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Biomedical subjects

K Matsui

Publications and source records attributed to K Matsui.

At least 739 records · Page 41Linked to original sources
PubMed1980

Environmental temperature, a factor modifying the acute toxicity of organic solvents, heavy metals, and agricultural chemicals.

1500 male mice, previously acclimatized to 8,22 or 38 degrees C, were used to determine the median lethal doses of organic solvents, heavy metals and agricultural chemicals by the Up-and-Down method via several routes of administration. Acute toxicity of benzene, trichloroethylene, mercuric chloride, cadmium chloride, fratol, methylparathion and dieldrin increased markedly at a low temperature of 8 degrees C, as well as at a high temperature of 38 degrees C. Acute toxicity of toluene, copper sulfate and chromium trioxide was only enhanced at a high temperature of 38 degrees C.

Animals↗
PubMed1980

A study of the absorption, circular dichroism and magnetic circular dichroism spectra of a flavin derivative. The pi-electronic structure of 8-amino-8-demethyl-D-riboflavin.

The absorption, CD and MCD spectra of 8-amino-8-demethyl-D-riboflavin, which showed novel spectral properties, were measured in the spectral region from 220 nm to 540 nm and the spectra obtained were analyzed in terms of Gaussian wave number curves (from band I to band X). Semi-empirical calculations of the Pariser-Parr-Pople Hamiltonian were performed to investigate the novel spectral properties and the reactivity at the 5-position. The theoretical results as well as the experimental results showed that the novel spectral properties were a result of amino substitution at the 8-position.

Chemical Phenomena↗
PubMed1980

Vibrational modes of flavin bound to riboflavin binding protein from egg white. Resonance Raman spectra of lumiflavin and 8-substituted riboflavin.

The resonance Raman (RR) spectra of 8-halogenated-riboflavin, 8-demethyl-riboflavin(8-H-RF), 8-amino-riboflavin(8-NH2-RF), 8-methoxy-riboflavin(8-OCH3-RF), lumiflavin, and 3-methyl-lumiflavin were observed. The Raman lines with the highest frequency are at 1624, 1620, and 1615 cm-1 for 8-chloro-riboflavin, 8-bromo-riboflavin, and 8-iodo-riboflavin, respectively. This systematic shift confirms that the 1631 cm-1 line of riboflavin is derived from the benzene part of isoalloxazine. Substitution at the 8-position by an amino or methoxy group, which has a large influence on the electronic structure of isoalloxazine, changes the RR spectrum markedly in comparison with that of 8-halogenated riboflavin. The 1583 cm-1 line of riboflavin, which involves the vibrational displacement of N(5) and C(4a) atoms of isoalloxazine, is shifted to the low frequency side by substitution at the 8-position with an amino or methoxy group. The corresponding line of 8-H-RF, on the contrary, shifts to the high frequency side. The RR spectrum of lumiflavin is very different from that of riboflavin in the range from 1200 to 1300 cm-1. Although the pi-electronic structure is little affected by the substitution at the 10-position, the Raman spectrum of lumiflavin in this region is very sensitive.

Binding Sites↗
PubMed1980

Resonance Raman spectra of semiquinone forms of flavins bound to riboflavin binding protein.

The resonance Raman (RR) spectra of semiquinones of complexes of riboflavin or 8-methoxyriboflavin (8-OCH3-RF) with riboflavin binding protein (RBP) were observed. The RR spectrum of neutral semiquinone of riboflavin-RBP complex in H2O solution has an intense line at 1617 cm-1, not observed for oxidized riboflavin bound to RBP. The line at 1617 cm-1 does not shift in D2O solution. The absorption spectrum of semiquinone of 8-OCH3-RF bound to RBP has maxima at 586, 396, and 344 nm, and the RR spectrum doublet lines at 1623 and 1615 cm-1. In D2O solution, the 1623 cm-1 line does not shift, but the 1615 cm-1 line shifts to 1604 cm-1. The line around 1620 cm-1 for the flavin semiquinone will be useful in the determination of the redox state of flavin.

Binding Sites↗
PubMed1980

Prelymphomatous and lymphomatous changes in splenomegaly of new zealand black mice.

The incidence of splenomegaly was 39.6% in the nontreated group and 41.0% in the treated group, not significantly different between both groups. Thymic lymphoma group shared 27.6%, while the nonthymic lymphoma group 67.9%, significantly different between both. Histological findings of splenomegaly of the nonlymphoma groups were divided into the following 5 types. 1) follicular form, 2) periarterial lymphatic sheath form, 3) red pulp hematopoietic form, 4) marginal zone form, and 5) red pulp reticulosis form. Histology of the spleen in the lymphoma group resembled each form of cases of splenomegaly in the nonlymphoma group. Lymphoma based upon immune abnormality and specific to this kind of mouse in nonthymic lymphoma continuously takes place from prelymphomatous changes in the nonlymphoma group. Splenic origin and role of mariginal zone of nonthymic lymphoma in murine lymphoma is discussed.

Animals↗
PubMed1980

Radioimmunoassay of arginine vasopressin in human plasma and urine, a resin microcolumn method.

A new method was developed for the estimation of arginine vasopressin (AVP) in plasma and urine. Samples were extracted by a microcolumn of resin and assayed radioimmunologically using a highly sensitive antiserum to AVP. Ion-exchange resin, CG-50, H+ form, packed in a small column (diameter 4 mm, height 6 mm), was proved effective to remove the interfering substances and to concentrate the AVP in the sample. The application of 80% acid acetone successive to diluted HCl brought about a consistent recovery of AVP from the resin column. Recoveries were 66.4 +/- 8.5% for plasma and 85.4 +/- 9.7% for urine. In normal subjects plasma AVP levels were 3.9 +/ 0.3 pg/ml (mean +/- S.D.) in ambulatory states, 4.9 +/- ).6 after overnight fast, and 0.4 +/- 0.2 after water lading. High levels of 2.0 +/- 24.2 pg/ml were obtained in patinents with syndrome of inappropriate secretion of ADH (SIADH), low values of 0-1.8 pg/ml in diabetes inipidus. Urinary excretions of AVP were 117.4 +/- 59.4 ng/24/hr (mean +/- S.D.) in normal controls, 191 +/- 177.0/24 hr in SIADH, and 17.0 +/- 12.0/24 hr in diabetes insipidus.

Arginine Vasopressin↗
PubMed1980

[The clinical values fro chemical constituents of blood in normal miniature Shiba goats (author's transl)].

Using the both methods. RaBA-Super System (Rapid Blood Analyzer System), the clinical values for chemical constituents of blood in Shiba goats bred in Stock Farm, University of Tokyo, were determined on the following items: total protein, albumin, TTT, glucose, BUN, total bilirubin, total cholesterol, triglyceride, GOT, GPT, ALP, LDH, CPK, cholinesterase, calcium and inorganic phosphorus. The results obtained were summarized as follows: 1) All items determined were to be analyzed by means of the RaBA-Super System, although the values for total cholesterol, TTT, ALP and CPK varied considerably with individuals. 2) The values of adult female goats were significantly higher than those of young ones in total protein and albumin, and lower in glucose, cholinesterase, ALP and CPK. 3) The values of GPT and BUN of adult female goats in summer were significantly lower than those in winter and autumn. 4) The values for triglyceride and albumin of adult female goats using the RaBA-Super System were inconsistent with those analyzed simultaneously by the manual method, but a significant linear correlation was recognized between the both methods.

Age Factors↗