Prostanoids are not involved in postocclusive reactive hyperaemia in human skin

Several mediators contribute to postocclusive reactive hyperaemia (PORH) in the skin, including sensory nerves and endothelium‐derived hyperpolarizing factors. The main objective of this study was to investigate the specific involvement of prostanoids in human skin PORH. We tested the effect of the inhibition of cyclo‐oxygenases (COX) by 4 mm ketoprofen, infused through microdialysis fibers inserted into the healthy volunteers forearm skin, following 5 min brachial artery occlusion. Skin microvascular blood flux was recorded using two‐dimensional Laser Speckle Contrast Imaging. Maximal cutaneous vascular conductance (CVC_max) was obtained following the perfusion of 29 mm sodium nitroprusside. A systematic review of the effects of COX inhibitors on skin peak PORH was also performed. We observed no significant difference between ketoprofen and placebo for the PORH peak (78 ± 8 and 71 ± 19% CVC_max, respectively) and area under the curve (2951 ± 721 and 2490 ± 936% CVC_max.s). A meta‐analysis showed a substantial heterogeneity between studies, with overall a neutral effect of COX inhibition on peak PORH. Cyclo‐oxygenase inhibition does not alter skin PORH, suggesting no involvement of prostanoids in cutaneous postocclusive vasodilatation in healthy humans.     

Cognitive functions in abstinent alcohol-dependent patients

The objective of this cross-sectional study was to compare cognitive functioning of abstaining alcohol-dependent (AD) male patients and healthy controls as well as to investigate whether their cognitive performance varied by abstinence length. Forty-two maintaining abstinent (AD) patients and 34 healthy controls were examined. Tests from the Cambridge Neuropsychological Test Automated Battery (CANTAB) were used to assess cognitive functions. Differences in cognitive performance were found between AD patients and healthy controls. Nonverbal tasks in cognitive domains such as attention, visual memory and working memory were impaired in AD patients who presented deficits in visual episodic memory, had slower reaction time and reduced working memory span. Patients who were abstinent for less than one year made more errors in both attentional set shifting and working memory tests than healthy controls and patients with longer durations of abstinence. Impairments identified in multiple cognitive domains in abstinent alcohol-dependent subjects suggest functional deficits in extensive brain networks connecting interrelated brain structures. Attentional control and spatial working memory were less impaired in those AD patients who maintained abstinence for at least one year.