bluuebunny/crossref_metadata_2025_split huggingface dataset:
Species richness of phytophagous beetles in the tropical tree Brosimum utile (Moraceae): the effects of sampling strategy and the problem of tourists
Authors: Ødegaard F. 
Published: February 2004

Abstract.  1. Phytophagous beetles on six mature living trees and two dead trees of Brosimum utile (Moraceae) were surveyed during 1 year in a tropical wet forest in Panama. The dead trees were surveyed both as suspended in the canopy and after falling down to the understorey.2. Canopy access was provided by a construction crane and sampling was performed by beating and hand‐collecting. The same amount of time was spent on each tree in order to standardise sampling effort. A list of all species associated with the tree is presented.3. A total of 3009 individuals representing 364 species were collected. Tourists were excluded from the analyses by recording host associations directly and by probability assessments of host associations based on abundance categories. A total of 2603 individuals and 244 species were associated with the tree. The proportion of tourists in the trees increased with sample size.4. A single mature living tree had on average 58.5 ± 6.5 species. The local species richness of B. utile was estimated as 2.5 times higher than in a single mature tree; however, a substantial increase in species richness was attained when dead wood habitats were included. Saproxylic species made up 82% of the total material.5. The investigated habitat types of B. utile constituted distinct, complementary species assemblages. Similarity between saproxylic species of dead suspended wood and dead understorey wood of the same tree was 0.2 (Morisita–Horn index), confirming a prominent vertical stratification among this guild.
Host plants and butterfly biology. Do host‐plant strategies drive butterfly status?
Authors: Dennis Roger L. H. , Hodgson John G. , Grenyer Richard , Shreeve Tim G. , Roy David B. 
Published: February 2004

Abstract. 1. To determine whether rarity and decline is linked to organism ecology, associations have been examined between butterfly larval host‐plant competitive, stress‐tolerant, ruderal (C‐S‐R) strategies and butterfly biology.2. Associations have been sought between meanC‐S‐Rscores for larval host plants with butterfly life history, morphology and physiology variables, resource use, population attributes, geography, and conservation status. Comparisons are carried out across species and controlled for phylogenetic patterning.3. Butterfly biology is linked to host‐plant strategies. An increasing tendency of a butterfly's host plants to a particular strategy biases that butterfly species to functionally linked life‐history attributes and resource breadth and type. In turn, population attributes and geography are significantly and substantially affected by host choice and the strategies of these host plants.4. The greatest contrast is between butterfly species whose host plants are labelledCandRstrategists and those whose host plants are labelledSstrategists. Increasingly high host‐plantCandRstrategy scores bias butterflies to rapid development, short early stages, multivoltinism, long flight periods, early seasonal emergence, higher mobility, polyphagy, wide resource availability and biotope occupancy, open, areally expansive, patchy population structures, denser distributions, wider geographical ranges, resistance to range retractions as well as to increasing rarity in the face of environmental changes. Increasing host‐plantSstrategy scores have reversed tendencies, biasing those butterfly species to extended development times, fewer broods, short flight periods, smaller wing expanse and lower mobility, monophagy, restricted resource exploitation and biotope occupancy, closed, areally limited populations with typical metapopulation structures, sparse distributions, and limited geographical ranges, range retractions, and increased rarity.5. Species withSstrategy host plants are species vulnerable to current environmental changes and species of conservation concern.
Linking the bacterial community in pea aphids with host‐plant use and natural enemy resistance
Authors: Ferrari Julia , Darby Alistair C. , Daniell Tim J. , Godfray H. Charles J. , Douglas Angela E. 
Published: February 2004

