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Biomedical subjects

H Zhang

Publications and source records attributed to H Zhang.

At least 397 records · Page 22Linked to original sources
PubMed2001

Socioeconomic status and type 2 diabetes in African American and non-Hispanic white women and men: evidence from the Third National Health and Nutrition Examination Survey.

OBJECTIVES: This study examined the associations of poverty income ratio (PIR), education, and occupational status with type 2 diabetes prevalence among African American and non-Hispanic White (White) women and men aged 40 to 74 years. METHODS: We analyzed cross-sectional data from the Third National Health and Nutrition Examination Survey, controlling for age and examination-related variables. RESULTS: Among African American women, there was a strong, graded association between PIR and diabetes, which remained significant after other risk factors were adjusted for. All 3 variables were significantly associated with diabetes among White women. Among White men, only PIR was significantly associated with diabetes. Controlling for risk factors substantially attenuated these associations among White women. There were no significant associations for African American men. CONCLUSIONS: Socioeconomic status is associated with type 2 diabetes prevalence among women, but not consistently among men. Diabetes prevalence is more strongly associated with PIR than with education or occupational status. These associations are largely independent of other risk factors, especially among African American women. Economic resources should be addressed in efforts to explain and reverse the increasing prevalence of diabetes in the United States.

Adult↗
PubMed2001

Cost-effectiveness of earlier initiation of antiretroviral therapy for uninsured HIV-infected adults.

OBJECTIVES: This study was designed to examine the societal cost-effectiveness and the impact on government payers of earlier initiation of antiretroviral therapy for uninsured HIV-infected adults. METHODS: A state-transition simulation model of HIV disease was used. Data were derived from the Multicenter AIDS Cohort Study, published randomized trials, and medical care cost estimates for all government payers and for Massachusetts, NewYork, and Florida. RESULTS: Quality-adjusted life expectancy increased from 7.64 years with therapy initiated at 200 CD4 cells/microL to 8.21 years with therapy initiated at 500 CD4 cells/microL. Initiating therapy at 500 CD4/microL was a more efficient use of resources than initiating therapy at 200 CD4/microL and had an incremental cost-effectiveness ratio of $17,300 per quality-adjusted life-year gained, compared with no therapy. Costs to state payers in the first 5 years ranged from $5,500 to $24,900 because of differences among the states in the availability of federal funds forAIDS drug assistance programs. CONCLUSIONS: Antiretroviral therapy initiated at 500 CD4 cells/microL is cost-effective from a societal: perspective compared with therapy initiated later. States should consider Medicaid waivers to expand access to early therapy.

Anti-HIV Agents↗
PubMed2001

Thermal sensitivity in Tourette syndrome: preliminary report.

The effects of heat on tic symptoms were studied in a sample of 78 adults with Tourette syndrome. 62 men and 16 women completed a survey concerning the type, onset, and course of their tics. 10 adult male subjects also participated in a thermal challenge during which ambient temperature was raised from 22 degrees C to 35 degrees C following a control period. Of the 78, 24% or 19 reported increased tics upon exposure to heat. Compared to the remaining 59 subjects, there were no differences in sex distribution, current age, or overall course of illness. In the thermal challenge, there was general increase in tics that was correlated with sweat rate (r = .55, p = .001). This effect was prominent in 5 of 10 subjects (rs = .29 to .63). There were no mean differences in current age, age of onset, or current severity of symptoms between the five subjects of each group. Tic symptoms in a subgroup of patients with Tourette syndrome may be sensitive to heat. Abnormal heat regulation is not a likely explanation for the observed increase in tics. The increase may be due to normal heat-loss mechanisms through dopaminergic pathways.

Adult↗
PubMed2001

Structure of the mouse calcitonin/calcitonin gene-related peptide alpha and beta genes.

We report the cloning, genomic organization and sequence of the mouse alpha-CALC and beta-CALC genes. The two genes share extensive sequence homology. The transcription units of both genes contain 6 exons. Transcripts of the alpha-CALC gene were found to alternatively include exon 4 or exons 5 and 6. For the beta-CALC gene exon 4 was not detected in transcripts derived from this gene. The predicted mouse alpha-CGRP was found to be identical to rat alpha-CGRP, however, beta-CGRP predicted amino acid sequences revealed three amino acid differences suggesting these residues are not critical to CGRP function.

Animals↗
PubMed2001

A germline E-cadherin mutation in a family with gastric and colon cancer.

