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Biomedical subjects

S Wu

Publications and source records attributed to S Wu.

At least 325 records · Page 18Linked to original sources
PubMed1997

Transient lumanopia: the invisibility of flicker in early dark adaptation.

Flicker thresholds for brief white (5-arcmin, 16-18-Hz) foveal flicker bursts can rise for at least 1 s after a steady white adapting field is extinguished. We call this anomalous loss of sensitivity in early dark adaptation lumanopia by analogy with dyschromatopsia, a similar anomaly of the hue pathways. Lumanopia is greatest at 400 Td. Flicker thresholds for 10-12 Hz flicker bursts do not show lumanopia. The temporal-frequency dependence of lumanopia is specific to early dark adaptation, as flicker thresholds vary little from 10 to 18 Hz after steady light or dark adaptation. Lumanopia has implications for models of retinal gain controls.

Dark Adaptation↗
PubMed1997

[Effects of EDRF on the vasoconstrictor action of phenylephrine in rat aorta].

The influence of endothelium-derived relaxing factor (EDRF) on the vasoconstrictor effect of phenylephrine on rings of rat aorta was studied in this paper. Rings of rat aorta, with or without endothelium, were suspended in organ chambers for the measurement of contractive force and contractive speed. All experiments were performed in the presence of indomethacin (10 mumol/L) to prevent the production of vasoactive prostanoids. When the preparations with intact endothelium were treated with methylene blue (10 mumol/L), an inhibitor of the target enzyme of EDRF, or NG-nitro-L-arginine (30 mumol/L), an inhibitor of EDRF formation, dose-contractive force curves of phenylephrine shifted to left: the EC30 value decreased 5-fold and the maximal response ratios were 1.6 +/- 0.4 and 1.6 +/- 0.5 (n = 8) respectively. These results were similar to those observed after mechanical removal of the endothelium: a 3-fold decrease in the EC30 value and the maximal response ratio was 1.0 +/- 0.2 (n = 8), The latter results may be related to a little EDRF produced by vascular smooth muscle. Our results suggest that the vasoconstrictive effect induced by phenylephrine may also be regulated by EDRF production from vascular endothelium and smooth muscle.

Animals↗
PubMed1997

[A study on the effects of three kinds of treatment in chronic hepatitis B].

To study the effects of three kinds of treatment: Zhuling polysaccharides combined with hepatitis B vaccine (group I), LAK cells, induced by interleukin-2 (IL-2) in vitro, transfusion therapy, (group II), bacille Calmette-Guerin (BCG) combined with persatin (group III) in chronic hepatitis B and the mechanism of their effects, we observed 286 patients with chronic hepatitis B, diagnosed according to the criteria made by The 6th National Meeting for Viral Hepatitis and Substantiated by the results of liver biopsy. The patients were divided into 3 treatment groups randomly, with interferon 3 MIU, thrice a week and 10% glucose 500 ml (i.v.) dripping everyday as two different control groups. The ALT recovery rates in group I, II, III were 64%, 35% and 57%, respectively. At the end of the treatment, the HBeAg and HBV DNA clearence rates in group I, II, III were 43% and 44%, 34% and 30%, 57% and 61%, respectively. After one year of follow up, the HBeAg and HBV DNA clearence rates in group I, II, III were 59%, 58%, 61% and 55%, 70%, 60%, respectively. The effects of these kinds of treatment were similar to these of interferon. We also injected Zhuling polysaccharides combined with hepatitis B vaccine, Zhuling polysaccharides alone and normal saline as control to DHBV vertical transmission duck. It was shown that serum DHBV DNA was cleared and the results were also proved by liver histologic change in the two treatment groups. According to these data, it is suggested that the three kinds of treatment for hepatitis B could restore the ALT level, suppress the replication of HBV and improve the liver histologic change. Their effects were similar to those of interferon.

Adult↗
PubMed1997

[The role and mechanism of fatty acids in gallstones].

18 Chinese cases and 37 Japanese cases of gallstones were analyzed according to the procedure of extracting fatty acids in the gallstone. High perforamance liquid chromatography (HPLC), showed that the contents of total fatty acid and free fatty acid in pigment stones were obviously higher than those in black stone or cholesterol stone. The ratio free saturated to total saturated fatty acid is the highest in intrahepatic pigment stone and less in extrahepatic pigment stone, which significantly differs from the latter two kinds of stones. This may indicate that phospholipid in the bile catablizes into free fatty acids involved in the formation of stone under the action of phospholipase in the course of pigment stone formation. The action of phosphoipase A1 is more important than phospholipase A2.

Bile Ducts, Intrahepatic↗
PubMed1997

[Nuclear matrix protein pattern in human hepatocellular carcinoma].

