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PubMed2006

Intrauterine growth restriction and the proliferation of smooth muscle cells in umbilical vessels.

AIMS: The purpose of this study was to investigate the proliferation of smooth muscle cells in umbilical vessels of fetuses affected by intrauterine growth restriction (IUGR) and to compare the findings with gestational age-matched control cases. METHODS: Sixty umbilical cords from fetuses at 36-37 weeks gestation were examined. Fetuses were divided into three groups: group I, appropriate for dates birthweight; group II, IUGR with reassuring fetal status; and group III, IUGR with abnormal umbilical Doppler waveforms. Umbilical cords were immunostained with an antibody to proliferating cell nuclear antigen and Ki-67; stained smooth muscle cells were subsequently counted. Smooth muscle cell density was determined by counting the total number of cells in a representative area of vessel wall and the wall thickness of each vessel was also measured. RESULTS: Proliferation marker-positive cells were increased in the umbilical vessels of group II compared to group I, and there were more proliferating smooth muscle cells in the umbilical vessels of group III compared to the other two groups. The umbilical vessels of group III showed the highest smooth muscle cell density, but the wall thickness of all vessels was significantly thinner in group III than the other two groups. CONCLUSIONS: This study showed overproliferation of smooth muscle cells in the umbilical vessel walls associated with IUGR. It is hypothesised that hypoxia might induce this overproliferation given the further proliferation in IUGR fetuses with abnormal umbilical Doppler waveforms. Coexistence of a high cell density and lean vessel walls suggests small smooth muscle cells in umbilical vessels with IUGR.

Adult↗

PubMed1999

Quantitative evaluation of vessel tracking techniques on coronary angiograms.

Accurate, automated determination of vessel center lines is essential for two- and three-dimensional analysis of the coronary vascular tree. Therefore, we have been developing techniques for vessel tracking and for evaluating their accuracy and precision in clinical images. After points in vessels are manually indicated, the vessels are tracked automatically by means of a modified sector-search approach. The perimeters of sectors centered on previous tracking points are searched for the pixels with the maximum contrast. The sector size and radius are automatically adjusted based on local vessel tortuosity. The performance of the tracking technique in regions of high-intensity background is improved by application of a nonlinear adaptive filtering technique in which the vessel signal is effectively removed prior to background estimation. The tracking results were evaluated visually and by calculation of distances between the tracked and user-indicated centerlines, which were used as the "truth." Two hundred and fifty-six coronary vessels were tracked in 32 angiograms. Vessels as small as 0.6 mm in diameter were tracked accurately. This technique correctly tracked 255/256 (>99%) vessels based on an average of 2-3 indicated points per vessel. The one incorrect tracking result was due to a low signal-to-noise ratio (SNR<2). The distance between the tracked and the "true" centerlines ranged from 0.4 to 1.8 pixels, with an average of 0.8 pixels. These results indicate that this technique can provide a reliable basis for 2D and 3D vascular analysis.

Coronary Angiography↗

PubMedDate not supplied

Evaluation of crossing vessels in patients with ureteropelvic junction obstruction by means of helical CT.

Helical computed tomography (CT) was used to demonstrate the distribution of crossing vessels in patients with ureteropelvic junction (UPJ) obstruction for planning surgical management. Twenty patients with symptomatic UPJ obstruction were evaluated with dual-phase contrast material-enhanced helical CT. In addition to axial images, coronal, sagittal, and curved paracoronal images along the crossing vessels or the UPJ were obtained by means of multiplanar reconstruction. Crossing vessels were evaluated according to type, position, and association with UPJ obstruction. Fifteen vessels in 12 of the 20 patients were found to cross the UPJ at helical CT. Nine vessels were arteries and six were veins; seven vessels crossed anteriorly and eight crossed posteriorly. In 11 patients, crossing vessels were thought to be associated with UPJ obstruction at helical CT; retroperitoneoscopic repair was performed, and the diagnosis was found to have been accurate in all except one. In the eight patients in whom no significant vessels were seen and the one patient in whom the crossing vessel was not associated with UPJ obstruction at helical CT, endopyelotomy was performed and UPJ obstruction was relieved, with no complications. Helical CT is useful for evaluation of vessels crossing the UPJ and for planning surgical management.

