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Biomedical subjects

W Xu

Publications and source records attributed to W Xu.

At least 271 records · Page 15Linked to original sources
PubMed1999

Impact of clozapine on negative symptoms and on the deficit syndrome in refractory schizophrenia. Department of Veterans Affairs Cooperative Study Group on Clozapine in Refractory Schizophrenia.

OBJECTIVE: This study compared the effect of clozapine and haloperidol on positive and negative symptoms of schizophrenia and in patients with high levels of negative symptoms or the deficit syndrome. METHOD: Patients were participants in a 15-site double-blind, random-assignment Veterans Administration trial comparing clozapine (N=205) and haloperidol (N=217) in hospitalized patients with refractory schizophrenia. Analysis of covariance examining change at 6 weeks, 3 months, and 1 year evaluated 1) clozapine's effect on positive and negative syndromes; 2) clozapine's effect on each syndrome, statistically controlling for the other; and 3) the interaction of clozapine treatment and the presence or absence of high levels of negative symptoms at baseline and the deficit syndrome. RESULTS: Patients treated with clozapine showed significantly greater improvement than control subjects on positive symptoms at all time points and on negative symptoms at 3 months. Clozapine had no independent effect on negative symptoms at any time after control for positive symptoms, but its effects on positive symptoms persisted after control for negative symptoms at 6 weeks only. There were no significant differences in response to clozapine between patients with high and low levels of negative symptoms at baseline or between patients with and without the deficit syndrome. CONCLUSIONS: The greater effectiveness of clozapine as compared to conventional medications in refractory schizophrenia is not specific to either negative clinical symptoms or clinical subtypes defined by prominent negative symptoms or evidence of the deficit syndrome.

Analysis of Variance↗
PubMed1999

Regulation of growth and apoptosis of breast cancer cells by a 54 kDa lymphokine.

A normal human lymphocyte-derived 54 kDa polypeptide, capable of regulating cell growth has been identified as an isoform variant (abbreviated as NP54) of protein neuroleukin-phosphoglucose isomerase (PGI). Since distinct PGI variants undetectable in normal tissues had been identified in breast cancer tissues, the effect of NP54 on the growth of human breast cancer cells SK-Br-3 in cultures was analyzed. Exposure to NP54 caused a dose-dependent growth modulation. Approximately 40% reduction of cell density was detected at 40 pM of NP54, along with a blocking of G1 cells entering into S phase. The growth modulation was correlated with a significantly reduced expression of epidermal growth factor receptor (EGF-R) gene transcript, supporting the interpretation that the level of EGF-R expression and cell growth are related mechanisms. NP54 treatment also significantly increased cells with apoptotic morphological feature and fragmented DNA. Incubation with a monoclonal anti-NP54 antibody negated NP54 activity, confirming a regulatory activity in cell growth and apoptosis.

Antibodies, Monoclonal↗
PubMed1999

Development of human prostate cancer cells to neuroendocrine-like cells by interleukin-1.

Growth and development of some prostate epithelial cells are androgen-dependent. Non-androgenic hormones and growth factors may also influence prostate cells and the effect of interleukin 1beta (IL-1beta) has been investigated with an androgen-dependent human prostate cancer cell line LNCaP. Exposure of LNCaP cells to IL-1beta at picomole ranges resulted in a dose-dependent and progressive differentiation to neuroendocrine-like cells evidenced by dendrite formation and the development of specific neuroendocrine cell markers. Quantification by computer-based image analysis after immunostaining revealed a two-fold increase of chromogranin A in 90% of the cells and a ten-fold increase in the remaining 10%. Additionally, serotonin was developed in all the cells with the staining intensity increased by five-fold. Significant increase in cytokeratin 8 and reduction of prostate specific antigen was also noted. Proliferation was reduced in parallel to the cellular development. The IL-1beta effect was irreversible after several days of IL-1beta incubation. IL-1beta is produced constitutively and its secreted level has an inversed relation during the exponential and plateau phases of cell growth. An IL-1 autocrine regulation in the growth and differentiation of prostate cells is discussed.

