Overshadowing in conditioned taste aversion or in conditioned emotional response after neonatal ventral hippocampal lesions in rats

The neonatal hippocampus lesion thought to model schizophrenia should show the same modifications in behavioural tests as other models, especially pharmacological models. namely decreased latent inhibition, blocking and overshadowing. The present study is set out to evaluate overshadowing in order to complement our previous studies, which had tested latent inhibition. ""Overshadowing"" refers to the decreased conditioning that occurs when the to-be-conditioned stimulus is combined with another stimulus at the conditioning stage. We used the same two Pavlovian conditioning paradigms as in our previous works, namely conditioned taste aversion (CTA) and conditioned emotional response (CER). A sweet taste overshadowed a salty conditioned stimulus, and a tone overshadowed a flashing light. Totally different stimuli were used to counter possible sensory biases. The protocols were validated with two groups of Sprague Dawley rats. The same two protocols were then applied to a cohort of rats whose ventral hippocampus had been destroyed when they were 7 days old. Only rats with extended ventral hippocampus lesions were included. The overall effect of Pavlovian conditioning was attenuated, significantly so in the conditioned emotional response paradigm, but overshadowing appeared not to be modified in either the conditioned emotional response or the conditioned taste aversion paradigm. (C) 2008 Elsevier B.V. All rights reserved.

Adsorption of phenylalanine on layered double hydroxides: effect of temperature and ionic strength

In this work we report the adsorption of phenylalanine (Phe) on Magnesium Aluminum Layered Double Hydroxides (Mg-Al-CO(3)-LDH) at two different temperatures (298 and 310 K) and under two distinct ionic strength conditions (with and without the addition 0.1 M of NaCl). The adsorption isotherms exhibit the same profile in all conditions, and they only differ in the amount of removed Phe. At lower ionic strength, the isotherms are almost identical at both temperatures, except for the last points, where the increase in temperature causes a decrease in the amount of adsorbed Phe. An increase in ionic strength results in a decrease in Phe adsorption. The electrokinetic potential decreases as the amount of adsorbed Phe increases, and only positive values are observed. This indicates that the surface of the adsorbent is not totally neutralized and suggests that more Phe could be removed by adsorption. The presence of Phe on the solid is confirmed by FTIR spectra, which present the specific bands assigned to Phe. The hydrophobicity of the amino acid probably contributes to its extraction, thus enabling the removal of a great amount of Phe. In conclusion, LDH is potentially applicable in the removal of Phe from wastewater.

Public sociology and social engagement - Considerations on Brazil

The debate on public sociology is spreading in Brazil, a country potentially responsive to Burawoy`s proposals for two reasons: as one of the most unequal countries on the planet, Brazil offers much historical material for reflexive and socially engaged sociology to bring to the non-academic public; and Brazil has a critical and militant sociology that strongly interacts with public sociology. This article provides a `different` reading, through the lens of public sociology of the intellectual and political course of two representatives of this critical and militant sociology: Florestan Fernandes and Francisco de Oliveira.

Identification of Plasmodium relictum causing mortality in penguins (Spheniscus magellanicus) from Sao Paulo Zoo, Brazil

This study reports avian malaria caused by Plasmodium relictum in Magellanic Penguins (Spheniscus magellanicus) from Sao Paulo Zoo. The disease was highly infective among the birds and was clinically characterized by its acute course and high mortality. The penguins of Sao Paulo Zoo were housed for at least 2 years without malaria; however, they had always been maintained in an enclosure protected from mosquito exposure during the night period. When they presented pododermatitis, they were freed at night for a short period. sao Paulo Zoo is located in one of the last forest remnants of the city, an area of original Atlantic forest. In the winter, the space destined for Zoo birds is shared with migratory species. Hence the possibility exists that the disease was transmitted to the penguins by mosquitoes that had previously bitten infected wild birds. Avian malaria parasites are transmitted mainly by mosquitoes of the genera Aedes and Culex, common vectors in the Atlantic forest. In this study, one Culex (Cux.) sp. was found, infected with P. relictum. There are diverse problems in housing distinct species of animals in captivity, principally when occupying the same enclosure, since it facilitates the transmission of diseases with indirect cycles, as is the case of Plasmodium spp., because certain species that cause discrete infections in some bird species can become a serious danger for others, especially penguins, which do not possess natural resistance. Thus, serious implications exist for periodically testing and administrating malaria therapy in captive penguins potentially exposed to mosquitoes during the night period, as well as other captive birds from Sao Paulo Zoo. (C) 2010 Elsevier B.V. All rights reserved.

