes. One red blood cell (RBC) unit received an experimentally standard strain of B. henselae. Blood aliquots were collected from the infected unit immediately after inoculation, at 30 min and 1, 5, 10, and 72 h for ultrastructural evaluation. B. henselae was seen adhering to human erythrocytes 10 h after inoculation and inside the erythrocyte after 72 h. This study demonstrates that B. henselae adheres to and invades mature human erythrocytes. The results favor the possibility that erythrocytes can serve as a primary target in Bartonella spp. infections. From this observation, further studies are warranted to prevent Bartonella spp. transfusional transmission.


Regulation of UDP-glucuronosyltransferase (UGT) 1A1 by progesterone and its impact on labetalol elimination. The authors recently reported the increased oral clearance of labetalol in pregnant women. To elucidate the mechanism of the elevated oral clearance, it was hypothesized that female hormones, at the high concentrations attainable during pregnancy, enhance hepatic metabolism of labetalol. Labetalol glucuronidation, which is the major elimination pathway of labetalol, was characterized by screening six recombinant human UGTs (UGT1A1, 1A4, 1A6, 1A9, 2B4, and 2B7) for their capacity to catalyse labetalol glucuronidation. The effect of female hormones (progesterone, oestradiol, oestriol, or oestrone) on the promoter activities of relevant UDP glucuronosyltransferases (UGT) was investigated using a luciferase reporter assay in HepG2 cells. The involvement of oestrogen receptor alpha (ERalpha) and pregnane X receptor (PXR) was examined by co-transfecting ERalpha- or PXR-constructs. UGT1A1 and UGT2B7 were identified as the major UGT enzymes producing labetalol glucuronides (trace amount of glucuronide conjugate was formed by UGT1A9). The activities of the UGT1A1 promoter containing PXR response elements were enhanced by progesterone, but not by oestrogens, indicating PXR-mediated induction of UGT1A1 promoter activity by progesterone. Results from semi-quantitative real-time polymerase chain reaction (PCR) assays are consistent with the above findings. This effect of progesterone on UGT1A1 promoter activities was concentration dependent. Promoter activities of UGT2B7 were not affected by either oestrogens or progesterone. The results suggest a potential role for progesterone in regulating labetalol elimination by modulating the expression of UGT1A1, leading to enhanced drug metabolism during pregnancy.


Detection of silver sulfide deposits in the skin of patients with argyria after long-term use of silver-containing drugs. Five patients with generalized slate-gray discoloration of the skin have been diagnosed histologically as argyria in the last 35 years in the Department of Dermatology and Venereology of Rostock and Halle. Light microscopically, there was visible black pigmentation in histiocytes, fibroblasts, and multinucleated giant cells of the dermis. In the transmission electron microscope (TEM), the authors observed electron-dense deposits inside lysosomes and residual bodies of phagocytes as well as outside the cells in the connective matrix. These deposits were identified by elemental analysis in TEM and electron energy loss spectroscopy (EELS) as well as scanning electron microscope (SEM) and energy dispersive x-ray analysis (EDX) containing silver and sulfur. Therefore, they seem to consist of silver sulfide. Argyria is of low medical relevance and is very rarely induced because of silver-containing drugs. Nevertheless, there are still a lot of silver products on the market, easily available over-the-counter. Therefore, argyria should not be forgotten or missed in the diagnostics of human dermis.