bluuebunny/crossref_metadata_2025 huggingface dataset:
Two Systems for Conditional Gene Expression in Myxococcus xanthus Inducible by Isopropyl-β-
d
-Thiogalactopyranoside or Vanillate
Authors: Iniesta Antonio A. , García-Heras Francisco , Abellón-Ruiz Javier , Gallego-García Aránzazu , Elías-Arnanz Montserrat
Published: August 2012

Conditional expression of a gene is a powerful tool to study its function and is typically achieved by placing the gene under the control of an inducible promoter. There is, however, a dearth of such inducible systems in
Myxococcus xanthus
, a well-studied prokaryotic model for multicellular development, cell differentiation, motility, and light response and a promising source of secondary metabolites. The few available systems have limitations, and exogenously based ones are unavailable. Here, we describe two new, versatile inducible systems for conditional expression of genes in
M. xanthus
. One employs isopropyl-β-
d
-thiogalactopyranoside (IPTG) as an inducer and is inspired by those successfully applied in some other bacteria. The other requires vanillate as an inducer and is based on the system developed originally for
Caulobacter crescentus
and recently adapted for mammalian cells. Both systems are robust, with essentially no expression in the absence of an inducer. Depending on the inducer and the amounts added, expression levels can be modulated such that either system can conditionally express genes, including ones that are essential and are required at high levels such as
ftsZ
. The two systems operate during vegetative growth as well as during
M. xanthus
development. Moreover, they can be used to simultaneously induce expression of distinct genes within the same cell. The conditional expression systems we describe substantially expand the genetic tool kit available for studying
M. xanthus
gene function and cellular biology.
Glucose Transport in Escherichia coli Mutant Strains with Defects in Sugar Transport Systems
Authors: Steinsiek Sonja , Bettenbrock Katja
Published: August 2012

In
Escherichia coli
, several systems are known to transport glucose into the cytoplasm. The main glucose uptake system under batch conditions is the glucose phosphoenolpyruvate:carbohydrate phosphotransferase system (glucose PTS), but the mannose PTS and the galactose and maltose transporters also can translocate glucose. Mutant strains which lack the enzyme IIBC (EIIBC) protein of the glucose PTS have been investigated previously because their lower rate of acetate formation offers advantages in industrial applications. Nevertheless, a systematic study to analyze the impact of the different glucose uptake systems has not been undertaken. Specifically, how the bacteria cope with the deletion of the major glucose uptake system and which alternative transporters react to compensate for this deficit have not been studied in detail. Therefore, a series of mutant strains were analyzed in aerobic and anaerobic batch cultures, as well as glucose-limited continuous cultivations. Deletion of EIIBC disturbs glucose transport severely in batch cultures; cyclic AMP (cAMP)-cAMP receptor protein (CRP) levels rise, and induction of the
mgl
operon occurs. Nevertheless, Mgl activity is not essential for growth of these mutants, since deletion of this transporter did not affect the growth rate; the activities of the remaining transporters seem to be sufficient. Under conditions of glucose limitation,
mgl
is upregulated 23-fold compared to levels for growth under glucose excess. Despite the strong induction of
mgl
upon glucose limitation, deletion of this transport system did not lead to further changes. Although the galactose transporters are often regarded as important for glucose uptake at micromolar concentrations, the glucose as well as mannose PTS might be sufficient for growth at this relatively low dilution rate.
Life-threatening complications following multidose methotrexate for medical management of ectopic pregnancy
Authors: Dasari Papa , Sagili Haritha
Published: August 2012

A 25-year-old primigravida was diagnosed to be suffering from unruptured ectopic pregnancy. The serum β-human chorionic gonadotropin levels were 2851 mIU/l and the ectopic gestational sac was 2.7×2.7 cm without any fetal pole. It was decided to manage her by expectant therapy. But she received medical therapy with multidose methotrexate because of misinterpretation of expectant therapy as medical therapy. She suffered from methotrexate toxicity, which manifested as high-grade fever, vomiting, melena, oral ulcerations, pneumonitis, subconjunctival haemorrhages and skin pigmentation. She developed severe third space fluid collection and shock, which was mistaken for rupture ectopic gestation. Her haematological picture showed severe neutropaenia and thrombocytopaenia which confirmed the clinical picture to be due to methotrexate toxicity. She also developed septicaemia and candidal infection secondary to immunosuppression. She was managed in intensive care unit with ventilatory support, high-dose leucovorin and injection filgastrim. She responded well to the therapy with dramatic recovery in 4 days.
Relevance of anxiety in clinical practice of Guillain-Barré syndrome: a cohort study
Authors: Sharshar Tarek , Polito Andrea , Porcher Raphaël , Merhbene Takoua , Blanc Morgane , Antona Marion , Durand Marie-Christine , Friedman Diane , Orlikowski David , Annane Djillali , Marcadet Marie-Hélène
Published: August 2012

Objectives

Illness is often associated with anxiety, but few data exist about the prognostic significance of this phenomenon. To address this issue, we assessed whether patient anxiety is associated with subsequent need for intubation in Guillain-Barré syndrome (GBS).

Design

Incident case-cohort study.

Setting

Acute secondary care in a teaching hospital (France) from 2006 to 2010.

Participants

110 adult GBS patients. Either language barrier or cognitive decline that precluded understanding was considered as exclusion criteria.

