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)

Kinetic models to describe the time course of the Ca(2+)-independent outward potassium current (Ito) in cardiac ventricular cells were constructed. The Ito traces were recorded from isolated myocytes of rats and mice using the whole-cell configuration of the patch-clamp technique. An iterative method was developed to eliminate the capacitive transient overlapping the early part of the Ito. The isolated Ito curves were then fitted by Hodgkin-Huxley type functions and different inactivation gating mechanisms were identified in various groups of the animals. In some Wistar rats a single inactivation route was found. Another group of Wistar rats and diabetic BB/Mol rats showed two independent inactivation pathways both of which resulted in a completely closed channel. In lean specimen of C-57 mice and in streptozotocin-treated Wistar rats the two inactivation gates gave closed channels only when both parallel inactivating transitions have been completed. In this case a possible interaction between the gating particles has been revealed.
 ...
PMID:Three different gating models for inactivation of the Ito in ventricular myocytes of rats and mice. 872 Jun 91

PCR product sizing on ethidium bromide-stained gels, coupled with Southern transfer and hybridization with nonisotopic probes, is an effective way of detecting t(14;18)(q32;q21). We evaluated an alternative ELISA-based test for detecting amplified t(14;18) products. Digoxigenin (DIG)-labeled dUTP is incorporated in a standard PCR method for amplification of bcl-2 major breakpoint region (mbr) rearrangements. The product is hybridized to a specific biotinylated DNA probe internal to the mbr primer, placed in streptavidin-coated wells of a microtiter plate, and detected with a alkaline phosphatase-conjugated anti-DIG antibody and enzyme substrate (pNpp). The colorimetric product is quantitated by an automated optical density (O.D.) reader. We evaluated 13 mbr-positive follicular lymphomas (FL), five mbr-negative B-cell neoplasms (BCN), 16 reactive lymphoid hyperplasias (RLH), 14 cases of Hodgkin's disease (HD), and normal peripheral blood samples from 20 healthy volunteers. All samples were evaluated in duplicate on separate plates. Positive [t(14;18)-containing cell line] and negative [cell line without t(14;18); master mix only] controls, and a standard curve were included with each run. Numerical O.D. readings from the specific hybridization assays revealed differences between FL and the other categories. All FL had an O.D. reading at > 2.0. The vast majority of RLH, HD, BCN, and normal peripheral blood samples showed O.D. readings well below 2.0. Specifically, 13/16 RLH and all HD, BCN, and normal peripheral blood samples had an O.D. of < or = 0.6 in all runs. The three outliers, which were all < 2.0, may represent the low level detection of t(14;18)-containing cells in RLH similar to previous reports. Moreover, all but four RLH had O.D. readings above the background negative controls, suggesting that rare t(14;18)-containing cells may have been present in these samples, as well. Dilution studies estimate that this assay is capable of detecting 1 t(14;18)-containing cell in approximately 10(5) cells, a greater level of sensitivity than can be obtained with gel visualization alone. We conclude that this semi-automated, potentially quantifiable ELISA-based system is a useful, objective and reproducible alternative hybridization procedure for verifying PCR product specificity in this setting.
Diagn Mol Pathol 1996 Jun
PMID:Semi-automated ELISA-based detection system for verifying the authenticity of amplified t(14;18)-containing products. 872 98

A supportive or causal role for human herpesvirus 6 (HHV-6) in lymphoproliferative disorders is still controversial. Different results were obtained in both tissue-based and serological investigations. We investigated 243 lymph node and salivary gland tissue biopsies for the presence of viral DNA by using a newly developed, highly sensitive nested polymerase chain reaction method. HHV-6 was detected in 39% of the non-Hodgkin's lymphomas, in 52% of Hodgkin's diseases, 64% of non-neoplastic lymph nodes, 23% of tumor metastases, and 50% of salivary gland biopsies. When correlating the patients' ages with the occurrence of HHV-6, we found a significantly higher percentage of positive samples in patients younger than 60 years of age (54%) than in older patients (35%). This age-related difference was found in all the lymphoproliferative disorders studied as well as in salivary gland biopsies. Taking patient's ages into account, we found no significant difference between the various groups of disorders concerning the percentage of HHV-6-positive samples.
Diagn Mol Pathol 1996 Sep
PMID:Presence of human herpesvirus type 6 in sporadic lymphoproliferative disorders. A comparative study. 886 29

