The maxillary cuspid and missing lateral incisors: esthetics and occlusion. When maxillary cuspids are moved mesially or if they are absent, it may be safe to assume: 1. There is no apparent change in facial contour. 2. The first premolar can serve as an adequate substitute for the cuspid, both functionally and esthetically. 3. If all spaces are closed, occlusal equilibration will usually be necessary to effect acceptable posterior occlusion. Mesiodistal contouring of the cuspids probably accentuates the problem since it seems to exaggerate any tooth size discrepancy which may exist between maxillary and mandibular teeth. 4. Unilateral space closure displays functional deficiencies more frequently on the side of closure. 5. Varying degrees of shade imbalance between the cuspid and central incisor can be expected, and the degree of contrast can be accurately predicted by using the mandibular cuspid as a guide. This is particularly important when the maxillary canines are impacted or unerupted.


Facial morphology and activity of temporal and lip muscles during swallowing and chewing. The correlations between facial and bite morphology and the activity in the temporal muscle and in the musculature of the lip during swallowing and chewing were studied in 50 girls, aged 9-13 years. The activity was recorded electromyographically by determining the maximal mean voltage amplitude and morphologically by analysis of profile roentgenograms and dental casts. The activity in the lower lip during the swallowing was not correlated with any of the variables of the facial morphology with the exception of the width of the upper dental arch. On the other hand, the activity of the upper lip during swallowing, as in the anterior and posterior portions of the temporal muscle, was correlated with a number of variables used for measuring facial form. The activity was low in girls with a facial shape with anterior inclination of the maxilla and mandible, small face height, and pronounced prognathism. The activity in the upper lip during chewing  varied, as in the lower lip, independently of facial form, while the activity of the temporal muscle during chewing showed the same relation to facial form as during swallowing. The number of chewing cycles required for trituration of the test media (apples and peanuts) was negatively correlated with the number of teeth and with age. This was interpreted as adaptation in such a way that the number of cycles decreased with development of the dentition.


Abnormalities found on cephalometric radiographs. The films of 513 consecutive patients from a private practice were brought to Children's Hospital, Los Angeles for reading in their Radiology Department. Eighteen films, 3.5 percent, were classified as having abnormalities or pathologies present. In addition, there were seven findings labeled as interesting, although normal, because they are usually not present on the lateral head film. The lateral orthodontic cephalometric head film can disclose a variety of pathoses which are significant to the physician. The orthodonitist sholld study the lateral head roentgenogram for nondental abnormalities.


Iris and anterior chamber involvement in leukemia. A case of acute lymphocytic leukemia is described with bilateral ocular involvement, including iris, trabecular meshwork, and anterior chamber. Microscopic findings are correlated with clinical findings. All cases reported to date (5) in the American literature with microscopically confirmed leukemic iris infiltrate have been of acute lymphocytic leukemia.


Treatment of busulfan-induced pancytopenia. A patient with busulfan-induced pancytopenia and recurrent, thrombocytopenic bleeding was treated prophylactically with random-donor platelet transfusions and later with HLA-matched platelets from a sibling. The pancytopenia remitted after five months. The course and alternative modes of therapy of busulfan-induced pancytopenia are discussed. This disorder may be reversible if the patient can be supported through an initial period of severe pancytopenia.


[Changes in membrane proteins in the erythrocytes of patients with hemolymphoblastosis not directly involving the erythroblastic line]. An analysis of red cell membrane proteins in acute and chronic lymphatic leukaemia, Hodgkin's disease, lymphosarcoma, and myeloma was carried out. The electrophoretic pattern after solubilisation in urea or SDS was examined, along with migration on cellulose acetate or acrylamide in different buffers. Protein acid, basic and neutral amino acid percentages were also determined. An increase in low molecular weight and faster anodic migration proteins was noted in the lymphoblastoses, whereas the amino acid spectrum of these proteins showed percent changes in the case of some amino acids, particularly glutamic acid, phosphoserine, lysine and histidine. The alterations observed were compared with those noted previously in other haemoblastoses, congenital haemolytic and anhaemolytic blood diseases, and endoglobular or acquired metabolic defects in a closer assessment of their significance.


Hepatitis B in Australian Aborigines and Torres Strait Islanders: georgraphical, age and familial distribution of antigen subtypes and antibody. Hepatitis B antigen of subtype ay is prevalent in Australian Aboriginal populations, but only subtype ad was found in Torres Strait Islanders. Both subtypes were found in Caucasion hepatitis patients and blood donors from Brisbane. Antigenaemia in Aborigines was more prevalent in Northern Territory than in Queensland, and in males in all areas, but different age distributions were found in Queensland (maximal over 30 years) and Northern Territory (maximal under 30 years). Family clustering was striking in all populations where genealogies were known. In a limited survey antibody was found to be more common than antigen in all Aboriginal groups, the prevalence increasing with age with a peak at 11 to 30 years. Hepatitis B virus infection was equally common in some areas of high and low arbovirus activity providing some evidence against arthropod transmission of hepatitis B virus in these areas.


The effect of rifampicin on liver morphology in tuberculous alcoholics. Seventy-nine consecutive patients receiving rifampicin in combination with isoniazid and another drug, were found to have an 8-3% incidence of acute clinical liver disease. Half the patients (36) were advanced alcoholics and almost all cases of hepatitis came from this group. Fifteen of the 36 were thought to have evidence of pre-existing liver disease and were studied by means of serial liver biopsies. Most of those with pre-treatment abnormalities of liver function developed abnormalities in their biopsies, not attributable to alcohol. In one patient active chronic hepatitis is believed to have followed irregularly taken rifampicin. Those patients with both normal pretreatment liver function and biopsies did not develop histological abnormalities. The dangers of irregularly taken self-administered rifampicin are stressed. It is suggested that rifampicin is contraindicated in alcoholics with initial abnormal liver function tests.


Lung function in asymptomatic cigarette smokers--the single breath nitrogen test. The modified single breath nitrogen (SBN) test and simple spirometry were used to study the lung function (LF) of 101 asymptomatic, cigarette smoking and 20 non-smoking men aged 18 to 39 years. Abnormal LF was demonstrated in 39% of smokers. An abnormal SBN test was found in 28% of the light and 56% of the heavy smokers but only 3% were spirometrically abnormal. Only one non-smoker had an abnormal SBN test. Closing volume and slope of the alveolar plateau, which are both measured from the SBN test, correlated poorly suggesting that the abnormality caused by smoking may differ among smokers. The SBN test is a simple test which is sensitive enough to detect LF abnormalities in young smokers. The significance of the detected abnormalities in relation to the development of chronic obstructive lung disease is not presently known.


Outpatient screening tests for primary aldosteronism. The assessment of basal plasma aldosterone and renin concentrations, and urinary aldosterone excretion has been compared with their values after a suppressive test employing mineralocorticoid induced volume expansion in five patients with primary aldosteronism and in patients with essential hypertension. Reliance upon measurements of basal plasma aldosterone concentration, plasma renin/aldosterone ratio and urine aldosterone excretion alone proved unsatisfactory for distinguishing patients with primary aldosteronism. However these patients, in contrast to those with essential hypertension, showed elevated values or no decrease in plasma aldosterone concentration following three days treatment with 400 mug fludrocortisone (florinef) daily. It is proposed that the assessment of basal plasma renin activity together with florinef suppression of plasma aldosterone are the most effective and convenient outpatient screening procedures in the diagnosis of primary aldosteronism.


Monitoring immune function during immunosuppressive therapy. Twenty-nine patients with a variety of connective tissue disorders were studied for the effects of immunosuppressive therapy on non-specific parameters of immune function. Baseline studies prior to therapy showed a frequent incidence of anergy (13%) lymphopenia (31%) and abnormal PHA response (43%). Despite these abnormalities in untreated patients it was possible to show an even higher incidence of anergy (31%), lymphopenia (66%) and abnormal PHA response (77%) following immunosuppressive treatment. The changes in lymphocyte count and PHA response were found to be statistically significant. It was found, paradoxically, that delayed hypersensitivity responses improved following institution of therapy in three patients. Clinical efficacy of immunosuppression correlated with lymphopenia and depressed PHA responses; in particular in the five patients with uncontrolled disease, these parameters were normal. Lymphocyte counts and PHA responses are the most simple and informative procedures to monitor immunosuppression in patients.


Analysis of two-category data from small independent samples. An exact probability test for the comparison of cure-rate (or any other 2-category response variable) among three treatments is presented in detail; Extension of the method to larger contingency tables is also shown. It is suggested that the exact method should be used if the sample size for a particular investigation is small and/or when the chisquare test gives a probability level near borderline statistical significance.


Neonatal brain tissue embolism in the lung. A brain tissue embolus was observed in a major pulmonary artery in the right lung, in a neonate who died from intracranial haemorhage 36 hours after delivery. This is the fifth documented case in a neonate and the only one in whom survival had occurred beyond one hour. Brain tissue emboli in the pulmonary circulation occur very rarely; it has been described in adults and children with head injuries. In newborn infants with severe congenital malformations of the central nervous system, brain tissue has been found growing in the lungs; the possibility of this being the result of prenatal brain trauma with embolization has been raised. In newborn infants, pulmonary brain tissue embolism as a result of birth trauma has been reported only very rarely; as far as the authors are aware, only four such cases have been documented. In view of the rarity of this condition, it was thought that the present case merited reporting.


Penicillin-induced haemolytic anaemia associated with microangiopathy. The development of a penicillin-induced haemolytic anaemia was studied in a patient with microangiopathy following an average daily dose of five million units of penicillin G (total dose 46 million units). It has been proposed that the combination of the benzylpenicilloyl hapten with exposed or altered erythrocyte antigens, induces an autoimmune response. In this particular case, it is suggested that erythrocyte membrane damage has predisposed to immune drug-mediated red cell damage.


Meliodosis presenting as encephalitis.

Meliodosis presenting as encephalitis. Meliodosis is an infectious disease caused by Pseudomonas pseudomellei, an organism that is common in South-East Asia, the Caribbean and northern Australia. In the author's case report the disease presented as an encephalitic illness with fever and epileptic fits in a five-year-old Chinese boy. The case illustrates one of the many forms of this illness. The patient, though very ill, made an excellent recovery. The report discusses the manifestations, diagnosis and management of Meliodosis.


