Numerous Microvessels Research Articles

The use of rhBMP2 for augmentation of established horizontal/vertical defects may require additional use of rhVEGF to achieve significant bone regeneration: An in vivo experimental study.

To test the hypothesis that the use of rhBMP2 in established defects requires additional growth factors such as rhVEGF to accomplish effective bone repair. Horizontal/vertical defects of 2cm length and 1cm height were created bilaterally in the alveolar crest of the maxillae of 18 minipigs together with the extraction of all premolar teeth and one molar tooth on both sides. After 3months of healing, defects were augmented with 0.5g particulate PDLLA/CaCO3 composite loaded with 400µg rhBMP2/50µg rhVEGF165 on one side and 800µg rhBMP2 on the other in 12 test animals, whereas defects in six control animals were sham operated and left unfilled on one side and augmented with blank carriers on the other. After 4 and 13weeks, the animals were evaluated each for area of new bone formation (mm²) and bone density (area %). Augmentations with carriers loaded with 800g µrhBMP2 failed to induce significantly more bone than in the augmentations with unloaded carrier after 4 and 13weeks (p=.1000, p=.381). Augmentations with carriers loaded with 400µg rhBMP2 and 50µg erhVEGF165 resulted in significantly increased bone formation after 13weeks (p=.024) compared to blank carriers. Soft tissue in augmentations with combined rhBMP2/rhVEGF165 loading exhibited numerous microvessels compared to soft tissue in augmentations with rhBMP2. It is concluded that effective bone regeneration in augmentations of established alveolar ridge defects may require the application of rhVEGF additionally to rhBMP2.

Vascular occlusion by neutrophil extracellular traps in COVID-19.

BackgroundCoronavirus induced disease 2019 (COVID-19) can be complicated by severe organ damage leading to dysfunction of the lungs and other organs. The processes that trigger organ damage in COVID-19 are incompletely understood.MethodsSamples were donated from hospitalized patients. Sera, plasma, and autopsy-derived tissue sections were examined employing flow cytometry, enzyme-linked immunosorbent assays, and immunohistochemistry.Patient findingsHere, we show that severe COVID-19 is characterized by a highly pronounced formation of neutrophil extracellular traps (NETs) inside the micro-vessels. Intravascular aggregation of NETs leads to rapid occlusion of the affected vessels, disturbed microcirculation, and organ damage. In severe COVID-19, neutrophil granulocytes are strongly activated and adopt a so-called low-density phenotype, prone to spontaneously form NETs. In accordance, markers indicating NET turnover are consistently increased in COVID-19 and linked to disease severity. Histopathology of the lungs and other organs from COVID-19 patients showed congestions of numerous micro-vessels by aggregated NETs associated with endothelial damage.InterpretationThese data suggest that organ dysfunction in severe COVID-19 is associated with excessive NET formation and vascular damage.FundingDeutsche Forschungsgemeinschaft (DFG), EU, Volkswagen-Stiftung

Characterization and distribution of sialic acids in human testicular seminoma

Aberrant content of sialic acids (Sias) has been observed in various human cancer types in different organs. Sias have been implicated in cancerous transformation, invasiveness and metastasis, and in the escaping of cancer cells from immune surveillance. Indeed, Sias are commonly regarded as important biomarkers to distinguish cancer cells from their healthy counterparts. However, scarce and not exhaustive investigations have been performed on Sia content in testicular cancers and, in particular, in seminoma, one of the most common malignant testicular tumors. Hence, the aim of this study was to investigate the content and distribution of Sias with different glycosidic linkage, namely α2,3 and α2,6 galactose- or N-acetyl-galactosamine-linked Sias and polymeric Sia (polySia), in the germinal and stromal components of human testes affected by seminoma compared to normal testicular tissue. Structural changes in seminoma tissue were examined using hematoxylin-eosin staining. α2,3 and α2,6 linked Sias were evaluated by lectin histochemistry (Maackia amurensis agglutinin (MAA) and Sambucus nigra agglutinin (SNA)), while confocal immunofluorescence was used for polySia detection. Histopathological findings in seminoma tissue included loss of seminiferous tubules replaced by clusters of uniform polygonal cells with a clear cytoplasm, bundles of fibrotic tissue, numerous microvessels and some atrophic tubules. The content of α2,3 and α2,6 linked Sias was lost in almost all seminoma components respect to normal tissue, with the exception of microvessels in which it was higher. On the contrary, polySia level was increased in all the seminoma components compared to normal testicular tissue. Our findings suggest that an aberrant content of different Sias might have important and differential roles in seminoma development and progression. In particular, polySia might be implicated in seminoma progression by promoting cancer invasiveness and regulating the cross-talk between cancer cells, reactive stroma and vessels. Thus, the possibility that polySia might represent an important biomarker for seminoma deserves further investigation.

