The major goal of microbial ecology is to study the structure and function of complex micro-bial communities. New molecular biological techniques have been successfully applied to analyze mi-crobial community structure. However they do not provide information on the physiologic properties of the detected microorganisms. A new tool for structure-function analyses in microbial ecology, micro-autoradiography combined with fluorescence in situ hybridization (MAR-FISH) can be used to simul-taneously examine the phylogenetic identity and the specific activity of microorganisms within a com-plex microbial community at a single-cell level. This article reviews the principle, experimental steps of MAR-FISH technique. The application of this technique in study of the environmental microbial com-munity and function is also summarized.

Objective To analyze the mutations in nucleotide sequences of transfusion transmitted virus(TTV) in neonatal infection.Methods Neonatal serum TTV-DNA was detected by a nested PCR technique.Fifteen Chinese neonates with positive TTV-DNA were diagnosed as TTV infection.ORF1 sequences of TTV-DNA from these neonates were determined.Results Homology of Chinese TTV(C01-C15) and Japanese TTV(N22)isolated ranged from 87.1%-97.7% at nucleotide level,but there were point mutations in Chinese TTV,such as GG→TT in locus 112 and 113,TTATC→CCTAT in locus 236-240.Conclusions Chinese and Japanese TTV isolated had the same genotype.Some gene mutations may increase the TTV pathogen,and result in neonatal hepatitis syndrome or hyperbilirubinemia.

Inheirted metabolic disodrers(IMD)involves in multiple substance dysbolism,which usually results in irreversible neurological lesions because of various categories and complicated clinical manifestations.In resent years,IMD became one of the hot spots in medical domain around the world,original diagnostic technique and management progressed unceasingly.This paper provides an overview of the traditio-nal detection and treatment about IMD,and reviews the new techniques such as gene analysis,gene chip,organ transplantation and enzyme replacement therapy at the same time.

Objective To compare the difference of early trauma experience between early-onset and late-onset obsessive-compulsive disorder(OCD),and the kinds of early trauma in the cause of OCD. Methods Three hundred and twenty-six patients with obsessive-compulsive disorder and 480 healthy con-trols were enrolled. Early Trauma Inventory-Short Form ( ETI-SF) was applied to assess the early trauma ex-perience,compare the difference of early trauma experience between early-onset ( n=138) and late-onset ( n=188) OCD,and the kinds of early trauma in the cause of OCD. Results There were significant differences in the early trauma experience between obsessive-compulsive disorder group and control group((3.90±3.61) vs (1.88±2.61), P<0.01).Scores of physical((1.12±1.38) vs (0.71±1.23), P=0.001),emotional((1.58± 1.71) vs (0.42±1.01), P<0.01),and sexual abuse((0.27±0.59) vs (0.09±0.36), P=0.001),and a gener-al traumatic experience((0.94±1.17) vs (0.66±1.09), P<0.01) were significant difference between patients and controls. Except sexual abuse((0.30±0.66) vs (0.24±0.67), P=0.42),there were significant differ-ences in the early trauma between early-onset and late-onset OCD((5.12±3.58) vs (3.01±3.38), P<0.01), especially emotional abuse((2.18±1.76) vs (1.12±1.53), P<0.01).247(75.8%) OCD patients and 79(57. 9%) healthy controls experienced early trauma(χ2=21.48, P<0.01). Experiencing one kind of early trau-ma,the prevalence of OCD was 39.1%,two kind was 61.0%,three kind of early trauma was 65.8%,and ex-periencing four or more kind of early trauma,the prevalence of OCD was up to 84.4%. Conclusion OCD patients have much more early trauma,especially early-onset OCD. Experiencing more kind of early trauma, and the prevalence of OCD higher may associated with the development of obsessive-compulsive disorder. It is important to consider the role of childhood trauma in the prevention and treatment of OCD.

