bluuebunny/crossref_metadata_2025_split huggingface dataset:
Similar expression of through‐and‐through fluid movement along orthograde apical plugs of MTA Bio™ and white Portland cement
Authors: De‐Deus G. , Audi C. , Murad C. , Fidel S. , Fidel R. 
Published: September 2008

AbstractAim  To compare the sealing ability of four hydraulic cements when used as an apical plug in teeth with wide‐open apices.Methodology  A sample of 70 maxillary central incisors were divided into four groups (n = 15) and a further 10 teeth served as controls. An artificial open apex was created in the teeth using Gates Glidden drills numbers 6‐1 in a crown‐down manner until the size 1 bur passed through the foramen. A divergent open apex was prepared to a size of 1.24 mm at the foramen by retrograde apical transportation using a number 8 (0.60) Profile Series 29 0.4 taper instrument inserted to the length of the cutting blade. In G1, the open apices were repaired with WMTA Angelus whilst in G2, G3 and G4 MTA Bio™, Pro‐Root MTA and Portland cement was employed respectively. Each root was assembled in a hermetic cell to allow the evaluation of fluid filtration. Leakage was measured by the movement of an air bubble travelling within a pipette connected to the teeth. Measurements of the air bubble movement were made after 10 min at a constant pressure of 50 cm H2O. The Kruskal–Wallis H‐test was applied to the fluid flow data to detect differences between the experimental groups (P < 0.05).Results  Fluid movement occurred in every sample but was variable in all the experimental groups, ranging from 0.61 to 2.45 μL min−1. There was no significant difference in mean fluid flow between the experimental groups (P > 0.05).Conclusions  Fluid movement through teeth with open apices and filled with four hydraulic cements was similar. All cements allowed fluid movement.
A preliminary study of the use of peripheral quantitative computed tomography for investigating root canal anatomy
Authors: Sberna M. T. , Rizzo G. , Zacchi E. , Capparè P. , Rubinacci A. 
Published: September 2008

AbstractAim  To evaluate the use of peripheral quantitative computed tomography (pQCT) for qualitative and quantitative analysis of root canal anatomy and for assessing the extent of canal enlargement during root canal instrumentation.Summary  The volume variation achieved by S1 ProTaper instruments in the coronal third of the root canals was analysed using peripheral computed tomography. The tooth was scanned in the horizontal plane producing 36 consecutive cross‐sectional images. All images were the result of 360 projections with a section thickness of 250 μm, a distance between slices of 0.5 mm and an in‐plane pixel size of 70 × 70 μm. The evaluation was completed before and after S1 ProTaper instrumentation (with or without circumferential filing) of one root canal of a freshly extracted maxillary first premolar tooth. The acquired images were realigned geometrically and processed using a 3D visualization software. pQCT scanning allowed 3D reconstruction of the root canal anatomy and the assessment of the extent of canal enlargement during root canal instrumentation with lateral displacement of canal walls and hence volume change being greater than the coefficient of variation. The densitometry evaluation showed uniform density along the root canal wall.Key learning points • pQCT scanning allowed 3D reconstruction of the root canal anatomy and the assessment of the extent of canal enlargement during root canal instrumentation.• pQCT shows promise for allowing qualitative and quantitative analysis of endodontic procedures.
Are medical students socially exclusive? A comparison with economics students
Authors: Blakey Hannah , Blanshard Eve , Cole Helen , Leslie Fiona , Sen Rosamund 
Published: September 2008

Context  Medical students have long been perceived as socially segregated from other students. However, the evidence for this is mainly anecdotal. This study investigates this issue by comparing medical students with economics students.Methods  Questionnaires measuring objective and subjective social life patterns were completed by 149 medical and 149 economics students at a campus‐based university in the UK.Results  Medical students drew significantly more of their close friends and housemates from among students on the same course than economics students. Significantly more medical than economics students had a partner on the same course, participated in departmental sports clubs and societies, and felt separated from the rest of university life. Commonly reported reasons for this separation among medical students were high workloads, that the medical school was located outside the main campus, and high numbers of contact hours, some of which took place at sites outside the university.Discussion  Medical students are more socially exclusive than economics students, which may lead to ‘in‐group’ attitudes and behaviours. This is educationally important and may affect their future professionalism. Universities should be aware of the issues involved when planning curricula, timetables, welfare initiatives and campus design. Prospective medical students should be informed of the social consequences of studying medicine.
Nitric oxide‐induced bacteriostasis and modification of iron‐sulphur proteins in Escherichia coli
Authors: Ren Binbin , Zhang Nianhui , Yang Juanjuan , Ding Huangen 
Published: September 2008

