bluuebunny/crossref_metadata_2025 huggingface dataset:
Potassium carrier TRH1 is required for auxin transport in Arabidopsis roots
Authors: Vicente‐Agullo Francisco , Rigas Stamatis , Desbrosses Guilhem , Dolan Liam , Hatzopoulos Polydefkis , Grabov Alexander
Published: December 2004

Disruption of the TRH1 potassium transporter impairs root hair development in Arabidopsis, and also affects root gravitropic behaviour. Rescue of these morphological defects by exogenous auxin indicates a link between TRH1 activity and auxin transport. In agreement with this hypothesis, the rate of auxin translocation from shoots to roots and efflux of [3H]IAA in isolated root segments were reduced in the trh1 mutant, but efflux of radiolabelled auxin was accelerated in yeast cells transformed with the TRH1 gene. In roots, ProTRH1:GUS expression was localized to the root cap cells which are known to be the sites of gravity perception and are central for the redistribution of auxin fluxes. Consistent with these findings, auxin‐dependent DR5:GUS promoter‐reporter construct was misexpressed in the trh1 mutant indicating that partial block of auxin transport through the root cap is associated with upstream accumulation of the phytohormone in protoxylem cells. When [K+] in the medium was reduced from 20 to 0.1 mm, wild type roots showed mild agravitropic phenotype and DR5:GUS misexpression in stelar cells. This pattern of response to low external [K+] was also affected by trh1 mutation. We conclude that the TRH1 carrier is an important part of auxin transport system in Arabidopsis roots.
A subset of hypersensitive response marker genes, includingHSR203J, is the downstream target of a spermine signal transduction pathway in tobacco
Authors: Takahashi Yoshihiro , Uehara Yukiko , Berberich Thomas , Ito Akiko , Saitoh Hiromasa , Miyazaki Atsushi , Terauchi Ryohei , Kusano Tomonobu
Published: December 2004

A cellular signal transduction pathway induced by the polyamine, spermine (Spm), and transmitted by mitochondrial dysfunction is proposed in tobacco. In this investigation, we further resolve the pathway by identifying a subset of hypersensitive response (HR) marker genes as downstream components. In a previous report, we identified harpin‐induced 1 (HIN1) and two closely related genes as responsive to Spm. Other HR marker genes,HSR203J,HMGR,HSR201, andHSR515, are also Spm‐responsive. Induction of these HR marker genes, includingHIN1, by Spm was suppressed by pre‐treatment with antioxidants, calcium channel blockers, inhibitor of mitochondrial permeability transition pore openings, and blockers of amine oxidase/polyamine oxidase. Such quenching is also observed for Spm‐induced activation of two mitogen‐activated protein kinases (MAPKs), salicylic acid‐induced protein kinase (SIPK), and wound‐induced protein kinase (WIPK), and upregulation of theWIPKgene, suggesting that all these components are part of the same signaling pathway. Furthermore, gain‐of‐function and loss‐of‐function studies on MAPK cascade members reveal that the expression of Spm‐induced HR marker genes varies with respect to involvement of SIPK/WIPK activation.
WRINKLED1 encodes an AP2/EREB domain protein involved in the control of storage compound biosynthesis in Arabidopsis
Authors: Cernac Alex , Benning Christoph
Published: December 2004

The accumulation of storage compounds during seed development ensures the survival of the young seedling, and also provides nutrition to humans and animals in the form of foods and feeds. The putative AP2/EREBP transcription factor WRINKLED1 (WRI1) is involved in the regulation of seed storage metabolism in Arabidopsis. A splicing mutant allele, wri1‐1, caused the reduction of seed oil accumulation. Glycolysis was compromised in this mutant, rendering developing embryos unable to efficiently convert sucrose into precursors of triacylglycerol biosynthesis. Expression of the WRINKLED1 cDNA under the control of the cauliflower mosaic virus 35S‐promoter led to increased seed oil content. Moreover, the ectopic expression of the WRINKLED1 cDNA caused the accumulation of triacylglycerols in developing seedlings. This effect depended upon the presence of glucose in the growth medium or other sugars readily metabolized to glucose. Oil‐accumulating seedlings showed aberrant development consistent with a prolonged embryonic state.
Outbreak of West Nile virus causing severe neurological involvement in children, Nuba Mountains, Sudan, 2002
Authors: Depoortere Evelyn , Kavle Justine , Keus Kees , Zeller Hervé , Murri Séverine , Legros Dominique
Published: December 2004

An atypical outbreak of West Nile virus (WNV) occurred in Ngorban County, South Kordophan, Sudan, from May to August 2002. We investigated the epidemic and conducted a case–control study in the village of Limon. Blood samples were obtained for cases and controls. Patients with obvious sequelae underwent cerebrospinal fluid (CSF) sampling as well. We used enzyme‐linked immunosorbent assay (ELISA) and neutralization tests for laboratory diagnosis and identified 31 cases with encephalitis, four of whom died. Median age was 36 months. Bivariate analysis did not reveal any significant association with the risk factors investigated. Laboratory analysis confirmed presence of IgM antibodies caused by WNV in eight of 13 cases, indicative of recent viral infection. The unique aspects of the WNW outbreak in Sudan, i.e. disease occurrence solely among children and the clinical domination of encephalitis, involving severe neurological sequelae, demonstrate the continuing evolution of WNV virulence. The spread of such a virus to other countries or continents cannot be excluded.
Quantitative evaluation of integrated schistosomiasis control: the example of passive case finding in Ghana
Authors: De Vlas Sake J. , Danso‐Appiah Anthony , Van Der Werf Marieke J. , Bosompem Kwabena M. , Habbema J. Dik F.
Published: December 2004

