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Biomedical subjects

Lin Zhang

Publications and source records attributed to Lin Zhang.

At least 145 records · Page 8Linked to original sources

A large high-density lipoprotein enriched in apolipoprotein C-I: a novel biochemical marker in infants of lower birth weight and younger gestational age.

CONTEXT: Low birth weight is associated with increased cardiovascular disease in adulthood, and differences in the molecular weight, composition, and quantity of lipoprotein subclasses are associated with coronary artery disease. OBJECTIVE: To determine if there are novel patterns of lipoprotein heterogeneity in low-birth-weight infants. DESIGN, SETTING, AND PARTICIPANTS: Prospective study at a US medical center of a representative sample of infants (n = 163; 70 white and 93 black) born at 28 or more weeks of gestational age between January 3, 2000, and September 27, 2000. This sample constituted 20% of all infants born during the study period at this site. MAIN OUTCOME MEASURES: Plasma levels and particle sizes of lipoprotein subclasses and plasma concentrations of lipids, lipoproteins (high-density lipoprotein [HDL] and low-density lipoprotein [LDL]), and apolipoproteins. RESULTS: An elevated lipoprotein peak of a particle with density between 1.062 and 1.072 g/mL was identified using physical-chemical methods. This subclass of large HDL was enriched in apolipoprotein C-I (apo C-I). Based on the amount of the apo C-I-enriched HDL peak, 156 infants were assigned to 1 of 4 groups: 0 (none detected), 17%; 1 (possibly present), 41%; 2 (probably present), 22%; 3 (elevated), 19%. Infants in group 3, compared with those in the other 3 groups, had significantly (P<.001) lower mean birth weight (2683.7 vs 3307.1 g) and younger mean gestational age (36.2 vs 39.3 wk). After correction for age, infants in group 3 had significantly higher levels of total and large HDL cholesterol and of total and large LDL cholesterol and LDL particle number. However, infants in group 3 had lower levels of small HDL, very low-density lipoproteins, and triglycerides than infants in the other 3 groups. This lipoprotein profile differed from that in infants born small for gestational age, who had significantly higher triglyceride (P<.001) and apo B (P = .04) levels, but lower levels of total and large HDL cholesterol (P<.001) and apo A-I (P<.001). CONCLUSIONS: Because apo C-I-enriched HDL, and purified apo C-I alone, promotes apoptosis in vitro, increased amounts of this particle may have physiological significance and identify a novel group of low-birth-weight infants apparently distinct from traditionally classified small-for-gestational-age infants.

Apolipoprotein C-I↗

L1 retrotransposon-mediated stable gene silencing.

RNA interference (RNAi) is widely used for functional studies and has been proposed as a potential therapeutic agent. Current RNAi systems are largely efficient, but have limitations including transient effect, the need for viral handling and potential insertional mutations. Here, we describe a simple L1 retrotransposon-based system for the delivery of small interfering RNA (siRNA) and stable silencing in human cells. This system demonstrated long-term siRNA expression and significant reduction in both exogenous and endogenous gene expression by up to 90%. Further characterization indicated that retrotransposition occurred in a controlled manner such that essentially only one RNAi-cassette was integrated into the host genome and was sufficient for strong interference. Our system provides a novel strategy for stable gene silencing that is easy and efficient, and it may have potential applications for ex vivo and in vivo molecular therapy.

Genetic Techniques↗

Incidence of atherosclerosis by race in the dialysis morbidity and mortality study: a sample of the US ESRD population.

