bluuebunny/crossref_metadata_2025 huggingface dataset:
Lectin activity in fruiting bodies of the edible mushroom Tricholoma mongolicum
Authors: Wang H. X. , Ng T. B. , Ooi V. E. C.
Published: July 2007

This study was undertaken to ascertain the existence and some of the characteristics of lectin in the fruiting bodies of the edible mushroom Tricholoma mongolicum. The fractionation procedure utilized entailed aqueous extraction, (NH4)2SO4 precipitation, dialysis, ion exchange chromatography on DEAE‐Sepharose and gel filtration on Sephadex G‐100. A similar procedure has been successfully employed for isolating lectins from cultured mycelia of the same species. It was found that the fruiting body lectin could not be purified with the same facility as the mycelial lectins. Although lectins from both fruiting bodies and cultured mycelia were adsorbed on DEAE‐Sepharose and possessed similar carbohydrate specificities, the fruiting body lectin was adsorbed on ConA‐Sepharose and hence probably glycoprotein in nature whereas the mycelial lectins are unglycosylated proteins.
Down‐regulation of protein kinase C‐α detected in human colorectal cancer
Authors: Suga Kenji , Sugimoto Isamu , Ito Hisao , Hashimoto Eikichi
Published: July 2007

The down‐regulation of protein kinase C (PKC) was examined by Western blot procedure on about 30 tissue samples derived from human colorectal cancer and the corresponding normal mucosa. PKC‐α down‐regulation was detected in 60% of the cancer tissues compared with the respective normal mucosa and was observed in a higher frequency with the tissues under more advanced cancer stages. However, the frequencies of the down‐regulation of PKC‐δ and PKC‐ζ were lower than that of PKC‐α. These results suggest that a decreased level of PKC‐α may affect the cell growth and tumor promotion in colorectal tissue.
Repeated mild heat shock delays ageing in cultured human skin fibroblasts
Authors: Rattan Suresh I. S.
Published: July 2007

The effects of repetitive mild heat shock (30 min, 41° C) on growth and various cellular and biochemical characteristics of human skin fibroblasts undergoing ageing in vitro were analysed. Human skin ceils not only tolerated more than 30 repeated heat shocks throughout their replicative lifespan, but also maintained several characteristics of young cells until late in life. Whereas the growth rates, population doubling rates, and cumulative population doubling levels achieved in vitro remained unaffected, age‐related changes in cellular morphology, cell size, cytoskeletal organisation, autofluorescence and neutral β‐galactosidase activity were significantly slowed down by repeated mild heat shock. These hormesis‐like effects of stress‐induced defence processes can be useful to elucidate the role of maintenance and repair mechanisms in ageing.
Erythrocyte antioxidant systems protect cultured endothelial cells against oxidant damage
Authors: Richards Ross S. , Roberts Timothy K. , Dunstan R. Hugh , McGregor Neil R. , Butt Henry L.
Published: July 2007

A study was undertaken to assess the ability of the erythrocyte to protect other tissues against oxidative damage. Radiolabelled (51Cr) human umbilical vein endothelial cells (HUVEC) were incubated with erythrocytes and neutrophils activated with phorbol myristate acetate (PMA). Damage to the endothelial cells was indicated by release of radioactivity into the suspending medium. We found that the co‐incubation of HUVEC with an increasing range of erythrocyte concentrations resulted in a dose‐dependent reduction in the release of radioactivity. When the ability of superoxide to cross the erythrocyte membrane or the glutathione systems was inhibited, the extent of endothelial cell damage increased. Inhibition of the catalase system did not affect results. It was concluded that the erythrocytes afforded some protection against oxidative damage to the endothelial cells by taking up and deactivating the superoxide ions. This protection depends upon intact erythrocyte antioxidant systems. These data support the hypothesis that erythrocytes can provide antioxidant protection to other tissues in vivo.
Comparison of kinetic properties of amine oxidases from sainfoin and lentil and immunochemical characterization of copper/quinoprotein amine oxidases
Authors: Zajoncová Ludmila , Frébort Ivo , Luhová Lenka , Sebela Marek , Galuszka Petr , Pec Pavel
Published: July 2007

