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Biomedical subjects

J Matsuda

Publications and source records attributed to J Matsuda.

At least 55 records · Page 3Linked to original sources
PubMed2000

Development of embryos in superovulated guinea pigs following active immunization against the inhibin alpha-subunit.

Embryo recovery and subsequent embryonic development from guinea pigs treated with or without inhibin vaccines were compared to determine the effect of active immunization against the inhibin alpha-subunit. Twenty female guinea pigs of the Hartley strain were injected 3 times either with 1 ml inhibin vaccine (recombinant ovine inhibin a-subunit in oil emulsion: 50 microg/ml, inhibin-immunized group), or 1 ml placebo (saline in oil emulsion; control group) at 4 week intervals. After one estrous cycle following the last injection, females were naturally mated and embryos were collected at 11:00 hr of day 6 of pregnancy (Day 1: sperm in the vaginal smear) for culture in vitro. Active immunization increased the number of corpora lutea (12.6+/-3.0 vs. 4.6+/-0.2, P<0.05), recovered embryos (9.8+/-1.9 vs. 3.6+/-0.4, P<0.01) and normal embryos (7.8+/-1.4 vs. 3.6+/-0.4, P<0.05), although estrous cycle length was not affected (P>0.05). During subsequent 8 day culture in vitro, most of the recovered embryos formed trophoblast outgrowth; 100% (14/14) and 88.2% (15/17) in control and immunized groups, respectively. High levels of inhibin antibody titers were sustained in the inhibin-immunized guinea pigs at least for 5 months after the last injection while no antibody titer was detected in the control animals. These results indicate that active immunization against the inhibin a-subunit is a long-acting and efficient method to induce superovulation with normal embryonic development in the guinea pig.

Animals↗
PubMed2000

[Recurrent pulmonary embolism from left subclavian thrombosis: a case report].

A 38-year-old woman was admitted to our hospital because of pulmonary thromboembolism. Thrombolysis therapy resulted in initial improvement in symptoms and laboratory data. However, 4 months later, pulmonary thromboembolism recurred despite antiplatelet and anticoagulation therapy. Contrast venography and venous ultrasonography of both upper and lower extremities revealed subtotal occlusion and venous thrombosis of the left subclavian vein with collateral vessels, but no evidence of lower extremity venous thrombosis. She had no history of subclavian venous catheterization, neoplasm, hypercoagulability or other predisposing cause of thrombus formation. Operative ligation of the left subclavian vein was performed at the junction with the internal jugular vein. White thrombus was identified within the venous lumen. She was well without recurrent pulmonary thromboembolism or venous insufficiency for 10 months after the operation. Surgical interruption of the subclavian vein may be effective to prevent recurrent pulmonary thromboembolism in patients with recurrent pulmonary thromboembolism due to venous thrombosis of the upper extremity despite therapeutic anticoagulation.

Adult↗
PubMed2000

Kawasaki disease: a diagnostic challenge.

Kawasaki disease (KD) is an acute, self-limited, febrile, multi-system vasculitis that predominantly affects the the pediatric population, and is the leading cause of acquired heart disease in children. No etiologic agent for the disease has been identified, there are no diagnostic tests available, and the diagnosis is established by fulfilling a defined set of clinical criteria. We report on a 9-year-old boy who presented initially with symptoms felt to represent a streptococcal infection. He was subsequently shown to meet the criteria for KD, developed cardiac complications of the disease and subsequently demonstrated recovery over a year's period of time. The diagnostic criteria for KD, differential diagnosis, pitfalls in diagnosis, therapeutic recommendations and outcomes are discussed with relevance to this case. Recent print and electronic information sources and references are provided.

Child↗
PubMed1999

Closely linked polymorphic markers for determining the autosomal dominant allele (Cy) in rat polycystic kidney disease.

