Activation and transforming growth factor-beta production in eosinophils by hyaluronan

To investigate whether extracellular matrix glycosaminoglycan hyaluronan (HA) modulates eosinophil activation and transforming growth factor (TGF)-beta production by eosinophils, human peripheral blood eosinophils (purity > 99%) from 12 patients with mild to moderate asthma or six healthy subjects were isolated and incubated with increasing concentrations of low molecular weight (mol wt) HA ( approximately 0.2 x 10(6) D) or high mol wt HA (3.0 to approximately 5.8 x 10(6) D). We found that the low mol wt HA has a pronounced effect on eosinophil survival in both patients with asthma and healthy subjects in a dose-dependent fashion on Days 2 and 4. Whereas the high mol wt HA had a smaller effect on eosinophil survival than did the low mol wt HA. The HA-mediated eosinophil survival was partially but significantly inhibited ( approximately 50% inhibition) by a blocking monoclonal antibody for CD44, a specific receptor of HA, and largely inhibited by an anti-granulocyte macrophage colony-stimulating factor (GM-CSF) neutralizing antibody but not by an anti-interleukin (IL)-3 or anti-IL-5 neutralizing antibody. In addition, the low mol wt HA increased GM-CSF messenger RNA (mRNA) expression and protein secretion by eosinophils in a dose-dependent fashion, suggesting that the HA-mediated eosinophil survival is due mainly to induction of GM-CSF release through partial CD44 signaling. Furthermore, we demonstrated that the low mol wt HA results in morphologic changes in eosinophils such as transforming from a round to a spindle shape and in homotypic aggregation, upregulates intercellular adhesion molecule-1 expression, and increases TGF-beta mRNA expression and protein secretion by eosinophils. These observations suggest previously unforeseen interactions between eosinophils and low mol wt extracellular matrix and, thus, novel pathways by which eosinophils may contribute to the regulation of airway inflammation and airway remodeling.

Role of pertussis toxin-sensitive G protein in metabolic vasodilation of coronary microcirculation

We have previously demonstrated that pertussis toxin (PTX)-sensitive G protein (G(PTX)) plays a major role in coronary microvascular vasomotion during hypoperfusion. We aimed to elucidate the role of G(PTX) during increasing metabolic demand. In 18 mongrel dogs, coronary arteriolar diameters were measured by fluorescence microangiography using a floating objective. Myocardial oxygen consumption (MVO(2)) was increased by rapid left atrial pacing. In six dogs, PTX (300 ng/ml) was superfused onto the heart surface for 2 h to locally block G(PTX). In eight dogs, the vehicle (Krebs solution) was superfused in the same way. Before and after each treatment, the diameters were measured during control (130 beats/min) and rapid pacing (260 beats/min) in each group. Metabolic stimulation before and after the vehicle treatment caused 8.6 +/- 1. 8 and 16.1 +/- 3.6% dilation of coronary arterioles <100 microm in diameter (57 +/- 8 microm at control, n = 10), respectively. PTX treatment clearly abolished the dilation of arterioles (12.8 +/- 2. 5% before and 0.9 +/- 1.6% after the treatment, P < 0.001 vs. vehicle; 66 +/- 8 microm at control, n = 11) in response to metabolic stimulation. The increases in MVO(2) and coronary flow velocity were comparable between the vehicle and PTX groups. In four dogs, 8-phenyltheophylline (10 microM, superfusion for 30 min) did not affect the metabolic dilation of arterioles (15.3 +/- 2.0% before and 16.4 +/- 3.8% after treatment; 84.3 +/- 11.0 microm at control, n = 8). Thus we conclude that G(PTX) plays a major role in regulating the coronary microvascular tone during active hyperemia, and adenosine does not contribute to metabolic vasodilation via G(PTX) activation.

