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Biomedical subjects

J E Foster

Publications and source records attributed to J E Foster.

33 records · Page 2Linked to original sources
PubMed1993

Surgical management of hyperparathyroidism at an Air Force medical center.

A critical determinant of successful neck exploration for primary hyperparathyroidism (HPT) is the experience of the surgeon. Results of 17 patients treated surgically for HPT were reviewed to compare results at our medical center with results of large series reported from established national centers. Preoperative laboratory evaluation of 15 patients with surgically proven HPT (solitary adenoma, 14; diffuse hyperplasia, 1) included: mean serum calcium (Ca) 10.9 mg/dl +/- 0.79 and mean serum chloride/phosphate ratio 39 mg/dl +/- 7.9. Serum parathyroid hormone (PTH) was elevated in all patients. Seven neck ultrasounds were performed with a positive predictive value of 42%. No significant operative complications occurred. Mean postoperative serum Ca was 8.34 mg/dl +/- 0.75. One patient had asymptomatic hypocalcemia (Ca = 6.5 mg/dl). Follow-up in 11 patients (65%) at a mean of 8.6 months revealed no evidence of recurrence in these patients. In our experience, proper patient selection and careful surgical technique within established principles for neck exploration and parathyroidectomy lead to excellent results despite the size of the medical center. Patient selection is based on serum Ca, PTH, and chloride/phosphate ratio. Preoperative imaging studies did not appear to be of benefit in the small study reported here.

Adult↗
PubMed1992

An investigation of the acute effect of gentamicin on the renal handling of electrolytes in the rat.

Standard renal clearance techniques were used to investigate the acute effects of gentamicin on renal electrolyte handling in anesthetized rats. Data were obtained before substantial changes in tubular integrity would be expected to occur, thus permitting a distinction between the actions of the drug per se and renal changes resulting from underlying tubular damage. Infusion of gentamicin over a 3-hr period resulted in an immediate and sustained calciuresis and magnesiuresis, with no significant change in the renal clearance of sodium or potassium. Within 60 min of the onset of drug infusion at 0.28 mg/kg/min, renal calcium clearance (ml/min) increased from 0.095 +/- 0.013 to 0.210 +/- 0.016 (P less than .001) and renal magnesium clearance (ml/min) increased from 0.538 +/- 0.059 to 0.662 +/- 0.053 (P less than .01). Because it was subsequently shown that infusion of gentamicin did not alter glomerular filtration rate, it is clear that both responses resulted from a reduced tubular reabsorption of the respective ions; they were rapidly reversible when gentamicin infusion ceased. A higher dose of gentamicin (0.56 mg/kg/min for 3 hr) also significantly decreased plasma magnesium concentrations (0.40 +/- 0.01 vs. 0.49 +/- 0.02 mmol/l, treated vs. control; P less than .01). Gentamicin-induced changes in the renal handling of calcium and magnesium, therefore, occur independently of and before the development of nephrotoxicity. They may be at least partially responsible for the alteration in electrolyte homeostasis seen in humans during aminoglycoside treatment (e.g., hypomagnesemia). It is interesting to speculate on the possibility that they may also in some way contribute to the subsequent cellular injury that is known to occur with prolonged use of gentamicin.

Animals↗
PubMed1987

Rotational artifact in phase imaging of cardiac scans: potential pitfalls in diagnosis.

In the past few years, we have occasionally observed linear bands in the phase images of gated cardiac blood-pool scans along the interventricular septum region among patients with normal septal motions. Our retrospective study investigated the cause of out-of-phase bands of 12 patients. We documented through review of cines, computer analysis of gated cardiac blood-pool scintigraphy data, and correlation with echocardiograms that this phenomenon was artifact introduced by rotational movements of the heart. It is important for nuclear physicians to recognize this rotational artifact on the phase analysis image in order to avoid the erroneous misdiagnosis of wall motion abnormalities of the septum.

Adult↗
PubMed1985

A technique for long term continent gastrostomy.

