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Vascular Spaces (vascular + space)
Selected AbstractsRemodeling and Vascular Spaces in BoneJOURNAL OF BONE AND MINERAL RESEARCH, Issue 1 2007Erik Fink Eriksen Abstract In recent years, we have come to appreciate that the close association between bone and vasculature plays a pivotal role in the regulation of bone remodeling and fracture repair. In 2001, Hauge et al. characterized a specialized vascular structure, the bone remodeling compartment (BRC), and showed that the outer lining of this compartment was made up of flattened cells, displaying all the characteristics of lining cells in bone. A decrease in bone turnover leads to a decrease in surfaces covered with remodeling compartments, whereas increased turnover causes an increase. Immunoreactivity for all major osteotropic growth factors and cytokines including osteoprotegerin (OPG) and RANKL has been shown in the cells lining the BRC, which makes the BRC the structure of choice for coupling between resorption and formation. The secretion of these factors inside a confined space separated from the bone marrow would facilitate local regulation of the remodeling process without interference from growth factors secreted by blood cells in the marrow space. The BRC creates an environment where cells inside the structure are exposed to denuded bone, which may enable direct cellular interactions with integrins and other matrix factors known to regulate osteoclast/osteoblast activity. However, the denuded bone surface inside the BRC also constitutes an ideal environment for the seeding of bone metastases, known to have high affinity for bone matrix. Reduction in BRC space brought about by antiresorptive therapies such as bisphosphonates reduce the number of skeletal events in advanced cancer, whereas an increase in BRC space induced by remodeling activators like PTH may increase the bone metastatic burden. The BRC has only been characterized in detail in trabecular bone; there is, however, evidence that a similar structure may exist in cortical bone, but further characterization is needed. [source] Two-component diffusion tensor MRI of isolated perfused heartsMAGNETIC RESONANCE IN MEDICINE, Issue 6 2001Edward W. Hsu Abstract Nonmonoexponential MR diffusion decay behavior has been observed at high diffusion-weighting strengths for cell aggregates and tissues, including the myocardium; however, implications for myocardial MR diffusion tensor imaging are largely unknown. In this study, a slow-exchange-limit, two-component diffusion tensor model was fitted to diffusion-weighted images obtained in isolated, perfused rat hearts. Results indicate that there are at least two distinct components of anisotropic diffusion, characterized by a "fast" component whose principal diffusivity is comparable to that of the perfusate, and a highly anisotropic "slow" component. It is speculated that the two components correspond to tissue compartments and have a general agreement with the orientations of anisotropy, or fiber orientations, in the myocardium. Moreover, consideration of previous studies of myocardial diffusion suggests that the presently observed fast component may likely be dominated by diffusion in the vascular space, whereas the slow component may include the intracellular and interstitial compartments. The implications of the results for myocardial fiber orientation mapping and limitations of the current two-component model used are also discussed. Magn Reson Med 45:1039,1045, 2001. © 2001 Wiley-Liss, Inc. [source] Stereological comparison of 3D spatial relationships involving villi and intervillous pores in human placentas from control and diabetic pregnanciesJOURNAL OF ANATOMY, Issue 2 2000TERRY M. MAYHEW In human placenta, 3D spatial relationships between villi and the maternal vascular bed determine intervillous porosity and this, in turn, influences haemodynamics and transport. Recently-developed stereological methods were applied in order to examine and quantify these relationships. Placentas were collected after 37 wk from control pregnancies and those associated with maternal diabetes mellitus classified according to duration and severity (White classification scheme). Two principal questions were addressed: (1) are normal spatial arrangements maintained in well-controlled diabetes mellitus? and (2) do arrangements