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Biomedical subjects

A Guerra

Publications and source records attributed to A Guerra.

At least 19 recordsLinked to original sources
PubMed2006

[Preliminary results of DERMATEL: prospective randomized study comparing synchronous and asynchronous modalities of teledermatology].

INTRODUCTION: There is considerable variability in the results of studies that evaluate diagnostic reliability in teledermatology. There are only two studies that compare the synchronous and asynchronous modalities of teleconsult in the same sample. We present the results of the pilot project DERMATEL, a study of diagnostic concordance that aims to increase the evidence of these aspects. MATERIAL AND METHODS: One-hundred-fifty.nine patients referred by the general practitioner in the first consult were randomized (algorithm 3:2:1) in three arms: asyncronous teledermatology (store-and-forward or SAF), synchronous teldermatology (real-time or VTC), and conventional consult (CC). We used high-quality, fixed digital images in all cases. The patients on the VTC teledermatology arm were also evaluated by videoconference. Finally all patients attended a face-to-face consult, considered the gold standard of patient care. A second dermatologist evaluated the diagnostic and management concordance between the teleconsults and the face-to-face consults. RESULTS: One-hundred.forty-seven patients completed the study as follows: 74 in the SAF teledermatology arm, 47 in the VTC teledermatology arm and 26 in the conventional consult (control group). The teledermatological (SAF and VTC) and face-to-face evaluations were identical in 100 of 121 patients (82.6%). The errors were mild in 14 cases (11.6%) and severe in 7 (5.8%). The diagnostic concordance was very high (kappa=0,813). The errors grouped by diseases were as follows: 6/54 (11%) for tumors, 10/30 (33.3%) for inflammatory conditions, 1/20 (5%) for infectious diseases, 3/12 (25%) for alopecia/acne and 1/5 (20%) for others. There were 15 errors in the SAF teledermatology arm (20.3%) and 6 in the VTC teledermatology arm (12.8%); these differences were not statistically significant (chi2 1.12; p=0.288). CONCLUSION: The reliability of dermatological teleconsult is very high, especially for tumoral or infectious diseases. The synchronous interaction with audio requires more resources, is difficult to coordinate and its diagnostic efficacy is not superior to SAF teledermatology.

Adolescent↗
PubMed2006

Increased expression of Ob-Rb and its relationship with the overexpression of TGF-beta1 and the stage of fibrosis in patients with nonalcoholic steatohepatitis.

AIMS: The main aim of this study was to examine the relationship of the leptin system in steatosis and nonalcoholic steatohepatitis (NASH). The study also analysed the pathogenic role of the leptin system in the development of hepatic fibrosis and its relation with the TGF-beta1 system. MATERIALS AND METHODS: The study included 90 subjects, 55 with NASH and 35 with simple steatosis. Gene expression of leptin, leptin receptor and TGF-beta mRNA was analysed by real-time PCR on liver tissue. Leptin serum levels were determined by RIA. Leptin receptor expression was also assessed by immunohistochemistry. RESULTS: Increased expression was found for leptin receptor mRNA (P=0.0016) and its protein (P<0.05) in patients with NASH, especially those with fibrosis. There was a marked increase in gene expression of TGF-beta1 in patients with NASH (P=0.0002). A strong correlation was demonstrated between leptin receptor gene expression and TGF-beta1 gene expression (P=0.023). No leptin expression was found in the liver tissue. All patients showed a marked hyperleptinemia, which was closely related to the anthropometric characteristics analysed and independent of development or not of NASH. CONCLUSIONS: The results of the study demonstrate for the first time increased leptin receptor expression in liver tissue and its relationship with overexpression of TGF-beta1 and the degree of hepatic fibrosis.

Adult↗
PubMed2006

A pilot study of nurse-led, home monitoring for patients with chronic respiratory failure and with mechanical ventilation assistance.

