Search Results - (Author, Cooperation:D. S. Chen)

2014-11-28

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adult ; Aged ; Aged, 80 and over ; Antibodies, Monoclonal/adverse effects/*therapeutic use ; Antigens, CD274/*antagonists & inhibitors/metabolism ; Biomarkers/blood ; CTLA-4 Antigen/metabolism ; Chemokine CX3CL1/metabolism ; Clinical Protocols ; Disease-Free Survival ; Female ; *Gene Expression Regulation, Neoplastic ; Humans ; *Immunotherapy/adverse effects ; Lymphocytes, Tumor-Infiltrating/immunology ; Male ; Middle Aged ; Neoplasms/diagnosis/*therapy ; Treatment Outcome ; Young Adult

2014-11-28

Nature Publishing Group (NPG)

0028-0836

1476-4687

Biology

Chemistry and Pharmacology

Medicine

Natural Sciences in General

Physics

Adult ; Aged ; Aged, 80 and over ; Antibodies, Monoclonal/adverse effects/*therapeutic use ; Antigens, CD274/metabolism ; Female ; Humans ; *Immunotherapy ; Male ; Middle Aged ; Treatment Outcome ; Urinary Bladder Neoplasms/*therapy

2018-07-21

American Association for the Advancement of Science (AAAS)

2375-2548

Natural Sciences in General

0038-1098

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0006-291X

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Biology

Chemistry and Pharmacology

Physics

Electronic Resource

0165-4608

Elsevier Journal Backfiles on ScienceDirect 1907 - 2002

Medicine

Electronic Resource

1423-0127

Chronic type B hepatitis ; Mixed viral strains in acute exacerbations ; Hepatitis B virus reinfection

Springer Online Journal Archives 1860-2000

Biology

Medicine

Abstract Chronic hepatitis B virus (HBV) infections are frequently associated with exacerbations of hepatitis of which the majority are due to reactivation of viral activity. Variation in a viral genome during persistent infection has been shown to be a possible cause for reactivation. In this study, we have found another possible mechanism. HBV in a patient with repeated exacerbations was isolated at six different times during follow-up and was characterized by polymerase chain reaction and DNA sequencing. The first episode of exacerbation was accompanied with increased replication of an HBV strain. The second episode, however, was associated with the sudden appearance of an HBV strain that displayed enough sequence variations to warrant the designation as a separate strain. The results suggested a reinfection event by another independent HBV. Subsequent exacerbations were then related to coactivation of both viral stains. These observations provide significant information toward understanding the acute exacerbations of chronic type B hepatitis.

Electronic Resource

1432-0711

Key words: Hepatitis B virus – Genetic amniocentesis – Intrauterine infection

Springer Online Journal Archives 1860-2000

Medicine

Abstract. Sixty-seven pairs of mothers with hepatitis B virus (HBV) surface antigen (HBsAg) and their infants were divided into two study groups to determine the effect of amniocentesis on intrauterine HBV infection. In the first study group (35 pairs), the infant's HBsAg status in cord blood was studied and the results were compared with those obtained in the cord blood from 65 infants born to HBsAg-positive women who did not have an amniocentesis. In the second study group (32 pairs), the HBV status of the infants was studied at the age of three months to five years and compared with the HBV status of 3,454 infants in the National HBV Prevention Program. In the first study group, one sample (2.9%) was weakly positive for HBsAg; while in the first control group, two (3.1%) were positive. In the second study group, three (10%) infants were positive for HBsAg. The failure rates of immunoprophylaxis in the second study and control groups were similar (9.4% vs 11% for HBsAg carrier mothers; 30% vs 14% for HBe antigen-positive carrier mothers). This suggested that genetic amniocentesis did not increase the risk of intrauterine HBV infection.

Electronic Resource

1432-0711

Hepatitis B virus ; Genetic amniocentesis ; Intrauterine infection

Springer Online Journal Archives 1860-2000

Medicine

Abstract Sixty-seven pairs of mothers with hepatitis B virus (HBV) surface antigen (HBsAg) and their infants were divided into two study groups to determine the effect of amniocentesis on intrauterine HBV infection. In the first study group (35 pairs), the infant's HBsAg status in cord blood was studied and the results were compared with those obtained in the cord blood from 65 infants born to HBsAg-positive women who did not have an amniocentesis. In the second study group (32 pairs), the HBV status of the infants was studied at the age of three months to five years and compared with the HBV status of 3,454 infants in the National HBV Prevention Program. In the first study group, one sample (2.9%) was weakly positive for HBsAg; while in the first control group, two (3.1%) were positive. In the second study group, three (10%) infants were positive for HBsAg. The failure rates of immunoprophylaxis in the second study and control groups were similar (9.4% vs 11% for HBsAg carrier mothers; 30% vs 14% for HBe antigen-positive carrier mothers). This suggested that genetic amniocentesis did not increase the risk of intrauterine HBV infection.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  The pathogenesis and replication sites of GB virus-C/hepatitis G virus (GBV-C/HGV) in humans remain unclear. The presence of GBV-C/HGV and hepatitis C virus (HCV) RNA sequences in matched serum, peripheral blood mononuclear cells (PBMC) and liver samples in 10 patients with GBV-C/HGV infection, 8 of whom were coinfected with HCV was explored. Positive- and negative-strand GBV-C/HGV and HCV RNA were detected by strand-specific reverse-transcription polymerase chain reaction (RT-PCR), and virus titers were quantified by competitive PCRs. Positive-strand GBV-C/HGV RNA was detected in 7 of 10 PBMC samples of the patients with serum GBV-C/HGV RNA, but negative-strand GBV-C/HGV RNA was not found in these cells. Positive-strand GBV-C/HGV RNA was found in 9 liver samples, and 2 (22%) of them also had negative strand. In contrast, negative-strand HCV RNA was frequently found in PBMC and liver samples. A positive correlation between the titer of viral RNA in liver tissue and that in serum sample was demonstrated in HCV infection, but not in GBV-C/HGV infection. These findings suggest that liver and PBMC are not the major replication sites for GBV-C/HGV and that GBV-C/HGV is not a primary hepatotropic virus.

