Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Thrombus formation depends on adherence of blood-formed elements to the intimal surface through platelet-vessel surface interaction, platelet release phenomena and aggregation, formation of fibrin, and the enmeshing of blood cells. Arterial thrombi involve platelet aggregation, whereas venous thrombi found in low flow or during stasis have greater proportions of erythrocytes and fibrin. It is not known if or how abnormalities of flow resistance, platelet thrombus formation, or endothelial and dynamic parameters affect the microcirculation, largely due to the difficulty of obtaining comprehensive data from these systems. Increases of fibrinogen observed in many disorders may result in minor changes in blood viscosity without known physiologic consequence, but in most disorders in which thrombosis is observed, the pathophysiologic mechanisms are multifactorial and abnormal blood viscosity is presumed to be a significant but not limiting component. Therapeutic approaches in thrombotic disorders should recognize which elements of the thrombotic triad predominate. In arterial disorders focus should be on platelet activity, and the objectives of venous thrombosis treatment include prevention of morbidity and death from pulmonary embolism, reduction of morbidity resulting from the acute thrombotic episode, and prevention of the postphlebitic syndrome. Pathology, mechanism, and treatment for specific thrombogenic disorders are described. Treatments suggested for hyperviscosity involve giving antibiotics during crises. Also discussed are thalassemia, paroxysomal nocturnal hemoglobinuria, polycythemia, cryoglobulinemia, paraproteinemia, diabetes mellitus, and disseminated intravascular coagulation. Studies have established a relationship between thromboembolic disease and oral contraceptives (OCs). The risk is only increased while the patient is taking OCs but is compounded in women undergoing surgery or who have a disorder which predisposes to venous disease. The risk for myocardial infarction or stroke is significantly increased when OCs are taken over age 35 and when there is hypertension, smoking, type-II hyperlipoproteinemia, and diabetes mellitus. The risk appears to be a function of estrogen dosage, causing a 25% mean increase in calf venous volume and 30% decrease in vein velocity of venous blood compared to controls. Low flow rates may contribute to venous thromboembolism. OCs may alter precisely regulated systems of coagulation and fibrinolysis and recent studies confirm abnormalities in the hemostatic system attributed to OCs. 16% of women taking OCs have a 60% or greater reduction in antithrombin III activity. The multiple effects of OCs often result in low-grade activation of the hemostatic system, potentially lowering the threshold to precipitate thrombus formation and possibly explaining the increased incidence of thromboembolic disease. Heparin appears to reverse many of these problems.
 ...
PMID:Blood viscosity and thrombosis: clinical considerations. 676 12

The in vitro measurement of whole-blood viscosity, plasma viscosity, and erythrocyte aggregability is easy to perform, but they only allow a partial insight into the complexity of blood flow characteristics; however, they permit definition of the rheological properties of new hemorheological therapeutic modalities such as extracorporeal plasma therapy as described in this paper. Under more theoretical aspects, it becomes obvious that such hemorheological approaches should either improve the vasomotoric properties of blood vessels, reduce the circulating red blood cell concentration, or improve the viscosity by reducing the concentration of hemorheologically relevant plasma proteins. In this review, the rheological effect of a single apheresis treatment with different devices was compared. Due to their differences in selectivity, the extracorporeal methods have different effects on the rheologically relevant plasma proteins, and, therefore, their rheological effectiveness differs remarkably. Today, the classical blood letting and plasma exchange treatment have been replaced by erythrapheresis and selective devices for extracorporeal plasma treatment, respectively. For more than 10 years, the following 5 more-or-less selective apheresis procedures are commercially available: immunoadsorption, differential filtration, polyanion adsorption by dextrane sulfate as well as by polyacrylate, and polyanion precipitation by heparin as polyanion. The last three procedures are semiselective and, therefore, relatively unspecific whereas immunoadsorption only affects the plasma lipoprotein concentration. Several studies have shown the effective use of extracorporeal hemorheotherapy for the treatment of various diseases including macro- and cryoglobulinemia, Raynaud's disease, hyperlipoproteinemia (often characterized by premature atherosclerosis and coronary heart disease and peripheral arterial occlusive disease), cerebral multi-infarct demention and acute ischemic stroke, sudden hearing loss, and acute occlusion of the central retinal artery.
 ...
PMID:Selective hemapheresis, an effective new approach in the therapeutic management of disorders associated with rheological impairment: mode of action and possible clinical indications. 1187 39

