Non-linear analysis of stabilograms with alcoholic intake

Equilibrium function in the cerebellum (vestibulo-cerebellar system) can deteriorate under the influence of alcohol. In the Romberg posture, the center of gravity, which was measured every 50 ms by stabilometry, appeared to shift with alcohol ingestion. In the previous study, a locus in the center of gravity (stabilogram) was converted to values of statistical indices such as area of sway, total locus length, and locus length per unit area, although these indices could not always distinguish between the statokinesigrams sampled from seven healthy young males in sober and intoxicated states. This measurement was made with an AMTI force plate. In this study, "translation error" was estimated in a d-dimensional embedding space in order to compare statokinesigrams recorded before and after the ingestion of doubly diluted brandy in 30 s (1 ≤ d ≤ 10). We succeeded in validating a stochastic differential equation as a mathematical model of the body sway. The randomness in the model was preserved after alcohol intake and significantly increased in the medial/lateral direction. Visual information referred by the postural control system when standing might be interfered by the effects of intoxication, which was regarded as disturbance. This method is considered to be useful to diagnose the disorders of the vestibulocerebellar system.

Lysophosphatidic acid stimulates epidermal growth factor-family ectodomain shedding and paracrine signaling from human lung fibroblasts

Lysophospatidic acid (LPA) is a bioactive lipid mediator implicated in tissue repair and wound healing. It mediates diverse functional effects in fibroblasts, including proliferation, migration and contraction, but less is known about its ability to evoke paracrine signaling to other cell types involved in wound healing. We hypothesized that human pulmonary fibroblasts stimulated by LPA would exhibit ectodomain shedding of epidermal growth factor receptor (EGFR) ligands that signal to lung epithelial cells. To test this hypothesis, we used alkaline phosphatase-tagged EGFR ligand plasmids transfected into lung fibroblasts, and enzyme-linked immunosorbent assays to detect shedding of native ligands. LPA induced shedding of alkaline phosphatase-tagged heparin-binding epidermal growth factor (HB-EGF), amphiregulin, and transforming growth factor-a; non-transfected fibroblasts shed amphiregulin and HBEGF under baseline conditions, and increased shedding of HB-EGF in response to LPA. Treatment of fibroblasts with LPA resulted in elevated phosphorylation of extracellular signal-regulated kinase 1/2, enhanced expression of mRNA for c-fos, HB-EGF and amphiregulin, and enhanced proliferation at 96 hours. However, none of these fibroblast responses to LPA required ectodomain shedding or EGFR activity. To test the ability of LPA to stimulate paracrine signaling from fibroblasts, we transferred conditioned medium from LPA-stimulated cells, and found enhanced EGFR and extracellular signal-regulated kinase 1/2 phosphorylation in reporter A549 cells in excess of what could be accounted for by transferred LPA alone. These data show that LPA mediates EGF-family ectodomain shedding, resulting in enhanced paracrine signaling from lung fibroblasts to epithelial cells.

Induction of mucin and MUC5AC expression by the protease activity of Aspergillus fumigatus in airway epithelial cells

