Transcriptome studies of inherited dilated cardiomyopathies.

Dilated cardiomyopathy (DCM) is a group of heart muscle diseases that often lead to heart failure, with more than 50 causative genes have being linked to DCM. The heterogenous nature of the inherited DCMs suggest the need of precision medicine. Consistent with this emerging concept, transcriptome studies in human patients with DCM indicated distinct molecular signature for DCMs of different genetic etiology. To facilitate this line of research, we reviewed the status of transcriptome studies of inherited DCMs by focusing on three predominant DCM causative genes, TTN, LMNA, and BAG3. Besides studies in human patients, we summarized transcriptomic analysis of these inherited DCMs in a variety of model systems ranging from iPSCs to rodents and zebrafish. We concluded that the RNA-seq technology is a powerful genomic tool that has already led to the discovery of new modifying genes, signaling pathways, and related therapeutic avenues. We also pointed out that both temporal (different pathological stages) and spatial (different cell types) information need to be considered for future transcriptome studies. While an important bottle neck is the low throughput in experimentally testing differentially expressed genes, new technologies in efficient animal models such as zebrafish starts to be developed. It is anticipated that the RNA-seq technology will continue to uncover both unique and common pathological events, aiding the development of precision medicine for inherited DCMs.

Rheumatoid pulmonary nodules: clinical and imaging features compared with malignancy.

OBJECTIVES: The objective of this study was to identify clinical and imaging features that distinguish rheumatoid lung nodules from malignancy. METHODS: We conducted a retrospective review of 73 rheumatoid patients with histologically-proven rheumatoid and malignant lung nodules encountered at Mayo Clinic, Rochester, MN (2001-2016). Medical records and imaging were reviewed including a retrospective blinded review of CT and PET/CT studies. RESULTS: The study cohort had a mean age of 67 ± 11 years (range 45-86) including 44 (60%) women, 82% with a smoking history, 38% with subcutaneous rheumatoid nodules, and 78% with rheumatoid factor seropositivity. Subjects with rheumatoid lung nodules compared to malignancy were younger (59 ± 12 vs 71 ± 9 years, p < 0.001), more likely to manifest subcutaneous rheumatoid nodules (73% vs 20%, p < 0.001) and rheumatoid factor seropositivity (93% vs 68%, p = 0.034) but a history of smoking was common in both groups (p = 0.36). CT features more commonly associated with rheumatoid lung nodules compared to malignancy included multiplicity, smooth border, cavitation, satellite nodules, pleural contact, and a subpleural rind of soft tissue. Optimal sensitivity (77%) and specificity (92%) (AUC 0.85, CI 0.75-0.94) for rheumatoid lung nodule were obtained with ≥ 3 CT findings (≥ 4 nodules, peripheral location, cavitation, satellite nodules, smooth border, and subpleural rind). Key 18FDG-PET/CT features included low-level metabolism (SUVmax 2.7 ± 2 vs 7.2 ± 4.8, p = 0.007) and lack of 18F-fluorodeoxyglucose (FDG)-avid draining lymph nodes. CONCLUSION: Rheumatoid lung nodules have distinct CT and PET/CT features compared to malignancy. Patients with rheumatoid lung nodules are younger and more likely to manifest subcutaneous rheumatoid nodules and seropositivity. KEY POINTS: • Rheumatoid lung nodules have distinct clinical and imaging features compared to lung malignancy. • CT features of rheumatoid lung nodules include multiplicity, cavitation, satellite nodules, smooth border, peripheral location, and subpleural rind. • Key PET/CT features include low-level metabolism and lack of FDG-avid draining lymph nodes.

Computed Tomography Angiography Findings in Pulmonary Embolism Patients Vary Following Thrombolytic Treatment.

