Extracellular cysteine in connexins: Role as redox sensors

Indexación: Scopus.Connexin-based channels comprise hemichannels and gap junction channels. The opening of hemichannels allow for the flux of ions and molecules from the extracellular space into the cell and vice versa. Similarly, the opening of gap junction channels permits the diffusional exchange of ions and molecules between the cytoplasm and contacting cells. The controlled opening of hemichannels has been associated with several physiological cellular processes; thereby unregulated hemichannel activity may induce loss of cellular homeostasis and cell death. Hemichannel activity can be regulated through several mechanisms, such as phosphorylation, divalent cations and changes in membrane potential. Additionally, it was recently postulated that redox molecules could modify hemichannels properties in vitro. However, the molecular mechanism by which redox molecules interact with hemichannels is poorly understood. In this work, we discuss the current knowledge on connexin redox regulation and we propose the hypothesis that extracellular cysteines could be important for sensing changes in redox potential. Future studies on this topic will offer new insight into hemichannel function, thereby expanding the understanding of the contribution of hemichannels to disease progression.http://journal.frontiersin.org/article/10.3389/fphys.2016.00001/ful

Spatial distribution of the active surveillance of sheep scrapie in Great Britain: an exploratory analysis

<p>Abstract</p> <p>Background</p> <p>This paper explores the spatial distribution of sampling within the active surveillance of sheep scrapie in Great Britain. We investigated the geographic distribution of the birth holdings of sheep sampled for scrapie during 2002 – 2005, including samples taken in abattoir surveys (c. 83,100) and from sheep that died in the field ("fallen stock", c. 14,600). We mapped the birth holdings by county and calculated the sampling rate, defined as the proportion of the holdings in each county sampled by the surveys. The Moran index was used to estimate the global spatial autocorrelation across Great Britain. The contributions of each county to the global Moran index were analysed by a local indicator of spatial autocorrelation (LISA).</p> <p>Results</p> <p>The sampling rate differed among counties in both surveys, which affected the distribution of detected cases of scrapie. Within each survey, the county sampling rates in different years were positively correlated during 2002–2005, with the abattoir survey being more strongly autocorrelated through time than the fallen stock survey. In the abattoir survey, spatial indices indicated that sampling rates in neighbouring counties tended to be similar, with few significant contrasts. Sampling rates were strongly correlated with sheep density, being highest in Wales, Southwest England and Northern England. This relationship with sheep density accounted for over 80% of the variation in sampling rate among counties. In the fallen stock survey, sampling rates in neighbouring counties tended to be different, with more statistically significant contrasts. The fallen stock survey also included a larger proportion of holdings providing many samples.</p> <p>Conclusion</p> <p>Sampling will continue to be uneven unless action is taken to make it more uniform, if more uniform sampling becomes a target. Alternatively, analyses of scrapie occurrence in these datasets can take account of the distribution of sampling. Combining the surveys only partially reduces uneven sampling. Adjusting the distribution of sampling between abattoirs to reduce the bias in favour of regions with high sheep densities could probably achieve more even sampling. However, any adjustment of sampling should take account of the current understanding of the distribution of scrapie cases, which will be improved by further analysis of this dataset.</p

Determination in soils of PAH produced by combustion of biomass under different conditions

4 pages, 2 figures, 2 tables, 25 references.-- Instituto de Recursos Naturales y Agrobiologia, C.S.I.C., Apartado 1052, E-41080 Sevilla, SpainThe nature and concentrations in soils of polynuclear aromatic hydrocarbons (PAH) generated by combustion of pine biomass under different conditions was determined by gas chromatography-mass spectrometry after their enrichment by a simple clean-up procedure. The patterns of pyrogenic PAH, presumably generated by thermal aromatization of biogenic precursors, vary for each sample. When burned at moderate temperature for a long period of time the most abundant homologues generated were alkylated derivatives of naphthalene, whereas phenanthrene alkyl derivatives were predominant after a forest wildfire, where higher temperatures are reached in less time. More condensed PAH included in well-known priority pollutant lists were detected only in minor amounts. No long persistence of PAH was observed in some soil samples analysed.Peer reviewe

Gross morphometry of the heart of the Common marmoset

  The Callithrix jacchus is a Brazilian endemic species that has been widely used asan experimental model in biomedical research. Anatomical data are necessary to support experimental studies with this species. Eleven hearts of C. jacchus from the German Primate Centre (DPZ) have been studied in order to characterize their gross morphometry and compare them with other animal models and human. Biometric data were also obtained. The mean values for morphometry of the hearts did not show any significant difference between male and female. The relative heart weight was similar to human, bovine and equine species. Considering those aspects, the C. jacchus could be used as non-human primate experimental modelfor biomedical studies on heart.

Towards integrated surveillance of zoonoses : spatiotemporal joint modeling of rodent population data and human tularemia cases in Finland

Abstract Background There are an increasing number of geo-coded information streams available which could improve public health surveillance accuracy and efficiency when properly integrated. Specifically, for zoonotic diseases, knowledge of spatial and temporal patterns of animal host distribution can be used to raise awareness of human risk and enhance early prediction accuracy of human incidence. Methods To this end, we develop a spatiotemporal joint modeling framework to integrate human case data and animal host data to offer a modeling alternative for combining multiple surveillance data streams in a novel way. A case study is provided of spatiotemporal modeling of human tularemia incidence and rodent population data from Finnish health care districts during years 1995–2012. Results Spatial and temporal information of rodent abundance was shown to be useful in predicting human cases and in improving tularemia risk estimates in 40 and 75% of health care districts, respectively. The human relative risk estimates’ standard deviation with rodent’s information incorporated are smaller than those from the model that has only human incidence. Conclusions These results support the integration of rodent population variables to reduce the uncertainty of tularemia risk estimates. However, more information on several covariates such as environmental, behavioral, and socio-economic factors can be investigated further to deeper understand the zoonotic relationship

