Search results for "ICYT"

Ultrastructure of vascular neoplasms

1982

Summary The vascular tumors are morphologically recognized by their ability to configurate complete or atypical angiomatous structures. Based on our personal experience of 42 cases of benign and malignant angiomatous tumors, we discussed several aspects of their histogenesis and its morphology when studied with transmission and scanning electron microscopy. Therefore, a survey of the normal histology was developed based not only on normal adult histological structures but also on reparative tissues, as in chronic inflammatory reactions of the gingival mucosa, regenerative tissue of wounds and in chronic osteomyelitis. Supported by morphological arguments, we postulate the existence of sever…

Extracranial metastasizing solitary fibrous tumors (SFT) of meninges: Histopathological features of a case with long-term follow-up

2012

Extrapleural solitary fibrous tumors are uncommon mesenchymal neoplasms frequently observed in middle-aged adults and are classified, according to the WHO classification of soft tissue tumors, as part of the hemangiopericytoma tumor group. However, these two entities remain separated in the WHO classification of tumors of the central nervous system. In fact, meningeal solitary fibrous tumors are believed to be benign lesion and only in a minority of cases local relapses have been described, although detailed survival clinical studies on solitary fibrous tumors of meninges are rare. In contrast to hemangiopericytoma, which frequently shows distant extracranial metastases, such an event is ex…

Hemangiopericytoma: A cause of recurrent epistaxis

2020

Hemangiopericytoma is a soft tissue tumor with histological variability and unpredictable clinical and biological behavior. this disease is uncommon in the head and neck and the growth pattern is unspecific; thus, diagnosis is often made by exclusion. A 43-year-old woman presented with a story of recurrent epistaxis associated to a growing mass in the paranasal sinus and a paraneoplastic syndrome. the imaging revealed an hypervascular tumor in the right nasal cavity and obliteration of all the ipsilateral sinus cavities. after biopsy the lesion was removed with resolution of epistaxis and paraneoplastic syndrome. There has been no evidence of disease recurrence in 3 years of follow-up. Our …

RETROVESICAL MASS IN MEN

1999

We review the differential diagnosis and treatment of retrovesical masses in men.During the last 8 years 21 male patients 3 to 79 years old (mean age 47.1) presented with symptoms or signs of a retrovesical mass. Clinical features and diagnostic findings were reviewed, and related to surgical and histopathological findings.The retrovesical masses included prostatic utricle cyst in 3 cases, prostatic abscess in 1, seminal vesicle hydrops in 6, seminal vesicle cyst in 2, seminal vesicle empyema in 3, large ectopic ureterocele in 1, myxoid liposarcoma in 1, malignant fibrous histiocytoma in 1, fibrous fossa obturatoria cyst in 1, hemangiopericytoma in 1 and leiomyosarcoma in 1. In 17 patients …

Fine structural features of the cerebral microvasculature in hydrocephalic human infants: correlated clinical observations.

1989

Four of 30 human cerebral cortex biopsies from infants ranging from four days to about ten years treated for hydrocephalus by shunt operations are described paying special attention to the vascular structures. The biopsy specimens were studied in semi-thin and ultrathin sections. Attention is drawn to the role of pinocytotic vesicles found in capillaries and smaller vessels as a possible transcellular route for the hydrocephalic oedema resolution. No intercellular dehiscences or the so called blisters were observed. With the passage of time, the number of membrane bound vesicles increased and arrays of pinocytotic vesicles were discernible both on the abluminal as well as luminal aspect of …

2013

Cortical function is impaired in various disorders of the central nervous system including Alzheimer’s disease, autism and schizophrenia. Some of these disorders are speculated to be associated with insults in early brain development. Pericytes have been shown to regulate neurovascular integrity in development, health and disease. Hence, precisely controlled mechanisms must have evolved in evolution to operate pericyte proliferation, repair and cell fate within the neurovascular unit (NVU). It is well established that pericyte deficiency leads to NVU injury resulting in cognitive decline and neuroinflammation in cortical layers. However, little is known about the role of pericytes in pathop…

2015

AbstractAccumulating evidence suggests a pivotal role of PDGFRß positive cells, a specific marker for central nervous system (CNS) pericytes, in tissue scarring. Identification of cells that contribute to tissue reorganization in the CNS upon injury is a crucial step to develop novel treatment strategies in regenerative medicine. It has been shown that pericytes contribute to scar formation in the spinal cord. It is further known that ischemia initially triggers pericyte loss in vivo, whilst brain trauma is capable of inducing pericyte detachment from cerebral vessels. These data point towards a significant role of pericytes in CNS injury. The temporal and spatial dynamics of PDGFRß cells a…

Vascular endothelial growth factor-A and platelet-derived growth factor-B combination gene therapy prolongs angiogenic effects via recruitment of int…

2008

Vessel stabilization and the inhibition of side effects such as tissue edema are essential in angiogenic gene therapy. Thus, combination gene transfers stimulating both endothelial cell and pericyte proliferation have become of interest. However, there is currently little data to support combination gene transfer in large animal models. In this study, we evaluated the potential advantages of such a strategy by combining the transfer of adenoviral (Ad) vascular endothelial growth factor (VEGF)-A and platelet-derived growth factor (PDGF)-B into rabbit hindlimb skeletal muscle. AdLacZ alone or in combination with AdVEGF-A were used as controls. Contrast-enhanced ultrasound, modified Miles assa…

Hemangiopericytoma of the Lung - a Rare Differential Diagnosis of Lung Tumors

1988

The authors report of a 50 year old woman who was operated on because of a rectum carcinoma 5 years ago. At a follow-up examination a 2 x 2 x 1 cm sized tumor was found in the lower lobe of the right lung. Under the diagnosis of lung metastasis after rectum carcinoma resection, operation (wedge resection) was carried out. The histological examination revealed the rare tumor hemangiopericytoma. Based on this case, frequency of the tumor, clinical symptoms, surgical treatment, prognosis as well as recurrence rate and formation of metastases are discussed.

Microphthalmia, persistent hyperplastic hyaloid vasculature and lens anomalies following overexpression of VEGF-A188 from the αA-crystallin promoter

2007

Purpose During growth of the embryonic eye, dose- and site-specific expression of heparin-binding growth factors is critical for the formation of an appropriate vascular supply. Overexpression of vascular endothelial growth factor-A188 (VEGF-A188), a strongly heparin-binding, endothelial-specific mitogen, leads to severe disturbance of vascular and overall ocular morphology. This study aimed to evaluate the effects of VEGF-A188 overexpression on growth of ocular tissue components. Methods Stereological and immunohistochemical methods were employed to identify the vascular profiles, ocular tissue proportions, and cell types in VEGF-A188 transgenic mice and compare them with wild-type mice. R…