Passive case finding based on adequate diagnosis and treatment of symptomatic individuals with praziquantel by the health care facilities is a minimum requirement for integrated schistosomiasis control. Two field studies were conducted in Ghana to obtain quantifications about the steps in this process: (1) a study of health‐seeking behaviour through interview of individuals with reported schistosomiasis‐related symptoms; (2) a study of the performance of the Ghanaian health system with regard to schistosomiasis case management by presenting clinical scenarios to health workers and collecting information about availability of praziquantel. It appeared that cases of blood in urine (the most typical symptom of Schistosoma haematobium) and blood in stool (the most typical symptom of S. mansoni) have a very small probability of receiving praziquantel (4.4% and 1.4%, respectively) from health facilities. Programmes aimed at making the drug available at all levels of the health care delivery system and encouraging health‐seeking behaviour through health education are not likely to increase these probabilities beyond 30%. This is because many cases with blood in urine do not consider it serious enough to seek health care, and blood in stool usually requires (imperfect) diagnostic testing and referral. We therefore conclude that additional control activities, especially for high‐risk groups, will remain necessary.
Disease control in primary health care: a historical perspective
Authors: Van Balen Harrie
Published: December 2004

The effectiveness of disease control by mobile teams decreased when countries became independent. Early case‐finding and continuity of care require permanently accessible health care facilities where rationalization by professionals and participation of the users are well balanced. The Primary Health Care concept, a plea for this equilibrium, has been discredited by different types of misapplication. Correctly functioning and accessible first line health services, completed by a referral level, are a precondition for effective participation of the users. Where ‘ideal health districts’ cannot be realized, a form of steady exchanges between generalists and the specialists of the referral level has lead to diverse ‘functional districts’.
The practical importance of permanent and semipermanent habitats for controlling aquatic stages of Anopheles gambiae sensu lato mosquitoes: operational observations from a rural town in western Kenya
Authors: Fillinger Ulrike , Sonye George , Killeen Gerry F. , Knols Bart G. J. , Becker Norbert
Published: December 2004

Control of aquatic‐stage Anopheles is one of the oldest and most historically successful interventions to prevent malaria, but it has seen little application in Africa. Consequently, the ecology of immature afrotropical Anopheles has received insufficient attention. We therefore examined the population dynamics of African anopheline and culicine mosquitoes using operationally practicable techniques to examine the relative importance and availability of different larval habitats in an area of perennial malaria transmission in preparation for a pilot‐scale larval control programme. The study was conducted in Mbita, a rural town on the shores of Lake Victoria in Western Kenya, over 20 months. Weekly larval surveys were conducted to identify the availability of stagnant water, habitat characteristics and larval densities. Adult mosquitoes were collected indoors at fortnightly intervals. Availability of aquatic habitats and abundance of mosquito larvae were directly correlated with rainfall. Adult mosquito densities followed similar patterns but with a time‐lag of approximately 1 month. About 70% of all available habitats were man‐made, half of them representing cement‐lined pits. On average, 67% of all aquatic habitats on a given sampling date were colonized by Anopheles larvae, of which all identified morphologically were A. gambiae sensu lato. Natural and artificial habitats were equally productive over the study period and larval densities were positively correlated with presence of tufts of low vegetation and negatively with non‐matted algal content. The permanence of a habitat had no significant influence on larval productivity. We conclude that A. gambiae is broadly distributed across a variety of habitat types, regardless of permanence. All potential breeding sites need to be considered as sources of malaria risk at any time of the year and exhaustively targeted in any larval control intervention.
Clinical microbicide research: an overview
Authors: Damme Lut Van
Published: December 2004

At the end of 2003, 42 million people were HIV infected and the epidemic continues to spread, despite the availability and effectiveness of male condoms. For many women negotiating condom use is not feasible. Therefore there is an urgent need for a female controlled method for HIV prevention. This article gives an overview of the clinical research done with microbicides, chemicals with the potential to prevent an HIV infection. In the 1990s most research was done with spermicides, mainly nonoxynol‐9. Since the results of the COL‐1492 trial became available, new products were evaluated and some of them are now in phase III trials.
Exploring 30 years of malaria case data in KwaZulu‐Natal, South Africa: Part I. The impact of climatic factors
Authors: Craig M. H. , Kleinschmidt I. , Nawn J. B. , Le Sueur D. , Sharp B. L.
Published: December 2004

