bluuebunny/crossref_metadata_2025 huggingface dataset:
Common and unique elements of the ABA-regulated transcriptome of Arabidopsis guard cells
Authors: Wang Rui-Sheng , Pandey Sona , Li Song , Gookin Timothy E , Zhao Zhixin , Albert Réka , Assmann Sarah M
Published: May 2011

Background

In the presence of drought and other desiccating stresses, plants synthesize and redistribute the phytohormone abscisic acid (ABA). ABA promotes plant water conservation by acting on specialized cells in the leaf epidermis, guard cells, which border and regulate the apertures of stomatal pores through which transpirational water loss occurs. Following ABA exposure, solute uptake into guard cells is rapidly inhibited and solute loss is promoted, resulting in inhibition of stomatal opening and promotion of stomatal closure, with consequent plant water conservation. There is a wealth of information on the guard cell signaling mechanisms underlying these rapid ABA responses. To investigate ABA regulation of gene expression in guard cells in a systematic genome-wide manner, we analyzed data from global transcriptomes of guard cells generated with Affymetrix ATH1 microarrays, and compared these results to ABA regulation of gene expression in leaves and other tissues.

Results

The 1173 ABA-regulated genes of guard cells identified by our study share significant overlap with ABA-regulated genes of other tissues, and are associated with well-defined ABA-related promoter motifs such as ABREs and DREs. However, we also computationally identified a uniquecis-acting motif, GTCGG, associated with ABA-induction of gene expression specifically in guard cells. In addition, approximately 300 genes showing ABA-regulation unique to this cell type were newly uncovered by our study. Within the ABA-regulated gene set of guard cells, we found that many of the genes known to encode ion transporters associated with stomatal opening are down-regulated by ABA, providing one mechanism for long-term maintenance of stomatal closure during drought. We also found examples of both negative and positive feedback in the transcriptional regulation by ABA of known ABA-signaling genes, particularly with regard to the PYR/PYL/RCAR class of soluble ABA receptors and their downstream targets, the type 2C protein phosphatases. Our data also provide evidence for cross-talk at the transcriptional level between ABA and another hormonal inhibitor of stomatal opening, methyl jasmonate.

Conclusions

Our results engender new insights into the basic cell biology of guard cells, reveal common and unique elements of ABA-regulation of gene expression in guard cells, and set the stage for targeted biotechnological manipulations to improve plant water use efficiency.
Analysis of anther transcriptomes to identify genes contributing to meiosis and male gametophyte development in rice
Authors: Deveshwar Priyanka , Bovill William D , Sharma Rita , Able Jason A , Kapoor Sanjay
Published: May 2011

Background

In flowering plants, the anther is the site of male gametophyte development. Two major events in the development of the male germline are meiosis and the asymmetric division in the male gametophyte that gives rise to the vegetative and generative cells, and the following mitotic division in the generative cell that produces two sperm cells. Anther transcriptomes have been analyzed in many plant species at progressive stages of development by using microarray and sequence-by synthesis-technologies to identify genes that regulate anther development. Here we report a comprehensive analysis of rice anther transcriptomes at four distinct stages, focusing on identifying regulatory components that contribute to male meiosis and germline development. Further, these transcriptomes have been compared with the transcriptomes of 10 stages of rice vegetative and seed development to identify genes that express specifically during anther development.

Results

Transcriptome profiling of four stages of anther development in rice including pre-meiotic (PMA), meiotic (MA), anthers at single-celled (SCP) and tri-nucleate pollen (TPA) revealed about 22,000 genes expressing in at least one of the anther developmental stages, with the highest number in MA (18,090) and the lowest (15,465) in TPA. Comparison of these transcriptome profiles to an in-house generated microarray-based transcriptomics database comprising of 10 stages/tissues of vegetative as well as reproductive development in rice resulted in the identification of 1,000 genes specifically expressed in anther stages. From this sub-set, 453 genes were specific to TPA, while 78 and 184 genes were expressed specifically in MA and SCP, respectively. The expression pattern of selected genes has been validated using real time PCR and in situ hybridizations. Gene ontology and pathway analysis of stage-specific genes revealed that those encoding transcription factors and components of protein folding, sorting and degradation pathway genes dominated in MA, whereas in TPA, those coding for cell structure and signal transduction components were in abundance. Interestingly, about 50% of the genes with anther-specific expression have not been annotated so far.

Conclusions

Not only have we provided the transcriptome constituents of four landmark stages of anther development in rice but we have also identified genes that express exclusively in these stages. It is likely that many of these candidates may therefore contribute to specific aspects of anther and/or male gametophyte development in rice. In addition, the gene sets that have been produced will assist the plant reproductive community in building a deeper understanding of underlying regulatory networks and in selecting gene candidates for functional validation.
mRNA transcript quantification in archival samples using multiplexed, color-coded probes
Authors: Reis Patricia P , Waldron Levi , Goswami Rashmi S , Xu Wei , Xuan Yali , Perez-Ordonez Bayardo , Gullane Patrick , Irish Jonathan , Jurisica Igor , Kamel-Reid Suzanne
Published: May 2011

Background

A recently developed probe-based technology, the NanoString nCounter™ gene expression system, has been shown to allow accurate mRNA transcript quantification using low amounts of total RNA. We assessed the ability of this technology for mRNA expression quantification in archived formalin-fixed, paraffin-embedded (FFPE) oral carcinoma samples.

