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Biomedical subjects

I Yano

Publications and source records attributed to I Yano.

At least 145 records · Page 8Linked to original sources

Effects of the polysaccharide chain of lipopolysaccharide in an experimental massive hepatic cell necrosis model in the mice.

When a small amount (1 microgram) of lipopolysaccharide (LPS) purified from Salmonella minnesota wild, Salmonella minnesota R60, and Salmonella minnesota R345 was intravenously injected into mice 7 days after heat-killed Propionibacterium acnes was intravenously injected, massive hepatic cell necrosis was induced and most of the mice died within 24 hours. However, when LPS from Salmonella minnesota R5 and Salmonella minnesota R7 and lipid A from Salmonella minnesota R595 were administered, the survival rate was much higher and no histological changes in the liver such as necrosis could be seen in any of the mice. In each of the LPS used in this study, the structure of the polysaccharide chain was different, and it decreased in the following order: Salmonella minnesota wild----Salmonella minnesota R60----Salmonella minnesota R345----Salmonella minnesota R5----Salmonella minnesota R7----Salmonella minnesota R595. This suggested that the polysaccharide chain of LPS played an important role in the induction of massive hepatic cell necrosis in this experimental model.

Animals↗

Structure and molecular species composition of three homologous series of alpha-mycolic acids from Mycobacterium spp.

Three homologous series of alpha-mycolic acids (dicyclopropanoyl acids, monocyclopropanoyl monoenoic acids and dienoic acids) from 16 rapidly growing and 14 slowly growing mycobacteria were separated by argentation thin-layer chromatography and analysed by gas chromatography/mass spectrometry of their trimethylsilyl ether derivatives. Mycobacterial species were separated into five groups. Strains of group A contained similar amounts of even and odd carbon-numbered dienoic acids, with a methyl branch on the odd acids and a C24-alpha-unit, as typified by Mycobacterium fortuitum and M. chitae. Group B strains possessed similar amounts of even carbon-numbered dicyclopropanoyl alpha-mycolic acids and odd carbon-numbered unsaturated acids with C22- and C24-alpha-units, as found in M. phlei and M. diernhoferi. Group C strains contained mainly even carbon-numbered dicyclopropanoyl acids with C22- and C24-alpha-units, as shown by M. vaccae and M. aurum. Group D strains possessed mainly odd carbon-numbered dienoic acids with a methyl branch and a C24-alpha-unit, as seen in M. triviale and M. nonchromogenicum. Group E strains had mainly even carbon-numbered dicyclopropanoyl acids with C24- or C26-alpha-units, as found in M. avium and M. tuberculosis. Many rapidly growing mycobacteria also produced alpha'-mycolic acids which were shorter in the length of the main carbon chain but whose alpha-units were the same as those in alpha-mycolic acids from the same species. These alpha'-mycolic acids had either one or two double bonds and showed variations in both their unsaturation and overall size, which may be useful in taxonomic studies.

Carboxylic Acids↗

Dysautoregulation in patients with ruptured aneurysms: cerebral blood flow measurements obtained during surgery by a temperature-controlled thermoelectrical method.

We used a temperature-controlled thermoelectrical method, induced hypotension, and CO2 inhalation to obtain cerebral blood flow (CBF) measurements during surgery for investigation of the state of brain vasoreactivity in subarachnoid hemorrhage patients. The study included 11 patients who underwent 12 operations for ruptured intracranial aneurysms. The CBF data were analyzed to investigate the neurological state, presence or nonpresence of vasospasm, timing of the operation, and outcome of each patient. Autoregulation disturbance, in terms of reaction to hypotension, was consistently seen in patients in poor neurological states, and this disturbance was correlated with poor outcome. This simple monitoring system, used during emergency operations for ruptured aneurysm, was useful in predicting outcome.

Adult↗

[Late occlusion at the anastomosis site of an extended polytetrafluoroethylene (E-PTFE) graft with small caliber].

Recently expanded polytetrafluoroethylene (E-PTFE) graft is often used in arterial bypass for atherosclerosis obliterans. In our series of 38 patients (48 legs) undergoing femoropopliteal bypass with E-PTFE graft of 6mm-caliber, a cumulative patency rate was 40.8% at 36 months after operation and a mean duration of patency was 26.3 months. To clarify the cause of occlusion, the diseased grafts were removed and histopathologically examined. Macroscopically, the E-PTFE graft was occluded by the intimal hyperplasia, so called pannus ingrowth from the recipient artery into the graft. The pannus formation of the graft was more remarkable in the distal than in the proximal site of anastomosis, suggesting the influence of blood flow on its formation. Microscopically, no endothelial cells were observed inside the E-PTFE graft except for the surface of pannus. Thus, less extension of endothelialization was thought to be a cause of late occlusion in E-PTFE grafts. Most desirable is the autologous saphenous vein for femoropopliteal bypass. However, when it is not available, E-PTFE graft with a larger caliber must be used in combination with postoperative anticoagulant therapy.

Arteriosclerosis Obliterans↗

Relationship of fat deposition and intestinal microflora in VMH rats.

