Circadian Clock Genes Regulate Temperature-Dependent Diapause Induction in Silkworm Bombyx mori.

The bivoltine strain of the domestic silkworm, Bombyx mori, exhibits a facultative diapause phenotype that is determined by maternal environmental conditions during embryonic and larval development. Although a recent study implicated a circadian clock gene period (per) in circadian rhythms and photoperiod-induced diapause, the roles of other core feedback loop genes, including timeless (tim), Clock (Clk), cycle (cyc), and cryptochrome2 (cry2), have to be clarified yet. Therefore, the aim of this study was to elucidate the roles of circadian clock genes in temperature-dependent diapause induction. To achieve this, per, tim, Clk, cyc, and cry2 knockout (KO) mutants were generated, and the percentages of diapause and non-diapause eggs were determined. The results show that per, tim, Clk, cyc, and cry2 regulated temperature-induced diapause by acting upstream of cerebral γ-aminobutyric acid (GABA)ergic and diapause hormone signaling pathways. Moreover, the temporal expression of the clock genes in wild-type (wt) silkworms was significantly different from that of thermosensitive transient receptor potential ankyrin 1 (TRPA1) KO mutants during embryonic development. Overall, the findings of this study provide target genes for regulating temperature-dependent diapause induction in silkworms.

Perioperative Deep Vein Thrombosis and D-dimer Measurement in Patients with Brain Tumor.

We investigated the appropriate D-dimer cutoff value for each brain tumor type for acute or subacute deep vein thrombosis (DVT) following transcranial brain tumor surgery.In this single-center retrospective study, a cumulative total of 128 patients who underwent transcranial brain tumor surgery were enrolled and classified into the glioma group, the other intracranial malignant tumor group, and the intracranial benign tumor group. Venous ultrasonography was performed if the D-dimer plasma levels were positive (≥1 µg/mL) before surgery and on postoperative day (POD) 3 or 7.Of the 128 cases, DVT developed in 32 (25.0%). Among those, acute or subacute DVT was diagnosed in 22 cases on POD 3 and in 8 cases on POD 7. Compared with DVT-negative cases on POD 3, acute or subacute DVT-positive cases on POD 3 revealed a significant increase in the D-dimer level in all groups combined and in the benign tumor group but not in the glioma group. With regard to DVT on POD 3 in all groups, the receiver operating characteristic curve for the D-dimer level on POD 3 demonstrated a cutoff value of 3.3 µg/mL (sensitivity [0.636] and specificity [0.750]). However, if this cutoff value was used in practice, eight cases would be false-negative with a minimum D-dimer level of 1.5 µg/mL.The D-dimer cutoff value for acute or subacute DVT on POD 3 could be set to 3.3 µg/mL; however, the setting resulted in several false-negative cases. Practically, 1.5 µg/mL of the D-dimer cutoff value on POD 3 might be appropriate to avoid false-negative results.

"Pigtail through snare" technique: an easy and fast way to retrieve a catheter fragment with inaccessible ends.

BACKGROUND: A catheter fragment with inaccessible ends can be retrieved using the well-known two-step method: making a free end with a pigtail catheter and seizing it with a snare catheter. Here we propose an easier and faster modification, named the "pigtail through snare" technique. CASE PRESENTATION: A 61-year-old female patient underwent removal of a central venous catheter fragment migrating to the right atrium. Both ends located in the right atrial appendage and left hepatic vein were inaccessible. Initially, a snare loop was opened in the inferior vena cava and a pigtail catheter was advanced through the snare loop to hook the catheter fragment. The free end was created by pulling the pigtail catheter, dragged automatically into the snare loop, grasped, and retrieved immediately. CONCLUSIONS: By passing the pigtail catheter through the snare loop in advance, the snaring maneuver becomes easy and fast in retrieving the catheter fragment with inaccessible ends.

Antagonists to endothelin receptor type B promote apoptosis in human pulmonary arterial smooth muscle cells.

