Biomedical subjects

M Masuda

Publications and source records attributed to M Masuda.

At least 109 records · Page 6Linked to original sources

PubMed2000

Haemophilus parainfluenzae antigen and antibody in children with IgA nephropathy and Henoch-Schönlein nephritis.

Although the pathogenesis of immunoglobulin A (IgA) nephropathy and Henoch-Schönlein nephritis (HSN) remains uncertain, there is substantial evidence that they are immune complex-mediated diseases. Recently, Haemophilus parainfluenzae antigens were shown in the glomerular mesangium of adult patients with IgA nephropathy, and greater levels of IgA antibody against H parainfluenzae were also shown in the sera of adult patients with IgA nephropathy. The present study was performed to detect H parainfluenzae antigens and antibody against H parainfluenzae in children with IgA nephropathy and HSN. H parainfluenzae antigens in the mesangium were examined by indirect immunofluorescence, and antibody against H parainfluenzae was examined by enzyme-linked immunosorbent assay. Diffuse global staining of the mesangium with rabbit antisera against H parainfluenzae was shown in 10 of the 32 patients (31%) with IgA nephropathy and 12 of the 34 patients (35%) with HSN. Conversely, only 2 of the 47 patients (4%) with other renal diseases showed staining of glomeruli with rabbit antisera against H parainfluenzae (IgA nephropathy versus other renal diseases, P = 0.003; HSN versus other renal diseases, P = 0.0006). Patients with IgA nephropathy and those with HSN showed significantly greater levels of plasma IgA1 antibody against H parainfluenzae than patients with other renal diseases (IgA nephropathy versus other renal diseases, P = 0.008; HSN versus other renal diseases, P = 0.025). These findings suggest that H parainfluenzae has a role in the cause of these two conditions in a subset of patients.

Adolescent↗

PubMed2000

Whole blood prothrombin time using diluted tissue factor is shortened in spontaneous hypertensive rats.

Clinical screening tests for blood coagulation that use plasma as samples cannot estimate the participation of platelets, leukocytes, and erythrocytes in blood coagulation system. We developed an assay to evaluate the total coagulation ability of blood and whole blood prothrombin time (WPT) using the principle of prothrombin time with the diluted-tissue factor as a trigger and a newly developed apparatus, STA, viscosity change detection system (electromagnetic clot detection). The activation of platelets by Ca ionophore shortened WPT and increased the expression of CD62P on the platelet surface. WPTs in citrated blood of spontaneous hypertensive rats (SHR) were significantly shorter than those of controls, Wistar Kyoto rats (WKY). Plasma levels of thrombin-antithrombin III (TAT) in SHR were significantly higher than those of WKY. Moreover, WPT and TAT levels were significantly correlated. Based on these results, WPT was found to be useful to estimate the activation of blood coagulation in whole blood.

Animals↗

PubMed2000

[A SHV-derived extended-spectrum beta-lactamase (SHV-12) produced by an Escherichia coli recovered from wound abscess in post operative case with rectal carcinoma].

A 62-year-old woman admitted for rectal carcinoma suffered from a post-operative bacterial infection. Oxy-imino-beta-lactams including cefotiam (CTM) and cefozopran (CZOP) were prescribed for this case, but the patient developed a wound abscess followed by peritonitis. She recovered from the bacterial infection after drainage and recurrent washing of the abscess. An ephemeral aggravation of infectious signs was observed just after creation of an artificial anus, and CZOP was again administered, and no evident bacterial infection occurred. The patient recovered, then was followed as an outpatient to date. A CAZ-resistant (MIC, > 16 micrograms/ml) E. coli was recovered from pus of her wound abscess. Since the CAZ-resistance decreased (MIC, 64 micrograms/ml-->0.13 microgram/ml) by the presence of clavulanate (CVA) in this isolate, this strain was speculated to be an extended spectrum beta-lactamase (ESBL) producer at an early stage of infection. A similar strain was also isolated from the feces. Therefore, we immediately took measures to block the nosocomial spread of this microorganism, and we succeeded in preventing a nosocomial outbreak of this strain. It was later confirmed by PCR analysis and DNA sequencing analysis that this CAZ-resistant E. coli strain produces an ESBL (SHV-5-2a = SHV-12). This is the first report of a case of infection with SHV-derived ESBL producing E. coli strain in Japan. We are concerned that further dissemination of this kind of microorganism might occur in the near future also in Japan, as it has been widely observed in European countries and the US. We believe that it will be very important to distinguish the type of beta-lactamases for rigorous bacterial infection control with the prudent use of antibiotics. In other words, we in Japan must recall that various gram-negative bacterial species that produce TEM-, SHV-derived ESBLs, Toho-1, AmpC, or IMP-1 are already widespread. Thus, we should take this fact into consideration when we do antibiotic susceptibility tentings and interpretation of the results for promotion of accurate chemotherapy.

