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Biomedical subjects

Y Sun

Publications and source records attributed to Y Sun.

At least 829 records · Page 46Linked to original sources
PubMed1995

[Treatment of burned joints and functional recovery].

From 1979 to 1990, 33 operations on 29 patients with joint burn were performed by early debridement and primary repair with myocutaneous flaps. As a result, 29 wounds healed by first intention. The healing rate of early operations performed within 10 days postburn was 95.2%, and that of the late operations delayed more than 10 days post-burn was only 75.0%. 31 among 33 joints (93.9%) recovered full range of movement, while the other 2 joints ended with only slight limitation of function. We suggest that the early debridement and primary repair with myocutaneous flap is the best choice for treatment of burned bone and joints.

Adolescent↗
PubMed1995

[An eight-year prospective study on 163 cases of hepatitis C].

To explore the characteristics of hepatitis C in China, one hundred and sixty three cases of hepatitis C were followed for 8 years. The rates of abnormal alanine aminotransferase (ALT) were 100%, 73%, 57%, 37% and 28% in less than one, 1, 2, 5 and 8 years after the onset respectively. Abnormality of ALT might be persistent or fluctuating, and the latter type accounted for about 1/3 to 1/2 of the cases. The positive rates of anti-hepatitis C virus (HCV) were 56%, 93%, 94%, 96%, 97%, 93% and 83% in less than two, 2-6, 7-12 months and 1, 2, 5 and 8 years after the onset respectively. Negative conversion of anti-HCV was found only in a few patients whose ALT had returned to normal level and the rates of negative conversion for them were 10%, 8%, 16%, and 22% in 1, 2, 5 and 8 years after the onset. Positive rate of HCV-RNA, detected with nested PCR 8 years after the onset was 84% for patients who still showed positive anti-HCV and there was no significant difference between patients with abnormal (80%) and normal ALT (85%) levels. Genotype II accounted for 93% of the cases. No patient developed hepatocellular carcinoma or decompensated cirrhosis after a follow-up of eight years.

Adolescent↗
PubMed1995

[Mechanism of resistance to mitomycin C in a human bladder cancer cell line].

This study was undertaken to determine the mechanism of resistance of a human bladder cancer cell line SCaBER to mitomycin C (MMC). The IC50 value for MMC in SCaBER cells was higher by 2.7 fold by 1-h drug exposure colony formation assay as compared to another bladder cancer cell line J82. NADPH cytochrome P450 reductase and DT-diaphorase activities were significantly lower in SCaBER cells as compared to those of J82 suggesting that relatively resistance of SCaBER cells to MMC may be due to inefficient drug activation. Further support for this conclusion derives from the observation that sensitivities of J82 and SCaBER cells to BMY25282, a MMC analogue with lower quinone reduction potential, were similar. MMC dependent lipid peroxidation (an indicator of oxygen free radical formation) was higher in SCaBER cells than in J82. The activities of anti-oxsidative enzymes GSH peroxidase and catalase did not differ significantly in these cells. These results suggest that resistance of SCaBER cells to MMC may not be due to the reduced free radical formation in these cells. MMC induced DNA interstrand cross-link (ISC) formation was markedly lower in SCaBER cells than in J82. Taken together, these results suggest that SCaBER cell resistance to MMC may be due to the reduced drug activation and ISC formation in these cells.

Antibiotics, Antineoplastic↗
PubMed1995

Molecular structure alteration of IgG increased anticomplementary activity of intravenous immunoglobulin.

AIM: To study the cause of anticomplementary activities (ACA) of intravenous immunoglobulins (IVIG). METHODS: ACA were determined by two assays (limit test and 100CH50 test), distributions of IgG molecular size (polymer, dimer, monomer and fragment) by HPLC, IgG subclasses and IgA contents by radial immunodiffusion, prekallikrein activator (PKA) and kallikrein (KK) activities by chromogenic assay, potency of antibody against hepatitis B surface antigen (Anti-HBs) by enzyme-linked immunosorbent assay (ELISA). RESULTS: The two ACA assays showed good correlation. However, ACA levels were not associated with distributions of IgG molecular size, IgG subclasses and IgA contents, PKA and KK activities. After heating incubation, ACA levels increased markedly and Anti-HBs decreased notably, distributions of IgG molecular size remained relatively constant. CONCLUSION: Molecular structure alteration of IgG increased spontaneous complement activation of IVIG.

Complement Activation↗
PubMed1995

[P-NMR analysis of the hepatic cell energetic metabolism in tumor-bearing mice by moxibustion treatment].

