Misato Amenomori

Plectasin has antibacterial activity and no affect on cell viability or IL-8 production

Animals and plants express endogenous peptide antibiotics called defensins. Defensins show broad-spectrum antimicrobial activity, even against bacteria that have resistance to conventional antibiotics, which has made them viable candidates for new antibiotics. However, human defensins have failed to reach the market because of their cytotoxic effects and non-antimicrobial bioactivities. Plectasin is a defensin that has shown promise but has not had its potentially negative effects clarified. To address this issue, we examined plectasins cytotoxicity in human cells using an AlamarBlue reduction assay, its interleukin (IL)-8-inducing capacity using real-time PCR and ELISA, and measured its MIC against bacteria. We confirmed that plectasin has specific antibacterial activity against Streptococcus pneumoniae. Plectasin showed no cytotoxicity to A549 cells, normal human bronchial epithelial cells, or lung fibroblasts, and it did not induce IL-8 transcription or production in A549 cells. Our results suggest that plectasin could be an inoffensive alternative antibiotic for clinical application.

Two Cases With Pulmonary Mucosa-Associated Lymphoid Tissue Lymphoma Successfully Treated With Clarithromycin

A 70-year-old woman with a history of sinobronchial syndrome was admitted to the hospital because of a cough, sputum, and abnormal chest shadow. She was diagnosed with pulmonary mucosa-associated lymphoid tissue lymphoma (p-MALToma) based on results of a pathologic examination and the gene rearrangements in the Ig heavy chain on Southern blot hybridization. Although p-MALToma did not regress with conventional therapy, it was reduced after long-term treatment with clarithromycin (CAM) (200 mg/d). A 57-year-old woman with a history of Sjögren syndrome and lymphocytic interstitial pneumonia had a mass lesion in the left lower lung field. CT image-guided biopsy established a diagnosis of p-MALToma. The p-MALToma regressed with long-term treatment with CAM (200 mg/d), whereas Helicobacter pylori (HP) eradication therapy was not effective in concurrent atrophic gastritis with HP. It is suggested that CAM, a macrolide antibiotic, may be effective in some patients with p-MALToma.

Different effects of telithromycin on MUC5AC production induced by human neutrophil peptide-1 or lipopolysaccharide in NCI-H292 cells compared with azithromycin and clarithromycin

OBJECTIVES Mucus hypersecretion is a prominent feature in patients with chronic respiratory tract infections such as cystic fibrosis and diffuse panbronchiolitis, and the clinical effectiveness of macrolide antibiotics has been reported in these patients. Because human neutrophil peptide-1 (HNP-1), an antimicrobial peptide in neutrophils, exists in high concentrations in the airway fluid of these patients, we examined the direct effect of HNP-1 on MUC5AC mucin production using NCI-H292 cells. The effects of macrolide antibiotics on the response were also examined. METHODS MUC5AC synthesis was assayed using RT-PCR and ELISA. Phosphorylation of ERK1/2 was determined by western blotting. RESULTS Stimulation with HNP-1 or lipopolysaccharide (LPS) derived from Pseudomonas aeruginosa increases the production of MUC5AC mRNA and protein, and an additive effect was found upon co-stimulation with both HNP-1 and LPS. Azithromycin and clarithromycin had inhibitory effects on overproduction of MUC5AC induced by HNP-1 or LPS stimulation. Telithromycin also had an inhibitory effect on MUC5AC production induced by LPS, but not on production by HNP-1. Phosphorylation of ERK1/2 was induced by HNP-1 or LPS stimulation, and azithromycin, clarithromycin and telithromycin had inhibitory effects on ERK1/2 phosphorylation induced by LPS, but not by HNP-1. CONCLUSIONS These findings suggest that neutrophil-derived defensins as bacterial components contribute to excessive mucus production in patients with respiratory tract infections, and that macrolide and ketolide antibiotics directly inhibit these actions by interfering with intracellular signal transduction. However, the mechanism of telithromycin inhibition of MUC5AC synthesis may differ from the response induced by azithromycin and clarithromycin.

