A review of refractometric sensors based on long period fibre gratings.

In the last decade refractometric sensors have attracted an increasing interest by the scientific community due to their ability to perform ambient monitoring, to assess food quality and safety, and also to the fact that they enable the development of label free sensors in the biomedical area. These advances result, namely, from the use of long period fibre gratings in the turning points and/or with thin films in the transition region that allows resolutions of 10(-6) to changes in the refractive index of the surrounding medium. Resolutions exceeding 10(-8) can also be achieved when long period fibre gratings are combined with evanescent field based devices. This paper reviews the recent path towards the development of ultrahigh sensitive optical fibre refractometric sensors.

Origin of coupling to antisymmetric modes in arc-induced long-period fiber gratings.

We study the origin of antisymmetric perturbation of the fiber in arc-induced long-period gratings that couple the core mode into the antisymmetric cladding modes. We demonstrate that this perturbation is caused by the temperature gradient in the fiber, which is induced, in turn, by the temperature gradient in the arc discharge. The reproducibility of the process of the grating inscription is higher when the fiber is placed in a region with larger temperature gradient.

[Recommendations for the use of methotrexate in patients with juvenile idiopathic arthritis]. / Recomendaciones para el uso de metotrexato en pacientes con artritis idiopática juvenil.

OBJECTIVES: To develop a consensus document of recommendations for the use of methotrexate (MTX) in patients with juvenile idiopathic arthritis (JIA). MATERIAL AND METHOD: A group of eleven experts proposed several clinical questions on the use of MTX in patients with JIA. A systematic review was conducted and the evidence and recommendations for each question were extracted. The results were discussed and validated by the experts in a work session to establish the final recommendations. RESULTS: MTX is recommended as the first drug for inducing remission in JIA, and its indication should be made according to the clinical category of the patient. Prior to treatment, it is recommended to perform a complete blood count, including white cells, levels of liver enzymes, serum creatinine, and other analytical parameters according to specific risk factors. Treatment should be initiated with a dose of 10-15 mg/m(2)/week. In cases of uveitis or polyarthritis, an initial dose of 15 mg/m(2)/week should be considered. For a better bioavailability and tolerability, it is preferable to administer MTX parenterally if the dose is ≥15 mg/m(2)/week. It is necessary to periodically perform an analytical monitoring of the patient and to assess possible alterations in liver enzymes to make changes if necessary. Combinations with biological agents may be necessary, as well as the concomitant addition of folic or folinic acid. CONCLUSIONS: This document describes the main recommendations for the appropriate use of MTX in JIA patients, according to scientific evidence and clinical experience.

Respiratory disease in aggregate quarry workers related to risk factors and Pi phenotype.

OBJECTIVE: To evaluate the respiratory health and its relationship with exposure to silica, smoking, alpha 1-antitrypsin, and Pi phenotype in aggregate quarries workers. METHODS: In a prevalence study, 378 subjects were studied, x-ray opacities and pulmonary function was analyzed in relation to cumulative dust exposure, smoking, alpha1- antitrypsin, and Pi phenotype. RESULTS: The adjusted odds ratio (OR) of round opacities (> or =0/1) was significantly related to smoking (P <0.001). The predicted forced expiratory volume in 1 second (FEV1) percentage had a negative relationship with the product dust. pack-years (P = 0.005). The OR of FEV1 <90% was 3.03 for smokers exposed to dust versus nonexposed nonsmokers (P = 0.049). The criteria for dust-tobacco interaction are satisfied. A subgroup with the highest level of alpha1-antitrypsin presented more opacities and worse pulmonary function. CONCLUSIONS: Radiologic alterations are found in relation to tobacco. The FEV1 has a negative relation with the product dust-tobacco. No alterations related to Pi phenotype are found. A subgroup with the highest alpha1-antitrypsin levels had more radiologic alterations and worse function.

[Value of computerized tomography in the diagnosis of complicated pneumoconiosis in coal miners]. / Valor de la tomografía computarizada en el diagnóstico de neumoconiosis complicada de mineros del carbón.

To assess the value of computed tomography (CT) scanning for the diagnosis of complicated pneumoconiosis, or progressive massive fibrosis (PMF), we conducted a prospective study of 127 subjects who had worked in coal mines for at least 15 years. Sixty-two suffered simple pneumoconiosis (nodular profusion > or = 1/1 under the ILO-80 international classification system) visible on simple chest films. None were diagnosed of PMF on the basis of X-ray evidence. CT led to a diagnosis of PMF in 8 cases (6.3%; CI 95%, 2.68-11.82). PMF was category A in all 8; all of them had had chest film evidence of simple pneumoconiosis. Six (75% of these patients had q and/or r nodulation; in 5 (62.5%) the nodules tended to confluence. These figures were significantly higher (p < 0.05, Fisher's test) than in the group of patients with no PMF, among whom 54 (45.3%) had SP, 2 (1.68%) had q and or r nodulation and 3 (2.52%) tended to confluence. We observed no differences in FVC, FEV1, the FEV1/FVC ratio or DLCO between the PMF and non PMF groups. Our results suggest that CT scans can be useful for diagnosing PMF in some cases in which it is suspected bases on chest X-ray findings (simple pneumoconiosis, q and/or r nodulation, tendency to confluence).

[Characteristics of lung cancer in patients exposed to silica at work. A comparison of exposed and non-exposed individuals]. / Características del cáncer de pulmón en pacientes con exposición laboral a la sílice. Estudio comparativo entre individuos expuestos y no expuestos.

