Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It has been proposed that the skin is a functionally unique compartment of the immune system, although little direct evidence supporting this hypothesis has been presented. Here we show that lymphocyte populations at cutaneous sites can be differentiated from otherwise similar populations at noncutaneous sites by their preferential expression of an epitope defined by the MAb HECA-452. This MAb recognizes a predominantly 200-kd cell-surface glycoprotein present on about 16% of peripheral blood T cells, including both CD4+ and CD8+ T cells (17% and 11% HECA-452+, respectively), as well as TCR-delta-bearing T cells (32%+). Most thymocytes (99%) lacked HECA-452 antigen expression, and essentially all the HECA-452+ peripheral blood T cells were found in the adhesion molecule high, CD45R low putative memory cell subset, findings suggesting that HECA-452 expression develops peripherally as a consequence of antigenic stimulation. However, the HECA-452 antigen is not a conventional activation antigen because it was not upregulated with mitogen stimulation of peripheral blood T cells. Most significantly, among 54 diverse specimens of normal/reactive lymphoid tissues and sites of chronic inflammation, there was a clear association of lymphocyte HECA-452 expression and cutaneous location. In extracutaneous sites (n = 38) only about 5% of lymphocytes within the T-cell areas of these tissues expressed this antigen, whereas in inflammatory skin lesions (n = 16), 85% were HECA-452+. The association of HECA-452 expression and cutaneous location was also seen in a series of T-cell lymphomas. The malignant cells of 16 of 18 cases of epidermotropic (patch/plaque) stage mycosis fungoides were HECA-452+, as well as 2 of 7 nonmycosis fungoides peripheral T-cell lymphomas in skin. In contrast, this antigen was not expressed in thymic (lymphoblastic) lymphomas (n = 14), nonepidermotropic (tumor) stage mycosis fungoides (n = 5), and noncutaneous peripheral T-cell lymphomas (n = 15). Among lymphocytes, the preferential expression of the HECA-452 determinant by cutaneous T cells supports the hypothesis that the skin constitutes a immunologically unique lymphoid tissue and suggests that this molecule may play a role in either lymphocyte homing to skin or in lymphocyte interactions with the epidermis.
 ...
PMID:A unique phenotype of skin-associated lymphocytes in humans. Preferential expression of the HECA-452 epitope by benign and malignant T cells at cutaneous sites. 169 67

The histogenesis of Kaposi's sarcoma (KS) has been the subject of controversy, much of which has centered around whether the spindle cells of KS are derived from vascular endothelium or from lymphatics. Recently, some investigators have speculated that the spindle cells of KS are derived from dermal dendrocytes, a population of mononuclear dendritic cells normally present in the papillary and upper reticular dermis. These cells have been shown to proliferate in response to a variety of stimuli and have been reported to express the plasma proenzyme factor XIIIa. We examined immunohistochemically sections fixed in formaldehyde solution and embedded in paraffin from 20 tumor-stage, 15 patch-stage, and 15 plaque-stage lesions of KS with antibodies directed against factor XIIIa, factor VIII-related antigen, Ulex europaeus lectin, and LN3 (anti-HLA-DR) to investigate the relationship of dermal dendrocytes to KS in general and to try to clarify the histogenesis of this tumor. Our results revealed that the dermis of patch- and plaque-stage KS lesions contains an increased number of factor XIIIa-positive dermal dendrocytes compared with normal dermis and that some of these cells are spindle shaped. Many of the spindle cells in patch- and plaque-stage lesions of KS, however, are negative for factor XIIIa. The cells lining the slitlike spaces and some spindle-shaped cells in close proximity to the vascular spaces stain for factor VIII-related antigen and for Ulex europaeus lectin. LN3 labeled many cells resembling macrophages within the lesions and in papillary dermis. Less than 25% of the dendritic cells within the lesions and in the adjacent dermis expressed both factor XIIIa and LN3. Tumor-stage lesions showed focal but unequivocal staining of the spindle cells for factor VIII-related antigen and Ulex europaeus lectin. Tumor spindle cells were negative for factor XIIIa. Factor XIIIa-positive dendrocytes were plentiful in the uninvolved dermis and were aggregated around the periphery of the tumor nodules. The expression of factor VIII-related antigen and Ulex europaeus lectin by the spindle cells of nodular KS, and their lack of expression of factor XIIIa, suggests that the spindle-shaped tumor cells in all stages of KS are derived from endothelial cells and not from dermal dendrocytes. Dermal dendrocytes appear to undergo hyperplasia in response to KS of all stages. In patch- and early plaque-stage KS lesions, dermal dendrocytes are near factor VIII-related antigen-positive spindle cells and tumor vessels. The mechanism reactive dermal dendrocyte hyperplasia in KS remains obscure.
 ...
PMID:Relationship of factor XIIIa-positive dermal dendrocytes to Kaposi's sarcoma. 171 58

