Formation of a Novel Macrocyclic Alkaloid from the Unnatural Farnesyl Diphosphate Analogue Anilinogeranyl Diphosphate by 5-Epi-Aristolochene Synthase.

As part of an effort to identify substrate analogs suitable for helping to resolve structural features important for terpene synthases, the inhibition of 5-epi-aristolochene biosynthesis from farnesyl diphosphate (FPP) by the tobacco 5-epi-aristolochene synthase incubated with anilinogeranyl diphosphate (AGPP) was examined. The apparent noncompetitive nature of the inhibition supported further assessment of how AGPP might be bound to crystallographic forms of the enzyme. Surprisingly, the bound form of the inhibitor appeared to have undergone a cyclization event consistent with the native mechanism associated with FPP catalysis.

Incidence and prevention of delirium in critical care patients.

Delirium in the intensive care unit is prevalent and a topic of high interest. Although it has been studied a great deal, screening, prevention, and management remain difficult. There are many causes of delirium and equally as many approaches to prevention and treatment.

Reflections from an Undergraduate Student Peer Facilitator in the Team Up for Healthy Living School-Based Obesity Prevention Project.

was a cluster-randomized trial to evaluate a cross-peer school-based obesity prevention program in Southern Appalachia. Undergraduate students from the disciplines of Kinesiology, Nutrition, and Public Health were trained as peer facilitators to deliver an 8-week curriculum in high school classes. The focus of the curriculum was on improving diet and physical activity with an additional emphasis on enhancing leadership and communication skills.

Stitched α-helical peptides via bis ring-closing metathesis.

Conformationally stabilized α-helical peptides are capable of inhibiting disease-relevant intracellular or extracellular protein-protein interactions in vivo. We have previously reported that the employment of ring-closing metathesis to introduce a single all-hydrocarbon staple along one face of an α-helical peptide greatly increases α-helical content, binding affinity to a target protein, cell penetration through active transport, and resistance to proteolytic degradation. In an effort to improve upon this technology for stabilizing a peptide in a bioactive α-helical conformation, we report the discovery of an efficient and selective bis ring-closing metathesis reaction leading to peptides bearing multiple contiguous staples connected by a central spiro ring junction.

Concussion management in collegiate student-athletes: return-to-academics recommendations.

Concussions in collegiate athletics can affect student-athletes both on the field and in the classroom. As policies are made to outline return-to-play decisions and timelines, this article will make the case that return-to-academics should also be included and follow a step-wise protocol. Complete cognitive rest is a cornerstone of concussion recovery and slow reintroduction to academics should precede return-to-play.

Cotyledon-Generated Auxin Is Required for Shade-Induced Hypocotyl Growth in Brassica rapa.

Plant architecture is optimized for the local light environment. In response to foliar shade or neighbor proximity (low red to far-red light), some plant species exhibit shade-avoiding phenotypes, including increased stem and hypocotyl growth, which increases the likelihood of outgrowing competitor plants. If shade persists, early flowering and the reallocation of growth resources to stem elongation ultimately affect the yield of harvestable tissues in crop species.

Enforced presentation of an extrahelical guanine to the lesion recognition pocket of human 8-oxoguanine glycosylase, hOGG1.

A poorly understood aspect of DNA repair proteins is their ability to identify exceedingly rare sites of damage embedded in a large excess of nearly identical undamaged DNA, while catalyzing repair only at the damaged sites. Progress toward understanding this problem has been made by comparing the structures and biochemical behavior of these enzymes when they are presented with either a target lesion or a corresponding undamaged nucleobase. Trapping and analyzing such DNA-protein complexes is particularly difficult in the case of base extrusion DNA repair proteins because of the complexity of the repair reaction, which involves extrusion of the target base from DNA followed by its insertion into the active site where glycosidic bond cleavage is catalyzed.

Hidden in plain sight: subtle effects of the 8-oxoguanine lesion on the structure, dynamics, and thermodynamics of a 15-base pair oligodeoxynucleotide duplex.

The base lesion 8-oxoguanine is formed readily by oxidation of DNA, potentially leading to G → T transversion mutations. Despite the apparent similarity of 8-oxoguanine-cytosine base pairs to normal guanine-cytosine base pairs, cellular base excision repair systems effectively recognize the lesion base. Here we apply several techniques to examine a single 8-oxoguanine lesion at the center of a nonpalindromic 15-mer duplex oligonucleotide in an effort to determine what, if anything, distinguishes an 8-oxoguanine-cytosine (8oxoG-C) base pair from a normal base pair.

Nitrous oxide emission from denitrification in stream and river networks.

Nitrous oxide (N(2)O) is a potent greenhouse gas that contributes to climate change and stratospheric ozone destruction. Anthropogenic nitrogen (N) loading to river networks is a potentially important source of N(2)O via microbial denitrification that converts N to N(2)O and dinitrogen (N(2)). The fraction of denitrified N that escapes as N(2)O rather than N(2) (i.

Decomposition of leaf litter from a native tree and an actinorhizal invasive across riparian habitats.

Dynamics of nutrient exchange between floodplains and rivers have been altered by changes in flow management and proliferation of nonnative plants. We tested the hypothesis that the nonnative, actinorhizal tree, Russian olive (Elaeagnus angustifolia), alters dynamics of leaf litter decomposition compared to native cottonwood (Populus deltoides ssp. wislizeni) along the Rio Grande, a river with a modified flow regime, in central New Mexico (U.

Endogenous and exogenous control of ecosystem function: N cycling in headwater streams.