Differential effects of human neutrophil peptide-1 on growth factor and interleukin-8 production by human lung fibroblasts and epithelial cells

ABSTRACT α-Defensins, antimicrobial peptides produced mainly by neutrophils, have been reported to be associated with a wide variety of lung diseases, including idiopathic pulmonary fibrosis (IPF), cystic fibrosis (CF), and diffuse panbronchiolitis (DPB). In each disease, α-defensins are located in different areas, such as around the alveolar septa in IPF and around the airways in CF and DPB, suggesting that α-defensins play different roles. Meanwhile, growth factors are known to contribute to IPF, CF, and DPB. α-Defensins are known to induce interleukin (IL)-8 in airway epithelial cells, but the effects of α-defensins on the release of growth factors from various components in the lung have not been sufficiently investigated. In the present study, the in vitro effects of human neutrophil peptide (HNP)-1 (a subtype of α-defensin) on the expressions of IL-8 and growth factors in lung fibroblasts, bronchial epithelial cells, and alveolar epithelial cells were examined. HNP-1 mainly enhanced the expression of IL-8 in epithelial cells, whereas it enhanced transforming growth factor-β and vascular endothelial growth factor expressions in lung fibroblasts. These results suggest that α-defensins play different roles in the pathogenesis of IPF, CF, and DPB according to the location in the lung where the α-defensins are mainly produced.

Effects of Doxycycline on Production of Growth Factors and Matrix Metalloproteinases in Pulmonary Fibrosis

Background: Idiopathic pulmonary fibrosis (IPF) is characterized by progressive fibrosis and a poor prognosis. Alveolar epithelial cells (AECs) are considered to play important roles by releasing growth factors and matrix metalloproteinases (MMPs) and by being involved in epithelial mesenchymal transition in IPF. Doxycycline hydrochloride (DOXY), an inhibitor of MMPs, attenuates pulmonary fibrosis in models and in patients with IPF; however, the mechanism of this action remains obscure. Objectives: The present study investigated the effect of DOXY on growth factors and MMP production in AECs. Methods: Bleomycin (BL)-induced murine pulmonary fibrosis was treated with DOXY and examined by pathological and immunohistochemical staining. The human alveolar epithelial cell line A549 was stimulated with transforming growth factor (TGF)-β1 and incubated with DOXY, and then the expression of growth factors, MMPs, and collagen type I was evaluated at the mRNA and protein levels. We also evaluated the effects of DOXY on the TGF-β1-induced Smad signaling pathway. Results: DOXY reduced fibrosis scores and the production of collagen type I, connective tissue growth factor (CTGF), and TGF-β1 in BL models. DOXY inhibited the mRNA expression of MMP-2, MPP-9, CTGF, and collagen type I as well as the production of MMP-2 and platelet-derived growth factor-AA protein induced in A549 cells by TGF-β1 but not by Smad2 and Smad3 phosphorylation. We did not find a similar effect of DOXY in normal lung fibroblasts. Conclusions: Our results suggest that DOXY could be useful for attenuating pulmonary fibrosis through the inhibition of growth factors and MMP production in AECs.

Immediate single lobar retransplantation for primary graft dysfunction after living-donor lobar lung transplantation: Report of a case

A 24-year-old man with cystic fibrosis underwent living-donor lobar lung transplantation (LDLLT) with grafts donated from his father, who had mild cirrhosis, and his uncle. The graft from his father failed, and retransplantation was required 44 h after LDLLT, using his sister’s left lower lobe. The retransplantation was successful; 18 months postoperatively, the recipient and all three donors are doing well. The favorable outcome was achieved owing to the complete assessment of all potential donors in advance, and the appropriate decision to perform retransplantation in a timely manner. Whether this life-saving retransplant procedure for unexpected primary graft dysfunction after LDLLT can be justified requires further experience and a longer follow-up.

