bluuebunny/crossref_metadata_2025_split huggingface dataset:
NMR and EPR studies of membrane transporters
Authors: Hellmich Ute A. , Glaubitz Clemens 
Published: May 2009

Abstract
In order to fulfill their function, membrane transport proteins have to cycle through a number of conformational and/or energetic states. Thus, understanding the role of conformational dynamics seems to be the key for elucidation of the functional mechanism of these proteins. However, membrane proteins in general are often difficult to express heterologously and in sufficient amounts for structural studies. It is especially challenging to trap a stable energy minimum, e.g., for crystallographic analysis. Furthermore, crystallization is often only possible by subjecting the protein to conditions that do not resemble its native environment and crystals can only be snapshots of selected conformational states. Nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) spectroscopy are complementary methods that offer unique possibilities for studying membrane proteins in their natural membrane environment and for investigating functional conformational changes, lipid interactions, substrate-lipid and substrate-protein interactions, oligomerization states and overall dynamics of membrane transporters. Here, we review recent progress in the field including studies from primary and secondary active transporters.
Structural and functional aspects of the multidrug efflux pump AcrB
Authors: Eicher Thomas , Brandstätter Lorenz , Pos Klaas M. 
Published: May 2009

Abstract
The tripartite efflux system AcrA/AcrB/TolC is the main pump in Escherichia coli for the efflux of multiple antibiotics, dyes, bile salts and detergents. The inner membrane component AcrB is central to substrate recognition and energy transduction and acts as a proton/drug antiporter. Recent structural studies show that homotrimeric AcrB can adopt different monomer conformations representing consecutive states in an allosteric functional rotation transport cycle. The conformational changes create an alternate access drug transport tunnel including a hydrophobic substrate binding pocket in one of the cycle intermediates.
Pharmacological inhibitors to identify roles of cathepsin K in cell-based studies: a comparison of available tools
Authors: Desmarais Sylvie , Massé Frédéric , Percival M. David 
Published: May 2009

Abstract
Cathepsin K (Cat K) degrades bone type I collagen and is a target for the pharmacological treatment of osteoporosis. Further roles for Cat K have been recently described, some of which are supported by the use of purportedly selective Cat K inhibitors in human and rodent cell-based assays. Twelve commercial and non-commercial Cat K inhibitors were profiled against a panel of purified human, rat, and mouse cysteine cathepsins and in two cell-based enzyme occupancy assays for activity against Cat K, B, and L. Ten inhibitors, including the carbohydrazide Cat K inhibitor II (Boc-Phe-Leu-NHNH-CO-NHNH-Leu-Z), the non-covalent K4b, and the epoxide NC-2300, have either little Cat K selectivity, or appear poorly cell penetrant. The amino-acetonitrile-containing inhibitors L-873724 and odanacatib show greater than 100-fold human Cat K enzyme selectivity and have similar IC50 values against each cathepsin in cell-based and enzyme assays. The basic inhibitor balicatib has greater cellular potencies than expected on the basis of purified enzyme assays. The accumulation of [14C]-balicatib in fibroblasts is blocked by prior treatment of the cells with NH4Cl, consistent with balicatib having lysosomotropic properties. These results support the use of L-873724 and odanacatib as tools to identify novel roles for Cat K using human cell-based systems, but suggest using caution in the interpretation of studies employing the other compounds.
The role of ghrelin and ghrelin-receptor gene variants and promoter activity in type 2 diabetes
Authors: Garcia Edwin A , King Peter , Sidhu Kally , Ohgusu Hideko , Walley Andrew , Lecoeur Cecile , Gueorguiev Maria , Khalaf Sahira , Davies Derek , Grossman Ashley B , Kojima Masayasu , Petersenn Stephan , Froguel Phillipe , Korbonits Márta 
Published: May 2009

