bluuebunny/crossref_metadata_2025_split huggingface dataset:
Some highlights of research on aging with invertebrates, 2009
Authors: Partridge Linda 
Published: June 2009

SummaryThis annual review focuses on invertebrate model organisms, which shed light on new mechanisms in aging and provide excellent systems for both genome‐wide and in‐depth analysis. This year, protein interaction networks have been used in a new bioinformatic approach to identify novel genes that extend replicative lifespan in yeast. In an extended approach, using a new, human protein interaction network, information from the invertebrates was used to identify new, candidate genes for lifespan extension and their orthologues were validated in the nematode Caenorhabditis elegans. Chemosensation of diffusible substances from bacteria has been shown to limit lifespan in C. elegans, while a systematic study of the different methods used to implement dietary restriction in the worm has shown that they involve mechanisms that are partially distinct and partially overlapping, providing important clarification for addressing whether or not they are conserved in other organisms. A new theoretical model for the evolution of rejuvenating cell division has shown that asymmetrical division for either cell size or for damaged cell constituents results in increased fitness for most realistic levels of cellular protein damage. Work on aging‐related disease has both refined our understanding of the mechanisms underlying one route to the development of Parkinson’s disease and has revealed that in worms, as in mice, dietary restriction is protective against cellular proteotoxicity. Two systematic studies genetically manipulating the superoxide dismutases of C. elegans support the idea that damage from superoxide plays little or no role in aging in this organism, and have prompted discussion of other kinds of damage and other kinds of mechanisms for producing aging‐related decline in function.
Autocrine amplification loop in statin‐induced apoptosis of human melanoma cells
Authors: Minichsdorfer C , Hohenegger M 
Published: June 2009

Background and purpose:  Beside their cholesterol lowering effect, statins exert pleiotropic effects, which include anti‐inflammatory, immunosuppressive and anti‐proliferative actions. In higher concentrations, statins trigger apoptosis in primary cells and tumour cells. In particular, melanoma cells have been found to be susceptible to statin‐induced apoptosis, although only after longer incubation times. The molecular mechanisms behind this delayed drug‐induced apoptosis are still unclear.Experimental approach:  The human melanoma A375 and 518A2 cell lines were exposed to various statins in a time‐dependent and dose‐dependent manner, and indicators of apoptosis, caspase activity and individual apoptotic pathways were analysed for 3‐hydroxy‐3‐methylglutaryl‐coenzyme A reductase dependent and independent effects.Key results:  Kinetic analysis of statin‐induced apoptosis revealed an apoptotic burst for exposure times longer than 24 h. While the extrinsic pathway was not activated within 24 h, longer incubation times corroborated amplification of the mitochondrial pathway with significant activation of caspase 8. Continuous refreshing of the simvastatin‐containing medium abrogated the mitochondrial amplification loop via caspase 8. Moreover, conditional medium, supplemented with mevalonic acid in order to nullify a possible contamination by statins, significantly triggered caspase 8 activity. Fas ligand was excluded as a possible candidate to account for the statin‐induced autocrine amplification loop.Conclusions and implications:  Simvastatin and atorvastatin are capable of triggering an ‘autocrine’ suicide factor, which amplifies apoptosis via the extrinsic pathway in human melanoma cells. This pro‐apoptotic stimulus implies possible therapeutic potential and may guide feasibility for more potent statins in anti‐cancer strategies.
A new class of organic nitrates: investigations on bioactivation, tolerance and cross‐tolerance phenomena
Authors: Schuhmacher S , Schulz E , Oelze M , König A , Roegler C , Lange K , Sydow L , Kawamoto T , Wenzel P , Münzel T , Lehmann J , Daiber A 
Published: June 2009