Adolescent↗

PubMed1997

Collagen content is significantly lower in restenotic versus nonrestenotic vessels after balloon angioplasty in the atherosclerotic rabbit model.

BACKGROUND: It is recognized that restenosis is primarily due to alterations in geometric remodeling of the extracellular matrix rather than intimal hyperplasia. Prior studies have shown that angioplasty stimulates an increase in both synthesis and degradation of collagen in the atherosclerotic vessel. However, differences in collagen content and metabolism between restenotic and nonrestenotic vessels have not been examined. METHODS AND RESULTS: Four weeks after angioplasty in an atherosclerotic rabbit model, collagen content in restenotic and nonrestenotic vessels was measured both biochemically by hydroxyproline quantitation and histologically by a digital subtraction method with the use of circularly polarized images of picrosirius red-stained sections. Collagenase and gelatinase activity also were measured in the same restenotic and nonrestenotic vessels by use of a radiosubstrate assay. Collagen content was found to be significantly lower in restenotic vessels than in nonrestenotic vessels both biochemically (127.0 +/- 32.6 versus 212.6 +/- 84.3 micrograms/mg tissue; n = 11 vessels; P < .05) and histologically (67.3 +/- 7.9% versus 76.3 +/- 11.8% area fraction; n = 20 sections from 6 vessels; P = .05). There was a significant inverse correlation between biochemically determined collagen content and gelatinase activity (P = .02) and a significant correlation between histologically determined lumen are and percent collagen content (P = .0071). CONCLUSIONS: Collagen content is significantly decreased in restenotic versus nonrestenotic vessels after angioplasty in the atherosclerotic rabbit model. The increased collagen content in nonrestenotic vessels was associated with preserved lumen area and may play a role in geometric remodeling after angioplasty.

Angioplasty, Balloon↗

PubMedDate not supplied

Prolonged exposure to ouabain eliminates the greater norepinephrine-dependent calcium sensitivity of resistance vessels in spontaneously hypertensive rats.

The effects of 30 minutes of exposure to ouabain on calcium sensitivity have been investigated in two types of resistance vessels from 12 pairs of spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. Branches of the superior mesenteric and femoral arteries, with internal diameters of about 200 micrometer, were mounted as ring preparations in a myograph capable of measuring their isometric wall tension. Dose-response curves for calcium upon norepinephrine stimulation were determined under conditions where neuronal uptake was eliminated. Initially, when stimulated with norepinephrine, the SHR vessels from both locations were more sensitive to calcium and had stronger contractions than their controls. The addition of ouabain (1 mM) to the relaxed vessels immediately elicited a moderate, transient contraction in the branches of the femoral artery, whereas no response was observed in the mesenteric vessels. Although the addition of ouabain to activated vessels produced an immediate potentiation of the response, prolonged (30-minute) exposure to ouabain reduced active tension development upon norepinephrine stimulation in all vessels. The reduction was greatest in the SHR vessels, so that, under these conditions, the norepinephrine-activated calcium sensitivity of corresponding SHR and WKY vessels was similar. By contrast, responses to norepinephrine in high potassium solution were unaffected. The results suggest that under normal conditions, SHR vessels may have a specific increase in the permeability of the norepinephrine-activated calcium channels. Prolonged exposure to ouabain appears to reduce the permeability of these channels, providing an explanation for why this treatment eliminates the difference in calcium sensitivity of the SHR and WKY vessels.

Animals↗

PubMed2002

Analysis of mural cell recruitment to tumor vessels.

BACKGROUND: Tumor blood vessels are both structurally and functionally abnormal compared with normal vessels. A limited support of mural cells may contribute to these abnormalities. Here, we characterized mural cell recruitment in 2 mouse tumor models and addressed the question of why tumor vessels fail to recruit a proper coat of mural cells. METHODS AND RESULTS: We studied mural cell recruitment to the vasculature of 2 transplantable mouse tumor models, T241 fibrosarcoma and KRIB osteosarcoma. We found that both tumors formed a vessel network with heterogeneous and highly abnormal organization of mural cells. Transplantation of tumors to mice expressing lacZ in mural cells demonstrated that these cells were host-derived. Although tumor vessel endothelium expressed PDGF-B, an embryonic mitogen for mural cells, only very few PDGFRbeta-positive cells were found to be associated with the developing tumor vasculature, suggesting a limited pool of recruitable mural cells. We tested whether exogenous mural cells could be recruited to tumor vessels by injecting mixtures of T241 tumor cells and embryonic mesenchymal cells isolated from mice expressing lacZ in mural cells. In the tumors that arose, lacZ-positive cells were efficiently recruited to the tumor vessels. CONCLUSIONS: T241 and KRIB tumors show a similar highly abnormal organization of vessel-associated mural cells. T241 tumor vessels seem highly capable of recruiting exogenously added mural cells. The sparse mural cell coat of tumor vessels may result from a limited pool of mural cells available for recruitment.

