bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glycation of CD59 impairs complement regulation on erythrocytes from diabetic subjects
Authors: Davies Catherine S. , Harris Claire L. , Morgan B. Paul 
Published: January 2005

SummaryType 1 diabetes is associated with anaemia. Although the underlying mechanisms remain unclear, the accompanying reticulocytosis implies that erythrocyte lifespan in the circulation is shortened. Among the factors that permit prolonged survival of erythrocytes are the membrane complement regulators. In conditions such as paroxysmal nocturnal haemoglobinuria, where erythrocyte expression of these regulators is reduced, erythrocyte survival is compromised and anaemia follows. Recent in vitro evidence indicates that one of the key membrane complement regulators, CD59, is inactivated by glycation in the presence of high concentrations of glucose or other glycating sugars. To ascertain whether glycation‐induced inactivation of CD59 occurrs in vivo we examined CD59 surface expression and function on erythrocytes from a cohort with poorly controlled type 1 diabetes (hyperglycaemic) and from matched normoglycaemic controls. Although expression of CD59, assessed using polyclonal anti‐CD59 antiserum, was similar in the two groups, erythrocytes from hyperglycaemic individuals were more susceptible to lysis by complement, entirely as a result of the loss of functional CD59. These data implicate glycation‐induced inactivation of CD59 as a factor contributing to anaemia in type 1 diabetes.
Interleukin‐24 and its receptors
Authors: Wang Mai , Liang Peng 
Published: January 2005

SummaryInterleukin 24 (IL‐24) is a new member of the IL‐10 family of cytokines and it signals through two heterodimeric receptors: IL‐20R1/IL‐20R2 and IL‐22R1/IL‐20R2. Upon binding to its receptors, IL‐24 induces rapid activation of Stat‐1 and Stat‐3 transcription factors, which appear to play a role in cell survival and proliferation. Under physiological conditions, the major sources of IL‐24 are the activated monocytes and T helper 2 cells, whereas the major IL‐24 target tissues, based on the receptor expression pattern, are non‐haematopoietic in origin, and include skin, lung and reproductive tissues. Structurally and functionally, IL‐24 is highly conserved across species. This review highlights our current knowledge of IL‐24 as a cytokine, with much less emphasis placed on the non‐receptor‐mediated functions (a subject of several reviews) focused on in much of the earlier literature on IL‐24. The potential roles of IL‐24 as part of a complex cytokine network in wound healing, psoriasis and cancer are discussed.
Expression and possible functions of DNA lesion bypass proteins in spermatogenesis
Authors: VAN DER LAAN ROALD , BAARENDS WILLY M. , WASSENAAR EVELYNE , ROEST HENK P. , HOEIJMAKERS JAN H. J. , GROOTEGOED J. ANTON 
Published: January 2005

SummaryIn mammalian cells, there is a complex interplay of different DNA damage response and repair mechanisms. Several observations suggest that, in particular in gametogenesis, proteins involved in DNA repair play an intricate role in and outside the context of DNA repair. Here, we discuss the possible roles of proteins that take part in replicative damage bypass (RDB) mechanisms, also known as post‐replication DNA repair (PRR), in germ line development. In yeast, and probably also in mammalian somatic cells, RDB [two subpathways: damage avoidance and translesion synthesis (TLS)] prevents cessation of replication forks during the S phase of the cell cycle, in situations when the replication machinery encounters a lesion present in the template DNA. Many genes encoding proteins involved in RDB show an increased expression in testis, in particular in meiotic and post‐meiotic spermatogenic cells. Several RDB proteins take part in protein ubiquitination, and we address relevant aspects of the ubiquitin system in spermatogenesis. RDB proteins might be required for damage avoidance and TLS of spontaneous DNA damage during gametogenesis. In addition, we consider the possible functional relation between TLS and the induction of mutations in spermatogenesis. TLS requires the activity of highly specialized polymerases, and is an error‐prone process that may induce mutations. In evolutionary terms, controlled generation of a limited number of mutations in gametogenesis might provide a mechanism for evolvability.
Seminal Factor VIII and von Willebrand Factor: a possible role of the conventional clotting system in human semen?
Authors: LWALEED BASHIR A. , GREENFIELD ROBERT , ROYLE ERIC , Birch Brian , Cooper Alan J. 
Published: January 2005

