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Biomedical subjects

H Hashimoto

Publications and source records attributed to H Hashimoto.

At least 541 records · Page 30Linked to original sources
PubMed1996

[Posterior fossa dural arteriovenous fistula with progressive disorder of cerebellar circulation; case report].

A rare case of posterior fossa dural arteriovenous fistula with cerebellar circulation disorder is reported. A 64-year-old male was admitted to a hospital with complaints of nausea, vertigo and mild headache. Computed tomography (CT) and magnetic resonance imaging (MRI) revealed cerebellar infarction. Then, he was sent to our hospital. He had complaints of cerebellar signs and nystagmus. Cerebral angiography showed dural AVF of the posterior fossa and occlusion of the left transverse-sigmoid sinuses. Because his condition deteriorated, embolization of the left middle meningeal artery, ascending pharyngeal artery and occipital artery was performed selectively on August 18. Subsequently, isolation of dural AVF was performed on August 19. After the operation he improved and was able to walk with a stick. Controlled angiography revealed the disappearance of dural AVF. This case suggested that AV shunt is essential for the progression of venous infarction.

Arteriovenous Fistula↗
PubMed1996

[A case of selective IgM deficiency associated with systemic lupus erythematosus].

We report a case of selective IgM deficiency associated with systemic lupus erythematosus (SLE). A 34-year-old female suffering from SLE was admitted with proteinuria and general fatigue. Laboratory findings revealed a very low serum IgM level, almost lower than 12 mg/dl. Renal biopsy findings showed diffuse proliferative lupus nephritis (DPLN). In immunofluorescent microscopy, IgG was the most strongly stained followed by IgA, but IgM staining was only faint. As for the immunophenotype of the T cells, the OKT4/OKT8 ratio was normal. Response to both phytohemagglutinin (PHA) and concanavalin A (ConA) was normal. However, responses of B cells to both pokeweed mitogen (PWM) and Staphylococcus aureus Cowan strain I (SAC) were significantly reduced. Surface IgM-positive B cells were decreased. These results indicate that the patient had B cell dysfunction, involving impairment of B cell differentiation. In this report, we discuss selective IgM deficiency and SLE documented in the literature.

Adult↗
PubMed1996

Fluctuations of the hemodynamic derivatives during left ventricular assistance using oscillated blood flow.

To analyze the autonomic nervous system during left heart bypass with a vibrating flow pump (VFP), fluctuations in hemodynamic derivatives were evaluated by the spectral analysis method using fast fourier transform methodology. After the left pleural cavity was opened through the fourth intercostal space under general anesthesia, a VFP was implanted as the left heart bypass device in chronic animal experiments using 3 healthy adult goats. Hemodynamic parameters with and without VFP assistance were recorded on magnetic tape in awake animals and were analyzed by computer through an analog to digital convertor. Power spectral analysis was performed on a beat-to-beat basis for the evaluation of the fluctuations. During left heart bypass with the VFP, Mayer wave fluctuations were decreased significantly although respiratory waves were not changed significantly. These results suggest that sympathetic nervous system modulation was changed under the influences of the left heart bypass with VFP. By using this analysis methodology, truly physiologic ventricular assistance may be achieved.

Animals↗
PubMed1996

[Difficult tracheal intubation and abnormal response to thiopental in a patient with arthrogryposis multiplex congenita].

Anesthesia was administered for six times to a patient with arthrogryposis multiplex congenita (AMC) at the age of 10 to 17 years. In the first four occasions of anesthesia, difficult tracheal intubation was encountered due to limited neck extension, inadequate mouth opening and the short epiglottis. On the fifth anesthesia, the patient remained conscious even after intravenous injection of thiopental 6.6 mg.kg-1, and enflurane in combination with nitrous oxide was administered to induce anesthesia. During the induction of the sixth anesthesia, excessive oral secretion and severe continued nausea were observed just after intravenous administration of thiopental 5.3 mg.kg-1. These were overcome by intravenous administration of ketamine 2.0 mg.kg-1. Problems such as difficulty in tracheal intubation and abnormal response to thiopental need special attention in patients complicated with AMC, particularly during induction of anesthesia.