Central nervous system involvement in patients with hepatitis C infection have been rarely reported. Stroke and encephalopathic syndromes have been frequently attributed to the ischemia or hemorrhage associated with mixed cryoglobulinemia and anticardiolipin antibodies. We describe the case of a 31-year-old woman with cerebral ischemia who had hepatitis C infection confirmed by polymerase change reaction detection of HCV RNA but who was negative for cryoglobulinemia. Cerebral involvement may be the initial manifestation of hepatitis C infection.
 ...
PMID:[Central nervous system involvement in patients with hepatitis C infection]. 1269 Jul 40

Moya Moya disease is a rare cause of stroke in adults, and is a rarity secondary to hepatitis C virus infection (HCV) and cryoglobulinemia (CG). We report such a rare association in a young patient who presented with intracerebral hemorrhage.
 ...
PMID:Moya Moya disease : an unusual clinical presentation. 1585 14

Autoimmune processes take place during an acute phase of brain injury as well as during chronic vascular diseases. Cryoglobulinemia is a nonspecific marker of long-term stimulation of the immune system which reflects duration of autoimmune sensitization. It is characterized by production of abnormal temperature-dependent immunoglobulins named cryoglobulins. The highest cryoglobulinemia was found in patients with atherothrombotic stroke that corresponds to the results of previous studies reporting the greatest level of neurospecific antibodies during slow atherothrombosis development. It is shown that cryoglobulinemia is an important factor in pathogenesis of stroke which contributes to microcirculatory and hemorheological disorders, increases blood viscosity and results in the development of immunocomplex endovasculitis of small brain blood vessels in the ischemic lesion.
 ...
PMID:[Involvement of autoimmune mechanisms in development of ischemic brain damage]. 1618 Apr 98

Hepatitis virus C (HCV) is worldwide a health problem, which may lead to serious complications. The aim of this study was to correlate the onset of the cerebral ischemic attack accompanied by mixed cryoglobulinemia, with the chronic hepatitis C virus infection. These studies were carried out in 12 patients with serologic/virusologic confirmed chronic HCV infection associated with ischemic stroke. Ischemic stroke occurred in equal proportion in women and men. The patients did not know of HCV infection diagnosis at that moment. All patients had type II mixed monoclonal cryoglobulinemia, hypergammaglobulinemia with polyclonal IgG and monoclonal IgM, blood hyperviscosity, high level of cryocrit, positive rheumatoid factor, normal levels of serum transaminases, negative serum hepatitis B surface antigen (HBs Ag), negative anti HBc antibodies, positive HCV antibodies, positive serum RNA HCV, decreased serum C3 and C4 levels, antinuclear antibodies-false positive. Immunological tests for autoantibodies, namely, anti-Sm antibody, anti-RNP antibody, anti-SS-A and -B antibodies, and anti-Scl antibody were not detectable due to high level serum cryoglobulin. Cryoglobulin was washed several times with an isotonic chloride solution for purification, then subject to immunological analyses. The purified cryoglobulin contained monoclonal IgM-kappa, polyclonal IgG. Cryoglobulinemia is a risk factor for ischemic stroke, as it causes arterial thrombosis.
 ...
PMID:Cerebral ischemic attack secondary to hepatitis C virus infection. 1681 84

The clinical course of cryoglobulinemic syndrome (CS) is usually slow; however, fast aggravations have been frequently reported in recent years. In these cases vasculitic ischemic tissue damage accounts for glomerular involvement, neuropathy, cutaneous ulcers, ischemic heart disease, lung or jejunal impairment and stroke. Other critical events in CS may be represented by sepsis, liver insufficiency, hepatocellular carcinoma and non-Hodgkin's lymphomas. Sometimes emergency can not be controlled and the evolution is fatal. Long-term follow up, emergency outcome and cause of death have not been considered in controlled studies, in large series. Here we report a 53-year old woman affected by IgG-IgMk type II HCV-related mixed cryoglobulinemia, who presented several critical events over the course of the disease, which required therapeutical emergency interventions. The latter consisted of plasma exchange, cytotoxic agents, corticosteroids, intravenous immunoglobulin, antihypertensive drugs, antibiotics, and rituximab. Eventually no therapy was effective and the patient died from a catastrophic-like syndrome. This case is relevant because it enables us to consider some important steps in the treatment of emergency in CS.
 ...
PMID:Emergency in cryoglobulinemic syndrome: what to do? 1793 11