White individuals who are on dialysis experience much higher overall and cardiovascular mortality rates than black individuals despite a more favorable risk factor profile, but the incidence of nonfatal cardiovascular disease (CVD) to this racial disparity has not been well studied. A longitudinal study of 16,103 people who had ESRD and were enrolled in the United Renal Data System from 1993 to 1996 was conducted. The incidence of new and recurrent atherosclerotic CVD (ASCVD) events was determined using Medicare claims for hospitalizations and mortality among blacks and whites, stratified by ASCVD at baseline. ASCVD was defined as coronary heart disease, peripheral vascular disease, and cerebrovascular disease. Incidence of new ASCVD in people without ASCVD at baseline was 146.9 per 1000 person-years in whites and 118.7 per 1000 person-years in blacks. Incidence of recurrent ASCVD was 404.1 per 1000 person-years in whites and 317.5 per 1000 person-years in blacks. Whites were 1.35 (95% confidence interval, 1.18 to 1.55) times more likely to develop incident ASCVD compared with blacks and 1.25 (95% confidence interval, 1.14 to 1.36) times more likely to develop recurrent disease after adjusting for traditional CVD and dialysis-related risk factors. Excess risk for recurrent ASCVD in whites compared with blacks was consistently present no matter the duration of dialysis: Hazard ratio 1.42 for 0 to 6 mo and 1.40 for 6 to 12 mo. Whites who are treated with dialysis have a higher incidence of ASCVD than blacks who are on dialysis, both new and recurrent. Although differences in survival before the initiation of dialysis may contribute to the observed difference in ASCVD risk, it is not explained by baseline traditional and dialysis-related ASCVD risk factors.

Aged↗

[Hand-assisted video-thoracoscopy for resection of esophageal cancer].

OBJECTIVE: To explore the feasibility and advantages of hand-assisted video-thoracoscopy for resection of esophageal cancer. METHODS: Forty-five patients with esophageal cancer received hand-assisted video-thoracoscopic esophagectomy (group I). 45 patients underwent esophagectomy through routine open thoracotomy during the same period as control (group II). The data of lymph node resection, operating time and blood loss were compared. RESULTS: There were no operative mortality in 2 groups. In group I, the number of dissected paraesophageal lymph nodes, cardiac lymph nodes and left gastric nodes were (3.6 +/- 1.0), (1.3 +/- 1.1) and (4.3 +/- 1.4), respectively. While for group II the dissected lymph nodes were (3.3 +/- 1.5), (1.6 +/- 1.1) and (4.7 +/- 2.1), respectively. There was no significant difference between two groups (P > 0.05). However, the number of dissected mediastinal nodes was (6.6 +/- 3.7) for group I and (3.8 +/- 2.5) for group II (chi(2) = 2.95, P < 0.05). The mean operating time was (29 +/- 5) minutes for group I and (60 +/- 6) minutes for group II. The mean blood loss was (93 +/- 19) ml for group I and (145 +/- 35) ml for group II. The mean chest tube drainage was (201 +/- 45) ml for group I and (295 +/- 57) ml for group II in the first postoperative day. The difference in above parameters between 2 groups was significant (chi(2) = 18.69, 6.13, 6.08, P < 0.001). CONCLUSIONS: It is suggested that hand-assisted video-thoracoscopic esophagectomy is a safer, minimal invasive procedure in the resection of esophagus carcinoma.

Adult↗

[The clinical significance of vascular endothelial growth factor and intercellular adhesion molecule-1 expression in non-small cell lung cancer].

OBJECTIVE: To investigate the expression of vascular endothelial growth factor (VEGF) and intercellular adhesion molecule-1 (ICAM-1), and their relationship to behaviors of the non-small-cell lung cancer. METHODS: The study included 86 patients with non-small-cell lung cancer. A rapid immunohistochemical method (streptoavidin-peroxidase, SP) was used to detect VEGF and ICAM-1 expression. All patients were treated surgically and without preoperative radio- or chemotherapy. RESULTS: The positive expression of VEGF was significantly correlated with the lymph node metastasis, TNM stage, prognosis and hematogenous tumor metastasis positively, but ICAM-1 was negatively. For patients with positive expression of VEGF and negative expression of ICAM-1, the 5-year survival rate was the lowest in all patients. CONCLUSIONS: The expression of VEGF and ICAM-1 correlates with the malignant behavior of non-small-cell lung cancer. Examination of VEGF and ICAM-1 in non-small-cell lung cancer may help to evaluate its intensity of lymph node metastasis, TNM stage and prognosis. VEGF and ICAM-1 may play an important role in the development and metastasis of non-small-cell lung cancer.

Adult↗

HISTONE DEACETYLASE19 is involved in jasmonic acid and ethylene signaling of pathogen response in Arabidopsis.

