Organoids are self‐organizing 3D structures grown from stem cells that recapitulate essential aspects of organ structure and function. Here, we describe a method to establish long‐term‐expanding human airway organoids from broncho‐alveolar resections or lavage material. The pseudostratified airway organoids consist of basal cells, functional multi‐ciliated cells, mucus‐producing secretory cells, and CC10‐secreting club cells. Airway organoids derived from cystic fibrosis (CF) patients allow assessment of CFTR function in an organoid swelling assay. Organoids established from lung cancer resections and metastasis biopsies retain tumor histopathology as well as cancer gene mutations and are amenable to drug screening. Respiratory syncytial virus (RSV) infection recapitulates central disease features, dramatically increases organoid cell motility via the non‐structural viral NS2 protein, and preferentially recruits neutrophils upon co‐culturing. We conclude that human airway organoids represent versatile models for the in vitro study of hereditary, malignant, and infectious pulmonary disease.

Background-Asynchronous electrical activation, induced by ventricular pacing, causes regional differences in workload, which is lower in early-than in late-activated regions. Because the myocardium usually adapts its mass and structure to altered workload, we investigated whether ventricular pacing leads to inhomogeneous hypertrophy and whether such adaptation, if any, affects global left ventricular (LV) pump function. Methods and Results-Eight dogs were paced at physiological heart rate for 6 months (AV sequential, AV interval 25 ms, ventricular electrode at the base of the LV free wall). Five dogs were sham operated and served as controls. Ventricular pacing increased QRS duration from 47.2Ϯ10.6 to 113Ϯ16.5 ms acutely and to 133.8Ϯ25.2 ms after 6 months. Two-dimensional echocardiographic measurements showed that LV cavity and wall volume increased significantly by 27Ϯ15% and 15Ϯ17%, respectively. The early-activated LV free wall became significantly (17Ϯ17%) thinner, whereas the late-activated septum thickened significantly (23Ϯ12%). Calculated sector volume did not change in the LV free wall but increased significantly in the septum by 39Ϯ13%. In paced animals, cardiomyocyte diameter was significantly (18Ϯ7%) larger in septum than in LV free wall, whereas myocardial collagen fraction was unchanged in both areas. LV pressure-volume analysis showed that ventricular pacing reduced LV function to a similar extent after 15 minutes and 6 months of pacing. Conclusions-Asynchronous activation induces asymmetrical hypertrophy and LV dilatation. Cardiac pump function is not affected by the adaptational processes. These data indicate that local cardiac load regulates local cardiac mass of both myocytes and collagen. (Circulation. 1998;98:588-595.)

Mutations in SFTPC are a frequent cause of FPF in adult patients in our cohort. Nonclassifiable radiological patterns with cystic changes and histopathological patterns of usual interstitial pneumonia are characteristics of adult SFTPC mutation carriers.

Various kinds of abnormal, asynchronous electric activation of the left ventricle (LV) decrease mechanical load in early versus late activated regions of the ventricular wall. Because myocardium usually adapts its mass to changes in workload, we investigated by echocardiography whether regional differences in wall thickness are present in two kinds of asynchronous electric activation of different origin and conduction pathway: epicardial ventricular pacing in dogs and left bundle branch block (LBBB) in patients. In six dogs, 3 months of epicardial LV pacing at physiologic heart rates decreased the thickness of the early activated anterior wall by 20.5 +/- 8.1% without significantly changing LV cavity area and septal thickness. In a retrospective study of 228 LBBB patients, the early activated septum was significantly thinner than the late activated posterior wall. The asymmetry most pronounced was as large as 10% in 28 patients with LBBB and paradoxic septal motion. No difference in regional wall thickness was present in 154 control patients. In conclusion, chronic asynchronous electric activation in the heart induces redistribution of cardiac mass. This redistribution occurs in hearts, which differ in impulse conduction pathway, disease, and species and is characterized by thinning of early versus late activated myocardium.

