Biomedical subjects

Lin Wang

Publications and source records attributed to Lin Wang.

304 records · Page 17Linked to original sources

PubMed2002

[Imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis].

OBJECTIVE: To explore if there is an imbalance of Th1/Th2 cytokines in patients with pulmonary tuberculosis and its correlation with disease severity and treatment results. METHODS: The levels of serum IgE, IL-4 and IFN-gamma were measured in 100 healthy controls and 124 patients with pulmonary tuberculosis who were sputum positive for Mycobacterium tuberculosis before treatment. The cytokine levels were compared and their correlation with disease severity, sputum conversion after treatment, and treatment protocols were analyzed. RESULTS: The serum levels of IgE, IL-4 and IFN-gamma were 1.048 +/- 0.496, 0.439 +/- 0.160 and 0.213 +/- 0.017 respectively in pulmonary tuberculosis, and 0.867 +/- 0.289, 0.421 +/- 0.024 and 0.224 +/- 0.005 respectively in the controls. The serum level of IL-4 was higher in patients with severe disease than that in patients with milder disease. Both IL-4 and IFN-gamma were significantly higher in cases receiving a second course of therapy than in patients receiving initial therapy. In patients who were sputum positive for Mycobacterium tuberculosis after two months of therapy, the serum level of IL-4 was higher but that of IFN-gamma was lower compared to those who became sputum negative for Mycobacterium tuberculosis after two months' treatment. CONCLUSIONS: Patients with active pulmonary tuberculosis before antituberculous therapy showed lower expression of Th1 and higher expression of Th2 cytokines, and this cytokine profile was correlated with disease severity. Patients with lower serum IFN-gamma and higher IL-4 before treatment were less responsive to antituberculous therapy.

Adult↗

PubMed2002

[Simultaneous intraocular lens implantation during vitreous surgery for treatment of proliferative diabetic retinopathy].

OBJECTIVE: To evaluate the efficacy of cataract extraction and simultaneous intraocular lens (IOL) implantation during vitreous surgery for treatment of a series of patients with proliferative diabetic retinopathy (PDR) and cataract. METHODS: A consecutive series of PDR treated with vitrectomy and simultaneous IOL implantation during February 1997 and October 2001 was retrospectively analyzed. RESULTS: The series included 37 cases (12 males and 25 females) 44 eyes (OD 13; OS 17 and OU 7) with diabetic history for 1 - 30 years and eye symptoms for 40 days to 10 years. Surgical techniques included lensectomy or phacofragmentation via the pars plana. The anterior capsule was preserved and the epithelium was suctioned and scraped off. After vitreous surgery and endolaser, IOL was inserted via the corneoscleral incision on the anterior capsule, of which the center area 5 mm in diameter was cut. The patients was followed-up for 3 months to 4.5 years, mean (16 +/- 13) months. Visual acuity was light perception, hand motion, finger count, 0.02, and 0.1 - 0.2 in 5, 14, 11, 6, and 8 (18.2%) eyes, respectively before operation. Postoperatively, visual improvement was achieved in 41 eyes with 0.1 - 1.0 in 35 eyes (79.5%). Visual acuity remained unchanged in 2 eyes and decreased in one eye. Eyes with lower vision were associated with marked macular edema, hard exudates and severe ischemia. Six eyes had mild corneal edema 2 approximately 5 days after operation. Corneal ulcer or neovascular glaucoma occurred in 2 eyes 5 months after surgery. CONCLUSION: Cataract extraction and simultaneous IOL implantation during vitreous surgery for PDR may improve the visual outcome in the majority of selected eyes without significant complications.

Adult↗

PubMed2002

[Clinical analysis of laparoscopic pelvic and paraaortic lymphadenectomy treated patients with gynecological malignancies].

