bluuebunny/crossref_metadata_2025_split huggingface dataset:
A lagged, density‐dependent relationship between jack pine budworm Choristoneura pinus pinus and its host tree Pinus banksiana
Authors: Nealis V. G. , Magnussen S. , Hopkin A. A. 
Published: December 2004

Abstract. 1. Survival of newly emerged jack pine budworm Choristoneura pinus pinus is related to the density of available pollen cones (microsporangiate strobili) produced by its host tree, jack pine Pinus banksiana.2. A 7‐year time series of observations from a plot network in Ontario, Canada, compared the propensity of jack pine to produce pollen cones, τ, on trees that were either defoliated or undisturbed by the jack pine budworm.3. Non‐defoliated jack pine trees have a high propensity to produce pollen cones. More than one‐third of these trees produced pollen cones in every year of the series. Propensity varied significantly among plots and trees. Temporal patterns in propensity were also highly variable but within a plot propensity was often autocorrelated in time.4. Defoliation by the jack pine budworm was associated with forest plots composed of the oldest and the largest trees and with the fewest trees per hectare. Within a plot, outbreaks lasted 3 or 4 years although individual trees were only defoliated in 1 or 2 years.5. The propensity to produce pollen cones in jack pine was reduced in the years after defoliation. The most pronounced reductions in propensity occurred where defoliation was most severe.6. The reduction in propensity to produce pollen cones resulting from previous defoliation, coupled with the dependence of jack pine budworm survival on the availability of pollen cones, induces a lagged, negative feedback between the density of the consumer and that of its resource.7. The lagged, density‐dependent relationship between jack pine budworm and its jack pine host contributes to oscillatory dynamics of the jack pine budworm. Comparison of the outbreak behaviour of jack pine budworm with that of the closely related eastern spruce budworm C. fumiferana suggests that differences in the strength of the host‐plant interaction may account for differences in the relative frequency of outbreaks in the respective systems.
Oviposition habitat selection by the mosquito Culiseta longiareolata in response to risk of predation and conspecific larval density
Authors: Kiflawi Moshe , Blaustein Leon , Mangel Marc 
Published: December 2004

Abstract. 1. Most female Culiseta longiareolata (Diptera: Culicidae) avoid ovipositing in pools that contain the predatory backswimmer Notonecta maculata. Such oviposition habitat selection has been suggested to reflect a trade‐off between the risk of predation on larvae and potential density‐dependent fitness costs. This putative trade‐off was examined. In particular, evidence was sought in support of direct female response to local heterogeneity in habitat quality.2. Three habitat types were established using artificial outdoor pools: predator pools, and non‐predator pools with either low or high densities of Culiseta larvae. During each experimental night, females were offered one of the three possible pair‐wise treatment combinations.3. The majority (≈88%) of females oviposited in low‐density pools rather than in the predator‐ or high‐density pools. Furthermore, a substantially higher proportion of females oviposited in predator pools when faced with the high‐density alternative, however this was due largely to fewer females ovipositing in high‐ vs low‐density pools.4. Females of a second mosquito species (Culex laticinctus), the larvae of which are at a lower risk of predation, were predicted to exhibit weaker aversion to N. maculata; this prediction was supported only weakly.5. Oviposition habitat selection by female C. longiareolata does not appear to involve a behavioural response that is based on individual assessment of local heterogeneity in relative pool quality, at least not at the spatial scale examined here; alternative explanations are discussed.
Lack of association of the Glu298Asp polymorphism of endothelial nitric oxide synthase with manifest coronary artery disease, carotid atherosclerosis and forearm vascular reactivity in two Austrian populations
Authors: Schmoelzer I. , Renner W. , Paulweber B. , Malaimare L. , Iglseder B. , Schmid P. , Schallmoser K. , Wascher T. C. 
Published: December 2004

