Molecular characterization of GPR84 in domestic cats.

G protein-coupled receptor 84 (GPR84) was cloned as an orphan receptor, and medium-chain fatty acids were then revealed as endogenous ligands. GPR84 is expressed in immune cells and is believed to protect liver function from lipotoxicity caused by overeating and high-fat diet intake. This study aimed to present the molecular characterization of GPR84 in domestic cats. The deduced amino acid sequence of the feline GPR84 shows high sequence homology (83-89 %) with the orthologues from other mammalians by cDNA cloning of feline GPR84. Remarkably high mRNA expression was observed in the bone marrow by Q-PCR analysis. The inhibition of intracellular cAMP concentration was observed in cells transfected with feline GPR84 and treated with medium-chain fatty acids. Immunostaining of GPR84 and free fatty acid receptor 2 (FFAR2)/GPR43 in the bone marrow, where high mRNA expression was observed, showed reactions in macrophages and myeloid cells. To clarify whether the receptor formed homo/hetero-merization, GPR84 and FFARs were analyzed using Nano-Luc binary technology and NanoLuc bioluminescence resonance energy transfer technologies, which revealed that GPR84 formed more heteromers with FFAR2 than homomers with each other. In addition, when GPR84 and FFAR2/GPR43 were cotransfected in the cell, their localization on the cell membrane was reduced compared with that when single receptors were transfected. These results indicated that GPR84 is a functional receptor protein that is expressed in cat tissues and may have a protein-protein interaction with FFAR2/GPR43 on the cell membrane.

Repeated bronchoconstriction attenuates the cough response to bronchoconstriction in naïve guinea pigs.

BACKGROUND: Cough variant asthma (CVA) is recognized as a precursor of bronchial asthma (BA). However, the cough response to bronchoconstriction differs between these similar diseases. Repeated bronchoconstriction and the resulting imbalance of endogenous lipid mediators may impact the cough response. METHODS: We investigated the influence of repeated bronchoconstriction on the cough response to bronchoconstriction using naïve guinea pigs. Bronchoconstriction was induced for 3 consecutive days and changes in the cough response and lipid mediators, such as PGE2, PGI2, and cysteinyl-LTs (Cys-LTs), in BAL fluid (BALF) were assessed. We investigated the effect of endogenous PGI2 on the cough response by employing a PGI2 receptor antagonist. In order to investigate the cough response over a longer period, we re-evaluated the cough response 2 weeks after repeated bronchoconstriction. RESULTS: The number of coughs induced by bronchoconstriction were significantly decreased by repeated bronchoconstriction. The levels of PGE2, PGI2, and Cys-LTs, and the ratio of PGI2/PGE2 were significantly increased, following repeated bronchoconstriction. This decrease in the cough response was suppressed by pretreatment with a PGI2 receptor antagonist. Two weeks after repeated bronchoconstriction, the cough response returned to the same level as before repeated bronchoconstriction along with a concomitant return of lipid mediators, such as PGE2, PGI2, and Cys-LTs and the ratio of PGI2/PGE2. CONCLUSIONS: Our results suggest that repeated bronchoconstriction and the resulting imbalance of endogenous lipid mediators contribute to the difference in cough responses to bronchoconstriction in CVA and BA.

Role of prostaglandin E2 in bronchoconstriction-triggered cough response in guinea pigs.

A feature of cough variant asthma is a heightened cough response to bronchoconstriction. The mediators of this response are unknown. This study was designed to elucidate the role of lipid mediators in bronchoconstriction-triggered cough response in an experimental animal model. We examined the influence of bronchoconstriction on cell components and mediators including prostaglandin E2 (PGE2) in bronchoalveolar lavage fluid (BALF). We studied the cough response to bronchoconstriction (CRB) by measuring the correlation between the increase in enhanced pause (Penh), an index of bronchoconstriction, and cough counts induced by methacholine (Mch) inhalation in conscious guinea pigs. We then examined the effects of intraperitoneal pretreatment with 16, 16-dimethyl-prostaglandin E2 (dm-PGE2) on CRB and cough counts. The total number of cells and cell components in the BALF were not influenced by bronchoconstriction. While levels of PGE2, prostaglandin I2, and cysteinyl leukotrienes were significantly increased, levels of prostaglandin D2, thromboxane B2, and substance P in the BALF were not. Dm-PGE2 significantly decreased the Mch-induced increase in Penh. Following bronchoconstriction by additional Mch inhalation, dm-PGE2 produced an increase in CRB and cough counts in a dose-dependent manner. Additionally, the heightened CRB following dm-PGE2 treatment was suppressed by pretreatment with PGE2 receptor (E-prostanoid EP) -1 and EP-3 antagonists in a dose-dependent manner, but not by EP-2 and EP-4 antagonists. The EP-1 antagonist also decreased cough counts. These results suggest that PGE2 acts as an exacerbating factor for bronchoconstriction-triggered cough. EP1 and EP3 may provide new therapeutic targets for cough variant asthma.

