ABSTRACT
Keloids and hypertrophic scars represent exuberant forms of scar formation that frequently are pruritic, painful, and occasionally form strictures. As well, they may result in significant cosmetic disfigurement. Recent years have seen an increased understanding in the molecular and biological mechanisms of keloidal scar formation, allowing for the development of more specific therapeutic options for these lesions. Despite these developments, keloids and hypertrophic scars remain difficult to manage. Clinical, histopathological, and biochemical features of keloids and hypertrophic scars, as well as treatment guidelines, are discussed.
Subject(s)
Cicatrix, Hypertrophic/physiopathology , Cicatrix, Hypertrophic/therapy , Keloid/physiopathology , Keloid/therapy , Wound Healing/physiology , Adrenal Cortex Hormones/administration & dosage , Combined Modality Therapy , Cryosurgery/methods , Drug Therapy , Female , Humans , Injections, Intradermal , Interferons/administration & dosage , Laser Therapy/methods , Male , Radiotherapy , Plastic Surgery Procedures/methods , RecurrenceSubject(s)
Coloring Agents/adverse effects , Lip Diseases/chemically induced , Tattooing , Adult , Female , HumansABSTRACT
In areas where the agent of Lyme disease is intensely enzootic, the mouse reservoirs may be universally infected. Because a large proportion of the vector tick population appears to feed upon these hosts, the prevalence of infection in the vectors should approach 100%. However, infection in host-seeking nymphal ticks in nature rarely exceeds 40%. To help reconcile this apparent paradox, we examined whether estimates of prevalence might differ if we did not assume that infected ticks are randomly or uniformly distributed within a site. Nymphal Ixodes dammini were collected by dragging a series of 10-meter replicates within an intensely enzootic site. Estimates of the prevalence of spirochetal infection, based upon the monthly means of individual 10-meter collections, were then compared with estimates derived by pooling all samples. Host-seeking ticks tended to cluster. The Lyme disease spirochete was present in 15.6% of 469 pooled ticks. When the prevalence estimate was based solely on ticks in clusters that contained one or more infected ticks, however, at least 50% of the ticks were infected. We conclude that nymphal deer ticks infected by Lyme disease spirochetes tend to aggregate spatially in nature, and that prevalence estimates based upon a mean value for pools may be misleading.
Subject(s)
Arachnid Vectors/microbiology , Borrelia burgdorferi Group/isolation & purification , Ticks/microbiology , Animals , Arachnid Vectors/isolation & purification , Cluster Analysis , Computer Simulation , Deer , Models, Biological , Ticks/isolation & purificationABSTRACT
Brugia malayi microfilariae of specified ages were obtained from gerbils implanted with fertile adult worms. Such microfilariae were tested for their capacity to infect mosquitoes. A strong age dependence was found for the microfilariae's capacity to: penetrate the mosquito midgut, exsheath in response to 20 mM calcium, and develop to third stage larvae in the mosquito. In addition, differences were found between 2-day-old microfilariae and controls (from larva-infected gerbils) in their reactivities with a series of monoclonal antibodies. Thus, defined immunochemical changes occur in microfilariae as they assume functional maturity.
