POS0408 TRANSFER OF HUMAN RHEUMATOID ARTHRITIS MONONUCLEAR CELLS INDUCES ARTHRITIS IN IMMUNODEFICIENT HLA-DR4 TRANSGENIC MICE

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease leading to erosive joint destruction. Although the exact pathogenesis is still elusive, the strong association of certain HLA class II molecules, such as HLA-DRB1*0401 (HLA-DR4), suggest involvement of CD4+ T cells (1,2). Mouse models of RA mimic specific aspects of the disease but are limited by the differences between human and murine immune systems.

Objectives

We aimed to establish a humanized mouse model (humice) carrying DR4+ RA PBMCs to study its role in the pathogenesis of RA without putting patients at risk.

Methods

Peripheral blood mononuclear cells (PBMC) of HLA-DR4 positive RA patients or controls were isolated and injected into NSG-Ab0 DR4 mice (NOD-scid IL2Rgammanull mice lacking MHC class II while expressing the human HLA-DR4) to create humice. Human immune cell composition within humice was profiled using flow cytometry. Development of RA was monitored by examination of the joints and micro computed tomography analysis. Joints were analysed by histology regarding pannus formation, bone erosions, cartilage damage, and human cell infiltration.

Results

Transfer of RA PBMCs induced arthritis in humice recapitulating hallmarks of RA including immune cell infiltration, pannus formation, increased osteoclastogenesis, cartilage damage, and bone erosions. Arthritis was dependent on the implanted human cells as NSG-Ab0 DR4 mice without transfer of human PBMCs did not develop arthritis. T-helper 1 (Th1) cells, dominated the human immune cell composition in humice, while regulatory T cells (Tregs) were diminished compared to donor PBMC composition. Mice humanized with cells from RA patients were more likely to develop inflammatory joint disease, compared to healthy HLA-DR4 positive controls (RA donor 70% vs. healthy control 20%, p=0.00196). CTLA-4 Ig treatment prevented arthritis development in this model (p=0.0055).

Conclusion

Humice carrying DR4+ RA PBMCs developed an RA-like erosive joint disease driven by the implanted human immune system. The data implies that the disease can be transferred by arthritogenic cells found in the peripheral blood of RA patients. This model will allow new insights into the pathogenesis of RA.

References

[1]Goulielmos GN, Zervou MI, Myrthianou E, Burska A, Niewold TB, Ponchel F. Genetic data: The new challenge of personalized medicine, insights for rheumatoid arthritis patients. Gene Available from: http://www.ncbi.nlm.nih.gov/pubmed/26869316

[2]Holoshitz J. The rheumatoid arthritis HLA–DRB1 shared epitope. Curr Opin Rheumatol Available from: http://www.ncbi.nlm.nih.gov/pubmed/20061955

Disclosure of Interests

None declared.

POS1063 STAT PHOSPHORYLATION AS A MARKER FOR DISEASE ACTIVITY IN PATIENTS WITH PSORIATIC ARTHRITIS: AN EXPLORATIVE ANALYSIS

Background

Numerous cytokines that influence disease activity in psoriatic arthritis (PsA) are modulators of the Janus Kinases/Signal Transducers and Activators of Transcription (JAK/STAT) pathway. The JAK1/STAT1/STAT3/STAT5 network can drive the expansion of Th17 and regulatory T cells via proinflammatory cytokines in PsA joints,[1], [2] while hyperphosphorylation of STAT3 in immune cells has previously been shown to promote PsA pathogenesis through the Interleukin (IL)-23/IL-17/IL-22 axis.[3] Therefore, the phosphorylation status of STAT molecules in leucocytes of PsA patients may indicate active disease and could potentially guide treatment with JAK inhibitors.

Objectives

To analyse phosphorylated STAT (pSTAT) levels of circulating leucocyte subsets in PsA patients with active and inactive disease

Methods

Whole blood was drawn on consecutive PsA patients fulfilling the CASPAR criteria[4] to perform flow cytometry analysis using the BD FACSLyric platform. Disease activity was assessed using the Disease activity for psoriasis arthritis (DAPSA) score.[5] All steps from storage of drawn blood to cell fixation were performed at 4°C to prevent auto-activation of leucocytes. The geometric mean fluorescence intensities (gMFI) of pSTATs in granulocytes, monocytes, B cells and CD4+/- naïve/memory T cells were compared between patients with moderate to high (MoDA/HDA) and remission to low disease activity (REM/LDA). Correlation analysis between gMFIs and DAPSA scores were performed.

