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Histological sections of the various transversely cut intestinal segments used for volume assessment (column a), and 2 mm diameter cores used for surface density assessment (column b). Notice the large Peyer's patch in the jejunum (arrow)
Source publication
In many pharmacological and toxicological studies knowledge about the intestinal absorption, which is dependent upon the
surface area of absorptive epithelia, is indispensible. Although mice are often used in such preclinical studies, very few
quantitative data about their intestinal surface area are available. Especially for locally acting candida...
Contexts in source publication
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... cores that were punched out of the intestinal wall were, however, randomly rotated along their vertical axis before embedding. 4 An 8 mm thick transverse section (Microm microtome HM 360, Prosan) was made of each transverse sample at uniform random position (UR section) (Figure 2a) and of each core at random position within that core (vertical uniform random section, VUR) ( Figure 2b). All sections were mounted on slides, stained with haematoxylin and eosin (Linear Stainer II, Sakura Finetek Europe BV, Zoeterwoude, The Netherlands), and examined with a motorized light microscope (Olympus BX 61, Olympus Belgium, Aartselaar, Belgium) linked to a digital camera (Olympus DP 50, Olympus Belgium). ...
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... cores that were punched out of the intestinal wall were, however, randomly rotated along their vertical axis before embedding. 4 An 8 mm thick transverse section (Microm microtome HM 360, Prosan) was made of each transverse sample at uniform random position (UR section) (Figure 2a) and of each core at random position within that core (vertical uniform random section, VUR) ( Figure 2b). All sections were mounted on slides, stained with haematoxylin and eosin (Linear Stainer II, Sakura Finetek Europe BV, Zoeterwoude, The Netherlands), and examined with a motorized light microscope (Olympus BX 61, Olympus Belgium, Aartselaar, Belgium) linked to a digital camera (Olympus DP 50, Olympus Belgium). ...
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... Cavalieri method was used to estimate the tissue volume of each intestinal segment. 5 For this stereological application a small number of UR sections (often 5 -10) have to be examined (Figure 2a). 6 The method- ology used was similar to that described by Casteleyn et al. 7 In brief, a point grid was uniform randomly placed on the histological sections and the number of grid points hitting the intestinal tissue was counted (Figure 3). ...
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... Surface area estimation. This stereological application requires the examination of a small number of VUR sections (Figure 2b). 6 The methodology used was similar to that described by Casteleyn et al. 9 A cycloidal grid was superim- posed on the histological views and the number of intersec- tions (¼crossings) of the cycloids with the epithelial surface were counted (Figure 4). ...
Citations
... Intestinal crypts are glandular structures located at the base of the gut lining. The mouse intestine comprises approximately D = 10 5 crypts [69], each harboring about 100 to 400 bacteria [70,71], and the human intestine comprises up to D = 10 7 crypts [72]. Second, lymph nodes may act as reservoirs of bacteria, especially as some antibiotics poorly permeate them [73]. ...
Bacterial populations often have complex spatial structures, which can impact their evolution. Here, we study how spatial structure affects the evolution of antibiotic resistance in a bacterial population. We consider a minimal model of spatially structured populations where all demes (i.e., subpopulations) are identical and connected to each other by identical migration rates. We show that spatial structure can facilitate the survival of a bacterial population to antibiotic treatment, starting from a sensitive inoculum. Specifically, the bacterial population can be rescued if antibiotic resistant mutants appear and are present when drug is added, and spatial structure can impact the fate of these mutants and the probability that they are present. Indeed, the probability of fixation of neutral or deleterious mutations providing drug resistance is increased in smaller populations. This promotes local fixation of resistant mutants in the structured population, which facilitates evolutionary rescue by drug resistance in the rare mutation regime. Once the population is rescued by resistance, migrations allow resistant mutants to spread in all demes. Our main result that spatial structure facilitates evolutionary rescue by antibiotic resistance extends to more complex spatial structures, and to the case where there are resistant mutants in the inoculum.
... The heart, lungs, liver, kidneys, spleen, and small intestine were then immediately removed. The intestines were cleared of fecal content (retained for analysis) and cut into their individual components (duodenum, jejunum, and ileum) for collection using estimated lengths from previous publications (Casteleyn et al, 2010). All organs and tissues collected were pat-dried, weighed, and flash-frozen using liquid nitrogen and stored at À20 C. ...