AbstractObjective Conflicting data exists about the possible contribution of the homozygous Asp/Asp genotype of the Glu298Asp polymorphism of endothelial nitric oxide synthase to human atherosclerotic vascular disease. We investigated the polymorphism in two independent study populations: a case–control study including patients with angiographically verified coronary artery disease (CAD) on the one hand and a cross‐sectional epidemiological study on the other hand.Methods The Glu298Asp polymorphism was determined by PCR‐RFLP as established. In the case–control study (240 patients and 248 controls) a possible association between the polymorphism and CAD, and age of onset of CAD and myocardial infarction was investigated. In the cross‐sectional epidemiological study (932 subjects) intima‐media thickness (IMT) of the carotid artery as well as morphological plaque burden and forearm vascular reactivity (peak postischemic reactive hyperaemia, determined by venous occlusion plethysmography) were measured.Results In the case–control study genotype distribution (Glu/Glu; Glu/Asp; Asp/Asp) was not different between the CAD patients (43/46/11%) and the controls (49/41/10%, P = NS). No association of the polymorphism with age of onset of CAD or myocardial infarction was found. In the epidemiological study no influence of the genetic variant on IMT was observed after correction for classical determinants of IMT (average IMT: Asp/ Asp: 0·077 ± 0·011 mm; Glu/Glu and Glu/Asp: 0·080 ± 0·012 mm, P = NS). Forearm vascular reactivity was also not different between homozygous Asp/Asp subjects and Glu/Glu and Glu/Asp subjects (peak‐reactive hyperaemia 20·1 ± 7·3 mL min−1 100 mL−1 vs. 20·0 ± 6·5 mL min−1 100 mL−1, P = NS).Conclusions Our results suggest that there is no association of the Glu298Asp polymorphism with coronary or carotid atherosclerosis or forearm vascular reactivity in these populations recruited in a country with a rather high risk for atherosclerosis. We suggest additional investigations to be performed in populations at different risk for coronary events to further elucidate the possible contribution of this polymorphism to vascular disease.
Effect of oxytocin on nitric oxide activity controlling gonadotropin secretion in humans
Authors: Chiodera P. , Volpi R. , Manfredi G. , Bortesi M. L. , Capretti L. , Magotti M. G. , Saccanijotti G. , Coiro V. 
Published: December 2004

AbstractBackground Previously described inhibitory effects of the nitric oxide synthase (NOS) inhibitor L‐NAME on luteinizing hormone‐releasing hormone (LH‐RH)‐induced LH and follicle stimulating hormone (FSH) secretion in humans suggested modulation by nitric oxide (NO) of the gonadotropin‐releasing action of LH‐RH.Design In order to establish whether oxytocin (OT) participates in this regulatory mechanism, 10 normal men were treated with LH‐RH (100 µg as an i.v. bolus) given alone or in the presence of L‐NAME (40 µg kg−1 injected plus 50 µg kg−1 infused i.v. for 60 min), OT (2 IU injected plus 4 IU infused i.v. for 60 min) or a combination of both drugs.Results The administration of OT was unable to change the gonadotropin responses to LH‐RH. In contrast, L‐NAME significantly reduced both FSH and LH increments induced by LH‐RH. When L‐NAME was given in the presence of OT, the LH and FSH responses to LH‐RH were similar to those observed after the administration of LH‐RH alone.Conclusion These data suggest antagonistic actions of OT and L‐NAME in the control of NOS activity in regulation of gonadotropin secretion induced by LH‐RH.
Novel LPL mutation (L303F) found in a patient associated with coronary artery disease and severe systemic atherosclerosis
Authors: Saika Y. , Sakai N. , Takahashi M. , Maruyama T. , Kihara S. , Ouchi N. , Ishigami M. , Hiraoka H. , Nakamura T. , Yamashita S. , Matsuzawa Y. 
Published: December 2004

AbstractBackground Patients with lipoprotein lipase (LPL) deficiency had been generally thought to be spared accelerated atherosclerosis in spite of a marked elevation of plasma triglyceride levels. However, it has been recently reported that some heterozygous and homozygous LPL‐deficient patients are associated with premature atherosclerosis. In this paper, we report a 55‐year‐old type I hyperlipidaemic patient with a novel missense mutation in the LPL gene.Patient and results The patient had suffered from coronary artery disease, abdominal aortic aneurysm, and stenoses of the bilateral renal arteries and superficial femoral arteries. Sequencing of the genomic DNA revealed that the patient was a homozygote for the mutation, a G to C transition at nucleotide position 1069 in the exon 6, resulting in an amino acid substitution of Phe for Leu303 (L303F). Approximately ∼6% and ∼40% of normal LPL activity and LPL mass, respectively, were detected in the patient's postheparin plasma. An in vitro expression study demonstrated that COS7 cells transfected with L303F mutant cDNA produced a 40% amount of LPL protein in cell lysates compared with normal cDNA, but no protein was detected in the media. Lipoprotein lipase activity was completely absent in both lysates and media of the cells transfected with the mutant cDNA, suggesting that this mutation in the LPL gene results in the production of a functionally inactive protein.Conclusion This case suggests that the LPL missense mutation (L303F), which impairs lipolysis but preserves the LPL mass, is proatherogenic.
Topical butyrate improves efficacy of 5‐ASA in refractory distal ulcerative colitis: results of a multicentre trial
Authors: Vernia P. , Annese V. , Bresci G. , D’Albasio G. , D’Incà R. , Giaccari S. , Ingrosso M. , Mansi C. , Riegler G. , Valpiani D. , Caprilli R. ,   GISC (Gruppo Italiano per lo Studio del Colon and del Retto)
Published: December 2004

