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Biomedical subjects

P B McGreevy

Publications and source records attributed to P B McGreevy.

7 recordsLinked to original sources

Successful vaccination of cats against Brugia pahangi with larvae attenuated by irradiation with 10 krad cobalt 60.

Cats were vaccinated by the inoculation on 10 occasions of approximately 300 larvae of Brugia pahangi which had been irradiated with 10 krad cobalt 60. They were challenged on 3 occasions with normal larvae of either B. pahangior B. patei. The vaccinated cats were resistant to challenge as demonstrated by either longer pre-patent periods or failure to become microfilaraemic and by having fewer third, fourth or adult worms than normal controls. Although the vaccination procedure was unpractically heavy these results lend encouragement to the possibility of developing vaccines against filarial infections.

Animals

The lethal effects of the cibarial and pharyngeal armatures of mosquitoes on microfilariae.

Microfilariae of Wuchereria bancrofti and Brugia pahangi were killed by the chewing action of the cibarial and pharyngeal armatures and other papillae and spines in the fore-gut of mosquitoes. The proportion of ingested microfilariae that were killed was largely dependent on the presence and shape of the cibarial armature. Anopheles farauti No. 1 and Anopheles gambiae species A and B have well developed cibarial armatures and killed 36 to 96% of the ingested microfilariae. Culex pipiens fatigans has a poorly developed cibarial armature and killed only 6% of the microfilariae. Aedes aegypti and Aedes togoi lack cibarial armatures but have the remaining fore-gut structures. They killed only 2 to 22% of the microfilariae. The significance of these observations in relation to the control of filariasis with diethylcarbamazine is discussed.

Animals

Studies with Brugia pahangi 17. The anthelmintic effects of diethylcarbamazine.

Diethylcarbamazine (DEC) was active in vitro against infective larvae and microfilariae of Brugia pahangi but only at high concentrations. When fed to mosquitoes which were infected with B. pahangi it had little or no activity. In jirds it was inactive against B. pahangi microfilariae and adults when administered at 300 mg/kg for 5 days either by the intraperitoneal or oral route. In cats given 25 or 50 mg DEC/kg intraperitoneally on 3 or 5 occasions it was not microfilaricidal, but most of the adult worms died within 30 days of the end of treatment. Although most microfilariae disappeared from the blood of cats immediately (i.e., within an hour) after treatment, they reappeared within a few hours in the same numbers. Microfilarial levels were reduced after treatment but there was no precipitate decline as occurs in human B. malayi patients.

Animals

Studies on Brugia pahangi. 13. The anthelmintic effect of compounds F151 (Friedheim), HOE 33258 (Hoechst) and their reaction product.

F151 was a potent filaricide against adult Brugia pahangi in cats and jirds. HOE 33258 did not kill adult worms in cats but had a marginal effect on adult worms in the peritoneal cavity of jirds. It was not immediately microfilaricidal in cats but the microfilarial counts of treated cats fell within a few weeks of treatment. The reaction product, or mixture, of these two compounds (V5851 = E) was strongly macrofilaricidal in cats and jirds.

Animals

Studies with Brugia pahangi 10. An attempt to demonstrate the sharing of antigenic determinants between the worm and its hosts.

Infective stage Brugia pahangi that were reared in Aedes aegypti survived equally well in cats that had previously been immunized against mosquito tissue and in a normal cat. The survival of third, fourth, juvenile, adult and microfilarial stages of B. pahangi that were recovered from cats was similar in jirds that had been immunized against cat antigens and in normal jirds. Host antigenic determinants were not detected on the surface of larvae in substantial amounts using fluorescent antibody techniques. It is unlikely that B. pahangi evades the immune response of its vertebrate hosts by masquerading as "self" behind host antigens.

Aedes