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1.
The genome of influenza A virus comprises 8 segments (segments 1–8) of single-stranded RNA (virion RNA: vRNA) with negative-polarity. All vRNAs share 13 and 12 terminal nucleotides in the 5′ and 3′ untranslated regions (UTRs), respectively, which are partially complementary and constitute panhandle and corkscrew structures. Here, it is shown, from the analysis of genomic sequences for 506 strains of influenza A virus, that the number of contiguous complementary nucleotides in the 5′ and 3′ UTRs varies from 4 to 7 among segments. Complementary nucleotides were segment specific and highly conserved in all segments except for segment 6, where in the phylogenetic analysis co-evolution was observed to have occurred between and within subtypes of neuraminidase (NA). Mutations in the terminal sequences sometimes appeared to have caused convergence between subtypes, involving changes in multiple nucleotide positions. These observations suggest that intra-segmental (homologous) recombinations may have taken place for transferring terminal sequences in segment 6.  相似文献   

2.
Bangladesh has been severely hit by highly pathogenic avian influenza H5N1 (HPAI-H5N1). However, little is known about the genetic diversity and the evolution of the circulating viruses in Bangladesh. In the present study, we analyzed the hemagglutinin gene of 30 Bangladeshi chicken isolates from 2007 through 2010. We analyzed the polybasic amino acid sequence motif of the cleavage site and amino acid substitution pattern. Phylogenetic history was reconstructed using neighbor-joining and Bayesian time-scaled methods. In addition, we used Mantel correlation tests to analyze the relation between genetic relatedness and spatial and temporal distances. Neighbor-joining phylogeography revealed that virus circulating in Bangladesh from 2007 through 2010 belonged to clade 2.2. The results suggest that clade 2.2 viruses are firmly entrenched and have probably become endemic in Bangladesh. We detected several amino acid substitutions, but they are not indicative of adaptation toward human infection. The Mantel correlation test confirmed significant correlation between genetic distances and temporal distances between the viruses. The Bayesian tree shows that isolates from waves 3 and 4 derived from a subgroup of isolates from the previous waves grouping with a high posterior probability (pp = 1.0). This indicates the possibility of formation of local subclades. One surprising finding of spatio-temporal analysis was that genetically identical virus caused independent outbreaks over a distance of more than 200 km and within 14 days of each other. This might indicate long distance dispersal through vectors such as migratory birds and vehicles, and challenges the effectiveness of movement restriction around 10 km radius of an outbreak. The study indicates possible endemicity of the clade 2.2 HPAI-H5N1 virus in Bangladesh. Furthermore, the formation of a subclade capable of transmission to humans cannot be ruled out. The findings of this study might provide valuable information for future surveillance, prevention and control programme.  相似文献   

3.
4.

Background:

Although it is known that sperm aneuploidy contributes to early pregnancy losses and congenital abnormalities, the causes are unknown and environmental contaminants are suspected.

Objectives:

Our goal was to evaluate associations between lifetime exposure to organochlorines, specifically dichlorodiphenyldicholorethylene (p,p´-DDE) and polychlorinated biphenyls (PCBs), and sperm aneuploidy in men from the general population of the Faroe Islands, a population with a known history of organochlorine exposures.

Methods:

Serum and semen samples from men (n = 90) 22–44 years old who participated in Faroe Islands health studies were analyzed for p,p´-DDE and PCBs 118, 138, 153, and 180 and adjusted for total lipids. Cord blood and age-14 serum were available for a subgroup (n = 40) and were also analyzed for p,p´-DDE and PCBs. Sperm fluorescence in situ hybridization (FISH) for chromosomes X, Y, and 18 was used to determine rates of XX18, XY18, YY18, and total disomy. Multivariable adjusted Poisson models were used to estimate the relationship between organochlorine exposure and sperm disomy outcomes.

