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Biomedical subjects

S L Reed

Publications and source records attributed to S L Reed.

44 records · Page 3Linked to original sources
PubMed1985

Effect of theophylline on differentiation of Trypanosoma brucei.

Differentiation of Trypanosoma brucei in the mammal limits the degree of parasitemia and prepares the trypanosome for passage back into the tsetse fly. In an attempt to define the signals that control differentiation, we found that theophylline, in contrast to indomethacin, blocked differentiation, prolonged parasitemia, elevated prostaglandin and cyclic AMP concentrations of rat plasma, and depressed intratrypanosomal cyclic AMP. Relatively nontoxic drugs that alter differentiation are powerful tools for elucidating the events that control this important process.

Aminophylline↗
PubMed1984

Indomethacin promotes differentiation of Trypanosoma brucei.

The treatment of mice with indomethacin lowered Trypanosoma brucei parasitemia 1 to 2 log10 because it quickly promoted the differentiation of rapidly dividing long, slender trypanosomes into short, stumpy forms that do not divide in the mammal but do develop a functional mitochondrion and the ability to infect the tsetse. Since natural resistance correlates with the rate of differentiation, this observation may provide important information about factors that control the severity of trypanosomiasis.

Animals↗
PubMed1983

Resistance to lysis by human serum of pathogenic Entamoeba histolytica.

A comparison was made of susceptibility to lysis by human sera among five non-pathogenic and 11 pathogenic strains of Entamoeba histolytica already characterized into zymodemes. The nonpathogenic strains were found to be uniformly susceptible to lysis. Nine of 11 pathogenic strains, including five strains isolated from liver abscesses, were found to be resistant to lysis by serum under identical conditions. Resistance to complement-mediated lysis may be an inherent property of most pathogenic strains and may prove to be a necessary virulence factor for dissemination.

Blood Physiological Phenomena↗
PubMed1976

Short-lived methylated messenger RNA in mouse kidney.

In experiments originally designed to examine selective turnover of methylated "caps" in renal mRNA, we observed that [3H]methyl label decayed from mRNA containing poly(A) with a half-life of 1-2 hr. (Caps are blocked, methylated mRNA sequences of the general structure m7GpppNm p(1 or 2)Np.). To distinguish between metabolism of short-lived mRNA and discriminate turnover of "caps", we compared residual [3H]methyl label in 5' and 3'mRNA fragments prepared from mRNA isolated during the decay period. Hydrolysis of mRNA at 0 degrees with dilute KOH before oligo(dT)-cellulose selection produced 5' mRNA fragments enriched with an alkali-resistant oligonucleotide with a -5 charge; the 3' mRNA fraction was correspondingly reduced in oligonucleotide content. Since methyl label disappeared at the same rate from both fractions, we conclude that mouse kidney contains short-lived mRNA and that the "caps" of these labile mRNAs turn over with the rest of the mRNA molecule.

Animals↗