Serosal Membrane Research Articles

Study of Mannheim peritonitis index for predicting morbidity and mortality in patients of hollow viscous perforation: In a tertiary care hospital of Eastern India

Background: Peritonitis is the inflammation of peritoneum, the serosal membrane that lines the abdominal cavity and organs inside. The hollow viscous perforation (HVP) is one of the most common surgical emergencies encountered by surgeons on a daily basis. Mannheim Peritonitis Index (MPI) is a simple and effective method in predicting the morbidity of patients with HVP. Aims and Objectives: This study attempts to evaluate the prognostic value of MPI scoring system in patients with peritonitis due to HVP. Materials and Methods: This is a clinical, prospective, and observational study. There were 50 patients with HVP (stomach, duodenum, ileum, and appendix) admitted in Srirama Chandra Bhanja Medical College and Hospital from March 2021 to October 2022 included in the study. Necessary data were collected; MPI score was calculated for each patient and analyzed. Results: The number of post-operative complications, duration of intensive care unit, and hospital stay proportionately increased with the MPI score. Out of the eight variables used in this scoring system, duration of pain, intraperitoneal fluid and organ failure on admission carried more significance in predicting the morbidity in the post-operative period than the other variables. Conclusion: MPI is a simple and effective method in predicting the morbidity of patients with HVP and to assess it as a clinical tool in stratifying these patients according to individual surgical risk.

Intraperitoneal anatomy with the aid of pathologic fluid and gas: An imaging pictorial review.

The peritoneum is a large serosal membrane enveloping the abdomen and pelvic organs and forming the peritoneal cavity. This complex relationship forms many named abdominopelvic spaces, which are frequently involved in infectious, inflammatory, neoplastic, and traumatic pathologies. The knowledge of this anatomy is essential to the radiologist to localize and describe the extent of the disease accurately. This manuscript provides a comprehensive pictorial review of the peritoneal anatomy to describe pathologic fluid and gas.

Imaging Recommendations for Diagnosis, Staging, and Management of Peritoneal Malignancies

AbstractPeritoneum is a serosal membrane lining the solid viscera and the hollow viscus of the abdomen and is made of a single layer of mesothelial cells. The most common primaries that spread to the peritoneum include gastrointestinal, ovarian, colorectal, and peritoneal metastases can be seen at some point during the disease course in 15 to 43%, 60 to 70% and 15 to 20% of patients, respectively. Other malignancies involving the peritoneum such as primary peritoneal carcinoma, peritoneal mesothelioma, peritoneal lymphomatosis, pseudomyxoma peritonei from low-grade appendiceal mucinous neoplasm, are far less common. The review strives to provide a framework for diagnosis and management of the disease.

COMPLEX TREATMENT OF LOCALLY ADVANCED RECTAL CANCER (LITERATURE REVIEW)

Lack of public awareness, lack of eff ective screening programs in oncoproctology are the main reasons for late detection and late referral of patients with rectal cancer for help. The question of the approach to the complex treatment of rectal cancer is very relevant because the choice of the right direction signifi cantly aff ects the long-term results of treatment and the quality of life of patients. Conclusions. Preoperative radiation therapy is eff ective in downstaging, increasing resection rates and local control rates, especially for patients with inferior ampullary rectal cancer. Postoperative radiation therapy helps improve local control. Infi ltration beyond the serosal membrane, lymph node metastases, and a positive circular margin are important predictors of local recurrence, distant metastases, and overall survival.

Peritoneal disease: key imaging findings that help in the differential diagnosis.

The peritoneum is a unique serosal membrane, which can be the site of primary tumors and, more commonly, secondary pathologic processes. Peritoneal carcinomatosis is the most common malignant condition to affect the peritoneal cavity, and the radiologist plays an important role in making the diagnosis and assessing the extent of disease, especially in sites that may hinder surgery. In this review, we address the role of the radiologist in the setting of peritoneal pathology, focusing on peritoneal carcinomatosis as this is the predominant malignant process, followed by revising typical imaging findings that can guide the differential diagnosis.We review the most frequent primary and secondary peritoneal tumor and tumor-like lesions, proposing a systemic approach based on clinical history and morphological appearance, namely distinguishing predominantly cystic from solid lesions, both solitary and multiple.

