bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical strain induces involution-associated events in mammary epithelial cells
Authors: Quaglino Ana , Salierno Marcelo , Pellegrotti Jesica , Rubinstein Natalia , Kordon Edith C 
Published: July 2009

Abstract

Background
Shortly after weaning, a complex multi-step process that leads to massive epithelial apoptosis is triggered by tissue local factors in the mouse mammary gland. Several reports have demonstrated the relevance of mechanical stress to induce adaptive responses in different cell types. Interestingly, these signaling pathways also participate in mammary gland involution. Then, it has been suggested that cell stretching caused by milk accumulation after weaning might be the first stimulus that initiates the complete remodeling of the mammary gland. However, no previous report has demonstrated the impact of mechanical stress on mammary cell physiology. To address this issue, we have designed a new practical device that allowed us to evaluate the effects of radial stretching on mammary epithelial cells in culture.

Results
We have designed and built a new device to analyze the biological consequences of applying mechanical stress to cells cultured on flexible silicone membranes. Subsequently, a geometrical model that predicted the percentage of radial strain applied to the elastic substrate was developed. By microscopic image analysis, the adjustment of these calculations to the actual strain exerted on the attached cells was verified. The studies described herein were all performed in the HC11 non-tumorigenic mammary epithelial cell line, which was originated from a pregnant BALB/c mouse. In these cells, as previously observed in other tissue types, mechanical stress induced ERK1/2 phosphorylation and c-Fos mRNA and protein expression. In addition, we found that mammary cell stretching triggered involution associated cellular events as Leukemia Inhibitory Factor (LIF) expression induction, STAT3 activation and AKT phosphorylation inhibition.

Conclusion
Here, we show for the first time, that mechanical strain is able to induce weaning-associated events in cultured mammary epithelial cells. These results were obtained using a new practical and affordable device specifically designed for such a purpose. We believe that our results indicate the relevance of mechanical stress among the early post-lactation events that lead to mammary gland involution.
A Myc-regulated transcriptional network controls B-cell fate in response to BCR triggering
Authors: Murn Jernej , Mlinaric-Rascan Irena , Vaigot Pierre , Alibert Olivier , Frouin Vincent , Gidrol Xavier 
Published: July 2009

AbstractBackgroundThe B cell antigen receptor (BCR) is a signaling complex that mediates the differentiation of stage-specific cell fate decisions in B lymphocytes. While several studies have shown differences in signal transduction components as being key to contrasting phenotypic outcomes, little is known about the differential BCR-triggered gene transcription downstream of the signaling cascades.ResultsHere we define the transcriptional changes that underlie BCR-induced apoptosis and proliferation of immature and mature B cells, respectively. Comparative genome-wide expression profiling identified 24 genes that discriminated between the early responses of the two cell types to BCR stimulation. Using mice with a conditionalMyc-deletion, we validated the microarray data by demonstrating thatMycis critical to promoting BCR-triggered B-cell proliferation. We further investigated theMyc-dependent molecular mechanisms and found thatMycpromotes a BCR-dependent clonal expansion of mature B cells by inducing proliferation and inhibiting differentiation.ConclusionThis work provides the first comprehensive analysis of the early transcriptional events that lead to either deletion or clonal expansion of B cells upon antigen recognition, and demonstrates thatMycfunctions as the hub of a transcriptional network that control B-cell fate in the periphery.
Natural variation in gene expression in the early development of dauer larvae of Caenorhabditis elegans
Authors: Harvey Simon C , Barker Gary LA , Shorto Alison , Viney Mark E 
Published: July 2009

