On a relaxation-labelling algorithm for quantitative assessment of tumour vasculature in tissue section images

Although tumour vasculature constitutes a biological factor playing a crucial role in the radiation response of tumours, the current procedures of assessment are semiquantitative, typically employing visual examination of stained histological material. Such techniques are also time consuming, and inefficient of extracting essential information on the vascular network. Image analysis has yet to contribute significantly in this direction, and most studies to date focus on blood vessel segmentation through empirical, user-selected thresholds. The present paper proposes an alternative segmentation approach, based on a probabilistic relaxation algorithm, applied in microscopic images of stained tissues. After image partitioning various information is obtained, such as vascular domains and geometrical characteristics of vessels.     

Microarray analysis on Phase II drug metabolizing enzymes expression in pregnant rats after treatment with pregnenolone-16alpha-carbonitrile or phenobarbital

We previously reported the expression profiles of 9 cytochrome P450 isozymes (CYPs) proteins and those of 40 CYPs genes in pregnant rat's liver, placenta and fetal liver after treatment with pregnenolone-16alpha-carbonitrile (PCN) or phenobarbital (PB). This study was carried out focusing on the gene expression profiles of Phase II drug metabolizing enzymes, Glutathione S-transferase isozymes (GSTs) and UDP-glycosyltransferase isozymes (UDPGTs). Fischer 344 (F344) pregnant rats were daily treated intraperitoneally with 50 mg/kg of PCN or 80 mg/kg of PB from 13 to 16 days of gestation (DG). They were sacrificed on 17 DG, and microarray analysis using Affymetrix Rat Expression Array 230 A was performed. Among 16 GSTs genes examined in this study, 7 genes were significantly induced in dam's liver and 3 genes in fetal liver, respectively, in the PCN-group, while 8 genes were significantly induced in dam's liver and 1 gene in fetal liver, respectively, in the PB-group. On the other hand, among 11 UDPGTs genes examined, 5 genes were significantly induced in dam's liver and 3 genes in fetal liver, respectively, in the PCN-group, while 5 genes were significantly induced in dam's liver and 1 gene in fetal liver, respectively, in the PB-group. There were no significant changes in the placenta of all groups. This is the first report of the gene expression profiles of Phase II drug metabolizing enzymes in pregnant rat and fetal livers and placenta after treatment with typical inducers of drug metabolizing enzymes.     

共聚焦激光扫描显微镜(MRC600)活体观测家兔大脑皮质内微循环的动物模型制作方法及其应用探讨

目的 :用共聚焦激光扫描显微镜活体观测家兔大脑皮质内微血管构筑及其微循环提供更近似于人类的动物模型。方法 :在开放颅窗的家兔动物模型上 ,荧光素标记血浆 ,罗丹明 6G标记WBC ,用共聚焦激光扫描显微镜活体观测正常状态下家兔大脑皮质内微循环 ,并经图像分析系统测量数据 ,用SAS软件包进行统计学分析。结果 :本研究探索用开放颅窗的家兔动物模型进行大脑皮质微循环的研究取得成功 ,作者认为采用开放颅窗的家兔动物模型使观察大脑皮质的深度达 2 5 0～ 30 0 μm ,对大脑皮质内微血管构筑及微循环进行活体观测 ,可进行连续断层扫描 ,或在同一层面进行连续定位扫描监测 ,所摄取图像经监视器及计算机摄入并存盘待分析 ,用图像分析系统进行观测血管口径 ,血流速度 ,血液流态 ,白细胞 ,红细胞运动等微循环指标 ,也可用标准Bio Radthruview软件三维重建 ,观察各种血管形态 ,研究大脑皮质微血管构筑。结论 :开放颅窗的家兔动物模型是更近似于人类的动物模型 ,适合用于脑血管疾病发病机理的研究     

Identification of N-(deoxyguanosin-8-yl)-4-azobiphenyl by (32)P-postlabeling analyses of DNA in human uroepithelial cells exposed to proximate metabolites of the environmental carcinogen 4-aminobiphenyl

