bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel method to allow noninvasive, longitudinal imaging of the murine immune system in vivo
Authors: Gibson Vivienne B. , Benson Robert A. , Bryson Karen J. , McInnes Iain B. , Rush Catherine M. , Grassia Gianluca , Maffia Pasquale , Jenkinson Eric J. , White Andrea J. , Anderson Graham , Brewer James M. , Garside Paul
Published: January 2012

In vivo imaging has revolutionized understanding of the spatiotemporal complexity that subserves the generation of successful effector and regulatory immune responses. Until now, invasive surgery has been required for microscopic access to lymph nodes (LNs), making repeated imaging of the same animal impractical and potentially affecting lymphocyte behavior. To allow longitudinal in vivo imaging, we conceived the novel approach of transplanting LNs into the mouse ear pinna. Transplanted LNs maintain the structural and cellular organization of conventional secondary lymphoid organs. They participate in lymphocyte recirculation and exhibit the capacity to receive and respond to local antigenic challenge. The same LN could be repeatedly imaged through time without the requirement for surgical exposure, and the dynamic behavior of the cells within the transplanted LN could be characterized. Crucially, the use of blood vessels as fiducial markers also allowed precise re-registration of the same regions for longitudinal imaging. Thus, we provide the first demonstration of a method for repeated, noninvasive, in vivo imaging of lymphocyte behavior.
JAM-A protects from thrombosis by suppressing integrin αIIbβ3-dependent outside-in signaling in platelets
Authors: Naik Meghna U. , Stalker Timothy J. , Brass Lawrence F. , Naik Ulhas P.
Published: January 2012

Mounting evidence suggests that agonist-initiated signaling in platelets is closely regulated to avoid excessive responses to injury. A variety of physiologic agonists induce a cascade of signaling events termed as inside-out signaling that culminate in exposure of high-affinity binding sites on integrin αIIbβ3. Once platelet activation has occurred, integrin αIIbβ3 stabilizes thrombus formation by providing agonist-independent “outside-in” signals mediated in part by contractile signaling. Junctional adhesion molecule A (JAM-A), a member of the cortical thymocyte marker of the Xenopus (CTX) family, was initially identified as a receptor for a platelet stimulatory mAb. Here we show that JAM-A in resting platelets functions as an endogenous inhibitor of platelet function. Genetic ablation of Jam-A in mice enhances thrombotic function of platelets in vivo. The absence of Jam-A results in increase in platelet aggregation ex vivo. This gain of function is not because of enhanced inside-out signaling because granular secretion, Thromboxane A2 (TxA2) generation, as well as fibrinogen receptor activation, are normal in the absence of Jam-A. Interestingly, integrin outside-in signaling such as platelet spreading and clot retraction is augmented in Jam-A–deficient platelets. We conclude that JAM-A normally limits platelet accumulation by inhibiting integrin outside-in signaling thus preventing premature platelet activation.
Genetic diversity of human RNase 8
Authors: Chan Calvin C , Moser Jennifer M , Dyer Kimberly D , Percopo Caroline M , Rosenberg Helene F
Published: January 2012

Background

Ribonuclease 8 is a member of the RNase A family of secretory ribonucleases; orthologs of this gene have been found only in primate genomes. RNase 8 is a divergent paralog of RNase 7, which is lysine-enriched, highly conserved, has prominent antimicrobial activity, and is expressed in both normal and diseased skin; in contrast, the physiologic function of RNase 8 remains uncertain. Here, we examine the genetic diversity of human RNase 8, a subject of significant interest given the existence of functional pseudogenes (coding sequences that are otherwise intact but with mutations in elements crucial for ribonucleolytic activity) in non-human primate genomes.

Results

RNase 8 expression was detected in adult human lung, spleen and testis tissue by quantitative reverse-transcription PCR. Only two single-nucleotide polymorphisms and four unique alleles were identified within the RNase 8 coding sequence; nucleotide sequence diversity (π = 0.00122 ± 0.00009 per site) was unremarkable for a human nuclear gene. We isolated transcripts encoding RNase 8 via rapid amplification of cDNA ends (RACE) and RT-PCR which included a distal potential translational start site followed by sequence encoding an additional 30 amino acids that are conserved in the genomes of several higher primates. The distal translational start site is functional and promotes RNase 8 synthesis in transfected COS-7 cells.

Conclusions

These results suggest that RNase 8 may diverge considerably from typical RNase A family ribonucleases and may likewise exhibit unique function. This finding prompts a reconsideration of what we have previously termed functional pseudogenes, as RNase 8 may be responding to constraints that promote significant functional divergence from the canonical structure and enzymatic activity characteristic of the RNase A family.
Characterization of resistance to pine wood nematode infection in Pinus thunbergiiusing suppression subtractive hybridization
Authors: Hirao Tomonori , Fukatsu Eitaro , Watanabe Atsushi
Published: January 2012

Background

Pine wilt disease is caused by the pine wood nematode, Bursaphelenchus xylophilus, which threatens pine forests and forest ecosystems worldwide and causes serious economic losses. In the 40 years since the pathogen was identified, the physiological changes occurring as the disease progresses have been characterized using anatomical and biochemical methods, and resistant trees have been selected via breeding programs. However, no studies have assessed the molecular genetics, e.g. transcriptional changes, associated with infection-induced physiological changes in resistant or susceptible trees.