Results

We measured the mRNA transcript abundance of 20 genes (COL3A1, COL4A1, COL5A1, COL5A2, CTHRC1, CXCL1, CXCL13, MMP1, P4HA2, PDPN, PLOD2, POSTN, SDHA, SERPINE1, SERPINE2, SERPINH1, THBS2, TNC, GAPDH, RPS18) in 38 samples (19 paired fresh-frozen and FFPE oral carcinoma tissues, archived from 1997-2008) by both NanoString and SYBR Green I fluorescent dye-based quantitative real-time PCR (RQ-PCR). We compared gene expression data obtained by NanoString vs. RQ-PCR in both fresh-frozen and FFPE samples. Fresh-frozen samples showed a good overall Pearson correlation of 0.78, and FFPE samples showed a lower overall correlation coefficient of 0.59, which is likely due to sample quality. We found a higher correlation coefficient between fresh-frozen and FFPE samples analyzed by NanoString (r = 0.90) compared to fresh-frozen and FFPE samples analyzed by RQ-PCR (r = 0.50). In addition, NanoString data showed a higher mean correlation (r = 0.94) between individual fresh-frozen and FFPE sample pairs compared to RQ-PCR (r = 0.53).

Conclusions

Based on our results, we conclude that both technologies are useful for gene expression quantification in fresh-frozen or FFPE tissues; however, the probe-based NanoString method achieved superior gene expression quantification results when compared to RQ-PCR in archived FFPE samples. We believe that this newly developed technique is optimal for large-scale validation studies using total RNA isolated from archived, FFPE samples.
Crystal structures of Burkholderia cenocepacia dihydropteroate synthase in the apo-form and complexed with the product 7,8-dihydropteroate
Authors: Morgan Rachel E , Batot Gaëlle O , Dement Jennifer M , Rao Vincenzo A , Eadsforth Thomas C , Hunter William N
Published: May 2011

Background

The enzyme dihydropteroate synthase (DHPS) participates in the de novo synthesis of folate cofactors by catalyzing the formation of 7,8-dihydropteroate from condensation of p-aminobenzoic acid with 6-hydroxymethyl-7,8-dihydropteroate pyrophosphate. DHPS is absent from humans, who acquire folates from diet, and has been validated as an antimicrobial therapeutic target by chemical and genetic means. The bacterium Burkholderia cenocepacia is an opportunistic pathogen and an infective agent of cystic fibrosis patients. The organism is highly resistant to antibiotics and there is a recognized need for the identification of new drugs against Burkholderia and related Gram-negative pathogens. Our characterization of the DHPS active site and interactions with the enzyme product are designed to underpin early stage drug discovery.

Results

An efficient recombinant protein expression system for DHPS from B. cenocepacia (Bc DHPS) was prepared, the dimeric enzyme purified in high yield and crystallized. The structure of the apo-enzyme and the complex with the product 7,8-dihydropteroate have been determined to 2.35 Å and 1.95 Å resolution respectively in distinct orthorhombic crystal forms. The latter represents the first crystal structure of the DHPS-pterin product complex, reveals key interactions involved in ligand binding, and reinforces data generated by other structural studies. Comparisons with orthologues identify plasticity near the substrate-binding pocket and in particular a range of loop conformations that contribute to the architecture of the DHPS active site. These structural data provide a foundation for hit discovery. An intriguing observation, an artifact of the analysis, that of a potential sulfenamide bond within the ligand complex structure is mentioned.

Conclusion

Structural similarities between Bc DHPS and orthologues from other Gram-negative species are evident as expected on the basis of a high level of sequence identity. The presence of 7,8-dihydropteroate in the binding site provides details about ligand recognition by the enzyme and the different states of the enzyme allow us to visualize distinct conformational states of loops adjacent to the active site. Improved drugs to combat infections by Burkholderia sp. and related Gram-negative bacteria are sought and our study now provides templates to assist that process and allow us to discuss new ways of inhibiting DHPS.
Population pharmacokinetics of artesunate and dihydroartemisinin in pregnant and non-pregnant women with malaria
Authors: Morris Carrie A , Onyamboko Marie A , Capparelli Edmund , Koch Matthew A , Atibu Joseph , Lokomba Vicky , Douoguih Macaya , Hemingway-Foday Jennifer , Wesche David , Ryder Robert W , Bose Carl , Wright Linda , Tshefu Antoinette K , Meshnick Steven , Fleckenstein Lawrence
Published: May 2011

Background

The World Health Organization endorses the use of artemisinin-based combination therapy for treatment of acute uncomplicated falciparum malaria in the second and third trimesters of pregnancy. However, the effects of pregnancy on the pharmacokinetics of artemisinin derivatives, such as artesunate (AS), are poorly understood. In this analysis, the population pharmacokinetics of oral AS, and its active metabolite dihydroartemisinin (DHA), were studied in pregnant and non-pregnant women at the Kingasani Maternity Clinic in the DRC.

Methods

Data were obtained from 26 pregnant women in the second (22 - 26 weeks) or the third (32 - 36 weeks) trimester of pregnancy and from 25 non-pregnant female controls. All subjects received 200 mg AS. Plasma AS and DHA were measured using a validated LC-MS method. Estimates for pharmacokinetic and variability parameters were obtained through nonlinear mixed effects modelling.

Results

A simultaneous parent-metabolite model was developed consisting of mixed zero-order, lagged first-order absorption of AS, a one-compartment model for AS, and a one-compartment model for DHA. Complete conversion of AS to DHA was assumed. The model displayed satisfactory goodness-of-fit, stability, and predictive ability. Apparent clearance (CL/F) and volume of distribution (V/F) estimates, with 95% bootstrap confidence intervals, were as follows: 195 L (139-285 L) for AS V/F, 895 L/h (788-1045 L/h) for AS CL/F, 91.4 L (78.5-109 L) for DHA V/F, and 64.0 L/h (55.1-75.2 L/h) for DHA CL/F. The effect of pregnancy on DHA CL/F was determined to be significant, with a pregnancy-associated increase in DHA CL/F of 42.3% (19.7 - 72.3%).

