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Biomedical subjects

G Espinosa

Publications and source records attributed to G Espinosa.

At least 37 records · Page 2Linked to original sources
PubMed2002

Myelodysplastic and myeloproliferative syndromes associated with giant cell arteritis and polymyalgia rheumatica: a coincidental coexistence or a causal relationship?

A variety of systemic autoimmune disorders have been reported in patients with myelodysplastic and myeloproliferative syndromes. A possible association with polymyalgia rheumatica and giant cell arteritis has also been recognised. We report another case of polymyalgia rheumatica and one of giant cell arteritis associated with a myelodysplastic syndrome and the two first cases of giant cell arteritis associated with essential thrombocytaemia and chronic myelomonocytic leukaemia, respectively. It seems that there is a relationship between these entities, but the nature of this association is still unknown.

Aged↗
PubMed2002

Neutron angular distribution in a plasma focus obtained using nuclear track detectors.

The dense plasma focus (DPF) is a coaxial plasma gun in which a high-density, high-temperature plasma is obtained in a focused column for a few nanoseconds. When the filling gas is deuterium, neutrons can be obtained from fusion reactions. These are partially due to a beam of deuterons which are accelerated against the background hot plasma by large electric fields originating from plasma instabilities. Due to a beam-target effect, the angular distribution of the neutron emission is anisotropic, peaked in the forward direction along the axis of the gun. The purpose of this work is to illustrate the use of CR-39 nuclear track detectors as a diagnostic tool in the determination of the time-integrated neutron angular distribution. For the case studied in this work, neutron emission is found to have a 70% contribution from isotropic radiation and a 30% contribution from anisotropic radiation.

Copper↗
PubMed2002

Measurements of alpha particle energy using nuclear tracks in solids methodology.

In this paper we present a method for the measurement of alpha particle energy using polycarbonate materials as nuclear track detectors (NTDs). This method is based on the interaction of the radiation with the solid-state materials, using the relationship between the energy deposited in the material by the ionising particle and the track developed after an established chemical process. The determination of the geometrical parameters of the formed track, such as major axis, minor axis and overall track length, permit determination of the energy of the alpha particle. The track analysis is performed automatically using a digital image system, and the data are processed in a PC with commercial software. In this experiment 148Gd, 238U, 230Th, 239Pu and 244Cm alpha particle emitters were used. The values for alpha particle energy resolution, the linear response to energy, the confidence in the results and the automatisation of the procedure make this method a promising analysis system.

Alpha Particles↗
PubMed2002

Nuclear tracks in CR-39 produced by carbon, oxygen, aluminium and titanium ions.

This work describes the response of CR-39 (allyl diglycol polycarbonate) to different ions (C, O, Al and Ti) produced by the Instituto de Fisica 3 MV 9SDH-2 Pelletron accelerator and backscattered from a thin Au film on a C support. The ion energies were chosen in series such that the ranges of the different ions in the detector were 2, 3, 4, 5, 6, 7 and 8 microm respectively for each series. Once exposed, the detectors were etched with a solution of 6.25 M KOH at 60 degrees C, and the reading was carried out using a digital image analysis system. An analysis of the measured track diameters of all the types of ions indicates that, for a given range, track kinetics are independent of type of ion, energy and stopping power.

Aluminum↗
PubMed2002

Analysis of the formed track in solid state materials using atomic force microscopy.

The track formation in solid state materials, from the theoretical point of view, is still under study. One way to understand the track formation mechanisms and radiation damage of the charged particles in some materials such as polymers, glasses and minerals, is to analyse the surface topography effects. In this work, the track formation analysis in polycarbonate material is presented using an atomic force microscope (AFM) to characterise the evolution of the track on the material surface and beyond a thin layer of the surface material. The AFM is very useful to obtain valuable information at the level of the atomic structure of the materials and of the nuclear tracks, due to its high resolution and very easy operation involving also a simple sample preparation. The results show the development of the formed track by means of induced surface effects after being exposed to ionising radiation and chemical etching.

Microscopy, Atomic Force↗
PubMed2002

The lung in the antiphospholipid syndrome.

Patients with antiphospholipid syndrome (APS) may develop a broad spectrum of pulmonary disease. Pulmonary thromboembolism and pulmonary hypertension are the most common complications, but microvascular pulmonary thrombosis, pulmonary capillaritis, and alveolar haemorrhage have also been reported. Clinicians should seriously consider these types of vascular injury when evaluating patients with APS who present with dyspnoea, fever, and infiltrates on chest radiography.

Antiphospholipid Syndrome↗
PubMed2002

Clinical significance of acquired activated protein C resistance in patients with systemic lupus erythematosus.