Results

We constructed seven subtractive suppression hybridization (SSH) cDNA libraries using time-course sampling of trees inoculated with pine wood nematode at 1, 3, or 7 days post-inoculation (dpi) in susceptible trees and at 1, 3, 7, or 14 dpi in resistant trees. A total of 3,299 sequences was obtained from these cDNA libraries, including from 138 to 315 non-redundant sequences in susceptible SSH libraries and from 351 to 435 in resistant SSH libraries. Using Gene Ontology hierarchy, those non-redundant sequences were classified into 15 subcategories of the biological process Gene Ontology category and 17 subcategories of the molecular function category. The transcriptional components revealed by the Gene Ontology classification clearly differed between resistant and susceptible libraries. Some transcripts were discriminative: expression of antimicrobial peptide and putative pathogenesis-related genes (e.g., PR-1b, 2, 3, 4, 5, 6) was much higher in susceptible trees than in resistant trees at every time point, whereas expression of PR-9, PR-10, and cell wall-related genes (e.g., for hydroxyproline-rich glycoprotein precursor and extensin) was higher in resistant trees than in susceptible trees at 7 and 14 dpi.

Conclusions

Following inoculation with pine wood nematode, there were marked differences between resistant and susceptible trees in transcript diversity and the timing and level of transcripts expressed in common; in particular, expression of stress response and defense genes differed. This study provided new insight into the differences in the physiological changes between resistant and susceptible trees that have been observed in anatomical and biochemical studies.
Intratumoral macrophages contribute to epithelial-mesenchymal transition in solid tumors
Authors: Bonde Anne-Katrine , Tischler Verena , Kumar Sushil , Soltermann Alex , Schwendener Reto A
Published: January 2012

Background

Several stromal cell subtypes including macrophages contribute to tumor progression by inducing epithelial-mesenchymal transition (EMT) at the invasive front, a mechanism also linked to metastasis. Tumor associated macrophages (TAM) reside mainly at the invasive front but they also infiltrate tumors and in this process they mainly assume a tumor promoting phenotype. In this study, we asked if TAMs also regulate EMT intratumorally. We found that TAMs through TGF-β signaling and activation of the β-catenin pathway can induce EMT in intratumoral cancer cells.

Methods

We depleted macrophages in F9-teratocarcinoma bearing mice using clodronate-liposomes and analyzed the tumors for correlations between gene and protein expression of EMT-associated and macrophage markers. The functional relationship between TAMs and EMT was characterized in vitro in the murine F9 and mammary gland NMuMG cells, using a conditioned medium culture approach. The clinical relevance of our findings was evaluated on a tissue microarray cohort representing 491 patients with non-small cell lung cancer (NSCLC).

Results

Gene expression analysis of F9-teratocarcinomas revealed a positive correlation between TAM-densities and mesenchymal marker expression. Moreover, immunohistochemistry showed that TAMs cluster with EMT phenotype cells in the tumors. In vitro, long term exposure of F9-and NMuMG-cells to macrophage-conditioned medium led to decreased expression of the epithelial adhesion protein E-cadherin, activation of the EMT-mediating β-catenin pathway, increased expression of mesenchymal markers and an invasive phenotype. In a candidate based screen, macrophage-derived TGF-β was identified as the main inducer of this EMT-associated phenotype. Lastly, immunohistochemical analysis of NSCLC patient samples identified a positive correlation between intratumoral macrophage densities, EMT markers, intraepithelial TGF-β levels and tumor grade.

Conclusions

Data presented here identify a novel role for macrophages in EMT-promoted tumor progression. The observation that TAMs cluster with intra-epithelial fibroblastoid cells suggests that the role of macrophages in tumor-EMT extends beyond the invasive front. As macrophage infiltration and pronounced EMT tumor phenotype correlate with increased grade in NSCLC patients, we propose that TAMs also promote tumor progression by inducing EMT locally in tumors.
Validation of the self-management ability scale (SMAS) and development and validation of a shorter scale (SMAS-S) among older patients shortly after hospitalisation
Authors: Cramm Jane M , Strating Mathilde MH , de Vreede Paul L , Steverink Nardi , Nieboer Anna P
Published: January 2012

Background

The 30-item Self-Management Ability Scale (SMAS) measures self-management abilities (SMA). Objectives of this study were to (1) validate the SMAS among older people shortly after hospitalisation and (2) shorten the SMAS while maintaining adequate validity and reliability.

Methods

Our study was conducted among older individuals (≥ 65) who had recently been discharged from a hospital. Three months after hospital admission, 296/456 patients (65% response) were interviewed in their homes. We tested the instrument by means of structural equation modelling, and examined its validity and reliability. In addition, we tested internal consistency of the SMAS and SMAS-S among a study sample of patients at risk for cardiovascular diseases.

Results

After eliminating 12 items, the confirmatory factor analyses revealed good indices of fit with the resulting 18-item SMAS (SMAS-S). To estimate construct validity of the instrument, we looked at correlations between SMAS subscale scores and overall well-being scores as measured by Social Product Function (SPF-IL) and Cantril's ladder. All SMAS subscales of the original and short version significantly correlated with SPF-IL scores (all at p ≤ 0.001) and Cantril's ladder (for the cognitive well-being subscale p ≤ 0.01; all other subscales at p ≤ 0.001). The findings indicated validity. Analyses of the SMAS and SMAS-S in the sample of patients at risk for cardiovascular diseases showed that both instruments are reliable.

