Blockade of cysteinyl leukotriene-1 receptors suppresses airway remodelling in mice overexpressing GATA-3

BACKGROUND

We demonstrated previously that GATA-3 overexpression markedly enhanced allergen-induced airway inflammation and airway remodelling, including subepithelial fibrosis, and smooth muscle cell hyperplasia, in transgenic mice.

OBJECTIVE

Because cysteinyl leukotrienes (cysLTs) have been shown to be involved in such structural changes, the effects of a specific cysLT1 receptor antagonist, montelukast, were evaluated in a mouse model of chronic asthma.

METHODS

GATA-3-overexpressing mice and wild-type Balb/c mice were sensitized and repeatedly challenged by ovalbumin (OVA) or saline. The effects of montelukast on the development of airway remodelling were compared between the two mouse genotypes.

RESULTS

CysLTs in the lung were increased after repeated allergen challenges, and significantly enhanced in GATA-3-overexpressing mice. The enhanced cysLT levels were accompanied by the development of eosinophilia, smooth muscle cell hyperplasia, and increased stromal cell-derived factor-1 gene expression with a small increase in pro-collagen gene expression in OVA-challenged GATA-3-overexpressing mice, but not in wild-type mice. Montelukast significantly decreased lung cysLT levels and inhibited the GATA-3-overexpression-related airway remodelling, potently preventing smooth muscle cell hyperplasia, but partially suppressed the increased pro-collagen gene expression and eosinophilic inflammation. Increases in the levels of IL-4, IL-5, IL-13, and eotaxin in bronchial lavage and TGF-β gene expression in the lungs were induced by OVA in both mouse genotypes. Montelukast treatment also significantly reduced these levels to the levels seen after saline challenges in GATA-3-overexpressing mice.

CONCLUSION

Montelukast efficaciously prevented airway inflammation and remodelling in a GATA-3-overexpression antigen challenge mouse model by decreasing the cysLT-driven Th2 cytokine cycle of amplification of airway pathologies.

Inverse association between soy intake and non-Hodgkin lymphoma risk among women: a case-control study in Japan

BACKGROUND

Non-Hodgkin lymphoma (NHL) is one of the common malignant tumors worldwide. Environmental factors, such as diet have an important association with the risk of cancer. Although soy intake has been associated with a reduced risk of several cancers, its association with NHL is not known.

PATIENTS AND METHODS

We evaluated the association between soy consumption and risk of NHL by conducting a hospital-based case-control study in 302 patients with NHL and 1510 age- and sex-matched control subjects. Odds ratio (OR) and 95% confidence intervals (CIs) for groups with moderate (27-51 g/day) to high (>51 g/day) relative to low (<27 g/day) intake were calculated using multivariate conditional logistic regression model.

RESULTS

Soy intake was significantly associated with a reduced risk of NHL in women but not in men (OR [95% CI] for moderate and high intake: women, 0.64 [0.42-1.00] and 0.66 [0.42-1.02], respectively; men, 1.40 [0.87-2.24] and 1.33 [0.82-2.15], respectively; P-interaction = 0.02). This finding appeared consistent across NHL subtypes.

CONCLUSION

These results indicate the potential importance of certain ingredients in soy for lymphomagenesis. Further studies to evaluate the mechanism behind the association between soy intake and lymphomagenesis are warranted.

Pre-transplant imatinib-based therapy improves the outcome of allogeneic hematopoietic stem cell transplantation for BCR-ABL-positive acute lymphoblastic leukemia

A high complete remission (CR) rate has been reported in newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL) following imatinib-based therapy. However, the overall effect of imatinib on the outcomes of allogeneic hematopoietic stem cell transplantation (allo-HSCT) is undetermined. Between 2002 and 2005, 100 newly diagnosed adult patients with Ph+ALL were registered to a phase II study of imatinib-combined chemotherapy (Japan Adult Leukemia Study Group Ph+ALL202 study) and 97 patients achieved CR. We compared clinical outcomes of 51 patients who received allo-HSCT in their first CR (imatinib cohort) with those of 122 historical control patients in the pre-imatinib era (pre-imatinib cohort). The probability of overall survival at 3 years after allo-HSCT was 65% (95% confidence interval (CI), 49-78%) for the imatinib cohort and 44% (95% CI, 35-52%) for the pre-imatinib cohort. Multivariate analysis confirmed that this difference was statistically significant (adjusted hazard ratio, 0.44, P=0.005). Favorable outcomes of the imatinib cohort were also observed for disease-free survival (P=0.007) and relapse (P=0.002), but not for non-relapse mortality (P=0.265). Imatinib-based therapy is a potentially useful strategy for newly diagnosed patients with Ph+ALL, not only providing them more chance to receive allo-HSCT, but also improving the outcome of allo-HSCT.

