Search PubMed⌕ Search

Biomedical subjects

X Zhou

Publications and source records attributed to X Zhou.

At least 361 records · Page 20Linked to original sources

[Genetic linkage of polymorphisms of type I angiotensin II receptor gene to Chinese Han hypertension].

OBJECTIVE: To observe the CA repeat polymorphism of the type I angiotensin II receptor gene on Chinese Han people, and evaluate the genetic linking to hypertension. METHODS: The CA repeat polymorphism at 3'-flanking region of AT1R gene was studied by amplified fragment length polymorphism (Amp-FLP ) in Chinese Han people from Shandong and Xi'an. RESULTS: There were 9 alleles ranging from 130bp to 146bp in all subjects. The allele frequencies were 0.01 to 0.38, and allele A4 was more frequent in the control. The heterozygosity of CA repeat locus was 0.789, the polymorphic information content, 0.746. There was no significant difference in distribution of CA repeat polymorphism genotype between different regions in same ethnic (P>0. 05), but the allele frequency of CA repeat polymorphism in hypertensive group was significantly different from that of control (P<0.05). There was no detectable distortion from Hardy-Weinberg equilibrium in both groups. CONCLUSION: The results suggest that CA repeat polymorphism of AT1R gene be associated with Chinese Han hypertensive people.

Adult↗

Pharmacology study of the neutral myocardial imaging agent technetium-99m-N(NOEt)2.

OBJECTIVE: The biological properties of a new neutral myocardial imaging agent 99mTcN(NOEt)2 were evaluated. METHODS: Blood clearance in rabbits, biodistribution in rats, and initial myocardial imaging in dogs were performed. RESULTS: Radiochemical purity of 99mTcN(NOEt)2 was more than 90% and stable for 6 h at room temperature. Blood disappearance was analyzed with a biexponential model and T1/2(alpha) = 2.53 min, T1/2(beta) = 330 min and CI = 378 ml/h were obtained. Biodistribution studies demonstrated that 99mTcN(NOEt)2 localized selectively in the rat myocardium. Cardiac uptakes were 4.69, 4.20, 3.95 and 3.43% ID/g at 5, 30, 60 and 90 min postinjection, respectively. The mean heart-to-lung activity ratios were 1.69, 2.40 and 2.55 at 10 min, 30 min and 60 min postinjection, respectively. CONCLUSION: Technetium-99m-N(NOEt)2 exhibited favorable stability and biological properties. Further study in humans is required.

Animals↗

[The relation between mitochondrial DNA mutation and aminogly- coside antibiotics-induced deafness].

OBJECTIVE: To nvestigate the relation between mitochondrial DNA mutation and aminoglycoside antibiotics-induced deafness. METHODS: Mitochondrial DNA (mtDNA) of peripheral blood from 48 sporadic cases was analysed using PCR-BsmAI digestion and PCR-direct DNA silver sequencing. RESULTS: Six of 48 sporadic patients had A to G mutation in 12S rRNA gene of mtDNA at nucleotide 1555. CONCLUSION: The results suggest that mtDNA 1555(G) mutation is related to the occurring of aminoglycoside antibiotics-induced deafness which can cause genetic susceptibility to aminoglycoside antibotics ototoxicity.

Adolescent↗

Synaptic activation and properties of 5-hydroxytryptamine(3) receptors in myenteric neurons of guinea pig intestine.

The contribution of 5-hydroxytryptamine (serotonin; 5-HT) acting at 5-HT(3) receptors to fast excitatory postsynaptic potentials (fEPSPs) and the properties of 5-HT(3) receptors in the guinea pig small intestinal myenteric plexus were investigated using electrophysiological methods. In 11% of neurons studied in the acutely isolated myenteric plexus, ondansetron (1 microM) inhibited hexamethonium (100 microM)-resistant fEPSPs. 5-HT elicited an inward current in neurons maintained in primary culture. The peak current reached maximum in <150 ms and desensitized with a double exponential time course (tau1 = 1.1 +/- 0.1 s; tau2 = 6.9 +/- 0.9 s). The whole-cell current/voltage relationship was linear, with a reversal potential of 2.7 +/- 1.5 mV. The rapidly activating and desensitizing current was completely blocked by ondansetron (1 microM) and partly inhibited by d-tubocurare (1 microM). The 5-HT(3)-receptor agonist, 2-methyl-5-HT (100 microM), caused a peak current that was 18% of the peak current caused by 5-HT in the same cells; 2-methyl-5-HT (1 microM) inhibited currents caused by 5-HT. 5-HT-activated single-channel currents in outside-out patches; this response was blocked by ondansetron. The single-channel conductance was 17 +/- 1 pS. The single-channel current/voltage relationship was linear between -110 and 70 mV and had a reversal potential near 0 mV. These data indicate that 5-HT contributes to fEPSPs in the myenteric plexus. The 5-HT(3) receptor expressed by guinea pig myenteric neurons has pharmacological and electrophysiological properties that distinguish it from 5-HT(3) receptors expressed by other autonomic neurons and neurons in the central nervous system.

