Biomedical subjects

Rong Tang

Publications and source records attributed to Rong Tang.

50 records · Page 3Linked to original sources

PubMed2003

Isolation and characterization of a human putative receptor protein kinase cDNA STYK1.

Protein kinases (PKs) represent a well studied but most diverse protein superfamily. The covalent, reversible linkage of phosphate to serine, threonine, and tyrosine residues of substrate proteins by protein kinases is probably ubiquitous cellular mechanism for regulation of physiological processes. It is known to us that most signaling pathways impinge at some point on protein kinases. Here we report a human putative receptor protein kinase cDNA STYK1. The STYK1 cDNA is 2749 base pairs in length and contains an open reading frame encoding 422 amino acids. The STYK1 gene is mapped to human chromosome 12p13 and 11 exons were found. RT-PCR showed that STYK1 is widely expressed in human tissues.

Amino Acid Sequence↗

PubMed2003

Radical-trapping activity, blood pressure, and carotid enlargement in women.

The aim of this study was to evaluate the influence of traditional and nontraditional (oxidation markers) cardiovascular risk factors on the degree of adaptive response of the carotid wall to atherosclerotic disease, a process known as arterial enlargement. Five thousand sixty-two clinically healthy, middle-aged women living in the area of Naples participated in the "Progetto Atena" study; 310 of these women (potentially at higher atherosclerotic risk) underwent a high-resolution ultrasound scan of the carotid arteries. In addition to routine biochemical tests, these women had the determination of serum IgG antibody titer against oxidized LDL and measurement of thiobarbituric acid reactive substances and total radical-trapping activity potential of plasma. Age, systolic blood pressure, body mass index, and radical-trapping activity were all positively correlated with external and internal common carotid diameters, whereas triglycerides (positively) and HDL cholesterol (inversely) were related only to external diameter. After controlling for traditional cardiovascular risk factors, associations still persisted for age, systolic blood pressure, and plasma radical-trapping activity with external carotid diameters. However, in the quartile of women with highest total cholesterol (>7.38 mmol/L), the slope of the regression line between systolic blood pressure and external diameter was significantly flatter than in the three other quartiles (test for difference, P=0.014). Outward carotid enlargement is related to traditional and nontraditional risk factors and comes even before plaque development. Women with poor resistance to oxidative stress potentially have a difficulty to remodel their arteries in response to atherosclerotic stimuli.

Age Factors↗

PubMed2003

[Research in use of vascular endothelial cells to promote osteogenesis of marrow stromal cells].

Osteogenesis deep in the materials is postponed because the blood vessels grow into the materials very slowly. It is one of the key challenges to the bone tissue engineering researchers. However, it was found that marrow stromal cells can produce vascular endothelial growth factor (VEGF) while endothelial cells produce bone morphogenetic protein (BMP). So we presume if we have co-culture of marrow stromal cells and endothelial cells on the biomaterials, osteogenesis and angiogenesis may be promoted simultaneously. In this experiment, we compare the alkaline phosphatase (ALP) activity and osteocalcin (OCN) production of three groups: the marrow stromal cells under activation of endothelial cells culture fluid, the induced marrow stromal cells, and the untreated marrow stromal cells. The results reveal that the ALP activity and OCN production of the marrow stromal cells under activation of endothelial cell culture fluid and the ALP activity and OCN production of the induced marrow stromal cells do not show statistically significant difference, but they are significantly higher than those of the untreated marrow stromal cells (P < 0.01). It is concluded that the VEGF in the endothelial cell culture fluid can promote osteogenesis as effective as osteogenic induction medium can do.

Alkaline Phosphatase↗

PubMed2002

Impact of multiple coronary risk factors on the intima-media thickness of different segments of carotid artery in healthy young adults (The Bogalusa Heart Study).