Histone acetylation is modulated through the action of histone acetyltransferases and deacetylases, which play key roles in the regulation of eukaryotic gene expression. Previously, we have identified a yeast histone deacetylase REDUCED POTASSIUM DEPENDENCY3 (RPD3) homolog, HISTONE DEACETYLASE19 (HDA19) (AtRPD3A), in Arabidopsis thaliana. Here, we report further study of the expression and function of HDA19. Analysis of Arabidopsis plants containing the HDA19:beta-glucuronidase fusion gene revealed that HDA19 was expressed throughout the life of the plant and in most plant organs examined. In addition, the expression of HDA19 was induced by wounding, the pathogen Alternaria brassicicola, and the plant hormones jasmonic acid and ethylene. Using green fluorescent protein fusion, we demonstrated that HDA19 accumulated in the nuclei of Arabidopsis cells. Overexpression of HDA19 in 35S:HDA19 plants decreased histone acetylation levels, whereas downregulation of HDA19 in HDA19-RNA interference (RNAi) plants increased histone acetylation levels. In comparison with wild-type plants, 35S:HDA19 transgenic plants had increased expression of ETHYLENE RESPONSE FACTOR1 and were more resistant to the pathogen A. brassicicola. The expression of jasmonic acid and ethylene regulated PATHOGENESIS-RELATED genes, Basic Chitinase and beta-1,3-Glucanase, was upregulated in 35S:HDA19 plants but downregulated in HDA19-RNAi plants. Our studies provide evidence that HDA19 may regulate gene expression involved in jasmonic acid and ethylene signaling of pathogen response in Arabidopsis.

Arabidopsis↗

Cloning and expression of MRG receptors in macaque, mouse, and human.

Members of the MRG family of G-protein coupled receptors (GPCRs) are expressed predominately in small diameter sensory neurons of the dorsal root ganglia (DRG) suggesting a possible role in nociception. However, the large expansion of this gene family in rodents, combined with the lack of strict rodent orthologs for many of the human MRG genes, limits the usefulness of rodent models to evaluate human MRG involvement in nociception. Furthermore, the high degree of similarity between related rodent Mrg genes suggests that pharmacological approaches to define the function of individual receptors will prove difficult. The creation of an animal model to examine human MRG function will, therefore, require the identification of human MRG orthologs in a non-rodent species. Here we report the identification of MRGD, MRGE, and several MRGX orthologs in the crab-eating macaque, Macaca fascicularis. Similar to their human counterparts, all isolated macaque genes were expressed in dorsal root ganglia neurons. In the case of macaque MrgX2 and MrgD, expression was co-localized with the known nociceptive neuronal markers, IB4, VR1, and SP. Although expression in DRG neurons was the prominent feature of this family, we also found that MrgE was expressed in numerous brain regions of macaque, mouse, and human.

Animals↗

Desmoglein genes are up-regulated in the pk mutant mouse.

Plucked (pk) is an autosomal recessive mouse mutation with a hair phenotype that arose spontaneously in the DBA/2J strain. Histological studies indicate that adult pk mutant mice lose truncal hair because of the scarring of follicles due to an apparent obstruction of the outward movement of the hair shaft within the follicular canal. We mapped the pk mutant phenotype to a 1.1cM region of chromosome 18 (between 6.6 and 7.7 cM from the centromere) using 370 backcross progeny. Within this region, among others, are genes for desmosome cadherins. Desmosome cadherins are interesting candidates because of their critical roles for cell-cell adhesion in epidermal function. Northern Blot analysis of wild-type and pk mutant mice indicates that expression of both desmoglein 1 (Dsg1) and desmoglein 3 (Dsg3) is up-regulated in the skin of mutant pk mice.

Animals↗

[Expression and clinical significance of MAPK in non-small cell lung cancer].

