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Biomedical subjects

H Wang

Publications and source records attributed to H Wang.

At least 901 records · Page 50Linked to original sources

[Study on the carcinogenic mechanism of human papillomavirus typel6 E7 protein in cervical carcinoma].

OBJECTIVE: To determine the relationship between HPVl6 E7-Rb protein binding (Rb protein was dissociated from pRb-E2F-l complex) and the occurrence of cervical carcinoma. METHODS: HPV16 DNA infection rate was tested in cervical carcinoma and normal cervical tissues by polymerase chain reaction (PCR) technique. Then using Western blot analysis to find the presence HPVl6E7 protein and pRb-E2F-1 complex in HPV16 DNA positive cervical carcinoma tissues. The normal cervical tissues were used as control. RESULTS: Out of 67 samples with cervical carcinomas, 34 samples were HPV16 DNA positive (50.7%), no HPVl6 DNA were detected in 10 samples of normal cervical tissues. In cervical carcinoma tissues, the HPV16E7-pRb complex, the free E2F-1 were detected by Western blot, but no complex of pRb-E2F-l was found. CONCLUSIONS: Our results seem to suggest that HPV 16 E7 protein could interact with pRb through separating the complex of pRb-E2F-1, release free E2F- 1, resulted in disordered cell cycle and cell malignant transformation.

Blotting, Western↗

[Ecological effect of CdCl2 on plasmid and role of plasmid in Cd-tolerance of its host].

After treating the plasmid of Escherichia coli HB101 by CdCl2 in vitro or in vivo, the effect of Cd on the structure of plasmid pWH58 DNA was studied through argarose gel electrophesis and restriction fragment length polymorphism analysis. By comparing the growth of E. coli with and without plasmid cultured in the medium with Amp LB and non-anti LB under different concentrations of CdCl2, the effect of Cd on plasmid E. coli of in vivo and the role of plasmid in Cd-tolerance of its host were studied. Cd treatments of E. coli in vitro or in vivo didn't cause an obvious change of the structure of plasmid pWH58 DNA. Plasmid pWh58 could replicate for regeneration and gene express under Cd stress. Plasmid pWH58 of E. coli in vivo lowered Cd-tolerance of its host form 75 mg.L-1 to 50 mg.L-1. Cd-tolerance of E. coli ascended markedly after Cd taming, but had a trend of reversing to original level after restoration, indicating that Cd-tolerance of E. coli could be tamed, but the tamed Cd-tolerance still had no genetic basis.

Cadmium Chloride↗

[Effect of nitrogen on water use efficiency of apple tree].

This paper studied the effect of nitrogen fertilizer on water use efficiency(WUE) and relevant parameters of two years old potted apple trees(Starkrimson/Malus hupenensis) under different soil moisture condition. The results showed that under adequate soil moisture, WUE was decreased with increasing application of nitrogen fertilizer. Nitrogen fertilizer application resulted in an increase of stomatal conductane. Consequently, the transpiration rate was increased more than photosynthetic rate did. Under soil drought, the WUE of plants applied with nitrogen fertilizer was apparently higher than that of control. The WUE value was in the order of high N > medium N > low N. The improvement of WUE was due to the increase of mesophyll capacity, which led to the promotion of photosynthesis.

Malus↗

[Root excretion and plant resistance to metal toxicity].

Reducing the availability and toxicity of metal pollutants before they enter plant body is one of the main mechanisms of plant resistance to metals. Root system is the first entrance of metal pollutants from soil into plant. It can excrete organic acids, amino acids, sugars, growth substances etc. into rhizosphere. Root excretion affects the metal absorption by plant through changing the physical and chemical characters(such as pH, Eh) of rhizosphere. The metal pollutants are detained outside the roots by chelation, complexation and disposition with root exudates. The quantity and activity of metals in rhizosphere are changed by root exudates through changing the composition, activity and excretion of microbes there. After reviewing the research advances on root excretion and plant resistance to metals, the authors pointed out the existing problems and the major topics and significance of further research.

Environmental Pollutants↗

[Numerical simulation on maize growth in a regular windbreak system in Huanghuaihai Plain].