Methacholine bronchial hyperresponsiveness in chronic sinusitis

The coexistence of chronic sinusitis (CS) may deteriorate the clinical condition of lower airway diseases such as bronchial asthma (BA) or chronic bronchitis (CB). However, the bronchial hyperresponsiveness (BH) in CS without any apparent lower airway disease is not fully understood nor are the effects of treatment. We examined lower airway hyperresponsiveness to methacholine (MCh) in 42 subjects with CS but without allergic rhinitis (AR) who had normal lung functions without any pulmonary symptoms, comparing it with that of 50 subjects with stable BA, 50 subjects with simple CB and 40 subjects with AR, and further examined the effect of endoscopic sinus surgery in 7 CS subjects with BH. The BH to MCh was measured in terms of the minimum dose (Dmin), defined as the cumulative dose at the point where respiratory conductance began to decrease. A Dmin <50 units was defined as BH. Seventy-one percent of CS subjects showed BH without relation to the severity or duration of CS, or atopic status. BH in CS subjects, which was less than that in BA subjects, was similar to that in simple CB or AR in both its prevalence and degree. After the surgical treatment of CS, BH significantly decreased (p < 0.01) with improvements in both nasal symptoms and sinus lesions. These findings suggest that CS itself induces BH to a degree similar to simple CB and AR without any relationship to the clinical background, and that adequate treatment of CS reduces BH.

Increase in reactive nitrogen species production in chronic obstructive pulmonary disease airways

Peroxynitrite, nitrogen dioxide, and other reactive nitrogen species (RNS) that are formed in the reaction of nitric oxide (NO) with superoxide anion, and in peroxidase-dependent mechanisms, have a potent inflammatory action. These molecules may therefore increase in number and have a role in inflammatory airway diseases. In the present study, we quantified RNS using immunostaining of nitrotyrosine and inducible NO synthase (iNOS) in airway inflammatory cells obtained by the induced sputum technique, and also quantified the exhaled NO concentration in subjects with chronic obstructive pulmonary disease (COPD), subjects with asthma, and healthy subjects (HS). Immunoreactivity for iNOS observed in the airway inflammatory cells was significantly and similarly higher in subjects with COPD and asthma than in HS, although exhaled NO levels were increased only in subjects with asthma. Inflammatory cells showed obvious nitrotyrosine immunoreactivity in subjects with COPD and to a lesser extent in those with asthma, but not in HS. There was a significant negative correlation between the percent predicted values of FEV(1) and the amount of nitrotyrosine formation in subjects with COPD, but not in those with asthma and HS. These results suggest that: (1) RNS may be involved in the pathobiology of the airway inflammatory and obstructive process in COPD; and (2) NO produced in the airways, presumably via iNOS, is consumed by its reaction with superoxide anion and/or peroxidase-dependent mechanisms.

The mouse L-histidine decarboxylase gene: structure and transcriptional regulation by CpG methylation in the promoter region

To investigate the regulation of mouse L-histidine decarboxylase (HDC) gene expression, we isolated genomic DNA clones encoding HDC. Structural analysis revealed that the mouse HDC gene was composed of 12 exons, spanning approximately 24 kb. Northern blotting analysis indicated that, among the cell lines examined, a high level of HDC gene expression was restricted to mature mast cell lines and an erythroblastic cell line. The gene was induced strongly in the mouse immature mast cell line P815 after incubation in the peritoneal cavity of BDF1 mice. We observed that the promoter region was demethylated in the HDC-expressing cell lines and in induced P815 cells. Interestingly, forced demethylation by 5-azacytidine (5-azaC) treatment induced high expression of HDC mRNA in P815 cells. The activity of a mouse HDC promoter-reporter construct stably transfected in P815 cells was repressed by in vitro patch-methylation. This low promoter activity of the patch-methylated reporter construct was restored after 5-azaC treatment, which demethylated the patch-methylated promoter. These results indicate that DNA methylation state of the promoter region controls HDC gene expression.

Transcriptional control of adrenomedullin induction by phorbol ester in human monocytic leukemia cells

Adrenomedullin is a potent vasodilator peptide that was originally identified from human pheochromocytoma. In this study, we investigated the induction of adrenomedullin gene expression in THP-1 acute monocytic leukemia cells during differentiation into macrophage-like cells by 12-O-tetradecanoylphorbol-13-acetate (TPA), and identified a cis-regulatory region of the human adrenomedullin gene responsible for TPA-induced adrenomedullin expression. Upon treatment with TPA (100 ng x mL(-1)) for 24 h, immunoreactive adrenomedullin concentrations in the culture medium and adrenomedullin mRNA levels were increased more than 10-fold, concomitant with the differentiation of THP-1 cells into macrophage-like cells. Actinomycin D abolished the TPA-induced adrenomedullin expression, indicating that the induction of ADM gene expression by TPA was regulated at the transcriptional level. Transient transfection assay revealed that a cis-acting region (positions -70 to -30) of human adrenomedullin gene was necessary for TPA-induced reporter gene expression. This region contains multiple copies of activator protein 2 (AP-2) binding sites, which are bound by purified AP-2 protein, as judged by electrophoretic mobility shift assay. The binding activity to this region was undetectable in nuclear extracts prepared from untreated THP-1 cells, but was increased in extracts prepared from TPA-treated cells. The protein binding was abolished by unlabeled oligonucleotides containing the AP-2 consensus sequence. These results indicate that the region (-70 to -30) of the human ADM gene containing multiple AP-2 binding sites is responsible for TPA-induced adrenomedullin expression in THP-1 cells.