Angiogenic activity in vivo of the particulate matter (PM10)

BackgroundParticulate matter (PM) is the most efficient vehicle for the inhalation and absorption of toxic substances into the body. MethodThe present study was aimed at testing the hypothesis that PM10 samples collected on quartz filters exert an angiogenic activity in vivo in the chick embryo chorioallantoic membrane (CAM) assay. ResultsWhen the low, medium, and high PM10 concentrations filters were tested in the CAM assay, an increasing number of microvessels was detectable after 4 days of applications of the filters. Moreover, at histological level, numerous microvessels and a dense inflammatory infiltrate were recognizable in the CAM mesenchyme. ConclusionOur data show a clear dose-response relationship between the dose variable (PM10 and Bap) and the outcome variable. So far, the PM10 target value is determined on the basis of regulatory agreements and is not health-based. In addition, the mere gravimetric measure of PM10 cannot be considered a fully reliable surrogate of the overall toxicity of the mixture.

Primary vaginal leiomyosarcoma, a rare tumour: case report and review

Primary vaginal leiomyosarcomas (pvLMS) are rare, recurrent tumours accounting for ca. 2% of all vaginal cancers. The etiology is still unknown, the prognosis is poor and there is no consensus guideline on its management. Diagnosis is usually made during the 5th decade due to the presence of a vaginal mass or nodule [1-2]. Current medical literature reports about 200 cases (PubMed®); only 3 studies have considered the ultrastructure [2-4]. Herein a pvLMS is presented and discussed. A nodular, 25 x 23 x 28 mm-mass, infiltrating the urethra but not the rectovaginal septum, was widely excised from the superior vaginal wall of a 58-year-old previously hysterectomized woman. Macroscopic images and MRI were performed. Iliac lymph nodes and HMB-45 were negative. The sample was fixed and prepared for light microscopy, transmission (TEM) and scanning (SEM) electron microscopy. Semithin sections showed a storiform pattern of spindle shaped cells with blunt-ended nuclei. Cells arranged in interwoven fascicles within a dense and richly vascularised stroma (neoangiogenesis). Some atypic mitotic figures and focal necrosis were seen. SEM evidenced a dense collagenous stroma with numerous microvessels. TEM showed neoplastic and pleomorphic cells with complex cytoplasm projections containing paranuclear crowds of dilated mitochondria, free ribosomes and a well-developed rough endoplasmic reticulum. Nuclei were large, mostly hyperchromatic, usually indented, with prominent nucleoli and nucleolonema. The dense intercellular space contained dense bundles of collagen fibers. A high and reactive endothelium lined blood vessels. After 4 follow-ups, the patient is fine and without recurrence. Best outcomes occur when the tumour is small, localized, and can be removed surgically with wide, clear margins, as it was for this case. As there are different kinds of LMS, biopsy followed by immunohistochemistry and electron microscopy still represents a good diagnostic choice.

T19: The immune and vascular components of microenvironment in prognosis of the endometrioid endometrial adenocarcinoma

