Macrophages inhibit and enhance endometriosis depending on their origin.

Macrophages are intimately involved in the pathophysiology of endometriosis, a chronic inflammatory disorder characterized by the growth of endometrial-like tissue (lesions) outside the uterus. By combining genetic and pharmacological monocyte and macrophage depletion strategies we determined the ontogeny and function of macrophages in a mouse model of induced endometriosis. We demonstrate that lesion-resident macrophages are derived from eutopic endometrial tissue, infiltrating large peritoneal macrophages (LpM) and monocytes. Furthermore, we found endometriosis to trigger continuous recruitment of monocytes and expansion of CCR2+ LpM. Depletion of eutopic endometrial macrophages results in smaller endometriosis lesions, whereas constitutive inhibition of monocyte recruitment significantly reduces peritoneal macrophage populations and increases the number of lesions. Reprogramming the ontogeny of peritoneal macrophages such that embryo-derived LpM are replaced by monocyte-derived LpM decreases the number of lesions that develop. We propose a putative model whereby endometrial macrophages are "proendometriosis" while newly recruited monocyte-derived macrophages, possibly in LpM form, are "antiendometriosis." These observations highlight the importance of monocyte-derived macrophages in limiting disease progression.

Farnesol remodels the peritoneal cavity immune environment influencing Candida albicans pathogenesis during intra-abdominal infection.

Candida albicans is a lifelong member of the mycobiome causing mucosal candidiasis and life-threatening, systemic, and intra-abdominal disease in immunocompromised and transplant patients. Despite the clinical importance of intra-abdominal candidiasis with mortality rates between 40% and 70%, the contribution of fungal virulence factors and host immune responses to disease has not been extensively studied. Secretion of the quorum-sensing molecule, farnesol, acts as a virulence factor for C. albicans during systemic infection, while inducing local, protective innate immune responses in oral models of infection. Previously, we reported that farnesol recruits macrophages to the peritoneal cavity in mice, suggesting a role for farnesol in innate immune responses. Here, we expand on our initial findings, showing that farnesol profoundly alters the peritoneal cavity microenvironment promoting innate inflammation. Intra-peritoneal injection of farnesol stimulates rapid local death of resident peritoneal cells followed by recruitment of neutrophils and inflammatory macrophages into the peritoneal cavity and peritoneal mesothelium associated with an early increase in chemokines followed by proinflammatory cytokines. These rapid inflammatory responses to farnesol significantly increase morbidity and mortality of mice with intra-abdominal candidiasis associated with increased formation of peritoneal adhesions, despite similar rates of fungal clearance from the peritoneal cavity and retro-peritoneal organs. C. albicans ddp3Δ/ddp3Δ knockout and reconstituted strains recapitulate these findings. This indicates that farnesol may be detrimental to the host during intra-abdominal infections. Importantly, our results highlight a need to understand how C. albicans virulence factors modulate the host immune response within the peritoneum, an exceedingly common site of Candida infection.

Genomic catastrophe, the peritoneal cavity and ovarian cancer prevention.

The current theory of carcinogenesis for the deadliest of 'ovarian' cancers-high-grade serous carcinoma (HGSC)-holds that the malignancy develops first in the fallopian tube and spreads to the ovaries, peritoneum, and/or regional lymph nodes. This is based primarily on the observation of early forms of serous neoplasia (serous tubal intraepithelial lesions [STILs], and serous tubal intraepithelial carcinomas [STICS]) in the fimbria of women undergoing risk reduction surgery. However, these lesions are uncommon in the general population, confer a low risk (5%) of HGSC following their removal in at-risk women with germ-line BRCA1/2 mutations, and require 4 or more years to recur as intraperitoneal HGSC. These features suggest that isolated STILs and STICs behave as precursors, with uncertain cancer risk rather than carcinomas. Their evolution to HGSC within, or after, escape from the tube could proceed stepwise with multiple biologic events; however, it is unclear whether tubal or ovarian HGSCs encountered in the setting of advanced disease evolved in the same fashion. The latter scenario could also be explained by a 'catastrophic' model in which STICs suddenly develop with invasive and metastatic potential, overwhelming or obscuring the site of origin. Moreover, a similar model might explain the sudden emergence of HGSC in the peritoneal cavity following escape of precursor cells years before. Long-term follow-up data from opportunistic or prophylactic salpingectomy should shed light on where malignant transformation occurs, as well as the timeline from precursor to metastatic HGSC. © 2022 The Pathological Society of Great Britain and Ireland.

