N-acetylcysteine modulates effect of the iron isomaltoside on peritoneal mesothelial cells.

Intravenous (i.v.) iron supplementation is used in patients on chronic peritoneal dialysis (pd). Iron induced intraperitoneal inflammation observed in our previous studies with iron sucrose may deteriorate the function of the peritoneum as the dialysis membrane. We evaluated effect iron compound, iron-isomaltoside-100 (IIS) on the peritoneal mesothelial cells (MC). We studied the effect of iv treatment with IIS ± N-acetylcysteine (NAC) on the dialysate parameters and function of MC. In 7 uremic pd patients IIS 200 mg was infused i.v. ± NAC 600 mg. Afterward, a 4 hours exchange was performed with Dianeal 1.5%. As a control dialysate exchange preceding IIS treatment was used. Inflammatory parameters of the drained dialysates as well as the dialysates and IIS effects on MC were evaluated in ex vivo experiments. Intravenous infusion of IIS resulted in an increase of the dialysate Fe (+147%, P < 0.01). Concentrations of the dialysates inflammatory mediators were increased: interleukin-6 (IL-6) +39%, P < 0.02, monocyte chemoattractant protein-1(MCP1) +50%, P < 0.02, and hyaluronan (HA) +64%, P < 0.02. Simultaneous i.v. infusion of NAC prevented increase of the dialysate inflammatory mediators. Dialysates collected after IIS treatment induced oxidative stress in MC (+29%, P < 0.05) and stimulated IL-6 synthesis (+64%, P < 0.05) in MC; no such effect was seen in dialysates obtained after simultaneous IIS and NAC i.v. treatment. IIS used as the additive to culture medium stimulated synthesis in MC of IL6 (+76%, P < 0.001) and plasminogen activator inhibitor-1 (PAI-1) (28%, P < 0.001) whereas synthesis of tissue plasminogen activator (t-PA) was reduced (-16%, P < 0.001). These changes were prevented in the presence of NAC 1 mmol/L. Intravenous administration of IIS results in the mild stimulation of intraperitoneal inflammation. IIS changes MC phenotype to the inflammatory one with reduced fibrinolytic activity. These effects are prevented by NAC.

Impact of Perfusate Concentration on Hyperthermic Intraperitoneal Chemotherapy Efficacy and Toxicity in a Rodent Model.

BACKGROUND: Cytoreductive surgery followed by hyperthermic intraperitoneal chemotherapy (HIPEC) has been shown to be beneficial in treating limited peritoneal carcinomatosis (PC) from colorectal cancer (CRC). Perfusate volume directly affects treatment concentration and therefore is a key parameter defining HIPEC; yet little is known about the impact of perfusate concentration on systemic toxicity and treatment morbidity. MATERIALS AND METHODS: PC was induced through intraperitoneal injection of human CRC cell lines. A novel perfusion model was developed to treat athymic nude mice with continuous circulation of adequately miniaturized volumes of heated perfusate. Oxaliplatin HIPEC was performed applying different volumes of perfusate with fixed doses or fixed concentrations. Early postoperative mortality and morbidity were assessed as well as long-term survival. In addition, antiproliferative and proapoptotic effects of HIPEC were determined in vitro and in vivo. RESULTS: Perfusate concentration crucially affected the toxicity of fixed-dose oxaliplatin HIPEC as indicated by postoperative weight loss and early postoperative mortality. Applying different perfusate volumes at a fixed concentration did not influence toxicity. Adequately miniaturized HIPEC with oxaliplatin did not exert relevant cytotoxic effects toward PC arising from human CRC cells in vivo. CONCLUSIONS: We describe a novel murine model that adequately miniaturizes all physical parameters of HIPEC as applied in humans. HIPEC drug concentration is a crucial parameter determining excess toxicity and should be better standardized. HIPEC with oxaliplatin fails to induce relevant antitumor activity or to improve survival in this murine model of PC from CRC.

The effect of Punica granatum L. flower extract on post-surgical peritoneal adhesions in a rat model.

