A new parallel plate dialyser. II. Description of design and in vitro performance. Using a high efficiency membrane support pattern, described in the previous paper, a prototype of a new parallel plate dialyser has been developed. The new dialyser is designed in such a way that the number of components is reduced to one item per blood layer and the membrane is folded as a continuum. This permits a semiautomatic assembly of the unit, which reduces production costs. Furthermore this technique facilitates aseptic handling of the item. The in vitro performance has been tested and it compares favorably with commercially available disposable parallel plate dialysers.


A new parallel plate dialyser. I. Development and testing of membrane support. The pattern of membrane support in the dialysate flow path of a dialyser is one of the most important parameters for high utlization of the membrane-area. 27 different injection moulded membrane support patterns were designed to approximate a pattern with the best overall properties. Only 15 of the patterns had acceptable properties in regard to 1) efficiency, 2) compliance, 3) flow resistance, 4) membrane rupture level, and 5) air retention at low flow values. A pattern with parallel interrupted ridges perpendicular to the direction of dialysate flow showed the best overall results although differences were marginal between the best patterns. The chosen support pattern was approximately 35% better in chloride clearance at low dialysate flow, and approximately 200% better at high flows than the conventional Kiil pattern.


A new parallel plate dialyser. III. Preliminary experience on clinical performance. The clinical model of a new parallel plate dialyser with a membrane area of 0.96 m2 with cuprophane 150 PM has been tested in more than 2000 dialyses with good clinical results. The simple design permits an aseptic, semiautomatic assembly and makes cheap industrial production possible. Clinical clearance values for urea, creatinine and uric acid are presented as well as data for ultrafiltration, residual blood volume and rupture frequency. The specific efficiency per square meter has been found to be high.


Radiological case of the month.

Radiological case of the month.


The possibilities and limitations of mixed-dentition treatment.


Relapse after activator treatment. A biometric, cephalometric, and electromyographic study of subjects with and without relapse of overjet.


Treatment of marked anteroposterior and transverse discrepancies in mandibular prognathism. A case report of a patient with a severe skeletal Class III malocclusion has been presented. The patient's marked anteroposterior discrepancy was complicated by the fact that his buccolingual occlusion was normal. The solution to this case thus involved a correction of the transverse discrepancy in addition to the anteroposterior discrepancy, which required orthodontic and surgical solutions. A discussion of mandibular prognathism has also been presented.


Biostereometric analysis of surgically corrected abnormal faces. Biostereometrics is an accurate anthropometric system for quantifying geometric changes of facial form and the relationship of features as they are influenced by growth and by surgery. Facial features distant from the site of surgical intervention are influenced in their geometric relationship to each other by changes in the soft-tissue drape brought about by manipulation of skeletal tissues. The most accurate coordinate system should be elsewhere than on the surface of the face, but if this is not possible it should be in an area farthest removed from the surgical site. This investigation demonstrates that a usable coordinate transformation system can be created by connecting points supernasale and subnasale for establishing the Y Z plane and the construction of the X Z plane at subnasale. Accurate comparative numerical measurements can be made by using soft-tissue landmarks.


Teaching orthodontics by the case method.


Orthopedics versus orthodontics in class II treatment: an implant study.


Lower incisor extraction in orthodontic treatment. The extraction of a single mandibular incisor can be employed as a compromise treatment of certain malocclusions, if the end result fulfills the requirements for a healthier dentition which is functionally and esthetically harmonized in relation to the surrounding structures. Indications, contraindications, and the procedure of treatment have been presented. Class I malocclusions with normal maxillary dentition and good buccal interdigitation in which there is severe lower anterior crowding are the best cases for this procedure, provided that the lower anterior arch length deficiency is greater than 4 to 5 mm. and the anterior tooth ratio is more than 83 mm. In conditions exhibiting a deep overbite pattern, reduction of the mandibular anterior unit should be avoided. Furthermore, I do not regard mandibular incisor extraction as a routine orthodontic procedure but, instead, consider it to be an almost last resort measure since it involves the most important stabilizing area of occlusion.


Face-bow testing on a dynamic extraoral force analyzer.


Malocclusion and treatment need in United States youths 12 to 17 years of age.


Immediate tonsillectomy for the treatment of peritonsillar abscess. Our experience with 119 cases of peritonsillar abscess supports the experience of others, that immediate tonsillectomy is a safe treatment which provides prompt, complete drainage of the abscess. There was one episode of immediate postoperative hemorrhage and one of delayed bleeding, but there were no anesthetic complications. If one believes that the abscess is an indication for tonsillectomy and plans to perform the procedure at some time, we recommend that it be performed as the drainage procedure. The total hospitalization time will as a rule be shortened and a second convalescent period avoided. Its major drawback is the inconvenience of inserting a relative emergency into the schedule.


Management of orthodontic treatment when first premolars are substituted for canines.


Developmental position of lower third molar in relation to gonial angle and lower second molar.


Adjustment of clinical crown height by gingivectomy following orthodontic space closure.


Experimentally determined force systems from vertically activated orthodontic loops.


The mandibular dental arch: Part I, lower incisor position. The position of the lower incisor with respect to hard tissue references has been evaluated. Two samples were used for this purpose: one containing 78 patients with posttreatment records having a postretention period of at least 4 years, and the other composed of 82 normal occlusions. The results indicated: 1) There was no significant difference in relapse of lower incisor crowding between cases where the lower incisor had been moved lingually, labially, or held in the same relative position during treatment. 2) The position of the maxilla should be considered when placing the lower incisor. The APo plane adequately serves as a guide to this purpose, whereas other reference lines such as mandibular plane or facial plane do not. 3) The positions of the incisors with respect to popular cephalometric reference lines such as APo, NB, or mandibular plane were not correlated with the relapse of mandibular crowding. Therefore, other clinical guides might be more successful for determining stability.


A cephalometric study of cranial, mandibular, and lower incisor morphology in the adult face.


The role of dental compensations in the orthodontic treatment of mandibular prognathism. Thirty-six patients with orthodontically treated mandibular prognathism were recalled for cephalometric and clinical evaluation. A comparison group of 32 non-Class III patients was similarly examined. Analysis of variables associated with the anterior dentition and documentationtion of labial gingival recession and tooth mobility led to the following conclusions concerning the role of dental compensations in the orthodontic treatment of mandibular prognathism. 1. Vertical and horizontal dental compensations were quantitated in the dentition of the study group (pretreatment to postretention). 2. Increased labial gingival recession and increased tooth mobility in functional jaw positions were present in anterior maxillary and mandibular teeth of the study group relative to the comparison group. 3. Proper diagnosis and the establishment of realistic treatment objectives by clinician and patient are necessary to avoid undesirable sequelae and/or undesirable facial esthetics in the treatment of mandibular prognathism.


Cephalometric evaluation of an oral stabilizing appliance with the modified Milwaukee brace.


Mandibular growth in surgically repaired cleft lip and cleft palate individuals.


The effects of reduced attrition on craniofacial and dentoalveolar development in the rat.


Primary retroperitoneal extraosseous osteogenic sarcoma: A case report and review of the literature. A case of retroperitoneal extra-osseous osteogenic sarcoma is reviewed, as well as the criteria necessary for the diagnosis. The general characteristics and the differential diagnosis of the tumor are also presented.


President's page.

President's page.


The diagnosis of TMJ disorders using laminographic radiography.


A self-treatment program of chemical preventative dentistry for high-risk patients.


The conservative treatment of temporomandibular joint pain dysfunction syndrome.


The surgical treatment of the temporomandibular joint.


Fewer students are enrolling to study.

Fewer students are enrolling to study.


Temporomandibular joint X-ray distortions.


A new year--a time to speak out.

A new year--a time to speak out.


Absence of protein-bound fluoride from human and blood plasma.


Development of peroxidase-mediated antibacterial activity in embryonic salivary  glands of the mouse.


A morphometric study of age changes in the histology of the ducts of human submandibular salivary glands.


Effect of fissure sealing on the microflora in occlusal fissures of human teeth.


Effects of x-irradiation and the resultant inanition on amylase content of the rat parotid gland.


Influence of ionic strength, calcium, sodium dodecyl sulphate and urea on the retention of chlorhexidine in the human mouth after mouth rinses.


Methylation analysis of extracellular glucans produced by Streptococcus mutans strain JC 2.


An interaction between hyperbaric pressure and taste in man.


Biochemical changes in rat parotid gland lysosomal enzyme activities after isoprenaline or starvation.


The teeth of the "sleek" mouse.

The teeth of the "sleek" mouse.


A radiographic and electromyographic study of snapping and biting in the oppossum.


Activation of the complement system by some gram-positive oral bacteria.


Effect of experimental lipoarthrosis on the articular fibrocartilage of the rabbit mandibular condyle.


Ultrastructure of fenestrated capillaries in human dental pulps.


The concentration of selected major and trace minerals in human dental plaque.


Taurodontism in human sex chromosome aneuploidy.


A histomorphological study of the shedding process of human deciduous teeth at various chronological stages.


Stereologic system and on/off-line computer program for analysing oral epithelia, based on a model of stratification.


The question of "resting" tonic activity of motor units in the masseter and temporal muscles in man.


Desire for attention.

Desire for attention. Seeking of attention appears to be intimately bound up with certain principles of motivation, especially the seeking of observable results of action and of optimum levels of stimulation, variety and challenge, and the relationship between results and the cost of achieving them--a high cost will tend to inhibit action but enhance the value subsequently placed upon what is achieved. These principles can be applied to personal relationships: thus friendship can be regarded as a situation involving facilitative feedback between persons, hostility as involving inhibitory feedback and lonliness as occurring when there is no feedback. Which of these situations occurs appears to depend upon the relationships between the costs and benefits of interaction between the persons concerned. The care of psychiatric or senile patients in the community appears likely to impose demands for attention which are unreasonably severe ("costly"). Any attempt to change community attitudes in the hope of securing greater acceptance of such demands appears to be unrealistic. Substantial benefits could probably be attained in many cases from training in skills, especially social skills, which would enable patients to cope more effectively with the world as it is.