Results:

Adult p,p´-DDE and total PCB serum concentrations were both associated with significantly increased rates of XX18, XY18, and total disomy. Age-14 p,p´-DDE and PCB concentrations were both associated with significantly increased rates of XX, XY, and total disomy in adulthood. Associations between cord blood concentrations of p,p´-DDE and PCBs and sperm disomy in adulthood were not consistently significant.

Conclusions:

Organochlorine exposures measured at age 14 and in adulthood were associated with sperm disomy in this sample of high-exposure men, suggesting that the impacts of persistent pollutants on testicular maturation and function require further investigation.

Citation:

Perry MJ, Young HA, Grandjean P, Halling J, Petersen MS, Martenies SE, Karimi P, Weihe P. 2016. Sperm aneuploidy in Faroese men with lifetime exposure to dichlorodiphenyldichloroethylene (p,p´-DDE) and polychlorinated biphenyl (PCB) pollutants. Environ Health Perspect 124:951–956; http://dx.doi.org/10.1289/ehp.1509779  相似文献   

5.
The present study evaluated the effects of field metal contamination on sperm motility and the RNA/DNA ratio in echinoderms. Populations of Asterias rubens and Echinus acutus that occur naturally along a contamination gradient of sediments by cadmium, copper, lead, and zinc in a Norwegian fjord (the S?rfjord) were studied. Sperm motility, a measure of sperm quality, was quantified using a computer-assisted sperm analysis system. The RNA/DNA ratio, a measure of protein synthesis, was assessed by a one-dye (ethidium bromide)/one-enzyme (RNase), 96-well microplate fluorometric assay. Although both species accumulate metals at high concentrations, neither sperm motility parameters in A. rubens nor the RNA/DNA ratio in both species were affected. The S?rfjord is still one of the most metal-contaminated marine sites in Europe, but even so, populations of A. rubens and E. acutus are able to endure under these conditions.  相似文献   

6.
Residues ofp,p dicofol,p,p dichlorobenzophenone (p,p DCBP),p,p dichlorobenzhydrol (p,p DCBH), 1,1-bis (4-chlorophenyl)-2,2-dichloroethanol (p,p DCD) and 1,1-bis (4-chlorophenyl)-2,2 dichloroethylene (p,p DDE) are reported in liver, fat, brain and oviducts of American kestrels exposed top,p dicofol. Breeding female kestrels were exposed to oral gavage dosages of 3.0 and 0.3 mg dicofol/kg body weight per day, equivalent to 1 or 10 mg dicofol/kg diet, for 39 days. Kestrels exhibited an eggshell thinning response similar to that produced by DDE, under these exposures. The major hepatic metabolite of dicofol in kestrels was DCD, but most organochlorine stored in tissues was in the form of dicofol. DDE was not a major metabolite of dicofol in kestrels. Compared with doves, kestrels had a significantly reduced metabolic capacity to transform dicofol to DCBP and DCBH, and had a steeper dose-response curve for dicofol-induced eggshell thinning.  相似文献   

7.
We characterized genome segments 2, 3 and 6 (Seg-2, Seg-3 and Seg-6) of 11 Japanese strains of epizootic hemorrhagic disease (EHD) virus (EHDV) isolated in 1985–2013. The Japanese strains were divisible into two groups based on phylogenetic analyses of the nucleotide sequences of Seg-2 and Seg-6. In both of the phylogenetic trees based on Seg-2 and Seg-6, seven of the 11 Japanese strains were grouped together with EHDV-2 and EHDV-7 strains, and the other four Japanese strains were grouped with EHDV-1 strains. The phylogenetic analysis of Seg-2 among EHDV strains identified 10 of the 11 Japanese strains as EHDV-1, EHDV-2 or EHDV-7. The other Japanese strain, ON-4/B/98, isolated from an asymptomatic cow in 1998 was in the same group as the EHDV-2 and EHDV-7 strains in the phylogenetic trees based on Seg-2 and Seg-6, but the results suggested that the strain belongs to another serotype. We thus conducted a serum neutralization test to identify that serotype by using anti-EHDV-2 and anti-EHDV-7 rabbit sera. We observed that the ON-4/B/98 strain was not sufficiently neutralized by any of the antisera, which suggests that the strain could be assigned into a new serotype, tentatively named ‘EHDV-10.’ Sequences of Seg-3 were also determined, and all of the Japanese strains were grouped together with Australian strains, suggesting that the Japanese strains are a part of EHDV distributed in the Asia-Pacific region. The data obtained herein would be beneficial for the diagnosis and prevention of EHD in Japan and neighboring countries.  相似文献   