Diabetes and associated variables in the South Australian Aboriginal. Diabetes of a predominant maturity-onset type has been identified as being up to ten times more prevalent in South Australian Aborigines than in Caucasians. On the evidence provided, nutritional status and obesity are thought to be dominant in the aetiology of the hyperglycaemia, although relative hyperinsulinaemia in full blood Aborigines suggests a significant racial genetic effect. It is suggested on these and other grounds that the diabetic genotype may represent a factor of previous survival advantage to the Aboriginal, now rendered deleterious by urbanization. The degree of hyperglycaemia, and its association with hyperlipidaemia, obesity, retinal arteriovenous changes and abnormal electrocardiographic findings, accentuates the significance of the diabetes, and underlines the serious need for ongoing nutritional education in these communities.


Blood pressures and electrocardiographic findings in the South Australian Aborigines. Blood pressure measurements were recorded in 522 adults and 141 10-19 year-old full and part blood Aborigines in five communities. The means for systolic and diastolic blood pressures at 40 years were close to those reported for Europeans, although below this age, values tended to be lower, and above 40 years tended to be higher than those reported in the Tecumseh study. Hypertension, as defined by the Princeton criteria, was present in 29%, more often in the men (1-6 to 1-0), and eight subjects satisfied the criteria for hypertensive heart disease (HHD). 522 electrocardiograms were recorded on adult subjects at five Aboriginal communities and classified according to categories of the Minnesota code. Of the 210 abnormalities observed, minor T wave inversions and minor S-T segment depression were the most commonly encountered, and were more frequent in female subjects. Q wave changes typical of myocardial infarction was found in 5% of the tracings and occurred mainly in older men. If hypertension and certain ECG codes are assumed to be "risk factors" for the development of clinical ischaemic heart disease (IHD), the urbanized Aboriginal had a higher prevalence compared with Caucasian subjects of the Busselton study. "Probable" and "suspect" ECG changes of IHD, although mainly in the older subjects, were found to be associated with hyperglycaemia, as recognised in Western society. It is postulated that urbanized Aborigines are prone to cardiovascular degenerative disease to a similar or possibly larger extent than Caucasians.


Visual acuity and retinal changes in South Australian Aborigines. Eye examinations were carried out a four Aboriginal reserves. Of 361 Aboriginal adults tested, 64 had a visual defect (visual acuity of 6/9 or worse) in each eye, a prevalence of 18%, with an additional 79 (22%) with a similar loss of acuity in one eye only; these were more frequently seen at the urbanized reserve of Koonibba. Only one full blood Aboriginal child within the less urbanized communities had a reduced visual acuity, whereas seven (10%) part blood children at a more urbanized reserve had reduced vision in both eyes, with a further nine (13%) in one eye only, not unlike figures quoted for South Australian school children. Vascular changes in the fundus oculi were observed and occurred more often when hypertension and/or hyperglycaemia were present. They consisted of arteriovenous crossing changes (26%), swelling of the retinal veins (3%) and altered light reflex (41%) and were not infrequently seen in the younger adult (20% of adults under 30 years had AV crossing changes and 46% had widened light streak). Analysis suggests that, although hypertension and hyperglycaemia are related to retinal vascular changes, other factors, as yet unidentified, are present in the Aboriginal population under consideration.


Assessment of the value of factor VIII procoagulant and antigen ratio in the diagnosis of carriers of haemophilia. The detection rate of carriers of haemophilia was evaluated using the ratio of factor VIII procoagulant activity (VIIIc) to factor VIII antigen (VIIIag). In normals the corelation coefficient of VIIIc to VIIIag was 0.82. In 15 obligatory carriers of haemophilia whose VIIIc and VIIIag levels were studied in the authors' labotatory there was no correlation between VIIIc and VIIIag and the ratio of VIIIc to VIIIag was below the lowest normal value in 12 (80%). In all five obligatory carriers whose VIIIc levels were estimated in the referring institution and VIIIag levels in the authors' laborary the ratio was below the lowest normal value. In 17 sisters of haemophiliacs studied here or referred for estimation of VIIIag only, an abnormal ratio was found in seven. Of 25 mothers of haemophilic children without a family history of haemophilia carriers is close to that expected on theoretical grounds but the interpretation of the results is complicated by the small numbers of patients all of whose studies were performed entirely in the authors' laboratory. In two normal individuals, one of who was on a contraceptive pill, there were no fluctuations of the ratio of VIIIc to VIIIag during the menstrual cycle. In one obligatory carrier with a normal ratio there was also no fluctuation. It is concluded here that a measurement of the ratio of VIIIc to VIIIag is a valuable adjuvant in genetic counselling in haemophilia.


Lithium associated thyroid disease--a report of 14 cases of hypothyroidism and 4 cases of thyrotoxicosis. Thyroid function was assessed in 80 patients receiving long-term lithium therapy. Three of the 80 patients were biochemically hypothyroid and a further patient was receiving thyroxine for lithium associated hypothyroidism. A further eight patients had elevated TSH levels and eight patients had subnormal serum triiodothyronine levels. After a 24 month follow up period seven of the 80 patients have developed clinical hypothyroidism. One patient had elevated thyroid parameters and clinical features of mild hyperthyroidism. Additional clinical and laboratory data are included from seven patients with lithium associated hypothyroidism and three patients with lithium associated thyrotoxicosis who were not included in the survey population.


Hypertension due to renal tuberculosis: assessment by renal vein renin sampling. A 36-year-old man with asymptomatic hypertension was shown to have destruction of the right kidney due to renal tuberculosis. The peripheral renin level was normal, but renal vein renin sampling showed predominant renin secretion from the right kidney both in basal samples and after acute stimulation of renin release with intravenous diazoxide. Nephrectomy has resulted in marked reduction of blood pressure without treatment one year after operation. The findings support the predictive value of renal vein renin sampling when hypertension is associated with renal parenchymal disease, even when peripheral renin is normal.


Relevance of vascular structural and smooth muscle sensitivity changes in hypertension. This is a mini-review of the vascular changes that occur in experimental hypertension. Augmented vascular resistance and reactivity appear to be due to an increase both in wall thickness and in vascular smooth muscle sensitivity. The increase in wall thickness is an adaptive change that is secondary to the increase in arterial pressure; the altered smooth muscle sensitivity occurs in the absence of an increase in arterial pressure and hence may initiate the increase in vascular resistance and reactivity of experimental hypertension. Studies of subcellular function indicate that changes in smooth muscle sensitivity may be caused by an increase in cell membrane permeability and an altered handling of calcium by its subcellular sequestering system.


Use of systolic time intervals in studying hypertension. Systolic time intervals were measured in 54 hypertensive patients divided into three groups according to severity of hypertension, variability of blood pressure levels and presence or absence of a hyperkinetic heart. The three groups were: borderline hypertension (BLH), fixed essential hypertension (FEH) and hyperkinetic essential hypertension (HEH). Systolic time intervals (STI) provided information indicating an increased cardioadrenergic drive in BLH and HEH. This was supported by finding that propranolol abolished the increased contractility found at rest in BLH and HEH.


Possession trance in a semi-urban community in Sri Lanka. A survey of possession trance states in a semi-urban population of 7653 identified 37 subjects. The manifestations of the trance, and its course and outcome are outlined. The characteristics of the subjects, including presence of psychiatric disorder, are compared with that of the total population, and significant differences are noted. Four psychodynamic syndromes observed are described with illustrative case vignettes. The functions subserved by possession behaviour are reviewed, and comparisons are drawn between personal possession, ritual possession, and altered states of consciousness in Western society.


Psychological factors as a prediction of success in duodenal ulcer surgery. An attempt was made to relate the outcome of surgery to psychosocial factors in an unselected series of 30 male patients with duodenal ulcer. Though statistically significant differences did not emerge on the psychosocial parameters studied, patients with good surgical results were less likely to give histories of preoperative anxiety or depression or to show evidence of these at interview. They also had lower ratings on Hamilton Rating and Deprivation Scales, and were more likely to have hopeful expectations of operation and positive attitudes towards previous medical treatment. Patients with psychiatric illness or psychological deprivation having sugery for chronic duodenal ulceration, can expect almost as good a surgical result as those without these difficulties. They are unlikely to show increased psychiatric morbidity, postoperatively.


Electroencephalographic study of mentally retarded twins. The EEGs of twenty-five pairs of twins, one or both of whom were mentally retarded, were studied. The concordance rate for mental retardation in monozygotic twins was higher than that in dizygotic twins. The vast majority of cases of mental retardation were considered to be caused by genotype but some exogenous causes were observed in discordant monozygotic twins. Paroxysmal discharges in the EEG especially those of centrencephalic type were suspected to be bioelectrical expressions of a transmissible cerebral susceptibility which may easily lead to intellectual deterioration by brain damage or epilepsy.


A mirror image Out-patient study at a depot phenothiazine clinic. This Mirror Image Study, at a specialised clinic, has shown a significant reduction in days spent in Hospital. Individual features of the sample include sex and age difference in the sub-groups for dosage, duration of treatment and anti-Parkinsonian medication. Preliminary cost-effectiveness analysis has been reported.


Genetics, drug dependence and schizophrenia. It has been suggested that drug dependence is a substitute for schizophrenia in young patients and that drug dependence protects them from schizophrenic breakdown. Assuming the correctness of the genetic basis for schizophrenia, it was postulated that persons known to be dependent on heroin would have a higher genetic loading for schizophrenia if the hypothesis was true. An examination of the family backgrounds of 82 drug dependent persons failed to find supporting evidence for the belief that drug dependence is a substitute for schizophrenia in young persons.


An epidemiological study of autistic and psychotic children in the four eastern states of Australia. Data on general behavioural and etiological characteristics of a sample of 146 autistic and psychotic children from the four eastern states of Australia are presented. Both inter and intra study comparisons are made with reference to a number of factors considered significant in childhood psychosis. The findings accord with those of similar overseas studies on most factors although methodological and diagnostic differences limit the conclusions. A notable finding was that of an excess of "organic" indications in a sub-group of early onset, severly withdrawn "autistic" chhildren suggesting that further neurological and EEG testing of autistic children is desirable.


