bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of Streptozotocin‐Induced Diabetes on Rat Brain Mitochondria
Authors: Moreira P. I. , Santos M. S. , Moreno A. M. , Proença T. , Seiça R. , Oliveira C. R. 
Published: September 2009

AbstractThis study evaluated several parameters related to mitochondrial function and oxidative stress in streptozotocin (STZ)‐treated rats, a model of type 1 diabetes. For this purpose, the respiratory indexes (RCR and ADP/O ratio), mitochondrial transmembrane potential (ΔΨm), repolarization lag phase, repolarization level, mitochondrial enzymatic activities, ATP and malondialdehyde (MDA) levels, reduced glutathione (GSH), vitamin E and cardiolipin contents were determined in rat brain mitochondria isolated after 4 and 9 weeks after STZ treatment. Brain mitochondria isolated from citrate (vehicle)‐treated Wistar rats were used as control. We observed that STZ‐induced diabetes did not substantially affect brain mitochondrial function. Instead, 4‐week diabetic rats presented higher mitochondrial respiratory chain enzymatic activities, especially succinate‐cytochrome C reductase activity, compared to 4‐week control rats. In 9‐week diabetic rats, only a significant decrease in cardiolipin content was observed; however, a significant increase in mitochondrial GSH content occurred. All other parameters analysed remained statistically unchanged. From these results, we conclude that STZ‐induced diabetes did not promote brain mitochondrial dysfunction, suggesting that oxidative stress associated with type 1 diabetes is not directly related to mitochondrial dysfunction, but probably is related to extramitochondrial factor(s).
Evolutionary, behavioural and molecular ecology must meet to achieve long‐term conservation goals
Authors: SCOTT KEOGH J. 
Published: September 2009

Founder populations in reintroduction programmes can experience a genetic bottleneck simply because of their small size. The influence of reproductive skew brought on by polygynous or polyandrous mating systems in these populations can exacerbate already difficult conservation genetic problems, such as inbreeding depression and loss of adaptive potential. Without an understanding of reproductive skew in a target species, and the effect it can have on genetic diversity retained over generations, long‐term conservation goals will be compromised. In this issue of Molecular Ecology, Miller et al. (2009a) test how founder group size and variance in male reproductive success influence the maintenance of genetic diversity following reintroduction on a long‐term scale. They evaluated genetic diversity in two wild populations of the iconic New Zealand tuatara (Fig. 1), which differ greatly in population size and genetic diversity, and compared this to genetic diversity in multiple founder populations sourced from both populations. Population viability analysis on the maintenance of genetic diversity over 400 years (10 generations) demonstrated that while the loss of heterozygosity was low when compared with both source populations (1–14%), the greater the male reproductive skew, the greater the predicted losses of genetic diversity. Importantly however, the loss of genetic diversity was ameliorated after population size exceeded 250 animals, regardless of the level of reproductive skew. This study demonstrates that highly informed conservation decisions could be made when you build on a solid foundation of demographic, natural history and behavioural ecology data. These data, when informed by modern population and genetic analysis, mean that fundamental applied conservation questions (how many animals should make up a founder population?) can be answered accurately and with an eye to the long‐term consequences of management decisions. Large adult male tuatara attacking a smaller male. Photo by Jeanine Refsnider.image
The queen is dead—long live the workers: intraspecific parasitism by workers in the stingless bee Melipona scutellaris
Authors: ALVES D. A. , IMPERATRIZ‐FONSECA V. L. , FRANCOY T. M. , SANTOS‐FILHO P. S. , NOGUEIRA‐NETO P. , BILLEN J. , WENSELEERS T. 
Published: September 2009

