Machine Learning-based Identification of the Sites of DNA Double-Strand-Break in the Human Genome / 中国生物化学与分子生物学报

DNA double-strand break(DSB) is a serious form of DNA damage in cells, which is closely related to a variety of genomic instability diseases, including cancer, abnormal recombination and neuronal development. Due to the limitations of cost and technical threshold, high-resolution DSB mapping by high-throughput sequencing technology is very limited. This hinders our understanding of the DSB situation in the genomes of different species. Therefore, we developed a classification prediction model based on random Forest(RF), support vector machine(SVM) and logistic regression(LR) classifiers to predict DSB loci in the whole genome of human NHEK cells. In addition to the epigenetic features and DNA shape features commonly used in previous prediction studies, we found that DNA sequence features(kmer frequency, GC content, GC-skew, Mutual Information) can also characterize DSB sites. At the same time, the prediction accuracy is improved after considering DNA physical properties, chemical shifts and autocorrelation information. After combining all the above features, logistic regression(LR) has the best prediction performance(AUC = 0. 97), which is comparable to previous prediction(AUC = 0. 964). In addition, the optimal feature collection consisting of 294 features was obtained by the incremental feature search method, and the corresponding AUC value reached 0. 974.

Hypertriglyceridemia: A Neglected Risk Factor for Ischemic Stroke? / 대한뇌졸중학회지

Hypertriglyceridemia is caused by defects in triglyceride metabolism and generally manifests as abnormally high plasma triglyceride levels. Although the role of hypertriglyceridemia may not draw as much attention as that of plasma cholesterol in stroke, plasma triglycerides, especially nonfasting triglycerides, are thought to be correlated with the risk of ischemic stroke. Hypertriglyceridemia may increase the risk of ischemic stroke by promoting atherosclerosis and thrombosis and increasing blood viscosity. Moreover, hypertriglyceridemia may have some protective effects in patients who have already suffered a stroke via unclear mechanisms. Therefore, further studies are needed to elucidate the role of hypertriglyceridemia in the development and prognosis of ischemic stroke.

Clinical study on bacterial colonization on double J tube in pregnant women / 中国感染控制杂志

Objective To explore species distribution of bacteria colonizing the indwelling double J tube in pregnant women.Methods From March2013 to December 2017, patients with double J tube during pregnancy in urology department of a hospital were collected.According to the time of indwelling double J tubes, they were divided into group A (indwelling time≤1 month) and group B (indwelling time＞1 month).All patients underwent bladder urine and double J tube bacterial culture before and after extubation.Species and positive detection rates of bacteria in bladder urine and double J tube between two groups were compared and analyzed.Results A total of 237 pregnant women with ureteral obstruction were included in the study, 129 cases in group A and 108 in group B.A total of 78 strains of bacteria were isolated in double J tube culture, 35 strains in group A and 43 in group B.Gram-negative bacilli were predominant in both groups, accounting for 54.29％ and 67.44％ respectively, followed by grampositive cocci, accounting for 37.14％ and 25.58％ respectively;isolated bacteria were Escherichia coli (n=30), Enterococcus spp. (n=12), Staphylococcus spp. (n=12), Klebsiella pneumoniae (n=11), Pseudomonas aeruginosa (n=7) and so on.Positive rate of double J tube bacterial culture was higher than that of bladder urine culture in both group A and group B, difference were both statistically significant (both P＜0.05).Positive rate of double J tube bacterial culture in group B was higher than that in group A (39.81％ VS 27.13％, P＜0.05), but there was no significant difference in the positive rate of bladder urine culture between group A and group B (P＞0.05).Conclusion The main colonized bacteria for pregnant women who are inserted double J tubes are gram-negative bacilli, the longer time the double J tube is placed, the higher rate the bacteria colonize and the higher positive of bacterial culture.

Role of HMGB1 in Post-traumatic Endoplasmic Reticulum Stress in Rat Lung Tissues / 法医学杂志

