Overexpression of insulin-like growth factor-I in hearts of rats with isoproterenol-induced cardiac hypertrophy

Increased levels of plasma catecholamine lead to cardiac hypertrophy via the alpha-, beta-adrenergic receptors, and partially, type 1 angiotensin II (AT1) receptor. However, it remains unclear whether other factors are involved in catecholamine-induced cardiac hypertrophy. We investigated the expression of insulin-like growth factor (IGF)-I in hearts of male Wistar rats infused with a beta-adrenergic agent, isoproterenol (ISO) (3 mg/kg/day), with or without an AT1-receptor antagonist, TCV-116 (10 mg/kg/day). Cardiac myocytes became hypertrophied 1 day after the beginning of ISO administration. ISO induced a biphasic increase of cardiac myocytes positive for IGF-I protein in the early and late phases of the study period, whereas IGF-I gene expression was upregulated only in the late phase by ISO. TCV- 116 abolished the upregulation of IGF-I gene and protein expression in the late phase in association with the regression of cardiac hypertrophy. These results suggest that ISO-induced cardiac hypertrophy is mediated, at least in part, by IGF-I, the expression of which is upregulated through the activation of AT1 receptor.

Bradykinin B2 antagonist HOE 140 inhibits late allergic microvascular leakage in guinea pig airways

Because bradykinin has potent inflammatory actions, this molecule may be involved in the late allergic response (LAR). We investigated the role of the molecule in airway microvascular hyperpermeability during the LAR. Three weeks after ovalbumin (OVA) sensitization, animals were pretreated with bradykinin B2 receptor antagonist HOE 140 or vehicle for 30 min before the OVA inhalation challenge. The occurrence of LAR was judged by a two-fold increase in transpulmonary pressure (Ptp) from the baseline values. The microvascular permeability in the trachea was assessed by an index defined as the ratio of the area of vasculature labeled by the Monastral blue dye (area density percent). Significant microvascular hyperpermeability were observed during the LAR. The bradykinin concentrations in the bronchoalveolar lavage-fluid (BAL-f) were increased during the LAR. HOE 140 (0.1-10 mg/kg, s.c.) inhibited the airway microvascular hyperpermeability during the LAR dose-dependently. These findings suggest that bradykinin may play an important role in microvascular hyperpermeability during the LAR.

Arg506Gln mutation of the coagulation factor V gene not detected in Japanese pulmonary thromboembolism

The incidence of pulmonary thromboembolism (PTE) is lower in Japanese than in Caucasians. The basis for the different incidence has not been clarified. A poor anticoagulant response to activated protein C based on a single point mutation of the factor V gene (Arg506Gln) was found to be a pathogenetic factor for venous thrombosis and PTE in North America and Europe. We investigated whether the Arg506Gln mutation of factor V is responsible for the occurrence of PTE among Japanese. We analyzed genomic DNA prepared from fresh peripheral blood of 25 patients with PTE of unknown etiology (12 of acute type and 13 of chronic type) and that of 110 controls without respiratory or circulatory disorders. To detect the Arg506Gln mutation, 267 bp DNA fragments of the factor V gene including the Arg506Gln region were amplified by PCR, digested by MnlI and electrophoresed. After digestion of PCR products with MnlI, DNA fragments of 163 bp length, but not DNA fragments of 200 bp length, were identified in all samples, indicating the absence of the Arg506Gln mutation in the patients with PTE and control subjects. These results suggest that the Arg506Gln mutation is absent or very rare and not an important pathogenetic factor for PTE in Japanese.

Effects of low doses of endothelin-1 on basal vascular tone and autoregulatory vasodilation in canine coronary microcirculation in vivo

