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Biomedical subjects

X Chen

Publications and source records attributed to X Chen.

At least 973 records · Page 54Linked to original sources
PubMed1998

[The clinical and pathological characteristics of exaggerated placental site].

OBJECTIVES: To study the pathological and clinical features of exaggerated placental site (EPS) and to propose its diagnostic criteria and differential diagnosis. METHODS: The pathological features, immunohistochemical marks, clinical characteristics and prognosis of 13 cases with EPS were studied and analyzed. RESULTS: The histological feature of EPS was that trophoblasts mainly intermediate trophoblast (IT), infitrated into decidua and myometrium layers, while original histological structure was not destroyed, and placental site features remained partially. The immunohistochemical marks of EPS, HPL and EMA, were positive or strongly positive. The primary clinical presentation of EPS was postpartum hemorrhage and the prognosis was good in 5 years. CONCLUSIONS: EPS is a kind of gestational trophoblastic disease primarily involving IT. It may be a preneoplastic lesion of placental site trophoblastic tumor (PSTT). Its differential diagnosis depend on combining histological, immunohistochemical findings, and clinical features. Attentions should be paid to EPS in cases with postpartum hemorrhage.

Adult↗
PubMed1998

[Effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on apoptosis-related genes in glomerular mesangial cells].

OBJECTIVE: To investigate the effects of Arg-Gly-Asp-Ser (RGDS) tetrapeptide on the expressions of apoptosis-related genes interleukin-1 beta-converting enzyme (ICE) and bcl-2 in human glomerular mesangial cells, so as to provide experimental evidence for regulating proliferation and apoptosis of mesangial cells with RGD-containing polypeptide. METHODS: Propidium iodide staining was used to observe the condensation and fragmentation of apoptotic nuclei. The internucleosomal DNA fragmentation was detected by DNA electrophoresis on agarose gel. The expressions of ICE and Bcl-2 were determined by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: After ten hours of incubation, the glomerular mesangial cells treated with RGDS peptide displayed features consistent with apoptosis, such as nuclear condensation and fragmentation, and a regularly spaced "ladder" shape of genomic DNA electrophoresed. And RT-PCR showed that expressions of both ICE and Bcl-2 mRNAs were apparently increased in RGDS treated group, compared with that of the control group. CONCLUSION: These results demonstrated for the first time that RGDS peptide was able to induce apoptosis in human glomerular mesangial cells, during the process ICE and bcl-2 genes may have an important regulating role.

Apoptosis↗
PubMed1998

[Auditory P300 in assessing cognitive dysfunctions of Alzheimer's disease and schizophrenia].

OBJECTIVE: To investigate the value of auditory P300 in assessing cognitive dysfunctions of aged patients with Alzheimer's disease(AD) or schizophrenia. METHODS: An'oddball' paradigm was used to elicit the auditory P300 from 39 patients diagnosed as having Alzheimer's disease according to DSM-III-R, 34 aged schizophrenics and 40 normally age-matched subjects, by using a Dantec Concerto SEEG-16 instrument. RESULTS: The variability of P300 waveform increased in AD patients, who presented reduced N1 latency elicited by frequent stimuli. The P3 amplitude of the AD patients was lowered by 14% compared with that of schizophrenics, and by 60% than compared with that of normal controls. Compared with the normal controls, schizophrenics presented reduced N1, P2, N2 and P3 latencies, and their P3 amplitude was decreased by 54%. CONCLUSION: The auditory P300 is of value in assessing the cognitive dysfunctions of AD patients and aged schizophrenics.

Aged↗
PubMed1998

[Identification of interleukin-1 beta converting enzyme gene expression in human kidney].

OBJECTIVE: To confirm that Interleukin-1 beta-converting enzyme(ICE) is a first identified apoptosis related gene in mammals. METHODS: The expressions of ICE mRNA in human kidney tissue, different segment of nephron and glomerular resident cells were measured by using the method of microdissection, reverse transcription-polymerase chain reaction(RT-PCR) and Northern hybridization. RESULTS: Compared with peripheral blood mononuclear lymphocyte weak expressions of ICE mRNA were noted not only in glomeruli and tubule but also in glomerular mesangial cells, glomerular endothelial cells and tubular epithelial cells of the human kidney. CONCLUSION: There is a widely distributed expression of ICE mRNA in the human kidney, which may provide a theoretical basis for the study of ICE gene in apoptosis of kidney.