A scale to measure the cause of life events. An increase in life event stress has been shown to occur prior to the onset of a number of psychiatric illnesses. This paper describes the construction of a scale to measure the cause of this increased life event experience. One hundred and five normal adults were asked to judge the extent to which any particular event might have occurred by pure chance, by one's own behaviour or by the behaviour of others. These three perceived causative factors are conceptually distinct and together comprehensive. Scalings on these three perceived causative factors for each of 67 life events were derived. The utility of such a scale is discussed.


Demythologizing the myth of mental illness.


Self descriptions of mothers of asthmatic children.


Psychodrama--as part of an integrated therapeutic programme.


Evaluation of group processes using visual analogue scales. Patients in a general hospital psychiatric unit completed Visual Analogue Mood Scales before and after group psychotherapy sessions, and at corresponding times on days without group meetings. Changes in the dispersion of scores between "before" and "after" measurements differed between days with group psychotherapy and days without. Cohesiveness attributable to the group process is suggested as likely explanation for this difference. Factors influencing measurements are investigated and discussed.


A comparative study of long-stay psychiatric patients discharged to boarding houses and satellite houses. A comparative psychosocial study of two groups of long-stay psychiatric patients discharged from Callan Park Hospital to boarding houses and satellite houses in the Callan Park Hospital region is reported. It was concluded that the social and vocational functioning of both groups was at a low level but that satellite house residents had more spare money and described a less institutionalized and a more homely environment in satellite houses.


The significance of suicide notes.

The significance of suicide notes. Studying the contents of suicide notes might help to improve the understanding of individual cases whilst offering an opportunity to search for possible preventive guidelines. In a study in an Australian capital city, suicides for one year (1972-73) were investigated including the medical and psychiatric data where possible, and psychosocial circumstances in each case. The total number of suicides in the year was 135. Twenty-seven individuals left suicide notes of which 25 were available for examination. The mood as reflected in the notes was categorised in terms of depression and hopelessness, neutral affect and hostility. The affect was related to age, sex, marital status and method of suicide. The results are presented with examples of each category and are discussed with respect to their contribution to (i) understanding the cause of death, (ii) understanding the intention of the suicide, (iii) assisting the relatives in coping with the suicide, (iv) drawing attention to those factors where earlier intervention may have averted suicide.


Cyproheptadine in bipolar affective illness with cushingoid features.


Biochemistry of Nitrogenase.

Biochemistry of Nitrogenase.


Limitations to field application of Rhizobium inoculants.


Public impact issues of genetic engineering in nitrogen fixation.


Environmental impact of genetic engineering in nitrogen fixation.


Genetic engineering of nitrogen fixation (NIF).


Genetic engineering for nitrogen fixation.


Agricultural productivity and biological nitrogen fixation--an international view.


Patients in need of dental care.

Patients in need of dental care.


Tooth exfoliation and osteonecrosis of the jaw following herpes zoster.


The diagnosis and management of sudden collapse in dental practice. Part 3. Collapse in the dental chair under local anaesthesia.


Automatic ventilation during bronchoscopy: experience with a Bird Mark 2 ventilator. One hundred and fifty patients were ventilated artificially during bronchoscopy using a Bird Mark 2 ventilator with either oxygen or a nitrous oxide in oxygen mixture as the driving gas. Satisfactory conditions for the examination were achieved. There was no significant deterioration in PaO2 or PaCO2.


Critical examination of data bearing on the type of alcoholic beverage consumed in relation to health and other effects.


A general practitioner study of the estimated prevalence of alcoholism in the Greater Manchester area.


Arrests for drunkenness and recidivism in juvenile delinquents.


Interrelationships of nutrition and voluntary alcohol consumption in experimental animals.


Alcoholic patients' perception of treatment milieu using modified versions of the ward atmosphere scale (WAS) and community oriented program environment scale (COPES).


Treatment of alcoholism in a community based alcohol rehabilitation programme.


Coercive treatment for alcoholic 'driving under the influence of liquor' offenders.


Self-reported mood and drinking patterns following hospital treatment for alcoholism.


Selected characteristics of nursing students who study alcoholism.


The determination of inferiority feelings and their contribution to psychiatric morbidity.


Manipulativeness among drug abusers: reliability and validity of the Mach IV Scale.


Pentazocine: a strong analgesic with low abuse potential.


A note on the misuse of pentazocine and dextropropoxyphene.


Detoxification from methadone maintenance in a family-oriented program.


Maintenance dosage as a critical factor in methadone maintenance treatment.


Heroin maintenance.

Heroin maintenance.


Assessment of drug sensitivity of human leukaemic myeloblasts. I. Labelling human myeloblasts with 125IUdR for survival studies in mice. The compound (125)IUdR can be incorporated in a stable form into the DNA of cells. The isotope is released if labelled cells or their progeny die. Consequently the rate of (125)I excretion from mice can be used to follow the fate of labelled cells in vivo. Using these principles we show:(1) Sufficient label can be incorporated in vitro into both fresh and cryopreserved human leukaemic myeloblasts, in non-toxic concentrations, to allow their survival in mice to be estimated by whole-body counting;(2) The release of isotope from labelled cells is sufficiently slow to offer reasonable expectation that this technique can be used for assessing the sensitivity of myeloblasts to cytotoxic agents in vivo (an application described in the second paper in this series, Sonis, Falcão and MacLennon, 1977);(3) The rate of (125)Iexcretion from mice injected with myeloblasts from different donors varies. This probably reflects different rates of spontaneous death of injected myeloblasts;(4) Active rejection of myeloblasts starts within 48 h of their injection into mice;(5) Indirect evidence that phagocytic cells may be active agents in myeloblast destruction in mice;(6) Various methods of immunologically depriving mice were assessed to see if they would result in a useful increase in survival of injected human myeloblasts. We conclude that there is little advantage and some limitations in using mice thus deprived;(7) One of the agents used for immunological deprivation-silica powder-markedly decreased the rate of (125)I loss from mice injected with labelled killed myeloblasts. This experience emphasizes the importance of including the killed-cell control in this assay.


Assessment of drug sensitivity of human leukaemic myeloblasts. II. The toxic effects of cytosine arabinoside on 125IUdR-labelled human leukaemic myeloblasts in mice. Leukaemia cells from the peripheral blood and bone marrow of patients with acute myeloblastic leukaemia were labelled in vitro with [125I]5-iodo-2'-deoxy-uridine (IUdR). The myeloblasts were then injected into groups of mice and the survival of these cells estimated by measuring isotope loss, using whole-body counting. The isotope excretion from mice treated with various doses of cytosine arabinoside (Ara-C) and those not treated with drugs were compared. This comparison showed that the sensitivity of myeloblasts to the drug varies from patient to patient, and in one case was different for myeloblasts from bone marrow and from blood from the same patient. We compare the clinical responses of myeloblasts to Ara-C in 6 patients, who had high peripheral blood myeloblast counts, with the sensitivities of their myeloblasts to Ara-C in mice. This comparison indicates that the assay might be a useful way of predicting the response of leukaemic cells in patients to cytotoxic agents.


Irradiation-induced erythroleukemia and myelogenous leukemia in the beagle dog: hematology and ultrastructure.


Why splint? Part two of a three part series.


Radiation control in the dental office: a need for awareness.


Protection of professional life in a litigation-prone society.


Requiem or reveille: psychiatry's choice.


Middle ear effusions: the thin and thick of it.


An investigation of occupational hand-arm vibration.


Statement on amygdalin (laetrile) by The New York Academy of Medicine.


Bronchiectasis in acute leukaemia.

Bronchiectasis in acute leukaemia. Five children in remission from acute lymphoblastic leukaemia developed bronchiectasis when on chemotherapy. Persistent collapse or consolidation on chest radiographs was helpful in suggesting the diagnosis. Necropsy established the diagnosis in one child who died of massive haemoptysis when in complete remission, and bronchography confirmed the diagnosis in three. In a further child the diagnosis was based on clinical and chest X-ray findings alone. The surviving children were treated with prophylactic rotating antibiotics. Routine chest radiographs are recommended in children with acute lymphoblastic leukaemia, as bronchiectasis may otherwise be underdiagnosed.


Hypercalcaemia as complication of accelerated chronic granulocytic leukaemia.


Chairside assistants overburdened? Hire a dental aide.


Ultrastrual cell cycle-specific nuclear and nucleolar changes of human leukemic lymphoblasts.


A phase 1 and 2 trial of rubidazone in patients with acute leukemia.


An intravenous technique for the behavior modification of mentally retarded patients.


Effect of sequence of combined radiation and cyclophosphamide regimens on murine osteosarcoma.


President's year-end report.

President's year-end report.


[Autoregulation of L-asparaginase-induced diabetes mellitus].


Another point of view.

Another point of view.


Schedule dependent effectiveness of CCNU and 5-fluorouracil in experimental chemotherapy.


Canadian guidelines for the teaching of pain and apprehension control in dentistry.


Rapidly progressing internal resorption.


CDA Council for Dental Materials and Devices. Status report: root canal sealing materials.


The effect of hemin on the expression of beta globin genes in friend cells.


Degradation and localization of IgG injected into Friend erythroleukemic cells by fusion with erythrocyte ghosts.


You've come a long way--maybe.

You've come a long way--maybe.


The legislative process: Massachusetts model.


How to succeed with the legislative process by really trying.


Registration--a tale of two states: RDAs--as Minnesota dentists see them.


Registration--a tale of two states: state licensure--the California experience.


RDA--what it means in Minnesota.

RDA--what it means in Minnesota.


A state's eye view of legislation: enroute to registration--in Maryland.


A state's eye view of legislation: cooperation is the key--in DC.


A state's eye view of legislation: stop and go--in Iowa.


National health insurance--so what else is new?


Are you violating the wage-hour rules?

Are you violating the wage-hour rules?


A state's eye view of legislation: and there was light--in Michigan.


A state's eye view of legislation: blood, sweat, and tears--in Oregon.


Measures of management: your productivity.


Sears Roebuck dentistry: like it or not.


Certifying the certifiers.

Certifying the certifiers.


Local anesthetics--just how local are their affects.


Proposed amendments to ADAA bylaws-1977.


My moment of truth in dentistry: a courage of great price.


Plan now to ease the pain of tax decay.

