bluuebunny/crossref_metadata_2025 huggingface dataset:
Post‐Variscan exhumation of the Central Anti‐Atlas (Morocco) constrained by zircon and apatite fission‐track thermochronology
Authors: Oukassou Mostafa , Saddiqi Omar , Barbarand Jocelyn , Sebti Samira , Baidder Lahssen , Michard André
Published: November 2012

The origin of the Anti‐Atlas relief is one of the currently debated issues of Moroccan geology. To constrain the post‐Variscan evolution of the Central Anti‐Atlas, we collected nine samples from the Precambrian basement of the Bou Azzer‐El Graara inlier for zircon and apatite fission‐track thermochronology. Zircon ages cluster between 340 ± 20 and 306 ± 20 Ma, whereas apatite ages range from 171 ± 7 Ma to 133 ± 5 Ma. Zircon ages reflect the thermal effect of the Variscan orogeny (tectonic thickening of the ca. 7 km‐thick Paleozoic series), likely enhanced by fluid advection. Apatite ages record a complex Mesozoic–Cenozoic exhumation history. Track length modelling yields evidence that, (i) the Precambrian basement was still buried at ca. 5 km depth by Permian times, (ii) the Central Anti‐Atlas was subjected to (erosional) exhumation during the Triassic‐Early Cretaceous, then buried beneath ca. 1.5 km‐thick Cretaceous‐Paleogene deposits, (iii) final exhumation took place during the Neogene, contemporaneously with that of the High Atlas.
Schirmer tear test typeIreadings and intraocular pressure values assessed by applanation tonometry (Tonopen®XL) in normal eyes of fourEuropean species of birds of prey
Authors: Barsotti Giovanni , Briganti Angela , Spratte Johanna R. , Ceccherelli Renato , Breghi Gloria
Published: November 2012

Objective

To determine normal values forSchirmer tear testIand intraocular pressure in fourEuropean species of birds of prey.

Animals studied

Twenty birds from each of the following species:EurasianTawny owl (Strix aluco),Little owl (Athene noctua), Common buzzard (Buteo buteo), andEuropean kestrel (Falco tinnunculus).

Procedures

Both eyes of all birds (80 eyes) underwent a complete ophthalmic examination, which included aSchirmer tear test typeI(STT‐I) performed with commercially available strips and the assessment of the intraocular pressure (IOP) by applanation tonometry, employing theTonopen‐XL®device. The animals, which had been taken to a rescue center, were examined for ocular lesions prior to their eventual release into the wild.STT‐Ireadings andIOPvalues were expressed as means ± standard deviation.

Results

Schirmer tear test typeIreadings were as follows:EurasianTawny owls: 3.12 ± 1.92 mm/min;Little owls: 3.5 ± 1.96 mm/min;Common buzzards: 12.47 ± 2.66 mm/min;European kestrels: 6.20 ± 3.67 mm/min.IOPvalues were as follows:EurasianTawny owls: 11.21 ± 3.12 mmHg;Little owls: 9.83 ± 3.41 mmHg;Common buzzards: 17.2 ± 3.53 mmHg;European kestrels: 8.53 ± 1.59 mmHg.

Conclusions

The results of this study give representative values forSTT‐IandIOPin four of the most common species of birds of prey in Europe.
Absolute Lymphocyte Count Predicts the Response to New Influenza Virus H1N1 Vaccination in Pediatric Cancer Patients
Authors: Mavinkurve-Groothuis Annelies M. C. , van der Flier Michiel , Stelma Foekje , van Leer-Buter Coretta , Preijers Frank W. , Hoogerbrugge Peter M.
Published: November 2012

We measured the vaccination response to the new H1N1 virus in relation to the lymphocyte count prior to vaccination in pediatric cancer patients. The absolute lymphocyte count above the lower normal limits (LNL) for age prior to vaccination predicts the response to influenza vaccination in pediatric cancer patients treated with chemotherapy.
Activity of the Calcium Channel Pore Cch1 Is Dependent on a Modulatory Region of the Subunit Mid1 in Cryptococcus neoformans
Authors: Hong Min-Pyo , Vu Kiem , Bautos Jennifer M. , Tham Rick , Jamklang Mantana , Uhrig John P. , Gelli Angie
Published: November 2012

Calcium (Ca
2+
)-mediated signaling events in fungal pathogens such as
Cryptococcus neoformans
are central to physiological processes, including those that mediate stress responses and promote virulence. The Cch1-Mid1 channel (CMC) represents the only high-affinity Ca
2+
channel in the plasma membrane of fungal cells; consequently, cryptococci cannot survive in low-Ca
2+
environments in the absence of CMC. Previous electrophysiological characterization revealed that Cch1, the predicted channel pore, and Mid1, a binding partner of Cch1, function as a store-operated Ca
2+
-selective channel gated by depletion of endoplasmic reticulum (ER) Ca
2+
stores. Cryptococci lacking CMC did not survive ER stress, indicating its critical role in restoring Ca
2+
homeostasis. Despite the requirement for Mid1 in promoting Ca
2+
influx via Cch1, identification of the role of Mid1 remains elusive. Here we show that the C-terminal tail of Mid1 is a modulatory region that impinges on Cch1 channel activity directly and mediates the trafficking of Mid1 to the plasma membrane. This region consists of the last 24 residues of Mid1, and the functional expression of Mid1 in a human embryonic cell line (HEK293) and in
C. neoformans
is dependent on this domain. Substitutions of arginine (R619A) or cysteine (C621A) in the modulatory region failed to target Mid1 to the plasma membrane and prevented CMC activity. Interestingly, loss of a predicted protein kinase C (PKC)-phosphorylated serine residue (S605A) had no effect on Mid1 trafficking but did alter the kinetics of Cch1 channel activity. Thus, establishment of Ca
2+
homeostasis in
C. neoformans
is dependent on a modulatory domain of Mid1.
The Structure of the CS1 Pilus of Enterotoxigenic Escherichia coli Reveals Structural Polymorphism
Authors: Galkin Vitold E. , Kolappan Subramaniapillai , Ng Dixon , Zong ZuSheng , Li Juliana , Yu Xiong , Egelman Edward H. , Craig Lisa
Published: November 2012