Cerebral venous thrombosis (CVT) is infrequent among cerebrovascular diseases. The simultaneous thrombosis involving both cerebral artery and venous sinus is even extremely rare. We reported a 41-year-old woman who presented with acute headache and left hemiparesis due to concomitant arterial ischemic stroke and recurrent CVT. Extensive investigation disclosed acquired protein C and protein S deficiency, iron deficiency anemia (IDA) and cryoglobulinemia. She was treated with intravenous injection of heparin followed by oral anticoagulant therapy. The headache rapidly subsided; however, left hemiparesis persisted over five months. The rare condition of simultaneous thrombosis of cerebral artery and venous sinus may be caused by the synergistic effect of coagulation disorders, IDA and cryoglobulinemia.
 ...
PMID:Simultaneous thrombosis of cerebral artery and venous sinus. 1868 52

Hepatitis C virus (HCV) infection represents a major health issue worldwide due to its burden of chronic liver disease and extrahepatic manifestations including cardiovascular diseases, which are associated with excess mortality. Analysis of published studies supports the view that HCV infection should be considered a risk factor for the development of carotid atherosclerosis, heart failure and stroke. In contrast, findings from studies addressing coronary artery disease and HCV have yielded conflicting results. Therefore, meta-analytic reviews and prospective studies are warranted. The pathogenic mechanisms connecting HCV infection, chronic liver disease, and atherogenesis are not completely understood. However, it has been hypothesized that HCV may promote atherogenesis and its complications through several direct and indirect biological mechanisms involving HCV colonization and replication within arterial walls, liver steatosis and fibrosis, enhanced and imbalanced secretion of inflammatory cytokines, oxidative stress, endotoxemia, mixed cryoglobulinemia, perturbed cellular and humoral immunity, hyperhomocysteinemia, hypo-adiponectinaemia, insulin resistance, type 2 diabetes and other components of the metabolic syndrome. Understanding these complex mechanisms is of fundamental importance for the development of novel therapeutic approaches to prevent and to treat vascular complications in patients with chronic HCV infection. Currently, it seems that HCV clearance by interferon and ribavirin treatment significantly reduces non-liver-related mortality; moreover, interferon-based treatment appears to decrease the risk of ischemic stroke.
...
PMID:Chronic hepatitis C virus infection and atherosclerosis: clinical impact and mechanisms. 2470 24

Hepatitis C virus (HCV) infection is considered a systemic disease because of involvement of other organs and tissues concomitantly with liver disease. Among the extrahepatic manifestations, neuropsychiatric disorders have been reported in up to 50% of chronic HCV infected patients. Both the central and peripheral nervous system may be involved with a wide variety of clinical manifestations. Main HCV-associated neurological conditions include cerebrovascular events, encephalopathy, myelitis, encephalomyelitis, and cognitive impairment, whereas "brain fog", depression, anxiety, and fatigue are at the top of the list of psychiatric disorders. Moreover, HCV infection is known to cause both motor and sensory peripheral neuropathy in the context of mixed cryoglobulinemia, and has also been recently recognized as an independent risk factor for stroke. These extrahepatic manifestations are independent of severity of the underlying chronic liver disease and hepatic encephalopathy. The brain is a suitable site for HCV replication, where the virus may directly exert neurotoxicity; other mechanisms proposed to explain the pathogenesis of neuropsychiatric disorders in chronic HCV infection include derangement of metabolic pathways of infected cells, alterations in neurotransmitter circuits, autoimmune disorders, and cerebral or systemic inflammation. A pathogenic role for HCV is also suggested by improvement of neurological and psychiatric symptoms in patients achieving a sustained virologic response following interferon treatment; however, further ad hoc trials are needed to fully assess the impact of HCV infection and specific antiviral treatments on associated neuropsychiatric disorders.
...
PMID:Chronic hepatitis C virus infection and neurological and psychiatric disorders: an overview. 2574 Nov 33


1 2 Next >>