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.     

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.     

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.     

Differential effects of accumbens core vs. shell lesions in a rat concurrent conditioned place preference paradigm for cocaine vs. social interaction

Background

A main challenge in the therapy of drug dependent individuals is to help them reactivate interest in non-drug-associated activities. Among these activities, social interaction is doubly important because treatment adherence itself depends on it. We previously developed a rat experimental model based on the conditioned place preference (CPP) paradigm in which only four 15-min episodes of social interaction with a gender- and weight-matched male conspecific (i) reversed CPP from cocaine to social interaction despite continuing cocaine training and (ii) prevented the reinstatement of cocaine CPP. In the present study, we investigated if the two subregions of the nucleus accumbens (Acb), i.e., the core (AcbC) and the shell (AcbSh), would differentially affect CPP for cocaine vs social interaction.

Methodology/Principal Findings

Animals were concurrently trained for CPP pairing cocaine with one compartment and social interaction with the other (i.e., mutually exclusive stimulus presentation during training). Excitotoxic lesioning of the AcbC or the BLA shifted CPP toward social interaction, whereas AcbSh inactivation shifted CPP toward cocaine.

Conclusions

Overall, our findings suggest that inactivation of the AcbC or the BLA is sufficient to shift CPP away from a drug of abuse toward social interaction. Lesioning the AcbSh produced the opposite effect.     

Arthropod community of dandelion (Taraxacum officinale) capitula during seed dispersal

Dandelion (Taraxacum officinale) is an abundant Asteraceae species of grassland and vasteland stands. Through the vegetative season each plant produces a number of short-lived inflorescens. Final stage of inflorescence development is seed dispersal that lasts 2 days. Despite its ephemeral persistence, inflorescences at this period host abundant fauna. In 2005–2010 the inflorescences were collected in regular intervals in May–October, at Prague-Ruzyně and selected sites of western Czech Republic. Typical fauna consist of Heteroptera adults and larvae (34 species), phytophagans feeding on receptacle and seeds (mainly Miridae, Pentatomidae, Rhopalidae) and predators consuming thrips (Anthocoridae). The composition of Heteroptera fauna varies through the vegetative season, and its abundance decreases with increasing altitude of the locality. Other fauna are relics of species consuming seeds in the post-flowering phase of inflorescence maturation (mainly Thysanoptera) and occasional visitors with no trophic relationship to dandelion (Coleoptera, Diptera, Hymenoptera, Araneae). The reasons for association of phytophagous Heteroptera and dandelion may be preferences for seed consumption and chemicals present in plant tissues and possibly used for sequestration of aposematic substances.     

Continuous capture of recombinant antibodies by ZnCl2 precipitation without polyethylene glycol

The capture of recombinant antibodies from cell culture broth is the first critical step of downstream processing. We were able to develop a precipitation‐based method for the capture and purification of monoclonal antibodies based on divalent cations, namely ZnCl₂. Traditional precipitation processes have to deal with high dilution factors especially for resolubilization and higher viscosity due to the use of PEG as precipitation or co‐precipitation agent. By the use of the crosslinking nature of divalent cations without the use of PEG, we kept viscosity from the supernatant and resolubilization dilution factors very low. This is especially beneficial for the solid–liquid separation for the harvest and wash of the precipitate in continuous mode. For this harvest and wash, we used tangential flow filtration that benefits a lot from low viscosity solutions, which minimizes the membrane fouling. With this precipitation based on ZnCl_2, we were able to implement a very lean and efficient process. We demonstrated precipitation studies with three different antibodies, Adalimumab, Trastuzumab, and Denosumab, and a continuous capture case study using tangential flow filtration for precipitate recovery. In this study, we achieved yields of 70%.     

New Insights on Cytological and Metabolic Features of Ostreopsis cf. ovata Fukuyo (Dinophyceae): A Multidisciplinary Approach

The harmful dinoflagellate Ostreopsis cf. ovata has been causing toxic events along the Mediterranean coasts and other temperate and tropical areas, with increasing frequency during the last decade. Despite many studies, important biological features of this species are still poorly known. An integrated study, using different microscopy and molecular techniques, Raman microspectroscopy and high resolution liquid chromatography-mass spectrometry (HR LC-MS), was undertaken to elucidate cytological aspects, and identify main metabolites including toxins. The species was genetically identified as O. cf. ovata, Atlantic-Mediterranean clade. The ultrastructural results show unique features of the mucilage network abundantly produced by this species to colonize benthic substrates, with a new role of trichocysts, never described before. The amorphous polysaccharidic component of mucilage appears to derive from pusule fibrous material and mucocysts. In all stages of growth, the cells show an abundant production of lipids. Different developmental stages of chloroplasts are found in the peripheral cytoplasm and in the centre of cell. In vivo Raman microspectroscopy confirms the presence of the carotenoid peridinin in O. cf. ovata, and detects in several specimen the abundant presence of unsaturated lipids structurally related to docosahexaenoic acid. The HR LC-MS analysis reveals that ovatoxin-a is the predominant toxin, together with decreasing amounts of ovatoxin-b, -d/e, -c and putative palytoxin. Toxins concentration on a per cell basis increases from exponential to senescent phase. The results suggest that benthic blooms of this species are probably related to features such as the ability to create a unique mucilaginous sheath covering the sea bottom, associated with the production of potent toxins as palytoxin-like compounds. In this way, O. cf. ovata may be able to rapidly colonize benthic substrates outcompeting other species.