PubMed Health⌕ Search

Biomedical subjects

Zhen Yang

Publications and source records attributed to Zhen Yang.

At least 37 records · Page 2Linked to original sources
PubMed2006

Pathogenesis of osteopenia/osteoporosis induced by highly active anti-retroviral therapy for AIDS.

The advent of highly active anti-retroviral therapy (HAART) has dramatically decreased the rate of AIDS-related mortality and significantly extended the life span of patients with AIDS. A variety of metabolic side effects are associated with these therapies, one of which is metabolic bone disease. A higher prevalence of osteopenia and osteoporosis in HIV-infected patients receiving anti-retroviral therapy than in patients not on therapy has now been reported in several studies. Several factors have been demonstrated to influence HIV-associated decreases in bone mineral density (BMD), including administration of nucleoside reverse transcriptase inhibitors (NRTIs). In this article, discussion will focus on the molecular pathogenesis and treatment of HAART-associated osteopenia and osteoporosis.

Acquired Immunodeficiency Syndrome↗
PubMed2006

[Suppression of SMYD3 expression in HepG2 cell by shRNA interference].

OBJECTIVES: To identify the inhibition effect of shRNA on the SMYD3 (SET- and MYND-domain containing protein-3) expression in hepatoma cell line HepG2 through gene silencing. METHODS: Two reverse repeated motifs targeting on the SMYD3 mRNA sequences 267-288, 302-323 respectively, were synthesized and inserted into the mock plasmid pGenesil-1 which expressed EGFP to create recombinant plasmids pGenesil-1-s1 and pGenesil-1-s2. pGenesil-1-hk specific to no SMYD3 mRNA sequence served as a control. After transfection into HepG2 cells, RT-PCR and western blot were applied to identify the down regulation of SMYD3 expression by shRNAs. RESULTS: All plasmids were constructed successfully. pGenesil-1-s1, pGenesil-1-s2 inhibited the mRNA and protein expression of SMYD3 in HepG2 cells. There was a significant distinction when compared with pGenesil-1-hk and pGenesil-1 (P<0.01). CONCLUSION: Short hairpin RNAs can efficiently and specifically suppress the expression of SMYD3 in HepG2 cells.

Carcinoma, Hepatocellular↗
PubMed2006

[Intralesional injection of Pingyangmycin for treatment of venous-venular malformation in the maxillofacial regions of children: report of 306 cases].

PURPOSE: To evaluate the effect of intralesional injection of Pingyangmycin (PYM) for treatment of venous-venular malformation in the maxillofacial regions of children. METHODS: The medical records of 306 patients with venous-venular malformation in the maxillofacial regions between January 1997 and June 2005 were reviewed. One hundred and twenty-three of the patients were men, and one hundred and eighty-three were woman, the sex ratio was 1:1.49. The patients aged from one month to 12 years, 172 were less than 6 months (56.21%). Pingyangmycin was injected into the center or in the vicinity of the venous-venular malformations, and repeated every 7 to 10 days. This cycle were repeated 3 to 5 times when necessary. RESULTS: Three hundred and six patients were followed up for 6 to 102 months. Complete response was obtained in 156 cases (50.98%), partial response in 116 cases (37.91%), and improvement in 34 cases (11.11%). The overall response rate was 100%, and the curative rate was 88.89%. CONCLUSION: This method is safe, simple and effective for venous-venular malformation in the maxillofacial regions of children.

Antibiotics, Antineoplastic↗
PubMed2006

[Inhibition of SMYD3 gene expression by RNA interference induces apoptosis in human hepatocellular carcinoma cell line HepG2].

