bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of p38 MAPK and increased glucose transport in chronic hibernating swine myocardium
Authors: McFalls Edward O. , Hou MingXiao , Bache Robert J. , Best Aaron , Marx David , Sikora Joseph , Ward Herbert B.
Published: August 2004

In preconditioned myocardium, activation of the mitogen-activated protein kinase (MAPK) p38 leads to increased glucose uptake via enhanced GLUT-4 translocation. Glucose uptake is also increased in chronic hibernating myocardium, but the role of p38 MAPK and GLUT-4 translocation has not been studied. Nine swine underwent instrumentation of the proximal left anterior descending coronary artery (LAD) with a small, external constrictor. At 3 mo after instrumentation, myocardial glucose uptake by PET imaging was higher in the LAD than in the remote region under basal, fasted conditions (0.08 ± 0.02 vs. 0.04 ± 0.01 μmol·min−1·g−1, P < 0.05). Compared with the remote region, the LAD region demonstrated increased membrane-bound GLUT-4 relative to total content (61 ± 04 vs. 45 ± 06%, P < 0.05), higher glycogen (28.37 ± 4.41 vs. 19.26 ± 1.87 mg/g wet wt, P < 0.05), and increased inducible nitric oxide synthase (NOS) activity (1.43 ± 0.34 vs. 0.51 ± 0.21 activity/mg protein, P < 0.05). p38 MAPK was 47 ± 14% higher in the LAD than in the remote region ( P < 0.05) and correlated well with the absolute degree of GLUT-4 membrane-bound translocation ( r = 0.81, P < 0.01), relative increase in glycogen ( r = 0.70, P < 0.05), and total NOS activity ( r = 0.68, P < 0.05). In chronic hibernating myocardial tissue, p38 MAPK activation is increased under basal fasted conditions and correlates well with the increased degree of GLUT-4 translocation, glycogen accumulation, and NOS activity. As in preconditioned myocardium, activation of p38 MAPK may play an important role in the metabolic adaptations that characterize chronic hibernating myocardium.
Vasomotor responses in MnSOD-deficient mice
Authors: Andresen Jon J. , Faraci Frank M. , Heistad Donald D.
Published: August 2004

MnSOD is the only mammalian isoform of SOD that is necessary for life. MnSOD−/−mice die soon after birth, and MnSOD+/−mice are more susceptible to oxidative stress than wild-type (WT) mice. In this study, we examined vasomotor function responses in aortas of MnSOD+/−mice under normal conditions and during oxidative stress. Under normal conditions, contractions to serotonin (5-HT) and prostaglandin F2α(PGF2α), relaxation to ACh, and superoxide levels were similar in aortas of WT and MnSOD+/−mice. The mitochondrial inhibitor antimycin A reduced contraction to PGF2αand impaired relaxation to ACh to a similar extent in aortas of WT and MnSOD+/−mice. The Cu/ZnSOD and extracellular SOD inhibitor diethyldithiocarbamate (DDC) paradoxically enhanced contraction to 5-HT and superoxide more in aortas of WT mice than in MnSOD+/−mice. DDC impaired relaxation to ACh and reduced total SOD activity similarly in aortas of both genotypes. Tiron, a scavenger of superoxide, normalized contraction to 5-HT, relaxation to ACh, and superoxide levels in DDC-treated aortas of WT and MnSOD+/−mice. Hypoxia, which reportedly increases superoxide, reduced contractions to 5-HT and PGF2αsimilarly in aortas of WT and MnSOD+/−mice. The vasomotor response to acute hypoxia was similar in both genotypes. In summary, under normal conditions and during acute oxidative stress, vasomotor function is similar in WT and MnSOD+/−mice. We speculate that decreased mitochondrial superoxide production may preserve nitric oxide bioavailability during oxidative stress.
Inhibition of K+conductance in descending vasa recta pericytes by ANG II
Authors: Pallone Thomas L. , Cao Chunhua , Zhang Zhong
Published: August 2004

We tested whether K+channel inhibition accompanies ANG II-induced depolarization of descending vasa recta (DVR) pericytes. An increase in extracellular K+concentration ([K+]o) from 5 to 100 mM depolarized resting pericytes but had no effect after prolonged (10 nM, 20 min) ANG II exposure. In contrast, reduction of extracellular Cl−concentration ([Cl−]o) from 154 to 34 mM had a minor effect on resting membrane potential but strongly depolarized pericytes treated with ANG II. The K+channel blockers BaCl2(0.1, 1 mM) and tetraethylammonium (TEA; 30 mM) depolarized resting pericytes but did not affect membrane potential of ANG II-treated pericytes. Pericyte whole cell currents were reduced by ANG II and nearly eliminated by combined ANG II exposure and the Cl−channel blocker niflumic acid (100 μM). Augmentation of inward current induced by raising [K+]Ofrom 5 to 50 mM was eliminated by preexposure to ANG II. TEA- and BaCl2-sensitive outward currents, generated by depolarizing pericytes from −80 to −40 mV, were eliminated by ANG II. We conclude that ANG II depolarizes DVR pericytes by a combination of Cl−channel activation and K+channel inhibition.
Possible Induction of Cholinesterase in Epileptic Patients Treated With Anticonvulsant Drugs: Relationship With Lipoprotein Levels
Authors: Tutor‐Crespo María J. , Hermida Jesús , Tutor J. Carlos
Published: August 2004

