bluuebunny/crossref_metadata_2025 huggingface dataset:
α1‐RECEPTOR OR ADENOSINE A1‐RECEPTOR DEPENDENT PATHWAY ALONE IS NOT SUFFICIENT BUT SUMMATION OF THESE PATHWAYS IS REQUIRED TO ACHIEVE AN ISCHAEMIC PRECONDITIONING EFFECT IN RABBITS
Authors: Baba Kaori , Minatoguchi Shinya , Zhang Chengxi , Kariya Tatsuya , Uno Yoshihiro , Kawai Takao , Takahashi Masahiko , Takemura Genzou , Fujiwara Hisayoshi
Published: March 2005

1. It is reported that α1‐receptors and adenosine A1‐receptors are involved in the ischaemic preconditioning (PC) effect on infarct size (IS). However, it is still unclear to what extent α1‐receptors and adenosine A1‐receptors contribute to the mechanism of PC. Therefore, we investigated the extent of the contribution of α1‐receptors and adenosine A1 receptors to the PC effect on IS and examined the relationship between these receptors and protein kinase C.

2. Infarct size was measured in rabbits subjected to 30 min ischaemia and 48 h reperfusion. Tyramine (Tyr) was intravenously administered before 30 min ischaemia in the absence or presence of bunazosin (BN, α1‐receptor blocker) and staurosporine (ST), a protein kinase C inhibitor, respectively. R(‐)N6‐(2‐phenylisapropyl)‐adenosine (PIA), a selective adenosine A1 agonist, was intravenously administered before 30 min ischaemia in the absence or presence of 8‐p‐sulphophenyltheophylline (8SPT), an adenosine blocker and ST, respectively. In the PC groups, BN, BN + PIA, 8SPT, 8SPT + Tyr or placebo saline was injected before or during PC.

3. Both Tyr and PIA reduced the IS, which was blocked by BN and 8SPT, respectively. The IS‐reducing effect of Tyr or PIA was blocked by ST. The IS‐reducing effect of PC was completely blocked by BN and 8SPT, respectively. The blocking effect of BN on the IS‐reducing effect of PC was abolished by adding PIA during PC ischaemia. The blocking effect of 8SPT on the IS‐reducing effect of PC was abolished by adding Tyr before PC ischaemia.

4. These data suggest that an α1‐receptor dependent pathway exists and an adenosine A1‐receptor dependent pathway, stimulation of both of which activates protein kinase C, then reduces the IS. However, exclusive stimulation of a single α1‐receptor dependent pathway or a single adenosine A1‐receptor dependent pathway alone is not sufficient but the summation of these pathways is required to achieve a PC effect on IS in rabbits.
ANAPHYLACTIC HEPATIC VENOCONSTRICTION IS ATTENUATED BY NITRIC OXIDE RELEASED VIA SHEAR STRESS‐DEPENDENT AND ‐INDEPENDENT MECHANISMS IN GUINEA PIG
Authors: Shibamoto Toshishige , Ruan Zonghai , Cui Sen , Kurata Yasutaka , Koizumi Tomonobu , Kubo Keishi
Published: March 2005

1. The role of shear stress in nitric oxide (NO)‐mediated attenuation of anaphylactic venoconstriction was studied using an isolated ovalbumin‐sensitized guinea pig liver.

2. Guinea pigs were actively sensitized by a subcutaneous injection of 1 mg ovalbumin. Two weeks after sensitization, the livers were perfused with diluted blood under constant flow or constant perfusion pressure. The constant flow could result in increased shear stress during constriction, while the constant perfusion pressure could prevent changes in shear stress. Using the double occlusion technique to estimate the hepatic sinusoidal pressure, pre‐ and postsinusoidal constriction was evaluated. Hepatic anaphylaxis was induced by an injection of ovalbumin (4 µg) into the perfusate, the volume of which was 40 mL.

3. Under either constant flow or pressure, anaphylaxis caused venoconstriction of predominantly presinusoids over postsinusoids, although anaphylactic venoconstriction under constant pressure was significantly greater than that under constant flow. When shear stress was held constant by maintaining constant perfusion pressure, a NO synthase inhibitor, Nω‐nitro‐l‐arginine methyl ester (l‐NAME, 100 µmol/L), potentiated similarly both pre‐ and postsinusoidal constriction induced by anaphylaxis. This suggests that hepatic anaphylaxis shear stress‐independently generates NO, resulting in dilatation of both pre‐ and postsinusoidal vessels in a similar magnitude. In contrast, when shear stress was allowed to rise under constant flow, anaphylactic presinusoidal constriction was preferentially potentiated by l‐NAME.

4. Hepatic anaphylaxis can increase NO production in a shear stress‐independent manner and dilates similarly both pre‐ and postsinusoids, while NO produced in a shear stress‐dependent manner attenuates predominantly venoconstriction of the presinusoids where shear stress is preferentially increased.
Short‐term effects of repetitive arm work and dynamic exercise on glucose metabolism and insulin sensitivity
Authors: Bergfors M. , Barnekow‐Bergkvist M. , Kalezic N. , Lyskov E. , Eriksson J. W.
Published: March 2005

Aim: To determine whether repetitive arm work, with a large component of static muscle contraction alters glucose metabolism and insulin sensitivity.

Method: Euglycemic clamps (2 h) were started in ten healthy individuals 15 min after 37 min periods of: (1) repetitive arm work in a simulated occupational setting; (2) dynamic concentric exercise on a cycle ergometer at 60% ofVO2maxand (3) a resting regime as a control. During the experimental periods, blood samples were collected, blood pressure was measured repeatedly and electrocardiogram (ECG) was recorded continuously. During the clamps, euglycemia was maintained at 5 mmol l−1and insulin was infused at 56 mU m−2 min−1for 120 min.

