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Biomedical subjects

W Wang

Publications and source records attributed to W Wang.

At least 325 records · Page 18Linked to original sources

Ultrasonographic texture analysis of parenchymatous organs by the four-neighborhood-pixels algorithm: clinical experiment.

OBJECTIVE: The parenchyma of organs such as liver, thyroid, and mammary gland during climacterium have common ultrasonographic textural features, which together form what we call small-dot-structure texture. To study this texture we designed the 4-neighborhood-pixels algorithm, an ultrasonographic texture analysis algorithm. The objective of this study was to confirm whether the 4-neighborhood-pixels algorithm can reflect the features of small-dot-structure texture. METHODS: A changed small-dot-structure texture and 3 other textures were compared with the normal small-dot-structure texture in 4 groups, and a histogram algorithm was used for contrast with the 4-neighborhood-pixels algorithm. RESULTS: The 4-neighborhood-pixels algorithm could reflect all the textural differences, but the histogram algorithm could reflect only some of them. CONCLUSIONS: The 4-neighborhood-pixels algorithm is a good algorithm for analyzing ultrasonographic small-dot-structure texture. Not only can it reflect changes in the small-dot-structure texture, but it can also differentiate between small-dot-structure and non-small-dot-structure textures.

Adipose Tissue↗

[Study on polymorphism of D gene exons among RhD-negative Chinese Han population].

OBJECTIVE: To explore the genomic structure of 8 exons in D gene of RhD(-) Chinese Han population. METHODS: Polymerase chain reaction-sequence specific primers(PCR-SSP) were used to study genomic DNA from 50 samples of RhD(-) Chinese Han donors. Exons 2, 3, 4, 5, 6, 7, 9, 10 of RHD gene and exons 1, 2, 4, 5 of RHCE gene were specifically amplified, also intron 4 of them was amplified. RESULTS: Phenotypes of the 50 RhD(-) donors were: 22 ccdee, 22 Ccdee, 3 CcdEe, 3 CcdEe. The 8 exons of RHD gene were completely absent in 25 donors with ccdee or ccdEe phenotype, while polymorphisms of D gene exons were found in 25 donors with Ccdee or CcdEe phenotype: the presence of all 8 exons of D gene in 9 donors, the absence of the 8 exons in 7 donors, the presence of exon 2 in 5 donors, the presence of exon 6 in 3 donors and the presence of exons 2, 6, 10 in 1 donor were demonstrated. CONCLUSION: Polymorphisms of RHD gene exons were present among RhD(-) Chinese Han blood donors. The 8 exons of RHD gene were completely absent in donors with Rhesus cc phenotype, while 5 polymorphisms of RHD gene exons were found in donors with Rhesus Cc phenotype. The discrepancy of the RHD gene in RhD(-) individuals between Chinese Hans and Caucasians indicates that care should be exercised by clinicians in the use of the RhD genotyping results.

China↗

Solution structure of cytochrome b(5) mutant (E44/48/56A/D60A) and its interaction with cytochrome c.

Using 1617 meaningful NOEs with 188 pseudocontact shifts, a family of 35 conformers of oxidized bovine microsomal cytochrome b5 mutant (E44/48/56A/D60A) has been obtained and is characterized by good resolution (rmsd to the mean structure are 0.047 +/- 0.007 nm and 0.095 +/- 0.008 nm for backbone and heavy atoms, respectively). The solution structure of the mutant, when compared with the X-ray structure of wild-type cytochrome b(5), has no significant changes in the whole folding and secondary structure. The binding between cytochrome b(5) and cytochrome c shows that the association constant of the mutant-cytochrome c complex is much lower than the one for wild-type complex (2.2 x 10(4) M(-1) vs. 5.1 x 10(3) M(-1)). The result suggests the four acidic residues have substantial effects on the formation of the complex between cytochrome b(5) and cytochrome c, and therefore it is concluded reasonably that the electrostatic interaction plays an important role in maintaining the stability and specificity of the complex formed. The competition between the ferricytochrome b(5) mutant and [Cr(oxalate)(3)](3-) for ferricytochrome c shows that site III of cytochrome c, which is a strong binding site to wild-type cytochrome b(5), still binds to the mutant with relatively weaker strength. Our results indicate that certain bonding geometries do occur in the interaction between the present mutant and cytochrome c and these geometries, which should be quite different from the ones of the Salemme and Northrup models.

Amino Acid Sequence↗

Telomerase activity in relation to pro- and anti-apoptotic protein expression in high grade non-Hodgkin's lymphomas.