The effect of enzyme‐inducing anticonvulsant drugs on the serum concentrations of lipoproteins has been widely studied. However, there is little agreement between the results with regard to the possible development of a lipoprotein profile related to an increased or decreased cardiovascular risk. It has been suggested that cholinesterase (ChE) could be induced by these drugs, something of undeniable interest as ChE appears to have a relation to the metabolism of lipoproteins. The serum activity of ChE was determined in a group of 90 adult epileptic patients (56 male and 34 female) treated with phenobarbital, phenytoin, and carbamazepine. The liver enzyme induction produced by these drugs was then evaluated by determining serum gamma‐glutamyltranspherase activity and urinary excretion of D‐glucaric acid. A significant increase of serum ChE (p < 0.005) was found in the group of patients compared to a control group (n = 49) with a similar distribution for age and sex. A significant correlation was found for both male and female patients between ChE and concentrations of triglycerides, phospholipids, cholesterol, low‐density lipoprotein (LDL) phospholipids, LDL‐cholesterol, and apolipoprotein B (p < 0.01). Similarly, in female patients, ChE had a significant correlation with the total cholesterol/high‐density lipoprotein (HDL) cholesterol and LDL‐cholesterol/HDL‐cholesterol ratios (p < 0.01). The ChE/ HDL‐cholesterol relationship, which has been proposed as a marker for cardiovascular risk, presented significant correlations with the total cholesterol/HDL‐cholesterol and LDL‐cholesterol/HDL‐cholesterol ratios in patients of both sexes (p < 0.001). In the case of epileptic patients treated with enzyme‐inducing anticonvulsant drugs, there may be an association between the possible induction of ChE and the metabolism of lipoproteins containing apolipoprotein B.
Sex‐Related Differences in the Pharmacokinetics of Oral Ciprofloxacin
Authors: Overholser Brian R. , Kays Michael B. , Forrest Alan , Sowinski Kevin M.
Published: August 2004

The oral pharmacokinetics of ciprofloxacin were studied in healthy volunteers to assess the influence of sex on its disposition. Subjects (8 males, 7 females) received a single oral dose of ciprofloxacin 750 mg, blood and urine samples were collected, and ciprofloxacin concentrations were determined. A two‐compartment open‐model with two or three absorption phases, each one having a fitted independent lag time, best fit the data using a weighted least squares estimator. Univariate and multivariate regression analyses were performed to determine the influence of renal function, weight, and subject sex on the oral clearance (CLS/F) and apparent steady‐state volume of distribution (Vss/F) of ciprofloxacin. Females had a median Cmax of ciprofloxacin that was 30% greater than males and a significantly smaller median (range) Vss/F: 81.1 (44.8–111.6) versus 170.9 (140.9–213.4), respectively (p < 0.01). In addition, females had increased exposure to ciprofloxacin, with a slower median (range) CLS/F of 28.3 L/h (24.5–33.4) compared to 44.4 L/h (41.4–53.7) for males (p < 0.01). Regression analyses revealed that subject sex was the only significant predictor of CLS/F (p < 0.001), but both body weight (p= 0.04) and subject sex (p< 0.005) were significant predictors of Vss/F. Fixed oral doses of ciprofloxacin will lead to higher maximum concentration and total drug exposure in females compared to males and do not appear to be solely related to weight‐based differences.
Pharmacokinetics and Safety of Solifenacin Succinate in Healthy Young Men
Authors: Smulders Ronald A. , Krauwinkel Walter J. , Swart Pieter J. , Huang Moses
Published: August 2004

The pharmacokinetic profile of solifenacin succinate (YM905; Vesicare), a new once‐daily bladder‐selective muscarinic receptor antagonist, was examined in 2 controlled trials of healthy young men. A single‐dose study evaluated 5‐, 10‐, 20‐, 40‐, 60‐, 80‐, and 100‐mg doses. A multidose study evaluated 5‐, 10‐, 20‐, and 30‐mg doses. In the single‐dose study, mean time to maximal concentration and elimination half‐life ranged from 3.3 to 4.8 and from 40.2 to 57.6 hours, respectively; in the multidose study, the corresponding ranges were 2.9 to 5.8 and 45.0 to 64.8. Plasma concentration and area under the curve increased linearly with single doses in both trials. At steady state, a less regular increase was seen, with higher values in the 20‐mg group than in the 30‐mg group. All doses in the single‐dose study were well tolerated. At steady state, only the 30‐mg dose was not well tolerated. The most commonly reported adverse events were dry mouth, blurred vision, and headache. Solifenacin 5 and 10 mg, either as single doses or at steady state, had minimal effect on salivary flow, visual nearpoint, and the incidence of adverse events. Solifenacin was well tolerated up to single doses of 100 mg and after multiple doses of 20 mg. Its pharmacokinetic profile makes it suitable for qd administration.
Ibandronate: A Clinical Pharmacological and Pharmacokinetic Update
Authors: Barrett Joanne , Worth Eric , Bauss Frieder , Epstein Solomon
Published: August 2004

Ibandronate is a potent nitrogen‐containing bisphosphonate. It has a strong affinity for bone mineral and potently inhibits osteoclast‐mediated bone resorption. Ibandronate is effective for the treatment of hypercalcemia of malignancy, metastatic bone disease, postmenopausal osteoporosis, corticosteroid‐induced osteoporosis, and Paget's disease. Oral ibandronate is rapidly absorbed (tmax < 1 hour), with a low bioavailability (0.63%) that is further reduced (by up to 90%) in the presence of food. Ibandronate has a wide therapeutic index and is not metabolized and, therefore, has a low potential for drug interactions. Given its metabolic stability, ibandronate is eliminated from the blood by partitioning into bone (40%‐50%) and through renal clearance (CLR ∼60 mL/min). The CLR of ibandronate is linearly related to creatinine clearance. The sequestration of ibandronate in bone (VD > 90 L) results in a multiphasic elimination (t1/2 range ∼10–60 hours), characterized by the slow release of ibandronate from the bone compartment. The potency of ibandronate and its sequestration into bone allow ibandronate to be developed as oral and intravenous injection formulations that can be administered with convenient extended between‐dose intervals.
Interactions of Prednisolone and Other Immunosuppressants Used in Dual Treatment of Systemic Lupus Erythematosus in Lymphocyte Proliferation Assays
Authors: Kamal Mohamed A. , Jusko William J.
Published: August 2004

