bluuebunny/crossref_metadata_2025 huggingface dataset:
Targeting Suboptimal Prescribing in the Elderly: A Review of the Impact of Pharmacy Services
Authors: Castelino Ronald L , Bajorek Beata V , Chen Timothy F
Published: May 2009

Objective

To review the currently available literature on the impact of interventions by pharmacists on suboptimal prescribing in the elderly.

Data Sources

MEDLINE, EMBASE, and International Pharmaceutical Abstracts databases were searched for studies published between January 1992 and December 2008. Key words included medication review, drug regimen review, pharmaceutical services, pharmaceutical care, pharmacists, medications, appropriateness, suboptimal, underuse, aged, elderly, randomized controlled trial, inappropriate, prescribing, and intervention.

Study Selection And Data Extraction

To be included in the review, studies must have been conducted in patients 65 years or older, published in English, randomized and controlled, and must have included an intervention delivered by a pharmacist or had a pharmacist as a member of the intervention team. From each relevant study, the following data were extracted: study duration, country, number of patients, year of publication, objective, type and impact of the intervention, method used to assess suboptimal prescribing, and data concerning the quality of the study.

Data Synthesis

A total of 38 articles were identified, of which 12 matched our inclusion criteria. Seven articles included interventions initiated by pharmacists, and the remaining 5 described interventions in which the pharmacist was a part of the multidisciplinary team. A broad range of tools was used to measure prescribing appropriateness; we found that a consensus on the best approach has not been reached. Most of the studies involving pharmacists showed significant improvement in suboptimal prescribing at one or more time points. However, most of these interventions were directed toward reducing the overuse or misuse of medications.

Conclusions

Pharmacy services to reduce suboptimal prescribing have shown promising and noteworthy improvements. More research is needed to address the underutilization of medications in the elderly and healthcare impact of reducing suboptimal prescribing.
Assessment of Older Adults' Knowledge of and Preferences for Medication Management Tools and Support Systems
Authors: Lakey Susan L , Gray Shelly L , Borson Soo
Published: May 2009

Background

A variety of strategies are available to assist older adults who have difficulties managing medications. Little is known about older adults' knowledge of or willingness to use these strategies.

Objective

To assess older adults' current use of, knowledge of, and preferences for medication management tools and supports.

Methods

A cross-sectional study was conducted at a continuing care retirement community. All 152 independent-living residents were approached for participation. We developed a 6-page survey to gather information about knowledge of and preferences for medication management tools (eg, medi-sets, bubble-packs) and supports (eg, family, caregivers, regimen simplification). Information on demographic variables, medication management capacity, cognition, self-reported difficulty taking medications, and medication use were collected along with survey answers during an in-home interview. χ2 and t-tests were used to compare knowledge and preferences by complexity and organizer use.

Results

Our sample consisted of 109 participants ranging in age from 73 to 98 years (average 85.9). Most of the subjects were well educated (average 15.5 y of education), 98% were white, and 80% were female. The majority (82%) were using a medication tool, mainly simple, self-filled medi-sets (62%) and easy-open vials (55%). Knowledge about, use of, and preferences for other devices, including pharmacist-filled tools and programmable devices, were low. Participants who used medication organizers rated self-filled medi-sets higher than did non-users (4.7 vs 1.6; p < 0.01). Only 18% of participants had asked a provider to simplify their medications, while 40% did not realize that they could do so. Of those who did ask a provider, 80% asked a physician.

Conclusions

Educational strategies are needed to increase awareness of the pharmacist's role in facilitating medication management and the option of simplifying complex regimens. It is within the scope of pharmacy to provide this type of medication education.
Protein Extraction of Formalin-fixed, Paraffin-embedded Tissue Enables Robust Proteomic Profiles by Mass Spectrometry
Authors: Scicchitano Marshall S. , Dalmas Deidre A. , Boyce Rogely W. , Thomas Heath C. , Frazier Kendall S.
Published: May 2009

Global mass spectrometry (MS) profiling and spectral count quantitation are used to identify unique or differentially expressed proteins and can help identify potential biomarkers. MS has rarely been conducted in retrospective studies, because historically, available samples for protein analyses were limited to formalin-fixed, paraffin-embedded (FFPE) archived tissue specimens. Reliable methods for obtaining proteomic profiles from FFPE samples are needed. Proteomic analysis of these samples has been confounded by formalin-induced protein cross-linking. The performance of extracted proteins in a liquid chromatography tandem MS format from FFPE samples and extracts from whole and laser capture microdissected (LCM) FFPE and frozen/optimal cutting temperature (OCT)- embedded matched control rat liver samples were compared. Extracts from FFPE and frozen/OCT-embedded livers from atorvastatin-treated rats were further compared to assess the performance of FFPE samples in identifying atorvastatin-regulated proteins. Comparable molecular mass representation was found in extracts from FFPE and OCT-frozen tissue sections, whereas protein yields were slightly less for the FFPE sample. The numbers of shared proteins identified indicated that robust proteomic representation from FFPE tissue and LCM did not negatively affect the number of identified proteins from either OCT-frozen or FFPE samples. Subcellular representation in FFPE samples was similar to OCT-frozen, with predominantly cytoplasmic proteins identified. Biologically relevant protein changes were detected in atorvastatin-treated FFPE liver samples, and selected atorvastatin-related proteins identified by MS were confirmed by Western blot analysis. These findings demonstrate that formalin fixation, paraffin processing, and LCM do not negatively impact protein quality and quantity as determined by MS and that FFPE samples are amenable to global proteomic analysis.
Immunoreactivity of Glutamate in Mouse Retina Inner Segment of Photoreceptors With In Vivo Cryotechnique
Authors: Terada Nobuo , Ohno Nobuhiko , Saitoh Sei , Saitoh Yurika , Ohno Shinichi
Published: May 2009

