Zebrafish microRNA-126 determines hematopoietic cell fate through c-Myb.

Precise regulatory mechanisms are required to appropriately modulate the cellular levels of transcription factors controlling cell fate decisions during blood cell development. In this study, we show that miR-126 is a novel physiological regulator of the proto-oncogene c-myb during definitive hematopoiesis. We show that knockdown of miR-126 results in increased c-Myb levels and promotes erythropoiesis at the expense of thrombopoiesis in vivo. We further provide evidence that specification of thrombocyte versus erythrocyte cell lineages is altered by the concerted activities of the microRNAs (miRNAs) miR-126 and miR-150. Both miRNAs are required but not sufficient individually to precisely regulate the cell fate decision between erythroid and megakaryocytic lineages during definitive hematopoiesis in vivo. These results support the notion that miRNAs not only function to provide precision to developmental programs but also are essential determinants in the control of variable potential functions of a single gene during hematopoiesis.

Specialized care for twin gestations: improving newborn outcomes and reducing costs.

OBJECTIVE: To compare newborn outcomes and costs of hospital stays for twins born to mothers receiving care in a specialized twin clinic with a research-based care protocol and one consistent caregiver versus twins whose mothers received standard prenatal care. DESIGN AND SETTING: A retrospective, historical cohort study conducted in a high-risk obstetric clinic in central Texas. PATIENTS: Thirty women pregnant with twins received specialized care. The comparison group consisted of 41 women pregnant with twins who received standard care. INTERVENTIONS: An advanced practice nurse provided prenatal care, which included weekly clinic visits, home visits, and 24-hour availability for phone support. OUTCOME MEASURES: Gestational age at birth, birth weight, length of stay in the neonatal intensive-care unit (NICU), and hospital charges for the newborns. RESULTS: No newborns of less than 30 weeks gestation were born to women in the specialized care group, the mean birth weight was 249 g (SD +/- 77) higher, days in the NICU were reduced from a mean of 17 to 7, and hospital charges were $30,000 less per infant. CONCLUSIONS: Newborn outcomes were improved and length of stay and hospital charges were significantly reduced for newborns whose mothers had received care in the specialized twin clinic.

Biomaterial surfaces.

The nature of a biomaterial surface governs the processes involved in biological response. Surface properties such as surface chemistry, surface energy, and morphology may be measured in order to understand the surface region of a biomaterial. In this article, we describe the surface characteristics of a few common biomaterials, review the techniques used to measure surface properties, and discuss the application of surface information in developing novel and improved biomaterials.