Stimulation of the frontal eye field reveals persistent effective connectivity after controlled behavior

Our ability to choose nonhabitual controlled behavior instead of habitual automatic behavior is based on a flexible control mechanism subserved by neural activity representing the behavior-guiding rule. However, it has been shown that the behavior slows down more when switching from controlled to automatic behavior than vice versa. Here we show that persistent effective connectivity of the neural network after execution of controlled behavior is responsible for the behavioral slowing on a subsequent trial. We asked normal human subjects to perform a prosaccade or antisaccade task based on a cue and examined the effective connectivity of the neural network based on the pattern of neural impulse transmission induced by stimulation of the frontal eye field (FEF). Effective connectivity during the task preparation period was dependent on the task that subjects had performed on the previous trial, regardless of the upcoming task. The strength of this persistent effective connectivity was associated with saccade slowing especially on trials after controlled antisaccade. In contrast, the pattern of regional activation changed depending on the upcoming task regardless of the previous task and the decrease in activation was associated with errors in upcoming antisaccade task. These results suggest that the effective connectivity examined by FEF stimulation reflects a residual functional state of the network involved in performance of controlled antisaccade and its persistence may account for the behavioral slowing on the subsequent trial.

Reactive mechanism of cognitive control system

The prefrontal cortex (PFC) is thought to modulate the neural network state in favor of the processing of task-relevant sensory information prior to the presentation of sensory stimuli. However, this proactive control mechanism cannot always optimize the network state because of intrinsic fluctuation of neural activity upon arrival of sensory information. In the present study, we have investigated an additional control mechanism, in which the control process to regulate the behavior is adjusted to the trial-by-trial fluctuation in neural representations of sensory information. We asked normal human subjects to perform a variant of the Stroop task. Using functional magnetic resonance imaging, we isolated cognitive conflict at a sensory processing stage on a single-trial basis by calculating the difference in activation between task-relevant and task-irrelevant sensory areas. Activation in the dorsolateral PFC (DLPFC) covaried with the neural estimate of sensory conflict only on incongruent trials. Also, the coupling between the DLPFC and anterior cingulate cortex (ACC) was tighter on high-sensory conflict trials with fast response. The results suggest that although detection of sensory conflict is achieved by the DLPFC, online behavioral adjustment is achieved by interactive mechanisms between the DLPFC and ACC.

Effect of radiation monitoring method and formula differences on estimated physician dose during percutaneous coronary intervention

BACKGROUND

Currently, one or two dosimeters are used to monitor radiation exposure in most cardiac laboratories. In addition, several different formulas are used to convert exposure data into an effective dose (ED).

PURPOSE

To clarify the effect of monitoring methods and formula selection on the estimated ED for physicians during percutaneous coronary interventions (PCIs).

MATERIAL AND METHODS

The ED of physicians during cardiac catheterization was determined using an optically stimulated luminescence dosimeter (Luxel badge). Two Luxel badges were worn: one beneath a personal lead apron (0.35-mm lead equivalent) at the chest and one outside of the apron at the neck.

RESULTS

The difference in the average ED of seven physicians was approximately fivefold (range 1.13-5.43 mSv/year) using the six different formulas in the clinical evaluation. The estimated physician ED differed markedly according to both the monitoring method and formula selected.

CONCLUSION

ED estimation is dependent on both the monitoring method and the formula used. Therefore, it is important that comparisons among laboratories are based on the same monitoring method and same formula for calculating the ED.

DU-176b, a potent and orally active factor Xa inhibitor: in vitro and in vivo pharmacological profiles

BACKGROUND

Factor Xa (FXa), a key serine protease that converts prothrombin to thrombin in the coagulation cascade, is a promising target enzyme for the prophylaxis and treatment of thromboembolic diseases. DU-176b is a novel antithrombotic agent that directly inhibits FXa activity.

OBJECTIVE

To evaluate the in vitro pharmacological profiles and in vivo effects of DU-176b in animal models of thrombosis and bleeding.

METHODS

In vitro, FXa inhibition, specificity and anticoagulant activities were examined. Oral absorption was studied in rats and cynomolgus monkeys. In vivo effects were studied in rat and rabbit models of venous thrombosis and tail bleeding.

RESULTS

DU-176b inhibited FXa with Ki values of 0.561 nm for free FXa, 2.98 nm for prothrombinase, and exhibited >10 000-fold selectivity for FXa. In human plasma, DU-176b doubled prothrombin time and activated partial thromboplastin time at concentrations of 0.256 and 0.508 microm, respectively. DU-176b did not impair platelet aggregation by ADP, collagen or U46619. DU-176b was highly absorbed in rats and monkeys, as demonstrated by more potent anti-Xa activity and higher drug concentration in plasma following oral administration than a prototype FXa inhibitor, DX-9065a. In vivo, DU-176b dose-dependently inhibited thrombus formation in rat and rabbit thrombosis models, although bleeding time in rats was not significantly prolonged at an antithrombotic dose.