Large parts of Africa are prone to malaria epidemics. Advance epidemic warning would give health services an opportunity to prepare. Because malaria transmission is largely limited by climate, climate‐based epidemic warning systems are a real possibility. To develop and test such a system, good long‐term malaria and climate data are needed. In KwaZulu‐Natal (KZN), South Africa, 30 years of confirmed malaria case data provide a unique opportunity to examine short‐ and long‐term trends. We analysed seasonal case totals and seasonal changes in cases (both log‐transformed) against a range of climatic indicators obtained from three weather stations in the highest malaria incidence districts, using linear regression analysis. Seasonal changes in case numbers (delta log cases, dlc) were significantly associated with several climate variables. The two most significant ones were mean maximum daily temperatures from January to October of the preceding season (n = 30,r2 = 0.364,P = 0.0004) and total rainfall during the current summer months of November–March (n = 30,r2 = 0.282,P = 0.003). These two variables, when entered into the same regression model, together explained 49.7% of the total variation in dlc. We found no evidence of association between case totals and climate. In KZN, where malaria control operations are intense, climate appears to drive the interannual variation of malaria incidence, but not its overall level. The accompanying paper provides evidence that overall levels are associated with non‐climatic factors such as drug resistance and possibly HIV prevalence.
Fake antimalarials in Southeast Asia are a major impediment to malaria control: multinational cross‐sectional survey on the prevalence of fake antimalarials
Authors: Dondorp A. M. , Newton P. N. , Mayxay M. , Van Damme W. , Smithuis F. M. , Yeung S. , Petit A. , Lynam A. J. , Johnson A. , Hien T. T. , McGready R. , Farrar J. J. , Looareesuwan S. , Day N. P. J. , Green M. D. , White N. J.
Published: December 2004

Objective  To assess the prevalence of counterfeit antimalarial drugs in Southeast (SE) Asia.

Design  Cross‐sectional survey.

Setting  Pharmacies and shops selling antimalarial drugs in Myanmar (Burma), Lao PDR, Vietnam, Cambodia and Thailand.

Main outcome measures  Proportion of artemisinin derivatives or mefloquine containing drugs of substandard quality.

Results  Of the 188 tablet packs purchased which were labelled as ‘artesunate’ 53% did not contain any artesunate. All counterfeit artesunate tablets were labelled as manufactured by ‘Guilin Pharma’, and refinements of the fake blisterpacks made them often hard to distinguish from their genuine counterparts. No other artemisinin derivatives were found to be counterfeited. Of the 44 mefloquine samples, 9% contained <10% of the expected amount of active ingredient.

Conclusions  An alarmingly high proportion of antimalarial drugs bought in pharmacies and shops in mainland SE Asia are counterfeit, and the problem has increased significantly compared with our previous survey in 1999–2000. This is a serious threat to public health in the region.
Understanding of and attitudes to xenotransplantation: a survey among Italian university students
Authors: Bona Manuela De , Canova Daniele , Rumiati Rino , Russo Francesco Paolo , Ermani Mario , Ancona Ermanno , Naccarato Remo , Burra Patrizia
Published: December 2004

Abstract: Xenotransplantation is currently at the experimental stages on animal models and many problems still have to be overcome in the biomedical, immunological and ethical fields. Moreover, people's attitudes to xenotransplantation vary: surveys among intensive‐care staff have revealed negative opinions, while the general public and students seem to be more positive. Little is known about the influence of schooling and the choice of university faculty on attitudes to xenotransplantation. The aims of this study were: (i) to evaluate university students’ attitudes to xenotransplantation; (ii) to investigate any socio‐demographic, religious and educational determinants behind students’ opinions on xenotransplantation. University undergraduates on five different courses were surveyed at Padua University. A 24‐item questionnaire was distributed to students at the end of lectures and completed anonymously immediately after its distribution. No information was given to students beforehand. Statistical analysis: chi‐squared, Pearson's test; P‐values <0.05 were considered significant. A total of 585 of 602 (97.2%) students completed the questionnaire (132 males, 453 females, mean age 20.4, range 19 to 43 yr). They were on courses in Medicine (33.85%), Agriculture (5.98%), Veterinary Medicine (11.45%), Psychology (18.46%) and Educational Sciences (30.26%). As for their previous schooling, they came from classical or scientific high school (58.3%), technical college (14.7%), language college (6.3%), teacher training college (11.9%) or others (8.8%). Concerning their religious beliefs, 83% were Catholics, and 56.2% defined themselves as practising Catholics. Eighty‐eight percentage of the students knew of the possibility of animal organs being transplanted into humans and 77.9% of them approved of this idea. When grouped according to gender and education, a higher proportion of students approving of xenotransplantation were male (P = 0.017) and had attended classical or scientific high school (P = 0.011). Disapproval for moral, ethical or religious reasons was higher among practising than among non‐practising Catholics; the latter rejected xenotransplantation more for immunological and infectious reasons (P = 0.014). As for the type of university course, a higher proportion of students approving of xenotransplantation attended science courses (Veterinary Medicine, Agriculture and Medicine vs. Educational Sciences and Psychology) (P = 0.013). University students generally approved of xenotransplantation. Male gender and a high‐school education were associated with a greater acceptance of xenotransplantation. Practising vs. non‐practising Catholics reported significantly different reasons for any disapproval of xenotransplantation. The choice of a science rather than an arts faculty at university was more strongly associated with a positive opinion on xenotransplantation.
Polymorphism of the human platelet antigen‐5 system is a risk factor for occlusive vascular complications in patients with sickle cell anemia
Authors: Castro V. , Alberto F. L. , Costa R. N. P. , Lepikson‐Neto J. , Gualandro S. F. M. , Figueiredo M. S. , Annichino‐Bizzacchi J. M. , Saad S. T. O. , Costa F. F.
Published: December 2004

Background Polymorphisms of platelet membrane glycoproteins such as human platelet antigen (HPA)‐1b, HPA‐2b, the ‐5T/C Kozak sequence and C807T have been described as risk factors for vascular disease. Vaso‐occlusion episodes are a common feature of sickle cell anaemia (SCA), leading to complications such as stroke, acute chest syndrome, avascular head femur necrosis and priapism. Complex interactions are involved in vaso‐occlusion, and activated platelets may play an important role. These data raised the question of whether platelet polymorphisms could be implicated in occlusive vascular complications (OVC) of SCA.