Enterotoxigenic
Escherichia coli
(ETEC) is a bacterial pathogen that causes diarrhea in children and travelers in developing countries. ETEC adheres to host epithelial cells in the small intestine via a variety of different pili. The CS1 pilus is a prototype for a family of related pili, including the CFA/I pili, present on ETEC and other Gram-negative bacterial pathogens. These pili are assembled by an outer membrane usher protein that catalyzes subunit polymerization via donor strand complementation, in which the N terminus of each incoming pilin subunit fits into a hydrophobic groove in the terminal subunit, completing a β-sheet in the Ig fold. Here we determined a crystal structure of the CS1 major pilin subunit, CooA, to a 1.6-Å resolution. CooA is a globular protein with an Ig fold and is similar in structure to the CFA/I major pilin CfaB. We determined three distinct negative-stain electron microscopic reconstructions of the CS1 pilus and generated pseudoatomic-resolution pilus structures using the CooA crystal structure. CS1 pili adopt multiple structural states with differences in subunit orientations and packing. We propose that the structural perturbations are accommodated by flexibility in the N-terminal donor strand of CooA and by plasticity in interactions between exposed flexible loops on adjacent subunits. Our results suggest that CS1 and other pili of this class are extensible filaments that can be stretched in response to mechanical stress encountered during colonization.
Microbiology of Explanted Suture Segments from Infected and Noninfected Surgical Patients
Authors: Edmiston Charles E. , Krepel Candace J. , Marks Richard M. , Rossi Peter J. , Sanger James , Goldblatt Matthew , Graham Mary Beth , Rothenburger Stephen , Collier John , Seabrook Gary R.
Published: November 2012

Sutures under selective host/environmental factors can potentiate postoperative surgical site infection (SSI). The present investigation characterized microbial recovery and biofilm formation from explanted absorbable (AB) and nonabsorbable (NAB) sutures from infected and noninfected sites. AB and NAB sutures were harvested from noninfected (70.9%) and infected (29.1%) sites in 158 patients. At explantation, devices were sonicated and processed for qualitative/quantitative bacteriology; selective sutures were processed for scanning electron microscopy (SEM). Bacteria were recovered from 85 (53.8%) explanted sites; 39 sites were noninfected, and 46 were infected. Suture recovery ranged from 11.1 to 574.6 days postinsertion. A significant difference in mean microbial recovery between noninfected (1.2 isolates) and infected (2.7 isolates) devices (P< 0.05) was noted.Staphylococcus epidermidis,Staphylococcus aureus, coagulase-negative staphylococci (CNS),Peptostreptococcusspp.,Bacteroides fragilis,Escherichia coli,Enterococcusspp.,Pseudomonas aeruginosa, andSerratiaspp. were recovered from infected devices, while commensal skin flora was recovered from noninfected devices. No significant difference in quantitative microbial recovery between infected monofilament and multifilament sutures was noted. Biofilm was present in 100% and 66.6% of infected and noninfected devices, respectively (P< 0.042). We conclude that both monofilament and braided sutures provide a hospitable surface for microbial adherence: (i) a significant difference in microbial recovery from infected and noninfected sutures was noted, (ii) infected sutures harbored a mixed flora, including multidrug-resistant health care-associated pathogens, and (iii) a significant difference in the presence or absence of a biofilm in infected versus noninfected explanted devices was noted. Further studies to document the benefit of focused risk reduction strategies to minimize suture contamination and biofilm formation postimplantation are warranted.
Rapid Detection of Campylobacter Antigen by Enzyme Immunoassay Leads to Increased Positivity Rates
Authors: Giltner Carmen L. , Saeki Sandra , Bobenchik April M. , Humphries Romney M.
Published: November 2012

Campylobacter
antigen detection by enzyme immunoassay (EIA) provides rapid results compared to traditional culture. However, concern exists regarding specificity. Verification studies of an EIA compared to culture revealed a positive predictive value (PPV) of 91%, whereas PPV fell to 42% during routine diagnostic testing. We suggest all positive EIA results be confirmed via culture.
Impact of Mucosal Inflammation on Oral Simian Immunodeficiency Virus Transmission
Authors: Giavedoni Luis D. , Chen Hui-Ling , Hodara Vida L. , Chu Lianrui , Parodi Laura M. , Smith Lisa M. , Sexton Valerie , Cappelli David , Sodora Donald L.
Published: November 2012