Primary outcome

Acute respiratory failure.

Interventions

At admission, anxiety and clinical factors (including known predictors of respiratory failure: delay between GBS onset and admission, inability to lift head, vital capacity (VC)) were assessed and related to subsequent need for mechanical ventilation (MV). Anxiety was assessed using a Visual Analogical Scale (VAS), the State Anxiety Inventory form Y1 (STAI-Y1) score and a novel-specific questionnaire, evaluating fears potentially triggered by GBS. Patients were asked to choose which they found most stressful from weakness, pain, breathlessness and uncertainty.

Results

23 (22%) were subsequently ventilated. Mean STAI-Y1 was 47.2 (range 22–77) and anxiety VAS 5.2 (range 0–10). STAI was above 60/80 in 22 (21%) patients and anxiety VAS above 7/10 in 28 (27%) patients. Fear of remaining paralysed, uncertainty as to how the disease would progress and fear of intubation were the most stressful. Factors significantly associated with anxiety were weakness and bulbar dysfunction. STAI-Y1 was higher and uncertainty more frequent in subsequently ventilated patients, who had shorter onset-admission delay and greater weakness but not a lower VC. Uncertainty was independently associated with subsequent MV.

Conclusions

Early management of patients with GBS should evaluate anxiety and assess its causes both to adjust psychological support and to anticipate subsequent deterioration.
Adverse drug reaction-related admissions in paediatrics, a prospective single-centre study
Authors: Posthumus Anke A G , Alingh Carien C W , Zwaan Christian C M , van Grootheest Kees K , Hanff Lidwien L M , Witjes Bregje B C M , ‘t Jong Geert W , de Hoog Matthijs
Published: August 2012

Objective

To investigate the incidence and characteristics of hospital admissions related to adverse drug events in the paediatric setting.

Design

Prospective single-centre study.

Setting

A secondary and tertiary paediatric care centre.

Participants

A total of 683 acutely admitted patients, aged 0–18 year. All acutely admitted patients, using medication before admission, were prospectively screened for possible Adverse Drug Reactions (ADR)-related admission with a trigger list. Included cases were analysed with the Naranjo score for the assessment of causality.

Main outcome measures

This research explored the incidence of ADR-related admissions and investigated the relation between ADR and the licensing status of the medicines, as well as the severity and potential to prevent the ADRs.

Results

A total of 683 patients were admitted acutely during the study period, 47 of them were exposed to cancer chemotherapy. Fifteen patients not exposed to chemotherapy (2.4%) were admitted due to an ADR. Five of these 15 ADRs (33%) were caused by unlicensed or off-label used drugs. Thirty-two patients exposed to chemotherapy (68.1%) were admitted due to an ADR; 27 of these (84%) were caused by unlicensed or off-label used drugs.

Conclusions

In conclusion, this study shows that ADR-related hospital admissions occur more frequently in the paediatric population compared with adults, and more frequently in patients exposed to cancer chemotherapy. No relation was found between the unlicensed and off-label used drugs and the incidence of ADRs.
Reporting of lifetime fractures: methodological considerations and results from the Thai Cohort Study
Authors: Berecki-Gisolf Janneke , McClure Rod , Seubsman Sam-ang , Sleigh Adrian
Published: August 2012

Objectives

To provide estimates of fracture incidence among young adults in Thailand.

Design

Cross-sectional analysis of a large national cohort.

Setting

Thailand.

Participants

A total of 60 569 study participants residing nationwide responded to the 2009 follow-up survey; 55% were women and median age was 34 years (range 19–92).

Outcome measures

Self-reported lifetime fractures, along with age at fracture. Fracture incidence rates per person-year were then compared using lifetime fracture reports, and again selecting only fractures reported for the last year. Incidence rates were compared by age and sex.

Results

18 010 lifetime fractures were reported; 11 645(65%) by men. Lifetime fracture prevalence was 30% for men and 15% for women. Lifetime incidence per 10 000 person-years was 83; analysing only fractures from the last year yielded a corresponding incidence rate of 187. For ages 21–30, fractures per 10 000 person-years were more common among men than women (283 (95% CI 244 to 326) and 150 (130 to 173), respectively); with increasing age, rates decreased among men and increased among women (for ages 51–60, 97 (58 to 151) and 286 (189 to 417), respectively).

Conclusions

Large-scale surveys provide a feasible method for establishing relative fracture incidence among informative subgroups in a population. Limiting analyses to fractures reported to have occurred recently minimises bias due to poor recall. The pattern of self-reported fracture incidence among Thais aged 20–60 was similar to that reported for Western countries: high falling rates in young men and high rising rates in older women.
‘It's on my iPhone’: attitudes to the use of mobile computing devices in medical education, a mixed-methods study
Authors: Wallace Sean , Clark Marcia , White Jonathan
Published: August 2012

Objective

The last decade has seen the introduction of new technology which has transformed many aspects of our culture, commerce, communication and education. This study examined how medical teachers and learners are using mobile computing devices such as the iPhone in medical education and practice, and how they envision them being used in the future.

Design

Semistructured interviews were conducted with medical students, residents and faculty to examine participants’ attitudes about the current and future use of mobile computing devices in medical education and practice. A thematic approach was used to summarise ideas and concepts expressed, and to develop an online survey. A mixed methods approach was used to integrate qualitative and quantitative findings.

