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PubMed2006

Cotyledonoid dissecting leiomyoma of the uterus: a case report of a benign uterine tumor with sarcomalike gross appearance and review of literature.

Cotyledonoid dissecting leiomyoma (Sternberg tumor) is a very rare variant of uterine smooth muscle tumor with an unusual and alarming gross appearance. Including our case, approximately 20 cases were reported in the literature. A 27-year-old woman presented with pelvic mass. A 41-cm fungating rubbery mass with placenta-like appearance adhering to the posterior uterine surface and extending to the left broad ligament and pelvic cavity was observed. An intraoperative frozen section was requested, and a diagnosis of a benign smooth muscle tumor was given. Total abdominal hysterectomy and bilateral salpingo-oophorectomy were performed with removal of the pelvic tumor extension. Thorough tumor sampling was performed and showed nodules of interlacing bundles of bland-looking smooth muscle cells, separated by expanded, edematous, and highly vascularized stroma. No atypia, mitotic activity, or coagulative necrosis was seen. Immunohistochemical studies confirmed the smooth muscle nature of the tumor. Cotyledonoid leiomyoma has a distinctive gross appearance which usually raises the suspicion of sarcoma. Intraoperative frozen section is a mandatory and helpful procedure to avoid overtreatment of such cases.

Actins↗
PubMed2006

Immunohistochemical localization of distinct angiotensin II AT1 receptor isoforms in the kidneys of the Sprague-Dawley rat and the desert rodent Meriones crassus.

Employing a purified lgG fraction of a polyclonal anti-AT1 receptor anti-body, raised against a synthetic octapeptide encompassing residues 14-21 of the first extracellular domain of the AT1 polypeptide, selective AT1 receptor expression was immunohistochemically demonstrable within renal structures in Sprague-Dawley (SD) rats and the desert rodent Meriones crassus. In both animal models, prominent AT1 receptor labelling was evident in renal vascular elements, particularly cortical inter-lobular arteries (IA) as well as vasa recta bundles in the inner stripe of the outer medulla. Less intense labelling was observed among peritubular capillary endothelia within the deep cortex, and at both the outer stripe and the inter-bundle regions of the inner stripe of the outer medulla. The binding of the anti-peptide anti-body was, however, lacking among glomeruli and, except for the intense labelling confined to basement membranes of Bowman's capsule of deep nephrons, was virtually absent in all renal tubular structures of both animal models. Structural assessment of the expressed AT1 receptors by two-dimensional Western blotting revealed that a spectrum of structurally distinct AT1 receptor isoforms is expressed in the renal tissues of both animal models. This spectrum was constituted by isoforms of equal size (70 kDa) but distinct pls in SD rats, and of both different sizes (67-73 kDa) and isoelectric points in M. crassus. In either species, the charge and/or size heterogeneity of AT1 receptor isoforms may be attributed in part to differential post-translational glycosylation mechanisms of the AT1 receptor polypeptide backbone. The potential for the differential glycosylation state of AT1 receptors to alter recognition properties may add another level of complexity to tissue-specific and/or species-specific mechanisms underlying angiotensin II interactions in the kidney.

Animals↗
PubMed2001

Solitary fibrous tumour of the urinary bladder with expression of bcl-2, CD34, and insulin-like growth factor type II.

We describe a solitary fibrous tumour of the urinary bladder wall removed from a 50-year-old man with a history of pelvic pain, dysuria, and urinary bleeding. Anamnesis revealed a weight increase during the preceding 3 months, but no apparent episodes of biochemical hypoglycaemia or hormonal abnormalities. The patient is alive and well 18 months after surgery. Pathological examination revealed a 6.5-cm well-circumscribed nodular mass composed of uniform spindle cells arranged in bundles and fascicles with varying amounts of collagen and a typical haemangiopericytoma-like vascular pattern. The tumour cells were positive for bcl-2, CD34, and vimentin and ultrastructurally showed mesenchymal-myofibroblastic traits. These cells produced insulin-like growth factor type II mRNA as demonstrated by non-isotopic in situ hybridization. This rare case with a solitary fibrous tumor suggests that insulin-like growth factor type II could join CD34 and bcl-2 as markers for postoperative differential diagnosis.

Antigens, CD34↗
PubMed2006

Considerations on the sinus node microangioarchitecture.

