bluuebunny/crossref_metadata_2025 huggingface dataset:
Modified Lipooligosaccharide Structure Protects Nontypeable Haemophilus influenzae from IgM-Mediated Complement Killing in Experimental Otitis Media
Authors: Langereis Jeroen D. , Stol Kim , Schweda Elke K. , Twelkmeyer Brigitte , Bootsma Hester J. , de Vries Stefan P. W. , Burghout Peter , Diavatopoulos Dimitri A. , Hermans Peter W. M.
Published: July 2012

Nontypeable
Haemophilus influenzae
(NTHi) is a Gram-negative, human-restricted pathogen. Although this bacterium typically colonizes the nasopharynx in the absence of clinical symptoms, it is also one of the major pathogens causing otitis media (OM) in children. Complement represents an important aspect of the host defense against NTHi. In general, NTHi is efficiently killed by complement-mediated killing; however, various resistance mechanisms have also evolved. We measured the complement resistance of NTHi isolates isolated from the nasopharynx and the middle ear fluids of OM patients. Furthermore, we determined the molecular mechanism of NTHi complement resistance. Complement resistance was strongly increased in isolates from the middle ear, which correlated with decreased binding of IgM. We identified a crucial role for the R2866_0112 gene in complement resistance. Deletion of this gene altered the lipooligosaccharide (LOS) composition of the bacterium, which increased IgM binding and complement-mediated lysis. In a novel mouse model of coinfection with influenza virus, we demonstrate decreased virulence for the R2866_0112 deletion mutant. These findings identify a mechanism by which NTHi modifies its LOS structure to prevent recognition by IgM and activation of complement. Importantly, this mechanism plays a crucial role in the ability of NTHi to cause OM.

IMPORTANCE
Nontypeable
Haemophilus influenzae
(NTHi) colonizes the nasopharynx of especially young children without any obvious symptoms. However, NTHi is also a major pathogen in otitis media (OM), one of the most common childhood infections. Although this pathogen is often associated with OM, the mechanism by which this bacterium is able to cause OM is largely unknown. Our study addresses a key biological question that is highly relevant for child health: what is the molecular mechanism that enables NTHi to cause OM? We show that isolates collected from the middle ear fluid exhibit increased complement resistance and that the lipooligosaccharide (LOS) structure determines IgM binding and complement activation. Modification of the LOS structure decreased NTHi virulence in a novel NTHi-influenza A virus coinfection OM mouse model. Our findings may also have important implications for other Gram-negative pathogens harboring LOS, such as
Neisseria meningitidis
,
Moraxella catarrhalis
, and
Bordetella pertussis
.
External Validity in Randomised Controlled Trials of Acupuncture for Osteoarthritis Knee Pain
Authors: Purepong Nithima , Jitvimonrat Anusorn , Sitthipornvorakul Ekalak , Eksakulkla Sukanya , Janwantanakul Prawit
Published: July 2012

Objectives

To assess two aspects of the external validity of acupuncture research for osteoarthritis knee pain and determine the common acupoints and treatment parameters used.

Methods

The external validity of 16 randomised controlled trials (RCTs) was investigated using a scale consisting of two aspects: reporting and performance. The reporting aspect included acupuncturist's background, study location, treatment detailed, patient characteristics, positive trial results, adverse effects and between-group statistical differences, whereas treatment appropriateness, appropriate controls and outcomes were classified as the performance aspect. Acupuncture treatment in RCTs was compared with common practice according to the literature sources and survey of acupuncturists working in different parts of Thailand.

Results

The levels of external validity for the reporting and performance aspects were in the range of 31.3% to 100%. Statistic values such as mean difference and confidence interval were reported by the minority of trials (43.8%). Patient satisfaction and quality of life were seldom used (31.3%). There were minor differences between research and practice in terms of the points used (25.0%), number of treatment sessions (6.3%) and frequency (12.5%). The most frequently used points were ST34, ST35, ST36, SP6, SP9, SP10, GB34, Xiyan and ah shi points, and the commonly used treatment parameters were 20 minutes, 10–15 sessions and two treatments weekly.

Conclusions

Reporting of the external validity of acupuncture RCTs for knee pain was notably inadequate in terms of trial setting, treatment provider and statistical reporting. The majority of studies involved appropriate controls and outcomes and applied acupuncture treatments in line with practice.
A descriptive analysis of notifiable gastrointestinal illness in the Northwest Territories, Canada, 1991–2008
Authors: Pardhan-Ali Aliya , Wilson Jeff , Edge Victoria L , Furgal Chris , Reid-Smith Richard , Santos Maria , McEwen Scott A
Published: July 2012

Objectives

To describe the major characteristics of reported notifiable gastrointestinal illness (NGI) data in the Northwest Territories (NWT) from January 1991 through December 2008.

Design

Descriptive analysis of 708 reported cases of NGI extracted from the Northwest Territories Communicable Disease Registry (NWT CDR).

Setting

Primary, secondary and tertiary health care centres across all 33 communities of the NWT.

Population

NWT residents of all ages with confirmed NGI reported to the NWT CDR from January 1991 through December 2008.

Main outcome measure

Laboratory-confirmed NGI, with a particular emphasis on campylobacteriosis, giardiasis and salmonellosis.

Results

Campylobacteriosis, giardiasis and salmonellosis were the most commonly identified types of NGI in the territory. Seasonal peaks for all three diseases were observed in late summer to autumn (p<0.01). Higher rates of NGI (all 15 diseases/infections) were found in the 0–9-year age group and in men (p<0.01). Similarly, rates of giardiasis were higher in the 0–9-year age group and in men (p<0.02). A disproportionate burden of salmonellosis was found in people aged 60 years and older and in women (p<0.02). Although not significant, the incidence of campylobacteriosis was greater in the 20–29-years age group and in men (p<0.07). The health authority with the highest incidence of NGI was Yellowknife (p<0.01), while for salmonellosis and campylobacteriosis, it was Tlicho (p<0.01) and for giardiasis, the Sahtu region (p<0.01). Overall, disease rates were higher in urban areas (p<0.01). Contaminated eggs, poultry and untreated water were believed by health practitioners to be important sources of infection in cases of salmonellosis, campylobacteriosis and giardiasis, respectively.