Role of prostaglandin I2 in the bronchoconstriction-triggered cough response in guinea pigs.

Purpose/Aim of the study: Methacholine chloride (MCh) inhalation causes bronchoconstriction and cough. Following MCh-induced bronchoconstriction, metabolic products of prostaglandin I2 (PGI2) increase in bronchoalveolar lavage fluid (BALF), suggesting that PGI2 plays a role in the cough response. Accordingly, we used an experimental guinea pig model to evaluate the role of PGI2 in the bronchoconstriction-triggered cough response. MATERIALS AND METHODS: Experiment 1: The concentration of PGF1α, a stable metabolite of PGI2, in BALF was assessed in animals exposed to nebulized MCh and animals exposed to nebulized saline. Experiment 2: Bronchoconstriction and cough were assessed in 3 groups of animals after MCh inhalation (a saline group, low-dose PGI2 group, and high-dose PGI2 group). Enhanced pause (Penh) was used as a measure of bronchoconstriction. Experiment 3: Bronchoconstriction and cough were assessed in 3 groups of animals (groups administered saline, a low dose of a specific antagonist of the PGI2 receptor (IP antagonist), and a high dose of a specific IP antagonist). RESULTS: The PGF1α concentration in BALF was significantly higher in the bronchoconstriction group than in the control group. In animals administered high-dose PGI2, the MCh-induced increase in Penh was significantly suppressed, and the number of coughs induced by bronchoconstriction was significantly decreased. In animals treated with a high dose of an IP antagonist, the MCh-induced increase in Penh was not affected, and the number of coughs increased. CONCLUSIONS: Our results suggest that PGI2 ameliorates a bronchoconstriction-triggered cough. The measurement and administration of PGI2 may assist in the diagnosis and treatment, respectively, of the cough response triggered by bronchoconstriction.

The measurement of cough response to bronchoconstriction induced by methacholine inhalation in healthy subjects: An examination using the Astograph method.

BACKGROUND: We demonstrated that heightened cough response to bronchoconstriction is a fundamental feature of cough variant asthma (CVA). To evaluate this physiological feature of CVA in daily clinical practice, it is necessary to clarify the cough response to bronchoconstriction in healthy subjects. We evaluated cough response to methacholine (MCh)-induced bronchoconstriction in healthy subjects. A forced oscillometry technique was used to measure airway resistance changes with Mch. METHODS: Healthy never-smokers (21 men, 20 women; mean 22.3 ± 3.7 years) participated. None had a >3-week cough history, clinically significant respiratory or cardiovascular disorders, or disorders that might put subjects at risk or influence the study results or the subjects' ability to participate. Twofold increasing concentrations of Mch chloride diluted in phosphate-buffered saline (0.039 to 160 mg/mL) were inhaled from nebulizers at 1-minute intervals during subjects' tidal breathing after the baseline respiratory resistance (Rrs) was recorded. Mch inhalation continued until Rrs reached twice the baseline value and forced expiratory volume in 1 second (FEV1) decreased to <90% of baseline value. Spirometry was measured before Mch inhalation and immediately after Rrs had increased twofold. Coughs were counted during and for 30 minutes after Mch inhalation. The cough reflex sensitivity to capsaicin was also examined. RESULTS: The number of coughs was 11.1 ± 14.3 (median, 7.0; range, 0 to 71; reference range, 0 to 39.7). There was no significant difference in the cough response between the sexes. The reproducibility of the cough response to bronchoconstriction was sufficient. No correlation existed between the bronchoconstriction-induced cough response and capsaicin cough-reflex sensitivity. CONCLUSIONS: Using the Astograph method, cough response to bronchoconstriction could be measured easily, safely and highly reproducibly in healthy subjects.

Bronchoconstriction-triggered cough in atopic cough: A retrospective study.