AIMS: Vascular remodeling results from aberrations in the balance between cell proliferation and death, which is seen in the obstructive vasculature of pulmonary arterial hypertension (PAH). Endothelin (ET)-1 has a potent proliferative activity on vascular smooth muscle cells, and ET receptor inhibitors are used to treat PAH; however, it remains unclear whether ET receptor inhibition contributes to the apoptosis of pulmonary arterial smooth muscle cells (PASMCs), another cause of pulmonary vascular remodeling. MAIN METHODS: Cultured human PASMCs were treated with the ETA receptor antagonist BQ-123 (100µM), or the ETB antagonist A-192621 (1-100µM) or BQ-788 (1-100µM) for 48h. The cells were then incubated for another 24h with or without doxorubicin (DOX, 1µM), an anthracyclin antitumor antibiotic that promotes p53-mediated apoptosis. Cell viability and apoptosis were evaluated by MTT assays, caspase-3/7 activity assays, and Western blots for cleaved caspase-3 expression. KEY FINDINGS: The viability of PASMCs was significantly decreased by A-192621 and BQ-788, in a dose-dependent manner. A-192621 and BQ-788 significantly increased the caspase-3/7 activity and cleaved caspase-3 expression in PASMCs. The PASMCs' susceptibility to DOX-induced apoptosis was significantly higher in the presence of A-192621 and BQ-788 than with vehicle. However, BQ-123 did not affect these parameters. SIGNIFICANCE: Blockade of the ETB receptor increases the extent of apoptosis and susceptibility to DOX-induced apoptosis in PASMCs. Apoptosis caused by ETB receptor blockade in PASMCs may be one of the mechanisms by which vascular remodeling is reduced in ET receptor inhibitor-based PAH treatments.

The successful management of respiratory complications with long-term, low-dose macrolide administration in pediatric heart transplant recipients.

We report three pediatric heart transplant (HTx) patients whose respiratory symptoms were successfully controlled with long-term, low-dose macrolide administration (clarithromycin: CAM; approximately 2.5 mg/kg bid). The first case was an 18-year-old boy who underwent HTx at the age of three for dilated cardiomyopathy (DCM). Beginning at age 5, he had repeated fevers and respiratory symptoms. He was diagnosed with chronic sinusitis at age 11 and sinobronchial syndrome with mild bronchiectasis at age 14. Administration of long-term, low-dose CAM and otolaryngeal topical therapy led to significant improvement of his symptoms. The second case was a 7-year-old boy who underwent HTx for DCM at age one. Starting at age 4, he had repeated fevers and cough due to atelectasis and pneumonia. As antibiotics and respiratory physical therapy proved ineffective, he received long-term, low-dose CAM, resulting in successful control of his atelectasis and recurrent pneumonia. The third case was a 13-year-old boy who underwent HTx at age 6 for DCM. He had chronic sinusitis starting at age 7, and was diagnosed with obstructive sleep apnea syndrome at age 10. Adenotonsillectomy and continuous positive airway pressure support therapy were indicated. At age 13, long-term, lowdose CAM administration was started following mycoplasma infection. In all three cases, the levels of calcineurin inhibitors (cyclosporine and tacrolimus) and everolimus were kept in the optimal range with careful drug monitoring. Longterm, low-dose macrolide administration effectively prevents and treats respiratory complications in pediatric HTx patients as long as attention is paid to potential drug interactions.

Effects of selective endothelin (ET)-A receptor antagonist versus dual ET-A/B receptor antagonist on hearts of streptozotocin-treated diabetic rats.

AIMS: The aim was to study the differences in the effectiveness of two types of endothelin (ET) receptor antagonists (selective ET-A or dual ET-A/B antagonists) on the hearts of streptozotocin (STZ)-induced diabetic rats (type I diabetes) at functional and biochemical/molecular levels. MAIN METHODS: Citrate saline (vehicle) or STZ was injected into rats. The ET-A/B dual receptor antagonist (SB209670, 1mg/kg/day) and the ET-A receptor antagonist (TA-0201, 1mg/kg/day) were then administered to these rats. One week after injection, the animals were separated into those receiving SB209670, TA-0201 or vehicle by 4-week osmotic mini-pump. KEY FINDINGS: The VEGF level and percent fractional shortening in the diabetic heart were significantly decreased compared to the non-diabetic heart, whereas SB209670 and TA-0201 treatments greatly and comparably prevented this decrease. SB209670 treatment was more effective in reversing decreased expressions of KDR and phosphorylated AKT, downstream of VEGF angiogenic signaling, than TA-0201 treatment. The eNOS levels in hearts were significantly higher in diabetic rats than in healthy rats, and this increase was significantly reduced by TA-0210 but not by SB209670 treatment. SIGNIFICANCE: Improvement of KDR mRNA and pAKT levels by SB209670 but not TA-0201 suggests that dual ET-A/-B blockade may be effective in improving intracellular systems of these components in the diabetic rat heart. However, the present study also showed that TA-0201 or SB209670 improved percent fractional shortening and VEGF levels of the diabetic hearts to a similar extent, suggesting that ET-A blockade and dual ET-A/-B blockade are similarly effective in improving cardiac dysfunction in the diabetic rats.

