Rapid intramolecular turnover of N-linked glycans in plasma membrane glycoproteins. Extension of intramolecular turnover to the core sugars in plasma membrane glycoproteins of hepatoma.

Plasma membrane glycoproteins of rat hepatocytes undergo a rapid terminal deglycosylation in that the terminal sugars of the oligosaccharide side chains are rapidly removed from the otherwise intact glycoproteins [Tauber, R., Park, C.S.

Selective isolation of individual cell surface proteins from tissue culture cells by a cleavable biotin label.

A method was developed to isolate cell surface proteins by a simple two-step procedure. Hepatocyte cell surface proteins were labeled by a cleavable biotin derivative in a covalent pulse reaction. Under the described conditions, NHS-SS-biotin proved to be an impermeant, cell surface-specific label which does not affect the impermeant, cell surface-specific label which does not affect the viability of rat hepatocytes.

Developmental changes in the glycosylation and binding properties of human fibronectins. Characterization of the glycan structures and ligand binding of human fibronectins from adult plasma, cord blood and amniotic fluid.

Fibronectins from human adult plasma, fetal plasma and from amniotic fluid obtained during early and late gestation were compared with respect to (i) their reactivity with lectins, (ii) their binding to the physiological ligands gelatin and heparin, and (iii) the role of the carbohydrate residues in the binding to these two ligands. The two fibronectin isoforms displayed distinct developmental differences in both glycosylation and binding properties: (i) Proportions of tri/tetraantennary complex glycans compared to the fraction of biantennary structures, as inferred from the reactivity with concanavalin A, were highest in amniotic fluid fibronectin from late pregnancy, lower in amniotic fluid fibronectin from early gestation, and even lower in fetal and adult plasma fibronectins. Likewise, fucose (alpha 1-6) linked to the innermost N-acetylglucosamine of the chitobiosyl core, defined by reactivity with Lens culinaris agglutinin (LCA), was present primarily in amniotic fluid fibronectin, and decreased in content during gestation from the 2nd.

Use of hepatocytes in adhesion and suspension cultures for liver support bioreactors.

Hepatocyte cultivation in bioreactors for hybrid liver support systems is possible under two conditions: attached to a substrate like membranes or microcarriers or in suspension culture. To compare the ammonia metabolism of hepatocytes cultivated under these two conditions, cultures of primary seeded rat hepatocytes were cultivated either attached to collagen coated tissue culture plastic or as a suspension culture. During the time course of culture, the ability of hepatocytes to reduce the ammonia content of the medium decreased in both adhesion and suspension cultures, though to different extents.

Decreased intramolecular turnover of L-fucose in membrane glycoproteins of rat liver during liver regeneration.

In plasma membrane glycoproteins of rat liver L-fucose undergoes a rapid intramolecular turnover in that fucose residues are removed from the glycoproteins (Tauber, R., Park, C.S.

Demonstration of glycosylation variants of human fibrinogen, using the new technique of glycoprotein lectin immunosorbent assay (GLIA).

A new highly sensitive method, incorporation the ELISA technique (enzyme-linked immunosorbent assay), is described for the quantitation of the glycan residues of glycoproteins. With the aid of this "glycoprotein-lectin immunosorbent assay (GLIA)", it is possible to determine the nature of the glycan residues of a single protein in a glycoprotein mixture, without prior purification. The GLIA can be used for the accurate determination of the inhibitor constant for the interaction of any monosaccharide with any lectin.

Incorporation of non-acetylated hexosamines into plasma membrane glycoproteins of liver cells after galactosamine injection.

The following procedure for the detection of non-acetylated amino sugars in the plasma membrane was established: i) derivatization of free amino groups with dansyl-chloride, ii) hydrolysis with 3 M HCl (for 4 h at 105 degrees C) to liberate the dansylated carbohydrate moieties from the plasma membrane, iii) purification of the dansylated amino sugars by paper chromatography and subsequent analysis by thin-layer chromatography. Using this procedure, plasma membranes from rat liver were analysed after injection of D-[14C]galactosamine. For this purpose, rats were divided into three groups: the first received D-galactosamine.

[Results of interstitial radiotherapy using I-125 seeds in the treatment of prostatic cancer].

30 patients with localized adenocarcinoma of the prostate were treated with pelvic lymphadenectomy and I-125 interstitial implantation from 1980 to 1985 (21/30 T3-tumors and 14/30 with poor differentiation). The mean follow-up is 59.5 months (range 18 to 88 months).

Half-lives of L-[35S]methionine and L-[3H]fucose of transferrin in the serum of rats.

The half-lives of 35S-labelled L-methionine and of 3H-labelled L-fucose of serum transferrin of rats were measured in pulse-chase experiments in vivo. Both L-[35S]methionine and L-[6-3H]fucose disappeared from transferrin with nearly the same half-lives of 33.8 h and 36.

[Role of glycoproteins in the pathogenesis of peptic ulcer].

