Biomedical subjects

Li Su

Publications and source records attributed to Li Su.

65 records · Page 4Linked to original sources

PubMed2003

[Study on diagnostic criterion of pregnancy induced hypertension].

OBJECTIVE: To study the rationality of the current diagnostic criterion of pregnancy induced hypertension (PIH) in mainland China. METHODS: To analytically review the 916 cases of PIH in our hospital, reclassify them using both the current domestic diagnostic criteria and the William Obstetrics' criteria, then compare and analyze perinatal and maternal outcomes from the two standards. RESULTS: (1) Maternal outcomes: comparison result of the occurrences among three groups of premature birth, postpartum haemorrhage and placental abruption according to domestic classification had significant difference (P < 0.05). And it's the same result according to foreign classification (P < 0.05). But the occurrences within three groups of premature birth, postpartum haemorrhage and placental abruption between domestic and foreign classifications showed no significant difference (P > 0.05). (2) Perinatal outcomes: Comparison results of the occurrences among three groups of fetal growth restriction, asphyxia neonatorum and perinatal fetal and neonatal death incidence according to domestic classification had significant difference (P < 0.05). And it's the same result according to foreign classification (P < 0.05). But the occurrences within three groups of fetal growth restriction, asphyxia neonatorum and perinatal fetal death and neonatal incidence showed no significant difference (P > 0.05). (3) The constituent ratio of mild, moderate, severe PIH according to domestic classifications was 46.6%, 18.4%, 34.9% respectively. The constituent ratio of gestationgal hypertision, mild preeclampsia and severe preeclampsia according to foreign classifications was 47.6%, 14.3%, 38.1%. There were significant differences between domestic and foreign constituent ratio (P < 0.05). If you compare the results from these two diagnostic classifications, with mild PIH, the accordant rate was 85.0%; with severe PIH, the rate was 93.8%; but it's only 40.2% with moderate PIH. CONCLUSIONS: The diagnostic criteria for PIH being used in our mainland China is rational, but in the current stage, due to the lack of objective index for early diagnosis and overall assessment of patient's condition, it's also limited. More objective index should be adopted to improve the diagnostic standard for PIH.

Female↗

PubMed2003

[The expression of fusion protein GST-GP302 in E.coli and its preparation of rabbit anti-serum].

AIM: To express fusion protein of GST and vWf binding domain(GP302) of platelet GPIbalpha in E.coli and its preparation of rabbit anti-serum. METHODS: GP302 gene was inserted into pGEX-4T-1. The recombinant vector was identificated by restriction endonuclease digestion analysis. Fusion protein GST-GP302 was expressed in E.coli via IPTG induction. The rabbit antibody against GST-GP302 was prepared by using renatured GST-GP302 as immuneogen and the specificity of polyclonal antibody was identified by Western blot. RESULTS: The restriction endonuclease digestion analysis of recombinant plasmid demonstrated that the GP302 gene had been exactly inserted into pGEX-4T-1. SDS-PAGE analysis showed that the ralative molecular mass(M(r)) of the fusion protein was about 59 000. ELISA analysis proved that the titer of rabbit serum against GST-GP302 was 10(-5). The polyclonal antibody specifically bound to purified platelet GPIbalpha. CONCLUSION: The preparation of polyclonal antibody against GP302 peptide provides an usefal reagent for the detection of platelet GPIbalpha.

Animals↗

PubMed2002

Combinations of the variant genotypes of GSTP1, GSTM1, and p53 are associated with an increased lung cancer risk.

GSTP1 and GSTM1 are genes involved in Phase II metabolism, whereas p53 is a tumor suppressor gene. Individually, functional polymorphisms of these genes have been studied as risk factors for lung cancer. Small sample sizes have hindered the detection of possible increases in risk associated with having two or more "at risk" polymorphisms of these three genes. In a large Caucasian population, we examined the association of combined variant genotypes [or double-variants (DVs)] of these three genes and lung cancer risk, compared with their corresponding "double-wild-type" genotypes. Because these DVs may promote lung carcinogenesis at an earlier age, a subgroup of individuals aged 55 years or younger was examined separately. Using a case-control design, individuals were genotyped for GSTM1, GSTP1, and p53 codon 72 using PCR-RFLP techniques. All of the analyses used multiple logistic regression. Indicator variables were created to evaluate the risk for individuals with the following DVs: GSTP1 GG + GSTM1-null and GSTP1 GG + p53 Arg/Pro or Pro/Pro. A total of 1694 cases and controls were evaluated. In the whole population, those with the double variants have a higher risk of lung cancer when compared with those with the double-wild-type genotypes, supporting our original hypothesis. Individuals with the GSTP1 and GSTM1, DV (P1-M1 DV) had a marginally significant higher risk of lung cancer compared with their double-wild-type counterparts [adjusted odds ratio (AOR), 1.60; 95% confidence interval (CI), 0.95-2.70]. A significantly higher risk was found for the GSTP1, p53 DV (P1-p53 DV; AOR, 1.99; 95% CI, 1.12-3.53). Among individuals aged 55 or younger, these risks were even higher: for the P1-M1 DV the AOR was 4.03 (95% CI, 1.47-11.1); for the P1-p53 DV the AOR was 5.10 (95% CI, 1.42-18.30). Specific DVs of GSTM1, GSTP1, and p53 codon 72 are associated with a higher lung cancer risk. This susceptibility is highest among younger individuals.