Results

Forty-two patients (female ratio: 0.48) with established PsA (median ± standard deviation, age: 56 ± 12.54 years, disease duration: 8.50 ± 7.10 years) were included in this study. Twenty-one percent of patients were in MoDA/HDA, while the remaining 79% were in REM/LDA. Patients in MoDA/HDA showed significantly higher pSTAT3 levels in CD4+ naïve (gMFI median ± standard deviation: 284.5 ± 79.9 vs 238 ± 92.9, p = 0.011), CD4- naïve (297 ± 107.5 vs 238 ± 98.4, p = 0.04), CD4+ memory (227 ± 62.9 vs 190.5 ± 72.2, p = 0.009) and CD4- memory T cells (209 ± 66.8 vs 167.0 ± 64.9, p = 0.036). On the other hand, PsA patients in remission or low disease activity displayed higher pSTAT1 levels in granulocytes (2509 ± 1887 vs 1330.5 ± 784.1, p = 0.040) and monocytes (255 ± 230 vs 144 ± 62.5, p = 0.049). Positive correlations were found between DAPSA scores and pSTAT3 in CD4+ naïve and memory T cells (Spearman’s correlation coefficient rho (ρ) = 0.5, p = 0.0012 and ρ = 0.47, p = 0.0025 resp.) whereas pSTAT1 in granulocytes and monocytes were negatively correlated with the DAPSA scores (ρ = -0.45, p = 0.0074 and ρ = -0.34, p = 0.05).

Conclusion

Differential phosphorylation of STAT3 and STAT1 molecules in circulating leucocyte subsets indicates PsA disease activity. Further studies to examine the value of STAT phosphorylation patterns guiding JAK inhibitor therapy are underway.

References

[1]U. Fiocco et al., “Ex vivo signaling protein mapping in T lymphocytes in the psoriatic arthritis joints,” J. Rheumatol., vol. 93, pp. 48–52, 2015, doi: 10.3899/jrheum.150636.

[2]S. K. Raychaudhuri, C. Abria, and S. P. Raychaudhuri, “Regulatory role of the JAK STAT kinase signalling system on the IL-23/IL-17 cytokine axis in psoriatic arthritis,” Ann. Rheum. Dis., vol. 76, no. 10, pp. e36–e36, 2017.

[3]E. Calautti, L. Avalle, and V. Poli, “Psoriasis: A STAT3-centric view,” International Journal of Molecular Sciences, vol. 19, no. 1. MDPI AG, Jan. 06, 2018, doi: 10.3390/ijms19010171.

[4]W. Taylor, D. Gladman, P. Helliwell, A. Marchesoni, P. Mease, and H. Mielants, “Classification criteria for psoriatic arthritis: Development of new criteria from a large international study,” Arthritis Rheum., vol. 54, no. 8, pp. 2665–2673, 2006, doi: 10.1002/art.21972.

[5]M. M. Schoels, D. Aletaha, F. Alasti, and J. S. Smolen, “Disease activity in psoriatic arthritis (PsA): Defining remission and treatment success using the DAPSA score,” Ann. Rheum. Dis., vol. 75, no. 5, pp. 811–818, 2016, doi: 10.1136/annrheumdis-2015-207507.

Disclosure of Interests

Barbara Dreo: None declared, Daniel Ruben Pietsch: None declared, Rusmir Husic Speakers bureau: MSD, Lilly und Abbvie, Angelika Lackner: None declared, Johannes Fessler: None declared, Janine Rupp: None declared, Anirudh Subramanian Muralikrishnan: None declared, Jens Thiel Speakers bureau: GSK, BMS, AbbVie, Novartis, Consultant of: GSK, Novartis, Grant/research support from: BMS, Martin Stradner Speakers bureau: Eli Lilly, Pfizer, MSD, BMS, AbbVie, Janssen, Consultant of: Eli Lilly, AbbVie, Janssen, Philipp Bosch Grant/research support from: Pfizer

AB0471 FIRST SYMPTOMS AT THE ONSET OF PRIMARY SJÖGREN’S SYNDROME – THE PATIENTS’ PERSPECTIVE OF A SNEAKY DISEASE

Background

Primary Sjögren Syndrome (PSS) is an autoimmune disorder with a diverse spectrum of clinical manifestations ranging from sicca symptoms to severe systemic organ involvement. Little is known about the symptoms at the onset of PSS, as these are often ignored by both, patients and physicians leading to a substantial delay of diagnosis.

