bluuebunny/crossref_metadata_2025_split huggingface dataset:
Factors Affecting the Folding of Pseudomonas aeruginosa OprF Porin into the One-Domain Open Conformer
Authors: Sugawara Etsuko , Nagano Keiji , Nikaido Hiroshi 
Published: October 2010

ABSTRACT

Pseudomonas aeruginosa
OprF is a largely monomeric outer membrane protein that allows the slow, nonspecific transmembrane diffusion of solutes. This protein folds into two different conformers, with the majority conformer folding into a two-domain conformation that has no porin activity and the minority conformer into a one-domain conformation with high porin activity and presumably consisting of a large β barrel. We examined the factors that control the divergent folding pathways of OprF. OprF contains four Cys residues in the linker region connecting the N-terminal β-barrel domain and the C-terminal globular domain in the majority conformer. Prevention of disulfide bond formation either by expression of OprF in an
Escherichia coli
dsbA
strain grown with dithiothreitol or by replacement of all Cys residues with serine (CS OprF) increased the specific pore-forming activity of OprF significantly. Replacement of Phe160 with Ile at the end of the β-barrel termination signal as well as replacement of Lys164 in the linker region with Gly, Cys, or Glu increased porin activity 2-fold. Improving a potential β-barrel termination signal in the periplasmic domain by replacement of Asp211 with asparagine also increased porin activity. The porin activity could be improved about 5-fold by the combination of these replacements. OprF mutants with higher porin activity were shown to contain more one-domain conformers by surface labeling of the A312C residue in intact cells, as this residue is located in the periplasmic domain in the two-domain conformers. Finally, when the OprF protein was expressed in an
E. coli
strain lacking the periplasmic chaperone Skp, the CS OprF protein exhibited increased pore-forming activity.

IMPORTANCE
High intrinsic levels of resistance to many antimicrobial agents, seen in Gram-negative bacterial species such as
Pseudomonas aeruginosa
and
Acinetobacter
species, are largely due to the extremely low permeability of their major porin OprF and OmpA. Because this low permeability is caused by the fact that these proteins mostly fold into a two-domain conformer without pores, knowledge as to what conditions increase the production of the pore-forming minority conformer may lead to dramatic improvements in the treatment of infections by these bacteria. We have found several factors that increase the proportion of the pore-forming conformer up to 5-fold. Although these studies were done with
Escherichia coli
, they may serve as the starting point for the design of strategies for improvement of antimicrobial therapy for these difficult-to-treat pathogens, some strains of which have now attained the “pan-resistant” status.
Effect of Acupuncture on Assisted Reproduction Treatment Outcomes
Authors: Madaschi Camila , Braga Daniela Paes Almeida Ferreira , Figueira Rita de Cássia Savio , Iaconelli Assumpto , Borges Edson 
Published: October 2010

Background Acupuncture has recently been used as a complementary technique in the management of infertility. It has physiological and psychological effects and may be considered an alternative for stress reduction in women undergoing infertility treatments. Objective To examine the hypothesis that acupuncture treatment may increase the pregnancy rate in patients undergoing intracytoplasmic sperm injection cycles. Methods Patients enrolled in the study were stratified according to age and randomised to either a control group (n=208) or acupuncture group, (n=208). The pregnancy, implantation and abortion rates of the two groups were compared. Results No influence of acupuncture treatment on clinical outcomes was seen; however, when cycles in which the causes of infertility were exclusively tubal-uterine or idiopathic were evaluated separately, a positive influence of acupuncture on pregnancy (OR=5.15, 95% CI 1.03 to 34.5; p=0.048) was noted. Moreover, trends toward an increase in implantation were seen when acupuncture was performed (regression coefficient: 0.645; p=0.092). Conclusion The results suggest that acupuncture treatment had no influence when performed immediately before and immediately after embryo transfer, on clinical outcomes overall. In a subgroup analysis, when the embryo was not affected by an ovarian or seminal influence, a benefit was noted.
Insulin overdose
Authors: Fawcett Anne 
Published: October 2010

