Xylella fastidiosa subsp. pauca and fastidiosa Colonize Arabidopsis Systemically and Induce Anthocyanin Accumulation in Infected Leaves.

The bacterium Xylella fastidiosa is a multihost pathogen that affects perennial crops such as grapevine, sweet orange, and olive tree worldwide. It is inherently difficult to study these pathosystems owing to the long-term growth habit of the host plant. Thus, the availability of model plants becomes essential to accelerate discoveries with economic impact. In this study, we uncovered evidence that the model plant Arabidopsis thaliana can be colonized by two different X. fastidiosa subspecies, pauca and fastidiosa. We observed that these bacteria are able to move away from the inoculation point as high bacterial populations were found in distant tissues. In addition, confocal laser scanning microscopy analysis of bacterial movement inside the petiole revealed the ability of the bacterium to move against the net xylem flow during the time course of colonization forming biofilm. These findings provide evidence for the capacity of X. fastidiosa to colonize Arabidopsis. Furthermore, leaves inoculated with X. fastidiosa showed a significant accumulation of anthocyanin. We propose that the X. fastidiosa subsp. pauca or fastidiosa colonization pattern and anthocyanin accumulation in the Arabidopsis ecotype Col-0 can be used as marker phenotypes to facilitate further studies aimed at improving genetic components involved in X. fastidiosa-host interaction.

Brainstem areas activated by intermittent apnea in awake unrestrained rats.

We investigated the role of the autonomic nervous system to cardiovascular responses to obstructive apnea in awake, unrestrained rats, and measured expression of Fos induced by apnea in the brainstem. We implanted a tracheal balloon contained in a rigid tube to allow the induction of apnea without inducing pain in the trachea. During bouts of 15s of apnea, heart rate fell from 371±8 to 161±11bpm (mean±SEM, n=15, p<0.01) and arterial pressure increased from 115±2 to 131±4mmHg (p<0.01). Bradycardia was due to parasympathetic activity because it was blocked by the muscarinic antagonist, methylatropine. The pressor response was due to vasoconstriction caused by sympathetic activation because it was blocked by the α1 antagonist, prazosin. Apnea induced Fos expression in several brainstem areas involved in cardiorespiratory control such as the nucleus of the solitary tract (NTS), ventrolateral medulla (VLM), and pons. Ligation of the carotid body artery reduced apnea-induced bradycardia, blocked heart rate responses to i.v. injection of cyanide, reduced Fos expression in the caudal NTS, and increased Fos expression in the rostral VLM. In conclusion, apnea activates neurons in regions that process signals from baroreceptors, chemoreceptors, pulmonary receptors, and regions responsible for autonomic and respiratory activity both in the presence and absence of carotid chemoreceptors.

Associação de carboidrases e fitase em dietas valorizadas e seus efeitos sobre desempenho e qualidade dos ovos de poedeiras leves / Association of carbohydrases and phytase in enriched diets ranked and its effects on performance and quality of eggs from light laying hens

Foram utilizadas 350 aves da linhagem comercial Bovans White, com o objetivo de avaliar a associação de carboidrases e fitase em dietas valorizadas sobre o desempenho e qualidade dos ovos de poedeiras leves. O delineamento experimental foi inteiramente ao acaso, com 5 tratamentos e 7 repetições. Os tratamentos foram: T1- Controle positivo sem adição de enzimas e sem valorização dos nutrientes; T2- Controle negativo (CN) 1, valorizando em 1,5% e 6% a EMA (kcal/kg), respectivamente para o milho e o farelo de soja, e em 2% a proteína bruta (PB) e os aminoácidos digestíveis limitantes mais a matriz completa para a enzima fitase; T3- CN 2, valorizando em 1,5% e 6% a EMA (kcal/kg), respectivamente para o milho e o farelo de soja, e em 2% a proteína bruta (PB) e os aminoácidos digestíveis limitantes mais a matriz incompleta para a enzima fitase; T4- suplementado com 100g ton-1 de carboidrase e 30g ton-1 de fitase; T5- suplementado com 100g ton-1 de carboidrase e 30g ton-1 de fitase. Os tratamentos controle positivo, T2, T3, T4 e T5, com ou sem suplementação enzimática, garantiram o desempenho no que diz respeito ao consumo de ração, produção, peso e perdas de ovos e qualidade da casca.