Revisiting the Use of Normal Saline for Peritoneal Washing in Ovarian Cancer.

The omentum is the predominant site of ovarian cancer metastasis, but it is difficult to remove the omentum in its entirety. There is a critical need for effective approaches that minimize the risk of colonization of preserved omental tissues by occult cancer cells. Normal saline (0.9% sodium chloride) is commonly used to wash the peritoneal cavity during ovarian cancer surgery. The omentum has a prodigious ability to absorb fluid in the peritoneal cavity, but the impact of normal saline on the omentum is poorly understood. In this review article, we discuss why normal saline is not a biocompatible solution, drawing insights from clinical investigations of normal saline in fluid resuscitation and from the cytopathologic evaluation of peritoneal washings. We integrate these insights with the unique biology of the omentum and omental metastasis, highlighting the importance of considering the absorptive ability of the omentum when administering agents into the peritoneal cavity. Furthermore, we describe insights from preclinical studies regarding the mechanisms by which normal saline might render the omentum conducive for colonization by cancer cells. Importantly, we discuss the possibility that the risk of colonization of preserved omental tissues might be minimized by using balanced crystalloid solutions for peritoneal washing.

Anatomy and histology of the foramen of ovarian bursa opening to the peritoneal cavity and its changes in autoimmune disease-prone mice.

The ovarian bursa is a small peritoneal cavity enclosed by the mesovarium and mesosalpinx, which surrounds the ovaries and oviductal infundibulum in mammals. The ovarian bursa is considered as the structure facilitating the transport of ovulated oocytes into the oviduct. Our previous study revealed reduced oocyte pick-up function in the oviduct of lupus-prone MRL/MpJ-Faslpr/lpr mouse, suggesting the possibility of an escape of ovulated oocytes into the peritoneal cavity, despite the presence of an almost complete ovarian bursa in the mouse. In this study, we revealed anatomical and histological characteristics of the ovarian bursa in C57BL/6 N, MRL/MpJ, and MRL/MpJ-Faslpr/lpr mice. All strains had the foramen of ovarian bursa (FOB), with a size of approximately 0.04 to 0.12 cm2 , surrounded by the ligament of ovarian bursa (LOB), which is part of the mesosalpinx. The LOB was partially lined with the cuboidal mesothelial cells and consisted of a thick smooth muscle layer in all strains. In 6-month-old MRL/MpJ-Faslpr/lpr mice, in which the systemic autoimmune abnormality deteriorated and oocyte pick-up function was impaired, the size of the FOB tended to be larger than that of other strains. Additionally, in MRL/MpJ-Faslpr/lpr mice at 6 months of age, there was infiltration by numerous immune cells in the mesosalpinx suspending the isthmus; however, the LOB prevented severe inflammation and showed deposition of collagen fibers. These results not only indicate that the FOB is a common structure within mice, but also imply the physiological function of the LOB and its role in maintaining the microenvironment around the ovary, as well as regulating healthy reproduction.

Re-thinking the prognostic significance of positive peritoneal cytology in endometrial cancer.

BACKGROUND: Whether abnormal peritoneal cytology (PC) is an independent prognostic factor in endometrial cancer (EC) remains controversial. This study aimed to re-think the prognostic significance of PC in not only all EC patients but also in various subgroups with similar clinicopathological and biological characteristics. METHODS: EC patients who underwent primary surgery of at least a hysterectomy and were pathologically diagnosed with EC in four hospitals affiliated with the Jikei University School of Medicine were retrospectively reviewed. The prognostic significance of PC was evaluated with univariate and multivariate analyses in the entire cohort and subgroups stratified by surgical stages (early/advanced stages), tumor types (types 1/2), and risk classifications (low/intermediate/high). RESULTS: Of 1963 EC cases, 1616 met the inclusion criteria. Positive PC was identified as an adverse prognostic factor in analyses of all EC cases and in all subgroup analyses stratified by surgical stages and tumor types. In survival curve comparisons, the progression-free survival (PFS) and disease-specific survival in early-stage patients with positive PC were clearly located between those of stage II patients with negative PC and stage III patients. In the subgroup analyses stratified by risk classification in early-stage EC, positive PC was related to poorer PFS in the intermediate- and high-risk groups but not in the low-risk group. CONCLUSION: PC status was an independent prognostic factor of EC in all stages and tumor types. Early PC-positive cases, except for the low-risk group, may be recommended for upstaging and should be carefully managed compared with PC-negative cases.