SummaryThe nitric oxide (NO) cytotoxicity has been well documented in bacteria and mammalian cells. However, the underlying mechanism is still not fully understood. Here we report that transient NO exposure effectively inhibits cell growth of Escherichia coli in minimal medium under anaerobic growth conditions and that cell growth is restored when the NO‐exposed cells are either supplemented with the branched‐chain amino acids (BCAA) anaerobically or returned to aerobic growth conditions. The enzyme activity measurements show that dihydroxyacid dehydratase (IlvD), an iron‐sulphur enzyme essential for the BCAA biosynthesis, is completely inactivated in cells by NO with the concomitant formation of the IlvD‐bound dinitrosyl iron complex (DNIC). Fractionation of the cell extracts prepared from the NO‐exposed cells reveals that a large number of different protein‐bound DNICs are formed by NO. While the IlvD‐bound DNIC and other protein‐bound DNICs are stable in cells under anaerobic growth conditions, they are efficiently repaired under aerobic growth conditions even without new protein synthesis. Additional studies indicate that l‐cysteine may have an important role in repairing the NO‐modified iron‐sulphur proteins in aerobically growing E. coli cells. The results suggest that cellular deficiency to repair the NO‐modified iron‐sulphur proteins may directly contribute to the NO‐induced bacteriostasis under anaerobic conditions.
Carbon monoxide enhances salt tolerance by nitric oxide‐mediated maintenance of ion homeostasis and up‐regulation of antioxidant defence in wheat seedling roots
Authors: XIE YANJIE , LING TENGFANG , HAN YI , LIU KAILI , ZHENG QINGSONG , HUANG LIQIN , YUAN XINGXING , HE ZIYI , HU BING , FANG LEI , SHEN ZHENGUO , YANG QING , SHEN WENBIAO 
Published: September 2008

ABSTRACTSalt stress induced an increase in endogenous carbon monoxide (CO) production and the activity of the CO synthetic enzyme haem oxygenase (HO) in wheat seedling roots. In addition, a 50% CO aqueous solution, applied daily, not only resulted in the enhancement of CO release, but led to a significant reversal in dry weight (DW) and water loss caused by 150 mm NaCl treatment, which was mimicked by the application of two nitric oxide (NO) donors sodium nitroprusside (SNP) and diethylenetriamine NO adduct (DETA/NO). Further analyses showed that CO, as well as SNP, apparently up‐regulated H+‐pump and antioxidant enzyme activities or related transcripts, thus resulting in the increase of K/Na ratio and the alleviation of oxidative damage. Whereas, the CO/NO scavenger haemoglobin (Hb), NO scavenger or synthetic inhibitor methylene blue (MB) or NG‐nitro‐l‐arginine methyl ester hydrochloride (l‐NAME) differentially blocked these effects. Furthermore, CO was able to mimic the effect of SNP by strongly increasing NO release in the root tips, whereas the CO‐induced NO signal was quenched by the addition of l‐NAME or cPTIO, the specific scavenger of NO. The results suggested that CO might confer an increased tolerance to salinity stress by maintaining ion homeostasis and enhancing antioxidant system parameters in wheat seedling roots, both of which were partially mediated by NO signal.
Root of edaphically controlled Proteaceae turnover on the Agulhas Plain, South Africa: phosphate uptake regulation and growth
Authors: SHANE MICHAEL W. , CRAMER MICHAEL D. , LAMBERS HANS 
Published: September 2008

