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Blood Vessels (blood + vessel)
Kinds of Blood Vessels Terms modified by Blood Vessels Selected AbstractsPROTECTIVE ROLE OF A NOVEL ERYTHROCYTE-DERIVED DEPRESSING FACTOR ON BLOOD VESSELS OF RENOVASCULAR HYPERTENSIVE RATSCLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2007Huan Pang SUMMARY 1We have isolated a novel human erythrocyte-derived depressing factor (EDDF) that has a significant antihypertensive effect in various rat models of hypertension. The aim of the present study was to examine the mechanisms of action of EDDF on vascular function in two-kidney, one-clip (2K1C) renovascular hypertensive rats. 2The EDDF was prepared from human erythrocytes. Experiments were performed in 18 male Wistar rats. The vascular ring perfusion assay and a two-photon laser scanning fluorescence microscope (TMP) were used to evaluate the vascular contractile response. The effects of EDDF on phenylephrine (PE)- and noradrenaline (NA)-induced vascular contraction were evaluated in 2K1C hypertensive rats. The proliferation and DNA synthesis in vascular smooth muscle cells (VSMC) were determined using the [3H]-TdR (thymidine) incorporation and 3-(4,5-dimethyl-2 thiazoyl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assays. Flow cytometry, reverse transcription,polymerase chain reaction and western blots were used to measure cell cycle and apoptotic profiles, platelet-derived growth factor (PDGF)-A expression and the activity of extracelluar signal-regulated kinase (ERK)-1/2, as well as the expression of cyclin D1 and cyclin-dependent kinase (CDK) 4. 3At 10,5 g/mL, EDDF significantly decreased the PE- and NA-induced hypertensive vascular contraction. In addition, EDDF inhibited DNA synthesis in primary VSMC from 2K1C rats. The mRNA expression of PDGF-A in VSMC was twofold higher in 2K1C rats compared with control rats, whereas EDDF significantly inhibited the increment in PDGF-A mRNA expression. In addition, EDDF inhibited the phosphorylation of ERK1/2 and decreased the expression of cyclin D1 and CDK4; p21 (Cip1) levels were increased after treatment with EDDF. 4In conclusion, EDDF inhibits VSMC proliferation in 2K1C rats through G0/G1 cell cycle arrest. The effects may be mediated, in part, by enhanced expression of p21 (Cip1) and the inhibition of ERK1/2 phosphorylation and the expression of cyclin D1/CDK4 and PDGF-A. [source] Histological Assessment of Selected Blood Vessels of the Phocid Seals (Northern Elephant and Harbour Seals)ANATOMIA, HISTOLOGIA, EMBRYOLOGIA, Issue 3 2010H. Smodlaka Summary Phocid seals exhibit vascular adaptations that allow them to undertake prolonged deep dives. These vascular adaptations are either unique to phocids, or are modified vascular equivalents to those present in terrestrial mammals. One such adaptation, the aortic bulb, is a spherical enlargement of the ascending aorta specific to phocid seals. Its histological make-up consists of a reinforced tunica media with circular and longitudinal layers of elastic fibres. This reinforcement enables multi-axial deformation of the aortic bulb, thus complementing its function as a prominent elastic reservoir or ,windkessel'. A second adaptation, the hepatic sinus, is an asymmetrical dilation of the abdominal portion of the caudal vena cava and accompanying hepatic veins. The hepatic sinus is comprised of a relatively thin tunica media, with a scant smooth muscle component. The bulk of the sinus wall is comprised of tunica adventitia. A third vascular adaptation distinctive to the phocids is the pericardial venous plexus, composed of convoluted veins circumnavigating the perimeter of the heart. Microscopically, these veins have a thick tunica media and also contain valves. Smaller arteries, venules and distinct capillary beds are observed interspersed in-between these veins. It can be hypothesized, that in seals, certain vascular embryonic development may be arrested at an earlier embryonic stage, resulting in these unusual vascular formations. These modifications play a vital role in blood pressure regulation and distribution of oxygenated blood during prolonged deep diving. The purpose of this work was to elucidate the histological aspects of these unique vascular modifications and relate them to specific function. [source] Vascular response to laser photothermolysis as a function of pulse duration, vessel type, and diameter: Implications for port wine stain laser therapyLASERS IN SURGERY AND MEDICINE, Issue 2 2002Sol Kimel PhD Abstract Background and Objective Treatment of port wine stains (PWS) by photothermolysis can be improved by optimizing laser parameters on an individual patient basis. We have studied the critical role of pulse duration (tp) on the treatment efficacy. Study Design/Materials and Methods The V-beam laser (Candela) allowed changing tp over user-specified discrete values between 1.5 and 40 milliseconds by delivering a series of 100 microsecond spikes. For the 1.5 and 3 millisecond pulses, three spikes were observed at intervals tp/2 and for tp,,,6 milliseconds, four spikes separated by tp/3. The ScleroPlus laser (Candela) has a smooth output over its fixed 1.5 milliseconds duration. Blood vessels in the chick chorioallantoic membrane (CAM) were irradiated at fixed wavelength (595 nm), spot size (7 mm), radiant exposure (15 Jcm,2), and at variable tp. The CAM contains an extensive microvascular network ranging from capillaries with diameter D,<,30 ,m to blood vessels of D,,,120 ,m. The CAM assay allows real-time video documentation, and observation of blood flow in pre-capillary arterioles (A) and post-capillary venules (V). Vessel injury was graded from recorded videotapes. Mathematical modeling was developed to interpret results of vessel injury when varying tp and D. A modified thermal relaxation time was introduced to calculate vessel wall temperature following laser exposure. Results Arterioles. For increasing tp, overall damage was found to decrease. For fixed tp, damage decreased with vessel size. Venules. For all D, damage was smaller than for corresponding arterioles. There was no dependence of damage on tp. For given tp, no variation of damage with D was observed. Photothermolysis due to spiked (V-beam) vs. smooth (Scleroplus) delivery of laser energy at fixed tp (1.5 milliseconds), showed similar vessel injuries for al values of D (P>0.05). Conclusions The difference between initial arteriole and venule damage could be explained by the threefold higher absorption coefficient at 595 nm in (oxygen-poor!) arterioles. In