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Biomedical subjects

B S Chen

Publications and source records attributed to B S Chen.

At least 37 records · Page 2Linked to original sources
PubMed1994

Polymorphisms of apolipoprotein B gene in relation to coronary heart disease in Chinese Han nationality.

Two polymorphic sites of apolipoprotein B (apoB) gene, XbaI and EcoRI, were examined in 80 patients with documented coronary heart disease (CHD) and 60 healthy individuals selected from a population of Chinese Han nationality. Allele frequencies at these sites were compared between the patients and controls and their impact on lipid metabolism was also investigated. The frequency of X+ allele (presence of XbaI cutting site) in CHD patients was 0.10, which was significantly higher than 0.01 in controls (P < 0.001). The same trend was detected for frequency of E-allele (lack of EcoRI cutting site) when it was compared between CHD patients and controls (0.11 vs 0.05), the difference was not statistically significant (P < 0.1, > 0.05). There was no relationship between XbaI RFLP and EcoRI RFLP. In the CHD patients, X+ allele was associated with the lower levels of HDL-C and apoAI when compared with X- allele, while no associations were found of X+ allele with other lipid parameters. On the contrary, the EcoRI polymorphism had no significant influence on plasma lipid and lipoprotein levels. Therefore, it was suggested that genetic variation at XbaI site of apoB gene might contribute to the determination of plasma HDL-C level and development of CHD in people among Chinese Han nationality.

Adult↗
PubMed1994

[Apolipoprotein B signal peptide insertion/deletion polymorphism in Chinese patients with coronary heart disease].

Insertion/deletion (Ins/Del) polymorphism of the apo B gene encoding signal peptide and its relation to coronary heart disease (CHD) and lipid trait were studied in 103 patients with CHD and 100 healthy individuals from Chinese Han nationality. The frequency of rare Del allele was 0.259, which was significantly lower than 0.34 in Caucasians (France), but higher than 0.16 in South Asian descents in UK. When the frequency distribution of the Ins/Del alleles was compared between CHD group and control group, the frequency of rare Del allele in the patient group was not apparently different from that in the control group (0.282 vs. 0.235, P > 0.05). As for the impact of the Ins/Del genotype on levels of lipid and apolipoprotein, the patients with at least one Del allele had significantly lower HDL-C level compared with those with only Ins allele in the CHD group (P < 0.01). Levels of other lipid parameters in each group were not obviously associated with the Ins/Del genotype. It is suggested that the Ins/Del polymorphism of the apo B signal peptide might be involved in lipid metabolism by an unidentified mechanism in some ethnic population. PCR is a useful method for distinguishing Ins/Del polymorphism of the apo B signal peptide.

Alleles↗
PubMed1993

[A comparative study of masticatory efficiency between partial denture wearers having one remaining tooth and complete denture wears]

Masticatory efficiency is one of the important indexes of judging masticatory function after dentures restored.The aim of this study was to measure and analyze masticatory efficiency of partial dentur wearers having one tooth left and complete denture wearers,by using a method of measuring msticatory crushed granules.The results showed that the crushed granules for partial denture wearers with one remaining tooth were smaller than that for complete ones.Therefore,partial dentures with a few remaining teeth were better than complete ones on effects.

Journal Article↗
PubMed1993

[The diagnosis and the treatment on lingual thyroid]

Lingual thyroid is a rare example of ectopic thyroid.This paper reported three cases of lingual thyroid(all female,aged between 16 and 61 years) were discussed with diagnosis and treatment.A transoral excision using the median total glossotomy and precervical excision was performed through a transsuprahyoid approach.Postoperative complications is not developed.The approach above mention is better than that of median labiomandibular glossotomy.

Journal Article↗
PubMed1993

[Comparison of food specific IgE antibody test (RAST) and skin tests in children with atopic dermatitis].

