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Introduction: Ultrasound (US) imaging enables tissue visualization in high spatial resolution with short examination times. Thus, it is often applied in preclinical research. Diagnostic US, including contrast-enhanced US (CEUS), is considered to be well-tolerated by laboratory animals although no systematic study has been performed to confirm this claim. Therefore, the aim of this study was to screen for possible effects of US and CEUS examinations on welfare of healthy mice. Additionally, the potential influence of CEUS and molecular CEUS on well-being and therapy response to regorafenib was investigated in breast cancer-bearing mice., Material and Methods: Forty healthy Balb/c mice were randomly assigned for examination with US or CEUS (3×/week) for 4 weeks. Untreated healthy mice and mice receiving only isoflurane anesthesia served as controls (n = 10/group). Ninety-four 4T1 tumor-bearing Balb/c mice were allocated randomly to the following groups: no imaging, isoflurane anesthesia, CEUS, and molecular CEUS. They either received 10 mg/kg regorafenib or vehicle solution daily by oral gavage. Animals were examined three times within 2 weeks. CEUS measurements were performed using phospholipid microbubbles, and phospholipid microbubbles targeting the vascular endothelial growth factor receptor-2 were applied for molecular CEUS. Welfare evaluation was performed by daily observational score sheets, measuring the heart rate, Rotarod performance, and fecal corticosterone metabolites twice a week. On the last day, pathological changes in serum corticosterone concentrations, hemograms, and organ weights were obtained. Moreover, a potential influence of isoflurane anesthesia, CEUS, and molecular CEUS on regorafenib response in tumor-bearing mice was examined. Analysis of variance and Dunnett's post hoc test were performed as statistical analyses., Results: Severity parameters were not altered after repeated US and CEUS examinations of healthy mice, but spleen sizes were significantly lower after isoflurane anesthesia. In tumor-bearing mice, no effect on animal welfare after repeated CEUS and molecular CEUS could be observed. However, leukocyte counts and spleen weights of tumor-bearing mice were significantly lower in animals examined with CEUS and molecular CEUS compared to the control groups. This effect was not visible in regorafenib-treated animals., Conclusions: Repeated US and (molecular) CEUS have no detectable impact on animal welfare in healthy and tumor-bearing mice. However, CEUS and molecular CEUS in combination with isoflurane anesthesia might attenuate immunological processes in tumor-bearing animals and may consequently affect responses to antitumor therapy., (The Author(s). Published by S. Karger AG, Basel.)

Background: Clinical chemistry and hematological tests are widely used to monitor the clinical course of several diseases. However, these parameters are sparse in large-animal models of multiple trauma (MT). Thus, we aimed to provide these missing data to improve future experimental setups in trauma research., Methods: Male pigs (German Landrace pigs) were randomized into either an MT group (n = 8) including blunt thoracic trauma, tibial fracture, and controlled hemorrhage or a sham group (n = 8) without any trauma. After trauma induction, all animals received intensive care treatment for 72 h under anesthesia, including mechanical ventilation and volume resuscitation. Blood and urine samples were obtained to measure common hematological and chemical parameters before trauma (0 h), after trauma (1.5 h), during resuscitation (2.5 h), after fracture stabilization (3.5 h), and at 12, 24, 48, and 72 h. Statistical analyses were performed using a linear mixed model (group × time) and Welch's ANOVA., Results: MT led to a perceptible immunological reaction. Between groups, significantly different time courses of leukocyte counts (p = 0.034) and lymphocyte proportions (p = 0.001) were observed. Moreover, MT changed the time course of total protein (p = 0.006). Significantly lower concentrations compared to sham were found in MT at each single time point starting at 1.5 h to the end of the observation period (all p < 0.05)., Conclusions: Our results indicate that a traumatic insult leads to significant alterations in the immune system already shortly after trauma. Together with the additional catabolic reactions observed, these alterations might contribute to the occurrence of later complications. The presented data provide valid references for further experimental setups with prolonged observation times, especially in similar porcine models of MT., (© 2020 S. Karger AG, Basel.)

