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At least 865 records · Page 48Linked to original sources
PubMed1990

[Relations of the duration of pre-existing angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction].

The aim of this retrospective study was to determine the relationship between the duration of preceding angina pectoris, collateral circulation and left ventricular function after isolated coronary occlusion with or without myocardial infarction. Coronary angiography of 138 consecutive patients showed isolated and complete occlusions of the left anterior descending (58 patients) or right coronary artery (80 patients). One hundred and four patients had myocardial infarction with (Group A, n = 21) or without (Group B, n = 83) preceding angina pectoris and 34 had angina without myocardial infarction (Group C). The left ventricular ejection fraction was measured by ventriculography in the 30 degrees right anterior oblique projection. The collateral circulation was assessed by coronary angiography and evaluated as follows: no flow or flow limited to collateral branches (subgroup 1) and partial or complete filling of the epicardial arterial segment (subgroup 2). In the global population the left ventricular ejection fraction was higher and the duration of preceding angina pectoris was longer in the subgroups with a well developed collateral circulation. There was no difference in ejection fraction between Groups A and B (presence of myocardial infarction), on the other hand, within each of the groups, a good collateral circulation (subgroup 2) was associated with a significantly higher ejection fraction. Group C (without infarction) patients had better ejection fractions than Groups A or B, especially when the collateral circulation was poorly developed. Within Group C, the quality of the collateral circulation did not seem to affect the ejection fraction. The left ventricular ejection fraction is lower in patients with isolated coronary occlusion and myocardial infarction.(ABSTRACT TRUNCATED AT 250 WORDS)

Angina Pectoris↗
PubMed1975

Adrenergic mechanisms in the cephalic and cerebral circulations of the subhuman primate.

Effects of circulating adrenergic amines on the cerebral circulation remain contraversial. Common carotid (CCF) and internal carotid (ICF) arterial flows were determined electromagnetically in eight lightly anesthetized baboons to evaluate alterations in the cephalic and cerebral vascular beds, respectively. Epinephrine (E), norepinephrine (NE), phenylephrine (PE), and isoproterenol (I) were injected randomly in doses of 10-3, 10-2, 10-1, and 1 mug (base) per kilogram into each carotid artery. Measurements were repeated in four animals after alpha-adrenergic blockade with phenoxybenzamine and in another four animals after beta-adrenergic blockade with propranolol. Baseline CCF was 75 plus or minus 10 (S.E.M.) ml. per minute and ICF was 58 plus or minus 8 ml. per minute. Significant (p smaller than 0.05) CCF changes without arterial pressure alterations occurred with 10-1 mug per kilogram doses. Alpha blockade significantly (p smaller than 0.05) attenuated the effects of E, NE, and PE on CCF while beta blockade significantly (p smaller than 0.05) attenuated the effect of I on CCF. ICF did not change significantly (p greater than 0.05) after injection of any of the vasoactive amines, unless associated with pressure changes at the highest dose. Our data suggest the presence of alpha- and beta-adrenergic receptor sites within the cephalic circulation resulting in significant flow responses to intra-arterial adrenergic amines. The absence of responses in the cerebral circulation suggests that circulating catecholamines do not significantly influence or regulate the cerebral vasculature. In addition the data suggest that use of adrenergic agonists to alter the hemodynamics of the cerebral circulation is limited.

Adrenergic Agonists↗
PubMed1988

Circulating malignant cells in non-Hodgkin's lymphoma: correlation with binding by peanut agglutinin.

A significant number of patients with non-Hodgkin's lymphoma have peripheral blood involvement during the course of their disease. Because the expression of receptor for the lectin peanut agglutinin PNA by normal lymphocytes is associated with noncirculating (stationary phase) cells, we studied the relationship between PNA binding by lymphoma cells and the presence of clonal B cells in the blood of 38 patients with B-cell lymphoma. The binding of PNA by cells in tissues was determined by the immunoperoxidase method and by two-color flow cytometry. Circulating lymphoma cells (clonal B cells) were identified by a sensitive flow-cytometric technique (kappa-lambda analysis) and were also studied for PNA binding in some cases. In all, 16 of 38 (42%) of lymphomas were PNA+, including a spectrum of histologic types. Circulating lymphoma cells were demonstrated in 17 of 22 PNA-lymphomas, whereas only 3 of 16 of PNA+ lymphomas had such circulating cells. Thus, there is a significant association between PNA binding and peripheral blood involvement by lymphoma (P less than .005 by chi-square analysis). In 12 cases, the circulating and tissue lymphoma cells had similar expression of PNA receptor (2 PNA+ and 10 PNA- cases), indicating that modulation of the PNA binding sites did not occur. In three patients who presented with lymphosarcoma cell leukemia, the circulating malignant cells were PNA-. These findings suggest that for both normal and malignant lymphocytes the absence of binding sites for PNA is associated with the capacity of these cells to circulate freely.

