Resposta da cultura do feijoeiro à adubação nitrogenada e à inoculação com rizóbio.

bitstream/item/67364/1/34249.pdfOrganizado por: Fábio Martins Mercante e Oscar Fontão de Lima Filho. RELARE

Isolamento e seleção de rizóbios de solos de Mato Grosso Do Sul para inoculação em feijoeiro comum

bitstream/item/66207/1/32003.pdfFERTBI

P2X receptors: epithelial ion channels and regulators of salt and water transport.

When the results from electrophysiological studies of renal epithelial cells are combined with data from in vivo tubule microperfusion experiments and immunohistochemical surveys of the nephron, the accumulated evidence suggests that ATP-gated ion channels, P2X receptors, play a specialized role in the regulation of ion and water movement across the renal tubule and are integral to electrolyte and fluid homeostasis. In this short review, we discuss the concept of P2X receptors as regulators of salt and water salvage pathways, as well as acknowledging their accepted role as ATP-gated ion channels

Genetic Ablation of Pannexin1 Protects Retinal Neurons from Ischemic Injury

Pannexin1 (Panx1) forms large nonselective membrane channel that is implicated in paracrine and inflammatory signaling. In vitro experiments suggested that Panx1 could play a key role in ischemic death of hippocampal neurons. Since retinal ganglion cells (RGCs) express high levels of Panx1 and are susceptible to ischemic induced injury, we hypothesized that Panx1 contributes to rapid and selective loss of these neurons in ischemia. To test this hypothesis, we induced experimental retinal ischemia followed by reperfusion in live animals with the Panx1 channel genetically ablated either in the entire mouse (Panx1 KO), or only in neurons using the conditional knockout (Panx1 CKO) technology. Here we report that two distinct neurotoxic processes are induced in RGCs by ischemia in the wild type mice but are inactivated in Panx1KO and Panx1 CKO animals. First, the post-ischemic permeation of RGC plasma membranes is suppressed, as assessed by dye transfer and calcium imaging assays ex vivo and in vitro. Second, the inflammasome-mediated activation of caspase-1 and the production of interleukin-1β in the Panx1 KO retinas are inhibited. Our findings indicate that post-ischemic neurotoxicity in the retina is mediated by previously uncharacterized pathways, which involve neuronal Panx1 and are intrinsic to RGCs. Thus, our work presents the in vivo evidence for neurotoxicity elicited by neuronal Panx1, and identifies this channel as a new therapeutic target in ischemic pathologies

Orbital/ocular inflammatory involvement in VEXAS syndrome: Data from the international AIDA network VEXAS registry

VEXAS syndrome is a recently described monogenic autoinflammatory disease capable of manifesting itself with a wide array of organs and tissues involvement. Orbital/ocular inflammatory manifestations are frequently described in VEXAS patients. The objective of this study is to further describe orbital/ocular conditions in VEXAS syndrome while investigating potential associations with other disease manifestations. In the present study, twenty-seven out of 59 (45.8 %) VEXAS patients showed an inflammatory orbital/ocular involvement during their clinical history. The most frequent orbital/ocular affections were represented by periorbital edema in 8 (13.6 %) cases, episcleritis in 5 (8.5 %) patients, scleritis in 5 (8.5 %) cases, uveitis in 4 (6.8 %) cases, conjunctivitis in 4 (6.8 %) cases, blepharitis in 3 (5.1 %) cases, orbital myositis in 2 (3.4 %) cases. A diagnosis of systemic immune-mediated disease was observed in 15 (55.6 %) cases, with relapsing polychondritis diagnosed in 12 patients. A significant association was observed between relapsing polychondritis and orbital/ocular involvement in VEXAS syndrome (Relative Risk: 2.37, 95 % C.I. 1.03–5.46, p = 0.048). Six deaths were observed in the whole cohort of patients after a median disease duration of 1.2 (IQR=5.35) years, 5 (83.3 %) of which showed orbital/ocular inflammatory involvement. In conclusion, this study confirms that orbital/ocular inflammatory involvement is a common finding in VEXAS patients, especially when relapsing polychondritis is diagnosed. This makes ophthalmologists a key figure in the diagnostic process of VEXAS syndrome. The high frequency of deaths observed in this study seems to suggest that patients with orbital/ocular involvement may require increased attention and more careful follow-up

Concomitant use of tamoxifen with radiotherapy enhances subcutaneous breast fibrosis in hypersensitive patients