Results: The insulin‐mediated glucose disposal rate (M‐value) for the steady‐state period (60–120 min) of the clamp, tended to be lower following arm work than for both cycling and resting regimes. When dividing the steady‐state period into 20‐min intervals, the insulin sensitivity index (ISI) was significantly lower for arm work compared with the resting control situation between 60–80 min (P = 0.04) and 80–100 min (P = 0.01), respectively. Catecholamines increased significantly for arm work and cycling compared with resting regime. Data from heart rate variability (HRV) measurements indicated significant sympathetic activation during repetitive arm work.

Conclusion: The results indicate that repetitive arm work might acutely promote insulin resistance, whereas no such effect on insulin resistance was produced by dynamic concentric exercise.
Chronic aerobic exercise enhances components of the classical and novel insulin signalling cascades in Sprague–Dawley rat skeletal muscle
Authors: Bernard J. R. , Crain A. M. , Rivas D. A. , Herr H. J. , Reeder D. W. , Yaspelkis B. B.
Published: March 2005

Aim:  The aim of this study was to provide a more extensive evaluation of the effects of chronic aerobic exercise on various components of the insulin signalling cascade in normal rodent skeletal muscle because of the limited body of literature that exists in this area of investigation.

Methods:  Male Sprague–Dawley rats were assigned to either control (n = 7) or chronic aerobic exercise (n = 7) groups. Aerobic exercise animals were run 3 day week−1 for 45 min on a motor‐driven treadmill (32 m min−1, 15% grade) for a 12 week period. Following the training period, all animals were subjected to hind limb perfusion in the presence of 500 μU mL−1 insulin to determine what effect chronic aerobic training had on various components of the insulin signalling cascade, c‐Cbl protein concentration and c‐Cbl phosphorylation.

Results:  Twelve weeks of aerobic training did not alter skeletal muscle Akt 1/2 protein concentration, Akt Ser 473 phosphorylation, Akt Thr 308 phosphorylation, Akt 1 activity, aPKC‐ζ protein concentration, aPKC‐λ protein concentration or c‐Cbl protein concentration. In contrast, chronic aerobic exercise increased insulin‐stimulated phosphatidylinositol 3‐kinase, Akt 2 kinase and aPKC‐ζ/λ kinase activities, as well as c‐Cbl tyrosine phosphorylation, in a fibre type specific response to aerobic training. In addition, chronic aerobic exercise enhanced insulin‐stimulated plasma membrane glucose transporter 4 (GLUT4) protein concentration.

Conclusion:  Collectively, these findings suggest that chronic aerobic exercise enhances components of both the classical and novel insulin signalling cascades in normal rodent skeletal muscle, which may contribute to an increased insulin‐stimulated plasma membrane GLUT4 protein concentration.
Non‐invasive monitoring of muscle blood perfusion by photoplethysmography: evaluation of a new application
Authors: Sandberg M. , Zhang Q. , Styf J. , Gerdle B. , Lindberg L.‐G.
Published: March 2005

Aim:  To evaluate a specially developed photoplethysmographic (PPG) technique, using green and near‐infrared light sources, for simultaneous non‐invasive monitoring of skin and muscle perfusion.

Methods:  Evaluation was based on assessments of changes in blood perfusion to various provocations, such as post‐exercise hyperaemia and hyperaemia following the application of liniment. The deep penetrating feature of PPG was investigated by measurement of optical radiation inside the muscle. Simultaneous measurements using ultrasound Doppler and the new PPG application were performed to elucidate differences between the two methods. Specific problems related to the influence of skin temperature on blood flow were highlightened, as well.

Results:  Following static and dynamic contractions an immediate increase in muscle perfusion was shown, without increase in skin perfusion. Liniment application to the skin induced a rapid increase in skin perfusion, but not in muscle. Both similarities and differences in blood flow measured by Ultrasound Doppler and PPG were demonstrated. The radiant power measured inside the muscle, by use of an optical fibre, showed that the near‐infrared light penetrates down to the vascular depth inside the muscle.

Conclusions:  The results of this study indicate the potentiality of the method for non‐invasive measurement of local muscle perfusion, although some considerations still have to be accounted for, such as influence of temperature on blood perfusion.
Transcriptional responses of rat skeletal muscle following hypoxia‐reoxygenation and near ischaemia‐reperfusion
Authors: Aravindan N. , Williams M. T. , Riedel B. J. C. J. , Shaw A. D.
Published: March 2005

Aim:  The effect of ischaemia/reperfusion or hypoxia/reoxygenation on gene expression has not been extensively studied. We hypothesized that in skeletal muscle, tissue hypoxia of similar magnitude but induced by different mechanisms would lead to different transcriptional responses.

Methods:  Muscle gene transcription was assessed using microarray analysis and reverse transcriptase polymerase chain reaction in 18 rats exposed to regional hind limb near ischaemia/reperfusion (n = 6), hypoxia/reoxygenation (n = 6) or sham operation (n = 6). Hypoxic burden was measured by the area under the PtO2–time curve.

Results:  PtO2 was reduced in both the near ischaemia/reperfusion and hypoxia/reoxygenation groups. Although the hypoxic burden was similar, the genomic response was different for each condition. Near ischaemia/reperfusion had a greater effect on gene expression than hypoxia/reoxygenation. Using stringent criteria for changes in gene expression (i.e. more than or equal to twofold change vs. control) unique patterns of gene expression could be identified suggesting individualized transcriptional responses to each of these injuries. Several genes, including insulin‐like growth factor 1 (IGF‐1) and cyclin‐dependent kinase inhibitor (p27Kip1) were induced by both injury types and these may have potential clinical application as markers of tissue damage. In contrast, no single gene was downregulated by both injury conditions.

