Biomedical subjects
Publications and source records attributed to H Zhou.
According to the typical behaviors from different periods of morphine addicted rat, EEG records were classified into six groups: control, addiction, short term abstinence, long term abstinence, relapse and naloxone. The results indicated that there were typical wave forms in different periods.
Rho family GTPases Rac and Cdc42 are pivotal regulators of apoptosis in multiple cell types. However, little is known about the mechanism by which these GTPases are regulated in response to apoptotic stimuli. Here, we demonstrate that TIAM1, a Rac-specific guanine nucleotide exchange factor, is cleaved by caspases during apoptosis. TIAM1 cleavage occurs in multiple cell lines in response to diverse apoptotic stimuli such as ceramide, Fas, and serum deprivation. Processing occurs at residue 993 of TIAM1 and removes the NH(2)-terminal of TIAM's two pleckstrin homology domains, leaving a stable fragment containing the Dbl homology and COOH-terminal pleckstrin homology domains. This leads to functional inactivation of TIAM1, as determined by failure of the cleavage product to stimulate GTP loading of Rac in vivo. Furthermore, this product is defective in signaling to two independent Rac effectors, c-Jun NH(2)-terminal kinase and serum response factor. Finally, we demonstrate that in cells treated with ceramide, cleavage of TIAM1 coincided with the inactivation of endogenous Rac. These results reveal a novel mechanism for regulating guanine nucleotide exchange factor activity and GTPase-mediated signaling pathways.
OBJECTIVE: To diagnose zygosity of twins by microsatellite polymorphism. METHODS: One hundred and eighty-four samples, including 69 pairs of twins with the same gender and 6 pairs of twins with different gender were recruited. Seventeen sib pairs were also collected for controls. Nine highly polymorphic microsatellite loci were amplified by polymerase chain reaction (PCR) using fluorescence-labeled primers and the products were sized by automated fragment analysis after electrophoresis and laser detection. Zygosity was diagnosed by comparing the concordance of the genotype of the 9 markers. RESULTS: Sixty-three pairs of monozygotic (MZ) and 12 pairs of dizygotic (DZ) twins were assigned their zygosity by comparison of polymorphism of 9 microsatellite loci. Within each of the 63 monozygotic (MZ) pairs there was complete concordance. However, within each of the 12 dizygotic pairs and other 17 sib pairs, discordant loci were found. With five or six markers, the probability that any twin pair was MZ if all markers were concordant was 99% or 99.6%, respectively. With all the nine markers, the probability that any twin pair was MZ if all markers were concordant was 99.95%. CONCLUSION: The technology of gene scan and genotyping provides a rapid and reliable approach to zygosity detection.
OBJECTIVE: To study the effects of dehydroepiandrosterone (DHEA) and/or estradiol (E2) on apoptosis in peripheral blood mononuclear cells (PBMCs) from patients with systemic lupus erythematosus (SLE). METHODS: The percentage of apoptosis of PBMCs from SLE patients and healthy blood donors were examined by means of AO staining 48 h after culture with DHEA and/or E2 at physiologic or pathologic concentrations. RESULTS: The percentage apoptosis of PBMCs from SLE patients is higher than that of healthy blood donors (P < 0.01). E2, whether at physiological or at pathological concentrations, had no effects no apoptosis of PBMCs from both SLE patients and healthy donors (P > 0.05). Both DHEA and DHEA plus E2 at physiologic concentrations, had no effect on apoptosis of PBMCs from healthy donors (P > 0.05), but significantly inhibited that of SLE patients (P < 0.05); at pathologic concentrations, they promoted apoptosis of PBMCs from SLE patients as well as healthy blood donors (P < 0.05). There were no significant differences between the effects of DHEA and that of DHEA plus E2 (P > 0.05). CONCLUSION: DHEA plays an important role in the apoptosis of PBMCs from SLE patients; low serum levels of DHEA may cause accelerated apoptosis.
