RESUMEN
Mouse sciatic nerves were subjected to devascularization, M. leprae inoculation, and combined insult of devascularization + footpad inoculation (FPI). Changes were seen in FPI nerves only after eight months, but in cases of combined insult, changes were evident in hours. Both the groups showed initial loss of small myelinated fibres. No proliferation of Schwann cells was in FPI nerves, but in combined insult it was maximum after two weeks. Presence of M. leprae seems to be arresting Schwann cell activity after two weeks. Blood vessels showed increased endothelial cell cytoplasm, basement membrane proliferation and villi formation. These changes seem to be specific of endoneurial blood vessels of leprosy nerves. Increased number of mast cells seems to be specific of devascularized and FPI nerves. Increased number of macrophages expressed low immunity of devascularized nerves. Eosinophils migrated to endoneurium as a result of leakage of axoplasm.
Asunto(s)
Lepra/patología , Mycobacterium leprae/fisiología , Nervio Ciático/patología , Animales , Recuento de Células , División Celular , Ratones , Microscopía Electrónica , Vaina de Mielina/microbiología , Vaina de Mielina/patología , Vaina de Mielina/ultraestructura , Fibras Nerviosas/microbiología , Fibras Nerviosas/patología , Fibras Nerviosas/ultraestructura , Regeneración Nerviosa , Células de Schwann/microbiología , Células de Schwann/patología , Nervio Ciático/irrigación sanguínea , Nervio Ciático/microbiología , Nervio Ciático/ultraestructuraRESUMEN
A series of mutations was carried out with Aspergillus niger NCIM-616 as the parent strain. A mutant strain NG-4 with 28% increased beta-galactosidase productivity was produced with N-methyl-N-nitro-N-nitrosoguanidine (NTG) at 1500 micrograms ml-1 concentration and exposure time of 60 min. This mutant yielded a third generation u.v.-treated strain, UV-5 with a 117.6% increase in beta-galactosidase productivity with respect to the parent strain.