The modified production ecological model SUCROS was used to simulate the growth process of summer corn with the protection of windbreaks in Huanghuaihai Plain, and the simulated result was compared with the field monitoring data. The effects of various physiological and ecological factors that affect the growth of the summer corn were analyzed. The modified SUCROS could simulate the growth process successfully. The leaf area index and organ biomass simulated by the model could be fairly consistent with the monitoring data when the effects of insect and disease pests and weeds were considered simultaneously. As compared with the simulated data in the monoculture field, the corn yield in the windbreak system was about 6.8% higher due to the improved microclimate. Based on the simulation of the relationships between sowing density, sowing date and seed production, the density standard for high yield in the region was 6.75-7.50 plants.m-2, even high as 9.00 plants.m-2 in the fields with sufficient soil nutrients and water supply. It is suggested that the optimal sowing period is from May 21 to June 5. Through simulating the influence of "cool summer" on the growth of summer corn in southern Huanghuaihai Plain, it was found that the growth period of corn would extend 3 to 4 days if the average air temperature during the growing period lowered by one degree. The "less radiation" and correspondent "lower temperature" were the direct reasons of yield reduction in "cool summer".

Biomass↗

Astragalus mongholicus and Angelica sinensis compound alleviates nephrotic hyperlipidemia in rats.

OBJECTIVE: To investigate the mechanism of lipid-lowering effect of the Astragalus mongholicus and Angelica sinensis compound (A&A) on nephrotic hyperlipidemia in rats. METHODS: Rats with nephrotic syndrome from accelerated nephrotoxic serum nephritis were used. They were divided into two groups: A&A treatment group and nephrotic control group. Normal rats were used as a normal control group. Serum lipids, serum lipoprotein lipase (LPL) and lecithin-cholesterol acyltransferase (LCAT) were assayed biochemically and enzymatically. mRNAs of hepatic hydroxy-methyl glutaryl-CoA reductase (HMG-CoA-R) and low-density lipoprotein receptor (LDL-R) were assessed by Northern blot. RESULTS: In nephrotic control group hyperlipidemia was found. The activities of serum LPL and LCAT were low. Hepatic HMG-CoA-R mRNA increased temporarily at the early stage while LDL-R mRNA decreased gradually. In A&A treatment group, serum total cholesterol (TC), triglyceride (TG), low-density lipoproteins (LDL) and very low-density lipoproteins (VLDL) were significantly lower than those in nephrotic control group. There was no change in the amount of hepatic HMG-CoA-R mRNA, but hepatic LDL-R mRNA and activities of serum LPL and LCAT increased significantly. CONCLUSIONS: A&A alleviates hyperlipidemia considerably in nephrotic rats. A&A improves disorders of lipid metabolism perhaps through up-regulating the expression of hepatic LDL-R gene and through increasing the activities of serum LPL and LCAT.

Angelica sinensis↗

Hemostatic abnormalities associated with acute promyelocytic leukemia and corrective effects of all-trans-retinoic acid or arsenic trioxide treatment.

OBJECTIVE: To study in vivo effect of all-trans-retinoic acid (ATRA) or arsenic trioxide (As2O3) on the expression of tissue factor (TF) and the hemostatic disorders, a series of parameters were measured in bone marrow blasts and plasma from acute promyelocytic leukemia (APL) patients. METHODS: The plasma variables were measured by ELISA or chromogenic study. The TF transcription was assessed using reverse transcription-polymerase chain reaction technique (RT-PCR). RESULTS: The blast cell procoagulant activity (PCA), TF antigen of APL cell lysates, as well as the transcription of APL TF mRNA elevated at diagnosis, were reduced after ATRA or As2O3 therapy. The plasma level of platelet alpha-granular membrane protein-140, soluble fibrinomonomer complex, thrombomodulin, tissue plasminogen activator and D-dimer significantly increased, fibrinogen, antigen level of protein C, plasminogen, alpha 2-plasminogen inhibitor and plasminogen activator inhibitor decreased at diagnosis, were restored to normal after complete remission but protein C activity and protein S remained elevated in ATRA group. CONCLUSIONS: There existed activation of platelets and consumption of anticoagulants as well as activation of coagulation and fibrinolytic system before treatment. Both ATRA and As2O3 therapy down-regulated the expression of TF mRNA, decreased the PCA and TF level in APL cells, inhibited coagulation activation, secondary hyperfibrinolysis and recorrected other hemostatic abnormalities, thus greatly improved the bleeding symptom in early stage of the treatment.