The importance of the sinus node as the cardiac pacemaker is well known. The aim of the present study was to investigate the microangioarchitecture at the level of the sinus node. Ten human adult hearts were injected with India ink in the initial segments of the coronary arteries. Pieces were drawn and diaphanized. The results of the study can be summarized: (1) the sinus node is rather an irregularly shaped structure, with peripheral strands intermingling with strands of the atrial myocardium; at this level two vascular patterns can be recognized: (a) the myocardial capillary networks that parallels the muscular bundles, and (b) the peripheral nodal networks built upon dichotomizing arterioles; (2) it seems that while the thick and large sinus node artery does not branch in the nodal tissue, the blood supply of this tissue is ensured by the peripheral nodal networks; (3) characteristically, in the periphery of the nodal tissue are largely present glomeruli made by capillaries with pericellular dispositions. The results strongly suggest that the nodal tissue is mainly supplied from its periphery and the sinus node artery is rather a scaffold than a supplier of that tissue.

Carbon↗
PubMedDate not supplied

Computed tomography of orthopedic tumors of the pelvis and lower extremities.

An analysis of 6 representative cases of tumors of the pelvis and lower extremities demonstrates the clinical usefulness of computerized tomography (CT) in preoperative evaluation. CT provides information regarding precise size of the mass, its location and relationship to muscle bundles and fascial planes, definition of the margins of the mass, relation to neural, vascular and bony structures not previously available by plain film and angiography. This information is of particular value to the orthopedic surgeon in evaluating the feasibility of en bloc resections of tumors and in planning reconstructive procedures.

Adolescent↗
PubMed1985

Vaginal hemangiopericytoma: a light microscopic and ultrastructural study.

A case of a vaginal hemangiopericytoma in a 20-year-old woman was studied by light and electron microscopy. The neoplastic cells had round-to-oval nuclei with one or two nucleoli; fine chromatin; a foamy, cyanophilic cytoplasm; and an increased nuclear cytoplasmic ratio. Light microscopically, the tumor was composed of spindle-shaped or round cells proliferating around vascular spaces. Mitotic figures, necrosis, and hemorrhage were difficult to find. Electron microscopically, the neoplastic cells occurred in clusters, each of which was enclosed by a basal lamina. The cytoplasm contained abundant free ribosomes, flattened elements of rough endoplasmic reticulum, small Golgi apparatus, round or elongated mitochondria, lysosomes, glycogen particles, and sometimes pinocytotic vesicles and bundles of microfilaments with large dense spots. Desmosomes were also seen. In addition, the cytoplasmic process of the benign vascular pericytes was directly in contact with the neoplastic cells which had varying degrees of cytodifferentiation. The neoplastic cells in this lesion are consistent with an origin from pericytes, confirming the findings of this neoplasm when it arose in other sites.

Adult↗
PubMed2003

[Experimental study on preparing chitosan-collagen matrix and subcutaneous implantation].

OBJECTIVE: To investigate the feasibility of the chitosan-collagen membrane (CCM) as a dermal substitute. METHODS: Fresh bovine tendo calcaneus collagen was dispersed in 0.5 mol/L acetic acid, co-precipitated with chitosan and lyophilized. Dry membranes were cross-linked in 0.05% glutaraldehyde for 24 hours. In vitro its degrading rate was measured by use of collagenase degrading test. The chitosan-collagen membrane was implanted to subcutaneous dorsal sites of SD rats. After implantation, histocompatibility, vascularity and degradation were observed in vivo. RESULTS: The chitosan-collagen membrane was yellowish, translucent, and porous. Pore size ranged 50-250 microns, and collagen fiber bundles were reticular arrangement in the membrane. It had slower degradation than pure collagen membrane by collagenase in vitro. Subcutaneous implantation test showed the minimal inflammation, good histocompatibility and earlier vascularization. The membrane degradation was slower in vivo. Eight weeks after implantation, organized collagen structure was retained. CONCLUSION: The chitosan-collagen membrane has better physical and biological properties, ideal histocompatibility, earlier vascularization and slower degradation. Therefore, It is an optimum substitute for dermal scaffold.

Animals↗
PubMed2005

Cyclic adenosine monophosphate and cyclic guanosine monophosphate-phosphodiesterase isoenzymes in human vagina: relation to nitric oxide synthase isoforms and vasoactive intestinal polypeptide-containing nerves.

