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At least 217 records · Page 12Linked to original sources
PubMed1989

Deposition of immune complexes containing cationized antibodies in myocardial small blood vessels of mice.

Small myocardial blood vessels constitute a site for preferential deposition of preformed cationic immune complexes. This preferential deposition was demonstrated with a limited dose (100 micrograms) of cationized rabbit antibodies to human serum albumin, injected into C57B1/6J mice either alone or in the form of preformed immune complexes. Heart, kidney, liver, intestine, and skeletal muscle were examined for immune deposits by immunofluorescence microscopy. Highly cationized antibodies injected alone showed deposition in glomeruli and in the liver along the sinusoids but not in other tissues. Immune complexes containing native rabbit antibodies deposited only in liver in a Kupffer cell pattern. Moderate and highly cationized antibodies in immune complexes deposited in myocardial small blood vessels, liver, and glomeruli, but not in intestine or skeletal muscle. These complexes deposited via electrostatic interactions since unrelated polycationic molecules, protamine sulfate or cationized rabbit serum albumin, injected 1 min prior to cationic antibodies in immune complexes blocked deposition in myocardial small vessels, glomeruli, and liver. Administration of protamine or cationized rabbit serum albumin 1 min after deposition of cationized immune complexes resulted in displacement of the immune deposits in heart, kidney, and liver, but not when the injection was given 1 hr later. The presented data indicate that with passage of time the immune deposits rearrange and forces other than charge-charge interactions retain them in myocardial vessels.

Animals↗
PubMed1997

Number and size of epineurial blood vessels in normal and diseased human sural nerves.

The number and dimensions of epineurial blood vessels in normal human sural nerves have, thus far, not been determined using systematic, reproducible morphometric methods, although this nerve is most frequently used for diagnostic biopsies. Quantitative changes in epineurial blood vessels appear to be major parameters for identifying angiopathy and angiopathic peripheral neuropathy. Therefore, we examined the epineurial blood-vessel number in relation to the age of the patients and to the number and size of the nerve fascicles in each of 51 human sural nerve biopsies. The data from a control group were compared with pathological cases. We found that the number of epineurial blood vessels (normal mean: 57. 7) increased significantly (up to 196) in biopsies where there were signs of angiopathy (P</=0.01) or vasculitis (P</=0.05). The increase in the number of epineurial blood vessels usually resulted from a proliferation of capillaries. The fascicular cross-sectional area did not appear to be related to the number of epineurial blood vessels, although it increased significantly in cases with vasculitis (P</=0.05) or an axonal type of neuropathy (P</=0.05). Thus, this study shows that the number of epineurial blood vessels is a helpful parameter in verifying angiopathy and angiopathic peripheral neuropathy.

Adolescent↗
PubMed1999

Digital red-free photography for the evaluation of retinal blood vessel displacement in epiretinal membrane.

OBJECTIVE: To evaluate the displacement of retinal blood vessels during the natural course of epiretinal membrane (ERM) formation. DESIGN: Consecutive observational case series. PARTICIPANTS: Thirteen patients (13 eyes) diagnosed with unilateral idiopathic ERM and 10 normal fellow eyes of the same patients served as a control group and constituted the study group. TESTING: All eyes underwent digital red-free filter photography of the fundus using the Topcon Imagenet-1024 System. Photographs were taken on entry to the study and again after 8 to 13 months. Distances were measured between the major and minor blood vessel junctions at the upper and lower temporal arcades and between the disc margin and vessel junctions temporal to the macula on follow-up examinations. To clearly visualize vessel shift, both photographs of each patient were overlaid using the peripheral landmarks of major blood vessel crossings as reference points. MAIN OUTCOME MEASURES: The parameters measured were shifting of blood vessels caused by the ERM formation. The distances were measured in micrometers using the measurement feature of the Topcon Imagenet System. RESULTS: Blood vessel shift (range, 30 microm-434 microm) was noted in all 13 eyes, but in 15 measurements the shift was less than 30 microm and was considered as no shift. In four eyes (31%), the distances decreased in all directions, indicating contraction of the ERM. In four eyes (31%), the distances increased in all directions, indicating release of the ERMs. A mixed pattern of release and contraction of the ERM in the same eye was noted in five eyes (38%). No shift of blood vessels was noted in the control eyes. Findings on image overlay corresponded with the objective measurements. CONCLUSIONS: Noninvasive digital red-free photography is an informative tool for the objective measurement of the vessel displacement during ERM formation. Contraction and release of the ERM were noted.