Animals↗

Selection of quantitative criteria for evaluating metastases of a highly metastatic salivary adenoid cystic carcinoma cell line to the lungs of nude mice.

OBJECTIVE: To select reliable quantitative criteria for evaluating metastases of a highly metastatic salivary adenoid cystic carcinoma cell line (ACC-M) cell to the lungs of nude mice. MATERIALS AND METHODS: The within-group coefficients of correlation of 5 parameters were measured from lung slides using a video image digital analysis system (VIDAS), and the intergroup coefficients of correlation of 6 sets of parameters from all the lungs, which were taken from ACC-M lung metastases models, were calculated and statistically analyzed. RESULTS: The within-group coefficients of correlation of 5 parameters are as follows: ratio of area of metastases, t = 0.9 (P < 0.001); area of metastases, t = 0.7 (P < 0.05), size of lung section, numbers of metastases, and size of the largest metastatic focus all t < 0.4 (P > 0.05). The intergroup coefficients of correlation of the parameters are as follows: ratio of area of metastases was assigned 1, weight of the lung was 0.9755, and area of metastases was 0.8628. CONCLUSION: For evaluating lung metastases of ACC-M, the ratio of area of metastases and weight of the lung are precise; the area of metastases is also significant within the 6 quantitative parameters.

Animals↗

Enhanced efficacy of the combination of all-trans-retinoic acid and gamma-interferon in inhibiting proliferation of Tca8113 cells.

OBJECTIVE: To develop a more effective induced-differentiation or -apoptosis therapy for treating oral squamous cell carcinomas. METHODS: The combination of all trans retinoic acid (ATRA) and interferon-gamma (IFN-gamma) was tested for its antiproliferative activity against human tongue squamous cell carcinoma cell line (Tca8113 cells) in vitro. Clonogenic assay, MTT assay, and microscopic cell analysis were performed in this experiment. RESULTS: The results show that the combination of ATRA and IFN-gamma can produce synergistic antitumor effects, resulting from induction of apoptosis, on Tca8113 cells. CONCLUSION: The combination of ATRA and IFN-gamma is a more effective induced-apoptosis therapy for treating oral squamous cell carcinoma.

Apoptosis↗

[The influences of genetic and environmental factors on plasma plasminogen activator inhibitor-1 levels in patients with essential hypertension].

OBJECTIVE: To investigate the influence of a 4G/5G polymorphism in the PAI-1 gene promoter and environmental factors on plasma plasminogen activator inhibitor-1(PAI-1) levels in subjects with essential hypertension. METHODS: A total of 240 patients with essential hypertension(males 120, females 120, aged 33-89 years, mean 65 years) were randomly enrolled in this study. Plasma PAI-1 antigen was measured by ELISA. The 4G/5G polymorphism was analyzed by the allele specific oligonucleotide hybridization method. RESULTS: Plasma PAI-1 levels were significantly associated with 4G/5G polymorphism with the highest levels occurring in subjects with 4G/4G genotype, the intermediate levels in 4G/5G subjects and the lowest levels in 5G/5G subjects. 4G/5G polymorphism, diabetes mellitus and triglyceride(TG) were three independent predictors of plasma PAI-1 levels in a stepwise multiple regression model. Furthermore, the relationship between plasma PAI-1 levels and TG was genotype dependent. CONCLUSION: Plasma PAI-1 levels are not only under genetic control, but also influenced by several environmental factors. There is an interaction between genetic and environmental factors.

Adult↗

Replacement vectors for localized gene cloning in the specified region of Streptomyces lividans 66 and model method for the screening of desired recombinants via counter-selection.