Objectives

The aim of this study was to investigate patients’ recollection of the first symptoms before diagnosis of PSS in qualitative interviews. The second aim was to verify and quantify these aspects in a representative cohort.

Methods

All PSS patients fulfilled the EULAR/ACR 2016 classification criteria. In the first part of the study, consecutive PSS patients were recruited for individual, semi-structured interviews. A discussion guide with five open-ended questions was developed to explore patients’ experiences on the onset of PSS. All interviews were audio-recorded and transcribed verbatim, and an inductive thematic data analysis was performed using MAXQDA software (VERBI, Berlin, Germany).

In the second part, the identified aspects of the qualitative analysis were grouped to a checklist with ten items. Patients were asked to complete the checklist before their routine clinical assessment.

Results

One-hundred and thirty-four patients participated in the study. The qualitative part was completed by 31 PSS patients; 90.3% (n=28) were female and patients had a mean disease duration of 6.9 years (±5.7(SD)) and a mean age of 58.1 years (±12.6).

Four different major aspects emerged of how patients experienced the beginning and first symptoms of PSS: (1) sicca symptoms started after initial swelling of parotis and/or lymph nodes (2) “Classic” PSS symptoms (fatigue, pain, dryness): patients reported wandering joint pain before diagnosis with a long time apart from first symptoms until diagnosis. Patients described joint pain, chronic malaise, and fatigue over months. (3) Hormonal changes (e.g. after birth, hysterectomy) or infections before the onset of PSS symptoms. (4) Slowly progressing discomfort due to sicca: patients reported a slow progression of symptoms with no initial recognition of sicca discomfort. In these patients recurrent dental problems and loss of teeth in the years prior to diagnosis was common.

In the second part of the study, the four themes were verified in an independent cohort of 103 PSS patients. Patients were 59.9 (±13.7) years old and six patients were male. The main symptom before diagnosis was dryness (n=77, 74.8%) with wandering joint pain (n=51, 49.5%) and fatigue (n=47, 45.6%). In 38.8% (n=40), patients reported a swelling/inflammation of the parotid gland at the onset of disease.

Conclusion

We identified four themes describing the initial symptoms of PSS. Raising awareness of these symptoms among physicians and among the general public may allow earlier diagnosis of PSS.

Disclosure of Interests

None declared

POS1265 DISTURBED CELLULAR IMMUNITY FOLLOWING mRNA VACCINATION AGAINST COVID-19 IN PATIENTS WITH B-CELL DEPLETING THERAPY

Background

Immunocompromised patients are considered high-risk and prioritized for vaccination against COVID-19 (1). Furthermore, vaccination-induced CD4 and CD8 T-cell responses have been suggested to have a protective role in COVID-19 (2). If T-cell responses are diminished after vaccination in immunocompromised individuals is not known to date.

Objectives

To investigate cellular immunity following mRNA vaccination against COVID-19 in healthy individuals and patients undergoing B-cell depletion therapy.

Methods

In this interim analysis of the CoVVac study (NCT04858607), we analyzed T-cell responses in autoimmune patients treated with B-cell depleting therapy (BD, n=41) and age-matched healthy controls (HCs, n=50) 3-4 weeks after the second dose of mRNA vaccination against COVID-19. Therefore, we isolated PBMCs and stimulated them with a peptide pool covering the spike protein in vitro. Reactive CD4 and CD8 T-cells were determined by staining for IFNg, TNFa, IL-2 and GzmB by flow cytometry. Anti-SARS-CoV-2 antibody assays targeting the receptor-binding domain (RBD) or trimeric S protein (TSP) were performed to elucidate concomitant B-cell responses.

Results

We observed significant alterations in anti-SARS-CoV-2 antibody responses in our cohort, the frequency of IFNg+ and IL-2+ CD4 and CD8 T-cells was similar in BD patients and controls. On the other hand, TNFa+ CD4 T-cells were significantly enriched in healthy controls versus BD patients (p=0.017) and correlated significantly with antibody titres (p=0.003). Similarly, GzmB+ CD8 T-cells were significantly diminished in our patient cohort (p<0.001) and also showed a significant correlation with antibody titres (p<0.001). Overall, the frequency of GzmB+ CD8 T-cells correlated very well with reactivity of T-cell subsets for other cytokines. This effect, however, is lost in the BD cohort. No difference was observed in the frequency of TNFa+ CD8 T-cells between the groups.