Calcitonin gene-related peptide protects the myocardium from ischemia induced by endothelin-1: intravital microscopic observation and (31)P-MR spectroscopic studies.

AIMS: Calcitonin gene-related peptide (CGRP) is a potent vasodilator neuropeptide. We investigated the ameliorating effect of CGRP in myocardial ischemia induced by endothelin-1 (ET-1), with special emphasis on myocardial microvascular hemodynamics and levels of energy-related metabolites. MAIN METHODS: The Langendorff preparations of rat isolated heart were perfused at a constant flow rate. Microvascular blood flow was also visualized in the anterior epicardium of the left ventricle by means of an intravital fluorescence microscope system. Energy-related metabolite contents in the myocardium were measured by means of (31)P-magnetic resonance spectroscopy ((31)P-MRS). KEY FINDINGS: Intracoronary bolus injections of CGRP caused dose-dependent decreases in coronary perfusion pressure (CPP) in the hearts exposed to ET-1 (30 pmol). The vasodilator potency of CGRP was about 10,000-fold greater than that of nitroglycerin and 1,000-fold greater than that of isobutylmethylxanthine. Vasodilation of the small-sized arterioles (10-40 µm in diameter) in response to CGRP (100 pmol) was confirmed by direct microscopic observation. After ET-1 (30 pmol) plus vehicle administration, high energy phosphates (phosphocreatine (PCr), ATP) were markedly reduced (p<0.05). CGRP administration significantly (p<0.05) attenuated the anaerobic changes in the myocardium (decrease in PCr) and macrohemodynamic alterations (increase in CPP, decrease in dP/dt etc.) induced by ET-1. SIGNIFICANCE: We conclude that CGRP effectively confers hemodynamic and metabolic protections to isolated beating hearts against ET-1-induced myocardial ischemia.

Involvement of peptidyl-prolyl isomerase Pin1 in the inhibitory effect of fluvastatin on endothelin-1-induced cardiomyocyte hypertrophy.

AIMS: Cardiac hypertrophy is elicited by endothelin (ET)-1 as well as other neurohumoral factors, hemodynamic overload, and oxidative stress; HMG-CoA reductase inhibitors (statins) were shown to inhibit cardiac hypertrophy partly via the anti-oxidative stress. One of their common intracellular pathways is the phosphorylation cascade of MEK signaling. Pin1 specifically isomerizes the phosphorylated protein with Ser/Thr-Pro bonds and regulates their activity through conformational changes. There is no report whether the Pin1 activation contributes to ET-1-induced cardiomyocyte hypertrophy and whether the Pin1 inactivation contributes to the inhibitory effect of statins. The aim of this study was to reveal these questions. MAIN METHODS: We assessed neonatal rat cardiomyocyte hypertrophy using ET-1 and fluvastatin by the cell surface area, ANP mRNA expression, JNK and c-Jun phosphorylation, and [(3)H]-leucine incorporation. KEY FINDINGS: Fluvastatin inhibited ET-1-induced increase in the cell surface area, ANP expression, and [(3)H]-leucine incorporation; and it suppressed the signaling cascade from JNK to c-Jun. The phosphorylated Pin1 level, an inactive form, was decreased by ET-1; however, it reached basal level by fluvastatin. Furthermore, Pin1 overexpression clearly elicited cardiomyocyte hypertrophy, which was inhibited by fluvastatin. SIGNIFICANCE: This is the first report that ET-1-induced cardiomyocyte hypertrophy is mediated through the Pin1 activation and that the inhibitory effect of fluvastatin on cardiomyocyte hypertrophy would partly be attributed to the suppression of the Pin1 function. This study firstly suggests that Pin1 determines the size of hypertrophied cardiomyocyte by regulating the activity of phosphorylated molecules and that statins exert their pleiotropic effects partly via Pin1 inactivation.

Endothelin-1-induced cardiomyocyte hypertrophy is partly regulated by transcription factor II-F interacting C-terminal domain phosphatase of RNA polymerase II.