Concomitant use of adjuvant tamoxifen (TAM) and radiation therapy (RT) is not widely accepted. We aim to assess whether this treatment is associated with an increased risk of developing subcutaneous fibrosis after conservative or radical surgery in breast cancer patients. We analysed 147 women with breast cancer treated with adjuvant RT, and who were included in the KFS 00539-9-1997/SKL 00778-2-1999 prospective study aimed at evaluating the predictive value of CD4 and CD8 T-lymphocyte apoptosis for the development of radiation-induced late effects. TAM (20 mg day(-1)) with concomitant RT was prescribed in 90 hormone receptor-positive patients. There was a statistically significant difference in terms of complication-relapse-free survival (CRFS) rates at 3 years, 48% (95% CI 37.2-57.6%) vs 66% (95% CI 49.9-78.6%) and complication-free survival (CFS) rates at 2 years, 51% (95% CI 40-61%) vs 80% (95% CI 67-89%) in the TAM and no-TAM groups, respectively. In each of these groups, the CRFS rates were significantly lower for patients with low levels of CD8 radiation-induced apoptosis, 20% (95% CI 10-31.9%), 66% (95% CI 51.1-77.6%), and 79% (95% CI 55-90.9%) for CD8 </=16, 16-24, and >24%, respectively. Similar results were observed for the CFS rates. The concomitant use of TAM with RT is significantly associated with an increased incidence of grade 2 or greater subcutaneous fibrosis; therefore, caution is needed for radiosensitive patients

Septins restrict inflammation and protect zebrafish larvae from Shigella infection

Shigella flexneri, a Gram-negative enteroinvasive pathogen, causes inflammatory destruction of the human intestinal epithelium. Infection by S. flexneri has been well-studied in vitro and is a paradigm for bacterial interactions with the host immune system. Recent work has revealed that components of the cytoskeleton have important functions in innate immunity and inflammation control. Septins, highly conserved cytoskeletal proteins, have emerged as key players in innate immunity to bacterial infection, yet septin function in vivo is poorly understood. Here, we use S. flexneri infection of zebrafish (Danio rerio) larvae to study in vivo the role of septins in inflammation and infection control. We found that depletion of Sept15 or Sept7b, zebrafish orthologs of human SEPT7, significantly increased host susceptibility to bacterial infection. Live-cell imaging of Sept15-depleted larvae revealed increasing bacterial burdens and a failure of neutrophils to control infection. Strikingly, Sept15-depleted larvae present significantly increased activity of Caspase-1 and more cell death upon S. flexneri infection. Dampening of the inflammatory response with anakinra, an antagonist of interleukin-1 receptor (IL-1R), counteracts Sept15 deficiency in vivo by protecting zebrafish from hyper-inflammation and S. flexneri infection. These findings highlight a new role for septins in host defence against bacterial infection, and suggest that septin dysfunction may be an underlying factor in cases of hyper-inflammation

The pathogenic mechanism of the Mycobacterium ulcerans virulence factor, mycolactone, depends on blockade of protein translocation into the ER.

Infection with Mycobacterium ulcerans is characterised by tissue necrosis and immunosuppression due to mycolactone, the necessary and sufficient virulence factor for Buruli ulcer disease pathology. Many of its effects are known to involve down-regulation of specific proteins implicated in important cellular processes, such as immune responses and cell adhesion. We have previously shown mycolactone completely blocks the production of LPS-dependent proinflammatory mediators post-transcriptionally. Using polysome profiling we now demonstrate conclusively that mycolactone does not prevent translation of TNF, IL-6 and Cox-2 mRNAs in macrophages. Instead, it inhibits the production of these, along with nearly all other (induced and constitutive) proteins that transit through the ER. This is due to a blockade of protein translocation and subsequent degradation of aberrantly located protein. Several lines of evidence support this transformative explanation of mycolactone function. First, cellular TNF and Cox-2 can be once more detected if the action of the 26S proteasome is inhibited concurrently. Second, restored protein is found in the cytosol, indicating an inability to translocate. Third, in vitro translation assays show mycolactone prevents the translocation of TNF and other proteins into the ER. This is specific as the insertion of tail-anchored proteins into the ER is unaffected showing that the ER remains structurally intact. Fourth, metabolic labelling reveals a near-complete loss of glycosylated and secreted proteins from treated cells, whereas cytosolic proteins are unaffected. Notably, the profound lack of glycosylated and secreted protein production is apparent in a range of different disease-relevant cell types. These studies provide a new mechanism underlying mycolactone's observed pathological activities both in vitro and in vivo. Mycolactone-dependent inhibition of protein translocation into the ER not only explains the deficit of innate cytokines, but also the loss of membrane receptors, adhesion molecules and T-cell cytokines that drive the aetiology of Buruli ulcer