Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “VESSELS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,117 records · Page 62Linked to original sources
PubMedDate not supplied

[Ultrasonography of changes in the retroperitoneal vessels and perivascular spaces during retroviral infection: preliminary results].

The abdomen in patients with acquired immunodeficiency syndrome (AIDS) is subject to various damage. In AIDS patients, manifestations in the retroperitoneal region, including apparent changes in the pancreas, kidney and lymph nodes, have been well described in the radiological literature. However, abnormalities of the vessels and perivascular spaces have not been well investigated in this syndrome. We performed abdominal sonography in 10 patients who were seropositive for HIV. They had no history of known risk factors such as drug abuse or homosexuality. Also, 4 healthy male controls were examined for comparison. Our aim was to demonstrate and to characterize the pathological changes of the retroperitoneal vessels and perivascular spaces from sonographic observations. The sonographic evaluation included determination of the morphologic and dynamic aspects of the aorta, vena cava and superior mesenteric vessels. The echostructure of the perivascular spaces was analyzed. In this prospective and preliminary study, we have not considered the presence of an AIDS condition. We have precisely analyzed the upper umbilical areas. In all cases, there were supposed to be the same landmarks. The sonographic scans were obtained through the left renal and mesenteric vessel areas, essentially through axial scans. In all 10 patients, sonography showed at least two abnormalities. Three patients had abnormal echostructural changes in all the sites. The images showed echostructural disorganization with poor definition and "fuzzy" and "dirty" aspects of the retroperitoneal vessels and perivascular spaces. The aorta was normal in 2 patients and abnormal in 8 patients with diminished hyperechography and regularity of the aortal wall. The aortic diameter was smaller than 1.5 cm in 7 cases, with a significant attenuation of the beating of the aorta. Despite these abnormalities, the aorta had a normal left paramedian position ahead of the rachis. The inferior vena cava was normal in 1 case and abnormal in 9 cases with diminished hyperechography and regularity of the wall. The vena cava position was normal in 4 cases, displaced in 6, and laminated in 3. The superior mesenteric vessels were abnormal in 8 cases, with poorly defined aims in 6, an indefinite position in 2, and spreading in 2. Adenopathy was present in 6 patients, multiple in 5 and singular in 1 case. A retrocaval location was always observed. A perivascular infiltration and thickening was noted which was diffuse in 6 cases and micronodular in 1 case. From our observations, we conclude that these echostructural changes could be related to AIDS. However, further studies are necessary to confirm these observations and to determine if this sonographic pattern may be seen during the course of the disease. This is the first study to our knowledge which stressed the echostructural changes of the retroperitoneal vessels and perivascular spaces in patients with AIDS.

Abdomen↗
PubMed1996

An examination of the close relationship between lymphatic vessels and nerve fibers containing calcitonin gene-related peptide and substance P in rat skin.

The distribution of nerve fibers containing either calcitonin gene-related peptide (CGRP) and substance P (SP) was investigated in rat skin with special reference to their relationship to the lymphatic vessels. These nerve fibers exhibited a similar distribution pattern but the former were more numerous than the latter. In the dermis and subcutaneous layers, thin nerve fibers containing CGRP or SP were in abundance, and were observed running along the blood vessels as well as freely in the tissue. Nerve fibers with these peptides were often located close to lymphatic capillaries, and innervated lymphatic vessels in the subcutaneous layer, reaching smooth muscles of the tunica media. These findings suggest that some CGRP and SP may directly drain into lymphatic vessels when released under noxious stimulation from nerve fibers around the lymphatic vessels. When discharged from nerve fibers in the vicinity of blood vessels, both peptides may also drain into the lymphatic vessels after causing blood vascular dilation and an increase in permeability producing edema. These peptides may then be transported to the draining lymph nodes where they can modulate the functions of the immune system.

Animals↗
PubMed1997

CD34 expression patterns during early mouse development are related to modes of blood vessel formation and reveal additional sites of hematopoiesis.