Conclusions:  The mechanism of skeletal muscle hypoxia has a profound effect on its subsequent transcriptional response. We identified several potential candidates as markers of skeletal muscle ischaemic damage.
Effects of cold‐water immersion on VEGF mRNA and protein expression in heart and skeletal muscles of rats
Authors: Kim J. C. , Yi H. K. , Hwang P. H. , Yoon J. S. , Kim H. J. , Kawano F. , Ohira Y. , Kim C. K.
Published: March 2005

Aim:  The effects of cold exposure on gene and protein expression of vascular endothelial growth factor (VEGF), in heart and skeletal muscles, were studied in male adult Wistar rats.

Methods:  Cold immersion was accomplished by submerging the rats in shoulder‐deep water maintained at ∼18 °C, either acutely (1 h) or chronically (1 h day−1, 5 days week−1 for 20 weeks). The expressions of VEGF mRNA and protein in heart, gastrocnemius, and soleus muscles were examined by Northern and Western blotting and competitive‐polymerase chain reaction techniques.

Results:  The expressions of VEGF mRNA and protein were markedly increased in cardiac muscle of the cold‐immersed group, particularly in the 1‐hour exposure group, whereas VEGF mRNA and protein in gastrocnemius were decreased significantly after an acute exposure. Although the protein level in gastrocnemius remained low in the chronically exposed group, the expression of mRNA of VEGF165 with chronic exposure in this group returned to the control level and that of VEGF206 was 15% greater than that in controls. The expression of mRNA for VEGF165 in soleus was also lowered by acute cold exposure, although that for VEGF206 was stable. However, VEGF protein was increased by 50%. After 20 weeks, all of these parameters were increased over the levels found in the controls.

Conclusion:  These results suggest that the VEGF gene may be a major regulatory factor in cardiac and skeletal muscle adaptation to the cold environment stimulating angiogenesis and thermogenesis.
Effect of gemfibrozil on the pharmacokinetics and pharmacodynamics of racemic warfarin in healthy subjects
Authors: Lilja Jari J. , Backman Janne T. , Neuvonen Pertti J.
Published: March 2005

Aims

Case reports suggest that gemfobrozil can increase the anticoagulant effect of warfarin. Because gemfibrozil inhibits CYP2C9 in vitro, we studied its effects on the pharmacokinetics and pharmacodynamics of racemic warfarin.

Methods

In a randomized cross‐over study, 10 healthy subjects ingested 600 mg gemfibrozil or placebo twice daily for 8 days. On day 3, they were administered a single dose of 10 mg racemic R‐S‐warfarin orally. The concentrations of R‐ and S‐warfarin in plasma and thromboplastin time were monitored up to 168 h.

Results

Gemfibrozil decreased the mean (±SD) area under the plasma concentration‐time curve [AUC(0–∞)] of S‐warfarin by 11%, from 19.9 ± 5.2 mg l−1 h to 17.6 ± 4.7 mg l−1 h (95% CI on the difference −3.7, −0.78; P < 0.01) and that of R‐warfarin by 6% from  31.3 ± 7.5 mg l−1 h during  the  gemfibrozil  phase  to  29.5 ± 6.9 mg l−1 h during the placebo phase (95% CI −3.3, −0.33; P < 0.05). There were no significant differences in the elimination half‐lives of S‐ or R‐warfarin between the phases. Gemfibrozil did not alter the anticoagulant effect of warfarin.

Conclusion

Unexpectedly, gemfibrozil slightly decreased the plasma concentrations of R‐ and S‐warfarin. Displacement of warfarin from plasma albumin by gemfibrozil or its interference with the absorption of warfarin could explain the present findings. Usual therapeutic doses of gemfibrozil seem to have limited effects on the pharmacokinetics and pharmacodynamics of single dose warfarin in healthy subjects.
Raloxifene pharmacokinetics in males with normal and impaired renal function
Authors: Czock David , Keller Frieder , Heringa Mette , Rasche Franz Maximilian
Published: March 2005

Aims

To compare raloxifene pharmacokinetics between renally impaired and healthy subjects.

Methods

Raloxifene 120 mg was administered to 10 males with renal impairment (creatinine 2–4 mg dl−1) and to 10 healthy males. Data were analysed by two noncompartmental and one compartmental nonlinear regression methods.

Results

The medians (95% confidence interval) of the area under the curves (AUC) were 35.1 (25.8, 74) and 20.5 (16.8, 28.0) h ng ml−1 per mg kg−1, P < 0.01, and of the clearances (CL/F) were 28.5 (13.5, 38.8) and 48.8 (35.8, 59.4) l h−1 kg−1, P < 0.01, in renally impaired and healthy subjects, respectively. 95% Confidence intervals on the differences for AUC and CL/F were 6.5–44.1 and −35.1 to −7.9, respectively.

Conclusion

Exposure to raloxifene was twice as high in males with renal impairment compared with healthy subjects.
Insertion/deletion polymorphism of the ACE gene and adherence to ACE inhibitors
Authors: Schelleman H. , Klungel O. H. , Van Duijn C. M. , Witteman J. C. M. , Hofman A. , De Boer A. , Stricker B. H. Ch
Published: March 2005

Aims

We investigated whether the insertion/deletion (I/D) polymorphism of the ACE gene modified the adherence to ACE inhibitors as measured by the discontinuation of an ACE inhibitor, or addition of another antihypertensive drug.

Methods

This was a cohort study among 239 subjects who started ACE inhibitor therapy. A Cox proportional hazard model was used to calculate relative risk (RR).

Results

During follow‐up there was no significant difference between subjects with the DD, ID or II genotype (DD vs II; RR = 1.17, 95%CI: 0.78, 1.77 and ID vs II; RR = 1.06, 95%CI: 0.73, 1.55) in adherence.

