Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0033774 (pruritus)
 14,546 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Skin lesions associated with alpha 1-antitrypsin deficiency are becoming better defined and understood. Deficiency in this major antiproteinase, which neutralizes multiple proteolytic enzymes ranging from collagenases and elastases to trypsin and chymotrypsin, thus results in significant tissue autodigestion. This anti-proteinase is secreted by activated lymphocytes and macrophages, suggesting the existence of homeostasis which titrates the release of proteolytic enzymes by these cells, and the adequate neutralization of these proteases in order to prevent excessive tissue autodigestion each time these inflammatory cells are activated. We report a patient with alpha 1-antitrypsin deficiency who, following insect bites and cellulitis developed widespread itching and scratching, leading to widespread lesions of prurigo nodularis. The colonization of his multiple skin lesions with Staphylococcus aureus and the release of potent T cell mitogens, such as Protein A and enterotoxin A from the bacterial cell membrane may have resulted in the release of additional proteolytic enzymes by the activated lymphocytes and macrophages, without the concomitant secretion of alpha 1-antitrypsin with subsequent aggravation of his pruritus. These concepts are supported by electron microscopic evidence of excessive tissue autodigestion, and by immunocytochemical data identifying the presence of T helper and T cytotoxic/suppressor lymphocytes as well as macrophages within the upper dermis.
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PMID:Alpha-1 antitrypsin deficiency in a patient with widespread prurigo nodularis. 182 11

Several species of Culicoides biting midges are important pests and vectors of pathogens affecting humans and other animals. Bluetongue is the most economically important arthropod-borne animal disease in the United States. Culicoides variipennis is the primary North American vector of the bluetongue viruses. A reddish halo surrounding a petechial hemorrhage was noticed at the site of C. variipennis blood feeding in previously unexposed sheep and rabbits. Salivary gland extracts of nonblood-fed C. variipennis injected intradermally into sheep and rabbits induced cutaneous vasodilation in the form of erythema. A local, dose-dependent erythema, without edema or pruritus, was noted 30 min after injection. Erythema was inapparent with salivary gland extracts obtained after blood feeding. This observation suggested that the vasodilatory activity was inoculated into the host skin at the feeding site. The vasodilatory activity was insoluble in ethanol and destroyed by trypsin or chymotrypsin, which indicated that vasodilation was due to a protein. The association of cutaneous vasodilation with a salivary protein was corroborated by reversed-phase, high-performance liquid chromatography (HPLC). Fractionation of salivary gland extracts by molecular sieving HPLC resulted in maximal vasodilatory activity that coeluted with a protein having a relative molecular weight (MWr) of 22.45 kD. The C. variipennis vasodilator appears to be biologically active at the nanogram level. This vasodilator likely assists C. variipennis during feeding by increasing blood flow from host superficial blood vessels surrounding the bite site. The identification of a salivary vasodilator in C. variipennis may have implications for the transmission of Culicoides-borne pathogens and in the development of dermatitis resulting from the sensitization of humans and animals to Culicoides salivary antigens.
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PMID:Identification of a salivary vasodilator in the primary North American vector of bluetongue viruses, Culicoides variipennis. 931 53