Blood pressure and heart rate during periodic breathing while asleep at high altitude

The ventilatory and arterial blood pressure (ABP) responses to isocapnic hypoxia during wakefulness progressively increased in normal subjects staying 4 wk at 5,050 m (Insalaco G, Romano S, Salvaggio A, Braghiroli A, Lanfranchi P, Patruno V, Donner CF, and Bonsignore G; J Appl Physiol 80: 1724-1730, 1996). In the same subjects (n = 5, age 28-34 yr) and expedition, nocturnal polysomnography with ABP and heart rate (HR) recordings were obtained during the 1st and 4th week to study the cardiovascular effects of phasic (i.e., periodic breathing-dependent) vs. tonic (i. e., acclimatization-dependent) hypoxia during sleep. Both ABP and HR fluctuated during non-rapid eye movement sleep periodic breathing. None of the subjects exhibited an ABP increase during the ventilatory phases that correlated with the lowest arterial oxygen saturation of the preceding pauses. Despite attenuation of hypoxemia, ABP and HR behaviors during sleep in the 4th wk were similar to those in the 1st wk. Because ABP during periodic breathing in the ventilatory phase increased similarly to the ABP response to progressive hypoxia during wakefulness, ABP variations during ventilatory phases may reflect ABP responsiveness to peripheral chemoreflex sensitivity rather than the absolute value of hypoxemia, suggesting a major tonic effect of hypoxia on cardiorespiratory control at high altitude.

Glucocorticoid receptor alpha and beta in glucocorticoid dependent asthma

Patients with glucocorticoid (GC)-dependent asthma present an ongoing inflammation of the airways despite chronic long-term treatment with oral GC. Interleukin (IL)-8 and granulocyte/macrophage colony-stimulating factor (GM-CSF) have been implicated in airway inflammation in severe asthma and their synthesis is normally repressed by GC. To further characterize the inflammatory process in GC-dependent asthma, we measured the release of IL-8 and GM-CSF by peripheral blood mononuclear cells (PBMC) of eight normal subjects, six untreated controlled asthmatics, six untreated uncontrolled asthmatics, and nine GC-dependent asthmatics. We show that PBMC from GC-dependent asthmatics released high amounts of these cytokines despite chronic in vivo exposure to GC (p < 0.001 versus normal subjects). In contrast, when untreated uncontrolled asthmatics were given a short course of oral GC, IL-8 and GM-CSF production was inhibited (p = 0.0078). Release of IL-8 and GM-CSF by PBMC of GC-dependent asthmatics was reduced after in vitro GC treatment (p < 0.002). We investigated whether the incapacity of GC to inhibit production of these cytokines in vivo was the result of a dysregulation of the glucocorticoid receptor (GR) in GC-dependent asthma. GRalpha and GRbeta are, respectively, the functional receptor and a putative dominant negative form of the receptor. Western blot and polymerase chain reaction (PCR) analyses indicated that GRalpha was expressed at similar level in all groups and was largely predominant over GRbeta. Thus, persistent release of IL-8 and GM-CSF in GC-dependent asthma is not associated with low expression of GRalpha or overexpression of GRbeta.

15-Lipoxygenase expression and 15(S)-hydroxyeicoisatetraenoic acid release and reincorporation in induced sputum of asthmatic subjects

BACKGROUND

Recent evidence shows that 15(S)-hydroxy-eicoisatetraenoic acid (15[S]-HETE) can be released and rapidly reincorporated into cellular lipids. These mechanisms exert several immunoregulatory functions that may be relevant in airway inflammation.

OBJECTIVE

Our purpose was to evaluate the levels of both soluble and cell-associated 15(S)-HETE and to examine 15-lipoxygenase (15-LO) messenger RNA (mRNA) expression in sputum samples obtained from 10 control and 18 asthmatic subjects.