The plasma level of endothelin-1 (ET-1) increases in several cardiovascular disorders. The present study examined whether threshold doses of ET-1 affect vascular tone and autoregulatory vasodilation during a reduction in perfusion pressure in the coronary microcirculation in vivo. In anesthetized open-chest dogs, arterial microvessels in the epimyocardium were observed through a microscope equipped with a floating objective. In 6 dogs, ET-1 (10(-13) to 10(-8)mol/L) was superfused onto the epimyocardium in a cumulative fashion. In another set of dogs (n= 16), the perfusion pressure of the observed vascular bed was reduced to 60 mmHg (mild stenosis) and to 40 mmHg (severe stenosis) by a hydraulic occluder, and the microvascular responses were observed in the presence (n=9) or absence (n=7) of ET-1 (10(-12) or 10(-11) mol/L). ET-1 > or =10(-11) mol/L constricted coronary arterioles (< or =100 microm in diameter) and small arteries (>100 microm in diameter) in a dose-dependent fashion. ET-1 of 10(-12) mol/L affected neither the basal diameters nor the dilation of vessels during the pressure reduction. ET-1 of 10(-11) mol/L decreased the diameters of arterioles and small arteries before and during the mild and severe stenosis. However, ET-1 did not attenuate the percentage dilation of arterioles from the baseline in response to the mild and severe stenosis. The data indicates the following: (1) ET-1 at doses > or =10(-11) mol/L similarly constricts coronary arterioles and small arteries; (2) ET-1 at 10(-11) mol/L, which is slightly higher than the pathophysiological plasma level, increases the basal vascular tone, but does not attenuate the autoregulatory vasodilation of the coronary microcirculation.

Sensory nerve activation in airway microvascular permeability in guinea-pig late allergic response

Because both bradykinin and tachykinins have a potent inflammatory action, these molecules may be involved in the late allergic response. The role of these molecules in airway microvascular permeability during the late allergic response in sensitized guinea-pigs was investigated. Three weeks after ovalbumin sensitization, the animals were pretreated with bradykinin B2 receptor antagonist HOE 140, neurokinin 1 receptor antagonist CP 96,345 or vehicle, 30 min before the ovalbumin inhalation challenge. The occurrence of the late allergic response was determined by a two-fold increase in the transpulmonary pressure from the baseline values. The microvascular permeability in the trachea was assessed by an index defined as the ratio of the area of vasculature labelled by Monastral blue dye (area density %). Significant microvascular permeability and eosinophil accumulation were observed during the late allergic response. Both the bradykinin and substance P concentrations in the bronchoalveolar lavage fluid were increased during the late allergic response. Pretreatment with HOE 140 suppressed the substance P elevation. Both HOE 140 and CP 96,345 also inhibited the airway microvascular permeability during the late allergic response without affecting the eosinophil accumulation in the airways. These findings suggest that bradykinin-mediated sensory nerve activation may play a role in microvascular permeability during the late allergic response in guinea-pigs.

Transforming growth factor-beta secreted from CD4(+) T cells ameliorates antigen-induced eosinophilic inflammation. A novel high-dose tolerance in the trachea

The induction of peripheral tolerance is one of the feasible approaches for the control of autoimmunities and allergies. Tolerance induction in the intestine has been studied extensively and therapeutic applications to autoimmunities are in progress, whereas tolerance in the respiratory tract is poorly investigated. We examined the immunoregulatory mechanisms for evading exaggerated inflammatory responses in the murine airway mucosa. Administration of an optimal dose of ovalbumin (OVA) to the trachea elicited eosinophilic inflammation in the trachea of OVA/aluminum hydroxide-sensitized BALB/c mice, whereas higher doses were unable to do so. This failure paralleled the downregulation of interleukin-4 production by mediastinal lymph node (LN) T cells. This high-dose tolerance was attributable to the mechanisms of antigen (Ag)-specific suppression, because the adoptive transfer of CD4(+) LN T cells from the OVA-tolerant mice inhibited the OVA-specific, but not irrelevant Ag KLH-specific, eosinophilic responses. The inhibitory effects were neutralized by the intratracheal administration of anti-transforming growth factor (TGF)-beta, but not that of anti-interferon (IFN)-gamma, monoclonal antibodies, indicating that the high-dose tolerance was mediated by secreted TGF-beta, but not by the dominance of transferred T helper (Th)1 cells over Th2 cells. The pivotal role of TGF-beta was reinforced by the finding that the LN cells from the OVA-tolerant mice produced TGF-beta in response to the in vitro Ag stimulation. These results demonstrate a novel regulatory mechanism in the airway: that TGF-beta secreted by T cells plays an important role in the downmodulation of the immune responses to high doses of Ag which might otherwise induce deleterious inflammation in the airway mucosal tissues.