BackgroundGhrelin and its receptor play an important role in glucose metabolism and energy homeostasis, and therefore they are functional candidates for genes carrying susceptibility alleles for type 2 diabetes.MethodsWe assessed common genetic variation of the ghrelin (GHRL; five single nucleotide polymorphisms (SNP)) and the ghrelin-receptor (GHSR) genes (four SNPs) in 610 Caucasian patients with type 2 diabetes and 820 controls. In addition, promoter reporter assays were conducted to model the regulatory regions of both genes.ResultsNeither GHRL nor GHSR gene SNPs were associated with type 2 diabetes. One of the ghrelin haplotypes showed a marginal protective role in type 2 diabetes. We observed profound differences in the regulation of the GHRL gene according to promoter sequence variants. There are three different GHRL promoter haplotypes represented in the studied cohort causing up to 45% difference in the level of gene expression, while the promoter region of GHSR gene is primarily represented by a single haplotype.ConclusionThe GHRL and GHSR gene variants are not associated with type 2 diabetes, although GHRL promoter variants have significantly different activities.
Pandemic Influenza and Pregnant Women: Summary of a Meeting of Experts
Authors: Rasmussen Sonja A. , Jamieson Denise J. , MacFarlane Kitty , Cragan Janet D. , Williams Jennifer , Henderson Zsakeba 
Published: May 2009

Pandemic Influenza: Special Considerations for Pregnant Women was a meeting convened by the Centers for Disease Control and Prevention in 2008 to obtain input from experts and key partners regarding clinical management of pregnant women and related public health actions to be taken during a pandemic. Meeting goals were to discuss issues specific to pregnant women, identify gaps in knowledge, and develop a public health approach for pregnant women in the event of a pandemic. The meeting focused on 4 main topics: prophylaxis and treatment with influenza antiviral and other medications, vaccine use, nonpharmaceutical interventions and health care planning, and communications. Participants reviewed the available evidence to guide action in each of these areas and identified areas of critical needs for future research.
Disparities in Influenza Treatment Among Disabled Medicaid Patients in Georgia
Authors: Leon Kyla , McDonald Marian C. , Moore Barbara , Rust George 
Published: May 2009

Objectives. We explored possible disparities in seasonal influenza treatment in Georgia's disabled Medicaid population. We sought to determine whether racial/ethnic, geographic, or gender disparities existed in antiviral drugs usage in the treatment of influenza.Methods. Medicaid claims were analyzed from 69 556 clients with disabilities enrolled in a Georgia Medicaid disease management program.Results. There were 519 patients who met inclusion criteria (i.e., adults aged 18–64 years with an influenza diagnosis on a 2006 or 2007 Medicaid claim). Roughly one third (36.2%) of patients were classified as African American, 44.5% as White, and 19.3% as “other.” Most patients had 2 or more comorbid chronic diseases. Antivirals were used in only 14.5% of patients diagnosed with influenza. Treatment rates were nearly 3 times higher for White patients (19.5%) than for African American patients (6.9%).Conclusions. Our analysis suggests limited use of antiviral treatment of influenza overall, as well as significant racial disparities in treatment. Additional studies are needed to further explore this finding and its implications for care of racial/ethnic minority populations during seasonal influenza and for effective pandemic influenza planning for racial/ethnic minority populations.
Effect of Data Errors on Typical Reservoir Engineering Calculations
Authors: Hutchinson Charles A. 
Published: May 2009

Abstract
In reservoir analysis important quantities such as reservoir pressure, in-place oil, and well damage are calculated from directly measured quantities and each measurement error has an effect on the calculated result. This paper employs statistical methods in the quantitative consideration of the effect of these measurement errors on answers calculated by specific formulas which may be taken as typical of reservoir engineering calculations. Detailed studies have been made concerning reservoir pressure, reservoir pressure decline, initial in-place gas in distillate fields, initial in-place oil in unsaturated fields, initial in-place oil in solution gas drive fields, and well damage. A wide range of examples is presented so that the conclusions may be generally applicable. Various intangible factors which cannot be included in the equations limit the quantitative applicability of the calculated error, but these factors reinforce rather than detract from the conclusions. Particular attention is given to the effect of bottom hole pressure measurements errors. The overall conclusion from this study is that in nearly all cases the errors in bottom hole pressure measurements make the major error in reservoir engineering calculations and that in many instances an increased accuracy of the pressure instruments to ±1 psi is highly desirable.