Biomarkers↗
PubMed1999

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

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

Adult↗
PubMed1999

[Gene expression of growth factors and their receptors in healing of partial thickness burn wound in rats].

OBJECTIVE: To investigate the role of growth factors and their receptors in partial-thickness burn wound healing. METHODS: SD rats were used. After 10% total body surface area partial-thickness burn, wound tissues were harvested on postburn days (PBDs) 0(normal control), 1, 3, 5, 7, 10 and 14 respectively. The gene expressions of growth factors and their receptors were determined in wound by in situ hybridization and slot blotting hybridization. At the same time, the process of the wound healing was observed histologically, and the regeneration cycle of epidermal cells and the temporal change in inflammatory cells were measured. RESULTS: Inflammatory cells infiltrated into wound surface were neutrophils, followed by macrophages and lastly lymphocytes. Epidermal cells proliferated most actively on PBD 3 and the mitoses of them increased significantly on day 7 after burn. The gene expression of PDGF, PDGFR and EGFR reached peaks on PBD 1 and the gene expression of EGF and TGF beta-R2 were highest on PBD 3. In addition, the gene expression of TGF beta-R1 and TGF beta 1 increased significantly on PBDs 5 and 7 respectively. CONCLUSION: The data suggested that burn can induce gene expression of EGF, PDGF, TGF-beta 1 and their receptors temporally, spatially, and reversibility, which might play a major role in burn wound healing, and the mutual regulation may exist in the gene expression and the cell cycle.

Animals↗
PubMed1999

A recombinant multi-epitope, multi-stage malaria vaccine candidate expressed in Escherichia coli.

OBJECTIVE: To construct and evaluate a recombinant multi-epitope, multistage malaria vaccine candidate expressed in Escherichia coli (E. coli). METHODS: A hybrid gene (HGF) encoding several putative immunodominant T or T/B epitopes from MSP-1, MSP-2, Pf155/RESA of Plasmodium falciparum (P. falciparum) and two immune-stimulating epitopes from interleukin-1 and tetanus toxin was synthesized. Two copies of HGF and a copy of gene encoding Pattaroyo's Spf66 were connected together to construct a sandwich hybrid gene HGFSP. The gene was cloned into an expression vector pWR450-I for production of a fusion protein with beta-galactosidase. Efficacy of this vaccine candidate in inducing specific immunity against malaria parasites was evaluated. RESULTS: Immunization of different species of animals with purified recombinant peptide showed that the peptide was able to induce remarkable antibody response to the immunized peptide as well as falciparum malaria parasites. The epitopes included in the construct could induce antibodies against the intact parasite proteins as demonstrated by western blotting, indicating the epitopes retained their antigenicity in the new peptide construct. Antibodies from animals immunized with recombinant HGFSP peptide exhibited good ability in inhibition of the in vitro growth of malaria parasites, augmentation of phagocytosis of the parasites or infected RBC by phagocytes, and facilitation of antibody dependent cell mediated cytotoxicity to the cultured malaria parasites. CONCLUSION: The recombinant peptide seems to be a potential candidate which is valuable for further investigation.

Animals↗
PubMed1999

Isolation and identification of Mycoplasma genitalium from high risk populations of sexually transmitted diseases in China.

