Biomedical subjects

Cecilia Castro

Publications and source records attributed to Cecilia Castro.

7 recordsLinked to original sources

PubMed2006

Postmortem findings and opportunistic infections in HIV-positive patients from a public hospital in Peru.

There is a paucity of HIV autopsy data from South America and none that document the postmortem findings in patients with HIV/AIDS in Peru. The purpose of this autopsy study was to determine the spectrum of opportunistic infections and the causes of mortality in HIV-positive patients at a public hospital in Lima. Clinico-epidemiological information regarding HIV infection in Peru is also reviewed. Sixteen HIV-related hospital postmortems, performed between 1999 and 2004, were included in this retrospective analysis. The primary cause of death was established in 12 patients: one died of neoplasia and 11 of infectious diseases, including 3 from pulmonary infection, 7 from disseminated infection, and 2 from central nervous system infection (one case had dual pathology). Opportunistic infections were identified in 14 cases, comprising cytomegalovirus, histoplasmosis, cryptococcosis, toxoplasmosis, Pneumocystis pneumonia, aspergillosis, tuberculosis, varicella zoster virus, and cryptosporidiosis. Fourteen patients had at least one AIDS-related disease that had been neither clinically suspected nor diagnosed premortem. Moreover, 82% of the diagnoses considered to be of important clinical significance had not been suspected antemortem. The spectrum and frequency of certain opportunistic infections differed from other South American autopsy studies, highlighting the importance of performing HIV/AIDS postmortems in resource-limited countries where locally specific disease patterns may be observed.

AIDS-Related Opportunistic Infections↗

PubMed2006

Obtaining informed consent for genetic studies: The multiethnic study of atherosclerosis.

Studies of DNA may yield important information about atherosclerosis. To determine how often study participants' consent to examine DNA is denied and the factors associated with that denial, information was collected on participants in the US Multiethnic Study of Atherosclerosis (MESA) during 2000-2004. Permission was sought for preparation of DNA, transformation of cells into cell lines, evaluation of genes related to heart and other health conditions, and access to DNA by private companies. Of the 5,494 participants at entry, 897 (16.3%) refused consent for some items and 247 (4.5%) completely denied consent. At a second examination 18 months later, 819 (15.0%) partially refused and 229 (4.2%) completely denied consent. Age among men (odds ratio per 10 years = 0.68, 95% confidence interval: 0.54, 0.85; p = 0.004), ethnicity (odds ratio for African American = 2.34, 95% confidence interval: 1.66, 3.32; p < 0.001), and field center (p < 0.001) were associated with complete denial. For those giving partial consent, the most common item refused was access to DNA by private companies (baseline: 99%; second examination: 90%); younger age, male gender, and African-American ethnicity were associated with refusal. The authors concluded that a small percentage of participants in epidemiologic studies refuse consent for DNA studies, and the majority are concerned about sharing their DNA data with industry.

Age Factors↗

PubMed2006

A metabonomic study of transgenic maize (Zea mays) seeds revealed variations in osmolytes and branched amino acids.

The aim of the research was to investigate metabolic variations associated with genetic modifications in the grains of Zea mays using metabonomic techniques. With this in mind, the non-targeted characteristic of the technique is useful to identify metabolites peculiar to the genetic modification and initially undefined. The results obtained showed that the genetic modification, introducing Cry1Ab gene expression, induces metabolic variations involving the primary nitrogen pathway. Concerning the methodological aspects, the experimental protocol used has been applied in this field for the first time. It consists of a combination of partial least square-discriminant analysis and principal component analysis. The most important metabolites for discrimination were selected and the metabolic correlations linking them are identified. Principal component analysis on selected signals confirms metabolic variations, highlighting important details about the changes induced on the metabolic network by the presence of a Bt transgene in the maize genome.

Amino Acids, Branched-Chain↗

PubMed2006

Retinal vascular caliber, cardiovascular risk factors, and inflammation: the multi-ethnic study of atherosclerosis (MESA).

