bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatty acid profile of Escherichia coli during the heat‐shock response
Authors: Mejía Ricardo , Gómez‐Eichelmann M. Carmen , Fernández Marta S. 
Published: July 2007

AbstractThe possible changes in the fatty acid profile of Escherichia coli during heat‐shock have been investigated. Bacteria growing in steady‐state at 30°C were subjected to an abrupt temperature upshift to 45°C and held at the high temperature for various periods of time in order to elicit the heat‐shock response. Fatty acid compositions of lipids extracted from samples taken at different times after the temperature upshift, as well as from cultures in steady‐state at 30 and 45°C, were determined by gas‐chromatography. It has been found that the total unsaturates to total saturates ratio decreases gradually during heat‐shock and that 30 min after the temperature jump, the reduction is equivalent to 57% of the difference between ratios corresponding to steady‐state cultures at 30 and 45°C. Consistent with this remodeling of lipid acyl chains, there is a decrease in the excimerization rate of the fluidity probe dipyrenylpropane incorporated into sonicated E. coli lipid extracts. Such modifications occur within the time‐span of the heat‐shock response, as judged from our previous measurements of the kinetics of change in heat‐shock proteins induction ratio. Together, these results indicate that the control of membrane fluidity during the heat‐shock response can be accounted for, at least in part, by an important change in the fatty acid composition of Escherichia coli lipids.
Suppression of Caspase‐3 and Nitric‐Oxide Synthase‐2 During Buccal Mucosal Ulcer Healing: Effect of Chronic Alcohol Ingestion
Authors: Slomiany B. L. , Piotrowski J. , Slomiany A. 
Published: July 2007

AbstractIn this study, we analyzed the effect of chronic alcohol ingestion on the expression of constitutive (cNOS) and inducible (NOS2) nitric‐oxide synthase and the activity of an apoptotic protease, caspase‐3, during buccal mucosal ulcer healing in rats maintained for 5 weeks on alcohol‐containing or control liquid diet. In comparison with the controls, the ulcer onset in the alcohol group was characterized by a 2.5‐fold greater epithelial cells apoptosis, 2.1‐fold greater expression of caspase‐3 activity, and a 1.4‐fold greater enhancement in NOS‐2, but expression of cNOS showed a 1.3‐fold decrease. In both groups the ulcer healing was accompanied by a gradual decline in apoptosis, caspase‐3, and NOS‐2 and a recovery in cNOS activity, but the changes were considerably slower in the alcohol diet group, as manifested by a 40%(4 days) delay in ulcer healing. These results suggest that chronic alcohol ingestion interferes with the suppression of NOS‐2 and the apoptotic events propagated by caspase‐3 and hence affects the efficiency of oral mucosal repair process.
From the President
Authors: Whelan William J. 
Published: July 2007

AbstractIn the growth of a flourishing science there comes a time when effective collaboration at an international level becomes essential, both for the exchange of knowledge and for the rapid advancement of the subject. By the summer of 1949 when the First International Congress of Biochemistry was held in Cambridge (UK) it was clear to many of those taking part that this time had now arrived and an International Committee of Biochemistry was accordingly set up under the Chairmanship of Sir Charles Harington. The objectives of this Committee were not only to arrange for a continuing series of International Congresses of Biochemistry but also to establish an International Union of Biochemistry (IUB) and in due course to approach the International Council of Scientific Unions (ICSU) in order to obtain their recognition of this proposed new Union.
Induction of Neutrophil Calcium Mobilization by Phosphatidic Acid‐Enriched Plasma Membranes
Authors: Bentz Melissa , Harvey Kevin , Burtschi Daniel J. , English Denis , Siddiqui Rafat A. 
Published: July 2007

AbstractThe purpose of this investigation was to determine if phosphatidic acid (PA) confined to biological membranes could induce physiological responses similar to those induced by exogenous PA. Plasma membranes were treated with phospholipase D (PLD) to increase concentrations of PA within the membranes. Membranes were also treated with other phospholipases including phospholipase A2 (PLA2), and phospholipase C (PLC), which degrade phospholipids without generating PA. A phosphatidylinositol (PI) 3‐ kinase inhibitor, LY294002, strongly and selectively inhibited intracellular calcium mobilization induced by PLD‐treated membranes. This study suggests that PA‐enriched plasma membranes, which exert their effects by activating a unique signaling pathway mediated by PI 3‐kinase, are potent, physiologically relevant initiators of neutrophil activation.
Effects of Chlorophyll Availability on Phycobilisomes in Synechocystis sp. PCC 6803
Authors: Yu Jiujiu , Wu Qingyu , Mao Haibin , Zhao Nanming , Vermaas Wim F. J. 
Published: July 2007

