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Biomedical subjects

G D Miller

Publications and source records attributed to G D Miller.

At least 19 recordsLinked to original sources
PubMed1991

Exercise decreases fat selection in female rats during weight cycling.

Weight cycling (weight loss and regain) increases fat intake in rats allowed to self-select a diet from protein, carbohydrate, and fat sources. This study reports the effects of exercise on macronutrient self-selection. Female Sprague-Dawley rats (5 mo old) self-selected their diet. After 3 wk, rats were assigned to one of the following three groups: ad libitum fed sedentary (Con), sedentary food restricted to 40% Con intake (R-Sed), or treadmill exercised (20 m/min, 1 h/day, 6 day/wk) food restricted to 40% Con intake (R-Ex). Food restriction was for 3 wk followed by 5 wk of refeeding. This was repeated for a second cycle. During restriction, body weight decreased by 30% in R-Sed and by 33% in R-Ex than in R-Sed, fat regain was greater in R-Sed. By week 3 of refeeding, total caloric consumption did not differ. However, fat selection increased in R-Sed (56% kcal) vs. R-Ex (30%) and Con (35%). Fat selection in R-Sed increased further during cycle 2 (73% kcal). Resting oxygen consumption decreased during food restriction in R-Sed and R-Ex. After refeeding, resting metabolic rate in R-Ex was significantly greater than in R-Sed. In conclusion, weight cycling increases dietary fat selection and adiposity. Exercise mitigates this effect.

Adipose Tissue↗
PubMed1990

Interactions between lead and essential elements: a review.

Young children are especially susceptible to the toxic effects of lead. Although the effects of overt lead intoxication have been well studied, critical information on the long-term effects of low level lead exposure is lacking. The results of recent clinical studies indicate that "chronic" low level lead exposure during development can result in behavioral alterations in the absence of overt neurotoxicity. The perturbation of central nervous system functioning may be the result of essential mineral deficiencies resulting from lead-induced impairment of mineral availability and/or an increased sensitivity to lead in the absence of adequate levels of essential minerals. This article reviews research undertaken to examine the interactions between calcium, iron, zinc, copper and lead with reference to how this may impact central nervous system functioning.

Animals↗
PubMed1989

Noncognitive criteria for assessing students in North American medical schools.

In 1986 the authors mailed a one-page questionnaire to 135 North American medical schools requesting information about written expectations for students that contain noncognitive criteria. Eighty-eight questionnaires (65.2%) were returned, and 48 schools (54.5%) indicated they possessed written noncognitive criteria. Those schools having noncognitive criteria were asked to submit the criteria for review and were questioned about their reasons for establishing such criteria. Those schools not having noncognitive criteria were asked whether they perceived a need for such criteria and had plans for developing them. The study showed an increasing trend to create criteria that assist in administrative actions when problems arise. In the 31 sets of noncognitive criteria submitted for the study, the rank order of specific expectations was, from most to least frequently mentioned: honesty, professional behavior, dedication to learning, appearance, respect for law, respect for others, confidentiality, aid to others, substance abuse, and financial responsibility. The authors make recommendations for schools wishing to create noncognitive criteria and explain why they feel such criteria should receive the recognition and importance given to cognitive criteria.

Attitude↗
PubMed1988

DSP-4 treatment produces abnormal tyrosine hydroxylase immunoreactive fibers in rat hippocampus.

DSP-4 has been used as selective toxin for central norepinephrine (NE) systems. The depletion of NE by DSP-4 is though to result from neurotoxic destruction of locus coeruleus terminals and axons. We have used tyrosine hydroxylase immunocytochemistry (TH-IR), silver stains for neural degeneration, and electron microscopy to examine the morphological effects of DSP-4 treatment on the rat hippocampus. Animals survived for either 2 or 5 weeks after DSP-4 treatment. DSP-4 depleted hippocampal norepinephrine levels to 15% of control values. Abnormally enlarged TH-IR fibers were found in the hippocampus of DSP-4-treated animals. No evidence of fiber degeneration was found following light or electron microscopic examination of the dentate hilus in DSP-4-treated animals. These data suggest that DSP-4 treatment does not destroy NE terminals, but may produce an intraneuronal lesion leading to an accumulation of TH and a depletion of norepinephrine within the terminal fields.