OBJECTIVE: To explore the expression of p38,ERK1 (extracellular signal regulated kinases1) and JNK1 (c-jun NH2-terminal kinases1), subtribes of MAPK (mitogen activated protein kinases), and their clinical implication in non-small cell lung cancer (NSCLC) cells. METHOD: Immunohistochemistry was used to detect the expression of p38, ERK1, JNK1, and ras in the resected specimens of non-small cell lung cancer from 73 patients. The relation between p38, ERK1, and JNK1 and clinicopathological factors were analyzed by Mann-Whitney u test, chi(2) test, and Fisher precise probability method. The relations between ras and various subtribes of MAPK were analyzed by chi(2) test; the post-operative clinical effects were detected by Kaplan-Meier curve. RESULTS: Expression of p38 was related with lymph node metastasis (P = 0.000) and TNM staging (P = 0.001). Expression of ERK1 was correlated with pathological type (P = 0.015), lymph node metastasis (P = 0.000) and TNM staging (P = 0.000). Expression of JNK1 was related with the tumor location (P = 0.005). ras expression was correlated with p38 (P = 0.003) and ERK1 (P = 0.012). Univariate analysis showed that TNM staging (P = 0.0000), lymph node metastasis (P = 0.0000), tumor differentiation (P = 0.0000), p38 (P = 0.0001), JNK1 (P = 0.0232), and ras (P = 0.0022) were of prognostic significance. Multivariable analysis showed that NSCLC patients with negative expression of p38 (P = 0.035), clinical I stage (P = 0.026), negative lymph node metastasis (P = 0.044) and fine tumor differentiation (P = 0.020) might have a better prognosis. CONCLUSION: Among the subtribes of MAPK, p38 may be of use to assess lymph node metastasis and TNM staging, ERK1 may be of use to evaluate histological type, lymph node metastasis and TNM staging, and JNK1 to assess the tumor location. ras may increase the expression of p38 and ERK1. p38, as well as some clinicpathological factors, including TNM staging, lymph node metastasis and tumor differentiation are prognostic factors of NSCLC.

Aged↗

Transcriptional coactivator Drosophila eyes absent homologue 2 is up-regulated in epithelial ovarian cancer and promotes tumor growth.

Epithelial ovarian cancer is the most frequent cause of gynecologic malignancy-related mortality in women. To identify genes up-regulated in ovarian cancer, PCR-select cDNA subtraction was done and Drosophila Eyes Absent Homologue 2 (EYA2) was isolated as a promising candidate. The transcriptional coactivator eya controls essential cellular functions during organogenesis of Drosophila. EYA2 mRNA was found to be up-regulated in ovarian cancer by real-time reverse transcription-PCR, whereas its protein product was detected in 93.6% of ovarian cancer specimens by immunohistochemistry (n = 140). EYA2 was amplified in 14.8% of ovarian carcinomas, as detected by array-based comparative genomic hybridization (n = 88). Most importantly, EYA2 overexpression was significantly associated with short overall survival in advanced ovarian cancer (n = 99, P = 0.0361). EYA2 was found to function as transcriptional activator in ovarian cancer cells by Gal4 assay and to promote tumor growth in vivo in xenograft models. Therefore, this study suggests an important role of EYA2 in ovarian cancer and its potential application as a therapeutic target.

Animals↗

A highly electroluminescent molecular square.

Chiral molecular triangles and squares containing the Pt(diimine) metallocorners were synthesized and characterized, and used as the triplet MLCT luminophore in highly efficient light-emitting devices.

Journal Article↗

Simultaneous measurement of temperature and external refractive index by use of a hybrid grating in D fiber with enhanced sensitivity by HF etching.

We propose a dual-parameter optical sensor device achieved by UV inscription of a hybrid long-period grating-fiber Bragg grating structure in D fiber. The hybrid configuration permits the detection of the temperature from the latter's response and measurement of the external refractive index from the former's response. In addition, the host D fiber permits effective modification of the device's sensitivity by cladding etching. The grating sensor has been used to measure the concentrations of aqueous sugar solutions, demonstrating its potential capability to detect concentration changes as small as 0.01%.

Journal Article↗

Enhancement of enzyme activity and enantioselectivity by cyclopentyl methyl ether in the transesterification catalyzed by Pseudomonas cepacia lipase co-lyophilized with cyclodextrins.

The solvent effects of cyclopentyl methyl ether (CPME) on the reaction rates and enzyme enantioselectivity in the enantioselective transesterifications of racemic 6-methyl-5-hepten-2-ol (racemic sulcatol: SUL) and racemic 2,2-dimethyl-1,3-dioxolane-4-methanol (racemic solketal: SOL) with a series of enol esters catalyzed by Pseudomonas cepacia lipase co-lyophilized with cyclodextrins (alpha-, beta-, gamma-, partially methylated beta-, and 2,3,6-tri-O-methyl-beta-cyclodextrin: alphaCyD; betaCyD; gammaCyD; Me1.78betaCyD; Me3betaCyD) were investigated and compared with those in diisopropyl ether (IPE). In the case of SUL, enzyme activities of the co-lyophilizate with Me1.78betaCyD in CPME were lower than those in IPE with every acyl source, however, the absolute enantiopreference was shown in the transesterification with vinyl butyrate (VBR) in IPME. When the substrates were SOL and VBR, the enzyme activities in CPME were greatly enhanced as high as 1.6-9.8-fold, while the enantioselectivities in CPME were comparable to those in IPE.

