Complementation of class II A alleles in the immune response to (GluLysTyr) polymers

The proliferative T cell responses to poly(GluLysTyr) (GLT) and poly(GLULysPhe) (GLPhe) are restricted by the E alpha E beta class II MHC molecule (E) in most responded strains. Some nonresponder strains that carry responder E beta, but cannot express cell surface E molecules, can complement with other nonresponder strains that provide the missing E alpha chain needed for the expression of E molecules and for responsiveness to GLT and GLPhe. Here another type of complementation is described between two E-nonexpressor haplotypes, H-2f and H-2s, which result in E-nonexpressor F1 hybrids, which are responders to GLT. The restriction element involved in this response is an Af/As hybrid molecule. The data support the hypothesis that conformational determinants resulting from the free association of alpha and beta chains in heterozygotes can increase the immune potential of the individual.     

Preparing monolayers of non-adherent mammalian cells

A simple method is described for preparing monolayers of non-adherent cells, using concanavalin A to bind the cells to wells of plastic microtest plates. The method was used successfully with all 202 human cell types tested, which included 23 tissue culture lines, 165 fresh specimens of all major histological types of leukemia and lymphoma, 20 fresh myelomas, 2 fresh thymomas, normal spleen and lymph node cells, fractionated T lymphocytes and B lymphocytes from peripheral blood, and cultured fetal amniotic cells. All cell types attached firmly, and were not detached by subsequent vigorous washing. In contrast, attempted attachment of cells in serum free medium, or with poly-L-lysine or glutaraldehyde, was ineffective with many cell types. We used the monolayers as target cells for antibodies to cell surface antigens, utilizing immune rosetting or complement-mediated cytotoxicity. This procedure should simplify most assays involving non-adherent target cells.     

Identification of high risk patients with severe, but asymptomatic aortic stenosis

Whether asymptomatic patients with severe aortic stenosis benefit from surgery remains unclear. We report our data recently published in the New England Journal of Medicine on the natural history of this disease and predictors of outcome.     

TRIO amplification and abundant mRNA expression is associated with invasive tumor growth and rapid tumor cell proliferation in urinary bladder cancer

Studies by comparative genome hybridization have suggested that 5p amplification is related to tumor progression in urinary bladder cancer. In this study seven genes (TAS2R, ADCY2, DNAH5, CTNND2, TRIO, ANKH, and MYO10) located to 5p15.31-5p15.1 were analyzed by fluorescence in situ hybridization using a tissue microarray containing samples from tumors and cell lines with known 5p amplification by comparative genome hybridization. Amplification frequency was highest for TRIO, which maps to 5p15.2 and encodes a protein with a putative role in cell-cycle regulation. To further investigate the role of TRIO amplification in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for fluorescence in situ hybridization analysis. TRIO amplification was strongly associated with invasive tumor phenotype, high tumor grade, and rapid tumor cell proliferation (Ki67 LI) (P < 0.0001 each). Only 7 of 456 pTaG1/G2 tumors (1.5%) but 62 of 485 pT1-4 carcinomas (12.8%) had TRIO amplification. TRIO amplification was not associated with poor prognosis. Using a frozen bladder tumor tissue microarray RNA in situ hybridization confirmed that TRIO is up-regulated in amplified tumors. It is concluded that TRIO up-regulation through amplification has a potential role in bladder cancer progression.     

The formation of B-lymphocyte colonies in agar contained in glass capillaries.

Optimal conditions were established for a micro method for the production of colonies of B lymphocytes from mouse spleen cells cultured in agar in glass capillaries, in the presence of bacterial lipopolysaccharide (LPS). Besides LPS the cultures require 5 X 10(-5) M mercaptoethanol and 20% horse serum for optimal colony growth. Foetal calf serum and heat-inactivated horse or foetal calf serum were found to be inferior. An agar gel strength of 0.3% was best for colony counting. A sigmoid curve was obtained when the number of colonies formed was related to the seeded cell density suggesting that some kind of cell to cell co-operation is essential for colony formation. The daily kinetics of colony growth were followed by microscopic colony counting and photometric capillary scanning with integration of the signal areas. Both methods indicated that colony growth had ceased by day 6. The combination of both methods gave the most realistic picture of B-lymphocyte colony development.     

Cytoprotection by somatostatin of normal and malignant clonogenic cells against the in vitro cytotoxicity of bischloroethylnitrosourea (BCNU)

The various pharmacological effects of somatostatin may be explained by the hypothesis that the paracrine peptide, by "stabilizing" cell membranes, inhibits the secretion of hormones as well as protects other cells (vascular endothelium, parenchyma) from different lesions (vasculo-, organo-, cytoprotection). This hypothesis was tested in vitro, using bischloroethyl-nitrosourea (BCNU)-intoxicated stem cells of normal mouse granulopoiesis and of the L 1210 leukemia. Clonogenic mouse bone marrow and L 1210 cells were grown in agar-containing glass capillaries. Using these colony assays and a ID90 of BCNU, cyclic somatostatin influenced the BCNU-cytotoxicity neither at simultaneous nor at subsequent application. However, when given 2 h prior to BCNU, the inhibition of colony growth was almost totally abolished. This cytoprotective effect was seen with normal granulopoietic as well as with leukemic cells. The effect did not show up, if the inactive linear somatostatin was used. N-acetyl-cysteine, a SH-compound applied as a chemoprotective adjunct, did not reveal a cytoprotective effect under identical experimental conditions, either. The results were discussed in view of common efforts to reduce the toxicity of cancer chemotherapy.     

Nichtinvasive Beatmungs- und Lagerungstherapie bei COVID-19

Die Anaesthesiologie - Schwere Verläufe von COVID-19 führen bei Versagen einer unterstützenden nichtinvasiven Beatmung („high flow“, CPAP bzw. NIV) zur Eskalation der...