8.
《Vaccine》2016,34(8):1097-1102
Viral hemorrhagic septicemia virus (VHSV) is the causative agent of viral hemorrhagic septicemia in fish, a disease that affects a number of teleost fish species including olive flounder (Paralichthys olivaceus). In this study, we assessed the safety and efficacy of two recombinant attenuated VHSV strains, termed A4G-G5A and ΔNV, with the purpose to select the most suitable vaccine strain. The virus strains were passaged in two commercially available cell lines, EPC and RTG-2, and the strains were also tested for residual virulence in zebrafish (Danio rerio). The A4G-G5A strain showed an attenuated growth profile in both the EPC and RTG-2 cell lines compared to wild-type (WT) VHSV (JF-09, genotype IVa), whereas the growth profile of ΔNV was comparable to the WT strains in RTG-2 cells in contrast to EPC cells. Moreover, ΔNV had higher residual virulence compared to A4G-G5A and was highly pathogenic to zebrafish. The A4G-G5A strain was chosen as vaccine candidate and tested for efficacy in in vivo fish studies in the target species, olive flounder, using an immersion vaccine scheme. Groups of fish were immunized with 102.5, 103.5, 104.5, and 105.5 TCID50/ml of A4G-G5A giving 5–13.3 cumulative percent mortality (CPM) post immunization. Immunization was followed by a challenge experiment using VHSV-WT. The relative percent survival (RPS) in immunized groups ranged from 81.6% to 100%, correlating with vaccination dose. This study demonstrates that while strain A4G-G5A has retained some residual virulence it confers high level of protection in immunized olive flounder.  相似文献   

9.
《Vaccine》2020,38(35):5707-5717
BackgroundThe 2018/2019 influenza season in the WHO European Region was dominated by influenza A (H1N1)pdm09 and (H3N2) viruses, with very few influenza B viruses detected.MethodsCountries in the European Region reported virus characterization data to The European Surveillance System for weeks 40/2018 to 20/2019. These virus antigenic and genetic characterization and haemagglutinin (HA) sequence data were analysed to describe and assess circulating viruses relative to the 2018/2019 vaccine virus components for the northern hemisphere.ResultsThirty countries reported 4776 viruses characterized genetically and 3311 viruses antigenically. All genetically characterized A(H1N1)pdm09 viruses fell in subclade 6B.1A, of which 90% carried the amino acid substitution S183P in the HA gene. Antigenic data indicated that circulating A(H1N1)pdm09 viruses were similar to the 2018/2019 vaccine virus. Genetic data showed that A(H3N2) viruses mostly fell in clade 3C.2a (75%) and 90% of which were subclade 3C.2a1b. A lower proportion fell in clade 3C.3a (23%) and were antigenically distinct from the vaccine virus. All B/Victoria viruses belonged to clade 1A; 30% carried a double amino acid deletion in HA and were genetically and antigenically similar to the vaccine virus component, while 55% carried a triple amino acid deletion or no deletion in HA; these were antigenically distinct from each other and from the vaccine component. All B/Yamagata viruses belonged to clade 3 and were antigenically similar to the virus component in the quadrivalent vaccine for 2018/2019.ConclusionsA simultaneous circulation of genetically and antigenically diverse A(H3N2) and B/Victoria viruses was observed and represented a challenge to vaccine strain selection.  相似文献   

