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

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.
Selective recovery of deranged water-holding properties by stratum corneum lipids.

Abstract: The apolipoprotein B-100 (apoB-100) gene in leukocytes and the apoB-100 messenger RNA (mRNA) and translated apolipoprotein in the livers from normal and abetalipoproteinemic individuals were evaluated. Four complementary DNA probes for apoB-100 covering the 5', middle, and 3' regions of the apoB-100 mRNA were utilized and Southern blot analysis indicated that the apoB-100 gene is present in abetalipoproteinemia without major insertions or deletions. Polyadenylated hepatic apoB-100 mRNA from two abetalipoproteinemic patients was normal in size, and the concentration of apoB-100 mRNA was increased sixfold compared with control hepatic apoB-100 mRNA levels. ApoB-100 was detected in hepatocytes of abetalipoproteinemic patients by immunohistochemical techniques. These results indicate that the biochemical defect in abetalipoproteinemic patients studied is most consistent with a posttranslational defect in apoB-100 processing or secretion with an up-regulation of the apoB-100 mRNA.
Analysis of the apolipoprotein B gene and messenger ribonucleic acid in abetalipoproteinemia.

Abstract: Twenty-three male Black African and 23 male Caucasian subjects, ascertained as sedentary, participated in this study designed to determine whether there were differences in skeletal muscle histochemical and biochemical characteristics between racial groups. Muscle fiber type proportions (I, IIa, and IIb), fiber areas and activities of several enzyme markers of different energy metabolic pathways were determined from a biopsy of the vastus lateralis. Results indicated that Caucasians had a higher percent type I (8%, P less than 0.01) and a lower percent type IIa (6.7%, P less than 0.05) fiber proportions than Africans. No significant differences were observed between the two racial groups in the type IIb fiber proportion or in the three fiber type areas. Enzymes catalyzing reactions in phosphagenic [creatine kinase (CK)] and glycolytic [hexokinase (HK), phosphofructokinase (PFK), and lactate dehydrogenase (LDH)] metabolic pathways had significantly higher activities (about 30-40%) in the Black African group than in the Caucasian group (P less than 0.01). No significant difference was noted in the activities of oxidative enzymes [malate dehydrogenase (MDH), oxoglutarate dehydrogenase (OGDH), and 3-hydroxyacyl-CoA dehydrogenase (HADH)]. Consequently, the PFK/OGDH ratio was significantly elevated in Africans (P less than 0.05). The racial differences observed between Africans and Caucasians in fiber type proportion and enzyme activities of the phosphagenic and glycolytic metabolic pathways may well result from inherited variation. These data suggest that sedentary male Black individuals are, in terms of skeletal muscle characteristics, well endowed for sport events of short duration.
Skeletal muscle characteristics in sedentary black and Caucasian males.