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PubMed1983

[Pathways of lymph movement in blockade of the medial superficial lymphatic vessels of the lower extremity].

A roentgen contrast investigation of the medial superficial lymph vessels has been undertaken in 69 patients (from 16 up to 67 years of age) suffering from various types of the posttraumatic edema when the lymph flow is blocked up. These vessels drain various anatomical areas, flow into certain segments of the lymphatic vessels, limited with definite segments from the beginning of their division up to the next branching of the major vessel. This causes a repeated redirection of the lymph flow along its way to various inguinal lymph nodes. In the lower third of the femur and on the crus from 1 to 6 lymph flows have been revealed at the expense of large lymph vessels of the lower extremities medial surface, which perform the redistribution of the lymph coming from the skin and the subcutaneous fat to various vessels and nodes of the inguinal area.

Adolescent↗
PubMed1983

Vessel wall and indium-111-labelled platelet response to carotid endarterectomy.

Postendarterectomy platelet deposition and thrombus formation may play an important role not only in vessel wall healing but also in the small incidence of postoperative cerebral ischemia and postoperative stenosis. A study has been performed using a canine model to investigate the healing response to carotid endarterectomy and the validity of an in vivo indium-111 (In-111) radiotracer technique in the assessment of postendarterectomy deposition of autologous labelled platelets. Sixteen endarterectomized carotid arteries showed uptake of autologous In-111 platelets immediately after infusion, reaching a maximum by 1 hour with little increase at 24 or 48 hours. No uptake was seen in ten control vessels following platelet infusion (P less than 0.05). At autopsy, seven vessels were demonstrated to have In-111 platelet deposition immediately prior to sacrifice of the animals. Postmortem scanning confirmed the localization to the vessel lumens, and microscopy revealed thrombus formation with or without partial endothelialization. Complete reendothelialization had occurred in the vessels that failed to show platelet deposition. Delayed healing was associated with continuing platelet deposition, excessive thrombus formation, and luminal stenosis. Arteriotomy closure with a vein patch altered the healing characteristics of the vessel with segmental thrombus formation over the vein patch. A preliminary study of the postendarterectomy in vivo In-111 platelet response in humans demonstrated platelet deposition that was not influenced by the administration of antiplatelet drugs at currently prescribed levels.

Animals↗
PubMed1983

Conjunctival and episcleral blood vessels are permeable to blood-borne horseradish peroxidase.

The vessels of the conjunctival and episcleral plexuses of Macaca mulatta eye are of the continuous type. Most of the vessels in the conjunctival plexus have the diameter of capillaries, while the vast majority of the vessels in the episcleral plexus are venules. Both types of vessels have a simple wall, which consists of an endothelium and a discontinuous layer of pericytes. The aim of this study was to establish their permeability properties to blood-borne horseradish peroxidase (HRP). After intravenous injection of HRP, in 200 microns chopper sections of the anterior segment of the eye examined with the light microscope, the subconjunctival and episcleral tissues appear intensely and diffusely stained by the reaction product. The electron microscope shows that HRP escapes from the vessels lumen by crossing the interendothelial clefts and, in addition, a great number of pinocytotic vesicles loaded with HRP are present on the luminal, tissue front and in the cytoplasm of the endothelial cells. HRP, which rapidly penetrates the loose connective tissue of the region, reaches the spaces between the cells of the conjunctival epithelium where it is finally blocked by the zonulae occludentes that connect the most superficial epithelial cells. A slow diffusion into the compact tissue of the cornea and of the sclera was also observed. Thus, under normal conditions, blood-borne macromolecules can freely diffuse into the subconjunctival and episcleral loose connective tissues. On the other hand, one can equally expect that the aqueous humor that reaches the episcleral and conjunctival blood plexuses through the canal of Schlemm and collector channels can freely diffuse into the subconjunctival spaces across the walls of these permeable vessels.

Animals↗
PubMed1982

Studies on the pathogenesis of avian rickets. I. Changes in epiphyseal and metaphyseal vessels in hypocalcemic and hypophosphatemic rickets.