CD34 is a cell surface glycoprotein that is selectively expressed within the human hematopoietic system on stem and progenitor cells, and in early blood vessels. To elucidate its functions during early blood vessel formation and hematopoiesis, we analyzed the expression patterns, in day 8 to day 10 mouse embryos, of CD34 RNA by in situ hybridization and protein by immunohistochemistry using the monclonal antibody RAM 34. Levels of expression in embryonic blood vessels were correlated with the mode of vessel formation, being high in pre-endothelial cells and in vessels forming by vasculogenesis (particularly the dorsal aortae) or angiogenesis, but low in vessels forming by coalescence (the cardinal veins). CD34+ erythroid cells, presumably of yolk sac origin, were present in the liver of day 10 embryos; at the same stage, putative definitive hematopoietic cells, strongly CD34+, were present in the para-aortic mesenchyme. Possible sites of hemangioblastic differentiation were detected in the form of CD34+ endothelium-attached hematopoietic cells in the dorsal aorta and in two previously unreported locations, the proximal umbilical and vitelline arteries. These observations suggest functions for CD34 in relation to specific modes of blood vessel formation, and a hemangioblastic role in both embryonic and extraembryonic sites.

Allantois↗
PubMed1976

[Distribution of the chorionic vessels of the human placenta and their arteriovenous crossings (author's transl)].

We examined 100 selected placentas concerning architecture and distribution of the vessels of the chorionic plate. The eccentric insertion of the umbilical cord as well as the mixed type of distribution of the chorial arteries and equal areas of arterial blood supply were found to be most frequent. In no case the anastomosis of Hyrtl was absent. A marginal and a very eccentric cord were more frequent in combination with a mixed and magistral type of distribution of the vessels that the lesser eccentric and the central type of insertion. There was no significant correlation between insertion of the cord and the infants' birth weight. Arteries pass over the veins when they cross. Serial sections of 15 crossing vessels have been examined, one specimen was reconstructed graphically. When crossed by major arteries the veins bypass below whereas small arterial branches override larger veins not affecting their course. The cross-like vessels are wrapped up in connective tissue and anchored to the chorion plate. There are equivalents in the morphology of the vessels of the chorion and the retina. Both vessel systems are embedded in hollow bodies exposed to an inner pressure, however, sharing a common media, the crossing artery and vein of the retina represent a more intense anatomical unity. The connective mesenchymal frame of the crossing vessels of the choroin plate, the thickened arterial wall-segments and the venous wall-sectors let functional valves suspect as is known from other areas of blood supply.

Arteries↗
PubMed1998

Expression of laminin 1 and 2 in brain tumor vessels. An immunohistochemical study.

Components of the blood-brain barrier (BBB) include capillary endothelial cells, the vessel basement membrane (BM) and glial cell interface. While endothelial cell peculiarities are well known and thoroughly studied, BM morphology and functional properties are not. Vessel BM throughout the body is composed of laminin 1, the most common variant of laminin, which is made up of alpha 1, beta 1, and gamma 1 laminin chains, while cerebral vessel BM has been reported to also express the alpha 2 chain. In the present study, we show that the BM of newly formed vessels in brain tumors presents the same immunohistochemical structure as normal brain vessel BM, expressing alpha 1, alpha 2, beta 1, and gamma 1 laminin chains. The function of this particular vessel structure in the central nervous system is not yet completely understood; however, we hypothesize that vessel BM could play a role in impeding the extraneural spreading of brain tumors.

Adult↗
PubMed1996

Significance of vessel count and vascular endothelial growth factor and its receptor (KDR) in intestinal-type gastric cancer.