BACKGROUND: Pulmonary embolism (PE) is the third most frequently occurring cardiovascular disease. However, the clinical presentation in patients with PE is variable. OBJECTIVES: To evaluate the prevalence of radiological findings detected in contrast-enhanced computed tomography angiography (CTA) and their significance in patients with PE; and to assess whether the CTA findings differed in patients receiving tissue plasminogen activator (tPA) therapy from those who did not. METHODS: We retrospectively reviewed CTA scans of 186 patients diagnosed with acute PE. Incidental findings on CTA scan were assessed, including mediastinal and parenchymal lymph nodes, pleural effusion, space-occupying lesions, consolidations, emphysema, and pericardial effusion. RESULTS: Patients receiving tPA (19.9%) were less likely to have pleural effusion (29.7% vs. 50.3%, P = 0.024). Other CTA findings did not differ between the tPA and non-tPA groups, including lung infiltrates (40.5% vs. 38.9, P = 0.857), space-occupying lesions (5.4% vs. 6.7%, P = 1), pericardial effusion (8.1% vs. 8.7%, P = 1), emphysema (21.6% vs. 17.4%, P = 0.557), lung (18.9% vs. 24.2%, P = 0.498), and mediastinal ( 24.3% vs. 25.5%, P = 0.883) lymph nodes, respectively. CONCLUSIONS: The prevalence of pleural effusion (unilateral or bilateral) was higher in patients not treated with tPA. Therefore, in patients with a borderline condition, the presence of pleural effusion could support the decision not to give tPA treatment.

[DIAGNOSIS AND TREATMENT OF BRONCHIECTASIS: POSITION PAPER OF THE ISRAELI PULMONOLOGY SOCIETY AND THE ISRAELI PEDIATRIC PULMONOLOGY SOCIETY].

INTRODUCTION: Bronchiectasis is anatomically defined by irreversible distortion of the bronchi. Clinically, its manifestations are cough with sputum production and a predisposition to pulmonary infections. Unlike asthma and COPD, where ample clinical data are present regarding the course and effective treatment, knowledge of bronchiectasis has yet to evolve. Lately, bronchiectasis is gaining renewed attention among the medical community, with growing basic and clinical research-based data. In Israel, no registered treatments exist for bronchiectasis, which makes it difficult to treat these patients. This paper is a summary of the position of the Israeli Pulmonology Association and the Israeli Pediatric Pulmonology Association for diagnosis and treatment of bronchiectasis.

Selective oral ROCK2 inhibitor down-regulates IL-21 and IL-17 secretion in human T cells via STAT3-dependent mechanism.

Rho-associated kinase 2 (ROCK2) regulates the secretion of proinflammatory cytokines and the development of autoimmunity in mice. Data from a phase 1 clinical trial demonstrate that oral administration of KD025, a selective ROCK2 inhibitor, to healthy human subjects down-regulates the ability of T cells to secrete IL-21 and IL-17 by 90% and 60%, respectively, but not IFN-γ in response to T-cell receptor stimulation in vitro. Pharmacological inhibition with KD025 or siRNA-mediated inhibition of ROCK2, but not ROCK1, significantly diminished STAT3 phosphorylation and binding to IL-17 and IL-21 promoters and reduced IFN regulatory factor 4 and nuclear hormone RAR-related orphan receptor γt protein levels in T cells derived from healthy subjects or rheumatoid arthritis patients. Simultaneously, treatment with KD025 also promotes the suppressive function of regulatory T cells through up-regulation of STAT5 phosphorylation and positive regulation of forkhead box p3 expression. The administration of KD025 in vivo down-regulates the progression of collagen-induced arthritis in mice via targeting of the Th17-mediated pathway. Thus, ROCK2 signaling appears to be instrumental in regulating the balance between proinflammatory and regulatory T-cell subsets. Targeting of ROCK2 in man may therefore restore disrupted immune homeostasis and have a role in the treatment of autoimmunity.

A novel technique for CT-guided transthoracic biopsy of lung lesions: improved biopsy accuracy and safety.

