Synaptogenesis in hippocampal cultures

Hippocampal cultures offer unique advantages for the study of neuronal development and synaptogenesis. Studies performed on this model enabled dissection of the temporal sequence of events which lead to the differentiation of pre- and postsynaptic compartments. Received 27 January 1999; received after revision 4 March 1999; accepted 5 March 1999     

Ethylene effects on tissue cultures ofNicotiana tabacum

Riassunto Si è studiato l'effetto dell'etilene su culture di cellule diNicotiana tabacum, in vitro. I risultati ottunuti mostrano che le auxine in presenza di etilene inibiscono la crescita di frammenti di callus, e che tale inibizione viene rimossa dalla kinetina.

---

---

The author thanks Prof.G. Montalenti and Prof.G. Morpurgo for discussions andG. Conti for excellent technical assistance.     

Effects of carmine and carminic acid on embryonic tissue cell cultures

The biological reaction to carmine and carminic acid at cellular level on 'in vitro' cultures was tested and significant variables were controlled. Results suggested that proliferation and metabolism of these cultures were not affected by the 2 stains.     

Effects of carmine and carminic acid on embryonic tissue cell cultures

Summary The biological reaction to carmine and carminic acid at cellular level on in vitro cultures was tested and significant variables were controlled. Results suggested that proliferation and metabolism of these cultures were not affected by the 2 stains.     

Induced regeneration of plants in tissue cultures ofBrassica oleracea

Résumé Dans les cultures de tissus repiqués de Chou moellier une néoformation de plantes entières se produit en conséquance de l'exclusion du 2,4-D du milien de culture.

---

---

We thank Miss A.temberová and Mrs. M.Paldusová for valuable technical assistance.     

The effects of radiation on enzymes in tissue cultures

Riassunto Colture primarie di rene di scimmia (M. rhesus) presentano, dopo l'irradiazione, un aumento nell'attività della fosfatasi alcalina, mentre l'attività della fosfatasi acida non risulta modificata.     

Vegetative propagation of the cactusMamillaria woodsii craig through tissue cultures

Summary A new method of clonal multiplication is described in a representative from the Cactaceae family, which offers wide experimental and horticultural applications.     

Actions of interferon in tissue cultures harboring mouse leukemia virus

Zusammenfassung Das Virus der vesikulären Stomatitis verursacht Zellverschmelzung und Syncytienbildung in mit Mäuse-Leukämie-Virus infizierten Gewebskulturen. Interferon konnte diese Zellzerstörung in der Kultur nicht verhindern.

---

---

This work was supported by U.S.P.H.S. research grant No. CA-7923 and award No. K3-CA-16747.     

Decontamination of pleuropneumonia-like organism (PPLO) infected tissue cultures

Zusammenfassung PPLO-verunreinigte Zellkulturen wurden mit Novobiocin® PPLO-eliminierend behandelt. Nach dem Empfindlichkeitstest folgte die Bestimmung der Toxizität dieses Antibiotikums für Gewebekulturzellen. Anschliessend wurden maximale, für Zellen nichttoxische Konzentrationen verwendet. Die entwickelte Methode ermöglicht, den Wirkungsgrad dieser antibiotischen Behandlung zu bestimmen.     

Kinetin/Auxin ratio and development of chloroplasts in tissue cultures ofDaucus carota

Riassunto Nell'intento di stabilire i fattori responsabili del differenziamento dei cloroplasti in culture di tessuto diDaucus carota, sono stati eseguiti esperimenti al fine di scegliere tra le 3 ipotesi possibili: la chinetina stimola la formazione dei cloroplasti; le auxine inibiscono la formazione dei cloroplasti; il differenziamento dei cloroplasti dipende dal rapporto chinetina/auxina, indipendentemente dalla quantità assoluta dei 2 ormoni. Sidimostra che quest'ultima ipotesi é corretta.