BACKGROUND AND OBJECTIVES: Telomerase activity (TA) is determined by the catalytic unit telomerase reverse transcriptase (hTERT). In vitro studies show that hTERT is downregulated by wild type p53 and TA is upregulated by BCL-2 expression. The aim of this study was to investigate the relationship of TA and mRNA expression of hTERT, telomerase RNA (hTER) and Tankyrase in 31 samples from patients with high-grade non-Hodgkin's lymphoma (HG-NHL). The results were then related to apoptosis and proliferation and the expression of p53 and BCL-2 family member proteins. DESIGN AND METHODS: The telomeric repeat amplification protocol (TRAP) assay and reverse transcription-polymerase chain reaction (RT-PCR) were used to quantify TA, and hTERT, hTER and Tankyrase mRNA expression. Proliferation (Ki67), p53, BCL-2, MCL-1, BAX and BAK protein expression were evaluated by immunohistochemistry. Apoptosis was evaluated by TUNEL staining. RESULTS: TA was detected in 93% of HG-NHL and tended to be higher in p53+ lymphomas. A positive correlation existed between mRNA expression of hTERT, hTER and Tankyrase. hTERT mRNA expression tended to be higher with increasing levels of apoptosis and proliferation, in HG-NHL samples lacking BAX expression and in samples from patients with survival shorter than 3.5 years. hTER mRNA expression was significantly higher in BAX and BAK negative samples. INTERPRETATION AND CONCLUSIONS: Telomerase is activated or upregulated in the majority of HG-NHL. Enhanced TA combined with deregulation of the factors responsible for cell survival and proliferation may contribute to the development and progression of lymphomas. Observation that high hTERT mRNA expression may be related to shorter survival should prompt further investigation of the clinical significance of TA and its components in HG-NHL.

Adult↗

[Prokaryotic expression of recombinant grass carp growth hormone].

The recombinant plasmid containing a synthetic grass carp growth hormone cDNA was transformed into Escherichia coli BL21 (DE3) and expressed efficiently, induced by 1 mmol/L IPTG. 12.5% SDS-PAGE showed the molecular weight of new added protein in Escherichia coli BL21 (DE3) is consistent with that of grass carp growth hormone. The recombinant protein was composed of approximately 40% of the total bacterial proteins. The target protein was purified with Ni-NTA affinity column. Western-blotting conformed that recombinant protein could specifically react with antibody against grass carp growth hormone. ELISA-receptor assay showed the bioactivity of recombinant protein is consistent with that of nature grass carp growth hormone.

Animals↗

The effects of Lei Gong Teng on reproductive hormones.

The serum reproductive hormone levels were examined with radioimmunoassay in women of child-bearing age before and after treatment with the prescriptions containing Lei Gong Teng ([symbol: see text] Radix Tripterygii Wilfordii). The results showed that Lei Gong Teng could induce amenorrhea, but it was reversible.

Adolescent↗

Corticosterone supplementation reduced selective protein kinase C isoform expression in the epidermis of adrenalectomized mice.

Previous research in this laboratory demonstrated elevated plasma corticosterone and reduced protein kinase C (PKC) activity and selective isoform expression in the epidermis of dietary energy-restricted mice. Because PKC is implicated in skin carcinogenesis and because both energy restriction and glucocorticoid hormone inhibit skin carcinogenesis, the purpose of the present research was to determine whether the elevated glucocorticoid hormone in the energy-restricted mouse contributed to the changes in PKC protein expression. Two strategies were used to control corticosterone in adrenalectomized mice: (a) corticosterone-containing pellets were implanted in mice, and a dose response increase in corticosterone was observed with 5-, 10-, and 35-mg corticosterone implants with average peak values of 68 +/- 22 ng/ml (P < 0.01); and (b) corticosterone was administered in the drinking water, and plasma corticosterone was elevated in a dose-dependent manner in mice killed at 6:00-6:30 p.m. (P < 0.01; peak values of 300-400 ng/ml). The expression of PKCalpha, PKCdelta, and PKCepsilon protein were not consistently altered by corticosterone with the two strategies. PKCeta protein expression was elevated in the adrenalectomized mice administered 3 or 60 microg of corticosterone/ml in drinking water (P < 0.01). PKCzeta protein expression was reduced by all doses of corticosterone in the implant or drinking water (P < 0.05), and a reduction of 41% was achieved with the mice administered 60 microg of corticosterone/ml in drinking water. In mice fed control or energy-restricted diet, with or without adrenalectomy, PKCzeta protein was reduced in sham-operated, energy-restricted mice in comparison with control diet, sham-operated mice (P < 0.02), whereas PKCzeta protein was not significantly different between adrenalectomized control and adrenalectomized, energy-restricted mice. These data indicate that administration of corticosterone in drinking water most closely mimicked the circulating corticosterone and epidermal PKC changes observed in dietary energy restriction. Elevated plasma glucocorticoid levels in the dietary energy-restricted mouse may contribute to the alteration of PKC protein levels in the epidermis.