OBJECTIVES: To present the diagnostic accuracy and safety of a novel technique for CT-guided transthoracic needle aspiration biopsy (TNAB) of lung lesions suspected of malignancy. METHODS: A novel technique for coaxial CT-guided TNAB is reported in this single-centre, retrospective study. A 22-gauge guide wire is used to accurately locate the lesion prior to biopsy. The technique enables penetration of lung lesions in various locations with less risk of harm to adjacent organs. Malignant and benign diagnoses were confirmed by histology or radiologic resolution. RESULTS: Clinical features of 181 patients included 59% men. Mean lesion size was 24 ± 14.9 mm with a mean depth of 13.6 ± 18.3 mm. Among 160 (88.4%) confirmed malignancies, 151 (94.4%) were diagnosed with TNAB. Among the 13 (7.2%) confirmed benign diagnoses, 11 (84.6%) received a specific, benign diagnosis with TNAB. The overall diagnostic accuracy of CT-TNAB was 93.6% among all confirmed diagnoses (173/181). Complications included 48 (26.5%) with pneumothorax, of which 77.8% resolved spontaneously, 20% by aspiration and 2.2% required chest drain insertion. Intrapulmonary haemorrhage was observed in 3.9% and hemoptysis in 6.0% without clinical significance. CONCLUSION: The guide wire technique provides a novel method for needle biopsy of lung lesions with improved accuracy and safety. KEY POINTS: Lung cancer screening has increased the detection of lung lesions. The guide wire technique is a novel method to biopsy lung lesions. The guide wire technique for lung biopsy demonstrates improved accuracy and safety. The chest tube insertion rate is reduced with aspiration during the procedure.

Manifestations and management of Sjögren's disease.

Sjögren's disease is a heterogeneous autoimmune disorder that may be associated with systemic manifestations such as pulmonary or articular involvement. Systemic complications have prognostic implications and need to be identified and managed in a timely manner. Treatment should be tailored to the type and severity of organ involvement, ideally based on multidisciplinary evaluation.

Kidney transcriptome and cystic kidney disease genes in zebrafish.

Introduction: Polycystic kidney disease (PKD) is a condition where fluid filled cysts form on the kidney which leads to overall renal failure. Zebrafish has been recently adapted to study polycystic kidney disease, because of its powerful embryology and genetics. However, there are concerns on the conservation of this lower vertebrate in modeling polycystic kidney disease. Methods: Here, we aim to assess the molecular conservation of zebrafish by searching homologues polycystic kidney disease genes and carrying transcriptome studies in this animal. Results and Discussion: We found that out of 82 human cystic kidney disease genes, 81 have corresponding zebrafish homologs. While 75 of the genes have a single homologue, only 6 of these genes have two homologs. Comparison of the expression level of the transcripts enabled us to identify one homolog over the other homolog with >70% predominance, which would be prioritized for future experimental studies. Prompted by sexual dimorphism in human and rodent kidneys, we studied transcriptome between different sexes and noted significant differences in male vs. female zebrafish, indicating that sex dimorphism also occurs in zebrafish. Comparison between zebrafish and mouse identified 10% shared genes and 38% shared signaling pathways. String analysis revealed a cluster of genes differentially expressed in male vs. female zebrafish kidneys. In summary, this report demonstrated remarkable molecular conservation, supporting zebrafish as a useful animal model for cystic kidney disease.

Lymphangioleiomyomatosis and Other Cystic Lung Diseases.

Cysts and cavities in the lung are commonly encountered on chest imaging. It is necessary to distinguish thin-walled lung cysts (≤2 mm) from cavities and characterize their distribution as focal or multifocal versus diffuse. Focal cavitary lesions are often caused by inflammatory, infectious, or neoplastic processes in contrast to diffuse cystic lung diseases. An algorithmic approach to diffuse cystic lung disease can help narrow the differential diagnosis, and additional testing such as skin biopsy, serum biomarkers, and genetic testing can be confirmatory. An accurate diagnosis is essential for the management and disease surveillance of extrapulmonary complications.