Materials and Methods In this study, 97 patients with SCA were analysed in two groups: 34 patients presenting with OVC (SCA‐VC) and 63 without these complications (SCA‐N). The distribution of the HPA‐1, ‐2 and ‐5 systems, as well as C807T dimorphism and ‐5T/C Kozak sequence alleles, was evaluated using DNA‐based methods.

Results Patients of the SCA‐VC group showed a higher frequency of the HPA‐5b allele (0·324) compared with those of the SCA‐N group (0·111) (χ2 = 13·19,P = 0·0002). None of the other polymorphisms, isolated or associated as haplotypes, demonstrated any correlation with the development of OVC in these patients.

Conclusions The findings of this study suggest that the HPA‐5b allele is a genetic risk factor for the development of OVC in patients with SCA. This allele could be explored as a target for the development of new therapeutic approaches.
LU21: a new high‐frequency antigen in the Lutheran blood group system
Authors: Crew V. Karamatic , Poole J. , Banks J. , Reed M. , Daniels G.
Published: December 2004

Background and Objectives  The Lutheran blood group system comprises 18 antigens numbered LU1 to LU20, with two numbers obsolete. Thirteen antigens are of high frequency.

Materials and Methods  Serological tests were performed by conventional methods. The monoclonal antibody‐specific immobilization of erythrocyte antigens (MAIEA) assay was carried out with monoclonal antibodies to Lutheran glycoprotein. All exons of the LU gene were amplified by the polymerase chain reaction (PCR) and directly sequenced from genomic DNA.

Results  A patient was found to have an antibody to a high‐frequency red cell antigen during her second pregnancy. The antibody was shown to be Lutheran‐related and was distinguished from all reported Lutheran antibodies. MAIEA suggested the antibody was defining a novel epitope in domain 1 of the Lu‐glycoprotein. Sequencing of the LU gene revealed a new homozygous single‐point mutation, C282G, in exon 3, encoding an Asp94Glu change in the first domain of the Lu‐glycoprotein.

Conclusions  The antibody detected a new high‐frequency Lutheran antigen, numbered LU21, that appears to result from an Asp94Glu substitution in the first, N‐terminal domain of the Lu‐glycoprotein.
External quality assessment for the detection of blood‐borne viruses in plasma by nucleic acid amplification technology: the first human immunodeficiency virus and hepatitis B virus studies (HIV EQA/1 and HBV EQA/1) and the fifth hepatitis C virus study (HCV EQA/5)
Authors: Pisani G. , Cristiano K. , Saldanha J. , Wirz M. , Bisso G. M. , Mele C. , Gentili G. ,   the EQA Participants
Published: December 2004

Background and Objectives  This External Quality Assessment (EQA) study was aimed at assessing the proficiency of blood centres and blood product manufacturers in detecting, by nucleic acid amplification technology (NAT), the possible contamination of plasma with hepatitis C virus (HCV), human immunodeficiency virus (HIV) and hepatitis B virus (HBV).

Materials and Methods  Three independent panels, one for each virus, were prepared at the Istituto Superiore di Sanità (ISS) by diluting the respective reference preparations. NAT methods used by the EQA participants included polymerase chain reaction (PCR) assays by Roche, transcription‐mediated amplification (TMA) assays by Chiron and in‐house PCR assays.

Results  Forty‐three of the 45 participants (95·6%) in the HCV EQA/5 who used a validated method were consistently able to detect a nominal concentration of 100 IU/ml for all six major genotypes. In the case of the HIV EQA/1, all 35 participants detected the samples containing 1000 IU/ml HIV, while five (14·3%) did not identify the samples containing 100 IU/ml HIV. With respect to the HBV EQA/1, all 16 participants correctly identified the positive samples containing either 1000 IU/ml or 100 IU/ml HBV. No false‐positive results were observed with any of the three panels.

Conclusions  The HCV EQA/5 showed an improved proficiency of laboratories as compared with the HCV EQA/4. In fact, HCV genotypes 1, 2, 3 and 5 were correctly identified in 100% of the assays and genotypes 4 and 6 in 97·8% of the assays. While most of the participants in the HIV EQA/1 showed a good level of proficiency, an excellent performance was shown by all participants in the HBV EQA/1.
Pathogen reduction of buffy coat platelet concentrates using riboflavin and light: comparisons with pathogen‐reduction technology‐treated apheresis platelet products
Authors: Li J. , De Korte D. , Woolum M. D. , Ruane P. H. , Keil S. D. , Lockerbie O. , McLean R. , Goodrich R. P.
Published: December 2004

Background and Objectives  A pathogen‐reduction technology (PRT) system using riboflavin and light has been developed for the treatment of platelet concentrates (PC) obtained by either buffy coat preparation (BCPC) or apheresis procedures (APPC). The aim of this study was to evaluate the effects of the treatment process on in vitro cell quality and on riboflavin conversion in PC.

Materials and Methods  BCPC were prepared with the Compomat G4™ from whole blood which had been stored overnight after collection. APPC were obtained using the TRIMA™ apheresis procedure. Both PC products had been stored for 18–24 h prior to PRT treatment. BCPC and APPC were treated with PRT on day 2 and day 1 of shelf‐life, respectively. The treated PCs were then maintained for an additional 5 days after the PRT treatment. A panel of cell quality assays and high‐performance liquid chromatography (HPLC) analysis were performed.

