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Biomedical subjects

B A Warner

Publications and source records attributed to B A Warner.

17 recordsLinked to original sources
PubMed1996

Biochemical effects of oral sodium phosphate.

Our objective was to monitor serum and urine biochemical changes after oral sodium phosphate cleansing in a prospectively designed study. The study subjects were seven healthy, asymptomatic adults. Sodium phosphate 45 ml diluted in 45 ml water was given orally at baseline and 12 hr later. Calcium, ionized calcium, phosphorus, sodium, potassium, creatinine, and PTH were analyzed at 2, 4, 6, 9, 12, 14, 16, 18, 21 and 24 hr after the first challenge. Urinary calcium, phosphorus, sodium, potassium, and cyclic AMP were analyzed at baseline and every 2 hr after oral sodium phosphate. Blood pressure, pulse, and respiratory rate were recorded every 2 hr and symptom questionnaires using visual analog scales were completed. A marked rise in phosphorus (peak range 3.6-12.4 mg/dl, P < 0.001) and falls in calcium (P < 0.001) and ionized calcium (P < 0.001) were seen. Rises seen in PTH and urinary cAMP confirmed the physiologic significance of the biochemical effect. There were no significant changes in other serum and urine laboratory or clinical assessments. Reported significant symptoms included bloating, cramps, abdominal pain, and nausea. Significant hypocalcemia and hyperphosphatemia after oral sodium phosphate raises concern about its use in normal individuals. Oral sodium phosphate should not be administered in patients with cardiopulmonary, renal, or hepatic disease.

Abdominal Pain↗
PubMed1996

No continuous relationship between Veterans Affairs hospital coronary artery bypass grafting surgical volume and operative mortality.

BACKGROUND: The purpose of this study was to determine whether risk-adjusted coronary artery bypass grafting mortality rates are significantly related to coronary artery bypass grafting surgical procedure volume within the Department of Veterans Affairs hospital system. METHODS: From April 1987 to September 1992, expected mortality rates were calculated for 23,986 coronary artery bypass grafting procedures performed at 44 different Veterans Affairs hospitals. RESULTS: This study found a statistically significant relationship between annual hospital coronary artery bypass grafting volume and observed mortality rates (p < 0.02). However, no statistically significant relationship between coronary artery bypass grafting volume and risk-adjusted operative mortality was found (p = 0.10). Using analysis of variance on hospital-level data, hospitals with 100 or less cases per year have higher observed to expected mortality ratios than hospitals performing more than 100 cases per year (p = 0.03). Using Poisson regression models, however, a volume threshold could not be found. CONCLUSIONS: These findings are consistent with the current Veterans Affairs policy requirements to periodically review quality at low-volume hospitals.

Analysis of Variance↗
PubMed1993

Effects of chronic glipizide treatment on the NIDD heart.

Extrapancreatic activity of the sulfonylurea, glipizide, was evaluated in the neonatal streptozotocin-induced rat model of noninsulin-dependent diabetes. Two day old Wistar rats were given a bolus of streptozotocin (90 mg/kg i.p.) to cause noninsulin-dependent diabetes; these animals became severely glucose intolerant and eventually developed a cardiomyopathy characterized by reduced heart rate, contractility and cardiac output. Male littermates injected with citrate buffer served as nondiabetic controls. At four weeks of age, the nondiabetic and NIDD rats were administered by gavage either glipizide (2.5 mg/kg) or the methyl cellulose vehicle. Throughout the treatment protocol, no difference in the degree of glucose intolerance was observed between the glipizide-treated and vehicle-treated animals. Glipizide therapy also was ineffective in improving plasma insulin levels, which were significantly depressed in the diabetic group. Yet, animals treated with glipizide for one year exhibited improved myocardial contractile function relative to the vehicle-fed or ad lib fed diabetic animals. Heart rate was significantly elevated and there was a tendency for both the rate of relaxation and contractility to be elevated in sulfonylurea-treated group. Glipizide also reduced the degree of insulin resistance in the heart. Since these changes occur in the absence of changes in glucose tolerance or insulin levels, the heart appears to be very sensitive to the direct effects of the sulfonylureas.

