Enhancement of antibody formation by hypersensitivity reaction

Zusammenfassung Eine Anzahl Kaninchen wurde durch humanes Serumalbumin (HSA) sensibilisiert. Wurde bei ihnen durch eine weitere Dosis desselben Antigens (HSA) eine Hypersensitivitätsreaktion hervorgerufen, so wurde die Antikörperbildung gegen ein anderes gleichzeitig eingeführtes Antigen (Ovalbumin-OA) stimuliert.     

Quantitative determination of enzymic activities in cells and in extracellular fluid aspirated from human tumors by needle biopsy

Zusammenfassung Es wird eine Punktionsmethode zur quantitativen Bestimmung der Enzymaktivität in Zellen und interstizieller Flüssigkeit menschlicher Tumoren beschrieben. Die in den Zellen und der interstiziellen Flüssigkeit von Mammacarcinomen und -fibroadenomen gemessene Dipeptidaseaktivität wurde mit derjenigen verschiedener Körperflüssigkeiten verglichen.     

Induction of rotational behaviour by intranigral baclofen suggests possible GABA-agonist activity

Summary In rats, unilateral injections of the GABA-derivative baclofen into the zona reticulata of the substantia nigra produced a contralateral rotation that was translated to ipsilateral rotation under the influence of amphetamine. These results mimic those following unilateral elevation of GABA levels in the substantia nigra and suggest that baclofen may have some GABA agonist activity following intracerebral injection.Baclofen was a generous gift of Ciba-Geigy Ltd.J. L. W. is a Medical Research Council Scholar.     

Effects and duration of resistance acquired by rabbits on feeding and egg laying in Ixodes ricinus L.

Rabbits gradually developed a resistance against Ixodes ricinus ticks as a result of sequential experimental infestations. The resistance was characterized by an increase duration of feeding, by ticks engorging to a smaller extent and by reduced egg production. Once established, the immunity persisted for at least 9 months. Changes in the titre of circulating anti-I. ricinus antibodies was measured by indirect immunofluorescence.     

Divalent cation-phospholipid complexes and tumor growth inhibition

Summary Growth inhibition of DS sarcomas provoked by calcitonin treatment is accompanied by an increase of calcium and magnesium in the phospholipid fraction. Changes in tumor cell membrane characteristics reflected in ionic or molecular transport modifications seem to be involved in the growth impairment phenomenon.We thank Prof. K. Goerttler, Institut für experimentelle Pathologie, Deutsches Krebsforschungszentrum, Heidelberg (Federal Republic of Germany) for the DS sarcoma tumors, and Sandoz SA, Bâle, Switzerland for the gift of salmon calcitonin.     

Defining G protein-coupled receptor peptide ligand expressomes and signalomes in human and mouse islets

Introduction

Islets synthesise and secrete numerous peptides, some of which are known to be important regulators of islet function and glucose homeostasis. In this study, we quantified mRNAs encoding all peptide ligands of islet G protein-coupled receptors (GPCRs) in isolated human and mouse islets and carried out in vitro islet hormone secretion studies to provide functional confirmation for the species-specific role of peptide YY (PYY) in mouse islets.

Materials and methods

GPCR peptide ligand mRNAs in human and mouse islets were quantified by quantitative real-time PCR relative to the reference genes ACTB, GAPDH, PPIA, TBP and TFRC. The pathways connecting GPCR peptide ligands with their receptors were identified by manual searches in the PubMed, IUPHAR and Ingenuity databases. Distribution of PYY protein in mouse and human islets was determined by immunohistochemistry. Insulin, glucagon and somatostatin secretion from islets was measured by radioimmunoassay.

Results

We have quantified GPCR peptide ligand mRNA expression in human and mouse islets and created specific signalomes mapping the pathways by which islet peptide ligands regulate human and mouse GPCR signalling. We also identified species-specific islet expression of several GPCR ligands. In particular, PYY mRNA levels were ~ 40,000-fold higher in mouse than human islets, suggesting a more important role of locally secreted Pyy in mouse islets. This was confirmed by IHC and functional experiments measuring insulin, glucagon and somatostatin secretion.

Discussion

The detailed human and mouse islet GPCR peptide ligand atlases will allow accurate translation of mouse islet functional studies for the identification of GPCR/peptide signalling pathways relevant for human physiology, which may lead to novel treatment modalities of diabetes and metabolic disease.