Plan now to ease the pain of tax decay.


Swap lives with a retired dentist?

Swap lives with a retired dentist?


The hidden faces of fear.

The hidden faces of fear.


Too little--too late.

Too little--too late.


Peer review.

Peer review.


From the editor's desk.

From the editor's desk.


The dental team. Hygienist hotline.

The dental team. Hygienist hotline.


A Russian Odyssey.

A Russian Odyssey.


Piggybackers beware.

Piggybackers beware.


From Henry W. Maier, mayor of Milwaukee.


Tomorrow.

Tomorrow.


Relative abrasiveness of dentifrices.

Relative abrasiveness of dentifrices.


A consumer looks at the role of the dental hygienist.


Status of dental auxiliaries: an issue of gender?


Panoramic versus periapical surveys. A comparison of findings on freshman dental students.


Kodak color films for dental photography.


Technic for placement of the ramus frame implant.


Job stress: 'recognition of problem is half the battle'.


A simple technic for treatment of dental trauma.


From structural 'disaster' to award-winning office.


Mercury: despite warnings, still a hazard in some offices.


The quest for health.

The quest for health.


Orofacial pain.

Orofacial pain.


Is your orthodontics stable?

Is your orthodontics stable?


Property insurances.

Property insurances.


Super 8 films, conclusions.

Super 8 films, conclusions.


Neuropathy in a patient with McArdle's syndrome and diabetes mellitus. A juvenile-type diabetic patient of five years standing presented with a mononeuritis and gave a history of painful muscle swelling induced by exertion. Failure of the blood lactate to rise during ischaemic exercise and a normal blood glucose rise following intravenous glucagon confirmed the clinical diagnosis of muscle glycogenosis. The association of diabetes and McArdle's Syndrome has not previously been documented. An ulnar nerve palsy, which persisted for many months, followed the ischaemic exercise test possibly due to compression by muscular swelling, but may have been exacerbated by the co-existing diabetes.


Unusual translocation (10;22) in chronic myelogenous leukemia.


Extramedullary blast crisis in chronic myeloid leukaemia simulating lymphoma.


Immunoblastic leukaemia.

Immunoblastic leukaemia.


Uptake of ascorbic acid by human leukocytes under normal & leukemic conditions.


A simple and reproducible method for separating Y-bearing spermatozoa from human semen. A simple and reproducible method for separating Y-bearing spermatozoa from human semen is reported.  Semen samples with 60-80 million count and 50% motility were obtained from healthy human donors.  Ficoll-400 and sodium metrizoate density gradient were used for separation.  Quinacrine hydrochloride was used for staining, and Olympus fluorescent microscopy was used for the detection of F body present in the spermatozoa bearing Y-chromosomes.  The data indicate that the percentage of Y-bearing spermatozoa in normal human semen is about 5-6% less than what is expected.  The observations agree with those of Barlow and Vosa that with the optical attenuation coefficient being sufficiently great, the chromosomes lying deep in the head may go undetected.  A mean value of 45.22 was obtained for Y-bearing spermatozoa and the sediment contained about 62.9 Y-bearing spermatozoa.  The results thus suggest that it is possible to separate Y-bearing spermatozoa from semen using Ficoll-socium metrizoate density gradient.


Acute infantile leukaemia.

Acute infantile leukaemia.


Endodontic therapy of traumatised teeth in children. One of the most difficult problems met with in endodontic therapy for children is the traumatized anterior tooth whose root is still incomplete. In cases where the pulp is vital, treatment by pulp capping or pulpotomy is directed to preserving the vitality of the radicular pulp to ensure completion of root formation. Calcium hydroxide remains the material of choice in both forms of treatment. Once root formation is complete, removal of the pulp residue and filling of the root canal may be performed as a preliminary to restoration by means of a post retained crown. Where the pulp is non vital, attempts to fill the funnel shaped apical part of the canal, whether from a coronal approach or by open operation for retrograde filling, have proved unsatisfactory. Many workers have shown however that a number of root filling materials and root dressings are capable of inducing either continued root growth or a closure of the apical region by a calcific scar. A detailed survey of 34 teeth treated by this method has been made and the important principles which appear to influence the success of the technique are enumerated.


The world wide distribution and significance of oral diseases. Data available to WHO shows that the profile of oral diseases differs dramatically between the technically advanced and the developing countries. In technically advanced countries the high tooth mortality due to caries is decreasing as a result of widespread dental care, though the incidence of the disease is little affected. Unless preventive measures can be applied the cost of maintaining curative services will outstrip the financial resources of even the most prosperous countries. In the developing countries where manpower is scarce the traditionally low prevalence of caries is tending to increase with progressive urbanization. Preventive measures are therefore vitally important and there is urgent need for field testing in these conditions. In both cases the development of preventive measures against periodontal disease is essential if teeth saved from loss by caries are not to be lost in later decades from the ravages of periodontal breakdown.


The clinical trial in multidisciplinary research. Dental research has developed along two separate paths. Epidemiological studies can only indicate a cause-disease relationship while laboratory experiments can only be applied to the human situation as a working hypothesis. The final solution can only be arrived at by setting up controlled studies in man, though there are limitations on the possibility of control of some variables in human studies. Experimental studies on the formation of pellicles and plaque are described as examples of the use of clinical trials to bridge the gap between basic research and epidemiological data. The ideal model for dental research would involve the identification of a clinical problem and its subdivision into small biological units which could be studied in the laboratory in order to develop working hypothesis. An in vivo model would then be devised to test the hypotheses and finally they would be applied in a well controlled trial.


Cultural factors in clinical pain assessment. Experimental evidence suggests that the threshold at which a given stimulus is perceived as painful is relatively constant both for an individual and between individuals. However, higher thresholds at which pain described as severe or at which particular behavioural response occurs are much more variable and appear to depend on cultural factors. Since one concern of a healing profession is to alleviate or minimize pain it would be helpful if some means of assessment of the intensity of pain experienced by other persons were available. Unfortunately no such measure exists. Distinction must be made between relief of pain which should be based on physiological principles and relief of distress in which socio-psychological factors are of much greater importance.


International collaboration and research in the organization of the education of dentists and the public. The dental curriculum in Western countries is still heavily biased towards technical competence in restorative procedures. Despite the evidence from many countries that curative dentistry has failed to make a significant impact on dental health, there is a reluctance to change to a preventive emphasis. Unfortunately dental education in developing countries is being modelled on the same pattern even though this is totally irrelevant to local needs and resources. The greatest need is for health  education designed to influence the lifestyle of people in a way which will reduce the prevalence of dental disease. Unfortunately the dentist's present training does not fit him to play an effective part in such a programme.


The epidemiology of oral tumours. A report prepared by a Working Group of the Commission on Classification and Statistics for Oral Conditions. The vital statistics collected by the national and international registries and organizations include information on oral cancer. As their work proceeds and the accumulated information increases and probably also becomes progressively more reliable because of increasing accuracy in clinical diagnosis and death certification, the purpose of epidemiological research, that is, the identification of etiological factors, will come nearer to fulfilment. On the other hand, very little is known about the epidemiology and demography odontogenic tumours. Although these tumours are relatively uncommon they are of considerable practical and theoretical importance to dentists, oral surgeons and pathologists. Since workers in the oral field are especially concerned with these lesions they are in a particularly favourable situation to collate data. Although a lengthy period would be required to amass significant numbers of cases, the effect would be well worth while.


Chemoimmunotherapy in acute myelocytic leukemia.


The clinical significance of serum transcobalamins in myeloid leukemia and other myeloproliferative disorders.


Juxtacortical chondrosarcoma.

Juxtacortical chondrosarcoma. The features are described of seven cases of "juxtacortical" chondrosarcoma, the term introduced by Jaffe for a rare but distinct entity and now accepted in the World Health Organisation classification as preferable to the term "periosteal" chondrosarcoma. In all cases the lesion involved the shaft of a long bone, most often the femur, and in two cases two different long bones were affected. Six of the seven patients were male and all were in the second decade. The characteristic appearance was that of a small tumour adjacent to the cortex with areas of spotty calcification often accompanied by radiating bone spicules perpendicular to the bone shaft and a typical Codman's triangle. Histologically all the tumours showed a cartilaginous lobular pattern, well limited on the surface and seldom infiltrating the cortex; areas of spotty calcification and enchondral ossification were often present but tumour osteoid and bone were conspicuously absent. Despite the ominous histological aspect, the prognosis proved to be relatively favourable compared with the usual central chondrosarcoma of a similar grade of malignancy.


Production of mouse globin in heterokaryons of mouse erythroleukaemia cells and human fibroblasts. In an effort to activate the globin genes of non-erythroid cells, tetraploid murine erythroleukaemia cells (Friend cells) were fused with diploid human amniotic fibroblasts. When the Friend cells were pretreated with dimethylsulphoxide, an average of 27% heterokaryons was observed. These cells stained with benzidine, an indication that they contained haemoglobin. The cells incorporated radioactive amino acids into proteins. Electrophoresis of [3H]leucine-labelled lysates on SDS urea polyacrylamide gels indicated that up to 7% of the newly synthesized protein co-electrophoresed with globin. CM cellulose chromatography demonstrated the presence of mouse but not human globin chains. Hybridization analyses of cytoplasmic RNA also revealed only mouse globin mRNA in the heterokaryons. Although heterokaryons form readily between mouse erythroleukaemia cells and human fibroblasts, and globin synthesis does occur, only the erythroid partner in the fusion system employed here directs globin production.


How to understand and deal with the growing economic crisis in orthodontics.


Second premolar extraction in Begg technique.


Monobloc treatment in the deciduous dentition--a case report.


Bio-progressive therapy.

Bio-progressive therapy.


Maxillary laterals as centrals.

Maxillary laterals as centrals.


