Biomedical subjects

J Zhou

Publications and source records attributed to J Zhou.

At least 217 records · Page 12Linked to original sources

PubMed2001

Inhibitory effects of berberine on IK1, IK, and HERG channels of cardiac myocytes.

AIM: To study the effects of berberine on inward rectifier potassium current (IK1) and outward delayed rectifier potassium current (IK) of guinea pig ventricular myocytes, and on human ether-a-go-go related gene (HERG) channel expressed in Xenopus oocytes. METHODS: Whole cell patch-clamp and geneclamp techniques were used to record ionic currents. RESULTS: Berberine prolonged action potential duration (APD) and inhibited IK1 and IK in a concentration-dependent manner. Berberine 100 micromol/L increased APD90 from (450 +\- 48) ms to (888 +\- 90) ms (n = 6, P < 0.01), and inhibited IK1 by 65 % +\- 7 % (n = 6, P < 0.01). Berberine 50 micromol/L inhibited IK by 57 % +\- 6 %, IKtail by 53 % +\- 6 % (n = 6, P < 0.01). Berberine produced a voltage-dependent block on IK that increased with stronger depolarization, and once all channels were activated, there was no further block at positive potentials. Berberine blocked the HERG channels potently with an IC50 value of approximately 75 micromol/L. This block was voltage-dependent, suggesting that it probably bind to either open or inactivated HERG channels. CONCLUSION: Berberine prolonged APD and possessed blocking effect on IK1, IK, and HERG channel expressed in Xenopus oocytes. The antiarrhythmic mechanism of berberine is related to its inhibitory effects on IK1, IK, and HERG channel.

Action Potentials↗

PubMed2001

[Changes of Ca2+ channel behaviors in bronchial smooth muscle cells of asthma guinea-pig model].

OBJECTIVE: To investigate the relationship between the change of calcium channel behavior in bronchial smooth muscle cells (BSMCs) and the airway hyperresponsiveness in guinea-pigs with asthma. METHODS: The changes of calcium channel dynamics in BSMCs of 4 asthma guinea-pig models (22 cells) and 5 normal guinea-pigs (25 cells), and the inner peak calcium current in BSMCs of 5 asthma guinea-pig models (25 cells) and 6 normal guinea-pigs (24 cells) were determined by patch-clamp techniques. RESULTS: (1) The open time of calcium channel in BSMCs of asthma group was (1.70 +/- 0.40) ms, 2.32 times as much as that of control group (0.70 +/- 0.10) ms; the close time of calcium channel in BSMCs of asthma group (5.7 +/- 0.6) ms, was significantly shorter that that of control group (7.9 +/- 0.4) ms; The open probability in asthma group (0.40 +/- 0.10)% was significantly increased than that of control group (0.20 +/- 0.20)%, (P < 0.01); (2) The inner peak calcium current in BSMCs of asthma group was (-54 +/- 23) PA, 1.17 times as muth as that of control group (-25 +/- 8) PA, (P < 0.01). CONCLUSION: The enhanced activity of calcium channel an BSMCs of asthma guinea-pig mudels may be one of the important factors responsible for the airway hyperresponsiveness.

Animals↗

PubMed2001

[Diversity of Sinorhizobium fredii strains].

Rhizobial strains were isolated from soils growing with soybean cultivar Heilong 33 and Willimas. Fifty Sinorhizobium fredii strains were chosen, and their biological characteristics including growth velocity, acid-alkali endurance, resistance of intrinsic antibiotics, utilization of carbon and nitrogen sources, absorption of congo red, ability of melanin production, and plasmid profiles were comparatively researched. The dendrogram was described using the method of cluster analysis, and the biodiversity of Sinorhizobium fredii from different soils was proved.

Carbon↗

PubMed2001

[Effect of pH on nodulation of soybean rhizobia from Weifang and Huayuankou soils].