OBJECTIVES: To evaluate the distribution of cyclic guanosine monophosphate (cGMP) and cyclic adenosine monophosphate (cAMP) phosphodiesterases (PDEs) in relation to nitric oxide synthase isoforms and vasoactive intestinal polypeptide (VIP) in specimens of the human vagina. Nitric oxide and VIP, mediating biologic signals through cGMP and cAMP, have been assumed to be involved in the control of vaginal smooth muscle. METHODS: Immunohistochemical techniques were applied to sectioned specimens of the human vaginal wall to evaluate the presence of the PDE isoenzymes 3, 4, 5, and 10 in relation to neuronal nitric oxide synthase (nNOS), endothelial NOS (eNOS), and VIP. RESULTS: Immunoreactivity (IR) for cAMP-degrading PDE-4 was observed in the vaginal nonvascular smooth musculature, as well as in the wall of subepithelial arteries. VIP-IR nerves innervated the smooth muscle portion of the vaginal wall and also formed a subepithelial network. Immunoreactivity specific for PDE-5 was also registered in vascular and nonvascular vaginal smooth muscle. Immunosignals for eNOS were detected in the endothelial lining of arteries containing PDE-5-IR smooth muscle cells. These arteries were supplied by nNOS-IR nerve fibers. PDE-10-IR smooth muscle cells were located in muscle bundles of the vaginal wall. CONCLUSIONS: Our study revealed immunoreactivity specific for PDE-4, PDE-5, and PDE-10 in the vascular and nonvascular smooth muscle of the vagina. Immunosignals for PDE-4 and PDE-5 were also observed in close proximity to nNOS-IR or VIP-IR nerve fibers or to eNOS-IR endothelial cells. The distribution of PDEs may indicate a role of these enzymes in the control of the function of the human vagina.

Adolescent↗
PubMed1977

The ultrastructure of granuloma annulare.

Nine cases of granuloma annulare at different stages of development were investigated electron microscopically. Special attention was given to collagen changes, to the cellular infiltrate, and to vascular changes. The necrobiotic changes of the collagen were: loosening of the fibers at the borders of the bundles; swelling and loss of cross-striation of the fibrils; and complete degradation of the collagen, with precipitation of mucinous and fibrin material and of glycogen. In 2 cases "cross-banded filamentous aggregations" were present. In later stages new collagen synthesis occurred. In the infiltrate, histiocytes/macrophages were seen developing into epithelioid and giant cells. In addition, numerous active lymphocytes and, at later stages, some neutrophils were found. Vascular changes consisted of endothelial swelling and duplications of the basal lamina. A perivascular infiltrate was present, but no distinct vasculitis was seen. Our results indicate that the necrobiosis of the collagen without primary vasculitis may be an initial event in granuloma annulare. A delayed hypersensitivity mechanism is discussed with regard to pathogenesis.

Adult↗
PubMed1991

Techniques of peripheral nerve repair.

At present, the principles of microsurgical reconstruction of the peripheral nerve incorporate a clear understanding of the pathophysiology of the peripheral nerve, accurate preoperative assessment of the lesion, aggressive early treatment to avoid irreversible atrophy of the end organ, use of nontraumatic microtechniques for optimal alignment of individual fascicular bundles, introduction of a minimum amount of foreign material at the suture line, resection of the scar-producing epineurium, total avoidance of tension at the suture line, and placement of the nerve repair in a well-vascularized soft tissue bed. If tension is eliminated, a minimal amount of suture material is required to repair the nerve ends, because the bundles are maintained in anatomical alignment by a fibrin clot. We have reviewed the various nerve repair methods, stressing that with strict attention to microsurgical technique, the surgeon can hope to maximize reinnervation. Although the importance of all aspects of careful surgical technique cannot be overemphasized, we believe that it is unlikely that improved clinical results will come from further refinements in microsurgical techniques. We are not limited by a working knowledge and understanding of the details of the neurobiology and the neurochemistry of nerve regeneration.

Humans↗
PubMed1986

Orbital-adnexal lymphangiomas. A spectrum of hemodynamically isolated vascular hamartomas.

A retrospective review of 13 cases of lymphangioma has led to a classification of these lesions into categories of superficial, deep, and combined types. The clinical manifestations, prognosis, and management directly correlate with the pathophysiology and the location of the lesions. Superficial lesions consist of isolated multicystic vascular abnormalities of cosmetic significance only. Deep orbital lymphangiomas present as spontaneous, acute proptosis due to retrobulbar hemorrhage. Combined lesions demonstrate both superficial and deep components and are also characterized by spontaneous hemorrhages. Histopathologically, lymphangiomas represent a spectrum of vascular hamartomas with a constellation of features that parallels the clinical progression and histology of similar lesions elsewhere in the head and neck. This may include the presence of diaphanous serous-filled vascular channels, a connective tissue stroma with lymphorrhages, features of old hemorrhage, dysplastic vessels, and random smooth muscle bundles. Both direct and indirect evidence suggests that these lesions are characterized by relative hemodynamic isolation.

