Search PubMed⌕ Search

Biomedical subjects

H Kobayashi

Publications and source records attributed to H Kobayashi.

At least 19 recordsLinked to original sources
PubMed1992

[Expandable metallic stent therapy for SVC syndrome--effects on local venous pressure, vascular diameter, symptoms, and these correlations].

To evaluate the efficacy of Z-stent therapy for SVC syndrome, we studied changes in the pressure, the diameter of stenotic lumen and the symptoms in the cases of SVC syndrome with higher pressure than 30 cmH2O at distal to the stenosis. The symptoms were classified and graded to be scored up. Immediately after the Z-stent placement into the stenotic lesions, the venous pressure distal to the stenosis decreased from 36.0 +/- 3.4 cmH2O to 12.0 +/- 12.0 cmH2O (p < 0.001), the diameter of stenotic lumen increased from 3.3 +/- 3.4 mm to 14.0 +/- 3.4 mm (p < 0.01). According to the remarkable symptomatic improvements the averaged score decreased from 6.7 to 1.3 (p < 0.01). The pressure, the diameter and the symptom scores were highly correlated each other (magnitude of gamma not equal to 0.9). Among two cases with the right atrial pressure increase by 2 cmH2O after the placement one suffered transient cardiac in compensation due to overload by reperfusion. Conclusively, the Z-stent therapy was very effective on the SVC syndrome in reducing abnormally elevated venous pressure due to the stenosis, and relieving the symptoms, while the pressure monitor was necessary.

Aged↗
PubMed1992

[Biological effects of static gradient magnetic field on cultured mammalian cells and combined effects with 60Co gamma-rays].

The biological effects of a static gradient magnetic field and its combined effects with ionizing radiation on FM3A cultured cells were investigated. The magnetic strength of the center of the field was 5.8 x 10(-2) T esla, the mean gradient of the magnetic filed was 0.6 T esla/m. The magnetic field influenced cell cycle. The relative amount of cultured cells in G1 phase decreased for eight hours after exposure. The growth rate of the cells was slowed by about 5%. Following exposure to the magnetic field, the survival rate of cells decreased to about 20% less than that of the non-exposed control. The combined effect of 60Co irradiation with exposure to the magnetic field showed a greater effect than a simple additive one. The combined effect was influenced by the interval between 60Co irradiation and exposure to the magnetic field. The biological effects of the magnetic field may be related to age-dependent cellular damage in the cell cycle, blockage of cell progression in the cell cycle, and increased repair from radiation damage.

Animals↗
PubMed1992

Oscillatory metabolism of Saccharomyces cerevisiae in continuous culture.

Short-period (40-50 min) synchronized metabolic oscillation was found in a continuous culture of yeast Saccharomyces cerevisiae under aerobic conditions at low-dilution rates. During oscillation, many parameters changed cyclically, such as dissolved oxygen concentration, respiration rate, ethanol and acetate concentrations in the culture, glycogen, ATP, NADH, pyruvate and acetate concentrations in the cells. These changes were considered to be associated with glycogen metabolism. When glycogen was degraded, the respiro-fermentative phase was observed, in which ethanol was produced and the respiration rate decreased. In this phase, the levels of intracellular pyruvate and acetate became minimum, ATP became high and intracellular pH at its lowest level. When glycogen metabolism changed from degradation to accumulation, the respiratory phase started, during which ethanol was re-assimilated from the culture and the respiration rate increased. Intracellular pyruvate and acetate became maximum, ATP decreased and the intracellular pH appeared high. These findings may indicate new aspects of the control mechanism of glycogen metabolism and how respiration and ethanol fermentation are regulated together under aerobic conditions.

Aerobiosis↗
PubMed1992

Lymphatic flow in carcinoma of the head of the pancreas.

The lymphatic pathway from the head of the pancreas to the para-aortic lymph nodes was examined on the basis of the frequency of lymph node involvements. Forty-four patients were examined. All patients had extended radical operations. Thirty-one of 44 (70.5%) patients had lymph node involvement. The lymph nodes that had a high metastatic rate included the following: (1) lymph nodes around the common hepatic artery (number 8 lymph node); (2) lymph nodes of the hepatoduodenal ligament (number 12 lymph node); (3) the posterior pancreaticoduodenal lymph node (number 13 lymph node); (4) lymph nodes around the superior mesenteric artery (number 14 lymph node); (5) para-aortic lymph nodes (number 16 lymph node); and (6) the anterior pancreaticoduodenal lymph node (number 17 lymph node). Twenty-eight of these 31 patients had disease in the posterior pancreaticoduodenal lymph node. The patterns of lymph node involvement consisted of four combinations: number 13-number 17, number 13-number 14, number 14-number 16, and number 17-number 8. All of the patients with number 16 nodal involvement had number 14 lymph node metastasis. However, there was no relationship between tumor size and lymph node involvement. Based on these results, the main lymphatic pathway from the head of the pancreas to the para-aortic lymph nodes was thought to be via the lymph nodes around the superior mesenteric artery, assuming that lymphatic flow is anterograde. In addition, this study demonstrates that it is necessary to perform an extensive lymph node dissection, including the para-aortic lymph node, even in patients with small tumors.

