The 3Ranker: An AI-based Algorithm for Finding Non-animal Alternative Methods.

The search for existing non-animal alternative methods for use in experiments is currently challenging because of the lack of both comprehensive structured databases and balanced keyword-based search strategies to mine unstructured textual databases. In this paper we describe 3Ranker, which is a fast, keyword-independent algorithm for finding non-animal alternative methods for use in biomedical research. The 3Ranker algorithm was created by using a machine learning approach, consisting of a Random Forest model built on a dataset of 35 million abstracts and constructed with weak supervision, followed by iterative model improvement with expert curated data. We found a satisfactory trade-off between sensitivity and specificity, with Area Under the Curve (AUC) values ranging from 0.85-0.95. Trials showed that the AI-based classifier was able to identify articles that describe potential alternatives to animal use, among the thousands of articles returned by generic PubMed queries on dermatitis and Parkinson's disease. Application of the classification models on time series data showed the earlier implementation and acceptance of Three Rs principles in the area of cosmetics and skin research, as compared to the area of neurodegenerative disease research. The 3Ranker algorithm is freely available at www.open3r.org; the future goal is to expand this framework to cover multiple research domains and to enable its broad use by researchers, policymakers, funders and ethical review boards, in order to promote the replacement of animal use in research wherever possible.

Let's do it right: Eight steps to competence in laboratory animal science in the European Union.

Demonstrated competence in laboratory animal science (LAS) is a prerequisite in Directive 2010/63/EU to work with animals used in scientific procedures, as it is essential to increase animal welfare, improve the quality of science, promote the acceptability of animal research and meet the demands of free movement of personnel and scientific exchange. Although since 2010 there have been eight clear steps to achieving the required competence of personnel working with animals used in science, it is not uncommon to see documentation for individuals who have just completed an LAS course that contains only education and training elements (three steps), for which the status of competence in LAS is granted. Here, a simplified summary of how competence in LAS should be delivered in eight steps according to EU recommendations is presented.

Urinary Excretion of Iohexol as a Permeability Marker in a Mouse Model of Intestinal Inflammation: Time Course, Performance and Welfare Considerations.

Intestinal permeability (IP) tests are used to assess intestinal damage in patients and research models. The probe iohexol has shown advantages compared to 51Cr-EDTA or absorbable/nonabsorbable sugars. During IP tests, animals are housed in metabolic cages (MCs) to collect urine. We examined the performance of an iohexol IP test in mice. Rag1-/- (C57BL/6) mice of both sexes were divided into controls or treatment groups, the latter receiving injections of effector/memory T cells to induce intestinal inflammation. After two, four and five weeks (W), a single dose of iohexol was orally administered. Urine was collected seven times over 24 h in MCs. Iohexol concentration was measured by ELISA. Intestinal histological damage was scored in duodenal sections. In control and treated mice of both sexes, urinary excretion of iohexol peaked at 4 h. From W2 to W4/W5, urinary iohexol excretion increased in treated mice of both sexes, consistent with development of duodenitis in this model. Positive correlations were observed between the urinary excretion of iohexol in W4/W5 and the histological severity of duodenitis in treated male mice. We conclude that a 6 h cumulative urine sample appears sufficient to evaluate small IP to iohexol in this mouse model, improving animal welfare by reducing cage periods.

Two-Week Aflibercept or Erlotinib Administration Does Not Induce Changes in Intestinal Morphology in Male Sprague-Dawley Rats But Aflibercept Affects Serum and Urine Metabolic Profiles.