Allergic bronchopulmonary mycosis, characterized by excessive mucus secretion, airflow limitation, bronchiectasis, and peripheral blood eosinophilia, is predominantly caused by a fungal pathogen, Aspergillus fumigatus. Using DNA microarray analysis of NCI-H292 cells, a human bronchial epithelial cell line, stimulated with fungal extracts from A. fumigatus, Alternaria alternata, or Penicillium notatum, we identified a mucin-related MUC5AC as one of the genes, the expression of which was selectively induced by A. fumigatus. Quantitative RT-PCR, ELISA, and histochemical analyses confirmed an induction of mucin and MUC5AC expression by A. fumigatus extracts or the culture supernatant of live microorganisms in NCI-H292 cells and primary cultures of airway epithelial cells. The expression of MUC5AC induced by A. fumigatus extracts diminished in the presence of neutralizing Abs or of inhibitors of the epidermal growth factor receptor or its ligand, TGF-α. We also found that A. fumigatus extracts activated the TNF-α-converting enzyme (TACE), critical for the cleavage of membrane-bound pro-TGF-α, and its inhibition with low-molecular weight inhibitors or small interfering RNA suppressed the expression of MUC5AC. The protease activity of A. fumigatus extracts was greater than that of other fungal extracts, and treatment with a serine protease inhibitor, but not with a cysteine protease inhibitor, eliminated its ability to activate TACE or induce the expression of MUC5AC mRNA in NCI-H292. In conclusion, the prominent serine protease activity of A. fumigatus, which caused the overproduction of mucus by the bronchial epithelium via the activation of the TACE/TGF-α/epidermal growth factor receptor pathway, may be a pathogenetic mechanism of allergic bronchopulmonary mycosis.

Role of prostaglandin D2 receptor CRTH2 in sustained eosinophil accumulation in the airways of mice with chronic asthma

The prostaglandin D(2) (PGD(2))/CRTH2 pathway is important for eosinophil trafficking in vitro; however, genetic deficiency of CRTH2 does not suppress in vivo eosinophilic airway inflammation in acute models of asthma, and the role of CRTH2 in the pathogenesis of asthma is still ambiguous. Therefore, in the present study we explored whether the PGD(2)/CRTH2 pathway could affect the phenotypes of chronic asthma. Either CRTH2-deficient (CRTH2-/-) or wild-type mice were sensitized and exposed to ovalbumin (OVA) for 3 days (acute model) or 6 weeks (chronic model). While the magnitude of the acute eosinophilic inflammation was equivalent between CRTH2-/- and wild-type mice, the number of inflammatory cells and eosinophils in bronchoalveolar lavage fluid after chronic OVA exposure was significantly reduced in CRTH2-/- mice (18.0 ± 2.6 × 10(4) cells and 2.0 ± 0.5 × 10(4) cells) compared to wild-type mice (27.9 ± 2.5 × 10(4) cells and 6.8 ± 1.1 × 10(4) cells, p < 0.001). On the contrary, no difference was observed between CRTH2-/- and wild-type mice in terms of airway hyperresponsiveness or remodeling (goblet cell hyperplasia) in the chronic model of asthma. In conclusion, CRTH2 that mediates PGD(2) activity is essential for sustained eosinophilic inflammation in the airways, and its antagonists could exert an anti-inflammatory effect in chronic asthma.

TNF-α-converting enzyme/a disintegrin and metalloprotease-17 mediates mechanotransduction in murine tracheal epithelial cells

Bronchoconstriction applies compressive stress to airway epithelial cells. We show that the application of compressive stress to cultured murine tracheal epithelial cells elicits the increased phosphorylation of extracellular signal-regulated kinase (ERK) and Akt through an epidermal growth factor receptor (EGFR)-dependent process, consistent with previous observations of the bronchoconstriction-induced activation of EGFR in both human and murine airways. Mechanotransduction requires metalloprotease activity, indicating a pivotal role for proteolytic EGF-family ligand shedding. However, cells derived from mice with targeted deletions of the EGFR ligands Tgfα and Hb-egf showed only modest decreases in responses, even when combined with neutralizing antibodies to the EGFR ligands epiregulin and amphiregulin, suggesting redundant or compensatory roles for individual EGF family members in mechanotransduction. In contrast, cells harvested from mice with a conditional deletion of the gene encoding the TNF-α-converting enzyme (TACE/ADAM17), a sheddase for multiple EGF-family proligands, displayed a near-complete attenuation of ERK and Akt phosphorylation responses and compressive stress-induced gene regulation. Our data provide strong evidence that TACE plays a critical central role in the transduction of compressive stress.

