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M Boronat

Publications and source records attributed to M Boronat.

At least 19 recordsLinked to original sources
PubMed2006

Diabetes mellitus and impaired glucose regulation in the Canary Islands (Spain): prevalence and associated factors in the adult population of Telde, Gran Canaria.

AIMS: To estimate the prevalence and the determinants of diabetes mellitus and impaired glucose regulation (IGR) in an adult Canarian population. METHODS: Cross-sectional study. One thousand and thirty subjects aged 30-82 years were randomly selected. Participants completed a survey questionnaire and underwent blood pressure measurements, anthropometry, blood samples, and a 75-g standardized oral glucose tolerance test. RESULTS: The age-standardized prevalence of diabetes was 15.8% (95% confidence interval: 11.8-19.8) in men and 10.6% (7.1-14.1) in women. Total prevalence was 13.2% (11.1-15.2). Among individuals with diabetes, 55.4% of men and 38.2% of women were not previously diagnosed. The age-standardized prevalences of impaired glucose tolerance and impaired fasting glycaemia were 11.4% (9.5-13.4) and 2.8% (1.8-3.8), respectively. In multivariate analyses, age, waist circumference, serum triglycerides, and familial history of diabetes were independently associated with diabetes in both sexes, while a value of C-reactive protein (CRP) >/= 1 mg/l showed an association with diabetes, but only in men. Age and triglycerides were related to impaired glucose regulation (IGR) in both sexes, waist circumference was related to IGR exclusively in men, and familial diabetes exclusively in women. Statistically significant interactions between gender and both CRP and triglycerides were found with respect to diabetes, and between gender and both waist circumference and triglycerides for IGR. CONCLUSIONS: Compared with the rest of Spain, the prevalence of diabetes is moderately increased in this area of the Canary Islands. Along with other well-established risk factors, CRP was independently associated with diabetes, but only in the male population.

Adult↗
PubMed2005

Candida glabrata fungemia cured by antibiotic-lock therapy: case report and short review.

Catheter removal is now the standard recommendation of catheter-related fungemia even when tunneled devices are used. However, in the clinical practice, this procedure is not always without risks. Antibiotic-lock technique can resolve many cases of catheter-related bacteraemia, but cure of catheter-related candidemia by this method has been attempted in very few instances, reviewed in this article. Herein, we report a case of non-complicated Candida glabrata fungemia related to a Hickman catheter used for parenteral nutrition, cured with intraluminal amphotericin B in addition to systemic therapy. This case demonstrates that 'antifungal-lock therapy' can be effectively used in selected cases of catheter-related candidemia.

Adult↗
PubMed2005

Prevalence of the metabolic syndrome in the island of Gran Canaria: comparison of three major diagnostic proposals.

AIMS: The present study was conducted to estimate the prevalence of the metabolic syndrome in a Canarian population, and to compare its frequency as defined by the most commonly used working definitions. METHODS: Cross-sectional population-based study. One thousand and thirty adult subjects were randomly selected from the local census of Telde, a city located on the island of Gran Canaria. Participants completed a survey questionnaire and underwent physical examination, fasting blood analyses, and a 75-g standardized oral glucose tolerance test. The prevalence of the metabolic syndrome was estimated according to the definitions proposed by the World Health Organization (WHO), the European Group for the Study of Insulin Resistance (EGIR) and the National Cholesterol Education Program (NCEP), the latter with the original (6.1 mmol/l) and the revised criterion (5.6 mmol/l) for abnormal fasting glucose. RESULTS: The adjusted prevalence of the metabolic syndrome was 28.0, 15.9, 23.0 and 28.2%, using the WHO, EGIR, NCEP and revised NCEP criteria, respectively. The measure of agreement (kappa statistic) was 0.57 between the WHO and the original NCEP definitions, and 0.61 between the WHO and the revised NCEP definitions. After excluding diabetic subjects, the agreement between the EGIR and WHO proposals was fairly good (kappa=0.70), whereas concordance of the EGIR with the original and the revised NCEP definitions was moderate (kappa=0.47 and 0.46, respectively). CONCLUSIONS: Whichever the considered diagnostic criteria, the prevalence of the metabolic syndrome in this area of the Canary Islands is greater than that observed in most other European populations.