Novel Humanized Mesothelin-Expressing Genetically Engineered Mouse Models Underscore Challenges in Delivery of Complex Therapeutics to Pancreatic Cancers.

Antibody-based therapies designed for human use frequently fail to cross-react with the murine isoform of their target. Because of this problem, preclinical studies of antibody-based mesothelin (Msl)-targeted therapeutics in immunocompetent systems have been limited by the lack of suitable mouse models. Here, we describe two immunocompetent humanized mesothelin transgenic mouse lines that can act as tolerant hosts for C57Bl/6-syngeneic cell lines expressing the human isoform of mesothelin. Thyroid peroxidase (TPO) mice have thyroid-restricted human mesothelin expression. Mesothelin (Msl) mice express human mesothelin in the typical serosal membrane distribution and can additionally be utilized to assess on-target, off-tumor toxicity of human mesothelin-targeted therapeutics. Both transgenic strains shed human mesothelin into the serum like human mesothelioma and patients with ovarian cancer, and serum human mesothelin can be used as a blood-based surrogate of tumor burden. Using these models, we examined the on-target toxicity and antitumor activity of human mesothelin-targeted recombinant immunotoxins. We found that immunotoxin treatment causes acute and chronic histologic changes to serosal membranes in Msl mice, while human mesothelin-expressing thyroid follicular cells in TPO mice are resistant to immunotoxin despite excellent drug delivery. Furthermore, poor delivery of immunotoxin to syngeneic orthotopic human mesothelin-expressing pancreatic adenocarcinoma limits antitumor activity both alone and in combination with immune checkpoint inhibition. In summary, we have developed two high-fidelity, immunocompetent murine models for human cancer that allow for rigorous preclinical evaluation of human mesothelin-targeted therapeutics.

Retrospective Evaluation of Malignant Peritoneal Mesothelioma Patients

ilişkilendirilmiştir. Malign peritoneal mezotelyoma (MPM) plevral tutulumdan sonra ikinci sıklıkta görülür. Çalışmamızda MPM tanısı alan hastalarda demografik özelliklerin, kullanılan tedavi seçeneklerinin incelenmesi amaçlandı. Çalışmamızda 12 erkek, 4 kadın toplamda 16 hastanın medyan yaşı 66 (46-93) yıldı. 15 hasta epiteolid, 1 hasta bifazik histopatolojiye sahipti. 2 hastaya hipertermik intraperitoneal kemoterapi (HİPEK) yapılmıştı. Birinci seçim kemoterapi alan 16 hasta, ikinci seçim kemoterapi alan 13 hasta, üçüncü seçim kemoterapi alan 4 hasta, dördüncü seçim kemoterapi alan 1 hasta mevcuttu. Birinci seçim kemoterapi alan hastaların medyan progresyonsuz sağkalımı 14,4 ay (CI %95 7,4:21,4) saptandı. Hastaların medyan toplam sağkalımı 22,0 aydı (CI %95 16:27,9). Standart tedavi seçenekleri arasında olan sitoredüksiyon cerrahisi + HİPEK, sistemik kemoterapi ve immünoterapinin optimal kullanımı ve bu tedavilere uygun hasta seçimi için prospektif, multidispliner, daha fazla hasta sayısı içeren çalışmalara ihtiyaç vardır.