Gastrointestinal toxicity is a frequently observed adverse event during cancer treatment with traditional chemotherapeutics. Currently, traditional chemotherapeutics are often combined with targeted biologic agents. These biologics, however, possess a distinct toxicity profile, and they may also exacerbate the adverse effects of traditional chemotherapeutics. In this study, we aimed to characterize the gastrointestinal and metabolic changes after a 2-week treatment period with aflibercept, an antiangiogenic VEGFR decoy, and with erlotinib, a tyrosine-kinase inhibitor. Male rats were treated either with aflibercept or erlotinib for 2 weeks. During the 2-week treatment period, the animals in the aflibercept group received two subcutaneous doses of 25 mg/kg aflibercept. The erlotinib group got 10 mg/kg of erlotinib by oral gavage every other day. The control groups were treated similarly but received either saline injections or oral gavage of water. Intestinal toxicity was assessed by measuring intestinal permeability and by histological analyses of intestinal tissues. Metabolic changes were measured with 1H nuclear magnetic resonance in serum and urine. Neither aflibercept nor erlotinib induced changes in intestinal permeability or intestinal tissue morphology. However, aflibercept treatment resulted in stunted body weight gain and altered choline, amino acid, and lipid metabolism. Two-week treatment with aflibercept or erlotinib alone does not induce observable changes in gastrointestinal morphology and function. However, observed aflibercept-treatment related metabolic changes suggest alterations in intestinal microbiota, nutrient intake, and adipose tissue function. The metabolic changes are also interesting in respect to the systemic effects of aflibercept and their possible associations with adverse events caused by aflibercept administration.

Influence of the intestinal microbiota on disease susceptibility in kittens with experimentally-induced carriage of atypical enteropathogenic Escherichia coli.

Typical enteropathogenic E. coli (tEPEC) carries the highest hazard of death in children with diarrhea and atypical EPEC (aEPEC) was recently identified as significantly associated with diarrheal mortality in kittens. In both children and kittens there is a significant association between aEPEC burden and diarrheal disease, however the infection can be found in individuals with and without diarrhea. It remains unclear to what extent, under what conditions, or by what mechanisms aEPEC serves as a primary pathogen in individuals with diarrhea. It seems likely that a combination of host and bacterial factors enable aEPEC to cause disease in some individuals and not in others. The purpose of this study was to determine the impact of aEPEC on intestinal function and diarrhea in kittens following experimentally-induced carriage and the influence of a disrupted intestinal microbiota on disease susceptibility. Results of this study identify aEPEC as a potential pathogen in kittens. In the absence of disruption to the intestinal microbiota, kittens are resistant to clinical signs of aEPEC carriage but demonstrate significant occult changes in intestinal absorption and permeability. Antibiotic-induced disruption of the intestinal microbiota prior to infection increases subsequent intestinal water loss as determined by % fecal wet weight. Enrichment of the intestinal microbiota with a commensal member of the feline mucosa-associated microbiota, Enterococcus hirae, ameliorated the effects of aEPEC experimental infection on intestinal function and water loss. These observations begin to unravel the mechanisms by which aEPEC infection may be able to exploit susceptible hosts.

Chemotherapy-induced gastrointestinal toxicity is associated with changes in serum and urine metabolome and fecal microbiota in male Sprague-Dawley rats.

PURPOSE: Chemotherapy-induced gastrointestinal toxicity (CIGT) is a complex process that involves multiple pathophysiological mechanisms. We have previously shown that commonly used chemotherapeutics 5-fluorouracil, oxaliplatin, and irinotecan damage the intestinal mucosa and increase intestinal permeability to iohexol. We hypothesized that CIGT is associated with alterations in fecal microbiota and metabolome. Our aim was to characterize these changes and examine how they relate to the severity of CIGT. METHODS: A total of 48 male Sprague-Dawley rats were injected intraperitoneally either with 5-fluorouracil (150 mg/kg), oxaliplatin (15 mg/kg), or irinotecan (200 mg/kg). Body weight change was measured daily after drug administration and the animals were euthanized after 72 h. Blood, urine, and fecal samples were collected at baseline and at the end of the experiment. The changes in the composition of fecal microbiota were analyzed with 16S rRNA gene sequencing. Metabolic changes in serum and urine metabolome were measured with 1 mm proton nuclear magnetic resonance (1H-NMR). RESULTS: Irinotecan increased the relative abundance of Fusobacteria and Proteobacteria, while 5-FU and oxaliplatin caused only minor changes in the composition of fecal microbiota. All chemotherapeutics increased the levels of serum fatty acids and N(CH3)3 moieties and decreased the levels of Krebs cycle metabolites and free amino acids. CONCLUSIONS: Chemotherapeutic drugs, 5-fluorouracil, oxaliplatin, and irinotecan, induce several microbial and metabolic changes which may play a role in the pathophysiology of CIGT. The observed changes in intestinal permeability, fecal microbiota, and metabolome suggest the activation of inflammatory processes.

