bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of the Programmed Death Ligand 1, B7-H1, on Gastric Epithelial Cells afterHelicobacter pyloriExposure Promotes Development of CD4+CD25+FoxP3+Regulatory T Cells
Authors: Beswick Ellen J. , Pinchuk Irina V. , Das Soumita , Powell Don W. , Reyes Victor E. 
Published: June 2007

ABSTRACTDuringHelicobacter pyloriinfection, T cells are recruited to the gastric mucosa, but the host T-cell response is not sufficient to clear the infection. Some of the recruited T cells respond in a polarized manner to a Th1 response, while others become anergic. We have previously shown that T-cell anergy may be induced during infection by the interaction of T cells with B7-H1, which is up-regulated on the gastric epithelium duringH. pyloriinfection. Recently, regulatory T (Treg) cells with a CD4+CD25highFoxP3+phenotype were found at an increased frequency in the gastric mucosa of biopsy specimens fromH. pylori-infected patients. While Treg cells are important in maintaining tolerance, they can also suppress immune responses during infection. In this study, we examined the induction of the Treg phenotype when naïve T cells were incubated with gastric epithelial cells exposed toH. pylori. The frequency of this phenotype was markedly decreased when B7-H1 was blocked with monoclonal antibodies or its expression was blocked with small interfering RNA. The functional role of these Treg cells was assessed in proliferation assays when the cells were cocultured with activated T cells, which effectively decreased proliferation of the cells.
l-Arginine Availability Regulates Inducible Nitric Oxide Synthase-Dependent Host Defense againstHelicobacter pylori
Authors: Chaturvedi Rupesh , Asim Mohammad , Lewis Nuruddeen D. , Algood Holly M. Scott , Cover Timothy L. , Kim Preston Y. , Wilson Keith T. 
Published: June 2007

ABSTRACTHelicobacter pyloriinfection of the stomach causes an active immune response that includes stimulation of inducible nitric oxide (NO) synthase (iNOS) expression. Although NO can killH. pylori, the bacterium persists indefinitely, suggesting that NO production is inadequate. We determined if the NO derived from iNOS in macrophages was dependent on the availability of its substrate,l-arginine (l-Arg). Production of NO byH. pylori-stimulated RAW 264.7 cells was dependent on thel-Arg concentration in the culture medium, and the 50% effective dose forl-Arg was 220 μM, which is above reported plasmal-Arg levels. While iNOS mRNA induction wasl-Arg independent, iNOS protein increased in anl-Arg-dependent manner that did not involve changes in iNOS protein degradation.l-Lysine, an inhibitor ofl-Arg uptake, attenuatedH. pylori-stimulated iNOS protein expression, translation, NO levels, and killing ofH. pylori. Whilel-Arg starvation suppressed global protein translation, at concentrations ofl-Arg at which iNOS protein was only minimally expressed in response toH. pylori, global translation was fully restored and eukaryotic translation initiation factor α was dephosphorylated.H. pylorilacking the generocF, which codes for a bacterial arginase, induced higher levels of NO production by increasing iNOS protein levels. When murine gastric macrophages were activated withH. pylori, supraphysiologic levels ofl-Arg were required to permit iNOS protein expression and NO production. These findings indicate thatl-Arg is rate limiting for iNOS translation and suggest that the levels ofl-Arg that occur in vivo do not permit sufficient NO generation by the host to killH. pylori.
Pseudomonas aeruginosa
Forms Biofilms in Acute Infection Independent of Cell-to-Cell Signaling
Authors: Schaber J. Andy , Triffo W. Jeffrey , Suh Sang Jin , Oliver Jeffrey W. , Hastert Mary Catherine , Griswold John A. , Auer Manfred , Hamood Abdul N. , Rumbaugh Kendra P. 
Published: June 2007

ABSTRACT

Biofilms are bacterial communities residing within a polysaccharide matrix that are associated with persistence and antibiotic resistance in chronic infections. We show that the opportunistic pathogen
Pseudomonas aeruginosa
forms biofilms within 8 h of infection in thermally injured mice, demonstrating that biofilms contribute to bacterial colonization in acute infections as well. Using light, electron, and confocal scanning laser microscopy,
P. aeruginosa
biofilms were visualized within burned tissue surrounding blood vessels and adipose cells. Although quorum sensing (QS), a bacterial signaling mechanism, coordinates differentiation of biofilms in vitro, wild-type and QS-deficient
P. aeruginosa
strains formed similar biofilms in vivo. Our findings demonstrate that
P. aeruginosa
forms biofilms on specific host tissues independently of QS.
Coordinated Expression ofBorrelia burgdorferiComplement Regulator-Acquiring Surface Proteins during the Lyme Disease Spirochete's Mammal-Tick Infection Cycle
Authors: Bykowski Tomasz , Woodman Michael E. , Cooley Anne E. , Brissette Catherine A. , Brade Volker , Wallich Reinhard , Kraiczy Peter , Stevenson Brian 
Published: June 2007