Abstract.  1. Pea aphids, Acyrthosiphon pisum, harbour a range of facultative accessory bacteria (secondary symbionts), including those informally known as PASS (R‐type), PAR, PABS (T‐type), and PAUS (U‐type).2. To explore the relationship between possession of these bacteria and ecologically important traits of A. pisum, correlations between the accessory bacteria found in 47 parthenogenetic clones of A. pisum and the host plant on which each clone was collected and its susceptibility to natural enemies were surveyed.3. The bacterial complement varied with plant of collection. PAUS (U) was present in all of 12 clones affiliated to Trifolium but was otherwise rare, while PABS (T) and PASS (R) occurred at significantly higher frequency in clones from Lotus and Vicia, respectively, than clones from other plants.4. Possession of PABS (T) was associated strongly with resistance to the parasitoid Aphidius eadyi and weakly with resistance to Aphidius ervi. Aphids carrying PAUS (U) were more resistant to the fungal pathogen Pandora (Erynia) neoaphidis, although this correlation was complicated by a strong association with host‐plant use.
Genetic deficiency of CD16, the low‐affinity receptor for immunoglobulin G, has no impact on the functional capacity of polymorphonuclear neutrophils
Authors: Wagner C. , Hänsch G. M. 
Published: February 2004

AbstractBackground  Of the three receptors for immunoglobulin G (IgG), the low‐affinity receptor CD16 is constitutively expressed on polymorphonuclear neutrophils (PMNs), monocytes and NK‐cells. CD16 participates in various effector functions, notably phagocytosis of opsonized particles or of immune complexes, and in antibody‐dependent cellular cytotoxicity (ADCC). In the present study we report a case of total CD16 deficiency on PMNs and monocytes.Design  Polymorphonuclear neutrophils, monocytes and NK‐cells were analyzed for surface‐receptor expression by cytofluorometry and laser scan microscopy. Moreover, CD16‐specific mRNA was assessed by RT‐PCR. As functional parameters, phagocytosis of opsonized bacteria was tested, as was superoxide production.Results  Polymorphonuclear neutrophils and monocytes totally deficient in CD16 were detected by chance in an apparently healthy individual. Further analysis revealed that two more members of his family, his father and sister, were also deficient in CD16. All were healthy and there was no evidence of an increased frequency, or of exceptionally severe or persistent infections. Despite the lack of CD16, phagocytosis of antibody‐coated bacteria was within the normal range, as was the superoxide production.Conclusion  Deficiency of CD16 does not compromise the host defence. Apparently, the other receptors for IgG, CD32 and CD64, can compensate for the lack of CD16.
Characterization of the human skeletal muscle glycogen synthase gene (GYS1) promoter
Authors: Fredriksson J. , Ridderstråle M. , Groop L. , Orho‐Melander M. 
Published: February 2004

AbstractBackground  Impaired activation of the human skeletal muscle glycogen synthase by insulin is typical for type 2 diabetic patients. Regulation of glycogen synthase occurs mainly by phosphorylation/dephoshorylation but little is known whether there also is transcriptional regulation. Therefore we studied transcriptional regulation of the human skeletal muscle glycogen synthase gene (GYS1) and evaluated the effects of insulin and forskolin on the promoter activity.Methods  Seven promoter fragments were expressed in C2C12 myoblasts and myotubes and in HEK293 cells, and the luciferase assay was used to determine transcriptional activity.Results  The highest luciferase activity, 350‐fold of the promoterless vector, was obtained with nucleotides −692 to +59 in myotubes (P < 0·001), while the nucleotides −250 to +59 provided the highest, 45‐fold, activity in the HEK293 cells (P < 0·001). Longer promoter constructs (nucleotides −971, −1707 and −2158 to +59, respectively) had low promoter activity in both cell types. Forskolin treatment for 24 h resulted in approximately 30% decreased promoter activity in myotubes (P < 0·05). Insulin treatment for 0·5–3 h did not increase GYS1 promoter activity; instead the activity was slightly but significantly decreased after 24 h in myotubes (P < 0·005).Conclusions  From our results we conclude that basal GYS1 promoter activity is obtained from the first 250 nucleotides of the promoter, while the nucleotides −692 to −544 seem to be responsible for muscle‐specific expression, and nucleotides −971 to −692 for negative regulation. In myotubes, the GYS1 promoter was sensitive to negative regulation by forskolin, whereas insulin did not increase GYS1 transcription.
Fractal analysis of bone texture: a screening tool for stress fracture risk?
Authors: Prouteau S. , Ducher G. , Nanyan P. , Lemineur G. , Benhamou L. , Courteix D. 
Published: February 2004

