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Results for “Microcirculation”

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At least 469 records · Page 26Linked to original sources

PubMed2005

Effect of rotational atherectomy on the coronary microcirculation in patients with angina pectoris.

OBJECTIVES: The coronary microcirculation can be impaired by ablated debris just after a rotational atherectomy procedure, but the specific effects of rotablation on the microcirculation have not been investigated. The present study examined the effects of rotational atherectomy on the coronary microcirculation by analyzing coronary flow reserve (CFR) and the component parameters of the coronary flow-pressure loop. METHODS: This study included 31 patients with angina pectoris who underwent stent implantation after rotational atherectomy and with < 50% diameter stenosis at 6-month follow-up (i.e. without clinical restenosis). The CFR, the flow-pressure slope index (FPSI) and zero-flow pressure were measured using the FloWire Doppler guidewire in both treated and untreated reference vessels without stenosis immediately after and on 6 months from the rotational atherectomy procedure. RESULTS: CFR and FPSI in the treated vessels were significantly lower than in the untreated reference vessels without stenosis just after rotational atherectomy (CFR: 2.1 +/- 0.5 vs 2.6 +/- 0.7, p < 0.05; FPSI: 1.61 +/- 0.8 vs 2.35 +/- 0.9 cm/sec/mmHg, p < 0.05), but no significant differences were observed in CFR or FPSI between these same sets of arteries at follow-up. There was also a significant correlation between the extent of attenuation of CFR and total ablation time (r = - 0.54, p < 0.01). CONCLUSIONS: Rotational atherectomy attenuates CFR by reducing coronary artery conductance, probably due to coronary microvessel obstruction with the debris ablated during the procedures of rotational atherectomy.

Aged↗

PubMed2005

[Application of air-plasma flow for the correction of microcirculation disorders during the treatment of diabetic foot syndrome].

Analysis of data on the treatment of 100 patients with purulent-necrotic forms of diabetic foot syndrome is presented. Patients were divided into two groups. In the first group (45 patients) treatment was conducted using traditional methods and techniques. In the second group (55 patients) during operation air-plasma cutting-coagulation device "Plazon" was used in NO-therapy mode. Nitric monoxide is known as multifunctional antioxidant substance, having great value in oxidative stress reactions. In the current study it was transported to the wound surface by air-flow of "Plazon" device. The condition of microcirculation in tissues was studied by computerized laser capillary flow analyzer "LAKK-01". It was shown that after removing inflammation in the healed wound, condition corresponding to characteristics of undamaged skin takes place in contrast to the patients from the group 1, where some asymmetry in the foot tissues microcirculation was shown as an evidence of functional and structural insufficiency of microcirculation system.

Adult↗

PubMedDate not supplied

[Investigation into microcirculation in the vascular bed of healthy people and patients at rest and during the LBNP test].

Computer capillaroscopy during the lower body pressure test (LBNP) provided additional information about the effects of orthostasis on blood microcirculation and separate estimation of blood velocity in arterial, intermediate and venous segments of capillaries. Microcirculation was demonstrated to be sensitive to the LBNP exposure as in healthy volunteered subjects, so in ischemic, including hypertensive, patients. The highest velocity of capillary blood and the lowest Kv were determined in ischemic patients including hypertensive, in whom venous velocity in capillaries prevailed over arterial (Kv < 1), whereas in healthy subjects Kv never fell below 1. 09. Results of the comparative investigations of blood microcirculation in healthy people and patients with various cardiovascular problems can be used in clinical and space medicine for assessment of the CVS functioning and orthostatic tolerance.

Adult↗

PubMed2006

Metronidazole improves intestinal microcirculation in septic rats independently of bacterial burden.

To explore the effects of metronidazole (Me) on intestinal microcirculation in septic rats, intravital microscopy (IVM) following 16 hours of colon ascendens stent peritonitis (CASP model) was used. Four groups of animals were studied: control group (sham operation) and CASP group, each with and without Me treatment (10 mg/kg i.v.). In order to investigate the substance-specific effects of Me independently of the antibacterial effects within a pathologically altered microcirculation, a second experimental series with lipopolysaccharide challenge (LPS model) was carried out. The LPS model consisted of the four groups (control animals and LPS animals (15 mg/kg i.v. LPS from E. coli) with and without Me). IVM in the LPS experiments was performed following a two hour observation period. Me treated CASP or LPS animals, as compared with untreated, demonstrated significant improvement of functional capillary density (FCD) of the intestinal wall. The increase in the number of leukocytes firmly adhered to the endothelium (leukocyte sticking) in the untreated CASP or LPS animals within the V1 venules of the intestinal submucosal layer, was significantly reduced in the Me treated animals. In conclusion, Me exerts beneficial anti-bacterial and anti-inflammatory effects within the septic microcirculation.