AbstractInactivation of the chlL gene in Synechocystis sp. PCC 6803 resulted in negligible chlorophyll content when the mutant was grown in darkness. Upon phycocyanin excitation at 580 nm, the 77K fluorescence spectrum of dark‐grown cells showed three peaks at 648 nm, 665 nm, and 685 nm, this last being the largest. This reflects the functional presence of major components of phycobilisomes, including phycocyanin, allophycocyanin, and the terminal emitter, and efficient energy transfer between these components. As expected, no fluorescence emission peaks corresponding to chlorophyll in the photosystems were observed. Intact phycobilisomes could be isolated from the dark‐grown chlL‐deletion mutant. However, the phycobilisomes had a lower efficiency of energy transfer than did those isolated from the light‐grown mutant, probably because of a decreased phycobilisome stability in the absence of chlorophyll. Exposing the dark‐grown chlL‐deletion mutant to light triggered the biosynthesis of chlorophyll. For the first 6h in the light, upon phycocyanin excitation at 580 nm, the 77K fluorescence emission spectrum of greening cells was identical to that of dark‐grown cells that lacked significant amounts of chlorophyll. With increased chlorophyll synthesis, gradual energy transfer from phycobilisomes to the two photosystems can be demonstrated.
Expression of Murine Poly(A) Binding Protein II Gene in Testis
Authors: Lee Young Jae , Ahn Jeong Keun , Chung Jae Hoon 
Published: July 2007

AbstractThe poly(A) binding protein II gene (PAB II) has been highly conserved among mouse, bovine, and human. The promoter region of the murine PAB II gene (mPAB II) was investigated in this study. Primer extension analysis demonstrated that there are multiple sites for starting transcription. The promoter region of mPAB II gene contains a CpG island but lacks a TATA box, suggesting that the mPAB II mRNA is transcribed by a TATA‐less promoter. Two transcription factor binding sites flanking the major transcription start site were confirmed by gel shift assay. The transcription level of the mPAB II gene in testis increases during spermatogenesis, and mPAB II protein accumulates densely in the nuclei of spermatocytes and round spermatids.
Osteopontin Is Induced by Nitric Oxide in RAW 264.7 Cells
Authors: Takahashi Fumiyuki , Takahashi Kazuhisa , Maeda Kayo , Tominaga Shigeru , Fukuchi Yoshinosuke 
Published: July 2007

AbstractNitric oxide (NO) produced by macrophages is thought to contribute to various pathological conditions. Osteopontin (OPN) is a phosphorylated glycoprotein produced principally by macrophages. OPN inhibits inducible nitric oxide synthase (iNOS), which generates large amounts of NO production. However, the relationship between NO and endogenous OPN in activated macrophages has not yet been elucidated. We therefore examined expression of endogenous iNOS and OPN in a murine macrophage cell line, RAW 264.7 cells, by treating the cells with lipopolysaccharide (LPS) and interferon‐gamma (IFN‐gamma). Treatment of cells with LPS and IFN‐gamma resulted in an increase of iNOS mRNA to maximum at 12h after stimulation. In contrast, OPN mRNA was induced more slowly than iNOS mRNA. Induction of both iNOS and OPN mRNA in RAW 264.7 cells was markedly suppressed by addition of the specific iNOS inhibitor S‐2‐aminoethyl isothiourea dihydrobromide. The NOS inhibitor NG‐methyl‐L‐arginine also suppressed induction of OPN mRNA but hardly affected iNOS mRNA expression. The NO‐releasing agent spermine‐NONOate but not peroxynitrite enhanced induction of OPN mRNA. These results suggest that NO directly up‐regulates the endogenous OPN in macrophages stimulated with LPS and IFN‐gamma. This up‐regulation of endogenous OPN may represent a negative feedback system acting to reduce iNOS expression.
Sphingosine 1‐Phosphate Activates Erk‐1/‐2 by Transactivating Epidermal Growth Factor Receptor in Rat‐2 Cells
Authors: Kim Joo‐Hee , Kim Jung‐Hee , Song Woo Keun , Kim Jae‐Hong , Chun Jang‐Soo 
Published: July 2007

