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Biomedical subjects

I Torres

Publications and source records attributed to I Torres.

At least 19 recordsLinked to original sources
PubMed2006

Genome size and ploidy of Paracoccidioides brasiliensis reveals a haploid DNA content: flow cytometry and GP43 sequence analysis.

The aim of this study was to evaluate genome size and ploidy of the dimorphic pathogenic fungus Paracoccidioides brasiliensis. The cell cycle analysis of 10 P. brasiliensis isolates by flow cytometry (FCM) revealed a genome size ranging from 26.3+/-0.1Mb (26.9+/-0.1fg) to 35.5+/-0.2Mb (36.3+/-0.2fg) per uninucleated yeast cell. The DNA content of conidia from P. brasiliensis ATCC 60855-30.2+/-0.8Mb (30.9+/-0.8fg) -showed no significant differences with the yeast form, possibly excluding the occurrence of ploidy shift during morphogenesis. The ploidy of several P. brasiliensis isolates was assessed by comparing genome sizing by FCM with the previously described average haploid size obtained from electrophoretic karyotyping. The analysis of intra-individual variability of a highly polymorphic P. brasiliensis gene, GP43, indicated that only one allele seems to be present. Overall, the results showed that all analysed isolates presented a haploid, or at least aneuploid, DNA content and no association was detected between genome size/ploidy and the clinical-epidemiological features of the studied isolates. This work provides new knowledge on P. brasiliensis genetics/genomics, important for future research in basic cellular/molecular mechanisms and for the development/design of molecular techniques in this fungus.

Antigens, Fungal↗
PubMed2006

The effects of morphine self-administration on cortical pyramidal cell structure in addiction-prone lewis rats.

The consumption of drugs of abuse provokes sensitization, the development of tolerance, dependency, and eventually addiction. It is thought that these events are partially a consequence of drug-induced alterations in the organization of neuronal circuits in specific areas of the brain. In the present study, we have used intracellular injections of lucifer yellow to examine the alterations that may occur in cortical pyramidal neurons of addiction-prone Lewis rats following 15 days of self-administration of morphine. Specifically, the effects of morphine on the structure, size and branching complexity of the basal dendrites, and spine density were determined in the basal dendritic arbors of layer III pyramidal neurons in both the prelimbic and motor cortex. We found that following morphine self-administration, there was a reduction in the size and branching complexity of the dendritic arbors of pyramidal cells in the motor cortex. In contrast, prelimbic pyramidal neurons from these morphine-treated animals had larger and longer basal dendritic arbors. Furthermore, the spine density on pyramidal neurons was higher in both cortical regions of morphine self-administered rats. These results suggest that at least part of the behavioral changes produced by repeated opiate administration may be attributed to alterations in pyramidal cell structure.

Analgesics, Opioid↗
PubMed2005

Low-temperature rotational relaxation of CO in self-collisions and in collisions with Ne and He.

The low-temperature rotational relaxation of CO in self-collisions and in collisions with the rare-gas atoms Ne and He has been investigated in supersonic expansions with a combination of resonance-enhanced multiphoton ionization (REMPI) spectroscopy and time-of-flight techniques. For the REMPI detection of CO, a novel 2 + 1' scheme has been employed through the A(1)Pi state of CO. From the measured data, average cross sections for rotational relaxation have been derived as a function of temperature in the range 5-100 K. For CO-Ne and CO-He, the relaxation cross sections grow, respectively, from values of approximately 20 and 7 A(2) at 100 K to values of approximately 65-70 and approximately 20 A(2) in the 5-20 K temperature range. The cross section for the relaxation of CO-CO grows from a value close to 40 A(2) at 100 K to a maximum of 60 A(2) at 20 K and then decreases again to 40 A(2) at 5 K. These results are qualitatively similar to those obtained previously with the same technique for N(2)-N(2), N(2)-Ne, and N(2)-He collisions, although in the low-temperature range (T < 20 K) the CO relaxation cross sections are significantly larger than those for N(2). Some discrepancies have been found between the present relaxation cross sections for CO-CO and CO-He and the values derived from electron-induced fluorescence experiments.

Journal Article↗
PubMed2005

Multiple pulmonary neoplasia positive for thyroglobulin.

We present, for the first time, a case of carcinoid metastatic pulmonary tumor positive for thyroglobulin. A 73-yr-old woman diagnosed with metastases of probable thyroid carcinoma, manifested by a mediastinic mass and multiple pulmonary nodules positive for radioiodine (I131). Histological analysis showed typical findings of carcinoid tumor with positive immunohistochemistry for neuron-specific enolase, synaptophysin and thyroglobulin, and negative for chromogranin and calcitonin. We underline the exceptional finding of positive reaction for thyroglobulin, and discuss difficulties in differential diagnosis between metastatic differentiated thyroid and carcinoid neoplasms.

