Green turtles shape the seascape through grazing patch formation around habitat features: Experimental evidence

Understanding how megaherbivores incorporate habitat features into their foraging behavior is key toward understanding how herbivores shape the surrounding landscape. While the role of habitat structure has been studied within the context of predator-prey dynamics and grazing behavior in terrestrial systems, there is a limited understanding of how structure influences megaherbivore grazing in marine ecosystems. To investigate the response of megaherbivores (green turtles) to habitat features, we experimentally introduced structure at two spatial scales in a shallow seagrass meadow in The Bahamas. Turtle density increased 50-fold (to 311 turtles ha^-1 ) in response to the structures, and turtles were mainly grazing and resting (low vigilance behavior). This resulted in a grazing patch exceeding the size of the experimental setup (242 m² ), with reduced seagrass shoot density and aboveground biomass. After structure removal, turtle density decreased and vigilance increased (more browsing and shorter surfacing times), while seagrass within the patch partly recovered. Even at a small scale (9 m² ), artificial structures altered turtle grazing behavior, resulting in grazing patches in 60% of the plots. Our results demonstrate that marine megaherbivores select habitat features as foraging sites, likely to be a predator refuge, resulting in heterogeneity in seagrass bed structure at the landscape scale.

GIP mediates the incretin effect and glucose tolerance by dual actions on α cells and β cells

Glucose-dependent insulinotropic polypeptide (GIP) communicates nutrient intake from the gut to islets, enabling optimal levels of insulin secretion via the GIP receptor (GIPR) on β cells. The GIPR is also expressed in α cells, and GIP stimulates glucagon secretion; however, the role of this action in the postprandial state is unknown. Here, we demonstrate that GIP potentiates amino acid-stimulated glucagon secretion, documenting a similar nutrient-dependent action to that described in β cells. Moreover, we demonstrate that GIP activity in α cells contributes to insulin secretion by invoking paracrine α to β cell communication. Last, specific loss of GIPR activity in α cells prevents glucagon secretion in response to a meal stimulus, limiting insulin secretion and driving glucose intolerance. Together, these data uncover an important axis by which GIPR activity in α cells is necessary to coordinate the optimal level of both glucagon and insulin secretion to maintain postprandial homeostasis.

Sustained release of a GLP-1 and FGF21 dual agonist from an injectable depot protects mice from obesity and hyperglycemia

There is great interest in identifying a glucagon-like peptide-1 (GLP-1)-based combination therapy that will more effectively promote weight loss in patients with type 2 diabetes. Fibroblast growth factor 21 (FGF21) is a compelling yet previously unexplored drug candidate to combine with GLP-1 due to its thermogenic and insulin-sensitizing effects. Here, we describe the development of a biologic that fuses GLP-1 to FGF21 with an elastin-like polypeptide linker that acts as a sustained release module with zero-order drug release. We show that once-weekly dual-agonist treatment of diabetic mice results in potent weight-reducing effects and enhanced glycemic control that are not observed with either agonist alone. Furthermore, the dual-agonist formulation has superior efficacy compared to a GLP-1/FGF21 mixture, demonstrating the utility of combining two structurally distinct peptides into one multifunctional molecule. We anticipate that these results will spur further investigation into GLP-1/FGF21 multiagonism for the treatment of metabolic disease.

Abstract P5-08-10: Stage-at-presentation and time-to-treatment for American Indian patients diagnosed with breast cancer

Purpose: To review the stage of presentation and time-to-treatment for American Indian (AI) patients diagnosed with breast cancer (BC) and compare them to White (W), Black (B), Asian (AS) and Hawaiian/Polynesian (HP) population across the US and by geographic region using a large national database.

Methods: The NCDB, a joint project of the American Cancer Society and the Commission on Cancer, is a comprehensive national database that registers approximately 70% of cancer patients in the US. Data for patients with BC was extracted from the NCDB 2013 PUF file (2004-2013). Categorical data were compared using the chi-square test. Time-to-treatment (TtT) analysis was performed in patients with non-metastatic breast cancer. All interval parameters were evaluated as continuous variables and compared using ANOVA analysis.

Results: Table 1 shows the number of patients, median age and stage at presentation by race. The median age was lowest for AS and largest for W patients. Compared to W patients, AI patients were less likely to present with stage 0/I disease and more likely to present with stage II/III disease. Similarly, AI patients were 25% more likely to present with metastatic disease when compared to W patients. Table 1 also shows the mean intervals (in days) from diagnosis to treatment. This analysis revealed significant differences amongst the races, with AI patients tending to have the second shortest TtT. Evaluation of the interval to treatment amongst the 9 geographic regions also revealed significant differences. The West North Central and East South Central regions had the shortest TtT and the Pacific and North East regions had the longest. For AI patients, the shortest TtT occurred in the West North Central and South Atlantic while the longest TtT occurred in the North East and West South Central regions. In general, the magnitude of these differences was under 20%, but varied greatly depending on the variables and regions evaluated. These differences were statistically significant (p-value < 0.01).

Conclusion: AI patients presented with later stage disease and longer interval to treatment for all modalities compared to White race, but did better overall than Black patients, both for stage at diagnosis and time to treat. There was considerable regional variation in time intervals across all races. Efforts to improve outcomes should be focused on addressing regional variations in time to treat, and in earlier diagnosis of breast cancer for at risk populations.

