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X Q Zhu

Publications and source records attributed to X Q Zhu.

At least 19 recordsLinked to original sources
PubMed2006

Practical PCR tools for the delineation of Contracaecum rudolphii A and Contracaecum rudolphii B (Ascaridoidea: Anisakidae) using genetic markers in nuclear ribosomal DNA.

Using genetic markers defined previously in the internal transcribed spacers (ITS-1 and ITS-2) of nuclear ribosomal DNA (rDNA), PCR-coupled restriction fragment length polymorphism (PCR-RFLP) and specific PCR assays were established for the specific detection of each of two morphologically indistinguishable operational taxonomic units (Contracaecum rudolphii A and Contracaecum rudolphii B) within Contracaecum rudolphii (s.l.) and their differentiation from Contracaecum septentrionale, a closely related congener. Application of these tools to C. rudolphii (s.l.) adults from Phalacrocorax carbo sinensis (the Eurasian subspecies of the great cormorant) from Qinghai Lake in China, revealed C. rudolphii B to infect this host. This is the first report of C. rudolphii B in P. carbo sinensis outside of Europe (where it was originally detected), supporting the proposal that this species has a broad geographical distribution. Together with other methods, each of these molecular tools will be useful for investigating the ecology of C. rudolphii A and C. rudolphii B as well as C. septentrionale.

Animals↗
PubMed2006

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine in a commercial trial in broiler chickens in China.

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine were examined and compared with an anticoccidial drug in a trial in broiler chickens under modern commercial conditions in China. In total, 40,660 chickens were used in the present study, half of which were vaccinated with the Supercox vaccine comprising a precocious line of Eimeria tenella and non-attenuated lines of Eimeria maxima and Eimeria acervulina, and the other half were medicated with Diclazuril delivered as feed additive at the dosage of 1mg/kg of feed. The vaccine was administered orally to 7-day-old chickens. No clinical diseases were diagnosed in any of the vaccinated birds. However, clinical coccidiosis occurred in a large proportion of medicated control birds and these chickens had to be treated with anticoccidial drugs (Diclazuril and Toltrazuril). Comparison of production performance between vaccinated birds and medicated control birds revealed that the vaccine Supercox performed better than anticoccidial drugs in terms of mortalities, costs and overall economic benefits (profits). These findings demonstrated that the use of the Supercox vaccine could control clinical coccidiosis in broilers and achieve production performance superior to that using anticoccidial drugs, particularly where drug resistance might result in failure to control clinical diseases.

Animals↗
PubMed2006

Prevalence of helminthes in adult dogs in Heilongjiang Province, the People's Republic of China.

The prevalence of helminthes in adult dogs was investigated in Heilongjiang Province, the People's Republic of China, between 1996 and 2004. A total of 178 adult farm dogs from representative geographical locations in Heilongjiang Province were killed and examined for the presence of helminthes using a helminthological approach. The worms were examined, counted, and identified to species according to existing keys and descriptions. A total of 17 species of helminthes were found to infect dogs, and they represented two phyla, three orders, 13 families, and 15 genera. All dogs were infected by more than one helminth species. Clonorchis sinensis (26.4%), Paragonimus westermani (7.9%), and Metagonimus yokogawai (6.2%) were the most common trematode species; Mesocestoides lineatus (20.2%), Taenia hydatigena (19.7%), and Dipylidium caninum (14.6%) were the most common cestodes species; and Ancylostoma caninum (66.3%), Toxocara canis (36.5%), and Trichinella nativa (21.9%) were the most common nematode species. The results of the present investigation provide relevant "base-line" data for assessing the effectiveness of future control strategies against helminth infection in dogs in Heilongjiang Province, China.

Animals↗
PubMed2006

Survey of helminths in adult sheep in Heilongjiang Province, People's Republic of China.