OBJECTIVE: Peritoneal adhesions may develop after every abdominopelvic surgery. Many agents and technical modifications have been investigated to minimize adhesions. Punica granatum (pomegranate) flower has some anti-inflammatory and antioxidative effects that would reduce the formation of peritoneal adhesions. In the present study, the effects of different doses of oral Punica granatum flower extract on postoperative peritoneal adhesions were evaluated in a rat model. STUDY DESIGN: Thirty-two female Wistar rats were divided into four groups: one control group (CG) and three experimental groups, treated with 100 (EG100), 200 (EG200), and 400 (EG400) mg/kg/day Punica granatum extract orally for eight days. Induction of peritoneal adhesions was done in all groups using the same method. Two weeks after the first surgery, all rats re-operated and adhesions were evaluated via both macroscopic and microscopic changes. RESULTS: We observed that rats in the control group had statistically higher adhesion area and more severe adhesions when compared to all experimental groups. Besides, those in the EG-400 group had a significantly lower rate of foreign body reaction in serosal layer when compared to the other three study groups. Other microscopic findings were comparable between the four groups. CONCLUSION: Administration of the oral Punica granatum flower extract was associated with a decreased quantity and quality of the adhesions in the animal model of rat in this study. This therapy might be an effective and safe strategy to reduce intraperitoneal adhesion after abdominal surgeries in animal models.

Parthenolide, an NF-κB inhibitor, alleviates peritoneal fibrosis by suppressing the TGF-ß/Smad pathway.

Transforming growth factor (TGF)-ß/Smad signalling plays a central role in the pathogenesis of peritoneal fibrosis related to peritoneal dialysis (PD). Parthenolide (PTL), a naturally occurring phytochemical, is isolated from the shoots of feverfew (Tanacetum parthenium) and displays analgesia, anti-inflammation and anticancer activities. In this study, we examined the therapeutic potential of PTL on PD-related peritoneal fibrosis induced by daily intraperitoneal injection of 4.25% dextrose-containing PD fluid (PDF) in vivo and TGF-ß1-induced epithelial-mesenchymal transition (EMT) in vitro. PTL was administered daily before PDF injection or after 14 days of PDF injection. Both PTL treatments showed a protective effect on peritoneal fibrosis and prevented peritoneal dysfunction. Similarly, PTL suppressed the expression of fibrotic markers (fibronectin and collagen I) and restored the expression of the epithelial marker (E-cadherin) in TGF-ß1-treated HMrSV5 cells. Furthermore, PTL inhibited TGF-ß1-induced Smad2 and Smad3 phosphorylation and nuclear translocation but did not influence Smad1/5/9 phosphorylation or activate other downstream signalling pathways of TGF-ß1, including AKT, extracellular signal-regulated kinase (ERK) or p38. In conclusion, PTL treatment may represent an effective and novel therapy for PD-associated peritoneal fibrosis by suppressing the TGF-ß/Smad pathway.

Curcumin ameliorates peritoneal fibrosis via inhibition of transforming growth factor-activated kinase 1 (TAK1) pathway in a rat model of peritoneal dialysis.

BACKGROUND: Peritoneal fibrosis (PF) remains a serious complication of long-term peritoneal dialysis (PD). The goal of this study was to investigate the anti-fibrotic effects of curcumin on the PF response to PD and its' mechanism. METHODS: Male Sprague-Dawley rats were infused with 20 mL of 4.25% glucose-based standard PD fluid for 8 consecutive weeks to establish PF model and then divided into five groups: Control, received sham operation and 0.9% physiological saline; PD, received 4.25% standard PD fluid; Curcumin, PD rats injected intraperitoeally with curcumin for 8 weeks at doses of 10, 20 or 40 mg/kg. Masson's staining was performed to evaluate the extent of PF. Peritoneal Equilibration Test (PET) was conducted to assess ultrafiltration volume (UFV) and mass transfer of glucose (MTG), quantitative RT-PCR, and immunohistochemistry or western blotting were performed to measure the expression levels of inflammation and fibrosis-associated factors. We also detected the TGF-ß1 in peritoneal fluid by ELISA. RESULTS: Compared with the control group, the PD rats showed decreased UFV (2.54 ± 0.48 to 9.87 ± 0.78 mL, p < 0.05] and increased MTG (18.99 ± 0.86 to 10.85 ± 0.65 mmol/kg, p < 0.05) as well as obvious fibroproliferative response, with markedly increased peritoneal thickness (178.33 ± 4.42 to 25.26 ± 0.32um, p < 0.05) and higher expression of a-SMA, collagen I and TGF-ß1. Treatment with curcumin significantly increased UFV, reduced MTG and peritoneal thickness of PD rats. The elevated TGF-ß1 in peritoneal fluid of PD rats was significantly decreased by curcumin. It attenuated the increase in protein and mRNA of TGF-ß1, α-SMA and collagen I in peritoneum of PD rats. The mRNA expressions of TAK1, JNK and p38, as well as the protein expressions of p-TAK1, p-JNK and p-p38 in peritoneum of PD rats were reduced by curcumin. CONCLUSIONS: Present results demonstrate that curcumin showed a protective effect on PD-related PF and suggest an implication of TAK1, p38 and JNK pathway in mediating the benefical effects of curcumin.