Results  Cell counts and plasma lactate dehydrogenase (LDH) levels during storage indicated that PRT did not induce significant cell lysis. Acceleration of a decrease in glucose and an increase in lactate was observed for treated PCs, but no significant differences were observed between treated BCPC and APPC. The pH of treated samples remained above 7·0, although was lower than that of the control. Platelet morphology of BCPC and APPC was well preserved. P‐selectin expression indicated significant platelet activation when compared with control PC (BCPC on day 6: 39% vs. 12%; APPC on day 5: 35% vs. 18%). Both P‐selectin expression and microparticle formation were not significantly different between treated BCPC and APPC during storage. The JC‐1 assay also displayed no loss of mitochondria integrity during the storage of treated products. Approximately 20% of riboflavin converted into photoproducts, including lumichrome.

Conclusions  PRT treatment had an effect on the development of the normal platelet storage lesion at a level which seems tolerable for clinical usage.
Concurrent and Across Time Prediction of Young Adolescents’ Social Functioning: The Role of Emotionality and Regulation
Authors: Murphy Bridget C. , Shepard Stephanie A. , Eisenberg Nancy , Fabes Richard A.
Published: December 2004

The social functioning of 64 young adolescents (10‐ to 12‐year olds) was examined in relation to negative emotionality and regulation during early adolescence, as well as two, four, and six years earlier. Young adolescents who were viewed as relatively high in social functioning (i.e., high teacher‐rated school social competence; low mother‐ or father‐rated problem behavior) were generally viewed as relatively low on negative emotionality and high on regulatory abilities during early adolescence as well as two, four, and six years earlier. Furthermore, negative emotionality and regulation during early adolescence, and in some cases at previous time periods, contributed unique variance to the prediction of social functioning during early adolescence. Young adolescents who were consistently low in social functioning across time were higher on negative emotionality and lower on regulation than were young adolescents who were consistently high on social functioning over time.
A Semiparametric Multilevel Survival Model
Authors: Zhang Wenyang , Steele Fiona
Published: December 2004

We propose a semiparametric multilevel survival model for clustered duration data in which the effect of a continuous covariate is represented by an unspecified, possibly non-linear, function. This model makes no distributional assumption about the cluster level random effects. The performance of the method is assessed via Monte Carlo simulations. The model is applied in an analysis of first-birth intervals in Bangladesh to examine period effects in the timing of first births, while allowing for clustering within communities; the analysis reveals a non-linear trend in the first-birth interval over time.
Estimating Catch at Age from Market Sampling Data by Using a Bayesian Hierarchical Model
Authors: Hirst David , Aanes Sondre , Storvik Geir , Huseby Ragnar Bang , Tvete Ingunn Fride
Published: December 2004

The paper develops a Bayesian hierarchical model for estimating the catch at age of cod landed in Norway. The model includes covariate effects such as season and gear, and can also account for the within-boat correlation. The hierarchical structure allows us to account properly for the uncertainty in the estimates.
Period Analysis of Variable Stars by Robust Smoothing
Authors: Oh Hee-Seok , Nychka Doug , Brown Tim , Charbonneau Paul
Published: December 2004

The objective is to estimate the period and the light curve (or periodic function) of a variable star. Previously, several methods have been proposed to estimate the period of a variable star, but they are inaccurate especially when a data set contains outliers. We use a smoothing spline regression to estimate the light curve given a period and then find the period which minimizes the generalized cross-validation (GCV). The GCV method works well, matching an intensive visual examination of a few hundred stars, but the GCV score is still sensitive to outliers. Handling outliers in an automatic way is important when this method is applied in a ‘data mining’ context to a vary large star survey. Therefore, we suggest a robust method which minimizes a robust cross-validation criterion induced by a robust smoothing spline regression. Once the period has been determined, a nonparametric method is used to estimate the light curve. A real example and a simulation study suggest that the robust cross-validation and GCV methods are superior to existing methods.
Chebyshev’s Inequality for Nonparametric Testing with SmallNandαin Microarray Research
Authors: Beasley T. Mark , Page Grier P. , Brand Jaap P. L. , Gadbury Gary L. , Mountz John D. , Allison David B.
Published: December 2004

Microarrays are a powerful new technology that allow for the measurement of the expression of thousands of genes simultaneously. Owing to relatively high costs, sample sizes tend to be quite small. If investigators apply a correction for multiple testing, a very small p-value will be required to declare significance. We use modifications to Chebyshev’s inequality to develop a testing procedure that is nonparametric and yields p-values on the interval [0, 1]. We evaluate its properties via simulation and show that it both holds the type I error rate below nominal levels in almost all conditions and can yield p-values denoting significance even with very small sample sizes and stringent corrections for multiple testing.
Bayesian Analysis of Discrete Time Warranty Data
Authors: Stephens David , Crowder Martin
Published: December 2004

The analysis of warranty claim data, and their use for prediction, has been a topic of active research in recent years. Field data comprising numbers of units returned under guarantee are examined, covering both situations in which the ages of the failed units are known and in which they are not. The latter case poses particular computational problems for likelihood-based methods because of the large number of feasible failure patterns that must be included as contributions to the likelihood function. For prediction of future warranty exposure, which is of central concern to the manufacturer, the Bayesian approach is adopted. For this, Markov chain Monte Carlo methodology is developed.
Activity‐dependent extracellular K+ accumulation in rat optic nerve: the role of glial and axonal Na+ pumps
Authors: Ransom Christopher B. , Ransom Bruce R. , Sontheimer Harald
Published: December 2004

We measured activity‐dependent changes in [K+]o with K+‐selective microelectrodes in adult rat optic nerve, a CNS white matter tract, to investigate the factors responsible for post‐stimulus recovery of [K+]o.