Objective To explore the application value of two-dimensional echocardiography with spatio-temporal im-age correlation (STIC) in fetal congenital heart disease (CHD) prenatal ultrasonography. Methods 11 036 hearts of fetus were inspected by severalviews order scanning method and for STIC volume database acquisition and off-line a-nalysis congenital heart disease fetus for autopsy after induced labor or contrast the follow-up results after birth. Re-sults 97 cases with spatio-temp-oral image correlation in 176 cases congenital heart and great vessels exception (dysrhythmias not including) with simple two-dimensional echocardiography,92 cases were accordant (one case with incorporative intracardiac malformation missed diagnosis);in screened congenital heart disease fetus,STIC (n=79) and routine ultrasonography (n=87) took (7.76±2.42) min and (9.68±2.13) min per case,respectively;in dif-ferent gestational weeks,the quality of the images derived from volume datasets were comparable to that directly ob-tained from 2D echocardiography. Conclusion STIC technology can be used as effective supplementary means of 2D echocardiography, and the combination can further improve the prenatal diagnosis of fetal congenital heart disease.

Objective To evaluate the effects of different doses of propofol or isoflurane on the cochlear blood flow (CBF) in guinea pigs.Methods Fifty-four adult male guinea pigs,aged 3 months,weighing 400-500 g,were randomly divided into 6 groups (n =9 each).In P1,P2 and P3 groups,propofol was infused for 115 min at 10,20 and 40 mg· kg-1 · h-1,respectively,after a loading dose of 5 mg/kg was injected over 5 min.In S1,S2 and S3 groups,isoflurane was inhaled for 120 min with end-tidal concentrations of 1％,2％ and 3 ％,respectively.Mean arterial pressure and CBF were recorded before administration (baseline,T1) and during the period of drug administration.Distortion product otoacoustic emission (DPOAE) was measured at T1,at the end of administration (T2) and 1 h after administration (T3).Five animals in each group were sacrificed and organs of Corti were harvested for observation of morphology of out hair cells by scanning electron microscopy.Results Propofol decreased MAP and increased CBF and DPOAE amplitude in a dose-dependent manner.Isoflurane decreased MAP and CBF in a dose-dependent manner.1％ isoflurane increased DPOAE amplitude,however,2％ and 3％ isoflurane decreased it and caused damage to out hair cells.Conclusion Propofol induces an increase in CBF in guinea pigs,while high concentration of isoflurane induces a decrease in CBF.Isoflurane inhibits CBF autoregulation,which makes CBF more sensitive to perfusion pressure,thus causing damage to hearing function.This is the reason why high concentration of isoflurane induces a decrease in CBF.

Objective:This work aims to explore the long-term efficacy and complications of late-course accelerated hyperfrac-tionation (LCAHF) for treating nasopharyngeal carcinoma. Methods:A total of 58 patients who consulted from December 2005 to May 2008 and histologically proven nasopharyngeal carcinoma at initial diagnosis were randomized into an LCAHF group (experimental group) and a conventional fractionation (CF) group (control group). The treatment dose for both groups was 2 Gy per fraction once dai-ly, 5 days a week. After the 40 Gy to 50 Gy dose, the dosage in the LCAHF group was increased to two daily doses at 1.5 Gy per frac-tion 6 h apart, 5 days a week. The total dose in this group was 73 Gy to 76 Gy, the total dose in the CF group was 70 Gy to 76 Gy, with the total course of the treatment shortened by 0.5 weeks to 1.5 weeks in the former group. Results:The 5-year control rates of the naso-pharyngeal cancers was 86% in the LCAHF group and 59% in the CF group (P=0.021), with statistically significant differences be-tween the two groups. The late complications slightly increased in the LCAHF group than in the CF group, but the differences were not statistically significant. Conclusion:LCAHF treatment improves the local control of nasopharyngeal carcinoma without increasing the incidence of long-term complications.

The computerized imitating system constructed by the Second Affiliated Hospital of Guangzhou Medical University contains four blocks:administration of student infomation,administration of question bank,on-line tests and administration of score inquiry.It's designed to imitate typical pediatric cases,so that the medical students may put themselves into the practical clinical scenario and solve the challenges step by step in one-direction procedure.Teaching with computerized clinical scenario imitating patients can improve students' test resuhs and activate students' learning enthusiasm significantly.It not only helps to solve the contradiction between increasing number of medical students and clinical typical teaching case shortage but also improves the clinical thinking ability of the medical students.This system can also be used as a test bank for pediatric technical skills examination.

