bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for xylem embolism as a primary factor in dehydration‐induced declines in leaf hydraulic conductance
Authors: JOHNSON DANIEL M. , MCCULLOH KATHERINE A. , WOODRUFF DAVID R. , MEINZER FREDERICK C.
Published: October 2011

Hydraulic conductance of leaves (Kleaf) typically decreases with increasing water stress and recent studies have proposed different mechanisms responsible for decreasing Kleaf. We measured Kleaf concurrently with ultrasonic acoustic emissions (UAEs) in dehydrating leaves of several species to determine whether declining Kleaf was associated with xylem embolism. In addition, we performed experiments in which the surface tension of water in the leaf xylem was reduced by using a surfactant solution. Finally, we compared the hydraulic vulnerability of entire leaves with the leaf lamina in three species.

Leaf hydraulic vulnerability based on rehydration kinetics and UAE was very similar, except in Quercus garryana. However, water potentials corresponding to the initial decline in Kleaf and the onset of UAE in Q. garryana were similar. In all species tested, reducing the surface tension of water caused Kleaf to decline at less negative water potentials compared with leaves supplied with water. Microscopy revealed that as the fraction of embolized xylem increased, Kleaf declined sharply in Q. garryana. Measurements on leaf discs revealed that reductions in lamina hydraulic conductance with dehydration were not as great as those observed in intact leaves, suggesting that embolism was the primary mechanism for reductions in Kleaf during dehydration.
Phylogeny and immune evasion: a putative correlation for cerebral Pseudallescheria/Scedosporium infections*
Authors: Rainer Johannes , Rambach Günter , Kaltseis Josef , Hagleitner Magdalena , Heiss Silvia , Speth Cornelia
Published: October 2011

Representatives of the genus Pseudallescheria (anamorph: Scedosporium) are saprobes and the aetiologic agent of invasive mycosis in humans. After dissemination, the central nervous system (CNS) is one of the most affected organs. Prerequisites for the survival of Pseudallescheria/Scedosporium in the host are the ability to acquire nutrients and to evade the immune attack. The cleavage of complement compounds via the secretion of fungal proteases might meet both challenges since proteolytic degradation of proteins can provide nutrients and destroy the complement factors, a fast and effective immune weapon in the CNS. Therefore, we studied the capacity of different Pseudallescheria/Scedosporium species to degrade key elements of the complement cascade in the cerebrospinal fluid and investigated a correlation with the phylogenetic background. The majority of the Pseudallescheria apiosperma isolates tested were demonstrated to efficiently eliminate proteins like complement factors C3 and C1q, thus affecting two main components of a functional complement cascade, presumably by proteolytic degradation, and using them as nutrient source. In contrast, the tested strains of Pseudallescheria boydii have no or only weak capacity to eliminate these complement proteins. We hypothesise that the ability of Pseudallescheria/Scedosporium strains to acquire nutrients and to undermine the complement attack is at least partly phylogenetically determined.
Effects of oxygenation and luminal flow on human placenta chorionic plate blood vessel function
Authors: Wareing Mark
Published: October 2011

Aim:  The human fetoplacental vasculature has been suggested to be a low resistance/high flow system, but the mechanisms by which this state is achieved are unclear.

Methods:  This study assessed the effects of intraluminal flow and local oxygenation on isolated human placental chorionic plate arteries and veins at term using pressure myography.

Results:  Chorionic plate arteries and veins exhibit myogenic tone. A small but significant arterial vasodilatation was observed following exposure to hypoxia; chorionic plate veins contracted to a similar hypoxic stimulus. Under physiological conditions of pressure and oxygenation, increased luminal flow induced contraction in both chorionic plate arteries and veins. [Correction added after online publication 15th November 2011: ‘induced vasodilatation’ has been changed to ‘induced contraction’]

Conclusions:  Human fetoplacental vascular tone can be manipulated by local physical factors.
Development of a scale for pregnancy‐related discomforts
Authors: Shinkawa Haruko , Shimada Mieko , Hirokane Kazue , Hayase Mako , Inui Tsubura
Published: October 2011

Aim:  The purpose of this study was to develop a new scale of pregnancy‐related discomforts for evaluating expectant women's psychosomatic states during each trimester.

Methods:  The study population comprised 786 expectant women (response rate: 38.2%) who underwent antenatal examinations in 13 hospitals located in eight regions of Japan. Respondents answered questions about the incidence of 95 well‐known symptoms related to pregnancy. Responses were divided into three groups based on the gestational period. Three scales were then prepared based on item and factor analyses, and reliability and validity were confirmed.

Results:  The resultant global scales for the first, second, and third trimester consisted of 15, 13, and 13 items, respectively. The three global scales could be divided into three, three, and two subscales, respectively. The reliability coefficients of the global and subscales were 0.7 or more. Validity was confirmed by the conventional group method.

Conclusions:  This is the first study to develop scales for pregnancy‐related discomforts in Japanese women in order to evaluate psychosomatic states during each trimester of pregnancy. Because the number of scale items had decreased by more than half as compared to previous scales, this new, more feasible scale may be useful in clinical settings.
Antenatal sonographic features of ileal atresia
Authors: Jo Yun Sung , Jang Dong Gyu , Nam Sun Young , Choi Sae Kyung , Shin Jong Chul , Lee Guisera
Published: October 2011

Aim:  The purpose of this study was to determine the antenatal sonographic features of ileal atresia.

