Interleukin-1beta polymorphisms in Colombian patients with autoimmune rheumatic diseases

Interleukin-1 beta (IL-1beta) exerts a range of inflammatory and immunomodulatory activities that are important in host defense and autoimmune response. The IL-1beta gene, located on chromosome 2 (2q13), is polymorphic. The influence of its polymorphism on 355 patients with autoimmune rheumatic diseases was examined. To this effect, 172 patients with rheumatoid arthritis (RA), 114 with systemic lupus erythematosus (SLE), and 69 with primary Sjogren's syndrome (pSS) were studied. The control group consisted of 392 matched healthy individuals. Genotyping of IL-1beta single-nucleotide polymorphisms (SNPs) at positions -511 (C/T) and + 3953 (C/T) was performed by the polymerase chain reaction-restriction fragment length polymorphism technique. In addition, levels of IL-1beta were measured by immunoassay in supernatants of lipopolysaccharide (LPS)-stimulated and nonstimulated peripheral blood monocytes (PBM) obtained from 19 homozygous individuals for the three most common IL-1beta likely haplotypes, all belonging to the control group. Allele + 3953T was protective for SLE (odds ratio (OR) = 0.57, 95% confidence intervals (CI) = 0.34-0.88, P = 0.01) as was the haplotype -511C + 3953T (OR = 0.43, 95%CI = 0.25-0.74, pc = 0.006). The latter was associated with a lower LPS-stimulated-PBM IL-1beta secretion. Results suggest that IL-1beta polymorphism influences the susceptibility to acquire SLE in our population. The protective association might be explained by the observed inhibitory effect of IL-1beta + 3953T allele on the secretion of IL-1beta under inflammatory circumstances.     

New microsatellite multiplex PCR for Candida albicans strain typing reveals microevolutionary changes

Five new microsatellite loci were described and characterized for use as molecular markers for the identification and genetic differentiation of Candida albicans strains. Following the typing of 72 unrelated clinical isolates, the analysis revealed that they were all polymorphic, presenting from 5 to 30 alleles and 8 to 46 different genotypes. The discriminatory power obtained by combining the information generated by three microsatellites used in a multiplex PCR amplification strategy was 0.99, the highest ever reported. The multiplex PCR was later used to test a total of 114 C. albicans strains, including multiple isolates from the same patient collected from different body locations and along episodes of vulvovaginal infections. Three different scenarios for strain relatedness were identified: (i) different isolates that were revealed to be the same strain, (ii) isolates that were the same strain but that apparently underwent a process of microevolution, and (iii) isolates that corresponded to different strains. Analysis of the microevolutionary changes between isolates from recurrent infections indicated that the genotype alterations observed could be the result of events that lead to the loss of heterozygosity (LOH). In one case of recurrent infection, LOH was observed at the CAI locus, and this could have been related to exposure to fluconazole, since such strains were exposed to this antifungal during treatment. The analysis of microsatellites by a multiplex PCR strategy was found to be a highly efficient tool for the rapid and accurate differentiation of C. albicans strains and adequate for the identification of fine microevolutionary events that could be related to strain microevolution in response to environmental stress conditions.     

Leptospiral antigens in the liver of experimentally infected guinea pig and their relation to the morphogenesis of liver damage.

In order to investigate the morphogenes of experimental leptospirosis by morphologic and immunohistologic methods, 24 guinea-pigs were inoculated intraperitoneally with L. interrogans serogroup Icterohaemorrhagiae. They were divided in 6 groups, sacrificed from the 1st to the 6th day of infection. Semiquantitative analyses of histopathological liver lesions were performed in 1 micron sections of tissue embedded in glycol-methacrylate. The distribution of leptospiral antigen (L. Ag) and its glycolipoprotein (GLP) was demonstrated by peroxidase-antiperoxidase on paraffin embedded tissue. Significant lesions appeared at the 4th day of infection, progressing to a peak on the 6th day. Inflammation was associated with injury of the portal triad. Liver cells showed either swelling or acidophilic degeneration and necrosis, together with loss of cell cohesion, leading to disarray of liver cell plates. Mitochondria were found progressively enlarged and irregularly distributed. L. Ag expression was parallel to the morphological changes. Portal distribution was significant at the 4th day and on later stages centrilobular localization became predominant. Spiral forms suggestive of intact leptospires were initially found but, chiefly at the 6th day, L. Ag was seen in granules, probably resulting from phagocytosis. GLP staining was similar to granular L. Ag in morphology, and distribution. Cytokeratin condensation was seen in liver cells with acidophilic necrosis and was marked in areas of disorganization of cell plates. Our findings lead us to hypothesize a direct leptospiral cytotoxic effect on endothelial and on liver-cell membranes. At first, leptospires themselves would induce subcellular changes acting mainly on membrane permeability. Afterwards, their granular forms, including GLP, would act as adjuvant factors. These findings demonstrate that the disarray of liver cell plates at the late phase of the disease is genuine.     

