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Results for “Microcirculation”

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PubMedDate not supplied

[The planning of local plastic operations after the radiation therapy of malignant tumors of the head taking into account the blood microcirculation of the skin].

The microcirculation changes were detected in tissues within and beyond the irradiated area. The changes were marked to a different degree depending on the ionizing irradiation dose and the time since its termination. The microcirculatory changes were less pronounced in the major cerebral vessels' body. The data suggest that microcirculation could provide an objective test in planning the local plastic surgery in the zones of irradiated skin malignant tumors in maxillofacial and haired regions of the head.

Head and Neck Neoplasms↗

PubMed1989

[Animal experimental studies on the microcirculation of ionic and nonionic x-ray contrast media].

In vivo microscopic (video) investigations on the variability of flow conditions in the myocardium and intestines of anaesthesized normal tension rats after application of various ionic and non-ionic contrast media (Amidotrizoate, Ioxaglate, Iopromide, Iohexol, Iotrolan). Amidotrizoate causes heterogeneous microperfusion and functional shunt vessels (distribution disorder) with the typical symptoms of disturbed microcirculation. Ioxaglate, Iopromide, Iohexol and Iotrolan influence microcirculation differently but always to a far less degree.

Animals↗

PubMed1989

[The microcirculation of the myocardium based on scintigraphic data using labelled microspheres].

The authors described an original procedure for the determination of the organ blood flow with the help of 99mTc-labeled microspheres of aggregated albumin. Some features of the myocardial microcirculation in patients with CHD and without it were determined as well as interrelationships between the major coronary blood flow and the state of the myocardial microcirculation in various groups of CHD patients. A group of 32 males was examined. After thorough clinico-instrumental investigation CHD was diagnosed in 18 of them, 14 persons were taken as controls. Intraventricular administration of labeled microspheres during coronary angiography was followed by multipositional scintigraphy of the myocardium with further computer processing of images. A high sensitivity and specificity of the method was shown. The data obtained were compared with the results of other methods, among them those used by foreign researchers.

Adult↗

PubMed1987

[Effect of bacterial toxins on microcirculation (experimental research)].

Histological and biomicroscopic methods were used to study the effects of toxic lemic and meningococcal microbial fractions on mesenteric blood microcirculation in rats. Aggregation ability of red blood cells and thrombocytes was investigated. The sublethal dose of meningococcal toxins was shown to induce marked impairment in the blood microcirculation 30 minutes after intravenous administration. The lethal dose of lemic toxins manifests itself later (in 2-4 hours). Meningococcal toxins are characterized by the increase in the aggregation ability of erythrocytes and thrombocytes in initial observation periods; lemic toxins increase the thrombocyte aggregation and produce almost no effect on erythrocyte aggregation.

Animals↗

PubMed1988

Calcium dobesilate and its effects on hemorheology and microcirculation.

In series, 50 patients suffering from cerebral (n = 33) and peripheral (n = 17) diseases were treated with 3 x 500 mg calcium dobesilate (Doxium) per day. Before onset of therapy and after 14 days the viscoelasticity of whole blood and plasma as well as hematocrit and microcirculation at the finger pad were measured. Viscoelasticity of whole blood, plasma and hematocrit decreased in a significant manner (p less than or equal to 0.001), while microcirculation increased significantly (p less than or equal to 0.001). The results justify the application of calciumdobesilate for ischemic diseases with elevated viscosity.

Adult↗

PubMed1988

[Pathophysiologic aspects of conservative therapy of post-traumatic cerebrovascular disorders of the microcirculation].

In order to avoid or diminish secondary cerebral damage in the treatment of the craniocerebral trauma the removal of disturbances of the microcirculation is of decisive importance to the course of the disease and the prognosis. The microcirculation is essentially determined by rheological factors such as haematocrit, plasma viscosity, aggregation and fluidity of erythrocytes. Rheological aspects should be included to a greater extent than has been done until now in the basic therapy of traumatic cerebral blood supply disturbances. If this is not done, an important therapeutic reserve is not made use of. In our opinion isovolaemic haemodilution is a practical method. The application of cerebroselective calcium antagonists appears to be reasonable as well.

Brain Concussion↗

PubMedDate not supplied

[Microcirculation and tissue oxygen supply in chronic insufficiency of the adrenal cortex].

