Role of a Novel Tetrodotoxin-Resistant Sodium Channel in the Nitrergic Relaxation of Corpus Cavernosum from the South American Rattlesnake Crotalus Durissus Terrificus

Introduction. Coitus in snakes may last up to 28 hours; however, the mechanisms involved are unknown. Aim. To evaluate the relevance of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP)-phosphodiesterase type 5 (PDE5) system in snake corpus cavernosum reactivity. Methods. Hemipenes were removed from anesthetized South American rattlesnakes (Crotalus durissus terrificus) and studied by light and scanning electronic microscopy. Isolated Crotalus corpora cavernosa (CCC) were dissected from the non-spiny region of the hemipenises, and tissue reactivity was assessed in organ baths. Main Outcome Measures. Cumulative concentration-response curves were constructed for acetylcholine (ACh), sodium nitroprusside (SNP), 5-cyclopropyl-2-[1-(2-fluorobenzyl)-1H-pyrazolo[3,4-b]pyridine-3-yl]pyrimidin-4-ylamine (BAY 41-2272), and tadalafil in CCC precontracted with phenylephrine. Relaxation induced by electrical field stimulation (EFS) was also done in the absence and presence of N omega nitro-L-arginine methyl ester (L-NAME; 100 mu M), 1H-[1, 2, 4] oxadiazolo[4,3-a]quinoxalin-1-one (ODQ; 10 mu M) and tetrodotoxin (TTX; 1 mu M). Results. The hemipenes consisted of two functionally concentric corpora cavernosa, one of them containing radiating bundles of smooth muscle fibers (confirmed by alpha-actin immunostaining). Endothelial and neural nitric oxide synthases were present in the endothelium and neural structures, respectively; whereas soluble guanylate cyclase and PDE5 were expressed in trabecular smooth muscle. ACh and SNP relaxed isolated CCC, with the relaxations being markedly reduced by L-NAME and ODQ, respectively. BAY 41-2272 and tadalafil caused sustained relaxations with potency (pEC(50)) values of 5.84 +/- 0.17 and 5.10 +/- 0.08 (N = 3-4), respectively. In precontracted CCC, EFS caused frequency-dependent relaxations that lasted three times longer than those in mammalian CC. Although these relaxations were almost abolished by either L-NAME or ODQ, they were unaffected by TTX. In contrast, EFS-induced relaxations in marmoset CC were abolished by TTX. Conclusions. Rattlesnake CC relaxation is mediated by the NO-cGMP-PDE5 pathway in a manner similar to mammals. The novel TTX-resistant Na channel identified here may be responsible for the slow response of smooth muscle following nerve stimulation and could explain the extraordinary duration of snake coitus. Capel RO, Monica FZ, Porto M, Barillas S, Muscara MN, Teixeira SA, Arruda AMM, Pissinatti, L, Pissinatti A, Schenka AA, Antunes E, Nahoum C, Cogo JC, de Oliveira MA, and De Nucci G. Role of a novel tetrodotoxin-resistant sodium channel in the nitrergic relaxation of corpus cavernosum from the South American rattlesnake Crotalus durissus terrificus. J Sex Med 2011;8:1616-1625.

Naturally Acquired Antibodies to Plasmodium vivax Duffy Binding Protein (DBP) in Rural Brazilian Amazon

Duffy binding protein (DBP), a leading malaria vaccine candidate, plays a critical role ill Plasmodium vivax erythrocyte invasion. Sixty-eight of 366 (18.6%) subjects had IgG anti-DBP antibodies by enzyme-linked immunosorbent assay (ELISA) in a community-based cross-sectional survey ill the Brazilian Amazon Basin. Despite Continuous exposure to low-level malaria transmission, the overall seroprevalence decreased to 9.0% when the Population was reexamined 12 months later. Antibodies from 16 of 50 (360%) Subjects who were ELISA-positive at the baseline were able to inhibit erythrocyte binding to at least one of two DBP variants tested. Most (13 of 16) of these subjects still had inhibitory antibodies when reevaluated 12 months later. Cumulative exposure to malaria was the strongest predictor of DBP seropositivity identified by Multiple logistic regression models in this population. The poor antibody recognition of DBP elicited by natural exposure to P. vivax in Amazonian populations represents a challenge to be addressed by vaccine development strategies.

