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)

We studied several monoclonal antibodies (mAbs) raised against the 100 kD Ras GTPase activating protein (p100-GAP), which was purified from human placenta. These antibodies recognized p120-GAP and p100-GAP in native and in denatured forms. The most reactive, GP15 and GP200, both recognized distinct epitopes and did not neutralize GTPase stimulatory activity. These two mAbs were selected for a two-site enzyme immunoassay, using covalent conjugates of the antibodies coupled to the tetrameric form of acetylcholinesterase as tracer. This assay was used to quantify Ras-GAP in both normal and tumor tissues and cell extracts.
 ...
PMID:Non-neutralizing monoclonal antibodies against Ras GTPase-activating protein: production, characterization and use in an enzyme immunometric assay. 136 95

A 40-year-old white woman underwent amniocentesis for advanced maternal age at 15.4 weeks gestation. Fetal chromosome analysis demonstrated two distinct cell lines: [46,XX,t(1;19)(p11;p11)]--10%; and [47,XX,t(1;19)(p11;p11) + der(1)t(1;19)(p11;q11)]--90%. The latter karyotype was trisomic for both 1q and 19p. The mother carried the balanced translocation; the father had a normal karyotype. Amniotic fluid alpha-fetoprotein level was elevated and an acetylcholinesterase band was detected. Level II ultrasonography at 17 and 24 weeks revealed several abnormalities, including a large facial cleft and a probable facial teratoma and intracranial tumor. Autopsy following pregnancy termination confirmed the presence of both. Chromosome evaluation of 172 metaphases of both the epignathus and the intracranial teratoma demonstrated a predominance of the cell line with 47 chromosomes (166/172 = 96.5%), while from nonteratoma tissue (lung, liver, skin, and brain) only the balanced karyotype was detected. These observations suggest that the chromosomal imbalance is instrumental in the etiology of the teratoma.
 ...
PMID:An unusual mosaic karyotype detected through prenatal diagnosis with duplication of 1q and 19p and associated teratoma development. 138 56

In vitro, we were able to induce a differentiation of human (SK-N-MC, IMR-32, Leo-2) and murine neuroblastoma cells (NA-2, C-1300, NIE-115) with dibutyryl cyclic 3'5'-adenosine monophosphate (dbcAMP), hypothalamic factor (HF), and somatostatin. As morphological criteria of cellular differentiation we used the decrease in cell proliferation and the formation of neurites. Functional parameters were the increase of A cholinesterase activity, cAMP level, and protein content, and the decrease of cGMP level. After application of dbcAMP and HF, the effects were stronger than after somatostatin. We believe that the action of HF and somatostatin is caused by an increase in cAMP levels. In the in vivo experiments, human and murine neuroblastoma cells (NA-2, C-1300, and Leo-2) were transplanted into nude/nude mice. After HF treatment of 14 mice with NA-2 tumors, 4 of the mice were tumor-free, and mean tumor weight was reduced to one-third of the controls. Of the animals with C-1300 and Leo-2 tumors, half became tumor-free, and mean tumor weight was reduced to one-fourth. The results indicate that the induction of cellular differentiation by factors and hormones may in future become a method of therapy for human neuroblastoma.
 ...
PMID:Research on the differentiation of human and murine neuroblastoma cells. 167 82

We have examined the distribution of probable cholinergic nerves in the human adrenal cortex using acetylcholinesterase (AChE) histochemistry. Adrenal tissue was obtained from three subjects during therapeutic radical nephrectomy for renal neoplastic disease. Light microscopy revealed a heterogeneous pattern of cortical innervation, with nerves most abundant in the head and body and largely absent from the tail. There was frequently a subcapsular plexus of interwoven AChE + ve nerve trunks in close relationship to densely stained (ganglion) cells. Nerves also traversed the zona fasciculata in radial trunks and a further plexus with ganglion cells was observed in the zona reticularis. Nerve trunks were seen to penetrate the medulla. Some nerve trunks appeared to terminate or branch or form individual nerve fibres (often with varicosities) which ramified through the cortical parenchyma. In the medulla, a generalised granular staining was superimposed on nerve trunks which were branched and interwoven to form a plexus around ganglion cells. The presence and distribution of AChE + ve nerve plexuses and varicose nerve fibres is suggestive of a functional intrinsic, probably cholinergic, innervation to the human adrenal cortex, perhaps derived from the splanchnic nerves.
 ...
PMID:A preliminary study of acetylcholinesterase-positive innervation in the human adrenal cortex. 171 21