THIS series gives readers the opportunity to consider and contribute to discussion of some of the ethical dilemmas that can arise in veterinary practice. Each month, a case scenario is presented, followed by discussion of some of the issues involved. In addition, a possible way forward is suggested; however, there is rarely a cut‐anddried answer in such cases, and readers may wish to suggest an alternative approach. This month's dilemma, ‘Insulin overdose’, is presented and discussed by Anne Fawcett. Readers with comments to contribute are invited to send them as soon as possible, so that they can be considered for publication in the next issue. Discussion of the dilemma ‘The wrong vaccine’, which was published in the May issue of In Practice, appears on page 271.The series is being coordinated by Siobhan Mullan, of the University of Bristol. It is hoped it will provide a framework that will help practices find solutions when facing similar dilemmas.
Postoperative responsibility
Authors: Main Clare 
Published: October 2010

THIS series gives readers the opportunity to consider and contribute to discussion of some of the ethical dilemmas that can arise in veterinary practice. Each month, a case scenario is presented, followed by discussion of some of the issues involved. In addition, a possible way forward is suggested; however, there is rarely a cut‐anddried answer in such cases, and readers may wish to suggest an alternative approach. This month's dilemma, ‘Postoperative responsibility’, was submitted by a reader and is presented and discussed by Clare Main. Readers with comments to contribute are invited to send them as soon as possible, so that they can be considered for publication in the next issue. Discussion of the dilemma ‘Canine blood donor’, which was published in the November/December 2009 issue of In Practice, appears on page 39.The series is being coordinated by Siobhan Mullan, of the University of Bristol. It is hoped it will provide a framework that will help practices find solutions when facing similar dilemmas.
Mechanisms of magnesium amelioration of aluminum toxicity in soybean at the gene expression level
Authors: Duressa Dechassa , Soliman Khairy M. , Chen Dongquan 
Published: October 2010

Micromolar concentration of magnesium (Mg) in culture solution is known to ameliorate aluminum (Al) toxicity in soybean and other leguminous species. To advance the understanding of this phenomenon at the level of gene expression in soybean, we undertook a comparative transcriptome analysis using DNA microarrays and Al-tolerant and Al-sensitive genotypes treated with Al ions alone or Al plus Mg ions. We observed a more rapid alteration of transcription for Al-tolerant than Al-sensitive soybean after introduction of Mg into Al-containing medium, but at 72 h, far more genes were altered (both upregulated and downregulated) in the Al-sensitive line, reflecting the known greater saving effect of Mg for Al-sensitive than Al-tolerant lines. Mg appears to ameliorate Al toxicity in the sensitive genotype by the dual mechanisms of (i) specifically increasing the expression level of several genes that are upregulated in the Al-treated, Al-tolerant genotype in the absence of Mg and (ii) possibly saving energy by decreasing expression of most genes relative to expression under Al stress. Mg-mediated reduction in gene expression also appears to be an important mechanism of Mg protection of the Al-tolerant genotype.
Segregation distortion and linkage analysis in eggplant (Solanum melongenaL.)
Authors: Barchi Lorenzo , Lanteri Sergio , Portis Ezio , Stàgel Anikò , Valè Giampiero , Toppino Laura , Rotino Giuseppe Leonardo 
Published: October 2010

An anther-derived doubled haploid (DH) population and an F2mapping population were developed from an intraspecific hybrid between the eggplant breeding lines 305E40 and 67/3. The former incorporates an introgressed segment from Solanum aethiopicum Gilo Group carrying the gene Rfo-sa1, which confers resistance to Fusarium oxysporum ; the latter is a selection from an intraspecific cross involving two conventional eggplant varieties and lacks Rfo-sa1. Initially, 28 AFLP primer combinations (PCs) were applied to a sample of 93 F2individuals and 93 DH individuals, from which 170 polymorphic AFLP fragments were identified. In the DH population, the segregation of 117 of these AFLPs as well as markers closely linked to Rfo-sa1 was substantially distorted, while in the F2population, segregation distortion was restricted to just 10 markers, and thus the latter was chosen for map development. A set of 141 F2individuals was genotyped with 73 AFLP PCs (generating 406 informative markers), 32 SSRs, 4 tomato RFLPs, and 3 CAPS markers linked to Rfo-sa1. This resulted in the assignment of 348 markers to 12 major linkage groups. The framework map covered 718.7 cM, comprising 238 markers (212 AFLPs, 22 SSRs, 1 RFLP, and the Rfo-sa1 CAPS). Marker order and inter-marker distances in this eggplant map were largely consistent with those reported in a recently published SSR-based map. From an eggplant breeding perspective, DH populations produced by anther culture appear to be subject to massive segregation distortion and thus may not be very efficient in capturing the full range of genetic variation present in the parental lines.
Metabolic responses of upper-body accelerometer-controlled video games in adults
Authors: Stroud Leah C. , Amonette William E. , Dupler Terry L. 
Published: October 2010