AbstractWe investigated a signaling pathway leading to activation of extracellular signal‐regulated protein kinase (Erk) 1 and 2 in Rat‐2 cells stimulated with sphingosine 1‐phosphate (S1P). S1P treatment transiently activated Erk‐1/‐2 in a dose‐dependent manner, and its activation was blocked by pertussis toxin, expression of RasN17, or inhibition of Raf or MEK‐1/‐2. S1P‐induced activation of Erk‐1/‐2 was also suppressed by the inhibition of epidermal growth factor (EGF) receptor tyrosine kinase with the specific inhibitor AG1478, suggesting that activation of EGF receptor tyrosine kinase was involved in the signaling pathway. S1P‐induced Erk‐1/‐2 activation was enhanced up to 2‐fold by inhibiting protein kinase C (PKC) with GF109203X, and PKC inhibition in the absence of S1P treatment also activated Erk‐1/‐2. The stimulatory effects of Erk‐1/‐2 activation by PKC inhibition was blocked by treating cells with AG1478, suggesting the involvement of PKC in the regulation of EGF receptor tyrosine kinase activation that leads to Erk‐1/‐2 activation. Together, these results suggest that S1P activates the EGF receptor through a PKC‐dependent pathway that links Ras signaling to the activation of Erk‐1/‐2 in Rat‐2 cells.
4‐Hydroxynonenal in the Pathomechanisms of Oxidative Stress
Authors: Poli Giuseppe , Schaur Jörg R. 
Published: July 2007

AbstractHere we review the current knowledge on the biochemistry and molecular pathology of oxidative stress with specific regard to a major aldehydic end‐product stemming from peroxidation of biomembranes, that is 4‐hydroxynonenal (HNE). This multifunctional molecule, which derives from the most represented class of polyunsaturated fatty acids in the membranes, is potentially able to undergo a number of reactions with proteins, phospholipids, and nucleic acids. Despite an active metabolism in most of the cell types, HNE can be detected in several biological tissues by means of sufficiently precise methods, although with different sensitivity. In particular, relatively high steady‐state levels of HNE are often detectable in a large variety of human disease processes, pointing to some involvement of the aldehyde in their pathogenesis. Among the prominent pathobiochemical effects of HNE is its remarkable stimulation of fibrogenesis and inflammation, which indicates a potential contribution of the aldehyde to the pathogenesis of several chronic diseases, whose progression is indeed supported by inflammatory reactions and characterized by fibrosis. Further, of interest appears to be the ability of HNE to modulate cell proliferation through interference with the activity of cyclins and protein kinases and with the apoptotic machinery. Finally, on the basis of the already achieved evidence, pursuing investigation of the role of HNE in signal transduction and gene expression seems very promising.
Living with a Killer: The Effects of Hypochlorous Acid on Mammalian Cells
Authors: Pullar Juliet M. , Vissers Margret C. M. , Winterbourn Christine C. 
Published: July 2007

AbstractThe production of hypochlorous acid (HOCl) by the myeloperoxidase‐H2O2‐Cl system of phagocytes plays a vital role in the ability of these cells to kill a wide range of pathogens. However, the generation of a potent oxidant is not without risk to the host, and there is evidence that HOCl contributes to the tissue injury associated with inflammation. In this review, we discuss the biological reactivity of HOCl, and detail what is known of how it interacts with mammalian cells. The outcome of exposure is dependent on the dose of oxidant, with higher doses causing necrosis, and apoptosis or growth arrest occurring with lower amounts. Glutathione (GSH) and protein thiols are easily oxidized, and are preferred targets with low, sublethal amounts of HOCl. Thiol enzymes vary in their sensitivity to HOCl, with glyceraldehyde‐3‐phosphate dehydrogenase being most susceptible. Indeed, loss of activity occurred before GSH oxidation. The products of these reactions and the ability of cells to regenerate oxidized thiols are discussed. Recent reports have indicated that HOCl can activate cell signaling pathways, and these studies may provide important information on the role of this oxidant in inflammation.
Aberrant Caveolin‐1 Expression in Psoriasis: A Signalling Hypothesis
Authors: Campbell Lee , Gumbleton Mark 
Published: July 2007