Role of peroxynitrite in airway microvascular hyperpermeability during late allergic phase in guinea pigs

We investigated the role of peroxynitrite, which is formed by a rapid reaction between nitric oxide (NO) and superoxide anion (O(2)(-)), in the airway microvascular hyperpermeability during the late allergic response (LAR) in sensitized guinea pigs in vivo. The occurrence of LAR was assessed as a 100% increase in the transpulmonary pressure, which was monitored by the esophageal catheter technique. Airway microvascular permeability was assessed by Monastral blue dye trapping between the endothelium using an image analyzer. In the LAR phase (4 to 6 h after antigen inhalation), microvascular hyperpermeability and eosinophil infiltration within the airway wall were observed. NO production and xanthine oxidase (XO)/xanthine dehydrogenase activity, which are responsible for O(2)(-) production, were enhanced during the LAR. Peroxynitrite formation assessed by nitrotyrosine immunostaining was also exaggerated at that time. The microvascular hyperpermeability during the LAR was largely reduced by NO synthase inhibitor (L-NAME, 72.7% inhibition; p < 0.05), XO inhibitor (AHPP, 60.8% inhibition; p < 0. 05) and peroxynitrite scavenger (ebselen, 81.0% inhibition; p < 0. 05). L-NAME had a small but significant inhibitory effect on airway eosinophil accumulation, but AHPP and ebselen had no effect. These results suggest that excessive production of O(2)(-) and NO occurs in the LAR. These two molecules appear to cause airway microvascular hyperpermeability via peroxynitrite formation.

Adrenomedullin in monocytes and macrophages: possible involvement of macrophage-derived adrenomedullin in atherogenesis

Macrophages secrete a variety of growth factors, cytokines and vasoactive peptides, which are related to the progression of atherosclerosis. Adrenomedullin (ADM) is a potent vasodilator peptide and inhibits proliferation and migration of vascular smooth muscle cells. In this study, we investigated the production and secretion of ADM by monocytes and macrophages by Northern blot analysis, RIA and immunocytochemistry. Northern blot analysis showed that ADM mRNA was expressed in human monocytes obtained from peripheral blood and monocyte-derived macrophages. The expression level of ADM mRNA in monocyte-derived macrophages was about five times higher than that in monocytes. Treatment with lipopolysaccharide (100 ng/ml) for 24 h increased ADM mRNA expression levels in both monocytes and monocyte-derived macrophages. The levels of immunoreactive ADM in the media of monocyte-derived macrophages were about three times higher than that of monocytes (0. 718+/-0.046 fmol/24 h/10(5) cells, n=8 compared with 0.259+/-0.018 fmol/24 h/10(5) cells, n=8; mean+/-S.E.M., P<0.01). The secretion was also increased by treatment with lipopolysaccharide. Immunocytochemistry showed positive ADM immunostaining in macrophages in atherosclerotic lesions of human aorta obtained at autopsy. ADM secreted from activated macrophages may play an inhibitory role in atherogenesis.

Differential expression of alpha 1, alpha 3 and alpha 5 integrin subunits in acute and chronic stages of myocardial infarction in rats

OBJECTIVE

Anchoring cardiac myocytes to extracellular matrix, which is mediated mainly by integrins on their surfaces, is important for maintaining the architecture of myocardial tissues and transmitting mechanical force. We evaluated the expression of alpha integrin subunits on myocytes and the accumulation of interstitial collagen and fibronectin at acute and chronic stages after myocardial infarction.

METHODS

Myocardial infarction was induced by ligation of left coronary arteries in rats. The expression of alpha 1, alpha 3 and alpha 5 integrin subunits, and accumulation of collagen and fibronectin were analyzed with immunohistochemistry or sirius-red staining.

RESULTS

In hearts without infarction, moderate expression of the alpha 3 subunit and only slight expression of the alpha 5 subunit were observed on myocytes. In the first week after infarction, the alpha 1 subunit, collagen and fibronectin were increased only in the peri-infarcted area, while the alpha 5 subunit was increased both in peri-infarcted and non-infarcted areas. At day 42, the expression of the alpha 1 subunit and collagen were still increased, although the alpha 5 subunit and fibronectin were decreased. The expression of the alpha 3 subunit was not altered throughout the experimental period.

CONCLUSION

These data suggest that integrin subunits play an important role in healing and remodeling processes after myocardial infarction.

