Biomedical subjects

J Rouse

Publications and source records attributed to J Rouse.

35 records · Page 2Linked to original sources

PubMed1992

Clinical value of endoscopy and histology in the diagnosis of duodenogastric reflux disease.

BACKGROUND: The endoscopic observation of a bile lake in the stomach, antral gastritis, or ulcerations and the histologic finding of foveolar hyperplasia or chronic gastritis have been implicated as indicators of excessive duodenogastric reflux. The accuracy of these criteria was evaluated in 135 patients with nonspecific symptoms in the foregut suggestive of duodenogastric reflux and no evidence for alcohol- or drug-induced gastric mucosal injury. METHODS: The presence of excessive duodenogastric reflux was objectively determined by means of both gastric pH monitoring and cholescintigraphy with cholecystokinin stimulation. RESULTS: Endoscopy showed antral gastritis in 67 patients, gastric ulcers in 19, and a bile lake in the stomach in 39 (total of 135 patients). Of 90 patients who underwent biopsy, histologic findings showed foveolar hyperplasia in 26, chronic gastritis in 19, and active gastritis in 28 patients. The latter condition was associated with Helicobacter pylori in 20 patients. When gastric pH monitoring, cholescintigraphy, or both were used as "gold standard," the sensitivity, specificity, accuracy, and positive predictive value of endoscopic and histologic criteria to diagnose the presence of excessive duodenogastric reflux were poor except in the rare case of active gastritis but no Helicobacter pylori. CONCLUSIONS: The presence of duodenogastric reflux disease cannot be accurately diagnosed with endoscopic or histologic criteria. The diagnosis should be made with objective techniques, particularly when surgical therapy is considered.

Biopsy↗

PubMed1991

Bovine glomerular basement membrane. Location and structure of the asparagine-linked oligosaccharide units and their potential role in the assembly of the 7 S collagen IV tetramer.

Collagen IV contains an amino-terminal tetramerization domain (7 S) that is involved in aggregation and cross-linking as part of the process of self-assembly of the collagen IV matrix of basement membranes. We determined the structure and location of the Asn-linked oligosaccharides of the 7 S tetramer. Two glycopeptides, GP-1 and GP-2, were isolated from tryptic digests of the 7 S tetramer and were characterized. GP-1 and GP-2 are derived from the alpha 1(IV) chain and the alpha 2(IV) chain, respectively. Each glycopeptide contained one sequence, -Asn-Xaa-Thr-, which was shown to be N-glycosylated at Asn, corresponding to position 126 of the alpha 1 chains and 138 of the alpha 2 chain. 1H NMR spectroscopic analysis of the oligosaccharide is a biantennary N-acetyllactosamine type of N-linked oligosaccharide with a broad heterogeneity in the presence of the sugar residues at their nonreducing termini as indicated. [formula: see text] The location of the Asn-linked oligosaccharide units and Hyl-linked disaccharide units and their orientation with respect to the surface of the triple helix were calculated using two models. We conclude that both units are important determinants in the assembly of the 7 S tetramer.

Amino Acid Sequence↗

PubMed1991

Bovine parathyroid glands secrete a 26-kDa N-terminal fragment of chromogranin-A which inhibits parathyroid cell secretion.

Chromogranin-A (CgA) is a ubiquitous protein which colocalizes in secretory granules of multiple endocrine tissues and cosecretes with peptide hormones from these tissues. Although the function of CgA has remained unknown, there has been recent interest in its potential role as a prohormone for smaller, biologically active peptides. We isolated and characterized a 26-kDa N-terminal fragment of CgA which is a natural breakdown product of bovine parathyroid CgA in storage. A similar, if not identical, fragment of CgA is secreted by bovine parathyroid glands. The secreted fragment elutes on HPLC and migrates on both sodium dodecyl sulfate-polyacrylamide gel electrophoresis and acid-urea gels in the same position as the 26-kDa N-terminal fragment. When added to the incubation medium of dispersed bovine parathyroid cells, the 26-kDa N-terminal fragment of CgA inhibits the low calcium-stimulated secretion of both PTH and CgA. This N-terminal fragment is homologous to betagranin, which is a 21-kDa N-terminal fragment of CgA that is generated from CgA in rat insulin granules. Thus, a naturally occurring betagranin-like N-terminal fragment of bovine parathyroid CgA is not only secreted itself, but can inhibit the secretion of PTH and intact CgA by bovine parathyroid cells. The processing of intact CgA to fragments such as the N-terminal fragment that we describe may be important in the autocrine or paracrine regulation of secretion.

Amino Acid Sequence↗

PubMed1990

Adult protective services for abused aged in Texas: program and research implications.

Explore the source record for details and available documents.

Adult↗

PubMed1988

A comparison of 30-kDa and 10-kDa hormone-containing fragments of bovine thyroglobulin.

