Search PubMed⌕ Search

Biomedical subjects

S Shaw

Publications and source records attributed to S Shaw.

At least 361 records · Page 20Linked to original sources
PubMed1986

Cardiovascular, endocrine and renal effects of atrial natriuretic peptide in essential hypertension.

Plasma concentrations of human atrial natriuretic peptide (hANP) and effects of synthetic alpha-hANP on blood pressure (BP), on endocrine and metabolic variables, and on renal function were investigated in 10 patients with essential hypertension. Alpha-human atrial natriuretic peptide was given intravenously as a 50-micrograms bolus followed by a 45-min infusion at 0.1 microgram/kg per min. The following effects were observed: (1) a marked rise in plasma alpha-hANP, (2) a progressive fall in BP (from 181/127 to 165/109 mmHg) and plasma volume, (3) a probably baroreflex-mediated sympathetic activation, evidenced by raised heart rate and plasma norepinephrine levels, (4) an increase in serum free fatty acids and circulating insulin (+45%), (5) an enhanced diuresis (+770%) and excretion of sodium (+665%), chloride (+524%), phosphate (+518%), other electrolytes, amino acids and free water clearance, (6) biphasic responses in the glomerular filtration rate (GFR) and p-aminohippurate (PAH) clearance, with initial increases (+40 and 30%, respectively) followed by a rapid return to (GFR), or even a fall below (PAH clearance) control values, and (7) a marked rise in the filtration fraction. Plasma antidiuretic hormone and urinary prostaglandin E2, F2 alpha and dopamine levels were not modified during alpha-hANP infusion, while plasma renin increased. Discontinuation of alpha-hANP was followed by rises in plasma aldosterone, the aldosterone:renin ratio and cortisol. Compared with previously studied normal subjects, in the hypertensive patients alpha-hANP caused a distinctly greater diuresis and electrolyte excretion but lowered BP only slightly more. In essential hypertension, as in normal man, alpha-hANP circulates in the blood and may exert a wide spectrum of cardiovascular, metabolic, endocrine and renal actions.

Adult↗
PubMed1986

Plasma kinetics of synthetic alpha-human atrial natriuretic peptide in man.

Atrial natriuretic peptides (ANPs) circulate in the blood stream and may modulate the regulation of blood pressure, sodium-fluid volume state and renal function. In man, alpha-human ANP (alpha hANP) is probably the major circulating form of ANP. To evaluate its plasma kinetics, we studied in 7 healthy men plasma alpha hANP concentrations under basal conditions and at short intervals during and up to 40 min after discontinuation of a 45-min constant alpha hANP infusion at a rate of 0.1 microgram/min/kg. From basal levels averaging 75 +/- 18 pg/ml (mean +/- SEM), plasma alpha hANP concentrations increased to 1,185 +/- 321 and 1,117 +/- 175 pg/ml at 30 and 40 min during the alpha hANP infusion, respectively. After discontinuing the latter, plasma alpha hANP decreased rapidly, following first-order kinetics, with a plasma half-life of 3.2 +/- 0.4 min. This finding is in line with the brief effects of intravenously applied alpha hANP and suggests that this system may be designed for rapid minute-to-minute adjustments.

Adult↗
PubMed1986

Under new management.

Explore the source record for details and available documents.

Health Services Administration↗
PubMed1985

Balloon cytology in screening of asymptomatic alcoholics for esophageal cancer, Part I.

We assessed the feasibility of using balloon cytology to screen an asymptomatic group of alcoholics at increased risk for esophageal cancer. The results indicate that this group can be studied with minimal morbidity and that useful material can be obtained in 85% of subjects. Keratinization was present in 68% of specimens and fungus was noted in 9%. Individuals with moderate to large amounts of keratinization consumed significantly more alcohol than those without cytologic evidence of keratin. We speculate that keratinization and fungus may represent markers of enhanced malignant potential in this population.

Adult↗
PubMed1985

Hypercalcemia associated with increased circulating 1,25 dihydroxyvitamin D in a patient with pulmonary tuberculosis.

Studies are described in a 53-year-old man with far-advanced pulmonary tuberculosis who developed transient increases in circulating 1,25 dihydroxyvitamin D (1,25(OH)2D) and hypercalcemia while on antituberculous treatment. Serial dilution of an extract of the patient's serum obtained while he was hypercalcemic displaced [3H]-1,25(OH)2D3 from chick intestinal receptor in a manner identical to authentic 1,25(OH)2D3. Serum 25-hydroxyvitamin D (25OHD) was suppressed during the abnormal elevation of serum 1,25(OH)2D. It is concluded that tuberculosis is another chronic granulomatous disease in which hypercalcemia may result from abnormal metabolism of vitamin D.

Animals↗
PubMed1985

Association between amino acid alterations and hallucinations in alcoholic patients.

