BACKGROUND Intrapartum drugs, including fentanyl administered via epidural and synthetic oxytocin, have been previously studied in relation to neonatal outcomes, especially breastfeeding, with conflicting results. We examined the normal neonatal behavior of suckling within the first hour after a vaginal birth while in skin-to-skin contact with mother in relation to these commonly used drugs. Su...

Patterns of infant feeding, basal prolactin concentrations, and ovarian activity were studied longitudinally in 27 breast-feeding mothers from delivery until first ovulation. Suckling frequency (6.1 feeds/day) and suckling duration (122 mins/day) reached peak values four weeks post partum and remained relatively constant until the introduction of supplementary food at a mean of 16 weeks post pa...

We examined in rat pups the relation between the decline of suckling and the emergence of independent ingestion, and the role of milk delivery conditional on nipple attachment in the maintenance of suckling. Fifteen-day-old litters were reared for either 5 or 10 days, and 20-day-old litters for 5 days by either a thelectomized (no nipples), ligated (nipples but no milk), or intact (nipples and ...

Heydrick, Fred P. (Fort Detrick, Frederick, Md.), Ralph F. Wachter, and Henry J. Hearn, Jr. Host influence on the characteristics of Venezuelan equine encephalomyelitis virus. J. Bacteriol. 91:2343-2348. 1966.-Alterations in plaque size, virulence, and lipid content of Venezuelan equine encephalomyelitis (VEE) virus were examined for possible interrelationships among these properties during 10 ...

Dengue virus, type 2, in viremic human sera and after passage in cell cultures produces mixtures of small and large plaques when assayed in LLC-MK2 cells. Clones of dengue virus type 2 obtained by plaque selection in primary green monkey kidney cell cultures were tested for temperature sensitivity in vitro and for virulence by intracerebral inoculation of suckling mice. Sublines of a small-plaq...

0 J. Med. Entomol. 25(6): 493-500 (1988) CJ ABSTRACT -Ecological studies were done in the Pocomoke Cypress Swamp, Worchester Co., Md., to clarify the role of Aedes atlanticus and gray squirrels as enzo6tic hosts of Keystone (KEY) virus. Among 43 seronegative squirrels, 65% were infected with KEY virus during July, August, and September 1975, coincident with the emergence and activity of KEY vir...

Adults and nymphs of a soft tick, Ornithodoros sonrai Sautet & Witkowski, were allowed to feed on suckling mice that had been experimentally infected with Crimean-Congo hemorrhagic fever (CCHF) virus (IbAr 10200 strain). The mean viral titer of mouse blood at the time of tick feeding was 10(3.2) plaque-forming units (PFU) per ml. Samples of ticks were assayed on 12 occasions between days 0 and ...

During the lactation period, mammary epithelial cells secrete large amounts of milk proteins. The coordinate regulation of milk protein expression is effected by the lactogenic hormones. We have investigated the activity of a mammary gland-specific transcription factor (MGF), which mediates hormonal influences at the level of a milk protein gene promoter. MGF-binding sites are present in the pr...

Evidence presented in a previous report (1) showed that a passive immunity is capable of protecting suckling mice against herpes virus instilled intranasally. Because of the wen known neurotropic potentiality of this virus in various host species, it seemed desirable to determine whether the central nervous system (CNS) of suckling mice is invaded by virus entering the organism by the intranasa...

The cyanobacterial neurotoxin β-N-methylamino-L-alanine (BMAA) has been implicated in the etiology of neurodegenerative disease and proposed to be biomagnified in terrestrial and aquatic food chains. We have previously shown that the neonatal period in rats, which in humans corresponds to the last trimester of pregnancy and the first few years of age, is a particularly sensitive period for expo...