Adult↗
PubMed2004

Photodynamic-induced vascular damage of the chick chorioallantoic membrane model using perylenequinones.

The chorioallantoic membrane (CAM) assay is a widely used bioassay in early in vivo cancer research. The CAM allows non-invasive study of in vivo microvasculature and blood circulation. This report describes the first topical application investigation of photodynamic response in the CAM model using Hypericin (HY) and Hypocrellin B (HB) that belongs to the perylenequinone family. Briefly, cultivated carcinoma of the human bladder cell line (MGH), were inoculated on the CAM of fertilized eggs of embryo age (EA) 9. Tumor growth was evaluated by digital stereomicroscopy. Photodynamic therapy (PDT) was performed following topical application of the photosensitizers. We were able to demonstrate that these perylenequinones localized selectively in the xenografted bladder tumor and in the vasculature of the CAM. Photodynamic treatments were performed using a custom-made non-laser light source coupled into a flexible fiber bundle to selectively excite the photosensitizers in order to induce photodamage to the tumor and vasculature. The vascular damage induced was quantitatively measured following topical application of the photosensitizers. Both photosensitizers exhibited very similar degrees of photodamage to the CAM. The CAM model offers an exciting avenue for the study of PDT induced effect on the vasculature. Our preliminary results support that the CAM model could potentially serve as a customized model to study photodynamic therapy effects of various photosensitizers on specific tumor models.

Animals↗
PubMed1996

Ligand activation of ELK receptor tyrosine kinase promotes its association with Grb10 and Grb2 in vascular endothelial cells.

ELK is a member of the Eph-related tyrosine kinase family that includes receptors signaling axonal guidance, neuronal bundling, and angiogenesis. We recently identified ELK expression in human renal microvascular endothelial cells and sought to identify intracellular proteins through which it signals responses. The cytoplasmic domain of ELK was used as "bait" in a yeast two-hybrid screen to identify interactive proteins expressed from a randomly primed embryonic murine library (E9.5-10.5). Among interactive products of 76 cDNAs characterized, 10 nonidentical, overlapping clones encoded the SH2 domain of the recently reported Grb10 adapter protein, and an additional 3 encoded Grb2. A self-phosphorylated recombinant, baculovirus-expressed GST-ELKcy fusion protein bound Grb10 and Grb2 from human renal microvascular endothelial cell extracts, while the unphosphorylated fusion form did not. Site-directed mutation identified Tyr-929 as a putative phosphorylation site required for Grb10, but not Grb2, interaction in yeast and recombinant protein assays. The ELK ligand, LERK-2/Fc, stimulated tyrosine phosphorylation of ELK, and recruitment of Grb10 and Grb2 to endothelial ELK receptors recovered by wheat germ agglutinin lectin and immunoprecipitation. These findings define ligand-activated interaction between ELK and the SH2 domains of Grb2 and the newly identified Grb10 protein that shares homology with a Caenorhabditis elegans gene product implicated in neural cell migration.

Adaptor Proteins, Signal Transducing↗
PubMed1994

Functional anatomy of the retro- and suprahepatic portions of the human inferior vena cava and their main affluents.

The arrangement of muscle, collagen and elastic fibers was studied in the retro- and suprahepatic (subdiaphragmatic) portions of the inferior vena cava, the hepatic veins and their main affluents. Distinctive features of the longitudinal and transverse muscle bundles are described. In these portions of the vena cava, both bundle systems are clearly separate and any continuity was observed only at the entrances of the hepatic veins. A musculo-venulolymphatic complex was noted in spurs formed by the vascular junctions. The hepatic veins and their main affluents exhibit an elliptical contour in transverse section, which apparently results from cranial and caudal thickenings of the longitudinal muscle layer. Many of these bundles are in continuity with those of the transverse muscle layer. Terminal elastic tendons were rarely observed in connection with muscle fibers of the inferior vena cava and are not present in the hepatic veins and their main affluents. In terms of form and function, the relatively thin muscular layer has a dilating action on the hepatic venous system because of the external fixed insertion point of the muscle bundles. Such an arrangement and a "polar" disposition of the muscle bundles in the hepatic venous system may assists in "suction" of the blood toward the heart. A sphincteric control of the ostia by means of crossed muscular loops supported by venulo-lymphatic micropads is a possibility.

