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PubMed1981

The significance of atypical vessels and neovascularization in cervical neoplasia.

The relationship between atypical vessels seen colposcopically and dysplasia, carcinoma in situ (CIS), microinvasion, and frank invasion was studied quantitatively. No atypical vessels were found with dysplasia, but 2.8% of patients with CIS had atypical vessels. Half of the patients with microinvasion and all of the patients with frank invasion, in whom the entire zone of transformation was viewed, had atypical vessels. Eight-two percent of the patients with atypical vessels had invasion. The conclusions are: (1) Atypical vessels are not present with dysplasia and rarely present with CIS. (2) Atypical vessels may be associated with microinvasion, but are required for frank invasion to occur. (3) Because atypical vessels are usually associated with invasion, which can be in or near the field of atypical vessels, diagnosis cone biopsy should be performed if atypical vessels are seen and colposcopic biopsies do not show frank invasion. (4) Microinvasion without atypical vessels may be a localized disease.

Adult↗

PubMed1988

Triple vessel coronary angioplasty: acute outcome and long-term results.

Triple vessel coronary angioplasty, defined as angioplasty of one or more lesions in each of the three major coronary arteries (left anterior descending, left circumflex, right coronary artery) was performed in 50 (11%) of 469 patients who had angioplasty of multiple vessels. There were 32 men and 18 women with a mean age of 56 years. All 50 patients had severe three vessel coronary disease and represent approximately 5% of patients with three vessel disease who had revascularization in this institution; 8 (16%) had previous coronary bypass surgery, and 23 (46%) had previous myocardial infarction. Unstable angina was present in 33 patients (66%) and 96% had Canadian Heart Association class III or IV angina; mean left ventricular ejection fraction was 57 +/- 11%. Angioplasty was performed in 176 vessels (3.5 vessels per patient, range 3 to 6) and in 250 lesions (5 lesions per patient, range 3 to 9); angiographic success was achieved in 240 lesions (96%) and 166 vessels (94%). Success in all vessels attempted was achieved in 40 (80%) of the 50 patients. Clinical success (angiographic success associated with clinical improvement) was obtained in all 50 patients in whom triple vessel angioplasty was performed; none of them required urgent bypass surgery and 5 patients (10%) had a non-Q wave myocardial infarction. In four other patients triple vessel angioplasty was planned but not performed because of failure to dilate the primary vessel; urgent bypass surgery was required in one of these, who developed a Q wave infarction. Thus, overall clinical success in 54 patients was 93%; the incidence rate of myocardial infarction was 11%, and that of urgent surgery 1.8%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed2002

Primary lymphatic metastatic spread in testicular cancer occurs ventral to the lumbar vessels.

OBJECTIVES: To analyze whether primary metastatic spread occurs behind the lumbar vessels and whether removal is necessary for accurate staging in diagnostic retroperitoneal lymph node dissection, because dissection of lymphatic tissue behind the lumbar vessels is a challenging maneuver. METHODS: One hundred thirty-nine patients were included in our study. Twenty-nine patients with clinical Stage I tumor underwent laparoscopic staging lymph node dissection, including removal of the lymph nodes behind the lumbar vessels. Sixty-four patients with Stage II testicular cancer were retrospectively examined by computed tomography to determine the localization of the enlarged lymph nodes in relation to the lumbar vessels. On the basis of these results, 49 patients with clinical Stage I underwent laparoscopic lymph node dissection within the same template but without dissection of the lymphatic tissue behind the lumbar vessels. RESULTS: In the first group, 10 of 29 patients had pathologic Stage IIA tumors, with positive nodes exclusively ventral to the lumbar vessels. In group 2, 39 patients with solitary metastatic lesions had enlarged lymph nodes, which were always ventral to the lumbar vessels. Only in 3 of 25 patients with multiple metastases was one enlarged node found behind the lumbar vessels. In group 3, no tumor recurrence either before or behind the lumbar vessels could be found in 46 patients after a mean follow-up of 27.8 months. CONCLUSIONS: On the basis of these data, we believe that primary lymphatic metastatic spread in testicular cancer always occurs ventral to the lumbar vessels. Therefore, the removal of lymphatic tissue behind the lumbar vessels for diagnostic procedures is not necessary.