Background and purpose:  The chronic use of organic nitrates is limited by serious side effects including oxidative stress, nitrate tolerance and/or endothelial dysfunction. The side effects and potency of nitroglycerine depend on mitochondrial aldehyde dehydrogenase (ALDH‐2). We sought to determine whether this concept can be extended to a new class of organic nitrates with amino moieties (aminoalkyl nitrates).Experimental approach:  Vasodilator potency of the organic nitrates, in vitro tolerance and in vivo tolerance (after continuous infusion for 3 days) were assessed in wild‐type and ALDH‐2 knockout mice by isometric tension studies. Mitochondrial oxidative stress was analysed by L‐012‐dependent chemiluminescence and protein tyrosine nitration.Key results:  Aminoethyl nitrate (AEN) showed an almost similar potency to glyceryl trinitrate (GTN), even though it is only a mononitrate. AEN‐dependent vasodilatation was mediated by cGMP and nitric oxide. In contrast to triethanolamine trinitrate (TEAN) and GTN, AEN bioactivation did not depend on ALDH‐2 and caused no in vitro tolerance. In vivo treatment with TEAN and GTN, but not with AEN, induced cross‐tolerance to acetylcholine (ACh)‐dependent and GTN‐dependent relaxation. Although all nitrates tested induced tolerance to themselves, only TEAN and GTN significantly increased mitochondrial oxidative stress in vitro and in vivo.Conclusions and implications:  The present results demonstrate that not all high potency nitrates are bioactivated by ALDH‐2 and that high potency of a given nitrate is not necessarily associated with induction of oxidative stress or nitrate tolerance. Obviously, there are distinct pathways for bioactivation of organic nitrates, which for AEN may involve xanthine oxidoreductase rather than P450 enzymes.
Osteoblasts play key roles in the mechanisms of action of strontium ranelate
Authors: Brennan TC , Rybchyn MS , Green W , Atwa S , Conigrave AD , Mason RS 
Published: June 2009

Background and purpose:  Strontium ranelate reduces fracture risk in postmenopausal women with osteoporosis. Evidence from non‐clinical studies and analyses of bone markers in phase III trials indicate that this is due to an increase in osteoblast formation and a decrease of osteoclastic resorption. The aim of this work was to investigate, in human cells, the mechanisms by which strontium ranelate is able to influence the activities of osteoblasts and osteoclasts.Experimental approach:  Human primary osteoblasts were used to examine effects of strontium ranelate on replication (thymidine incorporation), differentiation (Runx2 and alkaline phosphatase) and cell survival (cell counts and caspase activity). Osteoprotegerin (OPG) was measured by quantitative reverse transcription PCR (qRT‐PCR) and elisa and receptor activator of NFκB ligand (RANKL) by qRT‐PCR and Western blot. As strontium ranelate has been proposed as an agonist of the calcium‐sensing receptor (CaSR), the involvement of CaSR in the effects of strontium ranelate on OPG and RANKL expression, and cell replication was examined using siRNA.Key results:  Strontium ranelate increased mRNA and protein levels of OPG and suppressed those of RANKL. Strontium ranelate also stimulated osteoblast replication and differentiation and increased cell survival under stress. Knocking down CaSR suppressed strontium ranelate‐induced stimulation of OPG mRNA, reduction of RANKL mRNA, and increase in replication, indicating the involvement of CaSR in these responses.Conclusions and implications:  Our results demonstrate that osteoblasts play a key role in the mechanism of action of the anti‐fracture agent, strontium ranelate by mediating both its anabolic and anti‐resorptive actions, at least in part, via activation of CaSR.
Working Wetland Potential: An index to guide the sustainable development of African wetlands
Authors: McCartney Matthew P. , Houghton‐Carr Helen A. 
Published: June 2009

AbstractPast experience shows that inappropriate agricultural development in wetlands can undermine sustainability and may have profound social and economic repercussions for people dependent on the range of ecosystem services provided by those wetlands. Nonetheless, there is escalating pressure to expand agriculture within wetlands due to increasing population, in conjunction with efforts to increase food security. This paper describes the development of a semi‐analytical framework for identifying, organizing and analyzing the complex factors that link people, agriculture and wetland ecosystems — an index of Working Wetland Potential (WWP). The method is based on a form of multi‐criteria analysis that integrates biophysical and socio‐economic aspects of wetland utilization. The WWP index emerges from the aggregation of two values: the first arising from an appraisal of both the biophysical and socio‐economic suitability of using the wetland for agriculture; and the second resulting from an assessment of the possible hazards, in relation to both social welfare and the ecological character of the wetland. Hence, the approach provides a way to explicitly integrate biophysical and social aspects of wetland utilization in a single index to enable an initial assessment of the suitability of using a wetland for agriculture. Results from three contrasting wetlands in sub‐Saharan Africa are presented.
Agricultural policies and the emergence of cotton as the dominant crop in northern Côte d’Ivoire: Historical overview and current outlook
Authors: Ajayi Oluyede Clifford , Akinnifesi Festus K. , Sileshi Gudeta , Ajayi Adeola O. 
Published: June 2009

