Drawing improves memory in patients with hippocampal damage.

The hippocampus plays a critical role in the formation of declarative memories, and hippocampal damage leads to significant impairments in new memory formation. Drawing can serve as a form of multi-modal encoding that improves declarative memory performance relative to other multimodal encoding strategies such as writing. We examined whether, and to what extent, patients with hippocampal damage could benefit from the mnemonic strategy of drawing. Three patients with focal hippocampal damage, and one patient with both hippocampal and cortical lesions, in addition to 22 age-, sex-, and education-matched controls, were shown a list of words one at a time during encoding and instructed to either draw a picture or repeatedly write each word for 40 s. Following a brief filled delay, free recall and recognition memory for words from both encoding trial types were assessed. Controls showed enhanced recall and recognition memory for words drawn versus those that were written, an effect that was even more pronounced in patients with focal hippocampal damage. By contrast, the patient with both hippocampal and cortical lesions showed no drawing-mediated boost in either recall or recognition memory. These findings demonstrate that drawing is an effective encoding strategy, likely accruing from the engagement of extra-hippocampal processes including the integration of cortical-based motor, visual, and semantic processing, enabling more elaborative encoding.

Accuracy of silicone impressions and stone models using two laboratory scanners: a 3D evaluation.

PURPOSE: To evaluate the in vitro accuracy of impressions obtained with two silicone and corresponding stone models using two laboratory scanners. MATERIAL AND METHODS: A master model with synthetic resin teeth with two single-unit crown preparations was created and scanned using a 12-MP scanner. Five conventional impressions of the physical model were prepared with different silicone impression systems (Zhermack and Coltene) using the double-mix technique and poured with gypsum. The impressions and stone models obtained were scanned by two extraoral scanning systems (Identica T500 Medit and S600 ARTI Zirkonzahn). All best-fit superimpositions of the teeth areas were conducted between the master model and the scans of the impressions and models obtained with the two scanners. A P < .05 significance level was considered. RESULTS: The Identica T500 Medit scanner showed an accuracy of 102.34 (89.67, 115.01) µm for Coltene silicone and 79.51 (67.82, 91.21) µm for Zhermack silicone, while the S600 ARTI Zirkonzhan scanner presented 110.79 (98.24, 123.33) µm and 91.91 (81.29, 102.54) µm, respectively, with significant differences between scanners for Zhermack silicone (P = .008) and for the corresponding stone models (P = .002). Zhermack silicone presented overall discrepancies lower than Coltene silicone, with statistically significant differences in both scanners analyzed (P < .001; P = .017). However, the discrepancies found were within clinically acceptable values. With the Zirkonzahn scanner, discrepancies found in the Zhermack impressions were lower than in the corresponding stone models (P < .001). CONCLUSION: The direct digitalization of silicone impressions by laboratory scanners presented comparable results to conventional techniques with stone models.

SPECT/CT lymphoscintigraphy of heterotopic cardiac grafts reveals novel sites of lymphatic drainage and T cell priming.

The normal function of lymphatic vessels is to facilitate the trafficking of antigen presenting cells to draining lymph nodes where they evoke an immune response. Donor lymphatic vessels are not connected to that of recipients' during organ transplantation. The pathophysiology of this disruption has received little attention. Murine heterotopic cardiac transplantation has been used extensively in transplantation research. Following vascularized organ transplantation, the main site of allosensitization is thought to be in the spleen of the recipient as a result of migration of donor passenger leukocytes via blood. Here, using Single Photon Emission Computed Tomography/Computerized Tomography (SPECT/CT) lymphoscintigraphy, we studied the pattern of lymphatic flow from mouse heterotopic abdominal cardiac grafts and identified mediastinal lymph nodes as the draining nodes for the donor graft. Staining with HY tetramer after transplantation of HY mismatched heart grafts and ELISPOT following allogeneic grafts to detect donor specific T cells revealed them as important sites for allosensitization. Our data indicates that mediastinal lymph nodes play a crucial role in the alloimmune response in this model, and should be used for ex vivo and adoptive transfer studies after transplantation in addition to the spleen.