Depression in women living with HIV: clinical and psychosocial correlates

The number of Brazilian women living with HIV has increased significantly in past years, rendering studies of their particular care demands including psychiatric issues. This study measures the prevalence of major depression, using the Structured Clinical Interview for DSM-IV Axis I Disorders, in a sample of 120 women living with HIV in treatment at a reference centre in So Paulo. Socio-demographic variables, HIV-related clinical and laboratory data, including CD4+ cell counts and HIV plasma viral loads, as well as psychosocial features (intimate relationships, disclosure of HIV serostatus, partner`s serostatus and patient`s emotional and financial support) were investigated as factors potentially associated with depression. The prevalence of major depression at the time of evaluation was 25.8% (95% CI 18.2-33.4%). Clinical status (p = 0.002), lack of emotional support (p = 0.02), use of antidepressants (p = 0.028) and length of time since HIV diagnosis (p = 0.05) were associated with major depression in univariate analysis. In multivariate multiple-regression model, HIV clinical status, lack of emotional support and higher plasma viral loads were associated with depression. Sixty per cent of the women have a major depression diagnosis during lifetime. We conclude that major depression is highly prevalent among women living with HIV, but it is still underdiagnosed and undertreated.

Acute Toxic Leukoencephalopathy: Potential for Reversibility Clinically and on MRI With Diffusion-Weighted and FLAIR Imaging

OBJECTIVE. Toxic leukoencephalopathy may present acutely or subacutely with symmetrically reduced diffusion in the periventricular and supraventricular white matter, hereafter referred to as periventricular white matter. This entity may reverse both on imaging and clinically. However, a gathering together of the heterogeneous causes of this disorder as seen on MRI with diffusion-weighted imaging (DWI) and an analysis of their likelihood to reverse has not yet been performed. Our goals were to gather causes of acute or subacute toxic leukoencephalopathy that can present with reduced diffusion of periventricular white matter in order to promote recognition of this entity, to evaluate whether DWI with apparent diffusion coefficient (ADC) values can predict the extent of chronic FLAIR abnormality ( imaging reversibility), and to evaluate whether DWI can predict the clinical outcome ( clinical reversibility). MATERIALS AND METHODS. Two neuroradiologists retrospectively reviewed the MRI examinations of 39 patients with acute symptoms and reduced diffusion of periventricular white matter. The reviewers then scored the extent of abnormality on DWI and FLAIR. ADC ratios of affected white matter versus the unaffected periventricular white matter were obtained. Each patient`s clinical records were reviewed to determine the cause and clinical outcome. Histology findings were available in three patients. Correlations were calculated between the initial MRI markers and both the clinical course and the follow-up extent on FLAIR using Spearman`s correlation coefficient. RESULTS. Of the initial 39 patients, seven were excluded because of a nontoxic cause (hypoxic-ischemic encephalopathy [HIE] or congenital genetic disorders) or because of technical errors. In the remaining 32 patients, no correlation was noted between any of the initial MRI markers (percentage of ADC reduction, DWI extent, or FLAIR extent) with the clinical outcome. Three patients had histologic correlation. However, moderate correlation was seen between the extent of abnormality on initial FLAIR and the extent on follow-up FLAIR (r = 0.441, p = 0.047). Of the 13 patients who underwent repeat MRI at 21 days or longer, the reduced diffusion resolved in all but one. Significant differences were noted between ADC values in affected white matter versus unaffected periventricular white matter on initial (p < 0.0001) but not on follow-up MRI (p = 0.13), and in affected white matter on initial versus follow-up (p = 0.0014) in those individuals who underwent repeat imaging on the same magnet (n = 9), confirming resolution of the DWI abnormalities. CONCLUSION. Acute toxic leukoencephalopathy with reduced diffusion may be clinically reversible and radiologically reversible on DWI, and may also be reversible, but to a lesser degree, on FLAIR MRI. None of the imaging markers measured in this study appears to correlate with clinical outcome, which underscores the necessity for prompt recognition of this entity. Alerting the clinician to this potentially reversible syndrome can facilitate treatment and removal of the offending agent in the early stages.