Introduction
The question of what accuracy is required in the data assembled for the purpose of making reservoir analyses has been the subject of much discussion in the past. Extremes of opinion have been encountered, ranging from a belief that reservoir analysis is approximate at best and that very approximate data are sufficient to an insistence that all factors be measured to the utmost possible precision.
Hydrafrac Operations in the Spraberry Production, West Texas
Authors: Grossman Waldo L. 
Published: May 2009

Abstract
During late 1950 and up to present date in 1951 the Spraberry sand production of West Texas has created wide-spread interest in the oil producing industry. It is recognized that there are many controversial opinions concerning operations in the Spraberry, it's economic value, and future development.
The application of Hydrafrac procedures to completion of Spraberry wells has become prominent in the development of these sands. This paper outlines the geologic and historical development of the Spraberry and the use of Hydrafrac applications in these formations.

Introduction
The application of the Hydrafrac Process to wells completing from the Spraberry formation was begun during the last part of 1950. The Hydrafrac Process consists of preparing a viscous gel to which a special sand is added and pumping this material into the producing formation at a rate which will develop sufficient hydraulic force to produce and/or extend a fracture. The gel must be of an unstable character to revert to a thin fluid, such that it may be recovered from the well, leaving the introduced sand in the fracture as a propping agent. In order to insure the reversion of gel to a fluid, breaker chemicals are mixed with crude oil and flushed into the formation behind the gel. The success of these treatments has been closely associated nth the current expanding drilling and development program along an area commonly referred to as the Spraberry Trend. 'Top of Spraberry' is found at depths of 6,500 to 7,500 feet in most of this area.
This trend covers an area over 100 miles in length and 50 miles in width from the North Gail Field of Borden County to the Flatrock Field of Upton County. Location of this eight county area of West Texas is shown in Figure 1.Location of the fields discovered through June 1951 are shown in Figure 2.
Mud Analysis Logging And Its Use In Formation Evaluation
Authors: Wilson R.W. 
Published: May 2009

Introduction
Mud logging is the term applied to the process of analyzing the drilling mud and cuttings for oil and gas and correlating these shows with the depth of the formations from which they came. The amounts of oil and gas found in the mud and cuttings from productive formations vary widely due to variations in drilling practice and in formation characteristics. Hence, mud logging does not furnish quantitative information useful to engineers in calculating reserves for productivity of formations. Its principal usefulness is as an aid to formation evaluation in exploratory wells by detecting and locating oil and gas occurrences as the well is drilled. In contrast to other logging methods in which the presence of oil and gas is inferred from the measurements of physical properties of the formation, mud logging affords a direct determination of oil and gas in the formation. It is an around-the-clock program to assure that all oil and gas-bearing formation will be detected during the drilling of the well. The wide application of mud logging on exploratory wells attests to its usefulness. Approximately 300 units of mud logging equipment are now being used in this country.

Scope and Applications
Mud logging is done in a mobile laboratory at the wellsite while the well is drilled. The operator with the equipment at his command does the following:Detects gas in the drilling mud continuously and in the cuttings intermittentlyDetects oil in drilling mud and cuttings samples intermittentlyDescribes the well cuttings by mineral content, color, texture, etc.Logs the progress of the drill, the depth and drilling rate, and the circulation of drilling mud through the hole, and relates showings to their depth of originDetermines mud properties intermittently and observes the rig operation as it may affect the mud logging results
From the results obtained a log such as that of Fig. 1 is drawn.
How safe is the use of prosthetic materials in the repair of abdominal-wall defects in malnourished subjects?
Authors: Karahan Mehmet , Kulacoglu Hakan , Seker Duray , Ergul Zafer , Kiziltay Aysel , Yilmazer Demet , Captug Ozge , Yavuz Alper , Serbetci Kemal , Bilgili Hasan , Hasirci Nesrin 
Published: May 2009

AbstractIncisional hernias and abdominal-wall defects consume large amounts of healthcare resources. Use of mesh is effective in treatment of these disorders and can decrease the rate of recurrence. This experimental study focused on the safety of mesh use in the setting of malnutrition, a condition that impairs wound healing. Rats were divided into two groups: normally fed and food-restricted. An abdominal-wall defect, 2 by 2 cm, was covered with polypropylene mesh, 2.5 by 2.5 cm. After sacrifice of the rats at the 21st and 60th days, tissue samples were sent for tensiometric and histopathological studies. No significant difference in infectious complications was observed between the two groups. Tensiometry revealed no significant differences between the groups. On histopathological examination, the only difference noted was in the vascularization scores of normally fed rats. For malnourished subjects that survived after surgery, the use of polypropylene mesh appeared safe in the closure of abdominal-wall defects, with no increase in infection rate and satisfactory wound healing.
Incidence of basioccipital hypoplasia in Chiari malformation Type I: comparative morphometric study of the posterior cranial fossa
Authors: Noudel Rémy , Jovenin Nicolas , Eap Cristophe , Scherpereel Bernard , Pierot Laurent , Rousseaux Pascal 
Published: May 2009