SummaryFactor (F) VIII circulates in blood complexed with von Willebrand Factor (vWF). Deficiency or defect accounts for haemophilia A and vWF disease. In blood, FVIII functions as a co‐factor for FIXa in the activation of FX. Human semen coagulates and liquefies in a process that resembles and has some links with the conventional haemostatic process. A study elsewhere has detected traces, but not measurable levels, of FVIII coagulant activity (FVIII:C). In the present study we have assessed FVIII antigen (FVIII:Ag), FVIII:C and vWF antigen (vWF:Ag) levels in 159 semen specimens obtained from sub‐fertile (n = 21), normally fertile (n = 38), fertile donors (n = 32), and vasectomized men (n = 57). Seminal FVIII:Ag levels were also measured in a group defined by several parameters derived from the World Health Organization (WHO) fertility criteria, termed ‘pooled normal semen parameters’ (PNSP). Factor VIII:Ag levels were compared with conventional fertility parameters. In addition, both FVIII:C and vWF:Ag were assessed in a separate group of normal individuals (n = 11). Factor VIII:Ag, FVIII:C and vWF were present and quantifiable in human semen. Factor VIII:Ag levels were significantly lower in vasectomy subjects compared with donors (p = 0.01) or PNSP group (p = 0.01). Several trends taken together suggest an associations between FVIII:Ag and semen quality. Parallel investigations demonstrate FV, FVII, FVIIa, FIX, FIXa, FXa, FXI, FXII, tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in semen. The present report therefore provides further evidence for the presence of a functioning clotting system in human semen.
Intracerebroventricular Injections of Prolactin Counteract the Antagonistic Effect of Bromocriptine on Rabbit Maternal Behaviour
Authors: González‐Mariscal G. , Chirino R. , Flores‐Alonso J. C. , Rosenblatt J. S. , Beyer Carlos 
Published: January 2005

AbstractTo investigate the participation of prolactin in nest‐building and maternal behaviour in rabbits, we administered (from pregnancy day 26 to parturition) rabbit prolactin (rbPRL; or vehicle) intracerebroventricularly (i.c.v.) to primiparous animals injected with bromocriptine subcutaneously (s.c.). Control females (given vehicle s.c. and i.c.v.) built a maternal nest (of straw and body hair) in 77% of cases. This proportion decreased to 19% in the bromocriptine‐only group (P < 0.05) and increased to 93% in the group given bromocriptine plus rbPRL (P > 0.05). Maternal behaviour (i.e. the adoption of a crouching posture over the litter inside the nest box) was expressed by 77% of control rabbits, 19% of bromocriptine‐only animals (P < 0.05) and 57% of females given bromocriptine plus rbPRL (P > 0.05). Values of nonmaternal activities (i.e. scent‐marking, ambulation in an open field) were similar among the three studied groups. These results suggest that prolactin, acting in late pregnancy, plays a major role in the stimulation of nest‐building and maternal behaviour in rabbits.
Plasma and Hypothalamic Peptide‐Hormone Levels Regulating Somatotroph Function and Energy Balance in Fed and Fasted States: A Comparative Study in Four Strains of Rats
Authors: Kappeler L. , Zizzari P. , Grouselle D. , Epelbaum J. , Bluet‐Pajot M. T. 
Published: January 2005

AbstractBoth growth hormone (GH)/insulin growth factor (IGF)‐1 axis and energy balance have been implicated in longevity independently. The aim of the present study was to characterize the effect of a 72‐h fasting period at 3 months of age in four different rat strains: (i) Wistar and (ii) Fischer 344 rats, which develop obesity with age, and (iii) Brown Norway and (iv) Lou C rats, which do not. Wistar rats ate more, were significantly bigger, and presented with higher plasma leptin and lower ghrelin levels and hypothalamic growth hormone‐releasing hormone (GHRH) content than rats from the three other strains. Plasma insulin and IGF‐1 levels were lower in Brown Norway and Lou C rats, and somatostatin content was lower in Brown Norway rats only. Glycaemia was lower in Lou C rats that displayed a lower relative food intake compared to Fischer and Wistar rats. Brown Norway rats showed a greater caloric efficiency than the three other strains. Concerning major hypothalamic neuropeptides implicated in feeding, similar amounts were detected in the four strains for neuropeptide Y, agouti‐related peptide, galanin, melanin‐concentrating hormone, α‐melanocortin‐stimulating hormone (α‐MSH) and corticotropin‐releasing hormone. Orexin A appeared to be slightly elevated in Fischer rats and cocaine amphetamine‐regulated transcript (CART)55−102 diminished in Brown Norway. At the mRNA level, orexin A, GHSR1, α‐MSH and CART expression were higher in Wistar and Lou C rats. Principal component analysis confirmed the presence of two main factors in the ad libitum rat population; the first being associated with growth‐related parameters and the second being associated with food intake regulation. Hypothalamic GHRH and somatostatin content were positively correlated with feeding‐related neuropeptides such as α‐MSH for GHRH, and orexin A and CART for both peptides. Plasma ghrelin levels were negatively correlated with leptin and IGF‐1 levels. Finally, a 72‐h fasting period affected minimally body weight, plasma IGF‐1 and leptin levels in Lou C rats compared to the three other strains, and plasma insulin levels were less affected in Brown Norway rats. In conclusion, Wistar shorter life span is consistent with its already fatter phenotype at 3 months of age. In terms of IGF‐1, glycaemia and leptin responses to fasting, the Lou strain, which presents with a low food intake/body weight and caloric efficiency, is the least affected. The link between food intake regulation, GH axis and ageing is further demonstrated by principal component analysis, where GHRH and somatostatin were found to be strongly associated with energy homeostasis parameters.
Sensitization of mesenteric afferents to chemical and mechanical stimuli following systemic bacterial lipopolysaccharide
Authors: Liu C.‐Y. , Jiang W. , Müller M. H. , Grundy D. , Kreis M. E. 
Published: January 2005

