Role of Th1 and Th2 cytokines in immune response to uncomplicated Plasmodium falciparum malaria

The relative balance between Th1 and Th2 cytokines appears crucial, since the role of cytokines has been evaluated in several studies by comparison of clinically heterogeneous groups of patients. The aim of this study is to determine the role of proinflammatory Th1 cytokines, interleukin-12 (IL-12) and gamma interferon (IFN-gamma), and anti-inflammatory Th2 cytokines, IL-4 and IL-10, in a homogeneous group of patients with uncomplicated Plasmodium falciparum malaria. Levels of IL-12, IFN-gamma, Il-4, and IL-10 in serum for 20 adult patients and 15 healthy control subjects were determined by an immunoenzymatic assay. Serum levels of Th1 cytokines, IL-12 (8.6 +/- 2.8 pg/ml; controls, 3.2 +/- 0.7 pg/ml) and IFN-gamma (39.2 +/- 67.6 pg/ml; controls, 8.4 +/- 6.3 pg/ml), were significantly increased at admission; 3 days later, levels of IL-12 in serum remained significantly high (8.8 +/- 2.6 pg/ml), whereas IFN-gamma levels returned to control values. The anti-inflammatory response of Th2 cytokines (IL-10 and IL-4) was distinct. Levels of IL-10 in serum were not significantly increased at day 0 and day 3 (306.6 +/- 200.4 pg/ml and 56.6 +/- 38.4 pg/ml, respectively; controls, 17.4 +/- 9.0 pg/ml). In contrast, levels of IL-4 in serum were not increased on admission (3.4 +/- 1.2 pg/ml; controls, 2.4 +/- 0.8 pg/ml), but at day 3 a moderate and significant increase of IL-4 levels was observed (4.5 +/- 1.7 pg/ml). In conclusion, the increase of Th1 cytokine IL-12 and IFN-gamma levels during the acute phase of uncomplicated P. falciparum malaria may reflect an early and effective immune response regulated by proinflammatory Th1 cytokines, and in particular IFN-gamma may play a role in limiting progression from uncomplicated malaria to severe and life-threatening complications.     

Effects of ovariectomy and resistance training on oxidative stress markers in the rat liver

OBJECTIVE:

The objective of this study was to assess the effects of resistance training on oxidative stress markers in the livers of ovariectomized rats.

METHOD:

Adult Sprague-Dawley rats were divided into the following four groups (n = 8 per group): sham-operated sedentary, ovariectomized sedentary, sham-operated resistance training, and ovariectomized resistance training. During the resistance training period, the animals climbed a 1.1-m vertical ladder with weights attached to their tails; the sessions were conducted 3 times per week, with 4-9 climbs and 8-12 dynamic movements per climb. The oxidative stress was assessed by measuring the levels of reduced glutathione and oxidized glutathione, the enzymatic activity of catalase and superoxide dismutase, lipid peroxidation, vitamin E concentrations, and the gene expression of glutathione peroxidase.

RESULTS:

The results showed significant reductions in the reduced glutathione/oxidized glutathione ratio (4.11±0.65 nmol/g tec), vitamin E concentration (55.36±11.11 nmol/g), and gene expression of glutathione peroxidase (0.49±0.16 arbitrary units) in the livers of ovariectomized rats compared with the livers of unovariectomized animals (5.71±0.71 nmol/g tec, 100.14±10.99 nmol/g, and 1.09±0.54 arbitrary units, respectively). Moreover, resistance training for 10 weeks was not able to reduce the oxidative stress in the livers of ovariectomized rats and induced negative changes in the hepatic anti-oxidative/oxidative balance.

CONCLUSION:

Our findings indicate that the resistance training program used in this study was not able to attenuate the hepatic oxidative damage caused by ovariectomy and increased the hepatic oxidative stress.     

HLA class I and class II haplotypes in admixed families from several regions of Mexico