Table 1Clinical ParametersAmerican IndianWhiteBlackAsianHawaiin / Polynesianp-valueN4,6341,623,175217,69655,9423,473 Age (Median)5761585556< 0.001Stage 0 (%)17.420.521.425.519.5< 0.001I35.942.031.137.335.8 II31.525.129.025.829.5 III10.78.712.48.510.8 IV4.63.76.12.94.3 Inverval from Diagnosis to: [Mean(Std Dev) in days]Treatment Start32.3 (38.8)27.8 (39.3)35.0 (39.4)31.1 (31.9)31.2 (32.9)< 0.001Definitive Surgical Procedure52.7 (62.8)44.5 (52.5)61.6 (71.1)51.4 (57.3)52.0 (60.6)< 0.001Start of Radiotherapy152.9 (90.5)128.0 (83.7)165.4 (99.7)144.2 (90.0)151.0 (93.2)< 0.001Start of Chemotherapy76.0 (53.1)68.8 (47.8)77.7 (56.1)72.9 (52.6)78.8 (50.2)< 0.001Start of HT160.7 (103.7)144.3 (101.4)171.2 (117.8)160.4 (106.9)171.5 (115.2)< 0.001

Citation Format: Algan O, Campbell JE, Algan SM. Stage-at-presentation and time-to-treatment for American Indian patients diagnosed with breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P5-08-10.

A Review of Pharmacovigilance

Pharmacovigilance supports safe and appropriate use of drugs. Spontaneous reporting of adverse drug reactions (ADRs) is an essential component of pharmacovigilance. However, there is significant underreporting of ADRs. Adverse drug reactions have become a major problem in developing countries. Knowledge of pharmacovigilance could form the basis for interventions aimed at improving reporting rates and decreasing ADRs.

Abstract P2-01-06: How much agreement can we expect on BI-RADS mammographic findings? Observer agreement among 10 expert mammographers

Purpose: To determine the agreement between expert readers on mammographic findings and calcification patterns.

Materials and Methods: Ten academic radiologists from 5 centers reviewed 250 de-identified mammographic cases without prior exams which were previously assessed as BI-RADS 4 or 5 with subsequent pathologic diagnosis by percutaneous or surgical biopsy. For benign cases diagnosed by percutaneous biopsy, 1 year of benign or negative imaging follow-up was required. Using standardized forms, each radiologist assessed the presence of any suspicious mammographic findings (microcalcifications, asymmetry (1-vew), focal asymmetry (2-view), architectural distortion), and the morphology (none, round/punctate, amorphous, coarse heterogeneous, fine pleomorphic, fine linear branching) and distribution (none, diffuse, regional, grouped, linear, segmental) of any identified microcalcifications. Agreement between radiologists for presence/absence of findings, morphology, and distribution of calcifications was determined by calculating the Kappa (k) coefficient with 95% confidence interval (95% CI). The kappa coefficient proposed strength of agreement is ≤0 = poor, .01-.20 = slight, .21-.40 = fair, .41-.60 = moderate, .61-.80 = substantial, and .81-1 = almost perfect, as established by Landis and Koch.1

Results: Of the 250 lesions, 156 (62%) were benign and 94 (38%) malignant. Agreement among the 10 expert readers was strongest for recognizing the presence/absence of calcifications (k = 0.82, 95% CI: 0.80-84), “almost perfect”). There was substantial agreement among the readers for the identification of a mass (k = 0.67, 95% CI: 0.66-69), whereas agreement was fair for the presence of a focal (2-view) asymmetry (k = 0.21, 95% CI: 0.1900.23) or architectural distortion (k = 0.28, 95%CI: 0.26-0.30). Agreement for asymmetries (1-view) was slight (k = 0.09, 95%CI: 0.08-0.11). Among the 6 categories of microcalcification distribution and morphology, reader agreement was moderate (distribution k = 0.60, 95%CI:0.59-0.61; morphology k = 0.51, 95%CI: 0.50-0.52).

Conclusion: When asked to characterize suspicious mammographic findings, this sampling of 10 expert academic breast imagers across 5 centers revealed varying strength of agreement for different findings, ranging from slight to almost perfect. Strongest agreement (“almost perfect”) was found for identifying the presence or absence of microcalcifications, although agreement drops to moderate when readers are asked to specify microcalcification morphology and distribution.

1 Landis JR, Koch GG. The measurement of observer agreement for categorical data. Biometrics.1977;33:159-174.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P2-01-06.

Historical U.S. cropland areas and the potential for bioenergy production on abandoned croplands

Agriculture is historically a dominant form of global environmental degradation, and the potential for increased future degradation may be driven by growing demand for food and biofuels. While these impacts have been explored using global gridded maps of croplands, such maps are based on relatively coarse spatial data. Here, we apply high-resolution cropland inventories for the conterminous U.S. with a land-use model to develop historical gridded cropland areas for the years 1850-2000 and year 2000 abandoned cropland maps. While the historical cropland maps are consistent with generally accepted land-use trends, our U.S. abandoned cropland estimates of 68 Mha are as much as 70% larger than previous gridded estimates due to a reduction in aggregation effects. Renewed cultivation on the subset of abandoned croplands that have not become forests or urban lands represents one approach to mitigating the future expansion of agriculture. Potential bioenergy production from these abandoned lands using a wide range of biomass yields and conversion efficiencies has an upper-limit of 5-30% of the current U.S. primary energy demand or 4-30% of the current U.S. liquid fuel demand.

Biofuels that cause land-use change may have much larger non-GHG air quality emissions than fossil fuels

Although biofuels present an opportunity for renewable energy production, significant land-use change resulting from biofuels may contribute to negative environmental, economic, and social impacts. Here we examined non-GHG air pollution impacts from both indirect and direct land-use change caused by the anticipated expansion of Brazilian biofuels production. We synthesized information on fuel loading, combustion completeness, and emission factors, and developed a spatially explicit approach with uncertainty and sensitivity analyses to estimate air pollution emissions. The land-use change emissions, ranging from 6.7 to 26.4 Tg PM(2.5), were dominated by deforestation burning practices associated with indirect land-use change. We also found Brazilian sugar cane ethanol and soybean biodiesel including direct and indirect land-use change effects have much larger life-cycle emissions than conventional fossil fuels for six regulated air pollutants. The emissions magnitude and uncertainty decrease with longer life-cycle integration periods. Results are conditional to the single LUC scenario employed here. After LUC uncertainty, the largest source of uncertainty in LUC emissions stems from the combustion completeness during deforestation. While current biofuels cropland burning policies in Brazil seek to reduce life-cycle emissions, these policies do not address the large emissions caused by indirect land-use change.

