Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0022116 (ischemia)
 91,303 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Vessels of the microcirculatory bed of the heart in myocardial infarction were studied on the basis of the material of 21 section observations using histological, histochemical methods and the technique of impregnation of films of the epicardium developed by V. V. Kupriyanov. In the ischemic stage in the zone of ischemia and in perifocal areas there were noted signs of increased vascular permeability and impairment of hemodynamics: plethora of the venous department of the microcirculatory system, stasis of the blood in capillaries, spasm and paresis of vessels of the microcirculation. In the necrotic stage in the zone of necrosis there were observed destruction of vessels of the microcirculatory bed; in the peri-infarction zone--drastic plethora of veins, venules and capillaries, higher vascular permeability, leucostasis, leucopedesis, perivascular cellular infiltrates, destruction of vessels of the microcirculatory bed, dilatation of lymphatic vessels; in the intact zone--venous plethora and elevated permeability. In cases of shocks and collapses in vessels of the microcirculatory bed of the heart beyond the zone of necrosis aggregations of erythrocytes were found. In the reparative stage newly formed vessels in the granulation tissue were observed; In the post-infarction scars sinusoid vascular cavities and arteries of the closing type were noted.
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PMID:[Vessels of the microcirculatory bed of the heart in myocardial infarction]. 122 73

Twelve spontaneously delivered, normally suckled, small-for-gestational-age (weighing 756 to 1,213 g) neonatal piglets were used to assess the role of the mesenteric vasculature in the pathogenesis of neonatal necrotizing enterocolitis (NEC) by producing intestinal ischemia. Component vessels (arteries, veins, lymphatics) of the mesenteric vascular arcades were variously occluded by ligation for 48 hours. Nine adjacent vessels of the same type or nine adjacent combinations of vessels were occluded in piglets 12 to 18 hours postpartum. Arterial plus lymphatic ligation induced lesions showing the complete histopathological spectrum of NEC (mucosal stripping, hemorrhage, submucosal disruption and destruction, full-thickness necrosis, inflammatory infiltration) including pneumatosis intestinalis. Two of the lowest birth weight animals produced complete NEC in response to lymphatic ligation alone. A condition consistent with "prepneumatosis" was found when lymphatics only were ligated. The distended lymphatic vessels in the submucosa resembled pneumatosis with reference to shape size and distribution, but contained milk-derived lipids, some proteins and lymph but no gas. Arterial ligation alone induced NEC-like lesions without pneumatosis. Venous ligation alone induced minor congestive/hemorrhagic lesions. Pneumatosis appears to originate in the lymphatic vessels of the submucosa in this experimental model of NEC. Lymphatic occlusion alone can cause complete NEC in very SGA neonatal piglets. Arterial plus lymphatic occlusion produces a unique combination of specific pathology resembling human NEC.
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PMID:The role of lymphatics in the pathogenesis of pneumatosis in experimental bowel ischemia. 150 Oct 8

The paper deals with the results of X-ray lymphographic and morphological studies of the peripheral lymphatic system in 82 patients with various stages of chronic lower extremity arterial insufficiency. Destructive and sclerotic changes in lymphatic vessels, inguinal lymph nodes, and impairments in lymph flow whose severity was in proportion to the stage of chronic ischemia were detected. The associated immune, barrier-filtration and transport dysfunctions called for their adequate correction. In patients with Stages II and III ischemia, direct controlled endolymphatic therapy promotes the improvement of tissue lymphatic drainage and hemocirculation in the diseased extremity and recovery of immune homeostasis in the region.
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PMID:[The lymphatic system of the lower extremities in patients with obliterating diseases of the terminal portion of the aorta and its branches]. 832 28