Conclusions

The general patterns of these findings suggest that environmental and behavioural risk factors played key roles in infection. Further research into potential individual and community-level risk factors is warranted.
Patient self-assessment of hospital pain, mood and health-related quality of life in adults with sickle cell disease
Authors: Anie Kofi A , Grocott Hannah , White Lauren , Dzingina Mendwas , Rogers Gabriel , Cho Gavin
Published: July 2012

Introduction

Acute pain is a hallmark of sickle cell disease (SCD) for which frequent hospital admissions may be required, affecting the quality of life of patients.

Objectives

To characterise the relationship between adult patient self-reported sickle cell pain, mood and quality of life during and after hospital admissions.

Design

Longitudinal study across three time-points.

Setting

Secondary care, single specialist sickle cell centre.

Participants

510 adult patients with SCD admitted to hospital daycare or inpatient units.

Outcome measures

Self-assessments of pain, mood and health-related quality of life with health utility (measured on the EQ-5D) on admission, before discharge and at 1-week postdischarge.

Results

Mood, general health and quality of life showed significant steady improvements with reduction of pain in patients with SCD on admission to hospital, before discharge and at 1-week follow-up (p<0.01). Health utility scores derived from the EQ-5D showed a negative association with pain in regression analysis over the three time-points.

Conclusion

Examining health-related quality of life and health utility in relation to pain during hospital admissions is valuable in terms of targeting appropriate psychological interventions within the context of a multidisciplinary approach to managing sickle cell pain. This has implications for healthcare costs.
Transvaginal ultrasound probe contamination by the human papillomavirus in the emergency department
Authors: Ma Shuk Ting Christine , Yeung A C , Chan Paul Kay Sheung , Graham Colin A
Published: July 2012

Objective

To determine if human papillomavirus (HPV) DNA can be detected on the transvaginal sonography (TVS) probe in the emergency department (ED) and whether the current barrier method plus disinfection can prevent HPV contamination of the TVS probe.

Methods

This was a two-part cross-sectional study. In the first part, surveillance samples were taken from the TVS probe for HPV DNA detection daily for 2 months. In the second part, patients presenting with early pregnancy complications were identified in the ED and high vaginal swabs were taken for HPV DNA testing. Several probe swabs were taken to identify if contamination was possible in cases where the procedure was done on an HPV carrier.

Results

A total of 120 surveillance samples were obtained, nine of which (7.5%) tested positive for HPV DNA. In the second part, 76 women were recruited, of whom 14 (18.4%) were HPV carriers. After the procedure and disinfection of the probe, three out of the 14 probe samples (21%) were HPV DNA positive.

Conclusions

HPV is commonly encountered in the ED and contamination of the TVS probe with HPV is possible. Although it is difficult to prove the viability and infectivity of the virus, vigilant infection control measures should be maintained.
The potential impact of a social redistribution of specific risk factors on socioeconomic inequalities in mortality: illustration of a method based on population attributable fractions
Authors: Hoffmann Rasmus , Eikemo Terje Andreas , Kulhánová Ivana , Dahl Espen , Deboosere Patrick , Dzúrová Dagmar , van Oyen Herman , Rychtaříková Jitka , Strand Bjørn Heine , Mackenbach Johan P
Published: July 2012

Background

Socioeconomic differences in health are a major challenge for public health. However, realistic estimates to what extent they are modifiable are scarce. This problem can be met through the systematic application of the population attributable fraction (PAF) to socioeconomic health inequalities.

Methods

The authors used cause-specific mortality data by educational level from Belgium, Norway and Czech Republic and data on the prevalence of smoking, alcohol, lack of physical activity and high body mass index from national health surveys. Information on the impact of these risk factors on mortality comes from the epidemiological literature. The authors calculated PAFs to quantify the impact on socioeconomic health inequalities of a social redistribution of risk factors. The authors developed an Excel tool covering a wide range of possible scenarios and the authors compare the results of the PAF approach with a conventional regression.

Results

In a scenario where the whole population gets the risk factor prevalence currently seen among the highly educated inequalities in mortality can be reduced substantially. According to the illustrative results, the reduction of inequality for all risk factors combined varies between 26% among Czech men and 94% among Norwegian men. Smoking has the highest impact for both genders, and physical activity has more impact among women.

Conclusions

After discussing the underlying assumptions of the PAF, the authors concluded that the approach is promising for estimating the extent to which health inequalities can be potentially reduced by interventions on specific risk factors. This reduction is likely to differ substantially between countries, risk factors and genders.
Technics of touch in the neonatal intensive care
Authors: van Manen Michael
Published: July 2012

Medical technologies, although often crucial for the provision of healthcare, may carry unintended significance for patients and their families. The highly technicised neonatal intensive care unit (NICU) is the place where parents of hospitalised baby have their early encounters with their child. The aim of this study is to investigate phenomenologically how the contact and relation between parent and child may be affected by the mediating presence and use of the techno-medical features and equipments of the NICU. Three common technologies are examined for the ways they condition the kinds of contact afforded between parents and child: the isolette, the feeding tube and the brain imaging equipment. The concluding recommendations speak of the need for understanding the relational experiences of parents of hospitalised babies, and the tactful sensitivities required of the healthcare teams who provide care to these families.
Repeat chlamydia screening among adolescents: cohort study in a school-based programme in New Orleans
Authors: Low Nicola , Forster Mathieu , Taylor Stephanie N , Nsuami M Jacques
Published: July 2012

Objectives

To describe uptake of chlamydia screening, determine rates of repeated yearly screening and investigate determinants of repeated participation in an organised school-based screening programme.