Although risk factors for coronary artery disease are also associated with increased carotid artery intima-media thickness (IMT) as measured by B-mode ultrasonography in middle-aged and older persons, information on the impact of multiple risk factors on the IMT of different segments of the carotid artery in young adults is limited. This relation was examined in a sample of 518 black and white subjects (mean age 32 years; 71% white, 39% male) enrolled in the Bogalusa Heart Study. IMT was thicker and more skewed in the bulb compared with other carotid segments. Race differences (blacks more than whites) were noted for the common carotid (p <0.001) and carotid bulb (bifurcation) IMT (women only, p <0.001). Men had a greater IMT in the common carotid (p <0.05), internal carotid (p <0.05), and carotid bulb (whites only, p <0.001). In a multivariate analysis, systolic blood pressure, race, age, low-density lipoprotein (LDL) cholesterol, and high-density lipoprotein (HDL) cholesterol weree entered into a model in that order and accounted for the 16.7% variance in the common carotid IMT; age, systolic blood pressure, HDL cholesterol, LDL cholesterol, race, and insulin levels explained the 19.4% variance in the carotid bulb IMT. Gender and body mass index (BMI) accounted for the 4.7% variance in the internal carotid IMT. Increases in IMT with increasing number of risk factors (cigarette smoking, higher total cholesterol to HDL cholesterol ratio, higher systolic blood pressure, greater waist circumference, and higher insulin level) were noted for the common carotid and carotid bulb segments (p for trend <0.001 for both). The observed deleterious trend of increasing IMT at different carotid segments with increasing number of risk factors in free-living, asymptomatic young subjects underscores the importance of profiling multiple risk factors early in life. Ultrasonography of carotid arteries, especially at the bifurcation, may be helpful along with measurements of risk factors for evaluation of asymptomatic atherosclerotic disease.

Adult↗

PubMed2002

Associations of extracranial carotid atherosclerosis progression with coronary status and risk factors in patients with and without coronary artery disease.

BACKGROUND: Intimal medial thickness of the extracranial carotid arteries (IMT) is related to coronary artery disease (CAD) and CAD risk factors. Few studies have explored the association of risk factors with progression of IMT, and none have evaluated their associations with IMT progression specifically in patients with and without CAD. METHODS AND RESULTS: We used coronary angiography to identify 280 patients equally divided between men and women and those with either > or =50% coronary artery stenosis or no CAD. Risk factors were measured at baseline and IMT was measured at baseline and yearly for 3 years in 241 of these individuals. Baseline risk factors and CAD status were related to IMT progression. IMT of patients with CAD progressed 3 times faster than that of patients with no CAD (mean+/-SEM, 33.7+/-7.4 versus 8.9+/-7.1 microm/year; P=0.02), and CAD status and high-density lipoprotein (HDL) cholesterol were independently associated with IMT progression. Male sex, increased waist to hip ratio, cigarette smoking, increased triglycerides, and decreased HDL cholesterol were associated with increased progression in CAD patients. CONCLUSIONS: Patients with CAD have more rapid progression of IMT than CAD-free controls, and risk factors are related to progression in them.

Carotid Artery Diseases↗

PubMed2002

Postprandial enrichment of remnant lipoproteins with apoC-I in healthy normolipidemic men with early asymptomatic atherosclerosis.

OBJECTIVES: Recently, we reported that exaggerated postprandial triglyceridemia in normolipidemic patients with coronary artery disease is associated with enrichment of remnant lipoproteins with apolipoprotein C-I (apoC-I). In this study, the number and composition of chylomicron remnants and very low density lipoproteins (VLDLs) were examined in 30 asymptomatic normolipidemic 50-year-old men with and without early carotid atherosclerotic lesions. METHODS AND RESULTS: Intima-media thickness of the far wall of the common carotid artery was determined by B-mode ultrasound. Triglyceride-rich lipoproteins were subfractionated by density gradient ultracentrifugation and separated into VLDL and chylomicron remnant fractions by immunoaffinity chromatography. The postprandial triglyceridemia and increase in triglyceride-rich lipoprotein particle number (ie, apolipoprotein B concentrations) were not exaggerated in men with early atherosclerosis. In contrast, their large (Svedberg flotation rate 60 to 400) and small (Svedberg flotation rate 20 to 60) chylomicron remnants and VLDL were greatly enriched with apoC-I, and their small chylomicron remnants and VLDL particles were relatively enriched with cholesterol. Moreover, the number of apoC-I molecules on small chylomicron remnants was strongly associated with the degree of atherosclerosis. CONCLUSIONS: Early asymptomatic atherosclerosis in normolipidemic men without exaggerated postprandial triglyceridemia is associated with the enrichment of postprandial chylomicron and VLDL particles with apoC-I. Therefore, it is conceivable that the apoC-I content of lipoprotein remnants may serve as an early marker of coronary artery disease risk.