10.
Whole blood samples were taken from 101 women (26±4 years) entering maternity facilities in upstate New York. At birth, fetal cord blood was also collected. The samples were analyzed for 74 polychlorobiphenyl (PCB) congeners,p,p-DDE, mirex, and hexachlorobenzene by glass capillary gas chromatography with electron capture detection. Maternal blood contained 3.5±1.1 ng total PCB/g whole blood and fetal cord blood contained 2.4±1.0 ng total PCB/g whole blood, which indicate that the women are less contaminated than women surveyed elsewhere in the U.S. Of the 77 compounds measured, only 20 occurred in more than 10% of the maternal samples at levels >0.01 ng/g. Mirex was not detected. Although the concentration of the majority of congeners,p,p-DDE and hexachlorobenzene correlated in maternal and fetal cord blood, 2,5,2,5-tetrachlorobiphenyl and hexachlorobenzene crossed the placenta preferentially. Apparently, the population contains vestiges of Aroclor® 1242 (the PCB mixture used in electrical equipment) and Aroclor® 1260 (the mixture used as a plasticizer).p,p- DDE was the pollutant present at highest concentration (maternal 3.8±0.8 ng/g, fetal cord 1.9±0.9 ng/g).  相似文献   

11.
Although at least 30 novel hantaviruses have been recently discovered in novel hosts such as shrews, moles and even bats, hantaviruses (family Bunyaviridae, genus Hantavirus) are primarily known as rodent-borne human pathogens. Here we report on identification of a novel hantavirus variant associated with a rodent host, Major’s pine vole (Microtus majori).Altogether 36 hantavirus PCR-positive Major’s pine voles were identified in the Krasnodar region of southern European Russia within the years 2008–2011. Initial partial L-segment sequence analysis revealed novel hantavirus sequences. Moreover, we found a single common vole (Microtus arvalis) infected with Tula virus (TULV). Complete S- and M-segment coding sequences were determined from 11 Major’s pine voles originating from 8 trapping sites and subjected to phylogenetic analyses.The data obtained show that Major’s pine vole is a newly recognized hantavirus reservoir host. The newfound virus, provisionally called Adler hantavirus (ADLV), is closely related to TULV. Based on amino acid differences to TULV (5.6–8.2% for nucleocapsid protein, 9.4–9.5% for glycoprotein precursor) we propose to consider ADLV as a genotype of TULV. Occurrence of ADLV and TULV in the same region suggests that ADLV is not only a geographical variant of TULV but a host-specific genotype. High intra-cluster nucleotide sequence variability (up to 18%) and geographic clustering indicate long-term presence of the virus in this region.  相似文献   

12.
13.
Objectives: It has been shown that calcitriol and all-trans retinoic acid (ATRA) have modulatory effects on the immune system. The present study investigates the synergistic effects of combination treatment of calcitriol and ATRA in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS).

Methods: The mice were allocated to four preventive groups, each consisting of eight animals, ATRA (250 μg/mouse), calcitriol (100?ng/mouse), combination of ATRA and calcitriol (125 μg/mouse and 50?ng/mouse) and vehicle groups. EAE was induced by MOG35-55 peptide in female C57BL/6 mice. Treatments were initiated at day 1 before immunization and continued every other day throughout the study until the day 21 post-immunization. Splenocytes were isolated from EAE-induced mice and the expression of retinoic acid receptor-related orphan receptor gamma t (ROR-γt), Interleukin-17 (IL-17), transforming growth factor beta (TGF-β), and forkhead box P3 (FOXP3) genes was measured using real-time polymerase chain reaction.