Diffusion tensor imaging (DTI) is frequently applied to characterize the microscopic geometrical properties of tissue. To establish whether and how diffusion MRI responds to transient ischemia of skeletal muscle, we studied the effects of ischemia and reperfusion using DTI and T 2 -weighted MRI before and during ischemia and up to 24 hr after reperfusion. Ischemia was induced by 50 min of hindlimb occlusion with or without dorsal flexor stimulation. During ischemia the apparent diffusion coefficient (ADC) tended to decrease (up to 15%), whereas the fractional anisotropy (FA) and T 2 showed a varied response depending on the protocol and muscle type. During reperfusion the ADC and T 2 initially increased and subsequently renormalized for the occlusion protocol. For the occlusion plus stimulation (OS) protocol, the FA was decreased by 13% and the ADC and T 2 were increased by 20% and 57%, respectively, after 24 hr in the stimulated muscle complex. In the latter tissue the three DTI eigenvalues gradually increased upon reperfusion. The smallest eigenvalue (

Telomere maintenance dysfunction has been implicated in the pathogenesis of Idiopathic Pulmonary Fibrosis (IPF). However, the mechanism of how telomere length is related to fibrosis in the lungs is unknown. Surgical lung biopsies of IPF patients typically show a heterogeneous pattern of non-fibrotic and fibrotic areas. Therefore, telomere length (TL) in both lung areas of patients with IPF and familial interstitial pneumonia was compared, specifically in alveolar type 2 (AT2) cells.Fluorescent in situ hybridization was used to determine TL in non-fibrotic and fibrotic areas of 35 subjects. Monochrome multiplex quantitative polymerase chain reaction (MMqPCR) was used for 51 whole lung biopsies and blood TL measurements.For sporadic IPF subjects, AT2 cell TL in non-fibrotic areas was 56% longer than in fibrotic areas. No such difference was observed in the surrounding lung cells. In subjects carrying a telomerase reverse transcriptase (TERT) mutation, AT2 cell TL was significantly shorter than in sporadic subjects. However, no difference in surrounding cell TL was observed between these subject groups. Finally, using biopsy MMqPCR TL measurements, it was determined that IPF subjects with shortest lung TL had a significantly worse survival than patients with long TL.This study shows that shortening of telomeres critically affects AT2 cells in fibrotic areas, implying TL as a cause of fibrogenesis. Furthermore, short lung telomere length is associated with decreased survival.

Background-Despite improvement in short-term patient survival after heart transplantation (HTx), long-term survival rates have not improved much, mainly because of cardiac allograft vasculopathy (CAV). Cytokines and chemokines are considered to play an important role in CAV development. Interleukin-4 and interleukin-10 were expressed at the same level in both HTx groups and references. In HTxϩCAV, all CϩCR, but especially the T-helper 1 (TH1) CϩCR, were more abundant than in the HTxϪCAV and references. However, TH2 CCR4 expression did not differ significantly between both HTx groups. Conclusions-In coronary arteries with CAV, most T cells are CD4 ϩ and express human leukocyte antigen DR. These activated TH cells are mainly memory TH1 cells on the basis of their CϩCR profile and cytokine expression. Methods and Results-We

Pulmonary carcinoids are neuroendocrine tumors histopathologically subclassified into typical (TC; no necrosis, <2 mitoses per 2 mm) and atypical (AC; necrosis or 2 to 10 mitoses per 2 mm). The reproducibility of lung carcinoid classification, however, has not been extensively studied and may be hampered by the presence of pyknotic apoptosis mimicking mitotic figures. Furthermore, prediction of prognosis based on histopathology varies, especially for ACs. We examined the presence of interobserver variation between 5 experienced pulmonary pathologists who reviewed 123 originally diagnosed pulmonary carcinoid cases. The tumors were subsequently redistributed over 3 groups: unanimously classified cases, consensus cases (4/5 pathologists rendered identical diagnosis), and disagreement cases (divergent diagnosis by ≥2 assessors). κ-values were calculated, and results were correlated with clinical follow-up and molecular data. When focusing on the 114/123 cases unanimously classified as pulmonary carcinoids, the interobserver agreement was only fair (κ=0.32). Of these 114 cases, 55% were unanimously classified, 25% reached consensus classification, and for 19% there was no consensus. ACs were significantly more often in the latter category (P=0.00038). The designation of TCs and ACs by ≥3 assessors was not associated with prognosis (P=0.11). However, when disagreement cases were allocated on the basis of Ki-67 proliferative index (<5%; ≥5%) or nuclear orthopedia homeobox immunostaining (+; -), correlation with prognosis improved significantly (P=0.00040 and 0.0024, respectively). In conclusion, there is a considerable interobserver variation in the histopathologic classification of lung carcinoids, in particular concerning ACs. Additional immunomarkers such as Ki-67 or orthopedia homeobox may improve classification and prediction of prognosis.