Object
The chronic tonsillar herniation defining Chiari malformation Type I (CMI) is thought to result from overcrowding of a normally developing hindbrain within a congenitally small posterior cranial fossa (PCF) due to occipital hypoplasia. The goals in the present study were to authenticate the cranioencephalic disproportion in a group of patients with CMI and to discuss new developmental aspects according to which part of the occipital bone was underdeveloped.

Methods
The authors retrospectively examined a group of 17 patients with CMI. Measurements of osteotentorial and neural structures of the PCF were made on MR images of the brain. The results were compared with findings in 30 healthy controls by using the Mann-Whitney U-test.

Results
Dimensions of the neural structures did not differ between the 2 groups of patients. The mean length of the basiocciput was significantly shorter in the CMI group (19.4 mm) compared with the control group (25.7 mm; p = 0.0003). The mean diameter of the foramen magnum was larger in the CMI group, but this difference was not statistically significant. The dimensions of the supraocciput and the mean angle of the cerebellar tentorium were identical in the 2 groups.

Conclusions
Data in this study support the idea that occipital hypoplasia is the main cause of overcrowding within the PCF. Basioccipital shortness is a cardinal feature of the resultant shallow PCF and could proceed from a congenital disorder of the cephalic mesoderm of the parachordal plate or occur later in the infancy because of premature stenosis of the sphenooccipital synchondrosis.
Flowers Are an important food for small apes in southern Sumatra
Authors: Lappan Susan 
Published: May 2009

AbstractFlowers are included in the diets of many primates, but are not generally regarded as making an important contribution to primate energy budgets. However, observations of a number of lemur, platyrrhine, and cercopithecine populations suggest that some flower species may function as key primate fallback foods in periods of low abundance of preferred foods (generally ripe fruits), and that flowers may be preferred foods in some cases. I report heavy reliance on flowers during some study months for a siamang (Symphalangus syndactylus) population in southern Sumatra. Siamangs at Way Canguk spent 12% of feeding time eating flowers from October 2000 to August 2002, and in 1 month flower‐feeding time exceeded 40% of total feeding time. The overall availabilities of fig and nonfig fruits, flowers, and new leaves in the study area were not significant predictors of the proportion of time that siamangs spent consuming any plant part. However, flower‐feeding time was highest in months when nonfig fruit‐feeding time was lowest, and a switch from heavy reliance on fruit to substantial flower consumption was associated with a shift in activity patterns toward reduced energy expenditure, which is consistent with the interpretation that flowers may function as a fallback food for Way Canguk siamangs. Hydnocarpus gracilis, a plant from which siamangs only consume flowers, was the third‐most‐commonly consumed plant at Way Canguk (after Ficus spp. and Dracontomelon dao), and flowers from this plant were available in most months. It is possible that relatively high local availability of these important siamang plant foods is one factor promoting high siamang density in the study area. Am. J. Primatol. 71:624–635, 2009. © 2009 Wiley‐Liss, Inc.
Me3SiCl and Et3SiI‐promoted one‐pot synthesis of 1,4‐dihydropyridine derivatives
Authors: Mirza‐Aghayan Maryam , Langrodi Mahboubeh Khoshkameh , Rahimifard Mahshid , Boukherroub Rabah 
Published: May 2009

AbstractAn efficient synthesis of 1,4‐dihydropyridine derivatives has been achieved by the one‐pot cyclocondensation reaction of methyl 3‐aminocrotonate and a range of aldehydes in the presence of chlorotrimethylsilane as a promoter under solvent‐free conditions. The cyclocondenstion reaction requires a very short time and takes place in good to excellent yields. Furthermore iodotriethylsilane, generated in situ by the reaction of triethylsilane and methyl iodide in the presence of palladium chloride, has been investigated for the synthesis of 1,4‐dihydropyridine derivatives. This facile and efficient method affords high yields for the preparation of 1,4‐dihydropyridines at room temperature and short reaction times. Copyright © 2009 John Wiley & Sons, Ltd.
Determination of enalapril maleate and atenolol in their pharmaceutical products and in biological fluids by flow‐injection chemiluminescence
Authors: Al‐arfaj Nawal A. , Al‐Abdulkareem Eman A. , Aly Fatma A. 
Published: May 2009

