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At least 1,531 records · Page 85Linked to original sources
PubMed1990

[Magnetic resonance angiography of the neck vessels: technique and anatomy].

The authors identified the standard projections for studying neck vessels with magnetic resonance angiography. Sixty volunteers underwent angio-MR of the arterial neck vessels with FISP 3D FT sequences obtained on the coronal and sagittal planes. The gradient-echo sequence (FISP 3D FT) was acquired with TR = 0.04-0.08 s and TE = 15 ms, with 25 degrees flip angle. Single excitated slices of thickness ranging from 1-2 mm were included in the acquisition volume. These sequences were subsequently processed by the maximum intensity projection method. Two radiologists examined our results to choose the optimal projections. We used a semiquantitative scale which allowed us to distinguish 3 different diagnostic levels for each projection: well-visualized vessels, poorly-visualized, and non-visualized ones. For each section axial rotations were performed ranging from 0 degree to 180 degrees, with 15 degrees intervals. On the coronal plane, rotations from -45 degrees to 45 degrees were the optimal ones to visualize the studied vessels. The 0 degree-15 degrees-30 degrees-45 degrees-135 degrees-165 degrees-180 degrees projections allowed the common carotids to be clearly demonstrated together with the vertebral arteries. The other projections appeared to be useless for diagnostic purposes. On the sagittal plane, rotations from 60 degrees to 120 degrees were the optimal ones. The 90 degrees projection allowed the demonstration of all the big arterial vessels of the neck, including carotid bifurcation and internal and external carotids. The assessment of the optimal diagnostic projections for angio-MR of the neck vessels is helpful to reduce post-processing time. As a matter of fact, the immediate visualization, during the examination, of the standard projections allows further acquisitions to be obtained--if needed--to try to solve specific diagnostic doubts.

Adult↗
PubMed1990

The effect of anesthesia and surgery on diaphragmatic lymph vessel flow after endotoxin in sheep.

Increases in diaphragmatic lymph vessel flow (Qdi) may be important in preventing ascites because diaphragmatic lymph vessels drain the peritoneal space. However, lymphatic vessel function may be depressed in anesthetized, open chested animals. To test this hypothesis, we cannulated diaphragmatic lymph vessels in five sheep which were anesthetized with 1-2% halothane. We performed a thoracotomy and cannulated a diaphragmatic lymph vessel in each sheep. Then we infused 0.75-1.0 micrograms/kg of E. coli endotoxin intravenously and we measured Qdi and the lymph protein concentration for 2-4 hrs. The data were compared to previously reported data for five unanesthetized sheep (J. Appl. Physiol. 62:706-710, 1987). At baseline Qdi = 0.8 +/- 0.7 (SD) in the anesthetized sheep and 1.0 +/- 0.8 ml/hr in the unanesthetized sheep. After endotoxin, Qdi increased to 4.5 +/- 3.1 ml/hr in the unanesthetized sheep (p less than 0.05) but Qdi did not change in the anesthetized sheep. However, the lymph protein concentration increased similarly in each group, indicating that endotoxin caused the same degree of injury in each group. Our results indicate that diaphragmatic lymph vessel function is depressed in anesthetized, open chested sheep.

Analysis of Variance↗
PubMed1990

[The diagnostic importance of echography of the spleen, abdominal lymph nodes and vessels in chronic lympho- and myeloleukemias].

Echography of the spleen and abdominal vessels was performed in patients with chronic myeloleukemia (CML) and chronic lympholeukemia (CLL). The patients belonging to these groups manifested enlargement of the spleen, alterations of its echo structure and dilatation of the vessels even at the initial disease stage. Appreciable splenomegaly with a proportional increase of the diameter of the main vessels of the abdominal cavity and derangement of the splenic echo structure were ascertained in patients in the stage of pronounced clinicohematological manifestations. Moreover, provided those diseases run an atypical course, echography of the spleen, abdominal lymph nodes and vessels is of differential diagnostic importance. As compared to patients with CLL, the spleen of those with CML differed as regards the extent of enlargement and alterations in the organ structure in different stages of the tumorous process. There were differences in the diameter of the abdominal vessels. The patients with CML demonstrated splenic infarctions of different standing whereas patients with CLL conglomerates of the abdominal lymph nodes. In patients with CML, remarkable splenomegaly was observed more frequently. Echography of the spleen and vessels in patients with CML and CLL is a highly informative, noninvasive and safe method which is likely to be widely used in hematology.