A study was made of the state of microcirculation and oxygen balance of tissues in 51 patients with chronic adrenocortical insufficiency with various degrees of severity of disease during decompensation and compensation. Methods of biomicroscopy of the eye conjunctival vessels using a photoslit tube and polarography on the LP-7 apparatus were employed. Considerable disorders of microcirculation and tissue oxygen balance in patients with Addison's disease depending on a degree of severity of disease indicated a great role of the adrenocortical hormones in maintaining homeostatic stability and body vital activity.

Addison Disease↗

PubMed1988

Role of endogenous norepinephrine in microcirculation after experimental acute spinal cord injury.

The effects of endogenous norepinephrine on changes in spinal microcirculation after acute injury of the spinal cord were examined in rabbits. 6-hydroxydopamine (6-OHDA), which selectively destroys catecholamine neurons, was injected into the subarachnoid cavity of the rabbit spinal cord. Measurement of the intraspinal monoamine level revealed a decrease in the intraspinal norepinephrine level in the treated animals. Recovery from motor paralysis after compression at T-8 occurred more rapidly in the treated than in untreated animals. The animals were observed with respect to 1) blood flow in the spinal cord, 2) intraspinal vascular permeability, and 3) edema of the spinal cord. In the untreated animals, vascular permeability increased and edema developed immediately after the injury. In the treated animals, however, both the increase in vascular permeability and the extent of edema were smaller. Our findings indicate that intraspinal norepinephrine plays an important role in the change of microcirculation after acute spinal cord injury.

Animals↗

PubMed1987

[Effects of S-adenosyl-L-methionine on the cerebral energy metabolism and microcirculation in the rats subjected to transient forebrain ischemia].

Effects of S-adenosyl-L-methionine (SAM) on the improvement of cerebral energy metabolism and microcirculation were examined in postischemic rat brain. Male Wistar rats, whose vertebral arteries were electrically cauterized last day, were subjected to forebrain ischemia by temporary clipping of both common carotid arteries. After 60 min of ischemic insult, they were intravenously administered with SAM at doses of 30 or 100 mg/kg; this was followed by recirculation for 60 min. To determine cerebral concentrations of energy metabolites, the brain was frozen in situ. Adenine nucleotides (ATP, ADP, AMP) were assayed by anion-exchange HPLC system, and other metabolites (PCr, glucose, lactate, pyruvate) were analyzed by enzymatic fluorometry. In order to estimate regional cerebral blood flow (rCBF) and glucose utilization, double-tracer autoradiography was undertaken using 14C-iodoantipyrine (14C-IAP) and 18F-fluorodeoxyglucose (18F-FDG). In animals without SAM treatment (60-60 group), energy metabolites did not recover and neither CBF nor glucose uptake restored during 60 min of recirculation. In contrast, in SAM-treated animals (60-60 SAM group), values of the energy metabolites improved significantly and both CBF and glucose uptake recovered, though incompletely. These results indicate that SAM is able to improve postischemic cerebral microcirculation and energy metabolism. For mechanisms of the effects, it is suggested to the enhancement of erythrocyte deformability by phospholipid methylation, the stabilization of mitochondria, and the normalization of injured metabolic reactions. Therefore, we conclude that SAM is able to be effective clinically as a drug treated for the acute phase of cerebrovascular diseases.

Animals↗

PubMed1987

[The use of thermography in the clinical evaluation of microcirculation].

A method of thermography of the hands including the cold test was employed to evaluate peripheral microcirculation in 116 patients (34 with atherosclerosis of the vessels of different sites, 38 with chronic diffuse liver diseases and 38 with chronic pancreatitis). In 29 patients with hepatocirrhosis and chronic pancreatitis microcirculation was also studied by conjunctival biomicroscopy. Microcirculatory disturbances by the method of thermography of the hands, particularly using the cold test, were revealed in a considerable number of cases of primary vascular pathology as well as in chronic liver and pancreatic diseases. Parallelism in the recognition of microcirculatory disturbances by the methods of thermography and conjunctival biomicroscopy was noted. The method of thermography of the hands permitted the evaluation of reactivity of the vessels of the microcirculatory bed. Taking into account its sufficient informative value, noninvasiveness, simplicity and an opportunity of dynamic observations it can be recommended for a wider clinical use to study microcirculatory disturbances.

Adolescent↗

PubMed1987

[Microcirculation, blood coagulation and blood phospholipids in acute pneumonia].