OBJECTIVE: To compare nuclear matrix proteins of normal liver with those of hepatocellular carcinoma (HCC) to see whether there are HCC-specific proteins. METHODS: Using high resolution two-dimensional polyacrylamide gel electrophoresis, the nuclear matrix proteins of 3 normal livers and 8 HCC were compared. RESULTS: There was a high degree of similarity between nuclear proteins of normal liver and those of HCC. Four HCC-specific nuclear matrix proteins were identified. Among them, one protein(Mr: 62,000; pI: 5.3) appeared in all tumor samples. The other three proteins appeared in most of the 8 HCC cases. These proteins were not detected in 3 normal livers. CONCLUSION: There are HCC-specific nuclear matrix proteins which may be related to the etiology and pathogenesis of HCC.

Antigens, Nuclear↗
PubMed1997

[Multivariate prognostic analysis of carcinoma of the gastric cardia and comparative study of different resections].

OBJECTIVE: To evaluate the clinical characteristics and prognostic factors for long-term survival of patients with cancer of gastric cardia. METHODS: Logistic regression, log-rank test were used to analyze survival and evaluate the results of different resection procedures. RESULTS: Of the 263 patients, the male to female ratio was 8.4:1, the average age of female patients was younger than that of male patients. Sex, depth of invasion and lymph node involvement were prognostic factors of long-term survival. The extent of gastric resection and lymph node dissection, and pre-operative chemotherapy did not significantly affect survival. Higher frequency of postoperative complications was observed in patients received extended dissections, but did not affect survival. However, for patients in stage III N0-1, extended dissection resulted in longer survival than those received routine radical resection. CONCLUSION: Cancer of the gastric cardia has its own clinical characteristics. The surgical procedures should be adjusted according to the prognostic factors. For relatively early cases, extended dissection is recommanded.

Adenocarcinoma↗
PubMed1997

[An experimental study on the effects of lingzhi spore on the immune function and 60Co radioresistance in mice].

Lingzhi spore (2 g.kg-1.d-1, 10 times) was orally administered to mice, and studies were carried out on the carbon clearance, delayed-type skin hypersensitivity (DTH), antibody hemagglutinin value and spleen weight. The results showed that Lingzhi spore could increase the immune function, inhibit the reduction of white blood cells and raise the survival rate of mice after they were radiated by 870 rad 60Co.

Animals↗
PubMed1997

[Cloning and expression in Escherichia coli of an alkaline and thermostable exolipase from Pseudomonas pseudoalcaligenes].

A gene coding for an alkaline and thermostable exolipase of Pseudomonas pseudoalcaligenes was cloned into Escherichia coli LE392 by inserting Sau3 AI-generated DNA fragments into the BamHI site of pIJ285. Four colonies with esterase and lipase activities on the tributyrin agar plate were isolated by screening the constructed pseudomonas pseudoalcaligenes genomic library. Only one out of the four positive colonies showed lipase activity on the agar plate contatining olive oil and Rhodamine-B. Subclones of the 45 kb insert carrying lipase gene was obtained in E. coli HB101 using pUC118 as a vector, two of which (HB101 (pHZ1402) and HB101 (pHZ1403)), retained lipase activity, but the level seems to be different. They carried 3.0 kb and 2.9 kb inserts with a 2 kb overlapping sequence. The lipase activity of HB101 (pHZ1403) is about 4 times higher than that of HB101 (pHZ1402), as 5 times as that of original strain P. pseudoalcaligenes.

English Abstract↗
PubMed1997

[The regulation effects of Angelica sinensis on the erythrocytic immune function and IL-2 in mice].

The effects of Angelica sinensis solube extract on erythrocytic C3b receptor rosette rate and immune complex rosette rate and activities of interleukine-2 (IL-2) in mice are observed in this article. Angelica sinensis can significantly enhances erythrocytic C3b recepor rosette rate and IL-2 activities. The regulating actions of Angelica sinensis on erythrocytic C3b recepor rosette rate and IL-2 activities may be the direct effects.

Adjuvants, Immunologic↗
PubMed1997

[Quantitative study of calcitonin gene methylation in myelodysplastic syndromes].