We assessed the feasibility of telemedicine for home monitoring of 45 patients with chronic respiratory failure (CRF) discharged from hospital. The patients transmitted pulsed arterial saturation (pSat) data via a telephone modem to a receiving station where a nurse was available for a teleconsultation. A respiratory physician was also available. Scheduled and ad hoc appointments were conducted. Thirty-five patients were on home mechanical ventilation, 13 with invasive and 22 with non-invasive devices. The main diagnosis was chronic obstructive pulmonary disease (COPD). The follow-up period was 176 days (SD 69). In all, 376 calls for scheduled consultations were received and 83 ad hoc consultations were requested by the patients. The actions taken were: 55 therapy modifications, 19 hospitalizations in a respiratory department for decompensated CRF, three hospitalizations in an intensive care unit (ICU), 22 requests for further investigations, 25 contacts with the general practitioner (GP), 66 demands for respiratory consultations and 10 calls for the emergency department. The mean time recorded for the 459 calls was 16 min/patient/week. In 82% of calls, a pSat recording was received successfully. The nurse time required to train the users in the operation of the pSat instrument was high (mean time 30 min). However, the results showed that home monitoring was feasible, and useful for titration of oxygen, mechanical ventilation setting and stabilization of relapses.

Chronic Disease↗
PubMed2006

[Health care and infective aspects in patients affected by common variable immunodeficiency assisted in the Lazio Regional Authority Reference Centre for Primary Immunodeficiencies].

Common variable immunodeficiency (CVID) is a chronic condition characterised by a predominant defect of humoral immunity. In most cases the diagnosis of CVID is made during adulthood; the main clinical features of CVID are chronic and relapsing infections (mainly of respiratory and gastroenteric tracts). CVID patients may also develop neoplastic and autoimmune diseases. In our centre (the Regional Centre for Primary Immunodeficiencies of the Lazio Regional Authority) we administered a 23-item questionnaire to 60 patients with CVID undergoing substitutive therapy with intravenous immunoglobulins (IVIG) about their demographic characteristics, time of clinical onset, time of diagnosis of CVID, clinical features, IVIG doses and administration intervals, and self-assessment of health status. In addition, the clinical history of all patients was reviewed, and the levels of serum IgG, IgA and IgM were evaluated and compared with the pre-therapy serum concentration. Moreover, an analysis of the treatment costs was performed. At onset, 67.2% of patients presented recurrent respiratory infections, and 50% had infections of the lower respiratory tract; 39.6% of the patients had gastroenteric infections. Most patients (57%) had recurrent infections of at least 2 of the respiratory, gastroenteric and/or urogenital tracts. In 37.9% of the group the diagnosis of CVID was made in less than 2 years after the beginning of symptoms, but in many cases (22.4%) the diagnosis took more than 10 years. 93% of patients are treated with a dose of IVIG between 6 and 15 g per administration, with intervals between 2 and 3 weeks. The review of patients'clinical history showed that 43% of patients have had respiratory infections during the follow-up in our Centre, 43% have splenomegaly (3% were also subjected to splenectomy) and 18.3% have autoimmune diseases. The mean concentration of IgG before the beginning of IVIG therapy was 235 mg/dl, while during the follow-up it was 664 mg/dl. Given the long time often required for diagnosis, general physicians and specialists should be better informed in order to make diagnosis swifter. The substitutive therapy with IVIG is effective in preventing recurrent infections and complications. A thorough follow-up is important for diagnosing neoplastic and autoimmune complications; in addition, immunologic analysis of peripheral blood and bone marrow are useful in identifying subgroups of patients with more severe clinical features. Finally, in selected patients, treatment costs may be controlled by modifying the dosage of IVIG or the intervals between administrations.

Adolescent↗
PubMed2005

Aggregata andresi n. sp. (Apicomplexa: Aggregatidae) from the ommastrephid squid Martialia hyadesi in the SW Atlantic Ocean and some general remarks on Aggregata spp. in cephalopod hosts.

A new species of coccidian, Aggregata andresi, is described from the digestive tract of the flying squid Martialia hyadesi, an ommastrephid squid that lives in cold subantarctic waters in the Southwest Atlantic. Gamogonic and sporogonic stages were observed in the digestive tract of 96.5% studied hosts. Oocysts were ovoid to subspheroid in shape, 170-590 microm in length and 200-530 microm in width. Each oocyst contained approximately 45,000 sporocysts. Sporocysts measured 9.5-10 microm in length and 8-8.5 microm in width. The surface of the sporocyst wall was smooth and the cyst wall thick. Each sporocyst contained three sporozoites measuring 16-20 microm in length and 2-2.5 microm width. A. andresi is the second species of Aggregata to be reported from a nerito-oceanic cephalopod host.