Reperfusion injury, precipitated by lack of oxygen, is likely to play a major role in many clinical conditions, including shock, coronary artery occlusion disease, and solid organ transplantation. Certain tissues, such as the intestinal mucosa, may be especially susceptible because of the specific microvascular anatomy. Structural changes include not only swelling of the organelles but also the entire cell due to the entry of water and electrolytes. Lysosomal ruptures precede cell death. Other key substances which either participate in or are part of oxygen free radical formation in tissue injury are calcium ions, leukocytes, and bacteria. Leukocyte adhesion has been implicated as a critical step in vascular endothelium injury, leading to increased microvascular permeability and thrombosis. Induction of neutropenia or the administration of antileukocyte adhesion monoclonal antibodies, preventing typical injuries, implies a central role of the white blood cells in reperfusion injury. Specifically, oxygen free radical formation in the intestines may trigger or cause injury in other distant organs, e.g., the heart and lungs, and affect overall vascular function. So-called "bacterial translocation" from the intestines to the lymphatic vessels and the bloodstream is a more recently discovered phenomenon whose role is largely unknown. Ischemic preconditioning is still another concept, mainly tested in the canine heart, that has potential clinical applications. Reperfusion of ischemic tissue occurs with solid organ transplantation, often after considerable cold ischemia time. Protective mechanisms include oxygen free radical scavengers, i.e., allopurinol and superoxide dismutase. Other measures proven to be effective during the implantation are blood volume expansion with colloid solutions and/or electrolyte solutions, and the administration of a calcium antagonist. The mechanisms of these measures are likely related to improved renal microcirculation and relief of vasospasm.
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PMID:Reperfusion injury. 877 98

The development of the vascular tree during embryogenesis involves vasculogenesis, angiogenesis and tissue-specific differentiation of endothelium which gives rise to many different vessel types. These processes are physiologically complex and are therefore difficult to study in vitro. However, the discovery of endothelial cell-specific receptors and cognate ligands has led to the generation of transgenic and knockout mouse models which have shed light on the molecular mechanisms that regulate the development of blood and lymphatic vessels during embryogenesis. Such mouse models have demonstrated that members of the vascular endothelial growth factor (VEGF) family of proteins and the VEGF receptors are critical regulators of vasculogenesis, angiogenesis and endothelial cell differentiation. The availability of purified VEGF family members and of inhibitors of these growth factors may provide a means to modulate blood vessel growth for the treatment of cancer, retinopathies and diseases of ischemia.
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PMID:The vascular endothelial growth factor family; proteins which guide the development of the vasculature. 1019 9

Critical leg ischemia is associated with a high risk of amputation when revascularization is not possible. Cell therapy based on bone marrow-derived mononuclear cells or with peripheral mononuclear cells, collected after stimulation with G-CSF has been used in an attempt to stimulate angiogenesis. Although several studies have raised the hope that such cell therapy may be effective in critical leg ischemia, no direct demonstration of angiogenesis induced by bone marrow-derived mononuclear cell/peripheral mononuclear cell injection has been reported in man. The aim of this study was to identify and to evaluate the extent of the angiogenic process associated with cell therapy in critical leg ischemia in man. To address this question, this pathological study was conducted in patients enrolled in the OPTIPEC clinical trial (Optimization of Progenitor Endothelial Cells in the Treatment of Critical leg ischemia), an interventional cell therapy study in critical leg ischemia. Amputation specimens from these patients were submitted to a standardized dissection protocol. In three patients, an active angiogenesis was observed in the distal part of the ischemic limb but not in the gastrocnemius muscle, the site of bone marrow cell injection. All the newly formed vessels were positive for endothelial cell markers (CD31, CD34, von Willebrand factor) and negative for markers of lymphatic vessels (podoplanin). Immunohistochemical staining for Ki-67 and c-kit showed extensive endothelial cell proliferation within the new vessels. Bone marrow-derived mononuclear cell therapy in patients with critical leg ischemia induces an active, substained angiogenesis in the ischemic and distal parts of the treated limb, although this may not prevent amputation in some patients with very severe ischemia.
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PMID:Bone marrow-derived mononuclear cell therapy induces distal angiogenesis after local injection in critical leg ischemia. 1848 98

Peripheral arterial disease (PAD) results from narrowing of the peripheral arteries that supply oxygenated blood and nutrients to the legs and feet, This pathology causes symptoms such as intermittent claudication (pain with walking), painful ischemic ulcerations, or even limb-threatening gangrene. It is generally believed that the vascular endothelium, a monolayer of endothelial cells that invests the luminal surface of all blood and lymphatic vessels, plays a dominant role in vascular homeostasis and vascular regeneration. As a result, stem cell-based regeneration of the endothelium may be a promising approach for treating PAD. In this video, we demonstrate the transplantation of embryonic stem cell (ESC)-derived endothelial cells for treatment of unilateral hindimb ischemia as a model of PAD, followed by non-invasive tracking of cell homing and survival by bioluminescence imaging. The specific materials and procedures for cell delivery and imaging will be described. This protocol follows another publication in describing the induction of hindlimb ischemia by Niiyama et al.
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PMID:Embryonic stem cell-derived endothelial cells for treatment of hindlimb ischemia. 1922 80

