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Biomedical subjects

N Zhang

Publications and source records attributed to N Zhang.

At least 91 records · Page 5Linked to original sources
PubMed2000

Intensive care unit telemedicine: alternate paradigm for providing continuous intensivist care.

OBJECTIVE: Intensive care units (ICUs) account for an increasing percentage of hospital admissions and resource consumption. Adverse events are common in ICU patients and contribute to high mortality rates and costs. Although evidence demonstrates reduced complications and mortality when intensivists manage ICU patients, a dramatic national shortage of these specialists precludes most hospitals from implementing an around-the-clock, on-site intensivist care model. Alternate strategies are needed to bring expertise and proactive, continuous care to the critically ill. We evaluated the feasibility of using telemedicine as a means of achieving 24-hr intensivist oversight and improved clinical outcomes. DESIGN: Observational time series triple cohort study. SETTING: A ten-bed surgical ICU in an academic-affiliated community hospital. PATIENTS: All patients whose entire ICU stay occurred within the study periods. INTERVENTIONS: A 16-wk program of continuous intensivist oversight was instituted in a surgical ICU, where before the intervention, intensivist consultation was available but there were no on-site intensivists. Intensivists provided management during the intervention using remote monitoring methodologies (video conferencing and computer-based data transmission) to obtain clinical information and to communicate with on-site personnel. To assess the benefit of the remote management program, clinical and economic performance during the intervention were compared with two 16-wk periods within the year before the intervention. MEASUREMENTS AND MAIN RESULTS: ICU and hospital mortality (observed and Acute Physiology and Chronic Health Evaluation III, severity-adjusted), ICU complications, ICU and hospital length-of-stay, and ICU and hospital costs were measured during the 3 study periods. Severity-adjusted ICU mortality decreased during the intervention period by 68% and 46%, compared with baseline periods one and two, respectively. Severity-adjusted hospital mortality decreased by 33% and 30%, and the incidence of ICU complications was decreased by 44% and 50%. ICU length of stay decreased by 34% and 30%, and ICU costs decreased by 33% and 36%, respectively. The cost savings were associated with a lower incidence of complications. CONCLUSIONS: Technology-enabled remote care can be used to provide continuous ICU patient management and to achieve improved clinical and economic outcomes. This intervention's success suggests that remote care programs may provide a means of improving quality of care and reducing costs when on-site intensivist coverage is not available.

APACHE↗
PubMed2000

Simple and inexpensive but highly discriminating method for computer-assisted DNA fingerprinting of Pseudomonas aeruginosa.

We describe here a method for computer-assisted fingerprinting of Pseudomonas aeruginosa. In this method, DNA is digested with SalI, and bands with molecular sizes of >/=9.7 kb are visually scored after electrophoresis on agarose gels. Pattern scores are entered into a Microsoft Excel database. In scoring, the number of bands within each of a set of molecular size ranges is scored, rather than the absolute molecular size of each band, substantially enhancing the speed and reproducibility of the method, while eliminating the need for using expensive gel scanning equipment and software. Pattern scores are used to generate matrices of genetic distance values, which can be visualized in neighbor-joining trees. The method reliably distinguishes two epidemiologically unrelated isolates in 99.3% of all comparisons. The genetic relationships between isolates observed with the method were consistent with those obtained by analysis of two P. aeruginosa genes, indicating that it provides valid estimates of genetic divergence between isolates. Using the method, respiratory tract isolates from cystic fibrosis patients in Green Lane Hospital in Auckland, New Zealand, were shown to be genetically less diverse than epidemiologically unrelated isolates from other patients. This finding was not due to the existence of clusters of related strains specialized toward colonization of the respiratory tract and thus was indicative of transmission between patients. Analysis of multiple isolates from individual cystic fibrosis patients suggested that up to five separate clusters of genetically related strains may simultaneously be present in a patient. The method described should significantly enhance our ability to investigate the epidemiology of P. aeruginosa.

Bacterial Outer Membrane Proteins↗
PubMed2000

Gamma Knife radiosurgery as a primary surgical treatment for hypersecreting pituitary adenomas.

