bluuebunny/crossref_metadata_2025_split huggingface dataset:
Endothelin (ET)‐1 and ET‐3 promote expression ofc‐fosandc‐junin human choriocarcinoma via ETBreceptor‐mediated Gi‐ and Gq‐pathways and MAP kinase activation
Authors: Rauh A , Windischhofer W , Kovacevic A , DeVaney T , Huber E , Semlitsch M , Leis H‐J , Sattler W , Malle E 
Published: March 2008

Background and purpose:Endothelins (ETs) and their G protein‐coupled receptors exert key physiological functions during normal and aberrant placental development. Trophoblast cells mediate the contact between the embryo and the mother, by establishing a transient organ, the placenta. Choriocarcinoma cells display many of the biochemical and morphological characteristics ofin uteroinvasive trophoblast cells and may therefore be used as a suitable model to study epithelial tumour progression of foetal‐derived cells.Experimental approach:The present study aimed at investigating ET receptor‐mediated activation of the mitogen‐activated protein kinase (MAPK) pathway in human choriocarcinoma.Key results:Both JAR and Jeg‐3 choriocarcinoma cell lines expressedET receptor subtype B(ETB) but notETAreceptor transcripts. ETBreceptor engagement by ET‐1 and ET‐3 resulted in a similar time‐ and concentration‐dependent phosphorylation of p42/44 MAPK, also known as extracellular regulated kinase 1/2. Using specific pharmacological antagonists/inhibitors, we showed that ET‐1/‐3‐mediated signal transduction by the ETBreceptor is transmitted via Gi‐ and Gq‐dependent pathways through activation of the Src (Gi) and protein kinase C (Gq) axis that converge at Ras/Raf, leading to downstream activation of p42/44. On a functional level, ETBengagement and subsequent phosphorylation of p42/44 resulted in enhanced transcription of the immediate early response genesc‐fosandc‐jun, a process commonly assumed to be mediated by the ETAreceptor, and increased cell growth and relative cell area.Conclusions and implications:As human choriocarcinoma cells secrete ETs, pharmacological antagonism of ETs and/or ETBreceptor‐mediated signal transduction could represent a likely target therapy for choriocarcinoma.
Amino Acid Substitutions in Homologs of the STAY-GREEN Protein Are Responsible for thegreen-fleshandchlorophyll retainerMutations of Tomato and Pepper
Authors: Barry Cornelius S. , McQuinn Ryan P. , Chung Mi-Young , Besuden Anna , Giovannoni James J. 
Published: March 2008

AbstractColor changes often accompany the onset of ripening, leading to brightly colored fruits that serve as attractants to seed-dispersing organisms. In many fruits, including tomato (Solanum lycopersicum) and pepper (Capsicum annuum), there is a sharp decrease in chlorophyll content and a concomitant increase in the synthesis of carotenoids as a result of the conversion of chloroplasts into chromoplasts. The green-flesh (gf) and chlorophyll retainer (cl) mutations of tomato and pepper, respectively, are inhibited in their ability to degrade chlorophyll during ripening, leading to the production of ripe fruits characterized by both chlorophyll and carotenoid accumulation and are thus brown in color. Using a positional cloning approach, we have identified a point mutation at the gf locus that causes an amino acid substitution in an invariant residue of a tomato homolog of the STAY-GREEN (SGR) protein of rice (Oryza sativa). Similarly, the cl mutation also carries an amino acid substitution at an invariant residue in a pepper homolog of SGR. Both GF and CL expression are highly induced at the onset of fruit ripening, coincident with the ripening-associated decline in chlorophyll. Phylogenetic analysis indicates that there are two distinct groups of SGR proteins in plants. The SGR subfamily is required for chlorophyll degradation and operates through an unknown mechanism. A second subfamily, which we have termed SGR-like, has an as-yet undefined function.
Diversity and functions of leaf‐decaying fungi in human‐altered streams
Authors: LECERF ANTOINE , CHAUVET ERIC 
Published: March 2008