The effect of pH on the nodulation of Sinorhizobium fredii and Bradyrhizobium japonicum was examined by analyzing the indigent soybean rhizobia, predominant indigent rhizobia, and specific rhizobia, respectively. The results showed that very acid and very alkaline environment could retard the nodulation and inhibit the growth of the rhizobia. Sinorhizohium fredii could endure environment more strongly than Bradyrhizobium japonicum, and had a high competitive nodulation capacity. Bradyhizobium japonicum could endure acid environment more strongly than Sinorhizobium fredii. In very acid and very alkaline environment, the nodulation capacity of S. fredii and B. japonicum was mainly determined by their physiological characteristics.

Bradyrhizobium↗

PubMed2001

[Runoff loss ways of nutrients in non-irrigated farmland in Hefei outskirts].

Taking non-irrigated flatlands in Hefei outskirts as experiment observation areas, yellow brown soil as selected soil type, and < 3 degrees as ground slope, the time of runoff development, runoff quantities, and silt carrying capacity under different rainfall intensity were observed on the non-irrigated farmlands with different kinds of crops such as grain, oil, cotton and vegetables, and with different coverage for continuous 3 years. Based on the observation, water and soil samples were collected and analyzed. The results showed that the loss way of the surface soil and nutrients in non-irrigated flatlands was obviously different from that on the sloping fields and on the upland. Over 98% of available N, P, and K nutrient loss were run off by chemical erosion. Physical erosion was the main way of the surface soil and organic matter loss, and 96.14% of total organic loss was caused by physical erosion.

Ecology↗

PubMed2001

[Comparison between one-site and two-site incision in phacotrabeculectomy].

OBJECTIVE: To compare the effect of one-site and two-site incision in phacotrabeculectomy in terms of intraocular pressure control. METHODS: Forty-five cases (47 eyes) of phacotrabeculectomy were retrospectively reviewed. The nuclei of all the cases were not harder than Grade III. One-site approach was performed on 29 eyes, and two-site approach, on 18 eyes. The effects of intraocular pressure control were compared between the two groups. RESULTS: Follow-up was 13-30 months (mean 18.9 months). The postoperative intraocular pressure in the one-site group was (16.81 +/- 4.56) mm Hg (1 mm Hg = 0.133 kPa), (15.32 +/- 6.67) mm Hg lower than that before surgery. And the postoperative intraocular pressure in the two-site group was (17.63 +/- 4.60) mm Hg, (16.42 +/- 6.98) mm Hg lower than that before surgery. There was no significant difference between the two groups relative to the effect of intraocular pressure control (t = 1.44, P > 0.05). CONCLUSION: Phacotrabeculectomy, either with one-site approach or with two-site approach, can provide good intraocular pressure control. The effects are similar between the two approaches in soft cataract patients.

Adult↗

PubMed2001

[Expression of vimentin in lens epithelial cells of age-related cataract].

OBJECTIVE: To observe the expression of vimentin in the lens epithelial cells and superficial cortex of age-related cataract. METHODS: Twenty-six paraformaldehyde-fixed flat preparations of human lens epithelium attached to the anterior capsule and obtained during extracapsular cataract extraction were studied. Of these, 22 were studied and compared to the 10 samples from normal lenses with antibody to vimentin by avidinbiotinylated peroxidase complex (ABC) method and observed with a light microscope, and 6 (4 cataractous and 2 normal) were used for pre-embedding immunoelectron microscopy. Vimentin in superficial layers (epithelium and superficial cortex) of 4 cataractous lenses were analysed by SDS-polyacrylamide gel electrophoresis (PAGE) and Western blot method. RESULTS: The average gray level values for expression of vimentin were 143.84 +/- 8.52 and 134.87 +/- 14.27 in cataract and normal group, respectively (t = 2.0948, P < 0.05). Ultrastructure of epithelial cells showed a decrease of intermediate filaments, accumulation of vimentin in bundle and organelle degeneration. Vimentin was identified in the superficial layers of normal and immature cataractous lenses by SDS-PAGE and Western blot. In another two mature cataractous lenses, little vimentin was detected. CONCLUSION: Decrease of vimentin may be initiated by damage to the epithelial cells leading to degradation of cytoskeleton, and appears to be related with the formation of age-related cataract.

