Biomedical subjects

T Matsui

Publications and source records attributed to T Matsui.

At least 433 records · Page 24Linked to original sources

PubMed1996

Combined effects of acute lead acetate exposure and tone exposure of the guinea pig cochlea.

Lead acetate exposure to humans can induce various disorders of the cranial nerves. Although vertigo and sensorineural deafness have been reported in lead workers, the dose effects of lead acetate on the cochlea and eighth cranial nerve are not well documented. We investigated the effects of lead acetate on the male albino Hartley guinea pig cochlea by measuring cochlear microphonics (CM), whole nerve action potential (AP), endocochlear potential (EP) and K+ ion concentration of the endolymph. Animals were given lead acetate by intraperitoneal injection as 20 mg/week for 4 consecutive weeks. A total dose < 80 mg did not induce electrophysiological changes in the cochlea. However, the AP output voltage (N1) decreased if the 80 mg lead acetate treatment was followed by an 80 dB tone exposure at 6 kHz during 24 h. A change was observed in CM and EP but not K+ ion concentration in the scala media.

Action Potentials↗

PubMed1996

Control of gastric pH with ranitidine in patients with Crohn's disease receiving total parenteral nutrition. Comparison of two intravenous regimens.

Eleven patients with Crohn's disease in remission who were receiving total parenteral nutrition (TPN) underwent continuous intragastric 24-h pH monitoring before and during ranitidine administration. The patients were randomly allocated to receive 200 mg/day (group 1) or 400 mg/day (group 2) of ranitidine by continuous infusion. The mean basal 24-h gastric pH was sustained at a low value. After raintidine administration, the mean pH increased significantly both in group 1 (from 2.13 to 3.28) and in group 2 (from 1.91 to 3.36), with the mean holding-time at pH-3 also increasing significantly in both groups. There were no differences in the mean pH or holding-time at pH-3 between the two groups during ranitidine administration; however, the plasma ranitidine concentration was significantly higher in group 2. These findings indicate that the continuous infusion of a standard dose of ranitidine exerted a maximal inhibitory effect on the sustained hyperacidity induced by TPN, but that this infusion was unable to maintain the intragastric pH level at above 3.5.

Adolescent↗

PubMed1996

Sperm immobilization antibodies in infertile male sera decrease the acrosome reaction: a possible mechanism for immunologic infertility.

OBJECTIVE: To study the effect of sperm-immobilizing antibodies from male sera on spontaneous and A23187-induced acrosome reactions (AR). DESIGN: Swim-up spermatozoa obtained from three fertile donors were incubated with 13 sera with sperm-immobilizing antibodies obtained from infertile men and three control sera obtained from healthy fertile males. Sperm acrosomes were examined by staining with pisum sativum agglutinin labeled with fluorescein isothiocyanate (30 micrograms/ml; Sigma Chemical Co., St. Louis. MO) as spontaneous and A23187 (used at a final concentration of 10 microM; Sigma Chemical Co.) induced. RESULTS: The incidence of spontaneous AR of spermatozoa incubated with antisperm antibody positive male sera (6.2 +/- 0.7) was significantly (P < 0.001) lower than that of spermatozoa incubated with control sera (10.7 +/- 0.5). And the incidence of A23187-induced and -inducible (incidence of induced minus spontaneous) ARs of spermatozoa incubated with sperm antibody-positive male sera (12.4 +/- 1.9 and 6.2 +/- 1.9) was significantly lower (P < 0.001) than that of spermatozoa incubated with control sera (31.0 +/- 0.5 and 20.3 +/- 0.9). Sperm-immobilizing antibody-positive sera decreased spontaneous, A23187-induced, and inducible ARs. CONCLUSIONS: Sperm-immobilizing antibodies from male sera interfere with fertilization by inhibiting the AR.

Acrosome↗

PubMed1996

Increased numbers of macrophages in noninflamed gastroduodenal mucosa of patients with Crohn's disease.

We investigated immunostained macrophages in the noninflamed mucosa of Crohn's disease patients. Biopsied specimens from endoscopically normal gastroduodenal mucosa of Crohn's disease, ulcerative colitis, and healthy control patients were studied. Sections were examined immunohistochemically using a monoclonal antibody specific for tissue macrophages (CD68). Immunostained mucosal macrophages in the second part of the duodenum, duodenal bulb, gastric antrum, and gastric body of the Crohn's disease group were more numerous than in the ulcerative colitis and control groups. The characteristic findings of Crohn's disease were aggregations, focal subepithelial dense accumulations, and infiltration throughout the mucosa of macrophages not accompanied by a lymphoid infiltrate. The number of macrophages in the gastroduodenal mucosa bore no relationship with the duration of symptoms, clinical activity, or affected site in the intestine. This suggests that the increased number of macrophages in noninflamed mucosa is a histological change characteristic for Crohn's disease that indicates a persistent latent abnormality involving the entire gastrointestinal tract.