Adult↗

PubMed2002

[Influencing factors of local immunocyte infiltration in hepatocellular carcinoma tissues pre- and post-percutaneous microwave coagulation therapy].

OBJECTIVE: To investigate the influencing factors of the local immunity in tissues of hepatocellular carcinoma (HCC) before and after percutaneous microwave coagulation therapy (PMCT). METHODS: Seventy-eight patients with HCC diagnosed by needle biopsy of liver underwent PMCT. Before the treatment and three and 17 days after the treatment specimens of carcinoma tissues were obtained by ultrasound-guided liver biopsy. The extents of infiltration of CD3(+) cell, natural killer cells (CD56(+)), and macrophages (CD68(+)), and the expression rate of proliferating cell nuclear antigen (PCNA) were evaluated by immunohistochemistry. The relation between the extents of immunocyte infiltration and the clinical parameters was analyzed with multiple regression. RESULTS: Before PMCT infiltration of the three kinds of immunocytes was found in the carcinoma tissues to different degrees with a great variation among individuals. A remarkable increase in the extent of infiltration of the three kinds of immunocytes was found three days after the treatment and continued or remained till the 17th post-PMCT day (P < 0.01). The post-PMCT extent of immunocyte infiltration was positively correlated with the pre-PMCT extent (CD3(+): r = 0.256, P = 0.005; CD56(+): r = 0.257, P = 0.002; CD68(+): r = 0.275, P = 0.001). A negative correlation was found between the extent of immunocyte infiltration and serum alpha-fetal protein (AFP) and between the extent of immunocyte infiltration and tumor size (for serum AFP, CD3(+): r = -0.075, P = 0.049; CD56(+): r = -0.062, P = 0.041; CD68(+): r = -0.007, P = 0.035; for tumor size, CD3(+): r = -0.074, P = 0.051; CD56(+): r = -0.100, P = 0.012; CD68(+): r = -0.109, P = 0.038). No correlation was found between the extent of immunocyte infiltration and age of patient, Child-Pugh class of tumor, grade of tumor differentiation, and number of tumor. The extent of immunocyte infiltration was lesser in the carcinoma tissues with higher expression rate of PCNA. The extent of immunocyte infiltration was greater in the carcinoma tissues where PCNA expression was negative and carcinoma cells had necrotized but with their structure recognizable. No immunocyte infiltration was found in the necrotic and structureless tumor tissues. CONCLUSION: The local immunocyte infiltration in patients with HCC was influenced by serum AFP and the grade of tumor cell necrosis pre- and post-PMCT. Destruction of tumor tissue in situs by PMCT is the premise of increase of immunocyte infiltration. Before PMCT improving the immune status of the patients helps enhance the local immune response.

Adult↗

PubMed2002

Metal ions and flexibility in a viral RNA pseudoknot at atomic resolution.

Many pathogenic viruses use programmed -1 ribosomal frameshifting to regulate translation of their structural and enzymatic proteins from polycistronic mRNAs. Frameshifting is commonly stimulated by a pseudoknot located downstream from a slippery sequence, the latter positioned at the ribosomal A and P sites. We report here the structures of two crystal forms of the frameshifting RNA pseudoknot from beet western yellow virus at resolutions of 1.25 and 2.85 A. Because of the very high resolution of 1.25 A, ten mono- and divalent metal ions per asymmetric unit could be identified, giving insight into potential roles of metal ions in stabilizing the pseudoknot. A magnesium ion located at the junction of the two pseudoknot stems appears to play a crucial role in stabilizing the structure. Because the two crystal forms exhibit mostly unrelated packing interactions and local crystallographic disorder in the high-resolution form was resolvable, the two structures offer the most detailed view yet of the conformational preference and flexibility of an RNA pseudoknot.

Crystallization↗

PubMed2002

Gene-environment interaction for the ERCC2 polymorphisms and cumulative cigarette smoking exposure in lung cancer.

