Structural, Molecular and Immunological Properties of Linear B-Cell Epitopes of Ro60KD Autoantigen

Antibodies to Ro60KD protein are found with high frequency in sera from patients with systemic lupus erythematosus (SLE) and primary Sjögren's syndrome (pSS). Two major epitopes of the Ro60KD antigen, the TKYKQRNGWSHKDLLRSHLKP (169–190) and the ELYKEKALSVETEKLLKYLEAV (211–232), were synthesized and their antigenic and structural properties were studied. Using a large panel of SLE and pSS patients' sera, it was found that the anti-Ro60KD reactivity of both Ro60KD epitopes is rather limited (≈45%), although they retain their original disease specificity. The epitope p.169–190 possessed sequence similarity with the peptide RPDAEYWNSQKDLLEQKRGR, shared in the β-chain of different HLA-DR molecules, among them the HLA-DR3 (which is associated with anti-Ro/Sjögren's syndrome A (SSA) response in patients with SLE). The antigenicity of the HLA-DR3 RPDAEYWNSQKDLLEQKRGR peptide was found to be similar to the 169–190 homologous Ro60KD epitope, recognized mainly by SLE sera. Structural studies showed that the 211–232 Ro60KD epitope exhibits pronounced helical characteristics, while the 169–190 epitope and the HLA-DR3 homologous peptide possess a somewhat lower percentage of α-helix. A β-folded structure was identified in the latter two peptides. Although the diagnostic value of the reported Ro60KD epitopes seems to be rather limited, correlations with other ribonucleoprotein epitopes (La/Sjögren's syndrome B, Ro52KD) may prove complementary to each other and valuable in clinical use. The ordered structure of the HLA-DR3 homologous peptide, exposed to the autoantibody binding, may offer an initiative in further investigation of the role of the HLA haplotypes, associated with the anti-Ro/SSA response, in the autoimmune stimulus.     

Psychological well‐being and psychosocial work environment characteristics among emergency medical and nursing staff

The aim of this study was to determine if the effect of psychosocial work environment on psychological well‐being was different for doctors and nurses who work in emergency departments in Spain. A cross‐sectional survey was carried out among 945 emergency doctors and nurses staff from Spain. The outcome variable was the psychological well‐being measured by two dimensions of SF‐36 Health Survey (SF‐36) (mental health, vitality) and one dimension of Maslach's Burnout Inventory (emotional exhaustion). The explanatory variable was the psychosocial work environment evaluated according to Karasek and Johnson's demand‐control model that includes the dimensions of psychological demands, job control, supervisor social support and co‐workers' social support. The adjusted odds ratios and their 95 per cent confidence intervals were calculated by logistic regression. The prevalence of low vitality, bad mental health and high emotional exhaustion was higher among doctors than nurses. Exposure to high psychological demands increased the probability of low vitality, bad mental health and high emotional exhaustion among doctors and nurses. Low job control and low co‐workers' social support at work were associated with poor psychological well‐being only among doctors. Low job supervisors' social support increased the risk of bad mental health among doctors and of high emotional exhaustion among nurses. There is a different effect of psychosocial work environment on psychological well‐being between doctors and nurses. Copyright © 2007 John Wiley & Sons, Ltd.     

Transmission of hepatitis B virus from mother to child in Bamako-Mali]

Results of a study about mother-infant transmission of hepatitis B virus (HBV) confirm the high degree of positivity of HBV markers in Bamako, Republic of Mali. Among 372 sera of mother-newborn pairs, seroprevalence of HBs Ag has been around 11% in mothers. The lack of anti HBc IgM in all sera agree probably with a relative old contamination. Pre-S2 epitope marker has been found in more than 70% of HBs Ag positive mothers and 50% of their children. Large discordance has been noted between the prevalence rate of this marker and the HBe Ag and viral DNA, other markers of HBV replication. Further studies are necessary for the clear understanding of HBV transmission systems in our country.     

Rapid identification of Rhodococcus equi by a PCR assay targeting the choE gene

The actinomycete Rhodococcus equi is an important pathogen of horses and an emerging opportunistic pathogen of humans. Identification of R. equi by classical bacteriological techniques is sometimes difficult, and misclassification of an isolate is not uncommon. We report here on a specific PCR assay for the rapid and reliable identification of R. equi. It is based on the amplification of a fragment of the choE gene encoding cholesterol oxidase. The choE-based PCR was assessed by using a panel of strains comprising 132 isolates from different sources and of different geographical origins, all initially identified biochemically as R. equi, and 30 isolates of representative non-R. equi actinomycete species, including cholesterol oxidase producers. The expected 959-bp amplicon was observed only with R. equi isolates, as confirmed by sequencing of a variable region of the 16S RNA gene from a random sample of 20 PCR-positive isolates. All R. equi isolates gave a positive choE-based PCR result, which correlated with a high degree of conservation of the choE gene. Three of the 132 strains originally identified as R. equi were negative for the choE gene, and subsequent analysis of their 16S RNA gene sequences confirmed that they belonged to other bacterial species (Dietzia maris, Mycobacterium peregrinum, and Staphylococcus epidermidis). All non-R. equi isolates were negative by the choE-based PCR. ATCC 21387, the only known isolate of Brevibacterium sterolicum, gave a 959-bp amplicon whose DNA sequence was virtually identical to that of R. equi choE. Comparison of the 16S RNA genes indicated that ATCC 21387 should be considered an R. equi isolate.     