MALIGNANT PERITONEAL MESOTHELIOMA -AN UNFORGOTTEN ABDOMINAL MALIGNANCY

Malignant peritoneal mesothelioma is a rare lethal malignancy of the serosal membranes of the peritoneum. The pathogenesis and association is strongly related with industrial pollutants asbestos, but less than pleural mesothelioma. Symptoms are nonspecific and related to the tumor spread within the abdominal cavity. CT scan is the investigation of choice and mostly disease is discovered incidentally on routine imaging. Diagnosis is confirmed on histopathology as well as immunohistochemical analysis of markers. The mainstay of treatment is cytoreductive surgery with Hyperthermic intraperitoneal chemotherapy. Here we present a very unusual case of malignant peritoneal mesothelioma diagnosed on routine evaluation of a 62 year old male admitted in emergency for obstructed inguinal hernia. Introduction: Malignant peritoneal Mesothelioma MPM is a very rare malignancy of the abdominal cavity. Mesotheliomas usually originate from the serosal membrane of different body cavities. Pleura is most commonly affected by mesothelioma followed by peritoneum and also other cavities pericardium and tunica vaginalis testis.10 to 30% of all mesothelioma affects peritoneum. Malignant peritoneal mesothelioma is a highly lethal malignant tumor of peritoneum and its pathogenesis is strongly related with industrial pollutant asbestos exposure. Diagnosis is difficult in most of the cases because of its nonspecific presentation and detected on routine abdominal imaging or Surgery

MALIGNANT PERITONEAL MESOTHELIOMA -AN UNFORGOTTEN ABDOMINAL MALIGNANCY.

Malignant peritoneal mesothelioma is a rare lethal malignancy of the serosal membranes of the peritoneum. The pathogenesis and association is strongly related with industrial pollutants asbestos, but less than pleural mesothelioma. Symptoms are nonspecific and related to the tumor spread within the abdominal cavity. CT scan is the investigation of choice and mostly disease is discovered incidentally on routine imaging. Diagnosis is confirmed on histopathology as well as immunohistochemical analysis of markers. The mainstay of treatment is cytoreductive surgery with Hyperthermic intraperitoneal chemotherapy. Here we present a very unusual case of malignant peritoneal mesothelioma diagnosed on routine evaluation of a 62 year old male admitted in emergency for obstructed inguinal hernia. Introduction: Malignant peritoneal Mesothelioma MPM is a very rare malignancy of the abdominal cavity. Mesotheliomas usually originate from the serosal membrane of different body cavities. Pleura is most commonly affected by mesothelioma followed by peritoneum and also other cavities pericardium and tunica vaginalis testis.10 to 30% of all mesothelioma affects peritoneum. Malignant peritoneal mesothelioma is a highly lethal malignant tumor of peritoneum and its pathogenesis is strongly related with industrial pollutant asbestos exposure. Diagnosis is difficult in most of the cases because of its nonspecific presentation and detected on routine abdominal imaging or Surgery

Comparison of the efficacy of Jabalpur prognostic scoring system with Mannheims peritonitis index in evaluation of prognosis in patients with perforation peritonitis

Background: Peritonitis is defined as inflammation of the serosal membrane that lines the abdominal cavity and the organs contained therein. Peritonitis is often caused by the introduction of infection into the otherwise sterile peritoneal environment through the perforation of the bowel, such as the ruptured appendix or colonic diverticulum. The disease may also be caused by the introduction of a chemically irritating material, such as gastric acid from a perforated ulcer. Peritonitis secondary to perforation of the gastrointestinal tract, a common occurrence in this country, requires emergency surgical intervention and is associated with significant morbidity and mortality rates.Methods: This was a comparative prospective cohort study in which 150 patients presenting with symptoms peritonitis secondary to hollow viscus perforation in general surgery department, Sri Venktaeshwara Medical College, Tiruapti from March 2017 to November 2018 were taken for the study.Results: Jabalpur prognostic scoring system has a slightly higher area under the curve of 96% when compared with the Mannheims peritonitis index score with 95%. So this shows that the Jabalpur prognostic scoring system has slightly greater indices than, that of Mannheims peritonitis index scoring system in predicting the prognosis of perforative peritonitis.Conclusions: In patients with perforation peritonitis, Jabalpur prognostic scoring system is an easy and reliable predictor in evaluating prognosis. In developing countries like India, where in resources are limited, Jabalpur prognostic scoring system will greatly help in predicting prognosis in patients with perforarion peritonitis. Because of its cost effectiveness, availability and ease of use, it is recommended as a part in the holistic approach of treatment of perforation peritonitis.

