Structure of venule (Total 5209233 Papers Found)

The microvessels in the buttock skin of 15 patients with long-standing juvenile diabetes were studied both by electron microscopy and three-dimensional (3D) computer reconstruction of a prototypical diabetic postcapillary venule. Endothelial cell gaps were found in postcapillary venules and capillaries, but only in association with an increased deposition of basement membrane-like material in the vascular wall. In parallel with the increased amounts of deposited basement membrane-like material, ...
The present study has examined relationship between cutaneous microvessel injury and adhesion molecule expression on the endothelium by cytokines in NZBxNZWF1 (B/WF1) mice, a model for human systemic lupus erythematosus. In advanced ages associated with overt clinical manifestation, but not in early ages, neutrophils with a minor proportion of monocytes and lymphocytes mainly adhered to the endothelium of capillary and the venule with fragmentation (leukocytoclasis), leading to the vascular inju ...
Preconditioning (PC) with nitric oxide (NO) donors or agents that increase endothelial NO synthase (eNOS) activity 24 h before ischemia-reperfusion (I/R) prevents postischemic leukocyte rolling (LR) and stationary leukocyte adhesion (LA). Since 5'-AMP-activated protein kinase (AMPK) phosphorylates eNOS at Ser1177, resulting in activation, we postulated that AMPK activation may trigger the development of a preconditioned anti-inflammatory phenotype similar to that induced by NO donors. Wild-type ...
Vascular endothelial cells (ECs) form the inner layer of blood vessels and exert crucial functions during immune reactions including coagulation, inflammation, and regulation of innate immunity. Importantly, ECs can interact with T cells in an antigen-specific, i.e., T cell receptor-dependent manner. In this review, we will discuss EC actions and reactions during acute inflammation and focus on the interaction of T cells with ECs at two vascular sites: the high endothelial venule (HEV) of lymph ...
The microvasculature (MV) of serous membranes was compared in rats with spontaneous genetic hypertension (SHR) and in normotensive Wistar rats. The study showed that in hypertension MV lesions had a systemic distribution, as structural changes were present in every MV component (arterioles, precapillaries, capillaries, postcapillaries, venules, lymphatic capillaries, and postcapillaries, nerve fibers); these lesions were generalized, as similar alterations could be found in all serous membranes ...
Immune responses are an important component of the defense of the inner ear against infection. However, immunity appears to be restricted in the labyrinth, as the inflammation associated with immune responses can damage the delicate cellular structures that mediate hearing and balance. When immunoregulation is compromised, either experimentally or through disease, immune-mediated inner ear damage and hearing loss can result. Because there are few resident leukocytes within the labyrinth, immunit ...
The microcirculation of the human colon with special reference to the differences in microvascular architecture between the proximal and distal colon was studied by scanning electron microscopy with vascular corrosion casting technique. The subsurface capillary networks of the ascending colon were honeycomb-like and multi-layered, with an average number of capillary layers per capillary loop of 3.28 +/- 1.10 (mean +/- SD). Whereas, those of the sigmoid colon were almost single-layered, and the a ...
A new method of analyzing in vivo measurements of leukocyte WBC rolling along venular endothelium (EC) has been developed to extract insightful information on the dynamics of WBC–EC bond formation and disruption. The rolling velocity of WBCs was obtained by intravital microscopy of rat mesenteric venules. For the “spontaneous” rolling observed following exteriorization of the mesentery, we estimated that the average distance between clusters of adhesion bonds which tether a rolling cell to ...
Expression of the new G protein-coupled msr/apj receptor in the mouse embryo is restricted to the endothelial layer of the primary blood vessels and the newly forming heart (Mech. Dev. 84 (1999) 199). During development of the retinal vasculature, the msr/apj gene is not expressed throughout the vascular network, indicating a possible relationship between the localization of expression and the acquisition of arterial or venous identity (Mech. Dev. 110 (2002) 183). Here we first established that ...
Hypertension is associated with an increased risk of thrombosis that appears to involve an interaction between the renin-angiotensin system and hemostasis. In this study we determined whether angiotensin II-mediated thrombosis occurs in arterioles and/or venules and assessed the involvement of type 1 (AT₁), type 2 (AT₂), and type 4 (AT₄) angiotensin II receptors, as well as receptors for endothelin 1 and bradykinin 1 and 2 in angiotensin II-enhanced microvascular thrombosis. Thrombus devel ...
