Angiosarcoma of the Scalp: A Case Report

Angiosarcomas also called hemangioendothelia, are rare and highly malignant vascular tumors of mesodermal origin, they represent 08-10% of cancers and can affect any part of the body.Angiosarcoma mainly affects the skin, the face is the preferred topography in adults, it remains exceptional in children, with a predilection for the mediastinum and pericardium,The angiogenesis of angiosarcomas is still poorly understood; However, chronic lymphedema and exposure to prolonged radiotherapy are blamed. Total surgical excision is the treatment of choice in localized forms, followed by chemotherapy. pre- and post-operative radiotherapy may be necessary.New studies have shown the effectiveness of beta blockers (propranolol) in the management of angiosarcomas.The prognosis depends on the age of the patient, the size of the tumor, the histological grade and the extent of tumor progression.

Claudins: Beyond Tight Junctions in Human IBD and Murine Models

Claudins are transmembrane proteins constituting one of three tight junction protein families. In patients with inflammatory bowel disease (IBD), disease activity–dependent changes in expression of certain claudins have been noted, thus making certain claudin family members potential therapy targets. A study was undertaken with the aim of exploring expression of claudins in human disease and two different animal models of IBD: dextrane sulfate sodium–induced colitis and adoptive transfer model of colitis. The expression of sealing claudin-1, claudin-3, claudin-4, and claudin-8, and pore-forming claudin-2 in humans and rodents has been evaluated by immunohistochemistry and quantitative polymerase chain reaction. Claudins were expressed by epithelial and cells of mesodermal origin and were found to be situated at the membrane, within the cytoplasm, or within the nuclei. Claudin expression by human mononuclear cells isolated from lamina propria has been confirmed by Western blot and flow cytometry. The claudin expression pattern in uninflamed and inflamed colon varied between species and murine strains. In IBD and both animal models, diverse alterations in claudin expression by epithelial and inflammatory cells were recorded. Tissue mRNA levels for each studied claudin reflected changes within cell lineage and, at the same time, mirrored the ratio between various cell types. Based on the results of the study, it can be concluded that 1) claudins are not expressed exclusively by epithelial cells, but by certain types of cells of mesodermal origin as well; 2) changes in the claudin mRNA level should be interpreted in the context of overall tissue alterations; and 3) both IBD animal models that were analyzed can be used for investigating claudins as a therapy target, respecting their similarities and differences highlighted in this study.

Insulin-producing β-cells regenerate ectopically from a mesodermal origin under the perturbation of hemato-endothelial specification

To investigate the role of the vasculature in pancreatic β-cell regeneration, we crossed a zebrafish β-cell ablation model into the avascular npas4l mutant (i.e. cloche). Surprisingly, β-cell regeneration increased markedly in npas4l mutants owing to the ectopic differentiation of β-cells in the mesenchyme, a phenotype not previously reported in any models. The ectopic β-cells expressed endocrine markers of pancreatic β-cells, and also responded to glucose with increased calcium influx. Through lineage tracing, we determined that the vast majority of these ectopic β-cells has a mesodermal origin. Notably, ectopic β-cells were found in npas4l mutants as well as following knockdown of the endothelial/myeloid determinant Etsrp. Together, these data indicate that under the perturbation of endothelial/myeloid specification, mesodermal cells possess a remarkable plasticity enabling them to form β-cells, which are normally endodermal in origin. Understanding the restriction of this differentiation plasticity will help exploit an alternative source for β-cell regeneration.

More to Explore; The Mesenchymal Stem Cells (MSCs) Major Tissue Sources, Known Surface Markers, and Its Immunomodulation properties

Mesenchymal stem cells (MSCs) are currently available for a range of applications and have become a good material for regenerative medicine, tissue engineering, and disease therapy. MSCs are self-renewing, multipotent progenitor cells with multilineage potential to differentiate into cell types of mesodermal origin, such as adipocytes, osteocytes, and chondrocytes, and exert potent immunosuppressive potentials. In the present review, we highlight the currently reported variations in the differentiation potential of MSCs from different tissue sources, the minimal criteria to define MSCs from various tissue environments, and provide a detailed description of MSCs surface markers. Furthermore, MSC's immunomodulatory features secrete cytokines and immune receptors which regulate the microenvironment in the host tissue also revisits in detail. We propose that there are likely more sources of MSCs waiting to be discovered. We need to Standardize MSCs characterization by selecting markers for isolation, cellular and molecular mechanisms involved in MSC-mediated immune modulation, and other functionalities of MSCs should be characterized prior to use in clinical applications.

