Continuous cell lines derived from many of the vectors of tick-borne arboviruses of medical and veterinary importance are now available. Their role as tools in arbovirus research to date is reviewed and their potential application in studies of tick cell responses to virus infection is explored, by comparison with recent progress in understanding mosquito immunity to arbovirus infection. A prel...

Pathogenic spirochetes in the genus Borrelia are transmitted primarily by two families of ticks. The Lyme disease spirochete, Borrelia burgdorferi, is transmitted by the slow-feeding ixodid tick Ixodes scapularis, whereas the relapsing fever spirochete, B. hermsii, is transmitted by Ornithodoros hermsi, a fast-feeding argasid tick. Lyme disease spirochetes are generally restricted to the midgut...

Borrelia hermsii is the most common cause of tickborne relapsing fever in North America. DNA sequences of the 16S-23S rDNA noncoding intergenic spacer (IGS) region were determined for 37 isolates of this spirochete. These sequences distinguished the 2 genomic groups of B. hermsii identified previously with other loci. Multiple IGS genotypes were identified among isolates from an island, which s...

The primary cause of tick-borne relapsing fever in western North America is Borrelia hermsii, a rodent-associated spirochete transmitted by the fast-feeding soft tick Ornithodoros hermsi. We describe a patient who had an illness consistent with relapsing fever after exposure in the mountains near Los Angeles, California, USA. The patient's convalescent-phase serum was seropositive for B. hermsi...

The epidemiology of vector-borne zoonoses depends on the movement of both hosts and vectors, which can differ greatly in intensity across spatial scales. Because of their life history traits and small size, vector dispersal may be frequent, but limited in distance. However, little information is available on vector movement patterns at local spatial scales, and particularly for ticks, transmitt...

Outbred Wistar rats immunized with native type II collagen developed ear lesions resembling those of human relapsing chondritis. As in human disease, these lesions were characterized by intense chondritis, positive immunofluorescence reactions to IgG and C3, and circulating IgG reactive with native type II collagen. Furthermore, electron-dense deposits were seen near the surface of chondrocytes...

Relapsing polychondritis (RP) is an inflammatory disease of the cartilaginous tissue primarily affecting the cartilaginous structures of the ear, nose, joints, and the respiratory system. Cardiovascular complications of RP are associated with high morbidity and mortality and occur most commonly as valvular disease. Pericarditis is a less common complication, occurring in 4% of patients with RP ...

Relapsing polychondritis (RPC) is a unique and rarely observed autoimmune condition regarded as recurrent extensive chondritis of the auricular, nasal, and tracheal cartilages. Moreover, heart, main arteries, skin, and eyes may be involved. Several forms of clinical manifestations may be seen, and the pathogenesis still remains anonymous. A concomitant disease, particularly myelodysplasia or ot...

Experimental evidence suggests that C inhibition and more particularly combined inhibition of C and the TLR coreceptor CD14 may be of therapeutic benefit in sepsis and other inflammatory conditions. A barrier to the testing and further development of many inhibitors is that their activity is species specific. Pig is a relevant species for experimental models of human disease, and this study und...