Because available evidence suggests that alterations in the serotonergic as well as dopaminergic tones underlie hallucinatory activity, we decided to investigate whether serotonin and dopamine pathways are modified in alcoholics with a history of hallucinosis. Brain serotonin has been shown to depend on the plasma ratio of its precursor tryptophan over other amino acids competing with it for brain entry. Similarly, brain dopamine depends on the plasma ratio of its precursors phenylalanine and dopamine over their competitors. Amino acid abnormalities are common in alcoholics. For this reason, we assessed whether alcoholics who had experienced hallucinations have alterations in amino acids believed to be associated with neurotransmitter modifications. Patients with a history of hallucinations were found to have a tryptophan ratio significantly lower than that of patients without such a history, and a tyrosine + phenylalanine ratio significantly higher. These data suggest that amino acid abnormalities believed to result in decreased brain serotonin and in increased brain dopamine render certain individuals more vulnerable to hallucinatory experiences.

Adult↗
PubMed1985

Specificity of monoclonal antibodies directed against human and murine class II histocompatibility antigens as analyzed by binding to HLA-deletion mutant cell lines.

The specificity of 70 monoclonal anti-Ia monoclonal antibodies (MoAbs) (18 mouse allo-induced and 52 rodent anti-human) was studied with a panel of 17 HLA-deletion mutants that were derived from a single parent line and vary in expression of Ia antigens due to deletion of different subregions of HLA. MoAb binding was analyzed both by ELISA and flow microfluorometry. Characterization of the MoAbs with respect to specificity for products of subregions of a DR1-DC1-SB2 haplotype revealed great complexity. Many antibodies were quite specific for DR-linked determinants (26 MoAbs), DC-linked determinants (5 MoAbs), or determinants indistinguishable from SB (4 MoAbs). However, many MoAbs bound to products of more than one subregion: DR + SB (+/- weak DC) (22 MoAbs); DR + DC (3 MoAbs); or DR + DC + SB (1 MoAb). Furthermore, a number of the MoAbs bound unequally to products of the two HLA haplotypes analyzed, particularly among those recognizing DC1-linked determinants and the murine alloinduced MoAbs. Finally, despite strong structural homologies of murine I-A to human DC and murine I-E to human DR, the intraspecies cross-reactions of MoAbs do not closely follow that pattern. These data: (1) illustrate the usefulness of HLA-deletion mutant cell lines for analysis of the specificity of MoAbs and for delineation of HLA subregions; (2) demonstrate the great diversity of MoAbs specific for class II molecules and the high frequency of MoAbs that bind to products of more than one Ia subregion, particularly DR and SB. In view of such complexity, many (perhaps most) MoAbs cannot be relied on to unambiguously identify products of a particular Ia subregion, without extensive characterization.

Animals↗
PubMed1985

Evidence for alteration of the vitamin D-endocrine system in obese subjects.

Serum immunoreactive parathyroid hormone (PTH) is increased in obese as compared with nonobese subjects and declines with weight loss. To determine whether alteration of the vitamin D-endocrine system occurs in obesity and whether ensuing secondary hyperparathyroidism is associated with a reduction in urinary calcium, a study was performed in 12 obese white individuals, five men and seven women, and 14 nonobese white subjects, eight men and six women, ranging in age from 20 to 35 yr. Body weight averaged 106 +/- 6 kg in the obese and 68 +/- 2 kg in the nonobese subjects (P less than 0.01). Each of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium and 900 mg of phosphorus. Whereas mean serum calcium, serum ionized calcium, and serum phosphorus were the same in the two groups, mean serum immunoreactive PTH (518 +/- 48 vs. 243 +/- 33 pg/ml, P less than 0.001), mean serum 1,25-dihydroxyvitamin D [1,25(OH)2D] (37 +/- 2 vs. 29 +/- 2, P less than 0.01), and mean serum Gla protein (33 +/- 2 vs. 24 +/- 2 ng/ml, P less than 0.02) were significantly higher, and mean serum 25-hydroxyvitamin D (25-OHD) (8 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001) was significantly lower in the obese than in the nonobese men and women. Mean urinary phosphorus was the same in the two groups, whereas mean urinary calcium (115 +/- 10 vs. 166 +/- 13 mg/d, P less than 0.01) was significantly lower, and mean urinary cyclic AMP (3.18 +/- 0.43 vs. 1.84 +/- 0.25 nM/dl GF, P less than 0.01) and creatinine clearance (216 +/- 13 vs. 173 +/- 6 liter/d, P less than 0.01) were significantly higher in the obese than in the nonobese individuals. There was a significant positive correlation between percentage of ideal body weight and urinary cyclic AMP (r = 0.524, P less than 0.01) and between percentage of ideal body weight and serum immunoreactive PTH (r = 0.717, P less than 0.01) in the two groups. The results provide evidence that alteration of the vitamin D-endocrine system in obese subjects is characterized by secondary hyperparathyroidism which is associated with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D. The reduction of serum 25-OHD in them is attributed to feedback inhibition of hepatic synthesis of the precursor by the increased serum 1,25(OH)2D.

