Arsenic is known as a toxic metalloid, which mainly exists in inorganic forms such as arsenite and arsenate in the natural environment. A number of microorganisms have evolved different resistant mechanisms for arsenic detoxification to cope with the widespread distribution of the poisonous arsenic. Four distinct microbial arsenic-resistant mechanisms have been described including As(III) oxidation, cytoplasmic As(V) reduction, respiratory As(V) reduction, and As(III) methylation. These mechanisms confer arsenic resistance in microorganisms that play important roles in the transformation and geological cycle of arsenic. This review mainly focuses on the researches on these molecular mechanisms and potential application for environmental arsenic bioremediation using microorganisms.

Background Vascular endothelial growth factor(VEGF) has been shown to be associated with the pathogenesis of age-related macular degeneration (AMD),therefore VEGF is a target for the treatment of wet AMD.However,the mechanism of VEGF in the pathogenesis of AMD is not clearly understood.Studying the correlation between VEGF gene polymorphism and AMD is becoming a new research hotspot,but relevant studies on Han Chinese have not been performed.Objective This study was to investigate the association between the VEGF +936C/T gene polymorphism and AMD in the Chinese population.Methods A pilot prospective and nonrandomized controlled trial was designed.This protocol complied with Declaration of Helsinki and was approved by the Ethic Committee of Chinese PLA Second Artillery General Hospital.Written informed consent was obtained from each subject prior to entering the study.Two hundred AMD patients and 200 age-and gender-matched normal controls were enrolled in this study.The genomic DNA was extracted from the peripheral blood samples of the subjects,and analysis of the VEGF polymorphisms at the +936 position in the promoter and 3＇-untranslated regions was performed by the restriction fragment length polymorphism method.Frequencies of the VEGF+936C/T genotype were compared between the two groups,and the risk of the VEGF+936C/T gene polymorphism in pre-disposing AMD was evaluated.Results No significant differences were seen in the incidence rates of smoking(P ＝ 0.76),hypertension(P ＝ 0.84),hyperlipidemia (P=0.71),diabetes mellitus (P=0.86) and cardiovascular disease(P=0.89) between the AMD group and the normal control group,and BMI was matched between the two groups (P =0.18).The prevalence of the TT genotype was 9.0％ (18/200)in the AMD group,but that in the normal control was 3.5％ (7/200),showing a significant difference between the two groups (P =0.03).The odds ratio (OR) was 2.73 with a 95％ confidence interval(CI) of 1.11 to 6.68 for AMD in this genotype.The CC and CT genotypes were not significantly different between the two groups (P =0.52,P =0.57).The genotype frequency and allele frequency conformed to HardyWeinberg equilibrium law.There were no significant differences found in the CC,CT,TT genotype frequencies among the early AMD,geographic atrophy AMD and choroidal neovascular AMD (all at P＞0.05).Conclusions The VEGF+936TT genotype is associated with AMD in Han Chinese population.

Background Various studies demonstrated that the apoptosis of lens epithelial cells(LECs) is associated with the overexpression of the c-myc gene in LECs induced by galactose.Inhibiting the abnormal expression of the c-myc gene in LECs is an effective approach to mitigate the pathogenesis and development of cataract.Objective The goal of this study is to investigate the inhibitory effects of c-myc antisense oligodeoxynucleotide(c-myc ASODN) on the apoptosis of LECs in the eye with galactose-induced cataract.Methods Galactose-induced cataract models were established by the retrobulbar injection of 0.2 mL of 20% galactose once per day.Lipo-antisense oligodeoxynucleotide(Lipo-ASODN,0.2 mL) was retrobulbarly injected 4 hours after the injection of galactose at one-day intervals.The animals were sacrificed and lenses were obtained to evaluate the apoptosis of LECs and the effect of c-myc ASODN on LECs apoptosis induced by galactose was examined by TUNEL assay after 7,14 and 24 days.The ultrastructural changes of LECs were examined under the transmission electron microscopy(TEM).Results A significant difference in the apoptotic rate of LECs was found among the 7 day,14 day and 24 day groups(F_(7 days)=3 418.495,P＜0.01;F_(14 days)=1137.555,P＜0.01;F_(24 days)=2198.871,P＜0.01).The apoptotic rate of LECs in the galactose group was markedly higher than that in the normal saline solution group 7 days,14 days and 24 days after the experiment(P＜0.01).The apoptotic rate of LECs in the galactose+lipo+ ASODN group significantly declined in comparison to the galactose group after 7 days,14 days and 24 days(P＜0.05).TUNEL assay showed the condensation,breakage and irregularity of the nuclei of apoptotic cells in the galactose group.The destruction of the ultrastructure of the cells and organelles were observed under the transmission electron microscope.Conclusion Galactose induces apoptosis of LECs in cataractogenesis.C-myc ASODN inhibits apoptosis of LECs induced by galactose.