AbstractIn most of sub‐Saharan Africa, where the agricultural sector experiences dismal performance and is characterized by a gloomy picture, the cotton sub‐sector in Côte d’Ivoire is often mentioned as a “success story” given the spectacular rise in the quantity of cotton production and the profile of the crop within the farming system. What are the historical and political antecedents of the development of cotton and the factors responsible for the feat accomplished in the midst of general failures in the same continent? To what extent can cotton be regarded as a “success story” and, what lessons can be drawn for agricultural development strategies based on the Ivorian case study? This paper traces the historical and socio‐political background of cotton development in Côte d’Ivoire and identifies key policy and institutional interventions that have influenced the rise of cotton production and its emergence as the dominant crop in the farming systems of the country. Four stages in Ivorian cotton development are identified: planning, take off, crisis and the renaissance phases. The study demonstrates how a combination of good planning, technological advancement and appropriate policy and institutional conditions have contributed significantly to the rise of cotton production and its influence on the agricultural economy of northern Côte d’Ivoire. The study also highlights how the sustainability of agricultural development has been impacted by domestic and international policies and political events over which smallholder farm families have little control, and can at best only respond to. Important questions about cotton development in Côte d'Ivoire are raised that need to be answered before the program can be categorized conclusively as a success story. The study shows that there are no quick fixes to agricultural development in the sub‐region. Rather, good planning and putting the necessary building blocks in place are important prerequisites. It is recommended that agricultural development efforts in the continent take cognizance of the complexity of the sector and address the inter‐relationships that exist among the technical, policy, market and institutional factors that combine individually and collectively to influence African agriculture.
Property rights and governance of Africa's rangelands: A policy overview
Authors: Mwangi Esther 
Published: June 2009

AbstractRecent efforts at securing property rights in dryland Africa have generally involved several interrelated processes such as legal and policy reforms that recognize and strengthen customary rights or the seasonal rights of pastoralists, and the decentralization of land allocation and administration to lower governance levels. These solutions are in turn beset by new problems, key among them are establishing norms for local participation in decision making, preventing manipulation and capture by elites, lack of accountability of local level institutions and authorities, and the onset of a new generation of resource user conflicts. Increasing avenues through which dialogue and communication can occur among policy actors (including local communities) in order to mobilize multiple experiences, information, and to manage power relationships — a collaborative approach to policy governance — is one way of approaching the complexity paradox. This is anticipated to provide opportunity for learning, innovation and adaptability.
The History of Dialysis: The Wonderful Apparatus of John Jacob Abel Called the “Artificial Kidney”
Authors: Eknoyan Garabed 
Published: June 2009

AbstractHemodialysis, which now provides life‐saving therapy to millions of individuals, began as an exploratory attempt to sustain the lives of selected patients in the 1950s. That was a century after the formulation of the concept and determination of the laws governing dialysis. The first step in the translation of the laboratory principles of dialysis to living animals was the “vividiffusion” apparatus developed by John Jacob Abel (1859–1938), dubbed the “artificial kidney” in the August 11, 1913 issue ofThe Timesof London reporting the demonstration of vividiffusion by Abel at University College. The detailed article in the January 18, 1914 of theNew York Times, reproduced here, is based on the subsequent medical reports published by Abel et al. Tentative attempts of human dialysis in the decade that followed based on the vividiffusion apparatus of Abel and his materials (collodion, hirudin, and glass) met with failure and had to be abandoned. Practical dialysis became possible in the 1940s and thereafter after cellophane, heparin, and teflon became available. Abel worked in an age of great progress and experimental work in the basic sciences that laid the foundations of science‐driven medicine. It was a “Heroic Age of Medicine,” when medical discoveries and communicating them to the public were assuming increasing importance. This article provides the cultural, social, scientific, and medical background in which Abel worked, developed and reported his wonderful apparatus called the “artificial kidney.”
Beyond The Current Paradigm: Recent Advances in The Understanding of Sodium Handling – Guest Editors: Stanley Shaldon and Joerg Vienken: Salt, the Neglected Silent Killer
Authors: Shaldon Stanley , Vienken Joerg 
Published: June 2009