AbstractInsect societies are well known for their high degree of cooperation, but their colonies can potentially be exploited by reproductive workers who lay unfertilized, male eggs, rather than work for the good of the colony. Recently, it has also been discovered that workers in bumblebees and Asian honeybees can succeed in entering and parasitizing unrelated colonies to produce their own male offspring. The aim of this study was to investigate whether such intraspecific worker parasitism might also occur in stingless bees, another group of highly social bees. Based on a large‐scale genetic study of the species Melipona scutellaris, and the genotyping of nearly 600 males from 45 colonies, we show that ∼20% of all males are workers’ sons, but that around 80% of these had genotypes that were incompatible with them being the sons of workers of the resident queen. By tracking colonies over multiple generations, we show that these males were not produced by drifted workers, but rather by workers that were the offspring of a previous, superseded queen. This means that uniquely, workers reproductively parasitize the next‐generation workforce. Our results are surprising given that most colonies were sampled many months after the previous queen had died and that workers normally only have a life expectancy of ∼30 days. It also implies that reproductive workers greatly outlive all other workers. We explain our results in the context of kin selection theory, and the fact that it pays workers more from exploiting the colony if costs are carried by less related individuals.
The third pillar of bacterial signal transduction: classification of the extracytoplasmic function (ECF) σ factor protein family
Authors: Staroń Anna , Sofia Heidi J. , Dietrich Sascha , Ulrich Luke E. , Liesegang Heiko , Mascher Thorsten 
Published: September 2009

SummaryThe ability of a bacterial cell to monitor and adaptively respond to its environment is crucial for survival. After one‐ and two‐component systems, extracytoplasmic function (ECF) σ factors – the largest group of alternative σ factors – represent the third fundamental mechanism of bacterial signal transduction, with about six such regulators on average per bacterial genome. Together with their cognate anti‐σ factors, they represent a highly modular design that primarily facilitates transmembrane signal transduction. A comprehensive analysis of the ECF σ factor protein family identified more than 40 distinct major groups of ECF σ factors. The functional relevance of this classification is supported by the sequence similarity and domain architecture of cognate anti‐σ factors, genomic context conservation, and potential target promoter motifs. Moreover, this phylogenetic analysis revealed unique features indicating novel mechanisms of ECF‐mediated signal transduction. This classification, together with the web tool ECFfinder and the information stored in the Microbial Signal Transduction (MiST) database, provides a comprehensive resource for the analysis of ECF σ factor‐dependent gene regulation.
The right half of the Escherichia coli replication origin is not essential for viability, but facilitates multi‐forked replication
Authors: Stepankiw Nicholas , Kaidow Akihiro , Boye Erik , Bates David 
Published: September 2009

SummaryReplication initiation is a key event in the cell cycle of all organisms and oriC, the replication origin in Escherichia coli, serves as the prototypical model for this process. The minimal sequence required for oriC function was originally determined entirely from plasmid studies using cloned origin fragments, which have previously been shown to differ dramatically in sequence requirement from the chromosome. Using an in vivo recombineering strategy to exchange wt oriCs for mutated ones regardless of whether they are functional origins or not, we have determined the minimal origin sequence that will support chromosome replication. Nearly the entire right half of oriC could be deleted without loss of origin function, demanding a reassessment of existing models for initiation. Cells carrying the new DnaA box‐depleted 163 bp minimal oriC exhibited little or no loss of fitness under slow‐growth conditions, but were sensitive to rich medium, suggesting that the dense packing of initiator binding sites that is a hallmark of prokaryotic origins, has likely evolved to support the increased demands of multi‐forked replication.
A Comparative Study of Transfection Methods for RNA Interference in Bone Marrow‐Derived Murine Dendritic Cells
Authors: Pedersen C. D. , Fang J. J. , Pedersen A. E. 
Published: September 2009