Conclusions

In this analysis, pharmacokinetic modelling suggests that pregnant women have accelerated DHA clearance compared to non-pregnant women receiving orally administered AS. These findings, in conjunction with a previous non-compartmental analysis of the modelled data, provide further evidence that higher AS doses would be required to maintain similar DHA levels in pregnant women as achieved in non-pregnant controls.
Patterns of chloroquine use and resistance in sub-Saharan Africa: a systematic review of household survey and molecular data
Authors: Frosch Anne EP , Venkatesan Meera , Laufer Miriam K
Published: May 2011

Background

As a result of widespread chloroquine and sulphadoxine-pyrimethamine (SP) resistance, 90% of sub-Saharan African countries had adopted policies of artemisinin-based combination therapy (ACT) for treatment of uncomplicated malaria by 2007. In Malawi, cessation of chloroquine use was followed by the re-emergence of chloroquine-susceptible malaria. It was expected that introduction of ACT would lead to a return in chloroquine susceptibility throughout Africa, but this has not yet widely occurred. This observation suggests that there is continuing use of ineffective anti-malarials in Africa and that persistent chloroquine-resistant malaria is due to ongoing drug pressure despite national policy changes.

Methods

To estimate drug use on a national level, 2006-2007 Demographic Health Survey and Multiple Indicator Cluster Survey data from 21 African countries were analysed. Resistance data were compiled by systematic review of the published literature on the prevalence of the Plasmodium falciparum chloroquine resistance transporter polymorphism at codon 76, which causes chloroquine resistance.

Results

Chloroquine was the most common anti-malarial used according to surveys from 14 of 21 countries analysed, predominantly in West Africa. SP was most commonly reported in two of 21 countries. Among eight countries with longitudinal molecular resistance data, the four countries where the highest proportion of children treated for fever received chloroquine (Uganda, Burkina Faso, Guinea Bissau, and Mali) also showed no significant declines in the prevalence of chloroquine-resistant infections. The three countries with low or decreasing chloroquine use among children who reported fever treatment (Malawi, Kenya, and Tanzania) had statistically significant declines in the prevalence of chloroquine resistance.

Conclusions

This study demonstrates that in 2006-2007, chloroquine and SP continued to be used at high rates in many African countries. In countries reporting sustained chloroquine use, chloroquine-resistant malaria persists. In contrast, a low level of estimated chloroquine use is associated with a declining prevalence of chloroquine resistance.
Biochemical properties of pancreatic colipase from the common stingray Dasyatis pastinaca
Authors: Ben Bacha Abir , Karray Aida , Daoud Lobna , Bouchaala Emna , Bou Ali Madiha , Gargouri Youssef , Ben Ali Yassine
Published: May 2011

Background

Pancreatic colipase is a required co-factor for pancreatic lipase, being necessary for its activity during hydrolysis of dietary triglycerides in the presence of bile salts. In the intestine, colipase is cleaved from a precursor molecule, procolipase, through the action of trypsin. This cleavage yields a peptide called enterostatin knoswn, being produced in equimolar proportions to colipase.

Results

In this study, colipase from the common stingray Dasyatis pastinaca (CoSPL) was purified to homogeneity. The purified colipase is not glycosylated and has an apparent molecular mass of around 10 kDa. The NH2-terminal sequencing of purified CoSPL exhibits more than 55% identity with those of mammalian, bird or marine colipases. CoSPL was found to be less effective activator of bird and mammal pancreatic lipases than for the lipase from the same specie. The apparent dissociation constant (Kd) of the colipase/lipase complex and the apparent Vmax of the colipase-activated lipase values were deduced from the linear curves of the Scatchard plots. We concluded that Stingray Pancreatic Lipase (SPL) has higher ability to interact with colipase from the same species than with the mammal or bird ones.

Conclusion

The fact that colipase is a universal lipase cofactor might thus be explained by a conservation of the colipase-lipase interaction site. The results obtained in the study may improve our knowledge of marine lipase/colipase.
The CTGF -945GC polymorphism is not associated with plasma CTGF and does not predict nephropathy or outcome in type 1 diabetes
Authors: Dendooven Amélie , Nguyen Tri Q , Brosens Lodewijk , Li Dongxia , Tarnow Lise , Parving Hans-Henrik , Rossing Peter , Goldschmeding Roel
Published: May 2011

The -945GC polymorphism (rs6918698) in the connective tissue growth factor gene promoter (CTGF/CCN-2) has been associated with end organ damage in systemic sclerosis. Because CTGF is important in progression of diabetic kidney disease, we investigated whether the -945GC polymorphism is associated with plasma CTGF level and outcome in type 1 diabetes.

The study cohort consisted of 448 diabetic nephropathy patients and 419 normoalbuminuric diabetic patients with complete data concerning renal function and cardiovascular characteristics. Genomic DNA was genotyped by a QPCR-based SNP assay. We observed no relation between the -945GC polymorphism and plasma CTGF level, and the genotype frequencies were not different in nephropathy patients vs. normoalbuminuric controls. General and cardiovascular mortality, and renal function decline was similar in patients with CC, CG or GG genotypes.

