Neuromuscular correlates of rhythmical cheliped flexion behavior in hermit crabs

Journal of Comparative Physiology A -     

The parasite load of some African game animals

The total parasite load, helminths and arthropods, was measured in wild antelopes (Antilopinae and Alcelaphinae) in Kenya. Two parasite faunas were present, one consisting of endemic species and the other of species introduced into Africa with human livestock, presumably within the last 2000 years. There was little evidence of natural immunity to helminthic infection and gazelle restricted by ranching died of acute helminth infection. The helminth fauna of antelopes was dissimilar from that of zebra and giraffe which graze in the same savannah area, although species of tick were shared. New host records from Kenya are given for Bigalkenema curvispiculum Gibbons, Paracooperia raphicerci Ortlepp, Trichostrongylus axei Cobbold and T. colubriformis Giles from Gazella thomsonii Gilnther, B. curvispiculum from G. granti Brooke, Cooperia fulleborni Hung from Connochaetes taurinus Burchell and Moniezia expansa Rudolphi from Giraffa camelopardalis tippel-skirchi L. The implication of parasitic infection to conservation programmes and the possible future erosion of the conservation areas in East Africa is discussed briefly.     

Effect of pH on the Immunogenicity of Mycoplasma pneumoniae

Mycoplasma pneumoniae harvested from media which had become acid lost the ability both to induce formation of tetrazolium reduction inhibition antibody and to act as antigens in immunodiffusion against human convalescent-phase sera. Incorporation of N-tris(hydroxymethyl)-2-aminoethane sulfonic acid and N-2-hydroxyethylpiperazine-N'-2-ethane sulfonic acid buffers into a new medium containing PPLO Serum Fraction instead of horse serum delayed the pH decline. Tris(hydroxymethyl)aminomethane, triethanolamine, and 3,6-endomethylene-1,2,3,6-tetrahydrophthalic acid buffers inhibited growth. Mycoplasmas obtained from buffered cultures retained antigenicity as measured by immunodiffusion and could stimulate tetrazolium reduction inhibition antibody formation in animals.     

MEASUREMENT OF INFLUENZA VIRUS-ANTIBODY REACTION BY QUANTITATIVE ELECTRON MICROSCOPY

Measurement of the weight of individual virus particles from untreated and antibody-treated populations was made by quantitative electron microscopy. The weight of antibody bound depended on the concentration of antibody in solution. One population of viruses exposed to an antibody concentration which resulted in 95% inhibition of hemagglutination showed a mass increase of 55%, corresponding to an absolute increase of 9.0 x 10^-17 g in the median value. Another population, whose hemagglutination inhibition assay was 64%, showed a 39% increase in mass corresponding to an absolute median increase of 7.3 x 10^-17 g. The larger viruses in each population bound a greater absolute amount of antibody than did the smaller ones, but the latter bound relatively more antibody in proportion to their mass. No cross-reactivity was found between the antibody to influenza A/PR8 and the influenza strain B/LEE. Influenza A/PR8 controls exposed to nonspecific gamma-globulin displayed a significant weight loss, at least in part owing to loss from the core, as judged from the electron micrographs.