Material and Methods:  We identified neonates with surgically‐confirmed ileal atresia who had antenatal sonography performed in our institution between 1 January 1999 and 30 June 2009. The antenatal sonography images and reports were reviewed.

Results:  Sixteen neonates had surgically‐confirmed ileal atresia in our institution in 11 years. Seven fetuses (43.7%) did not have any intestinal abnormalities detected antenatally on ultrasonography. Nine fetuses (56.3%) had various sonographic features of ileal atresia, including multiple dilated bowel loops, ascites, cysts, and polyhydramnios with or without associated anomalies. Six of nine fetuses had multiple dilated bowel loops and two fetuses had ascites. One fetus had a large, cystic, mixed, echogenic dilatation of bowel. Polyhydramnios was present in three fetuses. Heart anomalies, kidney anomalies, or hydrops were present in four fetuses. Eight of 16 fetuses (50%) had other intestinal problems, including intussusceptions in one fetus, small bowel malrotation, meconium pseudocyst volvulus, meconium peritonitis, and a congenital band.

Conclusion:  The prenatal sonographic features of ileal atresia are not simple. Various sonographic findings are shown and ileal atresia was detected in about 60% of cases.
Is 30‐day mortality an appropriate measure of risk in elderly patients undergoing elective colorectal resection?
Authors: Mamidanna R. , Almoudaris A. M. , Faiz O.
Published: October 2011

Aim  The study aimed to define mortality in the elderly following elective colorectal resection and to identify the most meaningful postoperative period to report mortality rates in this group of patients.

Method  A systematic review was undertaken to identify studies that reported on mortality in the elderly following elective colorectal resection. Searches of MEDLINE, Embase and PubMed databases were carried out by two independent reviewers and the results were collated. Two reviewers conducted literature searches independently and the third reviewer acted as an arbiter in case of discordance.

Results  Two‐hundred and thirty‐six studies published in 2000 or later were identified in the search. Studies were excluded if they included emergency surgery, included patients receiving surgery before 1995, or did not comment on mortality in an elderly age group. Seventeen studies were finally included in the review. Thirty‐day or postoperative mortality rates varied from 0 to 13.3%. Short‐term mortality was low in elderly patients selected for minimal access surgery. National population and registry observational audits reported higher short‐term mortality rates than most small case series or cohort studies. One national audit demonstrated that a significant mortality risk persists for up to 1 year after surgery.

Conclusion  Historical case series suggest that 30‐day mortality following colorectal resection in the elderly is low. The reliability of 30‐day mortality measures to reflect surgical success in this cohort is, however, questionable as a significant proportion of patients die in the months following surgery.
Investigating Deaf Children's Vocabulary Knowledge in British Sign Language
Authors: Mann Wolfgang , Marshall Chloë
Published: October 2011

This study explores different aspects of the mapping between phonological form and meaning of signs in British Sign Language (BSL) by means of four tasks to measure meaning recognition, form recognition, form recall, and meaning recall. The aim was to investigate whether there is a hierarchy of difficulty for these tasks and, therefore, whether BSL vocabulary acquisition proceeds incrementally, as is the case for spoken languages. Twenty‐four deaf participants (aged 5–15 years), all of whom were BSL users, performed with greatest accuracy on meaning recognition and least accurately on meaning recall. The results indicate that signers’ knowledge of mapping between form and meaning in BSL signs is not an all‐or‐nothing phenomenon but depends on what the learner is required to do with that knowledge, as is the case for spoken languages.
Utility of desmoglein ELISA in the clinical correlation and disease monitoring of pemphigus vulgaris
Authors: Anand V. , Khandpur S. , Sharma V.K. , Sharma A.
Published: October 2011

Background  Pemphigus vulgaris (PV) is a relatively common autoimmune blistering disease in India. Recently, enzyme‐linked immunosorbent assay (ELISA) test against desmoglein1 (Dsg 1) and desmoglein3 (Dsg 3) has been developed, which is found to be highly sensitive and specific.

Objective  To assess the utility of ELISA for monitoring the disease of PV.

Methods  Serum samples from 63 active PV patients were tested for anti‐Dsg1 and anti‐Dsg3 using ELISA. They were tested for anti‐Dsg1 and anti‐Dsg3 reactivity before treatment. The test was performed during remission period and after relapse using commercially available ELISA kit.

Results  Both anti‐Dsg1 and anti‐Dsg3 levels were found to be raised in PV patients. Thirty‐eight patients went on remission during treatment phase with mean anti‐Dsg1 and anti‐Dsg3 values, 13.18 U/mL and 18.89 U/mL respectively. Difference of baseline from remission was found to be significant (P < 0.001). Of these, 23 patients relapsed either during treatment phase or after stoppage of therapy and their mean anti‐Dsg1 and anti‐Dsg3 titres were 39.49 U/mL and 96.99 U/mL respectively. Difference of remission from relapse was also found to be significant (P < 0.001). The 50 U/mL cut‐off for anti‐Dsg1 ELISA provided 73.91% sensitivity and 72.5% specificity respectively. The 98.57 U/mL cut‐off for anti‐Dsg3 provided 82.61% sensitivity and 82.5% specificity respectively.

