Resistance exercise training does not affect plasma irisin levels of hemodialysis patients.

Irisin, a hormone secreted by myocytes induced in exercise, acts as a muscle-derived energy-expenditure signal that binds to undetermined receptors on the white adipose tissue surface, stimulating its browning and uncoupling protein 1 (UCP1) expression. The purpose of this study was to assess the effect of an intradialytic resistance exercise training program (RETP) on plasma irisin levels of hemodialysis (HD) patients and compare the baseline plasma irisin levels of HD patients to healthy subjects. This longitudinal study enrolled 26 patients undergoing HD (50% men, 44.8±14.1 years, body mass index (BMI) 23.5±3.9 kg/m²). The healthy subjects group consisted of 11 women and 7 men with mean age of 50.9±6.6 years and BMI, 24.2±2.7 kg/m². Anthropometric and biochemistry parameters (Irisin by Enzyme-Linked Immunosorbent Assay) were measured at the baseline and after 6 months of RETP (in both lower limbs). There was no difference regarding gender, age, and BMI between HD patients and healthy subjects. Plasma irisin levels in HD patients were lower than in healthy subjects (71.0±41.6 vs. 101.3±12.5 ng/ml, p<0.05). Although the muscle mass increased in consequence of exercise [evaluated by arm muscle area from 27.9 (24.1) to 33.1 (19.0) cm²], plasma irisin did not differ significantly after exercises (71.0±41.6 vs. 73.3±36.0 ng/ml). HD patients seem to have lower plasma irisin when compared to healthy subjects. Moreover, a resistance exercise training program was unable to augment plasma irisin despite increasing muscle mass.

ESMO Consensus Guidelines for management of patients with colon and rectal cancer. a personalized approach to clinical decision making.

Colorectal cancer (CRC) is the most common tumour type in both sexes combined in Western countries. Although screening programmes including the implementation of faecal occult blood test and colonoscopy might be able to reduce mortality by removing precursor lesions and by making diagnosis at an earlier stage, the burden of disease and mortality is still high. Improvement of diagnostic and treatment options increased staging accuracy, functional outcome for early stages as well as survival. Although high quality surgery is still the mainstay of curative treatment, the management of CRC must be a multi-modal approach performed by an experienced multi-disciplinary expert team. Optimal choice of the individual treatment modality according to disease localization and extent, tumour biology and patient factors is able to maintain quality of life, enables long-term survival and even cure in selected patients by a combination of chemotherapy and surgery. Treatment decisions must be based on the available evidence, which has been the basis for this consensus conference-based guideline delivering a clear proposal for diagnostic and treatment measures in each stage of rectal and colon cancer and the individual clinical situations. This ESMO guideline is recommended to be used as the basis for treatment and management decisions.

Measurement of the proton-air cross section at √s=57 TeV with the Pierre Auger Observatory.

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505±22(stat)(-36)(+28)(syst)] mb is found.

Psychosocial and biological predictors of resident physician burnout.

BACKGROUND: A high proportion of health professionals in training suffer from work-related stress and may develop a burnout syndrome. OBJECTIVES: To study the incidence of burnout after the first year of residency in a teaching hospital and to identify baseline psychological, psychosocial work conditions, and biological risk factors. METHODOLOGY: We assessed the following in a prospective cohort of residents at baseline (first month residence) and after 1 year: background factors (socio-demographics, psychiatric history), perceived stress score (Perceived Stress Scale), Maslach Burnout Inventory score, and psychosocial factors (Job Content Questionnaire). Blood samples were obtained to study serum cortisol, IL-6, and TNF-α concentrations. The cumulative incidence was modelled by multivariate log-binomial regression analysis. RESULTS: We included 71 participants with a female majority (64.8%), age 26.4 (2.65) years, psychiatric history in 20%, and burnout in 13%. Among those without burnout initially (N = 59), it had developed by 1 year in 22% of residents. Increased job demand (RR = 1.259, 95%CI = 1.019-1.556, p = 0.033) and decreased cortisol levels (RR = 0.877, 95%CI = 0.778-0.989, p = 0.032) predicted burnout after 1 year of residency among medical trainees. CONCLUSION: Burnout syndrome develops in 22% of residents by 1 year of training and can be predicted by increased work demands and decreased cortisol levels.

