Search PubMed⌕ Search

Biomedical subjects

J Hotz

Publications and source records attributed to J Hotz.

At least 91 records · Page 5Linked to original sources
PubMed1983

Calcium secretion from the feline pancreas. Influence of hormonal and cholinergic secretagogues and of serum calcium.

The influences of secretagogues and of elevated serum calcium concentrations on the calcium secretion from the cat pancreas have been studied in vivo. During a high and constant fluid secretion rate evoked by a background infusion of secretin, additional infusions of both cholecystokinin-pancreozymin and urecholine led to a dose-dependent increase in calcium secretion in pancreatic juice parallel to the rise of protein. The amount of calcium in pancreatic juice associated to 1 mg protein (18.3 nmol/mg protein) calculated from regression analysis was independent of dose or kind of stimulus used. The protein-independent pancreatic juice calcium fraction was 0.184 mM in normocalcemia. During an episode of hypercalcemia produced by an intravenous calcium infusion, the protein-independent calcium fraction was increased and correlated linearly to the serum calcium concentration. We conclude that pancreatic juice calcium consists of two major fractions, one being associated with the enzyme protein and stimulated by secretagogues, and the other being protein independent and directly dependent on the extracellular calcium concentration.

Animals↗
PubMed1983

Short-term inhibition of duodenal tryptic activity does not affect human pancreatic, biliary, or gastric function.

Existence of feedback inhibition of pancreatic secretion by luminal pancreatic trypsin in humans is controversial. We examined the effect of duodenal tryptic activity on pancreatic, biliary, and gastric functions. In six healthy volunteers, gastric acid secretion and emptying and the secretion of pancreatic enzymes, bicarbonate, and bile acids into the duodenum were measured for 7 hr with a double-marker perfusion technique. Each experiment consisted of six test periods. The effects of the addition of active and inactive aprotinin to duodenal saline perfusion were determined during fasting and after administration of a saline test meal. We found that (1) aprotinin eliminated tryptic activity in the preprandial state and reduced it by more than 95% during meal periods; (2) compared to inactivated aprotinin, no differences in the outputs of bicarbonate, amylase, lipase, chymotrypsin, and bile acids occurred during preprandial or postprandial aprotinin periods; and (3) gastric acid secretion, emptying, and duodenogastric reflux were similar during aprotinin and inactivated-aprotinin perfusions. We conclude that short-term, almost complete reduction of intraduodenal tryptic activity does not alter exocrine pancreatic secretion or gastric function in the unstimulated state or in response to a moderate stimulation by a saline test meal. Therefore the importance of negative feedback control of pancreatic secretion by acute alteration of intraduodenal tryptic activity must be questioned in healthy humans.

Adult↗
PubMed1982

Comparison of the morphological alteration and disintegration test (MADT) and the chimpanzee infectivity test for determination of hepatitis B virucidal activity of chemical disinfectants.

The morphological alteration and disintegration test (MADT) as a key indicator for Hepatitis B Virus (HBV) inactivation was compared with the chimpanzee infectivity test using three suspensions of HBV differing in the degree of inactivation as judged by electronmicroscopic studies. The results of the MADT and the chimpanzee studies correlated well. Thus, the MADT, evidently, can replace the laborious, costly and time-consuming animal studies for the evaluation of chemical disinfectants for hepatovirucidal activity.

Aldehydes↗
PubMed1981

Effects of clanobutin on pancreatic secretion in vitro.

The effects of clanobutin (4-[4-chloro-N-(4-methoxyphenyl)-benzamido]butyric acid) were investigated on two in vitro pancreatic preparations. In rat pancreatic lobules clanobutin (7.2 mM) stimulated the secretion of amylase and radiolabeled proteins to the same or higher extent as did CCK-PZ and carbachol in maximally active doses, but with a delay of 1-2 h. In the isolated rabbit pancreas clanobutin (3.3 mM) stimulated protein secretion about half as much as did carbachol, but without significant delay. The effect of clanobutin on protein secretion was prevented by prior application of carbachol, was not affected by the omission of Ca2+ from the medium and was only partly inhibited by the presence of atropine (0.1 mM). Prior addition of clanobutin did not prevent the effects of carbachol on enzyme secretion. In addition, clanobutin (3.3 mM) inhibited fluid secretion in the rabbit pancreas by about 50 percent; the inhibition was reversible. No effects on paracellular permeability were found with sucrose used as test substance. The findings indicate that clanobutin has opposite effects on enzyme and fluid secretion by rat and rabbit pancreas, which are not due to circulatory effects.