Animals↗
PubMed1993

Cushing's disease with a unilateral adrenal macronodule: evolutive transition or incidental finding?

Cases of coexisting Cushing's disease and unilateral adrenal tumor are rare, and there are conflicting reports in the literature regarding both the pathophysiology and the incidence. We have reported the case of a patient with a biochemically inactive incidental adrenal mass in whom pituitary-dependent Cushing's syndrome developed during follow-up. Authors of past reports have suggested that transitional change is responsible for the adrenal disease. A complete review of the literature has shown that cases of coexisting pituitary Cushing's disease and unilateral adrenal tumor, although rare, are more common than was previously believed. After studying a case in which the adrenal mass was present before disease developed, we suggest that the coexistence may be incidental in some cases.

17-Hydroxycorticosteroids↗
PubMed1991

A field evaluation of the Coulter STKS.

The performance of the Coulter STKS (Coulter, Hialeah, FL) was evaluated in a busy computerized teaching hospital laboratory. The STKS was compared with a Coulter S Plus IV and manually performed 400 white blood-cell differentials. The measured blood-count parameters (i.e., white blood cells [WBCs], red blood cells [RBCs], hemoglobulin [Hb], mean corpuscular volume [MCV], and platelets [PLTs]), compared very well between the two aperture impedance-based systems; precision, linearity, and lack of carryover were excellent. The STKS WBC differential (DIFF), derived from a combination of aperture impedance, aperture conductance, and laser light scatter, also was precise; linear and carryover were insignificant. The DIFFs (n = 424) compared well to the manual WBC differentials, with r values of 0.97, 0.97, 0.73, and 0.86 for neutrophils, lymphocytes, monocytes, and eosinophils, respectively. The DIFF and Suspect Flagging system produced 6.2% false negatives and 2.6% false positives when compared with the manual technique. These were further investigated and discussed. STKS DIFFs were stable for 18 to 24 hours in normal samples anticoagulated with K2EDTA and stored at 20 degrees C prior to analysis. Storage in the same anticoagulant at 4 degrees C and immediate aspiration preserved the DIFF analysis for considerably longer than 24 hours. These performance characteristics make the STKS a significant advancement in automated hematology.

Autoanalysis↗
PubMed1990

Automated haematology analysers: a four-way comparison.

Four automated haematology analysers--the Coulter S + IV, Coulter STKS, Sysmex NE8000, and Technicon H1--were evaluated for operational and quantitative differences. The measured blood count parameters (red cell, white cell and platelet counts, mean cell volume [MCV], haematocrit and haemoglobin) all compared well with the S + IV, although the MCV showed the greatest variation. Of the white cell differential parameters, neutrophils, lymphocytes and eosinophils correlated well with manually performed 400 cell differential counts. Mononuclear cell and monocyte counts generated by the S + IV and NE8000 (respectively) compared poorly with the manual method. The STKS, NE8000 and H1 gave an acceptable five cell population differential from samples stored in K2EDTA for up to 18 h, although the monocyte count from the NE8000 showed considerable variation during that period. All instruments were shown to operate efficiently in either primary or secondary operating mode, but the STKS and NE8000 were considerably faster than the H1, and easier to use in the automated mode.

Blood Cell Count↗
PubMed1985

46,XY gonadal dysgenesis: is oncogenesis related to H-Y phenotype or breast development?

Among women with 46,XY gonadal dysgenesis, there is a high incidence of gonadal tumors. Because of evidence of a connection between occurrence of those tumors, H-Y phenotype, and breast development, we surveyed 55 cases of 46,XY gonadal dysgenesis and 12 related cases involving chromosomal and/or skeletal abnormalities. Our survey, including three new cases presented here, indicates that H-Y phenotype but not breast development may be related to the development of the gonadoblastoma-dysgerminoma. Thus among women with 46,XY gonadal dysgenesis, there are H-Y- and H-Y+ classes, but gonadal tumors are found almost exclusively in the H-Y+ class. Yet one of our patients may represent an exception to the association of H-Y+ phenotype and gonadal tumors in this syndrome.