C7 deficiency and meningococcal infection susceptibility in two spanish families.

In this work, we report the genetic basis of C7 deficiency in two different Spanish families. In family 1, by using exon-specific polymerase chain reaction and sequencing, a recently described mutation was found in homozygosity in the patient; a single base change in exon 15 (C2107T) leading to a stop codon that causes truncation of the C-terminal portion of C7 (Q681X). Patient's father, mother and sister were heterozygous for this mutation. Interestingly, patient's parents were not related. In family 2, a new single base mutation in exon 2 (G90A), leading to a stop codon that causes the premature truncation of C7 (W8X), was found in the patient, mother and sister 1. Additionally, patient 2, her father and sisters, displayed a missense mutation in exon 9 (G1135C) resulting in a change of aminoacid (G357R). Although sister 1 bore the same mutations in the C7 gene that patient 2, she remains asymptomatic. Because both mutations were found in the patient and her sister, we analyse other defence mechanisms such as FcgammaR polymorphisms as well as mannose-binding lectin alleles (MBL2 gene) and MBL levels. Results showed that both siblings bore identical combinations of FcgammaR allotypes and different MBL2 alleles, exhibiting patient 2 a MBL-insufficient genotype. Normal MBL levels were found in patient 1 and in two previously studied C7-deficient siblings, suggesting the involvement of other mechanisms of immunity distinct of FcgammaR variants and the MBL pathway, for the absence of meningococcal recurrent infections in certain C7-deficient individuals.

Measurement of the depth of maximum of extensive air showers above 10{18} eV.

We describe the measurement of the depth of maximum, X{max}, of the longitudinal development of air showers induced by cosmic rays. Almost 4000 events above 10;{18} eV observed by the fluorescence detector of the Pierre Auger Observatory in coincidence with at least one surface detector station are selected for the analysis. The average shower maximum was found to evolve with energy at a rate of (106{-21}{+35}) g/cm{2}/decade below 10{18.24+/-0.05} eV, and (24+/-3) g/cm{2}/decade above this energy. The measured shower-to-shower fluctuations decrease from about 55 to 26 g/cm{2}. The interpretation of these results in terms of the cosmic ray mass composition is briefly discussed.

Free D-amino acids determination in ready-to-eat cooked ham irradiated with electron-beam by indirect chiral HPLC.

Potential racemization of L-amino acids (AA) in ready-to-eat (RTE) cooked ham after hygienization by electron-beam irradiation between 1 and 8kGy was studied. An indirect chiral method based on the derivatization reaction of AA with o-phthaldialdehyde and N-acetyl-L-cysteine followed by reversed-phase HPLC and fluorimetric detection was applied to detect ten enantiomeric pairs of free AA (Asp, Ser, Thr, Ala, Tyr, Val, Trp, Phe and Leu). Five of the D-AA were not found in any of the samples analyzed; the other five remaining D-AA (D-Asp, D-Ser, D-Ala, D-Val and D-Leu) were detected both in irradiated and non-irradiated cooked ham samples, their content being in the range 1.25-13.79µg/g. Although significant differences appeared for a few of the samples and doses, no positive correlation between the D-AA content and the irradiation doses was observed. Therefore, the electron-beam irradiation technique could be useful for sanitation of packed RTE cooked ham at doses allowed by WHO and EU, since it remains chemically safe to eat.

[Either calcium carbonate or sevelamer decreases urinary oxalate excretion in chronic renal failure patients]. / Carbonato cálcico o sevelamer reducen la excreción urinaria de oxalato en pacientes con insuficiencia renal avanzada.