The purpose of this study was to clarify a previously controversial issue concerning glutamate (Glu) immunoreactivity (IR) in the inner segment (IS) of photoreceptors by using in vivo cryotechnique (IVCT) followed by freeze substitution (FS), which enabled us to analyze the cells and tissues reflecting living states. Eyeballs from anesthetized mice were directly frozen using IVCT. The frozen tissues were processed for FS fixation in acetone containing chemical fixatives, and embedded in paraffin. Deparaffinized sections were immunostained with an anti-Glu antibody. The strongest Glu-IR was obtained in the specimens prepared by FS with paraformaldehyde or a low concentration of glutaraldehyde, whereas no Glu-IR was obtained without the chemical fixatives. The Glu was immunolocalized in the IS, outer and inner plexiform and ganglion cell layers. Thus, the immunolocalization of Glu in the IS was clearly demonstrated using IVCT.
The Mammalian Target of Rapamycin Signaling Pathway Mediates Epileptogenesis in a Model of Temporal Lobe Epilepsy
Authors: Zeng Ling-Hui , Rensing Nicholas R. , Wong Michael
Published: May 2009

Understanding molecular mechanisms mediating epileptogenesis is critical for developing more effective therapies for epilepsy. We recently found that the mammalian target of rapamycin (mTOR) signaling pathway is involved in epileptogenesis, and mTOR inhibitors prevent epilepsy in a mouse model of tuberous sclerosis complex. Here, we investigated the potential role of mTOR in a rat model of temporal lobe epilepsy initiated by status epilepticus. Acute kainate-induced seizures resulted in biphasic activation of the mTOR pathway, as evident by an increase in phospho-S6 (P-S6) expression. An initial rise in P-S6 expression started ∼1 h after seizure onset, peaked at 3–6 h, and returned to baseline by 24 h in both hippocampus and neocortex, reflecting widespread stimulation of mTOR signaling by acute seizure activity. After resolution of status epilepticus, a second increase in P-S6 was observed in hippocampus only, which started at 3 d, peaked 5–10 d, and persisted for several weeks after kainate injection, correlating with the development of chronic epileptogenesis within hippocampus. The mTOR inhibitor rapamycin, administered before kainate, blocked both the acute and chronic phases of seizure-induced mTOR activation and decreased kainate-induced neuronal cell death, neurogenesis, mossy fiber sprouting, and the development of spontaneous epilepsy. Late rapamycin treatment, after termination of status epilepticus, blocked the chronic phase of mTOR activation and reduced mossy fiber sprouting and epilepsy but not neurogenesis or neuronal death. These findings indicate that mTOR signaling mediates mechanisms of epileptogenesis in the kainate rat model and that mTOR inhibitors have potential antiepileptogenic effects in this model.
Transcriptional and Electrophysiological Maturation of Neocortical Fast-Spiking GABAergic Interneurons
Authors: Okaty Benjamin W. , Miller Mark N. , Sugino Ken , Hempel Chris M. , Nelson Sacha B.
Published: May 2009

Fast-spiking (FS) interneurons are important elements of neocortical circuitry that constitute the primary source of synaptic inhibition in adult cortex and impart temporal organization on ongoing cortical activity. The highly specialized intrinsic membrane and firing properties that allow cortical FS interneurons to perform these functions are attributable to equally specialized gene expression, which is ultimately coordinated by cell-type-specific transcriptional regulation. Although embryonic transcriptional events govern the initial steps of cell-type specification in most cortical interneurons, including FS cells, the electrophysiological properties that distinguish adult cortical cell types emerge relatively late in postnatal development, and the transcriptional events that drive this maturational process are not known. To address this, we used mouse whole-genome microarrays and whole-cell patch clamp to characterize the transcriptional and electrophysiological maturation of cortical FS interneurons between postnatal day 7 (P7) and P40. We found that the intrinsic and synaptic physiology of FS cells undergoes profound regulation over the first 4 postnatal weeks and that these changes are correlated with primarily monotonic but bidirectional transcriptional regulation of thousands of genes belonging to multiple functional classes. Using our microarray screen as a guide, we discovered that upregulation of two-pore K+leak channels between P10 and P25 contributes to one of the major differences between the intrinsic membrane properties of immature and adult FS cells and found a number of other candidate genes that likely confer cell-type specificity on mature FS cells.
Compensatory Enhancement of Intrinsic Spiking upon NKCC1 Disruption in Neonatal Hippocampus
Authors: Sipilä Sampsa T. , Huttu Kristiina , Yamada Junko , Afzalov Ramil , Voipio Juha , Blaesse Peter , Kaila Kai
Published: May 2009

