Non-specific esterases in females ofAedes aegypti (L.)

Zusammenfassung Unspezifische Esterasen wurden während des Adultlebens vonAedes aegypti (L.) quantitativ bestimmt und zwischen Weibchen von 2 Stämmen verglichen. Alterungist begleitet von einer Zunahme der Bänderzahl und einer Abnahme der Esterasenaktivität pro Weibchen; die relative Aktivität der einzelnen Esterasen-Isozyme bleibt aber mehr oder weniger konstant. Nach einem Blutmahl, dem Beginn eines neuen gonotrophen Zyklus, wurden auffällige Veränderungen im Bändermuster festgestellt. 4 Tage später, nach erfolgter Eiablage, ist dieses Muster wieder ähnlich wie vor der Blutaufnahme.     

Establishment of two mosquito cell lines from larval tissues ofAedes w-albus

Zusammenfassung Zwei neue Zellinien vonAedes w-albus, die seit der Isolation schon 27 bzw. 37mal kultiviert wurden, sind isoliert worden. Die Zellen konnten 45 Tage in flüssigem Stickstoff aufbewahrt werden, ohne ihre Vermehrungsfähigkeit einzubüssen.     

Stimulation of growth by insulin inDrosophila embryonic cells in vitro

Summary For obtaining a better yield of established lines of embryonicDrosophila cells, insulin proved to be a useful substance to be added to the culture medium. 10% of lines became established, showing a predominatly diploid chromosome number.     

From pluripotency to forebrain patterning: an in vitro journey astride embryonic stem cells

Embryonic stem cells (ESCs) have been used extensively as in vitro models of neural development and disease, with special efforts towards their conversion into forebrain progenitors and neurons. The forebrain is the most complex brain region, giving rise to several fundamental structures, such as the cerebral cortex, the hypothalamus, and the retina. Due to the multiplicity of signaling pathways playing different roles at distinct times of embryonic development, the specification and patterning of forebrain has been difficult to study in vivo. Research performed on ESCs in vitro has provided a large body of evidence to complement work in model organisms, but these studies have often been focused more on cell type production than on cell fate regulation. In this review, we systematically reassess the current literature in the field of forebrain development in mouse and human ESCs with a focus on the molecular mechanisms of early cell fate decisions, taking into consideration the specific culture conditions, exogenous and endogenous molecular cues as described in the original studies. The resulting model of early forebrain induction and patterning provides a useful framework for further studies aimed at reconstructing forebrain development in vitro for basic research or therapy.     

Morphological effects of concanavalin A on amphibian embryonic cells differentiating in vitro (author's transl)]

Concanavalin A exerts an irreversible inhibitory effect on the differentiation of cultured embryonic amphibians cells in vitro. Cytological changes and distrubances of cell attachment, and spreading to the culture support occur in parallel. Polykaryons have been noticed in treated cultures.     

DNA repair mechanisms in embryonic stem cells

Embryonic stem cells (ESCs) can undergo unlimited self-renewal and retain the pluripotency to differentiate into all cell types in the body. Therefore, as a renewable source of various functional cells in the human body, ESCs hold great promise for human cell therapy. During the rapid proliferation of ESCs in culture, DNA damage, such as DNA double-stranded breaks, will occur in ESCs. Therefore, to realize the potential of ESCs in human cell therapy, it is critical to understand the mechanisms how ESCs activate DNA damage response and DNA repair to maintain genomic stability, which is a prerequisite for their use in human therapy. In this context, it has been shown that ESCs harbor much fewer spontaneous mutations than somatic cells. Consistent with the finding that ESCs are genetically more stable than somatic cells, recent studies have indicated that ESCs can mount more robust DNA damage responses and DNA repair than somatic cells to ensure their genomic integrity.     

Inactivation of vasotocin by hen's tissues in vitro

Zusammenfassung In vitro wurde die Inaktivation von Vasotocin in einigen Gewebehomogenaten (Leber, Niere, Eileitersegmenten, Magnum, Isthmus Uterus, Vagina) festgestellt. Die grösste Inaktivation wurde bei den Homogenaten von Leber und Utersus gefunden.     

Morphological effects of serotonin and ketanserin on embryonic chick skin in vitro

Summary Cell and organotypical cultures are used to study the direct effect of serotonin and of ketanserin, a serotonin antagonist, on dermal and epidermal cells of embryonic chick skin. Ketanserin stimulates the increase in cell number and inhibits the differentiation, whereas serotonin stimulates differentiation and inhibits the increase in cell number.     

Morphological effects of serotonin and ketanserin on embryonic chick skin in vitro

Cell and organotypical cultures are used to study the direct effect of serotonin and of ketanserin, a serotonin antagonist, on dermal and epidermal cells of embryonic chick skin. Ketanserin stimulates the increase in cell number and inhibits the differentiation, whereas serotonin stimulates differentiation and inhibits the increase in cell number.     

Effects of thyrotropin and thiouracil on embryonic chick thyroidin vitro

Zusammenfassung Schilddrüsenanlagen von Hühnerembryonen, in Ambinon-Medium kultiviert, entwickeln sich schneller und zeigen beschleunigte intrafollikuläre Kolloidbildung. Mit Thiourazil behandelte Kulturen liessen retardierte Follikelbildung und Kolloidbildung erkennen.