The prevalence of helminths in adult sheep was investigated in Heilongjiang Province, People's Republic of China between January 1999 and September 2003. A total of 326 adult sheep representing local breeds (Xingjiang Fine Wool Sheep, Dongbei Fine Wool Sheep) as well as introduced breeds (Merino and Charollais) from representative geographical locations in Heilongjiang Province were slaughtered and examined for the presence of helminths. The worms were examined, counted and identified to species according to existing keys and descriptions. A total of 26 helminth species were found representing 2 phyla, 3 classes, 13 families and 20 genera. All sheep were infected by more than one helminth species. Oesophagostomum columbianum, Haemonchus contortus and Trichostrongylus colubriformis were the most common nematode species, and Paramphistomum cervi, Orientobilharzia turkestanica and Fasciola hepatica were the most common trematode species, whereas the infection of adult sheep with cestodes was uncommon. The results of the present investigation provide relevant "base-line" data for Heilongjiang Province, China, for assessing the effectiveness of future control strategies against helminth infections in sheep.

Animals↗
PubMed2006

Characterization of Cryptocaryon irritans isolates from marine fishes in Mainland China by ITS ribosomal DNA sequences.

Seven isolates of Cryptocaryon irritans from different host species and geographical locations in Mainland China were characterized by the first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of nuclear ribosomal DNA (rDNA) using two isolates of Ichthyophthirius multifiliis for comparative purposes. The rDNA region including the ITS-1, 5.8S, ITS-2, and flanking 18S and 28S sequences were amplified by polymerase chain reaction and the amplicons were sequenced directly. The ITS-1, 5.8S, and ITS-2 sequences were 129, 160, and 190 bp in length, respectively, for all seven C. irritans isolates, whereas the corresponding sequences for the two I. multifiliis isolates were 142, 153, and 194 bp, respectively. While sequence variation among the seven C. irritans isolates ranged from 0 to 1.6% in both the ITS-1 and ITS-2, and the two I. multifiliis isolates differed by 1.4% in the ITS-1 and 1.0% in the ITS-2; C. irritans differed from I. multifiliis by 57.1-60.9% in the ITS-1 and 79.4-83.0% in the ITS-2, indicating that ITS sequences provide reliable genetic markers for the identification and differentiation of the two species. Phylogenetic analysis using the sequence pairwise-distance data using the neighbor-joining method inferred that the seven C. irritans isolates from Mainland China and two other isolates (T.A and Aus.C) from other countries clustered together to show monophyly, which could be readily distinguished from the other monophyletic group all from other regions. Therefore, ITS sequence data and phylogenetic analysis provided strong support that C. irritans isolates from Mainland China represent a single species. The definition of genetic markers in the ITS rDNA provide opportunities for studying the ecology and population genetic structures of the C. irritans from Mainland China and elsewhere and is also relevant to the diagnosis and control of fish diseases they cause.

Animals↗
PubMed2006

The radiation of Haliotrema (Monogenea: Dactylogyridae: Ancyrocephalinae): molecular evidence and explanation inferred from LSU rDNA sequences.

The D1-D2 domains of LSU rDNA were used to reconstruct the phylogenetic relationships within the Ancyrocephalinae (Monogenea: Dactylogyridae) utilizing maximum-parsimony (MP), maximum-likelihood (ML), minimum evolution (ME) and neighbour-joining (NJ) methods. A total of 32 monogenean taxa were examined in the present study, including 9 Haliotrema species and 13 other species representing the Ancyrocephalinae, 4 Thaparocleidus species representing the Ancylodiscoididae, and 6 species representing the Diplectanidae which were used as multiple outgroups. All 4 analyses (i.e. MP, ML, ME and NJ) inferred the same interrelationship pattern: (Diplectanidae, (Ancylodiscoididae, Dactylogyridae)) with high bootstrap support. However, 9 Haliotrema species were dispersed to form 4 clades together with species from other genera, indicating the apparent non-monophyly of Haliotrema. Three major groups were defined based on reconstructed phylogenetic trees to explain the radiation of Haliotrema species. The morphology of the reproductive organ, particularly the male copulatory organ (MCO), was discussed to further understand the formation of each group. (1) Results of the present study indicated an intimate relationship among Metahaliotrema (2 species), Protogyrodactylus (4 species) and Haliotrema (2 of 9 species), and notably, all these species share vagina-absence. (2) Based on the present molecular analyses and the morphological characters of the MCO, we propose to transfer H. spirotubiforum and the undetermined Haliotrema sp. ZHDDb to Euryhaliotrema as new combinations. (3) We propose to erect a new genus to accommodate the Haliotrema species with horn-like shaped MCO. Taxonomic implications of the present molecular phylogenetic analyses are discussed. A wider range of taxa and more DNA markers displaying various evolutionary rates should be used to estimate phylogenetic relationships among species within the Ancyrocephalinae and Ancylodiscoididae in further studies.