Summary1. Stream conditions have been evaluated using leaf breakdown, and aquatic hyphomycetes are a diverse group of fungal decomposers which contribute to this process.2. In field surveys of three pairs of impact‐control stream sites we assessed the effect of eutrophication, mine pollution and modification of riparian vegetation on alder leaf breakdown rate in coarse and fine mesh bags and on mycelial biomass, spore production and species diversity of leaf‐colonizing fungi.3. In addition, we gathered published information on the response of leaf‐colonizing fungi to these three types of perturbations. We conducted a meta‐analysis of 23 published papers to look for consistent patterns across studies and to determine the relevance of four fungal‐based metrics (microbial breakdown rate, maximum spore production, maximum mycelial biomass and total species richness) to detect stream impairment.4. In our field surveys, leaf breakdown rates in coarse mesh bags were lower at impact than at paired control sites regardless of perturbation type. A similar trend was observed for leaf breakdown rates in fine mesh bags. Mycelial biomass and spore production were higher in the eutrophied stream than in the control stream. Spore production was depressed in the mine polluted stream, while it was slightly enhanced in the stream affected by forestry. Fungal diversity tended to be lower at impact than at paired control sites, though the mean and cumulative species richness values were often inconsistent.5. Results of the meta‐analysis confirmed that mine pollution reduces fungal diversity and performance. Eutrophication was not found to affect microbial breakdown rate, maximum spore production and maximum mycelial biomass in a predictable manner because both positive and negative effects were reported in the literature. However, fungal species richness was consistently reduced in eutrophied streams. Modification of riparian vegetation had at most a small stimulating effect on maximum spore production. Among the four fungal‐based metrics included in the meta‐analysis, maximum spore production emerged as the most sensitive indicator of human impact on streams.6. Taken together, our findings indicate that human activities can affect the diversity and functions of aquatic hyphomycetes in streams. We also show that leaf breakdown rate and simple fungal‐based metrics, such as spore production, are relevant to assess stream condition.
Conserved residues of the C‐terminal p16 domain of primase are involved in modulating the activity of the bacterial primosome
Authors: Chintakayala Kiran , Larson Marilynn A. , Griep Mark A. , Hinrichs Steven H. , Soultanas Panos 
Published: March 2008

SummaryThe bacterial primosome comprises the replicative homo‐hexameric ring helicase DnaB and the primase DnaG. It is an integral component of the replisome as it unwinds the parental DNA duplex to allow progression of the replication fork, synthesizes the initiation primers at the replication origin, oriC, and the primers required for Okazaki fragment synthesis during lagging strand replication. The interaction between the two component proteins is mediated by a distinct C‐terminal domain (p16) of the primase. Both proteins mutually regulate each other's activities and a putative network of conserved residues has been proposed to mediate these effects. We have targeted 10 residues from this network. To investigate the functional contributions of these residues to the primase, ATPase and helicase activities of the primosome, we have used site‐directed mutagenesis and in vitro functional assays. Five of these residues (E464, H494, R495, Y548 and R555) exhibited some functional significance while the remaining five (E483, R484, E506, D512 and E530) exhibited no effects. E464 participates in functional modulation of the primase activity, whereas H494, R495 and R555 participate in allosteric functional modulation of the ATPase and/or helicase activities. Y548 contributes directly to the structural interaction with DnaB.
Effects of geological complexities on coseismic displacement: hints from 2D numerical modelling
Authors: Megna A. , Barba S. , Santini S. , Dragoni M. 
Published: March 2008

AbstractBy means of a 2D finite‐element procedure, we tested how heterogeneities at the scale of seismogenic fault affect the displacement. We defined one or more slip distributions for two typical normal‐faulting earthquakes in the Central Apennines, computed the displacement occurred within different structures including lateral heterogeneities, and compared the different displacement profiles to isolate the effect of the crustal structure. To understand at what magnitude the heterogeneities affect the observation significantly, we compared the predicted coseismic displacement with GPS and DInSAR data for the Colfiorito 1997 earthquake. We find that heterogeneities significantly affect the observable horizontal coseismic displacement for the larger magnitudes, whereas for smaller quakes, they affect horizontal displacement close to the fault trace only.
Assessment of Selected Quality Parameters of Epididymal Cat (Felis catus s. domestica, L. 1758) Sperm Using Flow Cytometry Method and Computer Assisted Sperm Analyser
Authors: Siemieniuch MJ , Woclawek‐Potocka I 
Published: March 2008