Thirty children with atopic dermatitis were enrolled in our study to evaluate the food specific IgE antibody assay (RAST) and skin tests as a screening test for food hypersensitivity. Our results showed that eight food antigens (fish, shrimp, crab, soybean, milk, egg-white, peanut, wheat) frequently elicited positive hypersensitivity reactions. Twenty-four patients had at least a positive skin reaction to one of the foods tested. Of the 240 skin tests, 30% (72/240) yield positive reactions. Eighteen patients had at least a positive RAST reaction to one of the foods tested, 20.9% (50/240) yield positive reaction. The agreement between skin test and RAST was 79.6%. Crab and shrimp accounted for most frequent positive reaction in both tests. The skin tests produced more positive results in skin testing than RAST, but gave a higher frequency of false positive results. The diagnosis of food allergy may be suspected from the medical history or by food specific IgE antibodies together with skin test as a screening test. Furthermore, the double blind placebo controlled food challenge should be considered as standard for clinical investigations.

Adolescent↗
PubMed1992

[Metabolism of serum lipoprotein in hypothyroidism].

The changes of serum lipids concentrations in 15 patients with primary hypothyroidism were studied. 9 euthyroid persons in the similar age group with patients were selected as a control group. The serum levels of total and LDL cholesterol, TG, ApoAI, ApoB and ApoCII in patients before treatment were all higher than those of the control group. They decreased to normal level after treatment. The mean values of total cholesterol decreased from 6.7 mmol/L to 4.1 mmol/L, TG decreased from 2.5 mmol/L to 1.0 mmol/L, LDI-ch from 3.9 mmol/L to 2.4 mmol/L, ApoAI from 1.9 g/L, to 1.3g/L, ApoB from 1.2 g/L to 0.7 g/L and ApoCII decreased from 6.9 mg/dl to 3.9 mg/dl. There were no differences of HDI-ch level between patients before treatment and normal controls, HDI-ch level of patients only slightly decreased after treatment. Soon after the thyroid hormone treatment, all parameters of serum lipids, not including HDI-ch, were improved, as TT, level became normal, although the levels of TT4 was still not reached to normal level.

Adult↗
PubMed1992

Radionuclide hysterosalpingography with technetium-99m-pertechnetate: application and radiation dose to the ovaries.

Although radionuclide hysterosalpingography (RNHSG) has been suggested as an efficient procedure for assessing function of fallopian tubes, the radiation dose to the ovaries was addressed as an important issue to be taken into consideration. We describe a modified method of RNHSG, calculating the radiation dose to the ovaries. A small dose of approximately 18.5 MBq (0.5 mCi) of [99mTc]pertechnetate was administered directly into the uterine cavity without overpressure. The accuracy of the method was 84.5% as compared with the contrast hysterosalpingography. The estimated average dose to the ovaries was 0.057 mGy/MBq (0.21 rad/mCi) or 1.08 mGy (108 mrad) per study. RNHSG is an accurate method for functional study of fallopian tube patency with low radiation dose.

Adult↗
PubMed1991

Long term and large-scale cultivation of human hepatoma Hep G2 cells in hollow fiber bioreactor. Cultivation of human hepatoma Hep G2 in hollow fiber bioreactor.

Long-term and large scale cultivation of an anchorage-dependent cell line using an industrial scale hollow fiber perfusion bioreactor is described. Hep G2 cells (a human hepatoma cell line) were cultivated in an Acusyst-P (Endotronic) with a total fiber surface area of 7.2 m2 6 x 1.2m2) to produce Hep G2 crude conditioned medium (CCM). Pretreatment of the cellulose acetate hollow fibers with collagen enhances the attachment of the anchorage-dependent cells. We have succeeded in growing the Hep G2 cells in an antibiotics- and serum-free IMDM medium, supplemented with 50 micrograms/ml of Hep G2 CCM protein at inoculation. The Hep G2 cells replicate and secrete CCM protein in quantities comparable to those produced in DMEM containing 10% fetal calf serum (FCS). The highest CCM protein productivity during the 80-day cultivation was 1.1 g/day with a total of 30 g of protein accumulated. Hep G2 CCM (20-40 micrograms protein/ml) was comparable to or even better than 10% FCS in supporting the growth of Molt-4 (a human T leukemia cell line) and FO (a mouse myeloma cell line) cells in vitro. The availability of this large amount of Hep G2 CCM will aid the further purification and characterization of growth factor(s) which could be used as serum substituents.