AbstractBackground  The aim of this study was to identify specific bone characteristics of stress fracture (SF) cases in sportswomen. To date, no tool is able to distinguish individuals who are at risk, limiting preventive measures.Material and methods  We investigated the skeletal system of sportswomen who did sustain SF in the past (n = 19) and compared it with that of female controls (C) with a similar sporting history but without any fracture history (n = 20).Bone mass and body composition were measured using dual‐energy X‐ray absorptiometry. Bone micro‐architecture was investigated by calcaneal ultrasound and fractal analysis of calcaneus radiographic images. Oestradiol levels were measured by E.I.A, and IGF‐1 by R.I.A. Menstrual characteristics, nutrient intake, and training were assessed using questionnaires.Results  The result of the fractal analysis, expressed by the Hmean parameter, was significantly lower in the SF group, reflecting a more complex structure of the trabecular micro‐architectural organization (P < 0·005). Body mass index (BMI) at birth was also found to be lower in the SF cases as compared with their C (P < 0·03).Multivariate analysis revealed that the fractal parameter Hmean, bone mineral content (BMC) at Ward's triangle and the BMI at birth correctly assigned 84·85% of the female athletes into their respective SF or C groups (P = 0·001).Conclusion  These results suggest that the fractal parameter and the BMI at birth may be able to identify female athletes most at risk for this overuse bone injury, as their low indexes might reflect a greater skeletal sensitivity.
Brain natriuretic peptide in the prediction of recurrence of angina pectoris
Authors: Takase H. , Toriyama T. , Sugiura T. , Ueda R. , Dohi Y. 
Published: February 2004

AbstractBackground  Circulating levels of brain natriuretic peptide (BNP) provide prognostic information for patients with heart failure, but little is known about its prognostic usefulness in patients with stable angina pectoris. We investigated whether BNP could be used as a marker for the prediction of anginal recurrence after successful treatment.Design  Brain natriuretic peptide levels of 77 patients with stable angina pectoris were measured at enrolment and after confirmation of successful treatment (i.e. no anginal attack for at least 6 months: chronic phase) with percutaneous transluminal coronary angioplasty and/or conventional medication. Then, we prospectively followed them up for 25·9 ± 1·4 months, with the endpoint being a recurrence of anginal attacks.Results  An anginal attack recurred in seven patients. In patients without recurrence, BNP levels in the chronic phase (21 ± 12 [median ± median absolute deviation] pg mL−1) were lower than those measured at enrolment (46 ± 25 pg mL−1, P < 0·0001), whereas the levels in patients with recurrence increased during the same period (from 36 ± 16 to 72 ± 42 pg mL−1, P < 0·05). A univariate analysis revealed that the BNP level measured in the chronic phase was the significant predictor of future anginal recurrence. Analysis of the receiver operating characteristic curve indicated that the cutoff level of BNP in the chronic phase was 68 pg mL−1. The Kaplan‐Meier method revealed that the incidence of anginal recurrence was higher in patients with higher (71·4%) than lower levels of BNP (2·9%; P < 0·0001).Conclusions  Measurement of BNP levels after successful therapy is clinically useful for the prediction of recurrence of anginal attacks in patients with angina pectoris.
Mechanical stretch induces TGF‐β synthesis in hepatic stellate cells
Authors: Sakata R. , Ueno T. , Nakamura T. , Ueno H. , Sata M. 
Published: February 2004

AbstractBackground  It is known that mechanical stress induces extracellular matrix via transforming growth factor‐β (TGF‐β) synthesis in vascular smooth muscle cells. Activated hepatic stellate cells (HSCs) are an important source of TGF‐β in the liver. However, it remains unclear whether mechanical stress induces TGF‐β in HSCs. The Rho small GTP‐binding protein (Rho) has recently emerged as an important regulator of actin and cytoskeleton. We examined whether TGF‐β is expressed in stretched HSCs and whether Rho is involved in stretch‐induced TGF‐β synthesis.Materials and methods  A cultured human HSC cell line, LI90, was used for this study. Hepatic stellate cells were cyclically stretched using the Flexercell® strain unit. Concentration of TGF‐β in the conditioned medium was estimated by a bioassay using mink lung epithelial cells transfected with a plasminogen activator inhibitor‐1 promoter‐luciferase construct. Transforming growth factor‐β mRNA expression of HSCs was estimated by a reverse‐transcription polymerase chain reaction. Replication‐defective adenoviral vectors expressing a dominant negative type of Rho was utilized to suppress its effect on HSCs.Results  Transforming growth factor‐β concentration of the conditioned media of stretched HSCs showed time‐dependent increases as compared to nonstretched HSCs from 2 h to 24 h. Transforming growth factor‐β mRNA expression in stretched HSCs was increased compared with that in nonstretched HSCs. Transfection of dominant negative Rho inhibited the stretch‐induced TGF‐β synthesis.Conclusions  Mechanical stretch enhanced TGF‐β expression on mRNA and protein level in HSCs. Rho was closely related to stretch‐induced TGF‐β synthesis in HSCs.
Toll‐like receptor‐4 Asp299Gly polymorphism does not influence progression of atherosclerosis in patients with familial hypercholesterolaemia
Authors: Netea M. G. , Hijmans A. , Van Wissen S. , Smilde T. J. , Trip M. D. , Kullberg B. J. , De Boo T. , Van der Meer J. W. M. , Kastelein J. J. P. , Stalenhorf A. F. H. 
Published: February 2004