Independent dimensions of depression: a factor analysis of three self-report depression measures. Covariance studies of objective depression measures have concentrated on total scores. This approach is relatively insensitive in specifying whether these instruments measure the same sub-aspects of depression. To investigate this question, a factor analysis was performed on the items of the Beck Depression Inventory and the Zung Self-Rating Depression Scale and lists A, B, C, and D of the Lubin Depression Adjective Check Lists. Ss were 91 college students and 29 correctional institution inmates. Four clearly interpretable multimeasure factors resulted from a Varimax rotation. The most salient factor was labeled "Depression: Affective Malaise." Earlier studies also have shown this to be a dominant and reliable dimension of depression. The other factors were: Suicidal Ambivalence," "Appetite-Weight Loss," and "Fatigability." Females showed greater Fatigability associated with depression. Factors specific to the Beck and Zung measures also were found, which suggests that the different emphases of these instruments, intensity/severity vs. frequency of symptoms, may contribute very specific depression indicators. This may indicate that both intensity and frequency of symptoms ought to be considered to obtain a "best" objective measure of depression.


Animal studies concerning the cariogenicity of dry breakfast cereals. Four studies were performed in rats and hamsters concerning the cariogenicity of cereals and the role of sucrose in that process. The findings indicate that sucrose content per se does not necessarily reflect the cariogenic potential. Presweetened cereals were more conducive to the formation of smooth surface caries in the hamster than were nonpresweetened cereals while no major differences between the cereals were observed in occlusal caries in rats.


Collaborative evaluation of a rat caries model in six laboratories. When highly controlled parallel rat caries studies were run simultaneously in six laboratories, a similar pattern of caries developed in every laboratory with a range in mean values such that the results of no investigator were significantly different from those of at least two others. These results indicate that the major factors influencing development of rat caries have been recognized and can be controlled within reasonable limits.


A chromatographic study of the relative affinities of rat bone and skin collagen alpha1 chains for hydroxyapatite. The affinity of a bone collagen alpha1 chain for hydroxyapatite has been compared to a similarly isolated skin component from the same animals. The chain from bone exhibits a higher affinity for the mineral. This enhanced affinity appears to be related to its primary structure, specifically its hydroxylysine moieties.


Evaluation of oral submucosal blood flow at dental injection sites by radioactive Xenon clearance in beagle dogs. Oral submucosal blood flow was measured at dental injection sites in anesthetized dogs and compared with subcutaneous blood flow. Blood flow was calculated from the measured half-time for clearance of radioactive xenon dissolved in saline. By this method, oral submucosal blood flow was much greater than subcutaneous blood flow and was comparable in magnitude to values reported for cerebral blood flow. Injection of a solution containing 1:100,000 epinephrine at the mandibular canal produce a delayed clearance of isotope which was three times as long as the clearance time for solutions without epinephrine.


Comparative cariogenicity of streptococcus mutans strains isolated from caries active and caries resistant adults.


Investigations into black extrinsic tooth stain. An investigation has been carried out into the nature of the black pigment in black extrinsic tooth stain. The results suggest that the black material is a ferric salt, probably ferric sulfide, formed by the reaction between hydrogen sulfide produced by bacterial action and iron in the saliva or gingival exudate.


Cariogenicity in rats of a diet containing lactalbumin or casein as the protein source.


Estimation of mesiodistal width of permanent canines and premolars in early mixed dentition. The accuracy for predicting mesiodistal widths of unerupted permanent canines and premolars from x-rays and their estimations based on the already erupted permanent teeth were tested in a group of Israeli children. The observed posteruptive widths related more closely to predicted values obtained from x-ray measurements than from tabulated estimations.


Identification of reducible crosslinks in rat gingival and palatal mucosal collagen.


Effect of strontium and fluoride administration on caries resistance of hamster molars.


In situ replication techniques: I. Preliminary screening and the negative replication technique. Fourteen commercially available elastomeric materials were investigated for their suitability as in vivo replication media. After a preliminary screening on an annotated specimen, three materials were chosen for further study. Of all materials evaluated, Xantopren Blue and Silene silicone impression materials provided the best results in vivo. This study demonstrates that a high resolution (ca 1 micron) negative replication technique may prove useful for the clinical evaluation of single-surface phenomena.


Loading rate and temperature as variables in amalgam bending. Three commercial dental amalgams of known dissimilar clinical properties were evaluated in pure blending at widely different loading rates and temperatures. Comparative data of fracture stress at 140 F rank these alloys according to their clinical fracture resistance; the phenomenon of creep may account for early marginal fracture prior to corrosion-induced fracture.


Hormonal responses of bone in a continuous flow cultural system. Calvaria from five-day-old mice incubated in a continuous flow system (10 calvaria per culture chamber with 1 ml volume; flow rate 1ml/hr.). In 24-hour cultures, calvaria showed less resorption than in stationary culture. Short-term responses to PTH and calcitonin were similar to those observed in vivo.


The effect of feeding frequency on rat caries.


The effects of chronic neutron radiation on the cell density of mouse oral epithelium.


The electron microscopy of bacteriophage-like particles in dental plaque. The morphology of bacteriophage-like particles contained in samples of dental plaque is described. The phage-like particles were observed within fusiform-shaped bacteria and in clumps between bacteria. The particles were hexagonal in cross section, approximately 1,100 nm in diameter and contained an electron-dense core. In areas of cell lysis tail forms were observed both free and in association with the particles. Occasional particles were attached to bacterial cell walls by means of shortened tailpieces.


A microbiological study of normal flora of macropod dental plaque. The percentage bacterial composition of dental plaques from 12 macropods was determined. The major group of organisms was gram-positive filamentous and pleomorphic rods whose median representation was 92.2%. These were mainly Actinomyces viscosus (median value 62.5%) and Bacterionema matruchotii (median value 23.2%). Streptococci were poorly represented (median value 4.2%) as were anaerobic gram-negative organisms. Aerobic gram-negative bacteria were identified as neisseriae and Moraxella sp. The macropod plaque flora was compared with that of human beings and rodents and the differences discussed in relation to dietary differences and the early externalization of the marsupial young.


Analysis of Asgar-Mahler reaction zone in Dispersalloy amalgam by electron diffraction. Selected area reflection electron diffraction has been used to determine the phases present in the reaction zones surrounding the Ag-Cu eutectic dispersant in Dispersalloy amalgam. The experiments were carried out on two kinds of specimens, (1) Dispersalloy amalgam and (2) Dispersalloy amalgam using 30, 50, 75, and 100% more mercury than found in commercially available capsules. The results show that the reaction zones in the specimens of the present investigation consist of Cu6Sn5 and Ag2Hg3. These diffraction data confirm the presence of the phases in the reaction zone which are suggested by the elemental analysis obtained by Mahler and his associates using an electron probe. Moreover, the strong intensity of the eta-Cu6Sn5 diffraction rings suggests a composition which is predominantly Cu6Sn5, again, in agreement with the electron probe data.


Streptococcus mutans serotypes in caries-resistant and caries-susceptible adults.


Dental caries induced by Streptococcus milleri.


Effects of daily rinses using sodium fluoride and organic fluorides on rat caries. The organic fluorides, alexidine dihydrofluoride and amine fluoride, provided greater protection against caries than sodium fluoride when used as a daily mouthrinse in rats. Alexidine dihydrochloride also provided significant caries restriction.


Induction of osteogenesis by free periosteum autografts.


The effect of added particles on the properties of Ag3 Sn-additive amalgams. Physical and chemical properties of amalgam alloys containing varying amounts of copper were evaluated. Evidence presented refutes the theory of physical strengthening due to the addition of silver-copper by its eutectic. Results suggest that reactive copper could be more advantageously added to the system by using fewer copper additive particles; these particles may need to have a greater copper content that those used in Dispersalloy.


Computerized prediction of optical density for diagnostic radiology. A computer program was formulated and verified experimentally to predict the optical density on an image receptor for any given set of radiographic variables including tube kilovoltage, milliamperage, and wave form; x-ray beam filtration; nature of filters and absorbers, and type of x-ray film.


Levan production by a strain of Rothia: activation of complement resulting in cytotoxicity for human gingival cells. An extracellular polysaccharide identified as a levan has been isolated from Rothia dentocariosa, strain 477 serotype 2. The levan produced by strain 477 has been found to activate the complement cascade in the absence of specific antibodies. This activation was found to be cytotoxic for human gingival cells in tissue culture.


Desmosomes observed in a gingival cell line.


In vitro enamel demineralization by Streptococcus mutans in the presence of salivary pellicles. Salivary pellicles developed on extracted teeth favorably affected the degree and nature of enamel demineralization when the teeth were incubated in vitro with either of two pure strains of cariogenic Streptococcus mutans. The mechanism responsible for this protection may relate to the permselective properties of these salivary pellicles.


Root surface caries in the molar teeth of rice rats. II. Quantitation of lesions induced by high sucrose diet. Weanling rice rats were fed either standard laboratory chow or Diet 2000. The animals were sacrificed at 4, 8, 12, and 15 weeks. There was an increasing amount of exposed root surface and root surface caries with age in the animals fed Diet 2000. There was exposed root surface but no caries in the animals fed laboratory chow.


Phagocytosis of latex beads by a human gingival epithelial-like cell line in tissue culture. Phatocytosis by a human gingival epithelial-like cell line in tissue culture was studied using latex beads as a marker. Electron microscopic and chemical analyses revealed that the cells ingested the beads in a quantitative and reproducible manner. This phagocytosis system is potentially useful for studying the effects of dental plaque on cell metabolism.


Effects of prostaglandin E1 on the periodontium of rats.


Polyacrylamide gel electrophoresis of human salivary histidine-rich-polypeptides. A method of polyacrylamide gel electrophoresis for examining histidine-rich-polypeptides in human saliva is described. Comparison is made to several commonly used electrophoretic techniques. The described method allows for the resolution of seven histidine-rich-polypeptide fractions and is convenient and quite reproducible.


Comments on "self-instruction in dentistry: a critique".


Oral biology--its raison d'être.

Oral biology--its raison d'être.


Too many dentists? If so, what then?

Too many dentists? If so, what then?


The effective clinical teacher.

The effective clinical teacher.