OBJECTIVE: To investigate Mycoplasma genitalium (Mg) infection in high risk populations of sexually transmitted diseases (STDs) in China by means of culture, Mg-DNA detection, observation under an electron microscope (EM) and an atomic force microscope (AFM). METHODS: 227 urogenital specimens taken from both patients in clinics and high risk populations of STDs in Beijing, Nanjing and Shanghai areas were cultured in SP-4 medium for isolation of Mg. Suspicious positive strains were identified first by PCR technique which could amplify the special DNA fragments of Mg adhesion protein (Mg-Pa) and 16S-rRNA sequences. The morphologic features of Mg were observed under EM and AFM. RESULTS: Eight strains were isolated from the 227 specimens, the total positive rate was 3.52%. The isolated strains met the criteria of growth and metabolic conditions required by Mg. Specific fragments of Mg-DNA (374 bp based on Mg-Pa and 402 bp on 16S-rRNA primers, respectively) could be amplified from both the isolates and the genital secretions. Under EM and AFM, Mg showed different shapes, including flask, pear, spindle and globe shape. The typical shape of Mg was flask or pear shape with projecting neck portion and broadened terminal structure under EM and with constrictive ring between the neck and body under AFM. CONCLUSION: Mg infection exists in high risk populations of STDs in China. We highly suggest the use of AFM in dermatological study.

Cervix Uteri↗
PubMed1999

Dose-effect of dietary L-arginine supplementation on burn wound healing in rats.

OBJECTIVE: To investigate the dose-effect of dietary L-arginine supplementation on burn wound healing in rats. METHODS: 218 Sprague-Dawley rats (weighing 200-250 g) were subjected to 10% deep partial thickness scald burns and were randomized into six groups. Groups A, B, C, D, E and F received 800, 400, 200, 100, 50 and 0 mg.kg-1.d-1 L-arginine in the form of L-arginine solution, and 0, 727, 1090, 1272, 1364, and 1454 mg.kg-1.d-1 glycine, respectively. Each solution was isonitrogenous. The times of completing re-epithelization were recorded. The contents of hydroxyproline (OHP) in burn wound area (index of reparative collagen synthesis) and the ratios of type I and type III collagen were examined in all groups. RESULTS: The times of completing re-epithelization (day) in groups A, B, C, D, E, and F were 24.9 +/- 1.95, 22.5 +/- 2.0, 20.2 +/- 2.4, 23.5 +/- 2.6, 23.8 +/- 3.5, and 24.7 +/- 2.3, respectively. The contents of hydroxyproline in groups B, C and D were higher than in groups A, E and F on PBD 7, 10 and 14. The ratios of type I and type III collagen in groups B, C and D were lower than in groups A, E and F. CONCLUSION: Oral dietary L-arginine supplementation from 100 mg.kg-1.d-1 to 400 mg.kg-1.d-1 shortened the times of re-epithelization, increased amounts of hydroxyproline, and accelerated the synthesis of reparative collagen in burn rats.

Animals↗
PubMed1999

Comparative frequency of bone sarcomas among different racial groups.

OBJECTIVE: To analyse comparatively the relevant data from bone tumor registries in China, Japan, and the United States. METHODS: The data of 38,959 histologically confirmed primary bone tumors collected by the Chinese Bone Tumor Registry 1957-1988, 20,272 collected by the Japanese Bone Tumor Registry 1972-1990, and 11087 diagnosed and treated at Mayo Clinic, USA were used for comparative analysis by race, age, sex and skeletal distribution. For reliability, we used ratios of different tumors to osteosarcoma for frequency analysis. We also included some data from the SEER 1973-1987 as well as from Memorial Sloan-Kettering Cancer Center, USA. RESULTS: The relative frequency of osteosarcoma (OS) is higher in China and Japan than in the United States. There were only limited number of OS patients aged over 50 years in Chinese and Japanese groups, which might be due to the lower incidence of OS subsequent to Paget's disease in Asians. More osteosarcoma occurred in the flat bones in the Americans than in the Chinese and Japanese. The relative frequency of chondrosarcoma (CS) was higher in the American group than in the Asian groups. The average age of CS patient was younger in the Chinese than in the Japanese and the Americans. The data confirmed the previous report that the incidence of Ewing sarcoma was higher in western people than in Asians. The data showed that the comparative frequency of chordoma is higher in the Americans than in the Asians and that the incidence of giant cell tumor of bone is higher in the Chinese and Japanese than in the Americans. CONCLUSIONS: The findings from this analysis provide useful information for the epidemiologic study and the clinical diagnosis of bone tumors.

