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Biomedical subjects

V L Go

Publications and source records attributed to V L Go.

At least 289 records · Page 16Linked to original sources
PubMed1976

Regulation of pancreatic and gallbladder functions by intraluminal fatty acids and bile acids in man.

The effects of intraduodenal glycerol, fatty acid (FA) chain length and FA loads, and bile acid (BA) concentrations on pancreatic and gallbladder function were investigated in 31 healthy volunteers by a perfusion method. FA absorption rates in the duodenum and proximal jejunum were measured simultaneously. Pancreatic and gallbladder responses were augmented by increasing FA chain length and FA loads until the "maximal" secretory capacity of the pancreas and gallbladder emptying was attained. Glycerol had no effect. Raising BA concentrations above the critical micellar concentration accelerated FA absorption rates but decreased the magnitude of pancreatic and gallbladder responses to FA. Higher BA concentrations exerted an opposite effect, slowing FA absorption and increasing pancreatic and gallbladder responses. Indeed, a significant, inverse correlation was found between FA absorption and pancreatic and gallbladder responses to FA, suggesting a relationship between the length of intestine exposed to FA and the amount of cholecystokinin (and/or other neurohormonal factors) released, which stimulates pancreatic secretion and gallbladder contraction.

Adult↗
PubMed1976

Pancreatic, gallbladder, and gastric responses to intraduodenal calcium perfusion in man.

To determine the effect of intraduodenal calcium on pancreatic, gallbladder, and gastric functions in healthy man, a validated perfusion method was employed to quantify total pancreatic, biliary, and gastric outputs during duodenal perfusion of either 6 mM, 12 mM,or 25 mM of elemental calcium (as isotonic calcium chloride solutions). Intraluminal calcium stimulated pancreatic enzyme secretion and gallbladder contraction in a dose-related fashion, achieving comparable responses to those produced by intravenous cholecystokinin-pancreozymin (CCK-z). Responses to calcium were reproducible when repeated in the same individual. Gastric acid outputs and serum gastrin levels increased significantly only with higher calcium perfusions (25 mM). Although duodenal calcium perfusion (25 mM) slightly increased serum calcium concentrations, induced hypercalcemia (by intravenous calcium infusion) of similar magnitude had no effect on pancreatic or gallbladder function. It is suggested that intraduodenal calcium may induce release of CCK-PZ (and/or other neurohormonal factors) from the gut, causing stimulation of these digestive organs.

Adult↗
PubMed1976

Measurement of gastric functions during digestion of ordinary solid meals in man.

A method of measuring gastric secretions and emptying rates after ingestion of an ordinary (solid-liquid) meal has been developed and validated. The technique quantifies movements of volume across the pylorus using constant duodenal perfusion with a nonabsorbable marker, polyethylene glycol (PEG), which, in turn, quantifies emptying into the duodenum of another marker, [14C]PEG, incorporated in the meal. Acid and pepsin outputs can be determined without manipulation of the intragastric pH. Employing this method, we have simultaneously quantified acid, pepsin, and total secretory outputs; rates of gastric emptying of meal and secretions; and serum gastrin levels during digestion. These data characterize physiological responses to ordinary food in health.

Adult↗
PubMed1976

Immunohistochemical identification of the cholecystokinin cell in the intestinal mucosa.

In indirect immunofluorescence tests, antibodies against pure porcine cholecystokinin (CCK) have detected specific CCK cells in the duodenal and jejunal mucosa of the dog and man. The CCK cells were scattered in the epithelium of the crypts, although some were in the villi. No CCK cells were found in the stomach, pancreas, terminal ileum, or colon. Some pyloric G cells also showed some reactivity with CCK antiserum, but absorption of CCK antiserum with gastrin C terminal pentapeptide prevented the staining of pyloric cells and provided specific staining of intestinal CCK cells. Anti-human gastrin I serum stained some intestinal cells too. Most of such cells did not react when gastrin antiserum was absorbed with pure CCK (a treatment that did not prevent the staining of pyloric gastrin cells); they were interpreted as cross-reacting CCK cells rather than as intestinal gastrin cells.

