Malnutrition: A risk factor for vascular access problems.

BACKGROUND: Vascular access problems are leading causes of morbidity, hospitalization, and impaired quality of life in chronic hemodialysis patients. Native arteriovenous fistula is the gold standard of vascular access. Geriatric nutritional risk index (GNRI), has recently been shown to be an easy and objective instrument for assessing nutritional status in these patient groups. Considering the association between arteria-venous fistula patency and inflammation, as well as the fact that inflammation is a component of malnutrition, the objective of this study was to determine the relation of malnutrition identified by GNRI with fistula patency. METHODS: This is a single-center, retrospective, observational study. Hemodialysis patients with AVF were included in the research. Preoperative and postoperative GNRI values were computed and laboratory data were recorded. The patients were analyzed in two groups as the ones without thrombosis history (Group 1) and with thrombosis history (Group 2). According to GNRI, patients were investigated in four groups: G0 (non-risk group, >98), G1 (low risk, 92-98), G2 (moderate risk, 82-91), and G3 (high risk, 82). RESULTS: Of the 331 patients, 60.1% (199) were male and the average age was 55 ± 15 years. Preoperative GNRI levels were significantly higher in group 1. In correlation analysis, patency time was positively correlated with preoperative GNRI values. Among the preoperative GNRI groups, the G3 group had a patency duration of 6 months (4.9-7.04), whereas the G0 group had a patency length of 37.59 (35.5-39.65) months. By linear regression analysis, preoperative GNRI and postoperative albumin level were determined to be the significant indicators of patency time. CONCLUSION: GNRI a new tool for detecting malnutrition was strongly associated with fistula patency in hemodialysis patients. Detection of malnutrition before fistula operation may be helpful for the future follow up of the patients in terms of fistula patency.

Dorsal Bed Nucleus of the Stria Terminalis-Subcortical Output Circuits Encode Positive Bias in Pavlovian Fear and Reward.

Opposite emotions like fear and reward states often utilize the same brain regions. The bed nucleus of the stria terminalis (BNST) comprises one hub for processing fear and reward processes. However, it remains unknown how dorsal BNST (dBNST) circuits process these antagonistic behaviors. Here, we exploited a combined Pavlovian fear and reward conditioning task that exposed mice to conditioned tone stimuli (CS)s, either paired with sucrose delivery or footshock unconditioned stimuli (US). Pharmacological inactivation identified the dorsal BNST as a crucial element for both fear and reward behavior. Deep brain calcium imaging revealed opposite roles of two distinct dBNST neuronal output pathways to the periaqueductal gray (PAG) or paraventricular hypothalamus (PVH). dBNST neural activity profiles differentially process valence and Pavlovian behavior components: dBNST-PAG neurons encode fear CS, whereas dBNST-PVH neurons encode reward responding. Optogenetic activation of BNST-PVH neurons increased reward seeking, whereas dBNST-PAG neurons attenuated freezing. Thus, dBNST-PVH or dBNST-PAG circuitry encodes oppositely valenced fear and reward states, while simultaneously triggering an overall positive affective response bias (increased reward seeking while reducing fear responses). We speculate that this mechanism amplifies reward responding and suppresses fear responses linked to BNST dysfunction in stress and addictive behaviors.

Klotho Lacks an FGF23-Independent Role in Mineral Homeostasis.

Fibroblast growth factor-23 (FGF23) is a bone-derived hormone regulating vitamin D hormone production and renal handling of minerals by signaling through an FGF receptor/αKlotho (Klotho) receptor complex. Whether Klotho has FGF23-independent effects on mineral homeostasis is a controversial issue. Here, we aimed to shed more light on this controversy by comparing male and female triple knockout mice with simultaneous deficiency in Fgf23 and Klotho and a nonfunctioning vitamin D receptor (VDR) (Fgf23/Klotho/VDR) with double (Fgf23/VDR, Klotho/VDR, and Fgf23/Klotho) and single Fgf23, Klotho, and VDR mutants. As expected, 4-week-old Fgf23, Klotho, and Fgf23/Klotho knockout mice were hypercalcemic and hyperphosphatemic, whereas VDR, Fgf23/VDR, and Klotho/VDR mice on rescue diet were normocalcemic and normophosphatemic. Serum levels of calcium, phosphate, and sodium did not differ between 4-week-old triple Fgf23/Klotho/VDR and double Fgf23/VDR or Klotho/VDR knockout mice. Notably, 3-month-old Fgf23/Klotho/VDR triple knockout mice were indistinguishable from double Fgf23/VDR and Klotho/VDR compound mutants in terms of serum calcium, serum phosphate, serum sodium, and serum PTH, as well as urinary calcium and sodium excretion. Protein expression analysis revealed increased membrane abundance of sodium-phosphate co-transporter 2a (NaPi-2a), and decreased expression of sodium-chloride co-transporter (NCC) and transient receptor potential cation channel subfamily V member 5 (TRPV5) in Fgf23/Klotho/VDR, Fgf23/VDR, and Klotho/VDR mice, relative to wild-type and VDR mice, but no differences between triple and double knockouts. Further, ex vivo treatment of live kidney slices isolated from wild-type and Klotho/VDR mice with soluble Klotho did not induce changes in intracellular phosphate, calcium or sodium accumulation assessed by two-photon microscopy. In conclusion, our data suggest that the main physiological function of Klotho for mineral homeostasis in vivo is its role as co-receptor mediating Fgf23 action. © 2017 American Society for Bone and Mineral Research.