Depolarizing and excitatory GABA actions are thought to be important in cortical development. We show here that GABA has no excitatory action on CA3 pyramidal neurons in hippocampal slices from neonatalNKCC1−/−mice that lack the Na–K–2Cl cotransporter isoform 1. Strikingly,NKCC1−/−slices generated endogenous network events similar to giant depolarizing potentials (GDPs), but, unlike in wild-type slices, the GDPs were not facilitated by the GABAAagonist isoguvacine or blocked by the NKCC1 inhibitor bumetanide. The developmental upregulation of the K–Cl cotransporter 2 (KCC2) was unperturbed, whereas the pharmacologically isolated glutamatergic network activity and the intrinsic excitability of CA3 pyramidal neurons were enhanced in theNKCC1−/−hippocampus. Hence, developmental expression of KCC2, unsilencing of AMPA-type synapses, and early network events can take place in the absence of excitatory GABAergic signaling in the neonatal hippocampus. Furthermore, we show that genetic as well as pharmacologically induced loss of NKCC1-dependent excitatory actions of GABA results in a dramatic compensatory increase in the intrinsic excitability of glutamatergic neurons, pointing to powerful homeostatic regulation of neuronal activity in the developing hippocampal circuitry.
Visual Field Map Clusters in Macaque Extrastriate Visual Cortex
Authors: Kolster Hauke , Mandeville Joseph B. , Arsenault John T. , Ekstrom Leeland B. , Wald Lawrence L. , Vanduffel Wim
Published: May 2009

The macaque visual cortex contains >30 different functional visual areas, yet surprisingly little is known about the underlying organizational principles that structure its components into a complete “visual” unit. A recent model of visual cortical organization in humans suggests that visual field maps are organized as clusters. Clusters minimize axonal connections between individual field maps that represent common visual percepts, with different clusters thought to carry out different functions. Experimental support for this hypothesis, however, is lacking in macaques, leaving open the question of whether it is unique to humans or a more general model for primate vision. Here we show, using high-resolution blood oxygen level-dependent functional magnetic resonance imaging data in the awake monkey at 7 T, that the middle temporal area (area MT/V5) and its neighbors are organized as a cluster with a common foveal representation and a circular eccentricity map. This novel view on the functional topography of area MT/V5 and satellites indicates that field map clusters are evolutionarily preserved and may be a fundamental organizational principle of the Old World primate visual cortex.
Functional Role of a Specialized Class of Spinal Commissural Inhibitory Neurons during Fast Escapes in Zebrafish
Authors: Satou Chie , Kimura Yukiko , Kohashi Tsunehiko , Horikawa Kazuki , Takeda Hiroyuki , Oda Yoichi , Higashijima Shin-ichi
Published: May 2009

In teleost fish, the Mauthner (M) cell, a large reticulospinal neuron in the brainstem, triggers escape behavior. Spinal commissural inhibitory interneurons that are electrotonically excited by the M-axon have been identified, but the behavioral roles of these neurons have not yet been addressed. Here, we studied these neurons, named CoLo (commissural local), in larval zebrafish using an enhancer-trap line in which the entire population of CoLos was visualized by green fluorescent protein. CoLos were present at one cell per hemi-segment. Electrophysiological recordings showed that an M-spike evoked a spike in CoLos via electrotonic transmission and that CoLos made monosynaptic inhibitory connections onto contralateral primary motoneurons, consistent with the results in adult goldfish. We further showed that CoLos were active only during escapes. We examined the behavioral roles of CoLos by investigating escape behaviors in CoLo-ablated larvae. The results showed that the escape behaviors evoked by sound/vibration stimuli were often impaired with a reduced initial bend of the body, indicating that CoLos play important roles in initiating escapes. We obtained several lines of evidence that strongly suggested that the impaired escapes occurred during bilateral activation of the M-cells: in normal larvae, CoLo-mediated inhibitory circuits enable animals to perform escapes even in these occasions by silencing the output of the slightly delayed firing of the second M-cell. This study illustrates (1) a clear example of the behavioral role of a specialized class of interneurons and (2) the capacity of the spinal circuits to filter descending commands and thereby produce the appropriate behavior.
Laminar Fate and Phenotype Specification of Cerebellar GABAergic Interneurons
Authors: Leto Ketty , Bartolini Alice , Yanagawa Yukio , Obata Kunihiko , Magrassi Lorenzo , Schilling Karl , Rossi Ferdinando
Published: May 2009

