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PubMedDate not supplied

Threshold and retreatment parameters of NPe6 photodynamic therapy in retinal and choroidal vessels.

BACKGROUND AND OBJECTIVE: To determine the threshold fluence for producing choroidal and retinal vascular occlusion with mono-L-aspartyl chlorin e6 (NPe6) photodynamic therapy (PDT) during primary treatment and the effect of retreatment. METHODS: Primary treatment: Rats, rabbits, and monkeys underwent NPe6 PDT to determine the threshold fluences for choroidal and retinal vessel occlusion. The threshold was determined by analyzing fluorescein angiograms for areas of nonperfusion. Retreatment: Dutch-belted rabbits underwent NPe6 PDT followed by fluorescein angiography. Rabbits were retreated one week later at the same parameters. RESULTS: Fluence levels and vascular damage thresholds were always higher for retinal than for choroidal vascular occlusion. Retreatment caused choroidal vessel closure at all tested fluences but retinal capillaries closed only at a fluence > 17.7 J/cm2. CONCLUSION: NPe6 PDT has a lower threshold to occlude choroidal vessels than retinal vessels. The cumulative effect of retreatment does not damage retinal vessels unless the threshold is exceeded during a single retreatment session.

Animals↗

PubMed1995

Enzyme histochemical studies on tumor blood vessels.

The oxygenation, the growth rate and the metastatic potential of a solid tumor depend on its vascularization and, in particular, on angiogenesis; a therapeutic approach affecting angiogenesis has been suggested as an alternative to conventional ones. Especially the study of the metabolism in the cells of the vessel wall should be a useful prerequisite for this approach. In this connection, an enzyme histochemical study was performed to characterize the blood vessels in a solid tumor (Ehrlich carcinoma). The following enzymes were considered: (a) alkaline phosphatase, involved in the transcellular phosphate transport and in the response to inflammatory and growth promoting factors; (b) dihydrofolate reductase, involved in the metabolism of tetrahydrofolate (for the synthesis of nucleic acids and the metabolism of serine and glycine); (c) purine nucleoside phosphorylase, involved in the degradation of purines and, in particular, of extracellular ATP and ADP; (d) xanthine oxidoreductase, engaged in the same degradation path and leading to the formation of urate, a strong antioxidant. Various patterns of enzyme activities were observed in the vessel wall. In particular, thin linear capillaries (presumed to be host capillaries penetrating the tumor) were identified for the intense positivity of alkaline phosphatase, dihydrofolate reductase and purine nucleoside phosphorilase; tortuous capillaries with variable diameters (presumed to be induced by angiogenesis from the host vessels) were negative for the alkaline phosphatase and expressed an heterogeneous pattern for the dihydrofolate reductase. All the data suggest a different vessel behaviour concerning the response to cytokines and to inflammatory stimuli.

Alkaline Phosphatase↗

PubMed1975

Mechanical Excision and removal of intravitreal vessels. I. In animals.

We wished to know if excision of artificially produced intravitreal vessels would cause bleeding and if the hemorrhage could be controlled by increasing the intraocular pressure. In 17 rabbit eyes, the distal end of several intravitreal blood vessels was excised and removed by the Peyman vitrophage. No significant bleeding occurred from the vessels in 13 eyes, and in the remaining four bleeding stopped after 30 seconds or less of increased intraocular pressure. In one month of observation after surgery, there was no evidence of delayed hemorrhage. Electron microscopy of several transected intravitreal vessels revealed that vessel constriction, platelets and fibrin strands contributed to the prevention of immediate and delayed hemorrhage.

Ammonium Chloride↗

PubMed1975

[Method for the functional evaluation of contrasted vessels of the lungs with the aid of stereoroentgenogrammetry and morphometry].

A complex method for measuring vessels of the lungs is suggested; the method includes a number of successive procedures: contrasting of vessels under physiological pressure, stereoscopy of the preparation of the lung in a non-atelectatic and non-fixed state and obtaining of stereopaired angiograms, marking the levels of branching of vessels and determination of their lumen by means of stereocomparator, fixation of the lung, spot cutting and morphometry of the wall of the same segments of the lung vessels. The size of the lumen of the vessel approximating the intravital one, was combined with morphometric parametres of its wall and indices were calculated characterizing a morpho-functional state of the blood flow bed of the lungs.

Angiography↗

PubMed1975

[Effect of transverse gravitational loads on the vessels of the retinal membrane of the rabbit eyeball].