A synthetic co-crystal prepared by cooperative single-crystal-to-single-crystal solid-state Diels-Alder reaction.

A single-crystal-to-single-crystal solid-state reaction involving the 2 : 1 charge-transfer complex of 9-bromoanthracene and bis(N-cyclobutylimino)-1,4-dithiin leads to a synthetic co-crystal composed of the Diels-Alder cycloadduct and unreacted 9-bromoanthracene molecules. Analysis of close contacts in the product crystal and DFT energy calculations indicate an ordered arrangement of product and unreacted molecules due to cooperative effects during the reaction.

Middle-Aged Diabetic Females and Males Present Distinct Susceptibility to Alzheimer Disease-like Pathology.

Type 2 diabetes (T2D) is a highly concerning public health problem of the twenty-first century. Currently, it is estimated that T2D affects 422 million people worldwide with a rapidly increasing prevalence. During the past two decades, T2D has been widely shown to have a major impact in the brain. This, together with the cognitive decline and increased risk for dementia upon T2D, may arise from the complex interaction between normal brain aging and central insulin signaling dysfunction. Among the several features shared between T2D and some neurodegenerative disorders (e.g., Alzheimer disease (AD)), the impairment of insulin signaling may be a key link. However, these may also involve changes in sex hormones' function and metabolism, ultimately contributing to the different susceptibilities between females and males to some pathologies. For example, female sex has been pointed as a risk factor for AD, particularly after menopause. However, less is known on the underlying molecular mechanisms or even if these changes start during middle-age (perimenopause). From the above, we hypothesized that sex differentially affects hormone-mediated intracellular signaling pathways in T2D brain, ultimately modulating the risk for neurodegenerative conditions. We aimed to evaluate sex-associated alterations in estrogen/insulin-like growth factor-1 (IGF-1)/insulin-related signaling, oxidative stress markers, and AD-like hallmarks in middle-aged control and T2D rat brain cortices. We used brain cortices homogenates obtained from middle-aged (8-month-old) control Wistar and non-obese, spontaneously T2D Goto-Kakizaki (GK) male and female rats. Peripheral characterization of the animal models was done by standard biochemical analyses of blood, plasma, or serum. Steroid sex hormones, oxidative stress markers, and AD-like hallmarks were given by specific ELISA kits and colorimetric techniques, whereas the levels of intracellular signaling proteins were determined by Western blotting. Albeit the high levels of plasma estradiol and progesterone observed in middle-aged control females suggested that they were still under their reproductive phase, some gonadal dysfunction might be already occurring in T2D ones, hence, anticipating their menopause. Moreover, the higher blood and lower brain cholesterol levels in female rats suggested that its dysfunctional uptake into the brain cortex may also hamper peripheral estrogen uptake and/or its local brain steroidogenic metabolism. Despite the massive drop in IGF-1 levels in females' brains, particularly upon T2D, they might have developed some compensatory mechanisms towards the maintenance of estrogen, IGF-1, and insulin receptors function and of the subsequent Akt- and ERK1/2-mediated signaling. These may ultimately delay the deleterious AD-like brain changes (including oxidative damage to lipids and DNA, amyloidogenic processing of amyloid precursor protein and increased tau protein phosphorylation) associated with T2D and/or age (reproductive senescence) in female rats. By demonstrating that differential sex steroid hormone profiles/action may play a pivotal role in brain over T2D progression, the present study reinforces the need to establish sex-specific preventive and/or therapeutic approaches and an appropriate time window for the efficient treatment against T2D and AD.

Comparing language lateralization determined by dichotic listening and fMRI activation in frontal and temporal lobes in children with epilepsy.

