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Biomedical subjects

M Sakumoto

Publications and source records attributed to M Sakumoto.

42 records · Page 3Linked to original sources

Effect of ebselen on renal scarring in rats following renal infection.

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.

Animals↗

Fleroxacin enhancement of superoxide production by polymorphonuclear leukocytes: the role of protein kinases.

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.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

Distribution of a methicillin-resistance gene in urinary isolates of methicillin-resistant staphylococci examined by enzymatic detection of the polymerase chain reaction.

We tried to examine the susceptibility to various antimicrobial agents and to detect the mec A gene using enzymatic detection of the polymerase chain reaction in methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA) and Staphylococcus epidermidis isolated from patients with complicated urinary tract infections (UTIs). All the strains of MRSA and MSSA showed a low sensitivity to imipenem (IPM), ceftazidime (CAZ), flomoxef (FMOX), amikacin (AMK), ciprofloxacin (CPFX) and ofloxacin (OFLX). Although all the strains of MRSA had the mec A gene, none of the MSSA strains had it. 74% of S. epidermidis had the mec A gene and strains resistant to methicillin were seen in 72% of them. The mec A-positive S. epidermidis showed a lower susceptibility to IPM, CAZ, FMOX, AMK, CPFX and OFLX than the mec A-negative strains. These results suggest that methicillin resistance was due to the mec A gene in MRSA and methicillin-resistant S. epidermidis (MRSE), and that MRSEs were very common among the bacteria causing complicated UTI. When we try to control nosocomial infections due to MRSA, it should also be noted that MRSE can be a reservoir of the mec A gene.

Genes, Bacterial↗

Subdural hematoma associated with dural metastasis from paranasal sinus cancer: a case report and review of the literature.

We report a 72-year-old woman who developed a subdural hematoma following dural metastasis from paranasal sinus carcinoma. Subdural hematoma with malignant neoplasm is a serious condition seen only in advanced stages. The prognosis is poor, but appropriate measures can help the patient. Head and neck surgeons should note this unusual clinical entity.

Aged↗

Secretion of a fibronectin-like substance from head and neck carcinomas.

The secretion of a fibronectin-like substance in culture supernatants of cell lines of head and neck squamous cell carcinomas was observed. Culture supernatants of some tumor cells had a high cell-attachment activity. Enzyme-linked immunosorbent assay with an antifibronectin antibody showed that the supernatant with cell attachment activity contained fibronectin. Furthermore, the cell attachment activity was clearly inhibited by the addition of a monoclonal antibody to fibronectin. These findings strongly suggest that the fibronectin produced by cancer cells is one of the potent mediators of the cell attachment.

Carcinoma, Squamous Cell↗

Combination chemotherapy for infections due to methicillin-resistant Staphylococcus aureus with combination therapy by cefuzonam and fosfomycin or minocycline in the urologic field.

To determine the bacterial and clinical effects of methicillin-resistant Staphylococcus aureus (MRSA) on urinary tract infection (UTI), postoperative wound infection, and bacteremia, 22 strains of MRSA from infected patients were examined; minimal inhibitory concentration (MIC), fractional inhibitory concentration (FIC) index, coagulase typing, and change in MIC in the combination of cefuzonam (CZON) and fosfomycin (FOM) or minocycline (MINO), and the clinical effects of the combination therapy of CZON+FOM or CZON+MINO were investigated in 23 patients. MIC distribution was assessed for 11 drugs: methicillin (DMPPC), cefazolin (CEZ), cefotiam (CTM), cefuzonam (CZON), minocycline (MINO), vancomycin (VCM), arbekacin (ABK), imipenem (IPM), fosfomycin (FOM), ofloxacin (OFLX), and clarithromycin (CAM). For VCM and ABK, MICs ranged from 0.2 to 12.5 micrograms/ml. MINO showed a wide range of MIC, from 0.05 to 25 micrograms/ml. All strains were less sensitive to other antimicrobials. This MIC distribution was assessed in categories by coagulase typing. For CAM, type II strains revealed > or = 100 micrograms/ml of MIC50 and MIC90 compared with 0.2 and 3.13 micrograms/ml in type VII strains. For mixed combinations of CZON and MINO at ratios of 10 to 1 and 40 to 1, the rates of blood concentration for drugs 10 and 120 min after the intravenous injection, MIC distribution was observed between MINO and CZON. For mixed combinations of CZON and FOM at ratios of 1 to 1 and 1 to 4, MIC distribution was more sensitive than for FOM or CZON alone. With respect to the clinical effects of combination therapy by CZON+MINO and CZON+FOM, of seven cases of UTI with CZON+MINO, MRSA was eliminated completely in 4 patients (57.1%). In all patients who received CZON+FOM, MRSA was completely eliminated by this treatment regimen. In 4 of 7 (57.1%) patients with would infection and bacteremia, MRSA was eliminated by the combination of CZON+FOM or CZON+MINO. These results suggest that CZON+FOM is an effective combination in treating UTI and other MRSA infections in urology.

Adult↗