AbstractBackgroundThe free-living nematodeCaenorhabditis elegansmakes a developmental decision based on environmental conditions: larvae either arrest as dauer larva, or continue development into reproductive adults. There is natural variation amongC. eleganslines in the sensitivity of this decision to environmental conditions; that is, there is variation in the phenotypic plasticity of dauer larva development. We hypothesised that these differences may be transcriptionally controlled in early stage larvae. We investigated this by microarray analysis of differentC. eleganslines under different environmental conditions, specifically the presence and absence of dauer larva-inducing pheromone.ResultsThere were substantial transcriptional differences between fourC. eleganslines under the same environmental conditions. The expression of approximately 2,000 genes differed between genetically different lines, with each line showing a largely line-specific transcriptional profile. The expression of genes that are markers of larval moulting suggested that the lines may be developing at different rates. The expression of a total of 89 genes was putatively affected by dauer larva or non-dauer larva-inducing conditions. Among the upstream regions of these genes there was an over-representation of DAF-16-binding motifs.ConclusionUnder the same environmental conditions genetically different lines ofC. eleganshad substantial transcriptional differences. This variation may be due to differences in the developmental rates of the lines. Different environmental conditions had a rather smaller effect on transcription. The preponderance of DAF-16-binding motifs upstream of these genes was consistent with these genes playing a key role in the decision between development into dauer or into non-dauer larvae. There was little overlap between the genes whose expression was affected by environmental conditions and previously identified loci involved in the plasticity of dauer larva development.
Enterococci in river Ganga surface waters: Propensity of species distribution, dissemination of antimicrobial-resistance and virulence-markers among species along landscape
Authors: Lata Pushpa , Ram Siya , Agrawal Madhoolika , Shanker Rishi 
Published: July 2009

AbstractBackgroundSurface waters quality has declined in developing countries due to rapid industrialization and population growth. The microbiological quality of river Ganga, a life-sustaining surface water resource for large population of northern India, is adversely affected by several point and non-point sources of pollution. Further, untreated surface waters are consumed for drinking and various household tasks in India making the public vulnerable to water-borne diseases and outbreaks. Enterococci, the 'indicator' of water quality, correlates best with the incidence of gastrointestinal diseases as well as prevalence of other pathogenic microorganisms. Therefore, this study aims to determine the distribution of species diversity, dissemination of antimicrobial-resistance and virulence-markers in enterococci with respect to rural-urban landscape along river Ganga in northern India.ResultsEnterococci density (χ2: 1900,df: 1;p< 0.0001) increased from up-to-down gradient sites in the landscape. Species diversity exhibit significant (χ2: 100.4,df: 20;p< 0.0001) and progressive distribution ofE. faecalis,E. faecium,E. duransandE. hiraedown the gradient. Statistically discernible (p: 0.0156 – < 0.0001) background pool of resistance and virulence was observed among differentEnterococcusspp. recovered from five sites in the up-to-down gradient landscape. A significant correlation was observed in the distribution of multiple-antimicrobial-resistance (viz., erythromycin-rifampicin-gentamicin-methicillin and vancomycin-gentamicin-streptomycin;rs: 0.9747;p: 0.0083) and multiple-virulence-markers (viz.,gelE+esp+;rs: 0.9747;p: 0.0083;gelE+efaA+;rs: 0.8944;p: 0.0417) among differentEnterococcusspp.ConclusionOur observations show prevalence of multiple-antimicrobial-resistance as well as multiple-virulence traits among differentEnterococcusspp. The observed high background pool of resistance and virulence in enterococci in river waters of populous countries has the potential to disseminate more alarming antimicrobial-resistant pathogenic bacteria of same or other lineage in the environment. Therefore, the presence of elevated levels of virulent enterococci with emerging vancomycin resistance in surface waters poses serious health risk in developing countries like India.
The role of TNFgenetic variants and the interaction with cigarette smoking for gastric cancer risk: a nested case-control study
Authors: Yang Jae Jeong , Ko Kwang-Pil , Cho Lisa Y , Shin Aesun , Gwack Jin , Chang Soung-Hoon , Shin Hai-Rim , Yoo Keun-Young , Kang Daehee , Park Sue K 
Published: July 2009