AbstractSelective gene silencing using RNA interference (RNAi) has been shown to be an efficient method for manipulation of cellular functions. In this study, we compare three previously established methods for transfection of murine bone marrow‐derived DC (BM‐DC). We tested the efficacy of electroporation with the Mouse Nucleofector kit® from Amaxa Biosystems and lipid‐based transfection methods using transfection reagents from Santa Cruz Biotechnology or Genlantis. To analyse the transfection efficacy we used FITC‐conjugated siRNA as a positive control together with CD80 and CD86 specific siRNA. We show that electroporation using the Mouse Nucleofector kit® from Amaxa Biosystems was not an efficient method to transfect BM‐DC with siRNA in our hands. Transfection with Santa Cruz Biotechnology reagents resulted in up to 59% FITC‐siRNA positive cells, but did not result in effective silencing of CD80 surface expression. In contrast, the most effective method was the lipid‐based method using the siRNA transfection reagent GeneSilencer® from Genlantis. This protocol resulted in up to 92% FITC‐siRNA positive cells after 4 h which declined to 62% and 59% 24 and 48 h post‐transfection, respectively. The transfected BM‐DC remained CD11c positive, expressed high MHC class II and intermediate CD40 and were functional as APC. In conclusion, this protocol was effective for manipulation of murine BM‐DC function through the use of specific siRNA and such methods can be important for the future study of DC–T cell interactions.
Pectin activation of MAP kinase and gene expression is WAK2 dependent
Authors: Kohorn Bruce D. , Johansen Susan , Shishido Akira , Todorova Tanya , Martinez Rhysly , Defeo Elita , Obregon Pablo 
Published: September 2009

SummaryThe angiosperm extracellular matrix, or cell wall, is composed of a complex array of cellulose, hemicelluose, pectins and proteins, the modification and regulated synthesis of which are essential for cell growth and division. The wall associated kinases (WAKs) are receptor‐like proteins that have an extracellular domain that bind pectins, the more flexible portion of the extracellular matrix, and are required for cell expansion as they have a role in regulating cellular solute concentrations. We show here that both recombinant WAK1 and WAK2 bind pectin in vitro. In protoplasts pectins activate, in a WAK2‐dependent fashion, the transcription of vacuolar invertase, and a wak2 mutant alters the normal pectin regulation of mitogen‐activated protein kinases. Microarray analysis shows that WAK2 is required for the pectin activation of numerous genes in protoplasts, many of which are involved in cell wall biogenesis. Thus, WAK2 plays a major role in signaling a diverse array of cellular events in response to pectin in the extracellular matrix.
The Populus homeobox gene ARBORKNOX2 regulates cell differentiation during secondary growth
Authors: Du Juan , Mansfield Shawn D. , Groover Andrew T. 
Published: September 2009

SummaryThe stem cells of the vascular cambium divide to produce daughter cells, which in turn divide before undergoing differentiation during the radial growth of woody stems. The genetic regulation of these developmental events is poorly understood, however. We report here the cloning and functional characterization of a Populus class‐I KNOX homeobox gene, ARBORKNOX2 (ARK2), which we show influences terminal cell differentiation and cell wall properties during secondary growth. In the early stages of secondary growth, ARK2 is expressed broadly in the cambial zone and in terminally differentiating cell types, before becoming progressively restricted to the cambium. ARK2 overexpression and synthetic miRNA‐suppression transgenics reveal positive correlations between ARK2 expression level and the timing of cambium formation, the width of the cambial zone and inhibition of cambial daughter cell differentiation. These phenotypes in turn correlate with changes in the expression of genes affecting transcription, cell division, auxin and cell wall synthesis. Notably, wood properties associated with secondary cell wall synthesis are negatively associated with ARK2 expression, including lignin and cellulose content. Together, our results suggest that ARK2 functions primarily to regulate a complex suite of genes that together influence cell differentiation during secondary growth. We propose that ARK2 may represent a co‐evolved transcriptional module that influences complex, adaptive wood properties.
Levels of childhood vaccination coverage and the impact of maternal HIV status on child vaccination status in rural KwaZulu‐Natal, South Africa*
Authors: Ndirangu James , Bärnighausen Till , Tanser Frank , Tint Khin , Newell Marie‐Louise 
Published: September 2009