Adolescent↗

PubMed1996

Refractory thrombocytopenia with chromosome 11q23 abnormality.

Although cytopenia is a common manifestation of myelodysplastic syndrome (MDS), isolated thrombocytopenia is rare. The term "refractory thrombocytopenia" (RTC) has been proposed as a counterpart of refractory anemia. We describe here a case of RTC associated with chromosome abnormality on 11q23. A 59-year-old man was admitted because of severe thrombocytopenia. A bone marrow examination revealed an increased number of micromegakaryocytes and the absence of normal-sized megakaryocytes without obvious dysplasia in either the myeloid or the erythroid lineage. A remarkable increase of GPIIb/IIIa (CD41a)-positive precursor cells in the bone marrow was observed. Cytogenetic examination detected the chromosome abnormality, an addition on chromosome 11q23. Translocation of the HRX gene was not detectable by Southern blot analysis. The diagnostic problems of isolated thrombocytopenia and possible participation of gene(s) on chromosome 11q23 in megakaryocytopoiesis as well as early hematopoiesis are discussed.

Biopsy, Needle↗

PubMed1996

Dense microspheres in normal horse brain.

Here were report eosinophilic globular bodies referred to as dense microspheres (DMS), in the brains of normal horse in relation to the ageing process. The characteristic structures of DMS found in the horse were in similar to those previously reported in the human. The DMS were found predominantly in the neuropil of the cerebral cortex, and were shown histochemically to have a proteinaceous content. Electron microscopy showed that the DMS consisted of homogeneous electron-dense material bound by a single membrane and that they were found within the neuronal processes. In addition, immature or small DMS were observed, which seemed to be closely correlated with the endoplasmic reticulum.

Aging↗

PubMed1996

Degenerative axonal swellings in the trigeminal ganglia of cattle.

We examined the acidophilic oval structures which were frequently encountered in the trigeminal ganglia of cattle that clinically showed trigeminal disturbance. Histopathologically, these structures were composed of numerous fine granules and were generally located near the neuronal cell bodies. They were demonstrated in silver preparations and, using neuron-specific enolase, tau and ubiquitin antibodies. Electron microscopy revealed an accumulation of large membranous vesicles thought to be derived from the smooth endoplasmic reticulum of axons, a few degenerative mitochondria and non-membrane-bound osmiophilic debris. Such pathological alterations were consistent with degenerative axonal changes or enlargements, although the pathogenesis was not clear. It should be emphasized that such axonal degeneration is frequently observed as a nonspecific reaction in the trigeminal ganglia in various diseases that cause trigeminal failure in cattle.

Animals↗

PubMed1996

Production of interleukin 10 during malaria caused by lethal and nonlethal variants of Plasmodium yoelii yoelii.

We investigated the induction of T-helper cell subsets during the course of lethal or nonlethal bloodstage Plasmodium yoelii 17X infection in C57BL/6 mice, which are relatively susceptible to these intraerythrocytic parasites. C57BL/6 mice infected with the nonlethal variant (PyNL) showed a moderate level of parasitemia and resolution of primary acute infection by week 4. Mice infected with the lethal variant (PyL) developed fulminating parasitemia and ultimately died. T-helper subset function was assessed during infection by determining the kinetics of in vitro production of the Th1-derived cytokine interferon-gamma (IFN-gamma) and the Th2-derived cytokine interleukin 10 (IL-10) by means of bioassay and enzyme-linked immunosorbent assay (ELISA), respectively. Spleen cells obtained from mice infected with PyL within the 1st week of infection produced high levels of IL-10 and IFN-gamma in response to malaria antigen. IL-10 also appeared in sera from PyL-infected mice at the same time at which the in vitro IL-10 response peaked. In contrast, spleen cells from mice infected with PyNL failed to produce IL-10 during the course of infection. CD4+ T-lymphocytes from mice infected with the lethal variant were a major source of IL-10, although non T-cells were also involved in the production of IL-10 during this malaria infection. In addition, the initial burst of IL-10 in response to malaria antigens was seen concomitantly with the production of IFN-gamma within the 1st week of infection. These results indicate that both Th1 and Th2 subsets of T-helper lymphocytes are activated during infection with the lethal variant of P. yoelii and support the contention of other investigators that a strong Th2 response early in infection is associated with the lethal outcome of malaria.