Setting and participants

Medical students, residents and faculty at a large Canadian medical school in 2011.

Results

Interviews were conducted with 18 participants (10 students, 7 residents and 1 faculty member). Only 213 participants responded to the online survey (76 students, 65 residents and 41 faculty members). Over 85% of participants reported using a mobile-computing device. The main uses described for mobile devices related to information management, communication and time management. Advantages identified were portability, flexibility, access to multimedia and the ability to look up information quickly. Challenges identified included: superficial learning, not understanding how to find good learning resources, distraction, inappropriate use and concerns about access and privacy. Both medical students and physicians expressed the view that the use of these devices in medical education and practice will increase in the future.

Conclusions

This new technology offers the potential to enhance learning and patient care, but also has potential problems associated with its use. It is important for leadership in medical schools and healthcare organisations to set the agenda in this rapidly developing area to maximise the benefits of this powerful new technology while avoiding unintended consequences.
Equal cancer treatment regardless of education level and family support? A qualitative study of oncologists’ decision-making
Authors: Cavalli-Björkman Nina , Glimelius Bengt , Strang Peter
Published: August 2012

Objective

Treatment gradients by socioeconomic status have been observed within cancer care in several countries. The objective of this study was to explore whether patients’ educational level and social network influence oncologists’ clinical decision-making.

Design

Semi-structured interviews on factors considered when deciding on treatment for cancer patients. Interviews were transcribed and analysed using inductive qualitative content analysis.

Setting

Oncologists in Swedish university- and non-university hospitals were interviewed in their respective places of work.

Participants

Twenty Swedish clinical oncologists selected through maximum-variation sampling.

Primary and secondary outcome measures

Elements which influence oncologists’ decision-making process were explored with focus on educational level and patients’ social support systems.

Results

Oncologists consciously used less combination chemotherapy for patients living alone, fearing treatment toxicity. Highly educated patients were considered as well-read, demanding and sometimes difficult to reason with. Patients with higher education, those very keen to have treatment and persuasive relatives were considered as challenges for the oncologist. Having large groups of relatives in a room made doctors feel outnumbered. A desire to please patients and relatives was posed as the main reason for giving in to patients’ demands, even when this resulted in treatment with limited efficacy.

Conclusions

Oncologists tailor treatment for patients living alone to avoid harmful side-effects. Many find patients’ demands difficult to handle and this may result in strong socioeconomic groups being over-treated.
The role of hypoxic-inducible factor (HIF1α) and aldolaseC protein in endometrial carcinogenesis: a retrospective study of 279 patients
Authors: Mhawech-Fauceglia Paulette , Wang Dan , Samrao Damanzoopinder , Menesses Teodulo , Godoy Heidi , Ough Faith , Lele Shashikant , Liu Song , Pejovic Tanja
Published: August 2012

Objectives

Hypoxia-inducible factor (HIF1α) plays an integral role in response to hypoxia, controlling dozens of target genes including aldolaseC (ALDC), an important enzyme in the glycolytic pathway. It also induces angiogenesis, allowing survival and proliferation of cancer cells. The aims of our study were to evaluate the expressions of HIF1α and ALDC in patients with endometrial cancer (EC) and define their association with disease outcome and to determine the existence of an association between HIF1α and ALDC proteins.

Design

This is a population-based retrospective cohort study using the gynaecological-oncology database. The authors identified all women with EC with adequate follow-up. Immunohistochemistry using antibodies to ALDC and HIF1α was performed on paraffin-embedded tissue from 279 patients. To test the association between ALDC /HIF1α protein using immunohistochemistry (IHC) (positive and negative) and the clinical parameters, Fisher's exact test was performed for categorical parameters and the logistic regression model was used for continuous ones. Pearson correlation was used to check the association of IHC between ALDC and HIF1α.

Setting

Academic referral centre.

Participants

Women with EC from 2000 to 2010 obtained from the gynaecological-oncology database.

Outcome measures

The disease outcome is defined by alive with no evidence of disease versus all other outcomes.

Results

ALDC and HIF1α were overexpressed in the vast majority of EC cases (78% and 76%, respectively). There was a strong positive association between HIF1α and ALDC (p=0.0017). There was a significant association between ALDC and depth of myometrial invasion (p=0.0438), and between HIF1α and tumour grade (p=0.0231) and tumour subtype (p=0.018). However, there was no association between neither ALDC nor HIF1α and disease status.

Conclusions

ALDC and HIF1α play an important role in endometrial carcinogenesis. Their expression by the majority of EC makes inhibition of HIF1α a very attractive therapeutic option for treating patients with EC and we suggest that it will be prospectively validated in future studies.
Myocardial performance assessment in neonates by one-segment strain and strain rate analysis by tissue Doppler - a quality improvement cohort study
Authors: Nestaas Eirik , Støylen Asbjørn , Fugelseth Drude
Published: August 2012

Objectives

To investigate one-segment strain and strain rate indices as measures of myocardial performance in asphyxiated term neonates.

Design

Quality improvement cohort study.

Setting

Newborns admitted to a neonatal intensive care unit at a Norwegian University Hospital for perinatal asphyxia and non-asphyxiated newborn recruited from the maternity ward at the same hospital.

Participants

Twenty asphyxiated and 48 non-asphyxiated term neonates.

