Genetic variability of group A and B human respiratory syncytial viruses isolated from 3 provinces in China

The genetic variability of HRSV in China was studied using nucleotide sequencing of the hypervariable C-terminal region of the G protein gene and phylogenetic analysis on 80 isolates obtained from three children's hospitals over a period of three epidemic seasons, 1990/1991, 2000/2001, and 2003/2004. The results showed that 76/80 of these isolates belonged to group A and 4/80 belonged to group B. Phylogenetic analysis revealed that most of the group A isolates were genotype GA2 (74/76 isolates), and the other two isolates were GA3 and GA5. All group B isolates clustered into genotype GB3. There was substantial variation among the GA2 isolates, with nucleotide sequence and amino acid homologies ranging from 88.1-100% and 78.4-100%, respectively, in the hypervariable C-terminal region of the G protein gene. One group B virus, HRSV/Beijing/B/04/11, contained a 60-nucleotide duplication in the C-terminal region of the G protein, which was similar to what has been reported previously for isolates in several countries. This is the first report on the genetic diversity of human respiratory syncytial virus isolated during epidemic periods from children in China. These data provided a preliminary evaluation of patterns of circulation and the genetic diversity of isolates associated with HRSV epidemics within China.

A novel T-77C polymorphism in DNA repair gene XRCC1 contributes to diminished promoter activity and increased risk of non-small cell lung cancer

X-ray repair cross-complementing 1 (XRCC1) plays a key role in DNA base excision repair and cells lacking its activity are hypersensitive to DNA damage. Recently, we reported a SNP (rs3213245, -77T>C) in the XRCC1 gene 5' untranslated region (UTR) was significantly associated with the risk of developing esophageal squamous-cell carcinoma. Computer analysis predicted that this SNP was in the core of Sp1-binding motif, which suggested its functional significance. Gel shift and super shift assays confirmed that -77T>C polymorphic site in the XRCC1 promoter was within the Sp1-binding motif and the T>C substitution greatly enhanced the binding affinity of Sp1 to this region. Luciferase assays indicated that the Sp1-high-affinity C-allelic XRCC1 promoter was associated with a reduced transcriptional activity. The association between -77T>C and three other amino-acid substitution-causing polymorphisms in XRCC1 and risk of lung cancer was examined in 1024 patients and 1118 controls and the results showed that only the -77T>C polymorphism was significantly associated with an increased risk of developing lung cancer. Multivariate logistic regression analysis found that an increased risk of lung cancer was associated with the variant XRCC1 -77 genotypes (TC and CC) compared with the TT genotype (OR=1.46, 95% CI=1.18-1.82; P=0.001) and the increased risk was more pronounced in smokers (OR=1.63, 95% CI=1.20-2.21) than in non-smokers (OR=1.28, 95% CI=0.94-1.76). Taken together, these results showed that the functional SNP -77T>C in XRCC1 5'UTR was associated with cancer development owing to the decreased transcriptional activity of C-allele-containing promoter with higher affinity to Sp1 binding.

Susceptibility of nonpromoter CpG islands to de novo methylation in normal and neoplastic cells

BACKGROUND

Many cancers display alterations in methylation patterns of CpG islands--stretches of DNA rich in CpG dinucleotides often associated with gene promoters that are involved in initiation of gene transcription. This methylation may perturb expression of genes critical to the regulation of cell proliferation. Aberrant methylation is not limited to a few genes or to promoter regions but has been found on a genome-wide scale in a variety of neoplasias, including colorectal cancer and acute myelogenous leukemia. Our goal was to characterize, in a quantitative manner, the profiles of abnormally methylated genes that may be specific for different cancers.

METHODS

Using a quantitative assay, methylation-sensitive single nucleotide primer extension (MS-SNuPE), we have analyzed the methylation levels of promoter and exonic (coding region) CpG islands of two cyclin-dependent kinase inhibitors [p15(INK4B) and p16(INK4A)] and the PAX6 gene, which encodes a transcriptional factor involved in neuronal proliferation, in DNA samples taken from patients with chronic myelogenous leukemia, acute myelogenous leukemia, myelodysplastic syndrome, and colorectal cancer.

