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B R Mullin

Publications and source records attributed to B R Mullin.

14 recordsLinked to original sources
PubMed1992

Localization of transforming growth factor-beta isotypes in lesions of the human breast.

Transforming growth factor-beta s (TGF-beta) comprise a highly conserved family of multifunctional cell regulatory peptides that may play a role in a variety of pathologic processes. To date, five TGF-beta isotypes have been identified, three of these in mammalian systems. A number of cultured human breast carcinoma cell lines produce biologically inactive latent TGF-beta and are growth inhibited by activated TGF-beta; TGF-beta production is estrogen-influenced in some of these cell lines. To investigate the potential role of the TGF-beta isotypes in human breast disease, we localized TGF-beta s 1, 2, and 3 immunohistochemically in normal breast, fibrocystic change, epithelial hyperplasia, sclerosing adenosis, fibroadenoma, cystosarcoma phyllodes, and several carcinoma variants. Transforming growth factor-beta s 1, 2, and 3 were identified intracellularly in most active mammary epithelia, regardless of the lesion, including carcinoma; the associated stroma contained little or no intracellular TGF-beta. An antibody that recognizes an extracellular conformation of TGF-beta stained normal intralobular stroma and, more extensively, the stroma of active fibroadenomas and low-grade phyllodes tumors and the desmoplastic stroma of carcinomas. The results indicate the potential for paracrine and autocrine regulation of the mammary gland by TGF-beta and suggest an association between TGF-beta and abnormal stromal proliferations. Altered expression of TGF-beta s 1, 2, and 3 at the protein level in mammary epithelia appears not to be a major feature of most breast lesions, raising the possibility that altered cellular response to the TGF-beta already present may play a role in the development of breast disease.

Breast↗
PubMed1986

Prevention of experimental allergic encephalomyelitis by ganglioside GM4. A follow-up study.

The myelin-specific ganglioside GM4, when incubated with myelin basic protein prior to inoculation, prevents experimental allergic encephalomyelitis in the guinea pig. The monosialoganglioside GM1, the predominant ganglioside of mammalian myelin, also prevents experimental allergic encephalomyelitis, whereas a mixture of neural gangliosides rich in polysialogangliosides causes enhanced disease. Guinea pigs inoculated with both myelin basic protein and GM4 develop serum IgG antibodies against basic protein, but not against GM4.

Animals↗
PubMed1984

Prevention of experimental allergic encephalomyelitis by ganglioside GM4.

Guinea pigs inoculated with a mixture of myelin basic protein and the myelin-specific ganglioside, sialosylgalactosylceramide (GM4), do not develop the signs or neuropathology of experimental allergic encephalomyelitis. The results indicate that GM4 cloaks the basic protein molecule so that it is no longer immunopathogenic in these animals. The interaction of basic protein with GM4, previously shown in vitro, appears to be relevant to the pathogenesis of experimental allergic encephalomyelitis in guinea pigs.

Animals↗
PubMed1981

Myelin basic protein interacts with the myelin-specific ganglioside GM4.

Demyelinated plaques in multiple sclerosis have decreased amounts of both myelin basic protein and sialosylgalactosylceramide (GM4), a ganglioside specifically localized in myelin and oligodendroglia of the central nervous system. We have found that myelin basic protein is capable of releasing large quantities of entrapped [14C]glucose from multilamellar liposomes containing GM4. If the conformation of GM4 in liposomal membranes resembles that of GM4 in its natural environment, basic protein and GM4 may be associated within the myelin sheath of the central nervous system and their interaction altered in demyelinating diseases such as multiple sclerosis.

Gangliosides↗
PubMed1980

Interaction of multiple sclerosis serum with liposomes containing ganglioside GM1.

Multiple sclerosis serum contains a factor or factors capable of releasing sequestered [14C]glucose from liposomes containing GM1, the major ganglioside present in human central nervous system myelin. Although some control sera can also release large quantities of liposomal glucose, multiple sclerosis and control sera differ in the mechanism of this release. Liposomal damage by multiple sclerosis serum does not appear to be complement mediated, but shares certain releasing characteristics of cholera toxin.

Adult↗
PubMed1979

Isolation and identification of a fucose-containing ganglioside from bovine thyroid gland.

Bovine thyroid glands are known to contain a complex array of gandliosides. One of the predominant gangliosides was isolated analyzed by gas-liquid chromatography and mass spectrometry. The carbohydrate composition was fucose, N-acetylneuraminic acid, galactose, N-acetylgalactosamine, and glucose in molar ratios of 1:1:2:1:1. The structure of the ganglioside was identified as: (Formula: see text).