Systemic lupus erythematosus is an autoimmune disease primarily affecting women. Currently systemic lupus erythematosus therapy is suboptimal due to adverse effects of immunosuppressants, particularly corticosteroids. This study determines the single effects of prednisolone, dehydroepiandrosterone, bromocriptine, tamoxifen, mycophenolic acid, 2‐chloro‐2′‐deoxyadenosine, azathioprine, and chloroquine on lectin‐stimulated proliferation of human T lymphocytes, as well as determining whetherthere are interactions in the joint effects of prednisolone and these agents. The T lymphocytes from the whole blood of 10 middle‐aged women were stimulated by phytohemagglutinin and cultured with varying drug concentrations. The Hill function was used to evaluate single‐drug response data. Isobolograms were constructed to qualitatively analyze interactions. Parametric analysis based on competitive and noncompetitive interaction models was further applied to quantify the joint interactions and predict steroid‐sparing potential. The surface interaction parameter (ψ) estimated from parametric analysis was in concordance with isobolographic inspection for all interactions studied. All interactions favored the noncompetitive model. Results suggest that dehydroepiandrosterone is additive in its effect with prednisolone, whereas tamoxifen interacts synergistically, both providing steroid‐sparing effects. Novel immunosuppressants such as mycophenolic acid may still provide added pharmacologic benefit during therapy despite a slight antagonistic interaction with prednisolone. These studies help rationalize actual or potential use of other drugs with prednisolone in the treatment of systemic lupus erythematosus.
Simvastatin Does Not Have a Clinically Significant Pharmacokinetic Interaction With Fenofibrate in Humans
Authors: Bergman Arthur J. , Murphy Gail , Burke Joanne , Zhao Jamie J. , Valesky Robert , Liu Lida , Lasseter Kenneth C. , He Weili , Prueksaritanont Thomayant , Qiu Yue , Hartford Alan , Vega Jose M. , Paolini John F.
Published: August 2004

Simvastatin and fenofibrate are both commonly used lipid‐regulating agents with distinct mechanisms of action, and their coadministration may be an attractive treatment for some patients with dyslipidemia. A 2‐period, randomized, open‐label, crossover study was conducted in 12 subjects to determine if fenofibrate and simvastatin are subject to a clinically relevant pharmacokinetic interaction at steady state. In treatment A, subjects received an 80‐mg simvastatin tablet in the morning for 7 days. In treatment B, subjects received a 160‐mg micronized fenofibrate capsule in the morning for 7 days, followed by a 160‐mg micronized fenofibrate capsule dosed together with an 80‐mg simvastatin tablet on days 8 to 14. Because food increases the bioavailability of fenofibrate, each dose was administered with food to maximize the exposure of fenofibric acid. The steady‐state pharmacokinetics (AUC0–24h, Cmax, and tmax) of active and total HMG‐CoA reductase inhibitors, simvastatin acid, and simvastatin were determined following simvastatin administration with and without fenofibrate. Also, fenofibric acid steady‐state pharmacokinetics were evaluated with and without simvastatin. The geometric mean ratios (GMRs) for AUC0–24h (80 mg simvastatin [SV] + 160 mg fenofibrate)/(80 mg simvastatin alone) and 90% confidence intervals (CIs) were 0.88 (0.80, 0.95) and 0.92 (0.82, 1.03) for active and total HMG‐CoA reductase inhibitors. The GMRs and 90% CIs for fenofibric acid (80 mg SV + 160 mg fenofibrate/160 mg fenofibrate alone) AUC0–24h and Cmax were 0.95 (0.88, 1.04) and 0.89 (0.77, 1.02), respectively. Because both the active inhibitor and fenofibric acid AUC GMR 90% confidence intervals fell within the prespecified bounds of (0.70, 1.43), no clinically significant pharmacokinetic drug interaction between fenofibrate and simvastatin was concluded in humans. The coadministration of simvastatin and fenofibrate in this study was well tolerated.
Pharmacokinetics and Pharmacodynamic Response of Methylprednisolone in Premenopausal Renal Transplant Recipients
Authors: Tornatore Kathleen M. , Gilliland‐Johnson Kristin K. , Farooqui Mahfooz , Reed Kris A. , Venuto Rocco C.
Published: August 2004

