Circulatory physiology ofNautilus

Summary Present information places the circulatory performance ofNautilus at the bottom of the cephalopod scale but shows it to be distinctly different from that of gastropods and bivalves. The feature which clearly places it closer to its coleoid relatives than to other groups of molluscs is the enhancement of the branchial circulation by the beating pericardial glands and renal appendages. These organs have their homologues in the coleoid pericardial chamber. Recently, studies of living embryos show that the development of a functional circulatory system is an early event during ontogeny and that this information may have important implications for our understanding of the evolution of a branchial circulation.     

Alpha-fetoprotein in tumor-bearing mice assayed by particle agglutination inhibition

Summary Serum alpha-fetoprotein (AFP) in hepatoma BW7756-bearing mice was measured by a new particle agglutination inhibition test employing AFP adsorbed to charcoal particles. The AFP levels and tumor weights showed nearly parallel increases to means of 2633 g/ml and 5.2 g, respectively, 28 days after implantation. *** DIRECT SUPPORT *** A2025089 00011     

Abortive effect of autologous anti-alpha-fetoprotein antibodies in the rat]

Female Commentry Rats 80--85 days old, were immunized by 5 intramuscular injections of Mouse alphafetoprotein (AFP) and then mated. After fertilization a supplementary injections was administered. The animals were bled at different times and killed immediately after the last bleeding on the 19 or 20th day of gestation. Titers of AFP and of autologous anti-AFP antibodies in the maternal blood were determined as well as the AFP concentration in the pooled amniotic fluids from live embryos of each litter. Compared to non-immunized control series, the total of live and dead embryos per litter in animals immunized with Mouse AFP showed no difference. However, the number of live embryos was on the average 50% lower than that in the control series. The serum titers of AFP and of antibodies to autologous AFP in immunized pregnant Rats bearing dead embryos decreased concomitantly with the number of live embryos. The results reported herein demonstrate that the presence of anti-autologous AFP antibodies in pregnant Rats correlates with the interruption of development in a significant proportions of embryos. This suggests that certain spontaneous abortions in the Rat and perhaps in other mammals can be explained by the rupture of immunological tolerance to autologous AFP.     

Alpha-fetoprotein in tumor-bearing mice assayed by particle agglutination inhibition.

Serum alpha-fetoprotein (AFP) in hepatoma BW7756-bearing mice was measured by a new particle agglutination inhibition test employing AFP adsorbed to charcoal particles. The AFP levels and tumor weights showed nearly parallel increases to means of 2633 microgram/ml and 5.2 g, respectively, 28 days after implantation.     

Fixation of polyunsaturated fatty acids by alpha fetoprotein and serum albumin in rats. Comparison with the accumulation of these acids in developing rat brain]

Quantitative data are presented on the fatty acid composition of rat alpha-fetoprotein (AFP) and serum albumin, (SA), and of brain extracts of suckling rats. In AFP and SA preparations, 40% and 13%, respectively, of total fatty acids present are polyenoic acids. Among them, docosahexaenoic acid is quantitatively the most important in AFP, while in SA, arachidonic acid is largely predominant. Both docosahexaenoic and arachidonic acids were the predominant polyenoic acids in brain extracts. The rate of accumulation of these acids in the brain of suckling rats and the rate of AFP secretion during the same period showed a maximum around 10--12 days after birth. These results suggest that AFP and SA play an important role in the transport and the incorporation of polyunsaturated fatty acids in the developing brain.     

Experimental studies of the development of migratory orientation mechanisms

Summary Recent experimental studies (since ca 1985) on the ontogeny of orientation mechanisms in migratory birds are reviewed. The processes and interactions are synthesized into a framework that may help identify critical research questions. Birds that grow up in the earth's magnetic field develop the ability to perform appropriate migratory orientation even in the absence of any experience with relevant visual cues. In two species, large changes in direction during the course of migration seem to be controlled by an endogenous time program. In one of these, the pied flycatcher (Ficedula hypoleuca), the correct magnetic orientation seems to occur only when the magnetic fields appropriate to the latitudes encountered en route were experienced at the proper seasonal time. The magnetic compass may be modified by visual experience with either the daytime or night sky. Celestial rotation may be the calibrating reference in this case, as it is in the development of the star compass. Young Savannah sparrows (Passerculus sandwichensis) learn to perform compass orientation at sunset based on polarized skylight. This compass capability seems to be calibrated by magnetic directions. Some problems of experimental design and the interpretation of results from experiments on development are discussed.     

Fractionation of mouse alpha-fetoprotein.

4 distinct alpha-fetoprotein (AFP) containing fractions were obtained upon ion-exchange chromatography of late-gestational fetal mouse extracts. Despite this chromatographic heterogeneity, the individual AFP isolates were antigenically indistinguishable.     

