Rafael Torres

Effect of simultaneous use of highly active antiretroviral therapy on survival of HIV patients with tuberculosis.

Introduction:The optimal timing for initiation of highly active antiretroviral therapy (HAART) in patients with AIDS and tuberculosis (TB) is an unresolved question. To assess the effect of HAART on the survival of patients with TB, we designed this study. Methods:We selected all HIV patients included in the COMESEM cohort with TB diagnosis after 1996. Clinical and epidemiological data were registered. We compared patients who started HAART at the diagnosis of TB [simultaneous therapy (ST)] or not. Survival was assessed by Cox analysis. Results:Among the 6934 HIV patients included in the cohort, 1217 patients had TB, 322 of them (26.5%) after 1996. At the time of TB diagnosis, 45% of them started HAART (ST). There were no differences between groups regarding basal characteristics, except for a lower viral load in ST patients. ST therapy was associated with improved survival (hazard ratio 0.38; 95% confidence interval 0.20 to 0.72, P = 0.003). By univariate analysis, survival was also associated with no endovenous drug use and a later year of TB diagnosis. After adjusting for other prognostic variables, by Cox multivariate analysis, ST remained robustly associated with improved survival (hazard ratio 0.37; 95% confidence interval 0.17 to 0.66, P = 0.001). Conclusions:Simultaneous HAART and TB treatment in HIV patients with TB is associated with improved survival.

Fractional convolution, fractional correlation and their translation invariance properties

The fractional convolution and correlation of two functions, as usually defined, exhibit only partial invariance properties which prevent their actual use in many applications of signal processing. Indeed, an effective translation invariance is obtained by slightly modifying the former definitions and by introducing fractional translation operators. The translation invariances of the so-defined fractional convolution and correlation are expressed by integrals which are shown to be the exact counterparts, in the fractional domain, of the integrals that are used to express the well-known translation invariances of the usual convolution and correlation. The former theoretical results are applied to proving a fractional sampling theorem and are illustrated by numerical simulations. They are also compared to those obtained by some authors on the basis of alternative definitions.

Fractional Fourier Analysis of Random Signals and the Notion of /spl alpha/-Stationarity of the Wigner - Ville Distribution

In this paper, a generalized notion of wide-sense α-stationarity for random signals is presented. The notion of stationarity is fundamental in the Fourier analysis of random signals. For this purpose, a definition of the fractional correlation between two random variables is introduced. It is shown that for wide-sense α -stationary random signals, the fractional correlation and the fractional power spectral density functions form a fractional Fourier transform pair. Thus, the concept of α -stationarity plays an important role in the analysis of random signals through the fractional Fourier transform for signals nonstationary in the standard formulation, but α -stationary. Furthermore, we define the α-Wigner-Ville distribution in terms of the fractional correlation function, in which the standard Fourier analysis is the particular case for α = π/2 , and it leads to the Wiener-Khinchin theorem.

Higher vitamin D levels in HIV‐infected out‐patients on treatment with boosted protease inhibitor monotherapy

We investigated the vitamin D status of patients receiving frequently used types of combination antiretroviral therapy (cART), including boosted protease inhibitor (PI) monotherapy.

The changing pattern of tuberculosis and HIV co-infection in immigrants and Spaniards in the last 20 years

To evaluate the impact of immigration on tuberculosis (TB)–HIV co‐infection in Spain in a prospective cohort of HIV patients.

Antimicrobial treatment of invasive non-perinatal human listeriosis and the impact of the underlying disease on prognosis

