Biomedical subjects

X H Wei

Publications and source records attributed to X H Wei.

6 recordsLinked to original sources

PubMed2001

Genetic diversity among different clones of the gynogenetic silver crucian carp, Carassius auratus gibelio, revealed by transferrin and isozyme markers.

Genetic diversity among four clones (A, D, E, F) of gynogenetic silver crucian carp was studied using transferrin and isozymes in the blood as markers. Of the five proteins investigated, three (transferrin, esterase and superoxide dismutase) indicated polymorphism and eight polymorphic loci were detected. These loci were probably encoded by codominant alleles and their inheritance patterns were analyzed. Intraclonal homogeneity and interclonal heterogeneity were observed in these clones, which allowed us to infer the clonal nature and evolutionary relationship between them. Clonal diversity in this population of silver crucian carp in China was also compared with data reported from gynogenetic crucian carp in Germany.

Alleles↗

PubMed2001

[Application of an artificial neural network in the design of sustained-release dosage forms].

AIM: To use the artificial neural network (ANN) in Matlab 5.1 tool-boxes to predict the formulations of sustained-release tablets. METHODS: The solubilities of nine drugs and various ratios of HPMC: Dextrin for 63 tablet formulations were used as the ANN model input, and in vitro accumulation released at 6 sampling times were used as output. RESULTS: The ANN model was constructed by selecting the optimal number of iterations (25) and model structure in which there are one hidden layer and five hidden layer nodes. The optimized ANN model was used for prediction of formulation based on desired target in vitro dissolution-time profiles. ANN predicted profiles based on ANN predicted formulations were closely similar to the target profiles. CONCLUSION: The ANN could be used for predicting the dissolution profiles of sustained release dosage form and for the design of optimal formulation.

Delayed-Action Preparations↗

PubMed1990

Human leukocyte antigen F (HLA-F). An expressed HLA gene composed of a class I coding sequence linked to a novel transcribed repetitive element.

We describe here the isolation and sequencing of a previously uncharacterized HLA class I gene. This gene, HLA-5.4, is the third non-HLA-A,B,C gene characterized whose sequence shows it encodes an intact class I protein. RNase protection assays with a probe specific for this gene demonstrated its expression in B lymphoblastoid cell lines, in resting T cells, and skin cells, while no mRNA could be detected in the T cell line Molt 4. Consistent with a pattern of expression different from that of other class I genes, DNA sequence comparisons identified potential regulator motifs unique to HLA-5.4 and possibly essential for tissue-specific expression. Protein sequence analysis of human and murine class I antigens has identified 10 highly conserved residues believed to be involved in antigen binding. Five of these are altered in HLA-5.4, and of these, three are nonconservative. In addition, examination of the HLA-5.4 DNA sequence predicts that the cytoplasmic segment of this protein is shorter than that of the classical transplantation antigens. The 3' untranslated region of the HLA-5.4 gene contains one member of a previously undescribed multigene family consisting of at least 30 members. Northern analysis showed that several of these sequences were transcribed, and the most ubiquitous transcript, a 600-nucleotide polyadenylated mRNA, was found in all tissues and cells examined. This sequence is conserved in the mouse genome, where a similar number of copies were found, and one of these sequences was also transcribed, yielding a 600-nucleotide mRNA. The characterization of this unique HLA class I gene and the demonstration of its tissue-specific expression have prompted us to propose that HLA-5.4 be designated HLA-F.

Amino Acid Sequence↗

PubMed1990

Differential expression of HLA-E, HLA-F, and HLA-G transcripts in human tissue.

The data presented here demonstrate that the HLA-G class I gene is unique among the members of the human class I gene family in that its expression is restricted to extraembryonic tissues during gestation. Furthermore, the pattern of HLA-G expression in these tissues changes as gestation proceeds. During first trimester HLA-G is expressed within the placenta and not within the extravillous membrane. At term, the pattern of the HLA-G expression is reversed, extravillous membrane expresses HLA-G while placenta does not. Another non-HLA-A, -B, -C class I gene, HLA-E, is also expressed by extraembryonic tissues. Unlike HLA-G, HLA-E is expressed by both placenta and extravillous membrane at first trimester and at term. These results raise the intriguing possibility that the HLA-G-encoded molecule has a role in embryonic development and/or the fetal-maternal immune response.

Embryo, Mammalian↗

PubMed1989

[Measurement of the length of the adult esophagus using a fiberogastroscope: 104 cases].

From May 1979 to July 1985, the length of the esophagus in 104 patients with gastric disease was measured by a WX-C3 type fiberogastroscope. The result of measurement showed that the average length from the upper incisors to the cardia was 44.4 cm, and that from the upper end of the esophagus to the cardia was 28.0 cm. These measurement were respectively 4.4 cm and 3.0 cm longer than the traditional data (P less than 0.01). The difference in the length of the esophagus may be explained on the basis that measurement by rigid esophagoscope is in a straight line, while that by flexible fiberogastroscope is in a curvedline. Positive correlation between the length of the esophagus and the height of body was found in 91.3% of the cases. These data are of importance in the accurate localization of esophageal lesions.

Adult↗

PubMed1982

BCG in China.

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BCG Vaccine↗