bluuebunny/crossref_metadata_2025 huggingface dataset:
Impact of bile acids on the growth of human cholangiocarcinoma via FXR
Authors: Dai Jiaqi , Wang Hongxia , Shi Yihui , Dong Ying , Zhang Yinxin , Wang Jian
Published: October 2011

Background

The objective of the study was to investigate the effect of different types of bile acids on proliferation of cholangiocarcinoma and the potential molecular mechanisms.

Methods

PCR assay and Western blot were performed to detect the expression of farnesoid × receptor (FXR) in mRNA and protein level. Immunohistochemical analysis was carried out to monitor the expression of FXR in cholangiocarcinoma tissues from 26 patients and 10 normal controls. The effects on in vivo tumor growth were also studied in nude mouse model.

Results

Free bile acids induced an increased expression of FXR; on the contrary, the conjugated bile acids decreased the expression of FXR. The FXR effect has been illustrated with the use of the FXR agonist GW4064 and the FXR antagonist GS. More specifically, when the use of free bile acids combined with FXR agonist GW4064, the tumor cell inhibitory effect was even more pronounced. But adding FXR antagonist GS into the treatment attenuated the tumor inhibitory effect caused by free bile acids. Combined treatment of GS and CDCA could reverse the regulating effect of CDCA on the expression of FXR. Administration of CDCA and GW 4064 resulted in a significant inhibition of tumor growth. The inhibitory effect in combination group (CDCA plus GW 4064) was even more pronounced. Again, the conjugated bile acid-GDCA promoted the growth of tumor. We also found that FXR agonist GW4064 effectively blocked the stimulatory effect of GDCA on tumor growth. And the characteristic and difference of FXR expressions were in agreement with previous experimental results in mouse cholangiocarcinoma tissues. There was also significant difference in FXR expression between normal and tumor tissues from patients with cholangiocarcinoma.

Conclusions

The imbalance of ratio of free and conjugated bile acids may play an important role in tumorigenesis of cholangiocarcinoma. FXR, a member of the nuclear receptor superfamily, may mediate the effects induced by the bile acids.
Long-Term Follow-Up Analysis of HD9601 Trial Comparing ABVD Versus Stanford V Versus MOPP/EBV/CAD in Patients With Newly Diagnosed Advanced-Stage Hodgkin's Lymphoma: A Study From the Intergruppo Italiano Linfomi
Authors: Chisesi Teodoro , Bellei Monica , Luminari Stefano , Montanini Antonella , Marcheselli Luigi , Levis Alessandro , Gobbi Paolo , Vitolo Umberto , Stelitano Caterina , Pavone Vincenzo , Merli Francesco , Liberati Marina , Baldini Luca , Bordonaro Roberto , Pesce Emanuela Anna , Federico Massimo
Published: October 2011

Purpose

The Intergruppo Italiano Linfomi HD9601 trial compared doxorubicin, bleomycin, vinblastine, and dacarbazine (ABVD) versus doxorubicin, vinblastine, mechloretamine, vincristine, bleomycin, etoposide, and prednisone (Stanford V [StV]) versus the combination of mechlorethamine, vincristine, procarbazine, prednisone (MOPP) with epidoxorubicin, bleomycin, vinblastine (EBV), lomustine, doxorubicin, and vindesine (CAD) (MOPP/EBV/CAD [MEC]) for the initial treatment of advanced-stage Hodgkin's lymphoma to select which regimen would best support a reduced radiotherapy program (limited to two or fewer sites of either previous bulky or partially remitting disease). Superiority of ABVD and MEC to StV was demonstrated. We report analysis of long-term outcome and toxicity.

Patients and Methods

Patients with stage IIB, III, or IV were randomly assigned among six cycles of ABVD, three cycles of StV, and six cycles of MEC; radiotherapy was administered in 76, 71, and 50 patients in the three arms, respectively.

Results

Currently, the median follow-up is 86 months; in the prolonged observation period, eight additional failures, including two relapses, both in the StV arm, and six additional deaths in complete response were recorded. The 10-year overall survival rates were 87%, 80%, and 78% for ABVD, MEC, and StV, respectively (P = .4). The 10-year failure-free survival was 75%, 74%, and 49% in the ABVD, MEC, and StV arms, respectively (P < .001). The 10-year disease-free survival of patients treated or not with radiotherapy (RT) showed no difference for ABVD or MEC (85% v 80% and 93% v 68%), and a statistically significant difference for StV (76% v 33%; P = .004). No significant long-term toxicity was recorded.

Conclusion

The long-term analysis confirmed ABVD and MEC superiority to StV. The use of RT after StV was established as mandatory. ABVD is still to be considered as the standard treatment with a good balance between efficacy and toxicity.
Prognostic Value of a Combined Estrogen Receptor, Progesterone Receptor, Ki-67, and Human Epidermal Growth Factor Receptor 2 Immunohistochemical Score and Comparison With the Genomic Health Recurrence Score in Early Breast Cancer
Authors: Cuzick Jack , Dowsett Mitch , Pineda Silvia , Wale Christopher , Salter Janine , Quinn Emma , Zabaglo Lila , Mallon Elizabeth , Green Andrew R. , Ellis Ian O. , Howell Anthony , Buzdar Aman U. , Forbes John F.
Published: October 2011

Purpose

We recently reported that the mRNA-based, 21-gene Genomic Health recurrence score (GHI-RS) provided additional prognostic information regarding distant recurrence beyond that obtained from classical clinicopathologic factors (age, nodal status, tumor size, grade, endocrine treatment) in women with early breast cancer, confirming earlier reports. The aim of this article is to determine how much of this information is contained in standard immunohistochemical (IHC) markers.