Gout Causing ABCG2 Mutation Results in Intestinal Net Urate Transport Defect, Hyperuricemia, & Altered Metabolic Phenotype

Hyperuricemia causes gout and is implicated in metabolic syndrome, impaired glucose tolerance/type 2 diabetes, and hypertension. Individuals carrying a common loss of function variant in the dominant secretory transporter, Q141K ABCG2, have significantly increased serum urate and gout risk yet their renal fractional excretion of urate (FEUA) is largely unchanged. However, the role in ABCG2 and other urate transporters in extra‐renal secretion remains mostly unexplored. Here we sought to identify the role of ABCG2 in trans‐epithelial urate transport in the intestines and contribution of intestinal ABCG2 dysfunction to hyperuricemia and urate related phenotypes. First, we established a genetic mouse model of the human ABCG2 Q141K variant (Q140K in mouse) using CRISPR Cas9 gene editing techniques on a C57BL6 mouse background. As compared to control mice, mice possessing the Q140K Abcg2 allele were profoundly hyperuricemic, yet exhibited only modest changes in renal excretion of urate, similar to what has been reported previously in humans. To explore mechanisms, we first mapped prominent urate transporters ABCG2 and SLC2A9 along the mouse intestine and found the highest levels in the jejunum and ileum. Localization of the wild type ABCG2 protein was exclusive to the brush border (apical membrane) of the villus cells, seemingly optimized to facilitate urate secretion(JUAsm). Interestingly, we also found evidence that SLC2A9 localized predominantly to the basolateral enterocyte membrane. In Ussing chamber experiments, we functionally confirmed basolateral localization of the electrogenic SLC2A9 transporter by observing basolateral but not apical addition of 0.5 mM urate significantly stimulated Isc (24 ± 3μA/cm2) in comparison with control (10± 2.2 μA/cm2). Further, treatment of the serosal membrane with SLC2A9 inhibitors tranilast and pCMBS partially inhibited JUAsm flux of urate in an intestinal loop model. In contrast to the WT controls, Q140K mice demonstrated a significant decrease of apical ABCG2 protein abundance, with commiserate, significant loss of unidirectional urate transport (JUAsm) in jejunal loops (Q140K, 24 ± 3.38 μM/cm2/min; WT, 46 ± 1.50 μM/cm2/min), resulting in conversion of net urate secretion (−18 ± 4 μM/cm2/min) to net urate absorption (+5.99 ± 2.2 μM/cm2/min). Interestingly, these significant alterations in intestinal urate secretion in the Q140K mice correlated with evidence of altered serum insulin and non‐fasting glucose levels, not unlike what has been previously reported in mice lacking intestinal SLC2A9 strongly suggesting the establishment of SLC2A9 and ABCG2 as the intestinal urate excretion pathway.CONCLUSIONSOur findings demonstrate the pathophysiology of one of the most common hyperuricemia and gout risk variants, Q141K ABCG2, primarily affects the urate secretion in the gut, causing hyperuricemia and alterations in insulin and glucose levels with important implications for human disease.Support or Funding InformationNIDDK RO1DK114091AHA14SDG18060004This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Stripped Mesenteric Flap: A Novel Option for Preventing Anastomotic Leakage in Circumferential Pharyngeal Reconstruction

Summary:Reconstruction of a circumferential pharyngeal defect with a free jejunal flap is a well-established procedure. However, anastomotic leakage often occurs, which can lead to abscess formation, pharyngocutaneous fistula formation, and carotid rupture. Previous reports have described covering the anastomotic site with a mesenteric flap to prevent anastomotic leakage. However, the mesentery is covered by a serosal membrane, which interferes with adhesion and vascular communication. Therefore, we stripped off the serosal membrane to accelerate adhesion to the anastomotic site. We retrospectively studied patients who had a history of radiotherapy and who had received a stripped mesenteric flap in a circumferential pharyngeal reconstruction procedure. We collected the following data: operative time, blood loss, postoperative complications, interval to resumption of oral intake, and duration of hospital stay. We obtained data for 11 patients. The jejunal flap failed in one patient because of arterial thrombosis. One of the other 10 patients developed anastomotic leakage caused by congested mucous membrane necrosis. The patient was treated conservatively and showed no clinical symptoms of infection or inflammation. The 9 remaining patients had no anastomotic leakage. In the present series, although anastomotic leakage was observed in one of 10 patients who underwent circumferential pharyngeal reconstruction using a stripped mesenteric flap, the severity of the leakage was minimized.

