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At least 217 records · Page 12Linked to original sources

PubMed1999

Confocal laser scanning microscopy of leukocyte adhesion in the microcirculation of the inflamed rat knee joint capsule.

OBJECTIVE: The aim of the study was to develop a model of intravital microscopy of the microcirculation of the rat knee joint capsule in acute inflammation with the help of confocal laser scanning microscopy (CLSM). METHODS: The microvascular architecture of the joint capsule was investigated by the use of corrosion casting techniques. Knee joint capsule microcirculation of anesthetized rats could be visualized by dissection of the ligamentum infrapatellare rectum and application of a CLSM. Rhodamine 6G was used as a leukocyte marker. An acute arthritis was induced by intraarticular injection of 0.1 mL of 1% Carrageenan solution. Each experiment lasted for 3 h. Leukocyte adhesion (LA) was measured in 100 microns of vessel length. Leukocyte-rolling velocity (Vwbc), systemic leukocyte count (WBC), and differential blood count (DBC) were monitored in defined intervals. Finally, myeloperoxidase (MPO) activity in frozen-tissue homogenate served as a parameter of neutrophil content. RESULTS: Leukocyte adhesion in carrageenan-treated animals was 9.9 +/- 0.2 leukocytes/100 microns vessel (mean +/- SD; n = 6), while sham- treated animals had 2.8 +/- 0.2. Monoclonal antibodies (MAb) to alpha 4 integrin (0.2 mg/kg) reduced LA to 2.6 +/- 0.1 (p < 0.01). Vwbc/gamma quotients were 0.37 micron s/s in control animals and 0.53 micron s/s in anti-alpha 4-treated animals (p < 0.01). Changes in DBC were marked by lymphopenia and granulocytosis after 180 min. At this time point-control animals had 5.1 G/L LC and 2.6 G/I PMN. Animals treated with unspecific antibody had 4.7 G/L LC and 4.9 G/L PMN, while anti-alpha 4-treated animals had 10.6 G/L LC and 2.4 G/L PMN. Photometrically determined extinction of oxidized tetramethylbenzidine (TMB; measure for MPO content) was 1.058 +/- 0.555 in control animals and 0.245 +/- 0.093 in sham-treated animals. Tissue homogenate from unspecific IgG treated group had 0.776 +/- 0.140 and from anti-alpha 4-group 0.334 +/- 0.155 (p < 0.05). CONCLUSIONS: Confocal laser scanning microscopy is a tool for the study of the microcirculation in nontransparent organs. The microcirculation of the acutely inflamed rat knee joint capsule can serve as a model of integrin-mediated LA in vivo. Antiadhesive treatment of animals can reduce the tissue infiltration with inflammatory cells.

Animals↗

PubMedDate not supplied

Pathomorphological changes in microcirculation of pancreas during experimental acute pancreatitis.

BACKGROUND/AIMS: Severe acute pancreatitis is prevalent in Eastern Bohemia (a part of the Czech Republic) and remains a very difficult problem to manage. Recent studies in treatment there are quite frequent but a direct view into the pancreas during its inflammatory process is very rare. Only information about a normal pancreatic microvascular bed appears to be available. This study was designed to explore pathomorphological changes in pancreatic microcirculation at the start and during the development of acute pancreatitis. METHODOLOGY: A group of 50 laboratory white rats was studied. The acute pancreatitis was induced by the modified method of Siech et al. The method of clamping of biliopancreatic duct and stimulation of external secretory tissue by a cholecystokinin and secretin and oral (orogastric tube) ethanol administration was performed. The pancreatic microvascular patterns were observed by using histochemical and corrosion casts methods. RESULTS: The study of the corrosion casts of pancreatic microcirculation in the scanning electron microscope and histochemical studies demonstrated the visible reduction of the pancreatic microvascular bed 18 hours after induction of acute pancreatitis. The microvascular bed is not fully destroyed until 48 hours of acute pancreatitis. CONCLUSIONS: The model of acute pancreatitis using postoperative application of ethanol to the digestive tract after stimulation of pancreas by cholecystokinine and secretin in the rats seems to be real and useful. The study of the corrosion casts of microcirculation in the scanning electron microscope and histochemical studies demonstrated the visible reduction of the pancreatic microvascular bed 18 hours after induction of acute pancreatitis. The microvascular bed is not fully destroyed until 48 hours of running acute pancreatitis, as some "islets" of the vital tissue still have undestroyed microvessels at this time. Despite the above-mentioned serious changes, restricted pancreatic microcirculation enables blood and medicament distribution to the still intact pancreatic tissue.

