Biomedical subjects

Wei Liu

Publications and source records attributed to Wei Liu.

At least 343 records · Page 19Linked to original sources

PubMed2004

A community-based cluster survey on preferences for treatment of diarrhoea and dysentery in Zhengding county, Hebei province, China.

Passive surveillance on the burden of disease due to diarrhoea will underestimate the burden if families use healthcare providers outside the surveillance system. To study this issue, a community-based cluster survey was conducted during October 2001 in the catchment area for a passive surveillance study in Zhengding county, a rural area of northern China. Interviews were conducted at 7 randomly-selected households in each of 39 study villages. The respondents indicated where they sought initial care for cases of diarrhoea or dysentery among children or adults. In the absence of diarrhoea and dysentery cases in the household in the preceding four weeks, the respondents were asked about healthcare use for a hypothetical case. Overall, 80% (95% confidence interval [CI] 67-93%) would chose the village clinic, 11% village pharmacy (95% CI 1-22%), 4% township hospital (95% CI -1-10%), 4% self-treatment (95% CI 1-8%), and 1% county hospital (95% CI 0-2%). Approximately, 84% of patients would seek treatment for diarrhoea and dysentery at centres participating in passive surveillance, suggesting that passive surveillance will provide a relatively accurate assessment of burden of diarrhoea in Zhengding county.

Adult↗

PubMed2004

[TH gene mutation in Chinese patients with autosomal recessive dopa-responsive dystonia].

OBJECTIVE: To explore the mutation of tyrosine hydroxylase(TH) gene in Chinese patients with autosomal recessive(AR) dopa-responsive dystonia(DRD) and to lay a solid basis for gene diagnosis of AR-DRD in China. METHODS: Mutation analysis of TH gene was performed in 5 probands with AR-DRD and 2 sporadic patients with DRD by use of polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) combining DNA direct sequencing. RESULTS: The PCR-SSCP analysis and DNA direct sequencing following PCR revealed no mutation in all the 14 exons of TH gene. CONCLUSION: The mutation rate of TH gene in Chinese patients with AR-DRD is low, hence suggesting the genetic heterogeneity and a new locus for AR-DRD.

Asian People↗

PubMed2004

[Cloning of the Aspergillus fumigatus squalene epoxidase gene].

OBJECTIVE: To clone Aspergillus fumigatus squalene epoxidase gene and to further investigate its role in terbinafine resistance. METHODS: The A.fumigatus genomic DNA library was transformed into pyrG-A. fumigatus strain protoplasts with polyethylene glycol-mediated transformation protocol. TRB-resistant pyrG+ transformants were then isolated by being plated on MM-U with TRB (0.625 mg/L) plates. After confirmation of terbinafine-resistance by using both disk diffusion and NCCLS M38-A microdilution antifungal susceptibility testing, the gene conferring terbinafine-resistance was identified. Finally, the gene was cloned and retransformed into pyrG-A. fumigatus strain. RESULTS: From a total of 5x10(4) transformants, one TRB-resistant pyrG+ transformant was isolated, which showed the terbinafine-specific resistance without cross-resistance to any other antifungals. A. fumigatus squalene epoxidase gene was further identified to confer this terbinafine-resistance. As a result, the complete A. fumigatus squalene epoxidase gene was firstly cloned. Finally, the transformants with extra copies of A. fumigatus squalene epoxidase gene, again, showed the specific resistance to terbinafine. CONCLUSION: Extra copies of A. fumigatus squalene epoxidase gene, which was cloned for the first time in this study, could result in A. fumigatus resistance to terbinafine. This is a novel mechanism of terbinafine-resistance that needs further investigation for its clinical significance.

Amino Acid Sequence↗

PubMed2004

[Application of molecular biology techniques in the identification of pathogenic fungi and the diagnosis of fungal infection].