Animals↗
PubMed1976

Effect of liquid diet on serum protein binding and prednisolone concentrations after oral prednisone.

After prednisone (two 5 mg tablets) was given to each of six normal volunteers with water or with a liquid meal, standard pharmacokinetic parameters of prednisolone metabolism were similar, except that peak serum prednisolone concentrations occurred later after the meal. We conclude that prednisone can be given with a meal without significantly affecting the metabolism of prednisone or prednisolone.

Administration, Oral↗
PubMed1976

The influence of hypercalcemia on basal and cholecystokinin-stimulated pancreatic, gallbladder, and gastric functions in man.

Hypercalcemia produced in normal volunteers by intravenous infusions of CaCl2 increased outputs of pancreatic enzyme and gastric acid. Further, hypercalcemia enhanced cholecystokinin (CCK)-stimulated pancreatic enzyme secretion and gallbladder contraction. Our results suggest that hypercalcemia affects pancreatic, gallbladder, and gastric functions as well as their responses to exogenous CCK.

Adult↗
PubMed1976

Hemoccult stool tests: false-negative results due to storage of specimens.

Stoll samples mixed with 0 to 38 mg of hemoglobin per gram of stool were tested for occult blood by the Hemoccult (HO) method when fresh and after storage for 1 to 14 days. The intensity of the HO reaction in fresh stool samples was directly related to the hemoglobin concentration, and approximately 8 mg/g was required for a positive reaction. After samples had been stored on HO cards for 4 days, the intensity of the HO reaction was decidedly less in all. Except at the highest concentrations studied, all became HO-negative or trace within 8 days. In contrast, samples of most concentrations that were stored in tightly capped containers prior to preparation of HO cards maintained a positive reaction intensity for 1 week. Nevertheless, the intensity of the HO reaction decreased significantly (P less than 0.01) with each method of storage. No false-positives were induced by storage during this portion of our study. Samples from 100 stool specimens sent to the clinical laboratory for determination of occult blood were also smeared on separate HO cards for testing immediately and after 4, 7, or 10 days of storage. Only one positive HO reaction was observed on an HO card prepared from a specimen initially classified as HO-negative. In contrast, up to 40% of the stored HO cards prepared from specimens initially classified as HO-positive were HO-negative when analyzed 4 days later.

False Negative Reactions↗
PubMed1976

Development of radioimmunoassays for prednisone and prednisolone. Application to studies of hepatic metabolism of prednisone.

Radioimmunoassays for measuring prednisone and prednisolone (delta1 corticosteroids) in serum have been developed. By using 6,7-3H-delta1 corticosteroids as tracer, rabbit antibodies against delta1 corticosteroid-21-hemisuccinate in bovine serum albumin, and ammonium sulfate precipitation, the assays detected less than 0.8 ng/ml of delta1 corticosteroid and interassay coefficients of variation were less than 8.5 %. The specificity of antibodies, tested against all drug metabolites and major endogenous steroids, showed that only 21-glucuronic acid esters of delta1 corticosteroids had cross-reactivity of possible clinical importance. Assays were validated by measuring levels in samples of fastingstate sera with or without adding known amounts of prednisolone. Measurements of serum concentrations of both prednisone and prednisolone in normal dogs and in those with hepatic vascular exclusion were made after intravenous administration of prednisone. Although high levels of prednisolone appeared rapidly in normal dogs, only slight amounts were measured in dogs with hepatic vascular exclusion, which emphasized the importance of the liver in the conversion of prednisone to prednisolone, its active metabolite.

Animals↗
PubMed1975

Quantification of carcinoembryonic antigen-like activities in normal, human gastrointestinal secretions.

The secretion of carcinoembryonic antigen-like (CEA-like) material into the gastrointestinal tract of 28 fasting normal men was quantified by using intestinal perfusion techniques. CEA-like material was recovered from all levels of the gastrointestinal tract. The highest secretory rate was in the colon (mean +/- SE, 2.41 +/- 2.0 mug/minute per colon), followed by pancreatobiliary secretion and pancreatic secretion. The secretory rate from the stomach, duodenum, jejunum, and ileum was less than 20 ng/minute. After perchloric acid extraction, the CEA-like material from the colon had the same chromatographic and radioimmunologic properties as [125I] CEA. These data suggest that the CEA-like material is normally secreted into the gastrointestinal tract and particularly into the colon.