Inactivating mutations have been found in the cell-cell adhesion molecule E-cadherin (CDH1), which acts as a tumor suppressor gene in different kinds of cancers, e.g. primarily diffuse gastric cancer and lobular breast cancer. In this study, we screened for germline alterations in familial gastric and colon cancer cases. In total, 20 gastric and 18 colon cancer patients with both familial gastric and colon cancer were tested for germline E-cadherin alterations by using PCR/SSCP, specific restriction digestion test and sequencing. No pathogenic mutations were identified in the gastric cancer patients. In two colon cancer patients, a missense mutation in exon 12, codon 592 (Ala592Thr) was found. This alteration segregated with diffuse gastric cancer and colon cancer in one of the families. The prevalence of this alteration in the general population and colon cancer cases was almost the same. However, the fact that this alteration (Ala592Thr) segregated with colon cancer and diffuse gastric cancer in one big family, suggests that this E-cadherin missense alteration, beside predisposing to diffuse gastric cancer, also may play a role in colorectal carcinogenesis.

Adult↗
PubMed2001

Expression of oncogenes, tumour suppressor, mismatch repair and apoptosis-related genes in primary and metastatic melanoma cells.

Several genetic alterations have been implicated in the development of malignant melanoma, but the expression of oncogenes, tumour suppressor, mismatch repair and apoptosis-related genes and their interactions in melanoma have not been completely clarified. We simultaneously examined the expression of p73, c-erbB-2, ras, p53, Mdm2, p27, DCC, hMLH-1, hMSH-2, bcl-2, Bax and NF-kappaB, by immunocytochemistry, in both primary and metastatic melanoma cell lines derived from melanoma patients. p73 was expressed in 7/8 cell lines, but stronger expressed in the metastatic cells than in the primary melanoma cells. c-erbB-2 was detected in all 8 cell lines and ras in 2/5 metastases. p53 was found in all the cell lines and Mdm2 in 1/8 of the cell lines. In the same patient, the intensity of p27 expression was decreased from the primary to the metastatic tumours. bcl-2 was expressed in all the cell lines. Bax was absent in 5/8 cell lines. In the same patient, Bax was weakly expressed in the primary tumour but lacking in the metastases. The data demonstrate that overexpression of p73, c-erbB-2, p53 and bcl-2, and loss of Mdm2 and Bax may interact and play important roles in the development and aggressiveness of human melanoma.

Animals↗
PubMed2001

Cladospolide D, a new 12-membered macrolide antibiotic produced by Cladosporium sp. FT-0012.

A new antibiotic termed cladospolide D was isolated along with the known cladospolides A and B from the fermentation broth of Cladosporium sp. FT-0012 by solvent extraction, ODS column chromatography and preparative HPLC. The structure of cladospolide D was deduced to be (E)-2-dodecen-5-hydroxy-11-olide-4-one. Cladospolide D showed antifungal activity against Pyricularia oryzae and Mucor racemosus.

Anti-Bacterial Agents↗
PubMed2001

A method for the simultaneous evaluation of the activities of seven major human drug-metabolizing cytochrome P450s using an in vitro cocktail of probe substrates and fast gradient liquid chromatography tandem mass spectrometry.

A method for the simultaneous evaluation of the activities of seven major human drug-metabolizing cytochrome P450s (CYP3A4, CYP2D6, CYP2C9, CYP1A2, CYP2C19, CYP2A6, and CYP2C8) was developed. This method uses an in vitro cocktail of specific substrates (midazolam, bufuralol, diclofenac, ethoxyresorufin, S-mephenytoin, coumarin, and paclitaxel) and fast gradient liquid chromatography tandem mass spectrometry. The assay incubation time is 20 min, which is in the linear range for all of the substrates, and the analysis time is 4 min/sample. Substrate specificity was confirmed by incubating Escherichia coli-expressed enzymes with the cocktail. Potent specific inhibitors of the seven enzymes (ketoconazole, quinidine, sulfaphenazole, tranylcypromine, quercetin, furafylline, and 8-methoxypsoralen) were evaluated in cocktail and individual substrate incubations. Five of these inhibitors were further studied to determine more precise IC(50) values for inhibition of the seven enzymes. The IC(50) values obtained in both cocktail and individual incubations were in good agreement with published values. This cocktail method offers an efficient, robust way to determine the cytochrome P450 inhibition profile of large numbers of compounds. The enhanced throughput of this method greatly facilitates its use to assess CYP inhibition as a drug candidate selection criterion.

Chromatography, Liquid↗
PubMed2001

Pharmacokinetics and pharmacodynamics of an antisense phosphorothioate oligonucleotide targeting Fas mRNA in mice.