ABSTRACTThe influence of phosphorus (P) availability on growth and P uptake was investigated in South African Proteaceae: (1) Protea compacta R.Br., endemic on severely nutrient‐impoverished colluvial sands; (2) Protea obtusifolia Bueck ex Meissner; and (3) Leucadendron meridianum I. J. Williams, the latter both endemic on comparatively fertile limestone‐derived soils. Plants were grown hydroponically in 1000 L tanks at 0.01, 0.1 or 1.0 µm P for 14 weeks. Biomass accumulation was influenced by P availability, doubling as [P] increased from 0.1 to 1.0 µm. Total biomass was greatest for P. compacta, but L. meridianum and P. obtusifolia had two to four times greater relative biomass accumulation at 0.1 and 1.0 µm[P]. Proteoid root clusters developed at both 0.01 and 0.1 µm[P], but were suppressed at 1.0 µm[P]; this was a 10‐fold lower [P] than previously reported to inhibit cluster root formation. Rates of net P uptake at 5 µm P decreased in response to increased P availability from 0.01 to 1.0 µm P. Significant between‐species differences in rates of P uptake and capacity to down‐regulate P uptake were observed: P. compacta < P. obtusifolia < L. meridianum. The species responses are discussed in terms of adaptation to mosaics in soil P availability and the high beta diversity in the natural habitat.
The role of ultraviolet radiation, photosensitizers, reactive oxygen species and ester groups in mechanisms of methane formation from pectin
Authors: MESSENGER DAVID J. , MCLEOD ANDY R. , FRY STEPHEN C. 
Published: September 2008

ABSTRACTUltraviolet (UV) radiation has recently been demonstrated to drive an aerobic production of methane (CH4) from plant tissues and pectins, as do agents that generate reactive oxygen species (ROS)in vivoindependently of UV. As the major building‐blocks of pectin do not absorb solar UV found at the earth's surface (i.e. >280 nm), we explored the hypothesis that UV radiation affects pectin indirectly via generation of ROS which themselves release CH4from pectin. Decreasing the UV absorbance of commercial pectin by ethanol washing diminished UV‐dependent CH4production, and this was restored by the addition of the UV photosensitizer tryptophan. Certain ROS scavengers [mannitol, a hydroxyl radical (•OH) scavenger; 1,4‐diazabicyclo[2.2.2] octane; and iodide] strongly inhibited UV‐induced CH4production from dry pectin. Furthermore, pectin solutions emitted CH4in darkness upon the addition of•OH, but not superoxide or H2O2. Model carbohydrates reacted similarly if they possessed —CH3groups [e.g. methyl esters or (more weakly) acetyl esters but not rhamnose]. We conclude that UV evokes CH4production from pectic methyl groups by interacting with UV photosensitizers to generate•OH. We suggest that diverse processes generating•OH could contribute to CH4emissions independently of UV irradiation, and that environmental stresses and constitutive physiological processes generating ROS require careful evaluation in studies of CH4formation from foliage.
HEPATITIS C AND ADDICTION: Chronic viral hepatitis is a significant contributor to the immunosenescent phenotype of parenteral drug addiction
Authors: Reece Albert S. 
Published: September 2008

ABSTRACTIntravenous drug addiction is known to be associated with an inordinate morbidity and mortality. As our previous report had identified an immune phenotype consistent with accelerated ageing, we wished to investigate how much of this change may have been related to chronic viral hepatitis. A total of 12 409 clinical pathology results from the period 1995–2007 were reviewed. To control for the differences in age, only patients less than 48 years of age were considered. A total of 636 substance use disorder (SUD) and 6103 non‐SUD (N‐SUD) patients were studied. They had comparable ages (mean ± SD 31.32 ± 6.90 versus 31.57 ± 9.23, P‐value not significant), but the SUD group had more males (74.37% versus 53.20%, P < 0.001). For most of the changes examined splitting the two SUD groups into hepatitis C positive (HCV+) and hepatitis C negative (HCV−) demonstrated that the majority of the described changes were most marked in the HCV+ group. The globulins were higher in the HCV+ group and the albumin was lower and fell more markedly with age than in N‐SUD or HCV− (all P < 0.001). The globulin/albumin ratio was significantly higher in HCV+ than HCV− or N‐SUD (both P < 0.0001) and rose more with age. These changes were paralleled by the ESR, elevations in the CRP and lymphocyte count. Transaminases were elevated in SUD and HCV+ groups compared with N‐SUD (all P < 0.02). At multivariate analysis ESR, lymphocyte count, dual hepatitis B and C seropositivity, AST and HCVAb were significant predictors of the serum globulin level and accounted for 21% of the variance. These data extend our earlier report and show that much of the immunosenescent phenotype of SUD, encompassing the known immunosuppression and the observed immunostimulation, is statistically related to chronic viral hepatitis. Important theoretical and practical management (vaccination) implications ensue.
REVIEW: Norepinephrine and stimulant addiction
Authors: Sofuoglu Mehmet , Sewell R. Andrew 
Published: September 2008

