The Vascularization of the Anuran Brain: The Mesencephalon

The angioarchitecture of the toad's mesencephalon is studied by scanning electron microscopy of vascular corrosion casts. The arterial supply is performed by the superior mesencephalic artery and by an artery arising from the ramus posterior of the arteria carotis cerebralis just in front of the retroin-fundibular communicating artery. The venous drainage is exerted by the vena diencephalica, the vena lateralis mesencephalis and by anterior and posterior branches of the encephaloposthypophysial portal vein. Characteristics of the mesencephalic angioarchitecture are the centrifugal direction of the blood flow, the intensive capillarization, and the formation of vascular meshworks in the region of the stratum griseum periventriculare tecti and of the stratum griseum superficiale tecti.     

Folding and refolding of proteins in chromatographic beds

The correct folding of solubilized recombinant proteins is of key importance for their production in industry. On-column refolding of proteins is mainly achieved by three methods: size-exclusion chromatography, ion exchange chromatography and affinity chromatography using immobilized metal chelates. The principles of these methods were first laid down in the 1990s, but many recent improvements have been made to these processes including sophisticated changes to the mobile phase composition and the recycling of aggregates to improve yield. Advances have also been made in the use of immobilized metal affinity chromatography and by mimicking the natural folding process with artificial chaperones.     

Parental mean ages and birth order in different types of congenital heart defects

Summary This study has shown that in some of the most common congenital cardiac malformations, such as valvular aortic stenosis, coarctation of the aorta, pulmonary stenosis, atrial and ventricular septal defect and tetralogy of Fallot the mean parental age and the birth order are not involved in the genesis of these lesions. A birth-order effect was only found in patent ductus arteriosus. First-born children are significantly affected more often than later-born siblings. The maternal as well as the paternal mean age is lower in this cardiac lesion. This suggests toward causative factors which may be present mainly during the first pregnancy and in primogenitures. Hypoxia could be one of these factors. If is postulated that in the presence of a polygenetically determined predisposition to this condition hypoxia may prevent closure of the ductus arteriosus. These investigations show that the original method of Haldane-Smith cannot be used for the analysis of the birth order effects on congenital malformations of the heart since the sibships are often incomplete. A corrective method described by Vogel is a good aid for such investigations.

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Zusammenfassung Bei einer Reihe häufiger Herzfehler—valvulären Aortenstenosen, Aortenisthmusstenosen, Pulmonalstenosen, Vorhof-und Ventrikelseptumdefekten und der Fallotschen Tetralogie—sind das elterliche Alter sowie die Stellung in der Geburtenreihe nach unseren Untersuchungen ohne Bedeutung für die Mißbildungsentstehung. Dagegen haben wir das Vorliegen eines Geburtenordnungseffektes beim Ductus arteriosus Botalli bestätigen können. Erstgeborene Kinder werden signifikant häufiger betroffen. Es ist sowohl das durchschnittliche Alter der Probandenväter als auch das der Mütter herabgesetzt. Daraus darf man folgern, daß weder ein väterlicher noch ein mütterlicher Effekt, sondern vielmehr ein Effekt, der mit der Erstschwangerschaft und Erstgeburt als solcher zusammenhängt, vorliegt. Als Erklärung hierfür bietet sich die Sauerstoffmangelhypothese an. Ein relativer Sauerstoffmangel post partum ist vermutlich am besten geeignet, bei entsprechender polygen determinierter Erkrankungsbereitschaft den Schließungsprozeß des Ductus arteriosus Botalli zu hemmen.Aus unseren Untersuchungen hat sich weiterhin ergeben, daß das Originalverfahren von Haldane-Smith für Untersuchungen der Geburtenordnung bei angeborenen Herzfehlern ungeeignet ist, da in den Familien der Probanden die Geschwisterreihen öfter nicht abgeschlossen sind, was eine Voraussetzung für die Anwendung dieser Methode ist. Dagegen bewährt sich eine Korrektur des Haldane-Smith-Verfahrens für unabgeschlossene Geschwisterreihen nach Vogel.

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This investigation was supported by the Deutsche Forschungsgemeinschaft, SFB 89 Kardiologie.     

Effects of Feed Contaminant Deoxynivalenol on Plasma Cytokines and mRNA Expression of Immune Genes in the Intestine of Broiler Chickens

An experiment was conducted to investigate the individual and combined effects of dietary deoxynivalenol (DON) and a microbial feed additive on plasma cytokine level and on the expression of immune relevant genes in jejunal tissues of broilers. A total of 40 broiler chicks were obtained from a commercial hatchery and divided randomly into four groups (10 birds per group). Birds were reared in battery cages from one day old for 5 weeks. The dietary groups were 1) control birds fed basal diet; 2) DON group fed basal diet contaminated with 10 mg DON/ kg feed; 3) DON + Mycofix group fed basal diet contaminated with 10 mg DON/ kg feed and supplemented with a commercial feed additive, Mycofix® Select (MS) (2.5 kg/ton of feed); 4) Mycofix group fed basal diet supplemented with MS (2.5 kg/ton of feed). At 35 days, the plasma levels of tumor necrosis factor alpha (TNF-α) and interleukin 8 (IL-8) were quantified by ELISA test kits. Furthermore, the mRNA expression of TNF-α, IL-8, IL-1β, interferon gamma (IFNγ), transforming growth factor beta receptor I (TGFBR1) and nuclear factor kappa-light-chain-enhancer of activated B cells 1 (NF-κβ1) in jejunum were quantified by qRT-PCR. The results showed that the plasma TNF-α decreased in response to DON, while in combination with MS, the effect of DON was reduced. DON down-regulated the relative gene expression of IL-1β, TGFBR1 and IFN-γ, and addition of MS to the DON contaminated diet compensates these effects on IL-1β, TGFBR1 but not for IFN-γ. Furthermore, supplementation of MS to either DON contaminated or control diet up-regulated the mRNA expression of NF-κβ1. In conclusion, DON has the potential to provoke and modulate immunological reactions of broilers and subsequently could increase their susceptibility to disease. The additive seemed to have almost as much of an effect as DON, albeit on different genes.     

Asymmetrical intraspecific competition in <Emphasis Type="Italic">Echinochloa crus</Emphasis>-<Emphasis Type="Italic">galli</Emphasis> is related to differences in the timing of seedling emergence and seedling vigour

Individual size is an important factor that determines fitness in annual plants. Variation in size originates at the seedling stage based on differences in seedling vigour and time of emergence, ensuing asymmetrical intraspecific competition between early- and late-established plants. The effects of the order of seedling emergence on characteristics of barnyard grass (Echinochloa crus-galli) were studied. In the first experiment, competition between pairs of plants, one of which was sown and emerged 0, 3, 6 or 12 days earlier than the other, was determined. In the second experiment, competition between two plants that were sown at the same time, but emerged at different times because of variation in seed quality, was determined. Competition decreased plant mass, tillering, height and the number of caryopses per panicle, but not time to earing or root/shoot ratio. Plants that were sown 3 days after the first plants in competing pairs grew to 32% of the size of solitary control plants, with the effect of competition accounting for 40% and asymmetrical competition 28% of the total reduction in size. When a 3-day lag in germination was determined intrinsically, plant size was reduced to 19% of the control, with the effect of competition accounting for 34%, asymmetrical competition 15% and poor intrinsic quality of the plant 32% of the total reduction in size. Small environmentally induced delays and more importantly, intrinsically induced delays in the time of emergence result in a considerable decrease in final plant size and fitness.