Oxidative deamination of biogenic amines by intestinal amine oxidases: histamine is specifically inactivated by diamine oxidase

The ability of the gut to inactivate various amines by oxidative deamination was tested with a 130-fold purified amine oxidase preparation from dog small intestine. Of 34 amines tested, putrescine, benzylamine, cadaverine, and serotonin were the most favourable substrates. Histamine was inactivated rapidly by this enzyme preparation, too. Histamine derivatives methylated at the imidazole nucleus were also deaminated, whereas Nalpha-methylhistamine was only a poor substrate and Nalpha, Nalpha-dimethylhistamine was not a substrate at all. Using a second procedure for the purification of amine oxidases from gut, the separation of a soluble monoamine oxidase from diamine oxidase was achieved by gel filtration on Sephadex G-200. The diamine oxidase deaminated putrescine (Km = 1.3 x 10(-4)M) and histamine (Km = 6.6 x 10(-5)M), but not serotonin, and was inhibited by aminoguanidine, but not by pargyline. The soluble monoamine oxidase inactivated serotonin (Km = 4.5 x 10(-4)M), but not histamine and putrescine and was inhibited by pargyline, but not by aminoguanidine. It was concluded that in dog small intestine (as well as in rabbit small intestine) only diamine oxidase was capable of inactivating histamine by oxidative deamination.

[Facial manifestations of suppurative trichophytosis]

Several cases of facial suppurative Trichophytia described by the authors lead to a review of the clinical, mycological and pathological features of this disorder which is on the increase in the region of Nantes.

Recurrent inhibition of individual Ia inhibitory interneurones and disinhibition of their target alpha-motoneurones during muscle stretches

The effects of ramp stretches applied to triceps surae muscle on the discharge patterns of single Ia inhibitory interneurones, monosynaptically invaded from various nerves, were studied in either decerebrate or anesthetized cats. Interneurones which received direct excitatory Ia input from the stretched muscle exhibited augmented activity both during the dynamic and static phase of stretch, which was, however, interrupted by a transient inhibitory influence during the dynamic phase of stretch. The influences on Ia inhibitory interneurones, monosynaptically invaded from hamstring or tibial nerve, were exclusively inhibitory. These stretch-induced inhibitions were better demonstrable in decerebrate than in anesthetized preparations. The timing of the discharge patterns of additionally recorded Renshaw cells during stretch, and the disappearance or reduction of the above described inhibitory effects after administration of DHE, strongly support the idea that these inhibitory actions are caused by Renshaw inhibition. In Ia inhibitory interneurones, monosynaptically activated from the antagonistic peroneal nerve, stretch induced also pronounced inhibitory effects, which were most probably caused by mutual inhibition between Ia inhibitory interneurones. The suppression of agonistic Ia inhibitory interneurone activity below the tonic resting activity corresponded to an enhancement of the monosynaptic reflex amplitude of the antagonistic motoneurone pool. The findings suggest that normal orthodromic activation of Renshaw cells, and consequently the recurrent inhibition of the Ia inhibitory interneurones, is predominantly linked with rapid phasic, rather than slow tonic, motoneuronal firing. The functional role of this mechanism for the performance of rapidly alternating movements and the damping of ballistic agonist contractions is discussed.

[Activation of the fibrinolytic system by furosemide (author's transl)]

Intravenously administered furosemide induces besides its well known diuretic effect a significant activation of the fibrinolytic system. This fibrinolytic effect, however, is only seen in persons with an intact renal system, not in nephrectomized patients and not in patients with chronic renal insufficiency. From this finding the conclusion is drawn that furosemide needs for its fibrinolytic effect the intact renal tissue. It is discussed that the beneficial therapeutic value of high-dose furosemide in acute renal insufficiency following shock or septic abortion might at least partially be due to furosemide-induced fibrinolysis of the microthrombi of the glomerula.

Correlation of the dynamic behaviour of deefferented primary muscle spindle endings with their static behaviour

20 deefferented primary muscle spindle endings, 8 afferents from the extensor digitorum longus muscle (EDL) and 12 from the tibialis anterior muscle (TA), were investigated in 12 anesthetized cats. Dynamic responses of muscle spindles to ramp stretches were correlated with their static responses. The variation in the state and dynamic behaviour was found to be interdependent. The correlation coefficients were higher for EDL spindles than for TA spindles. The correlation coefficients depended upon the definition of the dynamic responses.

[A rare dental abnormality: "the phantom tooth" or "odontodysplasia". Apropos of a case]

"Phantom tooth" or "odontodysplasia" is one of the most unusual and rare of dental abnormalities, being characterised: Clinically, by the topography of the lesions, the involvement of both sets of teeth and abnormalities in the size and form of the teeth which remain unrupted or only partially evolved. Radiologically, by transparency of the teeth to X-rays. Histologically, by disorganisation of the dental structures and a highly characteristic appearance of the enamel and, in particular, dentine. On the basis of one case, the authors review in detail each aspect of these characteristics, paying special attention to histology and the information obtained using the sweep electron microscope.

Synthesis and Reactions of Strained Hydrocarbons Possessing Inverted Carbon Atoms. Tetracyclo[3.3.1.13.7.01.3]decanes

Tetracyclo[3.3.1.13.7.01..3]decane (i.e., 1,3-dehydroadamantane or DHA) and its 5,7-dimethyl derivative may be synthesized from the corresponding 1,3-dibromoadamantane compounds with sodium–potassium alloy in ether or heptane. These highly strained cyclopropyl compounds are very reactive towards free radical and electrophilic reagents. They homopolymerize 140–160° to thermally resistant, insoluble materials and spontaneously copolymerize with oxygen in solvents at room temperature. Reaction with bromine in ether at −70° yields an intermediate bromoadamantyloxonium tribromide which decomposes to 1-bromo-3-ethoxyadamantane on warming. Other rapid reactions of these strained 1,3-dehydroadamantanes are reported.