NADPH-diaphorase-stained neurons after experimental epilepsy in rats

The aim of this study was to determine the neuronal participation of nitric oxide (NO) in experimental epilepsy. To reach this objective, we established the amount of cells presenting nitric oxide synthase (NOS) and the amygdaline concentrations in the L-arginine-nitric oxide synthesis pathway. A group of fully epileptic rats, induced by the kindling procedure and that had reached at least 10 generalized seizures, was studied. We evaluated behavioral stages, electroencephalographic activities, and histochemical NOS-positive cells and carried out high-pressure liquid chromatography (HPLC) determinations of arginine, citrulline, and glutamic acid. Our results showed that behavioral and electrographic frequency, and duration of epileptic activities, were increased during the kindling process. Image processing system of NOS cells showed two types of intensities in cell stains in hippocampus, caudate-putamen, and amygdala. When we independently counted the two types of NOS stain cells, a selective increase in the number and density of weak-stained cells was observed, while dark-stained cells did not change in the studied structures. Additionally, arginine, citrulline, and glutamic acid concentrations in amygdala increased in kindled animals. The differential and specific increase in the stained cells expressing the nitric oxide synthase, as well as the increase in concentrations of the L-arginine-nitric oxide pathway in amygdala, suggested a relationship with the progressive augmentation in the electrophysiological hyperactivity characteristic of generalized epilepsy.     

One-Step Chemical Synthesis of Native Met1-Linked Poly-Ubiquitin Chains

The enzyme-mediated construction of poly-ubiquitin (Ub) chains on target proteins leads to a variety of cellular responses and is involved in processes ranging from protein degradation to cell cycle control and immune responses. This complex post-translational modification system is under intense investigation, but generation of specific Ub chains and tools made thereof is not always trivial. We discovered that native methionine-1-linked polymeric ubiquitin chains can be constructed in a single chemical reaction. We validate correct folding and regioselective attachment of such chains using linkage specific proteases and further demonstrate that these poly-Ub chains can be converted into thioesters by the activating E1-enzyme. Subsequent ligation reactions using these in situ prepared thioesters leads to poly-ubiquitinated peptides.     

Genome and proteome annotation: organization, interpretation and integration

Recent years have seen a huge increase in the generation of genomic and proteomic data. This has been due to improvements in current biological methodologies, the development of new experimental techniques and the use of computers as support tools. All these raw data are useless if they cannot be properly analysed, annotated, stored and displayed. Consequently, a vast number of resources have been created to present the data to the wider community. Annotation tools and databases provide the means to disseminate these data and to comprehend their biological importance. This review examines the various aspects of annotation: type, methodology and availability. Moreover, it puts a special interest on novel annotation fields, such as that of phenotypes, and highlights the recent efforts focused on the integrating annotations.     

Maintenance therapy with interferon alfa 2b in Hodgkin's disease

We performed a randomized clinical trial to assess the efficacy and toxicity of interferon alfa 2b (IFN) as maintenance therapy in patients with advanced Hodgkin's disease in complete remission (CR) after conventional chemotherapy. One hundred and thirty-five patients (stage IIIB-IV B) were initially treated with EBVD (epirubicin, bleomycin, vinblastine, dacarbazine). IF CR was achieved they were randomly assigned to receive either maintenance therapy with IFN 5.0 MU three times a week for one year or no further treatment (control group). Clinical and laboratory characteristics at diagnosis were quite similar in both groups. After a median follow-up of 74.3 months (range 49 to 108), 61 out of 68 patients (91%; 95% confidence interval (CI): 76% to 97%) remain in first complete remission in the IFN-treated group compared to 38 out of 67 (58%; 95% CI: 49% to 71%) in the control group (p<.01). Overall survival was also better in the IFN treated group: 62 patients (92%; 95% CI: 82% to 97%) are alive free of disease at 7-years compared to 40 patients (67%, 95%: 55% to 76%) in the control group (p<.01). Toxicity secondary to IFN administration was mild and no dose modification was necessary during treatment. All patients received the planned dose of IFN. This was not an intent-to treat analysis. IFN administration as maintenance therapy was appears to be the only cause of improvement in outcome in these patients. We feel that IFN should be considered as maintenance therapy in patients with advanced Hodgkin's disease because this treatment improves the final outcome without the excessive toxicities of more aggressive therapeutic approaches such as bone marrow transplantation during first CR. We hope that IFN will be considered in future randomized clinical trials in order to define it's role in the treatment of Hodgkin's disease.     