Actins↗

PubMed1999

Hyperoxia and glucocorticoid modify retinal vessel growth and interleukin-1 receptor antagonist in newborn rabbits.

Retinopathy of prematurity (ROP) is characterized by inhibition of the growth of the retinal vessels and subsequent neovascularization. Pharmacologic doses of glucocorticoids are known to decrease growth and to suppress inflammation. The aim of the present study was to investigate whether hyperoxia and/or glucocorticoid affect the growth of the retinal vessels and the expression of the anti-inflammatory cytokine IL-1 receptor antagonist (IL-1ra). The following treatments were given to newborn rabbits during the rapid growth of retinal vessels: 1) placebo and room air (n = 14); 2) dexamethasone (Dx) at 1 mg/kg/d during d 3 to 8 and room air (n = 14); 3) placebo and 100% oxygen (d 3 to 7) (n = 14); 4) Dx and O2 (n = 16). On d 12, the eyes were studied for retinal vessel length and vascular surface area from India ink-perfused vessels. When indicated, retinas were harvested on d 7 and studied for the expression of IL-1ra mRNA using Northern blot analysis. Hyperoxia decreased the length and area of the retinal vessel complexes (p < 0.01) and induced neovascularization in three of eight animals (38%). Dx decreased the length and area (p < 0.01) and tended to increase the tortuosity of the retinal vessels. Dx did not potentiate the hyperoxia-induced suppression of retinal vessel growth and prevented the hyperoxia-induced neovascularization (p = 0.04). Hyperoxia inhibited the expression of IL-1ra mRNA, whereas Dx ameliorated the hyperoxia-induced suppression of IL-1ra. According to present results, glucocorticoid decreases the retinal vessel growth and may decrease the hyperoxia-induced neovascularization. We propose that immature and damaged retinal vessels are affected by pharmacologic dosage of glucocorticoid.

Animals↗

PubMed1993

Role of femoral vessel catheterization and altered hemostasis in the development of extraperitoneal hematomas: CT study in 44 patients.

OBJECTIVE: To ascertain the role of femoral vessel catheterization and altered hemostasis in the development of extraperitoneal hematomas, we evaluated CT scans to study the locations of extraperitoneal hematomas in three distinct clinical settings: (1) after femoral vessel catheterization with concurrent altered hemostasis due to anticoagulant, thrombolytic, and/or antiplatelet therapy (catheterized-altered hemostasis group); (2) after femoral vessel catheterization without altered hemostasis (catheterized group); and (3) with no history of femoral vessel catheterization, with or without altered hemostasis caused by a bleeding diathesis or pharmacotherapy (uncatheterized group). MATERIALS AND METHODS: Forty-four patients were identified who had CT evidence of extraperitoneal hematomas. Twenty-four were in the catheterized-altered hemostasis group, one was in the catheterized group, and 19 were in the uncatheterized group. CT scans were evaluated for anatomic subspace involvement by hemorrhage and for the presence or absence of contiguity between the hematoma and the femoral vessels. RESULTS: Bilateral hematomas were present in six of 24 patients in the catheterized-altered hemostasis group and in four of 19 patients in the uncatheterized group. We found no significant difference between the catheterized-altered hemostasis and the uncatheterized groups regarding the proportion of cases involved at any individual retroperitoneal site (p > .05). The mean number of hematoma sites in the catheterized-altered hemostasis group (4.3) was not significantly different from the mean number in the uncatheterized group (3.7) (p > .05). Contiguity between the sites of hematoma and the punctured femoral vessels was present in 75% of the patients in the catheterized-altered hemostasis group; contiguity between the hematoma and a groin was seen in 58% in the uncatheterized group. Twenty-two of 24 patients in the catheterized-altered hemostasis group had CT findings of subcutaneous fat infiltration in the groin; however, six of 19 patients in the uncatheterized group also had this finding, indicating that its presence does not always represent changes caused by catheterization. CONCLUSION: Retroperitoneal hematomas in patients with altered hemostasis and femoral vessel catheterization do not show a unique distribution attributable solely to contiguous spread of blood from the vessel puncture site. Many of these hematomas probably arise at sites distant from the femoral vessel puncture. When the hematoma is not contiguous with the punctured femoral vessels, altered hemostasis is most likely the cause of the hemorrhage.

