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Biomedical subjects

R Amitani

Publications and source records attributed to R Amitani.

At least 19 recordsLinked to original sources
PubMed2001

Effect of oestrogen on Mycobacterium avium complex pulmonary infection in mice.

The purpose of the present study was to elucidate the role of oestrogen in the pathogenesis of Mycobacterium avium complex (MAC) pulmonary disease, which occurs most frequently in postmenopausal women. The study was carried out in a murine infectious model using ovariectomized DBA/2 female mice. Infection with MAC was established by intratracheal administration of bacilli. In some experiments, ovariectomized mice were treated with exogenous 17 beta-estradiol (E2). The number of bacilli in the lungs of infected mice which received ovariectomy was significantly larger than that in the lungs of sham-operated control mice, and treatment of ovariectomized mice with exogenous E2 restored the burden of bacilli to the same level as that in the sham-operated control mice. We next examined the effect of E2 in vitro using bone marrow-derived macrophages obtained from DBA/2 female mice. The macrophages showed bacteriostatic activity against MAC after treatment with interferon-gamma (IFN-gamma) and this activity was further enhanced by the exogenous addition of E2 to the culture medium. In parallel with these findings, E2 augmented the production of reactive nitrogen intermediates (RNI) by macrophages pretreated with IFN-gamma and stimulated with MAC, as shown by evaluating nitrite production and inducible nitric oxide synthase mRNA expression. These findings taken together suggest that absence of endogenous oestrogen appears to be responsible for the development of MAC pulmonary disease in this mouse model and that the enhancement by E2 of anti-MAC activity of murine macrophages induced through increased RNI production may play some role in resistance to MAC infection.

Animals↗
PubMed2001

[Clinical comparison of Chlamydia pneumoniae pneumonia, ornithosis, and Mycoplasma pneumoniae pneumonia].

To elucidate the differences between the clinical aspects of Chlamydia pneumoniae (C. pn) pneumonia and those of two other atypical pneumonias, Chlamydia psittaci (C. ps) pneumonia and Mycoplasma pneumoniae (M. pn) pneumonia, we analyzed the symptoms and laboratory data on the cases of these three types of pneumonia: 46 cases of C. pn pneumonia, 39 cases of C. ps pneumonia, and 131 cases of M. pn pneumonia. C. pn pneumonia was significantly more frequent among the elderly (mean 70 +/- 16 years, p < 0.01) and patients were significantly more likely to be male (76%, p < 0.05). A white blood cell count of over 10,000 was seen in 46% of C. pn pneumonia cases, a higher proportion than those of C. ps pneumonia (15%, p = 0.03) or M. pn pneumonia (18%, p = 0.006) cases. The proportions of patients with these infections who had an elevated GOT or GPT were not significantly different. Maximum body temperature was higher in M. pn pneumonia than in C. pn pneumonia (p = 0.003). Purulent sputa were seen in 44% of C. pn pneumonia cases and 50% of M. pn pneumonia cases, and these rates were higher than that of 13% in C. ps pneumonia cases (p = 0.002, p = 0.004). Dyspnea and anorexia symptoms were the most frequent in C. pn pneumonia cases (24% and 29%, respectively, the highest of all three pneumonias). There were clinical differences between C. pn pneumonia and the other two atypical pneumonias. However, there was some difficulty in differentiating between C. pn pneumonia and typical bacterial pneumonia because mixed infections were common (24%) in C. pn pneumonia cases.

Adult↗
PubMed2000

Airway remodelling in cough-variant asthma.

Subepithelial-layer thickening, a pathological feature of airway remodelling, is present in cough-variant asthma. In bronchial biopsy samples we found mean subepithelial-layer thickness was 7.1 (SE 0.4) microm in patients with cough-variant asthma, 8.6 (0.4) microm in patients with classic asthma with wheezing, and 5.0 (0.2) microm in healthy controls. Thickness was significantly higher in patients with asthma than in controls, and was significantly greater in those with classic asthma than in those with cough-variant asthma. Early anti-inflammatory treatment might, therefore, be beneficial in cough-variant asthma, as recommended in classic asthma.

Adult↗
PubMed2000

Effect of proton pump inhibitor alone or in combination with clarithromycin on mycobacterial growth in human alveolar macrophages.

The effect of omeprazole, a clinically used proton pump inhibitor, alone or in combination with clarithromycin was evaluated against Mycobacterium avium, Mycobacterium intracellulare and Mycobacterium tuberculosis, using a human alveolar macrophage model of infection. Omeprazole exhibited no significant effect on the growth of the two M. avium complex strains or on the mycobactericidal activity of clarithromycin against them. In contrast, omeprazole significantly promoted the growth of Mycobacterium tuberculosis and the anti-mycobacterial activity of clarithromycin against it in human alveolar macrophages. It was speculated that intracellular acidic milieu around M. tuberculosis might be one reason for the lower activity of clarithromycin in the treatment of human tuberculosis.

