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S Cai

Publications and source records attributed to S Cai.

At least 163 records · Page 9Linked to original sources
PubMed1997

[Relationship between nm23-H1 expression and lymph node metastasis and prognosis in cervical cancer].

OBJECTIVE: To investigate the expression of nm23-H1 in cervical carcinoma and its significance. METHODS: Expression of nm23-H1 was examined by immunohistochemical method in 39 cases of adenocarcinoma and 39 cases of squamous cell carcinoma of the uterine cervix. The relationship between expression of nm23-H1 and clinic-pathologic factors and prognosis was analyzed by chi-square test. RESULTS: Positive staining rate of nm23-H1 was 44.6% in adenocarcinoma and 39.2% in squamous cell Carcinoma. The positive staining rate of nm23-H1 in stage I and II adenocarcinoma was 61.1% and 28.6% respectively (P = 0.044); in patients with recurrence nm23-H1 positive rate was lower than that in patients without recurrence (21.5% vs 56%, P = 0.39); in patients with lymph node negative, nm23-H1 positive staining was more than that in patients with lymph node positive (52% vs 28.6%), however, this difference was not statistically significant (P = 0.162). None of 14 cases of lymph node metastasis was strong positive stainig, whereas 7 of 25 without lymph node metastasis were demonstrated to have strong positive staining (P = 0.031). The 5-year survival rate in negative staining group was lower than that in the positive staining group (52.5% vs 82.4%, P = 0.042). In squamous cell carcinoma there was no statistically significant relationship between nm23-H1 expression and clinic-pathologic factors and prognosis. CONCLUSIONS: nm23-H1 expression was associated with biologic behavior in cervical adenocarcinoma.

Adenocarcinoma↗
PubMed1997

[Investigation on the viscoelastic properties of hepatocytes and their relavances to cytoskeleton structure].

Using micropipette aspiration technique, the authors investigated the viscoelastic properties of human fetal hepatocytes (HFH) and hepatocellular carcinoma (HCC) cells. And further, the effects of two cytoskeleton interferents, cytochalasin D and colchicine on the viscoelastic properties of HFHs were investigated. The results showed: the elastic coefficients K1 and K2 of HCC cells were significantly higher than those of HFHs; the action of cytochalasin D led to an obvious decrease in elastic coefficients K1, K2 as well as the viscous coefficient mu of HFHs; under the action of colchicine, the K1 value of HFHs increased while the K2 and mu values decreased obviously or tended to decrease. A brief discussion was presented about these results.

Carcinoma, Hepatocellular↗
PubMed1996

Evidence from incorporation experiments for an anionic channel of small conductance at the apical membrane of the rabbit distal tubule.

Many of the hormone-regulated ion transport processes in distal nephron involve transcellular pathways which require a passive entry of ions at the apical membrane of the distal tubule cells. To investigate molecular mechanisms underlying the ionic permeability of the distal tubule apical membrane, a study was undertaken in which vesicles prepared from apical membranes from isolated rabbit distal tubules were fused onto a planar lipid bilayer. These experiments led to the identification of several ionic channels including a Cl(-)-permeable channel of 14 pS with a Na+ over Cl- permeability ratio, PNa/PCl < 0.09. The open channel probability (Po) showed a weak voltage dependency with Po increasing slightly at negative potential values (intracellular (trans) relative to extracellular (cis) for right-side-out vesicles). Channel activity was inhibited by NPPB at high concentrations (> 100 microM) and by DIDS (300 microM). A small inhibitory effect was also observed in the presence of DPC at concentrations ranging from 200 microM to 500 microM. The presence of SO4(2-) (32 mmol/l) in the trans solution caused a complete inhibition of channel activity, but no modification of channel behaviour was observed with the non-selective channel blocking agent gadolinium (Gd3+) at 100 microM. Finally, addition of the catalytic subunit of protein kinase A into the trans chamber (60 U/ml to 80 U/ml) led to an increase in channel activity characterized by a greater number of active channels coupled to an increase of the individual channel open probability. The action of the protein kinase A could be cancelled by the addition of a non specific protein phosphatase, such as alkaline phosphatase. Our results suggest that the apical membrane of the rabbit distal tubule contains a Cl- permeable channel of small conductance the activity of which may be modulated by hormones linked to the adenylate cyclase pathway.

4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid↗
PubMed1996

Vaccination with herpes simplex virus type 1 glycoprotein K impairs clearance of virus from the trigeminal ganglia resulting in chronic infection.