Animals↗
PubMed1977

Delayed hypersensitivity in Graves' disease and exophthalmos: identification of thyroglobulin in normal human orbital muscle.

Patients with Graves' disease and exophthalmos demonstrate delayed hypersensitivity to antigens present in extracts of certain normal human tissue; namely,thyroid gland and retroorbital tissue. The delayed hypersensitivity can be assayed in vitro by quantitating the amount of a lymphokine, migration inhibition factor (MIF), which is produced when T lymphocytes of patients with Graves' disease and exophthalmos are exposed to these antigens. In the present report, a partial purification is described for the retro-orbital tissue antigen which is responsible for the positive leucocyte migration inhibition factor assay (MIF assay) exhibited by a sensitized lymphocytes of these patients. The purified retro-orbital tissue antigen preparation demonstrates a 50- to 150-fold higher specific activity over crude homogenates in its ability to act as an antigen in the MIF assay of exophthalmic patients. Immunodiffusion, ultracentrifugation, and disc electrophoretic data indicate that this purified antigen preparation, obtained from normal human, retro-orbital tissue, contains thyroglobulin or a derivative of thyroglobulin; immunofluorescence studies localize the anti-thyroglobulin reactive material to the plasma membranes of extraocular muscle fibers of normal individuals. On the basis of these data it is concluded that thyroglobulin or a derivative of the thyroglobulin molecule is present in the orbital muscle of normal individuals. Since thyroglobulin purified from normal human thyroid glands and the purified retro-orbital tissue preparation are nearly equivalent as antigens in the MIF assay of exophthalmic patients, we conclude that thyroglobulin or an antigenic component of the thyroglobulin molecule is one of the antigens to which patients with Graves' disease and exophthalmos demonstrate delayed hypersensitivity.

Antigens↗
PubMed1976

Thyrotropin-ganglioside interactions and their relationship to the structure and function of thyrotropin receptors.

Gangliosides inhibit 125I-labeled thyrotropin binding to the thyrotropin receptors on bovine thyroid plasma membranes, on guinea pig retro-orbital tissue plasma membranes, and on human adipocyte membranes. This inhibition by gangliosides is critically altered by the number and location of the sialic acid residues within the ganglioside structure, the efficacy of inhibition having the following order: GD1b greater than GT1 greater than GM1 greater than GM2 = GM3 greater than GD1a. The inhibition results from the interaction of thyrotropin and gangliosides, rather than the interaction of membrane and gangliosides. Fluorescence studies show that the inhibition is associated with a distinct conformational change of the thyrotropin molecule and that the progression from a "noninhibitory conformation" to an "inhibitory conformation" parallels exactly the order of effectiveness in inhibiting 125I-labeled thyrotropin binding. The ganglioside inhibition of 125I-labeled thyrotropin binding appears to be hormonally specific in that it is not affected by albumin, glucagon, insulin, prolactin, follicle-stimulating hormone, growth hormone, or corticotropin. The possibility that a ganglioside or ganglioside-like structure is a component of the thyrotropin receptor is suggested by the finding that gangliosides more complex than N-acetylneuraminylgalactosylglucosylceramide are present in bovine thyroid membranes in much higher quantities than have been previously found in extraneural tissue. The finding that the B component of cholera toxin, which also interacts with gangliosides, has a peptide sequence in common with the beta subunit of thyrotropin, suggests that thyrotropin and cholera toxin may be analogous in their mode of action on the membrane.

Adipose Tissue↗
PubMed1976

Cholera toxin interactions with thyrotropin receptors on thyroid plasma membranes.

Unlabeled cholera toxin inhibits [125I]thyrotropin binding to thyrotropin receptors on thyroid plasma membranes. Maximal inhibition by cholera toxin does not exceed 40%, whereas unalbeled thyrotropin completely inhibits [125I]thyrotropin binding to these same membranes. Kinetic analyses of the binding data are compatible with the view that the cholera toxin decreases the number of receptor sites available to thyrotropin and that the mechanism by which the cholera toxin inhibits [125I]thyrotropin binding to these receptor sites involves both competitive and noncompetitive elements.

Adenylyl Cyclases↗
PubMedDate not supplied

Exacerbation of adenomyosis symptomatology by estrogen-progestin therapy: a case report and histopathological observations.

The present case report illustrates the hormonal sensitivity of adenomyosis. Administration of an estrogen-progestin combination for what was felt to be symptomatic endometriosis resulted in exacerbation of symptoms and growth of adenomyomas. Histopathologic examination of the hysterectomy specimen revealed a pattern of decidualization previously unreported, but consistent with current theories of experimental in vivo and in vitro decidua formation.

Adult↗