In conclusion, the -945GC SNP does not affect plasma CTGF levels, incidence and prognosis of diabetic nephropathy, and cardiovascular outcome.
Structural and histological characterization of oviductal magnum and lectin-binding patterns in Gallus domesticus
Authors: Jung Jin Gyoung , Lim Whasun , Park Tae Sub , Kim Jin Nam , Han Beom Ku , Song Gwonhwa , Han Jae Yong
Published: May 2011

Background

Although chicken oviduct is a useful model and target tissue for reproductive biology and transgenesis, little is known because of the highly specific hormonal regulation and the lack of fundamental researches, including lectin-binding activities and glycobiology. Because lectin is attached to secreted glycoproteins, we hypothesized that lectin could be bound to secretory egg-white proteins, and played a crucial role in the generation of egg-white protein in the oviduct. Hence, the purpose of this study was to investigate the structural, histological and lectin-binding characteristics of the chicken oviductal magnum from juvenile and adult hens.

Methods

The oviductal magnums from juvenile and adult hens were prepared for ultrastructural analysis, qRT-PCR and immunostaining. Immunohistochemistry of anti-ovalbumin, anti-ESR1 and anti-PGR, and mRNA expression of egg-white genes and steroid hormone receptor genes were evaluated. Lectin histochemical staining was also conducted in juvenile and adult oviductal magnum tissues.

Results

The ultrastructural analysis showed that ciliated cells were rarely developed on luminal surface in juvenile magnum, but not tubular gland cells. In adult magnum, two types of epithelium and three types of tubular gland cells were observed. qRT-PCR analysis showed that egg-white genes were highly expressed in adult oviduct compared with the juvenile. However, mRNA expressions of ESR1 and PGR were considerably higher in juvenile oviduct than adult (P < 0.05). The immunohistochemical analysis showed that anti-ovalbumin antibody was detected in adult oviduct not in juvenile, unlikely anti-ESR1 and anti-PGR antibodies that were stained in both oviducts. In histological analysis, Toluidine blue was stained in juvenile and adult oviductal epithelia, and adult tubular glands located in the outer layer of oviductal magnum. In contrast, PAS was positive only in adult oviductal tubular gland. Lectins were selectively bound to oviductal epithelium, stroma, and tubular gland cells. Particularly, lectin-ConA and WGA were bound to electron-dense secretory granules in tubular gland.

Conclusions

The observation of ultrastructural analysis, mRNA expression, immunohistochemistry and lectin staining showed structural and physiological characterization of juvenile and adult oviductal magnum. Consequently, oviduct study could be helped to in vitro culture of chicken oviductal cells, to develop epithelial or tubular gland cell-specific markers, and to understand female reproductive biology and endocrinology.
Modeling left ventricular diastolic dysfunction: classification and key indicators
Authors: Luo Chuan , Ramachandran Deepa , Ware David L , Ma Tony S , Clark John W
Published: May 2011

Background

Mathematical modeling can be employed to overcome the practical difficulty of isolating the mechanisms responsible for clinical heart failure in the setting of normal left ventricular ejection fraction (HFNEF). In a human cardiovascular respiratory system (H-CRS) model we introduce three cases of left ventricular diastolic dysfunction (LVDD): (1) impaired left ventricular active relaxation (IR-type); (2) increased passive stiffness (restrictive or R-type); and (3) the combination of both (pseudo-normal or PN-type), to produce HFNEF. The effects of increasing systolic contractility are also considered. Model results showing ensuing heart failure and mechanisms involved are reported.

Methods

We employ our previously described H-CRS model with modified pulmonary compliances to better mimic normal pulmonary blood distribution. IR-type is modeled by changing the activation function of the left ventricle (LV), and R-type by increasing diastolic stiffness of the LV wall and septum. A 5th-order Cash-Karp Runge-Kutta numerical integration method solves the model differential equations.

Results

IR-type and R-type decrease LV stroke volume, cardiac output, ejection fraction (EF), and mean systemic arterial pressure. Heart rate, pulmonary pressures, pulmonary volumes, and pulmonary and systemic arterial-venous O2 and CO2 differences increase. IR-type decreases, but R-type increases the mitral E/A ratio. PN-type produces the well-described, pseudo-normal mitral inflow pattern. All three types of LVDD reduce right ventricular (RV) and LV EF, but the latter remains normal or near normal. Simulations show reduced EF is partly restored by an accompanying increase in systolic stiffness, a compensatory mechanism that may lead clinicians to miss the presence of HF if they only consider LVEF and other indices of LV function. Simulations using the H-CRS model indicate that changes in RV function might well be diagnostic. This study also highlights the importance of septal mechanics in LVDD.

Conclusion

The model demonstrates that abnormal LV diastolic performance alone can result in decreased LV and RV systolic performance, not previously appreciated, and contribute to the clinical syndrome of HF. Furthermore, alterations of RV diastolic performance are present and may be a hallmark of LV diastolic parameter changes that can be used for better clinical recognition of LV diastolic heart disease.
Effects of furosemide on the hearing loss induced by impulse noise
Authors: Adelman Cahtia , Weinberger Jeffrey M , Kriksunov Leonid , Sohmer Haim
Published: May 2011

Background

The permanent hearing loss following exposure to intense noise can be due either to mechanical structural damage (tearing) caused directly by the noise or to metabolic (biochemical) damage resulting from the elevated levels of free radicals released during transduction of the sound overstimulation. Drugs which depress active cochlear mechanics (e.g. furosemide and salicylic acid) or anti-oxidants (which counteract the free radicals) are effective in reducing the threshold shift (TS) following broadband continuous noise. This study was designed to determine whether furosemide can reduce the TS following exposure to impulse noise, similar to its action with continuous broadband noise.