Carcinoma, Intraductal, Noninfiltrating↗
PubMed1992

Binding selectivity of rhizoxin, phomopsin A, vinblastine, and ansamitocin P-3 to fungal tubulins: differential interactions of these antimitotic agents with brain and fungal tubulins.

The binding of four potent antimitotic agents, rhizoxin (RZX), phomopsin A (PMS-A), ansamitocin P-3 (ASMP-3), and vinblastine (VLB), to tubulins from RZX-sensitive and -resistant strains of Aspergillus nidulans, Schizosaccharomyces pombe, and Saccharomyces cerevisiae was investigated. Mycelial extracts to which RZX could bind contained beta-tubulin with Asn as the 100th amino acid residue (Asn-100) in all cases, and those without affinity for RZX contained beta-tubulins with either Ile-100 or Val-100. Though PMS-A shares the same binding site as RZX and ASMP-3 on porcine brain tubulin (Asn-100), only ASMP-3 bound Asn-100 fungal tubulins in a competitive manner with respect to RZX. PMS-A and VLB, which strongly bind to porcine brain tubulin, did not bind to any of the fungal mycelial extracts examined. The results indicate differential interactions of these antimitotic agents with brain and fungal tubulins.

Animals↗
PubMed1992

[Endoscopic visualization of luminal organ and great vessels with three dimensional CT scanner. A new trial using volumetric CT].

Thirty cases examined by three dimensions CT scanner (3DCT) were reported. The observation of inner view using 3DCT were performed in 12 large vessels with vascular disorder, 10 pulmonary bronchus with lung cancer and 8 common bile ducts involved obstructive disease. In order to visualize interface of the lumen, a new software which was devekioed by HITACHI MEDICO Inc. and us was brought in. In all cases but one the inner view of the luminal organ was clearly demonstrated as 3D images and it was possible to judge some changes of luminal interface involved by the diseases. The 3DCT endoscopic image might be useful as a new endoscopic technique without fiberscopy.

Aortography↗
PubMed1992

Crystallization and preliminary X-ray diffraction studies of aspartic proteinase from Irpex lacteus.

Crystals of ILAP (Irpex lacteus aspartic proteinase) have been obtained by the hanging drop method using ammonium sulfate as a precipitant. The crystals are monoclinic, space group P2(1) with cell dimensions a = 54.5 A, b = 79.6 A, c = 37.5 A, beta = 96.8 degrees. The crystals are quite stable to X-rays and diffract beyond 1.9 A resolution. There is one molecule in the asymmetric unit.

Animals↗
PubMed1992

Structure of the D-mannan of the pathogenic yeast, Candida stellatoidea ATCC 20408 (type II) strain, in comparison with that of C. stellatoidea ATCC 36232 (type I) strain.

Acid treatment of the cell-wall D-mannas of Candida stellatoidea strains ATCC 36232 (Type I, A3 strain) and ATCC 20408 (Type II, A2 strain) gave (1----2)-linked beta-D-manno-oligosaccharides (dp 2-5), whereas treatment with alkali gave the (1----2)-linked alpha-D-mannobiose. Conventional acetolysis of the acid- and alkali-treated D-mannan of the A3 strain gave oligosaccharides consisting of (1----2)- and (1----3)-linked alpha-D-mannopyranose residues, similar to those of Candida albicans serotype B strain. Mild acetolysis of the acid- and alkali-treated D-mannan of the A2 strain gave higher oligosaccharides that were digested by the Arthrobacter GJM-1 strain exo-alpha-D-mannosidase. The results of 1H- and 13C-NMR analyses indicated this D-mannan to contain branches with the following structures: beta-D-Manp-(1----2)-alpha-D-Manp-(1----2)-alpha-D-Manp++ +-(1----2)-alpha-D-Manp- (1----2)-D-Man, beta-D-Manp-(1----2)-beta-D-Manp-(1----2)-alpha-D-Manp -(1----2)- alpha-D-Manp-(1----2)-D-Man, and beta-D-Manp-(1----2)-beta-D-Manp-(1----2)-beta- D-Manp-(1----2)-alpha-D-Manp-(1----2)-alpha-D-Manp-(1- ---2)-alpha-D-Manp- (1----2)-D-Man, in common with the D-mannans of C. albicans serotype A strains.