Adult↗
PubMed2004

Reaction intermediates in acid catalysis by zeolites: prediction of the relative tendency to form alkoxides or carbocations as a function of hydrocarbon nature and active site structure.

The mechanism of protonation of ethene, propene, and isobutylene adsorbed on seven different Brønsted acid sites of mordenite has been studied at the ONIOM (B3PW91/6-31G(d,p):MNDO) theoretical level to assess the influence of olefin size and local geometry of the active site on the species and energies involved. The activation energies for olefin protonation are determined by short- and medium-range electrostatic effects and reflect the order of stability of primary, secondary, and tertiary carbenium ions. On the other hand, the stability of covalent alkoxides depends linearly on the AlO(b)Si angle value in the complex, which in turn is determined by the corresponding value in the deprotonated zeolite. It is also shown that the mechanism of protonation of isobutylene is different from that of ethene and propene and involves a free tert-butyl carbenium ion as a true reaction intermediate. Whether this carbenium ion is converted into a covalent alkoxide depends on the T position on which the Al is located. All these findings allow us to predict, on the basis of the position and local geometry of the Brønsted acid site, whether the reaction intermediates of olefin protonation will be covalent alkoxides or free carbenium ions.

Journal Article↗
PubMed2004

Clinical manifestations and hormonal profile of two women with Cushing's disease and mild deficiency of 21-hydroxylase.

The development of Cushing's disease among patients with deficiency of 21-hydroxylase has not been observed to date. The clinical manifestations and the hormonal profile of this exceptional association are herein described through the study of two cases. The first one was a 39-yr-old woman who had undergone non-curative transsphenoidal surgery for a pituitary-dependent Cushing's syndrome 12 yr before. She showed hypertension, central obesity, severe hirsutism, alopecia and hyperpigmentation. Urinary excretion of cortisol was normal, but ACTH levels were very high and hormonal dynamic studies (cortisol circadian rhythm, insulin-induced hypoglycemia and dexamethasone suppression tests) revealed the qualitative disturbances that characterize Cushing's disease. Serum concentrations of androstenedione, free testosterone and 17-hydroxyprogesterone were clearly increased. Reexamination of the tissue samples from previous surgery confirmed the presence of an ACTH-producing pituitary adenoma. CYP21 gene analysis found the splicing 655G mutation at intron 2 and the V281L mutation at exon 7. The second case was a 21-yr-old woman who was diagnosed with pituitary ACTH-dependent Cushing's syndrome according to unequivocal clinical and laboratory findings. However, hirsutism was particularly severe and both serum androgens and 17-hydroxyprogesterone were elevated. The patient was heterozygote for a large conversion of CYP21 gene. In these cases, the clinical and biochemical expression of Cushing's syndrome was determined by the different severity of 21-hydroxylase deficiency and the subsequent residual ability of adrenal cortex to synthesize cortisol.

Adenoma↗
PubMed2002

Effects of tamoxifen on lipid profile and coagulation parameters in male patients with pubertal gynecomastia.

BACKGROUND/AIM: The estrogenic actions of tamoxifen on lipid profiles and hemostasis have been extensively demonstrated in women. Due to limited experience with this drug in males, it is uncertain whether these effects are also present in men. The aim of our study was to assess the response of blood lipids, lipoproteins, and coagulation parameters in a group of men taking tamoxifen. METHODS: We studied 15 healthy boys with pubertal gynecomastia who were given 10 mg tamoxifen per day. Total testosterone, sex-hormone-binding globulin, estradiol, serum lipids, apolipoprotein B, apolipoprotein A-I, lipoprotein(a), fibrinogen, antithrombin III, von Willebrand factor, and markers of activated coagulation and fibrinolysis were determined at baseline and 1 and 3 months after beginning of the tamoxifen treatment. RESULTS: Total cholesterol and lipoprotein(a) showed moderate but significant decreases from baseline. Low-density lipoprotein and high-density lipoprotein cholesterol concentrations as well as triglyceride and apolipoprotein B levels became lower, but these changes were not statistically significant. Among clotting parameters, antithrombin III was reduced, and von Willebrand factor increased significantly. Markers of activated coagulation and fibrinolysis remained unchanged throughout the period of therapy. CONCLUSIONS: The effects of tamoxifen on blood lipids and hemostasis we found in this group of healthy young men were qualitatively similar, but lesser than those previously described in women.