Caspase 1↗
PubMed1998

[Brain evoked potentials in patients with Alzheimer's disease and schizophrenia: a comparative study].

OBJECTIVE: To investigate the differences of visual evoked potentials(VEP) and auditory evoked potentials(AEP) between patients with Alzheimer's disease and schizophrenics. METHODS: Both VEP and AEP were elicited from 39 patients with Alzheimer's disease, 34 aged schizophrenics and 40 normally age-matched subjects. RESULTS: The variability of waveforms of both VEP and AEP became increased within the AD group. The AD patients presented significantly delayed latencies (N2 and P3 of VEP; P1, N1, P2, N2 and P3 of AEP) as compared to the normal controls. The P2 amplitude of VEP of AD patients was 32% lower than that of schizophrenics and 57% lower than that of the controls. The P2 amplitude of AEP of AD patients was 36% lower than that of schizophrenics and 70% lower than that of the controls. Compared with the normal controls, the schizophrenics showed reduced VEP-P2 latency, prolonged N2 and P3 latencies of both VEP and AEP. The P2 amplitudes of VEP and AEP of schizophrenics were decreased by 16% and 20% respectively as compared to the normal controls. CONCLUSION: The variations of VEP and AEP are a referential tool for diagnosing Alzheimer's disease and schizophrenia.

Aged↗
PubMed1998

[Cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of ginkgo biloba leaves].

OBJECTIVE: To examine the anti-free radical related cardiovascular protective effects and NO-mediated cerebrovasorelaxant effects of extract of the leaves of Ginkgo biloba(EGb) in isolated preparations. METHODS: Experiments on the anti-free radical related cardiovascular protective effects were performed in rabbit Langendorff heart and isolated aortic rings damaged by diphenyl-picryl hydyazyl(DPPH). Protective effects of EGb were determined by comparing the results of EGb pretreated group with the DPPH-injured controls. Cerebrovasorelaxant effects of EGb were examined in ring preparations of isolated porcine basilar artery in vitro using tissue bath techniques. RESULTS: EGb protected the isolated rabbit heart from the DPPH-injury to the cardiac contractility and the aortic endothelium from DPPH-attenuated ACh-induced relaxation. EGb concentrationde dependently relaxed the basilar artery and this effect was more significant in endothelium intact rings than those endothelium denuded rings. EGb enhanced the TNS-induced relaxation in basilar artery and this effect was abolished by pretreatment of N-nitro-L-arginine or tetrodotoxin. CONCLUSIONS: EGb exerts cardiovascular protection against DPPH-impaired cardiac contraction in rabbit isolated heart and endothelium-dependent relaxation in the aortic ring of rabbit in vitro. EGb relaxes porcine basilar artery and enhances the TNS-induced relaxation via a NO pathway.

Animals↗
PubMed1998

[The deletion of AT2 receptor gene antagonizes angiotensin II-induced apoptosis in fibroblasts].

OBJECTIVE: To study the expression of angiotensin II (Ang II) type 2 receptor (AT2) and its effect on the Ang II-induced apoptosis in fibroblasts. METHODS: Skin fibroblasts were cultured from the embryos of the AT2 receptor gene deleted (AT2-/-) and wild-type (AT+/+) mice at 16 days of gestation. After Ang II being stimulated, the expressions of AT1 and AT2 receptor genes were examined by RT-PCR and the apoptotic changes were identified by genomic DNA electrophoresis, TUNEL staining and flow cytometry analysis of DNA contents. And they were compared in these two types of cultured fibroblasts. RESULTS: Treated with Ang II for 48 h at the concentrations of 10(-8), 10(-7), 10(-6) and 10(-5) mol/L respectively, the expressions of AT1 and AT2 receptor genes were enhanced in a dose-dependent manner. Induced by Ang II for 72 h at the concentrations of 10(-6) and 10(-5) mol/L, genomic DNA fragmentation, one of convinced markers of cell apoptosis was found in the AT2+/+ fibroblasts, but not in the AT2-/- fibroblasts. The percentages of Ang-induced apoptosis of the AT2+/+ fibroblasts were (12.3 +/- 2.7)% (10(-6) mol/L) and (21.7 +/- 6.7)% (10(-5) mol/L) respectively. CONCLUSION: The Ang II-induced apoptosis of fibroblasts was devoid after deletion of AT2 receptor gene.