Catheterization, Peripheral↗

PubMed1993

CT diagnosis of superior vena cava syndrome: importance of collateral vessels.

OBJECTIVE: The purpose of this study was to evaluate the importance of collateral vessels in the CT diagnosis of superior vena cava syndrome. MATERIALS AND METHODS: Forty-seven patients with CT evidence of obstruction or compression of the superior vena cava or its major tributaries were included in this study. Contrast-enhanced CT scans had been obtained with a combined bolus and drip-infusion technique. We evaluated the CT scans, with particular attention to the presence of collateral vessels (and if present, their location), without knowing the patients' clinical histories. On reviewing the patients' charts, we found 23 patients with signs or symptoms of superior vena cava syndrome. We then correlated the presence of collateral vessels with the presence of signs and symptoms of superior vena cava syndrome. To verify the frequency of visible collateral vessels in healthy subjects, we also evaluated CT scans of 50 control subjects who did not have mediastinal disease or signs and symptoms of superior vena cava syndrome. RESULTS: Collateral vessels were seen on CT scans in 24 patients. Among the 23 patients who had signs and symptoms of superior vena cava syndrome, 22 patients had CT scans that showed collateral vessels. Two cases were false-positive and one was false-negative. The presence of collateral vessels, regardless of the number and location of the vessels shown on CT scans, was highly accurate as a predictor of superior vena cava syndrome, with a sensitivity of 96% and a specificity of 92%. Collateral vessels were seen in three (6%) of the 50 control subjects. CONCLUSION: We conclude that the presence of collateral vessels is a highly sensitive and specific CT sign of superior vena cava syndrome.

Adolescent↗

PubMed1999

MR angiography versus color Doppler sonography in the evaluation of renal vessels and the inferior vena cava in abdominal masses of pediatric patients.

OBJECTIVE: Involvement of renal vessels and the inferior vena cava (IVC) plays a decisive role during operative planning for removal of abdominal masses in pediatric patients. Advantages and limitations of MR angiography and color Doppler sonography for determining these factors were evaluated. MATERIALS AND METHODS: MR angiography and color Doppler sonography were performed preoperatively in 42 neonates, infants, and children with abdominal masses and were compared with spin-echo MR imaging and with surgical findings. Variables evaluated were anatomic variants, vessel displacement, patency of vessels, collateral circulation, and intravascular tumor extension. Quality of vessel visualization was assessed in vessels not affected by tumor. RESULTS: In 88% of unaffected renal vessels, the entire vessel course could be visualized on MR angiography compared with 58% on color Doppler sonography and 43% on spin-echo MR imaging. In four of nine cases, color Doppler sonography revealed an accessory renal artery, whereas MR angiography revealed these variants in seven of nine cases. MR angiography showed 79% and color Doppler sonography 66% of displaced vessels. Unlike MR angiography, color Doppler sonography did not reveal five stenotic renal veins because they could not be completely imaged. In two cases, however, MR angiography falsely indicated an occlusion of the IVC, whereas color Doppler sonography showed residual flow. CONCLUSION: Anatomic variants, vessel displacement, collateral circulation, and neoplastic vessel infiltration were revealed more accurately by MR angiography than by color Doppler sonography. In cases in which patency of the IVC is unclear on MR angiography, color Doppler sonography should also be performed.

Abdominal Neoplasms↗

PubMed1981

Evidence that the increased calcium sensitivity of resistance vessels in spontaneously hypertensive rats is an intrinsic defect of their vascular smooth muscle.