The rate of oxalate absorbed from intestine is highly influenced by calcium intake in healthy subjects. It is unknown whether commonly used phosphate binders modify intestinal absorption and renal excretion of oxalate in chronic kidney disease (CKD) patients. This study aims to determine if calcium carbonate or sevelamer influences on urinary oxalate excretion. Twenty patients with CKD (stage 4 and 5 pre-dialysis) were included. Two treatment (1500 mg of calcium carbonate or 2400 mg of sevelamer), two-period (21 days each), crossover study with balanced assignment of the order of administration, and two washout periods were the main characteristics of this study design. Laboratory analyses in each phase included: serum creatinine, calcium, phosphorus, bicarbonate, total cholesterol, and 24 h urinary excretion of oxalate, creatinine, and urea. Creatinine clearance, protein catabolic rate (PNNA), total urinary oxalate excretion, and urinary oxalate / creatinine ratio were determined. Seventeen patients completed both treatment sequences. Total urinary oxalate excretion and urinary oxalate / creatinine ratios decreased significantly with respect to washout periods either after sevelamer or calcium carbonate treatment. The decrease in urinary oxalate excretion was greater after calcium carbonate (41.2+/-17.4%) than after sevelamer treatment (30.4+/-23.8%). There were not significant changes in renal function or PNNA values throughout the study periods. In conclusion, either calcium carbonate or sevelamer significantly reduces urinary oxalate excretion in CKD patients. Further studies will be needed to ascertain whether the type of phosphate binder influences on the accumulation of oxalate in CKD patients.

Evolution of suboptimal renal transplantations: experience of a single Spanish center.

The increase in patients on dialysis awaiting transplantation has led to the use of grafts from suboptimal donors. The aim of this study was to analyze the function of suboptimal grafts. The secondary objectives were to study vascular and urological complications, as well as delayed renal function and acute rejection episodes. The study included 135 transplantations performed over 4 years with 27% of grafts being from suboptimal donors. Early graft loss was 12%, of which 69% were due to vascular thrombosis. These thromboses were more frequent among grafts from suboptimal donors (30% vs 4%, P < .001). There were no significant differences between the groups in the incidence of acute rejection episodes (17% vs 13%) or delayed graft function (14% vs 13%). A greater incidence of urologic complications was observed among recipients of grafts from older donors. The 1-year creatinine clearance was significantly lower among recipients of grafts from older donors (73 +/- 19 vs 51 +/- 14 mL/min, P < .0001). Sequential immunosuppressive therapy resulted in a lack of significant differences in creatinine clearance at 6 months, 1 year, or 2 years after transplantation between suboptimal grafts with cold ischemia greater or less than 20 hours or in warm ischemia greater or less than 60 minutes. Logistic regression analysis showed that the best determinant of graft loss was donor age older than 60 years. Accordingly, grafts from suboptimal donors were more likely to be lost during the first month after transplantation, particularly because of thrombosis, which was not due to a higher degree of technical complexity of the transplant operation.

Indirect chiral HPLC determination and fluorimetric detection of D-amino acids in milk and oyster samples.

The indirect chiral method, based on the o-phthaldialdehyde reaction using the chiral N-acetyl-L-cysteine reagent, has been optimized to determine D-amino acids in milk and oyster samples. Both the derivatization reaction and the HPLC separation have been improved, and simple sample treatments were proposed. The milk sample preparation involved centrifugation and filtration through polytetrafluoroethylene filters for determination of free D-AA. Two methods, nonenzymatic and enzymatic, were applied to determination of free and total D-AA, respectively, in oyster samples. The D-AA contents were in the range of 0.14 to 4.32 mg/L for milk samples and 0.80 to 15.9 mg/g for oyster samples, with relative standard deviations lower than 10% (n = 4), except for D-Tyr. In general, mean recoveries were greater than 90% with relative standard deviations lower than 9% (n = 4) at concentration levels from 0.055 to 0.426 mg/L for milk samples and 0.348 to 1.10 mg/ g for oyster samples.

[Accuracy of indirect estimates of renal function in advanced chronic renal failure patients]. / Exactitud de las estimaciones indirectas del filtrado glomerular en la insuficiencia renal avanzada.