Patients and Methods

The primary cohort comprised 1,125 estrogen receptor–positive (ER-positive) patients from the Arimidex, Tamoxifen, Alone or in Combination (ATAC) trial who did not receive adjuvant chemotherapy, had the GHI-RS computed, and had adequate tissue for the four IHC measurements: ER, progesterone receptor (PgR), human epidermal growth factor receptor 2 (HER2), and Ki-67. Distant recurrence was the primary end point, and proportional hazards models were used with sample splitting to control for overfitting. A prognostic model that used classical variables and the four IHC markers (IHC4 score) was created and assessed in a separate cohort of 786 patients.

Results

All four IHC markers provided independent prognostic information in the presence of classical variables. In sample-splitting analyses, the information in the IHC4 score was found to be similar to that in the GHI-RS, and little additional prognostic value was seen in the combined use of both scores. The prognostic value of the IHC4 score was further validated in the second separate cohort.

Conclusion

This study suggests that the amount of prognostic information contained in four widely performed IHC assays is similar to that in the GHI-RS. Additional studies are needed to determine the general applicability of the IHC4 score.
Frequency, Clinical Associations, and Longitudinal Course of Major Depressive Disorder in Adults With Cerebral Glioma
Authors: Rooney Alasdair G. , McNamara Shanne , Mackinnon Mairi , Fraser Mary , Rampling Roy , Carson Alan , Grant Robin
Published: October 2011

Purpose

There is a need for high-quality evidence regarding the frequency, independent clinical associations, and longitudinal course of depression in patients with cerebral glioma.

Patients and Methods

This was a twin-center, prospective, observational cohort study with 6-month follow-up. Consenting adults with a new diagnosis of cerebral glioma received the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition to diagnose major depressive disorder (MDD). Interviews occurred shortly after the start of radiotherapy (T1), with follow-up interviews 3 months later (T2) and 6 months later (T3). Independent associations between MDD and clinical variables were analyzed using logistic regression.

Results

One hundred fifty-five patients participated. The frequency of MDD was 13.5% ± 5.4% at T1 (n = 155); 14.8% ± 6.7% at T2 (n = 108); and 6.8% ± 5.3% at T3 (n = 88). Overall, 32 individuals were diagnosed with MDD during the study period (20.6% ± 6.4%). Inter-rater diagnostic agreement for MDD was good (κ = 0.81; 95% CI, 0.60 to 1.00). Independent predictors of MDD were functional impairment (odds ratio, 3.9; 95% CI, 1.5 to 10.8) and a previous history of depression (odds ratio, 2.7; 95% CI, 0.99 to 7.3). MDD persisted for at least 3 months in half of the patients with adequate follow-up, but many depressed patients also dropped out of the study as a result of clinical deterioration.

Conclusion

In this longitudinal study, one in five patients with glioma developed clinical depression in the 6 months after starting radiotherapy. Patients with functional impairment or previous depression were at higher risk. MDD often persisted for at least 3 months. Clinicians should seek and treat depression in adults with glioma.
End-of-Life Care and Circumstances of Death in Patients Dying As a Result of Cancer in Belgium and the Netherlands: A Retrospective Comparative Study
Authors: Meeussen Koen , Van den Block Lieve , Echteld Michael A. , Boffin Nicole , Bilsen Johan , Van Casteren Viviane , Abarshi Ebun , Donker Gé , Onwuteaka-Philipsen Bregje , Deliens Luc
Published: October 2011

Purpose

To examine and compare end-of-life care in patients with cancer dying in Belgium and the Netherlands.

Patients and Methods

A mortality follow-back study was undertaken in 2008 via representative nationwide sentinel networks of general practitioners (GPs) in Belgium and the Netherlands. By using similar standardized procedures, GPs reported on aspects of end-of-life care and the circumstances of nonsudden death of patients with cancer in their practice.

Results

Of the 422 reported patients with cancer, most resided at home during the last year of life (Belgium, 91%; the Netherlands, 95%). Death occurred at home in 34% (Belgium) and 61% (the Netherlands) and in the hospital in 29% (Belgium) and 19% (the Netherlands). In the last month of life, end-of-life issues were more often discussed in the Netherlands (88%) than in Belgium (68%). In both countries, physical problems were discussed most often (Belgium, 49%; the Netherlands, 78%) and spiritual issues least often (Belgium, 20%; the Netherlands, 32%). Certain end-of-life treatment preferences were known for 43% (Belgium) and 67% (the Netherlands) of patients. In the last week of life, treatment was most often focused on palliation (Belgium, 94%; the Netherlands, 91%). Physical distress was reported in 84% (Belgium) and 76% (the Netherlands) of patients and psychological distress in 59% and 36%. Most distressing was lack of energy (Belgium, 73%; the Netherlands, 71%) and lack of appetite (Belgium, 61%; the Netherlands, 53%). Two thirds of patients were bedridden (Belgium, 67%; the Netherlands, 69%).

Conclusion

Although place of death and communication about end-of-life issues differ substantially, a palliative treatment goal is adopted for the vast majority of patients in both countries. However, GPs reported that the majority of patients experienced symptom distress at the end of life, which suggests important challenges remain for improving end-of-life care.
Occult Metastases in Lymph Nodes Predict Survival in Resectable Non–Small-Cell Lung Cancer: Report of the ACOSOG Z0040 Trial
Authors: Rusch Valerie W. , Hawes Debra , Decker Paul A. , Martin Sue Ellen , Abati Andrea , Landreneau Rodney J. , Patterson G. Alexander , Inculet Richard I. , Jones David R. , Malthaner Richard A. , Cohen Robbin G. , Ballman Karla , Putnam Joe B. , Cote Richard J.
Published: October 2011

Purpose

The survival of patients with non–small-cell lung cancer (NSCLC), even when resectable, remains poor. Several small studies suggest that occult metastases (OMs) in pleura, bone marrow (BM), or lymph nodes (LNs) are present in early-stage NSCLC and are associated with a poor outcome. We investigated the prevalence of OMs in resectable NSCLC and their relationship with survival.

