Biomedical subjects

N Hashimoto

Publications and source records attributed to N Hashimoto.

At least 145 records · Page 8Linked to original sources

PubMed1995

Characterization of the mode of Hantaan virus infection in adult mice using a nested reverse transcriptase polymerase chain reaction: transient virus replication in adult mice.

A polymerase chain reaction (PCR) for the detection of hantavirus genome was established and applied to analyze the mode of infection of Hantaan virus in adult ICR mice. The cDNA for the S genome segment of Hantaan virus was reverse-transcribed from the total RNA of organs of the infected mice. The sequence in the S genome segment of Hantaan virus was successfully amplified by reverse transcriptase (RT)-PCR followed by nested PCR. In 5-week-old ICR mice inoculated intraperitoneally with Hantaan virus, strain 76-118 (1.3 x 10(5) FFU/mouse), the virus was detected in clots and lungs from 3 to 10 days post-inoculation (p.i.) by nested PCR and virus-isolation techniques. No virus was detected in any specimens collected on 1 day and after 28 days p.i., and in spleens and brains through the observation period by both methods. The antibody which was measured by indirect immunofluorescence antibody assay (IFA) appeared at 7 days p.i. and the geometric mean titer was elevated to its maximum level of 1:203 at 10 days p.i., maintaining the same level until 35 days p.i. These results suggest that adult mice are transiently infected with Hantaan virus.

Animals↗

PubMed1995

Influence of parental obesity on the physical constitution of preschool children in Japan.

The objective of this study was to assess the influence of parental obesity on the physical constitution of preschool children. A total of 3187 children aged between 1-6 years and their parents were studied. A child whose per cent obesity (%OB; per cent overweight for age, height and sex) was greater than 15%, and a parent whose body mass index (BMI; kg/m2) was greater than the 95th percentile were defined to be obese (27.40 and 25.97 for a father and a mother, respectively). We found that the incidence of obesity in children with obese fathers (11.5%) was significantly higher than in those with non-obese fathers (6.2%), and a similar difference was obtained between children with obese mothers (14.5%) and with non-obese mothers (6.2%), respectively. The incidence of obesity in children was 6.0% if both parents were non-obese; this incidence rose to 22.7% if one parent was obese, and to 30.8% if both were obese. The %OB of children was more markedly correlated with the mothers' BMI (r = 0.219) than the fathers' BMI (r = 0.165). The %OB of children correlated significantly with fathers' BMI, but only from the age of 3-6 years, whereas mothers' BMI correlated from the age of 1-6 years. We conclude that parental obesity was of significance in determining the development of juvenile obesity even in the preschool period.

Body Constitution↗

PubMed1995

Comparison of growth hormone and insulin-like growth factor-I regulation of estradiol and progesterone production in human luteinized granulosa cells.

Growth hormone (GH) appears to affect the timing of puberty in children. The effects of GH on puberty may be related to direct GH action on ovarian function or may be mediated by IGF-I. To determine the likelihood that GH has direct effects on ovarian function, we compared the ability of GH and IGF-I to increase luteinized granulosa cell steroidogenesis in the absence and presence of gonadotropins. Cells were obtained from women undergoing in vitro fertilization for tubal disorders or male factor infertility and were placed in static culture. GH alone failed to alter progesterone or estradiol accumulation in the medium of cultured luteinized granulosa cells. IGF-I produced no increase in progesterone accumulation but increased estradiol accumulation 5.6-fold compared with cells treated with vehicle. The combination of GH and FSH produced an 0.83-fold increase in estradiol accumulation, whereas the combination of IGF-I and FSH resulted in a 2.9-fold increase in estradiol accumulation above FSH alone. Thus the direct effects of GH on granulosa cell steroid synthesis are modest compared with those of IGF-I. If GH has an effect on ovarian development at puberty, it is likely to be mediated by a GH-induced increase in circulating IGF-I.

Cells, Cultured↗

PubMed1995

Insulin resistance associated with decreased levels of insulin-receptor messenger ribonucleic acid: evidence of a de novo mutation in the maternal allele.