OBJECTIVE: To establish a method for culturing normal human oral keratinocytes. METHODS: Specimens obtained from healthy humans undergoing oral surgery were dissociated into single cell suspensions by dispase and trypsin. The cells were grown in serum-free medium. Morphological characteristics were studied under light microscope and electron microscope. Cytokeratins were shown by immunohistochemistry. RESULTS: Cells could be maintained in culture up to 4-5 passages or 30-50 days. Electron microscope revealed that there were desmosomes and tonofibrils in the oral keratinocytes. The cells showed positive staining for cytokeratin antibody. CONCLUSION: Human oral keratinocytes have been successfully grown in serial culture.
OBJECTIVE: To investigate the pattern of monocyte chemoattractant prolein-1 (MCP-1) distribution in the renal interstitium and evaluate its pathogenic role in tubulo-interstitial lesions in patients with lupus nephritis, the distribution of MCP-1 in renal tissue was observed. METHODS: Eighteen female patients with biopsy-proven lupus nephritis were enrolled in this study. No intensive immunosuppresive therapy was used in these patients during the 3 months prior to renal biopsy. The distribution of MCP-1, infiltration of CD68+ (macrophage/monocyte), CD4+ and CD8+ cells in the tubulo-interstitium of patients with lupus nephritis was detected using immunohistochemical staining with specific antibodies. Renal specimens from patients with minimal change glomerulonephritis were used as controls. RESULTS: MCP-1 protein was widely distributed in the renal tissue of patients with lupus nephritis, mainly located at the baso-lateral surface of tubular epithelial cells (16/18 biopsies), and on the wall of interstitial blood vessels (9/18 biopsies). In contrast, tubular MCP-1 staining was weak and rare in renal tissue from controls (7.4 +/- 6.2% vs 26.7 +/- 22.8%, P < 0.01). Tubulo-interstitial infiltration of CD68+, CD4+ and CD8+ cells was markedly increased in patients with lupus nephritis as compared to controls. The tubular expression of MCP-1 was strongly associated with the amount of CD68+ cell infiltration in the interstitium (r = 0.5420, P < 0.05) and the extent of interstitial fibrosis. There was no correlation between MCP-1 production in tubules and the degree of urinary protein excretion in patients with lupus nephritis (r = 0.0547, P > 0.05). CONCLUSIONS: The expression of MCP-1 in the renal tubules and vascular wall was markedly increased in patients with lupus nephritis. The overproduction of MCP-1 in renal tissue may contribute to monocyte recruitment in the interstitium and thus result in tubulo-interstitial damage in lupus nephritis.
OBJECTIVE: To study the significance and distribution of renal infiltrating cells, including monocytes (CD68+ cells), proliferative cell nuclear antigen positive cells (PCNA+ cells), CD4+ and CD8+ cells in diffuse crescent glomerulonephritis (DCGN). METHODS: Fifty-six patients with DCGN were studied, including 10 cases of anti-glomerular basement membrane (GBM)--type I DCGN, 26 immune complex--type II DCGN, and 20 cases of pauci-immune--type III DCGN. Glomerular and interstitial infiltrates of CD68+ and PCNA+ cells, and interstitial infiltrates of CD4+ and CD8+ cells were detected by using four-layer PAP methods. RESULTS: There was a significant increase of renal infiltrating CD68+, PCNA+, CD4+ and CD8+ cells in patients with DCGN compared with that in normal controls. In patients with type I DCGN, there was a higher number of renal infiltrating CD68+ and PCNA+ cells than that in patients with type II and III DCGN. A glomerular infiltrates of CD68+ and PCNA+ cells correlated with the interstitial infiltrates of CD4+ cells in type I or III DCGN patients. In lupus DCGN patients, the numbers of renal infiltrating CD68+ and PCNA+ cells were similar to vasculitis or type III DCGN patients. CONCLUSION: These findings demonstrate that the renal infiltrates of CD68+ and PCNA+ cells play an important role in patients with DCGN, that the infiltrates of CD4+ cells correlate with the infiltrates of CD68+ and PCNA+ cells may be an active marker of DCGN, and that cell-mediated immunity may contribute to crescent formation in lupus DCGN patients.