Adolescent↗

Mitochondrial gene variation in type 2 diabetes mellitus: detection of a novel mutation associated with maternally inherited diabetes in a Chinese family.

OBJECTIVE: To explore the relationship between type 2 diabetes mellitus and the mutation(s) in mitochondrial DNA. METHODS: According to the previous literature, the fragment of mitochondrial DNA from nucleotide 3153 to 3551, which had shown high frequency of point mutation, was scanned with the technique of polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) in Chinese normal control, type 2 diabetic population, and 12 families suffered from maternally inherited type 2 diabetes mellitus. Direct sequencing was applied to detect the fragments with abnormal conformation. RESULTS: No special band was found in SSCP electrophoreses in Chinese normal control, and only one subject (No. 81) of diabetic population indicated the abnormality in SSCP study, which was affirmed to be a silent point mutation of T to C at nucleotide 3336 inducing no change in amino acid (ATT-->ATC, Ile). Pedigree 25,001 was the only family that exhibited strongly different SSCP characteristic from the other 11 ones, which was confirmed to be caused by a single point mutation mt3285T-->C/T in the coding region of tRNA(Leu(UUR)) gene by the technique of direct sequencing. CONCLUSIONS: The variation within mt DNA 3153-3551 is not the major cause of type 2 diabetes in Chinese population suffered from this disease in this study. The point mutation T-->C/T at the mitochondrial nucleotide 3285, which was found in pedigree 25,001, is located in the highly conservative region of tRNA(Leu(UUR)) gene. It is strongly suggested that this mutation cause the conversion in the 3-dimentional structure of tRNA(Leu(UUR)), which might disturb the normal translation and lead to the impairment in mitochondrial oxidative phosphorylation characterized by the defects of the polypeptides involved in the respiratory chain. Thus, insulin secretion deficiency and insulin resistance might occur.

Adult↗

Decreased bone mineral density in female patients with systemic lupus erythematosus after long-term administration of Tripterygium Wilfordii Hook. F.

OBJECTIVE: To investigate the possible bone changes in female patients with systemic lupus erythematosus (SLE) induced by long-term administration of Tripterygium Wilfordii Hook. F (TW). METHODS: 70 female SLE patients were divided into 4 groups according to their drug history: SLE disease control group, corticosteroids treatment group, TW treatment group, and both corticosteroids and TW treatment group. Bone mineral density (BMD) of the lumbar spine 2-4 and biochemical markers of bone turnover were studied. RESULTS: Long-term administration of TW could significantly decrease BMD levels in female SLE patients (P < 0.05). The patients receiving TW for more than 5 years had significantly lower BMD levels compared with those for less than 5 years. The degree of decreased BMD induced by TW was less severe compared with that of prednisone. No significant differences were observed in the biochemical markers of bone turnover among four groups (P > 0.05). CONCLUSION: Long-term administration of TW could decrease BMD levels in women. Osteoporosis may be an important problem for SLE patients treated with TW.

Adult↗

The effects of glucose, insulin and oxidized low density lipoprotein on apoptosis in vascular endothelial cells.

OBJECTIVE: To study the effects of high concentrations of glucose, insulin and oxidized low density lipoprotein (ox-LDL) on apoptosis in cultured bovine aortic endothelial cells (ECs). METHODS: For qualitative determination of EC apoptosis, acridine orange (AO)/ethidium bromide (EB) staining and DNA agarose gels electrophoresis were used. Cellular DNA fragmentation ELISA measured apoptosis by quantitating the fragmentation of 5-bromo-2'-deoxyuridine-labeled DNA. RESULTS: High concentrations of glucose (20 mmol/L, 40 mmol/L), insulin (3000 microU/ml) and ox-LDL (50 micrograms/ml, 100 micrograms/ml) induced concentration- and time-dependent apoptosis in ECs. They had a synergetic effect on EC apoptosis. The combined effect of high concentration of glucose, insulin and ox-LDL was greater than any two of them; the effect of two was greater than one alone. Low concentration of insulin (30 microU/ml) decreased apoptosis in ECs induced by high concentrations of glucose (40 mmol/L), but no similar effect occurred with ox-LDL (100 micrograms/ml). CONCLUSION: High ambient glucose, insulin and ox-LDL can induce excessive apoptosis in cultured ECs, and low ambient insulin can prevent EC apoptosis. Excessive EC apoptosis induced by the separate or synergetic effect of hyperglycemia, hyperinsulinemia and hyperlipidemia may be one of the reasons for loss of endothelial integrity, dysfunction of the vascular endothelium and increased plasma membrane permeability, which are all involved in the development of diabetic macrovascular complications.

