Background Central nervous system leukemia （CNSL） is an important relapse in children with acute lymphoblastic leukemia （ALL）. We investigated the possible role of endogenous hydrogen sulfide （H2S） of cerebrospinal fluid （CSF） in predicting CNSL. Methods From August 2008 to December 2010, 380 children were enrolled in this study at Shijitan Hospital, China. These children were from 2 to 16 years old, and the median age was 6.5 years. They were divided into a CNSL group （7 cases）, a leukemia group （307 cases）, a non-leukemia group （26 cases） and a healthy group （40 children）. CSF specimens were obtained from conventional lumbar punctured, then centrifuged and supernatants preserved for H2S detection. Leukemic cells precipitates from CSF were found in three cases, the hCSE and hCBS mRNA expression was detected by reverse transcription polymerase chain reaction （RT-PCR）, and H2S levels in serum were also measured. The receiver operating characteristic （ROC） curve and area under curve （AUC） were used to assess the predictive diagnosis role of CSF H2S in children with ALL and CNSL. Results The serum H2S contents of the CNSL and leukemia groups were （96.98±15.77） pmol/L and （93.35±17.16） μmol/L respectively, much higher than those of healthy, （44.29±2.15） pmol/L, and non-leukemia, （46.32±6.54） μmol/L, groups （P 〈0.01）. Compared with the leukemia group, CSF H2S content of the CNSL group was significantly high （P 〈0.01）. Meanwhile, in contrast to the non-leukemia group, CSF H2S contents of the CNSL and leukemia groups were both significantly increased （P 〈0.01）. In addition, leukemic cells from CSF precipitations could express CBS and CSE mRNA. Furthermore, the ROC analysis showed the UAC was 0.929 （95% CI： 0.857-1.000）, and the optimum cut-off value of CSF H2S was 12.08μmol/L, and the sensitivity and specificity were 83.3% and 97.2% respectively. Conclusions CSF H2S contents were significantly increased in children with CNSL. Afte
DU Shu-xuXIAO JiangGUAN FengSUN Li-mingWU Wan-shuiTANG HongDU Jun-baoTANG Chao-shuJIN Hong-fang
Objective To review the vasorelaxant effects of hydrogen sulfide （H2S） in arterial rings in the cardiovascular system under both physiological and pathophysiological conditions and the possible mechanisms involved. Data sources The data in this review were obtained from Medline and Pubmed sources from 1997 to 2011 using the search terms ＂hydrogen sulfide＂ and ＂vascular relaxation＂. Study selection Articles describing the role of hydrogen sulfide in the regulation of vascular activity and its vasorelaxant effects were selected. Results H2S plays an important role in the regulation of cardiovascular tone. The vasomodulatory effects of H2S depend on factors including concentration, species and tissue type. The H2S donor, sodium hydrosulfide （NariS）, causes vasorelaxation of rat isolated aortic rings in a dose-dependent manner. This effect was more pronounced than that observed in pulmonary arterial rings. The expression of KATp channel proteins and mRNA in the aortic rings was increased compared with pulmonary artery rings. H2S is involved in the pathogenesis of a variety of cardiovascular diseases. Downregulation of the endogenous H2S pathway is an important factor in the pathogenesis of cardiovascular diseases. The vasorelaxant effects of H2S have been shown to be mediated by activation of KATP channels in vascular smooth muscle cells and via the induction of acidification due to activation of the Cr/HCO3 exchanger. It is speculated that the mechanisms underlying the vasoconstrictive function of H2S in the aortic rings involves decreased NO production and inhibition of cAMP accumulation. Conclusion H2S is an important endogenous gasotransmitter in the cardiovascular system and acts as a modulator of vascular tone in the homeostatic regulation of blood pressure.