Land-use and alternative bioenergy pathways for waste biomass

Rapid escalation in biofuels consumption may lead to a trade regime that favors exports of food-based biofuels from tropical developing countries to developed countries. There is growing interest in mitigating the land-use impacts of these potential biofuels exports by converting biorefinery waste streams into cellulosic ethanol, potentially reducing the amount of land needed to meet production goals. This increased land-use efficiency for ethanol production may lower the land-use greenhouse gas emissions of ethanol but would come at the expense of converting the wastes into bioelectricity which may offset fossil fuel-based electricity and could provide a vital source of domestic electricity in developing countries. Here we compare these alternative uses of wastes with respect to environmental and energy security outcomes considering a range of electricity production efficiencies, ethanol yields, land-use scenarios, and energy offset assumptions. For a given amount of waste biomass, we found that using bioelectricity production to offset natural gas achieves 58% greater greenhouse gas reductions than using cellulosic ethanol to offset gasoline but similar emissions when cellulosic ethanol is used to offset the need for more sugar cane ethanol. If bioelectricity offsets low-carbon energy sources such as nuclear power then the liquid fuels pathway is preferred. Exports of cellulosic ethanol may have a small impact on the energy security of importing nations while bioelectricity production may have relatively large impacts on the energy security in developing countries.

Efficacy of embolic protection devices in renal artery stenting

The efficacy of embolic protection devices (EPDs) have been studied extensively in coronary saphenous vein grafts and extra cranial cerebrovascular disease. Recent ex-vivo and in-vivo renal artery stenting studies suggest atheroembolism is not unique to the coronary and cerebrovascular domain and it seems intuitive, renal EPDs may be beneficial. In an attempt to better understand the current objective evidence regarding renal protection efficacy we systematically reviewed the contemporary literature and summarize the findings herein. There is increasing observational data suggesting the use of embolic protection devices decrease the risk of continued decline in renal function after renal artery stenting. There is also prospective randomized data to suggest that the use of adjuvant IIb/IIIa glycoprotein inhibitor and embolic protection has synergistic benefit, but this is a very small series. However, there are currently no well controlled prospective trials to conclude the added risk and expense of renal protection is countered by proven clinical benefit. Based on the literature compiled in this manuscript we do believe EPDs should be considered in some high-risk patients.

Greater transportation energy and GHG offsets from bioelectricity than ethanol

The quantity of land available to grow biofuel crops without affecting food prices or greenhouse gas (GHG) emissions from land conversion is limited. Therefore, bioenergy should maximize land-use efficiency when addressing transportation and climate change goals. Biomass could power either internal combustion or electric vehicles, but the relative land-use efficiency of these two energy pathways is not well quantified. Here, we show that bioelectricity outperforms ethanol across a range of feedstocks, conversion technologies, and vehicle classes. Bioelectricity produces an average of 81% more transportation kilometers and 108% more emissions offsets per unit area of cropland than does cellulosic ethanol. These results suggest that alternative bioenergy pathways have large differences in how efficiently they use the available land to achieve transportation and climate goals.

Transcatheter therapy for the treatment of atherosclerotic renal artery stenosis

The preemptory challenge in this invited review was to provide a contemporary evidence-based analysis of how renal artery intervention effects renal function and hypertension while also addressing the efficacy in transplanted kidneys. The authors tailored the paper architecture in a way that provides a systematic review of the randomized and observational data relating to the impact of renal stenting in each of these clinical domains. When appropriate the authors include data from their experience with over 1 200 renal stent procedures. This contemporary literature review provides objective insight into the procedural risk and early outcomes following renal intervention based on observational study

RESULTS

However, well-controlled randomized trials and standardization of interventional technique with or without embolic protection is desperately needed.

Age variations in personal agency and self-esteem: the context of physical disability

OBJECTIVES

This study examines how age patterns in health control, self-efficacy, and self-esteem are influenced by age-correlated social status, health, personality, and social integration variables.

METHODS

Ordinary least squares regression documents age patterns in data from a 1985 community sample of 1,549 physically disabled and nondisabled individuals from southwestern Ontario, Canada.

RESULTS

Older respondents report lower health control, self-efficacy, and self-esteem. Less education, more physical impairment, poorer global health, less empathy, and less introspectiveness explain about 43% of age's negative association with health control and more than half of its negative association with self-esteem. In addition, age is associated more negatively with self-efficacy among the disabled. Social status variables conceal the strength of the age-by-disability interaction coefficient, while health accounts for almost an equal amount.

DISCUSSION

The findings describe how age-correlated personal and social factors contribute to, or statistically conceal, older adults' sense of health control, self-efficacy, and self-esteem.

Synthesis and structure-activity relationships of 5-substituted pyridine analogues of 3

In an effort to probe the steric influence of C5 substitution of the pyridine ring on CNS binding affinity, analogues of 1 substituted with a bulky moiety--such as phenyl, substituted phenyl, or heteroaryl-were synthesized and tested in vitro for neuronal nicotinic acetylcholine receptor binding affinity. The substituted analogues exhibited Ki values ranging from 0.055 to 0.69 nM compared to a Ki value of 0.15 nM for compound 1. Assessment of functional activity at subtypes of neuronal nicotinic acetylcholine receptors led to identify several agonists and antagonists.