Only 21 (42%) healthy individuals and 14 (34%) patients showed reactive T-cells for all the cytokines tested. This observation is mainly explained by a lack of cytokine production of CD8 T-cells in 26 (52%) HCs and 27 (66%) BD patients. In turn, 22 (44%) HCs and 17 (42%) patients didn’t show any IL-2 producing CD8 cells. Of note, only 2 (4%) of HCs showed no GzmB+ CD8 T-cells whereas the number increased to 15 (37%) of BD individuals (p<0.001). In contrast, 42 (84%) HCs as well as 32 (78%) of patients showed production of all IFNg, TNFa and IL-2 in CD4 T-cells.

Conclusion

Our data suggest that most patients with B-cell depleting therapy are able to mount T-cell responses similar to those of healthy individuals while a minority of these patients did not show complete immunity against SARS CoV-2. Further analyses are needed to better understand a possible link of B-cell depletion therapy and CD8 T-cell responses.

References

[1]Shields AM, Burns SO, Savic S, Richter AG; UK PIN COVID-19 Consortium. COVID-19 in patients with primary and secondary immunodeficiency: The United Kingdom experience. J Allergy Clin Immunol. 2021 Mar;147(3):870-875.e1.

[2]Angyal, A., Longet, S., Chalk, J., 2022. T-cell and antibody responses to first BNT162b2 vaccine dose in previously infected and SARS-CoV-2-naive UK health-care workers: a multicentre prospective cohort study. The Lancet Microbe 3

Disclosure of Interests

None declared

Deprivation amplification due to structural disadvantage? Playgrounds as important physical activity resources for children and adolescents

OBJECTIVES

The deprivation amplification hypothesis postulates that the socially disadvantaged are exposed to further structural deprivation by their residential environment such that social inequalities are therefore amplified. To date, no publication has investigated deprivation amplification solely using playgrounds; the present health geography study investigates this hypothesis with regard to the availability of playgrounds in a typical large German city.

STUDY DESIGN

Between July 2016 and January 2017, all playgrounds in the city of Mannheim, Germany, were identified and evaluated by systematic audits. The playground attributes such as availability, accessibility, surface area, and provided amenities were operationalized using well-established, validated instruments.

METHODS

Geo-information about playgrounds was digitalized in ArcGIS 10.2-10.4 and linked to socioeconomic indicators on the meso-level, that is, on the level of 44 social areas. Availability and accessibility of playgrounds were quantified by calculating kernel density and Euclidean distance, respectively. Playground surface area and equipment provided were linked to the number of children and adolescents in the particular social area. The association between availability and accessibility of playgrounds and area-level indicators were assessed using bivariate and multiple Poisson regressions on the meso-level.

RESULTS

In the city of Mannheim, which covers 145 km² and is home to 311,000 inhabitants, 271 playgrounds were identified. Bivariate and multiple analyses showed no association between availability and accessibility of playgrounds and area-level indicators. However, significant negative associations were found in the bivariate analyses between playground area and amenities provided per child and various area-level indicators, but not in multiple models.

CONCLUSIONS

Children are provided with different opportunities to play and to be physically active, depending upon the population density of their social neighborhood. At least in our study area, many socially disadvantaged families are forced to move to densely populated areas for economic reasons. Against that background, the phenomenon of 'deprivation amplification' was not confirmed for availability and accessibility of playgrounds but for playground area and number of amenities provided.

Burden of Care of Various Infant Orthopedic Protocols for Improvement of Nasolabial Esthetics in Patients With CUCLP

OBJECTIVES

1. To evaluate the orthodontic burden of care of nasoalveolar molding (NAM) and modified McNeil for the treatment of patients with complete unilateral cleft lip and palate (CUCLP). 2. To compare the esthetic outcomes of each with those of centers not utilizing infant orthopedics (IO).

DESIGN

Retrospective cohort study.

SETTING

Institutional.

PARTICIPANTS

Four cohorts with repaired CUCLP (n = 149) from 3 centers.