Primary outcome measure

Strain and strain rate indices and repeatability measures. One-segment longitudinal strain and strain rate by tissue Doppler were assessed on days 1, 2 and 3 of life in nine heart walls. Repeatability was compared against measurements from two-segment analyses previously performed in the same images.

Results

The 95% limits of agreement were significantly better for the one-segment than two-segment repeatability analyses, the inter-rater peak systolic strain (PSS) was (−3.1, 3.3) vs (−11.4, 18.3)%, the inter-rater peak systolic strain rate (PSSR) was (−0.38, 0.40) vs (−0.79, 1.15)/s, the intra-rater PSS was (−2.5, 2.6) vs (−8.0, 9.8)% and the intra-rater PSSR was (−0.23, 0.25) vs (−0.75, 0.80)/s (p<0.05). The myocardial performance was lower in the asphyxiated neonates (indices closer to zero) than in the non-asphyxiated neonates, PSS was −17.8 (0.6) (mean (SEM)) vs −21.2 (0.3)%, PSSR −1.43 (0.08) vs −1.61 (0.03)/s, early diastolic strain rate 1.72 (0.11) vs 2.00 (0.11)/s and strain rate during the atrial systole 1.92 (0.17) vs 2.27 (0.10)/s (p<0.05), despite no difference in fractional shortening (29.0 (0.5) vs 29.1 (1.0)%) (p>0.05).

Conclusions

One-segment strain and strain rate assessed the reduced myocardial performance in asphyxiated neonates with significantly improved reproducibility as compared with two-segment analysis and was therefore more feasible than two-segment analyses for assessment of myocardial performance after perinatal asphyxia.
Low predictive value of positive transplant perfusion fluid cultures for diagnosing postoperative infections in kidney and kidney–pancreas transplantation
Authors: Cotter Meaghan P , Smyth Elizabeth , O'Gorman Joanne , Browne Sarah , Hickey David P , Humphreys Hilary
Published: August 2012

Aims

Infection following transplantation is a cause of morbidity and mortality. Perfusion fluid (PF) used to preserve organs between recovery and transplantation represents a medium suitable for the growth of microbes. We evaluated the relevance of positive growth from PF sampled before the implantation of kidney or kidney–pancreas (KP) allografts.

Methods

Between January 2007 and January 2011, 548 kidney/KP transplants were performed in our centre. A retrospective review of patient records with culture-positive PF was performed.

Results

PF was received from 483 (88%) patients, of which 35 (7%, 95% CI 5.3% to 9.9%) were positive for bacteria (31/483, 6.4%, 95% CI 4.6% to 9.8%) and fungi (4/483, 0.8%, 95% CI 0.3% to 2.1%). Thirty-two of the 35 culture-positive PF (91.4%, 95% CI 77.6% to 97%) were considered insignificant. The remaining three patients developed sepsis postoperatively, which was considered to be possibly related to growth in PF;Escherichia coliin one andKlebsiella pneumoniaein two. Of the non-skin flora bacteria cultured from PF, six were resistant to the prophylactic antibiotic given intraoperatively, but only one developed infection postoperatively (E coli, resistant to the co-amoxiclav).

Conclusions

Significant attributable morbidity associated with PF-positive culture results was relatively rare. Culture of organisms other than Enterobacteriaceae or fungi are likely to represent contamination.
The value of examination of multiple levels of mammary needle core biopsy specimens taken for investigation of lesions other than calcification
Authors: Lee Andrew H S , Villena Salinas Nadia M , Hodi Zsolt , Rakha Emad A , Ellis Ian O
Published: August 2012

Aims

It is a standard practice to examine multiple levels of needle core biopsies taken for mammographic calcification, but there is almost no evidence on the value of levels in core biopsies taken for other reasons. This study aimed to assess the value of levels for needle core biopsies taken for investigation of lesions other than calcification. A secondary aim was to assess interobserver agreement of diagnosis.

Methods

For each of the 375 breast core biopsies with three levels the first level was reviewed and a diagnosis made. Then levels 2 and 3 were reviewed and a final diagnosis was made.

Results

The diagnosis after examining three levels was different from that in the initial level in 4 of 272 (1.5%, 95% CI 0.04% to 3%) core biopsies taken for reasons other than calcification and in 13 of 103 (13%, 95% CI 6% to 19%) biopsies taken for investigation of calcification. Interobserver agreement of the original diagnosis at the time of reporting and the final diagnosis at the review for this study was 96% (κ 0.947).

Conclusions

This study confirms the value of levels of biopsies taken to investigate mammographic calcification, but suggests that routine levels are of limited value for breast core biopsies taken for other reasons.
Comparison of a rebound tonometer with an applanation tonometer in dogs with glaucoma
Authors: Slack J. M. , Stiles J. , Moore G. E.
Published: August 2012

Eighteen dogs which presented to the Purdue University Ophthalmology Service with a final diagnosis of primary or secondary glaucoma, and 5 dogs with normal eye examinations, were evaluated. Each dog underwent a complete ophthalmic examination. An eye was categorised as glaucomatous if an intraocular pressure (IOP) measurement ≥25 mm Hg was obtained, and clinical signs consistent with glaucoma were present. Readings with the TonoVet were always performed first without topical anaesthesia. After obtaining readings with the TonoVet, one drop of proparacaine was applied to each eye, followed by IOP measurement with the Tono‐Pen XL. As IOP increased, the difference between measurements obtained with the two tonometers was statistically significant. The TonoVet consistently gave higher IOP values compared with the Tono‐Pen XL in glaucomatous eyes with Tono‐Pen XL IOP readings ≥25 mm Hg. IOP readings were not significantly different between tonometers for normotensive eyes. Based on the results of the current study, the same device should be used for monitoring of IOP in individual patients.
International disease monitoring, April to June 2012
Authors: Roberts H. , Lopez M.
Published: August 2012