vary between diabetic groups? To answer these questions, tissue sections cut at random positions and orientations were generated by systematic sampling procedures. Volume densities of villi (terminal+intermediate), intervillous spaces and perivillous fibrin-type fibrinoid deposits were estimated by test point counting and converted to global volumes after multiplying by placental volumes. Design-based estimates of the sizes (volume- and surface-weighted volumes) of intervillous ,pores' were obtained by measuring the lengths of point- and intersection-sampled intercepts. From these, theoretical numbers of pores were calculated. Model-based estimates (cylinder model) of the hydraulic diameters and lengths of pores were also made. Second-order stereology was used to examine spatial relationships within and between villi and pores and to test whether pair correlation functions deviated from the value expected for ,random' arrangements. Estimated quantities did not differ significantly between diabetic groups but did display some departures from control values in non-insulin-dependent (type 2) diabetic placentas. These findings support earlier studies which indicate that essentially normal microscopical morphology is preserved in placentas from diabetic subjects with good glycaemic control. Therefore, it is likely that fetal hypoxia associated with maternal diabetes mellitus is due to metabolic disturbances rather than abnormalities in the quantities or arrangements of maternal vascular spaces. [source] Congenital myofibroma of the skin mimicking a piloleiomyomaJOURNAL OF CUTANEOUS PATHOLOGY, Issue 6 2010Takuya Inoue Myofibroma is an uncommon benign soft tissue disorder, which is usually congenital or present in early infancy. Myofibroma usually manifests as a single mass. When there are multiple lesions, the term myofibromatosis is used. The characteristic histopathological feature of the myofibroma is the coexistence of two distinct areas. One area mainly contains plump spindle cells with thin blunt-ended nuclei and eosinophilic cytoplasm, thus indicating myoid characteristics. The other area contains either round or polygonal cells with slightly pleomorphic, hyperchromatic nuclei or small spindle cells typically arranged around a distinct hemangiopericytoma-like vascular pattern. In the present case, the majority of the tumor was composed of the plump myoid spindle cells. This led to an initial diagnosis of a piloleiomyoma. However, the tumor cells were not immunohistochemically positive for desmin. Moreover, careful examination revealed a hemangiopericytoma-like vascular pattern characterized by the presence of high cellular areas with irregular vascular spaces. These features led to the final diagnosis of the myofibroma. It is therefore important to recognize the leiomyoma-like variants of myofibromas. Inoue T, Sada A, Mori T, Misago N, Narisawa Y. Congenital myofibroma of the skin mimicking a piloleiomyoma. [source] Multiple mucinous and lipomatous variant of eccrine angiomatous hamartoma associated with spindle cell hemangioma: a novel collision tumor?JOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2006Hae-Woong Lee In most cases, EAH arises as a single lesion; however, multiple variants have been reported. We report a 35-year-old female patient with multiple, sudoriparous, subcutaneous nodules on the right foot, which showed typical histopathological findings of EAH, and vascular components of the tumor consisted of thin-walled dilated vascular spaces intermixed with spindle cells and some histiocytoid endothelial cells representing spindle cell hemangioma (SCH). To our knowledge, the co-existence of EAH with SCH is a novel finding and not yet described. [source] Hobnail hemangiomas (targetoid hemosiderotic hemangiomas) are true lymphangiomasJOURNAL OF CUTANEOUS PATHOLOGY, Issue 5 2004Folker E. Franke Background:, Hobnail hemangioma (targetoid hemosiderotic hemangioma) is a small benign vascular tumor of the superficial and mid-dermis. In contrast to its well-characterized histology, it has been unclear whether this tumor arises from blood vessel endothelial cells (BECs) or lymphatic vessel endothelial cells (LECs). Methods:, We analyzed 10 hobnail hemangiomas by immunohistochemistry, using the recently described lymphatic endothelial cell marker, D2-40. For comparison, CD31, CD34, and ,-smooth