B-cell non-Hodgkin's lymphomas with a marked preponderance of reactive T cells, so-called T-cell rich B-cell lymphomas (TCRBCLs), can be morphologically confused with Hodgkin's disease (HD). To establish helpful distinguishing features in paraffin sections, 10 cases of L26-positive, CD15-negative HD and 10 cases of TCRBCL were compared; 4 cases of HD had morphologic features of the nodular lymphocyte predominant (LP) type. Nine of 10 cases of HD contained fewer than 20 mitoses/20 high power fields (hpf) and only 1 had pericapsular involvement. In contrast, 9 of 10 TCRBCL had greater than 20 mitoses/20 hpf and 7 had perinodal infiltration. HDLP was easily distinguished from TCRBCL by the expanded dendritic meshworks outlining the L & H nodules and the high content of CD57-positive lymphocytes. The remaining 6 cases of non-LP L26-positive HD had a relatively distinctive immunostaining pattern, with absence of CD45 and discordant reactivity for L26 and Ki-B5 in Reed-Sternberg cells and variants. Only 3 cases of TCRBCL had a similar CD45 and L26/Ki-B5 immunostaining pattern, and these could be distinguished by demonstrable cytoplasmic light-chain restriction. These results show that evaluation of the mitotic count, pericapsular involvement, and immunohistochemical staining patterns for Ki-M4p, CD57, L26/Ki-B5, and CD45 can help to discriminate TCRBCL from L26-positive HD when only fixed material is available.
Hematopathol Mol Hematol 1996
PMID:Differential diagnosis of L26-positive, CD15-negative Hodgkin's disease and large B-cell lymphoma with a high content of reactive T-cells: a morphologic and immunohistochemical study. 887 32

Large-cell anaplastic lymphomas (LCAL) are characterized by their distinctive morphology together with expression of the CD30 antigen. In addition, a chromosomal translocation, t(2;5) (p23; q35), can be detected in most cases. A significant proportion of LCALs carry rearrangements of the T-cell receptor-gamma (TCR-gamma) locus and display a T-cell phenotype. In about a third of the cases, another type of non-Hodgkin-lymphoma precedes LCAL. Early transformations of non-Hodgkin's lymphoma into LCAL might escape clinical detection in a significant number of cases. The existence of clonally related lymphoid cells within the lymph node infiltrates must be claimed in these cases. Recently, a small-cell-predominant variant of LCAL was described in which only few large tumor cells expressing the CD30 antigen are found together with numerous small lymphocytes, which are frequently CD30-. This observation in particular prompted us to investigate the clonal relationship of the tumor cell compartment and admixed small lymphocytes in one case of common LCAL with T-cell genotype. For this purpose, we chose to amplify rearranged TCR-gamma sequences from single cells isolated from immunostained frozen sections by using a micromanipulator. A total of 119 cells were investigated. Amplification products were obtained in 17 of 79 CD3+ cells, 12 of 30 CD30+ cells, and three of 10 CD20+ cells. The nucleotide sequences were determined in 28 cells by nonradioactive sequencing. In 11 CD30+ cells, the predominant rearrangement of TCR-gamma was identified. No clonal diversity was observed. The small CD3+ lymphocytes were unrelated to the anaplastic CD30+ tumor cells. This report describes a method to analyze rearrangements of the TCR-gamma in single cells isolated from immunostained frozen sections. Application of this technique revealed an absence of clonal diversity in a case of LCAL and documented the polyclonal nature of admixed small CD3+ lymphocytes.
Diagn Mol Pathol 1996 Mar
PMID:Single-cell analysis of T-cell receptor-gamma rearrangements in large-cell anaplastic lymphoma. 891 40