OBJECTIVE: To investigate the role of calcitonin gene hypermethylation in the transformation from myelodysplastic syndromes (MDS) to acute myeloid leukemias (AML). METHODS: The methylation rate of calcitonin gene (CTMR) in the genomic DNA extracted from bone marrow cell of 27 MDS patients and 6 AML patients with antecedent MDS were studied by PCR amplification of Hpa I digested DNA, with external reference of undigested and Msp I digested DNA and internal reference of 112bp fragment containing N-ras-61. Intensity of silver-stained PCR products was measured by densitometer and analysed using the computer program. RESULTS: The CTMR was significantly higher in MDS (33.65% +/- 23.37%) than in control group (P<0.001), in 9 RAEB(T) (58.35% +/- 17.44%) than in the control and RA groups. Five RA patients who have survived three to ten years without leukemia, have a normal CTMR. Seven of 8 RAEB(T) patients who had a high CTMR of more than 30% evolved into AML in two months. CONCLUSION: CTMR might be a useful marker for predicting the evolution of MDS into AML.

Adolescent↗
PubMed1997

Analysis of clonality of lymphocytic leukemia and lymphoma by T-cell receptor gene rearrangement.

OBJECTIVE: To analyse the relationship between the number of T-cell receptor (TCR) gamma gene rearrangement and clonality of malignant cells in lymphocytic leukemia and lymphoma. METHODS: The TCR gamma gene characteristics of 73 cases of lymphocytic leukemia and lymphoma and other diseases that had presented 1 or 2 prominent bands of amplified TCR gamma VI subgroups-J1/2 gene rearrangement (GR) were detected by polymerase chain reaction-restriction enzymes (PCR-RE), heteroduplex formation (HDF), DNA sequencing and single-strand conformational polymorphism (SSCP). RESULTS: Thirty-four percent patients had 2 of TCR gamma GR (biallelic rearrangement); twenty-six percent had 1 of TCR gamma GR; fifty-four percent of acute lymphocytic leukemia's and nineteen percent of non-Hodgkin's lymphomas (NHL) had 2 of TCR gamma GR. HDF could rapidly confirm more than 1 of alleles while more alleles were difficult to be recognized by restriction analysis. Sense and antisense strands of heteroduplex were composed of 2 of TCR gamma GR respectively. By combining HDF method, oligoclonalities in three patients (2 acute lympholytic leukemia and 1 myelodysplastil syndrome and clone evolution in one NHL were found. CONCLUSIONS: The fact that many patients had 2 of TCR GR means that complications of two neoplastic clones can be affirmed only if more than 2 of TCR GR are found. HDF can be used to detect the clonality, oligoclonality and polyclonality of lymphoid cells in lymphocytic leukemia and lymphoma by analysis of the difference of gene segments. HDF is a reliable method for the clone evolution research of lymphoid malignancies in progression.

Base Sequence↗
PubMed1997

Mitochondrial tRNA(Leu(UUR)) gene mutation diabetes mellitus in Chinese.

OBJECTIVE: To ascertain the prevalence and clinical features of mitochondrial tRNALeu(UUR) gene nucleotide (nt) 3243 A-->G mutation diabetes mellitus in Chinese and to establish the approaches for genetic diagnosis of this subtype of diabetes during routine daily clinical practice. METHODS: Mitochondrial nt 3243 A-->G mutation was screened among 207 unrelated non-insulin-dependent diabetes mellitus (NIDDM) patients by using polymerase chain reaction (PCR)/Apa I restriction endonuclease digestion. Samples with positive result were confirmed by DNA sequence analysis. Genetic and clinical analysis were carried out in family members of the proband with positive genetic diagnosis. RESULTS: Positive results were found in two subjects during screening of unrelated NIDDM patients, which account for 2.4%-11.1% of NIDDM subjects with uncommon clinical features (with early age-of-onset, with low body-mass-index and on insulin therapy) or with positive family history of diabetes consistent with or unable to exclude from maternal inheritance. Genetic diagnosis was positive in 10 out of 25 family members in the pedigrees of these two probands. CONCLUSIONS: Mitochondrial tRNALeu(UUR) gene nt 3242 A-->G mutation should be considered in diabetic patients with the above-mentioned clinical features. The genetic diagnosis in daily clinical practice can be performed with allele specific priming amplification, or PCR/Hae III or Apa I digestion which are technically simple to perform and diagnostically easy to define.

Adolescent↗
PubMed1997

[Effect of pretreatment counseling on discontinuation rates in women given depo-medroxyprogesterone acetate for contraception].

OBJECTIVE: To investigate the effect of pre-treatment counseling on discontinuation rates of 150 mg depo-medroxyprogesterone acetate (DMPA), given for contraception. METHODS: A total of 421 women participated, 204 receiving intensive structured pre-treatment and on going counseling on the hormonal effects and probable side effects of DMPA and 217 receiving only routine counseling. All participants were followed up at every 3 months for 1 year. The primary endpoint was termination rate, secondary endpoints were frequency of medical events and reasons for termination. RESULTS: The most common reasons for terminating DMPA were menstrual changes. Although women in the intensive structured counseling group reported more menstrual irregularity (39.7%) than did women in the routine counseling group (26.3%), study termination rates were significantly lower in the intensively structured counseling group than in the routine counseling group. At one year, the total cumulative termination rates were 11.3% (23/204) and 42.4% (92/217), respectively (P < 0.0001). No pregnancy and serious medical events were reported. CONCLUSION: Pre-treatment counseling on expected side effects increases the acceptability of DMPA.