We investigated the relationship between ear advantage scores on the Fused Dichotic Words Test (FDWT), and laterality of activation in fMRI using a verb generation paradigm in fourteen children with epilepsy. The magnitude of the laterality index (LI), based on spatial extent and magnitude of activation in classical language areas (BA 44/45, 21/22, 39) differed significantly for patients classified with unilateral left, compared to bilateral, language representation based on FDWT scores. Concordance with fMRI was higher for those classified with unilateral left, than bilateral language representation on the FDWT. Of note, asymmetry in temporal lobe, rather than frontal lobe, activation was more strongly related to the LI from the dichotic listening test. This study shows that the FDWT can provide a quick and valid estimate of lateralization in pre-surgical candidates, which can be readily adopted for other clinical or research purposes when an estimate of language dominance is desired.

Effects of apolipoprotein E genotype on blood lipid composition and membrane platelet fluidity in Alzheimer's disease.

The blood lipid composition (plasma, platelets and leukocytes), platelet membrane fluidity, apolipoproteins A and B in the plasma of AD patients and control subjects with distinct Apo E genotypes were investigated. No significant differences were found between the Apo E genotype and the cholesterol, phospholipids, triglycerides and Apo B levels in the plasma; cholesterol and phospholipids levels in platelet and leukocyte membranes; and platelet membrane fluidity of AD and control groups. However, the phospholipid levels in the leukocyte membranes of the control subgroup with the genotypes epsilon3/epsilon3 and epsilon3/epsilon4 and the AD subgroups with the genotypes epsilon2/epsilon3 and epsilon3/epsilon3, epsilon3/epsilon4 and epsilon4/epsilon4 were significantly lower than those observed in the control subgroup with the genotype epsilon2/epsilon3. Moreover, the cholesterol and phospholipid levels in the platelet membranes of the AD subgroup with the epsilon2 allele were significantly higher than those in the AD subgroup without the epsilon2 allele and the control subgroups with and without the epsilon2 allele. A strong correlation was found between cholesterol and phospholipids levels in the platelet membranes of the AD and control subgroups without the epsilon2 allele, but the residual cholesterol level in the platelet membranes of the AD subgroup was twice that observed in the control subgroup. Furthermore, the Apo A levels in the plasma of the AD subgroup with the epsilon3 allele were significantly lower than those observed in the AD subgroup without the epsilon3 allele and the control subgroup with the epsilon3 allele. The results are discussed in terms of involvement of lipid metabolism in the etiopathogenesis of AD.

Comparing the Fused Dichotic Words Test and the Intracarotid Amobarbital Procedure in children with epilepsy.

The validity of the Fused Dichotic Words Test (FDWT) in predicting the nature of speech representation, as determined by the Intracarotid Amobarbital Procedure (IAP), was examined in a sample of 28 children with epilepsy. Various methods of analysis (difference score, lambda, and lambda(*)), for the FDWT data were calculated and compared. Results showed the validity of the FDWT did not change depending on the method of analysis. The difference scores showed that 18 of the 19 patients with left hemisphere speech obtained right-ear advantages, while the patient with right hemisphere speech showed a left-ear advantage. As a group, patients with left-hemisphere speech obtained a statistically significant right-ear advantage for the lambda and lambda(*) indices, while the patient with right-hemisphere speech showed a left-ear advantage that was also significant for both lambda measures. Patients with bilateral speech, as a group, displayed a non-significant ear advantage. Some of the scores from the left-hemisphere group overlapped with those from patients with bilateral speech representation. Controlling for stimulus dominance effects using the lambda(*) measure did not improve classification accuracy for nature of speech representation based on FDWT scores. Finally, comparison of our data using the laterality index from a similar study, showed scores smaller in magnitude than that found in adults with epilepsy.

Divided attention and memory: evidence of substantial interference effects at retrieval and encoding.

In 5 divided attention (DA) experiments, students (24 in each experiment) performed visual distracting tasks (e.g., recognition of words, word and digit monitoring) while either simultaneously encoding an auditory word list or engaging in oral free recall of the target word list. DA during retrieval, using either of the word-based distracting tasks, produced relatively larger interference effects than the digit-monitoring task. DA during encoding produced uniformly large interference effects, regardless of the type of distracting task. Results suggest that when attention is divided at retrieval, interference is created only when the memory and concurrent task compete for access to word-specific representational systems; no such specificity is necessary to create interference at encoding. During encoding, memory and concurrent tasks compete primarily for general resources, whereas during retrieval, they compete primarily for representational systems.