Abnormalities, Multiple↗
PubMed1996

[A case of an old woman with Sjögren's syndrome associated with insulin-dependent diabetes mellitus].

Insulin-dependent diabetes mellitus (IDDM) is thought to result from the autoimmune destruction of the insulin-dependent beta cells of the pancreas. Sjögren's syndrome is also an autoimmune disease characterized by the destruction of the lacrimal and salivary glands that leads to keratoconjunctivitis sicca and xerostomia. But it is a very rare case that a patient with Sjögren's syndrome developed IDDM. We present a case of a 65-year old woman with Sjögren's syndrome who developed diabetic ketoacidosis due to IDDM. Recent studies have revealed that there was molecular mimicry between glutamic acid decarboxylase (GAD) and coxsackievirus. Furthermore, some reports have shown that sialadenitis was represented in IDDM model mice. This case shows the possibility that a causal relationship between IDDM and Sjögren's syndrome may exist.

Aged↗
PubMed1996

Reactive arthritis induced by tonsillitis.

We describe 13 adult patients with reactive arthritis induced by tonsillitis. Arthritis occurred 710 days after tonsillitis and involved the wrists, knees, feet and sternoclavicular joints. Some cases had pain in the Achilles tendon areas. Synovial fluid examined in 4 patients was sterile. All patients except 3 showed unequivocal elevation of serum ASO and/or ASK. Streptococcus was isolated from tonsillar swabs in 7 patients. One had maculopapular erythema and 2 had abdominal pain of unknown origin, but none had cardiac involvement, chorea and subcutaneous nodule. HLA examination revealed that 4 had B39 (p <0.005). Eight cases were treated with antibiotics. Five cases underwent tonsillectomy. All tonsils had cryptic abscess. No exacerbation was seen thereafter. These cases probably represent reactive arthritis induced by tonsillitis and should be distinguished from other rheumatic diseases.

Adult↗
PubMed1995

Isolation and characterization of novel heterogeneous branched cyclomalto-oligosaccharides (cyclodextrins) produced by transgalactosylation with alpha-galactosidase from coffee bean.

Transgalactosylated derivatives of cyclomalto-hexaose (alpha CD), -heptaose (beta CD), and -octaose (gamma CD) were synthesized by alpha-galactosidase from coffee bean using melibiose as a donor and alpha CD, beta CD or gamma CD as an acceptor. Mono- and di-O-alpha-D- galactosylated CDs were isolated and purified by HPLC. Their structures were elucidated by fast-atom bombardment mass spectrometry (FABMS) and 13C NMR spectroscopy. For structural determination of positional isomers of 6(1),6n-di-O-alpha-D-galactosyl-CDs, digestion products with cyclodextrin glucanotransferase were analyzed by HPLC and FABMS.

Carbohydrate Conformation↗
PubMed1995

Structure of the gene encoding the mouse pituitary adenylate cyclase-activating polypeptide receptor.

The PACAP-R gene, encoding the mouse pituitary adenylate cyclase-activating polypeptide receptor (PACAP-R), has been isolated and its structural organization has been determined. PACAP-R spans more than 50 kb and is divided into 18 exons. PACAP-R contains two alternative exons encoding the putative third intracellular loop, as found in the rat PACAP-R. The proximal promoter region is highly G+C rich and lacks an apparent TATA box, but contains a CCAAT box and two potential Sp1-binding sites.

Animals↗
PubMed1995

Plasma neuropeptide Y is reduced in patients with Alzheimer's disease.