Aged↗
PubMed1995

Glioblastoma cells do not intravasate into blood vessels.

Glioblastoma is very rarely found outside the central nervous system. The ability of rat C6 glioblastoma cells to intravasate into central nervous system and pial blood vessels is tested using a rat homografting model and two in vitro models. In vivo, scanning electron microscopy demonstrates that upon grafting C6 cells into implantation pockets in rat cortex, blood vessels can be spared in large digestion cysts formed in host brain parenchyma. Immunocytochemistry of the grafted rat cortex reveals that the glioblastoma cells are upon the blood vessel basement membrane, surrounded by the extracellular matrix material, fibronectin. The endothelial cells of the blood vessel are inside the laminin and fibronectin, and there were areas of endothelial cell hyperplasia. C6 cells are not observed inside blood vessels. In vitro, C6 cell cultures seeded with blood vessels from fresh rat pia exhibit the same relationship of the C6 glioblastoma cells to the blood vessel as those in the other models. The C6 cells migrate upon the pial blood vessel basement membrane but do not intravasate into the blood vessel. To ascertain whether structure and components of the blood vessel basement membrane are important factors in glioblastoma cell exclusion from blood vessels, C6 cells are seeded upon artificial basement membrane hydrated gel wafers. C6 cells migrate into the artificial basement membrane gel wafer by 1 day after seeding. These data indicate that glioblastoma cells are confined to the central nervous system by an inability to pass through vital basement membrane.

Animals↗
PubMed1996

Migrating fetal astrocytes do not intravasate since they are excluded from blood vessels by vital basement membrane.

Astrocytes appear to be excluded from blood vessels. In order to test this observation, pial blood vessels were seeded upon cultures of purified E14 fetal astrocytes. One to seven days later co-cultures were immunohistochemically stained for laminin and fibronectin. Confocal microscopy revealed that laminin-positive cultured astrocytes migrated from the coverslip to and on to the surface of the blood vessels. The fetal astrocytes migrated along the basement membrane but did not enter the blood vessel. Viable (live) basement membrane is a barrier to astrocyte intravasation and is a pathway for astrocyte migration.

Animals↗
PubMed1999

Occurrence and distribution of substance P receptors in the cerebral blood vessels of the rat.

The distribution of immunoreactivity to the receptor for substance P was examined in the cerebral blood vessels of the rat. Substance P immunoreactivity has been demonstrated in the nerve fibers of the cerebral blood vessels. Recently, the production of substance P receptor specific antibody has enabled the detection of localization of the substance P receptor in the central nervous system. In this study, we examined the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia innervating the cerebral blood vessels. Sprague-Dawley rats were perfused with fixative and the pial arteries and the cranial ganglia known to innervate the cerebral blood vessels, i.e., trigeminal, sphenopalatine, internal carotid, otic and superior cervical ganglia, were dissected. All specimens were incubated with anti-substance P receptor IgG, then stained by the avidin-biotin-peroxidase complex method. Numerous nerve fibers with varicosities forming plexuses, with substance P receptor immunoreactivity were observed on the walls of the major extracerebral arteries forming the circle of Willis and its branches. Substance P receptor immunoreactivity was also detected in the endothelium of the cerebral arteries. Substance P receptor immunoreactivity was positive in many neurons of the sphenopalatine ganglion, otic ganglion, trigeminal ganglion, superior cervical ganglion and internal carotid ganglion. The present study demonstrated the existence of nerve fibers with substance P receptor immunoreactivity in the cerebral blood vessels and the cranial ganglia that innervate the cerebral blood vessels. These findings are important in understanding the responsiveness of the cerebral blood vessels to substance P.

Absorption↗
PubMed2005

Detection of needle puncture to blood vessel using puncture force measurement.

Although blood sampling is frequently performed, a system to take blood samples automatically has not yet been developed. In the paper, as a first step towards automatic blood sampling, an examination of an automatic method for puncturing blood vessels is described. The force waveforms produced by puncturing rabbit ear veins were measured. A characteristic peak, possibly associated with the needle piercing the vessel wall, was observed in each waveform of ten successful cases of 14 trials. An algorithm that allowed the detection of this peak was developed, and parameters of a filter to improve the accuracy of the algorithm were determined. Using this algorithm, automatic needle punctures were performed in a rabbit ear vein and then were simulated using the data derived from manual needle puncture on four other rabbits. The results gave 30 fully successful cases of 33 trials of needle puncture and showed that measurement of the puncture force may be important for automatic needle puncture of blood vessels.