Mice exposed to infant formula enriched with polyamines: impact on host transcriptome and microbiome.

Previous studies using a BALB/cOlaHsd model have shown the impact that the supplementation of infant formula with polyamines has on the modulation of microbial colonization and immune system development. To contribute to deciphering and identifying new complex interactions underlying the host response to polyamines, a systems biology approach integrating data from microbiota along the gastrointestinal tract, lymphocyte populations and immune system gene expression analysis of a lactating mice model fed different diets was carried out. The study design included four different dietary regimens including the following: mice fed by normal lactation; early weaned mice given commercial infant formula; and early weaned mice fed with infant formula enriched with two different concentrations of polyamines. Cluster analysis by principal component analysis and heat map demonstrated that the bacterial communities and immune system status differed between groups. The assessment of the relationship between immune system development, microbiota succession and polyamine supplementation in a global manner proved that the supplementation of infant formula with polyamines promotes similar microbial communities along the whole gastrointestinal tract, and results in similar lymphocyte populations and expression of immune related-genes to those with the normal lactated milk and the results differ from those with the infant formula without polyamines. Further studies should be conducted in human subjects to verify the current results, as the supplementation of polyamines may resemble the effect of natural breastfeeding practices in the gastrointestinal microbiota and immune system development in a mouse model.

Transglutaminase 2-specific coeliac disease autoantibodies induce morphological changes and signs of inflammation in the small-bowel mucosa of mice.

Coeliac disease is hallmarked by an abnormal immune reaction against ingested wheat-, rye- and barley-derived gluten and the presence of transglutaminase 2 (TG2)-targeted autoantibodies. The small-bowel mucosal damage characteristic of the disorder develops gradually from normal villus morphology to inflammation and finally to villus atrophy with crypt hyperplasia. Patients with early-stage coeliac disease have TG2-autoantibodies present in serum and small-intestinal mucosa and they may already suffer from abdominal symptoms before the development of villus atrophy. Previously, we have shown that intraperitoneal injections of coeliac patient-derived sera or purified immunoglobulin fraction into mice induce a condition mimicking early-stage coeliac disease. In the current study, we sought to establish whether recombinantly produced patient-derived TG2-targeted autoantibodies are by themselves sufficient for the development of such an experimentally induced condition in immune-compromised mice. Interestingly, mice injected with coeliac patient TG2-antibodies had altered small-intestinal mucosal morphology, increased lamina propria cellular infiltration and disease-specific autoantibodies deposited in the small bowel, but did not evince clinical features of the disease. Thus, coeliac patient-derived TG2-specific autoantibodies seem to be sufficient for the induction of subtle small-bowel mucosal alterations in mice, but the development of clinical features probably requires additional factors such as other antibody populations relevant in coeliac disease.

Intestinal permeability to iohexol as an in vivo marker of chemotherapy-induced gastrointestinal toxicity in Sprague-Dawley rats.