Agglutination Tests↗
PubMed1992

Inhibition of in vitro ovarian cancer cell invasion by modulation of urokinase-type plasminogen activator and cathepsin B.

HOC-I ovarian cancer cells express the single-chain form of the urokinase-type plasminogen activator (uPA) and cathepsin B (cath B) on their cell surface. The significance of the expression of cell surface uPA/cath B activity to the invasive potential was examined by preincubating with uPA/cath B-modulating agents in in vitro invasion assay. The anti-uPA monoclonal antibody 394 effectively inhibited invasion in a dose-dependent manner. On the contrary, anti-cath B antibody did not affect the invasive potential of the cells. E-64, a specific inhibitor for cysteine proteases, blocked invasion as effectively as monoclonal antibody 394. The data reveal that the uPA and cysteine proteases contribute significantly to the invasive capacity of the cells. We suggest that the cysteine proteases facilitate the action of uPA, possibly by activating proenzyme uPA produced by cancer cells. Evidence for the role of a cathepsin-uPA activation cascade in HOC-I cell invasion is provided.

Cathepsin B↗
PubMed1992

Zinc hydroxide stimulates superoxide production by rat alveolar macrophages.

The effect of zinc hydroxide on superoxide (O2-) production by rat alveolar macrophages was determined by chemiluminescence and by cytochrome c reduction. Zinc ions had no effect on the chemiluminescence of unstimulated alveolar macrophages. By contrast, zinc hydroxide (ZnOH2), a neutralized form of zinc ions, increased the chemiluminescence level and O2- release. Increased O2- release was inhibited by pertussis toxin, isoquinoline sulfonamide and pretreatment with EGTA. These findings indicate that zinc hydroxide formation from zinc compounds can stimulate the O2- production by alveolar macrophages by receptor-mediated and Ca(2+)-dependent process.

Animals↗
PubMed1992

Sequential nuclear magnetic resonance assignment of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of the pathogenic yeast Candida albicans NIH B-792 strain.

The H-1 and H-2 signals of beta-1,2-linked mannooligosaccharides isolated from the phosphomannan of Candida albicans NIH B-792 strain by mild acid hydrolysis were assigned by a sequential NMR assignment method that combines two-dimensional 1H-1H correlated spectroscopy (COSY) and two-dimensional nuclear Overhauser enhancement and exchange spectroscopy (NOESY). The results indicated that the H-1 and H-2 of each beta-1,2-linked mannopyranose unit show largely different signals compared with those of the alpha-linked ones and that the correlation between linkages and signals could not be explained by a conventional additivity rule. Furthermore, a regular proportional downfield shift of the H-1 signal was observed in the order of the mannose unit from the reducing terminal except those of the reducing and nonreducing terminal positions. Although the 1H NMR spectra of these oligosaccharides were complicated due to the presence of a large portion of the beta-anomer from the reducing terminal mannose unit, reduction of the oligosaccharides with NaBH4 to the corresponding alcohols gave simple and more readily interpretable 1H NMR spectra. Unexpectedly, however, a shift of H-1 signals by this reduction occurred not only on the second mannose unit but also on the third and fourth mannose units from the modified reducing terminal group of each oligosaccharide alcohol. This result indicates that the reducing terminal mannose unit is able to affect up to the fourth mannose unit from the reducing terminal. The presence of a long-distance interresidue NOE also suggests that the beta-1,2-linked mannooligosaccharides have a compactly folded conformation in solution.

Alcohols↗
PubMed1992

Heparin cofactor II deficiency in the elderly: comparison with antithrombin III.