Animals↗

PubMed1996

Immunogenicity of Leucocytozoon caulleryi sporozoites and their reactivity with specific immune sera.

The immunogenicity of Leucocytozoon caulleryi sporozoites for chickens and their reactivity in vitro with specific immune sera were studied. Almost all of the chickens that had been immunized with the sporozoite antigens survived the sporozoite challenge. The degree of parasitemia observed in the immunized chickens was significantly lower than that found in the nonimmunized chickens. Specific antibodies against sporozoites were tested by the circumsporozoite precipitation (CSP) reaction. Antibodies were demonstrated in the sera of chickens that had been immunized with the sporozoite antigens or chickens that had recovered from a primary infection with L. caulleryi sporozoites. When viable mature sporozoites were incubated in vitro with serum from immune chickens, agglutination and a long, thread-like precipitate at one end of the sporozoite could be seen within a few minutes under a phase-contrast microscope. The effects of specific immune serum on the infectivity of sporozoites were examined by the sporozoite neutralization activity (SNA) test. Sporozoites that had been incubated in vitro with serum from immune chickens lost their infectivity to chickens. The CSP reaction and the SNA test in L. caulleryi infection were stage- and species-specific.

Animals↗

PubMed1996

Regulation of dopamine D2 receptor affinity by cholecystokinin octapeptide in fibroblast cells cotransfected with human CCKB and D2L receptor cDNAs.

Alteration in dopamine (DA) and/or cholecystokinin (CCK) transmission in the CNS may be of relevance for schizophrenia. Previous findings in striatal membranes give indications of a modulation of DA D2 receptor affinity by CCKB receptor activation. In the present study receptor binding studies were performed in a mouse fibroblast cell line (L-hD2l/CCK), expressing both human D2 receptors (long form, D2L) and human CCKB receptors, and binding sites for [3H]CCK-8S (sulfated CCK octapeptide), the D2 agonist [3H]NPA and the D2 antagonist [3H]raclopride were found and characterized in saturation and competition experiments. 1 nM of CCK-8 caused a significant 38% increase in the KD value of the D2 agonist [3H]NPA binding sites in the L-hD2l/CCK cell membranes. This change was blocked by the CCKB receptor antagonist PD 134308 (50 nM). Furthermore, 1 nM of CCK-8 increased the KD value of the D2 antagonist [3H]raclopride binding sites by 34% (P < 0.05) in the L-hD2l/CCK cell membranes. Control cells (L-hD2l cells) expressing D2L receptors showed no specific [3H]CCK-8S binding sites and no modulation by CCK-8 of the D2L receptors. These findings indicate a modulation of the D2L receptor affinity by activation of the CCKB receptor also when they are coexpressed in a fibroblast cell line. One possible explanation of these data may include a receptor-receptor interaction between the CCKB and D2L receptors.

Animals↗

PubMed1996

Effect of danazol on the immunocompetent cells in the eutopic endometrium in patients with endometriosis: a multicenter cooperative study.

OBJECTIVE: To assess the effects of danazol on immunocompetent cells, human leukocyte antigen (HLA) expression, and adhesion molecules in the eutopic endometrium of patients with endometriosis. DESIGN: Antigens were localized immunohistochemically in the endometria, before treatment and during treatment (2 months later). PARTICIPANTS: Ten patients with laparoscopically proven endometriosis who consented to participate in this study were treated with 400 mg/d of danazol for 4 months. Forty-two infertile patients without endometriosis or adenomyosis served as controls. RESULTS: Immunohistochemical analysis revealed significantly increased expression of the T cell subsets, macrophages, adhesion molecules, and HLA antigens in eutopic endometrium in patients with endometriosis compared with the infertile group. Treatment with danazol reduced the number of cells in T cell subsets, adhesion molecules, or HLA antigen expression, especially of gamma delta T cells, to 39.5% of the pretreatment value in patients with endometriosis. CONCLUSIONS: Danazol had an immunomodulatory effect on the autoimmune response in endometrium associated with endometriosis.

Adult↗

PubMed1996

Status of the coagulation and fibrinolytic systems in ovarian hyperstimulation syndrome.

