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Biomedical subjects

S Ye

Publications and source records attributed to S Ye.

At least 127 records · Page 7Linked to original sources
PubMed1997

[Estrogen receptor expression and its relationship with biologic feature in hepatocellular carcinoma].

OBJECTIVE: For understanding the clinicopathologic significance of estrogen receptor (ER) in hepatocellular carcinoma (HCC) ER of the surgical resected species was detected and its relation to biologic feature was analysis. METHODS: ER was detected in 62 HCC species with Dextran coated charcoal method. Some pathologic characteristics were studied with gross and microscopic examination and proliferating cell nuclear antigen (PCNA) was determined with immunohistochemistry using monoclonal antibody PC-10. RESULTS: ER positive HCC had higher incidence of single nodule (83.3%) and complete encapsulation (58.3%) compared to ER negative HCC (42.1% and 21.0%). The difference was significant (P < 0.05). In small liver cancer ER positive rate was 62.5% which was higher than 30.4% in large liver cancer (P < 0.05). The PCNA labeled index was (26.2 +/- 18.7)% in ER positive HCC and (43.6 +/- 32.0)% in ER negative HCC. The difference was significant (P < 0.05). CONCLUSION: The results suggest that ER positive HCC has less malignant biologic behavior and better prognosis than ER negative HCC.

Adult↗
PubMed1997

[The expression of mdm2 gene related to the invasiveness of human hepatocellular carcinoma].

OBJECTIVE: mdm2 gene was used as an index to study the molecular mechanism related to the invasiveness of human hepatocellular carcinoma (HCC). METHODS: The expression of mdm2 gene in 34 HCC samples and 19 paratumor liver tissues and the relationship between the expression of mdm2 gene and invasiveness of HCC were studied using reverse transcriptase-polymerase chain reaction (RT-PCR). RESULTS: The expression level of mdm2 gene (x +/- Sx) in HCC samples was higher than that in paratumor liver tissues (50.18% +/- 5.24% vs. 27.70% +/- 7.43%, P < 0.05). The expression level of mdm2 gene in HCC samples with invasiveness was higher than that in HCC samples without invasiveness (59.09% +/- 7.28% Vs. 37.87% +/- 6.37%, P < 0.05). However, significant difference in expression of mdm2 gene was not found between small and large HCC as well as between HCC with and without capsule. CONCLUSION: The expression of mdm2 gene was related to the invasiveness of HCC.

Carcinoma, Hepatocellular↗
PubMed1997

Study on small hepatocellular carcinoma and its extension.

This paper summarizes the "study on small hepatocellular carcinoma and its extension" in Liver Cancer Institute, Zhongshan Hospital of Shanghai Medical University during the past 25 years. The results indicated that it was an important approach to obtain long-term HCC survivors, of the 239 patients with 5-year survival, small HCC resection accounted for 51.4%. It was an effective approach to improve the prognosis of HCC in the entire series, the 5-year survival of inpatients treated in authors' institution was 4.8% in 1958-1970, 12.2% in 1971-1983, and 46.7% in 1984-1995; which were correlated to the increase proportion of small HCC resection in the series; it was more effective as compared to large HCC resection, the 5 year survival was 61.3% (n = 645) versus 33.6% (n = 950). Extensions of small HCC study included early detection and treatment of small recurrent HCC, of the 147 patients with re-resection, the 5-year survival was 48.9% calculated from the time of first resection. Another extension was conversion of large HCC into small HCC, using multimodality combination treatment, 72 out of the 663 patients with surgically verified unresectable HCCs have been converted to resectable, 5-year survival being 62.1%, which was comparable to that of small HCC resection. Studies on related basic aspect of small HCC such as cell origin of recurrence, and molecular aspect of small HCC, indicated that biological characteristics, particularly the tumor invasiveness, remained the key link for further prolong survival after small HCC resection. Recently, a "patient-like" human HCC metastatic model in nude mice has been established. Experimental interventions have also been tried. Clinical trials for prevention of recurrence after small HCC resection have shown preliminary encouraging results. However, the "cost-effectiveness" of screening, the invasiveness of HCC, the multicentric origin, the coexisted Child C cirrhosis, etc., remained great challenge.