Background: The pig is one of the most frequently used large animal models for biomedical research, especially in the field of translational research and surgical models. While standard livestock breeds are used in short-term and acute studies, minipig breeds are the preferred breeds in long-term and chronic studies due to their limited growth and body weight., Objective: In consideration of the 3R principle (refinement, reduction, replacement) and the increasing demand, the aim of this study was to generate a new, robust, non-specific-pathogen-free minipig breed, the Aachen minipig., Methods: Phenotype, genotype, and hematological as well as clinical chemistry parameters were characterized, and reference values of the Aachen minipig were generated and compared to the values in the commonly used Göttingen minipig. Organ weights of the heart, kidney, liver, lung, spleen, and brain were determined using a laboratory balance. Blood samples were collected for hematology and clinical chemistry. Assessment of genetic diversity was performed by microsatellite markers. Nasal swabs were collected from 11 individual minipigs representing 6 races for DNA extraction. DNA was quantified and the identity and origin of the Aachen minipigs at the genomic level was determined by microsatellites., Results: The Aachen minipig established here is based on the Mini-LEWE breed and consists of the Vietnamese potbelly pig, the Schwäbisch Hällisch Landpig, the German Landrace, and the Minnesota minipig. Relative organ weights (lung, heart, kidneys, brain), hematology (hemoglobin, hematocrit, platelet count, mean corpuscular hemoglobin concentration, segmented neutrophils, lymphocytes, eosinophils, basophils), and clinical chemistry parameters (sodium, calcium, chloride, alkaline phosphatase, aspartate aminotransferase, alanine aminotransferase, gamma-glutamyl transferase, lactate dehydrogenase, triglycerides, blood urea nitrogen, creatinine, total bilirubin, total protein, creatine kinase) of the Aachen minipigs and the Göttingen minipigs were not significantly different. Significant differences where only seen in relative organ weights (liver, spleen), hematology (red blood cell count, mean corpuscular volume, mean corpuscular hemoglobin, white blood cell count, banded neutrophils, monocytes), and clinical chemistry parameters (inorganic phosphorus, potassium, glucose, cholesterol, albumin, amylase)., Conclusion: The Aachen minipig is a suitable model for research due to its similarity to other minipig breeds, especially the Göttingen minipig. The reference values established in this study may be used for the comparison of scientific data and encourage the use of the Aachen minipig as an animal model for biomedical research., (© 2017 S. Karger AG, Basel.)

Background/aims: Chronic organ donor shortage has led to the consideration to expand the donor pool with livers from non-heart-beating donors (NHBD), although a higher risk of graft dys- or nonfunction is associated with these livers. We examined the effects of selective cyclooxygenase-2 (COX-2) inhibition on hepatic warm ischemia (WI) reperfusion (I/R) injury of NHBD., Methods: Male Wistar rats were used as donors and meloxicam (5 mg/kg body weight) was administered into the preservation solution. Livers were excised after 60 min of WI in situ, flushed and preserved for 24 h at 4°C. Reperfusion was carried out in vitro at a constant flow for 45 min. During reperfusion (5, 15, 30 and 45 min), enzyme release of alanine aminotransferase and glutamate lactate dehydrogenase were measured as well as portal venous pressure, bile production and oxygen consumption. The production of malondialdehyde was quantified and TUNEL staining was performed. Quantitative PCR analyzed COX-2 mRNA. COX-2 immunohistochemistry and TxB(2) detection completed the measurements., Results: Meloxicam treatment led to better functional recovery concerning liver enzyme release, vascular resistance and metabolic activity over time in all animals. Oxidative stress and apoptosis were considerably reduced., Conclusion: Cold storage using meloxicam resulted in significantly better integrity and function of livers retrieved from NHBD. Selective COX-2 inhibition is a new therapeutic approach achieving improved preservation of grafts from NHBD., (Copyright © 2011 S. Karger AG, Basel.)

Background: To elaborate the impact of new haemostatic agents we developed an instrument for the pressure-controlled induction of blunt liver injuries in a porcine animal model., Materials and Methods: A dilutional coagulopathy of 80% of animal blood volume was induced in 9 anaesthetized pigs. Animals were randomly assigned to be injured with a force of 112 Newton (N) (n = 1), 224 +/- 19 N (n = 4) or 355 +/- 35 N (n = 4). The impact of injury was measured by blood loss, survival time and coagulation parameters. Liver histology was obtained to evaluate the degree of liver injury., Results: The profound haemodilution resulted in a significant alteration of all coagulation parameters. After inflicting the injury with 355 +/- 35 N, both the survival time (30 +/- 9 min; p = 0.006) and blood loss (68 +/- 16 ml min(-1), p = 0.002) were significantly different as compared to injuries with 224 +/- 19 N (survival time: 76 +/- 20 min, blood loss: 23 +/- 4 ml min(-1)). In contrast, an injury with 112 N led to an insignificant blood loss of only 239 ml., Conclusion: We developed a pressure-controlled clamp that allows for the induction of blunt liver traumas with highly reproducible injuries with a positive correlation with blood loss and survival., (Copyright (c) 2009 S. Karger AG, Basel.)

