bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrogenic light reactions in photosystem I: resolution of electron-transfer rates between the iron-sulfur centers.
Authors: Sigfridsson K , Hansson O , Brzezinski P
Published: May 2006

Flash-induced voltage changes (electrogenic events) in photosystem I particles from spinach, oriented in a phospholipid layer, have been studied at room temperature on a time scale ranging from 1 micros to several seconds. A phospholipid layer containing photosystem I particles was adsorbed to a Teflon film separating two aqueous compartments. Voltage changes were measured across electrodes immersed in the compartments. In the absence of added electron donors and acceptors, a multiphasic voltage increase, associated with charge separation, was followed by a decrease, associated with charge recombination. Several kinetic phases were resolved: a rapid (<1 micros) increase, ascribed to electron transfer from the primary electron donor P700 to the iron-sulfur electron acceptor FB, was followed by a slower, biphasic increase with time constants of 30 and 200 micros. The 30-micros phase is assigned to electron transfer from FB to the iron-sulfur center FA. The voltage decrease had a time constant of 90 ms, ascribed to charge recombination from FA to P700. Upon chemical prereduction of FA and FB the 30- and 200-micros phases disappeared and the decay time constant was accelerated to 330 micros, assigned to charge recombination from the phylloquinone electron acceptor (A1) or the iron-sulfur center FX to P700.
The glucocorticoid receptor type II complex is a target of the HIV-1 vpr gene product.
Authors: Refaeli Y , Levy D N , Weiner D B
Published: May 2006

The vpr gene of human immunodeficiency virus type 1 (HIV-1) encodes a 15-kDa virion-associated protein that functions as a regulator of cellular processes linked to the HIV life cycle. We report the interaction of a 41-kDa cytosolic viral protein R interacting protein 1 (Rip-1) with Vpr in vitro. Rip-1 displays a wide tissue distribution, including relevant targets of HIV infection. Vpr protein induced nuclear translocation of Rip-1, as did glucocorticoid receptor (GR)-II-stimulating steroids. Importantly, Vpr and Rip-1 coimmunoprecipitated with the human GR as part of an activated receptor complex. Vpr complementation of a vpr mutant virus was also mimicked by GR-II-stimulating steroids. Vpr and GR-II actions were inhibited by mifepristone, a GR-II pathway inhibitor. Together these data directly link the activity of the vpr gene product to the glucocorticoid steroid pathway and provide a biochemical mechanism for the cellular and viral activity of Vpr, as well as suggest that a unique class of antivirals, which includes mifepristone (RU486), may influence HIV-1 replication.
Azospirillum melinis sp. nov., a group of diazotrophs isolated from tropical molasses grass
Authors: Peng Guixiang , Wang Huarong , Zhang Guoxia , Hou Wei , Liu Yang , Wang En Tao , Tan Zhiyuan
Published: May 2006

Fifteen bacterial strains isolated from molasses grass (Melinis minutiflora Beauv.) were identified as nitrogen-fixers by using the acetylene-reduction assay and PCR amplification of nifH gene fragments. These strains were classified as a unique group by insertion sequence-PCR fingerprinting, SDS-PAGE protein patterns, DNA–DNA hybridization, 16S rRNA gene sequencing and morphological characterization. Phylogenetic analysis of the 16S rRNA gene indicated that these diazotrophic strains belonged to the genus Azospirillum and were closely related to Azospirillum lipoferum (with 97.5 % similarity). In all the analyses, including in addition phenotypic characterization using Biolog MicroPlates and comparison of cellular fatty acids, this novel group was found to be different from the most closely related species, Azospirillum lipoferum. Based on these data, a novel species, Azospirillum melinis sp. nov., is proposed for these endophytic diazotrophs of M. minutiflora, with TMCY 0552T (=CCBAU 5106001T=LMG 23364T=CGMCC 1.5340T) as the type strain.
Zobellella denitrificans gen. nov., sp. nov. and Zobellella taiwanensis sp. nov., denitrifying bacteria capable of fermentative metabolism
Authors: Lin Yu-Te , Shieh Wung Yang
Published: May 2006

Two denitrifying strains of heterotrophic, facultatively anaerobic bacteria, designated ZD1Tand ZT1T, were isolated from sediment samples collected from mangrove ecosystems in Taiwan. The isolates were Gram-negative. Cells grown in broth cultures were straight rods that were motile by means of a single polar flagellum. The isolates grew optimally in 1–3 % NaCl, but NaCl was not an absolute requirement for growth; only strain ZT1Tgrew in 13–14 % NaCl. Both isolates grew between 10 and 45 °C, with optimum growth at 30–35 °C. They were capable of anaerobic growth by denitrifying metabolism using nitrate or nitrous oxide as terminal electron acceptors or, alternatively, by fermenting glucose, sucrose or mannitol as substrates. C18 : 1ω7cwas the most abundant fatty acid (32.6–35.7 %). The other major fatty acids included C16 : 1ω7c(27.5–29.4 %) and C16 : 0(20.1–22.0 %). The two isolates had 16S rRNA gene sequence similarity of 96.8 % and shared 94.1–96.8 % sequence similarity with the most closely related species,Oceanimonas doudoroffii,Oceanimonas baumannii,Oceanimonas smirnoviiandOceanisphaera litoralis. They could be distinguished from these species in that they were capable of fermentative metabolism, had relatively high DNA G+C contents (62.0–64.0 mol%) and contained C18 : 1ω7cinstead of C16 : 1ω7cas the most abundant fatty acid. Characterization data accumulated in this study revealed that the two denitrifying isolates could be classified as representatives of two novel species in a new genus,Zobellellagen. nov., withZobellella denitrificanssp. nov. (type strain ZD1T=BCRC 17493T=JCM 13380T) as the type species andZobellella taiwanensissp. nov. (type strain ZT1T=BCRC 17494T=JCM 13381T) as a second species.
ThHog1 controls the hyperosmotic stress response in Trichoderma harzianum
Authors: Delgado-Jarana Jesús , Sousa Sonia , González Fran , Rey Manuel , Llobell Antonio
Published: May 2006

