Individual spatial aggregation correlates with between-population variation in fine-scale genetic structure of Silene ciliata (Caryophyllaceae).

Fine-scale genetic structure (FSGS) can vary among populations within species depending on multiple demographic and environmental factors. Theoretical models predict that FSGS should decrease in high-density populations and increase in populations where individuals are spatially aggregated. However, few empirical studies have compared FSGS between populations with different degrees of individual spatial aggregation and microhabitat heterogeneity. In this work, we studied the relationship between spatial and genetic structure in five populations of alpine specialist Silene ciliata Poiret (Caryophyllaceae). We mapped all individuals in each population and genotyped 96 of them using 10 microsatellite markers. We found significant FSGS consistent with an isolation-by-distance process in three of the five populations. The intensity of FSGS was positively associated with individual spatial aggregation. However, no association was found between FSGS and global population density or microhabitat heterogeneity. Overall, our results support theoretical studies indicating that stronger spatial aggregation tends to increase the magnitude of FSGS. They also highlight the relevance of characterizing local plant distribution and microhabitat to better understand the mechanisms that generate intraspecific variation in FSGS across landscapes.

Exploiting nonreciprocity in BOTDA systems.

In this Letter, we present and demonstrate a novel technique for distributed measurements in Brillouin optical time-domain analysis based on the use of the nonlinear phase-shift induced by stimulated Brillouin scattering. Employing a Sagnac interferometer (SI), the position-resolved Brillouin phase-shift spectrum (BPS) along the fiber can be obtained, benefiting from the sensitivity to nonreciprocal phase-shifts of the SI scheme. This proposal simplifies the existing methods to retrieve the BPS distribution along an optical fiber since phase modulation, filtering, and high-bandwidth detectors are not required. The fundamentals of the technique are described theoretically and validated through numerical simulations and experimental measurements.

Evaluation of head-of-bed elevation compliance in critically ill patients under mechanical ventilation in a polyvalent intensive care unit.

OBJECTIVES: To evaluate head-of-bed elevation (HOBE) compliance in mechanically ventilated (MV) patients during different time periods, in order to identify factors that may influence compliance and to compare direct-observation compliance with checklist-reported compliance. DESIGN AND SETTING: A prospective observational study was carried out in a polyvalent Intensive Care Unit. PATIENTS: All consecutive patients with MV and no contraindication for semi-recumbency were studied. INTERVENTION AND VARIABLES: HOBE was observed during four periods of one month each for one year, the first period being blinded. HOBE was measured with an electronic device three times daily. Main variables were HOBE, type of airway device, type of bed, nursing shift, day of the week and checklist-reported compliance. No patient characteristics were collected. RESULTS: During the four periods, 2639 observations were collected. Global HOBE compliance was 24.0%, and the median angle head-of-bed elevation (M-HOBE) was 24.0° (IQR 18.8-30.0). HOBE compliance and M-HOBE by periods were as follows: blinded period: 13.8% and 21.1° (IQR 16.3-24.4); period 1: 25.5% and 24.3° (IQR 18.8-30.2); period 2: 22.7% and 24.4° (IQR 18.9-29.6); and period 3: 31.4% and 26.7° (IQR 21.3-32.6) (p<0.001). An overestimation of 50-60% was found when comparing self-reported compliance using a checklist versus direct-observation compliance (p<0.001). Multivariate logistic regression analysis found the presence of an endotracheal tube (ET) and bed without HOBE measuring device to be independently associated to greater compliance (p<0.05). CONCLUSIONS: Although compliance increased significantly during the study period, it was still not optimal. Checklist-reported compliance significantly overestimated HOBE compliance. The presence of an ET and a bed without HOBE measuring device was associated to greater compliance.

Evaluación del cumplimiento de la elevación de la cabecera de la cama en pacientes críticamente enfermos sometidos a ventilación mecánica en una unidad de cuidados intensivos polivalente / Evaluation of the compliance with the elevation of the head of the bed in critically ill patients undergoing mechanical ventilation in a polyvalent intensive care unit

Objetivos. Evaluar el cumplimiento de la elevación de la cabecera de la cama (ECC) en pacientes atendidos con ventilación mecánica (MV) durante distintos periodos de tiempo con el fin de identificar losfactores que pueden influir sobre el cumplimientoy comparar el cumplimiento evaluado mediante observación directa con el cumplimiento evaluado mediante lista de verificación...