Timing of renal replacement therapy and clinical outcomes in critically ill patients with severe acute kidney injury

Purpose: The aim of this study is to evaluate the relationship between timing of renal replacement therapy (RRT) in severe acute kidney injury and clinical outcomes. Methods: This was a prospective multicenter observational study conducted at 54 intensive care units (ICUs) in 23 countries enrolling 1238 patients. Results: Timing of RRT was stratified into ""early"" and ""late"" by median urea and creatinine at the time RRT was started. Timing was also categorized temporally from ICU admission into early (<2 days), delayed (2-5 days), and late (>5 days). Renal replacement therapy timing by serum urea showed no significant difference in crude (63.4% for urea <= 24.2 mmol/L vs 61.4% for urea >24.2 mmol/L; odds ratio [OR], 0.92; 95% confidence interval [CI], 0.73-1.15; P = .48) or covariate-adjusted mortality (OR, 1.25; 95% CI, 0.91-1.70; P = .16). When stratified by creatinine, late RRT was associated with lower crude (53.4% for creatinine >309 mu mol/L vs 71.4% for creatinine <= 309 mu mol/L; OR, 0.46; 95% CI, 0.36-0.58; P < .0001) and covariate-adjusted mortality (OR, 0.51; 95% CI, 0.37-0.69; P < .001).However, for timing relative to ICU admission, late RRT was associated with greater crude (72.8% vs 62.3% vs 59%, P < .001) and covariate-adjusted mortality (OR, 1.95; 95% CI, 1.30-2.92; P = .001). Overall, late RRT was associated with a longer duration of RRT and stay in hospital and greater dialysis dependence. Conclusion: Timing of RRT, a potentially modifiable factor, might exert an important influence on patient survival. However, this largely depended on its definition. Late RRT (days from admission) was associated with a longer duration of RRT, longer hospital stay, and higher dialysis dependence. (C) 2009 Elsevier Inc. All rights reserved.

Use of AST platelet ratio index (APRI Score) as an alternative to liver biopsy for treatment indication in chronic hepatitis C

Chronic hepatitis C (CHC) is one of the most important causes of chronic liver disease in the world, potentially resulting in cirrhosis, hepatocellular carcinoma, and the need for liver transplantation. Liver biopsy is currently performed before therapy indication. Although, it is the golden standard there are many reasons to avoid or delay the procedure. APRI Score is an easy, low cost and practice alternative method which was described as an alternative for assessing structural changes in chronic hepatitis C (CHC). The rationale of this study was to observe the accuracy of APRI Score in comparison to liver biopsy in 400 patients divided into two groups of 200 carriers (Validation and Experimental groups respectively) selected at random or according to liver fibrosis staging (METAVIR). The ROC curves showed a concordance among these two methods of 92% and 88.5% when 1.05 was the cut off (F3 and F4), and 87% and 83%, on 0.75 cut offs (F2-F4). The discordance in advanced fibrosis staging (F3 and F4) was only 16 (8%) and 22 (11%) out of 200 patients in the experimental and validation groups, respectively. In 26 (13%) out of 200 patients in the experimental group and 34 (17%) out of 200 patients in the validation group, there was discordance between APRI Score and liver biopsy in moderate and advanced fibrosis (F2-F4). In conclusion APRI is a serological marker that has satisfactory sensitivity and specificity together with a high predictive value and it can be useful either in the absence of a biopsy or to reduce the frequency with which biopsies need to be carried out to monitor the evolution of chronic hepatitis C and the right moment for treatment indication.

