Luminal Projections Research Articles

Nonlinear biomechanics of diseased carotid arteries

The aim of this article is to analyse the nonlinear biomechanics of diseased carotid arteries as a potential tool for predicting the onset of cerebral strokes. A two-way coupled three-dimensional (3D) hyperelastic fluid-structure interaction (FSI) analysis of a diseased carotid artery with abnormal luminal projections at the carotid bulb known as carotid web (CaW) is conducted on the geometry of a patient artery, built upon employing CT angiography images. The blood-flow model incorporates non-Newtonian pulsatile turbulent fluid, and the artery wall is considered hyperelastic subject to blood-induced motion. The hemodynamics of artery induced by transient boundary conditions is determined, specifically focusing on shifts in crucial hemodynamic parameters such as wall shear stress (WSS) and alterations in the blood velocity pattern. Structural assessment of the artery wall involves quantifying the von Mises (VM) stress and deformation field. The analysis demonstrates that different CaW models result in different flow patterns for a selection of time steps in a cardiac cycle. The findings reveal that the presence of the web, as the most common disease among younger adults, can significantly influence the hemodynamic parameters and potentially accelerate the formation of thrombus and atherosclerosis. Hemodynamic analysis can potentially predict specific sites prone to plaque formation and rupture within the carotid artery.

Intravascular papillary endothelial hyperplasia in the lungs of a wild Korean raccoon dog.

A male Korean raccoon dog of unknown age was rescued and placed at the Daejeon Wildlife Rescue Center, Korea. Physical examination revealed severe emaciation and dehydration, as well as thick crusts and alopecia over most of the body. During medical care, the animal died and was submitted for postmortem examination. Firm, brown-red lesions of various sizes were observed on the surface of the lungs. In cross-sections of the lungs, pulmonary vessels were thickened and dilated, with white irregular papillary luminal projections. Histologically, pulmonary blood vessels were severely hyperplastic, characterized by thickened dilated walls and fibrous papillary projections covered with a single layer of endothelial cells (ECs). Hyperplastic fibrous connective tissue was confirmed by Masson trichrome staining. The ECs expressed CD31. We diagnosed the lesion as intravascular papillary endothelial hyperplasia, a unique non-neoplastic reactive process that has not been reported previously in pulmonary vessels of canids, equids, or felids, to our knowledge.

CALCIFYING ODONTOGENIC CYST OF THE MANDIBLE: CASE REPORT

Calcifying odontogenic cyst is a rare developmental odontogenic cyst and member of a group of ghost cell lesions of the jaw. We report a case of a 60-year-old man referred to the service with the main complaint of a painful swelling in the alveolar crest of the right mandibular body, with 4 years of evolution. Intraoral examination showed an increase in volume of rigid consistency and normal color. A well-defined unilocular radiolucency was observed in orthopantomography. Aspiration with 22-gauge needle revealed yellowish fluid content. Enucleation of the cyst was performed under local anesthesia. Histopathologic examination revealed a fragment of cystic lesion with a fibrous capsule lined by a variable-thickness epithelium with a well-defined basal layer of palisading columnar cells exhibiting focal accumulations of ghost cells with luminal projections, leading to the diagnosis of calcifying odontogenic cyst. The postoperative course was uneventful and the patient is in follow-up.

Rab35 controls formation of luminal projections required for bile canalicular morphogenesis.

Hepatocytes display a unique biaxial polarity with shared apical luminal connections between adjacent hepatocytes that merge into a network of bile canaliculi. Belicova et al. (2021. J. Cell Biol.https://doi.org/10.1083/jcb.202103003) discovered that hepatocyte apical membranes generate Rab35-dependent extensions that traverse the lumen and are essential for bile canalicular formation and maintenance.

