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

P-glycoprotein (Pgp), which is coded by human MDR1 (multidrug resistance) gene, is an energy-dependent efflux pump that exports its substrates out of the cell. Human Pgp is present not only in tumor cells but also in normal tissues including the kidney, liver, small and large intestine, brain, testis, and adrenal gland, and the pregnant uterus. This tissue distribution indicates that Pgp plays a significant role in excreting xenobiotics and metabolites into urine and bile and into the intestinal lumen, and in preventing their accumulation in the brain. The roles of Pgp in drug disposition include a urinary excretion mechanism in the kidney, a biliary excretion mechanism in the liver, an absorption barrier and determinant of oral bioavailability, and the blood-brain barrier that limits the accumulation of drugs in the brain. The inhibition of the transporting function of Pgp can cause clinically significant drug interactions and can also increase the penetration of drugs into the brain and the accumulation of drugs in the brain. Digoxin is a typical substrate for Pgp, which regulates the renal tubular secretion and brain distribution of digoxin. At present, potent Pgp inhibitors are being investigated in clinical trials aimed at overcoming the intrinsic or acquired multidrug resistance of human cancers. The clinical application of these Pgp inhibitors should take into consideration the physiologic function of pgp.
Ther Drug Monit 2000 Feb
PMID:Role of P-glycoprotein in drug disposition. 1068 77

Rituximab is a chimeric monoclonal antibody (MAb) directed against the B-cell CD20 antigen that has been approved for therapy of relapsed and resistant follicular non-Hodgkin's lymphoma (NHL). This study describes the development and validation of a highly sensitive, rapid, accurate, precise enzyme-linked immunosorbent assay (ELISA) to measure Rituximab serum concentrations. This study also describes the application of the ELISA method to a pharmacokinetic study in a homogeneous group of patients with follicular lymphoma who received 4 weekly doses of MAb at the standard dose of 375 mg/m2 as consolidation of chemotherapy. In the patients in this study, the median Rituximab serum concentrations increased during therapy, and showed a slow decline during the posttreatment period. The Rituximab elimination half-life of approximately 20 days accounts for the demonstrated accumulation of MAb in serum samples. Because previous pharmacokinetic studies showed a correlation between Rituximab serum levels and tumor response, the ELISA method used in this study, which allows a precise control of serum concentrations, could be useful for predicting the final response to the MAb and for selecting patients able to benefit from higher dosage or repeated drug administration.
Ther Drug Monit 2000 Jun
PMID:Rituximab (IDEC-C2B8): validation of a sensitive enzyme-linked immunoassay applied to a clinical pharmacokinetic study. 1085 Mar 96

From 1989, at the Department of Medical Oncology of the Institute for Oncology and Radiology in Belgrade, seven patients with primary NHL of large bowel and rectum have been observed and treated, 3 males and 4 females. In 3 patients an urgent laparotomy without previous diagnostic procedures was performed, while 4 patients had laparotomy only after radiographic and endoscopic diagnosis of a tumor. Six patients had radical surgery and 1 palliative only. Five patients had lymphoma localized in cecoascedental part of colon (2 centroblastic, 1 lymphoplasmocytic, 1 Burkitt and 1 Burkitt's like), 1 patient had it in the transversal part of colon (centroblastic), and one in the rectum (diffuse centrocytic). By further investigation, in 2 cases with localization within transversal part of colon and rectum no other sites of NHL were found. They are under regular controls with 45+ and 45+ months disease free survival. Out of 5 patients with localization within cecum or ascendent part of colon, in 2 cases with Burkitt/Burkitt-like histology retroperitoneal lymphadenopathy were found, one female had NHL central propagation, and the other one lymphoma generalization. Both patients had early death from lymphoma. The remaining three patients following chemotherapy with the ProMACE regimen (as they too had a post laparotomy stage II disease) achieved a complete response lasting for 36+, 41+ and 66+ months. Since the median survival in our group of patients is at the moment 41+ months and the median has not yet been reached, our experience does not confirm literature data claiming bad prognosis of primary NHL of the colon and rectum. A long disease free survival can be obtained in these patients either with surgery only or surgery + chemotherapy, depending on disease stage and possibly initial topographic localization.
Med Sci Monit
PMID:Non-Hodgkin's lymphomas with primary localization in large bowel and rectum. 1120 86

Isohaemagglutinin synthesis starts 2-4 months after birth, growing progressively and reaching adult values at the age of 5-10 years. Isohaemagglutinin concentration decreases with age. Isohaemagglutinins are mostly immunoglobulins belonging to the class IgM, but also IgA and IgG. Agglutination titter shows correlation with the total concentration of those three immunoglobulin isotypes. For the time being there are few data on the isohaemagglutinin titter level in various diseases. Purpose of this work is to determine whether there are any isohaemagglutinin titter alterations in patients with neoplasia. Isohaemagglutinin titter was investigated in 177 patients treated at the Institute of Oncology and Radiology and 340 blood donors. Out of 177 patients, 31 had Hodgkin's lymphoma (HL), 89 had non-Hodgkin Lymphoma (NHL) and 57 had metastatic solid tumors (MST). Statistical evaluation included Kruskal-Wallis and Mann-Whitney tests. In all groups of patients isohaemagglutinin titters were considerably lower as compared with the healthy population (p < 1 x 10e-5). There was a significant difference in titter values (p = 0.003) between O blood group patients with NHL where anti-A1 titter was significantly lower (Med = 8; range: 1-256) compared with anti-A1 titter in patients with O blood group suffering from MST (Med = 16; range: 2-64). Anti-B titter in the same groups of patients also showed lower values (p = 0.042); in NHL anti-B titter values was Med = 4, range: 1-32 vs Med = 8, range: 1-64 in MST. In the group of patients with HL, A blood group was far more frequent (17/31) compared with the group with MST (22/57) (p = 0.02). Pretherapy determination of isohaemagglutinin titter in patients with malignant diseases shows that it is significantly lower than the titter in healthy population. Abnormally low isohaemagglutinin titter value irrespective of the type and site of the malignant tumor, points to insufficiency of the IgM-related humoral immune response, to malignancy as a systemic disease, and places isohaemagglutinins among biological markers.
Med Sci Monit
PMID:Pretreatment determination of isohaemagglutinin titter values in patients with malignant lymphomas and metastatic solid tumors. 1120 85

