Populations In Central China Research Articles

Historical survey of the kdr mutations in the populations of Anopheles sinensis in China in 1996-2014.

BackgroundAnopheles sinensis has become an important malaria vector in China. The long-term extensive utilization of pyrethroids for ITNs and IRS for mosquito control in the last three decades has resulted in the occurrence of resistant An. sinensis populations in many regions. Knockdown resistance (kdr), caused by point mutations in the VGSC gene, is one of the mechanisms that confer resistance to DDT and pyrethroids. Recently, several investigations revealed the kdr occurrence in some An. sinensis populations, however, no kdr data were available earlier than 2009. A survey tracking the dynamics of the kdr mutations in past decades would provide invaluable information to understand how the kdr alleles spread in mosquito populations temporally and spatially.MethodsA survey was conducted on the kdr alleles at condon 1014 of the VGSC gene and their distributions in 733 specimens of An. sinensis and 232 specimens of the other eight member species of the Anopheles hyrcanus group that were collected from 17 provinces in China in 1996–2014.ResultsA total of three kdr alleles, TTT (F), TTG (F) and TGT (C) were detected, and TGT (C) and TTT (F) were already present in the specimens from Jiangsu and Shandong as early as 1997. The TTT (F) was the most frequent mutant allele, and largely distributed in central China, namely Shandong, Jiangsu, Anhui, Henan, Shanghai, Jiangxi and Hubei. When data were analysed in three time intervals, 1996–2001, 2005–2009, 2010–2014, the prevalence of kdr alleles increased progressively over time in the populations in central China. In contrast, the kdr alleles were less frequent in the samples from other regions, especially in Yunnan and Hainan, despite the documented presence of pyrethroid resistant populations in those regions. Interestingly, no mutant alleles were detected in all 232 specimens of eight other species in the An. hyrcanus group.ConclusionThe survey revealed that the kdr occurrence and accumulation in the An. sinensis populations were more frequent in central China than in the other regions, suggesting that the kdr mutations may contribute significantly to the pyrethroid resistance in the mosquitoes in central China.Electronic supplementary materialThe online version of this article (doi:10.1186/s12936-015-0644-0) contains supplementary material, which is available to authorized users.

Tumor Necrosis Factor-Related Apoptosis Inducing Ligand Gene Polymorphisms are Correlated with Gastric Cancer in Central China

To investigate the association of tumor necrosis factor-related apoptosis inducing ligand (TRAIL) gene polymorphisms with gastric cancer in Chinese Han population in central China. A total of 304 patients with gastric cancer confirmed by histopathology and 421 unrelated healthy controls were studied. Gene polymorphisms of TRAIL (G1525A and C1595T) were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) analysis. The frequency of the genotype carriers of TRAIL 1525A (GA + AA) and 1595T (CT + TT) was significantly lower in gastric cancer than in healthy controls (37.2% vs. 61.5%, P < 0.001, OR = 0.581, 95% CI 0.442 ~ 0.764; 36.2% vs. 62.0%, P < 0.001, OR = 0.570, 95% CI 0.433 ~ 0.750, respectively). Stratification analysis showed that both TRAIL 1525A (GA + AA) and 1595T (CT + TT) carriers were associated with poorly-differentiated gastric cancer compared to 1525GG genotype and 1595CC genotype (OR = 0.516, 95%CI 0.279 ~ 0.957, P = 0.026; OR = 0.395, 95%CI 0.207 ~ 0.753, P = 0.004, respectively). TRAIL G1525A and C1595T gene polymorphisms were significantly correlated with the susceptibility to gastric cancer in Chinese Han population in central China.

Correction: Epidemiological Analysis of HTLV-1 and HTLV-2 Infection among Different Population in Central China

Correction: Epidemiological Analysis of HTLV-1 and HTLV-2 Infection among Different Population in Central China

Epidemiological Analysis of HTLV-1 and HTLV-2 Infection among Different Population in Central China

BackgroundHTLV-1 and HTLV-2 are retroviruses linked etiologically to various human diseases, and both of them can be transmitted by vertical route, sexual intercourse, blood transfusion and intravenous drug use. Recently, some HTLV-infected cases have been reported and this virus is mainly present in the Southeast coastal areas in China, but has not been studied for the people in Central China.ObjectivesTo know the epidemiologic patterns among different population samples in Central China and further identify risk factor for HTLV-1 and HTLV-2 infection.MethodsFrom January 2008 to December 2011, 5480 blood samples were screened for HTLV-1/2 antibodies by using enzyme immunoassay, followed by Western Blot.ResultsThe prevalence of HTLV-1 and HTLV-2 was found with infection rates 0.13% and 0.05% among all population samples for HTLV-1 and HTLV-2, respectively. The highest percentages of infection, 0.39% and 0.20%, were found in the high risk group, while only 0.06% and 0.03% in the blood donor group. There was only one case of HTLV-1 infection (0.11%) among patients with malignant hematological diseases. Of seven HTLV-1 positive cases, six were co-infected with HBV, two with HCV and one with HIV. Among three HTLV-2 positive individuals all were co-infected with HBV, one with HCV.ConclusionsHTLV-1 and HTLV-2 have been detected in the Central China at low prevalence, with the higher infection rate among high risk group. It was also found that co-infection of HTLV-1/2 with HIV and HBV occurred, presumably due to their similar transmission routes. HTLV-1/2 antibody screen among certain population would be important to prevent the spread of the viruses.