Dipeptidyl peptidase IV inhibition attenuates blood pressure rising in young spontaneously hypertensive rats

Objectives The present study aimed to assess the effect of the specific dipeptidyl peptidase IV (DPPIV) inhibitor sitagliptin on blood pressure and renal function in young prehypertensive (5-week-old) and adult spontaneously hypertensive rats (SHRs; 14-week-old). Methods Sitagliptin (40 mg/kg twice daily) was given by oral gavage to young (Y-SHR + IDPPIV) and adult (A-SHR R IDPPIV) SHRs for 8 days. Kidney function was assessed daily and compared with age-matched vehicle-treated SHR (Y-SHR and A-SHR) and with normotensive Wistar-Kyoto rats (Y-WKY and A-WKY). Arterial blood pressure was measured in these animals at the end of the experimental protocol. Additionally, Na(+)/H(+) exchanger isoform 3 (NHE3) function and expression in microvilli membrane vesicles were assessed in young animals. Results Mean arterial blood pressure of Y-SHR + IDPPIV was significantly lower than that of Y-SHR (104 +/- 3 vs. 123 +/- 5 mmHg, P < 0.01) and was similar to Y-WKY (94 +/- 4 mmHg, P > 0.05). Compared to Y-SHR, Y-SHR + IDPPIV exhibited enhanced cumulative urinary flow and sodium excretion and decreased NHE3 activity and expression in proximal tubule microvilli. In the A-SHR, sitagliptin treatment had no significant effect on either renal function or arterial blood pressure. Conclusion Our data suggest that DPPIV inhibition attenuates blood pressure rising in young prehypertensive SHRs, partially by inhibiting NHE3 activity in renal proximal tubule. J Hypertens 29:520-528 (C) 2011 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.

On estimation and influence diagnostics for log-Birnbaum-Saunders Student-t regression models: Full Bayesian analysis

The purpose of this paper is to develop a Bayesian approach for log-Birnbaum-Saunders Student-t regression models under right-censored survival data. Markov chain Monte Carlo (MCMC) methods are used to develop a Bayesian procedure for the considered model. In order to attenuate the influence of the outlying observations on the parameter estimates, we present in this paper Birnbaum-Saunders models in which a Student-t distribution is assumed to explain the cumulative damage. Also, some discussions on the model selection to compare the fitted models are given and case deletion influence diagnostics are developed for the joint posterior distribution based on the Kullback-Leibler divergence. The developed procedures are illustrated with a real data set. (C) 2010 Elsevier B.V. All rights reserved.

TL dosimetry of natural quartz sensitized by heat-treatment and high dose irradiation

The aim of this paper is to report the sensitization of the TL peak appearing at 270 degrees C in the glow curve of natural quartz by using the combined effect of heat-treatments and irradiation with high gamma doses. For this, thirty discs with 6 x 1 mm(2) were prepared from plates parallell to a rhombolledral crystal face. The specimens were separated into four lots according to its TL read out between 160 and 320 degrees C. One lot was submitted to gamma doses of Co-60 radiation starting at 2 kGy and going up until a cumulative dose of 25 kGy. The other three lots were initially heal-treated at 500, 800 and 1000 degrees C and then irradiated with a single dose of 25kGy. The TL response of each lot was determined as a function of test-doses ranging from 0.1 to 30 mGy. As a result, it was observed that heat-treatments themselves did not produce the strong peak at 270 degrees C that was observed after the administration of high gamma doses. This peak is associated with the optical absorption band appearing at 470 rim which is due to the formation of [AlO4]degrees acting as electron-hole recombination centers. The formation of the 270 degrees C peak was preliminary analyzed in relation to aluminum- and oxygen-vacancy-related centers found in crystalline quartz. (C) 2008 Elsevier Ltd. All rights reserved.