Animals↗
PubMed1997

[Recombinant AAV-LMP-induced LMP specific cytotoxic response to autologous lymphoblastoid cell lines tranformed by Epstein-Barr virus].

Epstein-Barr virus is believed to be controlled in normal host by virus specific cytotoxic T lymphocytes (CTL). Although unable to eliminate EBV from the body, CTL seems to be essential in control of latently infected cells. Infusion of autologous EBV specific CTL, which can be produced in laboratory by separating lymphocytes from patients and stimulating them with EBV antigen, will provide an effective method of preventing and treating EBV-related diseases. We inserted the LMP gene of EB virus into an AAV vector pACP and packed it in Ad2 infected 293 cells by co-transfecting with plasmid Ad8, which produced the recombinant virus rAAV-LMP. The recombinant virus was used to infect stimulating cells and LMP antigen was expressed on the surface of these cells. Then the stimulating cells were irradiated and co-cultured with T lymphocytes. The EBV specific CTLs were obtained. The target cells were autologous LCLs from EBV-transformed B lymphocytes. The CTL activity was assayed by BLT activity method. The result indicated that all the four CTL strains could recognize and kill their target cells. This study has laid the technical basis for us to prevent and treat nasopharyngeal carcinoma in China with molecular biological methods.

Cell Line↗
PubMed1997

[Localization and expression of dopamine receptors in stomach and duodenum in rats].

UNLABELLED: Dopamine is an important neurotransmitter which may contribute to the regulation of gastrointestinal function, but its mechanism remains elusive. OBJECTIVE: The existence, localization and expression of dopamine receptor mRNAs in rat stomach and duodenum were examined by in situ hybridization. METHODS: The oligonucleotide probes were selected and synthesized according to the previous work. All the probes were labelled with alpha S35dATP using the terminal deoxynucleotide transferase, then were hybridized with the frozen, fixed preparation of rat stomach and duodenum. The density of silver granules were counted and analyzed by the image analysis computer system. RESULTS: It was found that all five subtypes of dopamine receptor mRNAs existed in the stomach and duodenum with greatly different expression. The distribution of dopamine mRNAs in the stomach were mainly localized in the lamina propria near the lamina muscularis mucosae and parallel to the longitudinal axis of the tract. Whereas, all five MRNAs were spread over the entire layer of the duodenal mucosa. With the image analysis system, abundant expressing levels of D5 and D4 mRNAs were documented unexpectedly. CONCLUSION: All these results suggest that dopamine produced its effect via dopamine receptors especially D5 subtype and D4 receptor might be act as a modulator.

Animals↗
PubMed1996

Correspondence of escape-turning behavior with activity of descending mechanosensory interneurons in the cockroach, Periplaneta americana.

Two bilaterally paired mechanosensory neurons that respond to antennal touch stimulation recently have been described in the cockroach Periplaneta americana. Here chronic recordings were used to describe the activity of these interneurons in relation to behavior. Parallel intra/extracellular recording experiments showed that both pairs of previously identified descending mechanosensory interneurons (DMIs) were activated after touch stimulation of the antennae and before initiation of escape. On a trial-by-trial basis, the bilateral pattern of their activity was correlated with sensory input and behavior: when one antenna was touched, the contralateral DMI axons displayed impulses earlier and in greater numbers than their ipsilateral homologs; turns were made toward the side with greater DMI activity, i.e., away from the touched antenna. One parameter of DMI activity (the bilateral difference in number of DMI impulses) was correlated with the angular amplitude of turning. In the absence of touch stimulation, unilateral electrical stimulation of a cervical connective via the chronic electrodes produced turning movements similar to natural escape turning and of appropriate directionality. These results support the hypothesis that neural activity in DMIs is involved in the control of antennal touch-evoked escape, and they provide a basis for a model of DMI specification of the direction of escape turning.

Animals↗
PubMed1996

Progression of coronary atherosclerosis is associated with a common genetic variant of the human stromelysin-1 promoter which results in reduced gene expression.