The Han:SPRD strain is an SD-background strain known to be a model of polycystic kidney disease (PKD) expressed through an autosomal dominant gene (Cy). However, different genotypes of this strain cannot be identified in the neonatal period. First, to establish an accurate method of determining the genotypes (Cy/Cy, Cy/+, +/+) which cause different disease progressions, we used polymorphic markers on rat chromosome 5. PCR products of tissue DNA templated with D5Rat9 showed distinct patterns on electrophoresis indicating three genotypes. Second, to determine whether the same locus plays a major role in expressing PKD, we performed linkage analyses in a [BN x (BN x Han:SPRD)F1] backcross. Cy/Cy and Cy/+ also caused PKD in a BN background. In this backcross, we discovered that D5Rat11 is located closer to the Cy locus than D5Mgh10, which is regarded as one of the closest loci. We conclude that D5Rat9 and D5Rat11 are useful markers for determining the presence of the Cy allele, which is regarded as the gene responsible for PKD.

Alleles↗
PubMed1999

New members of uncoupling protein family implicated in energy metabolism.

1. The regulation of energy metabolism involves food intake and energy expenditure. Mitochondrial uncoupling proteins (UCP) are implicated in energy expenditure. 2. cDNA of a homologue of UCP highly expressed in rat skeletal muscle, UCP-3, is isolated and sequenced. Rat UCP-2 cDNA is also isolated and sequenced. 3. Rat UCP-3 cDNA probe hybridized two bands, a major band at 2.5 kb and a minor band at 2.8 kb in rat tissues. The mRNA was expressed at the highest level in the skeletal muscle, and moderately in the interscapular brown adipose tissue (BAT). Only weak signals were detected in the epididymal white adipose tissue (WAT) and the heart. Rat UCP-2 cDNA probe hybridized a 1.7 kb band detected widely in the whole body, especially abundant in the lung and the spleen. In contrast to the UCP-3 gene expression, the UCP-2 gene expression was expressed at substantial levels in the WAT and only at slight levels in the skeletal muscle and BAT. 4. The UCP-3 gene expression is augmented two-fold in the gastrocnemius muscle from rats fed a high-fat diet (P < 0.05). The UCP-3 mRNA levels remained unchanged in the interscapular BAT, and epididymal WAT. The levels of the UCP-2 gene expression are augmented significantly in the epididymal WAT (1.6-fold; P < 0.05), while no significant increase is observed in the gastrocnemius muscle and interscapular BAT.

Adipose Tissue↗
PubMed1999

Mouse spermatid nuclei can support full term development after premature chromosome condensation within mature oocytes.

The nucleus of round spermatids, the earliest haploid male germ cells, can participate in the formation of normal zygotes when incorporated into activated oocytes. In this study, we injected mouse round spermatids into homologous mature oocytes that were kept arrested at metaphase II to induce premature chromosome condensation (PCC) of the spermatid nuclei. After full condensation of the spermatid chromosomes, the oocytes were activated by Sr2+-containing medium, into which cytochalasin B was added to prevent extrusion of the segregated female and male chromosomes as polar bodies. Out of 142 oocytes examined, 104 (73%) formed two male (pseudo)pronuclei and two female pronuclei. To restore the diploid state of these zygotes, one of the female pronuclei was removed. When cultured in vitro for 72 hours, all (n = 37) of the constructed embryos developed to the morula/blastocyst stage. When 2-cell embryos and morulae/blastocysts were transferred into pseudopregnant females, 14 (13/96) and 24% (9/37), respectively, developed into term offspring. This study indicates that the spermatid chromosomes, which had undergone PCC, moved safely to opposite poles after oocyte activation. Since round spermatids contain no (in the mouse) or little (in patients with spermatogenic failure) oocyte-activating factor, this method may be used to rescue oocytes that fail to be activated at the time of spermatid injection.

Animals↗
PubMed1999

Dynamic changes in serum leptin concentrations during the fetal and neonatal periods.