Coronary microcirculation: physiology and pharmacology

Coronary microvessels play a pivotal role in determining the supply of oxygen and nutrients to the myocardium by regulating the coronary flow conductance and substance transport. Direct approaches analyzing the coronary microvessels have provided a large body of knowledge concerning the physiological and pharmacological characteristics of the coronary circulation, as has the rapid accumulation of biochemical findings about the substances that mediate vascular functions. Myogenic and flow-induced intrinsic vascular controls that determine basal tone have been observed in coronary microvessels in vitro. Coronary microvascular responses during metabolic stimulation, autoregulation, and reactive hyperemia have been analyzed in vivo, and are known to be largely mediated by metabolic factors, although the involvement of other factors should also be taken into account. The importance of ATP-sensitive K(+) channels in the metabolic control has been increasingly recognized. Furthermore, many neurohumoral mediators significantly affect coronary microvascular control in endothelium-dependent and -independent manners. The striking size-dependent heterogeneity of microvascular responses to all of these intrinsic, metabolic, and neurohumoral factors is orchestrated for optimal perfusion of the myocardium by synergistic and competitive interactions. The regulation of coronary microvascular permeability is another important factor for the nutrient supply and for edema formation. Analyses of collateral microvessels and subendocardial microvessels are important for understanding the pathophysiology of ischemic hearts and hypertrophied hearts. Studies of the microvascular responses to drugs and of the impairment of coronary microvessels in diseased conditions provide useful information for treating microvascular dysfunctions. In this article, the endogenous regulatory system and pharmacological responses of the coronary circulation are reviewed from the microvascular point of view.

Regulation of murine airway eosinophilia and Th2 cells by antigen-conjugated CpG oligodeoxynucleotides as a novel antigen-specific immunomodulator

The characteristic features of bronchial asthma reflect the orchestrated activity of Th2 cells. Oligodeoxynucleotides containing CpG motifs (CpG) have recently been highlighted as an immunomodulator that biases toward a Th1-dominant phenotype. We have previously reported that intratracheal coadministration of CpG and allergen inhibited airway eosinophilia and hyperresponsiveness in a synergistic manner. To substantiate the synergism between CpG and Ag, we introduced a covalently linked conjugate between CpG and Ag and examined the efficacy on airway eosinophilia and Th2 cytokine production. We found that the conjugated form of CpG plus Ag was 100-fold more efficient in regulating airway eosinophilia than the unconjugated mixture. The inhibitory effects lasted for at least 2 mo. The inhibition of airway eosinophilia by the conjugate was Ag specific and associated with an improvement of the airway hyperresponsiveness and the unresponsiveness of the Ag-specific Th2 cells in the regional lymph nodes. The CpG-Ag conjugate was 100-fold more effective than the unconjugated mixture for inducing in vitro Th1 differentiation in an IL-12-dependent manner. Our data show that CpG conjugated to Ag can work as a novel Ag-specific immunomodulator and imply that inhalation of allergen-CpG conjugate could be a desensitization therapy for patients with bronchial asthma.

Platelet-derived growth factor, basic fibroblast growth factor, and interferon gamma increase type IV collagen production in human fetal mesangial cells via a transforming growth factor-beta-dependent mechanism

BACKGROUND

Glomerulosclerosis is characterized by glomerular accumulation of extracellular matrix following mesangial cell proliferation. The precise pathomechanism of glomerulosclerosis is still undetermined. Platelet-derived growth factor (PDGF) and basic fibroblast growth factor (b-FGF) are known to be mitogenic for mesangial cells, and interferon gamma (IFN-gamma) is known to have an inhibitory effect on mesangial cell proliferation. We attempted to clarify the role of these cytokines on mesangial matrix production using cultured human fetal mesangial cells (HMC).

METHODS

HMC were incubated with these cytokines for 24-72 h and the levels of type IV collagen and TGF-beta in the cell supernatants were measured by enzyme immunoassay.