Cockcroft-Gault (CG) and Modification of Diet in Renal Disease (MDRD) formula are indirect estimates of renal function which have been widely accepted, though their accuracies have been scarcely validated in advanced chronic renal failure. The purpose of this study was to determine the accuracy (bias and precision) of these formulas in advanced CRF patients. The study group consisted of 99 unselected patients (62 +/- 15 years, 59 females) with advanced CRF. The glomerular filtration rate (GFR) was measured by Tc(99m) DTPA. Simultaneously, estimates of GFR by CG corrected for 1.73 m2 and MDRD (formula 7) were calculated. Agreement was evaluated graphically, bias was assessed by mean and median difference, and precision by median absolute differences and Bland-Altman plots. Mean GFR by DTPA, CG and MDRD were: 16.24 +/- 4.38 and 16.77 +/- 4.65 and 13.58 +/- 4.27 ml/min/1.73 m2, respectively. MDRD equation significantly underestimated GFR-DTPA (p = 0.0001). Both CG and MDRD correlated significantly with GFR-DTPA (R = 0.53 and R = 0.62, respectively). CG formula performed better than the MDRD equation with respect to bias (0.30 vs -3.24 ml/min/1.73 m2, p = 0.0001), and precision (0.58 vs. -3.11 ml/min/1.73 m2, p = 0.0001). By multiple linear regression, the best determinants of the error of the estimation by CC formula were: serum creatinine (beta = -0.58; p < 0.0001), age (beta = -0.62; p < 0.0001), and body mass index (beta = 0.26, p = 0.004), and by MDRD formula were: serum creatinine (beta = -0.38; p < 0.0001), and body mass index (beta = -0.20, p = 0.03). In conclusion, in unselected patients with advanced chronic renal failure, estimates by CC formula were more accurate than those obtained by MDRD formula. Serum creatinine was the main source of error of the estimation of GFR by both formulas, though demographic and anthropometric characteristics influenced as well on their accuracies.

[Cystatin C as estimator of glomerular filtration rate in patients with advanced chronic renal disease]. / Cistatina C como estimador de la función renal en estadios avanzados de enfermedad renal crónica.

Serum cystatin C (CysC) has been shown to be more accurate than serum creatinine (Cr) in estimating renal function, especially in patients with mildmoderate chronic renal failure. However, it is unknown whether CysC provides or not any advantage over Cr in severe chronic renal failure. The aim of this study was to establish the accuracy of CysC in estimating the glomerular filtration rate (GFR) in advanced chronic renal failure patients. The study group consisted of 94 patients (57 females, mean age 61 +/- 16 years) with advanced chronic renal failure. None of them had thyroid dysfunction or was on corticoid treatment. CFR was measured by TC99mDTPA, and simultaneously, serum CysC (particle enhanced immunonephelometry) and Cr (modified Jaffe's kinetic reaction) were also determined. Serum Cr and CysC levels were correlated with GFR, and the influences of age, sex and diabetes on these correlations were analyzed. The predictive value of CysC and Cr to estimate a GFR less than 15 ml/min/1.73 m2 was analyzed by measuring the crea-under-the-curve (AUC) with Receiver-Operating Characteristics (ROC) plots. The mean CFR was 16.49 +/- 4.65 ml/min/1.73 m2. The mean concentrations of Cr and CysC were 4.19 +/- 1.19 mg/L and 3.44 +/- 0.73 mg/L, respectively. Both Cr and CysC correlated significantly with GFR (R = 0.49, p < 0.0001 and R = 0.52, p < 0.0001, respectively). Age and sex influenced on the correlation between Cr and GFR, but these demographic characteristics did not influence on the correlation between CysC and GFR. The AUC for the prediction of a GFR less than 15 ml/min/1.73 m2 with serum Cr was 0.675 (p = 0.004), while with CysC was 0.633 (p = 0.030). In conclusion, both serum Cr and CysC are highly inaccurate markers of renal function in advanced chronic renal failure patients.

