bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactive Transport, Subcellular Relocation and Enhanced Phototoxicity of Hypericin Encapsulated in Guanidinylated Liposomes via Molecular Recognition†
Authors: Galanou Maria C. , Theodossiou Theodossis A. , Tsiourvas Dimitris , Sideratou Zili , Paleos Constantinos M.
Published: July 2008

Hypericin (HYP), a photocytotoxic phenanthroperylenquinone was encapsulated in liposomes outfitted with guanidinium‐bearing lipids to ensure efficient cell binding through molecular recognition with anionic groups resident on the plasma membrane. The uptake of HYP encapsulated in these liposomes by DU145 human prostate cancer cells, was studied employing fluorescence, versus nonguadinylated liposomes and free HYP. The subcellular localization was in all cases studied by confocal microscopy employing specific subcellular organelle probes. The photocytotoxicity of HYP was assessed, 24 h following irradiation with 15 mWcm−2 light through a GG 495 Schott filter, by a standard tetrazolium to formazan assay (XTT). HYP uptake by DU145 cells was found to be profoundly enhanced by using guanidinylated liposomes. Also the distance of the guanidinium group from the liposomal surface was found to significantly affect HYP loading, subcellular localization and phototoxicity. The two different modes of liposome cell internalization observed, i.e. plasma membrane fusion and endocytosis, were found to greatly affect the phototoxicity of HYP. Molecular recognition was overall appraised as a promising, novel route for photodynamic therapy, profoundly enhancing its efficacy. HYP encapsulated in liposomes‐bearing guanidinium groups was more efficiently taken up by cells, leading to enhanced phototoxicity, in contrast to HYP encapsulated in their nonguanidinylated counterparts.
Psychological Stress and Oxidative Damage in Lymphocytes of Aerobically Fit and Unfit Individuals1
Authors: Knickelbein Kelly Z. , Flint Melanie , Jenkins Frank , Baum Andrew
Published: July 2008

Habitual aerobic exercise has a beneficial effect on many systems of the body, and psychological stress has a negative influence on several of the same systems. One possible pathway is through those systems that account for the detrimental effects of stress; by buffering these harmful effects, exercise may reduce the consequences of stress. This study examined increased resistance of cells to stress‐induced oxidative damage as a result of fitness. Forty healthy participants were assigned to either a stress group or a no‐stress control group, and measures of stress and oxidative damage were collected. Variation in fitness level across participants was also measured. Oxidative damage increased as a function of stress, but this was not buffered by fitness level. These results should be interpreted with caution because of the small sample size and the limited variability of cardiorespiratory fitness levels in the sample.
Psychosocial Correlates of Cardiovascular Reactivity to Anticipation of an Exercise Stress Test Prior to Attending Cardiac Rehabilitation: A Preliminary Test1
Authors: Fraser Shawn N. , Rodgers Wendy M. , Daub Bill
Published: July 2008

We examined social and psychological correlates of cardiovascular reactivity (CVR), or exaggerated heart rate (HR) and blood pressure (BP) responses to mental stress, in 45 men (mean age = 60.1, SD = 9.9) and 17 women (mean age = 9.9, SD = 11.8) prior to cardiac rehabilitation. HR and BP increased from rest to anticipation, and women had higher resting and preexercise BP. Anxiety was positively related to HR reactivity. HR reactivity was negatively related to self‐efficacy in women and positively related to self‐efficacy in men. Men and women with more self‐efficacy had lower systolic blood pressure (SBP) reactivity, and anxiety was positively related to SBP reactivity in women. Results suggest that the relationship among psychosocial factors and CVR might differ among men and women.
Cognitive and Physiological Determinants of Symptom Perception and Interpretation
Authors: Nakajima Motohiro , Fleming Raymond
Published: July 2008

The purpose of the current study was to test the aspects of MacGregor and Fleming's model of symptom reporting and illness interpretation. Participants were randomly assigned to cognitive cue (Chemical or No Chemical), sensory cue (Odor or No Odor), and somatic arousal (Exercise or No Exercise) conditions. The findings suggested that although somatic arousal primarily determines whether one experiences symptoms, and expectations—or one's mental model—determine the nature of the attribution regarding the cause of the symptoms, it appears that both the attribution about the cause of the symptoms and the amount of somatic arousal experienced combine to produce the intensity of negative symptoms.
Mediterranean gasoline surplus and diesel shortage: the impending conversion bottleneck1
Authors: Guarerra Lisa
Published: July 2008

Despite an increase in refinery capacities and an expected global reduction in oil product deficit in the Mediterranean at horizon 2015, the future of the region appears troubled. With little time on their hands to adjust and upgrade their refineries, Mediterranean countries will need to face the growing demand for desulphurised diesel, while their current main provider, Russia, is looking less likely to supply the required quantities and quality over the coming years. The increasing surpluses of gasoline of the region seem to be likely to exceed the needs of its main importers, the USA and European Union, and could possibly lead to future predicaments for the industry, the region and its populations. Moreover, current and foreseen environmental measures are likely to reinforce the imbalance of the region.
Conservation action in a changing climate
Authors: McClanahan T.R. , Cinner J.E. , Maina J. , Graham N.A.J. , Daw T.M. , Stead S.M. , Wamukota A. , Brown K. , Ateweberhan M. , Venus V. , Polunin N.V.C.
Published: July 2008