muscle actin expression were studied in consecutive sections of the paraffin-embedded tissues. Results:, In all analyzed vessels, D2-40 labeled exclusively LECs, whereas BECs were consistently negative. In contrast to capillary BECs, either neighboring the tumors or intermingled, neoplastic endothelial cells of all 10 hobnail hemangiomas were strongly labeled by D2-40. Conclusions:, The results suggest a lymphatic origin for hobnail hemangiomas. This view is further supported by the CD34 negativity of endothelial cells and the lack of actin-labeled pericytes in hobnail hemangiomas, both characteristic of lymphatic vessels. Moreover, our analysis revealed that microshunts between neoplastic lymphatic vascular channels and small blood vessels occur, explaining some features of hobnail hemangiomas, such as aneurysmatic microstructures, erythrocytes within and beneath neoplastic vascular spaces, inflammatory changes, scarring, and interstitial hemosiderin deposits. [source] Dental root resorption and repair: histology and histometry during physiological drift of rat molarsJOURNAL OF PERIODONTAL RESEARCH, Issue 5 2003Ryusei Kimura Objective:, The process of dental root resorption and subsequent cementum regeneration has not been sufficiently elucidated. This study aimed to examine the process of the root resorption and cementum regeneration during physiological tooth drift using a rat model, and to evaluate this experimental model. Methods:, Distal roots in mandibular first molars and the surrounding periodontal tissues were investigated with light and electron microscopy. The light microscopic approach included histochemical and histometric analyses utilizing the tartrate-resistant acid phosphatase (TRAP) reaction. Results:, Root resorption was observed in the distal side of the roots and was most active in 5- to 6-week-old rats, and gradually decreased hereafter. An increase in the number of TRAP-positive mononuclear cells, which seemed to be odontoclast precursor cells, preceded the increase in the number of odontoclasts. Root resorption was transient, and was followed by the new formation of acellular extrinsic fiber cementum accompanied with only a slight inflammation, and therefore classified as external surface resorption. Preparation for new cementum started adjacent to the resorption areas when root resorption was most active. Conclusions:, The root resorption during drift in rats is transient and followed by acellular extrinsic fiber cementum regeneration. Cellular kinetics suggested that odontoclast precursor cells are supplied as mononuclear cells from vascular spaces. [source] Pseudoangiomatous Stromal Hyperplasia: Presentation as a Mass in the Female NippleTHE BREAST JOURNAL, Issue 4 2001Dan Iancu MD Abstract: Pseudoangiomatous stromal hyperplasia (PASH) is a benign, localized fibroblastic and myofibroblastic overgrowth that occurs almost exclusively in premenopausal women as a painless, palpable intramammary mass. The lesion has a pale, fibrous, and homogeneous cut surface, is typically well circumscribed, and may have a diameter of 2.0,15 cm. Its ramifying slits lined by flattened myofibroblastic cells are apt to be mistaken for vascular spaces, leading to an erroneous diagnosis of angiosarcoma. The etiology of the condition is unknown, but a relationship to myofibroblastoma has been postulated. Hormonal factors, too, are thought to play a developmental role. The potential for PASH to create a palpable breast mass has been only quite recently advanced in the medical literature, and it has evidently not been reported in the nipple. [source] Does Erectile Tissue Angioarchitecture Modify with Aging?THE JOURNAL OF SEXUAL MEDICINE, Issue 4 2008An Immunohistological, Morphometric Approach ABSTRACT Introduction., Erectile dysfunction is a common problem in aged men; however, which vascular cavernosal alterations occur with age progression remain unclarified. Aim., Using cavernosal tissue from rats of various ages, we aimed to thoroughly assess erectile vascular-associated morphologic, immunohistological, and morphometric alterations during aging. Methods., Male Wistar rats were divided according to age in groups of 2, 6, 12, 18, 24 months old (N = 5). Cavernosal tissue of all groups was collected and processed for morphologic evaluation, immunodetection of ,-smooth muscle actin and von Willebrand factor and