Inflamatory mechanisms in bronchial asthma and COPD

Kallikrein-related peptidases in lung diseases

Human tissue kallikreins (KLKs) are 15 members of the serine protease family and are present in various healthy human tissues including airway tissues. Multiple studies have revealed their crucial role in the pathophysiology of a number of chronic, infectious and tumour lung diseases. KLK1, 3 and 14 are involved in asthma pathogenesis, and KLK1 could be also associated with the exacerbation of this inflammatory disease caused by rhinovirus. KLK5 was demonstrated as an influenza virus activating protease in humans, and KLK1 and 12 could also be involved in the activation and spread of these viruses. KLKs are associated with lung cancer, with up- or downregulation of expression depending on the KLK, cancer subtype, stage of tumour and also the microenvironment. Functional studies showed that KLK12 is a potent pro-angiogenic factor. Moreover, KLK6 promotes malignant-cell proliferation and KLK13 invasiveness. In contrast, KLK8 and KLK10 reduce proliferation and invasion of malignant cells. Considering the involvement of KLKs in various physiological and pathological processes, KLKs appear to be potential biomarkers and therapeutic targets for lung diseases.

Helicobacter pylori infection: seroprevalence and predictors among healthy individuals in Al Madinah, Saudi Arabia

BACKGROUND

Helicobacter pylori infection is one of the most common chronic bacterial infections among humans worldwide. However, there is no information on the epidemiology of H. pylori infection in Al Madinah, Saudi Arabia.

OBJECTIVE

This study was conducted to determine the seroprevalence of H. pylori in asymptomatic healthy individuals and the possible relationship between H. pylori infection and sociodemographic, lifestyle, and environmental factors in this region.

METHODS

A hospital-based cross-sectional study was conducted on a consecutive sample of asymptomatic healthy individuals. A pilot-tested interview format was used as the research tool. Venous blood was collected from individuals and sera were separated. The enzyme-linked immunosorbent assay was used to determine H. pylori IgG antibody levels in all serum samples.

RESULTS

A total of 456 samples were collected. H. pylori antibodies were found in 129 (28.3%) individuals. Seroprevalence of 16.9% was found in individuals younger than 20 years of age, which gradually increased with age and reached 36.8% by the age of 50. After controlling for the confounding factors, significant independent predictors of seropositive state were: rural residence [odds ratio (OR)=2.5, 95% confidence interval (CI)=1.3, 4.7], crowded housing (OR=1.6, 95% CI=1.1, 2.6), low socioeconomic status (OR=3.3, 95% CI=1.6, 8.8), using tanks for drinking water supply (OR=2.2, 95% CI=1.2, 7.4), active smoking (OR=5.6, 95% CI=3.2, 9.8), alcohol drinking (OR=2.3, 95% CI=1.5, 6.2), eating raw vegetables (OR=3.2, 95% CI=1.4, 7.1), eating spicy food (OR=2.1, 95% CI=1.3, 3.5), and presence of asthmatic/atopic symptoms (OR=2.5, 95% CI=1.3, 5.9). No associations were found between infection and age, gender, source of sewage disposal, eating fruits, or family history of upper gastrointestinal symptoms.

CONCLUSION AND RECOMMENDATIONS

Infection with H. pylori is declining among healthy individuals of Al Madinah, Saudi Arabia. Infection is acquired at an early age and reaches up to 36.9% as age advances. The risk of H. pylori seropositivity was related to socioeconomic, lifestyle, and environmental factors. A nationwide epidemiological study is warranted to determine the seroprevalence of H. pylori in Saudi Arabia.

An in vitro cellular analysis of the radical scavenging efficacy of chitooligosaccharides

Despite extensive study on biological activities of chitosan and chitooligosaccharides (COS), there is no experimental evidence available as to COS mediated inhibition of free radical damage in cellular oxidizing systems. In this study, radical scavenging efficacies of different molecular weight bearing COS were assessed and their intracellular radical scavenging effects were tested employing B16F1, murine melanoma cell line. The results exhibited appreciable suppression in occurrence of intracellular radical species in the presence of low molecular weight bearing COS (<1 kDa) confirming low molecular weight is important for observed activities in biological systems. However, DNA oxidation carried out in the presence of COS clearly exhibited that COS exert protective effect on oxidative damage of purified genomic DNA regardless of molecular weight. Low molecular weight bearing COS was observed to be successively participated in suppression of NF-kappaB gene promoter activity suggesting its capability to prevent oxidative stress related disease complications. Moreover, induction of intracellular glutathione (GSH) level in the presence of COS promoted the effectiveness of COS to act against cellular oxidative stress.