Patients and Methods

Eligible patients had previously untreated, potentially resectable NSCLC. Saline lavage of the pleural space, performed before and after pulmonary resection, was examined cytologically. Rib BM and all histologically negative LNs (N0) were examined for OM, diagnosed by cytokeratin immunohistochemistry (IHC). Survival probabilities were estimated using the Kaplan-Meier method. The log-rank test and Cox proportional hazards regression model were used to compare survival of groups of patients. P < .05 was considered significant.

Results

From July 1999 to March 2004, 1,047 eligible patients (538 men and 509 women; median age, 67.2 years) were entered onto the study, of whom 50% had adenocarcinoma and 66% had stage I NSCLC. Pleural lavage was cytologically positive in only 29 patients. OMs were identified in 66 (8.0%) of 821 BM specimens and 130 (22.4%) of 580 LN specimens. In univariate and multivariable analyses OMs in LN but not BM were associated with significantly worse disease-free survival (hazard ratio [HR], 1.50; P = .031) and overall survival (HR, 1.58; P = .009).

Conclusion

In early-stage NSCLC, LN OMs detected by IHC identify patients with a worse prognosis. Future clinical trials should test the role of IHC in identifying patients for adjuvant therapy.
Front-Line Therapy With Second-Generation Tyrosine Kinase Inhibitors in Patients With Early Chronic Phase Chronic Myeloid Leukemia: What Is the Optimal Response?
Authors: Jabbour Elias , Kantarjian Hagop M. , O'Brien Susan , Shan Jianqin , Quintás-Cardama Alfonso , Garcia-Manero Guillermo , Rios Mary Beth , Cortes Jorge E.
Published: October 2011

Purpose

The response definitions proposed by the European LeukemiaNet (ELN) are defined on the basis of imatinib front-line therapy. It is unknown whether these definitions apply to patients treated with second-generation tyrosine kinase inhibitors (TKIs).

Patients and Methods

One hundred sixty-seven patients with newly diagnosed chronic myelogenous leukemia (CML) in chronic phase were treated with second-generation TKIs in phase II trials (nilotinib, 81; dasatinib, 86). Median follow-up was 33 months. Event-free survival (EFS) was measured from the start of treatment to the date of loss of complete hematologic response, loss of complete or major cytogenetic response, discontinuation of therapy for toxicity or lack of efficacy, progression to accelerated or blastic phases, or death at any time.

Results

Overall, 155 patients (93%) achieved complete cytogenetic response (CCyR), including 146 (87%) with major molecular response (MMR; complete in 46 patients [28%]). According to the ELN definitions, the rates of suboptimal response were 0%, 2%, 1%, and 12% at 3, 6, 12, and 18 months of therapy, respectively. There was no difference in EFS and CCyR duration between patients who achieved CCyR with and without MMR across all the landmark times of 3, 6, 12, and 18 months.

Conclusion

The use of second-generation TKIs as initial therapy in CML induces high rates of CCyR at early time points. The ELN definitions of response proposed for imatinib therapy are not applicable in this setting. We propose that achievement of CCyR and partial cytogenetic response at 3 months should be considered optimal and suboptimal responses, respectively. The achievement of MMR offered no advantage over CCyR in defining long-term outcome in patients with newly diagnosed CML treated with second-generation TKIs.
Lipopolysaccharide Initiates Inflammation in Bovine Granulosa Cells via the TLR4 Pathway and Perturbs Oocyte Meiotic Progression in Vitro
Authors: Bromfield John J. , Sheldon I. Martin
Published: October 2011

Infections of the reproductive tract or mammary gland with Gram-negative bacteria perturb ovarian function, follicular growth, and fecundity in cattle. We hypothesized that lipopolysaccharide (LPS) from Gram-negative bacteria stimulates an inflammatory response by ovarian granulosa cells that is mediated by Toll-like receptor (TLR) 4. The present study tested the capacity of bovine ovarian granulosa cells to initiate an inflammatory response to pathogen-associated molecular patterns and determined subsequent effects on the in vitro maturation of oocytes. Granulosa cells elicited an inflammatory response to pathogen-associated molecular patterns (LPS, lipoteichoic acid, peptidoglycan, or Pam3CSK4) with accumulation of the cytokine IL-6, and the chemokine IL-8, in a time- and dose-dependent manner. Granulosa cells responded acutely to LPS with rapid phosphorylation of TLR signaling components, p38 and ERK, and increased expression of IL6 and IL8 mRNA, although nuclear translocation of p65 was not evident. Targeting TLR4 with small interfering RNA attenuated granulosa cell accumulation of IL-6 in response to LPS. Endocrine function of granulosa cells is regulated by FSH, but here, FSH also enhanced responsiveness to LPS, increasing IL-6 and IL-8 accumulation. Furthermore, LPS stimulated IL-6 secretion and expansion by cumulus-oocyte complexes and increased rates of meiotic arrest and germinal vesicle breakdown failure. In conclusion, bovine granulosa cells initiate an innate immune response to LPS via the TLR4 pathway, leading to inflammation and to perturbation of meiotic competence.
Cadherin Engagement Protects Human β-Cells from Apoptosis
Authors: Parnaud Géraldine , Gonelle-Gispert Carmen , Morel Philippe , Giovannoni Laurianne , Muller Yannick D. , Meier Raphael , Borot Sophie , Berney Thierry , Bosco Domenico
Published: October 2011

