Playing tactics, contextual variables and offensive effectiveness in English Premier League soccer matches. A multilevel analysis

The aim of this study was to investigate the combined effects of tactical and contextual indicators on achieving offensive penetration and scoring opportunities in English Premier League (EPL) soccer matches. A total of 1971 team possessions from 20 random matches were evaluated by means of multidimensional observation. The EPL matches had a great proportion of fast attacks (36.0%) followed by combinative (29.6%), direct attacks (24.1%) and counterattacks (9.5%). Multilevel logistic regression models revealed that counterattacks (OR = 3.428; 95% CI: 2.004–5.864; P<0.001) were more effective to create goal scoring opportunities than combinative attacks, while direct attacks showed to be less effective (OR = 0.472; 95% CI: 0.264–0.845; P<0.05). Playing at home increased the probability (OR = 1.530; 95% CI: 1.097–2.135; P<0.05) of creating goal scoring opportunities compared with playing away. These findings show the multifactorial character of soccer and how different contextual and tactical indicators can influence the creation of offensive penetration and goal scoring opportunities in the English Premier League.

The effect of arm-crank exercise training on power output, spirometric and cardiac function and level of autonomy in persons with tetraplegia

Studies on the effects of exercise training in persons with cervical spinal cord injury (CSCI) are scarce. The aim of this study was to determine the effect of an 8-week stationary arm-crank exercise (ACE) training programme on the level of autonomy, exercise performance, pulmonary functional parameters and resting heart rate variability (HRV) in persons with CSCI. Quadriplegia Index of Function (QIF), arm-crank peak power output (Ppeak), spirometric variables, and HRV indices were measured before and after the training programme in a group of 11 persons with CSCI. ACE training increased Ppeak in both groups (p < 0.05), whereas maximum voluntary ventilation (MVV) and low frequency HRV (LF) improved only in the lower CSCI group (p < 0.05). Moreover, QIF and Ppeak were significantly correlated before (r = 0.88; p < 0.01) and after (r = 0.86; p < 0.01) the training period. However, no significant changes were found in the level of autonomy (QIF) as a result of the intervention. Therefore, stationary ACE training appears to be a feasible and effective method for aerobic exercise in persons with tetraplegia and a short-term intervention is able to significantly improve exercise capacity, cardiac autonomic regulation and respiratory muscle endurance, regardless of the absence of significant immediate changes in the level of autonomy.

Effect of Match Location, Team Ranking, Match Status and Tactical Dimensions on the Offensive Performance in Spanish 'La Liga' Soccer Matches

The aim of this paper was to study the combined effects of tactical and contextual dimensions on achieving offensive performance in open play possessions from Spanish "La Liga" soccer matches. 1860 team possessions from 20 random matches were evaluated by means of multidimensional observation. Multilevel regression models were constructed to predict the probability to achieve offensive performance according to the tactical and contextual dimensions registered in each possession. Performing penetrative actions after recovering the ball (OR = 1.497; 95% CI: 1.022-2.192; P < 0.05), and progressing by fast attacks (OR = 3.588; 95% CI: 2.045-6.294; p < 0.001) or counterattacks (OR = 7.097; 95% CI: 3.530-14.269; P < 0.001) was more effective to create scoring opportunities than performing a non-penetrative action and progressing by combinative attack, respectively. Also, progressing by long possessions (OR = 5.057; 95% CI: 2.406-10.627; p < 0.001) was more effective than progressing by short possessions to create scoring opportunities. As for contextual dimensions, multivariate analyses showed how playing at home and against high-ranked opponents registered more likelihood of achieving offensive penetration, although no associations were found in the production of scoring opportunities. Tactical dimensions as initial penetration, type of attack and possession length played an important role on achieving offensive penetration and goal scoring opportunities in Spanish Soccer "La Liga".

"REOFUT" as an Observation Tool for Tactical Analysis on Offensive Performance in Soccer: Mixed Method Perspective

Performance analysis in complex sports like soccer requires the study of the influence of the interaction between both teams during the game on final performance. The mixed methods approach involves the collection, analysis, and interpretation of qualitative and quantitative data for the same purpose and within the framework of the same study. To build certain observation tools, mixed methods are necessary in order to take advantage of integration between qualitative and quantitative elements. The aim of this study was to develop a new no standard observation tool to analyze soccer offensive performance considering not only the observed team but also some aspects of the opponent behavior, as well as to test its reliability. The process consisted in expert meetings and exploratory observations. Experts carried out several design and re-design steps of the observation tool to its final form which includes two macro-criteria and 31 dimensions. The basic unit of analysis was the "team possession" and the main aims of study were: (a) technical, tactical and spatial characteristics of the start, the development and the end of the team possession and its offensive performance, (b) the behavior of the observed team just after losing the ball possession and its defensive performance. Inter-observer and intra-observer analysis were carried out and kappa coefficient was calculated to test the observation tool reliability and improve the quality of data. Results indicate that optimal inter and intra-reliability levels obtained in this work are high enough as for suggesting that the observation tool for offensive performance in soccer (REOFUT) could be an adequate tool for analyzing offensive play actions and their performance in soccer.