Kinetic properties of novel amine oxidase isolated from sainfoin (Onobrychis viciifolia) were compared to those of typical plant amine oxidase (EC 1.4.3.6) from lentil (Lens culinaris). The amine oxidase from sainfoin was active toward substrates, such as 1,5‐diaminopentane (cadaverine) with Km of 0.09 mM and 1,4‐diaminobutane (putrescine) with Km of 0.24 mM. The maximum rate of oxidation for cadaverine at saturating concentration was 2.7 fold higher than that of putrescine. The amine oxidase from lentil had the maximum rate for putrescine comparable to the rate of sainfoin amine oxidase with the same substrate. Both amine oxidases, like other plant Cu‐amine oxidases, were inhibited by substrate analogs (1,5‐diamino‐3‐pentanone, 1,4‐diamino‐2‐butanone and aminoguanidine), Cu2+ chelating agents (diethyltriamine, 1,10‐phenanthroline, 8‐hydroxyquinoline, 2,2′‐bipyridyl, imidazole, sodium cyanide and sodium azide), some alkaloids (L‐lobeline and cinchonine), some lathyrogens (β‐aminopropionitrile and aminoacetonitrile) and other inhibitors (benzamide oxime, acetone oxime, hydroxylamine and pargyline). Tested by Ouchterlony's double diffusion in agarose gel, polyclonal antibodies against the amine oxidase from sainfoin, pea and grass pea cross‐reacted with amine oxidases from several other Fabaceae and from barley (Hordeum vulgare) of Poaceae, while amine oxidase from the filamentous fungus Aspergillus niger did not cross‐react at all. However, using Western blotting after SDS‐PAGE with rabbit polyclonal antibodies against the amine oxidase from Aspergillus niger, some degree of similarity of plant amine oxidases from sainfoin, pea, field pea, grass pea, fenugreek, common melilot, white sweetclover and Vicia panonica with the A. niger amine oxidase was confirmed.
Fatty acid profile of Escherichia coli during the heat‐shock response
Authors: Mejía Ricardo , Gómez‐Eichelmann M. Carmen , Fernández Marta S.
Published: July 2007

The 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

In 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

In 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

The 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

Inactivation 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

The 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

Nitric 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

We 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

Here 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

The 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

A 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.
Neuromodulation for Lower Urinary Tract Dysfunction – An Update
Authors: Hussain Zahid , Harrison Simon C. W.
Published: July 2007

The aim of this review is to provide an update on the use of neuromodulation using sacral nerve stimulation for the treatment of disorders of the lower urinary tract. Neuromodulation using the InterStim® system (Medtronic Inc.) is now accepted as an established therapeutic option for patients with detrusor overactivity, and for women with retention or severe voiding difficulties. However, the use of nerve stimulation in modulating lower urinary tract function has to be regarded as a technique that is in its infancy. Much has yet to be learned about the mechanism by which neuromodulation exerts its effects and there is a need to better define the clinical indications for the treatment. There is also work to be done in terms of optimising stimulation delivery, both in anatomical and electronic terms.
Optimal location of centre of gravity for swashplateless helicopter UAV and MAV
Authors: Ganguli Ranjan , Jehnert Beatrix , Wolfram Jens , Voersmann Peter
Published: July 2007

Purpose

To 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/approach

An 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.

Findings

It 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/value

The 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

Purpose

It is aimed to provide an efficient algorithm for path planning in guidance of autonomous unmanned aerial vehicle (UAV) through 3D terrain environments.

Design/methodology/approach

As a stochastic search method, vibrational genetic algorithm (VGA) is improved and used to accelerate the algorithm for path planning.

Findings

Using VGA, an efficient path planning algorithm for autonomous UAV was obtained under low population rate and short generation cycle conditions.

Originality/value

VGA 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

Purpose

Through 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/approach

The 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.

