Simple Epithelium Research Articles

A case of uterine inclusion cysts in a sow

BackgroundSerosal inclusion cysts are thin walled-structures located on the peritoneal surface of the uterus, frequently observed as multiple cystic structures in aggregates or grape-like clusters containing a clear, non-viscous fluid. In human and veterinary medicine, they are thought to be developed under hormonal effects, or after manipulation or inflammation of the reproductive tract. However, they have not yet been described in swine.Case presentationA uterus of a 3-year-old crossbreed sow was condemned at slaughter due to the presence of multiples cystic cavities attached to the serosal surface. Microscopically, multiple cystic dilations emerging from the serosa were lined by a simple and flattened epithelium (cytokeratine positive and vimentin negative on immunohistochemistry) supported by a subepithelial layer of collagen. Grossly and histologically, they were diagnosed as serosal inclusion cysts.ConclusionTo the authors’ knowledge, this report represents the first description of serosal inclusion cysts in sows. These lesions should be taken into consideration within the differential diagnostic list of cystic peritoneal lesions such as cystic neoplasms, congenital cysts, and parasitic diseases.

Morphology of the cardiovascular system in greater rhea (Rhea americana americana Linnaeus, 1758)

Greater rheas have been the subject of scientific studies in the various areas of veterinary and biology in order to obtain essential information for their captivity management. The aim of this study was to describe the morphology of the greater rhea heart. The 20 animals were incised in sagittal plane, then fixed in 3.7% formaldehyde and dissected after 72 h. In addition, samples from the cardiovascular system were collected, processed for hematoxylin-eosin and Gomori Trichrome Staining. The heart is conical in shape, dark red when fresh and is located between the hepatic lobes. It has two atria and two ventricles, and four valves (left and right atrioventricular, aortic and pulmonary). The aorta and pulmonary trunk emerge at the heart base, while the ostia of the cranial and caudal vena cava emerged from the right atrium and the right and left pulmonary veins and the left coronary vein from the left atrium. From the aorta artery, the right and left coronary arteries arose, which originated, respectively, the superficial and conal branches and the profuse, left ventricular and superficial branches, being responsible for the irrigation of the heart. Microscopically the heart was constituted by simple pavement epithelium, rich in loose connective tissue. The aorta and pulmonary arteries were composed of the intima, middle and adventitial tunics. Thus, it is concluded that the morphological findings of greater rhea resemble those described for other birds such as ostrich and Gallus gallus domesticus.

Changes in marine turbot (Scophthalmus maximus) epidermis and skin mucus composition during development from bilateral larvae to juvenile flat fish.

Alike other flat fish, marine turbot has the particularity that changes from larvae with bilateral symmetry to adult with asymmetry, in terms of the position of the eyes. As expected, the skin configuration of this species is also affected by the development and transformation suffered by fish during metamorphosis. In this context, changes in the epidermis of marine turbot were studied using conventional staining and histochemical techniques using six lectins (UEA-I, PNA, RCA-I, WGA, Con A and SBA). During development from larvae to juvenile (3-300 days post-hatching), the epidermis increased in both thickness and the number of cell layers. In fact, the simple cuboidal epithelium observed in larvae at day 3 already became stratified at days 10-12, which sequentially increase in thickness with fish development. Turbot epidermis is composed basically of four cell types: epithelial and mucous or secretory cells that are present through the development, and pigmented cells and a type that the authors described as club-like cells that appear during and post-metamorphosis. The Alcian blue-periodic acid Schiff (AB-PAS) histochemical method revealed the presence of neutral glycoconjugates in mucous and club-like cells at post-metamorphic stages of fish. Accordingly, lectin analysis showed mucous cells containing glycoproteins rich in fucose (UEA-I labelling) and glycoconjugates rich in the sequence galactose-N-acetyl galactosamine (PNA and RCA-I labelling) when this cell type appears. Interestingly, melanophores were observed in the dorsal epidermis of post-metamorphic juveniles. This type of cell contains a black-to-brown pigment that provides the skin the typical colour of this fish species. Changes in mucous coat composition were observed during fish development, which was attributed to different roles of the glycoconjugates.

