Is Decreased Xylem Sap Surface Tension Associated With Embolism and Loss of Xylem Hydraulic Conductivity in Pathogen-Infected Norway Spruce Saplings?

Increased abiotic stress along with increasing temperatures, dry periods and forest disturbances may favor biotic stressors such as simultaneous invasion of bark beetle and ophiostomatoid fungi. It is not fully understood how tree desiccation is associated with colonization of sapwood by fungi. A decrease in xylem sap surface tension (sigma(xylem)) as a result of infection has been hypothesized to cause xylem embolism by lowering the threshold for air-seeding at the pits between conduits and disruptions in tree water transport. However, this hypothesis has not yet been tested. We investigated tree water relations by measuring the stem xylem hydraulic conductivity (K-stem), sigma(xylem), stem relative water content (RWCstem), and water potential (psi(stem)), and canopy conductance (g(canopy)), as well as the compound composition in xylem sap in Norway spruce (Picea abies) saplings. We conducted our measurements at the later stage ofEndoconidiophora polonicainfection when visible symptoms had occurred in xylem. Saplings of two clones (44 trees altogether) were allocated to treatments of inoculated, wounded control and intact control trees in a greenhouse. The saplings were destructively sampled every second week during summer 2016. sigma(xylem), K(stem)and RWC(stem)decreased following the inoculation, which may indicate that decreased sigma(xylem)resulted in increased embolism. g(canopy)did not differ between treatments indicating that stomata responded to psi(stem)rather than to embolism formation. Concentrations of quinic acid, myo-inositol, sucrose and alkylphenol increased in the xylem sap of inoculated trees. Myo-inositol concentrations also correlated negatively with sigma(xylem)and K-stem. Our study is a preliminary investigation of the role of sigma(xylem)inE. polonicainfected trees based on previous hypotheses. The results suggest thatE. polonicainfection can lead to a simultaneous decrease in xylem sap surface tension and a decline in tree hydraulic conductivity, thus hampering tree water transport.Peer reviewe

Is Decreased Xylem Sap Surface Tension Associated With Embolism and Loss of Xylem Hydraulic Conductivity in Pathogen-Infected Norway Spruce Saplings?

Increased abiotic stress along with increasing temperatures, dry periods and forest disturbances may favor biotic stressors such as simultaneous invasion of bark beetle and ophiostomatoid fungi. It is not fully understood how tree desiccation is associated with colonization of sapwood by fungi. A decrease in xylem sap surface tension (sigma(xylem)) as a result of infection has been hypothesized to cause xylem embolism by lowering the threshold for air-seeding at the pits between conduits and disruptions in tree water transport. However, this hypothesis has not yet been tested. We investigated tree water relations by measuring the stem xylem hydraulic conductivity (K-stem), sigma(xylem), stem relative water content (RWCstem), and water potential (psi(stem)), and canopy conductance (g(canopy)), as well as the compound composition in xylem sap in Norway spruce (Picea abies) saplings. We conducted our measurements at the later stage ofEndoconidiophora polonicainfection when visible symptoms had occurred in xylem. Saplings of two clones (44 trees altogether) were allocated to treatments of inoculated, wounded control and intact control trees in a greenhouse. The saplings were destructively sampled every second week during summer 2016. sigma(xylem), K(stem)and RWC(stem)decreased following the inoculation, which may indicate that decreased sigma(xylem)resulted in increased embolism. g(canopy)did not differ between treatments indicating that stomata responded to psi(stem)rather than to embolism formation. Concentrations of quinic acid, myo-inositol, sucrose and alkylphenol increased in the xylem sap of inoculated trees. Myo-inositol concentrations also correlated negatively with sigma(xylem)and K-stem. Our study is a preliminary investigation of the role of sigma(xylem)inE. polonicainfected trees based on previous hypotheses. The results suggest thatE. polonicainfection can lead to a simultaneous decrease in xylem sap surface tension and a decline in tree hydraulic conductivity, thus hampering tree water transport.Peer reviewe

Normal growth and intravascular volume status with good metabolic control during peritoneal dialysis in infancy

Peer reviewe

Global Variation of Nutritional Status in Children Undergoing Chronic Peritoneal Dialysis : A Longitudinal Study of the International Pediatric Peritoneal Dialysis Network