Adult↗
PubMed1975

Lower esophageal sphincter responses to enteric hormones in two patients with Zollinger-Ellison syndrome.

The effect of exogenous glucagon and secretin on resting lower esophageal sphincter (LES) tone during endogenous hypergastrinemia was studied in 2 patients with proven Zollinger-Ellison Syndrome (ZES). Intravenous glucagon and in one patient secretin, in dosages which decrease LES pressure in normals during LES stimulation by exogenous gastrin, caused a decrease in resting LES pressure in the ZES patients. This drop in LES tone occurred both during concomitant serum gastrin rise caused by secretin and serum gastrin decline caused by glucagon. This finding suggests that the action of secretin on LES pressure may be independent on endogenous gastrin, while the glucagon effect on LES tone may be mediated through gastrin.

Adult↗
PubMed1975

Clinical evaluation of urinary and serum carcinoembryonic antigen in bladder cancer.

Urinary carcinoembryonic antigen-like activity was increased (more than 1.5 ng. per ml.) in 61 per cent of patients with transitional cell carcinoma of the bladder. The frequency of abnormal carcinoembryonic antigen values correlated with the extent and the grade of the tumor. However, urinary tract infection can produce abnormal carcinoembryonic antigen values in non-cancer patients. The use of urinary carcinoembryonic antigen measurement and urine cytologic examination for diagnosis of transitional cell carcinoma gave a better diagnostic yield than did use of either test alone. In transitional cell carcinoma patients with abnormal preoperative urinary carcinoembryonic antigen values, postoperative urinary carcinoembryonic antigen values were useful for determining completeness of tumor resection. However, with total cystectomy and creation of an ileal conduit or ureterosigmoidostomy, urinary carcinoembryonic antigen values increased markedly postoperatively. Serum carcinoembryonic antigen values were of little value in the diagnosis of transitional cell carcinoma.

Carcinoembryonic Antigen↗
PubMed1975

The gastric response to a transpyloric duodenal tube.

The quantification of gastric, pancreatic, biliary, and small bowel functions in man often requires the use of intestinal tubes. In this study, the presence of a transpyloric tube did not alter gastric emptying, acid secretion, or serum gastrin levels in response to an ordinary solid meal.

Adult↗
PubMed1975

Hormonal requirements of the different cycles of the seminiferous epithelium during reinitiation of spermatogenesis in long-term hypophysectomized rats.

Restoration of testicular function in long-term hypo-physectomized rats given different hormonal treatments during the various cycles of the seminiferous epithelium was evaluated on the basis of the weights of testes, epididymides, and other accessory sexual glands, histological examination of testes, and determination of the numbers of spermatozoa/epididymis. The staput fractionation technique for the separation of classes of germinal cells was employed to provide a measure of the advancing front of pulse-labelled cells following the intratesticular administration of (3-H)thymidinemthe results suggested that during the first two cycles, in which spermatogonia develop into pachytene spermatocytes, either LH or testosterone alone was sufficient for partial restoration. During the third cycle of the seminiferous epithelium, LH and FSH were required to allow previously labelled pachytene spermatocytes to progress efficiently to stage 7 spermatids. Administration of LH alone during the final cycle was sufficient to permit stage 7 spermatids to develop into spermatozoa, provided LH plus H had been given during the previous three cycles. Injection of LH during the entire period and of FSH during the third cycle of the seminiferous epithelium was required to achieve Staput profiles characteristic of a normal advancing front of pulse-labelled cells, and to allow partial restoration of spermatogenesis. More complete restoration was obtained in rats given FSH and LH during the first three cycles but, with the doses employed, the number of spermatoza/testis remained subnormal. Efficient completion of each cycle of the seminiferous epithelium appeared to be hormone-dependent. The data are discussed in relation to the possibility that hormones may affect the general development of germinal cells in an indirect manner by their influence on Sertoli cell function.

Animals↗