Development of a clinically relevant ovarian cancer model incorporating surgical cytoreduction to evaluate treatment of micro-metastatic disease.

OBJECTIVES: Mouse models of ovarian cancer commonly transfer large numbers of tumor cells into the peritoneal cavity to establish experimental metastatic disease, which may not adequately model early metastatic spread from a primary tumor site. We hypothesized we could develop an ovarian cancer model that predictably represents micro-metastatic disease. METHODS: Murine ID8VEGF ovarian cancer cells were transduced to express enhanced luciferase (eLuc) to enable intravital detection of microscopic disease burden and injected beneath the ovarian bursa of C57Bl/6 mice. At 6 or 10 weeks after orthotopic injection, when mice had detectable metastases, hysterectomy and bilateral salpingo-oophorectomy was performed to remove all macroscopic disease, and survival monitored. Immunohistochemistry and gene expression profiling were performed on primary and metastatic tumors. RESULTS: eLuc-transduced ID8VEGF cells were brighter than cells transduced with standard luciferase, enabling in vivo visualization of microscopic intra-abdominal metastases developing after orthotopic injection. Primary surgical cytoreduction removed the primary tumor mass but left minimal residual disease in all mice. Metastatic sites that developed following orthotopic injection were similar to metastatic human ovarian cancer sites. Gene expression and immune infiltration were similar between primary and metastatic mouse tumors. Surgical cytoreduction prolonged survival compared to no surgery, with earlier cytoreduction more beneficial than delayed, despite micro-metastatic disease in both settings. CONCLUSIONS: Mice with primary ovarian tumors established through orthotopic injection develop progressively fatal metastatic ovarian cancer, and benefit from surgical cytoreduction to remove bulky disease. This model enables the analysis of therapeutic regimens designed to target and potentially eradicate established minimal residual disease.

Prediction of intraperitoneal adhesions using striae gravidarum and scar characteristics in women undergoing repeated cesarean sections.

BACKGROUND: The current fact of increasing rates of cesarean deliveries is a catastrophe. Recurrent cesareans result in intraperitoneal adhesions that would lead to maternal morbidity during delivery. Great efforts are directed towards the prediction of intraperitoneal adhesions to provide the best care for laboring women. The aim of the current study was to evaluate the role of abdominal striae and cesarean scar characters in the prediction of intraperitoneal adhesions. METHODS: This was a case- control study conducted in the emergency ward of the obstetrics and gynecology department of a tertiary hospital from June to December 2019. The study was carried on patients admitted to the ward fulfilling particular inclusion and exclusion criteria. The study included two groups, group one was assessed for the presence of striae, and the degree of intraperitoneal adhesions was evaluated during the current cesarean section. Group two included patients without evidence of abdominal striae. They were evaluated for the severity of adhesions also after evaluation of the previous scar. Evaluation of the striae was done using Davey's scoring system. The scar was assessed using the Vancouver Scar Scale. The modified Nair's scoring system was used to evaluate intraperitoneal adhesions. RESULTS: The study group included 203 women, while the control group included 205 women. There were significant differences in the demographic characters of the recruited patients (p-value 0.001 for almost all variables). The mean Davey score in those with mild, moderate, and severe striae was 1.82 ± 0.39, 3.57 ± 0.5, and 6.73 ± 0.94, respectively (p-value < 0.001). Higher scores for the parameters of the Vancouver scale were present in patients with severe striae (1.69 ± 1.01, 1.73 ± 0.57, 2.67 ± 1.23, and 1.35 ± 1.06 for scar vascularity, pigmentation, pliability, and height respectively with a p-value of < 0.001 each). Thick intraperitoneal adhesions were noted significantly in women with severe striae [21 (43.75%), p-value < 0.001)]. The Davey's and Vancouver scores showed highly significant predictive performance in the prediction of intraperitoneal adhesions (p-value < 0.001). CONCLUSION: Abdominal striae and cesarean scar were significant predictors for intraperitoneal adhesions.

Vascular Endothelial Integrity Affects the Severity of Enterovirus-Mediated Cardiomyopathy.