The aim of this study was to assess the expression of different types of cadherins in human islets and their role in human β-cell apoptosis. Expression of E-, N-, and P-cadherins was studied by immunofluorescence on pancreas sections and islet cells, and by Western blotting on protein extracts of isolated islets and islet cells. The effects of specific cadherins on cell adhesion and apoptosis were studied using chimeric proteins containing functional E-, N-, or P-cadherin ectodomains fused to Fc fragment of Ig (E-cad/Fc, N-cad/Fc, and P-cad/Fc) and immobilized on glass substrate. β-Cells were identified by immunofluorescence for insulin and apoptotic cells by terminal deoxynucleotide transferase-mediated 2′-deoxyuridine, 5′-triphosphate nick-end labeling. By immunofluorescence, we showed that E- and N-, and not P-, cadherins were expressed at the surface of islet cells. By triple staining, we showed that E-cadherin was expressed at similar extent in β- and α-cells, whereas N-cadherin was preferentially expressed in β-cells. These results were confirmed by Western blot analysis using protein extracts from fluorescence-activated cell sorting-sorted β- and non-β-cells. Adhesion tests showed that the affinity of islet cells for E-cad/Fc and N-cad/Fc and not for P-cad/Fc was increased compared with control. By terminal deoxynucleotide transferase-mediated 2′-deoxyuridine, 5′-triphosphate nick-end labeling, we showed that the percentage of apoptotic cells was lower in aggregated β-cells compared with single β-cells and that attachment to E-cad/Fc and N-cad/Fc and not to P-cad/Fc decreased apoptosis of single β-cells compared with control. Our results show that at least E- and N-cadherins are expressed at the surface of human β-cells and that these adhesion molecules are involved in the maintenance of β-cell viability.
Plasma FGF21 Is Elevated by the Intense Lipid Mobilization of Lactation
Authors: Schoenberg Katie M. , Giesy Sarah L. , Harvatine Kevin J. , Waldron Matthew R. , Cheng Christine , Kharitonenkov Alexei , Boisclair Yves R.
Published: October 2011

In many mammals, lactation success depends on substantial use of lipid reserves and requires integrated metabolic activities between white adipose tissue (WAT) and liver. Mechanisms responsible for this integration in lactation are poorly understood, but data collected in other conditions of elevated lipid use suggest a role for fibroblast growth factor-21 (FGF21). To address this possibility in the context of lactation, we studied high-yielding dairy cows during the transition from late pregnancy (LP) to early lactation (EL). Plasma FGF21 was nearly undetectable in LP, peaked on the day of parturition, and then stabilized at lower, chronically elevated concentrations during the energy deficit of EL. Plasma FGF21 was similarly increased in the absence of parturition when an energy-deficit state was induced by feed restricting late-lactating dairy cows, implicating energy insufficiency as a cause of chronically elevated FGF21 in EL. Gene expression studies showed that liver was a major source of plasma FGF21 in EL with little or no contribution by WAT, skeletal muscle, and mammary gland. Meaningful expression of the FGF21 coreceptor β-Klotho was restricted to liver and WAT in a survey of 15 tissues that included the mammary gland. Expression of β-Klotho and its subset of interacting FGF receptors was modestly affected by the transition from LP to EL in liver but not in WAT. Overall, these data suggest a model whereby liver-derived FGF21 regulates the use of lipid reserves during lactation via focal actions on liver and WAT.
Sound-induced tympanal membrane motion in bushcrickets and its relationship to sensory output
Authors: Hummel Jennifer , Kössl Manfred , Nowotny Manuela
Published: October 2011

In the auditory system of bushcrickets, sound can reach the receptors via two different paths: (i) by acting on the outside of the tympana situated on both sides of each foreleg or (ii) through the acoustic trachea that opens at a spiracle on the thorax. While the spiracle is considered to be the main point of sound entry for higher audio and ultrasonic frequencies, the role of the tympana is still unclear. The tympana border the air-filled acoustic trachea as well as the fluid-filled haemolymph channel containing the receptor organs. To understand their role during sound transduction, the sound-induced neuronal response of the hearing organ was recorded in combination with measurement of tympanal membrane motion using laser-Doppler vibrometry. For far-field stimulation, the frequency of the most sensitive hearing (∼16 kHz) matched the frequency of a pronounced maximum of tympanal membrane vibration. A second maximum of tympanum motion at lower frequencies (∼7 kHz) was correlated with an increased nerve activity at higher intensities (>70 dB sound pressure level, SPL). These correlations support the hypothesis of functional coupling between tympanum motion and nerve activity. When sound stimuli were applied locally, through either the tympanum or the spiracle, significant differences between tympanum motion and nerve activity were found. These discrepancies show that tympanum motion and neuronal response are not coupled directly and that there is no linear relationship with the applied SPL. Taken together, these data verify a functional, albeit indirect, coupling of tympanum motion and sensory cell activity for one of the pronounced vibration maxima, which appears to represent a resonance frequency of the tympanum.
Thermal adaptation in the intertidal snailEchinolittorina malaccanacontradicts current theory by revealing the crucial roles of resting metabolism
Authors: Marshall David J. , Dong Yun-wei , McQuaid Christopher D. , Williams Gray A.
Published: October 2011

