bluuebunny/crossref_metadata_2025_split huggingface dataset:
Increased calcium influx in the presence of ethanol in mouse pancreatic acinar cells
Authors: Del Castillo‐Vaquero Angel , Salido Ginés M. , González Antonio 
Published: December 2009

SummaryThe effects of alcohol on Ca2+ signalling remains poorly understood. Here we have investigated the effects of acute ethanol exposure on Ca2+ influx in mouse pancreatic acinar cells. Cells were loaded with fura‐2 and the changes in fluorescence were monitored by spectrofluorimetry and imaging analysis. Stimulation of cells with 20 pM cholecystokinin evoked an oscillatory pattern in [Ca2+]c, both in the presence and in the absence of extracellular Ca2+. Stimulation of cells with cholecystokinin in the presence of 50 mM ethanol led to a transformation of physiological oscillations into a single transient increase in [Ca2+]c. This effect was observed when Ca2+ was present in the extracellular medium, and did not appear in its absence. Addition of 1 mM CaCl2 to the extracellular medium, following release of Ca2+ from intracellular stores by stimulation of cells with 1 nM cholecystokinin or 1 μM thapsigargin in the absence of extracellular Ca2+, was followed by an increase in [Ca2+]c. Ca2+ influx was increased in the presence of 50 mM ethanol. The anti‐oxidant cinnamtannin B‐1 (10 μM) or inhibition of alcohol dehydrogenase by 4‐MP (1 mM), significantly reduced Ca2+ influx evoked by cholecystokinin in the presence of ethanol. In summary, intoxicating concentrations of ethanol may lead to over stimulation of pancreatic acinar cells by cholecystokinin. This might be partially explained by the generation of reactive oxygen species and an increased Ca2+ entry in the presence of ethanol. Potentially ethanol might lead to Ca2+ overload, which is a common pathological precursor that is implicated in pancreatitis.
Tits on the move: exploring the impact of environmental change on blue tit and great tit migration distance
Authors: Smallegange Isabel M. , Fiedler Wolfgang , Köppen Ulrich , Geiter Olaf , Bairlein Franz 
Published: December 2009

Summary1.In response to warmer spring conditions in Central Europe many migratory bird species have shifted their timing of breeding. Environmental change has also led to warmer winters, shortening the distance between the breeding grounds of migratory birds and their overwintering areas.2.Here, we show that in response to warmer winters, blue tits (Cyanistes caeruleus), but not great tits (Parus major), breeding in Germany decreased their migration distance between 1964 and 1996. Understanding this difference provides insight into possible constraints and selection pressures involved in how species respond to environmental change. Here, we focus on their breeding ecology.3.In a nest box population in southern Germany, both species laid their first clutch earlier with increasing spring temperature, but over the study period (1974–1999) blue tits showed a significant and stronger advancement in laying date than great tits. For both species, selection for earlier breeding did not vary with environmental change, indicating that early laying pairs did not do better than later laying pairs as spring temperature increased.4.Blue tits in the nest box population were single‐brooded and existing hypotheses state that single‐brooded species likely advance their laying date to match timing of reproduction with the advancing food peak in spring. We hypothesize that this might be one reason why blue tits adjusted their migration strategy as closer proximity to the breeding grounds in winter allows better prediction of the onset of spring. Ten per cent of great tits successfully produced second broods and their first clutch laying date is a compromise between first and second clutch laying date, which might be why great tits had not advanced their laying date nor altered their migration strategy.
Host specificity, phenotype matching and the evolution of reproductive isolation in a coevolved plant–pollinator mutualism
Authors: HIMLER ANNA G. , MACHADO CARLOS A. 
Published: December 2009