Adolescent↗
PubMed2001

Cluster and periodic calculations of the ethene protonation reaction catalyzed by theta-1 zeolite: influence of method, model size, and structural constraints.

The protonation of ethene by three different acid sites of theta-1 zeolite was theoretically studied to analyze the extent and relevance of the following aspects of heterogeneous catalysis: the local geometry of the Brønsted acid site in a particular zeolite, the size of the cluster used to model the catalyst, the degree of geometry relaxation around the active site, and the effects related to medium- and long-range interactions between the reaction site and its environment. It has been found that while the reaction energy is very sensitive to the local geometry of the site, the activation energy is mainly affected by the methodology used and by electrostatic effects on account of the carbocationic nature of the transition state.

Journal Article↗
PubMed2001

[Central diabetes insipidus as clinical presentation of a bronchogenic adenocarcinoma].

Metastatic tumors of the pituitary gland are uncommon. The majority of them are silent lesions incidentally discovered at autopsy. In contrast, the occurrence of symptomatic metastases is exceptional. Here we report the clinical and radiological findings of a 45 year-old woman with a metastatic lung adenocarcinoma who presented with diabetes insipidus and hypernatremic dehydration. There was no previous history of malignancy, and the pituitary metastases were responsible for the first manifestation of the disease. Clinical presentation, diagnosis and therapeutic management of patients with pituitary metastases are reviewed.

Adenocarcinoma↗
PubMed1998

Oxidant-antioxidant imbalance in blood of children with juvenile rheumatoid arthritis.

Juvenile rheumatoid arthritis (JRA) is the most commonly diagnosed rheumatic disease in children and may represent not a single disease, but rather a syndrome of diverse aetiologies in which inflammation is an exceedingly complex process. Oxidative free radical production at inflammation sites contributes to tissue damage and could also play a significant role in the pathogenesis of JRA. The aim of this study was to evaluate the antioxidant status and lipid peroxidation parameters related to the clinical form of JRA. Plasma malondialdehyde and hydroperoxide concentrations in children with polyarticular and systemic JRA subtypes were significantly higher than in controls. Plasma vitamin E and beta-carotene levels of the JRA children were lower in the three forms compared with healthy children. Patients with JRA present an imbalance in the oxidant-antioxidant system that manifests clearly in the polyarticular and systemic forms through an increase in lipoperoxidation products and significant decrease in the lipid-soluble antioxidants vitamin E and beta-carotene.

Antioxidants↗
PubMed1997

The long-term outcome of pituitary irradiation after unsuccessful transsphenoidal surgery in Cushing's disease.

BACKGROUND: Irradiation of the pituitary is widely considered the most appropriate treatment for patients with Cushing's disease in whom transsphenoidal microsurgery has been unsuccessful. However, there is little information about the long-term efficacy of this treatment. METHODS: We used external pituitary radiation to treat 30 adult patients with persistent or recurrent Cushing's disease after unsuccessful transsphenoidal surgery. The mean (+/-SD) dose of radiation was 50+/-1 Gy. Pituitary and adrenal function was assessed every six months after radiation therapy. Remission was defined as the regression of symptoms and signs of Cushing's syndrome, normal urinary cortisol excretion, and a low plasma cortisol concentration in the morning after the administration of 1 mg of dexamethasone at midnight. RESULTS: Twenty-five patients (83 percent) had remissions during a median follow-up of 42 months (range, 18 to 114). The remissions began 6 to 60 months after radiation therapy, but in most cases (22 patients) remission occurred during the first 2 years. None of the 25 patients had a relapse of Cushing's disease after remission was achieved. There was no relation between the response to radiotherapy and sex, age, urinary cortisol excretion before radiotherapy, the interval between surgery and radiotherapy, whether a pituitary adenoma was found by pathological examination, or tumor size. Seventeen patients had a deficiency of growth hormone after radiation therapy, 10 had a deficiency of gonadotropins, 4 had a deficiency of thyrotropin, and 1 had a deficiency of corticotropin. CONCLUSIONS: Pituitary irradiation is an effective and well-tolerated treatment for patients with Cushing's disease in whom transsphenoidal surgery is unsuccessful.

