In vitro differentiation of primitive molar tissue from mouse embryo]

The developing molar tissues of the lower jaw of 13, 14 and 15 day Mouse embryos were removed and cultured in vitro. Complete molar dentition differentiated.     

In vitro malignant transformation of fetal hamster brain cells by methylnitrosourea]

Using primary cultures originating from 14 day old fetal Hamster brain, we have obtained a cell line with glial morphology. These cell remain non transplantable during the first year of in vitro culture, but undergo spontaneous transformation during the second year. Following prolonged contact of the glial-like cells with 25 to 50 microgram/ml of methylnitrosourea (MNU), a malignant transformation is observed 5 months after the treatment. The lowest concentrations of (MNU) do not cause malignant transformation, but seem to inhibit (or postpone) the spontaneous transformation. After MNU treatment, cells retain their glial nature.     

Catecholamine biosynthesis in vascular tissue

Zusammenfassung Die Umwandlung von Tyrosin in Katecholamin wurde in verschiedenen Blutgefässen untersucht. Die Katecholamin-Biosynthese erfolgte am schnellsten in der Arteria mesenterica sup. (0,6 g/g/h), was zehnmal höher liegt als diejenige in der Aorta oder in der Arteria pulmonalis.     

Effect of sulpiride on oxygen uptake by rat's brain tissue in vitro

Resumen El Sulpiride in vitro a la concentración de 1×10^–2 M disminuye el consumo de Oxígeno en cortes de cerebro de rata. El exceso de potasio o ausencia de calcio en el medio de incubación, no modifican este efecto. En homogeneizado de cerebro total, unicamente a la concentración de 1×10^–2 M deprime el consumo de oxígeno. A las concentraciones 1×10^–3 y 1×10^–4 M no modifica el consumo de oxígeno en cortes ni homogeneizados de cerebro.     

Effect of Ketamine hydrochloride on oxygen and glucose uptake by brain tissue in vitro

Resumen El clorhidrato de Ketamina (1×10^–3 M y 1×10^–4 M) incrementa el consumo de oxigeno de cortes de cerebro de rata incubados en Krebs-Ringer fosfato conteniendo 5 mM ó 100 mM de potasio. La droga no modifica el consumo de oxigeno de homogeneizado de cerebro total.     

Collagen biosynthesis in vitro and the consequences of bacterial contamination. Studies on vascular connective tissue in rabbits

Zusammenfassung Mit Bakterien im Inkubationsmedium wurde eine 10-bis 15-fache Erhöhung der¹⁴C-Prolin-Inkorporation und eine stimulierende Wirkung der¹⁴C-Hydroxyprolin-Synthese gefunden. Diese Beobachtungen zeigen, dass sterile Bedingungen notwendig sind, um falsche Schlussfolgerungen durch die Untersuchung des Kollagenmetabolismus mit¹⁴C-Prolin-Bildung in vitro zu vermeiden.     

In vitro studies on the biosynthesis of a glycoprotein associated with normal and tumoural growth in the rat

Résumé La biosynthèse d'une glycoprotéine, isolée à partir d'une tumeur induite au 2-amino-acetylfluorène, a été étudiée in vitro, par la culture de la moëlle osseuse du rat, du poumon et du foie embryonnaire. Cette étude a été faite à l'aide d'acides aminés radioactifs dans le milieu et, subséquemment, par radio-immunoélectrophorèse. Le dosage quantitatif de la biosynthèse in vitro, par les tissus, a été fait par la méthode électrophorétique d'agarose contenant un anticorps monospécifique préparé chez la chèvre, contre la glycoprotéine pure. La spécificité de la méthode a été éprouvée en utilisant, comme contróle, l'incubation des tissus morts et en ajoutant de la puromycine dans le milieu.

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Investigation supported by the National Cancer Institute of Canada and by the Medical Research Council of Canada     

In vitro malignant transformation of hamster lung cells by 2-chlorobutadiene]

Normal Hamster lung cells from an established line were treated with 1-500 microgram . ml-1 2-chlorobutadiene. Those treated with 1 microgram . ml-1 of the compound showed malignant transformations 14 weeks after treatment. The treatment with higher concentrations did not accelerate the transformation process.     

Transplantation of brain tissue in the brain of adult rats

Summary Brain tissues obtained from rat embryos were transplanted in the forebrain and/or cerebellum of the adult rats. The transplants survived, grew and achieved normal cellular and cytoarchitectural differentiation. They had become anatomically integrated with the host brain. The animals did not show any obviously detectable abnormal behavior or pathology of the brain. The transplants survived as long as the animals did suggesting that they had become a part and parcel of the host brain.Supported by research grants NS-08817 and CA-14650 from N.I.H.     

