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Dive into the research topics where Misao Sakumoto is active.

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Featured researches published by Misao Sakumoto.


The Journal of Urology | 1995

Testicular Injury Induces Cell-Mediated Autoimmune Response to Testis

Yasuki Sakamoto; Tetsuro Matsumoto; Yoshimitsu Mizunoe; Masashi Haraoka; Misao Sakumoto; Joichi Kumazawa

Studies on testis autoimmunity are needed for a better understanding of immunological male infertility. Evidence has accumulated that the delayed type hypersensitivity (DTH) response plays a key role in the induction and/or maintenance of experimental autoimmune orchitis (EAO), an animal model for human immunological male infertility or aspermatogenesis. We report here that an antigen-specific DTH response to autologous testicular cells (TC) could be induced by bilateral testicular injury (trauma) in mice. Pretreatment of traumatized mice with a high dose of cyclophosphamide (CY) enhances the DTH response in a dose-dependent manner. The DTH response induced by testicular injury reaches its peak on the ninth day. We have shown that the local passive transfer of the footpad reaction to normal recipients by T cells further defines the DTH reaction. These characteristics resemble those of the previously reported DTH response to syngeneic TC induced by subcutaneous immunization with viable syngeneic crude TC. Our present injury model mimics clinical testicular trauma; therefore, this testicular injury model can be very useful in studying the immunological mechanism of EAO and of human immunological male infertility.


Dermatology | 1997

Prevention of Catheter-Associated Urinary Tract Infection by Meatal Disinfection

Tetsuro Matsumoto; Misao Sakumoto; Koichi Takahashi; J. Kumazawa

The incidence of catheter-associated urinary tract infections (UTIs) becomes higher with prolongation of the indwelling period of a catheter. As to the entry of bacteria, ascending UTIs have now attracted attention. In the present study. the metal area was examined bacteriologically and the possibility to use antiseptics for blocking the route of developing infections was investigated. The subjects included 72 patients with an indwelling, urethral catheter inserted post-operatively. These patients were divided into three groups treated with once or twice daily application of povidone-iodine or once daily application of povidone-iodine cream. In these groups, the relation between changes in isolation of bacteria from the meatal area and the incidence of UTI was evaluated. It was found that reduction in bacterial count by antisepsis is effective to prevent ascending UTIs. Moreover, once daily application of povidone-iodine was proven to be effective in male patients. The effective antisepsis in females was twice daily application of povidone-iodine.


Chemotherapy | 1994

Enhanced chemiluminescence response of polymorphonuclear leukocytes by new quinolone antimicrobials.

Shuta Kubo; Tetsuro Matsumoto; Koichi Takahashi; Masashi Haraoka; Masatoshi Tanaka; Misao Sakumoto; Yasuki Sakamoto; Joichi Kumazawa

Some of the many antimicrobial agents (beta-lactams, macrolides, aminoglycosides, tetracyclines, new quinolones; NQs) were reported to have a bactericidal or bacteriostatic effect cooperating with host defense mechanisms including polymorphonuclear neutrophils (PMNs). We investigated the effect of new quinolone antimicrobials on chemiluminescence (CL) response of human PMNs. Among many NQs, we chose ofloxacin, lomefloxacin, fleroxacin, sparfloxacin, AM-1155, NM-394, Q-35, Y-26611 and T-3761. Twenty-five or 100 micrograms/ml of fleroxacin and ofloxacin enhanced luminol-dependent CL response of PMNs up to 1.5-2.0 times compared to the drug free condition. Other antimicrobial agents, however, inhibited CL response. This suggested that fleroxacin and ofloxacin were more efficient in the treatment of bacterial infections with respect to the interaction between antimicrobials and PMNs.


