Evaluation of Legiolert for Quantification of Legionella pneumophila from Bath Water Samples.

Testing for Legionella spp. in public bath water samples is regulated in Japan. In this study, we used a total of 132 public bath water samples to compare the performance of Legiolert® and the conventional plate culture method for the enumeration of Legionella pneumophila. When Legiolert and plate culturing were performed at the same detection limit, L. pneumophila was detected in 26.5% of 132 samples by Legiolert, while 12.9% contained Legionella spp. (11.4% contained L. pneumophila) based on the plate culture method. Moreover, results of 83.3% of the total samples were consistent between the two methods, meaning that they were both positive or both negative. In this study, we demonstrated that Legiolert is a simpler and more effective method of monitoring for L. pneumophila in bath water samples.

Purging in autologous hematopoietic stem cell transplantation using adenosine triphosphate (ATP) and 4-hydroperoxycyclophosphamide (4-HC).

In this study, we show potent in vitro purging induced by adenosine triphosphate (ATP) for leukemic cells. The treatment of murine L1210 leukemic cells with 2mM of ATP in vitro for 3h was able to reduce the number of leukemic clonogenic cells by about one order of magnitude presumably by changing the permeability of the leukemic cell membrane. Furthermore, the incubation of L1210 cells with ATP (2mM) and low dose 4-hydroperoxycyclophosphamide (4-HC, 2 microg/ml) for 3h resulted in at least a four-log reduction of clonogenic L1210 cells. Only a slight degree of toxicity to pluripotent hematopoietic stem cells (CFU-S) was observed in both treatment protocols. To determine the efficacy of pharmacological purging by ATP, we designed a murine system to mimic the conditions expected in the clinical setting of autologous transplantation using simulated partial remission marrow (SPRM) which was prepared by mixing normal marrow cells and L1210 cells at a ratio of 9:1. After the SPRM cells were incubated in vitro at a concentration of 1 x 10(6)/ml with both ATP (2mM) and low dose 4-HC (2 microg/ml) for 3h, 5 x 10(4) of the cells were then injected into lethally irradiated 9 weeks male BDF1 mice. All the mice given untreated-SPRM died of leukemia by day 27, whereas none of the recipients transplanted treated-grafts had died by day 70, thus suggesting that the combination use of ATP and 4-HC may be a potentially effective way to purge leukemic cells in autologous stem cell transplantation. The mechanism of the selective killing of leukemic cells is assumed that 4-HC is effectively incorporated into leukemic cells by increasing the permeability of the cell membrane by ATP. Taken together, this simple and rapid procedure is able to purge leukemic cells from autologous bone marrow grafts.

[Airway hyperreactivity in patients undergoing hematopoietic stem cell transplantation].

Airway hyperreactivity (AHR) was studied with an astograph for 34 sequential hematopoietic stem cell transplantation (HSCT) patients before and after HSCT. The percentage of Dmin positive patients was 25.0% before HSCT and 25.0-57.1% after HSCT, while all normal subjects were negative for Dmin. The mean Dmin of post HSCT patients was 22.7 u in days 501-1000 and 19.3 u after 1001 days, which was significantly lower than the 45.2 u of normal controls. The patients were divided into two groups according to the treatment before HSCT, strongly treated (S, acute leukemia and non-Hodgikin lymphoma) and weakly treated (W, chronic myelogenous leukemia and aplastic anemia) patients. The ratio of Dmin positive patients and mean Dmin in the W group after HSCT (38.9%, 27.8 u), and the S group before and after HSCT (55.6%, 20.5 u and 45.5%, 23.8 u, respectively), were significantly impaired compared with the findings in the normal controls (0%, 45.2 u). The mean sGrs/Grs count was higher in the W group before HSCT than in the other groups (W before and after HSCT, 0.58 and 0.19, respectively; S before and after HSCT, 0.21 and 0.22, respectively). Taken together, AHR was observed in HSCT patients, particularly for patients in the S group. These data indicate that high dose chemo-radiotherapy including conditioning regimen causes AHR. The mechanisms leading to AHR may be infection, inflammation, and remodeling of the airway.