Antiphospholipid antibodies (aPL) may induce acquired activated protein C resistance (acquired APCR). The role of acquired APCR in patients with systemic lupus erythematosus (SLE) is not well known. To evaluate the prevalence of acquired APCR and its association with clinical manifestations we studied 103 consecutive SLE patients and 103 matched controls. APCR in the undiluted test and after dilution in factor V deficient plasma, factor V Leiden, protein C and S, lupus anticoagulant, and anti-cardiolipin, anti-beta2-glycoprotein I and anti-prothrombin antibodies were determined. Factor V Leiden was found in 4% in both patients and controls. The prevalence of acquired APCR was 22% for the undiluted assay and 17% in the diluted test. In SLE patients, acquired APCR was associated with aPL (39 vs 13% in undiluted assay, P = 0.007; and 33 vs 7% in the diluted test, P = 0.001). Arterial thromboses were found in 24% of patients with acquired APCR and in 6% of patients without (P = 0.04). However, no relationship was found with venous thrombosis. Acquired APCR was also associated with pregnancy losses: miscarriages in 70% of women with acquired APCR vs 32% in those without (P=0.03). Thus, in SLE patients acquired APCR seems to be associated with increased prevalence of arterial thrombosis and pregnancy losses.

Abortion, Spontaneous↗
PubMed2002

Lessons from the "Euro-Lupus Cohort".

The "Euro-Lupus Cohort" is composed by 1,000 patients with systemic lupus erythematosus (SLE) that have been followed prospectively since 1991. These patients have been gathered by a European consortium - the "Euro-Lupus Project Group". This consortium was originated as part of the network promoted by the "European Working Party on SLE", a working group created in 1990 in order to promote research in Europe on the different problems related to this disease. The "Euro-Lupus Cohort" provides an updated information on the SLE morbidity and mortality characteristics in the present decade as well as defines several clinical and immunological prognostic factors.

Adolescent↗
PubMed2001

[Liquid ecstasy poisoning: study of 22 cases].

BACKGROUND: To describe characteristics of acute poisoning with liquid ecstasy (gammahydroxybutyrate, GHB). PATIENTS AND METHOD: Epidemiological and clinical data of patients with acute GHB poisoning seen at emergency department (ED) along one year were collected. RESULTS: 22 patients were included. Typical profile corresponds to a young male, who consults on weekend, at night, complaining of a marked decreased level of consciousness. Patients refer coingestion of other drugs and typically regain consciousness spontaneously in a short time. CONCLUSION: The frequency of GHB poisoning has increased notably in our environment. GHB poisoning must be considered on the differential diagnostic of coma of unknown origin in young patients attended in ED.

Adolescent↗
PubMed2001

[Impact in the quality of health care and cost-effectiveness analysis of the reform of an emergency medicine service].

BACKGROUND: To determine the effects that the reform of an emergency department (ED) have on efficacy, health care quality and efficiency. MATERIAL AND METHOD: Reforms consisted of 50% and 34% increases in structural and human resources, respectively. Roles of each ED member were redetermined, new assistance pathways were implemented, and the relationship between ED and the remaining hospital departments was reassessed. As efficacy markers, we determined the number of patients waiting to be attended (Pesp), the waiting time of patients to receive medical assistance (T(esp)),and the total waiting time of patients staying in the ED (T(total)). As health-care quality markers, we determined the percentage of patients leaving ED without having been visited by a physician(IPNV), the percentage of patients who were visited again (IPR),and the percentage of mortality (IPF). We also quantified the number of visits to the ED. All these data were obtained daily over 3 weeks, before (February 1999) and after (February 2000)the reforms. Effectiveness was estimated from the ratio P(total)/T(esp)(E1) and P(total)/P(esp) (E2). Costs were recorded for both periods and a cost-effectiveness analysis was performed to study the efficiency. RESULTS: In 2000, the number of visits increased by +12% (CI 95%: 2% to 22%). Despite this increase, we observed an improvement of most efficacy and health-care quality markers after the ED reforms. E1 increased by 996% (CI 95%: 335% to 1,658%) and E2 increased by 186% (CI 95%: -23%to 395%). Cost-effectiveness analysis showed 70% (CI 95%: 33%to 107%) and 56% (CI 95%: 18% to 94%) increases regarding E1 and E2, respectively, after the reforms. CONCLUSIONS: Providing ED with the necessary resources leads to an objective improvement of its efficacy and health-care quality and, consequently, the service and quality perceived by users improve. Despite the total cost increase after the ED reforms, efficiency also improves.

Cost-Benefit Analysis↗
PubMed2001

Antiphospholipid antibodies and thrombophilic factors in giant cell arteritis.