Aged↗
PubMed2004

Observation of a narrow charm-strange meson D(+)(sJ)(2632)-->D(+)(s)eta and D(0)K(+).

We report the first observation of a charm-strange meson D(+)(sJ)(2632) at a mass of 2632.5+/-1.7 MeV/c(2) in data from SELEX, the charm hadro-production experiment E781 at Fermilab. This state is seen in two decay modes, D(+)(s)eta and D0K+. In the D(+)(s)eta decay mode we observe a peak with 101 events over a combinatoric background of 54.9 events at a mass of 2635.4+/-3.3 MeV/c(2). There is a corresponding peak of 21 events over a background of 6.9 at 2631.5+/-2.0 MeV/c(2) in the decay mode D0K+. The decay width of this state is <17 MeV/c(2) at 90% confidence level. The relative branching ratio Gamma(D0K+)/Gamma(D(+)(s)eta) is 0.14+/-0.06. The mechanism that keeps this state narrow is unclear. Its decay pattern is also unusual, being dominated by the D(+)(s)eta decay mode.

Journal Article↗
PubMed2004

Photodissociation and multiphoton dissociative ionization processes in CH(3)S(2)CH(3) at 193 nm studied using velocity-map imaging.

Dissociation and ionization processes in dimethyl disulfide, CH(3)S(2)CH(3), induced by one- or two-photon absorption of 193 nm light, have been studied using velocity-map ion imaging. The analysis of the ion images of the CH(3)S(2) (+), CH(3)S(+), S(2) (+), and S(+) fragments has allowed the characterization of the scattering dynamics of some of the main photolysis and dissociative-ionization processes. In particular, the experiments corroborate the formation of electronically excited SCH(3)((2)A(1)) products in the 193 nm photodissociation of dimethyl disulfide seen in earlier studies, and show that laser ionization provides a very sensitive method for their detection. The data have also allowed determination of the recoil energy and angular distributions of the CH(3)S(2) (+) and CH(3)S(+) products of the two-photon dissociative-ionization of the CH(3)S(2)CH(3) molecule. The measured distributions for these products are consistent with the formation of a transient parent ion which dissociates after a substantial intramolecular rearrangement, possibly yielding the most stable isomeric forms of the fragments, namely CH(2)S(2)H(+) and CH(2)SH(+).

Journal Article↗
PubMed2003

[Late postoperative amiodarone pulmonary toxicity].

Amiodarone is an effective antiarrhytmic drug and it is used to treat supraventricular or ventricular rhythm disturbances. Nevertheless it is not free from side effects. Acute amiodarone-induced pulmonary toxicity is one of them. We referred a 55-year-old man who started on amiodarone after a mitral valva replacement. Afterwards he had acute respiratory failure and diffuse ill-defined opacities. The diagnosis was confirmed by detection of lots of foamy macrophages in the bronchoalveolar lavage fluid. Relief of symptoms and arterial blood gases improvement was achieved when he started on corticosteroids and amiodarone treatment was stopped.

Amiodarone↗
PubMed2001

Decreased dopaminergic tone and increased basal bioactive prolactin in men with human immunodeficiency virus infection.

OBJECTIVE: The aims of the study were: (1) to assess dopaminergic tone in a group of HIV infected men and the bioactivity and the molecular species of their circulating PRL in comparison with healthy men and (2) to search for a correlation between serum PRL and CD4+ T lymphocytes and viral load. DESIGN: In a cross-sectional study the effect of acute dopaminergic blockade with intravenous metoclopramide on serum PRL (both immunoreactive and biologically active), TSH and PRL circulating molecular isoforms was evaluated. PATIENTS: Twenty untreated HIV infected men category C2 or C3, mean (SD) age 26.9 (6.3) years, were compared to 14 clinically healthy HIV-negative men, age 25.4 (2.3) years. MEASUREMENTS: Under fasting conditions and following metoclopramide administration duplicate measurements of serum immunoreactive PRL, bioactive PRL (PRL dependent Nb2 lymphoma cell assay) and immunoreactive TSH were performed. The molecular species of circulating PRL were determined by immunoblot analysis, CD4+ T lymphocytes by flow cytometry and the viral load using a nucleic acid sequence-based amplification assay. RESULTS: In HIV infected men fasting bioactive (but not immunoreactive) PRL was higher (P = 0.03), but the stimulated PRL (both immunoreactive and bioactive) was lower than in healthy men throughout the test (P < or = 0.01). Fasting serum TSH was similar in HIV-infected and healthy men while its response to metoclopramide was absent in the former but not in the latter (P = 0.049). A 23.5-kD PRL was the predominant circulating isoform both in patients and healthy men. Considering HIV-infected and healthy men, CD4+ T lymphocytes correlated negatively with fasting bioactive PRL (P = 0.008) and positively with the area under the PRL (both immunoreactive and bioactive) curves (P < 0.001). The viral load was negatively correlated with the area under the curve of the bioactive/immunoreactive ratio (P = 0.008). CONCLUSIONS: The raised fasting bioactive PRL, the diminished response of both immunoreactive and bioactive PRL and the absent TSH response to metoclopramide in HIV infected men, suggest the existence of a decreased, but not absent dopaminergic tone. A monomeric form of PRL was the predominant circulating species, as in healthy men, and this hormone seems to be associated both with CD4+ T lymphocytes and the viral load.

