Biomedical subjects

U Andersson

Publications and source records attributed to U Andersson.

147 records · Page 9Linked to original sources

PubMed1980

Cellular mechanisms of restricted immunoglobulin formation in the human neonate.

The functional capacity of human neonatal B lymphocytes has been investigated by in vitro methods using T lymphocyte-dependent (pokeweek mitogen, PWM) and -independent (Epstein-Barr virus, EBV) polyclonal B cell activators. B cell activation of single cells was detected by class-specific immunoglobulin (Ig) secretion using a reversed hemolytic plaque assay. It was found that neonatal B cells were triggered to secretion of IgM by EBV, with a magnitude comparable to adult levels, but that, in contrast to B cells from adults, they did not secret IgG. Cord lymphocytes did not secret Ig although they displayed a sizable DNA synthetic response to PWM. Using cell separation and culture experiments, it was shown that (allogeneic) adult T lymphocytes could restore cord B cell responsiveness to PWM and that cord T lymphocytes could not cooperate with adult B cells. In addition to this immaturity of cord T helper function for antibody synthesis, we found cells in the cord T cell-enriched fraction which inhibited the polyclonal response of adult lymphocytes to both PWM and EBV. These lymphocytes suppressed adult B lymphocytes directly but appeared ineffective against neonatal B lymphocytes themselves. The nature of these suppressing cells and their possible role in the fetal/maternal relationship are a matter of speculation.

Antibody-Producing Cells↗

PubMed1980

The influence of heat symptoms and the time of insemination of cattle on the early and late returns.

In a material comprising 95,085 inseminations, the non-return rate and the frequency of late returns, measured as the frequency of returns, measured as the frequency of returns between 29 and 56 days, have been studied with respect to the time of insemination within the heat period and to the intensity of heat. Both these factors have effected the NR result in that insemination late in the oestrus period--2 days after heat has been observed--gives the poorest result, 60.5% 56 days NR in comparison with 68.5 one day after observation and 71.4 the same day. Weak heat symptoms give a bad result, 60.1 compared to 68.7 for fair and 72.7 for strong heat symptoms. The differences are significant. The number of late returns is also influenced by the time of insemination as well as by the intensity of heat. However, insemination in heats with weak symptoms leads to a higher frequency of late returns than what can be expected from the frequency of early returns. This might partly indicate an increased rate of early embryonic death.

Animals↗

PubMedDate not supplied

Heterogeneity in the expression of markers for drug resistance in brain tumors.

Brain tumors, in general, display a multidrug-resistant phenotype. This study evaluated the immunohistochemical expression and distribution of P-glycoprotein (Pgp), multidrug resistance protein (MRP1), lung resistance protein (LRP) and O6 methylguanine-DNA methyltransferase (MGMT) in low- and high-grade astrocytoma, oligodendroglioma and in different subgroups of meningioma. The results revealed a marked heterogeneity in the expression and distribution among the analyzed tumors. In astrocytoma and oligodendroglioma, Pgp and MRP1 were observed in the capillary endothelium and in scattered tumor cells, whereas LRP occurred only in tumor cells. A pronounced expression of MGMT was found independent of the histopathological grade. An enhanced expression of MRP1 and LRP in astrocytoma and oligodendroglioma were more often evident in older patients (> 50 years). Survival analysis suggested a markedly decreased overall survival for patients suffering from low-grade glioma overexpressing Pgp. In meningioma, a heterogeneous expression of Pgp, MRP1, LRP and MGMT was seen with the most prominent staining localized to the capillary endothelium. Pgp was significantly more often overexpressed (p < 0.05) in transitional compared to meningothelial meningioma. The marked heterogeneity in the expression suggests that analysis of these factors can be of importance in the selection of individualized chemotherapy, regardless of tumor type.

ATP Binding Cassette Transporter, Subfamily B, Mem↗