New distribution record of Epipompilus aztecus (Cresson, 1869) (Hymenoptera: Pompilidae) in the Brazilian Pantanal

Epipompilus aztecus (Cresson, 1869) was registered in South America in 2010. The aim of this paper is to report the first record of E. aztecus in the Brazilian Pantanal. Two female individuals of E. aztecus were collected in the northern portion of the Brazilian Pantanal in Mato Grosso State during November 2015. This new record of E. aztecus represents a range extension for the species.

Environmental Heterogeneity in Parasitoid-Host Interaction for Mutillidae (Hymenoptera: Apocrita)

Environmental heterogeneity is a major factor influencing the spatial distribution of organisms. Due to intimate relationships with their hosts, parasitic insects are inclined to be even more sensitive to variations. This study aimed to verify the relationship between spatial distribution of Mutillidae, potential hosts, and the effect of heterogeneity in the distribution of both, testing the hypotheses: i) the spatial distribution of mutillids depends on the distribution of hosts and ii) variation in environmental heterogeneity affects the distribution of both. Sampling was conducted in four fragments of the Cerrado. We collected Hymenopteran specimens from 25 plots of one hectare using 18 Malaise traps throughout one year, totalizing 32,400 trap-hours. Female Mutillidae were hand collected at all sampling points, for a total of 450 man-hours. At each hectare plot, we obtained the environmental variables from nine plots of 25 m² A total of 1,089 individuals were collected (Apidae: 311; Crabronidae: 165; Shpecidae: 84; Vespidae: 229) belonging to 127 species of potential hosts (bees and wasps) and 300 individuals (42 species) of Mutillidae. Leaf-litter depths showed significant relation in host-parasitoid distribution. The spatiotemporal distribution followed the predator-prey model for Mutillidae, and environmental heterogeneity was a factor that determined the structure of the host-parasitoid community. The results suggest an intense relationship between the Mutillidae and Crabronidae, as well as Sphecidae and two Apidae subfamilies (Halictinae and Colletinae). These families and subfamilies present behavior in which they build nests in aggregations even each female being solitary. Crabronidae is considered the best potential host for Mutillidae.

Effect of the Game Design, the Goal Type and the Number of Players on Intensity of Play in Small-Sided Soccer Games in Youth Elite Players

The aim of this study was to compare the effects of game design modification, the type of the goal and the number of players on the intensity of play in small-sided soccer games (SSGs) in youth elite players. Twenty young soccer players (age 13.7 ± 0.5 years, body mass 57.4 ± 7.8 kg, body height 1.67 ± 7.8 m, maximal heart rate 201.1 ± 8.2 beats/min) performed three types of SSGs (possession play (PP) vs. regular goals (RG) vs. small goals (SG)) in both four-a-side and six-a-side formats. The heart rate responses were recorded and analysed as an indicator of the intensity of play. The four-a-side format obtained higher intensity of play than six-a-side for PP (p<0.05), but not for SG and RG. SG showed higher intensity of play than RG for four-a-side (p<0.001), but not for six-a-side. PP registered higher intensity of play than RG (p<0.05), but not than SG in four-a-side, whereas in six-a-side no differences were found between the three formats. In conclusion, the modification of variables such as the number of players, the game design and the type of the goal influences the intensity of play in small-sided soccer games in youth players.

Subcutaneous abatacept versus intravenous abatacept: a phase IIIb noninferiority study in patients with an inadequate response to methotrexate

OBJECTIVE

To compare the efficacy and safety of subcutaneous (SC) and intravenous (IV) abatacept.

METHODS

In this phase IIIb double-blind, double-dummy, 6-month study, patients with rheumatoid arthritis (RA) and inadequate responses to methotrexate were randomized to receive 125 mg SC abatacept on days 1 and 8 and weekly thereafter (plus an IV loading dose [∼10 mg/kg] on day 1) or IV abatacept (∼10 mg/kg) on days 1, 15, and 29 and every 4 weeks thereafter. The primary end point for determining the noninferiority of SC abatacept to IV abatacept was the proportion of patients in each group meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at month 6. Other efficacy end points, immunogenicity, and safety were also assessed.