Induction of heme oxygenase-1 as a response in sensing the signals evoked by distinct nitric oxide donors

To gain insights into the cellular responses evoked by nitric oxide (NO), we have studied the effects of NO donors with distinct chemistries on the expression of heme oxygenase-1 mRNA by northern blot analysis. The expression levels of heme oxygenase-1 mRNA were increased significantly in DLD-1 human colorectal adenocarcinoma cells by treatment with each of three NO donors: sodium nitroprusside (SNP), S-nitroso-L-glutathione (GSNO), and 3-morpholinosydnonimine (SIN-1). A combination of SIN-1 plus SNP or GSNO additively increased heme oxygenase-1 mRNA expression, whereas synergistic induction was seen with SNP plus GSNO. The SNP-mediated induction was not affected noticeably by extracellular superoxide dismutase, catalase, or mannitol, while the induction by SIN-1 was attenuated by superoxide dismutase. Thus, the SNP-mediated induction of heme oxygenase-1 mRNA expression may be independent of reactive oxygen species, and the induction by SIN-1 is mediated partly by peroxynitrite, which is generated by immediate reaction of NO and superoxide anion. Transient transfection assays suggested that treatment with SNP, but not with GSNO or SIN-1, increased the expression of a reporter gene through a cis-acting element, including the cadmium-responsive element, of the human heme oxygenase-1 gene. These results suggest that SNP induces heme oxygenase-1 mRNA expression through a mechanism different from that for GSNO or SIN-1. We therefore propose that induction of heme oxygenase-1 represents a common cellular response in sensing the signals evoked by distinct NO donors.

Immunohistochemical analysis of platelet-derived growth factor-B expression in myocardial tissues in hypertrophic cardiomyopathy

Intimal and/or medial hyperplasia of intramyocardial small vessels is thought to be one of the causes of myocardial ischemia in hypertrophic cardiomyopathy (HCM). However, the pathogenesis of such vascular lesions in HCM is not yet known. To evaluate the pathogenic role of platelet-derived growth factor (PDGF-B) and basic fibroblast growth factor (b-FGF), which have a potential to induce cellular and molecular changes observed in the vessels in HCM, we examined the expression of these molecules and PDGF receptors in cardiac tissues from six patients with HCM and seven controls using immunohistochemistry. The percentage of PDGF-B positive cells in the myocyte population in HCM was significantly higher than that in controls (52.6 +/- 16.2 (mean +/- SD) vs. 21.6 +/- 9.6, p < 0.01). PDGF-B was also observed in vascular regions in HCM (61.1 +/- 25.5% of arterioles) but not in controls. There were no significant differences in the expression of b-FGF and PDGF receptors in the myocyte and non-myocyte populations and the vascular regions between the HCM and control groups. Our study revealed that the expression of PDGF-B protein was up-regulated in HCM, suggesting the contribution of this molecule to the development of intramyocardial vasculopathy.

Suplatast tosilate inhibits late response and airway inflammation in sensitized guinea pigs

The effect of suplatast tosilate, which has been proven to inhibit T-cell synthesis of IL-4 and IL-5, on the response to antigen inhalation challenge was investigated in sensitized guinea pigs. The animals were given an oral dose of 30 or 100 mg/kg of suplatast or vehicle (distilled water) daily for 1 wk before antigen challenge. Measurement of pulmonary resistance for 6 h was followed by bronchoalveolar lavage and lung fixation. After antigen challenge, all guinea pigs in the vehicle group displayed dual-phase airway obstruction and accumulation of eosinophils and lymphocytes in the airways. After 1 wk of treatment with the high dose of suplatast, the late asthmatic response and the recruitment of eosinophils and lymphocytes into the airways were significantly inhibited, but the early asthmatic response was not affected. In situ hybridization revealed that challenge-induced increases in IL-5 mRNA-positive cells in lung tissue were significantly inhibited after treatment. Thus, suplatast inhibited airway obstruction in the late phase by specifically inhibiting the inflammatory process after mast cell degranulation.