AbstractA diet high in salt (sodium chloride) is considered to promote a series of pathological sequaelae. Despite increasing scientific evidence, which supports the notion that reducing salt intake has positive long‐term effects, citizens from the Western Hemisphere consume more, not less salt. Changes in lifestyle of modern societies associated with an increased consumption of “fast food” contribute to this development leading to the “disease of the good life” which involves hypertension, cardiovascular events, and even inflammatory effects. By contrast, consuming diets with reduced salt content are associated with a smaller shift of body fluids from the interstitial into the intravascular space, less antihypertensive medication, a reduced asymmetric dimethylarginine (ADMA) production and, after the generation TGFβ‐mRNA, to a lower mitogen‐activated protein kinases (MAPK) activation. Therefore, the recommendation of the clinical practice guidelines for dialysis [Depner et al. (14)] (as well as numerous other guidelines) to reduce salt intake is not a surprise.
ASDIN: Antibiotic Prophylaxis: Is it Needed for Dialysis Access Procedures?
Authors: Salman Loay , Asif Arif 
Published: June 2009

AbstractAntibiotic prophylaxis has been employed to reduce the risk of infection. Many reports have documented the role of prophylactic antibiotics on the subsequent development of infection in patients undergoing surgical as well as a variety of percutaneous interventions including cardiac, vascular, biliary, genitourinary, and drainage of fluid collections. While prophylactic antibiotics can be critically important for certain procedures, their use can be associated with allergic reactions (including anaphylaxis), development of bacterial resistance, and increased costs of medical care. In this analysis, we report the incidence of clinical infection following minimally invasive interventions for dialysis access procedures. Hemodialysis (HD) and peritoneal dialysis (PD) patients undergoing consecutive percutaneous interventions (n = 3162) for HD and PD access were included in this study. Procedure‐related clinical infection was defined as the presence of fever/chills, tenderness, erythema, swelling within 72 hours postprocedure. The procedures included percutaneous balloon angioplasty (arterial and venous) [n = 2078 (AVF = 1310; AVG = 768)], venography for vascular mapping (n = 110), endovascular stent insertion (n = 26), intravascular coil placement (n = 31), thrombectomy for an arteriovenous fistula (n = 106), thrombectomy for an arteriovenous graft (n = 110), tunneled hemodialysis catheter (TDC) insertion and exchange (n = 283), TDC removal (n = 160), and insertion of accidentally extruded TDC through the same exit site (n = 9). There were 260 peritoneal dialysis catheter insertions and 15 repositioning procedures. Only patients undergoing TDC insertion for accidentally extruded catheter and PD catheter placement received antibiotic prophylaxis within 1–2 hours before the procedure. Extruded TDC received 1 g of cefazolin while PD catheter insertion had 1 g of intravenous vancomycin. Povidone iodine was used for skin antisepsis in all cases. One patient (0.04%) postangioplasty and one patient (0.3%) after tunneled catheter placement developed clinical infection manifested by fever, chills, and malaise within 24 hours of the procedure. Both required hospitalization. Patient with angioplasty was a diabetic with an arteriovenous graft while TDC insertion was performed in a patient with advanced HIV. Percutaneous dialysis access procedure infections are generally low and might not warrant routine administration of antibiotic prophylaxis for all cases except for PD catheters and accidentally extruded TDC.
Red Blood Cell Damage from Extracorporeal Circulation in Hemodialysis
Authors: Polaschegg Hans‐Dietrich 
Published: June 2009