Changes in the eye ball retina were studied in 3 series of experiments in cleared preparations after exposure of the animal to gravitation stress of transversal direction. Prolonged single functionally endurable stress of ventro-dorsal direction (10 units/3 min) caused dilatation of the retina vessels, worse filling of peripheral parts of the circulatory bed, uneven staining of the vascular wall, constriction and dilatation along the course of the vessel. More continuous exposure to the same value of stresses (10 units up to the animal's death) resulted in a pressor effect; qualitative changes in the vessels increased. Within 1,5 hour after a 3-minute-long exposure to stress the vascular bed still remained unchanged. The diameter of vessels approached normal while the general quantity of vessels was decreased and qualitative changes were well pronounced.

Animals↗

PubMed2001

Characterization of first trimester human fetal placental vessels using immunocytochemical markers.

Cell differentiation markers on placental villi from the first trimester of human pregnancy have been studied by indirect immunofluorescence. Fluorescence labelling with antibodies against CD34 and CD31 was conspicuous in the vascular cells. The vascular paracellular clefts were labelled by anti-cadherin-5. A few vascular cells exhibited a positive reaction for von Willebrand factor, high-molecular-weight melanoma-associated-antibody and alpha-sm-actin compared to term pregnancy, indicating changes in protein expression during vascular differentiation. The poor anti-collagen IV reaction and the absence of a sm-myosin fluorescent signal observed around the vessels confirned the immaturity of the vessels. In contrast, strong reactions have previously been obtained with the latter antibodies in similar locations using term placental villi. A labelling was observed for antibodies against alpha3 and alpha5 integrins in these immature placental vessels suggesting cell-matrix interactions with specific domains of laminin or fibronectin. The vascular cells were also stained by anti-CD26. Surprisingly, the fetal vascular cells exhibited immunostainings in common with the villous cytotrophoblast (CD26) or the syncytiotrophoblast (cadherin-5) and cell islands cytotrophoblast (CD31, cadherin-5, alpha3 and alpha5 integrin subunits). These observations suggested a two step process for fetal vasculogenesis in the villi: i/ the formation of peripheral vessels induced by growth factors or cytokines derived from the nearby trophoblast, ii/ the development of muscular vessels due to growth factors or cytokines production induced by circulatory changes.

Actins↗

PubMed2002

Immunoreactivities of eNOS, ET-1 and ETB-R in blood vessels of the uterine mesometrium during the estrous cycle in the pig.

Cryostat sections of arterial and venous vessels from various size branches of the uterine artery and utero-ovarian vein of the pig mesometrium in different phases of the estrous cycle were stained immunohistochemically for endothelial nitric oxide synthase (eNOS), endothelin-1 (ET-1) and endothelin B receptor (ETB-R) using ABC method. Immunoreactivity was evaluated according to 6-point scale under light microscope. The differences in immunostaining intensity in the endothelium of the vessels studied at various levels of mesometrium suggest a correlation of eNOS, ET-1 and ETB-R expression with the estrous cycle. In the follicular phase, the highest eNOS immunoreactivity was noticed in arcuate arteries and veins, while immunoreaction of ET-1 was much lower, just as ETB-R. On the other hand, the highest ET-1 immunoreactivity was observed during first 2 days afterovulation, while ETB-R showed low immunoreactivity level during the whole luteal phase. Vessels from the middle part of mesometrium (I degrees and II degrees branches) and large vascular trunks revealed similar staining for eNOS during the cycle as compared to arcuate arteries. Those vessels showed very high immunoreactivity levels for ET-I and ETB-R during first 2 days after ovulation. Our results suggest that during the estrus eNOS, ET-I and ETB-R play a significant role in the regulatory process of blood flow through the mesometrial vessels, that are connected to the uterine horn.

Animals↗

PubMed2002

Fractal characteristics of brain vessel microangioarchitecture during the fetal period.

BACKGROUND: Studies of human telencephalon during the fetal period are rare. Recent technologies, such as the Pickworth method, ultraviolet, infrared, and computer image systems, now enable the observation of such barely accessible structures. The present study constitutes an evaluation of the microangioarchitecture of brain vessels during the fetal period and the creation of a fractal model to describe it. Studies formulated in the language of fractals have never previously been applied in modeling brain vessels. MATERIAL/METHODS: We studied 100 brains in the 4th to 8th month of fetal life, using the Pickworth method, computer image analysis under three different systems, the POV-RAY program, and fractal analysis. RESULTS: The POV-RAY program was used to generate 3-dimensional, tree-like structures. This requires three scaling parameters: length, vessel diameter, and the angle between the branches and the central axis. The vessel structure was modeled by fractals with condensation point. Moreover, these tree-like fractals have different one-sided dimensions. In making fractal models we treated these one-sided dimensions as numerically evaluated parameters of the theory. Of course, the accuracy of the proposed models depends upon the accurate prediction by a fractal of the examined structure. CONCLUSIONS: Brain vessels can be modeled with the help of fractals with condensation points, which have differentiated one-sided dimensions.