Coevolutionary interactions between plants and their associated pollinators and seed dispersers are thought to have promoted the diversification of flowering plants (Raven 1977; Regal 1977; Stebbins 1981). The actual mechanisms by which pollinators could drive species diversification in plants are not fully understood. However, it is thought that pollinator host specialization can influence the evolution of reproductive isolation among plant populations because the pollinator’s choice of host is what determines patterns of gene flow in its host plant, and host choice may also have important consequences on pollinator and host fitness (Grant 1949; Bawa 1992). In this issue of Molecular Ecology, Smith et al. (2009) present a very interesting study that addresses how host specialization affects pollinator fitness and patterns of gene flow in a plant host. Several aspects of this study match elements of a seminal mathematical model of plant–pollinator codivergence (Kiester et al. 1984) suggesting that reciprocal selection for matched plant and pollinator reproductive traits may lead to speciation in the host and its pollinator when there is strong host specialization and a pattern of geographic subdivision. Smith et al.’s study represents an important step to fill the gap in our understanding of how reciprocal selection may lead to speciation in coevolved plant–pollinator mutualisms.
Methanogenesis by Methanosarcina acetivorans involves two structurally and functionally distinct classes of heterodisulfide reductase
Authors: Buan Nicole R. , Metcalf William W. 
Published: December 2009

SummaryBiochemical studies have revealed two distinct classes of Coenzyme B‐Coenzyme M heterodisulfide (CoB‐S‐S‐CoM) reductase (Hdr), a key enzyme required for anaerobic respiration in methane‐producing archaea. A cytoplasmic HdrABC enzyme complex is found in most methanogens, whereas a membrane‐bound HdrED complex is found exclusively in members of the order Methanosarcinales. Unexpectedly, genomic data indicate that multiple copies of both Hdr classes are found in all sequenced Methanosarcinales genomes. The Methanosarcina acetivorans hdrED1 operon is constitutively expressed and required for viability under all growth conditions examined, consistent with HdrED being the primary Hdr. HdrABC appears to be specifically involved in methylotrophic methanogenesis, based on reduced growth and methanogenesis rates of an hdrA1C1B1 mutant on methylotrophic substrates and downregulation of the genes during growth on acetate. This conclusion is further supported by phylogenetic analysis showing that the presence of hdrA1 in an organism is specifically correlated with the presence of genes for methylotrophic methanogenesis. Examination of mRNA abundance in methanol‐grown ΔhdrA1C1B1 strains relative to wild‐type revealed upregulation of genes required for synthesis of (di)methylsulfide and for transport and biosynthesis of CoB‐SH and CoM‐SH, suggesting that the mutant has a defect in electron transfer from ferredoxin to CoB‐S‐S‐CoM that causes cofactor limitation.
Sequential translocation of an Escherchia coli two‐partner secretion pathway exoprotein across the inner and outer membranes
Authors: Choi Peter S. , Bernstein Harris D. 
Published: December 2009

SummaryIn Gram‐negative bacteria, a variety of high molecular weight ‘exoproteins’ are translocated across the outer membrane (OM) via the two‐partner secretion (TPS) pathway by interacting with a dedicated transporter. It is unclear, however, whether the translocation of exoproteins across the OM is coupled to their translocation across the inner membrane (IM). To address this question, we separated the production of an Escherichia coli O157:H7 exoprotein (OtpA) and its transporter (OtpB) temporally by placing otpA and otpB under the control of distinct regulatable promoters. We found that when both full‐length and truncated forms of OtpA were expressed prior to OtpB, a significant fraction of the exoprotein was secreted. The results indicate that OtpA can be translocated into the periplasm and briefly remain secretion‐competent. Furthermore, by engineering cysteine residues into OtpA and using disulphide bond formation as a reporter of periplasmic localization, we obtained additional evidence that the C‐terminus of OtpA enters the periplasm before the N‐terminus is translocated across the OM even when OtpA and OtpB are expressed simultaneously. Taken together, our results demonstrate that the translocation of a TPS exoprotein across the OM can occur independently from its translocation across the IM.
Differential effects and interactions of endogenous and horizontally acquired H‐NS‐like proteins in pathogenic Escherichia coli
Authors: Müller Claudia M. , Schneider György , Dobrindt Ulrich , Emödy Levente , Hacker Jörg , Uhlin Bernt Eric 
Published: December 2009