Ovalbumin (OVA) and Mycobacterium tuberculosis bacilli cooperatively polarize anti-OVA T-helper (Th) cells toward a Th1-dominant phenotype and ameliorate murine tracheal eosinophilia

A recent increase in allergic disorders has coincided with a decrease in infections, including tuberculosis. Although an inverse association between tuberculin responses and atopic disorders was reported, it was not known how T-helper (Th)1-biased immune responses to Mycobacterium tuberculosis influenced Th2-dominant responses to allergens. We examined whether M. tuberculosis could modulate ovalbumin (OVA)-induced eosinophilic inflammation in the murine trachea in a manner that transcended the barrier of antigen specificity. We found that CD4(+) T cells primed with OVA in complete Freund's adjuvant (CFA) inhibited OVA-induced tracheal eosinophilia through interferon (IFN)-gamma secretion. Immunization with an irrelevant antigen in CFA or with OVA in incomplete Freund's adjuvant failed to induce suppressor cells. In vitro experiments confirmed that both M. tuberculosis and OVA (as opposed to either one alone) were necessary to evoke polarized development toward a Th1-like phenotype through interleukin-12 secretion. These results indicate that exposure to an allergen along with M. tuberculosis switches development of allergen-specific T cells toward a Th1 phenotype, which, in turn, downregulates allergic manifestations in an antigen-specific manner. The possible implications of these results are discussed in the context of the causal relationship between a decrease in tuberculosis and an increase in allergic disorders.

[Comparison of CRH test and ACTH test in patients with bronchial asthma]

Although glucocorticoid is the most effective agent for bronchial asthma, its systemic administration leads to suppression of adrenocortical function. Rapid ACTH test has been performed for assessing the function of the hypothalamic-pituitary-adrenocortical (HPA) system of asthmatics. Recently human corticotropin-releasing hormone (CRH) has been chemically synthesized. In order to evaluate clinical usefulness of CRH, we compared CRH test with ACTH test in 17 patients with bronchial asthma (3 patients out of them concurrently receiving prednisolone 5-10 mg/day). Both tests were carried out within 2 weeks after 6 month treatment with fluticasone propionate (800 micrograms/day) inhaled via pMDI. There is no significant difference between results obtained from the both tests. Thus, dividing subjects into high and low responders based on an extent of increases in plasma ACTH levels after the CRH injection, we found a significant difference in maximal plasma concentrations of cortisol between after CRH and ACTH injections in the low responders. Therefore, in some patients, CRH test provides more accurate assessment of the function of HPA system than ACTH test.

Cholinomimetic action of macrolide antibiotics on airway gland electrolyte secretion

We investigated the acute effects of erythromycin (EM) and its derivatives on ionic currents in airway glands from feline tracheae. Therapeutic concentrations of EM or clarithromycin (CAM) attenuated the whole cell currents evoked by ACh in a competitive manner. The maximally stimulated inward Cl- currents were reduced to 54 and 83% and the outward K+ currents to 55 and 84% of control values by EM and CAM, respectively, whereas the responses induced by phenylephrine, norepinephrine, caffeine, or ionomycin were unaffected by EM, CAM, or EM523, a synthetic derivative of EM. K+ channels in excised outside-out patches were not influenced by macrolides. Although therapeutic concentrations of macrolides showed no effect on the baseline currents, high concentrations of macrolides alone evoked currents mimicking the ACh response, which were abolished completely by atropine. We concluded that macrolides act as a partial agonist on cholinergic receptors, resulting in a reduction of Cl- secretion at pharmacological doses of the agents, which may exhibit a pronounced effectiveness on hypertrophied and/or cholinergically sensitized submucosal glands in pathological airways.

Incidence of pulmonary thromboembolism in Japan

Pulmonary thromboembolism (PTE) is considered an uncommon disease in Japan and there are not any reported prospective studies on the incidence of PTE in Japan. The objective of the present study was to determine the number of patients with PTE per year in a prospective study using a questionnaire. Letters were sent to clinical departments in university schools of medicine or medical colleges, and to hospitals with more than 100 beds. The diagnosis of PTE was to be confirmed by (1) pulmonary artery stenosis or occlusion on pulmonary angiography, (2) mismatch of pulmonary perfusion scintigraphy and pulmonary ventilation scintigraphy, (3) changes on pulmonary perfusion scintigraphy performed twice, or (4) autopsy. The questionnaire elicited 2,341 replies (the withdrawal rate was 40.7%). In 231 hospitals, 237 patients were diagnosed definitely during the study period of 2 months from 1 August to 30 September 1996. From this it was estimated that there are 3,492 (95% confidence interval: 3,280-3,703) patients with PTE per year, which implies that the incidence is 28 persons per 1,000,000 people per year, confirming that PTE is rare in Japan.