Animals↗
PubMed2005

Women dermatologists and the Spanish Academy of Dermatology and Venereology (SADV).

BASIS: The Spanish Academy of Dermatology and Venereology (SADV) consists of a large majority of Spanish dermatologists. Their track record and history can be considered as parallel to that of female dermatologists. The aim of this study is to determine the role of women in the SADV throughout its history, both in terms of their involvement and their positions of responsibility. MATERIALS AND METHODS: To obtain data, we consulted the SADV archives from the year of its foundation until 2001. We also consulted other Spanish medical societies, receiving responses from three of them. RESULTS: Until 1964, no woman had ever become a member of the SADV. Since then, the percentage began to increase slowly (5.5% in 1975). Over the last decade, their involvement has increased rapidly, reaching 41.34% in 2001. During this time, only 11 women have held positions on the Board of Directors, and in all cases in nonpresidential positions. The percentage of women in paediatrics, ophthalmology and pathologic anatomy is similar. CONCLUSIONS: During this time, the number of female dermatologists in the SADV has gradually increased. This increase is, nonetheless, not uniform, with the greatest growth being seen during the last decade. Women in positions of responsibility have been scarce and, to date, there has been no female national president. These results coincide with statistics revealed in other areas of the medical society.

Academies and Institutes↗
PubMed2005

Role of intestinal bacterial overgrowth and intestinal motility in bacterial translocation in experimental cirrhosis.

BACKGROUND: Intestinal bacterial overgrowth (IBO) is related to small bowel motility and has been involved in the pathogenesis of bacterial translocation (BT) in experimental models, and both overgrowing gut flora and translocating bacteria to mesenteric lymph nodes are common features in cirrhosis. OBJECTIVES: The aims of this study were to analyze cecal aerobic bacteria and intestinal transit in cirrhotic rats, and their relationship with BT, evaluating the role of intestinal bacterial overgrowth and small bowel dismotility in the development of BT in experimental cirrhosis. MATERIAL AND METHODS: We included twenty-seven male Sprague-Dawley rats with carbon tetrachloride-induced cirrhosis without ascites and ten controls. Cultures of mesenteric lymph nodes (MLN), peripheral and portal blood, liver, spleen and cecal samples were carried out. Small intestinal transit was determined in ten cirrhotic rats and in ten control rats. RESULTS: The prevalence of bacterial translocation was 56%. Total cecal aerobic bacteria count was significantly higher in cirrhotic rats than in control rats (p < 0.001). Cirrhotic rats with translocated bacteria had higher total aerobic intestinal counts than culture-negative MLN bacteria (p < 0.05). The prevalence of total intestinal bacterial overgrowth in cirrhotic animals was 67%, and 0% in control animals (p < 0.001). According to BT, total IBO was more frequent in cirrhotic rats with BT versus those without BT (93 vs. 33%) (p < 0.001). Of the translocating bacteria, 95.6% were found to be overgrown in the cecum. The small-intestinal transit was slower in cirrhotic rats (60.5 +/- 12.7 cm vs. 81.2 +/- 5.7 cm) than in control animals (p < 0.001). CONCLUSIONS: These results suggest that the increase of intestinal aerobic bacteria in experimental cirrhosis is associated with translocation. In addition, IBO is frequent in cirrhotic rats, and is supposed to play an important role in the development of BT. Impaired motility of the small intestine is a common feature in cirrhosis and may be implicated in the pathogenesis of IBO.

Analysis of Variance↗
PubMed2002

Scratching the sporocyst surface: characterisation of European Aggregata species by atomic force microscopy.

The application of atomic force microscopy to the understanding of surface structure and atomic-scale measurements on the sporocyst of European Aggregata species, intracellular coccidia of the cephalopods Octopus vulgaris and Sepia officinalis, is presented here. Using the roughness mean surface (RMS) as an index, we reveal texture to be a key parameter for characterisation of the sporocyst surface properties, which resolve the historical synonymy within the European Aggregatidae. Roughness measurements from RMS algorithms may also be an important diagnostic taxonomic character for the differentiation of Aggregata species in the future.