Symptomatic Medial Exostosis of the Great Toe Distal Phalanx: A Complication Due to Over-correction Following Akin Osteotomy for Hallux Valgus Repair

The authors present the case of a 54-year-old female who developed a painful compression lesion localized to the medial aspect of the base of the distal phalanx of the great toe as a complication of hallux valgus surgery. Preoperative radiographic evaluation of the patient's foot revealed the first ray to be longer than the second, a 12 degrees first intermetatarsal angle, a 33 degrees hallux abductus angle, and an exostosis at the medial aspect of the base of the hallux that was not considered by the surgeon to be important. Correction of the hallux valgus deformity was performed with a combination of scarf and Akin osteotomies, and the intermetatarsal and hallux abductus angles reduced to 2 degrees and 8 degrees , respectively. By 2 months postoperative, the patient was complaining of pain at the medial aspect of the distal phalanx of the hallux associated with shoe pressure. The pain correlated both clinically and radiologically with the exostosis at the base of the distal phalanx, and had become symptomatic only after the hallux had been operatively realigned. At 6 months postoperative, percutaneous exostectomy was undertaken to remove the exostosis. Pain relief was complete, thereafter, and after 2 years of postoperative follow-up the patient remained pain free. The clinical importance of a medial exostosis localized to the base of the distal phalanx of the hallux must be taken into consideration whenever hallux valgus correction is undertaken, and this is particularly important whenever an Akin osteotomy is being considered. Level of Clinical Evidence: 4

Spectral and Localization Properties for the One-Dimensional Bernoulli Discrete Dirac Operator

A 1D Dirac tight-binding model is considered and it is shown that its nonrelativistic limit is the 1D discrete Schr?odinger model. For random Bernoulli potentials taking two values (without correlations), for typical realizations and for all values of the mass, it is shown that its spectrum is pure point, whereas the zero mass case presents dynamical delocalization for specific values of the energy. The massive case presents dynamical localization (excluding some particular values of the energy). Finally, for general potentials the dynamical moments for distinct masses are compared, especially the massless and massive Bernoulli cases.Comment: no figure; 24 pages; to appear in Journal of Mathematical Physic

Lab-on-a-chip platforms based on highly sensitive nanophotonic Si biosensors for single nucleotide DNA testing

In order to solve the drawbacks of sensitivity and portability in optical biosensors we have developed ultrasensitive and miniaturized photonic silicon sensors able to be integrated in a "lab-on-a-chip" microsystem platform. The sensors are integrated Mach-Zehnder interferometers based on TIR optical waveguides (Si/SiO2/Si3N4) of micro/nanodimensions. We have applied this biosensor for DNA testing and for detection of single nucleotide polymorphisms at BRCA-1 gene, involved in breast cancer development, without target labeling. The oligonucleotide probe is immobilized by covalent attachment to the sensor surface through silanization procedures. The hybridization was performed for different DNA target concentrations showing a lowest detection limit at 10 pM. Additionally, we have detected the hybridization of different concentrations of DNA target with two mismatching bases corresponding to a mutation of the BRCA-1 gene. Following the way of the lab-on-a-chip microsystem, integration with the microfluidics has been achieved by using a novel fabrication method of 3-D embedded microchannels using the polymer SU-8 as structural material. The optofluidic chip shows good performances for biosensing

Relevance of the Carotid Body Chemoreflex in the Progression of Heart Failure.

Chronic heart failure (CHF) is a global health problem affecting millions of people. Autonomic dysfunction and disordered breathing patterns are commonly observed in patients with CHF, and both are strongly related to poor prognosis and high mortality risk. Tonic activation of carotid body (CB) chemoreceptors contributes to sympathoexcitation and disordered breathing patterns in experimental models of CHF. Recent studies show that ablation of the CB chemoreceptors improves autonomic function and breathing control in CHF and improves survival. These exciting findings indicate that alterations in CB function are critical to the progression of CHF. Therefore, better understanding of the physiology of the CB chemoreflex in CHF could lead to improvements in current treatments and clinical management of patients with CHF characterized by high chemosensitivity. Accordingly, the main focus of this brief review is to summarize current knowledge of CB chemoreflex function in different experimental models of CHF and to comment on their potential translation to treatment of human CHF

3D-Printed transmit-array antenna for broadband backhaul 5G links at V band

The low cost and compactness of transmit-array antennas (TAs) make them attractive for 5G backhaul links. However, the TA advantage is less obvious when considering the broadband operation requirement. Two main factors influence the bandwidth performance, namely: 1) the bandwidth of the unit cells, and 2) the number of 360° phase wrapping zones in the aperture, which are designed for a specific frequency. Herein, we overcome these limitations by using all-dielectric unit cells (inherently broadband) and by developing a general method to quantify and manage the intricate relation between antenna gain, bandwidth, and antenna height. Based on this framework we optimize, as an example, a TA design (focal distance, F=63 mm and aperture diameter D=80 mm ) to comply with typical gain specification for 5G backhaul links (&gt;30 dBi) in the WiGiG band (from 57 to 66 GHz). The feed is a dedicated compact horn (8 ×5×22 mm3) that provides a proper illumination of the aperture. Additive manufacturing is used to simplify the manufacturing process of the antenna. A very good agreement between simulations and experimental results is obtained, achieving good aperture efficiency for this type of antenna (42%), which rivals with existing solutions based on more expensive manufacturing techniques.info:eu-repo/semantics/acceptedVersio