Chronic glucocorticoid therapy is prescribed in renal transplant recipients according to empiric dose‐tapering schedules, which assume a similar pharmacologic response in men and women. The study objectives were (a) to compare the pharmacokinetics of methylprednisolone in premenopausal renal transplant recipients with previously studied male counterparts and (b) to describe the pharmacodynamic response of the hypothalamic‐pituitary‐adrenal axis during chronic steroid therapy. Thirteen stable premenopausal subjects (ages 30 to ≥ 49 years) receiving chronic glucocorticoid therapy were evaluated for methylprednisolone, cortisol, and adrenocorticotropin hormone (ACTH) over 24 hours after an intravenous infusion of methylprednisolone sodium succinate. Most patients were evaluated during the luteal phase of the menstrual cycle. Pharmacokinetic parameters of methylprednisolone with cortisol and ACTH responses were determined. Results were compared to counterpart male subjects who participated in a prior study. The total clearance of methylprednisolone for the female subjects was 15.6 ±5.99 L/ h compared to the males with 21.5 ± 8.67 L/h (P < .05). When normalized for total or lean body weight, no significant difference was noted (P = .614). A 3‐fold interpatient variation in weight‐adjusted clearance was noted for female subjects. Dose‐normalized methylprednisolone a AUC was greater in women (66.1 ± 19.8 ng•h/mL) than men (46.4 ± 19.7 ng•h/ mL) (P = .174). Total cortisol AUC was not different between groups (P = .599). Despite chronic steroid therapy, 9 of 13 women had a normal cortisol profile and an ACTH AUC of 299 ± 102 pg•h/mL. It was concluded that methylprednisolone clearance in women was significantly slower compared to men. When drug clearance was normalized for total and lean body weight, no gender difference was noted. These findings are in contrast to prior data indicating a more rapid methylprednisolone clearance in healthy women. These findings suggest that doses of glucocorticoids should be prescribed on a milligram/kilogram basis instead of empiric dosing schedules.
A Pharmacokinetic Study of the Combined Administration of Amiodarone and Ximelagatran, an Oral Direct Thrombin Inhibitor
Authors: Teng Renli , Sarich Troy C. , Eriksson Ulf G. , Hamer Jennifer E. , Gillette Stephen , Schützer Kajs‐Marie , Carlson Glenn F. , Kowey Peter R.
Published: August 2004

The oral direct thrombin inhibitor ximelagatran is being developed for the prevention and treatment of thromboembolism. This single‐blind, randomized, placebo‐controlled, parallel‐group study investigated the potential for the interaction of ximelagatran (36 mg every 12 hours for 8 days, measured as its active form melagatran in blood) and amiodarone (single 600‐mg oral dose on day 4) in healthy male subjects (n = 26). For amiodarone + ximelagatran versus amiodarone + placebo, geometric mean ratios (90% confidence intervals for amiodarone AUC0–120 and Cmax were 0.87 (0.69–1.08) and 0.86 (0.66–1.11), respectively. For desethylamiodarone, the principal metabolite of amiodarone, the corresponding ratios were 1.00 (0.89–1.12) for AUC0–120 and 0.92 (0.77–1.09) for Cmax. The geometric mean ratios (90% confidence intervals) for ximelagatran + amiodarone versus ximelagatran were 1.21 (1.17–1.25) for melagatran AUC0–12 and 1.23 (1.18–1.28) for melagatran Cmax. These confidence intervals were within or only slightly outside the interval, suggesting no interaction (0.8–1.25 for the effect of amiodarone on melagatran and 0.7–1.43 for the effect of melagatran on amiodarone or desethylamiodarone). Amiodarone did not affect the concentration‐effect relationship of melagatran on activated partial thromboplastin time. Ximelagatran was well tolerated when coadministered with a single dose of amiodarone. Evaluation of the safety of the combination is needed to confirm that the relatively small pharmacokinetic changes in this study are of no clinical significance.
Lack of Weight‐Based Dose Dependency and Intraindividual Variability of Omeprazole for CYP2C19 Phenotyping
Authors: Kim Myong‐Jin , Nafziger Anne N. , Zhang Yanhua , Sellers Edward M. , Gaedigk Andrea , Bertino Joseph S.
Published: August 2004

To determine if dose dependency occurs with 2 weight‐based single doses of omeprazole in a phenotyping study as well as to quantitate 3‐month intraindividual variability of CYP2C19 activity, 24 Caucasian subjects with body weights from 45 to 66 kg and 67 to 90 kg received single oral 30‐mg and 40‐mg doses of omeprazole, respectively. Female subjects were phenotyped during the mid‐follicular and mid‐luteal phases of their menstrual cycles for 3 complete cycles. Male subjects were phenotyped every 14 days for 12 weeks. Subjects with a body weight between 45 and 66 kg received an additional 40‐mg omeprazole single dose on visit 7. The 2‐hour postdose plasma concentration ratio of omeprazole to 5′‐hydroxyomeprazole was used as a measure of CYP2C19 activity. The percent coefficient of variation (CV%) of omeprazole phenotyping ranged from 6.3% to 51.3% (median = 18.5%, interquartile range = 14.8%‐23.5%). Weight‐based single doses of omeprazole for CYP2C19 phenotyping did not exhibit dose dependency. Therefore, a weight‐based approach may improve the quantitation of omeprazole/metabolites.
Identification of talin head domain as an immunodominant epitope of the antiplatelet antibody response in patients with HIV-1-associated thrombocytopenia
Authors: Koefoed Klaus , Ditzel Henrik J.
Published: August 2004

HIV-1-associated thrombocytopenia (HIV-1-ITP) is a common complication of HIV-1 infection, frequently caused by increased peripheral platelet destruction mediated by antiplatelet antibodies (Abs) and/or platelet-bound immune complexes. Little is known about the specificity of the antiplatelet Abs at a molecular level. Here, we used immunoglobulin G (IgG) phage-display libraries generated from 3 HIV-1-ITP patients to isolate a large panel of human monoclonal antiplatelet Abs by selection on unfixed platelets. The platelet antigen recognized by all the cloned Abs was identified to be the talin head domain (talin-H), a cleavage product of talin that can be generated by platelet activation or HIV-1 protease. Talin-H was found in HIV-1-ITP-circulating immune complexes, and antitalin Abs were detected in HIV-1-ITP sera but not in controls. The cloned anti-talin-H IgGs were highly somatically mutated, indicative of an antigen-driven, affinity-matured response. These findings suggest that talin-H Ab may be a marker of HIV-1-ITP elicited due to exposure of immunodominant epitopes on talin-H as a result of a disease-related process. Abs to talin-H and related immune complexes (ICs) may contribute to HIV-1-ITP. (Blood. 2004;104:4054-4062)
RelB regulates human dendritic cell subset development by promoting monocyte intermediates
Authors: Platzer Barbara , Jörgl Almut , Taschner Sabine , Höcher Bernhard , Strobl Herbert
Published: August 2004