Algorithms↗
PubMed2002

Extensive population subdivision of the cuttlefish Sepia officinalis (Mollusca: Cephalopoda) around the Iberian Peninsula indicated by microsatellite DNA variation.

The Atlantic Ocean-Mediterranean Sea junction has been proposed as an important phylogeographical area on the basis of concordance in genetic patterns observed at allozyme, mtDNA and microsatellite DNA markers in several marine species. This study presents microsatellite DNA data for a mobile invertebrate species in this area, the cuttlefish Sepia officinalis, allowing comparison of this relatively new class of DNA marker with previous allozyme results, and examination of the relative effects on gene flow of the Strait of Gibraltar and the Almería-Oran oceanographic front. Genetic variation at seven microsatellite loci screened in six samples from NE Atlantic and Mediterranean coasts of the Iberian Peninsula was high (mean Na = 9.6, mean H(e) = 0.725). Microsatellites detected highly significant subpopulation structuring (F(ST)= 0.061; R(ST) = 0.104), consistent with an isolation-by-distance model of low levels of gene flow. Distinct and significant clinal changes in allele frequencies between Atlantic and Mediterranean samples found at five out of seven loci, however indicate these results might be also consistent with an alternative model of secondary contact and introgression between previously isolated and divergent populations, as previously proposed for other marine species from the Atlantic-Mediterranean area. A pronounced 'step' change between SW Mediterranean samples associated with the Almería-Oran front suggests this oceanographic feature may represent a contemporary barrier to gene flow.

Animals↗
PubMed2002

Polarized angular dependent spectroscopy of epithelial cells and epithelial cell nuclei to determine the size scale of scattering structures.

An understanding of the relationship between tissue structures and light scattering from tissue will help facilitate the development and acceptance of noninvasive optical diagnostics including elastic scattering spectroscopy, diffuse reflectance, and optical coherence tomography. For example, a quantitative model of the structures that scatter light in epithelial cells would allow determination of what structures control the characteristics of in vivo light transport measurements and subsequently could provide a detailed relationship between cellular structures and optical measurements. We have determined the size distribution of refractive index structure variations in epithelial cells as well as in nuclei isolated from epithelial cells from measurements of the angular dependence of polarized light scattering. The quantitative size distributions we obtained for both whole cells and isolated nuclei include particles with effective radii of 2 microm to 10 nm or less and contain orders of magnitude more small particles than large particles. These results demonstrate that not only are biological cells very heterogeneous, but so are the nuclei within them. Light scattering is likely sensitive to structures smaller than those commonly investigated by standard pathology methods.

Animals↗
PubMed2002

Malaria vectors in Bioko Island (Equatorial Guinea): PCR determination of the members of Anopheles gambiae Giles complex (Diptera: Culicidae) and pyrethroid knockdown resistance (kdr) in An. gambiae sensu stricto.

Anopheles gambiae sensu lato Giles, 1902 and Anophelesfunestus Giles, 1900 are the main malaria vectors on the island of Bioko (Equatorial Guinea). This study was carried out to determine: a) members of the An. gambiae complex that may be present on the island of Bioko and, b) the sensitivity of An. gambiae sensu stricto to pyrethroids. The analysis by PCR detected the presence of An. gambiae s.s. as the major vector of the complex and the "forest chromosomal form" was demonstrated by cytogenetic analysis. The presence of Anopheles melas in the southwest, north and southeast of the island justifies its study as a vector. The molecular characterization of pyrethroid knockdown resistance (kdr) showed that the populations of An. gambiae s.s. were sensitive and no mutations were found. This fact justifies the implementation on a large scale of pyrethroid-impregnated bednets within the framework of the Malaria Control Program of Equatorial Guinea.

Animals↗
PubMed2002

Effects of microgravity and hypergravity on early development stages of Xeonopus laevis.

The aim of this work is to evaluate the development of X.l. in modified gravity conditions. The simulation of hyper and microgravity was performed utilizing: an hyperfuge, a Clinostat and later on a Random Positioning Machine (RPM, 3d Clinostat). The effect of hypergravity on embryos is significantly higher than that of microgravity; the exposure of embryos to 3xg for 3 days before and after hatch causes an activation of HSP-60 and HSP-70. Embryos exposed to 3xg during the first 3 days of development are very sensitive and show a retard of development, with a lower content of DNA, neutral glycolipids and gangliosides compared to controls.