Acute Disease↗

PubMed2001

[Current techniques for the clinical evaluation of the microcirculation].

Three main types of approaches are currently used for the exploration of the microcirculation in man: Clinimetric measurements of the cutaneous temperature (thermometry), skin color (chromametry) and tissue volume (leg or foot volumetry) allow a quantification of clinical indexes of skin blood flow, blood volume and edema that are useful in therapeutic trials. Global parameters evaluating the hemodynamic or nutritional efficacy of the microcirculation in a tissue sample (laser Doppler and TcPO(2)) are easy to perform in clinical routine. TcPO(2) measurements through Clarke electrodes or fluorescence lifetime imaging technology evaluate the nutritional efficacy of the microcirculation. Laser Doppler devices are producing a semi-quantitative index of superficial tissue perfusion, that can be split into a volumic and a velocimetric components; its high sensitivity makes it a valuable tool for clinical research, mainly for dynamic measurements of reactivity of the superficial microcirculation to various stimuli. New instruments are able to use two different frequencies in order to compare tissue perfusion at different depths beneath the skin surface. The combination of a laser probe and a small automate can produce a two-dimensional image allowing the evaluation of spatial heterogeneity in tissue perfusion. Visualization of the skin capillary bed, i.e. capillaroscopy, was recently improved by the emergence of flexible videomicroscopes easily allowing the exploration of the whole body skin surface and not only the classical site of the nailfold. The use of the method was therefore broadened from vascular acrosyndromes and connective tissue diseases to the whole spectrum of skin trophic changes of the extremities. Combination with digital image analysis systems allows the quantification of the microvascular and microlymphatic structure (quantitative appraisal of microangiopathies) and function (capillary hemodynamics and exchange). Laser-doppler and capillaroscopy can also be combined for the measurement of red blood cell velocity in single capillaries.

Capillaries↗

PubMed2000

Direct in vivo visualization of glomerular microcirculation by intravital pencil lens-probe CCD videomicroscopy.

There have been developed several types of experimental techniques for evaluation of renal microcirculation. Although each methodology possesses excellent and unique characteristics, it requires substantial artificial manipulation that might alter the renal microvascular responsiveness. To circumvent such limitations of previous ex vivo or in vitro approaches to glomerular microcirculation, we have developed a pencil lens probe CCD intravital videomicroscopic system that allows us to evaluate both systemic hemodynamics and renal microcirculation. Furthermore, real time images of afferent and efferent arterioles as well as glomeruli can be continuously assessed, which would facilitate the functional characterization of these microvessels in vivo. Finally, the tapered nature of the CCD probe of this videomicroscopy may allow direct observation of the renal microvasculature in small animals. In conclusion, this novel technique is a valuable tool for unveiling the in vivo, in situ, and intact renal microvascular behavior, and may provide further approaches to the understanding of renal microcirculation.

Animals↗

PubMed2000

[Physiopathological mechanisms of reduced skin capillary resistance in disorders of microcirculation].

Nesteroffs method is a very simple and effective for diagnosis skin capillary resistance, this method is not only effective for diagnosis, but it is very applicable for curing effectiveness control. Women's skim blood vessel conditions were investigated. Only the women of before climacteric period were invavend, all of them had microcirculation which reduced elastins of skin. Reduction of capillary resistance is closely connected with the degree of microcirculation distonia and connected with it skin elastans reduction. We can take into consideration that the changings found are connected with the changings of blood vessel microcirculation. Microcirculation distomia causes the changings of skin elastins.

Adult↗

PubMed2000

[The change of intestinal microcirculation blood flow and its relationship with bacterial translocation in burned rats receiving delayed fluid resuscitation].