AbstractA chemiluminescent method using flow injection (FI) was investigated for rapid and sensitive determination of enalapril maleate and atenolol, which are used in the treatment of hypertension. The method is based on the sensitizing effect of these drugs on the Ce(IV)–sulfite reaction. The different experimental parameters affecting the chemiluminescence (CL) intensity were carefully studied and incorporated into the procedure. The method permitted the determination of 0.01–3.0 µg mL−1 of enalapril maleate in bulk form with correlation coefficient r = 0.99993, lower limit of detection (LOD) 0.0025 µg mL−1 (S/N = 2) and lower limit of quantitation (LOQ) 0.01 µg mL−1. The linearity range of atenolol in bulk form was 0.01–2.0 µg mL−1 (r = 0.99989) with LOD of 0.0003 µg mL−1 (S/N = 2) and LOQ of 0.01 µg mL−1. In biological fluids the linearity range of enalapril maleate was 0.1–2.0 µg mL−1 in both urine and serum, and for atenolol the linearity range was 0.1–1.0 µg mL−1 in both urine and serum. The method was also applied to the determination of the drugs in their pharmaceutical preparations. Copyright © 2009 John Wiley & Sons, Ltd.
Reactive oxygen species and peroxisomes: Struggling for balance
Authors: Bonekamp Nina A. , Völkl Alfred , Fahimi H. Dariush , Schrader Michael 
Published: May 2009

AbstractReactive oxygen species (ROS) can surely be considered as multifunctional biofactors within the cell. They are known to participate in regular cell functions, for example, as signal mediators, but overproduction under oxidative stress conditions leads to deleterious cellular effects, cell death and diverse pathological conditions. Peroxisomal function has long been linked to oxygen metabolism due to the high concentration of H2O2‐generating oxidases in peroxisomes and their set of antioxidant enzymes, especially catalase. Still, mitochondria have been very much placed in the centre of ROS metabolism and oxidative stress. This review discusses novel findings concerning the relationship between ROS and peroxisomes, as they revealed to be a key player in the dynamic spin of ROS metabolism and oxidative injury. An overview of ROS generating enzymes as well as their antioxidant counterparts will be given, exemplifying the precise fine‐tuning between the opposing systems. Various conditions in which the balance between generation and scavenging of ROS in peroxisomes is perturbed, for example, exogenous manipulation, ageing and peroxisomal disorders, are addressed. Furthermore, peroxisome‐derived oxidative stress and its effect on mitochondria (and vice versa) are discussed, highlighting the close interrelationship of both organelles. © 2009 International Union of Biochemistry and Molecular Biology, Inc.
Review of the mechanism of processive actin filament elongation by formins
Authors: Paul Aditya S. , Pollard Thomas D. 
Published: May 2009

AbstractWe review recent structural and biophysical studies of the mechanism of action of formins, proteins that direct the assembly of unbranched actin filaments for cytokinetic contractile rings and other cellular structures. Formins use free actin monomers to nucleate filaments and then remain bound to the barbed ends of these filaments as they elongate. In addition to variable regulatory domains, formins typically have formin homology 1 (FH1) and formin homology 2 (FH2) domains. FH1 domains have multiple binding sites for profilin, an abundant actin monomer binding protein. FH2 homodimers encircle the barbed end of a filament. Most FH2 domains inhibit actin filament elongation, but FH1 domains concentrate multiple profilin‐actin complexes near the end of the filament. FH1 domains transfer actin very rapidly onto the barbed end of the filament, allowing elongation at rates that exceed the rate of elongation by the addition of free actin monomers diffusing in solution. Binding of actin to the end of the filament provides the energy for the highly processive movement of the FH2 as a filament adds thousands of actin subunits. These biophysical insights provide the context to understand how formins contribute to actin assembly in cells. Cell Motil. Cytoskeleton 2009. © 2009 Wiley‐Liss, Inc.