Binding Sites↗
PubMed1987

Central and coronary circulation of the normal man during orthostatic and lower body negative pressure tests.

The effects of the tilt test (at 60-70 degrees for 20 min) and LBNP test (at -30 and -60 mm Hg for 20 min each) on the basic parameters of central circulation (15 test subjects) and coronary circulation (11 test subjects) were investigated. The study was performed using thermistor-equipped catheters implanted into the pulmonary artery and coronary sinus and Teflon catheters implanted into the brachial artery. In the study, the basic parameters of central circulation (pressure in the right atrium and pulmonary artery, transmural pressure in these compartments, cardiac index, stroke index, etc.) and coronary circulation (blood flow in the coronary sinus, left ventricle oxygen consumption, coronary resistance, etc.) were measured. Correlation between circulation variations and metabolic requirements was assessed (with respect to changes in acid-base equilibrium of blood). The effect of the tilt test and LBNP test on the basic parameters of central and coronary circulation, blood acid-base equilibrium and oxygenation was compared.

Acid-Base Equilibrium↗
PubMed1985

Physiology of the splanchnic circulation.

The splanchnic circulation is composed of gastric, small intestinal, colonic, pancreatic, hepatic, and splenic circulations, arranged in parallel with one another. The three major arteries that supply the splanchnic organs, cellac and superior and inferior mesenteric, give rise to smaller arteries that anastomose extensively. The circulation of some splanchnic organs is complicated by the existence of an intramural circulation. Redistribution of total blood flow between intramural vascular circuits may be as important as total blood flow. Numerous extrinsic and intrinsic factors influence the splanchnic circulation. Extrinsic factors include general hemodynamic conditions of the cardiovascular system, autonomic nervous system, and circulating neurohumoral agents. Intrinsic mechanisms include special properties of the vasculature, local metabolites, intrinsic nerves, paracrine substances, and local hormones. The existence of a multiplicity of regulatory mechanisms provides overlapping controls and restricts radical changes in tissue perfusion.

Colon↗
PubMedDate not supplied

[Pathophysiological aspects of the development of circulatory hypoxia in artificial circulation].

Metabolic status of 650 patients operated on under artificial circulation for various cardiac diseases was studied. Circulatory hypoxia was found to underlie all metabolic disorders in artificial circulation which manifest by loss of buffer bases and lactate accumulation. Development of circulatory hypoxia in artificial circulation is caused by inadequate oxygen supply to tissues due to initially present disorders of the peripheral bloodstream which augment during perfusion by circulation centralization and due to changes of blood rheology, particularly so in increase of hypothermia and prolongation of perfusion. Lactate concentration during artificial circulation is an objective criterion of tissue hypoxia which sufficiently well correlates with development of heart failure in the early postperfusion period. When correcting circulatory hypoxia during artificial circulation the anesthesiologist and perfusiologist should aim at changing the vascular tone towards an increase of the peripheral bloodflow. This is particularly important during prolonged hypothermic perfusions in patients with initially low reserve potential of the myocardium.

Cardiac Surgical Procedures↗
PubMed1976

Specific removal of bovine serum albumin (BSA) antibodies in vivo by extracorporeal circulation over BSA immobilized on nylon microcapsules.

Studies were undertaken to determine whether BSA, once immobilized on activated nylon microspheres, would be capable of specifically removing circulating BSA antibody in vitro and in vivo in an extracorporeal circulation system in dogs. Nylon microspheres were prepared and, after gentle hydrolysis and glutaraldehyde treatment, demonstrated a retention of up to 34.5 mg of BSA. In vitro studies showed that BSA immobilized on microspheres removed a significant percentage of BSA-binding activity. For in vivo studies, an extracorporeal circulation system was established and mongrel dogs were then injected with anti-BSA and anti-HSA antibodies. After an equilibration period, BSA microspheres were introduced into the extracorporeal circulation system. After the insertion of BSA microcapsules, serum exhibited a sharp reduction in BSA binding over the next 15 min, with a more gradual diminution over the ensuing 60 to 90 min. There was no significant reduction in anti-HSA binding over the same time frame. This effect could not be attributed to release of BSA from the microspheres since no 125I-BSA was detected in the serum or organs of the dogs at the conclusion of the experiments. After extracorporeal circulation over nylon microspheres, there were only minimal changes in the host's hematocrit or leukocyte counts and no significant thrombotic material or cellular debris was recoverable on the capsules. These data suggest that antigen immobilized on nylon microspheres may specifically withdraw circulating antibodies in vivo with minimal release of its antigenic material and little alteration in the host's hematologic status.

