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)

Mast cells (MCs) always accompany connective tissue and are located in the proximity of lymphatic and blood vessels and nerve fibers. They are round or oval mononuclear cells with a diameter of 4-20 microm containing in their cytoplasm specific exocrine granules (storing neutral proteases) enclosed by a single membrane, whose presence is regarded as an index of the MC's static state. In view of their wide distribution in the organism, they play various roles in, for example, type I hypersensitivity reactions, chronic inflammatory processes, tissue reconstruction and wound healing, and pathological pulmonary fibrosis. They also play a role in angiogenesis, both in normal conditions during tissue regeneration and in pathological neoplastic states. The microcirculation provides building and nutritional substances to cancer cells and enables cancer spread via the blood. On the other hand, a tumor with good vascularization is more prone to penetration by cytostatics, which is why angiogenesis is a very important process in the course of neoplastic disease. Many authors indicate a close association between mast cells and angiogenesis. Some substances contained in the cytoplasm of these cells are potent stimulators of angiogenesis (tryptase, heparin), while others may inhibit it (protamine, platelet factor 4), and this conditions cancer growth and the development of the metastatic process. It is not known, however, what interactions occur between stimulants and inhibitors and what the proportional involvement of particular mediators in the formation of new vessels is.
Med Sci Monit 2006 Mar
PMID:Mast cells in neoangiogenesis. 1673 92

Cellular therapy is the replacement of unhealthy or damaged cells or tissues by new ones. Embryonic stem (ES) cells are undifferentiated cells that can generate all the cell types of the body, and therefore hold the potential to cure a broad range of diseases and injuries, ranging from diabetes, liver and heart diseases, to neurological diseases, such as Alzheimer's and Parkinson's diseases. The derivation of human ES (hES) cells has been a major step toward bringing ES cell research to therapy. However, there are several challenges to the advent of ES cell research to therapy. Among them, the derivation of hES cell lines devoid of animal contaminants, the maintenance of their normal karyotypes, their potentials to form tumors upon grafting, and the derivation of isogenic hES cell lines. Stringent ethical and political guidelines are also limiting the use of human embryos for research, thereby limiting progress in ES cell research. Recently, several investigators have devised protocols to derive hES cells free of feeder layer and animal serum, reported that some established cell lines remain stable overtime, pre-differentiated ES cells in vitro to circumvent the risk of tumor formation, and derived ES cell lines without destroying embryos. In this manuscript, we will review and discuss these developments that may unlock ES cell research and therapy.
Med Sci Monit 2006 Apr
PMID:Derivation of embryonic stem cells for cellular therapy: challenges and new strategies. 1657 64

Amidst controversy about methodology and safety, intraoperative neurophysiology has entered a new era of increasingly routine transcranial and direct electrical brain stimulation for motor evoked potential (MEP) monitoring. Based on literature review and illustrative clinical experience, this tutorial aims to present a balanced overview for experienced practitioners, surgeons and anesthesiologists as well as those new to the field. It details the physiologic basis, indications and methodology of current MEP monitoring techniques, evaluates their safety, explores interpretive controversies and outlines some applications and results, including aortic aneurysm, intramedullary spinal cord tumor, spinal deformity, posterior fossa tumor, intracranial aneurysm and peri-rolandic brain surgeries. The many advances in motor system assessment achieved in the last two decades undoubtedly improve monitoring efficacy without unduly compromising safety. Future studies and experience will likely clarify existing controversies and bring further advances.
J Clin Monit Comput 2006 Oct
PMID:Intraoperative motor evoked potential monitoring: overview and update. 1683 80