098 A burst of progenitor proliferation drives epidermal stratification

The formation of complex stratified epithelial barriers in mammals is essential for animal survival. During mouse embryonic development the skin epithelium is generated from a simple single-layered epithelium which stratifies and differentiates to form a multi-layered epidermis just before birth. But the mechanisms underlying epidermal stratification and how cells switch their cell fate from basal to suprabasal cells are still unknown. Recently, we proposed a two-phase model of epidermal stratification, with the first major phase starting around embryonic day E13.5 when the epithelium gets multi-layered.

Physical basis for the determination of lumen shape in a simple epithelium

The formation of a hollow lumen in a formerly solid mass of cells is a key developmental process whose dysregulation leads to diseases of the kidney and other organs. Hydrostatic pressure has been proposed to drive lumen expansion, a view that is supported by experiments in the mouse blastocyst. However, lumens formed in other tissues adopt irregular shapes with cell apical faces that are bowed inward, suggesting that pressure may not be the dominant contributor to lumen shape in all cases. Here we use live-cell imaging to study the physical mechanism of lumen formation in Madin-Darby Canine Kidney cell spheroids, a canonical cell-culture model for lumenogenesis. We find that in this system, lumen shape reflects basic geometrical considerations tied to the establishment of apico-basal polarity. A physical model incorporating both cell geometry and intraluminal pressure can account for our observations as well as cases in which pressure plays a dominant role.

Identifying Plectin Isoform Functions through Animal Models.

Plectin, a high-molecular-weight cytoskeletal linker protein, binds with high affinity to intermediate filaments of all types and connects them to junctional complexes, organelles, and inner membrane systems. In addition, it interacts with actomyosin structures and microtubules. As a multifunctional protein, plectin has been implicated in several multisystemic diseases, the most common of which is epidermolysis bullosa simplex with muscular dystrophy (EBS-MD). A great part of our knowledge about plectin’s functional diversity has been gained through the analysis of a unique collection of transgenic mice that includes a full (null) knockout (KO), several tissue-restricted and isoform-specific KOs, three double KOs, and two knock-in lines. The key molecular features and pathological phenotypes of these mice will be discussed in this review. In summary, the analysis of the different genetic models indicated that a functional plectin is required for the proper function of striated and simple epithelia, cardiac and skeletal muscle, the neuromuscular junction, and the vascular endothelium, recapitulating the symptoms of humans carrying plectin mutations. The plectin-null line showed severe skin and muscle phenotypes reflecting the importance of plectin for hemidesmosome and sarcomere integrity; whereas the ablation of individual isoforms caused a specific phenotype in myofibers, basal keratinocytes, or neurons. Tissue-restricted ablation of plectin rendered the targeted cells less resilient to mechanical stress. Studies based on animal models other than the mouse, such as zebrafish and C. elegans, will be discussed as well.

Adenomyomatous uterine polyp in a Miniature Pinscher: histologic, immunohistochemical, and clinical aspects.

A 14-y-old Miniature Pinscher bitch was admitted to a veterinary clinic because of inappetence and a distended abdomen; ultrasound examination revealed a fluid-filled uterus with a single 1-cm hyperechoic nodule in its lumen. Ovariohysterectomy was performed. Grossly, the uterine horns were distended irregularly and asymmetrically, and the uterine lumen contained 200-300 mL of brown watery fluid. A single white polypoid 0.9-cm diameter nodule was present at the site of the distended uterine horn and arose from the endometrium with a narrow stalk. Histologically, the polyp consisted of dense, smooth muscle fascicles admixed with glandular components; its surface was covered by simple cuboidal epithelium with areas of squamous metaplasia. The myomatous cells expressed the myogenic markers smooth muscle actin and desmin. We interpreted the mass as an adenomyomatous uterine polyp, which is a rare variant of an endometrial polyp.

Digestive tube of an herbivorous fish (Rhytiodus microlepis) from the Amazonian floodplain lakes: A morphological and histochemical study.