Excision repair cross-complementing group 2 (ERCC2), a major DNA repair protein, is involved in nucleotide excision repair and basal transcription. The ERCC2 polymorphisms have been associated with altered DNA repair capacity. We investigated two ERCC2 polymorphisms, Asp312Asn and Lys751Gln, in 1092 Caucasian lung cancer patients and 1240 spouse and friend controls. The results were analyzed using generalized additive models and logistic regression, adjusting for relevant covariates. The overall adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were 1.47 (95% CI, 1.1-2.0) for the Asp312Asn polymorphism (Asn/Asn versus Asp/Asp) and 1.06 (95% CI, 0.8-1.4) for the Lys751Gln polymorphism (Gln/Gln versus Lys/Lys). Gene-smoking interaction analyses revealed that the adjusted ORs for each of the two polymorphisms decreased significantly as pack-years increased. When comparing individuals with Asn/Asn + Gln/Gln versus individuals with Asp/Asp + Lys/Lys, the fitted ORs (95% CIs) were 2.56 (95% CI, 1.3-5.0) in nonsmokers and 0.69 (95% CI, 0.4-1.2) in heavy smokers (80 pack-years; P < 0.01 for the interaction term). Consistent and robust results were found when models incorporated different definitions of cumulative cigarette smoking. A stronger gene-smoking interaction was observed for the Asp312Asn polymorphism than for the Lys751Gln polymorphism. In conclusion, cumulative cigarette smoking modifies the associations between ERCC2 polymorphisms and lung cancer risk.

Adult↗

PubMed2002

Genetic polymorphisms in N-acetyltransferase-2 and microsomal epoxide hydrolase, cumulative cigarette smoking, and lung cancer.

N-acetyltrasferase-2 (NAT2) and microsomal epoxide hydrolase (mEH) are polymorphic genes that metabolize different tobacco carcinogens. Smaller studies found inconsistent relationships between NAT2 or mEH polymorphisms and lung cancer risk. To determine whether there is gene-environment interaction between NAT2 polymorphisms, alone or in combination with mEH polymorphisms, and cumulative smoking exposure in the development of lung cancer, we conducted a case control study of 1115 Caucasian lung cancer patients and 1250 spouse and friend controls. The results were analyzed using generalized additive models and logistic regression, adjusting for relevant covariates. There was no overall relationship between NAT2 genotype and lung cancer risk; the adjusted odds ratio (OR) of the rapid versus slow acetylator genotypes was 0.96 [95% confidence interval (CI), 0.79-1.16]. However, gene-environment interaction analyses revealed that the adjusted ORs increased significantly as pack-years increased. For nonsmokers, the fitted OR was 0.66 (95% CI, 0.44-0.99), whereas for heavy smokers (80 pack-years), the OR increased to 1.22 (95% CI, 0.89-1.67). When comparing the extreme genotype combinations of the NAT2 rapid acetylator, higher mEH activity genotype to the NAT2 slow acetylator, and very low mEH activity genotype, the corresponding ORs at 0 and 80 pack-years were 0.30 (95% CI, 0.14-0.62) and 2.19 (95% CI, 1.26-3.81), respectively. Results were similar with ORs derived from stratified models. In conclusion, NAT2 rapid acetylator genotypes are protective against lung cancer in nonsmokers but are risk factors in heavy smokers. The joint effects of NAT2 and mEH polymorphisms are consistent with an independent, additive effect of these two genes, modified by smoking history.

Adult↗

PubMed2002

[Ultrasonography in the diagnosis of hepatic malignant cystic tumors].

OBJECTIVE: To evaluate the clinical application of gray scale and color Doppler sonography in the diagnosis of hepatic malignant cystic tumors. METHODS: Characteristics of gray scale and color Doppler sonography were studied in 16 cases of malignant hepatic tumors confirmed by pathology. Tumor size, shape, number of lesion, thickness of cystic wall and echogenecity of the lesion were observed with gray scale sonography. Blood supply of the tumor and its velocity were observed with Color Doppler sonography. RESULTS: One single lesion was common in primary malignancy while multiple lesions signified metastasis. Sonographic findings revealed that the shape of the tumor was spheroid in 8 cases, irregular in 5 and leaf-shaped in 3, with the diameter varying from 1.9 cm to 13.6 cm. Sonography showed malignant cystic tumor with irregular thick wall in 15 cases, multiple septa in 7 cases and papillary projections in 6 on gray scale. Color Doppler flow signal was detected in the irregular thick wall, multiple septa or papillary projections in 14 cases, of which the arterial blood flow signals were demonstrated in 13. CONCLUSION: Color Doppler is able to clearly detect the blood flow signals in the irregular thick wall, multiple septa or papillary projections, providing an important sign for the diagnosis of hepatic malignant cystic tumors.

