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M Sakumoto

Publications and source records attributed to M Sakumoto.

At least 19 recordsLinked to original sources
PubMed1998

Reduced chlamydial infection and gonorrhea among commercial sex workers in Fukuoka City, Japan.

BACKGROUND: Until recently, epidemiologic studies of sexually transmitted diseases (STDs), including human immunodeficiency virus type-1 (HIV-1) infection, among Japanese 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. METHODS: The study group consisted of 1218 female commercial sex workers who attended an STD clinic to undergo screening for major STDs including chlamydial infection, gonorrhea and HIV-1 infection from 1990 through 1995. Endocervical smear specimens were taken from the women to detect Chlamydia trachomatis and Neisseria gonorrhoeae, and blood samples were obtained for the serologic diagnosis of HIV-1. Also, the commercial sex workers were interviewed concerning their condom use patterns. RESULTS: The annual infection and detection rates of C. trachomatis declined significantly from 58.1% in 1990 to 46.2% in 1995 and from 16.3% in 1990 to 10.0% in 1995, respectively, while the annual infection and detection rates of N. gonorrhoeae also declined significantly from 13.2% in 1990 to 3.5% in 1995 and from 1.5% in 1990 to 0.4% in 1995, respectively. None were found to be seropositive for HIV-1 during the 6-year period. The proportion of commercial sex workers using condoms significantly increased during 1992-1993 and 1994-1995 periods, as compared with the 1990-1991 period. CONCLUSION: Reductions in the prevalence of major STDs among female commercial sex workers may be related to an increase in the frequency of condom use.

Adolescent↗
PubMed1998

Reduced clinical efficacy of pazufloxacin against gonorrhea due to high prevalence of quinolone-resistant isolates with the GyrA mutation. The Pazufloxacin STD Group.

Forty-two men with gonococcal urethritis were treated with an oral dosage of 200 mg of pazufloxacin, a new fluoroquinolone, three times daily for 3 days. Only 28 of the 42 men (66.7%) had negative culture results for Neisseria gonorrhoeae during follow-up. Of the 42 isolates, 41 could be recultured for antibiotic susceptibility testing and DNA sequencing. In 26 of the 41 isolates (63.4%), GyrA mutations with or without ParC mutations were identified. Among the 26 isolates, 23 contained a single GyrA mutation, 1 contained two GyrA mutations, and 2 contained three mutations including double GyrA and single ParC mutations. A single Ser-91-to-Phe mutation, which was detected in 14 of the 26 isolates, was the most common GyrA mutation, followed by an Ala-75 to Ser mutation and an Asp-95 to Asn or Gly mutation in GyrA. All three isolates with two or three mutations contained the Ser-91-to-Phe GyrA mutation. Eleven of the 14 isolates with the single Ser-91-to-Phe mutation within GyrA and all 3 isolates with two or three mutations persisted after pazufloxacin treatment. On the other hand, all 15 wild-type and 9 mutant isolates with a substitution at codon Ala-75 or Asp-95 were eradicated. The mean MIC of pazufloxacin for mutants with the single Ser-91-to-Phe mutation in GyrA was 66-fold higher than that for the wild type. The results obtained in this study suggest that a high prevalence of fluoroquinolone-resistant gonococcal isolates with the Ser-91-to-Phe mutation in GyrA reduced the efficacy of pazufloxacin as treatment for gonococcal urethritis.

Adult↗
PubMed1998

Effect of urine component on leukocyte chemiluminescence response.

In the urine, the function of polymorphonuclear leukocytes (PMNs) is thought to be impaired because of the high osmolality and low pH along with a high concentration of inorganic salts. We investigated the effect of the properties of urine and its components on the chemiluminescence (CL) response of PMNs. This was helped by using an artificial urine. The CL response was measured by automatic luminometer following stimulation of phorbol myristate acetate. We found the CL response of PMNs to be significantly suppressed at a pH of 6 or 5, but not suppressed at a pH of 7 or 8. The CL response was significantly reduced when the osmolality was increased to 580 or 800 mOsm/kg H2O by the addition of urea as compared to the response in the standard artificial urine at an osmolality of 425 mOsm/kg H2O. A change in the osmolality by the addition of mannitol only minimally influenced the CL responses. In addition, the CL response was significantly impaired by both low and high concentrations of sodium at 12 and 300 mEq/L as compared to 77.5 mEq/L in the standard artificial urine. Potassium significantly reduced the CL response in a concentration-dependent manner in the range of from 4 to 31 mEq/L as compared to 52.3 mEq/L in the standard artificial urine. A high concentration of calcium at 8.1 or 9.9 mg/dL reduced CL response as compared to 3.9 mg/dL, whereas CL response was not reduced by the change in the concentration of magnesium. A high concentration of creatinine significantly reduced the CL response as compared to the standard artificial urine. We conclude that the function of PMNs in urine is reduced mainly by urine pH, concentration of urea, sodium, potassium, and creatinine. We suggest that reversal of these change in urine may restore functions of PMNs to clear bacteria in patients with urinary tract infections.