Chemotherapy | 1996

Fleroxacin Enhancement of Superoxide Production by Polymorphonuclear Leukocytes: The Role of Protein Kinases

Tetsuro Matsumoto; Koichi Takahashi; Tatsuo Nagafuji; Shuta Kubo; Misao Sakumoto; Osamu Mochida; Yasuki Sakamoto; Yoshimitsu Mizunoe; Joichi Kumazawa

New quinolone (NQ) antimicrobials may influence the functions of polymorphonuclear leukocyes (PMNs). Fleroxacin (FLRX), one of the newer NQs which has a long half-life in blood and a strong bactericidal effect, was examined for its influence on superoxide production by PMNs. Augmentation of superoxide production by PMNs when stimulated with phorbol myristate acetate (PMA) and formyl-methionyl-leucyl-phenylalanine (fMLP) was observed following the addition of 25, 50, 100 and 200 micrograms/ml of FLRX. In addition, the effects of staurosporine and H-7, inhibitors of protein kinase C (PKC), and of genistein, a tyrosine kinase (TK) inhibitor, on FLRX-enhanced superoxide production were examined. Superoxide production augmented by FLRX was diminished by the addition of staurosporine and H-7, when PMNs were stimulated with PMA, and by the addition of genistein, when PMNs were stimulated with fMLP. These results suggest that FLRX augments superoxide production by PMNs through enhancing the activities of phosphorylation by PKC or TK within the signal transduction pathway in PMNs.


Chemotherapy | 1998

Preventive Effect of Dapsone on Renal Scarring following Mannose-Sensitive Piliated Bacterial Infection

Osamu Mochida; Tetsuro Matsumoto; Yoshimitsu Mizunoe; Misao Sakumoto; Junji Abe; Joichi Kumazawa

Renal scarring has been thought to occur in the later stages of chronic pyelonephritis. We previously reported that mannose-sensitive (MS) piliated bacteria promoted renal scarring, which was prevented by antioxidants. The preventive effect of diaphenylsulfone (dapsone), which has a scavenging activity on active oxygen species, on renal scarring was examined. Female Sprague-Dawley rats were inoculated with clinical isolates of Serratia marcescens which had both MS and mannose-resistant pili or with recombinant strains which had MS pili on their surface; they were then administered 20 mg/kg of dapsone or not. Dapsone significantly suppressed scarring following infection of the kidney. The bacterial counts in the kidneys were not different in dapsone-treated and nontreated rats. We conclude that dapsone is effective in preventing renal scarring, and it is suggested that the clinical use of this drug may prevent renal scar formation following pyelonephritis.


Nephron | 1995

Preventive Effect of Ulinastatin on Renal Scarring in Rat Model of Pyelonephritis Induced by Direct or Ascending Infection with Serratia marcescens or Escherichia coli

Tetsuro Matsumoto; Masashi Haraoka; Yoshimitsu Mizunoe; Koichi Takahashi; Shuta Kubo; Misao Sakumoto; Masatoshi Tanaka; Joichi Kumazawa

Renal scarring is considered to be a characteristic of reflux nephropathy. The effects of ulinastatin, a strong inhibitor of polymorphonuclear leukocyte elastase, on renal scarring following direct parenchymal or intravesical ascending infection by Serratia marcescens or Escherichia coli were determined. Four days of treatment with ulinastatin initiated 2 or 5 days after infection prevented renal scarring. Doses of 1,000-4,000 units/kg inhibited renal scar formation, but 8,000 units/kg did not. These results suggest that it may be possible to limit renal scar formation in pyelonephritis by the use of an appropriate pharmacologic agent.