Animals↗
PubMed2006

The Gly482Ser variant of the PPARGC1 gene is associated with Type 2 diabetes mellitus in northern Chinese, especially men.

AIMS: To investigate the prevalence of the Gly482Ser polymorphism of the PPARGC1 gene in a northern Chinese population and to clarify the susceptibility of individuals with the Gly482Ser polymorphism to insulin resistance and related diseases. METHODS: We studied the association of the Gly482Ser polymorphism identified in the PPARGC1 gene with Type 2 diabetes mellitus (T2DM) in 390 unrelated patients with T2DM and 525 control subjects with normal glucose tolerance. Clinical parameters and measures of insulin resistance were recorded. Genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method, which was further confirmed by direct sequencing in 20 randomly selected cases. RESULTS: The Gly482Ser polymorphism was common in the northern Chinese population. Univariate analysis indicated no statistically significant differences in allele frequencies or genotype frequencies of the Gly482Ser polymorphism in diabetic and control subjects (minor 482Ser allele frequency 44.4 vs. 41.4%, P = 0.169). However, logistic regression analysis demonstrated a positive 1.645-fold higher risk of the Ser/Ser genotype for T2DM (P = 0.039, 95% CI = 1.026-2.632). After stratification by gender, the risk of Type 2 diabetes in men was increased 1.852-fold (95% CI = 1.125-3.049) in those with the Ser/X genotype compared with those with the Gly/Gly genotype (P = 0.015). No associations were observed between the Gly482Ser polymorphism and parameters of insulin resistance, obesity and hypertension. CONCLUSION: The Gly482Ser variant of the PPARGC1 gene might contribute to susceptibility to T2DM in northern Chinese subjects. The Ser/X genotype of the Gly482Ser polymorphism in the PPARGC1 gene appears to be a risk factor for T2DM in northern Chinese men.

Adult↗
PubMed2005

Molecular and morphological evidence indicates that Pseudorhabdosynochus lantauensis (Monogenea: Diplectanidae) represents two species.

Sequences of the first internal transcribed spacer (ITS-1) and the D1-D3 domains of the large subunit (LSU) of the ribosomal DNA (rDNA) were determined for multiple specimens of 4 operational taxonomic units (OTUs) of the monogenean, Pseudorhabdosynochus lantauensis. OTUs were defined based on their collecting localities, host and/or morphological characteristics. All P. lantauensis specimens of one group (OTUs 1 and 3) differed in their sequences of the ITS-1 and partial LSU rDNA when compared with specimens of a second group (OTUs 2 and 4) by 12% and 2%, respectively. Results of the phylogenetic analyses of the LSU rDNA sequence data showed total (100%) bootstrap support for the separation of P. lantauensis into 2 distinct clades. At least 11 of the 18 nucleotide differences in the LSU sequence between the two P. lantauensis clades were derived (i.e. autapomorphic) characters when the morphologically distinct species, P. epinepheli and P. coioidesis, were used as outgroups. Furthermore, there were several autapomorphic character states for each P. lantauensis clade. This provides sufficient evidence to reject the null hypothesis that P. lantauensis represents a single species. Morphological and morphometric differences between these two clades provided additional strong support for the separation of P. lantauensis into two species. These two parasite species were found to co-exist on one of the two species of serranid fish (i.e. Epinephelus coioides) examined in the South China Sea (Guangdong Province, China).