The state of conjunctival microcirculation, thromboelastographic hemocoagulation by 10 indices and 8 fractions of citrated blood plasma phospholipids was studied in 145 patients with acute pneumonia. Microcirculatory disorders with an increase in all conjunctival indices, marked hypercoagulation with raised concentration of phosphatidylethanolamine, lysophosphatidylcholines in parallel with a decrease in the level of phosphatidylcholines of the blood plasma, particularly at the peak of an inflammatory pulmonary process, were found. The relationship of phospholipids with plasma coagulation and microcirculation as a result of the development of a pathological pulmonary process was revealed.

Adolescent↗

PubMed1986

Destruction of rat mammary tumor and normal tissue microcirculation by hematoporphyrin derivative photoradiation observed in vivo in sandwich observation chambers.

The effect of hematoporphyrin derivative photoradiation on tumor and normal tissue microcirculation was studied microscopically in vivo on rats with mammary carcinomas transplanted into subcutis in transparent observation chambers. One day after i.p. injection of hematoporphyrin derivative (15 mg/kg), chambers were exposed to red light (632 +/- 2 nm, eight light dose values, 0 to 270 J/cm2). After an initial blanching (ischemia) of the tumor accompanied by apparent vasoconstriction, reperfusion was observed with a slowing down of the tumor circulation, vasodilatation, and eventually a complete stasis, together with diffuse hemorrhages and subsequent necrosis. Besides, in large normal tissue vessels, platelet aggregates were observed, but no hemorrhage. Tumor regrowth occurred unless the tumor circulation and the adjacent normal tissue circulation were both destroyed. Tumor cell viability after treatment was assessed by transplanting the tumor from the chamber into the flank of the same animal. Even after a combined porphyrin and light dose 4 times the lethal dose for all tissues in the chamber, five of five transplanted tumors did regrow. This leads to the conclusion that, in our model system, tumor cell death after photoradiation occurs secondary to destruction of the microcirculation. In order to obtain additional information on normal tissue damage, rat ears were also irradiated. For the same light dose, the biological effect was only slightly larger than that of the normal tissue in the observation chambers, even though the measured ratio of porphyrin concentrations in ears and normal tissue in the chambers (subcutis) was about six.

Animals↗

PubMed1986

[Blood aggregation and the system of microcirculation in experimental atherosclerosis, its spontaneous regression and hemosorption].

Blood aggregate state and microcirculation were studied during development and spontaneous regression of experimental atherosclerosis and following hemosorption. It has been shown that experimental atherosclerosis is not only accompanied by changes in blood lipid composition, but also by disturbances in the structure and function of microcirculatory bed. Normalization of blood lipid composition and recovery of blood aggregate state and microcirculatory bed structure and function were not observed during spontaneous regression. Repeated hemosorption enhances atherosclerosis regression, normalizes lipid composition of blood and biological membranes and promotes the recovery of microcirculation.

Animals↗

PubMed1986

[Status of tissue microcirculation in psoriatic arthritis].

Microcirculation (the skin and skeletal muscle) was studied using a method of 133Xe clearance from the interstitial depot in 35 patients with psoriatic arthritis. It showed significant microcirculatory disorders expressed in a statistically significant decrease in the effective cutaneous blood flow in unaffected skin zones (mostly in women and in a high inflammatory activity of the process) and in the muscular microcirculation especially noted in the period of reactive hyperemia. The results obtained indicate the presence of generalized involvement of the microcirculatory bed vessels in psoriatic arthritis.

Adult↗

PubMed1987

Mechanism of the therapeutic effect of anisodamine in disseminated intravascular coagulation: study of platelet adhesion and aggregation, malondialdehyde, thromboxane B2, 6-keto-prostaglandin F1 alpha, and microcirculation.