SummaryObjectives  To analyse coverage of childhood vaccinations in a rural South African population and investigate whether maternal HIV status is associated with children’s vaccination status.Methods  2 431 children with complete information, 12–23 months of age at some point during the period January 2005 through December 2006 and resident in the Africa Centre Demographic Surveillance Area at the time of their birth were investigated. We examined the relationship between maternal HIV status and child vaccination status for five vaccinations [Bacillus Calmette‐Guérin (BCG), diphtheria‐tetanus‐pertussis (DTP3), poliomyelitis (polio3), hepatitis B (HepB3), and measles] in multiple logistic regressions, controlling for household wealth, maternal age, maternal education and distances to roads, fixed and mobile clinics.Results  Coverage of the five vaccinations ranged from 89.3% (95% CI 81.7–93.9) for BCG to 77.3% (67.1–83.6) for measles. Multivariably, maternal HIV‐positive status was significantly associated with lower adjusted odds ratios (AOR) of child vaccination for all vaccines [(AOR) 0.60–0.74, all P ≤ 0.036] except measles (0.75, P = 0.073), distance to mobile clinic was negatively associated with vaccination status (all P ≤ 0.029), household wealth was positively (all P ≤ 0.013) and distance to nearest road negatively (all P ≤ 0.004) associated with vaccination status.Conclusion  Positive maternal HIV status independently reduces children’s probability to receive child vaccinations, which likely contributes to the morbidity and mortality differential between children of HIV‐positive and HIV‐negative mothers. As a means of increasing vaccination coverage, policy makers should consider increasing the number of mobile clinics in this and similar communities in rural Africa.
RESEARCH FOCUS ON COMPULSIVE BEHAVIOUR IN ANIMALS: Compulsive alcohol drinking in rodents
Authors: Vengeliene Valentina , Celerier Evelyne , Chaskiel Lea , Penzo Franco , Spanagel Rainer 
Published: September 2009

ABSTRACTUpon prolonged alcohol exposure, the behaviour of an individual can gradually switch from controlled to compulsive. Our review is focused on the neurobiological mechanisms that might underlie this transition as well as the factors that are influencing it. Animal studies suggest that temporally increased alcohol consumption during post‐abstinence drinking is accompanied by a loss of flexibility of the behaviour and therefore, could serve as a model for compulsive alcohol drinking. However, studies using different alcohol‐preferring rat lines in the post‐abstinence drinking model suggest that high alcohol consumption does not necessarily lead to the development of compulsive drinking. This indicates the significance of genetic predisposition to compulsive behaviour. Neuroimaging data show that chronic alcohol consumption affects the activity of several brain regions such as the extrapyramidal motor system and several areas of the prefrontal cortex including the orbitofrontal and anterior cingulate cortex. Similar changes in brain activity is seen in patients suffering from obsessive–compulsive disorder at baseline conditions and during provocation of obsessive thoughts and urge to perform compulsive‐like rituals. This indicates that dysfunction of these regions may be responsible for the expression of compulsive components of alcohol drinking behaviour. Several brain neurotransmitter systems seem to be responsible for the switch from controlled to compulsive behaviour. In particular, hypofunctioning of monoaminergic systems and hyperfunctioning of glutamatergic systems may play a role in compulsive alcohol drinking.
German citizens in southeastern Spain: a study of attitude toward organ donation
Authors: Ríos A. , Martínez‐Alarcón L. , Sánchez J. , Jarvis N. , Parrilla P. , Ramírez P. 
Published: September 2009