[Validation of a diagnostic questionnaire for migraine adapted for a computer assisted telephone interviewing]. / Validación de un cuestionario diagnóstico para migraña adaptado para encuesta telefónica asistida por ordenador.

INTRODUCTION: the use of questionnaires is a tool for obtaining information on cases and the variables to analyse in migraine study populations. METHODS: we have validated the questionnaire within the PALM study, based on IHS-II criteria and administered by telephone using computer assisted sampling (CATI). The questionnaire has been validated using 50 randomly selected subjects, who had been assessed blind by a neurologist expert in migraine. RESULTS: of the 24 patients diagnosed with strict migraine with the CATI interview, only in 2 (8%) of them did the neurologist determine that they did not suffer from migraine. Furthermore, of the patients in whom the diagnostic questionnaire concluded that they did not suffer from migraine, the specialist did not establish that diagnosis in any of them either. The analysis showed a sensitivity of 81.5% (95% CI, 66.8%-96.1%) and a specificity of 91.3% (95% CI, 79.8%-100%). The positive predictive value was 91.7% and the negative was 80.8%. CONCLUSIONS: the PALM questionnaire administered by telephone with computer support is a valid tool for use in determining the prevalence of migraine in study populations.

[Afebrile convulsions and acute gastroenteritis: a more common than expected combination]. / Convulsiones afebriles y gastroenteritis aguda: una asociación más frecuente de lo esperado.

Afebrile seizures in association with acute gastroenteritis without electrolyte disturbances have been reported in children from Asiatic countries, but only few references are from Spain. It is a benign, self-limiting process, with no specific examinations or therapy needed. There is no increased risk of epilepsy or impaired neurodevelopment in the children affected. We present five children with seizures during acute gastroenteritis admitted to Hospital Universitari Arnau de Vilanova of Lleida (Spain) between December 2005 and March 2006, during the last seasonal rotavirus outbreak. Patients with febrile seizures, electrolyte disturbances or previous seizures have been excluded. Association between acute gastroenteritis and afebrile benign seizures is also common in our setting, and some cases associated to seasonal rotavirus outbreaks have been published. All papers agree with the good prognosis of this problem. To consider this diagnosis is important in order avoid unnecessary examinations or anticonvulsive therapies.

[Satisfaction and recovery of normal activity with rizatriptan 10 mg. Results from the open, prospective, observational 4M study]. / Satisfacción y retorno a la actividad normal con 10 mg de rizatriptán. Resultados del estudio abierto, prospectivo y observacional 4M.

BACKGROUND: To evaluate the impact of the treatment with rizatriptan 10 mg (Maxalt) on the return to normal activity and satisfaction with treatment in the general population with migraine. PATIENTS AND METHOD: We conducted an open, prospective study in patients with migraine (International Headache Society [IHS] criteria) who were followed for up to 3 migraine attacks. We measured the degree of functional disability at 0 and 2 hours after treatment, and satisfaction at 24 hours. Other domains of satisfaction were evaluated after three migraine attacks. The relationship between baseline pain severity, satisfaction after 24 hours and functional disability was analyzed. RESULTS: 2,469 patients were enrolled who experienced 6,323 migraine attacks. A return to normal activity was achieved two hours after treatment in 67% of all attacks treated with rizatriptan 10 mg. The percentage of attacks causing severe functional disability decreased from 39% before therapy to 3.6% two hours after treatment. In more than 90% of moderate or severe attacks, a normal or slightly impaired functional capacity was restored two hours after treatment. In 76.3% of the attacks the patients were fully or very satisfied 24 hours after treatment with rizatriptan 10 mg. After treating three migraine attacks, the proportion of patients fully or very satisfied with rizatriptan was over 79% for all the domains explored. CONCLUSIONS: The patients were highly satisfied after 24 hours and following three migraine attacks treated with rizatriptan 10 mg. In more than two-thirds of the attacks treated with rizatriptan 10 mg, the patients returned to normal activity two hours after treatment.

The effect of steady-state ropinirole on plasma concentrations of digoxin in patients with Parkinson's disease.