ContentsThe improvement of biotechnical methods connected with fast and precise semen quality assessment and its utilization in assisted reproductive techniques is an urgent necessity in felids. The aim of this study was to evaluate some quality parameters (i.e. the viability and share of cells with intact plasma membrane) of epididymal sperm of cats using the flow cytometry method and computer‐assisted sperm analysis (CASA) examination. The material consisted of epididymal spermatozoa flushed from 22 pairs of epididymes after routine neutering procedures obtained from domestic cats aged between 8 and 36 months. The epididymes were cut and incubated with an extender without egg yolk. The samples were assessed for sperm viability (Live/Dead Sperm Viability Kit®), percentage of subtle membrane changes (Apoptosis Detection Kit®) and motility using FACScalibur flow cytometer and assisted sperm analyser htm ivos version 12.2. The flow cytometry method revealed 71.3% and 84.4% of live sperm using Live/Dead Sperm Viability Kit and Apoptosis Detection Kit respectively. The population of early‐apoptotic and late‐apoptotic sperm were 0.8% and 1.1% respectively. The CASA examination found 51.5% of motile sperm. However, the motility examination under light microscope revealed 69.5% of motile sperm. The data revealed an indistinctive per cent of apoptotic cells and 18.9% and 15.6% of dead cells using Live/Dead Sperm Viability Kit and Apoptosis Detection Kit, respectively, which indicate that the sperm obtained after flushing the epididymis possess potential properties for further assisted reproduction techniques.
The Role of Platelet‐activating Factor in the Mammalian Female Reproductive Tract
Authors: Tiemann U 
Published: March 2008

ContentsPlatelet‐activating factor (PAF) is a potent lipid mediator produced by various cell types of mammals and is involved in an inflammatory‐like process with increased vascular permeability. Platelet‐activating factor exerts its actions through the activation of specific PAF receptors (PAF‐R) found in cells and tissues of the female reproductive tract. The aim of this article was summarized briefly in the current research on the role of PAF in female reproductive functions. Platelet‐activating factor has been implicated in processes of ovulation, implantation and parturition because of its angiogenic and growth factor properties. This factor is influenced by ovarian steroid hormones in bringing about changes in the uterus and is a candidate molecule for initial embryo–maternal dialogue. Tissue concentrations of PAF are regulated by the equilibrium between biosynthesis and degradation by PAF‐acetylhydrolase (PAF‐AH). Antagonists of PAF interfere with ovulation and implantation. Platelet‐activating factor, its receptor, and PAF‐AH activity play an important role in the maintenance of pregnancy.
MINOR PAPILLA SPHINCTEROTOMY FOR PANCREATITIS DUE TO PANCREAS DIVISUM
Authors: Kwan Vu , Loh Sze M. , Walsh Patrick R. , Williams Stephen J. , Bourke Michael J. 
Published: March 2008

Background:  Pancreas divisum (PD) is the commonest congenital pancreatic abnormality and is implicated as a cause of acute recurrent pancreatitis (ARP). We report our experience in minor papilla sphincterotomy (MPS) for this condition. Studies published at present have not examined MPS as the primary treatment method in a homogenous (i.e. only those with ARP) patient group.Methods:  Patients with PD and ARP were identified from an endoscopic database. Treatment protocol consisted of minor papilla guidewire cannulation and sphincterotomy with either sphincterotome over the wire or needle knife over pancreatic stent. A 5‐Fr stent was placed for 1 week. Adjunctive therapy was carried out as required. Follow‐up data was collected by interview with the patient and referring doctors and review of the medical record.Results:  Twenty‐one patients underwent MPS for PD and ARP (median age = 33 years, range 9–77 years, men = 14). Median number of procedures to achieve cannulation and MPS was 1 (range 1–3). Complications encountered were pancreatitis (n = 2) and pain (n = 3). MPS restenosis occurred in 2. Adjuvant therapy was required in 14: stricture dilatation (n = 9), stone extraction (n = 7) and extracorporeal shock‐wave lithotripsy (n = 6). Complete stone clearance was achieved in 7/7. Median follow up was 38 months (range 4–67 months). Median total number of pancreatitis episodes and hospitalizations pre‐MPS were 4 and 2, respectively (range 1–20 and 0–5, respectively). Post‐MPS these were reduced to 0 and 0, respectively (range 0–8 and 0–4; P = 0.0007 and P = 0.0003), with complete abolition of episodes in 13 patients.Conclusion:  MPS in association with other endoscopic therapies imparts a significant clinical benefit to patients with ARP and PD. Complete clinical resolution occurs in the majority. Treatment is safe, and the response is durable.
DESMOPLASTIC MELANOMA: THE ROLE OF RADIOTHERAPY IN IMPROVING LOCAL CONTROL
Authors: Foote Matthew C. , Burmeister Bryan , Burmeister Elizabeth , Bayley Gerard , Smithers B Mark 
Published: March 2008

