Biomedical subjects
A Harrison
Publications and source records attributed to A Harrison.
A colonic double bubble.
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Partial denture design in general dental practice--10 years on.
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A survey of patients referred to restorative dentistry clinics.
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A failure to find empirical support for Beardslee and Vaillant's prediction about alcoholism.
Recent studies have proposed that the personality pathology in alcoholics is probably a result, not a cause, of alcohol intake. Thus, 19 male alcoholic veterans were assessed to determine whether there was a positive correlation between personality pathology and lifetime amount of absolute alcohol consumed. A multiple regression analysis of the data showed that there was no evidence for a statistically significant positive correlation between the lifetime amount of absolute alcohol consumed and personality pathology. The only statistically significant correlation found was a negative correlation between personality pathology and age, a finding consistent with some other recent studies.
The effect of a series of fixatives on the AgNOR technique.
With increasing interest being shown in nucleolar organizer regions (NORs) in pathology, it was considered of great importance to evaluate the effect of some of the more commonly used and more specialized fixatives on the demonstration of these moieties. NORs can be demonstrated in paraffin sections by a silver technique (AgNOR method) which was developed from a method used by cytogeneticists for the demonstration of NORs in chromosome spreads. The degree of staining is dependent on the fixation regime employed and results may vary greatly from one fixative to another. The fixative schedules and post-treatments used in this study were based on standard sequences from the literature. We have shown that, in general, alcohol-based fixatives give optimal results, Carnoy's fluid being especially recommended. Mercurial and dichromate-containing fixatives were found to have highly detrimental effects on NOR staining. 'Routine' 10 per cent formol saline fixation gave adequate results whereas 10 per cent neutral buffered formalin gave optimal staining, similar to alcohol-based fixation.
Relative concentration of astatine-211 and iodine-125 by human fetal thyroid and carcinoma of the thyroid in nude mice.
The concentrations of 211At and 125I were measured in various tissues in nude mice bearing xenografts of human thyroid tissue (fetal and malignant). The relative concentration of the two halogens was obtained at 4 and 24 h after injection. Samples were taken of the host blood, muscle and thyroid gland and the grafted tissues. The mouse thyroid concentrated 125I more efficiently than 211At but the human grafts concentrated both halogens about equally.
Effect of impact stress on the wear of some restorative materials and enamel.
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The effect of nicotine on the delay of gastric emptying.
The effect of cigarette smoking and its active component, nicotine, on the gastric emptying of solid food was assessed in a randomized double-blind crossover design. Ten regular smokers were studied after a 6 h fast and least 18 h after their last cigarette. Subjects smoked a total of three high (1.91 mg) or low (0.17 mg) nicotine cigarettes, before and after a technetium-labelled solid meal and were scanned by gamma camera periodically over a 2-h period. All calculations of gastric emptying revealed a significant delay after smoking high versus low nicotine cigarettes in: mean per cent isotope remaining in the stomach at each measurement point from 90-120 min; amount of meal remaining in the stomach at 2 h; and mean time at which 50% of the meal had emptied (T1/2). Delay in gastric emptying was significantly correlated with increase in serum nicotine concentration on the high nicotine day.
Spastic cerebral palsy: possible spinal interneuronal contributions.
The author explores the possibility that abnormal and immature spinal interneuronal circuits play a rôle in spastic cerebral palsy. Interneuronal abnormalities could account for a number of characteristic signs: sensitivity to normally innocuous stimuli, hyperreflexia, abnormal and inappropriate co-ordination patterns, and limitations in acquiring, planning, executing and correcting skillful actions. The precise pattern of interneuronal anomalies present will depend on the original site of the lesion, age at onset, and on how central and segmental development were affected. Although the number of relevant studies is very small, there are indications that long-term training can produce changes in segmental response, both by altering descending inhibition and by producing lasting changes in spinal neuronal organisation and responsiveness. Modern recording techniques have introduced the prospect of tracing immature and abnormal segmental components and of establishing their impacts on movement control.
Toxicity of astatine-211 in the mouse.
The toxicity of the alpha particle emitting halogen astatine-211 was examined in male and female mice. Pathological changes were seen in mice killed at 14 days and/or at 56 days following a single injection of 61 kBq211 At per g body weight. The tissues affected, in order of severity were: spleen, lymph nodes, bone marrow, gonads, thyroid, salivary glands and stomach.
Minimal change glomerulonephritis associated with Schistosoma hematobium infection--resolution with praziquantel treatment.
In a patient presenting with hematuria and proteinuria (albuminuria), bladder biopsy demonstrated Schistosoma hematobium infection and renal biopsy showed a minimal change glomerulonephritis. The hematuria and proteinuria resolved following praziquantel therapy. The pathogenesis of glomerulonephritis in association with Schistosoma infection is discussed.