Loading and knee alignment have significant influence on cartilage MRI T2 in porcine knee joints

OBJECTIVE

Physiological magnetic resonance imaging (MRI) under loading or knee malalignment conditions has not been thoroughly investigated. We assessed the influence of static loading and knee alignment on T2 (transverse relaxation time) mapping of the knee femoral cartilage of porcine knee joints using a non-metallic pressure device.

METHODS

Ten porcine knee joints were harvested en bloc with intact capsules and surrounding muscles and imaged using a custom-made pressure device and 3.0-T MRI system. Sagittal T2 maps were obtained (1) at knee neutral alignment without external loading (no loading), (2) under mechanical compression of 140 N (neutral loading), and (3) under the same loading conditions as in (2) with the knee at 10 degrees varus alignment (varus loading). T2 values of deep, intermediate, and superficial zones of the medial and lateral femoral cartilages at the weight-bearing area were compared among these conditions using custom-made software. Cartilage contact pressure between the femoral and tibial cartilages, measured by a pressure-sensitive film, was correlated with cartilage T2 measurements.

RESULTS

In the medial cartilage, mean T2 values of the deep, intermediate, and superficial zones decreased by 1.4%, 13.0%, and 6.0% under neutral loading. They further decreased by 4.3%, 19.3%, and 17.2% under varus loading compared to no loading. In the lateral cartilage, these mean T2 values decreased by 3.9%, 7.7%, and 4.2% under neutral loading, but increased by 1.6%, 9.6%, and 7.2% under varus loading. There was a significant decrease in T2 values in the intermediate zone of the medial cartilage under both neutral and varus loading, and in the superficial zone of the medial cartilage under varus loading (P<0.05). Total contact pressure values under neutral loading and varus loading conditions significantly correlated with T2 values in the superficial and intermediate zones of the medial cartilages.

CONCLUSIONS

The response of T2 to change in static loading or alignment varied between the medial and lateral cartilages, and among the deep, intermediate, and superficial zones. These T2 changes were significantly related to the contact pressure measurements. Our results indicate that T2 mapping under loading allows non-invasive, biomechanical assessment of site-specific stress distribution in the cartilage.

Impact of pharmacokinetics and pharmacogenetics on the efficacy of pranlukast in Japanese asthmatics

BACKGROUND AND OBJECTIVE

Wide inter-individual variability in therapeutic effects limits the efficacy of leukotriene (LT) receptor antagonists in the treatment of asthma. We have reported that genetic variability in the expression of LTC(4) synthase is associated with responsiveness to pranlukast in Japanese asthmatic patients. However, the effects of pharmacokinetic variability are less well known. This was an analysis of the pharmacokinetics of pranlukast in a population of adult asthmatics, and its effect on clinical responses. Other factors that may be related to the therapeutic effects of pranlukast, including LTC(4) synthase gene polymorphisms, were also investigated.

METHODS

The population pharmacokinetics of pranlukast was analysed in a one-compartment model, using data collected in 50 Japanese adults with moderate to severe asthma, who were treated with pranlukast, 225 mg bd for 4 days. In 32 of these patients, in whom the clinical response to pranlukast (increase in FEV(1) after 4 weeks of treatment) was measured in a previous study, a combined pharmacokinetic and pharmacogenetic analysis was performed.

RESULTS

Using the population pharmacokinetic model, the estimated the mean oral clearance (CL/F) of pranlukast was 16.4 L/h, and the inter-individual variability was 30.1%. Univariate and multivariate analyses showed that LTC(4) synthase polymorphisms, but not the CL/F of the drug, predicted an improvement in pulmonary function with pranlukast treatment (P < 0.05).

CONCLUSIONS

There was marked inter-individual variability in the pharmacokinetics of pranlukast among adult asthmatics, but this had little impact on the clinical effectiveness of the drug.

