SUMMARY An investigation was made of 3 serological tests (virus neutralization, complement fixation and indirect immunofluorescence), which are applicable to epidemiological studies of infections by Equid herpesvirus 1 (EHV‐1). Sera from gnotobiotic foals inoculated intranasally with various strains of EHV‐1 were unable in some cases to neutralize heterologous strains and these results were not consistent with the existence of clearly‐defined subtypes of EHV‐1, as previously proposed. The cross‐reactions in complement‐fixation tests paralleled those with neutralization but immunofluorescence tests were found to be both more sensitive and more broadly reactive than the other two. Complement‐fixing antibodies declined more rapidly following experimental infection than did those measured by neutralization or immunofluorescence. The results are discussed in relation to the diagnosis of EHV‐1 infection and the significance they may have for the epidemiology of this disease. RÉSUMÉ En utilisant 3 tests sérologiques (Fixation du complément, Neutralisation du virus, Immuno‐fluorescence indirecte), on a procédéà des recherches épidémiologiques des infections équines par les Herpesvirus 1 (EHV‐1). Des sérums provenant de foals gnotobiotiques inoculés par voie transnasale avec diverses souches de EHV‐1 n'ont pu, dans certains cas, neutraliser des souches hétérologues; ces résultats ne concordaient pas avec l'hypothèse antérieurement formulée qui supposait l'existence de sous‐types EHV‐1 bien définis. Les réactions croisées obtenues par la Fixation du Complément donnèrent des résultats similaires à ceux obtenus par neutralisation. Au contraire, les épreuves par immunofluorescence furent à la fois plus sensibles et plus intenses. Les anticorps fixant le complément à la suite d'une infection expérimentale diminuèrent plus rapidement que les anticorps mesurés par neutralisation ou par immuno‐fluorescence. Ces résultats sont discutés quant à la valeur diagnostique et quant à la signification qu'ils peuvent avoir pour étudier l'épidémiologie de la maladie. ZUSAMMENFASSUNG 3 serologische Nachweismethoden (Virus‐Neutralisation; Komplementbindung und indirekte Immunofluoreszenz) wurden überprüft, die für epidemiologische Studien von EHV‐1‐Infektionen in Frage kommen. Serumproben von gnotobiotischen Fohlen, die intranasal mit verschiedenen EHV‐1 Stämmen inokuliert worden waren, zeigten sich in gewissen Fällen nicht fähig heterologe Stämme zu neutralisieren. Diese Resultate stimmen nicht überein mit der Existenz klar definierter Subtypen von EHV‐1, die früher vorgeschlagen wurden. Die Kreuzreaktionen im Komplementbindungstester‐gaben dieselben Resultate wie die Virusneutralisation, aber die Immunofluoreszenz erwies sich als empfindlicher und reagierte breiter als die beiden anderen Tests. Komplementbindende Antikörper fielen nach experimenteller Infektion schneller ab als die mit Neutralisation und Immunofluoreszenz nachgewiesenen. Diese Befunde werden besprochen unter Berücksichtigung ihrer Bedeutung für die Diagnose von EHV‐1 Infekt...

After repeated feeding of menthol to mice, Fishman (1940) obtained results which, on statistical examination, showed an increase in fi-glucuronidase activity in liver, spleen and kidney, as compared with organs from untreated ils. Similar results were obtained in dogs fed with borneol. Glucuronidase in uterus and other sex organs was unaffected by menthol, and borneol. In Fishman's own interpretation of these important experiments, ,B-glucuronidase is assumed to be responsible for glucuronide synthesis in the body. A synthetic role for the enzyme has, however, still to be demonstrated, its physical properties and distribution in the body having been studied solely by means of its hydrolytic action on-conjugated glucuronides. Since menthol and borneol have been proved tb be ex

The component of crude mushroom extracts which is responsible for the appearance of a purple colour when such extracts oxidize catechol has been identified by isolation of L-proline. 2. Thepigment-formingreactionhasbeenstudied in respect of coleur intensity developed, oxygen absorbed and hydrogen ion liberated, in systems containing purified tyrosinase, catechol or homocatechol, and one of the following: proline, hydroxyproline, hydroxyproline ethyl ester, pyrrolidine, glycine, dimethylamine and methylamine. A few experiments were also carried out with alanine, glutamic acid and arginine. The same intense purple colour was obtained in each case in which the nitrogenous substance present had a secondary amino group; the compounds with primary amino nitrogen gave a much less intense orange-red colour. 3. From homocatechol and hydroxyproline ethyl ester, by oxidation with silver oxide in ethanol, 4-(4'-hydroxy-2'-carbethoxy-1'-pyrrolidyl)-5-methylo-benzoquinone has been prepared in a pure state. It appears to be identical with the pigment formed from the same precursors in the enzymic reaction mixture, and it is concluded that all the pigments have an analogous structure, and that the pigmentforming reaction is essentially a condensation between 1 mol. of o-quinone and 1 mol. of nitrogenous base to give a leuco pigment which is spontaneously oxidized to the coloured form by oxygen. 4. In the case of glycine, when this is present in excess, the formation of pigment is followed by oxidation of the excess amino-acid, with liberation of ammonia. Further oxidation of this type does not take place in the case of the imino acid pigments.