Methods

The authors analysed data from 1995 to 2005 from female and male students in up to 13 schools in New Orleans, Louisiana, USA. The authors calculated proportions of students tested among all enrolled students and among those with parental consent and the percentage of positive chlamydia tests in each school year. The authors used random effects logistic regression to examine the effect of past screening history on subsequent participation.

Results

35 041 students were registered for at least one school year. Overall coverage was >30% in all school years. Among all students registered for 4 years, 10.6% (95% CI 9.3% to 12.0%) of women and 12.7% (95% CI 11.2% to 14.2%) of men had a test every year. Among students with parental consent for 4 years, 49.3% (95% CI 44.6% to 54.1%) of women and 59.3% (95% CI 54.5% to 64.0%) of men had a test every year. Among students registered for 2 or more years, those with a previous positive chlamydia test were less likely to have a subsequent test (female adjusted OR 0.77, 95% CI 0.67 to 0.88 and male adjusted OR 0.84, 95% CI 0.69 to 1.02). Chlamydia positivity increased over time.

Conclusions

High levels of uptake can be achieved in school-based chlamydia screening programmes, but repeated yearly screening is difficult to sustain over time.
Influences of temperature, oxidative stress, and phosphorylation on binding of heat shock proteins in skeletal muscle fibers
Authors: Larkins Noni T. , Murphy Robyn M. , Lamb Graham D.
Published: July 2012

Heat shock proteins (HSPs) help maintain cellular function in stressful situations, but the processes controlling their interactions with target proteins are not well defined. This study examined the binding of HSP72, HSP25, and αB-crystallin in skeletal muscle fibers following various stresses. Rat soleus (SOL) and extensor digitorum longus (EDL) muscles were subjected in vitro to heat stress or strongly fatiguing stimulation. Superficial fibers were “skinned” by microdissection and HSP diffusibility assessed from the extent of washout following 10- to 30 min exposure to a physiological intracellular solution. In fibers from nonstressed (control) SOL muscle, >80% of each HSP is readily diffusible. However, after heating a muscle to 40°C for 30 min ∼95% of HSP25 and αB-crystallin becomes tightly bound at nonmembranous myofibrillar sites, whereas HSP72 bound at membranous sites only after heat treatment to ≥44°C. The ratio of reduced to oxidized cytoplasmic glutathione (GSH:GSSG) decreased approximately two- and fourfold after heating muscles to 40° and 45°C, respectively. The reducing agent dithiothreitol reversed HSP72 binding in heated muscles but had no effect on the other HSPs. Intense in vitro stimulation of SOL muscles, sufficient to elicit substantial oxidation-related loss of maximum force and approximately fourfold decrease in the GSH:GSSG ratio, had no effect on diffusibility of any of the HSPs. When skinned fibers from heat-treated muscles were bathed with additional exogenous HSP72, total binding increased approximately two- and 10-fold, respectively, in SOL and EDL fibers, possibly reflective of the relative sarco(endo)plasmic reticulum Ca2+-ATPase pump densities in the two fiber types. Phosphorylation at Ser59 on αB-crystallin and Ser85 on HSP25 increased with heat treatment but did not appear to determine HSP binding. The findings highlight major differences in the processes controlling binding of HSP72 and the two small HSPs. Binding was not directly related to cytoplasmic oxidative status, but oxidation of cysteine residues influenced HSP72 binding.
Downregulation of vitamin C transporter SVCT-2 in doxorubicin-induced cardiomyocyte injury
Authors: Ludke Ana R. , Sharma Anita K. , Akolkar Gauri , Bajpai Gunjan , Singal Pawan K.
Published: July 2012

Vitamin C (Vit C) has been shown to be protective against doxorubicin (Dox)-induced cardiotoxicity. However, Vit C uptake into cardiomyocytes is poorly understood. Furthermore, whether the antioxidant enzyme reserve is enhanced by Vit C is also not known. The present study investigated an influence of Dox on Vit C transporters, expression of endogenous antioxidant reserve as well as enzymes, oxidative stress, and apoptosis in isolated cardiomyocytes. Cardiomyocytes isolated from adult Sprague-Dawley rats were exposed to control (culture medium 199 alone), Dox (10 μM), Vit C (25 μM), and Vit C + Dox for 24 h. Vit C transporter expression and localization, oxidative stress, antioxidant enzymes, and apoptosis were studied. Expression and localization of sodium-dependent vitamin C transporter-2 (SVCT-2) in the sarcolemma was reduced by Dox, but Vit C supplementation was able to blunt this change. There was a decrease in the expression of antioxidant enzymes glutathione peroxidase (GPx), catalase, and Cu/Zn superoxide dismutase (SOD) due to Dox, but only GPx expression was completely prevented and Cu/Zn SOD was partially rescued by Vit C. Dox-induced decrease in antioxidant reserve and increase in oxidative stress were partially mitigated by Vit C. Dox-induced apoptosis was ameliorated by Vit C. It is suggested that cardioprotection offered by Vit C in Dox-induced cardiomyopathy may involve an upregulation of SVCT-2 transporter followed by a reduction in oxidative stress as well as blunting of cardiomyocyte injury.
Tyrosine phosphatase PTP-MEG2 negatively regulates vascular endothelial growth factor receptor signaling and function in endothelial cells
Authors: Hao Qin , Samten Buka , Ji Hong-Long , Zhao Z. Joe , Tang Hua
Published: July 2012

