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At least 1,801 records · Page 100Linked to original sources
PubMed1992

Evaluation of microcirculation in the tumor-bearing liver of rabbits by laser-Doppler flowmetry.

Hemodynamic changes in normal liver tissue and in intrahepatic tumors (Vx2 carcinoma) after occlusion of the hepatic arterial branch or the portal branch (ex. 1), and with intrahepatic arterial infusion of vasoactive agents (ex. 2) were studied in rabbits by a laser-Doppler flowmeter. Ex. 1: After occlusion of the hepatic arterial branch to the main lobe, laser-Doppler flow (LDF) in main lobe normal tissue decreased by 11 +/- 11% in the control group, 37 +/- 37% in group Ia (tumors were 10-20 mm in diameter) and 49 +/- 37% in group Ib (tumors were 25-50 mm), so it seemed that the proportion of portal blood flow in the normal tissue microcirculation decreased with tumor growth. The tumor LDF decreased by 88 +/- 13%. After occlusion of the portal branch, the normal tissue LDF in the main lobe decreased and then recovered slightly (most evident in the control group and least in group Ib). This recovery was probably due to the hepatic arterial buffer response. The tumor LDF decreased by 36 +/- 10% in group Ia and 11 +/- 17% in group Ib. There was no difference between group I (tumors were implanted directly) and group II (tumors were implanted via portal vein). Ex. 2: Adenosine and prostaglandin E1 increased blood flow in the normal tissue and decreased the tumor blood flow, while angiotensin II had the opposite effect. Vasoactive agents can be used to selectively increase or decrease tumor blood flow and are available as adjuvants for the treatment of liver tumors. Adenosine may enhance the selective tumor heating in local hyperthermia.

Animals↗
PubMed2004

Effects of acupuncture on hemorheology, blood lipid content and nail fold microcirculation in multiple infarct dementia patients.

Forty-six cases of multiple infarct dementia (MID) in the treatment group were treated by acupuncture with the principle of supplementing the inferiority to clear the superiority and regulating spirit to invigorate intelligence. Changes of the blood lipid content, hemorheological indexes and nail fold microcirculation in the treatment group were compared with those in the randomly assigned control group. The data collected showed that the changes in the treatment group were remarkable, and part of them were superior to their counterparts obtained in the control group by statistical analysis. It is indicated that acupuncture can effectively regulate the affected hemodynamic state in MID.

Acupuncture Therapy↗
PubMedDate not supplied

Chondrodiatasis in rabbits: a study of the effect of transphyseal bone lengthening on cell division, synthetic function, and microcirculation in the growth plate.

The effects of chondrodiatasis on chondrocyte division, matrix synthesis, and microcirculation in rabbit growth plate were studied. The procedure did not produce any significant change in the percentage of cells labeled with tritiated thymidine, the intensity of radioactive sulfate labeling of the matrix, or the blood supply of the physis. These findings suggest that the procedure does not work by stimulating cell division, synthetic function, or vascularity of the plate, but rather by stretching the matrix passively.

Animals↗
PubMed2004

[Effect of low-intensity He-Ne laser irradiation on rat mesenteric microcirculation].

Changes in microcirculation during low-intensity He-Ne laser irradiation were studied by measurement of blood vessels and lymphangions' diameter in anesthetized rat mesentery using method of videomicroscopy in vivo. We demonstrated that the red coherent light induced a significant increase in contractility of vessels' smooth muscle cells. The flow decreased in the mesenteric microvessels during H2O2-mediated oxidant stress was restored after He-Ne laser irradiation.

Animals↗
PubMed2004

[Assessment of changes in peripheral microcirculation in type I diabetics with laser doppler flowmetry].