OBJECTIVE: To elucidate characteristic changes of plasma hemostatic markers in ovarian hyperstimulation syndrome (OHSS) cycles. DESIGN: Prospective study. SETTING: The IVF-ET program of the Department of Obstetrics and Gynecology, The University of Akita, School of Medicine. PATIENTS: Forty cycles of 40 IVF patients, including 12 cycles in which a severe form of OHSS occurred. INTERVENTIONS: Blood samples were taken during IVF treatment to determine the levels of blood markers that reflect activation of the coagulation and fibrinolytic systems. MAIN OUTCOME MEASURES: Thrombin-antithrombin III complexes, plasmin-alpha 2 antiplasmin complexes, and other hemostatic markers related to the coagulation and fibrinolytic system activation. RESULTS: In the OHSS cycles, the levels of thrombin-antithrombin III and plasmin-alpha 2 antiplasmin complexes in the plasma began to rise within a few days after hCG administration and demonstrated significantly higher levels during the midluteal phase. In OHSS cycles with pregnancy, elevation of these markers continued for > or = 3 weeks after the onset of disease. There were some characteristic changes in OHSS cycles in other hemostatic markers, such as a decrease in the levels of antithrombin III and prekallikrein and shortened activated partial thromboplastin time. CONCLUSION: These data demonstrate the status of the coagulation and fibrinolytic systems in OHSS cycles and provide insight into the mechanism of activation in the hemostatic system.

Adult↗

PubMed1996

Benefit of in vitro fertilization treatment for endometriosis-associated infertility.

OBJECTIVE: To evaluate the effectiveness of IVF treatment in endometriosis-associated infertility. DESIGN: Nonrandom retrospective study. SETTING: Department of Gynecology and Obstetrics, Akita University School of Medicine. MAIN OUTCOME MEASURE(S): Cumulative pregnancy rate. PATIENT(S): One hundred eighteen infertile patients in whom diagnosis of endometriosis was established by laparoscopic examination. INTERVENTION(S): The prognoses of 60 patients (IVF group) who started IVF treatment within 6 months after laparoscopy were compared with those of 58 patients who were managed expectantly without IVF treatment during the same period. RESULT(S): The cumulative conception rates at 36 months after laparoscopy were 62% in the IVF group and 43% in the control group, and the difference was not significant (a log-rank test). For patients > or = 32 years of age, the conception rates were significantly higher in the IVF group (59% versus 29%). A relatively large but nonsignificant difference in the conception rate between the two groups was observed in patients with endometriosis at stages III or IV (52% versus 27%). CONCLUSION(S): In vitro fertilization treatment provides better prognosis in patients > or = 32 years of age and is recommended for such patients. The benefits of treatment appear to be greater in patients with more advanced stages of endometriosis.

Adult↗

PubMed1996

Attenuation of Eimeria caviae by selection for precocious development.

An attenuated line of Eimeria caviae was produced by selection for early maturation of oocysts during serial passage in guinea pigs. The prepatent period of the parasite was reduced from 11 to 6 days. Parasites of the precocious line and the parent strain were found in the crypts of the epithelial cells of caecum and colon and were morphologically indistinguishable. The period of development of type I, type II and type III merozoites of the E. caviae precocious line in guinea pigs was similar to that of the parent strain until the 3rd day. The time of the transition from gametocytes to oocysts was 2 days in both the precocious line and the parent strain. The maximum number of oocysts per gram of faeces and the pathogenicity of the precocious line were less than those of the parent strain.

Aging↗

PubMed1996

Perioperative respiratory management with fiberoptic bronchoscopy in pediatric living-related liver transplantation.

BACKGROUND: Perioperative respiratory complications have been one of the largest obstacles to pediatric management of pediatric liver METHODS: The roles of fiberoptic bronchoscopy in perioperative respiratory management of pediatric liver transplantation were studied retrospectively. RESULTS: In a group of 162 children who underwent pediatric living-related liver transplantation, 44 underwent 222 bronchoscopic procedures for diagnostic and therapeutic purposes during the perioperative period. Major indications for bronchoscopy were atelectasis/retention of airway secretion (n = 27), pneumonia (n = 19), pulmonary edema (n = 8), airway stenosis (n = 7), and airway bleeding (n = 6). Visualization of the airway was helpful in diagnosing respiratory complications; in seven infants, bronchoscopy revealed tracheobronchial stenosis that other diagnostic modalities failed to detect. In 16 of 19 patients with pneumonia, specimens taken by bronchoscopy were positive for specific pathogens. Bronchoscopy also proved to have significant therapeutic value, especially in airway cleaning; bronchial suctioning resulted in immediate reexpansion of the collapsed lung in 16 of 20 cases of atelectasis. No complications were noted other than severe hypoxia and bradycardia in one infant. CONCLUSIONS: Fiberoptic bronchoscopy is a safe and useful modality for perioperative respiratory management in pediatric liver transplantation.

