Distilling the neural correlates of consciousness

Solving the problem of consciousness remains one of the biggest challenges in modern science. One key step towards understanding consciousness is to empirically narrow down neural processes associated with the subjective experience of a particular content. To unravel these neural correlates of consciousness (NCC) a common scientific strategy is to compare perceptual conditions in which consciousness of a particular content is present with those in which it is absent, and to determine differences in measures of brain activity (the so called “contrastive analysis”). However, this comparison appears not to reveal exclusively the NCC, as the NCC proper can be confounded with prerequisites for and consequences of conscious processing of the particular content. This implies that previous results cannot be unequivocally interpreted as reflecting the neural correlates of conscious experience. Here we review evidence supporting this conjecture and suggest experimental strategies to untangle the NCC from the prerequisites and consequences of conscious experience in order to further develop the otherwise valid and valuable contrastive methodology

Local category-specific gamma band responses in the visual cortex do not reflect conscious perception

Which neural processes underlie our conscious experience? One theoretical view argues that the neural correlates of consciousness (NCC) reside in local activity in sensory cortices. Accordingly, local category-specific gamma band responses in visual cortex correlate with conscious perception. However, as most studies manipulated conscious perception by altering the amount of sensory evidence, it is possible that they reflect prerequisites or consequences of consciousness rather than the actual NCC. Here we directly address this issue by developing a new experimental paradigm in which conscious perception is modulated either by sensory evidence or by previous exposure of the images while recording intracranial EEG from the higher-order visual cortex of human epilepsy patients. A clear prediction is that neural processes directly reflecting conscious perception should be present regardless of how it comes about. In contrast, we observed that although subjective reports were modulated both by sensory evidence and by previous exposure, gamma band responses solely reflected sensory evidence. This result contradicts the proposal that local gamma band responses in the higher-order visual cortex reflect conscious perception

Esophageal Varices Bleeding in Portal Hypertension Due to Portal Vein and Splenic Vein Obstruction

Based on its relation to the liver sinusoid, increased pressure of portal vein can occur at three levels: presinusoid, sinusoid ,and postsinusoid. Obstruction of the presinusoid veins can be caused by extra- hepatic condition such as venous thrombosis. We reported a case of portal hypertension with esophageal varices bleeding was a result of obstruction due to thrombosis of the splenic vein and portal vein under hypercoagulant conditions due to thrombocytosis. The management of esophageal varices was sclerotherapy while for overcome the thrombosis the patient was given hydroxy urea

Impact of Age and Sex of Rocky Mountain Elk (\u3ci\u3eCervus elaphus nelson\u3c/i\u3e) on Follicle Counts From Rectal Mucosal Biopsies for Preclinical Detection of Chronic Wasting Disease

To determine if the number of rectal lymphoid follicles decreases with respect to age and sex relative to diagnosis of chronic wasting disease (CWD), rectal biopsies (n = 1,361) were taken from captive Rocky Mountain elk (Cervus elaphus nelsoni) at 4 ranches in the western United States between 2005 and 2008. Rectal tissues were stained with a monoclonal antibody (F99/97.6.1), which selectively stains the abnormal isoform of the prion protein associated with CWD of elk. The number of lymphoid follicles obtained from typical biopsy tissues decreased with the age of the animal. The acceptable number of lymphoid follicles for detection of CWD was not considered to be a problem in elk up to 8.5 years of age, but in elk over 8.5 years of age, the follicle count was considered to be low. Sex of the animal had no effect on the number of lymphoid follicles observed in each age group. Rectal biopsies were an accurate test to diagnose preclinical stages of CWD in elk but may be best suited to elk that are less then 8.5 years of age

Impact of Age and Sex of Rocky Mountain Elk (\u3ci\u3eCervus elaphus nelson\u3c/i\u3e) on Follicle Counts From Rectal Mucosal Biopsies for Preclinical Detection of Chronic Wasting Disease

To determine if the number of rectal lymphoid follicles decreases with respect to age and sex relative to diagnosis of chronic wasting disease (CWD), rectal biopsies (n = 1,361) were taken from captive Rocky Mountain elk (Cervus elaphus nelsoni) at 4 ranches in the western United States between 2005 and 2008. Rectal tissues were stained with a monoclonal antibody (F99/97.6.1), which selectively stains the abnormal isoform of the prion protein associated with CWD of elk. The number of lymphoid follicles obtained from typical biopsy tissues decreased with the age of the animal. The acceptable number of lymphoid follicles for detection of CWD was not considered to be a problem in elk up to 8.5 years of age, but in elk over 8.5 years of age, the follicle count was considered to be low. Sex of the animal had no effect on the number of lymphoid follicles observed in each age group. Rectal biopsies were an accurate test to diagnose preclinical stages of CWD in elk but may be best suited to elk that are less then 8.5 years of age

Human Blood Lipoprotein Predictions from ¹H NMR Spectra:Protocol, Model Performances, and Cage of Covariance

Lipoprotein subfractions are biomarkers for the early diagnosis of cardiovascular diseases. The reference method, ultracentrifugation, for measuring lipoproteins is time-consuming, and there is a need to develop a rapid method for cohort screenings. This study presents partial least-squares regression models developed using 1H nuclear magnetic resonance (NMR) spectra and concentrations of lipoproteins as measured by ultracentrifugation on 316 healthy Danes. This study explores, for the first time, different regions of the 1H NMR spectrum representing signals of molecules in lipoprotein particles and different lipid species to develop parsimonious, reliable, and optimal prediction models. A total of 65 lipoprotein main and subfractions were predictable with high accuracy, Q2 of >0.6, using an optimal spectral region (1.4-0.6 ppm) containing methylene and methyl signals from lipids. The models were subsequently tested on an independent cohort of 290 healthy Swedes with predicted and reference values matching by up to 85-95%. In addition, an open software tool was developed to predict lipoproteins concentrations in human blood from standardized 1H NMR spectral recordings

Dienogest alone or dienogest combined with estrogens in the treatment of ovarian endometriomas, that is the question. A retrospective cohort study

Purpose: to compare the effects of Dienogest 2 mg (D) alone or combined with estrogens (D + ethinylestradiol 0.03 mg, D + EE; D + estradiol valerate 1-3 mg, D + EV) in terms of symptoms and endometriotic lesions variations. Methods: This retrospective study included symptomatic patients in reproductive age with ultrasound diagnosis of ovarian endometriomas. Medical therapy for at least 12 months with D, D + EE or D + EV was required. Women were evaluated at baseline visit (V1) and after 6 (V2) and 12 months (V3) of therapy. Results: 297 patients were enrolled (156 in the D group, 58 in the D + EE group, 83 in the D + EV group). Medical treatment leaded to a significant reduction in size of endometriomas after 12 months, with no differences between the three groups. When comparing D and D + EE/D + EV groups, a significant decrease of dysmenorrhea was detected in the D group than in D + EE/D + EV group. Conversely, the reduction of dysuria was more significative in the D + EE/D + EV groups rather than in the D group. Regarding tolerability, treatment associated side effects were reported by 16.2% patients. The most frequent one was uterine bleeding/spotting, significantly higher in the D + EV group. Conclusion: Dienogest alone or associated with estrogens (EE/EV) seems to be equally effective in reducing endometriotic lesions mean diameter. The reduction of dysmenorrhea was more significative when D was administered alone, while dysuria seems to improve more when D is associated with estrogens