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Biomedical subjects

M Kanda

Publications and source records attributed to M Kanda.

At least 181 records · Page 10Linked to original sources
PubMed1984

Growth hormone releasing factors in the brain and the gut: chemistry, actions, and localization.

Within the physiological range of other known releasing factors, human pancreatic tumor growth hormone releasing factor (hpGRF) is specific for GH release. Data concerning hpGRF action on cAMP and GH are consistent with the concept of cAMP acting as a second messenger for this releasing factor. hpGRF-stimulated GH release is Ca++ dependent. Exogenous hpGRF40 does not alter the interdigestive gastric motility or secretion of gastrin and motilin in dogs, while large doses of hpGRF stimulate somatostatin release into the hepatic portal blood of the rat. Significant GRF activity as determined by a rat pituitary perifusion system is confined within the median eminence and the arcuate nucleus, though detectable but insignificant GRF activity is present in other area of the hypothalamus and cortex in the rat. GRF activity is present in the ovine brain as well as in the gut. Both tissues contain large (between 4000-5000 daltons) and small (but possibly larger than 1000 daltons) m.w. GRF materials. GRF appears to be structurally different between species and more than one GRF may be present within the same species. One of the ovine brain peptides with GH-releasing activity was partially characterized as His-Ser-Asp-Gly-Ile-Phe-Thr-Asp-Ser-Tyr- Lys-Arg-Try-Asn-Lys-Glu-Met- Ala-Lys--which is similar to rat GRF and porcine VIP having His at the N-terminus. Another peptide with GRF activity which eluted earlier on reverse phase HPLC and later on cation exchange chromatography has also been obtained in a pure form.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-3-isobutylxanthine↗
PubMed1984

A comparative study of sulfhydryl groups required for the catalytic activity of gramicidin S synthetase and isoleucyl tRNA synthetase.

The sulfhydryl groups required for the catalytic activity of gramicidin S synthetase of Bacillus brevis and Escherichia coli isoleucyl tRNA synthetase were compared. In gramicidin S synthetase 2(GS 2), about four sulfhydryl groups react rapidly with 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) or N-ethylmaleimide (NEM), and are essential for gramicidin S formation in the presence of gramicidin S synthetase 1 (GS 1). These sulfhydryl groups are protected against DTNB and NEM reactions by the preincubation of GS 2 with amino acid substrates in the presence of ATP and MgCl2, like the sulfhydryl groups that react rapidly with DTNB or NEM and are required for the catalytic activity of GS 1 and isoleucyl tRNA synthetase. In GS 2, GS 1, and isoleucyl tRNA synthetase, the sulfhydryl group that reacts rapidly with NEM and is required for the catalytic activity is involved in the amino acid binding as a thioester. In isoleucyl tRNA synthetase, it is suggested that isoleucine may be transferred from the isoleucine thioester enzyme complex to tRNA by a mechanism similar to that proposed for gramicidin S synthetase.

Amino Acid Isomerases↗
PubMed1984

On the histogenesis of experimental pancreatic endocrine tumors. An immunocytochemical and electron microscopical study.

In order to identify the early stage of the development of experimental pancreatic endocrine tumors, Wistar rats were treated with streptozotocin and nicotinamide. One to 11 months after the treatment, the pancreata were examined for neoplastic lesions, using immunocytochemistry and electronmicroscopy. The earliest changes consisted of focal adenomatous proliferation of small ducts, occasionally including endocrine cell clusters. They occurred in the same frequency throughout the whole period examined, regardless whether the pancreata contained tumors or not, and were also present, though in lower numbers, in controls. Immunocytochemistry revealed no true budding off of endocrine cells from ductular epithelium. Thus the histogenetic relationship of the ductal proliferations to the endocrine tumors remains unclear. The earliest tumors were recognized at the fourth month. At the eleventh month 31% of the animals beared tumors. Insulin-positive cells predominated in the tumors, followed by somatostatin-, glucagon- and PP-positive cells. The multihormonal appearance of the neoplasmas is well comparable with the findings in human insulinomas.

Adenoma↗
PubMed1984

Siblings with carbamyl phosphate synthetase I deficiency.

This paper concerns with two autopsied cases of siblings who died from cerebral disturbances. In these patients hyperammonemia developed in the neonatal phase due to carbamyl phosphate synthetase I (CPS I) deficiency. The patient in Case 1 was admitted 2 days after birth because of oliguria and vomiting. Hyperammonemia developed and she died on the 43rd day. In Case 2 hyperammonemia developed from the 2nd day after birth and she expired on the 42nd day. In both cases the diagnosis of CPS I deficiency was established from autopsy findings of the liver.

Amino Acid Metabolism, Inborn Errors↗
PubMed1984

How to identify the Yakuza, Japanese racketeers--their sociology, criminology and physical characteristics.

International crimes such as smuggling and business fraud are increasing. It is possible that members of the Yakuza (Japanese racketeers or gangsters) may be involved in these criminal activities. The Yakuza is one of the best organized criminal groups in the world. It assumes a family-like form with fictitious kinship ties while making a living through organized crime. The sociological and criminological background of the Yakuza and their physical characteristics namely tattooing, digital amputation, and penile spheres are described and discussed so that the Yakuza can be identified even by foreign forensic pathologists.

Adolescent↗
PubMed1984

Regeneration of myocardial cells. Observation in aneurysmectomized ventricular wall.

