bluuebunny/crossref_metadata_2025_split huggingface dataset:
Claudin 28b and F-actin are involved in rainbow trout gill pavement cell tight junction remodeling under osmotic stress
Authors: Sandbichler Adolf Michael , Egg Margit , Schwerte Thorsten , Pelster Bernd 
Published: April 2011

SUMMARYPermeability of rainbow trout gill pavement cells cultured on permeable supports (single seeded inserts) changes upon exposure to freshwater or treatment with cortisol. The molecular components of this change are largely unknown, but tight junctions that regulate the paracellular pathway are prime candidates in this adaptational process. Using differential display polymerase chain reaction we found a set of 17 differentially regulated genes in trout pavement cells that had been exposed to freshwater apically for 24 h. Five genes were related to the cell–cell contact. One of these genes was isolated and identified as encoding claudin 28b, an integral component of the tight junction. Immunohistochemical reactivity to claudin 28b protein was concentrated in a circumferential ring colocalized to the cortical F-actin ring. To study the contribution of this isoform to changes in transepithelial resistance and Phenol Red diffusion under apical hypo-or hyperosmotic exposure we quantified the fluorescence signal of this claudin isoform in immunohistochemical stainings together with the fluorescence of phalloidin-probed F-actin. Upon hypo-osmotic stress claudin 28b fluorescence and epithelial tightness remained stable. Under hyperosmotic stress, the presence of claudin 28b at the junction significantly decreased, and epithelial tightness was severely reduced. Cortical F-actin fluorescence increased upon hypo-osmotic stress, whereas hyperosmotic stress led to a separation of cortical F-actin rings and the number of apical crypt-like pores increased. Addition of cortisol to the basolateral medium attenuated cortical F-actin separation and pore formation during hyperosmotic stress and reduced claudin 28b in junctions except after recovery of cells from exposure to freshwater. Our results showed that short-term salinity stress response in cultured trout gill cells was dependent on a dynamic remodeling of tight junctions, which involves claudin 28b and the supporting F-actin ring.
The effect of developmental stage on the sensitivity of cell and body size to hypoxia inDrosophila melanogaster
Authors: Heinrich Erica C. , Farzin Manoush , Klok C. Jaco , Harrison Jon F. 
Published: April 2011

SUMMARYAnimals reared in hypoxic environments frequently exhibit smaller body sizes than when reared under normal atmospheric oxygen concentrations. The mechanisms responsible for this widely documented pattern of body size plasticity are poorly known. We studied the ontogeny of responses of Drosophila melanogaster adult body size to hypoxic exposure. We hypothesized that there may be critical oxygen-sensitive periods during D. melanogaster development that are primarily responsive to body size regulation. Instead, our results showed that exposure to hypoxia (an atmospheric partial pressure of oxygen of 10 kPa) during any developmental stage (embryo, larvae and pupae) leads to smaller adult size. However, short hypoxic exposures during the late larval and early pupal stages had the greatest effects on adult size. We then investigated whether the observed reductions in size induced by hypoxia at various developmental stages were the result of a decrease in cell size or cell number. Abdominal epithelial cells of flies reared continuously in hypoxia were smaller in mean diameter and were size-limited compared with cells of flies reared in normoxia. Flies reared in hypoxia during the embryonic, larval or pupal stage, or during their entire development, had smaller wing areas than flies reared in normoxia. Flies reared during the pupal stage, or throughout development in hypoxia had smaller wing cells, even after controlling for the effect of wing size. These results suggest that hypoxia effects on the body size of D. melanogaster probably occur by multiple mechanisms operating at various developmental stages.
Rainbow trout consume less oxygen in turbulence: the energetics of swimming behaviors at different speeds
Authors: Taguchi Masashige , Liao James C. 
Published: April 2011