Coxsackievirus and adenovirus receptor (CAR) is present in epithelial and vascular endothelial cell junctions. We have previously shown a hemorrhagic phenotype in germ-line CAR knock-out mouse embryos; we have also found that CAR interacts with ZO-1 and ß-catenin. However, the role of CAR in vascular endothelial junction permeability has not been proven. To understand the roles of CAR in the vascular endothelial junctions, we generated endothelium-specific CAR knockout (CAR-eKO) mice. In the absence of CAR, the endothelial cell layer showed an increase in transmembrane electrical resistance (TER, Ω) and coxsackievirus permeability. Evans blue dye and 70 kDa dextran-FITC were delivered by tail vein injection. We observed increased vascular permeability in the hearts of adult CAR-eKO mice compare with wild-type (WT) mice. There was a marked increase in monocyte and macrophage penetration into the peritoneal cavity caused by thioglycolate-induced peritonitis. We found that CAR ablation in endothelial cells was not significantly increased coxsackievirus B3 (CVB3) induced myocarditis in murine model. However, tissue virus titers were significantly higher in CAR-eKO mice compared with WT. Moreover, CVB3 was detected in the brain of CAR-eKO mice. Endothelial CAR deletion affects the expression of major endothelial junction proteins, such as cadherin and platelet endothelial cell adhesion molecule-1 (PECAM-1) in the cultured endothelial cells as well as liver vessel. We suggest that CAR expression is required for normal vascular permeability and endothelial tight junction homeostasis. Furthermore, CVB3 organ penetration and myocarditis severities were dependent on the endothelial CAR level.

Anti-Inflammatory, Antipyretic, and Analgesic Properties of Potamogeton perfoliatus Extract: In Vitro and In Vivo Study.

Natural antioxidants, especially those of plant origins, have shown a plethora of biological activities with substantial economic value, as they can be extracted from agro-wastes and/or under exploited plant species. The perennial hydrophyte, Potamogeton perfoliatus, has been used traditionally to treat several health disorders; however, little is known about its biological and its medicinal effects. Here, we used an integrated in vitro and in vivo framework to examine the potential effect of P. perfoliatus on oxidative stress, nociception, inflammatory models, and brewer's yeast-induced pyrexia in mice. Our results suggested a consistent in vitro inhibition of three enzymes, namely 5-lipoxygenase, cyclooxygenases 1 and 2 (COX-1 and COX-2), as well as a potent antioxidant effect. These results were confirmed in vivo where the studied extract attenuated carrageenan-induced paw edema, carrageenan-induced leukocyte migration into the peritoneal cavity by 25, 44 and 64% at 200, 400 and 600 mg/kg, p.o., respectively. Moreover, the extract decreased acetic acid-induced vascular permeability by 45% at 600 mg/kg, p.o., and chemical hyperalgesia in mice by 86% by 400 mg/kg, p.o., in acetic acid-induced writhing assay. The extract (400 mg/kg) showed a longer response latency at the 3 h time point (2.5 fold of the control) similar to the nalbuphine, the standard opioid analgesic. Additionally, pronounced antipyretic effects were observed at 600 mg/kg, comparable to paracetamol. Using LC-MS/MS, we identified 15 secondary metabolites that most likely contributed to the obtained biological activities. Altogether, our findings indicate that P. perfoliatus has anti-inflammatory, antioxidant, analgesic and antipyretic effects, thus supporting its traditional use and promoting its valorization as a potential candidate in treating oxidative stress-associated diseases.

The Lesser Sac and Foramen of Winslow: Anatomy, Embryology, and CT Appearance of Pathologic Processes.

OBJECTIVE. This article reviews the embryologic development, relevant anatomy, and imaging features, on CT, of pathologic processes involving the lesser sac and foramen of Winslow. CONCLUSION. The lesser peritoneal sac is an intricate anatomic region involved in many disease processes. It is a significant conduit for the spread of disease within the peritoneal cavity. The spectrum of pathologic processes pertaining to the lesser sac can be classified on the basis of the type of involvement, such as a fluid collection (e.g., transudate, exudate, bile, and blood), a mass (e.g., neoplastic or nonneoplastic conditions and lymphadenopathy), or an internal hernia into the lesser sac.

Impact of hysteroscopy on course of disease in high-risk endometrial carcinoma.

