Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

[EX Q]: Abstract: Selective removal of stratum corneum lipids following applications of acetone/ether to the human forearm for extremely prolonged periods of 5-20 min induced an enduring (more than 4 days), chapped and scaly appearance of the skin which was accompanied by a significant decrease in the water-holding properties of the stratum corneum. In order to further elucidate the significance of lipids in the water-holding properties, lipids, which were extracted as sebaceous-rich lipids (SL) for the first 10-min acetone/ether treatment and as stratum corneum lipids (SCL) for the additional 30-min treatment, were topically applied daily on lipid-depleted forearm skin which had been pretreated with acetone/ether for 40 min. Two daily applications of the SCL which were solubilized in squalane containing 1% alpha-monomethyl heptadecyl glyceryl ether (GE) caused a significant increase of conductance, accompanied by a marked improvement in the level of scaling as compared with nontreatment or GE/squalane base, whereas the SL in the GE/squalane base did not exhibit any significant recovery in either conductance value or scaling. To clarify which components of the SCL are primarily responsible for the observed recovery of the water-holding properties, chromatographically separated fractions of the SCL were also topically applied in the same manner for 2 successive days. Out of the following separated fractions: cholesterol, cholesterol ester, free fatty acid, glycolipids, and ceramide, 2 daily topical applications of ceramide fraction induced a significant and the highest increase in the conductance value as compared with GE/squalane base. Furthermore, glycolipids and cholesterol fractions also exhibited a significant recovery when compared with no application at all. In contrast, free fatty acid and cholesterol ester fractions did not indicate any significant increase in the conductance value. These findings strengthen the hypothesis that structural lipids present in the intercellular spaces of the stratum corneum, especially ceramide, play a critical role in the water-holding properties of the stratum corneum.
[EX A]: Selective recovery of deranged water-holding properties by stratum corneum lipids.

[EX Q]: Abstract: Gintzler found an abrupt increase in pain thresholds in rats during the last days of gestation. While some data suggest a similar increase in pain thresholds for pregnant women, Goolkasian and Rimer have found, using signal detection procedures, that women are increasingly likely to report stimuli as painful during the last 2 weeks of pregnancy. The present studies were carried out to assess pain and discomfort thresholds in the last weeks of women's pregnancies. In the first study, daily measures of the pressure-induced pain thresholds of 6 women who had spontaneous, vaginal births increased during the last 16 days of pregnancy and exceeded the 300 mm Hg maximum stimulus pressure for the last 9 days of pregnancy. In the second study, the discomfort thresholds of 6 women were measured each day during the last 11 days of pregnancy before spontaneous vaginal births. The discomfort thresholds of the pregnant women were higher than those of 6 non-pregnant women whose discomfort thresholds were also measured each day. Pregnant women's thresholds increased before the onset of labor, while the discomfort thresholds of the non-pregnant women were unchanged during the course of the study. These results extend Gintzler's findings of reduced sensitivity to pain shortly before parturition.
[EX A]: Pain and discomfort thresholds in late pregnancy.

[EX Q]: Abstract: Cell cultures of human keratinocytes contain membrane-associated thioredoxin reductase that is extremely active in reducing radicals on the outer plasma membrane. This enzyme activity was confirmed by its purification from cultures of stratified human keratinocytes by affinity column chromatography. The enzyme was assayed both in vivo and in vitro using a spin-labeled quaternary ammonium compound as the substrate, under saturating conditions in free radical substrate. Specific activities were determined by monitoring the sequential decrease in the amplitude of the electron spin resonance signal per unit of cell protein. The following properties were found: Cultures of adult stratified cells have approximately twice the thioredoxin reductase activity of neonatal cells. The enzyme is inhibited by thioprotein inhibitors (i.e., parachloromecuribenzoate and dinitrochlorobenzene). The activity is regulated by calcium concentrations of the cell culture medium. Stratified keratinocytes are half as active in medium containing 2 mM Ca++ compared with 0.1 mM Ca++ concentration. Product inhibition of the enzyme occurs with oxidized coenzyme NADP+ (i.e., 87% inhibition of enzyme activity over 30 min). The enzyme is heat stable at temperatures of 70 degrees C for 10 min. It is inactivated at 75 degrees C. A comparative study of thioredoxin reductase activity on stratified differentiated and undifferentiated rapidly growing cells was performed. Also, enzyme activity was quantitated for cultured keratinocytes isolated from vitiliginous and normal skin of the same donor. The results of this study, and the connection between this enzyme activity and UV-generated free radicals are reconciled in terms of the mechanism of action and metabolic activity of thioredoxin reductase.
[EX A]:
Free radical reduction by thioredoxin reductase at the surface of normal and vitiliginous human keratinocytes.