PURPOSE: To describe the relationship of retinal arteriolar and venular caliber with cardiovascular risk factors, including inflammatory biomarkers, in a multiethnic population of whites, blacks, Hispanics, and Chinese. METHODS: A cross-sectional study comprising 5979 persons aged 45 to 84 years residing in six U.S. communities. Retinal vascular caliber was measured and summarized from digital retinal photographs. Standard cardiovascular risk factors, including biomarkers of inflammation (e.g., high-sensitivity C-reactive protein [hsCRP], interleukin [IL]-6, and plasma fibrinogen) and endothelial dysfunction (e.g., soluble intercellular adhesion molecule [sICAM]-1 [, plasminogen activator inhibitor [PAI]-1) were assessed. RESULTS: Mean retinal arteriolar caliber was 144.1+/-14.4 (SD) microm, and venular caliber 214.0+/-22.2 microm. In models controlling for age, gender, race-ethnicity, and center, smaller retinal arteriolar caliber was related to higher systolic and diastolic blood pressure, hypertension status, current alcohol consumption, greater body mass index, and higher levels of total homocysteine; larger retinal arteriolar caliber was related to diabetes, current cigarette smoking, and higher levels of plasma fibrinogen; and larger retinal venular caliber was related to diabetes, current cigarette smoking, greater body mass index and waist-hip ratio, higher levels of serum glucose, plasma triglyceride, plasma LDL-cholesterol, hsCRP, plasma fibrinogen, IL6, sICAM-1, and PAI-1 and lower levels of HDL-cholesterol. In multivariate analyses, blacks and Hispanics had larger retinal arteriolar and venular calibers than did whites and Chinese. CONCLUSIONS: Retinal arteriolar and venular caliber is associated with a range of cardiovascular risk factors, including hypertension, diabetes, measures of obesity, and dyslipidemia. Venular caliber is also associated with systemic inflammation.

Arterioles↗

PubMed2005

LF-NMR and multivariate data analysis: compression of data to classify hydrogel contact lenses.

Hydrogel contact lenses swollen in viscoelastic artificial tears solution have been studied, measuring transversal relaxation times of water molecules using LF-NMR techniques. Data were processed by classical multiexponential fitting, by principal component analysis and by SLICING, a multi-way analysis method. The reason for using multivariate data analysis was not to obtain a better fitting, but rather more effective data description. The single-sample relaxation curves were projected in a space spanned by the loading curves, and in this space it was simpler to compare data. In particular, it contributed to the description of the variability of motion characteristics of the water molecule 'families' contained in the studied samples. Applying multivariate techniques, we were able to group lenses with different Equilibrium Water Content (EWC) and with the same water content but different compositions. Accordingly, we were able to point out that, if the lenses are swollen first in physiological solution and then in viscoelastic artificial tears solution, hydration characteristics remained unchanged in all the studied samples, except for 38% EWC lenses.

Algorithms↗

PubMed2004

Application of trilinear SLICING to analyse a single relaxation curve.

Determining the time constants and amplitudes of exponential decays from relaxation data is a common task in LF-NMR. In this communication, we present an application of the SLICING algorithm to evaluate its possibilities for solving this problem. The method, originally introduced to compare different samples, is applied here to analyse a single relaxation curve, using the embedding technique. To test this procedure, we acquired data sets from samples of liquids properly separated, and characterized by different relaxation times. The results show a good estimation of parameters, comparable with those obtained applying Marquardt's algorithm, when the components have sufficiently different relaxation times.

Journal Article↗

PubMed2004

NMR-based metabonomic study of transgenic maize.

The aim of this research was to verify the possibility of identifying and classifying maize seeds obtained from transgenic plants, in different classes according to the modification, on the basis of the concerted variation in metabolite levels detected by NMR spectra. It was possible to recognise the discriminant metabolites of transgenic samples as well as to classify non-a priori defined samples of maize. It is important to underline that the obtained results are useful to point out the metabolic consequences of a specific genic modification on a plant, without using a targeted analysis of the different metabolites, in fact it was possible to classify the seeds also without the complete assignment of the spectra. The analysis was performed by applying multivariate techniques (principal component analysis and partial least squares-discriminant analysis) to NMR data.

Gene Expression↗