Notes on toxinology

Conclusions Some of the papers to follow in the present series of communications on toxinology will show that in the field of chemistry, physiology, pharmacology and immunology, as well as molecular biology, animal venoms provide us with some particularly useful models. Obviously, this is one of the main reasons for the growing interest shown by numerous scientists in animal toxins.With reference to medicine, more research is needed in the field just mentioned with the aim of improving medical care. In addition, however, it is postulated that research on the behaviour of venomous animals towards man, and research into the quantities of venom actually applied to man, be intensified. Also, on the basis of results in this context, people most exposed could be provided with more and better information about prevention.Work of this sort requests the collaboration of biologists, who observe toxic animals in their natural habitat and who investigate in particular when, and under what prerogatives, the animals make use of toxins in their natural surroundings. Thus we end up with what has been said in the introduction to these notes: toxic animals are to be studied as entities and toxicity has to be looked at from all aspects essential for life, possibly including parasite and population control.Should the very last point prove valid, fascinating links could be established between toxinology and ecology and in turn migt become important for nature conservation. Thus, toxinology is but a budding field, the limits of which, can yet only be assumed.     

Acetylcholine-induced atrial tachyarrhythmia: A modification to quantitate potency and duration

Résumé La méthode d'induction de fibrillation auriculaire par l'acétylcholine est couramment utilisée pour tester l'action de substances anti-arythmiques. Nous avons modifié cette méthode de telle sorte que la fibrillation peut être induite à plusieurs reprises, à 15 minutes d'intervalle, chez le chien anesthésié. Ceci permet la détermination de l'efficacité et de la durée d'action dans des conditions bien contrôlées.     

Effect of long-term fenfluramine treatment on drug-metabolism in rat

Zusammenfassung Nachweis, dass Fenfluramin in Dosen von 25 und 50 mg/kg p.o. Arzneimittel abbauende Enzyme stimuliert und die Cytochromen b₅ und P-450 in der Rattenleber vermehrt. Der induzierende Effekt ist bereits nach 3 Wochen maximal.     

Cholestanol and chenodeoxycholic acid: Metabolites of injected cholesterol-4-14C in pigeon bile

Zusammenfassung Es gelang, in Tauben die Umwandlung von injiziertem Cholesterol-C¹⁴ in Gallen-Cholestanol nachzuweisen, wobei Chenodeoxycholinsäure als Hauptmetabolit des Cholesterols-C¹⁴ in der Galle ermittelt wurde.     

Phenobarbital specific antisera and radioimmunoassay

Résumé On a développé un anticorps d'une grande affinité et spécifité envers le phénobarbital en inoculant des lapins avec une solution de barbiturateprotéide, synthétisée d'acide barbiturique de 5-phényl-5-(4-aminobutyl) et d'albumine de sérum bovin par du carbodiimide. Usant de cet anticorps comme radioimmunoeassai, on peut mesurer jusqu'à 1 picomole de phénobarbital par ml de fluides biologique sans que d'autres barbiturates y opposent une réaction significative.

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We express our appreciation to the Lilly Research Laboratories for the donation of amobarbital and secobarbital.     

Influence of classical immunosuppressants on spleen colony formation in mice

Zusammenfassung Nachweis eines Hemmeffektes immunosupressiver Mittel (Cortison, Cyclophosphamide und Immuran) bei Mäusen nach UV-Bestrahlung auf die hämopoetische Regeneration (Milzkolonien und Knochenmarkzellen).     

The effect of unilateral and bilateral lesions in the locus coeruleus on the levels of 3-methoxy-4-hydroxyphenylglycol (MHPG) in neocortex

Résumé Des lésions électrolytiques, soit unilatérales soit bilatérales, ont été pratiquées dans des cerveaux de rats, dans la région du locus coeruleus. Trois semaines après, la teneur en 3-méthoxy-4-hydroxyphénylglycol (MHPG) des deux cortices cérébraux a été analysée par chromatographie à gaz. Les lésions unilatérales ont réduit la teneur en MHPG du cortex ipsilatéral, et après les lésions bilatérales la réduction ent lieu dans les deux cortices.     

The production of plasminogen activator during perfusion of isolated rabbit kidneys

Résumé On a constaté que la production et la sécrétion de l'activateur du plasminogéne a lieu pendant la perfusion des reins du lapin à l'aide d'une suspension d'érythrocytes oxygenés.     

Site and stand characteristics related to white pine blister rust in high-elevation forests of southern Idaho and western Wyoming

Successful infection of white pine species by white pine blister rust (WPBR) is contingent upon environmental conditions that are favorable to the spread and development of Cronartium ribicola . Site and stand factors related to this process have been studied elsewhere within the distribution of the disease, but few studies have concentrated on the high-elevation white pine forests of southern Idaho and western Wyoming. We found that mean summer precipitation, average tree diameter, and elevation were the most important variables in 3 logistic regression models of WPBR presence and intensity. The models were tested on a randomly chosen portion of our data set. The model with 9 variables correctly predicted categories of low-, moderate-, and high-disease incidence in 79% of cases. The 2 models with fewer variables had lower predictive efficiencies but were more parsimonious and generally easy to measure. The ability to use easily measured or remotely sensed site and stand characteristics to predict WPBR spread or intensification could be an important asset to land managers who need to decide where to focus disease mitigation efforts and predict disease effects on water quality, wildlife habitat, recreation potential, and other land-management activities.