Mucosal tissues are the primary route of transmission for most respiratory and sexually transmitted diseases, including human immunodeficiency virus (HIV). There is epidemiological evidence that genital mucosal inflammation leads to enhanced HIV type 1 (HIV-1) transmission. The objective of this study was to assess the influence of periodontal inflammation on oral HIV transmission using a nonhuman primate model of teeth ligature-induced periodontitis. Simian immunodeficiency virus (SIV) was nontraumatically applied to the gingiva after moderate gingivitis was identified through clinical and immunologic analyses (presence of inflammatory cytokines). Overall oral SIV infection rates were similar in the gingivitis-induced and control groups (5 infections following 12 SIV administrations for each), although more macaques were infected with multiple viral variants in the gingivitis group. SIV infection also affected the levels of antiviral and inflammatory cytokines in the gingival crevicular fluid, and a synergistic effect was observed, with alpha interferon and interferon-inducible protein 10 undergoing significant elevations following SIV infection in macaques with gingivitis compared to controls. These increases in antiviral and inflammatory immune modulators in the SIV-infected gingivitis macaques could also be observed in blood plasma, although the effects at both compartments were generally restricted to the acute phase of the infection. In conclusion, while moderate gingivitis was not associated with increased susceptibility to oral SIV infection, it resulted in elevated levels of cytokines in the oral mucosa and plasma of the SIV-infected macaques. These findings suggest a synergy between mucosal inflammation and SIV infection, creating an immune milieu that impacts the early stages of the SIV infection with potential implications for long-term pathogenesis.
The Cellular Autophagy Pathway Modulates Human T-Cell Leukemia Virus Type 1 Replication
Authors: Tang Sai-Wen , Chen Chia-Yen , Klase Zachary , Zane Linda , Jeang Kuan-Teh
Published: November 2012

Autophagy, a general homeostatic process for degradation of cytosolic proteins or organelles, has been reported to modulate the replication of many viruses. The role of autophagy in human T-cell leukemia virus type 1 (HTLV-1) replication has, however, been uncharacterized. Here, we report that HTLV-1 infection increases the accumulation of autophagosomes and that this accumulation increases HTLV-1 production. We found that the HTLV-1 Tax protein increases cellular autophagosome accumulation by acting to block the fusion of autophagosomes to lysosomes, preventing the degradation of the former by the latter. Interestingly, the inhibition of cellular autophagosome-lysosome fusion using bafilomycin A increased the stability of the Tax protein, suggesting that cellular degradation of Tax occurs in part through autophagy. Our current findings indicate that by interrupting the cell's autophagic process, Tax exerts a positive feedback on its own stability.
A Sendai Virus-Derived RNA Agonist of RIG-I as a Virus Vaccine Adjuvant
Authors: Martínez-Gil L. , Goff P. H. , Hai R. , García-Sastre A. , Shaw M. L. , Palese P.
Published: November 2012

The innate immune system is responsible for recognizing invading pathogens and initiating a protective response. In particular, the retinoic acid-inducible gene 1 protein (RIG-I) participates in the recognition of single- and double-stranded RNA viruses. RIG-I activation leads to the production of an appropriate cytokine and chemokine cocktail that stimulates an antiviral state and drives the adaptive immune system toward an efficient and specific response against the ongoing infection. One of the best-characterized natural RIG-I agonists is the defective interfering (DI) RNA produced by Sendai virus strain Cantell. This 546-nucleotide RNA is a well-known activator of the innate immune system and an extremely potent inducer of type I interferon. We designed anin vitro-transcribed RNA that retains the type I interferon stimulatory properties, and the RIG-I affinity of the Sendai virus produced DI RNA bothin vitroandin vivo. Thisin vitro-synthesized RNA is capable of enhancing the production of anti-influenza virus hemagglutinin (HA)-specific IgG after intramuscular or intranasal coadministration with inactivated H1N1 2009 pandemic vaccine. Furthermore, our adjuvant is equally effective at increasing the efficiency of an influenza A/Puerto Rico/8/34 virus inactivated vaccine as a poly(I·C)- or a squalene-based adjuvant. Ourin vitro-transcribed DI RNA represents an excellent tool for the study of RIG-I agonists as vaccine adjuvants and a starting point in the development of such a vaccine.
Subcellular Localization and Function of an Epitope-Tagged p7 Viroporin in Hepatitis C Virus-Producing Cells
Authors: Vieyres Gabrielle , Brohm Christiane , Friesland Martina , Gentzsch Juliane , Wölk Benno , Roingeard Philippe , Steinmann Eike , Pietschmann Thomas
Published: November 2012

The hepatitis C virus (HCV) viroporin p7 is crucial for production of infectious viral progeny. However, its role in the viral replication cycle remains incompletely understood, in part due to the poor availability of p7-specific antibodies. To circumvent this obstacle, we inserted two consecutive hemagglutinin (HA) epitope tags at its N terminus. HA-tagged p7 reduced peak virus titers ca. 10-fold and decreased kinetics of virus production compared to the wild-type virus. However, HA-tagged p7 rescued virus production of a mutant virus lacking p7, thus providing formal proof that the tag does not disrupt p7 function. In HCV-producing cells, p7 displayed a reticular staining pattern which colocalized with the HCV envelope glycoprotein 2 (E2) but also partially with viral nonstructural proteins 2, 3, and 5A. Using coimmunoprecipitation, we confirmed a specific interaction between p7 and NS2, whereas we did not detect a stable interaction with core, E2, or NS5A. Moreover, we did not observe p7 incorporation into affinity-purified virus particles. Consistently, there was no evidence supporting a role of p7 in viral entry, as an anti-HA antibody was not able to neutralize Jc1 virus produced from an HA-p7-tagged genome. Collectively, these findings highlight a stable interaction between p7 and NS2 which is likely crucial for production of infectious HCV particles. Use of this functional epitope-tagged p7 variant should facilitate the analysis of the final steps of the HCV replication cycle.
A randomised controlled trial of hospital-based case management to improve colorectal cancer patients’ health-related quality of life and evaluations of care
Authors: Wulff Christian Nielsen , Vedsted Peter , Søndergaard Jens
Published: November 2012

Objective

To analyse the effectiveness of hospital-based case management (CM) in terms of patient-reported outcomes.