Humans↗

PubMed2000

Endothelial cells of tumor vessels: abnormal but not absent.

The question of whether some blood vessels in tumors of non-vascular origin are lined by cancer cells has been discussed for many years because of the relevance to metastasis, access of drugs to tumor cells, and the effectiveness of angiogenesis inhibitors. Most evidence favoring the existence of tumor cell-lined vessels has come from observations of standard histopathological tissue sections or from transmission and scanning electron microscopic studies. However, it has been difficult to determine convincingly just how abundant these vessels are in tumors. On the one hand, virtually the entire microvasculature is supposedly lined by tumor cells in aggressive uveal melanomas, assuming the presence of vasculogenic mimicry where tumor cells masquerading as endothelial cells create the channels for blood flow. On the other hand, morphometric studies using immunohistochemistry and green fluorescent protein-transfected tumor cells suggest that human colon cancer cells constitute only 3% of the vessel surface in tumors grown orthotopically in mice. This commentary weighs evidence that cancer cells are located in the wall of tumor vessels and discusses the pitfalls in identifying such vessels. Published data along with new observations illustrate the challenges of making an unequivocal identification of tumor cells in vessel walls. Taken together, current evidence suggests that cancer cells contribute at most only a small proportion of the lining of blood vessels in tumors and may be migrating through vessel walls or exposed by defects in the endothelium. Even in aggressive uveal melanomas, blood flow probably occurs mainly through channels lined by endothelial cells, not tumor cells, and most existing data do not support a functionally significant contribution of vasculogenic mimicry. Innovative new approaches that distinguish pleomorphic tumor cells from abnormal endothelial cells in vessel walls will help to define the incidence and importance of tumor cell-lined blood vessels in drug delivery and metastasis via the bloodstream.

Animals↗

PubMed2003

Mechanism of IL-12 mediated alterations in tumour blood vessel morphology: analysis using whole-tissue mounts.

New blood vessel formation within tumours is a critical feature for tumour growth. A major limitation in understanding this complex process has been the inability to visualise and analyse vessel formation. Here, we report on the development of a whole-tissue mount technique that allows visualisation of vessel structure. Mice expressing green fluorescent protein (GFP) made it possible to easily see GFP(+) vessels within non-GFP-expressing B16 melanoma tumours. The small fragments of tumour used in this technique were also effectively stained with fluorescent probe-conjugated antibodies, allowing characterisation of the vessels based on surface marker phenotype. The vessels within tumour tissue were much more irregular and tortuous compared to those within surrounding normal muscle. B16 tumours stably transfected with the genes for IL-12 were used to assess the effects of this cytokine on tumour growth and vessel formation. The IL-12-expressing tumours grew more slowly and had much smaller blood vessels than the large, webbed vessels characteristic of the parental tumours, effects that were dependent on interferon gamma (IFN-gamma). Vessels in the parental tumours were found to express VEGFR-3, the receptor for VEGF-C and VEGF-D. Expression of this receptor by the endothelial cells of the blood vessels was lost in the cytokine expressing tumours, thus suggesting a mechanism for the antiangiogenic effects of IL-12. The combination of the whole mount technique and the GFP transgenic mice provides a powerful method for visualising tumour vasculature and characterising the effects of agents such as cytokines.

Animals↗

PubMed1992

Effect of chronic hypoxia on rat pulmonary resistance vessels: vasodilatation by atrial natriuretic peptide.

1. We have investigated the vasoreactivity of isolated pulmonary resistance vessels of rats after acclimatization to chronic hypoxia in a normobaric, hypoxic chamber. Vasoconstriction, in response to KCl and prostaglandin F2 alpha, and vasodilation, in response to atrial natriuretic peptide, were studied isometrically in a small-vessel myograph. Resting tensions were set to simulate transmural pressures of 17.5 mmHg or 35 mmHg. 2. There were no significant differences between intergroup internal vessel diameters or maximal contractile responses to either agonist. Both control and chronically hypoxic vessels generated significantly greater active contractions at 35 mmHg than at 17.5 mmHg. There were significant positive correlations between vessel diameter and maximum contractility for both control and chronically hypoxic vessels, but when contraction was expressed as equivalent transmural pressure no correlation existed. 3. There was a significant increase in potency (as measured by the concentration necessary to produce 50% of the maximum response) of KCl in chronically hypoxic vessels compared with control vessels at 35 mmHg, but not at 17.5 mmHg. In contrast, the potency of prostaglandin F2 alpha was significantly increased in chronically hypoxic vessels at 17.5 mmHg, but not at 35 mmHg. Thus the change in contractile responses of vessels from chronically hypoxic animals, in terms of maximal response and potency, is dependent on both resting pressure and agonist used. 4. After exposure to chronic hypoxia, atrial natriuretic peptide induced significantly greater maximal relaxation of pulmonary resistance vessels at both resting pressures, but its potency was unaffected.