Objective: To investigate the role of oxygen free radicals in the induction of apoptosis in non-heart-beating donor (NHBD) livers, and if superoxide dismutase (SOD) ameliorates these alterations., Methods: Rat livers were perfused via the portal vein with histidine/tryptophan/alpha-ketoglutarate solution from heart-beating donors (HBD) or 60-min warm ischemia from NHBD, with or without the addition of SOD. After 24 h, cold storage livers were evaluated by isolated reperfusion., Results: NHBD showed significantly higher enzyme leakage and elevated portal venous pressure (PVP) versus HBD. Bile and total adenine nucleotides (TAN) were significantly decreased. Apoptosis was prominent in sinusoidal lining cells, coupled with strong nitrotyrosine staining (NTR). The concentrations of nitric oxide and lipoperoxides were largely increased. SOD medication reduced hepatic enzyme release by 30% and lipoperoxides by nearly 50%. Apoptosis and NTR were significantly decreased, and PVP was strikingly reduced to normal values. A 3-fold enhancement in bile production and 1.5-fold increase in TAN of the liver tissue were also observed., Conclusion: NHBD livers are prone to severe reoxygenation injury promoted by oxygen free radicals, massive nitrite oxide production and peroxynitrite-induced apoptosis within the sinusoids. Antioxidant medication with SOD should be considered as a useful means of preserving NHBD livers., ((c) 2008 S. Karger AG, Basel.)

Background and Aims: The aim of this study was to analyze intestinal integrity after temporary abdominal wall repair with absorbable mesh., Methods: Rats underwent abdominal wall repair with absorbable mesh or sham operation. Myeloperoxidase-positive cells in the intestinal muscularis were histochemically quantified. Intestinal transit was visualized 48 h after surgery. Local and systemic inflammatory response was measured with TNF-alpha and IL-6 ELISA as well as malondialdehyde (MDA) expression in serum and peritoneal fluid., Results: Neutrophil count of the intestinal muscularis revealed that infiltration in the mesh-implanted and in the mesh-free animals 48 h postoperatively was similar. Gastrointestinal transit was similarly unaffected 48 h after surgery, with or without mesh implantation. TNF-alpha, IL-6 and MDA concentration in serum and peritoneal fluid showed no significant differences between the two groups., Conclusion: Intestinal contractility and local and systemic inflammatory response remained unaffected. Therefore, absorbable mesh augmentation is a safe and reliable method for temporary repair of the abdominal wall without affecting the intestinal integrity., ((c) 2008 S. Karger AG, Basel.)

Purpose: The purpose of this study was to investigate the presence of lymphatic invasion detected by D2-40 immunostaining compared to conventional hematoxylin-eosin (HE) staining in primary colorectal cancer (CRC) and the development of focal new lymphangiogenesis and peritumoral lymphatic proliferation in relation to the tumor stages. Additionally, we analyzed the relation of peritumoral inflammatory reaction (PIR) to tumor stages in CRC. The identification of new categories of patients with high-risk CRC would be very helpful in improving treatment strategies and patient outcome especially in early CRC., Patients and Method: Biopsies were taken from 41 patients with colorectal adenocarcinomas at different stages of disease. Immunohistochemistry was performed on paraffin-embedded sections. First, the whole section was screened for the presence of lymphatic invasion and PIR with routine HE staining. After analysis of the HE-stained slides, the slides were destained and reused for immunohistochemistry with the D2-40 monoclonal antibody. D2-40-immunostained sections were screened for the presence of lymphatic invasion, the proliferation of lymphatic vessels and focally newly developed lymph vessels., Results: Using the D2-40 antibody for immunostaining, our results demonstrate a significantly higher detection (p < 0.05) of lymphatic vessel invasion compared to routine HE staining in primary CRC. 22% more patients with lymphatic vessel invasion could be identified compared to routine HE staining, especially in node-negative tumor stage (UICC II). The positive predictive value of lymphatic invasion evaluated by D2-40 immunostaining to predict lymph node metastasis is 92% (negative predictive value 81%). High PIR was shown in UICC stage I and II. These infiltrations were rarely seen in UICC stage III and were absent in UICC stage IV. Higher UICC tumor stage is associated with a higher rate of focally newly developed lymphatic vessels. In UICC stage I we found peritumoral lymphatic vessel proliferation only in one case (14%) and in UICC stage II no case was found. 47% of the cases in UICC stage III and 50% of the cases in UICC stage IV showed focal peritumoral lymphatic vessel proliferation., Conclusions: Immunostaining with D2-40 significantly increased the detection rate of lymphatic invasion compared to conventional HE staining in primary CRC. The D2-40 antibody specific for lymphatic endothelium cells has the potential for a prognostic marker in early stage CRC. Further prospective studies are necessary to evaluate the prognostic value of lymphatic invasion and the induction of tumor lymphangiogenesis and its role in human cancer progression., (Copyright (c) 2006 S. Karger AG, Basel.)