OBJECT: To estimate the efficacy of Gamma Knife radiosurgery (GKR) especially as a primary surgical treatment for hypersecreting pituitary adenomas. METHODS: 274 patients were treated with GKR. The mean tumor volume was 1.86 cm(3). The mean peripheral dose was 28.7 Gy. RESULTS: 223 patients were followed up for an average of 31.6 months. The dose related to the tumor growth control and endocrinological normalization was detailed and statistical analysis of the data was performed. CONCLUSION: GKR as a primary surgical treatment for hypersecreting pituitary adenomas may be safe and effective.

Adenoma↗
PubMed2000

Gamma knife radiosurgery as a primary treatment for prolactinomas.

OBJECT: The purpose of this study was to estimate the efficacy of gamma knife radiosurgery (GKS) in controlling tumor growth and endocrinopathy associated with prolactinomas. METHODS: Between 1993 and 1997, 164 of 469 patients with pituitary adenomas treated by GKS harbored prolactinomas. The dose to the tumor margin ranged from 9 to 35 Gy (mean 31.2 Gy), and the visual pathways were exposed to a dose of less than 10 Gy. The mean tumor diameter was 13.4 mm. The mean follow-up time for 128 cases was 33.2 months (range 6-72 months). Tumor control was observed in all but two patients who underwent surgery 18 and 36 months, respectively, after GKS. Clinical cure was achieved in 67 cases. Clinical improvement was noted with a decrease in the hyperprolactinemia after GKS. Nonetheless, in 31 (29%) of 108 patients who were followed for more than 2 years no improvement in serum prolactin levels was demonstrated, although this could be normalized by bromocriptine administration after treatment. Nine infertile women became pregnant 2 to 13 months after GKS and all gave birth to normal children. There was no visual deterioration related to GKS. Five women experienced premature menopause. In these patients there was subtotal disappearance of the tumor and an empty sella developed. CONCLUSIONS: Gamma knife radiosurgery as a primary treatment for prolactinomas can be safe and effective both for controlling tumor growth and for normalization of prolactin hypersecretion. A higher margin dose (> or = 30 Gy) seemed to be associated with a better clinical outcome. Gamma knife radiosurgery may make prolactinomas more sensitive to the bromocriptine.

Humans↗
PubMed2000

The ties that bind what is known to the recall of what is new.

Cued recall success varies with what people know and with what they do during an episode. This paper focuses on prior knowledge and disentangles the relative effects of 10 features of words and their relationships on cued recall. Results are reported for correlational and multiple regression analyses of data obtained from free association norms and from 29 experiments. The 10 features were only weakly correlated with each other in the norms and, with notable exceptions, in the experiments. The regression analysis indicated that forward cue-to-target strength explained the most variance, followed by backward target-to-cue strength. Target connectivity and set size explained the next most variance, along with mediated cue-to-target strength. Finally, frequency, concreteness, shared associate strength, and cue set size also contributed significantly to recall. Taken together, indices of prior word knowledge explain 49% of the recall variance. Theoretically driven equations that use free association to predict cued recall were also evaluated. Each equation was designed to condense multiple indices of word interconnectivity into a single predictor.

Adult↗
PubMed2000

The effect of HMOs on hospital capacity, 1982-1996.

Hospital capacity has declined in recent years and is forecast to decline further. The objective of this study is to determine if hospital capacity has declined more rapidly in metropolitan statistical areas (MSAs) with high HMO market penetration compared with MSAs with low HMO market penetration in the period from 1982 to 1996. The findings presented in this study are that greater reductions in beds per capita occur in MSAs with greater HMO penetration, but the magnitude of the differences is small. Reductions in other measures of hospital capacity--hospital closures, beds per hospital, and occupancy--are not consistently associated with HMO market penetration. Bed capacity occurs at roughly similar rates in all MSAs.

Analysis of Variance↗
PubMed2000

Biological function of a novel gene overexpressed in human hepatocellular carcinoma.