There is a common polymorphism in the promoter sequence of the human stromelysin-1 gene, with one allele having a run of six adenosines (6A) and the other five adenosines (5A). We have previously reported, in a 3-year follow-up study of patients with coronary atherosclerosis, that those patients who are homozygous for the 6A allele show a more rapid progression of the disease. In this study, we have investigated whether the 5A/6A promoter polymorphism plays a role in the regulation of stromelysin-1 gene expression. In transient transfection experiments, a stromelysin-1 promoter construct with 6A at the polymorphic site was found to express less of the chloramphenicol acetyltransferase reporter gene than a construct containing 5A. Electrophoretic mobility shift assay and DNase I footprinting revealed the interaction of one or more nuclear protein(s) with the DNA sequence at the 5A/6A polymorphic site. The binding of one of the nucleoprotein factors was more readily detectable with an oligonucleotide probe corresponding to the 6A allele as compared with a probe corresponding to the 5A allele. Replacing the core binding sequence with a random DNA sequence abolished the interaction between the nuclear protein(s) and the probe and also increased reporter gene expression in transiently transfected cells. Thus, the common 5A/6A polymorphism of the human stromelysin-1 promoter appears to play an important role in regulating stromelysin-1 gene expression and may be involved in the progression of coronary heart disease.

Alleles↗
PubMed1996

Regulation of the nisin operons in Lactococcus lactis N8.

The antibiotic peptide nisin produced by Lactococcus lactis is used as a food preservative due to its activity against spores and vegetative cells of Gram-positive bacteria. The post-translational maturation of this secreted peptide includes dehydration of serine and threonine residues, lanthionine formation and a proteolytic processing of 23 amino acids from the N-terminus. Mutations in the nisZ, nisB and nisP genes of the biosynthetic nisZBTCIPRK nisin operon were made by gene replacement or integration of a plasmid. The mutations caused a drastic decrease of the transcription from the promoters upstream of the nisZBTCIPRK and nisFEG operons resulting in loss of nisin production and nisin immunity. The transcription of the nisin operons and nisin immunity could be partially restored by adding nisin to the growth medium of the cells. Nisin induction of the mutant strains also increased the level of the putative immunity NisI protein. These results showed that the nisZBTCIPRK operon is positively autoregulated and that the nisFEG operon is in the same regulon.

Cloning, Molecular↗
PubMed1996

Acoustic nonlinearity parameter tomography for biological specimens via measurements of the second harmonics.

The acoustic nonlinearity parameter B/A is a new parameter in ultrasound tissue characterization. In this paper, on the basis of a theoretical analysis of finite amplitude ultrasonic wave propagation in fluidlike media, an experimental system for nonlinearity parameter tomography is developed. Using this system, the amplitude of the second harmonic wave cumulated in the propagation path of the primary wave is measured and the finite amplitude insert-substitution method is used in the conventional computer tomography (CT) technique. The filtered convolution algorithm is implemented using the amplitude of the second harmonic as the projection data, then the B/A tomography can be reconstructed. The B/A images for several biological samples are obtained. Besides, the image of porcine pathological liver tissue is studied and is compared with that of porcine normal liver tissue. These results show the potential applications of the nonlinearity parameter B/A in medical diagnosis.

Animals↗
PubMed1996

Repressor for the sn-glycerol 3-phosphate regulon of Escherichia coli K-12: primary structure and identification of the DNA-binding domain.

The nucleotide sequence of the glpEGR operon of Escherichia coli was determined. The translational reading frame at the beginning, middle, and end of each gene was verified. The glpE gene encodes an acidic, cytoplasmic protein of 108 amino acids with a molecular weight of 12,082. The glpG gene encodes a basic, cytoplasmic membrane-associated protein of 276 amino acids with a molecular weight of 31,278. The functions of GlpE and GlpG are unknown. The glpR gene encodes the repressor for the glycerol 3-phosphate regulon, a protein predicted to contain 252 amino acids with a calculated molecular weight of 28,048. The amino acid sequence of the glp repressor was similar to several repressors of carbohydrate catabolic systems, including those of the glucitol (GutR), fucose (FucR), and deoxyribonucleoside (DeoR) systems of E. coli, as well as those of the lactose (LacR) and inositol (IolR) systems of gram-positive bacteria and agrocinopine (AccR) system of Agrobacterium tumefaciens. These repressors constitute a family of related proteins, all of which contain approximately 250 amino acids, possess a helix-turn-helix DNA-binding motif near the amino terminus, and bind a sugar phosphate molecule as the inducing signal. The DNA recognition helix of the glp repressor and the nucleotide sequence of the glp operator were very similar to those of the deo system. The presumptive recognition helix of the glp repressor was changed by site-directed mutagenesis to match that of the deo repressor or, in a separate construct, to abolish DNA binding. Neither altered form of the glp repressor recognized the glp or deo operator, either in vivo or in vitro. However, both altered forms of the glp repressor were negatively dominant to the wild-type glp repressor, indicating that the inability to bind DNA with high affinity was due to alteration of the DNA-binding domain, not to an inability to oligomerize or instability of the altered repressors. For the first time, analysis of repressors with altered DNA-binding domains has verified the assignment of the helix-turn-helix motif of the transcriptional regulators in the deoR family.