Zinc supplementation inhibits the high glucose­induced EMT of peritoneal mesothelial cells by activating the Nrf2 antioxidant pathway.

The high glucose (HG)­induced epithelial­mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) serves an important role in peritoneal fibrosis (PF) during peritoneal dialysis. Our previous study reported that zinc (Zn) supplementation prevented the HG­induced EMT of rat PMCs in vitro. In the present study, the role of Zn in HG­induced EMT was investigated in vivo using a rat model of PF. Additionally, the molecular mechanisms underlying HG­induced EMT were studied in human PMCs (HPMCs). In the rat model of PF, HG treatment increased the glucose transfer capacity and decreased the ultrafiltration volume. Histopathological analysis revealed peritoneal thickening, increased expression of vimentin and decreased expression of E­cadherin. ZnSO4 significantly ameliorated the aforementioned changes, whereas Zn inhibition by clioquinol significantly aggravated the effects of HG on rats. The effects of Zn on HPMCs was assessed using western blot analysis, Transwell assays and flow cytometry. It was revealed that Zn also significantly suppressed the extent of the EMT, and reduced reactive oxygen species production and the migratory ability of HG­induced HPMCs, whereas Zn inhibition by N',N',N',N'­tetrakis (2­pyridylmethyl) ethylenediamine significantly potentiated the HG­induced EMT of HPMCs. HG­stimulated HPMCs exhibited increased expression of nuclear factor­like 2 (Nrf2) in the nucleus, and total cellular NAD(P)H quinone dehydrogenase 1 (NQO1) and heme oxygenase-1 (HO­1), the target proteins of the Nrf2 antioxidant pathway. Zn supplementation further promoted nuclear Nrf2 expression, and increased the expression of target proteins of the Nrf2 antioxidant pathway, whereas Zn depletion decreased nuclear Nrf2, NQO1 and HO­1 expression compared with the HG group. In conclusion, Zn supplementation was proposed to suppress the effects of HG on the EMT by stimulating the Nrf2 antioxidant pathway and subsequently reducing oxidative stress in PMCs.

Perioperative systemic therapy and cytoreductive surgery with HIPEC versus upfront cytoreductive surgery with HIPEC alone for isolated resectable colorectal peritoneal metastases: protocol of a multicentre, open-label, parallel-group, phase II-III, randomised, superiority study (CAIRO6)