Adolescent↗

PubMed1996

Orphan nuclear receptor ROR alpha gene: isoform-specific spatiotemporal expression during postnatal development of brain.

We analyzed expression of mouse orphan nuclear receptor ROR alpha during postnatal development of rodent brain. Using a riboprobe corresponding to the 3'-end of mROR alpha cDNA a peak of ROR alpha expression was observed at postnatal 16 day (P16) in the Purkinje cells of cerebellum, neurons of the thalamus and the olfactory bulb. The hippocampus was also shown to express ROR alpha with an earlier peak at P7. Expression in cell types other than the Purkinje cells appeared transient. On the other hand, when a probe to the 5'-end of mROR alpha cDNA was used, we observed patterns of ROR alpha expression that are different from those observed with the 3'-probe. No specific transcripts of ROR alpha were detected with the 5'-probe in the Purkinje cells until P16. Additionally, the relative level of the hybridization signals with the 5'-probe and the 3'-probe were different among the various brain regions. Together with the previous findings that ROR alpha comprises at least four isoforms which differ from one another in their N-terminal regions, these observations suggest that the spatiotemporal expression of ROR alpha is under isoform-specific regulation. The timing of its expression suggests that ROR alpha may be involved in regulation of postnatal maturation of specific classes of neurons.

Animals↗

PubMed1996

Stimulatory effect of zinc-chelating dipeptide on deoxyribonucleic acid synthesis in osteoblastic MC3T3-E1 cells.

Whether deoxyribonucleic acid (DNA) synthesis in osteoblastic MC3T3-E1 cells is stimulated by zinc, an activator of bone formation, was investigated in vitro. After subculture for 3 days, the cells were cultured for up to 3 days (72 h) with zinc sulfate or zinc-chelated dipeptide (beta-alanyl-L-histidinato zinc; AHZ) in the range of 10(-7) to 10(-5) M. The culture with zinc compounds (10(-5) M) produced a significant increase of cell number, DNA content, and protein concentration in the cells, as reported previously. The culture with zinc compounds (10(-6) and 10(-5) M) clearly stimulated DNA synthesis in the homogenate, when it was estimated by the incorporation of [3H]deoxythymidine 5'-triphosphate into the DNA in the homogenate of cells. The AHZ effect was greater than that of zinc sulfate. The culture together with cycloheximide (19(-6) M) completely abolished the zinc compounds (10(-5) M)-induced increase of DNA synthesis in the cells, suggesting that the zinc compound effect is based on a newly synthesized protein component. Moreover, when zinc sulfate (10(-7) and 10(-6) M) or AHZ (10(-8) to 10(-5) M) was added into the reaction mixture with the homogenate of cells cultured without zinc compounds, the DNA synthesis was clearly increased. The effect of addition of zinc compounds (10(-6) M) on the DNA synthesis was completely inhibited by the presence of staurosporine (10(-8) M), an inhibitor of protein kinase C, or okadaic acid (10(-7) M), an inhibitor of protein phosphatase. The present study demonstrates that zinc compounds have a stimulatory effect on DNA synthesis in osteoblastic cells.

Animals↗

PubMed1996

Five new anthocyanins, ternatins A3, B4, B3, B2, and D2, from Clitoria ternatea flowers.

Five new ternatins 1-5 have been isolated from Clitoria ternatea flowers, and the structures have been determined by chemical and spectroscopic methods as delphinidin 3-malonylG having 3'-GCG-5'-GCG, 3'-GCG-5'-GC, 3'-GCGCG-5'-GC, 3'-GCGC-5'-GCG, and 3'-GCGC-5'-GC side chains, respectively, in which G is D-glucose and C is p-coumaric acid. Pigment 1 had symmetric 3',5'-side chains. Compounds 3 and 4 are structural isomers. These ternatins were shown to form an intramolecular stacking between the aglycon ring and the 3',5'-side chains in solution.

Anthocyanins↗