AIMS: Cardiac hypertrophy is associated with the increase of total amount of RNA, which is in accordance with RNA polymerase II (RNAPII) activation via C-terminal domain (CTD) phosphorylation of the largest subunit of RNAPII. It has been demonstrated that endothelin-1 (ET-1) phosphorylates CTD at the hypertrophic response in cardiomyocytes. However, it is unclear whether ET-1-induced hypertrophy is affected by the CTD phosphatase, transcription factor IIF-interacting CTD phosphatase1 (FCP1). MAIN METHODS: We analyzed whether ET-1-induced cardiomyocyte hypertrophy was affected by overexpression of FCP1 or dominant-negative form of FCP1 (dnFCP1) in neonatal rat cardiomyocytes. KEY FINDINGS: The level of ET-1-induced RNAPII CTD phosphorylation was decreased by FCP1 overexpression, whereas it was sustained by dnFCP1. Global RNA synthesis evaluated by [(3)H]-uridine incorporation showed that the ET-1-induced increase in RNA synthesis was suppressed by FCP1 and was augmented by dnFCP1. ET-1-induced increase in cell surface area was suppressed by FCP1 and was preserved by dnFCP1. Furthermore, the ET-1-induced increase in molecular markers of cardiac hypertrophy, expression of ANP and ß-MHC gene, was suppressed by FCP1 and was not inhibited by dnFCP1. SIGNIFICANCE: ET-1-induced cardiac hypertrophy and CTD phosphorylation level are functionally regulated by FCP1. These findings suggest that FCP1 plays an important role in ET-1-induced cardiac hypertrophy via controlling phosphorylation level of the RNAPII CTD.

Effects of long-acting beraprost sodium (TRK-100STP) in Japanese patients with pulmonary arterial hypertension.

The long-acting beraprost preparation TRK-100STP is formulated to provide sustained release of an orally active prostacyclin derivative to maintain the optimal plasma concentration for a longer period of time compared with the currently used conventional beraprost sodium. In the present study, we evaluated the efficacy of this newly developed formulation for pulmonary arterial hypertension (PAH).An open-label, 12-week multicenter clinical trial was performed in 46 patients with PAH. They were initially treated with 120 microg of TRK-100STP divided into 60 microg twice daily, followed by a stepwise increase to 360 microg given as 180 microg twice daily. The 6-minute walking distance showed a significant increase by 33.4+/-66.0 m (95% confidence interval [CI], 13.4 to 53.5) from the baseline measurement. Mean pulmonary artery pressure, total pulmonary vascular resistance, and pulmonary vascular resistance decreased by -2.8+/-5.5 mmHg (95% CI, -4.6 to -1.0), by -0.92+/-2.63 mmHg*L(-1)*min (95% CI, -1.78 to -0.05), and by -0.89+/-2.81 mmHg*L(-1)*min (95% CI, -1.84 to 0.06), respectively, from the baseline measurements. A higher efficacy was observed in patients with a maximum tolerated dose of 360 microg daily than those of 240 microg daily or less.Treatment with TRK-100STP for a 12-week period improved the exercise capacity, mean pulmonary artery pressure, and total pulmonary vascular resistance. TRK-100STP was effective for Japanese patients with PAH.

Phosphodiesterase type 4 inhibitor rolipram inhibits activation of monocytes during extracorporeal circulation.

OBJECTIVE: Cardiopulmonary bypass is associated with systemic inflammatory response syndrome and risk of multiorgan injury mediated by activated leukocytes. Phosphodiesterase type 4 is the predominant phosphodiesterase isozyme in leukocytes and plays a key role in the regulation of leukocyte activation. The aim of this study was to examine the effect of rolipram, a selective phosphodiesterase type 4 inhibitor, on functional changes of monocytes during simulated extracorporeal circulation. METHODS AND RESULTS: Simulated extracorporeal circulation was established by recirculating heparinized human blood for 120 minutes on a membrane oxygenator with or without 10 micromol/L of rolipram. L-selectin and CD11b expression of monocytes were measured with flow cytometry. C4d fragment, Bb fragment, C5b-9, and interleukin-6 were measured with enzyme immunoassay. Rolipram reduced the increase in CD11b expression and the decrease in L-selectin expression of monocytes in response to simulated extracorporeal circulation. Rolipram inhibited the increase in C4d fragment and interleukin-6, but it did not affect the increase in Bb fragment or C5b-9. CONCLUSION: Rolipram inhibited changes in adhesion molecule expression and interleukin-6 release by activated monocytes in simulated extracorporeal circulation. This study suggests that phosphodiesterase type 4 inhibition could be feasible therapeutic strategy to prevent exaggerated inflammatory response and organ injury in patients undergoing cardiopulmonary bypass.