AbstractA preliminary retrospective immunocytochemical study was conducted examining the expression of caveolin‐1 in skin biopsies resected from clinically defined psoriatic subjects. These pilot investigations revealed a dramatic down‐regulation of caveolin‐1 (a protein product of the caveolin supergene family known to regulate signal transduction events and cell cycle dynamics) in the hyperproliferative basal regions of the epidermis in all psoriatic biopsies examined when compared to normal control samples. These results lead us to hypothesise that caveolin‐1 negatively regulates key signal transduction pathways in epidermal keratinocytes and through it's reduced expression in psoriasis, pertubations in keratinocyte cell signalling and abnormal cell differentiation ensue, events fundamental to the development of the psoriatic phenotype. Novel therapeutic strategies for the treatment of psoriasis based upon caveolin‐1 protein can be envisaged.
Optimal location of centre of gravity for swashplateless helicopter UAV and MAV
Authors: Ganguli Ranjan , Jehnert Beatrix , Wolfram Jens , Voersmann Peter 
Published: July 2007

PurposeTo investigate the use of centre of gravity location on reducing cyclic pitch control for helicopter UAV's (unmanned air vehicles) and MAV's (micro air vehicles). Low cyclic pitch is a necessity to implement the swashplateless rotor concept using trailing edge flaps or active twist using current generation low authority piezoceramic actuators.Design/methodology/approachAn aeroelastic analysis of the helicopter rotor with elastic blades is used to perform parametric and sensitivity studies of the effects of longitudinal and lateral center of gravity (cg) movements on the main rotor cyclic pitch. An optimization approach is then used to find cg locations which reduce the cyclic pitch at a given forward speed.FindingsIt is found that the longitudinal cyclic pitch and lateral cyclic pitch can be driven to zero at a given forward speed by shifting the cg forward and to the port side, respectively. There also exist pairs of numbers for the longitudinal and lateral cg locations which drive both the cyclic pitch components to zero at a given forward speed. Based on these results, a compromise optimal cg location is obtained such that the cyclic pitch is bounded within ±5° for a BO105 helicopter rotor.Originality/valueThe reduction in the cyclic pitch due to helicopter cg location is found to significantly reduce the maximum magnitudes of the control angles in flight, facilitating the swashplateless rotor concept. In addition, the existence of cg locations which drive the cyclic pitches to zero allows for the use of active cg movement as a way to replace the cyclic pitch control for helicopter MAV's.
Path planning for autonomous UAV via vibrational genetic algorithm
Authors: Volkan Pehlivanoglu Y. , Baysal Oktay , Hacioglu Abdurrahman 
Published: July 2007

PurposeIt is aimed to provide an efficient algorithm for path planning in guidance of autonomous unmanned aerial vehicle (UAV) through 3D terrain environments.Design/methodology/approachAs a stochastic search method, vibrational genetic algorithm (VGA) is improved and used to accelerate the algorithm for path planning.FindingsUsing VGA, an efficient path planning algorithm for autonomous UAV was obtained under low population rate and short generation cycle conditions.Originality/valueVGA decreased the required time for optimal path solution beside its simplicity. Low population rate and short generation cycle are the main benefits of VGA.
Organising for voting rights of people with disabilities in Lebanon: reflections for activists
Authors: Wehbi Samantha , El‐Lahib Yahya 
Published: July 2007

PurposeThrough a reflection on a recent voting rights campaign for people with disabilities in Lebanon, the article aims to contribute to a body of literature that seeks to challenge the marginalisation of people with disabilities; and aims to share our reflections with others interested in deeper thinking on the global impacts on their day‐to‐day work.Design/methodology/approachThe article begins with a background discussion of the Lebanese context and the voting rights campaign, followed by an analysis of rights‐based work through a discussion of key issues faced by community activists.FindingsThe analysis highlights the impact of global forces on local grassroots work through the following issues: formalisation of relationships between national government organisations (NGOs); professionalisation within NGOs; contentious dealings with the state; the meanings and uses of diversity and international political relations.Originality/valueThere is a dearth of published studies on the disability‐rights movement in the Arab region; more specifically, the article provides a critical reflection on the changes facing the movement in Lebanon, where there are no published studies on the topic. This article would be of value to activists in other parts of the world interested in the changes facing activism on disability rights or other issues.
Lysine enhances methionine content by modulating the expression of S‐adenosylmethionine synthase
Authors: Hacham Yael , Song Luhua , Schuster Gadi , Amir Rachel 
Published: July 2007