human patients, PWS consist of ectatic venules (characterized by higher absorption), so that these considerations favor the use of 595-nm irradiation for laser photothermolysis. For optimal treatment of PWS it is proposed that tp be between 0.1 and 1.5 milliseconds. This is based on a modified relaxation time ,d,, defined as the time required for heat conduction into the full thickness of the vessel wall, which is assumed to have a thickness ,D ,,0.1D. The corresponding ,d, will be a factor of about six smaller than given in the literature. For vessels with D between 30 and 300 ,m, ,d, ranges from 0.1 to 1.5 milliseconds. Lasers Surg. Med. 30:160,169, 2002. © 2002 Wiley-Liss, Inc. [source] 3D MR angiography of intratumoral vasculature using a novel macromolecular MR contrast agentMAGNETIC RESONANCE IN MEDICINE, Issue 3 2001Hisataka Kobayashi Abstract Noninvasive methods to visualize blood flow in the intratumoral vasculature have not previously been studied. In the present study, the use of a novel intravascular MR contrast agent with a generation-6 polyamidoamine dendrimer core (G6-(1B4M-Gd)192; MW: 175kD) was investigated, and the vasculature in experimental tumors was visualized using 3D MR angiography (MRA). Xenografted tumors in nude mice of two different histologies,KT005 (human osteogenic sarcoma) and LS180 (human colon carcinoma),were used to obtain 3D MRA using G6-(1B4M-Gd)192 and Gd-DTPA. The contrast MR sectional images were correlated with the corresponding histological sections. The intratumoral vasculature in the KT005 tumor was clearly visualized by 3D MRA, which became more evident with the growth of the tumor xenograft. In contrast, the intratumoral vasculature in the LS180 tumor was sparser and much less developed than that in KT005 tumors. Blood vessels with a diameter as small as 100 ,m based on histology were visualized using 0.033 mmol Gd/kg of G6-(1B4M-Gd)192. In conclusion, intratumoral vasculature with a 100-,m diameter was visualized better using 3D MRA with G6-(1B4M-Gd)192 than with Gd-DTPA. Magn Reson Med 46:579,585, 2001. © 2001 Wiley-Liss, Inc. [source] The Effects of Hemodynamic Force on Embryonic DevelopmentMICROCIRCULATION, Issue 3 2010JAMES C. CULVER Microcirculation (2010) 17, 164,178. doi: 10.1111/j.1549-8719.2010.00025.x Abstract Blood vessels have long been known to respond to hemodynamic force, and several mechanotransduction pathways have been identified. However, only recently have we begun to understand the effects of hemodynamic force on embryonic development. In this review, we will discuss specific examples illustrating the role of hemodynamic force during the development of the embryo, with particular focus on the development of the vascular system and the morphogenesis of the heart. We will also discuss the important functions served by mechanotransduction and hemodynamic force during placentation, as well as in regulating the maintenance and division of embryonic, hematopoietic, neural, and mesenchymal stem cells. Pathological misregulation of mechanosensitive pathways during pregnancy and embryonic development may contribute to the occurrence of cardiovascular birth defects, as well as to a variety of other diseases, including preeclampsia. Thus, there is a need for future studies focusing on better understanding the physiological effects of hemodynamic force during embryonic development and their role in the pathogenesis of disease. [source] Evaluating anatomical research in surgery: a prospective comparison of cadaveric and living anatomical studies of the abdominal wallANZ JOURNAL OF SURGERY, Issue 12 2009Warren M. Rozen Abstract Background:, Cadaveric research has widely influenced our understanding of clinical anatomy. However, while many soft-tissue structures remain quiescent after death, other tissues, such as viscera, undergo structural and functional changes that may influence their use in predicting living anatomy. In particular, our understanding of vascular anatomy has been based upon cadaveric studies, in which vascular tone and flow do not match the living situation. Methods:, An angiographic analysis of the abdominal wall vasculature was performed using plain film and computed tomography angiography in 60 cadaveric hemi-abdominal walls (from 31 cadavers) and 140 living hemi-abdominal walls (in 70 patients). The deep inferior epigastric artery (DIEA) and all of its perforating branches larger than 0.5 mm were analysed for number, calibre and location. Results:, Both large, named vessels and small calibre vessels show marked differences between living anatomy and cadaveric specimens. The DIEA was of larger diameter (4.2 mm versus 3.1 mm, P < 0.01) and had more detectable branches in the cadaveric specimens. Perforators were of greater calibre (diameter 1.5 mm versus 0.8 mm, P < 0.01) and were more plentiful (16 versus 6, P < 0.01) in cadaveric specimens. However, the location of individual vessels was similar. Conclusions:, Cadaveric anatomy displays marked differences to in vivo anatomy, with the absence of living vascular dynamics affecting vessel diameters in cadaveric specimens. Blood vessels are of greater measurable calibre in cadaveric specimens than in the living. Consequently, cadaveric anatomy should be interpreted with consideration of post-mortem changes, while living anatomical studies, particularly with the use of imaging technologies, should be embraced in anatomical research. [source] Abnormal Endothelial Tight Junctions in Active Lesions and Normal-appearing White Matter in Multiple SclerosisBRAIN PATHOLOGY, Issue 2 2002Jonnie Plumb Blood-brain barrier (BBB) breakdown, demonstrable in vivo by enhanced MRI is characteristic of new and expanding inflammatory lesions in relapsing-remitting and chronic progressive multiple sclerosis (MS). Subtle leakage may also occur in primary progressive MS. However, the anatomical route(s) of BBB leakage have not been demonstrated. We investigated the possible involvement of interendothelial tight junctions (TJ) by examining the expression of TJ proteins (occludin and ZO-1) in blood vessels in active MS lesions from 8 cases of MS and in normal-appearing white (NAWM) matter from 6 cases. Blood vessels (10,50 per frozen section) were scanned using confocal laser scanning microscopy to acquire datasets for analysis. TJ abnormalities manifested as beading, interruption, absence or diffuse cytoplasmic localization of fluorescence, or separation of junctions (putative opening) were frequent (affecting 40% of vessels) in oil-red-O-positive active plaques but less