Animals↗

PubMed2006

[Effects of Naoan tablets on brain hemodynamics and cerebral microcirculation of soft membrane in anesthetized dogs and rats].

OBJECTIVE: To study the effects of Naoan tablets on brain hemodynamics and cerebral microcirculation of soft membrane. METHOD: Cerebral blood stream flux, resistance of blood vessels, blood pressure and heart rate were used as observation indexes in hemodynamics experiment. Artery caliber and the number of capillaries with recovered blood stream were used as observation indexes in microcirculation experiment. RESULT: Naoan tablets at dose of 0.5 g x kg(-1) and 1.0 g x kg(-1) could enhance cerebral blood stream flux, decrease resistance of blood vessels, and reduce blood pressure. While no effects on heart rate. Naoan tablet at dose of 0.7 g x kg(-1) and 2.1 g x kg(-1) could increase the number of capillaries with recovered blood stream and enlarge the artery caliber of soft membrane in rats. CONCLUSION: Naoan tablets can improve the indexes of hemodynamics and cerebral microcirculation of soft membrane.

Anesthesia↗

PubMedDate not supplied

[Disorders of physiological parameters of the body (lipid peroxidation and microcirculation) after naso-orbital injuries and the methods of their correction].

A naso-orbital injury is often associated with a craniocerebral injury due to the close anatomical localization of the facial and cerebral compartments of the skull. Patients with such injuries showed enhancement of free-radical lipid oxidation and microcirculation disorders. They were controlled by traditional therapeutic methods in combination with antioxidants of direct and indirect action (ascorbic acid, flacumin, alpha-tocopherol acetate, pentoxifylline ) that were given in standard doses. Improvement of microcirculation and decrease of free-radical oxidation of lipids were followed by faster normalization of bioelectric activity and hemodynamics of the brain and earlier clinical recovery. Microcirculation parameters recorded during biomicroscopy of vessels of the bulbar conjunctiva can be used for evaluating cerebral circulation because vessel responses of the eyeball and the brain are similar.

Adult↗

PubMed1991

[Effect of 654-2 on the cerebral blood flow in patients with ischemic cerebrovascular disease by measurement of 133Xe rCBF and the microcirculation of bulbar conjunctiva].

Eighteen patients with cerebrovascular disorder were observed comparatively using 133Xe rCBF measurement and microcirculation test of bulbar conjunctiva before and after treatment with 654-2. Remarkable decreasing of blood flow in the brain and improving of bulbar conjunctiva microcirculation were found after treatment. We consider that the same drug caused the different change of blood flow in and out brain may due to the reaction of micrangium tissue construction, nerve regulation and different organ's micrangium to Ach. We recommend 133Xe as a objective measurement to estimate brain blood flow. The value of treatment of ischemic cerebrovascular disorder by 654-2 and raising microcirculation test as a objective measurement remains to discussed.

Adult↗

PubMed1991

[Effect of ulinastatin on microcirculation under excessive hemorrhage and fluid therapy].

Microcirculation during excessive hemorrhage and fluid therapy under anesthesia with or without associated treatment by ulinastatin (urinary trypsin inhibitor) was studied by using the rabbit ear chamber. Sixteen rabbits were divided into 2 groups; 8 rabbits without ulinastatin treatment (C group) and rabbits treated with ulinastatin (U group). After blood withdrawal, hemodynamic disturbance appeared in both groups. But the catecholamine concentration showed no increase in either groups. Significant differences between the groups were found only in urinary output and microcirculation. These were well maintained during hemorrhage in the ulinastatin treated group. It is concluded that ulinastatin is effective in maintaining microcirculation during excessive hemorrhage and fluid therapy.

Animals↗

PubMed1990

[Vascular permeability, microcirculation and biologically active substances in patients with hemorrhagic fever with renal syndrome].

As many as 56 patients with associated hemorrhagic fever and the renal syndrome were examined for vascular permeability, microcirculation and blood plasma histamine, serotonin, kallikrein and prekallikrein. In all the disease periods, the majority of the patients (n-52) demonstrated a rise of vascular permeability for protein and liquid part of the plasma, with this being marked in particular in the oligoanuric period. Besides, significant perivascular and intravascular changes in microcirculation were noted in the oligoanuric and polyuric disease periods. It was established during examination of biologically active substances that the greatest shifts were experienced by the kinin system. Sometimes the content of kallikrein surpassed the control values more than 7-fold. Less pronounced changes were seen in blood plasma serotonin and histamine. A direct correlation was established between vascular permeability, microcirculation and the content of all biologically active substances explored by the authors. The strongest correlation was found to exist between the above parameters and the kinin system of blood plasma.

