Glycosphingolipids of human umbilical vein endothelial cells and smooth muscle cells.

Glycosphingolipids (GSLs) represent an important class of immunogens and receptors. Although cell surface antigens and receptors of endothelial cells (ECs) have been the subject of extensive biochemical investigation, no information is available about their GSLs. We report here the characterization by chromatographic and immunological techniques of GSLs of cultured human umbilical vein ECs and, for comparison, umbilical vein smooth muscle cells (SMCs).

Low serum B12 levels in a hematologically normal elderly subpopulation.

Serum Vitamin B12 levels were determined on 378 patients ranging in age from 56 to 104 years with a median age of 77 for both males and females. A radiodilution method was employed for these determinations. This screening procedure identified 26 patients with low serum B12 levels.

New abnormalities in the morphology, cell surface receptors, and electrolyte metabolism of In(Lu) erythrocytes.

The In(Lu) phenotype is inherited as an autosomal dominant trait and is characterized by suppression of the Lutheran, P1, i, and Aua erythrocyte blood group antigens. We have developed a monoclonal antibody (L21) that strongly agglutinates all erythrocytes except In(Lu), and we have identified eight In(Lu) individuals among 42,000 blood donors tested. Studies of two families confirmed the dominant mode of inheritance and revealed several new features of this phenotype.

Sidedness of action of loop diuretics and ouabain on nonsensory cells of utricle: a micro-Ussing chamber for inner ear tissues.

It is known that nonsensory tissues of the utricle produce a lumen-positive transepithelial electrical potential difference (VT). This potential has been shown previously to be inhibited by ouabain and bumetanide applied to the bathing medium in vitro. In order to more fully characterize the origin of this potential we mounted the utricle as a flat sheet in a newly designed Ussing chamber and measured the VT and transepithelial resistance (RT) while perfusing the endolymphatic and perilymphatic surfaces independently with identical solutions.

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. I. Large-scale cultivation of carcinoembryonic antigen-producing cells on cylindric cellulose-based microcarriers.

A continuous cell line from a human colon carcinoma, designated HuCC1-14, was successfully grown on cyclindrical cellulose microcarriers (MC) charged by DEAE. The cells grow on these carriers as large cell-MC aggregates and maintain high cell densities in submerged conditions for extended periods. HuCC1-14 cells secrete into the culture medium significant amounts of carcinoembryonic antigen (CEA).

Production of carcinoembryonic antigen from a human colon adenocarcinoma cell line. II. Use of monoclonal antibodies to carcinoembryonic antigen for antigen purification and characterization.

Monoclonal antibodies (McAbs) were prepared against carcinoembryonic antigen (CEA), derived from human metastases to the liver of primary colon adenocarcinoma. A stable clone, secreting monoclonal anti-CEA antibody (Ab), was selected. The hybridoma cells were grown in BALB/C mice, forming ascites fluids containing 2-5 mg/ml of the relevant McAbs.

Effect of iodoacetic acid upon cochlear potentials.

Lotz et al. reported that perilymphatic application of 5 X 10(-3) M iodoacetic acid (IAA) in the guinea pig does not influence the first-order cochlear microphonics (CM1) under aerobic conditions. However, in ischemia the rate of decline of the second-order microphonics (CM II, also called postmortem CM) was significantly increased by IAA.

Studies of the mechanism by which gangliosides inhibit the proliferative response of murine splenocytes to concanavalin A.

Gangliosides are known to inhibit the proliferative response of murine and human lymphocytes to antigens and mitogens in vitro. In this study the response of murine spleen cells to concanavalin A (Con A) was used as a model system. Analysis of the cellular events by flow cytometry revealed that during the first 24 hr of culture the effect of gangliosides on Con A-treated cells was minimal.

The occurrence of anti-3-fucosyllactosamine antibodies and their cross-reactive idiotopes in preimmune and immune mouse sera.