Animals↗

PubMed2002

Complementary actions of VEGF and angiopoietin-1 on blood vessel growth and leakage.

Vascular endothelial growth factor (VEGF) and Angiopoietins are families of vascular-specific growth factors that regulate blood vessel growth, maturation and function. To learn more about the effects of these factors in vivo, we have overexpressed VEGF-A or Angiopoietin-1 (Ang1) in two systems in mice, and examined the effects on blood vessel growth and function. In one set of studies, VEGF, Ang1, or both factors, were transgenically overexpressed in the skin under the keratin-14 (K14) promoter. The skin of mice overexpressing VEGF (K14-VEGF) had numerous tortuous, capillary-sized vessels which were leaky to the plasma tracer Evans blue under baseline conditions. In contrast, the skin of mice overexpressing Ang1 (K14-Ang1) had enlarged dermal vessels without a significant increase in vessel number. These enlarged vessels were less leaky than those of wild-type mice in response to inflammatory stimuli. In double transgenic mice overexpressing VEGF and Ang1, the size and number of skin vessels were both increased; however, the vessels were not leaky. In a second set of studies, VEGF or Ang1 was systemically delivered using an adenoviral approach. Intravenous injection of adenovirus encoding VEGF (Adeno-VEGF) resulted in widespread tissue oedema within 1-2 days after administration, whereas injection of Adeno-Ang1 resulted in the skin vessels becoming less leaky in response to topical inflammatory stimuli or local injection of VEGF. The decreased leakage was not accompanied by morphological changes. Thus, overexpressing VEGF appears to promote growth of new vessels accompanied by plasma leakage, whereas overexpressing Ang1 promotes the enlargement of existing vessels and a resistance to leakage. Further understanding of the interrelationship of these factors during normal development could lead to their application in the treatment of ischaemic diseases.

Angiopoietin-1↗

PubMed2001

[Measurement of the diameter of segments of retinal branch vessels in digital fundus images - An experimental study of the method and reproducibility].

PURPOSE: The aim of this study was the evaluation of new algorithms to measure diameter of segments of retinal branch vessels offline in local dependence and independent by observer. Methods 360 flashed fundus images (camera FF 450 ZEISS Germany, Visualis IMEDOS GmbH Weimar/Germany) of 12 eyes of healthy volunteers (10 independent sessions containing 3 images for every eye) were analysed. Algorithms detect the vessel diameter along the vessel course automatically. Corresponding segments of a retinal artery and vein were examined (mean length of the segment 2.5 mm) in every image of one eye. Results The marked arterial segment was detected automatically in 359 pictures and the venous segment in all pictures. The mean vessel diameter was detected in single pictures with a mean coefficient of variation (CV) for arteries of 3.4 % and for veins of 2.7 %. The differences of arterial and venous diameter between images were not significant. Analyzing sessions the CV of the mean vessel diameter were reduced for arteries to 2.7 % and for veins to 2.5 %. The standard deviation of the mean vessel diameter was independent of the vessel diameter (branch vessels with diameter of 120 to 200 micrometer). The mean CV of the vessel diameter at single locations were 5.7 % for arteries and 3.8 % for veins. Conclusions The new algorithms are useful for retinal vessel analysis, if there are no questions concerning the dynamic of vessel behaviour.

Adult↗

PubMed2000

Tumor vessel: a valuable cholangioscopic clue of malignant biliary stricture.