OBJECTIVE: To investigate the possibility and value of laparoscopic radial hysterectomy with lymphadenectomy in patients with gynecology malignancies. METHODS: From July 2000 through June 2002, we performed laparoscopic radial hysterectomy with lymphadenectomy on 56 patients with biopsy-proven endometrial or cervical carcinoma (21 endometrial cancer and 35 cervical cancers). Pelvic, para-aortic, and combinations of both pelvic and para-aortic lymphadenectomies were performed depending on the primary site of the disease and indication for lymph node dissection. RESULTS: Laparoscopic procedure required an average of 3.1 h, with an average blood loss of 198 ml. The average number of nodes was 16. Patients undergoing laparoscopic assisted vaginal radical hysterectomy and lymphadenectomy alone were admitted for 9.6 days on average. There were 5 patients with intraoperative complications. Two patients were bladder injury and other two patients with venous injury. One patient was colon injury and converted to an abdominal procedure. There were no ureteral or intestinal injuries. Postoperative complications occurred in 3% of patients and only one was considered ureteral constriction 1 month after operation. There has been one patient with trocar site recurrences 4 weeks after operation. Three patients have retention of urine. CONCLUSIONS: Laparoscopic assisted vaginal radical hysterectomy and lymphadenectomy was feasible and safe for treatment of cervical or endometrial cancer. Also it was a less invasive, and recovery time was reduced. This was reliable and accurate method for evaluating lymph node metastasis of cervical or endometrial carcinoma.

Adult↗

PubMed2002

[Epidemiological survey on bronchial asthma in Liaoning province].

OBJECTIVE: To survey the prevalence of asthma in urban and rural residents of Liaoning province in 1999 and evaluate the risk factors for asthma, providing data for research and preventive and therapeutic policies for control of asthma. METHODS: Stratified cluster disproportional random sampling survey was performed in 116 276 residents by common protocols and questionnaire. Asthma was diagnosed based upon case history, clinical signs and lung function tests. Univariate analysis was employed to evaluate the risk factors for asthma. RESULTS: The overall prevalence of asthma in Liaoning province was 1.25%, the male to female ratio being 1:1.64. The prevalence of asthma in adults was 1.39% and that in children was 0.48%. The onset of asthma occurring in children under the age of 14 accounted for 38.63% of the whole patients. The prevalence was higher in peasants, animal breeders and government officials. The prevalence in the rural area (1.89%) was higher than that in the urban area (0.81%) (P < 0.01). The prevalence in Shenyang city (1.66%) was higher than those in Dalian city (0.88%) (P < 0.01) and Jinzhou (0.71%) (P < 0.01) city. Risk factor analysis showed that 24.7% of the asthmatics had family history; 20.4% had allergic history, the OR of allergic rhinitis being 6.28; 26.0% had smoking history; the OR of cooking oil smoke exposure was 5.94. Asthmatic attack was induced by influenza, cold air, irritant gases and cooking oil smoke in 52.3% approximately 63.3% of the patients. Asthma induced by exercising, fatigue, emotion and allergy was found in more than 41.3% of the patients. CONCLUSIONS: Our epidemiologic data reflected the general distribution of asthma in Liaoning province. From the overall prevalence rate, it is estimated that there are about 529 700 asthmatics in the whole province. The data will be helpful for the mass prevention and treatment of asthma.

Adolescent↗

PubMed2002

Chemiluminescence flow-through sensor for the determination of vitamin B2 using controlled-reagent-release technology.

AIM: To establish a simple and novel method for the determination of vitamin B2 rapidly in pharmaceutical preparations. METHODS: Vitamin B2 was determined by a chemiluminescence (CL) sensor combined with flow-injection (FI) technology. The analytical reagents involved in the CL reaction, luminol and hexacyanoferrate (III), were both immobilized on an anion-exchange resin column in FI system. The CL signal produced by the reaction between luminol and hexacyanoferrate (III), which were eluted from the column through sodium phosphate injection, decreased in the presence of vitamin B2. RESULTS: The decreased CL intensity was linearly correlated with the vitamin B2 concentration in the range of 0.01-1.0 microgram.mL-1, the detection limit was 4.0 ng.mL-1 vitamin B2 (3 sigma). At a flow rate of 2.0 mL.min-1, the procedure including sampling and washing could be performed in 2 min with a relative standard deviation of less than 3.0%. CONCLUSION: The flow sensor exhibited both good sensitivity and stability. It could be reused more than 450 times and has been applied successfully to the analysis of vitamin B2 in pharmaceutical preparations.

Flow Injection Analysis↗

PubMed2002

[Studies on the inhibition of polyhydroxylated aromatic compounds against HIV-1 integrase].