Climate change will pose new challenges to conserving Earth's natural ecosystems, due to incremental changes in temperature and weather patterns, and to increased frequency and intensity of extreme climate events. Addressing these challenges will require pragmatic conservation actions informed by site‐specific understanding of susceptibility to climate change and capacity of societies to cope with and adapt to change. Depending on a location's environmental susceptibility and social adaptive capacity, appropriate conservation actions will require some combination of: (1) large‐scale protection of ecosystems; (2) actively transforming and adapting social‐ecological systems; (3) building the capacity of communities to cope with change; and (4) government assistance focused on de‐coupling communities from dependence on natural resources. We apply a novel analytical framework to examine conservation actions in five western Indian Ocean countries, where climate‐mediated disturbance has impacted coral reefs and where adaptive capacity differs markedly. We find that current conservation strategies do not reflect adaptive capacity and are, therefore, ill prepared for climate change. We provide a vision for conservation policies that considers social adaptive capacity that copes with complexities of climate change better than the singular emphasis on government control and the creation of no‐take areas.
Novel ecosystems resulting from landscape transformation create dilemmas for modern conservation practice
Authors: Lindenmayer David B. , Fischer Joern , Felton Adam , Crane Mason , Michael Damian , Macgregor Christopher , Montague‐Drake Rebecca , Manning Adrian , Hobbs Richard J.
Published: July 2008

Introduction: Novel ecosystems occur when new combinations of species appear within a particular biome due to human activity, environmental change, or impacts of introduced species. Background: Managing the trajectory of ecosystems toward desired outcomes requires an understanding of the means by which they developed. To facilitate this understanding, we present evidence for the development of a novel ecosystem from a natural experiment focusing on 52 woodland remnants surrounded by maturing stands of exotic radiata pine. Results: Bird community composition changed through time resulting in a unique blend of tall closed forest and open‐woodland birds that previously did not occur in the study area, nor in the region's tall closed forest or open‐woodland biomes. Conclusion: Novel ecosystems will become increasingly common due to climate change, raising complex management and ethical dilemmas for policy makers and resource managers.
Accounting for Intangible Investments
Authors: Wyatt Anne , Abernethy Margaret
Published: July 2008

The traditional categorisation of expenditures evident in many firms' charts of accounts and financial statements does not identify and measure expenditures on intangible investment separately from tangible investment and operating expenditures. This contrasts with the accounting for tangible investment, which separately accounts for all expenditures as assets unless the future benefits are consumed in a single accounting period. Further, in searching for better ways to account for intangibles, regulators and researchers have focused on the accounting choice problem relating to the existence and recognisability of intangible assets. In this paper, we argue that identifying and separately reporting the expenditures on intangible investment is the logical first step in accounting for intangible investments. Learning about the firm's categories of value driving (and sometimes potentially value destroying) expenditures has important implications for understanding aspects of the value chain, performance measurement, valuation, corporate governance and the external audit.
Australian Public‐Sector Outsourcing in the ‘Golden Era’: Cost Savings Evidence or Anecdote?
Authors: Bisman Jayne Elizabeth
Published: July 2008

This paper reports a multi‐method study of the watershed period of Australian public‐sector outsourcing from the mid‐1990s to 2000. Interviews and a large‐scale survey conducted with Australian public‐sector managers indicate a number of shortfalls in decision‐making and decision‐evaluation processes from accounting and policy compliance perspectives. The results suggest that the cost‐savings objective was given a low level of importance, that transaction‐cost data were rarely used in decision‐making, and that ex‐post decision evaluation of the cost outcomes from outsourcing was minimal. These results are also reinterpreted and implications drawn in light of the current contracting practices of Australian public‐sector organisations.
The Effect of Board‐Related Reforms on Investors' Confidence
Authors: Lee Janet , Shailer Greg
Published: July 2008

We survey Australian institutional and individual investors regarding how board‐related reforms in the Australian Stock Exchange Corporate Governance Council 2003 recommendations and changes to the Corporations Act 2001 in 2004 affect their confidence as investors. The overall results are consistent with suggestions that individual and institutional investors differ in their corporate governance preferences and expectations. The results reveal that, for both individual and institutional investors, the average investor's confidence is improved by increased independence of the board and its committees, increased disclosures of corporate governance information, and CEO and CFO responsibility for the integrity of financial statements. The effect is strongest for individual investors, who also expect greater time commitments by non‐executive directors. Institutional investors appear to have more concern for directors' competence or networking.
The Effect of Board Independence on Target Shareholder Wealth
Authors: Clarkson Peter M. , Craswell Allen , Mackenzie Prue
Published: July 2008

We seek insights into whether, and if so how, an independent board enhances the bid premiums offered to target firm shareholders during a takeover. The results indicate that the presence of an independent board enhances the initial bid premium by, on average, 21.1%. However, the results of more refined analysis suggest that the enhanced bid premium is in fact driven by independent boards comprising non‐executive directors who have reputation capital at stake. We also find that independent boards that resist takeovers or include voluntary independent expert reports in target statements, increase the bid premium revision by, on average, 15.6% and 16.2%, respectively.
Effects of Employee Support on Junior Accountants' Job Attitudes and Intention to Quit
Authors: Chan Christopher C.A. , Monroe Gary S. , Ng Juliana , Tan Rebecca Chyi Woan
Published: July 2008

This study examines the effects of four types of employee support on a sample of 231 junior accountants' organisational commitment, job involvement and intention to quit. The four types of support include organisational, supervisory, psycho‐social and career development support. Results of path analysis suggest that only organisational support and psycho‐social support influence organisational commitment which, in turn, increases job involvement and reduces intention to quit.
Disclosure of Financial Commitments
Authors: Walker R.G.
Published: July 2008

A casualty of the transfer of disclosure rules from regulations to the Corporations Law to Australian Accounting Standards (and the later harmonisation of disclosure requirements with IFRS) has been the loss of a rule that required disclosure of off‐balance sheet financial commitments and details of when those commitments would fall due.
Activation of B‐Myb by E2F1 in hepatocellular carcinoma
Authors: Nakajima Tomoaki , Yasui Kohichiroh , Zen Keika , Inagaki Yoshikazu , Fujii Hideki , Minami Masahito , Tanaka Shinji , Taniwaki Masafumi , Itoh Yoshito , Arii Shigeki , Inazawa Johji , Okanoue Takeshi
Published: July 2008

Aim:  Deregulation of E2F1 transcriptional activity is observed in a variety of cancers, including hepatocellular carcinoma (HCC). The aim of the present study is to identify transcriptional target genes of E2F1 in HCC.