Post-transplant lymphoproliferative disorders (PTLD) after renal transplantation: management and evolution of seven cases among 1002 renal transplants in São Paulo, Brazil.

We reported seven cases (0.7%) of PTLD among 1002 renal transplants performed at Renal Transplant Service from Hospital São Paulo-Universidade Federal de São Paulo/Escola Paulista de Medicina, São Paulo, Brazil, between 1976 and 1997. There were three male and four female patients with median age of 37 year-old. According to Ann Arbor staging system there were four localized extra-nodal intermediate-grade NHL, one disseminated low-grade NHL and two polyclonal lymphoid hyperplasia. Four patients received cadaveric, two received related and one received unrelated renal transplant. PTLD occurred after a median latency period of 36 months (ranging from 5 to 84 months). In situ hybridization for EBER1 was performed in five patients and molecular evidence of EBV was found in 3 cases (two DLCL and one lymphoplasmocytoid lymphoma). All patients were treated with immunosuppression withdrawal, four patients received anthracyclin-based chemotherapy for control of localized or systemic clonal disease and three were treated with resection of primary PTLD. Four of seven patients (57%) are in complete remission 11, 20, 25 and 79 months after PTLD onset. One patient lost follow-up and two patients died due to lymphoma relapse, respectively 4 and 10 months after completion of treatment. In conclusion, our experience with this small group of patients showed that: 1) immunosuppression withdrawal is not necessarily associated with loss of renal transplant and can be used as the only treatment for polyclonal PTLD; 2) chemotherapy can simultaneously lead to clonal PTLD remission and periodic immunosuppression, avoiding graft rejection after immunosuppression withdrawal.

Brachytherapy using gold-198 foils in treatment of mouth tumors: case report.

The authors presents a clinical case treated with brachytherapy performed with special mold of gold-198 disc, with the purpose of evaluating the distribution of radiation dose, the viability of manufacturing the radioactivity prosthesis and its operational cost. In despite of being only one case, we can conclude that the prosthesis with gold-198 foils can be manufactured in acrylic with thickness thinner than those ones with cylinder of cesium-137, resulting lower operational costs, besides permitting better distribution of radiation dose on the lesion.

Influence of apolipoprotein E genotype on blood redox status of Alzheimer's disease patients.

The blood redox status of probable Alzheimer's Disease (AD) patients and control subjects with distinct Apo E genotypes was investigated. It was assessed by measuring the levels of hydroperoxides (MDA) in plasma and erythrocytes, the levels of the antioxidant defense system (enzymatic and non-enzymatic) in plasma, erythrocytes, platelets and leukocytes, the activities of catechol-O-methyltransferase (COMT) in erythrocytes and monoamine oxidase-B (MAO-B) in platelets and also the activity of the mitochondrial respiratory chain in leukocytes. No significant differences were found between the Apo E genotype and MDA, uric acid, vitamin E and reduced-glutathione (GSH) levels in plasma; MDA, vitamin E, GSH, superoxide-dismutase (SOD), glutathione-peroxidase (GSH-Px) and COMT levels in erythrocytes; vitamin E levels in the platelets of AD patients and control subjects. However, the uric acid levels in plasma and the COMT levels in erythrocytes of AD patients and control subjects with the epsilon4 allele were significantly lower than those observed in control subjects without the epsilon4 allele. Moreover, the duraquinol oxidation level in leukocytes of AD patients with the epsilon4 allele was significantly higher than that in AD patients without the epsilon4 allele and control subjects with and without the epsilon4 allele. The meaning of these results is discussed in terms of involvement of oxidative stress in the etiopathogenesis of AD.

Apolipoprotein E genotype has no effect on the free intracellular Ca2+ concentration of platelets from Alzheimer's disease patients.