BACKGROUND: Upfront cytoreductive surgery with HIPEC (CRS-HIPEC) is the standard treatment for isolated resectable colorectal peritoneal metastases (PM) in the Netherlands. This study investigates whether addition of perioperative systemic therapy to CRS-HIPEC improves oncological outcomes. METHODS: This open-label, parallel-group, phase II-III, randomised, superiority study is performed in nine Dutch tertiary referral centres. Eligible patients are adults who have a good performance status, histologically or cytologically proven resectable PM of a colorectal adenocarcinoma, no systemic colorectal metastases, no systemic therapy for colorectal cancer within six months prior to enrolment, and no previous CRS-HIPEC. Eligible patients are randomised (1:1) to perioperative systemic therapy and CRS-HIPEC (experimental arm) or upfront CRS-HIPEC alone (control arm) by using central randomisation software with minimisation stratified by a peritoneal cancer index of 0-10 or 11-20, metachronous or synchronous PM, previous systemic therapy for colorectal cancer, and HIPEC with oxaliplatin or mitomycin C. At the treating physician's discretion, perioperative systemic therapy consists of either four 3-weekly neoadjuvant and adjuvant cycles of capecitabine with oxaliplatin (CAPOX), six 2-weekly neoadjuvant and adjuvant cycles of 5-fluorouracil/leucovorin with oxaliplatin (FOLFOX), or six 2-weekly neoadjuvant cycles of 5-fluorouracil/leucovorin with irinotecan (FOLFIRI) followed by four 3-weekly (capecitabine) or six 2-weekly (5-fluorouracil/leucovorin) adjuvant cycles of fluoropyrimidine monotherapy. Bevacizumab is added to the first three (CAPOX) or four (FOLFOX/FOLFIRI) neoadjuvant cycles. The first 80 patients are enrolled in a phase II study to explore the feasibility of accrual and the feasibility, safety, and tolerance of perioperative systemic therapy. If predefined criteria of feasibility and safety are met, the study continues as a phase III study with 3-year overall survival as primary endpoint. A total of 358 patients is needed to detect the hypothesised 15% increase in 3-year overall survival (control arm 50%; experimental arm 65%). Secondary endpoints are surgical characteristics, major postoperative morbidity, progression-free survival, disease-free survival, health-related quality of life, costs, major systemic therapy related toxicity, and objective radiological and histopathological response rates. DISCUSSION: This is the first randomised study that prospectively compares oncological outcomes of perioperative systemic therapy and CRS-HIPEC with upfront CRS-HIPEC alone for isolated resectable colorectal PM. TRIAL REGISTRATION: Clinicaltrials.gov/ NCT02758951 , NTR/ NTR6301 , ISRCTN/ ISRCTN15977568 , EudraCT/ 2016-001865-99 .

Protective effects and mechanisms of omega-3 polyunsaturated fatty acid on intestinal injury and macrophage polarization in peritoneal dialysis rats.

AIM: This study was conducted to investigate the chronic injury of peritoneal glucose injection on the peritoneum and intestine and the protective effects of omega-3 polyunsaturated fatty acid (ω-3PUFA) during peritoneal dialysis (PD). METHODS: Peritoneal dialysis animal models were established by intraperitoneal injection of 4.25% glucose for 28 days. Protein expression in ileum and peritoneum was measured by immunofloresence and immunohistochemistry. Protein expression in macrophages was measured by Western blot. Fibrosis was analyzed by Masson staining. RESULTS: Peritoneal dialysis significantly increased the structural injury and decreased junction-related protein ZO-1 and occludin expression in ileum, the expression of proteins relating to the activation of M2 (Erg2, IRF4), but not M1 (CD38, IRF5) macrophages. PD significantly increased the expression of TGF-ß1, VEGF and ALK5 protein in peritoneal tissues. PD significantly increased fibrosis (Masson staining) and the expression of fibroblast marker α-SMA in peritoneal tissues. Injection of macrophage clean reagent and ω-3PUFA significantly inhibited M2 activation, and decreased Masson staining, α-SMA, TGF-ß1, VEGF and ALK5 protein expression in peritoneal tissues in PD treated rats. ω-3PUFA injection significantly decreased PD-induced injury in ileum and normalized the expression of ZO-1 and occludin in the ileum of PD rats. CONCLUSION: Omega-3 fatty acids can provide a protective role on PD-induced peritoneal fibrosis and injury of the intestine.

Astragalus Inhibits Epithelial-to-Mesenchymal Transition of Peritoneal Mesothelial Cells by Down-Regulating ß-Catenin.