In the present study, histopathological analysis of rat mesentery was used to quantify the effect of two anti-inflammatory agents, dexamethasone (Dex) and pertussis toxin (Ptx), on leukocyte migration. The intravenous injection of Dex (1 mg/kg) and Ptx (1,200 ng) 1 h prior to the intraperitoneal injection of the inflammatory stimuli lipopolysaccharide (LPS) or formyl-methionyl-leucyl-phenylalanine (fMLP) significantly reduced the neutrophil diapedesis (LPS: Ptx = 0.86 +/- 0.19 and Dex = 0.35 +/- ...
OBJECTIVE To study the effects of tea polyphenols (TP) on bulbi conjunctiva microcirculation (BCM) and antioxidation in aircrew and find out the proper antioxidant for the health protection of aircrew. METHOD Fourty healthy aircrew were divided into TP group (TP 600 mg/d.po) and control group (placebo) randomly. The effects of TP on microcirculation and antioxidation in aircrew were tested after 20 days. RESULT Red blood cell (RBC) superoxide dismutase (SOD) activity and GSH-PX (Whole blood ...
Despite the information dealing with the differential phenotype and function of the main mouse dendritic cell (DC) subpopulations, namely, CD8alpha(-) and CD8alpha(+) DCs, their origin and involvement in antiviral immune responses in vivo are still largely unknown. To address these issues, this study used the changes occurring in DC subpopulations during the experimental infection by the Swiss (SW) strain of the mouse mammary tumor virus (MMTV). MMTV(SW) induced an 18-fold increase in lymph node ...
A characteristic feature of the synovium early in rheumatoid arthritis (RA) is an increased density of sub-lining capillaries and post-capillary venules within the developing pannus. The number of synovial blood vessels has been found to correlate with synovial cell hyperplasia, mononuclear cell infiltration and the Ritchie articular index of joint tenderness [76]. The stimuli which control the formation of blood vessels in RA have been the subject of a large number of studies, leading to the de ...
PURPOSE To describe the macular deep capillary plexus (DCP) in normal eyes using optical coherence tomography angiography. METHODS Retrospective study including 41 consecutive normal eyes imaged using optical coherence tomography angiography (RTVue XR Avanti; Optovue Inc). Default autosegmentation of the superficial capillary plexus (SCP) and DCP, and manual adjustments of "deep settings" were used to analyze the organization of the normal macular microvascularization and to investigate in viv ...
Pulmonary veno-occlusive disease (PVOD) is a rare entity with non-specific signs and symptoms and is nearly always associated with a dismal prognosis. This review will first consider pulmonary hypertension in general and then will focus on PVOD specifically with particular attention to the pathophysiology of the disease. Classically PVOD is described as a disease primarily involving obstructed venules, with the arterial side of the circulation involved to a lesser degree. This article discusses ...
The reconstruction of the mesenterium microcirculatory bed was performed intravitally in albino rats and cats after biomicrophotograms. The number, length and caliber of arterioles, pericapillary arteriolec, capillaries, postcapillary venules and venules of the mesenterium were measured. According to these data summary indices of the cross section, surface and volume of the vessels of various functional subdivisions of the microcirculatory bed were calculated. The blood volume entering the micro ...
The aim of this study is to report 46 new cases of canine T-cell lymphomas among a series of 140 lymphomas studied by immunophenotyping (incidence 32.8%). According to the updated Kiel classification adapted to the canine species, 13 were classified as low-grade and 33 as high-grade lymphomas. Among the low-grade lymphomas, five were small clear-cell lymphomas, three were pleomorphic small-cell lymphomas, and five mycosis fungoides. Among the high-grade cases, there were 11 pleomorphic mixed-, s ...
The present study was designed to investigate the influences of IFN-alpha on the microcirculatory hemodynamics. The mesenteric microcirculation of male Wistar rats was observed through an intravital fluorescence microscopic system. The leukocyte behavior, RBC velocity, and albumin leakage were monitored simultaneously before and after a continuous infusion of IFN-alpha. In other rats, the oxidant-sensitive fluorescence probe dihydrorhodamine-123 (DHR) fluorescence was observed in the same set up ...
The depth of the lymphoid nodules from gastric epithelial cells depends on the part of the stomach. Closest to the epithelium of small lymphoid nodules located in the body portion and pylorus unlike rumen, bottom and cardia. In the distribution of the depth of localization of nodes has a different picture. Logical drive is high density of nodules and lymphocytes pylorus body portion, unlike other parts of the stomach. In different parts of the stomach is changing the depth of the nodules, the di ...