Adult↗
PubMed2000

[Chest radiograph of atypical pneumonia: comparison among Chlamydia pneumoniae. Pneumonia, ornithosis, and Mycoplasma pneumoniae pneumonia].

No report has been found comparing Chlamydia pneumoniae (C. pneumoniae) pneumonia radiographically with other atypical pneumonias, Chlamydia psittaci (C. psittaci) pneumonia and Mycoplasma pneumoniae (M. pneumoniae) pneumonia. We described the chest radiographs of three kinds of pneumonia cases: 46 cases of C. pneumoniae pneumonia, 39 cases of C. psittaci pneumonia, and 131 cases of M. pneumoniae pneumonia. Radiographic shadows were categorized into main shadows and sub-shadows. The main shadows are classified from the viewpoint of the characteristics; air space consolidation(AS), ground-glass opacity(GG), reticular shadow(RS), bronchopneumonia(BP), and small nodular shadows (SN). The size, the site, and the number of the main shadows were also analyzed. In comparison among the three pneumonias, BP was the most frequent in M. pneumoniae pneumonia (0.40/case). AS predominated in C. pneumoniae pneumonia (0.67/case), and GG in C. psittaci pneumonia (0.62/case). The number of main shadows was equal, about 1.4/case in three pneumonias. Large shadows were less frequent in M. pneumoniae pneumonia than C. pneumoniae pneumonia (p = 0.02) and C. psittaci pneumonia (p = 0.01). Main shadows were more frequent in the outer zone in M. pneumoniae pneumonia than C. psittaci pneumonia (p = 0.01), and in the middle zone in C. psittaci pneumonia than in M. pneumoniae pneumonia (p = 0.02). Cases with bilateral main shadows were less common in M. pneumoniae pneumonia (9%) than C. pneumoniae pneumonia(33%, p = 0.001) and C. psittaci pneumonia(30%, p = 0.005). Thickening of bronchovascular bundles as a sub-shadow was most frequently noted in M. pneumoniae pneumonia. Some differences among the three atypical pneumonias were seen in the chest radiograph. However, no specific findings of C. pneumoniae pneumonia were shown radiographically in this study.

Aged↗
PubMed2000

Allergic granulomatous angiitis (Churg-Strauss syndrome) associated with allergic bronchopulmonary candidiasis.

We describe a case of Churg-Strauss syndrome (CSS) associated with allergic bronchopulmonary candidiasis (ABPC). A 61-year-old man who had been given a diagnosis of ABPC based on serologic and radiographic findings experienced pain and purpuric rash on the left leg accompanied with motor weakness. The diagnosis of CSS was made from skin, nerve and muscle biopsies. Although immunosuppressant and prednisolone were administered and resulted in transient improvement, candidal pneumonia was suspected to have developed 60 days after the administration and the patient finally died of respiratory failure. To our knowledge, this is the first case of CSS associated with ABPC.

Asthma↗
PubMed2000

Familial pulmonary Mycobacterium avium complex disease.

We report two Japanese families affected by pulmonary Mycobacterium avium complex (MAC) disease, involving an older brother and younger sister in one family and two brothers in the second family. We investigated whether defects in the natural resistance-associated macrophage protein gene (NRAMP1) underlay susceptibility to MAC in these cases. All of the patients had computed tomographic findings of peripheral nodules and bronchiectasis. Pulse-field gel electrophoresis patterns of mycobacterial genomic DNA restriction fragments revealed that none of the MAC strains isolated from the patients was epidemiologically related to any of the others. Direct sequencing of the complementary DNA of the patients' NRAMP1 revealed a nonconservative missense mutation at codon 419 in one patient, which was heterozygous and was not seen in his affected sibling. No variations similar to those found in mice that show susceptibility to MAC were found. The results suggest an underlying genetic defect in host defense rather than exposure to an unusually virulent strain of MAC as the pathogenetic factor in MAC disease; however, alterations in the coding region of NRAMP1 do not appear to explain the susceptibility to MAC.

Adult↗
PubMed2000

Airway wall thickness in asthma assessed by computed tomography. Relation to clinical indices.