Intracellular localization of alpha-fetoprotein and serum albumin in the central nervous system of the rat during fetal and postnatal development]

The morphological localisation of alphafetoprotein (AFP), serumalbumin (SA), transferrin and immunoglobulins (IgG) has been studied in the developing central nervous system of the Rat by immunocytochemical methods. Evidence is presented of a highly selective staining for AFP and SA, both proteins exhibiting the same topographical distribution. Practically all the areas of the brain and the spinal cord are stained at a given moment of the developmental process. The labeling is cytoplasmic and in the neuronal elements extends to their axonic and dendritic prolongations. The localization of AFP and SA in the nervous system may be related to the well known binding properties of these proteins for varied substances (estrogen and/or fatty acids). The morphological data presented here suggest that both proteins may be actively involved in the uptake of such substances by the cellular structures of the nervous tissue.     

The kinetics of estrogen binding to rat alpha-fetoprotein

Fluid obtained from rat fetuses was utilized to characterize the affinity, number of binding sites, and the association and dissociation rate kinetics of the binding of estradiol and estrone to AFP. Statistical analysis demonstrated no differences when the values for the AFP-estradiol interaction were compared with those obtained for the ATP-estrone interaction. These data demonstrate that rat AFP specifically binds estradiol and estrone with a high capacity, high affinity, and similar binding kinetics.     

The kinetics of estrogen binding to rat α-fetoprotein

Summary Fluid obtained from rat fetuses was utilized to characterize the affinity, number of binding sites, and the association and dissociation rate kinetics of the binding of estradiol and estrone to AFP. Statistical analysis demonstrated no differences when the values for the AFP-estradiol interaction were compared with those obtained for the AFP-estrone interaction. These data demonstrate that rat AFP specifically binds estradiol and estrone with a high capacity, high affinity, and similar binding kinetics.This work was supported by NSF grant PCM-8109847 and by a Grant-in-Aid of Research from Sigma Xi, The Scientific Research Society.     

Developmental actions of natriuretic peptides in the brain and skeleton

The concept that atrial natriuretic peptide (ANP) and the closely related peptides BNP and CNP might be involved in the ontogeny of several organ systems emerged in the late 1980s. While many of the reported in vitro actions have not been examined in the context of organ development in vivo, recent studies demonstrate that mice which lack or overexpress natriuretic peptides or receptors exhibit pronounced skeletal growth defects. This article discusses how natriuretic peptides and other factors appear to regulate bone growth as an example of how natriuretic peptides might participate in the ontogeny of other organ systems. Evidence indicating that natriuretic peptides regulate neural development is then reviewed. Natriuretic peptides and receptors exhibit complex expression patterns in the developing nervous system, where they have been shown to act on neural cells as early as at the embryonic neural tube stage. Interestingly, both bone and brain growth appear to utilize primarily CNP and the CNP-specific type B receptor, and perhaps the type C receptor. In vitro data indicate that CNP may act on developing neurons, astrocytes and Schwann cells like a classical growth factor, regulating proliferation, patterning, phenotypic specification, survival and axonal pathfinding. Natriuretic peptides might also have roles in the vascularization of the embryonic brain, establishment of the blood-brain and blood-nerve barriers, and perhaps in nerve regeneration.Received 13 April 2004; received after revision 20 May 2004; accepted 27 May 2004     

Female canaries display to songs of early isolated males

We tested the sexual responsiveness of female canaries,Serinus canaria, to two sets of different types of male conspecific songs. In each set, three of the male songs had been recorded in a young bird which was isolated at an early age from conspecifics. Each bird was recorded during three stages of the song ontogeny (early plastic songs, late plastic songs and crystallized songs). We used copulation solicitation displays (CSD) as an index of female sexual response. Playbacks were performed during a period of natural sexual responsiveness of the females to song. We demonstrated that, in both experiments, very weak sexual displays of female canaries were recorded to the two stages of isolate plastic songs. Each of the two different types of isolate crystallized songs elicited high levels of CSD. These levels are not significantly different from the adult domesticated control song. Taken together, these results suggest that even isolate songs may convey sexual information. We discuss prominent acoustic features that must be present to ensure female sexual responses.     

Distribution of the 1,25 dihydroxy-vitamin D3 receptor in the bursa of Fabricius of chicken

The vitamin D₃ metabolite 1,25(OH)₂D₃ is probably involved in B lymphocyte ontogeny. We therefore determined the distribution of the 1,25(OH)₂D₃ receptor in the bursa of Fabricius and spleen cells of 7-day-old chicks, by immunohistochemistry using a monoclonal antibody against the chick intestinal cell 1,25(OH)₂D₃ receptor. The bursa cells of young (7-day-old) chicks contained large amounts of receptor while the spleen cells did not. The bursa cells of older (35-day-old) chicks contained fewer receptors, but the number of receptors in the spleen increased.     