With the increasing incidence and mortality of fungal infection, the requirements for strict diagnostic approaches became a very urgent issue. Because of the traditional detective techniques, such as culture, gave poor diagnostic outcomes, the molecular biological techniques are expected to develop the potential diagnostic approaches. During the past decades, we have carried out serial studies on the molecular properties of pathogenic fungi, and we would like to review as following. Firstly, we applied several molecular tools in classification and identification of pathogenic fungi. We performed random amplification of polymorphic DNA (RAPD), restriction fragment length polymorphism (RFLP) and other techniques in studying the typing, to classify and identify the properties of Dermatophytes, Candida spp., Cryptococcus neoformans, Dematiaceous fungi, and Aspergillus spp. Interestingly, we found the same T. rubrum strain might infect different sites of the host, while a site-specificity displayed in T. mentagrophytes. This finding indicated the genetic discrepancies among the fungi. Beside, we also found that the E. dermatitis strains with different virulences possessed some discrepancies at gene level. We then developed a PCR-based molecular procedure to identify the novel species in Exophiala spp. As the applicable strategy, we also investigated the rDNA sequence properties in several fungi. And as a result, we submitted for the first time to GenBank the complete sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, which provided the basis for designing the species-specific probes and for its further clinical applications. Secondly, we have tried to develop the molecular diagnostic approaches based on our DNA sequence data which were used for identification studies previously. By analyzing the DNA sequence of Aspergillus fumigatus rDNA/ITSI/ITSII, we developed a nested PCR method to detect Aspergillus fumigatus genes. Our preliminary results indicated that this PCR-based molecular approach has great importance in the diagnosis of invasive aspergillosis. We also designed the species-specific probes and then established several in situ hybridization procedures. We found these hybridization methods could get the positive rate up to 81% (13/16), which suggests that these methods have potential diagnostic value for invasive candidiasis and aspergillosis. Based on our experiences, we would conclude that the molecular biological techniques possess great value to investigate the biological properties of pathogenic fungi, and we are looking forward to see more and more molecular tools will be used in the pathogenic mechanisms of fungal infections and antifungal activity studies.

Aspergillosis↗

PubMed2004

Relationship between HLA-DQA1 polymorphism and genetic susceptibility to idiopathic dilated cardiomyopathy.

BACKGROUND: Autoimmune mechanisms are likely to participate in the pathogenesis of subgroup of idiopathic dilated cardiomyopathy (IDC), and components of the major histocompatibility complex may serve as markers for the propensity to develop immune-mediated myocardial damage. Human leukocyte antigen (HLA) class II genes, especially highly polymorphic HLA-DQ genes, play an important role in the activation of immune responses, and thus control the predisposition for or protect from IDC. This study was conducted to investigate the HLA-DQA1 allele polymorphisms in IDC patients and to explore the underlying immunological mechanism and the hereditary susceptibility to IDC. METHODS: The polymerase chain reaction sequence-specific primers (PCR-SSP) technique was used to analyze the polymorphisms in the second exon of DQA1 in three groups: 72 IDC patients diagnosed according to the criteria of World Health Organization (IDC group); 100 end-stage heart failure patients suffering from a disease of known etiology (HF group); and 100 healthy subjects enrolled for the study during a routine health survey (control group). Patients in the IDC group were stratified according to ejection fraction (EF). Those with EF values were higher than 35% were placed into subgroup 1; subgroup 2 included patients with an EF value of 15% - 35%; and subgroup 3 consisted of those whose EF values less than 15%. RESULTS: The frequency of HLA-DQA1 *0501 alleles was significantly higher in the IDC group (0.39) than that in the HF group (0.12) and the control group (0.09) (both P < 0.05). Further analysis of the three IDC subgroups showed a higher frequency of DQA1 *0501 among patients with lower EF values (both P < 0.05, compared with subgroups 1 and 2). The frequency of DQA1 *0201 was higher in the control group than that in the IDC group (P < 0.05). CONCLUSIONS: The HLA-DQA1 *0501 allele confers susceptibility to IDC, while the DQA1 *0201 allele confers protection against it, which indicates that genetic background involved in IDC and heart failure is different. HLA-DQA1 genes are involved in the regulation of specific immune responses by auto- or foreign anti-myocardium antibody.