Morphology and immunoelectron microscopy of AIDS virus.
Lymphocytes infected with human T-lymphotropic virus type III/lymphadenopathy-associated virus were examined by thin-section and immunoelectron microscopy, with horseradish peroxidase as an electron-dense marker. There was no evidence of an intracytoplasmic virion precursor, but viral antigen accumulated at the plasma membrane. Particles formed at the plasma membrane, and most virus was found in extracellular spaces. Mature virus had an envelope with fuzzy surface projections surrounding a centric core and an electron-dense eccentric nucleoid.
Handicapped individuals in Kuwait.
A large-scale community screening study is proposed for Kuwait, using a schedule based on the 1980 WHO Classification of Impairments, Disabilities and Handicaps. The needs for accurate prevalence data are reviewed from the standpoints of establishing aetiological patterns, pinpointing opportunities for prevention and furnishing a sound basis for planning in a country with a rapidly growing population and still-developing network of care services. A permanent mechanism for monitoring prevalence trends and service needs is proposed in the form of a Multidisciplinary Handicap Register. Details of these proposals and their feasibility are discussed in the light of previous work.
Influence of abrasive particle size and contact stress on the wear rate of dental restorative materials.
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A double blind comparison of thiothixene and a trifluoperazine/chlorpromazine composite in the treatment of chronic schizophrenia.
Thirty chronic schizophrenic patients participated in a double-blind crossover trial of thiothixene (Navane) and a control drug combination of trifluoperazine and chlorpromazine. No statistically significant difference was found between the two drug conditions on numerous behavioural scales. Experience with thiothixene suggested that it was comparable with control drugs in the activation of withdrawn patients but needs to be used in combination with a more sedative antipsychotic agent in the treatment of some paranoid patients.
A correlation between abrasion resistance and other properties of some acrylic resins used in dentistry.
This investigation studies the relationship of hardness, elastic modulus and scratch width as dependent variables to the abrasion resistance of twenty-three dental acrylic resins. The multiple correlation R, when all three variables are used as predictors, is 0.727. Because of the significant intercorrelations between the variables themselves a stepwise multiple regression analysis showed hardness as a redundant variable. Abrasive wear can be estimated from the following equation Abrasive wear = 806.1 - 0.1498 modulus + 0.681 scratch width (R = 0.725; standard deviation of estimate +/- 50.8) The deletion of scratch width does not appreciably reduce the standard deviation of the estimate: Abrasive wear = 1063.4 - 0.2055 modulus (r = 0.683; standard deviation of estimate +/- 50.3) The method of curing the specimens conformed to the respective manufacturers' instructions. Abrasion and scratch tests were performed using methods developed by the authors and previously described in the literature, whereas the hardness and elastic modulus results were devised from standard test procedures. Further research is currently in progress to improve the predictive power of abrasion resistance with additional new variables.
The specificity of schizophrenic thought disorder.
Bannister and Salmon (1966), in a repertory grid study, reported that 'thought-disordered schizophrenics lost significantly more reliability and social agreement when shifted from object to people construing than normal'. This conclusion is of doubtful validity, since the between-grids variable, people vs. objects, was confounded with at least five other variables of possible relevance, three of which have been found by subsequent workers (McPherson & Buckley, 1970; Williams, 1971; Heather, 1976) to affect performance on grids. The main aim of the present experiment was to determine the effects of as many as possible of these variables. The subsidiary aim was to replicate, or otherwise, the findings of Frith & Lillie (1972) and Haynes & Phillips (1973) that the effective discriminator between thought-disorder schizophrenics and other groups on repertory grid tests is not intensity of relationship between constructs but pure (element or internal) consistency. Six grids involving all feasible combinations of rating familiar and unfamiliar people and objects on psychological and physical constructs were administered to 10 thought-disordered schizophrenics, 10 non-thought-disordered schizophrenics and 10 normals. As regards the main aim of the experiment it was found that there was no significant grids x diagnoses interaction on pure consistency, but that there was one on intensity, even with pure consistency partialled out. Taking previous work into consideration, it appears that this effect is weak, inconsistent from experiment to experiment, and anomalous in the present study. As regards the subsidiary aim, the findings of the two previous experiments cited above were confirmed. The discrepant results of McPherson et al. (1973) are considered, and it is noted that they held only for a subsample of the schizophrenic group in that experiment, the results for the total sample of schizophrenics, manics and depressives not being inconsistent with those of other experiments. The theoretical and practical implications of these and previous finding are indicated.