Results: The expression of FOXP3 and TGF-β genes in the splenocytes of combination-treated and calcitriol alone-treated mice was significantly increased compared to vehicle group (P?The expression of ROR-γt and IL-17 genes in the splenocytes of ATRA, calcitriol and combination- treated mice was significantly reduced compared to those of vehicle- treated mice (P?P?Discussion: This study demonstrated that treatment with combination of calcitriol and ATRA can be considered as a new strategy for MS prevention and treatment.  相似文献   

14.
Objectives Herpes simplex virus type 1 and type 2 (HSV-1 and HSV-2) are both highly prevalent. The rate of genital HSV-1 transmission is reportedly increasing over time. HSV-2 is considered to be an important risk factor for HIV transmission. We therefore studied changes in the HSV-1 and HSV-2 prevalence in a large cohort of men who have sex with men (MSM) over a 20-year time period. Methods Among 1847 HIV-infected and HIV-uninfected MSM participating in the Amsterdam Cohort Studies, seroprevalence of HSV-1 and HSV-2 was determined and prevalence rate ratios (PRR) and 95% confidence intervals were calculated. Results Between 1984 and 2003 the HSV-1 and HSV-2 prevalence decreased among HIV-uninfected MSM (P < 0.001), but remained stable among HIV-infected MSM. HSV-1 prevalence increased among men with at least 200 sexual partners over lifetime (PRR: 1.49, P < 0.001). The association between HIV infection and HSV-2 became stronger over time (PRR: 3.45, P < 0.001). Conclusions Seroprevalence of HSV-1 and HSV-2 remained high among HIV infected MSM from 1984 to 2003. The association of HIV and HSV-2 increased during the HIV epidemic. Since the proportion of sexual transmission of HSV-1 is rising, it is important to study the potential role of HSV-1 as risk factor for HIV acquisition.  相似文献   

15.
16.

Purpose

Cadmium in urine is positively associated with urinary 8-oxo-7,8-dihydro-2′-deoxyguanosine (8-oxodG) concentrations, a sensitive marker of oxidative DNA damage. We determined whether kidney concentrations of cadmium, mercury, and lead, which may generate oxidative DNA damage, were associated with urinary 8-oxodG or not.

Methods

8-OxodG was measured in separate 24 h and overnight urine samples from Swedish healthy adult kidney donors (N = 152) using LC–MS/MS. Concentrations of metals were measured in kidney biopsies (N = 109) by ICP-MS.

Results

The median 8-oxodG concentrations (adjusted to specific gravity) in 24 h and overnight samples were 13.5 and 15.3 nmol/L; 8-oxodG excretion rates in 24 h and overnight samples were 0.93 and 0.86 nmol/h. In multivariable linear regression analyses, we did not find any association between 8-oxodG concentrations or rates and elements in the kidney. The 24-h 8-oxodG concentrations were positively associated with serum ferritin (β = 0.048, p < 0.0001), body weight (β = 0.13, p = 0.0019), and inversely with gender (β = ?3.34, p = 0.0024). Similar associations with 8-oxodG excretion rates were stronger. Smoking was positively associated with 24-h 8-oxodG excretion rates (β = 0.26, p = 0.0090), but not with overnight samples.

Conclusions

Neither cadmium, nor mercury or lead in the kidney contributed to urinary 8-oxodG concentrations in non-occupationally exposed subjects. The iron status was positively associated with urinary 8-oxodG, particularly in women.  相似文献   

17.
Summary An erythrocyte pyrimidine 5-nucleotidase (P5N) test was performed for 171 workers occupationally exposed to lead. Erythrocyte P5N activity was markedly inhibited by exposure to lead. Among several biological indicators (erythrocyte P5N, -aminolevulinic acid dehydratase (ALAD), protoporphyrin (PROTO), urinary -aminolevulinic acid (ALA), coproporphyrin (COPRO)), the P5N activity had the highest correlation with the concentration of lead in blood (r = – 0.77). A significant inhibition of erythrocyte P5N was found in groups of lead workers with blood-lead levels of more than 10 to 19 g/dl. This P5N inhibition started before any changes occurred in urinary ALA and COPRO. A 45 to 50% inhibition of P5N corresponded to the blood-lead value (50 g/dl) of the BEI recommended by ACGIH. In some lead workers, erythrocyte nucleotides (mainly CTP and UTP) were determined. The data indicated that a marked accumulation of these nucleotides had occurred, and their levels correlated negatively with P5N activity and positively with blood lead.  相似文献   