In humans, epithelial Langerhans cells (LCs) and monocyte-derived/interstitial dendritic cells (DCs) constitute 2 myeloid DC sublineages. Molecular mechanisms involved in their development from common myeloid progenitors remain poorly defined. Here we demonstrate that the nuclear factor-κB (NF-κB) transcription factor RelB regulates the generation of monocytic CD14+CD11b+ precursors of interstitial DCs from human hematopoietic progenitors. RelB overexpression promoted, whereas endogenous RelB inhibition (by p100ΔN) blocked, precursor cell development along this DC subset pathway. RelB inhibition specifically arrested precursor progression from CD14loCD11b- to CD14+CD11b+ stages. Precursors were still capable of LC and granulocyte differentiation but were defective in macrophage–colony-stimulating factor (M-CSF)–dependent monocyte/macrophage differentiation. RelB inhibition markedly differed from classical NF-κB signaling inhibition because IκBα superrepressor (IκBα-SR), but not p100ΔN, impaired LC/DC differentiation, DC adhesion, and progenitor cell proliferation. Although RelB up-regulation and nuclear translocation are regarded as hallmarks of human myeloid DC maturation, ectopic RelB overexpression failed to promote DC maturation. Our results suggest that RelB regulates human monopoiesis and monocyte-derived DC subset development.
Impaired CD40L signaling is a cause of defective IL-12 and TNF-α production in Sézary syndrome: circumvention by hexameric soluble CD40L
Authors: French Lars E. , Huard Bertrand , Wysocka Maria , Shane Ryan , Contassot Emmanuel , Arrighi Jean-François , Piguet Vincent , Calderara Silvio , Rook Alain H.
Published: August 2004

Sézary syndrome (SzS) is an advanced form of cutaneous T-cell lymphoma characterized by peripheral blood involvement, impaired cell-mediated immunity, and T-helper 1 (TH1) cytokine production. To understand the mechanism of these defects, we studied the expression and function of CD40L in peripheral blood mononuclear cells (PBMCs) of patients with SzS. We found that PBMCs of patients with SzS have a defect in interleukin-12 (IL-12) and tumor necrosis factor-α (TNF-α) production upon anti-CD3 stimulation and that tumor CD4+ T lymphocytes have a specific defect in CD40L induction after anti-CD3 ligation in vitro. This defect may explain the poor IL-12 production, because IL-12 production by anti-CD3-stimulated PBMCs was dependent on CD40L in healthy donors. The observed defect in tumor cell CD40L expression appears to be due to inappropriate T-cell signaling upon CD3 ligation, because expression of other T-cell activation antigens such as CD25, and to a lesser extent CD69, are also impaired on tumor cells. Importantly however, the inability of SzS PBMCs to appropriately produce IL-12 and TNF-α could be restored by recombinant hexameric CD40L. Taken together, our results demonstrate that impaired IL-12 and TNF-α production in SzS is associated with defective CD4+ T lymphocyte CD40L induction and indicate that CD40L may have therapeutic potential in SzS. (Blood. 2005;105:219-225)
β2-glycoprotein I–dependent lupus anticoagulant highly correlates with thrombosis in the antiphospholipid syndrome
Authors: de Laat H. Bas , Derksen Ronald H.W.M. , Urbanus Rolf T. , Roest Mark , de Groot Philip G.
Published: August 2004

The antiphospholipid syndrome is characterized by the presence of antiphospholipid antibodies in plasma of patients with thromboembolic complications. A major problem in defining the syndrome is that serologic assays to detect antiphospholipid antibodies have a low specificity. We recently published a method that specifically detects lupus anticoagulant (LAC) caused by anti–β2-glycoprotein I antibodies. Here, we studied the clinical relevance of detecting β2-glycoprotein I–dependent LAC. Plasma samples were collected from 198 patients with autoimmune diseases. In those samples with a positive partial thromboplastin time–lupus anticoagulant (PTT-LA), a modified activated partial thromboplastin time (aPTT)–based LAC test was performed with cardiolipin as confirming agent. Twenty-five of 58 patients with an aPTT-based LAC were dependent on the presence of anti–β2-glycoprotein I antibodies. Presence of β2-glycoprotein I–dependent LAC was almost completely associated with a history of thromboembolic complications (odds ratio, 42.3; 95% confidence interval, 194.3-9.9). An increased frequency of thrombosis was not found in 33 patients with LAC independent of anti–β2-glycoprotein I antibodies (odds ratio, 1.6; 95% confidence interval, 3.9-0.8). The use of an LAC assay with cardiolipin as confirming agent strongly improves the detection of patients at risk of thrombosis. Our findings suggest that anti–β2-glycoprotein I antibodies with LAC activity are antibodies that are responsible for the thromboembolic complications in the antiphospholipid syndrome.
Evidence that genetic deletion of the TNF receptor p60 or p80 in macrophages modulates RANKL-induced signaling
Authors: Takada Yasunari , Aggarwal Bharat B.
Published: August 2004