METHODS

Levels of 15(S)-HETE were measured by reverse-phase HPLC separation followed by RIA in supernatants and in cell membrane-extracted phospholipids after acid hydrolysis. 15-LO mRNA was evaluated by primed in situ hybridization (PRINS). Combined immunocytochemistry and PRINS was used to identify the phenotype of cells bearing 15-LO transcripts.

RESULTS

Levels of both soluble and cell-associated 15(S)-HETE were higher in asthmatic than in control subjects (P <.0001). The percentage of cells expressing 15-LO mRNA was higher in asthmatic than in control subjects (P <.01). On double staining for specific cell-type markers and 15-LO mRNA, macrophages were the major source for 15-LO.

CONCLUSION

This study shows that the induced sputum technique allows the evaluation of 15-LO activity and that soluble, cell-associated 15(S)-HETE and 15-LO levels are higher in asthmatic than in control subjects. In addition, this study indicates that, in induced sputum, airway macrophages are the major source of 15(S)-HETE in asthma.

Structural consequences of airway inflammation in asthma

Asthma represents a chronic inflammatory process of the airways followed by healing, the end-result of which is an altered structure referred to as a remodeling of the airways. Repair usually involves 2 distinct processes: regeneration (which is the replacement of injured tissue by parenchymal cells of the same type) and replacement by connective tissue and its eventual maturation into scar tissue. In many instances both processes contribute to the healing response and inflammation. In asthma the processes of cell dedifferentiation, migration, differentiation, and maturation and connective tissue deposition can be followed either by complete or altered restitution of airway structure and function, the latter often seen as fibrosis and increase in smooth muscle and mucus gland mass. These features result in an increased resistance to airflow, particularly when there is bronchial contraction and bronchial hyperresponsiveness. The effect on airflow is compounded by the presence of increased mucous secretion and inflammatory exudate, which not only blocks the airway passages but also causes an increased surface tension that favors airway closure.

c-erbB-2 and episialin challenge host immune response by HLA class I expression in human non-small-cell lung cancer

The role of major histocompatibility complex expression in cancer prognosis and pathogenesis is contradictory. The aim of the current study was to compare the expression of HLA class I molecules and of oncoproteins that may be sources of peptides presented by HLA class I antigens in non-small-cell lung cancer. For this purpose, the expression of HLA class I antigen and TAP-1 molecule (a transporter in the antigen-processing 1 transport protein) were studied with epidermal growth factor, receptor; c-erbB-2; episialin; wild-type and mutant p53; bcl-2 oncoprotein expression; and angiogenic factor expression (vascular endothelial growth factor and thymidine phosphorylase). The degree of lymphocytic stromal infiltration and of platelet-endothelial cell adhesion molecule-expressing lymphocytes was also studied. A strong association of c-erbB-2 and MUC1 (episialin) expression with HLA class I expression was observed (p = 0.005 and 0.009, respectively). Intense CD31-positive lymphocytic infiltration was also more frequent in HLA class I-positive cases (p = 0.05). Although there was no association of HLA class I expression with survival, loss of the HLA class I expression in MUC1 or c-erbB-2 overexpressing cases conferred a poorer clinical outcome (p = 0.04). Both c-erbB-2 and MUC1 are well-known targets of T-cell-mediated cytotoxicity and cell-cell or cell-matrix adhesion-regulating proteins. The authors provide evidence that the sequence of cell adhesion-disrupting oncoprotein expression, HLA class I induction, and enhanced epitope presentation followed by lymphocytic response is an important pathogenetic three-step sequence of events that define, in part, the clinical outcome in non-small-cell lung cancer.