Contemporary theory for thermal adaptation of ectothermic metazoans focuses on the maximization of energy gain and performance (locomotion and foraging). Little consideration is given to the selection for mechanisms that minimize resting energy loss in organisms whose energy gain is severely constrained. We tested a hypothetical framework for thermal performance of locomotor activity (a proxy for energy gain) and resting metabolism (a proxy for energy loss) in energetically compromised snails in the littoral fringe zone, comparing this with existing theory. In contrast to theory, the thermal ranges and optima for locomotor performance and metabolic performance of Echinolittorina malaccana are mismatched, and energy gain is only possible at relatively cool temperatures. To overcome thermal and temporal constraints on energy gain while experiencing high body temperatures (23–50°C), these snails depress resting metabolism between 35 and 46°C (thermally insensitive zone). The resulting bimodal relationship for metabolism against temperature contrasts with the unimodal or exponential relationships of most ectotherms. Elevation of metabolism above the breakpoint temperature for thermal insensitivity (46°C) coincides with the induction of a heat shock response, and has implications for energy expenditure and natural selection. Time-dependent mortality is initiated at this breakpoint temperature, suggesting a threshold above which the rate of energy demand exceeds the capacity for cellular energy generation (rate of ATP turnover). Mortality in a thermal range that elevates rather than limits aerobic metabolism contrasts with the hypothesis that cellular oxygen deficiency underlies temperature-related mortality. The findings of this study point to the need to incorporate aspects of resting metabolism and energy conservation into theories of thermal adaptation.
Anthropogenic noise affects song structure in red-winged blackbirds (Agelaius phoeniceus)
Authors: Hanna Dalal , Blouin-Demers Gabriel , Wilson David R. , Mennill Daniel J.
Published: October 2011

Anthropogenic noise can mask animal signals that are crucial for communicating information about food, predators and mating opportunities. In response to noise masking, signallers can potentially improve acoustic signal transmission by adjusting the timing, frequency or amplitude of their signals. These changes can be a short-term modification in response to transient noise or a long-term modification in response to chronic noise. An animal's ability to adapt to anthropogenic noise can be crucial to its success. In this study, we evaluated the effects of anthropogenic noise on the structure of red-winged blackbird song. First, we manipulated the presence of anthropogenic noise by experimentally broadcasting either silence or low-frequency white noise to subjects inhabiting quiet marshes located away from roadsides. Subjects exhibited increased signal tonality when temporarily exposed to low-frequency white noise, suggesting that red-winged blackbirds can alter their signals rapidly in response to sudden noise. Second, we compared songs produced in quiet marshes located away from roadsides with songs produced during quiet periods at roadside marshes that are normally noisy. This allowed us to test whether birds that are exposed to chronic anthropogenic noise exhibit altered song structure during temporarily quiet periods. Subjects residing in roadside marshes that are normally polluted with anthropogenic noise sang songs with increased tonality during quiet periods. Overall, our results show that anthropogenic noise influences the structure of birdsong. These effects should be considered in conservation and wildlife management.
Sound production in red-bellied piranhas (Pygocentrus nattereri, Kner): an acoustical, behavioural and morphofunctional study
Authors: Millot Sandie , Vandewalle Pierre , Parmentier Eric
Published: October 2011

Piranhas are known to be sound-producing animals. Nevertheless, the biological significance of piranha calls remains unclear because sounds have been recorded only when specimens were held by hand or trapped in a gill net. These sounds are generated by rapid contractions of sonic muscles that insert on a broad tendon surrounding ventrally the cranial sac of the swimbladder. The piranha swimbladder is thought to play an important role in sound production as an impedance-matching device and as a resonator. However, the vibratory capacities of the cranial and caudal sacs and the exact role of both sacs in sound production remain poorly understood. In this study, three sounds were each associated to a specific behaviour. The first sound (type 1) was produced during frontal display; it had numerous pulses and lasted 140!±17 ms, with a fundamental frequency of 120±4 Hz. It corresponded to the sound made by hand-held fishes. The second sound (type 2) was produced during circling and fighting behaviour; it was a single pulse lasting 36±8 ms, with a fundamental frequency of 43±10 Hz. The third sound (type 3) corresponded to chasing behaviour and comprised three to four pulses, each lasting 3±1 ms, with a fundamental frequency of 1739±18 Hz. Using a laser vibrometer to study the swimbladder displacement when stimulated at different frequencies, it was demonstrated that the first two sounds corresponded to the swimbladder mechanism. By contrast, the third sound was associated with the jaw mechanism. The vibrometer indicated that the swimbladder is a highly damping structure, simply copying the sonic muscle contraction rate. This study provides two interesting insights. First, it shows the relationships between three kinds of piranha sound and three specific behaviours. Second, using muscle stimulation at different rates, it shows which simultaneous conditions are required for production of sound in this species. Swimbladder calls were produced by a muscle contraction rate of approximately 100 Hz because this periodicity allowed the swimbladder to vibrate. At this frequency range, the contraction–relaxation cycles of the swimbladder muscles engendered wall displacements that had short amplitudes and with only a small variability between them.
First evidence for zooplankton feeding sustaining key physiological processes in a scleractinian cold-water coral
Authors: Naumann Malik S. , Orejas Covadonga , Wild Christian , Ferrier-Pagès Christine
Published: October 2011