Abscess↗

PubMed2000

Genetic studies with the fission yeast Schizosaccharomyces pombe suggest involvement of wee1, ppa2, and rad24 in induction of cell cycle arrest by human immunodeficiency virus type 1 Vpr.

Accessory protein Vpr of human immunodeficiency virus type 1 (HIV-1) arrests cell cycling at G(2)/M phase in human and simian cells. Recently, it has been shown that Vpr also causes cell cycle arrest in the fission yeast Schizosaccharomyces pombe, which shares the cell cycle regulatory mechanisms with higher eukaryotes including humans. In this study, in order to identify host cellular factors involved in Vpr-induced cell cycle arrest, the ability of Vpr to cause elongated cellular morphology (cdc phenotype) typical of G(2)/M cell cycle arrest in wild-type and various mutant strains of S. pombe was examined. Our results indicated that Vpr caused the cdc phenotype in wild-type S. pombe as well as in strains carrying mutations, such as the cdc2-3w, Deltacdc25, rad1-1, Deltachk1, Deltamik1, and Deltappa1 strains. However, other mutants, such as the cdc2-1w, Deltawee1, Deltappa2, and Deltarad24 strains, failed to show a distinct cdc phenotype in response to Vpr expression. Results of these genetic studies suggested that Wee1, Ppa2, and Rad24 might be required for induction of cell cycle arrest by HIV-1 Vpr. Cell proliferation was inhibited by Vpr expression in all of the strains examined including the ones that did not show the cdc phenotype. The results supported the previously suggested possibility that Vpr affects the cell cycle and cell proliferation through different pathways.

Cell Cycle↗

PubMed2000

Serum-free coculture of stromal and epithelial cells from benign prostatic hyperplasia with keratinocyte growth factor.

We developed a serum-free coculture model of benign prostatic hyperplasia (BPH) to clarify whether stromal cells stimulate growth of epithelial cells from BPH tissues. Epithelial and stromal cells from freshly isolated BPH tissue were cultured separately in defined serum-free WAJC 404/RPMI 1640 medium supplemented with insulin, transferrin, selenium, hydrocortisone, bovine serum albumin, epidermal growth factor, basic fibroblast growth factor and keratinocyte growth factor. (3)H-Tdr incorporation into epithelial cells and stromal cells was used as a measure of proliferation. When epithelial cells were cocultured with stromal cells, (3)H-Tdr incorporation into epithelial cells was increased in comparison to that in epithelial cells cultured alone. Dihydrotestosterone significantly increased this effect. It is likely that the in vitro coculture model reported here will be useful for isolating and understanding stromal cell-derived paracrine growth factor(s).

Cell Division↗

PubMed2000

Functional properties of circulating and transmigrated neutrophils in a rat peritonitis model.

Using a rat peritonitis model, we examined the pattern of expression of adhesion molecules and H2O2 productivity of neutrophils by indirect immunofluorescence and flow cytometry. H2O2 production in blood neutrophils was significantly increased after peritonitis induction. The expression of CD11b and CD18 antigens on blood neutrophils was also significantly increased after peritonitis induction. In contrast, H2O2 production in peritoneal neutrophils was significantly lower than that in blood neutrophils. The expression of CD11b and CD45 antigens on peritoneal neutrophils was significantly higher than on blood neutrophils. Although no function has been assigned to LFA-1 on neutrophils, the expression of LFA-1 (CD11a/CD18) on peritoneal neutrophils was significantly decreased.

Animals↗

PubMed2000

Pathologic 'fused gland' as a prognostic factor for prostate cancer.

We examined the significance of a pathologic 'fused gland' according to the WHO-Mostofi classification for predicting prognosis in hormonally treated prostate cancer. Of 284 newly diagnosed patients receiving hormone therapy, 60 patients had specimens with no 'medullary' or 'column-cord' elements. Twenty-five of these had a 'fused gland', while 35 did not. Survival of these patients was analyzed. Cause-specific survival of the patients with no medullary or column-cord elements showed a significantly better prognosis compared to others. Furthermore, the patients whose specimens contained a 'fused gland' component had significantly poorer survival than those without that component, suggesting that the 'fused gland' component is a poor prognostic factor for survival in patients with hormonally treated prostate cancer.