Diagnosis and Management of Interstitial Lung Disease in Patients with Connective Tissue Diseases.

Interstitial lung disease (ILD) associated with connective tissue diseases (CTDs) is highly heterogeneous in its clinical presentation and course. The diagnosis and management of CTD-ILD require a multidisciplinary approach involving, at minimum, a rheumatologist, a pulmonologist, and a radiologist. Close monitoring of patients with CTD-ILD is important to enable early detection of disease progression and inform decisions regarding the initiation or escalation of pharmacotherapy. In the absence of guidelines regarding how CTD-ILDs should be treated, clinicians face difficult decisions on when to use immunosuppressant and anti-fibrotic therapies. The importance of a multidisciplinary and individualized approach to the diagnosis and management of CTD-ILD is highlighted in the three case studies that we describe in this article.

Design and rationale of a randomised, double-blind trial of the efficacy and safety of pirfenidone in patients with fibrotic hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is an immunologically mediated form of lung disease resulting from inhalational exposure to any of a large variety of antigens. A subgroup of patients with HP develops pulmonary fibrosis (fibrotic HP; FHP), a significant cause of morbidity and mortality. This study will evaluate the safety and efficacy of the antifibrotic pirfenidone in treating FHP. This single-centre, randomised, double-blind, placebo-controlled trial is enrolling adults with FHP (ClinicalTrials.gov: NCT02958917). Study participants must have fibrotic abnormalities involving ≥5% of the lung parenchyma on high-resolution computed tomography scan, forced vital capacity (FVC) ≥40% and diffusing capacity of the lung for carbon monoxide ≥30% of predicted values. Study participants will be randomised in a 2:1 ratio to receive pirfenidone 2403 mg·day-1 or placebo. The primary efficacy end-point is the mean change in FVC % predicted from baseline to week 52. A number of secondary end-points have been chosen to evaluate the safety and efficacy in different domains.

Systemic Thrombolysis Therapy is Associated With Improved Outcomes Among Patients With Acute Pulmonary Embolism and Respiratory Failure.

BACKGROUND: Thrombolytic therapy is widely accepted for massive pulmonary embolism (PE) due to the high mortality risk associated with standard anticoagulation alone. Its role in submassive PE, however, has remained controversial. We aimed to evaluate whether the selective use of systemic thrombolytic therapy with intravenous tissue plasminogen activator (IV-tPA) improves the survival of patients with submassive PE at increased risk for clinical deterioration. METHODS: A total of 184 consecutive patients diagnosed with acute PE by chest thoracic angiography (CTA) were included in a retrospective study. Pulmonary artery obstruction and right/left ventricular dysfunction were evaluated by CTA and echocardiography. Medical history and simplified PE Severity Index (sPESI) were assessed at diagnosis. Hemodynamic and respiratory status were recorded at diagnosis, admission to pulmonary unit and prior to thrombolytic therapy. Patient survival was assessed at 30 of 90 days from diagnosis by CTA. RESULTS: All low risk patients (36%) per sPESI survived. Among the 117 remaining patients, 31% received IV-tPA. Respiratory failure was associated with decreased age-adjusted survival (P = 0.005). Among patients with respiratory failure selected for IV-tPA, age-adjusted survival was improved significantly compared to others (P = 0.043). CONCLUSIONS: Thrombolytic therapy for hemodynamically stable PE patients with respiratory failure may improve survival. TRIAL REGISTRATION: MMC-0216-14.

A 48-Year-Old South African Woman with Rheumatoid Arthritis and Lung Nodules.