Findings

The 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/value

There 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

Lysine 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

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.
Alternative Host Model To Evaluate
Aeromonas
Virulence
Authors: Froquet Romain , Cherix Nathalie , Burr Sarah E. , Frey Joachim , Vilches Silvia , Tomas Juan M. , Cosson Pierre
Published: July 2007

Bacterial virulence can only be assessed by confronting bacteria with a host. Here, we present a new simple assay to evaluate
Aeromonas
virulence, making use of
Dictyostelium
amoebae as an alternative host model. This assay can be modulated to assess virulence of very different
Aeromonas
species.
Molecular Characterization of a Novel
ortho
-Nitrophenol Catabolic Gene Cluster in
Alcaligenes
sp. Strain NyZ215
Authors: Xiao Yi , Zhang Jun-Jie , Liu Hong , Zhou Ning-Yi
Published: July 2007

Alcaligenes
sp. strain NyZ215 was isolated for its ability to grow on
ortho
-nitrophenol (ONP) as the sole source of carbon, nitrogen, and energy and was shown to degrade ONP via a catechol ortho-cleavage pathway. A 10,152-bp DNA fragment extending from a conserved region of the catechol 1,2-dioxygenase gene was obtained by genome walking. Of seven complete open reading frames deduced from this fragment, three (
onpABC
) have been shown to encode the enzymes involved in the initial reactions of ONP catabolism in this strain. OnpA, which shares 26% identity with salicylate 1-monooxygenase of
Pseudomonas stutzeri
AN10, is an ONP 2-monooxygenase (EC 1.14.13.31) which converts ONP to catechol in the presence of NADPH, with concomitant nitrite release. OnpC is a catechol 1,2-dioxygenase catalyzing the oxidation of catechol to
cis
,
cis
-muconic acid. OnpB exhibits 54% identity with the reductase subunit of vanillate
O
-demethylase in
Pseudomonas fluorescens
BF13. OnpAB (but not OnpA alone) conferred on the catechol utilizer
Pseudomonas putida
PaW340 the ability to grow on ONP. This suggests that OnpB may also be involved in ONP degradation in vivo as an
o
-benzoquinone reductase converting
o
-benzoquinone to catechol. This is analogous to the reduction of tetrachlorobenzoquinone to tetrachlorohydroquinone by a tetrachlorobenzoquinone reductase (PcpD, 38% identity with OnpB) in the pentachlorophenol degrader
Sphingobium chlorophenolicum
ATCC 39723.
The
las
Enzymes Control Pyruvate Metabolism in
Lactococcus lactis
during Growth on Maltose
Authors: Solem Christian , Koebmann Brian , Yang Fen , Jensen Peter R.
Published: July 2007

The fermentation pattern of
Lactococcus lactis
with altered activities of the
las
enzymes was examined on maltose. The wild type converted 65% of the maltose to mixed acids. An increase in phosphofructokinase or lactate dehydrogenase expression shifted the fermentation towards homolactic fermentation, and with a high level of expression of the
las
operon the fermentation was homolactic.
Regulation of airway goblet cell mucin secretion by tyrosine phosphorylation signaling pathways
Authors: Abdullah Lubna H. , Davis C. William
Published: July 2007

Mucus hyperproduction in pulmonary obstructive diseases results from increased goblet cell numbers and possibly increased cellular mucin synthesis, occurring in response to inflammatory mediators acting via receptor tyrosine kinases (RYK) and tyrosine phosphorylation (Y-Pi) signaling pathways. Yet, increased mucin synthesis does not lead necessarily to increased secretion, as mucins are stored in secretory granules and secreted in response to extracellular signals, commonly assumed to be mediated by G protein-coupled receptors (GPCRs). We asked whether activation 1) of Y-Pi signaling pathways, in principal, and 2) of the novel PKC isoform, nPKCδ, by Y-Pi, specifically, might lead to regulated mucin secretion. nPKCδ in SPOC1 cells was tyrosine phosphorylated by exposure to purinergic agonist (ATPγS) or PMA, actions that were blocked by the Src kinase inhibitor, PP1. Mucin secretion, however, was not affected by PP1. Hence, activation of nPKCδ by Y-Pi is unlikely to participate in GPCR-related mucin secretion. Mucin secretion from both SPOC1 and normal human bronchial epithelial (NHBE) cells was stimulated by generalized protein Y-Pi induced by the tyrosine phosphatase inhibitor, pervanadate (PV). PV-induced SPOC1 cell mucin secretion was not affected by inhibition of Src kinases (genistein or PP1), or of PI3 kinase (LY-294002). MAP kinase pathway inhibitors, RAF1 kinase inhibitor-I and U0126 (MEK), inhibited SPOC1 cell PV-induced secretion by ∼50%. Significantly, the phospholipase C (PLC) inhibitor, U-73122, essentially abolished PV- and ATPγS-induced mucin secretion from both SPOC1 and NHBE cells. Hence, PLC signaling may play a key role in regulated mucin secretion, whether the event is initiated by mediators interacting with GPCRs or RYKs.
Endothelin-induced contraction of bronchiole and pulmonary arteriole smooth muscle cells is regulated by intracellular Ca2+oscillations and Ca2+sensitization
Authors: Perez-Zoghbi Jose F. , Sanderson Michael J.
Published: July 2007

