Extracellular dopamine and neurotensin in rat prefrontal cortex in vivo: effects of median forebrain bundle stimulation frequency, stimulation pattern, and dopamine autoreceptors

In vivo microdialysis coupled with HPLC and radioimmuno-assay techniques were used to analyze dopamine (DA) and neurotensin (NT) in prefrontal cortical extracellular fluid following electrical stimulation of mesocortical axons. The release (overflow into the extracellular fluid) of both DA and NT increased with increasing number of impulses and with frequency. At the lowest frequency tested (2.5 Hz), DA release was significantly increased, while there was no significant increase in the release of NT. As the frequency of stimulation was increased from 2.5 to 20 Hz, the ratio of extracellular DA:NT decreased exponentially. Stimulation in a burst pattern produced greater release of both DA and NT than tonic stimulation when the number of impulses per second and the total number of impulses were held constant. Furthermore, blockade of DA autoreceptors with sulpiride stereoselectively increased the release of DA while decreasing the release of NT. These data suggest that the release of coexistent molecules (DA and NT) from mesocortical neurons can be influenced by physiological and pharmacological factors such that under certain conditions simultaneous or differential release may occur.     

Differential expression of acidic and basic FGF in the rat substantia nigra during development.

Both acidic (aFGF) and basic (bFGF) fibroblast growth factors have been shown to be present in the adult rat ventral mesencephalon and to exert effects on cultured mesencephalic cells. In the present study we have examined the expression of aFGF and bFGF in the rat ventral mesencephalon at various stages of development. bFGF was present at all ages examined [embryonic day 16 (E16) to postnatal day 90 (P90)]. In contrast, aFGF was not detectable at embryonic and early postnatal ages, but was observed at later (P20, P60, P90) postnatal stages. These data suggest that aFGF and bFGF may have functions in mesencephalic dopamine neurones in different stages of development.     

Electron microscopic evidence for the association of M 2 protein with the influenza virion

Summary Immunogold electron microscopy revealed that site-specific antibodies elicited by a synthetic peptide representing the N-terminal sequence (residues 2–10) of influenza virus M 2 protein were capable of binding to the surface of virions. Antibody binding was observed with two human influenza virus strains but not with an avian virus strain which has amino acid substitutions in the appropriate sequence of M 2. These results provide direct evidence for the presence of M 2 in the influenza virion.     

Ausfallhonorar wegen Nichterscheinens zu einem Exklusiv-Termin

Abstrakt 1. Nimmt ein Patient einen ihm von seinem (Zahn-)Arzt einger?umten Exklusiv-Termin nicht wahr, obwohl er auf dessen Eigenschaft ausdrücklich hingewiesen wurde, so hat er dem (Zahn-)Arzt den Behandlungsausfall abzüglich eines angemessenen Eigenanteils des (Zahn-)Arztes zu ersetzen. 2. Die Ersatzpflicht tritt auch dann ein, wenn der Patient den Termin nicht in der in dem Behandlungsvertrag vorgesehenen Frist absagt. Eine hierfür seitens des (Zahn-)Arztes bestimmte Frist von zwei Tagen vor Behandlungsbeginn stellt sich für den Patienten grunds?tzlich auch nicht als unangemessene Benachteiligung i.S. des § 307 BGB dar. 3. Ein Anspruch des Arztes entf?llt auch bei nur mündlicher Vereinbarung nicht unter dem Gesichtspunkt des § 4 Abs. 5b BMV-Z, denn diese Vorschrift ist teleologisch dahin zu reduzieren, dass nur zahn?rztliche Honoraransprüche aus erfolgten Behandlungen schriftlich vereinbart werden müssen. Soweit es jedoch um einen vertraglichen Anspruch wegen einer Leistungsst?rung geht, vermag das Schriftformerfordernis des § 4 Abs. 5b BMV-Z grunds?tzlich nicht einzugreifen. (Leits?tze des Bearbeiters)     

Role of IL-2 in rat fetal thymocyte development

Early during rat thymus ontogeny, an important proportion of thymocytes expresses IL-2R and contains IL-2 mRNA. To investigate the role of the IL-2-IL-2R complex in rat T cell maturation, we supplied either recombinant rat IL-2 or blocking anti-CD25 mAb to rat fetal thymus organ cultures (FTOC) under several experimental conditions. The IL-2 treatment initially stimulated the growth of thymocytes and, as a result, induced T cell differentiation, but the continuous addition of IL-2 to rat FTOC, as well as the anti-CD25 administration, resulted in cell number decrease and inhibition of thymocyte maturation. These results indicate that immature rat thymocytes bear functional high- affinity IL-2R and that IL-2 promotes T cell differentiation as a consequence of its capacity to stimulate cell proliferation. Modifications in TCR alpha beta repertoire and increased numbers of NKR- P1+ cells, largely NK cells, were also observed in IL-2-treated FTOC. Furthermore, IL-2-responsiveness of different thymocyte subsets changed throughout thymic ontogeny. Immature CD4-CD8-cells responded to IL-2 in two stages, early in thymus development and around birth, in correlation with the maturation of two distinct waves of thymic cell progenitors. Mature CD8+ thymocytes maximally responded to IL-2 around birth, supporting a role for IL-2 in the increased proliferation of mature thymocytes observed in vivo in the perinatal period. Taken together, these findings support a role for IL-2 in rat T cell development.      

Serum concentrations of oestradiol-17beta, progesterone, relaxin and chorionic gonadotrophin during blastocyst implantation in natural pregnancy cycle and in embryo transfer cycle in the rhesus monkey

The present study was undertaken to assess the temporal association between the profiles of serum concentrations of oestradiol-17beta, progesterone, chorionic gonadotrophin (CG) and relaxin in pregnancies established naturally, and after embryo transfer, as well as in failed pregnancies in rhesus monkeys. In naturally mated cycles (group 1) a conception rate of 75% was obtained. In group 1, the mean day of CG detection in serum was 11.5 +/- 1.9 day post-ovulation, and for relaxin, 9.0 +/- 2.5 day post-ovulation. In group 2, embryo transfer to synchronous, non-mated surrogate recipients was performed; seven embryo transfer cycles yielded three pregnancies which were allowed to continue to term and normal infants were delivered. In embryo transfer cycles the mean day of CG detection was 14.8 +/- 1.8 day post- ovulation, and for relaxin, 11.4 +/- 2.6 day post-ovulation. A delay of about 3 days was observed in the appearance in circulation of CG (P < 0.05) and also of relaxin (P < 0.05) between natural mated and embryo transfer conception cycles. Significant differences (P < 0.05 for progesterone and P < 0.03 for oestradiol) were obtained for the areas under the curves for progesterone and oestradiol between days 12 and 16 in conception cycles compared with failed pregnancies. These data provide the first observation of the normal hormonal signals associated with maternal recognition of transferred embryos during the peri- implantation period, and suggest that the use of such an experimental primate embryo transfer model may help to elucidate components of maternal and embryonic signal-response mechanisms during embryo implantation.