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Biomedical subjects

T Brown

Publications and source records attributed to T Brown.

At least 397 records · Page 22Linked to original sources
PubMed1982

Craniocervical morphology and posture in Australian aboriginals.

The length of the spinal column as a percentage of stature is smaller in the Australian aboriginal than in most other ethnic groups (Abbie, 1957). It is conceivable that relative lengths of the cervical column might influence population differences in craniocervical posture and craniofacial morphology. The present study aimed to elucidate this relationship by comparing head posture and craniofacial morphology in Australian aboriginals to the same features in a previously studied sample of 120 Danish students (Solow and Tallgren, 1976). The aboriginal sample consisted of 42 young male adults from the Yuendumu settlement, Northern Territory, Australia. Cephalometric films of the natural head position were taken during a field trip to the settlement. The comparison comprised 18 postural and 61 morphological variables. In the aboriginals, the cervical column was shorter and had a less pronounced lordosis. The head was held about 3 degrees lower, and the upper cervical column was 8 1/2 degrees more forward inclined. As a consequence, the craniocervical angle was about 6 degrees larger. Comparison of the craniofacial morphology in the two groups showed in the aboriginals a shorter upper facial height, a larger anterior lower facial height, and a larger vertical jaw relationship (NL/ML). The length of the posterior cranial base, s-ba, was 4 mm shorter (P less than 0.001) in the aboriginals, possibly developmentally related to the generally shorter spinal column in Australian aboriginals.

Adult↗
PubMed1982

Influence of long-term infusions on lidocaine kinetics.

Lidocaine kinetics were examined during continuous infusions in five healthy subjects using stable isotope lidocaine labeled with two deuterium atoms. During phase 1, lidocaine and stable isotope lidocaine (50 mg IV each) were given as a bolus to confirm that the two species were kinetically identical. Phase 2 consisted of a long-term (30 hr) lidocaine infusion designed to produce a steady-state concentration equal to 1.5 microgram/ml. Twenty-four hours into the infusion, stable isotope lidocaine (50 mg) was given as an intravenous bolus and kinetic parameters were calculated. Phase 3 differed from phase 2 in that target steady-state lidocaine concentration was 4 microgram/ml and the stable isotope lidocaine dose was reduced to 40 mg. A gas chromatograph-mass spectrometer was used to determine lidocaine and stable isotope lidocaine serum concentrations. Compared to phase 1, clearance decreased (P less than 0.05) and half-life increased (P less than 0.025) during phases 2 and 3. The volume of distribution at steady-state remained constant during all three phases. Lidocaine cumulated in serum during long-term infusions in all five patients; repeated decreases in infusion rate were necessary to avoid exceeding desired target concentrations in phases 2 and 3.

Adult↗
PubMed1982

Pharmacologic effects of melatonin on hypothalamic-adenohypophyseal function in the nonhuman primate.

The pharmacologic effects of intravenous melatonin on hypothalamic-adenohypophyseal function were studied in male rhesus monkeys (n = 10) and compared to control animals (n = 9-13). Basal and arginine- or L-dopa-stimulated values of growth hormone in melatonin-treated animals were similar to those of control primates. Insulin-stimulated growth hormone secretion was slightly decreased. Melatonin did not affect basal or thyroid stimulating hormone releasing hormone (TRH)-stimulated values of thyroid stimulating hormone (TSH) or prolactin. No effects were seen on basal and gonadotropin releasing hormone (GnRH)-stimulated luteinizing hormone (LH) or follicle stimulating hormone (FSH) secretion.

Animals↗
PubMed1982

Effects of cranial radiation on hypothalamic-adenohypophyseal function: abnormal growth hormone secretory dynamics.