Endothelin-1 (ET) induces increases in intracellular Ca2+concentration ([Ca2+]i), Ca2+sensitization, and contraction of both bronchiole and pulmonary arteriole smooth muscle cells (SMCs) and may play an important role in the pathophysiology of asthma and pulmonary hypertension. However, because it remains unclear how changes in [Ca2+]iand the Ca2+sensitivity regulate SMC contraction, we have studied mouse lung slices with phase-contrast and confocal microscopy to correlate the ET-induced contraction with the changes in [Ca2+]iand Ca2+sensitivity of bronchiole and arteriole SMCs. In comparison with acetylcholine (ACh) or serotonin (5-HT), ET induced a stronger and long-lasting contraction of both bronchioles and arterioles. This ET-induced contraction was associated with prominent asynchronous Ca2+oscillations that were propagated as Ca2+waves along the SMCs. These Ca2+oscillations were mediated by cyclic intracellular Ca2+release and required external Ca2+for their maintenance. Importantly, as the frequency of the Ca2+oscillations increased, the extent of contraction increased. ET-induced contraction was also associated with an increase in Ca2+sensitivity. In “model” slices in which the [Ca2+]iwas constantly maintained at an elevated level by pretreatment of slices with caffeine and ryanodine, the addition of ET increased bronchiole and arteriole contraction. These results indicate that ET-induced contraction of bronchiole and arteriole SMCs is regulated by the frequency of Ca2+oscillations and by increasing the sensitivity of the contractile machinery to Ca2+.
Editorial Introduction
Authors: Thomas Peter
Published: July 2007

Historical Materialism has previously published a significant number of studies from the contemporary 'Marx Renaissance'. Roberto Finelli's intervention into the debate over Chris Arthur's The New Dialectic and Marx's 'Capital' provides an opportunity to consider the international reverberations of this movement and its political presuppositions and consequences. Working in a very different tradition of Marxism, Finelli's interpretation of Marx has decisive similarities with Arthur's reading of the importance of Hegel's Logic for the conceptual structure of Capital. Yet whereas Arthur argues for a 'direct homology', Finelli proposes a heuristic 'analogy'. The different conclusions reached by the two theorists reflect different orientations, both theoretical and political. Comparison to theses of the Italian workerist tradition and other contemporary readings of Marx suggest that these differences are best comprehended in a political rather than solely intellectual register. Despite their differences, these various research projects are in agreement regarding the necessity of deriving concrete strategies for the contemporary socialist movement from theoretical debate.
Political Marxism and Value Theory: Bridging the Gap between Theory and History
Authors: Knafo Samuel
Published: July 2007