Biochemistry↗

The immunophilin ligand FK506 protects against methamphetamine-induced dopaminergic neurotoxicity in mouse striatum.

Repeated use of methamphetamine (MAP) is known to cause neurotoxicity in the dopaminergic neurons of the striatum. Recently, we reported that FK506, a calcineurin inhibitor and immunosuppressive agent, could attenuate acute behavioral changes and the development of sensitization after administration of MAP. In this study, we investigated the effects of FK506 on the neurotoxicity in the dopaminergic neurons induced by repeated administration of MAP. BALB/c mice were injected subcutaneously (s.c.) with vehicle (10 ml/kg) or MAP (4 mg/kg) four times every 2h. Vehicle (10 ml/kg) or FK506 (0.1, 0.3, 1 or 3 mg/kg i.p.) was administered 15 min before the first MAP administration. Three days later, we assessed the contents of dopamine (DA) and its major metabolite, 3,4-dihydroxyphenylacetic acid (DOPAC), in the mouse striatum using high-performance liquid chromatography (HPLC). We also examined the immunohistochemistry of dopamine transporter (DAT) and tyrosine hydroxylase (TH) in the mouse brain. Repeated administration of MAP decreased significantly the contents of DA and DOPAC in the mouse striatum, and pretreatment with FK506 inhibited significantly the reduction of DA and DOPAC in the mouse brain by repeated administration of MAP. Furthermore, repeated administration of MAP decreased significantly the immunoreactivity of DAT and TH in the striatum as compared to controls. Pretreatment with FK506 (3 mg/kg) attenuated significantly the reduction of DAT and TH immunoreactivity after repeated administration of MAP. These results suggest that FK506 shows protective effects on the MAP-induced neurotoxicity in the dopaminergic neurons of the mouse striatum.

Animals↗

Serum brain-derived neurotrophic factor (BDNF) levels in patients with panic disorder: as a biological predictor of response to group cognitive behavioral therapy.

Little is known about biological predictors of treatment response in panic disorder. Our previous studies show that the brain-derived neurotrophic factor (BDNF) may play a role in the pathophysiology of major depressive disorders and eating disorders. Assuming that BDNF may be implicated in the putative common etiologies of depression and anxiety, the authors examined serum BDNF levels of the patients with panic disorder, and its correlation with therapeutic response to group cognitive behavioral therapy (CBT). Group CBT (10 consecutive 1 h weekly sessions) was administered to the patients with panic disorder after consulting the panic outpatient special service. Before treatment, serum concentrations of BDNF and total cholesterol were measured. After treatment, we defined response to therapy as a 40% reduction from baseline on Panic Disorder Severity Scale (PDSS) score as described by [Barlow, D.H., Gorman, J.M., Shear, M.K., Woods, S.W., 2000. Cognitive-behavioral therapy, imipramine, or their combination for panic disorder: A randomized controlled trial. JAMA. 283, 2529-2536]. There were 26 good responders and 16 poor responders. 31 age- and sex-matched healthy normal control subjects were also recruited in this study. The serum BDNF levels of the patients with poor response (25.9 ng/ml [S.D. 8.7]) were significantly lower than those of the patients with good response (33.7 ng/ml [S.D. 7.5]). However, there were no significant differences in both groups of the patients, compared to the normal controls (29.1 ng/ml [S.D. 7.1]). No significant differences of other variables including total cholesterol levels before treatment were detected between good responders and poor responders. These results suggested that BDNF might contribute to therapeutic response of panic disorder. A potential link between an increased risk of secondary depression and BDNF remains to be investigated in the future.

Adult↗

No association of the brain-derived neurotrophic factor (BDNF) gene polymorphisms with panic disorder.