Two DNA fragments (3.5 kb and 3.8 kb in size) flanking both ends of the phi HAU3R gene in the genome of Streptomyces lividans 66 were determined and cloned in their natural relative orientations in pIJ653, a cosmid vector derived from the multi-copy Streptomyces plasmid pIJ101, resulting in pHZ806. After insertion of spectinomycin/streptomycin (spc/str) resistance gene into the pIJ101 replication region in pHZ806 and insertion of a hygromycin (hyg) resistance gene between 3.5 kb and 3.8 kb DNA fragments, a new vector with a non-functional Streptomyces replicon, pHZ808, was obtained. In principle, any DNA fragment cloned between 3.5 kb and 3.8 kb fragments of this vector can be stably integrated between the two corresponding regions after introduction into the wild-type S.lividans strains, with synchronous replacement of the DNA between the two regions of the chromosome within which phi HAU3R gene is located. The resultant recombinant strains will thus become phi HAU3-sensitive (phi HAU3S). This phenotype could serve as a good indication that the desired gene replacement has occurred. This principle was demonstrated to be successful using pHZ808 as vector. phi HAU3-resistance gene (phi HAU3R) from the genome of S.lividans 66 was substituted by the hygromycin resistance gene (hyg) from pHZ808. An additional advantage of using pHZ808 as the vector to clone foreign genes is that hyg could be served as a reportor gene to imply that foreign DNA fragment has been co-integrated with hyg. The recombinants will have both hygR and phi HAU3S.

Anti-Bacterial Agents↗

Cloning and expression of truncated PTHrP receptor in Escherichia coli.

To evaluate the effects of recombinant soluble parathyroid hormone related protein receptor(sPTHrPR), the RNA prepared from renal cell carcinoma was reverse-transcribed and amplified by a polymerase chain reaction(PCR). A 543 base pair fragment corresponding to extracellular domain of PTHrPR was obtained and cloned. Sequencing was performed by the dideoxy chain-termination method. Comparison of the nucleic acid sequence with the published data revealed that only one nucleotide had changed. A high level expression vector referred to as pET-3a/sPTHrPR was constructed. The binding specificity of the expression products was proved by indirect ELISA. Our preliminary experiment also showed that the expression products can block the biological activity of PTHrP.

Amino Acid Sequence↗

[Effect of liposome-C-erbB2 antisense oligodeoxynucleotides on the growth and the chemotherapeutic drug sensitivity of human ovarian cancer transplanted in the omentum of nude mice].

OBJECTIVE: To investigate the effects of liposome-C-erbB2 antisense phosphorothioate oligodeoxynucleotides(S-ODNs) on the growth and the chemotherapeutic drug sensitivity of human ovarian cancer transplanted in the omentum of nude mice. METHODS: Human ovarian cancer transplanted in the omentum of nude mice model was established, then divided into four groups: control group, experimental group, chemotherapeutic group, and experimental + chemotherapeutic group. Different treatments were given respectively. The weight of nude mice was observed and the morphology of tumor cells was observed by electromicroscope. RESULTS: The growth inhibitory rate in the experimental group was 37%. There were more heterochromatins in the treated tumor cells. The growth inhibitory rate in the experimental + chemotherapeutic group was increased to 50%. There was no obvious alteration in the weight of experimental group. CONCLUSION: The data in this study suggest that antisense therapy is an useful method of gene therapy in ovarian cancer; Moreover, it could enhance the effectiveness of antitumor drug.

Animals↗

[Study of histopathology of endometrium following termination of early pregnancy using mifepristone].

OBJECTIVE: To explore the causes of abnormal uterine bleeding following termination of early pregnancy using mifepristone. METHODS: 19 specimens were obtained by curettage on the day immediately after expulsion of gestational sac, 40 specimens on the 7th postabortal day and 20 specimens during 2-12 weeks after induced abortion using mifepristone respectively. The histopathologic changes of the specimens were observed by HE staining, and the expression of human choronic gonadotropin (hCG) and human placental lactogen (hPL) by immunohistochemical studies as well as phloxine-tartrazine staining and Gordon Sweets staining. RESULTS: It showed that decidua shedding retarded, especially basal decidua. Immunohistochemical studies demonstrated the trophoblasts were still active and might affect pathological changes of local endometrium. The specific granules of endometrial granulocytes disappeared, together with disintegration of the reticular fibers. But in the group which curettage was indicated for abnormal bleeding 2 weeks after abortion, the main cause was incomplete abortion. CONCLUSIONS: In addition to incomplete abortion, the retardation of decidua shedding and the impairment of endometrium regeneration were responsible for the abnormal uterine bleeding following termination of early pregnancy using mifepristone. The incomplete dissolution of the reticular fibers in basal decidua may induce decidua shedding retardation and incomplete abortion.