Background/aims: In an ovine meniscal repair model, the patellofemoral (PF) osteoarthritis due to a non-sutured tear or failed repair was investigated., Methods: A radial meniscus tear was either sutured with polydioxanone (PDS), with a slow degrading polylactide long-term suture(LTS) or left without treatment. Knee joint cartilage in the PF and medial compartment was evaluated compared to normal knees (healthy controls)., Results: Retropatellar osteoarthritis in the non-sutured and sutured animals was intense in contrast to the control knees after 6 months in all groups (p < 0.001), and after 12 months in the PDS group (p < 0.001), LTS group and non-sutured animals (p < 0.05)., Conclusion: Non-sutured meniscus tears and failed repair lead fast to intense PF osteoarthritis corresponding with tibial damage of the injured compartment.

Background and Aims: Postoperative ileus is a common and poorly understood problem of abdominal surgery. The aim of this study was to measure postoperative intestinal transit and to evaluate bowel wall perfusion by a novel in vivo indocyanine green (ICG)-fluorescence measurement following intestinal manipulation (IM)., Methods: Rats underwent a simple intestinal manipulation. Myeloperoxidase-positive cells in the muscularis were stained with the Hanker-Yates reaction and quantified histochemically. Bowel wall perfusion was determined directly and 24 h postoperatively using a laser-fluorescence detection unit. Intestinal transit was visualized 24 h after IM., Results: IM resulted in a massive infiltration (155-fold) of neutrophils into the intestinal muscularis 24 h postoperatively. Bowel wall perfusion significantly decreased directly and 24 h following surgery (29 and 59%, respectively). Gastrointestinal transit was similarly impaired and showed a reduction to 40% of the control values 24 h after IM., Conclusion: IM of the rat small intestine caused an impairment in bowel wall perfusion and microcirculation and a significant decrease in gastrointestinal transit. The ICG fluorescence measurement using the described system proved to be a simple and reliable method to evaluate intestinal transit and bowel wall microcirculation in vivo., (Copyright 2004 S. Karger AG, Basel)

Background and Aims: Up to now, various tumor markers have been proposed for the detection of the onset of malignant cell transformation or the better follow-up of cancer patients. The aim of the present study is to investigate the diagnostic value of systemic lipid peroxidation as an additional evaluative tool in the follow-up of surgical patients with colorectal cancer in combination to the clinically routine tumor markers carcinoembryonic antigen (CEA) and carcinoantigen 19-9 (CA 19-9)., Patients and Methods: 36 patients with a colorectal carcinoma were included in this study. Blood samples were collected 1 day prior to the operation, 10 days and 1 year after the operation. Oxygen free radical mediated lipid peroxidation was determined by measurement of thiobarbituric acid-reactive substances in the same serum that were used for the determination of tumor markers., Results: Compared to control values, a highly significant increase of lipid peroxidation was found in the serum of all colorectal carcinoma patients up to the first 10 postoperative days. Differentiation of the patients, according to the T-stage, showed a marked and more obvious tendency towards higher serum lipid peroxides with increased tumor stage when compared to the conventional tumor markers. One year postoperatively the serum levels of lipid peroxidation returned to nearly normal values. Also the conventional tumor markers CEA and CA 19-9 showed a relative rise in the levels with the respective tumor stage, but differences were only statistically significant in the highest T-categories., Conclusion: After curative resection of the tumor, the level of systemic lipid peroxides decreases to normal values. We conclude from these results that the tumor is the primary cause of the increased systemic lipid peroxides., (Copyright 2002 S. Karger AG, Basel)