Animals↗

Relationship between serum or tissue ouabain and blood pressure in 1k1c hypertensive rats.

OBJECTIVE: To evaluate the role of endogenous ouabain (EO) in the development of hypertension and the characteristics of EO secretion in 1k1c (one kidney, one clipped) hypertensive rats. METHODS: EO content of serum and tissues in 1k1c hypertensive rats and normal control Sprague-Dawley (SD) rats was detected by the method of enzyme linked immunosorbent assay (ELISA). The relationship between serum or tissue ouabain and blood pressure was analyzed in 1k1c hypertensive rats. RESULTS: The ouabain content of serum, heart, kidney, adrenal gland, pituitary and hypothalamus was significantly higher in 1k1c hypertensive rats than that in normal control SD rats (2.25, 2.63, 3.35, 40.37, 3.34, 15.7 micrograms/kg tissue in 1k1c hypertensive rats vs 1.12, 1.79, 1.73, 27.54, 1.83, 10.10 micrograms/kg tissue in control SD rats, respectively. P < 0.05 for all of these comparisons). The ouabain content of the adrenal gland and the hypothalamus was higher than that of other tissues or serum, both in 1k1c rats and in control SD rats. The EO content of serum, kidney and hypothalamus was significantly correlated with blood pressure in 1k1c hypertensive rats (r = 0.59, 0.63, 0.52, respectively. P < 0.05). The ouabain content of heart, liver, adrenal gland and pituitary was not correlated with blood pressure. CONCLUSIONS: EO might play an important role in the development of hypertension in 1k1c hypertensive rats. The adrenal gland may be a major source of EO and the hypothalamus-pituitary-adrenal axis may be involved in the regulation of EO secretion.

Animals↗

Basic and clinical study on the antithrombotic mechanism of glycosaminoglycan extracted from sea cucumber.

OBJECTIVE: To investigate the antithrombotic mechanism of glycosaminoglycan (GAG) extracted from sea cucumber. METHODS: We studied the effects of GAG on the coagulant pathway by measuring cloting time. The antithrombin mechanism of GAG was checked by assaying its effects on the thrombin activity in normal human pooled plasma, purified human heparin cofactor II system and antithrombin III system. The effects of GAG on the assembly, dispersion, and structure of fibrin gels as well as on the activity of plasmin were studied by means of turbidimetry, electron microscopy, and chromogenic substrate assay. We studied the effect of GAG on the expression and transcription of tissue factor (TF) and thrombomodulin (TM) in LPS (lipopolysaccharide)-stimulated human umbilical vein endothelial cells (HUVECs), and used heparin as a control. HUVECs were treated with different concentrations of GAG (1 microgram/ml, 5 micrograms/ml, and 10 micrograms/ml respectively) and 5 micrograms/ml heparin as a control together with LPS (1 microgram/ml). After incubation for 6 hours, TF and TM were investigated by ELISA and the mRNA study was carried out by RT-PCR. In a clinical trail, a series of variables were observed before and after treatment with GAG in patients recovering from cerebral ischemic stroke or suffering from ischemic heart disease. RESULTS: The TT and APTT were significantly prolonged by GAG (0.1 microgram/ml). GAG inhibited thrombin activity in the presence of HCII with a second order rate constant of 1.14 x 10(7) m-1.min-1, which was 4.6 times higher than that of ATIII. GAG significantly inhibited the polymerization of fibrin monomer and enhanced the activity of plasmin in a concentration dependent manner. GAG could impair TF mRNA expression and up-regulate TM mRNA expression. The result of clinical trail showed that the fat metabolism was enhanced in addition to the anticoagulant and the blood viscosity reducing effects. No side-effect was found. CONCLUSIONS: GAG mainly affected on the intrinsic pathway of blood coagulation. GAG was similar to dermatan sulfate both in the efficiency and in the mechanism of antithrombin. The acceleration of colt lysis by GAG depended on its ability to increase the activity of plasmin, to inhibit the polymerizing of fibrin monomer, and consequently, to alter the architecture of the fibrin net work. This effect on HUVECs appears to be at a transcriptional level and might be relevant for the antithrombotic action of GAG. GAG possess anticoagulant activity in vivo and it is a promising drug for antithrombotic therapy.