SummaryThe nucleoid‐associated protein H‐NS is important for gene regulation in Escherichia coli. We have studied H‐NS interaction with StpA and an uncharacterized H‐NS‐like protein, Hfp, in the uropathogenic E. coli isolate 536 that expresses all three nucleoid‐associated proteins. We found distinct interactions of the three proteins at the protein level, resulting in the formation of heteromers, as well as differences in their gene expression at the transcriptional level. Mutants lacking either StpA or Hfp alone did not exhibit a phenotype at 37°C, which is consistent with a low level of expression at that temperature. Expression of the hfp and stpA genes was found to be induced by apparently diametrical conditions, and StpA and Hfp levels could be correlated to modulatory effects on the expression of different H‐NS targets, the bgl operon and operons for virulence factors such as fimbriae and capsular polysaccharide. The hns/hfp and hns/stpA double mutants displayed severe growth defects at low and high temperatures respectively. Our findings demonstrated different requirements for the alternative H‐NS/Hfp/StpA combinations under these growth conditions. We propose that Hfp and StpA have distinct functions and roles in a dynamic pool of nucleoid‐associated proteins that is adapting to requirements in a particular environment.
Transcriptional regulation of the Yts1 type II secretion system of Yersinia enterocolitica and identification of secretion substrates
Authors: Shutinoski Bojan , Schmidt M. Alexander , Heusipp Gerhard 
Published: December 2009

SummaryType II secretion systems (T2SSs) mediate the transport of proteins through the bacterial outer membrane. Although widespread in γ‐proteobacteria, they have so far not been characterized in the human pathogen Yersinia enterocolitica. We describe here genetic linkage of the Yts1 and Yts2 T2SSs with a transcriptional regulator in the highly pathogenic Y. enterocolitica biotype 1B. While the Yts2‐associated PypC regulator activates the Yts2 operon, the PclR regulator does not induce transcription of its cognate Yts1 operon. Instead, Yts1 and pclR are activated by the addition of MgCl2 to the growth medium at 17°C and 26°C, but not at 37°C. We identified three proteins, ChiY, EngY (YE2830) and YE3650, that are secreted depending on a functional Yts1 T2SS in response to MgCl2 at low temperature. While the activation of chiY by MgCl2 depends on pclR, PclR overproduction is not sufficient for chiY transcription in an Escherichia coli background, demonstrating the need for additional Y. enterocolitica‐specific factors. As ChiY and EngY both bind to chitin, and YE3650 shows motifs conserved in oligosaccharide‐binding enzymes, all secreted proteins might be important for polysaccharide interaction/degradation during infection or in the environment.
Ordered association of helicase loader proteins with the Bacillus subtilis origin of replication in vivo
Authors: Smits Wiep Klaas , Goranov Alexi I. , Grossman Alan D. 
Published: December 2009

SummaryThe essential proteins DnaB, DnaD and DnaI of Bacillus subtilis are required for initiation, but not elongation, of DNA replication, and for replication restart at stalled forks. The interactions and functions of these proteins have largely been determined in vitro based on their roles in replication restart. During replication initiation in vivo, it is not known if these proteins, and the replication initiator DnaA, associate with oriC independently of each other by virtue of their DNA binding activities, as a (sub)complex like other loader proteins, or in a particular dependent order. We used temperature‐sensitive mutants or a conditional degradation system to inactivate each protein and test for association of the other proteins with oriC in vivo. We found that there was a clear order of stable association with oriC; DnaA, DnaD, DnaB, and finally DnaI‐mediated loading of helicase. The loading of helicase via stable intermediates resembles that of eukaryotes and the established hierarchy provides several potential regulatory points. The general approach described here can be used to analyse assembly of other complexes.
National health insurance coverage and socio‐economic status in a rural district of Ghana
Authors: Sarpong N. , Loag W. , Fobil J. , Meyer C. G. , Adu‐Sarkodie Y. , May J. , Schwarz N. G. 
Published: December 2009