Bacteriuria↗
PubMed1997

Chemiluminescence response of whole blood in patients undergoing urological operations.

Polymorphonuclear leukocytes (PMNs) are one of the most important components of the defence mechanisms against bacterial infection. The functions of PMNs are believed to be impaired in patients during the perioperative period. Bactericidal function of PMNs was investigated together with the luminol-dependent chemiluminescence (CL) reaction of whole blood in 23 patients, 12 undergoing open surgery and 11 undergoing endoscopic surgery. Blood samples were collected one day before surgery (day -1) and 2 hours (day 0), 24 hours (day 1) and 7 days (day 7) after surgery. Counts of whole white blood cells (WBCs), PMNs and lymphocytes were not different between the two surgery groups. CL responses in the open surgery group were increased on days 0, 1 and 7. In the endoscopic surgery group, CL response was increased on day 1, but not on day 0 or day 7. These results suggest that the PMN function during the perioperative period was not impaired, but increased just after surgery, mainly due to an increasing number of WBC caused by the surgical intervention.

Adult↗
PubMed1997

Olfactory evoked potential produced by electrical stimulation of the human olfactory mucosa.

Most physiological studies of the human olfactory system have concentrated on the cortical level; the olfactory bulbar level has been studied rarely. We attempted to stimulate the human olfactory mucosa by electrical pulse to detect the bulbar potentials. Electrical stimulation (2 mA, 0.5 ms) of the human olfactory mucosa evoked a change in potential recorded from the frontal sector of the head. A negative peak of the evoked potential that occurred at 19.4 ms (grand means, n = 5) after stimulation was the clearest. The highest amplitude of the potential was recorded from the frontal sector of the head on the stimulated side. Our findings were similar to the experimental results obtained from the olfactory bulbs of animals. This evoked potential was considered to be the human olfactory bulbar potential. When the subjects were stimulated by applying electricity to the olfactory mucosa, no sensation of smell occurred even though evoked potentials were recorded. Evoked potentials were recorded only when the stimulating electrode was located in the olfactory cleft. When the stimulating electrode was outside the olfactory cleft, the stimulation caused pain. The trigeminal nerve seemed to be stimulated by electricity. Olfactory evoked potentials produced by the electrical stimulation of the human olfactory mucosa should aid the research on human olfactory physiology, and may be applicable to clinical tests of olfactory dysfunction.

Electric Stimulation↗
PubMed1997

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

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.

Adhesins, Escherichia coli↗
PubMed1997

Prevention of catheter-associated urinary tract infection by meatal disinfection.

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.

Anti-Infective Agents, Local↗
PubMed1997

[Spirochetosis].

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Humans↗
PubMed1997

[Rickettsiosis].

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Animals↗
PubMed1996

Olfactory evoked potentials produced by electrical stimulation of the olfactory mucosa.

We stimulated the olfactory mucosa electrically and elicited evoked potentials in rabbits. A bipolar stimulating electrode was placed on the olfactory region of the nasal mucosa via an anterior naris non-invasively. Evoked potentials were detected from the surface of a head. In most instances they were composed of triphasic negative-positive-negative peaks, the latencies of these peaks were about 25, 40, and 65 ms, respectively. This peak complex seemed to originate in the olfactory bulb. This method is non-invasive and is applicable to studying the olfactory system in animals and also in humans.

Animals↗
PubMed1996

Trends in sexually transmitted diseases and condom use patterns among commercial sex workers in Fukuoka City, Japan 1990-93.