The new technique, NMR (nuclear magnetic resonance) spectrum analysis was used in this research to measure the state of energetic metabolism of hepatic cells at the organic level. The experimental results demonstrated that moxibustion on Guanyuan (CV4) point could remarkably increase the ATP molecules in the hepatic cells, significantly raise the thermodynamic reserve and phosphate potential of the hepatic cells, so as to enhance the functional activities of liver. It is discussed here of the mechanism of anti-tumor by moxibustion treatment and of the theory of warming the kidney and enhancing the Yang to tonify to energetic Qi by moxibustion on Guanyuan point.

Animals↗
PubMed1995

Transseptal methods for percutaneous balloon valvoplasty simultaneously with radiofrequency catheter ablation.

Percutaneous balloon mitral valvoplasty (PBMV) and radiofrequency catheter ablation (RFCA) have been used in the treatment of mitral stenosis (MS) and supraventricular tachycardia. The techniques of PBMV and RFCA yield better results with the development of interventional cardiology, but there is no report about PBMV performed simultaneously with RFCA in the same patient. Seven patients with mitral stenosis and Wollf-Parkinson-White (W-P-W) Syndrome were successfully treated with PBMV and RFCA by transseptal methods. LA, LAP, mPG and mPA were decreased from 43.4 +/- 4.6mm, 21.8 +/- 6.8mmHg, 21 +/- 7.7mmHg and 45.7 +/- 16.5mmHg to 39.2 +/- 3.7mm (P < 0.05), 12.7 +/- 4.5mmHg, 12 +/- 3.7mmHg and 32.3 +/- 9mmHg (P < 0.01). MVA was increased from 0.96 +/- 0.33cm2 to 1.7 +/- 0.80cm2 (P < 0.01). delta wave disappeared in 12-lead surface EKG and SVT could not be induced in electrophysiological study after the treatment. The overall time of the procedure for this series was 93 +/- 34 minutes and fluoroscopy time was 23 +/- 7 minutes on the average. Radiofrequency energy applications were 3 +/- 2 times each procedure. PBMV and RFCA are safe and highly effective in the treatment of MS and W-P-W syndrome. The results in the present study proved the feasibility of the combined use of PBMV and RFCA. We prefer a first choice of PBMV and then RFCA in order to avoid aggravation of the hemodynamics due to mitral stenosis. The results also showed that of overall procedure and fluoroscopy only took a short time for this series. We suggest that it could be used as a routine method for the treatment of mitral stenosis complicated by W-P-W syndrome.

Adult↗
PubMed1995

Induction of osteogenesis by bovine platelet transforming growth factor-beta (TGF-beta) in adult mouse femur.

TGF-beta has been shown to be one of the most important regulators in chondrogenesis and osteogenesis. Daily subperiosteal injection of TGF-beta, which was extracted and purified from bovine platelets, into adult mouse femur resulted in proliferation and differentiation of the mesenchymal cells, chondrogenesis, and endochondral osteogenesis. After cessation of the injection, the endochondral ossification occurred widely, resulting in replacement of the cartilage with new bone. These phenomena demonstrate that exogenous TGF-beta stimulates mesenchymal proliferation and differentiation that occur in early fracture healing and suggest the possibility of clinical application of TGF-beta for fracture repair and bone transplantation.

Animals↗
PubMed1995

[Anti-hepatitis C virus screening to prevent hepatitis C virus infection in blood donors].

Before carrying out anti-hepatitis C virus (anti-HCV) screening in blood donors, 433 plasma donors and 461 whole blood donors from 4 county plasmapheresis units and 5 city blood centres in Hebei province were surveyed. Anti-HCV positive rates were 55.5% and 10.2% in the two populations respectively. The anti-HCV positive rates also differed between qualified and unqualified donors. In qualified and unqualified plasma donors, they were 46.2% and 91.6% respectively and in qualified and unqualified whole blood donors 5.8% and 42.3% respectively. One year after anti-HCV screening, 793 plasma donors and 873 whole blood donors in 3 city blood centres and 4 county hospitals were surveyed, the anti-HCV positive rates in plasma and whole blood donors were 4.0% and 0.2% respectively. Compared with those before screening, there were 91.3% and 96.6% reduction respectively. The anti-HCV positive rate in voluntary donors was 0.5%. All the 86 first time donors were negative for anti-HCV before and after screening.

Blood Donors↗
PubMed1995

[Early enteral feeding and supplement of glutamine prevent occurrence of stress ulcer following severe thermal injury].

UNLABELLED: Gastroscopic and gastric juice analysis studies were carried out on 12 patients with total body surface area over 30 percent who received early enteral feeding, supplemented with glutamine. The results indicated that early feeding was safe in major burn patients. All patients were found to have ASML on postburn days 1 to 2. Stress ulcer was not found in patients after several excision operations, and about 86 percent of ASML disappeared within about 2 weeks. CONCLUSION: early feeding and supplement of glutamine can prevent the complication of stress ulcer following severe thermal injury.