Listeriosis is a resurgent foodborne disease in European countries. Benefits of combined β-lactam-aminoglycoside treatment remain controversial and the impact of the underlying disease on prognosis has not been fully assessed. We conducted a retrospective review of cases of sporadic listeriosis in adults from 1995 to 2008 at two university-affiliated hospitals serving a population of 600,000 people in Madrid, Spain. The primary end-point was the associated in-hospital mortality. Sixty-four patients were studied. Estimated incidence of listeriosis was 0.76/100.000 persons/year. Seventy-four per cent had chronic underlying diseases; cirrhosis of the liver and haematological and solid neoplasias were the most common comorbidities. Primary bacteraemia (58%) and meningitis (42%) were the most frequent manifestations. Focal infections were seen in ten cases. In-hospital mortality was 31%. Patients treated with ampicillin or with an ampicillin-gentamicin combination did not differ in age, severity of underlying disease or type of presentation. Differences in mortality were not seen between patients treated with monotherapy and those given combined treatment (28% vs 35%; p 0.634). Ten patients were treated with trimethoprim-sulfamethozaxole alone and only one died. All patients without comorbidities survived infection but mortality of patients with cirrhosis of the liver was 21% and that of patients with haematological or solid neoplasias was 66%. Only haematological neoplasia (OR 6.67; 95% CI 1.71-26.04; p 0.006) was significantly associated with an increased risk of mortality (R(2) (Cox-Snell) = 0.262). Mortality of listeriosis mainly depended on the severity of the underlying disease. Combined ampicillin-gentamicin therapy did not improved survival. Trimethoprim-sulfamethozaxole may be an effective alternative therapy for listerial infections.

Fractional Sampling Theorem for

Considering that fractional correlation function and the fractional power spectral density, for α-stationary random signals, form a fractional Fourier transform pair. We present an interpolation formula to estimate a random signal from a temporal random series, based on the fractional sampling theorem for α-bandlimited random signals. Furthermore, by establishing the relationship between the sampling theorem and the von Neumann ergodic theorem, the estimation of the power spectral density of a random signal from one sample signal becomes a suitable approach. Thus, the validity of the sampling theorem for random signals is closely linked to an ergodic hypothesis in the mean sense.

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In August 2009, an ad hoc international expert committee created by the major world diabetic association, published an eagerly awaited consensus. In this, it recommended the general use of the haemoglobin A1c fraction for the diagnosis of diabetes, encouraging its standardisation and proposing a 6.5% cut-off. In this article, the diagnostic methods for diabetes, as well as the advantages, limitations and controversies of this new recommendation are reviewed.In August 2009, an ad hoc international expert committee created by the major world diabetic association, published an eagerly awaited consensus. In this, it recommended the general use of the haemoglobin A1c fraction for the diagnosis of diabetes, encouraging its standardisation and proposing a 6.5% cut-off. In this article, the diagnostic methods for diabetes, as well as the advantages, limitations and controversies of this new recommendation are reviewed.

-Bandlimited Random Signals and Its Relation to the von Neumann Ergodic Theorem

Periodically shifting replicas of a function is equivalent to sampling its standard Fourier transform, but not its general fractional order Fourier transform. Indeed, sampling in the fractional domain can be achieved after defining fractional shift operators and a fractional convolution product. Standard formulae that hold true for standard operations can be generalized to the fractional calculus. A proof of the fractional sampling theorem is derived by using the former operators and the theorem is applied to computing digital holograms that work in the Fresnel regime. A condition for optimizing the distance between a diffracting object and the diffracted pattern detected by a discrete device is also given: it allows for sampling at an appropriate rate which is in accordance with the detector cell period as well as with the sampling theorem and interpolation formula.

Glicada para el diagnóstico de la diabetes, ¿un estándar universal?

This paper presents a time-variant filtering based on a notion of fractional convolution and its relation with α-Wigner-Ville distribution. Additionally, some properties of the α-Wigner-Ville distribution are studied. These properties also demonstrate that conventional theory based on Fourier Analysis is a particular case of the theory proposed in this paper. Finally, the paper wraps up showing that this development may lead to an adaptive filtering technique, thus extending their range of application. HighlightsThe properties of α-Wigner-Ville (α-WVD) distribution are studied.The association between fractional power spectral density and α-WVD is established.It is proved that fractional convolution (FrC) is a time-variant (TV) operation.Based on FrC was proposed a method for TV filtering for non-stationary signals.The methodology for more general signals, whose WVD have curved supports, is adapted.