Spontaneous gastroesophageal reflux and airway patency during the night in adult asthmatics

Controversies still exist on the role of nighttime gastroesophageal reflux (GER) in precipitating nocturnal asthma. We tested the relationship between GER and nocturnal bronchoconstriction by continuously and simultaneously monitoring both respiratory resistances and esophageal pH in seven asthmatics with moderate to severe GER disease. Twenty-nine GER episodes were found during the study night lasting more than 5 min (LGER) and 72 not longer than 5 min (SGER). Both long (LGER) and short (SGER) gastroesophageal refluxes were able to maintain significantly higher lower respiratory resistances (RLR) at the resolution of each GER episode (RLR(e)) with respect to baseline values. RLR, expressed as the area under the RLR curve along each GER episode (AUCR(LR)) and as RLR(e), showed significant correlations with GER duration. Moreover, a significant correlation was found between RLR measured 10 min after GER resolution and GER duration during each episode. We conclude that GER itself is able to elicit nocturnal bronchoconstriction in asthmatics with moderate to severe GER disease and that bronchoconstriction severity and duration are related to GER duration.

Myocardial ischemia during sleep

The role of sleep in the pathogenesis of coronary ischaemic events such as myocardial infarction, transient myocardial ischaemia, or cardiac sudden death, is unclear. This review will analyse the available data on the subject according to: (i) the autonomic and cardiovascular changes during sleep that may potentially favour myocardial ischaemia; (ii) the evidence of a circadian distribution of coronary events; and (iii) the factors possibly involved in the pathogenesis of nocturnal angina. Available data suggest that myocardial ischaemia may occur by different mechanisms in non-rapid eye movement (NREM) (decreased coronary perfusion pressure) and rapid eye movement (REM) sleep (increased myocardial oxygen demand). Coronary events show a major peak of occurrence between 6.00 a.m. and noon; however, the myocardial ischaemic threshold, defined as the heart rate value at which myocardial ischaemia develops, may be lower at night than during the daytime, suggesting an unexpectedly higher susceptibility to myocardial ischaemia during sleep than during wakefulness. These data warrant further study on the pathophysiology of coronary circulation during sleep. Finally, some evidence is available that sleep disordered breathing may precipitate nocturnal angina especially in REM sleep, through decreased arterial oxygen content secondary to hypoventilation or true apnoeas. More data are needed to better understand the effects of sleep on the coronary circulation, and to improve the therapeutic approach of nocturnal angina.

The expression of basic fibroblast growth factor (bFGF) in tumor-associated stromal cells and vessels is inversely correlated with non-small cell lung cancer progression

Tumor progression results from complex interactions between tumor and tumor-associated host tissue. Basic fibroblast growth factor (bFGF), via activation of its receptor, FGFR-1, has been postulated to be an important inducer of host stromal response and angiogenesis. To assess the putative role of tumor-associated stromal cells and vessels in tumor progression, we studied non-small cell lung cancer (NSCLC) from 84 patients, including 51 squamous cell carcinomas and 33 nonsquamous cell carcinomas, by immunohistochemical detection. bFGF and FGFR-1 immunoreactivity was observed in tumor and in tumor-associated stromal cells and vessels. The expression of bFGF and FGFR-1 in stromal cells was higher in squamous than in non-squamous cell carcinomas (respectively, P = .007 and P = .0004). We found that bFGF and FGFR-1 expression in tumor and tumor-associated stromal cells and vessels was directly correlated with host stromal response, as assessed by intratumoral extension of stroma, but not with angiogenic response, as assessed by microvessel count. Although FGFR-1 expression of tumor cells was directly correlated with T-stage (P = .03), bFGF expressions of tumor-associated stromal cells and vessels were inversely correlated with lymph node metastasis (respectively, P = .0001 and P = .0002) and advanced pathological stage (respectively, P = .03 and P = .01). These findings suggest that bFGF might mediate host stromal response in NSCLC and that the expression of bFGF in tumor-associated stromal cells and vessels might have an inhibitory role in NSCLC progression.

