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Research in affective disorders is often performed without considering sex differences, although women are predominantly affected. Consequently, the potential sex-dependent action of antidepressants remains elusive. We investigated whether Flinders sensitive line (FSL) of rats, a model of depression, would present sex-differentiated responses to antidepressant treatment. FSL and Sprague-Dawley rats were treated with clomipramine 10 mg/kg/day for 14 days. Subsequently, they were subjected to either a single session of the forced swim test or an estimation of serotonergic function in the prefrontal cortex, hippocampus, amygdala and hypothalamus. Male FSL displayed increased immobility duration, decreased active behaviours, increased serotonin tissue levels and a reduced serotonin turnover rate in most brain areas studied. Female FSL showed a distinct profile, consisting of decreased immobility latency, increased climbing duration, limited serotonergic deviations and no difference in the serotonin turnover rate in comparison with controls. Interestingly, despite baseline differences, clomipramine treatment reversed all relevant behavioural responses and increased the serotonin turnover rate in both sexes. However, the latter effect was remarkably more pronounced in females. It is concluded that, in this animal model of depression, chronic clomipramine treatment attenuated baseline sex differences in the phenotype while maintaining or intensifying the sex differentiation in the serotonergic endophenotype.

Introduction: The vascular access cannulation technique varies among clinics, and guidelines on vascular access give little importance to cannulation techniques. The objective of this study was to evaluate the cannulation technique and to determine which factors are associated with each detail of the technique. Material and methods: The vascular access cannulation was evaluated in 260 patients undergoing hemodialysis. The type and anatomical location of the vascular access, the cannulation technique, direction, gauge, and distance between needles, besides bevel direction and needle rotation were registered. Results: The arteriovenous fistula was the most frequent vascular access (88%), the most used cannulation technique was area (100%), the needle direction was anterograde in most cases (79.5%), and the mean distance between the tips of needles was 7.57±4.43 cm. For arteriovenous grafts, the proximal anatomical location (brachial artery) and cannulation with 16G needles in anterograde position were more predominant. For arteriovenous fistulas, the distal anatomical location (radial artery) and cannulation through 15G needles were more common. Cannulation of vascular access in retrograde direction was associated with a greater distance between needles (13.2 ± 4.4 vs 6.1 ± 3 cm, p < 0.001). Kt/V was higher when the distance between needles was higher than 5 cm (1.61 ± 0.3 vs. 1.47 ± 0.28, p < 0.01). Conclusions: The vascular access cannulation technique depends on the vascular access characteristics and expertise of cannulators. Clinical trials are required for the formulation of guidelines for vascular access cannulation.

Introduction: Cannulation of arteriovenous fistula (AVF) may be performed by the following techniques: area puncture, rope ladder, or buttonhole. The ideal technique has not yet been established. Objective: To assess the complications and difficulties of introducing the buttonhole (BH) technique for cannulation of AVF created with a native vein in a dialysis unit. Methods: Sixteen patients (mean age, 57 ± 14 years) undergoing hemodialysis for 63 ± 38 months were changed to BH AVF cannulation. In the phase of track formation cannulations were performed with sharp needles and, in the maintenance phase, with blunt needles. In both phases, patients were assessed for pain intensity on a 0 to 10 scale. Results: The number of HD sessions required for the track formation was 9.5 ± 1.5 and the number of sessions during the maintenance phase was 29.7 ± 0.8 per patient. During the 152 HD for the track formation, no significant complications occurred. During the 475 HD sessions using the BH technique and a blunt needle, the complications were as follows: resistance to cannulation (7.6%); cannulation using a sharp needle due to cannulator choice (5.7%); change from a blunt to a sharp needle during cannulation (4.2%); and local bleeding (0.8%). One patient required antibiotic therapy. The median pain intensity reported by the patients was four during the track formation, and two during cannulation with a blunt needle. The Kt/V values before and after changing the cannulation technique did not differ (1.48 ± 0.27 and 1.48 ± 0.23). Conclusion:The introduction of the BH technique with a blunt needle is technically easy, has few complications, reduces pain, and does not induce change in dialysis dose.

Introduction: Malnutrition is a frequent complication in patients on hemodialysis and early diagnosis is important to reduce the morbidity and mortality of treatment. Objective: To investigate the usefulness of biochemical tests performed monthly in order to identify hemodialysis patients with malnutrition. Methods: The nutritional status of 252 patients was evaluated by objective and subjective global assessment, and the patients classified as malnourished and not malnourished. Then, during 4 consecutive months, serum creatinine, phosphorus, urea pre-and post-dialysis and Kt/V were recorded for calculation of averages. After analysis of these variables by the ROC curve we calculated the sensitivity and specificity of these parameters to identify patients with malnutrition. Results: In ROC curve, the area under the curve for urea was 0.683, 0.71 for phosphorus, 0.724 for Kt/V and 0.765 for creatinine. For values of urea ≤ 90 mg/dL, phosphorus ≤ 4.2 mg/dL, Kt/V ≥ 1.6 and creatinine ≤ 6.5 mg/dL, the specificity ranged between 80 and 88% and sensitivity between 26 and 51%. The negative predictive value ranged between 90 and 92% and positive predictive value between 23 and 32%. The association of two or more of these indices did not change significantly these values. Conclusions: Our results suggest that serum urea ≤ 90 mg/dL, creatinine ≤ 6.5 mg/dL, phosphorus ≤ 4.2 mg/dL, and Kt/V ≥ 1.6 can be used for screening patients with malnutrition. However, using these cutoffs the parameters tend to overestimate the number of patients with malnutrition.