Methods:  We determined expression levels for E2F1 and ten candidate genes thought to be targets of E2F1 in primary HCCs using a real‐time quantitative reverse transcription‐PCR assay. Following small interfering RNA (siRNA)‐mediated knockdown of E2F1 in HCC cell lines, we quantified mRNA levels of the candidate E2F1 target genes.

Results:  E2F1 was significantly over‐expressed in 41 primary HCCs as compared to non‐tumorous liver tissues. Among the candidates, MYBL2, whose product is the transcriptional factor B‐Myb, which is involved in controlling cell‐cycle progression and apoptosis, was significantly over‐expressed in primary HCCs. Additionally, expression levels of MYBL2 correlated with those of E2F1. Knockdown of E2F1 resulted in a decrease in expression of MYBL2. A copy‐number gain for MYBL2 was observed in 36 of 66 primary HCCs, suggesting that MYBL2 expression is up‐regulated by amplification in addition to being regulated by E2F1. Moreover, siRNA‐mediated knockdown of MYBL2 led to reduced expression of CDC2 (which encodes CDC2), cyclin A2 (CCNA2), and topoisomerase II α (TOP2A), implicating these genes in the cell cycle and suggesting that they may be downstream targets of B‐Myb.

Conclusion:  MYBL2 is a probable transcriptional target of E2F1 in HCC and may therefore be a useful biomarker for diagnosis and an attractive target for molecular therapies useful to treat HCC.
Deficiency of forkhead box P3 and cytotoxic T‐lymphocyte‐associated antigen‐4 gene expressions and impaired suppressor function of CD4+CD25+ T cells in patients with autoimmune hepatitis
Authors: Okumura Akihiko , Ishikawa Tetsuya , Sato Sayaka , Yamauchi Taeko , Oshima Hisae , Ohashi Tomohiko , Sato Ken , Ayada Minoru , Hotta Naoki , Kakumu Shinichi
Published: July 2008

Aim:  Recently, forkhead box P3 (Foxp3), cytotoxic T‐lymphocyte‐associated antigen‐4 (CTLA‐4), glucocorticoid‐induced tumor necrosis factor receptor family‐related gene (GITR), and CD28 were identified as the key molecules that control the development and activation of CD4+CD25+ regulatory T cells (T‐reg). We investigated the expression pattern of these molecules on T‐reg, and investigated the ability of T‐reg to produce cytokines in patients with autoimmune hepatitis (AIH).

Methods:  Fifteen patients with AIH and nine healthy patients were included. To determine the frequency of T‐reg, a two‐color flow cytometry analysis was performed. T‐reg were isolated using immunomagnetic beads, and the mRNA levels of Foxp3, CTLA‐4, GITR, and CD28 were quantified by real‐time polymerase chain reaction (PCR). The ability of T‐reg to produce interferon‐γ, interleukin (IL)‐10, transforming growth factor‐β, and tumor necrosis factor‐α after stimulation by OKT3 was evaluated by measuring the levels of mRNA in T‐reg by real‐time PCR.

Results:  The frequency of T‐reg was increased in AIH. The mRNA levels of Foxp3 and CTLA‐4 were significantly lower in AIH. The ability of T‐reg to produce IL‐10 was impaired in AIH.

Conclusion:  We speculate that the inferiority of the Foxp3 and CTLA‐4 gene expressions on T‐reg results in the impaired suppressor function of T‐reg, and eventually in the breakdown of self‐tolerance.
Griseofulvin, an oral antifungal agent, suppresses hepatitis C virus replication in vitro
Authors: Jin Haofan , Yamashita Atsuya , Maekawa Shinya , Yang Pinting , He Limin , Takayanagi Satoru , Wakita Takaji , Sakamoto Naoya , Enomoto Nobuyuki , Ito Masahiko
Published: July 2008

Aim:  Hepatitis C virus (HCV), which infects an estimated 170 million people worldwide, is a major cause of chronic liver disease. The current standard therapy for chronic hepatitis C is based on pegylated interferon (IFN)α in combination with ribavirin. However, the success rate remains at approximately 50%. Therefore, alternative agents are needed for the treatment of HCV infection.

Methods:  Using an HCV‐1b subgenomic replicon cell culture system (Huh7/Rep‐Feo), we found that griseofulvin, an oral antifungal agent, suppressed HCV‐RNA replication and protein expression in a dose‐dependent manner. We also found that griseofulvin suppressed the replication of infectious HCV JFH‐1. A combination of IFNα and griseofulvin exhibited a synergistic inhibitory effect in Huh7/Rep‐Feo cells.

Results:  We found that griseofulvin blocked the cell cycle at the G2/M phase in the HCV subgenomic replicon cells, but did not inhibit HCV internal ribosome entry site‐dependent translation.