OBJECTIVE: To investigate the change of intestinal microcirculation blood flow and its relationship with bacterial translocation in burned rats receiving delayed fluid resuscitation. METHODS: Twenty-four Wistar rats inflicted by 30% TBSA III degree followed by delayed fluid resuscitation were taken as the model. The rats were randomly divided into four groups, i.e. burn shock without resuscitation (BSNR), delayed resuscitation (fluid given from 8 hours postburn, DR), immediate resuscitation (IR), and sham operation (SO). The incidence of bacterial translocation, intestinal microcirculation blood flow volume of intestinal wall at terminal ileum as well as the change of systemic mean arterial pressure were monitored. RESULTS: The incidence of bacterial translocation in DR group (54.2%) was significantly higher than that in IR group (P < 0.01), but no remarkable difference with that in BS group (P < 0.05). In addition, microcirculation blood flow of intestinal wall recovered to some degree at 4 hours after delayed fluid resuscitation but far below that in IR group at the same time point. Nevertheless, the systemic mean arterial blood pressure had restored to the normal range at that time. CONCLUSION: The incidence of intestinal bacterial translocation sustained at high level after burn shock with delayed fluid resuscitation, which might be the result of delayed improvement of microcirculation blood flow of the intestinal wall.

Animals↗

PubMed2002

[Status of microcirculation and cardiodynamics in ischemic heart disease patients with decreased left ventricular fraction and their response to carvedilol].

AIM: Assessment of microcirculation in IHD patients at preclinical stage or in those with initial symptoms of cardiac failure, clarification of relationship between parameters of microcirculation and cardiodynamics. MATERIAL AND METHODS: A blind cross-over trial was made to compare skin microcirculation and cardiodynamic parameters in response to a short carvedilol course and beta-blocker anaprilin in 40 patients with ischemic heart disease with angina of effort (NYHA class I-IV, ejection fraction under 45%). RESULTS: IHD with initial symptoms of cardiac failure had a congestion-spastic type of microcirculation defect. Microcirculatory picture and cardiodynamics were related. CONCLUSION: Compared to anaprilin therapy, treatment with carvedilol enhanced capillary blood flow and improved cardiodynamics.

Carbazoles↗

PubMed2000

[The influence of serotonin on cochlear microcirculation].

OBJECTIVE: The present study was undertaken to investigate the influence of serotonin (5-HT) on cochlear microcirculation. METHOD: 2 microliters 0.5% 5-HT were applied to round window membrane in anaesthetized guinea pigs. The three parameters as blood flow (CBF), number of blood cell moving (CMBC) and blood velocity (Veloc) of cochlear microcirculation were measured with laser doppler flowmeter. The mean arterial pressure (MABP) was recorded simultaneously. RESULT: 5-HT induced a biphasic response of reduction in cochlear blood flow. In the first phase, cochlear microcirculation showed a transient abruptly reduction. The CBF, CMBC and Veloc reached to 86.8%, 90.2% and 96.3% of the baseline respectively. The second phase reduced slowly. The CBF and CMBC decreased to 89.7% and 89.6% by average throughout the experiment period respectively. The Veloc and MABP had no significant changes. CONCLUSION: 5-HT could decrease the cochlear, blood flow and result in cochlear microcirculation dysfunction.

Animals↗

PubMed1999

Changes of nailfold microcirculation in patients of type II diabetes mellitus with diabetic retinopathy.

OBJECTIVE: To study the changes of microcirculation in patients with diabetic retinopathy (DR). METHODS: Examination were performed in 153 cases of type I diabetes mellitus, among them, 72 cases were male, 81 cases were female, mean age 57.0+/-10.0 years, mean disease course 8.2+/-7.5 years. All cases were examined fundi by ophthalmologist, urinary albumin excretion rate (UAE) in 24 hours was measured by radioimmunoassay. Moreover, we examined the blood glucose, blood pressure, blood viscosity and observed the changes of naifold microcirculation. RESULTS: It was found that there were more evident disturbance of microcirculation, markedly slowed velocity of blood flow (P<0.05), significantly increased aggregation of blood cells (P<0.05) and exudation around the loop (P<0.05) in the group with DR, compared with the group without DR. CONCLUSION: It was more evident disturbance of nailfold microcirculation in patients with diabetic retinopathy.

Adult↗

PubMed1998

[Protective effect of glutamine on microcirculation of the intestine in experimental colitis].