Conclusion  ELISA is less time consuming, less expensive and a potential diagnostic test for PV. It is also highly sensitive and specific test for Indian patients in whom the mean anti‐Dsg titres are raised.
The relationship between DNA methylation and telomere length in dyskeratosis congenita
Authors: Gadalla Shahinaz M. , Katki Hormuzd A. , Shebl Fatma M. , Giri Neelam , Alter Blanche P. , Savage Sharon A.
Published: October 2011

The regulation of telomere length (TL) is a complex process, requiring the telomerase enzyme complex and numerous regulatory proteins. Epigenetic regulation may also be important in telomere maintenance. Specifically, methylation at subtelomeres is associated with changes in TL in vitro and in mouse models. Dyskeratosis congenita (DC) is an inherited bone marrow failure syndrome characterized by exceedingly short telomeres and mutations in telomere biology genes. To understand the interaction between methylation and TL in humans, we measured LINE‐1, pericentromeric (NBL2), and subtelomeric (D4Z4) methylation in peripheral blood DNA derived from 40 patients with DC and 51 mutation‐negative relatives. Pearson’s correlation coefficient and linear regression models were used to evaluate the relationship between age‐standardized lymphocyte TL measured by flow FISH and % DNA methylation. No differences in % subtelomeric, LINE‐1, or pericentromeric methylation between patients with DC and relatives were noted except for an increase in % subtelomeric methylation in DC patients with a telomerase‐complex mutation (TERC, TERT, DKC1, or TCAB1) (63.0% in DC vs. 61.8% in relatives, P = 0.03). Positive correlations between TL and DNA methylation at LINE‐1 (r = 0.39, P = 0.01) and subtelomeric (r = 0.32, P = 0.05) sites were present in patients with DC. The positive correlation between TL and % LINE‐1 methylation was restricted to TINF2 mutations. In contrast, statistically nonsignificant inverse correlations between TL and % LINE‐1 (r = −0.17), subtelomeric (r = −0.20) were present in unaffected relatives. This study suggests an interaction between TL and both subtelomeric and LINE‐1 methylation, which may be altered based on mutation status of telomere biology genes.
Vote Buying and Social Desirability Bias: Experimental Evidence from Nicaragua
Authors: Gonzalez‐Ocantos Ezequiel , de Jonge Chad Kiewiet , Meléndez Carlos , Osorio Javier , Nickerson David W.
Published: October 2011

Qualitative studies of vote buying find the practice to be common in many Latin American countries, but quantitative studies using surveys find little evidence of vote buying. Social desirability bias can account for this discrepancy. We employ a survey‐based list experiment to minimize the problem. After the 2008 Nicaraguan municipal elections, we asked about vote‐buying behavior by campaigns using a list experiment and the questions traditionally used by studies of vote buying on a nationally representative survey. Our list experiment estimated that 24% of registered voters in Nicaragua were offered a gift or service in exchange for votes, whereas only 2% reported the behavior when asked directly. This detected social desirability bias is nonrandom and analysis based on traditional obtrusive measures of vote buying is unreliable. We also provide systematic evidence that shows the importance of monitoring strategies by parties in determining who is targeted for vote buying.
Third‐year Medical Student Rotations in Emergency Medicine: A Survey of Current Practices
Authors: Mulcare Mary R. , Suh Edward Hyun , Tews Matthew , Swan‐Sein Aubrie , Pandit Kiran
Published: October 2011

Academic Emergency Medicine 2011; 18:S41–S47 © 2011 by the Society for Academic Emergency Medicine

Objectives:  Exposure to emergency medicine (EM) is a crucial aspect of medical student education, yet one that is historically absent from third‐year medical student training. There are limited data describing the existing third‐year rotations. The goal of this study is to identify the content and structure of current EM rotations specific to third‐year students.

Methods:  An institutional review board–approved survey of clerkship characteristics was designed by consensus opinion of clerkship directors (CDs). The survey was distributed to 32 CDs at institutions with known EM clerkships involving third‐year students.

Results:  Twenty‐three (72%) CDs responded to the survey. Sixty‐five percent have rotations designed specifically for third‐year students, of which 33% are required clerkships. Twenty‐seven percent of rotations have prerequisite rotations; 37% of rotations include shifts in the pediatric ED. Clinical time averages four 8‐hour shifts per week for 4 weeks; all rotations include weekly didactic time specific to third‐year students. A wide variety of textbooks are used; some programs employ simulation labs. Two‐thirds of the rotations have a required write‐up or presentation; 53% include a final exam. Student evaluations are written and verbal. Most rotations receive more support from the EM departments than from the medical schools for physical space, administrative needs, and faculty time. Among those surveyed, students from institutions requiring a third‐year EM rotation have a higher rate of application to EM residencies.

Conclusions:  There is variability in the content and structure of existing third‐year EM rotations, as well as in financial and administrative needs and support. These data can help to inform CDs and departments that are starting or modifying EM third‐year rotations, as well as contribute to the development of curricula for such rotations.
Biosecurity-Based Interventions and Strategies To Reduce Campylobacter spp. on Poultry Farms
Authors: Newell D. G. , Elvers K. T. , Dopfer D. , Hansson I. , Jones P. , James S. , Gittins J. , Stern N. J. , Davies R. , Connerton I. , Pearson D. , Salvat G. , Allen V. M.
Published: October 2011