18.
Background: Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs.Objectives: We estimated the association between bulky DNA adduct levels and birth weight in a multicenter study and examined modification of this association by maternal intake of fruits and vegetables during pregnancy.Methods: Pregnant women from Denmark, England, Greece, Norway, and Spain were recruited in 2006–2010. Adduct levels were measured by the 32P-postlabeling technique in white blood cells from 229 mothers and 612 newborns. Maternal diet was examined through questionnaires.Results: Adduct levels in maternal and cord blood samples were similar and positively correlated (median, 12.1 vs. 11.4 adducts in 108 nucleotides; Spearman rank correlation coefficient = 0.66, p < 0.001). Cord blood adduct levels were negatively associated with birth weight, with an estimated difference in mean birth weight of –129 g (95% CI: –233, –25 g) for infants in the highest versus lowest tertile of adducts. The negative association with birth weight was limited to births in Norway, Denmark, and England, the countries with the lowest adduct levels, and was more pronounced in births to mothers with low intake of fruits and vegetables (–248 g; 95% CI: –405, –92 g) compared with those with high intake (–58 g; 95% CI: –206, 90 g)Conclusions: Maternal exposure to genotoxic agents that induce the formation of bulky DNA adducts may affect intrauterine growth. Maternal fruit and vegetable consumption may be protective.Citation: Pedersen M, Schoket B, Godschalk RW, Wright J, von Stedingk H, Törnqvist M, Sunyer J, Nielsen JK, Merlo DF, Mendez MA, Meltzer HM, Lukács V, Landström A, Kyrtopoulos SA, Kovács K, Knudsen LE, Haugen M, Hardie LJ, Gützkow KB, Fleming S, Fthenou E, Farmer PB, Espinosa A, Chatzi L, Brunborg G, Brady NJ, Botsivali M, Arab K, Anna L, Alexander J, Agramunt S, Kleinjans JC, Segerbäck D, Kogevinas M. 2013. Bulky DNA adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother–child study (NewGeneris). Environ Health Perspect 121:1200–1206; http://dx.doi.org/10.1289/ehp.1206333  相似文献   

19.
20.
BackgroundGenetic variants of the genes encoding HIV-1 co-receptors and their ligands, CCR5-Δ32, CCR5m303A, CCR2-64I and SDF1-3′A, are implicated in the susceptibility to HIV-1 infection, and the prevalence of these mutations varies by ethnicity. However, little is known about their distribution in Uighurs.ObjectivesThis study aimed at characterizing the frequency of these HIV-related gene variants in a high-risk Uighur population.Study designsA total of 251 HIV-1 seropositive and 238 seronegative high-risk Uighurs were recruited and their genotypes of CCR5-Δ32, CCR5m303A, CCR2-64I and SDF1-3′A were analyzed by PCR and PCR-ligase detection reaction (PCR-LDR).ResultsThe allelic frequency of CCR5-Δ32, CCR5m303A, CCR2-64I and SDF1-3′A was 4.40%, 2.66%, 25.66% and 57.36%, respectively, in this population. Apparently, the Uighur population has low frequency of CCR5-Δ32 and CCR5m303A, but high frequency of CCR2-64I and SDF1-3′A. While there was no significant difference in the frequency of CCR5-Δ32, CCR2-64I and SDF1-3′ A between HIV-1 seropositive and seronegative groups the frequency of CCR5m303A in HIV-1 seropositive group was significantly higher than that in seronegative group (P = 0.006, OR = 3.982 and 95%CI 1.514–10.476).ConclusionsOur data suggest that the CCR5-Δ32, CCR2-64I and SDF1-3′A variants may have limited effect on protecting from HIV-1 infection in Uighurs. Rather, the CCR5m303A may be associated with the risk for HIV-1 infection in high-risk Uighurs.  相似文献   

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