Design

Randomised controlled trial allocating participants 1 : 1 to either a CM intervention or a control group. Allocation status was evident to participants and case managers, but blinded to researchers.

Setting

Patients were recruited at a Danish surgical department where the case managers were situated.

Participants

Colorectal cancer patients who were to undergo further investigation or treatment. Exclusion criteria were participation in another study, poor Danish language skills or apparent cognitive impairment. 140 participants were randomised to each group. Recruitment period was 11 March 2009 to 29 December 2010.

Interventions

Control group patients had usual care. Intervention group patients had usual care supplemented by hospital-based CM started at first visit to the out-patient clinic (before treatment start) and ended 4 weeks after completed cancer treatment. CM was conducted by nurse case managers who undertook care pathway supervision, information dissemination to health professionals and outreaching patient support.

Outcome measures

Patient-reported global quality of life measured with the EORTC QLQ-C30 and eight ad hoc, piloted patient evaluation items assessed at eight, 30 and 52 weeks after randomisation.

Results

The two groups were comparable as to questionnaire response rates and completed scales/items. There were no statistically significant group differences on any of the health-related quality of life subscales at eight, 30 or 52 weeks. In patient evaluations, all point estimates favoured CM at week 8 and 30; at week 52, 6 of 7 estimates favoured CM.

Conclusions

We found no evidence that CM influenced colorectal cancer patients’ health-related quality of life. Patients allocated to CM evaluated their care more positively than patients receiving usual care.

Trial registration

Clinicaltrials.gov identifier:NCT00845247.
Timing of gastrostomy insertion in children with a neurodisability: a cross-sectional study of early versus late intervention
Authors: Sharma Raman , Williams Andrew N , Zaw Win
Published: November 2012

Objectives

The aim of the study was to assess whether gastrostomy placement before 18 months of age results in a greater increase in z-score for weight and to assess whether admission rates were reduced postgastrostomy in this age group.

Design

Retrospective cross-sectional study.

Setting

Single-centre secondary care District General Hospital.

Participants

All children with a neurodisability with a gastrostomy in situ in September 2011 were included. Those with primary neoplasia and undergoing chemo or radiotherapy or being palliated for an aggressive neurodegenerative disorder were excluded. Those with cystic fibrosis, primary congenital heart disease or Inflammatory bowel disease were also excluded. Forty-one children underwent final analysis. Twenty-four children underwent gastrostomy insertion less than 18 months and 17 children were older than 18 months.

Primary and secondary outcome measures

Primary outcome was z-scores for weight immediately pregastrostomy and 12 months postgastrostomy. Secondary outcomes were hospital admission rates pregastrostomy and postgastrostomy. Values were compared for those with gastrostomy insertion less than or equal to 18 months against those older than 18 months at insertion.

Results

Z-score for weight increased significantly in both age groups. There was significantly increased mean difference in the z-score for weight of +1.33 pregastrostomy and postgastrostomy in the less than 18 months age group as compared with an increased mean difference in the z-score for weight of +0.45 in the older age group (p=0.021). There was no significant difference in the admission rates postgastrostomy insertion in either age group.

Conclusions

Gastrostomy insertion before 18 months of age results in greater z-score for weight gain in children with a neurodisability. This conclusion is limited by the lack of height and skin-fold thickness measurements. Further long-term matched control studies are required to determine the neurodevelopmental and clinical benefit of early gastrostomy placement in such children.
Paediatric autoimmune encephalopathies: clinical features, laboratory investigations and outcomes in patients with or without antibodies to known central nervous system autoantigens
Authors: Hacohen Yael , Wright Sukhvir , Waters Patrick , Agrawal Shakti , Carr Lucinda , Cross Helen , De Sousa Carlos , DeVile Catherine , Fallon Penny , Gupta Rajat , Hedderly Tammy , Hughes Elaine , Kerr Tim , Lascelles Karine , Lin Jean-Pierre , Philip Sunny , Pohl Keith , Prabahkar Prab , Smith Martin , Williams Ruth , Clarke Antonia , Hemingway Cheryl , Wassmer Evangeline , Vincent Angela , Lim Ming J
Published: November 2012

Objective

To report the clinical and investigative features of children with a clinical diagnosis of probable autoimmune encephalopathy, both with and without antibodies to central nervous system antigens.

Method

Patients with encephalopathy plus one or more of neuropsychiatric symptoms, seizures, movement disorder or cognitive dysfunction, were identified from 111 paediatric serum samples referred from five tertiary paediatric neurology centres to Oxford for antibody testing in 2007–2010. A blinded clinical review panel identified 48 patients with a diagnosis of probable autoimmune encephalitis whose features are described. All samples were tested/retested for antibodies to N-methyl-D-aspartate receptor (NMDAR), VGKC-complex, LGI1, CASPR2 and contactin-2, GlyR, D1R, D2R, AMPAR, GABA(B)R and glutamic acid decarboxylase.

Results

Seizures (83%), behavioural change (63%), confusion (50%), movement disorder (38%) and hallucinations (25%) were common. 52% required intensive care support for seizure control or profound encephalopathy. An acute infective organism (15%) or abnormal cerebrospinal fluid (32%), EEG (70%) or MRI (37%) abnormalities were found. One 14-year-old girl had an ovarian teratoma. Serum antibodies were detected in 21/48 (44%) patients: NMDAR 13/48 (27%), VGKC-complex 7/48(15%) and GlyR 1/48(2%). Antibody negative patients shared similar clinical features to those who had specific antibodies detected. 18/34 patients (52%) who received immunotherapy made a complete recovery compared to 4/14 (28%) who were not treated; reductions in modified Rankin Scale for children scores were more common following immunotherapies. Antibody status did not appear to influence the treatment effect.