Adolescent↗
PubMed1985

Effects of aging and illness on the pituitary testicular axis in men: qualitative as well as quantitative changes in luteinizing hormone.

Decreased testicular function occurs as a concomitant of aging in men and is accentuated by the presence of systemic illness. Previous studies identified an intrinsic Leydig cell defect, as reflected by high LH to testosterone ratios and impaired hCG responsiveness in older men. This study questioned whether a qualitative change in LH secretion, as reflected by secretion of LH with an altered ratio of biological to immunological LH (B/I) activity, might occur during aging. To examine this possibility, we measured the levels of plasma LH by RIA and rat interstitial cell testosterone bioassay in 67 men, ranging from 20-80 yr of age. Mean LH levels measured by immunoassay were similar in healthy men older than 40 yr [11.4 +/- 1.0 (+/- SE) mIU/ml; n = 22] and those younger than 40 yr (9.4 +/- 0.6; n = 18; P less than 0.01). Mean bioactive LH levels were also similar (30.0 +/- 4.8 vs. 36.7 +/- 3.3). LH B/I ratios, however, were significantly lower in older men (2.52 +/- 0.33) compared to those in younger (4.10 +/- 0.34; P less than 0.01) men. Regression analysis confirmed the expected inverse relationship of B/I ratio with age (r = -0.47; P less than 0.01) and plasma testosterone with age (r = -0.35; P less than 0.05). Systemic illness independently lowered B/I LH ratios. Systemically ill men over 40 yr of age had lower ratios (1.05 +/- 0.08; n = 27) than age-matched healthy men (2.52 +/- 0.33; n = 22; P less than 0.01). The significant changes in B/I ratio among subgroups reflected modest changes in LH immunoactivity and larger alterations in LH bioactivity in certain subgroups. These findings indicate that the qualitative nature of LH secreted by the pituitary, as reflected by altered LH B/I ratios, may vary as a function of aging and illness in men.

Adult↗
PubMed1982

Responsiveness of gonadotropin secretion to infusion of an opiate-receptor antagonist in hypogonadotropic individuals.

We tested the hypothesis that suppressive effects of endogenous opiate substances are involved in certain hypogonadotropic states. For this purpose, we studied gonadotropin secretion in idiopathic hypopituitarism (five children), constitutionally delayed adolescence (five boys), and Kallmann's syndrome (three men). Endogenous opiate pathways were antagonized by the iv infusion of naloxone hydrochloride at a dose previously shown to elicit a prompt and significant increase in serum levels of LH in normal men. Under these conditions, naloxone did not increase serially sampled serum concentrations or mean urinary levels of LH: or FSH in eight patients with idiopathic hypopituitarism or Kallmann's syndrome. Gonadotropin concentrations in four of five patients with constitutional delay of adolescence also were unaffected. In one boy with clinical and biochemical indices of late pubertal development, naloxone elicited a significant increase in LH levels in blood and urine, similar to the pattern observed in normal men. In contrast to results in experimental animals, naloxone did not suppress serum PRL concentration significantly in any subject. These observations suggest that: 1) endogenous opiate mechanisms are unlikely to constitute a principal factor in maintaining hypogonadotropism in idiopathic hypopituitarism, delayed adolescence, or Kallmann's syndrome, at least acutely; 2) endogenous opiate mechanisms also cannot be implicated in the acute regulation or PRL secretion in children; and 3) the capability of adult men, but not early pubertal boys, to respond with increased gonadotropin secretion during inhibition of opiate receptors suggests that maturation of the opiate-related neuroendocrine system occurs during the course of sexual development in the human.

Adolescent↗