Animals↗
PubMed1995

The in vivo effect of endothelins on retinal circulation in nondiabetic and diabetic rats.

PURPOSE: The endothelins are potent vasoactive peptides. This study was performed to characterize the in vivo effects of the endothelin peptides on the retinal circulation in nondiabetic and diabetic rats. METHODS: The video fluorescein angiography methodology was used to quantitate retinal hemodynamic responses to endothelin-1 (ET-1) and endothelin-3 (ET-3) in rats. A total of 99 rats were used for these experiments. Video fluorescein angiography recordings were performed before and at different times after intravitreal injection of different concentrations of ET-1 and ET-3 in nondiabetic and diabetic rats. Vascular diameters and retinal circulation times were determined using computer-assisted image analysis of the recorded angiograms. RESULTS: The maximal response to ET-1 was observed at 15 minutes after intravitreal injection and was maintained for as long as 30 minutes after injection. Subsequent data measured at 15 minutes after intravitreal injection showed significant prolongation of retinal circulation times and retinal artery constriction. For example, at a concentration of 10(-7) M, the retinal circulation time increased by 270% +/- 121% of the baseline value. In contrast, 10(-7) M ET-3 injection showed a 52% +/- 29.5% increase in circulation time compared to baseline. In diabetic animals, 10(-7) M ET-1 injection showed a blunted response (only 26% +/- 8% of baseline) compared to the same ET-1 injected concentration in nondiabetic rats. CONCLUSIONS: The rat retinal circulation shows a pronounced retinal response to ET-1 intravitreal injection. The response to ET-3 is significantly less than it is to ET-1, and in diabetic animals there was also a significant blunting of the retinal response to ET-1. The blunted response to ET-3 is consistent with the lower affinity of retinal vessel ET-1 receptors to ET-3. The blunted ET-1 response in diabetic rats is consistent with previously reported results, demonstrating resistance to ET-1 action in retinal pericytes exposed to high glucose.

Animals↗
PubMed1994

[The effect of an extracranial occlusive lesion of the branches of the aortic arch on the status of the intracranial circulation].

Unilateral occlusion of extracranial cerebral arteries results in asymmetric intracranial flow rate against unaffected regional tissue circulation. Multiple occlusions entail reduction of intracranial circulation even in satisfactory collateral circulation. Reduction of tissue cerebral circulation occurs in well-defined occlusive processes with decompensated collateral circulation in the absence of carbogenic vascular responses. Co2 reactivity may serve a criterium of collateral circulation status and a positive prognostic sign in surgery planning.

Adolescent↗
PubMed1994

[Evaluation of angiographic delayed vasospasm due to ruptured aneurysm in comparison with cerebral circulation time measured by IA-DSA].

Delayed vasospasm due to ruptured aneurysm has been basically evaluated by angiographic changes in contrast to clinical features such as delayed ischemic neurological deficits (DIND). However, the discrepancies between angiographic and clinical findings have been pointed out. In this study, angiographic changes and cerebral circulation time in ruptured aneurysms were simultaneously investigated with IA-DSA. Thirty-two patients, who had ruptured aneurysms at the anterior circle of Willis and neck clippings at the acute stage, were investigated. Carotid angiogram was performed with IA-DSA on the 7-13th day after the attack. Angiographic changes were evaluated by Fischer's classification and circulation time was calculated in the following way. A time-density curve was obtained at the two ROI's; the C3-C4 portion and the rolandic vein. Circulation time was defined by the difference between the time showing peak optical density at the carotid and the venous portion. The control value of this circulation time obtained from 20 cases with non-rupture aneurysm and epilepsy was 3.4 sec (53 year old) on the average. X-ray CT scan examination was performed at the same time and clinical features were observed everyday. Angiographically, 3 cases were free from vasospasm, 18 cases were found to present slight to moderate vasospasm, and 11 cases showed severe vasospasm. Circulation time in patients with no spasm was 3.6 seconds, in patients with slight to moderate vasospasm it was 4.3 seconds and in patients with severe vasospasm it was 6.8 seconds. Ten patients showing cerebral infarction on CT scans demonstrated significantly long circulation time, 7.0 second on the average.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

[Significance of hetero-collateral circulation in patients with chronic occlusion of the superficial femoral artery].