Parenteral glutamine application can stabilize intestinal permeability and mucosal integrity. It is not known whether glutamine influences the microcirculation in the large intestine. This study thus employs intravital microscopy to investigate mucosal microcirculation in the ascending and descending Colon of Sprague-Dawley rats with TNBS colitis. The animals were randomized and treated with either saline solution (placebo) or glutamine (verum). In the severely inflamed descending colon, TNBS colitis involves a significant capillary blood flow reduction that is not improved by glutamine application. Though the ascending colon shows only a mild inflammatory reaction, its microcirculation is likewise significantly reduced. Here glutamine therapy is associated with an increase in capillary blood flow, indicating that it has a protective effect on the microcirculation of the secondarily involved intestinal segment.

Animals↗

PubMed2004

[The state of microcirculation during use of long acting metoprolol].

The aim of the study was to assess the effect of prolonged action metoprolol on the microcirculation in patients with essential hypertension (EH). We studied 51 patients with EH aged 53,4+/-4,5 years. After 7-10 days of "wash-out" period and after 8 weeks of prolonged action metoprolol (betaloc ZOK) the state of microcirculation was investigated with the use of laser Doppler flux-metry (LDF). We found significant decrease in basically enlarged basal blood flow and the level of sympathetic activity, increase in the amplitude of cardiodependent waves, normalization of basal blood flow decrement in postural test, increase in capillary blood flow reserve in patients with stage I-II EH. We failed to observe any significant changes in the microcirculatory parameters in patients with stage III EH. Treatment with prolonged action metoprolol led to increase in the number of patients with normocirculatory type of microcirculation primarily due to the decrease in the prevalence of hyperemic type. We conclude that prolonged action metoprolol does not alter microcirculation in patients with EF. Moreover, at the early stages of EH it improves the functional state of peripheral hemodynamics due to suppression of sympathetic activity.

Hemodynamics↗

PubMedDate not supplied

Smoking habit and labial microcirculation.

Smoking habit is an important risk factor in oral diseases. In the last years, many studies tried to evaluate smoking effects on the microcirculation. It had never been used such a simple not invasive technique, like the video-capillaroscopic one. The aim of the research is to analyse "in vivo", the microcirculation labial characteristics, and to evaluate the smoking effects by means of computerised videocapillaroscopy techniques. 35 healthy no-smoker patients and 35 healthy smoker patients were examined. The characteristics of the microcirculation in the areas of labial mucous were examined using computerised videomicroscopic techniques. For each patient we evaluated the visibility, the course, the tortuosity and any images characteristic of capillary loops, besides the possible presence of microhaemorrhages, the average calibre of capillary loops and the number of capillary loops visible per square millimetre. The investigation was non invasive and repeatable for each patient. In both groups the investigation of labial mucous revealed a course of capillary loops parallel to the surface. In smoker patients, it was possible to underline capillaries of a smaller calibre (P<.001), and a higher number of detectable capillaries compared with no-smoker patients (P<.001). We observed an important correlation between the capillary tortuosity and the smoking habit (P<.001). Our research highlighted, that today it is possible to carry out a capillaroscopic investigation of labial mucous in a simple and reliable way. Furthermore, smoking habit represents a real risk factor of oral disease, greatly affecting the microcirculation.

Adult↗

PubMed2002

[Microcirculation evaluation of the maxillary sinus mucosa in patients with chronic sinusitis].

OBJECTIVE: To evaluate the microcirculation change in the maxillary sinus mucosa of patients with chronic sinusitis. METHOD: The microcirculation blood flow in the maxillary sinus mucosa of 20 patients with chronic sinusitis and 10 healthy controls was evaluated by means of nasal endoscopy-guided laser Doppler flowmetry. RESULT: The microcirculation blood flow were significantly reduced in the maxillary sinus mucosa of patients with chronic sinusitis (including type I and type II) compared with healthy controls(P<0.05, P<0.01). There were no significantly difference between the two types of chronic sinusitis. CONCLUSION: The microcirculation blood flow were reduced in the maxillary sinus mucosa of patients with chronic sinusitis.

Adult↗

PubMed2005

An analysis of frequency response for the blood flow of volume pulse in microcirculation.

In this paper, a frequency analysis for the microcirculation model is introduced to find new microcirculation parameters in the frequency domain. By using Bode Plot of transfer function, we found two characteristic parameters of the model: damping ratio xi and break frequency omega(n). By analyzing the variation of xi and omega(n), it enables us to have better understanding of different states of microcirculation. At low damping, 0 or =1, the state of microcirculation will be worse and worse along with the descending of the omega(n). The results of experiments on 120 subjects are consistent with the analytical results of the model.