AbstractBackgroundThe aim of this study was to investigate the role ofTNFgenetic variants and the combined effect betweenTNFgene and cigarette smoking in the development of gastric cancer in the Korean population.MethodsWe selected 84 incident gastric cancer cases and 336 matched controls nested within the Korean Multi-Center Cancer Cohort. Six SNPs on theTNFgene,TNF-α-238 G/A, -308 G/A, -857 C/T, -863 C/A, -1031 T/C, andTNF-β 252 A/G were genotyped. The ORs (95% CIs) were calculated using unconditional logistic regression model to detect each SNP and haplotype-pair effects for gastric cancer. The combined effects between theTNFgene and smoking on gastric cancer risk were also evaluated. Multi dimensionality reduction (MDR) analyses were performed to explore the potentialTNFgene-gene interactions.ResultsTNF-α-857 C/T containing the T allele was significantly associated with an increased risk of gastric cancer and a linear trend effect was observed in the additive model (OR = 1.6, 95% CI 1.0–2.5 for CT genotype; OR = 2.6, 95% CI 1.0–6.4 for TT genotype). All haplotype-pairs that contained TCT or CCC ofTNF-α-1031 T/C,TNF-α-863 C/A, andTNF-α-857 C/T were associated with a significantly higher risk for gastric cancer only among smokers. In the MDR analysis, regardless of smoking status,TNF-α-857 C/T was included in the first list of SNPs with a significant main effect.ConclusionTNF-α-857 C/T polymorphism may play an independent role in gastric carcinogenesis and the risk for gastric cancer byTNFgenetic effect is pronounced by cigarette smoking.
Twist expression promotes migration and invasion in hepatocellular carcinoma
Authors: Matsuo Noriyuki , Shiraha Hidenori , Fujikawa Tatsuya , Takaoka Nobuyuki , Ueda Naoki , Tanaka Shigetomi , Nishina Shinichi , Nakanishi Yutaka , Uemura Masayuki , Takaki Akinobu , Nakamura Shinichiro , Kobayashi Yoshiyuki , Nouso Kazuhiro , Yagi Takahito , Yamamoto Kazuhide 
Published: July 2009

Abstract

Background
Twist, a transcription factor of the basic helix-loop-helix class, is reported to regulate cancer metastasis. It is known to induce epithelial-mesenchymal transition (EMT). In this study, we evaluated the expression of twist and its effect on cell migration in hepatocellular carcinoma (HCC).

Methods
We examined twist expression using immunohistochemistry in 20 tissue samples of hepatocellular carcinoma, and assessed twist expression in HCC cell lines by RT-PCR and Western blot analysis. Ectopic twist expression was created by introducing a twist construct in the twist-negative HCC cell lines. Endogenous twist expression was blocked by twist siRNA in the twist-positive HCC cell lines. We studied EMT related markers, E-cadherin, Vimentin, and N-cadherin by Western blot analysis. Cell proliferation was measured by MTT assay, and cell migration was measured by in vitro wound healing assay. We used immunofluorescent vinculin staining to visualize focal adhesion.

Results
We detected strong and intermediate twist expression in 7 of 20 tumor samples, and no significant twist expression was found in the tumor-free resection margins. In addition, we detected twist expression in HLE, HLF, and SK-Hep1 cells, but not in PLC/RPF/5, HepG2, and Huh7 cells. Ectopic twist-expressing cells demonstrated enhanced cell motility, but twist expression did not affect cell proliferation. Twist expression induced epithelial-mesenchymal transition together with related morphologic changes. Focal adhesion contact was reduced significantly in ectopic twist-expressing cells. Twist-siRNA-treated HLE, HLF, and SK-Hep1 cells demonstrated a reduction in cell migration by 50, 40 and 18%, respectively.

Conclusion
Twist induces migratory effect on hepatocellular carcinoma by causing epithelial-mesenchymal transition.
Statistically significant association of the single nucleotide polymorphism (SNP) rs13181 (ERCC2) with predisposition to Squamous Cell Carcinomas of the Head and Neck (SCCHN) and Breast cancer in the north Indian population
Authors: Mitra Amit Kumar , Singh Neetu , Garg Vivek Kumar , Chaturvedi Rashmi , Sharma Mandira , Rath Srikanta Kumar 
Published: July 2009

