Induction of HSP27 nuclear immunoreactivity during stress is modulated by vitamin C

For the investigation of the skin irritancy potential of chemicals in an in vitro model it is necessary to have sensitive endpoints that predict the effects of those compounds on native human skin. Recently, we have identified that 27-kDa heat shock protein (HSP27) can serve as a sensitive marker of skin irritation, as exposure of human skin to sodium lauryl sulfate (SLS) both in vitro and in vivo induced relocalization of HSP27 from the cytoplasm to the cell nucleus. The aim of the present study was to determine whether nuclear localization of HSP27 could be used as a parameter for evaluation of potential skin irritants in screening assays in vitro. For this purpose, human skin equivalent consisting of epidermis reconstructed on de-epidermized dermis was exposed to SLS or UV light. Stress-induced nuclear relocalization of HSP27 was observed in excised skin exposed to SLS or UV light and in reconstructed epidermis only when the latter was generated in the absence of vitamin C. The omission of vitamin C results in an impaired barrier function. In the presence of vitamin C, however, the barrier function was comparable with excised skin, suggesting that vitamin C may control the response to stress in the reconstructed epidermis. Besides the presence of vitamin C, the response of skin equivalents may strongly depend on other conditions under which they are generated, because the stress-induced HSP27 relocalization was not detected in the commercially available epidermal kit EpiDerm. The results of the present study show that HSP27 nuclear staining can serve as a sensitive marker for skin irritation or cellular stress in excised skin as well as in certain well-characterized human skin equivalents in vitro.     

Peak oxygen intake and cardiac mortality in women referred for cardiac rehabilitation

OBJECTIVES: This study investigated the prognostic importance of measured peak oxygen intake (VO(2peak)) in women with known coronary heart disease referred for outpatient cardiac rehabilitation. BACKGROUND: Exercise capacity is a powerful predictor of prognosis in men with known or suspected coronary disease. Similar findings are described in women, but fewer studies have utilized measured VO(2peak), the most accurate measure of exercise capacity. METHODS: A single-center design took data from 2,380 women, age 59.7 +/- 9.5 years (1,052 myocardial infarctions, 620 coronary bypass procedures, and 708 with proven ischemic heart disease), who underwent cardiorespiratory exercise testing. They were followed for an average of 6.1 +/- 5 years (median 4.5 years, range 0.4 to 25 years) until cardiac and all-cause death. RESULTS: We recorded 95 cardiac deaths and 209 all-cause deaths. Measured VO(2peak) was an independent predictor of risk, values > or =13 ml/kg/min (3.7 multiples of resting metabolic rate) conferring a 50% reduction in cardiac mortality (hazard ratio [HR] 0.5, p = 0.001). Considered as a continuous variable, a 1 ml/kg/min advantage in initial VO(2peak) was associated with a 10% lower cardiac mortality. Adverse predictors were diabetes (HR 2.73, p = 0.0005) and antiarrhythmic therapy (HR 3.93, p = 0.0001). CONCLUSIONS: As in men, measured VO(2peak) is a strong independent predictor of cardiac mortality in women referred for cardiac rehabilitation.     

Development of a Generic Anti-PEG Antibody Assay Using BioScale’s Acoustic Membrane MicroParticle Technology

Immunogenicity testing for PEGylated biotherapeutics should include methods to detect both anti-protein and anti-PEG antibodies (anti-PEG). Although some methods have been published for the detection of anti-PEG antibodies, the information is incomplete and, in some cases, reagents used (such as Tween-20) are known to interfere with detection. This rapid communication describes the use of BioScale’s Acoustic Membrane MicroParticle (AMMP®) technology using the ViBE® Workstation to measure anti-PEG antibodies in human serum samples. Briefly, a sample spiked with monoclonal human IgG anti-PEG antibody is diluted in buffer and incubated with paramagnetic beads coated with linear chain mPEG to capture anti-PEG antibodies. The complex is then captured on an acoustic membrane coated with Protein A. The change in mass on the membrane caused by the binding of the complex to the membrane results in a signal proportional to the mass of anti-PEG antibodies. The data indicate that an assay with a sensitivity of less than 1000 ng/mL for IgG is achievable. This level of sensitivity is better than current published reports on IgG anti-PEG antibody detection.KEY WORDS: acoustic membrane microparticle technology, anti-peg antibodies, emerging technology, immunogenicity assays, pegylated biotherapeutics     

Low and high circulating cortisol levels predict mortality and cognitive dysfunction early after stroke

OBJECTIVE: Elevated cortisol levels are associated with confusion and poor outcome after stroke. Dehydroepiandrosterone sulphate (DS), the most abundant adrenal androgen may act as an anti-glucocorticoid. An altered regulation of these steroids may affect numerous brain functions, including neuronal survival. The purpose of this study was to investigate serum cortisol and DS levels and the cortisol/DS ratio early after stroke and relate our findings to the presence of disorientation and mortality. DESIGN: Patients with acute ischaemic stroke (n = 88, 56 men and 32 women) admitted to a stroke unit were investigated with repeated clinical assessments and scores for degree of confusion, extent of paresis and level of functioning. Serum cortisol (C) and DS were measured on day 1 and/or day 4. Data for 28-day and 1-year mortality are presented. A control group of 65 age-matched healthy individuals was used. Multivariate analyses of mortality rates in the different tertiles or sixtiles of serum cortisol were performed with logistic regression, adjusting for age, sex, diabetes and level of consciousness. RESULTS: There was no difference in serum cortisol levels on day 1 for stroke patients when compared with control group values. Initial cortisol levels were significantly higher in the patients with acute disorientation versus orientated patients (P < 0.05). Cortisol levels on day 1 were an independent predictor of 28-day mortality, and patients with low cortisol levels (<270 nmol L(-1)) and increased levels (>550 nmol L(-1)) both had an increased 1-year mortality. DS levels on day 1 were significantly elevated in stroke patients. CONCLUSION: Hypercortisolism is associated with cognitive dysfunction early after ischaemic stroke. High and low circulating cortisol levels are associated with increased mortality after stroke. DS levels were not associated with clinical outcome.