Role of retinol in protecting epithelial cell damage induced by Clostridium difficile toxin A

Vitamin A (retinol), a fat-soluble vitamin, is an essential nutrient for the normal functioning of the visual system, epithelial cell integrity and growth, immunity, and reproduction. Our group has investigated the effect of high doses of oral vitamin A on early childhood diarrhea in our prospective community-based studies from Northeast Brazil and found a beneficial role in reducing the mean duration but not incidence of diarrheal episodes. In this study, we explored the role of retinol supplementation in intestinal cell lines following Clostridium difficile toxin A (TxA) challenge. C. difficile is the most common anaerobic pathogen borne with antibiotic-borne diarrhea and pseudomembranous colitis. Since retinol is critical for the integrity of tight junctions and to modulate the cell cycle, we have focused on changes in transepithelial electrical resistance (TEER) in Caco-2, a more differentiated intestinal cell line, and on models of cell proliferation, migration and viability in IEC-6 cells, an undifferentiated crypt cell line, following TxA injury. In this model, retinol therapy reduced apoptosis, improved cell migration and proliferation, and prevented the reduction in TEER, following C. difficile TxA challenge in a glutamine-free medium. These results suggest the role of retinol in protecting intestinal epithelial barrier function from C. difficile TxA enterotoxic damage.     

THE NATIONAL BIRTH CENTER STUDY Part II—Intrapartum and Immediate Postpartum and Neonatal Care

Part II of a three-part report of the National Birth Center Study describes care provided to 11,814 women and their newborns during and after labor and delivery until they were transferred or discharged from the birth centers. There were few low birth weight or preterm or postterm births, but more macrosomic babies than among all U.S. births during the same time period. Certified nurse-midwives provided most of the intrapartum care, which is described in the context of medically recommended standards and data that describe care provided to low-risk women giving birth in U.S. hospitals. Birth center care deviated from typical hospital care in several ways. Birth center clients were much less likely to receive central nervous system depressants, anesthesia, continuous electronic fetal monitoring, induction and/or augmentation of labor, intravenous infusions, amniotomies, or episiotomies, and they had relatively few vaginal examinations. They were more likely to eat solid food during labor and to take showers and/or baths Nulliparity was strongly associated with longer first stage labors and longer labor was associated with more frequent use of many kinds of interventions. Infant birth weight, mother's position during delivery, and forceps- or vacuum-assisted deliveries are examined in relation to episiotomies and lacerations and tears.     

Notes on parasitism by Amblyomma humerale (Acari: Ixodidae) in the state of Rondônia,western Amazon,Brazil

The tick Amblyomma humerale Koch is endemic to South America. All host records refer to the adult stage parasitizing tortoises, mostly yellow-footed tortoise, Geochelone denticulata (L.), and red-footed tortoise, Geochelone carbonaria (Spix). The current study reports the presence of A. humerale in the state of Rond?nia, Brazil. A total of 215 adult ticks (201 males, 14 females) was collected from six G denticulata in an Indian reserve and nine Geochelone sp. in rural Monte Negro County, giving an overall mean infestation of 14.3 +/- 12.0 (range: 2-44) ticks per tortoise. Male ticks always outnumbered females on the host and nine tortoises had only male ticks. Male ticks were mostly attached in clusters on the ventral sides of the carapace near the anterior and posterior margins, and more rarely on the outer margin of the plastron. All females were found attached to the tortoise skin, at different sites such as head, neck, shoulders or legs. Male ticks were rarely observed attached to the body skin. Seven engorged nymphs collected on small vertebrates from Monte Negro County molted to adults of A. humerale. This included one nymph each on the seven-colored lizard, Plica plica (L), green tree climber, Plica umbra (L.), and wide-foraging lizard, Kentropyx calcarata Spix,three nymphs on the common opossum, Didelphis marsupialis L., and one nymph on the silky anteater, Cyclopes didactylus L. These constitute the first host records for the immature stages of the tick A. humerale.     

Liquid-Crystal-Enabled Active Plasmonics: A Review

Liquid crystals are a promising candidate for development of active plasmonics due to their large birefringence, low driving threshold, and versatile driving methods. We review recent progress on the interdisciplinary research field of liquid crystal based plasmonics. The research scope of this field is to build the next generation of reconfigurable plasmonic devices by combining liquid crystals with plasmonic nanostructures. Various active plasmonic devices, such as switches, modulators, color filters, absorbers, have been demonstrated. This review is structured to cover active plasmonic devices from two aspects: functionalities and driven methods. We hope this review would provide basic knowledge for a new researcher to get familiar with the field, and serve as a reference for experienced researchers to keep up the current research trends.