The free intracellular Ca2+ concentration [Ca2+]i of platelets was investigated in Alzheimer's disease (AD) patients and age-matched control subjects with distinct Apo E genotypes. No significant differences were found between the Apo E genotype and the [Ca2+]i levels of platelets (basal and alpha-thrombin stimulated) from AD patients and age-matched control subjects, suggesting that [Ca2+]i homeostasis of platelets from AD patients is independent of the Apo E genotype. The results are discussed in terms of involvement of Apo E and [Ca2+]i changes in the etiopathogenesis of AD.

Chromate-induced human erythrocytes haemoglobin oxidation and peroxidation: influence of vitamin E, vitamin C, salicylate, deferoxamine, and N-ethylmaleimide.

In order to attenuate or to prevent chromate-induced human erythrocytes injury, the influence of vitamin E, vitamin C, salicylate, deferoxamine, and N-ethylmaleimide on chromate-induced human erythrocytes haemoglobin oxidation and peroxidation were investigated. It was observed that pretreatment of human erythrocytes with vitamin E (20 microM), vitamin C (1 mM), salicylate (3 mM), and deferoxamine (4 mM) significantly increased (P=0.0001) chromate-induced human erythrocytes haemoglobin oxidation in a time dependent manner, while it was significantly decreased (P=0.0001) by pretreatment with N-ethylmaleimide (1 mM). In contrast, pretreatment of human erythrocytes with deferoxamine (4 mM) immediately inhibited (P=0.0001) chromate-induced human erythrocytes peroxidation, while it was significantly increased (P=0.0001) by pretreatment with N-ethylmaleimide (1 mM) during the first 4 h of cells exposition to chromate. For time periods superior to 6 h pretreatment with N-ethylmaleimide (1 mM) significantly decreased (P=0.0001) chromate-induced human erythrocytes peroxidation. It was concluded that care must be taken as these drugs are used to prevent against toxicity induced by chromium(VI) compounds.

[Results of activities encouraging community participation in dengue control in an outlying neighborhood of São José do Rio Preto, São Paulo, and the relationship between the population's knowledge and habits]. / Avaliação dos resultados de atividades de incentivo à participação da comunidade no controle da dengue em um bairro periférico do Município de São José do Rio Preto, São Paulo, e da relação entre conhecimentos e práticas desta população.

This study evaluates the results of an educational campaign developed in an outlying neighborhood of São José do Rio Preto, São Paulo, and the relationship between the population's knowledge and habits. Prior to and after the educational activities, samples were taken to measure level of knowledge concerning dengue and its vectors, breeding sites, and control measures. Potential breeding sites were also counted. Knowledge of the disease and its vectors and breeding sites increased, but the same was not true for control measures focusing on water recipients serving as potential breeding sites. There was no change in the number of breeding sites between the first and second stages of the research. Thus, despite increased knowledge, the local population's habits did not changes. These findings are worrisome, since the main goal of the educational campaign, i.e., the change of habits concerning breeding sites for dengue vectors, has not been achieved.

[Transesophageal echocardiography study with dynamic spontaneous contrast of the left atrial appendage, its relationship with the anatomy and thrombus formation]. / Estudo ecocardiográfico transesofágico do contraste espontâneo dinâmico no apêndice auricular esquerdo, sua relação com a anatomia e formação de trombos.