Apolipoprotein B-100↗

PubMed2002

Discovery and analysis of hepatocellular carcinoma genes using cDNA microarrays.

PURPOSE: Microarray analysis on a genomic scale was used to profile changes in gene expression accompanying hepatocellular carcinoma. METHODS: Gene expression profiles of liver tissues from twelve hepatocellular carcinoma samples relative to the gene expression profile of the normal liver tissue were analyzed using 4096 chips and 12800 chips. The results of microarray experiments were verified by the Northern blot technique. RESULTS: A group of 1,820 genes with altered expression were identified in more than 50% of the patients examined. This highly concordant expression profile included human genes encoding proteins involved in the function of peroxisomes, serum control, polycyclic aromatic hydrocarbon carcinogenesis, cell growth and differentiation, metastasis, the function of the immune system, apoptosis, and remodeling of the cytoskeleton. CONCLUSIONS: The newly identified genes afford a quantitative view of the changes that accompany liver cancer at the genomic level, enable deeper insights into the molecular basis of disease, and provide an extensive list of potential early-onset molecular markers for improved diagnosis.

Adult↗

PubMed2002

Cloning, expression and characterisation of a human Nudix hydrolase specific for adenosine 5'-diphosphoribose (ADP-ribose).

The human NUDT9 gene has been mapped to 4q22 and shown to give rise to two alternatively spliced mRNAs, NUDT9alpha and NUDT9beta, that encode a member of the Nudix hydrolase family. Both transcripts were readily detected in heart and skeletal muscle and also in liver, kidney and pancreas. NUDT9alpha protein was expressed in Escherichia coli and shown specifically to hydrolyse ADP-ribose and IDP-ribose to the corresponding nucleoside 5'-monophosphates and ribose 5-phosphate. No other nucleotide substrates were hydrolysed significantly. NUDT9alpha was inhibited by fluoride and by N-acetyl-p-benzoquinoneimine and had K(m) and kcat values of 180 microM and 8 s(-1) respectively with ADP-ribose as substrate. The full-length 39.1 kDa NUDT9alpha has a potential mitochondrial leader sequence, which would give rise to a mature 34.2 kDa mitochondrial protein. Apart from the high K(m) value, the properties of NUDT9alpha are close to those of the known mammalian 40 kDa cytoplasmic ADPRibase-1 and 35 kDa mitochondrial ADPRibase-m. However, any relationship between the NUDT9 species and the previously reported ADPRibases remains to be established.

Adenosine Diphosphate Ribose↗

PubMed2002

Identification and characterization of AGTRAP, a human homolog of murine Angiotensin II Receptor-Associated Protein (Agtrap).

Several classes of cytoplasmic proteins have been found to interact specifically with the carboxyl-terminal cytoplasmic region of the angiotensin II type 1 (AT(1)) receptor to regulate different aspects of AT(1) receptor physiology. The murine Angiotensin II Receptor-Associated Protein (Agtrap) is a new member of them. We have recently cloned a new human gene cDNA that codes for a homolog of the murine Agtrap protein from a human fetal brain cDNA library. The deduced polypeptide product of the cDNA is 22 kDa in size, and its DNA and amino acid sequences are 85 and 77% identical to those of the mouse Agtrap gene, respectively. Hence we have named it the human Angiotensin II Receptor-Associated Protein (AGTRAP) gene. The mRNA of AGTRAP was most abundantly expressed in kidney, heart, pancreas and thyroid. Using the yeast two-hybrid screening of a human fetal brain cDNA library, we have identified a new interaction partner of the human AGTRAP protein, RACK1 (Receptor of Activated Protein C Kinase). The AGTRAP-RACK1 interaction was confirmed by GST fusion protein pull-down assays, co-immunoprecipitation and surface plasmon resonance. We suggest that the AGTRAP-RACK1 interaction may help to recruit signaling complex to the AT(1) receptor to affect AT(1) receptor signaling.

