[A study on contamination from Legionella spp. at a home for the elderly in Toyohashi City].

OBJECTIVE: Legionnaires disease has been attributed to Legionella spp. in the water distribution systems of buildings. However, recently cases due to contamination of thermal-bath water have been reported in Japan. In this investigation, we examined the supervision of baths and the presence of Legionella spp. in thermal-bath water of homes for the elderly in Toyohashi city. METHODS: The research was conducted through questionnaires on bathing facilities at 50 sites. Thermal baths were found to be installed at 14 of the sites. We then tested 22 samples from the 14 sites for Legionella spp. and other materials. RESULTS: From the genus Legionella, only Legionella pneumophila was detected, in 8 samples from 4 sites. Coliforms were also detected. Moreover, disinfectant was not detected in any of the Legionella positive samples of bath water. Legionella positive sites had, however, been replacing their water once a day. CONCLUSIONS: These findings indicate that the use of disinfectant and the proper supervision of bathing facilities are important in controlling Legionella spp. Legionnaires disease can be averted in homes for the elderly through appropriate measures.

Disseminated retinoblastoma successfully treated with myeloablative chemotherapy--implication for molecular detection of minimal residual disease.

A useful marker for detecting minimal residual disease (MRD) has not been established yet in retinoblastoma. We assessed neuroendocrine protein gene product 9.5 (PGP9.5) expression, one of the markers for detecting MRD in neuroblastoma, in a patient with disseminated retinoblastoma. A 3-year-old boy with disseminated retinoblastoma in multiple bones and marrow was referred to our hospital. He received intensive treatment and has maintained CR for 48 months following myeloablative chemotherapy with hematopoietic stem cell transplantation (SCT). PGP9.5 expression was serially assessed by RT-PCR in peripheral blood mononuclear cells (PBMC), bone marrow cells (BMC) and mobilized peripheral blood stem cells (PBSC). Initially, his BMC consisted of 96% tumor cells which were proved to express PGP9.5 by RT-PCR. Moreover, PBMC were found to be positive for PGP9.5 indicating the presence of tumor cells in the peripheral blood. After intensive chemotherapy, PGP9.5 expression became negative in both PBMC and BMC. Prior to SCT, PBSC and BMC transplants were confirmed negative for PGP9.5 expression. It is suggested that PGP9.5 expression is a useful marker for evaluating therapeutic effects as well as detecting MRD in retinoblastoma.

[A case of primary malignant lymphoma of the bladder].

The patient was a 34-year-old male. He visited a community hospital complaining of macroscopic hematuria and pollakiuria. Cystoscopic examination demonstrated a bladder tumor. Transurethral resection of the bladder tumor (TUR-Bt) was performed. Histological examination disclosed malignant lymphoma (non-Hodgkin's lymphoma, mixed type). The tumor was classified into the B cell type by the immunohistological staining with surface antigens. He was referred to St. Marianna University, School of Medicine for chemotherapy. Pelvic computed tomography (CT) after admission demonstrated a tumor with a wide pedicle located in the vesicle triangle extending to the posterolateral wall of the bladder. No abnormalities were found in other organs. After establishment of the diagnosis of primary bladder malignant lymphoma, 6 courses of chemotherapy (adriamycin, vincristine, cyclophosphamide, prednisolone, etoposide, methotrexate) were performed. The tumor disappeared completely on imaging studies after chemotherapy. Biopsy of the bladder disclosed no abnormal tissues. No evidence of recurrence or metastasis was found 5 years after chemotherapy.

The mechanism of sensitizing effect of a triazine dye, cibacron blue F3GA, on methicillin-resistant Staphylococcus aureus to oxacillin.

We recently found that a triazinyl dye, cibacron blue F3GA (CB), has a sensitizing effect on the in-vitro susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) to oxacillin (C. Shirai, M. Sugai, H. Komatsuzawa, K. Ohta, M. Yamakido, H. Suginaka, Antimicrob. Agents Chemother. 42: 1278-1280, 1998). Among nine triazinyl dyes tested, CB the strongest sensitizing effect. Population analysis demonstrated that CB reduced the resistance level of MRSA. In the presence of oxacillin at subinhibitory concentrations, CB inhibited the growth of MRSA, but its effect on the cells appeared to be bacteriostatic. Under experimental conditions, CB did not affect the amount of PBP2', binding of [14C]benzylpenicillin to PBP2', or peptidoglycan susceptibilities to bacteriolytic enzymes. Autolytic enzyme-deficient MRSA mutants were equally as sensitive as the parent strain to the effect of CB on the susceptibility to oxacillin. CB affected the resistance level of MRSA irrespective of the status of the mecI/mecR1 element and/or penicillinase plasmids. The sensitivities of several bacteriolytic enzymes to heat-inactivated MRSA cells were not affected when the cells grown in the presence of CB. CB did not stimulate the release of lipoteichoic acid from the cells. These results suggest that the sensitization effect of CB cannot be simply explained by its effect on mecA related products, autolysins, femAB products or the release of lipoteichoic acid.

A triazine dye, cibacron blue F3GA, decreases oxacillin resistance levels in methicillin-resistant Staphylococcus aureus.

Cibacron blue F3GA (CB) was found to reduce the MIC of oxacillin for methicillin-resistant Staphylococcus aureus (MRSA). This effect was not observed with methicillin-susceptible S. aureus. CB alters the resistance level of MRSA through a factor(s) other than mecA-related products, major autolysins, or femAB products. The exact target(s) of CB in causing the effect is unknown.

Triton X-100 alters the resistance level of methicillin-resistant Staphylococcus aureus to oxacillin.

We used population analysis to examine the effects of Triton X-100 on the level of resistance to oxacillin of 18 methicillin-resistant Staphylococcus aureus. In the presence of 0.02% Triton-X-100, 17 formerly methicillin-resistant strains exhibited enhanced sensitivity to oxacillin. One homogenous isolate, KSAF1 was barely affected by the Triton X-100. Sensitivities of lysostaphin, 51 kDa N-acetylglucosaminidase and 62 kDa N-acetylmuramoyl-L- alanine amidase to heat-inactivated cells were not affected when the bacteria were grown in 0.02% Triton X-100. Our data, together with those of a previous study, suggested that Triton X-100 alters the resistance level of methicillin-resistant S. aureus influencing a factor (s) other than PBPs, bacteriolytic enzymes, or femAB products.

[Neuroblastoma].

Neuroblastoma is the most common and highly malignant tumor. The 2-year survival rate for NB patients for 1970s was 32% in US and 29% in Japan. But, improvement of prognosis was observed by recent advances in surgery, chemotherapy and numerous other supportive therapies. We introduce the some treatment regimens to patients with neuroblastoma which should be selected by the age and the stage at diagnosis and other prognostic factors such as N-myc amplification, trk overexpression, chromosome anomalies (lp-. double minutes, homogeneous staining region) of neuroblastoma cells and histological pathology. As a general rules, patients under 1 year of age without unfavorable prognostic factors should be treated less intensive regimen, even their tumors are progressive stages. Conversely, patients with progressive stages over 1 year of age without unfavorable factors, it is necessary to treat with intensive protocol. Furthermore, to patients of all age group with unfavorable factors, they are given a very strong intensive treatment through advances in supportive therapies such as the new antiemetics, G-CSF, antibiotics, or IVH etc.. Recent treatment regimens to the patients with neuroblastoma are presented.