Tissue remodeling macrophages morphologically dominate at the interface of polypropylene surgical meshes in the human abdomen

Background Mesh implants are widely used to reinforce the abdominal wall, although the inevitable inflammatory foreign body reaction (FBR) at the interface leads to complications. Macrophages are suspected to regulate the subsequent scar formation, but it is still unclear whether adequate fibrous scar formation with collagen deposition depends mainly on the presence of M1 or M2 macrophages. Methods This study investigated the FBR to seven human polypropylene meshes, which were removed after a median incorporation time of 1 year due to the primary complaint of recurrence. Using immunofluorescence, the FBR was examined in six regional zones with increasing distance from the mesh fibers up to 350 µm, based on the cell densities, macrophage M1 (CD86) and M2 (CD163, CD206) phenotypes, deposition of collagen-I and -III, and expression of matrix metalloproteinase-2 (MMP-2) and -8 as indicator of collagen degradation. Results All mesh–tissue complexes demonstrated a decrease in cell density and macrophages with distance to the mesh fibers. Overall, about 60% of the macrophages presented an M2 phenotype, whereas only 6% an M1 phenotype. Over 70% of macrophages showed co-expression with collagen-I or -III and over 50% with MMP-2. Conclusions The chronic FBR to polypropylene meshes is associated with an M2 macrophage response, which is accompanied by collagen deposition and MMP-2 expression. These findings challenge the idea that mainly M1 macrophages are related to inflammation and highlights that iatrogenic attempts to polarize these cells towards the M2 phenotype may not be a solution to ameliorate the long-term foreign body reaction

Bias-Variation Dilemma Challenges Clinical Trials: Inherent Limitations of Randomized Controlled Trials and Meta-Analyses Comparing Hernia Therapies

Purpose: Evaluation of hernia therapies according to the current rules of Evidence Based Medicine is widely reduced to results of RCTs or meta-analyses. RCTs have been accepted as a most important tool to confirm a superior effect of an intervention. Unfortunately, in hernia surgery, comparisons of RCTs and correspondingly their use in meta-analyses, are not, surprisingly often, able to confirm any significant impact of a specific procedure due to intrinsic restrictions in a multi-causal\ud setting with its web of influences. Methods: Based on our own experiences of clinical studies in surgery, the present article outlines several situations, with their respective reasons, which argue the severe limitations of RCTs and meta-analysis to define an optimum treatment. Results: Metaanalyses accumulate the variations of each trial, which then may cover any clear causal relationship. RCTs usually are dealing with subgroups of standard patients thus excluding the majority of our patients. Low statistical power of current cohort sizes restricts the analysis of subgroups or of effects with low incidences. Simple comparisons of means frequently are hampered by nonlinear relationships to outcome. The relevance of a specific variable is difficult to separate from other influences. The limited surveillance period of studies ignores a delayed change in outcome. Randomization cannot guarantee a standardized patient’s condition. All the arguments have to be considered as a crucial and fundamental consequence of the bias-variance dilemma or principle of uncertainty in medicine, and underline the many limitations of RCTs to evaluate any specific impact of hernia therapies on e.g. infection, pain or recurrence. Conclusions: Many surgical issues\ud cannot be and should not be investigated by RCTs, in particular, if a marked patients’ heterogeneity\ud has to be considered or the low incidences of the outcome readout cannot be addressed with sufficient statistical power without getting lost in the variation mire. Registries with their non-restricted data-acquisition should be regarded as reliable alternatives for postoperative outcome quality surveillance studies

Hernia fibroblasts lack β-estradiol induced alterations of collagen gene expression

BACKGROUND: Estrogens are reported to increase type I and type III collagen deposition and to regulate Metalloproteinase 2 (MMP-2) expression. These proteins are reported to be dysregulated in incisional hernia formation resulting in a significantly decreased type I to III ratio. We aimed to evaluate the β-estradiol mediated regulation of type I and type III collagen genes as well as MMP-2 gene expression in fibroblasts derived from patients with or without history of recurrent incisional hernia disease. We compared primary fibroblast cultures from male/female subjects without/without incisional hernia disease. RESULTS: Incisional hernia fibroblasts (IHFs) revealed a decreased type I/III collagen mRNA ratio. Whereas fibroblasts from healthy female donors responded to β-estradiol, type I and type III gene transcription is not affected in fibroblasts from males or affected females. Furthermore β-estradiol had no influence on the impaired type I to III collagen ratio in fibroblasts from recurrent hernia patients. CONCLUSION: Our results suggest that β-estradiol does not restore the imbaired balance of type I/III collagen in incisional hernia fibroblasts. Furthermore, the individual was identified as an independent factor for the β-estradiol induced alterations of collagen gene expression. The observation of gender specific β-estradiol-dependent changes of collagen gene expression in vitro is of significance for future studies of cellular response