Adolescent↗

PubMed2004

[A case-control study on the risk factors of severe acute respiratory syndromes among health care workers].

OBJECTIVE: To study the factors in relation to severe acute respiratory syndromes (SARS) among health care workers and to develop related protective measures. METHODS: Case-control study was applied. A standardized questionnaire was used to collect SARS related information for health care workers who had contacted or treated SARS patients. Univariate analysis was conducted using SPSS 10.0 software package and multivariate logistic regression analysis was conducted using SAS 6.12. RESULTS: Twenty-seven of the 49 factors under study were significantly associated with SARS infection, in which 22 factors were protective, and the other 5 were risk factors. 27 factors were included for multivariate logistic regression analysis. Results showed that six factors as wearing eye glasses, wearing protection gowns, exposure to secrets/mode of contact with SARS patients, types of mask and the working years atc, remained significant association with hospital infection of SARS. CONCLUSION: SARS infection in heath care workers was related to many factors during the process of diagnoses and/or treatment. It is recommended that adequate masks, eye-protection and protective gowns should be adopted for heath care workers during the process of clinical diagnoses and treatment of SARS patients.

Case-Control Studies↗

PubMed2004

[Imaging diagnosis and interventional therapy of transplant renal artery stenosis].

OBJECTIVE: To discuss the diagnostic methods of transplant renal artery stenosis (TRAS) and clinical outcome following percutaneous transluminal angioplasty. METHODS: Of 24 patients with TRAS screened by color Doppler ultrasound and confirmed with digital subtraction angiography, balloon angioplasty was performed in 19 patients, and 5 patients received stent implantation, including 2 cases of recurrent stenosis. RESULTS: Technical success was achieved in all procedures with no serious complications. The blood pressure and serum creatinine levels of all patients were remarkably decreased (P < 0.01). Renal functions of the two patients with restenosis were significantly improved after intra-arterial stenting. CONCLUSIONS: Doppler ultrasonography is useful in the screening and follow-up of TRAS and arteriography is still the definite diagnostic method. Percutaneous transluminal angioplasty and stenting are safe and effective procedures to treat TRAS.

Adult↗

PubMed2004

[Endoscopic thyroid gland surgery without carbon dioxide neck insufflation].

OBJECTIVE: To evaluate endoscopic thyroid gland surgery without carbon dioxide neck insufflation. METHODS: Sixteen patients with thyroid gland benign tumor, aged from 23-62 years, were selected and treated with endoscopic surgery. Eight cases received whole thyroid lobectomy and the other eight cases received partial thyroid lobectomy, the procedure was through a wall method or a single 2.0-3.0 cm horizontal skin incision. Among the 16 cases, 6 were thyroid adenoma and 10 were nodular goiter. RESULTS: All patients received endoscopic surgery, 2 cases with sub-clavicle approach and 14 cases with a single 2.0-3.0 cm horizontal skin incision approach. The recurrent laryngeal nerve and parathyroid glands were easily identified and preserved during operation, the operating time lasted from 1.1 hours to 4.0 hours, no complication occurred, the postoperative cosmetic outcome was excellent. CONCLUSIONS: The results indicated that gasless technique is feasible and safe, so it suggested that the video-assisted thyroid surgery without carbon dioxide neck insufflation could be an alternative for thyroid gland surgery.

Adult↗

PubMed2004

[Study on the acute toxicity experiment of mice and anti-tumor function in vitro of the qinglongyi].