Respiratory energetics during exercise at high altitude

The purpose of this study was to assess the effect of high altitude (HA) on work of breathing and external work capacity. On the basis of simultaneous records of esophageal pressure and lung volume, the mechanical power of breathing (Wrs) was measured in four normal subjects during exercise at sea level (SL) and after a 1-mo sojourn at 5,050 m. Maximal exercise ventilation (VEmax) and maximal Wrs were higher at HA than at SL (mean 185 vs. 101 l/min and 129 vs. 40 cal/min, respectively), whereas maximal O2 uptake averaged 2.07 and 3.03 l/min, respectively. In three subjects, the relationship of Wrs to minute ventilation (VE) was the same at SL and HA, whereas, in one individual, Wrs for any given VE was consistently lower at HA. Assuming a mechanical efficiency (E) of 5%, the O2 cost of breathing at HA and SL should amount to 26 and 5.5% of maximal O2 uptake, whereas for E of 20% the corresponding values were 6.5 and 1.4%, respectively. Thus, at HA, Wrs may substantially limit external work unless E is high. Although at SL VEmax did not exceed the critical VE, at which any increase in VE is not useful in terms of body energetics even for E of 5%, at HA VEmax exceeded critical VE even for E of 20%.

Interleukin-8 induces lymphocyte chemotaxis into the pleural space. Role of pleural macrophages

The pleural space is a potential compartment between the lung and chest wall that becomes filled with fluid and inflammatory cells in a number of respiratory diseases. In an attempt to understand one aspect of the inflammatory process in the pleural space, we compared the responses in three different diseases (congestive heart failure [CHF], tuberculosis [TB], and cancer). Large concentrations of interleukin-8 (IL-8) were detected in cancer and TB effusions, but not in CHF. Surprisingly, the concentration of IL-8 correlated best with lymphocyte recruitment and not with neutrophil recruitment. Pleural fluid from cancer and TB patients was chemotactic for lymphocytes, and this activity was partly blocked by an anti-IL-8 antibody in cancer and completely blocked in TB. To determine whether there was the potential for a chemotactic gradient into the pleural space, pleural effusion cells were analyzed for the expression of IL-8. Cells in the effusions of cancer patients expressed IL-8, whereas IL-8 could not be detected from the cells of TB and CHF effusions. To explore the possible role of pleural macrophages in the regulation of IL-8, pleural effusion cells were treated with culture supernatants from stimulated pleural macrophages. Stimulated pleural macrophages were able to induce expression of messenger RNA (mRNA) for IL-8 and IL-8 protein production, and this activity was abrogated by blocking tumor necrosis factor-alpha. These findings suggest that soluble IL-8 is an important factor for the recruitment of lymphocytes into the pleural space, and that this cytokine is produced by both pleural structural and cancer cells after their activation by macrophage-derived, cytokine-mediated signals.

Evaluation of apoptosis of eosinophils, macrophages, and T lymphocytes in mucosal biopsy specimens of patients with asthma and chronic bronchitis

BACKGROUND

Apoptosis regulates inflammatory cell survival, and its reduction contributes to the chronicity of an inflammatory process. Apoptosis is controlled by suppressing or inducing genes, such as bcl-2 and p53, respectively.

OBJECTIVE

We sought to assess apoptosis of eosinophils, macrophages, and T lymphocytes in bronchial biopsy specimens from asthmatic subjects and to examine its regulation by evaluating the expression of B-cell lymphoma leukemia-2 (Bcl-2) and P53 proteins. We also sought to explore the relationships between cell apoptosis and GM-CSF, a cytokine able to increase eosinophil and macrophage survival.

METHODS

Apoptosis in eosinophils, macrophages, and T lymphocytes was evaluated in bronchial biopsy specimens obtained from 30 asthmatic subjects, 26 subjects with chronic bronchitis, and 15 control subjects by combining the terminal deoxynucleotidyl transferase-mediated dNTP nick end-labeling technique and immunohistochemistry. The expression of P53, Bcl-2, and GM-CSF was studied through immunohistochemistry by using specific mAbs.