The mdm-2 protein is a 90-kD protein that forms a complex with the p53 protein, enabling cells from some human neoplasms to overcome the growth-suppressing activity of p53. Most non-Hodgkin's lymphomas lack p53 mutations, and the mechanism of inactivation of tumor suppressive function remains obscure. To assess the role of mdm-2 in lymphomagenesis, 22 cases were evaluated for mdm-2 gene amplification or rearrangement in Southern blots. Localization of the mdm-2 protein was performed on cryostat sections and compared with expression of the p53 gene product. No case exhibited mdm-2 gene amplification or rearrangement, but overexpression of nuclear mdm-2 gene protein product was found in three of six diffuse large cell (B-cell immunoblastic) lymphomas (30-70% of the tumor cells stained). The mdm-2 protein was absent from low- and intermediate-grade lymphomas with the exception of a few cells (5% or less) in four cases. The mdm-2-positive cases stained negative for p53. Southern blot analysis showed that samples overexpressing mdm-2 did not have amplification or rearrangement of the gene. In summary, amplification of the mdm-2 gene does not appear to play a prominent role in the pathogenesis of non-Hodgkin's lymphomas, although overexpression of the protein gene product occurs, particularly in high-grade neoplasms.
Diagn Mol Pathol 1996 Mar
PMID:mdm-2 oncogene expression in non-Hodgkin's lymphomas. 891 43

We have adapted and developed a PCR (polymerase chain reaction)-based technique for the T-cell receptor (TCR)-gamma chain gene, which has subsequently been used for routine diagnosis. Variable-region oligonucleotide primers were chosen from subgroups I and II, and the joining region primer was from the J2 segment. The primers were used to perform a 32P-incorporation PCR, and the products were then separated on an 8% denaturing polyacrylamide gel. In our hands, this technique is more reliable than cold methods, when separation is performed on either agarose or nondenaturing polyacrylamide. The radioactive technique was used to look at 102 T-cell proliferations, of which eight of eight T-acute lymphoblastic leukemia (ALL), 24 of 34 T-non-Hodgkin's leukemia (NHL), and 35 of 60 large granular lymphocyte (LGL) expansions were clonal. Of 122 B-cell proliferations investigated, including 72 cases of B-cell lineage ALL, 36 demonstrated a T-cell rearrangement (33 ALLs and three myelomas). Samples from nonlymphoid tumors were tested and produced a normal distribution ladder of PCR products after autoradiography, a pattern also observed with antenatal and preoperative patients. The radiolabel-incorporation method detected an abnormal pattern of a ladder with prominent dark bands in 29 of 122 B-cell and 27 of 102 T-cell cases and in 0 of 49 of the nonlymphoid and normal samples. The abnormal banding patterns obtained in a proportion of the B- and T-cell cases was not readily discernible by nondenaturing-acrylamide or agarose-separation methods.
Diagn Mol Pathol 1996 Mar
PMID:32P-incorporation PCR for the detection of rearrangements at the TCR-gamma locus. 895 23

In vivo measurement of human somatic mutations may be a valuable biodosimeter of exposure to carcinogens and of cancer risk. We have surveyed translocations at the bcl2 locus in B lymphocytes, and mutations at hprt in T lymphocytes, in 120 individuals with varying exposure to radon and cigarette smoke. bcl2 t(14:18) translocation is the commonest chromosomal alteration observed in non-Hodgkins lymphoma (NHL). We observed a significantly larger range of bcl2 translocation frequency (range: 0-372 x 10(-6), median: 1.9 x 10(-6)) than of hprt mutation frequency (range: 0-76.4 x 10(-6), median: 11.1 x 10(-6)), which is likely the result of clonal proliferation of deathless B cell mutants. We observed that the frequencies of these two distinct lymphocytic mutations are significantly correlated. Although some of the correlated variation is explained by age, a significant correlation of bcl2 mutagenesis persists after age adjustment. Correlated mutagenesis at distinct loci in distinct cell types could be explained by the existence of a mutator phenotype or by variation in exposure to environmental mutagens. NHL is commoner in men than in women, and our data indicate a trend toward higher bcl2 mutagenesis in males than females. There is mounting epidemiological evidence for a worldwide increase in NHL, which may have an environmental basis; molecular epidemiological analysis of bcl2 mutagenesis in exposed populations might be especially relevant to the identification of putative environmental causes. Given the relative ease of the bcl2 assay versus the hprt assay, and the consistency with which data are reproduced from laboratory to laboratory, it is likely that the bcl2 assay will be soon added to the array of assays used in human mutational surveillance.
Environ Mol Mutagen 1997
PMID:Correlated mutagenesis of bcl2 and hprt loci in blood lymphocytes. 902 Mar 5

