The effects of calcium channel blockers, nifedipine and verapamil (i.v. and aerosol), were investigated in beagle dogs natively allergic to Ascaris suum antigen. Control exposures to an aerosol of Ascaris antigen provoked significant bronchopulmonary changes, i.e., increases in pulmonary resistance (RL) and decreases in dynamic lung compliance (CDYN). Pretreatment with either nifedipine or vera...

Ascaris suum and Ascaris lumbricoides exhibit an over-dispersed frequency distribution in their host populations in both the adult and larval stages. The impact of host factors on this observed distribution is still poorly understood and difficult to investigate in the natural host populations. The use of a mouse model has been supported by the observations that the larval migratory pattern, in...

Experiments were conducted to investigate possible alternative routes of extraintestinal migration of Ascaris suum larvae in the pig. Pigs were infected with A. suum via injection of newly hatched larvae into cecal veins (i.v.), into cecal lymph nodes (LN), or intraperitoneally (i.p.), and control animals were inoculated orally with infective eggs (p.o.). Two pigs per inoculation route were nec...

Two synaptonemal complexes (SCs) were present in the pachytene nuclei of Ascaris megalocephala. The SC was tripartite and comprised of two lateral elements (25 nm) with a striated central element (25 nm) and a central region of 65 nm. Spherical recombination nodules were observed to be associated only with the central element, although they are non-existent in the related A. lumbricoides var. s...

This study was designed to compare the sensitivity and specificity of enzyme linked immunosorbent assay (ELISA) for the serodiagnosis of ocular toxocariasis using Toxocara canis embryonated egg antigen (TEE) and toxocara excretory-secretory or exoantigen (TEX) produced in vitro. TEE and TEX ELISA were comparably sensitive, but TEX ELISA was better able to discriminate between serum samples from...

1. Acetylcholine (ACh) elicited depolarization and an increase in input conductance of the somatic muscle cells of the parasitic nematode Ascaris suum. 2. The relative potency of nicotinic and muscarinic agents was studied in this preparation. The order of potency of these compounds was metahydroxy-phenylpropyltrimethylammonium (HPPT) greater than 1.1 dimethyl-4-phenylpiperazinium (DMPP) greate...

We have determined the prototype sequence of the DNA which is eliminated in the course of chromatin diminution in Ascaris suum. This DNA which is virtually absent from somatic cells but retained in the germ line consists predominantly of highly repetitive sequences which are variants of an AT rich 123 base pair repeat unit. Both major and minor variants have been sequenced. The overall structur...