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I Schenkein

Publications and source records attributed to I Schenkein.

At least 19 recordsLinked to original sources
PubMed1981

Immunocytochemical investigations on the submandibular glands of developing and adult mice using a specific antiserum on protease A.

The submandibular glands of developing and adult mice were studied immunocytochemically by the unlabeled antibody peroxidase-antiperoxidase and the colloidal gold-protein A methods, using an antiserum to a highly purified esteroprotease (protease A, EC 3.4.4) of mouse submandibular gland origin. A thin subluminal rim of immunoreactivity, seen in striated duct cells throughout development, persisted in adulthood. From 15 days of age onwards, striated duct cells with diffuse cytoplasmic staining also occurred; such cells increased in number with age. A clear sexual dimorphism of the submandibular gland was first discernable by 25 days of age, when the developing granular convoluted tubule (GCT) cells of males were slightly larger than those of females; this size difference became more pronounced at later ages, resulting in a distinct dimorphism by 50 days of age. In adults, the principal sites of immunoreactivity were the GCTs, whose component cells stained with different intensities. Electron microscopic immunocytochemical techniques revealed that deposits of oxidized diaminobenzidine or particles of celloidal gold were restricted to the secretion granules of GCT cells; all other organelles were unstained. Acinar and intercalcated duct cells were negative.

Animals↗
PubMed1981

Hormonal regulation of epidermal growth factor and protease in the submandibular gland of the adult mouse.

The structure of the granular convoluted tubules of the mouse submandibular gland is influenced by androgens, adrenal steroids, and thyroid hormones. We wished to investigate the effects of variations in hormonal status on the quantitative and qualitative distribution of two secretory products of these tubules, epidermal growth factor (EGF) and protease. The effects of the thyroid and adrenal glands on EGF content and protease activity of the submandibular glands of adult female mice were studied by RIAs (EGF), enzyme assays (protease), and immunocytochemical methods. In animals rendered chronically hypothyroid by propylthiouracil (4 months) or in animals which were adrenalectomized and ovariectomized (3 weeks), protease activity and EGF levels were reduced by 81-97%. The administration of testosterone induced these polypeptides even in hypothyroid animals. Daily administration of L-T4 (T4; 1 micrograms/g BW) for 7 days increased EGF and protease activity 3.6-fold in intact mice and reversed the effect of hypothyroidism. EGF and protease were also induced by T4 in adrenalectomized and ovariectomized mice, although to a lesser degree than in intact animals. Immunocytochemical stainings of submandibular glands indicated that the number of granular convoluted tubule cells immunoreactive for EGF correlated with the levels of EGF determined by RIAs. With respect to immunostaining for protease, such a correlation was not observed. The data indicate multihormonal regulation of EGF and protease in the mouse submandibular gland.

Adrenal Glands↗
PubMed1980

Immunocytochemical localization of nerve growth factor, submandibular glands of Tfm/Y mice.

The submandibular glands of mice with testicular feminization (Tfm/Y) and their normal adult male littermates (Ta/Y) were studied by immunocytochemical techniques for the demonstration of epidermal growth factor (EGF), nerve growth factor (NGF), renin and protease A. In the glands of both the affected and normal males, these polypeptides were restricted to cells of the granular convoluted tubules (GCT), with the exception of protease A, which was also found in small amounts in striated duct cells. Compared to those of Ta/Y males, GCTs were narrower in the glands of Tfm/Y mice and contained a markedly reduced number of cells immunoreactive for EGF, NGF and renin. However, the number of GCT cells that stained for protease A in the glands of Tfm/Y males was not as drastically decreased.

Androgen-Insensitivity Syndrome↗
PubMed1980

Epidermal growth factor, renin, and peptidase in cultured tumor cells of submandibular gland origin.

Dimethylbenz[a]anthracene was injected into the submandibular glands of male Swiss-Webster mice. From tumors obtained, three cell lines were established. Immunocytochemical stainings revealed epidermal growth factor, renin, and peptidase in a significant portion of cultured tumor cells. In addition, the presence of epidermal growth factor was demonstrated by radioimmunoassays. Since epidermal growth factor, renin, and peptidase are localized in the granular convoluted tubules in mouse submandibular gland, the data suggest that the granular convoluted tubule cells are the targets of chemical carcinogens.

Animals↗
PubMed1976

Partial purification and characterization of a heat-labile enterotoxin of Escherichia coli.

A partially purified enterotoxin was obtained from the growth medium of Escherichia coli strain 711 (P307), a derivative of E. coli K-12, by ultrafiltration, precipitation with ammonium sulfate, molecular sieving, and anion exchange column chromatography. The active moiety, which is heat-labile, behaved like a protein particle of 180,000 to 200,000 daltons during molecular sieving and ultracentrifugation. During polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE), it dissociated into two subunits with apparent molecular weights of 68,000 to 70,000 and 14,000 to 15,000. SDS-PAGE after heating in SDS changed the larger subunit to an apparent molecular weight of about 40,000; the smaller subunit did not change. The intact particle induced rounding of the cells in Y-1 mouse adrenal tumor cells used for assay. The detergent-dissociated molecules were not active. Proteolysis of the purified toxin by tolylsulfonyl phenylalanyl chloromethyl ketone-trypsin appeared to enhance its activity. The addition of serum to the assay medium resulted in partial depression of the activity. Activity was also abolished by preincubation of the toxin with either a rabbit antiserum to it or solutions containing GM1 ganglioside. The length of time needed to evoke a response in the assay system by fractions from different stages in the purification of the enterotoxin was a useful parameter in the evaluation of specific activity.

Bacterial Proteins↗
PubMed1971

Sepcific removal of in vivo antibody by extracorporeal circulation over an immunoadsorbent in gel.

A method is described for preparation of a solid immunoadsorbent suspended in an agar gel. The immunoadsorbent in gel retains its specificity. Rabbits were injected with antibody or antigen, and an extracorporeal circulation was established through columns or funnels coated with such immunoadsorbents. It was shown that either antibody or antigen can be specifically and rapidly removed, and that no measurable amounts of antigen from the immunoadsorbent were released into the animals.

Acetates↗