Mutations in the insulin receptor gene may lead to insulin resistance and diabetes mellitus in some patients. We have studied an insulin-resistant patient with leprechaunism. Insulin binding to the patient's fibroblasts was markedly decreased. Determination of the nucleotide sequence of the patient's insulin receptor gene revealed heterozygosity for a 2-basepair deletion in exon 15. If the premessenger ribonucleic acid (pre-mRNA) is spliced normally, it causes a replacement of codon 970 in the beta-subunit with a premature chain termination codon, thereby deleting most of the intracellular domain of the receptor. The mRNA transcribed from the allele with a 2-base-pair deletion is likely to be unstable because mRNA transcripts from this allele could not be detected by complementary DNA sequencing. Northern blot analysis showed that the patient's insulin receptor mRNA was decreased by 90% compared with that of a control subject, thus suggesting that the patient is a compound heterozygote for two mutations that decrease levels of insulin receptor mRNA. This deletion mutation in exon 15 seems to be a de novo mutation, because it was not detected in either parent. Investigation of the inheritance of a silent sequence polymorphism in exon 17 provided that the deletion occurred in the maternal allele. Furthermore, linkage analysis suggests that the second mutation is derived from the patient's father, although we could not directly identify it by sequencing the coding region of the insulin receptor gene. Therefore, it is possible that this mutation is present in a regulatory domain of the insulin receptor gene, acting in cis-dominant fashion to reduce the levels of insulin receptor mRNA. Analyses of the hypervariable region in the myoglobin and pMCT118 loci were consistent with the assumption that the father and mother studied here are indeed the biological parents of the diseased patient. We hereby conclude that the patient is a compound heterozygote for two mutant alleles, both of which are responsible for the reduced levels of insulin receptor mRNA and insulin binding.

Adult↗

PubMed1995

Effects of brain-derived neurotrophic factor on 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonism in monkeys.

The effects of intrathecal infusion of brain-derived neurotrophic factor (BDNF) were examined in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced parkinsonian model in monkeys. Nine Japanese monkeys were divided randomly into three groups, an untreated control (n = 3), a BDNF group (n = 3), and a non-BDNF group (n = 3). Animals in the BDNF group received continuous intrathecal infusion of 10 ml of cell culture medium containing 10 micrograms of BDNF protein; the non-BDNF group received intrathecal infusion of the same culture medium without BDNF. To induce parkinsonian syndromes, a total of 1 mg/kg 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine was administered intravenously to each monkey in both the BDNF and non-BDNF groups. The neurological signs in the monkeys were monitored for 2 weeks and were scored according to the monkey parkinsonism rating scale; histological changes in the substantia nigra were evaluated after the 2-week observation period. The BDNF-treated animals remained asymptomatic during the 1st week and showed mild parkinsonism during the 2nd week, whereas the non-BDNF group showed typical parkinsonian syndrome during the 1st week, with deterioration in the 2nd week. Histological damage in the substantia nigra correlated well with the clinical features. Severe neuronal cell loss in the substantia nigra was observed in animals with severe parkinsonism (those in the non-BDNF group), whereas significantly less damage was observed in this region in the BDNF group.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗

PubMed1995

[An autopsy case of dermatomyositis with rapidly progressive interstitial pneumonia].

An autopsy case of dermatomyositis with rapidly progressive interstitial pneumonia is reported. a 48-year-old woman was admitted because of facial edematous erythema and muscular weakness. A diagnosis of dermatomyositis was made because of typical erythema and myogenic pattern of EMG, although serum creatine kinase was within normal range. The chest X-ray film showed that interstitial pneumonia was complicated. She was treated with prednisolone of 60 mg/day. Although erythema and althralgia was improved remarkably, interstitial pneumonia was progressed unfavorably. Therefore pulse therapy with methylprednisolone was administered twice, but failed to respond. After that interstitial pneumonia was progressed rapidly, she was died of respiratory failure. The autopsy findings detected that a degeneration and necrosis of striated muscular fibers in whole body, that a mixed findings of usual interstitial pneumonia and diffuse alveolar damage in the lung. Vasculitis and fiblinous pleuritis was also found in the lung. Malignancy was not detected.

Dermatomyositis↗

PubMed1995

Arteriovenous fistula around the ventriculoperitoneal shunt system in a patient with a dural arteriovenous malformation of the posterior fossa. Case report.

A dural arteriovenous malformation (AVM) of the posterior fossa can produce persistent tinnitus, convulsions, and dementia. Successful therapeutic embolization may result in a complete cure, but in some cases, patients do not respond to the treatment. The authors report a patient with a dural AVM of the posterior fossa that did not respond to repeated intravascular treatments, but resulted in an arteriovenous shunt in the scalp around the ventriculoperitoneal shunt system. Although several hypotheses have been proposed on the pathogenesis of dural AVMs, the underlying mechanisms remain unknown. The rare complication we encountered may shed some light on the pathogenesis of dural AVMs.