Methods

Shortly after furosemide injection, mice were exposed to simulated M16 rifle impulse noise produced by different loudspeakers and amplifiers in different exposure settings and, in other experiments, also to actual M16 rifle shots.

Results

Depending on the paradigm, the simulated noises either did not produce a TS, or the TS was reduced by furosemide. The drug was not effective in reducing TS resulting from actual impulse noise.

Conclusion

Simulated M16 rifle impulse noise may not truly replicate the rapid rise time and very high intensity of actual rifle shots so that the TS following exposure to such noise can be reduced by these drugs. On the other hand, actual M16 impulse noise probably causes direct (frank) mechanical damage, which is not reduced by these drugs.
Differential regulation of diacylglycerol kinase isoform in human failing hearts
Authors: Bilim Olga , Shishido Tetsuro , Toyama Shuji , Suzuki Satoshi , Sasaki Toshiki , Kitahara Tatsuro , Sadahiro Mitsuaki , Takeishi Yasuchika , Kubota Isao
Published: May 2011

Evidence from several studies indicates the importance of Gαq protein-coupled receptor (GPCR) signaling pathway, which includes diacylglycerol (DAG), and protein kinase C, in the development of heart failure. DAG kinase (DGK) acts as an endogenous regulator of GPCR signaling pathway by catalyzing and regulating DAG. Expressions of DGK isoforms α, ε, and ζ in rodent hearts have been detected; however, the expression and alteration of DGK isoforms in a failing human heart has not yet been examined. In this study, we detected mRNA expressions of DGK isoforms γ, η, ε, and ζ in failing human heart samples obtained from patients undergoing cardiovascular surgery with cardiopulmonary bypass. Furthermore, we investigated modulation of DGK isoform expression in these hearts. We found that expressions of DGKη and DGKζ were increased and decreased, respectively, whereas those of DGKγ and DGKε remained unchanged. This is the first report that describes the differential regulation of DGK isoforms in normal and failing human hearts.
Comparative genomic hybridization on microarray (a-CGH) in constitutional and acquired mosaicism may detect as low as 8% abnormal cells
Authors: Valli Roberto , Marletta Cristina , Pressato Barbara , Montalbano Giuseppe , Lo Curto Francesco , Pasquali Francesco , Maserati Emanuela
Published: May 2011

Background

The results of cytogenetic investigations on unbalanced chromosome anomalies, both constitutional and acquired, were largely improved by comparative genomic hybridization on microarray (a-CGH), but in mosaicism the ability of a-CGH to reliably detect imbalances is not yet well established. This problem of sensitivity is even more relevant in acquired mosaicism in neoplastic diseases, where cells carrying acquired imbalances coexist with normal cells, in particular when the proportion of abnormal cells may be low.

We constructed a synthetic mosaicism by mixing the DNA of three patients carrying altogether seven chromosome imbalances with normal sex-matched DNA. Dilutions were prepared mimicking 5%, 6%, 7%, 8%, 10% and 15% levels of mosaicism. Oligomer-based a-CGH (244 K whole-genome system) was applied on the patients' DNA and customized slides designed around the regions of imbalance were used for the synthetic mosaics.

Results and conclusions

The a-CGH on the synthetic mosaics proved to be able to detect as low as 8% abnormal cells in the tissue examined. Although in our experiment some regions of imbalances escaped to be revealed at this level, and were detected only at 10-15% level, it should be remarked that these ones were the smallest analyzed, and that the imbalances recurrent as clonal anomalies in cancer and leukaemia are similar in size to those revealed at 8% level.
Physiological synaptic signals initiate sequential spikes at soma of cortical pyramidal neurons
Authors: Ge Rongjing , Qian Hao , Wang Jin-Hui
Published: May 2011

The neurons in the brain produce sequential spikes as the digital codes whose various patterns manage well-organized cognitions and behaviors. A source for the physiologically integrated synaptic signals to initiate digital spikes remains unknown, which we studied at pyramidal neurons of cortical slices. In dual recordings from the soma vs. axon, the signals recorded in vivo induce somatic spikes with higher capacity, which is associated with lower somatic thresholds and shorter refractory periods mediated by voltage-gated sodium channels. The introduction of these parameters from the soma and axon into NEURON model simulates sequential spikes being somatic in origin. Physiological signals integrated from synaptic inputs primarily trigger the soma to encode neuronal digital spikes.
Sexual risk taking among patients on antiretroviral therapy in an urban informal settlement in Kenya: a cross‐sectional survey
Authors: Ragnarsson Anders , Ekström Anna Mia , Carter Jane , Ilako Festus , Lukhwaro Abigail , Marrone Gaetano , Thorson Anna
Published: May 2011

Background

Our intention was to analyze demographic and contextual factors associated with sexual risk taking among HIV‐infected patients on antiretroviral treatment (ART) in Africa's largest informal urban settlement, Kibera in Nairobi, Kenya.

Methods

We used a cross‐sectional survey in a resource‐poor, urban informal settlement in Nairobi; 515 consecutive adult patients on ART attending the African Medical and Research Foundation clinic in Kibera in Nairobi were included in the study. Interviewers used structured questionnaires covering socio‐demographic characteristics, time on ART, number of sexual partners during the previous six months and consistency of condom use.

Results

Twenty‐eight percent of patients reported inconsistent condom use. Female patients were significantly more likely than men to report inconsistent condom use (aOR 3.03; 95% CI 1.60‐5.72). Shorter time on ART was significantly associated with inconsistent condom use. Multiple sexual partners were more common among married men than among married women (adjusted OR 4.38; 95% CI 1.82‐10.51).

