We study theoretically and experimentally spectrally flat and broadband double-pumped fiber-optical parametric amplifiers (2P-FOPAs). Closed formulas are derived for the gain ripple in 2P-FOPAs as a function of the pump wavelength separation and power, and the fiber non-linearity and fourth order dispersion coefficients. The impact of longitudinal random variations of the zero dispersion wavelength (lambda(0)) on the gain flatness is investigated. Our theoretical findings are substantiated with experiments using conventional dispersion shifted fibers and highly nonlinear fibers (HNLFs). By using a HNLF having a low variation of lambda0 we demonstrate high gain and flat spectrum (25 +/- 1.5 dB) over 115 nm.

OBJECTIVE: To estimate the prevalence and factors associated with sexual abuse in childhood and adolescence. METHODS: Study conducted in a sample of students in the state of Morelos, Mexico, in 2004-2005. Participants (n=1730) were drawn from a cohort of 13,293 students aged 12 to 24 years. Data were collected by means of a questionnaire comprising parts of validated scales. The variables studied were: sociodemographic (gender, living area, socioeconomic status), family (parental education, parental addictions, violence between parents), individual psychological factors (self-esteem assessed using the Coopersmith Self-Esteem Inventory, depression, alcohol consumption), intrafamily violence (assessed through Strauss Scale) and sexual abuse. Multiple logistic regression assessed the risk factors associated. Odds ratios (OR) with 95% confidence intervals were estimated. RESULTS: Of all students studied, 4.7%(n=80) reported attempted sexual abuse and 2.9%(n=50) were victims of consummated sexual abuse. Women had higher prevalence of attempted (6.1%) abuse; 3.6% of females and 1.9% of men were sexually abused. Main perpetrators were boyfriends in women and a stranger in men. Mean age was 12.02 years old among females and 11.71 years old among men. Factors found to be associated with abuse: high parental alcohol consumption (OR = 3.37, 95% CI 1.40;8.07), violence toward the mother (OR = 4.49, 95% CI 1.54;13.10), female gender (OR = 2.47, 95% CI 1.17;5.24), being a victim of great domestic violence (OR = 3.58, 95% CI 1.32;9.67). High self-esteem was a protective factor (OR = 0.27, 95% CI 0.09;0.75). CONCLUSIONS: Overall sexual abuse occurs at the age of 12 in both males and females, and it is more frequent among females. Most victims do not report abuse.

Skin manifestations have been described in 10-15% of patients with inflammatory bowel disease (Crohn's disease, ulcerative colitis, indeterminate colitis/inflammatory bowel disease type unclassified). There are limited data on the prevalence of these manifestations in paediatric patients, but recent studies have reported its presence in 8% of them at diagnosis. Our aim is to report the different skin manifestations observed in our paediatric patients with inflammatory bowel disease. Case 1: Erythema nodosum at Crohn's disease diagnosis. Typical presentation with painful erythematous nodules in the pretibial region and with good response to infliximab. Case 2: Coexistence of pyoderma gangrenosum and mucocutaneous Sweet's syndrome in a Crohn's disease patient. A rapidly progressive disease that was controlled with systemic steroids but with significant residual lesions. Case 3 and 4: Metastatic Crohn's disease with good response to infliximab.

A record 730 nm parametric conversion in silica fiber from the near-infrared to the short-wave infrared band is reported and analyzed. A parametric gain in excess of 30 dB was measured for a signal at 1300 nm (with corresponding idler at 2030 nm). This conversion was performed in a travelling single-pass one-pump parametric architecture and high efficiency is achieved by a combination of high peak power and a nonlinear fiber with a reduced fourth-order dispersion coefficient.

OBJECTIVE: To determine whether the risk factors described in the literature are applicable to our population or not. MATERIAL AND METHODS: A case and control study was undertaken. Seventy patients with an imaging-confirmed diagnosis of lumbar stenosis were included as well as 70 controls that denied having any of the following symptoms: chronic lumbar pain, claudication, sensory alterations and muscle weakness of the lower limbs. A survey to identify risk factors possibly associated with lumbar stenosis was carried out. The statistical analysis was done with non-conditional logistic regression and the risks were determined by means of an odds ratio (OR) in both a univariate and a multivariate modality. RESULTS: One hundred and forty individuals of both genders were included; 70 cases and 70 controls. The factors that were found to be significant in the univariate analysis were included in the multivariate analysis. The OR for age was 7.6 (CI 95%= 2.81-20.93; p = 0.0001), for scoliosis, 5.14 (IC 95%= 1.27-20.77; p = 0.021), for SAH, 1.82 (IC 95%= 0.74-4.48; p = 0.19) and for neoplasias, 2.55 (IC 95%= 0.22-29.23; p = 0.45). CONCLUSION: This study showed that age over 65 years, scoliosis and systemic arterial hypertension are risk factors for lumbar stenosis. The multivariate analysis showed that age increases the risk in the presence of scoliosis.

Background: Delirium is a common underdiagnosed and undertreated problem in elderly inpatients, associated to higher morbidity, mortality and health cost. Aim: To evaluate the prevalence of delirium at hospital admission in medically ill elderly patients and the attending physician's diagnosis and treatment of delirium. Patients and methods: In a prospective and descriptive study, consecutive patients aged 65 years or more, admitted to an internal medicine ward were evaluated by independent physicians, during the first 48 h of admission, to asses the presence of delirium. Diagnosis of delirium was based on the Confusion Assessment Method. Medical and nurse records were reviewed. Family was interviewed when necessary. Results: One hundred eight patients (52% women, age range 65-94 years) with an APACHE II score of 11.6+/-5, were evaluated. Fifty seven patients (53%) had delirium (32% hyperactive, 72% hypoactive and 5% mixed). Delirium prevalence was significantly higher in older patients (66% among those aged 75 years or older versus 30% in younger, p <0.05) and among patients with more severe conditions (88% among those with an APACHE score over 16 versus 47% below that value, p <0.05). Medical records of patients with delirium showed that this diagnosis was present only in 32% and cognitive deficit was described in 73%. Ten percent of patients with delirium received sedative medication and 38% were physically restricted. There were no environmental interventions to prevent or control delirium. Conclusions: Delirium in elderly inpatients at this unit is an extraordinarily prevalent problem, seriously under diagnosed (68%) and under treated. This study should alerts our medical community to improve the diagnosis and management of delirium in elderly inpatients (Rev Méd Chile 2005; 133: 1449-54).

The main characteristics of the specialization course in Family Medicine given at the IMSS since March 2002 are described. We show the epistemological and methodological principles that support the plan of studies. The most important are a closer relationship between theory and practice, the development of clinical aptitudes through the study of problematic clinical cases, and methodological aptitudes such as the development of critical reading of theoretical texts and bibliographic and operative research. This continuing education strategy not only lowers the costs of formal education but also contributes to increasing the quality of medical care given at the first level family medical units.