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Elastic Lamina (elastic + lamina)

Distribution by Scientific Domains
Medical Sciences70%
Life Sciences30%

Kinds of Elastic Lamina

  • internal elastic lamina
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    Selected Abstracts

    Pathology of lethal peripartum broad ligament haematoma in 31 Thoroughbred mares

    EQUINE VETERINARY JOURNAL, Issue 6 2010
    T. UENO
    Summary Reasons for performing study: Broad ligament haemorrhage in peripartum mares is a life-threatening disease and there are few reports on the aetiology and pathogenesis of broad ligament haematoma. Objectives: To obtain information regarding the sites for the early diagnosis and pathogenesis of broad ligament haematoma of mares. Methods: Thirty-one mares that died of broad ligament haematoma peripartum were examined pathologically for bleeding sites. The arterial distribution of 5 young mares with several parities served as negative controls. Results: Age and/or multiparity were the predisposing factors for the disease. Arterial injuries were most commonly observed in the uterine artery (24 of 31 mares). Among these, the proximal uterine artery that lies within 15 cm of the bifurcation of the iliac artery was the most frequent site for rupture (18 mares). The lesions occurred preferentially at the bifurcations, lateral part of curvatures and abrupt flexures of the artery. The morphology of the injuries was classified into 3 types: ruptures with and without longitudinal fissures, and transections. Histologically, the arterial wall adjacent to the rupture showed atrophy of smooth muscle cells with fibrosis of the tunica media and disruption and/or calcification of the internal elastic lamina. Conclusions: Arterial injuries that led to broad ligament haematoma in peripartum mares occurred most frequently in the proximal uterine artery, and atrophy of smooth muscle cells with fibrosis of the arterial wall was as one of the predisposing factors in aged and multiparous mares. Potential relevance: Monitoring small aneurysms, mural tearing, medial fibrosis at the proximal uterine artery by transrectal echography could provide useful information for the early diagnosis and possible prevention of broad ligament haematoma of peripartum mares. [source]

    Methylenetetrahydrofolate reductase gene C677T mutation is related to the defects in the internal elastic lamina of the artery wall

    EUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 12 2002
    P. Hämelahti
    Abstract Background The C677T mutation of the methylenetetrahydrofolate reductase (MTHFR) gene leads to C/C, C/T and T/T genotypes, which affect the plasma homocysteine concentration in humans. In mini-pigs, high serum homocysteine levels are associated with defects in the internal elastic lamina (IEL) of the artery wall, which are apparently related to the migration of smooth muscle cells into the intima during atherogenesis. We studied the association between the MTHFR genotypes and the number of gaps in the IEL in the wall of the five major abdominal arteries. Materials and methods The autopsy study included 123 subjects (90 males and 33 females) aged 18,93. For the light microscopy, a 0·5 cm circular segment of the coeliac, the superior mesenteric, the inferior mesenteric and the renal arteries were cut and embedded in paraffin blocks. The circumference of the IEL, the thickness of the intima and the number of the gaps per millimetre in the IEL were measured by MOP 3 image analysis. Results The T-allele carriers (C/T and T/T) of the MTHFR gene had significantly less gaps in the IEL than the subjects with the C/C genotype in the superior mesenteric and in the left renal arteries (2·02 ± 2·25 vs. 2·53 ± 1·89, P < 0·04 and 0·56 ± 1·09 vs. 1·82 ± 2·66, P < 0·02, respectively). The trend was similar for the coeliac and the right renal arteries. Conclusions Our result suggests that MTHFR polymorphism may be involved in the fragmentation of the IEL. [source]

    Spatial separation of endothelial small- and intermediate-conductance calcium-activated potassium channels (KCa) and connexins: possible relationship to vasodilator function?