Neuropeptide Y (NPY) is demonstrated to be involved in the pathophysiology of Alzheimer's disease, as well as somatostatin. We measured the plasma NPY content in patients with Alzheimer's disease and healthy control subjects (n = 25) by HPLC coupled with radioimmunoassay. The difference in screening pattern of NPY-like immunoreactivity in 50 fractions eluted by HPLC obtained from the plasma peptide-rich fraction between patients with Alzheimer's disease and healthy controls suggested the abnormal metabolism of plasma NPY in patients with Alzheimer's disease. Plasma NPY in patients with Alzheimer's disease was significantly decreased compared with that in healthy controls, which was compatible with the findings obtained from the brain and cerebrospinal fluid and could be involved in the pathogenesis or pathophysiology of Alzheimer's disease.

Aged↗
PubMed1995

Inhibition of etoposide (VP-16)-induced DNA recombination and mutant frequency by Bcl-2 protein overexpression.

Bcl-2 has been shown to inhibit apoptosis induced by several anticancer agents and to cause a dissociation between etoposide (VP-16)-induced protein-cross-linked DNA strand breaks and VP-16-induced cell death. We suggested previously that VP-16-induced cytotoxicity is mediated by a series of events leading from cleavable complex formation to aberrant DNA recombination, as measured by sister chromatid exchange (SCE) and Southern blot analysis of the hypoxanthine phosphoribosyl transferase (hprt) gene mutations. To further evaluate this hypothesis and to determine whether Bcl-2 could affect any steps leading to the aberrant DNA recombination process, we stably transfected an expression vector containing human Bcl-2 cDNA into V79 Chinese hamster cells. This transfection resulted in overexpression of the Bcl-2 gene product. We subsequently quantitated the relationship between VP-16-induced cytotoxicity, DNA strand breaks, SCE, and mutant frequency at the hprt locus in these Bcl-2-overexpressing cells. Two independent Bcl-2-overexpressing cell lines, BCL2/2 and BCL2/4, showed 3-5 times higher survival at 15 microM VP-16 compared with parental V79 cells or control NeoR cells that were obtained by transfecting V79 cells with the expression vector containing the G-418 resistance gene only. DNA single-strand breaks induced by VP-16 were similar in parental V79, control NeoR, BCL2/2, and BCL2/4 cells. In contrast, VP-16 induced significantly less SCE in Bcl-2-overexpressing cell lines compared with parental V79 and control NeoR cells. The SCE/chromosome induced by 15 microM VP-16 were 0.65, 0.42, 0.09, and 0.10, respectively, in V79, NeoR, BCL2/2, and BCL2/4. In addition, there was an excellent correlation between VP-16-induced SCE and cytotoxicity in all cell lines. Furthermore, VP-16-induced mutant frequencies at the hprt locus were 5-10 times less in BCL-2/2 and BCL-2/4 cells than those observed in the V79 or NeoR control cells. These results indicate that overexpression of Bcl-2 is associated with reduction in VP-16-induced genetic recombination, mutation, and cytotoxicity. Moreover, they suggest that Bcl-2 modulates cytotoxicity of VP-16 between cleavable complex formation and subsequent induction of DNA recombination events. Thus, our results provide important support for the hypothesis that VP-16-induced cytotoxicity is associated with aberrant recombination events, including gene deletions and rearrangements.

Animals↗
PubMed1995

Involvement of NAD-poly(ADP-ribose) metabolism in p53 regulation and its consequences.

We have used two different approaches to study the consequences of NAD/poly(ADP-ribose) deficiency on p53 expression and its activity in V79-derived cell lines. In the first approach, we have used two cell lines that are deficient in poly(ADP-ribose) (pADPR) synthesis because of deficiency in the enzyme poly(ADP-ribose) polymerase (PARP). In a second approach, we have used a cell line that is deficient in NAD/pADPR metabolism due to unavailability of NAD, the substrate for PARP. These NAD/PARP-deficient cell lines exhibit a significant reduction in both baseline p53 expression and its activity compared to their parental V79 cells. Furthermore, etoposide, a topoisomerase II inhibitor that was shown to cause an increase in p53 expression and subsequent apoptosis in V79 cells, failed to produce any significant increase in p53 expression or apoptotic DNA fragmentation in NAD/PARP-deficient cell lines. Thus, our studies suggest that NAD/pADPR synthesis may be involved in the regulation of p53 and its dependent pathways.

