Histochemical demonstration of differences in AMP deaminase activity in rat skeletal muscle-fibres

The histochemical method for AMP deaminase confirms that rat slow-twitch fibres contain less AMP deaminase activity than fast-twitch fibres. However, the enzyme appears similarly localized in all fibre types.     

Materials: carbon nanotubes in an ancient Damascus sabre

The steel of Damascus blades, which were first encountered by the Crusaders when fighting against Muslims, had features not found in European steels--a characteristic wavy banding pattern known as damask, extraordinary mechanical properties, and an exceptionally sharp cutting edge. Here we use high-resolution transmission electron microscopy to examine a sample of Damascus sabre steel from the seventeenth century and find that it contains carbon nanotubes as well as cementite nanowires. This microstructure may offer insight into the beautiful banding pattern of the ultrahigh-carbon steel created from an ancient recipe that was lost long ago.     

Dendritic reticulum cells in AIDS-related lymphadenopathy

One of two cases of acquired immune deficiency syndrome-related persistent generalized lymphadenopathy revealed a profoundly altered pattern of dendritic reticulum cells as demonstrated by immunoreactive acid cysteine proteinase inhibitor. The alterations could be related to totally or partially destructed lymphoid secondary follicles.     

Actions ofl-glutamate,acetylcholine and dopamine on single neurones in the nuclei cuneatus and gracilis of the cat

Zusammenfassung Von 250 Neuronen im Gebiet des Nucleus cuneatus und des Nucleus gracilis der Katze wurden 132 durch periphere physiologische Reizung aktiviert und 6 gehemmt. Mit Hilfe der Mikroelektrophorese wurden die folgenden Substanzen in die unmittelbare Nähe dieser Neurone gebracht:l-Glutaminsäure aktivierte 50 % der Neurone. Acetylcholin war nur an wenigen Zellen im Kerngebiet wirksam, von diesen wurden 2 gehemmt und 3 aktiviert. Dopamin hemmte die Mehrzahl der durch periphere Reizung becinflussbaren Neurone.     

Inhibition of isoprenaline-induced increase in plasma renin concentration by vasoconstrictors.

The vasoconstrictors angiotensin II, vasopressin and the alpha-sympathomimetic phenylephrine significantly inhibit the renin release caused by the beta-sympathomimetic isoprenaline. The mechanism of the inhibition is discussed.     

Corticotropin releasing factor induction of leukocyte-derived immunoreactive ACTH and endorphins

Human peripheral leukocytes infected by virus or treated with endotoxin will, like unstimulated mouse spleen macrophages, synthesize immunoreactive corticotrophin (ir-ACTH) and endorphins. The ir-ACTH produced appears to be identical with authentic ACTH, while enough of the material has been produced in hypophysectomized mice infected with virus to demonstrate a steroidogenic response. Because the production of ACTH by in vivo pituitary cells and by leukocytes is suppressed by dexamethasone both in vitro and in vitro, suggesting that the production of ACTH and endorphins by leukocytes is indeed controlled, we have investigated the effects of corticotropin releasing-factor (CRF), which is known to regulate the pituitary production of both ACTH and beta-endorphin. We now report that the production of ACTH and endorphins by leukocytes is indeed induced by synthetic CRF and, in turn, suppressed by dexamethasone, suggesting that, as in pituitary cells, the proopiomelanocortin (POMC) gene may be expressed and similarly controlled in leukocytes.