Prevalence of Drug Resistance-Associated Gene Mutations in Plasmodium vivax in Central China

Resistance of Plasmodium spp. to anti-malarial drugs is the primary obstacle in the fight against malaria, and molecular markers for the drug resistance have been applied as an adjunct in the surveillance of the resistance. In this study, we investigated the prevalence of mutations in pvmdr1, pvcrt-o, pvdhfr, and pvdhps genes in temperate-zone P. vivax parasites from central China. A total of 26 isolates were selected, including 8 which were previously shown to have a lower susceptibility to chloroquine in vitro. For pvmdr1, pvcrt-o, and pvdhps genes, no resistance-conferring mutations were discovered. However, a highly prevalent (69.2%), single-point mutation (S117N) was found in pvdhfr gene. In addition, tandem repeat polymorphisms existed in pvdhfr and pvdhps genes, which warranted further studies in relation to the parasite resistance to antifolate drugs. The study further suggests that P. vivax populations in central China may still be relatively susceptible to chloroquine and sulfadoxine-pyrimethamine.

Erratum to: Hyperhomocysteinemia and Related Genetic Polymorphisms Correlate with Ulcerative Colitis in Chinese Han population in Central China

Unfortunately the title of the article was furnished incorrectly in the original publication of the article. The population and UC patients should be Chinese Han population in Central China, not Southeast China. Therefore, the title of the article should be ‘‘Hyperhomocysteinemia and Related Genetic Polymorphisms Correlate with Ulcerative Colitis in Chinese Han population in Central China’’, and related term in the text should be corrected. Moreover, the affiliation and email address of the corresponding author, Prof. Bing Xia, is corrected in this erratum.

Monitoring resistance of Plasmdium vivax: point mutations in dihydrofolate reductase gene in isolates from Central China.

BackgroundMalaria still represents a significant public health problem in China, and the cases dramatically increased in Central China after 2001. Antifolate resistance in Plasmodium vivax is caused by point mutations in genes encoding dihydrofolate reductase (pvdhfr) and dihydropteroate synthase (pvdhps). In this study, we used direct sequencing to investigate genetic variation in pvdhfr of malaria patients' samples from Central China.ResultsAmong all the samples, 21.4% were wild-type, whereas mutations were detected at three codons (58, 61 and 117) including single mutant (34.6%) and double mutants (43.8%). The most prevalent mutant allele was the one with double mutation at codons 58 and 117 (24.6%). Three types of single mutation (S58R, T61M and S117N) were found in 2.1%, 11.8% and 20.9% of parasite isolates, respectively. The four P. vivax parasite populations in Central China also differed in pvdhfr allele frequencies.ConclusionsThis study suggested that P. vivax in Central China may be relatively susceptible to pyrimethamine. And it also highlights genotyping in the pvdhfr genes remains a useful tool to monitor the emergence and spread of P. vivax pyrimethamine resistance.

Genetic polymorphisms of glutathione S-transferases are associated with ulcerative colitis in central China

The present study aimed to investigate the association between genetic polymorphisms of glutathione S-transferases (GSTs) and susceptibility to ulcerative colitis (UC) in central China. The prevalence of GSTM1, GSTT1, and GSTP1 gene polymorphisms were examined using polymerase chain reaction methods in 270 consecutive UC patients and 623 age- and sex-matched healthy controls. The frequencies of the GSTM1(null) and GSTT1(null) as well as GSTP1 (Val/Val) genotypes were significantly higher in UC patients than in the controls (70.74% vs. 41.74%, P = 0.0001; 64.82% vs. 47.19%, P = 0.0001; and 48.89% vs. 34.35%, P = 0.0004, respectively). When the UC patients were stratified according to clinical features, we found that the frequencies of the GSTT1(null) and GSTP1 (Val/Val) genotypes but not the GSTM1(null) genotype were significantly higher in patients with distal colitis than in extensive colitis (P = 0.0007, P = 0.001, and P = 0.271, respectively). However, these variant GST genotypes were not significantly linked to severity of the disease (P > 0.05). GST variant genotypes are strongly correlated with prevalence and extent but not with severity of UC in the Hubei Han population in central China.

