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Biomedical subjects

J M Friedman

Publications and source records attributed to J M Friedman.

At least 307 records · Page 17Linked to original sources

Longitudinal studies of chromosomal abnormalities and reticulum cell proliferation in New Zealand Black mice.

A longitudinal study of 40 New Zealand Black (NZB) mice and 20 BALB/c control animals was performed. A significant association was observed between the presence of acquired spleen-cell aneuploidy at some time during life and development of histological evidence of reticulum-cell neoplasia in individual animals. This finding is compatible with the hypothesis that aneuploid clones which arise in the spleens of aging NZBs are at least potentially neoplastic. However, no relationship between histologically neoplastic reticulum cell proliferation and aneuploidy was apparent in single splenic specimens obtained from NZB mice of various ages. This lack of association indicates that failure to detect chromosomal abnormalities on direct study of cells from a tumor cannot be taken as evidence that the neoplastic cells themselves lack such abnormalities.

Aneuploidy↗

Neoplastic behavior of chromosomally abnormal clones in New Zealand Black mice.

Old New Zealand Black (NZB) mice frequently develop reticulum-cell sarcoma and clones of aneuploid cells in their spleens. In order to define the relationship between neoplasms and chromosomal abnormalities, the pattern of distribution of aneuploid cells was studied to see if it corresponds to that expected of the malignancy, and chromosomally aberrant or normal spleen cells were transplanted into syngeneic newborn recipients. The results indicate that aneuploid cells arise focally but may disseminate widely in an affected mouse. A strong association was found between spleen-cell aneuploidy in a transplantation donor and both aneuploidy and histological evidence of reticulum-cell sarcoma in young recipients. Chromosomal aberrations in young recipients were always of donor origin. On the basis of these data, it seems likely that aneuploid clones which arise in the spleens of old NZB mice usually are at least potentially neoplastic.

Aneuploidy↗

Effects of pH and temperature on the interaction of an impermeant probe with surface proteins of the human red blood cell.

The conformation of the outer surface of the human red cell membrane has been studied under various conditions using the impermeant probe [125I]diazodiiodosulfanilic acid. At least seven polypeptides were labeled by the reagent, including the three extractable glycoproteins separable by the electrophoretic method employed. The Mr = 43,000 protein band was shown to contain two labeled species, one a glycoprotein, in addition to its major constituent, red cell actin. The extent and pattern of labeling were very sensitive to changes in pH and temperature. Total labeling increased with increasing pH and was greater at 4 degrees C than 37 degrees C. Binding of the probe to the Mr = 90,000 polypeptide and the major glycoprotein were relatively increased with increasing pH and temperature while opposite effects were observed for the Mr = 43,000 peptide(s). The pH effects on external membrane labeling were rapidly reversible. Results were similar in cells of different densities, suggesting that the pH and temperature effects were not related to cell age. The data presented emphasize the lability of membrane conformation and reactivity and thus the necessity to consider carefully the conditions of labeling in interpretation of studies using impermeant probes.

Erythrocyte Membrane↗

Specificity of acquired clonal chromosome abnormalities in New Zealand Black mice.

New Zealand Black (NZB) mice, an inbred strain characterized by immunological dysfunction and lymphoreticular malignancy, also develop populations of aneuploid spleen cells. In detailed cytogenetic analyses performed on 10 NZBs, the chromosomally abnormal cells were found to be clonally related within each mouse. Moreover, the karyotypic changes observed were highly non-random, usually involving the 15 (10/10 mice), 2 (8/10 mice), 16 or 17 (9/10 mice), and sex (6/10 mice) chromosomes. These observations suggest an important relationship between chromosomal alterations and tumorigenesis in NZB mice and emphasize the role of chromosome 15 in murine abnormal lymphoreticular proliferations.

Animals↗

Studies of the HLA complex in families of children with congenital heart disease.

In order to test the hypothesis that HLA-linked developmental determinants are involved in the pathogenesis of congenital heart disease, we performed tissue typing on 10 families in which two or more siblings had cardiac malformations. No association between the occurrence of congenital heart disease and the HLA complex was found.

Epitopes↗

Ataxia and hearing loss secondary to perilymphatic fistula.

Ataxia is rarely attributed to lesions of the peripheral vestibular system. In 1973, the first case of ataxia and hearing loss secondary to a labyrinthine fistula was reported. Until now, this syndrome has not been reported in patients under the age of 10 years. A case is presented of a 5-year-old boy with symptoms of ataxia and hearing loss as well as vertigo and tinnitus after head trauma. Three physical findings appear to be most characteristic of patients with perilymphatic fistulas: a positive fistula response, positive positional testing with the involved ear down, and evidence of vestibular ataxia when testing station and gait. The absolute diagnosis of perilymphatic fistula can only be established by exploration of the middle ear space. If a fistula is found, it may be sealed with soft tissue and, if this fails, actual stapedectomy may be required.

Ataxia↗

Topography of the external surface of the human red blood cell membrane studied with a nonpenetrating label, [125I]diazodiiodosulfanilic acid.