Conclusion:  Our results suggest that griseofulvin may represent a new approach to the development of a novel therapy for HCV infection.
Up‐regulation of breast cancer resistance protein expression in hepatoblastoma following chemotherapy: A study in patients and in vitro
Authors: Vander Borght Sara , Van Pelt Jos , Van Malenstein Hannah , Cassiman David , Renard Marleen , Verslype Chris , Libbrecht Louis , Roskams Tania A.
Published: July 2008

Aim:  Hepatoblastoma (HB), the most common pediatric malignant liver tumor, is treated with chemotherapy to facilitate surgical resection. Previous studies suggest that HB acquires chemoresistance via increased expression of multidrug resistance protein 1 (MDR1, ABCC1). There is no well established evidence that this also occurs in the clinical setting and little is known about the effects of chemotherapeutic treatments on HB in situ.

Methods:  Clinical and histopathological features and expression patterns of ABC transporters in diagnostic needle biopsies from 7 HBs taken before chemotherapy were compared with those in surgically resected tumors. To understand the mechanisms leading to chemoresistance we also investigated the involvement of hypoxia on protein expression and functional activity of drug transporters (BCRP and MDR1) in cultures of HepG2 human HB cells.

Results:  We found that chemotherapeutical treatment of HBs led to an increased expression of the breast cancer resistance protein (BCRP, ABCG2) in all patients studied. There was no change in the expression pattern of MDR1 or other ABC transporters. Chemotherapy‐induced specific vascular abnormalities associated with areas of necrosis and fibrosis were seen in all cases, suggesting tumor hypoxia. The observations of increased BCRP expression in hypoxic areas of three‐dimensional HepG2 aggregates and the enhanced BCRP function in monolayer cultures of HepG2 cells under hypoxic conditions, support a role for hypoxia in enhanced BCRP expression.

Conclusions:  Chemotherapeutical treatment of HB leads to vascular alterations that modify the tumor microenvironment, and increased BCRP expression in which hypoxia might play a role. No evidence was found for upregulation of MDR1 in HBs as suggested from previous experimental studies.
Transient elastography: Applications and limitations
Authors: Yoshioka Kentaro , Kawabe Naoto , Hashimoto Senju
Published: July 2008

Transient elastgraphy with use of FibroScan is one of most accurate methods for assessment of liver fibrosis. FibroScan can be readily used with an operator with a short training. In many different studies, liver stiffness measured by transient elastgraphy correlates well with fibrosis stages, and cutoff values of liver stiffness for fibrosis staging are similar even among different diseases. However there is wide variation of stiffness values in the same fibrosis stage, and some overlap between the adjacent stages. In addition, inflammatory activity and size of nodule of cirrhosis affect the liver stiffness values. The reproducibility may be reduced by age, obesity, steatosis, narrow intercostal space and lower degrees of hepatic fibrosis in patients. Thus the estimation of fibrosis stages from liver stiffness should be cautiously done. To improve the accuracy of liver fibrosis staging, the combination of transient elastography with other noninvasive methods such as FibroTest should be required.
Occult hepatitis B virus infection in HIV‐infected patients: Evaluation of biochemical, virological and molecular parameters
Authors: Araujo Natalia M. , Branco‐Vieira Monique , Silva Anita C.M. , Pilotto José H. , Grinsztejn Beatriz , De Almeida Adilson José , Trepo Christian , Gomes Selma A.
Published: July 2008

Aim:  To determine the prevalence of occult hepatitis B virus (HBV) infection in a group of human immunodeficiency virus (HIV)‐infected Brazilian patients and to investigate its association with biochemical, virological and molecular features.

Methods:  Sera from 43 patients positive for HBV core antibody and negative for HBV surface antigen (HBsAg) were tested for HBV DNA positivity by semi‐nested PCR. HBV loads were assessed by real‐time PCR. S gene was cloned and sequenced for HBV isolates from 3 patients. HBsAg expression of these cases was performed in HuH7 cells.

Results:  HBV DNA was found in 6/43 (14%) samples, all except one associated with low viral loads. Occult HBV infection was further correlated with anti‐hepatitis C virus (anti‐HCV) antibodies positivity, but not with alanine aminotransferase (ALT) elevated levels. S gene sequences derived from three patients were determined. Two of them displayed mutations that may explain HBsAg negativity. In the first one, a stop codon mutation was found at position 216 in the C‐terminal end of HBsAg. In the second patient, E164D and I195M substitutions in HBsAg, associated with lamivudine‐resistance mutations in the polymerase were identified. As expected, all clones showing those mutations displayed undetectable or very low levels of HBsAg.

Conclusion:  Occult HBV infection was frequent in HIV‐infected patients, was not associated with ALT elevation but significantly correlated with HCV seropositivity. The low viremia and the detection of HBsAg mutants confirm that multifactorial mechanisms are involved in occult HBV infection. HBV molecular monitoring should be employed for an adequate management of HBV/HIV co‐infected patients.
Antioxidant treatment with N‐acetylcysteine regulates mammalian skeletal muscle Na+–K+‐ATPase α gene expression during repeated contractions
Authors: Murphy K. T. , Medved I. , Brown M. J. , Cameron‐Smith D. , McKenna M. J.
Published: July 2008