Adenocarcinoma↗

PubMed2000

Liquid chromatography mass spectrometric analysis of ouabainlike factor in biological fluid.

Ouabainlike factor (OLF), assayed as ouabainlike immunoreactivity (OLI), is a probable endogenous digitalislike factor (EDLF). Liquid chromatography/mass spectrometry (LC/MS) is one of the most highly sensitive tools for obtaining structural information regarding low-molecular weight materials in a target compound, and to measure the concentrations of these materials. We have previously reported that OLI can be isolated from the culture supernatant of the rat pheochromocytoma cell line, PC12, by several reverse-phase chromatography and LC/MS techniques. The present study was performed to characterize OLF from biological fluids such as plasma and culture supernatant of PC12 cells by LC/MS. The previous applications of LC/MS to OLI in plasma have been limited to structural identification at the final stages of isolation, in which the starting volume of plasma has been over 10 I. In the present study, we tried to minimize the volume of plasma, and to develop a new preclearing step to gain adequate LC/MS characterization using MS/MS analysis. The plasma was acidified, and OLI was purified by ODS column chromatography. OLI in chromatographic fractions from plasma was assayed by a sensitive enzyme-linked immunosorbent assay for ouabain. After Sep-Pak treatment and two rounds of ODS column chromatography, OLI was identified from 80 ml of plasma. The structure of the purified OLI was identical to authentic ouabain and digoxin, as assessed by LC/MS. In conclusion, we identified the chemically or structurally clarified ouabain and digoxin as the circulating form in plasma by LC/MS.

Animals↗

PubMed2000

Inhibitory effect of central calcitonin-gene related peptide (CGRP) on pancreatic secretion in conscious rats.

The inhibitory effect of central administration of calcitonin-gene related peptide (CGRP) on pancreatic secretion stimulated by bile-pancreatic juice diversion was determined in conscious rats. Rats were prepared with separate cannulae for draining bile and pancreatic juice and with a duodenal cannula and an extrajugular vein cannula. In addition, another cannula was stereotactically implanted into the left lateral cerebral ventricle. Rats were placed in restraint cages and experiments were conducted 4 d after the operation without anesthesia. An injection of CGRP (1 nmol/10 microl) into the left lateral cerebral ventricle (i.c.v.) inhibited pancreatic secretion as well as cholecystokinin (CCK) release induced by bile-pancreatic juice diversion. Intravenous infusion of alpha- and beta-adrenergic receptor antagonist, phentolamine and propranolol did not reverse the inhibition of pancreatic secretion. Intravenous infusion of CGRP did not affect pancreatic secretion or plasma CCK concentrations. The inhibitory action of central CGRP (i. c.v.) on pancreatic secretion and CCK release stimulated by bile-pancreatic juice diversion is partially mediated by an alpha-adrenergic mechanism, although its precise mechanism has not been elucidated.

Adrenergic alpha-Antagonists↗

PubMed2000

Mechanism of delayed gastric emptying in naturally occurring CCK-A receptor gene knockout (OLETF) rats.

We recently found a specific strain of rats (OLETF rats) in which CCK-A receptor gene expression is lacking because of a genetic abnormality. As delayed gastric emptying has been reported in this strain, we examined its mechanism. A liquid gastric load containing phenol red was administered using an orogastric tube into the stomach in OLETF and control (LETO) rats. The stomach was removed 0, 15, 30 and 45 min after meal ingestion and the content of phenol red was measured to estimate the rate of gastric emptying. Pretreatment of reserpine enhanced gastric emptying in both strains. A tenfold dose of reserpine was required in OLETF rats to induce a similar effect to LETO rats. The plasma noradrenalin level was significantly higher in OLETF than LETO rats. When the smooth muscle of the stomach was isolated and contraction in vitro was examined, the smooth muscle functions were not deteriorated in OLETF rats. The thickness of muscle determined by hematoxylin-eosin staining was not different between strains. It is suggested that the delayed gastric emptying in OLETF rats may be due to increased sympathetic nerve function.

Animals↗

PubMed2000

Association of CTLA-4 gene A/G polymorphism in Japanese type 1 diabetic patients with younger age of onset and autoimmune thyroid disease.

