C2. Pneumonia adquirida na comunidade (PAC) – influência da terapêutica com macrólidos ou novas fluoroquinolonas na evolução e duração de internamento

The need to cover atypical agents in the initial Community-Acquired Pneumonia (CAP) inpatients therapy is currently the focus of much debate. A lack of consensus in this issue might relate to regional variation in the prevalence of atypical agents. The most recent American guidelines (ATS and IDSA) suggest the use of a macrolid or a antipneumococcal fluoroquinolone in the initial empirical therapy of CAP, so that atypical agents are also always covered. This study aimed to compare the progression and length of hospitalization between CAP patients treated with a combination of a beta-lactamic antibiotic and a macrolid or a new quinolone (Group I) and other form of therapy without atypical agent coverage (Group II). A retrospective study was performed with 180 inpatients, admitted with PAC diagnosis between December 2000 and May 2002 in a general Pneumology Service. 105 (58,3%) patients were included in Group I and 75 (41,7%) in Group II. There were no statistically significant differences between the two groups regarding age, sex, clinical presentation, co morbidities or severity of the inaugural presentation. There were 14 patients with unfavourable clinical progression belonging 50% of them to Group I. The average of the length of hospital stay in Group I was 12.2 days and 13.7 days in Group II, which is also a non-significant statistical difference.Then, we may conclude that initial therapy covering atypical agents might not always be necessary. Prospective studies will be important to further address this question and to investigate the epidemiology of atypical agents of CAP in Portugal

Estudo radiográfico de "calaítes" portuguesas.

83 Jan.-Dez. 1973, p. 125-144

Cosmogenic gamma-rays and the composition of cosmic rays

We discuss the prospects of detecting the sources of ultra-high energy (UHE) cosmic ray (CR) nuclei via their emission of cosmogenic gamma-rays in the GeV to TeV energy range. These gamma-rays result from electromagnetic cascades initiated by high energy photons, electrons and positrons that are emitted by CRs during their propagation in the cosmic radiation background and are independent of the simultaneous emission of gamma-rays in the vicinity of the source. The corresponding production power by UHE CR nuclei (with mass number A and charge Z) is dominated by pion photo-production (~ A) and Bethe-Heitler pair production (~ Z^2). We show that the cosmogenic gamma-ray signal from a single steady UHE CR source is typically more robust with respect to variations of the source composition and injection spectrum than the accompanying signal of cosmogenic neutrinos. We study the diffuse emission from the sum of extragalactic CR sources as well as the point source emission of the closest sources.Comment: 14 pages, 5 figure

Differential associations of APOE-epsilon 2 and APOE-epsilon 4 alleles with PET-measured amyloid-beta and tau deposition in older individuals without dementia

Purpose: To examine associations between the APOE-ε2 and APOE-ε4 alleles and core Alzheimer’s disease (AD) pathological hallmarks as measured by amyloid-β (Aβ) and tau PET in older individuals without dementia. Methods: We analyzed data from 462 ADNI participants without dementia who underwent Aβ ([18F]florbetapir or [18F]florbetaben) and tau ([18F]flortaucipir) PET, structural MRI, and cognitive testing. Employing APOE-ε3 homozygotes as the reference group, associations between APOE-ε2 and APOE-ε4 carriership with global Aβ PET and regional tau PET measures (entorhinal cortex (ERC), inferior temporal cortex, and Braak-V/VI neocortical composite regions) were investigated using linear regression models. In a subset of 156 participants, we also investigated associations between APOE genotype and regional tau accumulation over time using linear mixed models. Finally, we assessed whether Aβ mediated the cross-sectional and longitudinal associations between APOE genotype and tau. Results: Compared to APOE-ε3 homozygotes, APOE-ε2 carriers had lower global Aβ burden (βstd [95% confidence interval (CI)]: − 0.31 [− 0.45, − 0.16], p = 0.034) but did not differ on regional tau burden or tau accumulation over time. APOE-ε4 participants showed higher Aβ (βstd [95%CI]: 0.64 [0.42, 0.82], p < 0.001) and tau burden (βstd range: 0.27-0.51, all p < 0.006). In mediation analyses, APOE-ε4 only retained an Aβ-independent effect on tau in the ERC. APOE-ε4 showed a trend towards increased tau accumulation over time in Braak-V/VI compared to APOE-ε3 homozygotes (βstd [95%CI]: 0.10 [− 0.02, 0.18], p = 0.11), and this association was fully mediated by baseline Aβ. Conclusion: Our data suggest that the established protective effect of the APOE-ε2 allele against developing clinical AD is primarily linked to resistance against Aβ deposition rather than tau pathology

