Demonstration of antibody and cellular immune response to brain extract in West and Lennox-Gastaut syndromes

We investigated humoral and cellular immune response to brain tissues in 15 patients with West syndrome, in 9 patients with Lennox-Gastaut syndrome and in 20 healthy children. High levels of a precipitating antibody to a saline extract of brain tissue were detected in all patients; leucocyte migration inhibition test with the same antigen was found to be positive in most of them. The role of this autoimmune response in the pathogenesis of West and Lennox-Gastaut syndromes remains to the elucidated.     

Predictive factors of outcome following staphylococcal peritonitis in continuous ambulatory peritoneal dialysis

BACKGROUND AND AIMS: Staphylococcus epidermidis and other coagulase-negative staphylococci (CoNS) are the most common agents of continuous ambulatory peritoneal dialysis (CAPD) peritonitis. Episodes caused by Staphylococcus aureus evolve with a high method failure rate while CoNS peritonitis is generally benign. The purpose of this study was to compare episodes of peritonitis caused by CoNS species and S. aureus to evaluate the microbiological and host factors that affect outcome. MATERIAL AND METHODS: Microbiological and clinical data were retrospectively studied from 86 new episodes of peritonitis caused by staphylococci species between January 1996 and December 2000 in a university dialysis center. The influence of microbiological and host factors (age, sex, diabetes, use of vancomycin, exchange system and treatment time on CAPD) was analyzed by logistic regression model. The clinical outcome was classified into two results (resolution and non-resolution). RESULTS: The odds of peritonitis resolution were not influenced by host factors. Oxacillin susceptibility was present in 30 of 35 S. aureus lineages and 22 of 51 CoNS (p = 0.001). There were 32 of 52 (61.5%) episodes caused by oxacillin-susceptible and 20 of 34 (58.8%) by oxacillin-resistant lineages resolved (p = 0.9713). Of the 35 cases caused by S. aureus, 17 (48.6%) resolved and among 51 CoNS episodes 40 (78.4%) resolved. Resolution odds were 7.1 times higher for S. epidermidis than S. aureus (p = 0.0278), while other CoNS had 7.6 times higher odds resolution than S. epidermidis cases (p = 0.052). Episodes caused by S. haemolyticus had similar resolution odds to S. epidermidis (p = 0.859). CONCLUSIONS: S. aureus etiology is an independent factor associated with peritonitis non-resolution in CAPD, while S. epidermidis and S. haemolyticus have a lower resolution rate than other CoNS. Possibly the aggressive nature of these agents, particularly S. aureus, can be explained by their recognized pathogenic factors, more than antibiotic resistance.     

Expression and localization of aromatase P450AROM, estrogen receptor-α, and estrogen receptor-β in the developing fetal bovine frontal cortex

The enzyme aromatase (P450_AROM) converts testosterone (T) into 17-β estradiol (E₂) and is crucial for the control of development of the central nervous system during ontogenesis. The effects of E₂ in various brain areas are mediated by the estrogen receptor alpha (ER-α) and the estrogen receptor beta (ER-β). During fetal development, steroids are responsible for the sexual differentiation of the hypothalamus. Estrogens are also able to exert effects in other brain areas of the fetus including the frontal cortex, where they act through estrogen receptors (ERs) modulating cognitive function and affective behaviors.In this study we have determined the expression profiles of P450_AROM and ERs in the fetal bovine frontal cortex by quantitative Real-Time PCR (qRT-PCR) throughout the prenatal development. The data show that the patterns of expression of both ERs are strongly correlated during pregnancy and increase in the last stage of gestation. On the contrary, the expression of P450_AROM has no correlation with ERs expression and is not developmentally regulated.Moreover, we performed immunochemical studies showing that fetal neurons express P450_AROM and the ERs. P450_AROM is localized in the cytoplasm and only seldom present in the fine extensions of the cells; ER-α is detected predominantly in the soma whereas ER-β is only present in the nucleus of a few cells. This study provides new data on the development of the frontal cortex in a long gestation mammal with a large convoluted brain.     

Detection of SPM and IMP metallo-β-lactamases in clinical specimens of Pseudomonas aeruginosa from a Brazilian public tertiary hospital

Phenotypic and genotypic SPM and IMP metallo-β-lactamases (MBL) detection and also the determination of minimal inhibitory concentrations (MIC) to imipenem, meropenem and ceftazidime were evaluated in 47 multidrug-resistant Pseudomonas aeruginosa isolates from clinical specimens. Polymerase chain reaction detected 14 positive samples to either bla_SPM or bla_IMP genes, while the best phenotypic assay (ceftazidime substrate and mercaptopropionic acid inhibitor) detected 13 of these samples. Imipenem, meropenem and ceftazidime MICs were higher for MBL positive compared to MBL negative isolates. We describe here the SPM and IMP MBL findings in clinical specimens of P. aeruginosa from the University Hospital of Botucatu Medical School, São Paulo, Brazil, that reinforce local studies showing the high spreading of bla_SPM and bla_IMP genes among Brazilian clinical isolates.     

The role of virulence factors in the outcome of staphylococcal peritonitis in CAPD patients

Background  

Peritonitis continues to be the most frequent cause of peritoneal dialysis (PD) failure, with an important impact on patient mortality. Gram-positive cocci such as Staphylococcus epidermidis, other coagulase-negative staphylococci (CoNS), and Staphylococcus aureus are the most frequent etiological agents of PD-associated peritonitis worldwide. The objective of the present study was to compare peritonitis caused by S. aureus and CoNS and to evaluate the factors influencing outcome.     