Trichoderma harzianumis a widespread mycoparasitic fungus, able to successfully colonize a wide range of substrates under different environmental conditions. Transcript profiling revealed a subset of genes induced inT. harzianumunder hyperosmotic shock. Thehog1gene, a homologue of the MAPKHOG1gene that controls the hyperosmotic stress response inSaccharomyces cerevisiae, was characterized.T. harzianum hog1complemented thehog1Δ mutation inS. cerevisiae, but showed different features to yeast alleles: improved osmoresistance by expression of thehog1allele and a lack of lethality when thehog1F315Sallele was overexpressed. ThHog1 protein was phosphorylated inT. harzianumunder different stress conditions such as hyperosmotic or oxidative stress, among others. By using a ThHog1-GFP fusion, the protein was shown to be localized in nuclei under these stress conditions. Two mutant strains ofT. harzianumwere constructed: one carrying thehog1F315Sallele, and a knockdownhog1-silenced strain. The silenced strain was highly sensitive to osmotic stress, and showed intermediate levels of resistance against oxidative stress, indicating that the main role of ThHog1 protein is in the hyperosmotic stress response. Stress cross-resistance experiments showed evidences of a secondary role of ThHog1 in oxidative stress. The strain carrying thehog1F315Sallele was highly resistant to the calcineurin inhibitor cyclosporin A, which suggests the existence of links between the two pathways. The two mutant strains showed a strongly reduced antagonistic activity against the plant pathogensPhoma betaeandColletotrichum acutatum, which points to a role of ThHog1 protein in fungus–fungus interactions.
Contributions of Listeria monocytogenes σ B and PrfA to expression of virulence and stress response genes during extra- and intracellular growth
Authors: Kazmierczak Mark J. , Wiedmann Martin , Boor Kathryn J.
Published: May 2006

Listeria monocytogenes σBand PrfA are pleiotropic regulators of stress response and virulence gene expression. Quantitative RT-PCR (qRT-PCR) was used to measure transcript levels ofσB- and PrfA-dependent genes in exponential-phaseL. monocytogeneswild-type and ΔsigBstrains as well as in bacteria exposed to environmental stresses (0.3 M NaCl or growth to stationary phase) or present in the vacuole or cytosol of human intestinal epithelial cells. Stationary-phase or NaCl-exposedL. monocytogenesshowedσB-dependent increases inopuCA(10- and 17-fold higher, respectively) andgadAtranscript levels (77- and 14-fold higher, respectively) as compared to non-stressed, exponential-phase bacteria. While PrfA activity, as reflected byplcAtranscript levels, was up to 95-fold higher in intracellularL. monocytogenesas compared to non-stressed bacteria,σBactivity was only slightly higher in intracellular than in non-stressed bacteria. IncreasedplcAtranscript levels, which were similar in both host cell vacuole and cytosol, were associated with increases in bothprfAexpression and PrfA activity. qRT-PCR assays were designed to measure expression ofprfAfrom each of its three promoter regions. Under all conditions, readthrough transcription from the upstreamplcApromoter was very low. The relative contribution to totalprfAtranscription from theσA-dependent P1prfApromoter ranged from ∼17 % to 30 %, while the contribution of the P2prfAregion, which appears to be transcribed by bothσAandσB, ranged from ∼70 % to 82 % of totalprfAtranscript levels. In summary (i)σBis primarily activated during environmental stress and does not contribute to PrfA activation in intracellularL. monocytogenesand (ii) the partiallyσB-dependent P2prfApromoter region contributes the majority ofprfAtranscripts in both intra- and extracellular bacteria.
Structure and distribution of the slope fish community in the vicinity of the sub‐Antarctic Prince Edward Archipelago
Authors: Pakhomov E. A. , Bushula T. , Kaehler S. , Watkins B. P. , Leslie R. W.
Published: May 2006

Demersal fish community structure, distribution and trophic relationships on the slope (depth range 200–1500 m) of the sub‐Antarctic Prince Edward Islands and surrounding sea rises were investigated during a pilot survey conducted in April 2001 onboard fishing vessel MV Iris. A total of 56 fish taxa were collected during the survey, of which 44 were identified to the species level, seven to the genus level and five to the family level. Among the identified taxa, 36 constituted new records for the area investigated. Total catch per unit effort (cpue) during the survey ranged from 1·1 to 241·2 individuals h−1. Both average fish diversity and total cpue positively correlated with trawling depth. Overall, mean sampling depth and near‐bottom temperature explained 56% of total fish cpue. Hierarchal cluster analysis identified three distinct fish assemblages with pronounced dominant species. Major shifts in fish community composition occurred at 500–600 m and 800–900 m depth strata and could probably be a result of physical and biological vertical zonation. Analysis of the diet of selected fish species showed that they were generalist feeders, consuming predominantly pelagic, including epipelagic, meso‐ and benthopelagic, prey. Diets of six species and nitrogen stable isotope signatures of 22 species revealed that with a few exceptions most fishes occupied the fourth trophic level and were tertiary consumers. Wide variability in carbon isotopic signatures is discussed with respect to alternative, e.g. possible importance of high Antarctic and chemoautotrophic v. photoautotrophic sub‐Antarctic primary production, organic matter sources at the base of deep‐sea food webs.
Female mating decisions: maximizing fitness?
Authors: Barbosa M. , Magurran A. E.
Published: May 2006