A small necrotic focus with regeneration of myocardial cells in an aneurysmectomized ventricular wall was observed in a 46-year-old man. Marginating the area of necrosis were myocardial cells with mitosis, with frequent multinucleated and binucleated cells. In the area of necrosis, there was a proliferation of many round, oval to polygonal cells with a high mitotic activity. These cells had eosinophilic granular cytoplasm and one prominent nucleus. Some cells were solitary while others clustered in and around the damaged myocardial fibers. Some cells formed a syncytium and were attached to the perimysial tubes with protoplasmic extensions. These proliferated cells are believed to be a single-cell line and to originate from the damaged myocardial cells. This observation suggests that human myocardial cells may regenerate continuously from surviving myocardial cells and proliferate discontinuously.

Coronary Disease↗
PubMed1983

The estimation of the time of death by non-protein nitrogen (NPN) in cadaveric materials. Report 3: multiple regression analysis of NPN values in human cadaveric materials.

The non-protein nitrogen (NPN) values in brain, lung, liver, and kidney in 79 autopsy cases were determined according to the Micro-Kjeldahl Nessler method. Multiple regression analysis of the data was performed with every possible combination of the time of death and the NPN values in the tissues. The brain NPN showed the best correlation with the postmortem time (r = 0.673), whereas the other correlations were less satisfactory (lung r = 0.422, liver r = 0.397, and kidney r = 0.379, respectively). However, multiple combinations of each tissue NPN value proved to give better correlation coefficients and smaller errors of the estimated time of death. The practical significance of the tissue NPN as a postmortem biochemical indicator of the time of death and the multiple regression analysis of such indicators were extensively discussed in this report.

Adolescent↗
PubMed1983

Transfer of D-phenylalanine from gramicidin S synthetase 1 to gramicidin S synthetase 2 in gramicidin S synthesis.

The transfer of phenylalanine from gramicidin S synthetase 1 (GS 1) to gramicidin S synthetase 2 (GS 2) was studied by the use of combinations of wild-type GS 1 with various GS 2s from a wild strain and gramicidin S non-producing mutant strains of Bacillus brevis Nagano. The combinations of mutant GS 2s lacking 4'-phosphopantetheine (from BI-4, C-3, E-1, and E-2) did not transfer D-phenylalanine from GS 1, although they could activate all the constituent amino acids. Other mutant GS 2s containing 4'-phosphopantetheine, except GS 2 from BII-3 (proline-activation lacking) accepted D-phenylalanine from intact GS 1. To ascertain more directly whether 4'-phosphopantetheine is involved in the transfer of D-phenylalanine from GS 1 to GS 2, pepsin digests of GS 2 that accepted [14C]phenylalanine were analyzed by Sephadex G-50 column chromatography and thin-layer chromatography (TLC). Radioactivity of [14C]phenylalanine was always associated with a peptide containing 4'-phosphopantetheine. Furthermore, the position of radioactivity was distinct from the position of 4'-phosphopantetheine on TLC after alkaline treatment or performic acid oxidation of the digests.

Amino Acid Isomerases↗
PubMed1982

Evidence for a single multifunctional polypeptide chain on gramicidin S synthetase 2 obtained from a wild strain and mutant strains of Bacillus brevis.

The structures of the gramicidin S synthetase 2 s (GS 2, heavy enzyme) from a wild strain and mutant strains of Bacillus brevis have been studied by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). The GS 2s used were obtained from a wild strain and group IV of mutant strains (BII-3, BI-3, BI-9) which lacked one specific amino acid activating activity. SDS polyacrylamide gel electrophoresis of GS 2 bound to a radioactive substrate showed that: first, in the case of the wild enzyme, the radioactivity of the substrate amino acid was detected only in the polypeptide with a molecular weight of about 280,000, regardless of the amino acid species used as substrate; secondly, in the case of the mutant enzyme, the radioactivity of the amino acid which could be activated by the enzyme was also associated with the protein band with a molecular weight of about 280,000. Regardless of the enzyme species tested, a pantothenic acid residue was also present in the protein band with a molecular weight of about 280,000. These results suggest that GS 2 is a multifunctional one polypeptide enzyme and the mutant-type GS 2s from BII-3 (proline-lacking), BI-3 (valine-lacking), and BI-9 (leucine-lacking) are also multifunctional enzymes having molecular weights identical to that of the wild-type enzyme.

Amino Acid Isomerases↗
PubMed1982

Essential arginine residue in gramicidin S synthetase 1 of Bacillus brevis.

Phenylalanine activation of gramicidin S synthetase 1 (GS 1) [EC 5.1.1.11] of Bacillus brevis is inhibited by phenylglyoxal. The inactivation of GS 1 by phenylglyoxal obeys pseudo-first-order kinetics and formation of a reversible enzyme-reagent complex prior to modification is indicated. Both ATP and phenylalanine prevent the inactivation by phenylglyoxal. ATP is competitive with phenylglyoxal, whereas phenylalanine is not. In the presence of ATP, one residue of arginine per mol of protein is protected from the modification as determined by amino acid analysis and incorporation of [7-14C]phenylglyoxal. These results indicate that a single arginine residue of GS 1 is essential for phenylalanine activation in binding the phosphate moiety of ATP.

Adenosine Triphosphate↗