Adolescent↗
PubMed1997

Subclinical Cushing's syndrome due to adrenal myelolipoma.

We describe a patient with an incidental adrenal myelolipoma associated with biochemical evidence of Cushing's syndrome who lacked the physical stigmata of cortisol excess (subclinical Cushing's syndrome). Pathologic examination revealed the presence of adrenocortical cells mixed with myelolipomatous tissue. Although cases of clinically evident Cushing's syndrome due to adrenal myelolipomas have been reported previously, to our knowledge this is the first report associating adrenal myelolipoma and subclinical Cushing's syndrome.

Adrenal Gland Neoplasms↗
PubMed1996

Petrosal sinus sampling for diagnosis of Cushing's disease: evidence of false negative results.

OBJECTIVE: While inferior petrosal sinus (IPS) sampling correctly diagnoses pituitary-dependent Cushing's syndrome if a significant ratio of plasma ACTH between the IPS and the peripheral blood is demonstrated, little has been said about the significance of a negative ratio in Cushing's disease (e.g. a false-negative result). This study evaluates the results of IPS sampling in patients with Cushing's disease, and compares them with both imaging findings and transsphenoidal examination. DESIGN: The results of IPS sampling were retrospectively compared with both imaging findings and transsphenoidal examination. IPS samples were obtained before and 2, 5 and 10 minutes after intravenous administration of 100 micrograms of CRH. PATIENTS: Thirty-two patients with Cushing's disease were evaluated. All subsequently underwent transphenoidal examination of the pituitary gland. MEASUREMENTS: The ratio of the ACTH concentrations at the IPS and in the peripheral blood (IPS:P ratio), and the ratio of the ACTH concentrations between the IPSs (interpetrosal ratio) were calculated. Radiographic evaluation of the pituitary gland was performed with magnetic resonance imaging (MRI, 29 cases) or computed tomography imaging (CT, 3 cases). RESULTS: Transsphenoidal examination of the pituitary gland revealed a microadenoma in 27 cases. Radiological imaging showed a signal compatible with a microadenoma in 22 cases (68.8%), and correctly located the tumour at the side found at surgery in 14 of the 22 cases with positive transsphenoidal findings (MRI 13 cases, CT 1 case, overall 63.6%). Successful bilateral catheterization was accomplished in 30 patients (93.8%). Samples before and after CRH stimulation were drawn in 24 cases. No major complications were observed with the technique. IPS catheterization correctly predicted Cushing's disease (by means of a significant IPS: P ACTH ratio) in 27 of the 30 patients (90%) with basal sampling, and in 23 of the 24 cases with samples drawn before and after CRH administration (95.8%). Taking into account the 12 patients with a lateral microadenoma shown at transsphenoidal examination, IP sinus ACTH ratio was in agreement with the side recorded by the neurosurgeon in 8/12 cases (66.7%). MRI correctly located the tumour in 8/12 patients (66.7%). One patient showed no significant IPS: P ACTH ratio in any set of samples. His MRI showed no sign of a microadenoma. Two years later, another pituitary MRI evaluation showed a midline hypodense signal. The transsphenoidal examination revealed a microadenoma and the post-operative plasma cortisol and urinary free cortisol fell to 293 nmol/l and 100 nmol/24 h, respectively. CONCLUSIONS: Only when a significant IPS:P ACTH ratio is present can Cushing's disease be established by IPS sampling. The absence of a significant IPS: P ACTH ratio does not necessarily imply ectopic secretion of ACTH, nor does it exclude Cushing's disease. The results of lateralization by IPS sampling do not remove the need for a thorough transsphenoidal examination of the contents of the sella turcica.