RESULTS

The number of apoptotic eosinophils and macrophages was lower in subjects with asthma than in those with chronic bronchitis (P <.007 and P <.001, respectively) and inversely correlated with the clinical severity of asthma (P <.001 and P <.002, respectively). Few T lymphocytes were apoptotic in all groups studied. In asthma GM-CSF+ cells correlated with the number of nonapoptotic eosinophils and macrophages (P =.0001) and with the severity of the disease (P <.003). In asthma Bcl-2+ cells were higher than in control subjects and subjects with chronic bronchitis (P <.002 and P <.015, respectively), they outnumbered P53+ cells, and they correlated with the number of T lymphocytes (P <.001) and with the severity of the disease (P <.003).

CONCLUSION

Airway inflammation in asthma is associated with an enhanced survival of different cell types caused by reduced apoptosis.

Comparison between nasal and bronchial inflammation in asthmatic and control subjects

Although asthma and rhinitis often coexist, it is still unknown whether they are characterized by a similar inflammatory profile. We studied eosinophilic infiltration, epithelial shedding and reticular basement membrane thickness in nasal and bronchial biopsies of six control subjects, 15 untreated allergic asthmatics with perennial rhinitis, and six corticosteroid-dependent (CSD) asthmatics. In nasal and bronchial biopsies, eosinophils were greater in untreated asthmatics than in control subjects and CSD asthmatics (p = 0.001). In untreated asthmatics, eosinophils were higher in bronchial than in nasal biopsies (p = 0.002). In nasal and bronchial biopsies, reticular basement membrane thickness was greater in untreated and CSD asthmatics than in control subjects (nasal: p < 0.008 and p < 0. 004; bronchial: p < 0.001 and p < 0.008). In untreated and CSD asthmatics, reticular basement membrane thickness was greater in bronchial than in nasal biopsies (p = 0.001; Wilcoxon's W test). Nasal epithelium was not shed in all the study groups. In untreated asthmatics, bronchial epithelium shedding was greater than in control subjects or CSD asthmatics (p < 0.005), and it was greater than nasal epithelium shedding (p < 0.006). This study has shown that, although concomitant, the extent of eosinophilic inflammation of reticular basement membrane thickness and of the epithelium shedding is greater in bronchial than in nasal mucosa of asthmatic patients with perennial rhinitis.

Interleukin-4 enhances 15-lipoxygenase activity and incorporation of 15(S)-HETE into cellular phospholipids in cultured pulmonary epithelial cells

15(S)-Hydroxyeicosatetraenoic acid (15[S]-HETE) is a 15-lipoxygenase (15-LO) metabolite that may play an important role in different pulmonary diseases. 15-HETE is synthesized by different epithelial cells and may be subsequently incorporated into cellular phospholipids. We studied the role of interleukin-4 (IL-4) on 15-LO activity and on 15(S)-HETE incorporation into cellular phospholipids by WI-26 pulmonary epithelial cells. 15-LO activity was evaluated by measuring 15(S)-HETE production, through combined reverse-phase-high-pressure liquid chromatography (RP-HPLC) separation and specific radioimmunoassay (RIA), after incubation with arachidonic acid (AA). We also studied 15-LO messenger RNA (mRNA) expression, using primed in situ (PRINS) labeling. IL-4 (10 ng/ml) markedly increased the percentage of 15-LO mRNA-bearing cells as well as 15-LO activity after 24, 48, and 72 h, with a maximal response at 48 h. Uptake and incorporation into cellular phospholipid was studied with [3H]15(S)-HETE, which showed that IL-4 was able to increase significantly 15(S)-HETE incorporation into WI-26 cells, with a maximal effect observed at 72 h. Cellular-lipid-associated [3H]15(S)-HETE, evaluated with RP-HPLC after base-catalyzed hydrolysis, increased concomitantly with disappearance of the radiolabel from the supernatant. Class separation of cellular lipids with normal-phase HPLC (NP-HPLC) showed that IL-4 increased [3H]15(S)- HETE incorporation mainly in the phosphatidylinositol (PI) fraction. The ability of IL-4 to promote 15-LO activity and incorporation into cellular phospholipids of human lung epithelial cells may be important in airway inflammation and in modulation of the potential autocrine function of 15(S)-HETE.

