Afterpotential characteristics and firing patterns in maturing rat hippocampal CA1 neurones in in vitro slices.

The postnatal evolution of depolarizing after-potentials (DAPs) and after-hyperpolarizations (AHPs) was studied in rat CA1 hippocampal neurones (5-68 days of age) using in vitro slices. Results were pooled into 4 age groups: P5-9, P10-16, P17-24 and P26-68. In P5-9 cells, DAPs were seen as passive signals, with a time constant similar to the time constant of the membrane. The evolution of the DAP was characterized by a decrease in amplitude, an increase in duration and a change in contour. In P10-16 and P17-24 cells, the DAPs often had a plateau or a hump-like shape which increased the probability of firing and the occurrence of spike doublets. The firing pattern and bursting behaviour of P10-16 CA1 neurones differed from the pattern typical of the adult. P5-9 and P10-16 cells had post-burst AHPs with a smaller amplitude and a more prolonged early phase than at late stages of development.     

Doppler echocardiography of 119 normal-functioning St Jude Medical mitral valve prostheses: a comprehensive assessment including time-velocity integral ratio and prosthesis performance index.

The purpose of this study was to provide, in a large number of patients, comprehensive Doppler echocardiographic assessment of normal St Jude Medical mitral valve prosthesis function using Doppler-derived hemodynamic variables, including the mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio and prosthesis performance index. The pressure half-time was less than 130 milliseconds in all patients, and all but one patient had either a peak early mitral diastolic velocity of 2 m/s or less or a mitral valve prosthesis-to-left ventricular outflow tract time-velocity integral ratio of less than 2.2. There was a significant (P < .001) negative correlation between the prosthesis performance index and prosthesis size. This negative correlation suggests that there is more efficient use of the in vitro geometric orifice area with smaller prostheses.     

Benign infantile seizures with mild gastroenteritis: Study of 22 patients

PurposeTo analyze the electroclinical features, aetiology and outcome in patients with normal neurological examination and psychomotor development who presented seizures during a mild gastroenteritis (MG).Patients and methodsEvaluation of the clinical charts of 22 patients who were assessed in the Neurology Department, Hospital Nacional de Pediatría Prof. Dr. JP Garrahan between 1999 and 2007.ResultsTwelve patients were boys and 10 were girls, the age of onset ranged from 5 to 26 months, and the median age was 10 months. Rotavirus antigen test in stool was positive in 9 of 18 studied patients. The seizures were brief, focal with secondary generalization in 15 patients (68.5%), apparently generalized in 5 (22.5%) and focal in two (9%). Seven of the patients (35%) had more than one seizure in 24 h. The interictal EEG was normal in all patients. Neuroradiological studies were performed in 19 patients with a normal result. No patient was put on long-term treatment with antiepileptic drugs. Four patients had subsequent mild gastroenteritis and two of them presented convulsions during the disease. After between 12 and 67 months of follow-up, all patients had normal psychomotor development and neurological examination.ConclusionsIn this study we confirmed the association of benign infantile seizures (BIS) and MG with or without rotavirus. The identification of this entity allows avoiding unnecessary complementary studies and treatment with antiepileptic drugs.     

Determinants of left ventricular systolic function recovery after an acute coronary syndrome.

INTRODUCTION: Ischemic heart disease is a major cause of heart failure in western societies. However, the factors that may influence left ventricular function (LVF) recovery after an acute coronary syndrome (ACS) are still unclear. OBJECTIVE: To identify variables that may influence LVF evolution one year after ACS. METHODS: 104 patients hospitalized with ACS between 7/1/2001 and 12/31/2002 and with systolic dysfunction--defined as an echocardiographic ejection fraction (EF) < or = 45%--were randomly allocated to a planned coronary follow-up program (FUP) or a general cardiology clinic (GC); patients from both groups were also randomly referred to a structured cardiac rehabilitation program (CRP). EF was re-assessed at one year. We compared differences between patients who recovered left ventricular function (EF > 45%; group 1) and those who did not (group 2). RESULTS: One year after discharge, 44.2% of the patients had recovered function. There were no significant differences between the groups in gender (77.7 vs. 76.5% male), age (56 vs. 59 years), hypertension, diabetes, dyslipidemia, smoking habits or family history. A previous history of cardiovascular events was more frequent in group 2 (11.1% vs. 35.3%, p = 0.03). Cardiac catheterization was performed before discharge in 88.8% and 88.2% in groups 1 and 2 respectively (p = NS); no differences were found in coronary anatomy between the two groups. Angioplasty was performed in 54.2% in group 1 and 50% in group 2 (p = NS). There were no differences in the use of angiotensin-converting enzyme inhibitors (83.3% vs. 87.5%), beta-blockers (87.5% vs. 87.5%), nitrates (37.5% vs. 33.3%), aspirin (95.8% vs. 95.8%), statins (79.1% vs. 75%) or diuretics (20.8% vs. 45.8%). There was no significant difference in LVF recovery between patients randomized to FUP or GC (38.5% vs. 54.5%). 87.5% of patients who completed the CRP had normal EF at one year compared to 32.7% of patients not referred to the program (p = 0.009). Although EF improved in both groups, this improvement was greater in patients who completed a CRP (EF 8% vs. 5%, p = 0.003). CONCLUSION: A previous cardiovascular event and completion of a CRP were the only variables that influenced LVF recovery. Thus, enrollment in a CRP, in addition to standard therapy, could be an important therapeutic measure in patients with systolic dysfunction after ACS; our data suggest that these programs should be more widely used.     