Conclusions

The I/D polymorphism of the ACE gene does not influence the adherence to ACE inhibitors.
Effect of ginkgo and ginger on the pharmacokinetics and pharmacodynamics of warfarin in healthy subjects
Authors: Jiang Xuemin , Williams Kenneth M. , Liauw Winston S. , Ammit Alaina J. , Roufogalis Basil D. , Duke Colin C. , Day Richard O. , McLachlan Andrew J.
Published: March 2005

Aim

The aim of this study was to investigate the effect of two common herbal medicines, ginkgo and ginger, on the pharmacokinetics and pharmacodynamics of warfarin and the independent effect of these herbs on clotting status.

Methods

This was an open label, three‐way crossover randomized study in 12 healthy male subjects, who received a single 25 mg dose of warfarin alone or after 7 days pretreatment with recommended doses of ginkgo or ginger from herbal medicine products of known quality. Dosing with ginkgo or ginger was continued for 7 days after administration of the warfarin dose. Platelet aggregation, international normalized ratio (INR) of prothrombin time, warfarin enantiomer protein binding, warfarin enantiomer concentrations in plasma and S‐7‐hydroxywarfarin concentration in urine were measured. Statistical comparisons were made using anova and the 90% confidence intervals (CIs) of the ratio of log transformed parameters are reported.

Results

INR and platelet aggregation were not affected by administration of ginkgo or ginger alone. The mean (95% CI) apparent clearances of S‐warfarin after warfarin alone, with ginkgo or ginger were 189 (167–210) ml h−1, 200 (173–227) ml h−1 and 201 (171–231) ml h−1, respectively. The respective apparent clearances of R‐warfarin were 127 (106–149) ml h−1, 126 (111–141) ml h−1 and 131 (106–156) ml h−1. The mean ratio (90% CI) of apparent clearance for S‐warfarin was 1.05 (0.98–1.21) and for R‐warfarin was 1.00 (0.93–1.08) when coadministered with ginkgo. The mean ratio (90% CI) of AUC0−168 of INR was 0.93 (0.81–1.05) when coadministered with ginkgo. The mean ratio (90% CI) of apparent clearance for S‐warfarin was 1.05 (0.97–1.13) and for R‐warfarin was 1.02 (0.95–1.10) when coadministered with ginger. The mean ratio (90% CI) of AUC0−168 of INR was 1.01 (0.93–1.15) when coadministered with ginger. The mean ratio (90% CI) for S‐7‐hydroxywarfarin urinary excretion rate was 1.07 (0.85–1.32) for ginkgo treatment, and 1.00 (0.81–1.23) for ginger coadministration suggesting these herbs did not affect CYP2C9 activity. Ginkgo and ginger did not affect the apparent volumes of distribution or protein binding of either S‐warfarin or R‐warfarin.

Conclusions

Ginkgo and ginger at recommended doses do not significantly affect clotting status, the pharmacokinetics or pharmacodynamics of warfarin in healthy subjects.
Reproducibility of forearm vasodilator response to intra‐arterial infusion of calcitonin gene‐related peptide assessed by venous occlusion plethysmography
Authors: Vanmolkot Floris H. M. , De Hoon Jan N. J. M.
Published: March 2005

Aims

To assess the reproducibility of the forearm blood flow (FBF) response to intra‐arterial infusion of calcitonin‐gene related peptide (CGRP), measured by venous occlusion plethysmography. In addition, to compare different ways of expressing the FBF response and perform sample size calculations.

Methods

On two separate visits, CGRP (10 ng min−1 dl−1 forearm) was infused for 45 min into the brachial artery of six healthy subjects. Reproducibility was assessed by calculating mean difference, repeatability coefficient, within‐subject coefficient of variation (WCV) and intraclass correlation coefficient.

Results

CGRP increased FBF from 2.8 ± 0.4 and 3.2 ± 0.7 (at baseline) to 15.4 ± 1.4 and 15.2 ± 1.5 ml min−1 dl−1 forearm (at 45 min) on visits 1 and 2, respectively (P < 0.0001 for both visits). Mean difference in FBF at 45 min between both visits was 0.3 ml min−1 dl−1 forearm (repeatability coefficient: 4.1 ml min−1 dl−1 forearm). This FBF response appeared to be more reproducible when expressed as absolute FBF in the infused arm (WCV 11%) compared with absolute FBF‐ratio between both arms (WCV 37%), percentage change from baseline in FBF in the infused arm (WCV 29%) and percentage change from baseline in FBF‐ratio (WCV 40%). When expressed as absolute FBF, a sample size of five (95% confidence interval: 2–12) subjects gives 90% power at a type I error probability of 0.05 to detect a 25% shift in FBF response.

Conclusions

Intra‐arterial infusion of CGRP results in a forearm vasodilator response which is reproducible between days. This response is most reproducible when expressed as absolute FBF. The presented methodology provides a suitable pharmacodynamic model to assess the in vivo activity of CGRP‐receptor antagonists in a small number of subjects.
Absence of circadian variation in the pharmacokinetics of lopinavir/ritonavir given as a once daily dosing regimen in HIV‐1‐infected patients
Authors: Van Heeswijk R. P. G. , Bourbeau M. , Seguin I. , Giguere P. , Garber G. E. , Cameron D. W.
Published: March 2005

Aims

To compare the pharmacokinetics of lopinavir/ritonavir (LPV/r) 800/200 mg administered once daily in the morning compared with the evening.

Methods

This was a randomized, two‐way, cross‐over study in HIV+ subjects. In each subject the pharmacokinetics of each drug were characterized after 2 weeks of LPV/r 800/200 mg administered once daily at 08.00 h and 19.00 h. On study days, LPV/r was taken with a standardized meal (800 kCal, 25% from fat) after fasting for at least 5 h. LPV/r concentrations were measured by LC‐MS/MS, and the data were analyzed by noncompartmental pharmacokinetic analysis.

