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Biomedical subjects

J Rotta

Publications and source records attributed to J Rotta.

At least 55 records · Page 3Linked to original sources
PubMed1971

New approaches for the laboratory recognition of M types of group A streptococci.

The successful classification of Group A streptococci by the capillary precipitin technique requires a complete series of M type antisera which are sufficiently potent and specific to give unequivocal type-specific reactions with all the serotypes. Specific antisera for this purpose have been prepared by absorption with heterologous streptococci. Unabsorbed antisera have been employed here in the Ouchterlony double-diffusion agar-gel test to identify the M type of streptococci. Techniques have been developed for making this method of M typing fully reliable. The results reported here confirm and amplify the original findings of Michael and Massell (3). With crude HCl extracts and unabsorbed M type antisera, a precipitin line due to the M protein and another to the group-specific carbohydrate are the two major reactions observed. These reactions, however, are usually readily distinguishable. There was a surprising lack of cross-reactive precipitin lines due to non-type-specific protein antigens in the extracts. Although many of the unabsorbed M type antisera can be employed in the double-diffusion tests, the group-specific antibody must be removed from some of the unabsorbed antisera to avoid confusing cross-reactions. Absorption of these antibodies has been achieved by means of a specific immunoabsorbent column prepared from para-aminophenyl-beta-N-acetylglucosamine and cyanogen bromide-activated Sepharose. Excellent agreement was observed between the M typing results obtained on 117 field strains by the conventional capillary precipitin method and the Ouchterlony double-diffusion method.

Absorption↗
PubMed1969

Biological properties of cell wall mucopeptide of hemolytic streptococci.

Several of the toxic properties of streptococcal mucopeptide have been studied in detail. Intravenous injection of as little as 1 microg of mucopeptide, solubilized by ultrasonic treatment, elicits a reproducible febrile response. Rabbits which are made tolerant to Escherichia coli endotoxin are only partially tolerant to the subsequent injection of streptococcal mucopeptide. Soluble mucopeptide was successfully employed to prepare and provoke the localized Shwartzman reaction. Intravenous injection of 80 microg of solubilized mucopeptide leads to diffuse cellular infiltration as well as focal areas of myocardial necrosis, surrounded by inflammatory cells.

Animals↗
PubMed1968

The mechanism of the pyrogenic effect of streptococcus cell wall mucopeptide.

1. The intravenous injection into rabbits of 25-50 mug of a preparation of cell-wall mucopeptide (SM) from group A streptococcus produced a rise in rectal temperature and a fall in the number of circulating granulocytes in the blood.2. The pyrogenic response to SM is not dependent on the circulating granulocytes since it occurred also in rabbits made leucopenic by nitrogen mustard (HN 3).3. The pyrogenic response to SM was enhanced after an intravenous injection of 5-hydroxytryptophan (5-HTP).4. Pre-treatment with reserpine caused a much greater attenuation of the pyrogenic response to SM than pre-treatment with alpha-methyl-para-tyrosine (AMPT).5. As the reserpine reduced the 5-hydroxytryptamine (5-HT) and noradrenaline level in the hypothalamus, whereas the AMPT reduced only the noradrenaline level, it is concluded that 5-HT may be involved in the pyrogenic response and the way in which 5-HT may exert this function is discussed.

5-Hydroxytryptophan↗