Potency in psychotherapy.

Potency in psychotherapy. This paper defines therapeutic potency in terms of constructive as opposed to destructive intervention. In judging the degree of success in psychotherapy we may use either a medical or a growth model. Whichever criterion is adopted the conclusion stands that potency will be at a maximum whenever the therapist selects the most efficient technique for working with his client regardless of the school which gave birth to it. An eclectic approach views the differences between schools as exaggerated by the use of divergent psychological models and terminology, and sees value in various explanatory concepts such as 'reinforcement' 'conditioning', 'insight' and 'cognitive restructuring'.


Cultural aspects of delusions: a psychiatric study of Egypt. This paper deals with the cultural elements of the delusions of a sample of Egyptian psychiatric patients. After examination of clinical records, interviewing psychiatrists and reviewing literature, the author reaches the conclusion that the content of the patient's delusion varies directly in relation to his social class. For most of the low class men and women, the delusional symptoms, either megalomaniac or persecutory were fantasied in terms of the cultural religious institutions. Middle and upper class patients, however, much more frequently "secularized" their restitutive narcissistic and self esteem delusions in terms of science and class conception of power.


[Long-term results of intermittent massive therapy (protocol HIM-T.M.I.) in children with acute lymphoblastic leukemia]. Long-term results of treatment of 45 children with acute lymphoblastic leukemia are reported. The maintenance therapy of remission was biweekly MITX in a Control Group (20 patients) and combination of monthly therapy (T.M.I.) oral MTX, 6MP and CP, at very high doses and reinduction with Pred and VCR, every 6 weeks in the Study Group (25 patients). The median duration of remission was 10 and 26 months, respectively. Six patients of the Study Group are still in their first complete hemission for 57 to 95 months (median of 75). CNS leukemic was the initial site of relapse in 55 and 56% of  the groups, respectively, but in the Central Group it took place at 10 month and in the Study Group of median of 22.5 months after remission was achieved. In 16 patients of both groups, TMT prolonged the second remission 5.5 to 7.5 months. The median duration of survival was 17 months (Control Group) and 46 months (Study Group). The difference was due to longer hematologic remissions in the second group. Up to Feburary, 1976, all patients of the Control Group have died and 7 children of the Study Group are alive, one for 76 months but has had several relapses and 6 patients (24%) without evidence of disease from 56 to 96 months after diagnosis (median 77 months) and all are now out of antileukemic treatment from 18 to 48 months (median 31 months). These 6 patients are considered probably cured. Toxicity was more severe in the Study Group but never threatened the patient's life.


Endomyocardial fibrosis associated with daunorubicin therapy. A case of endomyocardial fibrosis in a patient with acute myeloblastic leukaemia treated by daunorubicin is reported. The pathological findings are indistinguishable from tropical endomyocardial fibrosis.


Effects of X-rays on vascular function in transplanted tumours and normal tissues in the mouse. The effects of X-radiation on the Nembutal-induced redistribution of the cardiac output in two types of transplanted mouse tumours and some normal mouse tissues have been investigated, using rubidium-86 and 125I-human serum albumin. Irradiation causes an increase in 86Rb uptake (relative blood perfusion) by the tumours of anaesthetized mice, but has little or no effect in non-anaesthetized mice. The increase is dose- and time-dependent. Tumour plasma space is not significantly affected by radiation and Nembutal. Muscle blood perfusion is severely decreased in anaesthetized mice and is not affected by radiation, at least within the time limits of the experiments. This means that radiation-induced functional vascular changes in normal and neoplastic tissues follow different time courses. On the basis of the present results, and of the results of other authors, it is argued that irradiation damages the vasculature of tumours in such a way that it becomes more sensitive to changes in systemic blood pressure.


Blast crisis of chronic myeloid leukaemia (CML). I. Presentation simulating acute lymphoid leukaemia (ALL). Seven patients presenting as an acute leukaemia caused difficulty in diagnosis. The lymphoid appearance of the balst cells either initially or during treatment suggested acute lymphoid leukaemia (ALL). In each case the Philadelphia chromosome was shown to be present thus suggesting that these cases were examples of chronic myeloid leukaemia (CML) presenting in blast crisis without a detectable chronic phase. The implications of these findings are discussed and the difficulty in achieving a precise diagnosis in the acute leukaemias is emphasised. Cytogenetic analysis should be carried out whenever the type of acute leukaemia present is of critical importance.


Antigenic relationships in calf thymus and human leukemic cell terminal deoxynucleotidyl transferase. Antibody to purified terminal deoxynucleotidyl transferase (nucleosidetriphosphate : DNA deoxy-nucleotidylexotransferase, E.C. 2.7.7.31) from calf thymus was prepared in rabbits using terminal deoxynucleotidyl transferase crosslinked to bovine serum albumin. These antibodies, partially purified by 60% ammonium sulfate precipitation and Sephadex G-200 column chromatography, produced one precipitation band with calf thymus terminal deoxynucleotidyl transferase on immunodiffusion. This antibody preparation also inhibited the in vitro activity of terminal deoxynucleotidyl transferase from calf thymus, acute leukemic lymphoblasts and Molt-4 cells but not that of DNA polymerases alpha, beta and psi from these cells


A mathematical model of the chemotherapeutic treatment of acute myeloblastic leukemia. Based on our previous mathematical model of the acute myeloblastic leukemic (AML) state in man, we superimpose a chemotherapeutic drug treatment regimen. Our calculations suggest that small changes in the protocol can have significant effects on the result of treatment. Thus, the optimal period between drug doses is the S-phase interval of the leukemic cells--about 20h--and the greater the number of doses administered in a given course treatment, the longer the rest interval should be before the next course is administered. For a patient with a "slow" growing AML cell population, remission can be achieved with one or two courses of treatment, and further suppression of the leukemic population can be achieved with continued courses of treatment. However, for patients with a "fast" growing AML cell population, a similar aggressive treatment regimen succeeds in achieving remission status only at the cost of very great toxic effects on the normal neutrophil population and its precursors.


Chromosomes and causation of human cancer and leukemia. XXI. Cytogenetically unusual cases of leukemia. Three male patients with leukemia were found with banding techniques to have unusual cytogenetic pictures in the cells of their marrow, spleen or blood. Case No. 1 (78 yr old) was that of a Ph1-negative CML with a missing Y in the blood (cultured without PHA) and marrow cells. The patient is still alive and responding to therapy. Case No 2 (54 yr old) was considered prior to admission to have either CML or AML, but was shown, in fact, to be in the blastic phase of CML; all the cells in his marrow and spleen were Ph1-positive, but with no evidence of a translocation. Other karyotypic findings (+8, +11, +13, +21) frequently encountered in the blastic phase of CML were present in the cells of this patient. Case No. 3 (50 yr old) with AML was shown to have a Ph1 resulting from a standard translocation, i.e., [t(9;22) (q34;q11)], in a substantial number of the cells in the marrrow and blood (cultured without PHA). The implications of these unusual findings are discussed in relation to the chromosomal pictures usually encountered in these states.


Remission induction in adult acute lymphocytic leukemia. Use of vincristine and prednisone alone. Therapy for acute lymphocytic leukemia (ALL) has been less successful in adults than in children. Many centers treat all adult leukemia with the same regimen. We have used vincristine and prednisone for initial therapy in 14 adults with ALL since 1971 and have followed a treatment regimen developed for childhood ALL for subsequent therapy as well. Complete remissions were attained in 13, and complications and duration of hospitalization were minimized with this nonmyelotoxic regimen. Central nervous system "prophylactic" therapy was also well tolerated in these adult patients. However, remission duration and survival in our series were similar to those reported by others. That complete remission can be attained in a high percentage of adult patients with ALL through use of relatively nontoxic treatment demonstrates the importance of selecting out this group of patients from all adults with acute leukemia.


Chromosomes and causation of human cancer and leukemia. XVII. Banding studies in acute myeloblastic leukemia (AML). Chromosomes were studied in the bone marrow and/or blood cells from 38 patients with acute myeloblastic leukemia (AML). The initial analysis with conventional Giemsa staining revealed that 16 of the 38 patients with AML studied had chromosomal abnormalities. The cells of these 38 patients (16 with abnormal karyotypes and 22 with normal karyotypes) were re-examined with Q- and G-banding techniques. Twenty-two patients with conventionally stained normal karyotypes did not show any abnormalities, even with banding techniques. Three cases had a common translocation between the long arm of No. 8 and No. 21, i.e., [t(8;21)(q22;q22)], the so-called prototypic karyotype. Two cases had a 45, XX,-21 karyotype; and three cases had trisomy of the long arm of chromosome No. 1. The banding patterns revealed that in two of the three latter cases, the presence of the trisomy of the long arm of No. 1 apparently occurred late in the disease. Therefore, it is possible that the trisomy of the long arm of No. 1 might bear a relationship to selective growth advantage of the leukemic cells in some cases with AML. The presence of extra No. 8 and No. 9 chromosomes and deletion of the long arm of No. 7, frequently reported in several leukemic disorders, were also found in the present cases, but with other chromosomal abnormalities. Chromosomes No. 6,No. 15,No. 19,No. 20, and X were not involved in any structural and/or numerical changes. The present data suggest that some chromosomal changes are nonrandom in AML and that further chromosomal studies may lead to a division of AML patients into subgroups on the basis of their karyotypes.