Sivelestat reduces inflammatory mediators and preserves neutrophil deformability during simulated extracorporeal circulation.

BACKGROUND: Neutrophil is a major focus in efforts to ameliorate the systemic inflammatory response associated with cardiopulmonary bypass. Neutrophil elastase is a powerful proteolytic enzyme, and plays a pivotal role in the development of the inflammatory response. This study assesses the inhibitory effects of sivelestat, a highly specific neutrophil elastase inhibitor, on elastase levels, cytokine production, and the functional changes of neutrophils in a simulated extracorporeal circulation model. METHODS: Simulated recirculation was established by recirculating heparinized (3.75 U/mL) human blood for 120 minutes in an oxygenator and a roller pump circuit with and without 100 micromol/L of sivelestat (n = 7 for each group). Neutrophil elastase and interleukin-8 were measured with an enzyme immunoassay. Neutrophil deformability was evaluated by simulated microcapillaries. The neutrophil F-actin and the expression of CD11b and L-selectin were measured by flow cytometry. RESULTS: Sivelestat reduced both neutrophil elastase levels (p = 0.0006) and interleukin-8 production (p < 0.0001) at 120 minutes of recirculation. Sivelestat also significantly preserved neutrophil deformability (p = 0.017) and reduced F-actin expression (p = 0.0037). The drug did not modulate the changes of CD11b or L-selectin. CONCLUSIONS: This study suggests that specific elastase inhibition with sivelestat could be a feasible therapeutic strategy for patients undergoing cardiopulmonary bypass to attenuate neutrophil-derived inflammatory response and organ injuries.

Nafamostat preserves neutrophil deformability and reduces microaggregate formation during simulated extracorporeal circulation.

BACKGROUND: Initial sequestration of activated neutrophils and platelet microaggregates in capillaries are responsible for the inflammatory response associated with cardiopulmonary bypass. The study assesses the inhibitory effects of nafamostat mesilate on neutrophil and platelet activation, and on the neutrophil deformability change and microaggregate formation during simulated extracorporeal circulation. METHODS: Fresh heparinized human blood was recirculated for 120 minutes in a membrane oxygenator and a roller pump with and without nafamostat (1.0 mg bolus plus 8.0 mg/h infusion; n = 10 for each group). Neutrophil and platelet counts and platelet aggregation were measured. CD11b, L-selectin, and cytoplasmic F-actin of neutrophils were measured by flow cytometry. The microchannel transit time of whole blood was measured as a marker of neutrophil deformability and microaggregate formation. Neutrophil elastase and complement C4d were measured using enzyme immunoassay. RESULTS: Nafamostat preserved platelet counts and inhibited platelet aggregation. Nafamostat significantly reduced neutrophil elastase release at 120 minutes of recirculation, and F-actin expression at 30 and 60 minutes. The drug did not modulate the changes of CD11b, L-selectin, or C4d. Whole blood filterability was significantly preserved by nafamostat at 30 and 120 minutes. CONCLUSIONS: Nafamostat preserves blood filterability during recirculation, possibly by suppression of F-actin expression and platelet activation. Nafamostat may reduce neutrophil sequestration and microaggregate formation in the microcirculation during cardiopulmonary bypass.

ONO-6818, a novel, potent neutrophil elastase inhibitor, reduces inflammatory mediators during simulated extracorporeal circulation.