Nineteen Brown-Norway (BN) rats received intravenous injections of sheep anti-peroxidase (HRP) antibodies. Four BN rats were immunized to HRP. The anti-HRP antibodies were used to trace permeability pathways of large physiological molecules across different vessels of the small intestine. This organ was chosen because of the possibility of convenient “in situ” fixation and for the diversity of vessel types it contains. It was shown that: 1) There were no obvious transendothelial pathways in ...
To elucidate the differential reactivity of pulmonary microvessels in the acini to hypoxia, excessive CO2, and increased H+, we investigated changes in the diameter of precapillary arterioles, postcapillary venules, and capillaries in isolated rat lungs on exposure to normocapnic hypoxia (2% O2), normoxic hypercapnia (15% CO2), and isocapnic acidosis (0.01 mol/L HCl). Microvascular diameters were precisely examined using a real-time confocal laser scanning luminescence microscope coupled to a hi ...
Alzheimer's disease (AD), pathologically characterized by amyloid-β peptide (Aβ) accumulation, neurofibrillary tangle formation, and neurodegeneration, is thought to involve early-onset neurovascular abnormalities. Hitherto studies on AD-associated neurovascular injury have used animal models that exhibit only a subset of AD-like pathologies and demonstrated some Aβ-dependent vascular dysfunction and destabilization of neuronal network. The present work focuses on the early stage of disease p ...
1 The 28 amino acid polypeptide, vasoactive intestinal polypeptide (VIP) induced increased local blood flow when injected intradermally in the rabbit. 2 VIP was found to be even more potent than prostaglandin E2 (PGE2) in increasing blood flow; VIP induced a significant effect at a 1 pmol dose. 3 VIP was shown to be poor in increasing microvascular permeability but very potent in enhancing local oedema induced by two substances which increase permeability, bradykinin and C5a des Arg. VIP was mor ...
Selectin ligands are glycan structures that participate in leukocyte trafficking and inflammation. At least 6 ST3Gal sialyltransferases (I-VI) have been identified that may contribute to selectin ligand formation. However, it is not known which of these sialyltransferases are involved in vivo and whether they may differentially regulate selectin function. We have produced and characterized mice genetically deficient in ST3Gal-I, ST3Gal-II, ST3GalIII, and ST3Gal-IV. Unlike mice bearing severe def ...
The present study investigated the effects of Sinitang (Japanese name: Shigyaku-to--a traditional Chinese medicine), on microcirculatory disturbances induced by endotoxin in rat mesentery. The changes of arteriolar diameter, the velocity of red blood cells in arterioles and venular microcirculation after endotoxin injection (6 mg x kg(-1), i.v.) were observed by videomicroscopy. Mean arterial pressure and heart rate were monitored continuously during the experiments. Sinitang significantly preve ...
Changes in pulmonary microhemodynamics are important variables in a large variety of pathological processes. We used in vivo fluorescent videomicroscopy of the subpleural microvasculature in mechanically ventilated rats to directly monitor microvascular flow velocity (FV) and shear rate in pulmonary arterioles, capillaries, and venules in healthy rats and in septic rats 20 h after cecal ligation and puncture (CLP). Observations were made through a small thoracotomy after injection of fluorescent ...
Leukocyte rolling is an important step for the successful recruitment of leukocytes into tissue and occurs predominantly in inflamed microvessels and in high endothelial venules of secondary lymphoid organs. Leukocyte rolling is mediated by a group of C-type lectins, termed selectins. Three different selectins have been identified - P-, E- and L-selectin - which recognize and bind to crucial carbohydrate determinants on selectin ligands. Among selectin ligands, P-selectin glycoprotein ligand-1 i ...
Three different stable lipoxin A4 (LXA4) analogs (i.e., 16-phenoxy-LXA4-Me, 15-cyclohexyl-LXA4-Me, and 15-R/S-methyl-LXA4-Me) were studied for their ability to modulate leukocyte-endothelial cell interactions in the rat mesenteric microvasculature. Superfusion of the rat mesentery with 50 micromol/liter NG-nitro-L-arginine methyl ester (L-NAME) caused a significant, time-dependent increase in leukocyte rolling (56 +/- 8 cells/min; P < 0.01 vs. control) and leukocyte adherence (12.5 +/- 1. 2 c ...
BACKGROUND Microvascular reperfusion failure of splanchnic organs is a crucial hallmark in organ damage induced by hemorrhagic shock, which should be prevented by a resuscitation solution. Because the vasoactive properties of the hemoglobin-based oxygen carrier diaspirin cross-linked hemoglobin (DCLHb) could adversely influence restoration of pancreatic capillary perfusion during resuscitation, the authors investigated its effects on the microcirculation of the rat pancreas in comparison with wh ...