AbstractBackground The treatment of distal ulcerative colitis, refractory to conventional 5‐ASA/steroid treatment, is still a matter of debate. The present study aimed at confirming, with adequate statistical power, previous data indicating the usefulness of topical butyrate and 5‐ASA in the treatment of this condition.Design Double‐blind, placebo‐controlled, multicentre study. A total of 51 patients with distal (< 65 cm) ulcerative colitis, refractory to topical 5‐ASA/cortisone, were randomly allocated to receive topical 5‐ASA 2 g and 80 mM L−1 sodium‐butyrate bid (Group A; 24 patients) or 5‐ASA 2 g and 80 mL saline bid (Group B; 27 patients) for 6 weeks. Sigmoidoscopy with biopsies, as well as clinical and laboratory evaluations, were carried out at enrollment and at the end of the trial. Primary endpoints: remission or marked improvement in endoscopic, histologic and clinical findings.Results Most parameters showed a significant improvement vs. baseline in both groups. Remission in six patients and improvement in 12 patients in Group A vs. one remission and 13 with improvement in Group B (P < 0·05). A significant difference in favour of Group A was recorded regarding the number of bowel movements (P < 0·01), urgency (P < 0·05) and the patients’ self evaluation (P < 0·01).Discussion The combined treatment with topical butyrate and 5‐ASA is significantly more effective than 5‐ASA alone in the management of refractory distal colitis. Further improvements in the treatment of refractory distal ulcerative colitis may be feasible based on the identification of patient subgroups and the association of two or more active drugs. Butyrate may well be one of them.
Quantitative determination of MDR1 mRNA expression in peripheral blood lymphocytes: a possible role of genetic polymorphisms in the MDR1 gene
Authors: Oselin K. , Nowakowski‐Gashaw I. , Mrozikiewicz P. M. , Wolbergs D. , Pähkla R. , Roots I. 
Published: December 2004

AbstractBackground P‐glycoprotein is a transmembrane efflux pump that extrudes a wide variety of drugs, thereby reducing their intracellular access. In humans, P‐glycoprotein is encoded by the MDR1 gene. Recently, several single nucleotide polymorphisms in the MDR1 gene were identified. Moreover, it was postulated that, in addition to the full‐length P‐glycoprotein, a ‘mini’ P‐glycoprotein was also present in lymphocytes.Materials and methods We investigated the effect of the genetic polymorphisms G2677T and C3435T in the MDR1 gene on MDR1 mRNA expression in FACS‐sorted peripheral blood CD4+, CD8+, CD19+, and CD56+ cells. MDR1 mRNA expression was determined in 45 healthy individuals using a real‐time quantitative RT‐PCR.Results We detected the highest expression of MDR1 mRNA in CD56+ cells, followed by CD8+ > CD4+ > CD19+ cells. However, genetic polymorphisms of the MDR1 gene failed to affect (P > 0·05) MDR1 mRNA levels in the peripheral blood lymphocytes. Furthermore, the transcript levels for the MDR1 N‐terminal half were almost two‐fold lower than that of the MDR1 C‐terminal half in all cell populations investigated (P < 0·0001).Conclusions An almost two‐fold difference in MDR1 C‐ and N‐terminal half expressions supports the presence of mini‐P‐glycoprotein, an alternatively spliced form of the full‐length molecule, in peripheral blood lymphocytes.
Treatment with hormone replacement therapy lowers remnant lipoprotein particles in healthy postmenopausal women: results from a randomized trial
Authors: Ossewaarde M. E. , Dallinga‐Thie G. M. , Bots M. L. , Van Der Schouw Y. T. , Rabelink T. J. , Grobbee D. E. , Westerveld H. T. 
Published: December 2004