In most CNS regions, the variety of inhibitory interneurons originates from separate pools of progenitors residing in discrete germinal domains, where they become committed to specific phenotypes and positions during their last mitosis. We show here that GABAergic interneurons of the rodent cerebellum are generated through a different mechanism. Progenitors for these interneurons delaminate from the ventricular neuroepithelium of the embryonic cerebellar primordium and continue to proliferate in the prospective white matter during late embryonic and postnatal development. Young postmitotic interneurons do not migrate immediately to their final destination, but remain in the prospective white matter for several days. The different interneuron categories are produced according to a continuous inside-out positional sequence, and cell identity and laminar placement in the cerebellar cortex are temporally related to birth date. However, terminal commitment does not occur while precursors are still proliferating, and postmitotic cells heterochronically transplanted to developing cerebella consistently adopt host-specific phenotypes and positions. However, solid grafts of prospective white matter implanted into the adult cerebellum, when interneuron genesis has ceased, produce interneuron types characteristic of the donor age. Therefore, specification of cerebellar GABAergic interneurons occurs through a hitherto unknown process, in which postmitotic neurons maintain broad developmental potentialities and their phenotypic choices are dictated by instructive cues provided by the microenvironment of the prospective white matter. Whereas in most CNS regions the repertoire of inhibitory interneurons is produced by recruiting precursors from different origins, in the cerebellum it is achieved by creating phenotypic diversity from a single source.
Role of NeuroepithelialSonic hedgehogin Hypothalamic Patterning
Authors: Szabó Nora-Emöke , Zhao Tianyu , Çankaya Murat , Theil Thomas , Zhou Xunlei , Alvarez-Bolado Gonzalo
Published: May 2009

The hypothalamus is a region of the diencephalon with particularly complex patterning.Sonic hedgehog(Shh), encoding a protein with key developmental roles, shows a peculiar and dynamic diencephalic expression pattern. Here, we use transgenic strategies andin vitroexperiments to test the hypothesis thatShhexpressed in the diencephalic neuroepithelium (neuralShh) coordinates tissue growth and patterning in the hypothalamus. Our results show that neuralShhcoordinates anteroposterior and dorsoventral patterning in the hypothalamus and in the diencephalon–telencephalon junction. NeuralShhalso coordinates mediolateral hypothalamic patterning, since it is necessary for the lateral hypothalamus to attain proper size and is required for the specification of hypocretin/orexin cells. Finally, neuralShhis necessary to maintain expression of differentiation markers including survival factorFoxb1.
In Mice Lacking V2a Interneurons, Gait Depends on Speed of Locomotion
Authors: Crone Steven A. , Zhong Guisheng , Harris-Warrick Ronald , Sharma Kamal
Published: May 2009

Many animals are capable of changing gait with speed of locomotion. The neural basis of gait control and its dependence on speed are not fully understood. Mice normally use a single “trotting” gait while running at all speeds, either over ground or on a treadmill. Transgenic mouse mutants in which the trotting is replaced by hopping also lack a speed-dependent change in gait. Here we describe a transgenic mouse model in which the V2a interneurons have been ablated by targeted expression of diphtheria toxin A chain (DTA) under the control of theChx10gene promoter (Chx10::DTA mice). Chx10::DTA mice show normal trotting gait at slow speeds but transition to a galloping gait as speed increases. Although left–right limb coordination is altered in Chx10::DTA mice at fast speed, alternation of forelegs and hindlegs and the relative duration of swing and stance phases for individual limbs is unchanged compared with wild-type mice. The speed-dependent loss of left–right alternation is recapitulated during drug-induced fictive locomotion in spinal cords isolated from neonatal Chx10::DTA mice, and high-speed fictive locomotion evoked by caudal spinal cord stimulation also shows synchronous left–right bursting. These results show that spinal V2a interneurons are required for maintaining left–right alternation at high speeds. Whether animals that generate galloping or hopping gaits, characterized by synchronous movement of left and right forelegs and hindlegs, have lost or modified the function of V2a interneurons is an intriguing question.
Cerebral Activity during the Anesthesia-Like State Induced by Mesopontine Microinjection of Pentobarbital
Authors: Abulafia Ruth , Zalkind Vladimir , Devor Marshall
Published: May 2009

Microinjection of pentobarbital into a restricted region of rat brainstem, the mesopontine tegmental anesthesia area (MPTA), induces a reversible anesthesia-like state characterized by loss of the righting reflex, atonia, antinociception, and loss of consciousness as assessed by electroencephalogram synchronization. We examined cerebral activity during this state using FOS expression as a marker. Animals were anesthetized for 50 min with a series of intracerebral microinjections of pentobarbital or with systemic pentobarbital and intracerebral microinjections of vehicle. FOS expression was compared with that in awake animals microinjected with vehicle. Neural activity was suppressed throughout the cortex whether anesthesia was induced by systemic or MPTA routes. Changes were less consistent subcortically. In the zona incerta and the nucleus raphe pallidus, expression was strongly suppressed during systemic anesthesia, but only mildly during MPTA-induced anesthesia. Dissociation was seen in the tuberomammillary nucleus where suppression occurred during systemic-induced anesthesia only, and in the lateral habenular nucleus where activity was markedly increased during systemic-induced anesthesia but not following intracerebral microinjection. Several subcortical nuclei previously associated with cerebral arousal were not affected. In the MPTA itself FOS expression was suppressed during systemic anesthesia. Differences in the pattern of brain activity in the two modes of anesthesia are consistent with the possibility that anesthetic endpoints might be achieved by alternative mechanisms: direct drug action for systemic anesthesia or via ascending pathways for MPTA-induced anesthesia. However, it is also possible that systemically administered agents induce anesthesia, at least in part, by a primary action in the MPTA with cortical inhibition occurring secondarily.
Subthreshold Glutamate Release from Mitral Cell Dendrites
Authors: Castro Jason B. , Urban Nathaniel N.
Published: May 2009

