Search PubMed⌕ Search

Biomedical subjects

S He

Publications and source records attributed to S He.

At least 271 records · Page 15Linked to original sources
PubMed1995

Increased blood flow resistance in placental circulation and levels of plasminogen activator inhibitors types 1 and 2 in severe preeclampsia.

To study whether increased resistance in the placental circulation changes the plasma levels of plasminogen activators types 1 and 2 (PAI-1 and PAI-2) in severe preeclampsia, the levels of PAI-1 activity and PAI-2 antigen were determined in 33 severely preeclamptic and 22 normal pregnant women during gestational weeks 24-35. In the preeclampsia group, the Pulsatility Index (PI) of the umbilical artery was investigated with Doppler ultrasound. The levels of PAI-1 activity were higher (P < 0.01) whereas those of PAI-2 antigen were lower (P < 0.01) in the preeclampsia group than in the normal pregnancy group. The patients with abnormally high PI (high PI group) had increased PAI-1 levels (P < 0.05) and unchanged PAI-2 levels (P > 0.05), compared with those with normal PI (normal PI group). The levels of PAI-1 were positively correlated to the PI values during pregnancy weeks 34-35 only in the high PI group (r = 0.88, P < 0.05). In conclusion, high resistance in the placental circulation elevates plasma PAI-1 activity levels but does not influence PAI-2 antigen levels.

Female↗
PubMed1995

Increased concentrations of lactate dehydrogenase in pregnancy with preeclampsia: a predictor for the birth of small-for-gestational-age infants.

Lactate dehydrogenase (LDH), alanine aminotransferase (ALT) and aspartate aminotransferase (AST) concentrations and platelet counts were measured in 26 normal pregnant women and 51 preeclamptic women. In the normal-pregnancy group, no significant changes were found in the results of these tests. In the preeclampsia group, ALT and AST concentrations were not significantly higher than those in normal pregnancy, but the LDH concentrations increased and the platelet counts decreased significantly through the pregnancy. The increases in LDH did not correlate with changes in ALT or AST. Preeclamptic women with small-for-gestational-age (SGA) infants had significantly higher LDH concentrations than those in the appropriate-for-gestational-age (AGA) group, but ALT and AST concentrations did not increase significantly. As reasons for the LDH increase in our subjects, liver damage was excluded and more active glycolysis in addition to severe cell damage due to chronic anoxemia were inferred. It is suggested that an increase in LDH is predictive of SGA infants in preeclamptic pregnancy, especially in those with normal liver function.

Alanine Transaminase↗
PubMed1995

SV40-immortalized and primary cultured human retinal pigment epithelial cells share similar patterns of cytokine-receptor expression and cytokine responsiveness.

Retinal pigment epithelial (RPE) cells produce and respond to a variety of cytokines; however, molecular and biochemical studies are restricted by the limited access to large numbers of pure cells and the variability associated with different donor sources. Despite success in establishing primary human RPE (HRPE) cell cultures, the inability to sustain consistent proliferation rates and morphology over several passages remains a concern. This problem was approached by using an immortalized line of simian virus (SV)40 transformed fetal HRPE cells (SVRPE). Cytokine production, receptor expression and responsiveness in the SVRPE cell line was analyzed to determine the usefulness of this model for studying HRPE-cytokine interactions. Using reverse transcriptase polymerase chain reaction (RT-PCR), HRPE and SVRPE cells demonstrated an identical pattern of interleukin-1 receptor (IL-1R), IL-2R (alpha sub-unit), IL-6R, interferon (IFN)-gamma R and tumor necrosis factor-alpha (TNF)R p55 expression. No amplification products for TNFR p75 or granulocyte/macrophage colony stimulating factor (GM-CSF)R were demonstrated in either population. IFN-gamma stimulation induced surface human leukocyte antigen (HLA)-DR in both SVRPE and HRPE, while TNF treatment induced surface expression of intercellular adhesion molecule (ICAM)-1 on SVRPE and upregulated ICAM from basal levels on HRPE. Both cell types showed amplification products for interleukin (IL)-1 beta, IL-6 and transforming growth factor (TGF)-beta 1 using RT-PCR. The bioassays demonstrated that both populations of unstimulated cells constitutively secrete very low levels of TGF-beta and no IL-6.(ABSTRACT TRUNCATED AT 250 WORDS)

Base Sequence↗
PubMed1995

[A study on expression of epidermal growth factor receptor in pleomorphic adenoma of lacrimal gland].