Abstract  Background:  The mechanisms underlying endotoxin‐induced hyperalgesia remain unknown. We aimed to study the mechanisms underlying the sensitizing action of lipopolysaccharide (LPS) on intestinal afferent responses to mechanical and chemical stimuli.Methods:  Extracellular recordings of jejunal afferent nerve discharge were obtained from pentobarbitone‐anaesthetized rats.Results:  Lipopolysaccharide (6 mg kg−1, i.v.) stimulated a short‐term, transient (<30 min) increase in chemosensitivity to systemic 5‐HT (6 μg kg−1) and responses to mechanical distension and a delayed but maintained (>30 min) increase in spontaneous afferent discharge. Naproxen (10 mg kg−1) and the prostaglandin receptor antagonist AH6809 (1 mg kg−1) significantly attenuated both the short‐term sensitization to mechanical distension and 5‐HT and the long‐term increase in baseline afferent firing following LPS. In contrast, the iNOS inhibitor aminoguanidine (15 mg kg−1) and the L‐type calcium channel antagonist nifedipine (1 mg kg−1) both prolonged the period of afferent sensitization to distension and 5‐HT without influencing the augmented baseline‐firing rate. ω‐Conotoxin GVIA attenuated the increase in afferent discharge to LPS, without any change in mechano‐ and chemosensitivity.Conclusions:  The long‐term (>30 min) increase in afferent firing following systemic LPS involves neurogenic release of prostanoids. The short‐term (<30 min) sensitization also appears to depend on prostanoid release, while nitric oxide production may serve to down‐regulate LPS‐induced afferent hypersensitivity.
Effects of the selective serotonin reuptake inhibitor, fluoxetine, on regional gastric contractility1
Authors: James A. N. , Ryan J. P. , Parkman H. P. 
Published: January 2005

Abstract  Selective serotonin reuptake inhibitors (SSRIs) are increasingly used to treat a variety of disorders but have gastrointestinal side‐effects.Aim:  To determine the effects of the SSRI, fluoxetine, on gastric smooth muscle contractility.Methods:  Fundic, antral, and pyloric circular muscle contractility of guinea pig muscle strips were measured in vitro. Fluoxetine was added in concentrations from 0.1 nmol L−1 to 100 μmol L−1. Receptor antagonists were used to determine the neural pathways involved.Results:  Fluoxetine caused concentration dependent contractions, which were greatest in fundus compared with the antrum or pylorus. The contractile effects of fluoxetine in the antrum were reduced by tetrodotoxin, atropine, phentolamine, and the 5‐HT4 receptor antagonist GR 113808. The contractile effects of fluoxetine in the fundus were reduced by atropine, phentolamine, and GR 113808.Conclusions:  Fluoxetine affects gastric contractility with regional variability – contracting the fundus more than the antrum or pylorus. The fluoxetine contractile effect is reduced by tetrodotoxin, atropine, phentolamine, and a 5‐HT4 receptor antagonist. These results suggest fluoxetine interacts with muscarinic, alpha‐adrenergic, and serotoninergic receptors and/or ongoing reuptake/release of serotonin in the stomach.
Circumnutation of rice coleoptiles: its occurrence, regulation by phytochrome, and relationship with gravitropism
Authors: YOSHIHARA TAKESHI , IINO MORITOSHI 
Published: January 2005

