Tetsuro Matsumoto

Dosage effect on uropathogenic Escherichia coli anti-adhesion activity in urine following consumption of cranberry powder standardized for proanthocyanidin content: a multicentric randomized double blind study

BackgroundIngestion of cranberry (Vaccinium macrocarpon Ait.) has traditionally been utilized for prevention of urinary tract infections. The proanthocyanidins (PACs) in cranberry, in particular the A-type linkages have been implicated as important inhibitors of primarily P-fimbriated E. coli adhesion to uroepithelial cells. Additional experiments were required to investigate the persistence in urine samples over a broader time period, to determine the most effective dose per day and to determine if the urinary anti-adhesion effect following cranberry is detected within volunteers of different origins.MethodsTwo separate bioassays (a mannose-resistant hemagglutination assay and an original new human T24 epithelial cell-line assay) have assessed the ex-vivo urinary bacterial anti-adhesion activity on urines samples collected from 32 volunteers from Japan, Hungary, Spain and France in a randomized, double-blind versus placebo study. An in vivo Caenorhabditis elegans model was used to evaluate the influence of cranberry regimen on the virulence of E. coli strain.ResultsThe results indicated a significant bacterial anti-adhesion activity in urine samples collected from volunteers that consumed cranberry powder compared to placebo (p < 0.001). This inhibition was clearly dose-dependent, prolonged (until 24 h with 72 mg of PAC) and increasing with the amount of PAC equivalents consumed in each cranberry powder regimen. An in vivo Caenorhabditis elegans model showed that cranberry acted against bacterial virulence: E. coli strain presented a reduced ability to kill worms after a growth in urines samples of patients who took cranberry capsules. This effect is particularly important with the regimen of 72 mg of PAC.ConclusionsAdministration of PAC-standardized cranberry powder at dosages containing 72 mg of PAC per day may offer some protection against bacterial adhesion and virulence in the urinary tract. This effect may offer a nyctohemeral protection.

Suppression of renal scarring by prednisolone combined with ciprofloxacin in ascending pyelonephritis in rats

To prevent renal scarring, which occurs at the end stage of chronic pyelonephritis due to vesicoureteral reflux of infected urine, immediate antimicrobial treatment is reported to be essential. When treatment is delayed, the antimicrobial agent is believed to be effective only in eliminating bacteria, not in preventing scar formation. Using the ascending pyelonephritis model in rats, we investigated the effect of immediate or delayed treatment with ciprofloxacin and that of delayed treatment with a combination of ciprofloxacin and prednisolone in preventing renal scarring following infection. An inoculum of 1 x 10(9) colony forming units (cfu)/0.1 ml. of the HM32 strain of Escherichia coli, which was isolated from a patient with a urinary tract infection, was injected directly into the rat bladder, and the urethra was clamped for 4 hours in each rat. Treatment by ciprofloxacin (15 mg./kg., twice a day for 5 days) alone or in combination with prednisolone (2 mg./kg., once a day for 4 days) was initiated 6 or 72 hours after bacterial inoculation. The kidneys of each rat were examined 6 weeks later. Immediate treatment by ciprofloxacin significantly inhibited renal scarring (no scarring was seen in any of the 8 rats), but delayed treatment had no effect on scarring (4 of 8 rats showed scarring) when compared with the untreated controls (7 of 8 rats showed scarring). However, the addition of prednisolone to the delayed treatment with ciprofloxacin significantly inhibited renal scarring (only 1 of 10 rats showed scarring) when compared with the untreated controls (7 of 8 rats showed scarring). These data suggest that prednisolone is effective in preventing renal scarring which occurs due to vesicoureteral reflux when the initiation of antimicrobial treatment is delayed.

Elevated Interleukin-8 Levels in the Urine of Children with Renal Scarring and/or Vesicoureteral Reflux

PURPOSE Elevation of urinary levels of interleukin-6 and 8 has been observed in patients with acute urinary tract infections. However, to our knowledge there have been no studies concerning the secretion of interleukin-6 and 8 into the urine after acute inflammation has resolved and renal scarring has occurred. On the other hand, it is well known that cytokines are variously related to glomerular diseases and, thus, it is possible that the progression of reflux nephropathy depends on interleukin-6 or 8. Therefore, we assessed urinary levels of interleukin-6 and 8 in children with vesicoureteral reflux and/or renal scarring. MATERIALS AND METHODS We evaluated interleukin-6 and interleukin-8 levels in the urine of 32 children without a urinary tract infection who presented or were admitted to our hospital because of vesicoureteral reflux between April and December 1994. Interleukin-6 and 8 were determined using a commercially available human enzyme-linked immunosorbent assay kit and the 2-step sandwich method. RESULTS Urinary interleukin-6 levels were below the lower detection limit (less than 10 pg./ml.) in all samples. There were statistically significant differences between urinary interleukin-8 levels in children with and without renal scarring (p = 0.001), and with and without vesicoureteral reflux (p = 0.0246). CONCLUSIONS Urinary interleukin-8 is an effective marker for renal scarring and vesicoureteral reflux.