Conclusions

Our study outlines the common clinical and paraclinical features of children and adolescents with probable autoimmune encephalopathies. These patients, irrespective of positivity for the known antibody targets, appeared to benefit from immunotherapies and further antibody targets may be defined in the future.
Current insights and controversies in the pathogenesis and diagnosis of disc‐associated cervical spondylomyelopathy in dogs
Authors: De Decker S. , da Costa R. C. , Volk H. A. , Van Ham L. M. L.
Published: November 2012

Disc‐associated cervical spondylomyelopathy (DA‐CSM) is the most common cause of cervical spondylomyelopathy in dogs. In this condition, progressive caudal cervical spinal cord compression is typically caused by protrusion of one or more intervertebral discs. This disc‐associated compression is sometimes seen in combination with mild vertebral abnormalities and dorsal compression resulting from ligamentum flavum hypertrophy. The intervertebral disc space between the sixth (C6) and seventh (C7) cervical vertebrae is most commonly affected. Although several large breed dogs can be affected, the adult to older dobermann is overrepresented. Clinical signs vary from cervical hyperaesthesia to tetraplegia. Dogs can present with a chronic progressive or an acute onset of clinical signs. Many aspects of this multifactorial neurological syndrome are not completely understood and are the subject of controversy and debate. Although several factors have been proposed, the underlying pathology and aetiology remain unknown. Recently, new insights have been gained in the pathogenesis, diagnosis and treatment of this challenging neurological syndrome. This review outlines current controversies and new developments concerning the pathogenesis and diagnosis of DA‐CSM.
Effects of high-intensity exercise training on body composition, abdominal fat loss, and cardiorespiratory fitness in middle-aged Korean females
Authors: Lee Man-Gyoon , Park Kyung-Shin , Kim Do-Ung , Choi Soon-Mi , Kim Hyoung-Jun
Published: November 2012

The primary purpose of this study was to investigate the effects of high-intensity exercise training under relatively equal energy expenditure on whole body fat and abdominal fat loss, and cardiorespiratory fitness. Twenty-two untrained middle-aged Korean females were randomized into one of the following groups: control, low-intensity training group (LI), and high-intensity training group (HI). Subjects completed 14 weeks of training at 50% maximal oxygen consumption (LI) or 70% maximal oxygen consumption (HI) with the volume of exercise equated relative to kilograms of body weight. Weekly exercise volumes were 13.5 METs⋅h/week for the first 4 weeks, 18 METs⋅h/week for next 5 weeks, and 22.5 METs⋅h/week for the final 5 weeks. Data were analyzed using 2-way repeated measures ANOVA with post hoc test, using Bonferroni’s correction. HI showed significant reductions in fat mass (p < 0.05), total abdominal fat (p < 0.01), and subcutaneous abdominal fat (p < 0.01). LI reduced total abdominal fat (p < 0.05), but there were no other significant changes found in the control or LI groups. Maximal oxygen consumption was enhanced in both HI and LI with no significant group difference. High-density lipoprotein cholesterol increased significantly in HI (p < 0.05). IL-6, C-reactive protein, TNF-α, and other blood lipids were unaltered following training. Results indicate that high-intensity exercise training is more beneficial in whole body and abdominal fat loss; however, cardiorespiratory enhancement shows a dose–response relationship with weekly exercise volume. It is suggested that 14 weeks of aerobic exercise training at either high- or low-intensity is not sufficient enough to induce changes in levels of inflammatory proteins.
Changes in traditional chronic disease risk factors over time and their relationship with leisure-time physical activity in people living with spinal cord injury
Authors: Buchholz Andrea C. , Horrocks Julie , Martin Ginis Kathleen A. , Bray Steven R. , Craven B. Catharine , Hicks Audrey L. , Hayes Keith C. , Latimer Amy E. , McColl Mary Ann , Potter Patrick J. , Smith Karen , Wolfe Dalton L.
Published: November 2012

This study examined whether levels of chronic disease risk factors change over time, and whether leisure-time physical activity (LTPA) can explain any of the variation in those risk factors that change, in a sample of community-dwelling people living with spinal cord injury (SCI) in or near Hamilton, Ontario, Canada. LTPA was measured using the Physical Activity Recall Assessment for People with SCI at baseline (n = 76 adults with chronic (≥1 year) paraplegia or tetraplegia), at 6 months (n = 71) and at 18 months (n = 63). Body mass index, waist circumference at the lowest rib (WClowest rib) and iliac crest (WCiliac crest), fat mass, blood pressure, and biochemical data were collected at all 3 time points. Women’s BMI was higher at baseline (least square means (LSM) = 26.2 ± SE = 1.56 kg·m–2, p = 0.0004) and 6 months (25.9 ± 1.6, p = 0.0024) than at 18 months (22.1 ± 1.72). Men’s WClowest ribincreased from baseline (92.1 ± 1.87 cm) to 18 months (93.6 ± 1.87, p = 0.0253). Women who were active vs. inactive at baseline had a lower BMI at 6 months (23.1 ± 2.91 vs. 29.7 ± 2.52, p = 0.0957) and WCiliac crestat 6 months (82.8 ± 6.59 vs. 97.7 ± 5.10, p = 0.0818). Women who were active vs. inactive at 6 months had a lower WCiliac crestat 18 months (73.4 ± 14.3 vs. 102.5 ± 6.41, p = 0.0723). There was little change in traditional risk factors over 18 months. Future studies should extend beyond 18 months in a larger sample, and explore traditional vs. novel risk factors and onset of cardiovascular disease and diabetes in the SCI population.
Time to exhaustion at intermittent maximal lactate steady state is longer than continuous cycling exercise
Authors: Grossl Talita , de Lucas Ricardo Dantas , de Souza Kristopher Mendes , Guglielmo Luiz Guilherme Antonacci
Published: November 2012

