Evaluation of WHO monoclonal antibody kit for diagnosis of acute respiratory viral infections

Isovaleryl-CoA dehydrogenase (IVD) catalyzes the conversion of isovaleryl-CoA to 3-methylcrotonyl-CoA in the leucine catabolism pathway. The cDNA encoding the mature human IVD polypeptide was cloned in a prokaryotic expression vector, but the level of expression in Escherichia coli was extremely low and attempts to purify the enzyme to homogeneity were unsuccessful. To enhance expression, the nucleotide sequence of 22 codons within the 111-bp region at the 5'-end of the cDNA was altered to accommodate E. coli codon usage without altering the amino-acid coding sequence. The altered IVD cDNA was synthesized by PCR, using a primer containing the desired modifications. Following overnight induction of the E. coli transformed with this cDNA, the enzyme was purified to homogeneity using diethylaminoethyl agarose and high-pressure ceramic hydroxyapatite resins. IVD activity was increased 165-fold in the crude extract of cells containing the modified cDNA, as compared to that containing the wild-type cDNA.     

Should curative surgery be attempted in patients with cancer of the main stem bronchus?

Among tumors of the lung, main stem bronchial cancer offers a particularly unfavorable prognosis, probably because of its rapid extension to the segmental bronchi, trachea, and extrapulmonary structures. However, analysis of data gathered by the End Results Group indicates that survival among those patients with main stem bronchial cancer whose tumor was resected was virtually the same as that of patients with resectable lung cancer of other sites. From these data it is impossible to assess what role, if any, the resection itself played, and a randomized trial would be necessary to determine whether resection improves the probability of patient survival. On the other hand, it is not now advisable to deny resection to patients with operable main stem bronchial tumors (except oat cell tumors) on the basis of the available nonexperimental evidence alone.     

Optimization of the nutrient medium for Actinomyces spheroides--producer of proteolytic enzymes with fibrinolytic activity

Optimization of the medium for growing Actinomyces spheroides producing proteolytic exoenzymes with the fibrinolytic activity was performed by the method of mathematical planning. The composition of the medium is as follows (%): glucose 7.1, sodium citrate, trisubstituted, 0.48; (NH4)2SO4, 0.15; MgSO4, 0.575; KH2PO4, 0.2; ZnSO4, 0.001; FeSO4, 0.002. The fibrinolytic activity of the cultural broth on this medium is three times as high as on the initial medium (7142 units). Changes in the ratio between components of the medium lead to changes in the ratio between the fibrinolytic and caseinolytic activities. Therefore, Act. spheroides, strain 1, produces exoenzymes which differ by their substrate specificity. The ratio between the fibrinolytic and caseinolytic activities of the complex on the optimized medium is twice as high as on the initial medium.