For DNA strand break analysis in human white blood cells, usually metrizoate-Ficoll centrifugation is used to isolate mononuclear cells. This procedure is time-consuming and requires at least 20 ml of blood per sample. Therefore, we developed a technique which does not require isolation of white blood cells prior to DNA strand break analysis by alkaline elution (direct method). The sensitivity of this new technique was compared to that of the standard method, which includes isolation of mononuclear blood cells. A statistically significant increase in sensitivity was observed using the direct method. After in vitro gamma-irradiation of venous blood, an increase in the elution rate of 7.7 x 10(-3) hr(-1)/Gy was detected if mononuclear blood cells were isolated compared to 10.5 x 10(-3) hr(-1)/Gy with the new technique (P < 0.05). Incubation of venous blood with ethylene oxide for 1 hr caused an increase in the elution rate of 5.8 x 10(-3) hr(-1)/mM ethylene oxide for the standard and 12 x 10(-3) h(-1)/mM for the direct method (P < 0.05). DNA single-strand breaks were detected in blood cells of 10 persons without any apparent genotoxic exposure. A mean normalized elution rate of 1.30 +/- 0.38 (95% confidence interval) was detected in isolated mononuclear blood cells, and a similar mean normalized elution rate of 1.41 +/- 0.50 was obtained using the direct method. The difference was not statistically significant. Five patients treated with a combination chemotherapy consisting of cyclophosphamide (750 mg/m2 i.v.), doxorubicin (50 mg/m2 i.v.), vincristine (1.4 mg/m2 i.v.), and prednisolone (100 mg/m2 p.o.) for non-Hodgkin's disease were analyzed for DNA single-strand breaks before and 16-18 hr after the application of chemotherapy. Increases in mean elution rate of 68% and 116% were detected using the standard and the direct methods, respectively. For the direct method, only 3 ml of venous blood were sufficient for analysis of one sample, compared to 25 ml needed if mononuclear cells were isolated, and about 4 hr of work per assay can be saved.
Environ Mol Mutagen 1997
PMID:Analysis of DNA single-strand breaks in human venous blood: a technique which does not require isolation of white blood cells. 902 Mar 8

CD30 is a lymphoid cell-specific surface receptor which was originally identified as an antigen expressed on Hodgkin's lymphoma cells. Activation of CD30 induces the nuclear factor kappaB (NF-kappaB) transcription factor. In this study, we define the domains in CD30 which are required for NF-kappaB activation. Two separate elements of the cytoplasmic domain which were capable of inducing NF-kappaB independently of one another were identified. The first domain (domain 1) mapped to a approximately 120-amino-acid sequence in the membrane-proximal region of the CD30 cytoplasmic tail, between residues 410 and 531. A second, more carboxy-terminal region (domain 2) was identified between residues 553 and 595. Domain 2 contains two 5- to 10-amino-acid elements which can mediate the binding of CD30 to members of the tumor necrosis factor receptor-associated factor (TRAF) family of signal transducing proteins. Coexpression of CD30 with TRAF1 or TRAF2 but not TRAF3 augmented NF-kappaB activation through domain 2 but not domain 1. NF-kappaB induction through domain 2 was inhibited by coexpression of either full-length TRAF3 or dominant negative forms of TRAF1 or TRAF2. In contrast, NF-kappaB induction by domain 1 was not affected by alterations in TRAF protein levels. Together, these data support a model in which CD30 can induce NF-kappaB by both TRAF-dependent and -independent mechanisms. TRAF-dependent induction of NF-kappaB appears to be regulated by the relative levels of individual TRAF proteins in the cell.
Mol Cell Biol 1997 Mar
PMID:Induction of nuclear factor kappaB by the CD30 receptor is mediated by TRAF1 and TRAF2. 903 81


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