PubMed Health⌕ Search

Biomedical subjects

L H Muschel

Publications and source records attributed to L H Muschel.

At least 19 recordsLinked to original sources
PubMed1976

Follow-up of American Cancer Society Special Postdoctoral Research Fellowship recipients.

A follow-up study of the 44 recipients of American Cancer Society, Inc., Special Postdoctoral Research Fellowship from 1962 to 1973 revealed that 11 of 21 M.D. candidates obtained their second (Ph.D.) degree at the end of training. By contrast, all but one among the 23 Ph.D. candidates were awarded the second (M.D.) degree. A great majority of either group remain in active research, regardless of whether or not they obtained the second degree. A very high percentage of their research is cancer related.

American Cancer Society↗
PubMed1975

Antileptospiral activity in lower-vertebrate sera.

Normal serum from the painted turtle (Chrysemys picta), the snapping turtle (Chelydra serpentina), and the frog (Rana pipiens) were found to possess bactericidal activity towards Leptospira. Leptospires from both the parasitic and biflexa complexes were killed by these sera at high dilutions. This pattern differs from that of mammalian serum, as generally only the biflexa complex leptospires are killed by normal mammalian serum. The activity in C. picta serum was characterized as being complement dependent and not mediated by basic proteins. Because comple-inactivated C. picta serum regained leptospiricidal activity after the addition of fresh rabbit serum, antibody is also likely to participate in the killing activity. Further support that C. picta serum contained leptospiral antibodies was found by the detection of serotype-specific agglutinins.

Animals↗
PubMed1969

Sensitivity of Pseudomonas aeruginosa to normal serum and to polymyxin.

Strains of Pseudomonas aeruginosa isolated from clinical material were very variable in their sensitivity to the bactericidal action of normal serum mediated by the complement system. Fifty per cent killing end points ranged from 0.015 ml to greater than 0.4 ml. Most of the strains with relatively greater sensitivity to serum were isolated from patients with cystic fibrosis. Immunization of rabbits resulted in antisera with enhanced levels of bactericidal antibody, except with one strain which was resistant to the bactericidal action of normal serum and antiserum. When P. aeruginosa was cultivated at 41 C instead of at 37 C, it was significantly more sensitive to serum and to several antibiotics, thereby implicating fever as a host defense mechanism in Pseudomonas infections. In contrast to their heterogeneity to serum bactericidal activity, the strains were relatively homogeneous in their sensitivity to polymyxin, with no apparent association between their sensitivity to the two antimicrobial agents.

Animals↗
PubMed1968

Antibiotic, detergent, and complement sensitivity of Salmonella typhi after ethylenediaminetetraacetic acid treatment.

Antimicrobial substances, including antibiotics such as polymyxin and novobiocin, detergents, and complement, all of which are known or presumed to have an effect upon membrane permeability, showed greater potency against ethylenediaminetetraacetic acid (EDTA)-treated Salmonella typhi than against untreated cells of that organism. The differential effect was particularly marked with the complement system when serum antibody was limiting. EDTA-treated cells were also more susceptible to penicillin and bacitracin. On the other hand, such treatment did not affect the potency against S. typhi of mitomycin C, the aminoglycosides, chloramphenicol, and chlortetracycline, nor did it affect the permeability of S. typhi to these compounds.

Animals↗
PubMed1968

Effect of lysogeny on serum sensitivity.

When Escherichia coli K-12 was infected with lambda phage and mutants of lambda characterized by the production of temperature-sensitive repressors, the lysogenic bacteria were significantly more resistant to normal serum than the uninfected organisms. Infection of E. coli K-12 with a lambdoid phage, phi80, whose prophage attachment site is different from that of lambda, did not result in a detectable change in serum resistance. Similarly, infection with certain Pseudomonas and Shigella phages caused no detectable differences in serum resistance. Finally, the well-known conversion of the Salmonella anatum serotype to S. newington by E(15) phage indicated that, despite the relatively greater roughness of S. anatum, S. newington was more sensitive to normal serum than S. anatum. Thus, the effects of lysogeny on the sensitivity of bacteria to the bactericidal action of serum mediated by the complement system may be quite variable.

Bacteriophages↗