Sexual selection theory assumes that maximizing fitness is the ultimate goal in every mating decision. Fitness can be maximized directly by increasing the number of offspring (direct benefits) or indirectly by maximizing offspring's lifetime reproductive success (indirect benefits). Whereas there is considerable evidence in the literature for the influence of mating decisions on direct benefits, indirect benefits have been more elusive. Here, we review the variables that influence mating decisions made by females of freshwater fish and how these affect their fitness directly, as well as indirectly. Females enhance their fitness by matching their mating decisions to current environmental conditions, using a wide range of pre‐ and post‐copulation mechanisms that enable them to maximize benefits from mating. Male sexual traits and courtship displays are signals used by females as a way of assessing male quality in terms of both direct and indirect benefits. Polyandry is very common among freshwater fish species, and indirect benefits have been hypothesized as drivers of its predominance. Despite intensive theoretical work, and multiple suggestions of the effects of indirect benefits, to date no study has been able to demonstrate experimentally the existence of indirect benefits in freshwater fish species. Additionally, most studies of direct benefits measure short‐term benefits of mating decisions. In both cases, lifetime reproductive success is not assessed. Therefore, we are led to conclude that evidence as to whether female mating decisions result in direct and/or indirect benefits in freshwater fish species is still lacking. These results should be considered in light of the ongoing debate about the significance of indirect benefits in female mating decisions.
Salivary cortisol response in mother–infant dyads at high psychosocial risk
Authors: Mörelius E. , Nelson N. , Gustafsson P. A.
Published: May 2006

Objectives  The aim of the present study was to investigate the adrenocortical response to diaper change in mother–infant dyads with psychosocial risk factors.

Material and methods  Twenty‐two mother–infant pairs with well‐defined psychosocial problems were included. The mother–infant pairs were treated for 6 weeks in a daycare programme to improve attachment. Salivary cortisol was measured before and after a diaper change during the first and last weeks of enrolment in the programme. Mothers’ sensitivity towards their infants’ signals was measured using a scale from 1 (highly insensitive) to 9 (highly sensitive) according to Ainsworth.

Results  Median salivary cortisol increased in 15 out of 22 infants after the first diaper change. The increase was most pronounced in the group of infants below 3 months of age (n = 15) where median salivary cortisol increased 170% after the first diaper change (P < 0.05) and decreased 19% after the last diaper change (not significant). Out of these 15 infants, 11 showed an increase in salivary cortisol in response to the first diaper change while four out of 15 did so in response to the last diaper change (P < 0.05). The salivary cortisol response did not change over time in infants aged 3 months or above. A mother’s sensitivity to her child increased significantly (P < 0.001) from the first to the last week. In mothers, median salivary cortisol decreased 38% after the first diaper change (P < 0.05) and 57% after the last diaper change (P = 0.001).

Discussion  A diaper change is normally not perceived as stressful. The stress response caused by a diaper change may illustrate an insufficiency in the mother–infant relationship before treatment. Professional support improved the mothers’ sensitivity and stabilized the stress response to diaper change in the youngest infants.
Association of drug‐serum protein adducts and anti‐drug antibodies in dogs with sulphonamide hypersensitivity: A naturally occurring model of idiosyncratic drug toxicity
Authors: Lavergne S. N. , Danhof R. S. , Volkman E. M. , Trepanier L. A.
Published: May 2006

BackgroundSulphonamide antimicrobials, such as sulphamethoxazole (SMX), provide effective infection prophylaxis in immunocompromised patients, but can lead to drug hypersensitivity (HS) reactions. These reactions also occur in dogs, with a similar time course and clinical presentation as seen in humans.

ObjectivesDrug‐serum adducts and anti‐drug antibodies have been identified in sulphonamide HS humans. The aim of this study was to determine whether similar markers were present in dogs with sulphonamide HS.

MethodsThirty‐four privately owned sulphonamide HS dogs, 10 sulphonamide‐‘tolerant’ dogs, 18 sulphonamide‐naïve dogs, and four dogs experimentally dosed with SMX and the oxidative metabolite SMX‐nitroso, were tested for drug‐serum adducts by immunoblotting, and anti‐drug antibodies by ELISA.

ResultsSulphonamide–serum adducts were found in 10/20 HS dogs tested (50%), but in no tolerant dogs. Anti‐sulphonamide IgG antibodies were detected in 17/34 HS dogs (50%), but in only one tolerant dog; antibody absorbance values were significantly higher in HS dogs. There was a significant association between the presence of sulphonamide–serum adducts and anti‐sulphonamide antibodies (P=0.009). Anti‐drug antibodies were also found in dogs experimentally dosed with SMX‐nitroso followed by SMX, but not in a dog dosed with drug vehicle, followed by SMX.

