scholarly journals Lamellar Inclusions within Hyperplastic Endoplasmic Reticulum in Benign Mesothelial Cells

2020 ◽  
Vol 64 (6) ◽  
pp. 572-576
Author(s):  
Simon Haefliger ◽  
Deepali Jain ◽  
Thomas Menter ◽  
Tatjana Vlajnic ◽  
Spasenija Savic Prince ◽  
...  

<b><i>Introduction:</i></b> In effusion cytology, mesothelial cells can occasionally present with striking intracytoplasmic accumulation of rod- and crystal-like cytoplasmic lamellar inclusions (LIs). Their nature and function are poorly understood, and their diagnostic relevance is unknown. <b><i>Objective:</i></b> The aim of this study was to explore the nature of LIs in mesothelial cells and determine their prevalence and diagnostic utility in routine practice. <b><i>Material and Method:</i></b> We reviewed a consecutive series of cytological specimens of reactive (<i>n</i> = 102) and malignant effusions (<i>n</i> = 90), respectively. Malignant effusions included malignant mesotheliomas (<i>n</i> = 63) and carcinomas (<i>n</i> = 27). LIs of one effusion were analyzed by electron microscopy (EM). <b><i>Results:</i></b> LIs were found exclusively in benign mesothelial cells in 14% (14/102) of reactive and in 4% (1/27) of malignant effusions with carcinomatosis. They were absent in effusions of malignant mesothelioma. EM revealed mainly straight lamellar, less tubular, structures in cisternae of the hyperplasic rough endoplasmic reticulum (rER). <b><i>Conclusion:</i></b> Cytoplasmic LIs located within hyperplastic rER can be found in up to 14% of effusions restricted to benign mesothelial cells. They can be used as an indirect morphological clue favoring the diagnosis of benign effusion and helping the cytologist to differentiate between reactive and malignant mesothelial cells in daily practice.

Author(s):  
G. D. Gagne ◽  
M. F. Miller ◽  
D. A. Peterson

Experimental infection of chimpanzees with non-A, non-B hepatitis (NANB) or with delta agent hepatitis results in the appearance of characteristic cytoplasmic alterations in the hepatocytes. These alterations include spongelike inclusions (Type I), attached convoluted membranes (Type II), tubular structures (Type III), and microtubular aggregates (Type IV) (Fig. 1). Type I, II and III structures are, by association, believed to be derived from endoplasmic reticulum and may be morphogenetically related. Type IV structures are generally observed free in the cytoplasm but sometimes in the vicinity of type III structures. It is not known whether these structures are somehow involved in the replication and/or assembly of the putative NANB virus or whether they are simply nonspecific responses to cellular injury. When treated with uranyl acetate, type I, II and III structures stain intensely as if they might contain nucleic acids. If these structures do correspond to intermediates in the replication of a virus, one might expect them to contain DNA or RNA and the present study was undertaken to explore this possibility.


2007 ◽  
Vol 79 (8) ◽  
Author(s):  
Marek Winckiewicz ◽  
Alicja Połubińska ◽  
Ryszard Staniszewski ◽  
Andrzej Bręborowicz

Author(s):  
Vitalii Kryvenko ◽  
Olga Vagin ◽  
Laura A. Dada ◽  
Jacob I. Sznajder ◽  
István Vadász

Abstract The Na,K-ATPase establishes the electrochemical gradient of cells by driving an active exchange of Na+ and K+ ions while consuming ATP. The minimal functional transporter consists of a catalytic α-subunit and a β-subunit with chaperon activity. The Na,K-ATPase also functions as a cell adhesion molecule and participates in various intracellular signaling pathways. The maturation and trafficking of the Na,K-ATPase include co- and post-translational processing of the enzyme in the endoplasmic reticulum (ER) and the Golgi apparatus and subsequent delivery to the plasma membrane (PM). The ER folding of the enzyme is considered as the rate-limiting step in the membrane delivery of the protein. It has been demonstrated that only assembled Na,K-ATPase α:β-complexes may exit the organelle, whereas unassembled, misfolded or unfolded subunits are retained in the ER and are subsequently degraded. Loss of function of the Na,K-ATPase has been associated with lung, heart, kidney and neurological disorders. Recently, it has been shown that ER dysfunction, in particular, alterations in the homeostasis of the organelle, as well as impaired ER-resident chaperone activity may impede folding of Na,K-ATPase subunits, thus decreasing the abundance and function of the enzyme at the PM. Here, we summarize our current understanding on maturation and subsequent processing of the Na,K-ATPase in the ER under physiological and pathophysiological conditions. Graphic Abstract


2004 ◽  
Vol 32 (5) ◽  
pp. 655-658 ◽  
Author(s):  
C.E. Jessop ◽  
S. Chakravarthi ◽  
R.H. Watkins ◽  
N.J. Bulleid

Native disulphide bonds are essential for the structure and function of many membrane and secretory proteins. Disulphide bonds are formed, reduced and isomerized in the endoplasmic reticulum of mammalian cells by a family of oxidoreductases, which includes protein disulphide isomerase (PDI), ERp57, ERp72, P5 and PDIR. This review will discuss how these enzymes are maintained in either an oxidized redox state that allows them to form disulphide bonds in substrate proteins or a reduced form that allows them to perform isomerization and reduction reactions, how these opposing pathways may co-exist within the same compartment and why so many oxidoreductases exist when PDI alone can perform all three of these functions.