OBJECTIVES@#To explore the role of high mobility group B1 （HMGB1） protein in the post-traumatic endoplasmic reticulum stress （ERS） in rat lung tissues.@*METHODS@#The rat model of acute lung injury was established by crushing the hind limbs of rats with standard weight. The first experiment was to divide rats into postural control group and crush groups （6 h, 18 h and 30 h after crushing）. The second experiment was to divide rats into postural control group, 18 h crush group, HMGB1 inhibitor sodium butyrate （SB） group and 18 h crush+SB group. The protein expression changes of HMGB1 and ERS- related proteins （GRP78, caspase-12, CHOP and IRE1α） in rat lung tissues were detected with Western blotting. Meanwhile, the pathological changes of rat lungs were observed by HE stain.@*RESULTS@#Compared with the postural control group, the expression levels of ERS-related proteins （GRP78, caspase-12, CHOP and IRE1α） and HMGB1 protein in rat lung tissues by crushing the hind limbs of rats were obviously increased. The protein levels reduced at 30 h after crushing but were still higher than those of postural control group and obvious pathological changes of acute lung injury were observed simultaneously in rats. Compared with the 18 h crush group, the expression levels of the ERS-related proteins and HMGB1 protein in rat lung tissues were attenuated in 18 h crush+SB group, and the pathological changes of rat lung injury began to alleviate.@*CONCLUSIONS@#HMGB1-ERS pathway activated by traumatic stress can lead to acute lung injury in rats.

Myocardial expression of Spry1 and MAPK proteins of viral myocarditis / 法医学杂志

OBJECTIVE@#To discuss the myocardial expression of Spry1 and MAPK proteins of viral myocarditis (VMC), to reveal its mechanism of sudden death, and to provide guides for forensic identification of sudden cardiac death.@*METHODS@#Thirty Balb/c male mice were randomly divided into VMC group and control group, inoculated intraperitoneally with Coxsackievirus B3 and Eagel's solution, respectively. After the mice were sacrificed, the cardiac tissues of the mice were taken to proceed regular pathological examination. The changes of Spry1 protein, Spry1 mRNA and MAPK protein were detected by immunohistochemistry, Western blotting and real-time PCR.@*RESULTS@#Under light microscope, the pathologic changes included myocardial interstitial edema, inflammatory cells infiltration, myocardial necrosis, and focal and patchy necrosis of myocardial fiber in VMC group. The expression of Spry1 protein in VMC group was lower than that in control group (P < 0.05). There was slightly decreased expression of Spry1 of the mRNA level in VMC group (P > 0.05). But the MAPK protein expression in VMC group was higher than that in control group (P < 0.05).@*CONCLUSION@#The pathway of MAPK/ERK involving Spry1 protein accelerates the expression of collagen, which may contribute to arrhythmia, heart failure and even sudden cardiac death.

Expression of CAR in myocardial of viral myocarditis and dilated cardiomyopathy / 法医学杂志

OBJECTIVE@#In order to improve accuracy and reliability of forensic diagnosis of sudden cardiac death, pathogenesis and relationship between the viral myocarditis (VMC) and dilated cardiomyopathy (DCM) were investigated.@*METHODS@#Improved immunohistochemical technique was used to detect the expression of the CAR in myocardium samples, including 22 deceased with VMC, 20 deceased with DCM and 16 control deceased.@*RESULTS@#The brown staining on the cell membrane of myocardium showed positive result. There was a prominent CAR expression in VMC group and DCM group, which were statistically significant difference compared with control group (P < 0.05).@*CONCLUSION@#The CAR expression showed significantly higher in VMC and DCM groups. The viral infection can result in myocardial necrosis and impaired cardiac functions. These abnormalities can trigger a cascade of events that contributed to the progress of VMC to DCM.

Protection against hydrogen peroxide-induced cytotoxicity in PC12 cells by guggulsterone / 药学学报

The present study is to investigate the protective actions of guggulsterone against the cytotoxicity produced by exposure to hydrogen peroxide (H2O2) in PC12 cells. It was evaluated by MTT [3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyl-tetrazolium bromide] reduction assay, lactate dehydrogenase (LDH) release assay, and the release of nitric oxide (NO). ROS and Ca2+ in cells were evaluated by DCFH and Fura 2-AM, respectively. Mitochondrial membrane potential (MMP) was assessed by the retention of rhodamine 123 (Rh 123). Apoptosis and morphological alteration in PC12 cells were monitored with flow cytometry and electric microscope. Vitamin E, a potent antioxidant, was employed as a comparative agent. The results showed that preincubation of PC12 cells with guggulsterone (0.1 - 10 micromol x L(-1)) prevented cytotoxicity induced by H2O2. Extracellular accumulation of LDH, NO and intracellular accumulation of ROS, Ca2+ resulting from H2O2 were significantly reduced by guggulsterone. Incubation of cells with H2O2 caused a marked decrease in MMP, which was significantly inhibited by guggulsterone. The percentage of H2O2-induced apoptosis in PC12 cells was 24.3%, and decreased in the presence of guggulsterone (0.1 - 10 micromol x L(-1)) by 18.4%, 15.9%, 11.8%, respectively. Guggulsterone exhibited comparable potency against oxidative stress induced by H2O2 in PC12 cells as that of vitamin E. The present findings showed that guggulsterone attenuated H2O2-induced cytotoxicity, extracellular accumulation of LDH and NO, intracellular accumulation of ROS and Ca2+, loss of MMP, and apoptosis, which may represent the cellular mechanisms for its neuroprotective action.