The purpose of this study was to investigate the pathophysiology of the intestinal microflora in the mechanism of fat deposition in hypothalamic obese (VMH) rats. Enterococci of VMH rats decreased 2 weeks after bilateral lesions in the ventromedial hypothalamic nuclei, and significantly decreased at 12 weeks after the lesions were made (P less than 0.01). Lactobacilli increased after 1 week after the lesions. Numbers of enterococci were negatively correlated with fat deposition in the parametrium (P less than 0.01), retroperitoneum (P less than 0.01), and liver (P less than 0.05), and also with Lee's index (P less than 0.02). Lactobacilli were positively correlated with serum glucose (P less than 0.01), fat deposition in the parametrium (P less than 0.02), and Lee's index (P less than 0.05). Enterococci probably decrease the intestinal absorption of cholesterol, and lactobacilli facilitate the absorption of hexose in the intestine, so a decrease in enterococci and increase in lactobacilli caused by hypothalamic lesions may accelerate the pathogenesis of obesity in VMH rats.

Adipose Tissue↗

Progressive neurogenic muscle atrophy with fasciculation in mice treated with IDPN.

Spontaneous discharges recorded on the EMG appeared in experimental mice given repeated doses of IDPN according to a time schedule. Spontaneous discharges showing a polyphasic pattern and duration of over 10 ms were considered to be fasciculations. One group of mice, treated with IDPN for 4 weeks became active with an increase in muscle volume 2 months after initiation of experiment; spontaneous discharges were recorded in this group at 3-4 weeks after first IDPN injection and disappeared at 4 months. Histologically, neurogenic muscle atrophy, in terms of group atrophy of muscles, was seen in muscles of mice exhibiting spontaneous discharge patterns. Peripheral nerves showed marked atrophy with degeneration. Dissociation of neurofilaments and other organelles was observed. Axonal swellings, filled with numerous maloriented neurofilaments, were confirmed in the lumbar cord. IDPN given repeatedly to mice at a certain dose causes degeneration of the peripheral nerves and results in neurogenic muscle atrophy.

Action Potentials↗

Direct Colony Thin-Layer Chromatography and Rapid Characterization of Serratia marcescens Mutants Defective in Production of Wetting Agents.

A bacterial mass (ca. 1 mg) was placed directly on a thin-layer chromatography plate and developed shortly in chloroform-methanol (2:1, vol/vol). After being dried, the bacterial mass was developed in chloroform-methanol-5 M ammonia (80:25:4, vol/vol). The obtained chromatogram indicated the characteristic lipid compositions of the bacteria. So, it became possible to examine bacterial colonies at once for the identification of mutants defective in the production of specific lipids.

Journal Article↗

Isolation of mycolic acid-containing glycolipids in Nocardia rubra and their granuloma forming activity in mice.

Three classes of glycolipids (TMM (trehalose monomycolate), TDM (trehalose dimycolate) and GM (glucose mycolate] containing mycolic acids as hydrophobic components were isolated from a strain of Nocardia rubra (Rhodococcus rubrum) and their structures have been partially characterized using infrared spectrometry, gas-liquid chromatography and gas chromatography-mass spectrometry. Acid or alkaline hydrolysis of isolated glycolipids revealed that trehalose was the sole water soluble component in TMM and TDM, while glucose was the hydrophilic component in GM. On the other hand, saturated, monoenoic and dienoic mycolic acids with carbon atoms ranging from C36 to C50 contained constituents of fatty acid moiety at C44. From the analytical results, TMM, TDM and GM were tentatively identified as trehalose monomycolate, trehalose dimycolate and glucose monomycolate, respectively. The mycolic acid composition differed significantly by the glycolipid classes: the highest amount of saturated mycolic acids were detected in TMM and GM, while a significant amount of dienoic mycolic acids have been found in TDM and the cell wall bound lipid fraction (BL). All these three classes of glycolipids containing mycolic acids showed strong granuloma forming activity in lungs and spleen of ICR mice 1 week after intravenous injection of 100 to 500 micrograms glycolipid in W/O/W micelles containing Freund's incomplete adjuvant. These results indicated that glycolipids containing shorter carbon chain mycolic acids ranging C40-50, corresponding to less acyl numbers or monosaccharides such as glucose, can also produce foreign body-type granuloma in mice without protein antigens.

Animals↗

Analysis of fatty acid composition of Candida species by gas-liquid chromatography using a polar column.

The fatty acid composition of representative Candida species was examined by gas-liquid chromatography (GLC) using a polar column. The major fatty acids were C14:0, C16:0, C18:0 saturated, C16:1 and C18:1 monoenoic series, with or without C18 polyunsaturated acids (C18:2 and C18:3). In Torulopsis glabrata and Saccharomyces cerevisiae the C18:2 and C18:3 acids were not found, but the C10:0 and C12:0 acids were detected in S. cerevisiae. These results indicated that the Candida genus could be distinguished from Torulopsis and Saccharomyces genera by GLC analysis of fatty acids. Quantitative differences in the fatty acid composition between cells grown at high temperature (37 degrees C) and low temperature (25 degrees C) were found generally in Candida species, and the amounts of C18 polyunsaturated acids (C18:2 and C18:3) increased in the cells grown at 25 degrees C. Each Candida species showed a characteristic profile in fatty acid composition. Determination of the cellular fatty acid composition in Candida species is likely to be useful for the grouping or chemotaxonomy of newer isolates of Candida species.

Candida↗