In the current report, we investigated the possibility of a cross-talk between receptor activator of NF-κB ligand (RANKL) and tumor necrosis factor α (TNF-α) using macrophage cell lines derived from wild-type mice and from mice with genetic deletion of the type 1 TNF receptor (p60-/-), the type 2 TNF receptor (p80-/-), or both receptors (p60-/-p80-/-). Deletion of TNF receptors sensitized the cells to RANKL-induced NF-κB activation, in order from least to most sensitive of p60-/- less than p80-/- less than p60-/-p80-/-. The effect on nuclear factor-κB (NF-κB) activation correlated with RANKL-induced IκBα kinase activation. Deletion of both TNF receptors also potentiated RANKL-induced c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1 and 2 (ERK1/2), and p38 mitogen-activated protein kinase (MAPK) activations in a dose- and time-dependent manner. Nitric oxide (NO) production and expression of inducible NO synthase (iNOS) and cyclooxygenase 2 (COX-2) induced by RANKL was also maximally induced in double knock-out cells. RANKL had no effect on the proliferation of wild-type cells, but deletion of TNF receptors induced growth modulatory effects. We also found that tumor necrosis factor (TNF) receptor-associated factor 6 (TRAF6), which mediates RANKL signaling, was constitutively bound to RANK in TNF receptor-deleted cells but not in wild-type cells, and this binding was enhanced by RANKL. Overall our results show that RANKL signaling is modulated by the TNF receptors and thus provide evidence of cross-talk between the receptors of 2 cytokines. (Blood. 2004;104: 4113-4121)
Regulation of stem cell factor receptor signaling by Cbl family proteins (Cbl-b/c-Cbl)
Authors: Zeng Shan , Xu Zhiheng , Lipkowitz Stan , Longley Jack B.
Published: August 2004

Activation of the KIT receptor tyrosine kinase contributes to the pathogenesis of several human diseases, but the mechanisms regulating KIT signaling have not been fully characterized. Here, we show that stem cell factor (SCF), the ligand for KIT, induces the interaction between KIT and Cbl proteins and their mutual degradation. Upon SCF stimulation, KIT binds to and induces the phosphorylation of Cbl proteins, which in turn act as E3 ligases, mediating the ubiquitination and degradation of KIT and themselves. Tyrosine kinase binding and RING finger domains of Cbl are essential for Cbl-mediated ubiquitination and degradation of KIT. We propose a negative feedback loop controlling the SCF-KIT signaling pathway, in which SCF activates KIT. The activated KIT in turn induces phosphorylation and activation of Cbl proteins. The Cbl proteins then bind and direct the degradation of activated KIT, leading to down-regulation of KIT signaling. (Blood. 2005;105:226-232)
p38 MAPK activation controls the TLR3-mediated up-regulation of cytotoxicity and cytokine production in human NK cells
Authors: Pisegna Simona , Pirozzi Gianluca , Piccoli Mario , Frati Luigi , Santoni Angela , Palmieri Gabriella
Published: August 2004

Natural killer (NK) cells are a component of the innate immunity against viral infections through their rapid cytotoxic activity and cytokine production. Although the synthetic double-stranded (ds) RNA polyinosinic-polycytidylic acid (poly I:C), a mimic of a common product of viral infections, is known to rapidly up-regulate their in vivo functions, NK cell ability to directly respond to dsRNA is still mostly unknown. Our results show that treatment with poly I:C significantly up-regulates both natural and CD16-mediated cytotoxicity of highly purified human NK cells. Poly I:C also induces the novel capability of producing CXCL10 chemokine in human NK cells and synergistically enhances interferon-γ (IFN-γ) production induced by either adaptive or innate cytokines. In accordance with the expression of Toll-like receptor-3 (TLR3) and of TRIF/TICAM-1 adaptor, poly I:C stimulation induces the activation of interferon regulatory factor-3 (IRF-3) transcription factor and of p38 mitogen-activated protein kinase (MAPK) in human NK cells. Finally, we demonstrate that p38 MAPK activity is required for the dsRNA-dependent enhancement of cytotoxicity and CXCL10 production. The occurrence of dsRNA-induced signaling and functional events closely correlates with the TLR3 mRNAprofile in different NK cell populations. Taken together, these data identify p38 as a central component of NK cell ability to directly respond to dsRNA pathogen-associated molecular pattern (PAMP).
Expression of Rgmc, the murine ortholog of hemojuvelin gene, is modulated by development and inflammation, but not by iron status or erythropoietin
Authors: Krijt Jan , Vokurka Martin , Chang Ko-Tung , Nečas Emanuel
Published: August 2004

Mutations of hepcidin (HAMP) and hemo-juvelin (HJV) genes have been recently demonstrated to result in juvenile hemochromatosis. Expression of HAMP is regulated by iron status or infection, whereas regulation of HJV is yet unknown. Using quantitative real-time polymerase chain reaction, we compared expression of Hamp and Rgmc (the murine ortholog of HJV) in livers of mice treated with iron, erythropoietin, or lipopolysaccharide (LPS), as well as during fetal and postnatal development. Iron overload increased Hamp expression without effect on Rgmc mRNA. Erythropoietin decreased Hamp mRNA, but Rgmc expression was unchanged. Hamp mRNA level decreased after birth by 4 orders of magnitude, without significant changes in Rgmc expression. Administration of LPS elevated Hamp mRNA levels, while markedly decreasing hepatic Rgmc mRNA levels (to ∼5% after 6 hours). The responses of Hamp and Rgmc were quite different and suggested that human HJV expression could be modulated by inflammation.
Site-specific mutagenesis of Drosophila proliferating cell nuclear antigen enhances its effects on calf thymus DNA polymerase δ
Authors: Mozzherin Dmitry Ju , McConnell Maeve , Miller Holly , Fisher Paul A
Published: August 2004

Background

We and others have shown four distinct and presumably related effects of mammalian proliferating cell nuclear antigen (PCNA) on DNA synthesis catalyzed by mammalian DNA polymerase δ(pol δ). In the presence of homologous PCNA, pol δ exhibits 1) increased absolute activity; 2) increased processivity of DNA synthesis; 3) stable binding of synthetic oligonucleotide template-primers (t1/2 of the pol δ•PCNA•template-primer complex ≥2.5 h); and 4) enhanced synthesis of DNA opposite and beyond template base lesions. This last effect is potentially mutagenic in vivo. Biochemical studies performed in parallel with in vivo genetic analyses, would represent an extremely powerful approach to investigate further, both DNA replication and repair in eukaryotes.

