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Societies and Academies

Nature volume 85, pages 427430 (26 January 1911) | Download Citation

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LONDON. Royal Society, January 19.—Sir Archibald Geikie, K.C.B., president, in the chair.—G. S. Walpole: The action of B. lactis aerogenes on glucose and mannitol. Part ii. The “crude glycol” obtained by the action of B. lactis aerogenes on glucose contains two optically inactive 2:3-butane diols, the diphenylurethanes of which melt at 199.5° and 157° respectively. The former constitutes well over 90 per cent, of the material. If fructose be substituted for glucose in one of the flasks, the yield of “crude butylene glycol” and acetylmethyl carbinol is of the same order as when glucose is employed. Acetylmethyl carbinol is formed abundantly when the bacillus is cultivated in a solution of butylene glycol in 1 per cent, peptone in a current of oxygen.—Dr. W. E. Dixon: The pharmacological action of Gonioma Kamassi (South African boxwood). South African boxwood, Gonioma Kamassi, has been employed occasionally in Lancashire as a substitute for common boxwood in the manufacture of shuttles; it is stated that symptoms of poisoning have occurred in a small proportion of the men engaged in sawing this wood or finishing the chiselled shuttles. From the wood an alkaloid can be obtained to about 0.07 per cent. This has a very characteristic physiological action, which places it in the curare group of drugs. The members of this group may be regarded as possessing three actions in common:—(1) paralysis of certain nerve cells; (2) increase of spinal and medullary reflexes; (3) paralysis, of motor nerve endings. Boxwood exerts all these effects. It paralyses the nerve cells in the brain and medulla, as well as those on the course of the vagus and sympathetic nerves, and therefore after its exhibition to animals the stimulant action of nicotine cannot be obtained. In small doses the reflexes are increased, and if an injection be made into a vein going to the spinal cord of an animal, strychnine-like convulsions are produced. Boxwood causes death by paralysing the respiration; this is central in origin, but it occurs at a time when the phrenics and intercostals are depressed, though not paralysed. Boxwood has no direct action on the heart or on other form of muscle. Reasons are given for believing that the recorded cases of poisoning are not due to the specific action of the drug after absorption, but to the effect of the drug in facilitating certain local reflexes, principally of a respiratory nature, in the predisposed.—Dr. W. Yorke: Autoagglutination of red blood cells in trypanosomiasis. Autoagglutinin exists in small quantity in the blood of many normal animals. It is frequently present in much greater quantity in the blood of animals infected with trypanosomes. Reaction between auto-agglutinin and erythrocytes takes place only at low temperatures. The strongest reactions are obtained when a suspension of washed erythrocytes in normal saline solution is treated at 0° C. with plasma, which has been prepared by defibrinating blood at 37° C. Autoagglutinin can be removed from plasma by absorption with the erythrocytes of the same animal. The reaction between auto-agglutinin and red blood cells is reversible, the clumps disappearing on warming and reappearing on cooling. Iso- and hetero-agglutinin are also often present in much greater amount in the blood of infected animals than in that of normal animals of the same species. From the red blood cells of an infected animal, which have been agglutinated in the cold by the plasma of the same animal, an active substance can be extracted with normal saline solution at 37° C. This substance agglutinates, not only the red cells of the same animal and other members of the same species, but also those of many animals of different species. Observations of this kind indicate that auto-, iso-, and hetero-agglutinin are not different highly specific substances, but have closely related affinities. That a clumping together of the red blood cells is frequently observable in coverslip preparations of the fresh blood of animals and man infected with trypanosomiasis is due to the existence of an excess of autoagglutinin in the plasma, which reacts with the erythrocytes to a certain extent at the temperature (15°–20° C.) at which the preparations are usually made. It is to be nferred from the information at present available that a marked degree of autoagglutination of red blood cells is an extremely rare occurrence apart from an infection with trypanosomes. The phenomenon is therefore of some value as a diagnostic sign.—M. Nierenstein: The transformation of proteids into fats during the ripening of cheese (preliminary communication). Contrary to the accepted view, it was found that the so-called ripening of cheese is not accompanied by a transformation of proteids into fats, the increase of weight of the latter, as observed by other workers, being due to the presence of free cholesterol, aminovaleric acid, putrescine, and cadaverine in the etherial extract. This investigation disproves one of the frequently quoted evidences in favour of the theory that proteids serve as a source for the fat-formation in the animal body.