We report two female patients with neurogenic tumors of the digestive tract. In the first patient, the tumor of 10 cm diameter originated in the stomach and at preoperative CT imitated a peripancreatic cyst. In the second patient, the tumor of 6 cm diameter originated in the duodenum. Despite large size, the tumors were clinically indolent and escaped detection at routine endoscopic evaluation. In both cases the neoplasm was removed and postoperative histopathology combined with immunohistochemistry was consistent with diagnosis of digestive Schwannoma.
Med Sci Monit
PMID:Neurogenic tumors of the digestive tract: report of two cases. 1120 43

Although the role of androgens and AR in breast cancer genesis, development of breast cancer and tumor responsiveness to endocrine therapies is poorly understood, the widespread expression of AR suggests that it may be of biological and clinical importance in human breast cancer.
Med Sci Monit
PMID:Androgens and androgen receptor: do they play a role in breast cancer? 1120 51

The aim of our study was to assess the antitumor effect of electrochemical therapy (ECT) in the mice bearing advanced transplantable tumours. Mouse mammary cancer 16/C (group 1) and fibrosarcoma F69-3 (group 2) were transplanted subcutaneously (s.c.) into the C3H or BALB/c mice, respectively. Twenty animals in each group bearing measurable s.c. tumours were randomly divided into two subgroups (experimental and control). Two electrodes were inserted into tumours and low level direct current (6-7 V, 5-21 mA) was passed. The animals were observed and tumors were measured twice a week. The animals were sacrificed and autopsied when the tumor diameter reached 2.0 cm. Two animals of each group (experimental and control) were sacrificed for histopathological tumor examination on the 1st and 6th day after ECT. A significant inhibition of tumor growth in mice subjected to ECT was observed, both in those with s.c. growing mammary cancer and with fibrosarcoma. This inhibition was associated with marked prolongation of survival time of ECT-treated mice. It appeared that the mice with mammary cancers were more susceptible to ECT therapy than those with growing s.c. fibrosarcoma. The histopathological studies of tumor specimens from ECT-treated mice showed extensive foci of necrosis with shrinkage of cell nuclei deprived of chromatin. In conclusion, the treatment which inhibits the growth of experimental mammary and fibrosarcoma tumors was demonstrated. However, in no mice complete regression of tumours was observed.
Med Sci Monit
PMID:Antitumor effect of electrochemical therapy on transplantable mouse cancers. 1120 60

The case of benign schwannoma of the rectum primarily misdiagnosed as myogenic (neurogenic?) sarcoma is presented. A large tumor of 8 cm in diameter of the anterior rectal wall was removed with wide margins and an artificial anus was constructed. During 12 years of follow-up neither local recurrence nor distant metastases were observed. The patient is still alive and free of the disease. For that reason a surgery specimen of the tumor was pathologically reanalyzed and it showed features of type Antoni A and B tissues. These findings, together with strong reactivity for S-100 protein, Vimentin and negative for Actin supported the diagnosis of benign schwannoma. Because the localization of the tumor in the rectum is extremely rare, clinical and pathological features are presented and discussed.
Med Sci Monit
PMID:Case report of schwannoma of the rectum--clinical and pathological contribution. 1120 9

Normal and dysplastic mammary glands express immunocompetent S-100 protein positive dendritic cells (DCs), which are located in a regular pattern, in the suprabasal cell layer of the ducts and alveolar nodules. The epithelial cells, however, are S-100 protein negative. Since some breast cancers also express the S-100 protein, our aim was to check the diagnostic and prognostic value of the S-100 protein distribution combined with the tumor grade and expression of synaptophysin (Syn), chromogranin A (Chg A), c-erbB-2 oncoprotein and p53 protein in infiltrating and metastatic breast tumors. Applying immunohistochemical methods, we show in paraffin- or frozen breast tissue sections that in some cases of the infiltrating breast carcinomas, S-100 protein positive cells do not appear, whereas in other cases, either S-100 protein positive DCs are closely associated with cancer cells, or the cancer cells themselves stain positive to S-100 protein. However, we found no correlation between the S-100 protein expression and other investigated parameters.
Med Sci Monit
PMID:Dendritic and cancer cells in the breast tumors--an immunohistochemical study: short communication. 1120 28

The article discusses the role of vascular endothelial growth factor(VEGF) in angiogenesis in embryonic development, particularly the effect of VEGF on capillary formation in response to chronic tissue ischemia and hypoxia. The sources and action of numerous angiogenic and angiostatic factors responsible for morphologic development of endothelial cells and disturbances in VEGF and FGF secretion are also presented. Increased VEGF and VEGF receptor expression enhances vascular permeability and angiogenesis, and is the cause of tissue edema as well as tumor and metastasis formation. VEGF appears to have a beneficial effect only in ischemic diseases of the heart and peripheral vessels. The article highlights the therapeutic implication of VEGF suppression in other areas of ischemia.
Med Sci Monit
PMID:Vascular endothelial growth factor (VEGF) and its effect on angiogenesis. 1120 53


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