AbstractBackground  Toll‐like receptor‐4 (TLR4) is a major receptor for inflammatory stimuli potentially involved in the pathogenesis of atherosclerosis, such as lipopolysaccharide (LPS) and heat‐shock proteins. The Asp299Gly polymorphism of the TLR4 gene has been associated with a reduced intima‐media thickness (IMT) of the common carotid artery in healthy individuals. We have investigated whether the presence of the Asp299Gly polymorphism in patients with familial hypercholesterolaemia (FH) has a similar protective effect, and whether it influences the effects of HMG‐CoA reductase treatment.Materials and methods  A cohort of 293 FH patients and 200 healthy volunteers were genotyped for the presence of the Asp299Gly allele using polymerase chain reaction followed by restriction fragment length polymorphism analysis. Intima‐media thickness measurements, inflammatory parameters and the effect of HMG‐CoA reductase inhibitors were compared between the patients with and without Asp299Gly allele.Results  The Asp299Gly allele was present in 10·6% of the FH patients and 11·0% of the healthy individuals. Whereas the FH patients carrying the Asp299Gly allele displayed a reduced absolute IMT value compared with the FH patients carrying the wild‐type allelle, the difference did not reach statistical significance. In addition, the effect of treatment with HMG‐CoA reductase inhibitors was not influenced by the presence of Asp299Gly allele.Conclusion  The presence of the Asp299Gly allele of the TLR4 gene does not seem to exert a major influence on the progression of atherosclerosis in patients with FH.
Protein kinase C and extracellular signal regulated kinase are involved in cardiac hypertrophy of rats with progressive renal injury
Authors: Takahashi H. , Takeishi Y. , Miyamoto T. , Shishido T. , Arimoto T. , Konta T. , Miyashita T. , Ito M. , Kubota I. 
Published: February 2004

AbstractIncreased cardiovascular mortality is an unresolved problem in patients with chronic renal failure. Cardiac hypertrophy is observed in the majority of patients with chronic renal failure undergoing haemodialysis. However, the mechanisms, including signal transduction pathways, responsible for cardiac hypertrophy in renal failure remain unknown. We examined the subcellular localization of protein kinase C (PKC) isoforms and phosphorylation activities of 3 mitogen‐activated protein (MAP) kinase families in hypertrophied hearts of progressive renal injury rat model by subtotal nephrectomy (SNx). We also examined the effects of a novel angiotensin II type‐1 receptor antagonist, CS‐866, on the PKC translocation, MAP kinase activity and cardiac hypertrophy in SNx rats. The left ventricle/body weight ratios were significantly larger in SNx rats than in sham rats at 1, 2, and 4 weeks after surgery. The translocation of PKCα and ɛ isoforms to membranous fraction was observed in SNx rat hearts at 1, 2, and 4 weeks after surgery. Activation of extracellular signal regulated kinase (ERK) 1/2, but not p38 MAP kinase and c‐Jun N‐terminal kinase (JNK), was observed at 1 and 2 weeks after surgery. Angiotensin II receptor blockade with CS‐866 (1 mg kg−1 day−1) prevented cardiac hypertrophy, PKC translocation and ERK1/2 activation in SNx rats without significant changes in blood pressure. These data suggest that PKC and ERK1/2 are activated by an angiotensin II receptor‐mediated pathway and might play an important role in the progression of cardiac hypertrophy in renal failure.
Cerebral oximetry in patients with sickle cell disease
Authors: Nahavandi M. , Tavakkoli F. , Hasan S. P. , Wyche M. Q. , Castro O. 
Published: February 2004