Amylases↗
PubMed1981

[New aspects of inflammatory pancreatic diseases].

The diagnostic aids of acute pancreatitis include the clinical presentation, laboratory investigations and abdominal sonography. The assessment of amylase creatinin clearance ratio is not superior to simple amylase estimations in identifying unspecific hyperamylasemias apart from acute pancreatitis. The management of acute pancreatitis consists of a standardized basic treatment which does not depend on the degree of the severity of the disease and supplementary measures which are adjusted to the degree of severity and complications. In case of chronic pancreatitis a variety of indirect and direct morphological and functional examinations are available. The diagnostic safety of all procedures--each taken by its own--is below 90%; however, the combined use has to be adjusted to the severity of the symptoms suspicious of pancreatis disease. The therapeutic goal includes the conservative management of the painful recurrences to achieve transmission into the final stage of the disease which presents only minor symptoms. Operation has to be considered in case of untreatable pain and local complications. The obstruction of the pancreatic duct by means of synthetic glue instillations is a hopeful approach.

Acute Disease↗
PubMed1981

[Endocrinologic findings in Crohn's disease].

In 45 patients with radiologically and endoscopically/histologically proven Crohn's disease the partial functions of the anterior pituitary gland were measured prior to steroid therapy. No deficiencies were observed with respect to cortico-, thyro-, gonado-, and somatotropic functions. In 25 out of 40 patients (63%) the typical diurnal rhythm of cortisol secretion was absent when assessed by a distinctly elevated 6 p.m. cortisol serum level. In about one fourth of 22 patients T3-RIA was reduced, indicating deficiency of conversion from T4 to T3. Six (43%) out of 14 males showed reduced basal testosterone levels at 8 a.m. and 6 p.m. which, in 4 out of 14 cases, did not increase sufficiently in response to HCG. The basal LH-level was elevated in 9 (50%) of 18 males. The lack of diurnal rhythm of cortisol secretion and primary insufficiency of Leydig's cells did not correlate with the activity of the disease.

Adolescent↗
PubMed1981

Pharmacological actions of calcitonin on the gastrointestinal tract and their therapeutical implications.

The role of calcitonin (CT) in the regulation of the calcium homeostasis in humans is doubtful, while the therapeutic use in various bone diseases gains increasing interest. Numerous investigations during the last eight years have indicated that CT affects a variety of gastrointestinal organs when CT is administered in pharmacological high doses: CT inhibits gastric acid and pepsin secretion, gastrin release, pancreatic enzyme secretion as well as the hormonally stimulated contraction of the lower esophageal sphincter and of the gallbladder. CT increases intestinal secretion. The therapeutic use of CT in gastric hypersecretory states appears to be inferior and less practicable compared to the histamine-H2-receptor antagonists. The benefit of CT in the clinical course of acute pancreatitis was observed in two controlled double blind studies but CT did not lower the mortality rate. CT does not influence increases in serum-amylase and -lipase occurring after ERCP.

Acute Disease↗
PubMed1981

[Excretion of lead in the gastric and duodenal juice of persons with occupational lead poisoning and normal subjects].