The authors examined a total of 11 lower extremities in 10 patients with chronic occlusion of the superficial femoral artery (mean length of occlusion 17.2 cm) in order to compare the participation of the heterocollateral and homocollateral circulation in the maintenance of the ankle pressures assessed by the Doppler principle. Before percutaneous transluminal recanalization of the chronic occlusion of the superficial femoral artery the authors induced by means of a balloon catheter short-term occlusion of the deep femoral artery in its central portion, closely after its insertion (complete block of the heterocollateral circulation) and in the periphery of this artery (partial block of the collateral circulation). During both types of balloon occlusion the authors assessed the ankle pressures and compared them with control values, assessed before occlusion. The authors found that in their patients the heterocollateral circulation, as compared with the homocollateral one, participated substantially more in the value of the ankle pressure at rest. The importance of the heterocollateral circulation increased with the length of chronic occlusion of the superficial femoral artery. In some patients the homocollateral circulation did not participate at all in the maintenance of the ankle pressure. A drop of the ankle pressure in patients with chronic occlusion of the superficial femoral artery is also more marked in acute occlusion of the deep femoral artery in its central portion, as compared with acute occlusion in the periphery.

Aged↗
PubMed1995

Can the artificial heart make the circulation become fractal?

In order to analyze the hemodynamic parameters in prosthetic circulation as an entity and not as decomposed parts, non linear mathematical analyzing techniques, including the fractal dimension analyzing theory, were utilized. Two pneumatically actuated ventricular assist devices were implanted, as biventricular bypasses (BVB), in chronic animal experiments, using four healthy adult goats. For the comparison between the natural and prosthetic circulation in the same animals, the BVB type complete prosthetic circulation model with ventricular fibrillation, was adopted. All hemodynamic parameters with natural and prosthetic circulation were recorded under awake conditions, and calculated with a personal computer system. Using the non-linear mathematical technique, the arterial blood pressure waveform was embedded into the return map as the beat-to-beat time series data and fractal dimension analysis were performed to analyze the reconstructed attractor. By the use of the Box counting method, fractal dimension analysis of the hemodynamics was performed. Return map of the hemodynamics during natural and artificial circulation showed fractal characteristics, and fractal dimension analysis of the arterial blood pressure revealed the fact that lower dimensional fractal dynamics were evident during prosthetic circulation. Fractal time series data is suggested to have robustness and error resistance, thus our results suggest that the circulatory regulatory system with an artificial heart may have these desired characteristics.

Animals↗
PubMed1997

[Molecular diagnostic detection of circulating tumor cells and their prognostic implications].

While not all circulating tumor cells survive, one could postulate that patients with circulating tumor cells might be candidates for adjuvant chemotherapy because of the risk of relapse. Recently, reverse transcriptase-polymerase chain reaction (RT-PCR) for the detection of circulating tumor cells has been suggested as a potential technique for staging of cancer. In malignant melanoma, the detection of circulating melanoma cells by tyrosinase RT-PCR correlated with the clinical stage of patients and was an independent prognostic factor for recurrence. A strong association was found between the detection of neuroblastoma cells in circulation by tyrosine hydroxylase RT-PCR with bone marrow micrometastasis. This method may be of use to identify early signs of relapse in disease-free patients. In prostatic cancer, the frequency of positivity for detection of circulating tumor cells in peripheral blood by PSA RT-PCR increased with tumor stages but a significant proportion of patients with metastatic disease were negative. The prognostic significance of the detection of tumor cell in blood in other epithelial tumors is not established and will require further long-term follow-up study.

Biomarkers, Tumor↗
PubMed1997

[Observing and nursing of the blood circulation for the free flap].

The monitoring for the blood circulation of the free flap should be continued in postoperation. If the crisis of blood circulation occur, the monitoring for the blood circulation is the key to keep the success for the grafted flap, because the majority of the crisis of the free flap can be corrected based on the early discovering and corrective judgment. In our 11 cases, the filling of blood circulation of the free flap was difficulty to be monitored because of the pigmentation or other reason. We combined some special monitor methods to judge the blood circulation of the flap, the corrective judgment rate was 100 percent in our group. We concluded that the combined some methods for monitoring can judge the blood circulation of the flap correctly.