Structure-activity studies on a novel series of cholinergic channel activators based on a heteroaryl ether framework

Analogs of compound 1 with a variety of azacycles and heteroaryl groups were synthesized. These analogs exhibited Ki values ranging from 0.15 to > 10,000 nM when tested in vitro for cholinergic channel receptor binding activity (displacement of [3H](-) cytisine from whole rat brain synaptic membranes).

Structure-activity studies related to ABT-594, a potent nonopioid analgesic agent: effect of pyridine and azetidine ring substitutions on nicotinic acetylcholine receptor binding affinity and analgesic activity in mice

Analogs of A-98593 (1) and its enantiomer ABT-594 (2) with diverse substituents on the pyridine ring were prepared and tested for affinity to nicotinic acetylcholine receptor binding sites in rat brain and for analgesic activity in the mouse hot plate assay. Numerous types of modifications were consistent with high affinity for [3H]cytisine binding sites. By contrast, only selected modifications resulted in retention of analgesic potency in the same range as 1 and 2. Analogs of 2 with one or two methyl substituents at the 3-position of the azetidine ring also were prepared and found to be substantially less active in both assays.

ABT-594, a novel cholinergic channel modulator, is efficacious in nerve ligation and diabetic neuropathy models of neuropathic pain

A novel cholinergic channel modulator, ABT-594, was tested in two established and distinct models of neuropathic pain; the Chung model (i.e., tight ligation of L5 and L6 spinal nerves) and a diabetic neuropathy model (i.e., streptozotocin-induced diabetes). Tactile allodynia and mechanical hyperalgesia were assessed in the Chung and diabetic neuropathy models, respectively. ABT-594 produced a significant antiallodynic effect following both oral (0.1-1 micromol/kg) and intraperitoneal (i.p.) (0.3 micromol/kg) administration. Equal efficacy was observed following both routes of administration. ABT-594 (0.3 micromol/kg, i.p.) maintained efficacy following repeated dosing (5 days; twice daily) in the Chung model, but the effect of morphine (21 micromol/kg, i.p.) was significantly reduced after repeated dosing. In the diabetic neuropathy model, ABT-594 (0.3 micromol/kg, i.p.) effectively reduced mechanical hyperalgesia. Morphine (21 micromol/kg, i.p.) was not effective in this model. Overall, these results suggest development of ABT-594 may provide a novel pharmacotherapy for the chronic treatment of neuropathic pain.

ABT-594 [(R)-5-(2-azetidinylmethoxy)-2-chloropyridine]: a novel, orally effective analgesic acting via neuronal nicotinic acetylcholine receptors: I. In vitro characterization

The discovery of (+/-)-epibatidine, a naturally occurring neuronal nicotinic acetylcholine receptor (nAChR) agonist with antinociceptive activity 200-fold more potent than that of morphine, has renewed interest in the potential role of nAChRs in pain processing. However, (+/-)-epibatidine has significant side-effect liabilities associated with potent activity at the ganglionic and neuromuscular junction nAChR subtypes which limit its potential as a clinical entity. ABT-594 [(R)-5-(2-azetidinylmethoxy)-2-chloropyridine] is a novel, potent cholinergic nAChR ligand with analgesic properties (see accompanying paper by Bannon et al., 1998b) that shows preferential selectivity for neuronal nAChRs and a consequently improved in vivo side-effect profile compared with (+/-)-epibatidine. ABT-594 is a potent inhibitor of the binding of [3H](-)-cytisine to alpha 4 beta 2 neuronal nAChRs (Ki = 37 pM, rat brain; Ki = 55 pM, transfected human receptor). At the alpha 1 beta 1 delta gamma neuromuscular nAChR labeled by [125I] alpha-bungarotoxin (alpha-Btx), ABT-594 has a Ki value of 10,000 nM resulting in a greater than 180,000-fold selectivity of the compound for the neuronal alpha 4 beta 2 nAChR. In contrast, (+/-)-epibatidine has Ki values of 70 pM and 2.7 nM at the alpha 4 beta 2 and alpha 1 beta 1 delta gamma nAChRs, respectively, giving a selectivity of only 38-fold. The S-enantiomer of ABT-594, A-98593 has activity at the neuronal alpha 4 beta 2 nAChR identical with ABT-594 (Ki = 34-39 pM), which demonstrates a lack of stereospecific binding similar to that reported previously for (+/-)-epibatidine. A similar lack of stereoselectivity is seen at the human alpha 7 receptor. However, A-98593 is 3-fold more potent at the neuromuscular nAChR (Ki = 3420 nM) and the brain alpha-Btx-sensitive nAChR (Ki = 4620 nM) than ABT-594. ABT-594 has weak affinity in binding assays for adrenoreceptor subtypes alpha-1B (Ki = 890 nM), alpha-2B (Ki = 597 nM) and alpha-2C (Ki = 342 nM), and it has negligible affinity (Ki > 1000 nM) for approximately 70 other receptors, enzyme and transporter binding sites. Functionally, ABT-594 is an agonist. At the transfected human alpha 4 beta 2 neuronal nAChR (K177 cells), with increased 86Rb+ efflux as a measure of cation efflux, ABT-594 had an EC50 value of 140 nM with an intrinsic activity (IA) compared with (-)-nicotine of 130%; at the nAChR subtype expressed in IMR-32 cells (sympathetic ganglion-like), an EC50 of 340 nM (IA = 126%); at the F11 dorsal root ganglion cell line (sensory ganglion-like), an EC50 of 1220 nM (IA = 71%); and via direct measurement of ion currents, an EC50 value of 56,000 nM (IA = 83%) at the human alpha 7 homooligimeric nAChR produced in oocytes. A-98593 is 2- to 3-fold more potent and displays approximately 50% greater intrinsic activity than ABT-594 in all four functional assays. In terms of potency, ABT-594 is 8- to 64-fold less active than (+/-)-epibatidine and also has less IA in these functional assays. ABT-594 (30 microM) inhibits the release of calcitonin gene-related peptide from C-fibers terminating in the dorsal horn of the spinal cord, an effect mediated via nAChRs. Pharmacologically, ABT-594 has an in vitro profile distinct from that of the prototypic nicotinic analgesic (+/-)-epibatidine, with the potential for substantially reduced side-effect liability and, as such, represents a potentially novel therapeutic approach to pain management.

