Efficacy of vigabatrin intervention in a mild phenotypic expression of succinic semialdehyde dehydrogenase deficiency

We report a patient with succinic semialdehyde dehydrogenase deficiency who presented a mild phenotype including developmental language delay, in association with the typical elevations of 4-hydroxybutyric acid (GHB) in biological fluids and MRI alterations. Two pathogenic mutations were identified one transversion (c.278 G>T) in exon 1 and another (c.1557 T>G) in exon 10. Both parents are carriers of one of the mutations, confirming compound-heterozygosity in their affected child. To reduce the GHB levels in body fluids, a treatment with vigabatrin at low dose (25 mg/kg per day) was started, monitoring its efficacy by clinical and neurochemical follow-up. After 9 months of therapy with vigabatrin, a significant reduction of GHB concentrations in urine and CSF was observed; after 36 months, a significant improvement of communicative skills, not previously reported, was referred. These results support the hypothesis that the clinical improvement is correlated to the reduction in the GHB levels and the importance of considering the SSADH deficiency in the differential diagnosis of patients with mental retardation and language delay.

Vaccination with Trypanosoma rangeli modulates the profiles of immunoglobulins and IL-6 at local and systemic levels in the early phase of Trypanosoma cruzi experimental infection

In America, there are two species of Trypanosoma that can infect humans: Trypanosoma cruzi, which is responsible for Chagas disease and Trypanosoma rangeli, which is not pathogenic. We have developed a model of vaccination in mice with T. rangeli epimastigotes that protects against T. cruzi infection. The goal of this work was to study the pattern of specific immunoglobulins in the peritoneum (the site of infection) and in the sera of mice immunized with T. rangeli before and after challenge with T. cruzi. Additionally, we studied the effects triggered by antigen-antibodies binding and the levels of key cytokines involved in the humoral response, such as IL-4, IL-5 and IL-6. The immunization triggered the production of antibodies reactive with T. cruzi in peritoneal fluid (PF) and in serum, mainly IgG1 and, to a lesser magnitude, IgG2. Only immunized mice developed specific IgG3 antibodies in their peritoneal cavities. Antibodies were able to bind to the surface of the parasites and agglutinate them. Among the cytokines studied, IL-6 was elevated in PF during early infection, with higher levels in non-immunized-infected mice. The results indicate that T. rangeli vaccination against T. cruzi infection triggers a high production of specific IgG isotypes in PF and sera before infection and modulates the levels of IL-6 in PF in the early periods of infection.

Chagas disease: serological and electrocardiographic studies in Wichi and Creole communities of Misión Nueva Pompeya, Chaco, Argentina

Chagas disease, which is caused by Trypanosoma cruzi, affects nearly 16 million people in Latin America and causes 75-90 million people to be at risk of infection. The disease is urbanizing and globalizing due to frequent migrations. There are regions of high prevalence of infection, including the north-eastern provinces of Argentina and the entire phytogeographic region known as the Gran Chaco. In the province of Chaco, Argentina, there are places inhabited by native populations such as the Wichi and Toba communities, among others. Many Creole populations resulting from miscegenation with European colonists and immigrants coexist within these communities. It has been widely accepted that in the chronic phase of the disease, between 25-30% of individuals develop some form of cardiac disease, with the right bundle-branch block being the most typical condition described so far. The aim of this work was to study the prevalence of Chagas infection and its electrocardiographic profile in the Wichi and Creole populations of Misión Nueva Pompeya, in the area known as Monte Impenetrable in Chaco, to determine the prevalence and the pattern of heart diseases produced by Chagas disease in this region.

Terrestrial gamma-ray flashes as powerful particle accelerators

Strong electric discharges associated with thunderstorms can produce terrestrial gamma-ray flashes (TGFs), i.e., intense bursts of x rays and γ rays lasting a few milliseconds or less. We present in this Letter new TGF timing and spectral data based on the observations of the Italian Space Agency AGILE satellite. We determine that the TGF emission above 10 MeV has a significant power-law spectral component reaching energies up to 100 MeV. These results challenge TGF theoretical models based on runaway electron acceleration. The TGF discharge electric field accelerates particles over the large distances for which maximal voltages of hundreds of megavolts can be established. The combination of huge potentials and large electric fields in TGFs can efficiently accelerate particles in large numbers, and we reconsider here the photon spectrum and the neutron production by photonuclear reactions in the atmosphere.