Protein tyrosine phosphorylation is a fundamental mechanism for diverse physiological processes, which is regulated by protein tyrosine kinases and protein tyrosine phosphatases (PTPs). In this study, we searched for protein substrates of PTP-MEG2 (also called PTPN9), a nonreceptor PTP, and investigated its function in endothelial cells (ECs). By using a PTP-MEG2 substrate-trapping DA mutant, we found that a couple of tyrosine-phosphorylated proteins were associated with the DA mutant but not wild-type PTP-MEG2 and that the association was enhanced by vascular endothelial growth factor (VEGF) in ECs. We further found that VEGF receptor 2 (VEGFR2) was coimmunopricipitated with the DA mutant but not wild-type PTP-MEG2. The VEGF-induced phosphorylation of VEGFR2 on Tyr1175, a critical autophosphorylation site for VEGFR2 signaling, was inhibited 70% by overexpression of wild-type PTP-MEG2 but was enhanced (2.2-fold) by the DA mutant of PTP-MEG2. We also found that PTP-MEG2 DA mutant preferentially associated with Janus kinase 1 (JAK1) but not with other JAK kinases (Tyk2 and JAK2) present in ECs and regulated JAK1 tyrosine phosphorylation. Lastly, the VEGF-induced signal transduction and the production of interleukin (IL)-6 were significantly enhanced by PTP-MEG2 knockdown in ECs, whereas the VEGF-induced IL-6 production was inhibited 50% by PTP-MEG2 overexpression. Thus we have indentified VEGFR2 as a PTP-MEG2 substrate, and our findings indicate that PTP-MEG2 is a negative regulator of VEGFR2 signaling and function in ECs.
IL-13-induced changes in endogenous glucocorticoid metabolism in the lung regulate the proasthmatic response
Authors: Josephson Maureen B. , Jiao Junfang , Xu Shuyun , Hu Aihua , Paranjape Chinmay , Grunstein Judith S. , Grumbach Yael , Nino Gustavo , Kreiger Portia A. , McDonough Joseph , Grunstein Michael M.
Published: July 2012

Endogenous glucocorticoid (GC) activation is regulated by the intracellular GC-activating and -inactivating enzymes 11β-hydroxysteroid dehydrogenase (11β-HSD)1 and 11β-HSD2, respectively, that catalyze interconversion of inert cortisone and its bioactive metabolite cortisol. Because endogenous GCs are critically implicated in suppressing the asthmatic state, this study examined the roles of the 11β-HSD enzymes in regulating GC activation and bronchoprotection during proasthmatic stimulation. Airway hyperresponsiveness to methacholine and inflammation were assessed in rabbits following inhalation of the proasthmatic/proinflammatory cytokine IL-13 with and without pretreatment with the 11β-HSD inhibitor carbenoxolone (CBX). Additionally, IL-13-induced changes in 11β-HSD isozyme expression and GC metabolism were examined in epithelium-intact and -denuded tracheal segments and peripheral lung tissues. Finally, the effects of pretreatment with CBX or 11β-HSD2-targeted siRNAs were investigated with respect to cortisol prevention of IL-13-induced airway constrictor hyperresponsiveness and eotaxin-3 production by airway epithelial cells. IL-13-exposed rabbits exhibited airway hyperresponsiveness, inflammation, and elevated bronchoalveolar lung fluid levels of eotaxin-3. These responses were inhibited by pretreatment with CBX, suggesting a permissive proasthmatic role for 11β-HSD2. Supporting this concept, extended studies demonstrated that 1) IL-13-treated tracheal epithelium and peripheral lung tissues exhibit upregulated 11β-HSD2 activity, 2) the latter impairs cortisone-induced cortisol accumulation and the ability of administered cortisol to prevent both IL-13-induced heightened airway contractility and eotaxin-3 release from epithelial cells, and 3) these proasthmatic responses are prevented by cortisol administration in the presence of 11β-HSD2 inhibition. Collectively, these data demonstrate that the proasthmatic effects of IL-13 are enabled by impaired endogenous GC activation in the lung that is attributed to upregulation of 11β-HSD2 in the pulmonary epithelium.
Hypoxia sensitivity of a voltage-gated potassium current in porcine intrapulmonary vein smooth muscle cells
Authors: Dospinescu Ciprian , Widmer Hélène , Rowe Iain , Wainwright Cherry , Cruickshank Stuart F.
Published: July 2012

Hypoxia contracts the pulmonary vein, but the underlying cellular effectors remain unclear. Utilizing contractile studies and whole cell patch-clamp electrophysiology, we report for the first time a hypoxia-sensitive K+ current in porcine pulmonary vein smooth muscle cells (PVSMC). Hypoxia induced a transient contractile response that was 56 ± 7% of the control response (80 mM KCl). This contraction required extracellular Ca2+ and was sensitive to Ca2+ channel blockade. Blockade of K+ channels by tetraethylammonium chloride (TEA) or 4-aminopyridine (4-AP) reversibly inhibited the hypoxia-mediated contraction. Single-isolated PVSMC (typically 159.1 ± 2.3 μm long) had mean resting membrane potentials (RMP) of −36 ± 4 mV with a mean membrane capacitance of 108 ± 3.5 pF. Whole cell patch-clamp recordings identified a rapidly activating, partially inactivating K+ current ( IKH) that was hypoxia, TEA, and 4-AP sensitive. IKH was insensitive to Penitrem A or glyburide in PVSMC and had a time to peak of 14.4 ± 3.3 ms and recovered in 67 ms following inactivation at +80 mV. Peak window current was −32 mV, suggesting that IKH may contribute to PVSMC RMP. The molecular identity of the potassium channel is not clear. However, RT-PCR, using porcine pulmonary artery and vein samples, identified Kv1.5, Kv2.1, and BK, with all three being more abundant in the PV. Both artery and vein expressed STREX, a highly conserved and hypoxia-sensitive BK channel variant. Taken together, our data support the hypothesis that hypoxic inhibition of IKH would contribute to hypoxic-induced contraction in PVSMC.
ExperimentalPneumocystislung infection promotes M2a alveolar macrophage-derived MMP12 production
Authors: Nelson Michael P. , Christmann Benjamin S. , Dunaway Chad W. , Morris Alison , Steele Chad
Published: July 2012