High prevalence of gastroesophageal reflux disease with minimal mucosal change in asthmatic patients

It is known that the prevalence of gastroesophageal reflux disease (GERD) in asthmatic patients is high. Although an endoscopic diagnosis of GERD based on the established Los Angeles (LA) classification requires the detection of erosive mucosal breaks, there are patients with GERD who have prominent erythema of the esophageal membrane without erosive mucosal breaks. Non-erosive mucosal change denotes the minimal change of the discoloring type of reflux esophagitis. This study was undertaken to determine the prevalence of GERD in asthmatic patients using the LA classification with the inclusion of minimal change, compared to the prevalence determined using the established LA classification without minimal change. The presence of GERD in asthmatic patients (n = 78), non-asthmatic disease control patients (n = 56), and healthy subjects (n = 150) was evaluated by endoscopic examination. The frequency of GERD in asthmatic patients based on the LA classification with minimal change was higher (54/78, 69.2%) than in asthmatic patients based on the LA classification without minimal change (37/78, 47.4%) (p < 0.05). The prevalence of GERD in asthmatic patients (69.2%) was higher than that in disease control patients (17/56, 30.4%) and healthy subjects (27/150, 18.0%) based on the LA classification with minimum change. These data indicate that asthmatic patients have a high frequency of GERD. In addition, without the inclusion of minimum change to the diagnosis of GERD, the prevalence of GERD appears to be underestimated in asthmatic patients. Therefore, physicians should carefully observe asthmatic patients with minimal change on endoscopy.

Two cases of asthma in handicapped elderly persons in which assisted inhalation therapy was effective

BACKGROUND

Chronic airway inflammation is a basic pathology of bronchial asthma and it is important to control the inflammation by anti-inflammatory therapy mainly with steroids. However, in asthma in the elderly, there are cases where physicians hesitate to introduce the inhaled corticosteroid (ICS) therapy based on the diagnosis that the use of inhalants is difficult due to the existence of a functional lesion accompanying asthma.

METHODS & RESULTS

In cases where self-administrated inhalation therapy is difficult to execute due to the accompaniment of a functional lesion and in cases where sufficient curative effects of steroids are not produced in self-inhalation, administration of assisted inhalation resulted in improvement of clinical symptoms and pulmonary function and was proven effective.

CONCLUSIONS

Assisted inhalation therapy is expected to be useful in general and also in terms of expanding the application of ICS in the asthma in the elderly.

Mice with Blunted Hypoxic Ventilatory Response are Susceptible to Respiratory Disturbance during Hypoxia

Hypoxia causes a life-threatening situation, and the ventilatory response to hypoxia plays an important role in preventing death. We have hypothesized that persons with a blunted hypoxic ventilatory response may have a weak defense response to hypoxic episodes and be susceptible to fatal respiratory disturbances. However, precise correlations between the hypoxic ventilatory response and respiratory disturbances are not well understood. In the present study we examined the hypoxic and hypercapnic ventilatory responses in nine inbred mouse strains (A/J, AKR/N, BALB/c, C3H/He, C57BL/6, DBA/2, NZW, SWR/J, and 129Sv). Breathing frequency, tidal volume and minute ventilation of unanesthetized and unrestrained mice were assessed by whole body plethysmography. Age-matched mice were exposed for 3 min to 10% O(2) in N(2) gas or 10% CO(2) in hyperoxic gas to determine the acute ventilatory response to chemical stimuli. Basal respiratory variables and hypoxic ventilatory responses differed among the strains, but the hypercapnic ventilatory response did not differ. The hypoxic ventilatory response was the highest in AKR/N mice and the lowest in SWR/J mice. These findings suggest that genetic factors may have influenced the hypoxic ventilatory response but not the hypercapnic ventilatory response. To examine the effects of severe hypoxic stress on the respiratory cycle, we exposed the strain with the highest or lowest hypoxic ventilatory response to 6% O(2) in N(2) until the onset of apnea. The "appearance time of apnea", which is defined as the time from the hypoxic loading to the onset of apnea, was shorter in the SWR/J strain than in the AKR/N strain. We suggest that a lower hypoxic ventilatory response may be a risk factor for apnea under hypoxia.

Helicobacter pylori seroprevalence in patients with mild asthma

Helicobacter pylori (H. pylori) is causally related to chronic active gastritis, peptic ulcer disease, primary low-grade B-cell gastric lymphoma, and is also a risk factor for gastric cancer. In addition, a high seroprevalence of H. pylori has been found in many extragastrointestinal disorders, including active bronchiectasis and chronic obstructive pulmonary disease (COPD). It appears that H. pylori has a close relationship with respiratory diseases, but data in the literature on the relationship between H. pylori infection and asthma are poor. We therefore investigated the relationship between them. In this study we evaluated 46 patients with mild asthma, 48 age- and sex-matched patients with peptic ulcer and 48 healthy control subjects. All enrolled subjects underwent a serologic test for H. pylori IgG and cytotoxin-associated gene-A (CagA) by enzyme-linked immunosorbent assay (ELISA). There was no significant difference in both anti-H. pylori IgG seropositivity (p=0.6580) and anti-H. pylori-CagA IgG seropositivity (p=0.7183) between the asthmatic and control subjects. In contrast, both anti-H. pylori IgG seropositivity and anti-H. pylori-CagA IgG seropositivity were significantly higher in peptic ulcer patients than these in asthmatic patients (p<0.01). Despite the sero-epidemiological association of H. pylori infection with many inflammatory conditions, our data show no significant association between mild asthma and H. pylori infection.