RESULTS

PDGF, b-FGF, and IFN-gamma stimulated type IV collagen production by HMC in a dose- and time-dependent manner. The anti-TGF-beta neutralizing antibody clearly inhibited their stimulatory effect on type IV collagen production. PDGF and b-FGF also stimulated TGF-beta production by HMC in a dose-dependent manner, although IFN-gamma did not.

CONCLUSION

PDGF, b-FGF, and IFN-gamma stimulate type IV collagen production in cultured HMC via a TGF-beta-dependent mechanism.

Repression of heme oxygenase-1 by hypoxia in vascular endothelial cells

Heme oxygenase 1 (HO-1), a rate-limiting enzyme in heme catabolism, has been reported to be induced by hypoxia. Unexpectedly, here we show that expression of HO-1 mRNA is repressed by hypoxia in primary cultures of human umbilical vein endothelial cells (HUVECs), but is increased by cobalt chloride (CoCl(2)) that is known to mimic hypoxia. Under the culture conditions used, the DNA-binding and transactivation activities of hypoxia-inducible factor 1 were increased in HUVECs by hypoxia or CoCl(2). Therefore, hypoxia and cobalt showed opposing effects on HO-1 mRNA expression, despite activation of hypoxia-inducible factor 1. The half-life of HO-1 mRNA was not changed by hypoxia, but was significantly prolonged by CoCl(2). Hypoxia also represses HO-1 mRNA expression in human coronary artery endothelial cells and astrocytes. The repression of HO-1 expression may represent the adaptation to hypoxia in certain cell types.

Effect of a calcium sensitization modulator, Y-27632, on isolated human bronchus and pulmonary artery

A recently developed pyridine derivative, Y-27632, has been reported to inhibit smooth muscle contraction by inhibiting Ca(2+)sensitization in animal experiments. However, the effect of this compound in human tissues has not yet been elucidated. The aim of the present study was to evaluate the effect of Y-27632 on human bronchi and pulmonary arteries. The tissues were obtained from lung cancer patients undergoing lung resection. Tissue responses were assessed by isometric tension measurement. Y-27632 relaxed the bronchi at basal tone with an IC(50)(concentration causing 50% relaxation of the maximal response) of 2.0+/-0.3x10(-6)M. Y-27632 also dose-dependently relaxed the bronchi precontracted by acetylcholine (ACh), histamine and neurokinin A, and the IC(50)was 3.0+/-0.4x10(-6), 2.5+/-0.5x10(-6)and 1.8 +/-0.3x10(-6)M, respectively. The dilatory effect of Y-27632 was significantly smaller in ACh-precontracted tissues compared with those of basal or histamine- and neurokinin A-induced precontracted bronchi (P<0.05). Further, Y-27632 showed an inhibitory effect on cholinergic nerve stimulation- and ACh-induced bronchial contraction to the same degree, suggesting that a modulatory effect of this compound on ACh release from nerve terminals was unlikely. Y-27632 also dilated the pulmonary arteries precontracted by phenylephrine (IC(50)= 1.6+/-0.1x10(-6)M). These data suggest that Y-27632 has a dilatory capacity on human bronchi as well as on pulmonary arteries.

Characterization of platelet-activating factor-induced cytosolic calcium mobilization in human eosinophils

BACKGROUND

Activated eosinophils play an important role in the pathogenesis of bronchial asthma and other allergic diseases, and platelet-activating factor (PAF) is a potent activator of eosinophils.

OBJECTIVE

To characterize the cytosolic Ca2+ ([Ca2+]i) mobilization in human eosinophils in response to PAF.

METHODS

[Ca2+]i responses to PAF were examined in human eosinophils using a microscopic fura-2 fluorescence-ratio imaging system.

RESULTS

PAF caused a significant and dose-dependent increase in (Ca2+)i, which consisted of an initial rapid rise followed by a sustained elevation. This PAF-induced (Ca2+)i rise was inhibited by WEB 2086, a specific PAF receptor antagonist. The addition of 5 mM EGTA or 1 mM Ni2+ to a nominally Ca2+-free solution did not appreciably reduce the initial rise but significantly inhibited the sustained rise. The application of a protein kinase C inhibitor, Ro31-8220, augmented the sustained increase by PAF. Thapsigargin, a microsomal Ca2+ ATPase inhibitor, induced no appreciable change in a nominally Ca2+-free solution but induced a marked increase in (Ca2+)i when changed to a Ca2+-containing solution.