Effect of trans-resveratrol on induced oxidative stress in human sperm and in rat germinal cells

Resveratrol is a phytoalexin with antioxidant properties. We evaluated resveratrol toxicity in swim-up selected human sperm and in rat spermatocytes and spermatids separated by the STAPUT method. Resveratrol antioxidant activity was tested against lipid peroxidation (LPO) induced by tert-butyl hydroperoxide. LPO was evaluated using the C11-BODIPY(581/591) probe and transmission electron microscopy in samples incubated with and without resveratrol. LD50 for human sperm and rat spermatids was 50 μM; spermatocytes were more sensitive to resveratrol cytotoxicity. Sperm motility increased progressively at 30 μM, 15 μM and 6 μM. 15 μM resveratrol acts against LPO, preserving sperm chromatin and plasma membranes. LPO were more marked in spermatocytes than in spermatids and the effect of resveratrol was more evident in spermatocytes. In this study, the scavenger properties of resveratrol were demonstrated in vitro in human sperm and rat germ cells, thus resveratrol could be added to the media used in assisted reproduction techniques and cryopreservation when oxidative stress is exacerbated.

Gamma-ray localization of terrestrial gamma-ray flashes

Terrestrial gamma-ray flashes (TGFs) are very short bursts of high-energy photons and electrons originating in Earth's atmosphere. We present here a localization study of TGFs carried out at gamma-ray energies above 20 MeV based on an innovative event selection method. We use the AGILE satellite Silicon Tracker data that for the first time have been correlated with TGFs detected by the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of ∼5-10° at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible with a terrestrial production site closer to the subsatellite point than 400 km. Considering that our gamma rays reach the AGILE satellite at 540 km altitude with limited scattering or attenuation, our measurements provide the first precise direct localization of TGFs from space.

American tripanosomiasis: a study on the prevalence of Trypanosoma cruzi and Trypanosoma cruzi-like organisms in wild rodents in San Luis province, Argentina

INTRODUCTION: Chagas disease is caused by Trypanosoma cruzi. Wild and perianthropic mammals maintain the infection/transmission cycle, both in their natural habitat and in the peridomestic area. The aim of this paper was to present the results from a study on wild rodents in the central and northern regions of San Luis province, Argentina, in order to evaluate the prevalence of this infection. METHODS: Sherman traps were set up in capture areas located between latitudes 32º and 33º S, and longitudes 65º and 66º W. The captured rodents were taxonomically identified and hemoflagellates were isolated. Morphological, biometric and molecular studies and in vitro cultures were performed. Infection of laboratory animals and histological examination of the cardiac muscle and inoculation area were also carried out. Parasites were detected in circulating blood in Calomys musculinus, Graomys griseoflavus, Phyllotis darwini and Akodon molinae. The parasites were identified using biological criteria. Molecular PCR studies were performed on some isolates, which confirmed the characterization of these hemoflagellates as Trypanosoma cruzi. RESULTS AND CONCLUSIONS: Forty-four percent of the 25 isolates were identified as Trypanosoma cruzi, and the remaining 56% as Trypanosoma cruzi-like. These findings provide evidence that wild rats infected with Trypanosoma cruzi and Trypanosoma cruzi-like organisms are important in areas of low endemicity.

Seroprevalence of Trypanosoma cruzi infection and vector control activities in rural communities of the southern Gran Chaco (Argentina)

We compared age-related seroprevalence of Trypanosoma cruzi infection with history of vector control interventions and social and ecological changes in three historically endemic departments of Cordoba province, Argentina, covering an area of 42,600 km(2) of the Gran Chaco region. Using a cross sectional design, blood samples of 5240 people between 6 months and 40 years of age, living in 192 rural communities were analyzed to detect T. cruzi infection using ELISA tests, and confirmed with indirect immunofluorescent antibody test and indirect haemoagglutination. Overall seroprevalence was 5.4%, 7.9% and 7.5% in the north, northwest and west studied areas (average for all areas 6.95%). Seroprevalence for T cruzi increased with population age, especially in age classes older than 15 years of age. Communities of the north and west areas showed 0.59% seroprevalence for T. cruzi in children below 15 years of age, whereas children of the same age in the northwest region showed a seroprevalence of 3.08%. Comparative analyses indicate that vector control activities and land use changes during the last decades are the most likely causes of the overall reduction of T. cruzi prevalence. Results suggest that the vectorial transmission of T. cruzi has been strongly reduced and probably interrupted in the north and west areas, but it is still active in the northwestern rural settlements of Córdoba province.