—J. F. Gaskell: The action of X-rays on the developing chick. No difference was observed in the action of X-rays upon any one tissue rather than another. The action is confined to the lowering of the mitotic activity of the growing tissues. If this diminution is not too great, complete recovery occurs, and the chicks hatch out at the usual time. If the diminution is above a certain degree, recovery does not take place, and further development is arrested forthwith. The critical dose, which just prevents recovery, varies with the stage of development of the embryo, decreasing as the mitotic index decreases. The “mitotic index” as defined by Minot represents the number of mitoses per 1000 cells in the various tissues of embryos of various ages, and he has shown that throughout embryonic life a rapid diminution of mitotic activity is going on. He calls the figures obtained the mitotic index for that particular tissue.—Colonel Sir David Bruce and Captains A. E. Hamerton and H. R. Bateman. (Sleeping Sickness Commission of the Royal Society, Uganda, 1908–10.) Experiments to ascertain if antelope may act as a reservoir of the virus of sleeping sickness (Trypanosoma gambiense). It is known that the tsetse-flies (Glossina palpalis) around the northern shores of the Victoria Nyanza still retain their infectivity for sleeping sickness, in spite of the fact that the native population Was removed from the lake-shore some three years ago. A series of experiments was, therefore, carried out to ascertain if the antelope, which are fairly common along the uninhabited shores of the lake, were capable of acting as hosts of the parasite of sleeping sickness. Eleven antelope of the waterbuck, bushbuck, and reedbuck species were obtained from a district where tsetse-flies and sleeping sickness did not exist. Blood from these animals was first inoculated into monkeys to ascertain if they were already naturally infected with trypanosome disease. They proved to be healthy in this respect. Tsetse-flies (Glossina palpalis) that were known to be infected with the virus of sleeping sickness were then fed upon each of the eleven antelope. After about eight days the blood of these animals was again inoculated into susceptible animals, with the result that the latter became infected with Trypanosoma gambiense in every case. In eight out of the eleven buck under experiment Trypanosoma gambiense appeared in their blood for a few days only (some seven to twelve days) after they had been bitten by infected flies. Flies that were, hatched out in the laboratory, and had never fed before, were now fed upon the infected antelope, and subsequently upon monkeys. After an interval of about thirty days, required for the development of trypanosomes within the fly, monkeys were infected with, sleeping sickness from the antelope by the agency of Glossina palpalis in sixteen but of twenty-four experiments. On dissecting the flies which had been fed upon the infected antelope, it was found that 10.8 per cent. of them were infected with Trypanosoma gambiense. The highest percentage of infected flies in any one of the positive experiments was 21 per cent.; the lowest was 1.3 per cent. Nine of these antelope infected with Trypanosoma gambiense were under daily observation for more than four months. They remained in perfect health. Two of them (a waterbuck and a bushbuck) never showed frypanosonies in their blood, although examined every day. Both these antelope-infected flies fed upon them, one of them as long as fifty-five days after its infection. No wild antelope inhabiting the lake-shore has yet been found to be naturally infected with Trypanosoma gambiense.—Colonel Sir David Bruce and Captains A. E. Hamerton and H. R. Bateman. (Sleeping Sickness Commission of the Royal Society, Uganda, 1908–10.) Experiments o to ascertain if the domestic fowl of Uganda may act as a reservoir of the Virus of sleeping sickness (Trypanosoma gambiense). There is evidence that tsetse-flies (Glossina palpalis) feed on the blood of birds as well as that of marrimals inhabiting the shores of Victoria Nyanza. Domestic fowls, as representing birds, Were experimented with in the search for possible hosts or reservoir? of the virus of sleeping sickness. A series of twenty-one experiments was carried out to o ascertain:—(1) if these birds can, like antelope, be infected with Trypanosoma gambiense by the bites of known infected flies; (2) if birds so infected can transmit the parasite to newly hatched Glossina palpalis which had not fed before they were allowed to bite the fowls; (3) if these flies can convey sleeping sickness to normal monkeys. About 2000 flies, many of which had been proved. to be infected with viru lent Trypanosoma gambiense, were fed, upon twenty-one domestic fowls. The results were negative in every case, as ascertained by frequent microscopical examination of peripheral and centrifuged heart's blood, and inoculations of the fowls' blood into susceptible animals. Four hundred newly hatched flies were fed upon three of the fowls which had been bitten by infected flies. The former were sub sequently fed upon monkeys, with the result that they failed to convey sleeping sickness from fowls to monkeys. Two hundred, and eighty-three of these flies were dis sected, and no flagellates could be found in them. Conclusion.—The Uganda fowl cannot act as a reservoir of the virus of sleeping sickness.

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https://doi.org/10.1038/085427a0

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