African swine fever continues to spread in western Russia

Brucellosis outbreaks in Europe

Foot‐and‐mouth disease outbreaks across the Middle East and north Africa continue to present a threat to Europe

Highly pathogenic avian influenza H3N7 in Mexico in an area of high poultry density

Continued outbreaks of HPAI H5N1 in endemic areas

Information on Schmallenberg virus in ruminants in northern Europe

These are among matters discussed in the international disease monitoring report for April to June 2012, prepared by Defra's Animal Health and Veterinary Laboratories Agency
Behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy in rats
Authors: Mladenović Dušan , Radosavljević Tatjana , Hrnčić Dragan , Rašić-Marković Aleksandra , Puškaš Nela , Maksić Nebojša , Djuric Dragan , Stanojlović Olivera
Published: August 2012

The aim of our study was to investigate the behavioral and electroencephalographic manifestations of thioacetamide-induced encephalopathy in rats. Male Wistar rats were divided among (i) control, saline-treated, and (ii) thioacetamide-treated groups (TAA300(300 mg/kg body mass); TAA600(600 mg/kg); and TAA900(900 mg/kg)). The daily dose of thioacetamide (300 mg/kg) was administered intraperitoneally once (TAA300), twice (TAA600), or 3 times (TAA900), on subsequent days. Behavioral manifestations were determined at 0, 2, 4, 6, and 24 h, while electroencephalographic changes were recorded 22–24 h after the last dose. General motor activity and exploratory behavior, as well as head shake, auditory startle reflex, placement, and equlibrium tests were diminished in the TAA600and TAA900groups compared with the control, and were absent in the TAA900group 24 h after treatment. Corneal, withdrawal, grasping, and righting reflexes were significantly diminished in the TAA900group compared with the control. Mean electroencephalographic power spectra density was significantly higher in TAA300and TAA600and lower in the TAA900group by comparison with the control. Only a score of 3 (mean dominant frequency ≤ 7.3 Hz and δ relative power ≥ 45%) was observed in the TAA900group. Thioacetamide induces encephalopathy in rats in a dose-dependent manner. A dose of 900 mg/kg TAA may be used as a suitable model of all stages of hepatic encephalopathy.
Photoperiod-driven variation in an allergic response is independent of allergen exposure
Authors: Martin Lynn B. , Coon Courtney A.C.
Published: August 2012

Allergy prevalence and severity varies seasonally in humans, presumably due to intra-annual changes in allergen exposure. However, it is possible that seasonality of allergic responses is also influenced by seasonal changes in the immune system. Here, we asked whether extended exposure to different day lengths would alter allergic responses to pentadecylcatechol (PDC), an allergenic component of poison ivy ( Toxicodendron radicans (L.) Kuntze), in Siberian hamsters ( Phodopus sungorus (Pallas, 1773)), a species exhibiting extensive seasonal variation in immune functions. We found that contact dermatitis responses were larger in short day-length (SD) housed animals than in long day-length (LD) housed animals even though sensitization and challenge dosages of allergen were identical. Furthermore, SD animals were smaller and had regressed reproductive tissues compared with LD animals, results typically observed in this species in response to photoperiod. These data suggest that endogenous changes in immune functions, perhaps via melatonin, may underlie some seasonal variation in allergic responses.
Variation in diet of Semipalmated Sandpipers (Calidris pusilla) during stopover in the upper Bay of Fundy, Canada
Authors: Quinn J.T. , Hamilton D.J.
Published: August 2012

Semipalmated Sandpipers ( Calidris pusilla (L., 1766)) use the upper Bay of Fundy, Canada, as a critical stopover site during their annual fall migration to wintering grounds in South America. While in the area, they feed extensively on mudflat invertebrates. Historically the amphipod Corophium volutator (Pallas, 1766) has been thought to make up the majority of their diet. However, we have recently observed flexibility in foraging behaviour and prey selection by sandpipers. The extent of this flexibility and the current diet composition is unknown. To address these knowledge gaps, we assessed Semipalmated Sandpiper diets using stable isotope analyses of blood plasma and available prey items. Data were collected in two arms of the Bay of Fundy during summer 2009 and 2010. Diets fluctuated between years and sites, but in all cases the diet was much more diverse than previously thought. Polychaetes and biofilm made substantial contributions, and C. volutator was still present in the diet, but at much reduced levels than previously noted. This previously unrecognized inclusion of biofilm in the diet is consistent with recent observations of other calidrid shorebirds. Based on measures of prey availability, there is little evidence of preference for C. volutator.
CHARMONIUM SPECTRA AND DECAYS IN A SEMIRELATIVISTIC MODEL
Authors: BHAGHYESH  , VIJAYA KUMAR K. B.
Published: August 2012

