In the last several years, the use of double-stranded DNA templates together with thermostable-polymerase PCR has essentially replaced the use single-stranded DNA templates using the thermolabile polymerase for in vitro mutagenesis. Numerous PCR methods are now available, such as overlap-extension PCR, megaprimer PCR, and inverse PCR. All these PCR methods are reliable, effective, and convenien...

A case of severe systemic reactions (intense itching, urticaria, confusion, blurred vision, transient loss of consciousness, sweating, tachycardia) after ingestion of raw or lightly-cooked onion is described. The patient, a 44-year-old woman, had no troubles with well-cooked onions. Differently from the cases of sensitivity to onion described in literature, this patient was monosensitized, bein...

The biochemical basis for sulfite accumulation by sulfate-using revertants of Salmonella pullorum was determined. All of the sulfate-using mutants isolated from wild-type S. pullorum accumulated sulfite when grown at 37 but not at 25 C. The specific activity of reduced nicotinamide adenine dinucleotide (NADPH)-dependent sulfite reductase (H2S-NADP oxidoreductase, EC 1.8.1.2) and of reduced meth...

background : cockroaches have been recognized as a powerful indoor allergen. cockroach allergy can be a major factor in seri­ous asthma and nasal allergy. bioinformatics tools have been developed to identify potential allergens. the present study was conducted to identify potential allergens in  periplaneta americana (linnaeus). methods : the study focused on the identification of potential all...

allergy to prosopis juliflora (mesquite) pollen is one of the common causes of respiratory allergy in tropical countries. mesquite is widely used as street trees in towns and ornamental shade trees in parks and gardens throughout arid and semiarid regions of iran. the inhalation of mesquite pollen and several species of amaranthus/chenopodiaceae family is the most important cause of allergic re...

In an assay measuring virus-directed RNA synthesis, infection of BHK cells by a standard test dose of vesicular stomatitis virus (VSV) was inhibited by ultraviolet light-irradiated wt VSV and by ts 045, one of a number of thermolabile, temperature-sensitive G protein mutants of VSV. After heat treatment for 1 h at 45 degrees C, the thermolabile mutants were no longer able to inhibit the VSV inf...

W e have isolated temperature resistant revertants from temperature sensitive E. coli strains containing either a thermolabile g lutaminyltRNA synthetase or leucyl-tRNA synthetase. Among the revertants which still contained the thermolabile leucyl-tRNA shynthetase w e found two classes of regulatory mutants (leuX and leuY) which have elevated levels of this enzyme. T h e leuX mutation specifies...

Temperature sensitivity of the regulatory protein coded by nifA prevents the organism from utilizing N2 at 37 degrees C. The purpling of 6-cyanopurine, a function of nifA expression, also is thermolabile.