We studied HLA class I and class II alleles in 191 Mexican families (381 non-related individuals) to directly obtain the HLA-A/B/DRB1/DQB1 haplotypes and their linkage disequilibrium (LD). The most frequent HLA haplotypes observed were: A*02-B*39-DRB1*04-DQB1*0302, A*02-B*35-DRB1*04-DQB1*0302, A*68-B*39-DRB1*04-DQB1*0302, A*02-B*35-DRB1*08-DQB1*04, A*33-B*1402-DRB1*01-DQB1*05, and A*24-B*35-DRB1*04-DQB1*0302. The four most common haplotypes found by our study involve those previously reported in Amerindian populations. LD analysis of HLA-A-B and HLA-B-DRB1 loci showed significant associations between A29(19)-B44(12), A33(19)-B65(14), A1-B8, A26(19)-B44(12), A24(9)-B61(40), B65(14)-DR1, B8-DR17(3), B44(12)-DR7, B7-DR15(2), and B39(16)-DR4. Also, all DRB1-DQB1 associations showed significant LD values. Admixture estimations using a trihybrid model showed that Mexicans from the State of Sinaloa (Northern Mexico) have a greater proportion of European genetic component compared with Mexicans from the Central area of Mexico, who have a greater percentage of Amerindian genes. Our results are important for future comparative genetic studies of different Mexican ethnic groups with special relevance to disease association and transplantation studies.     

Parasites of the fish Cichla piquiti (Cichlidae) in native and invaded Brazilian basins: release not from the enemy, but from its effects

The enemy release hypothesis is frequently used to explain the success of invaders, postulating that introduced species have escaped from their native enemies, including parasites. Here, we tested this hypothesis for the tucunaré (Cichla piquiti), a predatory cichlid, and its endoparasites. First, the parasites and their influence on the condition of the hosts in the native environment, the Tocantins River (TO), were compared to an environment where the fish was introduced, the Paraná River (PR). Then, comparisons of the abundances of Diplostomidae eye flukes and Contracaecum sp. larval nematodes were made between the introduced tucunaré and two predators native to the PR, Hoplias malabaricus and Raphiodon vulpinus. Nine species of endoparasites were recorded in total, five of which occurring in both localities. Total species richness did not differ between localities, and fish condition was negatively affected by the cestodes Sciadocephalus megalodiscus only in the TO. In the PR, abundance of Contracaecum sp. did not differ between natives and invaders; however, eye flukes were more abundant in the native fish H. malabaricus, which may represent an advantage to the invader if they were competing for prey. These results did not support the idea that the escape from parasites favoured the establishment of C. piquiti in the PR. Instead, the escape from the parasites' effects seems a better explanation, and further studies examining effects on host physiology and/or fitness in the native and introduced ranges are needed.     

Correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter during endovascular repair of abdominal aortic aneurysm

PURPOSE: To establish a correlation between intrasac pressure measurements of a pressure sensor and an angiographic catheter placed in the same aneurysm sac before and after its exclusion by an endoprosthesis. METHODS: Patients who underwent endovascular abdominal aortic aneurysm repair and received an EndoSure wireless pressure sensor implant between March 19 and December 11, 2004 were enrolled in the study. Simultaneous readings of systolic, diastolic, mean, and pulse pressure within the aneurysm sac were obtained from the catheter and the sensor, both before and after sac exclusion by the endoprosthesis (Readings 1 and 2, respectively). Intrasac pressure measurements were compared using Pearson's correlation and Student's t test. Statistical significance was set at p<0.05. RESULTS: Twenty-five patients had the pressure sensor implanted, with simultaneous readings (i.e., recorded by both devices) obtained in 19 patients for Reading 1 and in 10 patients for Reading 2. There was a statistically significant correlation for all pressure variables during both readings, with p<0.01 for all except the pulse pressure in Reading 1 (p<0.05). Statistical significance of pressure variations before and after abdominal aortic aneurysm exclusion was coincident between the sensor and catheter for diastolic (p>0.05), mean (p>0.05), and pulse (p<0.01) pressures; the sole disagreement was observed for systolic pressure, which varied, on average, 31.23 mmHg by the catheter (p<0.05) and 22 mmHg (p>0.05) by the sensor. CONCLUSION: The excellent agreement between intrasac pressure readings recorded by the catheter and the sensor justifies use of the latter for detection of post-exclusion abdominal aortic aneurysm pressurization.     

The interleukin 1B-511 polymorphism is associated with the risk of developing restenosis after coronary stenting in Mexican patients