TP receptor-mediated release of eosinophil chemotactic activity from human bronchial smooth muscle cells

There are reports indicating that thromboxane A(2) receptors (TP receptors) may stimulate the eosinophil accumulation in the lower airways of asthmatics, however, the mechanisms behind such an effect remain unknown. We quantified the synthesis of eosinophil chemotactic activity and eosinophilic CC chemokines, including CCL5, CCL7, CCL8, CCL11, CCL13, CCL24, and CCL26 in primary cultures of human bronchial smooth muscle cells (BSMC) stimulated with a prostanoid TP receptor agonist, IBOP (10(-9)-10(-7) M). The activation of prostanoid TP receptors in BSMC induced the release of potent eosinophil chemoattractant(s) in the presence of interleukin (IL)-4. CCL11/eotaxin-1 was the only synthesis significantly increased by IBOP co-stimulated with IL-4, and pretreatment with an anti-CCL11 antibody abrogated the eosinophil chemotactic activity released from IBOP/IL-4-stimulated BSMC. The effect of IBOP was also completely blocked by pretreatment with a prostanoid TP receptor-specific antagonist, AA-2414. IBOP had no effect on the expression of IL-4 receptor-alpha, or on the IL-4-induced phosphorylation of STAT6 in BSMC. In conclusion, activation of prostanoid TP receptors in a Th2-dominant microenvironment might exacerbate the eosinophilic inflammation of the airways by synthesis and release of CCL11 from BSMC.

[Prader-Willi syndrome associated with obesity hypoventilation syndrome]

Prader-Willi syndrome (PWS) is a genetic disorder, characterized by shorter height, severe obesity and muscular hypotonicity. In particular, sleep disordered breathing (SDB) is a well-known complication in PWS. We encountered one case of PWS, complicated by typical obesity hypoventilation syndrome. A 23-year-old woman had been given a diagnosis of PWS as age 1, therefore she was treated with growth hormone replacement therapy, and with uvulopalatopharyngoplasty (UPPP) for her narrow throat. Her weight increased greatly to 96kg, body mass index (BMI) 51 kg/m2, resulting in hypersomnolence, cyanosis, heavy snoring, and nocturnal awakening. Eventually, she was admitted because of urinary incontinuence and loss of consciousness. On admission, she had severe hypoxia plus substantial hypercapnia, and her chest X-ray film showed severe cardiomegaly with massive pleural and pericardial effusion. On polysomnography (PSG) one week later, her apnea hypopnea index (AHI) was 16 with a mean nocturnal arterial saturation of 74%, mean percutaneous PCO2 59 Torr, which rose to 73 Torr during REM sleep. Non-invasive positive pressure ventilation (NPPV) was initiated, and improved her condition greatly. She was discharged, but continued to recieve NPPV, and her condition has stayed improved.

[Overlap syndrome involving obstructive sleep apnea syndrome associated with chronic obstructive pulmonary disease]

We reported a case of overlap syndrome involving severe obstructive sleep apnea syndrome (OSAS) associated with chronic obstructive lung disease (COPD). This patient was a 52-year-old heavy smoking man, who had suffered from snoring and apnea for five years, and was admitted to our hospital because of worsening dyspnea. His BMI was 25 Kg/M2, His jaw was very small and he had a narrow upper airway. Chest X-ray showed hyperlucency throughout both lung fields with a markedly dilatation pulmonary arteries. His PaO2 was 62Torr, PaCO2 was 47Torr, FEV(1.0%) was 59%, mean pulmonary artery pressure was 27 mmHg, PSG showed that AHI was 70, were most pronounced during rapid eye movement sleep. He was given a diagnosis of overlap syndrome of OSAS associated with COPD. Generally, Overlap syndrome was believed that chronic bronchitis type (blue bloater) was more frequent than emphysema type. This case was a very rare case, with no obesity, moderate COPD, associated with pulmonary hypertension and hypercapnea, and then to be severe OSAS. However we should be more careful about the OSAS associated with overlap syndrome of the Japanese patients, because to be one factor of exacerbation of respiratory failure.