Angiotensin II↗
PubMed1998

[The protective effects of baicalin on pertussis bacilli-induced brain edema in rats].

OBJECTIVE: To evaluate the inhibitory effect of baicalin on iron-dependent lipid peroxidation (IDLPO) and the protective effect on pertussis bacilli-induced brain edema in rats. METHODS: In vitro, the inhibitory effect of baicalin and deferoxamine (DFX) was studied at different concentrations on IDLPO in brain homogenates of Sprague-Dawley rats. In vivo, the protective effect was studied of baicalin and DFX on brain edema induced by injecting purtussis bacilli into the left internal carotid artery in rats. Forty Sprague-Dawley rats were randomly divided into four groups. Group 1 (NS, n = 10), as control; Group 2 (PB, n = 10), pertussis bacilli control; Group 3 (DFX, n = 10), PB + deferoxamine; and Group 4 (BAI, n = 10), PB + baicalin. RESULTS: The baicalin was possessed of an inhibitory effect on IDLPO in rat brain homogenate, moreover, the inhibitory potency of baicalin was approximately 20 times higher than DFX treated alone. In vivo, the increase in the content of water(CW) and Evans blue (EB) was attenuated in groups DFX and BAI (CW: 79.8 +/- 0.7)% and (79.5 +/- 0.6)%; (EB: 11 +/- 7 micrograms/g and 12 +/- 5 micrograms/g) as compared with the group PB (CW: 80.4 +/- 0.9%, EB: 24 +/- 10 micrograms/g). The content of iron was significantly lower than in the left hemispheres (injected side) in the group DFX and the group BAI (79 +/- 9 micrograms/g and 77 +/- 10 micrograms/g) than in the left hemispheres in the group PB(132 +/- 28 micrograms.d-1.g), P < 0.05. The activation of CuZn-SOD (L155 +/- 36 U/mg pr, R177 +/- 75 U/mg pr) was decreased in the group BP compared with the group NS(L 201 +/- 49 U/mg pr, R 249 +/- 49 U/mg pr), P < 0.05. The activation of CuZn-SOD was significantly higher in the left brain tissues in the groups DFX and BAI (222 +/- 49 U/mg pr and 230 +/- 45 U/mg pr, respectively) than in the left brain tissues of the group of PB (P < 0.05). CONCLUSION: The baicalin and DFX have a protective effects on the pertussis bacilli-induced brain edema in rats, and the protective effects are related to the inhibitory effect on IDLPO, chelating Fe2+, and activated CuZn-SOD.

Animals↗
PubMed1998

[Angiotensin II type 2 receptor inhibits type 1 receptor-induced cell proliferation and fibronectin release in mouse fibroblasts].

OBJECTIVE: To investigate the effects of angiotensin II type 2 receptor (AT2) on the cell proliferation and fibronectin release induced by angiotensin II type 1 receptor (AT1). METHOD: Fibroblats were cultured from embryonic skin of AT2 receptor gene knocked-out mice (AT2-/-) and wild-type mice (AT2+/+) after 16 days of gestation, respectively. Cell proliferation and fibronectin release were examined in the fibroblasts treated with 10(-8) mol/L angiotensin II. RESULTS: Cell proliferation rate was increased more markedly in the AT2-/- fibroblasts than in the AT2+/+ fibroblasts after treament with angiotensin II (0.462 +/- 0.026 VS 0.389 +/- 0.021, P < 0.01). Also, fibronectin release and its gene expression were significantly enhanced in the AT2-/- fibroblasts as compared with the AT2+/+ fibroblasts when exposed to angiotensin II (34.1 +/- 4.1)% vs (16.2 +/- 2.3)%, P < 0.01). CONCLUSION: The AT2 receptor can inhibit the cell proliferation and fibronectin release induced by the AT1 receptor.

Angiotensin II↗
PubMed1998

Detection of filarial larvae in mosquitoes with oligonucleotide probe.