AbstractBackground Recent evidence indicates that remnant lipoprotein particles (RLPs) may play a role in atherosclerosis. Remnant lipoprotein particles have been suggested to be the most atherogenic particles among the triglyceride‐rich lipoproteins. In particular, these triglyceride‐rich particles were identified as an independent risk factor for cardiovascular diseases (CVD) in women. Postmenopausal hormone replacement therapy (HRT) beneficially affects lipid profile, although total triglyceride levels often increase. Evidence on the effects of HRT on RLPs is limited. We determined whether 3 months’ treatment of postmenopausal women with Tibolone or conjugated oestrogens combined with medroxyprogesterone acetate (CEE + MPA) affects RLP‐cholesterol (RLP‐C).Materials and methods One hundred and five healthy postmenopausal women were randomized to either 2·5 mg of Tibolone, 0·625 mg of CEE + 2·5 mg of MPA or placebo. At baseline and after 3 months the lipid profile was determined. For assessment of RLP‐C we used an immunoseparation‐based method.Results Treatment with CEE + MPA significantly reduced RLP‐C (−0·03 mmol L−1, P‐value = 0·01) and appeared to increase triglycerides (0·15 mmol L−1, P‐value = 0·20) compared with placebo. Tibolone did not significantly change RLP‐C (−0·01 mmol L−1, P‐value = 0·35) and significantly decreased triglycerides (−0·35 mmol L−1, P‐value = 0·004).Conclusions Treatment of postmenopausal women with conjugated oestrogens and medroxyprogesterone acetate reduced RLP‐C, without a reduction in total triglycerides, whereas Tibolone did affect triglyceride levels, but not RLP‐C. These observations may be relevant for explaining the effect of HRT on cardiovascular risk in healthy postmenopausal women.
In vivo IL‐10 and TGF‐β production by PBMC from long‐term kidney transplant recipients with excellent graft function: a possible feedback mechanism participating in immunological stability
Authors: Alberú Josefina , Richaud‐Patin Yvonne , Vázquez‐Lavista Luis Gabriel , de Leo Claudia , Guzmán‐Rodríguez Hugo , Mancilla Eduardo , Correa‐Rotter Ricardo , Chew‐Wong Alfredo , Llorente Luis 
Published: December 2004

Abstract:  Background:  Interleukin‐10 (IL‐10) and transforming growth factor‐β (TGF‐β) are Th2‐derived multifunctional cytokines that exhibit potent immunoregulatory and anti‐inflammatory properties which might prolong graft survival. The aim of this study was to explore whether spontaneous production of IL‐10 and TGF‐β by blood mononuclear cells correlates with excellent long‐term graft function.Methods:  A cross‐sectional study was carried out in 32 kidney transplant recipients, without albuminuria, treated with azathioprine and prednisone. Spontaneous IL‐10 and TGF‐β were measured by enzyme‐linked immunosorbent assay in supernatants from 24 h cultured unstimulated peripheral blood mononuclear cells. Both cytokines were also determined in 10 healthy kidney donors.Results:  There was no correlation between IL‐10 or TGF‐β with any variable tested, namely age, SCr, histocompatibility, and post‐transplant follow‐up. In vivo IL‐10 production displayed a statistical trend to be higher in transplant recipients than in controls (362.3 ± 465, range 12.5–1929.3 pg/ml, and 189 ± 170, range 4.17–485.7 pg/ml, respectively; p = 0.08), whereas no difference was observed in TGF‐β among the same groups (134.7 ± 79.2, range 68–421 pg/ml, and 121.4 ± 25.8, range 75–151 pg/ml, respectively). Interestingly, a statistically significant inverse correlation was observed between IL‐10 and TGF‐β in kidney transplant recipients (p = 0.03).Conclusions:  The higher IL‐10 production observed in long‐term kidney transplant recipients supports the notion that this cytokine contributes in decreasing allogenic immune responses and allows prolongation of allograft survival. The balance between TGF‐β and IL‐10 may be of paramount importance in graft acceptance.
Aldosterone resistance in kidney transplantation is in part induced by a down‐regulation of mineralocorticoid receptor expression1
Authors: Heering PJ , Kurschat C , Vo DT , Klein‐Vehne N , Fehsel K , Ivens K 
Published: December 2004