Animals↗
PubMed2004

Survey of intestinal parasites in pigs from intensive farms in Guangdong Province, People's Republic of China.

The prevalence of intestinal parasites was investigated in intensive pig farms in Guangdong Province, China between July 2000 and July 2002. Faecal samples from 3636 pigs (both sexes and five age groups) from 38 representative intensive pig farms employing different parasite control strategies were examined for the presence of helminth ova and protozoan oocysts, cysts and/or trophozoites using standard techniques. Of the 3636 pigs sampled, 209 (5.7%) were infected with Trichuris suis, 189 (5.2%) with Ascaris, 91 (2.5%) with Oesophagostomum spp., 905 (24.9%) with coccidia (Eimeria spp. and/or Isospora suis) and 1716 (47.2%) with Balantidium coli. These infected pigs were mainly from farms without a strategic anti-parasite treatment regime. Concurrent infection of multiple parasites was common, and T. suis was the most common nematode infecting breeding, young and mature pigs. The results of the present investigation provide relevant 'base-line' data for assessing the effectiveness of control strategies against intestinal parasitism in intensively raised pigs in Guangdong Province, China.

Animals↗
PubMed2004

Characterisation of Fasciola species from Mainland China by ITS-2 ribosomal DNA sequence.

Isolates of Fasciola (Platyhelminthes: Trematoda: Digenea) from different host species and geographical locations in Mainland China were characterised genetically. The second internal transcribed spacer (ITS-2) of nuclear ribosomal DNA (rDNA) was amplified from individual trematodes by polymerase chain reaction (PCR), and the representative amplicons were cloned and sequenced. The length of the ITS-2 sequences was 361-362bp for all Chinese Fasciola specimens sequenced. While there was no variation in length or composition of the ITS-2 sequences among multiple specimens from France, Sichuan and Guangxi, sequence difference of 1.7% (6/362) was detected between specimens from France and Sichuan, and those from Guangxi. Based on ITS-2 sequence data, it was concluded that the Fasciola from Sichuan represented Fasciola hepatica, the one from Guangxi represented Fasciola gigantica and the one from sheep from Heilongjiang may represent an "intermediate genotype", as its ITS-2 sequences were unique in that two different ITS-2 sequences exist in the rDNA array within a single Fasciola worm. One of the sequences is identical to that of F. hepatica, and the other is almost identical to that of F. gigantica in that nucleotides at five of the six polymorphic positions represent F. gigantica. This microheterogeneity is possibly due to sequence polymorphism among copies of the ITS-2 array within the same worm. Based on the sequence differences, a PCR-linked restriction fragment length polymorphism (PCR-RFLP) assay was established for the unequivocal delineation of the Fasciola spp. from Mainland China using restriction endonuclease Hsp92II or RcaI. This assay should provide a valuable tool for the molecular identification and for studying the ecology and population genetic structures of Fasciola spp. from Mainland China and elsewhere.

Animals↗
PubMed2003

PCR amplification and sequencing of ITS1 rDNA of Culicoides arakawae.

The first internal transcribed spacer (ITS1) of nuclear ribosomal DNA from Culicoides arakawae was amplified by PCR, cloned and sequenced. The wDNAsis software was used to analyze the ITS1 sequences of C. arakawae and other nine species of Culicoides, which were obtained from GenBank and EMBL databases. For all species, the lengths of the ITS1 were 316-469 bp, and the G+C contents were 26.79-34.53%. Based on the lengths of the ITS1 sequences, the 10 Culicoides species could be divided into two groups. The first group consisted of C. arakawae, C. albicans, C. cubitalis, C. pulicaris and C. punctatus, and the second group comprised C. impunctatus, C. nubeculosus, C. variipennis, C. grisescens and C. imicola. The lengths for the first group were 316-347 bp and the second group were 457-469 bp. C. arakawae belonged to the first group by its ITS1 sequence length. Sequence analysis revealed that C. arakawae was genetically more similar to the first group than it was to the second group, consistent with results based on sequence length. The alignment of ITS1 (the alignment length was 500 bp including the gaps) sequences showed that there was a highly conserved region, which was between 288 and 388 bp, except for a few insertions and substitutions. These findings have important implications for the molecular identification of C. arakawae, for studying its molecular genetics and epidemiology, and for studying the molecular systematics of Culicoides.