Carcinoma, Hepatocellular↗
PubMed1990

[Large-scale production of monoclonal antibodies using hollow fiber bioreactor].

Development of large-scale monoclonal antibody production using industrial scale hollow fiber bioreactor is described. Hybridoma cell lines H505AC and A306AA were cultivated in the hollow fiber perfusion bioreactor with a total fiber surface area of 7.2 m2 (6 x 1.2 m2) to produce anti-hepatitis B surface antigen (anti-HBsAg) monoclonal antibody IgM and anti-alpha-fetal protein (anti-AFP) monoclonal antibody IgG. The highest anti-HBsAg IgM productivity obtained during 49 days cultivation of H505AC was 0.135 g/day and the total accumulated IgM was 1.90 g. Results from the cultivation of A306AA in the hollow fiber module for 23 days showed the highest anti-AFP IgG productivity and the total accumulated IgG were 0.672 g/day and 7.21 g, respectively.

Animals↗
PubMed1990

The differences of serum cholesterol and lipoproteins in animals susceptible and nonsusceptible to atherosclerosis.

The differences of serum lipid and lipoprotein (LP, profiles of animals susceptible (rabbit) and nonsusceptible (Beijing duck) to atherosclerosis as well as the distribution of apolipoprotein (apo) A-I and its catabolism in vivo were studied. Eight items, i.e. total cholesterol (TC), high density lipoprotein (HDL) cholesterol, triglyceride, percentage of alpha-LP and beta-LP, beta-LP concentration, lecithin cholesterol acyl transferase (LCAT), and agarose and polyacrylamide gel electrophoresis of both species were assayed before and after feeding a high fat, high cholesterol diet. Results indicate that the exogenous cholesterol consumed by Beijing ducks was carried and transported by HDL, while that in rabbits was transported by low density lipoprotein (LDL). The biological half lives of apo A-I in serum and in HDL were 41.1 +/- 2.4 and 42.8 +/- 1.7 h respectively, and its distribution in different organs was in the order of liver greater than kidney greater than spleen greater than lung greater than heart greater than intestine greater than muscles greater than aorta. These results show that the liver is the major organ for metabolizing HDL apo A-I, and the kidney is also important. The results also imply that in Beijing ducks the cholesterol carried by HDL may be catabolized through apo A-I receptors in the liver and kidney. The differences in cholesterol binding and in lipoprotein and apolipoprotein metabolism of the two species provide important clues for the elucidation of the pathogenesis of atherosclerosis.

Animals↗
PubMed1990

[Distribution of apoE phenotypes and frequencies of apoE alleles in Mongolian population].

Distribution of apoE3/3, E3/4 and E2/3 were 88.2%, 9.7% and 2.2%, respectively, in a Mongolian population. No apoE2/2, E2/4 or E4/4 phenotypes were found in this study. The population of apo E3/3 and frequency of epsilon 3 in this Mongolian population were significantly higher than those of Western populations and the Han nationality of China. The above results indicated that apoE phenotypes are closely related to lipid levels. The cholesterol levels of individuals with apoE3/3 phenotype were much lower than those of individuals with apoE2/3 (P less than 0.01) and higher than those of individuals with apoE3/4 (P less than 0.05). The levels of apoA-1 of individuals with apoE3/3 were much lower than those of individuals with apoE2/3 (P less than 0.01), but no difference was found between apoE3/3 and apoE3/4 phenotypes (P greater than 0.05).

Adolescent↗
PubMed1989

Comparison of RNAs and polypeptides of infectious pancreatic necrosis virus isolates from eel and rainbow trout.

Thirteen isolates of infectious pancreatic necrosis virus (IPNV) from eel and rainbow trout in Taiwan were compared with the selected serotypes AB, SP and VR-299 by PAGE analysis of their RNA genomes and early polypeptides. All the IPNV isolates from eels (1984 to 1986) from Lu Kang and Ping Tung, and from rainbow trout eggs and fry from Dan Sway (1985 to 1986) were most closely related to the AB serotype. However four rainbow trout isolates from Dan Sway (1984) had a similar RNA pattern to that of VR-299, whereas their early polypeptides were different, showing evidence of some mutations. Both RNA and polypeptide PAGE patterns were used to distinguish the isolates from known selected IPNV strains showing that this approach can be used for epizootiological studies.