Envenomations by Bothrops asper are often associated with complex and severe local pathological manifestations, including edema, blistering, dermonecrosis, myonecrosis and hemorrhage. The pathogenesis of these alterations has been investigated at the experimental level. These effects are mostly the consequence of the direct action of zinc-dependent metalloproteinases (SVMPs) and myotoxic phospholipases A(2) (PLA(2)s). SVMPs induce hemorrhage, blistering, dermonecrosis and general extracellular matrix degradation, whereas PLA(2)s induce myonecrosis and also affect lymphatic vessels. In addition, the prominent vascular alterations leading to hemorrhage and edema may contribute to ischemia and further tissue necrosis. The mechanisms of action of SVMPs and PLA(2)s are discussed in detail in this review. Venom-induced tissue damage plays also a role in promoting bacterial infection. A prominent inflammatory reaction develops as a consequence of these local pathological alterations, with the synthesis and release of abundant mediators, resulting in edema and pain. However, whether inflammatory cells and mediators contribute to further tissue damage is not clear at present. Muscle tissue regeneration after venom-induced pathological effects is often impaired, thus resulting in permanent tissue loss and dysfunction. SVMP-induced microvessel damage is likely to be responsible of this poor regenerative outcome. Antivenoms are only partially effective in the neutralization of B. asper-induced local effects, and the search for novel toxin inhibitors represents a potential avenue for improving the treatment of this serious aspect of snakebite envenomation.
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PMID:Experimental pathology of local tissue damage induced by Bothrops asper snake venom. 1930 33

Sprouty proteins (Sproutys) inhibit receptor tyrosine kinase signaling and control various aspects of branching morphogenesis. In this study, we examined the physiological function of Sproutys in angiogenesis, using gene targeting and short-hairpin RNA (shRNA) knockdown strategies. Sprouty2 and Sprouty4 double knockout (KO) (DKO) mice were embryonic-lethal around E12.5 due to cardiovascular defects. The number of peripheral blood vessels, but not that of lymphatic vessels, was increased in Sprouty4 KO mice compared with wild-type (WT) mice. Sprouty4 KO mice were more resistant to hind limb ischemia and soft tissue ischemia than WT mice were, because Sprouty4 deficiency causes accelerated neovascularization. Moreover, suppression of Sprouty2 and Sprouty4 expression in vivo by shRNA targeting accelerated angiogenesis and has a therapeutic effect in a mouse model of hind limb ischemia. These data suggest that Sproutys are physiologically important negative regulators of angiogenesis in vivo and novel therapeutic targets for treating peripheral ischemic diseases.
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PMID:Suppression of Sproutys has a therapeutic effect for a mouse model of ischemia by enhancing angiogenesis. 1942 91

Organ damage and innate immunity during heart transplantation may evoke adaptive immunity with serious consequences. Because lymphatic vessels bridge innate and adaptive immunity, they are critical in immune surveillance; however, their role in ischemia-reperfusion injury (IRI) in allotransplantation remains unknown. We investigated whether the lymphangiogenic VEGF-C/VEGFR3 pathway during cardiac allograft IRI regulates organ damage and subsequent interplay between innate and adaptive immunity. We found that cardiac allograft IRI, within hours, increased graft VEGF-C expression and lymphatic vessel activation in the form of increased lymphatic VEGFR3 and adhesion protein expression. Pharmacological VEGF-C/VEGFR3 stimulation resulted in early lymphatic activation and later increase in allograft inflammation. In contrast, pharmacological VEGF-C/VEGFR3 inhibition during cardiac allograft IRI decreased early lymphatic vessel activation with subsequent dampening of acute and chronic rejection. Genetic deletion of VEGFR3 specifically in the lymphatics of the transplanted heart recapitulated the survival effect achieved by pharmacological VEGF-C/VEGFR3 inhibition. Our results suggest that tissue damage rapidly changes lymphatic vessel phenotype, which, in turn, may shape the interplay of innate and adaptive immunity. Importantly, VEGF-C/VEGFR3 inhibition during solid organ transplant IRI could be used as lymphatic-targeted immunomodulatory therapy to prevent acute and chronic rejection.
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PMID:Ischemia-Reperfusion Injury Enhances Lymphatic Endothelial VEGFR3 and Rejection in Cardiac Allografts. 2668 83


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