Autophagy and apoptosis of acute myelogenous leukemia U937 cell induced by Sirolimus / 中华实用儿科临床杂志

Objective To investigate the autophagy and apoptosis in acute myelogenous leukemia U937 cell induced by Sirolimus.Methods U937 cells were subcultured, and blank control group(normal) and Sirolimus treated groups(12 h, 24 h,48 h) were established.The Sirolimus treated groups were treated by 2 μmol/L concentration of Sirolimus for 12 h,24 h and 48 h, respectively.The cell morphology of U937 cells treated by Sirolimus was observed after 12 h,24 h and 48 h.The survival rate of cells was detected by cell counting kit-8 method.Cell apoptosis was detected by flow cytometry using Annexin V-FITC/PI double labeled.Real-time PCR was used to detect the level of mRNA expression in autophagy specific protein maker mictotubule-associated protein light chain 3 (LC3)-Ⅱ in different treated times by Sirolimus.Sirolimus LC3 protein expression levels after treatment were detected by Western blot method.Results Under inverted microscope, the cell number of Sirolimus treatment group reduced gradually after 12 h ,24 h and 48 h culture, volume of cells became smaller, cells got ruptured, and the nucleus pycnosis and cellular debris increased.With the extension of time, U937 cells survival rate was falling, and there was statistical differences compared with those of the control group(P =0.031).With Sirolimus treatment, U937 cells after 12 h,24 h and 48 h, U937 cell apoptosis rate increased, and there were statistically significances, compared with those of the control group (P =0.027).With Sirolimus treatment U937 cells after 12 h,24 h and 48 h,LC3-Ⅱ mRNA expression and protein expression were down-regulated compared with those of the control group, and there were statistically significances (P =0.029).Conclusions Sirolimus can induce autophagy and apoptosis in U937 cells.Autophagy protein LC3-Ⅱ in gene and protein expression levels were lowered, and LC3-Ⅱ may play an important role in regulating the leukemia cell autophagy.

Association between some cytokines and graft-versus-host disease after allogeneic hematopoietic stem cell transplantation for beta-thalassemia major / 中国组织工程研究

BACKGROUND:Cytokines play an important role in the occurrence and development of graft-versus-host disease, but there is a current lack of reports on the association between cytokines and graft-versus-host disease after al ogeneic hematopoietic stem cel transplantation for treatment ofβ-thalassemia major. OBJECTIVE:To investigate the association between cytokines and graft-versus-host disease after al ogeneic hematopoietic stem cel transplantation forβ-thalassemia major. METHODS:We observed the dynamic variation of interleukin 6, interleukin 8, interleukin 12, tumor necrosis factor-αand macrophage migration inhibitory factor in 11 children withβ-thalassemia major before onset of graft-versus-host disease, when graft-versus-host disease occurred, at days 4 and 7 after onset of graft-versus-host disease, and when graft-versus-host disease disappeared. RESULTS AND CONCLUSION:There was a significant difference in serum levels of interleukin-6, interleukin-12, tumor necrosis factor-α, macrophage migration inhibitory factor in different time points, and the highest levels of different cytokines appeared when graft-versus-host disease occurred, fol owed by those at 7 days after graft-versus-host disease. There was a significant difference in serum levels of interleukin-8 in different time points, and the highest level appeared at 4 days after graft-versus-host disease. The dynamic expression of interleukin-6, interleukin-8, interleukin-12, tumor necrosis factor-α, macrophage migration inhibitory factor can estimate the immune function ofβ-thalassemia major patients who develops graft-versus-host disease after al ogeneic hematopoietic stem cel transplantation, and can be used as the immunobiology indicators for the early diagnosis of graft-versus-host disease.

Value of magnetic resonance imaging T2* tests in detecting heart and liver iron overload in patients with β-thalassemia major / 南方医科大学学报

<p><b>OBJECTIVE</b>To assess the value of magnetic resonance imaging T2* tests in the detection of myocardial and liver iron overload in patients with β-thalassemia major (β-TM).</p><p><b>METHODS</b>From 2010 to 2011, 28 β-TM patients over 10 years old under blood transfusion therapy and chelation care with serum ferritin (SF)>1000 µg/L underwent myocardial and liver MRI T2* tests on a voluntary basis. The results were analyzed in relation with age, SF, and left ventricular ejection fraction (LVEF).</p><p><b>RESULTS</b>Fourteen out of the 28 cases (50%) were found to have myocardial iron overload, including 7 severe cases, 2 moderate cases, and 5 mild cases. All the 28 cases had liver iron overload, including 2 mild cases, 7 moderate cases, and 19 severe cases. Two out of the 28 cases had lowered LVEF (7.14%), and one of them had severe myocardial iron overload. There was a negative correlation between myocardial MRI T2* and SF (r=-0.479, P=0.01). Myocardial MRI T2* was positively correlated with liver MRI T2* (r=0.378, P=0.047). Age was not significantly correlated with SF, LVEF, or liver MRI T2*.</p><p><b>CONCLUSION</b>Magnetic resonance imaging (T2*) detection is an effective and non-invasive means for detecting myocardial and liver iron overload in patients with β-thalassemia major receiving blood transfusion. T2* combined with SF is the main diagnostic indicator to assess iron overload in the vital organs.</p>