Historically, video games required little physical exertion, but new systems utilize handheld accelerometers that require upper-body movement. It is not fully understood if the metabolic workload while playing these games is sufficient to replace routine physical activity. The purpose of this study was to quantify metabolic workloads and estimate caloric expenditure while playing upper-body accelerometer-controlled and classic seated video games. Nineteen adults completed a peak oxygen consumption treadmill test followed by an experimental session where exercising metabolism and ventilation were measured while playing 3 video games: control (CON), low activity (LOW) and high activity (HI). Resting metabolic measures (REST) were also acquired. Caloric expenditure was estimated using the Weir equation. Mean oxygen consumption normalized to body weight for HI condition was greater than LOW, CON, and REST. Mean oxygen consumption normalized to body weight for LOW condition was also greater than CON and REST. Mean exercise intensities of oxygen consumption reserve for HI, LOW, and CON were 25.8% ± 5.1%, 6.4% ± 4.8%, and 0.8% ± 2.4%, respectively. Estimated caloric expenditure during the HI was significantly related to aerobic fitness, but not during other conditions. An active video game significantly elevated oxygen consumption and heart rate, but the increase was dependent on the type of game. The mean oxygen consumption reserve during the HI video game was below recommended international standards for moderate and vigorous activity. Although upper-body accelerometer-controlled video games provided a greater exercising stimulus than classic seated video games, these data suggest they should not replace routine moderate or vigorous exercise.
Aerobic activity before and following short-duration static stretching improves range of motion and performance vs. a traditional warm-up
Authors: Murphy Justin R. , Di Santo Mario C. , Alkanani Thamir , Behm David G. 
Published: October 2010

Many activities necessitate a high degree of static joint range of motion (ROM) for an extended duration. The objective of this study was to examine whether ROM could be improved with a short duration and volume of static stretching within a warm-up, without negatively impacting performance. Ten male recreationally active participants completed 2 separate protocols to examine changes in ROM and performance, respectively, with different warm-ups. The warm-up conditions for the ROM protocol were static stretching (SS), consisting of 6 repetitions of 6 s stretches; 10 min of running prior to the SS (AS); and 5 min of running before and after the SS (ASA). The performance protocol included a control condition of 10 min of running. Measures for the ROM protocol included hip flexion ROM, passive leg extensor tension, and hamstring electromyographic (EMG) activity at pre-warm-up, and at 1, 10, 20, and 30 min post-warm-up. Performance measures included countermovement jump (CMJ) height, reaction time (RT), movement time (MT), and balance at pre-warm-up and at 1 and 10 min post-warm-up. The ASA produced greater ROM overall than the SS and AS conditions (p < 0.0001), persisting for 30 min. There were no significant alterations in passive muscle tension or EMG. For the performance protocol, there were no main effects for condition, but there was a main effect for time, with CMJ height being greater at 1 and 10 min post-warm-up (p = 0.0004). Balance ratios and MT improved at 10 min post-warm-up (p < 0.0001). Results indicate that the ASA method can provide ROM improvements for 30 min with either facilitation or no impairment in performance. This may be especially important for athletes who substitute later into a game with minimal time for a full warm-up.
A decreasedn-6/n-3 ratio in the fat-1 mouse is associated with improved glucose tolerance
Authors: Smith Brennan K. , Holloway Graham P. , Reza-Lopez Sandra , Jeram Stanley M. , Kang Jing X. , Ma David W.L. 
Published: October 2010