RESULTS

De novo methylation of all three exonic loci in tumors--relative to baseline levels found in nontumor tissue or blood--was observed in hematologic neoplasias and in solid tumors as well as in normal colonic tissue. However, methylation of promoter regions was more limited. Moreover, two different patterns of promoter methylation distinguished the leukemias from colorectal cancer: p15 promoter hypermethylation was found only in the leukemias, and p16 promoter hypermethylation occurred only in colon tumors. However, we did not address this issue prospectively; therefore, such an observation is only hypothesis generating.

CONCLUSIONS

The methylation patterns that we observed suggest that exonic CpG islands are more susceptible to de novo methylation than promoter islands and that methylation may be seeded in exonic regions, from which it can spread to other islands, including promoter regions. Subsequent selection of cells with a growth advantage conferred by spread of methylation into and inactivation of a particular promoter might then contribute to the genesis of a specific type of cancer.

Diagnosis and treatment of spinal fractures combined with paraplegia and diaphragm injury

OBJECTIVE

To study the mechanism and treatment principle of spinal fractures combined with paraplegia and diaphragm injury.

METHODS

A total of 16 patients (14 males and 2 females, aged from 18 to 50 years) with spinal fractures combined with paraplegia and diaphragm injury, receiving emergency treatment and admitted to our hospital in the past 20 years, were retrospectively analyzed in this study.

RESULTS

The injuries were caused by direct or indirect violence. Six cases were of fractures of cervical spine combined with paraplegia and diaphragm injury, 2 of fractures of thoracic vertebra combined with paraplegia and diaphragm injury, and 8 of thoracolumbar fractures combined with paraplegia and diaphragm injury. Six cases received non-operative treatment, but died finally. Ten cases received spine surgical treatment, of which 4 died and 6 were improved. The total mortality rate was 62.5%.

CONCLUSIONS

Spinal fractures combined with paraplegia and diaphragm injury are one of the most severe traumas in departments of orthopaedics. Paraplegia can be found easily, but diaphragm injury is often neglected and missed. When a patient suffers from both of them, he is in danger of death. What measures should be taken to rescue the patient's life depends on the severity of the wounds.

[The study on subclinical Epstein-Barr virus infection of heroin addicts]

OBJECTIVE

To study the subclinical EBV infection and related factors among heroin addicts.

METHODS

Three hundred and twelve heroin addicts were tested for serum EBV-VCA-IgA antibody by immunoenzyme technique population, four hundred and twenty one serum specimens from general were selected as control.

RESULTS

Ninty nine heroin addicts (31.51%) were found to be EBV positive. Three people from control group (0.7%) were found to be EBV positive. EBV prevalence rates were significantly different among heroin addict groups according to a group (P = 0.05), duration of addiction. However the dose and sex difference of heroin addicts was not associated with EBV infection rate.

CONCLUSION

The high infection rate of EBV in heroin addicts might be connected with different kinds of factors, hence worthy of supervising the subclinical EBV infection of heroin addicts.

Global and gene-specific epigenetic patterns in human bladder cancer genomes are relatively stable in vivo and in vitro over time

We used a methylation-sensitive arbitrarily primed PCR technique to analyze, in a nonselective manner, methylation alterations at GC-rich regions of the genome in metachronous tumors and their derived cell lines from two patients with transitional cell carcinoma of the bladder. The methylation status of the majority of evaluable sequences (83%) remained unchanged in the tumors from both patients relative to a panel of normal urothelium samples obtained from individuals free of bladder disease, in which we measured <1% interindividual variation. The 17% of methylation alterations represents sequences altered in either a cancer-specific (3%), tumor-specific (1%), or patient-specific (13%) manner. The proportion of the altered sequences analyzed that were CpG islands corresponds to approximately 7000 CpG islands altered in the genome. Surprisingly, few additional changes in methylation patterns were observed in cell lines derived from the tumors; however, all of the cell lines showed altered methylation in a common set of 3% of evaluable sequences. Three genes known to be aberrantly methylated in bladder cancer (p16, p15, and PAX6) were studied in detail by methylation-sensitive single nucleotide primer extension and showed increased methylation in culture at preexisting methylated sites for all of the exons but no de novo methylation in culture for the promoters in any cell line. Therefore, our investigation provides the first serial as well as parallel quantitation of the global epigenetic stability in two independent bladder cancer genomes over the course of progression and in culture. In addition, our investigation also provides the first direct comparison of the epigenetic and genetic patterns on the global scale, showing the epigenetic pattern to be relatively stable in vivo and in vitro over time within an individual.