A Report of Incontinentia Pigmenti in an 11-year-old Girl

Introduction: Incontinentia pigmenti (IP) is a rarely diagnosed x-linked dominant disease affecting tissues of ectodermal and mesodermal origin such as cutaneous tissues, teeth, eyes, hair, and the central nervous system. Dermatologic manifestations are often the first signs observed in patients diagnosed with IP and are present in nearly all the subjects, but they are less harmful and do not require treatment. Oral manifestations in patients diagnosed with IP might affect both the deciduous and permanent teeth, with tooth shape anomalies and hypodontia, delayed tooth eruption, cleft palate, and high arched palate. These oral abnormalities influence feeding, quality of life (QoL), and self-esteem of the patient but can be successfully corrected by oral rehabilitation. Case Presentation: Here, we report the case of a female patient, aged 11 years, presenting with dental manifestations such as hypodontia, conical teeth, delayed tooth eruption, narrow and atrophic dental ridge, and also some non-dental findings of IP. Her dental ‎management included oral hygiene instructions, extraction of all unrestorable primary molars, and composite filling of all primary canines. Conclusions: A removable space maintainer was constructed for the patient, which resulted in favorable esthetic outcomes, proper re-establishment of mastication, and improved self-esteem.

Advances in development and application of human organoids

Innumerable studies associated with cellular differentiation, tissue response and disease modeling have been conducted in two-dimensional (2D) culture systems or animal models. This has been invaluable in deciphering the normal and disease states in cell biology; the key shortcomings of it being suitability for translational or clinical correlations. The past decade has seen several major advances in organoid culture technologies and this has enhanced our understanding of mimicking organ reconstruction. The term organoid has generally been used to describe cellular aggregates derived from primary tissues or stem cells that can self-organize into organotypic structures. Organoids mimic the cellular microenvironment of tissues better than 2D cell culture systems and represent the tissue physiology. Human organoids of brain, thyroid, gastrointestinal, lung, cardiac, liver, pancreatic and kidney have been established from various diseases, healthy tissues and from pluripotent stem cells (PSCs). Advances in patient-derived organoid culture further provides a unique perspective from which treatment modalities can be personalized. In this review article, we have discussed the current strategies for establishing various types of organoids of ectodermal, endodermal and mesodermal origin. We have also discussed their applications in modeling human health and diseases (such as cancer, genetic, neurodegenerative and infectious diseases), applications in regenerative medicine and evolutionary studies.

Associations of pathological diagnosis and genetic abnormalities in meningiomas with the embryological origins of the meninges

Certain driver mutations and pathological diagnoses are associated with the anatomical site of meningioma, based on which the meninges have different embryological origins. We hypothesized that mutations and pathological diagnoses of meningiomas are associated with different embryological origins. We comprehensively evaluated associations among tumor location, pathological diagnosis (histological type), and genetic alterations including AKT1, KLF4, SMO, POLR2A, and NF2 mutations and 22q deletion in 269 meningioma cases. Based on the embryological origin of meninges, the tumor locations were as follows: neural crest, paraxial mesodermal, and dorsal mesodermal origins. Tumors originating from the dura of certain embryologic origin displayed a significantly different pathological diagnoses and genetic abnormality ratio. For instance, driver genetic mutations with AKT1, KLF4, SMO, and POLR2A, were significantly associated with the paraxial mesodermal origin (p = 1.7 × 10−10). However, meningiomas with NF2-associated mutations were significantly associated with neural crest origin (p = 3.9 × 10–12). On analysis of recurrence, no difference was observed in embryological origin. However, POLR2A mutation was a risk factor for the tumor recurrence (p = 1.7 × 10−2, Hazard Ratio 4.08, 95% Confidence Interval 1.28–13.0). Assessment of the embryological origin of the meninges may provide novel insights into the pathomechanism of meningiomas.