Results

Drosophila PCNA, although highly similar in structure to mammalian PCNA (e.g., it is >70% identical to human PCNA in amino acid sequence), can only substitute poorly for either calf thymus or human PCNA (~10% as well) in affecting calf thymus pol δ. However, by mutating one or only a few amino acids in the region of Drosophila PCNA thought to interact with pol δ, all four effects can be enhanced dramatically.

Conclusions

Our results therefore suggest that all four above effects depend at least in part on the PCNA-pol δ interaction. Moreover unlike mammals, Drosophila offers the potential for immediate in vivo genetic analyses. Although it has proven difficult to obtain sufficient amounts of homologous pol δ for parallel in vitro biochemical studies, by altering Drosophila PCNA using site-directed mutagenesis as suggested by our results, in vitro biochemical studies may now be performed using human and/or calf thymus pol δ preparations.
Selection and validation of endogenous reference genes using a high throughput approach
Authors: Jin Ping , Zhao Yingdong , Ngalame Yvonne , Panelli Monica C , Nagorsen Dirk , Monsurró Vladia , Smith Kina , Hu Nan , Su Hua , Taylor Phil R , Marincola Francesco M , Wang Ena
Published: August 2004

Background

Endogenous reference genes are commonly used to normalize expression levels of other genes with the assumption that the expression of the former is constant in different tissues and in different physiopathological conditions. Whether this assumption is correct it is, however, still matter of debate. In this study, we searched for stably expressed genes in 384 cDNA array hybridization experiments encompassing different tissues and cell lines.

Results

Several genes were identified whose expression was highly stable across all samples studied. The usefulness of 8 genes among them was tested by normalizing the relative gene expression against test genes whose expression pattern was known. The range of accuracy of individual endogenous reference genes was wide whereas consistent information could be obtained when information pooled from different endogenous reference genes was used.

Conclusions

This study suggests that even when the most stably expressed genes in array experiments are used as endogenous reference, significant variation in test gene expression estimates may occur and the best normalization is achieved when data from several endogenous reference genes are pooled together to minimize minimal but significant variation among samples. We are presently optimizing strategies for the preparation of endogenous reference gene mixtures that could yield information comparable to that of data pooled from individual endogenous reference gene normalizations.
Epidemiological evidence of higher susceptibility to vCJD in the young
Authors: Boëlle Pierre-Yves , Cesbron Jean-Yves , Valleron Alain-Jacques
Published: August 2004

Background

The strikingly young age of new variant Creutzfeldt-Jacob disease (vCJD) cases remains unexplained. Age dependent susceptibility to infection has been put forward, but differential dietary exposure to contaminated food products in the UK population according to age and sex during the bovine spongiform encephalopathy (BSE) epidemic may provide a simpler explanation.

Methods

Using recently published estimates of dietary exposure in mathematical models of the epidemiology of the new variant Creutzfeldt Jacob disease (vCJD), we examine whether the age characteristics of vCJD cases may be reproduced.

Results

The susceptibility/exposure risk function has likely peaked in adolescents and was followed by a sharp decrease with age, evocative of the profile of exposure to bovine material consumption according to age. However, assuming that the risk of contamination was proportional to exposure, with no age dependent susceptibility, the model failed to reproduce the observed age characteristics of the vCJD cases: The predicted cumulated proportion of cases over 40 years was 48%, in strong disagreement with the observed 10%. Incorporating age dependent susceptibility led to a cumulated proportion of cases over 40 years old of 12%.

Conclusions

This analysis provides evidence that differential dietary exposure alone fails to explain the pattern of age in vCJD cases. Decreasing age related susceptibility is required to reproduce the characteristics of the age distribution of vCJD cases.
Patterns of geohelminth infection, impact of albendazole treatment and re-infection after treatment in schoolchildren from rural KwaZulu-Natal/South-Africa
Authors: Saathoff Elmar , Olsen Annette , Kvalsvig Jane D , Appleton Chris C
Published: August 2004

Background

Geohelminth infection is a major health problem of children from rural areas of developing countries. In an attempt to reduce this burden, the Department of Health of the province of KwaZulu-Natal (KZN) established in 1998 a programme for helminth control that aimed at regularly treating primary school children for schistosomiasis and intestinal helminths. This article describes the baseline situation and the effect of treatment on geohelminth infection in a rural part of the province.

Methods

Grade 3 schoolchildren from Maputaland in northern KZN were examined for infections with hookworm, Ascaris lumbricoides, and Trichuris trichiura, treated twice with 400 mg albendazole and re-examined several times over one year after the first treatment in order to assess the impact of treatment and patterns of infection and re-infection.

Results

The hookworm prevalence in the study population (83.2%) was considerably higher than in other parts of the province whereas T. trichiura and especially A. lumbricoides prevalences (57.2 and 19.4%, respectively) were much lower than elsewhere on the KZN coastal plain. Single dose treatment with albendazole was very effective against hookworm and A. lumbricoides with cure rates (CR) of 78.8 and 96.4% and egg reduction rates (ERR) of 93.2 and 97.7%, respectively. It was exceptionally ineffective against T. trichiura (CR = 12.7%, ERR = 24.8%). Re-infection with hookworm and A. lumbricoides over 29 weeks after treatment was considerable but still well below pre-treatment levels.