Animals↗

Oral administration of insulin to female nonobese diabetic mice inhibited diabetes and induced Fas ligand expression on islets of Langerhans.

OBJECTIVE: To detect oral administration of recombinant human insulin to nonobese diabetic (NOD) mice for preventing them from diabetes and insulitis and to detect the effects of oral administration of insulin on Fas and Fas ligand expression on islet of Langerhans. METHODS: Sixty-four female NOD mice were divided into two groups. One group (34) was orally administered recombination human insulin 1 mg in 500 microliters PBS and the other (30) 500 microliters PBS only at age of 5 weeks old, twice a week for the first week, then weekly until 30 weeks of age. RESULTS: Oral administration of insulin to female NOD mice can significantly suppress diabetes and insulitis. The insulitis was less severe in the group fed with insulin than that in the control group (score of insulitis: 1.25 +/- 0.45 vs 3.0 +/- 0.76 at 16 weeks of age, P < 0.01). We examined Fas ligand and Fas expression on islets of Langerhans in both groups of NOD mice by using immunohistochemical techniques. We find that Fas only expressed on islets when the mice suffered the diabetes, whereas Fas ligand expressed on islets of the mice fed with insulin at 16 and 20 week of ages. We did not find Fas ligand positive staining on the islet feeding with PBS. CONCLUSION: We speculated that oral insulin may induce Fas ligand expression on the islets and plays a role in protecting the pancreatic beta-cell from autoimmune destruction. These results show that oral insulin affected autoimmune diabetes and insulitis in NOD mice. The immune mechanism of oral tolerance is closely related to the change of Fas ligand and Fas system.

Administration, Oral↗

[The xenoantigenicity of Chinese inbred-line pigs].

OBJECTIVE: The major obstacle in pig to human transplantation is acute and hyperacute rejection (HAR) triggered mainly by alpha-galactosyl residues(alpha-Gal) in donor. Since the inbred-line Banna pig(IBNP) and Wuzhishan pig (IWZSP) are highly inbred and may be the potential donor for xenotransplantation, it is important to investigate the reaction between human serum and inbred-line pig tissues as well as the distribution of alpha-Gal in these tissues. METHODS: Samples from heart, liver, spleen, lung, kidney, pancreas, small intestine, thymus, skin, lymph node and blood vessels at all levels were collected from four 8 to 11-month-old male IBNPs and one IWZSP. Affinity-immunohistochemistry assays were conducted following routine procedures on paraffin sections with normal human sera of blood type A, B, O, AB and BSI-B4(alpha-Gal specific binding lectin) as the primary antibodies or affinity reagents. Sections digested by alpha-galactosidase were also examined as control. RESULTS: Parallel results were obtained from these pig tissues stained against human sera and BSI-B4. There was no significant difference both in the antigens recognized by sera of different blood types or BSI-B4 and in the distribution of alpha-Gal. The strongest alpha-Gal positive staining was appeared in vascular endothelial cells at all levels and partial parenchyma cells. However, tissues of cartilage, peripheral nerve and muscle were negative. After digested by alpha-Galactosidase, all samples were negative against BSI-B4 and human sera except few positions that showed different staining. CONCLUSION: The distribution of target antigen is similar in various tissues of the two kinds of pigs. Though alpha-Gal is the major xenoantigen in IBNP and IWZSP, there may be some unknown antigens related to pig to human transplantation. Possibly the level and distribution of antigen expression in pig tissues are not the first affair to be considered, and these pigs should be genetically modified in order to eliminate rejection in pig to human xenotransplantation.

Animals↗

[Double semitendinous reconstruction of posterior cruciate ligament with invasive mini-plate technique].

