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Biomedical subjects

H Kubo

Publications and source records attributed to H Kubo.

At least 217 records · Page 12Linked to original sources
PubMed1993

Characterization of neutral glycosphingolipids in human cataractous lens.

Neutral glycosphingolipids were purified from human senile cataractous lenses by a combination of solvent extraction, Folch's partition, acetylation, and column chromatography using DEAE-Sephadex and Iatrobeads. Six major glycosphingolipids (A-F) from monohexosylceramide to pentahexosylceramide were identified by sugar composition analysis, methylation analysis, secondary ion-mass spectrometry, glycosidase digestion, and chromium trioxide oxidation. Their structures suggested that they were closely related in their metabolism: their sugar chains were in sequence and their ceramide moieties were similarly composed, namely C16:0 and C24:1 constituted most of the fatty acids, and long-chain base components were mostly C18-dihydrosphingosine with a small portion of C18-sphingosine. The sugar chains implied two pathways branching from lactosylceramide: one to globotriaosylceramide and the other to lactotriaosylceramide, which leads to the production of Le(x) glycolipid via neolacto type 2 core chain.

Amino Acid Sequence↗
PubMed1993

C-type natriuretic peptide (CNP) is the major natriuretic peptide in human cerebrospinal fluid.

In order to investigate whether C-type natriuretic peptide (CNP) is present in human cerebrospinal fluid (CSF), we measured CNP-like immunoreactivity (-LI) in human CSF by specific radioimmunoassay (RIA) for CNP. We also measured atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) concentrations in human CSF. ANP-LI, BNP-LI, and CNP-LI concentrations of CSF collected from fifteen patients without neurological disorders were 0.20 +/- 0.13, 0.27 +/- 0.10, and 2.13 +/- 0.27 fmol/ml (mean +/- S.D.), respectively. In fifteen patients with neurological disorders, ANP-LI, BNP-LI, and CNP-LI concentrations in CSF were 0.21 +/- 0.18, 0.33 +/- 0.19, and 2.09 +/- 0.82 fmol/ml, respectively. Although ANP-LI and BNP-LI concentrations in plasma were much higher than those in CSF, CNP-LI was undetectable in plasma (less than 0.2 fmol/ml). These results demonstrate that three natriuretic peptides are present in CSF and that CNP is the major natriuretic peptide in human CSF. These results suggest that CNP in CSF is originated from and play important roles in the central nervous system.

Adult↗
PubMed1993

[Angiogenesis on encephalo-myo-synangiosis. The effect of basic fibroblast growth factor].

Moyamoya disease is characterized occlusion of Willis' artery ring and abnormal "moyamoya" vessels. By supplying sufficient blood flow to the distal area of the stenosis or occlusion, ischemic symptom could be improved and the risk of the hemorrhage are lessen. Encephalo-Myo-Synangiosis (EMS) can increase the blood supply from external carotid artery to the ischemic area just put the temporal muscle on the brain surface. A kind of growth factor are thought to be exist around the brain of the Moyamoya disease patient. Basic fibroblast growth factor (bFGF) contribute angiogenesis in vitro and in vivo. This effect is considered to grow tumors and many experiments are done to use it for therapy by blocking this effect. Few trials are done to utilize the angiogenetic effect for therapy. We studied the effect of the bFGF on angiogenesis after EMS by using rats. We operated EMS on 10 male SDrats. 0.1 microgram of the bFGF was poured on 5 rats between the brain and muscle. On the other 5 rats just saline was poured. One week after rats were sacrificed, new vessels were observed with light microscope and scanning electron microscope. Molding models were also observed. bFGF group grew larger new vessels between the brain and muscle than non bFGF group. On the surface of brain, bFGF had more larger vessels (diameter is over 6 um) and non bFGF group had more small vessels (less than 6 um). Total area of vessel of bFGF group was twice as large as that of non bFGF group. On molding models many closed end of vessels were seen and they were thought to be the growing vessels. In molding models, bFGF group also has larger vessels than non bFGF group. We could prove that bFGF promotes angiogenesis on EMS of the rats, and we also expect that bFGF help the supplying blood flow of the Moyamoya patient.

Animals↗
PubMed1993

The structural barrier of absorptive mucosae: site difference of the permeability of fluorescein isothiocyanate-labelled dextran in rabbits.

The permeability of fluorescein isothiocyanate-labelled dextran (FD, M.W. 4400-71,200) across nasal, buccal, duodenal, jejunal, ileal, colonic, and rectal mucosae excised from rabbits has been measured to estimate the structural barrier of absorptive mucosae using Ussing-type diffusion chambers. The permeability coefficient of FD in all these mucosae decreased with increasing molecular weight. The rank order of FD permeability did not always correlate with the electrical resistance of the mucosae. Among components of the small intestine (duodenum, jejunum, ileum) and the large intestine (colon, rectum), however, the rank order of FD permeability corresponded to the magnitude of the electrical resistance in each instance; the upper colonic mucosa showed the highest permeability, especially in FD of low molecular weight, and permeability of the rectal mucosa was lowest except for the duodenal mucosa. The nasal mucosa showed the lowest electrical resistance and the highest permeability of those studied, suggesting that it has a leaky structural barrier.