The maximal lactate steady state (MLSS) represents a submaximal intensity that may be important in prescribing both continuous and interval endurance training. This study compared time to exhaustion (TTE) at MLSS in continuous and intermittent (i.e., with pauses) exercise, investigating whether physiological variables differ between these exercise modes. Fourteen trained male cyclists volunteered for this investigation and performed an incremental test, several 30-min tests to determine two MLSS intensities (continuous and discontinuous protocol), and two randomized tests until exhaustion at MLSS intensities on a cycle ergometer. The intermittent or discontinuous protocol was performed using 5 min of cycling, with an interval of 1 min of passive rest. TTE at intermittent MLSS was 24% longer than TTE at continuous exercise (67.8 ± 14.3 min vs. 54.7 ± 10.9 min; p < 0.05; effect sizes = 1.04), even though the absolute power output of intermittent MLSS was higher than continuous (268 ± 29 W vs. 251 ± 29 W; p < 0.05). Additionally, the total mechanical work done was significantly lower at continuous exercise than at intermittent exercise. Likewise, regarding cardiorespiratory and metabolic variables, we observed greater responses during intermittent exercise than during continuous exercise at MLSS. Thus, for endurance training prescription, this is an important finding to apply in extensive interval sessions at MLSS. This result suggests that interval sessions at discontinuous MLSS should be used instead of continuous MLSS, as discontinuous MLSS allows for a larger amount of total work during the exhaustion trial.
Intermittent lower-limb occlusion enhances recovery after strenuous exercise
Authors: Beaven Christopher Martyn , Cook Christian John , Kilduff Liam , Drawer Scott , Gill Nicholas
Published: November 2012

Repeated cycles of vascular occlusion followed by reperfusion initiate a protective mechanism that acts to mitigate future cell injury. Such ischemic episodes are known to improve vasodilation, oxygen utilization, muscle function, and have been demonstrated to enhance exercise performance. Thus, the use of occlusion cuffs represents a novel intervention that may improve subsequent exercise performance. Fourteen participants performed an exercise protocol that involved lower-body strength and power tests followed by repeated sprints. Occlusion cuffs were then applied unilaterally (2 × 3-min per leg) with a pressure of either 220 (intervention) or 15 mm Hg (control). Participants immediately repeated the exercise protocol, and then again 24 h later. The intervention elicited delayed beneficial effects (24 h post-intervention) in the countermovement jump test with concentric (effect size (ES) = 0.36) and eccentric (ES = 0.26) velocity recovering more rapidly compared with the control. There were also small beneficial effects on 10- and 40-m sprint times. In the squat jump test there were delayed beneficial effects of occlusion on eccentric power (ES = 1.38), acceleration (ES = 1.24), and an immediate positive effect on jump height (ES = 0.61). Thus, specific beneficial effects on recovery of power production and sprint performance were observed both immediately and 24 h after intermittent unilateral occlusion was applied to each leg.
Haematological changes in elite kayakers during a training season
Authors: Borges Grasiely Faccin , Rama Luis Manuel Pinto Lopes , Pedreiro Susana , Rosado Fátima , Alves Francisco , Santos Amândio Manuel Cupido , Paiva Artur , Teixeira Ana Maria
Published: November 2012

This study monitored haematological markers in response to training load in elite kayakers during a training season. The sample comprised eight elite kayakers aged 22 ± 4.2 years with a 77.2 ± 6.7 kg body mass and a 177.5 ± 5.6 cm stature. The initial [Formula: see text]O2max was 61.2 ± 5.5 mL·kg–1·min–1. The control group consisted of six healthy males, aged 18.6 ± 1.1 years, with an 81.3 ± 13.8 kg body mass and a 171.9 ± 4.5 cm stature. Blood samples were collected at the beginning of the training season after an off-training period of six weeks (t0), at the 11th week after the application of high training volumes (t1), at the 26th week after an intense training cycle (t2), and at the 31st week at the end of a tapering phase (t3). Differences between time points were detected using ANOVA and the Bonferroni post hoc test. Significant changes were found after the intense training cycle (t2), lymphocytes decreased while haemoglobin, mean corpuscular volume, mean corposcular haemoglobin, mean concentration of corpuscular hemoglobin concentration, platelets distribution width, and red blood cell distribution width values increased when compared with baseline values. At t3, a reduction in monocyte numbers and an increase in mean platelet volume compared with baseline values were seen. By reducing the volume and intensity of training, many variables returned to values close to those at baseline. Although many athletes had accumulated responses over time due to training, they still suffered transient changes that appear to be influenced by training load. Haemorheology monitoring may help detect health risks, especially during times of intensified training.
Tissue-specific sex differences in docosahexaenoic acid and Δ6-desaturase in rats fed a standard chow diet
Authors: Kitson Alex P. , Smith Tracy L. , Marks Kristin A. , Stark Ken D.
Published: November 2012