LumNet

High-quality lighting positively influences visual performance in humans. The experienced visual performance can be measured using desktop luminance and hence several lighting control systems have been developed for its quantification. However, the measurement devices that are used to monitor the desktop luminance in existing lighting control systems are obtrusive to the users. As an alternative, ceiling-based luminance projection sensors are being used recently as these are unobtrusive and can capture the direct task area of a user. The positioning of these devices on the ceiling requires to estimate the desktop luminance in the user's vertical visual field, solely using ceiling-based measurements, to better predict the experienced visual performance of the user. For this purpose, we present LUMNET, an approach for estimating desktop luminance with deep models through utilizing supervised and self-supervised learning. Our model learns visual representations from ceiling-based images, which are collected in indoor spaces within the physical vicinity of the user to predict average desktop luminance as experienced in a real-life setting. We also propose a self-supervised contrastive method for pre-training LUMNET with unlabeled data and we demonstrate that the learned features are transferable onto a small labeled dataset which minimizes the requirement of costly data annotations. Likewise, we perform experiments on domain-specific datasets and show that our approach significantly improves over the baseline results from prior methods in estimating luminance, particularly in the low-data regime. LUMNET is an important step towards learning-based technique for luminance estimation and can be used for adaptive lighting control directly on-device thanks to its minimal computational footprint with an added benefit of preserving user's privacy.

Ovarian seromucinous tumors: clinicopathological features of 10 cases with a detailed review of the literature

BackgroundThe 2014 WHO Classification of ovarian neoplasms introduced a new entity of seromucinous tumors associated with endometriosis. These tumors encompassed a spectrum from benign to malignant and included seromucinous cystadenoma/ cystadenofibroma, seromucinous borderline tumor/atypical proliferative seromucinous tumor and seromucinous carcinoma. However, the 2020 WHO Classification of Female Genital Tumours removed seromucinous carcinomas as a distinct entity and recategorized them as Endometrioid carcinomas with mucinous differentiation. Here we describe clinico-morphologic features of seromucinous tumors recategorizing cases originally diagnosed as seromucinous carcinoma in light of 2020 WHO classification and present detailed review of literature.MethodsSlides of seromucinous tumors were reviewed. Special emphasis was given to evaluation of stromal invasion. Follow-up was obtained.ResultsTen cases were diagnosed. Mean age was 40 years. Four cases were bilateral. Mean size was 19 cm. Grossly; luminal papillary projections were seen in 6 cases. Tumors demonstrated a papillary architecture with papillae lined by stratified seromucinous epithelium showing nuclear atypia. Stromal invasion was seen in 4 cases. Six cases were reported as borderline seromucinous tumors and 4 cases originally diagnosed as seromucinous carcinoma were recategorized as endometrioid carcinoma with mucinous differentiation on review. Endometriosis was seen in 4 cases. CK7, PAX8 and ER were positive in 7/7 cases. Two cases showed extra-ovarian involvement. Follow up was available in 7 cases. Six patients were alive and well at follow up ranging from 8 to 46 months. Six patients received chemotherapy postoperatively. One patient with carcinoma died of disease 18 months postoperatively.ConclusionIn our series, 4 cases were originally diagnosed as seromucinous carcinomas. However, these were recategorized in light of the 2020 WHO Classification of Female Genital tumors as endometrioid carcinomas with mucinous differentiation. Six cases were diagnosed as seromucinous borderline tumors. Thus, majority of cases were borderline in agreement with published literature.

Optical safety of comparative theater projectors.

Traditional movie projectors employing carbon arcs were introduced to movie theaters more than a century ago, and they were replaced during the 1950s by xenon-arc projectors. Today, these arc-lamp film projectors are expected to be replaced by digital laser projectors. Questions have arisen with regard to safety of the new laser-based projectors and about the comparable safety to the xenon-arc projectors that they replace. Smaller projectors employing tungsten-halogen lamps have been used for decades in home and office environments, and small arc-discharge lamps more recently have enjoyed widespread use in digital projectors. The trend in digital projectors has led to increased luminance projection products. Results of a comparative evaluation of ocular hazards from various projection systems, with an emphasis on professional laser illuminated projection systems, are presented. Irradiance and source size measurements were made to determine the radiance of each of the projection systems for both thermal and blue light hazards to the retina. Ultraviolet and infrared measurements were also made for completeness of the hazard evaluation. Projectors are classified by risk groups according to national and international standards, and recommendations for projector safety are provided. It is shown that laser illuminated projectors have hazard distances comparable to traditional 35 mm movie-theater projectors of the order of 1 m. Since there is no resemblance to the optical hazards of distant, collimated laser beams in light shows and only minimal hazards are posed by theater projectors to the audience, the standards and regulations applicable to "laser light shows" should not be applicable for these types of products.