Expression of epidermal growth factor (EGF) receptor was examined in 32 cases of pleomorphic adenoma of lacrimal gland by means of an immunohistochemical method. While normal lacrimal glands were all negative for the antigen, EGF receptor was positive in 10 pleomorphic adenomas and the positive staining was mainly limited in the tumor cells in trabecular or duct-like arrangement or squamous metaplastic epithelium. These data suggest that the expression of EGF receptor be significantly higher in pleomorphic adenoma than in normal lacrimal gland, and also suggest that EGF receptor be expressed in the neoplastic cells which are considered to be of duct origin.

Adenoma, Pleomorphic↗
PubMed1995

Systolic anterior motion of the mitral valve in hypertrophic cardiomyopathy: an in vitro pulsatile flow study.

Hypertrophic cardiomyopathy, or HCM, is a relatively common disease which results in the hospitalization of more than 13,000 patients every year. It is characterized by a thickening of the interventricular septum and by systolic anterior motion, or SAM, of the mitral valve, which occurs when the distal tip of the mitral leaflets contacts the hypertrophied septum during systole and obstructs the left ventricular outflow tract. Using an in vitro pulsatile flow model of the left ventricle, the objective of the study was to investigate the relationship between the ventricular flow field and the mechanism of SAM and to specifically address the hypothesis that papillary muscle displacement can alter left ventricular flow patterns and create drag forces that can initiate SAM. Flow visualization revealed the presence in the ventricle of a large organized recirculation region throughout diastole. Besides maintaining the mitral leaflets close to the posterior wall, normally positioned papillary muscles also caused the diastolic vortex to help the mitral valve close near the posterior wall while simultaneously prepositioning the upcoming systolic outflow stream close to the septum, thereby minimizing the flow forces acting on the mitral valve. In contrast, the anterior displacement of the papillary muscles moves the entire mitral apparatus into the outflow tract. It also reverses the direction of the recirculating diastolic flows: The diastolic vortex now promotes the initiation of SAM by displacing the closing mitral leaflets anteriorly and by positioning the systolic outflow stream close to the posterior wall. These events lead to the creation of form drag forces as the systolic flow impacts the posterior side of the mitral leaflets, initiating SAM.

Cardiac Output↗
PubMed1995

[Preliminary studies on protective effects of selenium on human fetal hepatocyte in vitro injured by lipid peroxidation].

A selenium protection model of human fetal hepatocyte in vitro injured by lipid peroxidation was established. It was found that survival rate and secretion of albumin of the injured cells decreased, and release of alanine transaminase (ALT) and its activities in the cells increased, as compared with those in controls, with a very significant difference. Under electronic microscope, ultrastructure of the injured cells appeared obscure, their membrane and membranous organella swelling, or membranous structure breaking. Injuries mentioned above in cells pre-treated with selenium were obviously decreased and activities of glutathione peroxidase increased. But protective effects of selenium supplement were weaker. It suggested that preventive supplement with selenium could reduce injury to human hepatocyte caused by lipid peroxidation.

Cell Survival↗
PubMed1995

[A comparison study of various anterior capsulectomies].

The incidences of anterior capsular radial tears occurring in different capsulectomies performed on rabbit eyes under standardized conditions were compared. The eyes were randomly divided into 4 technique groups: (1) can opener, (2) capsulopuncture, (3) linear capsulotomy and (4) continuous circular capsulorhexis (CCC). The results demonstrated that the CCC technique has more advantages in comparison with other three groups. With the nuclear expression technique used in this study, no radial tears occurred with the CCC technique, whereas radial tears occurred in 100% of cases treated with other three techniques.

Animals↗
PubMed1995

[Cultured human retinal pigment epithelial cell produced and secreted epidermal growth factor: its bioactivity and clinical significance].

The epidermal growth factor bioactivity from cultured primary human and monkey retinal pigment epithelial (RPE) cell systems was detected by using the radioreceptor assay. We report that the cultured human and monkey RPE cells produce and secrete the EGF bioactively to the media as demonstrated by radioreceptor binding assay. The EGF bioactivities secreted by human and monkey RPE cells were at peak of 48 hours (human RPE cells secreted 2.11 +/- 0.46 ng/ml vs monkey RPE was 1.56 +/- 0.12 ng/ml) in the serum-free media. The results indicate that the RPE is one of important sources for EGF in the eye. The RPE cells may play much important roles in the development of proliferative retinal diseases through the autocrine or paracrine mechanism. This new discovery will be helpful to elucidate the pathogenesis of proliferative retinal diseases and also provide an important basis for the treatment of such diseases.

Animals↗
PubMed1995

[Medicinal plant resources of Berberis L. in Guizhou province].

Based on field investigation and identification of 19 species and one variety of medicinal plant of Berberis produced in Guizhou Province, it has been found out that among these species 3 is found to be new ,4 species and one variety are discovered for the first time in Guizhou province. Geographical distribution, perpendicular distribution and medicinal uses of these species are spelled out and a key for their identification is given.