The dendrites of a number of neuron types function as presynaptic structures, releasing transmitter after action potentials and dendritic spikes. In this regard, dendrites can function like axons, producing discrete outputs after suprathreshold electrical events. However, as the major site of synaptic inputs, dendrites experience ongoing subthreshold fluctuations in membrane potential, raising the question of whether these subthreshold changes can cause changes in transmitter release. Here, we show that mitral cells of the accessory olfactory bulb release glutamate from their dendrites in response to both subthreshold and suprathreshold stimuli. Whereas subthreshold output was typically low under control conditions, it could be enhanced several fold by pharmacological or endogenous activation of group I metabotropic glutamate receptors. These results indicate that presynaptic dendrites can support two distinct forms of output, and can dynamically regulate how electrical activity is coupled to transmitter release.
Recurrent acral lentigous melanoma successfully treated with Mohs’ micrographic surgery. Case report and review of the literature
Authors: Mátrai Zoltán , Plotár Vanda , Liszkay Gabriella , Fejős Zsuzsanna , Vámosi Ágnes , Dubóczky Zsolt , Rényi Vámos Ferenc , Vámosi Nagy István , Köves István , Bartal Alexandra , Schmidt Emese , Tóth László
Published: May 2009

Meghatározott bőrtumoroknál a Mohs-féle mikrográfikus sebészeti eljárás kínálja a legjobb lehetőséget a tumor teljes eltávolítása mellett a maximális funkcionális és kozmetikai állapot megtartására. A módszer előnye, hogy horizontálisan vezetett fagyasztásos metszetekkel a specimen sebészi széleinek 100%-át, beleértve a perifériás és mély felszínt is, intraoperatívan vizsgálja. Ez az eljárás a konvencionális sebészi kimetszéssel vagy más technikával szemben szignifikánsan magasabb ablasticitást eredményez. A Mohs-féle mikrográfikus sebészet a választandó beavatkozás nagy, kiújult vagy inkomplett módon eltávolított bőrdaganatok esetén, illetve ha a daganat funkcionálisan vagy esztétikailag kényes anatómiai régiót érint. A szerzők egy 75 éves férfi esetét mutatják be, akinél a talpon másodszor lokálisan kiújult invazív melanoma malignumot kezeltek sikeresen Mohs-féle mikrográfikus sebészeti technikával, azonnali rekonstrukcióval, félvastag lebenyt alkalmazva.
Effects of Increasing Chinook Salmon Bag Limits on Alewife Abundance: Implications for Lake Michigan Management Goals
Authors: Claramunt Randall M. , Kolb Tracy L. , Clapp David F. , Hayes Daniel B. , Dexter James L. , Warner David M.
Published: May 2009

To predict effects of modifying the daily bag limit (DBL) on management of Chinook salmon Oncorhynchus tshawytscha and alewives Alosa pseudoharengus, we analyzed harvest and effort data collected from both charter and noncharter anglers during 1997–2005 in Michigan waters of Lake Michigan. Overall, the percent of anglers who caught the DBL of three Chinook salmon was low for charter (10.2%) and noncharter (3.3%) angler groups. However, during 1997–2005, the percent of anglers that caught their DBL increased from 3.3% to 26.5% for charter anglers and from 0.5% to 7.8% for noncharter anglers. To predict harvest under a higher DBL, we fit a discrete negative binomial distribution to the observed daily harvest distribution under the current DBL of three fish. We then used the fitted negative binomial to predict the daily harvest distribution under a DBL of five fish. Using this approach, the potential increase in the number of fish harvested with the higher DBL was minimal, but the additional harvest showed an increasing 1997–2005 trend from 315 to 7,301 fish for charter anglers and from 450 to 18,151 fish for noncharter anglers. There was a positive linear relationship between proportion of anglers harvesting the current DBL and harvest rates, which indicates that angler success is a function of Chinook salmon abundance. Using an age-structured deterministic population model and the production-conversion efficiency method, we estimated potential reduction in annual lakewide consumption of alewives by Chinook salmon resulting from a higher DBL. The reduction in consumption averaged 313 metric tons and increased from 28 (1997) to 935 metric tons (2005). We conclude that higher DBLs would have a relatively minor impact on lakewide forage fish abundance but would be more consistent with current management objectives.
Conditional Capture Probability of Scaphirhynchus spp. in Drifting Trammel Nets
Authors: Guy Christopher S. , Oldenburg Eric W. , Gerrity Paul C.
Published: May 2009

