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.     

Lymphocyte survival and macrophage growth in long term in vitro leucocyte cultures

Zusammenfassung Unterschwellige Dosen von Phytohämagglutinin verlängern die Lebensdauer von Lymphozyten in menschlichen Zellkulturen, vermindern die Zahl der Makrophagen in der Kultur und erhöhen die Zahl der transformationsfähigen Lymphozyten.     

Detection of factor VIII related antigens in long term cultures of rat endothelial cells

Summary Rat endothelial cells in culture can be distinguished from fibroblasts and epithelial cells by their reaction with antisera against human factor VIII (AHF) associated proteins.The data form part of the Ph.D. thesis submitted by A.T. Darnule to the Department of Biology, New York University. Supported in part by NIH USPHS Program Project grant HL15832.     

Evidence of long memory in short‐term interest rates

The issues of non‐stationarity and long memory of real interest rates are examined here. Autoregressive models allowing short‐term mean reversion are compared with fractional integration models in terms of their ability to explain the behaviour of the data and to forecast out‐of‐sample. The data used are weekly observations of 3‐month Eurodeposit rates for 10 countries, adjusted for inflation, for 14 years. Following Brenner, Harjes and Kroner, the volatility of these rates is shown to both exhibit GARCH effects and depend on the level of interest rates. Although relatively little support is found for the hypothesis of mean reversion, evidence of long memory in interest rate changes is found for seven countries. The out‐of‐sample forecasting performance for a year ahead of the fractional integrated models was significantly better than a no change. Copyright © 2003 John Wiley & Sons, Ltd.     

Increased aggression in rats after withdrawal of long term used oxazepam

Summary The withdrawal of oxazepam (5 mg/kg i.p.) applied for 1 year in rats, increased shock-induced aggression of animals. This phenomenon is interpreted as a sign of abstinence and suggests that long-term treatment causes dependence to oxazepam in rats.Acknowledgment. Authors express their gratitude to Polfa, Warszawa, for the generous supply of oxazepam.     

Alteration of enzyme activities in detached leaves and their counteraction by kinetin

Zusammenfassung In abgetrennten Blättern werden verschiedene Enzyme, besonders aber die Pentosephosphatcyclus-Dehydrogenasen aktiviert. Gleichzeitig steigt die Atmungsintensität an. Die Malonatsensitivität der O₂-Aufnahme nimmt ab. Die Ausbildung der obigen Stoffwechsellage kann durch Kinetin gehemmt werden.     

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.     

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.

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

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.

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

The influence of long term estrogen treatment on plasma prolactin levels induced by ether anesthesia in ovariectomized rats

Summary 2 methods of continuous estrogen delivery, polyestradiol phosphate injection and implantation of Silastic capsules of estradiol-17 , in ovariectomized rats induced increases in plasma prolactin in the afternoon (15.00–17.00) beginning at 1 week and continuing for 4–8 weeks. In addition these methods of estrogen treatment potentiated the ether-induced increase in plasma prolactin in the morning (9.00–11.00) beginning on week 2 and continuing for 3–8 weeks. These results indicate that estrogen activates the mechanisms that cause an afternoon surge in prolactin before potentiating a morning elevation induced by ether anesthesia.Acknowledgment. This work was supported by NIH General Research Support, grant No. RR05384-14 to Wayne State University School of Medicine. The authors also with to express their appreciation to Mrs C. Van De Walle for her expert technical assistance in the prolactin radioimmunoassay, to Dr Richard R. Gala for his advice and support of this project and to the Rat Pituitary Hormone Distribution Program of NIAMDD for the generous gift of Rat Prolactin.     

Regulation of nicotine biogenesis 2: Increased production of nicotine by urea in tobacco tissue cultures

Summary The floral bud callus ofNicotiana tabacum L. was successfully grown on 10 mM urea as sole nitrogen source. Nicotine content in the urea-treated tissues was 3.5 times higher than in the control on the basis of dry weight, and 2.5-fold higher per culture. Contents of ornithine, citrulline and arginine, urea cycle intermediates, and known precursors of nicotine, were higher in urea-treated callus. The implications of the results are discussed.Financial support given to one of us (GAR) by the Maharaja Sayajirao University of Barado is gratefully acknowledged. Reference No. represents part 1 of the series on regulation of nicotine biogenesis.     

Changes in the distribution of glucose-14C in alternative catabolic pathways induced by kinetin-analogue in the callus tissue of carrot (Daucus carota L.)

Zusammenfassung Im Callusgewebe vonDaucus carota L. wurde mittels speziell markierter Glucose nach 6stündiger Behandlung mit 6-Benzylaminopurin (0,2–4,0 mg/l) der vergrösserte Anteil der Atmung vom glycolytischen Typ festgestellt.