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Fernando Martínez

Publications and source records attributed to Fernando Martínez.

12 recordsLinked to original sources
PubMed2006

[Factors related to the risk of thrombosis in patients with lupus and antiphospholipid antibodies].

BACKGROUND AND OBJECTIVE: Antiphospholipid antibodies (aPL) are frequently associated with eritematosus systemic lupus (SLE) and increases the risk of thrombosis. The aim of the study was to analize risk factors of thrombosis and its temporal profile in subjects with SLE. PATIENTS AND METHOD: One hundred and two SLE patients -mean age: 37.5 years (range: 8-85); 90 women; mean of follow-up: 72 months (range: 9-324); 41 (40.2%) with aPL positive- were included in the study. Actuarial Kaplan-Meier curves were used to assess the thrombosis risk and Cox proportional hazard model was used to evaluate factors associated with the risk. RESULTS: 13 thrombotic events occurred in the group with aPL positive (mean of follow up: 83.5 months) and 5 events in aPL negative group (mean of follow up: 72 months). The event-rates were 3.93 and 0.96/100 patients/year for each group, respectively. Survival curves showed a significantly higher risk of thrombotic events in the patients with positive aPL as compared to the aPL negative group, and the risk still present throughout the observational time. Activated partial thromboplastine time up to 37 s was significantly associated with thrombosis risk (p = 0.003). Furthermore, positivity of lupus anticoagulant and proteinuria > 2.5 g/day tended to increase thrombotic risk, although they did not achieve statistical significance. CONCLUSIONS: In patients with SLE and aPL, risk of first thrombosis remains over the years, and a large activated partial thromboplastine time was the most important risk factor.

Adolescent↗
PubMed2006

Differential subcellular distribution of glucose transporters GLUT1-6 and GLUT9 in human cancer: ultrastructural localization of GLUT1 and GLUT5 in breast tumor tissues.

It has been proposed that the enhanced metabolic activity of tumor cells is accompanied by an increased expression of facilitative hexose transporters (GLUTs). However, a previous immunohistochemical analysis of GLUT1 expression in 154 malignant human neoplasms failed to detect the GLUT1 isoform in 87 tumors. We used 146 normal human tissues and 215 tumor samples to reassess GLUT1 expression. A similar number of samples were used to compare the expression of GLUT2-6 and 9. The classical expression of GLUT1-5 in different normal human tissues was confirmed, however, we were unable to detect GLUT2 in human pancreatic islet cells. GLUT6 was principally detected in testis germinal cells and GLUT9 was localized in kidney, liver, heart, and adrenal. In tumor samples, GLUT1, 2, and 5 were the main transporters detected. GLUT1 was the most widely expressed transporter, however, 42% of the samples had very low-to-negative expression levels. GLUT2 was detected in 31% of the samples, being mainly expressed in breast, colon, and liver carcinoma. GLUT5 was detected in 27% of breast and colon adenocarcinoma, liver carcinoma, lymphomas, and testis seminoma samples. In situ RT-PCR and ultrastructural immunohistochemistry confirmed GLUT5 expression in breast cancer. GLUT6 and 9 are not clearly over-expressed in human cancer. The extensive expression of GLUT2 and 5 (glucose/fructose and fructose transporters, respectively) in malignant human tissues indicates that fructose may be a good energy substrate in tumor cells. Our functional data obtained in vitro in different tumor cells support this hypothesis. Additionally, these results suggest that fructose uptake could be used for positron emission tomography imaging and, may possibly represent a novel target for the development of therapeutic agents in different human cancers.

Animals↗
PubMed2006

[Traumatic perforation of a duodenal diverticulum].

Duodenal diverticulum is a frequent abnormality that is usually diagnosed incidentally. Clinical manifestations usually mimic highly varied entities. Among the complications of duodenal diverticulum, perforation is fairly rare and rupture due to blunt trauma is even rarer. We describe the case of a male patient who presented a perforated duodenal diverticulum after an accidental fall.