Abortifacient Agents, Nonsteroidal↗

[Effect of mifepristone on cell-cycle kinetics of human placental chorio-trophoblastic and decidual cell].

OBJECTIVE: To study the effects of mifepristone on cell-cycle kinetics of human placental chorio-trophoblastic and decidual cells. METHODS: Flow-cytometry was introduced in the study of the mechanism of early pregnancy terminating drug, mifepristone. Twenty-three samples were obtained from normal pregnant women by surgical aspiration. Another 24 samples were obtained in women pretreated with 150 mg mifepristone 48 hours before operation. RESULTS: The percentage of the cytotrophoblastic cells in G0 + G1 phases was much higher in the treatment group (P < 0.01), whereas it was much lower (P < 0.01) in G2 + M phases, and the proliferating index of cells was significantly decreased. Apart from the increasing of decidual cells in G2 + M phases (P < 0.05), there was no change in other phases. CONCLUSIONS: Mifepristone may block the transformation of the cytotrophoblastic cells from G0, G1 phases to S phase, thus leading to the block of the proliferation of cells. Mifepristone has much more significant effects on the chorionic villi than on the decidua.

Abortifacient Agents, Steroidal↗

[Serum levels of levonorgestrel during long-term use of Norplant].

OBJECTIVE: (1) Assessment of longest effective contraceptive duration of Norplant (containing levonorgestrel, LNG) by serum levonorgestrel levels. (2) To observe the possible relationships between the serum LNG levels of long-term use (5 years) and body weight. METHODS: To determine serum LNG levels in 230 women among 1,356 cases at various intervals between 1 and 11 years after implantation using RIA kits provided by WHO. RESULTS: The average serum levels of LNG in users of Norplant at the 1st, 3rd, 5th years were 1,273.5, 924.0 and 739.6 pmol/L respectively. From the 5th to 7th years average serum LNG levels showed almost a linear decline, and from the 7th through 10th year it did not show much changes. The average serum LNG level was (511.1 +/- 209) pmol/L. A significant negative correlation was found between serum LNG levels and body weight at the 5th years. CONCLUSION: One set of Norplant implants may provide effective contraception for 8-10 years in women with body weights less than 60 kg.

Adult↗

[The activities of proteolytic enzymes in dental plaque of patients in different age-sex groups].

This study was intended to explore the relationship between the proteolytic enzymes in dental plaque and the patient's age and sex. Fluorometry and spectrometry were used to separately determine the activities of leucine amino peptidase, dipeptidyl peptidase IV and trypsin-like proteinase in children(10 boys and 10 girls), adults(n = 20) and elderly people(n = 10). The results showed that sex almost had no influence on the activities of the three enzymes in dental plaque in the children(P > 0.05), and with the increase of age, the activities of the three enzymes apparently increased (P < 0.01). These findings imply that the proteolytic enzymes may only play important roles in root lesions.

Adolescent↗

Association of polymorphism of apolipoprotein E gene with coronary heart disease in Han Chinese.

OBJECTIVE: To investigate the association between apolipoprotein E (apoE) gene polymorphism and coronary heart disease(CHD) in Han Chinese. METHODS: Apo E genotype was examined with the methods of hot start polymerase chain reaction (PCR) and restriction isotyping in samples of 113 unrelated Chinese healthy individuals and 93 patients with CHD. The relation of the gene polymorphism of apoE and levels of serum lipids, lipoproteins, and apolipoproteins was also studied. RESULTS: The results showed that the epsilon 4/3 genotype was more frequent in CHD cases than in control subjects (31.2% vs. 11.5%, P < 0.01). The frequency of the epsilon 4 allele in CHD cases was significantly higher than in control subjects (17.2% vs 7.5%, P < 0.01). The epsilon 4 allele was associated with high concentrations of serum TC (r = 0.265, P < 0.05), LDL-C (r = 0.266, P < 0.05), and apoB (r = 0.360, P < 0.01). CONCLUSIONS: Hot start PCR assay is considered a rapid and simple technique for apoE genotyping. This method is suitable for routine laboratories and large scale population studies. Genetic polymorphism of the apoE gene might contribute to the determination of serum lipid profile and the development of CHD among Han Chinese.

Alleles↗

[Effects of low-dose tritiated water on the developing central nerve system and their mechanisms].