SUMMARYMeasuring the rate of consumption of oxygen () during swimming reveals the energetics of fish locomotion. We show that rainbow trout have substantially different oxygen requirements for station holding depending on which hydrodynamic microhabitats they choose to occupy around a cylinder. We used intermittent flow respirometry to show that an energetics hierarchy, whereby certain behaviors are more energetically costly than others, exists both across behaviors at a fixed flow velocity and across speeds for a single behavior. At 3.5 L s–1 (L is total body length) entraining has the lowest , followed by Kármán gaiting, bow waking and then free stream swimming. As flow speed increases the costs associated with a particular behavior around the cylinder changes in unexpected ways compared with free stream swimming. At times, actually decreases as flow velocity increases. Entraining demands the least oxygen at 1.8 L s–1 and 3.5 L s–1, whereas bow waking requires the least oxygen at 5.0 L s–1. Consequently, a behavior at one speed may have a similar cost to another behavior at another speed. We directly confirm that fish Kármán gaiting in a vortex street gain an energetic advantage from vortices beyond the benefit of swimming in a velocity deficit. We propose that the ability to exploit velocity gradients as well as stabilization costs shape the complex patterns of oxygen consumption for behaviors around cylinders. Measuring for station holding in turbulent flows advances our attempts to develop ecologically relevant approaches to evaluating fish swimming performance.
Atypical properties of release and short-term depression at a specialized nicotinic synapse in the Mauthner cell network
Authors: Gelman Simon , Grove Charlotte L. , Faber Donald S. 
Published: April 2011

SUMMARY
Many synapses exhibit temporally complex forms of activity-dependent short-term synaptic plasticity. The diversity of these phenomena reflects the evolutionary specialization of synapses within networks. We examined the properties of transmission and plasticity, in vivo, at an identified, specialized axo-axonic nicotinic synapse between the goldfish Mauthner cell and one of its targets, the cranial relay neuron (CRN), using intracellular paired recordings and low frequency (0.33–2 Hz) train stimulations. Depression of successive excitatory postsynaptic potentials (EPSPs), which dominates short-term plasticity, had two components. A fast component reduced the amplitude of EPSP2, to less than 50% of EPSP1. A slow component produced an additional 10–30% of amplitude reduction and developed with a time constant of tens of seconds. The latencies of the later depressed responses were ∼0.1 ms longer than that of EPSP1, suggesting a reduced release probability. The Ca2+ chelators EGTA and BAPTA, injected presynaptically, reduced all EPSPs and slowed development of the second component of depression. Interestingly, spike broadening, produced by injecting K+ channel blockers, reduced release, but accelerated the kinetics of the slow component. Finally, Ba2+ in the external medium enhanced release, and reduced the first component and slowed the development of the second component of depression. Taken together, these last two results, which are in contrast to observations at other synapses, and the two-component depression suggest atypical release properties at the output synapses of the Mauthner cell, which triggers an escape behavior. We suggest that the second component of depression provides an additional safety factor to prevent repetitive firing of the CRN.
Synthesis and Properties of 1,3-Dithiole[4]dendralenes, in Which Two Thiophene Rings Are Inserted
Authors: Nishiwaki Masataka , Tezuka Mami , Shirahata Takashi , Misaki Yohji 
Published: April 2011

Abstract
Novel 1,3-dithiole[4]dendralene derivatives 3 with two thiophene spacers were synthesized. Cyclic voltammetry and spectroelectrochemistry suggested the dications of most derivatives of 3 have dimeric thiophene–quinoid radical cation structures, while tetramethyltetrakis(methoxycarbonyl) derivative 3Bd adopts a vinylogous TTF dication structure.
Different Chiral Selective Recognition/Extraction of (n,m)Single-walled Carbon Nanotubes Using Copolymers Carrying a Carbazole or Fluorene Moiety
Authors: Ozawa Hiroaki , Fujigaya Tsuyohiko , Song Suhee , Suh Hongsuk , Nakashima Naotoshi 
Published: April 2011

Abstract
We describe the finding that copolymers having a long-double chain carbazole or fluorene group connected to benzothiadiazole with thiophene linkers show a different chiral selective (n,m)single-walled carbon nanotube (SWNT) solubilization behavior which was revealed by 2D photoluminescence and vis–near IR spectroscopies. We also carried out molecular mechanical simulations to understand the difference in the chiral selective solubilization behavior.
Non-invasive evaluation of the coronary venous system in patients with chronic systolic heart failure by 64-detector computed tomography
Authors: Cubuk Rahmi , Aydin Alper , Tasali Nuri , Yilmazer Serdar , Celik Levent , Dagdeviren Bahadir , Guney Sefik 
Published: April 2011