RESULTS

Of 1,457 patients, 693 of 736 (94.2%) treated with SC abatacept and 676 of 721 (93.8%) treated with IV abatacept completed 6 months. At month 6, 76.0% (95% confidence interval 72.9, 79.2) of SC abatacept-treated patients versus 75.8% (95% confidence interval 72.6, 79.0) of IV abatacept-treated patients achieved an ACR20 response (estimated difference between groups 0.3% [95% confidence interval -4.2, 4.8]), confirming noninferiority of SC abatacept to IV abatacept. Onset and magnitude of ACR responses and disease activity and physical function improvements were comparable between the SC and IV abatacept-treated groups. The proportions of adverse events (AEs) and serious AEs over 6 months were 67.0% and 4.2%, respectively, in the SC abatacept-treated group and 65.2% and 4.9%, respectively, in the IV abatacept-treated group, with comparable frequencies of serious infections, malignancies, and autoimmune events between groups. SC injection site reactions (mostly mild) occurred in 19 SC abatacept (IV placebo)-treated patients (2.6%) and 18 IV abatacept (SC placebo)-treated patients (2.5%). Abatacept-induced antibodies occurred in 1.1% of SC abatacept-treated patients and 2.3% of IV abatacept-treated patients.

CONCLUSION

SC abatacept provides efficacy and safety comparable with that of IV abatacept, with low immunogenicity and high retention rates, consistent with the established IV abatacept profile. Rates of injection site reactions were low. SC abatacept will provide additional treatment options, such as an alternative route of administration, for patients with RA.

An evaluation of commercial DNA extraction kits for the isolation of bacterial spore DNA from soil

AIMS

To evaluate six commercial DNA extraction kits for their ability to isolate PCR-quality DNA from Bacillus spores in various soil samples.

METHODS AND RESULTS

Three soils were inoculated with various amounts of Bacillus cereus spores to simulate an outbreak or intentional release of the threat agent Bacillus anthracis. DNA was isolated from soil samples using six commercial DNA extraction kits. Extraction and purification efficiencies were assessed using a duplex real-time PCR assay that included an internal positive control. The FastDNA(®) SPIN kit for Soil showed the highest DNA extraction yield, while the E.Z.N.A.(®) Soil DNA and PowerSoil(®) DNA Isolation kits showed the highest efficiencies in removing PCR inhibitors from loam soil extracts.

CONCLUSIONS

The results of this study suggest that commercially available extraction kits can be used to extract PCR-quality DNA from bacterial spores in soil. The selection of an appropriate extraction kit should depend on the characteristics of the soil sample and the intended downstream application.

SIGNIFICANCE AND IMPACT OF THE STUDY

  The results of this study aid in the selection of an appropriate DNA extraction kit for a given soil sample. Its application could expedite sample processing for real-time PCR detection of a pathogen in soil.

Age-related increase in xanthine oxidase activity in human plasma and rat tissues

This study assessed the role of xanthine oxidase in vascular ageing. A positive correlation between xanthine oxidase activity and age was found in human plasma. Similar results were found in rat plasma. Xanthine oxidase expression and activity in homogenates from the aortic wall were significantly higher in samples from old rats than in their young counterparts (p < 0.01). In rat skeletal muscle homogenates both xanthine oxidase expression and activity showed a similar age-related profile. Superoxide production by xanthine oxidase in aortic rings was higher in aged rats. Uric acid, the final product of xanthine oxidase has been proposed as a risk factor for coronary heart disease and an independent marker of worse prognosis in patients with moderate-to-severe chronic heart failure. These results give a possible explanation for this correlation and underscore the role of xanthine oxidase in ageing.

Abatacept inhibits progression of structural damage in rheumatoid arthritis: results from the long-term extension of the AIM trial

OBJECTIVE

Assess the effect of abatacept on progression of structural damage over 2 years in patients with rheumatoid arthritis who had an inadequate response to methotrexate.

METHODS

539 patients entered an open-label extension of the AIM (Abatacept in Inadequate responders to Methotrexate) trial and received abatacept. Radiographic assessment of the hands and feet was performed at baseline, year 1 and year 2. At year 2, each patient's radiographs were scored for progression blinded to sequence and treatment allocation.

RESULTS

In patients treated with abatacept for 2 years, greater reduction in progression of structural damage was observed in year 2 than in year 1. The mean change in total Genant-modified Sharp scores was reduced from 1.07 units in year 1 to 0.46 units in year 2. Similar reductions were observed in erosion and joint space narrowing scores. Following 2 years of treatment with abatacept, 50% of patients had no progression of structural damage as defined by a change in the total score of < or =0 compared with baseline. 56% of patients treated with abatacept had no progression during the first year compared with 45% of patients treated with placebo. In their second year of treatment with abatacept, more patients had no progression than in the first year (66% vs 56%).