CONCLUSIONS

The initial rapid rise and the following sustained rise in (Ca2+)i by PAF depends on Ca2+ release from the intracellular Ca2+ stores and Ca2+ influx, respectively, which are regulated by protein kinase C in human eosinophils. Furthermore, the so called Ca2+-capacitative entry is possibly involved in the Ca2+ influx from the extracellular solution in human eosinophils.

A novel function of thyrotropin as a potentiator of electrolyte secretion from the tracheal gland

Accumulating evidence suggests that thyrotropin (thyroid-stimulating hormone [TSH]) plays some roles in immunoregulation by an extrathyroidal action. Because airway submucosal glands are responsible for nonspecific and specific airway defense, we tested the effect of TSH on feline tracheal submucosal gland using a whole-cell patch-clamp technique, immunohistochemistry, and reverse transcription/polymerase chain reaction (RT-PCR). TSH potentiated neurotransmitter-induced ionic currents significantly in a dose-dependent manner. Acetylcholine (10(-)(8) M)- and norepinephrine (10(-)(7) M)-induced inward current (I(i)), which we previously showed to be a Cl(-) current, were increased to about 3-fold the pre-TSH control responses, respectively, by 2.0 ng/ml TSH; and to 6- and 23-fold the control values by 20.0 ng/ml TSH, respectively. TSH alone was without effect up to 20.0 ng/ml. Follicular stimulating hormone only slightly affected the I(i) (1. 5-fold the control). Analyses with immunohistochemistry and RT-PCR failed to identify TSH receptors on the glandular tissue. Maneuvers to raise the cellular adenosine 3',5'-cyclic monophosphate also failed to mimic the TSH-mediated potentiation. The TSH effect appeared to be mediated by a signaling pathway involving tyrosine kinase because its inhibitors (genistein and herbimycin A) abolished the augmentation completely, and interferon-gamma, a tyrosine kinase activator, imitated the TSH action on submucosal gland. Thus, TSH may be an important regulator of airway fluid secretion.

Suppression of maxi-K channel and membrane depolarization by synthetic polycations in single tracheal myocytes

Polycationic proteins, e.g., major basic protein from eosinophils or cathepsin G from neutrophils, have been shown to increase nonspecific airway responsiveness. Along with several indirect manners of action, polycations were reported to contract smooth-muscle strips and to raise the cellular Ca(2+) concentration as a direct action on airway smooth muscle. However, the mechanistic basis for the direct behavior remains to be elucidated. To address this issue, we examined the effects of synthetic cationic polypeptides poly-L-arginine and poly-L-lysine on fresh single smooth-muscle cells from bovine trachea using a patch-clamp technique. Both of the polycations significantly depolarized the membrane from a baseline of about -40 to -20 mV in a dose-dependent manner. The polycations also suppressed whole-cell spontaneous transient outward currents as well as both the conductance (from a baseline of about 130 to 70 pS) and open-state probability (about 25% of control values) of large-conductance Ca(2+)-dependent K(+) channel (maxi-K channel) on excised outside-out patch membranes. The polycations were without effect on the whole-cell Ca(2+) currents induced by depolarizing voltage pulses. We concluded that the synthetic polycations had at least two sites of action; one is the delayed rectifier K(+) channel that is responsible for the membrane depolarization that increases Ca(2+) influx, and the other is the maxi-K channel the suppression of which inhibits muscle relaxation. These results may explain the direct contractile action and, therefore, one of the mechanisms underlying the airway hyperresponsiveness induced by various polycationic proteins.

Long-term right ventricular volume overload increases myocardial fluorodeoxyglucose uptake in the interventricular septum in patients with atrial septal defect

BACKGROUND

Several studies have shown that long-term right ventricular (RV) overload in animal models alters myocardial energy substrate metabolism. However, whether long-term RV volume overload alters this metabolism in the human is unclear.