Adolescent↗
PubMed1999

[Microvessel quantitation and expression of VEGF in colorectal tumors].

OBJECTIVE: To evaluate angiogenesis in colorectal tumorigenesis and to assess the prognostic significance of microvessel quantitation and VEGF status. METHODS: Thirty two colorectal carcinomas, 5 adenomas and 10 normal mucosa were studied immunohistochemically for microvessels and expression of VEGF. RESULTS: The mean vascular density (MVD) was 11 +/- 4 in normal mucosa, 28 +/- 11 in adenomas, and 50 +/- 22 in carcinomas (normal versus adenomas P > 0.05; normal versus carcinomas P < 0.01; adenomas versus carcinomas P < 0.05). MVD varied with tumor cell differentiation and tumor stage, but the differences were not significant. The expression of VEGF is closely associated with angiogenesis. Both MVD and VEGF expression were associated with prognosis. CONCLUSION: VEGF status and MVD are of prognostic significance in colorectal cancer patients.

Colorectal Neoplasms↗
PubMed1999

[Effect of immunologic treatment on lymphocyte subsets in patients with myasthenia gravis].

OBJECTIVE: To study the abnormalities of cellular immunity of myasthenia gravis (MG) and the effects of glucocorticoid (GC) therapy and thymectomy on lymphocyte subsets in patients with myasthenia gravis. METHODS: Phenotypic analysis of peripheral blood lymphocyte in 39 patients with MG and 18 healthy controls were completed using flow cytometry and immunofluorescence double-staining methods; changes of lymphocyte subsets were studied in 15 of the MG patients after GC therapy and 7 of the MG patients after thymectomy. RESULTS: (1) The percentage of pan-T (CD(+)(5)), pan-B (CD(+)(19)), traditional B cell, CD(+)(4)T cell in patients with MG did not significantly differ from that in healthy controls. An increase in CD(+)(8) cell was observed in MG patients as compared with normal controls. Among the CD(+)(4) T lymphocyte subsets, there was significant decrease of the percentage of CD(+)(4) CD(45)RA(+) (suppressor-inducer) and increase of the percentage of CD(+)(4) CD(45)RA(-) (helper-inducer) subsets in MG patients than controls; the percentage of CD(+)(5) B cell was significantly increased in MG patients as compared with that in healthy controls. (2) After GC therapy, the percentages of pan-T (CD(+)(5)), pan-B (CD(+)(19)), traditional B cell, CD(+)(4) T cell, CD(+)(8) T cell, CD(+)(4) CD(45)RA(-), CD(+)(5) B cell decreased. (3) After thymectomy, the proportions of T, B lymphocyte subsets did not change significantly. CONCLUSION: Not only changes of T cell subsets (CD(+)(4) and CD(+)(8) T lymphocyte subsets) were shown, but also there were abnormal changes of functional CD(+)(4) T lymphocyte subsets and CD(+)(5) B lymphocyte which may play an important role in the pathogenesis of MG. There is comprehensive inhibiting action of GC on cellular immunity in MG patients, while there is no such effect with thymectomy on the lymphocyte subsets in MG patients.

Adolescent↗
PubMed1999

[The potential role of cytokine expression and its relation to angiogenesis in idiopathic pulmonary fibrosis].

