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Biomedical subjects

L Y Wen

Publications and source records attributed to L Y Wen.

At least 19 recordsLinked to original sources
PubMed2001

Genetic analysis of the capsid region of astroviruses.

Eight serotypes of human astroviruses (HAstV-1 to HAstV-8) have been described. To date, the entire genomes of HAstV-1 and HAstV-2 as well as the ORF2 sequences of HAstV-1-6 and 8 have been reported. In this study, the ORF2 sequences of seventeen strains of HAstVs originating from different countries were determined, as well as the sequence ORF2 of one porcine astrovirus (PAstV) strain. Afterwards, comparison of the capsid protein precursors encoded by ORF2 of 46 strains of HAstVs, PAstV, and feline astrovirus (FAstV) was carried out. A phylogenetic tree showed eight genogroups of HAstVs that corresponded exactly to the serotypes. HAstV-3 and 7 were the most closely related, whereas HAstVs, FAstV, and PAstV segregated from each other. Compared to a PAstV, a FAstV is closer to HAstVs. Furthermore, the capsid protein precursors were divided into four regions (after amino acid residues 424, 688, and 776, respectively) based on sequence identity. Region I was the most conserved, and FAstV was very close in identity to HAstVs. Two amino acid motifs in region I were predicted to contain the common antigenic epitopes. Region II was relatively variable. Deletions and insertions were characteristic of region III, and region IV was relatively conserved. To our knowledge, this is the first comparative sequence analysis of the capsid protein precursors of eight serotypes of HAstVs as well as two animal astroviruses (FAstV and PAstV).

Amino Acid Motifs↗
PubMed2001

[Studies on immunological reaction of the antiserum of recombinant secreted protein from Ancylostoma caninum].

OBJECTIVE: To analyze the immunological reaction of the antiserum of recombinant secreted protein from Ancylostoma caninum with antigens of various species hookworms at different developmental stages. METHODS: SDS-PAGE and ELIB technique were employed in the study. RESULTS AND CONCLUSION: The protein component of Ac-rAsp-1 was 45 kDa, its immune serum can recognize the antigens of Ac-L3 and Ac-rAsp-1 protein, but not react to the antigens of Ad-A, Ad-L3, Na-A, Ac-A, Nb-A and Ac-rAsp-2 protein. The protein component of Ac-rAsp-2 was 24 kDa, its immune serum can recognize the antigens of Ad-A, Ad-L3, Na-A, Ac-A, Ac-L3 and Ac-rAsp-2 protein, but not react to the antigens of Nb-A and Ac-rAsp-1 protein.

Ancylostoma↗
PubMed2000

[Studies on separation and identification of Rhizoma coptidis brugs based on microemulsion thin-layer chromatography].

OBJECTIVE: To investigate the use of microemulsion TLC for the separation and identification of Rhizoma Coptidis drugs. METHOD: Thirteen Rhizoma Coptidis drugs were separated and identified with six kinds of SDS/n-C4H9OH/n-C7H16/H2O microemulsions as mobile phase on polyamide film. Effects of microemulsions on separation were investigated. RESULTS: The best mobile phase was the O/W microemulsion(containing 75% water). Compared with general mobile phases, the separation and detection could be improved and the test conditions were more tolerant. CONCLUSION: This new method is simple, accurate and efficient for the separation and identification of Rhizoma Coptidis drugs.

Berberine↗
PubMed2000

[Longitudinal observation on the control of intestinal helminthiasis].

OBJECTIVE: To search suitable measure for rapid control intestinal helminthiasis and long-term strengthen efficacy. METHODS: The treatment was taken in egg-positive population of intestinal helminthiasis in 1986-1988. The treatment was carried out only in the selected population in 1989-1992. No measure was taken in 1993-2000. RESULTS: (1) The prevalence rate of hookworm, Ascaris and Trichuris decreased to 3.2%, 37.3% and 3.5% respectively after administration of albendazole twice a year for 3 years. (2) The prevalence rate of hookworm continued to decrease to 0.5% after treatment on selected population. (3) The prevalence rate and the intensity of hookworm has been less than 1% and 10/LPG for 8 years. No hookworm larvae had been isolated from the soil. CONCLUSION: The hookworm transmission was effectively controlled in the study site.

Albendazole↗
PubMed1994

[Discussion of the treatment of Formocresol (FC-ZOE) and Glutaradehyde (GA-ZOE) for pulpitis and periapical disease on primary teeth]

This study was discussed of the treatment of FC-ZOE and GA-ZOE for pulpitis and periapical disease on primary teeth.The post-operation observation was from 18 to 24 months.The result demostrated that the treatment for pulpitis is good,but for periapical disease is not satisfying. Ga-ZOE is effective as a fixing agent of devitalization for gangrenous root canal,and it was ineffective as an aseptic agent for infective root canal.FC-ZOE was disadvantage as a filling agent of root canal.

Journal Article↗
PubMed1993

[Application of low temperature demineralization and frozen section technique in the immunochemistry study of dental pulp]

The purpose of the study was to explore experiment method by means of periodate-lysine-parafoemaldehyde fixative,EDTA low temperature demineralization and frozen section technique.The results showed the technique suit either completely to immunohistochemical study of the pulp matrix and of the cell surface expression that was weaker antigenicity,or to enzyme histochemical staining of the dental pulp.