AIM: Three major enzymes of HIV-1, reverse transcriptase (RT), protease (PR), and integrase (IN), are important targets for anti-HIV drugs. Nine RT and five PR inhibitors have been effectively used in treatment of AIDS patients. In order to find active integrase inhibitors, twenty polyhydroxylated aromatic compounds were tested. METHODS: ELISA method was used to test the integrase activity. The synthesized donor substrate oligonucleotide representing the HIV-1 U5LTR was immobilized onto Covalink polystyrene microtiter plates, and a synthesized biotinlated 20 bp oligonucleotide was used as the target substrate. The products were detected and quantified by a colorimetric avidin-linked alkaline phosphatase reporter system. RESULTS: Compound NQ-2 was found to inhibit HIV-1 integrase with the IC50 of 78.5 mumol.L-1 by ELISA method. Its novel analogue NQ-3 was found to be 2 fold more potent on HIV intrgrase than NQ-2, IC50 was 37.2 mumol.L-1. The IC50s of NQ-2 and NQ-3 to inhibit the 3'-pro + assembly activity of integrase were 96.94 mumol.L-1 and 8.48 mumol.L-1; to inhibit assembly activity were 168 and 6.9 mumol.L-1 and to inhibit strand-transfer activity were 49.8 and 1.1 mumol.L-1, respectively. Compound NQ-2 mostly inhibited the strand transfer activity of HIV-1 integrase. Compound NQ-3 inhibited both the assembly and strand-transfer with high activities. CONCLUSION: Naphthoquinone compound NQ-3 was found to be a novel HIV integrase inhibitor which warrants further study. Uncoupled ELISA HIV integrase assay is shown to be useful to screen HIV-1 integrase inhibitors.

Coumarins↗

PubMed2002

Synthesis of 1-(3-phthalimido-2-oxobutyl)-4-substituted- phenylpiperazines and their anti-HIV reverse transcriptase activity.

AIM: Synthesis of 1-(3-phthalimido-2-oxobutyl)-4-substituted- phenylpiperazines (5-15). METHODS: The starting material nitrogen mustard hydrochloride (16), reacted with the corresponding substituted anilines to afford piperazine hydrochlorides (17-27), which were then coupled with 1-bromo-3-phthalimidobutan-2-one (4) to give the target compounds. RESULTS: Eleven target compounds (5-15) were synthesized, which were characterized by 1HNMR, IR and elemental analysis. CONCLUSION: Anti-HIV-1 RT using HIV reverse transcriptase P-66 protein test showed that compounds 11, 14, 10 and 13 possessed inhibitory effects against HIV-1 reverse transcriptase (RT), with IC50 29.80, 35.20, 43.77 and 63.76 mumol.L-1, respectively.

HIV Reverse Transcriptase↗

PubMed2002

[Study on effect of Salvia injection in treating primary nephrotic syndrome and on endothelin and serum interleukin-2 receptor in children].

OBJECTIVE: To explore the effect and mechanism of Salvia Injection (SI) in treating primary nephrotic syndrome (PNS) in children. METHODS: Forty-four PNS children were randomly divided into conventional steroid treated group (20 cases) and conventional plus SI intervention treated group (24 cases), the levels of serum endothelin (ET), soluable interleukin-2 receptor (sIL-2R) were observed. RESULTS: Before treatment, plasma ET and sIL-2R in PNS children were higher than those in healthy children significantly (P < 0.01). After treatment, the ET and sIL-2R levels were all obviously improved in both treated groups (P < 0.05) and the improvement in the conventional plus SI intervention treated group was more obvious, the difference between the two treated groups after treatment was significant (P < 0.05). CONCLUSION: Conventional treatment supplemented with SI could more effectively improve the levels of plasma ET and SIL-2R in treating PNS children, and hence alleviate the damage of renal tissue.

Adolescent↗

PubMed2002

[Screening and cloning gene of hepatocyte protein interacting with hepatitis C virus core protein].

OBJECTIVE: To clone the unknown gene of hepatocyte protein interacting with hepatitis C virus core protein. METHODS: Using the yeast dual hybrid system 3, bait plasmids of hepatitis C virus core were constructed. After identifying hepatitis C virus core protein that could stably expressed in AH109 yeast strains, we performed yeast two hybrid by mating AH109 with Y187 that transformed with liver cDNA library plasmids pACT2 and then plated on quadrople dropout (QDO) medium and assayed for alpha-gal activity. The genes of yeast colonies that could grow on QDO and had alpha-gal activity were sequenced. RESULTS: Among the 30 positive colonies, we blasted the gene of the sixth colony; we coined human hepatitis C virus binding protein 6(Hu Hcbp6) with Genbank, realized that the Hu Hcbp6 shares as much as 98% homology with two cDNA without knowing functions. We have proved that Hu Hcbp6 could interact with hepatitis C virus core protein. CONCLUSIONS: Hepatitis C virus core binding protein (Hu Hcbp 6 Genbank number: AY032594) was successfully cloned and identified. The study partly paved the way for investigating physiological function of the Hu Hcbp6.