Adult↗
PubMed2001

Serum prolactin is associated with apoptosis in men with human immunodeficiency virus infection.

We examined the in vivo and in vitro production of prolactin (PRL) in 20 untreated HIV-infected men compared to 14 uninfected men and its association with the cell cycle and apoptosis. Compared to uninfected men, the HIV-infected men had: (i) higher fasting serum bioactive (BIO) PRL; (ii) lower serum immunoreactive (RIA) and BIO-PRL responses to intravenous metoclopramide; (iii) greater BIO-RIA PRL ratio both fasting and during intravenous metoclopramide; (iv) lower percentage of non-stimulated PBMC in the G0/G1 phase, but a higher percentage in the S phase, of the cell cycle with normal response to Concanavalin-A; and (v) higher in vitro production of BIO-PRL by non-stimulated PBMC, which was blocked after Concanavalin-A. Fasting serum BIO-PRL positively correlated with the percent of non-stimulated PBMC in S + G2/M phases. The percentage of apoptotic PBMC negatively correlated with CD4+ T lymphocytes and with the area under the serum RIA-PRL curve, but positively correlated with the area under the curve for the BIO/RIA ratio. These results suggest that in these HIV-infected men: (i) a diminished dopaminergic tone may exist, as an adaptive mechanism attempting to survive; and (ii) BIO-PRL may participate as a cofactor in the stimulation of T-cell proliferation.

Adult↗
PubMed2001

Is the depth correction using the geometric mean really necessary in a 99Tcm-DMSA scan in the paediatric population?

Determination of the left to right dimercaptosuccinic acid (DMSA) uptake ratio is theoretically one of the easiest quantitative procedures in nuclear medicine. The quantification can be performed on the posterior view, with or without the lateral view for correction of kidney depth. The geometric mean can also be determined using both the anterior and the posterior views. The aim of this study was to evaluate the occurrence of remarkable differences in the results from quantification of the relative renal function using the geometric mean and those obtained using the posterior counts only. Moreover, we evaluated to what extent the patient age influenced these differences. We reviewed 328 99Tcm-DMSA scans. The difference between the relative renal function obtained using the posterior view and that obtained using the geometric mean was calculated and analysed statistically. For the purpose of evaluating the value of performing the geometric mean calculation in patients of different ages, patients were divided into four age groups (group I, < or =2 years; group II, 3-9 years; group III, 10-18 years; group IV, >18 years). Using the Student's t test, no statistical differences were found in the relative renal function obtained by the two methods (posterior projection and geometric mean) in groups I (t = 0.01, P = 0.992) and II (t = 1.43, P = 0.155), which consisted of patients younger than 10 years (77% of the patients). In groups III and IV statistical differences were found (t = 2.27, P = 0.028 and t = 2.170, P = 0.038), respectively. We conclude that for children under 10 years it is unnecessary to perform depth correction using the geometric mean except in rare cases of major malformations and position anomalies.

Adolescent↗
PubMed2000

The importance of psychosocial factors in the prevention of HPV infection and cervical cancer.

This article presents a review of psychosocial factors associated with the primary and secondary prevention of cervical cancer. Current research evidence convincingly links the presence of the human papillomavirus (HPV) to the development of cervical cancer suggesting that bringing together knowledge from the Papanicolau smear screening and HPV infection research may help formulate a new approach that bridges primary and secondary prevention strategies. Bringing together these 2 areas of research involves an understanding of the psychosocial factors that underlie both. This review will specifically focus on 3 areas of psychosocial research: (1) sexual behaviours associated with HPV infection; (2) knowledge, attitudes and beliefs associated with Pap smear and HPV screening; and (3) the role of the medical provider in facilitating prevention activities.

Acculturation↗
PubMed1999

Modifications induced by dietary lipid source in adipose tissue phospholipid fatty acids and their consequences in lipid mobilization.