frequent in NAWM (15%), and in normal (<2%) and neurological controls (6%). Putatively "open" junctions were seen in vessels in active lesions and in microscopically inflamed vessels in NAWM. Dual fluorescence revealed abnormal TJs in vessels with pre-mortem serum protein leakage. Abnormal or open TJs, associated with inflammation may contribute to BBB leakage in enhancing MRI lesions and may also be involved in subtle leakage in non-enhancing focal and diffuse lesions in NAWM. BBB disruption due to tight junctional pathology should be regarded as a significant form of tissue injury in MS, alongside demyelination and axonopathy. [source] Circulating bone marrow-derived endothelial precursor cells contribute to neovascularization in diabetic epiretinal membranesACTA OPHTHALMOLOGICA, Issue 2009A ABU EL ASRAR Purpose Role of vasculogenesis, recruitment and differentiation of circulating bone marrow-derived endothelial precursor cells into mature endothelium, in proliferative diabetic retinopathy (PDR) remains undefined. We investigated the presence of bone marrow-derived endothelial precursor cells and the expression of the chemotactic pathway SDF-1/CXCL12?CXCR4 in PDR epiretinal membranes. Methods Membranes from 8 patients with active PDR and 9 patients with inactive PDR were studied by immunohistochemistry using antibodies against CD133, vascular endothelial growth factor receptor-2 (VEGFR-2), CD14, SDF-1 and CXCR4. Results Blood vessels expressed CD133, VEGFR-2, CD14, SDF-1 and CXCR4 in 10, 10, 10, 7 and 7 out of 17 membranes, respectively. There were significant correlations between number of blood vessels expressing CD34 and number of blood vessels expressing CD133 (rs=0.646; p=0.005), VEGFR-2 (rs=0.704; p=0.002), CD14 (rs=0.564; p=0.018), and SDF-1 (rs=0.577; p=0.015). Stromal cells in close association with blood vessels expressed CD133, VEGFR-2, CD14, and CXCR4 in 10, 12, 13, and 14 membranes, respectively. Number of blood vessels expressing CD133 (p=0.013), VEGFR-2 (p=0.005), CD14 (p=0.008) and SDF-1 (p=0.005), and stromal cells expressing CD133 (p=0.003), VEGFR-2 (p=0.013) and CD14 (p=0.002) was significantly higher in active membranes than in inactive membranes. Conclusion Bone marrow-derived CD133+ endothelial progenitor cells and CD14+ monocytes may contribute to vasculogenesis in PDR. [source] Expression of advanced glycation end products and related molecules in diabetic fibrovascular epiretinal membranesCLINICAL & EXPERIMENTAL OPHTHALMOLOGY, Issue 1 2010Ahmed M Abu El-Asrar MD PhD Abstract Purpose:, To investigate associations between expressions of advanced glycation end products (AGEs), transforming growth factor-, (TGF-,), tumour necrosis factor-, (TNF-,) and integrins and correlations between their expression and level of vascularization and proliferative activity in diabetic fibrovascular epiretinal membranes. Methods:, Membranes from eight patients with active proliferative diabetic retinopathy and nine patients with inactive proliferative diabetic retinopathy were studied by immunohistochemistry. Results:, Blood vessels expressed AGEs, TGF-,, TNF-, and ,v,3 integrin in 5, 13, 8 and 8 membranes, respectively. Stromal cells expressed AGEs, TNF-, and ,v,3 integrin in 15, 13 and 3 membranes, respectively. There was no immunoreactivity for ,v,5, ,5,1 and ,2,1 integrins. There were significant correlations between number of blood vessels expressing CD34 and number of blood vessels expressing AGEs (rs = 0.496; P = 0.043), TGF-, (rs = 0.777; P < 0.001) and TNF-, (rs = 0.699; P = 0.002). There were significant correlations between number of blood vessels expressing AGEs and number of blood vessels expressing TGF-, (rs = 0.532; P = 0.028) and TNF-, (rs = 0.626; P = 0.007). The correlation between number of blood vessels expressing TNF-, and ,v,3 integrin was significant (rs = 0.617; P = 0.008). Number of blood vessels expressing CD34 (P = 0.001), TGF-, (P = 0.006) and TNF-, (P = 0.002) and stromal cells expressing AGEs (P = 0.001) and TNF-, (P = 0.004) were significantly higher in active membranes than in inactive membranes. Conclusion:, Interactions of AGEs, TGF-,, TNF-, and ,v,3 integrin might be involved in pathogenesis of proliferative diabetic retinopathy fibrovascular proliferation. [source] Gene targeted ablation of high molecular weight fibroblast growth factor-2DEVELOPMENTAL DYNAMICS, Issue 2 2009Mohamad Azhar Abstract Fibroblast growth factor-2 (FGF2) is produced as high molecular weight isoforms (HMW) and a low molecular weight isoform (LMW) by means of alternative usage of translation start sites in a single Fgf2 mRNA. Although the physiological function of FGF2 and FGF2 LMW has been investigated in myocardial capillarogenesis during normal cardiac growth, the role of FGF2 HMW has not been determined. Here, we report the generation of FGF2 HMW-deficient mice in which FGF2 HMW isoforms are ablated by the Tag-and-Exchange gene targeting technique. These mice are normal and fertile with normal fecundity, and have a normal life span. Histological, immunohistochemical, and morphometric analyses indicate normal myocardial architecture, blood vessel, and cardiac capillary density in young adult FGF2 HMW-deficient mice. These mice along with the FGF2- and FGF2 LMW-deficient mice that we have generated previously will be very useful for elucidating the differential functions of FGF2 isoforms in pathophysiology of cardiovascular diseases. Developmental Dynamics 238:351,357, 2009. © 2008 Wiley-Liss, Inc. [source] Three-dimensional reconstruction of the mucosa from sequential sections of biopsy specimens of patients with ulcerative colitis: Relationship between crypt structure and vascular architectureDIGESTIVE ENDOSCOPY, Issue 2 2004Hiroo Furukawa Background:, In a previous paper, the stereographic reconstruction of the crypt structure of ulcerative colitis using the RATOCK System was described. The relationship between the blood vessels and the crypt structure is the focus of the current paper, using two kinds of tissue staining color in which the color differs. Stereographic images make the relationship between the crypt structure and blood vessel distribution understandable at a glance. Methods:, The methods used here are identical to those described in a previous paper. In the present paper, five cases of ulcerative colitis (UC) are examined. Biopsy specimens were obtained from the diseased, normal, and transitional zones (the area between the normal and diseased zones) from each patient. Three-dimensional reconstruction was created using TRI for Windows (RATOC System Tokyo, Japan) software. In the present paper, two kinds of dyeing method between H&E and monoclonal antibody staining of the tissue was used. It was proven that the distribution of gland and blood vessel is very clear in the 3-D reconstruction shown. Results:, (i) The blood vessels in the normal zones run parallel to the crypt in a regular manner and are almost identical to one another in diameter. (ii) In the transitional and diseased zones, the blood vessels show no clear direction and produce many branches without any apparent order. The blood vessels are, moreover, irregular in diameter. (iii) In short, clear parallelism is lost in both the transitional and diseased zones. Conclusion:, Stereographic reconstruction of endoscopically obtained biopsy specimens of UC-affected tissues makes it possible to understand at a glance the distribution of blood vessels and their relationship to crypts. The relationship of these was clarified by the combined use of two kinds of dyeing method with three-dimensional reconstruction. [source] Haemosuccus pancreaticus: diagnostic and therapeutic challengesHPB, Issue 4 2009Velayutham Vimalraj Abstract Background:, Haemosuccus pancreaticus (HP) is a rare cause of upper gastrointestinal bleeding. The objective of our study was to highlight the challenges in the diagnosis and management of HP. Methods:, The records of 31 patients with HP diagnosed between January 1997 and June 2008 were reviewed retrospectively. Results:, Mean patient age was 34 years (11,55 years). Twelve patients had chronic alcoholic pancreatitis, 16 had tropical pancreatitis, two had acute pancreatitis and one had idiopathic pancreatitis. Selective arterial embolization was attempted in 22 of 26 (84%) patients and was successful in 11 of the 22 (50%). Twenty of 31 (64%) patients required surgery to control bleeding after the failure of arterial embolization in 11 and in an emergent setting in nine patients. Procedures included distal pancreatectomy and splenectomy, central pancreatectomy, intracystic ligation of the blood vessel, and aneurysmal ligation and bypass graft in 11, two, six and one patients, respectively. There were no deaths. Length of follow-up ranged from 6 months to 10 years. Conclusions:, Upper gastrointestinal bleeding in a patient with a history of chronic pancreatitis could be caused by HP. Diagnosis is based on investigations that should be performed in all patients, preferably during a period of active bleeding. These include upper digestive endoscopy, contrast-enhanced computed tomography (CECT) and selective arteriography of the coeliac trunk and superior mesenteric artery. Contrast-enhanced CT had a high positive yield comparable with that of selective angiography in our series. Therapeutic options consist of selective embolization and surgery. Endovascular treatment can control unstable haemodynamics and can be sufficient in some cases. However, in patients with persistent unstable haemodynamics, recurrent bleeding or failed embolization, surgery is required. [source] Influence of the surface on thrombin generationINTERNATIONAL JOURNAL OF LABORATORY HEMATOLOGY, Issue 4 2008T. W. STIEF Summary Thrombin generation depends on the surface of the blood vessel or container. With a new ultra-sensitive and -specific thrombin assay the surface-dependent thrombin generation was quantified. Citrated blood or plasma was preincubated for 1 h (37 °C). Citrated blood, plasma, or plasma with 0,10 g/l hemoglobin,erythrocyte microparticles (Hb,MP) were preincubated at 23 °C or at 37 °C. Plasma samples (50 ,l) were recalcified in polystyrol (PS) wells and incubated for different coagulation reaction times (CRT). Final supramolar arginine concentrations, 0.1% Triton X 100, and chromogenic thrombin substrate concentrations in the onefold km,range were added and the linear ,A/t was measured in the recalcified coagulation activity assay (RECA). Aprotinin or corn trypsin inhibitor were added. (i) Recalcification of plasma (in different monovettes) pre-incubated for 1 h (37 °C) generated the following thrombin activities after 7 min (37 °C): 0.74 IU/ml (polypropylene (PP)-citrate), 0.39 IU/ml (PP-EDTA), 0.06 IU/ml (PP-heparin), 1.38 IU/ml (PS), 0.63 IU/ml (1 ml volume PP), 0.13 IU/ml (15 ml volume PP), and 3.62 IU/ml (glass). (ii) Recalcification of preincubated whole blood generated up to about fivefold more thrombin. (iii) Thrombin generation is proportional to the plasmatic concentration of Hb,MP, 10 g/l Hb,MP generating about 4 IU/ml thrombin within 20 min CRT. (iv) The IC50 of aprotinin and corn typsin inhibitor on thrombin generation in RECA are about 2 KIU/ml and about 1 U/ml, respectively. The reaction wall, the preincubation temperature, and hemolysis influences thrombin generation. The RECA allows to diagnose the prothrombotic capacity of any material. [source] Cell and molecular mechanisms of insulin-induced angiogenesisJOURNAL OF CELLULAR AND MOLECULAR MEDICINE, Issue 11-12 2009Yan Liu Abstract Angiogenesis, the development of new blood vessel from pre-existing vessels, is a key process in the formation of the granulation tissue during wound healing. The appropriate development of new blood vessels, along with their subsequent maturation and differentiation, establishes the foundation for functional wound neovasculature. We performed studies in vivo and used a variety of cellular and molecular approaches in vitro to show that insulin stimulates angiogenesis and to elucidate the signalling mechanisms by which this protein stimulates microvessel development. Mice skin injected with insulin shows longer vessels with more branches, along with increased numbers of associated ,-smooth muscle actin-expressing cells, suggesting the appropriate differentiation and maturation of the new vessels. We also found that insulin stimulates human microvascular endothelial cell migration and tube formation, and that these effects occur independently of VEGF/VEGFR signalling, but are dependent upon the insulin receptor itself. Downstream signalling pathways involve PI3K, Akt, sterol regulatory element-binding protein 1 (SREBP-1) and Rac1; inhibition of these pathways results in elimination of endothelial cell migration and tube formation and significantly decreases the development of microvessels. Our findings strongly suggest that insulin is a good candidate for the treatment of ischaemic wounds and other conditions in which blood vessel development is impaired. [source] Anatomic variability in superficial blood vessel and lymphatic vessel densityJOURNAL OF