GOAL: To make out a methodology and assessment of peripheral microcirculation with laser Doppler flowmetry (LDF) in patients with type I diabetes mellitus and to compare their results to findings in healthy control people using frequency analyses. METHODOLOGY: A group of 32 patients suffering from type I diabetes on an average for 14 years (group A) has been examined. The patients suffered from a basic angiology disorder in arteries of lower extremities. Peripheral circulation in lower extremities has been examined via laser Doppler flowmetry. The same tests have been done in a group of 40 healthy people (group B). RESULTS: Basic evaluation revealed no statistical differences between groups A and B at rest (TO). Significant differences showed up during vasodilation test (T2). Intensity of perfusion in group A was 37 +/- 23 arbitrary perfusion units (PU) compared to 81 +/- 43 PU in group B (p < 0.001). During perfusion following ischemisation (T1) levels of blood circulation in groups A and B were 71 +/- 39 PU compared to 121 +/- 89 PU (p < 0.018). During frequency analyses the intensity of slow vasomotion (SV) in group A was already generally lower at rest (TO) 0.46 +/- 0.42 PU compared to 1.12 +/- 0.62 PU (p < 0.011) in group B. During the reperfusion phase following ischemisation (T1) intensity of SV was 1.8 +/- 0.78 PU compared to 2.82 +/- 1.58 (p < 0.17). Following vasodilation test (T2) perfusion was 0.79 +/- 0.65 PU compared to 1.86 +/- 1.31 (p < 0.009). In areas of fast vasomotion (FV; frequency 0.210 - 0.420 Hz) there were significant differences between group A and B at rest (TO) and during vasodilation test (T2). At rest 0.08 +/- 0.02 PU compared to 0.19 +/- 0.05 PU (p < 0.006). During vasodilation test 0.14 +/- 0.03 PU compared to 0.28 +/- 0.11 PU (p < 0.004). CONCLUSION: This study presents an original examination protocol and findings. Significant differences were identified in peripheral circulation of patients suffering from solely type I diabetes mellitus and control people. So called spontaneous venous reactivity (vasomotion) was in type I diabetics significantly lower already at rest and especially in reaction to vasodilation stimulus. The differences can't be still clearly explained but there is a suspicion they are a result of an impaired endotelial and autonomous function in type I diabetes mellitus. The method of frequency analyses of LDF records enables to give precision to peripheral blood circulation evaluation. It could be used to detect early changes in blood circulation as early as at rest.

Adult↗
PubMedDate not supplied

The effects of Celecoxib on inflammation and synovial microcirculation in murine antigen-induced arthritis.

OBJECTIVE: There is controversy about the effects of cyclooxygenase-2 (COX-2) on adhesion molecules and the microvasculature in inflamed tissue. Thus, the aim of this study was to assess COX-2-expression in Antigen-induced Arthritis (AiA) and to investigate the effects of selective COX-2 inhibition by Celecoxib (4-[5-(4-methylphenyl)-3-(trifluoromethyl)-1H-pyrazol-1-yl] benzenesulfonamide) (CXB), on synovial microcirculation and adhesion molecule expression in arthritic as well as healthy mice. METHODS: Balb/c mice were allocated to 4 groups; 2 control groups with saline or CXB and 2 groups with AiA which also received saline or CXB (30 mg/kg BW in 0.3 ml solution). The severity of arthritis was assessed by changes in the transverse joint diameter On day 14 after AiA-induction, the patella tendon of the left knee joint was microsurgically resected and intravital fluorescence microscopy on synovial tissue was performed. Finally, the knee joint was removed for histology and immunohistochmistry. RESULTS: COX-2-expression in the inflamed synovium was demonstrated by immunohistochemistry. Application of Celecoxib resulted in a significant reduction in the rolling leukocyte fraction as well as in the number of leukocytes adherent to the endothelium (0.25 +/- 0. 1 and 96 +/- 34 cells/mm2 respectively) in comparison to the untreated animals with AiA (0.44 +/- 0.03 and 206 +/- 22 cells/mm2 respectively). Additionally, CXB-treated arthritic animals showed significantly less knee joint swelling and reduced adhesion molecule expression. CONCLUSION: In the present study, COX-2 expression in the synovial tissue of mice with AiA could be demonstrated. Selective COX-2 inhibition with CXB resulted in reduced leucocyte-endothelial cell interactions and decreased adhesion molecule expression. Evidence for a protective role of COX-2 in mouse AiA was not found.

Animals↗
PubMed1992

[Critique of using the Staverman sigma reflection coefficient in the theory of microcirculation].

The usage of the reflection coefficient sigma defined by Staverman within the theory of microcirculation in tissues requires free perfusion through semipermeable membranes, which does not exist in the reality of tissue blood supply. In accordance to the principle of continuation of the hydraulics the reflection of colloidosmotic particles at semipermeable membranes in tissues does not comply with the condition of steady state regimes. Considering this fact the relevance of sigma in theoretical and practical investigations is challenged.

Animals↗
PubMed1979

[The systemic circulation and microcirculation of the periodontium vital microscopy and histological studies of incisors of rats (author's transl)].

A new classification of the angioarchitecture and blood flow is proposed in light of the results of vital microscopy studies of the windowed periodontium and gingiva of the incisors of rats. The flow pattern and the rate of blood flow are different in different vessels. The flow of blood in segmented and interconnected arterial and venous vascular sections in the alveolar and marginal periodontium corresponds to what is known as systemic circulation, whereas that in arterioles, capillaries, and venoles must be considered as belonging to what is referred to as microcirculation. Subepithelially, the microcirculatory elements constitute a nutritive, typically ordered capillary network as contrasted with the random spatial arrangement of capillary loops in the alveolar periodontium. Numerous anastomoses provide the basis for possible functional adaptation, leading to the formation of polygonal ring closures in the alveolar region. The interpretations of functional findings are based upon histotopological reexaminations.