Glycoproteins are major constituents of the two-component mucous barrier: glycoproteins of the mucin-type rich in carbohydrate groups form the viscoelastic mucous gel of the mucosa, oligosaccharides of glycoproteins and glycosphingolipids embedded into the plasma membrane form the glycocalyx of the epithelial cell surface. Both structures are thought to play major roles in protecting gastric mucosa against luminal acid and proteases. This assumption is supported by experimental evidence for mucus glycoproteins, however is largely hypothetical for cell surface glycoproteins.

Role of membrane glycoproteins in mediating trophic responses.

During growth and differentiation the plasma membrane has a key role not only in the reception and transmission of extracellular signals such as hormones and growth factors, but also in communicating cellular response to the cellular microenvironment. Cellular response to trophic stimuli includes alterations of cell shape and cell surface antigenicity, of cell-cell recognition and cellular adhesion, of cell matrix binding and the adaptation of cell surface receptors. The plasma membrane is therefore regarded as a 'central agency' for the integration of a single cell into the complex system of a tissue or of an organism.

[Catecholamine behavior, adrenoreceptor density of intact cells and sensitivity to catecholamines in a patient with orthostatic hypotension].

We evaluated sympathetic nervous system function in a patient with primary orthostatic hypotension. Plasma catecholamine levels--except for dopamine levels--and urinary catecholamine excretion were decreased, alpha-adrenoreceptor responsiveness to noradrenaline and beta-adrenoreceptor responsiveness to isoproterenol were increased according to increased beta-2-adrenoreceptor density on intact polymorphonuclear leukocytes. Alpha-2-adrenoreceptor density on intact platelets and adrenaline-induced platelet aggregation in vitro, however, were unchanged.

Different oligosaccharide processing of the membrane-integrated and the secretory form of gp 80 in rat liver.

Rat liver synthesizes a glycoprotein with Mr of 80.000 (gp 80) which is partly inserted into the plasma membrane and partly secreted into the serum. The membrane-integrated and the secretory form of this glycoprotein have an identical peptide pattern, but different N-linked glycans.

[Premedication with H1- and H2-receptor antagonists for intravenous urography using contrast media].

Intravenous urography using Telebrix was performed on 500 patients. Two hundred patients (group I) received no pre-medication; 300 patients (group II) were premedicated with H1 and H2 receptor antagonists. All patients were examined for signs of contrast reactions, blood pressure, pulse rate and plasma histamine levels.

Effect of chloroquine on the degradation of L-fucose and the polypeptide moiety of plasma membrane glycoproteins.

To evaluate the role of lysosomes in the breakdown of the carbohydrate and the polypeptide moiety of plasma membrane glycoproteins, degradation of the plasma membrane glycoprotein gp120 was studied in the liver of rats treated with the lysosomotropic amine chloroquine. Half-lives of degradation of the terminal sugar L-fucose and of L-methionine of gp120 were measured in isolated plasma membranes after pulse-chase experiments in vivo. Chloroquine extended the plasma membrane half-life of the polypeptide moiety of gp120 from 51 h to 143 h.

[Seminal duct malformations: clinical picture, diagnosis and therapy].

Seminal duct abnormalities occur more often than generally assumed. In most cases, they remain undetected if diagnostic measures are not undertaken because of infertility or recurrent urinary tract infections. An IVP should be performed if aplasia of the vas is detected, since ipsilateral agenesis of the kidney may also be present.

[Therapeutic and ethical problems of nephrostomy in tumor-related hydronephrosis].

A total of 101 patients with hydronephrosis due to tumor obstruction underwent palliative nephrostomies. The average survival was 8.6 months; after 3 months, 32% of the patients were dead.

Biopsy-coagulation forceps to simplify biopsy of the bladder.

Until now the forceps used for biopsy of the bladder has required a second procedure to coagulate the bleeding resulting from tissue removal. A new biopsy forceps is described, which makes it possible to perform the biopsy and coagulation simultaneously, thus, eliminating the inconvenience of having to change instruments during the operation. The shaft of the forceps through which the high frequency current flows is insulated completely so that the current exits only via the tips of the prongs.

[Histamine in the urogenital tract].

Tissue histamine determination in the urogenital tract showed that there are significant differences concerning tissue histamine content between intraoperative and postmortem tissue samples. The difference appeared to be most significant in the case of renal pelvis samples, where the decrease was about 90% in the autopsie material compared to intraoperative tissues. In comparing tissue histamine content in special organs of different animal species we discovered considerable differences; e.

Intramolecular heterogeneity of degradation in plasma membrane glycoproteins: evidence for a general characteristic.

Five integral plasma membrane glycoproteins (60, 80, 120, 140, and 160 kilodaltons) were isolated to homogeneity from rat liver by a four-step procedure: (i) extraction of plasma membranes with lithium diiodosalicylate, (ii) solubilization of glycoproteins with Nonidet P-40, (iii) affinity chromatography on concanavalin A-Sepharose, and (iv) semipreparative NaDodSO4/polyacrylamide gel electrophoresis. The glycoproteins contained 48.5--51.

Urinary cholesterol in cancer screening.

Cholesterol determinations in morning urine samples were taken in 235 selected patients with a positive test for microscopic hematuria. Values ranged from 0.2 to 76.