Following primary ocular infection, HSV-1 establishes a latent infection in the trigeminal ganglia with the complete absence of detectable infectious virus. Recently, we showed that vaccination of BALB/cJ with HSV-1 glycoprotein K (gK), but not other HSV-1 glycoproteins, significantly exacerbated the severity of HSV-1-induced ocular disease and herpetic dermatitis (H. Ghiasi et al. J. Virol. 68, 2347-2354, 1994). We now report that prior vaccination with gK blocked viral clearance from trigeminal ganglia until at least Day 56 postinfection, resulting in a chronic infection. The significance of this novel finding with respect to potential harmful complications associated with the immune response to gK is discussed.

Animals↗
PubMed1996

The UL3 open reading frame of herpes simplex virus type 1 codes for a phosphoprotein.

Based on sequence analysis, the protein encoded by the UL3 open reading frame (ORF) of herpes simplex virus type 1 (HSV-1) was predicted to contain an N glycosylation site and to be a glycoprotein. To determine if this prediction was correct, we cloned and expressed the DNA encoding the complete sequence of the UL3 ORF in a baculovirus expression system. Western blotting was done using polyclonal antibody raised against synthetic UL3 peptides. Two major baculovirus-UL3 expressed protein bands with apparent molecular weights of 30 kDa and 31 kDa, and two minor protein bands with apparent molecular weights of 29 kDa and 33 kDa were detected. None of the expressed UL3 protein species were susceptible to tunicamycin treatment, suggesting that they were not N-linked glycosylated. Cell fractionation studies indicated that the UL3 protein was localized in the cytoplasmic and nuclear portion of the cells, rather than the cell membrane, again suggesting a lack of glycosylation. In contrast, the baculovirus expressed UL3 protein was phosphorylated as judged by 32Pi-labeling. Immunoprecipitation followed by SDS-PAGE demonstrated a single 32Pi-labeled UL3 related band with an apparent molecular weight of 33 kDa, indicating that the UL3 protein was a phosphoprotein. Antibodies produced in mice vaccinated with baculovirus-UL3 protein reacted with two UL3 related HSV-1 bands on Western blots. These protein bands had apparent molecular weights of 27 and 33 kDa and presumably represent the unphosphorylated and phosphorylated forms of UL3.

Animals↗
PubMed1996

Effects of halothane and isoflurane on bradykinin-evoked Ca2+ influx inbovine aortic endothelial cells.

BACKGROUND: Volatile anesthetics, such as halothane and isoflurane, have been reported to affect the endothelium mediated relaxation of vascular smooth muscle cells. Because the activity of the constitutive nitric oxide synthase in endothelial cells depends on the availability of intracellular Ca2+, there is a definite possibility that the observed inhibitory effect of volatile anesthetics involves an action on the agonist-evoked internal Ca2+ mobilization and/or Ca2+ influx in these cells. Therefore, a study was undertaken to determine how halothane and isoflurane affect the Ca2+ signalling process in vascular endothelial cells. METHODS: The effect of halothane and isoflurane on the Ca2+ response to bradykinin of bovine aortic endothelial (BAE) cells was investigated using the fluorescent Ca2+ indicator fura-2. Halothane or isoflurane was applied either to resting cells or after bradykinin stimulation. The agonist-evoked Ca2+ influx in BAE cells was estimated by measuring either the rate of fura-2 quenching induced by Mn2+ or the increase in cytosolic Ca2+ concentration initiated after readmission of external Ca2+ after a brief exposure of the cells to a Ca(2+)-free external medium. The effects of halothane on cell potential and intracellular Ca2+ concentration were measured in cell-attached patch-clamp experiments in which a calcium-activated K+ channel and an inward rectifying Ca(2+)-independent K+ channel were used as probes to simultaneously monitor the intracellular Ca2+ concentration and the cell transmembrane potential. In addition, combined fura-2 and patch-clamp cell-attached recordings were carried out, to correlate the variations in internal Ca2+ caused by halothane and the activity of the Ca(2+)-dependent K+ channels, which are known in BAE cells to regulate intracellular potential. Finally, a direct action of halothane and isoflurane on the gating properties of the Ca(2+)-activated K+ channel present in these cells was investigated in patch-excised inside-out experiments. RESULTS: The results of the current study indicate that the initial Ca2+ increase in response to bradykinin stimulation is not affected by halothane, but that pulse applications of halothane (0.4-2 mM) or isoflurane (0.5-1 mM) reversibly reduce the sustained cytosolic Ca2+ increase initiated either by bradykinin or by the Ca2+ pump inhibitor thapsigargin. In addition, halothane appeared to dose-dependently inhibit the Ca2+ influx evoked by bradykinin, and to cause, concomitant to a decrease in cytosolic Ca2+ concentration, a depolarization of the cell potential. Halothane failed, however, to affect internal Ca2+ concentration in thapsigargin-treated endothelial cells, which were depolarized using a high K+ external solution. Finally, halothane and isoflurane decreased the open probability of the Ca(2+)-dependent K+ channel present in these cells. CONCLUSIONS: These observations suggest that the effects of halothane and isoflurane on Ca2+ homeostasis in BAE cells reflect, for the most part, a reduction of the thapsigargin- or bradykinin-evoked Ca2+ influx, which would be consequent to a cellular depolarization caused by an inhibition of the Ca(2+)-dependent K+ channel activity initiated after cell stimulation.

