Feature selection for structure-activity correlation using binary particle swarms

We present a new feature selection algorithm for structure-activity and structure-property correlation based on particle swarms. Particle swarms explore the search space through a population of individuals that adapt by returning stochastically toward previously successful regions, influenced by the success of their neighbors. This method, which was originally intended for searching multidimensional continuous spaces, is adapted to the problem of feature selection by viewing the location vectors of the particles as probabilities and employing roulette wheel selection to construct candidate subsets. The algorithm is applied in the construction of parsimonious quantitative structure-activity relationship (QSAR) models based on feed-forward neural networks and is tested on three classical data sets from the QSAR literature. It is shown that the method compares favorably with simulated annealing and is able to identify a better and more diverse set of solutions given the same amount of simulation time.     

The diagnostic validity of the Athens Insomnia Scale

OBJECTIVE: To provide documentation for the diagnostic validity of the Athens Insomnia Scale (AIS), a self-assessment psychometric tool which has previously shown high consistency, reliability and external validity for the evaluation of the intensity of sleep difficulty. METHODS: The AIS was administered to a total of 299 subjects (105 primary insomniacs, 100 psychiatric outpatients, 44 psychiatric inpatients and 50 nonpatient controls) who were also assessed for the ICD-10 diagnosis of "nonorganic insomnia" blindly in terms of the AIS scores. RESULTS: 176 subjects were identified as insomniacs and 123 as noninsomniacs. Logistic regression of AIS total score against the ICD-10 diagnosis of insomnia demonstrated that a score of 6 is the optimum cutoff based on the balance between sensitivity and specificity. When diagnosing individuals with a score of 6 or higher as insomniacs, the scale presents with 93% sensitivity and 85% specificity (90% overall correct case identification). For this cutoff score, in the general population, the scale has a positive predictive value (PPV) of 41% and a negative predictive value (NPV) of 99%. For the same cutoff score, among unselected psychiatric patients, the PPV was found to be 86% and the NPV 92%. Other cutoff scores can be also considered, however, depending on the importance of avoiding false positive or false negative results; for example, for a cutoff score of 10, the PPV in the general population reaches about 90% without the NPV becoming lower than 94%. CONCLUSION: The AIS can be utilized in clinical practice and research, not only as an instrument to measure the intensity of sleep-related problems, but also as a screening tool in reliably establishing the diagnosis of insomnia.     

Total and corrected antioxidant capacity in hemodialyzed patients

Background  

Oxidative stress may play a critical role in the vascular disease of end stage renal failure and hemodialysis patients. Studies, analyzing either discrete analytes and antioxidant substances, or the integrated total antioxidant activity of human plasma during hemodialysis, give contradictory results.     

Clinical presentation of the "depression-executive dysfunction syndrome" of late life.

It has been proposed that a "depression-executive dysfunction (DED) syndrome" occurs in late life. This assertion was based on clinical, neuropathological, and neuroimaging findings suggesting that frontostriatal dysfunctions contribute to the development of both depression and executive dysfunction and influence the course of depression. The authors describe the clinical presentation of DED and its relationship to disability, studying 126 elderly subjects with major depression and evaluating depressive symptoms, cognitive functioning, disability, and personality dimensions. Patients with the DED syndrome had reduced fluency, impaired visual naming, paranoia, loss of interest in activities, and psychomotor retardation, but showed a rather mild vegetative syndrome. Depressive symptomatology, and especially psychomotor retardation and loss of interest in activities, contributed to disability in DED patients, whereas paranoia was associated with disability independently of executive dysfunction. These findings may aid clinicians in identifying patients needing vigilant follow-up, because depression with executive dysfunction was found to be associated with disability, poor treatment response, relapse, and recurrence.     

Predictors of early recovery from major depression among persons admitted to community-based clinics: an observational study

BACKGROUND: Twenty years have elapsed since the National Institute of Mental Health Collaborative Depression Study reported on the early course and treatment of major depression within the mental health sector. Using similar methods, an observational study was conducted to assess relationships between initial depression severity, personality dysfunction and other baseline characteristics, subsequent treatment, and 3-month outcomes among persons admitted to public and voluntary sector outpatient clinics, including 1 academic program. METHODS: A 2-stage sampling technique was used to recruit subjects (N = 165) diagnosed by the Structured Clinical Interview for DSM-IV, Patient Version, as having a major depression episode. Sociodemographic and clinical characteristics were assessed at admission. Data on treatment and outcome were obtained at 3 months using structured instruments from the Longitudinal Interview Follow-up Evaluation. Logistic regression was used to assess hypothesized predictors of early recovery. Analyses were carried out in the total sample and after dichotomizing subjects by baseline depression severity. RESULTS: Fifty (30.3%) of the 165 subjects met recovery criteria. Less than half of the subjects (45%) met criteria for adequate pharmacotherapy. Less severe depression, having received adequate antidepressant treatment, female sex, and being married independently predicted early recovery. In the more depressed subgroup, early recovery was associated with female sex. Among less severely depressed subjects, high personality dysfunction scores and being married were significant predictors. CONCLUSIONS: Initial depression severity and receiving adequate pharmacotherapy predict early recovery in individuals with major depression seeking outpatient treatment. A minority of persons receive intensive antidepressant treatment. Less severe personality dysfunction and being married predicts early recovery among persons with less severe depression.     

Strongyloides stercoralis infection as a cause of acute granulomatous appendicitis in an HIV-positive patient in Athens,Greece

A case of acute granulomatous appendicitis due to Strongyloides stercoralis infection in an HIV-positive patient is described. To our knowledge this is the first case presented in the literature.     

Visceral leishmaniasis in paediatrics

Visceral leishmaniasis is a vector-borne systemic infection, which affects half a million people each year in many areas of the world. Typical disease manifests with fever, hepatosplenomegaly, pancytopenia, and progressive deterioration of the host. Although molecular methods appear promising as a non-invasive diagnostic tool, definite diagnosis still relies on the demonstration of the parasite in tissue. Pentavalent antimonial compounds remain the mainstay of treatment worldwide, except in India. During the past decade, short courses of lipid formulations of amphotericin B were assessed and proved effective; however, their cost precludes their wide use in developing countries. Miltefosine, an oral active agent, was recently identified, and might fulfil our expectations for an effective, safe, easily administered and affordable antileishmanial treatment.     

Effects of lipids on thrombotic mechanisms in atherosclerosis

Cholesterol lowering therapy markedly reduces the frequency of subsequent cardiovascular events and is associated with a modest degree of angiographic regression of atherosclerotic lesions. There is a strong association between lipids and fibrinogen, plasminogen activator-1, and activated factor VII levels. Low density lipoprotein may be thrombogenic whereas high density lipoprotein protects against thrombosis. Lipoprotein (a) may affect atherosclerosis and thrombosis mainly by binding to fibrin and attenuating the fibrin-enhanced plasminogen activation. Tissue factor-complex initiates coagulation by activating factor X and factor IX leading in the presence of calcium to the generation of thrombin. Lipid lowering treatment with statins stabilizes atheromatous plaque and has antithrombotic effects. Therefore there are links between lipids and the haemostatic mechanisms which affect atherosclerotic, vasomotor and thrombotic components of ischemic heart disease.