INTERVENTIONS

Two cohorts were treated in the same center and had either traditional infant orthopedics (TIO) or NAM and 2 were treated in centers not employing IO.

MAIN OUTCOME MEASURES

Burden of care data for the IO groups were compared using t tests. Frontal and profile photographs at approximately age 5 were collected for ratings of nasolabial esthetics, using a modification of the Asher-McDade method. Intrarater and interrater reliabilities were determined using weighted κ statistics. Median ratings were compared using a Kruskal-Wallis test.

RESULTS

The burden of care of NAM was significantly greater than TIO for both the number of visits (9.9 vs 6.6, [ P < .001]); and treatment duration (127 vs 112 days, [ P < .05]). Significant differences in nasolabial esthetic ratings were noted among the 3 centers. No significant differences were observed in the nasolabial esthetic outcomes between the NAM and TIO groups.

CONCLUSIONS

1. NAM required more visits and longer overall duration compared with TIO. 2. The center employing IO showed favorable nasolabial esthetics compared to those not utilizing IO. 3. No significant differences were found in the nasolabial esthetics of patients who have received NAM compared with TIO.

An Intercenter Comparison of Dental Arch Relationships and Craniofacial Form Including a Center Using Nasoalveolar Molding

Objective:

To compare dental arch relationship and craniofacial morphology of patients with CUCLP in pre-adolescence from five cleft centers including a center using NAM.

Design:

Retrospective cohort study.

Setting:

Five cleft centers in North America.

Patients:

One hundred eighty-two subjects with repaired CUCLP from the five cleft centers participated in the craniofacial form study. One hundred forty-eight subjects from four of the five centers participated in the dental arch relationship study.

Methods:

Digital dental models were assessed using the GOSLON Yardstick. Eighteen cephalometric measurements were performed. Measurement means, by center, were compared. Analysis of variance and Tukey-Kramer analysis were used to compare GOSLON scores and cephalometric measurements.

Results:

The center that performed neither PSOT (including NAM) nor primary bone grafting exhibited the most favorable mean GOSLON score. The same center also showed the highest mean SNA, ANB, and ANS-N-Pg angles. However, the mean ANB and ANS-N-Pg angles were not significantly different from those of the center using NAM. No statistically significant differences were seen for mandibular prominence, vertical dimensions, or dental inclinations. The center with NAM also showed a significantly smaller nasoform angle than two of the four other centers.

Conclusion:

The centers that used NAM and other forms of PSOT did not have better dental arch relationships or craniofacial morphology compared with the centers that performed only primary lip repair. However, this study was not designed to investigate the cause-and-effect relationship between specific outcomes and particular features of those protocols.

Altered soluble mediator levels and systemic lupus erythematosus-specific Connective Tissue Disease Screening Questionnaire (CSQ) scores differentiate unaffected relatives of lupus patients from healthy individuals with no family history of SLE (CCR4P.214)

Identifying populations at risk of SLE who remain unaffected would provide insights for potential disease prevention. Using a unique resource of SLE patient family members, first degree relatives (FDRs) of SLE patients (n = 154) with plasma samples available from previous genetic studies and who remained unaffected at follow-up evaluation (mean time = 6.8 years) were matched to healthy individuals unrelated to SLE patients (Controls). FDRs and Controls provided clinical and demographic information, and completed screening questionairres at baseline (BL) and follow-up (FU). BL and FU plasma samples were assessed for autoantibody production and soluble mediators. FDRs had significantly higher BL and FU CSQ scores (p&lt;0.0001), but no difference in the number of positive autoantibodies compared to Controls. FDRs had significant (p &lt; 0.01) increases in 38 (of 52) soluble mediators at BL and FU, including IFN-associated chemokines, TNFR ligands, and regulatory mediators (p&lt;0.002). Levels of MIP-1α (p=0.008), MIG (p=0.019), GROα (p=0.001), ICAM-1 (p=0.007), and VEGF (p=0.004), along with CSQ scores (p=0.010), best distinguished FDRs from Controls in logistic regression models. These alterations are present despite lack of progression to classified SLE, suggesting that multiple perturbations in immune-mediated inflammatory processes present in FDRs of SLE patients may be offset by inhibitory factors.