OBJECTIVE: To investigate a new way to detect filarial larvae in mosquitoes and apply it to the surveillance of filariasis. METHODS: An oligonucleotide probe that was species-specific to W. malayi was synthesized and marked with 32P using molecular biological technique. Then the probe was tested with dot hybridization in detection of W. malayi filarial larvae from mosquitoes. RESULTS: The minimal detectable limit was found to be 2 ng DNA of filarial larvae or microfilaria (Mf.), with no cross reaction with other animal filariae. A single larva can be detected when infected mosquitoes were tested one by one. One infected mosquito can be detected from a group of 20 mosquitoes tested together. CONCLUSIONS: Our probe is sensitive and specific. It is practical to apply our probe to mosquito surveillance in Brug's filariasis endemic areas.

Animals↗
PubMed1998

[Alterations of intracellular free calcium concentration of cerebral neuronal cells in infectious brain injury in rats].

Intracellular free calcium concentration, [Ca2+]i, of cerebral synaptosomes loaded by Fura-2/AM was measured by fluorescent method to clarify alterations of [Ca2+]i in infectious brain injury (IBI) in rats. The results showed that [Ca2+]i, water content (WC), and Evans blue content (EB) in groups injected by Bordetella pertussis suspension (BP) were increased compared to those in groups injected by normal saline (NS) at 0.5 h, 4 h, and 24 h, respectively. Increased [Ca2+]i in BP groups showed time-dependent relationship and the highest level in the 24 h group. There was positive correlation (0.5 h, 4 h) and no correlation (24 h) between [Ca2+]i and WC or EB. It is suggested that [Ca2+]i accumulation of cerebral neuronal cells plays an important role in the pathogenetic mechanism of the acute and delayed IBI induced by BP.

Animals↗
PubMed1998

Growth regulation of ovarian cancer cell line HO-8910 by transforming growth factor beta 1 in vitro.

OBJECTIVE: To further understand the role of growth regulation of human ovarian cancer cells by transforming growth factor (TGF) beta 1. METHODS: The cell proliferation, cAMP synthesis, gene expression, and induction of programmed cell death (PCD) in human epithelial ovarian cancer cell line HO-8910 cells exposed to TGF beta 1 in vitro were studied. RESULTS: TGF beta 1 inhibited cell growth and DNA synthesis, and induced G0/G1 arrest in cell cycle. It could also trigger PCD in cells. This induction of PCD may occur within G0/G1 phase. Meanwhile, the assay also showed that TGF beta 1 could inhibit the mRNA expression of c-myc, EGFR and TGF beta 1 genes in cells. CONCLUSIONS: TGF beta 1 can not only act as an autocrine to inhibit cell proliferation, but also trigger PCD in HO-8910 cells. These functions may be fulfilled through some specific signal transduction pathways.

Apoptosis↗
PubMed1998

[The growth inhibition of anti-EGF receptor monoclonal antibody to human lung adenocarcinoma cells].

OBJECTIVE: Epidermal growth factor (EGF) and its receptor play a critical role in the growth and regulation of many type of malignant cell. The high level of expression of the EGFR on normal cell lung cancer(NSCLC) and the important role of EGFR in signal transduction make it potentially an excellent target for antibody directed therapy. The purpose of this study was to evaluate the anti-tumor effects of anti-EGFR monoclonal antibody on lung carcinoma cells. METHOD: Preparation of hybrid cell producing anti-EGFR monoclonal antibody using EGF receptors partially purified from A431 cells as immunogen. The effect of anti-EGFR monoclonal antibody to human lung cells was investigated in vitro. RESULT: The anti-EGFR monoclonal antibody was shown to inhibit the proliferation of human lung adenocarcinoma cells in vitro, but no growth-inhibitory effect was observed in the human small cell lung cancer cells. The concentration, 15 ug/ml, of anti-EGFR antibody could inhibit growth rate by 94% and 88% for human lung adenocarcinoma cell lines SPC A-1 and A549, respectively. CONCLUSION: Our initial results indicate that the anti-EGF receptor monoclonal antibody may be potentially useful for the biotherapy of lung adenocarcinoma.

Adenocarcinoma↗
PubMed1998

[Incidence, risk and prognostic factors of pneumonia acquired at intensive care units].