CUTANEOUS PATHOLOGY, Issue 10 2010Keith Duffy No abstract is available for this article. [source] Toward an Implantable Wireless Cardiac Monitoring Platform Integrated with an FDA-Approved Cardiovascular StentJOURNAL OF INTERVENTIONAL CARDIOLOGY, Issue 5 2009ERIC Y. CHOW Ph.D. Continuous monitoring of blood pressure from a minimally invasive device in the pulmonary artery can serve as a diagnostic and early warning system for cardiac health. The foremost challenge in such a device is the wireless transfer of data and power from within the blood vessel to an external device while maintaining unrestricted flow through the artery. We present a miniaturized system, which is attached to the outer surface of a regular or drug-eluting FDA-approved stent. When expanded, the stent maintains a patent vessel lumen while allowing contact between the electronic sensors and the blood supply. The stent-based antenna can be used for both wireless telemetry and power transfer for the implanted electronics. Using the stent platform as both a radiating antenna and a structural support allows us to take advantage of an FDA-approved device whose safety and surgical procedure are well established. The electronics package has been reduced to an area of less than 1 mm2, with a thickness under 300 ,m. A minimally invasive implantation procedure allows the delivery of the stent-based implant in nearly any major vessel of the body. This article describes an initial prototype with two stents configured as a single dipole, a 2.4-GHz transmitter microchip, and a battery, and validates transcutaneous transmission through ex vivo and in vivo porcine studies. The results demonstrate the feasibility of a stent-based wireless platform for continuous monitoring of blood pressure. [source] Phase-contrast X-ray imaging with a large monolithic X-ray interferometerJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2000Tohoru Takeda To increase the field of view for large objects in phase-contrast X-ray imaging, a large monolithic X-ray interferometer has been fabricated using an available silicon ingot of diameter 10,cm. A performance study of this interferometer has been carried out using a synchrotron X-ray source. The view size of the interference pattern obtained with this interferometer was 25,mm wide and 15,mm high and its visibility was 79%. Various structures of a sliced human hepatocellular carcinoma were identified as necrosis, hemorrhagic necrosis, normal liver tissue and blood vessel. The performance of this interferometer was sufficient for phase-contrast X-ray imaging. [source] Mathematical modeling of 980-nm and 1320-nm endovenous laser treatmentLASERS IN SURGERY AND MEDICINE, Issue 3 2007Serge R. Mordon PhD Abstract Background and Objectives Endovenous laser treatment (ELT) has been proposed as an alternative in the treatment of reflux of the great saphenous vein (GSV) and small saphenous vein (SSV). Numerous studies have since demonstrated that this technique is both safe and efficacious. ELT was presented initially using diode lasers of 810 nm, 940 nm, and 980 nm. Recently, a 1,320-nm Nd:YAG laser was introduced for ELT. This study aims to provide mathematical modeling of ELT in order to compare 980 nm and 1,320 nm laser-induced damage of saphenous veins. Study Design/Materials and Methods The model is based on calculations describing light distribution using the diffusion approximation of the transport theory, the temperature rise using the bioheat equation, and the laser-induced injury using the Arrhenius damage model. The geometry to simulate ELT was based on a 2D model consisting of a cylindrically symmetric blood vessel including a vessel wall and surrounded by an infinite homogenous tissue. The mathematical model was implemented using the Macsyma-Pdease2D software (Macsyma, Inc., Arlington, MA). Calculations were performed so as to determine the damage induced in the intima tunica, the externa tunica and inside the peri-venous tissue for 3 mm and 5 mm vessels (considered after tumescent anesthesia) and different linear endovenous energy densities (LEED) usually reported in the literature. Results Calculations were performed for two different vein diameters: 3 mm and 5 mm and with LEED typically reported in the literature. For 980 nm, LEED: 50 to 160 J/cm (CW mode, 2 mm/second pullback speed, power: 10 W to 32 W) and for 1,320 nm, LEED: 50 to 80 J/cm (pulsed mode, pulse duration 1.2 milliseconds, peak power: 135 W, repetition rate 30 Hz to 50 Hz). Discussion and Conclusion Numerical simulations are in agreement with LEED reported in clinical studies. Mathematical modeling shows clearly that 1,320 nm, with a better absorption by the vessel wall, requires less energy to achieve wall damage. In the 810,1,320-nm range, blood plays only a minor role. Consequently, the classification of these lasers into hemoglobin-specific laser wavelengths (810, 940, 980 nm) and water-specific laser wavelengths (1,320 nm) is inappropriate. In terms of closure rate, 980 nm and 1,320 nm can lead to similar results and, as reported by the literature, to similar side effects. This model should serve as a useful tool to simulate and better understand the mechanism of action of the ELT. Lasers Surg. Med. 39:256,265, 2007. © 2007 Wiley-Liss, Inc. [source] Computerised morphometric study of the paraurethral tissue in young and elderly womenNEUROUROLOGY AND URODYNAMICS, Issue 6 2002M. Verelst Abstract Aim. Changes in structural support of the urethra and bladder neck have been proposed to be among the most important factors in the pathogenesis of stress urinary incontinence. In this context, we histologically investigated the paraurethral area in continent women to quantify the relative distribution of connective tissue, smooth muscle, vessels, nerves, and striated muscle. Previously published literature gives only descriptive evaluations of the relative distribution of these tissue components. Methods. We used a computerised morphometric method, which allowed us to estimate the paraurethral tissue distribution in a more objective way. The material was obtained by dissection during autopsy in five premenopausal and five postmenopausal women. Results. Paraurethral tissue consisted of 56% connective tissue (SD, 5%), 30% smooth muscle (SD, 5%), 11% blood vessel (SD, 6%), 2% striated muscle (SD, 3%), and 1% nerves (SD, 1%). We also found that the distribution of different tissue components along the length of the urethra did not differ at a statistically significant level. Furthermore, there was a statistically significant difference in the amount of connective tissue and blood vessels in the postmenopausal women compared with the premenopausal women. Conclusions. The present study shows that the paraurethral area is built of heterogeneous tissue with small changes in its composition along the course of urethra. Increase in connective tissue was found to be the dominating change in the process of ageing. Neurourol. Urodynam. 