BACKGROUND/AIMS: The epithelial-to-mesenchymal transition (EMT) of peritoneal mesothelial cells (PMCs) is a crucial event in the induction of peritoneal fibrosis (PF), in which canonical Wnt/ß-catenin signaling participates. Smads signaling is reported to interact with ß-catenin and synergistically regulates EMT. This study was aimed to reveal the effect of Astragalus on ß-catenin in EMT of PMCs. METHODS: To obtain the role of ß-catenin in EMT, gene transfer into HMrSV5 cell line and rats has been achieved. After Astragalus treatment, EMT markers and signaling pathway-related indicators were detected by western blotting, immunofluorescence, immunohistochemistry, immunoprecipitation and real time-PCR. RESULTS: ß-catenin knockdown suppressed EMT of HMrSV5 cells. Astragalus alleviated EMT of PMCs characterized by increased E-cadherin and decreased α-SMA and Vimentin. In rat model of peritoneal dialysis (PD), Astragalus attenuated peritoneal thickening and fibrosis. Astragalus down-regulated ß-catenin by stabilizing the Glycogen synthase kinase-3ß (GSK-3ß)/ß-catenin complex and further inhibited the nuclear translocation of ß-catenin. Meanwhile, Astragalus down-regulated ß-catenin by enhancing Smad7 expression. Silencing Smad7 antagonized the EMT-inhibitory effect of Astragalus. CONCLUSION: Astragalus inhibits EMT of PMCs by down-regulating ß-catenin. The modulation of ß-catenin in peritoneum can be a novel tool to prevent PF.

A randomized controlled trial of alanyl-glutamine supplementation in peritoneal dialysis fluid to assess impact on biomarkers of peritoneal health.

In early clinical testing, acute addition of alanyl-glutamine (AlaGln) to glucose-based peritoneal dialysis (PD) fluids restored peritoneal cellular stress responses and leukocyte function. This study was designed to test the effect of extended treatment with AlaGln-supplemented PD fluid on biomarkers of peritoneal health. In a double-blinded, randomized crossover design, stable PD patients were treated with AlaGln (8 mM) or placebo added to PD fluid for eight weeks. As primary outcome measures, dialysate cancer-antigen 125 (CA-125) appearance rate and ex vivo stimulated interleukin-6 (IL-6) release were assessed in peritoneal equilibration tests. In 8 Austrian centers, 54 patients were screened, 50 randomized, and 41 included in the full analysis set. AlaGln supplementation significantly increased CA-125 appearance rate and ex vivo stimulated IL-6 release. AlaGln supplementation also reduced peritoneal protein loss, increased ex vivo stimulated tumor necrosis factor (TNF)-α release, and reduced systemic IL-8 levels. No adverse safety signals were observed. All 4 peritonitis episodes occurred during standard PD fluid treatment. A novel AlaGln-supplemented PD fluid improves biomarkers of peritoneal membrane integrity, immune competence, and systemic inflammation compared to unsupplemented PD fluid with neutral pH and low-glucose degradation. A phase 3 trial is needed to determine the impact of AlaGln supplementation on hard clinical outcomes.

EW-7197, an oral transforming growth factor ß type I receptor kinase inhibitor, for preventing peritoneal adhesion formation in a rat model.

BACKGROUND: EW-7197 is an oral transforming growth factor ß type I receptor kinase inhibitor currently undergoing phase I clinical trials for cancer treatment in the United States. This study evaluates whether EW-7197 prevents peritoneal adhesion formation in a rat model. METHODS: Forty-eight female Wistar rats underwent peritoneal adhesion induction by the creation of peritoneal ischemic buttons and were randomly divided into 4 groups of 12 each. The control group received 0.3 mL vehicle by oral gavage once daily for 7 days after adhesion induction. The 10 mg and 20 mg groups received 10 or 20 mg/kg EW-7197 phosphate dissolved in 0.3 mL vehicle by oral gavage once daily for 7 days after adhesion induction. The rebound group received 20 mg/kg EW-7197 phosphate dissolved in 0.3 mL vehicle by oral gavage once daily for 7 days after adhesion induction followed by 0.3 mL vehicle only by gavage once daily for an additional 21 days. After the respective treatments were completed, the animals were euthanized. RESULTS: All rats survived until the end of the study without complications. EW-7197 reduced the incidence, quality, and tenacity of peritoneal adhesions in a dose-dependent manner. Fibrosis and collagen production were reduced in EW-7197-treated peritoneal ischemic buttons. Transforming growth factor ß/Smad2/3 signaling and mesothelial-to-mesenchymal transition were inhibited in EW-7197-treated peritoneal ischemic buttons. Discontinuation of EW-7197 was not associated with rebound effects. CONCLUSION: EW-7197 prevented peritoneal adhesion formation potentially via inhibition of transforming growth factor ß1/Smad2/3-induced mesothelial-to-mesenchymal transition in a rat model.