Halophilic microorganisms play important rules in salt field ecosystem and salt production. In this study, halophilic bacteria and haloarchaea from soils of Lianyungang Taibei and Yancheng Sanwei salt fields were analyzed. The halophilic bacterial and haloarchaeal types from both the soils were similar, but each soil had its distinctive species. A total of 17 halophilic bacteria were identified, among them, Halomonas was found from both the soils, while Pontibacillus and Halobacillus were isolated from Sanwei salt field only. Using uncultured 16S rRNA gene library technology, 13 haloarchaeal soil 16S rRNA genes were identified from both the saline soils. Halobacterium and Haloplanus were found from Taibei salt field, while Halobac- terium, Natronobacterium, Halogeometricum and Haloarcula were identified from Sanwei salt field. Ten haloarchaeal 16S rRNA gene sequences showed 92%~97% identities with the GenBank sequences that ap- pear to represent novel soil haloarchaeal species. This study provides important information that is useful for further investigation and application of halophiles of saline soil fields.

Objective To evaluate the efficiency of second trimester screenings for Down syndrome using alpha-fetoprotein and β-human chorionic gonadotropin duplex.MethodsPregnant women of south Zhejiang were screened for Down syndrome fetuses by maternal alpha-fetoprotein and β-human chorionic gonadotropin duplex during second trimester.The high-risk women underwent prenatal diagnosis by amniocentesis,cell culture and chromosome analysis.The newborns followed up by the maternal and child tertiary health care network and suspected to have Down syndrome were diagnosed by peripheral blood chromosome analysis.Statistical analysis was performed using two-sample t test and x2 test.Risk probability of Down Syndrome was calculated by random screening software. Results From Oct.2007 to May 2009,1130 of 32 188 singleton pregnant women in second trimester received prenatal screening were discovered with high risk(≥1 ∶ 270).Prenatal diagnosis was performed in 90.79％ cases (1026/1130) of high risk women and seven fetuses were diagnosed as Down syndrome by amniotic fluid chromosome analysis,and the pregnancies were terminated.Among the other 104 cases without prenatal diagnosis one Down syndrome baby was delivered.Six of 31 058 pregnancy women with low risk delivered Down syndrome babies with the incidence of Down syndrome of 0.19‰ (6/31 058).Detection rate of second trimester screenings for Down syndrome using alpha-fetoprotein and β-human chorionic gonadotropin duplex was 57.14％(8/14).False positive rate was 3.48％ (1122/32 188).Positive predictive value was 7.08‰(8/1130).During the same period,there were 23 813 pregnant women who didn't receive screening and 15 fetuses with Down syndrome were diagnosed after birth.There was no statistical difference in the prevalence rate of Down syndrome between those pregnant women who received prenatal screening or not [0.43‰ (14/32 188) vs 0.63‰ (15/23 813),x2 =1.004,P＞0.05].The prevalence of Down syndrome was 0.52‰ (29/56 001) in this area. ConclusionsThe prenatal screening and diagnosis could reduce the birth rate of Down syndrome patients.However,detection rate,false positive rate and positive predictive value of which were lower than reports in other studies.It's possible that the reference data might be not suitable for Chinese.

OBJECTIVETo analyze the complications of percutaneous kyphoplasty except bone leakge for the treatment of osteoporotic thoracolumbar vertebral compression fractures.

METHODSFrom October 2008 to October 2012,178 patients with 224 osteoporotic vertebral compression fractures were treated with percutaneous kyphoplasty under local anethsia. There were 72 males and 106 females,ranging in age from 58 to 92 years old,with an average of 75.3 years,including 93 thoracic vertebrae and 131 lumbar vertebrae. The complications except bone cement leakage were analyzed during operation and after operation.

RESULTSAll operations were successful and all patients were followed up from 12 to 60 months with an average of 26.2 months. No death was found. Bone cement leakage occurred in 27 cases, about 15.1% in 178 cases; and complications except bone cement leakage occurred in 15 cases. There was 1 case with cardiac arrest,was completely recovery by cardiopulmonary resuscitation (CPR) immediately; and 1 case with temporary absence of breathing,was recovery after treatment. There were 3 cases with fall of blood pressure and slower of heart rate; 1 case with intestinal obstruction; 2 cases with local hematoma and 1 case with intercostal neuralgia. Vertebral body fractures of 2 cases were split by bone cement and the fractures of adjacent body occurred in 4 cases.

CONCLUSIONIt's uncommon complication except bone cement leakge in treatment of osteoporotic thoracolumbar vertebral compression fractures with percutaneous kyphoplasty. The complication of cardiopulmonary system is a high risk in surgery; and cytotoxicity of bone cement,nervous reflex,fat embolism and alteration of intravertebral pressure may be main reasons.

