Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We report on two assays for autoantibodies to the TSH-R which have been developed using materials from mammalian cells transfected with the cDNA for the human TSH-R. In the first, a particulate fraction has been prepared from COS cells, transiently expressing the human TSH-R and used in a radioreceptor assay in conjunction with bovine 125I-TSH. Immunoglobulins (IgGs) from patients with Graves' disease (n = 11) and idiopathic myxoedema (n = 2) have been used as competitors of 125I-TSH binding to the COS TSH-R membranes and the results have been compared with those obtained with a commercially available kit for measuring TSH-R autoantibodies, which uses solubilised porcine TSH-R. Both assays showed similar performance, being particularly sensitive to antibodies from patients with idiopathic myxoedema. In the second assay system we have used a CHO cloned cell line (JP26) stably transfected with the human TSH-R. A selection of IgG preparations from patients with Graves' disease and of six normal controls was used to test the ability of this cell line to detect thyroid stimulating immunoglobulins (TSAb) by increasing its cAMP production. The assay was performed under two conditions: in standard (isotonic) medium or in hypotonic medium. Freshly thawed human thyrocytes incubated in hypotonic medium served as a reference method. Only five patients scored positive when tested in the JP26 cell line under isotonic conditions. When the assay was performed in a hypotonic medium, a significant positive correlation was observed between the results given by JP26 cells and human thyrocytes.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1990 Oct 01
PMID:Use of the recombinant human thyrotropin receptor (TSH-R) expressed in mammalian cell lines to assay TSH-R autoantibodies. 198 64

The limits of detection of 10 genotoxins representing 7 chemical classes with varying structures and modes of action were compared using the Ames test (Salmonella plate-incorporation test) with 2 tester strains, 2 standard colorimetric methods (the umu test and SOS Chromotest), and modifications of the umu and SOS Chromotests developed during the course of this study. The purpose of the study was to determine the sensitivity and reproducibility of each of the six methods. The sensitivities of the methods were compared using two criteria: the concentrations required for doubling responses, and the minimum concentrations required to produce statistically significant increases from background controls. The Ames test with strains TA98 and TA100 was ranked as the most sensitive method more often than the others, but the results indicated that the umu tests were statistically equivalent to the Ames test. The original SOS Chromotest kit method was highly sensitive in detecting the direct acting genotoxins, but neither SOS test was as sensitive as the other methods in detecting indirect acting genotoxins. The umu microtiter plate test is the least expensive of the assays and would be the most suitable for screening large numbers of environmental samples.
Environ Mol Mutagen 1990
PMID:Comparison of the Salmonella (Ames) test, umu tests, and the SOS Chromotests for detecting genotoxins. 220 76

The use of different techniques for assay of oestrogen receptors (ER) in breast cancer raises the question of their relative effectiveness in measuring concentrations of functional receptors. Data were obtained on soluble receptors from supernatants from 58 primary breast tumour homogenates, using the ligand ([3H]oestradiol) binding assay with dextran-coated charcoal (DCC) separation, either at a single saturating ligand dose, or by Scatchard analysis, and by using the Abbott enzyme immunoassay (EIA) kit. As previous reports have shown, the two methods gave reasonably good correlation (r = 0.8), but EIA values were systematically higher than DCC (slope = 3.0). Similar values were obtained when the ER + ve/progesterone receptor (PR) + ve subgroup were examined separately (n = 34, r = 0.86, slope = 3.0). However the two sets of data were in much better agreement in the ER + ve/PR - ve subgroup (n = 10, r = 0.98, slope = 1.24). When analysed by isoelectric focusing on polyacrylamide gels (IEF), two major specific binding components were identified, at pI 6.1 and at pI 6.6. Both isoforms were present in 50/66 ER + ve PR + ve breast tumour samples, but only the pI 6.6 (4S) was present in most ER + ve/PR - ve samples (13/20). It appears that, compared with DCC, the EIA method gives much higher values for the 8S isoform, whereas the two methods detect the 4S isoform with similar sensitivity. In assays on the tumour cell lines, T47D and MCF-7, still greater discrepancies, at least 10-fold, were found between EIA and DCC data.
J Steroid Biochem Mol Biol 1990 Dec 10
PMID:Discrepancies between antibody (EIA) and saturation analysis of oestrogen receptor content in breast tumour samples. 227 49