We investigated heparin cofactor II (HC II) levels and their relationship to other haemostatic factors in the elderly in comparison with antithrombin III (AT III). We measured plasma HC II activity levels in 166 subjects aged from 61 to 99 years using a chromogenic method. HC II levels (94.4 +/- 18.5%) in the healthy elderly subjects were significantly (p less than 0.001) lower than in 40 healthy adult controls under 60 years of age (mean age: 51.5 years; 111.6 +/- 21.2%). HC II levels in the elderly subjects decreased further with age (r = 0.308, p less than 0.001) and the extent of the decrease was more marked than that for AT III (r = 0.179, p less than 0.05). There was no significant sex difference in HC II levels in the elderly. HC II levels correlated significantly with AT III levels and with acute phase reactants including sialic acid, fibrinogen, and PAI-1. HC II levels also correlated with factor VII, plasminogen, alpha 2-plasmin inhibitor, serum lipid, pseudocholinesterase, and albumin levels. These correlations were also found for AT III except active PAI-1 and tPA-PAI-1 complexes, but the correlations with acute phase reactants were stronger for HC II than AT III. We divided 154 elderly subjects into 4 groups by their pseudocholinesterase and albumin levels to estimate the effect of nutritional status on antithrombin activity in the elderly. HC II levels were normal in the elderly subjects with a good nutritional state (103 +/- 18%), but were significantly decreased in those with malnutrition (85 +/- 15%, p less than 0.001). AT III levels also showed the same tendency. These results indicate a decrease in the reserve capacity to inhibit thrombin generation at sites of atherosclerosis in response to trigger events. The deficiency of two major antithrombin factors in the elderly may indicate a tendency to thrombosis, especially in individuals with malnutrition. When considering the clinical significance of HC II, several other parameters, including age, nutritional status, hepatic synthetic ability, and the presence or absence of acute phase reaction should also be assessed.

Acute-Phase Proteins↗
PubMed1992

Molecular cloning of cDNAs for human fibroblast nucleotide pyrophosphatase.

Nucleotide pyrophosphatase (NPPase) activity is markedly elevated in cultured skin fibroblasts from patients of Lowe's syndrome. cDNA clones encoding the NPPase were isolated using synthetic oligonucleotide probes designed on the basis of partial amino acid sequence of the enzyme purified from human placenta. The complete sequences of these clones yielded a merged sequence of 3508 bases. The polypeptide chain of the enzyme was deduced to comprise 873 amino acids with a calculated molecular weight of 99,703 and had the characteristics of a class II transmembrane protein. Ten potential N-glycosylation sites were detected in the protein. RNA blot analysis showed that human fibroblasts contain two minor mRNAs of 7.0 and 8.2 kb, respectively, in addition to a major 3.6-kb species that coincides with the merged cDNA in size. A computer search of a nucleotide sequence data-base revealed that plasma cell membrane glycoprotein PC-1, whose function was unknown at the time, is identical with the NPPase. Comparison of the amino acid sequence of the NPPase with the active site sequence of bovine 5'-nucleotide phosphodiesterase allowed the assignment of a putative active site domain to the central region of the COOH-terminal extracellular domain of the NPPase. The gene for human NPPase was localized to chromosome 6 at q22-q23 by in situ hybridization with a fragment of the NPPase cDNA.

Amino Acid Sequence↗
PubMed1992

Preferential consumption of heparin cofactor II in disseminated intravascular coagulation associated with acute promyelocytic leukemia.

We measured plasma heparin cofactor II (HC II) activity in patients with disseminated intravascular coagulation (DIC) due to various underlying diseases together with the levels of antithrombin III (AT III), pseudocholinesterase (a marker of hepatic synthesis), and various haemostatic molecular markers. Both HC II and AT III were decreased in DIC secondary to all the underlying diseases studied, except acute promyelocytic leukemia (APL), when compared with healthy subjects. The lowest HC II and AT III levels was observed in coagulopathy secondary to liver disease, the HC II level in sepsis was the second lowest. In DIC due to APL, the decrease in HC II was not accompanied by a decrease in AT III. Thus, we divided all 124 samples tested into APL and non-APL groups. The HC II level correlated positively with fibrinogen and plasminogen in both the APL and non-APL groups. In the APL group, the HC II level had a significant negative correlation with the thrombin-AT III complex (TAT), fibrinogen/fibrin degradation products, and D-dimer levels as well as the prothrombin time, while AT III showed no correlations with any of the haemostatic parameters. These results suggest that HC II may be consumed preferentially by thrombin in APL patients with DIC, and thus may spare the consumption of AT III. Accordingly, HC II seems to be a superior indicator of DIC than AT III in APL patients. Moreover, replacement therapy with HC II instead of AT III may be useful to treat DIC associated with APL. In the non-APL group, the HC II levels were positively correlated with the levels of AT III and pseudocholinesterase activity. This indicates that plasma HC II levels are closely related not only to consumption coagulopathy but also to hepatic synthetic activity, as is the case for plasma AT III.

Adult↗