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Biomedical subjects

B Shapiro

Publications and source records attributed to B Shapiro.

At least 307 records · Page 17Linked to original sources
PubMed1980

Salivary gland dysfunction in systemic lupus erythematosus and rheumatoid arthritis. Diagnostic importance.

Salivary scintigraphy employing radionuclides has proved to be an accurate, reproducible method for demonstrating salivary gland involvement in Sjögren's syndrome. A prospective study was undertaken of 24 consecutive patients bearing a diagnosis of systemic lupus erythematosus (SLE), 78 consecutive patients bearing a diagnosis of classic or definite rheumatoid arthritis, and 18 control patients. Clinical of Sjögren's syndrome did not necessarily correlate with abnormal scintiscans. Extensive involvement, with greatly abnormal scintiscans (class 3 and 4), was found most consistently in patients who had SLE and who were seronegative for rheumatoid factor Salivary gland scintigraphy may ultimately serve as an adjunctive procedure for the diagnosis of this disease.

Adolescent↗
PubMed1979

Ultracentrifugation evidence for a somatostatin-binding protein in serum.

Using a technique of high speed centrifugation of serum and a well validated immunoassay for the measurement of serum somatostatin-like immunoreactivity, we have demonstrated that somatostatin, unlike other peptide hormones, appears to sediment with large molecular weight proteins. When synthetic somatostatin of increasing concentration was incubated with serum prior to ultracentrifugation, a linear plot of concentration of somatostatin added against concentration sedimenting (or apparently bound to protein) revealed an association curve. These data provide further evidence for the existence of a serum-binding protein for somatostatin.

Adult↗
PubMed1979

Palmitoyl coenzyme A synthetase activation by uncomplexed ATP.

Uncomplexed ATP, ADP, alpha, beta-methylene ATP and adenosinetetraphosphate were shown to activate long chain fatty acyl-coenzyme A synthetase. The presence of uncomplexed nucleotides was shown: (1) to induce the palmitoyl-AMP-dependent palmitoyl-coenzyme A formation, (2) to activate the MgATP-dependent overall reaction and (3) to stabilize the synthetase against ageing denaturation. In all three cases the observed nucleotide activation was shown to be eliminated upon metal chelation.

Adenine Nucleotides↗
PubMed1979

Growth hormone release inhibitory hormone-like immunoreactivity in pancreas and gut in streptozotocin diabetes in the rat and response to insulin administration.

In streptozotocin diabetes in the rat, growth hormone release-inhibitory hormone-like immunoreactivity (GHRIH-LI) content of pancreas, gastric antrum and colon was increased. Insulin therapy significantly lowered the increased pancreatic GHRIH-LI content but did not affect that of the gastric antrum and colon at the dosage used. The relevance of these findings in relation to pancreatic and gastrointestinal function in diabetes awaits clarification.

Animals↗
PubMed1979

Metabolic clearance and plasma half-disappearance time of exogenous somatostatin in man.

The MCR and half-disappearance time of exogenously administered somatostatin have been measured during and after cessation of a constant infusion. Studies were performed on normal volunteers and patients with chronic liver disease and failure. Immunoreactive somatostatin was measured by a sensitive and specific RIA using an antiserum directed against the core of the molecule. Normal subjects had a mean MCR of 1949 +/- 250 ml/min (28.4 +/- 4.2 ml/min . kg BW) (mean +/- SEM), similar to values found in five patients with chronic liver disease. However, patients with chronic renal failure showed a highly significant (P less than 0.001) lowering of the MCR (501 +/- 32.7 ml/min or 7.8 +/- 0.6 ml/min . kg). The rate of disappearance of somatostatin after infusion was linear for 7-10 min, after which a much slower component was observed. In normal subjects, the t 1/2 of the first component varied from 1.1-3.0 min, in patients with liver disease it varied from 1.2-4.8 min, and in patients with chronic renal failure it varied from 2.6-4.9 min. Exogenously administered somatostatin is rapidly cleared in normal subjects and patients with chronic liver disease, but the MCR in end stage chronic renal failure is markedly lowered. The kidney may have a role in the metabolic clearance of exogenously administered somatostatin, or uremia may impair catabolism nonspecifically.