AIMS: The aim of this single-blind study was to assess the effect of ropinirole, a novel treatment for Parkinson's disease, on the steady-state pharmacokinetics and safety of digoxin in 10 patients with Parkinson's disease. METHODS: There were three parts to the study: digoxin once daily plus placebo three times daily for 1 week; digoxin once daily plus ropinirole three times daily for 6 weeks; and digoxin once daily plus placebo three times daily for 1 week. Serial blood samples were collected over 24 h at the end of each part of the study for pharmacokinetic assessment. Pre-dose blood samples were collected on specific days throughout the study to assess the attainment of steady-state plasma levels of digoxin. The primary endpoints were AUC(0, tau) and Cmax for digoxin. RESULTS: There was a mean decrease of 10% in digoxin AUC (0, tau) (90% CI: 0.79, 1.01) and a 25% decrease in digoxin Cmax (90% CI: 0.58, 0.97) when ropinirole was co-administered, compared with digoxin alone Cmin plasma values for digoxin, however, were fairly constant throughout the study (point estimates 0.99, 95% CI: 0.85, 1.15). Changes in trough levels of digoxin are believed to be the most reliable way of assessing steady-state concentrations of digoxin, and therefore the clinical significance of an interaction. Changes in Cmax are too readily influenced by other factors. CONCLUSIONS: These results therefore indicate that on pharmacokinetic grounds no dose adjustment is necessary for digoxin co-administered with ropinirole.

Lack of a pharmacokinetic interaction at steady state between ropinirole and L-dopa in patients with Parkinson's disease.

STUDY OBJECTIVE: To assess the interaction between therapeutic dosages of ropinirole and L-dopa plus a decarboxylase inhibitor administered at steady state in patients with Parkinson's disease. DESIGN. Open, 6-week, overlap trial with random allocation. PATIENTS: Thirty patients with Parkinson's disease not previously treated with dopamine agonists, of whom 28 produced evaluable pharmacokinetic data for ropinirole and 23 for L-dopa. INTERVENTION: Group A (14 patients) received L-dopa for weeks 1-5 and ropinirole in increasing increments for weeks 2-6; group B (16) received ropinirole for weeks 1-5 and L-dopa for weeks 5 and 6. MEASUREMENTS AND MAIN RESULTS: Primary end points were AUC0-8 and Cmax for ropinirole, and AUC0-8, AUC0-infinity and Cmax for L-dopa. Secondary end points were Tmax for ropinirole, and Tmax and half-life for L-dopa. Coadministration with L-dopa at steady state did not affect rate or extent of availability of ropinirole: point estimates of the geometric mean ratio for ropinirole plus L-dopa compared with ropinirole alone for both Cmax and AUC0-8 approximated to unity. The small (16%) increase in peak concentrations of L-dopa on administration with ropinirole is unlikely to be of clinical consequence, as peak concentrations of L-dopa are typically highly variable. CONCLUSION: There are no pharmacokinetic grounds for adjusting dosages of either ropinirole or L-dopa when given in combination.

[Toxic megacolon presenting as Crohn's disease]. / Megacolon tóxico como presentación de la enfermedad de Crohn.

We introduce a young patient, without history of inflammatory bowel disease (I.B.D.) who started with an acute gastroenteritis, which in the following days progressed to a toxic megacolon. The patient had come to hospital with nausea, vomiting, fever and liquid, explosive diarrhoea without pathologic products. There was no clinical remission with astringent diet, hydroelectrolitic reposition and antidiarrheic opiates. The patient was admitted in hospital when he had blood in the diarrhoea. This progressed to a toxic megacolon in three days and the patient had to be operated on urgently. The surgeons found perforations in the colon and the pathologists diagnosed Crohn disease. Even without previous E.B.D. history we reached the diagnosis from the clinical and analytical data and the plain abdominal radiology. It was impossible to confirm the diagnosis with a colonoscopy because of the high risk of perforation. In cases like this, early surgery may save the life of the patient.

Effect of food on the pharmacokinetics of ropinirole in parkinsonian patients.

AIMS: Ropinirole is a specific non-ergoline dopamine D2-receptor agonist with antiparkinsonian properties. The pharmacokinetic parameters of ropinirole taken in the fasted condition were compared with those when it was co-administered with food. METHODS: This was an open, randomized, two sessions cross over study in 12 patients with Parkinson's disease, comparing the steady-state pharmacokinetic profiles of ropinirole on two different study days: 'fasted' and 'fed'. RESULTS: The mean Cmax was lower in the 'fed' regimen than in the 'fasted' one (-25%, P=0.002). The median tmax was observed 2.6 h later in the 'fed' regimen than in the 'fasted' regimen (P<0.05). There was a slight but significant decrease in AUC(0,8 h) in the 'fed' regimen (P=0.03). CONCLUSIONS: Food decreases the rate of absorption of ropinirole, but has little effect on the extent of absorption.