Results

Fourteen subjects completed the study (all men, mean age/weight 44 year/81 kg). The median (interquartile range) LPV AUC(0,24 h), maximum plasma concentration (Cmax) and concentration at the end of the dosing interval (C24 h) after am and pm dosing was, respectively, 143 (116–214) mg l−1 h, 12.8 (10.3–17.2) mg l−1, 1.34 (0.58–3.25) mg l−1, and 171 (120–232) mg l−1 h, 12.9 (8.22–16.3) mg l−1, 1.15 (0.59–1.98) mg l−1. The geometric mean ratio (GMR, am : pm) and 95% CI of the LPV AUC(0,24 h), Cmax, and C24 h was 0.91 (0.79, 1.06), 1.11 (0.94, 1.32), and 1.19 (0.72, 1.96), respectively. The median ritonavir Cmax after am and pm dosing was 1.05 and 0.90 mg l−1, respectively. The GMR (95% CI) of the RTV AUC(0,24 h), Cmax, and C24 h was 0.93 (0.80, 1.08), 1.27 (1.00, 1.63), and 1.04 (0.68, 1.60), respectively. Administration of LPV/r in a once‐daily regimen was generally well tolerated.

Conclusions

No differences were observed in the pharmacokinetics of LPV/r after am or pm dosing with food, which suggests that this once daily combination, can be taken in the morning or evening. Such flexibility in dosing may improve adherence.
The teaching of drug development to medical students: collaboration between the pharmaceutical industry and medical school
Authors: Stanley A. G. , Jackson D. , Barnett D. B.
Published: March 2005

Collaboration between the medical school at Leicester and a local pharmaceutical company, AstraZeneca, led to the design and implementation of an optional third year special science skills module teaching medical students about drug discovery and development. The module includes didactic teaching about the complexities of the drug discovery process leading to development of candidate drugs for clinical investigation as well as practical experience of the processes involved in drug evaluation preclinically and clinically. It highlights the major ethical and regulatory issues concerned with the production and testing of novel therapies in industry and the NHS. In addition it helps to reinforce other areas of the medical school curriculum, particularly the understanding of clinical study design and critical appraisal. The module is assessed on the basis of a written dissertation and the critical appraisal of a drug advertisement. This paper describes the objectives of the module and its content. In addition we outline the results of an initial student evaluation of the module and an assessment of its impact on student knowledge and the opinion of the pharmaceutical industry partner. This module has proven to be popular with medical students, who acquire a greater understanding of the work required for drug development and therefore reflect more favourably on the role of pharmaceutical companies in the UK.
The role of interleukin-16 in murine contact hypersensitivity
Authors: Masuda K , Katoh N , Soga F , Kishimoto S
Published: March 2005

Contact hypersensitivity (CHS) is a T-cell-mediated skin inflammatory response. It is controversial whether CD4+ T cells play an enhancing or regulatory role in the pathogenesis of CHS. Because interleukin (IL)-16 is a chemoattractant cytokine for CD4-expressing cells, we investigated the involvement of IL-16 in the CHS reaction. IL-16 production was induced in the epidermis and dermis during the elicitation phase of the CHS response with trinitrochlorobenzene. In the sensitization phase, the single application of haptens such as trinitrochlorobenzene and oxazolone also induced IL-16, whereas primary irritants or vehicle control did not. IL-16 was produced mainly by CD11c-negative cells in the epidermis during the elicitation phase. Furthermore, treatment of sensitized mice with anti-IL-16 neutralizing MoAb enhanced the ear swelling and reduced the number of infiltrating CD4+ T cells. These data indicate that IL-16 plays a role in CHS, whereby IL-16 induces CD4+ T cells and these CD4+ T cells subsequently exhibit down-regulating properties.
The effects of renal transplantation on circulating dendritic cells
Authors: Hesselink D A , Vaessen L M B , Hop W C J , Schoordijk W , IJzermans J N M , Baan C C , Weimar W
Published: March 2005

The effects of immunosuppressive agents on T cell function have been well characterized but virtually nothing is known about the effects of renal transplantation on human dendritic cells (DCs). With the use of flow cytometry, we studied the kinetics of myeloid and plasmacytoid DCs in peripheral blood of 24 kidney allograft recipients before and after transplantation, and in 23 donors before and after kidney donation. All patients were treated with tacrolimus, mycophenolate mofetil and prednisone. Surgery resulted in a strong decline in the number of myeloid and plasmacytoid DCs, both in kidney donors and in their recipients. However, in donors this effect was transient, as the numbers of both DC subsets had normalized completely by the third postoperative month. In contrast, the recovery of myeloid DC counts in kidney transplant recipients was only incomplete at the end of the 3-month follow-up, despite tapering of immunosuppression. The seven patients who required additional immunosuppressive treatment because of acute rejection experienced an even more marked decrease in DC counts in the early postoperative period compared with patients who remained rejection-free. Surgical procedures markedly affect the numbers of circulating myeloid and plasmacytoid DCs. Immunosuppressive drugs have important additional in vivo effects on this cell type and impair the reconstitution of the myeloid DC subset in peripheral blood after renal transplantation.
Persistently high IgA serum levels are a marker of immunological or virological failure of combined antiretroviral therapy in children with perinatal HIV-1 infection
Authors:   The Italian Register for HIV Infection in Children, Chiappini Elena , Galli Luisa , Tovo Pier-Angelo , Gabiano Clara , De Martino Maurizio
Published: March 2005