Analysis of the combined effect of lasers of different wavelengths for PDT outcome using 600, 630, and 660 nm

We investigated the effects of photodynamic therapy (PDT) outcome when combining three laser systems that produce light in three different wavelengths (600, 630, and 660 nm). Cooperative as well as independent effects can be observed. We compared the results of the combined wavelengths of light with the effect of single laser for the excitation of the photosensitizer. In the current experiment, the used photosensitizer was Photogem (R) (1.5 mg/kg). Combining two wavelengths for PDT, their cumulative dose and different penetrability may change the overall effect of the fluence of light, which can be effective for increasing the depth of necrosis. This evaluation was performed by comparing the depth and specific aspect of necrosis obtained by using single and dual wavelengths for irradiation of healthy liver of male Wistar rats. We used 15 animals and divided them in five groups of three animals. First, Photogem (R) was administered; follow by measurement of the fluorescence spectrum of the liver before PDT to confirm the level of accumulation of photosensitizer in the tissue. After that, an area of 1 cm(2) of the liver was illuminated using different laser combinations. Qualitative analysis of the necrosis was carried out through histological and morphological study. [GRAPHICS] (a) - microscopic images of rat liver cells, (b) - superficial necrosis caused by PDT using dual-wavelength illumination, (c) - neutrophilic infiltration around the vessel inside the necrosis, and (d) - neutrophilic infiltration around the vessel between necrosis and live tissue (C) 2011 by Astro Ltd. Published exclusively by WILEY-VCH Verlag GmbH & Co. KGaA

Archaeological Mounds in Marajo Island in Northern Brazil: A Geological Perspective Integrating Remote Sensing and Sedimentology

Earthen mounds with archaeological artifacts have been well known in Marajo Island since the 19th century. Their documented dimensions are impressive, e.g., up to 20m high, and with areas large as 90 ha. The mounds, locally known as lesos, impose a significant. relief on the very low-lying landscape of this region, which averages 4 to 6 in above present. sea level. These features have been traditionally interpreted as artificial constructions of the Marajoara culture, designed for defense, cemetery purposes, or escape from flooding. Here, we provide sedimentological and geomorphological data that suggest an alternative origin for these structures that is more consistent with their monumental sizes. Rather than artificial, the Marajoara tesos seem to consist of natural morphological features related to late Pleistocene and Holocene fluvial, and possibly tidal-influenced, paleochannels and paleobars that became abandoned as depositional conditions changed through dine. Although utilized and modified by the Marajoara since at least 2000 years ago, these earthen mounds contain a significant non-anthropogenically modified sedimentary substratum. Therefore, the large Marajoara tesos are not entirely artificial. Ancient, Marajoara cultures took advantage of these natural, preexisting elevated surfaces to base their communities and develop their activities, locally increasing the sizes of these fluvial landforms. This alternative interpretation suggests less cumulative labor investment, in the construction of the mounds and might. have significant implications for reconstructing the organization of the Marajoara culture. (C) 2009 Wiley Periodicals, Inc.

A simple relation between the Leimkuhler curve and the mean residual life

In this paper, a simple relation between the Leimkuhler curve and the mean residual life is established. The result is illustrated with several models commonly used in informetrics, such as exponential, Pareto and lognormal. Finally, relationships with some other reliability concepts are also presented. (C) 2010 Elsevier Ltd. All rights reserved.

A new class of survival regression models with heavy-tailed errors: robustness and diagnostics

Birnbaum-Saunders models have largely been applied in material fatigue studies and reliability analyses to relate the total time until failure with some type of cumulative damage. In many problems related to the medical field, such as chronic cardiac diseases and different types of cancer, a cumulative damage caused by several risk factors might cause some degradation that leads to a fatigue process. In these cases, BS models can be suitable for describing the propagation lifetime. However, since the cumulative damage is assumed to be normally distributed in the BS distribution, the parameter estimates from this model can be sensitive to outlying observations. In order to attenuate this influence, we present in this paper BS models, in which a Student-t distribution is assumed to explain the cumulative damage. In particular, we show that the maximum likelihood estimates of the Student-t log-BS models attribute smaller weights to outlying observations, which produce robust parameter estimates. Also, some inferential results are presented. In addition, based on local influence and deviance component and martingale-type residuals, a diagnostics analysis is derived. Finally, a motivating example from the medical field is analyzed using log-BS regression models. Since the parameter estimates appear to be very sensitive to outlying and influential observations, the Student-t log-BS regression model should attenuate such influences. The model checking methodologies developed in this paper are used to compare the fitted models.