The role of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 genotypes in alcohol-induced vasospastic angina

Alcohol ingestion often provokes attacks in patients with vasospastic angina. Type 2 aldehyde dehydrogenase (ALDH2) deficiency, which is based on a single point mutation (Glu487Lys) of the ALDH2 gene, is common in the Japanese population, but rare among the Caucasian population. We investigated how the genotype of ALDH2 affects the characteristics of alcohol-induced vasospastic angina. Ninety-one patients with vasospastic angina who had ingested alcohol daily or occasionally were studied. Patients had been diagnosed as vasospastic angina by a provocation test with an intracoronary injection of ergonovine or acetylcholine during coronary angiography. The Glu487Lys mutation was detected by allele specific PCR. We interviewed the patients to obtain information concerning the relationship between alcohol ingestion and anginal attacks. Alcohol ingestion induced attacks in 16 of 66 patients without the Glu487Lys mutation, 8 of 22 in heterozygotes, and 1 of 3 in mutant homozygotes. The intervals between alcohol ingestion and the onset of anginal attacks were shorter in homozygotes (0.17 hours) and heterozygotes (1.5+/-0.6 hours) for ALDH2*2 than in normal homozygotes for ALDH2*1 (5.4+/-0.6 hours). The amount of ethanol which induced attacks was significantly greater in normal homozygotes than in homozygotes (11 ml) and heterozygotes (42.5+/-7.1 ml) for ALDH2*2 (96.1+/-13.4 ml in normal patients). The frequency of anginal attacks induced by alcohol ingestion did not differ between ALDH deficient and normal homozygotes. In ALDH deficient patients, however, anginal attacks were induced by a smaller amount of alcohol immediately after its ingestion. Thus, the ALDH2 genotype modifies the characteristics of the anginal attacks as a co-factor for the induction of vasospastic angina after alcohol ingestion.

Inhibition of matrix metalloproteinases prevents allergen-induced airway inflammation in a murine model of asthma

Although matrix metalloproteinases (MMPs) have been reported to play crucial roles in the migration of inflammatory cells through basement membrane components in vitro, the role of MMPs in the in vivo accumulation of the cells to the site of inflammation in bronchial asthma is still obscure. In this study, we investigated the role of MMPs in the pathogenesis of bronchial asthma, using a murine model of allergic asthma. In this model, we observed the increase of the release of MMP-2 and MMP-9 in bronchoalveolar lavage fluids after Ag inhalation in the mice sensitized with OVA, which was accompanied by the infiltration of lymphocytes and eosinophils. Administration of tissue inhibitor of metalloproteinase-2 to airways inhibited the Ag-induced infiltration of lymphocytes and eosinophils to airway wall and lumen, reduced Ag-induced airway hyperresponsiveness, and increased the numbers of eosinophils and lymphocytes in peripheral blood. The inhibition of cellular infiltration to airway lumen was observed also with tissue inhibitor of metalloproteinase-1 and a synthetic matrix metalloproteinase inhibitor. These data suggest that MMPs, especially MMP-2 and MMP-9, are crucial for the infiltration of inflammatory cells and the induction of airway hyperresponsiveness, which are pathophysiologic features of bronchial asthma, and further raise the possibility of the inhibition of MMPs as a therapeutic strategy of bronchial asthma.

Volume-pressure properties of the upper airway in normal subjects and patients with obstructive sleep apnoea

The aim of this study was to examine the volume-pressure (V-P) characteristics of isolated upper airways in normal subjects and patients with obstructive sleep apnoea (OSA) and to ascertain whether an increase in upper airway muscle activity affects these characteristics. We studied upper airway pressure changes during volume changes by inflation and deflation of air volumes of 5, 10, 15 and 20 mL without and with submental electrical stimulation, during voluntary closing of the glottis, in seven normal subjects and 13 OSA patients. Volume-pressure properties of the upper airway were assessed by elastance (Euaw) which was obtained from the slope of the regression line of the V-P relationships. Euaw in OSA patients was 0.52 +/- 0.08 cmH2O/mL, which was greater than in normal subjects (0.26 +/- 0.06 cmH2O/mL). Submental stimulation increased Euaw in both OSA patients and normal subjects (0.70 +/- 0.11 cmH2O/mL and 0.41 +/- 0.11 cmH2O/mL, respectively). These results suggest that upper airways of OSA patients during wakefulness are less collapsible than those of normal subjects, and that, in both groups, submental stimulation may stiffen the upper airway.