Abdomen↗
PubMed1990

Morphologic features of lymph vessels in caprine hemal nodes.

The distribution and characteristics of lymph vessels in caprine hemal nodes were studied after glutaraldehyde fixation and epoxy resin embedding. Histologically, the lymph vessels were characterized by thin walls and wide lumens containing inspissated lymph in which a few cells were suspended. The lymph vessels contrasted sharply with adjacent blood sinuses that were filled with elements of circulating blood. A circumferential lymph vessel in the cortex joined radial branches in the medulla that met at the hilum to drain through a large efferent lymph channel. Ultrastructurally, the lymph vessel wall comprised endothelial cells supported by a continuous basal lamina, collagen fibrils, and adventitial reticular cells. The cytoplasm of endothelial cells had fenestrations, plasmalemma-associated vesicles, vacuoles, and focal splits that enclosed large compartments. Many compartments contained erythrocytes and lymphocytes. Modifications of the endothelial cells signified their endowment with features that favored transendothelial transport. The distribution of lymph vessels and the finding of only efferent lymph channels are related to the roles of hemal nodes in blood storage by hemoconcentration and in immune defense mechanisms.

Animals↗
PubMed1988

Identification and characterization of the blood vessels of solid tumors that are leaky to circulating macromolecules.

The tumor microvasculature is hyperpermeable to plasma proteins, but the specific vessels that leak have not been identified. To investigate this question, the extravasation of circulating tracers of varying size was studied by fluorescence, light, and electron microscopy in animals bearing solid transplantable carcinomas. In all five tumors studied, 70 and 150 kD fluoresceinated (FITC)-dextrans and colloidal carbon leaked extensively from the prominent vascular plexus that was induced around individual tumor nodules and at the tumor-host interface. Leaky vessels were mature veins or venules, lined by a continuous endothelium; most had closed interendothelial cell junctions. Immature interface vessels and tumor-penetrating vessels did not leak these macromolecular tracers significantly. Three kD of FITC-dextran leaked from peripherally situated tumor veins or venules but also extravasated from tumor-penetrating vessels and capillaries supplying normal tissues. These data correlate the functional and anatomic heterogeneity of tumor vessels and provide a rationale for the distribution of circulating molecules such as monoclonal antibodies and tumoricidal drugs in solid tumors.

Animals↗
PubMedDate not supplied

[Aging changes in conjunctival blood vessels].

The relation of the changes in the conjunctival blood vessels to the age were studied in a group of 217 persons aged 20 to 79 years. All persons suffering from arterial hypertension, diabetes, systemic diseases and manifested forms of arteriosclerosis were excluded. It has been proved that examination of the conjunctival blood vessels by means of the slot-lamp facilitates the study of the changes in the microscopic blood vessels in relation to the age. Most conspicuous was the increase of the meander course of the blood vessels, also the increasing number of blood vessels is more frequent in the group of older persons. Clusters of vessels and a narrowing of the diameter of the arterioles was seen only in persons over fifty years of age. The "upright" course of the arterioles was found only in individual cases and without any special dependence to age. Sacculations on the small veins and microaneurysms on the arterioles were not observed in any of the examined group of healthy persons.

Adult↗
PubMed1989

[Blood supply of the main vessels in laboratory rats and rabbits].

The vascular bed in 25 rabbits and 25 white rats has been revealed by means of vital injection of Indian ink into the intraorganic vessels, staining of erythrocytes (benzidine reaction) and silver impregnation. In preparations of the aorta, inferior and superior vena cava diameter of the vessels, the wall and middle membrane thickness, amount of elastic membranes have been measured. Ramification of small vessels and capillaries are revealed only in the paravasal tissues, surrounding the aorta and veins. In serial sections it has been stated that at their greatest extent vasa vasorum has no walls and only in places, where the intercostal (or others) vessels get out of the aorta in its middle or external tunics, a limited, as to its spread, network of intramural vessels exists. The morphometrical analysis does not show any regular connection between the vascular diameter, wall thickness, or middle membrane thickness, amount of elastic membranes in it with presence or peculiarities in distribution of the intramural vessels.