We have investigated media thickness and noradrenaline- and calcium-sensitivity of isolated mesenteric resistance vessels from spontaneously hypertensive (SHR) and control Wistar-Kyoto (WKY) rats, which had been treated in various ways. Vessels from untreated SHRs had an increased media thickness and increased noradrenaline- and calcium-sensitivity. Anti-hypertensive treatment of SHRs and WKYs with Felodipine reduced blood pressure, eliminated the difference in vessel media thickness, but did not reduce vessel noradrenaline- or calcium-sensitivity. Chemical sympathectomy of SHRs and WKYs at birth likewise resulted in reduced blood pressure, but did not eliminate the difference in vessel media thickness although again vessel noradrenaline- and calcium-sensitivity remained unchanged. Induction of renal hypertension in WKYs caused an increase in blood pressure and increase in vessel media thickness, but did not affect vessel noradrenaline-sensitivity. The results suggest that while vessel media thickness is influenced by blood pressure, the sensitivity differences of SHR resistance vessels are an intrinsic defect of their vascular smooth muscle, independent both of blood pressure and neurogenic influences.

Animals↗

PubMed2004

Expansion of endothelial surface by an increase of vessel diameter during tumor angiogenesis in experimental and hepatocellular and pancreatic cancer.

AIM: A low vessel density is a common feature of malignant tumors. We suggested that the expansion of vessel diameter might reconstitute the oxygen and nutritient's supply in this situation. The aim of the present study was to compare the number and diameter of blood vessels in pancreatic and liver carcinoma with normal tissue. METHODS: Tumor induction of pancreatic (DSL6A) or hepatocellular (Morris-hepatoma) carcinoma was performed in male Lewis (pancreatic cancer) and ACI (hepatoma) rats by an orthotopic inoculation of solid tumor fragments (pancreatic cancer) or tumor cells (hepatoma). Six weeks (pancreatic cancer) or 12 d (hepatoma) after tumor implantation, the tumor microvasculature as well as normal pancreatic or liver blood vessels were investigated by intravital microscopy. The number of perfused blood vessels in tumor and healthy tissue was assessed by computer-assisted image analysis. RESULTS: The vessel density in healthy pancreas (565+/-89 n/mm(2)) was significantly higher compared to pancreatic cancer (116+/-36 n/mm(2)) (P<0.001). Healthy liver showed also a significantly higher vessel density (689+/-36 n/mm(2)) compared to liver carcinoma (286+/-32 n/mm(2)) (P<0.01). The comparison of diameter frequency showed a significant increase of vessel diameter in both malignant tumors compared to normal tissue (P<0.05). CONCLUSION: The expansion of endothelial cells during tumor angiogenesis is accompanied to a large extent by an increase of vessel diameter rather than by formation of new blood vessels. This may be a possible adaptive mechanism by which experimental pancreatic and hepatocellular cancers expand their endothelial diffusion surface of endothelium to compensate for inadequate neoangiogenesis.

Animals↗

PubMed1991

[A study on the tonsil with focal infections--with special reference to the newly devised tonsillar cryptscope and the architecture of vessels in crypts].

It is well known that inflamed human palatine tonsils have many surface crypts showing characteristic lymphoepithelial symbiosis, which play an important role in immune response. The cryptepithelia are rich in blood vessels. This proliferation of blood vessels is said to be the initiation of various kinds of immune responses. We devised a tonsillar cryptscope in order to observe the tonsillar crypt. Scopy with the cryptscope confirmed seven characteristic types of capillary vessels. The cryptscopic figures showed different patterns in tonsillar diseases such as hypertrophic tonsil, recurrent tonsillitis and tonsil with focal infection (palmoplantar pustulosis and psoriasis vulgaris). In this study the significances of tonsillar cryptscopic figures were investigated through the study of three dimensional structures of blood vessels and immuno-histology. In order to understand the structure of capillary vessels in details, human palatine tonsils were studied using corrosion casting techniques with a scanning electron microscope. Horseshoe type capillary vessels corresponded to the curved capillary vessels in the epithelium. This type of capillary vessel was observed in the epithelia covering the interfollicular area. The tonsillar blood vessels, along with closely related substances in the epithelium and the parenchyma, were immuno-histologically examined. Where the lymphocytes had densely infiltrated the epithelium, the basement membrane became thickened and often disrupted; the endothelial cells were also enlarged. Adrian et al reported that lymphocytes invaded from the capillary vessels within the epithelia. Thus it was suggested that the horseshoe type was related to lymphocyte invasion of the epithelia.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

[Studies on vessel invasion by cancer of the renal pelvis and ureter].