Adrenalectomy↗

[Adsorption of p-chlorophenol by biofilm and its components].

The p-chlorophenol (4-cp) adsorption to biofilm components was investigated by the experiment. Biofilm components included modeling water particulate (kaolin) with biofilm coating, bacterial cell, exopolysaccharide, kaolin and kaolin with exopolysaccharide. The adsorption of 4-cp in these systems could be described by Langmuir and Freundlich isotherm equations except the system of kaolin with exopolysaccharide. Under the condition of 25 degrees C and pH of 6.1 in these reaction systems, bacterial cell and EPS adsorbed more 4-cp than kaolin. The biofilm coating of kaolin affected its adsorption to 4-cp. Kaolin with biofilm coating adsorbed more 4-cp than that without biofilm coating.

Adsorption↗

The regulation of sympathetic outflow in heart failure. The roles of angiotensin II, nitric oxide, and exercise training.

Sympatho-excitation is a hallmark of the chronic heart failure (CHF) state. It has long been assumed that this sympatho-excitation is mediated by a reduction in sensory input from cardiopulmonary and arterial baroreceptors. However, recent data suggest that these reflexes may only be important in the initiation of the sympatho-excitatory state and may not be necessary for the sustained increase in sympathetic nerve activity (SNA) in CHF. Two humoral factors that can influence SNA are nitric oxide (NO) and angiotensin II (AngII). Animals with CHF exhibit a downregulation in central gene expression for the neuronal isoform of nitric oxide synthase (nNOS). In addition, blockade of AngII receptors in combination with NO donation reduces SNA in animals with CHF, while NO donation alone has no effect on SNA. Chronic exercise training (EX) reduces both plasma AngII and SNA in rabbits with CHF while improving baroreflex function. Blockade of AT1 receptors enhances baroreflex function in non-EX CHF rabbits, but has little effect in EX CHF rabbits. These data suggest that the sympatho-excitatory state that is typical of CHF is, in part, due to changes in AngII and NO. Depressed baroreflex function and the elevated SNA can be improved by EX in animals with CHF.

Angiotensin II↗

Effect of fibroids on cumulative probability of pregnancy in women taking follicle maturing drugs without assisted reproductive technology.

PURPOSE: To determine if the presence of uterine fibroids adversely affect in vivo conception rates. METHODS: Pelvic ultrasound evaluation of the presence or absence of fibroids in consecutive infertility patients not treated with assisted reproductive technology in a two-year period. Conception outcome noted. Data analyzed according to the presence or absence of fibroids. RESULTS: No difference in cumulative probability of pregnancy after five months was seen in patients with or without the presence of fibroids. There were no confounding variables found that could have skewed the pregnancy rates in one direction or the other. CONCLUSION: In general the presence of fibroids do not adversely affect conception outcome for in vivo pregnancies. However, since the majority of the fibroids were small (< 6 cm) and were not submucosal and did not compress the endometrial cavity, larger studies are needed to address specific subtypes and circumstances on pregnancy outcome.

Adult↗

[Overexpression of p27(KIP1) induced by Bak gene leads to the arrest in G(1) phase of HCC-9204 cell line].

OBJECTIVE: To explore whether p27(KIP1) plays an important role in prolonging cell cycle in G(1) phase and leading to apoptosis of HCC-9204 cells. METHODS: A model of Bak-induced cell cycle arrest in G(1) phase and subsequent apoptosis was established. p27(KIP1) was obtained from the model and sequenced afterwards. A zinc inducible p27(KIP1) stable transfectant was constructed. The effects of inducible p27(KIP1) on cell growth and cell cycle arrest were examined in control pMD and pMD-KIP1 transfected HCC-9204 cells. Western blot was performed to evaluate the expression of p27(KIP1). RESULTS: The cell growth was reduced by 35% upon 48h of p27(KIP1) induction with zinc treatment as determined by trypan blue exclusion assay. p27(KIP1) caused cell cycle arrest at 24h after induction, with 40% increase in G(1) population. CONCLUSIONS: Bak may induce cell cycle arrest in G(1) phase through up-regulating expression of p27(KIP1). The inducible p27(KIP1)-expressing cells provide a model to assess p27(KIP1) function.

Apoptosis↗

[Clone and expression of human soluble CD14 and study of its function].

Human soluble CD14(sCD14) cDNA fragment was amplified using total RNA extracted from U937 cells by RT-PCR of sCD14 gene, and the recombinant expression plasmid pEF1/HisC/sCD14 348aa was constructed. Then the expression in eukaryotic cell was carry out by liposome transfection method. It demonstrated that the expression level was relatively high by scanning map identification. The expressed product was purified by immunoaffinity chromatography and the purity was above 90%. The changes of CD14 brought by LPS stimulating U937 cell proved the product had the function of combine with LPS.