morphometric quantification of vascular and smooth muscle cell (SMC) areas. Main Outcome Measures., The morphometric assessment of age-related alterations in cavernosal vascular and SMCs using the ImageJ image-processing program. Results., Morphologic and immunohistological evaluation showed a similar structure of erectile tissue among all age groups, divided in two cavernosal bodies containing numerous sinusoidal vascular spaces surrounded by SMCs. Additionally, we observed a reduction of SMC content and an increase in the caliber of vascular spaces, with aging. This was confirmed by the morphometric quantification of the vascular and SMC areas (mean area ×103 µm2 ± ×103 standard error). Two-month-old animals had a mean vascular area of 4.21 ± 0.51, approximately 3.5-fold less than the 6-month-old group. The differences increased when comparing the youngest groups with the 12-, 18-, and 24-month-old animals, with mean measurements of 18.99 ± 1.91, 25.23 ± 2.76, and 26.34 ± 2.97. Conversely, SMC areas progressively decreased between 2- and 6-month-old animals, from 6.75 ± 0.90 to 6.38 ± 1.24. The elderly 12-, 18-, and 24-month-old groups presented an approximated 1.5-fold reduction on SMCs area, showed by the respective measurements of 4.11 ± 0.50, 4.01 ± 0.35, and 4.02 ± 0.44. Conclusions., We demonstrated that cavernosal angioarchitecture was modified with aging. The decrease in SMCs and the considerable enlargement of vascular lumens may limit the basic function of penile vascular tree in the elderly. Costa C, and Vendeira P. Does erectile tissue angioarchitecture modify with aging? An immunohistological and morphometric approach. J Sex Med 2008;5:833,840. [source] Quantification of Angiogenesis in Otosclerosis,THE LARYNGOSCOPE, Issue 5 2005Robert W. Jyung MD Abstract Objectives/Hypothesis: The determinants of clinical versus histologic otosclerosis are unknown, but angiogenesis is associated with active disease. We hypothesized that quantification of angiogenesis in otosclerotic human temporal bones could reveal significant differences between clinical and histologic cases. Study Design: We reviewed all otosclerosis specimens meeting criteria from the temporal bone collection of the Massachusetts Eye and Ear Infirmary and 10 normal controls. Methods: Digital images were taken at predilection sites, followed by computer-assisted analysis. Canalicular area (CA), the aggregate of vascular spaces within bone, microvessel density (MVD), area, and depth were the main measures. Evidence of a direct connection between local vessels and the vasculature of the otosclerotic focus was also recorded for each specimen. Results: The average area (mm2) and depth (number of sections containing otosclerosis) of clinical lesions was significantly greater than histologic lesions. Total microvessel counts were significantly greater in clinical versus histologic lesions, and both clinical and histologic lesions contained significantly greater numbers of microvessels than the normal otic capsule. CA was also significantly higher in clinical lesions. MVD was slightly but not significantly higher in clinical lesions. Importantly, a direct connection between named vessels and the otosclerotic vasculature was significantly more frequent in clinical lesions. Conclusions: Computer-assisted quantification revealed significantly greater measures of angiogenesis in clinical versus histologic otosclerosis. Direct connection to adjacent vessels may support angiogenesis in this disease. Sustained angiogenesis may be an important determinant of clinical otosclerosis. [source] First Evidence of Genetic Imbalances in AngiofibromasTHE LARYNGOSCOPE, Issue 2 2002Bernhard Schick MD Abstract Objective/Hypothesis Angiofibromas are clinically well characterized by their origin at the posterior lateral nasal wall close to the sphenopalatine foramen, their occurrence in male adolescent patients, and the histological findings of a benign fibrovascular neoplasm with irregular, endothelium-lined vascular spaces in a fibrous stroma. However, their etiology and genetic causes remain unknown. The present study addresses genetic imbalances in angiofibromas. Study Design The present pilot study compared genomic hybridization in three angiofibromas to search for chromosomal abnormalities in this rare tumor. Methods Fluorescence-marked normal DNA and angiofibroma DNA