Helicobacter pylori directs tolerogenic programming of dendritic cells

Our laboratory has shown that Helicobacter pylori infection in mice triggers an increase in the number of subepithelial lamina propria CD11c+ dendritic cells with luminal projections. The physical characteristic of these cells is consistent with their ability to traverse epithelial tight junctions as reported by Maria Recigno (Recigno et al. Nature Immunology 2001; 2:361-7). Gastric CD103+ dendritic cells, which are known to induce mucosal regulatory T cells, were also increased in number, raising the question whether H. pylori infection induces a regulatory T cell-skewed response by way of a bacteria-dendritic cell interaction. In fact, bone marrow-derived dendritic cells underwent tolerogenic programming, skewing the balance between effector and regulatory T cell responses towards regulatory T cell differentiation in a transforming growth factor-β- and interleukin-10-dependent manner. Depletion of regulatory T cell numbers augmented H. pylori-specific effector helper T cell responses, which correlated with a lower degree of H. pylori colonization. These results suggest H. pylori is capable of inducing a regulatory T cell-skewed response that limits the host's ability to eradicate the bacteria, allowing the H. pylori infection to persist. To better understand the mechanism of H. pylori tolerogenic programming we compared the differential expressions of 34 genes critical for dendritic cell function in bone marrow-derived dendritic cells pulsed with live H. pylori or other gram-negative bacteria (e.g., Escherichia coli, Acinetobacter lwoffii). Our data imply that H. pylori targets the Toll-like receptor 2 pathway to induce a regulatory T cell-skewed response. In addition, we show that H. pylori-pulsed dendritic cells are capable of inducing the conversion of naïve T cells to regulatory T cells. These observations are evidence of a unique tolerogenic program in dendritic cells that involves active editing of the immune response by H. pylori, favoring its persistence in the gastric mucosa.

Heterochromatin Protein 1γ Epigenetically Regulates Cell Differentiation and Exhibits Potential as a Therapeutic Target for Various Types of Cancers

Heterochromatin protein 1 (HP1) is a chromosomal protein that participates in both chromatin packaging and gene silencing. Three HP1 isoforms (alpha, beta, and gamma) occur in mammals, but their functional differences are still incompletely understood. In this study, we found that HP1gamma levels are decreased during adipocyte differentiation, whereas HP1alpha and beta levels are expressed constitutively during adipogenesis in cultured preadipocyte cells. In addition, ectopic overexpression of HP1gamma inhibited adipogenesis. Furthermore, we did not detect any HP1gamma protein in the differentiated cells of various normal human tissues. These results suggest that the loss of HP1gamma is required for cell differentiation to occur. On the other hand, the methylation levels of lysine 20 (K20) on histone H4 showed a significant correlation with HP1gamma expression in both these preadipocyte cells and normal tissue samples. However, all cancer tissues examined were positive for HP1gamma but were often negative for trimethylated histone H4 K20. Thus, a dissociation of the correlation between HP1gamma expression and histone H4 K20 trimethylation may reflect the malfunction of epigenetic control. Finally, suppression of HP1gamma expression restrained cell growth in various cancer-derived cell lines, suggesting that HP1gamma may be an effective target for gene therapy against various human cancers. Taken together, our results demonstrate the novel function of HP1gamma in the epigenetic regulation of both cell differentiation and cancer development.

Stimulation of Glucagon Like Peptide-1 Secretion in Enteroendocrine L cells

GLP-1 (glucagon like peptide-1) is new anti-diabetic drug with a number of beneficial effects. It stimulates glucose dependant insulin secretion and restoration of beta cell mass through enhancement of islet mass. However, it is easily inactivated after being secreted from enteroendocrine L cells. Recent trial to increased GLP-1 is to directly stimulate L cells through its receptor located in the surface of L cell. Taste receptor in the apical surface of L cell is activated by various tastants contained in the food. Tongue perceives taste sense through the heterotrimeric G-protein (-gustducin) and its downstream signaling cascades. Same taste receptors are also expressed in enteroendocrine cells. In duodenal L cell, -gustducin was detected by immunofluorescence stainig at the luminal projections of enteroendocrine cells. And several other taste signaling elements were also found in L cells. Ingestion of sweet or bitter compounds revealed stimulation of GLP-1 secretion and the regulation of plasma insulin and glucose. In this review, I will briefly introduce the possibilities to stimulate GLP-1 secretion though the membrane receptor in enteroendocrine cell. And it will be the good candidate to develop the treatment modality for obesity, diabetes and abnormal gut motility.

