The x-ray diffraction study of the C-terminally unprotected tripeptide benzyloxy-carbonyl-L-alanyl-alpha-aminoisobutyl-alpha- aminoisobutylic acid (Z-L-Ala-Aib-Aib-OH) has shown that the molecule adopts a consecutive type III beta-turn, which characterizes a right-handed 3(10) helix. A very weak 4----1 intramolecular hydrogen bond with the long N...O distance of 3.32 A, and a unique "oxy analogue" of the 4----1 hydrogen bond wih the O...O distance of 2.77 A, were observed. The stability of the observed conformation with the asymmetric Aib residues was theoretically evaluated by a conformation-energy calculation. The stereochemical characteristics of Aib and Ala residues were made clear by a comparison of the conformations of the short peptides containing both Aib and Ala residues.

Amino Acid Sequence↗

PubMedDate not supplied

Bile acid malabsorption as a cause of hypocholesterolemia seen in patients with chronic pancreatitis.

A determination of caloric consumption based on a dietary survey table, fat and cholesterol intake, and analyses of fecal fatty acids and neutral sterols, and bile acid analysis (gas chromatographic method) were conducted on 33 subjects (including 17 patients with chronic pancreatitis and 16 normal controls). The factors related to hypocholesterolemia in chronic pancreatitis (CP) patients were investigated and the following conclusions were obtained: (1) The total caloric intake and fat consumption by the CP patients were significantly lower with the exception of cholesterol consumption. (2) Significant increases were noted in fecal fat, neutral sterols, and bile acid excretion by the CP patients. (3) A significant positive correlation was noted between the total cholesterol and body mass index (BMI), reaffirming that the cholesterol level can be used as an indicator of nutritional status. (4) A significant negative correlation was noted between the serum total cholesterol and fecal bile acid excretion. These findings indicate that CP patients suffer from neutral sterol malabsorption, in addition to dietary fat maldigestion and bile acid malabsorption. Furthermore, bile acid malabsorption is cited as a factor in the development of hypocholesterolemia in CP patients.

Adult↗

PubMedDate not supplied

Effect of omeprazole on changes in gastric and upper small intestine pH levels in patients with chronic pancreatitis.

Gastric and upper small intestine pH levels were measured continuously over 24 hours in patients with chronic pancreatitis, and values obtained before and after the administration of omeprazole were compared. Additionally, omeprazole was administered for 2 weeks and the fecal excretion of fat was compared before and after drug therapy. Postprandial gastric pH levels, initially 2.9 to 3.2, increased by 1.6 to 2.1 after treatment. Postprandial upper small intestine pH levels, initially 5.1 to 5.5, increased by 0.7 to 1.0. The lowest pH value of the upper small intestine was 2.2 to 2.4 postprandially; this was increased by > 1.0 after omeprazole, and the amplitude of pH variation was reduced. The cumulative proportions of intraintestinal pH strata of < or = 3, < or = 4, or < or = 5, and higher, initially being 16.4% to 17.1%, 27.4% to 31.7%, and 52.6% to 57.8%, respectively, were remarkably improved after drug treatment. Gastric pH and upper small intestine pH levels showed a positive correlation; an increase in gastric pH levels by 2 corresponded to an increase in small intestine pH levels by 1. After omeprazole administration, mean fecal excretion of fat was decreased to 4.1 +/- 2.6 g/d (range, 1.1 to 9.8 g/d) from 6.5 +/- 3.9 g/d (range, 1.6 to 13.5 g/d). Decreases in excretion of fat averaged 3.4 g/d (range, 2.2 to 4.5 g/d) in patients with steatorrhea. It was concluded that steatorrhea due to chronic pancreatitis can be improved to some extent by improving upper small intestine pH levels following the elevation of gastric pH levels after administration of omeprazole.

Adult↗

PubMedDate not supplied

Oligodendroglioma with cystic component in infant.

In this report, we examine the case of a 6-year-old girl with a mixed oligodendroglioma demonstrating uncommon neuroradiological images. CT and MR showed an intratemporal mass with multilocular cystic formation and intratumoral massive calcification, suggestive either of astrocytoma, dysembryoplastic neuroepithelial tumor, or ganglioglioma as a presumptive differential diagnosis. The tumor was almost completely removed. Post-operative histological examination revealed a mixed oligodendroglioma with a small component of astrocytoma. The combination of radiotherapy and chemical treatment was supplemented.

Antineoplastic Agents↗

PubMedDate not supplied

Acute and chronic effects of hyperosmolality on mRNA and protein expression and the activity of Na-K-ATPase in the IMCD.

We investigated acute and chronic effects of hyperosmolality on mRNA and protein expressions of Na-K-ATPase alpha and beta isoforms and Na-K-ATPase activity in the rat inner medullary collecting duct (IMCD). Incubation of IMCD in hypertonic medium for 30 min reduced the Na-K-ATPase activity by 50%. The Na-K-ATPase activity of dehydrated rats measured in isotonic medium was decreased, and incubation in hypertonic medium did not further decrease the activity. Incubation of IMCD in hypertonic medium for 6 h did not change alpha(1) mRNA. In contrast, dehydration decreased alpha(1) subunit mRNA and protein and beta(1) protein expressions without changing beta(1) mRNA. These data show (1) that acute hyperosmolality decreases Na-K-ATPase activity in IMCD without changing alpha(1) and beta(1) mRNA and (2) that 2 days of dehydration decreased Na-K-ATPase activity by reducing alpha(1) and beta(1) proteins. Thus, the mechanisms for the inhibition of the Na-K-ATPase activity in IMCD is different between acute and chronic exposure to hyperosmolality.

Animals↗

PubMedDate not supplied

Effects of FL-386 on faecal lipid excretion in humans.

A newly synthesized inhibitor of pancreatic lipase and micelle formation, FL-386, was administered at a dose of 400 mg (in the diet, for seven consecutive days) to nine healthy adult volunteers, and changes in faecal mass, frequency of defaecation, and properties of the stools were observed. High performance liquid chromatography and gas-liquid chromatography were used to analyse the faeces for short-chain carboxylic acids, neutral sterols, bile acids, fats and hydroxyfatty acids. FL-386 had little effect on the amounts and composition of short-chain carboxylic acids, neutral sterols, and bile acids excreted, nor did it produce changes in the composition of fatty acids, or the percentages of hydroxyfatty acids in the stool. However, in those patients treated with FL-386, the faecal mass was increased, and stools were softer and contained increased amounts of fatty acids. The compound did not produce particularly fatty stools. It was concluded that FL-386 induces slight disturbance in the digestion and absorption of dietary lipids.

Adult↗