METHODS AND RESULTS

We performed positron emission tomography with [(18)F]fluorodeoxyglucose (FDG) and single-photon emission tomography (SPECT) with [(201)Tl]TlCl (Tl) and [(123)I]15-(p-iodophenyl)-3-R,S-methylpentadecanoic acid (BMIPP) in 11 patients with atrial septal defect (ASD) and 11 control subjects. In the FDG study, we calculated myocardial metabolic rate of glucose (MMR) in interventricular septum (IVS) and left ventricular (LV) free wall. MMR was significantly increased in IVS compared with LV free wall in the ASD patients (420+/-35 versus 333+/-32 mol x kg(-1) x min(-1); P<0.05) but not in the control group (347+/-27 versus 357+/-25 mol x kg(-1) x min(-1)). In both ASD and control groups, SPECT count was not significantly different between IVS and LV free wall in Tl (ASD, 160+/-11 versus 177+/-12; control, 141+/-12 versus 157+/-14 counts per 15 minutes) and BMIPP studies (ASD, 203+/-14 versus 212+/-18; control, 162+/-16 versus 176+/-16 counts per 15 minutes). MMR in the IVS/LV free wall ratio in the ASD group significantly correlated with indices related to RV volume overload.

CONCLUSIONS

Given the assumption that long-term RV volume overload did not affect the lumped constant, the present study suggests that, unlike myocardial perfusion or fatty acid analogue uptake, myocardial glucose utilization in IVS relative to LV free wall is increased in relation to long-term RV volume overload in patients with ASD.

Safety and efficacy of the neuraminidase inhibitor zanamivir in treating influenza virus infection in adults: results from Japan. GG167 Group

The study was carried out to evaluate the therapeutic effects of zanamivir, a highly selective, potent and specific inhibitor of influenza A and B virus neuraminidases, in adult patients with acute influenza-like illness. Patients who presented within 36 h of the onset of influenza-like symptoms were randomly assigned to receive one of three treatments, twice daily, for 5 days: 10 mg zanamivir powder for inhalation (zanamivir inhalation group), 10 mg zanamivir powder for inhalation plus 6.4 mg zanamivir nasal spray (zanamivir inhalation plus intranasal group) or placebo (placebo group). The primary end point was the time to alleviation of the three major symptoms (fever, headache and myalgia). The secondary end point was the time to alleviation of five influenza symptoms (fever, headache, myalgia, cough and sore throat). One hundred and sixteen patients with influenza-like illness were recruited to the study. No differences were observed between the two groups of patients who received zanamivir (inhalation group or inhalation plus intranasal group). Patients who received zanamivir recovered significantly faster (median 3 days to recovery) than the patients in the placebo group (median 4 days to recovery; P < 0.01). Topically administered zanamivir was well tolerated. This study confirms that in adults, topically administered zanamivir is well tolerated and is effective in reducing the time to alleviation of influenza symptoms.

Regional and temporal profiles of phorbol 12,13-dibutyrate binding after myocardial infarction in rats: effects of captopril treatment

Phosphoinositide turnover and protein kinase C (PKC) mediate the signaling of angiotensin II, which plays a pivotal role in ventricular remodeling after myocardial infarction (MI). To determine whether PKC is activated after MI, rat hearts after MI were subjected to in vitro quantitative autoradiography with [3H]phorbol 12,13-dibutyrate (PDBu), which is highly selective for PKC. [3H]PDBu binding in the infarcted area increased significantly compared with the non-infarcted region 7 and 21 days after MI, but not 1 and 3 days and 10 months after MI. [3H]PDBu binding in the noninfarcted area was similar to that in the sham-operated rats. Immunohistochemical analysis revealed that abundant macrophages (7 days after MI), fibroblasts, and myofibroblasts (7 and 21 days after MI) occupied the infarcted region. To investigate whether myocardial [3H]PDBu binding is affected by captopril, hearts were subjected to in vitro autoradiography with [3H]PDBu after 1- or 3-week captopril treatment or no treatment. Captopril treatment significantly suppressed [3H]PDBu binding in the infarcted area 3 weeks after MI, but not 1 week after MI nor in the noninfarcted areas. These results suggest that PKC is upregulated during the healing and fibrogenic process after MI and that captopril treatment suppresses the upregulation in the infarcted area.

Regulation of T-helper type 2 cell and airway eosinophilia by transmucosal coadministration of antigen and oligodeoxynucleotides containing CpG motifs