ConclusionSimilar humoral markers are present in dogs and humans with sulphonamide HS, supporting the use of dogs as a naturally occurring model for this syndrome in humans. These data suggest the potential use of drug‐serum adducts and anti‐drug antibodies as markers for sulphonamide HS. Preliminary data indicate that anti‐sulphonamide antibodies may be triggered by the SMX‐nitroso metabolite, not by the parent drug, in dogs.
Pulmonary sarcoidosis and antiphospholipid syndrome
Authors: TAKAHASHI Fumiyuki , TOBA Michie , TAKAHASHI Kazuhisa , TOMINAGA Shigeru , SATO Koichi , MORIO Yoshiteru , NAKAO Yuta , TAJIMA Ken , MIURA Kayo , UEKUSA Toshimasa , FUKUCHI Yoshinosuke
Published: May 2006

Abstract:  Various autoimmune diseases have been reported to occur in patients with sarcoidosis. However, coexistence of sarcoidosis and antiphospholipid syndrome (APS) is extremely rare. We describe a 59‐year‐old female patient with pulmonary sarcoidosis who had preceding APS. Her previous medical history consisted of a miscarriage and ischemic colitis. She was diagnosed as APS during the onset of a brainstem infarction with positive reaction to β2‐glycoprotein I‐dependent anticardiolipin antibody. Two years later, chest CT revealed enlargement of the hilar and mediastinal lymph nodes and small nodules in the lung fields. Transbronchial lung biopsy demonstrated non‐caseating epithelioid cell granuloma leading to the diagnosis of definite pulmonary sarcoidosis. This is the first APS case where pulmonary involvement with sarcoidosis has been confirmed through lung biopsy. Our case report suggests that APS should be recognized as an accompanying disorder of sarcoidosis.
Chitotriosidase and inflammatory mediator levels in Alzheimer's disease and cerebrovascular dementia
Authors: Di Rosa Michelino , Dell'Ombra Nicola , Zambito Anna Maria , Malaguarnera Mariano , Nicoletti Ferdinando , Malaguarnera Lucia
Published: May 2006

Inflammation has been reported to be involved in the pathogenesis of cerebrovascular dementias (CvDs). This study investigated the involvement of Chitotriosidase (ChT), a chinolitic enzyme mainly produced by activated macrophages, in the pathophysiology of Alzheimer's disease (AD) and ischemic CvD. In addition, the levels of interleukin (IL)‐16, IL‐18, transforming growth factor (TGF) ‐β1 and superoxide anion (O2–) were determined to evaluate the relationship between ChT levels, these cytokines and oxidative stress in both AD and ischemic CvD patients. The levels of ChT and IL‐16, IL‐18, and TGF‐β1 mRNA were investigated using quantitative real‐time polymerase chain reaction on macrophages of peripheral blood of 40 patients with AD, 40 patients with ischemic CvD and 40 non‐demented age‐matched subjects. The results show that ChT, IL‐16 and O2– levels significantly increased in ischemic CvD patients compared with AD patients and were significantly and positively correlated with IL‐18 and O2–. The production of IL‐18 was increased in both AD and ischemic CvD patients. TGF‐β1 expression was higher in AD patients and was inversely correlated with the expression of ChT, IL‐16 and IL‐18, respectively. In non‐demented age‐matched subjects no significant changes in ChT and IL‐16, IL‐18, and TGF‐β1 expression were found. Our results indicate that ChT, IL‐16, IL‐18 and TGF‐β1 are increased in ischemic CvD and AD, confirming that the immune system may play an important role in the development and progression of neurodegenerative disorders. In addition, the present findings suggest that ChT could also play a crucial role in pathological conditions such as CvD in which the inflammatory process is activated.
Effects of arousal‐ and feeding‐related neuropeptides on dopaminergic and GABAergic neurons in the ventral tegmental area of the rat
Authors: Korotkova T. M. , Brown R. E. , Sergeeva O. A. , Ponomarenko A. A. , Haas H. L.
Published: May 2006

Many neuropeptides regulate feeding and arousal; the ventral tegmental area (VTA) is likely to be one site where they act. We used whole‐cell patch‐clamp and single‐unit extracellular recordings to examine the effects of such neuropeptides on the activity of VTA neurons. Substance P (SP; 300 nm) increased the firing rate of the majority of VTA dopaminergic and γ‐aminobutyric acid (GABA)ergic neurons, and induced oscillations in two dopaminergic cells. Corticotropin‐releasing factor (CRF; 200 nm) excited the majority of VTA cells directly, whereas neuropeptide Y (NPY; 300 nm) directly inhibited a subset of dopaminergic and GABAergic cells. Consecutive application of several neuropeptides revealed that all the neurons were excited by at least one of the excitatory neuropeptides SP, CRF or/and orexins. α‐Melanocyte‐stimulating hormone had no effect on dopaminergic cells (at concentrations of 500 nmand 1 µm) and affected only a small proportion of GABAergic neurons. Ghrelin (500 nm), agouti‐related peptide (1 µm); cocaine and amphetamine‐related transcript (500 nm) and leptin (500 nmand 1 µm) did not modulate the firing rate and membrane potential of VTA neurons. Single‐cell reverse transcription polymerase chain reaction analysis showed that all NPY receptors were present in VTA neurons, and all but one cell expressed NPY and/or at least one NPY receptor. CRF was expressed in 70% of dopaminergic VTA cells; the expression of CRF receptor 2 was more abundant than that of receptor 1. These findings suggest a link between the ability of neuropeptides to promote arousal and their action on VTA neurons.
Human immunodeficiency virus‐encoded Tat activates glycogen synthase kinase‐3β to antagonize nuclear factor‐κB survival pathway in neurons
Authors: Sui Ziye , Sniderhan Lynn F. , Fan Shongshan , Kazmierczak Katarzyna , Reisinger Elizabeth , Kovács Attila D. , Potash Mary Jane , Dewhurst Stephen , Gelbard Harris A. , Maggirwar Sanjay B.
Published: May 2006