Objective To investigate the influence of ursolic acid on vascular endothelial growth factor ( VEGF) , cycloxygen-ase-2 (COX-2), and matrix metalloproteinases-2 (MMP-2) expressed in the mouse retinal ischemic model , and to explore the mecha-nisms of anti-angiogenesis.Methods Sixty 7-day clean-class C57BL/6J mice were divided randomly into 6 groups [ n =10 mice (20 eyes) per group]:blank control, model control (PBS), positive control (triamcinolone), and ursolic acid (UA) intervention (low-dose, medium-dose, and high-dose).Mice in the blank control group were raised in air , and mice in other groups in(75%±2%)O2 high-oxygen environment for 5 consecutive days .Mice in the model control group and breastfeeding mice were put back in air environ-ment (21%O2 ) on the 12th day after the new-born mice to induce the generation of retinal neovascularization .When models were suc-cessful, the drug treatments were applied immediately to the corresponding groups , with injection of 3μl of sterile PBS in model control group, 3 μl of 1.5, 3.00 and 6.0 μg UA in UA intervention group, and 3 μl of triamcinolone (1 ml∶40 mg) in positive control group, respectively.All mice were killed after overdose anesthesia on the 17th day.Their eyeballs were made into samples and retinal tissue pathological sections with H-E dying method.The positive expressions of VEGF , COX-2, and MMP-2 were detected with immu-nohistochemical method .The fresh retinal tissue homogenate was prepared to detect the protein expressions of VEGF , COX-2, and MMP-2 in retinal tissue with western blot method ,and mRNA expressions of VEGF , COX-2, and MMP-2 were detected with real-time fluorescent quantitative polymerase chain reaction ( RT-PCR) .Results According to protein and mRNA expressions of VEGF , COX-2,and MMP-2 in retinal tissue among six groups , protein expressions of VEGF , COX-2, and MMP-2 in model group were significantly higher than those in blank group ( P <0.05 ) .Each protein expression in the high UA intervention group was significantly lower than that in the model group ( P <0.05 ) .Each protein expression in the high UA intervention group was not significantly different from that in the positive group ( P >0.05 ) .Each protein expression in the high UA intervention group was significantly lower than that in the low UA intervention group( P <0.05).Conclusions UA inhibited expressions of VEGF, COX-2, and MMP-2 in retinal ischemia model .UA also played an inhibitory role in the formation of neovascularization , and this role was positively correlated with UA dose .

Objective To determine the effect of bacille Calmette-Guerin-polysaccharide nucleic acid (BCG/PSN)on 2,4-dinitrochlorobenzene(DNCB)-induced atopic dermatitis-like skin lesions in Nc/Nga mice.Methods Fifteen mice were randomly and equally classified into 3 groups,i.e.,control group receiving topical acetone on foot pad and abdomen and intraperitoneal injection of physiological saline,model group receiving topical 5% DNCB solution and intraperitoneal injection of physiological saline,treatment group receiving 5% DNCB solution and intraperitoneal iniection of BCG/PSN,and all drugs were used every other day for 7 weeks.Further more,0.1% DNCB was topically applied on the ear and neck of Nc/Nga mice once a week from week 2 to week 7.The effects of BCG/PSN were evaluated by ear thickness,skin histopathology and immunological parameters.Results Repeated application of DNCB caused the development of eczematous dermatitis in mice.Mice in model group chnieally manifested skin dryness,erythema,edema and erosion with histopathological changes including dermal and epidermal thickening,hyperkeratosis,and inflammatory infiltration.The serum levels of IL-4 and IrE in model group were significantly higher than those in control group[(174.72±12.64)μg/L vs (17.32±3.56)μg/L,(91.49±6.32)ng/L vs (83.95±6.63)ng/L,both P<0.05].Increased serum IL-12 and IFN-γ and decreased serum IgE were observed in treatment group compared with the model group[(122.10±4.64)ng/L vs (20.14±6.15)ng/L(73.89±2.39)ng/L vs (51.53±3.45)ng/L, (84.27±9.35)μg/L vs (174.72±12.64)μg/L, all P<0.05].Conclusion BCG/PSN might be beneficial for the treatment of atopie dermatitis-like skin lesions in Nc/Nga mice by enhancing the secretion of IL-12 and IFN-γ and suppressing the synthesis of IgE.