Cloning, Molecular↗

PubMed2002

[Comparative studies on isolation and purification of Chinese medicine decoction].

OBJECTIVE: To evaluate different methods by treating water-decocted liquid of 6 Chinese medical herbs and 4 co-prescription respectively with alcohol, ultrafilter, macroporousresin and clarifier. METHOD: The contents of target component in those extracts were determined with HPLC or titration, and quantitative and qualitative determination of the impurity components, such as polysaccharide and protein, was made. RESULT: Each method showed its advantages and disavantages. CONCLUSION: Different method can be chosen according to the clinical and preparation demands or the characteristic of components.

Drug Combinations↗

PubMed2002

Cloning and expression of the gene of augmenter of liver regeneration in yeast cells.

OBJECTIVE: To study the function of augmenter of liver regeneration (ALR) as a regulatory factor that specifically stimulates hepatic cell regeneration, we constructed yeast expressive vector of ALR and expressed it in yeast cells. METHODS: Total RNA was extracted from HepG2 cells, and reverse transcription polymerase chain reaction (RT-PCR) was performed to amplify the coding region of ALR. The products were cloned into PGEM-T vector and sequenced, then cloned into PGBK T7 vector. The recombinant plasmid PGBK T7-ALR was transformed into yeast AH109. The yeast protein was extracted and analyzed by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blotting hybridization technique. RESULTS: DNA sequencing results confirmed that the coding region of ALR was correctly inserted into the yeast expression vector, and Western blotting assay showed that recombinant ALR was successfully expressed in yeast. Its molecular weight was identical to the theoretical value of 15 000 Da; the protein was found inside the yeast cells. CONCLUSION: The successful expression of ALR in yeast cells makes it possible to study further on its biological function.

Blotting, Western↗

PubMed2002

Cloning and expression of the preS1 gene of hepatitis B virus in yeast cells.

OBJECTIVE: To investigate the complex functions of HBV preS1 protein, we constructed HBV preS1 gene expression vector and expressed it in yeast cells. METHODS: Polymerase chain reaction (PCR) was performed to amplify the gene of HBV preS1 from the plasmid pCP10 containing the whole DNA fragment of HBV ayw subtype as template and the PCR product was cloned into the pGEM-T vector for sequencing. After being identified, the HBV preS1 gene was cut from the pGEM-T vector by EcoR I and Pst I restriction enzymes, and cloned into yeast expressive plasmid pGBKT7 to construct pGBKT7-preS1 recombinant expressive plasmid. This plasmid was transformed into yeast cell AH109 and expressed in it. The yeast protein was isolated and analyzed with sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) and Western blotting. RESULTS: The HBV preS1 gene was amplified successfully and identified by DNA sequencing. The PCR products were coincided completely with the reported sequence. The digested fragments were cloned into the pGBKT7 vector and transformed into yeast cell AH109. The results of SDS-PAGE and Western blotting assay showed: (1) The HBV preS1 protein was expressed and existed in yeast cells; (2) The molecular weight of the expression product was about 30 000 D. CONCLUSION: The HBV preS1 gene was successfully cloned and expressed in yeast cells.

Blotting, Western↗

PubMed2002

[Effects of Schwann cell-derived neurotrophic activity on cultured retinal ganglion cells survive and grow in normal and gas-deprived environment].