Although tumor size and grade are well-established prognostic parameters in unselected series or in advanced cases of invasive breast carcinoma, studying their prognostic value in small invasive carcinomas has generated variable results. The significance of these parameters was recently questioned in three large studies on invasive carcinomas less than 15 mm in size, in which neither grade nor size were found to be independent prognostic parameters. Two of these studies were carried out on material of our institution and evidenced the outstanding prognostic significance of a radiological parameter (presence of casting type microcalcifications) in these tumors, challenging the traditional approach in breast pathology in which conventional morphologic prognostic parameters are clearly insufficient to explain these results. In the present article we discuss the practical difficulties in measuring and grading invasive breast carcinomas to point out the disturbing lack of wide international consensus considering the optimal assessment of these parameters, contributing to discordant results in the reviewed studies. We also present the unifying concept of the theory of the sick lobe which, by shifting the focus from the debated details of measuring and grading towards the judgement of the pattern of tumoral growth, offers alternative morphologic prognostic parameters which fulfill the needs of a modern interdisciplinary approach to diagnosing small breast carcinomas.
Med Sci Monit 2006 Aug
PMID:The limited prognostic value of measuring and grading small invasive breast carcinomas: the whole sick lobe versus the details within it. 1686 79

Despite scientific efforts and significant progress in understanding the basic cellular event in pancreatic adenocarcinoma (PA), survival rates have not changed much during the last 20 years. Prognosis in pancreatic cancer remains unsatisfactory due to its late clinical presentation, low surgical resectability rates, and resistance to chemotherapy. Novel therapeutic strategies are needed in order to improve the prognosis of patients with PA. Improvement of our knowledge of the molecular biology of pancreatic cancer may have important clinical implications in pancreatic cancer risk assessment, early diagnosis, and management. In human pancreatic cancer, a specific sequence of oncogene and tumor suppressor gene alterations is observed, including K-ras, HER-2/neu, p16, p53, and DPC4. The prevalence of these genetic alterations rises with increasing severity of dysplasia of the ductal mucosal lesions. Drugs that target these molecular abnormalities hold great promise for PA treatment in the near future. The focus of this review is to evaluate the gene mutations in pancreatic cancer, with emphasis on those studies that are most important to the clinical practice. Our review also summarizes current aspects of PA treatment and the differential diagnosis of pancreatic cancer and chronic pancreatitis.
Med Sci Monit 2006 Sep
PMID:Molecular pathogenesis of pancreatic adenocarcinoma: potential clinical implications. 1694 Sep 43

Gamma-linolenic acid (GLA) induced apoptosis of tumor cells without harming normal cells. Both cyclo-oxygenase (COX) and lipoxygenase (LO) inhibitors did not inhibit the selective tumoricidal action of GLA in some, but not all, tumor cells suggesting that GLA by itself is active. In contrast, anti-oxidants such as vitamin E blocked the tumoricidal action of GLA. GLA-treated tumor but not normal cells produced a 2-3-fold increase in free radicals and lipid peroxides. GLA decreased the anti-oxidant content of tumor cells, expression of oncogenes ras, and Bcl-2, enhanced the activity of p53, protected normal cells and tissues from the toxic actions of radiation and anti-cancer drugs, enhanced the cytotoxic action of anti-cancer drugs and reversed tumor cell drug resistance. In the animal glioma model, GLA induced tumor regression and preserved the surrounding normal brain tissue. In three open-label clinical studies, intra-tumoral injection of GLA induced significant reduction of glioma without any significant side effects. The low neurotoxicity of GLA to normal brain neurons and selective activity against tumor cells suggests that it could be an effective anti-glioma molecule.
Med Sci Monit 2007 Jul
PMID:Gamma-linolenic acid therapy of human glioma-a review of in vitro, in vivo, and clinical studies. 1759 36