Trends in drug resistance, serotypes, and molecular types of Streptococcus pneumoniae colonizing preschool-age children attending day care centers in Lisbon, Portugal: a summary of 4 years of annual surveillance

Of the nasopharyngeal cultures recovered from 942 day care center (DCC) attendees in Lisbon, Portugal, 591 (62%) yielded Streptococcus pneumoniae during a surveillance performed in February and March of 1999. Forty percent of the isolates were resistant to one or more antimicrobial agents. In particular, 2% were penicillin resistant and 20% had intermediate penicillin resistance. Multidrug resistance to macrolides, lincosamides, and tetracycline was the most frequent antibiotype (17% of all isolates). Serotyping and molecular typing by pulsed-field gel electrophoresis were performed for 202 out of 237 drug-resistant pneumococci (DRPn). The most frequent serotypes were 6B (26%), 14 (22%), 19F (16%), 23F (10%), and nontypeable (12%). The majority (67%) of the DRPn strains were representatives of nine international clones included in the Pneumococcal Molecular Epidemiology Network; eight of them had been detected in previous studies. Fourteen novel clones were identified, corresponding to 26% of the DRPn strains. The remaining 7% of the strains were local clones detected in our previous studies. Comparison with studies conducted since 1996 in Portuguese DCCs identified several trends: (i) the rate of DRPn frequency has fluctuated between 40 and 50%; (ii) the serotypes most frequently recovered have remained the same; (iii) nontypeable strains appear to be increasing in frequency; and (iv) a clone of serotype 33F emerged in 1999. Together, our observations highlight that the nasopharynxes of children in DCCs are a melting pot of successful DRPn clones that are important to study and monitor if we aim to gain a better understanding on the epidemiology of this pathogen.     

Ultrastructure of the gastric mucosa harboring Campylobacter-like organisms

The association between Campylobacter-like organisms (CLOs) and lesions of the gastric mucosa was studied in 59 consecutive biopsies. Hematoxylin and eosin and Warthin-Starry silver stains, as well as high-resolution light microscopy (HRLM) and transmission electron microscopy (TEM), were used. The organisms were found in intimate contact with foveolar cells showing abundant phagolysosomes and alterations of the intercellular complexes. CLOs also were seen in close proximity of parietal cells in resting phase, some of which showed degenerative changes. The findings are discussed in light of recent reports linking CLOs to the cause of gastritis.     

Prevalence and risk factors for Chlamydia trachomatis infection in adolescent females and young women in central Brazil

In order to determine the prevalence and risk factors for Chlamydia trachomatis infection in adolescent females and young women in central Brazil, 296 subjects attending two public health services were evaluated. The overall prevalence of C. trachomatis infection, as determined using polymerase chain reaction, was 19.6% (95% confidence interval [CI], 15.3–24.7). In multivariate analysis, young age (odds ratio [OR]_adjusted 2.32, 95%CI 1.1–4.8, p<0.05) and having 2–3 (OR_adjusted 3.41, 95%CI 1.6–6.3, p<0.05) or ≥4 sexual partners in life (OR_adjusted 3.10, 95%CI 1.1–6.3, p<0.05) were factors significantly associated with chlamydial infection. In conclusion, the prevalence of C. trachomatis infection was high in the studied population and risk factors were related to age and sexual behavior.     

DNA damage in cytologically normal urothelial cells of patients with a history of urothelial cell carcinoma

In order to determine if patients with a history of previous urothelial cell carcinoma (UCC) but with current normal urinary cytology have DNA damage in urothelial cells, the single-cell gel electrophoresis (comet) assay was conducted with cells obtained by urinary bladder washings from 44 patients (28 with a history of previous UCC). Increased DNA damage was observed in cytologically "normal" urothelial cells of patients with a history of UCC when compared with referents with no similar history and after correcting the data for smoking status and age (P < 0.018). Increased DNA damage also correlated with the highest tumor grade, irrespective of time or course of the disease after clinical intervention (Kendall tau correlation, 0.37, P = 0.016). Moreover, aneuploidy, as assessed by DNA content ratio (DCR; 75th/25th percentile of total DNA fluorescence of 50 comets/patient) was unaltered by smoking status, but increased with UCC grade: 1.39 +/- 0.12 (median +/- 95% confidence interval; referents); 1.43 +/- 0.11 (Grade I UCC; P = 0.264, against referents); 1.49 +/- 0.16 (Grade II UCC; P = 0.057); 1.57 +/- 0.16 (Grade III UCC; P = 0.003). Micronucleated urothelial cells (MNC) were also scored on Giemsa-stained routine cytological smears and were found not to correlate with DNA damage or DCR. MNC frequencies were higher for patients with a history of UCC and/or smoking than referents with neither history, but there was no statistical difference between groups. Taken together, these results suggest that the normal-appearing urothelium of patients resected for UCC still harbor genetically unstable cells.     

Brain catalase activity is highly correlated with ethanol-induced locomotor activity in mice

It has been demonstrated that acute administration of lead to mice enhances brain catalase activity and ethanol-induced locomotion. These effects of lead seem to be related, since they show similar time courses and occur at similar doses. In the present study, in an attempt to further evaluate the relation between brain catalase activity and lead-induced changes in ethanol-stimulated locomotion, the interaction between lead acetate and 3-amino-1H,2,4-triazole (AT), a well-known catalase inhibitor, was assessed. In this study, lead acetate or saline was acutely injected intraperitoneally to Swiss mice at doses of 50 or 100 mg/kg 7 days before testing. On the test day, animals received an intraperitoneal injection of AT (0, 10, or 500 mg/kg). Five hours following AT treatment, ethanol (0.0 or 2.5 g/kg, ip) was injected and the animals were placed in open-field chambers, in which locomotion was measured for 10 min. Neither lead exposure nor AT administration, either alone or in combination, had any effect on spontaneous locomotor activity. AT treatment reduced ethanol-induced locomotion as well as brain catalase activity. On the other hand, ambulation and brain catalase activity were significantly increased by both doses of lead. Furthermore, AT significantly reduced the potentiation produced by lead acetate on brain catalase and on ethanol-induced locomotor activity in a dose-dependent manner. A significant correlation was found between locomotion and catalase activity across all test conditions. The results show that brain catalase activity is involved in the effects of lead acetate on ethanol-induced locomotion in mice. Thus, this study confirms the notion that brain catalase provides the molecular basis for understanding some of the mechanisms of the action of ethanol in the central nervous system.