Background:  Desmoplastic melanoma (DM) is a rare subtype of cutaneous malignant melanoma reported to have a high local recurrence rate with surgical excision alone. The incidence of regional and distant metastasis is considered to be lower than traditional cutaneous melanoma, warranting more aggressive treatment of local disease. We conducted a retrospective analysis of patients with DM treated through the Princess Alexandra Hospital Melanoma Clinic to address the role of radiotherapy in the local control of this tumour.Methods:  A review of a clinical database identified 24 patients between January 1997 and March 2006 with histopathologically confirmed DM who had received surgical excision as initial treatment followed by postoperative radiotherapy. All histopathology reports and radiotherapy treatment plans were reviewed. The primary outcome measure was 3‐year in‐field relapse‐free survival.Results:  There were 24 patients with 22 having a DM in the head and neck region. The median tumour thickness was 5.2 mm. The histopathological margin was less than 10 mm in 17 (71%) of patients. The 3‐year in‐field relapse‐free survival was 91% (95% confidence interval 68.1–97.6%), the 3‐year relapse‐free survival was 86% (95% confidence interval 63.2–95.4%) with a 3‐year overall survival of 83% (95% confidence interval 54.9–94.3%).Conclusion:  In a selected series of patients with DM with a high risk of local recurrence, adjuvant radiotherapy may have been effective in reducing the rate of local recurrence after surgical resection. A randomized trial is currently being developed to confirm this possible benefit.
Long‐term observation of a pollination network: fluctuation in species and interactions, relative invariance of network structure and implications for estimates of specialization
Authors: Petanidou Theodora , Kallimanis Athanasios S. , Tzanopoulos Joseph , Sgardelis Stefanos P. , Pantis John D. 
Published: March 2008

AbstractWe analysed the dynamics of a plant–pollinator interaction network of a scrub community surveyed over four consecutive years. Species composition within the annual networks showed high temporal variation. Temporal dynamics were also evident in the topology of the network, as interactions among plants and pollinators did not remain constant through time. This change involved both the number and the identity of interacting partners. Strikingly, few species and interactions were consistently present in all four annual plant–pollinator networks (53% of the plant species, 21% of the pollinator species and 4.9% of the interactions). The high turnover in species‐to‐species interactions was mainly the effect of species turnover (c. 70% in pairwise comparisons among years), and less the effect of species flexibility to interact with new partners (c. 30%). We conclude that specialization in plant–pollinator interactions might be highly overestimated when measured over short periods of time. This is because many plant or pollinator species appear as specialists in 1 year, but tend to be generalists or to interact with different partner species when observed in other years. The high temporal plasticity in species composition and interaction identity coupled with the low variation in network structure properties (e.g. degree centralization, connectance, nestedness, average distance and network diameter) imply (i) that tight and specialized coevolution might not be as important as previously suggested and (ii) that plant–pollinator interaction networks might be less prone to detrimental effects of disturbance than previously thought. We suggest that this may be due to the opportunistic nature of plant and animal species regarding the available partner resources they depend upon at any particular time.
Physiology, phylogeny and in situ evidence for bacterial and archaeal nitrifiers in the marine sponge Aplysina aerophoba
Authors: Bayer Kristina , Schmitt Susanne , Hentschel Ute 
Published: March 2008

