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S N Thibodeau

Publications and source records attributed to S N Thibodeau.

At least 145 records · Page 8Linked to original sources
PubMed1990

Primary splenic lymphocyte-depletion Hodgkin's disease.

A case of lymphocyte-depletion Hodgkin's disease is described for the purpose of reviewing the criteria currently used to distinguish this disease from other pleomorphic large-cell malignancies. A 76-year-old man with a 3-month history of daily fevers underwent extensive evaluation and exploratory laparotomy, which revealed only two large, separate splenic tumor nodules. Postoperatively, the patient remained asymptomatic. Histologically, the tumor was composed of giant cells, including both typical Reed-Sternberg forms and mononuclear variants with inflammatory stromal response along its borders. Immunoperoxidase showed tumor cells to be strongly reactive for Leu-M1 (CD15), BER-H2 (CD30), Leu-3 (CD4), and T11 (CD2) and weakly reactive for Leu-4 (CD3) but nonreactive for EMA, LCA, lysozyme, Leu-9, Leu-M3, Leu-M5, and immunoglobulin light chains. Southern blot analysis revealed an isolated clonal band for kappa light chain only. Included in the discussion of this case of primary splenic lymphocyte-depletion Hodgkin's disease is a review of clinical, histologic, immunohistochemical, and gene-rearrangement characteristics of what can be defined as lymphocyte-depletion Hodgkin's disease.

Aged↗
PubMed1990

The location of the Philadelphia chromosomal breakpoint site and prognosis in chronic granulocytic leukemia.

Chronic granulocytic leukemia (CGL) is associated with a reciprocal translocation between chromosomes 9 and 22. The breakpoint sites on chromosome 22 are clustered in a limited region known as the major breakpoint cluster region (Mbcr). This region is approximately 5.8 Kb long and can be arbitrarily subdivided into five zones (1 through 5 from the 5' towards the 3' end) as defined by the particular sites of three restriction endonucleases. Using Southern blot analysis with two DNA probes, one spanning both the 5' and 3' regions of the Mbcr while the other only the 3' region, we mapped the precise location of the chromosomal breakpoints within the Mbcr in 62 patients with CGL and examined possible clinical correlations. There were 39 patients with 5' breakpoints (zones 1-3) and 23 patients with 3' breakpoints (zones 4 and 5). We found no correlation between the clinical phase of the disease at last followup and breakpoint distributions. The distributions of chronic phase duration (CPD) and survival were similar between patients with 5' breakpoints (median CPD = 4.0 years) and those with 3' breakpoints (median CPD = 5.2 years). Presenting clinical features and the rates of lymphoblastic transformation were also similar among the subgroups. Our data suggest that the precise location of the breakpoint within the Mbcr in CGL may not have clinical relevance.

Blast Crisis↗
PubMed1989

Genetic and physical mapping of a novel region close to the fragile X site on the human X chromosome.

We report the isolation and characterization of a novel DNA marker (1A1) in Xqter in the region of the fragile X. Genetic studies in families segregating for the fragile X syndrome suggest that 1A1 lies between the disease mutation and the distal locus, DXS52. Studies in normal and fragile X families show that 1A1 is tightly linked to DXS52 (Zmax = 17.20; theta max = 0.03) and F8 (Zmax = 7.01; theta max = 0.08). Multipoint mapping of families supports the order Xcen-DXS105-FRAXA-1A1-DXS52-(F8, DXS115)-Xqter. Pulsed-field gel electrophoresis (PFGE) studies demonstrate that 1A1 defines a new region of at least 2 Mb of DNA not physically linked to DXS52 or F8, thus extending the physical map of Xq27-qter to over 4 Mb. Complex partial digestion PFGE patterns, probably due to differing degrees of methylation, are observed with 1A1 in unrelated normal and fragile-X-positive individuals, whereas other distal markers give uniform digestion profiles. Physical data suggest that 1A1 lies in a region less CpG rich than other distal markers in Xq27-qter.