Effects of paeoniflorin on pathological changes in global brain ischemia model rats / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the effects of paeoniflorin on blood brain barrier and pathological changes in brain ischemia.</p><p><b>METHOD</b>Mice were divided into sham operation group, model group, positive control group-Deng zhanhua tablet group and three different dose (high, middle, low-dose) groups of paeoniflorin. The neurological symptoms of rats were observed. The SOD of ischemic brain tissue, MDA BBB and EAA contents were determined. The ultrastructure on the brain cells was inspected by transmission electron microscope.</p><p><b>RESULT</b>Paeoniflorin had the protetive effects on 4VO model of total cerebral ischemia. Paeoniflorin could obviously increase SOD content, reduce MDA content in rat brain-tissue and alleviate oxidative stress damage by cerebral ischemia on rat brain. Paeoniflorin could improve pathological changes of cell nuclear, perikaryon, mitochondria and myelin sheath, which was the morphologic basis of the protective effect on ischemia. Paeoniflorin could alleviate the incrense of EAA content caused by and hypoxia and inhibit the excitatory neural toxicity by EAA.</p><p><b>CONCLUSION</b>Paeoniflorin has the protection effect on the brain edema after cerebral ischemia, the oxidative stress damage on brain tissue, the ultrastructure lesions of cells and the BBB. The protective mechanism may be related to inhibiting intracellular calcium overload, anti-free radical and reducing EAA content.</p>

A comparative study of Gd-DTPA and HSA-Gd-DTPA in magnetic resonance lymphography / 南方医科大学学报

<p><b>OBJECTIVE</b>To compare the effects of two contrast agents, Gd-DTPA and HSA-Gd-DTPA, in magnetic resonance (MR) lymphography.</p><p><b>METHODS</b>Twelve New-Zealand rabbits were randomized into Gd-DTPA and HSA-Gd-DTPA groups with subcutaneous (interdigital skin fold) injection of the two contrast agents (0.2 ml of 0.5 mmol/L Gd(3+)) for MR lymphography of the popliteal lymph nodes examined in the axial and sagital orientation. T(1)-weighted, T1-weighted fat suppressed, and T(2)-weighted spin-echo (SE) images of the lymph nodes were obtained in plain scans. The post-contrast scanning started at 30 min, 1 h and 3 h after Gd-DTPA administration and at 10 min, 30 min and 60 min after HSA-Gd-DTPA injection to obtain T(1)-weighted images with identical imaging parameters. The signal intensity of popliteal lymph node was measured and the enhancement rate calculated.</p><p><b>RESULTS</b>After subcutaneous injection, Gd-DTPA quickly entered blood circulation to result in obvious enhancement of the anterior-tibial vein and the urine and also in heterogeneous enhancement of the popliteal lymph nodes. HSA-Gd-DTPA did not enter the blood, causing obvious homogeneous enhancement of the lymphatic vessels and lymph nodes. HSA-Gd-DTPA resulted in higher enhancement rate than Gd-DTPA, and the enhancement rate in Gd-DTPA group decreased with time as opposed to that of the HSA-Gd-DTPA group.</p><p><b>CONCLUSION</b>HSA-Gd-DTPA has better performance than Gd-DTPA in MR lymphography after subcutaneous administration.</p>

Relevant factors of lymphatic metastasis in rectal carcinoma / 中南大学学报(医学版)

OBJECTIVE@#To investigate the rules of lymphatic metastasis of rectal carcinoma, and to help clinical diagnosis and treatment.@*METHODS@#A retrospective analysis was performed in the 979 patients with rectal carcinoma who underwent surgical resection from 1995 to 2004. The associations between lymphatic metastasis and clinicopathologic variables were evaluated by Chi-squared test and logistic regression.@*RESULTS@#The rate of lymph node metstasis was 71.4% for patients younger than 30 years old, 40.7% in the patients with tumor diameters over 6 centimeters, 82.5% in the patients with extraneous tumor invasion, 71.6% for patients of poor-differentiated adenocarcinoma, 70.4% for patients with mucoid adenocarcinoma, 100% for patients with signet-ring cell carcinoma and 46.4% for patients with more than half intestinal circumference invasion. Logistic regression analysis showed that the degree of lymphatic metastasis was related to the differentiating degrees, depths of tumor invasion and intestinal circumference invasion, and the differentiating degree was the major factor.@*CONCLUSION@#The lymphatic metastasis of rectal carcinoma is related to age, tumor size, intestinal circumference invasion, depth of tumor invasion and the differentiating degree of the tumor; the differentiating degree is the major factor.

