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Results for “ERYTHROCYTE AGGREGATION, INTRAVASCULAR”

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At least 181 records · Page 10Linked to original sources
PubMed2003

[Clinical implications of impaired microcirculation and hemodynamics in acute respiratory viral infections and their pharmacological correction].

Microcirculation, hemocoagulation and blood viscosity were studied in 377 of 1033 inpatients with influenza and other acute respiratory viral infections. The new data show that it is feasible to improve the course, outcomes and results of the treatment. Microcirculation disorders persist throughout the disease, but in convalescence, intravascular alterations are leading. The microcirculatory changes manifest themselves with advanced erythrocyte aggregation, activation of vascular-platelet and plasmic links of hemostasis, and high blood viscosity at low shift velocities. In the presence of concomitant pathology (ischemic heart disease, hypertensive disease, diabetes mellitus) and development of complications, especially acute pneumonia, these disturbances are still greater and tend to increase to the period of decline of clinical and toxic manifestations. These patients should take acetylsalicylic acid (aspirin) as an antiaggregant and other medicines improving blood rheology.

Acute Disease↗
PubMed1981

[Erythrocyte interaction during aggregation according to scanning electron microscope findings].

Scanning electron microscopy was used to study red cell aggregation caused by intravascular injection of dextran (m. w. 500 000). Two types of aggregates were revealed. Type 1 was represented by aggregates of red cells with no substantial change in the form while type 2 by aggregates with the wrinkling of the surface of red cells and enlarged area of red cell surface contacts. Both types are prone to disaggregation after injection of rheopolyglucin.

Animals↗
PubMed1986

[Microcirculatory disorders in the genesis of sclerodermic nephropathy].

Biomicroscopy of the vessels of the conjunctiva (BMV), the determination of erythrocyte and platelet aggregation capacity and investigations of the effective cutaneous and muscular blood flow and blood plasma renin activity were employed to study microcirculation in 110 patients with systemic sclerodermia (SSD) (74 with and 36 without renal lesion). The detected disturbances were correlated with the nature and gravity of sclerodermic nephropathy (SN). In BMV the frequency of intravascular platelet aggregation increased with a rise of the gravity of renal pathology. The quantitative determination of erythrocyte and platelet aggregation capacity revealed a significant acceleration of the aggregation of the blood cell elements in the SSD patients which correlated with SN presence and gravity as well as with renal function indices. Renin plasma activity was significantly raised in patients with severe renal pathology. There was correlation between the indices of function of the kidneys and ultrastructural signs of lesion of their microcirculatory bed. The results of the study served as a basis for the differential use of vascular drugs and the development of new pharmacotherapeutic methods for SSD patients with renal lesion.

Adolescent↗
PubMed2005

[Treatment of freezing injury].

Report on therapeutic procedures in patients with second and third degree congelations (frostbite) on the feet. Two mechanisms of tissue damage caused by exposure to cold temperature will be discussed pathophysiologically: direct freezing injuries and cell death through intra and extracellular ice crystal formation as well as transient and finally irreversible tissue damage due to decreased perfusion. The condition of decreased perfusion results from persistent vaso-constriction induced by cold temperature, increased blood viscosity, sludge phenomenon and occlusion by platelet thrombi in the microvasculature. Frostbite beyond the erythematous stage should be treated primarily with a parenteral therapy in order to improve the hemorrheologic parameters, in particular within the micro-vascular compartment. Colloidal plasma volume expander such as 10% dextran solution is used to increase the intravascular volume. This solution (with its coating effect) and pentoxifyllin lowers the aggregation of erythrocytes and platelets. The latter will also be favourably influenced by the use of iloprost or acetylsalicylic acid. Iloprost as a stable metabolite of prostacyclin is a powerful vasodilator which attenuates the peripheral vascular resistance and activates fribrinolysis. Pentoxifyllin is considered to lower pathologically increased levels of fibrinogen. Both drugs may protect against damage of the vascular endothelium. Based on their pharmacological effects the above-mentioned drugs may improve tissue perfusion and therefore tissue damage caused by frostbite can be limited. However, an important factor is to strictly avoid bacterial infections in the cold-damaged tissue.

Blood Viscosity↗
PubMed1994

Analysis of ultrasonic scattering in blood via a continuum approach.