Several lines of evidence suggest that genetic factors might contribute to susceptibility to panic disorder. Our previous studies show that the brain-derived neurotrophic factor (BDNF) may play a role in the pathophysiology of major depressive disorders and eating disorders. Assuming that BDNF may be implicated in the putative common pathophysiology of depression and anxiety, we analyzed the association of two BDNF gene single nucleotide polymorphisms (SNPs), 132C > T (formerly named C270T) in the noncoding region of exon V and 196G > A (val66met) in the coding region of exon XIIIA, with panic disorder. In this study, 109 patients with panic disorder diagnosed according to the DSM-IV criteria, and 178 control subjects were recruited. There were no significant differences in the frequency of the genotype or allele in these two SNPs between patients and controls [132C > T in exon V: genotype, p = 1.0, allele, p = 0.59; 196G > A (val66met) in exon XIIIA: genotype, p = 0.77, allele, p = 0.78]. Furthermore, no significant associations of agoraphobia with the two SNPs were detected. This study suggests that the BDNF gene polymorphisms are not associated with panic disorder in our Japanese population.

Adult↗

Glycaemia (haemoglobin A1c) and incident ischaemic stroke: the Atherosclerosis Risk in Communities (ARIC) Study.

BACKGROUND: Individuals with diabetes have a raised risk of stroke, but it is unclear whether sustained hyperglycaemia contributes to the development of cerebrovascular disease. Haemoglobin A1c (HbA(1c)), a measure of long-term glycaemia, is strongly related to retinopathy, nephropathy, and neuropathy in diabetes. We sought to assess the association between HbA(1c) and stroke in people with and without diabetes. METHODS: 10,886 participants without diabetes and 1635 participants with diabetes in the ARIC study, who did not have cardiovascular disease, were followed up for incident ischaemic stroke over 8-10 years. We assayed HbA(1c) for all 167 stroke cases and a sample of 680 non-cases in the adults without diabetes and for the full cohort of 1635 adults with diabetes (including 89 stroke cases). We assessed the relation between HbA(1c) concentrations (in tertiles specific for individuals with and without diabetes) and incident ischaemic stroke during follow-up using Cox proportional hazards models, controlling for risk factors for stroke. FINDINGS: The adjusted relative risks of stroke increased with increasing tertile of HbA1c in both adults without diabetes (p=0.02) and with diabetes (p<0.0001). Compared with adults without diabetes in the lowest tertile of HbA1c, the adjusted relative risks of stroke by HbA(1c) tertile were 1.18 (0.70-2.00) and 1.58 (0.94-2.66) in adults without diabetes and 1.75 (0.90-3.42), 2.29 (1.24-4.21), and 4.71 (2.69-8.25) in adults with diabetes. INTERPRETATION: Raised HbA(1c) could be an independent risk factor for stroke in people with and without diabetes, with relative risks similar to those previously reported for coronary heart disease.

Atherosclerosis↗

Influence of ambient (outdoor) sources on residential indoor and personal PM2.5 concentrations: analyses of RIOPA data.

The Relationship of Indoor, Outdoor and Personal Air (RIOPA) study was designed to investigate residential indoor, outdoor and personal exposures to several classes of air pollutants, including volatile organic compounds, carbonyls and fine particles (PM2.5). Samples were collected from summer, 1999 to spring, 2001 in Houston (TX), Los Angeles (CA) and Elizabeth (NJ). Indoor, outdoor and personal PM2.5 samples were collected at 212 nonsmoking residences, 162 of which were sampled twice. Some homes were chosen due to close proximity to ambient sources of one or more target analytes, while others were farther from sources. Median indoor, outdoor and personal PM2.5 mass concentrations for these three sites were 14.4, 15.5 and 31.4 microg/m3, respectively. The contributions of ambient (outdoor) and nonambient sources to indoor and personal concentrations were quantified using a single compartment box model with measured air exchange rate and a random component superposition (RCS) statistical model. The median contribution of ambient sources to indoor PM2.5 concentrations using the mass balance approach was estimated to be 56% for all study homes (63%, 52% and 33% for California, New Jersey and Texas study homes, respectively). Reasonable variations in model assumptions alter median ambient contributions by less than 20%. The mean of the distribution of ambient contributions across study homes agreed well for the mass balance and RCS models, but the distribution was somewhat broader when calculated using the mass balance model with measured air exchange rates.

Air Pollutants↗