Background Imaging coronary venous systems to guide transcatheter cardiac interventions are becoming increasingly important, particularly in heart failure patients who are selected for cardiac resynchronization therapy (CRT). Failure of left ventricular (LV) lead placement during the procedure has been attributed to the inability to insert catheters into the coronary sinus and the lack of suitable side branches. Purpose To comparatively assess the value of a 64-detector MDCT examination in visualizing the cardiac veins and evaluating the morphological characteristics of the coronary venous system in patients with and without chronic systolic heart failure (SHF). Material and Methods A 64-detector MDCT examination of the heart was performed in 26 consecutive patients (five women, 21 men; mean age 57.80 ± 12.05 years; range 27–81 years) with chronic SHF. The morphological characteristics of the coronary venous system, such as the diameter, the distances between the venous tributaries, the angle and the tortuosity, were evaluated. The group was compared with a subgroup of 52 subjects without SHF (LV ejection fraction >40%) matched for age, sex, and the risk factors for coronary artery disease. Results The coronary sinus (CS), great cardiac vein (GCV), anterior interventricular vein (AIV), and posterior interventricular vein (PIV) were visualized in all 78 individuals. The posterior vein of the left ventricle (PVLV) (63/78), left marginal vein (LMV) (72/78), and the small cardiac vein (SCV) (50/78) were visualized in SHF and control patients (p = NS). The lengths between venous tributaries were higher (p > 0.05) and more dilated (P < 0.001 for CS, GCV, AIV, PVLV, LMV; p = 0.001 for PIV) in the cases with SHF compared with the control population. The angle between the CS-GCV axis and the venous branches was wider (p = 0.02 for LMV and PIV, p = 0.001 for PVLV) and did not have any correlation with the LV diameter in cases with SHF. There was no difference between the SHF and control groups in terms of the tortuosity of PVLV and LMV (p = NS). Conclusion The study demonstrated an increase in the diameters, lengths, and angulations with the CS-GCV axis of the coronary veins in cases with SHF. A 64-detector MDCT is a feasible tool for non-invasive evaluation of the coronary venous system and may provide considerable information regarding numbers and morphology of coronary veins before percutaneous transcatheter cardiac therapy.
Optimization of contrast medium protocol in CT coronary arteriography: constant injection dose rate adapted to body weight
Authors: Cao Lizhen , Du Xiangying , Li Pengyu , Sun Zheng , Zhang Qiuhang , Li Kuncheng 
Published: April 2011

Background Fixed dose contrast medium (CM) injection protocols are often used in CT coronary arteriography (CTCA). However, vascular enhancement is related to body weight and injection dose rate. Purpose To compare aortic enhancement and coronary imaging quality between a fixed dose CM injection protocol and one adapted to body weight with a constant injection dose rate in mg I/kg/s. Material and Methods One hundred consecutive patients undergoing CTCA were randomized to two groups; group I received 65 mL CM (370 mg I/mL) at 5 mL/s and group II received 0.9 mL CM (370 mg I/mL) per kg during 12 s resulting in a constant injection dose rate of 28 mg I/kg/s.The groups were re-divided according to body weight: IA ≤ 70 kg, IB >70 kg, IIA ≤ 70 kg, IIB >70 kg. Aortic attenuation was measured and coronary imaging quality was graded using a four-grade scale. Results The resulting mean CM dose, aortic attenuation and score of coronary imaging quality in groups IA/IB/IIA/IIB were 24/24/19/27 g I, 437/403/448/440 HU and 2.8/2.3/2.7/2.6, respectively. CM dose and aortic attenuation were significantly different between groups IA and IIA ( p < 0.001, p = 0.01), as well as between groups IB and IIB ( p < 0.001, p < 0.001).There was no statistically significant difference regarding coronary imaging quality between groups IA and IIA ( p = 0.30), while there was a significant difference between groups IB and IIB ( p < 0.001). Conclusion In CTCA, body weight-adapted CM injection protocols using a constant dose rate can help save CM doses in slimmer patients and improve aortic enhancement and coronary imaging quality in heavier patients compared to fixed dose protocols.
The CT flare response of metastatic bone disease in prostate cancer
Authors: Messiou Christina , Cook Gary , Reid Alison HM , Attard Gerhardt , Dearnaley David , de Bono Johann S , de Souza Nandita M 
Published: April 2011