Total RNA was extracted from murine hepatocytes, and the cDNA of interleukin 18(IL-18) was amplified by RT-PCR. The cDNA was introduced into the expression vector pJW2 and sequenced. Under heat induction, the recombinant murine IL-18(rmIL-18) was expressed in inclusion bodies in E. coli with the yield accounting for 18% of total bacteria proteins. The inclusion bodies were dissolved with 5 mol/L urea, and rmIL-18 was purified using Sephadex G-100 column chromatography. In the presence of 0.5 mg/L Con A, the purified rmIL-18 showed dose-dependent IFN-gamma-inducing activity in murine splenocytes. The purified rmIL-18 exhibited significant antitumor effects in Kunming mice challenged intraperitoneally (i.p.) with H22 hepatocarcinoma when administered 10 micrograms rmIL-18 i.p. on days 1, 4 after challenge, and the mice survived resisted the rechallenged with H22 cells.
OBJECTIVE: To investigate the nosocomial infection among inpatients. METHODS: A retrospective study on 12 418 inpatients was undertaken from January to December in Beijing Hospital in 2000. RESULTS: Three hundred and seventy-eight cases due to nosocomial infection were identified with a rate of 3.04%. There existed significant differences with rates of different sex and ages. The infection rate in males was higher than in females. The older the age, the higher the rates of infection was noticed. Nosocomial infections occurred mainly in the lower respiratory tract (35.99%), upper respiratory tract (22.46%), urinary tract (17.63%) and gastrointestinal tract (10.39%). The main pathogenic organisms of the nosocomial infection were Candida albicans (15.78%), Pandomonos (13.15%) and Enterococcus (11.84%) with gram negative bacilli (46.03%), gram positive coccus (23.68%) and fungus (15.78%). The overall death rate of nosocomial infection was 14.29%. CONCLUSIONS: Nosocomial infections were closely correlated with sex, age, department of wards and invasive operation etc. Prevention and proper treatment of nosocomial infection should be strengthened.
OBJECTIVE: To investigate the existential status of BPI as a natural defensive factor in human polymorphonuclear leukocytes (PMNL). METHODS: The abilities of porcine BPI to combine endotoxin (lipopolysaccharide, LPS) and inhibit the release of TNFalpha from hepatic Kupffer's cells were examined. And the expression of BPI in PMNL after stimulation by LPS was determined by flow cytometry. RESULTS: The ability of porcine BPI to combine LPS was increased along with the increment of BPI concentration. The effects of the BPI on the inhibition of the release of TNFalpha from hepatic Kupffer's cells were dose-dependant. The expression of BPI in PMNL was enhanced obviously within 30 mins of LPS stimulation. But there was no immediate release of BPI into blood. CONCLUSION: BPI possessed potential power of neutralizing LPS. It might be beneficial to supplement exogenous BPI in case of Gram negative bacterial infection.
OBJECTIVE: To investigate the relationship between lymphocyte apoptosis in spleen and mesenteric lymph nodes (MLNs) and gut -- origin lipopolysaccharide (LPS) translocation after severe scalding in rats. METHODS: Wistar rats inflicted 30% TBSA III degree scalding were employed as the model. Serum LPS levels in portal vein and vena cava were determined by limulus amebocyte lysate (LAL) test. Apoptotic lymphocytes in paraffin -- embedded spleen and MLNs sections were detected with TdT -- mediated and dUTP nick end labeling (TUNEL) and peroxidase (POD) staining. The images were taken by cooldccd camera system, and the count and optical density (OD) value of apoptotic lymphocytes were analyzed with software Spot and Imagine proplus 4.10a (IPP4.10a). RESULTS: Serum LPS levels in portal vein and vena cava increased sharply in rats postburn (P < 0.01) and reached a peak value at 6 postburn hour (PBH). LPS level in portal vein was higher than that in vena cava (P < 0.01) in the period of 3 to 48 PBHs. The results of TUNEL -- POD staining and the count of apoptotic lymphocytes showed that the apoptotic cells were few in normal MLNs, but increased obviously postburn (P < 0.01), especially at 3 PBH. On the contrary, apoptotic lymphocytes were concentrated in spleen cortex before injury and decreased obviously postburn (P < 0.01), though a slight recovery was found after 24 PBH. Optical density of apoptotic lymphocytes was significantly reduced in spleen at 24 PBH, But the OD value of apoptotic lymphocytes in MLNs increased significantly within 48 PBHs when compared with that before injury (P < 0.01). CONCLUSION: Gut -- origin endotoxemia in rat could occur in early postburn period. The LPS translocation might induce lymphocyte apoptosis in MLNs. The decreased apoptotic lymphocytes in spleen implied abnormal immune function in spleen.