This article proposes a reading of value theory firmly entrenched in the historicist framework of political Marxism; one which gives precedence to social relations and historical development over abstract logic and formal models. It argues that Marx's theory of value can be read as elucidating how social norms are being unwittingly created under capitalism by contrast with precapitalist societies. The article is divided into two sections. The first examines the two main ways in which value is considered within Marxism and highlights the problems that can emerge when taking into account the issue of the specificity of capitalism. The second section offers an alternative formulation of value theory grounded in the notion of alienation. This leads to the conclusion that the idea that value is shaped by labour refers to a political fact about decisions concerning the organisation of the labour process, rather than an economic fact about the expenditure of labour in the process of production. Value reflects the class struggles over the labour process and the norms that govern social life, rather than an embodied quantity of socially necessary labour-time expended within the labour process.
Cul4A is required for hematopoietic stem-cell engraftment and self-renewal
Authors: Li Binghui , Jia Nan , Waning David L. , Yang Feng-Chun , Haneline Laura S. , Chun Kristin T.
Published: July 2007

Several hematopoietic stem-cell (HSC) regulators are controlled by ubiquitin-mediated proteolysis, so the ubiquitin pathway might modulate HSC function. However, this hypothesis has not been formally tested. Cul4A encodes a core subunit of one ubiquitin ligase. Whereas Cul4A-deficient embryos die in utero, Cul4A-haploinsufficient mice are viable but exhibit abnormal hematopoiesis (fewer erythroid and primitive myeloid progenitors). Given these data, we examined whether Cul4A+/− HSCs might also be impaired. Using bone marrow transplantation assays, we determined that Cul4A+/− HSCs exhibit defects in engraftment and self-renewal capacity. These studies are the first to demonstrate that ubiquitin-mediated protein degradation is important for HSC function. Further, they indicate that a Cul4A ubiquitin ligase targets for degradation one or multiple HSC regulators.
Ester prodrugs of morphine improve transdermal drug delivery: a mechanistic study
Authors: Wang Jhi-Joung , Sung K C , Huang Jeng-Fen , Yeh Chih-Hui , Fang Jia-You
Published: July 2007

Two alkyl esters of morphine, morphine propionate (MPR) and morphine enanthate (MEN), were synthesized as potential prodrugs for transdermal delivery. The ester prodrugs could enhance transdermal morphine delivery. The mechanisms of this enhancing effect were elucidated in this study. Both prodrugs were more lipophilic than their parent drug as evaluated by the skin/vehicle partition coefficient (log P) and capacity factor (log K′). The in-vitro skin permeation of morphine and its prodrugs from pH 6 buffer was in the order of MEN > MPR > morphine. MPR and MEN respectively enhanced the transdermal delivery of morphine by 2- and 5-fold. A contrary result was observed when using sesame oil as the vehicle. The prodrugs were stable against chemical hydrolysis in an aqueous solution, but were readily hydrolysed to the parent drug when exposed to skin homogenate and esterase. Approximately 98% MPR and ∼75% MEN were converted to morphine in an in-vitro permeation experiment. The viable epidermis/dermis contributed to a significant resistance to the permeation of ester prodrugs. According to the data of skin permeation across ethanol-, α-terpineol-, and oleic acid-pretreated skin, MEN was predominantly transported via lipid bilayer lamellae in the stratum corneum. The intercellular pathway was not important for either morphine or MPR permeation.
Study on the mechanisms of an extract of Salvia miltiorrhiza on the regulation of permeability of endothelial cells exposed to tumour necrosis factor-α
Authors: Ding Mei , Yuan Ying-Jin
Published: July 2007

Exposure of endothelial cells to tumour necrosis factor-α (TNF-α) results in increased endothelial permeability, accompanied by a loss of cell-cell adherence junctions. The importance of tyrosine phosphatase and kinase activity in oxidant-mediated loss of cell junction structures has been demonstrated. The purpose of this study was to determine whether tyrosine phosphorylation contributes to TNF-α-imediated disorganization of endothelial cell junctions and how an extract of Salvia miltiorrhiza (ESM) and its active ingredients, Danshensu (DSS) and salvianolic acid B (Sal B), exert their protective effect in maintaining cell integrity. Immunoblotting results indicated that TNF-α exposure resulted in tyrosine phosphorylation of junctional proteins such as vascular endothelial cadherin and β-catenin, which was attenuated by ESM and its active ingredients DSS and Sal B. In addition, immunoprecipitation showed ESM and its active ingredients prevented β-catenin disassociation from the cytoskeleton in TNF-α-treated human umbilical vein endothelial cells. The results suggest that TNF-α produced biological effects at least partly by junctional protein phosphotyrosine modifications by increasing the total cellular phosphorylation level. It could be concluded that ESM and its active ingredients were effective at eliminating the factors leading to the rise in cellular phosphorylation, thus helping to maintain the integrity of endothelial junction structure.
Stationarity tests in time series model building
Authors: Ali Mukhtar M. , Thalheimer Richard
Published: July 2007