A Mn(iii) single ion magnet with tridentate Schiff-base ligands.

Single ion magnet behaviour is reported for a mononuclear Mn(iii) ion with tridentate Schiff-base ligands which exhibits a tetragonal Jahn-Teller elongation along the Namine-Mn-Namine axis and crystallises with two crystallographically distinct Mn(iii) cations (unit A and unit B). While magnetic measurements show a large and negative axial zero-field splitting (D = -4.73 cm(-1)), HF-EPR reveal two distinct large axial Ds (D = -4.60 cm(-1) for unit A and D = -4.18 cm(-1) for unit B), thus resulting in the largest D known to date for a Mn(iii) single ion magnet. AC magnetic measurements at 2000 Oe allowed determination of the energy barrier for spin reversal (10.19 K) and spin reversal relaxation time (1.476 × 10(-6) s) for the Mn(iii) ion. Computational studies were used to characterise the electronic structure and substantiate the zero field splitting in the Mn(iii) complex.

[Serum uric acid and C-reactive protein levels in patients with chronic kidney disease]. / Niveles de ácido úrico y proteína C reactiva en pacientes con insuficiencia renal crónica.

Either inflammation or hyperuricemia has been related with increased cardiovascular risk and mortality. A hypothetical relationship between serum uric acid levels (SUA) and inflammatory markers has never been tested in chronic kidney disease (CKD) patients. The purpose of this study was to determine the prevalence of increased C-reactive protein (CRP) levels in CKD patients, and to test the hypothesis of a relationship between SUA and CRP levels. The study group consisted of 337 patients (174 males, mean age 63 +/- 16 years) with advanced chronic renal failure not yet on dialysis. None of them had overt inflammatory or infectious diseases. High sensitivity CRP levels were analyzed as a binary (above or below median value), or continuous variable (log-transformed CRP), by multiple logistic or linear regression analysis, respectively. Demographics, clinical, and biochemical characteristics, including SUA levels, were the variables tested in these analysis. In a subset of 169 patients without diabetes, the same analysis were carried out, with the inclusion of fasting insulin levels and HOMA-IR as independent variables. Median CRP level was 3.25 mg/L, and mean SUA level was 7.59 +/- 1.94 mg/dl. Patients with CRP levels above the median had significantly higher mean SUA level than that of the rest of study patients (7.93 +/- 1.79 vs 7.24 +/- 2.03 mg/dl, p = 0.001). SUA levels correlated significantly with log-transformed CRP levels (r = 0. 16, p = 0.0022). The relationship between SUA and CRP levels remained statistically significant after adjustment for age, sex, comorbid index, obesity, residual renal function, diuretic and allopurinol treatment, in the multivariate logistic and linear regression models (OR: 1.296, p = 0.0003; and beta: 0.204, p = 0.0002). The significant association between SUA and CRP levels did not change when HOMA-IR and fasting insulin levels were included as independent variables in the subset of 169 patients without diabetes. In conclusion, SUA levels are related with CRP levels in CKD patients.

Impaired G protein coupling of the neurotensin receptor 1 by mutations in extracellular loop 3.

The neurotensin receptor 1, NTS1, is a G protein-coupled receptor. We have shown previously that the NTS1 receptor-binding site of the peptide agonist involved residues in extracellular loop 3 and at the extracellular junction of transmembrane domains 4 and 6. Here, we investigated by site-directed mutagenesis residues in extracellular loop 3 that might be involved in agonist-induced activation of the rat NTS1 (rNTS1) receptor. Wild type and mutated receptors were expressed in COS (African green monkey kidney fibroblasts) cells. Labeled agonist and antagonist binding as well as inositol phosphate and cAMP productions were studied. Compared to the wild type NTS1 receptor, the W339A, F344A, H348A and Y349A mutant receptors exhibited (i) decreased proportion of high over low affinity agonist binding sites, (ii) increased sensitivity of high affinity agonist binding to GTP gamma S, and (iii) impaired G protein coupling of high affinity agonist-receptor complexes. The data are consistent with the C-terminal part of extracellular loop 3 being essential for allowing high affinity agonist-NTS1 receptor complexes to couple to G proteins.