The pathogenesis of human immunodeficiency virus type 1 (HIV‐1)‐associated dementia is mediated by neuronal dysfunction and death, brought about by the action of soluble neurotoxic factors that are released by virally infected macrophages and microglia. Paradoxically, many candidate HIV‐1 neurotoxins also possess the ability to activate nuclear factor‐kappa B (NF‐κB), which has a potent pro‐survival effect in primary neurons. The present study explored this conundrum and investigated why NF‐κB might fail to protect neurons that are exposed to candidate HIV‐1 neurotoxins. Here, we evaluated the ability of virus‐depleted conditioned medium produced by HIV‐1‐infected human macrophages (HIV‐MCMs) to modulate NF‐κB activity in neurons. We demonstrated that HIV‐MCMs inhibit the normal signaling pathways that lead to NF‐κB activation in neurons. This inhibitory effect of HIV‐MCM is dependent upon the presence of HIV‐1 Tat, which activates glycogen synthase kinase (GSK)‐3β in neurons. Activation of GSK‐3β, in turn, results in modification of the NF‐κB subunit RelA at serine 468, thereby regulating the physical interaction of RelA with histone deacetylase‐3 corepressor molecules. Furthermore, neutralization of Tat or inhibition of GSK‐3β activity prevents neuronal apoptosis induced by HIV‐MCM. We conclude that HIV‐1 Tat may compromise neuronal function and fate by interfering with normal survival pathways subserved by NF‐κB. These findings may have important therapeutic implications for the management of HIV‐1‐associated dementia.
Self‐Regulation: Reminders and Suggestions from Personality Science
Authors: Cervone Daniel , Shadel William G. , Smith Ronald E. , Fiori Marina
Published: May 2006

La littérature sur l’autorégulation est couramment accusée de faiblesse théorique. Il est possible que les avancées dans les recherches sur la personnalité puissent ouvrir des horizons dans ce secteur. Notre objectif est double. Nous rappelons d’abord des distinctions conceptuelles qui, bien que parfois négligées, sont essentielles dans les études contemporaines sur la personnalité et incontournables pour accéder au niveau théorique dans la littérature sur l’autorégulation. Nous disons ensuite que ceux qui font des études fondamentales et appliquées sur l’autorégulation auraient intérêt à assimiler les progrès récents concernant la dynamique et la structure de la personnalité intra‐individuelle. Nous passons en revue la théorie de base et les recherches sur l’architecture des systèmes de la personnalité intra‐individuelle, ainsi que les retombées de ce travail dans trois domaines d’application: la psychologie du travail/industrielle/organisationnelle, la psychologie clinique et la santé.

The self‐regulation literature commonly is said to lack theoretical order. This paper explores the possibility that advances in personality science may foster clarity in this literature. Our goals are two‐fold. We remind readers of conceptual distinctions that are central to contemporary personality science, that are necessary to the attainment of theoretical order in the self‐regulation literature, yet that sometimes are overlooked. Secondly, we suggest that basic and applied students of self‐regulation would profit by capitalising on recent advances in personality science that explore intra‐individual personality structure and dynamics. We review theory and research on the architecture of intra‐individual personality systems and applications of this work to three domains: health, clinical, and work/industrial/organisation psychology.
Paternal and maternal lineages in the Balkans show a homogeneous landscape over linguistic barriers, except for the isolated Aromuns
Authors: Bosch E. , Calafell F. , González‐Neira A. , Flaiz C. , Mateu E. , Scheil H.‐G. , Huckenbeck W. , Efremovska L. , Mikerezi I. , Xirotiris N. , Grasa C. , Schmidt H. , Comas D.
Published: May 2006

The Balkan Peninsula is a complex cultural mosaic comprising populations speaking languages from several branches of the Indo‐European family and Altaic, as well as culturally‐defined minorities such as the Aromuns who speak a Romance language. The current cultural and linguistic landscape is a palimpsest in which different peoples have contributed their cultures in a historical succession. We have sought to find any evidence of genetic stratification related to those cultural layers by typing both mtDNA and Y chromosomes, in Albanians, Romanians, Macedonians, Greeks, and five Aromun populations. We have paid special attention to the Aromuns, and sought to test genetically various hypotheses on their origins.

MtDNA and Y‐chromosome haplogroup frequencies in the Balkans were found to be similar to those elsewhere in Europe. MtDNA sequences and Y‐chromosome STR haplotypes revealed decreased variation in some Aromun populations. Variation within Aromun populations was the primary source of genetic differentiation. Y‐chromosome haplotypes tended to be shared across Aromuns, but not across non‐Aromun populations. These results point to a possible common origin of the Aromuns, with drift acting to differentiate the separate Aromun communities. The homogeneity of Balkan populations prevented testing for the origin of the Aromuns, although a significant Roman contribution can be ruled out.
Photosynthetic flexibility and ecophysiological plasticity: questions and lessons from Clusia, the only CAM tree, in the neotropics
Authors: Lüttge Ulrich
Published: May 2006

It is the aim of this review to present a monographic survey of the neotropical genus Clusia on scaling levels from molecular phylogeny, metabolism, photosynthesis and autecological environmental responses to ecological amplitude and synecological habitat impact. Clusia is the only dicotyledonous genus with real trees performing crassulacean acid metabolism (CAM). By way of introduction, a brief historical reminiscence describes the discovery of CAM in Clusia and the consequent increase in interest in studying this particular genus of tropical shrubs and trees. The molecular phylogeny of CAM in the genus is compared with that in Kalanchoë and the Bromeliaceae. At the level of metabolism and photosynthesis, the great plasticity of expression of photosynthetic physiotypes, i.e. (i) C3 photosynthesis, (ii) CAM including CAM idling, (iii) CAM cycling and (iv) C3/CAM‐intermediate behaviour, as well as metabolic flexibility in Clusia is illustrated. At the level of autecology, the factors water, irradiance and temperature, which control photosynthetic flexibility, are assessed. The phenotypic plasticity of physiotypes and morphotypes is described. At the level of synecology, the ecological amplitude of Clusia in the tropics and the relations to habitat are surveyed.