Conclusions

The psychometric properties of both the SMAS and SMAS-S are good. The SMAS-S is a promising alternate instrument to evaluate self-management abilities.
Factors associated with the prevalence of periodontal disease in low-risk pregnant women
Authors: Vogt Marianna , Sallum Antonio W , Cecatti José G , Morais Sirlei S
Published: January 2012

Objective

To evaluate the prevalence of periodontal disease (PD) among Brazilian low-risk pregnant women and its association with sociodemographic factors, habits and oral hygiene.

Method

This cross-sectional study included 334 low-risk pregnant women divided in groups with or without PD. Indexes of plaque and gingival bleeding on probing, probing pocket depth, clinical attachment level and gingival recession were evaluated at one periodontal examination below 32 weeks of gestation. Independent variables were: age, race/color, schooling, marital status, parity, gestational age, smoking habit, alcohol and drugs consumption, use of medication, presence of any systemic diseases and BMI (body mass index). Statistical analyses provided prevalence ratios and their respective 95%CI and also a multivariate analysis.

Results

The prevalence of PD was 47% and significantly associated with higher gestational age (PR 1.40; 1.01 - 1.94 for 17-24 weeks and PR 1.52; 1.10 - 2.08 for 25-32 weeks), maternal age 25-29 years, obesity (PR 1.65; 1.02 - 2.68) and the presence of gingival bleeding on probing (ORadj 2.01, 95%CI 1.41 - 2.88). Poor oral hygiene was associated with PD by the mean values of plaque and bleeding on probing indexes significantly greater in PD group.

Conclusions

The prevalence of PD is high and associated with gingival bleeding on probing, more advanced gestational age and obesity. A program of oral health care should be included in prenatal care for early pregnancy, especially for low-income populations.
Development of a SYBR green I based RT-PCR assay for yellow fever virus: application in assessment of YFV infection in Aedes aegypti
Authors: Dash Paban Kumar , Boutonnier Alain , Prina Eric , Sharma Shashi , Reiter Paul
Published: January 2012

Background

Yellow Fever virus (YFV) is an important arboviral pathogen in much of sub-Saharan Africa and the tropical Americas. It is the prototype member of the genus Flavivirus and is transmitted primarily by Aedes (Stegomyia) mosquitoes. The incidence of human infections in endemic areas has risen in recent years. Prompt and dependable identification of YFV is a critical component of response to suspect cases.

Results

We developed a one-step SYBR Green I-based real-time quantitative RT-PCR (qRT-PCR) assay targeting the 5'NTR and capsid-gene junction--for rapid detection and quantification of YFV. The detection limit was 1 PFU/mL, 10-fold more sensitive than conventional RT-PCR, and there was no cross-reactivity with closely related flaviviruses or with alphaviruses. Viral load in samples was determined by standard curve plotted from cycle threshold (Ct) values and virus concentration. The efficacy of the assay in mosquitoes was assessed with spiked samples. The utility of the assay for screening of pooled mosquitoes was also confirmed. Replication of a Cameroon isolate of YFV in Ae. aegypti revealed a marked variation in susceptibility among different colonies at different days post infection (pi).

Conclusions

The SYBR Green-1 based qRT-PCR assay is a faster, simpler, more sensitive and less expensive procedure for detection and quantification of YFV than other currently used methods.
Updates on the genetic variations of Norovirus in sporadic gastroenteritis in Chungnam Korea, 2009-2010
Authors: Park KwiSung , Yeo SangGu , Jeong HyeSook , Baek KyoungAh , Kim DongUk , Shin MyoungHee , Song JaeHyoung , Lee SooJin , Choi YoungJin , Park JoonSoo , Cho SungChan , Cheon DooSung
Published: January 2012

Previously, we explored the epidemic pattern and molecular characterization of noroviruses (NoVs) isolated in Chungnam, Korea in 2008, and the present study extended these observations to 2009 and 2010. In Korea, NoVs showed the seasonal prevalence from late fall to spring, and widely detected in preschool children and peoples over 60 years of age. Epidemiological pattern of NoV was similar in 2008 and in 2010, but pattern in 2009 was affected by pandemic influenza A/H1N1 2009 virus. NoV-positive samples were subjected to sequence determination of the capsid gene region, which resolved the isolated NoVs into five GI (2, 6, 7, 9 and 10) and eleven GII genotypes (1, 2, 3, 4, 6, 7, 8, 12, 13, 16 and 17). The most prevalent genotype was GII.4 and occupied 130 out of 211 NoV isolates (61.6%). Comparison of NoV GII.4 of prevalent genotype in these periods with reference strains of the same genotype was conducted to genetic analysis by a phylogenetic tree. The NoV GII.4 strains were segregated into seven distinct genetic groups, which are supported by high bootstrap values and previously reported clusters. All Korean NoV GII.4 strains belonged to either VI cluster or VII cluster. The divergence of nucleotide sequences within VI and VII intra-clusters was > 3.9% and > 3.5%, respectively. The "Chungnam(06-117)/2010" strain which was isolated in June 2010 was a variant that did not belong to cluster VI or VII and showed 5.8-8.2%, 6.2-8.1% nucleotide divergence with cluster VI and VII, respectively.
The hopes of West African refugees during resettlement in northern Sweden: a 6-year prospective qualitative study of pathways and agency thoughts
Authors: Anjum Tanvir M , Nordqvist Cecilia , Timpka Toomas
Published: January 2012

Background

Little is known about how positive phenomena can support resettlement of refugees in a new country. The aim of this study was to examine the hopeful thinking in a group of West African quota refugees at arrival and after 6 years in Sweden and compare these thoughts to the views of resettlement support professionals.