Postmortem studies have shown that airway wall thickening is present in asthmatic patients and may play a pathophysiologic role. We investigated the presence and characteristics of airway wall thickening in patients with asthma, using helical computed tomography. Eighty-one asthmatic patients and 28 healthy control subjects were studied cross-sectionally. Airway wall thickness was assessed by a validated method on the basis of wall area (WA), WA corrected by body surface area (WA/BSA), and WA%, defined as (WA/total area) x 100 at the apical bronchus of the right upper lobe. Airway luminal area (Ai) and Ai/BSA were also examined. Asthma duration and severity, pulmonary function, and serum eosinophil cationic protein levels were evaluated. Intraobserver and interobserver reproducibility of WA, WA%, and Ai measurements were good. As compared with control, WA, WA/BSA, and WA% were significantly increased in patients with mild (n = 13), moderate (39), and severe persistent (22) asthma but not in patients with intermittent asthma (7). Comparison of the four asthmatic subgroups demonstrated thicker airways in more severe disease, but no difference in Ai or Ai/BSA. When all asthmatic patients were analyzed together, WA and WA/BSA correlated with the duration, although weakly, and severity of asthma. WA and WA/BSA negatively correlated with FEV(1) (percentage of predicted), FEV(1)/FVC (%), and FEF(25-75%) (percentage of predicted), whereas WA% negatively correlated with only FEV(1). We conclude that airway wall thickening occurs in patients with asthma and is not limited to those with severe disease. The degree of airway wall thickening may relate to the duration and severity of disease and the degree of airflow obstruction.

Adult↗
PubMed2000

Recurrent hemoptysis in tuberculosis with non-cavitary lung disease as a symptom of mild hemophilia A in a young adult.

Hemoptysis in patients with tuberculosis is usually associated with smear-positive and cavitary lung disease. The present case describes a patient suffering from recurrent hemoptysis associated with tuberculosis who had smear-negative and non-cavitary lung disease, and who was subsequently diagnosed as having mild hemophilia A. Although mild hemophilia A sometimes escapes detection until adolescence, there has been no reported case of mild hemophilia A detected by recurrent hemoptysis due to pulmonary tuberculosis. Here, we report a rare case of recurrent hemoptysis in a patient with tuberculosis who had smear-negative and non-cavitary lung disease and who was finally shown to have hemophilia A.

Adolescent↗
PubMed2000

[Empyema thoracis accompanied by hyperammonemic encephalopathy].

A 50-year-old man was admitted to our hospital due to consciousness disturbance. On admission, he was comatose (200 on the Japan Coma Scale) but brain computed tomographic (CT) scans were normal. Chest radiographs and CT scans on admission revealed massive pleural effusion in the right hemithorax. A culture of purulent pleural fluid yielded three species of anaerobes, including Bacteroides fragilis. Laboratory examinations revealed markedly elevated WBC count, CRP, and serum ammonia (586 micrograms/dl). However, liver function was almost normal and no other metabolic disorders were demonstrated. After the initiation of antibiotic therapy and pleural drainage, the patient's cousciousness level gradually improved in parallel with decreasing serum levels of ammonia and CRP. Because no other potential causes of hyperammonemia were observed, we concluded that the consciousness disturbance was due to hyperammonemia presumably caused by a urease-producing anaerobe infecting the right pleural space.

Ammonia↗
PubMed1999

Effect of clarithromycin regimen for Mycobacterium avium complex pulmonary disease.

We have investigated the efficacy of a clarithromycin-containing four-drug regimen for Mycobacterium avium complex (MAC) pulmonary disease in 46 patients without acquired immunodeficiency syndrome (AIDS). The patients were 14 males and 32 females with a mean age of 60.9 +/- 11.5 yr. Patients received 10 mg/kg/d of clarithromycin plus ethambutol, rifampin, and initial kanamycin and subsequent quinolone for 24 mo. Seven patients (15.2%) were dropped in the first 6 mo. Among 39 patients who received more than 6 mo of therapy, 28 patients (71.8%) converted their sputa to negative: 26 of 31 patients (83.9%) infected with clarithromycin-susceptible strains and two of eight patients (25.0%) with resistant or intermediate strains. The timing of sputum conversion was 3.6 +/- 1.9 mo, with a range of 2 to 9 mo. The conversion rate was significantly lower in patients who were infected with clarithromycin-resistant or intermediate strains, who had had prior therapy (55.0% versus 89.5%), or who were acid-fast bacilli (AFB) smear-positive at entry (60.7% versus 100%). The age and sex of patients, the species of pathogen (M. avium or M. intracellulare), type and extent of the disease, and the use of kanamycin did not significantly affect the conversion rate. Although the regimen was efficacious for newly treated patients, frequent adverse reactions and a low conversion rate of sputum in retreated patients are problems that remain to be solved.

Adult↗
PubMed1999

A pilot study of low-dose erythromycin in bronchiectasis.