Post‐stimulus recovery of [K+]o followed a double‐exponential time course with an initial, fast time constant, τfast, of 0.9 ± 0.2 s (mean ±s.d.) and a later, slow time constant, τslow, of 4.2 ± 1 s following a 1 s, 100 Hz stimulus. τfast, but not τslow, decreased with increasing activity‐dependent rises in [K+]o. τslow, but not τfast, increased with increasing stimulus duration.

Post‐stimulus recovery of [K+]o was temperature sensitive. The apparent temperature coefficients (Q10, 27–37°C) for the fast and slow components following a 1 s, 100 Hz stimulus were 1.7 and 2.6, respectively.

Post‐stimulus recovery of [K+]o was sensitive to Na+ pump inhibition with 50 μM strophanthidin. Following a 1 s, 100 Hz stimulus, 50 μM strophanthidin increased τfast and τslow by 81 and 464%, respectively. Strophanthidin reduced the temperature sensitivity of post‐stimulus recovery of [K+]o.

Post‐stimulus recovery of [K+]o was minimally affected by the K+ channel blocker Ba2+ (0.2 mm). Following a 10 s, 100 Hz stimulus, 0.2 mm Ba2+ increased τfast and τslow by 24 and 18%, respectively.

Stimulated increases in [K+]o were followed by undershoots of [K+]o. Post‐stimulus undershoot amplitude increased with stimulus duration but was independent of the peak preceding [K+]o increase.

These observations imply that two distinct processes contribute to post‐stimulus recovery of [K+]o in central white matter. The results are compatible with a model of K+ removal that attributes the fast, initial phase of K+ removal to K+ uptake by glial Na+ pumps and the slower, sustained decline to K+ uptake via axonal Na+ pumps.
Calcium‐, voltage‐ and osmotic stress‐sensitive currents in Xenopus oocytes and their relationship to single mechanically gated channels
Authors: Zhang Yong , Hamill Owen P.
Published: December 2004

Patch recordings from Xenopus oocytes indicated that mechanically gated (MG) channels are expressed at a uniform surface density (∼1 channel μm−2) with an estimated > 3 × 106 MG channels per oocyte that could generate microamps of current at ±50 mV.

Removal of external Ca2+ induced a membrane conductance that differed from MG channels in ion selectivity, pharmacology and sensitivity to connexion‐38.

Depolarization to +50 mV activated a Na+‐selective, a Cl−‐selective and a non‐selective conductance. Hyperpolarization to −150 mV activated a non‐selective conductance. None of these conductances appeared to be mediated by MG channels.

Hypotonicity (25 %) failed to evoke any change in membrane conductance in the majority of defolliculated oocytes. Hypertonicity (200 %) evoked a large non‐selective (PK/PCl≈ 1) membrane conductance that was not blocked by 100 μM Gd3+.

Although the above stimuli could activate a variety of whole‐oocyte conductances, including three novel conductances, they did not involve MG channel activation. Possible mechanisms underlying the discrepancy between observed conductances and those anticipated from patch‐clamp studies are discussed.
Review of Combination of Peritoneal Dialysis and Hemodialysis as a Modality of Treatment for End‐stage Renal Disease
Authors:   PD + HD Combination Therapy Study Group
Published: December 2004

Abstract: Because the contribution of residual renal function (RRF) to total solute clearance is often significant in continuous ambulatory peritoneal dialysis (CAPD), loss of RRF over time can lead to inadequate dialysis if appropriate prescription management strategies are not pursued. Additionally, declines in ultrafiltration caused by increases in peritoneal permeability may limit continuation of CAPD therapy. Peritoneal dialysis and hemodialysis (PD + HD) combination therapy (complementary dialysis therapy) is an alternative method. This therapy allows the patient to maintain daily activities, as with CAPD, while undergoing once‐a‐week HD supplements for the insufficient removal of solutes and water. This therapy allows for the continuation of PD without shifting to total HD in PD patients who continue to have uremic symptoms even after individualization of the PD prescription. This treatment option is psychologically more acceptable to patients and may be expected to provide such accompanying beneficial effects as peritoneal resting, improvement of QOL and reduction in medical cost.
Endoplasmic Reticulum‐Localized Amyloid β‐Peptide is Degraded in the Cytosol by Two Distinct Degradation Pathways
Authors: Schmitz Anton , Schneider Andrea , Kummer Markus P. , Herzog Volker
Published: December 2004

The paradigm of endoplasmic reticulum (ER)‐associated degradation (ERAD) holds that misfolded secretory and membrane proteins are translocated back to the cytosol and degraded by the proteasome in a coupled process. Analyzing the degradation of ER‐localized amyloid β‐peptide (Aβ), we found a divergence from this general model. Cell‐free reconstitution of the export in biosynthetically loaded ER‐derived brain microsomes showed that the export was mediated by the Sec61p complex and required a cytosolic factor but was independent of ATP. In contrast to the ERAD substrates known so far, the exported Aβ was degraded by both, a proteasome‐dependent and a proteasome‐independent pathway. RNA interference experiments in Aβ‐transfected cells identified the protease of the proteasome‐independent pathway as insulin‐degrading enzyme (IDE). The IDE‐mediated clearance mechanism for ER‐localized Aβ represents an as yet unknown type of ERAD which is not entirely dependent on the proteasome.
Computed tomography dacryocystography evaluation of the nasolacrimal apparatus
Authors: Nykamp S.G. , Scrivani P.V. , Pease A.P.
Published: December 2004