Epithelial hedgehog signals pattern the intestinal crypt-villus axis

Morphological development of the small intestinal mucosa involves the stepwise remodeling of a smooth-surfaced endodermal tube to form finger-like luminal projections (villi) and flask-shaped invaginations (crypts). These remodeling processes are orchestrated by instructive signals that pass bidirectionally between the epithelium and underlying mesenchyme. Sonic (Shh) and Indian (Ihh) hedgehog are expressed in the epithelium throughout these morphogenic events, and mice lacking either factor exhibit intestinal abnormalities. To examine the combined role of Shh and Ihh in intestinal morphogenesis, we generated transgenic mice expressing the pan-hedgehog inhibitor, Hhip (hedgehog interacting protein) in the epithelium. We demonstrate that hedgehog (Hh) signaling in the neonatal intestine is paracrine, from epithelium to Ptch1-expressing subepithelial myofibroblasts (ISEMFs) and smooth muscle cells (SMCs). Strong inhibition of this signal compromises epithelial remodeling and villus formation. Surprisingly, modest attenuation of Hh also perturbs villus patterning. Desmin-positive smooth muscle progenitors are expanded, and ISEMFs are mislocalized. This mesenchymal change secondarily affects the epithelium: Tcf4/beta-catenin target gene activity is enhanced, proliferation is increased, and ectopic precrypt structures form on villus tips. Thus, through a combined Hh signal to underlying ISEMFs, the epithelium patterns the crypt-villus axis, ensuring the proper size and location of the emerging precrypt compartment.

Membranous fat necrosis in lipomas.

Membranous fat necrosis (MFN) is an under-recognized variant of fat necrosis (FN) that is characterized by the presence of membranocystic foci in which cysts are lined by an eosinophilic, homogeneous membrane with pseudo-papillary luminal projections. Although MFN has been described in systemic adipose tissue, it has not been described in lipomas. We report the rare occurrence of MFN in four lipomas. The lipomas ranged in size between 9 and 22 cm and occurred in menopausal women in the left shoulder, right upper back, right thigh, and gluteal regions. In two cases the membranocystic foci were identified macroscopically, whereas in the other two cases MFN was only identified on histologic assessment. Apart from the typical histologic appearance of the membranocystic foci, the membranes have a distinct histochemical profile that includes consistent Sudan black positivity and either periodic acid-Schiff or Ziehl-Neelsen positivity. In all cases, there was autofluorescence of the membranes on immunofluorescent examination of unstained sections. These membranocystic foci have the typical staining reactions of ceroid pigment. The exact cause of MFN in lipomas is not known, but in view of their large sizes, traumatic and ischemic etiologies are proposed.

Ultrastructure of the digestive system of adult Sanguinicola inermis

The alimentary tract of adult Sanguinicola inermis Plehn, 1905 (Digenea: Sanguinicolidae) was studied by transmission electron microscopy. A highly developed muscular region, likely to be a modified sucker, is present anteriorly to the oesophagus. The tegumental oesophagus, on the basis of the characteristics of the surface cytoplasm, is differentiated into anterior, median and posterior regions with the apical cytoplasm of the median oesophagus drawn into extracellular vesicles from which arise surface knobs. The oesophagus leads to a cellular intestine composed of a single layer of epithelial cells. The apical surface of the intestine is drawn into short luminal projections and the intestinal cells contain numerous organelles and secretory granules. No host cells or cell debris were evident within the alimentary tract, although the intestinal lumen was filled with electron-dense material.