IL-4 and IgE-anti-IgE modulation of 15(S)-hydroxyeicosatetraenoic acid release by mononuclear phagocytes

BACKGROUND

IL-4 modulates the synthesis of IgE, the expression of CD23, and the release of 15(S)-hydroxyeicosatetraenoic (15[S]-HETE).

OBJECTIVE

We evaluated the release of 15(S)-HETE by IL-4-stimulated monocytes and verified whether the observed increase in 15(S)-HETE release after passive sensitization and anti-IgE challenge of IL-4-treated monocytes was secondary to an increased CD23 expression.

METHODS

Human monocytes were incubated for 24, 48, and 72 hours with IL-4 (10 ng/mL) with or without an IgE-anti-IgE stimulation. We evaluated CD23 expression by immunocytochemistry and 15(S)-HETE release by HPLC and RIA. To prove that the increase in 15(S)-HETE release was due to the effect of IL-4 on CD23, we performed experiments with an anti-CD23 blocking mAb.

RESULTS

CD23 expression and 15(S)-HETE release were significantly increased by IL-4, reaching a peak after 72 hours (P <.02). After passive sensitization with human IgE and anti-IgE challenge, IL-4-stimulated monocytes released higher amounts of 15(S)-HETE than IL-4-unstimulated monocytes (P <.02). Pretreatment with the anti-human B-cell CD23 MHM6 mAb caused a dose-dependent inhibition of 15(S)-HETE release.

CONCLUSIONS

This study shows that immunologic challenge of IL-4-treated, passively sensitized monocytes results in a CD23-dependent additional increase of 15(S)-HETE release, indicating the presence of a synergistic effect of IL-4 on CD23 expression and 15(S)-HETE production.

Phenotypic and functional characterization of normal rat pleural macrophages in comparison with autologous peritoneal and alveolar macrophages

Pleural mononuclear phagocytes (PleMP) were isolated from normal rats by pleural lavage and compared with autologous peritoneal (PerMP) and bronchoalveolar mononuclear phagocytes (BAMP) isolated by peritoneal and bronchoalveolar lavage, respectively. The phagocytic activity of PleMP, PerMP, and BAMP, evaluated by testing their ability to ingest latex beads, was lower for PleMP and PerMP than for BAMP. The phenotype of PleMP, PerMP, and BAMP was characterized by immunocytochemical staining with a panel of monoclonal antibodies (mAbs). As expected, PleMP, PerMP, and BAMP did not react with OX19, OX33, ED5, MOM/3F12/F2, and anticytokeratin mAbs, specific for T lymphocytes, B lymphocytes, dendritic cells, granulocytes, and epithelial/mesothelial cells, respectively. Moreover, PleMP and PerMP populations were highly enriched with OX6-, OX42-, ED7-, and ED8-positive MP, whereas BAMP population was enriched with ED1- and ED9-positive cells. To test the ability of PleMP, PerMP, and BAMP to function as accessory cells (AC), mitomycin C-treated MP were used as stimulatory cells in mixed leukocyte reaction experiments, using allogeneic T cells as responders. 3HdTR incorporation by T cells was assessed as an index of AC function. PleMP and PerMP were more potent AC than BAMP. Moreover, when cultured together with autologous pulmonary interstitial dendritic cells, PleMP and PerMP exerted a more potent ability to stimulate T-cell proliferation than did BAMP. To investigate the capacity of MP to function as bactericidal and fungicidal cells, we tested their ability to kill Escherichia coli and Cryptococcus neoformans, respectively. PleMP and PerMP were less potent bactericidal and fungicidal cells than BAMP. The results of this study demonstrate that PleMP isolated from normal rat pleural space are functionally and phenotypically different from BAMP but similar to PerMP, and suggest that these cells might play an important role in cell-mediated immune reactions in the pleural space.