Method

The primary study population comprised 56 adult refugees and 13 resettlement professionals. Qualitative data were collected from the refugees by questionnaires on arrival and 6 years later. Data were collected from the resettlement professionals by interview about 3 years after arrival of the refugees. Snyder's cognitive model of hope was used to inform the comparative data analyses.

Results

Hopes regarding education were in focus for the refugees shortly after arrival, but thoughts on family reunion were central later in the resettlement process. During the later stages of the resettlement process, the unresponsiveness of the support organization to the family reunion problem became as issue for the refugees. The professionals reported a complex mix of "silent agency thoughts" underlying the local resettlement process as a contributing reason for this unresponsiveness.

Conclusion

Hopes regarding education and family reunion were central in the resettlement of West African refugees in Sweden. These thoughts were not systematically followed up by the support organization; possibly the resources for refugees were not fully released. More studies are needed to further investigate the motivational factors underpinning host community support of refugees' hopes and plans.
Traumatic atlantoaxial rotatory subluxation in an adolescent: a case report
Authors: Meza Escobar Luis Enrique , Osterhoff Georg , Ossendorf Christian , Wanner Guido A , Simmen Hans-Peter , Werner Clément ML
Published: January 2012

Introduction

Atlantoaxial rotatory subluxation is rarely caused by trauma in adults. Usually, the treatment of choice is traction using Halo/Gardner-Wells fixation devices for up to six weeks.

Case presentation

We present the case of a 19-year-old Caucasian woman with traumatic atlantoaxial subluxation. Early reduction three hours after trauma and immobilization using only a soft collar were performed and yielded very good clinical results.

Conclusion

In the adult population, atlantoaxial subluxation is a rare condition but is severe if untreated. Early treatment implies a non-surgical approach and a good outcome. Conservative treatment is the recommended first step for this condition.
Assessment of scientific thinking in basic science in the Iranian second national Olympiad
Authors: Azarpira Negar , Amini Mitra , Kojuri Javad , Pasalar Parvin , Soleimani Masud , Hossein Khani Saman , Ebrahimi Marzieh , Niknejhad Hassan , Karimian Zahra , Lotfi Farhad , Shahabi Shahram , Saadat Iraj , Dehghani Mohammad Reza , Mohagheghi Mohammad Ali , Adibi Payman , Bagheri Lankarani Kamran
Published: January 2012

Background

To evaluate the scientific reasoning in basic science among undergraduate medical students, we established the National Medical Science Olympiad in Iran. In this Olympiad, the drawing of a concept map was used to evaluate a student's knowledge framework; students' ability in hypothesis generation and testing were also evaluated in four different steps. All medical students were invited to participate in this program. Finally, 133 undergraduate medical students with average grades ≥ 16/20 from 45 different medical schools in Iran were selected. The program took the form of four exams: drawing a concept map (Exam I), hypothesis generation (Exam II), choosing variables based on the hypothesis (Exam III), measuring scientific thought (Exam IV). The examinees were asked to complete all examination items in their own time without using textbooks, websites, or personal consultations. Data were presented as mean ± SE of each parameter. The correlation coefficient between students' scores in each exam with the total final score and average grade was calculated using the Spearman test.

Results

Out of a possible score of 200, the mean ± SE of each exam were as follows: 183.88 ± 5.590 for Exam I; 78.68 ± 9.168 for Exam II; 92.04 ± 2.503 for exam III; 106.13 ± 2.345 for Exam IV. The correlation of each exam score with the total final score was calculated, and there was a significant correlation between them (p < 0.001). The scatter plot of the data showed a linear correlation between the score for each exam and the total final score. This meant that students with a higher final score were able to perform better in each exam through having drawn up a meaningful concept map.

The average grade was significantly correlated with the total final score (R = 0.770), (p < 0.001). There was also a significant correlation between each exam score and the average grade (p < 0.001). The highest correlation was observed between Exam I (R = 0.7708) and the average grade. This means students with higher average grades had better grades in each exam, especially in drawing the concept map.

Conclusions

We hope that this competition will encourage medical schools to integrate theory and practice, analyze data, and read research articles. Our findings relate to a selected population, and our data may not be applicable to all medical students. Therefore, further studies are required to validate our results.
Colorectal cancer screening of high-risk populations: A national survey of physicians
Authors: White Pascale M , Sahu Malini , Poles Michael A , Francois Fritz
Published: January 2012

Background

The incidence of colorectal cancer can be decreased by appropriate use of screening modalities. Patients with a family history of colon cancer and of African-American ethnicity are known to be at higher risk of developing colorectal cancer. We aimed to determine if there is a lack of physician knowledge for colorectal cancer screening guidelines based on family history and ethnicity. Between February and April 2009 an anonymous web-based survey was administered to a random sample selected from a national list of 25,000 internists, family physicians and gastroenterologists. A stratified sampling strategy was used to include practitioners from states with high as well as low CRC incidence. All data analyses were performed following data collection in 2009.

Results

The average knowledge score was 37 ± 18% among the 512 respondents. Gastroenterologists averaged higher scores compared to internists, and family physicians, p = 0.001. Only 28% of physicians correctly identified the screening initiation point for African-Americans while only 12% of physicians correctly identified the screening initiation point and interval for a patient with a family history of CRC. The most commonly cited barriers to referring high-risk patients for CRC screening were "patient refusal" and "lack of insurance reimbursement."