... Hydrogel scaffolds have been generated previously for intestinal epithelial organoid cultures to mimic the crypt-villus architectures, which instruct the epithelial stem cells to generate cell type patterns reminiscent of the native tissues [15][16][17][18][19][20] . Similarly, we used PDMS stamps to shape the surface of the hydrogel scaffolds in the transgel devices to resemble the in vivo architecture of epithelial monolayers from various GI tissues (Fig. 2a,b) [22][23][24] . For stomach, caecum and colon tissues, we used an array of crypts or glands of different depths, while for the small intestine, we included a villus domain ( Supplementary Fig. 2a). ...
Organoids for modelling the physiology and pathology of gastrointestinal tissues are constrained by a poorly accessible lumen. Here we report the development and applicability of bilaterally accessible organoid-derived patterned epithelial monolayers that allow the independent manipulation of their apical and basal sides. We constructed gastric, small-intestinal, caecal and colonic epithelial models that faithfully reproduced their respective tissue geometries and that exhibited stem cell regionalization and transcriptional resemblance to in vivo epithelia. The models’ enhanced observability allowed single-cell tracking and studies of the motility of cells in immersion culture and at the air–liquid interface. Models mimicking infection of the caecal epithelium by the parasite Trichuris muris allowed us to live image syncytial tunnel formation. The enhanced observability of bilaterally accessible organoid-derived gastrointestinal tissue will facilitate the study of the dynamics of epithelial cells and their interactions with pathogens.
... 79%, 14.22% to 15.81%, and 13.15% to 14.06%, respectively, within the duodenum segment. Absorption in the jejunum segment was higher compared to the duodenum and ileum segments. In this analysis, phenolics compounds ranged from 32.97% to 37.33%, flavonoids from 14.22% to 15.81%, and antioxidants from 13.15% to 14.06%.Casteleyn et al. (2010) outlined how the surface area of the absorption side epithelium affected intestinal absorption. The jejunum had a larger intestinal diameter and a greater microvilli surface area, which facilitated maximal absorption. The study byCervantes et al. (2020) examined the capacity for intestinal absorption of phenolic compounds in blueberries ...
Black glutinous rice (Oryza sativa var. glutinosa) tape fermented with various yeast, mold, and bacteria is often rich in phenolics compounds and can contribute positively to health through its antioxidants activity. Despite the potential, these compounds have limited bioavailability value due to their structure, degree of glycosylation or polymerization, and interactions with other components. Therefore, this study aims to determine the effect of fermentation on bioavailability and bioaccessibility of phenolics compounds in black glutinous rice tape. During the procedures, cooked black glutinous rice was inoculated with ragi tape for 72 hours. Sampling was then performed every 24 hours to analyze bioaccessibility of phenolics compounds, flavonoids, and antioxidants activity. Subsequently, absorption was carried out using an everted gut sac model. The results showed that phenolics compounds were released from the food matrix during gastric and small intestine digestion. Fermentation was shown to increase the content of accessible phenolics compounds from 19.89% to 27.31%, flavonoids from 68.88% to 81.72%, and antioxidants activity from 13.56% to 22.89%. During fermentation, the highest increments were obtained after 72 hours, with 27.31% for total phenolics compounds, 81.72% for flavonoid compounds, and 22.89% for antioxidants activity. The products obtained after 72 hours of fermentation exhibited significantly highest absorption, but no significant differences were observed between the duodenum and ileum segments. The absorption of these compounds in the jejunum from the extract was significantly higher in fermented samples. Therefore, fermentation significantly enhanced bioavailability of phenolics compounds in black glutinous rice tape.
... Despite the similar general anatomy of mice and humans, the structure of the gastrointestinal tract remains considerably distinct. The proportionally larger colon, taller intestinal villi and cecum surface area in mice allow a subsequently larger microbial flora than in humans [52][53][54]. Moreover, the effects of FMT are likely to occur via a pleiotropic mechanism, one feature of which is the alteration of microbe-associated metabolites [55]. ...
Background
Dysbiosis of the microbiome is a key hallmark of polycystic ovary syndrome (PCOS). However, the interaction between the host and microbiome and its relevance to the pathogenesis of PCOS remain unclear.