Comparing personality traits of male and female dental students: a study of two freshman classes. The marked increase in women enrolled in dental school warrants a reassessment of dental student personality profiles. The purpose of this study was threefold: (1) to compare personality profiles of two first-year dental classes, (2) to compare male and female dental student profiles to their respective norm populations, and (3) to compare male and female dental student personality traits with each other. The Comrey Personality Scales were administered to two first-year dental classes at the University of California at Los Angeles. Between sex and within sex comparisons were made over ten inventory scales. Results indicated that the collective personality profiles of male and female dental students were markedly similar to each other for both classes. These results do not reflect the differences encountered between the sexes in the norm population. It was also noted that the "average" male dental student differed from the male norms on Orderliness versus Lack of Compulsion, Social Conformity versus Rebelliousness, and Emotional Stability versus Neuroticism. In addition, "average" female dental student differed from the female norms on Masculinity versus Femininity.


Experiences with a training course in patient counseling. A program in patient counseling for dental students is described. The main objective of the present course is to make the students more aware of their own behavior and to train them in patient-centered behavior. In an effort to evaluate the effects of the training, a pilot evaluation study was completed. Students who had completed training two weeks before the study showed more nondirectiveness, empathy, warmth, and acceptance than students without such training. Seven months after the training a learning effect was evident as well.


Adaptation of the decision table in teaching oral diagnosis.


Communication skills training for dental students. It is important to teach future health professionals about human interaction, a process that will underlie their technical procedures throughout their careers. In the past there have been problems with student acceptance of such teaching. This paper reports a promising attempt to increase the perceived relevance and credibility of a course in communication skills for dental students. Two important features of this course are (1) the use of video-taped communication vignettes, derived from actual dental office situations, to increase the perceived relevance of the program for the dental student and (2) the use of selected clinical dental faculty members as group facilitators to increase the credibility of the program.


University students: a good source of dental school patients?


Isolation of Campylobacter fetus from recent cases of human vibriosis. Campylobacter fetus was isolated from five recent cases of human vibriosis, of which two were adults and three were children. One adult presented with pericarditis and the other with recurrent pyrexia. Campylobacter fetus subsp. intestinalis which resembled cattle strains serologically, was isolated under CO2 or anaerobic conditions from blood cultures of these patients. Two of the three children had kwashiorkor and the third was only 8 days old. Isolates identified as Campylobacter fetus subsp. jejuni were cultured from blood of these patients, two of whom had diarrhoea. Three patients succumbed, despite adequate antibiotic therapy. The epidemiology of the disease is discussed and it is suggested that infection may have been from the patients' own flora.


Immunity to attenuated influenza virus WRL 105 infection induced by heterologous, inactivated influenza A virus vaccines. Groups of student volunteers were immunized with one of five different inactivated influenza virus vaccines. The concentration of virus in the various vaccines differed by both the international unitage test and by the concentration of haemagglutinin, as measured by the single radial diffusion test; the results of the two methods of standardization showed no correlation. The serum HI response to immunization was variable; volunteers given A/England/72 showed a 16.6-fold increase in homologous serum antibody titre whilst volunteers given A/Hong Kong/68 vaccine showed a 4.2-fold increase. The variable response of volunteers to immunization could not be explained by the varied concentration of virus in the vaccines, as measured by either test, the titres of serum HI antibody present before immunization, or a combination of these two factors.The ability to infect volunteers with WRL 105 virus 4 weeks after immunization with heterologous, inactivated virus vaccine was directly related to the degree of cross-reactivity between the haemagglutinins of this vaccine virus and WRL 105 virus. Thus, the greatest number of infections by the challenge virus were seen in volunteers given A/Hong Kong/68 vaccine, less were observed in volunteers given A/England/72 vaccine, and least were found in groups given A/Port Chalmers/73 or A/Scotland/74 vaccine. However, compared with the incidence of infection in volunteers given B/Hong Kong/73 vaccine, all the heterologous influenza A vaccine gave some immunity to challenge infection.


Myxomatosis: the transmission of a highly virulent strain of myxoma virus by the European rabbit flea Sphilopsyllus cuniculi (Dale) in the Mallee region of Victoria. The European rabbit flea Spilopsyllus cuniculi (Daley was introduced into Australia to act as a vector of myxoma virus. It was first released in the semi-arid Mallee region of Victoria in 1970 where epizootics cuased by field strains of myxoma virus occur each summer. Introductions of the readily identified Lausanne strain were made annually following the release of the flea. The introductions were successful and the strain persisted for up to 16 weeks despite competition from field strains. The Lausanne strain is more readily spread by fleas than the Glenfield strain which has been widely used in rabbit control. The ability of the Lausanne strain to persist and its effective transmission compared with the Glenfield strain may be due in part to the more florid symptoms of the disease.


Innate resistance to myxomatosis in wild rabbits in England. Wild rabbits (Oryctolagus cuniculus) from one study area in England have been used over a period of 11 years to investigate the possible appearance of innate resistance to myxomatosis. Rabbits of 4-6 weeks old were captured alive, retained in the laboratory until at least 4 months old, and then infected with a type of myxoma virus which kills 90-95% of laboratory rabbits. Observations were made of symptoms, mortality rate and survival times.In the first 4 years of the study (1966-9), mortality rates were not significantly different from those of laboratory rabbits, although survival times of wild rabbits were appreciably longer. In 1970, the mortality rate amongst wild rabbits was 59%, in 1974 it was 17%, and in 1976 it was 20%, thus showing that a considerable degree of inherited resistance to myxomatosis has developed.The types of myxoma virus most commonly isolated from wild rabbits in Great Britain in recent years have been those which cause 70-95% mortality in laboratory rabbits. Therefore, if the degree of innate resistance demonstrated is widespread in Great Britain, there are serious implications regarding the size of the rabbit population, because myxomatosis has been an important factor in holding rabbit numbers at a relatively low level.


The potential for contamination of intravenous infusions by airborne skin scales. Skin scales may be attracted onto the surface of administration set connector needles before insertion into infusion containers. Viable microorganisms associated with skin scales may therefore gain access to the infusion by this route. A technique is described for creating an environment of airborne skin scales. This environment is used to examine the attraction of skin scales onto the surface of administration set connector needles and three other materials. After exposure, skin scales are found adhering to the surface of each material examined. The attraction of skin scales onto administration set connector needles is dependent on the time of exposure to the environment. Results suggest that intravenous infusions can be contaminated by this route when the infusion and administration set is assembled.


A standard technique for the isolation of Salmonella from animal feeds. Two trials were carried out by 9 and 47 laboratories to evaluate the reproducibility and sensitivity of a standard technique for the isolation of salmonellas from animal feeding stuffs. The trials involved the examinations of test samples containing known numbers of salmonellas by a buffered peptone water pre-enrichment technique. Statistical analysis of the results of the trials showed that the method was capable of detecting salmonellas in most probable numbers as low as 2.3 per 100 g and that no significant differences in performance were observed between laboratories. The standard technique described is recommended for the examination of animal feed and conforms to international recommendations.


Conference on inflammation. Is inflammation a defense mechanism? A debate.


Conference on inflammation. Discussion--part 2.


An in vivo evaluation of the penetration of an irrigating solution in root canals.


Incidence of bacteremias related to endodontic procedures. II. Surgical endodontics.


Appraisal of the double Master's two-step test: correlation with coronary arteriographic findings.


Surgical treatment for patients with renovascular hypertension.


Hemiblock in acute myocardial infarction.


Malassimilation of carbohydrate.

Malassimilation of carbohydrate.


Mycotoxins in soy sauce and fermented soybean paste of Taiwan.


Studies on the metabolism of mimosine.

Studies on the metabolism of mimosine.


Cardiac enzyme study in the diagnosis of acute myocardial infarction-simultaneous determinations of creatine phosphokinase isoenzymes and lactate dehydrogenase isoenzymes.


Lipid abnormalities in Chinese with angiographically proved coronary artery disease.


Blood coagulation and renal vein thrombosis in nephrotic syndrome.


How to check for proper installation of anesthetic equipment.


Burn injuries in a patient with syringomyelia. Case report.


Computer-based analysis of 227 white males and females to establish range of malar-maxillary cephalometric relationships. A computer-based analysis was undertaken on 227 white males and females to establish the relationship of the sella-nasion orbitale angle to that of the sella-nasion A point. The ratio of sella-orbitale to sella-nasion was also studied and it was discovered that these results were significantly related to the sella-nasion A-point angle. There was little sexual dimorphism. These results provide objective guidelines to the surgical treatment of people suffering from hypoplastic development of the middle part of the face.


Changes of heart rate during administration of local anesthetics in the oral region. In an attempt to clarify the mechanism of shock in dental patients, the effects on the heart rate of the injection of an anesthetic agent into the oral mucosa were studied. The heart rates of the subjects decreased by an average of 12.6% during infiltration anesthesia, which was greater than that induced by the mandibular block or breathholding. The response was completely blocked by general anesthesia and partially blocked by inhalation of nitrous oxide and oxygen or previous administration of atropine, indicating the possible participation of trigeminal-vagal reflex in producing these changes of heart rate.


Oral lichen planus and diabetes mellitus: a possible association.


Folic acid deficiency preceding non-tropical sprue.


Comparison of ilium to rib for bone grafting in defects of canine mandibular alveolar fidge. The behavior of iliac and rib grafts in surgically created defects in canine alveolar ridges was investigated. Despite the greater amount of potentially osteogenic tissue in the iliac graft, no significant qualitative differences were noted in the bony remodeling for a year. However, the rib grafts did form a mature superior cortical border significantly more rapidly, leading to speculation on the advantages of rib over iliac graft in alveolar ridge grafting.


Why pharmacology in oral medicine?

Why pharmacology in oral medicine?


Submandibular gland enlargement.

Submandibular gland enlargement.


Management of hemorrhagic shock due to facial lacerations in the third trimester of pregnancy.


Osteoporosis.

Osteoporosis.


Osteoporotic, hematopoietic mandibular marrow defect: an osseous manifestation of sickle cell anemia.


Renal cell carcinoma metastatic to the mandible.


Squamous odontogenic tumor: report of three cases.


Fabrication of enamel adhesive retainer for segmental alveolar surgery.


Mandibular ridge augmentation by a modified visor osteotomy: preliminary report.


A report on lesions diagnosed in the school of dentistry biopsy service, University of Oregon Health Sciences Center-1976-77.


Evaluation of fluoride-impregnated prophylaxis cups.


Recurrent herpes simplex virus infection. Part III: immunological aspects.