Mesenchymal stem cells: A potent cell source for COVID-19

: Coronaviruses are enveloped positive-stranded RNA viruses that cause mild to acute respiratory illness. Coronaviruses can fuse their envelopes with the host cell membranes and deliver their genetic material. Coronavirus disease 2019 (COVID-19) is the seventh coronavirus closest to the bat severe acute respiratory syndrome (SARS) that infects humans. COVID-19 attacks the respiratory system and stimulates the host inflammatory responses, promotes the recruitment of immune cells, and enhances angiotensin-converting enzyme 2 (ACE2) activities. Patients with confirmed COVID-19 may have experienced fever, dry cough, headache, dyspnea, acute kidney injury (AKI), acute respiratory distress syndrome (ARDS), and acute heart injury. Several strategies such as oxygen therapy, ventilation, antibiotic or antiviral therapy, and renal replacement therapy are commonly used to decrease COVID-19-associated mortality. Inflammation is a common and important factor in the pathogenesis of COVID-19. In recent years, stem cell-based therapies represent a promising therapeutic option against various diseases. Mesenchymal stem cells (MSCs) are multipotent stem cells that can self-renew and differentiate into various tissues of mesodermal origin. MSCs can be derived from bone marrow, adipose tissue, and umbilical cord blood. MSCs with their unique immunomodulatory properties represent a promising therapeutic alternative against diseases associated with inflammation. Several previous studies have shown that MSCs with a strong safety profile can improve the treatment of patients with COVID-19. The information in this review provides a summary of the prevention and diagnosis of COVID-19. Also, we focus on the current clinical application of MSCs for treatments of patients with COVID-19.

Regenerating insulin-producing β-cells ectopically from a mesodermal origin in the absence of endothelial specification

To investigate the role of the vasculature in pancreatic β-cell regeneration, we crossed a zebrafish β-cell ablation model into the avascular npas4l mutant (i.e. cloche). Surprisingly, β-cell regeneration increased markedly in npas4l mutants owing to the ectopic differentiation of β-cells in the mesenchyme, a phenotype not previously reported in any models. The ectopic β-cells expressed endocrine markers of pancreatic β-cells, and also reduced glucose levels in the β-cell ablation model. Through lineage tracing, we determined that the vast majority of these ectopic β-cells derived from the mesodermal lineage. Notably, ectopic β-cells were found in npas4l mutants as well as following knockdown of the endothelial determinant Etv2. Together, these data indicate that in the absence of endothelial specification, mesodermal cells possess a remarkable plasticity enabling them to form β-cells, which are normally endodermal in origin. Understanding the restriction of this differentiation plasticity will help exploit an alternative source for β-cell regeneration.

Tissue expression of antigens of ABH blood groups in species of New World Monkeys (Aotus infulatus, Callithrix jacchus, Sapajus apella and Saimiri sciureus)

ABH antigens are histo-antigens, but were first described on the surface of human erythrocytes. They are found in those cells only in great apes and humans, while in more primitive animals they are found in tissues and body fluids. ABH antigens are mainly distributed in tissues that are in contact with the external environment and may serve as ligands for pathogens in tissues or block their connection. Description of the distribution of these molecules in non-human primate tissues is restricted to a few tissues and species. This paper describes the expression of human A, B and H type antigens in different organs from four species of New World Primates, obtained from the Centro Nacional de Primatas, as well as comparing that expression with what has been described for humans. In this study, although the tissue description of the antigens is similar to the genetic model for humans, some differences in expression between some organs from those species and those of humans were found. The differences occurred mainly in endodermal organs that have secretory functions and are probably under the control of the human-type FUT-2 enzyme. In the mesodermal-origin organs there was a reduction or absence of A and B antigen marking, particularly in the H precursor substance, indicating that those organs are under the control of the human-type FUT-1 enzyme. These findings have demonstrated that there is similar ABH antigen reactivity in tissue distribution between the species, although there are some species-specific cases.