Amino Acid Sequence↗
PubMed1996

Accuracy of sonography in the evaluation of calf deep vein thrombosis in both postoperative surveillance and symptomatic patients.

OBJECTIVE: The purpose of this study was to determine the accuracy and to assess the interobserver variability of compression sonography (CS) in detecting isolated calf deep vein thrombosis (DVT) in postoperative and symptomatic patients without clinical or contrast venographic indication of previous lower extremity DVT. SUBJECTS AND METHODS: A prospective double-blinded study was undertaken on 287 consecutive legs using contrast venography (CV) as the gold standard. One hundred seventy-nine legs were from the postoperative group, and 108 legs were from the symptomatic group. The CS technique was used to diagnose DVT, and color Doppler imaging was used only as a road map. Calves were examined while the patient was sitting. Also, interobserver agreement was measured in the CS evaluation of calf veins of another group of 54 symptomatic legs. RESULTS: Forty (22%) CVs and 13 (7%) CS examinations for calf assessment were indeterminate in the postoperative group as compared with 33 (30%) and 10 (9%) in the symptomatic group. The sensitivity, specificity, negative predictive value, and positive predictive value of CS in detecting calf DVT with or without extension to above-the-calf veins were 92% (confidence interval [Cl], 82-100%), 100%, 98% (Cl, 95-100%), and 100%, respectively, in the postoperative group and 86% (Cl, 72-100%), 96% (Cl, 90-100%), 94% (Cl, 87-100%), and 90% (Cl, 77-100%), respectively, in the symptomatic group. The sensitivity of CS was 92% (Cl, 81-100%) in the postoperative and 88% (CL, 65-100%) in the symptomatic group with isolated calf DVT. Of all calf muscular branch DVTs, 52% were detected by CS alone as compared with 21% seen on CV alone. The kappa value for the CS assessment of isolated calf vein DVTs was 0.60. CONCLUSION: Sonography is a highly accurate test with acceptable reproducibility for the detection of DVT in calf veins in both postoperative and symptomatic patients. Technically adequate calf assessment can be achieved in the majority of patients if the calf examination is performed with the patient sitting.

Adult↗
PubMed1996

[The postnatal changes of follicle-stimulating hormone receptor mRNA level in rat testis].

It was found in this study that the follicle-stimulating hormone receptor (FSHR) mRNA levels varied between days 2 and 60. The FSHR mRNA rised slightly in the neonatal rat testis and then declined. In the prepuberty the content of FSHR mRNA remained at a Constant level. During the puberty the FSHR mRNA increased to its highest level on days 25 and finally it rised again after days 40.

Animals↗
PubMed1996

[Alteration of mRNA transcripts of rat Sertoli cell secreted proteins and Leydig cell LH/CG-R protein following glycosides of Tripterigium Wilfordii Hook administration].

Our studies were undertaken to assess the male antifertility mechanism of the total glycosides extracted from Tripterigium Wilfordii Hook. f. (GTW). In experimental group I, GTW was given by gastric gavage at a dose of 30 mg/kg per day for 35 days. In experimental group I, GTW was given in the same way at a dose of 10 mg/kg per day for 49 days. The transcripts level analysis indicated that in all the experimental groups ABP, SGP-2 and LH/CG-R mRNA were increased. Two ABP and two LH/CG-R mRNA transcripts with respective molecular sizes of 1.7 kb, 2.3 kb and 1.2 kb, 4.4 kb were identified. ABP and LH/ CG-R mRNA with 1.7 kb and 1.2 kb increased, while those with 2.3 and 4.4 kb remained unchanged. In addition, the changes of different proteins at the mRNA level were shown to be GTW dose-dependent. The morphological features of germ cell degeneration and appearance of germ cells in tubular lumen suggest that the increases in transcripts level of three proteins in testis may not be directly associated with the effect of GTW. The question whether GTW interfere with the function of sertoli cells and leydig cells would be study.