What is the evidence that obstructive sleep apnoea is an important illness?

Obstructive sleep apnoea (OSA) is described by some authors as a potentially lethal disease and by others as an almost harmless condition. Excessive daytime sleepiness, neuropsychological dysfunction, altered quality of life, cardiovascular disease (systemic and pulmonary hypertension, cardiac arrhythmias, stroke and ischaemic heart disease) and increased mortality have been described as OSA complications. There is little argument that OSA may determine sleepiness, alter cognitive functions, and worsen quality of life, although with great interindividual variability: this should induce OSA to be considered an important illness per se, since sleepiness in OSA was shown to lead to important consequences, like road traffic accidents. Besides, OSA may interact with coexisting cardiac and respiratory disease and favour the appearance of heart and respiratory failure. Therefore, OSA is certainly also worth careful consideration as an important aggravating factor of other diseases. The evidence that obstructive sleep apnoea is an independent risk factor for cardiovascular complications other than owing to the recurrent transient blood pressure surges associated with apnoeas during sleep, and for an increased mortality is more conflicting. More studies are necessary to identify which characteristics of obstructive sleep apnoea may be considered important markers of its severity and as risk factors for different possible complications.

Sputum metalloproteinase-9/tissue inhibitor of metalloproteinase-1 ratio correlates with airflow obstruction in asthma and chronic bronchitis

Asthma and chronic bronchitis are inflammatory diseases with extracellular matrix (ECM) remodeling and collagen deposition. Collagen homeostasis is controlled by metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). We evaluated MMP and TIMP balance in induced sputum of 10 control, 31 untreated asthmatic, and 16 chronic bronchitic subjects. We first performed zymographic analysis to identify the profile of MMPs. Zymography revealed a similar MMPs profile in all populations studied and that MMP-9 was the major enzyme released. We then measured, using enzyme immunoassay, the concentrations of MMP-9 and of its inhibitor TIMP-1 and evaluated whether airflow limitation may be associated with an imbalance between these enzymes. MMP-9 and TIMP-1 concentrations were greater in sputum of patients with asthma and chronic bronchitis than in control subjects. The molar ratio between MMP-9 and TIMP-1 was lower in asthmatics and chronic bronchitics than in control subjects, and positively correlated with FEV1 values. In asthma, MMP-9 levels were significantly correlated with the number of macrophages and neutrophils. This study shows that airway inflammation in asthma and chronic bronchitis is associated with an imbalance between MMP-9 and TIMP-1 which may have a role in the pathogenesis of ECM remodeling and airflow obstruction.

Effect of age upon airway obstruction and reversibility in adult patients with asthma

OBJECTIVE

In a cross-sectional study we evaluated the effect of aging (separately from that of duration of disease) on airway obstruction and reversibility by comparing two groups of non-smoker patients with asthma.

METHODS

We compared two groups of patients: group A, which had 50 subjects (8 men and 42 women) aged 59.7+/-4.6 years (mean +/- SD), and group B, comprised of 51 subjects (19 men and 32 women) who were 35.7+/-7.4 years old. The groups were selected because of comparable baseline degree of obstruction (FEV1 % of predicted, 67.8+/-20.3 in group A; 73.0+/-19.6 in group B, NS) and duration of the disease (14.0+/-11.7 years vs 11.2+/-9.1, NS). Spirometric examination, with a bronchodilator test, was performed and subjects not reaching 85% of predicted were submitted to a 4-week course of inhaled steroids.