A reduction in skeletal muscle fatty acid oxidation (FAO), manifested as a reduction in mitochondrial content and (or) FAO within mitochondria, may contribute to the development of insulin resistance. n-3 polyunsaturated fatty acids (PUFA) have been observed to increase the capacity for FAO and improve insulin sensitivity. We used the fat-1 mouse model, a transgenic animal capable of synthesizing n-3 PUFA from n-6 PUFA, to examine this relationship. Fat-1 mice exhibited a ~20-fold decrease in the n-6/n-3 ratio in skeletal muscle, and plasma glucose and the area under the glucose curve were significantly (p < 0.05) lower in fat-1 mice during a glucose challenge test. The improvement in whole-body glucose tolerance in the fat-1 mouse was associated with a ~21% (p < 0.05) decrease in whole-muscle citrate synthase (CS) activity (in red muscle only), without alterations in CS activity of isolated mitochondria (either red or white muscle; p > 0.05). These data suggest that the fat-1 mouse has decreased skeletal muscle mitochondrial content. However, the intrinsic ability of mitochondria to oxidize fatty acids was not altered in the fat-1 mouse, as rates of palmitate oxidation in isolated mitochondria from both red and white muscle were unchanged. Overall, this study demonstrates that a decrease in the n-6/n-3 ratio can enhance glucose tolerance in healthy animals, independent of changes in mitochondrial content.
Effect of culture age, protectants, and initial cell concentration on viability of freeze-dried cells ofMetschnikowia pulcherrima
Authors: Spadaro Davide , Ciavorella Annalisa Alessandra , Lopez-Reyes Jorge Giovanny , Garibaldi Angelo , Gullino Maria Lodovica 
Published: October 2010

The effect of freeze-drying using different lyoprotectants at different concentrations on the viability and biocontrol efficacy of Metschnikowia pulcherrima was evaluated. The effects of initial yeast cell concentration and culture age on viability were also considered. Yeast cells grown for 36 h were more resistant to freeze-drying than were 48 h cells. An initial concentration of 108cells·mL–1favoured the highest survival after freeze-drying. When maltose (25%, m/v) was used as protectant, a high cell viability was obtained (64.2%). Cells maintained a high viability after 6 months of storage at 4 °C. The biocontrol efficacy of freeze-dried cells was similar to the activity of fresh cells on ‘Gala’ apples and was slightly lower on ‘Golden Delicious’ apples. After optimizing freeze-drying conditions, the viability of M. pulcherrima cells was similar to that obtained in other studies. The results constitute a first step towards the commercial development of M. pulcherrima as a biocontrol agent.
Reversal of isoprenaline-induced cardiac remodeling by rutaecarpine via stimulation of calcitonin gene-related peptide production
Authors: Li Jian-Zhe , Peng Jun , Xiao Li , Zhang Yi-Shuai , Liao Mei-Chun , Li Xiao-Hui , Hu Chang-Ping , Deng Han-Wu , Li Yuan-Jian 
Published: October 2010

Dysfunction of capsaicin-sensitive sensory nerves is involved in cardiac remodeling, and rutaecarpine has been shown to exert a beneficial effect on cardiac function through activating the sensory nerves. This study was conducted to explore the potential inhibitory effect of rutaecarpine on cardiac remodeling and the underlying mechanisms. A rat cardiac remodeling model was established by injection of isoprenaline (5 mg/kg per day, s.c.) for 10 days. Rutaecarpine (10 or 40 mg/kg, i.g.) was coadministrated with isoprenaline to evaluate the effect of rutaecarpine on cardiac remodeling. After echocardiographic analysis was performed, blood samples were collected to quantify calcitonin gene-related peptide (CGRP), dorsal root ganglia were isolated for examining CGRP mRNA expression, and the hearts were weighed and saved for evaluating the parameters related to apoptosis and hypertrophy. Isoprenaline significantly increased the ratio of left ventricle weight to body weight, the cross-sectional area of cardiomyocytes, cardiac apoptosis, and collagen deposition concomitantly with decreased CGRP production, which were reversed by rutaecarpine treatment. The beneficial effects of rutaecarpine were attenuated by pretreatment with capsaicin, which selectively depleted CGRP. These results suggest that rutaecarpine was able to reverse isoprenaline-induced cardiac remodeling through stimulating CGRP production.
Retinol-deficient rats can convert a pharmacological dose of astaxanthin to retinol: antioxidant potential of astaxanthin, lutein, and β-carotene
Authors: Sangeetha R. K. , Baskaran V. 
Published: October 2010