CONCLUSIONS

Abatacept has a sustained effect that inhibits progression of structural damage. Furthermore, the mean change in radiographic progression in patients treated with abatacept for 2 years was significantly lower in year 2 versus year 1, suggesting that abatacept may have an increasing disease-modifying effect on structural damage over time.

Efficacy and safety of abatacept or infliximab vs placebo in ATTEST: a phase III, multi-centre, randomised, double-blind, placebo-controlled study in patients with rheumatoid arthritis and an inadequate response to methotrexate

OBJECTIVES

This double-blind trial evaluated the efficacy and safety of abatacept or infliximab vs placebo. The primary objective of this study was to evaluate the mean change from baseline in Disease Activity Score (based on erythrocyte sedimentation rates; DAS28 (ESR)) for the abatacept vs placebo groups at day 197.

METHODS

Patients with rheumatoid arthritis (RA) and an inadequate response to methotrexate (MTX) were randomised 3:3:2 to abatacept ( approximately 10 mg/kg every 4 weeks, n = 156), infliximab (3 mg/kg every 8 weeks, n = 165), or placebo (every 4 weeks, n = 110) and background MTX. Safety and efficacy were assessed throughout the study.

RESULTS

Similar patient demographics and clinical characteristics were present at baseline between groups, with mean scores of approximately 1.7 for HAQ-DI and 6.8 for DAS28 (ESR). At 6 months, mean changes in DAS28 (ESR) were significantly greater for abatacept vs placebo (-2.53 vs -1.48, p<0.001) and infliximab vs placebo (-2.25 vs -1.48, p<0.001). For abatacept vs infliximab treatment at day 365, reductions in the DAS28 (ESR) were -2.88 vs -2.25. At day 365, the following response rates were observed for abatacept and infliximab, respectively: American College of Rheumatology (ACR) 20, 72.4 and 55.8%; ACR 50, 45.5 and 36.4%; ACR 70, 26.3 and 20.6%; low disease activity score (LDAS), 35.3 and 22.4%; DAS28-defined remission, 18.7 and 12.2%; good European League Against Rheumatism (EULAR) responses, 32.0 and 18.5%; and Health Assessment Questionnaire Disability Index (HAQ-DI), 57.7 and 52.7%. Mean changes in physical component summary (PCS) were 9.5 and 7.6, and mental component summary (MCS) were 6.0 and 4.0, for abatacept and infliximab, respectively. Over 1 year, adverse events (AEs) (89.1 vs 93.3%), serious AEs (SAEs) (9.6 vs 18.2%), serious infections (1.9 vs 8.5%) and discontinuations due to AEs (3.2 vs 7.3%) and SAEs (2.6 vs 3.6%) were lower with abatacept than infliximab.

CONCLUSIONS

In this study, abatacept and infliximab (3 mg/kg every 8 weeks) demonstrated similar efficacy. Overall, abatacept had a relatively more acceptable safety and tolerability profile, with fewer SAEs, serious infections, acute infusional events and discontinuations due to AEs than the infliximab group.

TRIAL REGISTRATION NUMBER

NCT00095147.

Efficacy and safety of the selective co-stimulation modulator abatacept following 2 years of treatment in patients with rheumatoid arthritis and an inadequate response to anti-tumour necrosis factor therapy

OBJECTIVE

To evaluate the safety and efficacy of abatacept during 2 years of the ATTAIN (Abatacept Trial in Treatment of Anti-TNF INadequate responders) trial in patients with rheumatoid arthritis.

METHODS

Patients completing the 6-month, double-blind period were eligible to enter the long-term extension; patients received abatacept approximately 10 mg/kg, plus disease-modifying antirheumatic drugs. Safety and efficacy (American College of Rheumatology (ACR) criteria responses, DAS28 (C-reactive protein), HAQ-DI, SF-36, Medical Outcomes Study Sleep Problems Index, fatigue VAS) were assessed through 2 years.

RESULTS

317 patients (218 from the abatacept and 99 from the placebo group) entered and 222 (70%) completed 18 months of long-term extension treatment. The incidence and type of adverse events were consistent between the double-blind and cumulative (double-blind plus long-term extension) periods. Rates of serious adverse events were 25.6 and 23.4 per 100 patient-years in the double-blind versus cumulative period. At 6 months and 2 years, using non-responder analyses, ACR responses in abatacept-treated patients were: ACR 20, 59.4% and 56.2%; ACR 50, 23.5% and 33.2%; ACR 70, 11.5% and 16.1%; HAQ-DI responses were 54.4% and 47.9%. At 6 months and 2 years, using post-hoc as-observed analyses, the percentage of patients (95% confidence interval) achieving DAS28 (C-reactive protein) low disease activity score (< or = 3.2) and DAS28 (C-reactive protein)-defined remission (< 2.6) increased from 18.3% (13.0, 23.5) to 32.0% (24.6, 39.4) and 11.1% (6.8, 15.3) to 20.3% (13.9, 26.6). Clinically meaningful improvements in SF-36, pain, fatigue and sleep problems were also maintained throughout the 2 years of abatacept treatment.