Angiogenesis is essential for tumor growth and metastasis and depends on the production of angiogenic factors by host and/or tumor cells. The role of angiogenesis and angiogenic factor expression in intestinal- and diffuse-type gastric cancer are undefined. Archival specimens of 51 intestinal-type and 38 diffuse-type human gastric carcinomas were examined for tumor vessel counts, angiogenic factor expression, and the presence or absence of angiogenic factor receptors on tumor endothelium using antibodies against vascular endothelial growth factor (VEGF) and its receptors (KDR and flt-1), basic fibroblast growth factor (bFGF) and its receptors (bek and flg), and factor VIII (endothelial cells). Vessel count and VEGF and bFGF expression were higher in intestinal-type than in diffuse-type gastric cancers (P = 0.01, P < 0.001, and P < 0.001, respectively). Similarly, vessel count and VEGF expression were higher in patients with liver metastasis than in patients with peritoneal dissemination (P = 0.003 and P = 0.01, respectively). Vessel count correlated with VEGF expression and the presence of endothelial KDR in intestinal-type gastric cancer (P = 0.003 and P = 0.02, respectively) but not diffuse-type gastric cancer. Vessel count, VEGF expression, and presence of endothelial KDR increased with increasing stage of disease in intestinal-type gastric cancer but not diffuse-type gastric cancer. The expression of bFGF and its receptors did not correlate with vessel count in either cancer type. These findings suggest that the pattern of metastasis in intestinal-type gastric cancer is angiogenesis dependent. The correlation of VEGF expression and its endothelial receptor with vessel count and stage of disease suggests that VEGF is at least one of the factors responsible for the induction of angiogenesis in intestinal-type gastric cancer.

Adult↗
PubMed1984

Fluorescence microscopic morphometry of functioning blood vessels and adrenergic nerves in myocardium.

The purpose of this study was to quantify the percent volume of actively functioning blood vessels in five dogs subjected to ligation of the left anterior descending artery and to localize catecholamine-containing nerve terminals in the same tissue blocks. Radioactive microspheres were injected to determine the extent of flow reduction in the ischemic zone. After 1 or 3 hr of occlusion, thioflavin-S (0.125 ml/Kg of a 4% solution) was injected intravenously 15 sec prior to removal of the heart. Tissue samples were reacted with paraformaldehyde to visualize catecholamine-containing nerve terminals prior to embedding in paraffin. The percent volume of blood vessels labeled with thioflavin-S was quantitated in tissue sections using a point-counting technique in which a small dot from a video screen was projected through an image-projecting tube and moved by computer control over the image of the fluorescent tissue. In the nonischemic zone, the mean blood flow determined by the microsphere technique was 1.29 ml/min/g +/- 0.48 (SD), and the mean volume percent of thioflavin-labeled vessels was 12.67 +/- 3.30. In the ischemic and border zone areas, there was wide range of flow reduction, and there was a significant correlation between the blood flow measured with microspheres and the percent volume of thioflavin-labeled blood vessels (R = 0.80, P less than 0.001). In the nonischemic zone, both blood vessels and catecholamine-containing nerve terminals were visible; however, in the ischemic zone, few labeled vessels were seen, although nerve terminals were often present.(ABSTRACT TRUNCATED AT 250 WORDS)

Anatomy↗
PubMed1994

Regional differences in prostaglandin production rates among porcine intrathoracic vessels.

To investigate the regional variability in intrathoracic vascular prostaglandin (PG) synthesis, we obtained vessel segments from porcine coronary artery (COA), thoracic aorta (AT), common carotid artery (CRA), pulmonary artery (PA), pulmonary vein (PV), and inferior vena cava (IVC). Vascular production rates of 6-keto-PGF1 alpha (an indicator for PGI2), PGF2 alpha, and PGE2 were measured both in unstimulated state and in arachidonic acid-stimulated state using immunosorbent assays. Our results indicated that PGI2 production rate in all vessel segments decayed with time after vessel dissection. In all vessel segments tested under unstimulated conditions, PGI2 production rates were about one order of magnitude higher than PGF2 alpha and PGE2 production rates of the same specimens. Results from unstimulated, 1.5 hr pre-incubated specimens indicated that i) PGI2 production rates in COA, AT, and PV were greater than those in CRA, PA, and IVC; ii) PGF2 alpha production rates from the same specimens were higher in PV than in AT, CRA, and IVC, while these in PA were higher than in IVC; and iii) PGE2 production rates from the same specimens were not significantly different from one another. Arachidonic acid added at about 1.5 hr after vessel harvest stimulated the PGI2 and PGF2 alpha synthesis rates by 3 to 15 folds. However, this arachidonic acid treatment caused 70 to 300-fold increases in PGE2 production rates, reaching levels comparable to PGI2. All three prostanoid production rates under stimulated conditions were also variable among different intrathoracic vessels. Although either physiological gas concentrations or local hemodynamic conditions alone can partially explain our results, which physiological parameter(s) actually causes these regional differences remains to be verified.