PURPOSE: Gastrointestinal toxicity is the most common adverse effect of chemotherapy. Chemotherapeutic drugs damage the intestinal mucosa and increase intestinal permeability. Intestinal permeability is one of the key markers of gastrointestinal function and measuring intestinal permeability could serve as a useful tool for assessing the severity of chemotherapy-induced gastrointestinal toxicity. METHODS: Male Sprague-Dawley rats were injected intraperitoneally either with 5-fluorouracil (150 mg/kg), oxaliplatin (15 mg/kg) or irinotecan (200 mg/kg). Clinical signs of gastrointestinal toxicity were assessed daily by weighing the animals and by checking for diarrhea. After 48 h, intestinal permeability to iohexol was measured in vivo by giving the animals 1 ml of 647 mg/ml iohexol solution by oral gavage and collecting all the excreted urine for 24 h. All of the animals were euthanized 72 h after drug administration and tissue samples were harvested from the jejunum and colon. RESULTS: All chemotherapeutics caused significant body weight loss and diarrhea. Intestinal permeability to iohexol was also increased in all treatment groups and histological analysis revealed significant intestinal damage in both jejunum and colon. Iohexol permeability correlated with the severity of clinical signs of gastrointestinal toxicity and with acute colonic injury. CONCLUSIONS: Chemotherapeutic drugs, such as 5-fluorouracil, oxaliplatin, and irinotecan, increase intestinal permeability to iohexol. Measuring intestinal permeability to iohexol could provide a simple marker for assessing chemotherapy-induced gastrointestinal toxicity.

Urban farmers' markets: accessibility, offerings, and produce variety, quality, and price compared to nearby stores.

Most food-environment research has focused narrowly on select stores and restaurants. There has been comparatively less attention to non-storefront food sources like farmers' markets (FMs), particularly in urban communities. The objective of the present study was to assess FMs' potential contribution to an urban food environment in terms of specific foods offered, and compare FM accessibility as well as produce variety, quality, and price to that of nearby stores. Investigators conducted a detailed cross-sectional assessment of all FMs in Bronx County, NY, and of the nearest store(s) selling produce within a half-mile walking distance (up to two stores per FM). The study included 26 FMs and 44 stores. Investigators assessed accessibility (locations of FMs and stores relative to each other, and hours of operation for each), variety (the number and type of all food items offered at FMs and all fresh produce items offered at stores), quality (where produce items were grown and if they were organic), and price (including any sales prices or promotional discounts). Analyses included frequencies, proportions, and variable distributions, as well as mixed-effect regressions, paired t-tests, and signed rank tests to compare FMs to stores. Geographic information systems (GIS) allowed for mapping of FM and store locations and determining street-network distances between them. The mean distance between FMs and the nearest store selling fresh produce was 0.15 miles (range 0.02-0.36 miles). FMs were open substantially fewer months, days, and hours than stores. FMs offered 26.4 fewer fresh produce items on average than stores (p values <0.02). FM produce items were more frequently local and organic, but often tended toward less-common/more-exotic and heirloom varieties. FMs were more expensive on average (p values <0.001 for pairwise comparisons to stores) - even for more-commonplace and "conventional" produce - especially when discounts or sales prices were considered. Fully, 32.8% of what FMs offered was not fresh produce at all but refined or processed products (e.g., jams, pies, cakes, cookies, donuts, juice drinks). FMs may offer many items not optimal for good nutrition and health, and carry less-varied, less-common fresh produce in neighborhoods that already have access to stores with cheaper prices and overwhelmingly more hours of operation.

Injection of celiac disease patient sera or immunoglobulins to mice reproduces a condition mimicking early developing celiac disease.