OBJECTIVE: Transesophageal two-dimensional echocardiographic study of anatomical characteristics of the left atrial appendage and its relation to spontaneous dynamic echocardiographic contrast. DESIGN: Outpatients undergoing a prospective two-dimensional transesophageal echocardiographic study. SETTING: Consecutive outpatients studied at the Echocardiographic Laboratory of Gregorio Marañon General Hospital, Madrid. MATERIAL AND METHODS: In each patient at the level of the left atrial appendage we calculated the following transesophageal echocardiographic parameters: end-systolic and end-diastolic maximal longitudinal and transversal diameters, total systolic and diastolic areas, percentage of systolic fractional shortening, presence of left atrial appendage thrombus and spontaneous dynamic echo-contrast. MAIN RESULTS: Left atrial appendage spontaneous dynamic contrast was observed in 48% of the total population. In the group of patients with left atrial spontaneous echo-contrast we observed larger longitudinal systolic (44 +/- 14 mm vs 28 +/- 13 mm, p = 0.01) and diastolic (52 +/- 16 mm vs 38 +/- 12 mm, p = 0.005) diameters, larger transversal systolic (25 +/- 10 mm vs 19 +/- 6 mm, p = 0.03) and diastolic (28 +/- 8 mm vs 25 +/- 9 mm, p = NS) diameters and also larger systolic (601 +/- 204 mm2 vs 337 +/- 110 mm2, p < 0.0001) and diastolic (715 +/- 230 mm2 vs 507 +/- 184 mm2, p = 0.001) areas, compared to the group without this dynamic echocardiographic phenomena. Left atrial appendage percentage of fractional shortening was considerably reduced in patients with spontaneous dynamic echo-contrast (15 +/- 14% vs 39 +/- 18%, p = 0.001) and related to local thrombus formation (13% vs 1%, p < 0.001). CONCLUSIONS: Left atrial spontaneous dynamic echo-contrast is more common in patients with enlarged left atrial appendage systo-diastolic diameters and areas. In this group of patients the presence of left atrial spontaneous echo-contrast is related to a significant reduction in left atrial appendage contractile function and thrombus formation. Parameter analysis of left atrial appendage anatomy by two-dimensional transesophageal echocardiography may have clinical relevance in the assessment of patients with high risk for left atria thromboembolic phenomena.

The functions of TRPA1 and TRPV1: moving away from sensory nerves.

The transient receptor potential vanilloid 1 and ankyrin 1 (TRPV1 and TRPA1, respectively) channels are members of the TRP superfamily of structurally related, non-selective cation channels. It is rapidly becoming clear that the functions of TRPV1 and TRPA1 interlink with each other to a considerable extent. This is especially clear in relation to pain and neurogenic inflammation where TRPV1 is coexpressed on the vast majority of TRPA1-expressing sensory nerves and both integrate a variety of noxious stimuli. The more recent discovery that both TRPV1 and TRPA1 are expressed on a multitude of non-neuronal sites has led to a plethora of research into possible functions of these receptors. Non-neuronal cells on which TRPV1 and TRPA1 are expressed vary from vascular smooth muscle to keratinocytes and endothelium. This review will discuss the expression, functionality and roles of these non-neuronal TRP channels away from sensory nerves to demonstrate the diverse nature of TRPV1 and TRPA1 in addition to a direct role in pain and neurogenic inflammation.

Implementation of immobilization accessories for positioning of small animals for radiation therapy / Implementação de acessórios de imobilização para o posicionamento de pequenos animais para a radioterapia

Radiation therapy is a modality that is presenting great advances in veterinary medicine worldwide. In Brazil, this therapeutic option is underachieved. The success of this method depends on several factors, including the use of appropriate accessories for protection and immobilization of patients. For the immobilization of small animals during treatment, in addition to sedation and anesthesia, immobilizing accessories, similar to those used in human radiotherapy, are used. This study aimed to present proposals for immobilizing accessories adapted to the positioning of small animals in order to be used in radiotherapy planning. In order to achieve results, accessories were made and tested in a living animal simulating a radiotherapy planning, which proved to be favorable to use in positioning small animals undergoing radiotherapy and for implementation processes.(AU)