Rationale for the administration of systemic 5-FU in combination with heated intraperitonal oxaliplatin.

BACKGROUND: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) with oxaliplatin (OX) is the standard of care for selected patients with peritoneal carcinomatosis of colorectal origin. Because 5-FU is mandatory to improve efficacy of OX when used by systemic route, several teams now empirically combine intravenous (IV) 5-FU with HIPEC OX, but this practice has yet to be supported by preclinical data. Using a murine model, we studied the impact of IV 5-FU on peritoneal absorption of HIPEC OX. METHODS: Under general anesthesia, 24 Sprague-Dawley rats were submitted to 4 different doses of IV 5-FU (0, 100, 400 and 800 mg/m2) and a fixed dose of HIPEC OX (460 mg/m2) perfused at 40 °C during 25 min. At 25 min, samples in different compartments were harvested (peritoneum, portal vein and systemic blood) and the concentrations of 5-FU and OX were measured by high performance liquid chromatography. RESULTS: Peritoneal absorption of OX was significantly higher (17.0, 20.1, 34.9 and 38.1 nmol/g, p < 0.0001) with increasing doses of 5-FU (0, 100, 400 and 800 mg/m2, respectively). Peritoneal absorption of OX reached a plateau between 400 and 800 mg/m2 of IV 5-FU. CONCLUSION: IV 5-FU enhances peritoneal absorption of HIPEC OX. The most efficient dose of IV 5-FU to be used in combination with HIPEC OX seems to be 400 mg/m2.

Sulfotanshinone IIA Sodium Ameliorates Glucose Peritoneal Dialysis Solution-Induced Human Peritoneal Mesothelial Cell Injury via Suppression of ASK1-P38-mediated Oxidative Stress.

BACKGROUND/AIMS: Long-term use of high-glucose peritoneal dialysis solution (PDS) induces peritoneal mesothelial cell (PMC) injury, peritoneal dysfunction, and peritoneal dialysis (PD) failure in patients with end-stage renal disease. How to preserve PMCs in PD is a major challenge for nephrologists worldwide. In this study, we aimed to elucidate the efficacy and mechanisms of sulfotanshinone IIA sodium (Tan IIa) in ameliorating high-glucose PDS-induced human PMC injury. METHODS: The human PMC line HMrSV5 was incubated with 4.25% PDS in vitro to mimic the high-glucose conditions in PD. Cellular viability was measured by Cell Counting Kit 8. Generation of superoxide and reactive oxygen species (ROS) was assessed using a Total ROS/Superoxide Detection Kit. Oxidative modification of protein was evaluated by OxyBlot Protein Oxidation Detection Kit. TUNEL (dT-mediated dUTP nick end labeling) assay and DAPI (4,6-diamidino-2-phenylindole) staining were used to evaluate apoptosis. Western blot analysis was performed to evaluate the efficacy and mechanisms of Tan IIa. RESULTS: Tan IIa protected PMCs against PDS-induced injury as evidenced by alleviating changes in morphology and loss of cell viability. Consistent with their antioxidant properties, N-acetyl-L-cysteine (NAC) and Tan IIa suppressed superoxide and ROS production, protein oxidation, and apoptosis elicited by PDS. Apoptosis signal-regulating kinase 1 (ASK1)-p38 signaling was activated by PDS. Both Tan IIa and NAC suppressed ASK1 and p38 phosphorylation elicited by PDS. Moreover, genetic downregulation of ASK1 ameliorated cell injury and inhibited the phosphorylation of p38 and activation of caspase 3. CONCLUSION: Tan IIa protects PMCs against PDS-induced oxidative injury through suppression of ASK1-p38 signaling.

Comparison of efficacy of oral and parenteral cobalamin supplementation in normalising low cobalamin concentrations in dogs: A randomised controlled study.