Allochthonous inputs act as resource subsidies to many ecosystems, where they exert strong influences on metabolism and material cycling. At the same time, metabolic theory proposes endogenous thermal control independent of resource supply. To address the relative importance of exogenous and endogenous influences, we quantified spatial and temporal variation in ecosystem metabolism and nitrogen (N) uptake using seasonal releases of 15N as nitrate in six streams differing in riparian-stream interaction and metabolic character.

Stoichiometry of soil enzyme activity at global scale.

Extracellular enzymes are the proximate agents of organic matter decomposition and measures of these activities can be used as indicators of microbial nutrient demand. We conducted a global-scale meta-analysis of the seven-most widely measured soil enzyme activities, using data from 40 ecosystems. The activities of beta-1,4-glucosidase, cellobiohydrolase, beta-1,4-N-acetylglucosaminidase and phosphatase g(-1) soil increased with organic matter concentration; leucine aminopeptidase, phenol oxidase and peroxidase activities showed no relationship.

Stream denitrification across biomes and its response to anthropogenic nitrate loading.

Anthropogenic addition of bioavailable nitrogen to the biosphere is increasing and terrestrial ecosystems are becoming increasingly nitrogen-saturated, causing more bioavailable nitrogen to enter groundwater and surface waters. Large-scale nitrogen budgets show that an average of about 20-25 per cent of the nitrogen added to the biosphere is exported from rivers to the ocean or inland basins, indicating that substantial sinks for nitrogen must exist in the landscape. Streams and rivers may themselves be important sinks for bioavailable nitrogen owing to their hydrological connections with terrestrial systems, high rates of biological activity, and streambed sediment environments that favour microbial denitrification.

A practical stroke severity scale predicts hospital outcomes.

Goal: To develop a practical severity scale (Wake Forest Stroke Severity Scale [WFSSS]) to predict acute hospital outcomes and resource use after acute ischemic stroke based on the admission neurologic exam.

Background: A useful scheme enabling physicians and other health care providers to stratify stroke severity on admission to predict acute hospital outcomes and improve efficiency of inpatient care has not been described.

Methods: The study subjects consisted of 271 consecutive acute stroke patients admitted to the neurology department from July 1995 to June 1996 who were prospectively examined and whose stroke severity was classified on the basis of admission neurologic exam (level of consciousness, strength, dysphasia, neglect, and gait) as mild, moderate, or severe, based on the WFSSS.

Microbial responses to long-term N deposition in a semiarid grassland.

Nitrogen (N) enrichment of the biosphere is an expanding problem to which arid ecosystems may be particularly sensitive. In semiarid grasslands, scarce precipitation uncouples plant and microbial activities, and creates within the soil a spatial mosaic of rhizosphere and cyanobacterial crust communities. We investigated the impact of elevated N deposition on these soil microbial communities at a grama-dominated study site located incentral New Mexico (USA).

The use of buck and ram extenders and two packaging systems to cryopreserve aoudad (Ammotragus lervia) spermatozoa.

Because the aoudad has been hunted to near extinction, cryopreservation of their semen would be useful for DNA conservation and for the possible re-establishment of captive bred animals to their former ranges. This study was conducted to investigate the effectiveness of cryopreserving aoudad spermatozoa. Semen samples from four post-pubertal animals were collected using electro-ejaculation.

The in-training examination in obstetrics and gynecology: an attempt to establish a remediation indicator.

Objective: With the use of a university- and community hospital-based faculty, we attempted to determine at what performance level remediation would be recommended.

Study Design: The Committee on In-Training Examinations for Residents in Obstetrics and Gynecology Task Force on Standard-Based Scoring sent the 1991 examination to 16 university- and 12 community hospital-based faculty members. Given a standardized definition of a "borderline third-year resident," each faculty scored each item on the examination on whether that hypothetic resident would or would not correctly answer the item.

Modified resazurin reduction test for determining the fertility potential of bovine spermatozoa.

The objective of this study was to determine if reduction of the dye resazurin by bovine sperm is associated with the concentration of motile and progressively motile sperm. Metabolically active sperm reduce resazurin (blue color) to resorufin (pink color) and upon further reduction to dihydroresorufin (white color). A total of 68 semen samples from 20 Limousin bulls were collected using electroejaculation.

Chorionic villus sampling: the University of Maryland experience.

The University of Maryland was the first program in the state to offer chorionic villus sampling (CVS). Since the program's beginning in 1984, 998 patients have been seen with successful sampling in 99.1 percent, using both transcervical and transabdominal approaches.

Creating a unit-specific charging system.

A totally nurse-dependent charging system developed specifically for the labor and delivery suite at the University of Maryland Medical System is described in the article. This easy and effective method of charging was incorporated into an already existing patient census and classification system. The number of relative value units has increased by more than 30%, and the amount of revenue billed has increased by more than $800,000 in the first 10 months after implementation.

Modulation of mannose receptor activity by proteolysis.

Macrophages express a receptor on the cell surface that functions to clear glycoproteins from the extracellular milieu. The activity of this receptor is sensitive to treatment with trypsin. In inflammatory situations, macrophages are activated and exposed to increased levels of extracellular proteases.

Ovarian pregnancy diagnosed after a failed midtrimester therapeutic abortion. A case report.

Ovarian pregnancy is a rare phenomenon. Its presentation often is difficult to distinguish from that of tubal ectopic pregnancy and hemorrhagic ovarian cyst. A patient had an ovarian pregnancy diagnosed following failed midtrimester therapeutic abortion in a suspected bicornuate uterus.