scholarly journals Histological features of the mitral valve in normal and opioid exposure in experiment

2019 ◽  
Vol 25 (3) ◽  
pp. 40-44
Author(s):  
L.R. Mateshuk-Vatseba ◽  
R.R. Symivska ◽  
N.V. Belik ◽  
V.V. Piliponova
Keyword(s):  
Endothelial Cells ◽  
Mitral Valve ◽  
Elastic Layer ◽  
Morphological Changes ◽  
Reproductive Age ◽  
Elastic Fibers ◽  
Destructive Effect ◽  
Mitral Valves ◽  
Normal Mitral Valve ◽  
Smooth Myocytes

To date, pathology of the cardiovascular system is the most common, tends to increase, most often leads to disability and mortality of the population at a young working age and is an important medical and social problem. The purpose of the study was to establish the features of micro organization of the mitral valve in white rat in norm and after opioid action. The study material is presented by histological samples of a mitral valve of the white rat. The study was performed on 30 adult white reproductive age rats weighing 160-220 g. The experimental animals were injected intramuscularly 1 time per day for the same period of 42 days (6 weeks) with the opioid drug analgesic “Nalbuphine”. Using histological methods, 30 mitral valves of white rat were examined. Microscopy of histological preparations of the valves of the heart was performed sequentially, assessing the morphological changes in the norm and under the action of the opioid after 6 weeks of the experiment. Emphasis was placed on the presence or absence of endothelial layer, as well as the condition of endothelial cells in normal and at the action of the damaging factor, determining the signs of their dystrophy, desquamation and proliferation. It is established that the normal mitral valve is represented by endocardial folds. The rat endocardium consists of three layers: endothelial (endothelial cells rich layer, attached to the basement membrane), subendothelial (connective tissue rich in fibroblasts) and a muscular-elastic layer (represented by smooth myocytes, plaited collagen fibers). After 6 weeks of administration of Nalbuphine, the mitral valve is in a stage of decompensation, when the outer and inner endothelial layers are destroyed, the endothelial cells are deformed, the subendothelial layer is represented by single bundles of different directions. In the musculo-elastic layer, contact between smooth myocytes and fragmented and thinned, collagen and elastic fibers is lost. This study allows us to conclude on the destructive effect of opioid agents on the valvular apparatus of the heart.

scholarly journals PECULIARITIES OF MORPHOLOGICAL CHANGES OF ENDOTHELIOCYTES AND REMODELING OF THE ARTERIES UNDER THE EXPERIMENTAL HYPERCHOLESTEROLEMIA

2019 ◽  
Vol 72 (5) ◽  
pp. 972-977
Author(s):  
Ihor I. Yuryk ◽  
Yaroslav Ya. Bodnar ◽  
Svitlana V. Trach-Rosolovska ◽  
Olena I. Hladii ◽  
Petro Ya. Bodnar ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Endothelium ◽  
Morphological Changes ◽  
Lymphocytic Infiltration ◽  
Reproductive Age ◽  
Elastic Fibers ◽  
Control Group ◽  
Morphological Marker ◽  
Experimental Hypercholesterolemia ◽  
Lymphocytic Infiltrates

Introduction: Under the conditions of experimental hypercholesterolemia, endothelial dysfunction develops with the morphological marker which is an increase in the number of blood-circulating desquamated endothelial cells (DEC), but this situation needs to be clarified in the development of this pathology in the age aspect. The aim: To find out the features of remodeling of endothelial cells and arteries of the hind limbs in the rats of pre-repopductive and reproductive age with experimental hypercholesterolemia. Materials and methods: The experimental group consisted of 16 animals with biochemically confirmed hypercholesterolemia, which were divided into 2 groups: group 1 – 8 animals, aged 2–3 months, weighing 150–170 grams and group 2 – 8 rats aged from 11 to 11 months weighing 230–250 gram. The control group consisted of rats of the same age of 8 animals in each. Results: Hypercholesterolemia causes damage to the vascular endothelium of the arteries, which is characterized by an increase in the number of desquamated endothelial cells in the peripheral blood. The most circulating blood in desquamated endothelial cells was detected in 45 days of study in animals of reproductive age, where the number of desquamated endothelial cells increased by 2.56 times, and in animals of pre-reproductive age – 2.35 times. Morphological changes were characterized by thickening of the intima of the arteries of the femur, knee and tibia due to swelling of the endothelial cells, their desquamation and proliferative changes in places of preserved vascular endothelium. In response to the deposition of lipids and PAS-positive substrates, cellular reactions appeared as weak lymphocytic infiltration. In addition to hyperlastosis, fragmentation of elastic fibers was revealed. Correlation of intima contributed to the narrowing of vascular lumen. Lipids, xanthoma cells and sour mucopolysaccharides were accumulated in the inner membrane of the arteries. In addition to lymphocytic infiltrates, the amount of collagen fibers in adventitia increased. Conclusions: Under conditions of hypercholesterolemia the number of desquamated endothelial cells in the blood increases, and arterial remodeling is characterized by manifestations of hypertrophic-neoplastic remodeling in rats of pre-reproductive age, and in reproductive animals there were sclerotic and inflammatory changes.