Alveolar Process↗
PubMed2005

Increase plasma viscosity sustains microcirculation after resuscitation from hemorrhagic shock and continuous bleeding.

Resuscitation from hemorrhagic shock (50% of blood volume, BV) followed by continuous bleeding (20% of BV per hour, over the entire observation time, 90 min) was studied in the unanesthetized hamster chamber window model. Blood losses equaled 100% of total BV. A single volume infusion (resuscitation) was performed 60 min after hemorrhage using 25% of the BV with 10% hydroxyethyl starch (HES 200, group HES4), or a mixture of HES 200 with 0.3% or 0.6% (w/v) alginate (groups HES7 and HES10, respectively) leading to solutions with a uniform colloidal oncotic pressure (84-87 mmHg) and viscosities ranging from 3.8 to 9.8 cp. Results showed all solutions to be similar immediately after resuscitation (10-15 min) and diverged after this initial period. The viscosity-enhanced solutions showed improved and longer-lasting effects (90 min) relative to the conventional low viscosity, in terms of sustained arterial blood pressure, microvascular flow, capillary perfusion, and laboratory parameters. All microvascular parameters 90 min after resuscitation with low viscosity fell back to the shock level. Improved recovery obtained with a hyperviscous plasma expander was related to microcirculation shear stress preservation, leading to improve blood flow by lowering peripheral vascular resistance when compared with low viscosity resuscitation. These findings suggest the possibility of using hyperviscous plasma expanders to prolong the period for initial treatment of blood losses and definitive institution therapy.

Alginates↗
PubMedDate not supplied

[Mechanisms of lesions of nasal mucosa microcirculation in allergic rhinitis].

Morphological study of tissue of the mucous membrane of the nasal cavity in 36 patients which was removed in the process of surgical treatment showed a marked disorder of microcirculation. Immunoluminescent studies revealed fixed globulins and a complement in the vascular wall.

Complement System Proteins↗
PubMed2005

[The normoxic therapeutic compression effect on microcirculation in acute stroke].

The study evaluates efficacy of two hyperbaric therapeutic regimes--1,-51,1 atm and 1,2 atm in patients with an acute ischemic stroke. Acid-base equilibrium dynamics of capillary and venous blood, whole blood and plasma, platelet aggregation and lipid peroxidation were investigated. An analysis of the data revealed that, comparing to the conventional method, barotherapy in stroke is accompanied by a marked therapeutic effect. Barotherapy or normoxic therapeutic compression is principally different from other methods of oxygen therapy, because it is not resultant in blood plasma hyperoxygenation and in lipid peroxidation augmenting. Activation of tissue respiration in barotherapy accompanied by normalization of lipid peroxidation process and CO2 resources restoration leads to renewal of MKT microcirculation and autoregulation, thus providing a stable therapeutic effect of the method in brain ischemia.

Acute Disease↗
PubMed2005

[Effects of L-arginine on the microcirculation of rat island skin flaps after ischemia- reperfusion].

OBJECTIVE: To investigate the effects of L-arginine on the microcirculation and survival of rat island skin flaps after ischemia-reperfusion. METHOD: A right lower abdominal island flap was created in SD rats and the microcirculatory blood flow in these flaps measured with laser Doppler velocimetry following L-arginine injection via the contralateral femoral artery. Both NO and malondialdehyde (MDA) levels in the flaps were assayed and the survival of the flaps replanted in situ was evaluated 1 week later. RESULTS: L-arginine treatment caused increase in the microcirculatory blood flow of the flaps and elevation of NO while and decrease of MDA levels. The survival rate of the flaps with L-arginine treatment was significantly higher than the flaps from saline-treated and normal rats. CONCLUSION: L-arginine can improve the survival of island flap through increasing the microcirculatory blood flow and lessening ischemia-reperfusion injury of the flaps.

Animals↗
PubMed2005

[Twenty-four hour blood pressure monitoring and condition of microcirculation in geriatric patients with hypertension].

Features of a daily structure of blood pressure elderly patients with isolated systolic or systolo-diastolic essential hypertension are shown, features of microcirculation in conjunctivae vessels are revealed depending on essential hypertension from, attempt to estimate daily average parameters of blood pressure elderly patients with isolated systolic or systolo-diastolic essential hypertension is made.