Adenoma↗
PubMed1996

Childhood sclerodermatomyositis: report of a case with the anti-PM/Scl antibody and mechanic's hands.

We report a boy with overlap manifestations of systemic sclerosis and dermatomyositis (sclerodermatomyositis) whose disease showed a changing clinical pattern, and who had mechanic's hands, which are a cutaneous marker of myositis. Serological studies revealed antinuclear antibodies with a homogeneous nucleolar pattern. The anti-PM-Scl antibody was demonstrated by immunoblotting. HLA typing was positive for HLA-DR3/4. After a follow-up period of 11 years, no progression to severe systemic involvement was detected, and aggressive treatment was not administered. The recognition of subsets of patients with homogeneous clinical features and serological markers should permit the recognition of separate conditions among overlap syndromes. This would have prognostic and therapeutic implications.

Antibodies, Antinuclear↗
PubMed1995

The role of antiphospholipid antibodies in lupus nephropathy.

Although several clinical and morphological changes observed in overt systemic lupus erythematosus have been associated with the presence of antiphospholipid antibodies (aPL), the relation between these antibodies and lupus nephropathy (LN) is not clear. Twenty-three patients with biopsyproved LN were retrospectively studied (average age 28.5 +/- 12.3 years, all women) in order to investigate the relationship between the presence of aPL and clinical and immunobiological data. The average follow-up period was 55 +/- 42 months. The presence of aPL (IgG and IgM) was detected at least once in all patients by ELISA and/or lupus anticoagulant (kaolin time). Seven patients (30.4%) were aPL+, and the remainder aPL-. We did not find differences related to age, period of follow-up, blood pressure and livedo reticularis. However the prevalence of thrombosis, strokes and hemolysis was slightly higher in the aPL+ patients. The levels of antinuclear antibodies or anti-DNA antibodies, immunoglobulins and complement serum levels (C3, C4) were also similar in both groups. In the aPL+ group, proteinuria was significantly higher than in aPL- cases (2.21 +/- 1.5 and 0.91 +/- 1.07 g/24 h, respectively; p = 0.029). The renal histological pattern in both series was similar. However, microthrombosis in the glomerular capillary lumens was more frequent in the aPL+ group. The evolution of renal function was less favorable in aPL+ patients when compared with aPL- patients. We conclude that the presence of aPL in patients with LN is associated with several characteristics of renal impairment which may contribute to its evolution.

Adult↗
PubMed1995

[The adult respiratory stress syndrome and septic shock associated with tuberculosis].

The increase in the incidence of tuberculosis infection in the last few years has caused a recurrence of atypical clinical forms, as well as the development of associations and uncommon complications during the clinical course, which include the adult respiratory distress syndrome (ARDS) and septic shock. Three patients with ARDS are here reported; two patients had findings of septic shock and negative serology to human immunodeficiency virus and the only etiological agent documented was M. tuberculosis. The three patients required hemodynamic support and two of them mechanical ventilation. None of the patients survived the episode. Tuberculosis, particularly the disseminated forms, should be considered as possible etiology in high risk patients with septic shock, ARDS or both.

Adult↗
PubMed1994

Juvenile rheumatoid arthritis of the knee: evaluation with US.

PURPOSE: To evaluate the value of ultrasound (US) in assessing joint inflammation in patients with juvenile rheumatoid arthritis (JRA) of the knee. MATERIALS AND METHODS: US scans obtained in 36 children (mean age, 8 years) with JRA of the knee were compared with those obtained in 30 healthy children. RESULTS: Changes in synovial membrane (synovial thickness), presence of fluid in the suprapatellar bursa, and alterations in the contour (blurring) of the articular cartilage showed statistically significant differences between JRA patients and control subjects. US was more sensitive than physical examination for detecting a minimal amount of intra-articular fluid in 21% of JRA-affected knees with no clinical evidence of active disease. CONCLUSION: US is a simple, rapid, inexpensive, and accurate method for assessing joint inflammation in patients with JRA of the knee.

Adolescent↗