Conclusions

Inconsistent condom use was especially common among women and patients who had recently started ART, i.e., when the risk of HIV transmission is higher. Having multiple partners was quite common, especially among married men, with the potential of creating sexual networks and an increased risk of HIV transmission. ART needs to be accompanied by other preventive interventions to reduce the risk of new HIV infections among sero‐discordant couples and to increase overall community effectiveness.
Hepatitis C in HIV‐infected individuals: cure and control, right now
Authors: Thomas David L , Leoutsakas Dennis , Zabransky Tomas , Kumar M Suresh
Published: May 2011

For persons living with HIV, hepatitis C is a major public health problem that must be controlled and could be eliminated. The challenge arises because the hepatitis C virus (HCV) is prevalent among HIV‐infected persons in most parts of the world, because HIV worsens all HCV outcomes, and because HCV may add additional individual economic and psychosocial complications to HIV disease. Despite the major benefits of antiretroviral therapy on HIV outcomes, antiretroviral therapy is not sufficient to halt the complications of HCV. Nonetheless, HCV can be controlled at all stages, including prevention of infection and cure. Thus, HCV is an eradicable disease. There are significant inequalities worldwide in HCV control that could markedly constrain the impact of these measures.
A comparative immunofluorescence analysis of three clinical-stage antibodies in head and neck cancer
Authors: Schwager Kathrin , Villa Alessandra , Rösli Christoph , Neri Dario , Rösli-Khabas Maria , Moser Gerhard
Published: May 2011

Background

The antibody-based targeted delivery of bioactive molecules to tumour vasculature is an attractive avenue to concentrate therapeutic agents at cancer sites, while sparing normal organs. L19, F8 and F16 are three fully human monoclonal antibodies, specific to splice isoforms of fibronectin and tenascin-C, which bind to sites of active tissue remodeling and which are currently in Phase I and II clinical trials as radio-immunoconjugates and immunocytokines in patients with cancer and arthritis.

In this article, we report the first comparative analysis of expression patterns for the extra domains EDB and EDA of fibronectin and A1 of tenascin-C in both primary and metastatic head and neck cancer lesions.

Methods

We performed a comparative immunofluorescence analysis with the L19, F8 and F16 antibodies in 40 freshly frozen human head and neck cancer specimens.

Results

On average, F8 and F16 exhibited similar staining intensities, which were typically stronger than L19. Interestingly, some specimens exhibited striking differences in staining by the three antibodies.

Conclusions

These results suggests that an individualized treatment procedure (e.g., choice of L19, F8 or F16 based on immuno-PET or immunofluorescence procedure) may represent the most logical avenue for offering the best possible antibody to any given patient.
Metabolic syndrome and dietary components are associated with coronary artery disease risk score in free-living adults: a cross-sectional study
Authors: Takahashi Mauro Massao , de Oliveira Erick Prado , de Carvalho Ana Lygia Rochitti , de Souza Dantas Lidiane Affonso , Burini Franz Homero Paganini , Portero-McLellan Kátia Cristina , Burini Roberto Carlos
Published: May 2011

Background

Coronary artery disease (CAD) is among the main causes of death in developed countries, and diet and lifestyle can influence CAD incidence.

Objective

To evaluate the association of coronary artery disease risk score with dietary, anthropometric and biochemical components in adults clinically selected for a lifestyle modification program.

Methods

362 adults (96 men, 266 women, 53.9 ± 9.4 years) fulfilled the inclusion criteria by presenting all the required data. The Framingham score was calculated and the IV Brazilian Guideline on Dyslipidemia and Prevention of Atherosclerosis was adopted for classification of the CAD risks. Anthropometric assessments included waist circumference (WC), body fat and calculated BMI (kg/m2) and muscle-mass index (MMI kg/m2). Dietary intake was estimated through 24 h dietary recall. Fasting blood was used for biochemical analysis. Metabolic Syndrome (MS) was diagnosed using NCEP-ATPIII (2001) criteria. Logistic regression was used to determine the odds of CAD risks according to the altered components of MS, dietary, anthropometric, and biochemical components.

Results

For a sample with a BMI 28.5 ± 5.0 kg/m2 the association with lower risk (<10% CAD) were lower age (<60 years old), and plasma values of uric acid. The presence of MS within low, intermediary, and high CAD risk categories was 30.8%, 55.5%, and 69.8%, respectively. The independent risk factors associated with CAD risk score was MS and uric acid, and the protective factors were recommended intake of saturated fat and fiber and muscle mass index.

Conclusion

Recommended intake of saturated fat and dietary fiber, together with proper muscle mass, are inversely associated with CAD risk score. On the other hand, the presence of MS and high plasma uric acid are associated with CAD risk score.
Comparison of four different methods for reliability evaluation of ecotoxicity data: a case study of non-standard test data used in environmental risk assessments of pharmaceutical substances
Authors: Ågerstrand Marlene , Breitholtz Magnus , Rudén Christina
Published: May 2011

Background

Standard test data are still preferred and recommended for regulatory environmental risk assessments of pharmaceuticals even though data generated by non-standard tests could improve the scientific basis of risk assessments by providing relevant and more sensitive endpoints.

The aim of this study was to investigate if non-standard ecotoxicity data can be evaluated systematically in risk assessments of pharmaceuticals. This has been done by evaluating the usefulness of four reliability evaluation methods, and by investigating whether recently published non-standard ecotoxicity studies from the open scientific literature fulfill the criteria that these methods propose.