Особенности и закономерности изменения восстановлености углей башкирского яруса Западного Донбасса

В статье приведена детальная петрографическая характеристика углей башкирского яруса Западного Донбасса. Проведена классификация по восстановлености в соответствии с петрографическими типами. Установлены стратиграфические и площадные закономерности изменения степени восстановлености.У статті наведена детальна петрографічна характеристика вугілля башкирського ярусу Західного Донбасу. Проведена класифікація відновленості, згідно з петрографічними типами. Встановлені стратиграфічні та просторові закономірності зміни ступеню відновленості.The article gives detailed petrographic characteristics of coal of Bashkirian formation of Western Donbas. The classifications for recovery in accordance with petrographic types are given. The stratigraphic and areal patterns of change in the degree of recovery are established

Совершенствование технологий обработки призабойной зоны нефтедобывающих скважин на нефтяном месторождении "Белый Тигр" (Вьетнам)

Объектом исследования являются методы интенсификации притока на нефтяном месторождении "Белый Тигр", расположенном в Кыулонгской впадине на шельфе Вьетнама. Цель работы – рассматривание основных методов воздействия на призабойную зону скважины и анализ технологии и техники обработки призабойной зоны скважин на конкретной скважине месторождения "Белый Тигр". Область применения: месторождения с трудноизвлекаемыми запасами нефти и низкопроницаемыми коллекторами. Экономическая эффективность значимость работы: интенсификация притока продукции на разрабатываемых месторождениях методом обработки ПЗП нефтекислотной эмульсией является экономически выгодным.The object of the study are methods of intensifying the inflow of the "White Tiger" oil field, located in the Kyulong depression on the Vietnamese shelf. The aim of the work is to examine the main methods of impact on the bottomhole well zone and to analyze the technology and techniques for treating the bottomhole well zone at a particular well of the White Tiger field. Field of application: deposits with hard-to-recover oil reserves and low-permeability reservoirs Economic significance of the work: intensification of the inflow of products at the developed fields by the method of processing PZP with an oil-acid emulsion is economically profitable

Использование метода моделирования ситуаций при обучении студентов вуза английскому языку

В статье описывается опыт проведения занятий по английскому языку у студентов второго курса направления "Горное дело" с использованием современного активного метода обучения case study. Отмечаются преимущества применения технологии моделирования ситуации при преподавании профессионально-ориентированного курса английского языка в вузе

Characterization of innate and adaptive immune cells involved in the foreign body reaction to polypropylene meshes in the human abdomen

Background Polypropylene (PP) mesh is widely used to reinforce tissues. The foreign body reaction (FBR) to the implant is dominated by innate immune cells, especially macrophages. However, considerable numbers of adaptive immune cells, namely T cells, have also been regularly observed, which appear to play a crucial role in the long-term host response. Methods This study investigated the FBR to seven human PP meshes, which were removed from the abdomen for recurrence after a median of one year. Using immunofluorescence microscopy, the FBR was examined for various innate (CD11b+ myeloid, CD68+ macrophages, CD56+ NK) and adaptive immune cells (CD3+ T, CD4+ T-helper, CD8+ cytotoxic, FoxP3+ T-regulatory, CD20+ B) as well as “conventional” immune cells (defined as cells expressing their specific immune cell marker without co-expressing CD68). Results T-helper cells (19%) and regulatory T-cells (25%) were present at comparable rates to macrophages, and clustered significantly toward the mesh fibers. For all cell types the lowest proportions of “conventional” cells (< 60%) were observed at the mesh–tissue interface, but increased considerably at about 50–100 µm, indicating reduced stimulation with rising distance to the mesh fibers. Conclusion Both innate and adaptive immune cells participate in the chronic FBR to PP meshes with T cells and macrophages being the predominant cell types, respectively. In concordance with the previous data, many cells presented a “hybrid” pattern near the mesh fibers. The complexity of the immune reaction seen within the foreign body granuloma may explain why approaches focusing on specific cell types have not been very successful in reducing the chronic FBR