Acute disseminated intravascular coagulation (DIC) is a life-threatening condition that may be encountered in many situations, especially in cases of shock with uncontrollable hemorrhage. Anisodamine, an alkaloid extracted from a Chinese herb, is well known for its dramatic therapeutic effect on DIC. Sixty male rabbits were used to establish an acute DIC model. A total of 240 blood samples were taken for laboratory assays of changes in blood coagulation factors, platelet count, platelet adhesion, platelet aggregation, malondialdehyde (MDA), thromboxane B2 (TXB2), and 6-keto-prostaglandin F1 alpha (6-keto-PGF1 alpha). Changes of the microcirculatory status and the rate of the blood flow in the conjunctival capillaries of 60 rabbits were observed with WXS-II microcirculation microscope. Pathological sections of the lungs and kidneys were studied. Our investigation showed the presence of microthrombi in the microvasculature. After treatment with anisodamine, the prothrombin time stayed in the normal range, fibrinogen consumption was lessened, adenosine-diphosphate-induced platelet aggregation was inhibited, thromboxane B2 and malondialdehyde concentrations were significantly lower than in the control group, and the elevated quantity of 6-keto-PGF1 alpha was spared. We concluded that the anti-platelet-aggregating, microcirculation-facilitating, thromboxane-B2-inhibiting, malondialdehyde-inhibiting, and 6-keto-PGF1 alpha-sparing effects of anisodamine are the important mechanisms of its dramatic therapeutic effect on DIC.

6-Ketoprostaglandin F1 alpha↗

PubMed1986

Microcorrosion casts in the microcirculation of skeletal muscle.

The authors review the contribution of microcorrosion cast studies towards clarifying the structure of skeletal muscle microcirculation. Former studies performed on naturally contracted muscles show the presence of a primary and a secondary arterial network and a capillary network. At the level of the capillary network pericyte imprints are present. Muscles characterized by different types of metabolism show different features of the capillary pattern. Other authors have affirmed that the extended muscle is characterized by long and straight capillaries, while the contracted one features clusters of vessels all around a muscle fiber. The authors have made the present observations in order to determine how the capillary pattern of muscles with different metabolism is modified by extension and shortening of the muscle belly. The capillary pattern observed appears very similar to that observed in former studies. The differences between the oxidative and the glycolytic muscle are evident in every condition of the muscle belly. These data confirm the theory that there is a permanent endogenous difference in microcirculation between oxidative and glycolytic muscle, determined by muscle fiber metabolism.

Animals↗

PubMed1985

Some experimental and methodological experiences on the selective inhibition of blood microcirculation in tumor tissues as the central mechanism of the cancer multistep therapy (CMT).

Microcirculation is a very sensitive process. Under hyperthermia and/or artificial tissue acidification bloodflow ceased regularly and reproducibly. This bloodflow inhibition imposes seemingly as a consequence of a progressing decrease of blood fluidity. However, blood flowing through irritated vessels is subjected to local heat and acidic milieu only for few seconds, whereas the vessels of the respective area are exposed to these conditions as long as they continue. Hence, it is important to look for lesions of the vessels, particularly for enhanced porosity.--Using light-conducting electrodes we have studied the perivascular glucose concentrations and the influence of oxygen deficiency on microvessels in vivo. In contrast to our expectation, we have failed to detect endothelial cell swelling. On the other hand, we could observe diminished blood fluidity under anaerobic conditions by use of a simple method with filterpaper strips.--In our tumor studies we achieved reproducibly microcirculation inhibition of about 95% in DS carcinosarcomas as compared to muscle by combining hyperglycemia with hyperthermia (100 min at 43 C degrees). Each of these measures applied alone resulted only exceptionally in an approximately comparable effect. For therapeutic purposes the combination of both seems to us the method of choice.--Controlled hypotension, which can be adjusted extremely well by NAD, caused blood flow inhibition selectively in the tumors.--The remarkable bloodflow inhibition in tumors is achievable in principle also in human tumors.

Animals↗

PubMed1985

Relation of the hepatic and splenic microcirculations to the development of lesions in experimental amyloidosis.

By the use of a perfusion technique for identifying blood vessels, it was found that amyloid lesions in mice have a close relation to the underlying microcirculation. The earliest lesions develop about arteriolar capillaries. With the onset of the lesions, circulation of plasma not only continues through the affected vessels but also extends into the entire volume of the surrounding lesions. Progression of the lesions follows the underlying microcirculation, and there is a continuing presence of circulating proteins. Other observations, from tracer studies using labeled plasma proteins and studies of unfixed, frozen, tissue sections following saline extraction, indicate that much of the early amyloid lesions in these animals is circulating plasma. It would appear that the onset and site of formation of the lesions is determined by arteriolar capillary injury rather than by polymorphism of SAA proteins. Structural amyloid fibril proteins may gain access to the lesions by either entry from the circulation or local formation.

Amyloidosis↗