Animals↗
PubMedDate not supplied

Segmental vessel wall shear stress and neointimal formation after sirolimus-eluting stent implantation: physiological insights in a porcine coronary model.

BACKGROUND: Low vessel-wall shear stress promotes atherosclerosis and restenosis. We conducted serial analysis of vessel-wall shear stress following placement of metal and sirolimus (SRL) stents to determine the relationship between shear stress and neointima. METHODS: Serial quantitative coronary angiography, intracoronary ultrasound (IVUS), and Doppler flow analysis were performed at baseline, immediately poststent, and at 30 and 90 days on 16 stents (metal, n = 8; SRL, n = 8) implanted in the coronary arteries of eight miniswine. Segmental vessel-wall shear stress (dyn/cm2) was calculated at 10 sections within the stent and normalized to the average proximal and distal reference vessel shear stress using IVUS and hyperemic average peak flow velocity. At 90 days, histological analysis was completed to determine vessel-wall morphometry on corresponding sections from each stent. RESULTS: Stent placement resulted in a similar degree of in-stent stenosis (-5% to 25%) and immediate post-in-stent shear stress. At 30 days, the IVUS neointimal cross-sectional area and percentage of area stenosis were significantly less in SRL (1.2+/-0.8 mm2; 12.7+/-8.5%) versus metal stents (2.3+/-0.4 mm2; 28.2+/-3.4%, P < .003). In-stent normalized shear stress was less for SRL (0.93+/-0.07) versus metal (1.07+/-0.08, P = .002) stents. At 90 days, the mean neointimal area was similar for the SRL (2.50+/-0.47 mm2) and metal stents (2.72+/-1.15 mm2). Linear regression documented a negative correlation between poststent shear stress and neointima for metal stents (r = .61, P < .0001). In the SRL stents, however, the post-in-stent shear stress had a positive correlation with neointima (r = .40, P = .0002). CONCLUSIONS: The placement of oversized stents causes alteration of segmental vessel-wall shear stress, which appears to be an important physiological stimulus for neointimal formation, and may influence the pharmacodynamics of SRL-eluting stent in the porcine coronary model.

Analysis of Variance↗
PubMed2005

Vessel painting of the microcirculation using fluorescent lipophilic tracers.

Flexible approaches to defining microvessel morphometry are useful in the study of both acute and chronic structural changes of the microcirculation. In this report, we examined the utility of the intravascular infusion of lipophilic carbocyanine tracers in the structural assessment of the retina, skin, lung, and colon microcirculation. The microvessel labeling technique, here termed fluorescent vessel painting, involved the intravascular injection of sulfonated lipophilic carbocyanine tracers. The utility of vessel painting in morphometry was assessed using morphometric comparisons with corrosion casting and 2-dimensional and 3-dimensional scanning electron microscopy. The comparisons demonstrated that fluorescent vessel painting modestly overestimated the interbranch angles, interbranch distances, and vessel diameters of the 2D mucosal plexus of the colon. These differences were narrowed with the application of confocal microscopy. The advantages of fluorescence vessel painting included (1) the filling of all tissues including the relatively high resistance microvessels of the mouse skin, (2) the ability to use tissue counterstains such as DAPI, and (3) the prolonged stability of the lipophilic tracer after aldehyde fixation. These studies suggest the utility of fluorescent vessel painting as a complementary technique to corrosion casting in the morphometric study of the microcirculation.

Animals↗
PubMed1998

Bypass to the perigeniculate collateral vessels. A useful technique for limb salvage: preliminary report on 22 patients.