CASE PRESENTATION: We present the case of a 48-year-old South African woman with no smoking history, and seropositive rheumatoid arthritis diagnosed in 2001. She was treated with chloroquine (150 mg, 4 times per week) and methotrexate (30 mg weekly) with well-controlled symptoms until 2015, when she developed a disease flare. Her treatment regimen was changed to leflunomide (20 mg daily) monotherapy with subsequent symptom control. Biologic agents were not accessible because of cost constraints.

Bronchoscopic Cryobiopsy and Forceps Biopsy for the Diagnostic Evaluation of Diffuse Parenchymal Lung Disease in Clinical Practice.

OBJECTIVE: To assess the contribution and safety of bronchoscopic cryobiopsy vs traditional forceps biopsy used in clinical practice for diagnosing diffuse parenchymal lung disease (DPLD). PATIENTS AND METHODS: We identified 271 patients who underwent bronchoscopic biopsy for DPLD at Mayo Clinic, MN (June 1, 2013, through September 30, 2017). Medical records were reviewed including prebiopsy clinical and radiographic impressions. Diagnostic yield was assessed in terms of a specific histologic pattern resulting in a diagnosis when combined with the clinical-radiologic context. Clinical utility was defined as a biopsy result deemed useful in patient management. RESULTS: The cohort included 120 cryobiopsy and 151 forceps biopsy cases with mean age 61±14 years and 143 (53%) men. Diagnostic yield (55% vs 41%; odds ratio [OR], 1.73; 95% CI, 1.07 to 2.83; P=.026) and clinical utility (60% vs 40%; OR, 2.21; 95% CI, 1.36 to 3.63; P=.001) were higher for the cryobiopsy group, and the association remained after control for prebiopsy clinical impressions (OR, 2.21; 95% CI, 1.22 to 4.08; P=.010 and OR, 3.23; 95% CI, 1.76 to 6.10; P<.001, respectively). However, pneumothorax (5.4% vs 0.7%; P=.022) and serious bleeding (7.1% vs 0%; P=.001) rates were higher for the cryobiopsy group. Thirty-day mortality was 1.6% in the cryobiopsy group vs 0% for the forceps biopsy group (P=.20). CONCLUSION: Bronchoscopic cryobiopsy revealed higher diagnostic yield and clinical utility than did forceps biopsy. However, procedure-related complications were higher in the cryobiopsy group. The choice of bronchoscopic biopsy procedure for patients with DPLD depends on the clinicalradiologic context.

ROCK inhibitor increases proacinar cells in adult salivary gland organoids.

Salisphere-derived adult epithelial cells have been used to improve saliva production of irradiated mouse salivary glands. Importantly, optimization of the cellular composition of salispheres could improve their regenerative capabilities. The Rho Kinase (ROCK) inhibitor, Y27632, has been used to increase the proliferation and reduce apoptosis of progenitor cells grown in vitro. In this study, we investigated whether Y27632 could be used to improve expansion of adult submandibular salivary epithelial progenitor cells or to affect their differentiation potential in different media contexts. Application of Y27632 in medium used previously to grow salispheres promoted expansion of Kit+ and Mist1+ cells, while in simple serum-containing medium Y27632 increased the number of cells that expressed the K5 basal progenitor marker. Salispheres derived from Mist1CreERT2; R26TdTomato mice grown in salisphere media with Y27632 included Mist1-derived cells. When these salispheres were incorporated into 3D organoids, inclusion of Y27632 in the salisphere stage increased the contribution of Mist1-derived cells expressing the proacinar/acinar marker, Aquaporin 5 (AQP5), in response to FGF2-dependent mesenchymal signals. Optimization of the cellular composition of salispheres and organoids can be used to improve the application of adult salivary progenitor cells in regenerative medicine strategies.

Peripheral blood telomere alterations in ground glass opacity (GGO) lesions may suggest malignancy.