Nonmarital births in Oklahoma 1975-1995

This report uses data from the Oklahoma State Department of Health to describe past trends and current patterns of nonmarital births in Oklahoma. Between 1975 and 1995, the percentage of unmarried women delivering a live birth in Oklahoma increased from 12% to 31%. Adult nonmarital births increased faster than teen nonmarital births, but teens had a higher percentage of nonmarital births. White rates increased faster than African-American and Native American rates, but African-Americans had a higher percentage of nonmarital births. Unmarried women who give birth were more likely to be poor and lack education; additionally, they were less likely to receive early prenatal care, more likely to have had low weight births, and more likely to have had an unintended pregnancy. Birth outcomes are poorer among unmarried women, but this may be due to poverty and education rather than marital status alone.

Identification and initial structure-activity relationships of (R)-5-(2-azetidinylmethoxy)-2-chloropyridine (ABT-594), a potent, orally active, non-opiate analgesic agent acting via neuronal nicotinic acetylcholine receptors

New members of a previously reported series of 3-pyridyl ether compounds are disclosed as novel, potent analgesic agents acting through neuronal nicotinic acetylcholine receptors. Both (R)-2-chloro-5-(2-azetidinylmethoxy)pyridine (ABT-594, 5) and its S-enantiomer (4) show potent analgesic activity in the mouse hot-plate assay following either intraperitoneal (i.p.) or oral (p.o.) administration, as well as activity in the mouse abdominal constriction (writhing) assay, a model of persistent pain. Compared to the S-enantiomer and to the prototypical potent nicotinic analgesic agent (+/-)-epibatidine, 5 shows diminished activity in models of peripheral side effects. Structure-activity studies of analogues related to 4 and 5 suggest that the N-unsubstituted azetidine moiety and the 2-chloro substituent on the pyridine ring are important contributors to potent analgesic activity.

Synthesis and structure-activity relationships of pyridine-modified analogs of 3-[2-((S)-pyrrolidinyl)methoxy]pyridine, A-84543, a potent nicotinic acetylcholine receptor agonist

Analogs of 3-[2-((S)-pyrrolidinyl)methoxy]pyridine, (A-84543, 1) with 2-, 4-, 5-, and 6-substituents on the pyridine ring were synthesized. These analogs exhibited Ki values ranging from 0.15 to > 9,000 nM when tested in vitro for neuronal nicotinic acetylcholine receptor binding activity. Assessment of functional activity at subtypes of neuronal nicotinic acetylcholine receptors indicates that pyridine substitution can have a profound effect on efficacy at these subtypes, and several subtype-selective agonists and antagonists have been identified.

ABT-089 [2-methyl-3-(2-(S)-pyrrolidinylmethoxy)pyridine]: I. A potent and selective cholinergic channel modulator with neuroprotective properties

Accumulating preclinical and clinical evidence data suggests that compounds that selectively activate neuronal nicotinic acetylcholine receptor (nAChR) subtypes may have therapeutic utility for the treatment of several neurological disorders. In the present study, the in vitro pharmacological properties of the novel cholinergic channel modulator ABT-089 [2-methyl-3-(2-(S)-pyrrolidinylmethoxy)pyridine], are described. In radioligand binding studies, ABT-089 was shown to display selectivity toward the high-affinity (-)-cytisine binding site present on the alpha4beta2 nAChR subtype (Ki = 16 nM) relative to the [125I]alpha-bungarotoxin binding site present on the alpha7 (Ki > or = 10,000 nM) and alpha1beta1deltagamma (Ki > 1000 nM) nAChR subtypes. In cation flux and channel current studies, ABT-089 displayed a more complex profile than (-)-nicotine having agonist, partial agonist and inhibitory activities depending on the nAChR subtype with which it interacts. ABT-089 differentially stimulated neurotransmitter release. The compound displayed a similar potency and efficacy to (-)-nicotine to facilitate ACh release (ABT-089, EC50 = 3 microM; (-)-nicotine, EC50 = 1 microM), but was markedly less potent and less efficacious than (-)-nicotine to stimulate dopamine release (ABT-089, EC50 = 1.1 microM; (-)-nicotine, EC50 = 0.04 microM). Additionally, ABT-089 was neuroprotective against the excitotoxic insults elicited by exposure to glutamate in both rat cortical cell cultures (EC50 = 10 +/- 3 microM) and differentiated human IMR32 cells (EC50 = 3 +/- 2 microM). The differential full agonist/partial agonist profile of ABT-089, as compared with (-)-nicotine and ABT-418, illustrates the complexity of nAChR activation and the potential to target responses at subclasses of the neuronal and peripheral receptors.