Studies have been carried out on reduced and alkylated 19 S bovine thyroglobulin to characterize naturally occurring, iodine-rich fragments. In this report, the purification and properties of a 30-kDa, hormone-enriched polypeptide (TgE) are described and compared to that of a previously reported 10-kDa fragment (TgF). The amino acid sequence of TgF was found to overlap with that of TgE. In spite of its larger size, TgE contains only a single hormone bearing site. Both the 10- and 30-kDa fragments are derived from the NH2-terminal end of the bovine thyroglobulin. These fragments contain the principal hormone-forming site at residue 5 of the thyroglobulin sequence and appear to be formed by cleavage of the parent polypeptide chain. The mechanism which generates these cleavages is not clear since the sequences surrounding the cleavage points which give rise to these peptides are quite different. These two fragments may be precursor and product in such a process. The amino acid sequence contained within TgE includes two putative sites for N-linked glycosylation. Since no glucosamine was observed and only small amounts of neutral sugar were detected, it appears that this part of the molecule is not extensively glycosylated.

Amino Acid Sequence↗

PubMed1988

Purification and partial amino acid sequencing of alkaline phosphatase from rachitic rat epiphyseal cartilage.

1. Alkaline phosphatase of rachitic epiphyseal cartilage was purified to apparent homogeneity by sequential application of monoclonal affinity, DEAE-cellulose, and Sepharose CL-6B chromatography. Sodium dodecyl sulfate polyacrylamide gel electrophoresis of the enzyme showed the presence of a dominant band corresponding to a molecular weight of 80,000. 2. The N-terminal amino acid sequence was determined as follows: Phe-Val-Pro-Glu-Lys5-Glu-Lys-Asp-Pro-Ser10-Tyr-Trp-Arg-Gln-+ ++Gln15-Ala-Gln-Glu- Thr-Leu20-Lys-Asn-Ala-Leu-Lys25-Leu-Gln-Lys-?-Asn-Val-Asn-?- Ala-Lys35-?-Ile-?- Met-Phe40-Leu-(Gly?)-Asp-(Ala/Gly?)-Met45-?-Val-?- (Val/Gly?).

Alkaline Phosphatase↗

PubMed1988

Effect of chemical treatment of poultry feed on survival of Salmonella.

After treatment with a chemical preservative [Myco Curb (Kemin Industries, Des Moines, IA) at .25, .5, .75, or 1.0%], sterilized commercial poultry feed was contaminated with either Salmonella typhimurium ATCC 6994 or with a strain isolated from commercial broiler carcasses. All treatments resulted in the elimination of detectable Salmonella from heavily contaminated feed within 72 h and from lightly contaminated feed within 24 h. Nonsterilized feed showed similar results. Commercial feed fed to broilers for 56 days and inoculated with Salmonella daily for Days 35 to 56 was treated with the chemical preservative at .5 and 1.0% for the last 7 days. Treatment resulted in a reduction of the number of fecal and intestinal samples positive for Salmonella, demonstrating elimination of Salmonella in the feed by use of the feed preservative.

Animal Feed↗

PubMed1988

Protein kinase activities in the parathyroid gland: proparathyroid hormone, parathyroid hormone and secretory protein-I as substrates for phosphorylation.

We have identified two protein kinase activities in homogenates of bovine parathyroid tissue following fractionation on DEAE columns. One of these is a protein kinase C based upon its requirement for calcium and phosphatidylserine and the other one is probably M kinase. The protein kinase C phosphorylated both proparathyroid hormone and parathyroid hormone but not secretory protein-I (SP-I). Neither N [1-34] or C [35-84] terminal hormonal fragments were phosphorylated, suggesting that the structure of the intact PTH molecule is required for recognition by the enzyme. A second kinase activity behaving like M kinase was also obtained. This activity, which was not separable from a cAMP dependent kinase, was maximal with only 50 mM MgCl2 as cofactor. SP-I was readily phosphorylated by this activity but parathyroid hormone was not.

Animals↗

PubMed1987

Purification and partial amino acid sequencing of rat bone tumor (UMR106) alkaline phosphatase.

Cultured rat osteosarcoma (UMR106) alkaline phosphatase was purified to apparent homogeneity by sequential application of polyclonal antibody affinity, DEAE-cellulose, and Sepharose CL-6B chromatography. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the enzyme preparation treated with sodium dodecyl sulfate and mercaptoethanol showed the presence of a dominant band (using silver staining) corresponding to a molecular weight of 80,000. The amino acid composition was similar to those of various alkaline phosphatases. The N-terminal amino acid sequence was determined as follows: Phe-Val-Pro-Glu-Lys-Glu-Lys- Asp-Pro-Ser-Tyr-Trp-Arg-Gln-Gln-Ala-Gln-Glu-Thr-Leu- Lys-Asn-Ala-Leu-Lys-?-Gln-Lys-?-Asn-Val-Asn-Ala-Lys.

Alkaline Phosphatase↗

PubMed1987

Purification and partial amino acid sequencing of bovine kidney alkaline phosphatase.

Bovine kidney alkaline phosphatase (ALPase) was purified by the sequential application of monoclonal anti-bovine cartilage ALPase affinity, DEAE-cellulose, and Sepharose CL-6B chromatography. Sodium dodecyl sulfate-polyacrylamide-gel electrophoresis showed the presence of a single band corresponding to a molecular weight of 80,000. The N-terminal amino acid sequence of bovine kidney alkaline phosphatase was determined as follows: Leu-Val-Pro-Glu-Lys-Asp-Pro-?-Tyr-Trp-Arg-Asp-Gln-Ala-Gln.

Alkaline Phosphatase↗

PubMed1987