ABSTRACTThe Lyme disease spirochete,Borrelia burgdorferi, is largely resistant to being killed by its hosts’ alternative complement activation pathway. One possible resistance mechanism of these bacteria is to coat their surfaces with host complement regulators, such as factor H. Five differentB. burgdorferiouter surface proteins having affinities for factor H have been identified: complement regulator-acquiring surface protein 1 (BbCRASP-1), encoded bycspA; BbCRASP-2, encoded bycspZ; and three closely related proteins, BbCRASP-3, -4, and -5, encoded byerpP,erpC, anderpA, respectively. We now present analyses of the recently identified BbCRASP-2 andcspZexpression patterns throughout theB. burgdorferiinfectious cycle, plus novel analyses of BbCRASP-1 anderp-encoded BbCRASPs. Our results, combined with data from earlier studies, indicate that BbCRASP-2 is produced primarily during established mammalian infection, while BbCRASP-1 is produced during tick-to-mammal and mammal-to-tick transmission stages but not during established mammalian infection, and Erp-BbCRASPs are produced from the time of transmission from infected ticks into mammals until they are later acquired by other feeding ticks. Transcription ofcspZand synthesis of BbCRASP-2 were severely repressed during cultivation in laboratory medium relative to mRNA levels observed during mammalian infection, andcspZexpression was influenced by culture temperature and pH, observations which will assist identification of the mechanisms employed byB. burgdorferito control expression of this borrelial infection-associated protein.
Identification of Gene Products Involved in Biofilm Production by
Moraxella catarrhalis
ETSU-9 In Vitro
Authors: Pearson Melanie M. , Hansen Eric J. 
Published: June 2007

ABSTRACT

Moraxella catarrhalis
ETSU-9 was subjected to random transposon insertion mutagenesis to identify genes encoding products involved in the ability of the organism to form biofilms in vitro. Screening of approximately 3,000 transposon insertion mutants in the crystal violet-based biofilm assay system yielded six mutants that exhibited greatly reduced abilities to form biofilms. Three of these mutants had transposon insertions in the
uspA2H
gene, which encodes a surface protein previously shown to be involved in the ability of
M. catarrhalis
to both attach to human cell lines in vitro and resist killing by normal human serum. Random insertion mutagenesis of the
uspA2H
gene, involving the introduction of a 15-nucleotide fragment encoding 5 amino acids, was used to attempt to identify the domain(s) necessary for biofilm formation. Most of these insertions adversely affected biofilm formation, whereas the abilities of these same mutants to attach to Chang conjunctival epithelial cells in vitro were usually not reduced. Gain-of-function experiments showed that introduction of the
M. catarrhalis
ETSU-9
uspA2H
gene into
Escherichia coli
conferred biofilm formation ability on this recombinant strain. Two of the other three
M. catarrhalis
ETSU-9 transposon insertion mutants that had greatly reduced abilities to form biofilms were shown to have insertions in genes encoding products predicted to be directly or indirectly involved in cell wall metabolism.
Upregulation of CCL20 and Recruitment of CCR6+Gastric Infiltrating Lymphocytes inHelicobacter pyloriGastritis
Authors: Wu Yi-Ying , Tsai Hwei-Fang , Lin We-Cheng , Hsu Ping-I , Shun Chia-Tung , Wu Ming-Shiang , Hsu Ping-Ning 
Published: June 2007