Exercise increases Na+–K+ pump isoform gene expression and elevates muscle reactive oxygen species (ROS). We investigated whether enhanced ROS scavenging induced with the antioxidant N‐acetylcysteine (NAC) blunted the increase in Na+–K+ pump mRNA during repeated contractions in human and rat muscle. In experiment 1, well‐trained subjects received saline or NAC intravenously prior to and during 45 min cycling. Vastus lateralis muscle biopsies were taken pre‐infusion and following exercise. In experiment 2, isolated rat extensor digitorum longus muscles were pre‐incubated without or with 10 mm NAC and then rested or stimulated electrically at 60 Hz for 90 s. After 3 h recovery, muscles were frozen. In both experiments, the muscles were analysed for Na+–K+ pump α1, α2, α3, β1, β2 and β3 mRNA. In experiment 1, exercise increased α2 mRNA by 1.0‐fold (P= 0.03), but α2 mRNA was reduced by 0.40‐fold with NAC (P= 0.03). Exercise increased α3, β1 and β2 mRNA by 2.0‐ to 3.4‐fold (P < 0.05), but these were not affected by NAC (P > 0.32). Neither exercise nor NAC altered α1 or β3 mRNA (P > 0.31). In experiment 2, electrical stimulation increased α1, α2 and α3 mRNA by 2.3‐ to 17.4‐fold (P < 0.05), but these changes were abolished by NAC (P > 0.07). Electrical stimulation almost completely reduced β1 mRNA but only in the presence of NAC (P < 0.01). Neither electrical stimulation nor NAC altered β2 or β3 mRNA (P > 0.09). In conclusion, NAC attenuated the increase in Na+–K+ pump α2 mRNA with exercise in human muscle and all α isoforms with electrical stimulation in rat muscle. This indicates a regulatory role for ROS in Na+–K+ pump α isoform mRNA in mammalian muscle during repeated contractions.
Effect of botulinum toxin A‐induced paralysis and exercise training on mechanosensing and signalling gene expression in juvenile rat gastrocnemius muscle
Authors: Velders Martina , Legerlotz Kirsten , Falconer Shelley J. , Stott N. Susan , McMahon Christopher D. , Smith Heather K.
Published: July 2008

Intramuscular injections of the paralytic botulinum neurotoxin A (Btx) and physical exercise are used in the treatment of chronic spasticity in children with cerebral palsy. We tested whether Btx‐induced paralysis and/or exercise training would have differential effects on the expression of mechanosensing and signalling genes implicated in the adaptive remodelling of skeletal muscle. Juvenile (29‐day‐old) male rats were injected with Btx or saline (NoBtx) into the right gastrocnemius and housed in standard cages (NoEx) or with running wheels (Ex), for 3 weeks (n= 6 per group). The mRNA expression of nine sarcomere‐associated genes in the medial gastrocnemius was then determined by quantitative reverse transcriptase‐polymerase chain reaction. The Btx‐injected muscles weighed 50% less than NoBtx muscles, but Ex had no effect on the wet mass of Btx or NoBtx muscles. Atrogenic MuRF1, sarcomeric Titin and myogenic MyoD were upregulated (2‐fold) with the elimination of contractile activity in Btx muscle. Expression of CARP, Ankrd2 and MLP was increased with mechanical stimuli associated with Btx (5‐ to 10‐fold) or Ex (2‐ to 4‐fold). Expression of CARP and Ankrd2 increased synergistically in Btx–Ex muscle (≥20‐fold), indicating that these genes may be sensitive to passive stretch of the sarcomeric I‐band region of titin to which their proteins bind. Tcap, Myopalladin and Atrogin1 were not, or were no longer responsive to the altered mechanical stimuli after 3 weeks of Btx or Ex. The expression of Ankrd2, CARP and MLP may thus be enhanced by passive stretch within the Btx‐paralysed and/or exercising gastrocnemius and contribute to adaptations, other than muscle mass, in juvenile rats.
Sorcin modulates cardiac L‐type Ca2+ current by functional interaction with the α1C subunit in rabbits
Authors: Fowler Mark R. , Colotti Gianni , Chiancone Emilia , Smith Godfrey L. , Fearon Ian M.
Published: July 2008

We examined the modulation of the cardiac L‐type Ca2+ channel (LTCC) by the regulatory protein sorcin and tested the hypothesis that modulation occurred by direct interaction. Whole‐cell patch‐clamp recordings were made on native rabbit ventricular myocytes and HEK 293 cells expressing cardiac α1C subunits. In ventricular cells, sorcin increased peak current when using either Ca2+ or Ba2+ as charge carriers. In HEK 293 cells, sorcin increased peak current density when using Ba2+ as a charge carrier but not when using Ca2+. In ventricular myocytes, current inactivation (τfast, in ms) was slowed by sorcin with Ca2+ as the charge carrier, whilst in the presence of Ba2+ it was enhanced. In HEK 293 cells, sorcin significantly enhanced τfast, but no significant change was observed with Ba2+. This trend was mimicked by the truncated peptide, sorcin Ca2+‐binding domain, which lacks the N‐terminal domain. These data suggest that sorcin interacts with LTCC via its C‐terminal domain, which alters current magnitude and τfast. These effects appear to be influenced by the prevailing experimental conditions.
Infection with respiratory syncytial virus alters peptidergic innervation in the lower airways of guinea‐pigs
Authors: Tan Yurong , Yang Tao , Liu Shuiping , Liu Huijun , Xiang Yang , Qu Fei , Li Hongtao , Qin Xiaoqun
Published: July 2008