Pallid sturgeon Scaphirhynchus albus and shovelnose sturgeon S. platorynchus are commonly sampled using drifting trammel nets in the Missouri and Mississippi river basins. Despite the fact that drifting trammel nets have been used for decades to sample these species, little is known about the capture efficiency of this gear. We estimated conditional capture probability for drifting trammel nets over known locations of pallid sturgeon and shovelnose sturgeon. In addition, we examined several variables that were predicted to influence the success of capturing a pallid sturgeon or shovelnose sturgeon in a drifting trammel net. Conditional capture probability (the conditioning factor was known presence) varied from 0.37 on the first attempt to 0.51 on the second attempt. None of the variables measured were useful in explaining the success of sampling a fish in a drifting trammel net. Drifting trammel nets are relatively efficient, and we suggest that they continue to be used to sample pallid sturgeon and shovelnose sturgeon in large turbid rivers. The high variability in catch per unit effort associated with sampling pallid sturgeon and shovelnose sturgeon using drifting trammel nets reported in the literature is probably related to the their low abundance (primarily pallid sturgeon) and patchy distribution (both species). Thus, using sampling designs appropriate for species with low abundance or patchy distributions rather than sampling designs commonly used for abundant species with ubiquitous distributions will require less effort because drifting trammel nets are relatively efficient.
Mouse models of altered protein kinase A signaling
Authors: Kirschner Lawrence S , Yin Zhirong , Jones Georgette N , Mahoney Emilia
Published: May 2009

Protein kinase A (PKA) is an evolutionarily conserved protein which has been studied in model organisms from yeast to man. Although the cAMP–PKA signaling system was the first mammalian second messenger system to be characterized, many aspects of this pathway are still not well understood. Owing to findings over the past decade implicating PKA signaling in endocrine (and other) tumorigenesis, there has been renewed interest in understanding the role of this pathway in physiology, particularly as it pertains to the endocrine system. Because of the availability of genetic tools, mouse modeling has become the pre-eminent system for studying the physiological role of specific genes and gene families as a means to understanding their relationship to human diseases. In this review, we will summarize the current data regarding mouse models that have targeted the PKA signaling system. These data have led to a better understanding of both the complexity and the subtlety of PKA signaling, and point the way for future studies, which may help to modulate this pathway for therapeutic effect.
Effect of superplasticisers on adsorption, rate of cement hydration, and pore structure of cement pastes
Authors: Sun D.-J. , Sisomphon K. , Zhang M.-H.
Published: May 2009

This paper presents an experimental study on the effect of three superplasticisers, polycarboxylate (PCE), naphthalene (SNF) and a newly developed modified lignosulphonate (PLS), on admixture adsorption, rate of cement hydration, and pore structure of cement pastes. The mixtures were designed to achieve similar workability at w/c ratios of 0·34 and 0·40, thus both type and dosage of the admixtures had influence on various properties. The results indicate that the adsorption was strongly dependent on the type of superplasticiser used in the cement paste. The superplasticisers delayed cement hydration at early age, but did not have significant effect on the cement hydration from 7 to 91 days. The retardation of the pastes was in the order of SNF ≤ssthan PCE ≤ssthan PLS. These superplasticisers also had influence on the total porosity and pore size distribution of the cement pastes which would have potential influence on permeability of concrete.
Influence of gypsum on composition and performance of hardened paste of belite-barium
Authors: Wu H.X. , Lu L.C. , Chen C. , Liu S.Q. , Wang H. , Cheng X.
Published: May 2009

Belite-barium calcium sulphoaluminate cement is a new kind of binding material. The mineral phases of the cement clinker are mainly C3S, C2S, C3A, C4AF and C2·75B1·25A3S. The influence of gypsum on the composition and performances of hardened cement paste was studied. The composition and structure of hardened cement paste were analysed by means of X-ray diffraction and scanning electron microscopy. The results show that the compressive strengths of belite-barium calcium sulphoaluminate cement with 10% gypsum addition at 3, 7, 28 and 90 days curing age were 45·0, 61·9, 82·1 and 85·6 MPa. The hydration products of the cement were mainly AFt, Ca(OH)2 and C–S–H gel. With increasing addition of gypsum, the amount of AFt and C–S–H gel increased and the amount of Ca(OH)2 decreased gradually at later hydration age. In comparison with belite cement, the hardened paste of belite-barium calcium sulphoaluminate cement has more C–S–H gel and a denser structure.
Setting and strength development of magnesium phosphate cement paste
Authors: Qiao F. , Chau C.K. , Li Z.
Published: May 2009

Magnesium phosphate cement (MPC) paste is prepared by mixing dead-burned magnesia powder and potassium di-hydrogen phosphate with a proper proportion of water. The paste demonstrates superior performance such as fast setting, high early-strength, low shrinkage and good bonding which makes MPC suitable for applications in the rapid repair of infrastructures. However, it has been found that MPC easily sets in a few minutes and thus causes difficulties in manipulation. Therefore, how to retard and control the setting time of MPC becomes a challenging problem in both scientific and engineering fields. The setting time of MPC is greatly influenced by the reactivity of magnesia. A reliable, effective and economic test method has been developed to measure the reactivity of magnesia. In the present study, two kinds of magnesia, namely, high-reactivity magnesia and low-reactivity magnesia were blended in order to adjust the setting process of MPC. The effects of blending ratio and molar ratio of magnesia to phosphate and borax addition on setting time and compressive strength of MPC cement paste were investigated. Finally, the reaction product and reaction mechanism were examined and discussed.
Study and Application of Reservoir Protection Fluid System for Drilling & Completion Using Oil-film Method
Authors: Jiang G. C. , Ji C. F. , Ma X. P.
Published: May 2009