Adult↗
PubMed1995

C-JUN/AP-1 as possible mediators of tumor necrosis factor-alpha-induced apoptotic response in mouse JB6 tumor cells.

Sensitivity to cell killing by tumor necrosis factor (TNF)-alpha was seen in the JB6-derived transformed mouse RT101 cell variants previously described as resistant to 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced killing, while the TPA-sensitive variants were resistant to killing by TNF-alpha. Morphological and biochemical changes characteristic of apoptosis were found to precede TNF-alpha-induced cell death in TNF-alpha-sensitive (TNFs) but not TNF-alpha-resistant (TNFr) cells. In TNFr cells, TNF-alpha increased the cell cycle rate. The onset of cellular damage in TNFs cells, as indicated by propidium iodide uptake, was seen as early as 6 h after TNF-alpha treatment. 4,6-diamidino-2-phenylindole staining revealed chromosomal condensation approximately 4-6 h after TNF-alpha treatment. The DNA oligonucleosomal ladder of 180 bp and its multiples, a characteristic feature of apoptosis, was seen at 48 h. Little or no significant differences were found in the basal or induced levels of mRNA expression of several potential apoptosis mediator genes or apoptosis inhibitor genes. A dephosphorylated species of anti-c-Jun immunoprecipitated protein appeared in TNFs cells at 3 h posttreatment, accompanied by a parallel increase in AP-1 activity. Higher constitutive levels of the antioxidant enzymes superoxide dismutase and catalase were found in TNFr cells, but TNF-alpha did not significantly affect the activities of these enzymes or differentially induce their expression. The findings suggest that the preferential and transient increase in c-Jun dephosphorylation and AP-1 transcriptional activity may contribute to the preferential apoptotic response in TNFs cells; and that the greater constitutive oxidant defense in TNFr cells may contribute to their resistance.

Animals↗
PubMed1995

[Histochemical observation of the effect of electroacupuncture on the livers of rats with endotoxic shock].

The experimental rats were randomly divided into three groups: i.e. control group; endotoxic shock group (the model of endotoxic shock was induced by intravenous administration of E. Coli endotoxin, 16 mg/kg); and electroacupuncture (EA) group ("Renzhong" or "Zusanli" acupoint was stimulated for 15 minutes at 1 hr after injection of endotoxin). The experimental rats were decapitated at 75 minutes after injecting endotoxin. Their livers were taken out for cryostat section, and histochemical observation. The results were as follows: 1) The glycogen in the hepatic cells of endotoxic shocked rats were almost completely depleted. The activities of SDH Mg(++)-ATPase and G-6-Pase and 5'-Nase were decreased; especially the activities of 5'-Nase in the biliary canaliculi and sinusoids were apparently reduced. 2) The content of hepatic glycogen in EA group was increased, but some of them was still depleted. The activities of SDH, Mg(++)-ATPase and G-6-Pase were slightly increased as compared with that of the endotoxic shock group. The activity of 5'-Nase was obviously increased after EA. The preliminary results indicated that EA at "Renzhong" or "Zusanli" acupoint of rats with endotoxic shock might play certain role on improving the hepatic metabolism and promoting the membrane transport action.

Animals↗
PubMed1995

[Detection of K-ras oncogene activation in human lung cancer and its possible clinical application].

By using a modified polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) technique, we detected K-ras codon 12 mutation in 102 formalin-fixed, paraffin-embedded tissues from surgical samples of lung cancer patients. The X2 test was used to determine the statistical significance of difference, according to the presence or absence of mutation in codon 12 of K-ras oncogene. We found 25 cases (24%) positive for mutation of K-ras 12 codon. Mutation occurred in 6 of the 40 cases (15%) of squamous cell carcinoma, 18 of 37 adenocarcinoma cases (49%), 1 of 2 adenosquamous cases, 0 of 1 carcinoid patient, but no K-ras activation was found in small cell carcinoma (0/22) cases. Analysis of the clinical and pathological features of 37 adenocarcinoma cases showed no apparent associations between the K-ras codon 12 mutation and sex, disease stage, tumor size (T), metastatic status (M) and the degree of differentiation (all P values greater than 0.05), but the nodes (N) of K-ras-positive adenocarcinoma tended to be more than the K-ras-negative ones (P < 0.01). From 26 male cases of adenocarcinoma mutation in codon 12 of K-ras occur more frequently in adenocarcinoma from smokers than non-smokers (P < 0.05), suggesting that smoking is an important factor in the induction of the mutation. Among 37 adenocarcinoma cases, only 25 cases can be traced the recurrence rate in 1-year. The 1-year recurrence rates were 85% (11/13) in K-ras mutational patients, more than 25% (3/12) in K-ras negative ones (P < 0.01), whereas there was no relationship between recurrence and differentiation in these 25 cases. The findings suggest the K-ras gene mutation may be one of the prognostic markers for human lung adenocarcinoma.

