Perrigo (Sweden)

SummaryBackgroundEczema (atopic dermatitis; AD) is a very common itchy skin condition affecting 1 in 5 children and up to 1 in 10 adults worldwide. The skin of eczema sufferers is prone to redness, irritation and dryness because it does not form an effective barrier, i.e. the ability of the skin to stop irritants, allergens and microorganisms getting into the body. Skin barrier dysfunction is a hallmark of AD. The regular and liberal (600 g/week for an adult) use of emollients is recommended for all patients with eczema), even between episodes of itching and redness, to soften and soothe the skin. In England alone, almost 9 million prescriptions for emollient creams were issued in 2018, at a cost of over £50 million. Despite this widespread use, relatively little is known about how commonly prescribed emollient creams affect the skin's barrier, and thus the role of moisturizers in AD development and progression remains unclear. We set out to compare three different types of emollient cream and a no‐treatment control.AimTo compare the barrier‐strengthening properties of a new moisturizer containing urea and glycerol (urea–glycerol cream; UGC), with those of a glycerol‐containing moisturizer (glycerol cream; GC), a simple paraffin cream (PC) with no humectant, and a no‐treatment control (NTC).MethodsThis was an observer‐blinded prospective Phase 2 within‐subject multilateral single‐centre randomized controlled trial in adults with AD (Clinical Trials #NCT03901144). The intervention involved 4 weeks of treatment, twice daily, with the three products applied to one of four areas on the forearms the (the fourth area was the untreated control, randomized allocation). Skin properties [dryness, transepidermal water loss (TEWL), hydration and natural moisturizing factor (NMF) levels] were assessed before, during and after treatment to see what happened to the skin's barrier. The primary outcome was skin sensitivity to the irritant sodium lauryl sulfate (SLS) after treatment. We performed tests on the skin before and after treatment to see what happened to the skin's barrier.ResultsIn total, 49 patients were randomized, completed treatment and included in the analysis. UGC significantly reduced the response to SLS as indicated by a reduction in TEWL compared with NTC (−9.0 g/m2/h; 95% CI −12.56 to −5.49), with PC (−9.0 g/m2/h; 95% CI −12.60 to −5.44) and with GC −4.2 g/m2/h; 95% CI 7.76 to −0.63). Skin moisturization improved at sites treated with UGC compared with NTC and PC, and this was accompanied by concordant changes in dryness and NMF levels. Subgroup analysis suggested FLG‐dependent enhancement of treatment effects.ConclusionThe study showed that not all emollient creams for eczema are equal. The simple paraffin‐based emollient, which represents the most widely prescribed type of emollient cream in England, had no effect on the skin's barrier and reduced the skin's NMF. UGC markedly improved the skin's barrier and protected against irritation. GC performed better than PC, but not as well as UGC. UGC strengthened the skin barrier through a mechanism involving increased NMF levels in the skin, and imparted protection from SLS‐induced irritation. By helping correct a major pathophysiological process, UGC has the potential to improve the long‐term control of AD. The results show that different emollient creams have different effects on our skin, and only certain types have the ability to improve the skin's barrier and protect against irritants that trigger eczema.

The study of the strength properties of single wood fibers has gained momentum in recent years due to their potential exploitation as reinforcement in composite materials, and the possible selective logging of trees for lumber and paper production. The present study focuses on the relationship between the microfibril angle and the strength properties of fibers between different parts of a section of the trunk of a black spruce tree. Single fibers, approximately 2–3 mm in length, were extracted in small sections from a single trees inner growth rings (5–7) and outer growth rings (40–50) and chest height using a sharp razor blade. These sections were macerated in 20 ml glacial acetic acid and 20 ml hydrogen peroxide (100 vol.) using a reflux apparatus. This maceration process was left for 48 h after which the samples were thoroughly washed using distilled water. The fibers, now white in appearance due to the removal of lignin, were then transferred to a storage jar. At all times fibers remained wet. Fibers were removed in solution, using a pipette, and transferred to a glass slide. Under a microscope, individual fibers were observed and removed from the solution using ultra-fine tipped tweezers. These fibers were then transferred to a fiber rack and micro-droplets of DEVCONTM epoxy and hardener (in equal volumes) were applied to either end of the fibers, following a method devised by Kersavage [1] and further developed by Mott [2]. Single fibers were then transferred to a MINIMATTM system with customized fiber grips allowing tensile testing. Each fiber was tested with a cross-head speed of 0.5 mm/min and the maximum jaw separation was set at 3 mm to allow for complete fracture. Data obtained for 40 tensile tests of black spruce fibers taken from the inner and outer ring portions are shown in Table I. Typical load-elongation curves for black spruce fibers are shown in Fig. 1. It is clear that they show linear elasticity. Some fibers appeared to show “strain-hardening,” whereby the load increased non linearly with elongation. This is thought to occur in fibers which have a high S2 cell wall layer microfibril angle. This will be discussed in more detail later. In total 20 fibers were tested from each section and only from the latewood portions of the rings. The reasoning