OBJECTIVE: Previous studies have investigated the impact of preoperative hysteroscopy on the staging and survival of predominantly grade 1 endometrial cancers. We sought to evaluate the effect of hysteroscopy on the peritoneal spread of tumor cells and disease course in a large series of patients with high-risk endometrial cancer. METHODS: Patients who underwent hysterectomy for grade 3 endometrial carcinoma on final surgical pathology at the Mayo Clinic in Rochester, MN between January 2009 to June 2016 were included, noting hysteroscopy within 6 months from surgery. Intra-peritoneal disease was defined as any positive cytology OR adnexal invasion OR stage IV. The presence of intra-peritoneal disease OR peritoneal recurrence within 2 years from surgery was defined as peritoneal dissemination. Cox proportional hazards models were fit to evaluate associations between hysteroscopy exposure and progression within 5 years following surgery. RESULTS: Among 831 patients, 133 underwent hysteroscopy. There was no difference in age, body mass index, ASA ≥3, or serous histology between patients who did or did not undergo hysteroscopy. Advanced stage disease (III/IV) was less common among patients who underwent hysteroscopy (30.1% vs 43.8%, P=0.003). No difference was observed between those with vs without hysteroscopy in the rate of positive cytology (22.0% vs 29.7%, P=0.09), stage IV (16.5% vs 21.9%, P=0.16), intra-peritoneal disease (28.6% vs 36.1%, P=0.09), or peritoneal dissemination (30.8% vs 39.3%, P=0.06). On stratifying by stage, hysteroscopy did not increase the risk of progression (HR 1.06, 95% CI 0.59 to 1.92 for stage I/II; HR 0.96, 95% CI 0.62 to 1.48 for stage III/IV). CONCLUSION: In this retrospective study of grade 3 endometrial cancer, we did not observe any significant association between pre-operative hysteroscopy and the incidence of positive cytology, peritoneal disease, peritoneal dissemination, or cancer progression.

Lactic acid suppresses IgE-mediated mast cell function in vitro and in vivo.

Mast cells have functional plasticity affected by their tissue microenvironment, which greatly impacts their inflammatory responses. Because lactic acid (LA) is abundant in inflamed tissues and tumors, we investigated how it affects mast cell function. Using IgE-mediated activation as a model system, we found that LA suppressed inflammatory cytokine production and degranulation in mouse peritoneal mast cells, data that were confirmed with human skin mast cells. In mouse peritoneal mast cells, LA-mediated cytokine suppression was dependent on pH- and monocarboxylic transporter-1 expression. Additionally, LA reduced IgE-induced Syk, Btk, and ERK phosphorylation, key signals eliciting inflammation. In vivo, LA injection reduced IgE-mediated hypothermia in mice undergoing passive systemic anaphylaxis. Our data suggest that LA may serve as a feedback inhibitor that limits mast cell-mediated inflammation.

Transgenic Mice Expressing Human Proteinase 3 Exhibit Sustained Neutrophil-Associated Peritonitis.

Proteinase 3 (PR3) is a myeloid serine protease expressed in neutrophils, monocytes, and macrophages. PR3 has a number of well-characterized proinflammatory functions, including cleaving and activating chemokines and controlling cell survival and proliferation. When presented on the surface of apoptotic neutrophils, PR3 can disrupt the normal anti-inflammatory reprogramming of macrophages following the phagocytosis of apoptotic cells. To better understand the function of PR3 in vivo, we generated a human PR3 transgenic mouse (hPR3Tg). During zymosan-induced peritonitis, hPR3Tg displayed an increased accumulation of neutrophils within the peritoneal cavity compared with wild-type control mice, with no difference in the recruitment of macrophages or B or T lymphocytes. Mice were also subjected to cecum ligation and puncture, a model used to induce peritoneal inflammation through infection. hPR3Tg displayed decreased survival rates in acute sepsis, associated with increased neutrophil extravasation. The decreased survival and increased neutrophil accumulation were associated with the cleavage of annexin A1, a powerful anti-inflammatory protein known to facilitate the resolution of inflammation. Additionally, neutrophils from hPR3Tg displayed enhanced survival during apoptosis compared with controls, and this may also contribute to the increased accumulation observed during the later stages of inflammation. Taken together, our data suggest that human PR3 plays a proinflammatory role during acute inflammatory responses by affecting neutrophil accumulation, survival, and the resolution of inflammation.