Lead was measured in the gastric and duodenal juice of three patients with lead poisoning (blood concentrations of lead: 4.30; 5.16; 5.50 mumol/l). The lead excretion into the gastric juice was 94.6; 29.9 and 18.3 nmol Pb X h-1 for the poisoned persons and 57.9 +/- 38.1 nmol Pb X h-1 for healthy persons (n = 20). Pentagastrin (6 microgram/kg, i.m.) stimulated lead excretion in both groups (normal + 109%, lead poisoned persons: + 180%; + 187%; + 311%). The lead excretion was correlated with an increase of HCl-secretion and volume in healthy persons. The lead excretion into the duodenal juice after secretion (1 unit/kg) amounted to 14.2 +/- 8.8 nmol Ph X h-1 in healthy persons, whereas after secretion plus caerulein 18.8 +/- 7.2 nmol Pb X h-1 were found. In the duodenal juice of the lead poisoned persons 27.5 and 474.9 nmol Ph X h-1 respec. were found after secretion and 58.9 and 491.8 nmol Pb X h-1 respec. after secretion plus caerulein. Lead excretion was correlated with enzyme secretion (trypsin and chymotrypsin).

Ceruletide↗
PubMed1980

Inhibition of human gastric secretion by intragastrically administered calcitonin.

The effects of intragastrically administered synthetic human calcitonin (H-CT) and salmon calcitonin (S-CT) on human gastric secretion have been compared with the effects of both CTs after intravenous infusion. Basal as well as pentagastrin-stimulated acid and pepsin output were lowered by about 50% in response to a single intragastric instillation of H-CT while an intravenous infusion of H-CT produced an inhibition of more than 70%. After intragastric instillation, dose-response curves of H-CT and S-CT were in a similar range when the dose was referred to the molarity of CT; however, related to the biological activity of CT (MRC units), S-CT was about 10--15 times less effective than H-CT. Conversely, after intravenous infusion, equal doses in reference to MRC units evoked similar responses while in reference to molarity S-CT was 20--30 times more effective than H-CT. Radioimmunological determinations of H-CT showed after intragastric instillation a stepwise decrease in concentration of H-CT in the gastric juice and no appearance of H-CT in the blood. In contrast, after intravenous administration of H-CT, no detectable H-CT activity was secreted into the juice in the presence of a peak increase in serum-immunoreactive H-CT. From the differences in the effects of CT observed after intragastric and intravenous administration, respectively, it is suggested that intragastrically administered CT might inhibit gastric secretion via local mechanisms on the gastric mucosa.

Adult↗
PubMed1980

Immunoreactive secretin release following taurocholate perfusions of the cat duodenum.

Perfusion of the cat duodenum with sodium taurocholate (TC), 120 mmol/l, at pH 6.1 increased the plasma immunoreactive (IRS) concentration from 2.2 +/- 0.7 pmol/l to 29 +/- 6.1 pmol/l during the first 20 min. This was accompanied by an increased pancreatic secretion of fluid, while the chymotrypsin output showed a "wash-out' phenomenon. TC increased both the bile-acid-dependent and the bile-acid-independent bile secretion. In comparison, HCl, 150 mmol/l, increased IRS from 0.9 +/- 0.5 pmol/l to 41 +/- 15 pmol/l, producing an increase in the pancreatic fluid secretion. However, only a slight increase in the bile-acid-independent bile secretion was found, and the bile-acid-dependent secretion did not change. The effects of TC on the pancreatic secretion were produced at concentrations occurring in cat hepatic bile.

Animals↗
PubMed1980

Stimulation of bile and pancreatic secretion by duodenal perfusion with Na-taurocholate in the cat compared with jejunal and ileal perfusion.

In the anesthetized cat duodenal perfusion with Na-taurocholate (TC, 0.2 M, pH 6.1, 290 mosmol, 45 ml x h-1) stimulated pancreatic volume (0 to 326 +/- 236 mg x 10 min-1) and bicarbonate secretion (0 to 34.2 +/- 4.1 mumol x 10 min-1), whereas pancreatic enzyme output was sparse. Simultaneously with the pancreatic response, bile flow increased from 139 +/- 74 mg to 484 +/- 146 mg x 15 min-1 (p < 0.05). During perfusion of the upper jejunum both pancreatic and biliary responses were significantly lower than the responses to duodenal TC perfusion (p < 0.05). During TC perfusion of the terminal ileum there was no response from the pancreas, whereas the increase in bile flow accounted only for an increase in the bile-acid-dependent fraction. The concomitant stimulation of both the hydrokinetic function of the pancreas and the bile-acid-independent bile flow might be mediated by a release of secretin.

Animals↗