Blood Vessels↗

PubMed2000

[Filling blood vessels with latex and its application].

The purpose of this study is to find out the better conditions for filling blood vessels of the body with latex. We test it on 500 bodies. Our data show that the temperature for storing the latex, filling positions, the wash of blood vessels prior to filling and filling pressure are all important in this process. A good filling increases elasticity of vessels, makes vessels stronger and facilitates dissection of vessel. It is of importance in the study of cardiovascular system.

Blood Vessels↗

PubMed2002

Histological study on the influences of an ultrasonic scalpel on skeletonized vessel wall.

OBJECTIVE: The objective of this study was to histologically clarify the difference of vascular wall damage when an ultrasonic scalpel is used in varied ways in the vicinity of a vessel. SUBJECTS AND METHODS: 1) The surface of sodium carbonate-containing jelly was manually brushed with the edge of a dissecting hook type Harmonic Scalpel (HS), and the thickness of the air bubble layer was measured to investigate the range to which the vibrations of the instrument reached. 2) The internal thoracic artery (ITA), radial artery (RA) and vein skeletonized were cut bluntly or brushed using HS ex vivo, and tissue damages were observed histologically. 3) The depth of thermal degeneration (TD) of residual stumps of ITAs skeletonized by HS using an output power level (level) of 2 and the quick touch method at the time of coronary arterial bypass grafting (CABG) were investigated histologically. RESULTS: 1) The mean thickness of the air bubble layers by single brushing was 3.7, 3.7 and 3.1 mm at level 4, 3 and 2, and no significant difference. When brushed 5 times, it was 6.9, 5.5 and 6.7 mm, respectively, showing marked increases compared with single brushing. 2) A: One side of the RA stump cut with a dissecting hook at level 2 was nicely occluded by a degenerated protein coagulum, but the contralateral had no coagulum. An ITA cut by a shear type blade at level 3 showed that both stumps were nicely occluded, but the vessel wall was introverted and fragmented. B: ITAs brushed 5 or 10 times at level 2 showed that TD occurred in tunica externa, the mean depth of 100 or 203 microm, and never exceeded the external elastic lamella. RAs brushed 10 times at level 2 and 3 showed that TD and air bubble generation occurred in the tunica externa, and the mean depth was 203 and 203 microm. However, TD exceeded the external lamella in some cases at level 3. Veins brushed 10 times at level 3 showed that TD spread to all layers. 3) The depth of TD in ITAs skeletonized clinically by HS was 400 to 530 microm, and apart from the external elastic lamella. CONCLUSIONS: 1) Though the air bubble layer was very thick in jelly, it was observed only in tunica externa ex vivo. 2) For coagulation and cut of small blood vessels, it is vital to press an HS blade edge onto the vessel so as to press equally both portions to be cut. There is a possibility of a fragmented and introverted vessel wall into the lumen. 3) By dissecting ITA and RA using HS at level 2 and the quick touch method, TD can be limited to the depth of the connective tissue of tunica externa.

Blood Vessels↗

PubMed1992

Presence of angiotensin converting enzyme in the adventitia of large blood vessels.

BACKGROUND: Angiotensin converting enzyme (ACE) is present in the endothelial cells of all vascular beds. There are, however, many reports of converting enzyme activity in blood vessels not associated with the endothelium. METHODS: ACE was localized in large blood vessels of a number of mammals by in vitro autoradiography using the radioligand 125I-351A. To characterize this binding further, immunohistochemistry was performed on rabbit aorta using polyclonal antisera raised to two different preparations of rabbit lung ACE. RESULTS: In all of the blood vessels studied, which included the rabbit pulmonary artery, rabbit, dog and sheep aorta, human internal mammary artery and human saphenous vein, high levels of radioligand binding were found in endothelial cells, as expected. In addition, a very high density of punctate binding was observed interspersed between diffuse moderate labelling in the adventitia. Immunoreactivity was confined to the endothelium of both the intima and the vasa vasorum of the adventitia. The immunostaining correlated well with the autoradiography. The ACE inhibitors lisinopril and perindoprilat displayed similar high affinities in competing for the binding of 125I-351A to the endothelium and adventitia of the sheep aorta, suggesting that at these two sites the radioligand was binding to ACE. CONCLUSIONS: We find that ACE in the adventitia of large blood vessels is confined to the vaso vasorum. The results of this study help to explain the findings of many studies that ACE activity persists in endothelium-denuded blood vessels and also reveals a source of ACE distant from the luminal endothelial surface.