Analysis of Variance↗

PubMed2006

[An animal model of venous congested flap for long-term microcirculation study].

OBJECTIVE: To set up a venous congested flap model to study the mechanism of necrosis through long-term microcirculation observation. METHODS: A specially deviced chamber was assembled to one side of the ears in an adult white rabbit, about 7 approximately 10 days after the operation the congested flap model was made and the microcirculatory status of the flap was dynamically observed under a vivo-microscope for a long time. RESULTS: The venous crisis phenomenon of flap was well studied and the microcirculation of the flap was observed carefully, finally the variational rule of the congestion flap microcirculation was made clear. CONCLUSIONS: The model could well simulate the venous crisis flap in clinic, and the microcirculation could also be observed for a long time.

Animals↗

PubMed1991

Prostanoid antagonists inhibit the response of the microcirculation to "early" photodynamic therapy.

Microcirculatory shutdown appears to be of central importance in the mechanisms of action of photodynamic therapy (PDT). Traditionally 24-48 h are allowed between the administration of the photosensitizer and light to allow for tumor localization. However, previous studies have shown that the effects of PDT on the microcirculation are maximal soon after administration of the photosensitizer when serum levels are highest. This study involved the use of television video microscopy of the cremaster muscle microcirculation of male Sprague-Dawley rats to study the involvement of prostanoids in the effects of PDT on the microcirculation 30 min after administration of photofrin II. Pretreatment with topical indomethacin resulted in an altered response to PDT with arteriolar dilation and delay in vessel shutdown. The thromboxane A2 antagonist SQ29548 (100 mg/kg/min iv) resulted in a significant delay in platelet thrombus formation in arterioles and venules. These results indicate that prostanoids are involved in the mediation of the response of the normal microcirculation to PDT.

Animals↗

PubMed1991

[Serial study on nail fold microcirculation in patients with acute myocardial infarction].

The nail fold microcirculation was studied in 55 patients with acute myocardial infarction (AMI). At 12, 24, 36, 48, 60 hours and 3, 5, 7, 10, 14, 21, 28 days after AMI, sixteen indices of nail fold microcirculation were observed and analysed according to Tian Niu's "Multiple Weighted Evaluation Method of Nail Fold Microcirculation" using microscopic video system. The results showed: (1) The nail fold microcirculatory multiple weighted values were 6.6 +/- 0.8 within 12 hours after AMI, the mean value decreased significantly while the patient got better (P less than 0.0005). Significant difference among the different weighted values after AMI was shown. (2) The multiple weighted values in patients with complication were higher than those without complications (P less than 0.001). The values in patients with cardiogenic shock were much higher than those with cardiac failure or arrhythmia (P less than 0.01, P less than 0.05). (3) The weighted values in patients with multiple infarction were significantly higher than those with single infarction (P less than 0.05). (4) The nail fold multiple weighted values positively correlated with CPK, LDH, GOT (r = +0.82-0.97, P less than 0.0005) respectively. Thus, the higher the weighted value the much more serious condition of patients with AMI was. Continuous nail fold microcirculation observation and electrocardiographic monitoring would be helpful in early diagnosis and treatment of the complications with AMI to reduce the total mortality.

Aged↗

PubMed1990

[Microcirculation in the subcutaneous layer and in muscles in diabetes mellitus].

The work is focused on the possibility of early diagnosis of diabetic microangiopathy. The authors used examination of microcirculation by the method of tissue clearance of Na 131I. In a group of 106 patients with diabetes thus the microcirculation of the lower extremities in the subcutaneous layer and the calf muscle was examined. A group of 36 healthy subjects served as control. An altered microcirculation was found in 75% type 1 diabetics and in all type 2 diabetics. In those with an altered microcirculation only in 23% type 1 diabetics and in 17% type 2 diabetics organ manifestations of diabetic microangiopathy (i.e. retinopathy and nephropathy) were lacking. It seems thus that altered Na 131I absorption in the lower extremities is an earlier sign of microangiopathic affection than identifiable organ changes. Examination of tissue clearance of Na 131I thus could reveal in time individuals threatened by this complication of diabetes.

Adult↗