While children approaching end-stage kidney disease (ESKD) are considered at risk of uremic anorexia and underweight they are also exposed to the global obesity epidemic. We sought to investigate the variation of nutritional status in children undergoing chronic peritoneal dialysis (CPD) around the globe. The distribution and course of body mass index (BMI) standard deviation score over time was examined prospectively in 1001 children and adolescents from 35 countries starting CPD who were followed in the International Pediatric PD Network (IPPN) Registry. The overall prevalence of underweight, and overweight/obesity at start of CPD was 8.9% and 19.7%, respectively. Underweight was most prevalent in South and Southeast Asia (20%), Central Europe (16.7%) and Turkey (15.2%), whereas overweight and obesity were most common in the Middle East (40%) and the US (33%). BMI SDS at PD initiation was associated positively with current eGFR and gastrostomy feeding prior to PD start. Over the course of PD BMI SDS tended to increase on CPD in underweight and normal weight children, whereas it decreased in initially overweight patients. In infancy, mortality risk was amplified by obesity, whereas in older children mortality was markedly increased in association with underweight. Both underweight and overweight are prevalent in pediatric ESKD, with the prevalence varying across the globe. Late dialysis start is associated with underweight, while enteral feeding can lead to obesity. Nutritional abnormalities tend to attenuate with time on dialysis. Mortality risk appears increased with obesity in infants and with underweight in older children.Peer reviewe

Management of children with congenital nephrotic syndrome: challenging treatment paradigms

WOS: 000493307500019PubMed ID: 30215773Background. Management of children with congenital nephrotic syndrome (CNS) is challenging. Bilateral nephrectomies followed by dialysis and transplantation are practiced in most centres, but conservative treatment may also be effective. Methods. We conducted a 6-year review across members of the European Society for Paediatric Nephrology Dialysis Working Group to compare management strategies and their outcomes in children with CNS. Results. Eighty children (50% male) across 17 tertiary nephrology units in Europe were included (mutations in NPHS1, n = 55; NPHS2, n = 1; WT1, n = 9; others, n = 15). Excluding patients with mutations in WT1, antiproteinuric treatment was given in 42 (59%) with an increase in S-albumin in 70% by median 6 (interquartile range: 3-8) g/L (P< 0.001). Following unilateral nephrectomy, S-albumin increased by 4 (1-8) g/L (P = 0.03) with a reduction in albumin infusion dose by 5 (2-9) g/kg/week (P = 0.02). Median age at bilateral nephrectomies (n = 29) was 9 (7-16) months. Outcomes were compared between two groups of NPHS1 patients: those who underwent bilateral nephrectomies (n = 25) versus those on conservative management (n = 17). The number of septic or thrombotic episodes and growth were comparable between the groups. The response to antiproteinuric treatment, as well as renal and patient survival, was independent of NPHS1 mutation type. At final follow-up (median age 34months) 20 (80%) children in the nephrectomy group were transplanted and 1 died. In the conservative group, 9 (53%) remained without dialysis, 4 (24%; P< 0.001) were transplanted and 2 died. Conclusion. An individualized, stepwise approach with prolonged conservative management may be a reasonable alternative to early bilateral nephrectomies and dialysis in children with CNS and NPHS1 mutations. Further prospective studies are needed to define indications for unilateral nephrectomy.National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust and University College, London; National Institute for Health Research (NIHR)National Institute for Health Research (NIHR)This work was supported by the National Institute for Health Research Biomedical Research Centre at Great Ormond Street Hospital for Children National Health Service (NHS) Foundation Trust and University College, London. R.S. holds a Career Development Fellowship with the National Institute for Health Research (NIHR)

Genetic aspects of congenital nephrotic syndrome: a consensus statement from the ERKNet-ESPN inherited glomerulopathy working group

Congenital nephrotic syndrome (CNS) is a heterogeneous group of disorders presenting with massive proteinuria within the first 3 months of life almost inevitably leading to end-stage kidney disease. The Work Group for the European Reference Network for Kidney Diseases (ERKNet) and the European Society for Pediatric Nephrology (ESPN) has developed consensus statement on genetic aspects of CNS diagnosis and management. The presented expert opinion recommends genetic diagnostics as the key diagnostic test to be ordered already during the initial evaluation of the patient, discusses which phenotyping workup should be performed and presents known genotype-phenotype correlations.status: publishe

Pleural-peritoneal or pericardio-peritoneal leak in children on chronic peritoneal dialysis : a survey from the European Paediatric Dialysis Working Group