BACKGROUND: Atopic cough (AC) and cough variant asthma (CVA) were identified as major causes of chronic non-productive cough in a Japanese study. A characteristic feature of CVA is the presence of a heightened cough response to bronchoconstriction. On the other hand, the cough response to bronchoconstriction in AC remains unclear. METHODS: Methacholine (Mch)-induced cough in AC was measured and compared with that in CVA. Diagnoses of AC and CVA were made based on patient history, physical examination, response to bronchodilator therapy, cough reflex sensitivity to capsaicin, spirometry, and airway responsiveness to methacholine. RESULTS: Thirteen AC patients and 12 CVA patients in whom the criteria were met were recruited to the study. After inhalation of Mch at PC35-PEF40 that means milder bronchoconstriction than PC20-FEV1, cough was triggered a few times in AC. [cough number: 1/ 32 min (0-40)]. Conversely, significantly greater number of coughs was provoked in CVA, compared with AC [cough number: 35.5/ 32 min (25-125), p < 0.05]. CONCLUSIONS: The cough response to bronchoconstriction is reduced in AC compared to CVA. This feature may be useful in the diagnosis of chronic cough.

Large lung mass lesion with spontaneous regression in a patient with IgG4-related lung disease.

IgG4-related lung disease (IgG4-RLD) may present with a variety of radiological findings, but large lung mass lesion are rare. Although steroid therapy is strongly recommended for IgG4-RLD with or without symptoms, respirologists should be aware that some patients may not need steroid therapy.

Bronchial Thermoplasty Attenuates Cough Reflex Sensitivity in Severe Asthma : A Single-Center Retrospective Study with 2-year Follow-up.

Despite the relatively short follow-up period in our previous study, we had reported that increased cough reflex sensitivity (CRS) may predict the efficacy of bronchial thermoplasty (BT) for treating asthma. Herein, we examined whether CRS predicts the efficacy of BT 2 years after the final BT treatment. We also investigated the influence of BT on CRS. We reviewed 10 patients 2 years after their final BT treatment. CRS, asthma-related symptoms, asthma exacerbations, and cough-related quality of life were assessed at baseline and 2 years after BT. Five patients responded positively to BT (BT responders) and their asthma control improved. No significant difference in CRS at baseline was detected between the BT responders and nonresponders. In contrast, BT responders exhibited significant improvements in CRS 2 years after BT. CRS at baseline could not predict the BT efficacy after 2 years. This is the first report demonstrating BT desensitized CRS in consecutive case series. J. Med. Invest. 70 : 271-275, February, 2023.

Nivolumab-Induced Polymyalgia Rheumatica in a Patient with Lung Adenocarcinoma.

A 79-year-old woman was diagnosed with stage IV (cT1aN1M1, OSS) lung adenocarcinoma with bone metastasis of the right femur. She received nivolumab as a third-line treatment. She developed pain in the right shoulder, left wrist, right knee, and waist as well as a low-grade fever and morning stiffness, after five courses of nivolumab. After closer examination, she was diagnosed with polymyalgia rheumatica (PMR) precipitated by an immune-related adverse event. Nivolumab was discontinued, and oral prednisolone was started. Her arthralgia improved. Caution should be exercised regarding the development of PMR when polyarthralgia occurs during nivolumab treatment in patients with lung cancer.

Successful Treatment of Advanced Thymic Carcinoma with Carboplatin plus nab-Paclitaxel and Maintenance Monotherapy with nab-Paclitaxel: Two Case Reports.

A standard chemotherapy regimen for advanced thymic carcinoma has not yet been established. We treated 2 cases of thymic carcinoma with carboplatin plus nanoparticle albumin-bound (nab)-paclitaxel, and nab-paclitaxel maintenance therapy. The first case was a 68-year-old female, admitted for dyspnea and left shoulder pain. Chest computed tomography (CT) showed a huge mass in the anterior mediastinum, pleural and pericardial effusions, and multiple lung metastases. Specimens obtained from the anterior mediastinal mass by CT-guided needle biopsy revealed squamous cell carcinoma of the thymus, which was in stage IVB. The patient was administered carboplatin plus nab-paclitaxel as first-line treatment. After 3 cycles of chemotherapy, a partial response was observed with marked shrinkage of the tumor. Following 6 cycles of chemotherapy, nab-paclitaxel maintenance therapy was initiated. Disease progression was seen 9.1 months after initiation of treatment. The patient experienced no serious adverse events. The second case was a 70-year-old male who had productive cough, dyspnea, and right-sided chest pain. Chest CT revealed a huge mass in the anterior mediastinum, pericardial effusion, and multiple lymphadenopathies. Specimens obtained from station 11s by endobronchial ultrasound-guided transbronchial needle aspiration revealed undifferentiated thymic carcinoma, which was in stage IVB. Six cycles of carboplatin plus nab-paclitaxel were administered, followed by 5 cycles of nab-paclitaxel for maintenance. A partial response was seen, which was sustained for more than 13 months. The patient experienced no serious adverse events. These cases show that chemotherapy with carboplatin plus nab-paclitaxel and nab-paclitaxel as maintenance therapy can be a useful regimen for advanced thymic carcinoma.