The characteristic features of bronchial asthma, including airway eosinophilia and elevated immunoglobulin (Ig)E levels, are known to be orchestrated by T-helper (Th) 2 cells. Oligodeoxynucleotides containing CpG motifs (CpG) have recently been highlighted as an immunomodulator that biases toward a Th1-dominant phenotype. However, CpG may incur nonspecific Th1 activation and toxic effects. In this study we report a novel inhibition of Th2 cells by transmucosal inoculation of antigen and CpG. Intratracheal instillation of CpG inhibited airway eosinophilia and Th2 cytokine production in antigen-sensitized mice. The inhibition was observed when CpG was given at the same time or in advance of antigen challenge. Notably, concomitant administration of CpG and antigen (as opposed to either one alone) was essential for the inhibitory effects. The antigen dose could be minimized to avoid a harmful boost of eosinophilia. CpG had few effects on systemic anti-ovalbumin IgE responses. These results demonstrate that a synergism between transmucosally administered allergen and CpG inhibits Th2 cells in parallel with an improvement in airway eosinophilia and hyperresponsiveness without impeding systemic immune responses. Our data imply that inhalation of a minimal amount of allergen plus CpG could be a novel desensitization therapy for patients with bronchial asthma.

Effects of nasal continuous positive airway pressure on awake ventilatory responses to hypoxia and hypercapnia in patients with obstructive sleep apnea

This study was aimed to examine the short- and long-term effects of nasal continuous positive airway pressure (CPAP) on the chemosensitivity to hypoxia and hypercapnia in the patients with obstructive sleep apnea (OSA). Awake ventilatory responses to hypoxia and hypercapnia were examined in 28 patients (3 female) with moderate to severe OSA. All these tests were examined before and after 2 weeks of nasal CPAP. In 10 patients these tests were repeated after 3-6 months of nasal CPAP. All were also tested for spirometry and arterial blood gas analysis. Patients were middle-aged (48.9 +/- 9.9 years) and their mean apnea-hypopnea index was 58.3 +/- 20.4/hour. After 2 week of nasal CPAP, PaO2 significantly increased (77.7 +/- 11.8 vs. 84.6 +/- 9.8 mmHg) and PaCO2 significantly decreased (44.9 +/- 3.8 vs. 42.3 +/- 3.7 mmHg). The ventilatory response to hypoxia significantly decreased (0.80 +/- 0.51 vs. 0.61 +/- 0.51 liter/min/%) whereas the ventilatory response to hypercapnia significantly increased after 2 weeks (1.47 +/- 0.73 vs. 1.80 +/- 0.76 liter/min/mmHg). Similar findings were also observed after 3-6 months of nasal CPAP in 10 OSA patients. Nasal CPAP treatment can alter the ventilatory responses in patients with OSA.

Baseline airway hyperresponsiveness and its reversible component: role of airway inflammation and airway calibre

Airway hyperresponsiveness (AHR), in which airway inflammation has been reported to be a key factor, is an important component of asthma. However the precise role of inflammation in AHR is still unclear. In this report, airway inflammatory changes were assessed using hypertonic saline-induced sputum examination and exhaled nitric oxide analysis, and the relation between AHR to methacholine, airway calibre forced expiratory volume in one second (FEV1) and airway inflammatory indices examined. Furthermore, the changes in these variables were also examined by means of 8 weeks' open uncontrolled inhaled steroid administration (800 microg x beclomethasone x day(-1)). Asthmatic subjects had higher eosinophil counts and bradykinin concentration in induced sputum and higher exhaled NO levels, and showed AHR to methacholine. Baseline AHR significantly correlated with FEV1 but not with indices of inflammation in sputum or exhaled air. Steroid inhalation therapy was associated with a reduction in eosinophil and bradykinin concentration in sputum and NO levels in exhaled air and an improvement in FEV1 and AHR. The changes in FEV1 and AHR were significantly related to changes in markers in sputum and exhaled air (p<0.01 for each). These results suggest that baseline airway hyperresponsiveness can be predicted from the airway calibre but not from inflammatory parameters in sputum or exhaled air. In contrast, the reversible component of airway hyperresponsiveness appeared to be associated with the reduction in airway inflammation.

Expression of Glut-4 and Glut-1 transporters in rat diaphragm muscle

Glucose transporters (Gluts) are a family of membrane proteins responsible for the transport of glucose across cellular membranes. Generally, alterations of Gluts expression in limb skeletal muscle have been reported. However, the changes of Glut isoforms in respiratory muscle which contracts with a duty cycle have rarely been studied. This study was performed to evaluate at the light microscopy level the expression of Glut-4 and Glut-1 transporters in normal and denervated diaphragm by immunohistochemistry method with specific Gluts antibodies. The results showed Glut-4 immunoreactivity in both the cell periphery and the interior of myocytes. Glut-1 was also present in the cell border and in the interior of myocytes in control diaphragm. However, Glut-4 staining was stronger than Glut-1 staining in control diaphragm. In denervated hemidiaphragm, the Glut-4 immunolabelling decreased and Glut-1 increased. These data indicated that (1) Glut-4 and Glut-1 transporters were observed in diaphragm; and (2) there were alterations in the expression of both glucose transporters after denervation. These alterations in Glut isoforms after denervation may be associated with the removal of innervation itself, and/or may partly result from passive stretch imposed by inspiratory activation of the contralateral side.