Growth plate morphometry and measurements of serum chemistry were correlated to clarify the pathogenesis of hypocalcemic and hypophosphatemic avian rickets. Accumulation of proliferating and maturing cartilage in hypocalcemic chicks is accompanied by increased length and increased variation in length of perforating epiphyseal vessels, decreased number and abnormal arrangement of marrow spaces, an increased proportion of cells to blood vessels in marrow spaces, and a change in the distribution but not the total number of DNA-synthesizing chondrocytes per unit width of growth plate. Accumulation of hypertrophic cartilage in hypophosphatemic rickets is accompanied by no change in length, distribution, or number of perforating epiphyseal vessels, elongation but no change in number or arrangement of marrow spaces, an increase in the relative proportion of blood vessels to cells in the marrow spaces, and no change in distribution but a decrease in total number of DNA-synthesizing chondrocytes per unit width of growth plate. Both types of rickets have decreased amounts of calcified cartilage. These results provide further evidence that hypocalcemia and hypophosphatemia cause morphologically distinct types of rickets in birds. The data indicate that the thickness of the proliferating and maturing region and hence the distance of the hypertrophic zones from the epiphysis are anatomically and temporally related to length of perforating epiphyseal vessels and serum calcium levels. They indicate that in hypocalcemic rickets accumulation of proliferating and maturing cartilage is unlikely to be the result of increased chondrocyte replication and that the relative rates of chondrocyte hypertrophy and resorption of hypertrophic cartilage by marrow are equal. They support the concept that delayed chondrocyte hypertrophy is the major cause of growth plate thickening in hypocalcemic rickets. Data presented in this study, when considered together with data from the literature on hypophosphatemic rickets, support the long-held concept that growth plate thickening in this disease is caused primarily by a decreased rate of resorption of hypertrophic cartilage by marrow relative to the rates of chondrocyte proliferation, maturation, and hypertrophy. The data further support the concepts that growth of cartilage into marrow is a biphasic process including longitudinal growth effected mainly by blood vessels, and resorption of the lateral walls of marrow spaces effected mainly by marrow cells, and that it is the latter phase that is defective in hypophosphatemia.

Animals↗
PubMed1995

Changes in vessel wall plasminogen activator activity and smooth muscle cell proliferation and activation after arterial injury.

OBJECTIVES: The aim was to examine changes in vessel wall fibrinolytic activity following angioplasty and to assess any relationship to changes in smooth muscle cell proliferation and activation. METHODS: Balloon angioplasty was performed to the iliac arteries of New Zealand White rabbits and vessel wall changes assessed at 2 h, 1 d, 7 d, 14 d, and 1 month postprocedure. Tissue-type (tPA) and urokinase-type (uPA) plasminogen activator activity was assessed using chromogenic substrate assays, while smooth muscle cell proliferation and activation was monitored using expression of proliferating cell nuclear antigen (PCNA) and of basic fibroblast growth factor (bFGF) respectively. RESULTS: Intimal thickening progressively increased up to 1 month. uPA activity increased at 2 h [1.94(SEM 0.19) v 1.59(0.05) U.mg-1 tissue for control vessels, P = 0.03], remained increased at 24 h, but by 7 d had decreased to below control levels and remained low. In contrast, tPA activity fell significantly at 2 h [0.9(0.3) v 1.96(0.13) micrograms.mg-1 tissue for control vessels, P = 0.03], remained low at 24 h, but by 7 d had reverted back to control levels [2.19(0.39) micrograms.mg-1]. PCNA positivity of the media increased at day 1, reached maximum on day 7 [16.9(5.1)% positively staining cells] before returning to baseline by 1 month. PCNA positivity of the intima first evident at day 7 [0.7(0.3)%], reached a maximum at day 14 [4.1(0.4)%]. bFGF expression increased early at 2 h [mean(SE) positively staining cells: 15.7(5.3)% v 11.2(4.8)% for control vessels] and continued to increase, reaching a maximum in the media at day 7 [59(8.6)%] and in the intima at day 14 [57.5(5.7)%]. CONCLUSIONS: Balloon injury produced an initial fall in tPA and rise in uPA activity. tPA increased back to control levels by 7 d, while uPA fell to below control levels at 7 d and 1 month. This would be compatible with a mechanism whereby acute injury suppressed tPA and upregulated uPA activity, with increased tPA activity acting as a marker for vessel repair.