CONCLUSION

No unique safety observations were reported during open-label exposure. Improvements in the signs and symptoms of rheumatoid arthritis, physical function and health-related quality of life observed after 6 months, were maintained throughout the 2 years in this population with difficult-to-treat disease.

TRIAL REGISTRATION NUMBER

NCT00124982.

Safety of the selective costimulation modulator abatacept in rheumatoid arthritis patients receiving background biologic and nonbiologic disease-modifying antirheumatic drugs: A one-year randomized, placebo-controlled study

OBJECTIVE

To assess the safety of abatacept, a selective costimulation modulator, in patients with active rheumatoid arthritis (RA) who had been receiving > or =1 traditional nonbiologic and/or biologic disease-modifying antirheumatic drugs (DMARDs) approved for the treatment of RA for at least 3 months prior to entry into the study.

METHODS

This was a 1-year, multicenter, randomized, double-blind, placebo-controlled trial. Patients were randomized 2:1 to receive abatacept at a fixed dose approximating 10 mg/kg by weight range, or placebo.

RESULTS

The abatacept and placebo groups exhibited similar frequencies of adverse events (90% and 87%, respectively), serious adverse events (13% and 12%, respectively), and discontinuations due to adverse events (5% and 4%, respectively). Five patients (0.5%) in the abatacept group and 4 patients (0.8%) in the placebo group died during the study. Serious infections were more frequent in the abatacept group than in the placebo group (2.9% versus 1.9%). Fewer than 4% of patients in either group experienced a severe or very severe infection. The incidence of neoplasms was 3.5% in both groups. When evaluated according to background therapy, serious adverse events occurred more frequently in the subgroup receiving abatacept plus a biologic agent (22.3%) than in the other subgroups (11.7-12.5%).

CONCLUSION

Abatacept in combination with synthetic DMARDs was well tolerated and improved physical function and physician- and patient-reported disease outcomes. However, abatacept in combination with biologic background therapies was associated with an increase in the rate of serious adverse events. Therefore, abatacept is not recommended for use in combination with biologic therapy.

Improved health-related quality of life for rheumatoid arthritis patients treated with abatacept who have inadequate response to anti-TNF therapy in a double-blind, placebo-controlled, multicentre randomized clinical trial

OBJECTIVE

Rheumatoid arthritis (RA) patients who have inadequate response to anti-tumour necrosis factor (TNF) therapy currently have treatment options that are limited and less than optimal in their risk-to-benefit ratio. Abatacept provides a new generation of RA medications that has previously been demonstrated to have positive clinical outcomes with this population. The current study sought to demonstrate the efficacy of abatacept on quality of life (QoL) for RA patients with inadequate response to anti-TNF therapy.

METHODS

Patients were entered into a double-blind, placebo-controlled, multicentre randomized clinical trial, with 258 patients randomized to abatacept + disease-modifying anti-rheumatic drugs (DMARDs) and 133 patients randomized to placebo + DMARDS. The QoL was measured with the Short Form Health Survey (SF-36), Health Assessment Questionnaire (HAQ) and fatigue visual analogue scale, and was analysed with basic (ANOVA, chi-square) and multigroup growth curve techniques to assess differential change over time.

RESULTS

Treatment group QoL improved significantly more than placebo on the HAQ and fatigue indices, as well as seven of the eight SF-36 scales and SF-36 physical and mental summary scores. Improvement rate was faster for abatacept than for placebo on the QoL measures, and the improvements from abatacept related to normal levels of QoL on many domains.

CONCLUSION

Clinically relevant benefits of abatacept over placebo are discussed regarding improving QoL. Importantly, the larger rate of change for abatacept over placebo provides clinicians with a medication that can lead to meaningful changes in a patient's life within a few weeks, even when the patient previously failed anti-TNF therapy.