Adult↗
PubMed1985

Evidence for alteration of the vitamin D-endocrine system in blacks.

As compared with values in white subjects, bone mass is known to be increased and urinary calcium to be diminished in black individuals. To evaluate the possibility that these changes are associated with alterations in the vitamin D-endocrine system, an investigation was performed in 12 black subjects, 7 men and 5 women, and 14 white subjects, 8 men and 6 women, ranging in age from 20 to 35 yr. All of them were hospitalized on a metabolic ward and were given a constant daily diet containing 400 mg of calcium, 900 mg of phosphorus, and 110 meq of sodium. Whereas mean serum calcium, ionized calcium, and phosphate were the same in the two groups, mean serum immunoreactive parathyroid hormone (350 +/- 34 vs. 225 +/- 26 pg/ml, P less than 0.01) and mean serum 1,25-dihydroxyvitamin D (1,25(OH)2D) (41 +/- 3 vs. 29 +/- 2 pg/ml, P less than 0.01) were significantly higher, and mean serum 25-hydroxy-vitamin D (25-OHD) was significantly lower in the blacks than in the whites (6 +/- 1 vs. 20 +/- 2 ng/ml, P less than 0.001). Mean urinary sodium and 24-h creatinine clearance were the same in the two groups, whereas mean urinary calcium was significantly lower (101 +/- 14 vs. 166 +/- 13 mg/d, P less than 0.01) and mean urinary cyclic AMP was significantly higher (3.11 +/- 0.47 vs. 1.84 +/- 0.25 nM/dl glomerular filtrate, P less than 0.01) in the blacks. Further, the blacks excreted an intravenous calcium load, 15 mg/kg body weight, as efficiently as the whites (49 +/- 3 vs. 53 +/- 3%, NS). Mean serum Gla protein was lower in blacks than in whites (14 +/- 2 vs. 24 +/- 3 ng/ml, P less than 0.02), and increased significantly in both groups in response to 1,25(OH)2D3, 4 micrograms/d for 4 d. There was a blunted response of urinary calcium to 1,25(OH)2D3 in the blacks, and mean serum calcium did not change. The results indicate that alteration of the vitamin D-endocrine system with enhanced renal tubular reabsorption of calcium and increased circulating 1,25(OH)2D as a result of secondary hyperparathyroidism may contribute to the increased bone mass in blacks. Their low serum 25-OHD is attributed to diminished synthesis of vitamin D in the skin because of increased pigment.

Adult↗
PubMed1985

Inhibitory effect of a human T cell hybrid factor on both cell growth and mixed lymphocyte reactivity. Correlation with class II molecule expression.

We recently reported the biological activity and some of the biochemical characteristics of a factor produced by a human T cell hybrid clone able to block hematopoietic progenitor cell proliferation. This 85-kD protein factor, which we have termed colony-inhibiting lymphokine (CIL), has growth regulatory activity on bone marrow precursors bearing Ia (class II) antigens of either granulocytic-monocytic (CFU-GM) or erythroid lineage (BFU-E and CFU-E). Experiments aimed to investigate the specificity of the inhibitory effect on hematopoietic progenitor cell growth suggested that the expression of HLA-DR surface antigens was required on the target cells. We describe in this communication how DR+ cell lines ceased dividing after a few days of culture in the presence of CIL, whereas DR- cell lines were completely unaffected. The increased DR expression on the ML3 cell surface, mediated by the activity of the gamma interferon (IFN gamma), increases the sensitivity to the growth inhibition factor of the ML3 cell line. To verify the hypothesis that the DR antigens might serve as receptors for the factor, enabling it also to interfere in the immune response, we tested CIL in a mixed lymphocyte reaction (MLR), one of the best known in vitro Ia antigen-dependent T cell-mediated immune responses. CIL is able to block major histocompatibility complex-allogeneic MLR both in human and mouse systems. The data indicate that CIL recognizes a nonpolymorphic structure (presumably on all Ia molecules) presented by stimulator cells of either species, and thereby interferes with specific interactions between stimulator and responder cells. Blocking of the alloantigen stimulation stage is also indicated, since CIL is effective only if added to the culture medium during the first 48 h of the MLR. Finally, mouse monoclonal anti-DR antibodies are able to sharply reduce CIL activity on sensitive DR+ cell lines. CIL may act physiologically as a multifunctional mediator in a complex network that links regulation of bone marrow differentiation and the generation of immune responses.

Animals↗
PubMed1985

Assuring quality and confidence in new home care technologies.

In summation, a quality assurance program must prepare itself to succeed. The groundwork is often tedious and the orchestration of "hi-tech" programs no easy task. But by spending the time required in the development and educational phases, you will effectively avoid the common pitfalls in implementation of "hi-tech" programs. Patient care will run smoothly from beginning to end. All people involved will receive satisfaction in knowing that no compromise in quality is necessary in the transition from the hospital to the home setting.

Home Care Services↗