SummaryThe potential for nitrification in the Mediterranean sponge Aplysina aerophoba was assessed using a combined physiological and molecular approach. Nitrate excretion rates in whole sponges reached values of up to 344 nmol g−1 dry weight (wt) h−1 (unstimulated) and 1325 nmol g−1 dry wt h−1 (stimulated). Addition of nitrapyrin, a nitrification‐specific inhibitor, effectively inhibited nitrate excretion. Ammonium was taken up by sponges in spring and excreted in fall, the sponges thus serving as either an ammonium sink or ammonium source. Nitrosospira cluster 1 and Crenarchaeota group I.1A 16S rRNA and amoA genes were recovered from A. aerophoba and other sponges from different world's oceans. The archaeal 16S rRNA genes formed a sponge‐specific subcluster, indicating that their representatives are members of the stable microbial community of sponges. On the other hand, clustering was not evident for Nitrosospira rRNA genes which is consistent with their presence in sediment and seawater samples. The presence of both Nitrosospira cluster 1 and crenarchaeal group 1 phylotypes in sponge tissue was confirmed using fluorescently labelled 16S rRNA gene probes. This study contributes to an ongoing effort to link microbial diversity with metabolic functions in the phylogenetically diverse, elusive and so far uncultivated microbial communities of marine sponges.
Alcohol use among HIV‐infected persons in care: results of a multi‐site survey*
Authors: Chander G , Josephs J , Fleishman JA , Korthuis PT , Gaist P , Hellinger J , Gebo K ,   for the HIV Research Network
Published: March 2008

ObjectiveWe sought to determine the prevalence of any alcohol use and hazardous alcohol consumption among HIV‐infected individuals engaged in care and to identify factors associated with hazardous alcohol use.MethodsDuring 2003, 951 patients were interviewed at 14 HIV primary care sites in the USA. Hazardous drinking was defined as >14 drinks/week or ≥5 drinks/occasion for men and >7 drinks/week or ≥4 drinks/occasion for women. Moderate alcohol use was consumption at less than hazardous levels. We used logistic regression to identify factors associated with any alcohol use and hazardous alcohol use.ResultsForty per cent of the sample reported any alcohol use in the 4 weeks prior to the interview; 11% reported hazardous use. In multivariate regression, male sex [adjusted odds ratio (AOR) 1.52 (95% confidence interval, CI, 1.07–2.16)], a college education (compared to<high school) [AOR 1.87 (1.10–3.18)] and illicit drug use [AOR 2.69 (1.82–3.95)] were associated positively with any alcohol use, while CD4 nadir ≥500 cells/μL [AOR 2.65 (1.23–5.69)] and illicit drug use [AOR 2.67 (1.48–4.82)] were associated with increased odds of hazardous alcohol use (compared to moderate and none).ConclusionsAlcohol use is prevalent among HIV‐infected individuals and is associated with a variety of socioeconomic and demographic characteristics. Screening for alcohol use should be routine practice in HIV primary care settings.
The changing pattern of tuberculosis and HIV co‐infection in immigrants and Spaniards in the last 20 years
Authors: Velasco M , Castilla V , Cervero M , Sanz J , Condes E , Gaspar G , Torres R , Arranz A , Barros C , Monereo A ,   for the COMESEM cohort
Published: March 2008

ObjectivesTo evaluate the impact of immigration on tuberculosis (TB)–HIV co‐infection in Spain in a prospective cohort of HIV patients.MethodsAmong 7761 HIV patients, we evaluated 1284 with at least one episode of TB between 1987 and 2006. Variables were compared between immigrants and Spaniards.ResultsIncidence of TB decreased from 20 to five cases per 100 patient‐years in 2006 (P<0.01) and was always higher in immigrants than in Spaniards. The proportion of immigrants increased, reaching almost 50% of both new cases of HIV and TB–HIV co‐infection in 2006. In 34.4% of patients, TB and HIV infection were diagnosed within the same year; simultaneous diagnosis was more frequent in immigrants (83.3%vs. 16.7%, P<0.001). Mortality was associated independently with age [hazard ratio (HR) 1.03, 95% confidence interval (CI) 1.01–1.05], TB diagnosis before 1996 (HR 2.6, 95% CI 1.8–3.6), use of highly active antiretroviral treatment (HR 0.494, 95% CI 0.37–0.66) and CD4 cell count at TB diagnosis (HR 0.996, 95% CI 0.995–0.997).ConclusionsImmigrants have a major impact on the incidence of TB in HIV patients, slowing down the decreasing trend in Spain. Simultaneous diagnosis of the co‐infection in immigrants reveals a need to intensify HIV case finding in immigrants in Spain.