The prevention and control of
Campylobacter
colonization of poultry flocks are important public health strategies for the control of human campylobacteriosis. A critical review of the literature on interventions to control
Campylobacter
in poultry on farms was undertaken using a systematic approach. Although the focus of the review was on aspects appropriate to the United Kingdom poultry industry, the research reviewed was gathered from worldwide literature. Multiple electronic databases were employed to search the literature, in any language, from 1980 to September 2008. A primary set of 4,316 references was identified and scanned, using specific agreed-upon criteria, to select relevant references related to biosecurity-based interventions. The final library comprised 173 references. Identification of the sources of
Campylobacter
in poultry flocks was required to inform the development of targeted interventions to disrupt transmission routes. The approach used generally involved risk factor-based surveys related to culture-positive or -negative flocks, usually combined with a structured questionnaire. In addition, some studies, either in combination or independently, undertook intervention trials. Many of these studies were compromised by poor design, sampling, and statistical analysis. The evidence for each potential source and route of transmission on the poultry farm was reviewed critically, and the options for intervention were considered. The review concluded that, in most instances, biosecurity on conventional broiler farms can be enhanced and this should contribute to the reduction of flock colonization. However, complementary, non-biosecurity-based approaches will also be required in the future to maximize the reduction of
Campylobacter
-positive flocks at the farm level.
Application of a Bacteriophage Lysin To Disrupt Biofilms Formed by the Animal Pathogen Streptococcus suis
Authors: Meng Xiangpeng , Shi Yibo , Ji Wenhui , Meng Xueling , Zhang Jing , Wang Hengan , Lu Chengping , Sun Jianhe , Yan Yaxian
Published: October 2011

Bacterial biofilms are crucial to the pathogenesis of many important infections and are difficult to eradicate.Streptococcus suisis an important pathogen of pigs, and here the biofilm-forming ability of 32 strains of this species was determined. Significant biofilms were completely formed by 10 of the strains after 60 h of incubation, with exopolysaccharide production in the biofilm significantly higher than that in the corresponding planktonic cultures.S. suisstrain SS2-4 formed a dense biofilm, as revealed by scanning electron microscopy, and in this state exhibited increased resistance to a number of antibiotics (ampicillin, amoxicillin, ciprofloxacin, kanamycin, and rifampin) compared to that of planktonic cultures. A bacteriophage lysin, designated LySMP, was used to attack biofilms alone and in combination with antibiotics and bacteriophage. The results demonstrated that the biofilms formed byS. suis, especially strains SS2-4 and SS2-H, could be dispersed by LySMP and with >80% removal compared to a biofilm reduction by treatment with either antibiotics or bacteriophage alone of less than 20%; in addition to disruption of the biofilm structure, theS. suiscells themselves were inactivated by LySMP. The efficacy of LySMP was not dose dependent, and in combination with antibiotics, it acted synergistically to maximize dispersal of theS. suisbiofilm and inactivate the released cells. These data suggest that bacteriophage lysin could form part of an effective strategy to treatS. suisinfections and represents a new class of antibiofilm agents.
Method Enabling Gene Expression Studies of Pathogens in a Complex Food Matrix
Authors: Kjeldgaard Jette , Henriksen Sidsel , Cohn Marianne Thorup , Aabo Sï¿½ren , Ingmer Hanne
Published: October 2011

We describe a simple method for stabilizing and extracting high-quality prokaryotic RNA from meat. Heat and salt stress of
Escherichia coli
and
Salmonella
spp. in minced meat reproducibly induced
dnaK
and
otsB
expression, respectively, as observed by quantitative reverse transcription-PCR (>5-fold relative changes). Thus, the method is applicable in studies of bacterial gene expression in a meat matrix.
Production of a Particulate Hepatitis C Vaccine Candidate by an Engineered Lactococcus lactis Strain
Authors: Parlane Natalie A. , Grage Katrin , Lee Jason W. , Buddle Bryce M. , Denis Michel , Rehm Bernd H. A.
Published: October 2011

Vaccine delivery systems based on display of antigens on bioengineered bacterial polyester inclusions can stimulate cellular immune responses. The food-grade Gram-positive bacteriumLactococcus lactiswas engineered to produce spherical polyhydroxybutyrate (PHB) inclusions which abundantly displayed the hepatitis C virus core (HCc) antigen. In mice, the immune response induced by this antigen delivery system was compared to that induced by vaccination with HCc antigen displayed on PHB beads produced inEscherichia coli, to PHB beads without antigen produced inL. lactisorE. coli, or directly to the recombinant HCc protein. Vaccination site lesions were minimal in all mice vaccinated with HCc PHB beads or recombinant protein, all mixed in the oil-in-water adjuvant Emulsigen, while vaccination with the recombinant protein in complete Freund's adjuvant produced a marked inflammatory reaction at the vaccination site. Vaccination with the PHB beads produced inL. lactisand displaying HCc antigen produced antigen-specific cellular immune responses with significant release of gamma interferon (IFN-γ) and interleukin-17A (IL-17A) from splenocyte cultures and no significant antigen-specific serum antibody, while the PHB beads displaying HCc but produced inE. colireleased IFN-γ and IL-17A as well as the proinflammatory cytokines tumor necrosis factor alpha (TNF-α) and IL-6 and low levels of IgG2c antibody. In contrast, recombinant HCc antigen in Emulsigen produced a diverse cytokine response and a strong IgG1 antibody response. Overall it was shown thatL. lactiscan be used to produce immunogenic PHB beads displaying viral antigens, making the beads suitable for vaccination against viral infections.
Robust Utilization of Phospholipase-Generated Metabolites, Glycerophosphodiesters, by Candida albicans: Role of the CaGit1 Permease
Authors: Bishop Andrew C. , Sun Tao , Johnson Mitchell E. , Bruno Vincent M. , Patton-Vogt Jana
Published: October 2011