[The roles of vascular endothellial growth factor and endothelin-1 on pulmonary vascular remodelling in rats with hypoxia-induced pulmonary hypertension]

OBJECTIVE

To investigate the roles of the vascular endothelial growth factor(VEGF) and endothelin-1(ET-1) in pulmonary vascular remodelling in rats with hypoxia-induced pulmonary hypertension(HPH) and the effect of pinacidil on VEGF and ET-1 in rats with HPH.

METHOD

46 male Wister rats were divided into three groups i.e. control group, hypoxic group and treated group (hypoxic rats treated with pinacidil for 4 weeks). Rat models with chronic HPH were established by chronic hypobaric hypoxia [(10.0 +/- 0.5)% O2, 4 weeks]. The levels of VEGF and ET-1 in serum and the mean pulmonary arterial pressure (mPAP) and the weight ratio of right ventricle (RV)/left ventricle and septum (LV + S) [RV/(LV + S)] were measured and the small pulmonary arterial morphologic changes were observed with morphometric analysis under microscopes in the three groups.

RESULTS

(1) The levels of VEGF[(118.73 +/- 55.40) ng/L] and ET-1[(221.2 +/- 56.2) ng/L] in serum, mPAP [(28.4 +/- 2.8) mm Hg, 1 mm Hg = 0.133 kPa] and RV/(LV + S) (0.296 +/- 0.033) were significantly higher in the hypoxic group than those in the control group (P < 0.01). Morphometry showed that the external diameter of the small pulmonary arteries became smaller and the ratio of vascular wall thickness to external diameter (MT%) (25.70 +/- 2.58)% and ratio of vascular wall area to total area (MA%) (75.300 +/- 5.600)% significantly increased in the hypoxic group. (2) The levels of VEGF[(78.20 +/- 16.45) ng/L] and ET-1[(181.6 +/- 30.5) ng/L] in serum, mPAP[(23.3 +/- 2.6) mm Hg], RV/(LV + S) (0.266 +/- 0.037), MT%(22.10 +/- 2.51)% and MA% (66.900 +/- 0.061)% significantly decreased in the treated group.

CONCLUSION

VEGF and ET-1 play important roles in the development of HPH and pulmonary vascular remodelling. Pinacidil may partly inhibit the development of HPH and pulmonary vascular remodelling by decreasing VEGF and ET-1.

The endothelin receptor B (EDNRB) promoter displays heterogeneous, site specific methylation patterns in normal and tumor cells

The 5' region for the endothelin receptor B (EDNRB) gene is a complex CpG island giving rise to four individual transcripts initiating within the island. Here, for the first time, we analyze the relationship between methylation and gene expression in a CpG island located in the 5' region of a gene with multiple transcription start sites. The CpG island was unmethylated in normal prostate and bladder tissue, whereas it became methylated in apparently normal colonic epithelium. Tumors derived from these tissues were frequently hypermethylated relative to the respective normal tissues. Analysis of 11 individual CpG sites located throughout the CpG island showed that specific sites with high methylation levels in several tumors were also methylated in normal tissues, suggesting that they might serve as foci for further de novo methylation. This region also had high levels of methylation in several cancer cell lines, and we found that a low methylation level in a small region within the 5' region correlated with expression of the 5'-most transcript. Interestingly, almost complete methylation 200-1000 bp downstream of the transcriptional start site did not block expression of this transcript. Finally, we show that treatment with 5-aza-2'-deoxycytidine can induce transcriptional activation of the four EDNRB transcripts. Our results show the existence of differential, tissue-dependent methylation at the EDNRB 5' region, suggest the existence of a spreading mechanism for de novo methylation, starting from methylation hotspots, and show that hypermethylation immediately 3' to a transcriptional start site does not prevent initiation.