ABSTRACTHelicobacter pyloriinfection is associated with an inflammatory response in the gastric mucosa, leading to chronic gastritis, peptic ulcers, and gastric cancer. There is increased T-cell infiltration at the site of infection withH. pylori. CCR6, a specific β-chemokine receptor for CCL20 (MIP-3α/LARC/exodus), has recently been reported to mediate lymphocyte homeostasis and immune responses in mucosal tissue, and it may play a role in chemokine-mediated lymphocyte trafficking during gastric inflammation. In this study, we investigated the role of CCR6 and its ligand, CCL20, in inducing an inflammatory response in the gastric mucosa duringH. pyloriinfection. Gastric infiltrating T lymphocytes were isolated from endoscopic biopsy specimens ofH. pylorigastritis patients and analyzed for the expression of the CCR6 chemokine receptor. Our results demonstrated that there was significantly increased CCR6 expression in CD3+T cells infiltrating the gastric mucosa, and the CCR6 ligand, the CCL20 chemokine, was selectively expressed in inflamed gastric tissues. The production of CCL20 was upregulated in response toH. pyloriin gastric epithelial cells when there was stimulation by the proinflammatory cytokines interleukin-1β and tumor necrosis factor alpha. Furthermore, recombinant CCL20 induced lymphocyte chemotaxis migration in fresh gastric T cells ex vivo, indicating that the gastric T cells could migrate toward inflammatory sites via CCR6/CCL20 interaction. Our results suggest that the interaction between CCL20 and CCR6 may play a role in chemokine-mediated lymphocyte trafficking during gastric inflammation inHelicobacterinfection.
Acute patellofemoral pain: aggravating activities, clinical examination, MRI and ultrasound findings
Authors: Brushøj C , Hölmich P , Nielsen M B , Albrecht-Beste E 
Published: June 2007

Objective:To investigate acute anterior knee pain caused by overuse in terms of pain location, aggravating activities, findings on clinical examination and ultrasound/MRI examination. To determine if acute anterior knee pain caused by overuse should be classified as a subgroup of patellofemoral pain syndrome (PFPS).Methods:In a observational study design 30 army recruits with anterior knee pain (mean duration of pain 4 weeks) were examined using the PFPS pain severity scale (PSS), knee pain diagrams, standardised clinical examination, ultrasound and MRI examinations.Results:On PSS typical knee loading activities were the most painful, while sitting with knee bend for prolonged time caused surprisingly little pain. Pain was most commonly perceived in the peripatellar area (25 patients (83%)). The most common site of pain on clinical examination was the peripatellar area (25 patients (83%)), but other synovial covered structures including the fat pad of Hoffa (12 patients (40%)), the medial plica and the joint line (12 patients (40%)) were also involved. Only eight patients (27%) experienced pain on the patellofemoral compression test. Only discrete changes was detected on MRI/ultrasound.Conclusions:Acute anterior knee pain should be regarded as a subgroup of PFPS as both symptoms and clinical examination suggests this. The clinical examination with disseminated pain in all synovial covered structures is consistent with ideas of the importance of synovium in the genesis of pain.
High eccentric strength training reduces heart rate variability in healthy older men
Authors: Melo R C , Quitério R J , Takahashi A C M , Silva E , Martins L E B , Catai A M 
Published: June 2007

Background:Evaluation of non-pharmacological therapies that improve autonomic control of the heart rate in older subjects has a clinical significance, because reduced heart rate variability (HRV) can be associated with higher cardiovascular morbidity and mortality rates.Objective:To investigate if strength training improves cardiac autonomic control in healthy older men.Methods:The HRV of nine older healthy men (mean age 62 (2.0) years) was evaluated before and after 12 weeks of isokinetic eccentric strength training (2 days/week, 2–4 sets of 8–12 repetitions at 75–80% peak torque, involving knee flexion and extension. Electrocardiogram was continuously recorded for 15 min at rest, in supine and seated positions, before and after the strength training period. To estimate strength gains, the eccentric peak torque of the dominant leg was measured at 60°/s by the same isokinetic dynamometer.Results:Mean systolic blood pressure decreased (123.78 (8.3) to 117.67 (10.2) mmHg, p<0.05) and peak torque increased (extension 210.02 (38.5) to 252.71 (60.9) N.m; flexion: 117.56 (25.1) to 132.96 (27.3) N.m, p<0.05) after the strength training. The frequency domain indices showed a significant training effect (p<0.05), since low frequency in normalised units and low frequency/high frequency ratio increased (supine, 57 (14) to 68 (14), 1.56 (0.85) to 2.35 (1.48); seated, 65 (15) to 74 (8.0), 2.48 (1.09) to 3.19 (1.31), respectively), and high frequency in normalised units decreased (supine, 43 (14) to 32 (14); seated, 35 (15) to 26 (8)) after the training period.Conclusion:The results of the present investigation suggest that high eccentric strength training performed by healthy older men increases peak torque and reduces systolic blood pressure. However, an autonomic imbalance towards sympathetic modulation predominance was induced by an unknown mechanism.
Physical performance changes after unsupervised training during the autumn/spring semester break in competitive tennis players
Authors: Kovacs Mark S , Pritchett Robert , Wickwire P Jason , Green J Matthew , Bishop Phillip 
Published: June 2007