Cell Spillage after Contained Electromechanical Morcellation Using a Specially Designed In-Bag System for Laparoscopic Myomectomy: Prospective Cohort Pilot Study.

STUDY OBJECTIVE: Few reports have investigated the use of endoscopic retrieval bags in the context of laparoscopic myomectomy with electromechanical morcellation. We performed a leak test of a specially designed endoscopic bag system in women undergoing laparoscopic myomectomy with contained electromechanical morcellation. DESIGN CLASSIFICATION: Prospective study. SETTING: University hospital. PATIENTS: Thirty-one women undergoing laparoscopic myomectomy with contained electromechanical morcellation. INTERVENTIONS: Electromechanical morcellation was introduced for large specimen extraction during laparoscopic procedures. Complications such as retained/disseminated parasitic tissue were documented. MEASUREMENTS AND MAIN RESULTS: Systematic peritoneal washings were performed at 3 specific times: at baseline, T1, once the peritoneal cavity was accessed laparoscopically; T2, when the myometrial incision was closed after myomectomy; and T3, after contained electromechanical morcellation. After retrieval of the endoscopic bag from the abdominal cavity, visual inspection and water test on the bag with NaCl infiltration were performed to detect leaks attributed to intraoperative perforations. A pathologist performed cytologic analyses on the 3 washings. The mean endoscopic bag procedure duration was 9 minutes. The use of a specially designed endoscopic bag system was found to be easy in 45% of cases, and no complications were reported. Cytologic washings were positive for smooth muscle cell detection in 8 cases (25.8%) at T2 and 3 cases (9.7%) at T3. All positive cases at T3 already had detectable smooth muscle cells at T2. After retrieval from the abdominal cavity, perforations on the optic access of the endoscopic bag were observed in 3 cases. CONCLUSION: The results from this pilot study are encouraging. The use of a specially designed endoscopic bag system could be an adjuvant to reduce the risk of disseminating cells during myomectomy.

Effect of different cryopreservation regimens on Ehrlich carcinoma growth.

The freezing rate is a decisive factor in determining the purpose of using low temperatures, i.e., for cryoablation or cryobanking of tumor cells. The research aim was to determine effect of different cryopreservation regimens on Ehrlich carcinoma (EC) growth in vivo and subpopulation composition of the formed ascites. The previously cryopreserved with slow and rapid rates EC cells were cultured in peritoneal cavity (PC) of mice for 7 days. Absolute number of cells in the PC, the subpopulation composition of tumor with flow cytometry using CD44 and CD24 markers were determined. Immediately after warming, a significant redistribution of EC subpopulation composition with a decreased content of the most tumorigenic CD44high cells after both freezing regimens was found. Culturing in vivo for 7 days contributed to the restoration of EC subpopulation composition, but with some a decrease in the tumor growth intensity when slow cooling was used. Rapid cooling contributed to significant inhibition of tumor growth with a reduced number of CD44+ and increased CD24+ cells. None of the cryopreservation regimens resulted in a complete elimination of tumorigenic CD44high tumor cells. The freezing rate determines the preservation of the subpopulation composition of the EC and intensity of its growth in vivo.

Long-Lasting Anti-Inflammatory and Antinociceptive Effects of Acute Ammonium Glycyrrhizinate Administration: Pharmacological, Biochemical, and Docking Studies.

The object of the study was to estimate the long-lasting effects induced by ammonium glycyrrhizinate (AG) after a single administration in mice using animal models of pain and inflammation together with biochemical and docking studies. A single intraperitoneal injection of AG was able to produce anti-inflammatory effects in zymosan-induced paw edema and peritonitis. Moreover, in several animal models of pain, such as the writhing test, the formalin test, and hyperalgesia induced by zymosan, AG administered 24 h before the tests was able to induce a strong antinociceptive effect. Molecular docking studies revealed that AG possesses higher affinity for microsomal prostaglandin E synthase type-2 compared to type-1, whereas it seems to locate better in the binding pocket of cyclooxygenase (COX)-2 compared to COX-1. These results demonstrated that AG induced anti-inflammatory and antinociceptive effects until 24-48 h after a single administration thanks to its ability to bind the COX/mPGEs pathway. Taken together, all these findings highlight the potential use of AG for clinical treatment of pain and/or inflammatory-related diseases.

