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Biomedical subjects

M Hasebe

Publications and source records attributed to M Hasebe.

61 records · Page 4Linked to original sources

Leiomyosarcoma of the transverse colon.

A case report of leiomyosarcoma of the transverse colon was presented in view of its rarity of the occurrence. An extra-colonic, mobile abdominal mass showing a rapid growth with mild tenderness was the principal preoperative findings in the patient. The occurrence of malignant tumors in smooth muscles of the colon, not including the rectum, is extremely rare. In review of the references, about thirty cases have been previously reported.

Colonic Neoplasms↗

Evolution of MADS-box gene induction by FLO/LFY genes.

Some MADS-box genes function as floral homeotic genes. The Arabidopsis LFY gene is a positive regulator of floral homeotic genes, and homologs of the FLO/LFY gene family in other angiosperms and gymnosperms are likely to have a similar function. To investigate the origin of the floral homeotic gene regulatory cascade involving the FLO/LFY gene, FLO/LFY homologs were cloned from a leptosporangiate fern (Ceratopteris richardii), two eusporangiate ferns (Angiopteris lygodiifolia and Botrychium multifidum var. robustum), three fern allies (Psilotum nudum, Equisetum arvense, and Isoetes asiatica), and a moss (Physcomitrella patens). The FLO/LFY gene phylogenetic tree indicates that both duplication and loss of FLO/LFY homologs occurred during the course of vascular plant evolution. The expression patterns of the Ceratopteris LFY genes (CrLFY1 and 2) were assessed. CrLFY1 expression was prominent in tissues including shoot tips and circinate reproductive leaves, but very weak in other tissues examined. Expression of CrLFY2 was also prominent in tissues, including shoot tips and circinate reproductive leaves. These patterns of expression are dissimilar to that of any Ceratopteris MADS-box gene previously reported, suggesting that the induction of MADS-box genes by FLO/LFY is not established at the stage of ferns.

Arabidopsis↗

Characterization of MADS genes in the gymnosperm Gnetum parvifolium and its implication on the evolution of reproductive organs in seed plants.

Gnetales, one of the extant gymnosperm orders, has traditionally been recognized to be most closely related to flowering plants, because the reproductive organ of Gnetales has some morphological characteristics similar to flowering plants. Most recent molecular phylogenetic studies do not support the sister relationship of the Gnetales and flowering plants, but instead support a close relationship between Gnetales and other extant gymnosperms. The MADS genes are transcription factors, some of which are involved in reproductive organ development in flowering plants. To resolve the discrepancy in phylogenetic inferences, and to provide insights into the evolution of reproductive organs in seed plants, four MADS genes (GpMADS1-4) were cloned from Gnetum parvifolium. GpMADS2 is likely to be a pseudogene and the other three genes were characterized. A MADS gene tree based on partial amino acid sequences showed that GpMADS3 is included in the AGL6 group, but the other two genes do not cluster with any previously reported MADS gene. The three GpMADS genes were expressed during the early stage of ovule development in the differentiating nucellus and three envelopes. A comparison of MADS gene expression among conifers, Gnetum, and flowering plants suggests that the comparable reproductive organs in Gnetum and flowering plants evolved in parallel, and is likely to support the homology between the ovule-ovuliferous scale complex of conifers and the Gnetum ovules, including the three envelopes.

Amino Acid Sequence↗

Immediate stimulation of protein metabolism in burned rats by total parenteral nutrition enriched in branched-chain amino acids.

The effects of two kinds of total parenteral nutrition (TPN) on energy and protein metabolism were examined in rats subjected to 15% full-thickness scald burns in the absence of septic complications. One type of TPN was enriched in branched-chain amino acids (BCAAs), especially leucine (45% BCAA content), and the other was conventional TPN (21% BCAA content). Burned rats received isocaloric and isonitrogeneous TPN solutions for 48 hr after resuscitation by saline infusion for 24 hr. Liver and rectus abdominis muscle were removed from the rats at 7, 24, 48, and 72 hr. The concentrations of adenine nucleotides, RNA, protein, glucose-6-phosphate, hepatic glycogen, muscle phosphocreatine, and 3-methylhistidine were determined. Metabolic alterations occurred during the period of saline resuscitation (0-24 hr). At 48 hr the RNA and protein levels were significantly more improved in the BCAA-TPN group than in the conventional TPN group. At 72 hr, however, the results for the two groups were similar in most metabolite levels. Thus, BCAA-TPN enriched in leucine rapidly stimulated protein synthesis in the liver and muscle. This rapid effect may make it useful during the initial nutritional management of severe trauma patients.

Amino Acids, Branched-Chain↗

Metabolic effect of short-term total parenteral nutrition highly enriched with leucine or valine in rats recovering from severe trauma.

The metabolic impact of infusing a large amount of leucine (Leu) or valine (Val) was examined with regard to the corrective effect of total parenteral nutrition (TPN). Rats recovering from severe sepsis received either Leu- or Val-enriched TPN solution for 30 hours. The in vivo behavior of the amino acids administered was explored by a pulse injection of 14C-labeled Leu or Val. The recovery of 14CO2 from Leu increased by 64% in the septic rats of Leu-TPN group (41% of dose; p less than .01), as compared with control rats receiving the same TPN solution, whereas no significant rise in the 14CO2 recovery from Val occurred in the septic rats given Val-TPN (45% of dose) in comparison with the corresponding controls. The enhancement of Leu catabolism to CO2 in the Leu-TPN group was compatible with the alterations of urinary nitrogen excretion, plasma Leu level, and metabolite contents of liver and muscle. The only difference in metabolite levels observed between the two TPN groups was in hepatic total adenine nucleotides. Plasma amino acid levels were largely unaffected by infusion of these TPN solutions highly enriched with branched-chain amino acids (45%), except for an approximately threefold elevation of the Val level in Val-TPN rats. Thus, when administered in a large quantity during such short-term TPN, Leu can exert its metabolic effect without causing an imbalance in plasma amino acids under severe catabolic conditions.

Amino Acids↗

Glutamate in enteral nutrition: can glutamate replace glutamine in supplementation to enteral nutrition in burned rats?

BACKGROUND: Glutamine (GLN) plays many important roles for the enterocytes in health and disease, but no liquid enteral products contain GLN because of its instability. We hypothesized that glutamate (GLU) may replace GLN in supplementation to an enteral diet, and compared the metabolic effect of GLU and GLN on the gut to each other. METHODS: Rats suffering from a 30% burn received an enteral diet containing 30% GLU (m/w to total amino acids; GLU group), 30% GLN (GLN group), or a standard amino acid formula (CTR group). After a 64-hour feeding period, the small intestine and the portal and arterial blood were harvested to observe portal and arterial amino acid levels, and glutaminase activity and glutathione in the jejunal mucosa. In another study, 3H uptake into the mucosal protein was examined after a massive dose injection of 3H-phenylalanine. RESULTS: Alanine, a product of GLN or GLU catabolism, significantly increased in the portal blood of the GLU group compared with the GLN group. In the gut mucosa of the GLU group, 3H uptake into protein and total glutathione were higher than those of other two groups. GLN did not elevate the glutaminase activity. Arterial GLU levels increased in the GLU group, however remained within safety limits. CONCLUSIONS: Enterally delivered GLU may be a preferable fuel for the enterocytes and enhance the mucosal protein synthesis. GLU probably can substitute for GLN in supplementation to an enteral diet regarding many roles GLN plays in the intestinal mucosa under stress situations.

Amino Acids↗