OBJECTIVE: To estimate the incidence of pneumonia acquired in the intensive care unit, and to define risk factors for developing such an event. METHOD: A total of 158 patients were retrospectively analyzed and 108 of them acquied pneumonia at ICU of Zhongshan Hospital (surgical ICU and respiratory ICU) and Huashan Hospital (general ICU) from January 1996 to November 1997. Statistical analysis was made using SPSS, odds ratios and stepwise logistic regression analysis were used to determine the interrelationships between multiple variables. Statistical significance was predetermined to include p values of < 0.05. RESULT: The following five factors were significantly (P < 0.05) associated with HAP: cancer [OR = 6.73, 95% CI = 1.58 to 28.59], treatment with H2-blockers (OR = 5.5742, CI = 1.94 to 15.99), decreased consciousness (OR = 3.30, CI = 1.52 to 7.18), use of urethral catheters (OR = 1.07, CI = 1.01 to 1.13), and mechanical ventilation (OR = 1.05, CI = 1.00 to 1.01). The risk facors for HAP were different among different ICU. The risk of developing pneumonia increased when depressed level of consciousness and mechanical ventilation were present at general ICU. Factors significantly predisposing to HAP were underlying COPD, using H2-blockers and mechanical ventilation at respiratory ICU, and previously lower respiratory tract infection was the risk factor for HAP in surgical ICU. The following factors were associated with a significantly higher fatality rate in HAP patients: depressed level of consciousness (P = 0.02), previously lower respiratory tract infection (P = 0.001), and long-time mechanical ventilation (P = 0.03). CONCLUSION: The risk factors for HAP were different among different ICU, which may be related to the difference of patients with an ultimately or a rapidly fatal underlying illness admitted to these units.

Cross Infection↗
PubMed1998

[Clinical and experimental research of Epimedium brevicornum in relieving neuroendocrino-immunological effect inhibited by exogenous glucocorticoid].

OBJECTIVE: To study protective effect of Epimedium brevicornum (EB) on hypothalamus-pituitary-adrenal-thymus (HPAT) axis inhibited by exogenous glucocorticoid. METHODS: In clinical research, variation of cortisol, adrenocorticotrophin (ACTH), lymphocyte proliferative reaction were observed before and after medication in 65 patients took prednisone, and were randomly divided into Fufang prednisone group (mixture of prednisone and EB) and prednisone group. An experimental model of HPAT axis inhibited by corticosterone (CORT) was established to observe the effect of EB on relevant indices of HPAT axis. RESULTS: The level of ACTH and CORT in plasma decreased and lymphocyte proliferative reaction reduced in patients (P < 0.05). In experimental study, monoaminic transmitters activated in hypothalamus; weight of pituitary, adrenal and thymus decreased; number of CRH positive neurons in hypothalamic paraventricular nucleus, CRH positive neurofibrilin median eminence and anterior pituitary ACTH positive secretory cells decreased; adrenal fasciculate zone and thymus cortex atrophies; NK cell cytotoxicity and the level of IL-2 and gamma-IFN which were produced by lymphocytes reduced in CORT-rats (P < 0.05). There were significant difference between Fufang prednisone group (clinical research) or EB group (experimental research) and CORT control groups, P < 0.05. CONCLUSION: EB could relieve neuroendocrino-immunological effect inhibited by exogenous glucocorticoid.

Adult↗
PubMed1998

[Influence of shenxu gutong capsule on femoral inorganic elements content and ash weight in rats].

OBJECTIVE: To explore the mechanism of Shenxu Gutong Capsule (SXGTC) in treating postmenopausal osteoporosis. METHODS: Using ovariectomized rats as the model of postmenopausal osteoporosis, the effect of SXGTC on inorganic element content of femur and femoral ash weight of the model rats were surveyed. Animals were divided into model group, SXGTC high dose group, SXGTC low dose group, positive control group (treated with Gushukang) and normal control group. The medication began at one week after operation and lasting for 120 days. RESULTS: The contents of inorganic elements, including Ca, P, Mg, Zn, Cu and Mn in the three medicated groups were higher than those of the model group (P < 0.01). The effect of SXGTC was dose dependent. The difference between the SXGTC groups and the positive control group was insignificant. The femoral ash weight of the SXGTC high dose group and the positive control group was significantly higher than that of the model group (P < 0.01). CONCLUSIONS: SXGTC could antagonize the rat's bony change caused by ovariectomy to increase the inorganic contents in bone, which may, in grneral, lead to a bone-strengthening effect.

Animals↗