OBJECTIVE: To clone the full-length of a differentially expressed cDNA fragment, LC27, and study its biological function tentatively. METHODS: Northern blot was used to analyze the expression pattern of LC27 in hepatocellular carcinoma, matched nontumor liver tissues, fetal liver and normal adult liver tissues, as well as BEL-7402 hepatocellular carcinoma cell line ESTs splicing and 5' rapid amplification of cDNA ends (5' RACE) were used to clone the full-length of LC27 cDNA. An antisense oligodeoxynucleotide approach was used to investigate the biological role of the gene in the proliferation of BEL-7402 cells. RESULTS: A 2186 bp novel cDNA with an open reading frame encoding a 283 amino acid protein was cloned. Analysis of the deduced amino acid sequence indicated that it is 38% (88/229) identical to human Golgi 4-transmembrane spanning transporter MTP. The gene and the encoded protein was termed hepatocellular carcinoma overexpressed transmembrane protein (hotp) and HOTP, respectively. Hotp mRNA was almost undetectable in normal adult liver and fetal liver tissues. However, it was significantly up-regulated in hepatocellular carcinoma and some matched nontumor liver tissues, as well as BEL-7402 cells. The proliferation of BEL-7402 cells was suppressed by an antisense oligodeoxynucleotide against hotp mRNA at a concentration of 50 micrograms/ml. CONCLUSION: HOTP may be an integral membrane transporter protein. The overexpression of the gene in hepatocellular carcinoma may play an important role in hepatocarcinogenesis and disease progression.

Adult↗
PubMed2000

Effect of superantigen on ion electrophysiology and permeability in rabbit maxillary sinus epithelia.

OBJECTIVE: Superantigens are potent inflammatory stimuli which derive from pathogenic microbes such as bacteria, viruses and protozoa. The aim of this study was to investigate the role of superantigens on the function of rabbit maxillary sinus epithelium. METHODS: Twenty New Zealand white rabbits were divided into 4 groups. Rabbit sinus mucosa was separated under a surgical microscope and mounted in Ussing chambers to record short circuit current, conductance and permeability to horseradish peroxidase (HRP). Group A was used as normal control. Group B was stimulated with an injection of superantigen into the sinus for 4 hours. The sinus mucosa of Group C was stimulated by the addition of tumor necrosis factor alpha (TNF-alpha) into Ussing chambers. Group D sinus mucosa was stimulated by superantigen after pretreatment with anti-TNF-alpha antibody. RESULTS: Superantigen evoked increases in sinus epithelial cell baseline short circuit current, conductance and permeability to HRP stimulated by the addition of TNF-alpha into Ussing chambers. These were similar to results from superantigen stimulation in vivo. The effect of superantigen on sinus epithelial cells could be blocked by pretreatment with anti-TNF-alpha antibody. CONCLUSIONS: Superantigen affected the function of sinus epithelial cells, including the capability of epithelial defensive barrier, which might be mediated by TNF-alpha.

Animals↗
PubMed2000

[Genetic polymorphisms of Rb and susceptibility of esophageal cancer].

OBJECTIVE: To assess the possible association between the polymorphisms of Rb (intron 20, 17) and susceptibility of esophageal cancer so as to provide clues for genetic markers of esophageal cancer. METHODS: Samples were taken from 56 normal Han people of Shaanxi, 47 esophageal cancer samples, and 31 peri-cancerous non-tumor. DNAs were analysed by using PCR technique. RESULTS: Ten alleles fragments were found in Han population of Shannxi by using primer Rb gene (intron 20). PIC was 0.86. Heterozygosity was 0.7. In esophageal cancer tissues, PIC was 0.82. Heterozygosity was 0.55. In peri-cancerous non-tumor, PIC was 0.87. Heterozygosity was 0.74. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer (P < 0.01). Two alleles (945 bp, 630 bp + 315 bp) fragments were found in Han population of Shaanxi by using primer Rb gene (intron 17). Genotype frequency of Han population of Shaanxi was A/A: 0.28, A/B: 0.52, B/B: 0.20. Genotype frequency of esophageal cancer was A/A: 0.11, A/B: 0.77, B/B: 0.12. Distribution of genotype frequency was significantly different between Han population of Shaanxi and esophageal cancer (P < 0.05). Mutation of Rb gene was found in 7 cases. CONCLUSIONS: Polymorphism of Rb (intron 20) VNTR and Rb (intron 17) could be used as valuable markers. There should bea relationship between polymorphism of Rb VNTR and esophageal cancer susceptibility.