UNLABELLED: Typical features of celiac disease are small-bowel villus atrophy, crypt hyperplasia, and inflammation which develop gradually concomitant with ingestion of gluten. In addition, patients have anti-transglutaminase 2 (TG2) autoantibodies in their serum and tissues. The aim of this study was to establish whether celiac disease can be passively transferred to mice by serum or immunoglobulins. Serum aliquots or purified immunoglobulins (Ig) were intraperitoneally injected into Hsd:Athymic Nude-Foxn1nu mice for 8 or 27 days. As mice do not have proper IgA transport from peritoneum to blood, sera with a high content of IgG class anti-TG2 antibodies from untreated IgA-deficient celiac patients were used. Mouse sera were tested for celiac disease-specific autoantibodies, and several tissues were analyzed for autoantibody deposits targeted to TG2. Morphological assessment was made of the murine small intestinal mucosa. Injection of celiac disease patient sera or total IgG led to a significant delay in weight gain and mild diarrhea in a subset of mice. The mice injected with celiac patient sera or IgG had significantly decreased villus height crypt depth (Vh/CrD) ratios and celiac disease-specific autoantibody deposits targeted to TG2 in several tissues, including the small intestine. None of these features were observed in control mice. We conclude that administration of IgA-deficient celiac disease patient serum or total IgG induces both deterioration of the intestinal mucosa and clinical features of celiac disease in mice. The experimentally induced condition in the mice injected with patient serum or IgG resembles early developing celiac disease in humans. KEY MESSAGE: Celiac disease patient sera or total IgG was injected into athymic mice. A significant delay in weight gain and mild diarrhea was observed. Mice evinced significantly decreased villus height crypt depth ratios. Celiac disease-specific autoantibody deposits were present in several tissues. The condition in mice resembles early stage celiac disease in humans.

Intestinal permeability measurements: general aspects and possible pitfalls.

INTRODUCTION: Disturbances of the gut barrier function have been related to a variety of diseases, including intestinal and extra-intestinal diseases. The intestinal permeability tests are considered useful tools for evaluating disease severity and to follow-up patients after a therapeutic intervention and indirectly assess barrier function. OBJECTIVE: The aims of this review were to highlight the possible factors underlying higher intestinal permeability and the clinical conditions that have been associated with this in different age range; and also provide some insight into methodological aspects. RESULTS AND DISCUSSION: Abnormal regulation of tight junction function is the main cause of altered intestinal barrier. The impaired barrier function results in higher permeation rates of administered probes through the intestinal mucosa. Lactulose and mannitol are one of the most commonly used probes. The innocuousness and easiness of intestinal permeability tests can be explored to expand the knowledge about the clinical situations in which intestinal barrier dysfunction can be an important feature. Many factors may influence the results of the test. Researchers and healthcare professionals should try to circumvent the possible pitfalls of the intestinal permeability tests to produce consistent evidences. The use of others markers of intestinal physiology may also contribute to understand the role of barrier function in different diseases.

Introducción: Alteraciones funcionales de la barrera intestinal se han relacionado con una variedad de enfermedades intestinales y también con enfermedades no intestinales. Las pruebas de permeabilidad intestinal son consideradas herramientas útiles para evaluar la gravedad de la enfermedad para el posterior seguimiento de los pacientes después de una intervención terapéutica. Objetivo: El objeto de esta revisión ha sido destacar los posibles factores que pueden estar asociados a una mayor permeabilidad intestinal y revisar condiciones clínicas que han sido asociadas en individuos de diferentes edades. También revisar ciertos aspectos metodológicos de las pruebas de permeabilidad intestinal. Resultados y discusión: Las uniones estrechas entre los enterocitos son las principales estructuras encargadas de la regulación de la barrera intestinal. Una alteración de éstas, resulta en una deficiencia en la permeabilidad intestinal y una mayor penetración de las sustancias marcadoras de permeabilidad intestinal. La lactulosa y el manitol son las sustancias marcadoras más utilizadas. La inocuidad y facilidad de los test de permeabilidad han sido de ayuda para explorar y ampliar el conocimiento de muchas condiciones clínicas en las que la disfunción de la barrera intestinal ha sido un sello distintivo. Muchos factores pueden influir en los resultados de los test de permeabilidad. Sin embargo, los investigadores y los clínicos han de tratar de eludir los posibles inconvenientes de las pruebas de permeabilidad intestinal para poder producir evidencias más consistentes. El uso de otras sustancias marcadoras de la fisiología intestinal también puede contribuir a comprender mejor el papel de la barrera intestinal en diferentes enfermedades.

Resembling breast milk: influence of polyamine-supplemented formula on neonatal BALB/cOlaHsd mouse microbiota.

