Hydrogel coated monoliths for enzymatic hydrolysis of penicillin G

The objective of this work was to develop a hydrogel-coated monolith for the entrapment of penicillin G acylase (E. coli, PGA). After screening of different hydrogels, chitosan was chosen as the carrier material for the preparation of monolithic biocatalysts. This protocol leads to active immobilized biocatalysts for the enzymatic hydrolysis of penicillin G (PenG). The monolithic biocatalyst was tested in a monolith loop reactor (MLR) and compared with conventional reactor systems using free PGA, and a commercially available immobilized PGA. The optimal immobilization protocol was found to be 5 g l−1 PGA, 1% chitosan, 1.1% glutaraldehyde and pH 7. Final PGA loading on glass plates was 29 mg ml−1 gel. For 400 cpsi monoliths, the final PGA loading on functionalized monoliths was 36 mg ml−1 gel. The observed volumetric reaction rate in the MLR was 0.79 mol s−1 m−3monolith. Apart from an initial drop in activity due to wash out of PGA at higher ionic strength, no decrease in activity was observed after five subsequent activity test runs. The storage stability of the biocatalysts is at least a month without loss of activity. Although the monolithic biocatalyst as used in the MLR is still outperformed by the current industrial catalyst (immobilized preparation of PGA, 4.5 mol s−1 m−3catalyst), the rate per gel volume is slightly higher for monolithic catalysts. Good activity and improved mechanical strength make the monolithic bioreactor an interesting alternative that deserves further investigation for this application. Although moderate internal diffusion limitations have been observed inside the gel beads and in the gel layer on the monolith channel, this is not the main reason for the large differences in reactor performance that were observed. The pH drop over the reactor as a result of the chosen method for pH control results in a decreased performance of both the MLR and the packed bed reactor compared to the batch system. A different reactor configuration including an optimal pH profile is required to increase the reactor performance. The monolithic stirrer reactor would be an interesting alternative to improve the performance of the monolith-PGA combination

Closed posteromedial dislocation of the tibiotalar joint without fracture in a basketball player

Etude de cas et revue de littératur

Exercise induced compartment syndrome in a professional footballer

PubMedID: 15039267Recurrent pain in the lower leg caused by exercise is a common problem in athletes. The main causes are exercise induced compartment syndrome, periostitis of the tibia, stress fracture, venous diseases, obliterative arterial diseases, and shin splints. Exercise induced compartment syndrome is the least common. A recurrent tightening or tense sensation and aching in anatomically defined compartments is pathognomonic. The symptoms are caused by abnormally high pressure in compartments of the leg during and after exercise, in this report, a case of exercise induced compartment syndrome in a professional footballer is described

Hand grip strength in patients with type 2 diabetes mellitus

Conclusion: Hand grip strength and key pinch power values were found to be lower in patients with T2DM than in age-matched control subjects. Hands, as well as feet, are also affected by diabetes and physicians should be aware of this. (c) 2005 Elsevier Ireland Ltd. All rights reserved

Comparison of ultrasonography and radiography in assessment of the heel pad compressibility index of patients with plantar heel pain syndrome. Measurement of the fat pad in plantar heel pain syndrome.

Conclusion. - Measuring unloaded and loaded heel pad thickness by ultrasonography is reliable in the adult feet with heel pain. The preference of ultrasonography is reasonable in the studies involving the heel fat pad. (c) 2006 Elsevier SAS. All rights reserved