Among several bacterial and viral pathogens, the atypical fungal organism Pneumocystis jirovecii has been implicated as a contributor to the pathogenesis of chronic obstructive pulmonary disease (COPD). In a previous study, we reported that Pneumocystis-colonized HIV-positive subjects had worse obstruction of airways and higher sputum levels of macrophage elastase/matrix metalloproteinase 12 (MMP12), a protease strongly associated with the development of COPD. Here, we examined parameters of Pneumocystis-induced MMP12 in the lungs of mice and its role in the lung immune response to murine Pneumocystis. Initial studies demonstrated that P. murina exposure induced Mmp12 mRNA expression in whole lungs and alveolar macrophages (AMs), which was dependent on the presence of CD4+ T cells as well as signal transducer and activator of transcription 6. Mmp12 mRNA expression was upregulated in AMs by interleukin (IL)-4 treatment, but downregulated by interferon (IFN)-γ, indicating preferential expression in alternatively activated (M2a) macrophages. IL-4 treatment induced the 54-kDa proenzyme form of MMP12 and the 22-kDa fully processed and active form, whereas IFN-γ failed to induce either. Despite a reported antimicrobial role in macrophage phagolysosomes, mice deficient in MMP12 were not found to be more susceptible to lung infection with P. murina. Collectively, our data indicate that MMP12 induction is a component of the P. murina-induced M2 response and thus provides insight into the link between Pneumocystis colonization/infection and exacerbations in COPD.
Mitochondrial DNA-depleted A549 cells are resistant to bleomycin
Authors: Brar Sukhdev S. , Meyer Joel N. , Bortner Carl D. , Van Houten Bennett , Martin William J.
Published: July 2012

Alveolar epithelial cells are considered to be the primary target of bleomycin-induced lung injury, leading to interstitial fibrosis. The molecular mechanisms by which bleomycin causes this damage are poorly understood but are suspected to involve generation of reactive oxygen species and DNA damage. We studied the effect of bleomycin on mitochondrial DNA (mtDNA) and nuclear DNA (nDNA) in human alveolar epithelial A549 cells. Bleomycin caused an increase in reactive oxygen species production, DNA damage, and apoptosis in A549 cells; however, bleomycin induced more mtDNA than nDNA damage. DNA damage was associated with activation of caspase-3, cleavage of poly(ADP-ribose) polymerase, and cleavage and activation of protein kinase D1 (PKD1), a newly identified mitochondrial oxidative stress sensor. These effects appear to be mtDNA-dependent, because no caspase-3 or PKD1 activation was observed in mtDNA-depleted (ρ0) A549 cells. Survival rate after bleomycin treatment was higher for A549 ρ0 than A549 cells. These results suggest that A549 ρ0 cells are more resistant to bleomycin toxicity than are parent A549 cells, likely in part due to the depletion of mtDNA and impairment of mitochondria-dependent apoptotic pathways.
Effect of nitric oxide on epithelial ion transports in noncystic fibrosis and cystic fibrosis human proximal and distal airways
Authors: Blouquit-Laye Sabine , Dannhoffer Luc , Braun Camille , Dinh-Xuan Anh-Tuan , Sage Edouard , Chinet Thierry
Published: July 2012

The airways of patients with cystic fibrosis (CF) exhibit decreased nitric oxide (NO) concentrations, which might affect airway function. The aim of this study was to determine the effects of NO on ion transport in human airway epithelia. Primary cultures of non-CF and CF bronchial and bronchiolar epithelial cells were exposed to the NO donor sodium nitroprusside (SNP), and bioelectric variables were measured in Ussing chambers. Amiloride was added to inhibit the Na+channel ENaC, and forskolin and ATP were added successively to stimulate cAMP- and Ca2+-dependent Cl−secretions, respectively. The involvement of cGMP was assessed by measuring the intracellular cGMP concentration in bronchial cells exposed to SNP and the ion transports in cultures exposed to 1H-[1,2,4]oxadiazolo-[4,3-a]quinoxalin-1-one, an inhibitor of the soluble guanylate cyclase (ODQ), or to 8Z, a cocktail of 8-bromo-cGMP and zaprinast (phosphodiesterase 5 inhibitor). SNP decreased the baseline short-circuit current ( Isc) and the changes in Iscinduced by amiloride, forskolin, and ATP in non-CF bronchial and bronchiolar cultures. The mechanism of this inhibition was studied in bronchial cells. SNP increased the intracellular cGMP concentration ([cGMP]i). The inhibitory effect of SNP was abolished by 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, an NO scavenger (PTIO) and ODQ and was partly mimicked by increasing [cGMP]i. In CF cultures, SNP did not significantly modify ion transport; in CF bronchial cells, 8Z had no effect; however, SNP increased the [cGMP]i. In conclusion, exogenous NO may reduce transepithelial Na+absorption and Cl−secretion in human non-CF airway epithelia through a cGMP-dependent pathway. In CF airways, the NO/cGMP pathway appears to exert no effect on transepithelial ion transport.
MAFbx, MuRF1, and the stress-activated protein kinases are upregulated in muscle cells during total knee arthroplasty
Authors: Bailey Ashley N. , Hocker Austin D. , Vermillion Benjamin R. , Smolkowski Keith , Shah Steven N. , Jewett Brian A. , Dreyer Hans C.
Published: July 2012