Methods
To evaluate the role of the commensal gut microbiome in PCOS, we gavaged germ-free mice with the fecal microbiota from patients with PCOS or healthy individuals and evaluated the reproductive endocrine features of the recipient mice.
Results
Mice transplanted with fecal microbiota from PCOS patients and those transplanted from healthy controls presented different bacterial profiles and reproductive endocrine features. The fecal microbiota of the mice in the PCOS group was enriched in Phocaeicola, Mediterraneibacter, Oscillospiraceae, Lawsonibacter and Rikenellaceae. Fecal microbiota transplantation (FMT) from PCOS patients induced increased disruption of ovarian functions, lipo-metabolic disturbance, insulin resistance and an obese-like phenotype in recipient mice.
Conclusion
Our findings suggest that the microbiome may govern the set point of PCOS-bearing individuals and that gut ecosystem manipulation may be a useful marker and target for the management of PCOS.
... For assessing the health risk from exposure to MNPs, which are defined as microplastic particles < 5 mm in diameter and nanoplastic particles < 100-1000 nm in diameter [4][5][6], it is absolutely necessary to obtain exact data on MNP biodistribution [7]. Hence, there is a need for further insights regarding absorption and distribution over the physical barriers of the organism (blood-brain barrier [8], intestinal barrier [9][10][11] and placenta [12,13]), bioaccumulation in the different organs [14,15] and vascular transport [15]. The influence of dose, period of exposure, particle size [1,7], correlation with an altered gut microbiota [16] and co-exposure with other microparticles, pharmaceutics or chemicals [1] on the uptake is highly relevant for MNP uptake studies. ...
There is a rising awareness of the toxicity of micro- and nanoplastics (MNPs); however, fundamental precise information on MNP-biodistribution in organisms is currently not available. X-ray fluorescence imaging (XFI) is introduced as a promising imaging modality to elucidate the effective MNP bioavailability and is expected to enable exact measurements on the uptake over the physical barriers of the organism and bioaccumulation in different organs. This is possible because of the ability of XFI to perform quantitative studies with a high spatial resolution and the possibility to conduct longitudinal studies. The focus of this work is a numerical study on the detection limits for a selected XFI-marker, here, palladium, to facilitate the design of future preclinical in vivo studies. Based on Monte Carlo simulations using a 3D voxel mouse model, the palladium detection thresholds in different organs under in vivo conditions in a mouse are estimated. The minimal Pd-mass in the scanning position at a reasonable significance level is determined to be <20 ng/mm² for abdominal organs and <16 μg/mm² for the brain. MNPs labelled with Pd and homogeneously distributed in the organ would be detectable down to a concentration of <1 μg/mL to <2.5 mg/mL in vivo. Long-term studies with a chronic MNP exposure in low concentrations are therefore possible such that XFI measurements could, in the future, contribute to MNP health risk assessment in small animals and humans.
... A novel spatial transcriptomics approach called spatial enhanced resolution omics-sequencing, utilizes DNA nanoball-patterned arrays with spots 220 nm in diameter, and a center-to-center distance of 500-715 nm, enabling subcellular resolution 7 . While spatial transcriptomics techniques enable the in situ detection of transcripts within the tissue to even subcellular resolution, the size of the capture areas does not allow the analysis of large pieces or even entire tissues, such as the adult murine intestine (small and large intestine combined), which can be ~50-55 cm in length 8 . ...
... The murine GI tract is divided into four parts, each rolled accordingly: the upper GI tract (oronasal mucosa, esophagus, until the corpus of the stomach), proximal SI (upper half), distal SI (lower half) and the colon (Fig. 1). While exact delineations for the anatomical regionalization of the murine SI remain elusive, microanatomical characteristics have been used to estimate a duodenum/jejunum/ileum distribution of ~15.9%/74.3%/9.7% of the total SI length 8 . Applying these ratios to our protocol, when rolling the proximal SI starting from the distal section, the duodenum occupies the outermost ~31.8% of the roll, leaving the jejunum in the remaining In silico analysis ...