This study describes the morphology and histochemistry of the digestive tube of the herbivorous fish Rhytiodus microlepis, which is commonly found in the Amazonian floodplain lakes, Brazil. Thirty-eight fish were used in this study. The digestive tube was measured and dissected for anatomical description, and stained with (i) haematoxylin and eosin, for histological analyses; (ii) periodic acid-Schiff, for detected neutral mucins; and (iii) Alcian Blue (AB) pH 1.0 and 2.5 for acid and sulphated acid mucins. The oesophagus, with its secretory cells and taste buds, is adapted for lubrication of vegetable matter, resistance to friction and reception of stimuli. The stomach is U-shaped and rich in gastric glands, particularly in cardiac and fundic regions, which are adapted to receive large amounts of food, and promotes the digestion. The intestine comprises more than 70% of the digestive tube. All portions of the intestine, except the rectum, have the same pattern of mucosal folds, and the goblet cells reacted positively to all histochemical methods (PAS, AB 1.0 and 2.5), while rodlet cells reacted only to periodic acid-Schiff (PAS) staining. Neutral mucins and sulphated acid mucins predominated in the anterior portion of the intestine and a high concentration of carboxylated acid mucosubstances were present in the other portions. The rectum showed a strong reaction to all histochemical methods. The muscular layer of the intestine consists of three layers, which showed features presumably related to the rigid nature of the food. A simple squamous epithelium constitutes the serous layer over the entire length of the tube.

Ultrastructural characterization of the intestine of the Eurasian common moorhen using scanning electron microscopy and light microscopy.

The present investigation focused on the morphological features of the intestine of Eurasian common moorhen by the aid of scanning electron microscopy and histological, morphometric, and statistical examinations. The intestinal villi were varied in shape along the intestinal tract; the duodenal villi were elongated and twisted, the jejunal villi were tongue-like, the ileal villi were cuboidal, and the cecal villi were tongue-like and finger-like at the base and body of the cecum. While at the apex of the cecum, it appeared as corrugated longitudinal folds and the rectal villi appeared as columns. The microvilli were present as projections on the surface of villi of the small intestine and the base of the cecum. While at the body and the apex of the cecum, the microvilli appeared as threads and as brush hairs on the rectal villi. The duodenal, jejunal, ileal, cecal, and rectal villi were lined by simple columnar epithelium with goblet cells. The submucosal layer of small intestine consisted of connective tissue fibers along the intestinal tract, but it was absent at the base of the cecum. The tunica musculosa consisted of single longitudinal layer of smooth muscle fibers in the duodenum and rectum. While in the jejunum, ileum, and cecum, it was composed of single circular layer of smooth muscle fibers. The thickness of the tunics differed among the intestinal parts.

Histo-Morphology Study of the Respiratory Portion of Goat Lung (Capra Hircus) in Baghdad Province

The Histo-mrphology were directed on the pneumonic alveoli of 6 male goats. The respiratory portion is composed of typical cuboidal epithelial cells with Clara cell, however, alveolar ducts are lined by simple squamous epithelium and alveoli were generally circular structures that opened into the alveolar conduits and alveolar sacs or respiratory bronchioles. Alveoli were made out of two kinds of cells for example Type-I pneumocytes and Type-II pneumocytes. Previous framed the mainlining epithelial cells of alveoli which were squamous in sort having noticeable perinuclear territory and central found the core, while the last were cuboidal fit as a fiddle with the midway found core and periodically found among the Sort I cells in the alveolar epithelium. The lung pulmonary parenchyma was enveloped by the mesothelium (squamous epithelium) layer of visceral pleura.

