Haiou Yang

Publications of Haiou Yang

• Sedentary work, low physical job demand, and obesity in US workers.

  Authors: BongKyoo Choi, Peter L Schnall, Haiou Yang, Marnie Dobson, Paul Landsbergis, Leslie Israel, Robert Karasek, Dean Baker

  American journal of industrial medicine. 11/2010; 53(11):1088-101.

  Little is known about the role of low physical activity at work (sedentary work or low physical job demand) in the increasing prevalence of obesity of US workers. This cross-sectional and secondaryLittle is known about the role of low physical activity at work (sedentary work or low physical job demand) in the increasing prevalence of obesity of US workers. This cross-sectional and secondary data analysis included 1,001 male and 1,018 female workers (age range: 32-69) from the National Survey of Midlife Development in the United States (MIDUS) II study (2004-2006). Sedentary work and physical job demand were measured by questionnaire items. Total obesity (based on body mass index) and central obesity (based on waist circumference) were defined using WHO criteria. After controlling for covariates (socio-demographic, psychosocial working conditions, health status, and health behaviors), sedentary work, low physical job demand, or their combination increased the risk for total and central obesity in male workers, particularly when they worked longer than 40 hr per week. Sedentary work marginally increased the risk for total and central obesity in female workers. Low physical activity at work is a significant risk factor for total and central obesity in middle-aged US male workers.

• Psychosocial working conditions and active leisure-time physical activity in middle-aged us workers.

  Authors: Bongkyoo Choi, Peter L Schnall, Haiou Yang, Marnie Dobson, Paul Landsbergis, Leslie Israel, Robert Karasek, Dean Baker

  International journal of occupational medicine and environmental health. 10/2010; 23(3):239-53.

  This study was to examine whether psychosocial work characteristics such as job control, psychological job demands, and their combinations are associated with leisure-time physical activity (LTPA) inThis study was to examine whether psychosocial work characteristics such as job control, psychological job demands, and their combinations are associated with leisure-time physical activity (LTPA) in US workers. 2019 workers (age range: 32 to 69) from the National Survey of Midlife Development in the United States (MIDUS) II study (2004-2006) were chosen for this cross-sectional study. Job control and job demands were measured by standard questionnaire items. Active LTPA was defined as "moderate or vigorous" level of physical activity. After controlling for covariates (e.g., age, race, education, income, physical effort at work, obesity, and alcohol consumption), high job control was associated with active LTPA. Active jobs (high control and low demands) and low-strain jobs (high control and high demands), compared to passive jobs (low control and low demands), increased the odds for active LTPA. The associations varied by sex and education level. Job demands alone were not associated with active LTPA. Having on-the-job learning opportunities and decision authority on their tasks may be conducive to active LTPA in middle-aged US workers.

• Purification of human immunoglobulin G via Fc-specific small peptide ligand affinity chromatography.

  Authors: Haiou Yang, Patrick V Gurgel, Ruben G Carbonell

  Journal of chromatography. A. 01/2009;

  Chromatographic resins of a family of linear Fc-binding hexamer peptides (HWRGWV, HYFKFD, and HFRRHL) exhibited the ability to selectively adsorb and isolate human IgG (hIgG) from complete mammalianChromatographic resins of a family of linear Fc-binding hexamer peptides (HWRGWV, HYFKFD, and HFRRHL) exhibited the ability to selectively adsorb and isolate human IgG (hIgG) from complete mammalian cell culture medium (cMEM). Among them, the HWRGWV resin with a peptide density of 0.08mequiv./g of resin was able to purify hIgG from cMEM with both purity and yield as high as 95%, comparable to Protein A and A2P agarose gels. The influences of N-terminal acetylation of the HWRGWV resin, ligand density on the resin, initial hIgG concentration, and temperature on IgG isolation were also investigated. The results indicate that these small peptide ligands, especially HWRGWV, offer a potential alternative to the use of Protein A or Protein G for large scale affinity chromatography.

• Work hours and self-reported hypertension among working people in California.

  Authors: Haiou Yang, Peter L Schnall, Maritza Jauregui, Ta-Chen Su, Dean Baker

  Hypertension. 11/2006; 48(4):744-50.

  Among the risk factors for hypertension, stress, especially work stress, has drawn increasing attention. Another potential work-related risk factor for hypertension identified in the past few yearsAmong the risk factors for hypertension, stress, especially work stress, has drawn increasing attention. Another potential work-related risk factor for hypertension identified in the past few years is work hours. This article presents an analysis of work hours and self-reported hypertension among the working population in the state of California. The data set used for this study comes from the Public Use File of the 2001 California Health Interview Survey. The logistic regression analysis shows a positive association between hours worked per week and likelihood of having self-reported hypertension. Compared with those working between 11 and 39 hours per week, individuals working 40 hours per week were 14% (95% CI: 1.01 to 1.28) more likely to report hypertension, those who worked between 41 and 50 hours per week were 17% (95% CI: 1.04 to 1.33) more likely to report hypertension, and those who worked >or=51 hours per week were 29% (95% CI: 1.10 to 1.52) more likely to report hypertension after controlling for various potentially confounding variables, including demographic and biological risk factors and socioeconomic status. This analysis provides evidence of a positive association between work hours and hypertension in the California working population.

• Binding site on human immunoglobulin G for the affinity ligand HWRGWV.

  Authors: Haiou Yang, Patrick V Gurgel, D Keith Williams, Benjamin G Bobay, John Cavanagh, David C Muddiman, Ruben G Carbonell

  Journal of molecular recognition : JMR. 23(3):271-82.

  Affinity ligand HWRGWV has demonstrated the ability to isolate human immunoglobulin G (hIgG) from mammalian cell culture media. The ligand specifically binds hIgG through its Fc portion. This workAffinity ligand HWRGWV has demonstrated the ability to isolate human immunoglobulin G (hIgG) from mammalian cell culture media. The ligand specifically binds hIgG through its Fc portion. This work shows that deglycosylation of hIgG has no influence on its binding to the HWRGWV ligand and the ligand does not compete with Protein A or Protein G in binding hIgG. It is suggested by the mass spectrometry (MS) data and docking simulation that HWRGWV binds to the pFc portion of hIgG and interacts with the amino acids in the loop Ser383-Asn389 (SNGQPEN) located in the C(H)3 domain. Subsequent modeling has suggested a possible three-dimensional minimized solution structure for the interaction of hIgG and the HWRGWV ligand. The results support the fact that a peptide as small as a hexamer can have specific interactions with large proteins such as hIgG.