Dissociating activity in the lateral intraparietal area from value using a visual foraging task

We make decisions about where to look approximately three times per second in normal viewing. It has been suggested that eye movements may be guided by activity in the lateral intraparietal area (LIP), which is thought to represent the relative value of objects in space. However, it is not clear how values for saccade goal selection are prioritized while free-viewing in a cluttered visual environment. To address this question, we compared the neural responses of LIP neurons in two subjects with their saccadic behavior and three estimates of stimulus value. These measures were extracted from the subjects' performance in a visual foraging task, in which we parametrically controlled the number of objects on the screen. We found that the firing rates of LIP neurons did not correlate well with the animals' behavior or any of our estimated measures of value. However, if the LIP activity was further normalized, it became highly correlated with the animals' decisions. These data suggest that LIP activity does not represent value in complex environments, but that the value can easily be extracted with one further step of processing. We propose that activity in LIP represents attentional priority and that the downstream normalization of this activity is an essential process in guiding action.     

Prevalence and pattern of antimicrobial resistance of Shigella species among patients with acute diarrhoea in Karaj,Tehran, Iran

The study was carried out to determine the prevalence and pattern of antimicrobial resistance of Shigella species among patients with acute diarrhoea in Karaj, Tehran, Iran. The study included all acute diarrhoea patients who visited the hospitals and treatment centres of Karaj during November 2001-October 2002. Of 734 stool samples collected from patients with acute diarrhoea and analyzed for Shigella spp., 123 (16.8%) yielded Shigella spp. (7.5% Shigella flexneri, 5.2% S. sonnei, 2.6% S. dysenteriae, and 1.5% S. boydii). Of the Shigella isolates, 90.8% were resistant to one or more antimicrobial agent(s), and 87.8% were multidrug resistant. The most common resistance was to tetracycline (73.5%), trimethoprim-sulphamethoxazole (70.4%), and amoxicillin-clavulanic acid (50.0%). Resistance to cefixime, ciprofloxacin, ceftriaxone, and nalidixic acid was observed in 6.1%, 3.1%, 2.0%, and 1.0% of the isolates respectively. These findings suggest that Shigella spp. may be an important aetiological agent of diarrhoea with a high rate of drug resistance in this region, which requires further study.     

Safety and Efficacy of Setarud (IMOD TM ) Among People Living with HIV/AIDS: A Review

The broad use of highly active anti-retroviral therapy (HAART), especially in developing world, has been associated with several problems such as lactic acidosis, lipodistrophy, pancreatitis, hyperlipidemia, insulin resistance and hepatotoxicity. Extensive use of HAART has also resulted in emergence of resistant HIV variants. Thereby, a pressing need for development of novel and cost-effective agents arises from these limitations. Setarud (IMODTM) is a safe, naturally- derived immunomodulator that was introduced for treatment of HIV patients in Iran. It is prepared as a mixture of herbal extracts including Tanacetum vulgare (tansy), Rosa canina and Urtica dioica (nettle) in addition to selenium, flavonoids and carotenes. Tanacetum vulgare may relieve anti-inflammatory symptoms and Rosa canina defers blood glucose and cholesterol elevation. Extracts from Urtica dioica may prevent maturation of myeloid dendritic cells and reduce T cell responses. A significant rise of CD4 count was observed in HIV patients treated by IMODTM in clinical trial phases, which could be explained by its immunomodulatory effects. Anti-oxidative activity of compounds in IMODTM might play a role in the clinical outcomes of patients treated with this drug. Moreover, IMODTM may show improving activity upon lipid profile and liver metabolism. According to studies on IMODTM, it seems that IMODTM has minor side effects. IMODTM with international publication number WO 2007/087825 A1 is an herbal extract which includes Rosa canina, Urtica dioica, Tanacetum vulgare, and selenium comprising a treatment by pulsed electromagnetic field of high frequency and is useful in treatment of HIV infection and AIDS.     

