RESUMO
A peptide toxin was isolated from the venom of Palamneus gravimanus, the Indian black scorpion, to block human Kv1.1 channels expressed in Xenopus laevis oocytes. A 4.5 kD peptide (toxin), as confirmed by SDS-PAGE, was purified to homogeneity by ion exchange chromatography using CM-Sephadex C-25 followed by Sephadex G-50 gel filtration. Palamneus gravimanus toxin (PGT) selectively blocks the human cloned voltage-gated potassium channel hKv1.1 in a two-electrode voltage-clamp (TEVC) technique. The results obtained indicate that the toxin blocks the hKv1.1 channel at a nanomolar concentration range (Ki value of 10 nM) of the peptide to the external side of the cell. The blockage seems to be voltage-dependent. Comparative structure of PGT (a 4.5 kD peptide) with BTK-2 suggests a close relationship; therefore this toxin can be employed to investigate the hKv1.1 channel structure.
RESUMO
A peptide toxin was isolated from the venom of Palamneus gravimanus, the Indian black scorpion, to block human Kv1.1 channels expressed in Xenopus laevis oocytes. A 4.5 kD peptide (toxin), as confirmed by SDS-PAGE, was purified to homogeneity by ion exchange chromatography using CM-Sephadex C-25 followed by Sephadex G-50 gel filtration. Palamneus gravimanus toxin (PGT) selectively blocks the human cloned voltage-gated potassium channel hKv1.1 in a two-electrode voltage-clamp (TEVC) technique. The results obtained indicate that the toxin blocks the hKv1.1 channel at a nanomolar concentration range (Ki value of 10 nM) of the peptide to the external side of the cell. The blockage seems to be voltage-dependent. Comparative structure of PGT (a 4.5 kD peptide) with BTK-2 suggests a close relationship; therefore this toxin can be employed to investigate the hKv1.1 channel structure.
RESUMO
This randomized, double-blind trial compared the efficacy of nebulized epinephrine with salbutamol in the treatment of infants with acute bronchiolitis. The mean percent oxygen saturation at 60 minutes was significantly higher in the epinephrine group. Thirty-three percent of the patients in epinephrine group were admitted to the hospital compared with 81% of the salbutamol group (p = 0.003). We conclude that nebulized epinephrine is more efficacious than salbutamol for infants with acute bronchiolitis seen in an emergency department.
Assuntos
Albuterol/uso terapêutico , Bronquiolite/tratamento farmacológico , Epinefrina/uso terapêutico , Doença Aguda , Aerossóis , Albuterol/administração & dosagem , Método Duplo-Cego , Epinefrina/administração & dosagem , Humanos , Lactente , Resultado do TratamentoRESUMO
A further report on inoculation work with splenectomized monkeys is made, and the difficulty in producing disseminated lesions in that animal is stressed. The apparent success of the first experiment, previously reported, has not been repeated. It is suggested that one of the reasons for the failure of development of leprosy in experimental animals is that resistance develops after multiple inoculations, as shown by the strngly positive lepromin reaction that developed in most of our animals which had had more than one inoculation. Some support to this hypothesis is given by the postmortem results in monkey 13, in which there was apparent dissemination of the leprosy bacilli inoculated, but it cannot be claimed that this animal developed leprosy. In two animals, both of which had been fed on colocasia, an acid-fast diphtheroid was found. In both of them erythematous lesions developed, and both showed signs of paralysis. Reasons for believing that the organism encountered was not M.leprae are given. No definite conclusion on this finding can be drawn because it was noted that an acid-fast bacillus, similar in morphology to that obtained from the erythematous lesion, can be demonstrated occasionally in the eyebrow of the normal monkey. The only definite inference that can be drawn from these experiments is that in monkey 1 of the previous series, and in monkey 13 of this series, there was evidence that the leprosy bacilli had become disseminated. There was, however, no evidence that progressive lesions had developed anf therefore none that leprosy was actually produced.