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)

Nickel sub-sulphide-induced leiomyosarcomas in rabbit white skeletal muscle were studied by both light and electron microscopy. Two types of tumor cells, small spindle cells and elongated smooth muscle cells, are revealed by light microscopy. Nevertheless, their ultrastructure displays the same general feature. The most differentiated cells have abundant cytoplasmic filaments 7 nm in diameter, kept together in bundles by dense bodies. There also exist many 10 nm filaments and a large number of microtubules. The nuclei have prominent nucleoli with an extensive nucleolonema which form an irregular tridimensional network. Distinct fibrillar nuclear bodies were observed. Sometimes there exist desmosomes or gap junctions. The Golgi apparatus produces coated vesicles with secretory function. In the tumors were generally found the Ni3S2 implantations surrounded by a capsule, the major component of which were collagen fibers, degenerated nuclei and rod-like structures with a transverse periodicity of 15.5 nm. From these observations, several characteristics should be pointed out: 1) Many tumor cells contain large nucleoli and distinct intranuclear inclusions of undetermined nature. 2) The coated vesicles represent a secretory activity of the tumor cells; the coat material is probably used during the formation of cell membranes. Another possible function of coated vesicles could be the sequestering of calcium ions. 3) The rod-like structures in the Ni3S2-including capsule are not of Z-line material. 4) The tumoral stem myoblast in heart and skeletal muscle arise from mesenchymal cells.
 ...
PMID:Nickel sub-sulphide-induced leiomyosarcoma in rabbit white skeletal muscle: a light microscopical and ultrastructural study. 44 36

A case of a 46-year-old Japanese male having fibrosarcoma of bone is reported. The tumor developed in the proximal metaphysis of the left femur. During the three years following onset of the disease with symptoms of local pain and mass, the patient was operated on three times (curettage and bone graft, curettage and bone graft with Jwett's nail fixation and disarticulation). The tumor was found to be an intraosseous translucent lesion on x-ray examiation. Histologically, the tumor consisted of compact or loose, atypical spindle cells, producing abundant collagen-fibers without any osteoid, bony or cartilage formation. From the clinical and pathological findings, this case is thought to be a typical central fibrosarcoma of bone.
 ...
PMID:Central fibrosarcoma of bone. Report of a case. 45 4

We report on a case of a 40 years old female patient with a lentil-sized tumor of the left pinna present since early childhood. Histologic examination revealed pigmented granular "rankenneuroma". The lesion is unencapsulated but fairly well marginated in the dermis. It is composed of varying numbers of spindle-shaped or polyhedral cells arranged in intertwining and parallel bands separated by strands of collagen. The fascicles follow the preexisting nerve truncs. All layers of the dermis may be involved, but only rarely is the superficial subcutaneous tissue invaded. The fascicles of the tumor are generally constructed in a similar fashion. In the center one see argyrophile granular alterated unpigmented cells- Those elements are surrounded by mostly bipolar cells containing varying amounts of melanin. Silverstaining shows transition from spindle-shaped cells to granular degenerated elements. It is thought that the tumor most likely originates from the proliferation of the granular degenerated Schwann cells. The characteristic feature of tumor parenchyme is the association of the granular Schwann cells with cutaneous melanoblasts.
 ...
PMID:[Histology of the pigmented granular rankenneuroma (author's transl)]. 46 35

The nature of collagen from 2 cases of dermatofibrosarcoma protuberans was studied. For this purpose, the tumor tissue was carefully separated from adjacent normal dermis. The collagen types comprised in the tumor were identified by CM-cellulose chromatographic and SDS-gel electrophoretic analysis of the component alpha-chains. Semiquantitative evaluation of the relative type III content was established by separation of the cyanogen bromide peptides on gels of 12% polyacrylamide in SDS. These studies showed that dermatofibrosarcoma protuberans contains alpha 1(I)-, alpha 2-, and alpha 1(III)-chains as well, and corresponding type I- and type III-related CNBr peptides. Comparing the collagen from dermatofibrosarcoma protuberans to that of normal skin, the relatively increased type III content in the case of dermatofibrosarcoma protuberans becomes apparent.
 ...
PMID:Nature of collagen in dermatofibrosarcoma protuberans. 47 45

This is a case report of a patient who had a desmoid tumor which localized 99mTc-diphosphonate. The mechanism for this localization was felt to be the affinity of the bone agent for the immature proliferating collagen in this tumor.
 ...
PMID:Localization of bone-seeking agent within a desmoid tumor. 47 46