Animals↗
PubMed2002

Single-strand conformation polymorphism-based analysis reveals genetic variation within Spirometra erinacei (Cestoda: Pseudophyllidea) from Australia.

This study examined genetic variability within Spirometra erinacei (Cestoda: Pseudophyllidea) from different host species and geographical origins in Australia using a polymerase chain reaction (PCR)-based mutation detection approach, followed by DNA sequencing. Part of the cytochrome c oxidase subunit 1 gene (p cox 1) was amplified by PCR, scanned for sequence variation by single-strand conformation polymorphism (SSCP), and representative samples from different host species were selected for DNA sequencing. While no variation in SSCP profiles was detected among S. erinacei samples from dog, fox, cat, tiger snake and python, they differed in profile from 5 specimens from the green tree frog (Litoria caerulea). This was supported by sequence data which demonstrated that p cox 1 sequences of samples from the latter host species differed at 8 of 393 (2%) nucleotide positions from those from the non-amphibian host. Using a nucleotide difference in the p cox 1 sequence, a PCR-linked restriction fragment length polymorphism (RFLP) could be employed to unequivocally delineate between samples from non-amphibian and amphibian hosts. These findings demonstrate the existence of at least two genotypes within S. erinacei, which may have important implications for studying the epidemiology, ecology and systematics of this cestode.

Animals↗
PubMed2002

Screening for haplotypic variability within Oesophagostomum bifurcum (Nematoda) employing a single-strand conformation polymorphism approach.

Genetic markers in the mitochondrial genome have proven useful for population genetic studies because of their maternal inheritance and relatively high evolutionary rates. In this study, we exploited the high resolution capacity of PCR-coupled single-strand conformation polymorphism (SSCP) to screen for sequence variation in part of the cytochrome c oxidase subunit 1 gene (p cox 1) among individuals of the parasitic nematode, Oesophagostomum bifurcum from human or Mona monkey hosts from Africa. SSCP analysis revealed distinct profiles among some of the individuals, and subsequent sequence analysis of representative samples defined 10 different haplotypes. For comparative purposes, the p cox 1 sequences for representatives of four other species of Oesophagostomum from livestock were included. While there were high levels (11.5-13.7%) of sequence difference among the latter species, there was no fixed nucleotide difference between O. bifurcum individuals from humans and those from monkeys. The data support the proposal that O. bifurcum from the two primate hosts represents a single species and that the haplotypic variability in p cox 1 represents population variation. The results reinforce the usefulness of the SSCP-sequencing approach for studying genetic variation in nematode populations using mitochondrial markers.

Animals↗
PubMed2002

SSCP-based identification of members within the Pseudoterranova decipiens complex (Nematoda: Ascaridoidea: Anisakidae) using genetic markers in the internal transcribed spacers of ribosomal DNA.