ABSTRACTNo pharmacotherapies are approved for stimulant use disorders, which are an important public health problem. Stimulants increase synaptic levels of the monoamines dopamine (DA), serotonin and norepinephrine (NE). Stimulant reward is attributable mostly to increased DA in the reward circuitry, although DA stimulation alone cannot explain the rewarding effects of stimulants. The noradrenergic system, which uses NE as the main chemical messenger, serves multiple brain functions including arousal, attention, mood, learning, memory and stress response. In pre‐clinical models of addiction, NE is critically involved in mediating stimulant effects including sensitization, drug discrimination and reinstatement of drug seeking. In clinical studies, adrenergic blockers have shown promise as treatments for cocaine abuse and dependence, especially in patients experiencing severe withdrawal symptoms. Disulfiram, which blocks NE synthesis, increased the number of cocaine‐negative urines in five randomized clinical trials. Lofexidine, an α2‐adrenergic agonist, reduces the craving induced by stress and drug cues in drug users. In addition, the NE transporter (NET) inhibitor atomoxetine attenuates some of d‐amphetamine's subjective and physiological effects in humans. These findings warrant further studies evaluating noradrenergic medications as treatments for stimulant addiction.
Prospective monitoring of BK virus replication in renal transplant recipients
Authors: Koukoulaki M. , Grispou E. , Pistolas D. , Balaska K. , Apostolou T. , Anagnostopoulou M. , Tseleni‐Kotsovili A. , Hadjiconstantinou V. , Paniara O. , Saroglou G. , Legakis N. , Drakopoulos S. 
Published: September 2008

Background. BK virus‐associated nephropathy (BKVAN) can be diagnosed only with renal graft biopsy. Definitive diagnosis of BKVAN requires demonstration of BK virus (BKV) replication in renal allograft tissues. Non‐invasive analysis of urine and blood is considered essential in screening renal transplant recipients.Patients and methods. This study evaluated prospectively the replication of BKV in plasma and urine with qualitative and quantitative real‐time polymerase chain reaction in 32 de novo (group A) and 34 chronic (group B) renal transplant recipients and the long‐term impact on graft function.Results. In group A, 456 samples (228 plasma, 228 urine) were examined and BKV was detected in 31 (31/228, 14%) samples of plasma and 57 (57/228, 25%) samples of urine in 20 (20/32, 62.5%) and 23 (23/32, 72%) recipients, respectively. Incidence of viremia and viruria increased during the first 6 months presenting a peak the third postoperative month (viremia: 28% and viruria: 31%). Immune suppressive treatment with tacrolimus showed significant relation with viremia. Renal graft function in de novo renal transplant recipients remained stable throughout the follow‐up period without influence of BKV replication. In group B, incidence of viremia and viruria were 3% (1/34) and 9% (3/34) correspondingly, indicating that after the first post‐transplant year the risk of BKV re‐activation is diminished.Conclusion. The highest incidence of BK viremia and viruria is observed the third post‐transplantation month, confirming previously published studies in Europe and the United States, and long‐term follow up shows that BKV replication decreases significantly after the third post‐transplant month and even transient viremia or viruria does not have an impact on renal function.
Divergence in parental care, habitat selection and larval life history between two species of Peruvian poison frogs: an experimental analysis
Authors: BROWN J. L. , MORALES V. , SUMMERS K. 
Published: September 2008

AbstractChanges in the nature of the ecological resources exploited by a species can lead to the evolution of novel suites of behaviours. We identified a case in which the transition from large pool use to the use of very small breeding pools in neotropical poison frogs (family Dendrobatidae) is associated with the evolution of a suite of behaviours, including biparental care (from uniparental care) and social monogamy (from promiscuity). We manipulated breeding pool size in order to demonstrate experimentally that breeding habitat selection strategy has evolved in concert with changes in parental care and mating system. We also manipulated intra‐ and interspecific larval interactions to demonstrate that larval adaptation to the use of very small pools for breeding affected the evolution of larval competition and cannibalism. Our results illustrate the intimate connection between breeding pool ecology, parental care and mating strategies in Peruvian poison frogs.
Evaluation of Drought‐Related Traits and Screening Methods at Different Developmental Stages in Spring Barley
Authors: Szira F. , Bálint A. F. , Börner A. , Galiba G. 
Published: September 2008