Total knee arthroplasty (TKA) is the most common and a cost-effective surgical remediation for older adults with long-standing osteoarthritis. In parallel with the expanding population of older adults, the number of TKAs performed annually is projected to be 3.48 million by 2030. During this surgery, a tourniquet is used to stop blood flow to the operative leg. However, the molecular pathways that are affected by tourniquet use during TKA continue to be elucidated. We hypothesized that components of the catabolic FoxO3a (i.e., MuRF1, MAFbx, and Bnip3) pathway, as well as the cellular stress pathways [i.e., stress-activated protein kinase (SAPK)/JNK and MAPKs], are upregulated during TKA. The purpose of this study was to measure changes in transcripts and proteins involved in muscle cell catabolic and stress-activated pathways. We obtained muscle biopsies from subjects, 70 ± 1.3 yr, during TKA, from the vastus lateralis at baseline (before tourniquet inflation), during maximal ischemia (just before tourniquet release), and during reperfusion. Total tourniquet time was 43 ± 2 min and reperfusion time was 16 ± 1. Significant increases in FoxO3a downstream targets, MAFbx and MuRF1, were present for mRNA levels during ischemia (MAFbx, P = 0.04; MuRF1, P = 0.04), and protein expression during ischemia (MAFbx, P = 0.002; MuRF1, P = 0.001) and reperfusion (MuRF1, P = 0.002). Additionally, stress-activated JNK gene expression ( P = 0.01) and protein were elevated during ischemia ( P = 0.001). The results of this study support our hypothesis that protein degradation pathways are stimulated during TKA. Muscle protein catabolism is likely to play a role in the rapid loss of muscle volume measured within 2 wk of this surgery.
Collagen VIII influences epithelial phenotypic changes in experimental diabetic nephropathy
Authors: Loeffler Ivonne , Liebisch Marita , Wolf Gunter
Published: July 2012

Epithelial-to-mesenchymal transition (EMT) is an important mechanism of renal tubulo-interstitial fibrosis in diabetic nephropathy (DN). Inducers of EMT, among others, are transforming growth factor-β1(TGF-β1) as well as extracellular collagens. In renal cells of diabetic mice and in kidneys of patients with DN, the expression of collagen VIII (gene: Col8α1/α2) is enhanced and characteristic features of DN in streptozotocin (STZ)-induced diabetic Col8α1/α2 knockout-(KO) mice are attenuated compared with diabetic wild-type mice. This study aimed to investigate whether collagen type VIII may influence the induction of EMT. DN was induced in wild-type and Col8α1/α2-KO mice using the established and widely accepted low-dose STZ model [treatment for 5 consecutive days (50 mg/kg)]. Healthy and diabetic mice were analyzed for changes in renal function and the expression of EMT-related genes and proteins. Renal morphology, fibrosis, and various EMT markers were studied in kidneys using immunohistological and molecular biological methods. Knockout of Col8α1/α2 attenuated albuminuria, extracellular matrix production, as well as fibrosis. Furthermore, the kidneys of diabetic Col8α1/α2-KO mice showed a marked reduction in interstitial myofibroblasts, and in tubular cells the inhibition of the expression of epithelial markers as well as the expression of typical mesenchymal markers was reduced. The present study demonstrates that in contrast to diabetic wild-type mice EMT-like changes were attenuated in diabetic Col8α1/α2-KO mice, which indicates that either collagen VIII may be one of the major inducers of EMT-like changes in kidneys of diabetic wild-type mice or/possibly the lack of Col8α1/α2 disrupts TGF-β1-induced EMT-like changes.
NAC1 Is an Actin-Binding Protein That Is Essential for Effective Cytokinesis in Cancer Cells
Authors: Yap Kai Lee , Fraley Stephanie I. , Thiaville Michelle M. , Jinawath Natini , Nakayama Kentaro , Wang Jianlong , Wang Tian-Li , Wirtz Denis , Shih Ie-Ming
Published: July 2012

NAC1 is a transcriptional corepressor protein that is essential to sustain cancer cell proliferation and migration. However, the underlying molecular mechanisms of NAC1 function in cancer cells remain unknown. In this study, we show that NAC1 functions as an actin monomer–binding protein. The conserved BTB protein interaction domain in NAC1 is the minimal region for actin binding. Disrupting NAC1 complex function by dominant-negative or siRNA strategies reduced cell retraction and abscission during late-stage cytokinesis, causing multinucleation in cancer cells. In Nac1-deficient murine fibroblasts, restoring NAC1 expression was sufficient to partially avert multinucleation. We found that siRNA-mediated silencing of the actin-binding protein profilin-1 in cancer cells caused a similar multinucleation phenotype and that NAC1 modulated the binding of actin to profillin-1. Taken together, our results indicate that the NAC1/actin/profilin-1 complex is crucial for cancer cell cytokinesis, with a variety of important biologic and clinical implications. Cancer Res; 72(16); 4085–96. ©2012 AACR.
HG-829 Is a Potent Noncompetitive Inhibitor of the ATP-Binding Cassette Multidrug Resistance Transporter ABCB1
Authors: Caceres Gisela , Robey Robert W. , Sokol Lubomir , McGraw Kathy L. , Clark Justine , Lawrence Nicholas J. , Sebti Said M. , Wiese Michael , List Alan F.
Published: July 2012