ISIS 22023 is a modified phosphorothioate antisense oligonucleotide targeting murine Fas mRNA. Treatment of mice with ISIS 22023 reduced Fas expression in liver in a concentration-dependent and sequence-specific manner, which completely protected mice from fulminant death induced by agonistic Fas antibody. In this study, we characterized the relationships in mice between total dose administered, dose to the target organ, and ultimately, the intracellular concentration within target cell types to the pharmacologic activity of ISIS 22023. After subcutaneous injection, ISIS 22023 distributed to the liver rapidly and remained in the liver with the t(1/2) ranging from 11 to 19 days, depending on dose. There were apparent differences in patterns of uptake and elimination in different types of liver cells. Oligonucleotide appeared within hepatocytes rapidly, whereas the peak concentrations in Kupffer cells were delayed until 2 days after dose administration. Hepatocytes cleared oligonucleotide the most rapidly, whereas Kupffer cells appeared to retain oligonucleotide longer. The reduction of Fas mRNA levels (pharmacodynamic response) paralleled the increase of oligonucleotide concentration in mouse liver with maximum mRNA reduction of 90% at 2 days after a single 50 mg/kg subcutaneous administration. Moreover, the pharmacodynamics of ISIS 22023 correlated better with the pharmacokinetics in hepatocytes, supporting the concept that the presence of oligonucleotide in target cells results in reductions in mRNA and, ultimately, pharmacologic activity. These results provide a comprehensive understanding of the kinetics of an antisense drug at the site of action and demonstrate that the reductions in mRNA induced by this antisense oligonucleotide correlate with its concentrations in cell targets.

Algorithms↗
PubMed2001

Adenoma of the posterior urethra: 131 case report.

AIM: A case-report on adenoma of the posterior urethra. METHODS: In 131 cases of adenoma of the posterior urethra, aged 17-79 (mean: 36.4) years, a detailed medical history was taken and urinalysis, urethroscopy, and prostatic specific antigen (PSA) immunohistochemical staining were performed. They were then treated with transurethral resection (TUR) or transurethral electric coagulation (TUEC). RESULTS: Hemospermia occurred in 51% of the cases, hematuria in 38%, blood overflow from the urethral orifice in 6%, and dysuria in 5%. The position of the tumor was at or around the verumontanum. The appearance of the tumor was similar to those of a papilla, a villus, a dactyl or polyp, or simply an engorgement. The tumor contained glandular alveoli and adeno-epithelial cells. PSA immunohistochemistry was positive in the cytoplasm and nucleus of the adeno-epithelial cell. One hundred and tweenty-nine cases were cured after TUR or TUEC, while 2 patients recurred and were operated again. CONCLUSION: Adenoma of the posterior urethra is a common cause of hemospermia and hematuria in young men. Urethroscopic examination and biopsy are the principal diagnostic measures. TUR or TUEC are believed to be the treatment of choice with a short-term recurrence rate of around 1. 5%.

Adenoma↗
PubMed2001

[Effect of lead exposure in prenatal and postnatal duration on infant growth].

The blood lead (PbB) levels of pregnant women and their babies were followed up since the third month of pregnancy until their babies were 2 years old. The general condition of delivery, family history of the pregnant women, feeding and development of infants were investigated. Prenatal and postnatal PbB levels and their effects on infant growth were analysed. The result showed a significant negative correlation of PbB level of pregnant women near delivery, and in umbilical cord with the growth of infants. Multiple regression analysis showed a negative correlation between PbB level and height, weight of infant at 1 and 2 years old.

Body Height↗
PubMed2001

[A computer image processing system to analyze endothelial cell-platelet thrombus quantitatively].

A Computer Image Processing System for cone-plate rolling model which forms endothelial cell-platelet thrombus in vitro is presented in this paper. Some parameters such as endothelial cell shape parameters (area, perimeter, long axial length, short axial length, angle of orientation, and shape index), platelet adhesion coverage, platelet adhesion density, diffusivity and surface reactivity constant are measured during the reaction of endothelial cells and platelet under the fluid shear stress condition. The invitro thrombus model and the corresponding quantitative analysis system is useful in the studies on endothelial cells-platelets interaction and mechanism of thrombosis and atherosclerosis.

Blood Platelets↗
PubMed2001

[CYP11B2 expression in rat liver and the efficacy of antisterone on liver fibrosis].