Non-expensive and low-complexity surrogate markers for monitoring the response to combined antiretroviral therapy (combined-ART) are needed in poor-resource settings where routine assessment of CD4+ T-lymphocyte count and viral load can not be afforded. We longitudinally evaluated Ig serum levels in 234 HIV-1 infected children receiving combined-ART with ≥ 3 drugs. Since Ig levels physiologically vary with age, differences at different age periods were evaluated as differences in z-scores calculated using the mean and standard deviation of the normal population for each age period. Data from 17 (7·3%) children with immunological failure and from 54 (23·1%) children with virological failure of combined-ART were compared with data from not-failed children. At baseline children with immunological failure showed higher IgM z-scores (P = 0·042) than children without. After 3–12 months of therapy immunologically failed children displayed higher viral loads (P < 0·0001) and IgA (P = 0·043) z-scores than not-failed children. Similarly, at the same follow-up time, children with virological failure showed lower CD4+ T-lymphocyte percentages (P = 0·005) and higher IgA z-scores (P < 0·0001) than not-failed children. No difference in IgG or IgM z-scores was evidenced between failed and not-failed children after 3–12 months of therapy. In conclusion, IgA serum level is a cheap and low-complexity marker of immunological or virological failure of combined-ART which might be adopted in poor-resource settings.
Pneumolysin-mediated activation of NFκB in human neutrophils is antagonized by docosahexaenoic acid
Authors: Fickl H , Cockeran R , Steel H C , Feldman C , Cowan G , Mitchell T J , Anderson R
Published: March 2005

This study was designed to investigate the relationship between influx of extracellular Ca2+, activation of NFκB and synthesis of interleukin-8 (IL-8) following exposure of human neutrophils to subcytolytic concentrations (8·37 and 41·75 ng/ml) of the pneumococcal toxin, pneumolysin, as well as the potential of the omega-3 polyunsaturated fatty acid, docosahexaenoic acid, to antagonize these events. Activation and translocation of NFκB were measured using a radiometric electrophoretic mobility shift assay, while influx of extracellular Ca2+ and synthesis of IL-8 were determined using a radioassay and an ELISA procedure, respectively. Exposure of neutrophils to pneumolysin was accompanied by influx of Ca2+, activation of NFκB, and synthesis of IL-8, all of which were eliminated by inclusion of the Ca2+-chelating agent, EGTA (10 m m), in the cell-suspending medium, as well as by pretreatment of the cells with docosahexaenoic acid (5 and 10 µg/ml). The antagonistic effects of docosahexaenoic acid on these pro-inflammatory interactions of pneumolysin with neutrophils were not attributable to inactivation of the toxin, and required the continuous presence of the fatty acid. These observations demonstrate that activation of NFκB and synthesis of IL-8, following exposure of neutrophils to pneumolysin are dependent on toxin-mediated influx of Ca2+ and that these potentially harmful activities of the toxin are antagonized by docosahexaenoic acid.
CARD15 polymorphisms are associated with anti-Saccharomyces cerevisiae antibodies in caucasian Crohn's disease patients
Authors: Cruyssen B Vander , Peeters H , Hoffman I E A , Laukens D , Coucke P , Marichal D , Cuvelier C , Remaut E , Veys E M , Mielants H , De Vos M , De Keyser F
Published: March 2005

Carriage of CARD15 gene polymorphisms and the serological marker anti-Saccharomyces cerevisiae antibodies (ASCA) are two markers for Crohn's disease (CD). Similar phenotypes have been associated with both markers. In the present study we analysed whether both markers were associated with each other and, if so, whether this association could be explained by a direct link or by an indirect association with those phenotypes. Therefore, we included 156 consecutive Caucasian CD patients and assessed the prevalence of the three common single nucleotide polymorphisms in the CARD15 gene. Serum samples were analysed for IgA and IgG ASCA by ELISA. CD patients with CARD15 polymorphisms were more frequently ASCA positive (OR 2·7 (1.4–5.2); P = 0·002) and had higher titres for ASCA IgA (P = 0·005) and ASCA IgG (P < 0·001) compared to patients carrying the wild type polymorphisms. Multivariate analysis demonstrated that this association was independent from ileal disease, penetrating disease and stricturing disease, the need for resective bowel surgery, familial cases, smoking habits and early age at onset. Homozygotes or compound heterozygotes for CARD15 polymorphisms had significantly more frequent ASCA positivity compared to single heterozygotes (OR 9·1 (1.1–74.2), Pc (corrected P-value) = 0·030). These data indicate that there is a significant association between the carriage of CARD15 polymorphisms and ASCA, independent of the described phenotypes. Moreover, ASCA positivity is more frequent in CD patients carrying 2 CARD15 polymorphisms compared to single heterozygotes.
Alpha tropomyosin as a self-antigen in patients with Behçet's disease
Authors: Mahesh S P , Li Zhuqing , Buggage R , Mor F , Cohen I R , Chew E Y , Nussenblatt R B
Published: March 2005

We report for the first time a significant increased lymphoproliferative response to alpha tropomyosin as well as observing autoantibodies to tropomyosin observed in Behçet's disease (BD) patients with posterior uveitis. Peripheral blood mononuclear cells (PBMCs) from 18 BD patients with posterior uveitis, 18 patients with other forms of noninfectious uveitis, 9 patients with retinal damage due to photocoagulation as well as 18 healthy donors were evaluated for antigen-specific lymphoproliferative responses to alpha tropomyosin and its derivative peptides. The proliferative responses of PBMCs to these antigens were studied using 3H thymidine incorporation assay. Serum samples were also screened by ELISA for autoantibodies against tropomyosin. Six of the 18 (33%) BD patients with posterior uveitis showed increased proliferative response to alpha tropomyosin or its derivative peptides, while none of the healthy, disease controls were positive. The mean lymphoproliferative responses to tropomyosin were significantly higher (P < 0·02) in the BD patients compared to healthy or disease controls. Higher titres of anti-tropomyosin antibodies were also seen in four of the 18 BD patients but none in the healthy or disease control groups (P < 0·002). The occurrence of these abnormalities supports a possible role for alpha tropomyosin as a self-antigen in a subset of patients with Behçet's disease.
Effect of specific antigen stimulation on intraepithelial lymphocyte migration to small intestinal mucosa
Authors: Komoto S , Miura S , Koseki S , Goto M , Hachimura S , Fujimori H , Hokari R , Hara Y , Ogino T , Watanabe C , Nagata H , Kaminogawa S , Hibi T , Ishii H
Published: March 2005