Tumour extracts were obtained from rat Walker 256 carcinoma and examined for the presence of tumour angiogenesis factor (TAF) in vivo before being used in tissue culture experiments. Capillary endothelial cells derived from cow brain white matter were used to study the effects of TAF-containing tumour extracts on cell proliferation in vitro. The cells were grown on two types of substrata: (1) plastic tissue culture dishes and (2) hydrated gels made of rat tail tendon type I collagen. Human platelets or platelet-released factors were introduced into the system because of the many inter-relationships known to exist between platelets, collagen and endothelial cells. If trypsin was used during the preparation of TAT, the resulting batches stimulated endothelial cell proliferation only when the cells were growing on a collagen substratum and either platelets or platelet-released factors were present in the growth medium. If incubation with trypsin was omitted from the TAF extraction procedure, the resulting batches stimulated cell growth both on plastic and on collagen. A synergistic interaction also occurred between these TAF-containing tumour extracts and platelet-released factors. This effect was always more marked when the cells were growing on collagen than when on plastic. These data suggest that the nature of the substratum affects the response of the endothelial cells to TAF and to platelet-released factors.
 ...
PMID:Importance of a collagen substratum for stimulation of capillary endothelial cell proliferation by tumour angiogenesis factor. 48 64

Nine patients underwent transcatheter embolization with a suspension of microfibrillar collagen hemostat (MCH). Four of the patients had large vascular renal tumors, and two had bleeding bladder carcinomas. There was one case each of bleeding rectal tumor, bleeding esophageal varices, and arteriovenous malformation of the shoulder. MCH was highly thrombogenic and could be injected through very small catheters. It was highly effective as an occlusive agent and was able to penetrate the small end-arteries of a lesion. Its main disadvantage is that if normal tissues are inadvertently embolized, there is a risk of ischemic complication.
 ...
PMID:Microfibrillar collagen hemostat: a new transcatheter embolization agent. 50 62

After observing the presence of numerous stromal myofibroblasts in scirrhous mammary carcinomas, a series of invasive and metastatic carcinomas from diverse sites was examined by electron microscopy to determine whether myofibroblasts might also be present in their stroma. Myofibroblasts were identified in each instance and were most abundant in neoplasms which were hard, sclerotic, and retracted. This finding suggests that myofibroblasts represent a component of the stromal reaction to many carcinomas and contribute to the desmoplasia and retraction which characterize many of these neoplasms. The host commands several responses to neoplasia. As a result of the expression of tumor-associated antigens, the immune system contributes lymphocytes, macrophages, and antibodies, a reflection of immunologic surveillance against neoplasia. In contrast to experimental systems tumor neoantigens are poorly expressed or even lacking in many human neoplasms; thus, the immune system may be weakly stimulated or not activated at all. Tumor neovascularization induced by a tumor-angiogenesis factor represents a second host response, possibly deleterious, for it may facilitate tumor dissemination. The stromal myofibroblast reaction to many invasive and metastatic carcinomas may constitute a third, albeit more primitive response. The density of collagen produced and contractile state of such tissue may signify an attempt by the host stroma to contain the neoplasm and impede vascular invasion. If so, myofibroblast induction may complement immune surveillance or constitute a separate mechanism of response to invasive neoplasia in man.
 ...
PMID:Myofibroblasts in the stroma of invasive and metastatic carcinoma: a possible host response to neoplasia. 53 89

Two cases of a typical hairy cell leukemia are presented. The light microscopic findings within the bone marrow, lymph nodes and spleen are documented. The hairy configuration of tumor cells can best be seen in semithin sections of white cells of the peripheral blood. Electron microscopically, the organelle composition of hairy cells (including the characteristic ribosome lamellae complex) is demonstrated. The significance of morphological observations for the diagnosis of hairy cell leukemia and the differential diagnosis of this tumor disease are discussed. From the electron microscopic observations of intercellular cross-banded structures it seems possible that the increase of intercellular material demonstrable light microscopically by silver impregnation is the consequence of synthesis of collagen type IV. The conclusion is drawn from findings in our cases and from reports in the literature that hairy cell leukemia is a clinically and structurally defined syndrome rather than a pathological entity.
 ...
PMID:[Hairy cell leukemia. Light and microscopic and electron microscopic examinations (author's transl)]. 53 72

Ultrastructural examination of an alveolar rhabdomyosarcoma revealed that the bulk of the tumor was composed of small polygonal cells containing polyribosomes, short strands of rough endoplasmic reticulum, and variable amounts of glycogen; the cells were joined by small desmosome-like structures. Similar cells, as well as a variety of larger forms which appeared to be derived from the small cells, were observed along the septa; the larger forms developed a copious cytoplasm and occasionally produced myofilaments. Some of these cells were separated from the septa by basement membranes. Giant cells were also present in the alveolar spaces; these formed neither basement membranes nor myofilaments. The septa themselves were composed largely of collagen and fibroblasts. It is suggested that the commonly proposed correspondence of alveolar rhabdomyosarcoma to the myotube stage of muscle differentiation is incorrect; if anything, the overall pattern of the tumor is epithelial-like, and may correspond to the organization of mesenchymal cells at the stage of somite differentiation. The resemblance of the masses of small tumor cells to the cells of Ewing's sarcoma is discussed.
 ...
PMID:Ultrastructural observations on the histogenesis of alveolar rhabdomyosarcoma. 56 50


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