OBJECTIVE: The expression of insulin-like growth factor (IGF)-I and platelet-derived growth factor (PDGF) in open lung biopsies from patients with idiopathic pulmonary fibrosis (IPF) was studied to investigate their precise role in the development of fibrosis in IPF. METHODS: The distribution and expression of IGF-I and PDGF were examined in lung sections of IPF patients with antibodies and cDNA probes of IGF-I and PDGF by immunohistochemistry and in situ hybridization. RESULTS: IGF-I was predominantly localized in vascular smooth muscle cells and vascular endothelial cells of newly formed vessels in IPF. Smooth muscle cells of pulmonary arteries which underwent hypertrophy and hyperplasia strongly expressed IGF-I (+ + +). Type II cells, alveolar macrophages, and interstitial cells were also stained with anti-IGF-I, but with lesser intensity (+). PDGF-AA and BB were localized in hyperplastic bronchio-alveolar epithelial cells and interstitial fibroblasts (+ + +). Alveolar macrophages, vascular endothelial cells and smooth muscle cells were also stained positive (+ +). CONCLUSION: IGF-I and PDGF promote angiogenesis and vascular smooth muscle cell hypertrophy and hyperplasia, which contribute to the progression of fibrosis in IPF. IGF-I and PDGF are also involved in reepithelization and fibroproliferation in IPF through interaction with mesenchymal cells.

Adult↗
PubMed1999

[The potential role of cytokines expression in idiopathic pulmonary fibrosis].

OBJECTIVE: To investigate the protein and gene expression in bronchoalveolar lavage cells and open lung biopsies from patients with IPF. METHODS: The immunohistochemical methods were used to analyze the expression of PDGF, TGF-beta in bronchoalveolar lavage cells of patients with IPF. For open lung biopsies, both immunohistochemistry and in situ hybridization were used. RESULTS: In specimens of bronchoalveolar lavage fluid, PDGF-AA, PDGF-BB, TGF-beta were localized to alveolar macrophages in patients with IPF. Though there were no differences between IPF and sarcoidosis in terms of the staining intensity (2.5 - 3.0) or number of positive cells 81% - 90%, the number of such cells were less in the control (0 - 1.7, 25% - 32% respectively). Evaluation of open lung biopsies from patients with IPF showed that PDGF, TGF-beta proteins were localized to hyperplastic bronchio-alveolar epithelial cells (2.4 - 3.7, in control 0), alveolar macrophages (2.9 - 3.7, in control 0.8 - 1.3), fibroblasts (3.0 - 3.6, in control 2.7 - 2.8), vascular smooth muscle cells, vascular endothelial cells, and fibroblast-like cells surrounding pulmonary vessels (2.7 - 4.0, in control 2.1 - 2.9). In situ hybridization results were consistent with that of immunohistochemistry except that PDGF and TGF-beta mRNA transcripts were not detected in bronchio-alveolar epithelial cells. In control lungs, however, both ISH and IHC revealed that PDGF and TGF-beta were only present in the pleura and in fibroblast-like cells surrounding pulmonary vessels. CONCLUSIONS: PDGF and TGF-beta, which interplay with pulmonary mesenchymal cells, are involved in fibroplasia and deposition of extracellular matrix as well as angiogenesis and epithelial cell repopularization.

Becaplermin↗
PubMed1999

[Open lung biopsy in diagnosis of interstitial lung disease].

OBJECTIVE: To evaluate the role of open lung biopsy in diagnosis of interstitial lung disease. METHODS: 24 patients with interstitial lung disease who underwent open lung biopsy from 1993 to June 1998 were reviewed. RESULTS: The documented pathologic diagnosis in 24 patients with interstitial lung disease who underwent open lung biopsies were: 7 IPF (UIP), 1 acute interstitial pneumonia (AIP), 3 BOOP, 2 DPB, 3 sarcoidosis, 2 tuberculosis, 1 histiocytosis-X and 1 lung cancer. Most of these patients did not definitely diagnosed through their clinical evaluation including history, chest X-ray, pulmonary function tests and TBLB. CONCLUSIONS: Open lung biopsy, is a useful method, as it is sensitive and specific in diagnosis of interstitial lung disease. It is helpful in defining the site and extent of interstitial lung disease and diagnosing rare and atypical interstitial lung disease.

Adult↗
PubMed1999

[A clinical study of bacterial infection in patients with chronic obstructive pulmonary disease].