RESULTS

Although a higher number of subjects from group B responded to the acute bronchodilator test (p < 0.001), the maximum response achievable with treatment (steroid or bronchodilator) (deltaFEV1 expressed as the percent of predicted) was not statistically different between groups (12.0+/-17.5 vs 16.0+/-23.9). The mean FEV1 attainable after treatment (deltaFEV1%PT) was significantly lower in the older group (p = 0.0006). Within groups, the baseline FEV1% did not correlate with age; it was inversely correlated with the duration of the disease (p < 0.03 and p < 0.01, respectively). In both groups deltaFEV1 was inversely related with the baseline FEV1, whereas FEV1%PT was correlated with the duration of the disease, with a slope nearly doubled in group B (p < 0.001).

CONCLUSIONS

Both the process of aging and the prolonged exposure to disease effects are important factors in determining the functional characteristics of chronic asthma: In particular, aging is associated not only with a reduced acute responsiveness to bronchodilators, but also with a reduced slope of the duration-FEV1%PT relationship that suggests a slowing of the rate of loss of reversibility of uncertain biological meaning.

MUC1 (episialin) expression in non-small cell lung cancer is independent of EGFR and c-erbB-2 expression and correlates with poor survival in node positive patients

AIM

To examine tumour samples immunohistochemically for MUC1 (episialin), epidermal growth factor receptor (EGFR), and c-erbB-2, since the disruption of the cell-cell adhesion system by MUC1 and the c-erbB oncoprotein family is known to be important in the development of metastasis in human cancers.

METHODS

93 tumour samples from patients with early stage non-small cell lung cancer treated with surgery alone were examined for episialin, EGFR, and c-erbB-2.

RESULTS

Episialin depolarised expression did not correlate with any of the histopathological variables examined (T,N stage, grade, histology, Ki67 proliferation index). No correlation was observed between episialin and EGFR or c-erbB-2 expression. Survival analysis showed that episialin depolarised expression correlated with poor prognosis (p = 0.003), especially in squamous cell cases (p = 0.0003). Episialin expression defined a group of patients with poor prognosis in the node positive category (p = 0.003). In multivariate analysis episialin was the most significant independent prognostic factor (p = 0.007), followed by N stage (p = 0.04).

CONCLUSIONS

Depolarised expression of episialin is associated with poor outcome in early stage non-small cell lung cancer. Despite the similar activity on the cadherin cell-cell adhesion system, the expression of episialin and c-erbB oncoproteins is likely to be activated within different pathogenic pathways.

Effects of high-altitude periodic breathing on sleep and arterial oxyhaemoglobin saturation

This study aimed to investigate the effect of periodic breathing (PB) at high altitude on sleep structure and arterial oxygen saturation (Sa,O2). Five healthy subjects underwent polysomnographic studies at sea level, and during the first and the fourth week of sojourn at 5,050 m. Their breathing pattern, sleep architecture and Sa,O2 were analysed. PB was detected in the high-altitude studies during nonrapid eye movement (NREM) sleep and tended to increase from the first to the fourth week. Stages 3-4 were absent in four subjects at the first week, but only in one at the fourth week, irrespective of the amount of PB. The arousal index was 11.6+/-3.8 at sea level, 30.1+/-15.5 at the first week at altitude and 33.0+/-18.2 at the fourth week. At altitude, arousal index in NREM sleep was higher during PB than during regular breathing. In NREM sleep, the mean highest Sa,O2 levels in NREM epochs with PB were higher than in those with regular breathing by 2.8+/-1.7% at the first week and 2.9+/-1.5% at the fourth week (p<0.025). From the first to the fourth week, mean Sa,O2 increased significantly during wakefulness (5.6%), NREM (5.2% with regular breathing and 5.3% with PB) and rapid eye movement sleep (7.6%). The data demonstrate a slight role of periodic breathing in altering sleep architecture at high altitude and also show that periodic breathing induces only a minor improvement in arterial oxygen saturation during nonrapid eye movement sleep.