SummaryObjective  To explore the association between socio‐economic status (SES) and health insurance subscription to the Ghanaian National Health Insurance Scheme (NHIS) of residents of the Asante Akim North district of the Ashanti Region, Ghana.Methods  In the course of a community survey, data on asset variables (e.g. electricity, housing conditions and other variables) and on NHIS subscription were collected on the household level in 99 villages. Using principal components analysis, households were classified into three categories of SES (20% high, 40% middle and 40% low SES). Odds ratios of NHIS subscription were calculated for all SES categories, using the low category as the reference group and adjusting for travelling time to health facilities by public transport.Results  Of the 7223 households surveyed, 38% subscribed to the NHIS, of these 21% were low, 43% middle and 60% high SES households. SES was significantly associated with NHIS subscription (high SES: OR 4.9, 95% CI 4.3–5.7; middle SES: OR 2.5, 95% CI 2.2–2.9; low SES: OR 1, reference group).Conclusion  Four years after its introduction, the NHIS has reached subscription rates of 38% in the district surveyed. However, to achieve the aim of assuring universal access to health care facilities for all residents of Ghana, in particular for individuals living under socio‐economic constraints, increasing subscription rates are necessary.
Blood glucose and prognosis in children with presumed severe malaria: is there a threshold for ‘hypoglycaemia’?
Authors: Willcox Merlin L. , Forster Mathieu , Dicko Moussa I. , Graz Bertrand , Mayon‐White Richard , Barennes Hubert 
Published: December 2009

SummaryObjectives  Hypoglycaemia (glucose <2.2 mmol/l) is a defining feature of severe malaria, but the significance of other levels of blood glucose has not previously been studied in children with severe malaria.Methods  A prospective study of 437 consecutive children with presumed severe malaria was conducted in Mali. We defined hypoglycaemia as <2.2 mmol/l, low glycaemia as 2.2–4.4 mmol/l and hyperglycaemia as >8.3 mmol/l. Associations between glycaemia and case fatality were analysed for 418 children using logistic regression models and a receiver operator curve (ROC).Results  There was a significant difference between blood glucose levels in children who died (median 4.6 mmol/l) and survivors (median 7.6 mmol/l, P < 0.001). Case fatality declined from 61.5% of the hypoglycaemic children to 46.2% of those with low glycaemia, 13.4% of those with normal glycaemia and 7.6% of those with hyperglycaemia (P < 0.001). Logistic regression showed an adjusted odds ratio (AOR) of 0.75 (0.64–0.88) for case fatality per 1 mmol/l increase in baseline blood glucose. Compared to a normal blood glucose, hypoglycaemia and low glycaemia both significantly increased the odds of death (AOR 11.87, 2.10–67.00; and 5.21, 1.86–14.63, respectively), whereas hyperglycaemia reduced the odds of death (AOR 0.34, 0.13–0.91). The ROC [area under the curve at 0.753 (95% CI 0.684–0.820)] indicated that glycaemia had a moderate predictive value for death and identified an optimal threshold at glycaemia <6.1 mmol/l, (sensitivity 64.5% and specificity 75.1%).Conclusions  If there is a threshold of blood glucose which defines a worse prognosis, it is at a higher level than the current definition of 2.2 mmol/l.
Ultrasound Guided Transplantation of Enriched and Cryopreserved Spermatogonial Cell Suspension in Goats
Authors: Kaul G , Kaur J , Rafeeqi TA 
Published: December 2009

ContentsSpermatogonial stem cells transplantation provides a unique approach for studying spermatogenesis. Initially developed in mice, this technique has now been extended in farm animals and provides an alternative means to preserve valuable male germ line and to produce transgenic animals. The aim of this study was to enrich type A spermatogonial cells amongst the isolated cells from goat testis, to cryopreserve these enriched populations of cells and their subsequent transplantation in unrelated recipient goats under ultrasound guidance. The cells were isolated enzymatically and enriched by differential plating and separation on discontinuous percoll gradient. Ultrasound guided injection of trypan blue dye into rete testis resulted in 20–30% filling of the seminiferous tubules. Prior to transplantation, the cells were labelled with a fluorescent dye to trace donor cells in recipient seminiferous tubules after transplantation. The fluorescent‐labelled cells were observed up to 12 weeks after transplantation.
Study of Botulinum Toxin A in Neurogenic Bladder Due to Spina Bifida in Children
Authors: Deshpande Aniruddh V. , Sampang Rico , Smith Grahame H. H. 
Published: December 2009