Anesthetics, Inhalation↗
PubMed1996

[Growth inhibitory effect of retinoic acid in human breast cancer cells correlates with retinoic acid receptor alpha (RAR alpha) expression].

The relationship between the effect of retinoic acid (RA) on the growth of breast cancer cell and their estrogen receptor (ER) status as well as the relationship between RA effect and the expression of retinoic acid receptorsd (RAR alpha) were studied by cell growth assay, Northern Blot and gene transfection. It was found that RA could only inhibit the growth of ER-positive but not ER-negative breast cancer cells. RAR alpha mRNA level was significantly higher in ER-positive breast cancer cell lines than that in ER-negative breast cancer cell line. The expressions of other subtypes of RAR in ER-positive cells were not significantly different from those in ER-negative ones. When, RAR alpha cDNA was introduced and ixpressed in RA-resistant, ER-negative MDA-MB-231 breast cancer cell line, its growth was strongly inhibited by RA. These results indicate that RAR alpha plays a major role in the retinoi-dmediated inhibition of growth in human breast cancer cells.

Antineoplastic Agents↗
PubMed1996

Anchoring of c-myc on nuclear matrix proteins in process of mouse thymic T lymphocyte proliferation induced by ConA.

Isolation and characterization of functional nuclear matrix proteins involved in DNA anchoring and gene expression is one of the major subjects of current nuclear matrix research. Southwestern blotting (DNA-protein hybridization) was applied to studying the anchoring of c-myc on the nuclear matrix proteins in mouse thymic T lymphocytes. The results showed that c-myc bound to the lamin, p34 and p36 nuclear matrix proteins specifically. In the process of mouse thymic PNA-T lymphocytes proliferation induced by ConA, the anchoring of c-myc on p34 and p36 nuclear matrix proteins changed dynamically.

Animals↗
PubMed1996

[Botanical origin of commercial samples of traditional Chinese drug xixin (Herba Aasari)].

It has been found out that amony the 158 samples of commercial drug. Xixin (Herba Asari) collected from 28 provinces/cities of China, only three guarters are derived from the species specified in the Chinese Pharmacopoeia and the rest are not. One hundred and eleven samples are derived from Asarum heterotropoides var. mandshuricum and are presently used in 26 provinces/cities, 25 samples are derived from A. himalaicum and used in 10 provinces, the other 22 samples are derived from 9 species such as A. sieboldii, A. forbesii, etc.

China↗
PubMed1995

Study on electrocution death by low-voltage.

Seven cases of electrocution death by low voltage (< 80 V) were studied. Autopsy was carried out and the death scene was investigated. The conditions for low-voltage electrocution death, the state of the victim at the time of electrocution, postmortem examination and the nature of the electricity is discussed. It was pointed out that low-voltage electrocution was related to the nature of electricity, individual characteristics and environment conditions.

Accidents, Occupational↗
PubMed1995

A 31-mutation assay for cystic fibrosis testing in the clinical molecular diagnostics laboratory.

We devised a set of allele-specific probes to detect simultaneously 31 known cystic fibrosis mutations using PCR and the reverse dot blot detection format. The assay has been implemented in a clinical setting to the screening of over 750 individuals. Of these 102 Caucasians, 20 Hispanics and 1 Indian patient were affected with cystic fibrosis. The mutation detection rate in the 204 Caucasian and 40 Hispanic CF chromosomes was respectively, 88% and 85%. The availability of the probe sequences to CF screening laboratories should allow implementation of this assay in a clinical setting and comparison of its mutation typing rate among different centers.

Alleles↗
PubMed1995

Granulocyte-macrophage colony-stimulating factor and interleukin-4 differentially regulate the human tumor necrosis factor-alpha promoter region.

Regulation of TNF-alpha promoter activity by IL-2, IFN-gamma, GM-CSF, and IL-4 was examined in the U937 macrophage cell line and the MLA 144 T cell line. Using a transient transfection system, the full-length TNF-alpha promoter was examined for response to these cytokine signals. Only GM-CSF was able to consistently induce a twofold activation of the TNF-alpha promoter in the U937 cell line. GM-CSF activation of the promoter region was further analyzed using a series of 5' truncations and site mutations of the AP-1, AP-2, and CRE sites of the promoter. The GM-CSF activation mapped to the region contained within the 95 base pairs upstream from the transcription start site (TSS) with the AP-2 site as a putative cis-acting sequence. IL-4 profoundly inhibited both basal and phorbol ester-induced TNF-alpha promoter activity as well as protein production. Promoter inhibition by IL-4 required the 95-bp basal promoter sequence.

