The usefulness of semi‐solid medium in the isolation of highly virulent Leptospira strains from wild rats in an urban area of Fukuoka,Japan

Leptospirosis is a worldwide zoonosis. The importance of urban leptospirosis is recognized in Japan: urban rats carry pathogenic leptospires and people acquire these pathogens through contact with surface water or soil contaminated by the urine of the infected animals. To determine the current Leptospira carriage rate in urban rats, 29 wild rats were trapped in the central area of Fukuoka and strains isolated from their kidneys and urine analyzed. When semi‐solid Korthof's medium containing 0.1% agar was used for isolation, 72.2% and 30.8% of the kidney and urine cultures, respectively, were found to be Leptospira‐positive. The isolates belonged to Leptospira interrogans, and were classified into two groups (serogroups Pomona and Icterohaemorrhagiae) based on the results of gyrB sequence analysis and microscopic agglutination testing (MAT). Strains belonging to serogroup Icterohemorrhagiae grew well in liquid medium. On the other hand, serogroup Pomona isolates multiplied very little in liquid medium, but did grow in a semi‐solid medium. Although strains belonging to serogroup Pomona have not been recognized as native to Japan, this strain may be widely distributed in urban rats. Representative strains from each group were found to be highly pathogenic to hamsters. Our findings should serve as a warning that it is still possible to become infected with leptospires from wild rats living in inner cities of Japan. Furthermore, the use of semi‐solid medium for culture will improve the isolation rate of leptospires from the kidneys of wild rats.     

Influences of weight loss on monocytes and T-cell subpopulations in male judo athletes

The purpose of this study was to examine weight loss effects on immune function in judo athletes. Six elite male Japanese judo athletes (20.3 ± 0.4 years) were enrolled in this study. They completed usual weight loss programs during 2 weeks preceding an actual competition. Subjects noted the appearance of upper-respiratory tract infection (URTI) symptoms during the study period. Blood samples were obtained at 40 (baseline period: BL) and 3 (weight loss period: WL) days before and 1 day after the competition (AC). The CD3, CD4, CD8, CD56CD3, CD28CD4, CD28CD8, and Toll-like-receptor-4 (TLR-4) CD14 cells were counted by using flow cytometer analysis. The 6 subjects reported 1 headache, 3 runny nose conditions, and 1 coughing instance during the WL. The CD3, CD4, CD8, and CD28CD4 cell counts were significantly lower at WL than at BL (p ≤ 0.05); they reverted to the baseline value at AC. The TLR-4CD14 cells were significantly fewer at WL (p ≤ 0.05); they remained fewer than they had been at BL, even at AC. These results suggest that 2 weeks of weight loss before a competition can impair cell-mediated immune function and induce high susceptibility to URTI in judo athletes. Coaches, support staff, and athletes should monitor athletes' weight loss, hydration status, appearance of URTI symptoms, and immunocompetence such as lymphocytes and monocytes to prevent the physical condition from becoming worse.     

Examination of the dose distribution of volumetric modulated arc radiotherapy using a high-definition multi-leaf collimator for breast cancer patients with irradiated regional lymph nodes

BackgroundA high-definition multi-leaf collimator (HD-MLC) with 5- and 10-mm fine MLCs is useful for radiotherapy. However, it is difficult to irradiate the mammary gland and supraclavicular region using a HD-MLC because of the narrow field of volumetric modulated arc radiotherapy (VMAT). Therefore, we aimed to evaluate the dose distribution of the VMAT dose using a HD-MLC in 15 patients with left breast cancer undergoing postoperative irradiation of breast and regional lymph nodes, including the internal mammary node.Materials and methodsThe following four plans were generated: three-arc VMAT using HD-MLC (HD-VMAT), two tangential arcs and one-arc VMAT using HD-MLC (tHD-VMAT), three-dimensional conformal radiotherapy (3DCRT) using HD-MLC, and two-arc VMAT using the Millennium 120-leaf MLC (M-VMAT). We assessed the doses to the target volume and organs at risk.ResultsThe target dose distributions were higher for HD-VMAT than 3DCRT. There were no significant differences in the heart mean dose (D_mean) or lung volume receiving 20 Gy (V20 Gy) between HD-VMAT and 3DCRT. The heart D_mean and lung V20 Gy of tHD-VMAT were higher than those of HD-VMAT, and the heart D_mean of M-VMAT was higher than that of HD-VMAT. However, the target doses of tHD-VMAT, M-VMAT, and HD-VMAT were equivalent.ConclusionsIn cases of the mammary gland and regional lymph node irradiation, including the internal mammary node in patients with left breast cancer, HD-VMAT was not inferior to M-VMAT and provided a better dose distribution to the target volume and organs at risk compared with 3DCRT and tHD-VMAT.     

C5a controls TLR-induced IL-10 and IL-12 production independent of phosphoinositide 3-kinase

The complement system is a classic central player in innate immunity. Most pathogens activate both complement and the toll-like receptor (TLR) pathway. Therefore, to provide a more comprehensive understanding of innate immunity, it is important to understand the crosstalk between these two systems. Mouse macrophages produce IL-12 and IL-10 in response to TLR ligands such as LPS, CpG, Poly I:C and Malp2. The TLR-induced IL-12 production was decreased, while that of IL-10 was increased by concurrent stimulation with a complement fragment C5a. Pharmacological studies have suggested that C5a regulates TLR4-induced IL-12 production in a phosphoinositide 3-kinase (PI3K)-dependent mechanism. In the present study, however, we found that the C5a-mediated changes can be observed in macrophages from mice lacking PI3K p85α or PI3K p110γ. The result indicates that the C5a action is PI3K-independent; neither class IA nor class IB PI3K subtype is involved in this regulation. The actions of C5a were sensitive to pertussis toxin and PD98059, suggesting a role of G protein-mediated activation of the Erk1/2 pathway.     

Novel metabolism of 1 alpha,25-dihydroxyvitamin D3 with C24-C25 bond cleavage catalyzed by human CYP24A1

Our previous study revealed that human CYP24A1 catalyzes a remarkable metabolism consisting of both C-23 and C-24 hydroxylation pathways that used both 25(OH)D(3) and 1alpha,25(OH)(2)D(3) as substrates, while rat CYP24A1 showed extreme predominance of the C-24 over C-23 hydroxylation pathway [Sakaki, T., Sawada, N., Komai, K., Shiozawa, S., Yamada, S., Yamamoto, K., Ohyama, Y. and Inouye, K. (2000) Eur. J. Biochem. 267, 6158-6165]. In this study, by using the Escherichia coli expression system for human CYP24A1, we identified 25,26,27-trinor-23-ene-D(3) and 25,26,27-trinor-23-ene-1alpha(OH)D(3) as novel metabolites of 25(OH)D(3) and 1alpha,25(OH)(2)D(3), respectively. These metabolites appear to be closely related to the C-23 hydroxylation pathway, because human CYP24A1 produces much more of these metabolites than does rat CYP24A1. We propose that the C(24)-C(25) bond cleavage occurs by a unique reaction mechanism including radical rearrangement. Namely, after hydrogen abstraction of the C-23 position of 1alpha,25(OH)(2)D(3), part of the substrate-radical intermediate is converted into 25,26,27-trinor-23-ene-1alpha(OH)D(3), while a major part of them is converted into 1alpha,23,25(OH)(3)D(3). Because the C(24)-C(25) bond cleavage abolishes the binding affinity of 1alpha,25(OH)D(3) for the vitamin D receptor, this reaction is quite effective for inactivation of 1alpha,25(OH)D(3).