Transmembrane drug export mediated by the ATP-binding cassette (ABC) transporter P-glycoprotein contributes to clinical resistance to antineoplastics. In this study, we identified the substituted quinoline HG-829 as a novel, noncompetitive, and potent P-glycoprotein inhibitor that overcomes in vitro and in vivo drug resistance. We found that nontoxic concentrations of HG-829 restored sensitivity to P-glycoprotein oncolytic substrates. In ABCB1-overexpressing cell lines, HG-829 significantly enhanced cytotoxicity to daunorubicin, paclitaxel, vinblastine, vincristine, and etoposide. Coadministration of HG-829 fully restored in vivo antitumor activity of daunorubicin in mice without added toxicity. Functional assays showed that HG-829 is not a Pgp substrate or competitive inhibitor of Pgp-mediated drug efflux but rather acts as a noncompetitive modulator of P-glycoprotein transport function. Taken together, our findings indicate that HG-829 is a potent, long-acting, and noncompetitive modulator of P-glycoprotein export function that may offer therapeutic promise for multidrug-resistant malignancies. Cancer Res; 72(16); 4204–13. ©2012 AACR.
Chromosome 5q Loss in Colorectal Flat Adenomas
Authors: Voorham Quirinus J.M. , Carvalho Beatriz , Spiertz Angela J. , van Grieken Nicole C.T. , Mongera Sandra , Rondagh Eveline J.A. , van de Wiel Mark A. , Jordanova Ekaterina S. , Ylstra Bauke , Kliment Martin , Grabsch Heike , Rembacken Bjorn J. , Arai Tomio , de Bruïne Adriaan P. , Sanduleanu Silvia , Quirke Philip , Mulder Chris J.J. , van Engeland Manon , Meijer Gerrit A.
Published: July 2012

Purpose: Flat adenomas are a subgroup of colorectal adenomas that have been associated with a more aggressive clinical behavior compared with their polypoid counterparts. Here, we aimed to compare one of the molecular changes most explicitly associated with adenoma to carcinoma progression, that is, chromosomal instability, between flat and polypoid colorectal adenomas.

Experimental Design: Consecutive series of 83 flat and 35 polypoid adenomas were analyzed for DNA copy number changes using a high-resolution array comparative genomic hybridization platform, microsatellite instability (MSI) status, and for mutations in the adenomatous polyposis coli (APC) gene. Immunohistochemical stainings for CD3, CD8, and FoxP3 expression were carried out.

Results: Patterns of DNA copy number changes differed between the two phenotypes, with significantly more frequent loss of 5q14.3 and 5q15-q31.1 in flat adenomas, whereas losses of 1p36.32-p35.3, 10q25.3, 17p12, and chromosome 18 were more frequent in polypoid adenomas (false discovery rate < 0.2). MSI was observed in one flat adenoma. As the 5q15-q31.1 region harbors the APC locus, APC mutation status was investigated, showing significantly less mutations in flat adenomas (P = 0.04). An initial exploration of a possible association of 5q loss with inflammation indicated that tumor-infiltrating lymphocytes were more abundant in the stroma of flat adenomas compared with that of polypoid adenomas.

Conclusion: Flat and polypoid adenomas have partially distinct chromosomal profiles, consistent with differences in the biology underlying these phenotypes. Alterations more specific to flat adenomas, in particular 5q loss, may be associated with inflammation. Clin Cancer Res; 18(17); 4560–9. ©2012 AACR.
Anemia and Survival in Chronic Obstructive Pulmonary Disease: A Dichotomous rather than a Continuous Predictor
Authors: Boutou Afroditi K. , Karrar Sarah , Hopkinson Nicholas S. , Polkey Michael I.
Published: July 2012

Background: Chronic obstructive pulmonary disease (COPD) is a disorder characterized by high mortality. Hemoglobin (Hb) concentration has a prognostic impact on COPD patients receiving long-term oxygen treatment, but its value as an independent predictor of survival among stable COPD outpatients has not been fully clarified by previous studies. Objectives: To investigate the potential association between anemia and survival in a cohort of stable COPD outpatients. Methods: A cohort of stable COPD patients, who had had their first spirometry, blood count and serum chemistry profile done between October 1999 and November 2010 were retrospectively analyzed. Patients with heart failure, renal impairment, malignancy, recent hemorrhage and other causes of anemia were excluded. Variables that were found to be univariately associated with survival entered a multivariate stepwise Cox regression analysis model, to allow independent predictors of survival to be identified. Results: Of 294 patients (67.9 ± 9.8 years old, 64.6% male) 15.6% were anemic (Hb <13 g/dl). The median survival differed significantly between anemic [68.7 (18.1–91.5) months] and nonanemic [79.8 (57.5–98.4) months, p = 0.035] individuals. Independent predictors of mortality in the total population were anemia [hazard ratio (HR) 1.87, 95% confidence interval (CI) 1.06–3.29], age (HR 1.08, 95% CI 1.04–1.12) and forced expiratory volume in 1 s (FEV1) % predicted (HR 0.94, 95% CI 0.92–0.97); the Hb concentration was neither univariately nor multivariately associated with mortality. Conclusion: This is the first study to indicate that anemia (but not the Hb value) is independently associated with survival in stable COPD outpatients. It would be better to treat this as a categorical variable in future scoring systems.
Antithrombotic Properties of Water-Soluble Carbon Monoxide-Releasing Molecules
Authors: Kramkowski Karol , Leszczynska Agnieszka , Mogielnicki Andrzej , Chlopicki Stefan , Fedorowicz Andrzej , Grochal Elzbieta , Mann Brian , Brzoska Tomasz , Urano Tetsumei , Motterlini Roberto , Buczko Wlodzimierz
Published: July 2012

Objective—

We compared the antithrombotic effects in vivo of 2 chemically different carbon monoxide–releasing molecules (CORM-A1 and CORM-3) on arterial and venous thrombus formation and on hemostatic parameters such as platelet activation, coagulation, and fibrinolysis. The hypotensive response to CORMs and their effects on whole blood gas analysis and blood cell count were also examined.