    JOURNAL OF ANATOMY, Issue 5 2006
    Shaun L. Sandow
    Abstract Activation of endothelial cell small- (S) and intermediate- (I) conductance calcium-activated potassium channels (KCa) and current or molecular transfer via myoendothelial gap junctions underlies endothelium-derived hyperpolarization leading to vasodilation. The mechanism underlying the KCa component of vasodilator activity and the characteristics of gap junctions are targets for the selective control of vascular function. In the rat mesenteric artery, where myoendothelial gap junctions and connexin (Cx) 40 are critical for the transmission of the endothelial cell hyperpolarization to the smooth muscle, SKCa and IKCa provide different facets of the endothelium-derived hyperpolarization response, being critical for the hyperpolarization and repolarization phases, respectively. The present study addressed the question of whether this functional separation of responses may be related to the spatial localization of the associated channels? The distribution of endothelial SKCa and IKCa and Cx subtype(s) were examined in the rat mesenteric artery using conventional confocal and high-resolution ultrastructural immunohistochemistry. At the internal elastic lamina,smooth muscle cell interface at internal elastic lamina holes (as potential myoendothelial gap junction sites), strong punctate IKCa, Cx37 and Cx40 expression was present. SKCa, Cx37, Cx40 and Cx43 were localized to adjacent endothelial cell gap junctions. High-resolution immunohistochemistry demonstrated IKCa and Cx37-conjugated gold to myoendothelial gap junction-associated endothelial cell projections. Clear co-localization of KCa and Cxs suggests a causal relationship between their activity and the previously described differential functional activation of SKCa and IKCa. Such precise localizations may represent a selective target for control of vasodilator function and vascular tone. [source]

    Acute and Chronic Effects of Extensive Radiofrequency Lesions in the Canine Caval Veins: Implications for Ablation of Atrial Arrhythmias

    PACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 12 2006
    GUILHERME FENELON M.D.
    Background: Although radiofrequency (RF) ablation within the caval veins has been increasingly used to treat a variety of atrial tachyarrhythmias, the consequences of RF ablation in the caval veins are unknown. We explored the acute and chronic angiographic and pathological effects of extensive RF ablation in the caval veins. Methods: Under fluoroscopy guidance, conventional (4 mm tip, 60°C, 60 seconds) RF applications (n = 6,7) were delivered in each vena cava (from ±2 cm into the vein to the veno-atrial junction) of 15 dogs (10 ± 3 kg). Animals were killed 1 hour and 5 weeks after ablation for histological analysis. Angiography was performed before ablation (acute dogs only) and at sacrifice to assess the degree of vascular stenosis. Results: In acute dogs (n = 5), luminal narrowing was noted in 10/10 (100%) targeted veins (mild in two; moderate in three and severe in five, including two total occlusions). In the six chronic animals that completed the protocol (four died during follow-up), stenosis was also observed in 12/12 (100%) ablated veins (mild in six; moderate in four and severe in two). Of these, one superior vena cava was suboccluded with development of extensive collateral circulation. Histologically, acute lesions displayed typical transmural coagulative necrosis, whereas chronic lesions revealed intimal proliferation, necrotic muscle replaced with collagen, endovascular contraction, and disruption and thickening of the internal elastic lamina. Conclusion: In this model, extensive RF ablation in the caval veins may result in significant vascular stenosis. These findings may have implications for catheter ablation of arrhythmias originating within the caval veins. [source]

    Hamartomatous endocervical polyp with heterologous mesenchymal tissue

    PATHOLOGY INTERNATIONAL, Issue 4 2001
    dvan Ilhan
    We present an endocervical polyp with heterologous elements. Although a few neoplastic cervical lesions with cartilaginous and adipocytic heterologous tissue have been reported, an endocervical polyp with heterologous cartilage and adipose tissue has not been reported before our case. The patient was a 33-year-old woman who presented with abnormal uterine bleeding. On physical examination, there were no remarkable findings other than a cervical polyp protruding into the cervical canal. The polyp was removed. Pathological examination revealed an endocervical polyp with typical epithelial features. The stroma of the polyp contained mature cartilage islands and adipose tissue. There were also many thick-walled vascular structures. Neither stromal periglandular condensation nor atypia was found. Mitotic figures were not observed. Arteriolar structures did not contain internal elastic lamina. In our opinion, these pathological findings are all consistent with a hamartomatous lesion rather than with a true neoplasm. [source]

    Morphological Changes in the Chicken Ductus Arteriosi During Closure at Hatching

    THE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 8 2008
    Candace Belanger
    Abstract The chicken embryo has two functioning ductus arteriosi (DA) during development. These blood vessels connect the pulmonary arteries to the descending aorta providing a right-to-left shunt of blood away from the nonrespiring lungs and to the systemic circuit and chorioallanotic membrane. The DA consists of two distinct tissue types along its length, a muscular proximal portion and an elastic distal portion. During hatching, the DA must close for proper separation of systemic and pulmonary circulation. We examined the morphological changes of the chicken DA before, during, and after hatching. Occlusion of the proximal DA began during external pipping and was complete at hatching. Anatomical remodeling began as early as external pipping with fragmentation of the internal elastic lamina and smooth muscle actin appearing in the neointimal zone. By day 2 posthatch, the proximal DA lumen was fully occluded by endothelial cells and smooth muscle actin positive cells. In contrast, the distal DA was not fully occluded by day 2 posthatch. Increases in Po2 of the blood serves as the main stimulus for closure of the mammalian DA. The responsiveness of the chicken proximal DA to oxygen increased during hatching, peaking during external pipping. This peak correlated with an increase in blood gas Po2 and the initial occlusion of the vessel. The distal portion remained unresponsive to oxygen throughout hatching. In conclusion, the chicken DA begins to close during external pipping when arterial Po2 increases and vessel tone is most sensitive to oxygen. Anat Rec, 291:1007,1015, 2008. © 2008 Wiley-Liss, Inc. [source]

