Gamma band activity in the RAS-intracellular mechanisms

Gamma band activity participates in sensory perception, problem solving, and memory. This review considers recent evidence showing that cells in the reticular activating system (RAS) exhibit gamma band activity, and describes the intrinsic membrane properties behind such manifestation. Specifically, we discuss how cells in the mesopontine pedunculopontine nucleus, intralaminar parafascicular nucleus, and pontine SubCoeruleus nucleus dorsalis all fire in the gamma band range when maximally activated, but no higher. The mechanisms involve high-threshold, voltage-dependent P/Q-type calcium channels, or sodium-dependent subthreshold oscillations. Rather than participating in the temporal binding of sensory events as in the cortex, gamma band activity in the RAS may participate in the processes of preconscious awareness and provide the essential stream of information for the formulation of many of our actions. We address three necessary next steps resulting from these discoveries: an intracellular mechanism responsible for maintaining gamma band activity based on persistent G-protein activation, separate intracellular pathways that differentiate between gamma band activity during waking versus during REM sleep, and an intracellular mechanism responsible for the dysregulation in gamma band activity in schizophrenia. These findings open several promising research avenues that have not been thoroughly explored. What are the effects of sleep or REM sleep deprivation on these RAS mechanisms? Are these mechanisms involved in memory processing during waking and/or during REM sleep? Does gamma band processing differ during waking versus REM sleep after sleep or REM sleep deprivation?     

Non-apolipoprotein E and apolipoprotein E genetics of sporadic Alzheimer's disease

The genetic epidemiology of sporadic Alzheimer's disease (SAD) remains a very active area of research, making it one of the most prolifically published areas in medicine and biology. Numerous putative candidate genes have been proposed. However, with the exception of apolipoprotein E (APOE), the only confirmed genetic risk factor for SAD, all the other data appear to be not consistent. Nevertheless, the genetic risk for SAD attributable to the APOE gene in the general population is 20–70%, providing a strong evidence for the existence of additional genetic risk factors. The first part of the present article was dedicated to non-APOE genetics of SAD, reviewing chromosomes-by-chromosomes the available data concerning the major candidate genes. The second part of this article focused on some recently discovered aspects of the APOE polymorphism and their implications for SAD. An attempt to identify the future directions for non-APOE genetic research in SAD was also discussed.     

Leucocyte interferon-alpha for patients with chronic hepatitis C intolerant to other alpha-interferons

Background

Alpha-interferon (α-IFN) is the treatment of choice for chronic hepatitis C but most patients experience adverse effects which sometimes lead to the suspension of therapy. Recently, higher doses of α-IFN or prolonged therapy have increased the number of cases of intolerance.

Study Design

In this open study we evaluated the efficacy and safety of leucocyte interferon-alpha (IFNα) [6MU three times a week] in 43 patients with chronic hepatitis C who had been intolerant to previous treatment courses with recombinant or lymphoblastoid IFNα. All patients were treated for 6 months and followed-up for an additional 6 months. End of treatment responders were patients in whom hepatitis C virus (HCV)-RNA had been eradicated from the blood by the end of treatment, sustained responders were those patients who maintained negative HCV-RNA at the end of follow-up, and the remaining patients were considered non-responders. Adverse effects were monitored by interviews, laboratory and clinical examinations.

Results

Five patients (11.6%) discontinued the treatment, four due to the reappearance of previous adverse effects, and one due to an ex novo adverse effect. In six patients the dose had to be halved. At the end of treatment 11 patients (25.6%) had negative serum HCV-RNA. After discontinuation of therapy, disease flared in four patients, thus seven patients were sustained responders.

Conclusions

This study shows that leucocyte IFNα at a dose of 6MU three times a week is well tolerated in patients previously intolerant to recombinant or lymphoblastoid IFNα, allowing a high percentage of them to complete a course of treatment in terms of duration and dose.     

Hepatitis C virus superinfection in hepatitis B virus chronic carriers: a reciprocal viral interaction and a variable clinical course.

BACKGROUND: The virological and clinical impact of hepatitis C virus (HCV) superinfection in chronic hepatitis B virus (HBV) carriers has been poorly characterized. OBJECTIVE: To evaluate the viral interaction, clinical presentation and course of the disease in four HBsAg/HBV-DNA positive chronic hepatitis patients who developed acute HCV infection. STUDY DESIGN: To evaluate clinical, virological and laboratory data for at least 6 months from the onset of acute HCV infection in patients with chronic HBV infection. RESULTS: Three patients with acute HCV infection had a normal clinical course, but the remaining patient had severe disease with ascites and a marked decrease in prothrombin activity. In all cases, plasma HBV-DNA, which had been detectable prior to the HCV infection, was no longer detectable when the acute HCV infection occurred. The inhibition exerted by HCV on HBV-DNA persisted throughout the follow-up period in three patients, but was temporary in the one patient who experienced an acute exacerbation of chronic HBV infection. HCV-RNA became persistently undetectable in two patients and reduced to low levels in the other two. CONCLUSIONS: Acute HCV infection in the four HBV chronic carriers was characterized by a reciprocal inhibition of HBV-HCV genomes and, in one case, by a severe course of disease.     

IL-2, TNF-alpha, and leptin: local versus systemic concentrations in NSCLC patients

One recent line of cancer research shows increasing interest for biological factor such as IL-2, TNF-alpha, and leptin, which have been found to participate in the development and progression of non-small cell lung cancer (NSCLC). The aim of this study was to measure IL-2, TNF-alpha, and leptin concentrations in the airways and in the systemic circle of patients with NSCLC, investigating the role of these factors in the lung tumors. We enrolled 32 patients (17 men, 71 +/- 7 years) with a histological diagnosis of NSCLC and 20 healthy ex-smoker controls, negative for computed tomography of the chest (14 men, 69 +/- 8 years). IL-2, TNF-alpha, and leptin levels were measured in the serum, the urine, the bronchoalveolar lavage, the induced sputum, and exhaled breath condensate (EBC) of patients enrolled by means of a specific enzyme immunoassay kit. Higher concentrations of IL-2, TNF-alpha and leptin were found in NSCLC patients than in controls (p < 0.0001). A statistically significant increase of IL-2, TNF-alpha, and leptin concentrations was observed in patients from stage I to stage III of NSCLC. These findings suggest that IL-2, TNF-alpha, and the leptin play an important role in the cancerogenesis of NSCLC. Their measure in the EBC could be proposed as noninvasive markers for an early detection of NSCLC and in the follow-up of this tumor.     

Headache and anxiety–depressive disorder comorbidity: the HADAS study

Neurological Sciences - Psychiatric comorbidity (prevalence and types) was tested in a naturalistic sample of adult patients with pure migraine without aura, and in two control groups of patients,...     

Validation of AIDA Cefalee,a computer-assisted diagnosis database for the management of headache patients

Neurological Sciences - AIDA Cefalee is a database for the management of headache patients developed on behalf of the Italian Neurological Association for Headache Research (ANIRCEF). The system...