Adaptor Proteins, Signal Transducing↗

PubMed2002

Isolation of novel differentially expressed genes related to human glioma using cDNA microarray and characterizations of two novel full-length genes.

Identification of the genes that are differentially expressed between brain tumor and normal brain tissues is important for understanding the molecular basis of these nerve system tumors and for defining possible targets for therapeutic intervention. This investigation is intended to obtain differentially expressed genes related to human glioma using cDNA microarray. Total RNA was extracted from human glioma specimens and normal brain tissues, and mRNA was obtained by oligotex chromatography. The cDNA microarray contains 4366 novel cDNA clones. The results of hybridization were scanned using computer system. Two genes selected from the results of cDNA microarray hybridization were subsequently analyzed by bio-informatic approach, Northern blot, in situ hybridization and radiation hybridization. We demonstrated that at a differentially expressed ration of two to three times, 15 cDNA clones were considered differentially expressed. Two novel full-length genes were selected for further investigation, one named human PKIbeta gene (clone 436F11, GenBank with accession number: AF225513) was over-expressed in normal brain tissues and the other named human ribosomal protein L14.22 gene (clone 507E08, GenBank with accession number: AF329277) was over-expressed in gliomas. Furthermore, the 436F11 gene was located on 6q21-q23 between the D6S304 and D6S2156 markers, while the 507E08 gene was located between the D14S1066 and D14S265 markers. We realized that cDNA microarray technology can be successfully applied to identify differentially expressed genes in human glioma. This approach is superior to routine representational difference analysis, suppression subtractive hybridization and Northern blot for detection and isolation of differentially expressed genes in different tissues. At present, we have discovered two novel full-length genes related to human glioma and their characterizations have been partially clarified.

Amino Acid Sequence↗

PubMed2002

Cloning and identification of a cDNA that encodes a novel human protein with thrombospondin type I repeat domain, hPWTSR.

A cDNA was isolated from the fetal brain cDNA library by high throughput cDNA sequencing. The 2390 bp cDNA with an open reading fragment (ORF) of 816 bp encodes a 272 amino acids putative protein with a thrombospondin type I repeat (TSR) domain and a cysteine-rich region at the N-terminus, so it is named hPWTSR. We used Northern blot detected two bands with length of about 3 kb and 4 kb respectively, which expressed in human adult tissues with different intensities. The expression pattern was verified by RT-PCR, revealing that the transcripts were expressed ubiquitously in fetal tissues and human tumor tissues too. However, the transcript was detected neither in ovarian carcinoma GI-102 nor in lung carcinoma LX-1. Blast analysis against NCBI database revealed that the new gene contained at least 5 exons and located in human chromosome 6q22.33. Our results demonstrate that the gene is a novel member of TSR supergene family.

Adult↗

PubMed2002

Association of impaired glucose homeostasis with preclinical carotid atherosclerosis in women: Impact of the new American Diabetes Association criteria.