To protect reservoir during drilling, the upper drilling fluid is generally converted into reservoir protection fluid by adding proper graded temporary plugging materials based on the average radius of pore throat in reservoir, coupled with colloid filling particles. However, the fluid converted has a better temporary plugging effect on only some well section but all well sections, because of wide distribution of average radius of pore throat in reservoir. Aiming at present problems of reservoir protection drilling & completion fluid technology and reservoir characteristics such as strong heterogeneity, wide distribution of pore diameter, difficultly accurate prediction of pore diameter in reservoir etc, broad-spectrum oil-film fielding temporary plugging agent GPJ was developed and the oil-film method used for reservoir protection drilling & completion fluid systems were established. The lab evaluation and field tests showed that not only there is a good compatibility between GPJ and common drilling fluid systems but also plugging rate and recovery rate of cores treated by the developed systems both are over 90%, field test skin factor is close to zero, thus the developed systems have a better reservoir protection effect than conventional systems and can help to increase daily oil production.
Hydrate Blockage in Subsea Water Injection Wells - Causes and Preventive Procedures
Authors: Rodrigues Valdo F. , Frota Helder M. , Loures Luiz G. , Siqueira Fernando D.
Published: May 2009

Hydrate blockage has been a problem in Campos Basin subsea producer wells for a long time. Although hydrate formation was not expected in sea water injection wells there were some occurrences in Campos Basin. The formation of hydrate requires the presence of water and gas at low temperature and high pressure condition. As the subsea sea water injection wells always present water at low temperature and high pressure, the missing link to form hydrate is gas. Thus, to explain the occurrence of hydrate blockage in these wells one has to explain how and when gas enters into the well. A study was carried out to determine the causes of gas inflow into the injection strings and to make recommendations on the proper procedures and equipments to avoid hydrate blockage. The literature survey and the Campos Basin occurrences showed initially that gas segregation, water hammer effects and crossflow were the most probable causes for gas inflow during injection plant shutdowns or long time waiting for injection. The crossflow was ignored because the formations are homogeneous in all the cases. The water hammer effects were analyzed with a numerical simulator developed in the study. The final analyses revealed that gas segregation was the cause of hydrate blockage in the water injection wells studied. Other relevant conclusions are that down hole valves, such as deep subsurface safety valves and backflow valves are useless to prevent gas inflow and that water hammer effects can be managed in the sea water injection plant. This paper presents recommendations for water injection wells startups, regarding hydrate prevention, which can be useful for any subsea water injection project.
Novel Chelating-Based Technology Application in Complex and Heterogeneous Injector Wells in the Algyo Field, Hungary
Authors: Urraca Martin , Udvari Ferenc
Published: May 2009

The geologically complex Algyo field, discovered in 1965, is the largest hydrocarbon occurrence in Hungary, consisting of more than 40 oil-and-gas-bearing layers. The Ap-13, is one of the biggest reservoirs and encompasses a myriad of challenges: it is a depleted (180 bars reservoir pressure at 2400 m) layered dirty sandstone reservoir with a low permeability of approximately 15 mD, containing saturated oil. The 122°C temperature, complex mineralogy, poor consolidation, and a wide range of sources of potential formation damage make any stimulation a challenging and detailed process.

Water injection is one the most commonly used exploitation method because of its favorable results. Sustained injection rate with delimited surface pressure is necessary to maintain the operational and economical advantages; however, formation damage severely impacts the injection trend.

Conventional stimulation systems such as acid outside-phase emulsion and regular mud acids have been used in the past on Algyo injector wells to improve injectivity by targeting the possible sources of damage such as iron compounds, calcite, hydrocarbons, clays, and sand; however, the effectiveness of these treatments has had a limited effective time frame of a few months, with suspected rock disintegration in the near-wellbore area.

Through virtual geochemical simulation and laboratory testing, a novel chelating system was identified as the most suitable technology to efficiently stimulate the Ap-13 reservoir and overcome the inherent extreme conditions.

Three injector wells were treated with this technology, and now, two years later, stable injection rates at optimum surface pressures are still maintained. These favorable results have widened the potential application of the technology to oil and gas wells, and laboratory testing has been optimized through virtual geochemical simulation. Furthermore, the operational risk of stimulation treatment is reduced where no cores are available, such as old wells, or when timing is a constraint, as in exploration wells.
Silanol Resin Consolidation System for Deepwater Completions and Production Optimization
Authors: Kurawle Irfan , Mahalle Nakul , Kaul Mohit , Nair Amith , Kulkarni Nikhil
Published: May 2009

Sand control has traditionally been one of the biggest problems affecting production facilities and the design of surface equipment leading to escalation of project costs. With industry venturing into deeper waters and rising crude prices it's essential to develop complete and forget techniques for offshore locations most probable to produce sand. Hence a proper analysis for sand prediction and management has been at the forefront in research by many companies.