Cloning, Molecular↗

An association between genetic polymorphisms in the ileal sodium-dependent bile acid transporter gene and the risk of colorectal adenomas.

Epidemiological and experimental studies have implicated bile acids (particularly secondary bile acids) as important factors in the development of colorectal cancer. The ileal sodium-dependent bile acid transporter (ISBT) is a crucial player in the enterohepatic circulation of bile acids. Genetic defects in ISBT may result in malabsorption of bile acids and a loss of bile acids into the large intestine, with a resultant increase in the cytotoxic secondary bile acids in the colon. In a case-control study, we investigated the association between two sequence variations in SLC10A2, the gene encoding ISBT, and colorectal adenomas, a precursor lesion of colorectal cancer. The frequency of the missense mutation in codon 171 of exon 3 (a nucleotide transversion from G to T resulting in an alanine to serine substitution) was not significantly different between cases and controls. However, we found a 2-fold higher risk of colorectal adenomas associated with a C-->T nucleotide transition in codon 169 of exon 3 (odds ratio = 2.06; 95% confidence interval: 1.10-3.83). Logistic regression analysis using A171S/169 C-->T haplotypes as the allelic markers showed that among AA wild-type homozygotes for A171S mutation, this C-->T nucleotide transition in codon 169 was associated with a 2.42 times increased risk (odds ratio = 2.42; 95% confidence interval: 1.26-4.63). This initial observation of an association between a polymorphism in the SLC10A2 gene and the risk of colorectal adenomatous polyps would, if confirmed by other studies, support the role of bile acids in the carcinogenesis of colorectal cancer.

Adenoma↗

Evaluation of insulin secretion of isolated rat islets cultured in extracellular matrix.

Islet isolation involves enzymatic digestion of the interstitial matrix and mechanical disruption of the tissue. It is possible that a fundamental change of islet biology resulting from the loss of critical factors required for islet function or survival will occur. Extracellular matrix (ECM) is one of the most important components of the islet microenvironment. Reconstruction of the cell-matrix relationship seems to be effective for improving the loss of differentiated islet structure and function. The purpose of this study was to characterize and compare the effects of collagen gel mixture or Matrigel on beta-cell function and islet cell survival. After isolation by the collagenase digestion technique, rat islets were divided and cultured with various types of collagen gel mixture. They were assessed for their glucose-stimulated insulin secretion and cell viability. Glucose-induced insulin secretion of islets cultured with collagen type I gel or a mixture of collagen type I and IV was improved after 11 days in culture. In conclusion, a type of gel composed of collagen type I and/or type IV as an islet microenvironment is sufficient to maintain glucose responsiveness and may be useful for islet transplantation.

Animals↗

Effect of basic fibroblast growth factor on insulin secretion from microencapsulated pancreatic islets: an in vitro study.

Microencapsulation of pancreatic islets represents a potentially effective method to prevent graft rejection in allotransplantation or xenotransplantation without the need of immunosuppression. Adequate insulin secretion and glucose responsiveness of microencapsulated pancreatic islets has been regarded as a prerequisite for successful transplantation. The microencapsulated pancreatic islets were respectively cultured in bFGF+ RPMI-1640 medium (bFGF+) or bFGF- RPMI-1640 medium (bFGF-) for 21 days. The functional activities of microencapsulated pancreatic islets were assessed by measuring basal insulin secretion and stimulated insulin release at different time points. The results revealed that microencapsulated pancreatic islets in the presence of bFGF demonstrated an increase in basal insulin secretion. Furthermore, microencapsulated pancreatic islets in the presence of bFGF demonstrated a marked stimulated insulin release and relative stability of stimulation indices (SI). The results in the perifusion study showed that microencapsulated pancreatic islets in the presence of bFGF maintained good glucose responsiveness over the course of culture period as well. These results indicate that bFGF has a beneficial effect on insulin secretion from microencapsulated pancreatic islets during in vitro culture. New strategies for preserving and improving function of microencapsulated pancreatic islets prior to transplantation may be developed by application of growth factors or other factors.

Animals↗

Effect and mechanism of coking residual ammonia water treating by flue gas.

The treatment of coking residual ammonia water has been a big difficult problem at home and abroad, and there is no breakthrough research achievement in the past. The invention patent "The method of treating all coking wastewater or treating coking residual ammonia water by flue gas" has been successfully used in Huaian Steel Works for high concentration and organic industry wastewater treatment. Not only can it realize the wastewater zero discharge, but also the wastewater treatment has an effect of de-sulfur and de-nitrogen for flue gas. So that the flue gas exhaust can meet the requirement of emission standard. The mass transfer and heat transfer, fly ash absorption and coagulation, acid and alkali neutralization reaction, catalysis oxidation and reduction reaction in flue gas would be the major factors.

Air Pollution↗