Journal Article↗
PubMed1992

[Clinical observation on efficacy of ivermectin in the treatment of intestinal nematode infections].

A total of 166 cases were divided into 3 groups: group A comprised 55, group B 54 and group C 57 cases. Group A received ivermectin 0.1 mg/kg orally at a single dose, the cure rates were 100%, 3.8% and 50% for ascaris, hookworm and trichuris, infections respectively: group B received ivermectin 0.2 mg/kg orally at a single dose, the corresponding cure rates were 95.5%, 11.8% and 76.5% respectively; group C received pyrantel pamoate 10 mg/kg orally at a single dose, the corresponding cure rates were 95.5%, 29.6% and 31.6% respectively. Although the cure rates were very low for hookworm infection in both group A and B, however, a number of adult worms of Ancylostoma duodenale and Necator americanus were expelled aster medication; It indicates that ivermectin has some effects on these two species of human hookworm. Side effects were mild and transient in all groups.

Adolescent↗
PubMed1991

Studies on the control of hookworm and other soil-transmitted helminthiases in farmers in Zhejiang Province, China.

Different periodic selective chemotherapeutic schemes were used to control hookworm and other soil-transmitted helminthiases in eight villages in five counties in Zhejiang Province, China, 1985-1988. The results showed that the prevalence rates of hookworm, ascariasis, and trichuriasis decreased from 35.0-74.4%, 47.0-.76% and 22.9-47.5% to 3.2-15.8%, 9.9-47.8%, and 3.5-31.2%, respectively, using pyrantel pamoate (10 mg/kg for 1-2 days) or albendazole (400 mg for 1-2 days, once or twice a year for 2-3 years). The eggs per gram of feces of hookworm and Trichuris trichiura also dropped markedly after control. Moreover, the mean hemoglobin levels of sampled populations increased after several treatments. The authors recommend periodic selective chemotherapy as the main method to control soil-transmitted helminthiases, especially hookworm infections.

Agriculture↗
PubMed1991

Vernal keratoconjunctivitis with shield ulcer--a case report.

This 9-year-old boy had a three-year history of vernal keratoconjunctivitis. A shield ulcer developed in the superior part of the cornea. The shield ulcer is a rare manifestation of the disease. Although the cause of shield ulcer is unknown, the association of shield ulcer with large papillae suggests a mechanical cause. The symptoms of itching and mucous discharge were relieved after medications with topical steroid and cromolyn sodium, but the large shield ulcer was persistent. The vernal ulcer was treated with a 72 hours collagen shield. The ulcer healed rapidly within 5 days, leaving a corneal opacity about the level of Bowman's layer.

Child↗
PubMed1990

The study of ocular hypotensive effect of 6-hydroxyethoxy-2-benzothiazole sulfonamide: a topical carbonic anhydrase inhibitor.

A newly synthesized topical carbonic anhydrase inhibitor, 6-hydroxyethoxy-2-benzothiazole sulfonamide (6-HS), was administered systemically and topically to alpha-chymotrypsin-induced glaucoma rabbits to evaluate its ocular hypotensive effect. A significant IOP lowering effect was observed after topical application of 50 microL of 3% 6-HS gel, but a dose of 50 microL of 3% 6-HS suspension failed to reduce IOP. The maximal magnitude of reduced IOP after topical gel instillation was 24.4%, very close to the result obtained following intravenous injection of 6 mg/kg of 6-HS (23.3%). However, the blood levels of 6-HS after topical instillation with 3% 6-HS gel was much lower than that following 6 mg/kg of 6-HS injected intravenously (less than 5%). Since a lower dose of 6-HS (1 mg/Kg) administered intravenously did not cause a significant drop in IOP, it is reasonable to deduct that the ocular hypotensive effect of 6-HS applied topically can then be attributed to the inhibition of intraocular carbonic anhydrase activity. It was also noted that a larger dose of intravenous administration of 6-HS (20 mg/Kg) had a more profound IOP and blood pressure reducing effect with moderate metabolic acidosis.

Animals↗
PubMed1988

Amino acid concentrations in serum and aqueous humor from subjects with extreme myopia or senile cataract.

With an amino acid analyzer, we measured amino acids and related compounds in serum and aqueous humor from normal Chinese and some patients with extreme myopia or senile cataracts. Forty peaks were well resolved, and their areas were used to quantify each compound. In the myopic patients, glutamate, alpha-aminoadipate, and methionine concentrations in serum were 10-fold those in the normal subjects. Values for most of the other amino acids and related compounds were also higher in myopic patients' sera. In the cataract patients, concentrations of most of these compounds were lower in serum but higher in aqueous humor than for the normal subjects. Tryptophan was present in significant amounts in sera from the normal subjects, but was not detectable in the senile-cataract patients. The ratio of amino acid concentration in aqueous humor to that in the serum (Ch/Cs) was higher in the cataract patients than in normal subjects for almost all of the compounds we measured.

Amino Acids↗
PubMed1986

Serum ornithine levels in some ocular disorders.

The fact that Chinese have a high occurrence of myopia and the toxicity of ornithine to retinal epithelial cells raised our interest to investigate the serum ornithine levels in high myopic patients. After analyzing several hundred patients, no significant difference in the serum ornithine level was found between Chinese and non-Chinese. However, patients with various ocular disorders did show higher ornithine levels. Serum citrulline levels in myobes and non-Chinese groups were decreased. The significance of these findings needs further investigation.

Citrulline↗