OBJECTIVE: To investigate the association of bacteriologic characteristics and bacterial infection in small airway disease. METHODS: Fiberoptic bronchoscopy and ultrathin fiberoptic bronchoscopy were performed on outpatients with COPD and chronic bronchitis both during stable stage and acute exacerbation. Samples were obtained from both large and small airways by protective specimen brush, and bacteria were cultured quantitatively. RESULTS: The positive rates for pathogens in patients with COPD and chronic bronchitis during acute exacerbation were 26.6% (8/30) and 23.5% (5/17) respectively. Major pathogens in acute COPD include Staphylococcus aureus, Streptococcus pneumoniae, Hemophilus influenzae, Moraxella catarrhalis, and Pseudomonas aeruginosa. All of the pathogens were present in large airways, with 2 strains present in small airways concurrently. The positive rates for pathogens in stable COPD and chronic bronchitis were 24.0% (6/24) and 11.7% (2/17) respectively. Major pathogens found in stable COPD include Staphylococcus epidermis, Micrococcus and Streptococcus pneumoniae. The bacteria were less than 10 x 10(3) cfu/ml, present mainly in large airways. There was no significant difference in the extent of small airway diseases between COPD with bacterial infection and that without bacterial infection (P > 0.05). CONCLUSIONS: Bacterial infection is not a major pathogenic factor in stable COPD. There is no direct cause-and-effect relationship between bacterial infection and the extent of small airway diseases in patients with COPD.

Adult↗
PubMed1999

[Effect of dietary arginine supplementation on wound healing and the relationship between dose and response in burn rats].

OBJECTIVE: To examine the dose-effect of dietary L-arginine supplementation on burn wound healing. METHODS: The effect of dietary L-arginine supplementation was studied in rats with deep thickness burn (10% TBSA). The time for epithelization of burn wound was determined. Photography of burn wound was taken for measuring percentage of burn wound healing area. Biopsies of burn wound were taken for measuring the content of hydroxyproline, the ratio between type I and type III collagen, and dermal cell cycle. RESULTS: Supplemental dietary L-arginine after burn in rats shortened the time for epithelization of burn wound, increased the content of hydroxyproline, decreased the ratio between type I and type III collagen, elevated the DNA content of dermis. Supplemental dietary L-arginine in the dose of 200 mg x kg(-1) x d(-1) was more effective than any other, 50 mg x kg(-1) x d(-1) and 800 mg kg(-1) x d(-1) showed no beneficial effect on the healing of burn wound. CONCLUSIONS: Suitable L-arginine supplementation can enhance burn wound healing in rats.

Animals↗
PubMed1999

[Phacoemulsification with foldable intraocular lens implantation through a limbus tunnel incision].

OBJECTIVE: To advance and evaluate the technique and therapeutic effects of phacoemulsification with foldable intraocular lens implantation through a limbus tunnel incision. METHODS: The surgery was performed through a 3.2 limbus tunnel incision on 110 eyes of 103 patients with senile, complicated, congenital and traumatic cataracts. RESULTS: Postoperatively, the visual acuities with spherical correction or without correction were 0.5 or better in 90.0% of the eyes at one day, and 1.0 or better in 42.5%, 63.7% and 68.0% at one week, one month and three months respectively. The mean postoperative astigmatism was (1.00 +/- 0.68) D at one week and only 0.07D more than the mean preoperative one (P > 0.05). There was also no statistical difference between the mean preoperative astigmatism and postoperative astigmatism at one and three months, which were respectively (0.91 +/- 0.55) D and (0.83 +/- 0.57) D. The mean postoperative astigmatism was almost the same as compared between the scleral tunnel incision and clear corneal incision groups. CONCLUSION: The phacoemulsification with foldable intraocular lens implantation through a limbus tunnel incision can reduce postoperative astigmatism and shorten the period of visual rehabilitation as the operation through a scleral tunnel or a clear corneal incision, and in the mean time the former method can overcome the shortages of the latter two methods.

Adolescent↗