Collagen↗
PubMed1979

Concomitant arteriovenous vascular malformation in skeletal muscle: a clinical, angiographic and histologic study.

A vascular malformation in skeletal muscle is described in 4 patients. Pathologically and anatomically, it consists of an abundance of concomitant arteries and veins and thick-walled capillaries. Angiography demonstrates the high vascularity of the lesion, and contrast medium appears early in draining veins indicating arteriovenous shunting. In the angiograms, the highly vascular region displays a certain striation which is due to the presence of muscle fiber bundles running between the pathologic vessels. This angiographic picture suggests benignity: an intramuscular malignant tumor rarely leaves intact muscle fiber bundles passing right through it.

Adult↗
PubMed1991

Pigment cell localizations in anuran ventral skin at climactic metamorphosis.

In anuran amphibians, the specific color pattern of the skin is expressed after metamorphosis, and its formation involves pigment cell migrations. Pigment cells are differently distributed in the tadpole, larval, and froglet skin. To learn more about their fate during metamorphic climax and in the young froglet, we focused our attention on the different localizations of larval melanophores and iridophores in the ventral skin of Rana esculenta before and during skin homing. Localizations of melanophores and iridophores can be elucidated at the developmental stages suggested by Taylor and Kollros (TK stages). At TK stage II (during early premetamorphosis), large melanophores beneath the larval skin are detected. At TK stage X, dispersed melanophores lie under bundles of muscular striated fibrils near the larval skin; they are also observed at the vascular level. At TK stage XVII (prometamorphosis), melanophores are extended on the inner side of the basement lamellar collagen. At the end of prometamorphosis, iridophores are located with melanophores in the separating space between attached basement collagen and derived basement collagen. At TK stage XX (earlier climax), melanophores and iridophores are detected inside the upper extremities of fractures opened in the derived basement collagen. At TK stage XXIV (later climax), both types of larval pigment cells are observed in the inner extremities of breaks derived from the fractures. During climax, these pigment cells occupy the well-formed breaks. At TK stage XXV in young froglet, the pigment cells remain alone in the breaks formed in the derived basement collagen. Briefly, breaks in the basement lamellar collagen are opened by invading cell processes of mesenchymal cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Factors influencing myofibroblast differentiation during wound healing and fibrosis.

Granulation tissue fibroblasts (myofibroblasts) develop several ultrastructural and biochemical features of smooth muscle (SM) cells, including the presence of microfilaments bundles and the expression of alpha-SM actin, the actin isoform typical of contractile vascular SM cells. Myofibroblasts have been suggested to play a role in wound contraction and in retractile phenomena observed during fibrotic diseases. When granulation tissue evolves into a scar, myofibroblasts containing alpha-SM actin disappear, probably as a result of apoptosis. In contrast myofibroblasts expressing alpha-Sm actin persist in excessive scarring and in fibrotic conditions. The mechanisms leading to the development of myofibroblastic features remain to be investigated. Studies on the factors regulating the phenotype of myofibroblasts will be necessary for understanding their behavior in vivo, and possibly modifying this behavior during the different clinical settings.

Animals↗
PubMed2001

Light and electron microscopic study of stress-shielding effects on rat patellar tendon.

In this second part of our study, the histomorphologic changes occurring in the patellar tendon (PT) of rats after sole stress-shielding were evaluated. In seven adult albino rats, both PTs were exposed by straight skin incision and then stress-shielded on one side by a cerclage, while the contralateral PT served as the sham-operated control. One animal died after the operation and was used as a negative control. After 10 weeks of otherwise unrestricted motion, the rats were killed, and the histomorphology of all PT specimen pairs compared by light and transmission electron microscopy. Light microscopy showed mid-portion thickening and irregularity of collagen bundles in the stress-shielded tendons. Intense remodelling was demonstrated by increased cellularity and vascularity, as well as by enrichment in acidic proteoglycans. Ultrastructural evaluation and morphometry revealed a predominance of large diameter (peak between 180 and 260 nm) collagen fibrils in the sham-operated controls, while in the stress-shielded tendons the number of apparently new, small-diameter (peak between 40 and 60 nm) collagen fibrils increased (up to 77% per cross-sectional field of view). The difference in peak diameters was statistically significant (p < 0.0005). This rat model demonstrated that sole stress-shielding not only causes biomechanical alterations, but also intense tissue remodelling and significant morphological changes in the collagen fibrils in the patellar tendon, comparable to so-called 'ligamentization' in experimental and clinical patellar tendon grafts for anterior cruciate ligament reconstruction.

Animals↗