A ground glass opacity (GGO) lung lesion may represent early stage adenocarcinoma, which has an excellent prognosis upon prompt surgical resection. However, GGO lesions have broad differential diagnoses, including both benign and malignant lesions. Our objective was to study telomere length and telomerase activity in patients with suspected lung cancer in which GGO was the predominant radiographic feature. Knowledge of telomere biology may help distinguish malignant from benign radiographic lesions and guide risk assessment of these lesions. Peripheral blood samples were taken from 22 patients with suspected adenocarcinoma with the GGO radiographic presentation. Multidisciplinary discussion confirmed the need for surgery in all cases. We used an age and gender-matched group without known lung disease as a control. Telomere length and aggregates were assessed by quantitative fluorescence in situ hybridization (QFISH) and quantitative PCR. Cell senescence was evaluated by senescence-associated heterochromatin foci. Subjects with GGO lesions had a higher percentage of lymphocytes with shorter telomeres (Q-FISH, P = 0.003). Furthermore, relative telomere length was also reduced among the GGO cases (qPCR, P < 0.05). Increased senescence was observed in the GGO group compared to controls (P < 0.001), with significant correlation between the senescence-associated heterochromatin foci and aggregate formation (r = -0.7 and r = -0.44 for cases and controls, respectively). In conclusion, patients with resectable early adenocarcinoma demonstrate abnormal telomere length and cell senescence in peripheral blood leukocytes compared to control subjects. Abnormal telomere biology in the peripheral blood may increase suspicion of early adenocarcinoma among patients with GGO lesions.

COPD Guidelines: A Review of the 2018 GOLD Report.

Global Strategy for the Diagnosis, Management, and Prevention of COPD 2018 is a consensus report published periodically since 2001 by an international panel of health professionals from respiratory medicine, socioeconomics, public health, and education comprising the Global Initiative for Chronic Obstructive Lung Disease (GOLD). The GOLD documents endeavor to incorporate latest evidence and expert consensus and are intended for use as "strategy documents" for implementation of effective care for chronic obstructive lung disease (COPD) on a global level. The GOLD 2018 report defines COPD as a "common, preventable and treatable disease that is characterized by persistent respiratory symptoms and airflow limitation that is due to airway and/or alveolar abnormalities, usually caused by significant exposure to noxious particles or gases," with the criteria of "persistent respiratory symptoms" being a new and controversial inclusion since 2017. With the availability of newer pharmacotherapy options, treatment recommendations are made on the basis of a review of the latest literature and directed by symptom burden and health care utilization. Apart from the change in definition, a major shift in the recommendations is the exclusion of severity of airflow limitation as one of the major factors in guiding therapy. We review the salient features of the GOLD 2018 document and provide commentary on features that merit further discussion based on our clinical experience and practice as well as literature review current as of February 2018.

Unexplained cough: it is time to rule out Sjogren's syndrome.

Sjogren's syndrome is associated with chronic cough, but sicca symptoms are missing from cough evaluation guidelines. We evaluated patients with unexplained cough for undiagnosed Sjogren's syndrome. Patients referred to our pulmonary clinic (Sheba Medical Center, 2009 to 2012) with unexplained cough and concomitant dry eyes were selected for evaluation. Unexplained cough was defined as chronic cough of unknown etiology despite algorithm-based evaluation and treatment. Patients were evaluated in a dedicated clinic by a pulmonologist, rheumatologist, and ophthalmologist specializing in autoimmune disease. Patients completed the Leicester Cough Questionnaire, spirometry, antibody testing for anti Ro/La, ophthalmologic examination with visual acuity, eyelid, ocular surface fluorescein staining, tear break-up time and Schirmer's test, full slit lamp, and fundus examinations. Four-year follow-up was conducted by telephone questionnaire. We identified 24 patients among which 22 (21 females) agreed for evaluation. Eight patients (36%), seven initially, and one during follow-up were diagnosed with Sjogren's syndrome (SS) (six secondary and two primary SS). At 4-year follow-up, cough tended to persist and improve in only 37% with SS. These include 2 (Scl and RA) who received rituximab and 1 (stage 1 sarcoidosis) with spontaneous improvement. In contrast, cough improved in most (64%) patients without SS; the majority (eight/nine) report intensified disease-specific treatment (five allergic and three GERD). We describe patients in whom unexplained chronic cough was associated with dry eyes. Focused workup revealed undiagnosed Sjogren's syndrome in 36%. Dry eyes, with or without SS, is under-recognized and should be added to diagnostic algorithms for unexplained cough.