Acute Disease↗

PubMed1991

[Cochlear microcirculation in living guinea pigs following explosion].

The cochlear microcirculation in living guinea pigs was observed, explosion was then imposed on the left ear and the velocity of blood cell flow and vessel diameters were measured within one hour. The results showed that: 1. there was an orderly stable movement of blood cells in all vascular beds under normal conditions; 2. the flow rate in both spiral ligament and stria vascularis increased promptly after explosion, that in the spiral ligament might return to normal within 30 minutes with vasodilatation, indicating increased blood supply early after explosion; 3. there was no relationship between changes in microcirculation and hearing loss and hair cell damage. The cause of hair cell damage and hearing loss were discussed and the techniques of vital microscopic studies of cochlear microcirculation assessed.

Animals↗

PubMed1990

[The influence of electric needling "Juci" on nail-bed microcirculation of apoplectic patients].

UNLABELLED: "Juci" is one kind of acupuncture methods. It is that acupoints of the one side are used to treat the disease of the another side. In order to prove this theory and the difference from puncturing paralytic side (Tanci) 30 patients with hemiplegia due to cerebral infarction were observed under the same condition and stimulative parameter. Selecting points: Hegu and Quchi acupoint were electrified for 15 minutes. The changes of Nail-bed microcirculation were observed for half an hour and recorded after pulling out needles. CONCLUSION: Through the observation of outline of blood vessel, colour of blood vessel ansa, ansa's top blood-stasis of blood vessel, condition of blood flow and the rate of blood flow before and after Juci (puncturing healthy side) they were different or quite different on the hemiplegic side (p less than 0.05 or p less than 0.01). however, only the colour of blood-vessel ansa and rate of blood flow were different, others had no statistical significance on healthy side. Though puncturing paralytic side can make the nail-bed microcirculation improved, only rate of blood flow was different. Others had no statistical significance. In short both Juci and Tanci improve the nail-bed microcirculation of hemiplegic side, but the former is much better than the latter.

Acupuncture Therapy↗

PubMed1990

[Tongue tip microcirculation in patients with different symptoms].

Observations of tongue tip microcirculation were made on 104 patients with different symptom-complex [5 groups: Yin deficiency, Yang deficiency, Qi.blood deficiency, Qi stagnation-blood stasis, damp-heat] in view of TCM, and on 100 healthy persons. 10 indicators including the transverse diameter of the fungiform papillae, morphology of microvascular clumps in the tongue papillae, congestion of the top of microvascular loop, loop dilation, blood color, hemodynamics in microvascular loop, exudation, hemorrhage and loop morphology were observed. The results were: patients of each group were found to have to different degree microcirculation dysfunction; every group differed with Qi stagnation-blood stasis group of being most different. The numbers of abnormal indicators: Qi stagnation-blood stasis group had all 10; Yang deficiency group 9; Yin deficiency and Qi-blood deficiency group 8, 8 respectively; damp-heat group 7. This study discussed the relationship between tongue tip microcirculation of each group and the changes of tongue picture and typing of differentiation of symptoms and signs in view of TCM.

Adolescent↗

PubMed1989

[State of microcirculation homeostasis in children with rheumatism].

Microcirculatory homeostasis was studied in 107 children suffering from rheumatic fever. Conjunctival microcirculation and platelet aggregation were examined. The content of circulating immune complexes and medium-size molecules was measured in the blood. Microcirculation was investigated in 137 healthy children aged 3 to 15 years, making up a control group. Comprehensive investigation of microcirculation in children suffering from rheumatic fever enables one to define the activity of the rheumatic process at the early times of the illness and to ensure timely administration of adequate antirheumatic therapy.

Adolescent↗

PubMed1989

[State of the blood platelet link of hemostasis and microcirculation in patients with ischemic heart disease during plasmapheresis treatment].

The paper provides the results of studies into plasmapheresis-induced changes in the thrombocytic link of hemostasis and microcirculation in 40 patients with coronary heart disease (CHD). Repeated sessions of plasmapheresis (P) were found to produce an inhibitory effect on platelet aggregation and to improve microcirculation in CHD patients with signs of increased platelet functional activity. In CHD patients with low platelet functional activity, the first P session was demonstrated to cause an increase in platelet functional activity whereas the subsequent sessions inhibited platelet aggregation. No significant microcirculatory improvement was seen in this group of patients. Heparin and rheopolyglucin given to control patients exerted no substantial effect on the thrombocytic link of hemostasis and microcirculation.