Background:All competitive tennis players take time away from coaches throughout the year; however, little information is available as to the short-term physiological effect of these breaks.Objective:The purpose of this investigation was to evaluate the impact of a 5 week off-campus structured, yet unsupervised, break from regular training in top collegiate tennis players.Methods:A nationally ranked collegiate NCAA Division I male tennis team (n = 8) performed a test battery in December and again in January after a 5 week period of recommended, yet unsupervised, training. The tests performed were 5, 10 and 20 m sprints, spider agility test, medicine ball power throws, standing long jump, Wingate anaerobic power test, VO2max, push-up and sit-up test, grip strength and range of motion (ROM) measures (goniometer) of the shoulder, hip, hamstring and quadriceps.Results:Paired t tests (p<0.05) showed significant decreases in mean (SEM) Wingate power measurements in Watts/kg (pre: 8.35 (0.19) w/kg ; post: 7.80 (0.24) w/kg ), minimum Wingate power (pre: 5.89 (0.27) w/kg; post: 5.10 (0.38) w/kg) and VO2maxvalues (pre: 53.90 (1.11) ml/kg/min; post: 47.86 (1.54) ml/kg/min). A significant increase was seen in the athlete’s fatigue index (pre: 44.26 (2.85)%; post: 51.41 (3.53)%), fastest 5 m (pre: 1.07 (0.03) s; post: 1.12 (0.02) s), 10 m (pre: 1.79 (0.03) s; post: 1.84 (0.04) s) and 20 m (pre: 3.07 (0.05) s; post: 3.13 (0.05) s) sprint times. No significant differences were seen for the other variables tested.Conclusions:These results suggest that a 5 week interruption of normal training can result in significant reductions in speed, power and aerobic capacity in competitive tennis players, likely owing to poor compliance with the prescribed training regimen. Therefore, coaches and trainers might benefit from techniques (eg, pre- and post-testing) requiring athletes’ to have accountability for unsupervised workouts.
Match activity and physiological responses during a junior female singles tennis tournament
Authors: Fernandez-Fernandez Jaime , Mendez-Villanueva Alberto , Fernandez-Garcia Benjamin , Terrados Nicolas 
Published: June 2007

Objective:To assess physiological load in conjunction with individual patterns of match-play activity in junior female tennis players during actual singles tennis competition.Methods:Eight elite junior female tennis players (n = 8; mean (SD) age, 17.3 (1.9) years) took part in a 2 day invitational tournament. Activity pattern analysis was performed during competitive matches. Heart rate and blood lactate concentrations were measured during selected changeovers breaks in play.Results:The activity profile of junior female players were: rally duration, (mean (SD)) 8.2 (5.2) s; rest time between rallies, 17.7 (6.5) s; effective playing time, 21.9 (3.8)%; strokes per rally, 2.7 (1.7); changes of direction per rally, 2.3 (1.4). The mean (SD) heart rate and blood lactate concentration recorded during the matches were 161 (5) beats/min and 2.0 (0.8) mmol/litre. Heart rate and blood lactate concentration values were influenced by the characteristics of the match and mean (SD) heart rate was significantly higher (p = 0.004) during service games (166 (15.4) beats/min) than in return games (156 (19.6) beats/min), while blood lactate concentrations were not significantly different (p = 0.83) between service (2.3 (0.6) mmol/litre) and return games (2.3 (0.9) mmol/litre). We found a significant (p<0.05) positive relationship between rally duration, strokes per rally, changes of direction and blood lactate and heart rate responses, with stronger correlations when the players were serving.Conclusions:The physiological (ie, blood lactate and heart rate) responses associated with match play were influenced by the characteristics of the match (rally duration, strokes per rally and changes of direction), with higher heart rate on service position. Training programs should reflect these demands placed on female players during competitive match play.
Core body temperature during competition in the heat: national boys’ 14s junior tennis championships
Authors: Bergeron Michael F , McLeod Kathryn S , Coyle John F 
Published: June 2007