Gross and Histomorphological Study of the Ovary and Oviduct of Turkey Hen with Especial Emphasis on the Sperm-Host Gland

Turkey bird is one of the popular poultry species which is reared primarily for meat production and considered as one of the major sources of animal protein. With such importance of this species, this study was designed to investigate the gross and histomorphology of the ovary and oviduct with especial emphasis on sperm-host glands of the turkey hen involving ten mature female turkeys (Meleagris gallopavo). The present study highlighted the distribution pattern of sperm-host glands (SHGs) in the oviduct of turkey hen that has a potential role in producing a fertile egg in poultry industries. The oviduct of turkey consists of the infundibulum, magnum, isthmus, uterus, and vagina which are sole distributors for making nutrition enriched egg. The tissue samples were collected from the ovary, different segments of the oviduct and especially uterovaginal junction (UVJ) and infundiomagnal junction of the oviduct. The ovaries and the oviducts were dissected and fixed in Bouins solution and processed for a light microscopic study. Histologically, the left ovary of turkey consisted of an outer cortex and inner medulla, with different stages of follicles. In all areas of the oviduct except the infundibulum and vagina, the tunica mucosa epithelium was lined with ciliated pseudo stratified columnar epithelium, and the lamina propria-submucosa contained branched tubular glands. Sperm-storage tubules were observed in the uterovaginal junction and infundibulo-magnum junction. These tubules were mostly branched, slightly coiled and extended into the lamina propria from the bases of the mucosal folds. These glands had proximal and distal parts; the proximal part was lined by pseudostratified columnar epithelium and distal part by non-ciliated simple columnar epithelium. The number of sperm host glands was more at uterovaginal junction than infundibulomagnal junction. The sperm-host glands might play a functional role in the storage and release of spermatozoa from the SHGs in response to oviposition or ovulation. The results would help poultry scientists and farmers in developing effective disease control and growth strategies.

A new microfluidic method enabling the generation of multi-layered tissues-on-chips using skin cells as a proof of concept

Microfluidic-based tissues-on-chips (TOCs) have thus far been restricted to modelling simple epithelia as a single cell layer, but likely due to technical difficulties, no TOCs have been reported to include both an epithelial and a stromal component despite the biological importance of the stroma for the structure and function of human tissues. We present, for the first time, a novel approach to generate 3D multilayer tissue models in microfluidic platforms. As a proof of concept, we modelled skin, including a dermal and an epidermal compartment. To accomplish this, we developed a parallel flow method enabling the deposition of bilayer tissue in the upper chamber, which was subsequently maintained under dynamic nutrient flow conditions through the lower chamber, mimicking the function of a blood vessel. We also designed and built an inexpensive, easy-to-implement, versatile, and robust vinyl-based device that overcomes some of the drawbacks present in PDMS-based chips. Preliminary tests indicate that this biochip will allow the development and maintenance of multilayer tissues, which opens the possibility of better modelling of the complex cell–cell and cell–matrix interactions that exist in and between the epithelium and mesenchyme, allowing for better-grounded tissue modelling and drug screening.

Comprehensive histochemical and stereological study of the parotid and sublingual salivary glands in Caucasian squirrel (Sciurus anomalus)

The present investigation tries to reflect histochemical and stereological properties of the parotid gland (PG) and sublingual gland (SLG) in the Caucasian squirrel. Totally, five male Caucasian squirrels were used. The glands were examind histochemical using PAS, Alcian blue (AB, pH = 2.5) and Aldehyde fucshin (AF) stainings. Total volume of the glands, acini, ducts as well as total length of ducts were estimated using streological procedures. The PG had a unique morphology and were connected to each other with an intermediated isthmus. The SLG was oval-shaped. Serous acini of PG exhibited strong, negative and weak reaction with AF, AB and PAS, respectively. While, mucous acini of SLG showed positive staining for AB and PAS, and negative staining for AF. The ductal system was consisted of intercalated (Id), striated (SD) and excretory ducts (Ed). The Sd in PG was lined with simple cuboidal to the columnar epithelium, while it was lined with simple cuboidal epithelium in SLG. The Ed was lined with stratified cuboidal epithelium in both glands. The striated duct was longest duct in both glands, the excretory and intercalated ducts were the shortest ones in PG and SLG, respectively. The maximum total volume in both gland were blonged to the acini and straited ducts. It concluded that PG and SLG in the Caucasian squirrel have some distinct structural properties in comparison to other rodents and mammalis species.