Adult↗

PubMed2002

Significance of changes in local immunity in patients with hepatocellular carcinoma after percutaneous microwave coagulation therapy.

OBJECTIVE: To assess the local immune response in patients with hepatocellular carcinoma after percutaneous microwave coagulation therapy (PMCT). METHODS: Seventy-eight patients with hepatocellular carcinoma underwent PMCT. Both cancerous and adjacent liver tissue were taken before, and 3, 17 and 30 days after PMCT using ultrasound-guided liver biopsy. Specimens were stained by immunohistochemical techniques for detecting CD3, CD45RO, CD56, CD68, and CD20 positive cells. RESULTS: A few CD3, CD45RO, CD56, CD68 and CD20 positive cells were observed in the cancer stroma and surrounding sinusoids in liver tissue pre-PMCT. The number of immunocytes, except for CD20 positive cells, was significantly increased both within the cancer and the adjacent liver tissue, with a larger increase in tumor tissue at day 3 post-PMCT compared with pre-PMCT. These immunocytes were enlarged in size. The number of CD3, CD45RO and CD56 positive cells peaked at day 17 and CD68 positive cells peaked at days 3 post-PMCT. At day 30 post-PMCT, this increase still existed. These infiltrating immunocytes distributed in the parenchyma of the tumor, and within the lumen of small blood vessels after PMCT. In addition, more infiltrated immune cells were seen in cancer cell spaces. CONCLUSIONS: A change in immunocyte infiltration takes place in number, configuration and location after patients with HCC are treated with percutaneous microwave coagulation, suggesting that local immune function is enhanced post-PMCT.

Adult↗

PubMed2002

Counterpoint: the myeloperoxidase -463G-->a polymorphism does not decrease lung cancer susceptibility in Caucasians.

The myeloperoxidase (MPO) G-to-A substitution polymorphism in the promoter region of the MPO gene has been associated with a 40-70% reduction in lung cancer risk in several studies, although a recent nested case-control study disputes these findings. MPO is involved in the activation of a number of procarcinogens, including benzo(a)pyrene. The variant A allele has been shown to reduce MPO mRNA expression, thus potentially decreasing carcinogen activation. To confirm results from smaller studies, we evaluated this MPO polymorphism in 988 incident Caucasian lung cancer cases and 1128 controls. Logistic regression evaluated the association between MPO genotype and lung cancer risk, adjusting for age, gender, smoking status, time since quitting smoking, and pack-years of smoking. In the controls, the A allele frequency was 21%, and genotype distribution was in the Hardy-Weinberg equilibrium. Compared with the wild-type G/G genotype, the adjusted odds ratios for the A/A and A/G genotypes were 1.15 (95% confidence interval 0.7-1.9, P > 0.2) and 1.03 (95% confidence interval 0.8-1.3, P > 0.20), respectively. A similar lack of association was seen in analyses stratified by smoking status, median age, a number of smoking variables, disease stage, tumor grade, and histological subtype. These findings are in contrast with earlier studies suggesting a protective effect of carrying the variant A allele.

Adult↗

PubMed2002

[Ultrasound-guided percutaneous microwave coagulation therapy for primary hepatocellular carcinoma].

OBJECTIVE: To evaluate the long-term results of percutaneous microwave coagulation therapy (PMCT) for primary hepatocellular carcinoma. METHODS: From May 1994 to May 2000, 177 hepatocellular carcinoma patients with 265 nodules underwent PMCT with ultrasound (US) guidance. The tumor size varied from 1.5 to 8.7 cm (median 4.12 + 1.9 cm). Follow-up examination was carried out with colour US, CT, MRI and AFP. 184 nodules were re-biopsied during the follow up of 5 - 74 months (median 29 months). RESULTS: After PMCT, colour Doppler flow signals disappeared in 92.0% (207/225) of patients. No enhancement was observed in 88.5% (138/156) by CT and 88.9% (32/36) by MRI. Re-biopsy of 184 nodules showed complete necrosis in 92.4% (170/184). Six resected lesions showed complete tumor necrosis in 5 and subtotal necrosis in 1. The 1- to 5-year survival rates were 90.1%, 76.9%, 68.3%, 64.2% and 57.8%, respectively. The survival rates of the well differentiated lesions were better than those of the poorly ones (P < 0.05). But there was not statistical significance between the moderately and the well differentiated ones. The new lesions development rates in 1 to 5 years were 26.1%, 37.8%, 43.5%, 48.6% and 58.9%, respectively. However, there was no severe complication. CONCLUSION: Ultrasound-guided microwave coagulation is safe and effective for primary hepatocellular carcinoma. It can eliminate tumors less than 5 cm in diameter.

Adult↗