Omvårdnadsbehov i form av stöd hos kvinnor med bröstcancer : En systematisk litteraturstudie

Föreliggande systematiska litteraturstudie syftade till att samla information och söka evidens för bröstcancerdrabbade kvinnors omvårdnadsbehov från sjuksköterskans i form av stöd för psykiska, sociala eller informativa behov. Sexton vetenskapliga artiklar valdes ut via databasen CINAHL (Cumulative Index to Nursing and Allied Health Literature) och fulltextdatabasen ELIN (Elecronic Library Information Navigator) för vidare granskning. Till sökningen användes sökorden breast*, cancer*, nurs* och support. Alla utvalda artiklar som härrör till syftet kvalitetsbedömdes genom på förhand bestämda granskningskriterier från modifierade förlagor efter Forsberg och Wengström (2003) och Willman, Bahtsevani och Stoltz (2007). Av resultatet framkom det att det fanns stark evidens för att kvinnor med bröstcancer har ett omvårdnadsbehov av socialt stöd, psykiskt stöd och även av information av sjuksköterskan. Omvårdnadsbehov som även kom fram i denna studie är kontinuitet i vården och personliga samtal med sjuksköterskan. Att få utöva sin religiösa tro, sin andlighet och utöva sin kulturella tillhörighet samt likaså känna förtroende är omvårdnadsbehov som blev uppenbarat i resultatet. Resultatet diskuterades utifrån Aaron Antonovskys omvårdnadsteori där känslan av sammanhang är central.

Omvårdnadsbehov hos anhörigavars familjemedlemfår palliativ vård i hemmet

Föreliggande systematiska litteraturstudies syfte var att beskriva anhörigas upplevelser och deras omvårdnadsbehov då en familjemedlem vårdades palliativt i hemmet, för att skapa en förståelse för vad sjuksköterskan kan bidra med. Sökord som valdes var palliative AND relative* AND home för insamling av vetenskapliga artiklar via fulltextdatabasen Electronic Library Information Navigator (ELIN) och databasen Cumulative Index of Nursing and Allied Health (CINAHL). En systematisk kvalitetsgranskning gjordes på 15 vetenskapliga artiklar enligt modifierade kvalitetsgranskningsmallar efter förlagor av Forsberg och Wengström (2003) och Willman et al. (2006) och på basen av kvalitetsresultatet evidensgraderades de anhörigas till familjemedlem i det palliativa skedets omvårdnadsbehov. Tre omvårdnadsbehov som vilade på starkt vetenskapligt underlag framkom: att få professionellt stöd, att få avlastning som anhörig eller anhörigvårdare till en familjemedlem som vårdas palliativt i hemmet och att få information och undervisning om familjemedlemmens situation. Vidare framkom ett omvårdnadsbehov som vilade på måttligt vetenskapligt underlag: att få dela sina upplevelser med andra anhöriga i liknande situation. Resultatet diskuterades utifrån Joyce Travelbees teori om empati eller förmågan att sätta sig in i den andres psykologiska tillstånd och sympati det vill säga förmågan att förmedla till patienten att han/hon inte är ensam i sin tunga situation. Med hjälp av föreliggande studies resultat kan sjuksköterskan få en bättre bild av sina omvårdnadsuppgifter och kan förankra sina insikter teoretiskt i Travelbees tankekonstruktion.

Omvårdnadsbehov hospatienter med diabetesmellitus typ 2 : En systematisk litteraturstudie

Föreliggande systematiska litteraturstudie syftade till att klarlägga vilka omvårdnadsbehov som föreligger hos patienter med typ 2-diabetes. Sammanlagt 15 vetenskapliga artiklar valdes ut via sökmotorn Electronic Library Information Navigator (ELIN), databasen Cumulative Index of Nursing and Allied Health (CINAHL) samt sökmotorn och databasen för medicinska artiklar som drivs av United States National Library of Medicine (MEDLINE), för vidare granskning. Sökorden type 2 diabetes AND quality of life AND nurs* användes. Alla titlar lästes, om titeln verkade relevant för forskningsområdet lästes även abstraktet. Kvalitetsgranskning av artiklarna genomfördes efter granskningsmallar med 28 bedömningskriterier. Omvårdnadsbehoven hos patienter med typ 2-diabetes som framkom vid artikel granskningen evidensgraderades på basen av kvalitetsgranskningen med hjälp av graderingsskala. Resultatet visade att hjälp till förbättrad egenvård, önskan om utökad utbildning, information och kunskap, socialt stöd och kontinuerlig vårdkontakt var de omvårdnadsbehov som studien fann evidens för. Omvårdnadsbehov hos patienter med typ 2-diabetes som framkom var kända sedan tidigare men föreliggande studie säkrade evidensen för dessa. Resultatet diskuterades utifrån Virginia Hendersons omvårdnadsteori där omvårdnaden måste ha en utgångspunkt i individens egna upplevelser av sina behov och hur dessa behov på bästa sätt kan tillfredsställas. Med hjälp av studiens resultat sammanlänkat med Virginia Hendersons teori om individens omvårdnadsbehov kan sjuksköterskan få en bättre bild av vilka behov som föreligger hos patienter med typ 2-diabetes för att bevara deras livskvalité.