PURPOSE: We describe our initial experience with the use of perigeniculate vessels as outflow tracts in infrainguinal revascularizations for critical limb ischemia. METHODS: Twenty-two such reconstructions were carried out in 20 patients over a 2-year period. Indications for surgery consisted of tissue loss in 9 patients and rest pain in the other 13 patients. Inflow was obtained from the femoral vessels. A variety of graft materials were used, including saphenous vein (16 patients), polytetrafluoroethylene (2 patients), composite (1 patient), and arterial homografts (3 patients). The perigeniculate vessels used were the medial sural artery to the gastrocnemius (arteria suralis) in 16 patients and the highest genicular artery (arteria genu suprema) in the other 6 patients. These vessels were approached via a medial above-the-knee popliteal-type exposure. RESULTS: There were three postoperative deaths. Mean follow-up for the other 17 patients averaged 12 months (range, 3 to 37 months). Three grafts failed (thrombosis) during follow-up, leading to two above-the-knee amputations. One graft stenosis was treated with percutaneous angioplasty. The average postoperative increase in the ankle-brachial index was 0.20. CONCLUSION: These early results appear promising with a 1-year primary patency rate of 77%, assisted primary patency rate of 85%, and a limb-salvage rate of 90% according to the Kaplan-Meier life-table method. This technique is particularly useful when adequate length saphenous vein is not available, no other outflow vessels are available, or other outflow vessels are very calcified and not safely clamped. The continued study of the long-term effectiveness is warranted.

Aged↗
PubMed2002

Initial observation regarding changes in vessel dimensions after balloon angioplasty and stenting followed by catheter-based beta-radiation. Is stenting necessary in the setting of catheter-based radiotherapy?

AIMS: We sought to compare the effect of intracoronary beta-radiation on the vessel dimensions in de novo lesions using three-dimensional intravascular ultrasound quantification after balloon angioplasty and stenting. METHODS AND RESULTS: Forty patients (44 vessels; 28 balloon angioplasty and 16 stenting) treated with catheter-based beta-radiation and 18 non-irradiated control patients (18 vessels; 10 balloon angioplasty and 8 stenting) were investigated by means of three-dimensional volumetric intravascular ultrasound analysis post-procedure and at 6-8 months follow-up. Total vessel (EEM) volume enlarged after both balloon angioplasty and stenting (+37 mm(3) vs +42 mm(3), P=ns), but vessel wall volume (plaque plus media) also increased similarly (+33 mm(3) vs +49 mm(3), P=ns) in the irradiated patients. Lumen volume remained unchanged in both groups (+3 mm(3) vs -7 mm(3), P=ns). In the stent-covered segments, neointima at follow-up was significantly smaller in the irradiated group than the control group (8 mm(3) vs 27 mm(3), P=0.001, respectively), but the total amount of tissue growth was similar in both groups (33 mm(3) vs 29 mm(3), P=ns). CONCLUSIONS: Intracoronary beta-radiation induces vessel enlargement after balloon angioplasty and/or stenting, accommodating tissue growth. Additional stenting may not play an important role in the prevention of constrictive remodelling in the setting of catheter-based intracoronary beta-radiotherapy.

Aged↗
PubMed1998

A completely biological tissue-engineered human blood vessel.

Mechanically challenged tissue-engineered organs, such as blood vessels, traditionally relied on synthetic or modified biological materials for structural support. In this report, we present a novel approach to tissue-engineered blood vessel (TEBV) production that is based exclusively on the use of cultured human cells, i.e., without any synthetic or exogenous biomaterials. Human vascular smooth muscle cells (SMC) cultured with ascorbic acid produced a cohesive cellular sheet. This sheet was placed around a tubular support to produce the media of the vessel. A similar sheet of human fibroblasts was wrapped around the media to provide the adventitia. After maturation, the tubular support was removed and endothelial cells were seeded in the lumen. This TEBV featured a well-defined, three-layered organization and numerous extracellular matrix proteins, including elastin. In this environment, SMC reexpressed desmin, a differentiation marker known to be lost under standard culture conditions. The endothelium expressed von Willebrand factor, incorporated acetylated LDL, produced PGI2, and strongly inhibited platelet adhesion in vitro. The complete vessel had a burst strength over 2000 mmHg. This is the first completely biological TEBV to display a burst strength comparable to that of human vessels. Short-term grafting experiment in a canine model demonstrated good handling and suturability characteristics. Taken together, these results suggest that this novel technique can produce completely biological vessels fulfilling the fundamental requirements for grafting: high burst strength, positive surgical handling, and a functional endothelium.