Angioplasty, Balloon↗
PubMed1994

[Detectability of cerebral aneurysms and surrounding vessels by three-dimensional evaluation using helical scanning CT (HES-CT)].

Helical scanning CT (HES-CT) is a new technique to enable high-speed volumetric data acquisition. We have applied HES-CT to the diagnosis of cerebral vascular diseases. In our experience, the relationship between the scanning parameters of HES-CT and image quality was complex and reciprocal, so that optimization of the parameters according to the clinical demands was essential. We compared HES-CT with conventional cerebral angiography to determine the detectability of the aneurysm and surrounding vessels, and sought the optimal parameters to delineate small vessels. All aneurysms were detected in multiplanar reconstruction (MPR) images. The smallest one was 3 x 4 mm. MPR images were found to have some advantages over conventional cerebral angiography in delineation of intracranial aneurysms: 1) scanning was over in a short time (30s), 2) the relationship between the aneurysm and surrounding vessels was easily recognized, 3) the diameter of the neck could be measured, because the neck of the aneurysm and parent artery could be imaged on the same plane without overlapping another vessel, 4) calcified lesions on the aneurysmal wall were detected, and 5) HES-CT was done safety without arterial puncture. However, the detectability of unknown aneurysm was less than the detectability of known aneurysm in MPR images. The 180 degrees interpolation algorithm and 1 mm slice were effective in detecting small vessels. However, vessels with a diameter less than 1 mm could not be detected by HES-CT. HES-CT was considered to be useful as a supplementary examination to conventional angiography for the diagnosis of intracranial aneurysms.

Adolescent↗
PubMedDate not supplied

Localization of atherosclerosis in arterial junctions. Modeling the release rate of low density lipoprotein and its breakdown products accumulated in blood vessel walls.

Arterial bifurcations and surgically created junctions at anastomoses are places where blood flow may be disturbed and slow recirculation may occur. To address the hypothesis that such disturbances in flow may result in atherogenesis, the transfer of atherogenic substances from vessel wall to flowing blood was studied theoretically using a two dimensional T-junction model. Calculations showed that the transfer of atherogenic substances from vessel wall into flowing blood was suppressed in the two regions of disturbed flow, one in the main vessel, the other in the subsidiary vessel. The lowest release rates were at the points of flow separation and were found to be much lower than those in the undisturbed flow regions. Therefore, our mathematical model predicts that locally disturbed blood flows at arterial bifurcations and surgically created junctions are responsible for two distinct phenomena. First, they provide favorable conditions for the accumulation of LDL at the luminal surface, thus increasing the potential for lipid infiltration into the vessel wall, and second, they impair the transfer into blood of atherogenic substances accumulated in the vessel wall. Such mass transfer abnormalities may account for atherogenesis and late failures of arterial grafts at these sites.

Anastomosis, Surgical↗
PubMed1993

[Distribution and three-dimensional reconstruction of lymphatic vessels of the elbow joint capsule of rabbits].

Lymphatic vessels are believed to be distributed in the the depth of synovial membrane, but the details of this distribution remain to be fully elucidated. The synovial membrane is classified in part on the basis of histological characteristics, even in the same joint capsule, into three fundamental types: adipose type, areolar type, and fibrous type. In addition, the adipose and areolar types are involved in the absorption of synovial fluid. In this study, the distribution of lymphatic vessels was investigated with special reference to histological structure of the synovial membrane. The materials were prepared from 11 elbow joint capsules of male 8 rabbits weighting 2-3 kg. Five specimens were stained with silver nitrate, and the remainder were stained with trichrome. All of the materials were serially sectioned and observed by light microscopy. Three-dimensional reconstructions of lymphatic vessels were performed using Cosmozone 2SA software (Nikon Co.) with a PC-9800 series microcomputer (NEC Co.) When the joint capsule is divided into synovial and fibrous layers in accordance with the Nomina Histologica Japonica, the fibrous layer is frequently connected with the epimysium of neighboring muscles. The synovial and fibrous layers are occasionally continuous with each other, without a distinct boundary. The number of lymphatic vessels in the synovial layer is small, and they originate in the vicinity of the border of the fibrous layer and pass over into the lymphatic vessels of the fibrous layer. Many lymphatic vessels were found in the fibrous layer, the majority of which come from the epimysium or perimysium close to the outer surface of the fibrous layer.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Succinylated wheat germ agglutinin lectin binding in intrahepatic vessels. A new histochemical tool.