Contents

Summary
7

I.
The discovery of crassulacean acid metabolism (CAM) in the trees of Clusia: arrival in the limelight of international research
8

II.
Phylogeny
8

III.
Photosynthetic physiotypes
10

IV.
Metabolic flexibility: organic acid variations
12

V.
The environmental control of photosynthetic flexibility
13

VI.
Phenotypic plasticity: physiotypes and morphotypes
16

VII.
Ecological amplitude and habitat impact
16

VIII.
Conclusions and outlook
21

Acknowledgements
22

References
22
Proinflammatory Cytokine Activities, Matrix Metalloproteinase‐3 Activity, and Sulfated Glycosaminoglycan Content in Synovial Fluid of Dogs with Naturally Acquired Cranial Cruciate Ligament Rupture
Authors: Fujita Yukihiro , Hara Yasushi , Nezu Yoshinori , Schulz Kurt S. , Tagawa Masahiro
Published: May 2006

Objective—To measure and compare activities of interleukin‐1β (IL‐1β), interleukin‐6 (IL‐6), tumor necrosis factor‐α (TNF‐α), and matrix metalloproteinase‐3 (MMP‐3); as well as sulfated glycosaminoglycan (S‐GAG) content in synovial fluid from dogs with cranial cruciate ligament rupture (CCLR) and dogs with clinically normal stifles. To determine whether correlations exist between demographic and disease‐related variables and these synovial markers.

Study Design—Prospective clinical study.

Animals—Dogs with CCLR (n=23) and Beagles with normal stifle joints (n=21).

Methods—Synovial fluid activities of proinflammatory cytokines (IL‐1β, IL‐6, and TNF‐α) were determined by bioassay. MMP‐3 activity was measured using fluorogenic substrate. S‐GAG contents were determined by dimethylmethylene blue dye‐binding assay. Mann–Whitney U‐test was used to compare results from CCLR joints with normal controls. Spearman's rank correlation test was used to evaluate associations between demographic and disease‐related markers and synovial markers.

Results—Mean values for synovial markers were significantly higher in CCLR joints compared with controls. IL‐1β and MMP‐3 were positively correlated with lameness duration.

Conclusions—Activities of proinflammatory cytokines, MMP‐3 activity and S‐GAG contents were significantly elevated in synovial fluid from canine stifle joints with naturally acquired CCLR. These results indicate that there is joint inflammation and increased release of GAGs into synovial fluid, suggesting that these inflammatory changes are associated with depletion of proteoglycan from articular cartilage.

Clinical Relevance—Medical and surgical treatments designed to decrease joint inflammation and breakdown of proteoglycans may be of value in the management of CCLR in the dog.
The Indoor Radiological Problem in Perspective
Authors: Hurwitz Henry
Published: May 2006

Measures to tighten homes to conserve energy, as are being encouraged and subsidized by federal and state governments, may reduce air infiltration by 20% or more. Standard prudent risk‐assessment methodologies predict that, due to increased levels of indoor radon caused by this reduction in ventilation, the added lifetime lung cancer risk to members of the public is of order 200/million people exposed. In situations where the radon source term is unusually high, or extreme reductions in ventilation are made, the added risk can be more than an order of magnitude greater. While these imputed risks are far outside the range that is normally tolerated, no systematic efforts are in progress to mitigate or limit the risk in any way. Furthermore, efforts to determine better the variations in radon source term and the health effects of indoor radon are being deemphasized. The technical background is presented in some detail, and implications with regard to management of risks to the public are discussed.
Quantitative Approaches in Use to Assess Cancer Risk
Authors: Anderson Elizabeth L.
Published: May 2006

Scientists have long used conventional toxicological methods to establish “safe levels of exposure” for chemicals presumed to have threshold health effects or doses below which significant effects are unlikely to occur. These same methods cannot be used to establish safe levels of exposure for non‐threshold pollutants, such as carcinogens. Therefore, Federal regulatory agencies in the United States are using risk assessment methods to provide information for public health policy decisions concerning increases in risk associated with increases in exposure to carcinogenic and other non‐threshold pollutants. Acceptable exposure/risk levels are decided by policymakers who consider descriptions and estimates of risks together with social and economic benefits from the uses of the chemical. This paper focuses on the development of quantitative risk assessment approaches by Federal regulatory agencies in the United States, and identifies the mathematical models currently being used for risk extrapolation, including their inherent uncertainties. The uncertainties and limitations of these methods have led some scientists to question the utility of quantitative risk extrapolation. The experience of the U.S. Environmental Protection Agency (EPA), as summarized in this paper, can provide a realistic basis for evaluating the pros and cons. Finally, shortcomings in current risk assessment methods and their use in policy decisions are explored, and areas for possible improvement, given current scientific knowledge, are identified.
A Probabilistic Analysis of the Passive–Restraint Question
Authors: Graham John D. , Henrion Max
Published: May 2006