We investigated the dynamics of the leptin concentration throughout the perinatal period. Serum leptin concentrations in venous cord blood at different gestational ages were measured in 20 preterm and 139 term newborns, as well as in 143 pregnant women and 24 term newborns at approximately 6 d of life. Leptin concentrations in preterm newborns (mean 4.6+/-6.9 ng/mL) were lower than those in term newborns (mean 19.6+/-14.3 ng/mL) and tended to increase according to gestational age and birth weight, especially from the late stage of gestation. Leptin concentrations in pregnant women increased from the first trimester and then remained higher than those in non-pregnant women throughout the remainder of pregnancy even after controlling for body mass index. The leptin concentrations of newborns declined rapidly and were extremely low by approximately 6 d of life (mean 1.9+/-1.1 ng/mL). These results suggest that fetuses might produce a part of circulating leptin in their own adipocytes and that the relatively high leptin concentrations at birth and their rapid decline in the early neonatal period might reflect the dramatic changes of the hormonal and nutritional state during the perinatal period.

Body Mass Index↗
PubMed1999

Development changes in long-form leptin receptor expression and localization in rat brain.

The expression and localization of long-form leptin receptor (OB-Rb) were studied immunocytochemically in the brain of fetal and adult rats using a polyclonal antibody that specifically recognized OB-Rb. At 14 days of gestation, immunoreactive cells were observed in the ventricular layer, which contains premature neuronal cells. At 18 days of gestation, they were weakly stained but obvious in the paraventricular nucleus (PVN), and ependymal cells also showed immunoreactivity. At birth, the immunoreactivity of OB-Rb in the PVN seemed to be much lower than that in adult rats and remained low during the suckling period. Considering the presence of neuroendocrine and structural neuronal abnormalities in Lepob/Lepob mice with genetic leptin deficiency, these results suggest that the expression of OB-Rb in premature neuronal cells may have some function, and that the regulation of energy balance by leptin through hypothalamic regions, such as PVN, may not yet be developed in the perinatal period.

Aging↗
PubMed1999

Effect of genetic background on establishment of mouse embryonic stem cells.

We established 13 embryonic stem (ES) cell lines from 542 embryos crossed between various strains of mice: 10 lines from 129/Sv-ter embryos (10/48, 20.8%) and 3 lines out of other 9 combinations of intra- or inter-strain matings (1 from intracross of C57BL/6CrSlc, 1 from B6D2F1 x C57BL/6CrSlc, 1 from Yok:ddY x Slc:ICR). No ES cell line from 129/Sv-ter x Slc:ICR embryos suggests that ICR strain might have inhibitory genetic factor(s) for the ES cell formation. Some ES cell lines could be obtained from hybrids even if none or few lines from their parental strains, suggesting a heterosis effect can be expected for establishing ES cell lines in mice.

Animals↗
PubMed1999

[One-hour protocol stress myocardial scintigraphy: prospective study of diagnostic accuracy for the detection of coronary artery stenosis].

A one-hour protocol for stress myocardial scintigraphy using technetium-99m-tetrofosmin (Tc-tetrofosmin) was compared with coronary arteriography for the detection of coronary artery stenosis in 90 consecutive patients without prior myocardial infarction, revascularization procedure or vasospastic angina. Tc-tetrofosmin stress myocardial scintigraphy acquired a rest image 20 min after intravenous administration of Tc-tetrofosmin (185 MBq, 1/5 vial) using a three-head gamma camera collecting 20-sec views over 360 degrees. The stress test using bicycle ergometer was performed and administration of Tc-tetrofosmin (740 MBq, 4/5 vial) was repeated at the peak stress point. The stress image was acquired 15 min after the second injection with 5-sec views over 360 degrees. Coronary arteriography revealed the presence of significant coronary artery stenosis (> 75%) in 56 vessels of 45 patients, including 35 patients with single-vessel disease, 5 with two-vessel disease, 2 with three-vessel disease, and 3 with left main trunk disease. The overall sensitivity and specificity for the detection of coronary artery disease by visual analysis were 91.1% and 77.8%, respectively, and by quantitative analyses (using bull's-eye method) were 95.6% and 91.1%, respectively. The individual stenotic vessel sensitivities in the right coronary artery, left anterior descending artery, and left circumflex artery were 84.6%, 90.9%, and 78.6%, respectively. The specificities were 97.3%, 95.9%, and 100.0%, respectively. These results suggest that stress myocardial scintigraphy using the present new protocol is a promising approach for the detection of coronary artery stenosis.