The recognition of angiodysplasia either at the time of surgery or at the time of routine gross and microscopic examination has often been difficult. Until now the primary methodology used in defining the lesion has been the intravascular injection of radiopaque dyes and other compounds. This technique, however, is prohibitively time consuming and expensive, and does not encourage routine use in surgical pathology practice. We report two cases of angiodysplasia, both occurring in unlikely areas, ...
Tonsillar polyps are nonneoplastic lesions usually composed of variable amounts of lymphoid and vascular and connective tissues. All of them are generally assumed to be hamartomatous proliferations, but the profile of vascular and connective components has yet to be explored. The vascular system of the tonsils is complex and includes highly specialized structures (i.e., high endothelial venules (HEVs)) involved in lymphocyte homing into lymphoid tissues. In 14 tonsillar polyps and 26 control ton ...
BACKGROUND Cardio-thoracic surgery with the use of extracorporeal circulation may lead to an impairment of splanchnic perfusion. The aim of this study was to investigate the effect of dopexamine on gastrointestinal microvascular perfusion failure due to extracorporeal circulation. METHODS Twenty landrace pigs served as laboratory animals. A loop of the terminal ileum was exteriorized for microscopic observation. In 13 animals a partial left-heart bypass (pLHB), with a non-pulsatile pump flow o ...
A 68-year-old man with a history of hypertension and ischaemic heart disease was admitted for congestive heart failure in May 2011. The patient had pancytopenia and underwent an abdominal ultrasound to look for splenomegaly. Ultrasound showed that the liver echotexture was diffusely heterogeneous. The walls of portal venules were hyperechoic and thickened, suggestive of periportal fibrosis (Fig 1). Multiple thickened echogenic septae were noted outlining polygonal areas of relatively normal-appe ...
Inducible cell adhesion molecule 110 (INCAM-110), is a 110-kd adhesion receptor for lymphocytes and monocytes identified on cytokine-activated endothelium. Using immunoperoxidase techniques, little or no INCAM-110 was detected on endothelium in normal human tissues. In contrast, INCAM-110 was expressed in postcapillary venules in a variety of active inflammatory processes. In acute appendicitis, INCAM-110 was found coincident with strong expression of endothelial leukocyte adhesion molecule 1 (E ...
Glucagon-like peptide-1 (GLP-1) is a proglucagon-derived hormone with cellular protective actions. We hypothesized that GLP-1 would protect the endothelium from injury during inflammation. Our aims were to determine the: (1) effect of GLP-1 on basal microvascular permeability, (2) effect of GLP-1 on increased microvascular permeability induced by lipopolysaccaride (LPS), (3) involvement of the GLP-1 receptor in GLP-1 activity, and (4) involvement of the cAMP/PKA pathway in GLP-1 activity. Microv ...
In muscle microcirculation, short periods of ischemia followed by reperfusion are known to upregulate leukocyte and endothelial adhesion molecules, but little is known about leukocyte adherence and ICAM-1 expression during chronic ischemia or any likely effect of muscle activity which is recommended in chronic ischemia due to peripheral arterial disease. Leukocyte rolling and stationary adhesion were observed in post-capillary venules in ischemic and contralateral rat extensor digitorum longus ( ...
Nonsteroidal anti-inflammatory drugs are known to attenuate the effects of some antihypertensive agents. However, the effect these drugs have on leukocyte migration when combined with antihypertensive agents has not been studied. To investigate this effect, we treated spontaneously hypertensive rats with saline, diclofenac, enalapril, or diclofenac combined with enalapril and observed leukocyte-endothelium interaction. Blood pressure was increased by diclofenac, reduced by enalapril and reduced ...
In the paracortex of the lymph node (LN), T zone fibroblastic reticular cells (TRCs) orchestrate an immune response by guiding lymphocyte migration both physically, by creating three-dimensional (3D) cell networks, and chemically, by secreting the chemokines CCL19 and CCL21 that direct interactions between CCR7-expressing cells, including mature dendritic cells and naive T cells. TRCs also enwrap matrix-based conduits that transport fluid from the subcapsular sinus to high endothelial venules, a ...
Intracellular electrical recordings were made from arterioles and venules of the cat gastric submucosa. Spontaneous rhythmic fluctuations of the membrane potential were recorded in 54% of the venular preparations. Arteriolar cells showed no spontaneous activity. Excitatory junction potentials were recorded in arterioles but not venules after single shocks to the perivascular nerves. The amplitude of the excitatory junction potential was decreased in the presence of alpha-blockers. Repetitive sti ...