Animals↗
PubMed1995

Localization and characterization of endothelin-1 receptor binding in the blood vessels of human pulmonary tumors.

We have demonstrated endothelin-1 (ET-1) binding sites in the blood vessels of human pulmonary tumors by in vitro autoradiography. The blood vessels of the tumors were confirmed by immunostaining with von Willebrand factor. Specific [125I]ET-1 binding was identified in the blood vessels of all sizes in both tumor and stromal tissues. Nonspecific binding was observed in squamous cell carcinomas and in carcinoids. The ET-1 binding in blood vessels was specific, saturable, and time-dependent. The binding reached equilibrium at 120 min. Scatchard analysis of [125I]ET-1 binding to sections of blood vessels of squamous cell carcinoma indicated binding to a single class of binding sites, with a dissociation constant (Kd) of 0.16 nM and a maximal density of binding sites (Bmax) of 126 amol/mm2. The binding was competitively inhibited by ET-1 >> VIC > ET-2 > sarafotoxin (SRb) > ET-3 but not by other unrelated peptides. Our results provide evidence that ET-1 binding is localized in the blood vessels of pulmonary tumors and in stromal tissues surrounding the tumor nest. ET may play a role in the angiogenesis of tumor growth.

Autoradiography↗
PubMed1970

The effect of ethyl alcohol and chlorpromazine on the response of the hand blood vessels to cold.

1. The response of hand blood flow to a measured cold stimulus was determined using venous occlusion plethysmography in normal subjects, before and after orally administered alcohol, and in patients on chlorpromazine therapy.2. The average resting hand blood flow of the patients taking chlorpromazine, as well as the constriction of these blood vessels to cold, was the same as in the normal subjects.3. Oral alcohol caused a rise in resting hand blood flow in the normal subjects and also modified the response of the hand blood vessels to cooling.4. A patient with a completely denervated hand was also studied. Oral alcohol did not increase the blood flow through the part, but it modified the hand vascular response to cold.5. These results suggest a diminished reactivity of the hand blood vessels to cold in the presence of alcohol.

Adult↗
PubMed2001

Corrections for inhomogeneities in biological tissue caused by blood vessels.

In tissue optics, the assumption that blood is homogeneously distributed in tissue can give rise to miscalculations because blood is found only in blood vessels. In our paper randomly oriented blood vessels are treated as particles for which we obtained apparent absorption and scattering coefficients by means of the Monte Carlo method. Apart from this correction for the contribution of blood properties in tissue, a correction for the contribution of the surrounding tissue proved to be needed as well. The results found with our model were compared with available results from the literature.

Blood Vessels↗
PubMed2005

[Construction of the scaffold model from heterogeneous small blood vessels].

OBJECTIVE: To establish a scaffold model from heterogeneous small blood vessels. METHODS: Caudal arteries from 34 Wistar rats (average length 12.08 +/- 1.69 cm) were made into acellular blood vessel scaffolds. Some scaffolds were observed by electron microscope, and others were transplanted to the cut ends of ear central arteries of male Japanese big ear white rabbits. RESULTS: Average external diameter was 0.74 +/- 0.08 mm in proximal, and 0.55 +/- 0.08 mm in distal end of rat caudal arteries. The small blood vessel scaffolds had shin wall which was white and soft, composed of fibrous tissues without cells. On the intima surface the fibrous tissues were arrayed densely in a grid-like pattern. After transplantation, the blood flow was reserved, and kept flowing freely in 24 hours. The pulsation of the transplanted artery was accessible and no blood leakage was found. CONCLUSION: The natural scaffolds are composed of fibrous tissues, and can sustain the artery pulse pressure for 24 hours. It is better to suture the blood vessels by sleeve anastomosis.

Animals↗
PubMed2006

Classic beta-amyloid deposits cluster around large diameter blood vessels rather than capillaries in sporadic Alzheimer's disease.