BACKGROUND: An irregularly dilated and tortuous vessel, the so-called tumor vessel, is considered to be one of the cholangioscopic features that suggest biliary malignancy. This is a prospective analysis of the presence of a tumor vessel as a finding that discriminates between benign and malignant biliary strictures. METHODS: From August 1997 to August 1998, a total of 63 patients with biliary strictures diagnosed with endoscopic retrograde cholangiography or percutaneous transhepatic cholangiography obtained during percutaneous transhepatic biliary drainage tube placement were included in this study. Strictures were characterized as benign or malignant based on the observation of tumor vessels. The results were compared with those of percutaneous transhepatic cholangiography-guided biopsy and final diagnosis. RESULTS: Forty-one patients were confirmed to have malignant strictures and 22 had benign biliary strictures. Cancer was confirmed by histopathologic evaluation of biopsies in 33 of 41 patients with malignancy (80.4%). Tumor vessel was seen in 25 of 41 patients with malignancy (61%). No patients with benign stricture had tumor vessels. Of the 8 patients with negative percutaneous transhepatic cholangioscopy-guided biopsies but with a final diagnosis of malignancy, 6 had tumor vessels. Combining the observation of tumor vessel and percutaneous transhepatic cholangiography-guided biopsy resulted in a diagnosis of malignancy in 39 of 41 patients (96%) and significantly increased the rate of preoperative diagnosis when compared with percutaneous transhepatic cholangiography-guided biopsy or presence of tumor vessel alone (p<0.05). CONCLUSION: The presence of tumor vessel may be a valuable cholangioscopic finding that indicates the presence of a malignant biliary stricture. The combination of tumor vessel observation and percutaneous transhepatic cholangiography-guided biopsy may improve the preoperative diagnosis of malignancy.

Adult↗

PubMed2006

Influence of a salinity gradient on the vessel characters of the mangrove species Rhizophora mucronata.

BACKGROUND AND AIMS: Although mangroves have been extensively studied, little is known about their ecological wood anatomy. This investigation examined the potential use of vessel density as a proxy for soil water salinity in the mangrove species Rhizophora mucronata (Rhizophoraceae) from Kenya. METHODS: In a time-standardized approach, 50 wood discs from trees growing in six salinity categories were investigated. Vessel densities, and tangential and radial diameters of rainy and dry season wood of one distinct year, at three positions on the stem discs, were measured. A repeated-measures ANOVA with the prevailing salinity was performed. KEY RESULTS: Vessel density showed a significant increase with salinity, supporting its use as a prospective measure of salinity. Interestingly, the negative salinity response of the radial diameter of vessels was less striking, and tangential diameter was constant under the varying environmental conditions. An effect of age or growth rate or the presence of vessel dimorphism could be excluded as the cause of the absence of any ecological trend. CONCLUSIONS: The clear trend in vessel density with salinity, together with the absence of a growth rate and age effect, validates the potential of vessel density as an environmental proxy. However, it can only be used as a relative measure of salinity given that other environmental variables such as inundation frequency have an additional influence on vessel density. With view to a reliable, absolute proxy, future research should focus on finding wood anatomical features correlated exclusively with soil water salinity or inundation frequency. The plasticity in vessel density with differing salinity suggests a role in the establishment of a safe water transport system. To confirm this hypothesis, the role of inter-vessel pits, their relationship to the rather constant vessel diameter and the underlying physiology and cell biology needs to be examined.

Ecosystem↗

PubMed2003

Air method measurements of apple vessel length distributions with improved apparatus and theory.

Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor conductivity to air of fresh wood segments of different lengths. Theory for determining vessel length distribution was improved to give a single parameter uni-modal vessel length probability density function. The function, derived by combining the exponential extinction (with extinction coefficient k) of wood conductivity to air (C) as wood length (x) increases (i.e. C=Co exp (-kx)) with the differential double difference formula, is Px=xxk2 exp (-kx), where Px is the fraction of vessels of length x. The main parameter of the distribution, k, was found to be the inverse of the mode of the distribution, i.e. the most common vessel length, Lo. Lo for ten apple rootstock and scion varieties varied from 5.6+/-0.1 cm (+/-SE) for MM.111 to 9.0+/-1.0 for Prunifolia (P <0.05). Average maximum vessel length was approximately 50 cm, and differences were not significant. Effective vessel radii ranged from 14 for Prunifolia to 24.3+/-0.7 micro m for M.26, with standard errors less than 12% of the mean. Specific conductivity of a 15 cm wood segment ranged from 2x109-4) to 1.6+/-0.2x10(-2) dm3 s(-1) kPa(-1) m(-1) for maruba and M.26, respectively, with standard errors up to 63% of the mean. Vessel density at the air entry point ranged from 18+/-3 to 42+/-6 vessels mm-2 for M.26 and MM.106, respectively, with standard errors as high as 89% of the mean. It was concluded that there is no general relationship between the wood properties investigated and rootstock size class, and that plasticity increases from vessel lengths to radii to specific conductivity and vessel densities.

Air↗

PubMed1983

Use of anti-basement membrane antibodies to distinguish blood vessel capillaries from lymphatic capillaries.

A new method has been developed for identifying blood vessel capillaries and distinguishing them from lymphatic capillaries. Highly purified antibodies to two ubiquitous components of basement membrane--Type IV collagen and laminin--were applied to fresh-frozen and formalin-fixed tissue sections rich in blood vessel capillaries (granulation tissue), rich in lymphatic channels (small intestine and mesentery), and rich in both (skin, lung, and breast). Staining patterns were evaluated using standard immunofluorescence and immunoperoxidase techniques. Blood vessel capillaries contained intact basement membranes with linear staining for both Type IV collagen and laminin. Lymphatic capillaries, in contrast, uniformly lacked immunoreactivity with antibodies to these basement membrane components. These lymphatic capillaries, which were indistinguishable from blood vessel capillaries in both size (cross-sectional area) and shape (vessel eccentricity), were confirmed as lymphatics by dye injection studies. Our immunohistological technique detected 7-10 times more blood vessels than hematoxylin and eosin staining. Both benign and vessels than hematoxylin and eosin staining. Both benign and malignant tumors of blood vessel endothelium including two capillary hemangiomas and two angiosarcomas demonstrated extracellular linear staining for both Type IV collagen and laminin, whereas two lymphangiomas and two lymphangiectasias were negative. This method then provides a sensitive technique for detecting blood vessel capillaries in tissue sections and a reliable means of distinguishing blood vessel capillaries from lymphatic capillaries. This method may also aid in the identification of tumors whose origin is blood vessel endothelium.

Animals↗

PubMed2005

Reduction of vertebral blood flow by segmental vessel occlusion: an intraoperative study using laser Doppler flowmetry.

STUDY DESIGN: During anterior spinal surgery, vertebral perfusion was assessed by laser Doppler flowmetry. Blood flow changes were assessed after unilateral ligation and contralateral compression of the segmental vessels. OBJECTIVE: To assess the influence of unilateral and bilateral segmental vessel occlusion on vertebral blood flow. SUMMARY OF BACKGROUND DATA: During anterior spinal surgery, segmental vessels are frequently being ligated. The reduced blood supply to the vertebrae may impair intervertebral fusion, and the decreased spinal cord perfusion may lead to ischemic myelopathy. To our knowledge, this is the first in vivo study to investigate vertebral blood flow. METHODS.: There were 10 patients who underwent anterior release for adult idiopathic scoliosis (n = 6), Scheuermann disease (n = 3), and posttraumatic kyphosis (n = 1). A high-power laser Doppler flowmeter was used to assess vertebral blood flow. Measurements were performed in 19 thoracic and 4 lumbar vertebrae (n = 23) after unilateral segmental vessel ligation and additional temporary digital compression of the contralateral vessels. RESULTS: Initial mean blood flow was 49.1 +/- 27.6 arbitrary units, and all signals were pulsatile. The blood flow decreased by a mean of 8% after unilateral ligation of the segmental vessels. With additional compression of the contralateral vessels, the signal heights decreased significantly by 54% (mean 18.3 +/- 7.8 arbitrary units, P = 0.00003), and a loss of the pulsatile pattern was observed in 75% of the vertebrae. On release of digital compression, the signal height as well as the pulsatility promptly returned. CONCLUSIONS: Unilateral ligation of segmental vessels led only to a slight decrease of the vertebral blood flow. Future studies may show whether sparing the segmental vessels during anterior fusion enhances bone graft incorporation, thus decreasing the rate of pseudarthrosis. According to clinical data, the risk of neurologic injury through unilateral ligation is negligible. Bilateral segmental vessel occlusion markedly reduced vertebral bloodflow. Therefore, when treating patients with a higher neurologic risk or in revision cases, the surgeon should always consider sparing the segmental vessels.