To probe the mechanisms by which respiratory syncytial virus (RSV) infection in early life forms an important risk factor for the development of chronic asthma, an airway hyper‐responsiveness (AHR) animal model of guinea‐pigs with persistent RSV infection was established by intranasal instillation of 2 × 105 plaque‐forming units RSV. On days 0, 7, 28, 42 and 60 postinoculation, the RSV copy numbers, airway function and peptidergic innervation were measured in the peripheral airways. The results showed that the virus was persistent in the lungs. During persistent infection (days 42 and 60), the lung resistance and the total cells, neutrophils and eosinophils of infected guinea‐pigs increased significantly; the airway showed signs of chronic inflammation; and the substance P‐ and calcitonin gene‐related peptide‐positive fibres increased, but vasoactive intestinal polypeptide‐positive fibres decreased. These results suggest that persistent RSV infection can cause long‐term chronic airway inflammation and persistent airway neural network abnormality, which may be related to the occurrence of AHR.
Role of the commissural inhibitory system in vestibular compensation in the rat
Authors: Bergquist Filip , Ludwig Mike , Dutia Mayank B.
Published: July 2008

We investigated the role of the vestibular commissural inhibitory system in vestibular compensation (VC, the behavioural recovery that follows unilateral vestibular loss), using in vivo microdialysis to measure GABA levels in the bilateral medial vestibular nucleus (MVN) at various times after unilateral labyrinthectomy (UL). Immediately after UL, in close correlation with the appearance of the characteristic oculomotor and postural symptoms, there is a marked increase in GABA release in the ipsi‐lesional MVN. This is not prevented by bilateral flocculectomy, indicating that it is due to hyperactivity of vestibular commissural inhibitory neurones. Over the following 96 h, as VC occurs and the behavioural symptoms ameliorate, the ipsi‐lesional GABA levels return to near‐normal. Contra‐lesional GABA levels do not change significantly in the initial stages of VC, but decrease at late stages so that when static symptoms have abated there remains a significant difference between the MVNs of the two sides. We also investigated the role of the commissural inhibition in Bechterew's phenomenon, by reversibly inactivating the intact contra‐lesional labyrinth in compensating animals through superfusion of local anaesthetic on the round window. Transient inactivation of the intact labyrinth elicited the lateralized behaviour described by Bechterew, but did not alter the GABA levels in either MVN, suggesting the involvement of distinct cellular mechanisms. These findings indicate that an imbalanced commissural inhibitory system is a root cause of the severe oculomotor and postural symptoms of unilateral vestibular loss, and that re‐balancing of commissural inhibition occurs in parallel with the subsequent behavioural recovery during VC.
Elevation in cerebral blood flow velocity with aerobic fitness throughout healthy human ageing
Authors: Ainslie Philip N. , Cotter James D. , George Keith P. , Lucas Sam , Murrell Carissa , Shave Rob , Thomas Kate N. , Williams Michael J. A. , Atkinson Greg
Published: July 2008

It is known that cerebral blood flow declines with age in sedentary adults, although previous studies have involved small sample sizes, making the exact estimate of decline imprecise and the effects of possible moderator variables unknown. Animal studies indicate that aerobic exercise can elevate cerebral blood flow; however, this possibility has not been examined in humans. We examined how regular aerobic exercise affects the age‐related decline in blood flow velocity in the middle cerebral artery (MCAv) in healthy humans. Maximal oxygen consumption, body mass index (BMI), blood pressure and MCAv were measured in healthy sedentary (n= 153) and endurance‐trained (n= 154) men aged between 18 and 79 years. The relationships between age, training status, BMI and MCAv were examined using analysis of covariance methods. Mean ±s.e.m. estimates of regression coefficients and 95% confidence intervals (95% CI) were calculated. The age‐related decline in MCAv was −0.76 ± 0.04 cm s−1 year−1 (95% CI =−0.69 to −0.83, r2= 0.66, P < 0.0005) and was independent of training status (P= 0.65). Nevertheless, MCAv was consistently elevated by 9.1 ± 3.3 cm s−1 (CI = 2.7–15.6, P= 0.006) in endurance‐trained men throughout the age range. This ∼17% difference between trained and sedentary men amounted to an approximate 10 year reduction in MCAv ‘age’ and was robust to between‐group differences in BMI and blood pressure. Regular aerobic‐endurance exercise is associated with higher MCAv in men aged 18–79 years. The persistence of this finding in older endurance‐trained men may therefore help explain why there is a lower risk of cerebrovascular disease in this population.
Plant Immunity Requires Conformational Charges of NPR1 via S-Nitrosylation and Thioredoxins
Authors: Tada Yasuomi , Spoel Steven H. , Pajerowska-Mukhtar Karolina , Mou Zhonglin , Song Junqi , Wang Chun , Zuo Jianru , Dong Xinnian
Published: July 2008

Changes in redox status have been observed during immune responses in different organisms, but the associated signaling mechanisms are poorly understood. In plants, these redox changes regulate the conformation of NPR1, a master regulator of salicylic acid (SA)–mediated defense genes. NPR1 is sequestered in the cytoplasm as an oligomer through intermolecular disulfide bonds. We report that S-nitrosylation of NPR1 by
S-
nitrosoglutathione (GSNO) at cysteine-156 facilitates its oligomerization, which maintains protein homeostasis upon SA induction. Conversely, the SA-induced NPR1 oligomer-to-monomer reaction is catalyzed by thioredoxins (TRXs). Mutations in both NPR1 cysteine-156 and TRX compromised NPR1-mediated disease resistance. Thus, the regulation of NPR1 is through the opposing action of GSNO and TRX. These findings suggest a link between pathogen-triggered redox changes and gene regulation in plant immunity.
Differences and similarities between arrhythmogenic right ventricular cardiomyopathy and athlete’s heart adaptations
Authors: Bauce B , Frigo G , Benini G , Michieli P , Basso C , Folino A F , Rigato I , Mazzotti E , Daliento L , Thiene G , Nava A
Published: July 2008

Background

Regular intensive physical activity is associated with non-pathological changes in cardiac morphology. Differential diagnosis with arrhythmogenic right ventricular cardiomyopathy (ARVC) constitutes a frequent problem, especially in athletes showing ventricular arrhythmias with left bundle branch block morphology.