Electronic Resource

1432-8798

Springer Online Journal Archives 1860-2000

Medicine

Summary.  We found that patients with dual HBV and GBV-C/HGV infection had comparable serum HBV DNA positivity and mean virus concentration compared with age-matched HBV carriers, and those with triple infection had a significantly lower HBV DNA positivity. Serum HCV RNA positivity and mean virus titer were similar between HCV carriers with or without GBV-C/HGV co-infection, and those with GBV-C/HGV co-infection seemed to have a lower serum ALT level. These data suggest that GBV-C/HGV infection exerts no significant suppression on levels of chronic hepatitis B or hepatitis C viremia.

Electronic Resource

1435-4373

Springer Online Journal Archives 1860-2000

Medicine

Abstract To evaluate the sensitivity of a polymerase chain reaction (PCR) assay using nested primers in detectingHelicobacter pylori, gastric tissue biopsy specimens were collected on endoscopy from 17 patients with a duodenal ulcer. DNA was extracted by phenol/chloroform treatment or boiling in water, and then subjected to a nested PCR using two primer pairs from the urease gene ofHelicobacter pylori. Fourteen of the 17 patients were positive forHelicobacter pylori using DNA samples extracted by either method. The PCR results correlated well with the results of an enzyme immunoassay to detect IgG antibody. However, there were two culture negative patients. The three PCR negative patients were both culture negative and serologically negative. DNA from 9 of the 14 patients was randomly selected and subjected to semiquantification by serial dilutions, and then PCR. The results showed that phenol/chloroform extraction yielded 10–1000 times more DNA than the boiling method. It is concluded that the PCR assay is a rapid and sensitive method for detectingHelicobacter pylori, and that phenol/chloroform extraction is superior to simple boiling in obtaining DNA samples for PCR.

Electronic Resource

1435-1528

Springer Online Journal Archives 1860-2000

Chemistry and Pharmacology

Physics

Summary In this paper the presence of a ped structure in clay formation is recognized. The total response deformation representing the macro-rheological behaviour accounts for the integral effect of individual ped performance characteristics. The summation orVolterra-Boltzmann integral accounting for the different structural strengths of the various peds is introduced in the analysis, incorporating thereby the probability of occurrence of each structural state. The utilization of this probability is likened in essence to a weighing factor of the contribution of each structural state, leading to the derivation of the mathematical expectation of the total deformation.

Electronic Resource

0032-3888

Chemistry ; Chemical Engineering

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

Unsaturated polyesters were prepared by one-stage melt condensation of maleic anhydride, phthalic anhydride, propylene glycol, and poly(ethylene glycol)s with different molecular weight, and the properties of their castings from styrenated resins were investigated. Tensile and flexural properties decrease with the increase of molecular weight of poly(ethylene glycol), but impact strength, elongation, and water absorption have an inverse effect. This study improves the understanding of the effect of chain length of poly(ethylene glycol) in unsaturated polyester on the properties of its castings.

8 Ill.

Electronic Resource

0021-8995

Chemistry ; Polymer and Materials Science

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics

Physics

The dynamic mechanical properties, transition behavior, and morphology of polycarbonate (PC)-polyurethane (PU) semi-interpenetrating polymer networks (semi-IPNs) and linear blends were studied by means of Rheovibron, differential scanning calorimetry (DSC), and transmission electron microscopy (TEM). Two glass transition temperatures corresponding to polycarbonate and polyurethane were observed and microphase separation was further evident with TEM. In PC/PU semi-IPNs, two glass transition temperatures were shifted inwardly indicating that the interpenetrating network of polyurethane increases the mutual miscibility of PC and PU. The average phase domain was 500Å in semi-IPNs and the phase domains were in the range 1000-6000 Å in linear blends of the corresponding polymers. The compatibilities of PC and PU were greatly influenced by the molecular weight of polyols in PU prepolymer and the ratio of NCO/OH; lower molecular weight polyols and higher NCO/OH ratio resulted in better compatibility, and finer phase domains in PC and PU linear blends and semi-IPNs.

7 Ill.

Electronic Resource