The chromosomes and causation of human cancer and leukemia. XVIII. The missing Y in acute myeloblastic leukemia (AML) and Ph1-positive chronic myelocytic leukemia (CML). The occurrence of a missing Y chromosome was investigated in the bone marrow cells of male individuals, i.e., 255 controls, 73 with acute myelocytic leukemia (AML) and 59 with Ph1-positive chronic myelocytic leukemia (CML). The incidence in controls of individuals with 45,X cells increased with age, particularly after the age of 60. In AML, 45,X metaphases were detected in two patients over 70 years of age, but the leukemia seemed to have involved the 46,XY cells rather than the 45,X cells. Four of the six patients with No. 8-No. 21 translocation and two of the 16 with major karyotypic abnormalities (MAKA) exhibited a missing Y in the leukemic cells in addition to other karyotypic aberrations. Four of the Ph1-positive CML patients exhibited a missing Y in all or nearly all the cells in the bone marrow along with the Ph1. In one patient, additional chromosome abnormalities involved the 46,XY,Ph1 rather than the 45,X,Ph1 cells. The genesis of the missing Y in CML cells may be related to the presence of the Ph1, though apparently the patient's age also plays a role. It is our hypothesis that 45,X or 45,X,Ph1 cells are resistant to the development of further chromosomal abnormalities and, thus, reflect their resistance to being involved in an acute leukemic process.


Familial acute myelogenous leukemia with associated C-monosomy in two affected members. A family is described in which five members, three sibs in one branch and two sib cousins in another, died of acute myelogenous leukemia. C-Monosomy was found in the marrow of two of the sibs. C-deletion aneuploidy has been increasingly reported in conjunction with abnormal myelopoiesis. It is possible that this chromosomal aberration may serve as a useful clinical marker of the emergence of a leukemic state.


Malignant lymphoma, lymphoblastic.

Malignant lymphoma, lymphoblastic. Among the malignant lymphomas of the diffuse, poorly differentiated lymphocytic type, a cytologically distinctive form can be recognized. It is composed of immature lymphoid cells that are indistinguishable from the cells of acute lymphoblastic leukemia (ALL). Although these neoplasms usually have been classified as malignant lymphoma, lymphoblastic type, they contain, in addition to lymphoblasts, prolymphocytes in varying proportions. On the basis of the nuclear morphology, malignant lymphoma of the lymphoblastic type, (MLLB) can be further divided into those with and those without convoluted nuclei. In our series both groups had the following clinical features in common: 1) frequent occurrence in children and adolescents; 2) clinical presentation with mediastinal masses in 50% of cases; 3) a high incidence of bone marrow and perpheral blood involvement during the course of the disease; and 4) rapid progression of the disease with a median survival of 8 months. Our observations indicate that nuclear convolutions are helpful but not essential for the recognition of a clinicopathologic entity which is histologically and cytologically characterized by 1) the immaturity of the lymphoid cells indistinguishable from the lymphoblasts and prolymphocytes of ALL and 2) a high mitotic index. Because of the frequency with which MLLB progresses into ALL, systemic therapy may be indicated even before this progression is hematologically evident. This indicates the need for morphologic recognition of this malignant lymphoma regardless of the presence of nuclear convolution, age of the patient, and site of presentation.


Relation of disease stage to humoral and cellular impairment of spleen reticuloendothelial system depression in a rat leukemia. In the rat leukemia studied there is an early reversible depression of reticuloendothelial system (RES) function followed by a late-stage secondary depression, culminating in death, associated with an infiltration of leukemic cells into the bone marrow and spleen. In one set of experiments to assess RES function, isolated spleens of nonleukemic rats were perfused with blood from rats in progressively advanced stages of the leukemia. In a reciprocal set of experiments, isolated spleens of rats in comparable stages of the leukemia were perfused with blood from nonleukemic rats. The clearance of 99mTc-sulfur colloid from the blood perfusate was used as a test of RES function. In the first set, clearance was depressed in nonleukemic spleens perfused with blood collected from rats 1 hr after they had been inoculated with tumor cells, and it was more markedly depressed in a late stage of the leukemia 6 days later. Perfusion of nonleukemic spleens with blood from rats in intermediate stages of the leukemia did not depress clearance. In the reciprocal study, clearance was depressed in spleens of rats that were inoculated with tumor cells 1 hr before perfusion with nonleukemic blood. Clearance values were at the control level in spleens of rats in all other stages of the leukemia when calculated on the basis of total spleen weight. When calculated on a unit weight basis, clearance values were lower in the enlarged spleens of rats in advanced stages of the leukemia. The results indicate that impairment of RES clearance of 99mTc-sulfur colloid is associated with alternations in the humoral content of the blood of this leukemic rat. There is indirect evidence to suggest that in the terminal stage of the leukemia an impairment of splenic RES cells to clear 99mTc-sulfur colloid may develop secondarily.


The phenotypes of variant clones of Friend mouse erythroleukemic cells resistant to dimethyl sulfoxide. The cloning efficiency of Friend erythroleukemic mouse cells is reduced by approximately 50% at every generation when the cells are continuously grown in the presence of 2% dimethyl sulfoxide (DMSO). Clones of murine erythroleukemic cells, resistant to the effect of the drug, have been selected from a nonmutagenized, hemoglobin (Hb)-inducible clone 745. The variant cells are present in the population with a frequency of 3 X 10(-5) cells. Twelve clones, characterized by different growth rates, have been examined in more detail. All the clones can grow in the continuous presence of 2% DMSO, are noninducible or poorly inducible by the drug, and consist of a homogeneous proerythroblastic cell population and a low number of Hb-synthesizing cells, except for clone R22S in which about 30% of the cells synthesize Hb. All but one (R2102) of the noninducible clones can be induced to synthesize Hb to various degrees by treatment with 1 mM butyric acid for 4 days. One clone (R1Z) forms colonies at a much higher efficiency in 2% DMSO than in nonselective plates, suggesting that it is conditional for DMSO. These and other resistant clones could be useful for the study of the mechanisms of induction of terminal differentiation.


Regulation of bone marrow myeloblast proliferation in chronic myeloid leukemia. The in vivo [3H]thymidine-labeling index of bone marrow myeloblasts and myelocytes was determined for 9 hematologically normal individuals and 20 Ph-positive chronic myeloid leukemia (CML) patients in the chronic phase of their disease. The mean labeling index of myeloblasts from CML patients when the white blood cell (WNC) count was lower than 20,000/cu mm (42.4%) was not significantly different from that of normal myeloblasts (49.9). This index was found to be significantly (p less than 0.05) decreased to an average of 20.9% when the WBC count was higher than 40,000/cu mm. The mean labelling index of CML myelocytes was not significantly influenced by the level of WBC. The data presented indicate that such variations in the labeling index of the leukemic myeloblasts represent changes of their proliferative activity related to the level of WBC. It is concluded that the proliferation of CML myeloblasts is sensitive, to a certain degree at least, to the size of the myeloid cell population in the body or a subclass of it.


Rapid and selective induction of erythroleukemia in female Donryu rats by continuous oral administration of 1-ethyl-1-nitrosourea. Three groups of female Donryu rats were given continuously 1-ethyl-1-nitrosourea, 400, 200, or 100 mg/liter, in their drinking water. Leukemias developed in 94 of 104 (92%) rats surviving more than 6 experimental weeks. Of the leukemias, the erythroleukemias were induced most frequently, rapidly, and selectively. Other types of leukemias were found in a few rats of the high-dose group and, in some cases, in rats of the low-dose group. Tumors were also induced in the digestive tract, mammary glands, ear duct, and other organs, but their incidences were lower than 24%.


The results of surgical treatment combined with intra-arterial infusion of anti-cancer agents in osteosarcoma. Since 1963, regional intra-arterial infusion of anti-cancer agents combined with surgery has been used in the treatment of 56 patients with osteosarcomas. The histologic examination of amputated limbs after prolonged intra-arterial infusion therapy showed remarkable degeneration and necrosis throughout wide areas of tumor tissue. The overall estimated 5-year survival rate improved from 4 to 31.4 per cent. In cases where the infusion period was of more than 3 weeks duration, the estimated 5-year survival rate was 43.8 per cent. The period from operation to pulmonary metastasis was prolonged and the incidence of pulmonary metastasis within the first year was markedly decreased. The use of intra-arterial infusion prior to surgery coupled with postoperative bronchial arterial infusion and systemic chemotherapy improved the prognosis in osteosarcomas.


Primary osteosarcoma of the skull.

Primary osteosarcoma of the skull. In 33 cases of primary osteosarcoma of the skull in a relatively old age group, the sex ratio and poor prognosis is the same as in osteosarcoma of long bones. However, patients in the second decade of life free of neurologic disease have a better prognosis.


Spinothalamic fibres, pain conduction and cordotomy. Description of four cases of cordotomy for intractable pain in which autopsy could be performed. In two of the cases the lesion had been placed (unintentionally) in the posterior quadrant of the spinal cord with good results as to the abolishing of pain. It is concluded that the conduction of pain and temperature stimuli is not restricted to the anterolateral part of the spinal cord but that this conduction may also take place along fibres in the posterolateral quadrant. A further conclusion is that the results of cordotomy are related to the number of cut fibres.


A dynamic study of genotype-environment interaction with egg laying of Tribolium castaneum. Within-line family selection was carried out at an optimum (33 degrees C) and two stress temperatures (28 degrees C and 38 degrees C) for increasing egg number laid by virgin females of Tribolium castaneum from the 7th to the 11th day after adult emergence. A control was maintained throughout the experiment. Two replicated lines were selected at each temperature and all selected lines were tested in each of the three environments. Direct and correlated responses to selection in different environments have been analysed in order to study implications of genotype-environment interaction on the selection outcome. Although selection at the optimum environment has been the most effective it did not confer the specialisation needed for performance in stress environments. However, selecting in adverse environments led to a broader range of performance over environments, which in one case (38 degrees C) included the optimum one. The degree of adaptation to adverse environments was mainly determined by the magnitude of the genetic correlation between performances in the adverse and the optimum environments. The evolution of such correlations through selection has also been investigated.