Animals↗
PubMed1989

Carrier identification of cystic fibrosis by recombinant DNA techniques.

As a result of recent advances in molecular genetics, carrier testing for cystic fibrosis (CF) is now available as a clinical assay in a limited number of laboratories. Because neither the gene nor the mutation for this disorder has yet been defined, the analysis relies on an indirect approach that uses DNA sequence polymorphisms and linkage analysis. With use of this general approach, several family members, in addition to those persons seeking carrier information, must be tested. Currently, more than 97% of families are "fully informative" when these markers are used in a linkage analysis; thus, the carrier status of most persons who have a relative with CF can be determined. Recently, strong linkage disequilibrium has been shown between two polymorphic loci (defined by the DNA probes KM.19 and XV-2c) and the CF locus. Because of this important finding, haplotype testing can be used in many clinical settings, such as for families in which a DNA sample is not available from the affected person or for those families in which one spouse has no family history of CF and the other is either affected or is at a high risk of carrying the CF mutation. Overall, the application of recombinant DNA techniques has greatly enhanced the ability to determine, with a high level of accuracy, the carrier status of those persons at risk for inheriting the CF mutation.

Cystic Fibrosis↗
PubMed1988

Linkage analysis using multiple DNA polymorphic markers in normal families and in families with fragile X syndrome.

Linkage data, using the polymorphic markers 52A (DXS51), F9, 4D-8 (DXS98), and St14 (DXS52), are presented from 14 fragile X pedigrees and from 7 normal pedigrees derived from the collection of the Centre d'Etude du Polymorphisme Humaine. A multipoint linkage analysis indicates that the most probable order of these four loci in normal families is DXS51-F9-DXS98-DXS52. Recombination frequencies (theta) corresponding to maximum LOD scores (Z) were obtained by two-point linkage analysis for a number of linkage groups, including: DXS51-F9 (Z = 5.94, theta = 0.03), F9-DXS98 (Z = 0.51, theta = 0.26), F9-DXS52 (Z = 0.84, theta = 0.27), and DXS98-DXS52 (Z = 0.32, theta = 0.20). A multipoint linkage analysis of these loci, including the fragile X locus, was also performed for the fragile X population and the data support the relative order (DSX51, F9, DXS98)-FRAXA-DXS52. Recombination frequencies and maximum LOD scores, which again were derived from two-point linkage analyses, were obtained for the linkage groups DXS51-F9 (Z = 9.96, theta = 0) and F9-DXS52 (Z = 0.07, theta = 0.45) as well as for the groups DXS51-FRAXA (Z = 2.42, theta = 0.15), F9-FRAXA (Z = 1.30, theta = 0.18), DXS98-FRAXA (Z = 0.05, theta = 0.36), and DXS52-FRAXA (Z = 2.42, theta = 0.15). The linkage data was further tested for the presence of genetic heterogeneity both within and between the fragile X and normal families for the intervals DXS51-F9, F9-DXS52, F9-FRAXA, and DXS52-FRAXA using a modification of the A test. Except for the interval F9-FRAXA (P less than 0.10) there was no evidence of genetic heterogeneity for each of the various linkage groups examined. The heterogeneity detected for the interval F9-FRAXA, however, was most likely due to one family (Fx-28) that displayed very tight linkage between these two loci.

Cells, Cultured↗
PubMed1987

Use of restriction fragment length polymorphism analysis for detecting carriers of "fragile X" syndrome.

Recombinant DNA technology promises to play an increasingly important role in the future of medicine. Application of this technology to the study of human disease will help us to define and clarify the molecular pathology of many clinical disorders, provide new diagnostic tools and approaches, and, finally, will provide new therapeutic agents including gene-replacement therapy. We have begun to exploit these powerful new techniques to aid in the laboratory diagnosis of several genetic disorders for which reliable assays are currently not available, such as "Fragile X" syndrome.