AbstractBackgroundNon-synonymous single nucleotide polymorphisms (SNPs) within vital DNA repair genes may cause reduction of activity leaving the genome unrepaired resulting in genomic instability and cancer.Materials and methodsThe present endeavour involved study on the association of the SNP rs13181 (Lys751Gln/A18911C) in the Nucleotide Excision Repair (NER) pathway gene ERCC2 (excision repair cross-complementing rodent repair deficiency, complementation group 2) with the risks of Squamous Cell Carcinomas of the Head and Neck (SCCHN) and Breast cancer using a case-control based association study among 685 (400 controls and 285 SCCHN-affected cases) and 395 (227 normal healthy female controls and 168 breast cancer cases) ethnically-matched samples, respectively from north India using Polymerase Chain Reaction followed by Restriction Fragment Length Polymorphism (PCR-RFLP) analysis.ResultsResults showed significant association of rs13181 homozygous mutant (CC) [Odds Ratio (OR) 4.412, 95% Confidence Interval (CI) 2.413 to 8.068], heterozygous (AC) (OR 2.086, 95% CI 1.246 to 3.492) and combined mutant (AC + CC) (OR 2.672, 95% CI 1.647 to 4.334) genotypes with predisposition to Breast cancer. Statistically significant increase in SCCHN risk was also associated with the mutant genotypes of rs13181 (ERCC2), viz. homozygous mutant (CC) (OR 1.680, 95% CI 1.014 to 2.784), heterozygous (AC) (OR 1.531, 95% CI 1.092 to 2.149) and combined mutant (AC + CC) (OR 1.560, 95% CI 1.128 to 2.158) genotypes.ConclusionThe results of this case-control study indicate that the polymorphism rs13181 might be a risk factor for predisposition towards SCCHN and breast cancer among north Indian subpopulations.
A new paradigm for ammonia excretion in aquatic animals: role of Rhesus(Rh) glycoproteins
Authors: Wright Patricia A. , Wood Chris M. 
Published: July 2009

SUMMARYAmmonia excretion at the gills of fish has been studied for 80 years, but the mechanism(s) involved remain controversial. The relatively recent discovery of the ammonia-transporting function of the Rhesus (Rh) proteins, a family related to the Mep/Amt family of methyl ammonia and ammonia transporters in bacteria, yeast and plants, and the occurrence of these genes and glycosylated proteins in fish gills has opened a new paradigm. We provide background on the evolution and function of the Rh proteins, and review recent studies employing molecular physiology which demonstrate their important contribution to branchial ammonia efflux. Rhag occurs in red blood cells,whereas several isoforms of both Rhbg and Rhcg occur in many tissues. In the branchial epithelium, Rhcg appears to be localized in apical membranes and Rhbg in basolateral membranes. Their gene expression is upregulated during exposure to high environmental ammonia or internal ammonia infusion, and may be sensitive to synergistic stimulation by ammonia and cortisol. Rhcg in particular appears to be coupled to H+ excretion and Na+uptake mechanisms. We propose a new model for ammonia excretion in freshwater fish and its variable linkage to Na+ uptake and acid excretion. In this model, Rhag facilitates NH3 flux out of the erythrocyte, Rhbg moves it across the basolateral membrane of the branchial ionocyte, and an apical “Na+/NH +4 exchange complex” consisting of several membrane transporters (Rhcg, V-type H+-ATPase, Na+/H+ exchanger NHE-2 and/or NHE-3, Na+ channel) working together as a metabolon provides an acid trapping mechanism for apical excretion. Intracellular carbonic anhydrase(CA-2) and basolateral Na+/HCO –3cotransporter (NBC-1) and Na+/K+-ATPase play indirect roles. These mechanisms are normally superimposed on a substantial outward movement of NH3 by simple diffusion, which is probably dependent on acid trapping in boundary layer water by H+ ions created by the catalysed or non-catalysed hydration of expired metabolic CO2. Profitable areas for future investigation of Rh proteins in fish are highlighted: their involvement in the mechanism of ammonia excretion across the gills in seawater fish, their possible importance in ammonia excretion across the skin, their potential dual role as CO2 transporters,their responses to feeding, and their roles in early life stages prior to the full development of gills.
Skeletal muscle substrate utilization is altered by acute and acclimatory temperature in the American bullfrog (Lithobates catesbeiana)
Authors: Petersen A. M. , Gleeson T. T. 
Published: July 2009