Conclusions

There is a lack of knowledge amongst physicians of the screening guidelines for high-risk populations, based on family history and ethnicity. Educational programs to improve physician knowledge and to reduce perceived barriers to CRC screening are warranted to address health disparities in colorectal cancer.
Temporal course of cerebrospinal fluid dynamics and amyloid accumulation in the aging rat brain from three to thirty months
Authors: Chiu Catherine , Miller Miles C , Caralopoulos Ilias N , Worden Michael S , Brinker Thomas , Gordon Zachary N , Johanson Conrad E , Silverberg Gerald D
Published: January 2012

Background

Amyloid accumulation in the brain parenchyma is a hallmark of Alzheimer's disease (AD) and is seen in normal aging. Alterations in cerebrospinal fluid (CSF) dynamics are also associated with normal aging and AD. This study analyzed CSF volume, production and turnover rate in relation to amyloid-beta peptide (Aβ) accumulation in the aging rat brain.

Methods

Aging Fischer 344/Brown-Norway hybrid rats at 3, 12, 20, and 30 months were studied. CSF production was measured by ventriculo-cisternal perfusion with blue dextran in artificial CSF; CSF volume by MRI; and CSF turnover rate by dividing the CSF production rate by the volume of the CSF space. Aβ40 and Aβ42 concentrations in the cortex and hippocampus were measured by ELISA.

Results

There was a significant linear increase in total cranial CSF volume with age: 3-20 months (p< 0.01); 3-30 months (p< 0.001). CSF production rate increased from 3-12 months (p< 0.01) and decreased from 12-30 months (p< 0.05). CSF turnover showed an initial increase from 3 months (9.40 day-1) to 12 months (11.30 day-1) and then a decrease to 20 months (10.23 day-1) and 30 months (6.62 day-1). Aβ40 and Aβ42 concentrations in brain increased from 3-30 months (p< 0.001). Both Aβ42 and Aβ40 concentrations approached a steady state level by 30 months.

Conclusions

In young rats there is no correlation between CSF turnover and Aβ brain concentrations. After 12 months, CSF turnover decreases as brain Aβ continues to accumulate. This decrease in CSF turnover rate may be one of several clearance pathway alterations that influence age-related accumulation of brain amyloid.
The Aplnr GPCR regulates myocardial progenitor development via a novel cell-non-autonomous, Gαi/o protein-independent pathway
Authors: Paskaradevan Sivani , Scott Ian C.
Published: January 2012

Myocardial progenitor development involves the migration of cells to the anterior lateral plate mesoderm (ALPM) where they are exposed to the necessary signals for heart development to proceed. Whether the arrival of cells to this location is sufficient, or whether earlier signaling events are required, for progenitor development is poorly understood. Here we demonstrate that in the absence of Aplnr signaling, cells fail to migrate to the heart-forming region of the ALPM. Our work uncovers a previously uncharacterized cell-non-autonomous function for Aplnr signaling in cardiac development. Furthermore, we show that both the single known Aplnr ligand, Apelin, and the canonical Gαi/o proteins that signal downstream of Aplnr are dispensable for Aplnr function in the context of myocardial progenitor development. This novel Aplnr signal can be substituted for by activation of Gata5/Smarcd3 in myocardial progenitors, suggesting a novel mechanism for Aplnr signaling in the establishment of a niche required for the proper migration/development of myocardial progenitor cells.
Programmed reduction of ABC transporter activity in sea urchin germline progenitors
Authors: Campanale Joseph P. , Hamdoun Amro
Published: January 2012

ATP-binding cassette (ABC) transporters protect embryos and stem cells from mutagens and pump morphogens that control cell fate and migration. In this study, we measured dynamics of ABC transporter activity during formation of sea urchin embryonic cells necessary for the production of gametes, termed the small micromeres. Unexpectedly, we found small micromeres accumulate 2.32 times more of the ABC transporter substrates calcein-AM, CellTrace RedOrange, BoDipy-verapamil and BoDipy-vinblastine, than any other cell in the embryo, indicating a reduction in multidrug efflux activity. The reduction in small micromere ABC transporter activity is mediated by a pulse of endocytosis occurring 20-60 minutes after the appearance of the micromeres – the precursors of the small micromeres. Treating embryos with phenylarsine oxide, an inhibitor of endocytosis, prevents the reduction of transporter activity. Tetramethylrhodamine dextran and cholera toxin B uptake experiments indicate that micromeres have higher rates of bulk and raft-associated membrane endocytosis during the window of transporter downregulation. We hypothesized that this loss of efflux transport could be required for the detection of developmental signaling molecules such as germ cell chemoattractants. Consistent with this hypothesis, we found that the inhibition of ABCB and ABCC-types of efflux transporters disrupts the ordered distribution of small micromeres to the left and right coelomic pouches. These results point to tradeoffs between signaling and the protective functions of the transporters.
In the absence of BYPASS1-related gene function, the bps signal disrupts embryogenesis by an auxin-independent mechanism
Authors: Lee Dong-Keun , Van Norman Jaimie M. , Murphy Caroline , Adhikari Emma , Reed Jason W. , Sieburth Leslie E.
Published: January 2012