Scleractinian cold-water corals (CWC) represent key taxa controlling deep-sea reef ecosystem functioning by providing structurally complex habitats to a high associated biodiversity, and by fuelling biogeochemical cycles via the release of organic matter. Nevertheless, our current knowledge on basic CWC properties, such as feeding ecology and key physiological processes (i.e. respiration, calcification and organic matter release), is still very limited. Here, we show evidence for the trophic significance of zooplankton, essentially sustaining levels of the investigated key physiological processes in the cosmopolitan CWC Desmophyllum dianthus (Esper 1794). Our results from laboratory studies reveal that withdrawal (for up to 3 weeks) of zooplankton food (i.e. Artemia salina) caused a significant decline in respiration (51%) and calcification (69%) rates compared with zooplankton-fed specimens. Likewise, organic matter release, in terms of total organic carbon (TOC), decreased significantly and eventually indicated TOC net uptake after prolonged zooplankton exclusion. In fed corals, zooplankton provided 1.6 times the daily metabolic C demand, while TOC release represented 7% of zooplankton-derived organic C. These findings highlight zooplankton as a nutritional source for D. dianthus, importantly sustaining respiratory metabolism, growth and organic matter release, with further implications for the role of CWC as deep-sea reef ecosystem engineers.
Patient and provider delays in breast cancer patients attending a tertiary care centre: a prospective study
Authors: Chintamani  , Tuteja Amita , Khandelwal Rohan , Megha Tandon , Bamal Rahul , Jain Sidharth , Narayan Nikhil , Srinivas S , Kumar Yashwant
Published: October 2011

Objectives

To find out factors that are responsible for the patient or provider delays in the diagnosis of breast cancer in India.

Design

This prospective study was designed to be conducted over a period of two years including a cohort of 100 patients with locally advanced breast cancer. The delays were assessed using questionnaires prepared according to the Indian scenario.

Setting

A prospective study in an Indian setting.

Participants

One hundred patients with locally advanced breast cancer receiving neoadjuvant chemotherapy were included after providing informed consent and receiving ethical committee clearance.

Main outcome measures

The most common factor responsible for delays in diagnosis was observed to be the health providers, although illiteracy and lack of adequate healthcare services also contributed significantly. Unregistered medical practitioners or quacks contributed significantly to the delays in reporting and diagnosis of the disease.

Results

One hundred patients of locally advanced breast cancer were evaluated using standardized questionnaires to assess the delays in diagnosis. Provider delays were found to be significant (the unregistered doctors or quacks being a significant cause of delays). The average time lapse before diagnosis for rural patients was higher (67.5 days) compared to urban patients (53.7 days). The literacy levels of the patients also had a significant impact on the delays at diagnosis. The delay in illiterates was 60.6 days compared to 49.5 days for literates.

Conclusions

The most common factor responsible for delays in reporting and diagnosis was observed to be at the end of the health providers, although illiteracy and lack of adequate healthcare services also contributed significantly. Unregistered medical practitioners or quacks contributed significantly to the delays in reporting and diagnosis of the disease.
Hepcidin in Human Iron Disorders: Diagnostic Implications
Authors: Kroot Joyce JC , Tjalsma Harold , Fleming Robert E , Swinkels Dorine W
Published: October 2011

BACKGROUND

The peptide hormone hepcidin plays a central role in regulating dietary iron absorption and body iron distribution. Many human diseases are associated with alterations in hepcidin concentrations. The measurement of hepcidin in biological fluids is therefore a promising tool in the diagnosis and management of medical conditions in which iron metabolism is affected.

CONTENT

We describe hepcidin structure, kinetics, function, and regulation. We moreover explore the therapeutic potential for modulating hepcidin expression and the diagnostic potential for hepcidin measurements in clinical practice.

Cell-culture, animal, and human studies have shown that hepcidin is predominantly synthesized by hepatocytes, where its expression is regulated by body iron status, erythropoietic activity, oxygen tension, and inflammatory cytokines. Hepcidin lowers serum iron concentrations by counteracting the function of ferroportin, a major cellular iron exporter present in the membrane of macrophages, hepatocytes, and the basolateral site of enterocytes. Hepcidin is detected in biologic fluids as a 25 amino acid isoform, hepcidin-25, and 2 smaller forms, i.e., hepcidin-22 and −20; however, only hepcidin-25 has been shown to participate in the regulation of iron metabolism. Reliable assays to measure hepcidin in blood and urine by use of immunochemical and mass spectrometry methods have been developed. Results of proof-of-principle studies have highlighted hepcidin as a promising diagnostic tool and therapeutic target for iron disorders. However, before hepcidin measurements can be used in routine clinical practice, efforts will be required to assess the relevance of hepcidin isoform measurements, to harmonize the different assays, to define clinical decision limits, and to increase assay availability for clinical laboratories.
Voltage-Gated Na+Channel β1B: A Secreted Cell Adhesion Molecule Involved in Human Epilepsy
Authors: Patino Gustavo A. , Brackenbury William J. , Bao Yangyang , Lopez-Santiago Luis F. , O'Malley Heather A. , Chen Chunling , Calhoun Jeffrey D. , Lafrenière Ron G. , Cossette Patrick , Rouleau Guy A. , Isom Lori L.
Published: October 2011

Scn1b-null mice have a severe neurological and cardiac phenotype. Human mutations inSCN1Bresult in epilepsy and cardiac arrhythmia.SCN1Bis expressed as two developmentally regulated splice variants, β1 and β1B, that are each expressed in brain and heart in rodents and humans. Here, we studied the structure and function of β1B and investigated a novel humanSCN1Bepilepsy-related mutation (p.G257R) unique to β1B. We show that wild-type β1B is not a transmembrane protein, but a soluble protein expressed predominantly during embryonic development that promotes neurite outgrowth. Association of β1B with voltage-gated Na+channels Nav1.1 or Nav1.3 is not detectable by immunoprecipitation and β1B does not affect Nav1.3 cell surface expression as measured by [3H]saxitoxin binding. However, β1B coexpression results in subtle alteration of Nav1.3 currents in transfected cells, suggesting that β1B may modulate Na+current in brain. Similar to the previously characterized p.R125C mutation, p.G257R results in intracellular retention of β1B, generating a functional null allele. In contrast, two otherSCN1Bmutations associated with epilepsy, p.C121W and p.R85H, are expressed at the cell surface. We propose that β1B p.G257R may contribute to epilepsy through a mechanism that includes intracellular retention resulting in aberrant neuronal pathfinding.
Modulation of Gamma and Theta Spectral Amplitude and Phase Synchronization Is Associated with the Development of Visuo-Motor Learning
Authors: Perfetti Bernardo , Moisello Clara , Landsness Eric Carl , Kvint Svetlana , Lanzafame Simona , Onofrj Marco , Di Rocco Alessandro , Tononi Giulio , Ghilardi M. Felice
Published: October 2011