Methods and Results—

CORM-A1 (10–30 µmol/kg, i.v.), in a dose-dependent fashion, significantly decreased weight of electrically induced thrombus in rats, whereas CORM-3 inhibited thrombosis only at the highest dose used (30 µmol/kg). CORM-A1 showed a direct and stronger inhibition of platelet aggregation than CORM-3 in healthy rats, both in vitro and in vivo. The antiaggregatory effect of CORM-A1, but not CORM-3, correlated positively with weight of the thrombus. Concentration of active plasminogen activator inhibitor-1 in plasma also decreased in response to CORM-A1, but not to CORM-3. Neither CORM-A1 nor CORM-3 had an effect on plasma concentration of active tissue plasminogen activator. CORM-3, but not CORM-A1, decreased the concentration of fibrinogen, fibrin generation, and prolonged prothrombin time. Similarly, laser-induced venous thrombosis observed intravitally via confocal system in green fluorescent protein mice was significantly decreased by CORMs. Although both CORM-A1 and CORM-3 (30 µmol/kg) decreased platelets accumulation in thrombus, only CORM-A1 (3–30 µmol/kg) inhibited platelet activation to phosphatidylserine on their surface.

Conclusion—

CORM-3 and CORM-A1 inhibited thrombosis in vivo, however CORM-A1, which slowly releases carbon monoxide, and displayed a relatively weak hypotensive effect had a more pronounced antithrombotic effect associated with a stronger inhibition of platelet aggregation associated with a decrease in active plasminogen activator inhibitor-1 concentration. In contrast, the fast CO releaser CORM-3 that displayed a more pronounced hypotensive effect inhibited thrombosis primarily through a decrease in fibrin generation, but had no direct influence on platelet aggregation and fibrynolysis.
Caveolin-1 Plays a Critical Role in the Differentiation of Monocytes into Macrophages
Authors: Fu Yi , Moore Xiao-Lei , Lee Man K. S. , Fernández-Rojo Manuel A. , Parat Marie-Odile , Parton Robert G. , Meikle Peter J. , Sviridov Dmitri , Chin-Dusting Jaye P. F.
Published: July 2012

Objective—

Monocyte to macrophage differentiation is an essential step in atherogenesis. The structure protein of caveolae, caveolin-1, is increased in primary monocytes after its adhesion to endothelium. We explore the hypothesis that caveolin-1 plays a role in monocyte differentiation to macrophages.

Methods and Results—

Both phorbol myristate acetate–induced THP-1 and colony-stimulating factor–induced primary monocyte differentiation was associated with an increase in cellular caveolin-1 expression. Overexpression of caveolin-1 by transfection increased macrophage surface markers and inflammatory genes, whereas caveolin-1 knockdown by small interfering RNA or knockout reduced these. Also, caveolin-1 knockdown inhibited the differentiation–induced nuclear translocation of early growth response 1 (EGR-1) through extracellular signal-regulated kinase phosphorylation, further decreased the binding of EGR-1 to CD115 promoter, thus decreasing EGR-1 transcriptional activity. In functional assays, caveolin-1 inhibited transmigration but promoted phagocytosis in the monocyte–macrophage lineage. Decreasing caveolin-1 inhibited the uptake of modified low-density lipoprotein and reduced cellular lipid content. Finally, we showed that caveolin-1 knockout mice displayed less monocyte differentiation than wild-type mice and that EGR-1 transcription activity was also decreased in these mice because of the inhibition of extracellular signal-regulated kinase phosphorylation.

Conclusion—

Caveolin-1 promotes monocyte to macrophage differentiation through the regulation of EGR-1 transcriptional activity, suggesting that phagocytic caveolin-1 may be critical for atherogenesis.
Modest Increase in Peak VO
2
Is Related to Better Clinical Outcomes in Chronic Heart Failure Patients
Authors: Swank Ann M. , Horton John , Fleg Jerome L. , Fonarow Gregg C. , Keteyian Steven , Goldberg Lee , Wolfel Gene , Handberg Eileen M. , Bensimhon Dan , Illiou Marie-Christine , Vest Marianne , Ewald Greg , Blackburn Gordon , Leifer Eric , Cooper Lawton , Kraus William E. ,   and for the HF-ACTION Investigators
Published: July 2012

Background—

The prognostic ability of a single measurement of peak oxygen uptake (VO
2
) is well established in patients with chronic heart failure. The relation between a change in peak VO
2
and clinical outcomes is not well defined.

Methods and Results—

This investigation determined whether an increase in peak VO
2
was associated with a lower risk of the primary end point of time to all-cause mortality or all-cause hospitalization and 3 secondary end points. In Heart Failure and a Controlled Trial to Investigate Outcomes of Exercise Training, an exercise training trial for patients with systolic heart failure, cardiopulmonary exercise tests were performed at baseline and ≈3 months later in 1620 participants. Median peak VO
2
in the combined sample increased from 15.0 (11.9–18.0 Q1–Q3) to 15.4 (12.3–18.7 Q1–Q3) mL·kg
−1
·min
−1
. Every 6% increase in peak VO
2,
adjusted for other significant predictors, was associated with a 5% lower risk of the primary end point (hazard ratio=0.95; CI=0.93–0.98;
P
<0.001); a 4% lower risk of the secondary end point of time to cardiovascular mortality or cardiovascular hospitalization (hazard ratio=0.96; CI=0.94–0.99;
P
<0.001); an 8% lower risk of cardiovascular mortality or heart failure hospitalization (hazard ratio=0.92; CI=0.88–0.96;
P
<0.001); and a 7% lower all-cause mortality (hazard ratio=0.93; CI=0.90–0.97;
P
<0.001).

Conclusions—

Among patients with chronic systolic heart failure, a modest increase in peak VO
2
over 3 months was associated with a more favorable outcome. Monitoring the change in peak VO
2
for such patients may have benefit in assessing prognosis.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT00047437.