Search PubMed⌕ Search

Biomedical subjects

T Berg

Publications and source records attributed to T Berg.

390 records · Page 22Linked to original sources
PubMedDate not supplied

A role for scavenger receptors in phagocytosis of protein-coated particles in rainbow trout head kidney macrophages.

In macrophages of higher vertebrates, Fc receptors and receptors for complement and other serum factors, are generally known to enhance the phagocytic process. In lower vertebrates like salmonid fishes, none of these or other phagocytic receptors have been thoroughly characterized. The purpose of this study was to elucidate to what extent these and other receptors are involved in the process of phagocytosis in rainbow trout (Oncorhynchus mykiss) head kidney macrophages. We used tosyl activated, paramagnetic dynabeads (2.8 microm in diameter), specifically coated with 125I labeled Atlantic salmon (Salmo salar) IgM or bovine serum albumin (BSA) as phagocytic probes. The effect of complement opsonization was also investigated by incubating the beads in serum. Our results indicate that neither the Fc- nor the complement-receptor(s) were important for phagocytosis of these beads. Our data support the idea that scavenger receptors are involved in phagocytosis in rainbow trout head kidney macrophages, as the use of a competitive scavenger receptor ligand extensively decreased degradation of the labeled protein coat on the beads.

Animals↗
PubMedDate not supplied

Purification and characterization of five cuticular proteins from the spider Araneus diadematus.

Urea-extractable proteins have been purified from the cephalothoracic cuticle of mature Araneus diadematus spiders. Two-dimensional gel electrophoresis showed at least 12 major proteins, with pIs between 4.5 and 8.5. Five proteins were purified and their primary structure determined, using a combination of mass spectrometry and Edman degradation. Based on the amino acid sequence the proteins can be divided into two groups, both characterized by hydrophobic regions dominated by Ala, Pro and Val. Sequence similarity was observed between all the spider cuticle proteins and a number of proteins from other arthropod cuticles. Although the similarity seemed to be confined only to a region in the central part of the molecules, it does link these very distantly related species.

Amino Acid Sequence↗
PubMedDate not supplied

Sound change in child language: a study of inter-world variation.

The goal of this study is to retrace in minute detail a single step forward in the phonological development of a German-speaking child. The sound change under focus is the acquisition of velar stops in word-initial positions. Naturalistic data were collected on a daily basis over a period of approximately one year (3;4.9 - 4;3.20) until the process was nearly completed. Production accuracy was found to be under the influence of four factors--the nature of the velar stop (voiced or voiceless), the subsequent context, lexical stress and the individual word in which the critical consonant appeared. Progress was made not globally but in different subdomains at different points in time. Each phonological constellation gave rise to a distinct acquisitional pattern. While the velar stops were accurately produced before the alveolar nasal, they tended to be omitted before the rhotic and supplanted by the alveolar stops before the lateral. An attempt is made to identify the locus of the changes in a developing processing system consisting of linguistic units (nodes) and their interrelationships (associations). A comparison of the effects of inefficient nodes and those of inefficient associations suggests that learning in this child takes place by strengthening the associations rather than increasing the efficiency of processing on the nodes. Because modifying individual associations is quite a local repair process, it is argued that the acquisition of a new segment does not normally occur across the board. Instead, it is more appropriately conceived of as a gradual spread through the lexicon.

Child Language↗
PubMedDate not supplied

Out of the dark.

Explore the source record for details and available documents.

Certification↗
PubMedDate not supplied

Induction of T helper cell type 1 response and elimination of HBeAg during treatment with IL-12 in a patient with therapy-refractory chronic hepatitis B.

This study reports the increase of immunoregulatory T helper cell type 1 response and elimination of HBV-DNA during IL-12 therapy in a patient with chronic hepatitis B virus infection who had not responded to three previous interferon-alpha therapies and one treatment with Famciclovir over a period of 6 years. The patient received IL-12 at a dose of 0.5 microgram/kg bodyweight weekly. Peripheral blood mononuclear cells were isolated before and during IL-12 application and incubated for 7 days with specific type 1 (purified protein derivative) and type 2 (tetanus-toxoid) TH cell antigens as well as with a macrophage/monocyte activating antigen (Bacille Calmette-Guérin). In the supernatants cytokines were determined by a double-sandwich ELISA. After 8 weeks HBV-DNA became negative and HBeAg seroconversion to anti-HBeAg occurred. Immunologically the loss of viremia was accompanied by a strong increase of the purified protein derivative-induced production of the type 1 cytokine interferon-gamma (1219 pg/mL before, 13,138 pg/mL after IL-12 therapy). Furthermore, Bacille Calmette-Guérin-induced secretion of the macrophage/monocyte-associated cytokines IL-1, tumor necrosis factor-alpha and granulocyte-macrophage colony-stimulating factor was higher at the end of therapy. This case indicates that IL-12 enhances type 1 T helper cell activity which may be a predisposition for elimination of HBeAg and successful treatment of hepatitis B.

Adjuvants, Immunologic↗