Succinylated wheat germ agglutinin, specified by the amino sugar beta(4)-N-acetylglucosamine, bound frequently to the endothelial cells of the hepatic arterial branches and small vessels of the peribiliary capillary plexus, while it did not bind to the endothelial cells of venous vessels such as portal vein branches and hepatic venous radicles, nor to lymphatic vessels. Sinusoidal endothelial cells were also negative for succinylated wheat germ agglutinin. Proliferating small vessels in the enlarged portal tracts and fibrous septa in patients with extrahepatic biliary obstruction or chronic active hepatitis with or without cirrhosis tended to be positive for succinylated wheat germ agglutinin. Such findings have not been previously reported, to the best of our knowledge. Thus, succinylated wheat germ agglutinin may be a new and useful histochemical tool in routinely processed tissue sections to discriminate intrahepatic vessels into several categories, particularly into two categories (arterial and other vessels), in normal as well as diseased livers.

Bile Duct Neoplasms↗
PubMed1995

[Prognosis of patients with triple vessel disease and old myocardial infarction: relationship to the number of total coronary occlusions].

Patients with myocardial infarction (MI) and triple vessel coronary disease generally have poor prognoses. However, it is not known whether there are particular angiographic variables associated with the poor prognosis in MI patients with triple vessel disease. The angiographic variables for poor prognosis were investigated in 43 MI patients with triple vessel disease (32 men and 11 women, mean age 63 +/- 9 years) who were followed medically for a mean of 32 +/- 28 months. There were 13 cardiac deaths (30%) and 10 late-coronary artery bypass grafting (23%). Twenty patients were alive and well. The patients who died of cardiac causes had lower ejection fractions (42 +/- 18% vs 49 +/- 15%, p < 0.05), a higher prevalence of two vessel occlusion (77% vs 40%, p < 0.05), and a higher prevalence of coronary occlusion opposite the MI site (69% vs 25%, p < 0.01) when compared to survivors, although there were no significant differences in age, MI sites, or the prevalence of occlusion in the infarct-related artery. Multivariate analysis with the Cox proportional hazards model revealed that coronary occlusion opposite the MI site (hazards ratio 16.36) and an age of > or = 65 years (4.46) indicated a significantly high ratio. The hazard ratio of the ejection fraction and two vessel coronary occlusion were not significant. The poor prognosis of MI patients with triple vessel coronary disease may be related to impaired left ventricular function and to coronary occlusion opposite the MI site and greater age. This may have important clinical implications in the initial decision for interventional therapy.

Adult↗
PubMed1995

The relationship of granulomas to blood vessels in intestinal Crohn's disease.

It has been suggested that granulomatous vasculitis is a primary mechanism in the production of pathologic changes seen in Crohn's disease. We set out to investigate the relationship of granulomas to blood vessels and to confirm or refute previous reports of granulomatous vasculitis in Crohn's disease. Thirty paraffin embedded tissues from 11 patients with Crohn's disease were selected after examination of H&E stained sections for the presence of granulomas. Using an immunohistochemical method, various monoclonal antibodies were applied to sequential sections from each tissue to demonstrate vascular structures and granulomas. In three patients none of the granulomas occurred in association with blood vessels, in five a small proportion of the granulomas affected blood vessels, and in three granulomatous vasculitis appeared occlusive and significant. A total of 232 granulomas were identified, 22% of which were closely associated with blood vessels, which included both arteries and veins; 16% were perivascular, while 6% were intravascular. Perivascular granulomas did not surround blood vessels or invade the medial layers. They were asymmetric, suggesting that they originated by encroachment of nearby lymphatic or connective tissue granulomas. These results indicate that the granulomas of Crohn's disease are usually not associated with blood vessels; however, there is a minority of patients in whom vascular granulomatous inflammation may be important, although probably as a secondary phenomenon.

