In hemodialysis patients, large arteriovenous (AV) fistulas for vascular access may cause ventricular hypertrophy and high-output cardiac failure. The long-term cardiac consequences of functional AV fistulas in renal transplant patients are unclear. A precise knowledge of these consequences is important to decide if and when such fistulas should be closed in successfully transplanted patients. In this retrospective study including 61 stable renal transplant patients with adequate renal function (serum creatinine <2.0 mg/100 ml), echocardiography was performed in 39 patients with a functional AV fistula (group 1) and in 22 whose fistulas had been closed, for esthetic reasons, within 2 months postoperatively (group 2). The volume flow of the fistulas, measured in 22 randomly selected individuals of group 1, was 900 ± 350 ml/min (range 500–1,600). Patients of group 1 were older (40 ± 12 vs. 33 ± 12 years, p < 0.05), had longer duration of the fistula (62 ± 31 vs. 36 ± 30 months, p < 0.05), higher body mass index (24 ± 4 vs. 22 ± 3 kg/m², p < 0.05), systolic (154 ± 24 vs. 138 ± 18 mm Hg, p < 0.05) and diastolic (96 ± 12 vs. 89 ± 11 mm Hg, p < 0.05) blood pressure and increased left ventricular (LV) end-diastolic dimension (53 ± 5 vs. 49 ± 5 mm, p < 0.01). LV mass, cardiac index, ejection fraction and the proportion of patients with LV hypertrophy were comparable in the two groups. LV end-diastolic dimension was positively and independently influenced only by the presence of the AV fistula (p < 0.01) after adjusting for age, duration of the fistula, body mass index, systolic and diastolic blood pressure and the nature of the antihypertensive drugs used. In conclusion, the persistence of large, high-flow AV fistulas for prolonged periods of time had little impact on cardiac morphology and function of stable renal transplant patients with adequate renal function. The data do not support routine closure of these fistulas in all renal transplant patients.

2Currently, the direct detection of Leptospira infection can be done in clinical laboratories by 26 a conventional nested polymerase chain reaction method (nested PCR), which is 27 labourious and time-consuming. To overcome these drawbacks, we tested a set of paired 28 samples of serum and urine from 202 patients presenting at a hospital located in an area 29 endemic for leptospirosis using high resolution melting (HRM). The results were compared 30 with those obtained by nested PCR for direct detection of the pathogen in both specimens 31 and with the gold standard test used for indirect detection of anti-Leptospira antibodies in 32 serum (the microscopic agglutination test, MAT). The HRM assay results were positive for 33 46/202 (22.7%) samples, whereas 47/202 (23.3%) samples were positive by nested PCR. 34 As expected in recently infected febrile patients, MAT results were positive in only 3/46 35 (6.5%) HRM-positive samples. We did a unique comparative analysis using a robust 36 biobank of paired samples of serum and urine from the same patient to validate the HRM 37 assay for molecular diagnosis of human leptospirosis in a clinical setting. This assay fills a 38 void unmet by serologic assays as it can detect the presence of Leptospira in biological 39 samples even before development of antibody takes place.40 41 48 support is essential 3 . Treatment with appropriate antibiotics should be initiated as early as 49 possible after laboratory confirmation; however, the majority of patients suspected to have 50 leptospirosis are treated empirically with broad-spectrum antibiotics effective against most 51 bacteria before a definitive diagnosis is established. At the Hospital of Divino Espírito Santo 52 of Ponta Delgada (HDES), located on São Miguel Island (Azores), Leptospira infection is 53 confirmed in the laboratory by identifying the presence of specific fragments of Leptospira 54 DNA in patient samples (serum and urine) through conventional nested polymerase chain 55 reaction (nested PCR) 4,5 . This method is time-consuming (it takes approximately 5 hours) 56and is sometimes too slow to support the clinical decision for antibiotic therapy. 57Current techniques to detect Leptospira infection are evolving from conventional 58 PCR to real-time PCR, which is faster, tends to have higher sensitivity and specificity at 59 detecting pathogenic Leptospira species and is performed in a closed system that reduces 60 the risk of DNA cross-contamination 6 . An emerging technique for clinical diagnosis is high 61 resolution melting (HRM) analysis. HRM was first described by Carl Wittwer's group for 62 mutation screening 7 , and the underlying principle is the generation of different melting curve 63 profiles due to sequence variations in double-stranded DNA. HRM is typically performed 64 with a real-time PCR instrument immediately after PCR. Advantages of this method include 65 a rapid turn-around time (less than 2hr), a closed-tube format that significantly reduces 66 4 contamination risk, high sensitivity and ...

No abstract