RESUMO
A number of allotypic markers of the rabbit immunoglobulins are present only on intact immunoglobulin molecules and not on the isolated heavy or light chains. Some of these markers, although determined by the kappa light chain, are limited to a single heavy chain class of Ig. They can be generated by in vitro hybridization of the kappa light chain with the appropriate heavy chain. The quaternary IgG allotypic determinants Gs3 and Gs7 which are determined respectively by the b4.1 and b4.2 allelic variants of the kappa b4 light chain can be generated not only by in vitro hybridization of these light chains with a rabbit gamma chain, but also to a certain extent by their hybridization to gamma chains derived from other species.
Assuntos
Epitopos/análise , Hibridomas/imunologia , Alótipos de Imunoglobulina/biossíntese , Imunoglobulina G , Animais , Eletroforese em Gel de Poliacrilamida , Imunodifusão , Cadeias Pesadas de Imunoglobulinas/genética , Cadeias Leves de Imunoglobulina/genética , Cadeias kappa de Imunoglobulina , Camundongos , CoelhosRESUMO
The in vitro sensitivity of 104 isolates of Neisseria gonorrhoeae to six antimicrobial agents was tested. More than 50% of the isolates produced penicillinase. Of those that did not produce penicillinase, 26% were resistant (minimum inhibitory concentration (MIC)) greater than or equal to 0.5 mg/l), and 68% showed a decreased sensitivity for penicillin G (0.06 less than or equal to MIC less than or equal to 0.25 mg/l). Twenty six per cent and 50% of the strains, respectively, showed a decreased sensitivity to thiamphenicol (MIC greater than or equal to 1 mg/l) and tetracycline (MIC greater than or equal to 2 mg/l). All isolates were sensitive to spectinomycin, kanamycin, and norfloxacin. Of 20 penicillinase producing N gonorrhoeae (PPNG) isolates examined, seven contained the 3.4 megadalton R-plasmid, another seven contained both the 3.4 megadalton and 22.5 megadalton plasmids, five the 4.3 megadalton and 22.5 megadalton plasmids, and one isolate harboured both the 3.4 and 4.3 R-plasmids, together with the 22.5 megadalton plasmid. A disturbing increase in resistance to penicillin has been observed since the publication of earlier surveys, and the clinical implications of these findings are discussed.