Pharmacotherapy guidelines for the aged by family doctors for the use of family doctors

Part C of the guideline is preceded by Part B General Pharmacology IJCPT. 2008; 46: 600 - 617. Included in Part C are practical guidelines for improving the therapy of some age-specific diseases and problems commonly encountered in general practice. The article in this issue is dedicated to the therapy of Dementia and M. Parkinson. Further guidelines for the other age specific diseases and problems named above will be published in the following issues of IJCPT. An important feature of these guidelines are the inclusion of Levels of Evidence and of the Strength of Recommendations for the therapy which are shown when reliable studies are available. (For both see levels of evidence at the end of this article.).

Das Leitlinien-Clearingverfahren COPD. Empfehlungen für eine nationale Leitlinie

In order to promote the care of patients with COPD in Germany a national guideline clearing project was initiated jointly by autonomous corporate bodies of the German health care system. Following a systematic search of literature data bases between 1992 and 2002, 20 guidelines were identified that met the inclusion criteria and were evaluated with the German Checklist for Methodological Guideline Appraisal. Following this, a multidisciplinary expert group appointed by the German Guideline Clearinghouse (Leitlinien-Clearingstelle im Arztlichen Zentrum fur Qualitat in der Medizin, AZQ) reviewed the suitability of these guidelines for the use in the German health care system. Referring to methodological aspects, criteria were best met by the guideline of the Veteran's Health Administration/Department of Defense (US), followed by the one of the Deutsche Atemwegsliga and the Deutsche Gesellschaft fur Pneumologie. Aiming at the production respectivly a revision of a German national guideline for COPD the expert group agreed on recommendations organized in 19 chapters. Among others these strengthened the role of a precise definition of COPD based primarily on the pathogenesis, of a subtle description of all diagnostic and therapeutic tools and of a detailed description of quality assurance and quality management. The feasability of recommendations were demonstrated by examples chosen from the evaluated guidelines. Additionally the presented findings may be used as steering tools in the German Health care system.

[The German guideline clearing-project on bronchial asthma - part 2: recommendations and key topics for a national guideline on bronchial asthma]

BACKGROUND

In order to promote the quality of asthma management in Germany, a national asthma guidelines clearing project was initiated in 2000 by the German Guidelines Clearinghouse (Sponsors: German Medical Association (GMA), National Association of the Statutory Health Insurance Physicians (NASHIP), German Hospital Federation, Federal Association of the Statutory Sickness Funds. This Part shows the key topics which should be dealt with in a German guideline on bronchial asthma.

SUMMARY POINTS

For quality promotion of bronchial asthma management in Germany, the development of a national evidence-based guideline, using the internationally accepted quality criteria for clinical practice guidelines, was recommended by an expert group of the German Guideline Clearinghouse. The experts identified and peer-reviewed 16 out of 54 guidelines, which might be useful as benchmarks and examples for a German asthma guideline. From the peer review results, the expert group identified 18 key topics for a national asthma guideline.

[The German guideline clearing-project on bronchial asthma-part 1: Methodology and results of formal appraisal]

BACKGROUND

In order to promote quality of asthma management in Germany, a national asthma guidelines clearing project was initiated in 2000 by the German Guidelines Clearinghouse (Sponsors: German Medical Association (GMA), National Association of the Statutory Health Insurance Physicians (NASHIP), German Hospital Federation, Federal Association of the Statutory Sickness Funds. Part 1 of this article shows the methodology and the results of the appraisal, part 2 (to be published) shows the key topics which should be dealt with in a german guideline on bronchial asthma.

OBJECTIVES

To identify and compare evidence-based, high-quality German- and English language asthma guidelines as benchmarks for ongoing guideline development and implementation programmes. To disseminate information about asthma guidelines developed in accordance with current methodological know-how. To identify and consent key topics for a national evidence-based guideline for Germany.

METHODS

Search procedure, formal appraisal: Systematic search using literature databases (XMED, incl. Medline and Embase) and English-/German-language guideline databases (via www. leitlinien.de), published between January 1990 and March 2000. Abstract screening of the search results according to the inclusion criteria (n = 54 of a total of 502 hits). Methodological guideline evaluation of 16 guidelines using the German checklist for methodological guideline appraisal. Appraisal of guidelines' contents: Peer review of guidelines with the following inclusion criteria: Bronchial Asthma-general, German and English language, based in references published later than 1994, new guideline or actual update. Peer review was performed by a multidisciplinary focus group of EBM experts (clinical and ambulatory settings). No expert was involved in guideline production during the review period.