Adult↗

PubMed2001

[Quantitative studies on expression of peripheral blood CD44 and CD54 in non-small cell lung carcinoma].

OBJECTIVE: To assess the relationship between expression of peripheral blood CD44 and CD54 in lymphocyte with non-small cell lung cancer and clinicopathological features. METHODS: Peripheral blood CD44 contents in 50 patients with lung cancer were detected by flow-cytometry, 30 normal donors and 25 patients with benign lesions served as controls. RESULTS: Peripheral blood CD44 and CD54 in lymphocyte with lung cancer were significantly higher than those in benign lesions and normal controls (P < 0.01). There is no distinct difference between CD44 and CD54 in benign lesions and normal controls (P > 0.05). Lung cancer with lymph node metastasis showed higher expression of CD44 and CD54 than lung cancer without lymph node metastasis (P < 0.01). Distinctly statistic difference was showed between CD44 in stage III, IV and stage I, II (P < 0.01). CD54 content in stage IV was higher than that in stage I, II and III, respectively. Histopathological grade was significantly associated with the expression of CD44 and CD54. Peripheral blood CD44 and CD54 contents were not related with squamous cell carcinoma and adenocarcinoma. CONCLUSION: Detection of CD44 and CD54 levels by flow cytometry might be used as a marker to evaluate prognosis and metastasis in patients with non-small cell lung cancer.

Adult↗

PubMed2001

Hepatic angiomyolipoma: a clinicopathologic study of 10 cases.

OBJECTIVE: To study the clinicopathologic features of hepatic angiomyolipoma (AML) and to investigate the feasibility of a new antibody-A103 as a diagnostic aid for AML. METHODS: Ten cases of AML were retrieved from hospital records and analyzed morphologically. Immunohistochemistry was performed on paraffin-embedded tissues with a panel of antibodies, including antibody-A103. RESULTS: There were eight women and two men, with ages ranging from 38-58 years (median 45.7). Clinically, nine cases were asymptomatic and found by imaging techniques. None of the patients had associated tuberous sclerosis. All tumors were sharply demarcated from the surrounding liver parenchyma. Histologically they were composed of a heterogeneous mixture of three components: thick-walled blood vessels, spindle or epithelioid smooth muscle cells and adipose tissue. All tumors showed a strong immunoreactivity to A103, HMB-45 and smooth muscle actins. Follow-up information on all 10 cases showed a benign course with no signs of recurrence. CONCLUSIONS: Hepatic AML is a rare mesenchymal tumor of the liver. A103 is a promising marker for a pathologic diagnosis of hepatic AML.

Actins↗

PubMed2001

Primary studies on heroin abuse and injury induced by oxidation and lipoperoxidation.