OBJECTIVE: To study the anti-tumor effect and acute toxicity in vitro of the separation compositions from qinglongyi. METHOD: The conventional acute toxicity experiments of mice, the MTT [3-(4,5-dimethylthiazol-2 yl)-2,5-diphenylterazolium bromide, MTT] and the SRB (sulforhodamin B) were used to make preliminary selection to qinglongyi and its separation compositions. RESULT: The half-deadly dose (LD50, the half-lethiferous dose) of the chloroform separation composition in qinglongyi was 575.38 mg x kg(-1) (i.g.), and of the acetic ether separation compositions in qinglongyi was 1303.59 mg x kg(-1) (i.g.). From the other parts of separation compositions in qinglongyi, the LD50 were more than 5 g x kg(-1). When acetic ether separation composition of qinglongyi was at 100 microg x mL(-1) the growth inhibitory rate (GIR) was < 50% to the leukaemia cell HL-60 of human. When chloroform separation composition and the acetic ether separation compositions of qinglongyi was at 100 mg x mL(-1), GIR was 52% to the leukaemia cell HL-60, the gastric carcinoma cell BGC-823 and the cervical carcinoma cell Hela of human. CONCLUSION: The separation composition of the chloroform and the acetic ether from qinglongyi have obvious, anti-tumor effect.

Animals↗

PubMed2004

[Age-related changes in growth and metabolism function of human costal chondrocytes cultured in vitro].

OBJECTIVE: To investigate the expressive changes of collagen I, II and aggrecan during the aging of the human costal chondrocytes cultured in vitro, in order to select the best chondrocytes for cartilage engineering. METHODS: The human costal chondrocytes from the different passages (P1-P5) were harvested. The morphological changes and cell proliferation rate were observed, and the quantity of glycosaminoglycans (GAGs) was examined in each passage with alcian blue precipitation. The expression of collagen I, II and aggrecan was measured with immunohistochemistry and RT-PCR method. RESULTS: From the third passage, the human costal chondrocytes were transformed into fibroblast-like cell morphology; and the GAGs content in each passage was decreased and became significantly low in the third passage. The expression of the collagen I, II was consistent in the protein level with that in the mRNA level. Before the second passage, the expression of collagen II was high while the collagen I was low. After the second passage, the expression of collagen II decreased while the collagen I increased. The expression of aggrecan was high before the third passage, and then became low in the fourth passage. CONCLUSION: With the examinations of the cell proliferating rate and cell functions in human chondrocytes cultured in vitro, the chondrocytes of the second passage seem suitable for human cartilage engineering.

Aggrecans↗

PubMed2004

[Evaluation of anti-HCV detection kits using recombinant antigens derived from various HCV regions].

OBJECTIVE: To evaluate the first and second assay kits currently used in blood centers for screening HCV infected blood, and to provide basis for a better match of the two assay kits. METHODS: Using the newly developed multi-recombinant-HCV-antigen supplementary assay kit, the authors evaluated concurrently the specificity and sensitivity of two domestic and one imported anti-HCV detection kits. RESULTS: Discrepancy in specificity and sensitivity existed among the two domestic HCV kits, and overall quality was slightly below that of leading or main stream imported HCV kit. CONCLUSION: The newly developed multi-recombinant-HCV-antigen supplementary assay kit is useful in the evaluation of HCV antibody detection kit currently in use. It provides qualified assessing kit to capture antibodies against various HCV antigens. The present paper provided guidance for selecting a better match of the two screening kits and improved screening efficiency.

Blood Donors↗

PubMed2004

[Application of Neuroform stent in the treatment of intracranial aneurysm].

OBJECTIVE: To introduce the application of Neuroform stent in the treatment of intracranianl wide neck aneurysm. METHODS: Eight patients (9 aneurysms), including 3 males and 5 females, aged from 41 to 74, were treated. Among the 9 aneurysms, there were 3 wide-neck aneurysms in internal carotid artery (ICA), 4 vertebral aneurysms (in 3 cases), and 2 basilar tip giant aneurysms. Heparinization were given for all procedures after femoral artery Seldinger's puncture. Stents were released through 3 m Transcend 0.014 guide wires, which were posited in the aneurysm-carry arteries first, or, through a 205 cm Transcend 0.014 guiding wire. Further coiling was selected for some cases. After the treatment 24 h heparinization were maintained. For coiling cases, aspirin (300 (mg/d) and ticlopiding (250 mg/d) were given at first 6 weeks, and aspirin (300 mg/d) was given following 6 months. For stent alone cases, only 1 month aspirin (300 mg/d) was given. RESULTS: In one ICA aneurysm, the stent moved to the bifurcation of ICA while a coil was pushed into the aneurysm lumen, and the ICA spasmed. Partial occlusion achieved in the aneurysm. The patient died due to bleeding of the aneurysm 20 h after anticoagulation treatment with heparin. One dissection aneurysm and 2 fusiform aneurysms (in bilateral vertebral arterys of one patient) were treated with stents only. The dissection aneurysm was completely occluded after 3 months. In 1 basilar artery (BA) tip giant aneurysm, the distal part of BA spasmed immediately after stenting. Complete occlusion was achieved with coils 4 months later. Another BA tip aneurysm was partially occluded after the stent was deployed. The other 3 aneurysms were completely embolized with the protection of the Neuroform stents. There is no further DSA follow-up of the cases. CONCLUSIONS: The Neuroform stent is easy to pass through the tortuous vessels. Combine with coils, it may be used in the treatment of wide neck aneurysms. However, it has the risk of migration because of the softness.

