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Endocrine, Metabolic & Immune Disorders... Jun 2006Sepsis is the result from a complex bacterial-host interaction, which is an often-fatal response when host protective molecular mechanisms designed to fight invading...
Sepsis is the result from a complex bacterial-host interaction, which is an often-fatal response when host protective molecular mechanisms designed to fight invading bacteria surpass the beneficial intensity to the point of causing injury to the host. Increasing evidences have implicated the bacterial translocation (BT) as the main source for the induction of sepsis, although the beneficial effect of BT process has been related to the development of the intestinal immune response by physiological interaction between bacteria and host. In this article, we examined evolving concepts concerning to BT and discussed about its potential role in the promotion of microcirculation injury, moreover, its possible participation in the sepsis induction. According to our data obtained from in-vivo BT animal-model, both bacterial overgrowth and bacterial pathogenic determinants seem to be major predisposing factors for the induction of BT. Besides, translocation of luminal bacteria through the lymphatic via elicits the activation of the GALT inflammatory response contributing to microcirculation injuries, and the haematological via of BT was responsible to the systemic bacterial spread. On other hand, the combination of BT process to the pre-existing host systemic infection played a crucial role in the worsening of the clinical outcome. In our understanding, studies concerning to intestinal immune response and the pathophysiology of bacterial-host interaction, under normal and disease conditions, seems to be the key elements to the development of therapeutic approaches towards sepsis.
Topics: Animals; Bacterial Translocation; Humans; Intestines; Microcirculation; Sepsis
PubMed: 16787288
DOI: 10.2174/187153006777442323 -
Giornale Italiano Di Cardiologia May 1994
Review
Topics: Blood Pressure; Coronary Circulation; Coronary Disease; Humans; Methods; Microcirculation; Vascular Resistance
PubMed: 8076733
DOI: No ID Found -
Journal of Cerebral Blood Flow and... Aug 2003Cerebral microvessels have a unique ultrastructure form, which allows for the close relationship of the endothelium and blood elements to the neurons they serve, via... (Review)
Review
Cerebral microvessels have a unique ultrastructure form, which allows for the close relationship of the endothelium and blood elements to the neurons they serve, via intervening astrocytes. To focal ischemia, the cerebral microvasculature rapidly displays multiple dynamic responses. Immediate events include breakdown of the primary endothelial cell permeability barrier, with transudation of plasma, expression of endothelial cell-leukocyte adhesion receptors, loss of endothelial cell and astrocyte integrin receptors, loss of their matrix ligands, expression of members of several matrix-degrading protease families, and the appearance of receptors associated with angiogenesis and neovascularization. These events occur pari passu with neuron injury. Alterations in the microvessel matrix after the onset of ischemia also suggest links to changes in nonvascular cell viability. Microvascular obstruction within the ischemic territory occurs after occlusion and reperfusion of the feeding arteries ("focal no-reflow" phenomenon). This can result from extrinsic compression and intravascular events, including leukocyte(-platelet) adhesion, platelet-fibrin interactions, and activation of coagulation. All of these events occur in microvessels heterogeneously distributed within the ischemic core. The panorama of acute microvessel responses to focal cerebral ischemia provide opportunities to understand interrelationships between neurons and their microvascular supply and changes that underlie a number of central nervous system neurodegenerative disorders.
Topics: Brain Ischemia; Cerebrovascular Circulation; Endothelium, Vascular; Humans; Microcirculation
PubMed: 12902832
DOI: 10.1097/01.WCB.0000078322.96027.78 -
Current Medical Research and Opinion 2005The importance of abnormalities observed in the microcirculation of hypertensive subjects is being increasingly recognised. These microvascular changes may be central to...
The importance of abnormalities observed in the microcirculation of hypertensive subjects is being increasingly recognised. These microvascular changes may be central to the development of end-organ damage brought about by hypertension, including ischaemic heart disease. The primary function of the microcirculation is to supply oxygen and nutrients to myocardial tissue, and it also has an important role in regulating coronary blood flow. Some 70-90% of the overall peripheral resistance of the circulatory system arises at the level of the microcirculation. In hypertension, thickening of the microvascular walls occur, with narrowing of the lumen, so that eventually the vessel is functionally occluded. The result is a reduction in the number of arterioles or capillaries in a given vascular bed. Such changes have been seen in the structure and density of the microvasculature of heart muscle, the conjunctiva and retina, and in the kidneys. In hypertension a vicious circle occurs, with an increase in blood pressure producing a rise in resistance in the microcirculation, leading to further elevation of blood pressure. New techniques for exploring the coronary microcirculation have shown that microvascular damage results in reductions of coronary vasodilator reserve, an important predictor of clinical deterioration and death. With studies showing that impairment of microcirculation occurs early in patients with hypertension, there would seem to be a need for new therapeutic perspectives in hypertension, concentrating on preventing or reversing changes to the microvasculature of affected organs.
Topics: Blood Flow Velocity; Constriction, Pathologic; Coronary Circulation; Endothelium, Vascular; France; Humans; Hypertension; Microcirculation; Regional Blood Flow; Vascular Resistance
PubMed: 16197644
DOI: 10.1185/030079905X56411 -
International Journal of Radiation... 1991
Topics: Animals; Brain Neoplasms; Disease Models, Animal; Glioma; Microcirculation; Rats
PubMed: 1677961
DOI: 10.1080/09553009114551711 -
Tanpakushitsu Kakusan Koso. Protein,... May 1997
Review
Topics: Animals; Blood Flow Velocity; Erythrocytes; Humans; Microcirculation; Microscopy; Microscopy, Video
PubMed: 9170932
DOI: No ID Found -
Medical Informatics = Medecine Et... 1979An analytical expression for the relationship between velocity (and blood flow) and diameter for vessels in the microcirculatory range up to 900 mum diameter is...
An analytical expression for the relationship between velocity (and blood flow) and diameter for vessels in the microcirculatory range up to 900 mum diameter is presented. Both the arterial and venous systems are considered. The analytical expression for these relationships has been derived from computer analysis of data obtained from individual measurements reported in the literature. Computer analysis shows that blood velocity is a nearly linear function of diameter of blood vessels for the arteriolar tree. The relationship for blood flow as a function of diameter is Q = 108d3.101 for arteries, arterioles and capillaries in the diameter range 5 to 900 mum and for the venous system in the range 5 to 115 mum is Q = 334d2.388 where Q is in mum3 per second and d is in mum. Comparison of the results of this study for the arterial system to the Hagen-Poiseuille Law reveals close agreement, if correction is made for geometric factors of blood vessels and for the variation of viscosity with diameter for blood.
Topics: Animals; Blood Flow Velocity; Blood Vessels; Computers; Humans; Mathematics; Microcirculation; Regression Analysis
PubMed: 542047
DOI: 10.3109/14639237909017762 -
Seminars in Thrombosis and Hemostasis Jul 1986
Review
Topics: Animals; Blood Coagulation; Capillary Permeability; Complement Activation; Endothelium; Fibrin; In Vitro Techniques; Lung; Lung Injury; Microcirculation; Neutrophils; Oxygen; Pulmonary Circulation; Thrombin
PubMed: 3535076
DOI: 10.1055/s-2007-1003549 -
Proceedings of the Chinese Academy of... 1987
Topics: Microcirculation; Models, Cardiovascular
PubMed: 3451286
DOI: No ID Found -
Anesthesiology Oct 1971
Topics: Anesthetics; Animals; Chiroptera; Humans; Microcirculation; Regional Blood Flow; Vasomotor System
PubMed: 5114394
DOI: No ID Found