[Controlling effect of parasitoids on population of vegetable leaf miner Liriomyza sativae Blanchard]

The controlling effect of parasitoids on vegetable leaf miner, Liriomyza sativae Blanchard, was evaluated by using acting factor life tables and exclusion inex of population control(EPIC). The results showed that Chrysocharis pentheus, Neuchrysocharis formosa, Chrysonotomyia okazakii, Hemiptarsenus varicornis, Chrysocharis sp., Opius dimidiatus and Opius dissitus played an important role in controlling the population of vegetable leaf miner. The EIPCs of parasitoids were 1.23, 2.73, 5.98, 5.92 and 5.71, respectively for the five generations of L. sativae on kidney bean planted in spring, from the 1st to the 5th generation and, for the 2nd generation in particular, they were 2.73, 2.87, 2.24 and 1.89, respectively on kidney bean, cowpea, luffa and cucumber, indicating that if the parasitoids were excluded, the population of the next generation of L. sativae would increase by times accordingly. The EIPC of parasitoids for the 3rd instar larvae was usually the largest among different instar larvae and pupae, and the EIPCs for the 3rd to 5th generation of L. sativae on spring kidney bean were higher than those for the 1st and the 2nd. The EIPCs of parasitoids for L. sativae on kidney bean and cowpea were larger than those on luffa and cucumber.

Synchronization of hyperchaotic harmonics in time-delay systems and its application to secure communication

We present a predictor-feedback method for synchronizing chaotic systems in this paper. By using this method, two structurally equivalent or nonequivalent systems can be synchronized very effectively and quickly. Moreover, the feedback perturbation can be switched on even if trajectories of the two systems are far from each other. Therefore, this method is applicable to real-world experimental systems, especially to some fast experimental systems. The validity of this method is demonstrated by synchronizing hyperchaotic harmonics in a time-delay system. As an application, we introduce how messages can be encoded, transmitted, and decoded using this technique. We suggest taking use of the multistability of time-delay systems to improve the performance of the secure communication.

[Laboratory study on protective and therapeutic effects of pinacidil on pulmonary vascular remodeling in rats with hypoxia-induced pulmonary hypertension]

OBJECTIVE

To investigate the protective and therapeutic effects of pinacidil on hypoxia-induced pulmonary hypertension(HPH) and pulmonary vascular remodeling.

METHODS

46 male Wister rats were divided into control group, hypoxic group and treated group (hypoxic rat treated with pinacidil for 4 weeks). Rat models with chronic HPH were established by chronic hypobaric hypoxia [(10 +/- 0.5)% O2, 4 weeks)]. The mean pulmonary arterial pressure (mPAP) and right ventricle/left ventricle and septum [RV/(LV + S)] were measured and the small pulmonary arterial morphologic changes were observed with morphmetric analysis under microscopes in three groups.

RESULTS

(1) The level of mPAP(28.4 +/- 2.8) mm Hg and RV/(LV + S) (0.30 +/- 0.03) were significantly higher in the hypoxic group than (16.2 +/- 1.8) mm Hg and (0.22 +/- 0.03) in control group respectively (P < 0.01). Morphometry investigation showed that the external diameter became smaller and that ratio of vascular wall thickness to external diameter (MT%) (25.7 +/- 2.6)% and ratio of vascular wall area to total area (MA%) (75.3 +/- 5.6)% significantly increased in the hypoxic group. (2) The mPAP(23.3 +/- 2.6) mm Hg, RV/(LV + S) (0.27 +/- 0.04) and pulmonary vascular pathologic changes MT%(22.1 +/- 2.5)% and MA% (67.0 +/- 6.1)% significantly decreased in the treated group, indicating that pinacidil inhibited HPH and hypoxia-induced thickening and muscularization of small pulmonary arteria.

CONCLUSION

Pinacidil may partly prevent the development of HPH and pulmonary vascular remodeling.

[Lifetable of cotton bollworm under different control condition]

The lifetables of 3rd and 4th generation of cotton bollworm Helicoverpa armigera Hubner were established by action factors under four different control conditions. The results showed that under natural control, the egg parasitic rates of 3rd and 4th cotton bollworm were 4.39% and 1.19%, the predatory rates were 21.11% and 15.80%, and the larvae parasitic rates were 19.34% and 16.20% respectively. The indexes of population trend were only 0.0032 and 0.0014 respectively, after using selective pesticides IKI and Bt to control cotton bollworm. Though the index of population trend decreased to 48.66% and 61.67% after contantly praying chemical pesticides, the number of predators also decreased to 23.48% and 41.26% respectively. Transgenic Bt cotton could inhibit the population increase of cotton bollworm, but had no effect on predators. The parasitic rates of 3rd and 4th cotton bollworm on Transgenic Bt cotton were 51.14% and 0% respectively, as compared to control.

