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M Y Xia

Publications and source records attributed to M Y Xia.

At least 19 recordsLinked to original sources
PubMed2001

[Study on molecular phylogeny of Schistosoma sinensium based on nuclear ribosomal DNA].

OBJECTIVE: To determine the phylogenetic relationships between Schistosoma sinensium and other Schistosomatid species using DNA sequence data. Two segments of the nuclear rDNA repeat, the second internal spacer (ITS2) and large subunit (LSU/12S) were selected for sequencing. METHODS: Adult worms stored in 100% methanol were washed 3 times with 0.1 x TE (pH8.0) and the genomic DNA was extracted by the GNT-K method. The target regions were amplified by PCR using specific primers. The PCR products were purified before ligation into the plasmid pT-adv (Clontech). Recombinant plasmids were amplified in E. coli (strain TOP10), extracted and purified using routine methods and then sequenced using M13 primers (F/R) on a Licor long-read auto-sequencer. Sequences of related schistosomes were retrieved from GenBank and aligned with our data in the sequence editor ESEE. Gene trees were constructed in PHYLIP (Version 3.6 alpha July, 2,000) and MEGA (version 2.0 beta build 3) using both Maximum Parsimony and Neighbor-Joining methods. For parsimony analysis, all characters were treated as unordered and with equal weights. At least 3,000 cycles of bootstrapping were carried out. For analysis in MEGA, all gap columns were deleted. Schistosomatium douthitti and Trichobilharzia were used as outgroups. RESULTS: The ITS2 and LSU sequences of Schistosoma sinensium were obtained. The ITS2 sequence of Trichobilharzia sp. was reported here for the first time. CONCLUSION: The phylogenetic trees from these data of nuclear rDNA suggested that S. sinensium belongs to the Asian schistosome group. And this species might be an ancient member in the Asian clade.

Animals↗
PubMed2001

[Preliminary study on cytochrome C oxidase 1 gene of Oncomelania hupensis from Miao River area in Hubei province].

OBJECTIVE: To study the mitochondrial cytochrome C oxidase 1(CO1) gene of Oncomelania snails from Miao River area in Hubei Province. METHODS: Oncomelania snails were collected from Miao River area, including upstream and downstream. Genomic DNA was extracted from the tissue of the snail. PCR was used to amplify a fragment of the CO1 gene. Sequences of the CO1 fragment were determined directly from the purified PCR products by an automated sequencer. Sequences for each individual were assembled and edited using ESEE 3.0 s. A distance matrix was computed using program DNADISt of PHYLIP(3.57). Unrooted maximum likelihood trees were calculated from program FITCH. RESULTS: The amplified CO1 gene of the snail was a fragment of 638 bp in length. Sequence analysis showed that the accumulated variable sites were significant different between upstream and downstream populations, being 29 and 46, respectively. From the number of variable sites in the gene, snails in this area were roughly separated into two groups. Each of them was a mixture of both upstream and downstream snails. Same haplotypes were confirmed to be present among the collected sites along the river. From the distance matrix of sequence divergence, the population upstream vs downstream differed by 0.0221 +/- 0.0105. CONCLUSION: There were more variation in downstream population than that in upstream. Gene flow was identified in these populations. The phylogenetic trees suggest the existence of two groups, but all of them belong to 0. h. hupensis.

Animals↗
PubMed1996

Ultrastructure and human papillomavirus DNA in papillomatosis of external auditory canal.

BACKGROUND: A viral etiology has been suspected in papillomatosis of the external auditory canal (PEAC), but virus particles have not been detected so far, although they are easily demonstrable in skin warts. The purpose of the study was to solve this discrepancy by the use of polymerase chain reaction (PCR). MATERIALS AND METHODS: Specimens from the external auditory canal of 14 patients with PEAC, but no human papilloma virus infection of the genital areas, were examined histologically by light and electron microscopy, as well as by PCR to detect viral DNA. RESULTS: Histologically, papillomatosis was present in all specimens. Vacuolated cells were found in the upper part of the stratum malpighii in five cases. On electron microscopy, the numbers of perichromatin and interchromatin granules were increased, but no viral granules were observed. In all specimens, DNA of HPV 6 was detected using PCR, but there was no evidence of DNA of other HPV. CONCLUSIONS: Papilloma of the external auditory canal is produced by infection with HPV 6.

Adult↗
PubMed1995

Detection with the polymerase chain reaction of human papillomavirus DNA in condylomata acuminata treated with CO2 laser and microwave.

BACKGROUND: The recurrence rates of condyloma acuminata are high. The reasons for the relatively high relapse rates with different treatments are unknown. METHODS: Twelve specimens of condylomata acuminata of the vulva were excised from 12 patients and divided into three parts. One part was untreated, the second and the third parts were treated with CO2 laser and microwave, respectively. DNA was then extracted from tissue by proteolytic digestion and amplified by the polymerase chain reaction. Dot blots were performed with the use of radiolabeled consensus and human papilloma virus (HPV) type-specific probes. RESULTS: HPV DNA was amplified in 100% of untreated specimens (6-HPV 6; 6-HPV 11), and in 83.3% and 50% of specimens treated with CO2 laser and microwave, respectively. There was a significant difference in detection between untreated and microwave-treated specimens (chi 2 = 4.18, P < 0.05). CONCLUSION: Microwave damages HPV DNA more effectively than CO2 laser.

