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Biomedical subjects

P Farrar

Publications and source records attributed to P Farrar.

4 recordsLinked to original sources
PubMed1996

Tissue distribution of three members of the murine protein disulfide isomerase (PDI) family.

The distribution of PDI, ERp61 and ERp72, members of the protein disulfide isomerase (PDI) family of endoplasmic reticulum (ER) proteins, was determined in various murine tissues. Relative amounts of mRNA were measured using a quantitative reverse transcription-polymerase chain reaction (RT-PCR) method. Protein levels were determined from Western blots. In most tissues, protein levels paralleled the amount of mRNA for each PDI family member. The tissue distribution of the PDI and ERp72 mRNAs was similar, although ERp72 was not as abundant as PDI in the tissues. The tissue distribution of the ERp61 mRNA was significantly different from the two other family members. To help define potential hormonal or maturational differences in the regulation of expression of PDI family members, mRNA was measured in the frontal cortex, liver, pituitary gland and uterus at timed intervals during postnatal maturation. Except in the pituitary gland, the mRNA levels at 10 days and 22 days after birth were essentially identical to those in the adult. The ERp61 and ERp72 mRNAs were present at 2- to 3-fold higher levels in the pituitary glands of the 10- and 22-day-old mice, than in the adult mice. In addition, the pituitary gland PDI mRNA was 2- to 3-fold higher in 10-day-old mice than in adults. In general, levels of PDI family members were higher in secretory tissues than in other tissues in both immature and adult mice.

Age Factors↗
PubMed1981

Nonenzymatic glycosylation of low density lipoproteins in vitro. Effects on cell-interactive properties.

Atherosclerosis occurs at an accelerated rate in patients with diabetes mellitus. Since some proteins undergo nonenzymatic glycosylation in diabetic patients and because certain chemical modifications of low density lipoproteins produced alterations in their interactions with certain cultured cells, a fact that may be relevant to atherogenesis, we investigated the effect of in vitro glycosylation on cell-related properties of low density lipoproteins. Glycosylation was carried out by incubating LDL (1-10 mg LDL-protein/ml) with glucose (0-100 mM) in 0.5 M phosphate buffer, pH 8.0, at 37 degrees C. The amount of glucose incorporated into LDL after 1-2 wk of incubation was estimated to be in the range of 1-10 mol/mol LDL-protein. Amino acid analysis of glycosylated LDL showed that glucose was covalently bound to lysine residues. In studies with cultured human fibroblasts, glycosylated LDL was internalized and degraded significantly less than control LDL, in proportion to the estimated degree of glycosylation (12% of control for the most extensively glycosylated LDL). Glycosylation of LDL also impaired significantly its ability to stimulate cholesteryl ester synthesis by cultured fibroblasts. Glycosylated LDL did not stimulate cholesteryl ester synthesis in rat peritoneal macrophages. If glycosylation of LDL occurs in diabetic patients, some pathophysiologic consequences related to the increased incidence of atherosclerosis in these patients may result.

Arteriosclerosis↗
PubMed1977

The visual world behind the head.

After a 5-minute inspection of 7 objects laid out on a shelf, subjects were seated with the objects behind them and answered questions about the locations and orientations of objects by throwing a switch left or right. The "visual image" subjects were told to imagine that the objects were still in front of them and to respond accordingly. The "real space" (RS) subjects were told to respond in terms of the positions of the objects in real space behind them. Thus correct responses (left vs. right) were completely opposite for the 2 groups. A control group responded while facing a curtain concealing the objects. The task was harder, by time and error criteria, for group RS than for the other 2 groups, but not dramatically so. All RS subjects denied using a response-reversal strategy. Some reported translating the objects from back to front and thus responding as to a mirror-image of the array. When this evasion was discouraged, RS subjects typically reported responding in terms of visual images located behind them and viewed as if by "eyes in the back of the head." The paradox of a visual image that corresponds to no possible visual input is discussed.

Functional Laterality↗