SUMMARYWe investigated the effect of acute and acclimatory temperature on the relative contribution of glucose and lactate to metabolism in resting sartorius muscle of the American bullfrog (Lithobates catesbeiana). We examined the fate of these metabolites in vitro by supplying radiolabeled [14C]glucose, [14C]lactate and[14C]palmitate to isolated muscle bundles from frogs (1) acutely exposed to incubation conditions of 5, 15 or 25°C, (2) acclimated for 2–6 weeks to 5 or 25°C or (3) acclimated for 2–6 weeks to 5 or 25°C and the muscles incubated at 15°C. Under all three temperature conditions tested, net rate of lactate metabolism exceeded that of glucose. Acute exposure to 5°C reduced net rate of glucose metabolism by 15×and net lactate metabolism by 10× as compared with 25°C-exposed tissues. Acclimation to 5°C favored glucose storage as glycogen and increased the proportion of lactate oxidized (versus stored or converted to glucose) when compared with 25°C-acclimated tissues. Net rates of storage of lactate as glycogen (glyconeogenesis) were significantly higher in muscles from 5°C-acclimated frogs during incubation at a common temperature of 15°C. These data suggest that lactate is the predominant fuel for resting skeletal muscle over this temperature range, and particularly so under cold conditions. Ready use of lactate as a substrate, and enhancement of glyconeogenic pathways in response to cold acclimation, could play a role in the tolerance of this species to seasonal temperature changes by promoting sequestration and storage of available substrate under cold conditions.
A dynamic model of the windlass mechanism of the foot: evidence for early stance phase preloading of the plantar aponeurosis
Authors: Caravaggi Paolo , Pataky Todd , Goulermas John Y. , Savage Russel , Crompton Robin 
Published: July 2009

SUMMARY
In the present study we have estimated the temporal elongation of the plantar aponeurosis (PA) during normal walking using a subject-specific multi-segment rigid-body model of the foot. As previous studies have suggested that muscular forces at the ankle can pre-load the PA prior to heel-strike,the main purpose of the current study was to test, through modelling, whether there is any tension present in the PA during early stance phase. Reflective markers were attached to bony landmarks to track the kinematics of the calcaneus, metatarsus and toes during barefoot walking. Ultrasonography measurements were performed on three subjects to determine both the location of the origin of the PA on the plantar aspect of the calcaneus, and the radii of the metatarsal heads. Starting with the foot in a neutral, unloaded position, inverse kinematics allowed calculation of the tension in the five slips of the PA during the whole duration of the stance phase. The results show that the PA experienced tension significantly above rest during early stance phase in all subjects (P&lt;0.01), thus providing support for the PA-preloading hypothesis. The amount of preloading and the maximum elongation of the slips of the PA decreased from medial to lateral. The mean maximum tension exerted by the PA was 1.5 BW (body weight) over the three subjects.
Spiny lobsters use urine-borne olfactory signaling and physical aggressive behaviors to influence social status of conspecifics
Authors: Shabani Shkelzen , Kamio Michiya , Derby Charles D. 
Published: July 2009

SUMMARYDecapod crustaceans, like many other animals, engage in agonistic behaviors that enhance their ability to compete for resources with conspecifics. These agonistic behaviors include the release of chemical signals as well as physical aggressive and submissive behaviors. In this study, we report that Caribbean spiny lobsters, Panulirus argus, use both urine-borne chemical signaling and physical aggressive behaviors during interactions with conspecifics, and that these agonistic behaviors can influence the behavior and eventual social status of the interactants. Spiny lobsters that engaged primarily in physical aggressive behaviors became dominant, whereas spiny lobsters that received these physical aggressive behaviors responded with avoidance behaviors and became subordinates. Dominant animals frequently released urine during social interactions, more than when they were not in contact with subordinates and more than when they were not paired with another animal. Subordinates released urine significantly less often than dominants,and no more than when not paired. Preventing release of urine by catheterizing the animals resulted in an increase in the number and duration of physical interactions, and this increase was primarily driven by dominants initiating interactions through physical aggressive behaviors. Introducing urine from one of the catheterized animals into an aquarium reduced physical aggressive behavior by dominant animals to normal levels. Urine-borne signals alone were capable of inducing avoidance behaviors from solitary spiny lobsters in both laboratory and field conditions. We conclude that urine serves as a chemical signal that communicates social status to the interactants. Ablation experiments showed that that these urine signals are detected primarily by aesthetasc sensilla of the olfactory pathway.