Genetic studies on cycloheximide-resistant strains of Schizosaccharomyces pombe. Cycloheximide-resistant mutants of Schizosaccharomyces pombe were isolated either as spontaneous mutants or after mutagenic treatment with nitrous acid, UV and N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Twenty-three spontaneous mutants and 64 induced mutants were analysed genetically. Crosses revealed that at least four loci, designated cyh1, cyh2, cyh3 and cyh4 are responsible for resistance. Alleles of cyh1 show good growth on either high (100 mug/ml) or low (40 mug/ml) concentrations of cycloheximide whereas alleles at the cyh2, cyh3 and cyh4 loci gorw well on 40 mug/ml but poorly on 100 mug/ml. Some alleles at the cyh2 and cyh3 loci are also temperature sensitive (ts), the ts phenotype being conferred by the same gene as the resistance. In diploids, cyh1 and cyh4 are re-essive to wild type whereas cyh2 and cyh3 are semi-dominant. There was no intragenic complementation between three cyh1 alleles. Cross-resistance to trichodermin and anisomycin was shown by cyh2, cyh3 and cyh4 but not cyh1. Most cyh1 alleles, of spontaneous and UV origin only, were cold sensitive (cs) at 14 degrees and some of these were also cycloheximide dependent at the same temperature. It is suggested that the cyh1 and cyh4 genes are involved in ribosome formation or function and the other loci probably affect the uptake of cycloheximide by the cells.


Genetic analysis of enzyme polymorphisms in plaice (Pleuronectes platessa). Genetic analysis was performed on five enzyme systems (G3PDH; GPI-A; GPI-B; PGM; MDH-A) in plaice (Pleuronectes platessa) collected in spawning condition from the North Sea. Conventional crosses, induced gynogenesis and induced triploidy were performed. The data conclusively demonstrated the inheritance of isozymes by co-dominant alleles at individual loci for each system. No linkage was observed but tests did not include MDH nor the possibility of linkage between G3PDH and GPI-A. Some anomalous segregation ratios were observed, particularly a deficiency of heterozygotes for GPI-A, but the data were largely in conformity with Mendelian expectations. At the PGM locus, five independent anomalous individuals were scored and interpreted as mutations with a mutation rate of 1.1 X 10(-3) per gamete. Recombination with the centromere was assessed and induced triploidy and cross-over values of 41 per cent for PGM, 19 per cent for MDH-A and 9 per cent for GPI-B were derived on the assumption of complete interference. Amongst the parent fish, genotypic and phenotypic frequencies were largely consistent with the expectations of the Hardy-Weinberg Law, and allelic frequencies were not significantly different between year of collection or location of collection ground.


Supergenes in polymorphic land snails. I. Partula taeniata. The general colour of the shell in Partula taeniata is controlled by at least two loci. One of these (C) has a series of six alleles which determine the yellow (Y) and neutral brown (N) series of colours. Alleles for darker colours are dominant to those for lighter colours, but dominance is not always complete. The pink (P) colours are determined by a second locus (P) which modified the expression of the lighter alleles of the C locus. Orangeshell colour segregates with yellow but its allelic relationship is unknown. Colour of the lip is controlled by a locus (L) with pink lip dominant to white lip. The colour of the spire is determined by a locus (S) with dark (N4) spire dominant to light spire. An intermediate spire colour shows the same pattern of inheritance and may represent the effect of another allele. Banding of the shell is dominant to absence of bands, with two loci (B1 and B2) determining the type of banding. An allele at B1 produces the frenata pattern; an allele at B2 produces zonata; together they produce lyra. All the loci for which linkage data are available are linked so strongly that the whole array may be considered a supergene. Self-fertilisation takes place primarily during early reproductive life. About 20 per cent of the young of the first mating of an individual are produced by selfing, but over the whole reproductive span the frequency is only about 2-5 per cent. There is inconclusive evidence for heterozygote advantage of banded individuals.


Supergenes in polymorphic land snails. II. Partula suturalis. The colour and banding of the shell of Partula suturalis are controlled by a single locus (M) with a series of at least six alleles. MX, giving apex as a homozygote, is dominant to MF1, giving frenata, which is dominant to the other alleles. MF2 is similar to MF1 except in its relation with MA. MF2MA produces bisecta and provides a striking example of a heterozygote that is qualitatively different from both homozygotes for the alleles producing it. MA gives atra as a homozygote and is dominant to MC and MS. MC, giving cestata as a homozygote, is recessive to all except MS. MS, giving strigata, is the universal recessive. It is suggested that the locus may be complex. The direction of coiling of the shell is determined by the H locus with HS (sinistrality) dominant to HD (dextrality). The expression of coiling is delayed by one generation, the maternal genotype determining the phenotype of the offspring. M and H are not linked. Self-fertilisation occurs infrequently and non-randomly.


Spontaneous recombination in males of Drosophila simulans. Spontaneous recombination in males of Drosophila simulans is reported for the first time. Both second-chromosome and third-chromosome male recombination was observed in lines that had been captured from natural populations.


Bias in the estimation of regression coefficients in the analysis of genotype-environmental interaction. Potential bias in estimates of regression coefficients when the environmental index in joint regressional analysis is the mean of all genotypes is examined in relation to assumptions of random and fixed genotypic effects and the error structure of the experiment. A modification is suggested.


[Segmentation analysis of the oro-dental health of a population of young adults]. The results of an epidemiological study of the oral conditions in a representative sample of 2000 adult inhabitants of Strasbourg, 16 to 30 years old, have been analyzed by the segmentation method. The gingival conditions were essentially dependent on dental plaque, followed by age, socio-professional status, as well as DMF/S and sex. Dental caries was mainly related to age and then to gingival conditions and sex. The amount of calculus and the socio-professional conditions intervened afterwards. In all conditions, the females had more carious lesions than the males.


[Oro-facial behavior of smokers].

[Oro-facial behavior of smokers]. A preliminary study was conducted on twenty patients to study the oro-facial behaviour when smoking a cigarette. Such a study was realized with an electromyograph, an integrator and a magnetoscope which were combined. Two types of smokers were found: "a correlated" type for whom time and degree of activity of the different muscles had a tendency to become similar; in the "dissociated" type the two preceding parameters had a tendency to move away from each other, at least for certain muscles. Each smoker presented a very stable behavioural motor pattern.


Oral Candida, debilitating disease and atrophic lesions of the tongue. Central papillary atrophy of the tongue (CPA) was significantly more common in diabetics than in non-diabetic control subjects. Candida species were cultured from 46% of diabetics. The only species insolated from diabetics with atrophic glossitis was Candida albicans. Almost one in five of the diabetics gave positive smears for candidal mycelia. The correlation between atrophic lesions and the finding of candidal mycella in smears was statistically highly significant (P less than 0.01) but a cause-and-effect relationship was not established. Histological examination of a case of diabetic CPA suggest that this may be predisposed by micro-vascular degeneration.


[Attempt at a comparison of healthy coronal dentin and carious coronal dentin]. The amino acid composition of normal human coronal dentine has been studied. The amino acid composition of carious coronal dentine was compared to that of the normal coronal dentine. The study was conducted on non demineralized samples. The results lead to a reconsideration of the so-called "normal dentine" in relation to different parameters: tooth age, sample location. A precise comparison between normal and carious dentine appears difficult to make.


Glycosaminoglycans of human dental pulp. Dental pulps were obtained from sound human permanent molars and premolars. The pulps were treated to remove lipid, protein and nucleic acid and glycosaminoglycans were finally isolated by ethanol precipitation. Electrophoretic examination and CPC-cellulose profiles revealed the presence of hyaluronic acid, dermatan sulphate, chondroitin 4 sulphate and chondroitin 6 sulphate. Hyaluronic acid accounted for only a low percentage of the total glycosaminoglycan content while dermatan sulphate was present in unusually high amounts. Chondroitin 4 and 6 sulphates represented the major glycosaminoglycan fraction.


[Development of the fetal mandible of rats in transplants onto the chorioallantoic membrane of chick embryos]. The evolution of mandibles of 15 to 17 days old fetal rats has been studied after transplantation on the chorio-allantoïc membrane of chicken embryos. The histological study of the samples grafts showed a remarkable adaptation of Meckel cartilage to the transplantation medium as well as the continuation of the ossification processes of membranous and endochondral origin. An important thickening of the oral epithelium, accompanied by an increased keratinization appeared in the grafts collected at 17 days "in utero". Only one tooth germ could be found in a graft collected at 17 days "in utero".


An experience in dental education in Sweden. On the basis of a one-year experience as a visiting professor at the University of Lund School of Dentistry in Malmmo, Sweden, the author discusses dental education in the Swedish system and compares it to its American counterpart. The power and independence of the department chairmen and the absolute dependence on research productivity as the criterion for advancement in the academic hierarchy are pervading influences in Swedish dental education. It is difficult to undertake curriculum study and revision in Sweden and to achieve coordination in the educational program. Research efforts in the Swedish schools are of high quality and are remarkably prolific.


Factors associated with career choice among women dental students. This paper describes factors associated with women's decisions to enter dentistry including timing of decision, external influences, previous dental experience, and dempgraphic characteristics. Analyses comparing data from male students are provided. On the basis of responses from 66% of all women dental students and a systematic comparison sample of men enrolled in 1974, both sexes were found to possess similar values,motivations, and reasons for pursuing dentistry. Male and female dental students differed significantly, however, in time of career decision, factors influencing this decision, work and educational history of parents, and the student's previous dental-related work experience.


Strong Vocational Interest Blank scores and differential attraction to in individualized curriculum. Research suggests that preference for and effectiveness of instructional methods vary with individual differences in personality and motivation. Students who had taken the Strong Vocational Interest Blank (SVIB) and were completing an individualized course in preclinical dentistry made a hypothetical choice between individualized and traditional curricula. As compared with students preferring the regular option, those preferring the individualized optipn scored higher on interests in scientific, aesthetic-cultural, and adventuresome activities and on motivation for academic achievement and professional specialization. On occupational scales, they were more similar to those in biological science and social service and resembled less those in skilled trades, business and accounting, and sales. The groups did not differ in Dental Aptitude Test scores or grades. Findings from the SVIB and questionnaire data suggest that individualized programs are especially suited to students with high intellectual interests, academic motivation, self-discipline, and organization. Implications for individualized programs are discussed.