Glycerophosphodiesters are the products of phospholipase-mediated deacylation of phospholipids. In
Saccharomyces cerevisiae
, a single gene,
GIT1
, encodes a permease responsible for importing glycerophosphodiesters, such as glycerophosphoinositol and glycerophosphocholine, into the cell. In contrast, the
Candida albicans
genome contains four open reading frames (ORFs) with a high degree of similarity to
S. cerevisiae
GIT1
(
ScGIT1
) Here, we report that
C. albicans
utilizes glycerophosphoinositol (GroPIns) and glycerophosphocholine (GroPCho) as sources of phosphate at both mildly acidic and physiological pHs. Insertional mutagenesis of
C. albicans
GIT1
(
CaGIT1
) (orf19.34), the ORF most similar to
ScGit1
, abolished the ability of cells to use GroPIns as a phosphate source at acidic pH and to transport [
3
H]GroPIns at acidic and physiological pHs, while reintegration of a
GIT1
allele into the genome restored those functions. Several lines of evidence, including the detection of internal [
3
H]GroPIns, indicated that GroPIns is transported intact through CaGit1. GroPIns transport was shown to conform to Michaelis-Menten kinetics, with an apparent

K
m

of 28 ± 6 μM. Notably, uptake of label from [
3
H]GroPCho was found to be roughly 50-fold greater than uptake of label from [
3
H]GroPIns and roughly 500-fold greater than the equivalent activity in
S. cerevisiae.
Insertional mutagenesis of
CaGIT1
had no effect on the utilization of GroPCho as a phosphate source or on the uptake of label from [
3
H]GroPCho. Growth under low-phosphate conditions was shown to increase label uptake from both [
3
H]GroPIns and [
3
H]GroPCho. Screening of a transcription factor deletion set identified
CaPHO4
as required for the utilization of GroPIns, but not GroPCho, as a phosphate source.
Maximum likelihood estimation in nonlinear structured fisheries models using survey and catch-at-age data
Authors: Brinch Christian N. , Eikeset Anne Maria , Stenseth Nils Chr.
Published: October 2011

Age-structured population dynamics models play an important role in fisheries assessments. Such models have traditionally been estimated using crude likelihood approximations or more recently using Bayesian techniques. We contribute to this literature with three main messages. Firstly, we demonstrate how to estimate such models efficiently by simulated maximum likelihood using Laplace importance samplers for the likelihood function. Secondly, we demonstrate how simulated maximum likelihood estimates may be validated using different importance samplers known to approach the exact likelihood function in different regions of the parameter space. Thirdly, we show that our method works in practice by Monte Carlo simulations using parameter values as estimated from data on the Northeast Arctic cod ( Gadus morhua ) stock. The simulations suggest that we are able to recover the unknown true maximum likelihood estimates using moderate importance sample sizes and show that we are able to adequately recover the true parameter values.
Wastewater release and its impacts on Canadian waters
Authors: Holeton Claire , Chambers Patricia A. , Grace Laura
Published: October 2011

Discharge of sewage to the environment in the form of treated or untreated wastewater can have serious impacts on human health and quality of life and on ecosystem condition. Since a previous review in 1997, upgrades to wastewater treatment facilities, along with improved source control, have produced successes in reducing loadings of certain pollutants (e.g., mercury, polychlorinated biphenyls) to Canadian waters. However, nationally, loads of phosphorus discharged from wastewater treatment facilities have not changed in recent years (2003–2008), and releases of nitrogen have increased slightly. In some locations, wastewater discharges are contributors to bacterial contamination, toxicity from heavy metals and ammonia, and eutrophication, all of which continue to threaten public and environmental health. An increasing number of studies are also demonstrating developmental, reproductive, and behavioural changes in fish and other aquatic organisms from exposure to pharmaceuticals, personal-care products, or other pollutants in domestic wastewater, even after treatment. Minimizing wastewater discharge and mitigating its effects on the environment and human health will be a challenge. It is critical that gains achieved by improved wastewater treatment and other control measures not be reversed by relaxation of efforts or by failure to keep pace with population growth.
Carbohydrate–protein ingestion improves subsequent running capacity towards the end of a football-specific intermittent exercise
Authors: Alghannam Abdullah F.
Published: October 2011

The majority of football players succumb to fatigue towards the end of the game. This study was designed to examine the influence of protein coingestion with carbohydrate (CHO) vs. an isocaloric CHO supplement on subsequent running capacity towards the end of a simulated football match. Six male amateur football players participated in 3 trials applied in a randomized cross-over experimental design. A laboratory-based, football-specific intermittent exercise was allocated for 75 min interspersed with a 15-min recovery, immediately followed by run time to fatigue (RTF) at 80% peak oxygen consumption. In each trial, prior to exercise and during half-time, participants randomly ingested a placebo (PLC), 6.9% CHO, or 4.8% CHO plus 2.1% protein (CHO-P) supplements matched for color and taste. CHO-P resulted in longer RTF (23.02 ± 5.27 min) than did CHO (16.49 ± 3.25 min) and PLC (11.00 ± 2.80 min) (p < 0.05). Blood glucose was higher in CHO-P at the point of fatigue (4.68 ± 0.64) compared with CHO and PLC (3.92 ± 0.29 and 3.66 ± 0.36, respectively; p < 0.05). Ratings of perceived exertion were lower in the CHO-P subjects at the onset of exercise and towards the end of intermittent exercise when compared with the PLC and CHO subjects (p < 0.05). When protein was added to a CHO supplement, subsequent running capacity following limited recovery from intermittent exercise was enhanced. This improvement suggests that protein coingestion may exert an ergogenic benefit upon endurance capacity during intermittent activity.
Endothelium-derived NO, but not cyclic GMP, is required for hypoxic augmentation in isolated porcine coronary arteries
Authors: Chan Calvin K. Y. , Mak Judith , Gao Yuansheung , Man Ricky Y. K. , Vanhoutte Paul M.
Published: October 2011