21:529,533, 2002. © 2002 Wiley-Liss, Inc. [source] Case of acute ileus caused by a spirurina larvaPATHOLOGY INTERNATIONAL, Issue 9 2004Toshihiko Miyake A growing body of clinical cases suggests that a kind of nematode larva, type X larva of the suborder Spirurina that inhabits firefly squids (Watasenia scintillans, or ,Hotaru-ika' in Japanese), can cause acute ileus in humans. However, the larva itself has rarely been found in the wall of the obstructed intestine. We describe here a case of acute ileus, in which a type X spirurina larva was found histologically. A 60-year-old Japanese man suffered from acute abdomen, and an emergency laparotomy revealed a marked stenosis of the ileum. Histological study of the surgically resected ileum showed severe eosinophilic enteritis and a nematode larva. The morphological features of this larva were identical to those of the type X spirurina larva. Interestingly, the larva that was found existed within a small blood vessel, suggesting that the larva migrans of type X spirurina can take place via vasculature. The patient in the present case did not recall ingesting raw squids prior to the onset of his disease. Hence, this indicates that even if the ingestion of raw firefly squids is uncertain, spirurina infection should be included in the differential diagnosis of acute ileus or eosinophilic enteritis. [source] Heuristic problems in defining the three-dimensional arrangement of the ventricular myocytesTHE ANATOMICAL RECORD : ADVANCES IN INTEGRATIVE ANATOMY AND EVOLUTIONARY BIOLOGY, Issue 6 2006Robert H. Anderson Abstract There is lack of consensus concerning the three-dimensional arrangement of the myocytes within the ventricular muscle masses. Bioengineers are seeking to model the structure of the heart. Although the success of such models depends on the accuracy of the anatomic evidence, most of them have been based on concepts that are far from anatomical reality, which ignore many significant previous accounts of anatomy presented over the past 400 years. During the 19th century, Pettigrew emphasized that the heart was built on the basis of a modified blood vessel rather than in the form of skeletal muscles. This fact was reemphasized by Lev and Simkins as well as Grant in the 20th century, but the caveats listed by these authors have been ignored by proponents of two current concepts, which state either that the myocardium is arranged in the form of a "unique myocardial band," or that the walls of the ventricles are sequestrated in uniform fashion by laminar sheets of fibrous tissue extending from epicardium to endocardium. These two concepts are themselves incompatible and are further at variance with the majority of anatomic studies, which have emphasized the regional heterogeneity to be found in the three-dimensional packing of the myocytes within a supporting matrix of fibrous tissue. We reemphasize the significance of this three-dimensional muscular mesh, showing how the presence of intruding aggregates of myocytes extending in oblique transmural fashion also contends against the notion that all myocytes are orientated with their long axes parallel to the epicardial and enodcardial surfaces. Anat Rec Part A 288A:579,586, 2006. © 2006 Wiley-Liss, Inc. [source] Skeleton-based active catheter navigationTHE INTERNATIONAL JOURNAL OF MEDICAL ROBOTICS AND COMPUTER ASSISTED SURGERY, Issue 2 2009Yili Fu Abstract Background The emergence of the active catheter has prompted the development of catheterization in minimally invasive surgery. However, it is still operated using only the physician's vision; information supplied by the guiding image and tracking sensors has not been fully utilized. Methods In order to supply the active catheter with more useful information for automatic navigation, we extract the skeleton of blood vessels by means of an improved distance transform method, and then present the crucial geometric information determining navigation. With the help of tracking sensors' position and pose information, two operations, advancement in the proximal end and direction selection in the distal end, are alternately implemented to insert the active catheter into a target blood vessel. Results The skeleton of the aortic arch reconstructed from slice images is extracted fast and automatically. A navigation path is generated on the skeleton by manually selecting the start and target points, and smoothed with the cubic cardinal spline curve. Crucial geometric information determining navigation is presented, as well as requirements for the catheter entering the target blood vessel. Using a shape memory alloy active catheter integrated with magnetic sensors, an experiment is carried out in a vascular model, in which the catheter is successfully inserted from the ascending aorta, via the aortic arch, into the brachiocephalic trunk. Conclusions The navigation strategy proposed in this paper is feasible and has the advantage of increasing the automation of catheterization, enhancing the manoeuvrability of the active catheter and providing the guiding image with desirable interactivity. Copyright © 2009 John Wiley & Sons, Ltd. [source] 4144: Retinal blood vessel phenotyping in miceACTA OPHTHALMOLOGICA, Issue 2010J RUBERTE Purpose In the retina there is a compromise between optimal visual function and optimal oxygenation. Retinal blood vessels have a relative sparse distribution and their size is small in order to minimise optical interference with the light path. Hence, the blood flow volume in the retina is relatively low. This fact, together with the high oxygen consumption of the retinal tissue, could facilitate the development of retinal hypoxia and subsequent retinopathy when the vascular bed is altered. Thus, the analysis of retinal blood vessel must be a crucial step during retinal phenotyping in mutant mice. Methods Different technologies and methods have been used in order to analyze structure, distribution and function of retinal blood vessels, among others: retinal digest preparations, retinal whole mount immunohistochemistry, transmission and scanning electron microscopy, fluorescein and Mercox vascular injections and scanner laser ophthalmoscopy. Results In our laboratory, morphological and topographic alterations of retinal blood vessels in Bmi1 and Sirt1 knockout mice, as well as in IGF-1 and IL-10 transgenic mice, have been observed and documented Conclusion The mouse genome is fully sequenced. 