Functional characterization of the novel neuronal nicotinic acetylcholine receptor ligand GTS-21 in vitro and in vivo

(2.4)-Dimethoxybenzylidene anabaseine dihydrochloride (GTS-21), a compound that interacts with rat neuronal nicotinic acetylcholine receptors (nAChRs), was evaluated using human recombinant nAChRs in vitro and various pharmacokinetic and behavioral models in rodents, dogs and monkeys. GTS-21 bound to human alpha 4 beta 2 nAChR (K1-20 nM) 100-fold more potently than to human alpha 7 nAChR, and was 18- and 2-fold less potent than (-)-nicotine at human alpha 4 beta 2 and alpha 7 nAChR, respectively. Functionally. GTS-21 stimulated [5H]dopamine release from rat striatal slices with an EC50 of 10 +/- 2 microM (250-fold less potent and 70% as efficacious as (-)-nicotine), an effect blocked by the nAChR antagonist dihydro-beta-erythroidine. However, GTS-21 did not stimulate human alpha 4 beta 2 nor human ganglionic nAChRs significantly. In vivo, GTS-21 had no adverse effect on dog blood pressure (< or = 2.5 micromol/kg i.v. bolus infusion), in marked contrast with (-)-nicotine, GTS-21 (-62 micromol/kg.s.e.) also did not cross-discriminate significantly with (-)-nicotine in rats and did not reduce temperature or locomotion in mice. Neither was it active in the elevated plus maze anxiety model (0.19-6.2 micromol/kg.IP) in normal mice. However, GTS-21 did improve learning performance of monkeys in the delayed matching-to-sample task (32-130 nmol/kg.i.m.).

Lycaconitine revisited: partial synthesis and neuronal nicotinic acetylcholine receptor affinities

The norditerpenoid alkaloid lycaconitine (2) was synthesized from lycoctonine (3) and its affinity determined for two neuronal nicotinic acetylcholine receptor subtypes. The structure of 2 was confirmed by a combination of spectroscopic methods.

A-85380 [3-(2(S)-azetidinylmethoxy) pyridine]: in vitro pharmacological properties of a novel, high affinity alpha 4 beta 2 nicotinic acetylcholine receptor ligand

The in vitro pharmacological properties of a novel cholinergic channel ligand, A-85380 [3-(2(S)-azetidinylmethoxy)pyridine], were examined using tissue preparations that express different putative nAChR subtypes. In radioligand binding studies, A-85380 is shown to be a potent and selective ligand for the human alpha 4 beta 2 nAChR subtype (Ki = 0.05 + 0.01 nM) relative to the human alpha 7 (Ki = 148 +/- 13 nM) and the muscle alpha 1 beta 1 dg subtype expressed in Torpedo electroplax (Ki = 314 +/- 12 nM). The R-enantiomer of A-85380, A-159470, displays little enantioselectivity towards the alpha 4 beta 2 and alpha 1 beta 1 delta gamma subtypes but does not display 12-fold enantioselectivity towards the alpha 7 subtype (Ki = 1275 +/- 199 nM). (+)- and(-)-Epibatidine display similar potencies at the human human alpha 4 beta 2 (Ki = 0.04 +/- 0.02 nM and 0.07 +/- 0.02 nM, respectively), human alpha 7 (Ki = 16 +/- 2 nM and 22 +/- 3 nM, respectively) and muscle alpha 1 beta 1 delta gamma g (Ki = 2.5 +/- 0.9 nM and 5.7 +/- 1.0 nM, respectively) nAChRs. Functionally, A-85380 is a potent activator of cation efflux through the human alpha 4 beta 2 (EC50 = 0.7 +/- 0.1 microM) and ganglionic (EC50 = 0.8 +/- 0.09 microM) subtypes, effects that are attenuated by pretreatment with mecamylamine (10 microM). Further, A-85380 can activate (EC50 = 8.9 +/- 1.9 microM) currents through channels formed by injection of the human alpha 7 subunit into Xenopus oocytes, effects that are attenuated by pretreatment with the alpha 7 nAChR antagonist, methyllycaconitine (10 nM). In all cases, A-85380 is more potent than (-)-nicotine but less potent than (+/-)-epibatidine. In neurotransmitter release studies, A-85380 stimulates the release of dopamine with an EC 50 value of 0.003 +/- 0.001 microM which is equipotent to (+/-)-epibatidine, and 20-fold more potent than (-)-nicotine (EC50 = 0.04 +/- 0.009 microM). Thus, A-85380 displays a profile of robust activation of a number of nAChR subtypes with substantially less affinity for [125I] alpha-BgT sites than [3H](-)-cytisine sites, suggesting that it may serve as a more selective pharmacologic probe for the alpha 4 beta 2 subtype relative to the alpha 7 and alpha 1 beta 1 delta g nAChRs than (+/-)-epibatidine.

A sensitive technique for the detection of the alpha 7 neuronal nicotinic acetylcholine receptor antagonist, methyllycaconitine, in rat plasma and brain

Methyllycaconitine (MLA) is the most potent and selective antagonist of the alpha-bungarotoxin sensitive neuronal nicotinic acetylcholine receptor (nAChR). In the present study, an accurate and reproducible technique for the extraction and analysis of MLA from rat plasma and brain is described. This study further sought to determine whether pharmacologically relevant concentrations of MLA could be achieved in brain following peripheral administration. The detection limits for MLA were 0.5 ng/ml for plasma samples and 1.0 ng/g for brain samples. The pharmacokinetic properties of MLA in rat are characterized by a short elimination half-life (19 min) following intravenous (i.v.) administration and poor bioavailability following oral (p.o.) administration. Remarkably, the elimination half-life is significantly longer following p.o. administration (408 min). To assess the extent to which MLA can penetrate into brain, brain and plasma levels of MLA were determined at different time points following intraperitoneal (i.p.) administration of a dose of MLA that produced no observable side effects. Maximal plasma and brain levels were 694 +/- 106 ng/ml and 32 +/- 3 ng/g, respectively. These concentrations are within a range previously reported to selectively block alpha 7 nAChR mediated responses in vitro. Peripherally administered MLA may therefore be a useful tool to further probe the central nervous system functions of the alpha 7 nAChR subunit in vivo.