Arteriovenous Fistula↗

PubMed1995

Evidence for the existence of Puumula-related virus among Clethrionomys rufocanus in Hokkaido, Japan.

We conducted field surveys of indigenous rodent species in Hokkaido, Japan from 1980 to 1993. Serum samples were collected from 663 rodents, including Clethrionomys rufocanus, Apodemus speciosus, A. argenteus, and C. rutilus. Antibody to hantavirus was determined by the protein G antibody assay. Positive C. rufocanus were detected in seven of eight collection sites, but no antibody was detected in the remaining rodent species. To reveal the serotype of the circulating virus in C. rufocanus, antibody titers to Hantaan, Seoul, Puumala, and Prospect Hill viruses were compared by means of the focus reduction neutralization test. The titers in positive sera were extremely high to the Sotkamo strain of Puumala virus. Results were confirmed by the reverse transcriptase-polymerase chain reaction, and suggested that Puumala-related viruses are in circulation among C. rufocanus populations in Hokkaido.

Animals↗

PubMed1995

[Efficacy of repeated hepatic dearterialization combined with intra-arterial infusion chemotherapy for unresectable tumors of the liver].

In the present study, repeated hepatic dearterialization combined with intra-arterial infusion chemotherapy was performed in patients with unresectable tumors of the liver. Of 36 patients, 16 had primary liver tumors (13 hepatocellular carcinomas and 3 cholangiocellular carcinomas), while 20 had metastatic tumors (7 gastric carcinomas, 10 colon carcinomas, 2 pancreatic carcinomas, and 1 gastric carcinoid). A significantly better survival outcome was found in those with intra-arterial infusion chemotherapy and those without cirrhosis. In the HCC cases, those with the therapy tended to show a better survival as compared with the natural history. Remarkable tumor regression was found in four (67%) of six patients with metastases of gastric cancer.

Aged↗

PubMed1995

[Collagen disease. Autoimmune disease].

Collagen disease is systemic autoimmune disease and consists of a lot of diseases with each clinical entity. for exact diagnosis, it is important to choose essential laboratory tests for the patient suspected of collagen disease in daily primary medical care. A guideline for the use of clinical laboratory tests for patients with collagen disease was proposed by the Japan Society of Clinical Pathology. This guideline was discussed repeatedly by subcommittee members of "the uses of clinical laboratory tests in daily primary medical care" and published on September of 1990. When the clinicians are suspected of the collagen disease from detailed history taking and physical examination, they must precisely interpret results of the essential laboratory tests. Urinalysis, hematology, ESR and CRP and Biochemistry show characteristic findings in the collagen disease, respectively. If further suspicion of the collagen disease is intensive, the clinicians proceed with the primary screening tests for collagen disease; rheumatoid factor, ANF, anti DNA antibody, LE test, STS and CH50. Finally, specific tests for each collagen disease are carried out to define the diagnosis; e.g. LE cell, anti-Sm antibody, IC, Coombs test and biopsy of kidney for SLE. This paper is presented on the intention of the guideline of clinical laboratory tests for the collagen disease and its issues. As it passed 4 years after published, this guideline should be more discussed and revised.

Autoimmune Diseases↗

PubMed1995

Embolization of dural arteriovenous fistulas with interlocking detachable coils.

Our clinical experience with interlocking detachable coils for the embolization of high-flow dural arteriovenous fistulas is reported. Interlocking detachable coils are useful for transarterial and transvenous embolizations of dural arteriovenous fistulas because (a) immediate coil detachment is possible, (b) the coils can be replaced easily, (c) detached coils rarely migrate, and (d) fewer interlocking detachable coils than conventional fiber coils are required for successful embolization.

Aged↗

PubMed1995

Prostanoid secretion by rat hepatic sinusoidal endothelial cells and its regulation by exogenous adenosine triphosphate.