The aim of this study was to compare the efficacies of parenteral and oral cobalamin supplementation protocols in dogs with chronic enteropathies and low cobalamin concentrations. It was hypothesised that both treatments would increase serum cobalamin concentrations significantly. Fifty-three dogs with chronic enteropathies and serum cobalamin concentrations<285ng/L (reference interval 244-959ng/L) were enrolled. Dogs were randomised to treatment with either daily oral cobalamin tablets (0.25-1.0mg cyanocobalamin daily according to body weight) or parenteral cobalamin (0.4-1.2mg hydroxycobalamin according to body weight). Serum cobalamin concentrations were analysed 28±5days and 90±15days after initiation of supplementation. After 28 days, all dogs had serum cobalamin concentrations within the reference interval or above. In the parenteral group (n=26), median (range) cobalamin concentrations were 228 (150-285) ng/L at inclusion, 2107 (725-10,009) ng/L after 28days and 877 (188-1267) ng/L after 90 days. In the oral group (n=27), median (range) serum cobalamin concentrations were 245 (150-285) ng/L at inclusion, 975 (564-2385) ng/L after 28days and 1244 (738-4999) ng/L after 90 days. In both groups, there were significant differences in serum cobalamin concentrations between baseline and 28 days, and between 28days and 90days (P<0.001). In conclusion, both parenteral and oral cobalamin supplementation effectively increase serum cobalamin concentrations in dogs with chronic enteropathies and low cobalamin concentrations.

L-2-oxothiazolidine-4-carboxylic acids slow down dialysate-induced senescence in human peritoneal mesothelial cells.

Peritoneal dialysis induces an intraperitoneal inflammatory reaction, which in the long term may cause deterioration of the peritoneal structure and function as the dialysis membrane. We studied the effect of the overnight effluent dialysate from patients on chronic peritoneal dialysis on aging of the human peritoneal mesothelial cells in an in vitro model of replicative cellular senescence. In the control group cells were cultured in the standard medium and in the studied groups in culture medium mixed 1:1 v/v with the dialysate ± L-2-oxothiazolodine-4-carboxylic acid 1 mmol/L (OTZ). OTZ was used as the precursor for the synthesis of glutathione in these cells. Dialysate accelerated senescence of the mesothelial cells as reflected by elongation of their population doubling time, reduced expression of KI-67 gene, and increased ß-galactosidase activity. Also, expression of the genes regulating the production of the inflammatory mediators (interleukin-6, monocyte chemoattractant protein-1, metalloproteinase-2, hyaluronan), proangiogenic (VEGF) and profibrotic (fibronectin) factors was increased in that group. At the same time, these cells secreted more inflammatory mediators. Simultaneous treatment of the cells with the dialysate and OTZ slowed down their senescence, whose intensity was similar to that in the control group. The results presented in this manuscript prove that the intraperitoneal inflammatory reaction induced by repeated infusions of the dialysis fluid accelerates the senescence of the mesothelial cells, which may result in fibrosis and neoangiogenesis within the peritoneum. Simultaneous supplementation of the cells with a glutathione precursor (OTZ) may prevent the development of these pathological changes.

Effects of nivolumab in peritoneal carcinamatosis of malign melanoma in mouse model

Abstract Purpose: To evaluate the efficacy of nivolumab and comparison with dacarbazine (DTIC) on peritoneal carcinomatosis of malignant melanoma in mouse model. Methods: Mouse skin melanoma cells was injected under the capsule of the peritoneal surface in the left side of the abdomen. On postoperative day ten, mouses randomised into three groups. Group 1: Control, Group 2: HIPEC (Hyperthermic intraperitoneal chemotherapy) with DTIC and Group 3: HIPEC with Nivolumab. After the sacrification on postoperative day fifteen, peritoneum evaluated macroscopically and histopathologically by using peritoneal regression grading score (PRGS). Results: In the 15th day exploration, all animals developed extensive intraperitoneal tumor growth in Group 1. In Group 2 and Group 3 median tumor size was 0.7±0.3cm and 0.3±0.2cm respectively (p: 0.023). Peritoneal carcinomatosis index (PCI) were significantly lower in Group 3 than other groups (p: 0.019). The lowest total tumor nodules in group 3 was 4 ± 2. The PGRS score was found significantly lower in Group 3 than other groups (p: 0.03). Lymphocytic response rate was found higher in the Group 3. Conclusions: It has been found that nivolumab significantly better than DTIC on peritoneal metastases of malign melanoma in mouse models. Nivolumab treatment gives promising results with pathological evidence in the treatment of metastatic disease of malignant melanoma.

