Obstrução recorrente das vias aéreas em muares: relato de três casos Airway recurrent obstruction in mules: report of three cases

Relatam-se três casos de obstrução recorrente das vias aéreas em muares com idade média de 10 anos. Os animais eram utilizados para concurso de marcha e criados em campo. Após serem mantidos em cocheiras com cama de serragem e alimentados com feno (tifton e alfafa) e ração comercial, começaram a manifestar intolerância ao exercício e episódios de tosse durante o exercício. Após exames clínico e laboratorial, instituiu-se terapia à base de clenbuterol, dexametazona e bromexina, além de controle ambiental. Após 21 dias de tratamento, ocorreu remissão dos sintomas clínicos. Para comprovação diagnóstica, os animais foram submetidos ao desafio ambiental, por um período de dois dias. Após o tratamento, os três animais voltaram a desempenhar suas atividades atléticas de modo satisfatório.<br>Three cases of airway recurrent obstruction in approximately 10-year-old mules are reported. The animals were raised free and used for marching competitions. After being stabled in boxes under a wood scrape bed and fed on tifton and alfalfa hay plus a commercial ration, they started to show intolerance to exercise and episodes of coughing during it. After clinical and laboratorial examinations, clenbuterol, dexametazone and bromexine were administrated, besides controlling the environment. After 21 days of treatment, the clinical symptoms ceased. In order to certify that diagnosis, the animals were submitted to an environmental challenge for two days. Then, the animals were back to their normal athletic activities in a satisfactory manner

[Abstract] [Full Text] [PDF] Gene Expression in Asthmatic Airway Smooth Muscle

in human tissue

An Unusual Transduction Pathway in Human Tonic Smooth Muscle Myosin

The motor protein myosin binds actin and ATP, producing work by causing relative translation of the proteins while transducing ATP free energy. Smooth muscle myosin has one of four heavy chains encoded by the MYH11 gene that differ at the C-terminus and in the active site for ATPase due to alternate splicing. A seven-amino-acid active site insert in phasic muscle myosin is absent from the tonic isoform. Fluorescence increase in the nucleotide sensitive tryptophan (NST) accompanies nucleotide binding and hydrolysis in several myosin isoforms implying it results from a common origin within the motor. A wild-type tonic myosin (smA) construct of the enzymatic head domain (subfragment 1 or S1) has seven tryptophan residues and nucleotide-induced fluorescence enhancement like other myosins. Three smA mutants probe the molecular basis for the fluorescence enhancement. W506+ contains one tryptophan at position 506 homologous to the NST in other myosins. W506F has the native tryptophans except phenylalanine replaces W506, and W506+(Y499F) is W506+ with phenylalanine replacing Y499. W506+ lacks nucleotide-induced fluorescence enhancement probably eliminating W506 as the NST. W506F has impaired ATPase activity but retains nucleotide-induced fluorescence enhancement. Y499F replacement in W506+ partially rescues nucleotide sensitivity demonstrating the role of Y499 as an NST facilitator. The exceptional response of W506 to active site conformation opens the possibility that phasic and tonic isoforms differ in how influences from active site ATPase propagate through the protein network