Faktorer som påverkar samtal med patienter ur ett tvärkulturellt perspektiv

Syfte: Syftet med denna litteraturöversikt var att beskriva vad det kunde finnas för faktorer som påverkade genomförandet av ett samtal med patienter ur ett tvärkulturellt perspektiv. Metod: Studien genomfördes som en litteraturöversikt. Artiklar söktes ur databaserna: PubMed, CINAHL (Cumulative Index to Nursing and Allied Health Literature), Wiley online library samt Science Direct. Resultat: Resultatet visade på att kommunikation i det tvärkulturella mötet var beroende av en kulturell kompetens hos hälso- och sjukvårdspersonalen. Vidare visade resultatet på brister i hälso- och sjukvårdspersonalens kulturella kompetens, samt att det i sjuksköterskeutbildningen saknades specifik utbildning inom kulturell kompetens. Forskare, hälso- och sjukvårdspersonal och sjuksköterskestudenter efterfrågade mer utbildning inom detta ämne. Slutsatser: Kommunikation inom den tvärkulturella vården visade sig vara ett svårt ämne, med många aspekter att ta hänsyn till. Det ansågs av stor vikt i det mångkulturella samhället att personal inom hälso- och sjukvård får kulturell kompetens för att ha möjlighet att kommunicera med patienter oberoende av härkomst. Därför ansågs det viktigt att skapa vidareutbildningar för hälso- och sjukvårdspersonal, samt se över sjuksköterskeutbildningens utbildningsplan.

Mobile Assisted Language Learning : A Literature Review

Mobile assisted language learning (MALL) is a subarea of the growing field of mobile learning (mLearning) research which increasingly attracts the attention of scholars. This study provides a systematic review of MALL research within the specific area of second language acquisition during the period 2007 - 2012 in terms of research approaches, methods, theories and models, as well as results in the form of linguistic knowledge and skills. The findings show that studies of mobile technology use in different aspects of language learning support the hypothesis that mobile technology can enhance learners’ second language acquisition. However, most of the reviewed studies are experimental, small-scale, and conducted within a short period of time. There is also a lack of cumulative research; most theories and concepts are used only in one or a few papers. This raises the issue of the reliability of findings over time, across changing technologies, and in terms of scalability. In terms of gained linguistic knowledge and skills, attention is primarily on learners’ vocabulary acquisition, listening and speaking skills, and language acquisition in more general terms.

Wind farm construction impacts reindeer migration and movement corridors

Over the last decade, we have seen a massive increase in the construction of wind farms in northern Fennoscandia. Wind farms comprising hundreds of wind turbines are being built, with little knowledge of the possible cumulative adverse effects on the habitat use and migration of semi-domesticated free-ranging reindeer. We assessed how reindeer responded to wind farm construction in an already fragmented landscape, with specific reference to the effects on use of movement corridors and reindeer habitat selection. We used GPS-data from reindeer during calving and post-calving in the MalAyen reindeer herding community in Sweden. We analysed data from the pre-development years compared to the construction years of two relatively small wind farms. During construction of the wind farms, use of original migration routes and movement corridors within 2 km of development declined by 76 %. This decline in use corresponded to an increase in activity of the reindeer measured by increased step lengths within 0-5 km. The step length was highest nearest the development and declining with distance, as animals moved towards migration corridors and turned around or were observed in holding patterns while not crossing. During construction, reindeer avoided the wind farms at both regional and landscape scale of selection. The combined construction activities associated with even a few wind turbines combined with power lines and roads in or close to central movement corridors caused a reduction in the use of such corridors and grazing habitat and increased the fragmentation of the reindeer calving ranges.