ABSTRACTIt has been found that coleoptiles of dark‐grown rice (Oryza sativa L.) seedlings undergo regular circumnutation in circular orbits with periods of about 180 min. Both clockwise and counter‐clockwise movements were observed, but individual coleoptiles continued to rotate only in one direction. Light‐grown seedlings did not show circumnutation. In fact, dark‐grown seedlings were found to cease circumnutating in response to a pulse of red light (R). This light‐induced inhibition of circumnutation was demonstrated to involve both a FR‐inducible very‐low‐fluence response, solely mediated by phytochrome A, and a FR‐reversible low‐fluence response, mediated by phytochrome B and/or C. The R‐induced inhibition of circumnutation showed temporal agreement with the R‐induced inhibition of coleoptile growth, suggesting that the former results from the latter. However, about 25% of growth activity remained after R treatment, indicating that circumnutation is more specifically regulated by phytochrome. The R‐treated coleoptile showed gravitropism. Investigation of the growth differential for gravitropic curvature revealed that gravitropic responsiveness was rather enhanced by R. The results suggested that gravitropism is not a cause of circumnutation. It remained probable, however, that gravity perception is a part of the mechanism of circumnutation. It is speculated that the circumnutation investigated aids the seedling shoot in growing through the soil.
OsAGAP, an ARF‐GAP from rice, regulates root development mediated by auxin in Arabidopsis
Authors: ZHUANG X. , XU Y. , CHONG K. , LAN L. , XUE Y. , XU Z. 
Published: January 2005

ABSTRACTArf (ADP‐ribosylation factor) proteins, which mediate vesicular transport, have little or no intrinsic GTPase activity. They rely on the action of GTPase‐activating proteins (GAPs) and guanine nucleotide exchange factors (GEFs) for their function. In the present study the OsAGAP gene in rice, which encoded a protein with predicted structure similar to ArfGAP, was identified. The purified OsAGAP‐GST fusion protein was able to stimulate the GTPase activity of rice Arf. Furthermore, OsAGAP can rescue the defect of vesicular transport in the yeast gcs1Δglo3Δ double‐mutant cells. Transgenic Arabidopsis with OsAGAP constitutively expression showed reduced apical dominance, shorter primary roots, increasing number of longer adventitious roots. Many of the phenotypes can be phenocopied by treatment of exogenous indoleacetic acid level (IAA) in wild‐type plants. Determination of whole‐plant IAA level showed that there is a sharp increase of free IAA in OsAGAP transgenic Arabidopsis seedlings. In addition, removal of the 4‐day‐old shoot apex could inhibit the adventitious root formation in the transgenic seedlings. These results suggest OsAGAP, an ARF‐GAP of rice, may be involved in the mediation of plant root development by regulating auxin level.
Within‐stem oxygen concentration and sap flow in four temperate tree species: does long‐lived xylem parenchyma experience hypoxia?
Authors: SPICER R. , HOLBROOK N. M. 
Published: January 2005

ABSTRACTOxygen levels as low as 1–5% (gaseous mole fraction) occur in secondary xylem, but it is not known if there is a consistent pattern of decline in O2 from the cambium toward the pith, or whether parenchyma cells experience hypoxic conditions deep within the stem. We developed a system for repeated in situ measurement of O2 at different depths within stems of Acer rubrum, Fraxinus americana, Tsuga canadensis, and Quercus rubra. In summer during active transpiration, O2 declined from the cambium toward the heartwood boundary in F. americana, T. canadensis and Q. rubra, but remained constant in A. rubrum. Average sapwood O2 was about 10%, with the lowest values observed in the innermost sapwood around 3–5%. Before spring leaf flush, O2 content in the outer sapwood was reduced in Q. rubra and T. canadensis relative to summer, and was occasionally lower than in the inner sapwood. Sapwood respiration in T. canadensis was constant above 5% O2, but reduced by about 65% at 1% O2. In F. americana, sapwood respiration was constant above 10% O2 but reduced by 25% at 5% O2, and by 75% at 1% O2, the most extreme inhibition observed. However, when prolonged (72 h) exposure to 1%, 5% and 10% O2 was followed by re‐equilibration to 10% O2, no inhibition was found. Given the minor (and reversible) effect of low O2 on parenchyma metabolism at levels common in the inner sapwood, it is unlikely that O2 content severely limits parenchyma respiration or leads to parenchyma cell death during sapwood senescence. Within‐stem O2 levels may instead be most relevant to metabolism in the cambial zone and phloem, for which sapwood could serve as a significant source of O2.
Salt‐stress signalling and the role of calcium in the regulation of the Arabidopsis ATHB7 gene
Authors: HENRIKSSON E. , NORDIN HENRIKSSON K. 
Published: January 2005