OBJECTIVE: To further reveal serious risks of heroin abuse to human body and clarify grave injuries of oxidation, peroxidation and lipoperoxidation induced by nitric oxide and other free radicals to heroin abusers. METHODS: Determined and compared plasma levels of nitric oxide (P-NO), vitamin C (P-VC), vitamin E (P-VE), beta-carotene (P-beta-CAR), lipoperoxides (P-LPO) and erythrocyte activities of superoxide dismutase (E-SOD), catalase (E-CAT), glutathione peroxidase (E-GSH-Px) and erythrocyte level of lipoperoxides (E-LPO) in 137 cases of heroin abusers (HAs) and 100 cases of healthy volunteers (HVs), used linear regression and correlation, stepwise regression and correlation to analyze correlation among heroin-abusing-duration (HAD), daily-heroin-abusing-quantity (DHAQ) with above determination values in the HAs. RESULTS: Compared with the above average values in the HVs group, the average values of P-NO, P-LPO, E-LPO in the HAs group were significantly increased (P < 0.0001), the average values of P-VC, P-VE, P-beta-CAR, E-SOD, E-CAT and E-GSH-Px were significantly decreased (P < 0.0001); the analysis of linear regression and correlation showed that with ascending of the HAD and DHAQ in the HAs, the values of P-NO, P-LPO, E-LPO were gradually increased (P < 0.0001), the values of P-VC, P-VE, P-beta-CAR, E-SOD, E-CAT, E-GSH-Px were gradually decreased (P < 0.0001); the analysis of stepwise regression and correlation suggested that the correlation among the HAD, DHAQ with the values of P-NO, P-VC, P-VE was the closest. CONCLUSION: The balance between oxidation and antioxidation in the HAs was seriously destroyed, and the injuries induced by nitric oxide and other free radicals, oxidation, peroxidation and lipoperoxidation reactions to the body of HAs gravely exacerbated. In the abstaining from heroin dependence, therefore, it should consider that sufficient quantum antioxidants such as VC, VE and beta-CAR are dosed to the HAs so as to abate the injuries to their bodies.

Adult↗

PubMed2001

Influence of growth hormone-insulin-like growth factor I axis on normal pregnancy.

OBJECTIVE: To investigate the role of growth hormone-insulin-like growth factor I (IGF-I) axis in normal pregnancy. METHODS: Totally, 116 normal pregnant women were recruited from January 1997 to June 1998, with 20 normal nonpregnant women as controls. Maternal growth hormone (GH) and IGF-I concentrations were assayed by RIA and enzyme-linked immunosorbent assay, respectively. RESULTS: Maternal serum levels of GH increased throughout gestation, reached a peak at 25 weeks of pregnancy and remained fairly high (chi 2 = 40.458, P < 0.0001). There was a significant difference between samples at 5-9 week gestational age and the controls (3.45 micrograms/L vs 1.61 micrograms/L, P < 0.05). The maternal serum levels of IGF-I increased rapidly throughout gestation from 29-week gestation and reached a peak of 188.86 micrograms/L at term delivery (chi 2 = 50.224, P < 0.0001). CONCLUSIONS: Maternal GH levels increased progressively throughout gestation, which correlated with fetal growth. Maternal GH may regulate nutrition supply among mother, placenta and the fetus and play an important role in transporting nutritional substrates by the placenta. The maternal IGF-I in the third trimester may promote fetal growth and placental functions.

Adult↗

PubMed2001

[A comparative clinical study of carboplatin solution and carboplatin powder].

OBJECTIVE: To observe the efficacy and side effects of carboplatin solution in comparison with carboplatin powder. METHODS: A multicenter, open randomized controlled trial was carried out. A total of 121 patients with small cell lung cancer (SCLC), non-small cell lung cancer (NSCLC) and breast cancer (BC) were randomized into carboplatin injection group (study group) and carboplatin powder group (control group), treated with CE, CIE and CAF protocol, respectively. The same drugs and dosage were used in the two groups. RESULTS: The response rate of the study group and the control group was 94% and 67% in SCLC (P > 0.05), 12% and 22% in NSCLC (P > 0.05) and 71.4% and 67% in BC (P > 0.05), respectively. The major side effects were myelosuppression and gastrointestinal reactions, the frequency and intensity of which were statistically not different in the 2 groups of patients. CONCLUSION: Carboplatin solution is as effective as carboplatin powder for the treatment of cancer.

Antineoplastic Agents↗

PubMed2001

[Gene apoptosis expression profiles in liver cancer and their comparison to normal peri-cancerous liver tissues].