Occurrence of urolithins,gut microbiota ellagic acid metabolites and proliferation markers expression response in the human prostate gland upon consumption of walnuts and pomegranate juice

Epidemiology supports the important role of nutrition in prostate cancer (PCa) prevention. Pomegranate juice (PJ) exerts protective effects against PCa, mainly attributed to PJ ellagitannins (ETs). Our aim was to assess whether ETs or their metabolites ellagic acid and urolithins reach the human prostate upon consumption of ET‐rich foods and to evaluate the effect on the expression of three proliferation biomarkers. Sixty‐three patients with BPH or PCa were divided into controls and consumers of walnuts (35 g walnuts/day) or pomegranate (200 mL PJ/day) for 3 days before surgery. Independently of the ETs source, the main metabolite detected was urolithin A glucuronide, (3,8‐dihydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) (up to 2 ng/g) together with the traces of urolithin B glucuronide, (3‐hydroxy‐6H‐dibenzo[b,d]pyran‐6‐one glucuronide) and dimethyl ellagic acid. The small number of prostates containing metabolites was likely caused by clearance of the compounds during the fasting. This was corroborated in a parallel rat study and thus the presence of higher quantities of metabolites at earlier time points cannot be discarded. No apparent changes in the expression of CDKN1A, MKi‐67 or c‐Myc were found after consumption of the walnuts or PJ. Our results suggest that urolithin glucuronides and dimethyl ellagic acid may be the molecules responsible for the beneficial effects of PJ against PCa.     

Address Generation Optimization for Embedded High-Performance Processors: A Survey

Nowadays embedded systems are growing at an impressive rate and provide more and more sophisticated applications characterized by having a complex array index manipulation and a large number of data accesses. Those applications require high performance specific computation that general purpose processors can not deliver at a reasonable energy consumption. Very long instruction word architectures seem a good solution providing enough computational performance at low power with the required programmability to speed up the time to market. Those architectures rely on compiler effort to exploit the available instruction and data parallelism to keep the data path busy all the time. With the density of transistors doubling each 18 months, more and more sophisticated architectures with a high number of computational resources running in parallel are emerging. With this increasing parallel computation, the access to data is becoming the main bottleneck that limits the available parallelism. To alleviate this problem, in current embedded architectures, a special unit works in parallel with the main computing elements to ensure efficient feed and storage of the data: the address generator unit, which comes in many flavors. Future architectures will have to deal with enormous memory bandwidth in distributed memories and the development of address generators units will be crucial for effective next generation of embedded processors where global trade-offs between reaction-time, bandwidth, energy and area must be achieved. This paper provides a survey of methods and techniques that optimize the address generation process for embedded systems, explaining current research trends and needs for future.

Silica nanoparticles inhibit the cation channel TRPV4 in airway epithelial cells

Background

Silica nanoparticles (SiNPs) have numerous beneficial properties and are extensively used in cosmetics and food industries as anti-caking, densifying and hydrophobic agents. However, the increasing exposure levels experienced by the general population and the ability of SiNPs to penetrate cells and tissues have raised concerns about possible toxic effects of this material. Although SiNPs are known to affect the function of the airway epithelium, the molecular targets of these particles remain largely unknown. Given that SiNPs interact with the plasma membrane of epithelial cells we hypothesized that they may affect the function of Transient Receptor Potential Vanilloid 4 (TRPV4), a cation-permeable channel that regulates epithelial barrier function. The main aims of this study were to evaluate the effects of SiNPs on the activation of TRPV4 and to determine whether these alter the positive modulatory action of this channel on the ciliary beat frequency in airway epithelial cells.

Results

Using fluorometric measurements of intracellular Ca²⁺ concentration ([Ca²⁺]_i) we found that SiNPs inhibit activation of TRPV4 by the synthetic agonist GSK1016790A in cultured human airway epithelial cells 16HBE and in primary cultured mouse tracheobronchial epithelial cells. Inhibition of TRPV4 by SiNPs was confirmed in intracellular Ca²⁺ imaging and whole-cell patch-clamp experiments performed in HEK293T cells over-expressing this channel. In addition to these effects, SiNPs were found to induce a significant increase in basal [Ca²⁺]_i, but in a TRPV4-independent manner. SiNPs enhanced the activation of the capsaicin receptor TRPV1, demonstrating that these particles have a specific inhibitory action on TRPV4 activation. Finally, we found that SiNPs abrogate the increase in ciliary beat frequency induced by TRPV4 activation in mouse airway epithelial cells.