Background Endometrioid endometrial adenocarcimoma is the most frequent gynecologic malignancy in the western world. It is well known that inflammation plays a key role in the initiation and development of cancer as well as promotes both specific and innate immune response. There is no information on the status of the local anti-tumor cellular immunity in endometrioid adenocarcinoma of the corpus uteri microenvironment in the Russian and English language medical scientific literature. Various studies have shown that high intratumor microvessel density in endometrial cancer is associated with advanced stage, increased risk of recurrent disease and with poor prognosis. Vascular endothelial growth factor (VEGF) is a glycoprotein with potent mitogenic activity. It has been demonstrated to be a key component in the promotion of angiogenesis. Materials and methods There were singlet 24 cases of endometrioid adenocarcinoma with retrospectively known good (survival) and poor (death) outcomes. All cases were immunohistochemically stained for CD3, CD20, CD57, CD68, S100, CD34 and VEGF, expression of was evaluated by IHC-profiler. The number and the area of vessels was count in “hot spot” zones and calculated per 1 mm. For compare of the characteristics of signs was used comparison of two independent samples – U-Mann–Whitney test. The level of statistical significance was accepted by p Results T-lymphocytes cells were situated predominantly in desmoplastic stroma of the tumor. CD3 expression was significant higher in the group of good outcome (p = 0.00042), B-lymphocytes cells were predominantly in epithelial component of tumor. CD20 was expressed in endometriod adenocarcinoma with good and poor outcome without statistically significant difference (p = 0.976). NK-lymphocytes were predominantly in peritumoral stroma. CD57 expression was statistically significant higher in the group of good outcome (p = 0.000307). Tumor infiltrating macrophages can were frequent in tumor stroma than in tumor islets. CD68 expression cells number was higher in the group with good outcome (p = 0.000219). Dendric cells were predominantly in epithelial component of tumor. S100+ cells number did not have any difference (p = 0.105). Inside the tumor stroma, among pseudo-glands or solid beaches there was a positive reaction for anti-CD34 of numerous microvessels together with groups of endothelial cells (“hot spot”). The number of intratumoral vessels in patients with poor outcome was 141.9 ± 24.7 vessels/mm2, in good outcome patients – 93.8 ± 28.7 vessels/mm2. The number of the intratumoral vessels in this groups was with significant statistical different (p = 0.0014). The area of intratumoral vessels in good outcome cases was 2799.7 ± 535.7 μm2, poor outcome cases – 5455,2 ± 448,8 μm2. It was significant statistical different (p = 0.000014). VEGF was expressed in the cytoplasm of normal endometrial cells, neoplastic ones, endothelial cells and stroma. VEGF represents a mitogen for endothelial cells that induces the formation of lumen’s vessels and also increases vascular permeability and protein extravasation. Expression of VEGF by cancer cells had significant statistical difference in this groups of patients (p = 0.0411). Conclusion There was a significant reduction in T, NK-cells and macrophages from patients with poor outcome indicates the development of local immune deficiency that could certainly plays an important role in tumor progression endometrioid carcinoma. Our study demonstrates that the number and the area of vessels, as part of angiogenesis, represent an important prognostic factor in outcome of endometrioid endometrial adenocarcinoma. VEGF expression also is an angiogenic factor which plays a great role in the prognosis of this tumor.

“Vicious circles” of glioblastoma tumors: vascularization and invasiveness

Glioblastoma multiforme is the most common and a particularly aggressive form of glial primary brain tumors. This malignancy accounts for ca. 70% of all diagnosed cases. Unfortunately, average survival of glioma patients does not exceed one year from diagnosis. Specific vascularization pattern (presence of numerous microvessels and glomerular vessels) and exceptional invasiveness are characteristic features of glioblastoma tumors. Both of these features reflect complex underlying processes forming two vicious circles. Common to both of these circles is the state of tumor underoxygenation. Hypoxia that occurs in the vicinity of abnormal tumor blood vessels stimulates formation of novel microvessels and invasiveness of tumor cells. In their essence, both of the vicious circles are processes allowing tumor cells to adapt to an underoxygenated tumor milieu. These processes play an important role in tumor progression, which reflects a specific type of evolution of cancer cells. Late effects of this evolution include appearance of highly aggressive, chemo- and radiotherapy resistant neoplastic cells. Increased adaptation capabilities of such cancer cells have a negative influence on the therapeutic process. Effective therapeutic strategies should not be directed against single cancer cell markers; instead, they should be targeted so as to break both vicious cycles. Herein we discuss several such strategies. In our opinion, effective therapeutic approaches must include a combination of several agents that recognize and simultaneously break both vicious cycles, i.e. vascularization and invasiveness. Also, agents that decrease hypoxia in cancer cells, for example drugs inhibiting activity of HIF-1α, might also prove therapeutically effective in such approaches.

Microvascular imaging of asymptomatic MCA steno-occlusive patients using ultra-high-field 7T MRI