Effect of bevacizumab, a vascular endothelial growth factor inhibitor, on a rat model of peritoneal sclerosis.

PURPOSE: Peritoneal fibrosis is almost uniform feature encountered in peritoneal dialysis patients. The transition of epithelial cells to mesenchymal phenotype, neovascularization, and consequently development of peritoneal fibrosis occur due to the involvement of peritoneal membrane by various insults such as uremia itself, peritonitis attacks, and exposure to bio-incompatible peritoneal dialysis fluids. Bevacizumab is a monoclonal antihuman antibody developed against vascular endothelial growth factor and can reduce fibrosis by preventing neovascularization. There has been no study so far that demonstrates the effect of bevacizumab on peritoneal fibrosis in a rat model. METHODS: A total of 41 female Wistar albino rats were divided into six groups. The control group (C) received 0.9 % isotonic saline (2 ml/day) intraperitoneally (i.p) for 21 days. Chlorhexidine group (CH) received 15 % ethyl alcohol and 0.1 % chlorhexidine gluconate (CG) in saline (2 ml/day) i.p for 21 days. The resting group (R) received CG 2 ml/day i.p for 21 days. The bevacizumab-1 group (B1) received CG 2 ml/day i.p for 21 days and bevacizumab 2.5 mg/kg i.p as a single dose on day 21. The bevacizumab-2 group (B2) received CG 2 ml/day for 21 days and bevacizumab 2.5 mg/kg i.p on day 0 and day 21. The bevacizumab-3 group (B3) received bevacizumab 2.5 mg/kg i.p on day 0 and day 21. Peritoneal samples were taken from the left anterior abdominal wall. The thickness, vascularization, and fibrosis scores in the peritoneal samples were assessed using a light microscope. RESULTS: On histopathological evaluations, peritoneum thicknesses, vascularization scores, and fibrosis significantly decreased in bevacizumab groups B1 and B2. CONCLUSION: Histopathologically, bevacizumab was proven to attenuate fibrotic process in experimental peritoneal sclerosis model.

Postpartum ovarian vein and inferior vena cava thrombosis.

Postpartum ovarian vein thrombosis (POVT), which generally occurs 2-15 days postpartum, is a rare complication. It can be confused with acute appendicitis, pelvic infection, ovarian torsion, tubo-ovarian abscess, and pyelonephritis. It is associated with morbidity and mortality. Here, we present a patient with postpartum OVT and IVC diagnosed by US and CT findings. She was treated successfully with no further need for any interventional procedures.

Pauci-immune necrotizing crescentic glomerulonephritis with crescentic and full moon extracapillary proliferation: clinico-pathologic correlation and follow-up study.

The prognostic value of the type and extent of extracapillary proliferation (ECP) in pauci-immune necrotizing crescentic glomerulonephitis (PIGN) was evaluated in this study. In 141 PIGN cases, all glomeruli with ECP were grouped according to type (cellular, fibrocellular and fibrous) and extent of the lesions in Bowman's space; (segmental, semicircumferential and circumferential, which might be termed full moon-FM). Cases with cellular and fibrous lesions involving ≥ 50% of glomeruli with ECP were classified as cellular and fibrous groups, respectively, while the remaining cases were classified as fibrocellular. Cases with segmental and circumferential (FM glomerulus) lesions involving ≥ 50% of glomeruli with ECP were classified as ECPI and ECPIII (FM) groups, respectively, while the rest were classified as ECPII. All the cases were classified according to Berden et al. Significant results were only nearly obtained for the FM group, including the need for dialysis. The Cox regression model revealed a 2.6-fold risk for FM cases regarding dialysis requirement. We propose that the percentage of FM glomeruli should be noted in the pathology report, and cases with more than 50% of FM glomeruli (FM group) should be identified in the group with increased risk of dialysis requirement. Our series also suggests that classification according to Berden et al. is of clinical relevance.