Metabolic syndrome features small, apolipoprotein A-I-poor, triglyceride-rich HDL3 particles with defective anti-apoptotic activity

The metabolic syndrome (MetS) phenotype is typically characterized by visceral obesity, insulin resistance, atherogenic dyslipidemia involving hypertriglyceridemia and subnormal levels of high density lipoprotein-cholesterol (HDL-C), oxidative stress and elevated cardiovascular risk. The potent antioxidative activity of small HDL3 is defective in MetS [Hansel B, et al. J Clin Endocrinol Metab 2004;89:4963-71]. We evaluated the functional capacity of small HDL3 particles from MetS subjects to protect endothelial cells from apoptosis induced by mildly oxidized low-density lipoprotein (oxLDL). MetS subjects presented an insulin-resistant obese phenotype, with hypertriglyceridemia, elevated apolipoprotein B and insulin levels, but subnormal HDL-C concentrations and chronic low grade inflammation (threefold elevation of C-reactive protein). When human microvascular endothelial cells (HMEC-1) were incubated with oxLDL (200 jig apolipoprotein B/ml) in the presence or absence of control HDL subfiractions (25 mu g protein/ml), small, dense HDL3b and 3c significantly inhibited cellular annexin V binding and intracellular generation of reactive oxygen species. The potent anti-apoptotic activity of small HDL3c particles was reduced (-35%; p < 0.05) in MetS subjects (n = 16) relative to normolipidemic controls (n = 7). The attenuated anti-apoptotic activity of HDL3c correlated with abdominal obesity, atherogenic dyslipidemia and systemic oxidative stress (p < 0.05), and was intimately associated with altered physicochemical properties of apolipoprotein A-I (apoA-I-poor HDL3c, involving core cholesteryl ester depletion and triglyceride enrichment. We conclude that in MetS, apoA-I-poor, small, dense HDL3c exert defective protection of endothelial cells from oxLDL-induced apoptosis, potentially reflecting functional anomalies intimately associated with abnormal neutral lipid core content. (c) 2007 Elsevier Ireland Ltd. All rights reserved.

Three-dimensional electrical impedance, tomography: A topology optimization approach

Electrical impedance tomography is a technique to estimate the impedance distribution within a domain, based on measurements on its boundary. In other words, given the mathematical model of the domain, its geometry and boundary conditions, a nonlinear inverse problem of estimating the electric impedance distribution can be solved. Several impedance estimation algorithms have been proposed to solve this problem. In this paper, we present a three-dimensional algorithm, based on the topology optimization method, as an alternative. A sequence of linear programming problems, allowing for constraints, is solved utilizing this method. In each iteration, the finite element method provides the electric potential field within the model of the domain. An electrode model is also proposed (thus, increasing the accuracy of the finite element results). The algorithm is tested using numerically simulated data and also experimental data, and absolute resistivity values are obtained. These results, corresponding to phantoms with two different conductive materials, exhibit relatively well-defined boundaries between them, and show that this is a practical and potentially useful technique to be applied to monitor lung aeration, including the possibility of imaging a pneumothorax.

Management of Neuroendocrine Tumors: A Meeting of Experts from Latin America

A panel of experts from Latin America convened in Brazil, in May of 2007, for consensus recommendations regarding the management of neuroendocrine tumors ( NETs) of the gastrointestinal tract and pancreas. The recently introduced World Health Organization classification of NETs represents a step forward, but the former classification of carcinoids into foregut, midgut and hindgut is still likely to be useful in the near future. Macroscopic description of the tumor should be followed by light microscopic examination and immunohistochemical staining, whereas other techniques might not be widely available in Latin America. Surgery remains the mainstay of treatment for patients with potentially curable tumors, and adequate selection is paramount in order to optimize treatment results. Regarding systemic therapy, patients with well-differentiated tumors or islet-cell carcinomas may be categorized as having indolent disease, while patients with poorly differentiated, anaplastic, and small-cell carcinomas, or with atypical carcinoids, may be approached initially as having aggressive disease. Somatostatin analogues play a cytostatic role in indolent tumors, and chemotherapy may play a role against other, more aggressive NETs. Obviously, there is an urgent need for novel therapies that are effective against NETs. Copyright (C) 2008 S. Karger AG, Basel

Neurological manifestations and ATP7B mutations in Wilson`s disease

Wilson`s disease (WD) is a rare inborn metabolic error characterized by deficient biliary copper excretion secondary to ATP7B gene mutations. Neurological presentations are variable in respect to both pattern and age of onset; commonly a movement disorder presents in the second or third decade. The aim of this study was to ascertain genotype correlations with distinct neurological manifestations in 41 WD patients in a Brazilian center for WD. A total of 23 distinct mutations were detected, and the frameshift 3402de1C had the highest allelic frequency (31.7%). An association between 3402de1C and dysphagia was detected (p = 0.01) but the limited number of patients is insufficient to allow one to draw conclusions. Both clinical studies analyzing larger cohorts and basic research on ATP7B protein function could potentially shed more light on our understanding of WD. (c) 2007 Elsevier Ltd. All rights reserved.

