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.

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 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.

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 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 To test intraoperative radiotherapy with mobile photon beam using the INTRABEAM system ( Germany) , and to analyze the dosimetric characteristics of low?energy photon beam using X?ray source and spherical applicators and explore its potential limitations in clinical application. Methods A special water phantom, a parallel?plate ionization chamber, and an electrometer were used to measure the depth dose rates and isotropy of dose distribution in x/y plane of X?ray source and different spherical applicators in the INTRABEAM system. Those data were then compared with the system data. Results For the X?ray source, the deviation of observed depth dose rate and isotropy in the x/y plane from the system data were-2.16%± 1. 36% and-1.9%~ 2. 1%, respectively. For applicators with different diameters, the deviation of observed depth dose rate, transfer coefficient, and isotropy in x/y plane from the system data were-10.0%~2. 3%,-8.9%~4. 2%, and-1.6%~2. 6%, respectively. Surface dose rate and dose gradient became larger with the decrease in the diameter of the spherical applicator. The measurement of depth dose rate and isotropy of X?ray source and spherical applicators showed good repeatability. The influencing factors for measurement accuracy included the positioning error of ionization chamber, energy response, noise current, and correction factor f ’ ( R ) . Conclusions This study reveals the dosimetric characteristics of the INTRABEAM system, verifies the accuracy of the system data, and obtains the data for clinical application and routine quality assurance. However, large dose gradient and small therapeutic range may limit its wide clinical application.

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.

Objective To highlight the characteristics of pulmonary sequestration (PS) with combination of practical experience and review of literature. Methods One patient with PS confirmed by biopsy was described and the relevant literatures of 279 cases were reviewed. Results PS can be divided into two types: intralobar type and extralobar type. The percentage of intralobar type is about 78.5%, intralobar type is 13.3%, other unreported is 8.2%. Clinically, PS was often combined by repeated pulmonary infection. The mis-diagnose rate is 72.8%. Etrograde arteriography or enhanced CT scan could find the abnormal artery, from which we can make correct diagnosis. The diagnose rate is 100%. Conclusion For patients with above clinical and X-ray symptoms, PS should be considered. Enhanced CT or retropgrade arteriography examination should be done as soon as possible. Timely diagnosis and surgery treatment are important for curing this kind of disease.