Animals↗
PubMedDate not supplied

High-flow angiopathy: cerebral blood vessel changes in experimental chronic arteriovenous fistula.

Profound vascular damage secondary to high-flow extracranial states has been well characterized. However, changes in cerebral vasculature secondary to high-flow states have not been studied. To determine changes related to high-flow states in cerebral vessels, a rabbit model was developed in which torrential flow was created in the vertebrals, carotids, basilar, and vessels of the circle of Willis by means of a carotid-jugular shunt after ligation of the proximal carotid. The clinical, angiographic, and histologic changes noted in the animal model include: abrupt clinical deterioration after a variable interval with some animals developing ptosis, afferent vessel dilatation and the development of prominent anastomotic channels, variable cerebral vessel histopathology--related to duration and relative proximity to the shunt--affecting all three vessel layers, plump, irregular, and clumped endothelium, denuded with adherent platelets, irregular, duplicated, and thinned internal elastic membrane, frayed with invasion of the intima by mesenchymal cells, vacuolization and necrosis of the media muscle, and invasion of adventitia by foreign cells and small blood vessels. The high-flow angiopathy seen in this model may help explain vascular changes associated with high-flow cerebral vascular lesions, as well as other types of vascular damage.

Animals↗
PubMed1988

Pattern of blood vessels in forelimbs of three strains of mice.

A technique was developed for visualizing the pattern of arteries in the adult mouse forelimb. The aorta was cannulated and injected with blue stained Batson's Number 17 Anatomic Compound to perfuse the forelimb arteries; the ossified skeleton was stained and the soft tissues were cleared, making it possible to examine the entire arterial system in the intact specimen. The pattern of distribution of arteries were compared in 120 forelimbs from three strains of mice, two inbred and one hybrid. Significant differences between the three strains were found for 9 of 16 variations evaluated. Differences in the point of origin of vessels were the most common; differences in the fusion of vessels, the extension of vessels and the presence of extra vessels were also identified. The patterns were much more constant in the two inbred strains than in the hybrid strain, suggesting the importance of genetic factors in determining the arterial pattern. Absence of major vessels and an abnormal persistence of embryonic vessels, which have been observed in association with skeletal malformations, were not observed in any of the 120 normal adult mouse forelimbs examined.

Animals↗
PubMed1988

[Spatial orientation of the structures of the ventral surface of the medulla oblongata to the vessels of the crus and small intestine].

In acute experiments of 22 cats with simultaneous perfusion of the crus and small intestine's vessels, the neurocytes affecting the neurogenic tone of the vessels were found 2 mm caudal of the middle of exposure of the n. n. hypoglossi roots and 6 mm rostral of this level, the depth being 1000-2000-3000 mu ventral of the medulla oblongata surface. Cerebral structures situated at the level of the middle of exposure of the n. n. hypoglossi roots, 2-4-6 mm rostral of this level, at the depth 1000-2000-3000 mu and stimulation of which increases regional vascular resistance, are called pressor ones. Electrical activity of the neurocytes situated 2 mm caudal of the middle of exposure of the n. n. hypoglossi roots, at the depth 1000-2000-3000 mu, mostly decreases neurogenic tone of the organ vessels (depressor area). Proportional dependence of the vasoconstrictor response of the vessels on the stimulation intensity was only found in activation of neurons in the points of pressor area. A greater increase (1.5-fold) of perfusion pressure in the crus vessels as compared with the small intestine's those in stimulation of comparable points of the pressor area suggests different density of distribution of the neurons affecting neurogenic tone of the crus and small intestine's vessels.

Animals↗
PubMed1987

Influence of vessel involvement and early streptokinase therapy on regional and global left ventricular function in acute myocardial infarction.