ANTHELMINTIC ACTIVITY OF LAPACHOL, β-LAPACHONE AND ITS DERIVATIVES AGAINST Toxocara canis LARVAE

Anthelmintics used for intestinal helminthiasis treatment are generally effective;however, their effectiveness in tissue parasitosis (i.e. visceral toxocariasis) ismoderate. The aim of this study was to evaluate the in vitroactivityof lapachol, β-lapachone and phenazines in relation to the viability ofToxocara canis larvae. A concentration of 2 mg/mL (in duplicate)of the compounds was tested using microculture plates containing Toxocaracanis larvae in an RPMI-1640 environment, incubated at 37 °C in 5%CO₂ tension for 48 hours. In the 2 mg/mL concentration, fourphenazines, lapachol and three of its derivatives presented a larvicide/larvistaticactivity of 100%. Then, the minimum larvicide/larvistatic concentration (MLC) testwas conducted. The compounds that presented the best results were nor-lapachol (MLC,1 mg/mL), lapachol (MLC 0.5 mg/mL), β-lapachone, and β-C-allyl-lawsone (MLC, 0.25mg/mL). The larvae exposed to the compounds, at best MLC with 100% invitro activity larvicide, were inoculated into healthy BALB/c mice andwere not capable of causing infection, confirming the larvicide potential invitro of these compounds.     

Beneficial effects of oral tilactase on patients with hypolactasia

Background A lactose‐free diet is commonly prescribed to subjects with hypolactasia. We tested the effectiveness of a single ingestion of tilactase (a β‐d ‐galactosidase from Aspergillus oryzae) in adults with hypolactasia, previously assessed by lactose H₂‐breath test. Materials and methods After measurement of orocecal transit time (OCTT, by lactulose H₂‐breath test) and lactose H₂‐breath testing plus placebo, a total of 134 subjects were positive to hypolactasia and underwent lactose H₂‐breath testing plus either low (6750 U) or standard (11 250 U) doses of tilactase. The appearance of gastrointestinal symptoms during the tests was monitored. Results OCTT was longer in malabsorbers (subjects without bloating, abdominal pain and/or diarrhoea, n = 25) than in intolerants (bloating, abdominal pain and/or diarrhoea, n = 109, P < 0·02). Malabsorbers had longer time to H₂ peak (P < 0·03), lower H₂ peak levels (P < 0·002) and smaller integrated H₂ excretion levels (P < 0·005) than intolerants. After tilactase ingestion, integrated H₂ levels were decreased by 75% (low dose) and 87% (standard dose) in malabsorbers, and by 74% (low dose) and 88% (standard dose) in intolerants. In the latter group, total symptom score were decreased by 76% (low dose) and by 88% (standard dose) (P < 0·0001). Conclusion A single oral administration of tilactase is highly effective in decreasing symptoms and hydrogen excretion of hypolactasia assessed by lactose H₂‐breath test. If confirmed by long‐term observations, ingestion of tilactase might be a better option than exclusion diets in intolerant subjects with hypolactasia.     

Immunological disturbance in West and Lennox-Gastaut syndromes

Cell-mediated and humoral immunity were investigated in 18 patients with West syndrome, 12 with Lennox-Gastaut syndrome and 19 healthy controls. The study included determination of T and B peripheral blood lymphocytes, serum levels of IgG, IgA and IgM, skin sensibilization with DNCB, intracutaneous PHA, leucocyte migration inhibition test and lymphocyte blastic transformation in the presence of PHA. Cell-mediated deficiency was detected in 28 children whereas low levels of immunoglobulins were observed only in 6 children. Immunological disturbances were more prominent in children with West syndrome.     

Peritoneal Dialysis–Related Peritonitis due to Coagulase-Negative Staphylococcus: A Review of 115 Cases in a Brazilian Center

Background and objectives

Coagulase-negative Staphylococcus (CNS) is the most frequent cause of peritoneal dialysis (PD)–related peritonitis in many centers. This study aimed to describe clinical and microbiologic characteristics of 115 CNS episodes and to determine factors influencing the outcome.

Design, setting, participants, & measurements

This study reviewed the records of 115 CNS peritonitis episodes that occurred in 74 patients between 1994 and 2011 at a single university center. Peritonitis incidences were calculated for three consecutive 6-year periods (P1, 1994–1999; P2, 2000–2005; P3, 2006–2011) and annually. The production of biofilms, enzymes, and toxins was evaluated. Oxacillin resistance was evaluated based on its minimum inhibitory concentration and the presence of the mecA gene.

Results

The overall incidence of CNS peritonitis was 0.15 episodes per patient per year and did not vary over time (0.12, 0.14, and 0.16 for P1, P2, and P3, respectively; P=0.21). The oxacillin resistance rate was 69.6%. Toxin and enzyme production was infrequent and 36.5% of CNS strains presented the gene encoding biofilm production. The presence of icaAD genes associated with biofilm production was predictive of relapses or repeat episodes (odds ratio [OR], 2.82; 95% confidence interval [95% CI], 1.11 to 7.19; P=0.03). Overall, 70 episodes (60.9%) resolved; oxacillin susceptibility (OR, 4.41; 95% CI, 1.48 to 13.17; P=0.01) and vancomycin use as the first treatment (OR, 22.27; 95% CI, 6.16 to 80.53; P<0.001) were the only independent predictors of resolution.

Conclusions

Oxacillin resistance and vancomycin use as the first treatment strongly influence the resolution rate in CNS peritonitis, which reinforces the validity of the International Society for Peritoneal Dialysis guidelines on monitoring bacterial resistance to define protocols for initial treatment. These results also suggest that the presence of biofilm is a potential cause of repeat peritonitis episodes.