DNA probes specific for C. jejuni (pDT1720 containing a 1475 base pair fragment) and for C. jejuni and C. coli (pDT1719 containing a 1845 base pair fragment) were isolated from a bacteriophage lambda gt11 genomic library of C. jejuni, using antiserum prepared against a 46 kDa major outer membrane protein of C. jejuni. The two probe-fragments had different restriction maps and were only moderately related by DNA hybridization analysis. A non-radioactive labelling kit which consisted of alkaline phosphatase conjugated anti-digoxigenin antiserum and 5-bromo-4-chloro-3-indoyl phosphate with nitroblue tetrazolium as the colour substrate, which gives a purple colour for positive hybridization, was used to test 140 stool specimens, 70 of which were culture positive and 70 of which wer culture negative for Campylobacter spp. The pDT1720 fragment (C. jejuni probe) could detect a minimum of 1 x 10(5) C. jejuni cells on filters, whereas the pDT1719 fragment (C. coli probe) was 100-fold less sensitive. The C. jejuni probe demonstrated a sensitivity of 93% with culture positive stool samples, however, 15% of culture negative samples were also recorded as positive using this non-radioactive DNA probe.
Mol Cell Probes 1990 Aug
PMID:Use of non-radioactive DNA probes for detection of Campylobacter jejuni and Campylobacter coli in stool specimens. 240 49

The proto-oncogene c-kit encodes a transmembrane kinase which is related to the receptors for colony-stimulating factor type 1 and platelet-derived growth factor, as well as to the immunoglobulin superfamily. Antibodies specific for the kinase domain of the P80 gag-kit protein of the Hardy-Zuckerman 4 feline sarcoma virus were prepared. These kit-specific antibodies were used to identify and characterize the c-kit protein in cat brain tissue. The c-kit protein product displays an autophosphorylating activity in immune complex kinase assays, and, in turn, this activity was used to identify the c-kit protein in different tissues. In cat brain, a single 145-kilodalton (kDa) glycoprotein was detected. Its N-linked carbohydrates were found to be sensitive to digestion with the endoglycosidases (neuraminidase, endoglycosidase F, and endoglycosidase H), indicating hybrid and/or complex and high-mannose structures. A partial purification of the c-kit protein was achieved by wheat germ agglutinin affinity chromatography, and the autophosphorylating activity of the partially purified c-kit protein was characterized and found to be specific for tyrosine. The kit antibodies cross-react with the murine c-kit protein product, and variant c-kit proteins in different mouse tissues were identified, with sizes of about 145 kDa (brain), 160 kDa (spleen), and 150 kDa (testis).
Mol Cell Biol 1988 Nov
PMID:c-kit protein, a transmembrane kinase: identification in tissues and characterization. 246 68

In an attempt to clone protein tyrosine kinases, antiphosphotyrosine antibodies were used to screen lambda gt11 cDNA expression libraries. By this method, a 2.5-kilobase cDNA encoding a novel tyrosine kinase was isolated from a mouse liver cDNA library. This new gene is most closely related to the receptor tyrosine kinases ret, fms, and kit.
Mol Cell Biol 1988 Dec
PMID:Novel tyrosine kinase identified by phosphotyrosine antibody screening of cDNA libraries. 246 99

We have analyzed the chromatin assembly reaction catalyzed by the Xenopus oocyte extract (S-150). A 50 S complex is formed upon mixing the 17 S pUC DNA and the S-150. Mature histones are not detected in this complex, which contains relaxed DNA and protein, and generates subnucleosomal 7 S particles upon digestion with micrococcal nuclease. The relaxed nucleoprotein is gradually supercoiled into nucleosomal chromatin in the S-150, via a pathway that requires ATP and is blocked by novobiocin, and this process is accompanied by the appearance of mature histones H3 and H4. Isolated complexes also supercoil in vitro, which implies the complex is a kit that contains histone precursors, as well as topoisomerases and other enzymes required for assembly. We discuss the biological implications of these findings.
J Mol Biol 1986 Jun 05
PMID:Mechanism of chromatin assembly in Xenopus oocytes. 378 82