A total of 350 commercial Bovans White laying hens were used to evaluate the association of carbohydrases and phytase in enriched diets and its effects on performance and egg quality of laying hens. The experiment used a randomized design with five treatments and seven replicates. The treatments were: 1. Positive control without added enzymes and without nutrient enrichment, 2. Negative control (NC) 1 with 1.5% and 6% AME (kcal/kg) enrichment for corn and soybean meal respectively, 2% crude protein (CP) enrichment, and digestible limiting digestible amino acids plus the full matrix for the phytase enzyme; 3. NC 2 with 1.5% and 6% AME (kcal/kg) enrichment, respectively, for corn and soybean meal and 2% crude protein (CP) enrichment, and digestible limiting amino acids plus the sparse matrix for the phytase enzyme, 4. NC 1 supplemented with 100 g ton-1 carbohydrase and 30g ton-1 phytase, 5. NC 2 supplemented with 100 g ton-1 carbohydrase and 30g ton-1 phytase. According to the results, the positive control treatments, NC1 and NC2, with or without enzyme supplementation, showed guaranteed performance for feed intake, egg yield, weight, egg loss and shell quality.

Broadly cross-neutralizing antibodies in HIV-1 patients with undetectable viremia.

Several recent studies have identified HIV-infected patients able to produce a broad neutralizing response, and the detailed analyses of their sera have provided valuable information to improve future vaccine design. All these studies have excluded patients on antiretroviral treatment and with undetectable viral loads, who have an improved B cell profile compared to untreated patients. To better understand the induction of neutralizing antibodies in patients on antiretroviral treatment with undetectable viremia, we have screened 508 serum samples from 364 patients (173 treated and 191 untreated) for a broadly neutralizing antibody (bNAb) response using a new strategy based on the use of recombinant viruses. Sera able to neutralize a minipanel of 6 recombinant viruses, including envelopes from 5 different subtypes, were found in both groups. After IgG purification, we were able to confirm the presence of IgG-associated broadly neutralizing activity in 3.7% (7 of 191) of untreated patients with detectable viremia and 1.7% (3 of 174) of aviremic patients receiving antiretroviral treatment. We thus confirm the possibility of induction of a broad IgG-associated neutralizing response in patients on antiretroviral treatment, despite having undetectable viremia. This observation is in stark contrast to the data obtained from long-term nonprogressors, whose little neutralizing activity has been attributed to the low levels of viral replication.

Enteroparasitoses em escolares do Distrito de Martinésia, Uberlândia, MG: um estudo-piloto / Intestinal parasitoses in schoolchildren of Martinésia District, Uberlândia, MG: a pilot study

Este trabalho avalia a ocorrência de parasitas intestinais em estudantes do Distrito de Martinésia, município de Uberlândia (MG). Foram examinadas 103 crianças, no período de setembro a novembro de 1995, segundo o método de Lutz ou Hoffman, Pons & Janer. O coeficiente geral de prevalência foi de 22,3% e os índices de infecção mais elevados foram observados no grupo etário 8 a 9 anos (34,8%), nos moradores da vila (30,0%) e no sexo feminino (26,9%). Helmintoses e protozooses apresentaram taxas de prevalência similares (10,7% e 12,6%, respectivamente). Giardia lamblia foi o único protozoário parasito verificado e apenas um caso de poliparasitismo foi encontrado. Conclui-se que a prevalência de enteroparasitoses no grupo estudado é menor do que o esperado para uma comunidade rural, o que é, provavelmente, uma conseqüência das boas condições sanitárias presentes naquele distrito.

This work evaluates the occurrence of intestinal parasites in the students of the Martinésia District, Uberlândia municipality, Minas Gerais state. A total of 103 children were examined, from September to November 1995, according to Lutz or Hoffman, Pons and Janer method. The overall prevalence rate was 22.3% and the highest indices of infection were observed in 8-9 age group (34.8%), in village dwellers (30.0%) and in females (26.9%). Helminthiasis and protozoosis showed similar prevalence rates (10.7% and 12.6%, respectively). Giardia lamblia was the unique protozoan parasite verified and only one case of polyparasitism was found. We concluded that: the prevalence of enteroparasitosis in the studied group is lower than expectations for a rural community, what is, probably, a consequence of the good sanitary conditions presenting in that district.

[Intestinal parasitoses in schoolchildren of Martinésia District, Uberlândia, MG: a pilot study]. / Enteroparasitoses em escolares do Distrito de Martinésia, Uberlândia, MG: um estudo-piloto.

This work evaluates the occurrence of intestinal parasites in the students of the Martinésia District, Uberlândia municipality, Minas Gerais state. A total of 103 children were examined, from September to November 1995, according to Lutz or Hoffman, Pons and Janer method. The overall prevalence rate was 22.3% and the highest indices of infection were observed in 8-9 age group (34.8%), in village dwellers (30.0%) and in females (26.9%). Helminthiasis and protozoosis showed similar prevalence rates (10.7% and 12.6%, respectively). Giardia lamblia was the unique protozoan parasite verified and only one case of polyparasitism was found. We concluded that: the prevalence of enteroparasitosis in the studied group is lower than expectations for a rural community, what is, probably, a consequence of the good sanitary conditions presenting in that district.