Patients with bronchiectasis suffer from sputum production, recurrent exacerbations, and progressive airway destruction. Erythromycin is effective in diffuse panbronchiolitis, another suppurative airway disorder, although its efficacy is unknown in idiopathic bronchiectasis. A double-blind placebo-controlled study was therefore conducted to evaluate the effects of 8-week administration of low dose erythromycin (500 mg b.i.d.) in steady-state idiopathic bronchiectasis. Patients in the erythromycin group (n=11, 8 female, mean age 50+/-15 yrs), but not the placebo group (n=10, 8 female, mean age 59+/-16 yrs) had significantly improved forced expiratory volume in one second, forced vital capacity and 24-h sputum volume after 8 weeks (p<0.05). There was no parallel improvement in sputum pathogens, leukocytes, interleukin (IL)-1alpha and IL-8, tumour necrosis factor-alpha, or leukotriene B4. The results of this pilot study show that low-dose erythromycin improves lung function and sputum volume in bronchiectasis. Further studies are indicated to evaluate the efficacy of long-term erythromycin therapy in bronchiectasis.

Anti-Bacterial Agents↗
PubMed1999

[The need for new antituberculosis agents in Japan].

We discussed the need of new antituberculosis agents in Japan concerning drug adverse reactions in particular as well as drug interactions and drug resistance. We reviewed medical charts of hospitalized patients receiving standard antituberculosis chemotherapy (INH + RFP + EB/SM +/- PZA), and analyzed all symptoms, signs and abnormal laboratory data presumably caused by the chemotherapy. About 48% of 228 cases analyzed had at least 1 episode of adverse reactions: 77 episodes of hepatotoxicity, 15 episodes of ototoxicity, 14 episodes of eruption, 14 episodes of ocular toxicity and so on. About 23% cases treated with RFP, 20% cases with SM, 12% cases with INH and 7.7% cases with EB had at least 1 episode of adverse reactions due to the corresponding agent. In 59 cases, at least one agent was stopped to administer because of adverse reactions. Finally, standard chemotherapy could not be completed in 23% of all cases, and in stead, the other agents, mainly new quinolones, were administered. RFP induces cytochrome P450 3A in the liver to decrease the activities of many drugs, such as cyclosporin A, tacrolimus, protease inhibitor, itraconazole, and clarithromycin. In some clinical settings, RFP cannot be administered in combination with such drugs. In conclusions, new antituberculosis agents that have strong activities with less adverse reactions and drug interactions are needed in Japan, even without considering drug resistance.

Aged↗
PubMed1999

[A case of middle ear tuberculosis; PCR of the otorrhea was useful for the diagnosis].

A 26-year-old female was admitted to our hospital with complaints of fever, cough, otorrhea and otalgia and progressive hearing loss of her left ear. Smears of her sputum were positive for acid-fast bacilli. Smears of her otorrhea were negative for acid-fast bacilli but PCR of her otorrhea was positive. Chest X-ray showed infiltrative shadows with the cavity. She was diagnosed as middle ear tuberculosis associated with pulmonary tuberculosis. After anti-tuberculous chemotherapy, fever, cough, otorrhea and pain of her left ear were improved, but her hearing level was not improved. In the case of middle ear tuberculosis, it is necessary to make an early diagnosis and treatment. This is the first reported case in Japan in which PCR of the otorrhea is positive.

Adult↗
PubMed1998

Serum eosinophil cationic protein as a marker of eosinophilic inflammation in asthma.

BACKGROUND: The serum level of eosinophil cationic protein (ECP) has been used as a clinical marker in asthma, on the assumption that it reflects ongoing eosinophilic inflammation of the airways. However, only a few studies have investigated this issue, using bronchial secretions but not tissue specimens. OBJECTIVE: To evaluate cross-sectionally the correlation between serum ECP level or blood eosinophil count, and the degree of eosinophilia in bronchoalveolar lavage fluid (BALF) and bronchial biopsy tissue, and disease activity, in asthmatic patients. METHODS: Thirty-three adults with symptomatic asthma and six healthy controls were studied. The blood eosinophil count, ECP levels in serum and BALF, percentage of eosinophils in BALF, number of eosinophils in bronchial tissue, pulmonary function, and methacholine bronchial responsiveness of these subjects were clarified. An asthma severity score and inhaled beta2-agonist requirement (puffs/day) were also assessed for the asthmatic patients. RESULTS: The asthmatic patients, compared with the controls, had more obstructive (as tested by %FEV1, FEV1/FVC, and FEF25-75%) and more responsive airways, and showed a significant increase in the number of eosinophils in the blood, BALF, and tissue, and in the serum ECP levels. The ECP levels in BALF were below the detection limit for most of the subjects in both groups examined. In the asthmatic patients, serum ECP level demonstrated correlations with the number or percentage of eosinophils in BALF and tissue, whereas the blood eosinophil count correlated only with the percentage of eosinophils in BALF. Serum ECP level correlated with all indices of disease activity examined; %FEV1, FEV1/FVC, FEF25-75% bronchial responsiveness, severity score and beta2-agonist usage, whereas the blood eosinophil count correlated only with %FEV1 and bronchial responsiveness. CONCLUSION: The data suggest that serum ECP level reflects the intensity of eosinophilic airway inflammation, as well as the disease activity, and may be useful as an inflammatory marker in asthma.

Adult↗