Computed tomography‐dacryocystography (CT‐DCG) was used to evaluate the nasolacrimal system in four patients (three dogs and one horse) that were admitted for evaluation of chronic epiphora, facial swelling, or facial trauma. The four patients are reviewed and the technique for performing CT‐DCG is described. Additionally, the indications for this procedure are discussed. CT‐DCG is advantageous because cross‐sectional imaging provides superior resolution of the nasolacrimal apparatus and the relatively long, small‐diameter, bony nasolacrimal canal in most veterinary patients.
Effects of serial ultrasound‐guided renal biopsies on kidneys of healthy adolescent dogs
Authors: Groman Reid P. , Bahr Anne , Berridge Brian R. , Lees George E.
Published: December 2004

Ten healthy mixed‐breed dogs were used to evaluate the functional and structural effects of serial ultrasound‐guided renal biopsies obtained with an automated biopsy needle. In each dog, one lateral renal cortex was biopsied at 2, 4, and 6 months of age; the other kidney was the control. Five dogs had two tissue cores and five dogs had four tissue cores taken on each biopsy occasion, and one core was examined microscopically. One week before each biopsy and a month after the final biopsy, the glomerular filtration rate (GFR) was determined by renal scintigraphy. Dogs were then euthanized for evaluation of gross and microscopic lesions attributable to the biopsies. There was no difference between GFR values for biopsied kidneys and those of control kidneys (P>0.05). Microscopic lesions were not identified in biopsies taken at 2 and 4 months, but focal lesions were found in three of 10 specimens taken at 6 months of age. At necropsy, six of 10 biopsied kidneys had small visible capsular scars, and linear tracts <2 mm wide were observed on cut surfaces in six of 10 biopsied kidneys cut transversely into slices 5 mm thick. Discrete light microscopic lesions were observed in 25 of 452 (5.5%) of randomly selected 6‐mm‐diameter sections of renal cortex from biopsied kidneys. We conclude that serial renal cortical biopsies can be obtained by our method from healthy adolescent dogs with minimal risk of inducing changes that might be confused with those of a progressive renal disease.
ESTIMATION OF HOURLY AVERAGE SOLAR RADIATION ON TILTED SURFACE VIA ANNs
Authors: GAZELA MYRSINI , TAMBOURATZIS TATIANA
Published: December 2004

An innovative approach is proposed for the estimation of hourly average solar radiation on tilted surface. The proposed approach, which is based on artificial neural networks and problem decomposition, demonstrates the following characteristics:

• Accuracy. Superior estimation is attained over both conventional approaches and theoretical models.

• Simplicity and efficiency. A small training set is employed and the training/test patterns involve few easily obtainable parameters.

• Generalization capability and robustness to noise.

Apart from being of interest in meteorology, the accurate and efficient estimation of hourly average solar radiation on tilted surface is especially important in solar energy applications.
Cardiac gene expression profile in rats with terminal heart failure and cachexia
Authors: Wellner Maren , Dechend Ralf , Park Joon-Keun , Shagdarsuren Erdenechimeg , Al-Saadi Nidal , Kirsch Torsten , Gratze Petra , Schneider Wolfgang , Meiners Silke , Fiebeler Anette , Haller Hermann , Luft Friedrich C. , Muller Dominik N.
Published: December 2004

About one-half of double transgenic rats (dTGR) overexpressing the human renin and angiotensinogen genes die by age 7 wk of terminal heart failure (THF); the other (preterminal) one-half develop cardiac damage but survive. Our study’s aim was to elucidate cardiac gene expression differences in dTGR-THF compared with dTGR showing compensated cardiac hypertrophy but not yet THF. dTGR treated with losartan (LOS) and nontransgenic rats (SD) served as controls. THF-dTGR body weight was significantly lower than for all other groups. At death, THF-dTGR had blood pressures of 228 ± 7 mmHg (cardiac hypertrophy index 6.2 ± 0.1 mg/g). Tissue Doppler showed reduced peak early (Ea) to late (Aa) diastolic expansion in THF-dTGR, indicating diastolic function. Preterminal dTGR had blood pressures of 197 ± 5 mmHg (cardiac hypertrophy index 5.1 ± 0.1 mg/g); Ea < Aa compared with LOS-dTGR (141 ± 6 mmHg; 3.7±0.1 mg/g; Ea > Aa) and SD (112 ± 4 mmHg; 3.6 ± 0.1 mg/g; Ea > Aa). Left ventricular RNA was isolated for the Affymetrix system and TaqMan RT-PCR. THF-dTGR and dTGR showed upregulation of hypertrophy markers and α/β-myosin heavy chain switch to the fetal isoform. THF-dTGR (vs. dTGR) showed upregulation of 239 and downregulation of 150 genes. Various genes of mitochodrial respiratory chain and lipid catabolism were reduced. In addition, genes encoding transcription factors (CEBP-β, c-fos, Fra-1), coagulation, remodeling/repair components (HSP70, HSP27, heme oxygenase), immune system (complement components, IL-6), and metabolic pathway were differentially expressed. In contrast, LOS-dTGR and SD had similar expression profiles. These data demonstrate that THF-dTGR show an altered expression profile compared with preterminal dTGR.
Genetic expression profiles during physiological and pathological cardiac hypertrophy and heart failure in rats
Authors: Kong Sek Won , Bodyak Natalya , Yue Patrick , Liu Zhilin , Brown Jeffrey , Izumo Seigo , Kang Peter M.
Published: December 2004