Adolescent↗

PubMed2004

Safety zones for anterior abdominal wall entry during laparoscopy: a CT scan mapping of epigastric vessels.

OBJECTIVE: To determine the efficacy of CT scan in mapping the superior and inferior epigastric vessels, relative to landmarks apparent at laparoscopy. SUMMARY BACKGROUND DATA: Trauma to abdominal wall blood vessels occurs in 0.2% to 2% of laparoscopic procedures. Both superficial and deep abdominal wall vessels are at risk. The superficial vessels may be located by transillumination; however, the deep epigastric vessels cannot be effectively located by transillumination and, thus, other techniques should be used to minimize the risk of injury to these vessels. METHODS: Abdominal and pelvic CT images of 100 patients were studied. The location of the superior and inferior epigastric vessels from the midline were determined at five levels, correlated with each other and with the patient age, body mass index, and history of midline laparotomy using Pearson's correlation coefficient and multivariate analysis. RESULTS: CT scan was successful in mapping the epigastric vessels in 95% of patients. At the xiphoid process level, the superior epigastric vessels (SEA) were 4.41 +/- 0.13 cm from the midline on the right and 4.53 +/- 0.14 cm on the left. Midway between xiphoid and umbilicus, the SEA were 5.50 +/- 0.16 cm on the right of the midline and 5.36 +/- 0.16 cm on the left. At the umbilicus, the epigastric vessels were 5.88 +/- 0.14 cm on the right and 5.55 +/- 0.13 on the left of the midline. Midway between the umbilicus and symphysis pubis, the inferior epigastric (IEA) were 5.32 +/- 0.12 cm on right and 5.25 +/- 0.11 cm on the left. At the symphysis pubis, the IEA were 7.47 +/- 0.10 cm on the right and 7.49 +/- 0.09 cm away from the midline on the left side. CONCLUSIONS: Epigastric vessels are usually located in the area between 4 and 8 cm from the midline. Staying away from this area will determine the safe zone of entry of the anterior abdominal wall.

Abdominal Wall↗

PubMed2004

Desmoplakin and Plakoglobin--specific markers of lymphatic vessels in the skin?

Monoclonal antibodies against Desmoplakin and Plakoglobin were tested for their suitability as specific markers of lymphatic vessels. The tissue samples were taken from horse skin in an attempt to establish the horse as a model for human lymphatic diseases. To obtain a clear, positive identification of blood and lymphatic vessels, immunohistochemical staining with antibodies against vascular endothelial growth factor receptor 3 (VEGFR-3) and platelet endothelial adhesion molecule (PECAM-1, CD31), was compared with Desmoplakin and Plakoglobin. Because anti-VEGFR-3 is specific for lymphatic vessels in the skin while anti-CD31 stains blood and lymphatic vessels as well, it can be concluded that VEGFR-3(-)/CD31(+) vessels are blood vessels and VEGFR-3(+)/CD31(+) vessels are lymphatic vessels. It was documented on serial sections that Plakoglobin stains both blood and lymphatic vessels. However, Desmoplakin did not stain several positively identified lymphatic vessels. Therefore, Desmoplakin and Plakoglobin antibodies are not specific markers of lymphatic vessels in the skin and the staining pattern is tissues and species dependent.

Animals↗

PubMed2006

Wood density and vessel traits as distinct correlates of ecological strategy in 51 California coast range angiosperms.