We investigate the spectra and decays of charmonium [Formula: see text] system in a semirelativistic potential model. The Hamiltonian of our model consists of a relativistic kinetic energy term, a vector Coulomb-like potential and a scalar confining potential. From this Hamiltonian a spinless wave equation is obtained. The wave equation is then reduced to the form of a single particle Schrödinger equation. The spin dependent potentials are introduced as a perturbation. The three-dimensional harmonic oscillator wave function is employed as a trial wave function and the [Formula: see text] mass spectra is obtained by the variational method. The model parameters and the wave function that reproduce the mass spectra of the [Formula: see text] mesons are then used to investigate some of the decay properties. The results obtained are then compared with the experimental data and with the predictions of other theoretical models. We also propose possible [Formula: see text] assignments for the recently observed charmonium or charmonium-like states.
AREA SPECTRUM OF BTZ BLACK HOLES FROM THE PERIODICITY IN EUCLIDEAN TIME
Authors: LARRAÑAGA ALEXIS
Published: August 2012

In this paper, we analyze the area spectrum of BTZ three-dimensional black holes by considering an outgoing wave and relating its period of motion with the period of the gravitational system with respect to Euclidean time. The area spectra obtained for the rotating and non-rotating black holes are equally spaced and it is important to note that in this paper, we do not need to use the small angular momentum assumption which is necessary in the quasinormal mode approach for rotating black holes. The results suggest that the periodicity of the black hole gravitational system may be the origin of area quantization.
REVISIT TO DIELECTRIC PROPERTIES OF FERRITE CERAMICS
Authors: KONG L. B. , LIU L. , ZHAI J. W. , LI Z. W. , YANG Z. H.
Published: August 2012

Dielectric properties of ferrite ceramics have been less reported than their magnetic properties. Our recent study indicated that ferrite ceramics with very low dielectric loss tangent can be developed by using appropriate sintering aids, together with the optimization of other sintering parameters such as sintering temperature and time duration. Among various candidates of sintering aids, Bi 2 O 3 is the most promising one. It is important to find that the optimized concentration of sintering aid for full densification is not sufficient to achieve lowest dielectric loss tangent. This short review was aimed to summarize the understanding in microstructural evolution, grain growth, densification and dielectric properties of ferrite ceramics as a function of sintering aid concentration and sintering parameters, which could be used as a guidance to develop ferrite ceramics with low dielectric loss tangents for various applications.
IMPEDANCE SPECTROSCOPY AND MAGNETIC PROPERTIES OF AURIVILLIUS STRUCTURES
Authors: PATRI S. K. , CHOUDHARY R. N. P. , RINALDI C.
Published: August 2012

Bi 9-x Fe 5+x Ti 3 O 27 (x = 0-3) compounds of bismuth layered perovskite structure have been successfully prepared by solid-state reaction method. X-ray diffraction (XRD) studies revealed the orthorhombic crystal structure of all the compounds. Impedance spectroscopy has been studied to characterize the electrical properties of polycrystalline Bi 9-x Fe 5+x Ti 3 O 27 (x = 0-3) compounds. The shape of complex impedance curves inferred the contribution of bulk and grain boundary effects on the electrical properties of the compounds. Temperature dependent magnetization measurements were made from 2 K to 300 K. Narrow hysteresis loops observed at room temperature indicate antiferromagnetic behavior of the compounds.
Acetyl salicylic acid induces damage to intestinal epithelial cells by oxidation-related modifications of ZO-1
Authors: Fukui Akifumi , Naito Yuji , Handa Osamu , Kugai Munehiro , Tsuji Toshifumi , Yoriki Hiroyuki , Qin Ying , Adachi Satoko , Higashimura Yasuki , Mizushima Katsura , Kamada Kazuhiro , Katada Kazuhiro , Uchiyama Kazuhiko , Ishikawa Takeshi , Takagi Tomohisa , Yagi Nobuaki , Kokura Satoshi , Yoshikawa Toshikazu
Published: August 2012

Acetyl salicylic acid (ASA) is one of the most frequently prescribed medications for the secondary prevention of cardiovascular and cerebrovascular events. It has recently been reported to cause small intestinal mucosal injury at a considerably higher rate than previously believed. The aim of this study is to investigate the mechanism by which this occurs using an in vitro small intestine model focusing on the role of oxidative stress and cell permeability. Differentiated Caco-2 exhibits a phenotype similar to human small intestinal epithelium. We measured whether ASA induced the increase of differentiated Caco-2 permeability, the decrease of tight junction protein expression, the production of reactive oxygen species (ROS), and the expression of ROS-modified zonula occludens-1 (ZO-1) protein. In some experiments, Mn(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP, a superoxide dismutase mimetic) was used. The nontoxic concentration of ASA decreased transepithelial electrical resistance and increased the flux of fluorescein isothiocyanate-conjugated dextran across Caco-2 in a time-dependent manner. The same concentration of ASA significantly decreased ZO-1 expression among TJ proteins as assessed by Western blot and immunocytochemistry and increased ROS production and the expression of oxidative stress-modified ZO-1 protein. However, MnTMPyP suppressed the ASA-induced increased intercellular permeability and the ASA-induced ROS-modified ZO-1 expression. Our findings indicate that ASA-induced ROS production can specifically modify the expression of ZO-1 protein and induce increased cell permeability, which may ultimately cause small intestinal mucosal injury.
Autoregulation and mechanotransduction control the arteriolar response to small changes in hematocrit
Authors: Sriram Krishna , Salazar Vázquez Beatriz Y. , Tsai Amy G. , Cabrales Pedro , Intaglietta Marcos , Tartakovsky Daniel M.
Published: August 2012