Scanning Electron Microscopic Studies on the Auricular and Atrio-ventricular Valvular Architecture of Pre-natal Non-descript Sheep

Background: Being the vital organ of circulatory system, the development of the heart before birth must be studied to safeguard the animal from the incidence of various developmental anomalies. The ultrastructural details of auricular and atrio-ventricular valvular architecture of heart especially in pre-natal sheep has not yet been reported. Methods: The collected foeti of sheep were divided into three age groups viz. early prenatal (up to 50 days), mid prenatal (51-100 days) and late prenatal (101 to 150 days). The samples of auricle, bicuspid and tricuspid valves were processed for scanning electron microscopic study (Scanning Electron Microscope, Make: Hitachi and Model: S-3400N) and subsequently, the samples were viewed and the photographs were taken in the facility available at Central Instrumentation Facility (CIF), OUAT, Bhubaneswar. The measurements of various parameters of auricles and valves were also taken at the ultrastructural level by the inbuilt software programming system. The recorded data were subjected to routine statistical analysis.Result: It was revealed that the endocardium was the inner layer of the auricles of heart. The endothelial surface of the auricles was occupied by the simple squamous epithelium. The endothelial cells were elongated in shape in all the age groups. The subendothelial layer was consisted of connective tissue fibers and conducting fibers. The pectinate muscles covered the inner side of the right and left atria and were interconnected having a network like appearance except in mid prenatal stage, i.e. at 96 days of gestation, where they were arranged linearly. There was presence of pores among the pectinate muscles in both the atria in all the age groups under study. The endothelial surface of the bicuspid or mitral and tricuspid valves was lined by simple squamous endothelium that projected into the lumen of the valve. There was presence of pores among the endothelial cells of the valves. Further, the subendothelial layer was present just below the endothelium and comprised of connective tissue fibers and conducting fibers in both the valves. The width of the fibers in bicuspid valve was not uniform and was further categorized into thick and thin fibers especially in the mid prenatal stage, i.e. at 96 days of gestation. There was presence of clusters of pores among the endothelial cells of the tricuspid valve in the heart especially in the late prenatal stage, i.e. at 120 days of gestation period.

Scanning Electron Microscopic Studies on the Ventricular Architecture of Pre-natal Non-descript Sheep

Background: Heart is the principal organ of circulatory system that pumps blood into the blood vessels and performs many vital functions. Studies on its development before birth of utmost important to safeguard the animal from the occurrence and consequences of various developmental anomalies. The ultrastructural details of ventricular architecture of heart especially in pre-natal sheep has not yet been reported. Methods: The collected foeti of sheep were divided into three age groups viz. early prenatal (up to 50 days), mid prenatal (51-100 days) and late prenatal (101 to 150 days). The samples from ventricles were processed for scanning electron microscopic study and subsequently, the samples were viewed and the photographs were taken in the facility available at Central Instrumentation Facility (CIF), OUAT, Bhubaneswar. The measurements of various parameters of ventricles were also taken at the ultrastructural level. The recorded data were subjected to routine statistical analysis. Result: It was observed that the endocardium of the ventricles consisted of a simple squamous epithelium. The endothelial cells were elongated in shape and arranged linearly on the surface of ventricles in 33 days prenatal non-descript sheep. The boundaries among the endothelial cells were indistinct in this age group. There was presence of pores among the endothelial cells on the surface of the ventricles. In late prenatal period, the endothelial cells of the ventricles became elongated in shape. The subendocardial layer consisted of connective tissue fibers and conducting purkinje fibers, which were quite predominant in the late prenatal period, i.e. at the age of 120 days of gestation. The endocardial fibers were distinctly coiled around the endothelial cells of the ventricles in this age group. The myocardium comprised of cylindrical and highly branched cardiac muscle fibers with pores all over the surface of the myocardium of the ventricles. Each muscle bundle in the myocardium consisted of muscle fibers extending parallel to each other longitudinally and that these fibers made collateral connections with each other in some regions. The papillary muscles were ridge like structures projecting into the lumen of the ventricles of heart. The chordae tendinae connected the papillary muscles and the bicuspid and tricuspid valves. The endothelial surface of the chordae tendinae consisted of elongated endothelial cells with pores among them. The pores of various sizes were arranged linearly in patches on the endothelial surface of the chordae tendinae of the ventricles especially in the late prenatal period, i.e. at about 105 days of gestation.