CTLA-4 Gene Polymorphism and the Risk of Systemic Lupus Erythematosus in the Chinese Population

Several variants of CTLA-4 have been reported to be associated with susceptibility systemic lupus erythematosus (SLE); however, findings have been inconsistent across different populations. Using a case-control study design, we have investigated the role of CTLA-4 polymorphism at positions −1661 and −1722 on SLE susceptibility in our Chinese SLE population in central China's Hubei province. Samples were collected from 148 SLE patients and 170 healthy controls. Polymerase chain reaction restriction fragments length polymorphism (PCR-RFLP) was used to analyze the genotypes of the two sites. Statistically significant difference was observed in genotypes for −1722, but not for −1661. The frequency of the T allele on the −1722 SNP was significantly increased in SLE patients: 57.8% versus 40.6% in controls (P < 0.001, OR = 2.002). While the detected C allele frequency in the controls was significantly elevated in comparison to that in the SLE patients (59.4% versus 42.2%). On the contrary, no association was found between SLE and CTLA-4 polymorphism at position −1661.

Étude du site de Longgupo – Synthèse

If the hominids are of African origin, as data support, we can hypothesize that the date of the first population diffusion must be moved back to 2.5–2.6 mya, and that the first populations in central China were oriented toward new technological options, which are only found in Africa much later. In the present state of research, it appears that we should abandon our old paradigms, which have over time become “truths”, because instead of a unifying view–monolithic–of these periods, we advocate recognition of the existence of spatial and temporal cultural otherness.

Identifying the effects of the Pleistocene on the greater horseshoe bat, Rhinolophus ferrumequinum, in East Asia using ecological niche modelling and phylogenetic analyses

Aim The extent to which the ranges of temperate biota in East Asia have been shaped by geological and climatic changes during the Pleistocene remains poorly understood. Previous molecular-based studies of the greater horseshoe bat (Rhinolophus ferrumequinum), which is widespread across China and Japan, suggest that this species was able to persist in multiple refugia in this region. However, limited availability of samples precluded a detailed analysis of past distributions. By integrating ecological niche modelling with phylogenetic analyses, we aim to resolve the impact of past events on the population genetic structure of R. ferrumequinum and provide detailed descriptions of potential distribution patterns during this time. Location Central/East China and Japan. Methods Phylogenetic analyses were carried out using 1098 bp of the mitochondrial ND2 gene and 13 microsatellite loci from bats sampled at 26 localities across China and Japan. Haplotype data were used in isolation-with-migration models (IMa) to estimate divergence dates between different lineages, and mismatch distribution analyses were undertaken to test for signs of population expansion. Geographical structuring of the microsatellite data was examined by spatial clustering. Ecological niche modelling was performed based on high-resolution palaeoclimate data inferred for the Last Glacial Maximum (LGM). Results Phylogenetic analyses identified deep levels of divergence between three major lineages broadly corresponding to Central China, East China and Japan. The divergence of all three lineages was estimated to have occurred before the LGM. A strong correlation was observed between the ecological niche model and phylogenetic data, with both methods inferring that R. ferrumequinum populations in Central China did not undergo significant range contractions during glacial episodes. The impact of glacial cycles on East China would have been more severe, with some locations being unable to support viable populations. Zones of secondary contact were identified between Central/East China and East China/Japan, which probably result from some historical gene flow between isolated populations. Main conclusions Integrating ecological niche modelling within phylo-geographical studies provides support for a complex demographic history for R. ferrumequinum in East Asia, as well as persistence during glacial episodes in multiple refugia across their range.

Hepatitis E Virus Infection in Central China Reveals No Evidence of Cross-Species Transmission between Human and Swine in This Area