BACKGROUND: Among the serine proteases, neutrophil elastase is a powerful cytotoxic enzyme and plays a pivotal role in the inflammatory response associated with cardiopulmonary bypass. This study assesses the effects of the specific inhibition of neutrophil elastase by a novel, potent, low-molecular-weight neutrophil elastase inhibitor, ONO-6818. We hypothesized that ONO-6818 reduces inflammatory mediators and modulates adhesion molecules and the deformability of neutrophils during simulated extracorporeal circulation. METHODS: Simulated extracorporeal circulation was established by recirculating fresh heparinized (3.75 U/mL) human blood for 120 minutes in a membrane oxygenator and a roller pump with and without 1.0 micromol/L of ONO-6818 (n = 9 for control group, n = 7 for ONO-6818 group). The neutrophil adhesion molecules, CD11b and L-selectin, and the cytoplasmic F-actin of neutrophils were measured by flow cytometry. Neutrophil deformability was evaluated using simulated silicon microcapillaries. Neutrophil elastase, interleukin 8, and C5b-9 were measured using enzyme immunoassay. RESULTS: Neutrophil elastase levels were significantly lower in the ONO-6818 group. ONO-6818 significantly reduced interleukin 8 and C5b-9 production. ONO-6818 did not modulate changes of CD11b and L-selectin during recirculation. Cytoplasmic F-actin content and changes of neutrophil deformability did not significantly differ between the groups. CONCLUSIONS: Inhibition of neutrophil elastase activity with ONO-6818 reduces further interleukin 8 production and the formation of the complement membrane attack complex, and this results in a reduction of neutrophil elastase levels during simulated extracorporeal circulation. This study suggests that specific neutrophil elastase inhibition with ONO-6818 is a feasible therapeutic option to attenuate the exaggerated inflammatory response associated with cardiopulmonary bypass.

Activated neutrophils and platelet microaggregates impede blood filterability through microchannels during simulated extracorporeal circulation.

BACKGROUND: Neutrophil sequestration and platelet microaggregates in organ capillaries have been implicated in the inflammatory response associated with cardiopulmonary bypass. We examined the filterability of neutrophils and platelet microaggregates through silicon microchannels during simulated extracorporeal circulation. We hypothesize that blood contact with artificial surfaces over time decreases the ability of neutrophils, platelets, and their aggregates to pass through microchannels. METHODS: Fresh human blood from donors (n = 9) was recirculated for 120 minutes in a simulated extracorporeal circuit. Blood samples were obtained from a donor at 0, 30, 60, and 120 minutes of recirculation. The microchannel transit time and the flow behavior of blood cells were evaluated by a silicon microchannel array flow analyzer. CD11b, L-selectin, and F-actin of neutrophils were measured by flow cytometry. Neutrophil and platelet counts and platelet aggregation to adenosine diphosphate were measured. RESULTS: The microchannel transit time was prolonged during recirculation, reaching 185.9% +/- 25.6% of baseline at 120 minutes. The video microscope showed that neutrophils and platelet microaggregates plugged the microchannels. CD11b, L-selectin, and F-actin levels changed significantly by 120 minutes. Platelet counts decreased and platelet aggregability was attenuated. CONCLUSIONS: Simulated extracorporeal circulation caused a progressive loss in the ability of neutrophils, platelets, and their aggregates to pass through the microchannels independent of neutrophil adhesion molecule expression.

Phosphodiesterase type 4 inhibition of activated polymorphonuclear leukocytes in a simulated extracorporeal circulation model.

OBJECTIVES: Cardiopulmonary bypass is associated with a systemic inflammatory response syndrome and the risk of multiorgan injuries mediated by activated polymorphonuclear leukocytes. Phosphodiesterase type 4 is the predominant phosphodiesterase isozyme in polymorphonuclear leukocytes and plays a key role in the regulation of polymorphonuclear leukocyte activation. The aim of this study was to examine the effect of rolipram, a selective phosphodiesterase type 4 inhibitor, on the functional changes of polymorphonuclear leukocytes by using simulated extracorporeal circulation. METHODS: Simulated extracorporeal circulation was established by recirculating heparinized human blood for 120 minutes on a membrane oxygenator with and without 10 micro mol/L rolipram. F-actin content and L-selectin and CD11b expression of polymorphonuclear leukocytes were measured by means of flow cytometry. Polymorphonuclear leukocyte deformability was evaluated with a microchannel array flow analyzer that had a similar diameter as the capillaries. Polymorphonuclear leukocyte elastase was measured with an enzyme immunoassay. RESULTS: Rolipram reduced the increase of F-actin content of polymorphonuclear leukocytes and the increase of transit time of 100 micro L of blood sample through a microchannel. Rolipram reduced the increase of CD11b expression and the decrease of L-selectin expression of polymorphonuclear leukocytes. Rolipram reduced the release of elastase from polymorphonuclear leukocytes. CONCLUSION: Rolipram inhibited the deformability change mediated by F-actin assembly, the changes in adhesion molecules, and the release of elastase from activated polymorphonuclear leukocytes in simulated extracorporeal circulation. This study suggests that phosphodiesterase type 4 inhibition could be a feasible therapeutic strategy to prevent the exaggerated inflammatory response related to cardiopulmonary bypass.