Refractive Error Study in Children: results from La Florida, Chile.

PURPOSE: To assess the prevalence of refractive errors and vision impairment in school-age children in a suburban area (La Florida) of Santiago, Chile. METHODS: Random selection of geographically defined clusters was used to identify a representative sample of children 5 to 15 years of age. Children in the 26 selected clusters were enumerated through a door-to-door survey and invited to report to a community health clinic for examination. Visual acuity measurements, cycloplegic retinoscopy, cycloplegic autorefraction, ocular motility evaluation, and examination of the external eye, anterior segment, media, and fundus were done from April through August 1998. Independent replicate examinations of all children with reduced vision and a sample of those with normal vision were done for quality assurance monitoring in six clusters. RESULTS: A total of 6,998 children from 3,830 households were enumerated, and 5,303 children (75.8%) were examined. The prevalence of uncorrected, presenting, and best visual acuity 0.50 (20/40) or worse in at least one eye was 15.8%, 14.7%, and 7.4%, respectively; 3.3% had best visual acuity 0.50 or worse in both eyes. Refractive error was the cause in 56.3% of the 1,285 eyes with reduced vision, amblyopia in 6.5%, other causes in 4.3%, with unexplained causes in the remaining 32.9%. Myopia -0.50 diopter or less in either eye was present in 3.4% of 5-year-old children, increasing to 19.4% in males and 14.7% in females by age 15. Over this same age range, hyperopia 2.00 diopters or greater decreased from 22.7% to 7.1% in males and from 26.3% to 8.9% in females. Females had a significantly higher risk of hyperopia than males. CONCLUSIONS: Refractive error, associated primarily with myopia, is a major cause of reduced vision in school-age children in La Florida. More than 7% of children could benefit from the provision of proper spectacles. Efforts are needed to make existing programs that provide free spectacles for school children more effective. Further studies are needed to determine whether the upward trend in myopia continues far beyond 15 years of age.

Stability studies of carbamate pesticides and analysis by gas chromatography with flame ionization and nitrogen-phosphorus detection.

As a result of thermal stability studies of carbamate pesticides, a method has been proposed for their direct determination by gas chromatography in the ranges 1-20 and 0.1-1 mg l(-1), using flame ionization and nitrogen-phosphorus detection, respectively. The method allows the determination of propham, propoxur, carbofuran, carbaryl, methiocarb, isopropoxyphenol and naphthol in powdered potato samples. The analytes were previously extracted with a light petroleum-dichloromethane (1:1, v/v) mixture and preconcentred by solid-phase extraction through a C8 cartridge. The recoveries obtained from spiked potato samples (n=4 replicates) at two concentration levels, 10 and 0.5 mg of pesticide per kg of sample, were in the ranges 72-115 and 50-73%, with relative standard deviations of 2-7 and 5-8%, respectively. The detection limits were 50-210 and 41-53 microg kg(-1) with flame ionization and nitrogen-phosphorus detection, respectively, and reaching the maximum residue levels, 0.05 mg kg(-1) for methiocarb and propoxur, set by the Real Decreto 280/1994 (based on the European directive).

Direct determination of monolinuron, linuron and chlorbromuron residues in potato samples by gas chromatography with nitrogen-phosphorus detection.

A gas chromatography with nitrogen-phosphorus detection direct method for methoxyurea herbicide determination in powdered potato and fresh potato samples has been developed. A previous study of the thermal stability of the phenylurea herbicides seems to confirm that the ones containing the methoxy radical, i.e. monolinuron, linuron and chlorbromuron, were stable. The herbicides were extracted from the sample through liquid-liquid extraction with dichloromethane-light petroleum (1:1), followed by solid-phase extraction in a C8 cartridge. The recoveries were in the range 84-95% for powdered potato and 86-101% for fresh potato. The RSD values were less than 10%, at 0.1 microg g(-1) concentration level (n = 4) for both types of samples. Detection limits of the method were 7.0-30 ng g(-1) for powdered potato and 6.0-50 ng g(-1) for fresh potato.