Adenocarcinoma↗
PubMed1995

[Determination of red-cell immunology in patients with laryngeal carcinoma].

In order to study the changes of the red-cell immunology, the rosette rates of the red cell C3b receptor (RBC-C3bRR) and red cell immune complex (RBC-ICR) were measured in 30 patients with laryngeal carcinoma. The results showed that: (1) the RBC-C3bRR and RBC-ICR were lower in patients with laryngeal carcinoma than those with polypus of the cord and the normal controls (P < 0.01); (2) the RBC-C3bRR and RBC-ICR of the patients with laryngeal carcinoma did not change in about twenty days after operation (P > 0.05). The results suggest that the red-cell immunological function is lowered in the patients with laryngeal carcinoma.

Adult↗
PubMed1995

Lung cancer among workers exposed to silica dust in Chinese refractory plants.

A retrospective cohort mortality study was conducted for lung cancer among silica and clay brick workers at 11 refractory plants in China. The cohort included 6266 male workers employed before 1962 and followed between 1963 and 1985. The standardized rate ratios (SRR) were obtained by comparing the mortality rates of the silica-exposed cohort with those of a population of 11 470 male steel workers. As expected, significant excesses were observed for all deaths, all cancers, lung cancer, cardiorespiratory diseases, pulmonary heart diseases, and pulmonary tuberculosis. The lung cancer SRR was 1.49 (P < 0.01) for the total cohort. The increased lung cancer risk was attributed to the silicotics (SRR 2.10; P < 0.01) in the cohort. Higher lung cancer risk was found with increasing latency and severity of silicosis; this finding suggests that the excess was possibly related to occupational exposure to silica dust. Among the silicotics, there was a twofold excess of lung cancer risk among both the nonsmokers and the smokers.

China↗
PubMed1995

[The application of the pattern visual-evoked potential in the diagnosis and treatment of amblyopia].

PURPOSE: To research into the value of the application in the diagnosis and treatment of amblyopia, and to discuss the mechanism of amblyopia. METHODS: The subjects were divided into three groups: 108 amblyopia eyes; 180 normal eyes and 26 amblyopia eyes during the treatment with Madopar. PVEP was observed with black-white checks pattern-reversal stimulation at several spatial frequencies (30', 60', 90'). RESULTS: P1 latency of the amblyopia eyes prolongs at the high frequency (30' angle of view), in which the occurrence rate of abnormal PVEP is 68.5%. Through detecting PVEP during the treatment of amblyopia with Madopar, we found P1 latency shortened and amplitude increased (P < 0.05). CONCLUSION: It is better to use P1 latency to observe the visual function of patients with amslyopia with stimulation at 30' angle of view. PVEP is an important objective index in diagnosis and evaluating the curative effect of amblyopia.

Adolescent↗
PubMed1994

p130/pRb2 has growth suppressive properties similar to yet distinctive from those of retinoblastoma family members pRb and p107.

The retinoblastoma tumor suppressor gene product, as well as its related protein p107, has been shown clearly to exert its growth suppressive effects in a cell cycle dependent manner. In this study we demonstrate that the introduction of our recently cloned Rb family member p130/pRb2 causes growth arrest in three tumor cell lines. In addition, in the nasopharyngeal carcinoma derived cell line HONE-1, we identified a low level of expression of p130/pRb2, possibly due to gene rearrangement, and a drastic reduction in proliferation upon introduction of a constitutive active p130/pRb2 complementary DNA clone. Furthermore, we were able to dissect distinct properties of the Rb family by demonstrating that p130/pRb2 inhibits proliferation of the glioblastoma cell line T98G, which is resistant to the growth suppressive effects of both pRb and p107. Our studies demonstrate that the Rb family proteins identified to date may complement each other but they are not fully functionally redundant.

Cell Division↗
PubMed1994

Purity control of different bee venom melittin preparations by capillary zone electrophoresis.

A rapid capillary zone electrophoresis method was developed for the determination of melittin during its purification from bee venom by column chromatography. Low-pH buffer was selected to decrease the adsorption of the analytes on capillary wall. The average relative standard deviations of the migration time of melittin and of the peak area were 1.2 and 2.3%, respectively.

Bee Venoms↗