Conclusion

High geohelminth prevalences and re-infection rates in the study population confirm the need for regular treatment of primary school children in the area. The low effectiveness of single course albendazole treatment against T. trichiura infection however demands consideration of alternative treatment approaches.
Tamoxifen and the Rafoxifene analog LY117018: their effects on arachidonic acid release from cells in culture and on prostaglandin I2production by rat liver cells
Authors: Levine Lawrence
Published: August 2004

Background

Tamoxifen is being used successfully to treat breast cancer. However, tamoxifen also increases the risk of developing endometrial cancer in postmenopausal women. Raloxifene also decreases breast cancer in women at high risk and may have a lower risk at developing cancer of the uterus. Tamoxifen has been shown to stimulate arachidonic acid release from rat liver cells. I have postulated that arachidonic acid release from cells may be associated with cancer chemoprevention.

Methods

Rat liver, rat glial, human colon carcinoma and human breast carcinoma cells were labelled with [3H] arachidonic acid. The release of the radiolabel from these cells during incubation with tamoxifen and the raloxifene analog LY117018 was measured. The prostaglandin I2 produced during incubation of the rat liver cells with μM concentrations of tamoxifen and the raloxifene analog was quantitatively estimated.

Results

Tamoxifen is about 5 times more effective than LY117018 at releasing arachidonic acid from all the cells tested. In rat liver cells only tamoxifen stimulates basal prostaglandin I2 production and that induced by lactacystin and 12-O-tetradecanoyl-phorbol-13-acetate. LY117018, however, blocks the tamoxifen stimulated prostaglandin production. The stimulated prostaglandin I2 production is rapid and not affected either by preincubation of the cells with actinomycin or by incubation with the estrogen antagonist ICI-182,780.

Conclusions

Tamoxifen and the raloxifene analog, LY117018, may prevent estrogen-independent as well as estrogen-dependent breast cancer by stimulating phospholipase activity and initiating arachidonic acid release. The release of arachidonic acid and/or molecular reactions that accompany that release may initiate pathways that prevent tumor growth. Oxygenation of the intracellularly released arachidonic acid and its metabolic products may mediate some of the pharmacological actions of tamoxifen and raloxifene.
Frequency of cancer in children residing in Mexico City and treated in the hospitals of the Instituto Mexicano del Seguro Social (1996–2001)
Authors: Juárez-Ocaña Servando , González-Miranda Guadalupe , Mejía-Aranguré Juan Manuel , Rendón-Macías Mario Enrique , Martínez-García María del Carmen , Fajardo-Gutiérrez Arturo
Published: August 2004

Background

The objective of this article is to present the frequency of cancer in Mexican children who were treated in the hospitals of the Instituto Mexicano del Seguro Social in Mexico City (IMSS-MC) in the period 1996–2001.

Methods

The Registry of Cancer in Children, started in 1996 in the IMSS-MC, is an on-going, prospective register. The data from 1996 through 2001 were analyzed and the different types of cancer were grouped according to the International Classification for Cancer in Children (ICCC). From this analysis, the general and specific frequencies by age and by sex were obtained for the different groups of neoplasms. Also, the frequency of the stage of the disease that had been diagnosed in cases of children with solid tumors was obtained.

Results

A total of 1,702 new cases of children with cancer were registered, with the male/female ratio at 1.1/1. Leukemias had the highest frequency with 784 cases (46.1%) and, of these, acute lymphoblastic leukemias were the most prevalent with 614 cases (78.3%). Thereafter, in descending order of frequency, were tumors of the central nervous system (CNST) with 197 cases (11.6%), lymphomas with 194 cases (11.4%), germinal cell tumors with 110 cases (6.5%), and bone tumors with 97 cases (5.7%). The highest frequency of cancer was found in the group of one to four year-olds that had 627 cases (36.8%). In all the age groups, leukemias were the most frequent. In the present work, the frequency of Hodgkin's disease (~4%) was found to be lower than that (~10%) in previous studies and the frequency of tumors of the sympathetic nervous system was low (2.3%). Of those cases of solid tumors for which the stage of the disease had been determined, 66.9% were diagnosed as being Stage III or IV.

Conclusions

The principal cancers in the children treated in the IMSS-MC were leukemias, CNST, and lymphomas, consistent with those reported by developed countries. A 2.5-fold reduction in the frequency of Hodgkin's disease was found. Of the children, the stage of whose disease had been determined, two thirds were diagnosed as having advanced stages of the disease.
Mental health first aid training in a workplace setting: A randomized controlled trial [ISRCTN13249129]
Authors: Kitchener Betty A , Jorm Anthony F
Published: August 2004

Background

The Mental Health First Aid training course was favorably evaluated in an uncontrolled trial in 2002 showing improvements in participants' mental health literacy, including knowledge, stigmatizing attitudes, confidence and help provided to others. This article reports the first randomized controlled trial of this course.

Methods

Data are reported on 301 participants randomized to either participate immediately in a course or to be wait-listed for 5 months before undertaking the training. The participants were employees in two large government departments in Canberra, Australia, where the courses were conducted during participants' work time. Data were analyzed according to an intention-to-treat approach.

Results

The trial found a number of benefits from this training course, including greater confidence in providing help to others, greater likelihood of advising people to seek professional help, improved concordance with health professionals about treatments, and decreased stigmatizing attitudes. An additional unexpected but exciting finding was an improvement in the mental health of the participants themselves.

Conclusions

The Mental Health First Aid training has shown itself to be not only an effective way to improve participants' mental health literacy but also to improve their own mental health. It is a course that has high applicability across the community.