Angiotensin-Converting Enzyme Inhibitors↗

PubMedDate not supplied

[The specificity of the ultrastructural pattern of neoplastic vessels of the retina in diabetic retinopathy].

The electron microscopy of 14 samples of epiretinal membranes obtained in the course of transciliary vitrectomy performed in proliferative diabetic retinopathy (PDR) showed a majority of neovascularized vessels to be represented by those of the venular type or capillaries. It can be concluded on the basis of examination results that the structures of neovascularized vessels can be highly diverse in diabetic retinopathy, which depends on a variety of factors: 1) proliferation stage; 2) division of the microcirculation bed; and 3) end of the epiretinal membrane where a given vessel is located as to the growth epicenter. Finally, described are both neo-vessels with a virtually normal structure of the vascular wall and atrophying vessels. The signs of vascular reduction grow to be more pronounced at later stages.

Diabetic Retinopathy↗

PubMed2005

[Repair of defects at both ends of blood vessels in extremities with a great disparity in diameter by vein transplantation].

OBJECTIVE: To repair defects at both ends of the blood vessels with a considerable disparity in the diameter of the both sides or with a large diameter in extremities by phleboplasty of branched and double autogenous veins. METHODS: Three kinds of phleboplasty: funnel-shaped, raincape-shaped and transposed Y-shaped were designed. Experiments in fresh blood vessels in vitro were completed successfully. These methods were used clinically to repair injured external iliac veins, femoral arteries and veins, and popliteal arteries and veins, to replant severed fingers and to transplant toenail flaps on thumbs by harvesting autogenous great saphenous veins, small saphenous veins and forearm veins in 36 cases, including 35 cases in emergency operation and 1 case in selective operation. The length of The phleboplasty of funnel-shaped could enlarge the grafted blood vessels ranged from 1.0 cm to 15.0 cm. RESULTS: The phleboplasty of funnel-shaped could enlarge the diameter by 1.0-1.25 times in anastomotic stomas. The phleboplasty of raincape-shaped could enlarge the diameter large enough to meet the demands for various blood vessels in extremities. The phleboplasty of transposed Y-shaped could provide large vein transplants. In 36 grafted veins, 35 were in patency. The blood supply in extremities was normal. CONCLUSION: The funnel-shaped and raincape-shaped phleboplasty of branched veins can enlarge the anastomotic stomas of grafted veins. The transposed Y-shaped phleboplasty of double femoral veins is an ideal way to repair injured primary blood vessels with a considerable disparity in the diameter of the both sides or with a large diameter in extremities.

Adolescent↗

PubMed2005

[Morphology of lymph vessels in human gastric carcinoma tissues and its association with cancer metastasis].

OBJECTIVE: To investigate the morphology of the lymph vessels in human gastric carcinoma tissues and the relationship to cancer metastasis. METHODS: Morphological changes of the lymph vessels and capillaries in 32 cases of gastric carcinoma tissues and adjacent tissue of the tumor. RESULTS: Numerous lymph vessels and capillaries were seen with opened lumen in the adjacent tissues of the tumor, and fasciculated lymph capillaries were most frequent in gastric carcinoma. The maximal lumen area, perimeter and diameter of lymph vessels and capillaries in gastric carcinoma and the adjacent tissues were significantly different between metastatic group and non-metastatic group (P<0.05). CONCLUSIONS: Dilation of lymph vessels and capillaries due to interstitial edema of the adjacent tissues of gastric carcinoma facilitates tumor metastasis, and lymph metastasis of carcinoma cells occurs through mature lymph capillaries in the adjacent tissues.

Humans↗

PubMed2005

[Study of the method to measure the diameter of retinal vessels].

