Studies on the mechanism of bacterial resistance to complement-mediated killing. II. C8 and C9 release C5b67 from the surface of salmonella minnesota S218 because the terminal complex does not insert into the bacterial outer membrane

The mechanism for consumption of terminal complement components and release of bound components from the surface of serum-resistant salmonella minnesota S218 was studied. Consumption of C8 and C9 by S218 occurred through interaction with C5b67 on the bacterial surface because C8 and C9 were consumed when added to S218 organisms previously incubated in C8-deficient serum and washed to remove all C5b67 on the bacterial surface because C8 and C9 were consumed when added to S218 organisms previously incubated in C8- deficient serum and washed to remove al but cell bound C5b67. Rapid release of (125)I C5 and (125)I C7 from the membrane of S218 was dependent on binding of C8 because (125)I C5 and (125)I C7 deposition in C8D serum was stable and was twofold higher in C8D than in PNHA, and addition of purified C8 or C8 and C9 to S218 previously incubated in C8D serum caused rapid release of (125)I C5 and (125)I C7 from the organism. Analysis by sucrose density gradient ultracentrifugation of the fluid phase from the reaction of S218 and 10 percent PNHS revealed a peak consistent with SC5b-9, in which the C9:C7 ratio was 3.3:1, but the NaDOC extracted bound C5b-9 complex sedimented as a broad peak with C9:C7 of less than 1.2:1. Progressive elution of C5b67 and C5b-9 from S218 but not serum-sensitive S. minnesota Re595 was observed with incubation in buffers of increasing ionic strength. Greater than 90 percent of the bound counts of (125)I C5 or (125)I C9 were released from S218 by incubation in 0.1 percent trypsin, but only 57 percent of (125)I C9 were released by treatment of Re595 with trypsin. These results are consistent with the concept that C5b-9 forms on the surface of the serum-sensitive S. minnesota S218 in normal human serum, but the formed complex is released and is not bactericidal for S218 because it fails to insert into hydrophobic outer membrane domains.     

Reliable gastric closure after natural orifice translumenal endoscopic surgery (NOTES) using a novel automated flexible stapling device

Background  Reliable closure of the translumenal incision is one of the main challenges facing natural orifice translumenal endoscopic surgery (NOTES). This study aimed to evaluate the use of an automated flexible stapling device (SurgASSIST) for closure of the gastrotomy incision in a porcine model. Methods  A double-channel gastroscope was advanced into the stomach. A gastric wall incision was made, and the endoscope was advanced into the peritoneal cavity. After peritoneoscopy, the endoscope was withdrawn into the stomach. The SurgASSIST stapler was advanced orally into the stomach. The gastrotomy edges were positioned between the opened stapler arms using two endoscopic grasping forceps. Stapler loads with and without a cutting blade were used for gastric closure. After firing of the stapler to close the gastric wall incision, x-ray with contrast was performed to assess for gastric leakage. At the end of the procedure, the animals were killed for a study of closure adequacy. Results  Four acute animal experiments were performed. The delivery and positioning of the stapler were achieved, with technical difficulties mostly due to a short working length (60 cm) of the device. Firing of the staple delivered four rows of staples. Postmortem examination of pig 1 (when a cutting blade was used) demonstrated full-thickness closure of the gastric wall incision, but the cutting blade caused a transmural hole right at the end of the staple line. For this reason, we stopped using stapler loads with a cutting blade. In the three remaining animals (pigs 2–4), we were able to achieve a full-thickness closure of the gastric wall incision without any complications. Conclusions  The flexible stapling device may provide a simple and reliable technique for lumenal closure after NOTES procedures. Further survival studies are currently under way to evaluate the long-term efficacy of gastric closure with the stapler after intraperitoneal interventions. Presented in part at the Society of American Gastrointestinal Endoscopic Surgeons (SAGES) Annual Meeting, Las Vegas, Nevada, April 2007.     

Topical corticosteroids in psoriasis: strategies for improving safety

Corticosteroids are a mainstay of topical therapy for psoriasis. While efficacious and relatively safe when used carefully, the potential for side effects, notably skin atrophy and adrenal suppression, have been associated with excesses in potency, prolonged or widespread use. The International Psoriasis Council Working Group on Topical Therapy has reviewed the efficacy and safety of topical corticosteroids and recommends strategies for safe, long‐term use of these agents.     