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.

Suitability of Colchicine and Superoxide Dismutase for the Suppression of Renal Scarring following an Infection with Bacteria Showing Mannose-Sensitive Pili

Two new strains of Serratia marcescens were constructed by the gene manipulation method from the clinical isolate US 46, which has two kinds of pili--mannose-sensitive (MS) and mannose-resistant (MR) ones--on the cell surface. After cloning the genes of the MS and MR pili, either the MS or the MR gene was transferred to the nonpiliated Escherichia coli, and MS- or MR-piliated strains were obtained. In the experimental pyelonephritis model of rats, MS- or MR-piliated bacteria were inoculated directly to the renal parenchyma, and the following results were obtained. MS-piliated rather than MR-piliated strains stimulated severe scarring of the kidney, and this scarring was suppressed by treatment with colchicine or superoxide dismutase (SOD) during an early stage of the infection. These findings suggest that MS-piliated bacteria stimulated polymorphonuclear leukocytes, which released large amounts of superoxide resulting in renal scarring. SOD was hoped to be a drug capable of preventing renal scarring, and such a result was successfully obtained.

Antioxidant Effect on Renal Scarring following Infection of Mannose-Sensitive-Piliated Bacteria

Renal scars have been considered to occur in later stages of chronic pyelonephritis. In our experimental pyelonephritis model, bacteria which possessed mannose-sensitive (MS) pili on the surface promoted renal scarring following inoculation to the renal parenchyma. Polyethylene glycol-modified superoxide dismutase (PEG-SOD) and 2-O-octadecylascorbic acid (CV3611) significantly suppressed scarring when administered orally or parenterally during the early stage of kidney infection with MS-piliated bacteria. These findings suggest that the superoxide and other active oxygens play an important role in renal scarring following infection and that PEG-SOD and CV3611 may be agents capable of preventing renal scarring following bacterial pyelonephritis.

CELL-MEDIATED AUTOIMMUNE RESPONSE TO TESTIS INDUCED BY BILATERAL TESTICULAR INJURY CAN BE SUPPRESSED BY CYCLOSPORIN A

PURPOSE Since the delayed type hypersensitivity (DTH) response to testis antigens 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 have investigated the immunosuppressive effect of cyclosporin A (CsA) on the DTH response to autologous testicular cells (TC). MATERIALS AND METHODS A DTH response to autologous TC was induced in C3H/HeN mice by bilateral testicular injury (trauma). CsA was administered intraperitoneally for 10 consecutive days before and after injury. A DTH response was assessed by measuring delayed footpad reaction (DFR) to autologous TC 9 days after injury. RESULTS When the mice were traumatized alone, 10 mg./kg. or more of CsA suppressed the DTH response to autologous TC significantly. In mice traumatized with 100 mg./kg. of cyclophosphamide (CY)-pretreatment, 30 mg./kg. or more of CsA was needed to suppress the DTH response. In mice traumatized with 200 mg./kg. of CY-pretreatment, 50 mg./kg. of CsA was needed to suppress the autoimmune response. CONCLUSIONS The DTH response to autologous TC was suppressed significantly by administration of CsA in a dose-dependent manner. We have also shown the direct suppressive effect of CsA on effector cells for DTH by means of local passive transfer of DTH. Administration of CsA had no augmenting or suppressive effect on suppressor cells for DTH. CsA might be a significant drug for the immunosuppression of EAO and possibly for immunological male infertility.

Role of superoxide in renal scarring following infection by mannose-sensitive piliated bacteria

SummaryThe role of superoxide in scar formation following renal infection caused by mannose-sensitive (MS) piliated strains of bacteria was studied in the experimental pyelonephritis model using female Sprague-Dawley rats. The MS piliated strain stimulated renal scarring to a significantly greater extent than either the non-piliated or MR-piliated strain. Modulation of leukocytes by administering cyclophosphamide to induce neutropenia and colchicine to inhibit leukocyte migration was effective in preventing renal scarring. Treatment with superoxide dismutase during the early stage of infection was also effective in preventing scar formation. Finally, the production of superoxide by rat leukocytes was significantly larger following stimulation by MS piliated than either the nonpiliated or MR piliated strains. These observations suggest that superoxide released from leukocytes plays a critical role in the development of renal scarring following a bacterial infection, especially by MS piliated strains.

Enhanced chemiluminescence response of polymorphonuclear leukocytes by new quinolone antimicrobials.

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.

Increased renal scarring by bacteria with mannose-sensitive pili

SummaryRenal scars are thought to be the end stage of chronic pyelonephritis and one of the most important causes of renal insufficiency and renal hypertension. The role of bacterial pili was examined in scar formation after an infection of newly constructed bacterial strains using the recombinant DNA technique, which possessed either mannose resistant (MR) or mannose sensitive (MS) pili of Serratia marcescens. Strains that differed in only a single virulence factor, namely, MR or MS pili, were used in a rat model of chronic pyelonephritis. In this model, MS-piliated bacteria stimulated renal scarring more severely than non-piliated or MR-piliated bacteria.