Conclusions

Our results show that SiNPs inhibit TRPV4 activation, and that this effect may impair the positive modulatory action of the stimulation of this channel on the ciliary function in airway epithelial cells. These findings unveil the cation channel TRPV4 as a primary molecular target of SiNPs.

     

Activation of Drosophila melanogaster TRPA1 Isoforms by Citronellal and Menthol

Background: The transient receptor potential ankyrin 1 (TRPA1) cation channels function as broadly-tuned sensors of noxious chemicals in many species. Recent studies identified four functional TRPA1 isoforms in Drosophila melanogaster (dTRPA1(A) to (D)), but their responses to non-electrophilic chemicals are yet to be fully characterized. Methods: We determined the behavioral responses of adult flies to the mammalian TRPA1 non-electrophilic activators citronellal and menthol, and characterized the effects of these compounds on all four dTRPA1 channel isoforms using intracellular Ca²⁺ imaging and whole-cell patch-clamp recordings. Results: Wild type flies avoided citronellal and menthol in an olfactory test and this behavior was reduced in dTrpA1 mutant flies. Both compounds activate all dTRPA1 isoforms in the heterologous expression system HEK293T, with the following sensitivity series: dTRPA1(C) = dTRPA1(D) > dTRPA1(A) ≫ dTRPA1(B) for citronellal and dTRPA1(A) > dTRPA1(D) > dTRPA1(C) > dTRPA1(B) for menthol. Conclusions: dTrpA1 was required for the normal avoidance of Drosophila melanogaster towards citronellal and menthol. All dTRPA1 isoforms are activated by both compounds, but the dTRPA1(B) is consistently the least sensitive. We discuss how these findings may guide further studies on the physiological roles and the structural bases of chemical sensitivity of TRPA1 channels.     

Leveraging agriculture to improve nutrition in the Philippines

The typical Filipino diet mainly consists of rice, fish and vegetables, with rice being the greatest source of calories. The consumption of a maize, starchy roots and tubers as rice substitutes or supplements, and vegetables and fruits has generally declined, while the consumption of fats, oils and meats has increased. Stunting is the most prevalent form of malnutrition among Filipinos. Vitamin A Deficiency, Iodine Deficiency Disorder, and Iron Deficiency Anemia remain public health problems for children and pregnant and lactating women. The link between nutrition and agriculture in the Philippines has focused on leveraging agriculture to improve nutrition. The programs that had been initiated by the government, NGO/CSO or private sector were conceptualized and implemented before the elements of a nutrition-sensitive agriculture framework were identified. These programs were implemented to address food production and the nutritional needs of individuals, families, and communities only with reference to nutrition security. Many of these programs have been successful as they implemented best practices that could be applied to forge a superior approach that optimizes the agriculture-nutrition nexus. This study identified these best practices or elements of success. The elements that have been noted as reasons for the success of some of these programs are: presence of strong political will and enabling policy environment; forging of new forms of partnerships, strategic collaboration, sound coordination and structures; exploiting the best that science and technology could offer; democratizing community participation; strong capacity building component and access to reliable technical expertise; knowledge and sensitivity to local cultures, beliefs and practices; professionalized promotion and ‘messaging’; use of catchy terms for easy recall; availability of sustainable funding; use of the life cycle approach in nutrition; holistic community nutrition perspective; practice and promotion of biodiversity-based agricultural production system; and control of the means of production.     

Silica Nanoparticles Inhibit Responses to ATP in Human Airway Epithelial 16HBE Cells

Because of their low cost and easy production, silica nanoparticles (SiNPs) are widely used in multiple manufacturing applications as anti-caking, densifying and hydrophobic agents. However, this has increased the exposure levels of the general population and has raised concerns about the toxicity of this nanomaterial. SiNPs affect the function of the airway epithelium, but the biochemical pathways targeted by these particles remain largely unknown. Here we investigated the effects of SiNPs on the responses of 16HBE14o- cultured human bronchial epithelial (16HBE) cells to the damage-associated molecular pattern ATP, using fluorometric measurements of intracellular Ca²⁺ concentration. Upon stimulation with extracellular ATP, these cells displayed a concentration-dependent increase in intracellular Ca²⁺, which was mediated by release from intracellular stores. SiNPs inhibited the Ca²⁺ responses to ATP within minutes of application and at low micromolar concentrations, which are significantly faster and more potent than those previously reported for the induction of cellular toxicity and pro-inflammatory responses. SiNPs-induced inhibition is independent from the increase in intracellular Ca²⁺ they produce, is largely irreversible and occurs via a non-competitive mechanism. These findings suggest that SiNPs reduce the ability of airway epithelial cells to mount ATP-dependent protective responses.