Esophageal Neoplasms↗
PubMed2000

[Diagnosis and treatment of thoracic myelopathy due to degenerative thoracic spine disease].

OBJECTIVE: To summarize the experience in the early diagnosis and treatment of chronic thoracic myelopathy due to the compression of degenerative thoracic spine disease. METHODS: 21 patients with thoracic spinal stenosis were operated on from January 1995 to April 2000. Etiologically 16 patients were found to have ossification of the ligamentum flovum, 3 Scheuermann's disease, and 2 DISH. They were confirmed by CT, CTM, MRI and Magnetic MEP. Decompression was performed by en block unroof laminectomy for the posterolateral wall of the thoracic canal. The epstein criteria were used to judge the operative results. RESULTS: In the 21 patients 5 belonged to localized type, 10 continuous type, and 3 skip type in 21 cases. Three patients showed a compression from the anterior side, and 3 were complicated by OPLL of the cervical spine. Results were excellent in 4 patients, good in 8, improved in 2, and poor in 1. One patient was operated on two times because the extent of laminectomy was not enough for the first operation. CONCLUSIONS: Early diagnosis can be made if orthopedists are familiar with the clinical characteristics of thoracic myelopathy, and are alert to thoracic spine stenosis. En block unroof laminectomy is effective and safe to treat thoracic spine stenosis.

Adult↗
PubMed2000

[The effect of TGF-beta1 on the expression of plasminogen activator inhibitors 1 and matrix metalloproteinases in cultured rat mesangial cells transfected with antisense-TGF-beta1 vector].

OBJECTIVE: To study the plasminogen activator inhibitors 1 (PAI-1) and matrix metalloproteinases (MMPs) expression on the cultured rat mesangial cells (MsC) transfected with antisense-TGF-beta1 vector. METHODS: Lipofectin method was used to transfect antisense-TGF-beta1 vector into MsC, Western blot and Northern blot analysis for detecting TGF-beta1 peptides and antisense TGF-beta1 RNA level. The expression of PAI-1 and MMPs were determined by Northern blot, Western bolt and zymography assay. RESULTS: The MsC clone (MAT1) which blocked the expression of TGF-beta1 peptides was successfully established. The MsC clone showed increased expression of MMP-2 mRNA protein and enzyme activity of MMP-2, 3, 7. However, expression of PAI-1 mRNA of MsC clone was suppressed. CONCLUSION: Blocked expression of TGF-beta1 can upregulate the expression of MMP-2, 3, 7 and downregulate the expression of PAI-1 mRNA in MsC. It is possible that antisense-TGF-beta1 may be used for gene therapy in glomerular diseases.

Animals↗
PubMed2000

[Mobilization of autologous peripheral blood stem cells by chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF) and granulocyte-macrophage colony-stimulating factor (GM-CSF)].

OBJECTIVE: To observe the efficacy of chemotherapy and recombinant granulocyte colony-stimulating factor (G-CSF, Glycosylated) and granulocyte-macrophage colony-stimulating factor (GM-CSF) in autologous peripheral blood stem cells (APBSC) mobilization. METHODS: The mobilization regimen: CBP 350 mg/m(2) intravenously injected at day 1, Vp16 350 mg/m(2) intravenously injected from day 1 to day 3. G-CSF and GM-CSF 5 microg x kg(-1) x d(-1) each, subcutaneously injected and DXM 5 mg/d intramuscularly injected, from the day of white blood cell (WBC) recovery to (2.4 - 6.4) x 10(9)/L from nadir to the day before the end of APBSC harvesting. APBSC harvesting started when WBC > 20.0 x 10(9)/L and ended when accumulated mononuclear cells (MNC) > 5 x 10(8)/kg. CFU-GM assay and CD(34)(+) cells counting of the APBSC were performed. RESULTS: Twenty cases underwent APBSC mobilization. APBSC harvest began at day 22.15 +/- 3.66 for two successive days. Accumulated MNC was (5.93 +/- 1.62) x 10(8)/kg, CD(34)(+) cells (23.10 +/- 11.53) x 10(6)/kg and CFU-GM (3.44 +/- 2.85) x 10(5)/kg. No severe toxicity was observed. Hematopoiesis was well reconstituted in 8 patients received single and in 1 patient received double APBSC transplantations. CONCLUSION: Chemotherapy combined with G-CSF + GM-CSF was a safe and highly effective method for APBSC mobilization.