Coaptation Mechanism of Dilated Mitral Valves

2010 ◽  
Author(s):  
Bo Gao ◽  
Zhaoming He
Keyword(s):  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Left Ventricular Dysfunction ◽  
Ventricular Dysfunction ◽  
Left Ventricular ◽  
Functional Mitral Regurgitation ◽  
Common Complication ◽  
Mitral Valves ◽  
Global Left Ventricular ◽  
Normal Mitral Valve

Functional mitral regurgitation, which occurs as a consequence of regional of global left ventricular or global left ventricular dysfunction despite structurally normal mitral valve (MV), is a common complication in patients with ischemic or non-ischemic cardiomyopathies [1].

Total Reconstruction of the Mitral Valve with Autopericardium: Anatomical Study

2002 ◽  
Vol 10 (2) ◽  
pp. 137-140
Author(s):  
Vahe C Gasparyan ◽  
Van S Galstyan
Keyword(s):  
Mitral Valve ◽  
Valve Replacement ◽  
Prosthetic Valve ◽  
Anatomical Study ◽  
Good Alternative ◽  
Native Valve ◽  
Mitral Valves ◽  
Autologous Pericardium ◽  
Total Reconstruction ◽  
Normal Mitral Valve

Mitral valve repair has several advantages over prosthetic valve replacement. A new technique of total reconstruction of the mitral valve with autologous pericardium is described. The native mitral valve leaflets and chordae were excised from 10 human cadaver hearts, in the same way as for prosthetic valve replacement. The dimensions of the physiologically normal mitral valve were used to calculate the parameters for tailoring a corresponding new valve. Autologous pericardium was fixed in 0.625% glutaraldehyde solution for 10 minutes. The calculated parameters of the mitral valve were marked on the pericardium. The new valve was fashioned and inserted in the native valve position. Hydraulic probes showed good competence in all 10 reconstructed mitral valves. This method might be a good alternative to prosthetic valve replacement.

Hemodynamics of the Mitral Valve Under Edge-to-Edge Repair: An In Vitro Steady Flow Study

2009 ◽  
Vol 131 (5) ◽  
Author(s):  
Liang Shi ◽  
Zhaoming He
Keyword(s):  
Mitral Valve ◽  
Left Ventricle ◽  
Position Effect ◽  
Maximum Velocity ◽  
Central Position ◽  
Effective Orifice Area ◽  
Orifice Area ◽  
Mitral Valves ◽  
Repair Technique ◽  
Normal Mitral Valve

Edge-to-edge repair (ETER) is a mitral valve repair technique that restores valvular competence by suturing together the free edges of two leaflets. This repair technique alters mitral valve inflow and thus left ventricle hemodynamics during diastole. Our objective was to investigate fluid mechanics immediately downstream of the mitral valve under ETER during diastole. Fresh porcine mitral valves of the annulus size M32 with chordae removed were installed into a steady flow loop simulating a peak diastolic inflow through the mitral valve. Digital particle image velocimetry was used to measure the velocity field immediately downstream of the mitral valve under normal and ETER conditions. First, to study the suture length effect, suture was applied in the central position of the leaflet edge with suture lengths of 3 mm, 6 mm, and 9 mm, respectively. Then, 3 mm suture was set in the central, lateral, and commissural positions of the leaflet edge to study the suture position effect. Flow rate was 15 l/min. Velocity, Reynolds shear stress (RSS), and effective orifice area were assessed. A total of five mitral valves were tested. The normal mitral valve without the ETER had one jet downstream of the valve, but the mitral valve with the central or lateral sutures under the ETER had two jets downstream of the valve with a recirculation region downstream of the suture. The maximum velocity, the maximum RSS in the jets, the pressure drop across the mitral valve, and the jet deflection angle increased with the increase in suture length in the central position. When the suture position effect was investigated with the 3 mm suture, the maximum velocity, the maximum RSS, and the pressure drop across the valve in the central suture position were greater than those of the lateral and the commissural suture positions. The lateral suture demonstrated major and minor jets with the greater maximum velocity and maximum RSS in the major jet. When the suture was in the commissural position, the flow field downstream of the mitral valve was similar to that of the normal mitral valve without the ETER. The effective orifice area was smallest when the suture was applied in the central position as compared with other suture positions. Both suture length and position have an important impact on fluid mechanics downstream of the mitral valve under the ETER in terms of flow pattern, maximum velocity, and RSS distribution. The altered hemodynamics of the mitral valve and thus of the left ventricle by the ETER may change mitral valve and left ventricle function.