Histidine-rich glycoprotein and idiopathic pulmonary fibrosis

Histidine-rich glycoprotein (HRG) is an enigmatic glycoprotein able to interact with a variety of ligands such as IgG, complement components, heparan sulfate, thrombospondin, fibrinogen and plasminogen. HRG is present at high concentrations in plasma and there is evidence indicating that it is able to modulate the course of biological processes such as angiogenesis, fibroblast proliferation, complement activation, coagulation and fibrinolysis. Because these processes are involved in the pathogeneses of lung fibrosis we here analyzed a possible link between HRG and idiopathic pulmonary fibrosis (IPF). We found that plasma concentrations of HRG are significantly diminished in IPF patients compared to healthy subjects. Moreover, we found a positive correlation between HRG plasma levels and forced vital capacity (FVC) values, suggesting that plasma concentration of HRG would be a useful indicator of disease activity in IPF. HRG has been described as a negative acute phase reactant able to accumulate at sites of tissue injury. Hence, we also measured the concentrations of HRG in BAL samples from IPF patients. We found that the concentrations of HRG in samples from IPF patients were significantly higher compared to controls, suggesting that the reduced concentration of HRG in plasma from IPF patients could be due, at least in part, to an enhanced uptake of this protein in the lung.Fil: Ernst, G.. Ciudad Autónoma de Buenos Aires. María Ferrer; Argentina. Hospital Británico de Buenos Aires; ArgentinaFil: Dantas, Ezequiel Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Sabatte, Juan Atilio. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; ArgentinaFil: Caro, F.. Ciudad Autónoma de Buenos Aires. María Ferrer; ArgentinaFil: Salvado, A.. Hospital Británico de Buenos Aires; ArgentinaFil: Grynblat Pipman, Luciana. Ciudad Autónoma de Buenos Aires. María Ferrer; ArgentinaFil: Geffner, Jorge Raúl. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas en Retrovirus y Sida. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas en Retrovirus y Sida; Argentin

Utilización de la ventilación no invasiva en pacientes con parálisis diafragmática. Reporte de casos.

IntroducciónLa parálisis diafragmática (PD) es una enfermedad infrecuente, generalmente secundaria a procesos sistémicos, aunque han sido descriptas formas idiopáticas.ObjetivoDescribir la utilización de la ventilación no invasiva (VNI) como una modalidad de tratamiento en PD.Material y MétodosEstudio descriptivo de una serie de casos consecutivos en un hospital general.ResultadosDescribimos 4 pacientes portadores de PD unilateral con disminución de las presiones bucales máximas y de la capacidad vital en posición supina. Tres pacientes presentaron hipercapnia, uno de los cuales requirió intubación con asistencia respiratoria.Los 4 casos fueron tratados con VNI modo S/T bilevel, permitiendo disminuir la PCO2, mejorar los síntomas y los parámetros en la poligrafía respiratoria nocturna.ConclusionesLa aplicación de la VNI en los pacientes portadores de PD ofrece beneficios clínicos y en la función respiratoria que hacen recomendable su indicación en casos seleccionados. </p

Investigating brain connectivity heritability in a twin study using diffusion imaging data

Heritability of brain anatomical connectivity has been studied with diffusion-weighted imaging (DWI) mainly by modeling each voxel's diffusion pattern as a tensor (e.g., to compute fractional anisotropy), but this method cannot accurately represent the many crossing connections present in the brain. We hypothesized that different brain networks (i.e., their component fibers) might have different heritability and we investigated brain connectivity using High Angular Resolution Diffusion Imaging (HARDI) in a cohort of twins comprising 328 subjects that included 70 pairs of monozygotic and 91 pairs of dizygotic twins. Water diffusion was modeled in each voxel with a Fiber Orientation Distribution (FOD) function to study heritability for multiple fiber orientations in each voxel. Precision was estimated in a test-retest experiment on a sub-cohort of 39 subjects. This was taken into account when computing heritability of FOD peaks using an ACE model on the monozygotic and dizygotic twins. Our results confirmed the overall heritability of the major white matter tracts but also identified differences in heritability between connectivity networks. Inter-hemispheric connections tended to be more heritable than intra-hemispheric and cortico-spinal connections. The highly heritable tracts were found to connect particular cortical regions, such as medial frontal cortices, postcentral, paracentral gyri, and the right hippocampus