DNA adducts formed in human uroepithelial cells (HUC) following exposure to N-hydroxy-4-aminobiphenyl (N-OH-ABP), the proximate metabolite of the human bladder carcinogen 4-aminobiphenyl (ABP), were analyzed by the (32)P-postlabeling method. Two adducts detected by (32)P-postlabeling were previously identified as the 3',5'-bisphospho derivatives of N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG-C8-ABP) and N-(deoxyadenosin-8-yl)-4-aminobiphenyl (dA-C8-ABP) (Frederickson S et al. [1992] Carcinogenesis 13: 955-961; Hatcher and Swaminathan [1995b] Carcinogenesis 16: 295-301). In contrast to the dG-C8-ABP adduct, which was 3'-dephosphorylated by nuclease P1, dA-C8-ABP was resistant to nuclease P1, thus providing an enrichment step before postlabeling. Autoradiography of the two-dimensional thin-layer chromatogram of the postlabeled products obtained following nuclease P1 digestion revealed several minor adducts, one of which has been identified in the present study. Postlabeling analyses following nuclease P1 digestion of the products obtained from the reaction of N-acetoxy-4-aminobiphenyl with deoxyguanosine-3'-monophosphate (dGp) demonstrated the presence of this minor adduct. The 3'-monophosphate derivative of the adduct was subsequently chromatographically purified and subjected to spectroscopic analyses. Based on proton NMR and mass spectroscopic analyses of the synthetic product, the chemical structure of the adduct has been identified as N-(deoxyguanosin-N(2)-yl)-4-azobiphenyl (dG-N==N-ABP). (32)P-Postlabeling analysis of the nuclease P1-enriched DNA hydrolysate of HUCs treated with N-OH-ABP or N-hydroxy-4-acetylaminobiphenyl (N-OH-AABP) showed the presence of the dG-N==N-ABP adduct. It was also detected in calf thymus DNA incubated with HUC cytosol and N-OH-ABP in the presence of acetyl-CoA, or incubated with HUC microsomes and N-OH-AABP. These results demonstrate that in the target cells for ABP carcinogenesis in vivo, N-OH-ABP and N-OH-AABP are bioactivated by acyltransferases to reactive arylnitrenium ions that covalently interact at the N2 position of deoxyguanosine in DNA.     

Molecular epidemiology of norovirus variants detected in children under five years of age in Hyderabad,India

PurposeNoroviruses are common viral agents in acute diarrhea in all age groups worldwide. Norovirus has been classified into 10 genogroups, GI to GX with over 48 genotypes among them the GII.4 genotype has evolved over time with a clear pattern of periodic variant replacement. Immunity is strain or genotype specific with little or no protection conferred across genogroups. The present study was aimed to determine the epidemiology, prevalent genotypes of norovirus in children below five years of age in the Hyderabad region, India.MethodsThe stool samples and clinical data were collected from 458 children below 5 years of age comprising of cases with acute gastroenteritis (n ?= ?366) and a control group (n ?= ?92) admitted to the pediatric ward. All the samples were tested for Norovirus by ELISA and RT-PCR. Sequencing was done for predominant strains.Results10.3% (n ?= ?38) of cases and 3.2% (n ?= ?3) of the control group were found to be Norovirus positive. Predominant genotypes were GII-82.5% followed by GI-12.5%.ConclusionSequencing and Phylogenetic analyses of 20 GII.4 strains was done. All of the isolates are clustered away from published the GII.4 variants thus suggesting the appearance of a new variant.     

Restriction endonuclease analysis of varicella-zoster vaccine virus and wild-type DNAs

The DNA from several clinical isolates of varicella-zoster virus (VZV) were compared with the DNA from the vaccine strain VZV using three restriction endonucleases: BamHI, BgII, and HpaI. When electrophoresed through an agarose gel, the vaccine DNA digestion pattern was significantly different from the digestion patterns of the wild-type DNAs. Variations in the digestion pattern of the separate clinical isolates were also observed.     

Expression of human immunodeficiency virus type 1gag gene using genetically engineered herpes simplex virus type 1 recombinants

Infectious herpes simplex virus type 1 (HSV-1) recombinants were constructed by inserting the cDNA sequence of the human immunodeficiency virus type 1 (HIV-1)gag gene (from nucleotide position 675 [SacI] to 3859 [Asp 718] of the cDNA sequences of HIV-1 strain BH-10) within the DNA sequences of theBamHI DNA fragment B of the genome of an apathogenic HSV-1 strain HFEM. This HSV-1 strain possesses a 4.1-kbp deletion within theBamHI DNA fragment B between 0.762 and 0.789 map units of the viral genome, which allows the insertion of at least 4 kbp of foreign genetic material into this particular region. The DNA sequences of the immediate early promoter (IE4) of HSV-1 that were inserted upstream from thegag gene were used as a promoter. The screening of 205 virus stocks derived from individual plaques revealed that 46 recombinant viruses harbor HIV-1gag-specific DNA sequences. However, it was found that only six of the recombinant viruses are able to express thegag gene product of HIV-1. This indicates that the ratio of the positive recombination events is about 2.9%.     

1519例胎儿心电图的临床价值和相关因素分析

目的对1519例胎儿全部实行常规胎儿心电图(FECG)监测工作,探讨胎儿心电图应用情况,并对异常FECG结合临床,进行临床原因分析.方法采用随机湘样方法,应用杭州产FECG-D型胎儿心电图分析仪进行监测.结果发现采用横导联方式进行监测检出率为53.5%:在孕22w进行监测检出率为45.8%;异常FECG检出率为7.64%.结论对1519例FECG的监测发现采用横导联方式并在孕22w～26w期间进行监测检出率最高、波形效果好.并对监测发现的导致FECG异常改变的临床原因与胎儿宫内窘迫的关系进行浅要分析.