scholarly journals The morphometric measurements of the gross structural changes of mitral valve in valvular stenosis with or without regurgitation

2015 ◽  
Vol 9 (1) ◽  
pp. 7-11
Author(s):  
Golam Mohammad Kibria
Keyword(s):  
Mitral Valve ◽  
Adult Male ◽  
Structural Changes ◽  
Effective Orifice Area ◽  
Chordae Tendineae ◽  
Morphometric Measurements ◽  
Mitral Valves ◽  
Replacement Surgery ◽  
Valvular Stenosis ◽  
Normal Mitral Valve

Rheumatic mitral stenosis is still a cardiac problem in developing countries. Reconstructive and replacement surgery of the diseased valves are often needed. Most of the studies on stenotic mitral valves are echocardiographic one. Morphometric measurements of the stenotic mitral valve and comparison with that in the normal mitral valve is done in this study. Thirty seven hearts of normal adult-male unclaimed dead-bodies from the mortuary of Forensic Medicine, Dhaka Medical College, Dhaka; and twelve surgically excised stenotic mitral valves of the adult-male cardiac patients from the National Institute of Cardiovascular Diseases, Dhaka, Bangladesh were studied in fresh condition. The detail morphometric findings were compared between two groups. Though the total annular circumference was similar in both groups, yet the effective orifice area reduced significantly in stenotic valves. The anterior leaflet-area was increased, but the posterior leaflet-area was decreased in the stenotic valves. The thickness of the stenotic leaflets and chordae tendineae were increased compared to that in normal valves. The knowledge of the pathological changes of the valves would help to understand the exact pathophysiological mechanisms involved in the cardiac valve diseases.Faridpur Med. Coll. J. 2014;9(1): 7-11

scholarly journals Myxomatous Mitral Valve Disease with Mitral Valve Prolapse and Mitral Annular Disjunction: Clinical and Functional Significance of the Coincidence

2021 ◽  
Vol 8 (2) ◽  
pp. 9
Author(s):  
Nina C. Wunderlich ◽  
Siew Yen Ho ◽  
Nir Flint ◽  
Robert J. Siegel
Keyword(s):  
Mitral Valve ◽  
Mitral Valve Disease ◽  
Morphological Changes ◽  
Morphological Characteristics ◽  
Mitral Annulus ◽  
Ventricular Myocardium ◽  
Left Ventricular ◽  
Valve Disease ◽  
Left Ventricular Myocardium ◽  
Basal Portion

The morphological changes that occur in myxomatous mitral valve disease (MMVD) involve various components, ultimately leading to the impairment of mitral valve (MV) function. In this context, intrinsic mitral annular abnormalities are increasingly recognized, such as a mitral annular disjunction (MAD), a specific anatomical abnormality whereby there is a distinct separation between the mitral annulus and the left atrial wall and the basal portion of the posterolateral left ventricular myocardium. In recent years, several studies have suggested that MAD contributes to myxomatous degeneration of the mitral leaflets, and there is growing evidence that MAD is associated with ventricular arrhythmias and sudden cardiac death. In this review, the morphological characteristics of MAD and imaging tools for diagnosis will be described, and the clinical and functional aspects of the coincidence of MAD and myxomatous MVP will be discussed.

scholarly journals Use of a Sandwich Technique to Repair a Left Ventricular Rupture after Mitral Valve Replacement

2014 ◽  
Vol 41 (2) ◽  
pp. 195-197 ◽  
Author(s):  
Myles E. Lee ◽  
Mallika Tamboli ◽  
Anthony W. Lee
Keyword(s):  
Mitral Valve ◽  
Valve Replacement ◽  
Mitral Valve Replacement ◽  
Left Ventricular ◽  
Left Ventricular Aneurysm ◽  
Sandwich Technique ◽  
Ventricular Rupture ◽  
Left Ventricular Rupture ◽  
Valve Function ◽  
Normal Mitral Valve

One difficulty with external repair of left ventricular rupture after mitral valve replacement is collateral bleeding in friable myocardium adjacent to the rupture. The bleeding is caused by tension on the closing sutures, whether or not pledgets have been used. We report the case of a 69-year-old woman who underwent an uneventful mitral valve replacement. After cardiopulmonary bypass was terminated, brisk bleeding started from high in the posterior left ventricular wall, typical of a type III defect. We undertook external repair, placing a plug of Teflon felt into the cavity of the rupture and sandwiching it into place with pledgeted mattress and figure-of-8 sutures. The space occupied by the plug decreased the distance needed to obliterate the defect and thereby reduced the tension on the sutures necessary to achieve hemostasis. This simple technique enabled closure of the defect and avoided collateral tears that would have compromised an otherwise successful repair. Two years postoperatively, the patient had normal mitral valve function and no left ventricular aneurysm. In addition to reporting the patient's case, we review the types of left ventricular rupture that can occur during mitral valve replacement and discuss the various repair options.