99% of the coding genes present in man are also present in mouse. Moreover, the majority of disease-related genes have been conserved since the emergence of the bony fishes about 400 million years ago. These facts and the development during the last two decades of an extensive toolbox to study the functional effects of genetic variation in mice, make them the ideal model organism for the study of human eye diseases. In this sense, morphological and functional analyses of retinal blood vessel in mutant mice could help to understand vascular gene-based mechanisms that lead to retinopathy [source] Three-dimensional CT angiography: A new technique for imaging microvascular anatomyCLINICAL ANATOMY, Issue 2 2007Ashley P. Tregaskiss Abstract To date there has been no satisfactory research method for imaging microvascular anatomy in three dimensions (3D). In this article we present a new technique that allows both qualitative and quantitative examination of the microvasculature in 3D. In 10 fresh cadavers (7 females, 3 males, mean age 68 years), selected arteries supplying the abdominal wall and back were injected with a lead oxide/gelatin contrast mixture. From these regions, 30 specimens were dissected free and imaged with a 16-slice spiral computed tomographic (CT) scanner. Using three-dimensional CT (3D-CT) angiography, reconstructions of the microvasculature of each specimen were produced and examined for their qualitative content. Two calibration tools were constructed to determine (1) the accuracy of linear measurements made with CT software tools, and (2) the smallest caliber blood vessel that is reliably represented on 3D-CT reconstructions. Three-dimensional CT angiography produced versatile, high quality angiograms of the microvasculature. Correlation between measurements made with electronic calipers and CT software tools was very high (Lin's concordance coefficient, 0.99 (95% CI 0.99,0.99)). The finest caliber of vessel reliably represented on the 3D-CT reconstructions was 0.4 mm internal diameter. In summary, 3D-CT angiography is a simple, accurate, and reproducible method that imparts a much improved perception of anatomy when compared with existing research methods. Measurement tools provide accurate quantitative data to aid vessel mapping and preoperative planning. Further work will be needed to explore the full utility of 3D-CT angiography in a clinical setting. Clin. Anat. 20:116,123, 2007. © 2006 Wiley-Liss, Inc. [source] Adenosine A1 receptors and vascular reactivityACTA PHYSIOLOGICA, Issue 2 2010Y. Wang Abstract Aim:, Blood pressure is higher in A1 receptor knock-out (A1R,/,) mice than in wild type litter mates (A1R+/+) and we have examined if this could be related to altered vascular functions. Methods:, Contraction of aortic rings and mesenteric arteries were examined. To examine if the adenosine A1 receptor-mediated contraction of aortic muscle was functionally important we examined pulse pressure (PP) and augmentation index (AIX) using a sensor that allows measurements of rapid pressure transients. Results:, Contraction of aortic rings to phenylephrine and relaxation to acetylcholine were similar between genotypes. The non-selective adenosine receptor agonist N -ethyl carboxamido adenosine (NECA) enhanced the contractile response, and this was eliminated in aortas from A1R,/, mice. However, in mesenteric arteries no contractile response was seen and adenosine-mediated relaxation was identical between studied genotypes. A2B adenosine receptors, rather than A2A receptors, may be mainly responsible for the vasorelaxation induced by adenosine analogues in the examined mouse vessels. PP was higher in A1R,/, mice, but variability was unaltered. AIX was not different between genotypes, but the NECA-induced fall was larger in A1R,/, mice. Conclusions:, The role of adenosine A1 receptors in regulating vessel tone differs between blood vessels. Furthermore, contractile effects on isolated vessels cannot explain the blood pressure in A1 knock-out mice. The A1 receptor modulation of blood pressure is therefore mainly related to extravascular factors. [source] The role of caveolin-1 in cardiovascular regulationACTA PHYSIOLOGICA, Issue 2 2009A. Rahman Abstract Caveolae are omega-shaped membrane invaginations present in essentially all cell types in the cardiovascular system, and numerous functions have been ascribed to these structures. Caveolae formation depends on caveolins, cholesterol and polymerase I and transcript release factor-Cavin (PTRF-Cavin). The current review summarizes and critically discusses the cardiovascular phenotypes reported in caveolin-1-deficient mice. Major changes in the structure and function of heart, lung and blood vessels have been documented, suggesting that caveolae play a critical role at the interface between blood and surrounding tissue. According to an emerging paradigm, many of these changes are secondary to uncoupling of endothelial nitric oxide synthase. Thus, nitric oxide synthase not only synthesizes more nitric oxide in the absence of caveolin-1, but also more superoxide with potential pathogenic consequences. It is further argued that the vasodilating drive from increased nitric oxide production in caveolin-1-deficient mice is balanced by changes in the vascular media that favour increased dynamic resistance regulation. Harnessing the therapeutic opportunities buried in caveolae, while challenging, could expand the arsenal of treatment options in cancer, lung disease and atherosclerosis. [source] Chicken gizzard filamin, retina filamin and cgABP260 are respectively, smooth muscle-, non-muscle- and pan-muscle-type isoforms: Distribution and localization in musclesCYTOSKELETON, Issue 4 2005Kazuyo Ohashi Abstract We determined the full cDNA sequences of chicken gizzard filamin and cgABP260 (chicken gizzard actin-binding protein 260). The primary and secondary structures predicted by these sequences were similar to those of chicken retina filamin and human filamins. Like mammals, chickens have 3 filamin isoforms. Comparison of their amino acid sequences indicated that gizzard filamin, retina filamin, and cgABP260 were the counterparts of human FLNa (filamin a), b, and c, respectively. Antibodies against the actin-binding domain (ABD) of these 3 