Adolescent↗
PubMed1997

[Relationship between angiotensin 1 converting enzyme gene polymorphism and diabetic nephropathy].

OBJECTIVE: To clarify if ACE gene I/D polymorphism attributes to the development of non-insulin dependent diabetes mellitus (NIDDM) and renal complication. METHODS: A fragment of 287 bp Alu sequence in inron 16 of ACE gene was used as I/D polymorphic marker. After PCR amplification of DNA fragment, 12% non-denatured polyacrylamide gel electrophoresis was undertaken to analyze the PCR products. RESULTS: Allele D was the prominent one (frequency 0.75) in the subgroup of DN which was complicated in the earliest stage of NIDDM without HTN, CHD and diabetic retinopathy. However, the frequency of allele D was low (0.39) in the subgroup of NIDDM without DN, HTN, CHD and diabetic retinopathy, in which the duration of each subject was over 5 years. It was significant to compare these two mentioned subgroups (P < 0.02, continuity-adjusted X2test, P < 0.05). The distribution of genotype in the whole NIDDM group without HTN and CHD (69 cases) was very similar to the normal control (110 subjects) (I 0.60 to 0.59, D 0.40 to 0.41). CONCLUSION: The I/D polymorphism of ACE gene may be the factor of genetic predisposition of early-onset diabetic nephropathy in Chinese NIDDM.

Adult↗
PubMed1997

Analysis of tumor specific immunoglobulin gene rearrangement in peripheral blood B-cells of multiple myeloma patients by a PCR-SSCP method.

OBJECTIVE: To analyze the clonal relationship between lymphocytes in peripheral blood (PB) and myeloma cell in bone marrow (BM) for proving the existence of circulating tumor cells in multiple myeloma (MM) patients. METHODS: Eighteen patients with MM who have no cytomorphologic plasma cells and CyIg+ cells in PB demonstrated by anti-kappa and anti delta MoAbs using ABC method were involved in the present study, including 3 cases in phases I-II and 15 cases in phase III. The complementary determining region 3 (CDR3) of immunoglobulin heavy chain (IgH) gene was amplified by polymerase chain reaction (PCR). We further analysed the single strand conformation of the PCR products by single strand conformation polymorphism (SSCP) analysis to detect the mononuclear cells in PB and BM of the patients simultaneously. RESULTS: The same PCR products of IgH-CDR3 gene with BM samples were found in PB of 11 MM patients. The same PCR products and single strand conformation in both PB and BM were found in 9 cases. CONCLUSIONS: This study has proved the presence of identical clonal malignant cells in PB and BM of MM patients. B cells are involved in the pathogenesis of MM.

Adult↗
PubMed1997

[Changes of inflammatory mediator in aucte necrotizing pancreatitis and effect of somatostatin analogne stilamin in rats].

OBJECTIVES: To investigate the changes of inflammatory mediator in ANP and to explore the effectiveness of stilamin treatment on ANP. METHODS: SD rats were divided into experimental groups (ANP = 12, ANP + NS = 10, ANP + Stilamin = 12) and control group (NC = 10). Rat ANP models were made by retrograde injection of 3.5% sodium taurocholate 2.5 ml/kg into the pancreatic duct, and treated by intravenous injection of stilamin 84 micrograms.kg-1.d-1 or same amount of normal saline respectively. Serum IL-1 beta, IL-6, IL-12, TNF-alpha, PLA2, amylase and endotoxin were examined. Finally, the morphology and pathology of the pancreas, liver, lung, heart and kidney, as well as the electronmicroscopical investigation of liver and lung cells were observed. RESULTS: The mean IL-1 beta, IL-6, IL-12, TNF-alpha, in the ANP and ANP + NS group were higher than those in the ANP + stilamin group and Control group (P < 0.01). The endotoxin, amlyase, PLA2 level in the ANP + stilamin group was lower than those in the ANP and ANP + NS groups (P < 0.001). ANP significantly increased white blood cell chemotax and infiltration, as well as hemorrhagic focus in liver, kidney and lung, but the pathological examinations of the liver, pancreas, lung and kidney demonstrated much less destruction in the stilamin group. CONCLUSIONS: Inflammatory cytokins play an essential role to induce pathophysiological process of ANP, and its related MODS may be effectively prevented and treated by stilamin.

Animals↗