beta7 Integrin expression is not required for the localization of T cells to the intestine and colitis pathogenesis

beta7 Integrins have been shown to have an important role in the localization of T cells to the intestine. Utilizing two different experimental mouse models of inflammatory bowel disease (IBD), this study was undertaken to determine if beta7 integrin expression is critical for T cell localization to the intestine and colitis pathogenesis. Transfer of CD4+ CD45RBhigh cells into immunodeficient mice results in colitis. To examine the role of beta7 integrins, donor cells were obtained from beta7 integrin gene-deficient animals and disease induction was examined following transfer into severe combined immunodeficiency (SCID) mice. Additionally, beta7 integrin gene-deficient animals were crossed to IL-2-deficient mice and the onset of spontaneous colitis that normally occurs in IL-2-deficient animals was examined. No differences in the onset or severity of spontaneous colitis was noted in animals that were deficient in both beta7 integrin and IL-2. In contrast, the onset of colitis in recipients of T cells from beta7 integrin-deficient donors was delayed significantly. In mice receiving beta7 integrin negative cells, the initial lack of colitis appeared to correlate with fewer numbers of CD3+beta7 integrin -/- donor lymphocytes present in the host colon. The eventual development of disease, however, was associated with increased numbers of donor beta7 integrin -/- lymphocytes. These results show that beta7 integrin expression is not absolutely required for T cell localization to the intestine and colitis pathogenesis.

Mice with combined disruption of Gpx1 and Gpx2 genes have colitis

Glutathione peroxidase (GPX)-1 and gastrointestinal (GI) epithelium-specific GPX (GPX-GI), encoded by Gpx1 and Gpx2, provide most GPX activity in GI epithelium. Although homozygous mice deficient in either the Gpx1 or Gpx2 gene appeared to be normal under standard housing conditions, homozygous mice deficient in both genes, double-knockout (KO) mice, had symptoms and pathology consistent with inflammatory bowel disease. These symptoms included a high incidence of perianal ulceration, growth retardation that started around weaning, and hypothermia that resembled that observed in calorie-restricted mice, even though the double-KO mice in our study were allowed to eat ad libitum. The growth retardation and hypothermia were components of cachexia, which is fatal in a high percentage of mice. Histological examination revealed that the double-KO mice had a high incidence of mucosal inflammation in the ileum and colon but not in the jejunum. Elevated levels of myeloperoxidase activity and lipid hydroperoxides were also detected in colon mucosa of these homozygous double-KO mice. These results suggest that GPX is essential for the prevention of the inflammatory response in intestinal mucosa.

Assessment of polycrystalline graphites as sorbents for solid-phase microextraction of nonionic surfactants

Two polycrystalline graphites (pencil lead and glassy carbon) were used as sorbents for solid-phase microextraction of a nonionic alkylphenol ethoxylate surfactant (Triton X-100). Analyses were performed by reversed-phase HPLC-fluorescence detection. The presence of the benzene ring in the congeners of Triton X-100 also allowed their direct detection at lambda(ex) = 230 nm and lambda(em) = 310 nm. Variables such as time of adsorption, time of desorption and concentration of surfactant in water were evaluated. The method limit of detection was found to be 0.5 microg/l for Triton X-100, with a linear dynamic range of 0.5-150 microg/l. Results were compared to those obtained using polymeric fibers such as PDMS/DVB and Carbowax/TPR. The chemical resistance and low cost of the polycrystalline graphites are advantageous over commercially available SPME fibers.

Systemic activation and antigen-driven oligoclonal expansion of T cells in a mouse model of colitis

Transfer of CD4+CD45RBhigh T cells into immunodeficient mice results in both the expansion of the transferred T cells and colitis. Here we show that colitis pathogenesis requires expression of MHC class II molecules by the immune-deficient host. Analysis of the TCRbeta repertoire of the cells found in the large intestine of diseased mice revealed a population with restricted TCR diversity. Furthermore, nucleotide sequence analysis demonstrated the selection for particular CDR3beta amino acid sequence motifs. Collectively, these data indicate that the expansion of T cells in the intestine and colitis pathogenesis are likely to require the activation of Ag-specific T cells, as opposed to nonspecific or superantigen-mediated events. There is relatively little overlap, however, when the TCR repertoires of different individuals are compared, suggesting that a number of Ags can contribute to T cell expansion and the generation of a T cell population in the intestine. Surprisingly, many of the expanded clones found in the large intestine also were found in the spleen and elsewhere, although inflammation is localized to the colon. Additionally, donor-derived T cells appear to be activated in both the intestine and the spleen at early time points after cell transfer. Together, these results strongly suggest that disease induction in this model involves either the early and systemic activation of antigen-specific T cells or the rapid dispersal of T cells activated at a particular site.