Effect of an extramural program of dental care for the special patient on attitudes of students. All too frequently, courses and clinical experiences are introduced in dental education merely becausse they seem to be the popular things to do. Unfortunately, however, just as frequently such experiences are inappropriately planned and developed; they fail to achieve the basic purpose behind their introduction. This study reports such a failure in dental education. A course in dental care for the special patient was hastily and inadequately conceived and implemented. Thecourse did not achieve its objective'in fact, had it been allowed to continuein subsequent years, it could have done more harm than good. The means exist for evaluating whatever id done, and the educator should be willing to accept failure as well as success. The recognition and identification of failure can infact serve a worthwhile purpose, to the advantage of the system, if the elementscontributing to the failure are identified and proper changes are introduced.


Future role of biomaterials in dentistry and dental education. It is possible to make predictions on materials research and on its impact if one understands the background of materials science and appraises the constraints on research and practice. In the past ten years some significant advances have been implemented in dental practice. On the basis of these advances, some very optimistic predictions can be made for the next ten years. However, in some areas, little progress was made, and there are some reasons to believe that this limited success will continue. Planning in research and dental education must be based on realistic appraisals of research productivity.


Perceptual and motor training for the acquisition and retention of psychomotor skills in dental amalgam restorations: class I in the mandibular first molar. From a study of 72 dental students during amalgam restoration using four training methods (psychomotor, mental, psychomotor and mental, and conventional)--one method for each 18 students--the following conclusions are drawn: (1) It is economically feasible to develop and utilize self-paced instructions without the aid of instructors for the acquisition of psychomotor skills. (2) Training through self-paced analytical programs results in higher retention of the acquired skills than training through  conventional training methods.


Peer review of a dental curriculum: how one school did it. The Curriculum Committee of the Medical College of Georgia implemented a formal course-by-course review of their entire dental curriculum after first adopting positions with respect to faculty philosophical concerns. The strategy adopted was to evaluate the articulation of the various courses into a coherent whole by using reviewers who taught related courses but were outside the particular department or discipline. In general, findings indicated a satisfactory degree of articulation. Some reviewers reported serendipitous outcomes for themselves as a result of reviewing the courses of others.


Human cardiorespiratory and analgesic effects of intravenous diazepam and local anesthesia. The only clinically detectable cardiovascular changes after intravenous diazepam administration are a moderate fall in systolic blood pressure and a rise in pulse rate. But it will produce significant cardiovascular changes, principally the lowering of total peripheral resistance and stroke volume. The drug has a long history of safety but is not totally innocuous. It is suggested that if diazepam is used in combination with methohexital, consideration should be given to the additive effects on total peripheral resistance.


Patient education on cigarette smoking: the dentist's role. Cigarette smoking is a major cause of illness and premature death in our society. Secondhand smoke is a definite irritant to nonsmokers and can, under certain conditions, have potentially serious effects on the nonsmoker's health. Despite the facts, millions of persons continue to smoke. Although no single health professional reaches all smokers, the dentist has a particularly good opportunity to reach his patients who smoke. By advising and couseling, providing helpful literature, creating an environment in which smoking is prohibited, and setting a good example, the dentist can have a singificant part in his patients' education on cigarette smoking. If the dentist's efforts are even partially successful in modifying behavior of the patient who smokes, much illness will be avoided and many lives saved.


A simulation spatial model of the spread of foot-and-mouth disease through the primary movement of milk. A computer model was constructed to mimic the 1967-8 foot-and-mouth epizootic in Shropshire and Cheshire, but the daily spatial distribution of outbreaks was randomized. This pattern of outbreaks was then examined to determine what percentage of outbreaks would fulfil and arbitrary set of criteria for milk-lorry-borne disease, or the primary movement of milk. Some 21% of herds visited subsequent to a 'source farm' were affected, as were 4% of herds visited after any infected herd. The relevance of these results to the true risk of disease through the primary movement of milk off affected farms is discussed.


Some observations on the epidemiology of toxoplasmosis in Canada. Between 1961 and 1974, 11934 samples of serum were tested by the Sabin-Feldman Dye test for the presence of antibodies to Toxoplasma gondii. Analysis of high-titred sera suggested that a 6-year cycle of high disease prevalence occurred across Canada. In addition, a decline in the percentage of positive reactions each year in the Fall. The suggestion that this decline was due to dry conditions during the summer months was supported by the observation that differences in the prevalence of toxoplasma infection in ten Canadian cities were related to their average summer rainfall. The significance of these observations in relation to the epidemiology of toxoplasmosis in this country is discussed. The influence of patient age on the prevalence of infection was also investigated; the results obtained suggested that at least 75% of infants with high antibody titres against T. gondii had obtained these antibodies by placental transfer from their mothers.


Latent injury in frozen-thawed bacteriophage T4Bo. Two interesting new phenomena have been observed in suspensions of T4Bo bacteriophage which were frozen to temperatures below the eutectic temperature of the salt (sodium chloride) in the suspending medium. Approximately 10% of the phage appeared to survive such a phase change as determined by plaque titre. However, exposure of these survivors to ultrasonic vibration or repeated freezing showed them to be hypersensitive and thus latently injured. The hypersensitivity was lost on incubating the phage at 37 degrees C. for 3 hr. Furthermore, following a eutectic phase change, the surviving phage could be inactivated by rapid cooling to -90 degrees C. followed by slow rewarming. Such inactivation cannot be accounted for by accepted theories of freezing injury.


Morphological manifestations of freezing and thawing injury in bacteriophage T4Bo. Electron microscopic observation of negatively stained preparations of frozen and thawed suspensions of T4Bo phage clearly separated the morphological changes produced produced by low-temperature salt denaturation from those produced by eutectic phase changes. Salt denaturation caused contraction of tail sheaths. Eutectic phase changes appeared to cause two separate lesions. Firstly the tail sheath was disjointed 18-22 nm. below the collar and the tail core was disjointed at 40-60 nm. below the collar, giving rise to separated heads with a small tail remnant, and separated tails in which the sheath remarkably remained in its extended form. Secondly, tears were seen in the head membranes of particles with collapsed empty heads. In all the experiments the percentage of normal phage particles counted electron-microscopically was close to the percentage of viable phage as determined by plaque assay.


Nalidixic acid as a selective agent for the isolation of enterobacteria from river water. Enterobacteria are more resistant to nalidixic acid than the majority of other Gram-negative organisms isolated from river water, so allowing their selection on MacConkey agar containing nalidixic aicd. Selection is further improved by anaerobic incubation which, with nalidixic acid, virtually eliminates oxidase-postivie strains such as Pseudomonas or Aeromonas.


Salmonellosis in wild mammals.

Salmonellosis in wild mammals. One thousand two hundred and sixty-nine freeliving, wild mammals, representative of 16 species from estates in Berkshire, Oxfordshire and Surrey, were examined for the presence of salmonellas. Salmonella typhimurium was isolated from 1 and S. dublin from 7 house mice (Mus musculus). There were no isolations from the other species examined. It was concluded that the house-mice infected with S. dublin acquired the organism from experimentally infected cattle. The wild mammal population does not at present appear to constitute a reservior for infection of domestic animals.


A comparative field trial, conducted without pre-treatment census baiting, of the rodenticides zinc phosphide, thallium sulphate and gophacide against Rattus norvegicus. The effectiveness of the single-dose poison treatments of farm rat infestations, analysed by comparing the weights of the post-treatment census bait takes in covariance with the weights of the prebait takes, showed that treatments with 2-5% zinc phosphide, 0-3% thallium sulphate or 0-3% gophacide were equally effective and significantly better than were treatments with 1% zinc phosphide or 0-1% thallium sulphate. The methodology and sensitivity of different analyses are also considered.


The effect of desert conditions on the reactivity of Libyan schoolchildren to a range of new tuberculins. This study was carried out to investigate the effect of desert conditions on the pattern of delayed hypersensitivity to mycobacteria in school children aged 6-10 and 11-18 years. A new range of tuberculins prepared from ultrasonic lysates of living mycobacteria belonging to 12 different species was employed. Three centres were chosen for study, a sea port and two desert towns differing greatly from each other. The results obtained were compared with those of a previous study using the same reagents in Kenya. As expected both the range of mycobacterial species to which the children reacted, the rate of acquisition of specific hypersensitivity with age and the total percentage of children reacting to individual reagents differed from centre to centre. The harsh desert conditions of Ajdabia produced the least, and the proximity of the people's dwellings to those of their farm animals in Kufra produced the most positive reactors to essentially environmental species. The greatest number of reactions to our Tuberculin were found in Benghazi where the cosmopolitan urban conditions probably lead to a high contact with open cases of tuberculosis. As assessed by skin test reactivity, immunization with BCG in Libya was much less effective than in Kenya. The interpretation of the differences between the results from the different test centres and between those for Libya and Kenya are discussed.


Studies on the 1967--68 foot and mouth disease epidemic: incubation period and herd serial interval. The incubation period during this epidemic was studied using both a spectral analysis-cum-filtering method and analysis of case histories. Using spectral analysis, the modal herd serial interval was estimated to be 8--10 days based on the record of the daily number of outbreaks and an adjusted cattler series. The case histories tended to confirm these estimates but indicated that the serial interval varied considerably between species. The filtering method revealed that the herd serial interval apparently changed during the epidemic. For the first 4 weeks the interval was 8 days, while in the latter stages it was about 2 weeks.


A surface antigen influenza vaccine. 1. Purification of haemagglutinin and neuraminidase proteins. Influenza virus was centrifuged in a KII rotor through a sucrose gradient containing Triton N101, a non-ionic surfactant. The micelles of surfactant formed a band in the gradient. As virus particles passed through the surfactant, the haemagglutinin and neuraminidase proteins were stripped from the surface and remained near the surfactant micelles. The residual virus particles sedimented into a denser region of the gradient and were thus separated from the haemagglutinin and neuraminidase antigens. Fractions containing the surface antigens were pooled and Triton was removed by phase-separation at the cloud point.


A surface antigen influenza vaccine. 2. Pyrogenicity and antigenicity. Conventional influenza vaccine containing whole virus particles purified on a zonal centrifuge is pyrogenic and can cause systemic and local adverse side effects. An improved vaccine was therefore prepared which contained only the surface antigens of the virus adsorbed to aluminium hydroxide. The antigenicity of this vaccine was compared with conventional vaccine in chickens. Both vaccines induced similar titres of serum haemagglutination-inhibition and neuraminidase inhibition antibody. The dose response curves, however, were different. The surface antigens at vaccine strength without aluminium hydroxide were of negligible pyrogenicity in rabbits.