Angina Pectoris↗
PubMed1999

[Hemopexin].

Explore the source record for details and available documents.

Hemopexin↗
PubMed1998

Structural requirements for galactosylceramide recognition by CD1-restricted NK T cells.

The reactivity of a group of mouse Valpha14+ NK T cell hybridomas was tested with a panel of analogs of the glycolipid alpha-galactosylceramide (alpha-GalCer). Interestingly, the nearly complete truncation of the acyl chain from 24 to 2 carbons does not significantly affect the mouse NK T cell response to glycolipid presented by either mouse CD1 (mCD1) or its human homolog CD1d (hCD1d). Therefore, we propose that only one of the two hydrophobic pockets of the CD1 Ag-binding groove needs to be filled by Ag. In terms of the sphingosine base, the mCD1 binding groove has less-demanding structural requirements for presentation to NK T cells than hCDld. Tests of NK T cell reactivity to analogs presented by hCDld demonstrates that the invariant TCRs expressed by mouse and human NK T cells are surprisingly similar in their requirements for glycolipid recognition.

Animals↗
PubMed1998

Effect of growth hormone on the translocation of GLUT4 and its relation to insulin-like and anti-insulin action.

To elucidate the effect of growth hormone (GH) on the insulin signal transduction pathway leading to the translocation of glucose transporter-4 (GLUT4), we constructed Chinese hamster ovary cells that overexpressed GH receptor and GLUT4. Treatment with GH triggered GLUT4 translocation, and this translocation was completely inhibited by wortmannin. GH-induced GLUT4 translocation reached a maximum level after 30 min, and then gradually decreased and returned to the basal level after 2 h. Tyrosine phosphorylation of JAK2 also became maximal after 30 min and then gradually decreased. In contrast, GLUT4 translocation remained unchanged for 2 h after insulin treatment, and tyrosine phosphorylation of insulin receptor substrate-1 (IRS-1) also remained constant for up to 2 h. Chronic GH treatment had almost no effect on insulin-stimulated Akt kinase activation and GLUT4 translocation. These results suggest that GH and insulin translocate GLUT4 in a similar manner, at least in part, and the difference in translocation depends on the difference in the tyrosine phosphorylation of JAK2 and IRS-1. The anti-insulin action of GH after chronic GH treatment does not appear to be mainly due to the inhibition of GLUT4 translocation.

Androstadienes↗
PubMed1998

Development of normal mice from metaphase I oocytes fertilized with primary spermatocytes.

Primary spermatocytes are the male germ cells before meiosis I. To examine whether these 4n diploid cells are genetically competent to fertilize oocytes and support full embryo development, we introduced the nuclei of pachytene/diplotene spermatocytes into oocytes that were arrested in prophase I (germinal vesicle stage), metaphase I, or metaphase II (Met II). Both the paternal and maternal chromosomes then were allowed to undergo meiosis synchronously until Met II. In the first and second groups, the paternal and maternal chromosomes had intermingled to form a large Met II plate, which was then transferred into a fresh enucleated Met II oocyte. In the third group, the paternal Met II chromosomes were obtained by transferring spermatocyte nuclei into Met II oocytes twice. After activation of the Met II oocytes that were produced, those microfertilized at metaphase I showed the best developmental ability in vitro, and three of these embryos developed into full-term offspring after embryo transfer. Two pups (one male and one female) were proven to be fertile. This finding provides direct evidence that the nuclei of male germ cells acquire the ability to fertilize oocytes before the first meiotic division.

Animals↗