RESUMEN
Using frequencies of 86 genes from 23 loci of blood group systems, blood and milk proteins, the genetic relationships among 14 cattle breeds including four native Balkan and four synthetic Balkan-Alp breeds were studied. The dendrogram and nonlinear map construction shows a consensus 'Balkan breed cluster', an 'Alp breed cluster', an unstable position of synthetic breeds and well-separated American breeds. Positive partial correlations between genetic distance and time elapsed since introduction of farming while keeping geographical distances constant, and regular patterns over thousands of kilometers indicate that large-scale cattle population movements together with human migration (in the Neolithic age) from the Near East into Europe across the Balkans are the most likely explanation for the genetic distances observed in our data. More recent breed differentiation and selection do not yet blur this initial pattern of European cattle populations.
Asunto(s)
Bovinos/genética , Filogenia , Agricultura/historia , Crianza de Animales Domésticos/historia , Animales , Antígenos de Grupos Sanguíneos/genética , Proteínas Sanguíneas/genética , Bovinos/sangre , Europa (Continente) , Femenino , Frecuencia de los Genes , Ligamiento Genético , Marcadores Genéticos , Historia del Siglo XIX , Historia del Siglo XX , Historia Antigua , Masculino , Proteínas de la Leche/genética , Polimorfismo Genético , Especificidad de la EspecieRESUMEN
A novel class of enteric neurons projecting directly from the rectal wall to the spinal cord, "rectospinal neurons", was investigated in rats by combined retrograde neuronal tracing, immunocytochemistry and electron microscopy. Rectospinal neurons were almost confined to myenteric ganglia of the distal rectum below the pelvic diaphragm and were labeled preferentially by injections into spinal cord segments L6/S1. Injections into more rostral spinal cord segments resulted in hardly any labeled enteric neurons. Dorsal and ventral rhizotomy experiments indicated an almost exclusive projection of rectospinal neurons through dorsal roots L6/S1 to the respective spinal cord segments. Among various peptides immunostained, vasoactive intestinal polypeptide and calcitonin gene-related peptide were selectively found in rectospinal neurons, which were also shown to contain calbindin, neurofilament protein- and peripherin-immunoreactivity. Vasoactive intestinal polypeptide- and calbindin-immunostaining were frequently co-localized in the same perikarya, while calcitonin gene-related peptide-immunoreactive rectospinal neurons probably represented a separate population. Neonatal capsaicin treatment did not significantly reduce the number of rectospinal neurons. Electron microscopy revealed synaptic contacts on the surface of rectospinal neurons. Taken together, these results establish rectospinal neurons as an anatomically and neurochemically distinct class of enteric neurons. Synaptic contacts on rectospinal neurons suggest that these neurons may function as a direct link from the enteric to the central nervous system, thus indicating that connections between these two networks are reciprocal.
Asunto(s)
Plexo Mientérico/citología , Neuronas/citología , Recto/inervación , Médula Espinal , Estilbamidinas , Vías Aferentes/ultraestructura , Animales , Colorantes Fluorescentes , Ganglios Autónomos/citología , Ganglios Simpáticos , Peroxidasa de Rábano Silvestre , Masculino , Neuronas/química , Neuronas Aferentes/citología , Neuropéptidos/análisis , Ratas , Ratas Wistar , Aglutininas del Germen de TrigoRESUMEN
Serum immunoreactive parathyroid hormone (iPTH), ionized calcium, the urinary cyclic AMP/creatinine ratio (cAMP/Cr) and some indices of bone turnover (alkaline phosphatase (AP), serum osteocalcin, and the urinary total hydroxyproline/creatinine ratio (OH-P/Cr)) were measured in 26 preterm infants during the first 4 weeks of life. Despite of stimulated parathyroid gland activity cAMP/Cr, AP, osteocalcin and OH-P/Cr were low during the first week. Thereafter iPTH decreased, whereas cAMP/Cr, and the indices of bone turnover increased, reaching high-normal values (in comparison to full-term infants) during the second and third week of life. Serum iPTH was negatively correlated to cAMP/Cr in the first week (r = -0.61, p less than 0.01), whereas the relationship became positive during the second (r = 0.47, p less than 0.05) and third (r = 0.54, p less than 0.05) week of life indicating maturation of the renal response to PTH. The study supports the concept that in premature infants a transient pseudohypoparathyroid-like state is present during the first week of life reflecting an immaturity of renal and possibly bone response to PTH. This may be an etiological factor in hypocalcemia of prematurity.
Asunto(s)
Recien Nacido Prematuro/sangre , Hormona Paratiroidea/sangre , Peso al Nacer , Huesos/metabolismo , Calcio/metabolismo , AMP Cíclico/orina , Femenino , Edad Gestacional , Humanos , Recién Nacido , MasculinoRESUMEN
Three stable monoclonal antibodies to rat angiotensinogen were obtained by fusing myeloma cells with spleen cells from Balb/c mice injected with pure rat angiotensinogen. They were screened by their binding to pure iodinated angiotensinogen and to insolubilized angiotensinogen in a solid phase assay. The titers of the three antibodies varied from 1/3500 to 1/35000, their dissociation constants from 2.5 X 10(-8) M to 3.8 X 10(-10) M, and the sensitivity of the assay ranged from 200 to 10 pmol of pure angiotensinogen. These monoclonal antibodies did not recognize either angiotensin peptides or angiotensinogen from other species, except for mouse angiotensinogen, which cross-reacted with the different antibodies from 0 to 25%. Rat cerebrospinal fluid angiotensinogen, plasma des-angiotensin I-angiotensinogen, and plasma angiotensinogen were equally recognized by these monoclonal antibodies. Contrary to what was observed for a polyclonal antiserum, the monoclonal antibodies failed to inhibit the renin-angiotensinogen reaction in vitro.
Asunto(s)
Angiotensinógeno/inmunología , Angiotensinas/inmunología , Anticuerpos Monoclonales/biosíntesis , Angiotensinógeno/líquido cefalorraquídeo , Angiotensinógeno/metabolismo , Animales , Afinidad de Anticuerpos , Clonación Molecular , Reacciones Cruzadas , Hibridomas/inmunología , Ratones , Ratones Endogámicos BALB C , Ratas , Renina/metabolismo , Especificidad de la EspecieRESUMEN
In general syncytial sprouts and intervillous bridges are artifacts. Complete series of histological sections reveal that sprouts and bridges are caused by tangential sections through the syncytiotrophoblast. These observations are supported by scanning electron microscopy, graphical reconstructions and model experiments. However, it cannot be decided unequivocally whether short syncytial sprouts are artifacts or true differentiations of the syncytiotrophoblast.