Adult↗

PubMed1989

Hypoperfusion of the intestinal microcirculation without decreased cardiac output during live Escherichia coli sepsis in rats.

In order to determine the intestinal microvascular responses to normotensive, high cardiac output (CO) bacteremia, we measured vascular diameters and blood flow at different levels of the intestinal microcirculation during live E. coli bacteremia in male Sprague-Dawley rats (n = 16). Precollicular brainstem transection was used to allow study free of drug anesthesia. The microcirculation of a loop of small intestine (with intact neurovascular connections) was observed by in vivo video microscopy and optical Doppler velocimetry at a magnification of x1,500. Intraluminal microvessel diameters and red cell velocity were measured in successive branches until the vessel entered a villus. CO was measured by transpulmonary thermodilution. Intravenous infusion of 1 x 10(9) live E. coli caused a 20% increase in CO at 50 min and a 14% decrease in systemic vascular resistance. However, microvascular blood flow to the small intestine decreased by 27% at 1 hr and by 56% at 2 hr. Progressive arteriolar constriction (25-50%, P less than .05) occurred at all levels of the intestinal microcirculation. These data indicate that intestinal hypoperfusion caused by arteriolar constriction occurs during high CO bacteremia. This hypoperfusion could contribute to mucosal injury and intestinal mucosal barrier dysfunction during sepsis.

Animals↗

PubMed1989

The defensive role played by the gastric microcirculation.

Microcirculation plays an important role in the maintenance of functional integrity of the stomach and in the provision of its defense mechanisms against damage. Changes in blood flow in the gastro-duodenal mucosa, brought about by the local release of vasoactive or cytotoxic mediators, including free-radicals, the eicosanoids thromboxanes and leukotrienes, and the related phospholipid, PAF, have been implicated in the pathogenesis of various forms of peptic ulceration and erosive gastritis. Damage to microvessels and vascular endothelium leading to disruption of microcirculation is considered to be an initial event in the development of such lesions. Furthermore, preservation of microcirculation by prostaglandins is likely to make an important contribution to the overall protection of the gastric mucosa by these agents. Studies on the hemostatic mechanisms in the gastric mucosa indicate that bleeding is initially arrested by a coagulation process that is independent of platelet aggregation. Thus, the identification and characterization of microcirculatory events is of major importance in the understanding of pathophysiological processes in the gastric mucosa.

Humans↗

PubMed1989

A comparison of the effects of photodynamic therapy on normal and tumor blood vessels in the rat microcirculation.

The effects of light activation of the tumor photosensitizer dihematoporphyrin ether (DHE) were studied in the microcirculation of the rat cremaster muscle. Arterioles and venules in an implanted chondrosarcoma were studied by in vivo television microscopy and were compared to normal vessels of the same size elsewhere in the preparation and in control preparations. Activation with green light (530-560 nm, 200 mW/cm2, 120 J/cm2) 48 h after intraperitoneal injection of DHE (10 mg/kg body wt) resulted in significant narrowing of diameters of red blood cell columns in tumor arterioles and venules. The response in normal and control arterioles and venules was not significantly different from that seen in the tumor vessels except that the control arterioles did not remain significantly constricted during the treatment period. Treatment resulted in stasis of blood flow in 90% of tumor and normal arterioles at the completion of light activation. In venules, stasis of blood flow was observed in 75% of tumor and 70% of normal vessels. Vasoconstriction was the primary response in arterioles, while thrombosis predominated in venules. Morphologic assessment of light-activated vessels in the cremaster preparation by transmission electron microscopy revealed platelet aggregation with damage to endothelial cells and smooth muscle cells. Perivascular effects observed included interstitial edema and damage to skeletal muscle cells. In the tumor-bearing preparation, no direct cytotoxic effect on the tumor cells was shown. The surrounding vessels exhibited similar vascular stasis, but the lining cells appeared minimally affected. Photoactivation of DHE results in significant changes in the microcirculation which lead to stasis of blood flow. In this model, the response was similar for the normal microvasculature and for the microcirculation of an implanted chondrosarcoma. These effects may account, in part, for the mechanism of action of photodynamic therapy.

Animals↗

PubMed1988

New aspects of the theory of microcirculation.

New aspects and details of the mechanism of the microcirculation in the tissues are discussed in the paper. Particular attention is payed to the role of the blood pressure amplitude for the filtration and resorption processes through the capillary wall. A new model of the microcirculation is discribed in which the interstitial space is considered as a functional unit determining the intensity of the transcapillary exchange processes. The components of the hydraulic interstitial pressure are characterized as well as the process of formation and transport of limphatic fluid. The proposed model is a base for the better understanding of the theory of microcirculation.

Humans↗