Development is often coordinated by biologically active mobile compounds that move between cells or organs. Arabidopsis mutants with defects in the BYPASS1 (BPS1) gene overproduce an active mobile compound that moves from the root to the shoot and inhibits growth. Here, we describe two related Arabidopsis genes, BPS2 and BPS3. Analyses of single, double and triple mutants revealed that all three genes regulate production of the same mobile compound, the bps signal, with BPS1 having the largest role. The triple mutant had a severe embryo defect, including the failure to properly establish provascular tissue, the shoot meristem and the root meristem. Aberrant expression of PINFORMED1, DR5, PLETHORA1, PLETHORA2 and WUSCHEL-LIKE HOMEOBOX5 were found in heart-stage bps triple-mutant embryos. However, auxin-induced gene expression, and localization of the PIN1 auxin efflux transporter, were intact in bps1 mutants, suggesting that the primary target of the bps signal is independent of auxin response. Thus, the bps signal identifies a novel signaling pathway that regulates patterning and growth in parallel with auxin signaling, in multiple tissues and at multiple developmental stages.
Characterization by Gas Chromatography—Mass Spectrometry of Diterpenoid Resinous Materials in Roman-Age Amphorae from Northern Greece
Authors: Dimitrakoudi Evagelia A. , Mitkidou Sofia A. , Urem-Kotsou Dushka , Kotsakis Kostas , Stephanidou-Stephanatou Julia , Stratis John A.
Published: January 2012

A combined gas chromatography–mass spectrometry approach has been used for the characterization of two lumps of resin and 17 adsorbed residues on Roman-age vessels, mainly amphorae, from northern Greece. The data show that a diterpenic resin from plants of the Pinacae family is the main component of the tarry material associated with the analyzed archaeological samples. The identification and mass spectrometric fragmentation of several characteristic diterpenoid biomarkers is discussed. The abundance of secondary products identified in the archaeological samples suggests that the oxidative degradation of abietic acid and dehydroabietic acid to aromatic products was the main pathway. Of particular interest is the presence of characteristic saturated abietane hydrocarbons in one sample, which indicate that a reductive process also occurred on a small scale. The overall similarity in the composition of the residues suggests the common use of pine tar as a waterproofing and sealing agent at different sites in northern Greece during the Roman period.
Unchanged interleukin 6 level of protein and energy restricted goats during late gestation: the role of elevated blood nitric oxide
Authors: He Zhixiong , Tan Zhiliang , Sun Zhihong , Beauchemin Karen A , Tang Shaoxun , Zhou Chuanshe , Han Xuefeng , Wang Min , Wu Duanqin
Published: January 2012

Twelve pregnant goats were assigned to three dietary treatments during late gestation, namely control (C: metabolizable energy, 5.75 MJ/kg; crude protein, 12.6% and dry matter basis), 40% protein restricted (PR) and 40% energy restricted (ER), to examine the effects of nutrient restriction on the immune status of pregnant goats. Plasma was sampled on day 90, 125 and 145 from pregnant goats to determine cytokine production (interleukin 2 (IL2), IL6) and tumor necrosis factor α (TNFα)). Peripheral blood mononuclear cells were obtained on day 145 and activated by lipopolysaccharide to determine cytokine production, and then exposed (PR and ER) to sodium nitroprusside (SNP), a nitric oxide (NO) donor, or control to NG-nitro-l-arginine methyl ester hydrochloride (l-NAME), an NO synthase inhibitor to explore the role of NO in regulating cytokine production. Plasma IL2, IL6 and TNFα were not altered during gestation, but NO was increased (P<0.05) at gestation day 145 for PR and ER.In vitro, compared with control, NO was lower for PR and ER (P<0.001), but IL6 was higher for PR (P<0.001) and ER (P=0.11). The addition of SNP decreased IL6 (P<0.001, PR;P=0.12, ER) in the malnourished group, andl-NAME increased (P<0.001) IL6 in control compared to those treatments without SNP orl-NAME. The results indicate that plasma NO acted as a regulator of cytokine function exhibiting negative feedback to maintain steady plasma IL6 concentration in PR or ER goats during late gestation.
Solution Transformation of Metal Thin Films to II-VI Semiconductor Films
Authors: Gross Adam F.
Published: January 2012

The low temperature solution based transformation of silver metal layers to II-VI materials is investigated as an alternative mechanism for forming semiconductor thin films. This metal to semiconductor conversion has been demonstrated with the solution based sulfurization and ion exchange of silver nanoparticles, but not to our knowledge on thin films. Starting with metal films is attractive because they may be scalably deposited on many substrates through evaporation or electro- and electroless plating. The metal to II-VI transformation is challenging in films because diffusion occurs directionally and because the ∼40% increase in lattice expansion may cause debonding. Silver films were deposited on glass with Ti adhesion layers and successfully transformed to well-adhered CdS and MnS films at ≤ 60 ºC. The II-VI compounds were confirmed by XRD and shown to be polycrystalline with SEM. Electrical conductivities, bandgaps, and optical absorption spectra were measured. These results demonstrate that solution based sulfurization and ion-exchange is a viable mechanism for forming II-VI semiconductor thin films with good conductivities from metal films at low temperatures.
Synthesis and characterization of CeO2 nanoparticles by low temperature hydrothemal and solvent thermal process
Authors: Teo Eric Y.H. , Lin Ming , Fu Ziyuan , Ng Seng.C. , Song Siliang , Tan Jun C.
Published: January 2012