We investigated the secretory profiles of prostanoids in two types of nonparenchymal cell from the rat liver, sinusoidal endothelial cells and Kupffer cells, in primary culture both under basal conditions and after stimulation with adenine nucleotides. Prostaglandin (PG) E2 was the main prostanoid secreted by both types of hepatic nonparenchymal cell in the basal and adenosine triphosphate (ATP)-stimulated states. Time- and concentration-dependent effects of ATP-mediated PGE2 secretion were noted in sinusoidal endothelial cells, whereas the profile of the relative potencies of individual nucleotides was consistent with the presence of P2y and P1 purinergic receptors. In Kupffer cells, the regulation of prostanoid secretion by adenine nucleotides was essentially the same as that in sinusoidal endothelial cells except that adenosine did not stimulate prostanoid secretion and that prostanoid secretion differed somewhat; Kupffer cells secreted relatively more PGF2 alpha and less 6-keto-PGF1 alpha than sinusoidal endothelial cells in the presence of ATP, suggesting the presence of only P2y receptors. In summary, PGE2 is the main prostanoid secreted by hepatic nonparenchymal cells and its secretion may be stimulated by adenine nucleotides and adenosine.

Adenine Nucleotides↗

PubMed1995

[MRI of the pituitary adenomas with reference to the hormonal activity].

Many studies in Magnetic Resonance Imaging (MRI) of pituitary adenomas are already performed. However, few reports exist about MRI findings of pituitary adenomas with reference to the hormonal activity, therefore, we evaluated this problem on the viewpoint of the signal intensity in MRI and pathological features. Fifteen patients with growth hormone producing adenoma (GH-group), 6 patients with prolactin producing adenoma (PRL-group), 15 patients with endocrinologically non-functioning adenoma (Null-group) and 9 cases with normal pituitary gland (normal control group) were examined. Signal intensity values in adenoma (or anterior lobe in normal control group) and in pons as standard value were measured in each cases, then their rates were calculated as signal intensity ratio (SIR). In 24 cases (14 in GH-group, 3 in PRL-group, 7 in Null-group), cellular density were examined with surgically resected specimens. In the T1-weighted images (T1 WIs), PRL-group and Null-group presented more hypointense tendency than normal control group. In the T2-weighted images (T2 WIs), only Null-group presented more hyperintense tendency than other groups. But significant correlation was not observed between SIR and cellular density.

Adenoma↗

PubMed1995

[The clinical study on secretory leukoprotease inhibitor (SLPI) in sera of patients with various pulmonary diseases].

It has been reported that secretory leukoprotease inhibitor (SLPI) can be a useful indicator for acute respiratory tract inflammation. In the present study, we attempted to measure automatically the serum concentration of SLPI by enzyme immunoassay (EIA) in patients with various pulmonary diseases. In this automatic measurement of SLPI, by which the results basically well-correlate with the manual method, we could measure many samples easily. Serum levels of SLPI in patients with various pulmonary diseases were significantly higher than those in healthy controls (50.5 +/- 9.8ng/ml). The serum concentration of SLPI in patients with inflammatory lung diseases correlated with that of C-reactive protein (CRP) or interleukin 6 (IL-6) significantly but not strongly. These results suggest that SLPI may be a useful indicator for local inflammation in respiratory tract. The serum concentration of SLPI in patients with lung cancer (71.1 +/- 10.8ng/ml), in particular adenocarcinoma, was significantly higher than that in healthy controls, but not correlated with other inflammatory markers.

Adult↗

PubMed1995

[Mechanisms of hypertonic saline-induced bronchoconstriction in guinea pigs].

We examined whether inhalation of hypertonic saline can induce bronchoconstriction in guinea pigs, and also studied the mechanisms of this bronchoconstriction. Twenty-five male Hartley guinea pigs were divided into the following 5 groups: G-1, 0.9% saline inhalation; G-2. non-treatment and inhalation of hypertonic saline; G-3, capsaicin pretreatment and inhalation of hypertonic salines; G-4, ipratropium bromide pretreatment and inhalation of hypertonic saline; G-5, chlorpheniramine pretreatment and inhalation of hypertonic saline. RL and Cdyn were serially measured to assess bronchoconstriction, and the percent increase in RL from the value measured before inhalation of hypertonic saline (%RL) was analyzed. The maximum %RL was 9.2 +/- 3.8% in G-1, 90.6 +/- 6.6% in G-2, 11.2 +/- 5.7% in G-3, 9.0 +/- 6.0% in G-4, and 47.8 +/- 4.0% in G-5. The values in G-3 and G-4 were significantly lower than in G-2. We conclude that inhalation of hypertonic saline causes concentration dependent bronchoconstriction in guinea pigs and that both non-adrenergic non-cholinergic nerves and cholinergic nerves may play an important role in this bronchoconstriction.