THA (Tacrine), a drug used in the experimental therapy of dementia of Alzheimer's disease type, and whose biochemical site of action is believed to be the neural cholinesterase, is shown, for the first time, to be an immunosuppressant in vitro on normal human peripheral blood lymphocytes in microgram quantities. THA down-regulates non-MHC restricted natural killer (NK) cell activity without affecting the general viability of cells. This down-regulation can be demonstrated at all effector and target (K562) concentrations, in purified resting NK cells as well as in lymphokine (interleukin 2) activated killer cells in 3- or 16-h NK assays and in all the blood samples tested. Kinetic analysis shows that the Vmax (maximal cytotoxic potential) and Km of NK cell-mediated cytolysis are also attenuated. Single cell assays using agarose matrix reveal that THA moderately interferes with tumor target binding/recognition events and strongly abrogates the delivery of lethal hit, thus lowering the frequency of active killer cells among THA-treated lymphocytes. THA down-regulates NK cells upon direct interaction and does not require the help of non-NK cells. The THA sensitive site(s) on NK cells does not appear to be perturbed significantly either by their proliferative status or by membrane modulations that may be normally induced by interleukin 2. The in vitro immunomodulatory pharmacological properties of THA reveal that the biological site of action of THA extends to non-neural cells also. Such non-neural models may be helpful in exploring the pathophysiological neuroimmunomodulatory properties of THA at cellular and molecular levels.
 ...
PMID:Immunomodulation by 9-amino-1,2,3,4-tetrahydroacridine (THA): 1. Down-regulation of natural cell-mediated cytotoxicity in vitro. 176 1

Hydrolysis of the neurotransmitter acetylcholine by acetylcholinesterase (ACHE) and butyrylcholinesterase (BCHE) is the rate-limiting step in the termination of cholinergic signaling at neuromuscular junctions. A growing body of evidence suggests that these enzymes also play a role in tumorigenesis. The ACHE and BCHE genes are amplified, mutated, and/or aberrantly expressed in a variety of human tumor types. These changes could be the result of chromosome breakage, since there is an unusually high frequency of chromosomal abnormalities near the map positions of these genes (3q26-ter and 11p-ter, respectively) in such tumors, particularly hemopoietic malignancies. Both ACHE and BCHE contain the consensus peptide motif S/T-P-X-Z, which is found in many substrates of cdc2-related protein kinases. Here we consider the intriguing possibility that phosphorylation by cdc2-related kinases may be the molecular mechanism linking cholinesterases with tumor cell proliferation. We also discuss the notion that inhibition of these enzymes by commonly used organophosphorous poisons may be tumorigenic in humans.
 ...
PMID:A role for cholinesterases in tumorigenesis? 182 94

Dichlorvos (dichlorovinyl dimethyl phosphoric acid ester) is a cholinesterase inhibitor used widely as a contact and stomach insecticide for control of internal and external parasites. Carcinogenesis studies were conducted by administering dichlorvos in corn oil by gavage 5 times a week for 103 weeks to groups of 50 male and 50 female Fischer rats at 0, 4, or 8 mg/kg body weight, to groups of 50 male B6C3F1 mice at 0, 10, or 20 mg/kg, and to groups of 50 female B6C3F1 mice at 0, 20, or 40 mg/kg. During the course of the studies, body weights and survival rates of the male and female rats and mice were not different from those of their respective controls; females of both species appeared to gain more weight than controls. Neoplasms induced by dichlorvos included adenomas of the exocrine pancreas (male rats), mononuclear cell leukemia (male rats), and squamous cell papilloma of the forestomach (male and female mice; two other female mice had squamous cell carcinomas). Lesions observed in female rats that may have been due to dichlorvos administration included adenomas of the exocrine pancreas and fibroadenomas of the mammary gland. The results demonstrated that dichlorvos is carcinogenic for Fischer rats and B6C3F1 mice.
 ...
PMID:Carcinogenesis studies of dichlorvos in Fischer rats and B6C3F1 mice. 190 Aug 19