    Assessment of Carotid Artery Invasion in Patients With Head and Neck Cancer

    THE LARYNGOSCOPE, Issue 3 2000
    George H. Yoo MD
    Abstract Purpose Define radiological and histological features in which patients with head and neck cancer would benefit from a carotid artery resection. Resection of the carotid artery has been advocated for local control of advanced squamous cell carcinoma of the head and neck. To provide appropriate preoperative counseling and optimize the utilization of resources, the criteria for patient selection has to be defined. Methods Thirty-four patients underwent carotid artery resection based on the clinical impression of tumor fixation. Eighteen and 28 patients were evaluated using computed tomography (CT) and histological analysis, respectively. The distance between the tumor cells and external elastic lamina was measured. CT scans were examined to determine the circumference of tumor attachment around the carotid artery. Results Clinical assessment predicted tumor within 1.8 mm of the carotid artery in 68% of cases. The overall survival for patients with tumor greater than 1.8 mm (N = 9) was better than that of patients with less (N = 19) than 1.8 mm (33.3% vs. 5.3%; median 24 versus 9 mo, P = .0899). Three of six patients (50%) with less than 180° circumference tumor attachment had tumor within 1.8 mm from the external elastic lamina. Eight of twelve patients (67%) with tumors encompassing more than 180° of the artery wall had tumor within 1.8 mm from the external elastic lamina. The overall survival rates for patients with tumor attachment greater and less than 180° were 8.3% and 33%, respectively. Discussion Tumor invasion into the carotid artery was the strongest predictor of outcome. Clinical assessment was as predictive as CT for tumor invasion. If tumor involvement of the carotid artery is less than 180°, peeling the tumor is an alternative to carotid artery resection. [source]

    GENETIC INFLUENCES ON THE ARTERIAL WALL

    CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 7 2007
    Bronwyn Kingwell
    SUMMARY 1Arterial stiffness, which has independent predictive value for cardiovascular events, seems to have a genetic component, largely independent of the influence of blood pressure and other cardiovascular risk factors. 2In animal models of essential hypertension (stroke-prone spontaneously hypertensive rats and spontaneously hypertensive rats), structural modifications of the arterial wall include an increase in the number of elastin,smooth muscle cell connections and smaller fenestrations of the internal elastic lamina, possibility leading to redistribution of the mechanical load towards elastic materials. These modifications may give rise to mechanisms explaining why changes in arterial wall material accompanying wall hypertrophy in these animals are not associated with an increase in arterial stiffness. 3In monogenic connective tissue diseases (Marfan, Williams and Ehlers,Danlos syndromes) and the corresponding animal models, precise characterization of the arterial phenotype makes it possible to determine the influence of abnormal, genetically determined, wall components on arterial stiffness. 4Such studies have highlighted the role of extracellular matrix signalling in the vascular wall and have shown that elastin and collagen not only display elasticity or rigidity, but are also involved in the control of smooth muscle cell function. 5These data provide strong evidence that arterial stiffness is affected by the amount and density of stiff wall material and the spatial organization of that material. [source]

    Morphological Investigation of Carotid Body and Its Arteries in Rabbits

    ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 5 2002
    E. Unur
    Summary The purpose of this study was to determine the morphology of the rabbit carotid body and its artery at the light microscopy level. The carotid body was situated between the internal and external carotid arteries after the bifurcation point of the common carotid artery. The carotid body was usually found to be a single, ovoid tissue mass but, in some cases it consisted of two or three parts. More carotid bodies were supplied by a single carotid body artery (glomic artery) which arose from the common carotid artery or the internal or external carotid arteries near the bifurcation point of the common carotid artery. In only one case were there two arteries which arose from opposite sides of the external carotid artery at its origin. There was a distinguishable sinus (glomic sinus) at the origin of the glomic artery. This artery had a thin wall with elastic laminae in the sinus area which become thinner distal to the sinus. [source]