Ultrastructural development of Kaposi's sarcoma in relation to the dermal microvasculature

Ultrastructural subtypes of endothelial cells in Kaposi's sarcoma were compared with lymphatics and the normal dermal microcirculation in different stages of lesional development. In the earliest patch stage, lymphatic channels, recognised by their dissecting growth pattern and a lack of a basal lamina and pericytes, were prominent. Venous endothelium was recognised by virtue of its multilaminated basal lamina and often showed markedly irregular luminal and abluminal cytoplasmic projections. As the histological stage progressed toward spindle cells, venous endothelium showed a tetrad of changes: dissolution of the basal lamina; fragmentation and disappearance of the pericyte sheath, decreased and often rudimentary intercellular junctions and markedly reduced numbers of Weibel-Palade bodies. These were also features of spindle cells, which were rarely seen to emerge from narrow vascular channels of indeterminate type. Spindle cells showed sparse intercellular junctions and minimal basal lamina but no Weibel-Palade bodies. These progressive venous alterations thus resulted in a mixed intermediate subtype of endothelium with the morphological traits resembling lymphatics as well as venous blood vessels. The mixed subtype included endothelial tubes surrounded by a complete basal lamina but lacking pericytes, and much more commonly, tubes with pericytes but a scanty basal lamina. Both forms had remarkably few or no Weibel-Palade bodies. In the spindle cell stage, normal vessels were largely replaced by the mixed subtype and an indeterminate type of frequently disrupted endothelial tube which lacked a basal lamina as well as a pericytic investment. Dissecting lymphatic channels could not be confidently distinguished from the latter vessels.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein lipase in myocytes and capillary endothelium of heart: immunocytochemical study

Lipoprotein lipase was immunolocalized by electron microscopy in hearts of young mice; 78% of lipoprotein lipase was in myocytes, 3-6% in extracellular space, and 18% in capillary endothelium. Lipoprotein lipase in myocytes was located primarily in sarcoplasmic reticulum, Golgi sacs, and transport vesicles and also in secretory vesicles at the cell periphery. Lipoprotein lipase in extracellular space was present near the orifice of secretory vesicles of myocytes and in narrow zones spanning the space between myocytes and capillary endothelium. The lowest concentration of lipase associated with endothelial cells was at the basal plasma membrane, whereas the highest concentration was at the surface of luminal projections. Lipoprotein lipase was associated with chylomicrons at the capillary surface but not with chylomicron remnants. Fasting mice for 48 h increased, in heart, lipoprotein lipase activity by 120% and immunolocalized lipase by 270%. The greatest increase (5-fold) occurred at the surface of intraluminal endothelial projections. The findings indicate that lipoprotein lipase in heart is synthesized by myocytes, transferred across extracellular space along cell surfaces and across endothelial cells via vesicles or intracellular channels, and concentrated at the surface of luminal projections of endothelium where the enzyme hydrolyzes triacylglycerol of chylomicrons and very low-density lipoproteins.

Ultrastructure of the neural component of the regenerating spinal cord in the tails of three species of New Zealand lizards (Leiolopisma nigriplantare maccanni,Lampropholis delicata, andHoplodactylus maculatum)

Abstract The regenerated spinal cords of all three species examined (Leiolopisma nigriplantare maccanni, Lampropholis delicata, Hoplodactylus maculatum) consisted of a monolayer of ependymal cells with interspersed axons and cellular processes lining the liquor-filled canalis centralis with its Reissner fibre in the centre. Cerebral spinal fluid contacting neurons (CSFCNs) were distinguishable from ependymal cells by their luminal projections, longer and thicker stereocilia (with well-developed cytoskeletal elements), overall greater electron translucency, and specific organelles like silver methenamine-positive dense granules. Silver methenamine-positive material was present also in the lumen. Vesicles, apparently rupturing, were noticed on the luminal face of the CSFCN. A secretory activity of the CSFCN is one likely function of vesicles. The similarity between CSFCNs and inner ear hair cells (as well as lateral line receptor cells) suggested another possible function, namely that of monitoring cerebros...

Vascular aspects and hemodynamic consequences of central nervous system injury.