RESULTS

Methodological appraisal: 16 out of guidelines were in accordance with the formal minimal standard with a wide range within the following domains: "description of the development process", "declaration of authors' independence", "explicit link between recommendations and the supporting evidence", "management options", "tools for implementation". The focus group recommended for future national asthma guidelines to rely on the following procedures: (1) to formulate the recommendations using standardized, clearly described consensus methods basing on evidence retrieved and selected in a systematic way (2) to prove links between recommendations and supporting evidence (3) to develop guideline versions for health care professionals as well as for consumer/patients (4) to develop guideline-based education tools (5) to ensure periodical updates of the asthma guideline (6) to consider the methodological recommendations and to give reasons for deviations from the methodological recommendations. APPRAISAL OF GUIDELINES CONTENT: None of the guidelines identified comprised information about all of the following key topics considered to be relevant for a German national guideline by the focus group: (1) intended guideline users/goals, (2) definition (3) cause of disease, (4) form of disease, (5) severity, (6) diagnosis, (7) therapeutic goals, (8) prevention, (9) pharmacotherapy, (10) non-pharmacotherapy, (11) therapy control and compliance, (12) emergency treatment, (13) rehabilitation, (14) comorbidity, (15) special aspects, (16) coordination of care, (17) quality assurance/quality management, (18) implementation.

SUMMARY POINTS

For quality promotion of bronchial asthma management in Germany, the development of a national evidence-based guideline, using the internationally accepted quality criteria for clinical practice guidelines, was recommended by an expert group of the German Guideline Clearinghouse. The experts identified and peer-reviewed 16 out of 54 guidelines, which might be useful as benchmarks and examples for a German asthma guideline. From the peer review results, the expert group identified 18 key topics for a national asthma guideline.

Spatial resolution and noise tradeoffs in pinhole imaging system design: a density estimation approach

This paper analyzes the tradeo between spatial resolution and noise for simple pinhole imaging systems with photon-counting detectors. We consider image recovery algorithms based on density estimation methods using kernels that are based on apodized inverse filters. This approach allows a continuous-object, continuous-data treatment of the problem. The analysis shows that the pinhole size that minimizes the estimate variance for a specied reconstructed spatial resolution is directly proportional to that spatial resolution. For a Gaussian pinhole, the variance-minimizing full-width half maximum (FWHM) of the pinhole equals the desired object spatial resolution divided by p2. Simulation results confirm this conclusion empirically. The general approach is a potentially useful addition to the collection of tools available for imaging system design.

Effect of ischemia and reperfusion on oxidative processes in the large colon and jejunum of horses

OBJECTIVE

To evaluate and compare oxidative processes during ischemia and reperfusion of the equine large colon and jejunum.

ANIMALS

2 groups of 6 anesthetized horses undergoing a terminal procedure.

PROCEDURE

Isolated loops of large colon and jejunum were subjected to 2 hours of ischemia, followed by 2 hours of reperfusion. Tissue specimens were taken after 105 minutes of ischemia and 10, 30, 60, and 120 minutes of reperfusion. Mesenteric arterial and venous blood samples were collected for blood gas analysis at the same times to evaluate ischemia and reoxygenation. Oxidative processes in tissues were evaluated by use of biochemical assays for malondialdehyde and conjugated dienes and by use of the manganese-diaminobenzidine histochemical technique for localized superoxide generation.

RESULTS

Significant quantities of malondialdehyde and conjugated dienes were detected in the jejunum after 60 and 120 minutes of reperfusion together with histochemical evidence of superoxide generation in jejunal endothelial cells and in submucosal neutrophils and eosinophils.

CONCLUSIONS

Oxidative processes do not appear to have an appreciable role in inducing damage in the equine large colon during reperfusion after 2 hours of ischemia. In contrast to the jejunum, reactive oxygen species are not generated in measurable quantities in the large colon subsequent to ischemia and reperfusion.

CLINICAL RELEVANCE

Free radical scavengers are not likely to be effective in prevention of equine colonic mucosal deterioration after ischemia.

