Effects of Adrenomedullin and Glucagon-like Peptide on Distal Flap Necrosis and Vascularity: The Role of Receptor Systems and Nitric Oxide.

OBJECTIVE: Flap necrosis in the distal area due to the deficiency of blood circulation is a major complication in flap treatment. In many previous studies, some natural substances such as chlorogenic acid, adrenomedullin (ADM), and glucagon-like peptide-1 (GLP-1) have been used to improve flap viability via their vasodilator, angiogenic, and antioxidant effects. The aim of this study is to clarify the mechanism through the use of selective antagonists for calcitonin gene-related peptide (CGRP) receptors and GLP-1 receptors such as CGRP-(8-37), exendin-(9-39), respectively, in the flap healing effects of ADM and GLP-1. The role of nitric oxide (NO) was investigated in the mechanism as well. MATERIALS AND METHODS: Seventy adult female Wistar rats (200 g-250 g) were used in the study. The cutaneous skin flap (8 cm x 3 cm) on the abdominal wall was raised based on the superficial inferior epigastric artery (SIEA). Single-dose substance injections were administered into the SIEA. Necrosis in the flap area was evaluated on postoperative day 7. The proportion of the necrosis area (necrosis area % = [necrosis area/flap area] x 100) and vascularity (vascular number/cm2) in the distal area were calculated. RESULTS: The administrations of ADM or GLP-1 increased the vascularity and decreased the necrosis area in the distal flap region. The ADM receptor antagonist, CGRP-(8-37), did not prevent the positive effects of ADM on flap healing and vascularity. A GLP-1 receptor antagonist, exendin-(9-39), prevented the effect of GLP-1 on flap healing and vascularity. Nitric oxide mediated the beneficial effects of both peptides on flap healing. CONCLUSION: The CGRP receptors have no direct role, but NO acts as a mediator in the beneficial effect of ADM on flap healing. The GLP-1 specific receptors and NO act as important interagents for the effects of GLP-1 on flap healing.

Effects of choline treatment in concentrations of serum matrix metalloproteinases (MMPs), MMP tissue inhibitors (TIMPs) and immunoglobulins in an experimental model of canine sepsis.

The aim of the present study was to investigate effects of intravenous (i.v.) choline treatment on serum matrix metalloproteinases (MMP), MMP tissue inhibitors (TIMP) and immunoglobulins (Igs), and to determine if there were relations between serum MMPs/TIMPs and C-reactive protein (CRP) (as a marker of the acute phase response), immunoglobulin G and M (IgG and IgM) (as a maker of the Ig responses) and markers of organ damage such as muscular damage (creatine phosphokinase, [CPK]), liver damage (alanine aminotransferase [ALT]) and renal dysfunction (blood urea nitrogen [BUN] and creatinine, [Cr]) in dogs with endotoxemia. Healthy dogs (n=24) were randomized to Saline, Choline (C), Lipopolysaccharide (LPS), and LPS+C groups and received 0.9% NaCl (5mL/i.v.), choline chloride (20mg/kg/i.v.), LPS (0.02mg/kg/i.v.) and LPS (0.02mg/kg/i.v.) plus choline chloride (20mg/kg/i.v.), respectively. Serum MMPs and TIMPs concentrations were analyzed by commercial ELISA kits. MMP and TIMP increased at 1-48h (P<0.05), whereas IgG and IgM decreased at 24-48h in LPS group, compared to their baselines. Choline treatment reduced changes in serum MMPs, TIMPs and markers of organ damage, and prevented the hypoimmunoglobulinemia in LPS+C. MMPs and TIMPs were correlated positively (P<0.05) with serum CRP, CPK, ALT, BUN and Cr, but not with serum Igs. Our findings suggest that the serum MMPs, TIMPs and Igs are involved in the pathophysiology of endotoxemia, and MMPs and TIMPs are correlated with the acute phase reaction and multi-organ failure. In addition, we demonstrated a direct effect of choline administration in decreasing serum MMPs and TIMPs, and preserving serum Igs in the course of endotoxemia.

Characterisation of bovine viral diarrhoea virus (BVDV) isolates from an outbreak with haemorrhagic enteritis and severe pneumonia.

During 2007 a disease outbreak occurred in cattle in the Marmara region of western Turkey characterised by severe pneumonia and haemorrhagic enteritis in calves. Cases from three farms at different locations were examined and bovine viral diarrhoea virus (BVDV) isolated in all cases. Phylogenetic characterisation of the virus isolates allocated them in a new cluster tentatively named as BVDV-1r.

Accumulation profiles of PrP(Sc) in hemal nodes of naturally and experimentally scrapie-infected sheep.

BACKGROUND: In classical scrapie, the disease-associated abnormal isoform (PrP(Sc)) of normal prion protein accumulates principally in the nervous system and lymphoid tissues of small ruminants. Lymph nodes traffic leukocytes via lymphatic and blood vasculatures but hemal nodes lack lymphatic vessels and thus traffic leukocytes only via the blood. Although PrP(Sc) accumulation profiles are well-characterized in ovine lymphoid tissues, there is limited information on such profiles in hemal nodes. Therefore, the objective of this study was to compare the follicular accumulation of PrP(Sc) within hemal nodes and lymph nodes by prion epitope mapping and western blot studies. RESULTS: Our studies found that PrP(Sc) accumulation in 82% of animals' abdominal hemal nodes when PrP(Sc) is detected in both mesenteric and retropharyngeal lymph nodes collected from preclinical and clinical, naturally and experimentally (blood transfusion) scrapie-infected sheep representing all three major scrapie-susceptible Prnp genotypes. Abdominal hemal nodes and retropharyngeal lymph nodes were then used to analyze immune cell phenotypes and PrP(Sc) epitope mapping by immunohistochemistry and PrP(Sc) banding patterns by western blot. Similar patterns of PrP(Sc) accumulation were detected within the secondary follicles of hemal nodes and retropharyngeal lymph nodes, where cellular labeling was mostly associated with macrophages and follicular dendritic cells. The pattern of PrP(Sc) accumulation within hemal nodes and retropharyngeal lymph nodes also did not differ with respect to epitope mapping with seven mAbs (N-terminus, n = 4; globular domain, n = 2; C-terminus, n = 1) in all three Prnp genotypes. Western blot analysis of hemal node and retropharyngeal lymph node homogenates revealed identical three banding patterns of proteinase K resistant PrP(Sc). CONCLUSION: Despite the anatomical difference in leukocyte trafficking between lymph nodes and hemal nodes, the follicles of hemal nodes appear to process PrP(Sc) similarly to lymph nodes.