Oocyte aging in a marine protostome worm: The roles of maturation-promoting factor and extracellular signal regulated kinase form of mitogen-activated protein kinase.

The roles of maturation-promoting factor (MPF) and an extracellular signal regulated kinase form of mitogen-activated protein kinase (ERK MAPK) are analyzed during oocyte aging in the marine protostome worm Cerebratulus. About a day after removal from the ovary, unfertilized metaphase-I-arrested oocytes of Cerebratulus begin to flatten and swell before eventually lysing, thereby exhibiting characteristics of a necroptotic mode of regulated cell death. Based on immunoblots probed with phospho-specific antibodies, MPF and ERK are initially active in freshly mature specimens.

Dihydro-β-agarofuran sesquiterpenes from celastraceae species as anti-tumour-promoting agents: Structure-activity relationship.

Inhibition of tumour promotion in multistage chemical carcinogenesis is considered a promising strategy for cancer chemoprevention. In an ongoing investigation of bioactive secondary metabolites from Celastraceae species, five new dihydro-β-agarofuran sesquiterpenes (1-5), named Chiapens A-E, and seventeen known ones, were isolated from Maytenus chiapensis. Their structures were elucidated by extensive NMR spectroscopic and mass spectrometric techniques, and their absolute configurations were determined by circular dichroism studies, chemical correlations and biogenic means.

The association between lead and micronutrient status, and children's sleep, classroom behavior, and activity.

The role of lead exposure or micronutrient deficiencies in children's sleep problems is unknown. Although elevated blood lead concentrations (BPb) are clearly related to behavior problems in children, few researchers have used objective observations. The authors investigated relationships between lead, micronutrient status, sleep, classroom behavior, and activity in Mexican children aged 6-8 years living close to a metal foundry.

Biological evaluation, structure-activity relationships, and three-dimensional quantitative structure-activity relationship studies of dihydro-beta-agarofuran sesquiterpenes as modulators of P-glycoprotein-dependent multidrug resistance.

Multidrug resistance (MDR) is one of the main challenges in the chemotherapy of cancer, malaria, and other important diseases. Here, we report the inhibitory activity of a series of 76 dihydro-beta-agarofuran sesquiterpenes, tested on NIH-3T3 cells expressing the human P-glycoprotein (Pgp) multidrug transporter, to establish quantitative comparisons of their respective abilities to block the drug transport activity. The screening was performed on the basis of the ability of sesquiterpenes to modulate the intracellular accumulation of the classical Pgp substrate daunorubicin.

Antitumor-promoting effects of new sesquiterpenes from Crossopetalum tonduzii.

Seven new sesquiterpenes (1-7) with a 'dihydro-beta-agarofuran' (= 5,11-epoxy-5beta,10alpha-eudesmane) skeleton were isolated from Crossopetalum tonduzii. Their structures were elucidated spectroscopically, especially by means of homo- and heteronuclear NMR correlation (COSY, ROESY, HSQC, and HMBC). The absolute configurations of the new compounds were determined by circular dichroism (CD) studies and by chemical correlations via the derivatives 8-11.

Reversion of human Pgp-dependent multidrug resistance by new sesquiterpenes from Zinowiewia costaricensis.

In an intensive study of South American medicinal plants, herein we report the isolation, structure elucidation and biological activity of fourteen new and five known dihydro-beta-agarofuran sesquiterpenes from the leaves of Zinowiewia costaricensis (1-19). Their structures were determined by means of (1)H and (13)C NMR spectroscopic studies, including homonuclear and heteronuclear correlation experiments. The absolute configurations of the new compounds were determined by CD studies, chemical correlations or biogenetic grounds.

Evaluation of a unique, nurse-inserted, peripherally inserted central catheter program.

Background: Concerns regarding the safety and success of peripherally inserted central catheters (PICCs) placed at the bedside in the pediatric population initially precluded the development of a nurse-inserted PICC program at our pediatric center. Previously, all PICCs were inserted by interventional radiologists (IRs) with fluoroscopic guidance. A new nurse-inserted PICC program was initiated with collaboration between PICC nurses and IRs.