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Biomedical subjects

N Kitamura

Publications and source records attributed to N Kitamura.

At least 469 records · Page 26Linked to original sources
PubMed1984

Immunocytochemical distribution of endocrine cells in the gastrointestinal tract of the horse.

Endocrine cells immunoreactive for somatostatin, gastrin, glicentin, glucagon, secretin, cholecystokinin, motilin and neurotensin were identified immunocytochemically in the gastrointestinal mucosa of the horse. Somatostatin-, glicentin- and glucagon-immunoreactive cells were very numerous in the cardiac and fundic regions of the stomach, whereas most gastrin-immunoreactive cells were confined to the pyloric region. Somatostatin-immunoreactive cells also were detected in all portions of the small intestine while gastrin-immunoreactive cells were confined exclusively to the upper portion and glicentin-immunoreactive cells were limited to the lower portions of the small intestine. Secretin-, cholecystokinin- and motilin-immunoreactive cells were observed only in the duodenum, while neurotensin-immunoreactive cells were confined primarily to the ileum. In the large intestine, somatostatin- and glicentin-immunoreactive cells were detected in the colon and rectum. The preferential location of endocrine cells provides additional information for future studies on the physiological roles of gastrointestinal peptides in the gastrointestinal tract of the horse.

Animals↗
PubMed1984

Characterization of the env gene and long terminal repeat of molecularly cloned Friend mink cell focus-inducing virus DNA.

The highly oncogenic erythroleukemia-inducing Friend mink cell focus-inducing (MCF) virus was molecularly cloned in phage lambda gtWES.lambda B, and the DNA sequences of the env gene and the long terminal repeat were determined. The nucleotide sequences of Friend MCF virus and Friend spleen focus-forming virus were quite homologous, supporting the hypothesis that Friend spleen focus-forming virus might be generated via Friend MCF virus from an ecotropic Friend virus mainly by some deletions. Despite their different pathogenicity, the nucleotide sequences of the env gene of Friend MCF virus and Moloney MCF virus were quite homologous, suggesting that the putative parent sequence for the generation of both MCF viruses and the recombinational mechanism for their generation might be the same. We compare the amino acid sequences in lymphoid leukemia-inducing ecotropic Moloney virus and Moloney MCF virus, and erythroblastic leukemia-inducing ecotropic Friend virus, Friend-MCF virus, and Friend spleen focus-forming virus. The Friend MCF virus long terminal repeat was found to be 550 base pairs long. This contained two copies of the 39-base-pair tandem repeat, whereas the spleen focus-forming virus genome contained a single copy of the same sequence.

Animals↗
PubMed1984

Immunocytochemical study of the gastroenteropancreatic endocrine cells of the sheep.

The gastroenteropancreatic (GEP) endocrine cells of the sheep were studied immunocytochemically and their distribution and frequency were determined. Eleven types of endocrine cells were revealed. In the abomasum, somatostatin-, gastrin-, glucagon- and glicentin-immunoreactive cells were detected with the highest frequency in the pyloric region. In the small intestine, somatostatin-, gastrin-, CCK-, motilin-, neurotensin-, secretin-, substance P-, glucagon-, glicentin- and BPP-immunoreactive cells were found and were most numerous in the duodenum except for neurotensin-, glucagon- and glicentin-immunoreactive cells which were more concentrated in the ileum. In the large intestine, somatostatin-, substance P-, glucagon-, glicentin- and BPP-immunoreactive cells were localized with the last three cell types being more concentrated in the rectum. In the pancreas, somatostatin-, glucagon-, glicentin-, BPP- and insulin-immunoreactive cells predominated within the islets and were also scattered in the exocrine portion and rarely detected in duct epithelial cells. The differences between the distribution and frequency of the GEP endocrine cells of the sheep and those of monogastric species are discussed.

Animals↗
PubMed1984

Immunocytochemical study of gastro-entero-pancreatic (GEP) endocrine cells in the vampire bat (Desmodos rotundus).