Cardiac hypertrophy is a complex and nonhomogenous response to various stimuli. In this study, we used high-density oligonucleotide microarray to examine gene expression profiles during physiological hypertrophy, pathological hypertrophy, and heart failure in Dahl salt-sensitive rats. There were changes in 404/3,160 and 874/3,160 genes between physiological and pathological hypertrophy and the transition from hypertrophy to heart failure, respectively. There were increases in stress response genes (e.g., heat shock proteins) and inflammation-related genes (e.g., pancreatitis-associated protein and arachidonate 12-lipoxygenase) in pathological processes but not in physiological hypertrophy. Furthermore, atrial natriuretic factor and brain natriuretic protein showed distinctive changes that are very specific to different conditions. In addition, we used a resampling-based gene score-calculating method to define significantly altered gene clusters, based on Gene Ontology classification. It revealed significant alterations in genes involved in the apoptosis pathway during pathological hypertrophy, suggesting that the apoptosis pathway may play a role during the transition to heart failure. In addition, there were significant changes in glucose/insulin signaling, protein biosynthesis, and epidermal growth factor signaling during physiological hypertrophy but not during pathological hypertrophy.
Microarray analysis of selection lines from outbred populations to identify genes involved with nematode parasite resistance in sheep
Authors: Diez-Tascón Cristina , Keane Orla M. , Wilson Theresa , Zadissa Amonida , Hyndman Dianne L. , Baird David B. , McEwan John C. , Crawford Allan M.
Published: December 2004

Gastrointestinal nematodes infect sheep grazing contaminated pastures. Traditionally, these have been controlled with anthelmintic drenching. The selection of animals resistant to nematodes is an alternative to complete reliance on drugs, but the genetic basis of host resistance is poorly understood. Using a 10,204 bovine cDNA microarray, we have examined differences in gene expression between genetically resistant and susceptible lambs previously field challenged with larval nematodes. Northern blot analysis for a selection of genes validated the data obtained from the microarrays. The results identified over one hundred genes that were differentially expressed based on conservative criteria. The microarray results were further analyzed to identify promoter motifs common to the differentially expressed genes. Motifs identified in upregulated gene promoters were primarily restricted to those promoters; however, motifs identified in downregulated gene promoters were also found in the promoters of upregulated genes but not in the promoters of genes whose expression was unaltered. Protein Annotators’ Assistant was used for lexical analysis of the differentially expressed genes, and Gene Ontology was used to look for metabolic and cell signaling pathways associated with parasite resistance. Two pathways represented by genes differentially expressed in resistant animals were those involved with the development of an acquired immune response and those related to the structure of the intestine smooth muscle. Genes involved in these processes appear from our analysis to be key genetic determinants of parasite resistance.
Mitochondrial Ca
2+
-Activated K
+
Channels in Cardiac Myocytes
Authors: Sato Toshiaki , Saito Tomoaki , Saegusa Noriko , Nakaya Haruaki
Published: December 2004

Background—

The large-conductance Ca
2+
-activated K
+
(BK
Ca
) channel in the cardiac inner mitochondrial membrane (mitoK
Ca
channel) has been shown to protect the heart against ischemic injury. However, questions about the cardioprotective mechanism and the kinase-mediated regulation of mitoK
Ca
channels remain to be answered.

Methods and Results—

Flavoprotein fluorescence in guinea pig ventricular myocytes was measured to assay mitoK
Ca
channel activity. The mitochondrial Ca
2+
concentration ([Ca
2+
]
m
) and membrane potential (ΔΨ
m
) were measured by loading cells with rhod-2 and JC-1, respectively. Cell death was assessed by trypan blue permeability. The BK
Ca
channel opener NS1619 reversibly increased the flavoprotein oxidation in a concentration-dependent manner. NS1619 (30 μmol/L) attenuated the ouabain (1 mmol/L)-induced elevation of [Ca
2+
]
m
with accompanying depolarization of ΔΨ
m
. These effects of NS1619 were completely antagonized by the BK
Ca
channel blocker paxilline (2 μmol/L) but not by the mitochondrial ATP-sensitive K
+
(mitoK
ATP
) channel blocker 5-hydroxydecanoate (500 μmol/L). Paxilline, however, failed to block the oxidative effect of diazoxide (100 μmol/L), a mitoK
ATP
channel opener. The combined application of submaximally effective concentrations of NS1619 (10 μmol/L) and diazoxide (30 μmol/L) produced additive effects. NS1619 (30 μmol/L) blunted the rate of cell death during exposure to ouabain; this cardioprotective effect was prevented by paxilline. Activation of cAMP-dependent protein kinase by 8-bromoadenosine 3′5′-cyclic monophosphate (0.5 mmol/L) and forskolin (10 μmol/L) potentiated the NS1619-induced flavoprotein oxidation.

Conclusions—

Opening of mitoK
Ca
channels, which is modulated by cAMP-dependent protein kinase, depolarizes the ΔΨ
m
and attenuates the mitochondrial Ca
2+
overload. Our study further indicates that mitoK
Ca
channel activation confers cardioprotection in a manner similar to but independent of mitoK
ATP
channel activation.