Histopathological Type of Lung Cancer and Underlying Driver Mutations in Patients with Chronic Obstructive Pulmonary Disease (COPD) versus Patients with Asthma and COPD Overlap: A Single-Center Retrospective Study.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) increases the risk of lung cancer. The relationships between COPD and Asthma COPD Overlap (ACO), and between the histopathological types of lung cancer and driver mutations remain unclear and need further study. The aim of this retrospective study was to examine the relationships between the histopathological type, frequency of epidermal growth factor receptor (EGFR) driver mutations, and anaplastic lymphoma receptor tyrosine kinase (ALK) rearrangements in the lung cancers of patients with COPD and ACO. MATERIALS AND METHODS: Patients with pure COPD (n=198) or ACO (n=318) who were admitted to our hospital were reviewed retrospectively. RESULTS: Lung cancers were identified in 43 (21.7%) patients with pure COPD and 54 (17.0%) patients with ACO. The following lung cancers types were observed: patients with pure COPD had 19 (44.2%) adenocarcinomas, 13 (30.2%) squamous cell lung carcinomas (SCC), 8 (18.6%) small cell lung carcinomas (SCLC); patients with ACO had 23 (42.6%) adenocarcinomas, 23 (42.6%) SCC, 2 (3.70%) SCLC. SCLC was significantly more prevalent in patients with pure COPD (p<0.05) than in those with ACO. Differences between the numbers of other histological types of lung cancer and the numbers of driver mutations in the 2 groups of patients were not significant. CONCLUSION: The differences in the rate of lung cancer and prevalence of EGFR driver mutations between the patients with pure COPD and those with ACO were not significant.

A Single Institution Retrospective Study of the Clinical Efficacy of Tiotropium Respimat in Never-Smoking Elderly Asthmatics with Irreversible Airflow Limitation.

OBJECTIVE: In Japan, most asthma deaths occur among the elderly. We should improve the control of asthma in elderly patients to reduce the number of deaths due to asthma. This retrospective study aimed to evaluate the efficacy of tiotropium RespimatⓇ (Tio-Res) in symptomatic, never-smoking, elderly asthmatics with irreversible airflow limitation despite the use of high-dose inhaled corticosteroids (ICS) plus long-acting ß2-adrenoceptor agonists (LABA). METHODS: The Asthma Control Test™ (ACT), pulmonary function tests, morning and evening peak flow (mPEF, ePEF, respectively, evaluated with an ASSESS® peak flow meter), and respiratory impedance (assessed with MostGraph®) were measured before and after a minimum of one year of Tio-Res 5 µg/day administration. Sixteen symptomatic, never-smoking asthmatics, aged 75 or over with irreversible airflow limitation despite the use of high-dose ICS plus LABA, were analyzed. RESULTS: All patients were female (mean age, 81.6 years). Tio-Res led to statistically significant improvements in the total ACT score (19.9 to 23.6), FVC and FEV1 (1.97 to 2.14 L and 1.13 to 1.23 L, respectively), and mPEF and ePEF (229.9 to 253.8 L/min and 259.8 to 277.4 L/min, respectively). Tio-Res also resulted in statistically significant improvements in respiratory resistance at 5 Hz (R5), respiratory resistance at 20 Hz (R20), R5-R20, low-frequency reactant indices at 5 Hz (X5), resonant frequency (Fres) and low-frequency reactance area (ALX). CONCLUSIONS: Our retrospective study suggests that Tio-Res improves symptoms, pulmonary function, and respiratory impedance in symptomatic asthmatics aged 75 or over with irreversible airflow limitation despite the use of high-dose ICS plus LABA.

Real-World Evidence of Safety and Efficacy of Carboplatin plus Nanoparticle Albumin-Bound Paclitaxel in Patients with Advanced Non-Small-Cell Lung Cancer and Preexisting Interstitial Lung Disease: A Retrospective Study.