Animals↗
PubMed1995

Vaccination of mice with herpes simplex virus type 1 glycoprotein D DNA produces low levels of protection against lethal HSV-1 challenge.

The herpes simplex virus type 1 (HSV-1) glycoprotein D (gD) gene was inserted into vectors pSVL or pRc/CMV under control of the SV40 late promoter or the human cytomegalovirus major immediate-early promoter, respectively. Intramuscular injection of mice with these gD-containing plasmids appeared to induce low levels of serum anti-gD antibody, as judged by the appearance of low levels of anti-HSV-1-neutralizing antibody and anti-gD ELISA responses in the serum of gD-DNA-vaccinated mice. As previously reported in other virus systems, vaccination with vector DNA also induced ELISA and neutralizing antibody titers. However, these titers were lower than those induced by the gD-containing plasmids. The ELISA and neutralization titers induced by the vectors appeared to be non-specific rather than directed at specific HSV-1 proteins, since serum from mice vaccinated with plasmid-gD immunoprecipitated significant amounts of gD from extracts of HSV-1-infected cells, while serum from mice vaccinated with vectors was unable to immunoprecipitate gD or any other obvious HSV-1 proteins. Neither pSVL-gD nor pRc/CMV-gD induced detectable lymphocyte proliferative or CTL responses. Vaccination with pSVL-gD provided a significant (P = 0.04, Fisher's exact test), but low level of protection against lethal challenge with HSV-1. Vaccination with pRc/CMV-gD also appeared to provide a low level of protection against challenge, that was statistically significance at the 10% level (P = 0.054, Fisher's exact test). Reports from numerous laboratories (including ours) have shown that vaccination with recombinantly expressed gD can provide very high levels of protection against HSV-1 lethal challenge. Thus, the results reported here suggest that vaccination with HSV-1 gD-DNA is not yet a useful alternative to a gD subunit vaccine.

Animals↗
PubMed1995

Smooth muscle contractility is modulated by myosin tail-S2-LMM hinge region interaction.

The functional significance of two major smooth muscle myosin isoforms, which differ in the nonenzymic COOH-terminal tail region, is not known. We report here that a 13-amino acid peptide, which mimics a region of the tail unique to the SM1 myosin isoform, inhibits contraction velocity in permeabilized smooth muscle. This peptide is shown to bind to the S2-light meromyosin (LMM) hinge region of myosin using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, photoaffinity labeling, and immunoelectron microscopy. Our results suggest that novel intermolecular contacts between the tail and S2-LMM hinge regions of adjacent myosin molecules in the thick filament may modulate contractility and provide a basis for distinct isoform function.

Animals↗
PubMed1995

Cadmium exposure among residents in an area contaminated by irrigation water in China.

River water used to irrigate arable land in Dayu County, Jiangxi Province, China, is polluted with cadmium from tailings and the wastewater of tungsten ore dressing plants. From information about the date on construction of ore dressing plants and an analysis of the annual growth rings of trees, we deduced that local residents have been exposed to cadmium for at least 25 years. Cadmium exposure was estimated based on a meal survey, which indicated that 99.5% of the oral cadmium intake came from rice and vegetables grown locally. The average oral intake of cadmium was calculated to be 367-382 micrograms/ day. Smokers had additional exposure from locally grown cadmium-containing tobacco. Cadmium concentrations in samples of urine (11 micrograms/g creatinine), blood (12 micrograms/l) and in the hair (0.11 microgram/g) of persons in the exposed area were high. The cadmium exposure lies in a range that can be considered to cause adverse renal effects in the long term.

Air Pollutants↗
PubMed1995

[A clinical report of refractory carcinoma of ovary and fallopian tube treated with taxol].

From September 1993 through March 1994, 30 cases of refractory carcinoma of the ovary and Fallopian tube were treated with Taxol. Complete response was seen in 4 and partial response in 8 cases with a response rate of 40%. The average length of remission was 5 months in CR and 3.9 months in PR. The major toxic side effect was decrease in total white cell count and in neutrophil count. Apart from flushing of face during Taxol infusion in 6 patients, no other allergic reaction was observed. Gastrointestinal, neurologic, liver and renal toxicities were mild. Taxol is a drug of choice in the treatment of patients with cancer of the ovary and Fallopian tube who are resistant to conventional chemotherapy.

Adenocarcinoma↗