Docosahexaenoic acid (DHA, 22:6n-3) is higher in the blood and tissues of females relative to males, but the underlying mechanism is not clear. The present study examined the expression of enzymes involved in the biosynthesis of DHA from short-chain n-3 polyunsaturated fatty acids in male and female rats (n = 6 for each sex). Rats were maintained on an AIN-93G diet and sacrificed at 14 weeks of age after an overnight fast. Plasma, erythrocytes, liver, heart, and brain were collected for fatty acid composition analysis and the determination of enzyme and transcription factor expression by RT-PCR and immunoblotting. Females had higher DHA concentrations in the total lipids of liver, plasma, erythrocyte, and heart (53%, 75%, 36%, and 25% higher, respectively, compared with males) with no sex differences in brain DHA concentrations. The mRNA content of Δ5-desaturase, Δ6-desaturase, and elongase 2 was 1.0-, 1.4-, and 1.1-fold higher, respectively, in the livers of female rats compared with males, with no differences in the hearts or brains. The protein content of Δ6-desaturase was also higher in females. Higher hepatic mRNA of sterol-regulatory element-binding protein 1-c and estrogen receptor α in the females suggests that lipogenic and estrogen signaling mechanisms are involved. The sex difference in DHA concentration is tissue specific and is associated with higher Δ6-desaturase expression in females relative to males, which appears to be limited to the liver.
Cardiovascular and autonomic effects of water ingestion during postexercise circulatory occlusion
Authors: Mendonca Goncalo V. , Teixeira Micael S. , Pereira Fernando D. , Fernhall Bo
Published: November 2012

As with water ingestion, the activation of the muscle metaboreflex leads to heightened muscle sympathetic nerve activity. Thus, we hypothesized that water ingestion might enhance the pressor effect of the muscle metaboreflex activation. We examined the effect of water ingestion (50 vs. 500 mL) on the cardiovascular and autonomic responses to static handgrip followed by postexercise circulatory occlusion (PECO) in 19 healthy participants (29.2 ± 8.6 years). Beat-to-beat blood pressure, baroreflex sensitivity (BRS), and R-R intervals were recorded in both conditions (pre- and postingestion). Changes in stroke volume and cardiac output were assessed using Modelflow. Cardiac autonomic regulation was investigated by spectral heart rate variability (HRV); baroreflex control of heart rate was assessed by the sequence method. Water ingestion did not increase the pressor effect induced by PECO. Even though 500 mL of water elicited an overall bradycardia, paired by an increase in the high-frequency HRV, there were no differences between conditions for the decrease in BRS or the resetting of the baroreflex to operate at higher blood pressure. Nevertheless, after the ingestion of 500 mL of water, there were no significant correlations between the percent change in cardiac output and that of BRS, from rest to PECO. This contrasts with that seen in the 50 mL condition (r = –0.68, p < 0.05). Contrasting with our hypothesis, 500 mL of water did not increase the pressor effect induced by PECO. Nevertheless, we found that water ingestion may influence the mechanisms by which the muscle metaboreflex elicits an increased cardiac output during PECO.
Oxidative stress is associated with visceral adipose tissue and subclinical atherosclerosis in a healthy multi-ethnic population
Authors: Lear Scott A. , Sarna Lindsei K. , Siow Timothy J. , Mancini G.B. John , Siow Yaw L. , O Karmin
Published: November 2012

Oxidative stress plays an important role in the development of atherosclerosis. Excess visceral adipose tissue (VAT) and increased carotid intima-media thickness (IMT) are risk factors for coronary artery disease. We tested the hypothesis that VAT and IMT were associated with systemic oxidative stress. Healthy men and women (n = 565) matched for ethnicity (Aboriginal, Chinese, European, and South Asian) were recruited. Plasma malondialdehyde, a biomarker of oxidative stress, was measured as thiobarbituric acid reactive substances (TBARS). VAT and IMT were determined by computerized tomography and ultrasound scans, respectively. Plasma TBARS levels correlated with VAT and total atheroma burden (sum of IMT area and plaque area) in the entire cohort. When stratified by ethnicity, plasma TBARS levels correlated with distinct body composition and arterial measures in different ethnic populations with more associations present amongst Chinese and Europeans relative to Aboriginals and South Asians. VAT was associated with plasma TBARS levels independent of age, sex, ethnicity, smoking, and body mass index. Plasma TBARS levels were associated with IMT, the presence of plaques, and total atheroma burden, independent of age, sex, ethnicity, smoking, body mass index, and VAT. The association with total atheroma burden remained significant even when adjusted for apolipoprotein B. Results from the present study indicate that oxidative stress is positively associated with VAT as well as diffuse and focal carotid atherosclerosis in apparently healthy men and women.
Energy expenditure during the LANY Footrace 2011 – a case study
Authors: Ardigò Luca Paolo , Capelli Carlo
Published: November 2012

We reported results obtained in estimating the energy expenditure (EE) of an active adult subject participating in LANY Footrace 2011 (5129 km, 70 consecutive days). At each stage EE was calculated from literature metabolic cost equations and GPS-measured speeds–inclines. The subject’s average speed was 7.41 ± 0.51 km·h–1. Race expenditure amounted to 87% of EE (31.3 MJ·day–1) (47.8%–37.1% of measured maximal oxygen uptake). These results provide data about EE for future stage-type ultra-endurance competitors.
Greater prevalence of select chronic conditions among Aboriginal and South Asian participants from an ethnically diverse convenience sample of British Columbians
Authors: Foulds Heather J.A. , Bredin Shannon S.D. , Warburton Darren E.R.
Published: November 2012