Novel staining procedures for whole mount preparations of greater wax moth (Galleria mellonella) embryos: toluidine blue-rhodamine B, plus calcofluor white

ABSTRACTAlthough hematoxylin and eosin (H & E) staining of sectioned embryonic insect material is widely used, it is time-consuming and may not provide sufficient information. We evaluated new staining procedures for embryonic whole mounts of the greater wax moth, Galleria mellonella. We compared a combination of toluidine blue and rhodamine B (TB-RB) to H & E; we also investigated calcofluor white (CFW) staining. TB-RB staining produced staining similar to H & E. TB-RB staining was less time-consuming and improved visualization of the blastoderm and its differentiation into the germ disk and serosa membrane. CFW enhanced details of mitosis in nuclei post-fertilization and stained the primary serosal membrane. Staining of whole mounts with TB-RB and CFW enabled embryonic staging that was more rapid, convenient and effective than the routine approach using H & E and fluorescent probes.

Difference in morphology and interactome profiles between orthotopic and subcutaneous gastric cancer xenograft models.

In xenograft models, orthotopic (ORT) engraftment is thought to provide a different tumor microenvironment compared with subcutaneous (SC) engraftment. We attempted to characterize the biological difference between OE19 (adenocarcinoma of the gastroesophageal junction) SC and ORT models by pathological analysis and CASTIN (CAncer-STromal INteractome) analysis, which is a novel method developed to analyze the tumor-stroma interactome framework. In SC models, SCID mice were inoculated subcutaneously with OE19 cells, and tumor tissues were sampled at 3 weeks. In ORT models, SCID mice were inoculated under the serosal membrane of the stomach wall, and tumor tissues were sampled at 3 and 6 weeks after engraftment. Results from the two models were then compared. Histopathologically, the SC tumors were well circumscribed from the adjacent tissue, with scant stroma and the formation of large ductal structures. In contrast, the ORT tumors were less circumscribed, with small ductal structures invading into abundant stroma. Then we compared the transcriptome profiles of human tumor cells with the mouse stromal cells of each model by species-specific RNA sequencing. With CASTIN analysis, we successfully identified several interactions that are known to affect the tumor microenvironment as being selectively enhanced in the ORT model. In conclusion, pathological analysis and CASTIN analysis revealed that ORT models of OE19 cells have a more invasive character and enhanced interaction with stromal cells compared with SC models.

Acute peritonitis secondary to hollow viscous perforation: a clinical study

Background: Peritonitis due to hollow visceral perforation is commonly encountered in surgical practice it is defined as inflammation of the serosal membrane that lines the abdominal cavity and the organs contained therein. The objective of this study was to study the frequency of peritonitis secondary to hollow viscous perforation and complications of operative management.Methods: 50 cases were studied with peritonitis due to hollow viscous perforation as surgical emergencies underwent emergency laparotomy, details of age, sex, anatomical location, signs and symptoms, reliability of investigation like X-ray-abdomen, complications, mortality were noted.Results: The most common age group affected is 50 years and above. Duodenum (52%) is the most common site of perforation followed by ileal perforation (26%) appendicular (14%) and colonic perforation (4%). 84% of the patients were male patients and 16% of the patients were females. Duodenal ulcer (52%) is the most common cause of perforative peritonitis followed by small intestinal perforation. The appendicular perforation forms the next commonest cause of perforation (14%). Guarding and rigidity was present in 90% of patients. Diagnosis is made clinically and confirmed by presence of pneumoperitoneum (76%) on radiographs. Laparotomy with closure of the perforation with omental patch (64%) is the commonest operative management for perforated peptic ulcer fallowed by simple closure, resection and anastomosis, and loop ileostomy. The most common postoperative complication observed was lower respiratory tract infection. Overall mortality rate was 8%. The average duration of stay in hospital is 12.44 days.Conclusions: Laparotomy with closure of the perforation with omental patch closure is the commonest method of surgical management in perforative peritonitis due to hollow viscous perforation.