Animals↗
PubMed2006

Adventitia contribution in vascular tone: insights from adventitia-derived cells in a tissue-engineered human blood vessel.

Whether the adventitia component of blood vessels directly participates in the regulation of vascular tone remains to be demonstrated. We have recently developed a human tissue-engineered blood vessel comprising the three tunicae of a native blood vessel using the self-assembly approach. To investigate the role of the adventitia in the modulation of vascular tone, this tissue-engineering method was used to produce three vascular constructs from cells explanted and proliferated from donor vessel tunicae 1) an adventitia + a media, or only 2) an adventitia, or 3) a media. The vasoconstriction responses of these 3 constructs to endothelin, the most potent vasopressor known up-to-date, as well as to nonselective and selective agonists and antagonists, were compared. The adventitia contracted to endothelin-1, -2, whereas the media and the media+adventitia contracted to all three endothelins. Endothelin-induced contraction of the adventitia was dependent on ET(A) receptors, whereas that of the media and the adventitia+media was ET(A) and ET(B) receptor-dependent. RT-PCR studies corroborated these results. SNP induced a dose-dependent relaxation of the three tissue constructs. We also demonstrated that the endothelin-converting enzyme, responsible for the formation of the active endothelin peptides, was present and functional in the adventitia. In conclusion, this is the first direct demonstration that the adventitia has the capacity to contract and relax in response to vasoactive factors. The present study suggests that the adventitia of a blood vessel could play a greater role than expected in the modulation of blood vessel tone.

Aspartic Acid Endopeptidases↗
PubMed1995

Pericytes of newly formed vessels in experimental subretinal neovascularization.

OBJECTIVE: To examine the role of pericytes in the progression of subretinal neovascularization in a primate model. METHODS: Subretinal neovascularization was induced by intense laser photocoagulation in four monkey eyes. Single eyes were enucleated at 3, 7, 14, and 21 days after photocoagulation and were studied with light and electron microscopy. RESULTS: Three days after photocoagulation, newly formed vessels were observed in the choroid and subretinal space. Although most of these vessels had an immature appearance and consisted only of endothelial cells that formed narrow lumens, mitotic figures of pericytes were occasionally found near the endothelial cells. Seven days after photocoagulation, all of the newly formed vessels possessed pericytes. Fourteen days after photocoagulation, many vessels appeared to be mature. Many sites of pericyte-endothelial cell contact were observed. These contacts were composed of cytoplasmic interdigitation and membrane apposition. By 21 days after photocoagulation, the mature vessels had increased in number, and the endothelial cells had many fenestrations with diaphragms. The pericyte coverage of the endothelial cells was less at this stage than at 14 days after photocoagulation, and sites of pericyte-endothelial cell contacts were observed only rarely. CONCLUSION: Pericytes are involved in maturation of the endothelial cells that form subretinal new vessels.

Animals↗
PubMed1997

Vessel counts and expression of vascular endothelial growth factor as prognostic factors in node-negative colon cancer.