The present study investigated the mechanism underlying the transient potentiation of vasoconstriction by hypoxia in isolated porcine coronary arteries. Isometric tension was measured in rings with or without endothelium. Hypoxia (Po2 <30 mmHg) caused a transient further increase in tension (hypoxic augmentation) in contracted (with U46619) preparations. The hypoxic response was endothelium dependent and abolished by inhibitors of nitric oxide synthase [ Nω-nitro-l-arginine methyl ester (l-NAME)] or soluble guanylyl cyclase (ODQ and NS2028). The addition of DETA NONOate (nitric oxide donor) in the presence of l-NAME restored the hypoxic augmentation, suggesting the involvement of the nitric oxide pathway. However, the same was not observed after incubation with 8-bromo-cyclic GMP, atrial natriuretic peptide, or isoproterenol. Assay of the cyclic GMP content showed no change upon exposure to hypoxia in preparations with and without endothelium. Incubation with protein kinase G and protein kinase A inhibitors did not inhibit the hypoxic augmentation. Thus the hypoxic augmentation is dependent on nitric oxide and soluble guanylyl cyclase but independent of cyclic GMP. The hypoxic augmentation persisted in calcium-free buffer and in the presence of nifedipine, ruling out a role for extracellular calcium influx. Hypoxia did not alter the intracellular calcium concentration, as measured by confocal fluorescence microscopy. This observation and the findings that hypoxic augmentation is enhanced by thapsigargin (sarco/endoplasmic reticulum calcium ATPase inhibitor) and inhibited by HA1077 or Y27632 (Rho kinase inhibitors) demonstrate the involvement of calcium sensitization in the phenomenon.
Relationship between Ca2+sparklets and sarcoplasmic reticulum Ca2+load and release in rat cerebral arterial smooth muscle
Authors: Takeda Yukari , Nystoriak Matthew A. , Nieves-Cintrón Madeline , Santana Luis F. , Navedo Manuel F.
Published: October 2011

Ca+sparklets are subcellular Ca2+signals produced by the opening of sarcolemmal L-type Ca2+channels. Ca2+sparklet activity varies within the sarcolemma of arterial myocytes. In this study, we examined the relationship between Ca2+sparklet activity and sarcoplasmic reticulum (SR) Ca2+accumulation and release in cerebral arterial myocytes. Our data indicate that the SR is a vast organelle with multiple regions near the sarcolemma of these cells. Ca2+sparklet sites were located at or <0.2 μm from SR-sarcolemmal junctions. We found that while Ca2+sparklets increase the rate of SR Ca2+refilling in arterial myocytes, their activity did not induce regional variations in SR Ca2+content or Ca2+spark activity. In arterial myocytes, L-type Ca2+channel activity was independent of SR Ca2+load. This ruled out a potential feedback mechanism whereby SR Ca2+load regulates the activity of these channels. Together, our data suggest a model in which Ca2+sparklets contribute Ca2+influx into a cytosolic Ca2+pool from which sarco(endo)plasmic reticulum Ca2+-ATPase pumps Ca2+into the SR, indirectly regulating SR function.
Functional consequences of stably expressing a mutant calsequestrin (CASQ2D307H) in the CASQ2 null background
Authors: Kalyanasundaram Anuradha , Viatchenko-Karpinski Serge , Belevych Andriy E. , Lacombe Veronique A. , Hwang Hyun Seok , Knollmann Björn C. , Gyorke Sandor , Periasamy Muthu
Published: October 2011

The role of calsequestrin (CASQ2) in cardiac sarcoplasmic reticulum (SR) calcium (Ca2+) transport has gained significant attention since point mutations in CASQ2 were reported to cause ventricular arrhythmia. In the present study, we have critically evaluated the functional consequences of expressing the CASQ2D307Hmutant protein in the CASQ2 null mouse. We recently reported that the mutant CASQ2D307Hprotein can be stably expressed in CASQ2 null hearts, and it targets appropriately to the junctional SR (Kalyanasundaram A, Bal NC, Franzini-Armstrong C, Knollmann BC, Periasamy M. J Biol Chem 285: 3076–3083, 2010). In this study, we found that introduction of CASQ2D307Hprotein in the CASQ2 null background partially restored triadin 1 levels, which were decreased in the CASQ2 null mice. Despite twofold expression (relative to wild-type CASQ2), the mutant protein failed to increase SR Ca2+load. We also found that the Ca2+transient decays slower in the CASQ2 null and CASQ2D307Hcells. CASQ2D307Hmyocytes, when rhythmically paced and challenged with isoproterenol, exhibit spontaneous Ca2+waves similar to CASQ2 null myocytes; however, the stability of Ca2+cycling was increased in the CASQ2D307Hmyocytes. In the presence of isoproterenol, Ca2+-transient amplitude in CASQ2D307Hmyocytes was significantly decreased, possibly indicating an inherent defect in Ca2+buffering capacity and release from the mutant CASQ2 at high Ca2+concentrations. We also observed polymorphic ventricular tachycardia in the CASQ2D307Hmice, although lesser than in the CASQ2 null mice. These data suggest that CASQ2D307Hpoint mutation may affect Ca2+buffering capacity and Ca2+release. We propose that poor interaction between CASQ2D307Hand triadin 1 could affect ryanodine receptor 2 stability, thereby increasing susceptibility to delayed afterdepolarizations and triggered arrhythmic activity.
Noninvasive reconstruction of the three-dimensional ventricular activation sequence during pacing and ventricular tachycardia in the canine heart
Authors: Han Chengzong , Pogwizd Steven M. , Killingsworth Cheryl R. , He Bin
Published: October 2011