Chromosome Banding↗
PubMed1987

Carrier testing in hemophilia B with an immunoassay that distinguishes a prevalent factor IX dimorphism.

Immunoassays with a monoclonal antibody (A-1) detect a prevalent dimorphism in plasma coagulation factor IX. The antibody was shown to react with a dimorphic segment of the normal factor IX sequence as follows. First, A-1 bound to isolated activation peptide (residues 146 through 180) prepared from activated factor IX from a normal plasma pool. Second, binding of recombinant factor IXs with A-1 or factor IX from normal individuals was strong only when they had Threonine (Thr) at position 148; factor IXs with the Alanine (Ala) allele at that position were far less reactive. Third, immunoblot reactivity of Escherichia coli fusion proteins containing known segments of the factor IX sequence restricted the epitope to residues 147 through 153. In 120 hemophilia B pedigrees, the Ala immunoassay allele frequency was 0.19 and did not differ from the Ala frequency in normal males. In 22 of 49 families, immunoassay testing was informative for classification of obligate or possible carriers. In one large family, 4 obligate carriers were heterozygous for the dimorphism and 3 of their 7 daughters were classified as carriers. In other families, when the affected member had less than 1 nmol/L factor IX antigen, heterozygosity for Thr/Ala alleles excluded the carrier state even when DNA studies were not informative. Strong linkage disequilibrium of Thr/Ala alleles with the common TaqI DNA polymorphism was found. Nineteen of 75 normal and hemophilic factor IX genes had the 1.3-kilobase (kb) fragment and coded for the Ala allele; the rest had the 1.8-kb fragment and coded for Thr. In selected families, the A-1 immunoassay is an inexpensive and rapid method to confirm and supplement restriction fragment length polymorphism analyses of DNA for carrier testing.

Alleles↗
PubMed1983

Analysis of the estrogen receptor from human uterus and breast tumor tissue by isoelectric focusing.

Cytosolic estrogen receptors from human breast carcinoma (approximately 50 patients) and uterine myometrium tissue (approximately 20 patients) were analyzed by isoelectric focusing on agarose gels, by their ability to bind to isolated nuclei, and by ultracentrifugation, under diverse conditions. Through the use of diisopropylfluorophosphate (DFP) and sodium molybdate (Mo), two in vitro processes were examined by these techniques: receptor activation and receptor degradation. These agents are capable of inhibiting these processes selectively so that the resulting stabilized forms of the estrogen receptor can be characterized in more detail. The predominant molecular forms, as determined by the parameters stated above, vary dramatically depending on the presence of DFP or Mo. At least six distinct species of the estrogen receptor were resolved by isoelectric focusing. Of these, four appear to be products of proteolysis. These had isoelectric points of 6.9, 6.8, 6.4, and 6.3, with a combined sedimentation coefficient of approximately 3.2S. The nonactivated form of the receptor, prepared in the presence of both DFP and Mo, focused at pH 4.8 and had a sedimentation coefficient of approximately 9.5S. Finally, the activated form detected in the presence of DFP sedimented at 8.0S and had an apparent pI of 5.4.

Breast Neoplasms↗
PubMed1981

Simultaneous measurement of estrogen and progesterone receptors in tumor cytosols with use of 125I-labeled estradiol and of 3H-R5020.

We describe a dual-isotope assay for measuring the concentration of estrogen receptors and progesterone receptors in tumor cytosols. The concentrations of these receptors are derived from separate Scatchard-plot analyses of a single dextran-coated charcoal assay that incorporates both radioiodinated estradiol and tritiated R5020 as the labeled ligands. The two isotopes, radioiodine and tritium, are easily measured with a liquid-scintillation counter. The concentrations of estrogen and progesterone receptors derived from the dual-label assay are identical to values derived from the respective single-label assays. Moreover, values obtained from an assay with dextran-coated charcoal that incorporates radioiodinated estradiol are identical to those obtained from an assay in which tritiated estradiol is used as the labeled ligand. The dual-isotope assay requires both less time and less tissue.