Blood Circulation↗
PubMed1998

[Role of academic B.V. Petrovskiĭ in the development of extracorporeal circulation].

The paper shows the role of Academician B.V. Petrovsky and his scientific school in the development of extracorporeal circulation, as well as his ties with S.S. Bryukhonenko (1890-1960), the founder of extracorporeal circulation in Russia. Heart-lung apparatuses were designed with the participation of collaborators of the Surgery Research Center (SRC), Russian Academy of Medical Sciences. A short account is given of the principal aspects of extracorporeal circulation, which have been studied at the SRC, such as protective blood flow distribution, centralization of circulation, the optimal perfusion rate, criteria for adequate extracorporeal circulation, control of blood coagulation and acid-base state, blood concentration, extracorporeal circulation with autooxygenation, hyperbaric perfusion, normothermal perfusion with continuous warm blood cardioplegia).

Extracorporeal Circulation↗
PubMedDate not supplied

[The regional hemodynamic characteristics of subjects with different types of blood circulation].

The group of 56 young healthy men was divided into three subgroups according to the cardiac output values: hypo-, eu- and hyperkinetic types of circulation. Regional hemodynamics was studied in the head, lungs and shin by means of rheoplethysmographic technique. It has been shown that pulse blood filling of the vessels of all the regions studied significantly depends on the type of circulation. In persons with hyperkinetic type of circulation the pulse blood filling was more expressed than in those with hypokinetic type. The analysis of the tone of large and middle vessels of the lungs and shin has demonstrated opposite relations. The tone of head vessels reveals no correlation with the types of circulation. This fact may be explained by existence of pronounced autoregulation of the brain circulation.

Adult↗
PubMed1997

Relationship between circulating secretory immunoglobulin A levels and portal blood cytokine levels during major abdominal surgery.

OBJECTIVE: To investigate whether circulating secretory immunoglobulin A (S-IgA) levels correlate with cytokine and endotoxin levels in the systemic or portal circulation during major abdominal surgery. METHODS: Twenty patients who underwent abdominal surgery for malignant carcinoma were included in this prospective study. Portal blood samples were taken for the measurement of cytokine and endotoxin levels during abdominal surgery. Systemic blood samples were simultaneously collected for the determination of cytokine, endotoxin, and S-IgA levels. After surgery, serum levels of aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, and S-IgA were measured on the 1st, 7th, and 14th, postoperative days. RESULTS: Circulating S-IgA levels correlated with interleukin-6 levels (r = 0.48, P < .05), but not with interleukin-1 or endotoxin levels in the portal circulation. In the postoperative period, the best correlation between serum S-IgA and other biochemical parameters was found with alkaline phosphatase (r = 0.87, P < .01), followed by alanine aminotransferase (r = 0.70, P < .01). CONCLUSIONS: Interleukin-6 in the portal blood might stimulate synthesis and/or regurgitation from bile into the systemic circulation of S-IgA. Circulating levels of S-IgA appeared as a sensitive marker for postoperative cholestatic liver damage.

Abdominal Neoplasms↗
PubMed2004

A new quantitative method for circulating DNA level in human serum by capillary zone electrophoresis with laser-induced fluorescence detection.

We present a method for the quantification of circulating DNA in serum by capillary zone electrophoresis (CZE) with laser-induced fluorescence detection (LIF). The serum was digested by proteinase to release free DNA. SYBR Gold was utilized as DNA intercalating dye, fluorescein as internal standard (ISTD). CZE-LIF was applied for the separation and quantification of total circulating DNA. Good linearity (R = 0.9992) in the low range of DNA concentrations (0.5-40 ng/mL) and a detection limit of 0.5 ng/mL for DNA (S/N = 3) were obtained. Our data demonstrated that CZE-LIF system has a good linearity with excellent sensitivity and satisfactory reproducibility in the quantification of circulating DNA in serum. This method was successfully used for the quantification of circulating DNA levels in serum. We observed that the circulating DNA levels in certain cancer patients were significantly higher than that in healthy individuals. Compared to current methods, our protocol does not need the extraction of DNA from serum. Our preliminary results have illustrated that CZE-LIF system is simple, rapid, and sensitive, and it is well suitable for large-scale quantification of circulating DNA levels in clinical diagnosis.

Adult↗