Effects of paeoniflorin on cerebral energy metabolism, nitric oxide and nitric oxide synthase after cerebral ischemia in mongoliagerbils / 中国中药杂志

<p><b>OBJECTIVE</b>To explore the effects of paeoniflorin on antagonising the delayed neuronal death (DND) induced by cerebral ischemia,and the relation between DND, cerebral tissue energy metabolism, nitric oxide (NO) and nitric oxide synthase (NOS).</p><p><b>METHOD</b>Incomplete cerebral ischemia induced was induced by ligating bilateral arteries carotis communis for 20 min followed by reperfusion 48 h in rats. The indexes including Na(+)-K(+)-ATPase activity, lactic acid content, Ca(2+)-ATPase, Mg(2+)-ATPase activity, NO content and NOS activity were determined in fore brain cortex at 48 h after reperfusion.</p><p><b>RESULT</b>Na(+)-K(+)-ATPase, Ca(2+)-ATPase and Mg(2+)-ATPase activity were lowered (P < 0.01), NO level was decreased (P < 0.01), NOS activity dropped (P < 0.01) in cerebral tissue at 48h after reperfusion, but lactic acid level had no change. Paeoniflorin could prevent reduction of Na(+)-K(+)-ATPase activity (P < 0.05, P < 0.01), increase NO level (P < 0.01), enhance NOS activity (P < 0.01) at 48h after reperfusion.</p><p><b>CONCLUSION</b>DND induced by ischemia may be concerned with energy metabolism disorder and decrease of NO formation. Paeoniflorin may play the role of antagonising cerebral ischemia by adjusting cerebral energy metabolism and nitric oxide formation.</p>

One stage repairing operation in neonatal hypospadias / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the feasibility of one stage repairing operation on hypospadias in neonatal.</p><p><b>METHODS</b>Sixteen newborn infants with congenital hypospadias dated from May 1998 to Jun. 2004, who was 1 to 29 days old with average 13 days, were performed one stage repairing operation, among whom hypospadias were classified: 4 cases of type I hypospadias, 8 cases of type II, 3 cases of type III and 1 case of type IV.</p><p><b>RESULTS</b>Fourteen cases were cured, 1 case had urethral stricture, and 1 case had fistula. The cure rate of one stage operation was 87.5% (14/16).</p><p><b>CONCLUSION</b>On the premise of the anesthetic safety, one stage hypospadias repairing operation is feasible in some selective cases in neonate.</p>

Reversal of multidrug resistance by lomerizine in K562/ADM cells / 药学学报

<p><b>AIM</b>To study the effect of lomerizine (Lom) on the reversal of multidrug resistance (MDR) in K562/ADM cells and its mechanism.</p><p><b>METHODS</b>MTT assay was used to determine the influence of Lom on the cytotoxicity of adriamycin (ADM). The effect of Lom on the apoptosis induced by ADM and vincristine (VCR) in K562/ADM cells was detected using flow cytometry. Intracellular accumulation of ADM was measured by fluorescence spectrophotometry. Flow cytometry was used to investigate the efflux of rhodamine 123 (Rh123) and the expression of P-glycoprotein (P-gp) in K562/ADM cells.</p><p><b>RESULTS</b>Lom increased the cytotoxicity of ADM and the apoptosis induced by ADM or VCR in K562/ADM cells. At the concentration of 3, 10 and 30 micromol x L(-1), Lom reduced the IC50 value of ADM from 79.03 micromol x L(-1) to 28.14, 8.16 and 3.16 micromol x L(-1), respectively. Lom increased the intracellular accumulation of ADM and inhibited the efflux of Rh123 in K562/ ADM cells. No change in P-gp expression was observed after the treatment of Lom for 72 h.</p><p><b>CONCLUSION</b>Lom had strong reversal effect on MDR in K562/ADM cells by inhibiting P-gp function.</p>