Breast Neoplasms↗
PubMed1980

Processing of precursor proteins by preparations of oviduct microsomes.

The signal peptidases from both chicken oviduct and dog pancreas microsomes have been detected by a post-translational assay and, in the case of dog microsomes, by a cotranslational assay. This proteolytic activity is not sensitive to a variety of conventional protease inhibitors under the conditions used in these assays. Using a synthetic ester substrate, two additional activities have been observed in oviduct microsomes, but neither appears to correspond to the signal peptidase activity. Using cDNA as a probe for specific mRNAs, it was shown that polysomes, in the process of synthesizing secretory proteins, bind to microsomal membrane vesicles. This binding appears to be dependent on the nature of the translation product (presumably the specific signal peptide) rather than on the mRNA itself. In addition, pretreatment of the membrane vesicles with N-ethyl maleimide prevents the vectorial discharge and processing of several secretory proteins but does not inhibit the binding of their polysomes to membranes.

Animals↗
PubMed1978

Precursor of egg white ovomucoid. Amino acid sequence of an NH2-terminal extension.

The translation of ovomucoid mRNA in a reticulocyte lysate protein-synthesizing system yields a precursor form which contains an NH2-terminal extension of 23 amino acid residues. Edman degradation of radioactive translation products (pre-ovomucoid) identified the following sequence: formula : (see text), where the initiator methionine (in parentheses) is the only residue cleaved from the NH2 terminus during cell-free synthesis and the vertical line indicates the site at which pre-ovomucoid is cleaved in vivo to yield ovomucoid. The precursor sequence differs from those of two other proteins (pre-lysozyme and pre-conalbumin) secreted by the same cell, but resembles these and other secretory protein "signal peptides" in both length and hydrophobicity. Pre-ovomucoid does not interact with trypsin in the same manner as mature ovomucoid.

Amino Acid Sequence↗
PubMed1978

Identical precursors for serum transferrin and egg white conalbumin.

The NH2-terminal sequences of egg white conalbumin and chicken serum transferrin were examined and found to be identical. Conalbumin, when synthesized in a rabbit reticulocyte cell-free translation system, was found to contain an NH2-terminal extension of 19 amino acid residues. Sequential Edman degradation of this precursor (pre-conalbumin) labeled with radioactive amino acids revealed the following sequence: formula see text: The vertical line indicates the site at which pre-conalbumin is cleaved to yield authentic conalbumin. The sequence represents the primary translation product since the NH2-terminal methionine was shown to be derived from initiator Met-tRNAfMet. A partial NH2-terminal sequence of transferrin synthesized in vitro was also determined (underlined residues) and it is identical with that of pre-conalbumin.

Amino Acid Sequence↗
PubMedDate not supplied

Linkage relationships between DXS105, DXS98, and other polymorphic DNA markers flanking the fragile X locus.

We report on linkage data between DXS105, DXS98, the locus for the fragile X syndrome (FRAXA), and 3 other polymorphic loci that flank the FRAXA locus. An analysis was undertaken to determine the relative positions of DXS105 and DXS98 and to test the assignment of DXS105 to a location proximal and closely linked to FRAXA. In this study of fragile X fra(X) syndrome families, the DXS105 locus was calculated to be proximal to FRAXA with a maximum lod score of 10.36 at theta = 0.08. DXS105 was also shown to be closely linked to the gene for factor IX (F9)(Z = 11.84 at theta = 0.08) and to DXS98 (Z = 4.91 at theta = 0.04). The order of the loci proximal to FRAXA is most likely centromere-factor IX-DXS105-DXS98-FRAXA-telomere. The use of DXS105 and DXS98 in clinical investigations should significantly increase the accuracy of risk assessment in informative fragile X families.

Chromosome Mapping↗