A radioterapia é uma modalidade que tem apresentando grandes avanços dentro da medicina veterinária pelo mundo. No Brasil, essa opção terapêutica é pouco realizada. O sucesso dessa modalidade depende de vários fatores, entre eles, o uso de acessórios adequados para a proteção e imobilização dos pacientes. Para a imobilização dos pequenos animais durante o tratamento, além da sedação e da anestesia, são utilizados acessórios imobilizadores semelhantes aos usados na radioterapia humana. Devido a isso, este trabalho teve como objetivo de apresentar propostas de acessórios de imobilização adaptados ao posicionamento de pequenos animais para o uso nos planejamentos radioterápicos. Para a sua realização, foram confeccionados acessórios e testados em um animal vivo simulando um planejamento radioterápico, os quais mostraram ser favoráveis ao uso nos posicionamento de pequenos animais submetidos à radioterapia e para sua implementação.(AU)

Duddingtonia flagrans no controle de nematoides gastrintestinais de equinos em fases de vida livre / Control of free living gastrointestinal nematodes of horses using Duddingtonia flagrans

O objetivo deste estudo foi avaliar a atividade predatória do fungo Duddingtonia flagrans contra larvas infectantes (L3) de nematoides gastrintestinais na pastagem e no bolo fecal de equinos, em um período de 21 dias. O delineamento experimental foi inteiramente ao acaso, com três grupos tratados (G1, G2 e G3) e um controle (C), com oito animais/grupo. Os tratados receberam 1,5x105; 3x105 e 6x105 clamidósporos de D. flagrans/kg-1peso vivo animal, G1, G2 e G3, respectivamente, durante 21 dias, com administração a cada três dias. Foram delimitadas 36 áreas de 1m2 cada, equivalendo a repetições em triplicata para cada grupo. As fezes foram coletadas dos animais nos dias 0 (D0), 15 (D15) e 30 (D30 = sete dias após a última administração dos tratamentos) e depositadas nessas áreas de pastagem. O número de larvas presentes nos bolos fecais e na pastagem foi avaliado após 14 e 21 dias de cada etapa de deposição. A avaliação da atividade predatória de D. flagrans na pastagem e nos bolos fecais demonstrou que a redução do número de L3 nos bolos fecais foi acompanhada pelo aumento da variável na pastagem. Não se constatou diferença significativa entre os grupos avaliados em decorrência da temperatura média registrada durante o período. As avaliações realizadas em um curto período podem ser insuficientes para a avaliação do efeito do fungo.(AU)

The aim of this study was to evaluate the predatory activity of the fungus Duddingtonia flagrans against infective larvae (L3 ) of gastrointestinal nematodes of horses in the pasture and dung patch during a period of 21 days. The experimental design was completely randomized, with three groups treated (G1, G2 and G3) and a control (C), with eight animals/group. The treated animals received G1: 1.5x105; G2: 3x105 and G3: 6x105 chlamydospores of D. flagrans/kg body weight during 21 days. The experiment ran in the environment using 36 areas of 1 m2 delimited on pasture, where stool samples were distributed for each group, in triplicates. Feces were collected from the animals at days 0 (D0), 15 (D15) and 30 (D30) and deposited on the pasture areas. After 14 and 21 days of each deposition step , the number of L 3 present in dung and pasture was evaluated. The number of L3 in the dung was accompanied by increase of the same variable in the pasture. The evaluation recorded in a short period may be insufficient to evaluate fungus development.(AU)

Potency ranking of valproic acid analogues as to inhibition of cardiac differentiation of embryonic stem cells in comparison to their in vivo embryotoxicity.

The embryonic stem cell test (EST) is one of the more promising and extensively studied tests in the field of developmental toxicology. We evaluated the effect of a series of structurally related valproic acid analogues on cardiomyocyte differentiation in the EST. The goal of the present study was to determine the applicability of the EST by potency ranking within this chemical class. Cardiomyocyte differentiation was evaluated by morphological scoring as well as by gene expression analysis of cardiac markers using RT-PCR. All VPA analogues tested inhibited cardiomyocyte differentiation, with the exception of (±)-2-ethyl-4-methyl pentanoic acid, which correlates to their known in vivo developmental toxicity. Effects were also evident on gene expression of cardiomyocyte differentiation-regulated genes, such as MHC and Nkx2.5. Overall, the present results indicate that the assay can be a valuable screening tool in potency ranking of structurally related compounds.