Asparaginases are the cornerstone therapy of many successful combination regimens for the treatment of acute lymphoblastic leukemia (ALL), the most common malignancy in children and adolescents. The aim of this work was to produce recombinant Erwinia carotovora L-asparaginase II in Escherichia coli fed-batch cultures. Using a robust fed-batch technique with pre-determined exponential feeding rates, our bioreactor culture system yielded 30.7 grams of dry cell weight and 0.9 grams of soluble rErAII protein per liter of culture broth. The homogeneous rErAII activity was determined by isothermal titration calorimetry (ITC). The enzyme Km values for the main substrates L-Asn and L-Gln were 33x10-6 M and 10x10-3 M, respectively. Our work shows that it is possible to produce an active homogeneous rErAII enzyme in the soluble cell fraction through IPTG-induced E. coli fed-batch cultivation.

In the CNS, NPY has been implicated in obesity and feeding, endocrine function and metabolism. Potent and selective rNPY antagonists will be able to probe the merits of this approach for the treatment of obesity. We report the synthesis and preliminary evaluation of some hydrazide derivatives as antagonists of rNPY.

Objetivo: Este estudo prospectivo compara as imagens de microscopia confocal do epitélio corneano do coelho e do homem, obtidas através de 2 objetivas com aberturas numéricas (AN) diferentes. Métodos: Dez olhos de coelhos foram enucleados e fixados através de um suporte pneumático para garantir o melhor desempenho de cada objetiva. Cinco pacientes normais foram selecionados após consentimento. Os olhos de coelhos e dos pacientes foram previamente examinados na lâmpada de fenda. O exame de microscopia confocal (Tomey, Erlangen-Tennenlohe, Alemanha) foi realizado com as objetivas Achroplan 40x/AN = 0,75 e 63x/AN = 0,9 (Zeiss, Oberkochen, Alemanha). Imagens selecionadas do epitélio corneano foram avaliadas qualitativamente com relação ao tamanho, forma e refletividade das células. Resultados: As células no epitélio superficial dos coelhos e dos pacientes, previamente à descamação, tiveram uma refletividade maior que as células adjacentes. Este aspecto foi claramente observado somente com a objetiva 63x/AN = 0,9. As camadas basal e intermediária do epitélio em coelhos foram visualizadas somente através desta objetiva. Estas camadas nos pacientes tornaram-se mais nítidas com a objetiva de abertura numérica maior (63x/AN = 0,9). Conclusão: Uma objetiva de abertura numérica elevada produz melhor resolução dos cortes ópticos, facilitando a análise das camadas do epitélio no coelho e no homem.

Purpose: The prospective study compares the confocal microscopic images of the rabbit and human corneal epithelial layers obtained with two objectives having different numerical apertures (NA). Methods: Ten rabbit eyes were enucleated and kept in place by a pneumatic support to ensure the best performance of each objective, with no disturbance due to eye movements. Five normal patients were selected after agreement. The rabbit eyes and those of the patients were all examined with slit lamp. Confocal microscopy (Tomey, Erlangen-Tennenlohe, Germany) was performed with Achroplan (Zeiss, Oberkochen, Germany) 40x/NA = 0.75 and 63x/NA = 0.9 objectives. Selected images of the corneal epithelium layers were evaluated qualitatively for the size, shape, light scattering, and reflection of the cells. Results: The cells in the superficial corneal epithelium of rabbit and human eyes, before desquamation, produced a much brighter reflection than the surrounding cells. This was clearly seen only with the 63x/NA = 0.9 objective. The corneal epithelium subsegments of the rabbit eyes, like the basal cell layer or the intermediate cell layer (wing cells), were visible under the high numerical aperture (63x/NA = 0.9) objective only. These layers, in the human eyes, were more clearly visible using the high numerical aperture objective. Conclusion: An objective with a high numerical aperture and a high optical resolution provided an improved analysis to study all the layers of the rabbit and human corneal epithelium.