Five-year trends in bacterial contamination of dialysis equipment.

Bedside dialysis monitoring equipment for hemodialysis are located in the bioburden section upstream of the endotoxin-retentive filter for dialysis fluid sterilization. We observed 26 equipment at our institution for bacterial contamination at least once every 4 weeks for 5 years with another ultrafiltration membrane upstream to prevent bacterial contamination. Bacterial contamination levels were highest and most diverse at the time of the first flush. During subsequent initial cleanng, the contamination level decreased, and bacterial species converged almost exclusively to one genus, namely Methylobacterium spp. During clinical use, the equipment were cleaned and disinfected daily after dialysis, and daily operations and maintenance were performed using aseptic techniques. Although the frequency of bacterial detection decreased annually, the same bacterial genotypes observed at the first flush were isolated even after long time periods and were thought to persist in the equipment possibly by forming biofilm. Pseudomonas aeruginosa was newly detected after the replacement of parts during breakdown maintenance, indicating the need to sterilize replacement parts. Thus, the bioburden should be assessed regularly as part of the management of in-house-produced dialysis fluid.

Sodium Hypochlorite is Effective against Biofilms in Dialysis Equipment.

To test the efficacy of chemical disinfectants against bacterial biofilms in hemodialysis equipment, a Center for Disease Control and Prevention (CDC)-Biofilm Reactor was used to create biofilms. Methylobacterium radiotolerance was isolated from the hemodialysis fluid and used as the test organism. We examined the efficacy of sodium hypochlorite (NaOCl) in elimination of planktonic cells compared to that in the case of biofilms. Planktonic bacteria were completely eliminated at 50 parts per million (ppm) of NaOCl, which is the lowest concentration for clinical use. The viable cell count in the biofilm reached its minimum value around a logarithmic reduction value (LRV) of 6, when the concentration was raised to 1000 ppm and the reaction time was extended by 1 hour or more. Furthermore, at 200 ppm, the LRV was elevated depending on the time. And the LRV while maintaining static conditions for 6 hours at 200 ppm was similar to that of short time at 1000 ppm. These results suggest that NaOCl has sufficient bactericidal activity even for biofilms at a practical concentration and reaction time, and that the CDC-Biofilm Reactor is an effective tool for finding useful disinfection conditions.

Detection Method for Aquatic Bacteria of the Fingers, as a Potential Origin of the Aqueous Solution Contamination.

　Aquatic bacteria were isolated from the hands of working staffs by an adapted culture protocol. When the sample solution obtained by the" glove juice method" was incubated for 3 days at room temperature, viable cell counts increased up to 105-fold, and the majority of the isolated colonies were shown to be Gram-negative aquatic bacteria, which carry the risk of contaminating water. Using R2A medium, coagulase-negative staphylococci were the dominant microbes immediately after recovery from the hands. Here it was revealed that bacteria of the phylum Proteobacteria isolated from the hand can be the causative bacteria of aqueous contamination. This modification in the GJ method may be useful as an effective training protocol to demonstrate the importance of hand hygiene and clean operation for aseptic manufacturing.

Rapid detection of microbes in the dialysis solution by the microcolony fluorescence staining method (Millflex quantum).

A chemiluminescence system, Milliflex Quantum (MFQ), to detect microcolonies, has been used in the pharmaceutical field. In this study, we investigated aquatic bacteria in hemodialysis solutions sampled from bioburden areas in 4 dialysis faculties. Using MFQ, microcolonies could be detected after a short incubation period. The colony count detected with MFQ after a 48-hour incubation was 92% ± 39%, compared to that after the conventionally used 7-14-day incubation period; in addition, the results also showed a linear correlation. Moreover, MFQ-based analysis allowed the visualization of damaged cells and of the high density due to the excessive amount of bacteria. These results suggested that MFQ had adequate sensitivity to detect microbacteria in dialysis solutions, and it was useful for validating the conditions of conventional culture methods.

Benign multicystic peritoneal mesothelioma mimicking recurrence of an ovarian borderline tumor: a case report.

INTRODUCTION: Benign multicystic peritoneal mesothelioma is an extremely rare tumor that occurs mainly in women in their reproductive age. Its preoperative diagnosis and adequate treatment are quite difficult to attain. CASE PRESENTATION: Our patient was a 23-year-old Japanese woman who had a history of right oophorectomy and left ovarian cystectomy for an ovarian tumor at 20 years of age. The left ovarian tumor had been diagnosed on histology as a mucinous borderline tumor. Two years and nine months after the initial operation, multiple cysts were found in our patient. A laparotomy was performed and her uterus, left ovary, omentum and pelvic lymph nodes were removed due to suspicion of recurrence of the borderline tumor. A histological examination, however, revealed that the cysts were not a recurrence of the borderline tumor but rather benign multicystic peritoneal mesothelioma. There were no residual lesions and our patient was followed up with ultrasonography. She remains free from recurrence nine months after treatment. CONCLUSION: We report a case of benign multicystic peritoneal mesothelioma mimicking recurrence of an ovarian borderline tumor. Benign multicystic peritoneal mesothelioma should be suspected when a multicystic lesion is present in the pelvis as in the case presented here, especially in patients with previous abdominal surgery.

Precise evaluation of chemotherapy-induced peripheral neuropathy using the visual analogue scale: a quantitative and comparative analysis of neuropathy occurring with paclitaxel-carboplatin and docetaxel-carboplatin therapy.

BACKGROUND: Some regimens of chemotherapy cause peripheral neuropathy such as pain in muscles and joints and numbness in the limbs. It is often difficult to estimate the neuropathy accurately and analyze it in detail. The aim of this study was to investigate whether chemotherapy-induced peripheral neuropathy could be appropriately estimated by using the visual analogue scale (VAS). METHODS: Ninety-three patients who received paclitaxel and carboplatin treatment (TC) or paclitaxel and docetaxel treatment (DC) participated in answering a questionnaire about peripheral neuropathy using the VAS. As a result, 134 cycles of TC and 79 cycles of DC were evaluated. The average of VAS scores at every 10 days after each cycle of chemotherapy began was calculated. The daily change in VAS scores was also analyzed, and average VAS scores compared between TC and DC. RESULTS: Daily changes in peripheral neuropathy for each treatment could be demonstrated in detail. Pain and numbness had separate patterns of appearance. For both pain and numbness, a greater VAS score was observed in patients receiving TC than in those receiving DC. As the number of cycles grew, peripheral neuropathy became more serious in TC. CONCLUSIONS: The VAS could appropriately recognize the difference in peripheral neuropathy between TC and DC. Moreover, the VAS could also catch the change in peripheral neuropathy. This result suggests that the VAS system is a useful tool for managing peripheral neuropathy.