Tissues are dynamic and complex biological systems composed of specialized cell types that interact with each other for proper biological function. To comprehensively characterize and understand the cell circuitry underlying biological processes within tissues, it is crucial to preserve their spatial information. Here we report a simple mounting technique to maximize the area of the tissue to be analyzed, encompassing the whole length of the murine gastrointestinal (GI) tract, from mouth to rectum. Using this method, analysis of the whole murine GI tract can be performed in a single slide not only by means of histological staining, immunohistochemistry and in situ hybridization but also by multiplexed antibody staining and spatial transcriptomic approaches. We demonstrate the utility of our method in generating a comprehensive gene and protein expression profile of the whole GI tract by combining the versatile tissue-rolling technique with a cutting-edge transcriptomics method (Visium) and two cutting-edge proteomics methods (ChipCytometry and CODEX-PhenoCycler) in a systematic and easy-to-follow step-by-step procedure. The entire process, including tissue rolling, processing and sectioning, can be achieved within 2-3 d for all three methods. For Visium spatial transcriptomics, an additional 2 d are needed, whereas for spatial proteomics assays (ChipCytometry and CODEX-PhenoCycler), another 3-4 d might be considered. The whole process can be accomplished by researchers with skills in performing murine surgery, and standard histological and molecular biology methods.
... Since the absence of albumin in the basolateral chamber severely underestimated MTS permeability likely due to non-specific binding to the rapid equilibrium dialysis (RED) device membrane and plastic surfaces, apparent permeability values in the presence of albumin were used to calculate intestinal absorption rate constant. MTS absorption in the gastrointestinal tract (GIT) was given by first-order absorption rate constant (k a ), and the initial estimates for this value were obtained by in vitro-in vivo extrapolation (IVIVE) of apparent permeability using the following equation (23), k a = P app × 2/r, where r is the radius of the mouse intestine (24). MTS was highly accumulated in the MDCK monolayer cells as more than 65% of the drug dose was detected in the cells. ...
... The validity of oral-PBPK model predictions was initially tested using in-house-gener ated tissue concentration data obtained from oral administration of 10-mg/kg MTS to mice. The tissue samples collected at three different time points (8,24, and 48 hours) overlaid very well with oral PBPK model-simulated tissue data with a prediction error for AUC within 1.5-fold for all the tissues as shown in Fig. 2A and Table S3. Further verification of this model was done by comparing predictions against published in vivo data from an independent study in Leishmania-infected mice (27). ...
... Plasma was collected by centrifugation at 2,000× g at 4 °C for 15 min. The time points for blood collection for intravenously dosed mice were as follows: 0.0167, 0.083, 0.25, 0.5, 1, 2,4,8,12,24,48,72,120, and 168 hours, and those for orally dosed mice were as follows: 0.5, 1, 2, 3,4,6,8,12,24,48,72,120, and 168 hours. Tissues (liver, spleen, lung, kidney, and bone marrow) were collected at three different time points (8,48, and 168 hours). ...
Miltefosine (MTS) is the only approved oral drug for treating leishmaniasis caused by intracellular Leishmania parasites that localize in macrophages of the liver, spleen, skin, bone marrow, and lymph nodes. MTS is extensively distributed in tissues and has prolonged elimination half-lives due to its high plasma protein binding, slow metabolic clearance, and minimal urinary excretion. Thus, understanding and predicting the tissue distribution of MTS help assess therapeutic and toxicologic outcomes of MTS, especially in special populations, e.g., pediatrics. In this study, a whole-body physiologically-based pharmacokinetic (PBPK) model of MTS was built on mice and extrapolated to rats and humans. MTS plasma and tissue concentration data obtained by intravenous and oral administration to mice were fitted simultaneously to estimate model parameters. The resulting high tissue-to-plasma partition coefficient values corroborate extensive distribution in all major organs except the bone marrow. Sensitivity analysis suggests that plasma exposure is most susceptible to changes in fraction unbound in plasma. The murine oral-PBPK model was further validated by assessing overlay of simulations with plasma and tissue profiles obtained from an independent study. Subsequently, the murine PBPK model was extrapolated to rats and humans based on species-specific physiological and drug-related parameters, as well as allometrically scaled parameters. Fold errors for pharmacokinetic parameters were within acceptable range in both extrapolated models, except for a slight underprediction in the human plasma exposure. These animal and human PBPK models are expected to provide reliable estimates of MTS tissue distribution and assist dose regimen optimization in special populations.