Laboratory characteristics of an attenuated influenza type A (H3N2) virus ('Alice' strain). The Alice strain of live attenuated influenza virus was obtained by selection of a gamma inhibitor-resistant strain from a virus recombinant between A/PR/8/34 (HON1) and A/England/42/72 (H3N2). Its behaviour in vitro and in vivo was studied. Three marker systems were investigated: resistance to serum inhibitors, growth capacity at high temperature and low sensitivity to amantadine hydrochloride. In ferrets the strain was found to be attenuated and immunogenic. Passages in man, animals and eggs have not affected its resistance to gamma inhibitors.


Coated bedpans: their cleaning and disinfection. This paper reports on tests of cleaning and disinfection of stainless steel bedpans which have been coated with either a silicone grease or polytetrafluoroethylene (PTFE). The coatings were applied manually using an aerosol spray (silicone grease and PTFE), and by an industrial process (PTFE). Soils used comprised (i) British Standard Soil (B.S., 1966), (ii) human serum albumin labelled with technetium-99m (HSA-Tc), and (iii) a suspension of Streptococcus faecalis in broth. Tests of cleaning and disinfection were carried out in automatic washing and steam disinfector machines. Results show that aerosol spraying impairs the cleaning process but that bedpans coated by the industrial process with PTFE are superior to uncoated bedpans.


Experimental phycomycosis in mice; examination of the role of acquired immunity in resistance to Absidia ramosa. Attempts were made to stimulate acquired immunity to experimental Absidia ramosa infection in mice. Unprotected animals inoculated with large doses of A. ramosa spores frequently developed acute phycomycosis of the central nervous system. Mice previously exposed to sub-lethal doses of spores showed a high resistance to subsequent challenge with A. ramosa. No consistent increase in resistance was observed in mice vaccinated with killed A. ramosa spores, hyphal walls, intracellular mycelial antigens or various combinations of these, with Freund's incomplete adjuvant. Antibodies to soluble mycelial antigens were inconsistently present in the sera of mice vaccinated with sub-lethal doses of viable spores. They were generally present in the sera of animals vaccinated with mycelial extracts of hyphal walls but not killed spores. Delayed hypersensitivity reactions to A. ramosa mycelial antigens could usually be elicited by intradermal tests in mice exposed to viable spores but irregularly in those vaccinated with non-viable preparations. Positive reactions were also frequently given by older mice not deliberately exposed to A. ramosa. Although mice previously exposed to viable A. ramosa spores were highly resistant to intravenous or intracerebral challenge with this fungus, they were more likely to develop persistent local granulomata on subcutaneous injection of spores than were unvaccinated animals.


An appraisal of sewage pollution along a section of the Natal coast after the introduction of submarine outfalls. A bacteriological survey on the distribution and occurrence of coliforms and pathogenic indicators of pollution within the surf-zone and near-shore waters along a section of the Natal coast before the use of submarine outfalls with reported previously. In that report more than half the beaches in the region were found to be of Class IV or III quality. After the submarine outfalls became operational, ten further sampling runs were made. A considerable improvement in the sea-water quality was apparent, most of the beaches being regarded to Class II or I, notably in the bathing areas.


Clothing for use in clean-air environments. Disposable plastic two-piece suits were compared with conventional cotton suits, gowns, and plastic aprons by nurses in a burns unit. The plastic suits allowed fewer micro-organisms to be dispersed into the environment than the other garments but were less comfortable.


Activation of the alternative pathway of complement in childhood acute lymphoblastic leukemia. Sequential studies in children with acute lymphoblastic leukemia have demonstrated that at diagnosis or relapse there is defective utilization of complement by the alternative pathway. Thus, the sera of 17/18 patients fail to completely consume C3 to C9 when incubated with zymosan or cobra venom factor (CoF). This underutilization is due to a specific inhibitor of C3 activation which has been partially isolated. By remission, the inhibotor disappears and the CoF and zymosan assays return to normal. In addition, serum levels of C3 and factor B are elevated at the time of diagnosis or relapse but fall to below 3 S.D. from the mean in nearly 60 per cent of the cases during induction therapy. Similarly, serum C4 levels which are normal at diagnosis fall to less that 3 S.D. from the mean in 7/12 cases during treatment. Low C3 levels correlate well with factor B values, suggesting that if C3 to C9 are utilized after the inhibitor has been eliminated, such utilization occurs primarily through the alternative pathway. Presumably, as illustrated by the low C4 levels, this activity is mediated by the ampliciation loop of the alternative pathway involving classical pathway generation of C3b.


Acid maltase deficiency (type II glycogenosis). Morphological and biochemical study of a childhood phenotype. Pathological and biochemical data are reported on a 4(4)/12-year-old male patient with a severe myopathic disorder, hepatomegaly, recurrent pulmonary infections ending fatally. Combined morphological and enzymatic studies on muscle biopsy led to the diagnosis of acid maltase deficiency (Type II glycogenosis). On post mortem examination, lysosomal glycogen storage is found in skeletal muscles and liver, while heart and central nervous sytem are spared. Both hydrolytic and transferase activities of acid maltase are absent in cultured fibroblasts, heart, liver and postmortem skeletal muscles. That in the biopsied skeletal muscle only, the transferase activity alone is deficient while the hydrolytic function is maintained at low normal levels correlates well with the abnormal structure of the glycogen stored in that muscle. However, these findings on biopsied muscle cannot be reconciled with the absence of both functions and the presence of normal glycogen in other biopsied tissues or in postmortem specimens from the same patient.


Attrition: possible mechanisms of compensation. Attrition, or wear of the occlusal surfaces of the teeth, may not only be physiologically normal, but necessary for function. Since occlusal wear must lead to reduction in tooth length, significant dimensional changes in facial morphology are inevitable unless mechanisms exist to compensate for attrition. Secondary dentine formation, alveolar growth, and adaptive changes in the masticatory muscles can provide this compensation, and may be part of a complex system by which an effective level of masticatory function is maintained even when attrition is extreme.


Disturbances in the contraction and co-ordination pattern of the masticatory muscles due to dental restorations. An electromyographic study. Recent Swedish publications report that a large number of patients suffer from the mandibular dysfunction syndrome. Some theories assume that this syndrome is the result of a disturbance in blood flow through the maxillary artery. The present authors suggest, that the syndrome is caused by a disturbance in the pattern of contraction of the masticatory muscles. This hypothesis is based on the assumption that the human periodontal membrane contains mechanoreceptors which are able to exert reflex control over the pattern of contraction of the muscles during chewing. If the pattern of stimulation of these receptors is modified following dental restoration, then this could result in a disturbance of the neuromuscular pattern of the masticatory apparatus. In order to test this hypothesis, an electromyographic study was carried out in three volunteers and eight patients. The results of this study support the view that there are receptors in the human periodontal membrane which are able to control the pattern of contraction of the masticatory muscles. The hypothesis that the mandibular dysfunction syndrome is the result of a disturbance in the pattern of contraction of these muscles is pursued further in the discussion.


Characterization of porosity of isostatically pressed and sintered nickel-base powdered metal. Characterization of the pore structure of compacted and sintered parts made from a nickel-base powder was accomplished using the mercury porosimetry method. The theoretical density values for the sintered specimens varied from 56.3 to 96.7% which corresponds to a porosity of 43.7 to 3.3%. A maximum interconnecting median pore diameter of 21 mum resulted from a -80/+200 mesh powder compacted at 138 MN/m2 and sintered for 2 h at 1250 degrees C. Photomicrographs of the same sample showed that it had a maximum pore diameter of 200 mum. The interconnected pore volume decreased with decreasing particle size of the powder, increasing compaction pressure, and increasing sintering temperature. Mechanical properties of tensile strength, yield strength, elastic modulus and percentage elongation were correlated with the pore structure. Proper selection of particle size, compaction pressure, sintering times and sintering temperatures should permit parts with controlled porosity characteristics to be produced that possess adequate mechanical properties for application as implants.


Adaptation of amalgams to cavity walls.

Adaptation of amalgams to cavity walls. The adaptation of amalgam fillings to the cavity walls has been studied. Cavities were made in human teeth and filled with four different amalgams: (1) amalgam with an expansion of approx. 10 mum/cm after 48 h; (2) amalgam with no dimensional change after 48 h (balanced); (3) amalgam with a contraction of approx. 10 mum/cm after 48 h; and (4) amalgam with a contraction of approx. 20 mum/cm after 48 h. The filling surface and parts of the surrounding enamel were planed, polished and studied under the microscope. The degree of contact between the amalgam and the cavity wall and the number and dimensions of the marginal defects were observed. Fillings made from expanding or balanced amalgams mostly had good contact with the cavity wall, and the marginal defects were small and scattered. Around fillings made from contracting material, a slit formation was observed, and in these areas fractures of both the amalgam and the enamel margins had regularly changed the slit to a V-shaped gap 10-20 mum wide. Greater defects exceeding 50 mum were also frequently observed. The results showed a gradual decrease in the quality of adaptation from fillings made of expanding material to those made of contracting material. It was further shown that the polishing procedure caused fracturing of both the unsupported enamel and amalgam margins thus widening the defects considerably.


Periodontal conditions in patients 5 years following insertion of fixed prostheses. Pocket depth and loss of attachment. The oral hygiene, gingival condition, pocket depth and loss of attachment were studied during a period of 5 years in a group of patients (114) who had been treated with fixed dental protheses. Eighty-four per cent of the subjects had received periodontal therapy prior to the prosthetic treatment. During the study the subjects participated in an oral hygiene programme. Crown margins were located sub-gingivally, at the gingiva, and supra-gingivally. Initially 65% of the crown margins were sub-gingival compared to 41% 5 years later. When the crown margins were located sub-gingivally there was an increase in Gingival Index scores 2 and 3, in pocket depth, and in loss of attachment compared to a supragingival placement. However, most of the alterations were small.


