Identification of two novel mitochondrial DNA deletions induced by ionizing radiation / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>We identify ionizing radiation-induced mitochondrial DNA (mtDNA) deletions in human lymphocytes and their distribution in normal populations.</p><p><b>METHODS</b>Long-range polymerase chain reactions (PCR) using two pairs of primers specific for the human mitochondrial genome were used to analyze the lymphoblastoid cell line following exposure to 10 Gy (60)Co γ-rays. Limited-condition PCR, cloning and sequencing techniques were applied to verify the mtDNA deletions detected with long-range PCR. Human peripheral blood samples were irradiated with 0, 2 and 6 Gy (60)Co γ-rays, and real-time PCR analysis was performed to validate the mtDNA deletions. In order to know the distribution of mtDNA deletions in normal population, 222 healthy Chinese adults were also investigated.</p><p><b>RESULTS</b>Two mtDNA deletions, a 7455-bp deletion (nt475-nt7929 in heavy strand) and a 9225-bp deletion (nt7714 -nt369 in heavy strand), occurring between two 8-bp direct repeats, were identified in lymphoblastoid cells using long-range PCR, limited-condition PCR and sequencing. These results were also observed for (60)Co γ-rays irradiated human peripheral blood cells.</p><p><b>CONCLUSION</b>Two novel mtDNA deletions, a 7455-bp deletion and a 9225-bp deletion, were induced by ionizing radiation. The rate of the mtDNA deletions within a normal population was related to the donors' age, but was independent of gender.</p>

Role of dissection of secondary branches of splenic pedicle in portal hypertension cases undergoing splenectomy / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>It is well known that conventional splenectomy, which requires careful handling and ligation of tissue of the splenic hilum, can easily cause complications such as splenic fever and pancreatic fistula. Here, we use the technique of dissection of the secondary branches of the splenic pedicle to handle the hilum in the portal hypertension patients who are subjected to splenectomy.</p><p><b>METHODS</b>We retrospectively compared and analyzed the complications, postoperative hospital stay, operative time, and occurrence of hemorrhage in 121 patients with portal hypertension undergoing splenectomy and devascularization of the gastric cardia from January 1999 to December 2007. The selected cases consisted of 51 patients undergoing conventional splenectomy and 70 patients undergoing dissection of secondary branches of the splenic pedicle. In addition, we analyzed the relationship between size of the spleen and occurrence of complications.</p><p><b>RESULTS</b>The incidence of pancreatic fistula and splenic fever (0/70 and 9/70) was lower in patients undergoing dissection of secondary branches of the splenic pedicle as compared with that of the conventional group (5/51 and 18/51 respectively). In addition, there was no significant difference in operative time and volume of blood loss between two groups. The spleen thickness of those patients who had pancreatic fistula and splenic fever was significantly greater than those without complications.</p><p><b>CONCLUSIONS</b>These results indicate that dissection of secondary branches of the splenic pedicle in portal hypertension patients undergoing splenectomy can decrease the incidence of splenic fever and pancreatic fistula, and shorten the postoperative hospital stay, especially in the patients with a large spleen. So dissection of secondary branches of the splenic pedicle is a valuable technique for splenectomy.</p>

Detection of chromosome aberrations in Chinese children with autism using G-banding and BAC FISH / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To detect the characteristic chromosomal changes in Chinese children with infantile autism.</p><p><b>METHODS</b>Chromosome aberrations in 68 cases of infantile autism were analyzed by high-resolution G-banding and fluorescence in situ hybridization (FISH) with bacterial artificial chromosome (BAC) clones.</p><p><b>RESULTS</b>Chromosomal changes were detected in 4 cases by high-resolution G-banding: one case with t(4;6)(q23-24;p21), one case with longer p arm of chromosome 21 (21p+), and two cases with pericentric inversion of chromosome 9 (inv(9)) which was confirmed by C-banding. BAC FISH analysis was performed to confirm these observations and changes in chromosomes 2, 7 and 15, which are often found in autistic children. There could exist the translocation of t(4;6) (q25-26;p21.1). Chromosome changes often reported previously in chromosomes 2, 7 and 15 were not detected in this study. Inv(9) and 21p+ were not confirmed with present BAC clones.</p><p><b>CONCLUSION</b>Chromosomal changes were detected in four cases of infantile autism, with a detectability of 5.9% , far lower than that (10% to 48%) reported in literature. The breakpoint of translocation could be detected more accurately using BAC FISH method.</p>