Adult↗
PubMed2000

[The clinical observation of microsurgery treatment in early glottic carcinomas].

OBJECTIVE: To improve the life quality of the patients with T1 glottic carcinomas, and obtain good vocal effect. METHODS: Twenty-two patients under shoring laryngoscope and microscope were operated by surgery and laser. The phonetic parameters and vocal cord states of preoperative and postoperative patients were evaluated and analyzed objectively. RESULTS: The three-year relapse rate was 9.0% (2/22), and the survival rate of three-year, four-year, five-year were 100%, 94.7%, 93.3% respectively. The postoperative phonetic quality was improved. CONCLUSION: Patients with early glottis carcinomas could be treated by microsurgery. The damage of normal tissue might be reduced, and the patient's life quality has been improved. This method should be used widely in clinic.

Adult↗
PubMed1999

Regulation of the biosynthesis of N-acetylglucosaminylpyrophosphoryldolichol, feedback and product inhibition.

The assembly of the core oligosaccharide region of asparagine-linked glycoproteins proceeds by means of the dolichol pathway. The first step of this pathway, the reaction of dolichol phosphate with UDP-GlcNAc to form N-acetylglucosaminylpyrophosphoryldolichol (GlcNAc-P-P-dolichol), is under investigation as a possible site of metabolic regulation. This report describes feedback inhibition of this reaction by the second intermediate of the pathway, N-acetylglucosaminyl-N-acetylglucosaminylpyrophosphoryldolichol (GlcNAc-GlcNAc-P-P-dolichol), and product inhibition by GlcNAc-P-P-dolichol itself. These influences were revealed when the reactions were carried out in the presence of showdomycin, a nucleoside antibiotic, present at concentrations that block the de novo formation of GlcNAc-GlcNAc-P-P-dolichol but not that of GlcNAc-P-P-dolichol. The apparent K(i) values for GlcNAc-P-P-dolichol and GlcNAc-GlcNAc-P-P-dolichol under basal conditions were 4.4 and 2.8 microM, respectively. Inhibition was also observed under conditions where mannosyl-P-dolichol (Man-P-dol) stimulated the biosynthesis of GlcNAc-P-P-dolichol; the apparent K(i) values for GlcNAc-P-P-dolichol and GlcNAc-GlcNAc-P-P-dolichol were 2.2 and 11 microM, respectively. Kinetic analysis of the types of inhibition indicated competitive inhibition by GlcNAc-P-P-dolichol toward the substrate UDP-GlcNAc and non-competitive inhibition toward dolichol phosphate. Inhibition by GlcNAc-GlcNAc-P-P-dolichol was uncompetitive toward UDP-GlcNAc and competitive toward dolichol phosphate. A model is presented for the kinetic mechanism of the synthesis of GlcNAc-P-P-dolichol. GlcNAc-P-P-dolichol also exerts a stimulatory effect on the biosynthesis of Man-P-dol, i.e. a reciprocal relationship to that previously observed between these two intermediates of the dolichol pathway. This network of inhibitory and stimulatory influences may be aspects of metabolic control of the pathway and thus of glycoprotein biosynthesis in general.

Acetylglucosamine↗
PubMed1999

Identification of seven serotypes of bluetongue virus from the People's Republic of China.

Seven serotypes (1, 2, 3, 4, 12, 15 and 16) of bluetongue virus were isolated from the blood of sheep and cattle in the People's Republic of China between 1986 and 1996. Six of these viruses were isolated in Yunnan province. The sheep from which serotypes 1 and 16 were isolated showed obvious signs of bluetongue disease, whereas the cattle from which serotypes 2, 3, 4, 12 and 15 were isolated were clinically normal. Phylogenetic analyses of these viruses indicate that they are more closely related to one another, and to an Australian strain of serotype 1, than they are to prototype strains of bluetongue virus serotypes 2, 10, 11, 13 and 17 from the USA.

Animals↗