Infant microbiota is influenced by numerous factors, such as delivery mode, environment, prematurity and diet (breast milk or formula). In addition to its nutritional value, breast milk contains bioactive substances that drive microbial colonisation and support immune system development, which are usually not present in infant formulas. Among these substances, polyamines have been described to be essential for intestinal and immune functions in newborns. However, their effect on the establishment of microbiota remains unclear. Therefore, the aim of the present study was to ascertain whether an infant formula supplemented with polyamines has an impact on microbial colonisation by modifying it to resemble that in breast-fed neonatal BALB/c mice. In a 4 d intervention, a total of sixty pups (14 d old) were randomly assigned to the following groups: (1) breast-fed group; (2) non-enriched infant formula-fed group; (3) three different groups fed an infant formula enriched with increasing concentrations of polyamines (mixture of putrescine, spermidine and spermine), following the proportions found in human milk. Microbial composition in the contents of the oral cavity, stomach and small and large intestines was analysed by quantitative PCR targeted at fourteen bacterial genera and species. Significantly different (P< 0·05) microbial colonisation patterns were observed in the entire gastrointestinal tract of the breast-fed and formula-fed mice. In addition, our findings demonstrate that supplementation of polyamines regulates the amounts of total bacteria, Akkermansia muciniphila, Lactobacillus, Bifidobacterium, Bacteroides-Prevotella and Clostridium groups to levels found in the breast-fed group. Such an effect requires further investigation in human infants, as supplementation of an infant formula with polyamines might contribute to healthy gastrointestinal tract development.

Celiac Disease-Specific TG2-Targeted Autoantibodies Inhibit Angiogenesis Ex Vivo and In Vivo in Mice by Interfering with Endothelial Cell Dynamics.

A characteristic feature of celiac disease is the presence of circulating autoantibodies targeted against transglutaminase 2 (TG2), reputed to have a function in angiogenesis. In this study we investigated whether TG2-specific autoantibodies derived from celiac patients inhibit angiogenesis in both ex vivo and in vivo models and sought to clarify the mechanism behind this phenomenon. We used the ex vivo murine aorta-ring and the in vivo mouse matrigel-plug assays to address aforementioned issues. We found angiogenesis to be impaired as a result of celiac disease antibody supplementation in both systems. Our results also showed the dynamics of endothelial cells was affected in the presence of celiac antibodies. In the in vivo angiogenesis assays, the vessels formed were able to transport blood despite impairment of functionality after treatment with celiac autoantibodies, as revealed by positron emission tomography. We conclude that celiac autoantibodies inhibit angiogenesis ex vivo and in vivo and impair vascular functionality. Our data suggest that the anti-angiogenic mechanism of the celiac disease-specific autoantibodies involves extracellular TG2 and inhibited endothelial cell mobility.

Urinary recovery of orally administered chromium 51-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in healthy adult male Beagles.

Objective-To provide values for gastrointestinal permeability and absorptive function tests (GIPFTs) with chromium 51 ((51)Cr)-labeled EDTA, lactulose, rhamnose, d-xylose, 3-O-methyl-d-glucose, and sucrose in Beagles and to evaluate potential correlations between markers. Animals-19 healthy adult male Beagles. Procedures-A test solution containing 3.7 MBq of (51)Cr-labeled EDTA, 2 g of lactulose, 2 g of rhamnose, 2 g of d-xylose, 1 g of 3-O-methyl-d-glucose, and 8 g of sucrose was administered intragastrically to each dog. Urinary recovery of each probe was determined 6 hours after administration. Results-Mean ± SD (range) percentage urinary recovery was 6.3 ± 1.6% (4.3% to 9.7%) for (51)Cr-labeled EDTA, 3.3 ± 1.1% (1.7% to 5.3%) for lactulose, 25.5 ± 5.0% (16.7% to 36.9%) for rhamnose, and 58.8% ± 11.0% (40.1% to 87.8%) for 3-O-methyl-d-glucose. Mean (range) recovery ratio was 0.25 ± 0.06 (0.17 to 0.37) for (51)Cr-labeled EDTA to rhamnose, 0.13 ± 0.04 (0.08 to 0.23) for lactulose to rhamnose, and 0.73 ± 0.09 (0.60 to 0.90) for d-xylose to 3-O-methyl-d-glucose. Median (range) percentage urinary recovery was 40.3% (31.6% to 62.7%) for d-xylose and 0% (0% to 0.8%) for sucrose. Conclusions and Clinical Relevance-Reference values in healthy adult male Beagles for 6 of the most commonly used GIPFT markers were determined. The correlation between results for (51)Cr-labeled EDTA and lactulose was not as prominent as that reported for humans and cats; thus, investigators should be cautious in the use and interpretation of GIPFTs performed with sugar probes in dogs with suspected intestinal dysbiosis.