Histo-morphology of genitalia in crossbred dairy cows with kinked cervix

The study was conducted on genitalia collected from 100 dairy cows/heifers from the Meat Technology Unit, Mannuthy. The animals brought for slaughter at Meat Technology Unit, Mannuthy were from herds of five different farms (University and Government Undertaking farms) in Kerala state. This included six animals culled on account of factors other than infertility with normal reproductive system (control group) and the remaining animals with a known history of infertility. In total, seven animals showed kinked cervix condition. Cervix was evaluated morphometrically and histologically. Grossly, the cervix was hard, kinked and S-shaped, with a mean length of 9.64 ± 1.19 cm. Average number of annular rings in the cervical canal was 4.14 ± 0.26 with an average diameter of 1.74 ± 0.18 cm. At the external os, diameter of the cervix was less, while at the uterine end, diameter was more. The opening of each cervical ring showed a misalignment instead of a straight line. Histologically, the cervix was lined by simple columnar epithelium with signs of degeneration and desquamation. However, the submucosal layer was extensively infiltrated by collagen fibres. In uterus, there was a significant difference in the number of endometrial glands and height of the glandular epithelial cells which was less when compared to the control group. Muscular layer outer to connective tissue layer was thin and uneven. Alterations of the glandular structures negatively influence the viability of spermatozoa due to the lack of secretory products. This fibrous, collagen rich kinked cervix limits the smooth deposition of the semen into the uterus during artificial insemination and the insufficiently dilated cervix affects its contractibility leading to dystocia and subfertility.

Phase I experience with first in class TnMUC1 targeted chimeric antigen receptor T-cells in patients with advanced TnMUC1 positive solid tumors.

e14513 Background: MUC1 is a glycoprotein that is expressed in healthy tissues on the luminal surface of simple and glandular epithelium. In tumors that arise from these cells, an alternate form with aberrant glycosylation is frequently over expressed and distinguishes tumor associated TnMUC1 from normal MUC1. We have generated a novel chimeric antigen receptor (CAR) targeting the TnMUC antigen comprised of a mouse anti-human scFv derived from the monoclonal antibody 5E5 which recognizes the epitope comprising Tn glycan of MUC1, a CD8a transmembrane region and dual CD2 and CD3z intracellular signaling domains. CD2 signaling in T-cells has been demonstrated to result in delayed exhaustion. The novel incorporation of this co-stimulatory domain may lead to enhanced persistence of the CART cells which is believed to be critical for efficacy in solid-tumors. Methods: This is a multi-center first in human Phase I study to evaluate the safety and preliminary efficacy of CART-TnMUC1-Cells for the treatment of solid-tumors. Solid-tumors included in the dose-escalation phase include metastatic treatment-resistant ovarian cancer (OC), pancreatic adenocarcinoma (PC), triple-negative breast cancer (TNBC) or non-small lung cancer (NSCLC). All patients must have TnMUC1 expression as determined by immunohistochemistry. Results: As of January 2021, a total of six patients were treated. Three in Cohort 1 (no lymphodepletion; dose = 1-2 x 107 TDN CART cells; tumors = 1 OC, 1 TNBC and 1 PC) and 3 in Cohort 2 (flu/cy lymphodepletion; dose = 1-2 x 107 TDN CART cells; tumors = 1 NSCLC and 2 OC). None of the patients treated experienced DLT’s. The trial is currently enrolling to Cohort 3 (flu/cy lymphodepletion, 5-6 x 107 TDN). No CRS, neurotoxicity, serious adverse reactions and no on-target/off-tumor toxicity was observed at these dose levels. The most common AE’s were low-grade GI symptoms (e.g., nausea, abdominal pain) in 5/6 patients (83.3%), generalized disorders (e.g., chills, fatigue) in 5/6 (83.3%) and hematologic disorders (e.g., anemia, neutropenia) in 3/6 (50%) of patients. CAR expansion was demonstrated in all patients and was improved in Cohort 2 following LD chemotherapy. Preliminary efficacy assessed by RECIST v1.1 at Day +28 demonstrate SD in all patients in Cohort 2. Conclusions: This is the first report of a novel CART-TnMUC1 construct containing a CD2 co-stimulatory domain that has been used in clinical trials for the treatment of refractory solid-tumor malignancies. While the study is still early in dose-escalation having completed only 2 of 6 planned dose levels there is no evidence of safety concerns or on-target/off-tumor toxicity. Additional safety, efficacy and biomarker data is currently being reviewed and will be presented. Clinical trial information: NCT04025216.