Background: Standard chemotherapy for advanced non-small-cell lung cancer (NSCLC) with preexisting interstitial lung disease (ILD) has not yet been established. Although a combination of carboplatin and paclitaxel is most frequently used for patients with advanced NSCLC and ILD, the safety and efficacy of carboplatin plus nanoparticle albumin-bound paclitaxel (nab-paclitaxel) are yet to be elucidated. Objectives: This study aimed to evaluate the safety and efficacy of carboplatin plus nab-paclitaxel for advanced NSCLC with ILD. Methods: This retrospective study included nine patients with advanced NSCLC and ILD who received carboplatin plus nab-paclitaxel as first-line chemotherapy at the National Hospital Organization Kanazawa Medical Center between April 2013 and December 2017. The ILD-GAP index was used to evaluate mortality risk of baseline ILD. Results: A usual interstitial pneumonia (UIP) pattern of ILD was observed in five (55.6%) patients on their baseline high-resolution computed tomography (HRCT) scans. The median ILD-GAP index was 4 (range, 1-5), and six (66.7%) patients had ILD-GAP index ≥4. We observed no ILD exacerbations or chemotherapy-related deaths. The overall response and disease control rates were 77.8% (95% CI, 40.0-97.2) and 88.9% (95% CI, 51.8-97.2), respectively. The median progression-free survival and overall survival were 5.8 months (95% CI, 2.1-7.7) and 8.0 months (95% CI, 2.6-16.8), respectively. Conclusions: Carboplatin plus nab-paclitaxel showed favorable safety and efficacy in patients who had advanced NSCLC and ILD with a high risk of mortality. Prospective studies are required to further confirm these results.

Selective gene amplification to detect the T790M mutation in plasma from patients with advanced non-small cell lung cancer (NSCLC) who have developed epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) resistance.

BACKGROUND: The epidermal growth factor receptor (EGFR) T790M mutation is associated with resistance to EGFR tyrosine kinase inhibitors (EGFR-TKIs) in non-small cell lung cancer (NSCLC). However, tissues for the genotyping of the EGFR T790M mutation can be difficult to obtain in a clinical setting. The aims of this study were to evaluate a blood-based, non-invasive approach to detecting the EGFR T790M mutation in advanced NSCLC patients using the PointMan™ EGFR DNA enrichment kit, which is a novel method for the selective amplification of specific genotype sequences. METHODS: Blood samples were collected from NSCLC patients who had activating EGFR mutations and who were resistant to EGFR-TKI treatment. Using cell-free DNA (cfDNA) from plasma, EGFR T790M mutations were amplified using the PointMan™ enrichment kit, and all the reaction products were confirmed using direct sequencing. The concentrations of plasma DNA were then determined using quantitative real-time PCR. RESULTS: Nineteen patients were enrolled, and 12 patients (63.2%) were found to contain EGFR T790M mutations in their cfDNA, as detected by the kit. T790M mutations were detected in tumor tissues in 12 cases, and 11 of these cases (91.7%) also exhibited the T790M mutation in cfDNA samples. The concentrations of cfDNA were similar between patients with the T790M mutation and those without the mutation. CONCLUSIONS: The PointMan™ kit provides a useful method for determining the EGFR T790M mutation status in cfDNA.

Immunoglobulin G4-related disease preceded by lung involvement: A case report.

RATIONALE: Immunoglobulin G4-related disease (IgG4-RD) is a systemic condition involving various organs and vessels including the pancreas, bile duct, salivary glands, periorbital tissues, kidneys, lungs, lymph nodes, meninges, and aorta. Recently, some cases of IgG4-RD have been reported, in which only pulmonary lesions were present. It is not known whether IgG4-RD can be diagnosed on the basis of pulmonary lesions only, because increases in serum IgG4 levels and infiltration of IgG4-positive plasma cells into the lung tissue also occur in other inflammatory conditions. A case of IgG-RD that was followed-up for 7 years after onset is described. PATIENT CONCERNS: Initially, only pulmonary lesions were present; however, other lesions in the submandibular glands, pancreas, periarterial region, and other areas occurred over time, with a gradual increase in serum IgG4 levels. DIAGNOSES, INTERVENTIONS, AND OUTCOMES: Histopathology results from the patient's submandibular gland confirmed the diagnosis of IgG4-RD. Following diagnosis, the patient was treated with corticosteroids immediately, and his symptoms disappeared rapidly. LESSONS: Because other diseases, including malignancies, mimic IgG4-RD in clinical and histopathological features, an absolute diagnosis is necessary to avoid missing the presence of underlying diseases. This case more provides insight into the clinical pathology of IgG4-RD.