OBJECTIVE: To probe the clinical results of a new designed operation-double semitendinous reconstruction of posterior cruciate ligament (PCL) with invasive mini-plate. METHODS: The new surgical technique was performed on 28 patients with PCL deficient knee in our department from September 1994 to October 1997. Protection of popliteal nerves and blood vessels was emphasized in the operation, and the femoral and tibial tunnel placement was critical to the procedure's success. RESULTS: All patients were followed up 18 to 36 months, averaged 22 months, they gained stable knees. The knee function of 28 patients recovered to normal after the operation, 1 patients had a small range of limitation of the knee flexion, but no obvious dysfunction. CONCLUSION: Double semitendinous reconstruction of PCL with invasive mini-plate has advantages in the operated field exposure, adequate tibial and femoral fixation and excellent results in motion, stability and function of the knee after the operation.

Adolescent↗

[Detection of DNA extracted from Mycobacterium tuberculosis by TaqMan-PCR technique and its clinical application].

OBJECTIVE: To evaluate the clinical diagnostic value of TaqMan-PCR technique in the diagnosis of active pulmonary tuberculosis. METHODS: The specimens of sputum and peripheral blood from 168 patients with active pulmonary tuberculosis, 57 patients with lung cancer and the specimens of peripheral blood from 34 healthy individuals were detected by TaqMan-PCR, PCR. The specimens of sputum were also detected by smear, culture with BACTEC and Lowenstein-Jensen for comparison. RESULTS: The positive rates of sputum and peripheral blood detected by TaqMan-PCR were 53.0% and 61.3%, respectively, significantly higher than those of PCR, smear, culture with BACTEC and Lowenstein-Jensen (P < 0.05). There was no significant difference between TaqMan-PCR and PCR for specificity (P > 0.05). Of 105 specimens of peripheral blood from patients with smear-negative and culture-negative pulmonary tuberculosis, 48 specimens of peripheral blood detected by TaqMan-PCR were positive. The positive rate was 45.7%. CONCLUSIONS: TaqMan-PCR method showed higher sensitivity and specificity. It is an useful tool for diagnosis of pulmonary tuberculosis, particularly smear-negative and culture-negative pulmonary tuberculosis.

DNA, Bacterial↗

[Study on respiratory impedance of patients with extratracheal tumour].

OBJECTIVE: To determine the manifestation of impulse oscillometry (IOS) in variation of respiration impedance on patients with extratracheal tumour. METHODS: The IOS indices in 30 normal persons and 28 patients with extracheal tumour were measured. The ratio of forced expiratory volume after 1 second to forced vital capacity (FEV1/FVC) was evaluated and the maximal expiratory flow-volume curve (MEFV curve) was examined. The above values with t-test of SPSS statistics software were analyzed. RESULTS: Compared with the normal group, in the extratracheal group the ratio of actual value of resistance to the predict from 20 Hz to 35 Hz increased obviously and this only occurred with the reactance at 20 Hz (P < 0.01). The resistance curve showed clear rise after the 20 Hz and the reactance curve peaked at 20 Hz and was leveled to normal at 35 Hz. CONCLUSION: IOS is capable of presenting the distinctive indices for the study of respiration impedance on patients with extratracheal tumour.

Electric Impedance↗

[Histopathological study of temporomandibular joint in early stage of polyarthritis rats].

OBJECTIVE: To furnish an experimental basis of the early effects of rheumatoid arthritis (RA) on the temporomandibular joint (TMJ) by observing the histopathological changes of TMJ in the early stage of polyarthritis (PA) rats. METHODS: The animal model of PA was established by injecting Freund's complete adjuvant (FCA) into rats. The histopathological changes of the rats' ankle joint and TMJ were studied. RESULTS: (1) The paw volume and the articular index of PA rats increased significantly, and symptoms of pronounced inflammation were present in the ankle joint specimens, which included proliferation of the synovium, infiltration with inflammatory cells, erosion into the articular cartilage and bone, and inflammatory exudation into the articular cavities. (2) The histopathology of TMJ of PA rats showed pronounced proliferation of the synovium cells, some lytic collagenous fibers and degenerative chondrocytes in the condyles, and exudated protein and desquamating cells in the articular cavities with some fibrinous adhesions. CONCLUSION: Pronounced inflammation occurs in bilateral TMJ in early stage of PA rats. The examination, protection and treatment of TMJ for RA patients should be taken into account in the early stage.

Animals↗