The Intestinal Epithelium - Fluid Fate and Rigid Structure From Crypt Bottom to Villus Tip.

The single-layered, simple epithelium of the gastro-intestinal tract controls nutrient uptake, coordinates our metabolism and shields us from pathogens. Despite its seemingly simple architecture, the intestinal lining consists of highly distinct cell populations that are continuously renewed by the same stem cell population. The need to maintain balanced diversity of cell types in an unceasingly regenerating tissue demands intricate mechanisms of spatial or temporal cell fate control. Recent advances in single-cell sequencing, spatio-temporal profiling and organoid technology have shed new light on the intricate micro-structure of the intestinal epithelium and on the mechanisms that maintain it. This led to the discovery of unexpected plasticity, zonation along the crypt-villus axis and new mechanism of self-organization. However, not only the epithelium, but also the underlying mesenchyme is distinctly structured. Several new studies have explored the intestinal stroma with single cell resolution and unveiled important interactions with the epithelium that are crucial for intestinal function and regeneration. In this review, we will discuss these recent findings and highlight the technologies that lead to their discovery. We will examine strengths and limitations of each approach and consider the wider impact of these results on our understanding of the intestine in health and disease.

Anatomical and Histological Revision of Bulbourethral Gland in Reproductive System of Male Hamster

The anatomical consequences revealed that the bulbourethral glands in Syrian hamsters are in the form of a pair of small, oval-shaped glands and have a white color, similar to the fruit of a pea, each gland has a single duct that flows into the urethra, and these glands are buried under the cavernous bulbar muscle on both sides of the urethra. The long , wide and weigh were respectively about 0.7 cm and 0.4 cm and 1 g. Histopathological outcomes presented that the bulbourethral glands are a complex tubular-alveolar gland, lined with simple columnar epithelium, these glands are multi-lobed, each lobe consists of small simple alveoli that are connected to each other directly or through narrow and short tube. The goal of this study to know more anatomical and histological information for this gland for its significant and important role in the sexual reproduction process.

Modelling hereditary diffuse gastric cancer initiation using transgenic mouse-derived gastric organoids and single-cell sequencing.

Hereditary diffuse gastric cancer (HDGC) is a cancer syndrome caused by germline variants in CDH1, the gene encoding the cell-cell adhesion molecule E-cadherin. Loss of E-cadherin in cancer is associated with cellular dedifferentiation and poor prognosis, but the mechanisms through which CDH1 loss initiates HDGC are not known. Using single-cell RNA sequencing, we explored the transcriptional landscape of a murine organoid model of HDGC to characterize the impact of CDH1 loss in early tumourigenesis. Progenitor populations of stratified squamous and simple columnar epithelium, characteristic of the mouse stomach, showed lineage-specific transcriptional programs. Cdh1 inactivation resulted in shifts along the squamous differentiation trajectory associated with aberrant expression of genes central to gastrointestinal epithelial differentiation. Cytokeratin 7 (CK7), encoded by the differentiation-dependent gene Krt7, was a specific marker for early neoplastic lesions in CDH1 carriers. Our findings suggest that deregulation of developmental transcriptional programs may precede malignancy in HDGC. © 2021 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.