OBJECTIVES: To provide experimental data for evaluating tritium risk of nuclear-energy plant and instituting safety protection standard of nuclear effects of low-dose tritiated water(HTO) on the developing central nerve system. METHODS: Pregnant adult C57BL/6J strain mice and Wistar rats were irradiated with beta-rays from HTO by a single intraperitoneal injection on the 12.5th and 13th day of gestation. The activity of HTO was (x 10(4) Bq/g. B.W) 24.09, 48.18 and 144.54, respectively. Neurobehavior and learning and memory ability were tested. Ca2+ currents of hippocampal neurons were examined by patch-clamp. Apoptosis of brain cells was detected morphologically and biochemically by DNA electrophoresis. SDS-PAGE and Western blotting were used to detect P53 protein in the cultures. RESULTS: After irradiation with beta-rays from HTO in utero, the offspring showed hyperactivity in their young age period and then showed depression-hypoactivity in adulthood. The exposed animals had difficulties in both learning and memory retention and the developing neurons of the central nerve system showed lower Ca2+ currents, higher number of apoptosis, a typical "ladder pattern" DNA and increasing P53 protein. CONCLUSIONS: Lower Ca2+ currents, higher number of apoptosis of brain cells and abnormal expression of P53 protein were the substance basis of the damage of central nerve system caused by tritium.

Animals↗

Surgical treatment of hepatocellular carcinoma and related basic research with special reference to recurrence and metastasis.

OBJECTIVE: To summarize the progress of surgical treatment of hepatocellular carcinoma (HCC) and related basic research at the Liver Cancer Institute of Shanghai Medical University in the recent years, with special reference to recurrence and metastasis. METHODS: Published and unpublished update clinical and experimental data in the above-mentioned areas are summarized. RESULTS: Surgical resection has played an important role in improving prognosis of HCC, the 5-year survival were 63.4% for small HCC resection (n = 806), 39.6% for large HCC resection (n = 1061), 64.7% for cytoreduction (using hepatic artery cannulation and ligation) and sequential resection of initially unresectable HCC (n = 93), 56.0% for cytoreduction using transcatheter arterial chemoembolization (TACE) and followed by resection (n = 65), and 22.4% for hepatic resection with removal of tumor thrombi in portal vein (n = 103). Unfortunately, the 5-year recurrent rate after curative resection of HCC was up to 61.5%, which was mainly a result of intrahepatic "metastasis" and multicentric origin of HCC. Clinically, re-resection of subclinical recurrence yielded 56% of 5-year survival (n = 202); prevention of recurrence by transcatheter arterial chemoembolization (TACE) + Interferon, or LAK/IL-2 therapy have decreased 3-year recurrent rate from 33% to 11%-18%. In experimental aspect, metastatic human HCC model in nude mice (LCI-D20) and HCC cell line with metastatic potential (MHCC97) have been established; studies on HCC invasiveness in the molecular level revealed similar results that reported in other solid cancers, and small HCC showed slightly better biological characteristics as compared with large HCC; microvessel density (MVD) that reflecting angiogenesis adversely correlated with 5-year survival of small HCC; experimental interventions using antisense H-ras, bispecific antibody, BB94, as well as anti-angiogenic agents (TNP470, suramin, CAI, heparin, antisense VEGF, etc.) have been demonstrated to inhibit tumor growth and lung metastasis in nude mice model. CONCLUSIONS: Recurrence and metastasis are the major obstacle to further improve prognosis of HCC, studies should be conducted both in clinical and experimental aspects, "HCC invasiveness" will be the major target to be studied, particularly in the molecular level, and anti-angiogenesis will be one of the important approach.

Angiogenesis Inhibitors↗

[CT in diagnosis of tuberculosis of liver and spleen].

OBJECTIVE: To analyze CT findings of hepatospleeno-tuberculosis and to explore the characteristics for diagnosis and differential diagnosis of the disease. METHODS: CT scans were performed in fifteen patients. There were nine men and six women, the age ranging from 18 to 60 years old. All patients were diagnosed clinically, one of which was confirmed by pathology after surgery, two of which were confirmed by pathology through CT-guided biopsy. RESULTS: All cases were concurrent with two or more other tuberculosis. Disseminated milliary, small nodules and small saccular foci were present in livers of 8 cases and spleens of 5, and isolated low dense lesion in liver of 1 case, diffuse calcifications in liver and spleen of another 1. CONCLUSIONS: When disseminated milliary, small nodules and small saccular foci are found by CT in liver or spleen and tuberculous lesions are present in other tissues, diagnosis of liver and/or spleen tuberculosis should be considered.

Adolescent↗