Androgen-Binding Protein↗
PubMed1996

Crystal structure of (L-Arg)-B0 bovine insulin at 0.21 nm resolution.

The crystal structure of (L-Arg)-B0 bovine insulin has been determined, using data to 0.21 nm and atomic parameters of 2Zn porcine insulin as a starting model, by the difference. Fourier method, the restrained least square method and X-PLOR package, interspersed with careful review of the electron density, to a final R-factor of 0.182 and r.m.s. deviation of 0.002 2 nm for the bond lengths and 4.3 degrees for the bond angles. The electron densities of additional (L-Arg)-B0 residues to B-chain N-terminus of two monomers in each asymmetric unit are very clear. The crystallographic micro-environment of the N-terminus of the B-chain is different from that of rhombohedral 2-zinc insulin.

Crystallization↗
PubMed1995

A motion tracking system for simultaneous recording of rapid locomotion and neural activity from an insect.

We have adapted techniques for studying the locomotion of tethered insects to analysis of rapid directional movements such as escape behavior. We describe here a computer-based motion tracking system that allows an animal to turn and run as rapidly as it does under free-ranging conditions, and that samples fast enough to accurately reconstruct the movements. Furthermore, we have designed chronic electrodes that allow for simultaneous extracellular recording of the activity of interneurons related to behavior. We used this system to record the escape response of tethered cockroaches, Periplaneta americana, and compared the data with those obtained from high-speed videographic analysis of the same animals under free-ranging conditions. In the motion tracking system, animals were normally responsive to sensory input, and expressed directional escape turning responses. This system allows details of an entire escape response (initial turn and subsequent running) to be quantified. These behavioral details can now be correlated with the discharge of key interneurons on a trial-by-trial basis.

Animals↗
PubMed1995

Preliminary report: genetic variation in the human stromelysin promoter is associated with progression of coronary atherosclerosis.

Stromelysin is a member of the family of metalloproteinases that degrade extracellular matrix. In situ hybridisation and histopathological studies suggest that stromelysin activity may be important in the connective tissue remodelling processes associated with atherogenesis and plaque rupture. Single strand conformation polymorphism analysis identified a common polymorphism in the stromelysin gene promoter located 1171 bp upstream from the start of transcription in which one allele has a run of six adenosines (6A) and another has five adenosines (5A). 72 men with coronary heart disease, were genotyped. They were participants in the St Thomas' Atherosclerosis Regression Study who were randomised to receive usual care (UC), dietary intervention (D), or diet plus cholestyramine (DC), with angiography at baseline and at 39 months. In these patients the frequency of the 5A allele was 0.49 (95% CI from 0.41 to 0.57) and was not significantly different from that in a sample of 354 healthy UK men. In the UC group, patients who were homozygous for the 6A allele showed greater progression of angiographic disease than those with other genotypes: the minimum absolute width of coronary segments decreased by 0.04 (SEM 0.10) mm for 5A5A, 0.20 (0.07) mm for 5A6A, and 0.67 (0.19) mm for 6A6A (P < 0.01). The findings were similar but slightly less significant for the change in mean absolute width of coronary segments (P < 0.05). No significant associations were seen in patients in the D or DC groups. In data pooled from the three treatment groups, the 6A6A genotype was significantly associated with greater progression of coronary atherosclerosis than other genotypes in patients with baseline percentage diameter stenosis less than 20% (P < 0.05), but not in those with baseline percentage diameter stenosis greater than or equal to 20%. These results provide the first evidence of a link between genetic variation in stromelysin and progression of coronary atherosclerosis and support the hypothesis that connective tissue remodeling mediated by metalloproteinases contribute to the pathogenesis of atherosclerosis.

Base Sequence↗