Background New or worsening bone lesions in patients responding to treatment, known as the flare phenomenon is well described on 99mTc-MDP bone scintigraphy, but to our knowledge has not previously been described on CT. The appearance of new or worsening bone sclerosis on CT in patients with prostate cancer may therefore be erroneously classified as disease progression. Purpose To assess the incidence of osteoblastic healing flare response at 3-month CT assessment in patients with castrate-resistant prostate cancer and to identify associated features that enable differentiation from progressive metastatic bone disease at 3 months. Material and Methods CT scans of 67 patients with castrate-resistant prostate cancer undergoing treatment were reviewed by a radiologist blinded to clinical outcome. Changes in number, size, and density of metastatic bone lesions were documented and Response Evaluation Criteria in Solid Tumours (RECIST) in soft tissue lesions, alkaline phosphatase, prostate specific antigen, and 99mTc-MDP bone scans were used for correlation. Results Of the 39 patients who had 3- and 6-month follow-up, eight patients (21%) demonstrated an increase in number, size, or density of sclerotic lesions on the 3-month CT scan despite improvement in PSA and soft tissue lesions. Three out of eight patients (8%) maintained partial response/remained stable at follow-up and were defined as showing a flare response: in this group bone metastases evident on CT showed a qualitative and quantitative increase in density and no lesions faded at 3 months. In contrast, in all patients who progressed at 3 months by PSA/RECIST criteria ( n = 8) bone lesions showed a mixed pattern with some lesions increasing and others decreasing in density. Conclusion The incidence of flare response of metastatic bone disease evident at 3-month post-treatment CT in patients with prostate cancer undergoing systemic treatment is 8%. In patients with falling PSA and stable/responding soft tissue disease at 3 months an increase in bone sclerosis in the absence of fading bone metastases can be interpreted as flare and is likely to represent a response.
Unenhanced fat fraction ratios obtained by MR and enhanced T2* values with liver-specific MR contrast agents for diagnosis of non-alcoholic steatohepatitis in rats
Authors: Okada Masahiro , Katsube Takashi , Kumano Seishi , Kagawa Yuki , Araki Tetsuro , Tsuda Natsuko , Okuaki Tomoyuki , Imaoka Izumi , Tanigawa Noboru , Ishii Kazunari , Murakami Takamichi 
Published: April 2011

Background Non-invasive MR imaging is expected to be used for accurate diagnosis and quantification of non-alcoholic steatohepatitis (NASH), because NASH is a progressive fatty liver disease. New MR techniques, such as fat fraction ratio (FFR) and T2* value measurement, have attracted an increasing attention, because those techniques can measure quantitative parameters of fibrosis, fat and iron deposition in the liver. Purpose To investigate the potential of FFR and T2* value in NASH with pre-enhancement, gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA) or super-paramagnetic iron oxide (SPIO)-enhanced MRI. Material and Methods Twenty-eight rats were divided equally into four groups (one control group and three NASH groups). All rats underwent unenhanced, Gd-EOB-DTPA, and SPIO-enhanced MRI. The T2* value of the liver was measured for each image sequence, and then changes in T2* values before and after each injection were analyzed using Dunnett's test. The reduction rate of T2* value before and 13 min after injection of Gd-EOB-DTPA or SPIO was analyzed using Mann-Whitney's U test. Moreover, FFR of the liver was measured before enhancement, and the relationship between fat fraction and the calculated fat area percentage on a pathological specimen was examined using Spearman's correlation test. Results On pre-enhancement, FFR and T2* value were 26.0% ± 12.0% and 21.5 ± 4.2 ms for all NASH groups, and 0.9% ± 0.5% and 30.8 ±−5.5 ms for control, respectively. Both FFR and T2* values were significantly different between the NASH and control groups. The reduction rate of T2* value was significantly lower in the NASH groups than in the control group on SPIO-enhanced MRI, though there was no significant difference on Gd-EOB-DTPA-enhanced MRI. FFR was correlated with the calculated fat area percentage for the pathological specimen. Conclusion Pre-enhancement FFR, T2* value measurement and reduction rate of T2* value on SPIO-enhanced MRI may help estimate the progress of liver fat deposition and fibrosis in NASH.
High resolution spiral CT for determining the malignant potential of solitary pulmonary nodules: refining and testing the test
Authors: Harders Stefan Walbom , Madsen Hans Henrik , Rasmussen Torben Riis , Hager Henrik , Rasmussen Finn 
Published: April 2011