Cyclooxygenase-2/prostaglandin D2/CRTH2 pathway mediates double-stranded RNA-induced enhancement of allergic airway inflammation

Respiratory RNA viruses responsible for the common cold often worsen airway inflammation and bronchial responsiveness, two characteristic features of human asthma. We studied the effects of dsRNA, a nucleotide synthesized during viral replication, on airway inflammation and bronchial hyperresponsiveness in murine models of asthma. Intratracheal instillation of poly I:C, a synthetic dsRNA, increased the airway eosinophilia and enhanced bronchial hyperresponsiveness to methacholine in OVA-sensitized, exposed rats. These changes were associated with induction of cyclooxygenase-2 (COX-2) expression and COX-2-dependent PGD2 synthesis in the lungs, particularly in alveolar macrophages. The direct intratracheal instillation of PGD2 enhanced the eosinophilic inflammation in OVA-exposed animals, whereas pretreatment with a dual antagonist against the PGD2 receptor-(CRTH2) and the thromboxane A2 receptor, but not with a thromboxane A2 receptor-specific antagonist, nearly completely eliminated the dsRNA-induced worsening of airway inflammation and bronchial hyperresponsiveness. CRTH2-deficient mice had the same degree of allergen-induced airway eosinophilia as wild-type mice, but they did not exhibit a dsRNA-induced increase in eosinophil accumulation. Our data demonstrate that COX-2-dependent production of PGD2 followed by eosinophil recruitment into the airways via a CRTH2 receptor are the major pathogenetic factors responsible for the dsRNA-induced enhancement of airway inflammation and responsiveness.

Angiotensin II type 1 receptor blocker attenuates exacerbated left ventricular remodeling and failure in diabetes-associated myocardial infarction

Diabetes mellitus adversely affects the outcomes in patients with myocardial infarction (MI), due in part to the exacerbation of left ventricular (LV) remodeling. Although angiotensin II type 1 receptor blocker (ARB) has been demonstrated to be effective in the treatment of heart failure, information about the potential benefits of ARB on advanced LV failure associated with diabetes is lacking. To induce diabetes, male mice were injected intraperitoneally with streptozotocin (200 mg/kg). At 2 weeks, anterior MI was created by ligating the left coronary artery. These animals received treatment with olmesartan (0.1 mg/kg/day; n = 50) or vehicle (n = 51) for 4 weeks. Diabetes worsened the survival and exaggerated echocardiographic LV dilatation and dysfunction in MI. Treatment of diabetic MI mice with olmesartan significantly improved the survival rate (42% versus 27%, P < 0.05) without affecting blood glucose, arterial blood pressure, or infarct size. It also attenuated LV dysfunction in diabetic MI. Likewise, olmesartan attenuated myocyte hypertrophy, interstitial fibrosis, and the number of apoptotic cells in the noninfarcted LV from diabetic MI. Post-MI LV remodeling and failure in diabetes were ameliorated by ARB, providing further evidence that angiotensin II plays a pivotal role in the exacerbated heart failure after diabetic MI.

TLR3-mediated synthesis and release of eotaxin-1/CCL11 from human bronchial smooth muscle cells stimulated with double-stranded RNA