Anguilla↗
PubMed1989

[Plasma prostaglandins E, E2 and F2a in nasopharyngeal carcinoma (NPC)].

The levels of prostaglandins E, E2 and F2a (PGE, PGE2, PGF2a) in plasma of NPC patients, patients with other tumors and normal individuals were monitored by radioimmunoassay. The results showed that PGE and PGE2 levels in the plasma of NPC and other cancer patients were significantly higher but the PGF2a/PGE2 ratio was obviously lower than that of the normal (P less than 0.05). But there were not much changes in the PGF2a levels (P greater than 0.05). However, no difference was found between the PG8 levels of the NPC and the other cancer patients (P greater than 0.05). Neither were there any significant changes in the PGE2 and PGF2a plasma levels and ratio of PGF2a/PGE2 in 26 NPC patients staged according to TNM classification. It is indicated that there is a relation between PGE, PGE2 and nasopharyngeal carcinoma.

Adult↗
PubMed1987

Rabbit apolipoprotein A-I mRNA and gene. Evidence that rabbit apolipoprotein A-I is synthesized in the intestine but not in the liver.

In order to study the tissue-specific expression of rabbit apolipoprotein (apo) A-I, a 923-base-pair clone, pRBA-502, complementary to rabbit apo A-I mRNA was identified from a rabbit intestinal cDNA library by hybrid-select translation and immunoprecipitation methods. Northern blot and dot-blot hybridization, utilizing 32P-labeled pRBA-502, revealed that the rabbit apo A-I gene is expressed in the intestine, not in the liver and that rabbit apo A-I mRNA is about 950 nucleotides in length. The entire nucleotide sequence of pRBA-502 has been determined and the complete amino acid sequence of the corresponding apo A-I has been deduced. The mRNA codes for a protein comprising 265 amino acids. Amino acids 1-18 and 19-24 of the primary translation product represent the presegment and prosegment, respectively, of apo A-I. Matured rabbit apo A-I contains 241 amino acids and has a molecular mass of 27612 Da. Using pRBA-502 as a probe, a 15.5-kb genomic fragment, which contains the entire apo A-I gene, was isolated from a rabbit liver genomic library. Sequence analysis of the gene shows that the 200 base pairs of the 5' upstream flanking region of the rabbit and human apo A-I genes showed 78% sequence homology. Like the human apo A-I gene, the rabbit apo A-I gene is interrupted by three intervening sequences. Except for two nucleotides in the fourth exon, the coding sequence of the rabbit liver apo A-I gene is identical to that of pRBA-502. Our data showed that the lack of expression of apo A-I gene in rabbit liver is not due to the alternation of rabbit liver apo A-I gene sequence and suggest that the expression of apo A-I gene in rabbit liver is regulated by a trans-acting regulating element(s).

Amino Acid Sequence↗
PubMed1987

Isolation and characterization of a full-length rabbit apolipoprotein E cDNA.

In order to study the primary structure of rabbit apolipoprotein (apo) E and the regulation of levels of liver apo E mRNA by dietary cholesterol, we have cloned and sequenced a full length rabbit apo E cDNA. DNA sequence analyses suggests that rabbit apo E is synthesized with an additional 18 amino acids as the prepeptide. The mature rabbit apo E contains 293 amino acids with a calculated molecular weight of 33,528. It has a 76% amino acid sequence homology with human apo E. Northern blot analyses showed that rabbit apo E mRNA is about 1200 nucleotides in length. Using mRNA dot blot analyses, we found that dietary cholesterol has no effect on the level of apo E mRNA in rabbit liver. We conclude that the elevated levels of plasma apo E in rabbits fed a cholesterol-rich diet is not a result of an increase of levels of apo E mRNA in the liver.

Amino Acid Sequence↗