Gen Tazaki

Role of cholinergic neural transmission on airway resistance in the dog

The unique contractile profiles of bronchial smooth muscle (Kondo et al., 1995) and its neural control were investigated by comparing responses of the bronchus and trachea to acute hypercapnia, stimulation of vagus efferent fibers before and after intravenous atropine, and intravenous acetylcholine in decerebrated and paralyzed dogs. During acute hypercapnia, airway resistance represented by peak airway pressure (Pedley et al., 1970) significantly increased as well as tracheal tension (Ttr). During electric stimulation of the vagal efferent fibers, Ttr increased and was sustained throughout the simulation period while the peak airway pressure was not maintained at the peak level. The peak Ttr and the airway resistance (Raw) calculated from ventilatory flow and airway pressure increased with increases in intensity of electric stimulation. Ttr reached its maximal level at an intensity 16 times of the threshold (T), while Raw became maximal at 4T. Although both the Ttr-stimulus intensity and Raw-intensity curves were shifted to the right by administration of intravenous atropine, the Raw curve shifted more to the right than the Ttr curve with the same dose of atropine. When muscular muscarinic receptors were directly stimulated by intravenous acetylcholine, Ttr once increased and then decreased promptly while peak airway pressure remained at a high level for a few minutes. These findings suggested that the bronchus is more sensitive to vagal efferent stimulation and susceptible to competitive antagonist of actylcholine than the trachea. In conclusion, the contractile profiles of the fifth-order bronchus we have reported (Kondo et al., 1995) were reflected in airway resistance, and the neuromuscular junction may be the site of adaptation of bronchoconstrictor response to motor nerve adaptation.

Clinical factors associated with negative urinary antigen tests implemented for the diagnosis of community-acquired pneumococcal pneumonia in adult patients.

Objective: This study investigated clinical factors associated with negative urinary antigen tests (UAT) implemented for the diagnosis of pneumococcal community-acquired pneumonia (CAP) in adult patients. Subjects and Methods: We reviewed the medical records of 755 adult patients who completed the UAT in our hospital between 2009 and 2012. Of these, we evaluated 63 patients with bacteriologically confirmed definite pneumococcal CAP (33 were UAT-positive, and 30 were UAT-negative). Results: There was no significant difference between the UAT-positive and the UAT-negative patients regarding age, dehydration, respiratory failure, orientation, blood pressure (ADROP) score (the CAP severity score proposed by the Japanese Respiratory Society), gender, white blood cell counts, liver/kidney function tests, or urinalysis. However, serum C-reactive protein (CRP) concentrations were 31% lower in the UAT-negative patients than in the UAT-positive patients (p = 0.02). Furthermore, the prothrombin time-international normalized ratio was 50% higher in the UAT-negative patients than in the UAT-positive patients, although the difference did not reach statistical significance (p = 0.06). The prevalence of comorbidities was similar in both UAT-positive and UAT-negative patients. However, warfarin had been prescribed in 8 (27%) of the UAT-negative patients compared to only 1 (3%) of the UAT-positive patients (odds ratio = 11.6; p = 0.01). Conclusions: These results suggested that low serum CRP concentrations and the use of warfarin increased the possibility with which false-negative UAT results occurred in these patients with pneumococcal CAP.

Lung metastasis of transitional cell cancer of the urothelium, with fungus ball‑like shadows closely resembling aspergilloma: A case report and review of the literature

The present study reports the case of a 67-year-old female patient who was initially diagnosed with pulmonary aspergilloma. This diagnosis was based on a chest computed tomography (CT) scan showing a cavitary lesion of 3.5 cm in diameter, with fungus ball-like shadows inside, and an air crescent sign in the right upper lung. At 63 years old, the patient was treated for transitional cell cancer of the urothelium (non-invasive, pT1N0M0) by total cystectomy, ileal conduit diversion and urostomy. For 4 years post-operatively, the patient was healthy and had no clinical symptoms, and the air crescent sign was not identified by chest CT until the patient had reached 67 years of age. However, a final diagnosis of lung metastasis of transitional cell cancer of the urothelium was histopathologically identified subsequent to video-assisted thoracic surgery. Although it is rare that transitional cell cancer moves to the lung and makes a cavitary lesion, a differential diagnosis of cancer is necessary, even when examining infected patients with air crescent signs that are characteristic of aspergilloma. The physician must be mindful of metastatic pulmonary tumors that closely resemble aspergillomas, not only in infectious diseases, but also in oncological practice. Primary surgical removal should be considered.