Ríos A, Martínez‐Alarcón L, Sánchez J, Jarvis N, Parrilla P, Ramírez P. German citizens in southeastern Spain: a study of attitude toward organ donation. Clin Transplant 2010: 24: 349–357. © 2009 John Wiley & Sons A/SAbstract: Background:  Spain is frequently a place of residence for a high percentage of the German population. Our aim is to analyze the attitude of the German population that is resident in Spain toward organ donation.Methods:  A sample of German residents in the south east of Spain was obtained randomly between November 2005 and April 2006 (n = 227). Attitude was evaluated using a validated questionnaire. This survey was self‐administered and completed anonymously. Control group: a sample of 2000 Spanish citizens.Results:  There is a favorable attitude toward donation in 64% of respondents, similar to the control group (64% vs. 63%; p = 0.8545). The most important factors that affect such attitude are: (i) having dependents (odds ratio = 4.569); (ii) having talked about donation within the family (OR = 4.132); (iii) being willing to accept an autopsy if one were necessary (OR = 5.952); (iv) having had previous experience of organ donation and transplantation (OR = 5.814); (v) not being concerned about mutilation of the cadaver (OR = 8.792); and (vi) the attitude of one’s partner toward donation, especially when this is negative (OR = 0.002).Conclusions:  The attitude toward organ donation of Germans who usually reside in Spain is the same as that described in the native Spanish population, and is determined by many psychosocial factors.
Cytotoxic T lymphocyte‐associated antigen‐4 polymorphism in patients with rheumatic heart disease
Authors: Düzgün N. , Duman T. , Haydardedeoğlu F. E. , Tutkak H. 
Published: September 2009

AbstractAcute rheumatic fever (ARF) is a systemic inflammatory disease occurring as a consequence of an exaggerated immune response to group A, beta haemolytic streptococcal pharyngitis. The molecular mimicry between human target organs/tissues and specific components of the infectious organism leads to the development of autoimmune reactions and cardiac tissue damage in rheumatic heart disease (RHD). Cytotoxic T lymphocyte‐associated antigen‐4 (CTLA‐4) is a negative regulator of T cell activation and proliferation during the immune response. CTLA‐4 gene polymorphism has been shown to affect the inhibitory function of CTLA‐4. We aimed to analyze the association of CTLA‐4 gene locus at position 49 of exon 1 with susceptibility to ARF/RHD. This study included a total of 98 patients with RHD as a sequela of ARF, who fulfilled the revised classification criteria of Jones and 154 healthy unrelated controls. CTLA‐4 +49 A/G polymorphism was genotyped by using PCR‐RLFP technique. Data was analyzed by binary logistic regression models. The frequencies of GG, GA and AA genotypes were found to be 14%, 47% and 39%, respectively, in patients and 6%, 45% and 49%, respectively, in controls. The GG genotype was found to be significantly different between patients and controls (OR: 3.11; P = 0.016). GA and AA genotypes did not statistically differ between patients and controls. Our data showed a significant association of +49G /G polymorphism in a small patient group with RHD.
Pharmacokinetics of intraperitoneally instilled aminophylline, terbutaline and tobramycin in pigs
Authors: ÅSHEIM P. , SPIGSET O. , AASARØD K. , WALSTAD R. A. , UGGEN P. E. , ZAHLSEN K. , AADAHL P. 
Published: September 2009

Introduction: Venous catheters are sometimes difficult or even impossible to insert and may also be associated with serious complications. This study was carried out to investigate whether intraperitoneal administration of drugs may be an alternative to the intravenous route in patients with limited vascular access.Materials and methods: Three drugs commonly in use in clinical practise, aminophylline, terbutaline and tobramycin, were administered to pigs intravenously and intraperitoneally in small volumes. Serum concentrations were analysed over a period of 6 h and pharmacokinetic key variables for each drug were calculated.Results: Aminophylline (theophylline), terbutaline and tobramycin were absorbed from the peritoneal space and into systemic circulation. For theophylline, the concentration/time profiles after intraperitoneal and after intravenous administration were almost identical, and the intraperitoneal bioavailability was calculated to 0.94. For terbutaline and tobramycin, the intraperitoneal absorption was delayed without any initial peak. Moreover, the intraperitoneal bioavailability was lower than for theophylline (0.71 and 0.65, respectively).Conclusion: The pharmacokinetic properties after intraperitoneal administration differed among the three drugs, but the results are encouraging and provide a basis for further investigation in humans.