Biochemical genetic relationship of Thailand and Hawaii isolates of Parastrongylus cantonensis (Nematoda: Angiostrongylidae)

The genetic relationship of the Thailand and Hawaii isolates (strains) of the rat lungworm Parastrongylus (=Angiostrongylus) cantonensis was investigated by gene–enzyme systems using vertical polyacrylamide slab gel electrophoresis. Six gene–enzyme systems were successfully determined, with each being represented by two presumptive loci. Glucose phosphate dehydrogenase, glucose phosphate isomerase, lactate dehydrogenase, malate dehydrogenase and malic enzyme were monomorphic at both loci, and the respective bands exhibited similar mobility in both isolates implying absence of genetic variation. Of the two phosphoglucomutase loci, the faster-moving locus (PGM-1) was polymorphic in the Hawaii isolate, represented by two alleles, the faster-moving, less common Pgm-1A (allele frequency = 0.36 ± 0.03) and the slower-moving, more common Pgm-1B (allele frequency = 0.64), with heterozygosity of 0.43. PGM-1 was monomorphic in the Thailand isolate, represented by the faster-moving Pgm-1A allele. The slower-moving PGM-2 locus was invariant, with a single band of enzyme activity, in the female worms of both the Thailand and Hawaii isolates. There was no detectable enzyme activity at this PGM-2 locus in the male worms of both isolates. The non-expression or ‘null’ PGM-2 phenotype in the male worms was presumed to be sex-limited. Based on the six gene–enzyme systems with a total of 12 presumptive loci, it can be concluded that the Thailand and Hawaii isolates of P. cantonensis are genetically very similar, with a genetic distance of D = 0.03. The very low proportion of polymorphic loci (P = 0.08) in the Hawaii isolate and its absence in the Thailand isolate may be attributed to founder effect (a special type of genetic drift)

Molecular diagnosis of eosinophilic meningitis due to Angiostrongylus cantonensis (Nematoda: Metastrongyloidea) by polymerase chain reaction-DNA sequencing of cerebrospinal fluids of patients

Cerebrospinal fluid (CSF) samples from clinically diagnosed patients with detectable Angiostrongylus canto-nensis-specific antibodies (n = 10), patients with clinically suspected cases that tested negative for A. cantonensis-an-tibodies (n = 5) and patients with cerebral gnathostomiasis (n = 2) and neurocysticercosis (n = 2) were examined by a single-step polymerase chain reaction (PCR) method using the AC primers for the 66-kDa native protein gene. The PCR method detected A. cantonensis DNA in CSF samples from four of 10 serologically confirmed angiostrongyliasis cases. The PCR results were negative for the remaining CSF samples. The nucleotide sequences of three positive CSF-PCR samples shared 98.8-99.2% similarity with the reference sequence of A. cantonensis. These results indicate the potential application of this PCR assay with clinical CSF samples for additional support in the confirmation of eosinophilic meningitis due to A. cantonensis

Sex Differences in Autoimmune Disease from a Pathological Perspective

Autoimmune diseases affect ∼8% of the population, 78% of whom are women. The reason for the high prevalence in women is unclear. Women are known to respond to infection, vaccination, and trauma with increased antibody production and a more T helper (Th)2-predominant immune response, whereas a Th1 response and inflammation are usually more severe in men. This review discusses the distribution of autoimmune diseases based on sex and age, showing that autoimmune diseases progress from an acute pathology associated with an inflammatory immune response to a chronic pathology associated with fibrosis in both sexes. Autoimmune diseases that are more prevalent in males usually manifest clinically before age 50 and are characterized by acute inflammation, the appearance of autoantibodies, and a proinflammatory Th1 immune response. In contrast, female-predominant autoimmune diseases that manifest during the acute phase, such as Graves’ disease and systemic lupus erythematosus, are diseases with a known antibody-mediated pathology. Autoimmune diseases with an increased incidence in females that appear clinically past age 50 are associated with a chronic, fibrotic Th2-mediated pathology. Th17 responses increase neutrophil inflammation and chronic fibrosis. This distinction between acute and chronic pathology has primarily been overlooked, but greatly impacts our understanding of sex differences in autoimmune disease