The population of CD1a+ cells and the quantity of Birbeck granules were evaluated in comparison with the population of T lymphocytes in a variety of clinical lesions of mycosis fungoides. Anti-CD1a and Lag antibodies that specifically react with Birbeck granules and related structures of human Langerhans cells were used immunohistochemically. CD1a+ cells in the dermis of lesions of mycosis fungoides significantly increased in plaques of the plaque stage and in plaques of the tumor stage. They were most frequent in lesions with CD4+ cells ranging in number from 100 to 150/mm2. These lesions were suspected to be progressing from the plaque to the tumor stage. During the course of the disease, most of the dermal CD1a+ cells had few Lag antigens. These results suggest that dermal CD1a+Lag- cells may promote the progression of mycosis fungoides from the plaque to the tumor stage.
 ...
PMID:A subpopulation of Langerhans cells (CD1a+Lag-) increased in the dermis of plaque lesions of mycosis fungoides. 171 24

The enhanced and unenhanced MR examinations obtained after surgery for meningioma in 38 patients were reviewed to determine the value of enhanced vs unenhanced MR imaging for the detection of residual or recurrent tumor. Enhanced images improved delineation of the extent of tumor in seven of 13 cases in which meningioma was identified on unenhanced images and allowed more definitive detection or exclusion of residual or recurrent meningioma in 18 of 21 cases with equivocal findings on unenhanced images. In addition, enhanced images were helpful for detecting small recurrences, identifying en plaque growth, and showing subtle progression on serial studies. Enhanced MR imaging also allowed detection of two morphologic patterns of dural enhancement adjacent to the surgical bed: (1) thin and smooth, which was seen in patients both with and without residual or recurrent tumor, and (2) thick and nodular, which was seen only in patients with findings indicative of, or at least suggestive of, residual or recurrent meningioma. Unenhanced images failed to detect, or poorly detected, these dural abnormalities. Unenhanced sequences were necessary for accurate interpretation of the enhanced images (e.g., identification or exclusion of hemorrhage). The combination of unenhanced and enhanced MR imaging is recommended for the detection of residual or recurrent meningioma after surgery.
 ...
PMID:Detection of residual or recurrent meningioma after surgery: value of enhanced vs unenhanced MR imaging. 173 12

We compared the ocular radiation distribution of palladium 103 (103Pd) vs iodine 125 (125I) ophthalmic plaques sewn to 12 human donor eyes. We then performed preoperative comparative simulations on the first seven patients to be treated with palladium 103 plaque therapy for choroidal melanoma. The in vitro experiment involved palladium 103 seeds placed into a Silastic seed holder, which was affixed into standard 14-mm gold eye plaques. Then the plaques were sewn onto 12 human donor eyes so as to approximate either the nasal (six eyes) or temporal (six eyes) equator. Three sets of two thermoluminescent dosimeters were used to quantify the amount of radiation delivered by the episcleral plaques. Thermoluminescent dosimeters were sewn to the sclera in three locations: on the center of the cornea, on the sclera beneath the macula, and at the equator in a position opposite the plaque. This experiment was then repeated with iodine 125 seeds and thermoluminescent dosimeters. After the plaques were adjusted to equalize their activity (plaque strength), the palladium 103 plaques were found to deliver less radiation to the three target points. Comparative clinical dosimetry also reflected this difference. Preoperative simulations comparing equal doses to the tumors' apex revealed that the palladium 103 ophthalmic plaques delivered more radiation to the tumor and less radiation to most normal ocular structures.
 ...
PMID:Palladium 103 ophthalmic plaque radiotherapy. 175 46

Ten patients with large melanomas and one patient with recurrent retinoblastoma were treated with combined localized current field (LCF) hyperthermia and iodine 125 irradiation delivered by episcleral plaque. Tumors were heated to 43 degrees to 45 degrees C for 28 to 45 minutes. Localized current field hyperthermia when combined with irradiation appeared to induce rapid tumor necrosis. One eye enucleated 17 hours after treatment showed only focal necrosis of the melanoma, while another eye demonstrated extensive necrosis 60 hours after treatment. In all remaining eyes, tumor regression occurred within the first month of treatment. Complications included cataract formation in six eyes, hemorrhagic retinal detachment in five eyes, and phthisis in two eyes. Complications from combined therapy of large intraocular tumors in this series appeared to result from the rapid necrosis of the tumor and secondary intraocular inflammation. Intraocular temperature dosimetry measurements demonstrated a temperature gradient of not more than -0.23 degrees C/mm-1 per axial millimeter from the episcleral plaque surface to the apex of the tumor. The authors believe that LCF hyperthermia could be a suitable means of application of hyperthermia in patients with intraocular tumors if further modifications were performed to reduce ocular complications.
 ...
PMID:Combined localized current field hyperthermia and irradiation for intraocular tumors. 177 18