Wood density and vessel characteristics are functionally interrelated, yet they may have distinct ecological associations. In a comparative study of 51 angiosperm species ranging from chaparral shrubs to riparian trees, we examined relationships among wood density and vessel traits and their ecological correlates. Mean vessel lumen area and vessel density (number mm(-2)) varied widely (7- to 10-fold). In multivariate analyses, both vessel traits were negatively correlated with wood density, which varied more narrowly (< 2-fold). Vessel density and lumen area were inversely related across species, allowing a broad range of vessel traits within a narrow range of wood density. Phylogenetic independent contrasts indicated correlated inverse evolutionary change in vessel traits. Each trait had a distinct pattern of ecological correlation -- wood density was most strongly associated with soil water, and vessel traits showed contrasting relationships with plant height. Within a narrow range of wood density, there was significant variation in vessel traits. Given their particular ecological associations, the results suggest that wood density and vessel traits describe two distinct ecological axes.

Biological Evolution↗

PubMedDate not supplied

Selective vessel ligation in the pelvis: an invaluable tool in certain surgical procedures.

While developing the technique of abdominal radical trachelectomy for conservative cervical cancer management, the vascular supply of the uterus was thoroughly examined. The question of how many vessels the uterus requires to ensure its viability arose. Following an abdominal radical trachelectomy for stage IB cervical carcinoma, blood supply of the body of the uterus is successfully maintained by only the two infundibulopelvic vessels (n= 34). Pregnancy has resulted following this technique (n= 2). Selective ligation of the pelvic vasculature has been utilized in the abdominal radical trachelectomy procedure. The objectives of this study were to investigate the vasculature of the infundibulopelvic and broad ligaments, to assess the contribution of the ovarian and uterine vessels to overall uterine perfusion, and to consider the clinical applications of selective pelvic vessel ligation. Ten fresh dissections of the infundibulopelvic vessels, broad ligaments of benign total abdominal hysterectomy, and bilateral salpingo-oophorectomy specimens were performed. Perfusion index (PI) and oxygen saturation (O(2)Sat) measurements using a modified probe were taken at specified intervals at the uterine cornu during ten routine benign abdominal hysterectomies to assess the contribution of the ovarian and uterine vessels to overall uterine perfusion and the concepts studied were utilized in certain gynecological procedures. The ovarian/infundibulopelvic vessels course medially through the broad ligament toward the uterine cornu and consistently give off a branch to the ovary on its lateral border. In addition, further vessels were noted to run laterally from the uterine cornu along the ovarian ligament to the medial aspect of the ovary. PI and O(2)Sat measurements imply that the uterine and ovarian vessels contribute almost equally to uterine perfusion. Clinical application by selective ligation of the pelvic vasculature has been utilized in certain gynecological procedures often prone to torrential life-threatening uterine hemorrhage. Selective temporary ligation of the uterine and ovarian vessels has proven useful in the surgical management of chemoresistant gestational trophoblastic disease, in the Strassman procedure, fertility-sparing surgery in ruptured cornual ectopic pregnancies, and unrelenting postpartum hemorrhage. Of the six supplying vessels (ovarian, uterine, and vaginal) to the uterus only two (ovarian or uterine or a combination thereof) are required for uterine viability.

Female↗

PubMed2002

Vessel size measurements in angiograms: a comparison of techniques.

As interventional procedures become more complicated, the need for accurate quantitative vascular information increases. In response to this need, many commercial vendors provide techniques for measurement of vessel sizes, usually based on derivative techniques. In this study, we investigate the accuracy of several techniques used in the measurement of vessel size. Simulated images of vessels having circular cross sections were generated and convolved with various focal spot distributions taking into account the magnification. These vessel images were then convolved with Gaussian image detector line spread functions (LSFs). Additionally, images of a phantom containing vessels with a range of diameters were acquired for the 4.5", 6", 9", and 12" modes of an image intensifier-TV (II-TV) system. Vessel sizes in the images were determined using a first-derivative technique, a second-derivative technique, a linear combination of these two measured sizes, a thresholding technique, a densitometric technique, and a model-based technique. For the same focal spot size, the shape of the focal spot distribution does not affect measured vessel sizes except at large magnifications. For vessels with diameters larger than the full-width-at-half-maximum (FWHM) of the LSF, accurate vessel sizes (errors approximately 0.1 mm) could be obtained by using an average of sizes determined by the first and second derivatives. For vessels with diameters smaller than the FWHM of the LSF, the densitometric and model-based techniques can provide accurate vessel sizes when these techniques are properly calibrated.

Angiography↗