Isolation, purification and identification of rat brain microvessels / 中国应用生理学杂志

<p><b>AIM</b>To isolate and purify the brain microvessels without intact neural cells used for cloning specific gene at the blood-brain-barrier.</p><p><b>METHODS</b>Magnetic beads ranging from 200-500 nm were synthesized and infused into cerebral spheres through carotid arteries. The brain tissues were dissected by mechanic and enzymatic methods, and sieved to discharge tissues and large blood vessels. The brain microvessels labelled by magnetic beads were sorted in magnetic fields, and identified by morphology, molecular biology and biologic activity.</p><p><b>RESULTS</b>Scanning electric micrograph of the obtained brain microvessels showed the vessels grossly free of adjoining neural cells except an occasional nerve ending. RT-PCR products of microtube-associated protein 2a, glutamine synthetase and CD31 from brain tissue had positive lanes, but only CD31 had positive lanes from isolated microvessels. The endothelial cells from isolated microvessels had more fluorescence than that from cultured endothelial cells.</p><p><b>CONCLUSION</b>Highly purified microvessels without intact neural cells can be obtained by this method.</p>

Studies on antidiabetic effects of cortex Moutan polysaccharide-2b in type 2 diabetes mellitus rats / 药学学报

<p><b>AIM</b>To study the antidiabetic effects of cortex Moutan polysaccharide-2b (CMP-2b) in type 2 diabetes mellitus (T2DM) rats.</p><p><b>METHODS</b>The T2DM model rats were induced by a single intravenous injection of low dose streptozotocin (STZ) and intake of high sucrose-fat diet. CMP-2b was given to T2DM rats daily through gavage for 4-5 weeks. The body weight, water and food intake, fasting blood glucose (FBG), glucose tolerance, plasma lipids, serum insulin, and insulin receptor (Ins R) were determined.</p><p><b>RESULTS</b>Oral administration of CMP-2b significantly decreased water and food intake, FBG, total cholesterol (Tch), and triglyceride (TG), improved the impaired glucose tolerance (IGT), and remarkably raised the number of low affinity InsR and insulin sensitivity index (ISI) in T2DM rats.</p><p><b>CONCLUSION</b>CMP-2b may be useful for treating T2DM and its complications.</p>

9-(4-ethoxycarbonylphenoxy)-6,7-dimethoxy-1,2,3,4-tetrahydro acridine inhibits free radical induced rat cortical neuron cytotoxicity and cerebral ischemia injury / 药学学报

<p><b>AIM</b>To study the effects of 9-(4-ethoxycarbonylphenoxy)-6,7-dimethoxy-1,2,3,4-tetrahydro acridine (EDT) on free radical induced injury in primary cultured rat cortical neuron and cerebral ischemia in mice.</p><p><b>METHODS</b>In primary rat cortical neuron, free radical injury model was established by 10 mumol.L-1 H2O2. The content of malondiadehyde (MDA) and activity of superoxide dismutase (SOD) in cells were investigated. Chronic cerebral ischemia model was produced by occlusion of one carotid artery and pneumogastric nerve in mice. The step down test was adopted to investigate the effect of EDT on the memory impairment. The cerebra morphology and MDA, NO content and SOD activity in mice cerebra were detected.</p><p><b>RESULTS</b>In primary rat cortical culture, 0.01-3 mumol.L-1 EDT concentration-dependently inhibited the formation of MDA and reduction of SOD activity induced by 10 mumol.L-1 H2O2. In chronic cerebral ischemia, EDT 2.5, 5 and 10 mg.kg-1 ig for 5 d greatly improved the memory impairment, reduced NO efflux and MDA content, while increased SOD activity in mice cerebra.</p><p><b>CONCLUSION</b>EDT was found to protect neurons from H2O2-induced neurotoxicity and inhibit chronic cerebral ischemia mediated injury and memory impairment in mice.</p>

Protective effects of 9-(4-ethoxycarboxylyphenoxy)-6,7-dimethoxy-1,2,3,4- tetrahydro acridine on anoxia and ischemic injury in cultured PC12 cells / 中国临床药理学与治疗学

Aim To investigate the effects of EDT on anoxia and ischemic injury in cultured PC12 cells. Methods Cultured PC12 cells were treated with 1 mmol?L -1 Na 2S 2O 4 and 20 mmol?L -1 NaCN in combination with glucose deprivation. The protective effects of EDT on these two models were evaluated by lactate dehydrogenate (LDH) efflux assay and colormetric MTT assay.ResultsEDT, within the range of 10 -8～ 10 -6 mol?L -1, significantly antagonized LDH efflux induced by two models and increased the optical density at 570 nm tested by colorimetric MTT assay in concentration-dependent manner. 10 -6 mol?L -1 EDT might time-dependently inhibit two injuries and reach maximal level at 48 h. Conclusion EDT can protect PC12 cells from anoxia and ischemic injury.