Late results of treatment with partial dentures. An investigation by questionnaire and clinical examination 13 years after treatment. Ninety-nine people who were fitted with partial dentures in 1959 were invited to take part in an investigation 13 years later. A questionnaire was answered by fifty-eight, which means a frequency of 81% if allowance is made for an explainable loss. Of the sixty-eight partial dentures in these fifty-eight patients, twenty-three were still being used, fourteen patients had had their original partial dentures replaced by new ones and three by a fixed bridge, while seven had been replaced by complete dentures. Twenty-one were no longer used and had not been replaced. Of the fifty-four patients who originally had a complete upper denture and a partial lower denture, thirty were still available. Following an invitation to take part in a clinical review, twenty-seven (90%) co-operated. Most of the patients were in need of treatment (for caries, periodontitis and/or prosthetic treatment). The periodontal injuries were rarely serious. A correlation was found between good oral hygiene and good results of treatment.


Soft lining materials: composition and structure. An analysis of five proprietary acrylic soft lining materials revealed that they can be classified into two groups. The first of these groups (Soft Oryl and Coe Soft) resemble the tissue conditioners in composition in that their liquid component contains no monomer. A study of their mechanical properties may reveal that these materials should, in fact, be classified as tissue conditioners. The second group (including Palasiv, Virina and Coe Super Soft) were more conventional acrylic materials which differed in the amount of plasticizer and the type of acrylic monomer used in the liquid component and in the nature of the polymer component.


Assessment of reliability of cineradiographic recording of temporomandibular joint movements. As part of a cineradiographic study of temporomandibular joint movements, the reliability of the apparatus and techniques has been assessed. The areas of concern were the radiographic procedure, tracing apparatus and tracing technique. To assess the accuracy of the radiographic procedure, anatomical and radiographic measurements of mandibular condyles were compared. A range of variation of 0-46--0-8 mm was found, which compared favourably to the only previously published investigation. The use of mechanical devices simulating the fundamentals of mandibular movements suggested that the cineradiographic record showed paths of opening and closing separated more widely than occurred in vivo. The reliability of the tracing apparatus was assessed by calculated misalignments and found to be acceptable. The subjective error in tracing cineradiographic films by a regular observer was investigated by a point location error method. The error was found to be small and within acceptable limits.


Some morphological aspects of the meatus acusticus externus in connection with mandibular movements. A method is described to measure volumetric variations in the meatus acusticus externus caused by the movements of the mandible. Simultaneous registration of EMG activity and gnatho-sounds demonstrated that after tooth contact a slight decrease in volume, followed by some increase in volume takes place within 20-30 ms. The fast volume changes, during and after tooth contact, seem to be correlated to the speed of closure.


Relation between functional disturbances of the masticatory system and some anthropometric, physiological and psychological variables in young Swedish men. The relation between functional disturbances of the masticatory system and anthropometric, physiological and psychological variables was studied in 248 Swedish men, aged 18-25 years. No physiological variables and only a few anthropometric variables were found to be correlated with symptoms of functional disorders or to the state of the dentition. Thus, for example, face height was greater in the presence than in the absence of disturbances of the occlusion (mainly occlusal interferences). The psychological variables were found to be most closely correlated with symptoms of functional disorders and the state of the dentition. Men with clinical dysfunction had a lower general level of intelligence than men without. Social adaptation at school was poor in those who reported parafunctions. Men with parafunctions, frequent headache, general muscle and joint symptoms and balancing side interferences had low emotional stability compared with those without such symptoms. Individuals completely free from symptoms of functional disturbances had high emotional stability.


The effect of anodic polarization on the tensile strength of dental amalgam. The effect of corrosion upon dental amalgam was studied by measuring the effect of anodic polarization on its tensile strength. A conventional tensile testing method using dumb-bell shaped specimens deformed along the long axis was employed. The results showed a significant reduction (27%) in the mean tensile strength, due to the anodic polarization of conventional amalgam, whereas the strength of the high Cu-containing Dispersalloy amalgam was unaffected by polarization. When the diametral tensile strengths of polarized and unpolarized conventional amalgam and Dispersalloy specimens were compared (ADA Specification No. 1), no significant difference in strength was observed. These results indicate that the anodic corrosion of gamma2 phase network in the conventional amalgam fillings can be directly attributed to a reduction of tensile strength which would be manifested clinically as marginal breakdown. It appears also that the diametral tensile test is not sufficiently discriminating to allow for an in vitro simulation of clinical properties.


Power spectral distribution of the masseter electromyogram from surface electrodes. The power spectral distribution of an electromyogram offers a useful presentation of the myoelectric signal at any level of muscle activity. Various factors which may affect this distribution are considered. A computerized method for obtaining the power spectral distribution for masseter and a study of the effect of bite force and electrode position on this is described.


Cytotoxicity of temporary crown and bridge materials. In vitro cytotoxicity of freshly prepared temporary crown and bridge materials was studied using mouse fibroblasts prelabelled with 3H-thymidine grown in shake flask cultures. Cytotoxicity was measured as (1) lack of cell multiplication, (2) stainability with Trypan blue and (3) release of 3H-labelled material to the culture medium. All the materials tested (zinc oxide-eugenol cement (ZOE), Scutan and Sevriton) were cytotoxic in this system, ZOE most strongly. This finding favours the view that the in vitro cytotoxicity of dental materials should not be used alone as a screening test for their biological compatibility under clinical conditions since clinical experience and previous in vivo findings have established that ZOE is biologically well tolerated by the dental tissues.


The effect of the bite plane splint on the electromyographic silent period duration. An electromyographic study of the masseter and anterior part of the temporalis muscles was performed on ten patients presenting temporomandibular joint dysfunction symptoms. The EMG silent periods (SP) produced in the open-close-clench cycle and jaw-jerk reflex were compared for duration before and after treatment with an occlusal bite splint. Following use of the splint, there was a shortening of SP indicating the possible use of the duration of SP as a diagnostic measurement, and also as an indication of treatment effectiveness.


The fallacy of facial measurements of occlusal height in edentulous subjects. A controlled trial was made using fifteen subjects and making 120 measurements with a caliper gauge between marks disposed on the upper lip and the point of the chin when maxillo-mandibular relationships were altered vertically by known amounts within a range of 6 mm. It was found that mean facial measurements could account for only half of the skeletal movement involved. The variability of soft tissue translation in relation to skeletal movement led to the conclusion that such facial measurements are inappropriate to clinical practice.


The influence of percussion, occlusion and mastication on the occurrence of silent periods in masseter muscle activity. The occurrence of silent periods in masseter muscle activity was investigated during percussion of the bony structures of the head and neck, during occlusion of the teeth on surfaces of varying hardness, and during chewing of different food-stuffs. Silent periods were demonstrated on percussion during isometric and isotonic contraction of the masseter muscles and the occurrence of silent periods was influenced by the force of occlusion and by the nature of the surface contacted. Mandibular velocity was investigated during tapping and chewing sequences by ultra-high-speed cinematography, but it was not found possible to identify a critical change in mandibular velocity associated with the occurrence of silent periods. More silent periods were observed during the chewing of hard foods than of soft foods and there were more silent periods near the beginning of chewing sequences than towards the end. Differences in latency and duration of silent periods were observed in relation to artificial changes in the occlusion.


Metastatic chondrosarcoma to the maxilla: review of the literature and report of case. Metastatic tumors to the jaw are relatively uncommon. When they occur, the primary tumor is most likely to be an adenocarcinoma from the breast, lung, or kidney. Metastatic tumors most frequently involve the mandible rather than the maxilla. The route of metastasis is considered hematogenous, although spread via lymphatic channels or the vertebral venous plexus may occur. An unusual instance of primary chondrosarcoma of the scapula metastasizing to the maxilla and to various soft tissue sites from tumor emboli, probably arising from an extensive metastatic lesion of the left atrium of the heart, has been presented.


Mandibular metastasis from carcinoma of the bladder. A case of metastasis to the jaw from carcinoma of the bladder is reported. Only one other case has been reported in the past 90 years. The case is also unusual in that the symptoms of the jaw were the first indication that metastasis had occurred.


Angiosarcoma of the maxillary sinus: report of case. The third reported case of primary angiosarcoma of the paranasal sinuses is presented. The neoplasm occured in the left maxillary sinus of a 26-year-old white woman. The patient was treated with external irradiation with cobalt of a total dose of 7,000 rads. No evidence of recurrence has been reported.


Ameloblastic fibroma: report of case.

Ameloblastic fibroma: report of case. A 3-year-old girl had a large, painless, radiolucent lesion that involved the right side of the mandible. The lesion extended from the canine region to the condyle and coronoid process. A microscopic diagnosis of ameloblastoma was made by the hospital pathologist. Because it is unusual to find an ameloblastoma in a 3-year-old child and because the extensive surgical procedure that would be necessary to remove an ameloblastoma of this size, further consultation was required. As a result, the lesion was diagnosed as an ameloblastic fibroma and a more conservative surgical procedure was performed. Sixteen months after surgery, radiographic evidence showed complete resolution of the bony surgical defect, with no evidence of recurrence. This case once again points out the necessity for exact diagnosis of similar histologic lesions that may require a different approach in treatment.


Bacterial endocarditis of dental origin: report of case. Although appreciated by most practitioners, the fact that dental infection may be the source of bacteremia without a history of recent dental procedures is occasionally overlooked. The case reported here illustrates what we feel is an example of such a phenomenon. The eradication of the oral foci of infection enhanced the patient's response to therapy and prompted his ultimate recovery.


Simplified approach to clinical photography. These photographic aids are intended to offer an alternative photographic system to the individual who is initially reluctant or unable to invest in the financial commitment of a more sophisticated system. Actual cost of individual components may be ascertained by comparative shopping.


Fiber optic surgical retractor.

Fiber optic surgical retractor. A ramus retractor with a variable high-intensity light source has been designed. It offers access, direct high-intensity visibility, reliability, compactness, and sterilizability. We have used this modification for the past five years. It has allowed direct visibility and identification of structures in the surgical field without the use of cumbersome overhead surgical lights, headlights, or spotlights.