The function of the hypothalamic-adenohypophyseal unit was tested in 2 groups of rhesus monkeys before and at periodic intervals after the administration of 2400 and 4000 rads cranial radiation. This therapy was given in 10 fractions over a 2-week period. Plasma TSH, basally and after TRH administration, and LH and FSH, before and after gonadotropin-releasing hormone stimulation, were normal up to 1 yr after radiation. Plasma GH at the basal state and after arginine and L-dopa stimulation was also normal. An insulin tolerance test, however, demonstrated a blunted GH response at a dose (0.1 U/kg) that caused brisk stimulation of GH secretion in normal control monkeys. A larger dose of insulin (0.2 U/kg) resulted in ample secretion of GH in these animals, suggesting decreased hypothalamic sensitivity to insulin in treated animals. The measurement of GH every 20 min for 24 h in animals treated with 4000 rads showed a dramatically altered secretory pattern of GH 1 yr after radiation. GH secretory spikes were markedly decreased in both frequency and amplitude, suggesting a reduction in the normal daily production of GH.

Animals↗
PubMed1982

16 PF correlates of perceptual reactance.

College students (n = 24 males, 36 females) volunteered to take the kinesthetic figural aftereffect task and the 16 PF in a survey of state versus trait personality correlates of perceptual reactance. A reliable emergence of the trait component of perceptual reactance over trials was noted. Perceptual reducers were outgoing, affected by feelings, happy-go-lucky, practical, and undisciplined, while augmenters were reserved, stable, sober, imaginative, and controlled. Findings tend to support the trait model of perceptual reactance, with interference from a state component.

Female↗
PubMed1982

Typhoid fever.

Explore the source record for details and available documents.

Amoxicillin↗
PubMed1981

Radiotherapy in nonlentiginous melanoma of the head and neck.

Thirty-seven patients with superficial spreading or nodular melanoma of the head and neck treated with irradiation are reviewed. Twenty-one patients were referred within three months of surgery. Six had an incisional biopsy followed by postoperative irradiation, 4 were locally controlled (1 dying of metastatic melanoma, 2 dying of intercurrent disease and 1 is alive and well), and 2 were not (both dead of melanoma). Fifteen patients had a local excisional biopsy (11 having tumor to the limits of the excision) followed by postoperative irradiation. Fourteen of the 15 had local control (3 had lymph node metastases and died, 3 died of distant metastases from melanoma, 7 are alive and well from 1-14 years following treatment, and one is dead of intercurrent disease), and 1 had a local recurrence and subsequently died of metastatic melanoma. Sixteen patients were irradiated for local and/or regionally recurrent disease following unsuccessful surgery, and only two were successfully controlled by irradiation and are alive and well at four and five years, respectively. Local control was 70% when a dose per fraction of greater than 400 rads was used, compared with 25% when a dose per fraction of less than 400 rads was used. It is concluded that nonlentiginous melanoma of the head and neck is not a radioresistant tumor and that local excision followed by high dose per fraction radiotherapy deserves further study in the management of melanomas of the head and neck.

Adult↗
PubMed1981

Tooth size and morphology in a recent Australian aboriginal population from Broadbeach, South East Queensland.

Odontometric and morphologic observations were made of the dentition of skeletal remains of australian aborigines from Broadbeach, S.E. Queensland. Tooth size, especially of the molars, was found to be significantly larger than that reported for other recent Aboriginal populations. Tooth morphology also differed, with a higher frequency of five cusped second molars, and a lower frequency of shoveling and Carabelli's cusp than previously reported as typical of Australian aborigines.

Australia↗
PubMed1981

Dental attrition and degenerative arthritis of the temporomandibular joint.

The extent and rate of occlusal attrition in relation to degenerative arthritis of the temporomandibular joint were studied in 101 skulls representing early Aboriginal man in Australia. Joint degenerations affected 40% of the specimens and were associated with both the rate and extent of tooth attrition. Age, unaccompanied by tooth wear, was not significant in the progress of the disease. Degenerations affected the temporal joint surface more frequently than the condyle, particularly in the lateral and central regions of the articular eminence. Patterns of degenerative joint disease in the Aboriginals illustrated a break-down in the physiological adaptability of the masticatory system resulting from increased occlusal stress consequent upon progressive tooth wear. Under these conditions, the teeth and the temporomandibular joints enter a 'wear-out' phase of occlusal function which usually commences in early adult life and becomes more severe as the conditions continue.

Adolescent↗