PubMed · 9064360
The source did not provide an abstract. Follow the original record for more information.
Explore connections, maps & timelines
R O West. 1997. Warm stethoscope.. https://pubmed.ncbi.nlm.nih.gov/9064360/
Cite the original work for its findings. Save a collection to share your selection of sources.
KEEP EXPLORING
We observed that serum contains a factor(s) that inhibits the induction of peroxisome proliferator-activated receptor-gamma (PPARgamma) by 15-deoxy-Delta(12,14)-PGJ(2) (15dJ(2)). Ten percent FBS reduces 15dJ(2) induction of PPARgamma from over 150-fold to less than 15-fold in EP-JEG cells, a stably transfected choriocarcinoma cell line that expresses endogenous PPARgamma. By contrast, rosiglitazone, an unrelated pharmacological agonist of PPARgamma, is not inhibited by serum in this cell line. We have identified the inhibitory principal in serum as albumin. Serum albumin binds 15dJ(2) with a dissociation constant of 870 +/- 70 nM, effectively reducing the concentration of 15dJ(2) available to PPARgamma. Heat treatment of serum abolishes the inhibition, providing a way to test eicosanoid compounds independently of albumin's inhibitory effect. It is reasonable to assume that 15dJ(2) or structurally similar compounds or metabolites are the endogenous activators of PPARgamma. Therefore, albumin may be an important regulator of PPARgamma function in vivo.
The use of thermal denaturation of proteins prior to in-solution digestion and mass spectral peptide mass mapping is reported. Thermal denaturation is preferred over chemical denaturation because it does not require purification/concentration prior to mass spectral analysis. Enzymatic digestions of proteins that are resistant to proteolysis are significantly enhanced by thermal denaturation. Native proteins that are sensitive to proteolysis show similar or slightly lower digestion yields following thermal denaturation. Proteins that are resistant to digestion become more susceptible to digestion, independent of protein size, following thermal denaturation. For example, amino acid sequence coverage from digest fragments increases from 15 to 86% in myoglobin and from 0 to 43% in ovalbumin. This leads to more rapid and reliable protein identification by MALDI peptide mass mapping. Although some proteins aggregate upon thermal denaturation, the protein aggregates are easily digested by trypsin and generate sufficient numbers of digest fragments for protein identification.
This work studies the effect of thermal and dehydration kinetics on the viability of Saccharomyces cerevisiae. The influence of the rate of temperature (T) and osmotic pressure (pi) increases are first investigated. Results showed that yeast viability is preserved by slow variations of temperature or osmotic pressure in a precise range of T or pi. The influence of a previous thermal stress on the resistance to a hyperosmotic stress is also studied. Temperatures equal to or lower than 10 degrees C allowed the preservation of viability after an osmotic stress whereas temperatures above 10 degrees C did not preserve yeast survival.