Aim of the study

To assess the different clinical and non-invasive instrumental features of the subjects affected by ARVC and by athletes.

Methods

Three groups of subjects (40 ARVC patients, 40 athletes and 40 controls, mean age 27 (9) years) were examined with family and personal history, physical examination, 12-lead ECG, 24-h ECG, signal-averaged ECG and 2-D and Doppler echocardiography.

Results

12-Lead ECG was abnormal in 62% of ARVC patients versus 7.5% of athletes and 2.5% of controls (p<0.0001). Ventricular arrhythmias and late potentials were present in 70% and 55% of ARVC subjects, respectively (vs 5% of athletes and 7.5% of controls, p<0.0001). Left ventricular parietal wall thickness and left ventricular end-diastolic diameters were significantly higher in athletes. Both athletes and ARVC patients presented a right ventricular (RV) enlargement compared with controls. Moreover, RV outflow tract, measured on parasternal long axis and at the level of aortic root, was significantly larger in ARVC patients (33.6 (4.7) mm vs 29.1 (3.4) mm and 35.6 (6.8) mm vs 30.1 (2.9) mm; p<0.0001), and RV fractional shortening and ejection fraction were significantly lower in ARVC patients compared with athletes (40 (7.9)% vs 44 (10)%; p=0.05 and 52.9 (8)% vs 59.9 (4.5)%; p<0.0001). A thickened moderator band was found to be present in similar percentage in ARVC patients and athletes.

Conclusions

An accurate clinical and instrumental non-invasive evaluation including echocardiography as imaging technique allows to distinguish RV alterations typical of ARVC from those detected in athletes as a consequence of intensive physical activity.
Catastrophic injuries in the Olympic styles of wrestling in Iran
Authors: Kordi R , Akbarnejad A , Wallace W A
Published: July 2008

Objectives

In this study, a profile of direct catastrophic injuries in international styles of wrestling was developed, and the possible risk factors were described.

Design

Survey and retrospective review.

Setting

Catastrophic injuries that occurred in wrestling clubs in Iran from July 1998 to June 2005 were identified by contacting several sources. The cases were retrospectively reviewed.

Results

The injuries included were 29 direct injuries (12 fatalities, 11 non-fatal and 6 serious).The injury rate was 1.99 direct catastrophic injuries/100 000 wrestlers/year. The majority of direct injuries occurred during training sessions, with a trend towards more injuries in the lowweight and middle-weight classes and those who were competing at high performance and experience levels. The takedown position, especially for the attacking wrestler who faces a counterattack, was the most common activity at the time of injury. A list of risk factors was suggested, of which “performing the wrestling manoeuvre incorrectly”, “inappropriate management of the injury”, “lack of the coach supervision”, “mat problems” and “lack of restraining the wrestlers in a precarious position” were the most common risk factors.

Conclusions

Catastrophic wrestling injuries are rare and preventable. Coaches have an essential role in the prevention of these injuries.
Sports hernias: a systematic literature review
Authors: Caudill P , Nyland J , Smith C , Yerasimides J , Lach J
Published: July 2008

This review summarises the existing knowledge about pathogenesis, differential diagnosis, conservative treatment, surgery and post-surgical rehabilitation of sports hernias. Sports hernias occur more often in men, usually during athletic activities that involve cutting, pivoting, kicking and sharp turns, such as those that occur during soccer, ice hockey or football. Sports hernias generally present an insidious onset, but with focused questioning a specific inciting incident may be identified. The likely causative factor is posterior inguinal wall weakening from excessive or high repetition shear forces applied through the pelvic attachments of poorly balanced hip adductor and abdominal muscle activation. There is currently no consensus as to what specifically constitutes this diagnosis. As it can be difficult to make a definitive diagnosis based on conventional physical examination, other methods, such as MRI and diagnostic ultrasonography are often used, primarily to exclude other conditions. Surgery seems to be more effective than conservative treatment, and laparoscopic techniques generally enable a quicker recovery time than open repair. However, in addition to better descriptions of surgical anatomy and procedures and conservative and post-surgical rehabilitation, well-designed research studies are needed, which include more detailed serial patient outcome measurements in addition to basing success solely on return to sports activity timing. Only with this information will we better understand sports hernia pathogenesis, verify superior surgical approaches, develop evidence-based screening and prevention strategies, and more effectively direct both conservative and post-surgical rehabilitation.
Subjective and objective measures of physical activity in relationship to bone mineral content during late childhood: the Iowa Bone Development Study
Authors: Janz K F , Medema-Johnson H C , Letuchy E M , Burns T L , Gilmore J M Eichenberger , Torner J C , Willing M , Levy S M
Published: July 2008

Objective:

This study compared accelerometry to self-report for the assessment of physical activity (PA) in relation to bone mineral content (BMC). In addition, we compared the ability of these measures to assess PA in boys versus girls.

Methods:

Participants in this cross-sectional study included 449 children (mean age 11 years) from the Iowa Bone Development Study. PA was measured via 3–5 days of accelerometry using the Actigraph and 7 day self-report questionnaire using the Physical Activity Questionnaire for Children (PAQ-C). Hip, spine, and whole body BMC were measured via dual energyxray absorptiometry (DXA).