Adult↗
PubMed1995

Occurrence and coexistence of some neuropeptides in nerve fibers supplying the bovine ovary and its extrinsic blood vessels.

Single- and double-labelling immunofluorescence was applied to investigate the occurrence and coexistence of vasoactive intestinal polypeptide (VIP), calcitonin gene-related peptide (CGRP) and substance P (SP) in nerve fibers supplying the bovine ovary as well as its extrinsic blood vessels. We also studied the coexistence of these neuropeptides with tyrosine hydroxylase (TH) and neuropeptide Y (NPY) to determine features of "chemical coding" of nerve fibers innervating this organ. The bovine ovary was found to be supplied by VIP- and SP-immunoreactive (VIP- and SP-IR) nerve fibers. No intraovarian CGRP-IR nerve terminals were detected. Immunoreactivity to VIP was shown in a moderate number of nerve fibers occurring in all ovarian regions - ovarian hilus, cortex and medulla. VIP-IR nerves were found to innervate blood vessels and ovarian follicles, especially primordial and primary ones. Immunoreactivity to SP was detected only in solitary intraovarian nerve fibers which were also encountered in all ovarian regions, but with special preference to ovarian medulla, where they innervated blood vessels. SP-IR nerve fibres were sometimes observed in close vicinity to primordial and primary follicles. Double-labelling immunofluorescence revealed that some VIP-IR nerve fibres supplying intraovarian blood vessels were simultaneously TH- or NPY-IR. Small numbers of VIP-IR fibres contained immunoreactivity to SP. All SP-IR nerve terminals were TH-or NPY-negative. The ovarian artery as well as arteries of the paraovarian plexus were moderately supplied with VIP-, or by single CGRP- or SP-IR nerve fibres. Veins were innervated by only solitary nerve terminals containing these neuropeptides. The following patterns of coexistence were determined in nerve fibres supplying the investigated blood vessels: VIP, VIP/CGRP, VIP/SP, CGRP/SP, VIP/NPY. No distinct differences in the innervation of the ovary and its extrinsic blood vessels between juvenile and adult cows were found.

Age Factors↗
PubMed1977

Large vessel impedance in peripheral atherosclerosis.

Recent studies based on an animal model of arterial stenosis have shown that large vessel impedance (ZL), determined from the high-frequency vascular hydraulic impedance of a stenotic femoral arterial bed, is linearly related to the large vessel stenotic resistance, and somewhat independent of distal (small vessel) arteriolar resistance. To determine the applicability of these findings on human subjects with stenotic atherosclerotic lesions, ZL was determined in the femoral arteries of 17 patients (at the time of reconstructive operations) with no (N), mild (AS), and severe (occlusive) atherosclerotic (ASO) disease, and in a group of patients before and after femoral-to-popliteal bypass procedures (FEM-POP). Data were collected under steady-state conditions (SS) and during peak flow after a 30 mg bolus intra-arterial administration of papaverine hydrochloride (PAPAV). The ZL was found to be significantly greater (P less than 0.05) for the ASO group than for the N group at SS and after PAPAV administration. There was no significant difference in ZL between the SS and PAPAV conditions for all groups. The ZL decreased significantly (P less than 0.01) from the pre- to post-bypass conditions (with and without the stenosis), at steady-state and after papaverine hydrochloride administration. Large vessel impedance appears to provide a reliable index of the severity of a large vessel atherosclerotic stenosis, and is indpendent of small vessel resistance in humans. These findings are consistent with those of previous experimental animal studies.

Adult↗
PubMed1997

Disposition of vessel dilator and long-acting natriuretic peptide in healthy humans after a one-hour infusion.