Remission of ALK-negative primary pulmonary inflammatory myofibroblastic tumor on treatment with clarithromycin: A case report and review of the literature

Inflammatory myofibroblastic tumors (IMTs) belong to an intermediate group of soft-tissue tumors, they are relatively rare but exhibit a wide range of pathologies, from benign to malignant. At present, no standard treatment has been established, however, it is known to be important to determine the grade of malignancy of the tumor, prior to treatment. The present study reports a 73-year-old female patient with no clinical manifestations, who, when examined radiographically at a health check exhibited bilateral thoracic infiltrative shadows and nodular shadows by chest CT. A metastatic tumor or an organizing pneumonia were suspected. Blood examination showed no abnormal findings, and a pathological diagnosis of IMT was given from the histological findings of the tissue extracted by video-assisted thoracic surgery. Histological analysis established the lack of expression of anaplastic lymphoma kinase (ALK1) and immunoglobulin subtype G4 (IgG4). Alteration of the radiological shadows was observed over several weeks, and after concluding that chronic inflammation was worsening the patients condition, clarithromycin was administered as a long-term macrolide therapy. The IMT decreased in size, and eight months later it had almost resolved. The patient was last reported to be maintaining a stable condition with no relapse. Some IMT cases have malignant pathology, and should be carefully followed-up. However, in the present case, where the IMT is both ALK1-negative and IgG4-negative, its biological immune responsiveness appears to differ from positive cases, and an inflammatory response was predominant. Clarithromycin, has immunomodulatory and anti-inflammatory effects and appeared to be effective in treating the IMT of the patient in the present study.

Tracheobronchial Foreign Body Aspiration Demonstrating Serial Bronchopulmonary Changes on Computed Tomography

Introduction: Tracheobronchial foreign body may often be treated as asthma, chronic bronchitis or etc. especially in patients with no memories of aspiration episodes. Case Presentation: A 74-year-old woman, suffering from persistent cough, was temporarily misdiagnosed with allergic bronchopulmonary aspergillosis and treated for six months. During this period, computed tomography (CT) findings changed from thickened bronchial walls and a “tree-in-bud” pattern to clubbing bronchiectasis and atelectasis, and no significant bacteria was detected. Finally, a vegetable core was subsequently extracted via flexible bronchofiberscopy. Although the patients symptoms improved dramatically, the bronchopulmonary lesion remained practically. Conclusions: We assume that chronologic CT findings of the bronchopulmonary damage by aspiration of a vegetable core, without significant detection of bacteria during the course, will be quite valuable for clinicians.

Effect of the respiratory-related bronchial rhythmic constriction on alveolar ventilation in the dog.

The middle-sized bronchus constricts during mid-inspiration through early-expiration. The purpose of this study was to elucidate the physiological role of this respiratory-related bronchial rhythmic constriction (RRBRC). The following parameters were measured in 12 decerebrated and paralyzed dogs: pressure from a balloon-tipped catheter in the fifth-generation bronchus (to reveal RRBRC), efferent neurogram from C(5) phrenic, and ventilatory flow and volume. We found a small but significant reduction of peak expiratory flow of mechanical ventilation during RRBRC. During bilateral vagal cold block, RRBRC was simulated by intermittent electric stimulation of vagal fibers distal to the cold block. This stimulus evoked a decrease in peak expiratory flow and in Pa(CO2) (approximately 1.5 mmHg). After vagal warming, mechanical ventilation was terminated, and blood gases were maintained normal by extracorporeal oxygenation. During each RRBRC ventilatory volume decreased by approximately 3 ml. The changes in gas volume and RRBRC disappeared after bilateral vagotomy. These findings support the concept that the physiological role of RRBRC is to facilitate alveolar gas exchange by reducing expiratory flow, anatomical dead space, or both.