CA-125 in Disease Progression and Treatment of Lymphangioleiomyomatosis

Lymphangioleiomyomatosis (LAM) is a destructive lung disease of women caused by proliferation of neoplastic-like LAM cells, with mutations in the TSC1/2 tumor suppressor genes. Based on case reports, levels of cancer antigen 125 (CA-125), an ovarian cancer biomarker, can be elevated in patients with LAM. We hypothesized that elevated serum CA-125 levels seen in some patients with LAM were due to LAM, not other malignancies, and might respond to sirolimus treatment. Serum CA-125 levels were measured for 241 patients at each visit. Medical records were reviewed for co-morbidities, disease progression, and response to sirolimus treatment. CA-125 expression in LAM cells was determined by using immunohistochemical analysis. Almost 25%of patients with LAM had at least one elevated serum CA-125 measurement. Higher serum CA-125 levels correlated with lower FEV1, premenopausal status, and pleural effusion in a multivariate model (each P< .001). Serum CA-125 levels decreased following sirolimus treatment (P= .002). CA-125 and α-smooth muscle actin were co-expressed in LAM lung nodules. Higher serum CA-125 levels were associated with pleural effusions and reduced pulmonary function and were decreased with sirolimus therapy. LAM cells express CA-125. Some elevated serum CA-125 levels may reflect serosal membrane involvement.

CK2 is a key regulator of SLC4A2-mediated Cl\u2212/HCO3\u2212 exchange in human airway epithelia

Transepithelial bicarbonate secretion by human airway submucosal glands and surface epithelial cells is crucial to maintain the pH-sensitive innate defence mechanisms of the lung. cAMP agonists stimulate HCO3− secretion via coordinated increases in basolateral HCO3− influx and accumulation, as well as CFTR-dependent HCO3− efflux at the luminal membrane of airway epithelial cells. Here, we investigated the regulation of a basolateral located, DIDS-sensitive, Cl−/HCO3− exchanger, anion exchanger 2 (AE2; SLC4A2) which is postulated to act as an acid loader, and therefore potential regulator of HCO3− secretion, in human airway epithelial cells. Using intracellular pH measurements performed on Calu-3 cells, we demonstrate that the activity of the basolateral Cl−/HCO3− exchanger was significantly downregulated by cAMP agonists, via a PKA-independent mechanism and also required Ca2+ and calmodulin under resting conditions. AE2 contains potential phosphorylation sites by a calmodulin substrate, protein kinase CK2, and we demonstrated that AE2 activity was reduced in the presence of CK2 inhibition. Moreover, CK2 inhibition abolished the activity of AE2 in primary human nasal epithelia. Studies performed on mouse AE2 transfected into HEK-293T cells confirmed almost identical Ca2+/calmodulin and CK2 regulation to that observed in Calu-3 and primary human nasal cells. Furthermore, mouse AE2 activity was reduced by genetic knockout of CK2, an effect which was rescued by exogenous CK2 expression. Together, these findings are the first to demonstrate that CK2 is a key regulator of Cl−-dependent HCO3− export at the serosal membrane of human airway epithelial cells.

Therapeutic use of Fisetin and Fisetin Loaded on Mesoporous Carbon Nanoparticle (MCN) in Thioglycollate-induced Peritonitis