Aged↗
PubMed2005

Prognostic impact of the detection of microcirculating tumor cells by a real-time RT-PCR assay of tyrosine hydroxylase in patients with advanced neuroblastoma.

Molecular detection of microcirculating or microdisseminated disease (MDD) with a sensitive methodology could contribute to a better treatment for children with neuroblastoma. To detect circulating neuroblastoma cells, we developed a quantitative assay for the analysis of tyrosine hydroxylase (TH) gene expression. We analyzed 155 samples of peripheral blood (PB) from 25 patients with neuroblastoma in advanced stages (8 stage III and 17 stage IV). TH mRNA was analyzed by RT-PCR assay using TaqMan technology. PB samples (n=25) from donors were used for normalizing TH, and values <7 were considered negative. With a median follow-up of 40 months (range 15-73 months), 9 patients relapsed and 8 patients died of progressive disease. TH expression was detected in the PB of 16 patients (64%) at diagnosis. During treatment, 10 patients had positive samples and 9 patients were still positive for circulating tumor cells at the end of treatment. Actuarial 3-year event-free survival of patients with PB positive for TH mRNA after induction therapy (40%) (p=0.018) and at the completion of treatment (33%) (p=0.003) were significantly worse than the survival of TH-negative patients (86 and 87%, respectively). In multivariate analysis, MYCN status and TH expression in PB at the end of treatment remained significant prognostic factors. Our results show that patients with advanced neuroblastoma who have PB positive for TH at the end of treatment seem to have a worse prognosis compared with patients with undetectable TH. These results suggest the usefulness of MDD monitoring in neuroblastoma.

Adolescent↗
PubMed1992

Differentiation of the anti-shock effect of ulinastatin from steroid hormone, by the continuous observation of microcirculation dynamics.

The effects of ulinastatin (UST) and methyl prednisolone (MPS) on endotoxin induced shock were compared by the criterion of microcirculation dynamics in rat mesenterium and plasma phospholipase A2 (PLA2) activity in modified Shwartzman reaction model. The mean arterial pressure and red cell velocity were well maintained when MPS was administered during endotoxin induced shock. In the case of UST, superior anti-shock effects, indicated by reduced vasoconstriction, were obtained when it was administered prior to endotoxin induced shock. The anti-shock effect of UST, similar to MPS, was supported by the change of serum PLA2 activity. Therefore, concerning the administration timing of anti-shock drugs, MPS should be administered after shock occurs, and UST is most effective as a prophylactic treatment. UST has an anti-shock effect like steroid hormone.

Animals↗
PubMedDate not supplied

[Local microcirculation in persons with primary pterygium, as evidenced by fluorescein-angiographic studies].

Fluorescence angiography was used to study local microcirculation in 20 patients (9 females and 11 males) aged 18 to 48 years who had primary pterygium. All pterygiums were divided into unprogressive (10 patients, 10 eyes) and progressive (10 patients, 10 eyes). The revealed pattern of the microangioarchitectonics of pterygium suggests that there is an independent isolated microvascular system that comprises a system of posterior conjunctival vessels, relatively large arterial trunks, and a developed newly formed vasculature. Unprogressive pterygium is characterized by a slightly developed neovasculature in the tissue of pterygium, in its head in particular, while the progressive form is marked by a rich neovasculature with pronounced extravasal fluorescence.

Adolescent↗
PubMed1975

Fluorocarbon emulsions and cerebral microcirculation.

Mice were exchange transfused with a fluorocarbon emulsion (FC-80). Their hemotocrits were reduced to levels of 10-15. They were examined within 1 hour of completion of normal or slightly accelerated in the majority of the mice. Acceleration may have been due to reduced "blood" viscosity. All mice with normal or reduced transit times displayed reversible increases in brain NADH levels when they were exposed to room air or 100% N-2 for brief periods, rather than to the atmosphere of 100%O-2 used to support life in these mice. A small group of mice with prolonged fluorescein transit tended to display NADH levels that failed to rise when O-2 was reduced in the inspired air. In this small subgroup, microcirculatory failure had apparently produced anoxia and maximal NADH levels even before the supply of inhaled O-2 was reduced. Many FC-80 mice displayed reversible decreases in brain pO-2 levels when inspired O-2 was reduced. Pentylenetetrazol activated the EEG of FC-80 mice. The EEG activity was reversibly reduced when the animals were briefly exposed to room air or N-2. These data suggest that fluorocarbon emulsions can support brain microcirculation, oxygenation, and electrical activity in vivo, a result which is consonant with the observations of others who have performed in vitro experiments, or observed long-term survival.

Animals↗

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