In recent years, there have been a number of advances in the diagnosis and management of patients with malignant melanoma of the posterior uvea (ciliary body and choroid). This review provides a brief update on the current status of diagnostic modalities, such as fluorescein angiography, ultrasonography, computed tomography, magnetic resonance imaging, fine needle aspiration biopsy, and the radioactive phosphorus uptake test. Following that is a more detailed review of the current controversy regarding the natural course of uveal melanomas and the available therapeutic modalities. Current indications, techniques, complications, and results are provided for various forms of management, such as observation, laser photocoagulation, plaque radiotherapy, charged particle radiotherapy, local tumor resection, enucleation, and orbital exenteration.
 ...
PMID:Management of posterior uveal melanoma. 177 22

A review of 3706 consecutive patients with uveal melanoma revealed that 40 patients (1.1%) were age 20 years or younger at the time of diagnosis. The youngest patient was age 6 years but the majority of patients (78%) were between 15 and 20 years old. The tumor occurred in the iris in 5 cases (12%) and in the posterior uvea in 35 cases (88%). The mean largest tumor dimension and thickness was 10 mm and 5 mm, respectively. In all cases, the diagnosis of uveal melanoma was suspected before referral, and misdirected treatment was avoided. The tumor was initially treated by enucleation in 24 cases (60%), local resection in 7 (18%), plaque radiotherapy in 3 (8%), and observation in 6 (15%). Secondary treatment was required in 7 cases in the form of enucleation (4 cases), ablative laser (1 case), plaque radiotherapy (1 case), and exenteration (1 case). The mean follow-up period was 68 months (median, 48 months) from the time of treatment, and only one patient died of metastases (from a massive ciliochoroidal melanoma 33 months after treatment). The remainder of the group of young patients are alive and healthy. Cumulative survival rates show that 96% of young patients with uveal melanoma survive at the 5-year period.
 ...
PMID:Uveal melanoma in teenagers and children. A report of 40 cases. 180 Sep 26

The association between ocular squamous cell tumors and various measures of solar radiation was evaluated for 2,775 contemporaneous Hereford cattle. The animals were from 34 herds located in 21 states in the United States and in one Canadian province. Examinations and photographs were made of the eyes of all cows and heifers in a herd; 33 herds were examined between June and August 1957 and 1 herd was examined in 1958. Solar radiation was measured by altitude and mean annual hours of sunshine applying to an individual herd, and global radiation, a cloudiness index, and elevation of nearby National Weather Service stations. All measures of solar radiation provided evidence of a significant association between increasing risks of developing cancer eye and increasing levels of radiation; adjustments were made for possible confounding effects of age and corneoscleral pigmentation. Associations were evident whether affliction was defined as the occurrence of any type of tumor (ie, plaque, papilloma, or carcinoma), or as the occurrence of only papilloma or carcinoma. Average ages of affected cattle also tended to be lower at high radiation levels than at low levels, further supporting the hypothesis that solar radiation has an important role in the development of this disease. In view of the heritability of eye pigmentation and its inhibitory effect on lesions, cancer eye may be controlled by selective breeding for increased pigmentation in and around the eye to afford protection against the harmful effects of incident UV radiation.
 ...
PMID:Association between solar radiation and ocular squamous cell carcinoma in cattle. 185 7

The authors investigated the impact of local intraocular tumor relapse on survival in a matched-group comparison study of patients with primary choroidal or ciliary body melanoma managed with cobalt 60 plaque radiotherapy. Sixty-two patients with local relapse were matched with an equal number of relapse-free patients in terms of known clinical prognostic factors for both melanoma-specific mortality (largest linear tumor dimension, location of anterior tumor margin, age) and local tumor relapse (location of posterior tumor margin). The follow-up of every relapse-free patient equaled or exceeded the interval to relapse for each matched patient with local relapse. The estimated 5-year survival (Kaplan-Meier) in the relapse-free patients was 87% (standard error = 4%), while that in the local relapse group was 58% (standard error = 6%). This difference is statistically significant (P less than 0.0001, log rank test). These results support the hypothesis that local tumor relapse after cobalt 60 plaque radiotherapy is an important post-treatment clinical indicator of the tumor's greater malignant potential and the patient's increased risk of melanoma-specific mortality.
 ...
PMID:Impact of local tumor relapse on patient survival after cobalt 60 plaque radiotherapy. 186 54


<< Previous 1 2 3 4 5 6 7 8 9 10