The development of cancer cachexia is perhaps the most common manifestation of advanced malignant diseases and has been recognized as a poor prognostic sign. The abnormalities associated with the condition include progressive weight loss, anorexia, asthenia, and anemia. The degree of cachexia is inversely correlated with the survival time of the patient and always implies a poor prognosis. Currently there is no established mechanism for cancer cachexia, but the severe metabolic disturbances and marked alterations in carbohydrate, lipid, and protein metabolism in the host finally lead to an increased energy deficiency. Weight loss, the key feature of cachexia, is due to a reduction of food intake, an increase in energy expenditure, or a combination of the two. A variety of changes in nutrient metabolism have been described in patients with cancer cachexia. Patients frequently exhibit a relative glucose intolerance and insulin resistance with increased activity of the Cori cycle. The cancer-bearing state affects protein synthesis and breakdown in different tissues of the body in a different manner. An acute-phase protein response can be presented in a significant proportion of patients with cancer with disease progression. A variety of proinflammatory cytokines appears to play a role in aspects of cachexia and a complex network of cytokines in combination with other factors might be involved. Aside from potential humoral mediators of cachexia, tumor-derived biologically active molecules have been reported recently.
Med Sci Monit 2007 Sep
PMID:Current perspectives of catabolic mediators of cancer cachexia. 1776 31

Tumor oxygenation status is tightly regulated and correlates with its aggressive behavior. Hypoxia plays critical roles in tumor progression including tumor angiogenesis, mutation rate, metastasis and resistance to radiation and chemotherapy. Many molecular pathways have been recognized to mediate these hypoxia-induced responses in tumors. For example, extensive studies demonstrate that hypoxia-inducible factor-1 (HIF-1) is a key molecule in regulating tumor responses to hypoxia. Many other genes including growth factors, glycolytic enzymes, cytokines, and transcription factors are inducible by hypoxia via either HIF-1-dependent or HIF-1-independent pathways. This review summarizes current advances in tumor hypoxia regarding new technologies of tumor hypoxia measurement, clinical and animal studies, cell culture models, the hypoxia-induced key molecules and therapeutic implications. This valuable information is particularly timely and helpful for clinicians and researchers who want to recognize the newest endeavors within the field and identify possible lines of investigation in tumor hypoxia.
Med Sci Monit 2007 Oct
PMID:Recent advances in tumor hypoxia: tumor progression, molecular mechanisms, and therapeutic implications. 1790 61

This review summarizes the most relevant data relating to the potential role of melatonin (pineal secretory product) as an adjuvant therapy of tumors. Results of clinical studies were preceded by a description of experiments conducted on tumor cell lines and on laboratory animals. Most of the reports unequivocally confirmed the antioxidative and immunostimulatory action of the pineal secretory product in both in vitro and in vivo experiments. Results of studies on cell lines of various tumors showed that the anti-proliferative effect of melatonin might involve a receptor-mediated mechanism. In experiments on animals, the cardio-, nephro-, and myelo-protective action of melatonin was confirmed in the course of application of various cytostatic drugs. A meta-analysis of clinical studies in which melatonin was applied as an adjuvant drug in the therapy of various tumors pointed to some effects of its administration. Therefore, the use of melatonin could offer hope in future antitumor therapy.
Med Sci Monit 2008 May
PMID:Melatonin: adjuvant therapy of malignant tumors. 1844 63

Bone defect is a common problem encountered in the treatment of musculoskeletal tumor surgery. Allograft is a commonly used technique to reconstruct a large osseous defect following tumor excision in the United States and some European countries, and relatively good results have been reported because of its biologic nature. However, with the use of an allograft, there are concerns of transmission of infectious diseases, immunological reactions, and social or religious refusal in some regions in the world. Under these circumstances, vascularized autogenous fibular or iliac bone grafts are commonly used techniques and bone lengthening techniques using external fixation have been reported recently. These procedures utilize viable bone. In addition to these procedures, some biological reconstructive techniques utilizing nonviable bone have been performed as surgical alternatives for allografts using treated recycling bone including irradiated or pasteurized resected bone graft and reconstruction using an autograft containing tumor treated by liquid nitrogen. Although each technique has its proper advantages and disadvantages, the clinical results are similar to the allograft, and numerous techniques are now available as reasonable alternatives for allografts.
Med Sci Monit 2008 Aug
PMID:Methods of reconstruction for bone defect after tumor excision: a review of alternatives. 1866 7


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