AbstractBackground:  We report results of a pilot study investigating the safety and efficacy of Botulinum A toxin on urinary incontinence and bladder function in children with neurogenic bladder.Methods:  This was a prospective, non‐randomized clinical trial. Seven children with median age of 16 years with spina bifida who had high storage pressures, poor bladder compliance and had failed treatment with anticholinergic medications were offered a single intra‐detrusor injection of Botulinum A toxin. All subjects were on clean intermittent catheterization before and during the study. Follow‐up videourodynamic studies were performed at 1 month, between 3 and 6 months, and at 9 months. Data were collected on safety and on subjective outcomes through validated questionnaires filled out by patients at each visit.Results:  In majority of the patients (5/7), the injection produced an increase in bladder compliance (P < 0.05) and an improvement in incontinence (P < 0.05) at 1‐month follow‐up. However, in two patients whose baseline bladder capacity was markedly reduced (<200 mL), the improvement was very minimal. The beneficial effects in bladder compliance and incontinence dissipated by 9 months. The changes in subjective outcomes (incontinence and satisfaction scores) did not parallel the changes in urodynamics through the study period. No side effects of Botulinum toxin were seen.Conclusion:  Botulinum A toxin injection produces beneficial urodynamics and clinical effects. These beneficial effects last for approximately 9 months. There is a poor correlation between improvement in the urodynamics and the subjective outcomes. Botulinum A toxin injection is a safe alternative treatment for patients with spina bifida and a neurogenic bladder.
Nasopharyngeal carcinoma: differences in presentation between different ethnicities in the New Zealand setting
Authors: Ianovski Ilia , Izzard Mark , Morton Randall P. , Plank Lindsay D. 
Published: December 2009

AbstractIntroduction:  There is an elevated incidence of nasopharyngeal carcinoma (NPC) in the Maori and Pacific Island (MPI) population as well as the Asian population in New Zealand; however, no studies have been conducted to evaluate how the two populations differ in their clinical presentation according to the TNM stage.Methods:  A retrospective review was conducted of all patients presenting to the Auckland City Hospital ENT department with a newly diagnosed NPC between the years 1995 and 2007 inclusive. The patient's radiological and biopsy results were reviewed, and each patient was staged according to the TNM stage at presentation as per the revised 2002 American Joint Committee on Cancer staging criteria. The Fisher's exact test was used to compare the differences between ethnicities in the T and N stages of the disease at presentation; the Cochran–Armitage Trend test was used to look for statistically significant trends.Results:  There was a statistically significant difference in T stage at presentation between MPIs and Asians (P < 0.0001), with a positive, statistically significant (P < 0.0001) trend indicating that MPIs present with greater T stage. A statistically significant difference in the N stage at diagnosis between MPIs and Asians, independent of the T stage, was found at stages T2 (P= 0.046) and T4 (P= 0.0083), with a statistically significant trend (T2 –P= 0.009; T4 –P= 0.026).Conclusions:  These results show that MPIs have a more advanced local NPC disease than Asians at presentation, and that for specific T stages, the nodal disease is also more advanced than that found in Asians.
CD38 as a prognostic marker in chronic lymphocytic leukaemia at a single New Zealand centre: patient survival in comparison to age‐ and sex‐matched population data
Authors: Hock B. D. , McKenzie J. L. , McArthur L. , Tansley S. , Taylor K. G. , Fernyhough L. J. 
Published: December 2009

AbstractAim: The aim of this study is to determine whether the analysis of CD38 expression by chronic lymphocytic leukaemia (CLL) cells provides useful additional prognostic information.Methods: Clinical, laboratory, overall survival (OS) and treatment‐free survival (TFS) data were collected on 130 CLL patients who had CD38 expression analysed at Canterbury Health Laboratories, New Zealand (NZ) during 1998–2008.Results: The detection of any level of CD38 expression by CLL cells was associated with a significantly shorter OS and TFS. When analysis was restricted to Binet stage A patients, CD38 expression identified a subset of patients (21%) who, in common with Binet stage B/C patients, had a significantly shorter OS and TFS (P < 0.0015), and a TFS at 4 years of <10%. In contrast, CD38‐negative Binet stage A patients had an OS that was not significantly different from that of an age/sex‐matched NZ population and a 5‐year TFS of 77%.Conclusion: This study indicates that, when combined with clinical staging, the presence of any detectable CD38 expression can be used to further improve the identification of CLL patients with more aggressive disease (i.e. Binet stage B/C or Binet stage A and CD38 positive). This will allow better identification of those patients requiring more intensive monitoring and also allow improved patient counselling regarding prognosis.