The role of mesothelial cells in the host defence against bacteria : in vitro studies of peritonitis

The peritoneum is a serous membrane that lines both the intra-abdominal wall and the viscera contained wilhin the peritoneal cavity. Etymologically, 'peritoneum' means 'wrapped tightly around." The first description of the structure and function of the human peritoneum was given by James Doughlas in 1730. He observed that it was everywhere smooth and even and lubricated by a fiuid in order to preserve it from those inconveniences which otherwise would have followed from its continual attrilion wilh olher viscera. Human periloneum covers roughly the same surface area as the skin, approximately 2 m' in the adult. The parietal peritoneum covering the abdominal wall conslitutes about 10%, while the peritoneum covering the visceral organs, constitutes about 90% of this surface area. In males the peritoneum is completely closed, but in females it is open at the site of the uterine tubes, where the tubal peritoneum meets the non-peritonized fimbriated mucosa of the Fallopian tube. The peritoneum is a derivative of the embryological mesoderm and belongs to a distinct family of body tissues that share the same cellular composition and exhibit an identical histological architecture known as the serosa. The basic structure of the peritoneum appears to be rather simple; it is composed of a monolayer of mesothelial cells separated from the capillaries by a thin layer of loose conneclive interstilial tissue

An Atypical Case of Pelvic Leiomyomatosis Peritonealis Disseminata

An exceptional case of Leiomyomatosis peritonealis disseminata which occurred in a perimenopausal woman was mistaken for ovarian malignancy at laparotomy as it had extensive involvement of the pelvic peritoneum without a trace of leiomyoma in uterus and cervix

Providing adhesion for a miniture mobile intra-abdominal device based on biomimetic principles

This paper investigates the surface adhesion characteristics required for a miniature mobile device to move around the abdominal cavity. Such a device must be capable of adhering to the tissue lining and move freely across the upper surface of the insufflated abdomen. Accordingly, the potential of utilising bioinspired solutions to facilitate wet adhesion is assessed

Well-differentiated papillary mesothelioma of the peritoneum is genetically defined by mutually exclusive mutations in TRAF7 and CDC42.

Well-differentiated papillary mesothelioma is an uncommon mesothelial neoplasm that most frequently arises in the peritoneal cavity of women of reproductive age. Whereas malignant mesothelioma is an aggressive tumor associated with poor outcome, well-differentiated papillary mesothelioma typically exhibits indolent behavior. However, histologically differentiating between these two entities can be challenging, necessitating the development of distinguishing biomarkers. While the genetic alterations that drive malignant mesothelioma have recently been determined, the molecular pathogenesis of well-differentiated papillary mesothelioma is unknown. Here we performed genomic profiling on a cohort of ten well-differentiated papillary mesothelioma of the peritoneum. We identified that all tumors harbored somatic missense mutations in either the TRAF7 or CDC42 genes, and lacked alterations involving BAP1, NF2, CDKN2A, DDX3X, SETD2, and ALK that are frequent in malignant mesothelioma. We recently identified that another mesothelial neoplasm, adenomatoid tumor of the genital tract, is genetically defined by somatic missense mutations in the TRAF7 gene, indicating a shared molecular pathogenesis between well-differentiated papillary mesothelioma and adenomatoid tumors. To the best of our knowledge, well-differentiated papillary mesothelioma is the first human tumor type found to harbor recurrent mutations in the CDC42 gene, which encodes a Rho family GTPase. Immunohistochemistry demonstrated intact BAP1 expression in all cases of well-differentiated papillary mesothelioma, indicating that this is a reliable marker for distinguishing well-differentiated papillary mesothelioma from malignant mesotheliomas that frequently display loss of expression. Additionally, all well-differentiated papillary mesothelioma demonstrated robust expression of L1 cell adhesion molecule (L1CAM), a marker of NF-kB pathway activation, similar to that observed in adenomatoid tumors. In contrast, we have previously shown that L1CAM staining is not observed in normal mesothelial cells and malignant mesotheliomas of the peritoneum. Together, these studies demonstrate that well-differentiated papillary mesothelioma is genetically defined by mutually exclusive mutations in TRAF7 and CDC42 that molecularly distinguish this entity from malignant mesothelioma