The significance of vessel invasion by cancer of the renal pelvis and ureter was estimated with surgical specimens of 45 patients. The vessel invasion by cancer was observed in 25 out of 45 cases (55.6%). The incidence of vessel invasion increased with the grade of cancer and the extent of the primary tumor. The postoperative metastases by cancer was noted in 22 of the 25 patients with vessel invasion (88%) and in 4 of 20 (20%) patients without vessel invasion. The incidence of metastases in patients with vessel invasion was significantly higher than that without it (p < 0.01). The 5-year survival rate was 13.1% in the patients with vessel invasion and 80.6% in the patients without it (p < 0.005). Postoperative chemotherapy had no effect on the unfavorable outcome of the patients with vessel invasion. Therefore, vessel invasion by cancer may be one of the prognostic factors in renal pelvic and ureteral cancer. The patients with vessel invasion should be treated with more aggressive therapy to improve the poor prognosis.

Adult↗

PubMed2001

Hydraulic properties of individual xylem vessels of Fraxinus americana.

Studies of the hydraulic properties of xylem vessels have been limited to measurements of whole plant or whole stem segments. This approach allows the longitudinal transport properties of the ensemble of vessels within a stem to be determined, but provides little information on radial transport. Here the xylem of Fraxinus americana L. has been examined using a new method that allows the transport properties of individual vessels to be examined. One goal of this study was to quantify transport parameters relevant to embolism repair. The longitudinal conductivity of vessel segments open at both ends (i.e. no end walls) agreed with values predicted by the Poiseuille equation. Radial specific conductance (conductance per unit area) was approximately six orders of magnitude lower than the longitudinal conductance of the vessel segment normalized by the cross-sectional area of the vessel lumen. There was a step increase in the radial specific conductance of previously gas-filled vessels when the delivery pressure exceeded 0.4 MPa. This is consistent with the idea that positive pressure, required for embolism repair, can be compartmentalized within a vessel if the bordered pit chambers are gas-filled. The diffusion coefficient for the movement of gas from a pressurized air-filled vessel was of the same order of magnitude as that for air diffusing through water (1.95 e(-9) m(2) s(-1)). Estimates of the time needed to displace all of the gas from an air-filled vessel were in the order of 20 min, suggesting that gas removal may not be a major limitation in embolism repair.

Biological Transport↗

PubMed2002

Lymphatic vessels in vascularized human corneas: immunohistochemical investigation using LYVE-1 and podoplanin.

PURPOSE: To determine whether lymphatic vessels exist in vascularized human corneas, by using immunohistochemistry with novel markers for lymphatic endothelium. METHODS: Human corneas exhibiting neovascularization secondary to keratitis, transplant rejection, trauma, and limbal insufficiency (n = 21) were assessed for lymphatic vessel content by conventional transmission electron microscopy and by immunostaining and immunoelectron microscopy with antibodies specific for the lymphatic endothelial markers, lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and the 38-kDa integral membrane glycoprotein podoplanin. In addition, corneas were stained for the lymphangiogenic growth factor VEGF-C, and its receptor VEGFR3 by immunohistochemistry and in situ RNA hybridization, respectively. RESULTS: Thin-walled, erythrocyte-free vessels staining with lymphatic markers (LYVE-1 and podoplanin) were found to constitute 8% of all vessels, to be more common in the early course of neovascularization, to be always associated with blood vessels and stromal inflammatory cells, and to correlate significantly with the degree of corneal hemangiogenesis (r = 0.6; P = 0.005). VEGF-C, VEGFR3, podoplanin, and LYVE-1 colocalized on the endothelial lining of lymphatic vessels. With immunogold labeling, LYVE-1 and podoplanin antigen were found on endothelial cells lining vessels with ultrastructural features of lymph vessels. CONCLUSIONS: Immunohistochemistry with novel lymph-endothelium markers and ultrastructural analyses indicate the existence of lymphatic vessels in vascularized human corneas. Human corneal lymphangiogenesis appears to be correlated with the degree of corneal hemangiogenesis and may at least partially be mediated by VEGF-C and its receptor VEGFR3.