Various hypotheses could explain the relationship between beta-amyloid (Abeta) deposition and the vasculature in Alzheimer's disease (AD). Amyloid deposition may reduce capillary density, affect endothelial cells of blood vessels, result in diffusion from blood vessels, or interfere with the perivascular clearance mechanism. Hence, the spatial pattern of the classic ('cored') type of Abeta deposit was studied in the upper laminae (I,II/III) of the superior frontal gyrus in nine cases of sporadic AD (SAD). Sections were immunostained with antibodies against Abeta and with collagen IV to study the relationships between the spatial distribution of the classic deposits and the blood vessel profiles. Both the classic deposits and blood vessel profiles were distributed in clusters. In all cases, there was a positive spatial correlation between the clusters of the classic deposits and the larger diameter (>10 microm) blood vessel profiles and especially the vertically penetrating arterioles. In only 1 case, was there a significant spatial correlation between the clusters of the classic deposits and the smaller diameter (<10 microm) capillaries. There were no negative correlations between the density of Abeta deposits and the smaller diameter capillaries. In 9/11 cases, the clusters of the classic deposits were significantly larger than those of the clusters of the larger blood vessel profiles. In addition, the density of the classic deposits declined as a negative exponential function with distance from a vertically penetrating arteriole. These results suggest that the classic Abeta deposits cluster around the larger blood vessels in the upper laminae of the frontal cortex. This aggregation could result from diffusion of proteins from blood vessels or from overloading the system of perivascular clearance from the brain.

Aged↗
PubMed1999

Vitamin C deficiency in guinea pigs differentially affects the expression of type IV collagen, laminin, and elastin in blood vessels.

Vitamin C deficiency causes morphologic changes in the endothelial and smooth muscle compartments of guinea pig blood vessels. Endothelial cells synthesize the basement membrane components, type IV collagen and laminin, and smooth muscle cells synthesize elastin in blood vessels. Therefore, we examined the possibility that vitamin C deficiency affects the expression of these proteins. Decreased expression of types I and II collagens in other tissues of vitamin C-deficient guinea pigs is associated with weight loss and the consequent induction of insulin-like growth factor binding proteins; thus we also used food deprivation to induce weight loss. Female guinea pigs received a vitamin C-free diet, supplemented orally with ascorbate. Vitamin C-deficient guinea pigs received the same diet but no ascorbate, and the food-deprived group received no food, but were supplemented with vitamin C. Concentrations of mRNAs for basement membrane components and elastin in blood vessels were measured by Northern blotting; overall basement membrane metabolism was assessed by measuring immunoreactive laminin and type IV 7S collagen in serum. Laminin mRNA in blood vessels and serum laminin concentrations were unaffected by vitamin C deficiency. Concentrations of type IV collagen and elastin mRNAs in blood vessels were not significantly affected in moderately scorbutic guinea pigs (0-7% weight loss), but with increased weight loss, type IV collagen mRNA was 57% (P < 0.05) and elastin mRNA was 3% (P < 0. 01) of normal values. In food-deprived guinea pigs, type IV collagen mRNA was 51% (P < 0.05) and elastin mRNA was 35% (P < 0.05) of normal. Serum type IV 7S collagen concentrations were 25% of normal in scorbutic guinea pigs with extensive weight loss. The lower expression of type IV collagen and elastin mRNAs in blood vessels may contribute to defects observed in blood vessels during scurvy.

Amino Acid Sequence↗
PubMed1980

Heat transfer to blood vessels.

Heat transfer to individual blood vessels has been investigated in three configurations: a single vessel, two vessels in counterflow, and a single vessel near the skin surface. For a single vessel the Graetz number is the controlling parameter. The arterioles, capillaries, and venules have very low Graetz numbers, Gz < 0.4, and act as perfect heat exchangers in which the blood quickly reaches the tissue temperature. The large arteries and veins with Graetz numbers over 10(3) have virtually no heat exchange with the tissue, and blood leaves them at near the entering temperature. Heat transfer between parallel vessels in counterflow is influenced most strongly by the relative distance of separation anad by the mass transferred from the artery to the vein along the length. These two effects are of the same order of magnitude, whereas the film coefficients in the blood flow are of significant but lesser importance. The effect of a blood vessel on the temperature distribution of the skin directly above it and on the heat transfer to the environment increases with decreasing depth-to-radius ratio and decreasing Biot number based on radius. The absolute magnitude of these effects is independent of other linear effects, such as internal heat generation or a superimposed one-dimensional heat flux.

Arteries↗
PubMed1992

[The effect of halothane, alfentanil and propofol on blood flow velocity, blood vessel cross section and blood volume flow in the middle cerebral artery].