OBJECTIVE: We studied the association between type 1 diabetes with autoimmune thyroid disease (AITD) and A/G allele polymorphism in exon 1 of the CTLA-4 gene in a Japanese population. RESEARCH DESIGN AND METHODS: We studied 74 Japanese type 1 diabetic patients with or without AITD and 107 normal subjects to identify the association between CTLA-4 polymorphism and type 1 diabetes using polymerase chain reaction-restriction fragment length polymorphism analysis. RESULTS: The frequency of the CTLA-4 G allele differed significantly between the type 1 diabetic patients (61%) and the normal control subjects (48%) (P = 0.016). The difference in the CTLA-4 G allele became greater between patients with a younger age of onset of type 1 diabetes (age at onset <30 years) and the normal control subjects (64% and 48%, respectively). However, the frequency of the CTLA-4 G allele did not differ between type 1 diabetic patients with younger and older age of onset (64% vs. 57%). The G allele frequencies in the patients with younger-onset type 1 diabetes and AITD increased more than in the control patients (P = 0.025). These differences reflected a significant increase in the frequency of G/G genotype--that is, 54% in those with younger-onset type 1 diabetes and AITD, 39% in those without AITD, and 28% in control subjects. CONCLUSIONS: An association was detected between the CTLA-4 gene polymorphism and younger-onset type 1 diabetes with AITD. The G variant was suggested to be genetically linked to AITD-associated type 1 diabetes of younger onset in this apanese population. The defect in these patients presumably lies in a T-cell-mediated autoimmune mechanism.

Abatacept↗

PubMed2000

Enhancement of human endometrial stromal decidualization by bestatin, an aminopeptidase-N inhibitor.

We have re-evaluated the effects of bestatin, an aminopeptidase-N (CD13) inhibitor, on in vitro decidualization of normal human endometrial stromal cells by using an in vitro decidualization activity assay. Bestatin did not show any effects on the viability of both the decidualizing stromal cells co-stimulated with 8-Br-cAMP and bestatin and the 8-Br-cAMP-induced decidualized stromal cells, or on prolactin release from the decidualized stromal cells. However, bestatin dose-dependently enhanced prolactin release from the decidualizing stromal cells co-stimulated with 8-Br-cAMP and bestatin. These results indicate that bestatin enhances cAMP-mediated decidualization of human endometrial stromal cells and suggests that membrane aminopeptidase-N in the human endometrium is involved in the regulation of endometrial differentiation by inhibiting cAMP-mediated decidualization signals in endometrial stromal cells.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed2000

Production and physiological function of granulocyte colony-stimulating factor in non-pregnant human endometrial stromal cells.

Effects of granulocyte colony-stimulating factor (G-CSF) on proliferation and differentiation of normal human endometrial stromal cells were investigated in an in vitro decidualization culture of stromal cells. Unstimulated stromal cells secreted little prolactin and G-CSF, whereas 8-Br-cAMP-stimulated stromal cells secreted higher levels. There was no relationship, however, between the levels of prolactin and G-CSF secreted from the stimulated cells. Detectable levels of prolactin secretion were not found in two of six stromal cell cultures stimulated with 8-Br-cAMP; however, these two culture supernatants contained high concentrations of G-CSF. Co-stimulation of the stromal cells with 8-Br-cAMP and G-CSF enhanced prolactin secretion from the stimulated cells in a G-CSF concentration-dependent manner without any change in viable cell numbers. However, G-CSF did not affect prolactin secretion or viable cell numbers of 8-Br-cAMP-stimulated decidualized cells. These results indicate that G-CSF enhances cAMP-mediated decidualization of human endometrial stromal cells in an autocrine or paracrine fashion.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed2000

[Concentration and individual variation of inorganic ions in unstimulated whole saliva].

The purpose of this study was to know the range of fluctuation of inorganic ion concentrations and pH in the unstimulated whole saliva and also to know if there is individual difference between subjects which surpasses this fluctuation. Whole saliva was collected seven times between 9 AM and 4 PM at one- or two-hour intervals from ten subjects aged 24 to 27 years. The inorganic ion concentrations and pH were analyzed using an ion chromatogram and a pH electrode respectively. The coefficients of variation of the inorganic ion concentrations were between 24% to 43%, indicating that it is misleading to interpret only one data obtained as the true value of the subject. However, statistical analysis showed that the pH value and inorganic ion concentrations were significantly different among many of the subjects, in spite of the fluctuation within individual subjects. On the other hand, most of the correlations were statistically significant among pH and each of the inorganic ions. Above all, the correlation coefficient between potassium and phosphate ion concentrations was high. In contrast, the sodium ion did not have any significant correlation with most of the other ions. The results were discussed in reference to the salivary secretion mechanism.