Temporomandibular joint dysfunction in children.


Strategies in...Quality, excellence, and the pursuit of dentistry.


Comments... The emerging role of the dentist as a health facilitator.


Case review... Emergency fixation of traumatized anterior teeth using autopolymerizing acrylic resin.


Oral premedication for the problem child: placebo and chloral hydrate.


Caries susceptibility testing: an evaluation of three methods.


A review of the function of the dental bur.


Teething as a problem of infancy.

Teething as a problem of infancy.


The use of hypnosis on the anxious pediatric dental patient.


Oral manifestations of impetigo: report of two cases.


Idiopathic short root anomaly.

Idiopathic short root anomaly.


Reflex muscle atrophy induced by chronic peripheral nociceptive stimulation.


The spinocervical tract as a possible pathway for muscular nociception. In decerebrate and chloralose-anaesthetized spinal cats, micro-electrode recordings were made from axons of the spinocervical tract (SCT) during intra-arterial injection of bradykinin, 5-hydroxytryptamine and potassium into the gastrocnemius-soleus (GS) muscle. The results suggest that muscular group IV and group III afferent units which respond to the above painful stimulation project into the SCT. The portion of SCT units that could be activated by injections of these algesic substances into the GS-muscle was different in spinal and decerebrate preparations, showing that the SCT neurones are subject to a descending influence. It is concluded that the spinocervical tract, in addition to its function as a cutaneous sensory pathway, may serve as a pathway for muscular nociception in the cat.


Fate of 14C-glucan in normal and acute myelogenous leukemic rats.


Implantology is a triumph.

Implantology is a triumph.


The subperiosteal implant denture program at the University of Southern California. Part III. Design of implant denture substructure.


An in vitro support analysis of solid, multi-vented and grooved endosseous blade implants.


Implanted lower full denture with Scialom pins and its electromyographic control.


The use of three dimensional implants to salvage existing permanent prostheses.


Delivery of quality.

Delivery of quality.


Dental practice management and taxes.

Dental practice management and taxes.


Acute myelogenous leukemia as a late complication of the multimodality therapy for Hodgkin's disease. Progressive thrombocytopenia developed in a patient following the completion of total lymphoid irradiation and combination chemotherapy for Hodgkin's disease. Thorough evaluation eventually yielded a diagnosis of acute myelogenous leukemia (AML). Previous workers have suggested that the development of thrombocytopenia with a hypoplastic marrow following total lymphoid irradiation indicated recurrent Hodgkin's disease. When the combination cytopenias and hypoplastic marrow is recognized these workers have recommended early combination chemotherapy. Recent data suggest a 1300-fold increase in the risk of AML following multimodality therapy for Hodgkin's disease. We feel that a careful search for AML should be conducted in patients with deteriorating  hematologic parameters following therapy for Hodgkin's disease and that this search should include sampling bone marrow outside irradiated areas.


Neoplasms of the small intestine.

Neoplasms of the small intestine.


Acetaminophen overdosage.

Acetaminophen overdosage.


Continuing medical education - past, present and potentials for the future.


Carbon dioxide laser therapy in otolaryngology.


Where are we today in professional liability? Where should we be going?


Specificity of serotoninergic involvement in the decrease of food intake induced by quipazine in the rat.


Chemotherapy with cyclophosphamide, vincristine, cytosine arabinoside, and prednisone (COAP) in childhood acute lymphoblastic leukemia (ALL). Three groups of children with acute lymphoblastic leukemia (ALL) were treated with intermittent cyclophosphamide, vincristine, cytosine arabinoside, and prednisone (COAP). Group A (no prior relapse) and Group B (prior single-agent relapse) received COAP after 12 months on another chemotherapy regimen. Children in Group C (prior relapse on multiagent regimens) received COAP following A-COAP (asparaginase plus COAP) reinduction. Median disease-free survival after beginning COAP was not reached for Group A, but was only 7 months for Groups B and C. As of November 1976, there were 8 of 15 Group A patients, 1 of 12 Group B patients, and 1 of 28 Group C patients who had remained disease-free from 38 to 60 (median 54.5) months and were off chemotherapy. COAP has activity in childhood ALL. However, effectiveness is markedly diminished in patients with prior bone marrow relapse.


Lack of correlation between blast cell size and length of first remission in acute lymphocytic leukemia in childhood. The bone marrow from 55 children with acute lymphocytic leukemia diagnosed from April 1969 to June 1973 were evaluated for blast cell morphology and size. Sixteen marrows contained a predominance of macrolymphoblasts (greater than 12 mu), while the remainder contained mainly microlymphoblasts. There was no correlation between blast cell size and the known front-end prognostic indicators of age and initial white blood count, nor could blast cell size be used to predict the length of initial bone marrow remission.


Phosphates and dental caries.

Phosphates and dental caries.


Respiratory distress syndrome (RDS) in a district referral center.


Screening programs for Tay-Sachs disease in North Carolina.


Early and periodic screening, diagnosis and treatment in Durham County.


Sports medicine in North Carolina.

Sports medicine in North Carolina.


Experimental chemotherapy of rat leukemia RBA-Le with cis-diamminedichloroplatinum. The antileukemic activity of cis-diamminedichloroplatinum (PDD) was studied in rats bearing myelogenous leukemia RBA-Le. Clinical picture, changes in life-span, hematological indices and weight changes were used to assess the effectiveness of the therapy. Maximum effectiveness was noted when PDD was given in combination with Methotrexate (MTX) and Poly I:C, respectively. The mean life-span of the rats treated with PDD and MTX was prolonged to 37 days that is an increase of 147 percent of the control level. Furthermore 20 percent of the treated animals survived symptom-free for more than 60 days. Out of 20 animals receiving PDD in combination with Poly I:C 6 rats survived 60 days symptom-free. In remaining 14 animals who finally died on leukemia an 85 percent increase in life-span was noted. Only slight increase in life-span was recorded in those groups treated with PDD alone and in combination with Cyclophosphamide regardless of dosage schedule. The general toxicity of PDD therapy is discussed.


Sexually transmitted enteric pathogens in male homosexual population.


Place for gonorrhea serology.

Place for gonorrhea serology.


Epidermoid carcinoma of anorectum.

Epidermoid carcinoma of anorectum.


Percutaneous needle biopsy of parietal pleura. Analysis of 50 cases.


Electrocardiogram in multiphasic health testing.


Pulmonary atresia with intact ventricular septum. Results of surgery.


Tracheobronchial papillomatosis.

Tracheobronchial papillomatosis.


Erythromycin: clinical review I. Clinical pharmacology.


Measles immunity. Report of countywide school survey.


Continuing medical education in geriatrics. Growing resource.


Fatal strongyloidiasis. In immunosuppressed patients.


Retrograde ventriculo-atrial conduction in complete heart block.


Soft-tissue sarcoma. Imaged with technetium-99m pyrophosphate.


Pancreatic pseudocyst. Simulating renal cyst.


Adenocarcinoma of breast. Arising in adenoma.


Neuropathy associated with amitriptyline. Bilateral footdrop.


Rare osteomas of paranasal sinuses.

Rare osteomas of paranasal sinuses.


Ovarian cancer. Massive calcifications resolving after radiation and chemotherapy.


Physicians' perspectives on alcohol and drug problems. Survey of members of the medical society of the county of erie.


Drugs and deer farming.

Drugs and deer farming.


Collection of blood from swine.

Collection of blood from swine.


Observations on dystocia in a Romney flock.


Fenbendazole against inhibited early-fourth-stage Ostertagia ostertagi in cattle.


The control of bloat with Teric-medicated blocks.


The district claims committee. A vital society service.


A hepatitis serosurvey of New York dentists.


Engineering safety standard of radiation.


Further study of the effect of enzyme-enzyme interactions on steady-state enzyme kinetics. This paper continues an earlier one [Hill, T.L. (1977) Proc. Natl . Acad. Sci. USA 74, 3632-3632] and presents further introductory examples. Most attention is devoted to a closed linear chain of two-state enzyme molecules with nearest-neighbor interactions. The one-dimensional Ising theory can be used here. The Bragg-Williams (mean field) approximation is introduced to deal with a one-, two-, or three-dimensional lattice of enzyme molecules, at steady state, with an arbitrary kinetic diagram. The behavior of the flux in a phase transition is noted. Finally, a treatment is given for the first effect (second "viral" coefficient) of interactions on the flux in a dilute solution of two-state enzyme molecules.


Structure of proteins: packing of alpha-helices and pleated sheets. Simple models are presented that describe the rules for almost all the packing that occurs between and among alpha-helices and pleated sheets. These packing rules, together with the primary and secondary structures, are the major determinants of the three-dimensional structure of proteins.


Local interactions in bends of proteins. Calculated probabilities of bend formation in 47 amino acid sequences of N-acetyl-N'-methylamide dipeptides, determined from a statistical mechanical analysis using empirical conformational energies, were compared with the observed fraction of bends formed in the same 47 dipeptide sequences in the x-ray structures of 20 globular proteins. Agreement between the calculated and observed fraction of bends was found for 26 dipeptides, suggesting that, for those particular dipeptide sequences, local interactions dominate over long-range interactions in determining conformational preference. Seven dipeptide sequences, all of which contained a Gly residue, had a significantly higher calculated than observed bend preference, indicating the strong influence of long-range and/or solvent interactions in those sequences. Of the 14 sequences for which the calculated was significantly less than the observed bend fraction, 13 dipeptide sequences contained at least one polar residue (Ser, Asn, or Asp) and/or an aromatic residue (Phe or Tyr), suggesting that solvent effects may play an important role in dictating the conformation in these sequences. The analysis of dipeptide sequences in the twenty globular proteins also indicated that the 4 leads to 1 hydrogen bond is not a dominant factor in stabilizing bends in proteins, and that most dipeptide sequences are capable of forming several types of bend conformations.