The anisakid nematodes morphologically corresponding with Pseudoterranova decipiens sensu lato (s.l.) (Krabbe, 1878) from different seal or sea lion hosts and geographical origins, previously identified as Pseudoterranova krabbei, P. decipiens (s.s.), P. bulbosa, P. azarasi and P. cattani by multilocus enzyme electrophoresis, were characterized using a DNA approach. Also a population of P. decipiens (s.l.) from Chaenocephalus aceratus, the blackfin icefish, from Antarctica and another from Osmerus eperlanus, the European smelt, from Germany were included in the study. The first (ITS-1) and second (ITS-2) internal transcribed spacers (ITS) of ribosomal DNA (rDNA) were amplified by PCR from individual nematodes and analysed by single-strand conformation polymorphism (SSCP), followed by selective sequencing. While no variation in single-stranded ITS-1 and ITS-2 profiles was detected among samples representing each of the species or populations (with the exception of slight microheterogeneity), SSCP analysis of the ITS-2 amplicons allowed the unequivocal differentiation of all of the 5 sibling species of P. decipiens (s.l.) examined, which was supported by sequence differences in ITS rDNA. Samples representing the P. decipiens (s.l.) population from O. eperlanus had the same SSCP profile as those of P. decipiens (s.s.), which was supported by a lack of nucleotide difference in the ITS between them, suggesting that the former represented P. decipiens (s.s.). Based on SSCP results and ITS sequence data, P. decipiens (s.l.) from C. aceratus was genetically most distinct with respect to all other members of Pseudoterranova examined, which indicated that it may represent P. decipiens E (based on geographical origin) or a distinct species. These findings and the molecular approach taken should have important implications for studying the life-cycles, transmission patterns, epidemiology and population genetics of these anisakid nematodes, and the diagnosis of their infections.

Animals↗
PubMed2001

An old but simple and efficient method to elucidate the oxidation mechanism of NAD(P)H model 1-Aryl-1,4-dihydronicotinamides by cations 2-methyl-5-nitroisoquinolium, tropylium, and xanthylium in aqueous solution.

Cations 2-methyl-5-nitroisoquinolinium (IQ+), tropylium (T+), and xanthylium (Xn+) were treated by an NAD(P)H model 1-(p-substituted phenyl)-1.4-dihydronicotinamide series (1) in buffered aqueous solution to give the corresponding reduced products by accepting hydride. Effects of the 4-substituents of 1 on the reaction rates were investigated. Hammett's linear free energy relationship analysis on the three reactions of 1 provides the reaction constants of -0.48, -2.2, and -1.4 with IQ+, T+, and Xn+ as the hydride acceptors, respectively. Comparison of the present reactions with the reaction examples whose mechanisms are well-known, such as the reaction of 1 with a one-electron oxidant Fe(CN)6(-3), shows that the active site of 1 in the oxidation with IQ+ is at the 4-position on the dihydropyridine ring but that the active site of 1 in the oxidations with T+ and Xn+ is at the 1-position, which is in agreement with the results from the Brønsted-type linear analysis and the relation studies of the logarithm of the second-order rate constants with the oxidation potentials of the hydride donors. According to the dependence of the reaction mechanism on the active site of 1, a conclusion can be made that the reaction of 1 with IQ+ proceeds by direct one-step hydride transfer mechanism, but the reactions of 1 with T+ and Xn+ would take place via multistep hydride transfer mechanism initiated by one-electron transfer.

Cycloheptanes↗
PubMed2001

Molecular approaches for studying ascaridoid nematodes with zoonotic potential, with an emphasis on Toxocara species.

Species-specific identification of ascaridoid nematodes at any developmental stage is a prerequisite for detailed investigation of the life cycles, systematics and epidemiology of this important group, and is also crucial for the diagnosis of associated infections. The morphological identification of some species and/or their larval stages can, however, present considerable difficulty. Recently, PCR-based methods, using genetic markers in the internal transcribed spacers (ITS) of ribosomal DNA, have been shown to provide reliable alternatives to more traditional methods for the specific identification of nematodes. This article provides an account of recent research on the development of PCR-based methods (utilizing ITS sequences) for the specific identification of ascaridoid nematodes of zoonotic potential, for the diagnosis of infections, and for the analysis of genetic variation within and among individual nematodes and their populations. Prospects for using these diagnostic and analytical tools to investigate epidemiological and population genetic questions relating to ascaridoid parasites are also discussed.

Animals↗
PubMed2001

[The research on applications of diagnostic software in single photon emission computed tomography].

In this paper, the structure of software system, the principles of overlay programming and the running mechanism of the programs for the Single Photon Emission Computed Tomography(SPECT) made by French SOPHA MEDICAL Corp. are analyzed in detail. On this basis, a method of extending functions of the system is introduced too. All the results of the extension in software functions for organ volume determination and of the measurements for living animals have proved the correctness and reliability of the method.

Software↗