Background A solitary pulmonary nodule (SPN) may represent early stage lung cancer. Lung cancer is a devastating disease with an overall 5-year mortality rate of approximately 84% but with early detection and surgery as low as 47%. Currently a contrast-enhanced multiple-row detector CT (MDCT) scan is the first examination when evaluating patients with suspected lung cancer. Purpose To apply an additional high resolution CT (HRCT) to SPNs to test whether certain morphological characteristics are associated with malignancy, to assess the diagnostic accuracy of HRCT in the characterization of SPNs, and to address the reproducibility of all measures. Material and Method Two hundred and thirteen participants with SPNs were included in a follow-up study. Blinded HRCT images were assessed with regard to margin risk categories (MRCs), calcification patterns and certain other characteristics and overall malignancy potential ratings (MPRs) were given. Morphological characteristics were tested against reference standard and ROC methodology was applied to assess diagnostic accuracy. Reproducibility was measured with Kappa statistics and 95% confidence intervals were computed for all results. Histopathology (90%) and CT follow-up (10%) were used as reference standard. Results MRCs ( P < 0.001), calcification patterns ( P = 0.003), and pleural retraction ( P < 0.001) were all statistically significantly associated to malignancy. Reproducibility was moderate to substantial. Sensitivity, specificity, and overall diagnostic accuracy of HRCT were 98%, 23% and 87%, respectively. Reproducibility was substantial. Conclusion Statistically significant associations between SPN MRCs, calcification patterns, pleural retraction and malignancy were found. HRCT yielded a very high sensitivity and a somewhat lower specificity for malignancy. Reproducibility was high.
Baseline incidence and severity of renal insufficiency evaluated by estimated glomerular filtration rates in patients scheduled for contrast-enhanced CT
Authors: Utsunomiya Daisuke , Yanaga Yumi , Awai Kazuo , Oda Seitaro , Funama Yoshinori , Namimoto Tomohiro , Yamashita Yasuyuki 
Published: April 2011

Background Although pre-existing renal insufficiency (RI) is the most important risk factor for contrast-induced nephropathy (CIN), the background distribution of baseline renal function has not been investigated thoroughly in patients scheduled for contrast-enhanced CT. Purpose To investigate the incidence and severity of baseline RI evaluated by estimated glomerular filtration rates (eGFR) in patients who underwent contrast-enhanced CT at an academic center. Material and Methods A total of 6586 patients (3630 men and 2956 women; mean age 57.0 ± 11.9 years) who underwent contrast-enhanced CT between January and December 2008 were retrospectively studied. Of these, 829 had cardiovascular diseases (CVD), 5116 had oncologic diseases, 178 had diabetes mellitus (DM), and 1572 had chronic liver disease (CLD). The eGFR (mL/min/1.73 m2) was calculated from their serum creatinine level. Mild, moderate-a, moderate-b, and severe RI were recorded at 60 < =eGFR < 90, 45 < =eGFR < 60, 30 < =eGFR < 45 and eGFR < 30, respectively. Results Of the 6586 patients, 1.6%, 3.7%, 13.7%, and 54.2% were judged to present with severe, moderate-b, moderate-a, and mild RI, respectively. While moderate-b-to-severe RI was recorded in 133 (3.2%) of 4161 patients aged 70 years or less, it was observed in 218 (9.0%) of the 2425 patients who were 71 years or older. Among the 829 CVD patients, 9.9% manifested moderate-b-to-severe- and 73.0% mild-to-moderate-a RI. The corresponding rates were 4.4% and 68.9% for oncologic disease, 16.9% and 61.2% for DM, and 4.8% and 71.5% for CLD patients. By univariate analysis, there was a significant association between moderate-b-to-severe RI and the advanced age, CVD, DM, and non-oncologic disease. Multivariate analysis showed that the advanced age, DM, and non-oncologic disease were statistically associated with moderate-b-to-severe RI. Conclusion The incidence of RI of eGFR < 45mL/min/1.73 m2 at baseline was high in patients with advanced age, CVD and DM and in patients without oncologic disease.