AbstractDespite intensive research and breeding efforts, the physiological and quantitative genetic bases of drought tolerance are still poorly understood. The comparison of results obtained from different sources is also complex, because different testing methods may lead to controversial conclusions. This report discusses various drought stress experiments (hydroponics and in soil) in which the plant tolerance was studied at different developmental stages. Tests were performed in the germination, seedling and adult plant stages on the parental lines of five well‐known barley‐mapping populations. The results suggest that drought tolerance is a stage‐specific trait and changes during the life cycle. The effect of drought stress depended not only on the duration and intensity of water deficiency, but also on the developmental phase in which it began. To induce the same type of stress and to obtain comparable tolerance information from the replications, it is recommended that drought stress should be induced at the same growth stage. Correlations between the traits, commonly associated with improved drought resistance (high relative water content under stress, proline accumulation, osmoregulation) with stress tolerance indexes, are also presented, while the advantages and disadvantages of the most frequently used screening methods are discussed.
Recovery and Cryopreservation of Epididymal Sperm of Plains Bison (Bison bison bison) as a Model for Salvaging the Genetics of Wood Bison (Bison bison athabascae)
Authors: Aurini LC , Whiteside DP , Elkin BT , Thundathil JC 
Published: September 2008

ContentsThe objective of this study was to optimize recovery and cryopreservation of epididymal sperm from plains bison, as a model for wood bison. In Phase 1, cauda epididymides were recovered from bison (n = 14) immediately after slaughter, minced and incubated in Sp‐TALPH buffer for 3 h at 36°C. The resulting sperm suspensions were cryopreserved in Triladyl®, using a protocol for bovine semen. In Phase 2, epididymal sperm were cryopreserved in either Triladyl® or Andromed®. The mean (±SD) estimated number of sperm recovered was 468 ± 207 × 106. There was an increase (p < 0.05) in the proportion of sperm with normal morphology between initial recovery and after extension (52.4 ± 4.6 vs 69.7 ± 2.4%), with a concurrent decrease (p < 0.05) in the proportion of sperm with distal droplets. Median values for progressively motile sperm in post‐thaw samples (60%) were lower (p < 0.05) than that after extension or after chilling (70% for both). The mean percentages of viable sperm and of sperm with an intact acrosome were lower (p < 0.05) for frozen‐thawed samples (38.7 ± 2.8 and 85.2 ± 1.1) compared with extended (66.2 ± 2.2 and 92.4 ± 0.9) or chilled (63.7 ± 2.5 and 90.0 ± 1.0) samples. Rates of cleavage, morulae and blastocyst production were not significantly different for chilled (70.9, 38.7 and 8.0%) vs post‐thaw sperm (73.0, 46.0 and 6.3%). There was no significant difference between extenders for most sperm characteristics. In conclusion, we developed a functional protocol for the recovery and cryopreservation of epididymal sperm from plains bison, which may have implications for the genetic preservation of wood bison.
Shorter break‐in period is a viable option with tighter PD catheter securing during the insertion
Authors: SHARMA AJAY P , MANDHANI ANIL , DANIEL SHAJI P , FILLER GUIDO 
Published: September 2008

SUMMARY:Background:  Recent single‐arm studies reported good catheter outcome despite shorter break‐in periods after peritoneal dialysis (PD) catheter insertions. These results were attributed to tight catheter securing during the insertions.Objective:  To compare catheter‐related outcomes after different break‐in periods in the tightly secured PD catheters.Patients and Methods:  The study cohort comprised 48 patients, who underwent catheter insertions with the modified insertion technique. Based on the duration of break‐in period, the patients were grouped into a shorter break‐in period arm, with break‐in period of 7 days or less and a standard break‐in period arm, with break‐in period of about 2 weeks. Mean patient follow up was 9.68 ± 4.35 months, with a similar follow‐up duration between the two break‐in period arms (P = 0.94).Results:  In the study cohort, the incidence of pericatheter leaks, pericatheter haemorrhage, catheter malfunction and peritonitis was 2/48 (4%), 1/48 (2%), 1/48 (2%) and 3/48 (6%), respectively. There was no other‐site leak, bowel perforation, hernia formation or wound dehiscence. Of these complications, two pericatheter leaks, one catheter malfunction and three peritonitis episodes followed standard break‐in periods, whereas, one pericatheter haemorrhage occurred in the shorter break‐in period arm.Conclusion:  After a tight catheter securing during the insertions, overall pericatheter leak incidence remained low in the whole study cohort, and it did not worsen despite a shorter break‐in period. Future studies with larger patient numbers are needed to validate the role of shorter break‐in period in PD practice.