Generation of intestinal mucosal lymphocytes in SCID mice reconstituted with mature, thymus-derived T cells

Transfer of peripheral lymph node lymphocytes to SCID mice leads to the long term establishment of mucosal T lymphocytes within the epithelium and lamina propria of the small and large intestines. Analysis of engrafted intraepithelial lymphocytes (IEL) showed that they had acquired a surface phenotype that in several respects is typical of IEL. In addition, the functional profile of engrafted IEL derived from lymph node T cells was similar to that of normal IEL; as the donor-derived T cells exhibited a strong cytolytic activity, a poor proliferative response to mitogenic stimuli, and a tendency to home and expand specifically in the intestine upon transfer to secondary SCID recipients. Optimal engraftment of intestinal T cells required bacterial flora, as the number of lymphocytes was greatly reduced in SCID recipients with a reduced flora. These results demonstrate that mature, thymus-derived T cells can migrate to the intestine and become functionally specialized to the intestinal milieu. The acquisition of phenotypic markers characteristic of the intestinal microenvironment by engrafted cells suggests that T cell migration of lymphocytes to the SCID intestine is not aberrant, but it may reflect processes that are ongoing in immunocompetent mice. Furthermore, these data suggest that the homing and/or expansion of typical, thymus-derived T cells in the intestine may be driven by luminal Ags such as those derived from bacterial flora.

Immunosuppressive drugs in the treatment of inflammatory bowel disease

Immunosuppressive (IS) drugs are an important option in the management of both forms of inflammatory bowel disease (IBD): Crohn's disease and ulcerative colitis. As the experience of using these agents in the treatment of IBD has increased and more data have become available on their efficacy, these drugs are being used more extensively. The principle drugs used in clinical practice at this time include: azathioprine (AZA) and its metabolite 6-mercaptopurine (6-MP), methotrexate, and cyclosporin A. AZA and 6-MP are generally considered the first line immunosuppressive agents. These drugs are effective and generally well tolerated by the majority of patients started on them, enabling many patients to avoid the predictable side effects of steroid therapy. Because of their extensive use, it is important that clinicians involved in the care of IBD patients are familiar with the IS drugs used to treat IBD, especially AZA and 6-MP.

Altered immune responses in interleukin 10 transgenic mice

Interleukin (IL)-10 is a pleiotropic cytokine which inhibits a broad array of immune parameters including T helper cell type 1 (Th1) cytokine production, antigen presentation, and antigen-specific T cell proliferation. To understand the consequences of altered expression of IL-10 in immune models of autoimmune disease, the response to infectious agents, and the response to tumors, we developed transgenic mice expressing IL-10 under the control of the IL-2 promoter. Upon in vitro stimulation, spleen cells from unimmunized transgenic mice secrete higher levels of IL-10 and lower amounts of IFN-gamma than do controls, although no gross abnormalities were detected in lymphocyte populations or serum Ig levels. Transfer of normally pathogenic CD4(+) CD45RBhigh splenic T cells from IL-10 transgenic mice did not cause colitis in recipient severe combined immunodeficiency mice. Furthermore, co-transfer of these transgenic cells with CD4(+) CD45RBhigh T cells from control mice prevented disease. Transgenic mice retained their resistance to Leishmania major infection, indicating that their cell-mediated immune responses were not globally suppressed. Lastly, in comparison to controls, IL-10 transgenic mice were unable to limit the growth of immunogenic tumors. Administration of blocking IL-10 mAbs restored in vivo antitumor responses in the transgenic mice. These results demonstrate that a single alteration in the T cell cytokine profile can lead to dramatic changes in immune responses in a manner that is stimulus dependent. These mice will be useful in defining differences in inflammatory conditions and cellular immunity mediated by IL-10.

Analysis of intestinal lymphocytes in mouse colitis mediated by transfer of CD4+, CD45RBhigh T cells to SCID recipients

Transfer of specific T lymphocyte subsets isolated from the spleens of healthy donor mice into immunodeficient SCID mice leads to chronic intestinal inflammation with characteristics similar to those of human inflammatory bowel disease (IBD). CD4+, CD45RBhigh cells cause disease, whereas CD4+, CD45RBlow and CD8+, CD45RBhigh cells do not. Despite this difference, we demonstrate that all three T cell populations reconstitute the intraepithelial and lamina propria compartments of both small and large intestines of SCID recipients. Therefore, infiltration of lymphocytes alone is not sufficient for disease development. CD4+ lymphocytes that have trafficked to the SCID intestine exhibit a phenotype characteristic of normal mucosal lymphocytes. This includes high expression of alpha E integrin and CD69, expression of CD8 alpha alpha homodimers in some of the intraepithelial lymphocytes, as well as low expression of CD62L and CD45RB. The phenotype of the infiltrating mucosal cells is indistinguishable, with respect to the cell surface markers tested, regardless of whether the starting donor population is CD45RBhigh or CD45RBlow. Severe inflammation is restricted primarily to the colon despite lymphocyte infiltration throughout the length of the intestine. This suggests that some property of the colon microenvironment contributes to inflammation. Consistent with this, transfer of CD4+, CD45RBhigh cells to SCID mice that have significantly reduced numbers of enteric flora results in attenuation of the wasting and colitis. Fewer numbers of donor lymphocytes are recovered from the intraepithelial and lamina propria compartments of reduced flora SCID mice. We hypothesize that the ability of pathogenic cells to traffic to the intestine and mediate colitis may be driven by T cell reactivity to bacteria or bacterial products.