Inflammation is the primary response to vessel wall injury caused by stent placement in coronary arteries. Cytokines of the interleukin-1 family are central regulators in immunoinflammatory mechanisms. The objective of this study was to test for association between IL-1 family gene polymorphisms and risk for restenosis after coronary stent placement. The IL-1B-511, IL-1F10.3, RN.4T>C, RN.6/1C>T, RN.6/2C>G, and IL-1RN VNTR polymorphisms were analyzed by 5' exonuclease TaqMan genotyping assays and polymerase chain reaction in a group of 165 patients who underwent coronary artery stenting. Basal and procedure coronary angiography were analyzed in search of angiographic predictors of restenosis and follow-up angiography was analyzed in search of binary restenosis. Patients with IL-1B-511 TT genotype had a 1.89-fold increased risk of developing restenosis. The analysis considering the lesions treated demonstrated that the lesions of patients with IL-1B-511 TT genotype had a 3.44-fold increased risk of developing restenosis. When the analysis considered the type of stent, the risk of developing restenosis was increased in lesions of patients with TT genotype (odds ratio = 4.50) who underwent coronary bare-metal stent implantation. Multiple logistic analysis identified IL-1B-511 TT genotype as an independent predictor for restenosis. The results suggest that IL-1B-511 polymorphism could be involved in the risk of developing restenosis after coronary stent placement.     

Cognitive and behavioural effects of physical exercise in psychiatric patients

The current review outlines the under-appreciated effects of physical exercise on the course of psychiatric disorders, focussing on recent findings from animal and human research. Several studies have shown that regular physical exercise is significantly beneficial for psychiatric patients both on a biological and a psychological level. Positive effects of controlled exercise include improved metabolic responses, neuro-protection, increased quality of life, and reduced psychopathological symptoms.Studies investigating the effectiveness of various physical training interventions in alleviating severe mental diseases, such as Alzheimer's dementia (AD), schizophrenia (SZ) or major depressive disorder (MDD) indicate that physical exercise can relieve symptoms of depression, psychosis and dementia and more importantly can curtail further progression of these diseases. This review assesses the most effective methods of physical training for specific psychiatric symptoms.Introducing physical exercise in therapeutic regimes would be an innovative approach that could significantly reduce the severity of psychopathological and cognitive symptoms in patients. The positive biological and molecular outcomes associated with physical exercise render it a concrete therapeutic strategy for improving the quality of live and reducing physical illness in psychiatric patients. Therefore, integrating physical activity into a patient's social life may be an effective treatment strategy. Furthermore, exercise might have the potential to be a preventative treatment within the context of multi-modal therapeutic programs.     

Penicillin resistance and serotyping of Streptococcus pneumoniae in Latin America

Streptococcus pneumoniae (Strep. pneumoniae) is the main cause of bacterial pneumonia in children less than 5 years of age, with high mortality rates in developing countries. In 1993, the Regional System for Vaccines Group (SIREVA) of the pan-American Health Organisation (PAHO) began a study involving six Latin American countries to identify serotypes and their representativity in the new conjugated vaccines, and to determine the degree of resistance to penicillin. Serotypes 14 (highest resistance level), 5, 1, 6A/B, 23F, 7F, 9V, 19F, 18C, 19A, 9N, were prevalent in the region, with some differences among countries. Although resistance to penicillin ranged from 2% (Brazil) to 21.1% (Mexico), studies have shown that pneumonia caused by Strep. pneumoniae with diminished sensitivity to penillin can be treated with this antibiotic. Only 58% of the serotypes isolated in the region studied were represented in the seven-valent vaccine. Continual surveillance is essential to determine which formulation of conjugated vaccine will be suitable for use in Latin America.     

Neurocutaneous melanosis and negative fluorodeoxyglucose positron emission tomography

Neurocutaneous melanosis is a rare condition characterized by cutaneous melanocytic naevi and the presence of melanocytes in the leptomeninges. It is commonly associated with malignant melanoma formation in the central nervous system (CNS) with poor prognosis. Herein, we report a 13-year-old boy with neurocutaneous melanosis who presented with seizure with diffuse CNS malignant melanoma, as demonstrated by magnetic resonance imaging (MRI). 18F-fluorodeoxyglucose positron emission tomography (PET) was carried out, but was unable to detect the CNS involvement. So far, this is the first report involving the use of PET in neurocutaneous melanosis and we suggest that MRI is more sensitive than PET with 18F-fluorodeoxyglucose in such conditions.     

pHLA3D: Updating the database of predicted three-dimensional structures of HLA with HLA-DR,HLA-DQ and HLA-DP molecules

To improve the availability of three-dimensional (3D) structures of HLA molecules, we created the pHLA3D database. In its first version, we modeled and published 106 3D structures of HLA class I molecules from the HLA-A, HLA-B, and HLA-C loci. This paper presents an update of this database, providing more 127 3D structures of HLA class II molecules (41 DR, 42 DQ, and 44 DP), predicted via homology modeling with MODELLER and SWISS-MODEL. These new 3D structures of HLA class II molecules are now freely available at pHLA3D (www.phla3d.com.br) for immunologists and other researchers working with HLA molecules.