Abdominal Injuries↗
PubMed2006

Road extraction from aerial images using a region competition algorithm.

In this paper, we present a user-guided method based on the region competition algorithm to extract roads, and therefore we also provide some clues concerning the placement of the points required by the algorithm. The initial points are analyzed in order to find out whether it is necessary to add more initial points, and this process will be based on image information. Not only is the algorithm able to obtain the road centerline, but it also recovers the road sides. An initial simple model is deformed by using region growing techniques to obtain a rough road approximation. This model will be refined by region competition. The result of this approach is that it delivers the simplest output vector information, fully recovering the road details as they are on the image, without performing any kind of symbolization. Therefore, we tried to refine a general road model by using a reliable method to detect transitions between regions. This method is proposed in order to obtain information for feeding large-scale Geographic Information System.

Algorithms↗
PubMed2006

Perioperative intravenous iron, with or without erythropoietin, plus restrictive transfusion protocol reduce the need for allogeneic blood after knee replacement surgery.

BACKGROUND: Unilateral total knee replacement (TKR) results in a substantial blood loss and 30 to 50 percent of patients receive allogeneic blood transfusion (ABT). Therefore, the effectiveness of a restrictive transfusion trigger (hemoglobin [Hb] level < 8 g/dL) plus stimulation of erythropoiesis was evaluated, with or without blood salvage, for reducing ABT in TKR patients. STUDY DESIGN AND METHODS: A series of 139 consecutive of primary TKR patients received perioperative iron sucrose (2 x 200 mg/48 hr, intravenously [IV]), plus preoperative erythropoietin (EPO; 1 x 40.000 UI, sc) if preoperative Hb level was less than 130 g per L (Group A). This protocol was applied to another series of 173 consecutive TKR patients who also received postoperative unwashed shed blood (USB) if preoperative Hb level was less than 130 g per L (Group B). Perioperative clinical and laboratory data were gathered. RESULTS: No adverse effects of iron sucrose, EPO, or USB administration were witnessed, and only 13 patients received ABT overall (4%). No major differences in perioperative blood counts or iron metabolism variables were observed between groups, but stimulation of erythropoiesis seemed to be more pronounced in those patients receiving EPO (p < 0.05). There were no differences in postoperative complications between groups, but length of hospital stay for patients with a preoperative Hb level of less than 130 g per L was shorter in Group B (p < 0.05). CONCLUSION: This blood saving protocol seems to be effective for reducing ABT in TKR patients. Which patients are more likely to benefit from either perioperative iron administration or selective addition of postoperative blood salvage to pharmacologic treatment, however, needs to be further evaluated.

Aged↗
PubMed2005

Management of infants with chronic lung disease of prematurity in Chile.

Despite advances in the prevention and management of respiratory distress syndrome, chronic lung disease of prematurity (CLD) remains a major cause of morbidity and mortality in preterm babies in Chile. Its incidence varies from 10% to 60% in different regions of Chile. Since 1998, the management of CLD after discharge from neonatal unit follows national guidelines. Target oxygen saturation is 85% to 91% in the first 1 week of life, 91% to 94% from 1 to 2 weeks and over 95% after 44 weeks postconceptional age. National home oxygen program has improved outcome in infants with CLD. Other specific treatments are used with caution. Diuretics are used for pulmonary oedema. The adverse neurological outcome in infants treated with postnatal steroids restricts its use to infants who cannot be weaned from mechanical ventilation. Inhaled steroids and bronchodilators may reduce asthma-like symptoms in established CLD. Prevention of RSV infection in CLD babies is paramount. The preterm infant population has been maintained under surveillance nationally since 1998.

Adrenal Cortex Hormones↗
PubMed2005

Molecular taxonomic study of Chagas disease vectors from the phyllosoma, lecticularia, and rubrofasciata complexes.