2021 ◽  
pp. 2100137
Author(s):  
Jeroen L.M. van Doorn ◽  
Francesca Pennati ◽  
Hendrik H.G. Hansen ◽  
Baziel G.M. van Engelen ◽  
Andrea Aliverti ◽  
...  

Respiratory muscle weakness is common in neuromuscular disorders and leads to significant respiratory difficulties. Therefore, reliable and easy assessment of respiratory muscle structure and function in neuromuscular disorders is crucial. In the last decade, ultrasound and MRI emerged as promising imaging techniques to assess respiratory muscle structure and function. Respiratory muscle imaging directly measures the respiratory muscles and, in contrast to pulmonary function testing, is independent of patient effort. This makes respiratory muscle imaging suitable to use as tool in clinical respiratory management and as outcome parameter in upcoming drug trials for neuromuscular disorders, particularly in children. In this narrative review, we discuss the latest studies and technological developments in imaging of the respiratory muscles by US and MR, and its clinical application and limitations. We aim to increase understanding of respiratory muscle imaging and facilitate its use as outcome measure in daily practice and clinical trials.


2018 ◽  
Vol 04 (04) ◽  
pp. e220-e225
Author(s):  
Martijn Marsman ◽  
Denise Özdemir- van Brunschot ◽  
Abdelkarime Jahrome ◽  
Nic Veeger ◽  
Wouter Schuiling ◽  
...  

Introduction In the Netherlands, clopidogrel monotherapy increasingly replaces acetylsalicylic acid and extended release dipyridamole as the first-choice antiplatelet therapy after ischemic stroke. It is unknown whether the risk of peri- and postoperative hemorrhage in carotid artery surgery is higher in patients using clopidogrel monotherapy compared with acetylsalicylic acid and extended release dipyridamole. We therefore retrospectively compared occurrence of perioperative major and (clinical relevant) minor bleedings during and after carotid endarterectomy of two groups using different types of platelet aggregation inhibition after changing our daily practice protocol in our center. Material and Methods A consecutive series of the most recent 80 carotid endarterectomy patients (November 2015–August 2017) treated with the new regime (clopidogrel monotherapy) were compared with the last 80 (January 2012–November 2015) consecutive patients treated according to the old protocol (acetylsalicylic acid and dipyridamole). The primary endpoint was any major bleeding during surgery or in the first 24 to 72 hours postoperatively. Secondary outcomes within 30 days after surgery included minor (re)bleeding postoperative stroke with persistent or transient neurological deficit, persisting or transient neuropraxia, asymptomatic restenosis or occlusion, (transient) headache. Reporting of this study is in line with the ‘Strengthening the Reporting of Observational Studies in Epidemiology’ statement. Results Although statistical differences were observed, from a clinical perspective both patients groups were comparable. Postoperative hemorrhage requiring reexploration for hemostasis occurred in none of the 80 patients in the group of the clopidogrel monotherapy (new protocol) and it occurred in one of the 80 patients (1%) who was using acetylsalicylic acid and dipyridamole (old protocol). In three patients (4%) in the clopidogrel monotherapy and one patient (1%) in the acetylsalicylic acid and extended release dipyridamole protocol an ipsilateral stroke was diagnosed. Conclusion In this retrospective consecutive series the incidence of postoperative ischemic complications and perioperative hemorrhage after carotid endarterectomy (CEA) seemed to be comparable in patients using clopidogrel monotherapy versus acetylsalicylic acid and extended release dipyridamole for secondary prevention after a cerebrovascular event. This study fuels the hypothesis that short- and midterm complications of clopidogrel and the combination acetylsalicylic acid and extended release dipyridamole are comparable.


2007 ◽  
Vol 27 (2_suppl) ◽  
pp. 110-115 ◽  
Author(s):  
Susan Yung ◽  
Chan Tak Mao

♦ Background The introduction of peritoneal dialysis (PD) as a modality of renal replacement therapy has provoked much interest in the biology of the peritoneal mesothelial cell. Mesothelial cells isolated from omental tissue have immunohistochemical markers that are identical to those of mesothelial stem cells, and omental mesothelial cells can be cultivated in vitro to study changes to their biologic functions in the setting of PD. ♦ Method The present article describes the structure and function of mesothelial cells in the normal peritoneum and details the morphologic changes that occur after the introduction of PD. Furthermore, this article reviews the literature of mesothelial cell culture and the limitations of in vitro studies. ♦ Results The mesothelium is now considered to be a dynamic membrane that plays a pivotal role in the homeostasis of the peritoneal cavity, contributing to the control of fluid and solute transport, inflammation, and wound healing. These functional properties of the mesothelium are compromised in the setting of PD. Cultures of peritoneal mesothelial cells from omental tissue provide a relevant in vitro model that allows researchers to assess specific molecular pathways of disease in a distinct population of cells. Structural and functional attributes of mesothelial cells are discussed in relation to long-term culture, proliferation potential, age of tissue donor, use of human or animal in vitro models, and how the foregoing factors may influence in vitro data. ♦ Conclusions The ability to propagate mesothelial cells in culture has resulted, over the past two decades, in an explosion of mesothelial cell research pertaining to PD and peritoneal disorders. Independent researchers have highlighted the potential use of mesothelial cells as targets for gene therapy or transplantation in the search to provide therapeutic strategies for the preservation of the mesothelium during chemical or bacterial injury.


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