Ceria has been aggressively explored for applications as a fuel cell electrolyte or in catalytic converter due to its high oxygen ion conductivity, or as a UV absorption material. It is proven that the properties and applications of ceria nanoparticles are related to their morphologies and sizes. This ability to control the shape and morphology of CeO2 nanoparticles allows the corresponding tuning of their chemical and physical properties. Most of the applications require the use of non-agglomerated nanoparticles, as aggregated nano-particles lead to inhomogeneous mixing, poor sinterability and compromised properties. However, nano-crystals with a primary particle size < 5 nm have a strong tendency to agglomerate. In this work, nano-crystalline particles of CeO2 have been synthesized by a low temperature hydrothermal and solvent thermal synthesis process. Using the precursors of Ce(NO3)3.6H2O:NaOH in different mixing ratio, using polyvinylpyrrolidone (PVP) as the surfactant, the CeO2 particles were synthesized via 24 h hydrothermal and solvent thermal process treatment at reaction temperature of 100 °C and 180 °C using Teflon-lined hydrothermal autoclave. We have optimized the conditions for the two synthesized methods, hydrothermal and solvent thermal, to yield highly crystallized particle with controllable shape, sizes and morphology. X-ray diffraction (XRD) and high-resolution transmission electron microscope (HR-TEM) analysis were used to characterize the crystalline and morphology of the synthesized CeO2 nanoparticles. The optimal reaction condition to prepare the CeO2 of the desired octahedron shaped fluorite structure was established. Based on the results, the hydrothermal synthesis method yields nanocrystalline CeO2 sizes of ∼6 nm, while the solvent synthesis method yields nanocrystalline CeO2 sizes of 2-3 nm at the optimal conditions. The hydrothermal synthesis method produced better particles in terms of crystallinity and morphology under HR-TEM. Temperature also plays a part in crystallinity and sizes of the CeO2 nanoparticles. The crystallinity and size of the CeO2 nanoparticles increases when using higher treatment temperature for both hydrothermal and solvent thermal methods. The growth mechanism of the shape and morphology of the CeO2 will also be discussed.
Recording IR spectra for individual electrospun fibers using an in situ AFM-synchrotron technique
Authors: Stachewicz Urszula , Hang Fei , Bailey Russell J. , Gupta Himadri S. , Frogley Mark D. , Cinque Gianfelice , Barber Asa H.
Published: January 2012

A setup is described where an individual electrospun polyamide fiber is attached to an atomic force microscope (AFM) tip and structural information collected with synchrotron micro Fourier transform infrared spectroscopy (μFT-IR). The combination of AFM and synchrotron μFT-IR therefore highlights the potential for recording structure-mechanical property relationships simultaneously in materials with sub-micron dimensions.
Nasolabial Fold Discontinuity during Speech as a Possible Extended Cleft Phenotype
Authors: Schmidt Karen L. , Neiswanger Katherine , Cohn Ellen , Desensi Rebecca , Brandon Carla , Bardi Kathleen , Marazita Mary L.
Published: January 2012

Objective

This exploratory research sought to extend the cleft phenotype by identifying movement-related soft tissue appearance changes in the midfacial region in individuals with cleft lip/palate or those with genetic susceptibility to cleft lip/palate (unaffected relatives). The cleft phenotype (clinically identified orofacial cleft or subclinical orbicularis oris defect) was hypothesized to be associated with movement related appearance changes in the midfacial region, e.g., with furrowing and dimpling during speech.

Design

Changes in the appearance of skin in the midfacial region, including a newly identified phenotypic feature, nasolabial fold (NLF) discontinuity, were described and compared across groups.

Participants

Individuals with cleft lip (n = 42), unaffected relatives of persons with a cleft (n = 57) and healthy controls (n = 41) were compared.

Results

Frequencies of NLF discontinuity differed across cleft, relative, and control groups. NLF discontinuities were observed more frequently in individuals with a cleft phenotype (overt cleft or previously identified orbicularis oris muscle defect) than in those with no underlying muscular defect (Fisher exact test, P = .014).

Conclusion

Results suggest that the appearance of facial soft tissue during movement of the midface is moderated at least in part by underlying cleft risk factors, indicating certain facial movements as candidate physical markers for extension of the cleft phenotype.
Monsoons and habitat influence trophic pathways and the importance of terrestrial‐marine linkages for estuary sharks
Authors: Wai Tak-Cheung , Yeung Jamius W. Y. , Lam Vivian Y. Y. , Leung Kenneth M. Y. , Dudgeon David , Williams Gray A.
Published: January 2012