The formation of new motor memories, which is fundamental for efficient performance during adaptation to a visuo-motor rotation, occurs when accurate planning is achieved mostly with feedforward mechanisms. The dynamics of brain activity underlying the switch from feedback to feedforward control is still matter of debate. Based on the results of studies in declarative learning, it is likely that phase synchronization of low and high frequencies as well as their temporal modulation in power amplitude underlie the formation of new motor memories during visuo-motor adaptation. High-density EEG (256 electrodes) was recorded in 17 normal human subjects during adaptation to a visuo-motor rotation of 60° in four incremental steps of 15°. We found that initial learning is associated with enhancement of gamma power in a right parietal region during movement execution as well as gamma/theta phase coherence during movement planning. Late stages of learning are instead accompanied by an increase of theta power over that same right parietal region during movement planning, which is correlated with the degree of learning and retention. Altogether, these results suggest that the formation of new motor memories and, thus, the switch from feedback to feedforward control is associated with the modulation of gamma and theta spectral activities, with respect to their amplitude and phase, during movement planning and execution. Specifically, we propose that gamma/theta phase coupling plays a pivotal role in the integration of a new representation into motor memories.
Hypertonicity Sensing in Organum Vasculosum Lamina Terminalis Neurons: A Mechanical Process InvolvingTRPV1But NotTRPV4
Authors: Ciura Sorana , Liedtke Wolfgang , Bourque Charles W.
Published: October 2011

Primary osmosensory neurons in the mouse organum vasculosum lamina terminalis (OVLT) transduce hypertonicity via the activation of nonselective cation channels that cause membrane depolarization and increased action potential discharge, and this effect is absent in mice lacking expression of the transient receptor potential vanilloid 1 (Trpv1) gene (Ciura and Bourque, 2006). However other experiments have indicated that channels encoded byTrpv4also contribute to central osmosensation in mice (Liedtke and Friedman, 2003; Mizuno et al., 2003). At present, the mechanism by which hypertonicity modulates cation channels in OVLT neurons is unknown, and it remains unclear whetherTrpv1andTrpv4both contribute to this process. Here, we show that physical shrinking is necessary and sufficient to mediate hypertonicity sensing in OVLT neurons isolated from adult mice. Steps coupling progressive decreases in cell volume to increased neuronal activity were quantitatively equivalent whether shrinking was evoked by osmotic pressure or mechanical aspiration. Finally, modulation of OVLT neurons by tonicity or mechanical stimulation was unaffected by deletion oftrpv4but was abolished in cells lackingTrpv1or wild-type neurons treated with the TRPV1 antagonist SB366791. Thus, hypertonicity sensing is a mechanical process requiringTrpv1, but notTrpv4.
Cell Type-Dependent Trafficking of Neuropeptide Y-Containing Dense Core Granules in CNS Neurons
Authors: Ramamoorthy Prabhu , Wang Qian , Whim Matthew D.
Published: October 2011

Neuropeptide transmitters are synthesized throughout the CNS and play important modulatory roles. After synthesis in the neuronal cell body, it is generally assumed that peptides are transported to nonspecialized sites of release. However, apart from a few cases, this scenario has not been thoroughly examined. Using wild-type and NPY(GFP) transgenic mice, we have studied the subcellular distribution of neuropeptide Y (NPY), a prototypical and broadly expressed neuropeptide. NPY puncta were found in the dendrites and axons of hippocampal GABAergic interneuronsin situ. In contrast in hypothalamic GABAergic interneurons, NPY was restricted to the axon. Surprisingly this differential trafficking was preserved when the neurons were maintainedin vitro. When hippocampal and hypothalamic neurons were transfected with NPY-Venus, the distribution of the fluorescent puncta replicated the cell type-specific distribution of endogenous neuropeptide Y. The NPY puncta in the axons of hippocampal and hypothalamic neurons colocalized with the sites of classical transmitter release (identified by staining for synapsin and the vesicular GABAergic transporter, VGAT). In hippocampal neurons, most of the postsynaptic NPY puncta were clustered opposite synapsin-containing varicosities. When neurons were stained for a second neuropeptide, agouti-related protein, immunoreactivity was found in the axon and dendrites of hippocampal neurons but only in the axons of hypothalamic neurons, thus mimicking the polarized distribution of NPY. These results indicate that the trafficking of neuropeptide-containing dense core granules is markedly cell type specific and is not determined entirely by the characteristics of the particular peptide per se.
Glucagon-Like Peptide 1 Receptors in Nucleus Accumbens Affect Food Intake
Authors: Dossat Amanda M. , Lilly Nicole , Kay Kristen , Williams Diana L.
Published: October 2011