The distribution and frequency of gastro-entero-pancreatic (GEP) endocrine cells were studied in vampire bats by immunocytochemistry. Moderate numbers of somatostatin- and a few 5-hydroxytryptamine (5-HT)- and glucagon-immunoreactive cells were seen in the fundic cecum of the stomach. Numerous gastrin- and moderate numbers of somatostatin- and 5-HT-immunoreactive cells were found in the pyloric region. Moderate numbers of 5-HT-, somatostatin-, and gastrin-immunoreactive cells also were found in BRUNNER's glands. In addition to the above-mentioned 4 immunoreactive cell types, cells immunoreactive for glicentin, secretin, cholecystokinin (CCK), gastric inhibitory peptide (GIP), and neurotensin were found in the intestine. Numerous insulin-, moderate numbers of somatostatin- and glucagon-, and a few 5-HT-immunoreactive cells were detected in the pancreatic islets with lesser numbers scattered within the exocrine pancreas. Motilin- and pancreatic polypeptide-immunoreactive cells were not observed in this study.

Animals↗
PubMed1983

Molecular events leading to fusiform morphological transformation by partial src deletion mutant of Rous sarcoma virus.

A mutant of the Prague strain of Rous sarcoma virus (RSV) has two deletions near the 5'-terminus of its src gene. The mutant (dl 5) induced fusiform morphological transformation in chick embryo fibroblasts (CEF) in contrast to the round type morphological transformation induced by wild type (wt) RSV. The partially deleted src of dl5 was shown to code for a 52K protein which has tyrosine kinase activity as high as that of p60src. In dl 5-transformed cells, a 36K protein was heavily phosphorylated, while two proteins (MW = 55K and 57K) were dephosphorylated to the same extent as compared with cells transformed by wt RSV. The relative abundance of phosphotyrosine in vinculin was almost the same in both dl 5- and wt RSV-transformed cells after extended passage of dl 5-transformed cells without marked changes in their morphology. On the other hand, the amounts of vinculin and fibronectin in dl 5-transformed cells were twice those in wt RSV-transformed cells, although less than the amounts in uninfected cells. These results suggest that events leading to cellular morphological transformation are neither directly correlated with phosphorylation of the 36K protein, with dephosphorylation of the 55K and 57K proteins, nor with the level of phosphorylation of tyrosine residues in vinculin, but rather are correlated with the amount of vinculin and fibronectin.

Animals↗
PubMed1983

The coupling valve graft: a procedure for double-valve replacement.

Coupling valve grafting, a procedure to enlarge the annulus of the aortic valve and of the mitral valve simultaneously, is described. It consists of extending the J-shaped aortotomy through the middle of the noncoronary cusp into the superior aspect of the left atrium and down the anterior leaflet of the mitral valve. Then the mitral and aortic valves are replaced with a coupling valve graft, a vascular prosthesis attached to two prosthetic valves. This technique seems to be most suitable for patients in whom the valves of both annuli are narrow, as is often seen in aortic and mitral stenosis. Since both valve annuli can be enlarged greatly in this procedure, combinations of prosthetic valve sizes can be freely chosen for the two valves.

Adult↗
PubMed1983

Primary structures of bovine liver low molecular weight kininogen precursors and their two mRNAs.

By using a mixture of synthetic oligodeoxyribonucleotides as a probe, cloned cDNA sequences specific for low molecular weight (LMW) kininogen have been isolated from a cDNA library of bovine liver mRNA sequences. Nucleotide sequence analyses of cloned cDNA inserts have revealed that bovine liver LMW kininogens are encoded by at least two very similar but distinct mRNAs. The corresponding amino acid sequences show that the LMW kininogen precursors of the two types, composed of 436 and 434 amino acid residues, both contain two internally homologous sequences in the amino-terminal portion between a signal peptide and a bradykinin moiety. The two mRNAs exhibit 15 nucleotide substitutions and 6 nucleotide deletions/additions in their protein-coding regions. The replacement of 13 amino acid residues and the deletions/additions of 2 amino acid residues in the two LMW kininogen precursors are all localized within the internally homologous regions, implying that these regions may be biologically significant in relation to the existence of two LMW kininogens. The nucleotide changes in the two mRNAs also occur in the limited portions that principally encode the internally homologous amino acid sequences. This suggests that the mRNAs are transcribed from the same gene to generate two LMW kininogen precursors differing only in the internally homologous sequences.

Amino Acid Sequence↗