Machine learning methods are becoming accepted as additions to the biologists data-analysis tool kit. However, scaling these techniques up to large data sets, such as those in biological and medical domains, is problematic in terms of both the required computational search effort and required memory (and the detrimental effects of excessive swapping). Our approach to tackling the problem of scaling up to large datasets is to take advantage of the ubiquitous workstation networks that are generally available in scientific and engineering environments. This paper introduces the notion of the invariant-partitioning property--that for certain evaluation criteria it is possible to partition a data set across multiple processors such that any rule that is satisfactory over the entire data set will also be satisfactory on at least one subset. In addition, by taking advantage of cooperation through interprocess communication, it is possible to build distributed learning algorithms such that only rules that are satisfactory over the entire data set will be learned. We describe a distributed learning system, CorPRL, that takes advantage of the invariant-partitioning property to learn from very large data sets, and present results demonstrating CorPRL's effectiveness in analyzing data from two databases.
Proc Int Conf Intell Syst Mol Biol 1994
PMID:Distributed machine learning: scaling up with coarse-grained parallelism. 758 10

We evaluated the presence and variability of oestrogen receptor (ER) isoforms in endometrial cancer by using [3H]oestradiol-labelled ERs and the H222 monoclonal antibody obtained from the Abbott enzyme immunoassay kit. Using isoelectric focusing (IEF), endometrial ER was shown to be composed of four different species, with pI values of 6.1, 6.3, 6.6 and 6.8, indistinguishable from the isoforms found in normal rat uterus, and human breast and larynx carcinomas. The isoforms at pI 6.3, 6.6 and 6.8, all sedimenting at 4S by sucrose gradient fractionation, showed, on two-dimensional SDS electrophoresis, relative masses of 50, 70 and 65 kDa respectively, equal to the masses previously found in breast cancer. These isoforms did not alter their pI values during IEF fractionation performed in a linear gradient of urea, while the pI 6.1, sedimenting at 8S, generated a new isoform at about 9 mol/l urea with pI 7.2 and a relative mass of 65 kDa. The urea-dissociated isoform (pI 7.2) was able approximately to double the antibody binding with respect to the nondissociated oligomer, which suggested that some epitopes are 'masked', i.e. not accessible to the antibodies when ER is present in its complexed form. The evidence thus suggested that the oligomer at pI 6.1 contained a single 65 kDa ER form which, as a monomer, focused at pI 7.2. The variability in the ER isoform profile found in endometrial cancer was similar to the variability previously reported in breast and larynx carcinomas. The balance between these isoforms could be a dynamic parameter involved in the functionality of this receptor and consequently in cell transformation.
J Mol Endocrinol 1995 Jun
PMID:Multiple isoforms of the oestrogen receptor in endometrial cancer. 766 26

The extracellular portion of the kit-encoded receptor for the stem cell factor (SCF) comprises five immunoglobulin (Ig)-like domains. To localize the ligand recognition site, we exploited the lack of binding of human SCF to the murine receptor by using human-mouse hybrids of Kit and species-specific monoclonal antibodies (MAbs) that inhibit ligand binding. Replacement of the three N-terminal Ig-like domains of the murine Kit with the corresponding portion of the human receptor conferred upon the chimeric receptor high-affinity binding of the human ligand as well as of human-specific ligand-inhibitory MAbs. By constructing five chimeric murine Kit proteins which individually contain each of these three human Ig-like units or pairs of them, we found that the second human domain confers upon the mouse Kit high-affinity binding of the human ligand and also binding of species-specific SCF-competitive MAbs. Nevertheless, the flanking Ig-like domains also affect high-affinity recognition of SCF. Moreover, it appears that the determinants that define ligand specificity of the murine and the human receptors do not structurally coincide. This observation allowed us to identify a chimeric receptor that displayed a dual specificity; namely, it bound with high affinity either the human or the murine SCF molecules and reacted with mouse- as well as human-specific ligand-inhibitory MAbs. Conversely, another chimera, which included all of the five Ig-like domains, bound neither ligand. In conclusion, interdomain packing involving the second Ig-like domain of human Kit and noncontiguous structural motifs of the receptor are involved in SCF recognition.
Mol Cell Biol 1993 Apr
PMID:Interspecies molecular chimeras of kit help define the binding site of the stem cell factor. 768 Nov 44


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