Regulation of mouse sterol regulatory element-binding protein-1c gene (SREBP-1c) by oxysterol receptors, LXRalpha and LXRbeta

The liver X receptors (LXRs) are members of the nuclear hormone receptor superfamily that are bound and activated by oxysterols. These receptors serve as sterol sensors to regulate the transcription of gene products that control intracellular cholesterol homeostasis through catabolism and transport. In this report, we describe a novel LXR target, the sterol regulatory element-binding protein-1c gene (SREBP-1c), which encodes a membrane-bound transcription factor of the basic helix-loop-helix-leucine zipper family. SREBP-1c expression was markedly increased in mouse tissues in an LXR-dependent manner by dietary cholesterol and synthetic agonists for both LXR and its heterodimer partner, the retinoid X receptor (RXR). Expression of the related gene products, SREBP-1a and SREBP-2, were not increased. Analysis of the mouse SREBP-1c gene promoter revealed an RXR/LXR DNA-binding site that is essential for this regulation. The transcriptional increase in SREBP-1c mRNA by RXR/LXR was accompanied by a similar increase in the level of the nuclear, active form of the SREBP-1c protein and an increase in fatty acid synthesis. Because this active form of SREBP-1c controls the transcription of genes involved in fatty acid biosynthesis, our results reveal a unique regulatory interplay between cholesterol and fatty acid metabolism.

Molecular epidemiologic study of Mycoplasma genitalium infection in high risk populations of sexually transmitted diseases in China

OBJECTIVE

To detect Mycoplasma genitalium (Mg) infection in high risk populations of sexually transmitted diseases (STDs) from several cities in China and to clarify the possible role of Mg in the pathogenesis of non-gonococcal urethritis.

METHODS

Polymerase chain reaction (PCR) based on 2 pairs of primers, one for Mg-Pa (adhesion protein) and the other for 16S-rRNA (Mycoplasma genera) was used to detect Mg infection. Urogenital specimens of different high risk populations and urethritis patients, were collected from the Guangdong, Kunming, Shanghai, Nanjing, and Changzhou areas.

RESULTS

The positive detection rate of Mg-DNA in high risk populations of STDs was significantly higher than that of the control group (chi 2 = 7.82, P < 0.01). The positive detection rates in Guangdong STD clinics and promiscuous persons from Kunming were higher than those from the Shanghai, Nanjing, and Changzhou areas (chi 2 = 8.54, P < 0.01 and chi 2 = 5.89, P < 0.05). Mg DNA could be detected in those patients without other relevant pathogens. Some patients were simultaneously infected with Mg and other microbes, such as Chlamydia trachomatis and/or Ureaplasma urelyticum. The positive Mg-DNA detection rate in patients with urethritis symptoms was higher than in patients without the symptoms (chi 2 = 11.68, P < 0.01).

CONCLUSION

Mg infection exists in high risk populations of STDs in China, and the Mg infection rate is different among different high risk groups.

[Arthropod diversity in leafy vegetable field and sampling technology]

Two sampling units (plant and quadrat) and two sampling methods (random and fixed) were adopted to compare the variation degree of the diversity of arthropod communities in different chinese cabbage fields. The results show that a lower variation degree was found when the random sampling method was adopted with quadrat (0.11 m2) as sampling unit at seedling stage and with plant as sampling unit from growing to mature stage. The community diversity was relatively steady, when the critical number of samples was more than 12 quatrats (0.11 m2) at seedling stage, 30 plants in growing period, and 20 plants at mature stage. The optimum sampling unit, sampling method and sampling number of arthropod diversity in leafy vegetable field were also determined.