AbstractBackground  There is limited information concerning the brain's oxygen supply and demand in patients with sickle cell disease.Design  We measured near‐infrared spectroscopy of brain oxygenation in 27 patients with sickle cell disease regardless of vaso‐occlusive crisis, 14 normal healthy controls, and five anaemic patients without sickle cell disease. We also measured pre‐ and post‐transfusion cerebral oximetry in 14 additional sickle cell disease patients who were on transfusion programmes.Results  The mean cerebral oxygen saturation in the combined steady‐state and vaso‐occlusive crisis population was found to be significantly lower than that in the controls and in anaemic patients without sickle cell disease (47·7% vs. 61·3%, 59·8%, P < 0·0001). Cerebral oxygen saturation failed to correlate with the haemoglobin concentration (r = 0·51, P > 0·5). However, cerebral oxygen saturation increased from 40·4% to 49·6% (P = 0·01) and correlated significantly with the haemoglobin level (r = 0·553, P = 0·003) in 14 subjects studied before and after transfusions. In seven subjects who received simple transfusions, cerebral oxygen saturation correlated strongly and positively with the haemoglobin level (r = 0·811, P = 0·001) and with percent normal haemoglobin (r = 0·786, P = 0·002), and negatively with abnormal sickle haemoglobin (r = −0·775, P = 0·003). None of these correlations was found to be statistically significant in the seven subjects given exchange transfusions. Cerebral oxygen saturation measured in the sickle cell disease subjects after transfusions was still significantly lower than in the anaemic subjects without sickle cell disease and in the normal controls (49·6% vs. 59·8% and 61·3%, P = 0·001).Conclusions  We found that patients with sickle cell disease have subnormal values of cerebral oxygen saturation. Red cell transfusions significantly increased the brain oxygenation in these patients. Cerebral oximetry may be a useful, noninvasive method for assessing the effect of circulating normal red cells in sickle cell patients after transfusions.
Identification of Neurones in the Female Rat Hypothalamus That Express Oestrogen Receptor‐Alpha and Vesicular Glutamate Transporter‐2
Authors: Eyigor O. , Lin W. , Jennes L. 
Published: February 2004

AbstractOestrogen exerts its effects in the brain by binding to and activating two members of the nuclear receptor family, oestrogen receptor (ER)‐α and ER‐β. Evidence suggests that oestrogen‐receptive neurones participate in the generation of reproductive behaviours and that they convey the oestrogen message to gonadotropin‐releasing hormone (GnRH) neurones. The aim of the present study was to identify the neurochemical phenotype of a subset of oestrogen receptor‐expressing neurones. To this aim, we focused on the glutamate neuronal system, which is one of the most important stimulators of GnRH synthesis and release. We used the presence of vesicular glutamate transporter‐2 (VGLUT2) mRNA as a specific marker to identify glutamate neurones and employed dual in situ hybridization to localize ERα mRNA‐(35S‐labelling) and VGLUT2 mRNA‐(digoxigenin‐labelling) expressing neurones within the hypothalamus. The results show that the overall distribution of VGLUT2 mRNA and ERα mRNA are consistent with previous data in the literature. Dual‐labelled neurones were localized in the ventrolateral part of the ventromedial nucleus where 81.3 ± 3.4% of the ERα mRNA containing neurones expressed VGLUT2 mRNA, in the anteroventral periventricular nucleus (30% colocalization) and in the medial preoptic nucleus (19% colocalization). Only 4.4% of the ERα expressing neurones in the arcuate nucleus contained VGLUT2 mRNA. These findings reveal that certain subpopulations of oestrogen‐receptive neurones are glutamatergic in select hypothalamic areas that are known to regulate reproductive behaviour and GnRH neurones in the female rat. Thus, the oestrogen signal could be propagated through glutamate neurones to distant sites and influence the activity of the postsynaptic neurones.