Rheumatological Assessment Is Important for Interstitial Lung Disease Diagnosis.

OBJECTIVE: Interstitial lung diseases (ILD) form a diverse group of parenchymal lung disorders. Currently, a multidisciplinary team (MDT) including pulmonologists, radiologists, and pathologists is the gold standard for ILD diagnosis. Recently, additional subtypes of connective tissue disease (CTD)-ILD with autoimmune features were defined, making the rheumatological assessment increasingly important. We aimed to assess the effect of adding a rheumatologist to the MDT for routine rheumatology assessment. METHODS: A prospective study that assessed newly diagnosed ILD patients by 2 parallel blinded arms; all patients were evaluated by both MDT (e.g., history, physical examination, blood tests, pulmonary function tests, and biopsies, if needed) and a rheumatologist (e.g., history, physical examination, blood and serological tests). RESULTS: Sixty patients were assessed with the mean age of 67.3 ± 12 years, 55% male, and 28% smokers. The rheumatological assessment reclassified 21% of the idiopathic pulmonary fibrosis as CTD. Moreover, the number of CTD-ILD with autoimmune features was increased by 77%. These included antineutrophil cytoplasmic antibody-associated vasculitis, antisynthetase syndrome, and IgG4-related ILD. Retrospectively, rheumatological evaluation could have saved 7 bronchoscopies and 1 surgical biopsy. CONCLUSION: Adding routine rheumatology assessments could significantly increase diagnostic accuracy and reduce invasive procedures.

A Novel Impedance Biosensor for Measurement of Trans-Epithelial Resistance in Cells Cultured on Nanofiber Scaffolds.

Nanofibrous scaffolds provide high surface area for cell attachment, and resemble the structure of the collagen fibers which naturally occur in the basement membrane and extracellular matrix. A label free and non-destructive method of assessing the interaction of cell tissue and scaffolds aids in the ability to discern the effective quality and magnitude of any scaffold modifications. Impedance cell spectroscopy is a biosensing method that employs a functional approach to assessing the cell monolayer. The electrical impedance barrier function of a cell monolayer represents the level of restriction to diffusion of charged species between all adjacent cells across an entire contiguous cellular monolayer. The impedance signals from many individual paracellular pathways contribute to the bulk measurement of the whole monolayer barrier function. However, the scaffold substrate must be entirely porous in order to be used with electrochemical cell impedance spectroscopy (ECIS) and cells must be closely situated to the electrodes. For purposes of evaluating cell-scaffold constructs for tissue engineering, non-invasive evaluation of cell properties while seeded on scaffolds is critical. A Transwell-type assay makes a measurement across a semi-permeable membrane, using electrodes placed on opposing sides of the membrane immersed in fluid. It was found that by suspending a nanofiber scaffold across a Transwell aperture, it is possible to integrate a fully functional nanofiber tissue scaffold with the ECIS Transwell apparatus. Salivary epithelial cells were grown on the nanofiber scaffolds and tight junction formation was evaluated using ECIS measurements in parallel with immunostaining and confocal imaging. The trans-epithelial resistance increased coordinate with cell coverage, culminating with a cell monolayer, at which point the tight junction proteins assemble and strengthen, reaching the peak signal. These studies demonstrate that ECIS can be used to evaluate tight junction formation in cells grown on nanofiber scaffolds and on effects of scaffold conditions on cells, thus providing useful biological feedback to inform superior scaffold designs.