Objective:To examine on-court core body temperature (TC) and sweat loss, as well as pre- and post-play hydration status, in elite adolescent tennis players during a national championships event in a hot climate.Methods:Eight healthy, fit, young male tennis players (mean (SD) age 13.9 (0.9) years; mass 56.0 (10.7) kg; height 169.2 (14.7) cm) were evaluated during first-round singles competition at the National Boys’ 14s Junior Championships in the heat (wet-bulb globe temperature (WBGT) 29.6 (0.4) °C). Five of those same players were also evaluated during a same-day doubles match (WBGT 31.3 (0.5) °C).Results:During doubles (4.37 (0.35) h after singles), pre-play urine specific gravity (USG) (1.025 (0.002); p = 0.06) and total sweat loss (1.9 (0.2) litres; p = 0.10) tended to be higher before and during doubles, respectively, compared to singles. However, percentage change in body mass (−0.5 (0.3) %) tended to be comparatively less (p = 0.08), even though the doubles matches were generally longer (106.6 (11.2) vs 78.8 (10.9) min; p = 0.09) and the degree minutes total was greater (p = 0.04). TCincreased (p<0.001) during singles and remained elevated, even after 10 min following the end of play. Notably, pre-play (singles) USG was strongly associated (p = 0.005) with the players’ final TC(38.7 (0.3) °C) recorded at the end of singles play.Conclusion:Junior tennis players who begin a match not well hydrated could have progressively increasing thermal strain and a greater risk for exertional heat illness as the match advances.
South African platinum mine employees reduce smoking in 5 years
Authors: Cheyip M Y N C K , Nelson G , Ross M H , Murray J 
Published: June 2007

Background:South Africa adopted comprehensive tobacco control policies in the 1990s. Smoking has since declined in the general population, but there is little information on the effect of the campaign in labour-intensive industries, especially the mining industry where workers are exposed to dust, which may interact with tobacco smoke to cause respiratory disease.Objectives:To determine the prevalence of, and trends in, smoking in employees of a South African platinum mining company, from 1998 to 2002, and to describe some demographic factors associated with their smoking habits.Methods:This study used smoking data collected during annual fitness-to-work medical examinations. Employees were categorised into never, ever, continuous, new and ex-smokers. Data were analysed by race and age group. Age-standardised smoking prevalance rates were compared with rates in the South African general population.Results:There were 80 713 records of 25 274 mine employees for the 5-year period. The decrease in smoking prevalence over this period was significant in both black and white men, but was greater in the former (from 42.9% to 29.8%, and from 47.2% to 44.7%, respectively). In 2002, the prevalence of smoking in black mine employees was 12.1% lower than that in black men in the general population. The prevalence of smoking decreased in black mine employees in all age groups (p<0.001); no such trend was seen for white mine employees. The proportion of light smokers increased significantly from 59.9% to 64.7%, with a corresponding significant decrease in the proportion of moderate and heavy smokers from 28.0% to 25.4%, and from 12.1% to 9.8%, respectively.Conclusion:This study showed a significant decrease in smoking prevalence over a relatively short period, despite the fact that there was no smoking cessation programme in the company. The decline can be largely attributed to the South African government’s antismoking initiative and supports the drive to continue to increase excise taxes on cigarette products. Nevertheless, the relatively high prevalence of smoking in some groups of mine employees highlights the need for workplaces to support the government’s initiatives to curb smoking by establishing smoking cessation and prevention programmes.
Physician assessment of patient smoking in Indonesia: a public health priority
Authors: Ng Nawi , Prabandari Yayi Suryo , Padmawati Retna Siwi , Okah Felix , Haddock C Keith , Nichter Mark , Nichter Mimi , Muramoto Myra , Poston Walker S C , Pyle Sara A , Mahardinata Nurazid , Lando Harry A 
Published: June 2007

Objective:To explore Indonesian physician’s smoking behaviours, their attitudes and clinical practices towards smoking cessation.Design:Cross-sectional survey.Setting:Physicians working in Jogjakarta Province, Indonesia, between October and December 2003.Subjects:447 of 690 (65%) physicians with clinical responsibilities responded to the survey (236 men, 211 women), of which 15% were medical faculty, 35% residents and 50% community physicians.Results:22% of male (n = 50) and 1% of female (n = 2) physicians were current smokers. Approximately 72% of physicians did not routinely ask about their patient’s smoking status. A majority of physicians (80%) believed that smoking up to 10 cigarettes a day was not harmful for health. The predictors for asking patients about smoking were being male, a non-smoker and a medical resident. The odds of advising patients to quit were significantly greater among physicians who perceived themselves as sufficiently trained in smoking cessation.Conclusions:Lack of training in smoking cessation seems to be a major obstacle to physicians actively engaging in smoking cessation activities. Indonesian physicians need to be educated on the importance of routinely asking their patients about their tobacco use and offering practical advice on how to quit smoking.