Elevated cholesterol levels promote proinflammatory and prothrombogenic responses in venules and impaired endothelium-dependent arteriolar dilation. Although NAD(P)H oxidase-derived superoxide has been implicated in the altered vascular responses to hypercholesterolemia, it remains unclear whether this oxidative pathway mediates the associated arteriolar dysfunction and platelet adhesion in venules. Platelet and leukocyte adhesion in cremasteric postcapillary venules and arteriolar dilation resp ...
Extracellular ATP is becoming increasingly recognized as an important regulator of inflammation. However, the known repertoire of P2 receptor subtypes responsible for the proinflammatory effects of ATP is sparse. We looked at whether the P2X1 receptor, an ATP-gated cation channel present on platelets, neutrophils, and macrophages, participates in the acute systemic inflammation provoked by LPS. Compared with wild-type (WT) mice, P2X1(-/-) mice displayed strongly diminished pathological responses ...
To test the hypothesis that endotoxin is absorbed from the gut into the circulation in rats with experimental acute pancreatitis we studied two different animal models. In the first model necrotizing pancreatitis was induced by the ligation of the distal bilio-pancreatic duct while in the second, experimental oedematous acute pancreatitis was induced by subcutaneous injections of caerulein. In both experiments, in the colon of rats with acute pancreatitis endotoxin from Salmonella abortus equi w ...
  • Nobuaki Funata,
  • The Bulletin of Tokyo Medical and Dental University
  • 1979
Cerebral vascular lesions of 26 cases in systemic lupus erythematosus during a period from 1963 to 1978 were examined histologically and the following conclusions were made: 1. The prominent vascular changes of the brain were thrombosis, fibrinoid degeneration, endothelial swelling and proliferation, arteriolosclerosis, and perivascular infiltration of inflammatory cells. 2. From clinico-pathological viewpoints, thrombosis seemed to play an important role in the development of neurological signs ...
Adrenomedullin (ADM) is a multifunctional 52-amino acid peptide involved in numerous physiological and pathological processes, including angiogenesis, growth regulation, differentiation, and vasodilation. ADM is thought to act through the G protein-coupled receptor calcitonin receptor-like receptor, with specificity being conferred by receptor-associated modifying protein 2. The aim of the present study was to clarify the roles of ADM status, and tumor vessels in endometrium. Specimens were exam ...
Hepatic veno-occlusive disease (VOD) is a major regimen-related toxicity after bone marrow transplantation (BMT). Endothelial injury, leading to deposition of coagulation factors within the terminal hepatic venules, is believed to be the key event in the pathogenesis of VOD. To evaluate the benefit and the safety of a VOD prophylaxis with anticoagulants, we conducted a prospective randomized trial of continuous infusion of low-dose heparin among 161 patients under-going either allogeneic (n = 79 ...
During inflammation, the selectin-induced slow rolling of neutrophils on venules cooperates with chemokine signaling to mediate neutrophil recruitment into tissues. Previous studies identified P-selectin glycoprotein ligand-1 (PSGL-1) and CD44 as E-selectin ligands that activate integrins to induce slow rolling. We show here that in TNF-α-treated cremaster muscle venules, slow leukocyte rolling was impaired in mice deficient in moesin, a member of the ezrin-radixin-moesin (ERM) family. Accordin ...
PURPOSE To describe the relationship between retinal vascular calibre and cardiovascular risk factors in a Japanese population. METHODS The Locomotive Syndrome and Health Outcome in Aizu Cohort Study is a population-based, cross-sectional survey that included 2346 persons (56.1% of the eligible population) aged 40 to 74 years old. Retinal vascular calibre was measured from digital retinal photographs using a validated standardized protocol. Data on major cardiovascular risk factors were colle ...
The response of pial vessels to i.p. administration of leu-enkephalin (at 40 μg/kg) is studied biomicroscopically in the control, before and after bilateral occlusion of the common carotid arteries. Leu-enkephalin causes chiefly the narrowing of pial arterioles and does not affect venule diameter. The effect of leu-enkephalin on occlusion of the common carotid arteries manifests itself in the preservation of circulation stability, the narrowing of some arterioles, and in the decrease of the deg ...
Purpose: To determine the association between retinal vascular diameter and its branching angles with diabetic retinopathy (DR) stages in diabetic patients Methods: A descriptive analytic cross-sectional study was conducted in 62 diabetic patients (120 eyes) referred to Farabi Eye Hospital between June 2008 and December 2009. Digital fundus photography pictures were imported into Photoshop software and diameters of arterioles and venules at their second branches from the disc were calculated. Me ...