Distinct signals via Rho GTPases and Src drive shape changes by thrombin and sphingosine-1-phosphate in endothelial cells

2002 ◽  
Vol 115 (12) ◽  
pp. 2475-2484 ◽  
Author(s):  
Valérie Vouret-Craviari ◽  
Christine Bourcier ◽  
Etienne Boulter ◽  
Ellen Van Obberghen-Schilling
Keyword(s):  
Endothelial Cells ◽  
Rho Gtpases ◽  
Actin Polymerization ◽  
Morphological Changes ◽  
Umbilical Vein ◽  
Cell Spreading ◽  
Actin Binding ◽  
Sphingosine 1 Phosphate ◽  
And Migration ◽  
Umbilical Vein Endothelial Cells

Soluble mediators such as thrombin and sphingosine-1-phosphate regulate morphological changes in endothelial cells that affect vascular permeability and new blood vessel formation. Although these ligands activate a similar set of heterotrimeric G proteins, thrombin causes cell contraction and rounding whereas sphingosine-1-phosphate induces cell spreading and migration. A functional requirement for Rho family GTPases in the cytoskeletal responses to both ligands has been established, yet the dynamics of their regulation and additional signaling mechanisms that lead to such opposite effects remain poorly understood. Using a pull-down assay to monitor the activity of Rho GTPases in human umbilical vein endothelial cells, we find significant temporal and quantitative differences in RhoA and Rac1 activation. High levels of active RhoA rapidly accumulate in cells in response to thrombin whereas Rac1 is inhibited. In contrast, sphingosine-1-phosphate addition leads to comparatively weak and delayed activation of RhoA and it activates Rac1. In addition, we show here that sphingosine-1-phosphate treatment activates a Src family kinase and triggers recruitment of the F-actin-binding protein cortactin to sites of actin polymerization at the rim of membrane ruffles. Both Src and Rac pathways are essential for lamellipodia targeting of cortactin. Further, Src plays a determinant role in sphingosine-1-phosphate-induced cell spreading and migration. Taken together these data demonstrate that the thrombin-induced contractile and immobile phenotype in endothelial cells reflects both robust RhoA activation and Rac inhibition, whereas Src- and Rac-dependent events couple sphingosine-1-phosphate receptors to the actin polymerizing machinery that drives the extension of lamellipodia and cell migration.

Endothelial microparticles increase in mitral valve disease and impair mitral valve endothelial function

2013 ◽  
Vol 304 (7) ◽  
pp. E695-E702 ◽  
Author(s):  
Hong-Bo Ci ◽  
Zhi-Jun Ou ◽  
Feng-Jun Chang ◽  
Dong-Hong Liu ◽  
Guo-Wei He ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Endothelial Cells ◽  
Mitral Valve ◽  
Mitral Regurgitation ◽  
Mitral Valve Disease ◽  
Healthy Subjects ◽  
Heat Shock Protein 90 ◽  
Valve Disease ◽  
No Production ◽  
Endothelial Microparticles

Mitral valve endothelial cells are important for maintaining lifelong mitral valve integrity and function. Plasma endothelial microparticles (EMPs) increased in various pathological conditions related to activation of endothelial cells. However, whether EMPs will increase in mitral valve disease and their relationship remains unclear. Here, 81 patients with mitral valve disease and 45 healthy subjects were analyzed for the generation of EMPs by flow cytometry. Human mitral valve endothelial cells (HMVECs) were treated with EMPs. The phosphorylation of Akt and endothelial nitric oxide synthase (eNOS), the association of eNOS and heat shock protein 90 (HSP90), and the generation of nitric oxide (NO) and superoxide anion (O2˙−) were measured. EMPs were increased significantly in patients with mitral valve disease compared with those in healthy subjects. EMPs were negatively correlated with mitral valve area in patients with isolated mitral stenosis. EMPs were significantly higher in the group with severe mitral regurgitation than those in the group with mild and moderate mitral regurgitation. Furthermore, EMPs were decreased dramatically in both Akt and eNOS phosphorylation and the association of HSP90 with eNOS in HMVECs. EMPs decreased NO production but increased O2˙− generation in HMVECs. Our data demonstrated that EMPs were significantly increased in patients with mitral valve disease. The increase of EMPs can in turn impair HMVEC function by inhibiting the Akt/eNOS-HSP90 signaling pathway. These findings suggest that EMPs may be a therapeutic target for mitral valve disease.

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