Pretreatment doses of antithymocyte globubin-fresenius for allogeneic hematopoietic stem cell transplantation for beta-thalassemia major / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effects of different doses of antithymocyte globubin-fresenius (ATG-F) for allogeneic hematopoietic stem cell transplantation (allo-HSCT) in patients with beta-thalassemia Major.</p><p><b>METHODS</b>Sixty-four children with beta-thalassemia major undergoing allo-HSCT were divided into two equal groups to receive ATG-F pretreatments at high (30 mg/kg) or low (15 mg/kg) doses as part of the conditioning regimen including mainly cyclophosphamide, busulfan, fludarabine, and thiotepa. The outcomes of the patients were compared between the two groups.</p><p><b>RESULTS</b>No obvious difference were noted in the time to leukocyte and platelet engraftment between the two groups. The incidence of grade II-IV acute graft-versus-host disease (aGVHD) appeared to be higher in the low-dose group than in the high-dose group (12.5% vs 9.4%). The incidence of grade III-IV aGVHD was also higher in the low dose group (12.5% vs 6.3%), but the difference was not statistically significant. Application of high-dose ATG-F was associated with a higher rate of probable and possible fungal infection (P<0.05).</p><p><b>CONCLUSION</b>The two doses of ATG-F is feasible as a part of the conditioning regimen for allo-HSCT in children with beta-thalassemia major.</p>

Impact of cytomegalovirus infections on T lymphocyte subsets in children with β-thalassemia major early after allogeneic hematopoietic stem cell transplantation / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of human cytomegalovirus (HCMV) infection on T lymphocyte subsets in children with β-thalassemia major (TM) during the initial 6 months after allogeneic hematopoietic stem cell transplantation (Allo-HSCT).</p><p><b>METHODS</b>From January, 2010 to January, 2011, 35 children with TM underwent Allo-HSCT. Peripheral blood samples were obtained from the children 6 month after the transplantation to examine the changes of T lymphocytes subsets in relation to HCMV seropositivity.</p><p><b>RESULTS</b>Thirteen children were found seropositive and 22 were seronegative for HCMV. The HCMV-seropositive children had a higher CD8⁺ cell percentage but a lower CD4⁺ cell percentage than those without HCMV infection. Compared with those seronegative for HCMV, the children with HCMV seropositivity showed increased percentages of CD8⁺ cells and CD8⁺CD28⁻ cells with a decreased percentage of CD8⁺CD28⁺ cells. A positive linear correlation was found between the percentages of CD8⁺CD28⁻ cells and CD8⁺ cells.</p><p><b>CONCLUSION</b>HCMV infection can lead to the accumulation of CD8⁺CD28 cells to cause increased CD8⁺ T cells in the peripheral blood in TM children after Allo-HSCT. The percentages of CD8⁺CD28⁻ cells has a positive linear correlation to that of CD8⁺ cells.</p>

Exploration on cultivation of clinical thinking for eight-year program medical students in during clinical internship / 中华医学教育探索杂志

Pediatrics internship is a bridge that brings medical theory into clinical reality.Cultivate systematic clinical thinking during internship is the key to the growth of clinical doctors.Good outcome has been achieved among these eight-year medical students by using teaching methods such as case discussions,lectures,teacher instructions,which can cultivate proper clinical thinking and make students more active.

Immune-ablative and tolerance inducing therapy for animal models of polymyositis / 中国组织工程研究

BACKGROUND: According to present theories and our clinical experience, immune ablative and tolerance inducing theory is proposed. Immune ablative means to clear out mutate cell clones and without transfusion of hemopoietic stem cells afterwards; intolerance inducing means to induce animal models not to react to mutate somatic cells, which avoids relapse or new occurrence of autoimmune disease. OBJECTIVE: To explore the effects of immune-ablative and tolerance inducing therapy in treating animal model of immune polymyositis (PM). DESIGN, TIME AND SETTING: Randomized, controlled animal experiment was performed at the Animal Experimental Center of Nanfang Hospital from December 2008 to April 2009. MATERIALS: One New Zealand rabbit, female, weighing 4.1 kg and 36 England guinea pigs, female, weighing 400-500 g, were used. METHODS: New Zealand rabbit's muscle tissue homogenate and complete Freund's adjuvant (CFA) were injected into guinea pigs to make PM animal models. The 28 animal models were randomly divided into intense immune-ablative and tolerance inducing group (Busulfan 1 mg/kg, every 12 hours, totally 8 doses; followed by CTX 40 mg/kg per day for 4 days; then cyclosporine A (CsA) 3 mg/kg per day was given till animals were dead); cyclophosphamide (CTX) group: CTX was given, 10 mg/kg per day for 3days; immune-ablative and tolerance inducing group: Busulfan 0.8 mg/kg, CTX 30 mg/kg, CsA 3 mg/kg; the administration time and dose were the same as group 1. Control group was not treated.MAIN OUTCOME MEASURES: Full blood count (FBC) and biochemical index were tested before and after treatment, and surviving time was recorded. In addition, muscle pathological changes were observed.RESULTS: Compared with control group, number of white cells was significantly decreased in the other groups, and hematopoiesis function gradually restored after administration. The number of white cells in the immune-ablative and tolerance inducing group was the most, and striated muscle pathology showed PM. Following administration, the glutamic oxaloacetic transaminase and creatine kinase of intense immune-ablative and tolerance inducing and immune-ablative and tolerance inducing groups were significantly reduced (P < 0.05, P < 0.01), but no obvious striated muscle pathological changes were found. The glutamic oxaloacetic transaminase, lactic dehydrogenase and creatine kinase in the CTX and control groups remained unchanged. Survival time of intense immune-ablative and tolerance inducing group was the shortest among all groups, and there was no significant difference between CTX and control groups. The animals in immune-ablative and tolerance inducing group survived for the longest time. CONCLUSION: Immune-ablative and tolerance inducing therapy has preferable effect on treating animal models of PM, and its prognosis is better than intense immune-ablative and tolerance inducing therapy and regular CTX therapy.