Tropical estuaries often receive enhanced fluxes of terrestrial derived organic matter and phytoplankton during the wet season, and such monsoonal events may significantly influence the trophic dynamics of these systems. This study examined spatio‐temporal terrestrial‐marine linkages in a tropical estuary, the Pearl River Estuary (PRE), southern China, by investigating trophic pathways leading to estuary sharks. We investigated spatial (inshore vs. offshore) and seasonal (wet vs. dry season) variation in the relative importance of terrestrial‐ and marine‐derived carbon, so as to assess the contribution of detrital pathways to the pelagic spadenose shark, Scoliodon laticaudus; ontogentic changes in shark diets were also documented. Stable isotope analyses (SIA) and fatty acid (FA) profiling indicated that spadenose sharks assimilated both marine and terrestrial carbon via consumption of zooplantivorous fish and shrimps. Detrital carbon sources were more important to juvenile and pre‐mature sharks at inshore locations, especially during the wet season when river discharge increased and terrestrial detritus was more abundant. Ontogenetic dietary shifts were evident: juvenile and pre‐mature sharks had significantly higher levels of bacterial (detrital) FA than adults which contained more animal‐derived FA. Inshore sharks, with more depleted δ13C signatures, relied more on terrestrial carbon than sharks offshore. Comparison of spadenose shark FA profiles with those of the sympatric, white‐spotted bamboo shark (Chiloscyllium plagiosum)—a benthic predator that acquires detrital carbon via consumption of polychaetes and crustaceans—revealed that they made greater use of detrital carbon sources. However, spadenose sharks in the inner estuary assimilated higher proportions of terrestrial detritus (44–56%) than bamboo sharks (31–45%). The importance of terrestrial detritus for both shark species demonstrated the important contribution of terrestrial detritus to both pelagic and benthic food webs in the PRE. Terrestrial‐marine linkages are therefore of great significance, particularly during the wet season, in this estuarine system, which serves as feeding and nursery grounds for both shark species, and trophic subsidies from land are likely to be important for marine predators in other tropical estuaries.
Radiation Produces Irreversible Chronic Dysfunction in the Submandibular Glands of the Rat
Authors: De la Cal C , Fernández-Solari J , Mohn CE , Prestifilippo JP , Pugnaloni A , Medina VA , Elverdin JC
Published: January 2012

The exposure to high doses of ionizing radiation during radiotherapy results in severe morphological and functional alterations of the salivary glands, such as xerostomia. In the present study we investigated the chronic effect of a single radiation dose of 15 Gray (Gy) limited to head and neck on rat salivary gland function (salivary secretion and gland mass) and histology. Results indicate that norepinephrine (NE)-induced salivary secretion was reduced significantly at 30, 90, 180 and 365 days after the administration of a single dose of 15 Gy of ionizing radiation compared to non-irradiated animals. The maximal secretory response was reduced by 33% at 30 and 90 days post irradiation. Interestingly, a new fall in the salivary response to NE was observed at 180 days and was maintained at 365 days post irradiation, showing a 75% reduction in the maximal response. The functional fall of the salivary secretion observed at 180 days post irradiation was not only associated with a reduction of gland mass but also to an alteration of the epithelial architecture exhibiting a changed proportion of ducts and acini, loss of eosinophilic secretor granular material, and glandular vacuolization and fibrosis. On the basis of the presented results, we conclude that ionizing radiation produces irreversible and progressive alterations of submandibular gland (SMG) function and morphology that leads to a severe salivary hypo-function.
Distribution Patterns of E-Cadherin, Type VII Collagen and Fibronectin in Denture-Related Stomatitis: A Preliminary Study
Authors: Bars Pierre Le , Soueidan Assem
Published: January 2012

The distribution of epithelial E-cadherin, basement membrane type VII collagen, and underlying connective tissues fibronectin were investigated immunohistochemically and compared in normal palatal mucosa and in denture-related stomatitis (DRS) derivatives using monoclonal antibodies.Biopsies of palatal mucosa were obtained from twelve patients enrolled in this study, 8 with type II DRS and 4 with healthy mucosa.

Our findings bring to the fore, using the expression of three components (E-cadherin, collagen type VII, fibronectin), the continuities of the disorder among epithelial, basement membrane and connective tissue in the case of DRS. In type II denture-related stomatitis, we found an expression of E-cadherinin all the strata of epithelia, and the diffuse and strong expression of type VII collagen at the interface between connective tissue and epithelial cells with discontinuities in BM. The strong expression of fibronectin in underlying connective tissue with penetration in some areas of the palatal mucosa may be an early consequence of advanced DRS. Nevertheless; no single change is pathognomonic of this inflammatory process.

In normal tissues (healthy clinical aspect), E-cadherin was found to be restricted to the upper strata of the epithelia, and type VII collagen revealed thin linear staining in the basement membrane and fibronectin in underlying connective tissue combined epithelia.

In the case of denture-related stomatitis DRS, these three markers reflect the immunohistological modifications from the superficial layer of the epithelium to thelamina propria.
Propagation of Convective Complexes Observed by TRMM in the Eastern Tropical Atlantic
Authors: M. Druyan Leonard , Fulakeza Matthew
Published: January 2012

Precipitation maxima during the West African summer monsoon propagate generally westward in tandem with African easterly waves. A heretofore unreported, repeating pattern of northward drift of precipitation maxima is detected on Tropical Rainfall Measurement Mission (TRMM satellite) time-latitude distributions of daily accumulations over the eastern tropical Atlantic. Corresponding 3-hourly TRMM accumulations show that the northward drifting envelopes of precipitation during August 2006 are often comprised of individual swaths propagating towards the southwest, presumably as mesoscale squall lines. The implied northward drift on the time-latitude distribution is a component of a resultant northwestward movement. The study examines the entire available record of TRMM precipitation observations, 1998-2010, to summarize TRMM maxima propagation over the eastern tropical Atlantic. Meridional displacements of precipitation maxima are most prevalent in June-September 2006, occurring less frequently during other summers. An
investigation of geopotential and circulation fields, limited to two case studies, suggests mechanisms to explain some of the observed propagation of TRMM maxima. In one event, northward drift of the precipitation envelope is consistent with the corresponding displacement of the intertropical convergence zone trough, although the southwest propagation of individual mesoscale convection maxima does not correspond to any synoptic feature on reanalysis circulation or reanalysis downscaled by a regional model. One speculation is that southwestward propagation of precipitation maxima could be caused by regeneration of convection at outflow boundaries of mature thunderstorms.