Single-beat imaging of myocardial activation promises to aid in both cardiovascular research and clinical medicine. In the present study we validate a three-dimensional (3D) cardiac electrical imaging (3DCEI) technique with the aid of simultaneous 3D intracardiac mapping to assess its capability to localize endocardial and epicardial initiation sites and image global activation sequences during pacing and ventricular tachycardia (VT) in the canine heart. Body surface potentials were measured simultaneously with bipolar electrical recordings in a closed-chest condition in healthy canines. Computed tomography images were obtained after the mapping study to construct realistic geometry models. Data analysis was performed on paced rhythms and VTs induced by norepinephrine (NE). The noninvasively reconstructed activation sequence was in good agreement with the simultaneous measurements from 3D cardiac mapping with a correlation coefficient of 0.74 ± 0.06, a relative error of 0.29 ± 0.05, and a root mean square error of 9 ± 3 ms averaged over 460 paced beats and 96 ectopic beats including premature ventricular complexes, couplets, and nonsustained monomorphic VTs and polymorphic VTs. Endocardial and epicardial origins of paced beats were successfully predicted in 72% and 86% of cases, respectively, during left ventricular pacing. The NE-induced ectopic beats initiated in the subendocardium by a focal mechanism. Sites of initial activation were estimated to be ∼7 mm from the measured initiation sites for both the paced beats and ectopic beats. For the polymorphic VTs, beat-to-beat dynamic shifts of initiation site and activation pattern were characterized by the reconstruction. The present results suggest that 3DCEI can noninvasively image the 3D activation sequence and localize the origin of activation of paced beats and NE-induced VTs in the canine heart with good accuracy. This 3DCEI technique offers the potential to aid interventional therapeutic procedures for treating ventricular arrhythmias arising from epicardial or endocardial sites and to noninvasively assess the mechanisms of these arrhythmias.
Central and peripheral hemodynamic responses to passive limb movement: the role of arousal
Authors: Venturelli Massimo , Amann M. , McDaniel J. , Trinity J. D. , Fjeldstad A. S. , Richardson R. S.
Published: October 2011

The exact role of arousal in central and peripheral hemodynamic responses to passive limb movement in humans is unclear but has been proposed as a potential contributor. Thus, we used a human model with no lower limb afferent feedback to determine the role of arousal on the hemodynamic response to passive leg movement. In nine people with a spinal cord injury, we compared central and peripheral hemodynamic and ventilatory responses to one-leg passive knee extension with and without visual feedback (M+VF and M-VF, respectively) as well as in a third trial with no movement or visual feedback but the perception of movement (F). Ventilation (V̇e), heart rate, stroke volume, cardiac output, mean arterial pressure, and leg blood flow (LBF) were evaluated during the three protocols. V̇e increased rapidly from baseline in M+VF (55 ± 11%), M-VF (63 ± 13%), and F (48 ± 12%) trials. Central hemodynamics (heart rate, stroke volume, cardiac output, and mean arterial pressure) were unchanged in all trials. LBF increased from baseline by 126 ± 18 ml/min in the M+VF protocol and 109 ± 23 ml/min in the M-VF protocol but was unchanged in the F protocol. Therefore, with the use of model that is devoid of afferent feedback from the legs, the results of this study reveal that, although arousal is invoked by passive movement or the thought of passive movement, as evidenced by the increase in V̇e, there is no central or peripheral hemodynamic impact of this increased neural activity. Additionally, this study revealed that a central hemodynamic response is not an obligatory component of movement-induced LBF.
HSP25 can modulate myofibrillar desmin cytoskeleton following the phosphorylation at Ser15 in rat soleus muscle
Authors: Kawano Fuminori , Fujita Ryo , Nakai Naoya , Terada Masahiro , Ohira Takashi , Ohira Yoshinobu
Published: October 2011

The main purpose of the present study was to investigate the role(s) of 25-kDa heat shock protein (HSP25) in the regulation and integration of myofibrillar Z-disc structure during down- or upregulation of the size in rat soleus muscle fibers. Hindlimb unloading by tail suspension was performed in adult rats for 7 days, and reloading was allowed for 5 days after the termination of suspension. Interaction of HSP25 and Z-disc proteins, phosphorylation status, distribution, and complex formation of HSP25 were investigated. Non- and single-phosphorylated HSP25s were generally expressed in the cytoplasmic fraction of normal muscle. The level of total HSP25, as well as the phosphorylation ratio, did not change significantly in response to atrophy. Increased expressions of HSP25, phosphorylated at serine 15 (p-Ser15) and dual-phosphorylated form, were noted, when atrophied muscles were reloaded. Myofibrillar HSP25 was also noted in reloaded muscle. Histochemical analysis further indicated the localization of p-Ser15 in the regions with disorganization of Z-disc structure in reloaded muscle fibers. HSP25 formed a large molecular complex in the cytoplasmic fraction of normal muscle, whereas dissociation of free HSP25 with Ser15 phosphorylation was noted in reloaded muscle. The interaction of p-Ser15 with desmin and actinin was detected in Z-discs by proximity ligation assay. Strong interaction between p-Ser15 and desmin, but not actinin, was noted in the disorganized areas. These results indicated that HSP25 contributed to the desmin cytoskeletal organization following the phosphorylation at Ser15 during reloading and regrowing of soleus muscle.
Surface morphology and electrical property evolution of super-thin Pt film on 6H-SiC substrate during annealing
Authors: Yang Jingjing , Yuan Wenxia , Zeng Xiaopeng
Published: October 2011