Cell injury in livers from non-heart-beating donors (NHBDs) is not only caused by necrosis, but it is increasingly being recognized that apoptotic transformation contributes to postischemic cell death. It remains unclear which pathways lead to apoptosis. We suggested that apoptosis in NHBD livers might be mediated by the Fas receptor. Therefore the aim of our study was the detection and quantification of the Fas receptor, Fas mRNA and apoptosis in NHBD livers. Livers of male Wistar rats were harvested either from heart-beating donors (control, n = 15) or 30 min after cardiac arrest from NHBDs (n = 15). All livers were stored in University of Wisconsin solution for 24 h at 4 degrees C, and reperfused using a recirculating model with oxygenated Krebs-Henseleit buffer for 120 min at 37 degrees C. Conventional signs of cell damage, such as enzyme release and bile production, showed an elevated nonspecific cell injury in NHBD livers. The immunohistochemical staining of Fas antigen expression revealed a 7% rate of Fas receptor-expressing hepatocytes in the control group, but a considerable increase up to 38% in the NHBD group. No Fas antigen expression was detected on sinusoidal endothelial cells. Real-time RT-PCR detected an approximately eightfold elevated concentration of Fas mRNA transcripts in NHBD livers. We conclude that upregulation of the Fas receptor on hepatocytes in NHBDs will prime these cells to eventually undergo apoptosis upon reperfusion in vivo. Therefore, therapeutic modulation of the Fas pathway must be considered as a new strategy in order to additionally protect NHBD livers which are otherwise prone to parenchymal apoptosis., (Copyright 2001 S. Karger AG, Basel)

Celsior, a low viscosity and low potassium preservation solution, has recently been tested successfully in the cold preservation of heart, lung, kidney and small intestine. The purpose of the present study was to evaluate the potential of Celsior in the cold preservation of the liver. Livers were harvested from male Wistar rats and then flushed with either Celsior (CE), University of Wisconsin solution (UW) or histidine-tryptophan-alpha-ketoglutarate solution (HTK) and stored for 24 h at 4 degrees C in the respective solution. The reperfusion was performed in vitro using a recirculating model with oxygenated (95% O(2), 5% CO(2)) Krebs-Henseleit buffer at 37 degrees C. To simulate the slow rewarming during the surgical implantation in vivo, all livers were stored for 30 min at room temperature prior to reperfusion. After ischemic storage and also after reperfusion some samples were freeze-clamped for analysis of tissue metabolites while others were tested for structural and functional integrity by the isolated perfusion. CE vs. UW vs. HTK: Metabolic preservation of tissue ATP (micromol/g dry weight) during cold storage was best with Celsior (0. 46 +/- 0.17 vs. 0.26 +/- 0.03 vs. 0.35 +/- 0.07; p < 0.05 CE vs. UW), but upon reperfusion energetic recovery was comparable in the three groups (3.45 +/- 0.66 vs. 4.27 +/- 0.41 vs. 3.63 +/- 0.64 micromol/g/dry weight). There appeared to be structural integrity during reoxygenation irrespective of the used preservation solution with comparable values of parenchymal enzyme release (ALT: 575 +/- 82 vs. 547 +/- 106 vs. 593 +/- 38 mU/g/l), bile production (18.0 +/- 1.0 vs. 18.5 +/- 2.5 vs. 18.7 +/- 1.4 microl/g/ min), and the release of acid phosphatase, an indicator for activated Kupffer cells (89 +/- 13 vs. 90 +/- 5 vs. 123 +/- 21 mU/g/l) in this in vitro model. Vascular flow characteristics were approximated by the portal perfusion pressure, which tended to be elevated upon initial reperfusion in the UW group (8.4 +/- 0.6 mm Hg) compared to 6.6 +/- 1.0 and 7.3 +/- 0.4 mm Hg in Celsior and HTK, respectively. However, the pressure values decreased to the normal range even in the UW group with ongoing perfusion. The sensitivity of our model in detecting protective effects of the tested solution was confirmed by a negative control group of livers stored in Ringer's solution at 4 degrees C, yielding an impaired recovery which differed by one magnitude from the three other groups. Within the limits of an in vitro study it is concluded from these results that Celsior may become a suitable alternative for liver preservation and further studies including a transplantation in vivo are strongly encouraged., (Copyright 2000 S. Karger AG, Basel)