The Triatiominae (Hemiptera: Reduviidae) are hematophagous hemipters of importance because they transmit Trypanosoma cruzi, the causal agent of Chagas disease. The aim of this study was to define the possible relationships between species of the Phyllosoma complex (Triatoma mazzottii, Triatoma pallidipennis, and Triatoma longipennis) and species of other complexes present in Mexico that have not been previously analyzed (Triatoma lecticularia and Triatoma rubida). In addition, it was determined the inclusion of Triatoma bassolsae in the Phyllosoma complex by using 10 isoenzymatic systems (corresponding to the 14 loci). Results of isoenzymatic study show that between the species of the Phyllosoma complex including Triatoma bassolsae, the polymorphism of the analyzed enzymes ranges from 14% to 50% (P < or = 0.95) and the species from external complexes showed polymorphism values of 43% (Triatoma lecticularia), 43% (Triatoma rubida), and 36% (Triatoma infestans). The genetic tree shows a clear difference between species of the Phyllosoma complex and the other complexes.

Animals↗
PubMed2003

Retroperitoneal mucinous cystadenoma.

INTRODUCTION: Retroperitoneal mucinous cystadenomas are rare tumors. Only 25 cases have been reported in the English literature until 2002. The histogenesis is unclear, diagnosis is never made preoperatively and surgery is the only treatment. CASE REPORT: We report an additional case.

Adult↗
PubMed2002

Extractable soil heavy metals following the cessation of biosolids application to agricultural soil.

Changes in soil heavy metal extractability following the cessation of biosolids applications were studied in a long-term field experiment. Two anaerobically digested biosolids from wastewater treatment plants in Madrid (Sur and Viveros) were applied to cropland from 1983 to 1990. Soil samples were collected in the 1st, 5th and 9th year after the last biosolids application. Soil pH did not vary significantly after biosolids applications. Organic matter and total heavy metals (Zn, Pb, Cd, Ni, Cr and Cu) concentrations initially increased but then declined over time, mostly after the first 5 years following biosolids application. Metal extracted with DPTA increased in Sur treatments during the 1st year and diminished thereafter. However, in Viveros treatments, heavy metals extracted increased during the 1st year, declined in 1995, and showed a slight increase in 1999. These changes in heavy metal extractability were widely observed in the percentage of extractable metal recovery (EMR). The differences observed in the pattern of the two sources of biosolids applied could be due to the different rates of decomposition of their organic matter.

Agriculture↗
PubMedDate not supplied

Vitamin C uptake and recycling among normal and tumor cells from the central nervous system.

Specialized cells transport vitamin C in its reduced form using sodium-dependent cotransporters (SVCT1 and SVCT2). Additionally, different cells transport the oxidized form of vitamin C, dehydroascorbic acid, through glucose transporters (GLUTs). We have proposed recently a model for vitamin C uptake that resolves the apparent contradiction that although only ascorbic acid is detectable in vivo, there are cells that transport only dehydroascorbic acid. We carried out a detailed kinetic analysis to compare the mechanisms of vitamin C uptake in normal human melanocytes, neurons isolated from brain cortex, hypothalamic ependymal-glial cells, and astrocytes. Uptake of ascorbic acid was also analyzed in the human oligodendroglioma cell line TC620, in human choroid plexus papilloma cells (HCPPC-1), and in the neuroblastoma cell line Neuro-2a. Melanocytes were used to carry out a detailed analysis of vitamin C uptake. Analysis of the transport data by the Lineweaver-Burk plot revealed the presence of one functional component (K(m) 20 microM) involved in ascorbic acid transport by melanocytes. Vitamin C sodium-dependent saturable uptake was also observed in neurons and hypothalamic tanycytes. We confirmed SVCT2 expression in neurons by in situ hybridization; however, SVCT2 expression was not detected in astrocytes in situ. Functional data indicate that astrocytes transport mainly dehydroascorbic acid, using the glucose transporter GLUT1. Our functional uptake analyses support the hypothesis that astrocytes are involved in vitamin C recycling in the nervous system. This recycling model may work as an efficient system for the salvage of vitamin C by avoiding the hydrolysis of dehydroascorbic acid produced by antioxidative protection.

Animals↗