The gene for a novel transmembrane protein containing epidermal growth factor and follistatin domains is frequently hypermethylated in human tumor cells

A DNA fragment frequently hypermethylated in tumor cells was isolated using a novel screening strategy termed methylation-sensitive arbitrarily primed PCR. The isolated sequence corresponded to a CpG island at the 5' end of a previously unknown gene, TPEF (transmembrane protein containing epidermal growth factor and follistatin domains). Expression of TPEF was observed using Northern master blot analysis of a variety of normal tissues including colon, bladder, and prostate tissue. TPEF maps to human chromosome 2q33, where frequent loss of heterozygosity is seen in various human tumors, and TPEF was not expressed in most human colon and various other tumor cell lines examined by reverse transcription-PCR. Nine of 11 tumor cell lines were highly methylated in the 5' region and the first exon of the gene that demonstrated features characteristic of a CpG island. However the other two cell lines, which expressed TPEF, were hypomethylated in the 5' end of the gene. The region was also hypermethylated in 11 of 16 primary bladder tumors and in 3 of 4 primary colon tumors when compared with adjacent normal tissue. Our results suggest that potential tumor suppressor genes can be isolated from human tumors by virtue of their altered methylation patterns.

[Effect of Sindbis XJ-160 virus structural proteins on BHK-21 cell]

OBJECTIVE

To study the effect of Sindbis XJ-160 virus structural proteins on BHK-21 cell.

METHODS

We constructed the expressing vector pcDNA3.1 ABC that contains the XJ-160 virus structural protein gene and then transfected it to BHK-21 cell.

RESULTS

The expressed products can be detected by RNA dot blot hybridization or immUnofluorescent assay. The cytopathic effect was observed in BHK-21 cells transfected with pcDNA3.1 ABC. There was also condensed chromatin found accumulated. BHK-21 cell death and marked cell cycle changes were observed.

CONCLUSIONS

These results indicate that cell apoptosis might be one of the mechanisms inducing cell death by XJ - 160 virus and its structural protein gene probably plays a role in this programmed cell death.

[Epizootic dynamics of Spodoptera litura nuclear polyhedrosi virus]

Through investigation of tracking infected Spodoptera litura larvae, the epizootic dynamics of S. litura nuclear polyhedrosis virus(SlNPV) in field was studied with different dosages of SlNPV. The results showed that in the range of virus dosages (3.1 x 10(5)-3.1 x 10(8) PIBs.ml-1), the initial infection syndrome was observed after 4 days of treatment, and peaked in 5-7 days. The larvae mortality occurred after 5-6 days of treatment, and peaked in 6-8 days. The prevalence peak of host was basically coincident to the incidence peak. The distribution of diseased incidence of hosts and disease death time could be quite simulated by time-dosage-mortality model(TDM). Hosmer-Lemoshow test showed that the predicted values well fitted with observed data, and t-test indicated the parameters of the model reached significant level(P < 0.0001). The distribution of diseased prevalence was simulated by Holliday model, the regression of function was significant by F-test, and the parameters of the model reached or approached significant level(p < 0.005). TDM model could be used to predict the daily incidence, prevalence, disease death rate of present generation population of host pest.

PAX6 methylation and ectopic expression in human tumor cells

The mechanisms underlying the de novo methylation of CpG islands in human cancer remain almost completely unknown. We used a methylation-sensitive arbitrarily primed polymerase chain reaction (Ms AP-PCR) technique to scan genomic DNA for differential methylation patterns and identified a 550 bp band that was hypermethylated in a majority of colon and bladder cancer cells. This band corresponded to a CpG-rich region in exon 5 of PAX6, which is a highly conserved transcription regulatory factor involved in embryogenesis. Interestingly, exon 5 was very frequently methylated in solid tumors compared with adjacent normal tissues, 17 out of 27 (63%) in bladder, and colon, but the promoter remained unmethylated in all these cases. This methylation was not effective in blocking transcription since ectopic expression of PAX6 was seen in several tumors and cell lines with extensive exon 5 methylation. De novo methylation of the promoter was only seen in tumor cell lines and was associated with gene silencing since treatment with 5-aza-2'-deoxycytidine restored expression to the cells and resulted in a less methylated promoter. Thus, ectopic expression and hypermethylation of exon 5 of PAX6 demonstrate that methylation within a transcribed region, as opposed to promoter methylation, does not block gene expression.