Evidence for an olfactory receptor which responds to nicotine — nicotine as an odorant

Summary The tobacco alkaloid (S)(–)-nicotine, when applied as a vapour to an in vitro head preparation, stimulates the olfactory epithelium in three strains of rats and to a lesser extent in two strains of mice. The electro-olfactogram (EOG) generated by nicotine has similar characteristics to the EOGs produced by known odorants. The nicotine EOG increases with increasing concentration of nicotine vapour (1–100 nM) applied to the olfactory epithelium.Differential reduction of the nicotine EOG by the lectin concanavalin A is seen in Wistar and Lister Hooded rats. The reduction of the nicotine EOG by concanavalin A is prevented by adding alpha-methyl-D-mannoside to the lectin superfusion medium. This suggests that there is a glyco-moiety associated with at least one olfactory receptor responding to nicotine.Our results suggest that rat olfactory epithelium has receptor sites for nicotine. Nicotine is an unusual compound because it shows both odorant and pharmacological properties.22 September 1986     

Combining naturally occurring polyphenols with TNF-related apoptosis-inducing ligand: a promising approach to kill resistant cancer cells?

TNF-related apoptosis-inducing ligand (TRAIL) and its receptors are attractive targets for anticancer therapy owing to their ability to trigger apoptosis selectively in cancer cells but not in normal cells. To date, many combinatorial strategies, such as chemotherapy or radiotherapy, have given encouraging results for overcoming TRAIL resistance in preclinical models. In this review, we provide an overview of the molecular mechanisms underlying sensitization to TRAIL-induced apoptosis by polyphenols. These naturally occurring compounds can restore tumor cell sensitivity to TRAIL-induced cell death with no apparent toxicity towards normal cells. Both extrinsic and intrinsic pathways can be modulated by polyphenols, the activation of which largely depends on the cell type, the particular polyphenolic compound, and the conditions of treatment. The large variety of polyphenol cellular targets could prove useful in circumventing TRAIL resistance. The relevance of these combined treatments for cancer therapy is discussed in the light of recent preclinical studies.     

The effect of plant growth substances and natural products on RNA and DNA synthesis in leukocytes.

The effect of auxins, cytokinins, gibberellins and phenolics on the incorporation of uridine and thymidine into the nucleic acids of human leukocytes was examined. Both the stimulation and inhibition of the incorporation of the precursors was noted. The auxins consistently promoted the incorporation of uridine.     

Sex chromatin in an australian marsupialPerameles nasuta geoffroy, 1804

Résumé La chromatine sexuelle des cellules de l'epithelium corneal de mâles et femelles adultes du Marsupial australienParmeles nasuta Geoffroy a été étudiée. Les cellules des mâles comme celles des femelles manifestent l'existence de la chromatine sexuelle dans le noyau interphasique. Il n'y a pas de différence de taille entre chromatine sexuelle mâle et femelle.     

Oxidation of cholesterol by rat liver mitochondria: Influence of deuterium oxide

Résumé L'oxydation du cholestérol-26-¹⁴C et de l'octanoate de sodium-1-¹⁴C par une préparation de mitochondries de foie de rat a été effectuée en milieu aqueux à un pH de 8,5 et dans l'eau lourde (D₂O) à un pH de 8,1 et 8,5. La présence d'eau lourde a inhibé l'oxydation des deux substrats. L'oxydation du cholestérol dans l'eau lourde à un pH de 8,5 a été réduite de 60% à 70% de la valeur normale et de plus de 90 % dans l'eau lourde à un pH de 8,1. Aux deux valeurs de pH, l'oxydation de l'octanoate a été réduite de 50% à 70%.     

The structure of isothebaine

Zusammenfassung Beweismaterial wird vorgelegt, das entschieden darauf hindeutet, dass Isothebaïn-methyläther (+)-4:5:6-Trimethoxyaporphin und Isothebaïn (+)-5-Oxy-4:6-dimethoxyaporphin ist.     

Absence of low molecular weight DNA polymerase activity from the nuclei ofAmoeba discoides

Summary Amoeba discoides nuclear protein partially purified by passage through Sephadex G-200 showed 3 high-mol.-wt DNA polymerase activities which eluted in and just following the void volume. No low-mol.-wt (45,000 daltons) DNA polymerase activity was detected. Nuclear protein layered on 5–20% sucrose gradients also showed an absence of lowmol.-wt DNA polymerase . The void volume enzyme showed deoxyribonuclease activity, but no low-mol.-wt nuclease activity was detected.     

Mechanisms of inherited cancer susceptibility

A small proportion of many cancers are due to inherited mutations in genes, which result in a high risk to the individual of developing specific cancers. There are several classes of genes that may be involved： tumour suppressor genes, oncogenes, genes encoding proteins involved in DNA repair and cell cycle control, and genes involved in stimulating the angiogenic pathway. Alterations in susceptibility to cancer may also be due to variations in genes involved in carcinogen metabolism. This review discusses examples of some of these genes and the associated clinical conditions caused by the inheritance of mutations in such genes.