Pleural or pericardial effusions secondary to pleuro-peritoneal fistula (PPF) and pericardio-peritoneal fistula (PcPF) are rare but serious complications of peritoneal dialysis (PD). We conducted a 10-year survey across all participating centres in the European Paediatric Dialysis Working Group to review the incidence, diagnostic techniques, therapeutic options and outcome of children on chronic PD with PPF and/or PcPF. Of 1506 children on PD there were ten cases (8 of PPF, 1 each of PcPF and PPF + PcPF), with a prevalence of 0.66 %. The median age at presentation was 1.5 [inter-quartile range (IQR) 0.4-2.4] years, and nine children were < 3 years. The time on PD before onset of symptoms was 4.3 (IQR 1.3-19.8) months. Eight children had herniae and seven had abdominal surgery in the preceding 4 weeks. Symptoms at presentation were respiratory distress, reduced ultrafiltration and tachycardia. PD was stopped in all children; three were managed conservatively and thoracocentesis was performed in seven (with pleurodesis in 3). PD was restarted in only three children, in two of them with success. In conclusion, PPF and PcPF are rare in children on chronic PD, but are associated with significant morbidity, requiring a change of dialysis modality in all cases. Risk factors for PPF development include age of < 3 years, herniae and recent abdominal surgery

Indications, technique, and outcome of therapeutic apheresis in European pediatric nephrology units

Few observations on apheresis in pediatric nephrology units have been published. This retrospective study involved children a parts per thousand currency sign18 years undergoing plasma exchange (PE), immunoadsorption (IA), or double filtration plasmapheresis (DFPP) in 12 European pediatric nephrology units during 2012. Sixty-seven children underwent PE, ten IA, and three DFPP, for a total of 738 PE and 349 IA/DFPP sessions; 67.2 % of PE and 69.2 % of IA/DFPP patients were treated for renal diseases, in particular focal segmental glomerulosclerosis (FSGS), hemolytic-uremic syndrome (HUS), and human leukocyte antigen (HLA) desensitization prior to renal transplantation; 20.9 % of PE and 23.1 % of IA/DFPP patients had neurological diseases. Membrane filtration was the most common technique, albumin the most frequently used substitution fluid, and heparin the preferred anticoagulant. PE achieved full disease remission in 25 patients (37.3 %), partial remission in 22 (32.8 %), and had no effect in 20 (29.9 %). The response to IA/DFPP was complete in seven patients (53.8 %), partial in five (38.5 %), and absent in one (7.7 %). Minor adverse events occurred during 6.9 % of PE and 9.7 % of IA/DFPP sessions. PE, IA, and DFPP are safe apheresis methods in children. Efficacy is high in pediatric patients with recurrent focal segmental glomerulosclerosis (FSGS), atypical hemolytic uremic syndrome (HUS), human leukocyte antigen (HLA) sensitization, and neurological autoimmune diseases

Encapsulating peritoneal sclerosis in children on chronic PD: a survey from the European Paediatric Dialysis Working Group

Background. Encapsulating peritoneal sclerosis (EPS) is a rare complication of peritoneal dialysis (PD) that is associated with significant morbidity and mortality in adults. There are scarce data for children. We performed a 10-year survey to determine the prevalence, risk factors and outcome for EPS in children. Methods. Chronic PD patients in 14 dialysis units participating in the European Paediatric Dialysis Working Group between January 2001 and December 2010 were included in this study. Results. Twenty-two cases of EPS were reported (prevalence 1.5%; 8.7 per 1000 patient-years on PD). Median PD vintage was 5.9 (1.6-10.2) in EPS and 1.7 (0.7-7.7) years in the remainder of the PD population (P < 0.0001). EPS patients had a significantly higher peritonitis rate than non-EPS patients (P = 0.2). EPS was diagnosed while the child was on PD in 17 (77%), after conversion to haemodialysis (HD) in 3 and after transplantation in 2. Fifteen of 17 (88%) developed ultrafiltration (UF) failure. The median interval between UF failure and presentation with bowel obstruction was 2.8 (0.02-5.8) months. Twenty (91%) had clinical and radiological signs of bowel obstruction. Enterolysis was performed in 14 and 19 received immunosuppression or tamoxifen. Nine required parenteral nutrition. At final follow-up 4.8 (1.3-8.7) years after EPS diagnosis, 3 patients died, 11 had a functioning transplant and 8 were on HD. Conclusions. The prevalence of EPS in European children on PD is comparable with that of adult PD patients, but mortality from paediatric EPS is significantly lower. A high index of suspicion is required for the diagnosis of EPS in children with longer dialysis duration, a high peritonitis rate and UF failure