Stable expression and pharmacological properties of the human alpha 7 nicotinic acetylcholine receptor

The alpha 7 neuronal nicotinic acetylcholine receptor subtype forms a Ca(2+)-permeable homooligomeric ion channel sensitive to alpha-bungarotoxin in Xenopus oocytes. In this study, we have stably and functionally expressed the human alpha 7 cDNA in a mammalian cell line, HEK-293 and examined its pharmacologic properties. [125I] alpha-Bungarotoxin bound to transfected cells with a Kd value of 0.7 nM and a Bmax value of 973 pmoL/mg protein. No specific binding was detected in untransfected cells. Specific binding could be displaced by unlabeled alpha-bungarotoxin (Ki = 0.5 nM) and an excellent correlation was observed between binding affinities of a series of nicotinic cholinergic ligands in transfected cells and those in the human neuroblastoma IMR-32 cell line. Additionally, cell surface expression of alpha 7 receptors was detected by fluorescein isothiocyanate-conjugated alpha-bungarotoxin in transfected cells. Whole cell currents sensitive to blockade by alpha-bungarotoxin, and with fast kinetics of activation and inactivation, were recorded from transfected cells upon rapid application of (-)-nicotine or acetylcholine with EC50 values of 49 microM and 155 microM respectively. We conclude that the human alpha 7 subunit when expressed alone can form functional ion channels and that the stably transfected HEK-293 cell line serves as a unique system for studying human alpha 7 nicotinic receptor function and regulation, and for examining ligand interactions.

Characterization of [3H]ABT-418: a novel cholinergic channel ligand

ABT-418 [(S)-3-methyl-5-(1-methyl-2-pyrrolidinyl)isoxazole] is a potent and selective agonist at neuronal nicotinic acetylcholine receptors (nAChRs) with cognitive enhancing and anxiolytic activities. [3H]ABT-418 was found to bind with high affinity (KD = 2.85 +/- 0.14 nM) to membranes prepared from rat brain. Binding of [3H]ABT-418 was characterized by rapid association (T1/2 = 1.4 +/- 0.3 min) and dissociation (T1/2 = 2.9 +/- 0.4 min) half-times. The pharmacology of [3H]ABT-418 binding was consistent with an interaction with the putative alpha 4 beta 2 nAChR subtype. The nAChR agonists, (-)-nicotine, (-)-cytisine and (+/-)-epibatidine, displayed a high affinity (Ki = 0.8 +/- 0.1, 0.2 +/- 0.1 and 0.05 +/- 0.01 nM, respectively) for [3H]ABT-418 binding sites, whereas among nAChR antagonists examined, only dihydro-beta-erythroidine competed with high affinity (Ki = 32 +/- 1.5 nM). Although autoradiography studies indicate that the binding distribution of [3H]ABT-418 and (-)-[3H]cytisine are largely identical, there are some brain regions including the striatum, olivary pretectal nucleus and the superior colliculus, in which [3H]ABT-418 demonstrates significantly (P < .05) less binding. The data in the present study demonstrate that [3H]ABT-418 binds with high affinity to a population of binding sites in the rat brain that have the pharmacological characteristics of neuronal nAChRs. [3H]ABT-418 may, therefore, serve as a useful radioligand to further probe the observed differences in pharmacological properties between ABT-418 and other nicotinic agonists in vivo.

Blood quantum and ethnic intermarriage in the Boas data set

The data collected by Boas is biased toward employees of Indian agencies and school populations. The data show that intermarried Amerindians in the last century tended to marry back into the Amerindian population rather than into the general population, as in this century. Distributions of blood quantum within tribes show the intensity and duration of contact with the dominant society and other tribes. Amerindians who married into other tribes tended to choose spouses from contiguous tribes, but over one-fourth of spouses represented different language families. General hypotheses should be tested in the Boas data only with great caution and after correcting for historical factors if possible.

Localization and characterization of a parotid Ca(2+)-dependent ecto-ATPase

Parotid acini were isolated and tested to further establish the presence of ecto-ATPase in the intact cells. Inhibitors were used to determine if the inhibitor profile of the ATPase was similar to that of a Ca(2+)-ATPase from parotid membranes identified previously as an ecto-ATPase. The Ca(2+)-ATPase of intact cells was insensitive to oligomycin (10 micrograms/ml), N-ethylmaleimide (NEM) (0.1 mM), ruthenium red (0.1 mM), sodium azide (1 mM), and was inhibited approximately 22% by sodium orthovanadate (Na3VO4) (1 mM). This profile was similar to the Ca(2+)-ATPase of intact cells. Trifluoperazine (TFP) (0.1 mM) inhibited the enzyme in intact cells by approximately 32%. The nucleotide substrate specificity of the enzyme also reflected very closely the pattern seen in isolated membranes.

A comparison of efficacy and tolerance of the short acting sedatives midazolam and zopiclone

AIMS

To compare the efficacy and tolerance of midazolam, 15 mg and zopiclone 7.5 mg once daily for seven days in a prospective, double blind trial of 88 patients, aged 18 or over, with sleep disorders in general practice.

METHODS

Efficacy was evaluated using the Leeds sleep evaluation questionnaire (LSEQ). Adverse reactions were recorded as volunteered.

RESULTS

fifty-one patients completed all aspects of the trial without violation of the protocol. Patients taking zopiclone improved in all aspects of the Leeds questionnaire (p < 0.01). Patients taking midazolam improved in six out of 10 items (p < 0.01). Rebound insomnia was evident in the zopiclone group in five out of 10 items of the LSEQ. Rebound was not evident in the midazolam group. There were no significant differences between midazolam 15 mg, and zopiclone 7.5 mg, in comparison between groups. Thirty-eight patients suffered 49 adverse drug reactions and there were no differences between the groups.

CONCLUSIONS

Zopiclone 7.5 mg daily improved more items on the LSEQ than midazolam 15 mg daily but was associated with significant rebound insomnia. Adverse reactions were frequent with both drugs.