A correlative study comparing current different methods of calculating left ventricular ejection fraction

BACKGROUND: Left ventricular ejection fraction (EF) is a major determinant of survival in patients with coronary artery disease (CAD). Comparative accuracy of numerous modalities in calculating EF is not well investigated. METHOD: We compared EF as calculated by rest and post-stress Cedars automated quantitative gated SPECT (AQGS), rest and post-stress semi-automatically processed gated SPECT (MQGS), echocardiography and contrast ventriculography (LVG) to those determined by rest and post-stress cavity-to-myocardium ratio (CMR) in 109 patients. Gated SPECT was performed based on a 2-day protocol using Tc-MIBI. RESULTS: Mean EF in LVG, echo, post-stress CMR, rest CMR, post-stress AQGS, rest AQGS, post-stress MQGS and rest MQGS were 41.8%+/-12.1, 44.8%+/-11.8, 38.1%+/-10.7, 35.7%+/-12.1, 44.5%+/-15.1, 46.9%+/-14.7, 40.1%+/-14.3 and 43.5%+/-14.3 respectively. Although significant differences were observed between some of these methods, good and excellent linear correlations were present among values (all Pearson correlations >0.63). Considering LVG as the 'gold standard', we defined two groups: EF <35% (class 1) and >35% (class 2). Discriminant analysis showed that SPECT has the ability to predict patients' classes. In 4/18 of patients with normal SPECT (on both visual and quantitative analyses, SSS <4), EF on QGS showed a significant decrease on post-stress compared with rest. CONCLUSION: There is a good correlation in calculating EF by LVG, QGS and echocardiography, regardless of EF value. Whenever QGS is impossible, CMR is a reliable indirect indicator of EF. Gating of both phases (and when impossible, CMR of both phases) has an additional value in diagnosis of CAD.     

A pure salience response in posterior parietal cortex

When exploring a visual scene, some objects perceptually popout because of a difference of color, shape, or size. This bottom-up information is an important part of many models describing the allocation of visual attention. It has been hypothesized that the lateral intraparietal area (LIP) acts as a "priority map," integrating bottom-up and top-down information to guide the allocation of attention. Despite a large literature describing top-down influences in LIP, the presence of a pure salience response to a salient stimulus defined by its static features alone has not been reported. We compared LIP responses with colored salient stimuli and distractors in a passive fixation task. Many LIP neurons responded preferentially to 1 of the 2 colored stimuli, yet the mean responses to the salient stimuli were significantly higher than to distractors, independent of the features of the stimuli. These enhanced responses were significant within 75 ms, and the mean responses to salient and distractor stimuli were tightly correlated, suggesting a simple gain control. We propose that a pure salience signal rapidly appears in LIP by collating salience signals from earlier visual areas. This contributes to the creation of a priority map, which is used to guide attention and saccades.     

Intravitreal ganciclovir in the management of non-AIDS-related human cytomegalovirus retinitis

Objective:To report and evaluate intravitreal ganciclovir injections in non-AIDS patients with human cytomegalovirus (HCMV) retinitis. Design: Retrospective chart review.Participants: Two SLE patients and one patient post chemotherapy for a non Hodgkin's lymphoma presented with myelosuppression and persistent cytomegalovirus retinitis despite systemic ganciclovir therapy.Methods: Patients were treated with 100 μL of intravitreal ganciclovir (4 mg/dL), initially given weekly. Systemic anti-CMV medication was stopped, and following quiescence, intravitreal injections were tapered and ultimately stopped based on therapeutic response. Patients were followed periodically for signs of recurrence.Results: Intravitreal ganciclovir was well tolerated and led to remission of the retinitis in 2 patients. One patient had persistent smouldering disease and reached quiescence using an intravitreal ganciclovir implant. Fluorescence-activated cell sorting analysis in one patient showed the presence of low CD4 and CD8 while treated with systemic ganciclovir, which improved with intravitreal treatment. In another, the low ratio was maintained against cytomegalovirus-specific antigens.Conclusions: Intravitreal ganciclovir injections should be considered as a treatment option in selected iatrogenically immunocompromised patients with HCMV retinitis. Responses may vary and will require an adjusted approach to treatment.