It is common that physicians are faced with patients who have severe steno-occlusion of intracranial arteries in the absence of clinical symptoms. This study is to determine whether a 7T magnetic resonance angiogram (MRA) could provide the improved depiction of microvessels of asymptomatic patients with steno-occlusive middle cerebral artery (MCA) and possible clues for diagnosis of their clinical symptoms. All the patients who were identified as severe MCA steno-occlusions underwent a 7T MRA study. Three of these also underwent conventional angiography (TFCA). The vascular densities around the steno-occlusive MCA and posterior cerebral artery (PCA) branches as control vessels were measured and the difference between the median values of 7T and 3T MRA data was also analyzed. The results of 7T MRA revealed numerous microvessels not visible by conventional MRA. These 7T MRA images were also comparable to those obtained by an invasive conventional angiography (TFCA). The median values of vascular densities observed by 7T MRA were significantly higher than those by 3T MRA (5.28 at 7T vs. 1.45 at 3T for steno-occlusive MCA, p = 0.012, while 3.39 at 7T vs. 3.32 at 3T for normal PCA, p = 0.093). Ultra-high-field 7T MRA is a totally noninvasive angiographic technique that is capable of visualizing microvascular circulation that is usually difficult with conventional MRA. This visualization technique, therefore, could provide an important avenue on the diagnosis of steno-occlusion as well as the search of the roles of the microvessel, especially collaterals, in the preservation of normal blood circulation in patients with asymptomatic MCA steno-occlusion.

Dermoscopic features of nonpigmented eccrine poromas in association with their histopathological features

Nonpigmented eccrine poromas (EPs) occasionally mimic various skin tumours, but their dermoscopic features have not been clarified. To evaluate the dermoscopic features of nonpigmented EPs in association with their histopathological features. Retrospective analysis of the dermoscopic features of 10 histopathologically proven cases of nonpigmented EP at the Department of Dermatology, Shinshu University Hospital (Matsumoto, Japan). Specific features in vascular structures were observed in five of 10 nonpigmented EPs. Three cases showed a polymorphous vascular pattern: two cases of a combination of hairpin and dotted vessels, and one case of a combination of hairpin, dotted and linear-irregular vessels. In addition, there were two cases of monomorphous vascular pattern: one case of linear-irregular vessels, and one case of hairpin vessels. We did not observe arborizing, crown or comma vessels. Comedo-like openings, milia-like cysts, cerebriform pattern and ulceration were observed in one case each. Furthermore, nine of 10 cases showed the characteristic feature, described as well-circumscribed reddish globule/lacuna-like structures with separation of mesh bands, which were reminiscent of frog eggs aggregation. This characteristic feature on dermoscopy was explained by the histopathological features of horizontal sections at a depth of 300-400 μm from the surface. Island-shaped oedematous stroma with numerous microvessels, which were surrounded by poroid cells in mesh-like forms, were seen. Vascular structures and 'frog eggs-like appearance' are important features on dermoscopic examination of nonpigmented EP. Further studies are required to evaluate their diagnostic accuracy to differentiate nonpigmented EP from other tumours.

Perivenous application of fibrin glue prevents the early injury of jugular vein graft to arterial circulation in rabbits

Placement of an external support has been reported to prevent intimal hyperplasia of vein grafts. However, it is limited by potential complications. In the present study, we investigated the effect of fibrin glue on preventing vein graft failure as perivenous application. Twenty-four rabbits were divided into non-supported group (n = 12) and fibrin glue group (n = 12). All animals underwent unilateral jugular vein into common carotid artery interposition grafting and then fibrin glue was applied as perivenous support. Samples of tissues were harvested after 4 weeks. The vein grafts with fibrin glue demonstrated a statistically significant decrease in proliferating cell nuclear antigen in the medial/intimal region [13.38% (11.26% - 15.11%)] compared with non-supported vein grafts [31.22% (27.15% - 35.98%)] (P < 0.001). Light microscopy showed remarkable attenuation of endothelial cell loss and numerous microvessels in neoadventitia in the fibrin glue group compared with the non-supported group. The smooth muscle cells migrated into adventitia significantly in fibrin glue group, whereas the smooth muscle cells migrated into intima in non-supported group. Conclusion Perivenous support of vein graft with fibrin glue in vivo can attenuate the severe injury encountered in the non-supported vein grafts exposed to artery.

Angiogenesis in intracranial meningiomas: immunohistochemical and molecular study.