Intestinal helminth infection induces highly functional resident memory CD4+ T cells in mice.

Immunity to intestinal nematodes requires CD4⁺ Th2-cell responses, including IL-4 and IL-13 production. Chronic infection with intestinal nematodes leads to downregulation of these responses, and few functional T helper (Th) 2 cells are detected in secondary lymphoid organs in the chronic phase or after abrogation of infection. Here, we show with a natural murine infection with Heligmosomoides polygyrus that highly functional memory Th2 cells persist in the lamina propria and in addition in the peritoneal cavity (PC) after abrogation of infection. While both tissue-resident memory (TRM ) populations proliferate in situ and express IL-4, IL-5, and IL-13 upon TCR-dependent stimulation, only peritoneal memory cells express high levels of the IL-33 receptor and produce IL-5 and IL-13 upon TCR-independent stimulation with IL-33 and IL-7. Most importantly, PC-derived TRM cells are able to mediate anti-helminthic effects by decreasing the fecundity of female worms upon transfer into recipient mice. These results show that nonlymphoid compartments can serve as reservoirs for Th2 memory cells, and furthermore that innate effector function of Th2 memory cells is restricted to CD4⁺ memory T cells residing in the PC.

IL-33 receptor (ST2) deficiency downregulates myeloid precursors, inflammatory NK and dendritic cells in early phase of sepsis.

BACKGROUND: Sepsis is a life-threatening disease mediated by profound disturbances in systemic inflammatory response to infection. IL-33 is multifunctional regulator of numerous aspects of innate and adaptive immune response. The aim of this article was to further evaluate the role of IL-33 receptor (ST2) in different pathways of innate immunity during early polymicrobial sepsis. METHODS: Polymicrobial sepsis was induced using cecal ligation and puncture (CLP) model in ST2 deficient (ST2-/-) and wild type BALB/c mice. Peritoneal and spleen cells were isolated for further phenotyping. Apoptosis was determined by immunohistochemistry and flow cytometry. RESULTS: Deletion of ST2 leads to increased susceptibility to early manifestations of sepsis as evaluated by clinical signs and survival. These are accompanied by decrease in the total number of neutrophils, eosinophils and mast cells in peritoneal cavity 12 h after CLP. In early sepsis there was also low number of precursors of myeloid cells in particular CD11b+Ly6G+Ly6Clow cells in spleen of ST2-/- mice. Although the number of NK cells in the spleen was similar, there were significant differences in the presence of inflammatory IFN-γ and IL-17 producing NK cells. Further, ST2 deletion affects the phenotype and maturation of dendritic cell in sepsis. The total number of dendritic cells in the spleen was lower as well as IL-12 expressing dendritic cells. Finally, there was higher frequency of active caspase-3 positive and early apoptotic cells, in particular CD11c positive cells, in spleen of septic ST2-/- mice. CONCLUSION: Taken together, our data provide the evidence that ST2 deficiency in early phase of sepsis downregulates myeloid precursors, inflammatory NK and dendritic cells.

Comparability of histological outcomes in rats and humans in a hernia model.

BACKGROUND: Hernia repair is one of the most frequently performed operations. In search of the ideal mesh for hernia repair, animal research is required. Although rats are most often used in experimental mesh experiments, no correlation with clinical findings in humans has ever been shown. Therefore, the aim of our study was to investigate whether adhesion formation and foreign body reactions to meshes in rats are comparable with the reactions in humans. MATERIALS AND METHODS: A fixed type of mesh was implanted intraperitoneally in a group of 10 rats and 10 patients undergoing elective, temporary stoma formation. In case of the latter, meshes were placed around the stoma. After a follow-up period of 12 wk in rats and after a median follow-up of 6 mo in humans, samples of the mesh were collected. Adhesion assessments were performed, and (immuno-) histochemical evaluation was performed by a specialized experimental pathologist and an experienced clinical pathologist. RESULTS: After the follow-up period, adhesion formation did not differ significantly between rats and humans. Moreover, general inflammation scores were comparable, although granulocytes and giant cells were more present in rats, compared with humans. On the other hand, the presence of fibrosis was more evident in humans compared with rats. CONCLUSIONS: To our knowledge, this is the first study, which showed that a specific animal model, namely a rat model, correlates with adhesion formation and the foreign body reaction to meshes in humans. It can be recommended to use rats in future experimental mesh for incisional hernia research.