Dyspnea with a Slow-Growing Mass in the Breast

Chest radiography showed multiple nodular opacities in both peripheral lung fields. Thin-section CT of the chest revealed multiple tiny nodules and centrilobular branching opacities in the subpleural regions of both lung fields ( fig. 1 a). Wedge-shaped or irregularly shaped nodular opacities suggesting pulmonary infarction were also seen in subpleural distribution ( fig. 1 b). On contrastenhanced CT of the mediastinal window setting, a wellenhanced mass in the left breast, up to 3 cm in diameter, was seen ( fig. 1 c). No mediastinal or hilar lymphadenopathy was identified. There were no pleural effusions. The patient underwent bronchoscopy that showed normal endobronchial mucosa. Bronchoalveolar lavage was not diagnostic; no organisms or malignant cells were seen on lavage fluid stains, and the fluid was sterile. Transbronchial lung biopsy (TBLB) was performed from right B 4 . Pathologically, scattered thrombi involving small pulmonary arteries and arterioles were seen. Simultaneously, a ventilation-perfusion lung scintigram was performed. Multiple minute defects in the peripheral lung fields just under the pleura were seen on the perfusion scintigram, while the ventilation scintigram showed normal ventilation. In view of these findings, what is your diagnosis? A 48-year-old Japanese woman presented with a 6month history of increasing exertional dyspnea and dry cough. She denied fever, night sweats, or weight loss. She was a nonsmoker. Her medical history was unremarkable except for the fact that she had been aware of a mass in her left breast for 1 2 years. On admission, her temperature was 36.7 ° C, her pulse was regular at 70 b.p.m., and her respiratory rate was 16 breaths/min. Her lungs were clear on auscultation, and cardiac examination revealed no murmur or gallops. No edema or varicosities were seen in her lower extremities. A hard mass measuring up to 3 cm in diameter was palpable in her left breast. Oxygen saturation was 94% on room air. Arterial blood gases on room air were pH 7.404, Pa CO 2 5.5 kPa (40.9 mm Hg), Pa O 2 9.3 kPa (69.4 mm Hg), and A-a DO 2 4.2 kPa (31.5 mm Hg). On laboratory examination, the complete blood count and basic chemistries were within the normal ranges. D-dimer was 2.5 (normal value ! 1.0) g/ml, and the thrombin-antithrombin III complex was 7.0 (normal value 3.0) ng/ml. Fibrinogen and fibrinogen degradation products were within their normal ranges. The results of pulmonary function tests were: VC 1.86 liters, %VC 69.1%, FEV 1.0 1.88 liters, FEV 1.0 % 100.0%, DL CO 8.37 ml/mm/mm Hg, and %DL CO 51.4%. Echoand electrocardiograms disclosed no findings of cardiac failure or pulmonary hypertension. Received: January 7, 2009 Accepted after revision: October 5, 2009 Published online: December 3, 2009

A Case of Pseudoangiomatous Stromal Hyperplasia of the Breast Presenting with Chest Pain

Pseudoangiomatous stromal hyperplasia is a rare, benign, breast disease characterized by dense, collagenous proliferation of mammary stroma, forming interanastomosing capillary-like spaces. Previously reported cases presented with a palpable breast mass or continuous breast enlargement, or were unexpectedly detected on mammography or ultra- sonography. However, cases presenting only with pain as the initial symptom have not been reported. In this report, we describe a case of pseudoangiomatous stromal hyperplasia that presented with intermittent dull chest pain. A 2.6 � 1.1 cm, well-defined, hypoechoic mass was noted in the breast on ultrasonography, and an excisional biopsy was performed. On pathology, the tumor showed stromal hyperplasia and vessel-like slit structures. Immunohistochemical staining for vimentin, CD34, CD31, and Factor VIII-related antigen was compatible with pseudoangiomatous stromal hyperplasia. The dull chest pain disappeared after the excision. Pseudoangiomatous stromal hyperplasia is often described as painless. However, chest pain could also be an initial symptom.