Animals↗
PubMed1986

Changes in the noradrenergic innervation of the area dentata after axotomy of coeruleohippocampal projections or unilateral lesion of the locus coeruleus.

Lesions of the septal region result in a significant decrease in the norepinephrine content of the area dentata. Over a period of one year, norepinephrine levels return to normal, presumably due to the proliferation of remaining locus coeruleus fibers. Unilateral lesions of the locus coeruleus produce reductions in [3H]norepinephrine uptake values of about 70% and 30% in the ipsilateral and contralateral area dentata, respectively. By 12 weeks after lesion, the noradrenergic fiber density in the contralateral area dentata is within the range of control measurements, whereas the area dentata ipsilateral to the lesion remains significantly depleted of noradrenergic fibers. At 26 weeks postlesion, no further change was observed in the noradrenergic fiber density of either area dentata. These results are interpreted in light of the hypothesis that locus coeruleus axon proliferation is induced by axotomy and represents the expansion of intact collaterals of damaged fibers.

Animals↗
PubMed1986

National survey of writers of dean's letters for residency applications.

The purpose of the study reported here was to provide descriptive information about dean's letters, which are comprehensive summary letters sent near the end of students' undergraduate medical training by medical school deans to be part of the students' residency applications. Deans of student affairs at 124 U.S. medical schools were surveyed regarding composition of these letters at their institution. They were asked to describe themselves and the letters they write. Responses were received from 87 percent of these schools and provided data on types of information included in the letters, the decision to edit evaluations, student participation in the letter-writing process, use of final summary statements, cost and length of letters, and attitudes toward the development of national letter-writing guidelines. Major findings of the survey show that 97 percent of the writers allocated more space for clinical evaluations than basic science evaluations. Less than 50 percent of the writers included the student's class rank. Almost all included narrative evaluations of the student's performance during the clinical years. Negative information on students was addressed inconsistently by the writers. Eighty-five percent of the writers categorized their students in final summary statements, but many of these failed to provide descriptions of the categories used or explanatory data. The present authors make recommendations for writing more credible and useful letters.

Educational Measurement↗
PubMed1985

Internal escape channel to improve the seating of full crowns with various marginal configurations: a follow-up study.

The effectiveness of an internal escape channel in improving the marginal adaptation of full crowns with various marginal configuration was investigated. Full crowns with 90-degree shoulders had a vertical discrepancy comparable to those of crowns with accentuated finish lines. Although an internal escape channel significantly improved the seating of a full crown with a 90-degree shoulder and 45-degree level, its vertical discrepancy was much higher than those of crowns with an accentuated finish line or a 90-degree shoulder.

Cementation↗
PubMed1979

Biogeometric guide to groove placement on three-quarter crown preparations.

An attempt has been made to establish a practical guide to placing the grooves on a three-quarter crown which fulfills biologic, mechanical, and structural requirements. It is our intention to refine and adjust groove placement to biologic and practical limitations in the hopes of ending some of the confusion and difficulty in partial veneer preparations.

Crowns↗
PubMed1975

The free vascularized bone graft. A clinical extension of microvascular techniques.

For the common problem of lower limb injury with extensive. Loss of skin and bone, a new method of free vascularized bone grafting has been used and integrated with an appropriate soft tissue flap repair. The technique was developed to salvage two legs which would otherwise have been amputated. The preliminary result in Case 2 is encouraging. This case would appear to be the first successful distant transfer of a composite fibular graft by microvascular anastomoses to be reported in man.

Accidents, Traffic↗