Journal Article↗
PubMed2001

Molecular weight distribution and structural characteristics of polymers obtained from acid soluble lignin treated by oxidative enzymes.

Brown precipitates were obtained by polymerization of low molecular weight lignin fragments contained in a model effluent. Polymerization reactions were initiated by potato-polyphenoloxidase (PPO) or horseradish peroxidase/H(2)O(2) system (HRP/H(2)O(2)). The insolubilization processes occurred after a molecular weight increase of the lignin, as shown by gel permeation chromatography (GPC). The effect of reaction time, pH and amount of soluble lignin per unit of enzyme activity on the molecular weight distribution was evaluated for PPO-initiated reactions. For HRP-initiated system the amount of H(2)O(2) per unit of enzyme activity was also evaluated. Chemical characterization of the macromolecules obtained under optimized conditions and the soluble lignin fragments present in the effluent suggests that the polymerization reactions occur by oxidative cleavage of alpha-beta unsaturated bonds of the soluble lignin fragments. Methoxyl group analysis showed that p-hydroxycoumaryl units were preferentially oxidized by PPO. In contrast, HRP oxidized preferentially guaiacyl and siringyl units giving more condensed polymers.

Journal Article↗
PubMed2001

Leukocyte activation, erythrocyte damage, lipid profile and oxidative stress imposed by high competition physical exercise in adolescents.

BACKGROUND: The aim of this study was to evaluate and to compare the lipid profile and the levels of leukocyte activation, red blood cell (RBC) damage and of oxidative stress in two groups of adolescents, with similar body mass index: high competition swimmers and adolescents practising moderate regular physical exercise. METHODS: As markers of leukocyte activation, we measured plasma lactoferrin, elastase and granulocyte-monocyte colony stimulating factor. We studied RBC membrane band 3 profile and membrane-bound hemoglobin, as markers of RBC damage and aging; total and differential leukocyte count and RBC count, hematocrit, hemoglobin concentration and hematimetric indexes were also measured. Lipid profile included the evaluation of triglycerides (TG), total cholesterol (Chol), high-density lipoprotein cholesterol (HDLc), low-density lipoprotein cholesterol (LDLc), apolipoproteins AI and B (Apo AI and B), and lipoprotein (a) (Lp(a)). To evaluate oxidative stress, lipoperoxidation products and total antioxidant capacity were measured. RESULTS: We found that high competition adolescents presented increased plasma levels of leukocyte activation products, increased RBC damage suggesting aging and premature removal, and higher oxidative stress. Lipid profile showed some risk and some protective changes. CONCLUSIONS: Our data suggest that high competition exercise, by imposing a higher and sustained oxidative and proteolytic stress, may contribute in the future to a higher risk of cardiovascular disease. We believe these findings warrant a reevaluation of current views in the intensity, duration and regularity of physical exercise, and that the evaluation of leukocyte activation products, RBC damage, oxidative stress and lipid profile may represent good markers to establish putative protective thresholds.

Adolescent↗
PubMed2001

A review of reproductive strategies in cephalopods.

Cephalopod reproductive strategies are reviewed in order to clarify their current, confusing status. Based on the type of ovulation, spawning pattern and growth between egg batches or spawning periods, five comprehensive and flexible cephalopod reproductive strategies are defined. Accordingly, with these three factors the following classification is proposed. (a) Spawning once (formerly semelparity) consisting of simultaneous terminal spawning, with synchronous ovulation, monocyclic spawning and absence of growth between egg batches. (b) Spawning more than once (formerly iteroparity) including: (i) polycyclic spawning with egg-laying occurring in separate batches during the spawning season and growth occurring between production of egg batches and spawning seasons; (ii) multiple spawning, with group-synchronous ovulation, monocyclic spawning and growth between egg batches; (iii) intermittent terminal spawning, with group-synchronous ovulation, monocyclic spawning and no growth between egg batches; (iv) continuous spawning, with asynchronous ovulation, monocyclic spawning and growth between egg batches. Examples of species exhibiting each of these reproductive strategies are given. The large amount of inter-species variation in several life-history traits related to reproductive events is discussed.

Animals↗