... 13 Here, we determined the gut surface area of last-instar (L5d6) larvae compared to mice, for a corresponding oral dose conversions. 30 Finally, having previously characterized the M. sexta larval microbiome and revealed a bacterial community dominated by two species of enterococci, 16 we investigated the spatial pattern of bacterial colonization in the gut, mapping areas of high bacterial density. Our main findings are animated in Videos S1, S2, S3, S4, S5, S6, S7, S8, S9, and S10, which can be used as teaching and training resources for higher educational institutions and research organizations. ...
... The average midgut surface area value of M. sexta corresponds to approximately one-third of the surface area of the mouse intestine. 30 This iScience Article is impressive because the mouse intestine is more than 10 times longer. We also found that M. sexta lacks intestinal villi and has a lower density of microvilli compared to mammals. ...
... The microvillus surface area was calculated using the equation A = 2rpl as previously described. 30 To evaluate the augmentation of the intestinal surface area by microvilli (the MAF), we multiplied the density of microvilli (#/mm 2 ; Figure 7C) by the microvillus surface area (mm 2 ). To estimate the total surface area (with microvilli) for each specimen, the mean microvillus surface area was multiplied by the mean density of microvilli (#/qm 2 ). ...
The tobacco hornworm is a laboratory model that is particularly suitable for analyzing gut inflammation, but a physiological reference standard is currently unavailable. Here, we present a surface atlas of the healthy hornworm gut generated by scanning electron microscopy and nano-computed tomography. This comprehensive overview of the gut surface reveals morphological differences between the anterior, middle, and posterior midgut, allowing the screening of aberrant gut phenotypes while accommodating normal physiological variations. We estimated a total resorptive midgut surface of 0.42 m2 for L5d6 larvae, revealing its remarkable size. Our data will support allometric scaling and dose conversion from Manduca sexta to mammals in preclinical research, embracing the 3R principles. We also observed non-uniform gut colonization by enterococci, characterized by dense biofilms in the pyloric cone and downstream of the pylorus associated with pore and spine structures in the hindgut intima, indicating a putative immunosurveillance function in the lepidopteran hindgut.
... At higher concentrations, the viability of cells started to decrease rapidly, making 100 µg/mL the maximal biocompatible dose in vitro. Safe doses of DNase-NZ for in vivo application were separately calculated regarding both the presented cytotoxicity of the nanozyme and the surface area of the murine colon [49]. ...
... Control mice were only provided with drinking water for the entire duration, and untreated colitis mice were administered with PBS instead. Mesalamine was included in this study for comparison as a control medicine used in IBD treatment [49]. Throughout the study, changes in body weight were monitored daily and used as the primary indicator of colitis development (Fig. 3b). ...
Inflammatory bowel disease (IBD), including Crohn’s disease and ulcerative colitis, is a family of chronic disorders along the gastrointestinal tract. Because of its idiopathic nature, IBD does not have a fundamental cure; current available therapies for IBD are limited to prolonged doses of immunomodulatory agents. While these treatments may reduce inflammation, limited therapeutic efficacy, inconsistency across patients, and adverse side effects from aggressive medications remain as major drawbacks. Recently, excessive production and accumulation of neutrophil extracellular traps (NETs) also known as NETosis have been identified to exacerbate inflammatory responses and induce further tissue damage in IBD. Such discovery invited many researchers to investigate NETs as a potential therapeutic target. DNase-I is a natural agent that can effectively destroy NETs and, therefore, potentially reduce NETs-induced inflammations even without the use of aggressive drugs. However, low stability and rapid clearance of DNase-I remain as major limitations for further therapeutic applications. In this research, polymeric nanozymes were fabricated to increase the delivery and therapeutic efficacy of DNase-I. DNase-I was immobilized on the surface of polymeric nanoparticles to maintain its enzymatic properties while extending its activity in the colon. Delivery of DNase-I using this platform allowed enhanced stability and prolonged activity of DNase-I with minimal toxicity. When administered to animal models of IBD, DNase-I nanozymes successfully alleviated various pathophysiological symptoms of IBD. More importantly, DNase-I nanozyme administration successfully attenuated neutrophil infiltration and NETosis in the colon compared to free DNase-I or mesalamine.