Animals↗
PubMed1993

Fusogenic properties of uncleaved spike protein of murine coronavirus JHMV.

We have tested the fusogenic properties of cleaved and uncleaved spike (S) protein of murine coronavirus (MCV) JHMV variant cl-2 by expressing the S protein by recombinant vaccinia viruses (RVVs). The amino acid sequence of the putative cleavage site of cl-2 S protein, Arg-Arg-Ala-Arg-Arg, was replaced by Arg-Thr-Ala-Leu-Glu by in vitro mutagenesis of cl-2 S gene. The RVVs having cl-2 S gene [RVV t(+)] or mutated cl-2 S gene [RVV t(-)] were tested for their ability to induce fusion as well as cleavability in DBT cells. After inoculation with RVV t(+) onto DBT cells, the fusion formation was first observed at 8 h postinoculation (p.i.) and spread throughout the whole culture by 24 h. In cells infected with RVV t(-), fusion appeared by 2 h and most of cells were fused by 30 h p.i. The S protein and its cleavage products were detected in DBT cells expressing wild type S protein. However, no cleavage products of the S protein were detected in RVV t(-) infected cells producing mutated S protein, even though fusion was clearly visible. These results suggest that the cleavage event of JHMV-S protein of MCV is not a prerequisite for fusion formation, but that it enhances fusion.

Amino Acid Sequence↗
PubMed1993

Deletion detection for diagnosis of Duchenne muscular dystrophy in the Japanese population--comparison between the polymerase chain reaction and the Southern blot analysis.

We compared the efficacy of the multiplex PCR with that of the cDNA analysis for detection of deletions of the DMD gene in the Japanese patients. Thirty males with DMD from 27 Japanese families were studied by the multiplex PCR, and 24 of them were also investigated by Southern blot analysis. We used five dystrophin cDNA probes for deletion analysis. A total of 19 regions were amplified by the PCR to detect deletions, 9 regions by the method of Chamberlain et al. and another 10 regions by the method of Beggs et al. Deletions were detected in 14 (52%) out of 27 DMD families by the PCR. Southern blot analysis detected deletions in 14 (64%) out of 22 families. Thirteen (93%) of the 14 DMD families with deletions detected by Southern blotting were also confirmed by the multiplex PCR. Provided care is taken in cases where the deletion is limited to a single exon, the multiplex PCR appears to be an efficient and useful alternative to conventional Southern blot analysis for detecting deletions during the prenatal and postnatal diagnosis of DMD.

Asian People↗
PubMed1993

Non-plasmalemmal localisation of the major ganglioside in sea urchin eggs.

M5 ganglioside (NeuGc alpha 2-6Glc beta 1-1'Cer) is the predominant glycosphingolipid in sea urchin eggs. Distribution of M5 ganglioside was studied in unfertilised and fertilised eggs of the sea urchin Hemicentrotus pulcherrimus by indirect immunofluorescence microscopy. In the cortices of unfertilised eggs, anti-M5 antibody strongly stained the submembranous, polygonal and tubular network of endoplasmic reticulum that was revealed by a membrane-staining dye, DiIC18(3). In addition to the cortical network of endoplasmic reticulum, at least two morphologically distinct vesicles were positive to the antibody. In the cortices isolated from fertilised eggs 30 min after insemination, the antibody stained only a similar network of endoplasmic reticulum, presumably the one reconstructed 5-10 min after fertilisation. During mitosis the endoplasmic reticulum is known to aggregate within the asters of the mitotic apparatus. Indeed, the antibody stained the asters and (more strongly) the vesicular components attaching to the periphery of the mitotic apparatus.

Animals↗
PubMed1993

Kinetic analysis of molecular interconversion of immunosuppressant FK506 by high-performance liquid chromatography.

High-performance liquid chromatography of FK506, a macrolide immunosuppressant, was performed on a reversed-phase column. The peak was broad with the column kept at room temperature, which was accounted for by slow interconversion between the two forms of FK506. With the use of a heated column, a sharp peak was observed because of the rapid interconversion at high temperature. When the column was cooled to 0 degree C, two sharp peaks were observed because essentially no interconversion occurred at 0 degree C during elution. Analysis of the chromatograms obtained at various eluant flow rates indicated that the conversion of the two forms follows first-order kinetics, and the apparent activation energies for the conversions were calculated. The interconvertibility between the two molecular forms may be related to the immunosuppressive activity.