Retinol (ROH) and provitamin-A carotenoids are recommended to treat ROH deficiency. Xanthophyll carotenoids, being potent antioxidants, can modulate health disorders. We hypothesize that nonprovitamin-A carotenoids may yield ROH and suppress lipid peroxidation under ROH deficiency. This study aimed to (i) study the possible bioconversion of astaxanthin and lutein to ROH similar to β-carotene and (ii) determine the antioxidant potential of these carotenoids with reference to Na+/K+-ATPase, antioxidant molecules, and lipid peroxidation (Lpx) induced by ROH deficiency in rats. ROH deficiency was induced in rats (n = 5 per group) by feeding a diet devoid of ROH. Retinol-deficient (RD) rats were gavaged with astaxanthin, lutein, β-carotene, or peanut oil alone (RD group) for 7 days. Results show that the RD group had lowered plasma ROH levels (0.3 µmol/L), whereas ROH rose in astaxanthin and β-carotene groups (4.9 and 5.7 µmol/L, respectively), which was supported by enhanced (69% and 70%) intestinal β-carotene 15,15′-monooxygenase activity. Astaxanthin, lutein, and β-carotene lowered Lpx by 45%, 41%, and 40% (plasma), respectively, and 59%, 64%, and 60% (liver), respectively, compared with the RD group. Lowered Na+/K+-ATPase and enhanced superoxide dismutase, catalase, and glutathione-S-transferase activities support the lowered Lpx. To conclude, this report confirms that astaxanthin is converted into β-carotene and ROH in ROH-deficient rats, and the antioxidant potential of carotenoids was in the order astaxanthin > lutein > β-carotene.
Restricted feeding improves postischemic recovery of Langendorff-perfused rat hearts
Authors: Jaitovich María M. , Varela Alicia , Sbarbati Cintia , Hermann Romina , Torresín María E. , Savino Enrique A. , Marina Prendes María G. 
Published: October 2010

The goal of the present study was to assess the effects of a restricted feeding schedule (RFS) on postischemic contractile recovery in relation to triacylglycerol (TAG), glycogen, and ATP content. Glucose-6-phosphate dehydrogenase (G6PDH) activity, reduced/oxidized glutathione ratio (GSH/GSSG), and thiobarbituric acid reactive substances (TBARS) levels were also determined. Isolated rat hearts entrained to daily RFS (2 h food access starting at 1200) or fed ad libitum (FED) for 3 weeks were Langendorff-perfused (25 min ischemia, 30 min reperfusion) with Krebs–Ringer bicarbonate solution (10 mmol/L glucose). RFS improved the recovery of contractility and reduced creatine kinase (CK) release upon reperfusion. Further, at the end of reperfusion, RFS hearts exhibited increased G6PDH activity and repletion of tissue glycogen, TAG, and ATP that was not observed in the FED hearts. GSH/GSSG at the end of reperfusion fell to the same value in both nutritional states, and TBARS levels were higher in the RFS hearts. In conclusion, RFS improved postischemic functional recovery, which was accompanied by a reduction in CK release and a striking energy recovery. Although enhanced G6PDH activity was displayed, RFS was unable to reduce lipid peroxidation, supporting a clear dissociation between protection against mechanical dysfunction and CK release on the one hand and oxidative damage on the other.
The acute administration of either amiloride or captopril does not prevent endothelial dysfunction induced by ischemia and reperfusion in the human forearm vasculature
Authors: Luca Mary Clare , Liuni Andrew , DiFabio Jonathan , Gori Tommaso , Parker John D. 
Published: October 2010

Animal studies have demonstrated the ability of both sodium–hydrogen exchange inhibitors and angiotensin-converting enzyme inhibitors to reduce infarct size and preserve postischemic ventricular function following ischemia and reperfusion (IR) injury. Whether these interventions can also prevent IR-induced impairment of endothelial function in humans has not been investigated. We performed 2 separate double-blind, placebo-controlled, crossover studies. In the first study, 10 healthy volunteers were randomized to receive oral amiloride (10 mg) or a placebo. In a separate study, another group of volunteers (n = 10) was randomized to receive oral captopril (50 mg) or a placebo. At the time of the peak hemodynamic effect of the drug (3 and 1.5 h after administration of amiloride and captopril, respectively), endothelium-dependent, flow-mediated dilatation of the radial artery was measured before and after IR. IR significantly blunted flow-mediated dilatation in all groups (placebo: pre-IR: 6.8% ± 0.7%; post-IR: 2.9% ± 0.9%; P < 0.01; amiloride: pre-IR: 5.9% ± 0.6%; post-IR: 2.1% ± 1.3%; P = 0.01; captopril: pre-IR: 6.0% ± 0.5%; post-IR: 2.0% ± 0.6%; P < 0.01). In humans, neither 10 mg of oral amiloride nor 50 mg of oral captopril was able to provide protection against IR-induced endothelial dysfunction in the peripheral vasculature.