BACKGROUND: The value of these prognostic factors was compared with that of other clinicopathologic factors such as tumor grade, tumor stage, mucin production, vascular invasion, perineural invasion, and lymphatic invasion. OBJECTIVE: To determine whether the development of distant recurrence in patients with node-negative colon cancer could be predicted using vessel count and vascular endothelial growth factor (VEGF) expression. DESIGN: Paraffin-embedded colon cancers were immunostained for factor VIII, VEGF, basic fibroblast growth factor, and proliferating cell nuclear antigen; slides were reviewed for differentiation, mucin production, and the presence of vascular, lymphatic, and/or perineural invasion. SETTING: A large academic cancer referral center where 27 patients with node-negative colon cancer were operated on during 1988 and 1989. MAIN OUTCOME MEASURE: The development of and interval to recurrence. RESULTS: Eight patients developed liver, lung, or lymph node metastases at a median of 24 months. The median follow-up for patients without cancer recurrence was 60 months. The mean tumor vessel count for those patients who remained disease-free was significantly fewer than for those patients who suffered a recurrence (20 vs 33, respectively). By univariate analysis, 3 factors- perineural invasion, vessel count, and VEGF expression- were correlated with time to recurrence. By multivariate analysis, only vessel count was significantly related to differences in time to recurrence. Expression of VEGF correlated with vessel count. CONCLUSION: Vessel count and expression of VEGF may be useful for predicting distant recurrence in patients with node-negative colon cancer.

Adult↗
PubMed1997

Selective laser photocoagulation of blood vessels in a hamster skin flap model using a specific ICG formulation.

BACKGROUND AND OBJECTIVE: The present study was undertaken to evaluate the selective laser photocoagulation of blood vessels in a hamster skin flap model using a specific indocyanine green (ICG) formulation. STUDY DESIGN/MATERIALS AND METHODS: Experiments were performed in a hamster skin flap model after injection of ICG in aqueous solution (ICGA), or after injection of a specific formulation of ICG (ICG in emulsion: ICGE). Laser irradiation was achieved 30 minutes after injection with a 300 microns fiber connected to a 805 nm diode laser (power = 0.8W, spot diameter = 1.3 mm and pulse exposure time lasting from 1 to 5 s). Macroscopic observation and acute histology were performed to compare the tissue effects obtained for each ICG formulation and to assess the selectivity of vessel damage. RESULTS: The ICGE clearance process was slowed down as compared to the ICGA process. After 30 minutes, the concentration of ICG in blood is higher (2.27 +/- 0.4, P < 0.003) for ICGE compared to ICGA. With ICGA, vessel coagulation required a minimum fluence of 240 J/cm2, which led to very significant skin damage. Conversely with ICGE, vessel coagulation required a fluence of 120 J/cm2. With such a fluence, no laser effect could be detected on the skin. Histological examination confirmed blood vessels coagulation in depth, whereas epidermis and dermis remained intact. CONCLUSION: The major restrictions of ICG in aqueous solution, which are the very-short half-life of ICG in blood and consequently the lack of selectivity in blood vessels after a few minutes, are alleviated when ICG is used in emulsion. ICG in emulsion increases the circulating half-life of ICG and moreover confines ICG in the vascular compartment. Thanks to this specific property, it is possible to obtain a selective vascular damage 30 minutes after injection.

Animals↗
PubMed1998

Innervation of blood vessels in the rat incisor pulp: a scanning electron microscopic and immunoelectron microscopic study.

Although two types of nerve endings have been proposed to innervate blood vessels in the dental pulp, the precise innervation pattern is not well understood. This is mainly due to the lack of information regarding the positional relationships of nerve fibers with blood vessels at the electron microscopic level. The rat incisor pulp was investigated by scanning electron microscopy (SEM) after connective tissue digestion and by transmission electron microscopy after immunohistochemical localization with polyclonal anti-PGP 9.5 antibody. SEM specimens revealed that unmyelinated nerve fibers passed through the tunica adventitia of the blood vessel in the center of the pulp and that these fibers then entered the tunica media of the smaller arterioles. The nerve fibers divided into many collaterals, and these terminated on the surface of smooth muscle cells and endothelial cells. The fibers extended toward smaller vessels. The terminal fibers then reached the subodontoblastic capillary plexus and terminated on pericytes, while the odontoblastic capillary plexus had no direct innervation. In the pulpal venules, nerve fibers were located adjacent to the pericytes and endothelial cells, and they extended toward postcapillary venules. The same results were confirmed by immunoelectron microscopy. The present study demonstrated that in the rat incisor pulp the microvasculature as well as larger vessels were directly innervated by free nerve endings, suggesting that the local regulation of blood flow could take place not only at larger vessels but also at the level of the microvasculature in this tissue.

Animals↗