CONCLUSIONS

DU-176b is a more potent and selective FXa inhibitor with high oral bioavailability compared with its prototype, DX-9065a. DU-176b represents a promising new anticoagulant for the prophylaxis and treatment of thromboembolic diseases.

Degradation of PEP-19, a calmodulin-binding protein, by calpain is implicated in neuronal cell death induced by intracellular Ca2+ overload

Excessive elevation of intracellular Ca2+ levels and, subsequently, hyperactivation of Ca2+/calmodulin-dependent processes might play an important role in the pathologic events following cerebral ischemia. PEP-19 is a neuronally expressed polypeptide that acts as an endogenous negative regulator of calmodulin by inhibiting the association of calmodulin with enzymes and other proteins. The aims of the present study were to investigate the effect of PEP-19 overexpression on cell death triggered by Ca2+ overload and how the polypeptide levels are affected by glutamate-induced excitotoxicity and cerebral ischemia. Expression of PEP-19 in HEK293T cells suppressed calmodulin-dependent signaling and protected against cell death elicited by Ca2+ ionophore. Likewise, primary cortical neurons overexpressing PEP-19 became resistant to glutamate-induced cell death. In immunoprecipitation assay, wild type PEP-19 associated with calmodulin, whereas mutated PEP-19, which contains mutations within the calmodulin binding site of PEP-19, failed to associate with calmodulin. We found that the mutation abrogates both the ability to suppress calmodulin-dependent signaling and to protect cells from death. Additionally, the endogenous PEP-19 levels in neurons were significantly reduced following glutamate exposure, this reduction precedes neuronal cell death and can be blocked by treatment with calpain inhibitors. These data suggest that PEP-19 is a substrate for calpain, and that the decreased PEP-19 levels result from its degradation by calpain. A similar reduction of PEP-19 also occurred in the hippocampus of gerbils subjected to transient global ischemia. In contrast to the reduction in PEP-19, no changes in calmodulin occurred following excitotoxicity, suggesting the loss of negative regulation of calmodulin by PEP-19. Taken together, these results provide evidence that PEP-19 overexpression enhances resistance to Ca2+-mediated cytotoxicity, which might be mediated through calmodulin inhibition, and also raises the possibility that PEP-19 degradation by calpain might produce an aberrant activation of calmodulin functions, which in turn causes neuronal cell death.

Effect of combined humanPTH(1-34) and calcitonin treatment in ovariectomized rats

We examined the combined effects of human parathyroid hormone 1-34 (hPTH) and elcatonin (ECT: a synthetic derivative of eel calcitonin) to prevent loss of bone mass, architecture and strength in ovariectomized (OVX) rats. Fifty-four female rats (aged 13 weeks) were assigned to one of nine groups: Sham (fake surgery performed), OVX, ECT (15 U/kg administered), PTH5, PTH10 and PTH20 (5, 10 or 20 microg/kg administered), and E+PTH5, E+PTH10 and E+PTH20 (15 U/kg of ECT and 5, 10 or 20 microg/kg of hPTH administered). The drug or vehicle was subcutaneously administered three times a week for 12 weeks. The femurs were removed at the completion of the experiment. The right distal femoral metaphysis was used for measuring bone mineral density (BMD), analyzing trabecular bone structure by micro-computed tomography (microCT), and conducting the bone strength test, and the left femur was used for histomorphometric analysis. Trabecular bone volume (BV/TV) and other bone mass parameters were greater in the ECT and PTH groups than in the OVX group. The number of nodes (N.Nd/TV) and trabecular number (Tb.N) were significantly greater in the ECT group, and trabecular thickness (Tb.Th) and trabecular bone pattern factor (TBPf) were significantly greater in the PTH group. These results indicate that these drugs preserve the bone architecture by different means. Analysis by means of microCT revealed that BV/TV, Tb.N, fractal D and N.Nd/TV were significantly greater in the E+PTH groups than in the PTH groups at each concentration. Trabecular separation (Tb.Sp) was significantly lower in the E+PTH5 and E+PTH10 groups than in the respective PTH5 and PTH10 groups. When the maximum load was applied in a compression test on the distal femur, the E+PTH groups had higher values than the PTH groups, however, the three point bending strength of the diaphysis of femur in the E+PTH10 and E+PTH20 groups tended to be low compared to those in the PTH10 and PTH20 groups. These results indicate that combination therapy using PTH and ECT preserves the trabecular microarchitecture better than single-drug therapy using ECT or PTH in OVX rats, however, it is necessary to optimize the calcitonin (CT) dosage and administration in order to achieve the optimal combined effect of PTH and CT.