Measurement of autoantibodies using multiplex methodology in patients with systemic lupus erythematosus

Autoantibodies are central to the diagnosis and assessment of systemic lupus erythematosus (SLE). A recent technique for the measurement of autoantibodies utilizes addressable laser bead immunoassay technology (BioPlex 2200) which permits the simultaneous detection of multiple autoantibodies and improved efficiency due to the shorter time to perform the assay and low volume of test samples and reagents. In the current study we have compared this technique to more traditional measures of autoantibody detection. The clinical and laboratory data and stored serum samples from the enrollment visit into a long-term lupus registry at a single academic medical center were used. Sera were examined for a panel of autoantibodies using the BioPlex ANA screen. The results were compared to the historical data on autoantibody profiles using indirect immunofluorescence (IIF) and ELISA. The association with global and organ specific SLE disease activity (nephritis) was also examined. The study consisted of 192 patients who were predominantly female (87%) and Caucasian (91%) with mean disease duration of 8.8 years. The frequency of ANA and anti-dsDNA by IIF and ELISA was 81.3% and 46.6% respectively and was higher than that found with BioPlex (75.5% and 31.8%). The latter detected a higher proportion of patients with autoantibodies to Sm (7.5% vs 16.7%), RNP (21.8% vs 24.0%), Ro (37.4% vs 41.7) and La (13.9% vs 23.4%). Overall agreement between assays varied between 71.4% and 92.5%. Additional autoantibodies identified by BioPlex were anti-chromatin antibodies which were similar in frequency to anti-dsDNA antibodies (33.9% and 31.8% respectively). There was a low frequency of anti-ribosomal P (6.8%), anti-Scl-70 (5.2%), anti-centromere B (3.7%) and anti-Jo-1 (0.5%). Several autoantibodies revealed significant associations with SLEDAI scores but in a multivariate analysis the only autoantibodies that approached statistical significance were anti-Sm (p = 0.094) measured by ELISA and anti-dsDNA (p = 0.082) measured by BioPlex. There was no association between any of the autoantibodies regardless of the method of detection and cumulative organ damage scores. Fifty-three patients (27.6%) had lupus nephritis of which 17 (32%) had active nephritis at the time of autoantibody determination. There was no significant association between a positive ANA (IIF) and any autoantibodies detected by ELISA with either the cumulative occurrence of lupus nephritis or active nephritis. In contrast, there was an association between BioPlex detected anti-dsDNA with the cumulative occurrence of nephritis (p = 0.074) which reached statistical significance with active nephritis at the time of antibody testing (p = 0.012). This was confirmed by multivariate analysis (p = 0.047). These results suggest reasonable agreement between the detection of lupus autoantibodies by ELISA and BioPlex. The latter demonstrated a better correlation with lupus nephritis.     

Manpower in Canadian academic rheumatology units: current status and future trends. Canadian Council of Academic Rheumatologists

OBJECTIVE: To examine manpower and activity profiles of attending staff, and enrollment in training programs over 3 years in academic rheumatology units in Canada. METHODS: In 1998, the Canadian Council of Academic Rheumatologists (CCAR) established a database to annually monitor trends in manpower, activity profiles, and recruitment in 15 academic rheumatology units in Canada. Information was also collected on residents pursuing subspecialty training in rheumatology. RESULTS: Between 1998 and 2000, the total number of rheumatologists increased from 157 (137 adult; 20 pediatric) to 162 (139 adult; 23 pediatric). Male to female ratio was about 2:1 and mean age increased from 48 to 49 years. About 60% of rheumatologists held fulltime positions within their academic units. In the year 2000, 57% of individuals had a substantial commitment (> or = 50% time) to clinical care activities compared to 17% for research and 3% for teaching. There were 21 unfilled positions, mainly full-time in adult rheumatology, across 12 centers. A substantial commitment (> or = 50% time) for research was identified in 11 of the unfilled positions, for clinical care activities in 6, and for teaching in one. Significant barriers to recruitment as identified by 11 centers were lack of suitable applicants (9), financial resources (5), and physical resources (3). From 1998 to 2000 the number of trainees in pediatric and adult rheumatology fell from 38 to 29 and the number of active training programs from 12 to 11. The mean age of trainees was 30-32 years, with equal representation for males and females. Over the 3 years studied, funding of trainees was provided by government (range 41-51% of trainees), The Arthritis Society (21-26%), and alternative sources (23-38%). Based on current recruitment, anticipated changes in population growth, and increased prevalence of rheumatic diseases, there will be a 64% shortfall in rheumatologists required in Canada by 2026. CONCLUSION: Rheumatology manpower in Canadian academic units needed to fulfill responsibilities in delivery of clinical services and academic programs is inadequate. Enrollment in rheumatology training programs is falling and is insufficient to meet the present and future manpower needs for patients with rheumatic diseases in Canada.