OBJECTIVE: To investigate the changes of telomerase activity and its related genes expression in leukemia cells and their roles in leukemogenesis. METHODS: The telomerase activity in bone marrow cells of 47 leukemia patients were detected by a semi-quantitative telomeric repeat amplification protocol (TRAP)-silver staining, and the expression of telomerase related genes hEST2, TP1 and hTR by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR). RESULTS: The telomerase activity and expression of telomerase related genes were significantly higher in 42 leukemia patients in progress stage than that in complete remission/chronic stage and in normal/anemia cases (P < 0.01). The telomerase activity and expression of TP1, hTR gene in 14 cases of acute leukemia complete remission (AL-CR)/chronic myelogenous (CML)-chronic stage were higher than that in normal/anemia cases (P < 0.05). Low levels of telomerase activity and telomerase related genes expression could be detected in part of normal bone marrow cells. The levels of telomerase activity and telomerase related genes expression in 3 cases of anemia increased after short-term culture. CONCLUSIONS: High level of telomerase activity and its related genes expression were specific markers of malignant hematopoietic cells and their changes might be useful for observation of treatment effectiveness in leukemia. Low level of telomerase activity was associated with hematopoietic stem cells with the ability of proliferation. hEST2 gene might be a up-regulation gene of telomerase; hTR might be related to feedback regulation of telomerase.
Capacitative calcium entry (CCE), the mechanism that replenishes intracellular calcium stores after depletion, is essential to intracellular calcium signaling. CCE is mediated by the channels in the plasma membrane generally referred to as "store operated channels (SOCs)". However, the molecular identity of the SOCs has never been determined, and the mechanism of the activation of SOCs remains to be elucidated. Recent studies have demonstrated that 2-aminoethoxydiphenyl borate (2-APB), which has been found to be an antagonist of inositol 1,4,5-trisphosphate receptors (IP3Rs), inhibits CCE, suggesting that IP3Rs channel activity is essential to the generation of CCE. However, CCE has also been reported to occur normally in IP3R-deficient cells. In order to resolve this discrepancy, we investigated the effect of 2-APB on CCE in IP3Rs-deficient cells. In response to store depletion with thapsigargin or N,N,N',N'-tetrakis (2-pyridylmethyl) ethylene diamine (TPEN), CCE was generated in IP3Rs-deficient cells the same as in wild-type cells, however, 2-APB abolished CCE in IP3Rs-deficient cells, despite the fact that this cell line does not possess functional IP3Rs. We also examined the effect of 2-APB on several types of TRP Ca2+ channels, which exhibit properties similar to those of SOCs. 2-APB had a different inhibitory effect on spontaneous and thapsigargin-induced Ba2+ influx in cells that transiently expressed individual TRP subtypes. These results suggest that the channel activity of IP3Rs is not essential to the generation of CCE in this cell line and that 2-APB inhibits CCE independently of the function of IP3Rs.