Abstract: Background: After renal transplantation immunosuppressive drugs‐like cyclosporin A (CsA) and FK506 induce either hypoaldosteronism or pseudo‐hypoaldosteronism presenting with hyperkalemia and metabolic acidosis. We investigated the relationship between renal allograft function under CsA therapy and plasma aldosterone concentration, potassium‐ and water homeostasis and mineralocorticoid receptor (MR) expression level in peripheral leukocytes.Methods: We studied 21 renal transplant patients under CsA therapy and 12 healthy controls. Transplant recipients were studied before and under fludrocortisone treatment. Using quantitative reverse‐phase polymerase chain reaction (RT‐PCR) specific for the MR, we analyzed the level of expression of MR in peripheral leukocytes.Results: In acidotic transplant recipients (HCO318.5 ± 1.2 mM) renal function was only slightly impaired with 2.0 ± 0.2 mg creatinine/dL when compared with 1.8 ± 0.3 mg/dL (ns) in non‐acidotic patients (HCO323.0 ± 2.8 mM). Mean plasma aldosterone levels in renal transplant recipients did not differ from control levels (150 ± 33 pg/mL vs. 148 ± 33 pg/mL, ns). In contrast, the expression level of MR in peripheral leukocytes of renal transplant recipients treated with CsA was significantly decreased when compared with healthy controls without renal disease (120 ± 78 vs. 423 ± 73 RNA molecules/0.5 μg total RNA, p < 0.01). The level of expression of MR in renal transplant recipients did not differ between acidotic patients and non‐acidotic patients (ns). The application of fludrocortisone reversed hyperkalemia and metabolic acidosis without significant effect on MR expression.Conclusions: The present data demonstrate that hyperkalemia and metabolic acidosis following CsA treatment in kidney transplantation might be associated with a down‐regulation of MR expression on peripheral leukocytes. Electrolyte imbalance is reversible on application of fludrocortisone. This observation supports fludrocortisone treatment in transplant patients with severe electrolyte disturbances.
Factors associated with (un)willingness to be an organ donor: importance of public exposure and knowledge
Authors: Haustein Silke V , Sellers Marty T 
Published: December 2004

Abstract:  Background:  Transplantation is increasingly limited by the supply of donor organs. Identifying subgroups that do not support organ donation will allow targeted efforts to increase organ donation.Methods:  A total of 185 non‐acutely ill outpatients visiting a community physician's office voluntarily completed a survey designed to capture views and general knowledge/misconceptions about cadaveric organ donation/transplantation.Results:  Of 185 patients, 86 were willing to donate, 42 were unwilling, and 57 were unsure. Willingness to donate was significantly associated with: having discussed the topic with family; having known a cadaveric organ donor; age 55 yr; having graduated high school; recognizing the organ shortage as the primary problem in transplantation; having received a post‐high school degree; having seen public information within 30 d; and having a family member in health care (all p≤0.05). Not significant were: gender; race; religious affiliation or regular church attendance; knowing a transplant recipient or wait‐listed patient; and having easy internet access. Those unwilling/unsure more often thought: organ allocation is based on race/income; organ donation is expensive for the donor family; designated donors may not receive full emergency room care; a brain‐dead person can recover.Conclusions:  Intense efforts to improve public awareness and knowledge about organ donation/transplantation are necessary to maximize donation and the overall success of transplantation.
An effective medium for isolating Sphaeropsis sapinea from asymptomatic pines
Authors: Blodgett J. T. , Bonello P. , Stanosz G. R. 
Published: December 2004

SummaryThe pathogen Sphaeropsis sapinea can persist in stems and branches of asymptomatic pines and can later induce disease when triggered by host stress. Several experiments were conducted to test if:(i) medium amended with tannic acid (TA) can increase the frequency of cultural detection of this shoot blight and canker pathogen from asymptomatic red pine (Pinus resinosa) stems, and (ii) S. sapinea can persist in asymptomatic red pine in the field following artificial inoculation. TA (0.5% w/v) in 2% (w/v) water agar proved to be the best medium for isolation of S. sapinea among a larger number of tested media. The addition of TA had little or no effect on the growth of two group A and two group B isolates of S. sapinea. However, when TA was added, 11 other fast‐growing fungal isolates from stems/branches of red or jack pines (P. banksiana) were inhibited and grew more slowly (p < 0.05) than both S. sapinea groups. The TA‐amended medium improved cultural detection of S. sapinea from 2‐year‐old, asymptomatic red pine nursery seedlings compared with two other methods used for the cultural detection of S. sapinea (32%vs. 8.5% and 18% recovery; p < 0.001 and p = 0.031, respectively). A field test using the TA‐amended media established that S. sapinea can persist asymptomatically in red pine trees for at least 1 year. This medium significantly reduces the frequency of false‐negatives from asymptomatic field material.