Results

The same test data were evaluated differently by the four methods in seven out of nine cases. The selected non-standard test data were considered reliable/acceptable in only 14 out of 36 cases.

Conclusions

The four evaluation methods differ in scope, user friendliness, and how criteria are weighted and summarized. This affected the outcome of the data evaluation.

The results suggest that there is room for improvements in how data are reported in the open scientific literature. Reliability evaluation criteria could be used as a checklist to ensure that all important aspects are reported and thereby increasing the possibility that the data could be used for regulatory risk assessment.
Randomized, Placebo-Controlled, Double-Blind, Phase II Study of Axitinib Plus Docetaxel Versus Docetaxel Plus Placebo in Patients With Metastatic Breast Cancer
Authors: Rugo Hope S. , Stopeck Alison T. , Joy Anil A. , Chan Stephen , Verma Shailendra , Lluch Anna , Liau Katherine F. , Kim Sinil , Bycott Paul , Rosbrook Brad , Bair Angel H. , Soulieres Denis
Published: May 2011

Purpose

This multicenter, randomized, double-blind, phase II study assessed safety and efficacy of axitinib plus docetaxel in metastatic breast cancer (MBC).

Patients and Methods

Women with MBC were randomly assigned 2:1 to receive docetaxel 80 mg/m2 once every 3 weeks plus axitinib 5 mg twice per day (combination arm) or placebo (placebo arm), following a lead-in phase I trial. The primary end point was time to progression (TTP).

Results

In all, 168 patients were enrolled; 112 were randomly assigned to axitinib and 56 to placebo. Median TTP was numerically longer in the combination arm than in the placebo arm (8.1 v 7.1 months), but this difference was not statistically significant (hazard ratio, 1.24; 95% CI, 0.82 to 1.87; one-sided P = .156). The difference in median TTP was greatest among patients who had received prior adjuvant chemotherapy (9.2 v 7.0 months; P = .043, prespecified subgroup analysis). Objective response rate was higher in the combination arm (41.1% v 23.6%; P = .011). The most common grades 3 to 4 treatment-related adverse events (combination/placebo) included diarrhea (10.8%/0%), fatigue (10.8%/5.4%), stomatitis (12.6%/1.8%), mucositis (9.0%/0%), asthenia (7.2%/0%), and hypertension (4.5%/0%). Three patients in the combination arm experienced serious thromboembolic events (one death). Febrile neutropenia was more frequent in the combination arm (15.3% v 7.1%); rates of other hematologic toxicities were comparable. Increased toxicity with axitinib was generally managed by dose reduction and/or growth factor support.

Conclusion

The addition of axitinib to docetaxel did not improve TTP in first-line MBC treatment. Combination therapy may be more effective in patients previously exposed to adjuvant chemotherapy.
Phase II Study of Cetuximab in Combination With Chemoradiation in Patients With Stage IIIA/B Non–Small-Cell Lung Cancer: RTOG 0324
Authors: Blumenschein George R. , Paulus Rebecca , Curran Walter J. , Robert Francisco , Fossella Frank , Werner-Wasik Maria , Herbst Roy S. , Doescher Philip O. , Choy Hak , Komaki Ritsuko
Published: May 2011

Purpose

Non–small-cell lung cancer (NSCLC) commonly expresses the epidermal growth factor receptor (EGFR), which is associated with poor clinical outcome. Cetuximab is a chimerized monoclonal antibody that targets the EGFR and, in preclinical models, it demonstrates radiosensitization properties. We report a phase II trial testing the combination of cetuximab with chemoradiotherapy (CRT) in unresectable stage III NSCLC.

Patients and Methods

Eligibility criteria included unresectable stage III NSCLC, Zubrod performance status ≤ 1, weight loss ≤ 5%, forced expiratory volume in 1 second ≥ 1.2 L, and adequate organ function. Patients received an initial dose of cetuximab (400 mg/m2) on day 1 of week 1 and then weekly doses of cetuximab (250 mg/m2) until completion of therapy (weeks 2 through 17). During week 2, patients started CRT (63 Gy in 35 fractions) with weekly carboplatin at area under the [concentration-time] curve (AUC) 2 and six doses of paclitaxel at 45 mg/m2followed by carboplatin (AUC 6) and two cycles of paclitaxel (200 mg/m2) during weeks 12 through 17. Primary end points included safety and compliance of concurrent cetuximab and CRT.

Results

In all, 93 patients were enrolled and 87 were evaluable. Median follow-up was 21.6 months. Response rate was 62% (n = 54), median survival was 22.7 months, and 24-month overall survival was 49.3%. Adverse events related to treatment included 20% grade 4 hematologic toxicities, 8% grade 3 esophagitis, and 7% grade 3 to 4 pneumonitis. There were five grade 5 events.

Conclusion

The combination of cetuximab with CRT is feasible and shows promising activity. The median and overall survival achieved with this regimen were longer than any previously reported by the Radiation Therapy Oncology Group.
Metastatic and Locally Advanced Pancreatic Endocrine Carcinomas: Analysis of Factors Associated With Disease Progression
Authors: Panzuto Francesco , Boninsegna Letizia , Fazio Nicola , Campana Davide , Pia Brizzi Maria , Capurso Gabriele , Scarpa Aldo , De Braud Filippo , Dogliotti Luigi , Tomassetti Paola , Delle Fave Gianfranco , Falconi Massimo
Published: May 2011

Purpose

Knowledge of clinical course of pancreatic endocrine carcinomas (PECs) is poor. This study aimed to determine the time to progression of advanced PECs, and to identify predictors capable of selecting subgroups with higher risk of progression.