Inflammatory mediators down-regulate 11beta-hydroxysteroid dehydrogenase type 2 in a human lung epithelial cell line BEAS-2B and the rat lung

In the lung, anti-inflammatory actions of glucocorticoids would be determined by 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2), the microsomal enzyme responsible for the breakdown of bio-active glucocorticoids. However, regulation of 11beta-HSD2 under inflammatory conditions such as acute lung injury is not well understood. In the present study, we examined whether inflammatory substances would influence the activity and mRNA expression of 11beta-HSD2 in the lung. In a human bronchial epithelial cell line BEAS-2B, endotoxin inhibited 11beta-HSD2 enzyme activity in a dose-dependent manner over 48 h with a significant decrease in the mRNA expression. Likewise, tumor necrosis factor (TNF)-alpha inhibited both activity and mRNA expression of 11beta-HSD2. The TNF-alpha-dependent decrease in the enzyme activity was completely blocked by anti-TNF-alpha antibody, while antibody alone showed no significant influence on the enzyme activity. An nitric oxide donor (NO) sodium nitropusside or a cGMP analog 8-br-cGMP caused moderate but significant decreases in both activity and mRNA expression of 11beta-HSD2. Importantly, treatment of rats with endotoxin significantly decreased both activity and mRNA expression of 11beta-HSD2 in the lung tissue. We conclude that lung inflammation reduces local glucocorticoid breakdown and augments glucocorticoid action in the lung by down-regulating 11beta-HSD2 via multiple mechanisms.

Impaired sympathetic skin response in chronic obstructive pulmonary disease

The sympathetic skin response (SSR) is considered as one of the indexes of autonomic nervous system functions, especially related with the sudomotor function of unmyelinated sympathetic fibers. SSRs are recorded as the potentials with biphasic or multiphasic waveforms by conventional electromyography. SSRs are evaluated by measuring latency (time from the stimulus to the onset), amplitude, and area (the space under the curve of the waveform). Although dysautonomia is a feature of chronic obstructive pulmonary disease (COPD), as demonstrated by acetylcholine sweat-spot test, there are no data concerning SSR in COPD patients. In this study, we electrophysiologically investigated the sudomotor function of the sympathetic nervous system in patients with COPD. SSRs were recorded in 30 patients with COPD and 21 healthy volunteers. Normal responses were obtained from all subjects in the control group. No response was observed in three patients with COPD. The mean latency, amplitude and area values of the potentials recorded of the remaining 27 patients were compared to the control. The mean latency was longer (p<0.01) and the mean amplitude and area values were lower (p=0.012, p=0.021, respectively) in the patients compared to the control. We also demonstrated significant correlations between the latency, amplitude, or area values of the SSR and two parameters of pulmonary function tests forced expiratory volume one second/forced vital capacity (FEV1/FVC) and FEV1/FVC %. In conclusion, SSR is impaired in patients with COPD, which indicates the dysfunction of the sympathetic nervous system. Furthermore, the degree of impairment in SSR may reflect the severity of airway obstruction in patients with COPD.

Prevalence of chronic obstructive pulmonary disease in Japanese people on medical check-up

In Japan, spirometry has not been included as an item in medical check-ups for all persons. The purpose of this study was to show evidence to recommend spirometry routinely on medical check-up for the early detection of chronic obstructive pulmonary disease (COPD). There were 12,760 enrolled persons who underwent medical check-up. COPD was defined as a ratio of forced expiratory volume in one second to slow vital capacity of 70% or less. We investigated the prevalence and its characteristics of COPD in people on medical check-up. The prevalence of COPD was 3.6% in all subjects, 4.5% in males, and 1.8% in females. In the comparison between males and females, the prevalence of COPD in males of most age groups was higher than that of females, and this difference was greater with aging. Males in their 50s and over 60 years old and females over 60 years old showed remarkably high prevalences. Occupations associated with a high smoking rate such as transportation-related occupations showed a higher prevalence of COPD. These results suggest that spirometry for all persons in medical check-ups can identify many COPD patients not aware of this disease. Spirometry should be carried out routinely on medical check-up.