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Search Results: 1 - 10 of 4367 matches for " Lorenzo Zammarchi "
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CLINICAL ASPECTS OF UNCOMPLICATED AND SEVERE MALARIA
Alessandro Bartoloni,Lorenzo Zammarchi
Mediterranean Journal of Hematology and Infectious Diseases , 2012, DOI: 10.4084/mjhid.2012.
Abstract: The first symptoms of malaria, common to all the different malaria species, are nonspecific and mimic a flu-like syndrome. Although fever represents the cardinal feature, clinical findings in malaria are extremely diverse and may range in severity from mild headache to serious complications leading to death, particularly in falciparum malaria. As the progression to these complications can be rapid, any malaria patient must be assessed and treated rapidly, and frequent observations are needed to look for early signs of systemic complications. In fact, severe malaria is a life threatening but treatable disease. The protean and nonspecific clinical findings occurring in malaria (fever, malaise, headache, myalgias, jaundice and sometimes gastrointestinal symptoms of nausea, vomiting and diarrhoea) may lead physicians who see malaria infrequently to a wrong diagnosis, such as influenza (particularly during the seasonal epidemic flu), dengue, gastroenteritis, typhoid fever, viral hepatitis, encephalitis. Physicians should be aware that malaria is not a clinical diagnosis but must be diagnosed, or excluded, by performing microscopic examination of blood films. Prompt diagnosis and appropriate treatment are then crucial to prevent morbidity and fatal outcomes. Although Plasmodium falciparum malaria is the major cause of severe malaria and death, increasing evidence has recently emerged that Plasmodium vivax and Plasmodium knowlesi can also be severe and even fatal.
Epilepsy and Neurocysticercosis in Latin America: A Systematic Review and Meta-analysis
Elisa Bruno,Alessandro Bartoloni,Lorenzo Zammarchi,Marianne Strohmeyer,Filippo Bartalesi,Javier A. Bustos,Saul Santiva?ez,Héctor H. García,Alessandra Nicoletti ,the COHEMI Project Study Group
PLOS Neglected Tropical Diseases , 2013, DOI: 10.1371/journal.pntd.0002480
Abstract: Background The difference in epilepsy burden existing among populations in tropical regions has been attributed to many factors, including the distribution of infectious diseases with neurologic sequels. To define the burden of epilepsy in Latin American Countries (LAC) and to investigate the strength of association with neurocysticercosis (NCC), considered one of the leading causes of epilepsy, we performed a systematic review and meta-analysis of the literature. Methodology Studies published until 2012 were selected applying predefined inclusion criteria. Lifetime epilepsy (LTE) prevalence, active epilepsy (AE) prevalence, incidence, mortality, treatment gap (TG) and NCC proportion among people with epilepsy (PWE) were extracted. Median values were obtained for each estimate using random effects meta-analysis. The impact of NCC prevalence on epilepsy estimates was determined using meta-regression models. To assess the association between NCC and epilepsy, a further meta-analysis was performed on case-control studies. Principal findings The median LTE prevalence was 15.8/1,000 (95% CI 13.5–18.3), the median AE prevalence was 10.7/1,000 (95% CI 8.4–13.2), the median incidence was 138.2/100,000 (95% CI 83.6–206.4), the overall standardized mortality ratio was 1.4 (95% CI 0.01–6.1) and the overall estimated TG was 60.6% (95% CI 45.3–74.9). The median NCC proportion among PWE was 32.3% (95% CI 26.0–39.0). Higher TG and NCC estimates were associated with higher epilepsy prevalence. The association between NCC and epilepsy was significant (p<0.001) with a common odds ratio of 2.8 (95% CI 1.9–4.0). Significance A high burden of epilepsy and of NCC in LAC and a consistent association between these two diseases were pointed out. Furthermore, NCC prevalence and TG were identified as important factors influencing epilepsy prevalence to be considered in prevention and intervention strategies.