Migration of intraepithelial lymphocytes (IELs) into intestinal epithelium is not yet well understood. We established an IEL-cell line from ovalbumin (OVA) 23–3 transgenic (Tg) mice and investigated the effect of antigen stimulation on the dynamic process of IEL migration into small intestinal mucosa. The cell line was a T cell receptor (TCR) αβ+ CD4+ CD8– phenotype, expressing αEβ7 integrin in 90% of cells. Under intravital microscopy, the lined IELs adhered selectively to the microvessels of the intestinal villus tip of the Tg mice. The accumulation of IELs was significantly inhibited by an antibody against β7-integrin and MAdCAM-1. When IELs were stimulated with OVA, the accumulation was attenuated compared to that of resting cells, with decreased expression of αEβ7 integrin. In Tg mice fed with OVA, the number of IELs which migrated in the villus mucosa was significantly smaller than in the non-fed controls. The preferential migratory capacity of IELs to villus mucosa may be altered by specific antigen stimulations.
Age-associated deficiency in activation-induced up-regulation of telomerase activity in CD4+ T cells
Authors: Marinova E , Han S , Zheng B
Published: March 2005

For lymphocytes, the ability to undergo clonal expansion is crucial for effective immune function. Telomerase activity compensates for telomere erosion during cell division and contributes to the capability of lymphocytes to maintain cellular proliferation. In addition, telomerase activity may have a fundamental role in cell growth and survival. To determine whether age-related immune dysfunction is associated with an abnormality in telomerase activity, we investigated telomerase activity in T cell populations from young adult and aged mice. Our data show that the ability of T cells from aged mice to up-regulate telomerase activity after activation was significantly diminished. This age-related deficiency in telomerase induction is restricted to CD4+ T cells, as CD8+ T cells retain the capability to up-regulate telomerase activity. These findings reinforce the notion that age-related immune dysfunction results mainly from impairment of helper T cells, and may have important implications for designing novel means to improve immune responses in aged individuals by enhancing CD8+ T cell functions, which are crucial in both viral and tumour immunity.
Circulating YKL-40 levels during human endotoxaemia
Authors: Johansen J S , Krabbe K S , Møller K , Pedersen B K
Published: March 2005

YKL-40 is secreted by macrophages and neutrophils and patients with bacterial infections have elevated circulating YKL-40. The aim was to evaluate changes in plasma YKL-40 (determined by enzyme-linked immunosorbent assay (ELISA) at 0, 2, 4, 8, 24 and 32 h) in eight healthy volunteers after injection with Esherichia coli endotoxin or saline. Plasma YKL-40 increased after endotoxin injection from 31 µg/l (range 19–39 µg/l) to a maximum of 159 µg/l (61–552 µg/l, P < 0·01) at 24 h. The finding that plasma YKL-40 increased after endotoxin injection compared with saline (P < 0·001) suggests that YKL-40 has a functional role in infections.
A transgenic mouse model for studying the clearance of blood-borne pathogens via human complement receptor 1 (CR1)
Authors: Repik A , Pincus S E , Ghiran I , Nicholson-Weller A , Asher D R , Cerny A M , Casey L S , Jones S M , Jones S N , Mohamed N , Klickstein L B , Spitalny G , Finberg R W
Published: March 2005

Complement receptor 1 (CR1) on the surface of human erythrocytes facilitates intravascular clearance of complement-opsonized pathogens. The need for complement activation can be circumvented by directly coupling the organism to CR1 using a bispecific monoclonal antibody heteropolymer (HP). Lack of a functional homologue to CR1 on mouse erythrocytes has made it difficult to study HP-dependent clearance of pathogens in small animals. We have developed a transgenic mouse that expresses human CR1 on erythrocytes. CR1 antigen is of appropriate size and in a clustered distribution as confirmed by immunoblotting and fluorescence microscopy, respectively. HP that immobilized bacteriophage ΦX174 prototype pathogen to erythrocyte CR1 of the transgenic mice increased the rate of clearance of the virus compared with HP that bound bacteriophage, but not CR1. This transgenic mouse model will allow evaluation of different HPs for their in vivo efficacy and potential as human therapeutics.
Hepatitis B surface antigen presentation and HLA-DRB1*– lessons from twins and peptide binding studies
Authors: Kruger A , Adams P , Hammer J , Böcher W O , Schneider P M , Rittner C , Hoehler T
Published: March 2005

The aim of this study was to investigate the underlying mechanisms of the genetic association between certain HLA-DRB1* alleles and the immune response to HBsAg vaccination. Therefore, HBsAg peptide binding to HLA-DR molecules was measured in vitro by peptide binding ELISAs. Additionally, HBsAg-specific T cell reaction and cytokine profile of immune response were analysed ex vivo in ELISPOT assays and DR-restriction of T-cell proliferative responses was investigated with HBsAg specific T cell clones. In addition, we compared HBsAg specific T cell responses of 24 monozygotic and 3 dizygotic twin pairs after HBsAg vaccination. Our results showed that the peptide binding assays did not reflect antigen presentation in vivo. DR alleles associated with vaccination failure like DRB1*0301 and 0701 efficiently presented HBsAg peptides. In 11 of 24 investigated monozygotic twin pairs we observed pronounced differences in the recognition of HBsAg peptides. This study indicates that HLA–DR associations with HBsAg vaccination response are not caused by differences in peptide binding or by a shift in the Th1/Th2 profile. Our findings strongly argue for differences in the T cell recognition of peptide/MHC complexes as the critical event in T cell responsiveness to HBsAg.
Induction of CD4 T cell proliferation andin vitroTh1-like cytokine responses to measles virus
Authors: Howe R C , Dhiman N , Ovsyannikova I G , Poland G A
Published: March 2005