Morphometric analysis of bronchial cartilage in chronic obstructive pulmonary disease and bronchial asthma

To clarify the changes in bronchial cartilage in diseased airways, we performed morphometric analysis of airways in autopsied lungs of 16 patients with chronic bronchitis (Group CB), pulmonary emphysema (Group PE), and bronchial asthma (Group BA), and in control patients without respiratory diseases (Group CN). Although degeneration of bronchial cartilage was clearly observed in airways from all groups except Group CN, the most extreme change was seen in Group CB. Increased perichondrial fibrosis was observed in both Groups CB and BA, and the more extreme change was seen in Group BA. Both the area proportions of degenerated cartilage (Deg%) and perichondrial fibrosis (Fib%) to total cartilage in bronchi (3 to 8 mm in diameter), cut vertically in the cross-section profile, were measured with a digitizing tablet coupled to a computer. No significant differences in the area proportion of cartilage to bronchial wall were observed among the four study groups. The Deg% values of Groups CB (mean: 15.4%), BA (mean: 12.9%), and PE (mean: 9.6%) were significantly higher than those of Group CN (mean: 1.0%) (p < 0.01 in each case). The Deg% values correlated significantly with the number of neutrophils in the bronchial walls (r = 0.63, p < 0. 01). Both Group CB (mean: 28.5%) and Group BA (mean: 33.6%) showed significantly higher values of Fib% than did Group CN (mean: 18.5%) (p < 0.01, each), and the value for Group PE (mean: 21.8%) was slightly increased (p < 0.05). The values of Fib% correlated significantly with the number of eosinophils in the bronchial walls (r = 0.51, p < 0.05), thickness of basement membrane (r = 0.77, p < 0.0002), bronchial gland area (r = 0.56, p < 0.02), and goblet-cell area (r = 0.55, p < 0.02). Further, the values of Deg% correlated significantly with those of Fib% (r = 0.64, p < 0.01). These findings indicate that airways in chronic obstructive pulmonary disease and bronchial asthma have both degenerative changes in the cartilage (chondrocytes) and increased perichondrial fibrosis, and that these alterations in bronchial cartilage may differ in chronic bronchitis and bronchial asthma.

Safety and Efficacy of the Neuraminidase Inhibitor Zanamivir in Treating Influenza Virus Infection in Adults: Results from Japan

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 influenzalike 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.

Induction of adrenomedullin by hypoxia in cultured human coronary artery endothelial cells

To explore the role of adrenomedullin (ADM) in pathophysiology of ischemic heart disease, we investigated the effects of hypoxia on the production and secretion of ADM in cultured human coronary artery endothelial cells. Treatment with hypoxia (5% CO2/94% N2/1% O2) for 6 and 12 h increased expression levels of ADM mRNA 2.2-fold and fivefold compared with the normoxia control, respectively. The levels of immunoreactive ADM in the media were increased by 12-h hypoxia about fivefold compared with the control (39.0+/-1.1 fmol/10(5) cells per 12 h under hypoxia and 7.9+/-0.4 fmol/10(5) cells per 12 h under normoxia; P<0.01, n = 4, mean +/- SEM). Reverse-phase high-performance liquid chromatography of the extracts of culture media under normoxia and hypoxia showed one major peak eluting in the position of human ADM standard. The production and secretion of ADM were increased in cultured human coronary artery endothelial cells under hypoxia. ADM may therefore play an important pathophysiological role in ischemic heart disease.

Production and secretion of adrenomedullin in cultured human alveolar macrophages

To explore the role of adrenomedullin (ADM) in macrophages, we investigated the secretion of ADM by alveolar macrophages. Human alveolar macrophages obtained from bronchoalveolar lavage were cultured for 24 h. Northern blot analysis revealed ADM mRNA expression in alveolar macrophages. The levels of immunoreactive ADM in the media were 0.89+/-0.12 fmol/10(5) cells/24 h (n = 10). Reverse-phase high-performance liquid chromatography of the extract of culture media showed one major peak eluting in the position of the human ADM standard. The present study shows that alveolar macrophages produce and secrete ADM.