BACKGROUND & OBJECTIVE: SET and MYND domain-containing protein 3 (SMYD3) gene was found to encode a histone methyltransferase involved in the proliferation and apoptosis of cancer cells. This study was to detect the expression of SMYD3 in hepatocellular carcinoma (HCC) cell lines, and reveal its function of regulating proliferation and apoptosis of HCC cell line through gene silencing. METHODS: The expression of SMYD3 in HCC cell lines HepG2, Hep3B, SMMC7721, and normal hepatic cell line L-02 was detected by reverse transcription-polymerase chain reaction (RT-PCR); its expression in 24 specimens of HCC and peri-cancer tissue was detected by immunohistochemistry. Short hairpin RNA (shRNA) plasmids Pgenesil-1-s1 and Pgenesil-1-s2 (with interfering effect), and Pgenesil-1-hk (without interfering effect) were constructed and transfected into HepG2 cells. Western blot was used to detect the expression of SMYD3 protein after transfection. Cell proliferation was analyzed by MTT assay; cell apoptosis was analyzed by flow cytometry (FCM) and TUNEL. RESULTS: SMYD3 was overexpressed in the HCC cell lines and HCC tissue. After transfection with shRNA, SMYD3 expression in HepG2 cells was down-regulated by 75%-85%, and the cell growth was inhibited by 60.95%-72.14%. The apoptosis rate of HepG2 cells was significantly higher in Pgenesil-1-s1 and Pgenesil-1-s2 groups than in Pgenesil-1-hk and Pgenesil-1 groups [(17.68+/-2.36)% and (19.07+/-1.78)%, vs. (1.44+/-0.28)% and (0.47+/-0.12)%, P<0.01]. CONCLUSION: SMYD3 is overexpressed in various HCC cell lines and HCC tissue; RNA interference can down-regulate SMYD3 expression, inhibit proliferation and promote apoptosis of HepG2 cells.

Apoptosis↗
PubMed2006

Down-regulation of the gax gene in smooth muscle cells of the splenic vein of portal hypertension patients.

BACKGROUND: The expression of gax, an anti-proliferative homeobox gene, is rapidly down-regulated in vascular smooth muscle cells (VSMCs) following arterial injury. Whether the down-regulation of gax is involved in modulating the proliferation of smooth muscle cells of the splenic vein in patients with portal hypertension has not yet been elucidated. The aim of this study was to investigate the expression of the mRNA of the gax gene in smooth muscle cells of the splenic vein in patients with portal hypertension. METHODS: Reverse transcriptase polymerase chain reaction (RT-PCR) was used to detect the expression of gax mRNA and immunohistochemistry staining was performed to demonstrate the expression of PCNA protein in the splenic veins of 28 patients with portal hypertension and those of 12 normal controls. This study was approved by the Institutional Ethics Committee and informed consent was obtained from all participants. RESULTS: RT-PCR showed that the expression of gax mRNA was PCNA-positive and negative in the splenic vein of patients with portal hypertension (1.08+/-0.04 and 1.39+/-0.27, respectively). There was a significant difference in the 28 patients compared with the 12 normal controls (P<0.01). The relative expression of PCNA protein in the vascular tissues was significantly higher in the experimental group than in the control group. CONCLUSIONS: Down-regulation of gax mRNA and the overexpression of PCNA protein were seen in smooth muscle cells of the splenic vein in patients with portal hypertension, regulating the proliferation, migration and phenotypic change and resulting in remodelling of the splenic vein, which may play an important role in the pathogenesis and maintenance of portal hypertension.

Adult↗
PubMed2006

[Prevalence and clinical characteristics of the A to G variant at position 12026 of the mitochondrial ND4 gene in familial diabetes mellitus in Chinese population].

OBJECTIVE: To assess the prevalence of the A to G variant at nucleotide 12026 (mt12026) of the mitochondrial NADH-dehydrogenase subunit 4 (ND4) gene in familial diabetes mellitus in Chinese population. METHODS: The authors screened 770 randomly selected, unrelated probands of diabetic pedigrees, and 309 controls with normal glucose tolerance for the variant by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique and PCR-direct-sequencing. RESULTS: The mt12026 A --> G variant was detected in 28 diabetic patients (3.63%) and 9 controls (2.91%). The frequency of the variant mt12026 A --> G was not statistically different between diabetic patients and controls. Moreover, clinical characteristics such as age, body mass index (BMI), and insulin resistant index were not different between diabetic patients with and without the mt12026 mutation. CONCLUSION: The mt12026 A --> G variant is a mitochondrial gene polymorphism in Chinese population, and it is unlikely that the mutation is in itself the cause of diabetes.

Asian People↗
PubMed2005

Enhanced external counterpulsation improves endothelium-dependent vasorelaxation in the carotid arteries of hypercholesterolemic pigs.