Background: The pathophysiology of aseptic peritonitis involves inflammation of the serosal membrane that lines the abdominal cavity and the organs contained therein. The etiology of peritonitis is complicated and is involved in various processes, of which, the most important one is the inflammatory reaction. During the pathological process of peritonitis, NF-κB plays an activating role in the inflammatory reaction, which might be a potential therapeutic target in the therapy of certain inflammatory diseases. We studied the anti-inflammatory and pro-regenerative actions of Fisetin, a flavonol found in many plants, in a mouse model of thioglycollate-induced peritonitis, as well as the actions of fisetin administered with a nanoparticle such as mesoporous carbon nanoparticle (MCN). BALB/c mice were used in this study. Results: We found cell recruitment in the blood increased with the administration of thioglycollate (TG) after 24 h, 48 h, 72 h and 96 h, showing that it has induced inflammation. Cell recruitment was successfully inhibited by fisetin, and with MCN+fisetin. In the peritoneal fluid, total cell recruitment was increased, which was successfully inhibited with fisetin and MCN+fisetin treatment. TG treatment significantly reduced cell proliferation in the blood, PF and BM, within 24 h, till 96 h. Interestingly, cell proliferation increased with fisetin treatment, and with MCN+fisetin. The clonogenic potential of the tissues decreased significantly within 24 h, with administration of TG. Both fisetin treatment and MCN+fisetin treatment restored the clonogenic potential of the tissues. There was a decrease in Th2 cytokines with TG treatment, in blood after 48 h, and both fisetin and MCN+fisetin increased the cytokine content. Conclusion: In conclusion, we found that fisetin had a promising therapeutic effect on the peritonitis.

Lymphatic Stomata in the Adult Human Pulmonary Ligament.

Lymphatic stomata are small lymphatic openings in the serosal membrane that communicate with the serosal cavity. Although these stomata have primarily been studied in experimental mammals, little is known concerning the presence and properties of lymphatic stomata in the adult human pleura. Thus, adult human pleurae were examined for the presence or absence of lymphatic stomata. A total of 26 pulmonary ligaments (13 left and 13 right) were obtained from 15 adult human autopsy cases and examined using electron and light microscopy. The microscopic studies revealed the presence of apertures fringed with D2-40-positive, CD31-positive, and cytokeratin-negative endothelial cells directly communicating with submesothelial lymphatics in all of the pulmonary ligaments. The apertures' sizes and densities varied from case to case according to the serial tissue section. The medians of these aperture sizes ranged from 2.25 to 8.75 μm in the left pulmonary ligaments and from 2.50 to 12.50 μm in the right pulmonary ligaments. The densities of the apertures ranged from 2 to 9 per mm(2) in the left pulmonary ligaments and from 2 to 18 per mm(2) in the right pulmonary ligaments. However, no significant differences were found regarding the aperture size (p=0.359) and density (p=0.438) between the left and the right pulmonary ligaments. Our study revealed that apertures exhibit structural adequacy as lymphatic stomata on the surface of the pulmonary ligament, thereby providing evidence that lymphatic stomata are present in the adult human pleura.

Transcriptome of a specialized extra-embryonic cell, teratocyte, and its host immunosuppressive role revealed by ex vivo RNA interference.

The specialized wasp cells teratocytes (TCs) are derived from the embryonic serosal membrane of some parasitic hymenopteran insects. As a parasitic factor, TCs are multifunctional in host regulation, such as host nutritional deprivation, immunosuppression and developmental arrest; however, little is understood about their genetic constituents. The present study provides a comprehensive view of the genes expressed by TCs through a transcriptome analysis based on RNA sequencing technology. The assembled 34 686 contigs (>200 base pairs) were annotated into different functional categories, indicating a distinct distribution in gene transcripts compared with those of haemocytes and fat body. The TC transcriptome contained components of insulin signalling and biosyntheses of juvenile hormone and 20-hydroxyecdysone. TCs also expressed various groups of digestive enzymes, indicating that they have nutritional role for the growing parasitoid larvae in parasitism. Furthermore, through this transcriptome analysis two kinds of immunosuppressive serine protease inhibitors (serpins) and Rho GTPase-activating proteins (RhoGAPs) were annotated. To determine the biological functions of these factors, we devised ex vivo RNA interference (RNAi) by conducting knockdown of gene expression in in vitro-cultured TCs followed by injection of the treated TCs to test insects. Ex vivo RNAi revealed that some serpins and RhoGAPs expressed in TCs inhibited host cellular immunity. This study reports a transcriptome of the unique TC animal cell and its immunosuppressive genetic factors using ex vivo RNAi technology.