Adult↗

PubMed2004

[Comparison of preemptive analgesia efficacy between etoricoxib and rofecoxib in ambulatory gynecological surgery].

OBJECTIVE: To compare the preemptive analgesia efficacy between two cycloxygenase-2 inhibitors, rofecoxib and etoricoxib in the ambulatory uterine evacuation patients. METHODS: In this randomized, double-blinded, placebo-controlled trial 60 patients were randomly divided into three groups and received a single dose of placebo, rofecoxib 50 mg, or etoricoxib 120 mg, respectively, before operation. Patient's visual analogue score (VAS) was rated postoperatively at 15 min, 30 min, 60 min, time-to-discharge, 6 h and 24 h. Fentanyl (in post-anesthesia care unit) and paracetamol (at home) were supplementary analgesics and the dosage was also recorded. Patient's satisfaction score was rated at 24 h postoperatively. RESULTS: Etoricoxib 120 mg and rofecoxib 50 mg were significantly superior to placebo at 6 h postoperatively (P < 0.05) while there was no significant differences of VAS at other time points. The amounts of Fentanyl used in post-anesthesia care unit were similar in three groups, but paracetamol taken at home was much less in rofecoxib group and etoricoxib group than in placebo group (P < 0.01). Compared to rofecoxib, etoricoxib provided better pain relief after discharge (P < 0.05). The overall pain management satisfaction score was significantly higher in etoricoxib group (96 +/- 7) than in other groups (P < 0.01). CONCLUSION: Preemptive rofecoxib 50 mg and etoricoxib 120 mg may significantly decrease VAS at 6 h postoperatively, and reduce the usage of analgesics in ambulatory uterine evacuation patients. Etoricoxib 120 mg offeres better pain relief at home compared with rofecoxib 50 mg.

Abortion, Induced↗

PubMed2004

Effects of integrin alpha IIb(R995A) mutation on receptor affinity and pp125 (FAK) phosphorylation.

OBJECTIVE: To investigate the role of cytoplasmic domain of integrin alpha IIb in platelet signal transduction. METHODS: Binding capacity of integrin alpha IIb(R995A) to antibody platelet activation complex-1 (PAC-1) and pp125 focal adhesion kinase (FAK) phosphorylation of cells were detected by flow cytometry, immune precipitation, and Western blotting. RESULTS: Without activation, wild-type alpha IIb beta3 Chinese hamster ovary (CHO) cells failed to bind to PAC-1, but mutant chimera alpha IIb(R995A)beta3 CHO cells were able to bind with PAC-1. Furthermore, phosphorylation of pp125 (FAK) in wild-type alpha IIb beta3 CHO cells occured only when cells were adhered to fibrinogen, but could not be detected in bovine serum albumin suspension. However in the mutant chimera group, it could be detected in both conditions. CONCLUSION: The mutation in integrin alpha IIb(R995A) alters its affinity state as a receptor, thus also mediating cytoplasmic signal transduction leading to the phosphorylation of pp125 (FAK) without ligand binding.