Efficacy of convective removal of plasma mediators of endotoxic shock by continuous veno-venous hemofiltration

Continuous veno-venous hemofiltration (CVVH) has been reported to provide beneficial effects during endotoxic shock. This experiment was designed to determine if selective removal of plasma mediators occurs during CVVH and if plasma concentrations of these mediators are reduced. A swine endotoxic-shock model with three groups was used (lipopolysaccharide (LPS) only (n = 6); LPS followed by CVVH (n = 6); and LPS followed by sham CVVH (n = 4). Plasma and filtrate samples were collected at frequent intervals for 5 h. Lactic acid (LA), eicosanoids [prostacyclin (6-keto PGF1 alpha), thromboxane (TxB2), and prostaglandin E2 (PGE2)] and tumor necrosis factor (TNF) were measured in plasma and filtrate. Plasma concentrations of 6-keto PGF1 alpha, TxB2, TNF, and LA were not significantly different in any group. LA, PGE2, 6-keto PGF1 alpha, and TXB2 concentrations were similar in filtrate and plasma. TNF did not move across the membrane into the filtrate, CVVH, as used in this experiment, did not significantly reduce plasma concentrations of any of these mediators.

Leukotriene C4 disposition and metabolism in the anesthetized and endotoxemic dog

The metabolism and disposition of tritiated leukotriene C4, [3H]-LTC4, were studied in control dogs and endotoxin-treated dogs. Radioactivity was monitored in plasma, bile, and urine for 4.5 hr after an IV bolus of [3H]-LTC4. A decreased recovery of radioactivity in bile and urine was observed in the endotoxin-treated dogs. Cumulative [3H]-LTC4 metabolic patterns in bile and urine were determined by reverse-phase high-performance liquid chromatography (RP-HPLC) separation. Three primary metabolites, [3H]-LTD4, [3H]-LTE4, and a polar metabolite, (0.15-0.19)LT, accounted for most of the total bile radioactivity. The same primary metabolites were found for endotoxin-treated dogs and in similar relative amounts. [3H]-LTE4 and the polar metabolite (0.15-0.21)LT were the primary metabolites found in urine, but no N-acetyl LTE4 was found in bile or urine for either group. Plasma incubation of [3H]-LTC4 revealed heat-sensitive dipeptidase and glutamyl transpeptidase activity with significant production of [3H]-LTD4 and [3H]-LTE4 after 5- and 30-min incubation. Pharmacokinetic analysis using the two-compartment open model revealed an increased distribution phase rate constant (alpha) and distribution phase half-life [t1/2(alpha)], and decreased clearance (ClB), volume of distribution [Vd(ss) and Vd(area)] and elimination rate microconstant (Kel) of tritiated leukotrienes for endotoxin-treated dogs. This analysis along with the maintained higher plasma levels of tritiated leukotrienes, [3H]-LTs, in endotoxin-treated dogs suggests that endotoxin caused a decreased body clearance and less peripheral tissue penetration of [3H]-LTs. Collectively, these results indicate that the metabolism of LTC4 to LTD4 and LTE4, but not N-acetyl LTE4, in dogs was similar to that reported for man, pig, and monkey but dissimilar to rat. Endotoxin did not affect the types or relative amounts of metabolites found in bile or urine but appears to affect the disposition of [3H]-LTs by decreasing clearance and distribution.

Hereditary junctional mechanobullous disease in a foal

Mechanobullous disease was diagnosed in a male Belgian foal that had sloughed hooves at 30 hours and at 6 and 12 days of age. Histologic and electron microscopic studies disclosed that lesions were the result of separation of the basal epithelial cell layer from the lamina densa of the basement membrane zone along the lamina lucida. Results of immunofluorescence on tissue specimens were negative for immunoglobulin deposition. The breeding history of the foal's dam indicated that the foal was produced from breeding of the mare to its full sibling stallion. This same mare had produced a female foal, sired by a different stallion, which also had sloughed hooves during the first 2 weeks of life and had similar histologic and electron microscopic changes. This newly recognized disease of horses most closely resembles junctional-type epidermolysis bullosa described in human beings.

Ectopic ureter managed by unilateral nephrectomy in two female horses

Unilateral ureteral ectopia was diagnosed in three-year-old and 10-month-old fillies exhibiting urinary incontinence since birth. In one case reimplantation of the ureter onto the bladder was planned but considered to be impractical intra-operatively. Unilateral nephrectomy was performed successfully in both cases which alleviated the urinary incontinence. Both horses had normal urinary function postoperatively and became healthy, serviceable animals.