The present investigation was designed to determine half-lives, distribution phases and metabolic clearance of two new cardiac peptide hormones in humans. Long-acting natriuretic peptide (LANP) and vessel dilator were infused at 100 ng/kg of b.wt./min concentrations for 60 min with their respective concentrations measured by specific radioimmunoassays in plasma during and for 3 hr after infusion. The half-life of vessel dilator was 107 min, whereas the half-life of LANP was 28 min. The average time that the respective peptides were retained in the body (mean residence time) was 214 +/- 34 min for vessel dilator and 178 +/- 12 min for LANP, which indicates that they are widely distributed outside the initial space (i.e., circulation). The metabolic clearance normalized to 1.73 m2 body surface area was 241 ml/min for vessel dilator and 249 ml/min for LANP. The total body clearance normalized to 1.73 m2 body surface area was 130 ml/min for vessel dilator and 293 ml/min for LANP. The significantly (P < .001) longer half-lives and slower metabolic clearance of LANP and vessel dilator compared with atrial natriuretic factor (half-life, 2.5 min, metabolic clearance, 582-2,581 ml/min/1.7 m2) explain why these peptides circulate at concentrations 15- to 24-fold higher than atrial natriuretic factor in healthy humans.

Adult↗
PubMed1998

Significant reduction of the large-vessel blood volume by food intake during hemodialysis.

Postprandial hypotension during hemodialysis is a serious problem. The reduction of the blood volume (BV) by ultrafiltration and the redistribution of the blood from the large vessels to the splanchnic organs are regarded to be the principle mechanisms of postprandial hypotension during hemodialysis. The hematocrit (Ht) of the large vessels is expected to increase by ultrafiltration and also by peripheral shift of the blood, because Ht of the peripheral vessels is much less than Ht of the large vessels. To analyze the effects of food intake during hemodialysis on BV of the large vessels quantitatively, we monitored Ht of the arteriovenous shunt blood continuously in the patients treated with hemodialysis regularly and estimated BV using the following equation, i.e., BV/initial BV = initial Ht/Ht. The rate of ultrafiltration was kept constant during the study. The reduction rate of BV was expressed as percentage of the initial BV per hour (delta BV). Ultrafiltration rate was expressed as percentage of the dry weight per hour (delta BV), delta BV was 3.24 +/- 0.57%/h (mean +/- SE) before the meal and increased to 13.99 +/- 0.91%/h almost instantaneously when the meal started in the supine position. The minimum value of BV was less than that estimated from the ultrafiltration rate by 2.65 +/- 0.26% of the initial BV. The effects of food intake disappeared in 43 +/- 3 minutes. When the meal was taken in the sitting position, delta BV was 28.21 +/- 2.14%/h, and the minimum value of BV was less than that estimated from the ultrafiltration rate by 4.69 +/- 0.70% of the initial BV. We conclude that food intake during hemodialysis decreases BV of the large vessels transiently but significantly. The effects of food intake on BV were more severe when the meal was taken in sitting position than those when the meal was taken in supine position.

Adult↗
PubMed1996

[The mechanism of vasculogenesis: the critical role of transforming growth factor-beta 1 in the formation of vessel-like structures during the differentiation in vitro of murine embryonic stem cells].