PURPOSE: To investigate the effects of Schwann cell-derived neurotrophic activity (SCNA) on cultured retinal ganglion cells (RGC) survive and the expression of growth associated protein 43 (GAP43) in normal and gas-deprived environment. METHODS: Schwann cells of new born SD rat were cultured, and remaded it into solutions containing different concentrations of SCNA. Then these solutions were added to the primarily cultured retinal cells, the activity of SCNA was determined by MTT method. The fluro-gold retrolabelled retina cells of 3d new born rats were cultured and plated on 24 well culture plate. At the 2rd day of culture, 300 mg/L SCNA were added into the medium of SCNA group. At the 5th day, liquid paraffin was added on the surface of medium of air deprived groups to lead an air deprived injury. Cultured for 12h, the liquid paraffin was discarded off, and then we observed the morphology and counted the fluro-gold labeled RGC. The effects of SCNA on the expression of GAP43 in cultured retinal cells were identified by Western Blot. RESULT: SCNA could promote the survival of RGC in a protein concentration-dependent manner. Added SCNA to the medium, the retinal cells grown much better and had less floating dead cells. The number of RGC was also significantly more than the control (F = 62.89, P < 0.01). The cells of air deprived group had showed swelling change. But the cells of group with SCNA are less affected and the number of RGCs is significantly different from the control (F = 49.27, P < 0.01). The expression of GAP43 in normal and air deprived groups with SCNA were up-regulated. CONCLUSION: SCNA has significantly neurotrophic effect on cultured RGC and increases the expression of GAP43. Added SCNA to the medium could reduce the injury of air deprived and promote RGC survival rate in this kind of injury environment.

Animals↗

PubMedDate not supplied

Chemiluminescence inhibition assay for folic acid using flow injection analysis.

A new flow injection method for the determination of folic acid is described. A fast oxidation reaction occurred when folic acid was mixed with potassium ferricyanide generating ferrocyanide which then inhibited the chemiluminescent reaction of ferricyanide and luminol in alkaline medium. The decrease of chemiluminescence intensity was correlated with the folic acid concentration in the range 0.1-21 microg/mL; the detection limit for the assay was 0.03 microg/mL (3sigma). A complete analysis of folic acid, including sampling and washing, could be performed within 2 min with a relative standard deviation of less than 4.0%. The proposed method has been applied successfully to the determination of folic acid in pharmaceutical preparations.

Ferricyanides↗

PubMedDate not supplied

Synthesis of diverse benzo[1,4]oxazin-3-one-based compounds using 1,5-difluoro-2,4-dinitrobenzene.

This paper discusses the synthesis of benzo[1,4]oxazin-3-one-based compounds from 1,5-difluoro-2,4-dinitrobenzene (1), including benzo[1,4]oxazin-3-ones (5-11) and five novel benzo[1,4]oxazin-3-one-based tricycles: 6-hydroxy-4H-1-oxa-4,5,8-triazaanthracen-3-one (14), 3,8-dihydro-5-oxa-1,3,8-triazacyclopenta-[b]-naphthalene-7-one (15, 17, 21), 3,8-dihydro-5-oxa-1,2,3,8-tetraazacylopenta[b]-naphthalene-7-one (16, 20), 3,8-dihydro-1H-5-oxa-1,3,8-triazacyclopenta[b]-naphthalene-2,7-dione (18, 22), and 5,8-dihydro-4H-1-oxa-4,5,8-triazaanthracene-3,6,7-trione (19). Finally, a chemical library based on 15 was synthesized in parallel solution-phase reactions.

Benzoxazines↗

PubMedDate not supplied

Etoposide differentially affects bone marrow and dermal derived endothelial cells.

Chemotherapy alteration of the bone marrow microenvironment has the potential to influence hematopoietic recovery following transplantation. To discern the effect of specific drugs on components of the complex marrow microenvironment, in vitro models have significant utility. In the current study we sought to determine whether dermal (HMEC-1) and marrow derived endothelial cells (BMEC-1) respond differently to identical chemotherapy exposure. BMEC-1 cells were consistently more sensitive to etoposide exposure than HMEC-1 cells, measured as reduced viability. BMEC-1 also had reduced focal adhesion kinase (FAK) and VCAM-1 protein expression following chemotherapy, in contrast to dermal derived endothelial cells in which neither protein was influenced dramatically by etoposide. The two endothelial cell lines had markedly different levels of baseline VE-Cadherin protein, which was modestly altered by treatment. These data indicate that marrow derived endothelial cells have disruption of specific proteins following chemotherapy that may influence their ability to facilitate hematopoietic cell entry or egress from the marrow. In addition, these observations suggest that while BMEC-1 and HMEC-1 share a variety of characteristics, they differ significantly in their response to stress and should be incorporated into specific models with this consideration.

Animals↗