A new human neuroblastoma cell line (LS) that originated from an abdominal tumor of a 16-month-old girl is presented; it was classified, according to Evans, as being stage III. Morphological (dense-core particles) and biochemical characteristics (dopamine-beta-hydroxylase, acetylcholinesterase, neuron-specific-enolase) confirmed the diagnosis. In addition to a slightly variable modal chromosome number of 48 or 49 (because of marker-chromosomes and autosomal trisomies), cytogenetic analysis revealed two constantly appearing chromosomes with homogeneously stained regions (HSR's). The karyotype remained constant over 50 passages in vitro [49,XX, -12, +der5, + 17, + mar1, + mar2]. Double minutes were a rare phenomenon and appeared only in a few metaphases. In situ hybridization showed that some of the HSR's consisted of amplified N-myc copies. The distribution of the N-myc copies according to in situ hybridization signals along the HSR's was compared with the data of Southern and Northern blotting analyses.
 ...
PMID:Cytogenetic and molecular characterization of a newly established neuroblastoma cell line LS. 202 21

Recent studies suggest that the nature of events leading to the formation, maintenance, and elimination of synapses may be regulated by cascade-type, locally expressed proteases and protease inhibitors acting on adhesive extracellular matrix components. We have identified a molecule in conditioned medium of murine skeletal muscle cells that in molecular weight, target protease inhibition, heparin-binding and cross-reactivity with authenic antisera is similar to the human serine proteinase inhibitor, protease nexin I. Protease nexin I is a 43-50 kDa glycoprotein of the serpin superfamily (arg-serpin class). Purified anti-protease nexin I antibody (anti-47 kDa) stains adult mouse skeletal muscle in discrete foci that precisely superimpose on synaptic neuromuscular junctions. Protease nexin I appears in patches on surfaces of cultured mouse skeletal myotubes, but not on myoblasts. These patches co-localize with acetylcholine receptor clusters and acetylcholinesterase staining during cellular maturation in culture. Evidence that protease nexin I is a synaptic, extracellular antigen is particularly intriguing since it has been shown to be identical, in structure and activity, with a factor released by glial cells, called glia-derived nexin that stimulates mouse neuroblastoma cell neurite outgrowth and inhibits granule cell migration. Protease nexin I inhibits both tumor cell and myoblast plasminogen activator-mediated destruction of extracellular matrix. Thus, such observations as presented in this report provide further evidence for involvement of cascade proteolytic systems, and their post-translational regulation by specific serpins, in the remodeling that occurs in synapse formation and elimination.
 ...
PMID:Plasminogen activators and inhibitors in the neuromuscular system: III. The serpin protease nexin I is synthesized by muscle and localized at neuromuscular synapses. 203 25

The authors reviewed the clinical charts and the radiographic files of 93 patients with obstructive jaundice--in 86 cases due to neoplasm--treated with PTBD. The test of differences from survival curves was used to identify the clinical parameters predictive of short survival after PTBD. The difference in survival curves was significant relative to serum indirect bilirubin (cut point: 7.6 mg%), to serum cholinesterase (cut point: 1290 mU/ml), to white blood cell counts (cut point: 8600/mm3), to blood urea nitrogen (BUN) levels (cut point: 60 mg%). Because of the marked negative prognostic value of high BUN levels, our data seem to indicate that PTBD should not be performed when severe renal insufficiency is present. Other parameters correlated with a short survival after PTBD were the histotype of metastasis (in comparison with the other ones), and large neoplastic volume (in comparison with a small and a medium ones). Through pre-PTBD radiological and laboratory data analysis, a group of patients can be selected in whom the procedure will increase neither well-being nor survival, as plotted against those patients who are likely to benefit from biliary drainage.
 ...
PMID:[Prognostic factors after percutaneous transhepatic biliary drainage]. 205 99


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