Performance assessment of radioactive waste repositories

The current plans for permanent disposal of radioactive waste call for its emplacement in deep underground repositories mined from geologically stable rock formations. The U.S. Nuclear Regulatory Commission and U.S. Environmental Protection Agency have established regulations setting repository performance standards for periods of up to 10,000 years after disposal. Compliance with these regulations will be based on a performance assessment that includes (i) identification and evaluation of the likelihood of all significant processes and events that could affect a repository, (ii) examination of the effects of these processes and events on the performance of a repository, and (iii) estimation of the releases of radionuclides, including the associated uncertainties, caused by these processes and events. These estimates are incorporated into a probability distribution function showing the likelihood of exceeding radionuclide release limits specified by regulations.

The management of children with spinal dysraphism

Improvements in technology have dramatically increased the survival of children with spinal dysraphism. Because this complex condition affects multiple organ systems as well as the psychosocial functioning of the child and family, these children require care from a host of specialists in order to achieve optimum functioning. This article reviews the pathophysiology and discusses the current management of the medical and psychosocial effects of spinal dysraphism. It also briefly discusses strategies for intervention, long-term outcomes, and some controversies regarding care and screening.

Basic trauma life support

The impact of traumatic injuries on modern society in terms of morbidity, mortality, and economic cost is enormous. Studies have shown that both advanced life support skills and rapid stabilization and transport of the trauma victim have a beneficial effect on the patient's ultimate outcome. The Basic Trauma Life Support (BTLS) course was designed to provide pre-hospital care providers with the skills necessary to provide a thorough assessment, initial resuscitation, and rapid transportation of the trauma victim. Early studies suggest that the material is easily learned by prehospital care providers and that the on-scene time for trauma cases is reduced following training in BTLS. More widespread training in BTLS may have a significant effect on the mortality and morbidity associated with traumatic injuries.

A role for nurse psychotherapists: primary prevention counseling for general hospital staffs

Providing a counseling and consultation service to general hospital employees through contractual arrangements is beneficial, and is an appropriate function for nurse therapists. Employees willingly use the service, and as stresses increase in the workplace the service can have a favorable impact on both personnel functioning and retention, as well as on the delivery of patient services.

Urinary tract trauma

From a practical point of view, a woman who has blunt injury to the pelvic area with hematuria from the lower urinary tract, has a contused or ruptured bladder. In a man, such a situation calls for retrograde urethrography to determine if the injury is in the urethra or the bladder because the two organs are investigated differently. In both sexes, such injuries are usually associated with pelvic fractures. Massive bladder displacement and severe hemorrhage should alert one to the need for pelvic angiography to find and embolize the bleeding site within the first 24 hours after injury. For blunt trauma to the upper urinary tract an intravenous urogram with tomography is still the main examination. However, a normal intravenous urogram does not exclude serious injury. Therefore, if signs or symptoms persist, a computerized tomographic (CT) examination should be performed if available. Otherwise, a radionuclide study is advisable. Non-excretion on intravenous urography with tomography calls for selective renal arteriography to delineate the etiology. There can be serious renal trauma in the absence of hematuria, which may occur with renal pedicle injury or avulsion of the ureter. Minor forniceal ruptures may occasionally mask severe posterior renal lacerations.

Mammographic patterns and bias in breast cancer detection

Wolfe's finding that some mammographic patterns (P2 and DY) are associated with an increased risk of breast cancer has been challenged by some authors who suggest that this is due to denser patterns concealing cancers present on the first examination: these cancers, it is argued, are diagnosed in later years, creating the spurious impression of increased cancer incidence. The authors examined this hypothesis in a series of patients with breast cancer but failed to find any evidence that the diagnosis was subject to systematic delay in patients with the P2 or DY pattern. Moreover, studies of a hypothetical model showed that bias in the detection of breast cancer was unlikely to account for more than a small increase in apparent cancer incidence. Thus it appears unlikely that such a bias is responsible for the risk of breast cancer observed in patients with these mammographic patterns.

Bias and the association of mammographic parenchymal patterns with breast cancer

We have carried out a case-control study to evaluate the association between Wolfe's mammographic patterns and the risk of breast cancer, and to examine the influence of control selection and the radiologist who read the films upon the results obtained. Mammograms of the non-cancerous breast of 183 women with unilateral breast cancer were compared with mammograms from two age-matched control groups: a group of asymptomatic women attending a screening centre, and a group of symptomatic women referred for the diagnostic evaluation of suspected breast disease. Films were arranged in random sequence and independently classified by 3 radiologists. A strong and statistically significant association was found between mammographic dysplasia and breast cancer when controls from the screening centre were compared to cases, but not when cases were compared to women referred for the diagnostic evaluation of breast disease. This result appears to arise in part because of an association between symptoms of benign breast disease and mammographic dysplasia, and suggests that some previous negative studies of the association of mammographic patterns with breast cancer may have arisen from the inclusion of symptomatic subjects as controls.

Mammographic signs as risk factors for breast cancer

We have carried out a case-control study to examine the relationship between mammographic signs and breast cancer. The mammographic signs assessed were prominent ducts and dysplasia. The cases were a group of 183 women with histologically verified unilateral breast cancer. The controls were a group of women attending a screening centre. Cases and controls were individually age-matched. Mammograms from the non-cancerous breast of the cases were randomly assembled with those of the controls and classified by 3 radiologists without knowledge of which films were from cases and which from controls. Mammographic dysplasia was found to be strongly associated with breast cancer, particularly in women aged less than 50. Prominent ducts were only weakly associated with breast cancer. Multivariate analysis showed that the association between dysplasia and breast cancer could not be explained on the basis of other risk factors for breast cancer, and that classification of dysplasia discriminated more strongly between cases and controls than did classification of Wolfe's mammographic patterns. These results show that mammograms contain information about risk of breast cancer. Mammographic dysplasia is strongly associated with breast cancer, is present in a substantial proportion of patients with the disease, and may offer opportunities for prevention.