We document here microvascular alterations occurring in models of mild, moderate, and severe cerebral ischemic injury. The relationship of the vascular abnormalities to the generation of hemodynamic alterations was also evaluated. Following periods of severe incomplete ischemia, scanning electron microscopic analysis of cerebral microvessels revealed the widespread production of cerebral endothelial microvilli. These microvilli increased in frequency as the ischemic insult was prolonged and remained prominent during periods of recirculation. Although these luminal projections would not be expected to inhibit reperfusion completely, they might increase microvascular resistance, leading to moderate hemodynamic impediments extending into the post-ischemic period. Similar periods of complete ischemia resulted in more severe microvascular alterations. Light and electron microscopic studies revealed a high frequency of compressed capillary lumina with vascular stasis. These compressed vessels were consistently surrounded by swollen astrocytic foot processes. When recirculation was instituted for 1 hr following 1 hr of complete ischemia, regions of non-perfusion were detected autoradiographically within brain regions destined to undergo ischemic infarction. Finally, in an attempt to determine the consequences of a primary microvascular insult on brain structure and function, the endothelial layer of microvessels in the cerebral cortex was injured using a noninvasive photochemical method. Endothelial damage led to platelet aggregation in both pial and intraparenchymal vessels. Occlusive thrombi were frequently detected with perivascular edema associated with vascular compression and severe focal ischemia. Ultrastructural blood-brain barrier studies using the horseradish peroxidase tracer demonstrated that protein leakage at the site of primary vascular injury resulted in tracer material in brain regions remote from the pathological lesion. The widespread leakage of protein tracer was associated with decreased blood flow in remote brain regions at several postirradiation periods. These data emphasize the importance of injury-induced microvascular dysfunction in the generation of brain lesions and hemodynamic abnormalities.

Lamina propria of intestinal mucosa as a typical reticular tissue

The three-dimensional architecture of the lamina propria in the jejunal mucosa of the rat was studied by scanning electron microscopy. The lamina propria is a typical reticular tissue with fine nets of reticular fibers and free and fixed cells lying among them. However, the lamina propria in the core of villi displayed structural features closer to other reticular or lymphoid tissues than that among the crypts. In the villi, the tissue was supported by a spongy framework of interconnecting fibroblasts, and densely infiltrated by free cells. Among the crypts, cellular elements were rather sparsely dispersed in a complex network of reticular fibers. A thin layer of reticular fibers lined the basal lamina of the epithelium. This layer contained a network of flattened cells which anastomosed with each other via slender processes. The basal lamina and the fibrous layer were perforated with round pores, through which free cells or basal processes of the epithelial cells passed. Many macrophages were found resting on the reticular framework of the lamina propria, frequently in close association with immunoblast-like cells. This paper further includes scanning electron-microscopic observations on the central lacteal with special reference to its luminal projections and trabeculae.

An ultrastructural and cytochemical study of enteroendocrine cells of the pyloric antrum in the gerbil, Meriones unguiculatus.

Enteroendocrine cells of the gastric antrum have been examined in the gerbil, Meriones unguiculatus. Gastrin-secreting G cells were identified by immunocytochemical methods and by transmission electron microscopy. They were present in the lower and middle third of the pyloric antral glands. G cells were polyhedral in shape and often extended to the gland lumen where they presented a microvillous and pinocytotic surface. These cells were characterized by numerous electron-dense and immunoreactive secretory granules. Enterochromaffin cells were identified by a serotonin-specific formaldehyde-induced fluorescence method, and by electron microscopy which revealed pleomorphic secretory granules of varying electron densities. These cells also had luminal projections and had a shape and distribution essentially similar to those of the G cells. A third endocrine cell type was identified as Dl cell in the pyloric glands. This cell type was recognized by the presence of numerous secretory granules having an electron-dense core and a clear peripheral space, as also by the presence of microfilament bundles, especially in the perinuclear region. The functional correlates of these morphological observations are discussed with reference to their secretory product and the manner of its release, especially by the G cells.

IDENTIFICATION OF THE DUODENAL VILLI

The duodenal mucosal pattern was examined in 100 patients undergoing biphasic contrast examinations of the upper gastrointestinal tract. The duodeni of 25% of these patients exhibited a finely, reticulated appearance with numerous 0.5–0.8 mm luminal projections. These findings were correlated with experimental animal studies in which triple-contrast small bowel studies were performed. In this experimental study, an appearance was found which was similar to that noted in the earlier mentioned patient group. Pathologic examination of the experimental preparations confirmed the fact that this fine, lace-like appearance was produced by the villi and not related to inflammation or filling of glandular elements. The clinical implications and potential applications of this information will be discussed.