Patients and Methods

In this multicenter retrospective analysis, patients with advanced PECs were enrolled. Staging was according to European Neuroendocrine Tumors Society guidelines. Grading was based on proliferation index using Ki67 immunohistochemistry. The primary end point was progression-free survival (PFS), which was assessed using the Kaplan-Meier method. The Cox regression proportional hazard model was used to identify predictors for tumor progression.

Results

Two hundred two patients with PECs were enrolled, including 172 with well-differentiated and 30 with poorly differentiated endocrine carcinomas. There were 34 patients with stage III and 168 with stage IV tumors. G1 tumors were present in 19.7% of patients, whereas 60.1% of patients had G2 tumors, and the remaining 20.2% had G3 tumors. Disease progression occurred in 166 patients (82.2%), at a median interval of 10 months (interquartile range, 5 to 22) from diagnosis. Median PFS was 14 months. Different PFS were observed depending on G grade (P < .001) and tumor differentiation (P < .001) and in patients who did not receive any antitumor treatment (P = .002). The major risk factor for progression was the proliferation index Ki67 (hazard ratio, 1.02 for each increasing unit; P < .001). Overall 5-year survival was 44.1%.

Conclusion

The vast majority of patients with advanced PECs undergo disease progression. The major risk factor for progression is Ki67 index, which should lead physicians dealing with PECs to plan appropriate follow-up programs and therapeutic strategies.
Impact of Body Mass Index on the Efficacy of Endocrine Therapy in Premenopausal Patients With Breast Cancer: An Analysis of the Prospective ABCSG-12 Trial
Authors: Pfeiler Georg , Königsberg Robert , Fesl Christian , Mlineritsch Brigitte , Stoeger Herbert , Singer Christian F. , Pöstlberger Sabine , Steger Guenther G. , Seifert Michael , Dubsky Peter , Taucher Susanne , Samonigg Hellmut , Bjelic-Radisic Vesna , Greil Richard , Marth Christian , Gnant Michael
Published: May 2011

Purpose

Aromatase inhibitors are effective as endocrine treatment for patients with hormone receptor–positive breast cancer. According to the hypothesis that overweight patients have higher levels of aromatase enzyme availability, we investigated the influence of body mass index (BMI) on the efficacy of adjuvant endocrine therapy in premenopausal patients in a retrospective analysis of the Austrian Breast and Colorectal Cancer Study Group (ABCSG) 12 trial.

Patients and Methods

ABCSG-12 examined the efficacy of ovarian suppression using goserelin (3.6 mg subcutaneously every 28 days) in combination with anastrozole or tamoxifen with or without zoledronic acid (4 mg intravenously every 6 months) in premenopausal women with endocrine-responsive breast cancer. BMI was calculated using the prospectively collected data on patients' height and weight at study entry. BMI categories have been differentiated according to the WHO definition.

Results

Overweight patients treated with anastrozole had a 60% increase in the risk of disease recurrence (hazard ratio [HR], 1.60; 95% CI, 1.06 to 2.41; P = .02) and more than a doubling in the risk of death (HR, 2.14; 95% CI, 1.17 to 3.92; P = .01) compared with normal weight patients treated with anastrozole. In the overweight group, patients treated with anastrozole had a nearly 50% increase in the risk of disease recurrence (HR, 1.49; 95% CI, 0.93 to 2.38; P = .08) and a three-fold increase in the risk of death (HR, 3.03; 95% CI, 1.35 to 6.82; P = .004) compared with patients treated with tamoxifen.

Conclusion

BMI significantly impacts on the efficacy of anastrozole plus goserelin in premenopausal patients with breast cancer, probably through influencing aromatase availability and/or ovarian suppression by goserelin.
Risk of Recurrent Venous Thromboembolism and Mortality in Patients With Cancer Incidentally Diagnosed With Pulmonary Embolism: A Comparison With Symptomatic Patients
Authors: den Exter Paul L. , Hooijer José , Dekkers Olaf M. , Huisman Menno V.
Published: May 2011

Purpose

The routine use of modern computed tomography scanners has led to an increased detection of incidental pulmonary embolism (PE), in particular in patients with cancer. The clinical relevance of these incidental findings is unknown.

Patients and Methods

In this retrospective cohort study, oncology patients in whom PE was objectively proven between 2004 and 2010 and anticoagulant treatment was started, were included. Fifty-one patients with incidental PE and 144 with symptomatic PE were observed for 1 year to compare the risks of recurrent venous thromboembolism (VTE), bleeding complications, and mortality. Kaplan-Meier and Cox survival analyses were performed.

Results

Incidental and symptomatic patients did not differ with respect to mean age, sex, cancer type and stage, and risk factors for VTE. As a result from evolving treatment guidelines, approximately half of the patients in both groups received long-term treatment with vitamin K antagonists in stead of currently recommended low-molecular-weight heparin. The 12-month cumulative incidence of recurrent VTE was 13.3% in the incidental group versus 16.9% in the symptomatic group (P = .77). Notably, 20% VTE events recurred after premature termination of anticoagulant therapy. The risk of major bleeding complications was also comparable in the two groups (12.5% for incidental patients and 8.6% for symptomatic patients; P = .5). The respective 12-month mortality risks were 52.9% and 53.3% (P = .7).

Conclusion

Our findings suggest that oncology patients diagnosed with and treated for incidental PE, have similar high rates of recurrent VTE, bleeding complications, and mortality, as compared with oncology patients who develop symptomatic PE.