We reported the surface morphology and electrical property of super-thin Pt films, ∼2 nm thick, deposited on 6H-SiC (0001) substrates and subsequently annealed from 400 to 1000 °C. The surfaces of the films were found to have a feature of islands growth, and the sizes of the islands increased with increasing annealing temperature. Free carbon, produced by selective reactions between Pt and SiC, diffused toward the top surface across the product layers due to low solubility and composition gradient of carbon throughout the reaction zone. A dramatic change of electrical conductivity of the films was observed. A mechanism analysis reveals that the origin came from the contribution of aggregation of islands on the surface and formation of Pt silicides and a thin layer of crystalline graphite.
Caenorhabditis elegans
Muscle
Authors: Benian Guy M. , Epstein Henry F.
Published: October 2011

The nematode
Caenorhabditis elegans
has become established as a major experimental organism with applications to many biomedical research areas. The body wall muscle cells are a useful model for the study of human cardiomyocytes and their homologous structures and proteins. The ability to readily identify mutations affecting these proteins and structures in
C elegans
and to be able to rigorously characterize their genotypes and phenotypes at the cellular and molecular levels permits mechanistic studies of the responsible interactions relevant to the inherited human cardiomyopathies. Future work in
C elegans
muscle holds great promise in uncovering new mechanisms in the pathogenesis of these cardiac disorders.
Inhibition of PKCα/β With Ruboxistaurin Antagonizes Heart Failure in Pigs After Myocardial Infarction Injury
Authors: Ladage Dennis , Tilemann Lisa , Ishikawa Kiyotake , Correll Robert N. , Kawase Yoshiaki , Houser Steven R. , Molkentin Jeffery D. , Hajjar Roger J.
Published: October 2011

Rationale:

Protein kinase Cα (PKCα) activity and protein level are induced during cardiac disease where it controls myocardial contractility and propensity to heart failure in mice and rats. For example, mice lacking the gene for
PKC
α have enhanced cardiac contractility and reduced susceptibility to heart failure after long-term pressure overload or after myocardial infarction injury. Pharmacological inhibition of PKCα/β with Ro-32-0432, Ro-31-8220 or ruboxistaurin (LY333531) similarly enhances cardiac function and antagonizes heart failure in multiple models of disease in both mice and rats.

Objective:

Large and small mammals differ in several key indexes of heart function and biochemistry, lending uncertainty as to how PKCα/β inhibition might affect or protect a large animal model of heart failure.

Methods and Results:

We demonstrate that ruboxistaurin administration to a pig model of myocardial infarction–induced heart failure was protective. Twenty-kilogram pigs underwent left anterior descending artery occlusion resulting in myocardial infarctions and were then divided into vehicle or ruboxistaurin feed groups, after which they were monitored monthly for the next 3 months. Ruboxistaurin administered pigs showed significantly better recovery of myocardial contractility 3 months after infarction injury, greater ejection fraction, and greater cardiac output compared with vehicle-treated pigs.

Conclusions:

These results provide additional evidence in a large animal model of disease that PKCα/β inhibition (with ruboxistaurin) represents a tenable and novel therapeutic approach for treating human heart failure.
Improved Prediction of Poor Outcome After Thrombolysis Using Conservative Definitions of Symptomatic Hemorrhage
Authors: Gumbinger Christoph , Gruschka Philipp , Böttinger Markus , Heerlein Kristin , Barrows Robin , Hacke Werner , Ringleb Peter
Published: October 2011

Background and Purpose—

Direct comparison of symptomatic intracerebral hemorrhage (sICH) rates among different thrombolysis studies is complicated by the variability of definitions of sICH. The prediction of outcome still remains unclear.

Methods—

Baseline data and clinical courses of patients treated with thrombolytic therapy were collected in a prospective database. The 3-month outcome was evaluated using the modified Rankin Scale. Results of 24-hour follow-up imaging were reevaluated by at least 2 independent raters. Four common definitions of sICH (National Institute of Neurological Disorders and Stroke [NINDS], European Cooperative Acute Stroke Study [ECASS] 2, Safe Implementation of Thrombolysis in Stroke [SITS], ECASS 3) were applied. Kappa interrater statistics were calculated. Our objective was to find the sICH definition with the highest predictive value for mortality, poor (modified Rankin Scale 5 or 6) and unfavorable (modified Rankin Scale ≥3) clinical outcome after 90 days.

Results—

The data of 314 patients were analyzed. The NINDS definition revealed the highest sICH rate (7.7%); the lowest rate was found for the ECASS 3 definition (3.2%) of sICH. The highest interrater agreement was found for the ECASS 2 definition (κ 0.85) and the lowest for the NINDS definition (κ 0.57). Patients with sICH according to the SITS definition had the highest risk for death (OR, 14.4) and poor outcome (OR, 26.6).

Conclusions—

None of the different definitions contains an optimal combination of prediction of mortality and outcome and a high interrater agreement rate. For the clinical evaluation of mortality, we recommend using the SITS definition; for studies needing a high interrater agreement rate, we recommend using the ECASS 2 definition. Due to the lack of 1 single optimal definition, future thrombolytic trials should preferably use different definitions.