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In order to improve its stability, immobilized Concanavalin A (Con A) on Toyopearl adsorbents was conjugated with monomethoxy poly(ethylene glycol) succinimidyl propionate (mPEG-SPA) with different molecular weight. A colorimetric method using ninhydrin is proposed to determine the degree of PEGylation; this method has proved to be easy applicable and reproducible. The PEGylation reaction was studied in detail to elucidate how parameters such as molar ratio of mPEG-SPA to Con A and molecular weight of mPEG-SPA affect the degree of PEGylation. The adsorption isotherms of glucose oxidase (GOD) onto native and PEGylated Con A adsorbents showed that the modification did not alter substantially the specificity of the carbohydrate binding ability of Con A. However, the binding capacity for GOD was slightly reduced probably due to the steric hindrance caused by mPEG chains. Adsorption kinetic studies revealed a lower adsorption rate after PEGylation which was attributed to the steric effect. The dynamic adsorption capacity for modified Con A depended very much on the degree of PEGylation and the molecular weight of mPEG derivatives. The adsorption capacity could be highly preserved for Toyopearl Con A modified by mPEG2k (90% of the original adsorption capacity) even with a degree of PEGylation up to 20% (the ratio of primary amino groups of PEGylated immobilized Con A to that of native immobilized Con A). Studies show that the binding capacity of PEGylated Con A was highly preserved under mild process conditions. PEGylated Con A also exhibited obviously higher stability against more stressful conditions such as the exposure to organic solvents and high temperatures. Conjugation of Con A with mPEG2k provided better adsorption performance thus has greater potential for application in affinity separation processes compared with mPEG5k. The fact that PEGylation stabilizes the properties of Con A may greatly expand the range of applications of unstable proteins to bioprocessing (e.g. biocatalysis and downstream separation) as well as other protein applications (e.g. medication, industrial use, etc.).

Item does not contain fulltext A term-born boy presented with a rash immediately post partum, consisting of erosions, crusts and a few vesicles. Skin biopsy showed dermal infiltration of S100 and CD1a immunopositive histiocytes. The diagnosis was 'congenital Langerhans cell histiocytosis of the skin'.

An affinity separation method for the isolation of recombinantly produced benzoylformiate decarboxylase (BFD) is presented based on the interaction of the enzyme to its cofactor. Enzyme/cofactor interactions are well suited for affinity purification processes with regard to its high affinity and selectivity. Problems can be induced due to harsh desorption conditions that probably diminish the activity of the purified enzyme. The implementation of boronic acids to immobilize the cofactor introduces a gentle release by a simple pH shift from 8.5 to 6. The disadvantages of maminophenyl boronic acids are the high nonspecific adsorption induced by the introduction of a positive charge and a hydrophobic phenyl ring. It was shown that the disadvantages prevail and boronic acid resins are not suitable for protein purification from complex matrices. In contrast to the affinity separation method, where the cofactor was directly immobilized onto the support, a better separation performance could be achieved, which is reflected by a purification factor of 4.

A survey questionnaire was administered to employees of a public health agency regarding their involvement with smoking and other life-style behavior. Responses were analyzed and combined with sick leave data to determine the use of sick leave among employees who currently smoke, those who never smoked, and those who formerly smoked. Current smokers took significantly more sick leave than those who have never smoked ("nonsmokers") or former smokers. Using an analysis of variance model, only smoking status, education level, and sex, among selected demographic variables, were significantly related to the amount of sick leave taken. Current smokers took excess sick leave (amounting to nearly $40,000) as compared with nonsmokers and ex-smokers combined over a 21-month period. This study also characterizes the relationship between smoking status and selected life-style behavior. Smokers were less active, less likely to use seat belts, less likely to believe that smoking is related to health, and more likely to be heavier and to eat a poor diet than their nonsmoking or former smoking counterparts. We make suggestions regarding the reduction of smoking and other deleterious behavior as a means of controlling costs and reducing employee morbidity.