When ES-5 cells were transfected with an exogenous porcine TGF-beta 1 gene, one can obtain clones of genetically modified ES cells with over-expression of the transfected gene. We called the genetically modified ES-5 cells as ES-T cells. When ES-T cells were used to study their differentiation in vitro by all trans-retinoic acid (RA), it was soon noticed that embryoid bodies of ES-T cells can exclusively differentiate into endothelial cells and vessel-like structures, but not in their parent ES-5 cells. The above result is the first indication that the differentiation of tubular structures in embryoid bodies of ES-T cells may somehow be related to TGF-beta 1. To demonstrate further the role of TGF-beta 1 in the formation of vessel-like structures, the cultured ES-5 cells in the presence of added rhTGF-beta 1 were closely followed in the course of their differentiation. We have, thus, demonstrated the promoting effects of exogenous rhTGF-beta 1 in the formation of vessel-like structures, morphologically similar to those structures derived from ES-T6 cells, during the differentiation of ES-5 cells, both in monolayer culture, in three dimensional collagen gel and in embryoid bodies cultured on gelatin-coated tissue culture wells. Addition of suitable amount of anti-TGF-beta 1 monoclonal antibody IgG (TB21) to the culture medium of embryoid bodies of ES-T6 cells could effectively abolish the formation of vessel-like structures induced by retinoic acid. The percentage of the inhibition was very high, giving a figure comparable to that of atypical vessel-like structures formed in the control embryoid bodies from their parent ES-5 cells. The flat epithelial-like cells and round cells differentiated from embryoid bodies of ES-T6 cells were stained rather strongly for laminin and type IV collagen by immunofluorescent procedure. The above results indicate clearly that TGF-beta 1 is a crucial factor in organizing the differentiated derivatives (endothelial-like cells and their immediate progenitor cells) from ES-T6 cells to form vessel-like structures, and that the role of TGF-beta 1 in vasculogenesis might be performed, in part, through the modulation of the composition and organization of the extracellular matrix. In addition, the enhanced expression of bFGF mRNA in derivatives differentiated from both ES-5 cells treated with rhTGF-beta 1 and ES-T6 cells were detected by Northern blot analysis. Thus, aside from its effects on extracellular matrix, TGF-beta 1 might also modulate the bioactivity of bFGF in relation to the growth of vascular endothelial cells in the present system.

Animals↗
PubMed2006

Comparison between stenting and balloon angioplasty in patients undergoing primary angioplasty of small coronary vessels.

BACKGROUND: Primary angioplasty has been shown to improve outcomes in selected patients with ST-segment elevation myocardial infarction. However, no information has been reported so far in small vessels. In the Zwolle-6 randomized trial, consecutive patients with ST-segment elevation myocardial infarction were randomized to stenting or to balloon angioplasty without any exclusion criterion. In this study, we present data on patients with small vessels (< 3.0 mm). METHODS: From April 1997 to October 2001, 798 patients randomized to balloon angioplasty or to stenting before their initial angiogram underwent primary angioplasty of small vessels, defined according to a postprocedural reference diameter < or = 3 mm. One-year follow-up data were available from all patients. RESULTS: Three hundred eighty-seven patients were randomized to stent, whereas 411 were to balloon. The crossover rates from balloon to stent and from stent to balloon were 28% and 13.9%, respectively (P < .001). The groups were comparable in terms of postprocedural TIMI flow, myocardial blush grade, distal embolization, and ST-segment resolution. No difference was observed in 1-year mortality (7.2% vs 5.8%, P = not significant [NS]), target vessel revascularization (17.8% vs 22.1%, P = NS), and major adverse cardiac events (24.8% vs 29.0%, P = NS) between the groups. CONCLUSIONS: As compared with balloon angioplasty, routine stenting does not seem to improve clinical outcomes in patients undergoing primary angioplasty of small vessels. Future trials are certainly needed to evaluate the safety and benefits of drug-eluting stents in this high-risk subset of patients.

Aged↗
PubMed2006

Increased angiogenesis and blood vessel maturation in acellular collagen-heparin scaffolds containing both FGF2 and VEGF.

An important issue in tissue engineering is the vascularisation of the implanted construct, which often takes several weeks. In vivo, the growth factors VEGF and FGF2 show a combined effect on both angiogenesis and maturation of blood vessels. Therefore, we hypothesise that the addition of these growth factors to an acellular construct increases blood vessel formation and maturation. To systematically evaluate the contribution of each scaffold component with respect to tissue response and in particular to blood vessel formation, five porous scaffolds were prepared and characterised, viz.: collagen, collagen with heparin, and collagen with heparin plus one or two growth factors (rrFGF2 and rrVEGF). Scaffolds were subcutaneously implanted in 3 months old Wistar rats. Of all scaffolds tested, the one with a combination of growth factors displayed the highest density of blood vessels (type IV collagen) and most mature blood vessels (smooth muscle actin). In addition, no hypoxic cells were found in this scaffold at day 7 and 21 (hypoxia inducible factor 1-alpha). These results indicate that the addition of both FGF2 and VEGF to an acellular construct enhances an early mature vasculature. This opens prospects for (acellular) tissue-engineered constructs in conditions as ischaemic heart disease or diabetic ulcers.

Animals↗