Since the pioneering work by Reid et al. on measuring ultrasonic scattering in blood, this phenomenon has been extensively studied both theoretically and experimentally. The knowledge on ultrasonic scattering properties of blood is needed for the design of ultrasonic methods for measuring blood flow, and a better interpretation of ultrasonic images. The development of high frequency intravascular or intracardiac imaging devices raises the possibility of measuring blood properties, e.g., erythrocyte aggregation and fibrinogen concentration, in situ. A number of theoretical approaches have been developed to analyze this phenomenon where in general ultrasound wavelength is much greater than the erythrocytes. These results show that the backscattering coefficient of blood, defined as power backscattered by a unit volume of blood per steradian per unit incident intensity, is proportional to variance of the erythrocyte number fluctuation and backscattering cross-section of a single erythrocyte. In this paper, we will show that similar results can also be obtained by taking a continuum approach.

Blood↗
PubMed1975

Metastatic hemangiopericytoma associated with microangiopathic hemolytic anemia: review and report of a case.

The hemangiopericytoma is an invasive tumor of vascular origin. No matter how benign the course and how circumscribed the mass, it must be considered a lesion with high malignant potential. In the case report here, a hemangiopericytoma of the pancreas with metastasis to the liver was associated with microangiopathic hemolytic anemia in a 78-year old woman. The anemia may have been present before the onset of metastasis. If so, it could have been a major factor in the breakdown of host response and could have initiated the malignant dissemination. Under these circumstances it could be an indicator of metastasis in patients with previously diagnosed tumors. However, there are many cases of metastatic malignancy associated with this anemia in which the opposite situation holds. The anemia is usually of extracorpuscular origin. Apparently intravascular coagula1ion caused by injury from tumor-cell aggregates in small vessels induces erythrocyte fragmentation in fibrin strands. A vicious cycle of cell fragmentation, vascular injury and fibrin strand formation completes the course. Analysis of the findings should be based upon more than a strictly pathologic approach; it should also be related to the new discoveries in cancer research.

Aged↗
PubMed1983

Laser-induced thrombi in rat mesenteric vessels and antithrombotic drugs.

A method to induce microthrombi in small mesenteric arteries (phi 15-25 microns) has been developed to study platelet reactions and to investigate antithrombotic drugs. A high power water immersion interference contrast system, based on a Leitz Orthoplan microscope, was used. In Nembutal-anesthetized male Wistar rats and in fawn hooded bleeder rats, vascular lesions were produced with a Hadron-512-Ruby-bio-laser or with a Coherent CR-2 supergraphite ion laser (Argon laser). The ruby laser produced intravascular precipitates consisting of proteins and erythrocytes which usually stuck to the vessel wall and on which platelets immediately adhered, transformed with pseudopode formation and formed loose aggregates. The Argon laser induced vascular damage, usually without intravascular heat precipitates which also led to platelet adhesion, transformation and aggregation. Fibrin threads rarely formed in the early platelet thrombi. Thrombus formation was significantly reduced in this model by dipyridamole (10 mg/kg orally), by Ditazole (50 mg/kg orally), heparin (100 IU/kg i.v.), Molsidomine (50 mg/kg orally), Nafazatrom (Bay G 6575, 10 mg/kg i.v. and orally), Ticlopidine (100 and 200 mg/kg orally) and Tioxaprofen (EMD 26644, 10 mg/kg orally). Thrombus formation was also significantly reduced in fawn hooded bleeder rats.

Animals↗
PubMed2002

Major alterations in body fluid status and blood rheology.

Since the dehydration causes a loss of body water, we studied the rheological properties of blood in the course of water deprivation. Subjects used in this study were 64 white male rats divided into 4 groups: control (n=19) and 3 experimental groups which underwent water deprivation for 3 days (n=15), 6 days (n=15) and 10 days (n=15). The results obtained indicate that under dehydration animals have higher blood and plasma viscosity and erythrocyte aggregation index than in the control group. After 3 days of dehydration these changes are due to the loss of intravascular water. The water deprivation for 10 days causes significant disturbances in blood composition as well as changes of red blood cell membrane properties whereas blood and plasma volume return to control values.

Animals↗