Measurement of the cosmic ray e+ +e- spectrum from 20 GeV to 1 TeV with the Fermi Large Area Telescope

Designed as a high-sensitivity gamma-ray observatory, the Fermi Large Area Telescope is also an electron detector with a large acceptance exceeding 2 m;{2} sr at 300 GeV. Building on the gamma-ray analysis, we have developed an efficient electron detection strategy which provides sufficient background rejection for measurement of the steeply falling electron spectrum up to 1 TeV. Our high precision data show that the electron spectrum falls with energy as E-3.0 and does not exhibit prominent spectral features. Interpretations in terms of a conventional diffusive model as well as a potential local extra component are briefly discussed.

Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study, we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired; however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV- and HBV-infected patients versus controls.

X-ray powder diffraction quantitative analysis of an amorphous SiO2–poly(methyl methacrylate) nanocomposite

Quantification of individual phases within a multiphase amorphous material has been achieved using a newly developed technique based on X-ray powder diffraction. The quantification method was developed during a study of an amorphous silica–poly(methyl methacrylate) (SiO2–PMMA) hybrid nanocomposite. The efficiency of the method as a quantifying tool for individual phases was demonstrated for samples of SiO2–PMMA prepared either by polymerization of methyl methacrylate in the presence of amorphous SiO2or by mechanically mixing known quantities of the individual and pre-prepared SiO2and PMMA materials. The weight percentages of amorphous SiO2in the nanocomposites as determined by application of the new technique were analogously found to be 29%, a result that was supported by thermogravimetric analysis and helium picnometry measurements.

Sperm ultrastructure and meiotic segregation in a group of patients with chronic hepatitis B and C

Little is known about the effect of chronic hepatitis B and hepatitis C on sperm quality. In this study we analysed sperm quality from selected patients with chronic hepatitis B virus (HBV) or hepatitis C virus (HCV) infections. Semen samples were examined by light and transmission electron microscopy (TEM). TEM data were elaborated with a mathematical formula able to indicate a fertility index and the presence of the three main sperm pathologies: apoptosis, immaturity and necrosis. Meiotic chromosome segregation was investigated by fluorescence in situ hybridisation carried out on sperm nuclei, using probes for chromosomes 18, X and Y. Despite normal sperm concentration, we observed reduced motility. TEM analysis highlighted that 35.7% of patients showed generally good semen quality. However, significantly higher values of apoptosis and necrosis, compared with controls, were observed, demonstrating spermatogenetic alterations. Regarding meiotic segregation, we found an incidence of disomies similar to that observed in control samples, whereas diploidy resulted higher in HCV patients, without reaching statistical significance. In conclusion, sperm quality in the studied group was not impaired, however, apoptosis and necrosis resulted out of normal range and the fertility index was significantly lower in HCV and HBV infected patients versus controls.

Count-rate analysis from clinical scans in PET with LSO detectors

The purpose of optimising the acquisition parameters in positron emission tomography is to improve the quality of the diagnostic images. Optimisation can be done by maximising the noise equivalent count rate (NECR) that in turn depends on the coincidence rate. For each bed position the scanner records coincidences and singles rates. For each patient, the true, random and scattered coincidences as functions of the single count rate(s) are determined by fitting the NEMA (National Electrical Manufacturers Association) 70 cm phantom count rate curves to measured clinical points. This enables analytical calculation of the personalised PNECR [pseudo NECR(s)] curve, linked to the NECR curve. For central bed positions, missing activity of approximately 70% is estimated to get maximum PNECR (PNECR(max)), but the improvement in terms of signal-toz-noise ratio would be approximately 15%. The correlation between patient weight and PNECR(max) is also estimated to determine the optimal scan duration of a single bed position as a function of patient weight at the same PNEC. Normalising the counts at PNECR(max) for the 70 kg patient, the bed duration for a 90 kg patient should be 230 s, which is approximately 30% longer. Although the analysis indicates that the fast scanner electronics allow using higher administered activities, this would involve poor improvement in terms of NECR. Instead, attending to higher bed duration for heavier patients may be more useful.