OBJECTIVE: To describe a few gene expression profiles related to apoptosis and to demonstrate their difference between the liver cancer and its adjacent normal tissues. METHODS: cDNA, labeled as a-32P dATP was synthesized from the total RNA of cancer and adjacent normal tissues and, then, hybridized individually with two identical array membranes of Atlas human cancer dDNA expression containing 588 known genes. The method involving gene-specific semi-quantitative reverse transcription in the polymerase chain reaction (RT-PCR) was used to confirm the expression pattern of three known genes. RESULTS: Autoradiographic results were analyzed by specific AtlasImage (version 1.01a) software. Among 69 genes that were found to be related to apoptosis, 4 were up-related, including Aktl, and 19 were down-related, including BAK, Caspase-3, etc., all being related to cancer. The RT-PCR results showed that the expression pattern of all genes was in agreement with the results of Atlas expression array. CONCLUSION: The result obtained from Atlas microarray provides a liver cancer-specific expression profile related to apoptosis. The discovery about the apoptosis related genes may yield some clues on the oncogenetic mechanism of liver cancer in the future. The differential hybridization technique of cDNA expression array involving the Atlas human cancer can become a useful method in the understanding of the development and progression of human cancer.

Apoptosis↗

PubMed2001

[Effects of metformin on hyperinsulinemic anovulation].

OBJECTIVE: To investigate the effects of metformin on serum testosterone (T) levels and ovulation in hyperinsulinemic women. METHODS: Twenty-nine patients with hyperinsulinemic anovulation were treated with metformin for 12 weeks. Among them 19 had history of clomiphene(CC) treatment with 11 cases failure. CC was given again after one month of metformin treatment. Serum T, luteinizing hormone, follicle-stimulating hormone, insulin(Ins) levels were measured after 4 weeks of treatment. Basic body temperature was also observed. RESULTS: Serum T and Ins levels declined significantly after 4 weeks of metformin treatment [(2.7 +/- 1.6) nmol/L Vs (1.9 +/- 1.0) nmol/L, (49.2 +/- 34.1) mU/L Vs (25.3 +/- 23.9) mU/L, P < 0.05, P < 0.05 respectively]. Eight cases ovulated spontaneously and 8 cases with history of CC failure became ovulatory during CC treatment. CONCLUSIONS: Metformin is effective for suppressing serum T levels and improving the outcome of ovulation.

Adult↗

PubMed2001

[Influence of transfection of sense- and antisense-cyclin A gene on human squamous cell carcinoma of tongue].

OBJECTIVE: To investigate the effect of human sense- and antisense-cyclin A gene on human squamous cell carcinoma of tongue cell line (Tca 8113). METHODS: Tca8113 cells were transfected with an expression vector containing a full length human sense-cyclin A or antisense-cyclin A gene by gene transfer with DNA-liposome. A series of methods, such as the changes of cell proliferation, DNA-flow cytometric analysis, silver binding nucleolar organizer regions (AgNORs) and expressions of cyclin A and Ki-67 were studied on transfected cell and untransfected cell. RESULTS: The cells transfected by antisense-cyclin A gene showed growth inhibition in vitro and decreased proliferation. The proliferation index(PI) was reduced (0.231 vs 0.421) as compared with untransfected cell group, and FCM analysis showed that Tca8113 cells transfected with antisense-cyclin A were arrested at G0/1 phase. The mechanism of such changes described might be associated with the lower expression of cyclin A mRNA in antisense-cyclin A gene transfected cells. However, opposing changes were observed in the sense-cyclin A gene transfected cells. CONCLUSIONS: Antisense cyclin A could inhibit target gene expression and partly reverse malignant phenotype of squamous cell carcinoma of tongue.

Carcinoma, Squamous Cell↗

PubMed2001

[Physiological indices for evaluating iron-toxicity tolerance of rice (Oryza sativa L.)].