150 consecutive patients with acute myocardial infarction received 750,000 units of intravenous streptokinase within four hours of pain onset. Angiography was performed on day 6, from which ejection fraction (EF), infarct-related ejection fraction (IREF), and non-infarct related ejection fraction (NREF) were calculated. 50% stenosis was considered to be significant. The streptokinase patients with patent infarct-related arteries who had no evidence of previous myocardial infarction were compared with 82 conventionally treated (without streptokinase) patients who had no evidence of previous myocardial infarction. Sub-group analysis based on vessel involvement, usage and timing of streptokinase was done. Streptokinase was associated with better left ventricular function in all sub-groups if given less than 2 hours after pain onset. In inferior myocardial infarction, streptokinase patients with single-vessel disease had normal EF (67 +/- 8), compared to significantly depressed EF in multi-vessel disease (56 +/- 12, p less than 0.05). This difference is accounted for more by the NREF than the IREF. In anterior infarction, patients with single-vessel disease did only slightly better than multi-vessel disease. In multi- and single-vessel anterior infarction, preservation of function by streptokinase appears to be due to the compensatory ability of the non-infarcted region as well as the residual function of the infarct-related region. region.

Cardiac Output↗
PubMedDate not supplied

Intravenous DSA and duplex sonography as screening examinations for carotid disease: comparison in 102 vessels.

Duplex sonography and intravenous digital subtraction angiography (DSA) were compared in 102 carotid bifurcations in 51 patients. Sonograms were adequate in 87 (85%) vessels and angiograms were adequate on at least one view in 86 (84%) vessels. An adequate image was obtained by one or the other method in all but two vessels (98%). Although most vessels were seen well on one view only on DSA, agreement with sonography was exact in 73% of compared vessels and acceptable in 96%. Furthermore, no difference was found in the rate of agreement with sonography for vessels seen well by DSA on two or more views compared with those seen well on one view only. It was concluded that DSA and sonography are comparable screening methods for carotid disease and that a suboptimal study by either can usually be compensated for by performance of the other.

Carotid Artery Diseases↗
PubMed1979

Vascular substances that modulate blood-to-vessel interactions.

The vessel wall contains powerful inhibitors of thrombogenesis. One substance, a proteoglycan, is a strong anticoagulant but has only a limited effect on platelet aggregation. It prolongs the thrombin clotting time and partial thromboplastin time, but only blocks platelet aggregation induced by thrombin. Another vessel wall constituent, a prostaglandin derivative (prostacyclin), is a potent inhibitor of platelet aggregation. It antagonizes platelet aggregation induced by a variety of agents including adenosine diphosphate, collagen, arachidonic acid and thrombin; however, its only effect on coagulation is through the inhibition of platelet factor-3 release. Proteoglycans and prostacyclin comlement each other's antithrombotic activities, and together serve to limit the hemostatic response of blood to vessel wall injury. Vessels devoid of the intima continue to produce prostacyclin. Prostacyclin produced by these vessels is probably more important than that produced by vessels with the intima in the prevention of thrombus deposition.

Animals↗
PubMed1985

[Arterial vascularization of the tail of the pancreas with special reference to the relation of the tail and body vessels].

The cauda pancreatis has a characteristic pattern of vascularization. Among the big arterial stems surrounding it, up to 4 arteries, 'caudal arteries', nourish the arterial system of the cauda. These stems originate especially in the Arteria gastroepiploica sinistra and in the lower main splenic branch of the Arteria lienalis. The vascular relations between corpus and cauda can be of different kinds. Five basic types of relations can be identified: type I: the cauda is supplied exclusively by caudal arteries; type II: at least one caudal artery anastomoses with the vessels of the corpus; type III: the cauda is supplied both by the caudal arteries and by vessels of the corpus (non-anastomosing); type IV: combined forms of blood supply by caudal arteries and corpus arteries by way of anastomoses and non-anastomosing vessels are found; type V: the cauda is supplied exclusively be vessels stemming from the corpus. In each of these five types, individual vessels supplying the cauda can assume the function of a terminal vessel.

Aged↗
PubMed1985

[Lymphatic vessels of the upper extremity and their relation to nodes in the axillary area in healthy subjects and lymph flow blockade].