Epidemiology and Management of Cysticercosis and Taenia solium Taeniasis in Europe, Systematic Review 1990–2011
Lorenzo Zammarchi, Marianne Strohmeyer, Filippo Bartalesi, Elisa Bruno, José Mu?oz, Dora Buonfrate, Alessandra Nicoletti, Héctor Hugo García, Edoardo Pozio, Alessandro Bartoloni, The COHEMI Project Study Group
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0069537
Abstract: Background Cysticercosis is caused by the invasion of human or pig tissues by the metacestode larval stage of Taenia solium. In Europe, the disease was endemic in the past but the autochthonous natural life cycle of the parasite is currently completed very rarely. Recently, imported cases have increased in parallel to the increased number of migrations and international travels. The lack of specific surveillance systems for cysticercosis leads to underestimation of the epidemiological and clinical impacts. Objectives To review the available data on epidemiology and management of cysticercosis in Europe. Methods A review of literature on human cysticercosis and T. solium taeniasis in Europe published between 1990–2011 was conducted. Results Out of 846 cysticercosis cases described in the literature, 522 cases were autochthonous and 324 cases were imported. The majority (70.1%) of the autochthonous cases were diagnosed in Portugal from 1983 and 1994. Imported cases of which 242 (74.7%) diagnosed in migrants and 57 (17.6%) in European travellers, showed an increasing trend. Most of imported cases were acquired in Latin America (69.8% of migrants and 44.0% of travellers). The majority of imported cases were diagnosed in Spain (47.5%), France (16.7%) and Italy (8.3%). One third of neurosurgical procedures were performed because the suspected diagnosis was cerebral neoplasm. Sixty eight autochthonous and 5 imported T. solium taeniasis cases were reported. Conclusions Cysticercosis remains a challenge for European care providers, since they are often poorly aware of this infection and have little familiarity in managing this disease. Cysticercosis should be included among mandatory reportable diseases, in order to improve the accuracy of epidemiological information. European health care providers might benefit from a transfer of knowledge from colleagues working in endemic areas and the development of shared diagnostic and therapeutic processes would have impact on the quality of the European health systems. Key words: cysticercosis, neurocysticercosis, Taenia solium, taeniasis, Europe, travellers, migrants.
5′ UTR Control of Native ERG and of Tmprss2:ERG Variants Activity in Prostate Cancer
Francesca Zammarchi, George Boutsalis, Luca Cartegni
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0049721
Abstract: ERG, a member of the ETS transcription factor family, is frequently overexpressed in prostate cancer as a result of its fusion to the androgen-responsive Tmprss2 gene. Different genomic rearrangements and alternative splicing events around the junction region lead to multiple combination of Tmprss2:ERG fusion transcripts that correlate with different tumor aggressiveness, but their specific functions and biological activities are still unclear. The complexity of ERG expression pattern is compounded by the use of alternative promoters, splice sites, polyadenylation sites and translation initiation sites in both the native and fusion contexts. Our systematic characterization of native ERG and Tmprss2:ERG variants reveals that their different oncogenic potential is impacted by the status of the Ets domain and the configuration of the 5′ UTR region. In particular, expression and activity of functional ERG and Tmprss2:ERG variants are influenced both by translation initiation signals within the different isoforms and by inhibitory upstream Open Reading Frames (uORF) in their 5′ UTRs. Stable expression of ERG and Tmprss2:ERG variants promoted cell migration/invasion, induced a block of proliferation and induced a senescence-like state, suggesting a role for these variants in the prostate tumorigenesis process. In addition to Tmprss2:ERG fusion products, a group of related native ERG isoforms is also highly over-expressed in fusion-carrying prostate cancers, and share the same translation initiation site (in ERG exon 4) with the commonly observed Tmprss2 exon1 joined to ERG exon 4 (T1:E4) fusion-derived variant. Usage of this ATG can be preferentially down-regulated by directed antisense-based compounds, possibly representing the basis of a targeted approach that distinguishes between tumor–associated and normal ERG.
Is it plausible to expect a close encounter of the Earth with a yet undiscovered astronomical object in the next few years?  [PDF]
Lorenzo Iorio
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.211146
Abstract: We analytically and numerically investigate the possibility that a still undiscovered body X, moving along an unbound hyperbolic path from outside the solar system, may penetrate its inner regions in the next few years posing a threat to the Earth. By conservatively using as initial position of X the lower bounds on the present‐day distance of X dynamically inferred from the gravitational perturbations induced by it on the orbital motions of the planets of the solar system, both the analyses show that, in order to reach the Earth’s orbit in the next 2 yr, X should move at a highly unrealistic speed , whatever its mass is. For example, by assuming for it a solar ( M ) or brown dwarf mass ( ), now at not less than kau (1 kau=1000 astronomical units), v would be of the order of and of the speed of light c, respectively. By assuming larger present‐day distances for X, on the basis of the lacking of direct observational evidences of electromagnetic origin for it, its speed would be even higher. Instead, the fastest solitary massive objects known so far, like hypervelocity stars (HVSs) and supernova remnants (SRs), travel at , having acquired so huge velocities in some of the most violent astrophysical phenomena like interactions with supermassive galactic black holes and supernova explosions. It turns out that the orbit of the Earth would not be macroscopically altered by a close (0.2 au) passage of such an ultrafast body X in the next 2 yr. On the contrary, our planet would be hurled into the space if a Sun‐sized body X would encounter it by moving at . On the other hand, this would imply that such a X should be now at just 20-30 au, contrary to all direct observational and indirect dynamical evidences.