Much of the morbidity of intracranial meningiomas is related to the degree of tumour vascularity and the extent of peritumoural vasogenic oedema. Several studies have shown that vascular endothelial growth factor (VEGF) is up-regulated in meningiomas, although its relationship with tumour vasculature is still unclear. In order to better understand the angiogenic assessment of intracranial meningiomas, we analysed its vascular pattern, both as number and as morphologic configuration of microvessels. Moreover, we investigated the mRNA-VEGF expression, relating this expression to vascular pattern. A total of 40 intracranial meningiomas, classified as benign (31 cases), atypical (7 cases), and anaplastic (2 cases) were analysed. RT-PCR analyses of mRNA-VEGF and competitive-PCR were performed. VEGF expression and microvessel density (MVD) were also immunohistochemically investigated. Grade II-III meningiomas showed numerous small microvessels (mean: 34), while the majority of Grade I showed few larger vessels (mean: 13.09) (P = 0.000003). A microvessel pattern overlapping into atypical subtype was found in eignt of the 31 (25.8%) Grade I meningiomas. A significant association was found between grading and vascular pattern (P = 0.0002), as well as between the MVD and the immunohistochemical expression of VEGF (P = 0.0005). The expression of mRNA agreed with the immunohistochemical expression of the protein (P < 0.0001). A total of 39 cases expressed the 121 VEGF isoform and, among these, 28 cases also expressed the 165 isoform. Only 9 cases expressed both isoforms 165 and 189. Grade II and III meningiomas showed a preponderant expression of soluble isoforms (121 and 165). These results prompt us to speculate that the microvessel pattern could underlie a higher metabolic demand, probably due to a rapid growth with a consequent worse clinical behaviour of the tumour. In this sense, the vascular pattern may be used as a prognostic factor, in order to mostly focus attention on those Grade I meningiomas which have a higher likelihood of either recurrence or development of perilesional oedema. The pattern of vasculature itself seems to be dependent on the types of VEGF isoforms: the Grade II-III meningiomas (that presented numerous microvessels) expressed the soluble isoforms 121 and 165, while the isoform 189 was more frequently detected in Grade I meningiomas.

Action of microparticles of heparin and alginate crosslinked gel when used as injectable artificial matrices to stabilize basic fibroblast growth factor and induce angiogenesis by controlling its release.

Alginate is an acidic polysaccharide like the glycosaminoglycans and is a candidate for use as an artificial matrix. We developed a novel alginate gel sheet that is crosslinked with heparin (H/A gel sheet) and discovered its properties of releasing biologically active basic fibroblast growth factor (bFGF), a representative member of the heparin-binding growth factors (HBGFs), for about 1 month in vitro and of inducing angiogenesis in vivo. In the present study, the H/A gel sheet was mechanically broken up to produce easily injectable 50- to 200 microm microparticles of the gel (H/A gel particles), the properties of which were analyzed. The H/A gel particles cumulatively released 2.8 times as much bFGF as the H/A gel sheet, despite both having the same amount of bFGF adsorbed onto their gels. In addition, the bFGF-adsorbed H/A gel particles released a significant amount of bFGF, which stimulated cellular growth in a culture of human umbilical venous endothelial cells for up to 5 weeks. The subcutaneous injection of the bFGF-adsorbed H/A gel particles induced the formation of numerous microvessels in the tissue surrounding the gel. These results indicate that the H/A gel particles not only stabilize bFGF by preventing the occurrence of proteolysis or denaturation but also modulate its release from the gel. Because the H/A gel particles can be easily injected into the target tissues, this artificial matrix may be useful for the local delivery of HBGFs in the treatment of ischemic arterial diseases, as well as for regenerating or constructing tissues.

Inhibition of angiogenesis-related endothelial activity by the experimental immunosuppressive agent leflunomide.

Leflunomide, an inhibitor of protein kinase activity and pyrimidine synthesis, is an experimental immunosuppressive agent effective in the prevention/control of acute and chronic rejection in animal models and currently in phase I clinical trials in human transplant recipients. This agent is also effective in the control of graft-versus-host disease, autoimmune reactions, and the growth of certain tumors. The importance of the endothelium in these disease processes led us to hypothesize that leflunomide might act directly upon the endothelial cell (EC). Assay of human EC colony formation demonstrated dose-dependent, leflunomide-mediated inhibition of EC proliferation. In addition, the organization of EC into capillary-like networks, which occurs during 18 hr of incubation on Matrigel, was progressively disrupted with increasing concentrations of leflunomide. Finally, fibrin-embedded transverse sections of murine aorta, which sprout numerous microvessels during an 11-day incubation, were inhibited from doing so in the presence of this agent. All drug concentrations used in these experiments were nontoxic and pharmacologically relevant, and none of these effects were reversible by exogenous uridine, implying that inhibition of these processes was not due to intracellular pyrimidine depletion. Furthermore, neither cyclosporine nor tacrolimus exerted inhibitory activity in any of the experiments described above. Data generated by these studies distinguish leflunomide among immunosuppressants as uniquely capable of inhibiting angiogenesis-related endothelial functions and suggest additional mechanisms by which this agent might intervene in the diverse array of disease processes against which it has shown therapeutic potential.