[Obesity and mortality in advanced chronic renal failure patients]. / Obesidad y mortalidad en pacientes con insuficiencia renal avanzada.

A protective effect of obesity on the mortality of end-stage renal failure patients has been observed in several studies. Most of these studies have been based on prevalent dialysis population. The aim of the present study was to evaluate if obesity has beneficial effects on the survival of advanced chronic renal failure patients. The study group consisted of 376 patients (mean age 63 +/- 15 years) with advanced chronic renal failure not yet on dialysis. Obesity was defined as a body mass index (BMI) > or = 30 kg/m2. Grade of comorbidity was quantified by the method devised by Davies. Survival was analyzed as time from the referral to the predialysis outpatient clinic to patient death, censoring from contributing additional survival data to the analysis following transplantation. Kaplan-Meier analysis was used to test survival differences according to quartiles of BMI, and between obese and nonobese patients. Further analysis were performed, stratifying survival curves by comorbid scores, lean body mass, age, and sex. Cox proportional hazard regression models were used to investigate the best determinants of mortality, and the role of obesity adjusted for other covariates. Median survival time was 1,453 days. During the follow-up time, 158 patients (42%) died. Survival differences among quartiles of BMI were statistically significant (Breslow = 10.7, p = 0.017). Patients within the lowest and the highest quartiles of BMI had higher mortality than the rest of patients. Survival curves between obese and non-obese patients did not differ significantly. However, when patients without comorbidity were studied apart, those with obesity showed worse survival than the rest of patients (log-rank = 7.42, p = 0.0064). Since the effect of obesity on mortality did not follow a proportional hazard pattern throughout the study period, multivariable analysis for mortality was stratified by 18 months intervals. The variables which fitted the best model were: age (Hazard Ratio: 1.04), comorbid score (HR: 2.17), serum albumin (HR: 0.62), GFR at the study entry (HR: 0.91), male gender (HR: 1.48), and obesity (HR: 1.51). In conclusion, obesity had no survival benefit in patients with advanced chronic renal failure. Obesity had a noteworthy impact on early mortality of advanced chronic kidney disease patients without comorbidities.

[Ultrasonography in diagnosis and monitoring the progress of dissection of cervicocerebral arteries]. / La ecografía en el diagnóstico y control evolutivo de las disecciones de arterias cervicocerebrales.

INTRODUCTION: Ultrasonography has become part of the arsenal of diagnostic methods available for examining the dissection of cerebral blood vessels (DCV). AIMS: To analyse the value of ultrasonography in the diagnosis and monitoring of DCV. PATIENTS AND METHODS: We conducted a consecutive study of 67 patients with a history and clinical picture compatible with DCV; all of them had been given confirmation of their diagnosis by another reference method (digital angiography or MR angiography) during the 48 hours prior to or following the ultrasound study. The ultrasonography was carried out on the neck and skull as per the usual system using continuous Doppler, neck duplex and transcranial Doppler ultrasonography. Diagnosis of the dissection was based on direct and indirect signs, in the absence of an atheroma plaque. The following were considered to be direct signs: haematoma in the wall of the vessel, flap, local increase in the flow velocity and echograms with split systole. Indirect signs were: haemodynamic alterations proximal to the dissection, a pattern of slow flow and high resistance. The transcranial Doppler showed the findings lying distal to the dissection to be a lowered mean velocity and pulsatility. RESULTS: The ultrasonography of the series revealed direct signs in 46 patients (69%) and indirect signs in 21 (31%). Ultrasonography was used as the primary diagnostic method in 29 (43%) patients; in the other 38 (57%) it was employed to verify the diagnosis or for the follow up. All the ultrasound diagnoses were confirmed using digital angiography (21 cases) or magnetic resonance angiography (46 cases). CONCLUSIONS: Due to its harmlessness, ultrasonography should be the first examination used to establish a probable diagnosis of DCV.