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Biomedical subjects

T Brown

Publications and source records attributed to T Brown.

At least 415 records · Page 23Linked to original sources
PubMed1981

Hypothalamic-adenohypophyseal function in male rhesus monkeys. A primate model.

The secretion of six anterior pituitary hormones in both the basal state and after stimulation or suppression in nine young adults male rhesus monkeys (Macaca mulatta) was studied. Growth hormone (GH), prolactin, thyroid-stimulating hormone (TSH), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) secretion were evaluated. Adrenocorticotropin hormone (ACTH) secretion was studied indirectly by measuring plasma cortisol levels. The tests were performed in combination and in sequence over a 7-hour period. Thus, multiple functions of the hypothalamic-hypophyseal axis can be studied quickly utilizing small quantities of blood.

Animals↗
PubMed1980

Comparison of mesiodistal crown diameters of the deciduous and permanent teeth in Australian aboriginals.

Mesiodistal crown diameters of corresponding deciduous and permanent teeth were compared in 106 male and 66 female Aboriginal subjects from Yuendumu in the Northern Territory of Australia. On average, the size relationships were similar to those reported for Caucasoid groups but there was considerable variation between subjects, particularly in the deciduous first molar--permanent first premolar comparison.

Australia↗
PubMed1980

Correlations between crown diameters of the deciduous and permanent teeth of Australian Aboriginals.

Correlations between crown diameters of corresponding teeth and tooth groups in the deciduous and permanent dentitions are reported for Australian Aboriginals. Size associations for within-dentition comparisons were stronger than those for between-dentition. Furthermore, correlations tended to be greater for corresponding tooth groups than for single teeth both within and between dentitions. This co-ordination appears to be well marked in Aboriginals compared with other populations.

Australia↗
PubMed1980

The effectiveness of a hearing aid delivery system.

One hundred and forty-two adult patients had hearing aid evaluation by a modified Carhart technique. Sixty per cent of patients purchased the recommended aid. Reasons for failure to purchase were established by personal contact and by telephone. They are discussed. Open-ended return appointments are recommended for purchasers because subjects have widely varying problems with hearing aids.

Follow-Up Studies↗
PubMed1979

Family studies of tooth size factors in the permanent dentition.

Correlations between dimensions of the permanent teeth in Australian Aboriginals were studied by factor analysis to disclose the main sources of shared variability. Findings indicated that in both males and females most of the common variability in the tooth dimensions could be accounted for by factors representing mesiodistal size of anterior teeth, buccolingual size of anterior teeth, generalized size of the premolars and generalized size of the molars. Factor scores derived from the analysis were used to calculate intraclass correlations among brothers and among sisters. These correlations tended to be higher for the factors contributing most to the common variability indicating that the factors might represent fields under direct genetic control. There was no trend for intraclass correlations among siblings derived from multivariate scores to be consistently higher than those based on observed tooth dimensions. The main advantage to the user of factor analysis is the ability to interpret associations between interrelated variables more objectively than is possible by conventional correlation methods.

Cuspid↗
PubMed1979

Atypical pseudocysts of the pancreas: an ultrasonographic evaluation.

Ultrasonograms of most pseudocysts have a typical appearance--sharply defined, smooth wall, ovoid, located in the region of the pancreas. However, in reviewing the sonographic appearance of pseudocysts, other ultrasonographic characteristics may occasionally be encountered. Eleven patients with atypical pseudocysts are presented. The demonstration of multiple septations, multiple echoes within a sonolucent mass, and even failure to enhance posteriorly should not exclude the diagnosis of pancreatic pseudocyst in the proper clinical setting. The value of serial scans is also stressed. In this series, it was possible to suggest the diagnosis of infection, hemorrhage, and rupture of pseudocysts by demonstrating cysts with more typical appearances on prior examinations.

Adult↗
PubMed1979

Carpal radiographs in orthodontic treatment.

The pubescent period offers the best opportunity to accomplish the objectives of orthodontic treatment in the shortest time. Treatment during the period of maximum growth activity reduces some of the uncertainties associated with early treatment. Carpal radiographs can be used as a guide to determine the onset of the adolescent growth spurt and hence provide the clinician with a diagnostic and planning aid to optimize treatment efficiency.

Adolescent↗
PubMed1979

Inhibition by amoeba-specific antiserum and by cytochalasin B of the cytopathogenicity of Naegleria fowleri in mouse embryo-cell cultures.

Inhibitors of trophozoite motility and phagocytosis were used to investigate the mechanism of Naegleria fowleri cytopathogenicity in mouse-embryo (ME)-cell cultures. Amoebae that were immobilised and agglutinated by specific antiserum exhibited no cytopathic activity, although they remained alive and were in constant contact with the ME cells. Mammalian-cell damage occurred only when the organisms recovered pseudopodium function and began to migrate over the monolayers as they overcame the inhibitory effects of the antiserum. Cytochalasin B at a concentration of 10 microgram/ml, shown to prevent the engulfment of chick erythrocytes by amoebae, also inhibited the cytopathogenicity of Naegleria when incorporated in ME-cell culture medium. Despite repeated contact with active trophozoites, the ME cells showed only those morphological changes characteristically induced by cytochalasin B itself. The amoebae in turn showed signs of starvation after 3 or 4 days' incubation, suggesting that the feeding activity of trophozoites was suppressed. Colchicine, on the other hand, inhibited neither the ingestion of erythrocytes nor the destruction of ME cells by amoebae. It was concluded that the cytopathogenicity of N. fowleri in ME-cell cultures was due to physical rather than biochemical or cytotoxic mechanisms and was associated with the phagocytic activity of trophozoites.

Amoeba↗