Infant formula supplemented with polyamines alters the intestinal microbiota in neonatal BALB/cOlaHsd mice.

Polyamines play a critical role in the development of intestinal and immune systems during the infant breastfeeding period, but the effect of polyamines on the microbiota has not been reported. The aim of our study was to characterize the impact on the colonization pattern in neonatal BALB/cOlaHsd mice after supplementing an infant formula (IF) with a mixture of putrescine (PUT), spermidine (SPD) and spermine (SPM). A total of 48 pups (14 days old) were randomly assigned to 4-day intervention groups as follows: breast-fed (unweaned) pups (n=12); weaned pups (n=12) fed an infant formula (IF); weaned pups (n=12) fed an IF enriched with a low concentration of PUT, SPD and SPM (2.10, 22.05 and 38.00 µg/day, respectively); and weaned pups (n=12) fed with IF enriched with a high concentration of PUT, SPD and SPM (8.40, 88.20 and 152.00 µg/day, respectively) of polyamines in accordance with normal proportions found in human milk. Microbiota composition was analyzed by fluorescent in situ hybridization (FISH) with flow cytometry detection. Microbiota changes in formula-fed mice were significantly greater following supplementation with polyamines (P<.01). Bifidobacterium group bacteria, Akkermansia-like bacteria and Lactobacillus-Enterococcus group levels were higher in the groups fed infant formula supplemented with polyamines, resulting in even higher numbers of bacteria than in the breastfed pups. Our findings indicate that infant formulas enriched with polyamines may interact with gut microbiota, suggesting that further studies in human infants are required to assess the impact of polyamines on both growth and microbiota levels.

Comparison of 51chromium-labeled ethylenediamine tetra-acetic acid and iohexol as blood markers for intestinal permeability testing in Beagle dogs.

(51)Chromium-labeled ethylenediamine tetra-acetic acid ((51)Cr-EDTA) is the gold standard probe for assessing intestinal permeability (IP) in dogs, but exposure to radioactivity is a disadvantage. Iohexol is a safe contrast medium commonly used for medical imaging purposes and has been successfully applied more recently for the assessment of IP in animal models and humans. This study aimed at comparing (51)Cr-EDTA and iohexol as IP blood markers in dogs. A test solution containing (51)Cr-EDTA and iohexol was administered intragastrically to seven healthy laboratory Beagle dogs, and percentage recoveries in serum were calculated. The strong linear association (correlation, r=0.76 and linear regression, y=0.03+5.04x) between (51)Cr-EDTA and iohexol supports the potential usefulness of iohexol as an IP blood marker in dogs.

The 51-chromium-labeled ethylenediamine tetra-acetic acid intestinal permeability blood test in healthy Beagle dogs: a comparison between serum and plasma levels.