The carbohydrate determinant 3-fucosyllactosamine (3-FL), Gal(beta 1-4)[Fuc alpha 1-3]GlcNAc-R, which is also known as SSEA-1 or as the X determinant, is very immunogenic in BALB/c mice. Many monoclonal antibodies directed against this structure have been obtained by immunization of mice with murine teratocarcinomas and human carcinomas and myeloid cells. We have undertaken an analysis of the regulation of these antibodies and of their idiotypic, structural, and genetic diversity.

Transepithelial electrical potential of nonsensory region of gerbil utricle in vitro.

Transepithelial electrical potential difference (VT) was measured across the vestibular labyrinth of the inner ear in vitro by puncturing the epithelial wall of the utricle with a glass microelectrode. A region of nonsensory cells of the utricle was isolated from the sensory regions by introducing columns of liquid Sylgard 184. Under control conditions, the VT of this region was +7.

Folate and vitamin B12 levels in an urban elderly population with chronic diseases. Assessment of two laboratory folate assays: microbiologic and radioassay.

Folate levels of serum and red blood cells (RBC) and vitamin B12 serum levels were investigated in 326 urban chronically ill elderly ambulatory patients and 41 healthy young control subjects. Two laboratory methods were used for investigating the folate levels, the microbiologic assay (MBA) with Lactobacillus casei and radioassay (RA). Serum and RBC samples of 326 patients were tested by the folate MBA and 270 of the same samples by the RIA methods.

Idiotypic determinants of monoclonal antibodies that bind to 3-fucosyllactosamine.

Many monoclonal antibodies that react with the lacto-N-fucopentaose III (LNF III) antigenic determinant, Gal beta 1-4(Fuc alpha 1-3)GlcNAc beta 1-3Gal beta 1-4Glc, have been described recently. The terminal trisaccharide of this determinant, fucosyllactosamine, is present on glycolipids and glycoproteins and on the surface of granulocytes, monocytes, and other cells. To study the structural and genetic diversity of these antibodies, syngeneic anti-idiotypic monoclonal antibodies were produced in BALB/c mice against PMN 6, a monoclonal antibody directed against this sequence.

Direct measurement of longitudinal endolymph flow rate in the guinea pig cochlea.

The rate of longitudinal endolymph flow in the guinea pig cochlea has been measured with a novel tracer technique. The tracer we utilized was the tetramethylammonium (TMA) ion, the movement of which was monitored by ion-sensitive microelectrodes. Extremely small amounts of tracer were required as the electrodes could readily detect TMA concentrations in endolymph as low as 10 microM.

Membrane transport parameters in frog corneal epithelium measured using impedance analysis techniques.

Active Cl- transport in bullfrog corneal epithelium was studied using transepithelial impedance analysis methods, and direct-current (DC) measurements of membrane voltages and resistance ratios. The technique allows the estimation of the apical and basolateral membrane conductances, and the paracellular conductance, and does not rely on the use of membrane conductance-altering agents to obtain these measurements as was requisite in earlier DC equivalent-circuit analysis studies. In addition, the analysis results in estimates of the apical and basolateral membrane capacitances, and allows resolution of the paracellular conductance into properties of the tight junctions and lateral spaces.

Clinical disorders of iron metabolism in the elderly.

When iron deficiency occurs in the elderly, it is usually due to bleeding and not to nutritional lack or malabsorption. Iron deficiency early in life may lead to irreversible changes (for example, gastric achlorhydria) that are troublesome in later life. The nonhematologic effects of iron deficiency still need to be studied in the elderly.

Spontaneous and plasma factor-mediated transfer of pyrenyl cerebrosides between model and native lipoproteins.

A series of pyrenyl glucocerebrosides was synthesized by reacylation of psychosine with pyrene-labeled fatty acids having 3-11 methylene units. When incorporated into model high-density lipoproteins consisting of dimyristoylphosphatidylcholine-apolipoprotein A-II complexes and incubated with unlabeled complexes, these lipids exhibited spontaneous transfer. Half times of transfer varied from 1.

Retinal detachment following endophthalmitis.

Fifty-five consecutive patients with a clinical diagnosis of bacterial endophthalmitis were reviewed. All patients were treated with systemic, periocular, topical, and intravitreal antibiotics. In addition, 33 of the patients underwent a pars plana vitrectomy.