INTRODUCTION: In 1977 silica was listed as a group 1 carcinogen (demonstrated in humans) by the International Agency for Research on Cancer. However, conflicting results from various studies have kept debate alive as to its carcinogenic capacity. The interest of this debate lies in the large number of workers exposed to silica. OBJECTIVE: To analyze the differential characteristics of lung cancer among silica exposed and silica non-exposed individuals, to identify indirectly a possible carcinogenic effect of silica. METHODS: For all males with a diagnosis of lung cancer over a period of 22 consecutive months at the National Silicosis Institute (Oviedo, Spain), we recorded work history, age, smoking habits, spirometry, the presence of pneumoconiosis and histology. RESULTS: Comparing the results for silica exposed and non-exposed individuals, we found significant differences for age (63.7 8.8 and 66.7 8.6 y, respectively; p < 0.05), smoking (44.1 22.4 and 48.9 22.3 packs/year; p < 0.05) and a Tiffeneau index under 70% (in 78% of exposed vs. 55% of non-exposed patients; p < 0.05). No significant differences in histology, signs and symptoms or radiographs were observed between the two groups. In the multifactorial analysis in function of age of onset, exposure to silica continued to be an independent predictor. CONCLUSION: Our results show that the clinical and radiological signs and histology of patients exposed or non-exposed to silica did not differ. However, lung cancer appears earlier among individuals with work-related exposure to silica and lower rates of tobacco smoking, suggesting some carcinogenic effect for silica.

[The effects of dust inhalation in slate industry workers]. / Efectos del polvo inhalado en los trabajadores de la industria de pizarras.

BACKGROUND: Slate industries involve the risk of causing silicosis; these industries are now on the increase, which implies an increasing number of workers too. The effects of this type of mining on respiratory health are not yet known. SUBJECTS AND METHOD: A cross section study of active workers. Radiological and functional alterations, and their relation to risk factors, were assessed. RESULTS: A prevalence of 2.1% simple pneumoconiosis was found. The value of the FEV1 probed to be significantly related to smoking and to existence of nodulation of a 1/0 or higher profusion; these risk factors, when multiple regression is applied, work independently. CONCLUSION: Slate industry involves a risk of pneumoconiosis and other respiratory alterations.

[Advances in the treatment of secondary osteoporosis]. / Avances en el tratamiento de la osteoporosis secundaria.

Osteoporosis is being increasingly recognised in paediatric practice as a consequence of the increasing life expectancy of children who suffer from chronic diseases and other factors. There are many non-pharmacological measures that can improve children' bone health, for example, avoiding inflammatory activity and osteotoxic treatments; increasing sun exposure and weight-bearing exercise, and maintaining an adequate nutritional status. Vitamin D and calcium supplements have been proposed as a measure to increase bone mass, but their effect and therapeutic indications are not completely clear. On the other hand, bisphosphonates are currently the only pharmacological alternative for the patients with infantile secondary osteoporosis. However, more studies are required on the therapeutic indications, posology, and long term secondary effects of biphosphonates. The aim of this article is to analyze the scientific evidence of the effectiveness of the therapeutic alternatives for childhood secondary osteoporosis and their safety in children.

Ethical and legal issues in xenotransplantation.

In most western countries, there is a 'human organ shortage' with waiting lists for the performance of transplantation. In a recent report of the UNOS Ethics Committee it is stated that there are approximately 31,000 potential recipients on waiting lists, but only one fourth of potential donors give their specific consent. Xenotransplantation--defined as the transplantation of animal cells, tissues or organs into human beings--is associated with particular ethical dilemmas, namely the problems of efficiency and safety of this medical procedure. The objective of this study is to analyse the ethical dilemmas in xenotransplantation with the background of a personal view of moral life. Also, xenotransplantation will be evaluated as far as the legal regulation of transplantation is concerned. In particular, we will consider patients rights in accordance with existing laws on organ and tissue transplantation, animal research and clinical trials.

Presence of acute phase response in coal workers' pneumoconiosis.

To evaluate the role of personal factors in pneumoconiosis, several acute phase proteins were studied in 62 coal miners without acute illnesses and classified as having no pneumoconiosis (n = 19), simple pneumoconiosis (n = 23), or complicated pneumoconiosis with progressive massive fibrosis (n = 20). Groups were similar for age, years of work at high risk jobs, chronic bronchitis, and forced expiratory volume in one second (FEV1). C-reactive protein concentration was significantly higher in the simple and complicated pneumoconiosis groups in comparison with the no pneumoconiosis group. The C-reactive protein concentration was above the upper normal value in 12 (27.9%) out of 43 cases with simple and complicated pneumoconiosis. On the other hand only one case of no pneumoconiosis was above the upper normal range (5.3%), a significant difference taking into account a stratified analysis for chronic bronchitis. Fibrinogen concentration was significantly increased in the simple pneumoconiosis group compared with the no pneumoconiosis group. The value of fibrinogen was above the upper normal limit in 17 out of the 43 cases with pneumoconiosis (39.5%) by contrast with two cases in the no pneumoconiosis group (10.5%). No significant differences in alpha 1-antitrypsin and ceruloplasmin concentrations were found between groups. In conclusion, an alteration in some acute phase proteins related to pneumoconiosis was found in miners. This could be used as a marker of disease activity and personal response against the pathogenic agent.