AbstractBlood damage is an unavoidable side effect of extracorporeal circulation. The effects of blood damage on patients’ hematocrit and erythropoietin requirement as well as other potential side effects have not been studied for uneventful treatments. Comparing long nocturnal dialysis with regular 4‐hour, three times per week dialysis allows for the conclusion that the influence of blood damage caused by extracorporeal circulation is small compared with biochemical effects. Acute hemolysis is one of the few remaining mechanical problems of dialysis. Acute hemolysis is caused by obstructions within the extracorporeal circuit caused by manufacturing errors, kinking of blood tubing or user errors, or by a combination of excessive flow and improper cannula or catheter dimensions. The risk of acute hemolysis can be further reduced by industrial quality control, better design of dialysis equipment, and hemodialysis machine control. Adverse effects caused by chronic mechanical hemolysis need to be studied.
Modeling Corn Ethanol and Climate
Authors: Plevin Richard J. 
Published: June 2009

SummaryNew fuel regulations based on life cycle greenhouse gas (GHG) emissions have focused renewed attention on life cycle models of biofuels. The BESS model estimates 25% lower life cycle GHG emissions for corn ethanol than does the well‐known GREET model, which raises questions about which model is more accurate. I develop a life cycle metamodel to compare the GREET and BESS models in detail and to explain why the results from these models diverge. I find two main reasons for the divergence: (1) BESS models a more efficient biorefinery than is modeled in the cases to which its results have been compared, and (2) in several instances BESS fails to properly count upstream emissions. Adjustments to BESS to account for these differences raise the estimated global warming intensity (not including land use change) of the corn ethanol pathway considered in that model from 45 to 61 g CO2e MJ−1. Adjusting GREET to use BESS's biorefinery performance and coproduct credit assumptions reduces the GREET estimate from 64 to 61 g CO2e MJ−1. Although this analysis explains the gap between the two models, both models would be improved with better data on corn production practices and by better treatment of agricultural inputs.
Disease‐Specific, Versus Standard, Nutritional Support for the Treatment of Pressure Ulcers in Institutionalized Older Adults: A Randomized Controlled Trial
Authors: Cereda Emanuele , Gini Anna , Pedrolli Carlo , Vanotti Alfredo 
Published: June 2009

OBJECTIVES: To investigate whether a disease‐specific nutritional approach is more beneficial than a standard dietary approach to the healing of pressure ulcers (PUs) in institutionalized elderly patients.DESIGN: Twelve‐week follow‐up randomized controlled trial (RCT).SETTING: Four long‐term care facilities in the province of Como, Italy.PARTICIPANTS: Twenty‐eight elderly subjects with Stage II, III, and IV PUs of recent onset (<1‐month history).INTERVENTION: All 28 patients received 30 kcal/kg per day nutritional support; of these, 15 received standard nutrition (hospital diet or standard enteral formula; 16% calories from protein), whereas 13 were administered a disease‐specific nutrition treatment consisting of the standard diet plus a 400‐mL oral supplement or specific enteral formula enriched with protein (20% of the total calories), arginine, zinc, and vitamin C (P<.001 for all nutrients vs control).MEASUREMENTS: Ulcer healing was evaluated using the Pressure Ulcer Scale for Healing (PUSH; 0=complete healing, 17=greatest severity) tool and area measurement (mm2 and %).RESULTS: The sampled groups were well matched for age, sex, nutritional status, oral intake, type of feeding, and ulcer severity. After 12 weeks, both groups showed significant improvement (P<.001). The treatment produced a higher rate of healing, the PUSH score revealing a significant difference at Week 12 (−6.1±2.7 vs −3.3±2.4; P<.05) and the reduction in ulcer surface area significantly higher in the treated patients already by Week 8 (−1,140.9±669.2 mm2 vs −571.7±391.3 mm2; P<.05 and ∼57% vs ∼33%; P<.02).CONCLUSION: The rate of PU healing appears to accelerate when a nutrition formula enriched with protein, arginine, zinc, and vitamin C is administered, making such a formula preferable to a standardized one, but the present data require further confirmation by high‐quality RCTs conducted on a larger scale.