Hepatitis E virus (HEV) is a zoonotic pathogen of which several species of animal were reported as reservoirs. Swine stands out as the major reservoir for HEV infection in humans, as suggested by the close genetic relationship of swine and human virus. Since 2000, Genotype 4 HEV has become the dominant cause of hepatitis E disease in China. Recent reports showed that genotype 4 HEV is freely transmitted between humans and swine in eastern and southern China. However, the infection status of HEV in human and swine populations in central China is still unclear. This study was conducted in a rural area of central China, where there are many commercial swine farms. A total of 1476 serum and 554 fecal specimens were collected from the general human and swine populations in this area, respectively. The seroepidemiological study was conducted by enzyme-linked immunosorbent assay. Conserved genomic sequences of open reading frame 2 were detected using reverse transcription-PCR. The results indicated that the overall viral burden of the general human subjects was 0.95% (14/1476), while 7.0% (39/554) of the swine excreted HEV in stool. The positive rate of anti-HEV IgG and IgM in the serum samples was 7.9% (117/1476) and 1.6% (24/1476), respectively. Phylogenetic analysis based on the 150 nt partial sequence of the capsid protein gene showed that the 53 swine and human HEV isolates in the current study all belonged to genotype 4, clustering into three major groups. However, the HEV isolates prevalent in the human and swine populations were classified into known distinct subgenotypes, which suggested that no cross-species transmission between swine and humans had taken place in this area. This result was confirmed by cloning and phylogenetic analysis of the complete capsid protein gene sequence of three representative HEV strains in the three major groups. The cross reactivity between anti-HEV IgG from human sera and the two representative strains from swine in central China was confirmed by Dot-blot assay. In conclusion, although all the HEV strains prevalent in central China belonged to genotype 4, there is no evidence of cross-species transmission between human and swine in this area.

Why Did Metasequoia Disappear from North America but Not from China

Abstract Fossils of Metasequoia, beginning in the Cretaceous Period, have been found throughout the Northern Hemisphere. In North America this genus survived at least through the Pliocene, and in Asia through the early Pleistocene. Fossils from the Holocene are missing on both continents, yet Metasequoia survived, presumably in wet-site refugia along the Yangtze River, and survives today as relic populations in central China. Metasequoia has completely disappeared in North America. We present the case that the ecological requirement of moist bare soil for seedling establishment constrains Metasequoia to regularly disturbed riparian zones. The river systems of the western United States could have provided migratory routes for Metasequoia to the Southeast as climate cooled and land masses rose. However, Taxodium, a genus not found in Asia, has the same specialized seedling establishment requirements as Metasequoia. We previously showed that Metasequoia has the superior photosynthetic system for adapting to ...

Genetic Diversity of Primula ovalifolia from Central and Southwest China Based on ISSR Markers

Primula ovalifolia Franchet (Primulaceae) is mainly distributed in a band through central China to southwest China and grows in moist shady places with the altitude between 1200 - 2500 m. Eighty-five individuals from five natural populations in Hubei (central) and Sichuan (southwest) China were sampled. The inter-simple sequence repeats (ISSR) produced 207 polymorphic band loci and identified 85 ISSR genotypes. The results obtained from calculation of Shannon’s index and Nei’s gene diversity shows that there is no difference of genetic diversity between the three populations in southwest China and two populations in central China. The UPGMA clustering analysis also shows that there is no distinct genetic differentiation between the natural populations in central and southwest China.

Observations on North China Intestinal Parasites of Man 1

Summary 1. An intensive study of third-class patients on the medical service of the Peking Union Medical College Hospital was undertaken to determine the importance of parasitic infection in clinical diagnoses in North China. 2. Sixty cases were studied. Each case was under careful scrutiny for a period of ten days or more, during which time every stool passed by the patient was examined. In all, 1409 stools were studied, or an average of 23.48 per patient. 3. Controlled methods of preparation of the stool for examination indicated that concentration methods were valuable only where a single specimen of stool was available for study. In cases where large numbers of stools of the same patient were examined concentration methods added only ten per cent to the findings. Forty per cent of the infections were diagnosed after the first day, 35 per cent of which were diagnosed first from unconcentrated preparations. 4. Eighty per cent of the cases studied harbored intestinal entozoa. While this infective incidence is comparable to that of a sick population in Central China, it is less intensive than the latter. The respective indices for the two areas are as follows: Central China (Wuchang survey), protozoa, 228.7; helminths, 234.3; North China (present study), protozoa, 101.6; helminths, 88.03. 5. The clinical significance of the study is demonstrated by the fact that 53.3 per cent of the series harbored clinically important parasite infections. Twenty per cent of the cases had a major diagnosis due to parasites; 46.6 per cent had a minor diagnosis of parasites; 13.3 per cent of the cases had both major and minor diagnoses occasioned by infections of the digestive tract due to parasites. 6. Nor proof can be advanced from the present study regarding flagellate entozoa in amoebic dysentery that there is a necessary relationship between the two infections. 7. In the cases studied at least 89 per cent of the patients secured their infections in the North China nosogeographic area. They belong to the lower middle class and the poor class, which groups, on account of undernourishment are likely to be more troubled with clinically important infections than are the upper classes. 8. The Chinese as a people are not less susceptible to parasitic infection than other peoples, although light infections among Chinese are less likely to be clinically significant than in Occidentals living in China. 9. Improper disposal of nightsoil is responsible for all of the helminthic infections in the intestinal tract of man in North China as determined by this study.