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A study was done on the distereofacial selectivity in reactions of substituted cyclohexyl radicals. Results show that only substituents bound at the olefinic center are attacked by cyclohexyl radicals and influence the equatorial-axial selectivity. Increased axial attack is caused by substituents bound to the radical center while equatorial beta-substituents or axial gamma-substituents increase the amount of equatorial attack.

Objective To define the impact of nuchal cord on the measurement of fetal nuchal translucency thickness (NT). Methods Between December 2004 and June 2006, we examined prospectively 53 fetuses that were observed on routine first-trimester ultrasound examination between 11 + 3 and 13 + 6 weeks of gestation to have nuchal cord causing an indentation in the skin in the nuchal region. The fetuses were re-examined after a median interval of 132 min, when the cord was no longer around the neck and indentation of the skin had resolved. Various NT measurements (highest, lowest, mean) with the cord located around the neck (nuchal cord) were compared with NT measurements in the absence of nuchal cord (‘true’ NT) in the same fetuses. Measurements were considered to be equal when they were within mean ± 1.96 SD, defined by our own intraobserver repeatability according to the method of Bland and Altman. Results The mean of the largest and the smallest of six measurements in the presence of nuchal cord fell within the mean ± 1.96 SD of our own intraobserver repeatability, i.e. gave a correct estimate of the true NT, in 80% of fetuses, while the NT was overestimated in 10% and underestimated in 10% of fetuses. The largest and the smallest of six measurements in the presence of nuchal cord gave an underestimate of the true NT in 2% of fetuses and an overestimate in 4% of fetuses, respectively. Conclusion There is a wide scattering of measurements in fetuses with nuchal cord in comparison to the same fetuses in the absence of nuchal cord. This prevents accurate prediction of the true NT, although the largest and smallest of repeat measurements with nuchal cord can allow calculation of the highest and lowest possible risks, respectively. These facts must be taken into consideration in counseling patients. [ABSTRACT FROM AUTHOR]

The non-steroidal, bis-acylhydrazine agonists of the insect molting hormone, 20-hydroxyecdysone, were first discovered over ten years ago. An extensive structure-activity optimization program yielded one commercial insecticide, tebufenozide (RH-5992) and two additional candidate insecticides (methoxyfenozide and halofenozide) which are in development. Tebufenozide is highly selective for lepidopteran pest control and is thus useful for IPM and resistance management programs. Methoxyfenozide (RH-2485) is also lepidopteran-selective but significantly more potent than tebufenozide and offers control of a wider rangeof lepidopteran pests. Halofenozide (RH-0345) is generally less potent and selective than tebufenozide or methoxyfenozide. However, its physical and biological properties make it well suited for control of beetle grubs and caterpillars in the soil. Target pest selectivity, new and novel mode of action, ecotoxicological safety and safety to beneficial arthropods make these insecticides valuable tools for integrated pest and resistance management programs. (c) 1999 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Thymic stromal lymphopoietin (TSLP) endows human blood-derived CD11c(+) dendritic cells (DCs) and Langerhans cells (LCs) obtained from human epidermis with the capacity to induce pro-allergic T cells. In this study, we investigated the effect of TSLP on umbilical cord blood CD34(+) -derived LC-like cells. These cells are often used as model cells for LCs obtained from epidermis. Under the influence of TSLP, both cell types differed in several ways. As defined by CD83, CD80 and CD86, TSLP did not increase maturation of LC-like cells when compared with freshly isolated LCs and epidermal émigrés. Differences were also found in the production of chemokine (C-C motif) ligand (CCL)17. LCs made this chemokine only when primed by TSLP and further stimulated by CD40 ligation. In contrast, LC-like cells released CCL17 in response to CD40 ligation, irrespective of a prior treatment with TSLP. Moreover, the CCL17 levels secreted by LC-like cells were at least five times higher than those from migratory LCs. After maturation with a cytokine cocktail consisting of tumour necrosis factor-α, interleukin (IL)-1β, IL-6 and prostaglandin (PG)E(2) LC-like cells released IL-12p70 in response to CD40 ligation. Most importantly and in contrast to LC, TSLP-treated LC-like cells did not induce a pro-allergic cytokine pattern in helper T cells. Due to their different cytokine secretion and the different cytokine production they induce in naïve T cells, we conclude that one has to be cautious to take LC-like cells as a paradigm for 'real' LCs from the epidermis., (© 2011 The Authors Journal compilation © 2011 Foundation for Cellular and Molecular Medicine/Blackwell Publishing Ltd.)