Magnetic orientation and celestial cues in migratory orientation

Summary Young birds on their first migration possess innate information on the direction of their migration route. It is present in two forms, using celestial rotation and the geomagnetic field as references. These two systems, together with information provided by factors associated with sunset, interact in a complex way to establish the migratory direction. During ontogeny, celestial rotation appears to be dominant; during migration, however, celestial cues appear to be controlled by the magnetic field. The factors associated with sunset — the view of the setting sun, the characteristic pattern of polarized light — are important secondary cues which seem to derive their directional significance from the magnetic field. Their role appears to be more variable, with possible species-specific differences. During spring migration and later autumn migrations, flying in the migratory direction is complemented by navigational processes which enable the birds to return to a specific home site known from previous stays.     

Eye lens development and gamma crystallins in Discoglossus pictus (Anura).

The ontogeny and localization of the gamma crystallins in Discoglossus pictus lens development has been determined. Using antibody specific for amphibian gamma crystallins in the immunofluorescence technique, it was found that gamma crystallins first appear in primary lens fibre cells in the lens rudiment, and continue to be restricted to the fibre area as lens development progresses. Thus the role of gamma crystallins as indicators of a differentiated state remains constant in amphibian evolution, having been demonstrated in the most archaic anuran superfamily, as well as in others more recently evolved.     

Distribution of the 1,25 dihydroxy-vitamin D3 receptor in the bursa of Fabricius of chicken.

The vitamin D3 metabolite 1,25(OH)2D3 is probably involved in B lymphocyte ontogeny. We therefore determined the distribution of the 1,25(OH)2D3 receptor in the bursa of Fabricius and spleen cells of 7-day-old chicks, by immunohistochemistry using a monoclonal antibody against the chick intestinal cell 1,25(OH)2D3 receptor. The bursa cells of young (7-day-old) chicks contained large amounts of receptor while the spleen cells did not. The bursa cells of older (35-day-old) chicks contained fewer receptors, but the number of receptors in the spleen increased.     

Localization of substance P in the nervous system of the human fetus : preliminary results

Substance P (SP) immunoreactive structures were localized by immunofluorescence technique within the central nervous system of human fetuses (12, 15, 19 and 24 weeks old). Specificity of the anti-SP serum was established by immunocytology and radio-immunology. A wide distribution of SP positive structures (pericaryons and/or fibres) was found in brain, spinal cord and dorsal root ganglia. Mesencephalon, pons and dorsal horns of the spinal cord showed very intense fluorescence. The preliminary observations are the first report concerning SP ontogeny in the Human central nervous system. However, it was difficult to ascribe a significance to this neuropeptide during fetal life.     

The multiple roles of monocyte subsets in steady state and inflammation

Monocytes participate importantly in immunity. Produced in the bone marrow and released into the blood, they circulate in blood or reside in a spleen reservoir before entering tissue and giving rise to macrophages or dendritic cells. Monocytes are more than transitional cells that adapt to a particular tissue environment indiscriminately. Accumulating evidence now indicates that monocytes are heterogeneous in several species and are themselves predetermined for particular function in the steady state and inflammation. Future therapeutics may harness this heterogeneity to target harmful functions while sparing those that are beneficial. Here, we review recent advances on the ontogeny and function of monocytes and their subsets in humans and mice.     

Functions of fatty acid binding proteins

Summary Cytosolic fatty acid binding proteins (FABP) belong to a gene family of which eight members have been conclusively identified. These 14–15 kDa proteins are abundantly expressed in a highly tissue-specific manner. Although the functions of the cytosolic FABP are not clearly established, they appear to enhance the transfer of long-chain fatty acids between artificial and native lipid membranes, and also to have a stimulatory effect on a number of enzymes of fatty acid metabolism in vitro. These findings, as well as the tissue expression, ligand binding properties, ontogeny and regulation of these proteins provide a considerable body of indirect evidence supporting a broad role for the FABP in the intracellular transport and metabolism of long-chain fatty acids. The available data also support the existence of structure- and tissue-specific specialization of function among different members of the FABP gene family. Moreover, FABP may also have a possible role in the modulation of cell growth and proliferation, possibly by virtue of their affinity for ligands such as prostaglandins, leukotrienes and fatty acids, which are known to influence cell growth activity. FABP structurally unrelated to the cytosolic gene family have also been identified in the plasma membranes of several tissues (FABP_pm). These proteins have not been fully characterized to date, but strong evidence suggests that they function in the transport of long-chain fatty acids across the plasma membrane.