Large and small lymphatic vessels have been studied roentgenologically on the medial, lateral, posterior and anterior surfaces of the upper extremity in 113 patients at the age of 19-63 years at blockade of the lymphatic stream. On the medial and lateral surfaces the lymphatic vessels are filled with the contrast substance via anatomical approaches from the palmar and dorsal sides of the forearm. With isolated contrasting of various large lymphatic vessels, zones in the skin and in the subcutaneous fatty layers drained by them are revealed, as well as distribution of small vessels in the forearm and shoulder in each region. Variants of large lymphatic vessels and their tributaries are defined; an essential variability of their inflow into the axillary lymph nodes from various anatomical areas of the upper extremity is found. Into every 1-4 groups of the lymph nodes of the axillary area, 1-3 large vessels inflow, through them the contrast substance switches from the same anatomical zone repeatedly.

Adult↗
PubMed1979

[Morphology of coronary vessels in coronary heart disease. An analysis of 930 coronary angiograms].

Coronary anatomy was analyzed in 930 patients who underwent coronary arteriography because of coronary artery disease. There was a slight predominance of single vessel disease, whereas double and triple vessel disease were equally distributed. A left main (LM) lesion was found in 5.2%, with an additional right coronary artery lesion in 3.3%. The left anterior descending (LAD) artery was involved most frequently, followed by the right coronary artery (RCA) and left circumflex (Cx). The LAD demonstrated more often a proximal stenosis than the RCA and Cx. If the LM is associated with a RCA-stenosis then the LAD and Cx are involved more commonly, suggesting a more advanced disease in all major vessels. The analysis of ventricular function revealed a significant deterioration according to the number of diseased vessels. If the LM is associated with a RCA lesion, then the hemodynamics are similar to a 3-vessel disease, whereas isolated LM lesions are associated with good ventricular function according to the lesser degree of coronary sclerosis. The deterioration of the hemodynamics in correlation with coronary vessel involvement is significant, however due to the large standard deviations conclusions for the individual patient can not be drawn.

Coronary Angiography↗
PubMed1979

On the existence of stretchable pores in the exchange vessels of the isolated rabbit lung preparation.

In the present work our aim has been to seek evidence for or against the existence of stretchable pores in the exchange vessels of the lungs. In isolated rabbit lungs ventilated by positive pressure and perfused with homologous blood we performed repeated tests with fluid filtration from the exchange vessels. In these tests the outflow pressure was elevated to specific values for periods of 6 min. The rate of weight gain of the preparation during the last 2 min of each test period was taken as the rate of fluid filtration from the exchange vessels. We found a linear relationship between rate of filtration and outflow pressure in the range from 5 to 20 mm Hg. This indicates that the hydraulic conductivity of the exchange vessels did not change with outflow pressure and thus that no pore stretching occurred within this pressure range. An abrupt increase in filtration rate took place when the outflow pressure was set at 25 or 30 mm Hg. The hydraulic conductivity of the exchange vessels was therefore probably increased at these high pressures. Since in 3 lungs this increase in filtration rate was fully reversible we suggest that a stretching of pores in the exchange vessels of the lungs contributed to the increase in hydraulic conductivity. This stretching of pores occurred only when vascular pressures were at or above the upper level of the physiological pressure range for the lungs.

Animals↗
PubMed1979

The ratio of body haematocrit to venous haematocrit in open heart surgery and estimation of the blood volume in the large and small vessels.

Double tracer blood volume technique revealed in open heart surgery patients a wide variability of Fcells-value in about 11 per cent of cases investigated, from the "normal" 0.91 value. The possible calculational error of blood volume measurements by single-isotopic--haematocrit methods in the normal or subnormal LVH-ranges point to the superiority of plasma volume determinations in the calculation of the total blood volume. The calculation of the volume of the blood-component actually not-labelled during single-isotopic--haematocrit procedures can be so highly inaccurate because of the hidden deviation of Fcells-value, that such misleading arithmetics has no real value and therefore should be omitted. Estimation of the large vessel and small vessel volumes and haematocrits in patients showed a rough 70 per cent---30 per cent distribution of the circulating blood volume between large and small vessels and an LVH tosmall vessel haematocrit ratio of 2:1 to 2:1.5. This offers a possibility to divide the circulating blood volume into a haemodynamically active (large vessel area) and a metabolically active (small vessel area) part, which can have important diagnostic and prognostic implications.

Blood Volume↗