BACKGROUND: Enhanced external counterpulsation (EECP) has been demonstrated to be an effective method for the treatment of atherosclerotic vascular disease. However, the exact mechanism underlying the beneficial effects of EECP is not completely clear. We hypothesized that EECP leads to improvement in endothelial function, contributing to its clinical benefits. METHODS: Fifteen male domestic pigs were initially divided into 2 dietary groups: one consumed a normal feeding (NF) of pig chow (n=5), and one consumed a high-fat (HF) pig chow (n=10). After 8 weeks on the NF or HF diet, 5 HF pigs received EECP treatment (HF+EECP) 1 h daily for 6 weeks and the remaining 5 HF pigs continued to be fed by high cholesterol diet. At the end of 6-week EECP treatment, the carotid arterial rings from all of the pigs were harvested. Endothelium-dependent and -independent vasorelaxation to acetylcholine (ACh) and sodium nitroprusside (SNP) were measured in a dose-dependent manner. RESULTS: The high fat diet resulted in increase in plasma cholesterol and triglyceride levels (p<0.05). Endothelium-dependent vasorelaxation was decreased in the HF group compared to the NF control (p<0.05). However, EECP treatment partially improved impaired endothelium-dependent vasorelaxation in the HF+EECP group compared to the HF control (p<0.05). Endothelium-independent vasorelaxation was not significantly different among the three groups. CONCLUSIONS: Endothelium-dependent vasorelaxation is impaired in the hypercholesterolemic pigs. EECP treatment significantly improves hypercholesterolemia-induced diminished endothelium-dependent vasorelaxation. It suggests that amelioration in endothelial function may at least in part contribute to the beneficial effects of EECP treatment in clinical practice.

Acetylcholine↗
PubMed2005

Research progress of vasculopathy in portal hypertension.

Portal hypertension, one of the vascular diseases, not only has lesions in liver, but also changes in vascular structures and functions of extrahepatic portal system, systemic system and pulmonary circulation. The pathological changes of vasculopathy in portal hypertension include remodeling of arterialized visceral veins, intimal injury of visceral veins and destruction of contractile structure in visceral arterial wall. The mechanisms of vasculopathy in portal hypertension may be attributed to the changes of hemodynamics in portal system, immune response, gene modulation, vasoactive substances, and intrahepatic blood flow resistance. Portal hypertension can cause visceral hyperdynamic circulation, and the development and progression of visceral vasculopathy, while visceral vasculopathy can promote the development and progression of portal hypertension and visceral hyperdynamic circulation in turn. The aforementioned three factors interact in the pathogenesis of hepatic cirrhosis-induced portal hypertension and are involved in hemorrhage due to varicose vein rupture.

Animals↗
PubMed2005

[Expression of local angiotensinogen mRNA and activation of local nuclear factor-kappaB in vasculopathy of portal hypertension].

OBJECTIVE: To investigate the expression of local angiotensinogen mRNA and activation of local nuclear factor-kappaB in vasculopathy of portal hypertension and to discuss their role in the pathogenesis of portal hypertensive vasculopathy. METHODS: RT-PCR was used to detect the expression of local angiotensinogen mRNA in 28 specimens of splenic artery and vein obtained during operation of elective separation and amputation on 28 portal hypertension (PH) patients, 20 males and 8 females, aged 51.7 +/- 10 (30 - 65), and in 12 specimens of normal vessel from 12 patients undergoing splenectomy due to traumatic rupture of spleen. Chemiluminescent electrophoretic mobility shift assay (EMSA) was used to detect the activation of NF-kappaB in splenic artery and vein. RESULTS: The levels of local angiotensinogen mRNA in the splenic artery and vein of PH group were 0.48 +/- 0.21 and 0.43 +/- 0.16 respectively, both significantly higher than those in the control group (0.23 +/- 0.12 and 0.18 +/- 0.10, both P < 0.05). There was no significant difference between the splenic artery and vein in the expression of local angiotensinogen mRNA in PH group. The activation levels of NF-kappaB in splenic artery and vein of the PH patients were 1.44 +/- 0.23 and 1.38 +/- 0.18 respectively, both significantly higher than those of the control group (0.19 +/- 0.20 and 0.25 +/- 0.16 respectively, both P < 0.05). However, there was no significant difference in the activation levels of NF-kappaB between the splenic artery and vein in the PH patients (P > 0.05). CONCLUSION: Local angiotensinogen and activation of NF-kappaB maybe one of the factors in the pathogenesis of portal hypertensive vasculopathy, which can cause and advance portal hypertensive vasculopathy.