Here, we present an analytic model of arteriolar mechanics that accounts for key autoregulation mechanisms, including the myogenic response and the vasodilatory effects of nitric oxide (NO) in the vasculature. It couples the fluid mechanics of blood flow in arterioles with solid mechanics of the vessel wall and includes the effects of wall shear stress- and stretch-induced endothelial NO production. The model can be used to describe the regulation of blood flow and NO transport under small changes in hematocrit and to analyze the regulatory response of arterioles to small changes in hematocrit. Our analysis revealed that the experimentally observed paradoxical increase in cardiac output with small increases in hematocrit results from the combination of increased NO production and the effects of a strong myogenic response modulated by elevated levels of WSS. Our findings support the hypothesis that vascular resistance varies inversely with blood viscosity for small changes in hematocrit in a healthy circulation that responds to shear stress stimuli. They also suggest beneficial effects independent of changes in O2carrying capacity associated with the postsurgical transfusion of one or two units of blood.
Effects of neuronal nitric oxide synthase inhibition on microvascular and contractile function in skeletal muscle of aged rats
Authors: Hirai Daniel M. , Copp Steven W. , Holdsworth Clark T. , Ferguson Scott K. , Musch Timothy I. , Poole David C.
Published: August 2012

Advanced age is associated with derangements in skeletal muscle microvascular function during the transition from rest to contractions. We tested the hypothesis that, contrary to what was reported previously in young rats, selective neuronal nitric oxide (NO) synthase (nNOS) inhibition would result in attenuated or absent alterations in skeletal muscle microvascular oxygenation (Po2mv), which reflects the matching between muscle O2delivery and utilization, following the onset of contractions in old rats. Spinotrapezius muscle blood flow (radiolabeled microspheres), Po2mv(phosphorescence quenching), O2utilization (V̇o2; Fick calculation), and submaximal force production were measured at rest and following the onset of contractions in anesthetized old male Fischer 344 × Brown Norway rats (27 to 28 mo) pre- and postselective nNOS inhibition (2.1 μmol/kg S-methyl-l-thiocitrulline; SMTC). At rest, SMTC had no effects on muscle blood flow ( P > 0.05) but reduced V̇o2by ∼23% ( P < 0.05), which elevated basal Po2mvby ∼18% ( P < 0.05). During contractions, steady-state muscle blood flow, V̇o2, Po2mv, and force production were not altered after SMTC ( P > 0.05 for all). The overall Po2mvdynamics following onset of contractions was also unaffected by SMTC (mean response time: pre, 19.7 ± 1.5; and post, 20.0 ± 2.0 s; P > 0.05). These results indicate that the locus of nNOS-derived NO control in skeletal muscle depends on age and metabolic rate (i.e., rest vs. contractions). Alterations in nNOS-mediated regulation of contracting skeletal muscle microvascular function with aging may contribute to poor exercise capacity in this population.
Sequential expression of IGF-IB followed by active TGF-β1 induces synergistic pulmonary fibroproliferation in vivo
Authors: Andonegui Graciela , Ni Ai , Léger Caroline , Kelly Margaret M. , Wong Josée F. , Jalloul Ali , Winston Brent W.
Published: August 2012

Pulmonary fibrosis, the end stage of a variety of fibroproliferative lung diseases, is usually induced after repetitive or chronic lung injury or inflammation. The mechanisms of fibroproliferation are poorly understood. Insulin-like growth factor-I (IGF-I) is significantly elevated in patients with pulmonary fibrosis and fibroproliferative acute respiratory distress syndrome. However, we showed that IGF-I overexpression alone in wild-type mouse lungs does not cause fibroproliferation. We therefore questioned whether IGF-I, acting together with active TGF-β1, a known profibrotic cytokine, enhances pulmonary fibroproliferation caused by active TGF-β1. A unique sequential adenoviral transgene mouse model was used expressing AdEmpty/AdTGF-β1 or AdhIGF-IB/AdTGF-β1 transgenes. IGF-IB plus active TGF-β1 transgene expression synergistically increased collagen deposition in the lung parenchyma compared with active TGF-β1 expression alone. The enhanced fibrosis was accompanied by an increased recruitment of macrophages and lymphocytes into the bronchoalveolar lavage fluid (BALF) and inflammatory cells in the lungs. α-Smooth muscle actin expression, a marker of myofibroblast proliferation and differentiation, was also increased. Finally, fibroblasts exposed ex vivo to BALF isolated from AdhIGF-IB/AdTGF-β1-transduced mice showed synergistic collagen induction compared with BALF from AdEmpty/AdTGF-β1-transduced mice. This study provides the first direct evidence that IGF-I is able to synergistically enhance pulmonary fibroproliferation in cooperation with TGF-β1.
Caveolin-1 knockout mice exhibit airway hyperreactivity
Authors: Aravamudan Bharathi , VanOosten Sarah K. , Meuchel Lucas W. , Vohra Pawan , Thompson Michael , Sieck Gary C. , Prakash Y. S. , Pabelick Christina M.
Published: August 2012