SHOENFELD`S SYNDROME AFTER PANDEMIC INFLUENZA A/H1N1 VACCINATION

Recently, reports have suggested grouping different autoimmune conditions that are triggered by external stimuli as a single syndrome called autoimmune/inflammatory syndrome induced by adjuvants (ASIA). This syndrome is characterized by the appearance of myalgia, myositis, muscle weakness, arthralgia, arthritis, chronic fatigue, sleep disturbances, cognitive impairment and memory loss, and the possible emergence of a demyelinating autoimmune disease caused by systemic exposure after vaccines and adjuvants. In the current study, the authors reported the first Brazilian case of a woman who developed ASIA, which was characterized by arthralgia, changes in inflammatory markers, and chronic fatigue, after the pandemic anti-influenza A/H1N1 vaccine without causing any other rheumatic disease, and it had a positive outcome.

Inflammatory Cytokines during Liver Transplantation: Prospective Randomized Trial Comparing Conventional and Piggyback Techniques

Background/Aims: Cytokines have a significant role in the response to injury following liver transplantation, but the origin and course of such molecules are not completely known. The aim of this study was to evaluate the production and liver metabolism of the inflammatory cytokines interleukin (IL)-1 beta, IL-6, IL-8, interferon (IFN)-Y and tumor necrosis factor (TNF)-alpha in orthotopic liver transplantation (OLT), comparing the conventional and the piggyback methods. Methodology: We performed a study of 30 patients who underwent elective OLT and were randomized for the conventional or piggyback techniques at the beginning of the operation. The amount of cytokines and their hepatic metabolism were calculated based on plasma concentrations and vascular blood flow at 2, 5, 10, 15, 30, 60, 90, and 120 minutes after revascularization. Results: The amount of IL-1 beta in portal blood was higher in patients who underwent surgery using the conventional technique (estimate interest = 63,783.9 +/- 16,586.1 pg/min, versus 11,979.6 +/- 16,585.7 pg/min in the piggyback group, p=0.035). There were no significant differences between the two operative`s methods for IL-6, IL-8, IFN-Y and TNF-alpha production. The hepatic metabolism of cytokines was not different between groups. Although all the curves showed higher amounts of cytokines with the conventional technique, these were not statistically significant. Conclusion: The study shows the similarity between the two techniques concerning the stimuli for the production of inflammatory molecules.

The remodeling of collagen fibers in rats ankles submitted to immobilization and muscle stretch protocol

To evaluate the remodeling of collagen fibers in the articular cartilage of rat ankles, with and without immobilization, after application of muscle stretching protocol. Twenty three Wistar rats were divided into four groups: immobilized (I), n = 6; immobilized and stretched (IS), n = 6; stretched (S), n = 6 and control (C), n = 5. The animals in groups I and IS were submitted to immobilization. After the period of immobilization, the animals in groups IS and S were submitted to a muscle stretching protocol. At the end of the experiment, the animals were euthanized and the joints removed, processed and stained with Picrosirius red. The analysis was carried out using a polarized light microscope. The density of collagen fibers were quantified according to the intensity of birefringence displayed. By way of statistical analyses, the right and left hind limbs of the different groups were compared based on the total density of collagen fibers, the density of thick collagen fibers and the density of thin collagen fibers. Immobilization promoted a reduction in density of the thin fibers and of total collagen. The muscle stretching protocol after immobilization promoted a reduction in density of the total collagen and of the thick fibers, but the density of the thin fibers showed the same values as control. The collagen fibers were remodeled by the different stimuli. Immobilization was harmful to the collagen fibers and the muscle stretching protocol only recovered the thin collagen fibers.