Mechanisms that lead to induction of life-long immunity to measles virus (MV) are poorly understood. In the present study, we have assessed the activation, proliferation and cytokine secreting function of peripheral blood T cells from MV immune individuals. Expression of cell blastogenesis markers, such as increased forward light scatter and CD38 expression, peaked 5–7 days after infection of peripheral blood mononuclear cells (PBMC) with the live attenuated Edmonston strain of MV. Subset analysis revealed that both CD3– and CD3+ cells expressed activation markers but that the CD3+ T cells predominated late in the culture period corresponding to maximal proliferation and cell recovery. The majority of CD3+ T cells consisted of CD4+CD8– cells. IFN-γ and IL-4 production similarly showed optimal production late in culture. Depletion of CD4 cells prior to culture and MV stimulation completely abrogated both IFN-γ and IL-4 production, whereas depletion of CD8 cells did not diminish production, suggesting that CD4+CD8– T cells were principally involved in production of these cytokines. Finally, optimal IFN-γ production was elicited at high MV doses and IL-4 at much lower doses. These results suggest that among MV immune individuals, in vitro responses to measles are dominated by CD4+ T cells that, depending on antigen dose, primarily produce a Th1-like and, to a lesser extent, a Th1/Th2-mixed pattern of cytokine release.
Dichotomy of protective cellular immune responses to human visceral leishmaniasis
Authors: Khalil E A G , Ayed N B , Musa A M , Ibrahim M E , Mukhtar M M , Zijlstra E E , Elhassan I M , Smith P G , Kieny P M , Ghalib H W , Zicker F , Modabber F , Elhassan A M
Published: March 2005

Healing/protective responses in human visceral leishmaniasis (VL) are associated  with  stimulation/production  of  Th1  cytokines,  such  as  interferon IFN-γ, and conversion in the leishmanin skin test (LST). Such responses were studied for 90 days in 44 adult healthy volunteers from VL non-endemic areas, with no past history of VL/cutaneous leishmaniasis (CL) and LST non-reactivity following injection with one of four doses of Alum-precipitated autoclaved Leishmania major (Alum/ALM) ± bacille Calmette–Guérin (BCG), a VL candidate vaccine. The vaccine was well tolerated with minimal localized side-effects and without an increase in antileishmanial antibodies or interleukin (IL)-5. Five volunteers (5/44; 11·4%) had significant IFN-γ production by peripheral blood mononuclear cells (PBMCs) in response to Leishmania antigens in their prevaccination samples (P = 0·001) but were LST non-reactive. On day 45, more than half the volunteers (26/44; 59·0%) had significantly high LST indurations (mean 9·2 ± 2·7 mm) and high IFN-γ levels (mean 1008 ± 395; median 1247 pg/ml). Five volunteers had significant L. donovani antigen-induced IFN-γ production (mean 873 ± 290; median 902; P = 0·001), but were non-reactive in LST. An additional five volunteers (5/44; 11·4%) had low IFN-γ levels (mean 110 ± 124 pg/ml; median 80) and were non-reactive in LST (induration = 00 mm). The remaining eight volunteers had low IFN-γ levels, but significant LST induration (mean 10 ± 2·9 mm; median 11). By day 90 the majority of volunteers (27/44; 61·4%) had significant LST induration (mean 10·8 ± 9·9 mm; P < 0·001), but low levels of L. donovani antigen-induced IFN-γ (mean 66·0 ± 62 pg/ml; P > 0.05). Eleven volunteers (11/44; 25%) had significantly high levels of IFN-γ and LST induration, while five volunteers had low levels of IFN-γ (<100 pg/ml) and no LST reactivity (00 mm). One volunteer was lost to follow-up. In conclusion, it is hypothesized that cellular immune responses to human VL are dichotomatous, and that IFN-γ production and the LST response are not in a causal relationship. Following vaccination and probably cure of VL infection, the IFN-γ response declines with time while the LST response persists. LST is a simple test that can be used to assess candidate vaccine efficacy.
Neutrophil chemokines in epithelial inflammatory processes of human tonsils
Authors: Sachse F , Ahlers F , Stoll W , Rudack C
Published: March 2005

CXC chemokines are thought to play an important role at sites of inflammation. Because ELR+ CXC chemokines are expressed in different types of tonsillitis we investigated the role of the surface/crypt epithelium of human tonsils  in  producing  ELR+  CXC  chemokines:  interleukin  (IL)-8  (CXCL8), ENA-78 (CXCL5), GRO-α (CXCL1) and GCP-2 (CXCL6). Tonsillar tissue was obtained from patients undergoing tonsillectomy and chemokine expression was investigated by means of immunohistochemistry. A549 cells were used as a model to study kinetics of chemokine expression in epithelial cells. Cells were stimulated with tumour necrosis factor (TNF)-α, lipopolysaccharide (LPS) and supernatants derived from aerobic/anaerobic Staphylococcus aureus strains. Chemokine expression was measured by quantitative reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). We observed epithelial expression of IL-8, GRO-α and GCP-2 in different types of tonsillitis, whereas ENA-78 was rarely expressed. In A549 cells abundant expression of ENA-78 was detected. IL-8 and GCP-2 are expressed in an acute type of tonsillitis whereas GRO-α was frequently detectable both in chronically and acutely inflamed tonsils. ENA-78 does not seem to play a pivotal role in tonsillitis in vivo.