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Biomedical subjects

Y Muraki

Publications and source records attributed to Y Muraki.

63 records · Page 4Linked to original sources
PubMed1992

Structural and functional properties of hen egg-white lysozyme deamidated by protein engineering.

The structural and functional properties of lysozymes genetically deamidated at positions 103 (N103D) and 106 (N106D) were studied by a protein engineering technique. The wild-type and mutant lysozymes were expressed in Saccharomyces cerevisiae and purified from the cultivation medium in two steps by cation-exchange chromatography on CM-Toyopearl. The lytic activity of deamidated lysozymes was almost the same as that of wild lysozyme, although the optimal pH of activity was slightly shifted to lower pH by the deamidation. The Gibbs free energy changes of unfolding (delta G) at 20 degrees C for N103D and N106D were almost the same as that of wild-type. On the other hand, the structural flexibility of lysozymes, estimated by protease digestion, was significantly increased by the deamidation. The surface functional properties of deamidated lysozymes were considerably enhanced, compared to those of wild-type lysozyme. These results suggest that structural flexibility is an important governing factor in surface functional properties of proteins, regardless of their structural stability.

Animals↗
PubMed1992

[Anorexia nervosa with neutropenia--response of neutrophils to G-CSF].

A 50-year-old woman with anorexia nervosa was admitted for evaluation of neutropenia (WBC 1,600/microliters). Her bone marrow was gelatinous, and myeloid cells had decreased. Homogeneous substance deposited in the marrow, stained by alcian blue (pH 2.5), indicative of acid mucopolysaccharides. CFU-G and CFU-GM were decreased in number and myeloid pool in the bone marrow also decreased. Anti-neutrophilic antibody was negative. Neutropenia may be related to myeloid hypoplasia, due to increase of acid mucopolysaccharides replacing adipose cells in the bone marrow under long-term mal-nutritional state. Neutrophils markedly increased by administration of rhG-CSF 5.0 micrograms/kg/day for 14 days without the first peak. Serum G-CSF level did not increase (less than 60 pg/ml). It is effective to administer G-CSF to anorexia nervosa with neutropenia.

Anorexia Nervosa↗
PubMed1992

[Clinicopathological study of 6 cases of mantle zone lymphoma].

Clinicopathological analyses of 6 cases of mantle zone lymphoma (MZL) were carried out. The median age of the patients was 62 years with a range of 41 to 71 years and the male-to-female ratio was 1:1. Superficial lymph node (LN) swelling was present only in 2 patients. Giant LN swellings of the mesenteric or inguinal regions were present in 4, and bone marrow involvement by lymphoma cells in 5. Serum protein electrophoresis revealed a monoclonal protein of IgM kappa type in 2 patients. One of these also had polyclonal hypergammaglobulinemia. An immunohistochemical study of 6 patients revealed LN-1-(-)+, LN-2+(-)++, sIgM+, sIgD+, CALLA +/-(-)+, DRC-1+(-)++. The immunohistochemical features of the cases were similar to those of small lymphocytic lymphoma or follicular lymphoma. Only 1 patients out of 6 achieved complete remission. Two patients died, one of pneumonia after chemotherapy and the other of cancer. The others were alive 4 to 100 months after the diagnoses. Although giant LN swelling and bone marrow involvement of lymphoma cells which were refractory to treatments were frequently observed, we consider MZL to be a slowly progressive and low-grade type of non-Hodgkin's lymphoma.

Adult↗
PubMed1991

[Adult T cell lymphoma/leukemia with alopecia, huge tumors of scalp and wide destruction of cerebral bone].

We reported rare manifestations of adult T cell lymphoma/leukemia. Patient was 41 year-old woman who has had progressive alopecia from childhood and developed multiple huge tumors (largest 10 x 15 cm) of scalp and wide destruction of cerebral bone at age of 39. A few abnormal lymphocytes (10%) appeared in the peripheral smear. Surface markers of peripheral lymphocytes showed two populations of CD4+/CD8- and CD4+/CD8+. HTLV-1 proviral DNA was demonstrated in the peripheral lymphocytes. Serum anti-ATLA antibodies was positive (X80). Biopsy of tumor revealed diffuse and large cell type of malignant lymphoma. Magnetic resonance imaging of head showed that tumors lysed the bone and invaded into cerebral regions. She was treated with CHOP regimen and irradiation, resulting of decreased tumor size and population of CD4+/CD8+.

Adult↗
PubMed1981

Effects of chlorinated benzenes of the activities of delta-aminolevulinic acid synthetase and heme oxygenase and on the content of hemoprotein in the liver of rats.

Effects of chlorinated benzenes on the activities of delta-aminolevulinic acid (delta-ALA) synthetase and heme oxygenase, the rate-limiting enzyme in heme biosynthesis and degradation respectively, and on the incorporation of 3H-delta-ALA into hemoprotein in the liver of male rats were investigated. Monochlorobenzene (MCB) and 1,2,4-trichlorobenzene(TRCB) stimulated significantly the activities of above both hepatic enzymes. After a single injection of 200 mg/kg, heme oxygenase activity was enhanced rapidly and sustained markedly for at least 48 hr by MCB treatment, while that was also enhanced but restored nearly to control levels at 48 hr by TRCB. delta-ALA synthetase activity was once decreased at 6 hr and restored within 12 hr and then reached peak levels (about 2--3 times to control levels) at 24 hr by MCB or TRCB treatment. However, this activity was sustained for 48 hr by TRCB treatment, whereas returned again to nearly control levels by MCB at 48 hr. Cytochrome P-450 content at 48 hr was significantly decreased by MCB (63% to control), in contrast, increased by TRCB (200% to control). When MCB or TRCB injected once daily throughout the study, biphasic disappearance of radioactivity incorporated into CO-binding particles was shown in control and MCB- or TRCB-treated rats. The half-life of the fast phase was about 8 hr in control and about 6 or 13 hr in MCB- or TRCB-treated rats respectively.

5-Aminolevulinate Synthetase↗