Central glucagon-like peptide 1 receptor (GLP-1R) stimulation suppresses food intake, and hindbrain GLP-1 neurons project to numerous feeding-relevant brain regions. One such region is the nucleus accumbens (NAc), which plays a role in reward and motivated behavior. Using immunohistochemical and retrograde tracing techniques in rats, we identified a robust projection from GLP-1 neurons in the nucleus of the solitary tract to the NAc. We hypothesized that activation of NAc GLP-1Rs suppresses feeding. When injected into the NAc core of rats at doses subthreshold for effect when administered to the lateral ventricle, GLP-1 significantly reduced food intake relative to vehicle at 1, 2, and 24 h posttreatment. The same doses had no effect when injected into the NAc shell. NAc core treatment with ventricle-subthreshold doses of the GLP-1R antagonist exendin (9–39) caused significant hyperphagia at 2 h posttreatment, suggesting that endogenous stimulation of NAc core GLP-1Rs plays a role in limiting food intake. It has been suggested that GLP-1 can cause nausea, but we found that NAc core administration of GLP-1 did not cause a conditioned taste aversion to saccharin, suggesting that the anorexic effect of NAc core GLP-1 is not caused by malaise. Finally, we observed that NAc core injection of GLP-1 significantly increased c-Fos expression in the NAc core. We conclude that that GLP-1Rs in the NAc play a physiologic role in food intake control, and suggest that the GLP-1 projection to NAc core may link satiation signal processing in the hindbrain with forebrain processing of food reward.
Dopaminergic Striatal Innervation Predicts Interlimb Transfer of a Visuomotor Skill
Authors: Isaias Ioannis U. , Moisello Clara , Marotta Giorgio , Schiavella Mauro , Canesi Margherita , Perfetti Bernardo , Cavallari Paolo , Pezzoli Gianni , Ghilardi M. Felice
Published: October 2011

We investigated whether dopamine influences the rate of adaptation to a visuomotor distortion and the transfer of this learning from the right to the left limb in human subjects. We thus studied patients with Parkinson disease as a putativein vivomodel of dopaminergic denervation. Despite normal adaptation rates, patients showed a reduced transfer compared with age-matched healthy controls. The magnitude of the transfer, but not of the adaptation rate, was positively predicted by the values of dopamine-transporter binding of the right caudate and putamen. We conclude that striatal dopaminergic activity plays an important role in the transfer of visuomotor skills.
MicroRNA-137/181c Regulates Serine Palmitoyltransferase and In Turn Amyloid β, Novel Targets in Sporadic Alzheimer's Disease
Authors: Geekiyanage Hirosha , Chan Christina
Published: October 2011

The contribution of mutations in amyloid precursor protein (APP) and presenilin (PSEN) to familial Alzheimer's disease (AD) is well established. However, little is known about the molecular mechanisms leading to amyloid β (Aβ) generation in sporadic AD. Increased brain ceramide levels have been associated with sporadic AD, and are a suggested risk factor. Serine palmitoyltransferase (SPT) is the first rate-limiting enzyme in thede novoceramide synthesis. However, the regulation of SPT is not yet understood. Evidence suggests that it may be posttranscriptionally regulated. Therefore, we investigated the role of miRNAs in the regulation of SPT and amyloid β (Aβ) generation. We show that SPT is upregulated in a subgroup of sporadic AD patient brains. This is further confirmed in mouse model studies of risk factors associated with AD. We identified that the loss of miR-137, -181c, -9, and 29a/b-1 increases SPT and in turn Aβ levels, and provides a mechanism for the elevated risk of AD associated with age, high-saturated-fat diet, and gender. Finally, these results suggest SPT and the respective miRNAs may be potential therapeutic targets for sporadic AD.
Entwicklung eines Biofeedback-Systems zur Regelung der Leistung, Herzrate und Sauerstoffaufnahme für robotische Kipptisch-Therapie
Authors: Bichsel Lukas , Sommer. Michael , Hunt Kenneth J.
Published: October 2011

Jüngere Therapieformen für Patienten mit Querschnittlähmung oder Schlaganfall, insbesondere zur Therapie von Orthostatischer Hypotonie, sehen Vertikalisierung und passive Beinbewegung vor, u. a. unter Verwendung automatischer Kipptische mit robotischen Beinantrieben. Dieser Beitrag schlägt die Weiterentwicklung eines solchen Gerätes vor, um dem Patienten aktive Teilnahme an der Therapie zu ermöglichen, wobei er willentlich seine eigene Leistung regeln kann, basierend auf visuellem Biofeedback. Gleichzeitig wird seine physiologische Belastung via Herzrate bzw. Sauerstoffaufnahme digital geregelt, durch Anpassung der visualisierten Soll-Leistung. Dadurch könnte die individuelle kardiopulmonale Leistungsfähigkeit des Patienten gezielt gesteigert werden. Diese Weiterentwicklung wurde prototypisch an einem Kipptisch vorgenommen, durch Einbau geeigneter Sensoren und Peripheriegeräte für digitale Regelung, Bedienung und Visualisierung. Tests im Rahmen einer rein technischen Validierungsstudie mit mehreren körperlich gesunden männlichen Testpersonen lieferten positive Ergebnisse, sowohl hinsichtlich der willentlichen Leistungsregelung der Individuen als auch des Regelverhaltens der digitalen Belastungsregler.
Probing of Ag-based Resistive Switching on the Nanoscale
Authors: Geresdi A. , Halbritter A. , Szilágyi E. , Mihály G.
Published: October 2011

We study the switching characteristics of nanoscale junctions between a metallic tip and a silver film covered by a thin Ag2S ionic conductor layer. Resistive switching phenomena are studied on samples of various Ag2S layer thicknesses. Metallic and semiconductor behavior are distinguished by current-voltage characteristics measured at room temperature and at 4.2 K.