Respiratory infections with RNA viruses, such as rhinovirus or respiratory syncytial virus, are a major cause of asthma exacerbation, accompanied by enhanced neutrophilic and/or eosinophilic inflammation of the airways. We studied the effects of dsRNA synthesized during RNA virus replication, and of its receptor, TLR3, on the synthesis of eosinophilic chemokines in bronchial smooth muscle cells (BSMC). Synthetic dsRNA, polyinosinic-cystidic acid (poly(I:C)), induced the synthesis of eosinophilic chemokines, eotaxin-1/CCL11 and RANTES/CCL5, from primary cultures of human BSMC, and IL-4 increased synergistically the synthesis of poly(I:C)-induced CCL11. A robust eosinophil chemotactic activity was released from BSMC stimulated with poly(I:C) and IL-4, which was mostly inhibited by preincubation with an anti-CCL11, but not with an anti-CCL5 Ab. Although the immunoreactivity of TLR3 was detectable on the cellular surface of BSMC by flow cytometric analysis, pretreatment with an anti-TLR3-neutralizing Ab failed to block the poly(I:C)-induced synthesis of CCL11. We have determined by confocal laser-scanning microscopy that the immunoreactivity of TLR3 was aggregated intracellularly in poly(I:C)-stimulated BSMC, colocalizing with fluorescein-labeled poly(I:C). The synthesis of CCL11 was prominently inhibited by the transfection of TLR3-specific small interfering RNA or by bafilomycin A1, an endosomal acidification inhibitor, further supporting the essential role played by intracellular TLR3 in the synthesis of poly(I:C)-induced CCL11 in BSMC. In conclusion, these observations suggest that, by activating intracellular TLR3 in BSMC, respiratory RNA virus infections stimulate the production of CCL11 and enhance eosinophilic inflammation of the airways in the Th2-dominant microenvironment.

Prostaglandin D2-induced eosinophilic airway inflammation is mediated by CRTH2 receptor

Mast cell-derived prostaglandin D(2) (PGD(2)) is one of the essential modulators of eosinophilic airway inflammation in asthma and allergic rhinitis. Two G protein-coupled receptors for PGD(2), prostaglandin D(2) receptor (DP) and chemoattractant receptor-homologous molecule expressed on Th(2) cells (CRTH2), are both expressed on the surface of eosinophils, and CRTH2 has been demonstrated to mediate PGD(2)-induced eosinophil mobilization in vitro. However, it has not yet been determined whether PGD(2) and its receptors mediate in vivo eosinophil trafficking into the airways or other organs. We demonstrated that intratracheal administration of PGD(2) in rats pretreated with systemic interleukin-5 (IL-5) injection induced marked airway eosinophilia, determined by the differential counts of cells in bronchoalveolar lavage (BAL) fluid and lung histology, within 2 h. Systemic IL-5 alone significantly increased the number of eosinophils in the peripheral blood but showed no effect on airway eosinophilia. Three CRTH2-specific agonists (13,14-dihydro-15-keto-PGD(2), 11-deoxy-11-methylene-15-keto-PGD(2), and indomethacin) demonstrated equivalent induction of BAL eosinophilia to that of PGD(2), but a DP agonist (BW 245C [5-(6-carboxyhexyl)-1-(3-cyclohexyl-3-hydroxypropyl)-hydantoin]) or a thromboxane A(2) receptor (TP) agonist ([1S-1alpha,2beta(5Z), 3alpha(1E,3R*),4alpha)]-7-[3-(3-hydroxy-4-(4'-iodophenoxy)-1-butenyl)-7-oxabicyclo-[2.2.1]heptan-2-yl]-5-heptenoic acid) showed no effect. PGD(2) or CRTH2 agonist-induced BAL eosinophilia was almost completely inhibited by pretreatment with a CRTH2/TP antagonist, ramatroban [BAY-u3405; (+)-(3R)-3-(4-fluorobenzenesulfonamido)-1,2,3,4-tetra-hydrocarbazole-9-propionic acid], whereas a TP-specific antagonist, SQ29,548 (5-heptenoic, 7-[3-[[2-[(phenylamino)carbonyl]hydrazino]methyl]-7-oxabicyclo[2.2.1]-hept-2-yl]-[1S-[1alpha,2alpha(Z),3alpha,4alpha]]), or a DP-specific antagonist, BW A868C [3-benzyl-5-(6-carboxyhexyl)-1-(2-cyclohexy-2-hydroxyethylamino)-hydantoin], did not inhibit the effects of PGD(2). These results suggest that CRTH2 plays a significant role in the eosinophil trafficking from the bloodstream into the airways in PGD(2)-related airway inflammation.