PURPOSE: To estimate the objective and repeatable method for measurements of the retinal vessels' diameter. The direct reason for creating this method was to use it to evaluate the influence of exogenous estrogens on the retinal blood vessels. MATERIAL AND METHODS: Based on modern computer systems, using funduscamera Canon NF 505, the model of active matrix for repeatable method for estimating the changes in vessels' diameter, was elaborated. RESULTS: After statistical analysis of a material of 3000 measurements, the degree of objectiveness and recurrence and the potential scale for errors was acknowledged. This method enables the estimation of the changes in retinal vessels diameter caused by many different factors in comparison to initial observations (set as 100%) in every analysed case. CONCLUSIONS: Presented method can be successfully used for objective, reliable evaluation of changes in the blood vessels diameter caused by many different factors.

Estrogens↗

PubMed1992

Blood vessel architecture in lymph nodes of the dog viewed by scanning electron microscopy.

Scanning electron microscopy was used to investigate the submicroscopic organization of the blood vessels of dog lymph nodes (LN). The LN vessels were casted by systemic perfusion of the animals vasculature with two resins of distinct viscosity. This resulted in the retrieval of two types of LN vascular replicas that depicted either the arterial blood system alone (methacrylate casting) or both the arterial and venous blood systems (Mercox casting). We found that the dog LN showed a significantly higher density of arterial vessels in the cortex than in the medulla. In the cortical domain, a subcapsular layer stood out because of its rich content in arterial capillaries. The use of the high-resolution resin (mercox) resulted in excellent structural detail of the luminal surface of the LN vessels that allowed a clear distinction between arterioles and venules based on the geometrical pattern of the imprints left in the replicas by the nuclei of endothelial cells. At the cortex-medulla frontier, most arterioles showed narrowings of their lumen that suggested the existence of sphincters at this level. Our findings document that the microanatomical arrangement of blood vessels in the LN of the dog is different from that of LN from other mammals studied so far, in particular from rodents where vascular-poor microdomains have been reported in the LN cortex. The arteriolar sphincters that we detected at the innermost zone of the cortex may represent the structural counterpart of the physiological modulation of the blood supply of the cortex exerted by arterial branches coming from the hilus.

Animals↗

PubMed2005

[The role of superoxide anions in regulation of coronary vessel tone and myocardial contractile function in changed redox-state of the myocardium].

The study relates to the character of tirone effect (chemical trap of superoxide--anions) on regulation of coronary vessel tone and myocardial contractile function in normal and changed cell redox-state of coronary and cardiac vessels. The experiments were performed in 64 female Wistar rats (180-320 g). The coronary blood flow and myocardial contractile junction were studied in isolated heart preparations. To determine the role of superoxide-anions in regulation of coronary vessel tone, tirone was added to the perfusion solution (4,5-dihydroxy-1,3-benzene disulfonic acid, 10 mm, Sigma USA). Preliminary injection of N-acetyl-L-cysteine evoked a 16 % increase, whereas injection of L-buthionine-(S,R)-sulfoximine reduced concentration of nonprotein thiol group in the myocardium and erythrocytes of experimental animals by 37%. The influence of superoxide anions on the cardiac vessel tone and myocardial contractile function was due to nitric monoxide participation the concentration of which increased in binding of superoxide anions and was directly dependent on concentration of sulfhydrilis groups in the cardiac cells. The oxygen active forms and cellular redox-state seem to play an important role in the regulation mechanisms of the coronary vessel tone and myocardial contractile function.

1,2-Dihydroxybenzene-3,5-Disulfonic Acid Disodium ↗

PubMed2006

Blood vessels recovered with organs and intended for use in organ transplantation. Direct final rule.

The Health Resources and Services Administration (HRSA) and the Food and Drug Administration (FDA) are amending their regulations to consider as part of an organ those blood vessels recovered with the organ that are intended for use in organ transplantation (HRSA regulation); and to exclude such blood vessels from the definition of human cells, tissues, and cellular and tissue-based products (HCT/Ps) (FDA regulation). We (HRSA and FDA) are taking this action to provide that blood vessels recovered with organs and intended for use in organ transplantation are governed by the regulations pertaining to organs. The regulation of other recovered blood vessels remains unchanged. We believe that this change will eliminate the unnecessary burden resulting from an organ procurement organization's efforts to comply with both FDA and HRSA rules with respect to blood vessels (FDA jurisdiction) and organs (HRSA jurisdiction). We are issuing these amendments directly as a final rule because they are noncontroversial, and there is little likelihood that we will receive any significant adverse comments. Elsewhere in this issue of the Federal Register, we are publishing a companion proposed rule under our usual procedures for notice and comment in the event that we receive any significant adverse comments on the direct final rule. If we receive any significant adverse comments that warrant terminating the direct final rule, we will consider such comments on the proposed rule in developing the final rule.

Blood Vessels↗