The benefits and costs of automobile safety policies are compared using a methodology which explicitly quantifies the uncertainties. The policies addressed include both voluntary and compulsory manual belt usage, nondetachable passive (automatic) seat belts, and air bags. Estimates of the effectiveness and usage rates of these alternatives were obtained in the form of subjective probability distributions from eight experts. Their opinions were combined using equal weighting. The direct economic costs of the technologies were also estimated probabilistically. The number of lives saved and the net benefits of the policies were calculated probabilistically for a range of values of lifesaving. Probabilistic computations and sensitivity analysis were performed by the Demos modelling system using Monte Carlo simulation. The results are highly uncertain and quite sensitive to the value of lifesaving. Nevertheless, they imply that repeal of the passive‐restraint standard is defensible according to the net‐benefit criterion only if a relatively low value is assigned to lifesaving. The degree of uncertainty emphasizes the potential value of demonstration programs to obtain better information.
Fully Developed Heat Transfer to Fluid Flow in Rectangular Passages Filled With Porous Materials
Authors: Haji-Sheikh A.
Published: May 2006

This is a theoretical and numerical study of fully developed forced convection in various rectangular ducts. Each duct is filled with porous materials and the Brinkman model describes the laminar fluid flow inside this fully saturated porous passage. A Fourier series solution provides the exact solution for the velocity field. Also, a Fourier series solution can produce the temperature profile for a condition of constant energy input per unit length. This includes two different wall conditions: a uniform wall temperature at any axial location and a locally uniform heat flux over the boundary. The case of constant wall temperature over the entire passage is also accommodated using a special analytical/numerical solution.
Regulation of glucose transporters by insulin and extracellular glucose in C2C12myotubes
Authors: Nedachi Taku , Kanzaki Makoto
Published: May 2006

It is well established that insulin stimulation of glucose uptake in skeletal muscle cells is mediated through translocation of GLUT4 from intracellular storage sites to the cell surface. However, the established skeletal muscle cell lines, with the exception of L6 myocytes, reportedly show minimal insulin-dependent glucose uptake and GLUT4 translocation. Using C2C12myocytes expressing exofacial-Myc-GLUT4-enhanced cyan fluorescent protein, we herein show that differentiated C2C12myotubes are equipped with basic GLUT4 translocation machinery that can be activated by insulin stimulation (∼3-fold increase as assessed by anti-Myc antibody uptake and immunostaining assay). However, this insulin stimulation of GLUT4 translocation was difficult to demonstrate with a conventional 2-deoxyglucose uptake assay because of markedly elevated basal glucose uptake via other glucose transporter(s). Intriguingly, the basal glucose transport activity in C2C12myotubes appeared to be acutely suppressed within 5 min by preincubation with a pathophysiologically high level of extracellular glucose (25 mM). In contrast, this activity was augmented by acute glucose deprivation via an unidentified mechanism that is independent of GLUT4 translocation but is dependent on phosphatidylinositol 3-kinase activity. Taken together, these findings indicate that regulation of the facilitative glucose transport system in differentiated C2C12myotubes can be achieved through surprisingly acute glucose-dependent modulation of the activity of glucose transporter(s), which apparently contributes to obscuring the insulin augmentation of glucose uptake elicited by GLUT4 translocation. We herein also describe several methods of monitoring insulin-dependent glucose uptake in C2C12myotubes and propose this cell line to be a useful model for analyzing GLUT4 translocation in skeletal muscle.
Mechanism for Activation of Locomotor Centers in the Spinal Cord by Stimulation of the Mesencephalic Locomotor Region
Authors: Noga Brian R. , Kriellaars Dean J. , Brownstone Robert M. , Jordan Larry M.
Published: May 2006

The synaptic pathways of mesencephalic locomotor region (MLR)-evoked excitatory and inhibitory postsynaptic potentials (EPSPs and IPSPs) recorded from lumbar motoneurons of unanesthetized decerebrate cats during fictive locomotion were analyzed prior to, during, and after cold block of the medial reticular formation (MedRF) or the low thoracic ventral funiculus (VF). As others have shown, electrical stimulation of the MLR typically evoked short-latency excitatory or mixed excitatory/inhibitory PSPs in flexor and extensor motoneurons. The bulbospinal conduction velocities averaged ∼88 m/s (range: 62–145 m/s) and segmental latencies for EPSPs ranged from 1.2 to 10.9 ms. The histogram of segmental latencies showed three peaks, suggesting di-, tri-, and polysynaptic linkages. Segmental latencies for IPSPs suggested trisynaptic or polysynaptic transmission. Most EPSPs (69/77) were significantly larger during the depolarized phase of the intracellular locomotor drive potential (LDP), and most IPSPs (35/46) were larger during the corresponding hyperpolarized phase. Bilateral cooling of the MedRF reversibly abolished locomotion of both hindlimbs as measured from the electroneurogram (ENG) activity of muscle nerves and simultaneously abolished or diminished the motoneuron PSPs and LDPs. Unilateral cooling of the VF blocked locomotion ipsilaterally and diminished it contralaterally with concomitant loss or decrease the motoneuron PSPs and LDPs. Relative to the side of motoneuron recording, cooling of the ipsilateral VF sometimes uncovered longer-latency EPSPs, whereas cooling of the contralateral VF abolished longer-latency EPSPs. It is concluded that MLR stimulation activates a pathway that relays in the MedRF and descends bilaterally in the VF to contact spinal interneurons that project to motoneurons. Local segmental pathways that activate or inhibit motoneurons during MLR-evoked fictive locomotion appear to be both ipsilateral and contralateral.
Quantitative Assessment of the Timing and Tuning of Visual-Related, Saccade-Related, and Delay Period Activity in Primate Central Thalamus
Authors: Wyder Melanie T. , Massoglia Dino P. , Stanford Terrence R.
Published: May 2006