Adult↗
PubMed1979

Tissue and serum somatostatin-like immunoreactivity in fed, 15-h-fasted, and 72-h-fasted rats.

Somatostatin-like immunoreactivity (SLI) was measured in extracts of gastric antrum, colon, pancreas, and central nervous system, as well as in unextracted portal and inferior vena caval serum from fed, 15-h-fasted, and 72-h-fasted rats. No differences were found in SLI in the central nervous system of the three groups. However, striking variations were found in the gastrointestinal tract and pancreas; the antrum, colon, and pancreas of 15-h-fasted rats contained the least SLI, the content being significantly elevated in these three areas after feeding and after a 72-h fast. Portal serum levels were highest after feeding but lowest in 72-h-fasted rats, in spite of high intestinal and pancreatic SLI content in both. These tissue and serum differences suggest a physiologic role for SLI in nutrient homeostasis not only at tissue level, but also putatively as a hormone in the portal system.

Animals↗
PubMed1978

Tissue growth hormone release inhibiting hormone-like immunoreactivity in experimental hypothyroidism and hypopituitarism.

Hypothyroidism in rats was associated with an increase in immuno-reactive GH-RIH in brain, pancreas and gut, although release from the latter may be diminished as portal GH-RIH-like immunoreactivity was lower than control values. Hypophysectomy resulted in a depletion of immunoreactive GH-RIH in the septum and preoptic area of the brain and gastric antrum, but an increase in pancreas; portal venous GH-RIH-like immunoreactivity was not different from control concentrations, possibly reflecting both elevated and lowered immunol-reactive GH-RIH in different regions of tissue subserved by the portal vein. Inferior vena caval GH-RIH-like immunoreactivity was always lower than in the portal vein and was not influenced by tissue pertubations in hypothyroidism and hypopituitarism which made regional blood sampling of great important in evaluating tissue changes.

Animals↗
PubMed1978

Somatostatin-like immunoreactivity in rat blood. Characterization, regional differences, and responses to oral and intravenous glucose.

Somatostatin-like immunoreactivity (SLI) has been demonstrated by radioimmunoassay (RIA) in rat serum using an antiserum specific for somatostatin and cross-reacting maximally with the biologically important area on the peptide. The RIA has a sensitivity of 35 pg/ml. SLI dilutes in parallel with synthetic somatostatin standard in the RIA and shows characteristics similar to synthetic somatostatin on Sephadex G-25 (f) gel chromatography eluting largely as a single peak with 1 M acetic acid. Significant regional differences in serum SLI are present. A positive gradient was found in paired samples from aorta (mean+/-SEM, 0.304+/-0.024 ng/ml) and portal vein (0.495+/-0.047 ng/ml) consistent with the known presence of somatostatin in gut and pancreas, and a negative gradient was noted between paired samples from portal vein (0.523+/-0.076 ng/ml) and hepatic vein (0.290+/-0.048 ng/ml) indicating hepatic clearance. No significant differences were demonstrated between aorta and confluence of cerebral venous sinuses or between aorta and inferior vena cava (IVC). After intragastric glucose, a significant and marked elevation of portal SLI was observed, maximal at 5 min (0.416+/-0.137 vs. 1.55+/-0.30 ng/ml at 5 min). A significant biphasic elevation of portal SLI also occurred after intravenous glucose. After both routes of glucose administration, the patterns of portal SLI followed closely those of portal glucose and insulin. By contrast, IVC SLI failed to reflect these changes.Thus, SLI in the rat shows chromatographic similarity with synthetic somatostatin. Regional differences in serum levels are marked; the highest concentrations being found in the portal venous effluent of pancreas and gut. Furthermore, glucose causes elevation of portal SLI in a pattern similar to portal insulin and glucose and without concomitant elevation in IVC. This differential elevation of SLI after glucose is consistent with a hormonal action within the portal system as a direct effect of somatostatin on the liver has previously been demonstrated. In addition, the liver is important in the clearance of portal SLI, possibly to prevent extraportal effects in response to gut and pancreatic stimulation. Finally, it is clear that regional sampling of serum for SLI measurement may be critical in the investigation of the putative physiological roles for somatostatin.

Animals↗