On Some Critical Issues of the LAGEOS-Based Tests of the Lense-Thirring Effect  [PDF]
Lorenzo Iorio
Journal of Modern Physics (JMP) , 2011, DOI: 10.4236/jmp.2011.24029
Abstract: We summarize some critical issues pertaining the tests of the general relativistic Lense-Thirring effect performed by I. Ciufolini and coworkers in the gravitational field of the Earth with the geodetic satellites LAGEOS and LAGEOS II tracked with the Satellite Laser Ranging technique.
On Possible A-Priori “Imprinting” of General Relativity Itself on the Performed Lense-Thirring Tests with LAGEOS Satellites  [PDF]
Lorenzo Iorio
Communications and Network (CN) , 2010, DOI: 10.4236/cn.2010.21003
Abstract: The impact of possible a-priori “imprinting” effects of general relativity itself on recent attempts to measure the general relativistic Lense-Thirring effect with the LAGEOS satellites orbiting the Earth and the terrestrial geopotential models from the dedicated mission GRACE is investigated. It is analytically shown that general relativity, not explicitly solved for in the GRACE-based models, may “imprint” their even zonal harmonic coeffi-cients of low degrees at a non-negligible level, given the present-day accuracy in recovering them. This trans-lates into a bias of the LAGEOS-based relativistic tests as large as the Lense-Thirring effect itself. Further analyses should include general relativity itself in the GRACE data processing by explicitly solving for it.
Orbital effects of Sun’s mass loss and the Earth’s fate  [PDF]
Lorenzo Iorio
Natural Science (NS) , 2010, DOI: 10.4236/ns.2010.24041
Abstract: I calculate the classical effects induced by an isotropic mass loss of a body on the orbital motion of a test particle around it; the present analysis is also valid for a variation of the Newtonian constant of gravitation. I perturbatively obtain negative secular rates for the osculating semimajor axis a, the eccentricity e and the mean anomaly , while the argument of pericenter ω does not undergo secular precession, like the longitude of the ascending node Ω and the inclination I. The anomalistic period is different from the Keplerian one, being larger than it. The true orbit, instead, expands, as shown by a numerical integration of the equations of motion in Cartesian coordinates; in fact, this is in agreement with the seemingly counter-intuitive decreasing of a and e because they only refer to the osculating Keplerian ellipses which approximate the trajectory at each instant. By assuming for the Sun it turns out that the Earth's perihelion position is displaced outward by 1.3 cm along the fixed line of apsides after each revolution. By applying our results to the phase in which the radius of the Sun, already moved to the Red Giant Branch of the Hertzsprung-Russell Diagram, will become as large as 1.20 AU in about 1 Myr, I find that the Earth's perihelion position on the fixed line of the apsides will increase by AU (for ); other researchers point towards an increase of AU. Mercury will be destroyed already at the end of the Main Sequence, while Venus should be engulfed in the initial phase of the Red Giant Branch phase; the orbits of the outer planets will increase by AU. Simultaneous long-term numerical integrations of the equations of motion of all the major bodies of the solar system, with the inclusion of a mass-loss term in the dynamical force models as well, are required to check if the mutual N-body interactions may substantially change the picture analytically outlined here, especially in the Red Giant Branch phase in which Mercury and Venus may be removed from the integration.
The Relativistic Three-Dimensional Evolution of SN 1987A  [PDF]
Lorenzo Zaninetti
International Journal of Astronomy and Astrophysics (IJAA) , 2014, DOI: 10.4236/ijaa.2014.42030
Abstract:

The high velocities observed in supernovae require a relativistic treatment for the equation of motion in the presence of gradients in the density of the interstellar medium. The adopted theory is that of the thin layer approximation. The chosen medium is auto-gravitating with respect to an equatorial plane. The differential equation which governs the relativistic conservation of momentum is solved numerically and by recursion. The asymmetric field of relativistic velocities as well the time dilation is plotted at the age of 1 yr for SN 1987A.

Classical and Relativistic Flux of Energy Conservation in Astrophysical Jets  [PDF]
Lorenzo Zaninetti
Journal of High Energy Physics, Gravitation and Cosmology (JHEPGC) , 2016, DOI: 10.4236/jhepgc.2016.21005
Abstract: The conservation of the energy flux in turbulent jets which propagate in the intergalactic medium (IGM) allows deducing the law of motion in the classical and relativistic cases. Three types of IGM are considered: constant density, hyperbolic and inverse power law decrease of density. An analytical law for the evolution of the magnetic field along the radio-jets is deduced using a linear relation between the magnetic pressure and the rest density. Astrophysical applications are made to the centerline intensity of synchrotron emission in NGC315 and to the magnetic field of 3C273.
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