China↗
PubMed1995

Cloning of a gene encoding the precursor of nisin by PCR.

The structural gene for the precursor of nisin was synthesized by polymerase chain reaction and then cloned in pUC18. The nucleotide sequence of the cloned precursor nisin gene was determined by dideoxy termination method. The sequence data obtained agreed with those of precursor nisin genes isolated by other workers from different Lactococcus lactis strains.

Amino Acid Sequence↗
PubMed1994

Lovastatin induces growth inhibition and apoptosis in human malignant glioma cells.

The competitive HMG-CoA reductase inhibitor lovastatin has been shown to suppress growth and induce morphological changes in a variety of non-glioma tumor cell lines. This study assesses the effects of this agent on the growth and survival of the human malignant glioma cell lines A172 and U87-MG. The response to the drug was investigated using a cell proliferation assay which revealed significant dose-dependent growth inhibition. Treatment with as little as 100 nM lovastatin over a period of 72 hours led to DNA degradation into nucleosome-sized fragments characteristic of apoptosis. Our data suggest that HMG-CoA reductase inhibitors such as lovastatin merit further investigation as potential therapeutic agents for the treatment of malignant gliomas.

Apoptosis↗
PubMed1994

Interleukin 4 receptor signaling in human monocytes and U937 cells involves the activation of a phosphatidylcholine-specific phospholipase C: a comparison with chemotactic peptide, FMLP, phospholipase D, and sphingomyelinase.

Interleukin 4 (IL-4) diminishes cytokine activation of human macrophage. IL-4 binding to monocyte IL-4R is associated with protein kinase C (PKC) translocation to a nuclear fraction. The cleavage of diacyglycerol (DAG), an activator of PKC, from membrane phospholipids was investigated to define the proximal events of IL-4R signaling. IL-4 induced a statistically significant time-and dose-dependent generation of DAG. The IL-4-triggered production of DAG was not derived from phosphatidylinositol 4,5-bisphosphate (PIP2) hydrolysis, since neither cytosolic calcium flux nor liberation of inositol phosphates was detected in response to IL-4. Experiments were performed using [14C-methyl]choline-labeled U937 cells and monocytes to determine whether IL-4R activated phospholipase C (PLC), PLD, or PLA2 to use membrane phosphatidylcholine (PC) to form DAG. IL-4 induced a time- and dose-dependent increase of phosphocholine (pchol) with concomitant degradation of membrane PC (p < 0.05 compared with control). The finding that the peak reduction of PC was equivalent to peak production of pchol suggested that IL-4R signaling involved the activation of a PC-specific PLC. Changes in choline (chol) or lyso-PC and glycerolphosphocholine, the respective products of PC cleavage by PLD or PLA2, were not detected in IL-4-treated cells. In contrast, exogenous PLD induced an increase in chol and concomitant loss of membrane PC. Additional investigation suggested that IL-4R signaling does not involve PLD. In cells labeled with L-lyso-3-PC 1-[1-14C]palmitoyl, PLD but not IL-4, increased the production of phosphatidic acid (PA) and phosphatidyl-ethanol when pretreated with ethanol. Propranolol, an inhibitor of phosphatidate phosphohydrolase, and calyculin A, a phosphatase 1 and 2A inhibitor, blocked DAG production in response to FMLP but not to IL-4. In propranolol pretreated cells, PMA but not IL-4 triggered the production of PA and lowered the amount of DAG. Evidence that PLA2 is not coupled to IL-4R is the detection of arachidonate production in response to FMLP but not to IL-4. Furthermore, IL-4R is not coupled to sphingomyelinase (SMase) since IL-4, unlike exogenous SMase, did not generate ceramide but induced the hydrolysis of PC to pchol that was comparable to exogenous PLC. In summary, IL-4R signaling in monocytes and U937 cells involves PLC and not PLD, PLA2, or SMase, and it uses PC and not PIP2 to form DAG.

Arachidonic Acid↗
PubMed1994

Protein kinase C inhibitors induce apoptosis in human malignant glioma cell lines.

Previous work has demonstrated the importance of the protein kinase C (PKC) system in regulating glioma growth, and has led to clinical trials utilizing PKC inhibitors as adjuncts in the therapy of patients harboring malignant gliomas. This study was performed to explore the possibility that inhibition of PKC in gliomas was triggering an apoptosis signal. Glioma cell lines were treated with PKC inhibitors staurosporine (10 nM), and tamoxifen (10 microM). DNA from cells treated with each of these drugs exhibited a 'ladder' pattern of oligonucleosome-sized fragments characteristic of apoptosis, thus suggesting that in glioma cells, these drugs may be cytocidal in action.

Alkaloids↗