A 51-chromium-labeled ethylenediamine tetra-acetic acid ((51)Cr-EDTA) permeability blood test was validated as a method to assess damage to the small intestine in dogs. The test was performed by calculating various percentages from sera after an orally ingested dose solution. The aim of the current study was to determine whether the use of serum or plasma had any influence on the results of the test. A test solution with 3.7 megabecquerel (100 µCi) of (51)Cr-EDTA was delivered through an orogastric tube to 13 healthy laboratory Beagle dogs. From each dog, 2 concurrent blood samples were withdrawn from cephalic veins using clotting-factor activator tubes for serum and heparinized tubes for plasma. The samples (n  =  26) were taken at 3 and 5 hr after administration of the test solution. Percentages of the orally ingested dose were then calculated in serum and plasma, and their relationship was assessed using correlation analysis. The mean ± standard deviation percentages in serum and plasma after 3 hr were 0.85 ± 0.43% and 0.88 ± 0.49%, respectively, whereas respective percentages in serum and plasma after 5 hr were 0.78 ± 0.52% and 0.81 ± 0.51%. The combined correlation coefficient between the percentages from the sera and plasma samples was excellent (R  =  0.98). It was concluded that the (51)Cr-EDTA permeability test in blood may be performed using serum or plasma of dogs, and the choice between the 2 samples is one of convenience.

Small intestinal permeability and serum folate and cobalamin absorption after surgical construction of permanent jejunal fistulas in laboratory beagle dogs.

Permanent jejunal fistulas enable easy, noninjurious, repeated and direct administration to and collection from the small intestines of conscious laboratory dogs. This study aimed at identifying potential alterations in the small intestinal morphology and function of this canine model after the surgery required to establish the fistulas. Assays of serum folate and cobalamin and (51)Cr-EDTA permeability tests were performed before and 4 wk after experimental jejunoplasties in 14 laboratory beagle dogs. Serum folate concentrations (mean ± SD) before (12.22 ± 1.80 µg/L) and after (14.14 ± 1.70 µg/L) jejunal surgery were within reference ranges for healthy dogs, although folate concentrations were higher after surgery. The cobalamin concentrations and the 6-h urinary excretion of (51)Cr-EDTA before (573.50 ± 150.04 ng/L and 6.75 ± 1.56%, respectively) and after (496.71 ± 164.22 ng/L and 6.41 ± 1.10%) were normal for healthy dogs, and no significant differences between pre- and postsurgical values were detected. The findings of the present study indicate that the small intestinal vitamin absorption and permeability of laboratory beagle dogs with jejunal fistulas remains unimpaired.

Estimation of intestinal permeability in healthy dogs using the contrast medium iohexol.

BACKGROUND: Iohexol is a nonradioactive marker that has been used successfully to test intestinal permeability in humans with inflammatory bowel disease. There is evidence in dogs that iohexol shares a similar permeability pathway as (51)chromium-EDTA, the gold standard marker. OBJECTIVE: The objective of this study was to determine an optimal oral iohexol dosage for an intestinal permeability serum test (IPST) and to use the test to estimate intestinal permeability in healthy dogs. METHODS: Eight clinically healthy dogs free of gastrointestinal, liver, and pancreatic disease were used in the study. Dosages of 0.25, 0.5, 1.0, 2.0, and 4.0 mL/kg of Omnipaque-350 (iohexol) were administered to 2 dogs at weekly intervals. Iohexol concentration was determined in serum samples obtained hourly for 6 hours after administration by high-performance liquid chromatography. Using the optimal dosage, iohexol was administered to 8 dogs twice, 6-36 days (mean 10 days) apart, and coefficients of variation (CVs) for iohexol concentration were calculated. RESULTS: A dosage of 2.0 mL/kg was chosen as optimal for the IPST, based on ease of iohexol detection in serum, intestinal contrast, and clinical effects of iohexol. Following administration of this dose to healthy dogs, mean (+/-SD) serum iohexol concentrations were 8.74+/-4.38, 11.89+/-5.67, 12.40+/-5.47, 9.23+/-5.54, 7.61+/-5.13, and 5.27+/-2.67 microg/mL at 1, 2, 3, 4, 5, and 6 hours after iohexol administration, respectively. CVs between the 2 test days were 28-45%. CONCLUSIONS: Using the iohexol dosage established in this study, the iohexol IPST was easy to perform as a marker for intestinal permeability in dogs. Further studies to establish reference intervals and evaluate the diagnostic value of the iohexol IPST in dogs with gastrointestinal disease are warranted.