Carbon Dioxide↗
PubMed1994

Hirsutoid papillomas of vulvae: absences of human papilloma virus (HPV) DNA by the polymerase chain reaction.

We have analyzed the specimens from 16 women with hirsutoid papillomas of the vulvae for the presence of HPV DNA using the polymerase chain reaction. The subjects' ages ranged from 27 to 43 years. In all cases, smooth or filiform papules were symmetrically located on the inner surface of both labia minora. Histologically, the lesions consist of acanthosis or papillomatosis without koilocytes and mitotic activity. Eight of 16 specimens were studied by transmission electron microscopy (TEM). No HPV granules were found in the nuclei of keratinocytes. HPV DNA could not be detected in all specimens. Positive controls were present in each assay. These results suggest that the papules of hirsutoid papillomas of the vulvae are unrelated to HPV. Chronic irritants and inflammation may play an important role in pathogenesis.

Adult↗
PubMed1993

Trichonodosis.

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Adult↗
PubMed1991

Penetration and migration routes of Schistosoma japonicum miracidia in the snail Oncomelania hupensis.

The routes of penetration and the strategies of invasion of Schistosoma japonicum miracidia in the snail vector Oncomelania hupensis were observed in a histological study. In all species of the genus Schistosoma, it is usually assumed that the miracidia achieve penetration through the tegument. Our results showed that at least 57% of S. japonicum miracidia penetrated the snail by natural openings (branchial cavity, mouth and rectum). Throughout the invasion phase, the larvae were observed in all the tissues and organs with the exception of the genital gland. The spatial distribution of parasites in the snail revealed that the migration towards the visceral organs such as the kidney, heart and sinuses (which are the most usual microhabitats of the mother sporocysts of S. japonicum) appeared to take place via the circulatory system. Using natural openings as routes for penetration probably provides a selective advantage in a host-parasite system in which the target mollusc is amphibious: we presume that the miracidia inside these natural openings are protected against desiccation when the snail leaves the water, and that they can subsequently invade the tissues.

Animals↗
PubMed1991

[Demonstration of replication of daughter sporocysts in the natural development of Schistosoma japonicum].

The participation of replicating sporocysts in the intramolluscal development of Schistosoma japonicum within its snail host Oncomelania hupensis is demonstrated by histological studies. Replicating sporocysts were observed in snails maintained under both standard and hibernation conditions. The demographic and epidemiological importance of the replication process within schistosomes is discussed comparatively.

Animals↗
PubMed1990

Hair casts: a clinical and electron microscopic study.

Hair casts were seen in 22 girls ranging in age from 4 to 13 years. They were localized to the frontal, vertex, and temporal areas. The number of affected hairs varied from one-tenth to one-third. Twenty of the 22 girls styled their hair in ponytails or pigtails. Compound root sheath casts were present in six of nine patients using 1% 4-dimethylaminocinamaldehyde stain. A mass of large polymorphous scales and solitary or clumped spores was seen on the surface of hair casts using scanning and transmission electron microscopy. Energy-dispersive x-ray microanalysis showed that elements of silicon, aluminum, and molybdenum were uniquely present in hair casts. We assume that tightly drawn braids, by causing local circulatory disturbances and inflammation of the scalp, may be one etiologic factor in the disorder.

Adolescent↗
PubMed1986

[Shedding pattern of Schistosoma japonicum cercariae from mainland China by Oncomelania hupensis].

The release of Schistosoma japonicum cercariae from the People's Republic of China shedded by Oncomelania hupensis was observed hourly under laboratory conditions: LD 9 - 15, T degrees = 25 degrees C. Daily periodicity of emergence was recognized during the light period. Peaks emergence occurs between 2 and 5 p.m. Results are compared with other geographical strains of S. japonicum.

Animals↗
PubMed1986

[Study of schistosome-mollusk vector compatibility by the technic of microsurgical transplantation of sporocysts in two Schistosoma japonicum-Oncomelania hupensis combinations originating in mainland China].

The Schistosoma-Mollusc compatibility was tested in two Schistosoma japonicum-Oncomelania hupensis combinations originated from mainland China. The first combination is a combination maintained for more than 30 years in laboratory, the second consisted of a laboratory strain of S. japonicum and a strain of O. h. hupensis taken in the field (Jiangxi province). The fully absence of sporocyst throwing out and hemocyte infiltration 24 h. after transplantation suggest a perfect compatibility of the two combinations. Concerning the test carried out on a natural population of O. h. hupensis, the result obtained might reveal that the schistosomiasis transmission area from Jiangxi province represents focuses with high risk.

Animals↗