Optimum non‐parametric tests for stationarity of a stochastic process against location and scale shift alternatives are explored. Usefulnesss of these tests in detecting a suitable differencing transformation that reduces a non‐stationary time series to a stationary one is illustrated with a number of previously analysed real life data.
Forecasting accounting data: A multiple time‐series analysis
Authors: Hillmer S. C. , Larcker D. F. , Schroeder D. A.
Published: July 2007

This paper examines the relative forecasting performance of multivariate time‐series analysis. One hundred consecutive monthly observations for three accounting series were obtained from a manufacturing division of a large corporation. Regression, univariate time‐series, transfer‐function, and multiple time‐series models were identified, estimated, and used to forecast each accounting series. The multiple time‐series model yielded the smallest forecast variances.
Management and change in northern Nigerian local government
Authors: O'Donovan Ita
Published: July 2007

This paper looks at some recent changes introduced by the Federal Government of Nigeria which seek a return to civilian rule in a stable polity. A first step in this policy has been completed with the election of chairmen and councillors at the local government level. The stated purpose of this initiative is to encourage ‘grass roots democracy’, which is expected to mobilize local action for urban and rural development. It is envisaged that local politicians and local administration will work together to this end. The paper concentrates on the consequences of the policy for the management of local government in Northern Nigeria, in which the predominant need is for rural development. The resource and management issues that arise for local government from the introduction of this polity are discussed under the following headings: finance, material resources, human resources and political relationships. The measures adopted appear radical, but have not led to a situation in which local government can easily predict what resources will be available to it. The question that is addressed is how, in an uncertain environment, local governments might use the powers and resources that are within their control to facilitate rural development in the Northern States. Suggestions are made as to what a management agenda should be and how this might be achieved through appropriate management systems and improved training.
Die Verteilung der Nukleonen in schweren Atomkernen
Authors: Mittelstaedt P.
Published: July 2007

I. Einleitung. – II. Experimentelles. A. Messungen der Gesamtverteilung. B. Messungen der Protonenverteilung. 1. Massendefekte, Weizsäcker‐Bethe‐Formel. 2. Energiedifferenz bei Spiegelkernen. 3. Protoneneinfangexperimente. 4. Lebensdauer des α‐Zerfalls. 5. Energieniveaus des μ‐Meson‐Atoms. 6. Elektronenstreuung. – III. Theoretische Deutung. 1. Herleitung der Kollektivpotentiale. 2. Bestimmung der Nukleonenverteilungen. 3. Ergebnisse. – IV. Zusammenfassung. – Literatur.
Some Remarks on the Higgs Mechanism
Authors: Łopuszański Jan
Published: July 2007

We show that at least one of the auxiliary one‐component fields in the Higgs Model – the field ϕ – is not a Lorentz scalar and that it is probably not local with respect to the current. Our conclusion is that we cannot prescribe to the field ϕ a direct physical meaning.

In case ϕ is not local with respect to the current it is likely that the zero eigenvalue of the mass operator does not appear in the theory at all.

In case ϕ is quasilocal with respect to j0, such an eigenvalue appears at least in the original Model and the mass spectrum can be different for different versions of the Model. We conjecture that this can be explained with help of the theory of unitarily inequivalent representations.

We display the difficulty in translating into the quantal language the classical procedure leading from the original Model to the variant of unitary gauge. We hope that with help of unitarily inequivalent representations this difficulty can be resolved.

We exhibit the fact that in the Higgs Model the whole gauge group does not have a direct physical meaning, in contradistinction to electrodynamics, where the local gauge group only has no physical significance.