The aim of this study was to determine whether impaired glucose regulation, defined according to the new American Diabetes Association (ADA) criteria, is associated with early signs of carotid atherosclerosis. We examined 310 clinically healthy women from southern Italy, aged 30 to 69 years, recruited for a prospective study, currently ongoing, on the etiology of cardiovascular disease and cancer in the female population (Progetto Atena). All subjects underwent cardiovascular risk factor assessment and high resolution B-mode ultrasound to measure intima-media thickness (IMT) of common carotid arteries and carotid bifurcations. At the time of our survey, fasting glucose levels > or = 7.0 mmol/L had already been found in 7 women, 17 participants were diagnosed on that occasion as having new diabetes, 38 had impaired fasting glucose (IFG), and the remaining 248 presented normal fasting glucose values (NFG). Diabetic women showed a worse cardiovascular risk profile, with higher values of triglycerides, body mass index, and diastolic blood pressure than either normoglycemic or IFG subjects. The frequency of atherosclerotic plaques (IMT > 1.2 mm) increased as glucose homeostasis worsened. In multivariate logistic regression analyses, only diabetes mellitus was associated with a significantly increased risk of carotid atherosclerosis (odds ratio [OR], 11.5; 95% confidence interval [CI], 1.4 to 92.7). Our findings suggest a definite association between diabetes mellitus, as defined by the new ADA diagnostic criteria and early carotid structural changes. Furthermore, the condition of IFG does not seem to identify subjects at significantly increased atherosclerotic risk.

Adult↗

PubMed2002

[cDNA microarray in the gene expression pattern in lymphatic metastasis of pancreatic carcinoma].

OBJECTIVE: Analysis of differential gene expression profiles by cDNA microarray in pancreatic carcinoma with or without lymphatic metastasis. METHODS: cDNA microarray was prepared by spotting polymerase chain reaction (PCR) products of 4 000 human genes onto specially treated glass slides. The cDNA probes were prepared by labeling normal tissue mRNA and cancer tissue mRNA with Cy3-dUTP and Cy5-dUTP, separately through reverse transcription. The mixed probes were, then, hybridized to the cDNA microarray. The chips were scanned by ScanArray 3000 laser scanner (General Scanning, Inc) on two wavelengths. The acquired image was analyzed by ImaGene 3.0 software (BioDiscovery, Inc). The intensity of each spot on the two wavelengths represented the quantity of Cy3-dUTP and Cy5-dUTP, with Cy5 to Cy3 ratio computed on each. RESULTS: Fifty-six genes (including 24 previously reported) exhibited differential expressions in 2 specimens of pancreatic carcinoma with lymphatic metastasis and 2 without. CONCLUSION: cDNA microarray provides an promising approach to specific gene expressions of the presence of lymphatic metastasis in human pancreatic carcinoma.

Aged↗

PubMedDate not supplied

Cardiovascular risk profile of asymptomatic healthy young adults with increased carotid artery intima-media thickness: the Bogalusa Heart Study.

OBJECTIVE: The cardiovascular (CV) risk profile of healthy young adults was studied at the extreme 5th percentiles of carotid intima-medial thickness (IMT) as measured by B-mode ultrasonography in different segments of the carotid artery. METHODS: Anthropometric variables, blood pressure, laboratory data, family history health habits were collected from 518 individuals (mean age 32 years). Individuals in the top and bottom 5th percentiles of IMT of carotid bulb or bifurcation area (n = 22) and the common carotid (n = 25) segments were examined for presence of risk factors. Univariate analyses compared the two groups, t tests, and chi-square tests were performed. RESULTS: The common carotid segment top and bottom percentiles of IMT differed with respect to age (p < 0.000), BMI (p < 0.001). In contrast, carotid bulb segment top and bottom percentiles differed with respect to age, (p = 0.001), BMI (p = 0.004), HDL cholesterol (p 0.006), LDL cholesterol (p = 0.023), ECG diagnosis (p = 0.016), smoking status (p = 0.004). The individuals in the top 5th percentile of IMT of the bifurcation area were more obese (BMI > 30), hypertensive (BP > 140/90 or on medications), dyslipidemic (LDL > 130 mg/dl, triglycerides > 150, HDL < 40 mg/dl), and more often had an abnormal ECG, and a history of smoking. CONCLUSION: The observed deleterious effect of CV risk factors on IMT of the carotid artery, a surrogate measure of coronary atherosclerosis, underscores the risk factor profile history in youth. The prevalence of multiple risk factors among those in the top 5th percentile of IMT was significantly higher with respect to the carotid bulb segment only (p = 0.000), suggesting more sensitivity to the risk factor burden compared with the common carotid segment. These observations have important implications in preventive cardiology.

Adult↗