Animals↗
PubMed1995

Simultaneous expression of human CYP3A7 and N-acetyltransferase in Chinese hamster CHL cells results in high cytotoxicity for carcinogenic heterocyclic amines.

To investigate whether several food-derived heterocyclic amines are activated to genotoxic products in human fetal livers, cell lines stably expressing CYP3A7, a human fetus-specific form of cytochrome P450, NADPH-cytochrome P450 reductase, and human monomorphic or polymorphic N-acetyltransferase (NAT1 or NAT2) were established. The expression of CYP3A7 mRNAs and proteins was determined by RNA blot and immunoblot analyses, respectively. The introduction of CYP3A7 cDNA to CR-68 cells which had been transfected with guinea pig NADPH-cytochrome P450 reductase, NAT1, or NAT2 cDNA resulted in increased sensitivity of the cells to aflatoxin B1 compared to parental cells. The cytotoxicity assay for 2-amino-3-methylimidazo[4,5-f]quinoline (IQ), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline (MeIQ), and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) showed that 7P-145 cells, which expressed the reductase, CYP3A7, and NAT2, were approximately 4-, 30-, and 14-fold more sensitive to respective IQ, MeIQ, and MeIQx than parental CR-68 cells. There were no clear differences in sensitivity to these compounds among CHL, CR-68, and the cells which expressed the reductase and CYP3A7 (7R-54), the reductase and NAT1 (CNM-4), the reductase and NAT2 (CNP-40), and the reductase, NAT1, and CYP3A7 (7M-124). From these results, it was suggested that both CYP3A7 and polymorphic NAT2 are required for mutagenic activation of several heterocyclic amines in human fetal livers.

Amines↗
PubMed1995

Enzymic transfer of 6-modified D-galactosyl residues: synthesis of biantennary penta- and hepta-saccharides having two 6-deoxy-D-galactose residues at the nonreducing end and evaluation of 6-deoxy-D-galactosyl transfer to glycoprotein using bovine beta-(1-->4)-galactosyltransferase and UDP-6-deoxy-D-galactose.

UDP-6-Deoxy-D-galactose and UDP-6-deoxy-6-fluoro-D-galactose were synthesized and their transfer to 2-acetamido-2-deoxy-D-glucose (N-acetyl-D-glucosamine) by beta-(1-->4)-galactosyltransferase was examined. The transfer rates of 6-deoxy-D-galactose and 6-deoxy-6-fluoro-D-galactose were 1.3 and 0.2% of that of D-galactosyl transfer, respectively. The 2-acetamido-4-O-(6-deoxy-beta-D-galactopyranosyl)-2-deoxy-D-glucopyranose (6'-deoxy-N-acetyllactosamine) and methyl 2-acetamido-4-O-(6-deoxy-6-fluoro-beta-D-galactopyranosyl)-2-deoxy-D- glucopyranoside (6'-deoxy-6'-fluoro-N-acetyllactosamine) were synthesized enzymatically in 30 and 59% yields, respectively. Further, 6-deoxy-D-galactose could be completely transferred to N-linked type biantennary oligosaccharides having two N-acetyl-D-glucosaminyl residues at the nonreducing end to give the corresponding penta- and hepta-saccharides in 55 and 57% yields, respectively. An assay of 6-deoxy-D-galactosyl transfer using asialo agalacto alpha 1-acid glycoprotein as an acceptor suggested that 6-deoxy-D-galactose was transferred to about 30% of the N-acetyl-D-glucosaminyl residues in the N-linked oligosaccharides of the glycoprotein.

Acetylglucosamine↗