Analysis of intestinal lymphocytes in mouse colitis mediated by transfer of CD4+, CD45RBhigh T cells to SCID recipients

Transfer of specific T lymphocyte subsets isolated from the spleens of healthy donor mice into immunodeficient SCID mice leads to chronic intestinal inflammation with characteristics similar to those of human inflammatory bowel disease (IBD). CD4+, CD45RBhigh cells cause disease, whereas CD4+, CD45RBlow and CD8+, CD45RBhigh cells do not. Despite this difference, we demonstrate that all three T cell populations reconstitute the intraepithelial and lamina propria compartments of both small and large intestines of SCID recipients. Therefore, infiltration of lymphocytes alone is not sufficient for disease development. CD4+ lymphocytes that have trafficked to the SCID intestine exhibit a phenotype characteristic of normal mucosal lymphocytes. This includes high expression of alpha E integrin and CD69, expression of CD8 alpha alpha homodimers in some of the intraepithelial lymphocytes, as well as low expression of CD62L and CD45RB. The phenotype of the infiltrating mucosal cells is indistinguishable, with respect to the cell surface markers tested, regardless of whether the starting donor population is CD45RBhigh or CD45RBlow. Severe inflammation is restricted primarily to the colon despite lymphocyte infiltration throughout the length of the intestine. This suggests that some property of the colon microenvironment contributes to inflammation. Consistent with this, transfer of CD4+, CD45RBhigh cells to SCID mice that have significantly reduced numbers of enteric flora results in attenuation of the wasting and colitis. Fewer numbers of donor lymphocytes are recovered from the intraepithelial and lamina propria compartments of reduced flora SCID mice. We hypothesize that the ability of pathogenic cells to traffic to the intestine and mediate colitis may be driven by T cell reactivity to bacteria or bacterial products.

[Helicobacter pylori at Hospital Santo Tomás]

We studied the incidence of infection with Helicobacter pylori in Panamanians with chronic dyspepsia, gastric or duodenal ulcer, gastritis or gastric cancer. The histopathology was positive in 54 (81%) of 66 patients; the urea test was positive in 52 (82.5%) of 63 cases; the impromptu was positive in 51 (79.6) of 64 patients; the endoscopic examination was positive in 64 (82.9%) of 77 examinations.

Insulin regulates the paracellular permeability of cultured intestinal epithelial cell monolayers

The T84 human colonic epithelial cell line retains the ability to produce secretagogue-responsive monolayer cultures with high transepithelial resistance when grown and maintained on collagen-coated permeable supports in media supplemented with 5% newborn calf serum. The addition of highly purified insulin to the basolateral but not the apical membrane side of established monolayers caused the transepithelial resistance to decline more than eightfold over a 3-4-d period. By comparing the transepithelial flux of 22Na with that of the extracellular space marker, [3H]mannitol, the decline in electrical resistance was shown to be due solely to an effect on tight junction-mediated paracellular permeability. The effect of insulin was dose dependent with a half-maximal effect at 3.9 ng/ml (approximately 0.7 nM) and fully reversible over a 10-d time course. Simultaneous addition of 2 microM cycloheximide prevented the insulin-induced decline in resistance; in fact, this combination caused a significant increase in electrical resistance. There was no effect on the short-circuit current response of insulin-treated monolayers to secretagogues so long as media was changed daily. While no gross morphological changes were apparent, there did appear to be a subtle condensation of the perijunctional actin ring as visualized using rhodamine-labeled phalloidin. These results demonstrate that insulin modulates the permeability of the occluding junction in T84 cell monolayers through a receptor mediated process which probably involves changes in protein synthesis and cytoskeletal structure. Insulin was also shown to produce similar effects on two other intestinal epithelial cell lines.

An evaluation of four techniques for condensation of three opaque porcelains

Opaque porcelain applied with the brush and hand vibration techniques resulted in smaller and fewer entrapped air bubbles within the fired opaque.

Comparison of fracture strength of porcelain-veneered-to-high noble and base metal alloys

Sixty crowns were cast from a commercial high noble and base metal alloy. The porcelain applied to the crowns was fired 10 times and fractured under gradual application of load. The fracture strength of the porcelain-veneered-to-base metal and high noble alloys subjected to repeated firings was compared. The results were: The fracture strength of porcelain-veneered-to-high noble alloys remained relatively constant for five firings but decreased significantly as the firings increased to 10. Ten firings did not significantly affect the fracture strength of porcelain-veneered-to-base metal alloys. Porcelain-veneered-to-base metal alloy crowns had a higher fracture strength compared with high noble alloy crowns.