filamin isoforms were raised in rabbits. Using immunoabsorption and affinity chromatography, we prepared the monospecific antibody against the ABD of each filamin. In immunoblotting, the antibody against the gizzard filamin ABD detected a single band in gizzard, but not in striated muscles or brain. In brain, only the antibody against the retina filamin ABD produced a strong single band. The antibody against the cgABP260 ABD detected a single peptide band in smooth, skeletal, and cardiac muscle. In immunofluorescence microscopy of muscular tissues using these antibodies, the antibody against the gizzard filamin ABD only stained smooth muscle cells, and the antibody against the retina filamin ABD strongly stained endothelial cells of blood vessels and weakly stained cells in connective tissue. The antibody against the cgABP260 ABD stained the Z-lines and myotendinous junctions of breast muscle, the Z-lines and intercalated disks of cardiac muscle, and dense plaques of smooth muscle. These findings indicate that chicken gizzard filamin, retina filamin, and cgABP260 are, respectively, smooth muscle-type, non-muscle-type, and pan-muscle-type filamin isoforms. Cell Motil. Cytoskeleton 61:214,225, 2005. © 2005 Wiley-Liss, Inc. [source] Biocompatibility evaluation of alendronate paste in rat's subcutaneous tissueDENTAL TRAUMATOLOGY, Issue 2 2009Graziela Garrido Mori Therefore, this study aimed to investigate the biocompatibility of experimental alendronate paste in subcutaneous tissue of rats, for utilization in teeth susceptible to root resorption. The study was conducted on 15 male rats, weighing ,180,200 grams. The rats' dorsal regions were submitted to one incision on the median region and, laterally to the incision, the subcutaneous tissue was raised and gently dissected for introduction of two tubes, in each rat. The tubes were sealed at one end with gutta-percha and taken as control. The tubes were filled with experimental alendronate paste. The animals were killed at 7, 15 and 45 days after surgery and the specimens were processed in laboratory. The histological sections were stained with hematoxylin-eosin and analyzed by light microscopy. Scores were assigned to the inflammatory process and statistically compared by the Tukey test (P < 0.05). Alendronate paste promoted severe inflammation process at 7 days, with statistically significant difference compared to the control (P < 0.05%). However, at 15 days, there was a regression of inflammation and the presence of connective tissue with collagen fibers, fibroblasts and blood vessels was observed. After 45 days, it was observed the presence of well-organized connective tissue, with collagen fibers and fibroblasts, and few inflammatory cells. No statistical difference was observed between the control and experimental paste at 15 and 45 days. The experimental alendronate paste was considered biocompatible with subcutaneous tissue of rat. [source] Efficacy of laser Doppler flowmetry for the diagnosis of revascularization of reimplanted immature dog teethDENTAL TRAUMATOLOGY, Issue 2 2001Kallaya Yanpiset Abstract , This study was performed to assess if laser Doppler flowmetry (LDF) is an improved method for the detection of revascularization of replanted teeth. Teeth were extracted and reimplanted under different experimental conditions. LDF readings were taken before extraction and weekly for 3 months. In control teeth, LDF baseline readings were taken and then repeated after the apical blood vessels were cut surgically. At the end of 3 months it was determined radiographically and histologically whether revascularization had occurred, i.e. vitality had returned. Results: LDF readings correctly predicted the pulp status (vital vs. non-vital) in 83.7% of the readings. 73.9% (17 of 23) were correct for the vital teeth and 95% (19 of 20) were correct for the non-vital teeth. Fisher's exact test (2-tail) indicated that there was no significant association between the efficacy of LDF and tooth type (P=0.166), although P2 was the least accurate tooth tested. Wilcoxon's matched-pair signed rank test demonstrated that in the revascularized (vital) teeth, the flux value between the baseline and week 2 dropped significantly (P=0.0001), increased significantly from week 2 to week 4 (P=0.0001) and then decreased steadily until week 12. However, at week 12 the flux was still significantly higher than at week 2 (P=0.010). In the teeth that failed to revascularize, the flux value dropped significantly by weeks 1 and 2 (P=0.004 and P=0.0001, respectively). Flux values did not increase from week 2. A Fast Fourier Transform (FFT) analysis confirmed a pulse of dominant frequency of 2 Hz in the teeth that returned to vitality and the lack thereof in those that stayed non-vital. One tooth in which the flux value evaluation indicated a non-vital tooth but the radiographic/histologic findings showed vital (false negative) possessed a pulse of dominant frequency and proved by this method to have successfully revascularized. [source] Visualized Sclerotherapy of Varicose VeinsDERMATOLOGIC SURGERY, Issue 2010MAMORU KIKUCHI MD BACKGROUND The spread and movement of sclerosant after injection during sclerotherapy is difficult to monitor. OBJECTIVE To develop a new visualization method that allows monitoring of sclerosant dosage and flow during sclerotherapy. METHODS We used a photodynamic eye (PDE) to perform indocyanine green (ICG) imaging. ICG produces strong fluorescence detectable using PDE and allows monitoring of sclerosant spread through blood vessels in real time. We performed visualized sclerotherapy on 50 limbs, comprising high ligation and sclerotherapy (35 limbs), stripping and sclerotherapy (10 limbs), and sclerotherapy alone (5 limbs). RESULTS In all cases, fluorescence imaging of the injected sclerosant was possible. No complications resulted from combining ICG and polidocanol in any of the patients, all of whom received follow-up evaluations at 1 week, 1 month, and 3 months after treatment. CONCLUSIONS Our new method not only avoids the risk of radiation exposure, but also allows for simple observation of sclerosant range of access, determination of the dosage for each lesion, and accurate administration of therapy to target lesions. This method will contribute to further advances in sclerotherapy, given that it allows administration of sclerosant and visual confirmation of optimal injection dosage, speed, and movement of sclerosant after injection. The authors have indicated no significant interest with commercial supporters. [source] |