Chromatography, High Pressure Liquid↗
PubMed1993

Expression of the S1 and S2 subunits of murine coronavirus JHMV spike protein by a vaccinia virus transient expression system.

The spike (S) protein of murine coronavirus JHMV, variant cl-2, comprises two polypeptides, N-terminal S1 (with an N-terminal signal peptide) and C-terminal S2 (with a C-terminal transmembrane domain). In order to express these subunits, we constructed three different vaccinia virus transfer vectors (VV-TVs) containing cDNAs encoding the S1 protein without a transmembrane domain (pSFS1utt), the S1 protein with a C-terminal transmembrane domain derived from S2 (pSFS1tmd) or the S2 protein with an N-terminal signal peptide derived from S1 (pSFssS2). The S1 and S2 proteins were expressed in DBT cells by infection with vaccinia virus and transfection of these VV-TVs. In cells transfected with the pSFS1utt and pSFS1tmd, 96K and 106K proteins, respectively, were detected by Western blotting. The ssS2 protein expressed by pSFssS2 was 96K, which was slightly larger than the authentic S2 protein. The S1utt and S1tmd proteins were shown by binding studies using a panel of monoclonal antibodies to be antigenically indistinguishable from the authentic S1 protein. The S1tmd and ssS2 proteins were detected on the cell surface by immunofluorescence, whereas the S1utt protein was not. However, when the S1utt protein was expressed together with the ssS2 protein, the S1utt was detected on the cell membrane. This suggested that the S1utt was associated with ssS2 on the cell membrane. These observations indicate that the expressed S1 and S2 proteins associated in a similar manner to the authentic S1 and S2 proteins produced in DBT cells infected with cl-2. However, cell fusion was not observed in cells expressing either S1 or S2 nor in cells coexpressing both S1 and S2, although the whole S protein expressed by VV-TV did induce fusion.

Amino Acid Sequence↗
PubMed1993

Neutralization and fusion inhibition activities of monoclonal antibodies specific for the S1 subunit of the spike protein of neurovirulent murine coronavirus JHMV c1-2 variant.

The cleavage products of the spike (S) protein, the S1 and S2 subunits, of the highly neurovirulent murine coronavirus (MHV) JHMV c1-2 variant were identified by immunoprecipitation of virus-infected cell lysates after treatment with urea and 2-mercaptoethanol. By this method 14 monoclonal antibodies (MAbs) raised against the S protein of the c1-2 variant were revealed to react with the S1 subunit and one with the S2 subunit. These 14 MAbs were classified into the following three groups: (A) MAbs reactive to almost all MHV strains examined, (B) MAbs specific for the JHMV strain and (C) MAbs specific for a large S protein of the JHMV strain. All five MAbs classified in group B showed neutralization activity and four of them also showed fusion inhibition activity. Four of six MAbs in group C showed neutralizing activity to the c1-2 variant but not to the sp-4 variant, and most of them had no fusion inhibition activity. Western blot analyses showed that all of the MAbs, except for no. 2 in group A, failed to react with the denatured S and S1 proteins. All MAbs in groups A and C, with the exception of no. 19 in group A, reacted with the mildly denatured S proteins, whereas none of the MAbs in group B did. These results suggest that MAbs in group B recognized highly conformational epitopes which may be involved in the binding of virions to cellular receptors and the fusion activity of the virus.

Animals↗
PubMed1993

Lethal posttransfusion graft-versus-host disease. Report of four cases.

Four cases of posttransfusion graft-versus-host disease are reported. Three were caused by high-dose transfusion of non-irradiated fresh blood during open-heart surgery and 1 by the contaminated lymphocytes in packed red blood cells transfused for renal injury. In 1 patient, change of HLA type of peripheral lymphocytes was demonstrated.

Aged↗
PubMed1993

Stimulation of pulmonary intravascular macrophages increases microvascular permeability in awake sheep.

The purpose of this study is to determine if stimulation of pulmonary intravascular macrophages (PIMs) increase microvascular permeability in sheep. We infused latex microbeads, 1 micron in diameter, for 1 hr continuously and analysed lung hemodynamic and lymph-dynamic changes. More than 70% of latex microbeads in the lung were assigned to PIMs, and caught in their phagosomes as determined by morphological examination. This implies that infused latex microbeads predominantly stimulate PIMs. Pulmonary arterial pressure increased during the infusion period, and returned to baseline after the infusion period. Lung lymph flow increased and remained high while the lymph to plasma protein ratio ultimately increased above baseline. This implies that infusion of latex microbeads increases pulmonary microvascular permeability. The increase in lung lymph protein clearance was blocked completely by pretreatment with indomethacin, but not with a thromboxane synthetase inhibitor (OKY-046). These data indicate that the increase in microvascular permeability is mediated by an arachidonic acid cyclooxygenase metabolites but not by thromboxane. We conclude that PIMs can act as an initiator to increase pulmonary microvascular permeability by releasing arachidonic acid cyclooxygenase metabolites through their stimulation with latex beads.