Adult↗

PubMed2000

Analysis of hepatocellular carcinoma fed by internal thoracic artery

Purpose: The purpose of this study was to elucidate the clinical features of hepatocellular carcinoma (HCC) fed by the internal thoracic artery (ITA). Methods: In seven patients HCC fed by the ITA was confirmed by digital subtraction angiography. The number of previous transcatheter arterial embolization (TAE), the period from the first TAE to TAE of the ITA, tumor location, tumor size, and occlusion of the hepatic artery (HA) and other collateral vessels were explored in each case. Results: The HCCs were located in S4 of the liver (n = 5) and in S8 (n = 1) and were fed by the right ITA and one nodule in S2-3 was fed by the left ITA. Tumor size was 3-10 cm. The number of previous TAE of the HA ranged from 2 to 12. The period from the first TAE to TAE of the ITA was 3-53 months. Angiography of these patients showed occlusion of the HA in six cases, and of the extrahepatic collaterals including the inferior phrenic artery (IPA) in five cases, intercostal artery (ICA) in one case, and epicholedocal artery (EPA) in one case. Conclusion: The ITA often supplies HCC located in the anterior superior region of the liver under the diaphragm; there can be long-term survival with repeated TAE and occlusion of HA.

Journal Article↗

PubMed2000

[Testicular sarcoidosis].

We report a rare case of testicular sarcoidosis. A 68-year-old man was admitted for detailed examination of uveitis and swelling of the testes. A chest X-ray film and computed tomographic scans disclosed ground-glass shadows in the lower fields of both lungs with mediastinal lymphadenopathy. Ga scintigram showed pronounced accumulations in the testes, hilum, and mediastinum. Transbronchial lung and testicular biopsy specimens demonstrated noncaseating epithelioid granulomas, thus confirming the diagnosis of sarcoidosis with testicular involvement. The patient was followed up without systemic steroids. A review of the world literature found only 12 reported cases of clinically evident testicular sarcoidosis.

Aged↗

PubMed2000

Delineation of the frequently deleted region on chromosome arm 13q in B-cell non-Hodgkin's lymphoma.

The loss of a specific chromosomal region provides a clue to the elucidation of the putative tumor suppressor gene implicated in the pathogenesis and progression of tumors. To delineate the specific region(s) involved in lymphomagenesis, we performed a survey of loss of heterozygosity for 11 polymorphic microsatellite loci scattered on variable chromosome arms. We examined 20 primary lymphoma samples, including both indolent and aggressive B-cell non-Hodgkin's lymphoma (B-NHL) and Hodgkin's disease (HD), and found a significant number of B-NHLs with loss of genetic material on chromosome arm 13q at the RB1 locus (50%; 4 of 8 informative cases for the RB1 locus). To specify the 13q deletion and to narrow the critical deleted region, we examined the same 20 lymphomas by intensive microsatellite mapping analysis using 12 microsatellite markers, mapping from 13q12.3 to 13q14. We confirmed the frequent 13q14 deletion to be in the vicinity of the RB1 locus (50% of the informative NHLs for at least 1 of 12 microsatellite loci; 5 of 10 aggressive NHLs and 2 of 4 indolent NHLs, but none of 6 HDs) and determined a subchromosomal region deleted in lymphoma on 13q14 defined by D13S164-D13S273, which is an overlapped region frequently lost in chronic lymphocytic leukemia. Taken together, our data indicate that the 13q alterations are present in a wide variety of NHLs including both indolent and aggressive B-NHLs, suggesting that loss of genetic material at chromosome band 13q14 may play an important role in the formation or development of a wide variety of mature lymphoid malignancies.

Adult↗

PubMed2000

Linkage of autosomal recessive hereditary spastic paraplegia with mental impairment and thin corpus callosum to chromosome 15A13-15.

To date, three loci for autosomal recessive hereditary spastic paraplegia (ARHSP) linked to chromosomes 8p12-q13, 16qter, and 15q13-15 have been characterized. We have clinically characterized 13 Japanese ARHSP families and performed genetic linkage analyses. All 13 families were classified as having the "complicated" form, which manifests with mental impairment and thin corpus callosum. Linkage to the 8p12-q13 and 16qter loci was excluded, although 10 of the 13 families showed marker data consistent with linkage to the 15q13-15 locus. The multipoint LOD score of the 10 families linked to chromosome 15 was above 9.00 in the 3-centimorgan segment flanked by D15S994 and D15S659, with a maximum multipoint LOD score of 9.68 at a position 1.2 centimorgans telomeric from D15S994 to D15S659. We have shown that ARHSP with thin corpus callosum, a subtype of recessive spastic paraplegia, maps to chromosome 15q13-15.

Adolescent↗