Adult↗
PubMed2005

Exploring an expedient IMDA reaction approach to construct the guanacastepene core.

Construction of the [5-7-6] tricyclic core of guanacastepenes was attempted by using the intramolecular Diels-Alder (IMDA) reaction and Me(3)Al-mediated ring opening of the oxabridge as key synthetic steps. The illustrated chemistry demonstrated a synthetic feasibility to build up the framework of guanacastepenes by the IMDA reaction. [reaction: see text]

Catalysis↗
PubMed2005

Nucleolar localization of non-structural protein 3b, a protein specifically encoded by the severe acute respiratory syndrome coronavirus.

The open reading frame 3 (ORF3) of the severe acute respiratory syndrome coronavirus (SARS-CoV) genome encodes a predicted 154-amino acid protein, which lacks similarities to any known protein, and is named 3b. In this study, it was shown that 3b protein was predominately localized to nucleus with EGFP tag at its N- or C-terminus. The localization patterns were similar in different transfected cells. Immuno-fluorescence assay revealed that 3b protein was co-localized well with C23 in nucleolus. C23, B23 and fibrillarin all are important nucleolar proteins, which localize in the region of the nucleolus. Co-transfection of p3b-EGFP with pC23-DsRed, pB23-DsRed and pfibrillarin-DsRed further confirmed 3b's nucleolus localization. With construction of serial truncated mutants of 3b, a region (residues 134-154 aa) responsible for nucleolar localization was determinated in 3b protein. These results provide a new insight for further functional studies of SARS-CoV 3b protein.

Amino Acid Sequence↗
PubMed2005

Pd-catalyzed copper-free carbonylative Sonogashira reaction of aryl iodides with alkynes for the synthesis of alkynyl ketones and flavones by using water as a solvent.

The Pd-catalyzed copper-free carbonylative Sonogashira coupling reaction to synthesize alkynyl ketones from terminal alkynes and aryl iodides was achieved by using water as a solvent. The reaction was carried out at room temperature under balloon pressure of CO with Et(3)N as a base. The developed method was successfully applied to the synthesis of flavones.

Alkynes↗
PubMed2005

[The experimental study on pathological changes of pulmonary tissues in portal hypertensive rabbits with schistosomal cirrhosis].

OBJECTIVE: To investigate the pathologic features of the pulmonary tissue in portal hypertensive rabbits with schistosomal cirrhosis, and to study the role of endothelin-1 (ET-1) and nitric oxide (NO) in pathogenesis of portal hypertensive pulmonary vasculopathy. METHODS: The experimental group included 10 rabbits infected percutaneously with cercariae of Schistosomiasis Japonica. The control group included 10 normal rabbits. HE stain, Masson trichrome stain and transmission electron microscopy were applied to detect the pathologic features of the pulmonary tissue. The expression and distribution of endothelin-1 (ET-1) and nitric oxide synthase (NOS) in the lung tissues were analyzed by immunohistochemistry. RESULTS: After 120 d, the pathological morphology alteration of the pulmonary tissue was observed in the rabbits in experimental group. Both of ET-1 and NOS-containing cells were more abundant in distribution and expression in the lung tissue of experimental group than those of the control group. There was significant difference between the two groups in the parameter of area, lightness and gray level of ET-1 and NOS (P < 0.01). CONCLUSIONS: Pulmonary pathologic changes occur in the portal hypertensive rabbits with schistosomal cirrhosis. ET-1 and NOS-containing cells are more abundant in pulmonary vessel of portal hypertension, then followed by dilation of intrapulmonary vessel. It is deduced that ET-1 and NO might play an important role in the pathogenesis of portal hypertensive pulmonary vasculopathy.

Animals↗
PubMed2005

A highly efficient synthesis of the FGH ring of micrandilactone A. Application of thioureas as ligands in the Co-catalyzed Pauson-Khand reaction and Pd-catalyzed carbonylative annulation.

The functionalized FGH ring system of micrandilactone A was successfully constructed in high selectivity and good yields. The key reactions in our strategy are the Co-thiourea-catalyzed stereoselective, intramolecular Pauson-Khand reaction and Pd-thiourea-catalyzed stereoselective, intramolecular annulation. [structure: see text]

Catalysis↗