Nocturnal blood pressure during apnoeic and ventilatory periods in patients with obstructive sleep apnoea

The exact nature of asleep blood pressure in relation to awake blood pressure is still unclear in patients with obstructive sleep apnoea. This study aimed: 1) to investigate the asleep blood pressure in both apnoeic and ventilatory periods; 2) to determine the diurnal and nocturnal factors correlated with the changes in blood pressure from apnoea to ventilatory periods during sleep. Thirty-two patients, newly diagnosed as moderate to severe obstructive sleep apnoea with a standard nocturnal polysomnography, were enrolled. The blood pressure was monitored by using the noninvasive continuous monitoring method during polysomnographic study. The mean blood pressures in ventilatory periods during nonrapid eye movement (NREM) and rapid eye movement (REM) sleep were 117.5+/-17.9 mm Hg and 128.8+/-21.9 mm Hg, and those in apnoea periods were 94.5+/-15.4 mm Hg and 102.7+/-19.0 mm Hg. The average blood pressure during NREM sleep (103.0+/-16.1 mm Hg) was higher than the awake blood pressure (97.0+/-15.7 mm Hg). The blood pressure during REM sleep was greater than that during NREM sleep. The changes in the nocturnal blood pressure from apnoea to ventilatory periods were inversely correlated with the age and nocturnal mean nadir saturation. In conclusion, patients with obstructive sleep apnoea have higher asleep blood pressure than awake blood pressure.

[Effects of an ATP-sensitive K+ channel activator, JTV-506, on antigen-induced early and late asthmatic responses in sensitized guinea pigs]

Effects of an ATP-sensitive K+ channel activator, JTV-506, on dual asthmatic responses and airway inflammation after antigen inhalation challenge were investigated in asthma model of guinea pigs. The animals were given an oral dose of 1 mg/kg of JTV-506 or vehicle (0.5% carboxymethyl cellulose sodium) 1 hour before and 3 hours after antigen inhalation challenge. Measurement of pulmonary resistance for 6 h was followed by bronchoalveolar lavage. After antigen challenge, all guinea pigs in the vehicle group displayed dual-phase airway obstruction and accumulation of eosinophils in the airways. After the treatment with JTV-506, the early asthmatic response was significantly inhibited, although the late asthmatic response or the recruitment of eosinophils into the airways were not inhibited. Therefore, we suggested that JTV-506 may inhibit airway smooth contraction induced by chemical mediators, but not function of CD4+ T lymphocytes.

Diacylglycerol delays pH(i) overshoot after reperfusion and attenuates contracture in isolated, paced myocytes

Although protein kinase C (PKC) plays a pivotal role in ischemic preconditioning, it is not clear what the end effector is that protects the myocardium. In isolated, paced (1.25 Hz, 36-37 degrees C) adult rat cardiomyocytes, the effects of PKC preactivation by diacylglycerol on cell motion, intracellular Ca(2+) concentration ([Ca(2+)](i); indo 1), and intracellular pH (pH(i); seminaphthorhodafluor-1) during simulated ischemia-reperfusion (I/R) were investigated. The degree of reperfusion-induced contracture was significantly attenuated in the myocytes pretreated with 10 microM 1, 2-dioctanoyl-sn-glycerol (DOG; n = 19) compared with the untreated myocytes (n = 23, P < 0.02). There were no differences in twitch amplitude, end-diastolic [Ca(2+)](i), or peak-systolic [Ca(2+)](i) during I/R between the DOG-pretreated and untreated myocytes. Although there were no differences in pH(i) during ischemia, the pH(i) overshoot during reperfusion was significantly delayed in the DOG-pretreated myocytes compared with the untreated myocytes (n = 17 for each, P < 0.01). Chelerythrine completely abolished the favorable effects of DOG on the reperfusion-induced contracture and the pH(i) overshoot. These data suggest that diacylglycerol attenuates I/R injury in isolated, paced cardiomyocytes, which may be related to the slower pH(i) overshoot during reperfusion.