OBJECTIVE: To identify aldosterone synthase gene-CYP11B2 mRNA expression in rat livers and evaluate the efficacy of antisterone. METHODS: One hundred and twenty male Wistar rats were divided into 3 groups: model group (subcutaneous injection of CCl(4), 0.25 ml/100 mg, 3 times/week), antisterone group (besides same dosage of CCl(4) given, gastropufusion of antisterone of 20mg x kg(-1) x d(-1)), and control group (subcutaneous injection of olive oil). The area of collagen was examined by image analyzing system. The expression of aldosterone synthase gene-CYP11B2 mRNA was detected by RT-PCR and in situ hybridization. RESULTS: The expression of CYP11B2 mRNA, which located in the endoplasm of HSC, was upregulated when fibrogenesis occurred. The grade of fibrosis and the area of collagen in antisterone group were less than those in model group before 6th week (P<0.05). After the 6th week however, there was no significant difference between the two groups (P>0.05). CONCLUSIONS: The expression of CYP11B2 mRNA is upregulated in fibrotic liver. Antisterone can partly have a fibrogenesis-inhibiting effect on the early stage of CCl(4)-induced hepatic fibrosis.

Animals↗
PubMed2001

[Analysis on effect of inspection and maintenance (I/M) program for vehicle emission reduction].

An Inspection and maintenance(I/M) programme aims to ensure that motor vehicle emission control systems are functioning properly throughout the two stage idle test. Based on three factors including data from inspection, standard for inspection and failure rate, the effectiveness of the current I/M program was studied through the cumulative distributions. The disadvantages of the cutpoints, institution settings, management, and supervision was also analyzed. The fundamental law of emission limits was proposed.

Carbon Monoxide↗
PubMed2001

Loss of p27 expression predicts poor prognosis in patients with Dukes' B stage or proximal colorectal cancer.

p27 is a cyclin-dependent kinase inhibitor which regulates progression of cells from G1 into S phase in a cell cycle. Loss of the negative regulator may contribute to oncogenesis and tumor progression. The aim of this study was to examine p27 expression in normal mucosa, primary and metastatic tumors from patients with colorectal adenocarcinomas and to analyze association of p27 with patient survival and clinicopathological variables. p27 expression was estimated by immunohistochemistry in 178 primary colorectal cancers, 34 lymph node metastases and 48 normal mucosa samples from patients with colorectal adenocarcinoma. Associations of p27 with patient survival, clinicopathological characteristics and expression of p53, p73 and DCC were analyzed. Loss of p27 was found in 51% of primary tumors, 68% of metastases and 56% of normal samples. The intensity of p27 staining was similar in the matched primary tumor, metastasis and normal mucosa. In patients with Dukes' B or with proximal tumors, the loss of p27 predicted poorer prognosis (p = 0.03 and p = 0.05, respectively). However, there were no significant differences in the patients with other individual Dukes' stage or distal tumors. No relationships were found between p27 and patients' gender, age, tumor location, growth pattern and expression of p53, p73 and DCC (p > 0.05). The data suggest that loss of p27 was associated with poor prognosis in patients with Dukes' B tumor or those with proximal tumor. p27 might be a useful marker to identify the more progressive tumors in these groups.

Adenocarcinoma↗
PubMed2001

[The production and scavenging of reactive oxygen species in plants].

The imposition of environmental stress leads to increased production of reactive oxygen species (ROS) in plant cells, Which can damage proteins, membrane lipids, DNA and other cellular components. Plants have evolved enzymatic and no-enzymatic protection mechanisms that efficiently scavenge ROS. Enzymatic detoxication system includes superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT) and glutathione peroxidase (GAX); no-enzymatic antioxidants include ascorbic acid, glutathione, mannitol and carotenoids, which occur in high concentrations in plants. The over-expression and accumulation strategies of these antioxidants in plants have been followed up to now, and have gained many transgenic plants showing increased stress tolerance.

Genetic Engineering↗
PubMed2001

[Primary study on heart rate variability of non-linear dynamics in patients with coronary artery disease and diabetes].

This is a comparative study on the non-linear dynamics between 30 healthy controls and three groups of patients with single coronary artery disease(n = 20), multi-coronary disease(n = 8), and diabetic patients with diabetic autonomic neuropathy (DAN)(n = 18), respectively. We selected and adopted six quantity indices of dispersed-dot plot, including the area of plot (SQ), long-axis (LA), short-axis (SA), the angle of long-axis and short-axis (ALS), vector length index (VLI) and vector angle index (VAI), and Kolmogorov entropy and fractal dimension. We found that the non-linear indices in healthy control had obvious day-to-night change, while the change in coronary artery disease patients decreased and disappeared in diabetics. By the findings that both coronary artery disease patients and diabetic patients had the turbulence of vegetal nerve system, we concluded that the vegetal nerve activity might be an important factor in heart non-linear dynamics. And marked differences in the non-linear indices were seen between the normal control, the single-vessel, multi-vessel coronary artery disease patients, and the diabetic patients, thus suggesting that these indices may be used in clinical practice.

Adult↗