OBJECTIVES: To evaluate the prevalence of thrombophilic risk factors known to induce intravascular clotting and to assess their relationship with ischemic manifestations in giant cell arteritis (GCA). METHODS: Eighty consecutive patients with established GCA were included: 36 with isolated temporal arteritis (TA), 14 with isolated polymyalgia rheumatica (PMR), and 30 with TA and PMR. Forty-four patients (67%) had ischemic phenomena due to GCA. Twelve patients (15%) had thrombotic events unrelated to GCA (6 strokes, 5 deep venous thrombosis, and 1 myocardial infarction). A control group of 100 age- and sex-matched individuals without autoimmune disease, bleeding disorders, thrombosis, or clinical picture of TA or PMR also was analyzed. All participants were tested for the antiphospholipid antibody (aPL) profile, protein C, protein S, antithrombin activity, factor V Leiden mutation, and prothrombin gene G20210A mutation. We also studied fibrinolysis parameters: plasminogen, tissue-type plasminogen activator (t-PA) antigen, t-PA activity, type-1 plasminogen activator inhibitor (PAI-1) antigen, PAI-1 activity, and the 4G/5G polymorphism of the promoter region of the PAI-1 gene. RESULTS: Eleven patients (18%) tested positive for lupus anticoagulant, 24 (30%) for anticardiolipin antibodies, 9 (11%) for anti-beta 2-glycoprotein I antibodies, and 29 (36%) for antiprothrombin antibodies. No relationship was found between these autoantibodies and ischemic manifestations. None of the patients had decreased protein C, protein S or antithrombin activity. Two patients and 2 controls were heterozygous for factor V Leiden, and only 1 patient and 2 controls were heterozygous for the prothrombin gene G20210A mutation. No statistically significant correlation was found between any thrombophilic factor and GCA-related or GCA-unrelated ischemic events. CONCLUSION: GCA patients have a high prevalence of aPL that is not related to ischemic manifestations. Moreover, GCA-related or GCA-unrelated ischemic manifestations do not appear to be due to congenital thrombophilic risk factors. Semin Arthritis Rheum 31:12-20.

Aged↗
PubMed2001

Anticardiolipin antibodies are not a useful screening tool in a nonselected large group of patients with multiple sclerosis.

Recent works claiming that primary antiphospholipid syndrome (PAPS) cannot be clinically distinguished from multiple sclerosis (MS) recommend that MS patients be screened for anticardiolipin antibodies (ACA). In this study 296 randomly selected patients with MS and clinically isolated syndromes and 51 healthy controls were analyzed; ACA, anti-beta2-glycoprotein I, or antiprothrombin was found in 6 patients. No predominance of any kind of clinical manifestations and no cardinal manifestations of PAPS were found in these patients. ACA tests should be performed only when a suspicion of PAPS is raised and atypical clinical presentation for MS is found.

Adult↗
PubMed2000

The 4G/5G polymorphism of the type 1 plasminogen activator inhibitor gene and thrombosis in patients with antiphospholipid syndrome.

OBJECTIVE: To investigate the relationship between the 4G/5G polymorphism of the type 1 plasminogen activator inhibitor (PAI-1) gene and thrombotic manifestations in patients with antiphospholipid syndrome (APS). METHODS: We studied a total of 247 patients included in the following 4 groups: 70 patients with primary APS, 104 patients with systemic lupus erythematosus (40 with antiphospholipid antibodies [aPL] and clinical [secondary] APS, 13 with aPL but without clinical APS, and 51 with neither detectable aPL nor a history of thrombosis), 14 asymptomatic individuals with aPL, and 59 patients with thrombosis but without known thrombosis risk factors. A control group of 100 healthy individuals was also analyzed. PAI-1 4G/5G polymorphism was determined by polymerase chain reaction and endonuclease digestion. RESULTS: The allele frequency of 4G/5G in controls was 0.47/0.53. There were no differences in allele distribution among patient groups or between patients and controls. However, a higher frequency of the 4G allele was observed in APS patients with versus those without thrombosis (0.57 versus 0.39; P < 0.05) (odds ratio [OR] 2.83, 95% confidence interval [95% CI] 1.18-6.76). This higher frequency of the 4G allele was attributable to the higher frequency in patients with versus those without arterial thrombosis (0.64 versus 0.43; P < 0.01) (OR 5.96, 95% CI 1.67-21.32), while patients with venous thrombosis had an allele distribution similar to that of those without venous thrombosis (0.49 versus 0.50; P not significant). There was a trend toward higher PAI-1 antigen and activity levels in APS patients and controls with the 4G/4G genotype, but this did not reach statistical significance. CONCLUSION: The presence of the 4G allele of the 4G/5G polymorphism of the PAI-1 gene may be an additional risk factor for the development of arterial thrombosis in APS.

Adult↗