Human bronchial smooth muscle cell proliferation via thromboxane A2 receptor

Thromboxane A2 receptor (TP) mediates bronchial smooth muscle cell (BSMC) contraction, airway hyperresponsiveness, and airway inflammation in patients with asthma. In the present study, a pathogenic role of TP activation in airway remodeling was examined using primary cultures of human BSMC. A TP agonist, I-BOP, concentration-dependently enhanced not only bromodeoxyuridine (BrdU) uptake but also cell proliferation of BSMC. A TP-selective antagonist, AA-2414, blocked the effects of I-BOP on both BrdU uptake and cell proliferation. I-BOP-induced BrdU uptake was significantly blocked by two non-selective tyrosine kinase inhibitors, genistein and herbimycin A, or a Src family tyrosine kinase inhibitor, PP2, but not by an inhibitor of epidermal growth factor (EGF) receptor-associated tyrosine kinase, AG1478. In conclusion, TP receptor activation causes DNA synthesis and cell proliferation of human BSMC by activating tyrosine kinases including Src, but not by EGF receptor transactivation.

Inhibition of TGF-? signaling exacerbates early cardiac dysfunction but prevents late remodeling after infarction

OBJECTIVE

Transforming growth factor (TGF)-beta promotes the deposition of extracellular matrix protein and also acts as an anti-inflammatory cytokine. These biological effects might be involved in the development and progression of left ventricular (LV) remodeling and failure after myocardial infarction (MI). However, its pathophysiological significance remains obscure in post-MI hearts.

METHODS

Anterior MI was produced in mice by ligating the left coronary artery. TGF-beta mRNA levels increased in both infarcted and noninfarcted LV after MI. To block TGF-beta signaling during the early phase of MI, an extracellular domain of TGF-beta type II receptor (TbetaIIR) plasmid was transfected into the limb skeletal muscles 7 days before ligation.

RESULTS

TbetaIIR increased the mortality during 24 h of MI, as well as exacerbated LV dilatation and contractile dysfunction, the infiltration of neutrophils, and gene expression of tumor necrosis factor-alpha, interleukin-1beta, and monocyte chemoattractant protein-1 compared with nontreated MI mice despite the comparable infarct size. Next, to block TGF-beta signaling during the later phase, TbetaIIR was transfected into mice at days 0 and 7 after ligation. At 4 weeks, LV dilatation and contractile dysfunction in association with myocyte hypertrophy and interstitial fibrosis of noninfarcted LV seen in MI mice were prevented by TbetaIIR.

CONCLUSIONS

The activation of TGF-beta is protective against ischemic myocardial damage during the early phase. However, the beneficial effects might be lost, when its expression is sustained, thereby leading to LV remodeling and failure after MI.

PAF responsiveness in Japanese subjects with plasma PAF acetylhydrolase deficiency

Approximately 4% of the Japanese population genetically lack plasma platelet activating factor acetylhydrolase (PAF-AH) and show a higher prevalence of thromboembolic disease, but whether they are susceptible to another PAF-related disease, asthma, remains controversial. To determine the role of plasma PAF-AH in airway physiology, we performed PAF bronchoprovocation tests in 8 plasma PAF-AH-deficient subjects and 16 control subjects. Serial inhalation of PAF (1-1000 microg/ml) concentration-dependently induced acute bronchoconstriction, but there was no significant difference between PAF-AH-deficient and control subjects (11.7 +/- 4.6% vs. 9.6 +/- 2.8% decrease in forced expiratory volume in 1 s). Transient neutropenia after single inhalation of PAF (1000 microg/ml) showed no significant difference between the groups either in its magnitude (72 +/- 11% vs. 65 +/- 9% decrease) or duration (4.1 +/- 1.0 vs. 3.3 +/- 0.8 min). In conclusion, a lack of plasma PAF-AH activity alone does not augment physiological responses to PAF in the airway.