Thermodynamic aspects of the linkage between binding of chloride and oxygen to human hemoglobin. Oxygen isotherms of human hemoglobin measured in distilled water and in solutions of sodium chloride in the concentration range from 0.02 to 3.0 M indicate that the oxygen affinity decreases up to about 1 M salt and then begins to increase. The isotherms obtained in the range from 0.02 to 0.6 M sodium chloride, at 37 degrees and pH 7.4, have been analyzed in terms of changes in Gibbs free energy of heme ligation, resulting from the differential interaction between the chloride ion and the two forms of hemoglobin. The maximal theoretical change in Gibbs free energy that chloride ion can exert on the oxygen binding of hemoglobin amounts to 4.9 +/- 0.2 kcal/mol (21 +/- 0.8 kJ/mol) of hemoglobin tetramer. A plot of the logarithm of oxygen concentration at half saturation versus the logarithm of the chloride concentration has a slope of 0.40, suggesting 1.6 apparent chloride sites per hemoglobin tetramer. Because the interaction between chloride and hemoglobin is dependent on pH, the apparent thermodynamic linkage between chloride and oxygen binding will also include the salt dependence of the Bohr effect at pH 7.4. The fractional change in Gibbs free energy, measured as a function of the chloride concentration, can be approximated by the binding isotherm between a protein and a ligand, using an association constant of 11 M(-1). Thus, if the number of oxygen-linked chloride sites is more than one per hemoglobin tetramer, these sites must be considered independent.


On the mechanism of genetic recombination: the maturation of recombination intermediates. DNA molecules of the plasmid ColEl are normally recovered from wild-type cells as a set of monomer- and multimer-size rings. The data of this paper show that the multimer-size species are a product of genetic recombination. Multimer rings do not arise after transfection of purified monomers into bacterial host cells lacking a functional recA recombination system. Analogously, purified dimers, trimers, and tetramers, transfected into recA- cells, can replicate, but are constrained to remain in those conformations. Only upon transfection into rec+ cells can they regenerate the full spectrum of monomer- and multimer-size species. In this paper we trace the flow of genetic information from the monomer to the multimer state and back again under the guidance of the recA recombination system. The formation of multimer-size DNA rings is discussed as a natural consequence of the maturation of a Holliday recombination intermediate formed between two monomer plasmid genomes.


On the existence of a steady state in a biological system. This paper deals with the existence, uniqueness, and stability of a critical point (steady state) in the case of a macromolecular system, such as an allosteric or polysteric protein, for which the first-order kinetic equations are nonlinear. It presents a brief outline of a rigorous proof (to be given in full elsewhere) that, in a restricted but not unrepresentative system of this kind, there always exists one and only one positive critical point and that this point is asymptotically stable in the large: no matter what its starting point, the system will always approach this point by some kind of relaxation process, however complex.


Synthesis of phiX174 viral DNA in vitro depends on phiX replicative form DNA. A cell-free system that catalyzes phiX174 replicative form I (supercoiled circular duplex, RFI)-dependent phiX174 DNA synthesis has been isolated from Escherichia coli infected with phiX174 phage. The products formed with such preparations are viral strands as judged by hybridization to poly(U,G) followed by equilibrium centrifugation in CsCl. This phiX174 DNA-synthesizing involves formation of DNA-protein complexes that sediment in neutral sucrose with S values of 50, 60-70, and higher. The 50S complex contained a rolling-circle replicative intermediate DNA with an extended tail of single-stranded viral DNA. The DNA contained in the 60-70S region was a mixture of circular and linear single-stranded DNA, RFI, and RFII with an extended single-stranded tail. Such complexes have been isolated during in vivo progeny phiX174 DNA synthesis [Fujisawa, H. & Hayashi, M. (1976) J. Vriol. 19,409]. In vitro, maximal phiX174 DNA synthesis was shown to require the genetically defined proteins E. coli dna B, dna C, dna G, dna Z, rep. phiX174 gene A product, and other phiX174 coded proteins. The synthesis of phiX174 DNA is ATP-dependent and is inhibited by nalidixic acid and novobiocin but is resistant to rifampicin.


Effect of galactose oxidase, with and without prior sialidase treatment, on the viability of erythrocytes in circulation. Previous studies have shown that sialidase-treated mammalian erythrocytes were rapidly eliminated from circulation. In contrast, chicken asialoerythrocytes remained fully viable. This investigation was undertaken to ascertain the reason for this difference in behavior as well as to determine the extent of the similarity of the physiological mechanism for the elimination from circulation of asialoglycoproteins and mammalian asialoerythrocytes. To that end, erythrocytes from dogs, rabbits, and chickens were each subjected to the action of galactose oxidase (D-galactose:oxygen 6-oxidoreductase; EC 1.1.3.9) both before and after sialidase (acylneuraminyl hydrolase; EC 3.2.1.18) treatment. The viability of the autologously transfused erythrocytes in circulation was monitored by Na2-51CrO4 labeling. Galactose oxidase had no deleterious effect on the viability of dog or chicken erythrocytes, nor did it restore the viability of dog or rabbit asialoerythrocytes. On the other hand, desialated chicken erythrocytes, which were fully viable, were rendered nonviable upon treatment with galactose oxidase. It may be concluded therefore that (a) the physiological mechanism of elimination of mammalian asialoerythrocytes from circulation is not the same as that for plasma asialoglycoproteins and (b) the treatment of chicken asialoerythrocytes with galactose oxidase results in the oxidation at carbons 6 of the galactosyl- or N-acetylgalactosaminyl residues, thereby rendering the erythrocytes nonviable.


Release of ovoperoxidase from sea urchin eggs hardens the fertilization membrane with tyrosine crosslinks. One feature of fertilization is the alteration of the vitelline layer, by components released from the egg, to produce an elevated, covalently crosslinked, hard, insoluble, fertilization membrane. The following evidence indicates that crosslinking and hardening are caused by the production of diand trityrosyl residues, by oxidation of protein-bound tyrosyl residues in the presence of a peroxidase. Hardening of the fertilization membrane, as evidenced by its loss of solubility in 50 mM dithiothreitol, is inhibited by compounds known to inhibit many peroxidases. A peroxidase, here called the ovoperoxidase, is released from eggs at fertilization. This enzyme is inhibited by the same compounds that inhibit hardening and at similar concentrations. Inhibitors of the ovoperoxidase and the hardening reaction include KCN, 3-amino-1,2,4-triazole, NaN(3), phenylhydrazine, K(4)Fe(CN)(6), sodium sulfite, and glycine ethyl ester. In addition, tyramine and N-acetyltyrosine both inhibit hardening, but O-methyltyrosine does not. Dityrosyl and trityrosyl residues are found in acid hydrolysates of isolated, hardened fertilization membranes. These residues have been identified by cellulose phosphate column chromatography, thin-layer chromatography, and amino acid analysis. The amino acid data have been used to estimate that there is one dityrosine crosslink per 55,000 daltons of protein. We suggest that, by catalyzing the crosslinking of tyrosyl residues, the ovoperoxidase leads to the production of a hard fertilization membrane that blocks the entry of additional sperm. Because peroxidases are spermicidal, a secondary function of the enzyme could be to kill sperm in the vicinity of the fertilized egg.


Nucleotide sequences near the origin of replication of bacteriophage f1. The nucleotide sequence of a region related to the initiation of the reaction in which single-stranded DNA gives rise to the replicative form (complementary strand synthesis) in bacteriophage f1 has been determined. The sequence can be drawn in an extensively base-paired structure, i.e., a single hairpin-helix 55 bases long.


Chemical basis for brain-specific serine transfer RNAs. Serine tRNA from rat brain can be resolved into six isoaccepting species. Three of these species show the same chromatographic behavior as the seryl tRNAs from other rat organs, whereas the remaining species appear to be specific for brain. The isoacceptor tRNAs were purified to homogeneity by chromatography on benzoylated DEAE-cellulose followed by reversed-phase chromatography. We found that the additional species of serine tRNA in brain differ from their counterparts derived from other rat organs by a lack of a specific guanosine ribose-methylation in the dihydrouridine loop. In addition, when total liver tRNA was compared with total brain tRNA, the same degree of undermethylation with respect to 2'-O-methylguanosine was found as a general phenomenon.


Ionophores stimulate prostaglandin and thromboxane biosynthesis. The role of calcium in triggering prostaglandin and thromboxane synthesis was studied in several systems with ionophores of different ion specificities. Divalent cationophore A23187 stimulates prostaglandin and thromboxane production by washed human platelets in a concentration-dependent manner (0.3-9 muM). A23187 also induces an antimycin A-insensitive burst in oxygen utilization which is partially blocked by 5 mM aspirin or 10 muM indomethacin. Under our conditions, A23187 (up to 10 muM) does not appear to damage platelet membranes since it does not cause appreciable loss of lactate dehydrogenase or beta-glucuronidase. Mono- and divalent cationophore X537A also stimulates platelet thromboxane B(2) production and oxygen utilization, but monovalent cationophores nigericin, monensin A, A204, and valinomycin have no effect. The synthesis of prostaglandins E(2), D(2), and F(2alpha) by rat renal medulla mince is stimulated by 1 and 5 muM A23187 without changes in tissue ATP content, lactate output, or K(+) efflux. X537A, monensin A, and nigericin (all 5 muM) stimulate both prostaglandin output and K(+) efflux from renal medulla, while 5 muM valinomycin or A204 has no effect on either. None of the ionophores stimulates renomedullary prostaglandin production if calcium is omitted from the incubation medium. A23187 also stimulates prostaglandin production by human lymphoma cells, rat stomach and trachea preparations, and guinea pig polymorphonuclear leukocytes. These observations suggest a major role for Ca(2+) in stimulating prostaglandin and thromboxane biosynthesis, and also indicate that prostaglandin and/or thromboxane release may partially mediate some of the previously described effects of ionophores on cells and tissues.


Structure of a promoter for T7 RNA polymerase. We have determined the nucleotide sequence of a Hpa II restriction fragment of the phage T7 DNA containing a promoter for the phage-specified RNA polymerase. (Hpa II is a restriction endonuclease from Haemophilus parainfluenzae.) Mapping of the Hpa II restriction fragments on the T7 genome shows this promoter to be the second of tandem promoters separated by approximately 170 base pairs that begin transcription by the T7 RNA polymerase at approximately 15% of the genome. Features of the sequence involved in recognition by the T7 RNA polymerase are discussed and include the following region of hyphenated 2-fold symmetry (boxed regions are related through a 2-fold axis of symmetry at the center of the sequence shown). (See article). This sequence includes the initiation site, since the message transcribed from this fragment begins pppG-G-G-A. Combination of our results with work of others has permitted this fragment to be mapped at the junction of T7 genes 1 and 1.1. The RNA transcribed from this fragment begins within gene 1 and contains the RNase III cleavage site that lies between genes 1 and 1.1. This sequence is compared to other processing sites in T7 early message.