This study investigates the visuomotor properties of several nuclei within primate central thalamus. These nuclei, which might be considered components of an oculomotor thalamus (OcTh), are found within and at the borders of the internal medullary lamina. These nuclei have extensive anatomical links to numerous cortical and subcortical visuomotor areas including the frontal eye fields, supplementary eye fields, prefrontal cortex, posterior parietal cortex, caudate, and substantia nigra pars reticulata. Previous single-unit recordings have shown that neurons in OcTh respond during self-paced spontaneous saccades and to visual stimuli in the absence of any specific behavioral requirement, but a thorough account of the activity of these areas in association with voluntary, goal-directed movement is lacking. We recorded activity from single neurons in primate central thalamus during performance of a visually guided delayed saccade task. The sample consisted primarily of neurons from the centrolateral and paracentral intralaminar nuclei and paralaminar regions of the ventral anterior and ventral lateral nuclei. Neurons responsive to sensory, delay, and motor phases of the task were observed in each region, with many neurons modulated during multiple task periods. Across the population, variation in the quality and timing of saccade-contingent activity suggested participation in functions ranging from generating a saccade (presaccadic) to registering its consequences (e.g., efference copy). Finally, many neurons were found to carry spatial information during the delay period, suggesting a role for central thalamus in higher-order aspects of visuomotor control.
Functional Organization of Speed Tuned Neurons in Visual Area MT
Authors: Liu Jing , Newsome William T.
Published: May 2006

We analyzed the functional organization of speed tuned neurons in extrastriate visual area MT. We sought to determine whether neurons tuned for particular speeds are clustered spatially and whether such spatial clusters are elongated normal to the cortical surface so as to form speed columns. Our data showed that MT neurons are indeed clustered according to preferred speed. Multiunit recordings were speed tuned, and the speed tuning of these signals was well correlated with the speed tuning of single neurons recorded simultaneously. To determine whether speed columns exist in MT, we compared the rates at which preferred speed changed in electrode tracks that traversed MT obliquely and normally to the cortical surface. If speed columns exist, the preferred speed should change at a faster rate during oblique electrode tracks. We found, however, that preferred speed changed at similar rates for either type of penetration. In the same data set, the rate of change of preferred direction and preferred disparity differed substantially in normal and oblique penetrations as expected from the known columnar organization of MT. Thus our results suggest that a columnar organization for speed tuned neurons does not exist in MT.
Protein Kinase C Is Involved in Neurokinin Receptor Modulation of N- and L-Type Ca2+Channels in DRG Neurons of the Adult Rat
Authors: Sculptoreanu Adrian , de Groat William C.
Published: May 2006

Whole cell patch-clamp techniques were used to examine neurokinin receptor modulation of Ca2+channels in small to medium size dorsal root ganglia neurons (<40 pF) that express mainly N- and L-type Ca2+currents. Low concentrations of substance P enhanced Ca2+currents (5–40%, <0.2 μM), while higher concentrations applied cumulatively reversed these enhancements (5–28% reductions, >0.5 μM). This apparent inhibition by high concentrations of substance P was blocked by the administration of the NK3antagonist SB 235,375 (0.2 μM). The NK1agonist, [Sar9,Met11]-substance P (0.05 to 1.0 μM) did not alter Ca2+currents; whereas the NK2agonist, [βAla8]-neurokinin A (4–10), enhanced Ca2+currents (5–36% increase, 0.05–0.5 μM). The enhancement was reversed by the NK2antagonist MEN 10,376 (0.2 μM) but unaffected by the NK3antagonist SB 235,375 (0.2 μM). The NK3agonist [MePhe7]-neurokinin B (0.5–1.0 μM) inhibited Ca2+currents (6–24% decrease). This inhibition was not prevented by the NK2antagonist MEN 10,376 (0.2 μM) but was blocked by the NK3antagonist SB 235,375 (0.2 μM). Both the enhancement and inhibition of Ca2+currents by neurokinin agonists were reversed by the protein kinase C inhibitor bisindolylmaleimide I HCl (0.2–0.5 μM). Following inhibition of Ca2+channels by [MePhe7]-neurokinin the facilitatory effect of BayK 8644 (5 μM) was increased and the inhibitory effect of the N-type Ca2+channel blocker w -conotoxin GVIA (1 μM) was diminished, suggesting that the NK3agonist inhibits N-type Ca2+channels. Similarly, block of all but N-type Ca2+channels, revealed that [βAla8]-neurokinin A (4–10) enhanced the currents while [MePhe7]-neurokinin B inhibited the currents. Inhibition of all but L-type Ca2+channels, revealed that [βAla8]-neurokinin A (4–10) enhanced the currents while [MePhe7]-neurokinin B had no effect. Activation of protein kinase C with low concentrations of phorbol-12,13-dibutyrate enhanced Ca2+currents, but high concentrations inhibited N- and L-type Ca2+currents. In summary, these data suggest that in adult rat dorsal root ganglia neurons, NK2receptors enhance both L- and N-type Ca2+channels and NK3receptors inhibit N-type Ca2+channels and that these effects are mediated by protein kinase C phosphorylation of Ca2+channels.