This paper studied the content malodialdehyde (MDA) and the leakage rate of electrolyte in leaves of various rice varieties with different iron-toxicity tolerance and of Echinochloa crusgalli under excessive Fe2+ (160 mg.L-1) stress. The results showed that both the MDA content and the leakage rate of electrolyte in leaves of plants were significantly and negatively correlated with the tolerance of test plants to iron toxicity. It was suggested that both MDA content and leakage rate of electrolyte could be used as the index for evaluating the tolerance to iron toxicity.

Biomass↗

PubMed2001

The regulatory effect of ERK1/2 signal pathway on production of TNFalpha induced by LPS in mice Kupffer cells.

OBJECTIVE: To study the rule of ERK1/2 activity and regulative effect of ERK1/2 pathway on the production of pro-inflammatory cytokine TNFalpha in mice Kupffer cells (mKC) induced by LPS, and to exploring novel methods to prevent and treat clinical patients of endotoxemia. METHODS: Immunoprecipitate kinase assay and Western blotting analysis were used to detect the phosphorylated ERK1/2 kinase activity in mKC stimulated by LPS, and ELISA was used to study the effect of ERK1/2 signaling cascade on LPS-induced TNFalpha production in mKC. RESULTS: In mKC, LPS treatment resulted in transient and rapid increase of kinase activity of ERK1/2 that phosphorylated their specific substrate ELK-1, with maximal value at 30 minutes and a return near to baseline within 2 hours, and LPS-induced ERK1/2 activity from LPS concentration of 10 pg/ml to the top activity at 100 ng/ml. No activity was observed in unstimulated mKC. Inhibition of the ERK1/2 pathway using the specific ERK1/2 signal pathway inhibitor PD98059 caused a marked and concentration-dependent reduction of TNFalpha production. CONCLUSIONS: The results show that LPS can markedly activate ERK1/2 pathway in mKC. PD98059 causes a significant and concentration-dependent reduction of TNFalpha production. ERK1/2 may be a novel target to treat clinical patient of endotoxemia.

Animals↗

PubMed2001

[In vivo and in vitro effects of selenium-enriched garlic on growth of human gastric carcinoma cells].

OBJECTIVE: To compare the effects of selenium-enriched garlic (Se-garlic), garlic, Na2SeO3, and garlic + Na2SeO3 on growth of human gastric carcinoma cells. METHODS: In vivo and in vitro assays were carried out in the cultured human gastric carcinoma cell line MGC803 transplanted in the nude mice by cell count, flow cytometry, Western blot and neoplasm volume measurement. RESULTS: The inhibition effect of garlic was similar to that of Se-garlic, but Na2SeO3 was weaker than Se-garlic. Combination of garlic and Na2SeO3 was stronger than Se-garlic. In flow cytometry assay, the proportion of G1 phase was increased after 24 hour treatment of Se-garlic, garlic and Na2SeO3 in the non-synchronized cells. However, the proportion of S phase was increased in the synchronized cells. The proportion of G2 + M phase was increased both in non-synchronized and synchronized cells on treatment with the combination of garlic and Na2SeO3. The amount of Cdk2-CyclinE complex and Cdk4-CyclinD1 complex was decreased in all treated synchronized cells in immunoprecipitation and immunoblot assays. The growth of MGC803 tumor in male Balb/c nude mice was inhibited by administration of 1.67% of Se-garlic (Se 2 micrograms/g) in diet with an inhibition rate of 29.92% in tumor weight. Treatment of either 0.83% of Se-garlic or 1.67% of garlic or 4.38 micrograms/g of Na2SeO3 (Se 2 micrograms/g) could not appreciably inhibit the growth of tumor. Wrapping of a number of monocytes around the tumor was induced in 62.50% of tumors in 0.83% of the Se-garlic group. CONCLUSION: In vitro, Se-garlic is able to inhibit the growth of MGC803 cell through action of garlic. In vivo, Segarlic is able to inhibit growth of MGC803 tumor in nude mice by being better than garlic and selenite.

Animals↗