Caveolae are flask-shaped plasma membrane invaginations expressing the scaffolding caveolin proteins. Although caveolins have been found in endothelium and epithelium (where they regulate nitric oxide synthase activity), their role in smooth muscle is still under investigation. We and others have previously shown that caveolae of human airway smooth muscle (ASM), which express caveolin-1, contain Ca2+and force regulatory proteins and are involved in mediating the effects of inflammatory cytokines such as TNF-α on intracellular Ca2+concentration responses to agonist. Accordingly, we tested the hypothesis that in vivo, absence of caveolin-1 leads to reduced airway hyperresponsiveness, using a knockout (KO) (Cav1 KO) mouse and an ovalbumin-sensitized/challenged (OVA) model of allergic airway hyperresponsiveness. Surprisingly, airway responsiveness to methacholine, tested by use of a FlexiVent system, was increased in Cav1 KO control (CTL) as well as KO OVA mice, which could not be explained by a blunted immune response to OVA. In ASM of wild-type (WT) OVA mice, expression of caveolin-1, the caveolar adapter proteins cavins 1–3, and caveolae-associated Ca2+and force regulatory proteins such as Orai1 and RhoA were all increased, effects absent in Cav1 KO CTL and OVA mice. However, as with WT OVA, both CTL and OVA Cav1 KO airways showed signs of enhanced remodeling, with high expression of proliferation markers and increased collagen. Separately, epithelial cells from airways of all three groups displayed lower endothelial but higher inducible nitric oxide synthase and arginase expression. Arginase activity was also increased in these three groups, and the inhibitor nor-NOHA ( N-omega-nor-l-arginine) enhanced sensitivity of isolated tracheal rings to ACh, especially in Cav1 KO mice. On the basis of these data disproving our original hypothesis, we conclude that caveolin-1 has complex effects on ASM vs. epithelium, resulting in airway hyperreactivity in vivo mediated by altered airway remodeling and bronchodilation.
Intranasal priming of newborn mice with microbial extracts increases opsonic factors and mature CD11c+ cells in the airway
Authors: Kasahara Kazuki , Matsumura Yoko , Ui Kouji , Kasahara Kei , Komatsu Yuko , Mikasa Keiichi , Kita Eiji
Published: August 2012

Nasal exposure to the mixture of microbial extracts (MME) after ablactation enhanced airway resistance of newborn mice to Streptococcus pneumoniae ( J Physiol Lung Cell Mol Physiol 298: L67, 2010). The present study was addressed to elucidate effective factors responsible for the enhanced innate resistance in the airway of MME-exposed newborn mice. MME exposure significantly increased the amount of pulmonary surfactants (SP-A and SP-D) in the airway. Bronchoalveolar lavage fluid of the exposed mice exhibited greater levels of opsonic activity, thereby enhancing the phagocytic and intracellular killing activities of alveolar macrophages (MØ) against S. pneumoniae . The exposure itself did not increase a complement component C3 and mannan-binding lectin-A (MBL-A) in the airway, whereas intratracheal infection with S. pneumoniae increased the quantity of SP-A, SP-D, C3, and MBL-A in the exposed mice to a significant extent compared with control mice. The exposure enhanced the expression of the class A scavenger MØ receptor with collagenous structure on alveolar MØ and also increased the frequency of major histocompatibility complex II+ CD11c+ cells in the lung; the cells were able to produce IL-10 and transforming growth factor-β in vitro. These results suggest that microbial exposure early in life increases the amounts of SP-A and SP-D and the number of scavenger MØ and also promotes maturation of CD11c+ cells in the airway of newborn mice, which may be involved in airway resistance to S. pneumoniae .
Serotonin passes through myoendothelial gap junctions to promote pulmonary arterial smooth muscle cell differentiation
Authors: Gairhe Salina , Bauer Natalie N. , Gebb Sarah A. , McMurtry Ivan F.
Published: August 2012

Myoendothelial gap junctional signaling mediates pulmonary arterial endothelial cell (PAEC)-induced activation of latent TGF-β and differentiation of cocultured pulmonary arterial smooth muscle cells (PASMCs), but the nature of the signal passing from PAECs to PASMCs through the gap junctions is unknown. Because PAECs but not PASMCs synthesize serotonin, and serotonin can pass through gap junctions, we hypothesized that the monoamine is the intercellular signal. We aimed to determine whether PAEC-derived serotonin mediates PAEC-induced myoendothelial gap junction-dependent activation of TGF-β signaling and differentiation of PASMCs. Rat PAECs and PASMCs were monocultured or cocultured with (touch) or without (no-touch) direct cell-cell contact. In all cases, tryptophan hydroxylase 1 (Tph1) transcripts were expressed predominantly in PAECs. Serotonin was detected by immunostaining in both PAECs and PASMCs in PAEC/PASMC touch coculture but was not found in PASMCs in either PAEC/PASMC no-touch coculture or in PASMC/PASMC touch coculture. Furthermore, inhibition of gap junctions but not of the serotonin transporter in PAEC/PASMC touch coculture prevented serotonin transfer from PAECs to PASMCs. Inhibition of serotonin synthesis pharmacologically or by small interfering RNAs to Tph1 in PAECs inhibited the PAEC-induced activation of TGF-β signaling and differentiation of PASMCs. We concluded that serotonin synthesized by PAECs is transferred through myoendothelial gap junctions into PASMCs, where it activates TGF-β signaling and induces a more differentiated phenotype. This finding suggests a novel role of gap junction-mediated intercellular serotonin signaling in regulation of PASMC phenotype.