SummaryLysine and methionine are two essential amino acids whose levels affect the nutritional quality of cereals and legume plants. Both amino acids are synthesized through the aspartate family biosynthesis pathway. Within this family, lysine and methionine are produced by two different branches, the lysine branch and the threonine–methionine branch, which compete for the same carbon/amino substrate. To elucidate the relationship between these biosynthetic branches, we crossed two lines of transgenic tobacco plants: one that overexpresses the feedback‐insensitive bacterial enzyme dihydrodipicolinate synthase (DHPS) and contains a significantly higher level of lysine, and a second that overexpresses Arabidopsis cystathionine γ‐synthase (AtCGS), the first unique enzyme of methionine biosynthesis. Significantly higher levels of methionine and its metabolite, S‐methylmethionine (SMM), accumulated in the newly produced plants compared with plants overexpressing AtCGS alone, while the level of lysine remained the same as in those overexpressing DHPS alone. The increased levels of methionine and SMM were correlated with increases in the mRNA and protein levels of AtCGS and a reduced mRNA level for the genes encoding S‐adnosylmethionine (SAM) synthase, which converts methionine to SAM. Reduction in SAMS expression level leads most probably to the reduction of SAM found in plants that feed with lysine. As SAM is a negative regulator of CGS, this reduction leads to higher expression of CGS and consequently to an increased level of methionine. Elucidating the relationship between lysine and methionine synthesis may lead to new ways of producing transgenic crop plants containing increased methionine and lysine levels, thus improving their nutritional quality.
Clinical, neurological and clinicopathological signs, treatment and outcome of metaldehyde intoxication in 18 dogs
Authors: Yas‐Natan E. , Segev G. , Aroch I. 
Published: July 2007

Objectives: To describe the clinical signs, clinicopathological abnormalities and outcome of metaldehyde intoxication in dogs. Methods: Medical records of dogs presenting between 1989 and 2005 with a diagnosis of metaldehyde toxicity were reviewed retrospectively. Data obtained from the medical record included signalment, history, clinical signs, laboratory tests results, hospitalisation period length, treatments and outcome. Results: Eighteen dogs fulfilled the inclusion criteria. The most prevalent clinical signs were seizures, hyperthermia, tachycardia and muscle tremors. Serum biochemistry abnormalities included increased serum muscle enzymes activities, acidaemia (six dogs) and decreased blood bicarbonate (eight dogs). Treatment was symptomatic and supportive. Hyperbilirubinaemia was observed in two dogs. Diazepam was the most commonly used anticonvulsant followed by phenobarbitone and pentobarbital. General inhalant anaesthesia was required in nine of 18 dogs with seizures unresponsive to anticonvulsants. The survival was 83 per cent (15 of 18 dogs). Clinical Significance: This clinical study recorded, for the first time in the veterinary literature, several clinicopathological abnormalities from severely intoxicated dogs. Metabolic acidosis was common, while acute or delayed hepatotoxicity was an uncommon complication.
Determination of reference arterial blood pressure values by indirect methods for Kangal dogs
Authors: Sanan T. B. , Arslan M. 
Published: July 2007

Objectives:To obtain reference arterial blood pressure values from Kangal dogs, a local giant breed found in Turkey.Methods:Arterial blood pressure measurements were obtained from 48 healthy Kangal dogs using oscillometric and Doppler techniques. The ages of the dogs ranged from two to 96 months, with a mean (sd) age of 36 (16) months.Results:The effect of age on systolic, diastolic and mean arterial pressures determined by the oscillometric technique and on systolic pressure determined by the Doppler technique was significant (P<0·001). Blood pressure was found to be higher in mature dogs compared with that in immature dogs. The effect of sex and the interaction between age and sex were not significant (P>0·05). There was a direct relationship between age and oscillometric systolic, diastolic and mean arterial pressures and Doppler systolic arterial blood pressure both in the whole group and the immature group (P<0·05). Correlation between age and systolic arterial blood pressure measured either by oscillometric or Doppler techniques was not significant in the mature group.ClinicalSignificance:The Kangal dog is bred in various countries including Turkey. It is known that giant breed dogs, such as the Kangal dog, are predisposed to cardiovascular disease. Canine arterial blood pressure values are highly breed and age dependent, so a reference value for any other breed is inappropriate for Kangal dogs. Therefore, it is important to measure arterial blood pressure of Kangal dogs.
Physical Inactivation of
Toxoplasma gondii
Oocysts in Water
Authors: Wainwright Katlyn E. , Lagunas-Solar Manuel , Miller Melissa A. , Barr Bradd C. , Gardner Ian A. , Pina Cecilia , Melli Ann C. , Packham Andrea E. , Zeng Nolan , Truong Tin , Conrad Patricia A. 
Published: July 2007

ABSTRACT

Inactivation of
Toxoplasma gondii
oocysts occurred with exposure to pulsed and continuous UV radiation, as evidenced by mouse bioassay. Even at doses of ≥500 mJ/cm
2
, some oocysts retained their viability.