31P nuclear magnetic relaxation studies of phosphocreatine in intact muscle: determination of intracellular free magnesium. 31P nuclear magnetic relaxation rates for phosphocreatine in intact frog gastrocnemius were compared with those observed in model solutions at 4 degrees, a temperature at which muscle maintains its physiological state for at least 5 hr. Both nuclear Overhauser effect and spin-lattice relaxation rate (1/T1) experiments indicate that dipole-dipole interactions from the dominant relaxation path for 31P in intact muscle and model solutions, independent of phosphocreatine and Mg concentrations. Spin-spin relaxation rates (1/T2) measured by modified Carr-Purcell-Melboom-Gill spin-echo experiments suggest the importance of scalar coupling modulated by chemical exchange with free Mg. From these results, we estimate the free intracellular Mg in intact muscle as 4.4 mM and demonstrate that 31P T2 experiments can be used as a tool for studying free Mg levels with minimum disturbance of the intact cell.


In vitro biosynthesis of beta-endorphin, gamma-lipoprotein, and beta-lipotropin by the pars intermedia of beef pituitary glands. Labeled amino acids were incorporated with proteins during incubations of isolated cells from the pars intermedia of beef pituitary glands. After 3 hr of incubation with methionine and [3H]lysine, approximately equivalent amounts of labeled gamma-lipotropin and beta-endorphins were isolated. They were found to be major synthesis products of the pars intermedia. In contrast, very little labeled beta-lipotropin was recovered. Another major synthesis product of the pars intermedia was also purified. Its partial amino acid sequence and molecular weight were determined and it was concluded that this peptide cannot be identified as any known pituitary hormone or protein fragment.


Amino acid sequence of a myosin fragment that contains SH-1, SH-2, and Ntau-methylhistidine. A peptide having 92 amino acid residues and a calculated molecular weight of 10,478 was isolated from a cyanogen bromide digest of rabbit skeletal muscle myosin. It contained both proline and Ntau-methylhistidine, indicating that it arose from the portion of the heavy chain that folds to form most of the globular head of the myosin molecule. The amino acid sequence of the peptide included the two sulfhydryl groups whose alkylation modifies myosin's catalytic properties: SH-2 at position 11 in the peptide, and SH-1 at position 21. This proximity in the sequence means that SH-1 and SH-2 must be relatively close together in myosin, and several lines of evidence suggest that this region is near the catalytic or actin binding site(s) of myosin.


Reovirus mRNA can be covalently crosslinked via the 5' cap to proteins in initiation complexes. Proteins that are located adjacent to the 5' end of mRNA in initiation complexes have been detected by chemical crosslinking. Reovirus mRNA containing radioactivity exclusively in the [3H]methyl-labeled "cap," m7G(5')ppp(5')-Gm, was oxidized with sodium periodate to convert the 2',3'-cis-diol of the 5'-terminal m7G to a reactive dialdehyde. Oxidized mRNA was incubated in cell-free protein-synthesizing systems derived from wheat germ or mammalian cells, and the resulting mRNA-ribosome initiation complexes were reduced with NaBH3CN. By this chemical procedure, putative Schiff bases between mRNA 5'termini and amino groups of neighboring proteins were stabilized by reduction, yielding covalently linked protein-RNA conjugates. Under conditions of ribosome binding, a limited number of polypeptides associated with the mRNA-ribosome complexes were crosslinked, suggesting that these proteins are positioned near and may interact with the 5' end of mRNA during initiation. This method should also be useful for studying the spatial relationships between molecules in other similar nucleoprotein complexes.


Regulation of growth hormone gene expression: synergistic effects of thyroid and glucocorticoid hormones. Cultured rat pituitary cells (GC) respond to thyroid and glucocorticoid hormones by increases in growth hormone production and growth hormone mRNA. When these cells are transferred from medium containing normal animal serum (with 1.8 mug of thyroxine per dl) to a medium containing serum from a thyroidectomized calf, "hypothyroid medium" (with no detectable thyroid hormone), growth hormone production decreases markedly. In cells maintained for 5 days in hypothyroid medium, triiodothyronine induces within 50 hr a 17-fold increase in growth hormone production whereas glucocorticoids, during the same time, produce a negligible (3-fold or less) stimulation. In combination, the two hormones promote a 45-fold stimulation. In all instances the changes in growth hormone production are paralleled by changes in the levels of growth hormone mRNA as measured by cell-free translation. The transfer to hypothyroid medium and the hormonal induction do not affect the relative activities of other mRNAs whose products are detectable on polyacrylamide gels. These studies indicate that thyroid hormone can be an activator of the expression of the growth hormone gene. The results also show that triiodothyronine controls the magnitude of the effect of glucocorticoids on growth hormone mRNA, and provide a model for "permissive" triiodothyronine action. The synergistic effect of these two classes of hormone suggests that they increase levels of growth hormone mRNA by different mechanisms.


Glycerophospholipid synthesis: improved general method and new analogs containing photoactivable groups. Current methods for phospholipid synthesis involving acylation of sn-glycero-3-phosphorylcholine, lysolecithins, and related glycerophosphate esters are not satisfactory. With N,N-dimethyl-4-aminopyridine as a catalyst and moderate amounts of fatty acid anhydrides (1.2-1.5 mol equiv per OH group), diacyl or 1,2-mixed diacylphosphatidylcholines, N-protected phosphatidylethanolamines, and phosphatide acids now can be conveniently prepared in high yields (75-90%). New phospholipids containing photoactivable groups, such as trifluorodiazopropionyl, diazirinophenoxy, 2-nitro-4-azidophenoxy, m-azidophenoxy, and alpha, beta-unsaturated keto groups, in the fatty acyl chains have been prepared. These phospholipids are of interest in studies of lipid-lipid and lipid-protein interactions in biological membranes.


Use of molecular hybridization to purify and analyze albumin messenger RNA from rat liver. A new procedure is described for purification of rat liver albumin mRNA. First a population of RNA molecules is enriched for albumin mRNA by immunoprecipitation of polysomes containing albumin nascent chains. Polyadenylylated RNA is prepared from immunoprecipitates, transcribed into complementary DNA, and shown to be enriched severalfold for a particular RNA frequency component. This enriched RNA component is then purified by molecular hybridization to a limited R(0)t value (product of RNA concentration and incubation time), under conditions in which only the most abundant sequence component is annealed. Potentially, this procedure can be employed for the purification of a wide variety of mRNAs present in lesser amounts in the cell. The isolated RNA appears to be a single frequency component by hybridization to complementary DNA transcribed from itself. This RNA is a 17S species and represents 5-8% of total cytoplasmic polyadenylylated RNA. In vitro translation of the purified RNA has shown that it codes for a single polypeptide that can be identified immunologically as albumin and migrates with rat serum albumin on sodium dodecyl sulfate/polyacrylamide gels. This albumin mRNA was determined to be essentially pure by comparing its kinetics of hybridization to those obtained with rabbit alpha + beta globin mRNA and its DNA complement. The sequence complexity of purified rat albumin mRNA corresponds to 5.9 x 10(5) daltons.


Translational control by protein kinase in Artemia salina and wheat germ. The catalytic subunit of cyclic 3':5'-AMP-dependent protein kinase (ATP:protein phosphotransferase, EC 2.7.1.37) inhibits translation in Artemia salina and wheat germ extracts. It acts, as in reticulocyte lysates [Datta, A., de Haro, C., Sierra, J. M. & Ochoa, S. (1977) Proc. Natl. Acad. Sci. USA 74, 1463-1467] by catalyzing the conversion of a proinhibitor to an inhibitor of polypeptide chain initiation. Addition of ATP and either cyclic AMP or catalytic subunit promotes the proinhibitor-inhibitor conversion in crude proinhibitor preparations from A. salina embryos. The effect of cyclic AMP is due to stimulation of cyclic AMP-dependent protein kinase, present in such preparations, and is inhibited by hemin. In similar preparations from wheat germ, addition of ATP and catalytic subunit promoted proinhibitor-inhibitor conversion, but addition of ATP and cyclic AMP has little or no effect. As assayed with histone as substrate, wheat germ preparations exhibit a protein kinase activity that is not stimulated by the addition of cyclic AMP or cyclic GMP. Our results suggest that a translational control system, similar to that existing in rabbit reticulocytes and other mammalian cells, is present in organisms evolutionarily far removed from mammals.


Structural gene identification and mapping by DNA-mRNA hybrid-arrested cell-free translation. We present a simple method for directly correlating structural gene sequences in DNA with their corresponding mRNAs. This is based upon the fact that mRNA hybridized with its complementary DNA will not direct the cell-free synthesis of a complete polypeptide. Full translational activity of the mRNA is recovered upon the heat melting of the hybrid. Utilizing the rabbit beta globin clone PbetaG1, we demonstrate the application of hybrid-arrested translation for the identification of structural gene sequences within recombinant DNA molecules. In addition, the method is used to locate and order precisely several adenovirus 2 polypeptides within the viral genome.


Interactions of a photoaffinity analog of GTP with the proteins of microtubules. Tubulin dimers isolated from brain contain two GTP binding sites, a nonexchangeable site and an exchangeable site. To localize the exchangeable site, we used a photoaffinity analog of GTP, 8-azidoguanosine triphosphate (8-N3GTP), which supports tubulin polymerization in the absence of activating light. Photolysis of tubulin polymerized in the presence of 0.01 to 0.1 mM [beta, gamma-32P]8-N3GTP resulted in covalent incorporation of radioactivity only onto the beta monomer. Photolysis with 8-N3GTP also prevented any further repolymerization of the tubulin whereas like treatment in the presence of GTP had no effect. Preincubation of tubulin with GTP prevented photo-incorporation of [beta, gamma-32P]8-N3GTP whereas preincubation with ATP did not.