Transcranial Doppler sonography (TCD) has gained in relevance for noninvasive monitoring of the cerebral circulation during the perioperative period. As long as the diameters of the investigated vessels remain unknown, however, flow velocities alone are not really informative. Exact vessel diameter determination in humans under the influence of different anesthetic drugs has not yet been performed due to ethical and methodological restrictions. A new modification of TCD allows analysis of the reflected "Doppler power", which is proportional to the cross-sectional area of the insonated vessel. METHODS. Three groups of 15-16 patients each (ASA I) were investigated after informed consent. Anesthesia was induced with droperidol, alfentanil, thiopental, and vecuronium bromide. After intubation patients were normoventilated with N2O:O2 = 3:2 and additional doses of alfentanil were injected until the transcranial ultrasound probe was fixed to the temporal bone and focused on the middle cerebral artery. Baseline values of heart rate (HR), mean arterial pressure (MAP), expiratory minute volume (EMV), end-expiratory CO2 (FeCO2), and TCD were measured. Then 1.5 vol% halothane, 25-50 micrograms/kg alfentanil, or propofol (1.5 mg/kg iv., 10 mg/kg.min) was administered. Further measurements (HR, MAP, EMV, FeCO2 and TCD) were performed at 3, 6, 10, and 20 min after the start in the halothane and propofol groups and after 3 and 6 min in the alfentanil group. The following transcranial parameters were derived from the TCD device: mean maximal flow velocity (vmmax), pulsatility index, time-averaged mean velocity (vmmen), "vessel area (VA)", and "volume flow (VF)". The mean +/- standard deviation of each parameter was calculated. Statistical evaluation was performed by paired t-tests (level of significance P less than 0.05). RESULTS. HR showed a tendency to increase after halothane and to decline after alfentanil. Alfentanil induced a short-term decline in MAP. End-expiratory minute volume and FeCO2 showed only minor alterations in all three groups. The vmmax was nearly doubled by halothane. Alfentanil induced a transitory decline in vmmax while Propofol decreased it markedly. The pulsatility index showed a decrease after halothane; alfentanil caused a short-term increase. Propofol induced a strong increase after 3 min; in the following period a return to baseline values was observed. The vmmean was increased by halothane and reduced by 32% propofol. VA was found to be unaltered by alfentanil and propofol but was more than doubled by halothane. Accordingly, the relative value for VF increased by 148% under halothane. VF appeared to decline after propofol. DISCUSSION. The described method allows only the determination of relative values: it is not possible to quantify exactly how much the VA changed. Halothane caused significant increases of VA measured in the middle cerebral artery, whereas alfentanil and propofol did not influence this parameter. This is in accordance with previous experiments in dogs in which halothane decreased the resistance of large basal cerebral arteries (LAR). LAR remained unaltered after alfentanil administration. The site of action of some anesthetic agents on cerebral vessels does not seem to be restricted to cerebral arterioles: at least for halothane, a vasodilating effect on large cerebral arteries could be demonstrated. This should be kept in mind when transcranial Doppler is applied during the perioperative period.

Alfentanil↗
PubMed1994

The blood vessels in Reissner's membrane of the rat.

Blood vessels on Reissner's membrane were electron-microscopically found in 24 out of 30 rats of the Wistar strain. The vessels were noted in the upper turns, mainly in the third turn of the cochlea. They originated from radiating arterioles in the upper spiral ligament and took straight courses radially down to the spiral limbus, and further to the modiolus, running along the surface of the scala vestibuli side of the membrane. Their diameter was approximately 4 microns. Bifurcated blood vessels were occasionally detected in 3 out of the 24 rats that possessed the vessels in the membrane. From the morphological point of view the blood vessels in Reissner's membrane may possibly have some function in the inner ear of the rat.

Animals↗
PubMed2003

New vessel formation after surgical brain injury in the rat's cerebral cortex I. Formation of the blood vessels proximally to the surgical injury.

Postnatal neovascularization has been previously considered synonymous with angiogenesis but it was found that circulating endothelial progenitor cells may home into sites of neovascularization and their differentiation into endothelial cells is consistent with vasculogenesis. In this study, we investigated neovascularization of the adult rat's cerebral cortex after surgical brain injury by electron microscopic ultrastructural and immunocytochemical studies. We found places with disrupted brain parenchyma. The blood vessels showed an incomplete endothelial lining. In the brain parenchyma we observed fibrin, likely derived from disrupted blood vessels. In the plasma there were cell aggregates characterized by endothelial-like features with fibrils in the cytoplasm, untypical for endothelial cells. These endothelial-like cells participated in the process of new vessel formation. We used the anti-alpha(v) beta3 integrin antibody to visualize the different morphogenic stages of newly formed blood vessels. We demonstrated the relationship between alpha(v) beta3 integrin localization and different stages of new vessel formation. Our data suggest that growth and development of new blood vessels due to neovascularization following trauma of the adult rat brain are not restricted to angiogenesis but encompass vasculogenesis as well.

Animals↗