OBJECTIVE: To investigate trends in sexually transmitted diseases (STDs) among female commercial sex workers and in their condom use patterns during the period from 1990 to 1993 in Fukuoka, Japan. METHODS: The study group consisted of a total of 824 commercial sex workers who attended an STD clinic to undergo screening for STDs including chlamydia, gonorrhoea, syphilis, hepatitis B and HIV-1 infection during the period from 1990 to 1993. For detection of Chlamydia trachomatis and Neisseria gonorrhoeae, endocervical smear specimens were taken from the women. Blood samples were obtained for serological diagnosis of syphilis, hepatitis B and HIV-1. Commercial sex workers who visited the clinic during the period from November to December of 1993 were interviewed concerning past (1990 and 1991) and recent (1992 and 1993) condom use patterns. RESULTS: The annual detection rates of C trachomatis and N gonorrhoeae declined significantly from 16.3% in 1990 to 12.2% in 1993 (P < 0.0001) and from 1.5% in 1990 to 0.8% in 1993 (P = 0.0096), respectively. There was a remarkable reduction in the annual syphilis infection rate, from 7.5% in 1990 to 0.5% in 1993 (P = 0.0011). The positive rate for the hepatitis B surface antigen in the women ranged from only 0.6% to 1.9% and none were found to be positive for HIV-1 during the 4-year period. During the same period, there was a significant increase in the proportion of commercial sex workers always using condoms from 6.3% in 1990-91 to 25.3% in 1992-93 (P = 0.0023). CONCLUSION: The prevalences of chlamydia, gonorrhoea, and syphilis infections decreased significantly among commercial sex workers in Fukuoka from 1990 through 1993, and no commercial sex workers were HIV-1 seropositive. The reductions in the prevalence of major STDs may be related to the increased use of condoms.

Adolescent↗
PubMed1996

Inhibition of chemiluminescence response of human polymorphonuclear leukocytes by three different stimulations in hyperosmotic condition comparable to the renal medulla.

Hyperosmolality in renal medulla inhibits functions of polymorphonuclear leukocyte (PMN) such as phagocytosis, intracellular killing, and superoxide generation. The main factors of hyperosmolality in the renal medulla are thought to be urea and NaCl. We studied the luminol-dependent chemiluminescence (CL) response of PMNs to three different stimulators: phorbol myristate acetate (PMA), formyl-methionyl-leucyl-phenylalanine (FMLP), and opsonized zymosan (OZ). When PMNs were incubated or preincubated with hyperosmotic urea or NaCl solutions, CL responses were significantly reduced following stimulation by each of PMA, FMLP, or OZ. Reduction of CL response was concentration and osmolality dependent in hyperosmotic urea and NaCl solution. These results suggest that respiratory burst and production of active oxygen species of PMNs through three different signal transduction pathways are inhibited in hyperosomotic conditions comparable to the renal medulla.

Cells, Cultured↗
PubMed1995

Preventive effect of ulinastatin on renal scarring in rat model of pyelonephritis induced by direct or ascending infection with Serratia marcescens or Escherichia coli.

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.

Animals↗
PubMed1995

Effect of pili of Serratia marcescens on superoxide production and phagocytosis of human polymorphonuclear leukocytes.

PURPOSE: To determine the role played by superoxide in renal scar formation following renal infection. MATERIALS AND METHODS: The piliation of bacteria was assessed for its capacity to interact with human polymorphonuclear leukocytes (PMNs). Two recombinant strains having either MS or MR pili of Serratia marcescens were constructed. RESULTS: The MS-piliated strain stimulated superoxide production of PMNs twice as much as the MR- or nonpiliated strains did. The MS-piliated strain was more susceptible to phagocytosis than was the MR- or nonpiliated strain. CONCLUSION: These data suggest that the MS-piliated strain stimulates superoxide production of PMNs associated with phagocytosis, which leads to tissue damage in infected organs.

Drug Resistance, Microbial↗
PubMed1995

Testicular injury induces cell-mediated autoimmune response to testis.

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.

Animals↗
PubMed1994

Modified combination chemotherapy of cisplatin and 5-fluorouracil in squamous cell carcinomas of the head and neck.

Randomized studies on the efficacy of two courses of different types of chemotherapy, including cisplatin and 5-fluorouracil (5-FU), were performed on 130 previously untreated cases with advanced squamous cell carcinomas of the head and neck. Cisplatin, followed by 120-hr continuous 5-FU infusion given in the conventional way, was administered to 60 patients (Group A), while cisplatin was administered 72 hr after the initiation of continuous 5-FU infusion in 70 other patients (Group B). The overall response rates (complete response plus partial response) were 58% in group A and 69% in group B, respectively. A superior complete response rate was obtained in cases receiving modified chemotherapy (10% in group A vs 20% in group B). There was no significant difference in the incidence of side effects between the two groups. These findings indicate that the modified cisplatin plus 5-FU combination chemotherapy tested here is more efficacious regimen than that of the conventional one to achieve high complete response rate and subsequently, to improve the survival of advanced carcinoma cases of the head and neck.

Adult↗