Chemotherapy | 1995

Effect of Ebselen on Renal Scarring in Rats following Renal Infection

Masashi Haraoka; Tetsuro Matsumoto; Yoshimitsu Mizunoe; Koichi Takahashi; Shuta Kubo; Yasuhiro Koikawa; Masatoshi Tanaka; Yasuki Sakamoto; Misao Sakumoto; Tatsuo Nagafuji; Joichi Kumazawa

Renal scarring, which occurs following refluxing pyelonephritis, is considered to be involved in the development of reflux nephropathy. Prevention of renal scar formation requires immediate initiation of antimicrobial treatment; treatment delay results in renal scarring. We demonstrate that Ebselen, an antioxidant agent, given at a dose of 15 mg/kg twice a day prevents renal scarring in rats following direct renal parenchymal bacterial inoculation. In addition, using an ascending pyelonephritis model, which clinically resembles refluxing pyelonephritis in humans, we show that when initiation of antimicrobial treatment was delayed, coadministration of Ebselen prevents renal scar formation. These results show that Ebselen is effective in preventing renal scarring and suggest that the clinical use of this drug may prevent renal scar formation following pyelonephritis and progression to reflux nephropathy.


Journal of Infection and Chemotherapy | 1998

Urinary Concentrations of Cytokines in Patients with Pyelonephritis and Cystitis

Misao Sakumoto; Tetsuro Matsumoto; Osamu Mochida; Koichi Takahashi; Shunji Sakuma; Joichi Kumazawa

We measured concentrations of interleukin-1β,-6 and-8, and tumor necrosis factor-α in the urine and blood of patients with urinary tract infections. We also examined the relationships between the severity of pyuria and concentrations of interleukin-6 or interleukin-8 in urine. Concentrations of interleukin-6 and-8 were significantly higher in the urine of patients with urinary tract infections than that of healthy subjects or patients with fever unrelated to the urinary tract infection. A close relationship was observed between the severity of pyuria and the concentration of interleukin-8. Concentrations of interleukin-6 and-8 in the blood were higher in patients with pyelonephritis than in patients with cystitis. These results suggest that the interleukin-6 and-8 were generated in the urinary tract during pyelonephritis and cystitis, and that the interleukin-8 induced leukocyte influx into the urine.


Nephron | 1997

Renal scarring by mannose-sensitive adhesin of Escherichia coli type 1 pili.

Yoshimitsu Mizunoe; Tetsuro Matsumoto; Misao Sakumoto; Shuta Kubo; Osamu Mochida; Yasuki Sakamoto; Joichi Kumazawa

Most Escherichia coli isolates from patients with pyelonephritis possess both pap (mannose-resistant) pili and type 1 (mannose-sensitive) pili. In the experimental pyelonephritis model of rats, the mannose-sensitive-piliated strain caused severe renal scarring, whereas the mannose-resistant or nonpiliated strain did not. Type 1 pili consist of several subunits; one major subunit and other minor subunits. One of the minor subunits, adhesin, is responsible for mannose-sensitive adhesion to eukaryotic cells. The role of adhesin was examined in scar formation after infection with a newly constructed adhesin-deficient mutant which has pilus structure but cannot agglutinate guinea pig erythrocytes. A mutant plasmid, pYMZ84, containing a deletion in the adhesin gene of type 1 pili, failed to agglutinate guinea pig erythrocytes even though the bacteria expressed pili morphologically indistinguishable from those produced by plasmid pSH2, carrying the intact genes for the type 1 pili. E. coli harboring pYMZ84 caused negligible or minimal renal scarring, whereas E. coli harboring pSH2 caused severe renal scarring in rats. These data suggest that the mannose-sensitive adhesin of type 1 pili stimulates renal scarring.


International Journal of Urology | 1998

Reduced Chlamydial Infection and Gonorrhea among Commercial Sex Workers in Fukuoka City, Japan

Masatoshi Tanaka; Hiroshi Nakayama; Misao Sakumoto; Koichi Takahashi; Tatsuo Nagafuji; Kohei Akazawa; Joichi Kumazawa

Background: Until recently, epidemiologic studies of sexually transmitted diseases (STDs), including human immunodeficiency virus type‐1 (HIV‐1) infection, amongjapanese female commercial sex workers and their patterns of condom use have been rare. We investigated trends in STDs among female commercial sex workers and their condom use patterns in Fukuoka, Japan, from 1990 through 1995.

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Yoshimitsu Mizunoe

Jikei University School of Medicine

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