Results:

Partial correlation analysis (controlling for height, weight, and maturity) showed the Actigraph was significantly associated with hip (r = 0.40), spine (r = 0.20), and whole body (r = 0.33) BMC in boys, as was the PAQ-C (r = 0.28 hip, r = 0.19 spine, and r = 0.22 whole body). Among girls, only the Actigraph was significantly associated with hip (r = 0.18) and whole body (r = 0.16) BMC. Both the Actigraph and PAQ-C were significant in hip, spine, and whole body multivariable linear regression models (after controlling for body size and maturity) in boys. Only the Actigraph entered hip BMC regression model in girls.

Conclusions:

Our study supports previous work showing associations between everyday PA and BMC in older children. These associations are more likely to be detected with an objective versus subjective measure of PA, particularly in girls.
External auditory canal exostoses in white water kayakers
Authors: Cooper A , Tong R , Neil R , Owens D , Tomkinson A
Published: July 2008

Objective

In this study, the presence and severity of external auditory canal exostoses (EACE) in a group of white water kayakers related to the duration and intensity of kayaking and the number of ear infections reported were identified.

Design

A community-based volunteer cross-sectional study was completed with 92 kayakers (69 men, 23 women; mean (SD) age 29.3 (8.72) years) and 65 control volunteers (37 men, 28 women; mean (SD) age 36.9 (14.9) years). After exclusions, 269 individual ears were examined (154 kayakers and 115 controls). Participants completed a questionnaire and underwent otoscopic examination. Main outcome measures were the presence and severity of EACE, the duration and frequency of kayaking and self-reported ear infections. Exclusion criteria included other cold-water exposure, known ear pathology or poor visualisation of the auditory canal.

Results

The findings demonstrated that 69.5% of kayaker ears and 1.7% of the control group were found to have EACE. Severity of EACE was significantly associated with the duration (p<0.01) and frequency (p<0.05) of kayaking with 90.6% of kayakers that had participated for more than 10 years having evidence of EACE. A significant relationship also existed between the number of self-reported ear infections and the severity of EACE (p<0.01).

Conclusion

There is a positive relationship between the duration and frequency of white water kayaking and the presence and severity of EACE and associated ear infections.
Injuries and musculoskeletal complaints in referees and assistant referees selected for the 2006 FIFA World Cup: retrospective and prospective survey
Authors: Bizzini M , Junge A , Bahr R , Helsen W , Dvorak J
Published: July 2008

Background:

There is a considerable amount of scientific literature on football, but few studies have focused on referees, despite their key role in this sport. Existing studies focus on the physiological demands and training of referees.

Purpose:

To analyse injuries and musculoskeletal complaints in referees and assistant referees selected for the 2006 FIFA World Cup.

Study design:

Retrospective survey and prospective study.

Methods:

During the preparation camps for the 2006 FIFA World Cup in Germany, all 123 referees pre-selected for the tournament completed a questionnaire on injuries and musculoskeletal complaints. During the tournament, the characteristics and consequences of all injuries and complaints incurred by the 63 officiating referees were documented.

Results:

More than 40% of the referees reported having incurred an injury and more than 60% having had musculoskeletal complaints during their career. About 20% of the group reported having suffered from musculoskeletal complaints in the last match. During the World Cup, 14 referees (22%) incurred an injury and more than 30% had musculoskeletal complaints. This prospectively collected data showed an incidence of 20.8 injuries per 1000 match hours (95% CI: 4.17 to 37.4). The most common acute injuries were hamstring strains, calf strains, and ankle sprains, while the most frequent locations of complaints were the low back, hamstring and knee.

Conclusion:

Considering the injury profile, the prevalence of associated musculoskeletal complaints, and the high physiological demands of refereeing, it appears that injury prevention programmes should be developed and integrated into the fitness training routine of the referee.
Frontal and lateral characteristics of the osseous configuration in chronic ankle instability
Authors: Magerkurth O , Frigg A , Hintermann B , Dick W , Valderrabano V
Published: July 2008

Objective

The osseous ankle configuration (tibiotalar sector, talar radius and height) has been discovered as intrinsic risk factor for chronic ankle instability (CAI). These measurements were done on lateral radiographs only. In this study, the osseous characteristics in the frontal plane and further lateral values were measured.

Design

Level III case-control study.

Setting

Radiological measurement of frontal and lateral radiographs by one independent, blinded radiologist using a digital DICOM/PACS system.

Patients

A group of 52 patients with CAI was compared with an age- and sex-matched control group of 52 healthy subjects.

Main outcome measurements

In the frontal plane, the depth of the talar curvature (frontal curvature (froCu)) and the lateral and medial malleolar lengths were measured. In the lateral plane, the position of the centre of rotation to the tibial axis (talar centre of rotation to the anatomical axis of the tibia (TibCOR)) and the tibial lateral surface angle (TLS) were also measured.

Results

The froCu was deeper in patients with CAI (1.8 (0.5) mm) than in healthy subjects (1.0 (0.5) mm, p<0.05). The TibCOR was more anterior in patients with CAI (2.5 (1.9) mm) than in healthy subjects (1.6 (2.2) mm, p<0.05). The distance from the fibular tip to the centre of rotation was smaller in patients with CAI (3.5 (3.4) mm) than in healthy subjects (6.5 (3.3) mm, p<0.05). The TLS and the length of the lateral and medial ankle were not significantly different.

Conclusions

This study supports that the osseous joint configuration is an intrinsic risk factor for CAI. It could be shown that CAI is characterised by a deeper frontal curvature of the talus and a more anterior position of the talus to the tibia.