Aged ; Aged, 80 and over ; Female ; Fractures, Compression ; surgery ; Humans ; Kyphoplasty ; adverse effects ; Lumbar Vertebrae ; injuries ; surgery ; Male ; Middle Aged ; Osteoporotic Fractures ; surgery ; Postoperative Complications ; etiology ; Spinal Fractures ; surgery ; Thoracic Vertebrae ; injuries ; surgery

Objective To summarize the diagnostic and therapeutic experiences for multiple insulinoma. Methods Clinical data of 34 cKsefl of multiple insulinoma treated in Peking Union Medical College Hospital between 1984 and 2007 were analyzed retrospectively. Results Multiple insulinoma was identified in these 34 cases for 37 instances.Malignant insulinoma was found in 2 cases.Three cases suffered from postoperative recurrent multipie tumors.35.3% cases belonged to MEN1;13.5% cases were of insulinoma combined with islet hyperplasia;43.2% cases had 3 or more than 3 insulinomas;Fifteen cases (40.5%)had had a misdiagnosis.45.2%tumors were smaller than 1 cm in diameter:88.9%multiple insulinonla located at the body and tail of the pancreas.Enucleation of multiple tumors was performed for 48.7 percent of cases. Conclusions Most multiple insulinomas were small,it was difficult for preoperative examination to locate all the tumors therefore.Being on the alert against multiple insulinoma and such measures as careful exploration,intraoperative blood glucose determination.fine needle aspiration biopsy,frozen sections helps to avoid missing multiple imuhnoma.

Objective To analyze the effect of quality of life (QOL) on the prognosis of long-term survivors with nasopharyngeal carcinoma (NPC). Methods A total of 192 NPC patients treated between 1999 and 2000 and with tumor-free survival before July 2003 were enrolled in this study. All patients received QOL measurement between July and August in 2003. Measurement scales included Chinese SF-36 questionnaire and a checklist consisting of fourteen items about self-rating symptoms. The median follow-up time was 7.9S years (range 2.67-9.55 years). The effects of QOL, social demographic and clinical factors on prognosis were analyzed. Results Univariate analysis showed that QOL affected the tumor-free survival and overall survival. Multivariate analysis showed that hypomnesia was an independent prognostic factor of tumor-free survival, while trismus, headache and age were independent prognostic factors of overall survival. The younger and the better QOL had better prognosis. The other sociodemographic and clinical factors had no prognostic value. Conclusion QOL is an important factor affecting the prognosis of long-term survivors with NPC, and it should be routinely evaluated during the follow-up.

OBJECTIVETo investigate the effects of living high-training low (HiLo) on innate immunity in blood of elite swimmers.

METHODSSix female swimmers undertook HiLo for two weeks, erythrocyte adhesion function and counts of leukocyte were tested in different time of training period.

RESULTSRed blood cell C3b receptor ring rate (RBC-C3bRR) decreased and red blood cell immune complex matter ring rate (RBC-ICR) increased significantly (P < 0.05), the two markers returned to base line 1 week after training. Counts of leukocyte and granulocyte decreased significantly (P < 0.05), and they recovered 1 week after training; Counts of lymphocyte and monocyte decreased without significance during training and did not recovered after training.

CONCLUSIONImmunity of erythrocyte and granulocyte decreased quickly, but lymphocyte and monocyte recovered slowly, swimmers were adaptive to the training.

Adolescent ; Altitude ; Athletes ; Cell Adhesion ; Erythrocytes ; cytology ; immunology ; Female ; Humans ; Leukocyte Count ; Physical Education and Training ; Swimming

OBJECTIVEAccording to the information obtained from the revision of total hip arthroplasty, the situations of the artificial femoral stem under physiological stress were analyzed preliminarily. In order to accumulate clinical experience, the discussions about how to enlongate the life of artifical joints were performed.

METHODSFifty-three patients required revision operations were selected, including 28 males and 25 females,with an average age of 74.66 years old (61 to 84 years old). The average life of artificial joints was 18.24 years (3 to 27 years). The initial weightbearing was started 11 days (5 to 16 days) after the first operation. The main reasons for the revision were the spontaneous loosening and trauma. Based on imaging and surgical findings, as well as the histological pathology, the situations of the stems in human bodies were determined.

RESULTSFemoral prosthesis would sink under physiological stress. The design of femoral stems, motion of patients', and bone growth determined the secondary stability. Straight stems were helpful for physiological subsidence of prosthesis, achieving the stability with close bone-implant contact by bone growth,which allowed the patient to do early landing exercise. The collared prosthesis and prosthesis combined with internal fixation limited the subsidence of femoral stems. Their stability depends on the time of initial placement and the bone growth for supporting. Delaying the inital weightbearing was suggested for patients with these protheses.

CONCLUSIONAccording to the actual situation of the patients, the appropriate chosen of femoral stems and time to perform the weightbearing can extend the life of the femoral prosthesis.

Aged ; Aged, 80 and over ; Arthroplasty, Replacement, Hip ; adverse effects ; methods ; Female ; Hip Prosthesis ; Humans ; Male ; Middle Aged ; Prosthesis Design