Animals↗
PubMed1993

Estimation of the functional reserve of the human liver by urinary D-glucaric acid excretion after vitamin C administration.

The excretion of D-glucaric acid in the urine (uGA) correlates with the total liver content of hepatic cytochrome P-450, the metabolism of which depends on adenosine triphosphate (ATP) being produced by intrahepatic cellular mitochondria. Five cases of compensated liver cirrhosis group with less than 0.4 mg/kg/min of the maximum removal rate of indocyanine green (ICGR max), and 5 cases with normal hepatic function (control group), were monitored for uGA before and after P-450 activation induced by administration of 1 g of vitamin-C. Before vitamin-C administration, no differences in uGA excretion were observed comparing the cirrhosis with the control group. After administration of vitamin-C, the excretion of uGA was significantly lower in the cirrhosis group. The measurement of uGA is considered to represent vitamin-C induced activation by P-450, and is a new method for evaluation of the functional reserve of the liver.

Adenosine Triphosphate↗
PubMed1993

[Effect of physical exercise training on graft patency after aortocoronary bypass grafting].

This study evaluated the effect of physical exercise training on graft patency after aortocoronary bypass grafting (ACBG). Patients who underwent ACBG were randomized into the training (17 patients, 43 grafts) and nontraining groups (18 patients, 45 grafts). Tissue plasminogen activator (TPA) antigen, TPA activity, plasminogen activator inhibitor-1 (PAI-1) antigen and PAI-1 activity as fibrinolysis variables, and an angiographic study were performed 2 and 26 weeks after ACBG. Plasma TPA activity increased significantly in the training group, but not in the nontraining group after 24 weeks of training. Plasma PAI-1 antigen and activity decreased significantly in the training group, while PAI-1 levels remained unchanged in the nontraining group. Grafts were patent in 93% (40 of 43) of the training group and 76% (34 of 45) of the nontraining group (p < 0.05). A high plasma concentration of PAI-1 may interfere with the natural thrombolytic process. Exercise training can decrease PAI-1 levels and increase TPA activity after ACBG. Improved fibrinolysis obtained by exercise training may have beneficial effects on graft patency.

Adult↗
PubMed1993

[Effect of sevoflurane on contraction and membrane potentials in canine right ventricular myocytes].

The effects of sevoflurane on contraction and membrane potentials were studied in isolated canine ventricular muscle strips. Sevoflurane depressed electrically-induced contraction in a dose-dependent manner. The inhibitory effect was more pronounced in high-K+ Tyrode solution than in normal Tyrode solution suggesting that sevoflurane inhibits transmembrane Ca2+ influx. In electrophysiological studies, sevoflurane depressed both overshoot and the plateau phase of action potentials. Resting membrane potential was not affected by sevoflurane. We conclude that the depression of myocardial contractility by sevoflurane may be due to block of transmembrane calcium influx.

Action Potentials↗
PubMed1993

[Anesthesia for severely burned patients--23 operations in 8 burned patients].

Severely burned patients require repeated debridement or skin grafting soon after the burn injury until the closure of the injury. We retrospectively examined 23 operations in 8 severely burned patients who had undergone debridement or skin grafting more than twice within 30 days. We classified 23 operations into 1st to 4th categories according to days after the burn injury and compared each group regarding intraoperative fluid balance, hypovolemia and perioperative complications. In the 3rd or 4th operation, mean blood loss and fluid administration were more than those of the 1st or 2nd operation. Respiratory dysfunctions or circulatory complications such as hypotension, oliguria occurred more frequently during or after the 3rd or 4th operation. Since patients are in hyperdynamic and hypercatabolic state at the time of the 3rd or 4th operation patients, they will be easily damaged in the peri-operative period. This study suggests that we should bear in mind, in the anesthetic management of burned patients, that they can be in hyperdynamic state as well as in shock state.

Adult↗
PubMed1993

[Clonal change of HTLV-1 infected lymphocytes before onset of adult T-cell leukemia/lymphoma].

A 73-year-old HTLV-1 infected male developed overt ATL following 3-years observation, and the clonality of HTLV-1 infected cells changed before overt ATL onset. 10 micrograms of DNA, extracted from mononuclear cells was digested with PstI, and the clonal proliferation of HTLV-1 infected cells was examined by Southern blotting with LTR probe. 4 bands were observed 3 years prior to ATL onset, and 2 different bands were detected 2 years and 6 months later. This suggests that in some ATL cases, the clonality of monoclonally proliferated HTLV-1 infected cells may be changeable before overt ATL onset.

Aged↗