Functional and Transcriptomic Characterization of Peritoneal Immune-Modulation by Addition of Alanyl-Glutamine to Dialysis Fluid.

Peritonitis remains a major cause of morbidity and mortality during chronic peritoneal dialysis (PD). Glucose-based PD fluids reduce immunological defenses in the peritoneal cavity. Low concentrations of peritoneal extracellular glutamine during PD may contribute to this immune deficit. For these reasons we have developed a clinical assay to measure the function of the immune-competent cells in PD effluent from PD patients. We then applied this assay to test the impact on peritoneal immune-competence of PD fluid supplementation with alanyl-glutamine (AlaGln) in 6 patients in an open-label, randomized, crossover pilot trial (EudraCT 2012-004004-36), and related the functional results to transcriptome changes in PD effluent cells. Ex-vivo stimulation of PD effluent peritoneal cells increased release of interleukin (IL) 6 and tumor necrosis factor (TNF) α. Both IL-6 and TNF-α were lower at 1 h than at 4 h of the peritoneal equilibration test but the reductions in cytokine release were attenuated in AlaGln-supplemented samples. AlaGln-supplemented samples exhibited priming of IL-6-related pathways and downregulation of TNF-α upstream elements. Results from measurement of cytokine release and transcriptome analysis in this pilot clinical study support the conclusion that suppression of PD effluent cell immune function in human subjects by standard PD fluid is attenuated by AlaGln supplementation.

Treatment of peritoneal carcinomatosis with hyperthermic intraperitoneal chemotherapy in colorectal cancer.

The peritoneum is the second most common site of metastasis after the liver and the only site of metastatic disease in approximately 25% of patients with colorectal cancer (CRC). In the past, peritoneal carcinomatosis in CRC was thought to be equivalent to distant metastasis; however, the transcoelomic spread of malignant cells is an acknowledged alternative pathway. Metastasectomy with curative intent is well accepted in patients with liver metastasis in CRC despite the paucity of randomized trials. Therefore, there is rationale for local treatment with peritonectomy to eliminate macroscopic disease, followed by hyperthermic intraperitoneal chemotherapy to destroy any residual free tumour cells within the peritoneal cavity. The aim of this paper is to summarize the current evidence for cytoreduction and hyperthermic intraperitoneal chemotherapy in the treatment of peritoneal carcinomatosis in CRC.

Comparison of honey and dextrose solution on post-operative peritoneal adhesion in rat model.

BACKGROUND: Peritoneal adhesion between abdominal organs is a complication of surgery. It causes major complications like pain, bowel obstruction, infertility and increases risk of death. Honey is known to have anti-inflammatory and antioxidant properties potentially relevant for adhesive protection. METHODS: Thirty rats were divided into five groups: negative control without any surgical procedure (normal group), control group treated with normal saline, experimental group I treated with 1ml of 10% honey, experimental group II treated with honey at half concentration of group I (honey0.5), and positive control group receiving 1ml of dextrose 5%. Inflammatory, growth and angiogenesis factors (TNF-α, Il-6, IL-1ß, TGF-ß1 and VEGF) of the adhesion tissue were assessed using ELISA. Antioxidant factors (NO, GSH and MDA) were also assessed using biochemical procedures. RESULTS: The difference between peritoneal adhesion scores, TNF-α, IL-1ß, IL-6, TGF-ß1, VEGF, NO, GSH and MDA value of all groups was strongly significant (p<0.001). We showed that honey can decrease peritoneal adhesion (p<0.001), TNF-α (p<0.001), IL-1ß (p<0.001), IL-6 (p<0.001), TGF-ß1 (p<0.001), VEGF (p<0.001), NO (p<0.001), MDA (p<0.001) and increase GSH (p<0.001) compared with control group. Honey 0.5 also significantly decreased peritoneal adhesion (p<0.001), TNF-α (p<0.001), IL-1ß (p<0.01), IL-6 (p<0.001), VEGF (p<0.001), NO (p<0.001), MDA (p<0.01) and increase GSH (p<0.001) compared with control group. CONCLUSIONS: We find that honey can decrease inflammatory, growth and angiogenesis factors which can advance peritoneal adhesion and increase antioxidant factors. Honey could serve as a protective agent for peritoneal adhesion.