Animals↗

PubMed1995

Production of recombinant hantavirus nucleocapsid protein expressed in silkworm larvae and its use as a diagnostic antigen in detecting antibodies in serum from infected rats.

The recombinant nucleocapsid protein (rNP) of Hantaan virus was expressed by a baculovirus vector in silkworm hemolymph and was used as an antigen in western blotting (WB). The rNP is expressed in insoluble form in hemolymph; therefore simple washing of the insoluble fraction with phosphate-buffered saline by low-speed centrifugation allowed preparation of purified antigen for WB. The rNP had strain-specific and hantavirus-common epitopes similar to the authentic NP antigen of hantavirus and was stable after transfer to membrane. For detection of antibody in serially obtained sera from experimentally infected rats, WB enabled detection of IgM antibodies 3 days after infection, which was at least 2 days earlier than detection by the indirect immunofluorescent antibody test (IFA). Thus WB had a higher sensitivity than the IFA for detection of hantavirus antibody in the serum of experimentally infected rats. The WB-determined IgG antibody titer was about 10 times higher than that determined by the IFA. No background staining was observed by WB even at a 1:10 dilution of serum. The selected rat sera with strong background staining or confusing staining patterns by IFA, but not focus reduction neutralization test titers, could be interpreted as test-negative because they did not have a specific reaction to virus antigen by WB. Thus the specificity of WB was higher than that of the IFA. Moreover, WB can distinguish specific from nonspecific reactions by the detection of the specific antigen on the WB membrane. Therefore the IFA or enzyme-linked immunosorbent assay followed by WB is recommended for serologic confirmation of hantavirus infection.

Animals↗

PubMed1994

Phosphorylation of a proline-directed kinase motif is responsible for structural changes in myogenin.

Myogenin, a member of the MyoD family which governs skeletal muscle differentiation, was identified as a pair of phosphorylated bands on SDS-PAGE during myogenesis. The slow migrating form was found to be hyperphosphorylated myogenin. In vitro phosphorylation by CDC2 kinase caused a prominent reduction in electrophoretic mobility of myogenin. Furthermore, we demonstrated that phosphorylation of the serine residue at position 43 contributes to the modification of myogenin in vivo and in vitro resulting in the reduction in electrophoretic mobility. We propose here that a CDC2-like proline-directed kinase regulates myogenin activity through its phosphorylation.

Amino Acid Sequence↗

PubMed1994

Molecular cloning and expression of a unique receptor-like protein-tyrosine-phosphatase in the leucocyte-common-antigen-related phosphate family.

Protein-tyrosine-phosphatases (PTPases) have been implicated in the regulation of certain tyrosine kinase growth factor receptors in that they dephosphorylate the activated (autophosphorylated) form of the receptors. In order to identify PTPases that potentially act on receptor targets in liver, we used the human leucocyte common antigen-related PTPase (LAR) cDNA [Streuli, Krueger, Hall, Schlossman and Saito (1988) J. Exp. Med. 168, 1523-1530] and isolated two closely related transmembrane PTPase homologues from a rat hepatic cDNA library. Both PTPases had large extracellular domains that contained three immunoglobulin-like repeats and eight type-III fibronectin repeats. Both enzymes had tandem homologous PTPase domains following a single hydrophobic transmembrane domain. One sequence encoded the rat homologue of LAR. The second PTPase, designated LAR-PTP2, had 79 and 90% identity with rat LAR in the respective cytoplasmic PTPase domains, with only 57% sequence similarity in the extracellular domain. The catalytic domains of LAR and LAR-PTP2 prepared by bacterial expression were active in dephosphorylating a variety of phosphotyrosyl substrates but did not hydrolyse phosphoserine or phosphothreonine residues of labelled casein. Both enzymes exhibited rapid turnover numbers of 4-7 s-1 for myelin basic protein and 78-150 s-1 for derivatized lysozyme. LAR and LAR-PTP2 displayed similar PTPase activity towards the simultaneous dephosphorylation of receptors of intact insulin and epidermal growth factor from liver membranes. These data indicate that there is a family of LAR-related PTPases that may regulate the phosphorylation state of receptor tyrosine kinases in liver and other tissues.

Amino Acid Sequence↗