An alternative route for biosynthesis of methylhistamine: In vitro and in vivo formation through decarboxylation ofl-3-methylhistidine

Résumé On a mis en évidence chez le Rat une formation de méthylhistamine-³H par décarboxylation de lal-3-méthylhistidine-³H. Cette réaction se produit in vitro et in vivo dans des tissus riches en histidine décarboxylase et elle est prévenue par un inhibiteur de cette enzyme. Les implications biologiques de l'existence de cette nouvelle voie métabolique sont envisagées.     

In vitro release of free fatty acids by adipose tissue in young and old nephrotic rats

Zusammenfassung Bei nephrotischen Ratten verschiedenen Alters wurdein vitro die Abgabe freier Fettsäuren aus dem Fettgewebe untersucht. Bei jungen Tieren war letztere am grössten, der Fettgehalt des Gewebes am niedrigsten. Diese Resultate stimmen mit an normalen Tieren gewonnenen überein und stützen die Ansicht, dass die nephrotische Lipämie nicht durch Mobilisation des Depotfettes entsteht.

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Supported in part by grant G-13084 from the National Science Foundation.     

Modification of human adenovirus type 7 after culture in guinea pig brain cells in vitro]

Multiplication of human adenovirus 7 (Ad7) is restricted in subcultures of adult Guinea Pig brain cells. It was however possible to recover enough infectious virus to purify it, and to study its properties. Several properties are similar to that of Ad 7 produced in HeLa cells but differences in sensitivity to cesium chloride and in its polypeptide composition were found.     

Immunofluorescent localization of beta-lipotropin (beta-LPH) and beta-endorphins in normal and anencephalic human fetal pituitary gland]

The use of antibodies to alpha-(17-39) ACTH, beta-LPH, alpha- and beta-endorphins has enabled the detection of immunoreactive cells in human fetal pituitary glands as early as the eight week of gestation. The same cells reacted with the different antibodies. Immunoreactive cells were also observed in the pituitary of 6 human anencephalic fetuses.     

Culture of nucellar tissue ofCitrus in vitro

Zusammenfassung Wucherungen, die in der vorliegenden Arbeit als «Pseudobulbillen» bezeichnet worden sind, erschienen zuerst in Kulturen vonCitrus-Nucellargewebe auf einem künstlichen Nährboden. Diese Bulbillen sind durch zahlreiche Passagen in einem genau definierten Nährboden seit einem Jahr erhalten geblieben.     

RNA biosynthesis in isolated prothoracic glands ofTenebrio molitor in vitro

Summary The prothoracic Glands ofTenebrio molitor synthesize in vitro mainly rRNA. The rate of RNA synthesis reaches a maximum at day 10 of the last larval instar, which coincides with the event of apolysis.The work was supported by the Deutsche Forschungsgemeinschaft. We thank Dr.H. Winter, Heidelberg, for helpful suggestions for the RNA separations.     

In vitro comparison of antigraft protection mechanisms in 2 genera of lumbricians: Eisenia and Lumbricus]

We sum up our in vitro experiments on allograft reactions in 2 genera of Lumbricians: Eisenia and Lumbricus. In Eisenia, first this reaction is a non-specific humoral one, then it becomes a specific cellular reaction. In Lumbricus the allograft reaction is a specific, mostly cellular one. Nevertheless it interferes with an acquired, specific humoral reaction.     

Stimulation of the in vitro biosynthesis of corticosteroids by angiotensin II

Zusammenfassung In Rindenschnitten frischer Rindernebennieren stimulierte Angiotensin II den Einbau von 1-C¹⁴-Acetat in Mineralo- und Glukocorticosteroide, hatte jedoch keinen Effekt auf die Transformation von 4-C¹⁴-Cholesterin und 4-C¹⁴-Progesteron. Der Angriffspunkt des Angiotensins scheint danach in Synthesebereichen vor der Cholesterinbildung zu liegen.     

Freezing and transplantation of brain tissue in rats

Summary Neocortical tissue obtained from rat embryos was frozen and stored at –70°C for 6 h prior to transplantation into the cerebellum of neonatal rats. Growth, differentiation, and integration of this tissue within the host brain was comparable to that obtained from freshly dissected and transplanted tissue. It is suggested that freezing to low temperatures does not adversely effect the viability or transplantability of the neural tissue.Supported by N.I.H. research grants Nos NS-08817 and CA-14650.