Influenza surveillance networks in Guangdong were established to investigate the epidemiological characteristics of influenza and influenza epidemics. Influenza activity peaked annually from March to July in Guangdong in 1991-2000; influenza H3N2 predominated in the epidemic (7 years of 10); the outbreak of influenza in 1996 was the remarkable result of antigenic drift of H3N2 strain. Ten isolates of H9N2 strains were discovered from human subjects in 1998 and 1999: chicken strains isolated after the Hong Kong fowl influenza outbreak. It was found that there was just one influenza activity season per annum in Guangdong and that the influenza H3N2 subtype still predominates in Guangdong. Further research into the pathogenicity of influenza H9N2 in humans warranted.
OBJECTIVE: The aim of this study is to evaluate advantages and disadvantages of two types of appliances for maxillary molar distalization. METHODS: Totally, 28 patients with class II malocclusion resulting from molars shifting mesially were treated using two different molar distalization methods, including using removable and fixed appliances. An intra-oral removable acrylic appliance with headgear for extra-oral traction resulted in tipping the maxillary first molars distally. The modified rapid helix expansion appliance (MRHEA), which consisted of bands, anchorage teeth, Nance palatine bases, helix bars and connecting rods, made the maxillary first molars move parallel distally. RESULTS: The desired efforts were gained in 7 or 9 months by using removable appliances, but only 2 or 2.5 months if using MRHEA. The treatment results of using removable appliances were dependent on patients' cooperation, however, the method of using fixed appliance overcame some shortcomings of other molar distalization techniques, and this appliance would not lead to the distal inclination of the crown of the shifted teeth. CONCLUSION: These two methods could convert the class II molar relationship to class I. The MRHEA can save much chair-side time, and shorten the period of treatment, move molars distally parallel.
OBJECTIVE: To study the main death cause of nasopharyngeal carcinoma (NPC) treated with radiotherapy for 5 years. METHOD: An analysis had been made to evaluated the 5-year death in 165 patients with NPC treated with radiotherapy. RESULT: The death correlates strongly with the clinical stage, type and radiation dose (P < 0.05). CONCLUSION: The distant metastasis and local recurrence are the main death cause of NPC.
Organic and inorganic anions in snow and ice from Glacier 1 at Urumqi river head, Tianshan Mountain, Xinjiang, Northwest China, were determined using DIONEX-300 ion chromatograph with a lot of columns. AS4A-SC was selected as the separation column, AG4A-SC as the guard column, TAC-2 as the anion enrichment column, ATC-1 as the anion trap column and ASRS-II as the suppresser. It was conducted under gradient elution with sodium tetraborate (Na2B4O7) as eluent and 25 mmol/L H2SO4 as regeneration solution for chemical suppression. By preconcentration, 2 mL melted water of snow or ice can be analyzed for separation and quantitation of more than 10 anions, which were fluoride, acetate, formate, pyruvate, monochloroacetate, chloride, nitrite, bromide, nitrate, phosphate, sulfate and oxalate. The relative standard deviations for most of the anions were below 5%.
PURPOSE: To evaluate the biocompatibility and 'healing' of Bioglass Ceramic(BGC) in the cornea. METHODS: BGC dicks (8 mm in diameter, 0.5 mm thick, 20-70 microns pore diameter, 37-62% porosity, 7.8 mm radius of curvature) were implanted in 11 New Zealand albino rabbits after a free-hand intralamellar dissection. The eyes were examined by slit-lamp biomicroscope up to seven months postoperatively. The corneas were removed at seven month (one eye at eight month), then were examined by light microscope. RESULTS: Five of 11 dicks of BGC were extruded. All implant of BGC with 51-62% porosity were broken and then extruded. A large part of implants led to markedly edematous with severe degrees of corneal neovascularization within one month postoperatively. The corneal lamella before implants became not clear in all eyes after two months. Lipid deposits occurred in four eyes. It is difficulty to observe the 'healing' process of BGC in the cornea because the BGC is too hard to be cut in spite of being soft by 4% hydrochloric acid for four to ten days before cutting. CONCLUSION: Our findings suggest that BGC with above parameters is not suitable as peripheral keratoprosthetic materials because of its rough, hard, thick and breakable.