The Potential of the Digital Anatomist Foundational Model for Assuring Consistency in UMLS Sources

Inconsistent anatomical concept representation can be identified in anatomy textbooks and hard copy term lists, as well as in UMLS source vocabularies and other controlled medical terminologies. In this report we select some examples of inconsistent representations of anatomical concepts, and illustrate how these inconsistencies can be explained and reconciled by the Digital Anatomist Foundational Model1. We use this process for gaining a measure of the validity of the logic-based Model

P.L.E.A.T.-Preventing Lymphocele Ensuring Absorption Transperitoneally: A Robotic Technique

OBJECTIVE: To reduce the risk of symptomatic lymphocele after robotic pelvic lymph node dissection (PLND), we present a novel technique, preventing lymphocele ensuring absorption transperitoneally (P.L.E.A.T.), where the peritoneum is "pleated" along its midline, leaving 2 lateral openings and allowing lymphatic fluid to drain away from the pelvis and into the abdomen. MATERIALS AND METHODS: We analyzed a single-surgeon series of PLNDs during robotic radical prostatectomy, comparing 195 "standard" PLNDs (in which the peritoneum was "re-approximated" or left completely open) with 176 cases in which P.L.E.A.T. was performed. RESULTS: In the group without P.L.E.A.T., 8 cases of symptomatic (grade 653, according to the Clavien-Dindo Classification) lymphoceles (4.1%) were recorded. Only 1 patient in the P.L.E.A.T. group complained of symptoms because of a lymphocele (P\u2009=\u2009.039). No patient reported complications because of the procedure. CONCLUSION: The P.L.E.A.T. technique is a fast, easy-to-perform, and safe method of reducing the risk of symptomatic lymphocele after transperitoneal robotic PLND

CXCR2 deficient mice display macrophage-dependent exaggerated acute inflammatory responses

CXCR2 is an essential regulator of neutrophil recruitment to inflamed and damaged sites and plays prominent roles in inflammatory pathologies and cancer. It has therefore been highlighted as an important therapeutic target. However the success of the therapeutic targeting of CXCR2 is threatened by our relative lack of knowledge of its precise in vivo mode of action. Here we demonstrate that CXCR2-deficient mice display a counterintuitive transient exaggerated inflammatory response to cutaneous and peritoneal inflammatory stimuli. In both situations, this is associated with reduced expression of cytokines associated with the resolution of the inflammatory response and an increase in macrophage accumulation at inflamed sites. Analysis using neutrophil depletion strategies indicates that this is a consequence of impaired recruitment of a non-neutrophilic CXCR2 positive leukocyte population. We suggest that these cells may be myeloid derived suppressor cells. Our data therefore reveal novel and previously unanticipated roles for CXCR2 in the orchestration of the inflammatory response

Caveolin-1 deficiency induces a MEK-ERK1/2-Snail-1-dependent epithelial-mesenchymal transition and fibrosis during peritoneal dialysis

Peritoneal dialysis (PD) is a form of renal replacement therapy whose repeated use can alter dialytic function through induction of epithelial-mesenchymal transition (EMT) and fibrosis, eventually leading to PD discontinuation. The peritoneum from Cav1-/- mice showed increased EMT, thickness and fibrosis. Exposure of Cav1-/- mice to PD fluids further increased peritoneal membrane thickness, altered permeability and increased the number of FSP-1/cytokeratin-positive cells invading the sub-mesothelial stroma. High-throughput quantitative proteomics revealed increased abundance of collagens, FN and laminin, as well as proteins related to TGF- activity in matrices derived from Cav1-/- cells. Lack of Cav1 was associated with hyperactivation of a MEK-ERK1/2-Snail-1 pathway that regulated the Smad2-3/Smad1-5-8 balance. Pharmacological blockade of MEK rescued E-cadherin and ZO-1 inter-cellular junction localization, reduced fibrosis and restored peritoneal function in Cav1-/- mice. Moreover, treatment of human PD-patient-derived MCs with drugs increasing Cav1 levels, as well as ectopic Cav1 expression, induced reacquisition of epithelial features. This study demonstrates a pivotal role of Cav1 in the balance of epithelial versus mesenchymal state and suggests targets for the prevention of fibrosis during PD