Canadians currently experience elevated rates of chronic conditions compared with past populations, and ethnic differences in the experience of select chronic conditions have previously been identified. This investigation examined the prevalence of select chronic conditions among an ethnically diverse convenience sample of British Columbian adults. A sample of adults (≥18 years) from around the province of British Columbia, including Aboriginal (n = 991), European (n = 3650), East Asian (n = 466), and South Asian (n = 228), were evaluated. Individuals reported their personal histories of cardiovascular disease and diabetes, and physical activity behaviour. Direct measures of health status included body mass index, waist circumference, resting blood pressure, and nonfasting blood glucose, total cholesterol, high-density lipoprotein (HDL) cholesterol, and glycosylated hemoglobin A1C. All ethnic groups were found to have high rates of low HDL (>33%), physical inactivity (>31%), hypertension (>16%), and ethnic-specifically defined obesity (>23%) and abdominal obesity (>33%). Aboriginal and South Asian populations generally demonstrated higher rates of select chronic conditions. The implementation of ethnic-specific body composition recommendations further underscores this poorer health status among South Asian populations. Actions to improve chronic condition rates should be undertaken among all ethnic groups, with particular attention to Aboriginal and South Asian populations.
Exogenous modification of platelet membranes with the omega-3 fatty acids EPA and DHA reduces platelet procoagulant activity and thrombus formation
Authors: Larson Mark K. , Tormoen Garth W. , Weaver Lucinda J. , Luepke Kristen J. , Patel Ishan A. , Hjelmen Carl E. , Ensz Nicole M. , McComas Leah S. , McCarty Owen J. T.
Published: November 2012

Several studies have implicated the omega-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) in inhibition of normal platelet function, suggesting a role for platelets in EPA- and DHA-mediated cardioprotection. However, it is unclear whether the cardioprotective mechanisms arise from alterations to platelet-platelet, platelet-matrix, or platelet-coagulation factor interactions. Our previous results led us to hypothesize that EPA and DHA alter the ability of platelets to catalyze the generation of thrombin. We tested this hypothesis by exogenously modifying platelet membranes with EPA and DHA, which resulted in compositional changes analogous to increased dietary EPA and DHA intake. Platelets treated with EPA and DHA showed reductions in the rate of thrombin generation and exposure of platelet phosphatidylserine. In addition, treatment of platelets with EPA and DHA decreased thrombus formation and altered the processing of thrombin precursor proteins. Furthermore, treatment of whole blood with EPA and DHA resulted in increased occlusion time and a sharply reduced accumulation of fibrin under flow conditions. These results demonstrate that EPA and DHA inhibit, but do not eliminate, the ability of platelets to catalyze thrombin generation in vitro. The ability of EPA and DHA to reduce the procoagulant function of platelets provides a possible mechanism behind the cardioprotective phenotype in individuals consuming high levels of EPA and DHA.
Ouabain downregulates Mcl-1 and sensitizes lung cancer cells to TRAIL-induced apoptosis
Authors: Chanvorachote Pithi , Pongrakhananon Varisa
Published: November 2012

Resistance to tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a prerequisite for cancer progression, and TRAIL resistance is prevalent in lung cancer. Ouabain, a recently identified human hormone, has shown therapeutic promise by potentiating the apoptotic response of metastatic lung cancer cells to TRAIL. Nontoxic concentrations of ouabain are shown to increase caspase-3 activation, poly(ADP-ribose) polymerase (PARP) cleavage, and apoptosis of H292 cells in response to TRAIL. While ouabain had a minimal effect on c-FLIP, Bcl-2, and Bax levels, we show that it possesses an ability to downregulate the antiapoptotic Mcl-1 protein. The present study also reveals that the sensitizing effect of ouabain is associated with its ability to generate reactive oxygen species (ROS), and hydrogen peroxide is identified as the principle ROS triggering proteasomal Mcl-1 degradation. In summary, our results indicate a novel function for ouabain in TRAIL-mediated cancer cell death through Mcl-1 downregulation, thereby providing new insight into a potential lung cancer treatment as well as a better understanding of the physiological activity of ouabain.
Mis-expression of the BK K+ channel disrupts suprachiasmatic nucleus circuit rhythmicity and alters clock-controlled behavior
Authors: Montgomery Jenna R. , Whitt Joshua P. , Wright Breanne N. , Lai Michael H. , Meredith Andrea L.
Published: November 2012

In mammals, almost all aspects of circadian rhythmicity are attributed to activity in a discrete neural circuit of the hypothalamus, the suprachiasmatic nucleus (SCN). A 24-h rhythm in spontaneous firing is the fundamental neural intermediary to circadian behavior, but the ionic mechanisms that pattern circuit rhythmicity, and the integrated impact on behavior, are not well studied. Here, we demonstrate that daily modulation of a major component of the nighttime-phased suppressive K+ current, encoded by the BK Ca2+-activated K+ current channel (KCa1.1 or Kcnma1), is a critical arbiter of circadian rhythmicity in the SCN circuit. Aberrant induction of BK current during the day in transgenic mice using a Per1 promoter ( Tg-BK R207Q) reduced SCN firing or silenced neurons, decreasing the circadian amplitude of the ensemble circuit rhythm. Changes in cellular and circuit excitability in Tg-BK R207Q SCNs were correlated with elongated behavioral active periods and enhanced responses to phase-shifting stimuli. Unexpectedly, despite the severe reduction in circuit amplitude, circadian behavioral amplitudes in Tg-BK R207Q mice were relatively normal. These data demonstrate that downregulation of the BK current during the day is essential for the high amplitude neural activity pattern in the SCN that restricts locomotor activity to the appropriate phase and maintains the clock's robustness against perturbation. However, a residually rhythmic subset prevails over the ensemble circuit to drive the fundamental circadian behavioral rhythm.