were compared using genomic hybridization screening to detect chromosomal abnormalities. Their binding ratio to metaphase chromosomes were analyzed by special digital image analysis. Results Chromosomal gains and losses showing a high level of agreement were detected in all three angiofibromas. Specifically, DNA gains were observed on chromosomes 3q, 4q, 5q, 6q, 7q, 8q, 12p, 12q, 13q, 14q, 18q, 21q, and X, and DNA losses were screened on chromosomes 17, 19p, 22q, and Y. Finding chromosomal abnormalities at the sex chromosomes X and Y of this rare tumor is remarkable. Concurrent chromosomal gain on 8q12q22 was noted in all three tumor specimens. Conclusions Comparative genomic hybridization is suitable for screening angiofibromas on a genetic level. The results on these screens indicate that further genetic investigations of this rare benign tumor may provide more details about the tumor's genetic abnormalities and perhaps clarify the etiology of angiofibromas. [source] Effect of mesenchymal stem cell penile transplantation on erectile signaling of aged ratsANDROLOGIA, Issue 3 2010M. T. Abdel Aziz Summary Stem cell-based therapy targeted at the penile tissue has been lately considered in preclinical studies. This work aimed to assess the effect of intracavernous administration of mesenchymal stem cells (MSCs) in aged rats (n = 100). They were subjected to single intracavernous injection (ICI) of 1.0 million MSCs, followed up for 3, 4 weeks, 3 and 4 months (each group 25 rats) and compared with both adult and aged controls (n = 50). In dissected cavernous tissues, cGMP and histopathology were assessed in addition to intracavernous pressure (ICP) measurement in some anaesthetised rats. The results showed that cavernous tissue cGMP was significantly increased in MSCs transplanted rats in all investigated groups compared with the controls. The mean cavernous cGMP levels after 3 and 4 months of MSCs transplantation were significantly increased compared with those after 3 or 4 weeks. Cavernous tissue ICP measurement showed significant increase in MSCs transplanted groups compared with the controls, more in the long-term follow up than in the shorter one. Histopathological examination detected markedly dilated sinusoidal vascular spaces in the long-term follow-up study. It is concluded that stem cell-based therapy is feasible for age-associated erectile dysfunction and could improve erectile signaling. [source] In vitro viability of human cavernosal endothelial and fibroblastic cells after exposure to papaverine/phentolamine and prostaglandin E1BJU INTERNATIONAL, Issue 9 2005Adrian Pilatz OBJECTIVE To investigate the influence of commercially available vasoactive drugs on human cavernosal endothelial and fibroblastic cells in vitro, as although corporal fibrosis is a well known side-effect of intracavernosal injection therapy for erectile dysfunction, the possible detrimental effect of these agents on the endothelium lining the cavernosal vascular spaces is uncertain. MATERIALS AND METHODS Cultured primary endothelial (13) and fibroblastic cells (12), obtained from potent patients undergoing penile surgery, were exposed to different physiological dilutions of prostaglandin E1 (PGE1), papaverine/phentolamine or the respective triple-mix of these agents for 30 min. Viable cells were counted and cell metabolic activity measured in these cultures 48 h after drug exposure. RESULTS There was a significant dose-dependent decrease in the viable cell count after exposure to papaverine-containing formulations, probably because of the low pH of this substance. This cytotoxic effect was more pronounced in endothelial than in fibroblastic cells, and was not apparent in the PGE1 groups. The relative increase in cell metabolic activity in cultures affected by a moderate cytotoxic effect indicated a regenerative process. CONCLUSION These comparative results in endothelial and fibroblastic cell cultures suggest that the endothelium rather than the interstitium of the corpus cavernosum is more sensitive to side-effects produced by intracavernosal injection therapy with papaverine. Thus, unfavourable consequences on the function of the endothelial layer might be as important as the risk of interstitial fibrosis. As these effects were not detected for PGE1 this drug should be preferred to papaverine in clinical practice. [source] | ||||||||||