The topography of the external surface of the human red cell membrane has been studied using an impermeant radioactive probe, [125I]diazodiiodosulfanilic acid, which binds covalently to protein groups of the membrane following reaction with intact cells. The pattern of labeling was assessed by sodium dodecyl sulfate-polyacrylamide disc gel electrophoresis followed by sequential analysis of single gels for carbohydrates (by staining with the periodic acid-Schiff (PAS) reagent), for proteins (by staining with Coomassie blue), and for radioactivity (by counting gels sliced in 2-mm segments). The radioactive probe bound to membrane polypeptides with apparent molecular weights of 94,200, 58,100, and 46,500 (Peaks A, B, and C, respectively). Peak A co-migrated with a small periodic acid-Schiff-positive band and protein Band 3 (nomenclature of Steck) (Steck, T.L. (1974)J. Cell Biol. 62: 1-19). Peak B migrated with protein Band(s) 4.5 slightly ahead of the major membrane glycoprotein (PAS-1). Peak C migrated like glycoprotein PAS-2 and protein Band 5, the actin-like, water-soluble membrane protein. In contrast to lactoperoxidase iodination and a number of other probes, [125I]diazodiiodosulfanilic acid reacted minimally with the major membrane glycoprotein, glycophorin. When it was reacted with isolated ghosts, all molecular weight classes of polypeptides were labeled. Treatment of labeled cells with neuraminidase or trypsin altered the glycoprotein staining pattern, but not the radioactive peaks. On the other hand, Pronase eliminated the Mr=94,200 radioactive peak, diminished the other two radioactive peaks, and profoundly changed the glycoprotein and protein staining patterns. Treatment of the membranes of labeled cells in a low ionic strength alkaline medium did not alter radioactive peaks and demonstrated that Peak C differed from the actin-like membrane protein. A nonionic detergent, Triton X-100, solubilized all radioactive components. The studies have defined the binding of [125I]diazodiiodosulfanilic acid to external proteins of the human red cell membrane. Its pattern of reaction differs quantitatively and qualitatively from other commonly used reagents, and it provides a useful additional vectorial probe for the study of membrane topography. Its reactions provide further evidence of the organizational complexity of the red cell membrane and emphasize the fact that interpretation of information derived from the use of membrane probes must take into account the differences resulting from the properties of the probing reagents themselves.

Azo Compounds↗

Saethre-Chotzen syndrome: a broad and variable pattern of skeletal malformations.

A family is described in which 15 persons in five generations are affected with a complex of skeletal malformations which variably includes peculiar asymmetric facies, delayed closure of large fontanels, brachycephaly, acrocephaly, brachydactyly, cutaneous syndactyly, broad great toes, and mild shortness of stature. Although craniosynostosis is either lacking or relatively mild in the members of this family, their features are otherwise strikingly similar to those of patients with the Saethre-Chotzen syndrome. We believe the findings in this family indicate that the Saethre-Chotzen syndrome comprises a broad pattern of carniofacial and other skeletal malformations in which craniosynostosis may sometimes occur.

Acrocephalosyndactylia↗

Excited state lifetimes in cytochromes measured from Raman scattering data: evidence for iron-porphyrin interactions.

Resonance Raman scattering excitation profile data have been obtained on ferrocytochromes c and b5 in the alpha absorption band region. We observe in cytochrome c that the shape of the excitation profile agrees with the absorption band shape, while in cytochrome b5 it does not. In addition, we observe in cytochrome b5 a linewidth substantially larger than that in cytochrome c. From our data we conclude that the excited state lifetime in cytochrome c is longer than that in cytochrome b5 and that in cytochrome b5 the relaxation of the pi-pi* excited state configuration of the porphyrin ring is different in the x direction than in the y direction. Possible origins of these effects due to coupling to the d-d transitions of the iron atom are discussed.

Cytochrome c Group↗

Autoimmunity in the relatives of patients with immunodeficiency diseases.

Autoimmune disorders are reportedly more frequent than expected in immunodeficient patients and in their relatives. The hypothesis that genetic factors related to immunodeficiency may predispose to the development of autoimmunity was studied in relatives of patients with variable immunodeficiency (VID), ataxia-telangiectasia (A-T), or X-linked infantile agammaglobulinaemia (X-LA). Close relatives of patients with VID or A-T had thyroid and gastric autoantibodies significantly more frequently than did control subjects. No abnormalities were detected in unaffected relatives of X-LA patients. The increased incidence of organ-specific autoantibodies in close relatives of VID patients was confined to those families with more than one member with immunodeficiency. These data suggest that there are at least two forms of VID, one of which is associated with familial autoimmunity. It is postulated that heterozygous carriers of the A-T gene and persons with genes involved in the development of VID may exhibit T-lymphocyte dysfunction which predisposes them to autoimmunity.

Adolescent↗

Viral "tumorigenesis" in man: cell markers in condylomata acuminata.

Determination of the glucose-6-phosphate dehydrogenase (G-6-PD) phenotype of a neoplasm occurring in a heterozygous female can be used to trace the cellular origin of the tumor. This technique was performed on 834 individual verrucous subunits from four condylomata acuminata (venereal warts) arising in two patients heterozygous for a B and an A gene at the G-6-PD locus. All four specimens contained both A and B types of G-6-PD. Furthermore, even single verrucous subunits from each specimen occasionally contained both enzyme types. These data indicate that condylomata acuminata have a multicellular origin. The initial number of cells which, after viral infection, developed into a condyloma acuminatum was estimated to be about 4,400 cells, on the basis of statistical analysis of the data in one case.

Adolescent↗