Adult↗

PubMed2003

Morphology of umbilical vessels in human fetuses: a quantitative light microscope study.

OBJECTIVE: To investigate the development of the intra-abdominal part of the umbilical vessels in human fetuses by light microscopy. MATERIALS AND METHODS: The location of the umbilicus and umbilical vessels in the abdominal cavity of 90 human fetuses of gestational ages 10-40 weeks was determined. The external vessel diameter, lumen diameter, wall thickness, tunica adventitia thickness, tunica media thickness and the number of vasa vasorum were recorded from cross-sectlons of the intra-abdominal part of the umbilical vessels. 1985). 1985). RESULTS: Umbilical artery agenesis was observed on the left side in two cases and on the right in one case. There was a positive correlation between gestational age and umbilical vessel measurements. There were differences between the vessel and lumen diameters, tunica media thicknesses of the vessels of the second and third trimesters, and the full-term period. There were also predictable differences between the vessel and lumen diameters, tunica media and tunica adventitia thicknesses of the umbilical vein and umbilical arteries. CONCLUSION: Detailed information on quantitative parameters of umbilical vessels at each gestational age may prove helpful in determining pathologies of umbilical vessels and illuminating certain syndromes.

Adult↗

PubMed2006

[18F-FDG PET in the diagnosis of large vessel vasculitis].

INTRODUCTION: Positron emission tomography (PET) is a non-invasive diagnostic method which shows the bio-distribution of positron emitter labelled radiopharmaceuticals in the body. Due to the fact that not only timorous, but in certain conditions also some inflammatory cells may exhibit increased accumulation of 18F-FDG, 18F-FDG PET can be used in the diagnosis of both tumours and certain types of inflammations. OBJECTIVE: The objective of the study is to asses the benefits of 18F-FDG PET in the patients examined for symptoms of fever of uncertain origin whose results suggested the possibility of large vessel vasculitis. SAMPLE AND METHODS: In the years 2003 and 2004, the positron emission tomography centre at Masaryk Oncological Institute in Brno examined 35 patients in order to establish the cause of febrilia using 18F-FDG PET. The suspicion of large vessel vasculitis was based on the detection of high accumulation of radiopharmaceuticals in large vessels walls (in the aorta and the larger outgoing branches). The patients underwent a further standard imaging test to diagnose large vessel vasculitis as follows: CT angiography (CTA) in 4 patients, MR angiography (MRA) in 3 patients and duplex ultrasonography (USG) in 7 patients. A definitive diagnosis of primary autoimmunity of large vessel vasculitis was counter checked histologically or based on a therapeutic test by means of the effect of corticotherapy in immunosuppressive doses. RESULTS: Positive PET findings were recorded in 23 out of 35 patients (65.7%). 11 out of 23 PET positive patients (47.8% of PET positive persons and 31.4% of all patients with febrilia) were suspected to have active large vessel vasculitis based on PET examination. In 10 of the 11 patients, it was possible to perform additional examinations necessary to confirm the diagnosis: a histological test of arteria temporalis in one case, and a therapeutic test using corticotherapy in all 10 cases. Large vessel vasculitis was confirmed in all 10 individuals (2 men and 8 women aged 53-66, median age of 62 years). None of the CTA, MRA or USG examinations in any of the cases detected direct or clear signs ofvasculitis, but 3 CTA and 1 MRA examinations could be considered abnormal. The detection of temporal (giant cell) arteritis based on excision of arteria temporalis superficialis points to the limits of PET examination which is unable to assess veins with a diameter of less than 5 mm. On the other hand, it documents the possibility of extra-cranial damage being proved in this diagnosis with the use PET. In seven of the ten cases, a control PET scan was done during corticotherapy. It showed a drop in the accumulation of radiopharmaceuticals, and therefore a drop in the inflammatory metabolic activity on the walls of the large vessels, which was in line with the drop in the laboratory parameters of the inflammation (FW, CRP). CONCLUSION: Positron emission tomography using 18F-FDG can be used to detect active large vessel vasculitis in patients examined for symptoms of fever of uncertain origin. Apparently, PET can detect cases of large vessel vasculitis where other imaging methods have failed and can be also used to follow the development of vasculitis activity during therapy.

Adolescent↗