Epidemiology of vascular dementia: some results despite research limitations

Vascular dementia, the second most common dementia after Alzheimer disease, has great potential for prevention and treatment. Epidemiological data provide the basis for planning primary prevention and clinical trials. Nevertheless, general consensus on disease definition and diagnostic criteria are still not well defined. Despite these limitations, some results from the Kungsholmen project, an epidemiological longitudinal study of people 75 years and older, are presented here.     

Assessment of the Suitability of Phytotoxkit Plastic Vertical Containers Compared with Petri Dishes for Standard Seedling Growth Tests

This study compares two cultivation methods (Petri dishes vs. Phytotoxkit containers; tap water vs. Knop’s solution) for standard seedling growth tests. Seeds and young seedlings of Sinapis alba and Hordeum vulgare were used as study subjects and the adverse effect of Cd was assessed. Under testing conditions, only H. vulgare showed a significant decrease in seed germination in Petri dishes when tap water was used as the growth medium (70.8 % ± 46.4 %). No significant differences in IC₅₀ values were found in either plant type for root growth between plants cultivated in Phytotoxkit containers and those cultivated in Petri dishes. The same findings were confirmed for shoot growth in H. vulgare, but not in S. alba. Suitability of Phytotoxkit containers over traditionally used Petri dishes for phytotoxicity determination was confirmed by higher correlation coefficients for all tests.     

Clinical characteristics and long-term outcome in patients with heart failure complicating acute myocardial infarction

INTRODUCTION AND OBJECTIVES: To evaluate the clinical characteristics and prognosis of heart failure (HF) development in patients hospitalized for acute myocardial infarction (AMI). PATIENTS AND METHOD: Between May 1990 and March 2000, 836 consecutive patients were admitted with a diagnosis of AMI within 24 h of symptom onset. HF was defined as the presence of rales and a third heart sound with gallop, and evidence of pulmonary congestion on chest x-ray. It was diagnosed in 263 subjects (31.5%). RESULTS: The mean age of patients with HF (group 1) was 63.4 (11.4) years compared with 59.9 (11.6) years in those without HF (group 2) (P<.01). There were differences between groups 1 and 2 in history of diabetes (36% vs 20%; P<.001) or previous HF (9.2% vs 1.1%; P<.001). The reperfusion strategy used in patients with Q-wave infarction, with or without HF, was primary angioplasty in 15% and 14%, respectively (P=.81), and thrombolytic agents in 28% and 37%, respectively (P=.013). Patients with HF were more likely to develop recurrent angina (26.8% vs 19.6%; P=.02), pericarditis (17.5% vs 6.3%; P<.001), and atrial fibrillation (12.3% vs 5.1%; P<.01). In-hospital mortality in groups 1 and 2 was 15.6% and 2.3% (P<.001), respectively, and 10-year survival was 10% and 30%, respectively (P<.001). The variables associated with mortality were: age (HR=1.022; P<.001), hyperglycemia (HR=1.748 per 1.0-g/L increase; P<.001), leukocytosis (HR=1.035 per 1000-cell/.L increase; P<.001), and HF (HR=1.308; P=.028). CONCLUSIONS: AMI is still frequently complicated by HF, which increases short- and long-term morbidity and mortality. Heart failure, age, hyperglycemia, and leukocytosis at admission were independent predictors of mortality during follow-up.     

Clinically significant and biopsy-documented renal involvement in primary Sjögren syndrome

Clinically significant renal involvement in patients with primary Sj?gren syndrome (pSS) has been described previously only in isolated case reports. The prevalence and significance of the 2 described syndromes, interstitial nephritis (IN) and glomerulonephritis (GMN), are not well known. In a cohort of 471 patients with pSS who were followed for a mean of 10 years, 20 patients (4.2%) developed overt renal disease. Eighteen patients underwent a percutaneous renal biopsy; 2 patients declined. Ten patients had IN, 8 patients had GMN, and 2 patients presented with both entities. Glomerular histology disclosed changes compatible with membranoproliferative GMN in 5 patients and mesangial proliferative GMN in 4 patients. Patients with IN had a younger disease onset compared with patients with GMN (mean, 36.8 compared with 46.0 yr, p 5 0.063). Patients with GMN had longer disease duration compared with patients with IN (mean, 2.2 compared with 8.0 yr, p 5 0.001). The majority of patients with GMN (80%) had mixed monoclonal cryoglobulinemia IgMk (type II) and lower complement C4 levels. Two patients (both with GMN) developed chronic renal failure requiring hemodialysis. Overall, clinically significant renal involvement is infrequent in pSS. IN occurs early in the disease process, while GMN is a late sequela and may have a less favorable prognosis.