The use of the continent gastrostomy described herein offers several advantages: 1, the elimination of an indwelling catheter; 2, prevention of soiling at skin level; 3, long term access to the normal gastrointestinal track for alimentation without fear of tube erosion; 4, little compromise to gastric volume, and 5, ease of stoma care. We recommend this operation in instances when long term tube feedings are indicated either because of damage to the central nervous system or as a palliative treatment for patients with higher obstructing gastrointestinal malignant disease. The procedure may also be useful for patients in whom esophagogastric continuity has been interrupted (surgically or traumatically) and in whom reconstruction of the gastrointestinal tract would not seem feasible within a three to six month interval.

Catheters, Indwelling↗
PubMed1984

Central hemodynamics during progressive upper- and lower-body exercise and recovery.

The purpose of this study was to compare stroke volume (SV) and myocardial contractility responses during and immediately after upper- and lower-body exercise. Nine men (mean 28 yr, 78 kg) completed progressive intensity discontinuous tests on both an arm crank and cycle ergometer. Exercise for each power output (PO) was 7 min with 20-min rest periods interspersed. Impedance cardiography was used to measure cardiac output (Q), SV, and contractility on a beat-by-beat basis during exercise and a 15-s recovery period. Q increased linearly, and total peripheral resistance decreased exponentially with increasing PO levels. During recovery from exercise, the Q and heart rate (HR) values decreased immediately at all PO levels. When the exercise VO2 exceeded 1.0 1 X min-1, SV fell significantly during recovery for both exercise modes. In general, the recovery myocardial contractility indices remained similar to exercise values. It was concluded that immediately after low intensities of exercise, Q decreases because of a fall in HR. After moderate- and high-intensity exercise, Q decreases because of a fall in both HR and SV.

Adult↗
PubMed1984

Evaluation of various nutritional supplements in the prevention of stress-induced gastric ulcers in the rat.

We studied the effectiveness of various nutritional supplements in preventing stress-induced gastric ulcers in rats. Male rats were restrained on a board, divided into nine groups and orogastrically infused with one of four commercial nutritional supplements--25 per cent glucose solution, normal saline solution or antacids. The other groups received either cimetidine or no treatment. The rats, in this study, were sacrificed at the end of four hours, and all ulcers were counted. Any solution providing calories, including 25 per cent glucose solution, afforded significant protection against ulceration. While the antacids were better than no treatment, they were significantly worse than any nutritional supplement. It appears to be that luminal substrates markedly increase the ability of the gastric mucosa of the rat to resist ulceration.

Animals↗
PubMedDate not supplied

Black-white inequalities in mortality and life expectancy, 1933-1999: implications for healthy people 2010.

OBJECTIVES: Optimistic predictions for the Healthy People 2010 goals of eliminating racial/ethnic disparities in health have been made based on absolute improvements in life expectancy and mortality. This study sought to determine whether there is evidence of relative improvement (a more valid measure of inequality) in life expectancy and mortality, and whether such improvement, if demonstrated, predicts future success in eliminating disparities. METHODS: Historical data from the National Center for Health Statistics and the Census Bureau were used to predict future trends in relative mortality and life expectancy, employing an Autoregressive Integrated Moving Average (ARIMA) model. Excess mortality and time lags in mortality and life expectancy for blacks relative to whites were also estimated. RESULTS: Based on data for 1945 to 1999, forecasts for relative black:white age-adjusted, all-cause mortality and white:black life expectancy at birth showed trends toward increasing disparities. From 1979, when the Healthy People initiative began, to 1998, the black:white ratio of age-adjusted, gender-specific mortality increased for all but one of nine causes of death that accounted for 83.4% of all US mortality in 1998. From 1980 to 1998, average numbers of excess deaths per day among American blacks relative to whites increased by 20%. American blacks experienced 4.3 to 4.5 million premature deaths relative to whites in 1940-1999. CONCLUSIONS: The rationale that underlies the optimistic Healthy People 2010 forecasts, that future success can be built on a foundation of past success, is not supported when relative measures of inequality are used. There has been no sustained decrease in black-white inequalities in age-adjusted mortality or life expectancy at birth at the national level since 1945. Without fundamental changes, most probably related to the ways medical and public health practitioners are trained, evaluated, and compensated for prevention-related activities, as well as further research on translating the findings of prevention studies into clinical practice, it is likely that simply reducing disparities in access to care and/or medical treatment will be insufficient. Millions of premature deaths will continue to occur among African Americans.

Adolescent↗