Endolymphatic Sac Tumor Associated with a Von Hippel-Lindau Disease Patient: An Immunohistochemical Study

The authors report a case of endolymphatic sac tumor (ELST) associated with Von Hippel-Lindau disease (VHL). A 20-year-old female VHL patient received a resection of a cerebellar hemangioblastoma 3 years ago and she had a co-existing of left petrous tumor. The petrous tumor showed a remarkable progression in 3 years and was resected subtotally. Histologically, the resected petrous tumor showed a papillary structure containing cuboidal or columnar cells with fibrous stroma and numerous microvessels and destructed temporal bone, all of which are consistent with ELST. We studied the expression of various kinds of cytokeratins (CKs) immunohistochemically and found distinct expression of CKs (CAM 5.2, 34βE-12, CK7, CK8 and CK19), but not for CK10/13 or CK20. Vascular endothelial growth factor and neuron specific enolase showed strong immunoreactivity in the tumor cells. CD34 also had weak expression. Ki-67 antigen (MIB-1) immunoreactivity was found in focal areas, and the labeling index in the highest-density area was 48.9%. These findings suggest that vascular endothelial growth factor overexpression is an important factor for angiogenesis in ELST, much like other VHL-associated tumors, and that ELST may have a more highly aggressive component than the low-grade malignancy noted in previous reports.

Cell proliferation, cell death, E-cadherin, metalloproteinase expression and angiogenesis in gastric cancer precursors and early cancer of the intestinal type.

The aim of this study was to analyse the morphological, kinetic and molecular characteristics of low-grade (LGD) and high-grade dysplasias (HDG) in comparison with intestinal metaplasia type III (IM III) and normal mucosa (NM) as well as with early gastric cancer of the intestinal type (EGC). Based on this it was verified whether these categories are distinct, progressive proliferative steps from IM III to LGD, HGD and EGC, according to Correa's sequence of events. The morphology, mitotic index (MI), and the apoptotic index (AI) were assessed. The E-cadherin expression (E-Cad), matrix-metalloproteinase activity (MMP2), and the number of microvessels (NV) were also evaluated. Among the categories, MI increases from NM to IM III and LGD, and from LGD to HGD and EGC, while AI continues to increase also from HGD to EGC. E-cad decreases from NM to EGC, although not significantly from LGD to HGD; MMP2 is significantly more expressed only in EGC. Three groups are obtained by means of cluster analysis. The first group includes all the NMs and IM IIIs, all except 1 LGD, about half of HGDs, and 1 EGC. E-Cad is highly expressed, MMP2 and angiogenesis are low, the proliferative activity is low and mitoses are partly balanced by apoptoses. The second group includes some EGCs and HGDs and is characterised by a very high proliferative activity and cell death; there is an initial loss of cell adhesion, an increase of MMP2 and NV. The third group includes the majority of EGCs, but also 1 HGD: it has intermediate MI and AI, the lowest expression of E-Cad, the highest expression of MMP2 and the most numerous microvessels. These results underscore the necessity of evaluating each case individually within the same singular category of Correa's sequence. The use of kinetic and molecular parameters in addition to the morphological analysis may give important information on the behaviour of the various lesions.

'ACE inhibitors are better than AT(1) receptor blockers (ARBs)' - controversies in heart failure.

'ACE inhibitors are better than AT(1) receptor blockers (ARBs)' - controversies in heart failure.

Immunohistochemical and Ultrastructural Study of Microvessels in Diabetic Veins

The aim of this study was to examine the localization and features of the intramural microvessels in the wall of inferior limb veins in diabetic patients. The study was conducted in a group of 10 insulin-dependent diabetic patients, who had suffered inferior limb amputation as a consequence of chronic limb ischemia. Sections of long saphenous and posterior tibial veins were investigated by light and transmission electron microscope. The von Willebrand factor and albumin were detected by immunohistochemical techniques. The results show the presence of numerous microvessels in the intima and inner third of the media layer of the venous wall of the sections studied. These microvessels present morphological and functional modifications in relation to those observed in the control veins. They also showed the presence of endothelial cells migrating from the lumen. The authors conclude that the venous wall of inferior limbs in amputated diabetic patients presents a neovascularization process. Some of the endothelial cells of the venous lumen can also have a role in the angiogenesis.