[Bacteremia during the course of Salmonella gastroenteritis]. / Bacteriemia en el curso de gastroenteritis a Salmonella.

OBJECTIVE: Salmonella is the most frequent cause of bacterial acute gastroenteritis (AGE) in our setting. Usually its course is self-limited, but it sometimes can lead to bacteremia, principally in young infants and malnourished or immunosuppressed children. Bacteremia is less frequent in healthy people and in those over one year of age. This study was carried out to assess the incidence of bacteremia during Salmonella GE and to detect parameters that could lead to bacteremia. PATIENTS AND METHODS: A retrospective study of positive stool cultures in our hospital between 1991 and 1993 was performed. Data about the epidemiology, clinical features cultures and analytical procedures were drawn from clinical records. Data were analyzed using the Mann-Whitney test and Fisher's exact test. RESULTS: During this period of time, 860 cases of AGE were observed with 86 stool cultures positive for Salmonella (10%). Six of them also had positive blood cultures (7%). All 6 patients with bacteremia were healthy previously and five were over 12 months old. The outcome was good in all cases, without focalizations of the bacteremia. We could not detect any differences between patients with positive blood cultures and the patients without bacteremia. CONCLUSIONS: Bacteremia during Salmonella AGE is not infrequent and is not limited to young infants or patients with underlying diseases. None of the parameters analyzed were useful in predicting the possibility of bacteremia.

Biochemical and ultrastructural approaches to the onset of the pineal melatonin rhythm in the rat.

To determine the pineal gland content of melatonin during rat development and the onset of the circadian rhythm, a biochemical and ultrastructural experimental model was designed. Body and pineal gland weights and DNA and protein contents of the pineal glands increased rapidly during ontogenic development. No significant differences in the values of these parameters were observed when the data were obtained during the day or at night. Pineal melatonin content as expressed by pineal gland or by micrograms of DNA, was very small in 21-day-old fetuses and 5- and 10-day-old suckling rats and the values determined were similar for both day and night. However, in 20-day-old suckling and adult rats higher melatonin concentrations and significant differences between the values obtained during the day and at night were observed. The onset of the circadian melatonin rhythm coincided with the time at which the components involved in melatonin synthesis reached adult levels and pinealocytes adopted an adult morphological appearance as observed with the electron microscope. These results indicate that the appearance of a circadian melatonin rhythm in the rat pineal gland is delayed until the end of the suckling period, although the transfer of melatonin from the mother to the pups may be important for postnatal reproductive and somatic development.

Ultrastructural study of the distribution of calcium in the pineal gland of the rat subjected to manipulation of the photoperiod.

Using the pyroantimoniate technique, a study was conducted at electron microscope level on the distribution of the calcium ion in the pineal glands of normal adult Sprague-Dawley rats with initial weights of 150-200 g subjected to a 12:12 light dark cycle and others under the same conditions were subjected to modifications in the noradrenergic signal, such as continuous illumination over 7 days, blinding by bilateral enucleation (7 or 90 days) before sacrifice and bilateral superior cervical gangliectomy at 21 days before sacrifice. All the animals were sacrificed by decapitation, half of them at midday and the other half at midnight. Abundant fine precipitations of calcium were found in the intercellular spaces of the pineal glands of the normal rats. By contrast, in the gangliectomized animals subjected to constant illumination and chronic binding these precipitations were few in number. Additionally, two types of pinealocytes were observed regarding the distribution and concentration of intracytoplasmic calcium in both the normal and experimentally manipulated animals. Type I correspond to the classic light pinealocytes, with an absence of intracytoplasmic precipitations, although in the normal and gangliectomized animals sacrificed at midnight it was possible to observe fine deposits inside the mitochondrial matrix. Type II correspond to the classic dark pinealocytes, with a dense cytoplasmic matrix and numerous deposits of intracytoplasmic and intranuclear calcium; these were never seen in the type I pinealocytes.