Human Labor Pain Is Influenced by the Voltage-Gated Potassium Channel KV6.4 Subunit.

By studying healthy women who do not request analgesia during their first delivery, we investigate genetic effects on labor pain. Such women have normal sensory and psychometric test results, except for significantly higher cuff pressure pain. We find an excess of heterozygotes carrying the rare allele of SNP rs140124801 in KCNG4. The rare variant KV6.4-Met419 has a dominant-negative effect and cannot modulate the voltage dependence of KV2.1 inactivation because it fails to traffic to the plasma membrane. In vivo, Kcng4 (KV6.4) expression occurs in 40% of retrograde-labeled mouse uterine sensory neurons, all of which express KV2.1, and over 90% express the nociceptor genes Trpv1 and Scn10a. In neurons overexpressing KV6.4-Met419, the voltage dependence of inactivation for KV2.1 is more depolarized compared with neurons overexpressing KV6.4. Finally, KV6.4-Met419-overexpressing neurons have a higher action potential threshold. We conclude that KV6.4 can influence human labor pain by modulating the excitability of uterine nociceptors.MCL, DKM, DW, and CGW acknowledge funding from Addenbrooke’s Charitable Trust and the NIHR Cambridge Biomedical Research Centre. MN was funded by the Wellcome Trust (200183/Z/15/Z); JH and ESS by a Rosetrees Postdoctoral Grant (A1296) and the BBSRC (BB/R006210/1); GC and ESS by Versus Arthritis Grants (RG21973); VBL and FR by the Wellcome Trust (106262/Z/14/Z and 106263/Z/14/Z) and a joint MRC programme within the Metabolic Diseases Unit (MRC_MC_UU_12012/3). EF, GI and CB were funded by the Cambridge NIHR Biomedical Research Centre Integrative Genomics theme and LAP by a BBSRC-funded studentship (BB/M011194/1)

Egg removal and intraspecific brood parasitism in the European starling ( Sturnus vulgaris )

From 1983 to 1986 we monitored 284 European starling ( Sturnus vulgaris ) nests in New Jersey for evidence of intraspecific brood parasitism and egg removal during the laying period. Egg removal occurred significantly more often at nests where intraspecific brood parasitism was detected (12 of 35 nests, 34%) than at unparasitized nests (23 of 249 nests, 9%). Brood parasitism (92% of parasitized nests) and egg removal (74% of nests with egg removal) were most common at nests where egg laying began in April of each year (i.e., early nests). Egg removal occurred at 26 (19%) and brood parasitism at 32 (23%) of 138 early nests. Both brood parasitism and egg removal were concentrated during the first four days in the laying period when brood parasitism is most likely to be successful and when host nests are most vulnerable to parasitism (Romagnano 1987). Both parasitism and removal usually involved a single egg at each nest. We detected brood parasitism and egg removal on the same day at five of 12 nests (42%) where both were observed. Because starlings do not remove foreign eggs from their nests once they begin laying (Stouffer et al. 1987) we hypothesize that parasite females sometimes removed host eggs while parasitizing nests.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46889/1/265_2004_Article_BF00295201.pd

Lutein-fortified infant formula fed to healthy term infants: evaluation of growth effects and safety

<p>Abstract</p> <p>Background/Objectives</p> <p>Breast milk contains lutein derived from the mother's diet. This carotenoid is currently not added to infant formula, which has a small and variable lutein content from innate ingredients. This study was conducted to compare the growth of infants fed lutein-fortified infant formula with that of infants fed infant formula without lutein fortification.</p> <p>Subjects/Methods</p> <p>This 16-week study was prospective, randomized, controlled, and double-blind with parallel groups of healthy term infants fed either control formula (Wyeth S-26 Gold, designated as Gold) or experimental formula (Wyeth S-26 Gold fortified with lutein at 200 mcg/l, designated as Gold + Lutein). Two hundred thirty-two (232) infants ≤ 14 days postnatal age were randomized and 220 (94.8%) completed the study. Weight (g), head circumference (cm), and length (cm) were measured at Weeks 4, 8, 12, and 16. The primary endpoint was weight gain (g/day) from baseline to Week 16. Safety was assessed through monitoring of study events (SEs) throughout the study and evaluation of selected blood chemistry tests performed at Week 16.</p> <p>Results</p> <p>Infants in both treatment groups demonstrated appropriate growth. No differences between treatment groups were found in any of the measures of growth at any of the measurement time points. Both study formulas were well tolerated. The mean values of all measured blood chemistry parameters fell within the modified normal ranges for infants, and the values for both groups for any measured parameter were similar.</p> <p>Conclusions</p> <p>Infants fed lutein-fortified S-26 Gold demonstrated growth equivalent to that of infants fed unfortified lutein formula.</p