The most viable alternative today being gravel packs although requiring constant attention as seen through various literature reviews. We emphasized on the chemical consolidation technique for sand control which has been overlooked but is promising considering escalating maintenance costs. We would like to introduce a new resin consolidation system which is cost effective and withstand very high pressures and temperature ranges from 50 °F to 450 °F. The resin consists of Aromatic Polyesteramide and Tri-alkoxy organo silane based consolidation system. The chemicals combine together on contact with formation water to essentially hydrolyze it at the sites to form a strong silanol adhesive which bonds the grains together thus giving a highly strong bond. The highlight of the paper is the process of consolidation which is site specific thus preventing the considerable loss in porosity and permeability as is generally seen in chemical consolidation systems. The paper describes the complete properties of the polymer resin system and the process of consolidation with the new system. In addition it describes the advantages of being environmental friendly and easier to handle with comparison to certain furan based resin systems that are currently used in the industry and have handling issues.
An Alternative Method for Predicting Injectivity Decline in Produced Water Re-Injection
Authors: Bai Mao , McLennan John , Standifird William
Published: May 2009

In this paper, a semi-empirical method for evaluating the injectivity decline in a produced water reinjection operation is proposed. The characteristics of injectivity decline during the pumping of produced water are represented as two-stage behavior - an early exponential decay and a late linear declining injectivity. The analytical modeling of coupled flow-transport phenomena for a two-layered medium reveals that the particle deposition during produced water re-injection constitutes a critical component of two stage decay-fading responses. The method was validated through matches between the modeling results and field measurements. The investigated concepts and developed technologies detailed in this paper can be applied directly to the produced water re-injection operations in order to predict possible injectivity decline and assist in understanding the mechanisms behind the decline phenomenon.
Sand Consolidation Testing in an API RP 19B Section IV Perforation Flow Laboratory
Authors: Haggerty D. J. , Manning J. D. , Nguyen P. D. , Rickman R. D. , Dusterhoft R. G.
Published: May 2009

Formation consolidation is a form of sand control that was used extensively in the past, but has been largely replaced by mechanical systems, such as gravel packs or expandable screens. This change has arisen because of a level of uncertainty regarding effective chemical placement and reliability. Challenging economics in the petroleum industry began to make alternative completion techniques more attractive for remediation applications, for developing and producing by-passed reserves behind blank pipe, and for completing marginal reservoirs. Low-cost completion alternatives are actively being sought for both injectors and producers.

To understand the performance of various consolidation options, a series of tests was performed on samples of Castlegate sandstone, incorporating actual perforating operations in the lab to evaluate both treatment placement and performance under reservoir conditions. This paper provides details about the testing process that was used, as well as comparative results for various consolidation technologies, including curable and non-curable agents resulting in various degrees of cohesion between formation particulates. Post treatment evaluations included flow testing single and dual phase fluids under in-situ conditions, as well as post mortem evaluations of chemical placement and mechanical properties.

Section IV perforation flow testing provided a realistic modeling technique to understand the effectiveness of a consolidating agent with respect to its placement or coating behavior, which in turn directly affects the resulting strength and retained permeability after chemical treatment. Results from the flow testing indicate that a critical strength is required to lock the treated sand in place and to overcome the drag force generated by flow. Depth of treatment penetration into the formation matrix is a function of treatment volume, pressure drop, and permeability. The amount of consolidating agent coating on the sand and the resulting strength depend on the concentration of the agent in the treatment solution. With efficient strength as a result of the consolidating agent treatment, only a small quantity of sand was observed to produce from the treated perforation, either with single or dual phase fluids, when compared to a much larger amount of sand produced from the perforation that lacked treatment, even when the perforation was subjected to a lower flow rate.
Modeling the Effect of Asphaltene on the Development of the Marrat Field
Authors: Yi T. , Fadili A. , Ibrahim M. , Al-Matar B. S.
Published: May 2009

This paper describes the study of the effect of asphaltene precipitation and deposition on the development of the Marrat field using a compositional simulation model with asphaltene modeling facilities. The model enables the simulation of asphaltene precipitation, flocculation, and deposition including adsorption, plugging, and entrainment, and the resulting reduction in porosity and permeability and changes in oil viscosity and rock wettability. A workflow was established in the study to i) characterize the equation of state (EOS) by analyzing the fluid PVT and asphaltene data from the lab; ii) calibrate the asphaltene model input parameters using the core flood experimental data; and iii) incorporate the EOS and the asphaltene parameters into the full field simulation model.

The model was used to analyze the effects of asphaltene on various development scenarios, including depletion and water injection. For each scenario, the following were calculated and analyzed: field performance including production of oil, gas, and water; asphaltene behavior including precipitation, flocculation, adsorption, plugging and entrainment; formation damage and the effect of rock wettablity changes.

The results show that the formation could be severely damaged near the producers where asphaltene is more likely to precipitate because of lower pressures (below the asphaltene onset pressure) and longer time exposure to a larger amount of oil. Formation damage could be reduced by flushing away the deposited asphaltene using higher flow rates if plugging is not significant. The water injection scenario with higher injection rate and higher production rate with BHP limit above 6,000 psia results in less asphaltene adsorption, more entrainment, and therefore less deposition. This in turn causes less permeability damage and more oil production.