ABSTRACTIn plants changes in cytosolic calcium ion concentrations ([Ca2+]cyt) have been detected after various stress treatments, including salt treatment. The involvement of a Ca2+ signal as an essential component of signalling pathways leading to downstream responses, such as gene expression, is supported only by a few studies. In this study the possible involvement of the salt stress‐induced increase in [Ca2+]cyt in the signalling pathway leading to the induction of ATHB7, a homeobox gene encoding a homeodomain leucine zipper (HDZip) transcription factor was analysed. The salt‐induced expression of ATHB7 was found to be independent of the Ca2+ signal evoked by salt. Instead, it was found that ATHB7 expression in shoots was not dependent on a direct contact with salt or osmoticum, whereas in roots, ATHB7 seemed to be induced by the direct contact, indicating that signals from roots cause systemic induction of ATHB7. Abscisic acid (ABA) or ABA‐dependent components were found to, at least partly, to function as the systemic signal.
Up‐regulation of a photosystem II core protein phosphatase inhibitor and sustained D1 phosphorylation in zeaxanthin‐retaining, photoinhibited needles of overwintering Douglas fir
Authors: EBBERT V. , ADAMS III W. W. , MATTOO A. K. , SOKOLENKO A. , DEMMIG‐ADAMS B. 
Published: January 2005

ABSTRACTOverwintering needles of the evergreen conifer Douglas fir exhibited an association between arrest of the xanthophyll cycle in the dissipating state (as zeaxanthin +  antheraxanthin; Z + A) with a strongly elevated predawn phosphorylation state of the D1 protein of the photosystem II (PSII) core. Furthermore, the high predawn phosphorylation state of PSII core proteins was associated with strongly increased levels of TLP40, the cyclophilin‐like inhibitor of PSII core protein phosphatase, in winter versus summer. In turn, decreases in predawn PSII efficiency, Fv/Fm, in winter were positively correlated with pronounced decreases in the non‐phosphorylated form of D1. In contrast to PSII core proteins, the light‐harvesting complex of photosystem II (LHCII) did not exhibit any nocturnally sustained phosphorylation. The total level of the D1 protein was found to be the same in summer and winter in Douglas fir when proteins were extracted in a single step from whole needles. In contrast, total D1 protein levels were lower in thylakoid preparations of overwintering needles versus needles collected in summer, indicating that D1 was lost during thylakoid preparation from overwintering Douglas fir needles. In contrast to total D1, the ratio of phosphorylated to non‐phosphorylated D1 as well as the levels of the PsbS protein were similar in thylakoid versus whole needle preparations. The level of the PsbS protein, that is required for pH‐dependent thermal dissipation, exhibited an increase in winter, whereas LHCII levels remained unchanged.
Genetic diversity for drought resistance in wild emmer wheat and its ecogeographical associations
Authors: PELEG Z. , FAHIMA T. , ABBO S. , KRUGMAN T. , NEVO E. , YAKIR D. , SARANGA Y. 
Published: January 2005

ABSTRACTWild emmer wheat (Triticum turgidum spp. dicoccoides (Körn.) Thell.), the tetraploid progenitor of cultivated wheat, is a potential source for various agronomical traits, including drought resistance. The objectives of this study were to characterize (1) the genetic diversity for drought resistance in wild emmer wheat, and (2) the relationship between drought responses of the wild emmer germplasm and the ecogeographical parameters of its collection sites. A total of 110 wild emmer accessions consisting of 25 populations and three control durum wheat cultivars were examined under two irrigation regimes, well‐watered (’wet’) and water‐limited (’dry’). Wide genetic diversity was found both between and within the wild emmer populations in most variables under each treatment. A considerable number of the wild emmer accessions exhibited an advantage in productivity (spike and total dry matter) over their cultivated counterparts. Most wild emmer wheat accessions exhibited a greater carbon isotope ratio (δ13C, indicating higher water‐use efficiency) under the dry treatment and higher plasticity of δ13C relative to the cultivated controls, which may have contributed to the drought adaptations in the former. The most outstanding drought‐tolerance capacity (in term of productivity under the dry treatment and susceptibility indices) was detected in wild emmer populations originated from hot dry locations. The results suggest that wild emmer has the potential to improve drought resistance in cultivated wheat.