Reduction of severe bovine serum associated matrix effects on carboxymethylated dextran coated biosensor surfaces

Surface plasmon resonance (SPR) based biosensor technology has been widely used in life science research for many applications. While the advantages of speed, ruggedness, versatility, sensitivity and reproducibility are often quoted, many researchers have experienced severe problem of non-specific binding (NSB) to chip surfaces when performing analysis of biological samples Such as bovine serum. Using the direct measurement of the bovine protein leptin, present in bovine serum samples as a model, a unique buffering system has been developed and optimised which was able to significantly reduce the non-specific interactions of bovine serum components with the carboxymethyl dextran chip (CM5) surface on a Biacore SPR The developed NSB buffering system comprised of HBS-EP buffer, containing 0.5 M NaCl, 0.005% CM-dextran pH 9.0. An average NSB reduction (n = 20) of 85.9% and 87.3% was found on an unmodified CM5 surface and a CM5 with bovine leptin immobilised on the chip surface, respectively. A reduction in NSB of up to 94% was observed on both surfaces. The concentration of the constitutive components and pH of the buffer were crucial in achieving this outcome. (C) 2008 Elsevier B.V. All rights reserved.

Maternal Glucose at 28 Weeks of Gestation Is Not Associated With Obesity in 2-Year-Old Offspring:The Belfast Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Family Study

OBJECTIVE:Diabetes during pregnancy is a strong risk factor for obesity in the offspring, but the age at which this association becomes apparent is unknown. The purpose of this study was to examine the relation of glycemia during pregnancy with anthropometry in offspring of nondiabetic pregnant women from the Belfast U.K. center of the multinational Hyperglycemia and Adverse Pregnancy Outcome (HAPO) Study.
RESEARCH DESIGN AND METHODS: Women from the HAPO Study were invited to participate in follow-up of their offspring aged 2 years. Measurements included height, weight, and thickness of triceps, subscapular, and suprailiac skinfolds. RESULTS: A total of 1,165 offspring (73% of eligible children; 598 boys and 567 girls) were seen from ages 22-30 completed months. The only association that reached statistical significance was between categories of maternal 1-h glucose and BMI Z score =85th percentile at 2 years (P = 0.017). Overall the correlations between maternal glucose during pregnancy and BMI Z score at age 2 years were weak (fasting glucose r = 0.05, P = 0.08; 1-h glucose r = 0.04, P = 0.22; 2-h glucose r = 0.03, P = 0.36; and area under the curve for glucose r = 0.04, P = 0.18).
CONCLUSIONS: This study found little association between maternal glucose during pregnancy and obesity in the offspring at this young age. These findings are not unexpected given that study results for young offspring whose mothers had diabetes during pregnancy were indistinguishable from those for normal offspring at this age. It will be interesting to see whether, as these children age, maternal glucose during pregnancy in the ranges included in the HAPO Study will be associated with obesity in their children. © 2010 by the American Diabetes Association.

Elucidating the molecular physiopathology of acute respiratory distress syndrome in severe acute respiratory syndrome patients

Acute respiratory distress syndrome (ARDS) is a severe form of acute lung injury. It is a response to various diseases of variable etiology, including SARS-CoV infection. To date, a comprehensive study of the genomic physiopathology of ARDS (and SARS) is lacking, primarily due to the difficulty of finding suitable materials to study the disease process at a tissue level (instead of blood, sputa or swaps). Hereby we attempt to provide such study by analyzing autopsy lung samples from patient who died of SARS and showed different degrees of severity of the pulmonary involvement. We performed real-time quantitative PCR analysis of 107 genes with functional roles in inflammation, coagulation, fibrosis and apoptosis: some key genes were confirmed at a protein expression level by immunohistochemistry and correlated to the degree of morphological severity present in the individual samples analyzed. Significant expression levels were identified for ANPEP (a receptor for CoV), as well as inhibition of the STAT1 pathway, IFNs production and CXCL10 (a T-cell recruiter). Other genes unassociated to date with ARDS/SARS include C1Qb, C5R1, CASP3, CASP9, CD14, CD68, FGF7, HLA-DRA, ICF1, IRF3, MALAT-1, MSR1, NFIL3, SLPI, USP33, CLC, GBP1 and TACI. As a result, we proposed to therapeutically target some of these genes with compounds such as ANPEP inhibitors, SLPI and dexamethasone. Ultimately, this study may serve as a model for future, tissue-based analyses of fibroinflammatory conditions affecting the lung. (C) 2009 Elsevier B.V. All rights reserved.

Recruitment bias and clinical characterstics of participants with severe cerebral palsy in a cross-sectional survey

Aim.  This article is a report of recruitment bias in a sample of 5–25-year-old patients with severe cerebral palsy.

Background.  The way in which study participants are recruited into research can be a source of bias.

Method.  A cross-sectional survey of 5–25-year-old patients with severe cerebral palsy using standardized questionnaires with parents/carers was undertaken in 2007/2008. A case register was used as the sampling frame, and 260 families were approached: 178/260 (68%) responded and 82/260 families never replied (non-respondents). Among responders: 127/178 (71%) opted in to the study, but only 123/127 were assessed, and 82/178 were opted out (or refused). Multivariable logistic regression giving odds ratios was used to study the association between participant characteristics and study outcomes (responders vs. non-responders; opting in vs. opting out; assessed vs. eligible, but not assessed).

Results.  Responders (compared with non-responders) were significantly more likely to have a family member with cerebral palsy who was male and resident in more affluent areas. Families who opted in (compared with those opting out and refusing) were more likely to have a family member with cerebral palsy and intellectual impairment and to reside in certain geographical areas. Families who were actually assessed (compared with all eligible, but not assessed) were more likely to have a family member with cerebral palsy and intellectual impairment.

Conclusion.  Several sources of bias were identified during recruitment for this study. This has implications for the interpretation and conclusions of surveys of people with disabilities and complex needs.

Referral to an Extracorporeal Membrane Oxygenation Center and Mortality Among Patients With Severe 2009 Influenza A(H1N1)

Context Extracorporeal membrane oxygenation (ECMO) can support gas exchange in patients with severe acute respiratory distress syndrome (ARDS), but its role has remained controversial. ECMO was used to treat patients with ARDS during the 2009 influenza A(H1N1) pandemic.