Animals↗

PubMed2004

[Diagnosis and management of uterine arteriovenous fistula with massive vaginal bleeding].

OBJECTIVE: To study the clinical manifestation, diagnosis, management and prognosis of uterine arteriovenous fistula with massive vaginal bleeding. METHOD: The clinical records of 15 patients who satisfied the diagnostic criteria were retrospectively analyzed. RESULTS: All patients had massive vaginal bleeding, with a history of caesarean section, curettage or gynecologic carcinoma. The disease could be diagnosed by angiography or color Doppler ultrasound. Vaginal bleeding was aggravated by dilation and curettage. Fourteen patients were treated with uterine artery embolization, and no complications occurred postembolization. Of the eleven successful embolizations, all patients returned normal menstrual cycling. Five of these patients became pregnant later. CONCLUSIONS: Uterine arteriovenous fistula is a rare and potentially life threatening disease. Uterine artery embolization is a safe and effective treatment for this disease, and it can preserve normal function of uterus and ovaries.

Adult↗

PubMed2004

[Simultaneous determination of Pb, Cd, Cr and Co released from ceramic ware by ICP-AES].

The method for the determination of Pb, Cd, Cr and Co released from ceramic ware by ICP-AES has been presented. The factors such as the influence of power in 4% acetic acid, the selection of analytical wavelength, and the interference of coexistent element have been investigated. The detection limits were 6.8 microg x L(-1) for Pb, 0.18 microg x L(-1) for Cd, 0.61 microg x L(-1) for Cr, 1.0 microg x L(-1) for Co. The recovery rates of the procedure were between 98% and 104%. The RSDs were between 0.27% and 1.24%. The method was simple, rapid, precise, convenient and suitable for daily inspection of import and export ceramic ware.

Cadmium↗

PubMed2004

[Study on the reaction between cobalt tetrasulphonated phthalocyanine and sodium sulfide].

A new method which uses multi-wave number and double-parameter to analyse the UV-Vis. spectra is proposed to determine the composition and stabilization constants of coordination compounds. With this method, the reaction of cobalt tetrasulphonated phthalcyanine [CoTsPc] and sodium sulfide [Na2S] was studied. The result shows that pH of the medium has great effect on the reaction. A five coordinated compound Co(II)TsPc(HS) was formed at pH = 7.0. The equilibrium constants and thermodynamics are reported for the reaction under that condition. At higher pH, a redox-reaction took place and a five coordinated compound with the oxidation number I for cobalt [SCo(I)TsPc] was found.

Cobalt↗

PubMed2004

[Experimental study on biological character changes of human epidermal cells during proliferation culture in vitro].

UNLABELLED: [Abstract] OBJECTIVE: The study was (1) to investigate the biological character changes of human epidermal cells during proliferation culture in vitro and (2) to provide data for construction of engineered skin. METHODS: The foreskin was collected from 20 healthy children. The epidermal cells were isolated with digestion of the foreskin and cultured in vitro. Growth curve was obtained from the data of cell counting. Cell growth kinetics was observed. Meanwhile, clonal analysis and cell size measurement was performed. The rate of keratin 19 (K19) and involucrin expression-positive cells was counted by flow cytometer. Expression of K19 and involucrin mRNA was detected by RT-PCR. RESULTS: When passaged to P6, the keratinocytes from child foreskin could be expanded by (700 +/- 37) times. Flow cytometer results showed that the percentage of K19 expression-positive cells decreased from (66.97 +/- 3.14)% to (4.65 +/- 1.38)% while the percentage of involucrin expression-positive cells increased from (11.65 +/- 1.62)% to (97.03 +/- 2.66)% at P0 and P6 respectively. RT-PCR results showed that expression of K19 mRNA decreased from P0 to P6 while involucrin mRNA kept stable with passage in vitro. CONCLUSIONS: Human epidermal cells of passage 5 maintain proliferation phenotype, which are suitable for skin tissue engineering. Decrease of proliferation phenotype content is partially responsible for the proliferation capacity loss of in vitro cultured epidermal cells.

Cell Proliferation↗