SUMMARY
As reported in the literature, there is a potentially wide spectrum of antiparasitic and antibacterial activity in the chemical group of nitroheterocyclic compounds. The schistosomicide Ambilhar (niridazole) is an example of a single compound exhibiting anthelminthic, antiprotozoal, and antibacterial properties. A description is given of some of these properties, as revealed in laboratory experiments.
The antiamoebic activity of Ambilhar is superior to that of emetine and chloroquine. This statement applies not only to its curative effect against amoebic liver infection, but also to its amoebicidal activity in the rat intestine. With regard to trichomonicidal activity, reference is made to metronidazole as the chemotherapy of choice in trichomoniasis. When mice are used as test models, however, Ambilhar proves active at the same dosage level as metronidazole. In mice, Ambilhar also displays a distinctive spectrum of antibacterial activity; its effect on various types of Enterobacteriaceae, including Salmonella and Shigella species, is of particular interest.
In various experimental infections inthe mouse, the single doses of chlortetracycline were determined which, when given simultaneously with the infection, prevent death of the animals. Serum concentrations of the antibiotic were measured in mice treated with 80–100% effective doses. During the initial period of infection, which is characterized by insufficient defence (low resistance period), these concentrations are invariably above or approximately equal to the minimum bacteriostatic concentration established in vitro. Hence, it is concluded that in animal experiments the dosage is dependent not only on the in vitro sensitivity of the infectious agent but also on the length of the LRP, during which the micro-organisms have to be controlled by a bacteriostatic agent.
Unter den Stoffwechselprodukten eines Actinomyceten der Spezies Strefitomyces griseoflavus (KRAINSKY) WAKSMAN et HENRICI, den wir aus einer bei Calcutta gesammelten Bodenprobe isoliert hatten, liessen sich antibiotisch wirksame Stoffe nachweisen. Diese konnten, nach Ziichtung des Mikroorganismus in Gartank-Kultur, aus den Kulturfiltraten in Form lipophiler Basen extrahiert und durch Chromatographie an Aluminiumoxid angereichert werden. Die Hauptkomponente der aktiven Basen erhielt man dabei in kristallinem Zustand. Die Verbindung ist unseres Wissens noch nicht beschrieben worden. Wir bezeichnen sie als Acumycin z ) . Allgemeine fihysikalische und chemische Eigenschaften: Acumycin kristallisiert in iarblosen Prismen, die unter Zersetzung bei 235" schmelzen. Die bis jetzt vorliegenden analytischen Befunde konnen in einer vorlaufigen3) Bruttoformel C,,H,,O,,N zusammengefasst werden. Auf diese Formel berechnet enthdt das Acumycin mindestens 7 nach KUHN-ROTH bestimmbare C-Methylgruppen. Weiterhin lassen sich zwei aktive H-Atome (ZEREWITINOFF) nachweisen. Bei der Titration in 80-proz. Methylcellosolve wurde ein pKgCs-Wert 4, von 6,46 und ein Aquivalentgewicht von 741 (ber. 724) festgestellt. Acumycin ist linksdrehend: [a], = -92" (Chloroform). Es zeigt im UV.-Absorptionsspektrum ein hohes Maximum bei 241 mp (log E = 4,19). Das in KBr aufgenommene 1R.-Absorptionsspektrum (Fig.
The number and distribution of Peyers patches in the small intestine of 461 Chinchilla rabbits and 19 Russian bred rabbits were determined during surgery and a t a subsequent necropsy. The Peyers patches were located within the jejunum and ileum where they were evenly distributed along the antimesenteric portion of the intestine. No correlation was found between length of the intestine and numbers of Peyers patches.
The minimum inhibitory concentration of bactericidal as opposed to bacteriostatic agents does not necessarily have to be maintained in the blood for the full duration of the low resistance period (LRP). Even brief exposure to concentrations which are bactericidal or high enough to induce bacteriopause can effectively suppress the infection. The longer the LRP, the more sustained must be the antibacterial effect. The relations between these factors are examined with reference to the effect of single doses of rifampicin and cephaloridine in a series of experimental infections in the mouse.
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