Apoptosis and asthma in the elderly.

BACKGROUND: Asthma is a chronic inflammatory disorder of the airways. The persistence of airway inflammation depends on a decrease in apoptosis of T lymphocytes and eosinophils and survival of these activated cells. T lymphocytes expressing gamma delta receptors can be identified in human lungs and play an important role in immune defence against pathogens and in the regulation of chronic inflammation. Aging is associated with evidence of some immune dysregulation. OBJECTIVE: The aim of this study was to analyze the apoptosis receptors of T lymphocytes in long-lasting asthma, to establish their correlation with activation markers such as CD25+ and human leukocyte antigen (HLA)-DR+, and to analyze the gama delta T cell expression in this disease. METHODS: A group of 64 individuals (group A) who had had asthma for more than 30 years (mean age [+/-SD] 72 +/- 5 years) and 61 healthy individuals acting as controls--group B with 41 individuals (mean age 79 +/- 7 years) and group C with 20 individuals (mean age 38 +/- 12 years) were included in the study. All subjects underwent clinical evaluation and spirometric testing. Peripheral blood cells were stained with monoclonal antibodies anti-CD3, anti-CD4, anti-CD8, anti-CD25, anti-TCR gamma delta, anti-HLA-DR and anti-CD95. Statistical comparisons were performed between the asthmatics and the elderly control group and between the elderly control group and the adult control group. RESULTS: The average percentage of predicted forced expiratory volume in the first second was 73.6 gamma delta 25.3. The mean values of T cell receptors for asthma group A vs elderly control group B vs adult control group C respectively, were the following: CD3, 74.9+/-7 vs. 74.8 +/- 8.8 (P=ns) vs. 76.7 +/- 4.2 (P=ns); CD4, 48.8 +/- 8.7 vs. 43.5 +/- 10.2 (P=ns) vs. 44.8 +/- 3.8 (P=ns); CD8, 23.3 +/- 7.9 vs. 25.7 +/- 10.2 (P=ns) vs. 25.6 +/- 4.5 (P=ns); CD25, 14.3 +/- 5.9 vs. 22.4 +/- 7.8 (P = .0001) vs. 5.5 +/- 2.4 (P = .0001); TCR gamma delta, 2.8 +/- 2.1 vs. 4.1 +/- 3.3 (P < .05) vs. 4.6 +/- 2.1 (P=ns); HLA-DR, 18.4 +/- 9.2 vs. 17.8 +/- 5.9 (P=ns) vs. 15.4 +/- 5.1 (P=ns) and CD95, 49.3 +/- 13.7 vs. 52.6 +/- 12.1 (P=ns) vs. 13.8 +/- 10.8 (P = .0001). CONCLUSIONS: The immunological and inflammatory changes related to ageing may cause an increase in CD95 and CD25 T cell expression. In asthma, blood cells may express increased activation and apoptosis markers but in elderly patients taking steroids, these receptors remain within normal ranges. The number of gamma delta T cells may be lower in long-lasting asthma, and have a limited modulatory effect on allergic inflammatory reactions. The evaluation of patients with long-lasting asthma should take into account the immunological and inflammatory changes present in the elderly in order to avoid results being misinterpreted.     

Validation of the Brazilian-Portuguese Version of the European Community Respiratory Health Survey in Asthma Patients

Background. The European Community Respiratory Health Survey (ECRHS) questionnaire was planned to answer questions about the distribution of asthma. Our objective was to determine the cultural equivalence of the ECRHS into the Brazilian-Portuguese language. Methods. We translated the ECRHS according to international criteria. Results. Small cultural adaptations were necessary. Among the 80 participating patients, the Cronbach indices were higher (0.98-1.00) and the Kappa indices varied from 0.77 to 1.00. Conclusion. The study suggests that the Brazilian version of the ECRHS is conceptually equivalent to the original and similarly reliable and may be used in international studies involving Portuguese-speaking respiratory patients.     

Priming with a very low dose of DNA complexed with cationic block copolymers followed by protein boost elicits broad and long-lasting antigen-specific humoral and cellular responses in mice

Cationic block copolymers spontaneously assemble via electrostatic interactions with DNA molecules in aqueous solution giving rise to micellar structures that protect the DNA from enzymatic degradation both in vitro and in vivo. In addition, we have previously shown that they are safe, not immunogenic and greatly increased antigen-specific CTL responses following six intramuscular inoculations of a very low dose (1 μg) of the vaccine DNA as compared to naked DNA. Nevertheless, they failed to elicit detectable humoral responses against the antigen. To gain further insight in the potential application of this technology, here we show that a shorter immunization protocol based on two DNA intramuscular inoculations of 1 μg of DNA delivered by these copolymers and a protein boost elicits in mice broad (both humoral and cellular) and long-lasting responses and increases the antigen-specific Th1-type T cell responses and CTLs as compared to priming with naked DNA. These results indicate that cationic block copolymers represent a promising adjuvant and delivery technology for DNA vaccination strategies aimed at combating intracellular pathogens.