The aim of the present work was to assess the influence of dietary lipid source on fatty acid phospholipid profiles and on lipid mobilization. Forty male Wistar rats were divided into four groups and fed on high-fat diets which provided olive oil, sunflower oil, palm oil or beef tallow. All rats received the same amount of energy to avoid hyperphagia and differences in energy intake among groups. Phospholipid fatty acids were determined by GC. Lipolysis was stimulated in subcutaneous and perirenal isolated adipocytes by several lipolytic agents, and assessed by the determination of released glycerol. After 4 weeks of feeding, differences in body and adipose tissue weights were not observed. Dietary regimens caused great changes in adipose tissue phospholipid composition: rats fed on palm oil and beef tallow had higher concentrations of saturated fatty acids and animals fed on olive oil or sunflower oil had greater amounts of oleic and linoleic acids, respectively. These modifications did not lead to important changes in adipocyte lipolysis. Significant differences were only observed between palm-oil- and beef-tallow-fed groups when lipolysis was stimulated by isoproterenol in subcutaneous adipocytes. The fact that our feeding protocol did not induce differences in fat accumulation among groups avoids misinterpretations due to adiposity changes. The differences observed between both saturated-fat-fed groups, therefore, should only be attributable to dietary lipids. Despite this effect, the data from this work indicate that some diet-induced changes in adipose tissue fatty acid composition may have little effect on overall function.

Adipocytes↗
PubMed1997

The Latino Health Advocacy Program: a collaborative lay health advisor approach.

There have been numerous calls in the literature for health educators to develop programs to improve access to and utilization of health and human services by traditionally underserved communities, including Latinos. While the literature suggests several principles that can guide the development of these programs, it is important to address the needs, and build on the strengths, of the specific community of interest. It is, therefore, important to use collaborative approaches in which community members take an active role in the initiation, design, implementation, and evaluation of program activities. Lay health advisor programs are particularly well suited to this approach as they are designed to build on the strength of already existing community relationships to improve community health. This article describes a collaborative, culturally appropriate, holistic, and ecological lay health advisor program--the Latino Health Advocacy Program. Lessons learned and implications for future program development are discussed.

Community Health Services↗
PubMed1996

Influence of administration of long-chain polyunsaturated fatty acids on process of histological recovery in liver cirrhosis produced by oral intake of thioacetamide.

Patients with liver cirrhosis frequently show some degree of protein-energy malnutrition and obviously require nutritional support. In this study, the treatment of rats consisted of the ad libitum oral intake of a 300 mg/liter thioacetamide solution, used as drinking water for four months. Thioacetamide treatment produced a severe alteration in the plasma fatty acid profile with significant decreases of these, which mimicked changes described in human cirrhosis. This hepatotoxic agent causes nodular cirrhosis, with loss of the normal architecture of the liver and disruption of the vascular pattern. The goal of the study was to evaluate the influence of n-3 and n-6 series long-chain polyunsaturated fatty acid dietary supplementation in experimental animals and to assess the effects of those dietary components on structural recovery in the liver. Significant increases of saturated and monounsaturated fatty acids as well as n-6 polyunsaturated fatty acids were seen only in the animals given the n-6 polyunsaturated fatty acid supplemented diet. However, only rats given the standard diet exhibited some degree of histological regeneration.

Animals↗
PubMed1995

Brain morphology in first-episode schizophrenia.

OBJECTIVE: Neuroimaging studies have provided robust evidence that schizophrenia is associated with structural brain abnormalities. However, the underlying pathophysiology of these changes is still unknown. By evaluating brain morphology early in the course of illness, confounding effects of treatment and duration of illness are minimized. The goal of this study was to evaluate brain structure in patients early in the course of schizophrenia who had received no or minimal neuroleptics. METHOD: Magnetic resonance imaging was used to evaluate 12 male and 12 female patients experiencing their first episode of schizophrenia (mean duration of psychotic episode = 14 weeks) and 12 male and 12 female normal volunteers equivalent in age, height, and parents' socioeconomic status. A totally automated method was used to analyze scans, yielding volumes of brain tissue and CSF, divided into lobes. RESULTS: The patient group had significantly more total CSF than the comparison subjects. This was accounted for by higher levels of intersulcal CSF as well as ventricular CSF. There were no differences in total volume of brain tissue between the two groups, but patients had a significant regionally specific decrement in frontal lobe tissue compared with the normal subjects. CONCLUSIONS: These findings indicate that structural brain abnormalities are present very early in schizophrenia and may not be due to factors such as treatment or chronicity of illness. Rather, since the abnormalities are present near the onset of the illness, a neurodevelopmental mechanism may be suggested.

Adult↗