Relative Lung Perfusion on Ventilation-Perfusion Scans After Double Lung Transplant.

BACKGROUND: Pulmonary blood flow can be assessed on ventilation-perfusion (VQ) scan with relative lung perfusion, with a 55% to 45% (or 10%) right-to-left differential considered normal. We hypothesized that wide perfusion differential on routine VQ studies at 3 mo posttransplant would be associated with an increased risk of death or retransplantation, chronic lung allograft (CLAD), and baseline lung allograft dysfunction. METHODS: We conducted a retrospective cohort study on all patients who underwent double-lung transplant in our program between 2005 and 2016, identifying patients with a wide perfusion differential of >10% on a 3-mo VQ scan. We used Kaplan-Meier estimates and proportional hazards models to assess the association between perfusion differential and time to death or retransplant and time to CLAD onset. We used correlation and linear regression to assess the relationship with lung function at time of scan and with baseline lung allograft dysfunction. RESULTS: Of 340 patients who met inclusion criteria, 169 (49%) had a relative perfusion differential of ≥ 10% on a 3-mo VQ scan. Patients with increased perfusion differential had increased risk of death or retransplantation ( P = 0.011) and CLAD onset ( P = 0.012) after adjustment for other radiographic/endoscopic abnormalities. Increased perfusion differential was associated with lower lung function at time of scan. CONCLUSIONS: Wide lung perfusion differential was common after lung transplant in our cohort and associated with increased risk of death, poor lung function, and CLAD onset. The nature of this abnormality and its use as a predictor of future risk warrant further investigation.

Tanezumab for chronic low back pain: a randomized, double-blind, placebo- and active-controlled, phase 3 study of efficacy and safety.

ABSTRACT: This randomized, double-blind, phase 3 study (56-week treatment; 24-week follow-up) assessed tanezumab in patients with chronic low back pain and history of inadequate response to standard-of-care analgesics (NCT02528253). Patients received placebo, subcutaneous tanezumab (5 or 10 mg every 8 weeks), or oral tramadol prolonged-release (100-300 mg/day). Primary endpoint was change in low back pain intensity (LBPI) at week 16 for tanezumab vs placebo. Key secondary endpoints were proportion of patients with ≥50% decrease in LBPI at week 16, change in Roland Morris Disability Questionnaire at week 16, and change in LBPI at week 2 for tanezumab vs placebo. Adverse events and joint safety were assessed through weeks 56 and 80, respectively. Tanezumab 10 mg met the primary endpoint by significantly improving LBPI at week 16 vs placebo; least squares (LS) mean (95% CI) difference = -0.40 (-0.76 to -0.04; P = 0.0281). Tanezumab 10 mg significantly improved all key secondary endpoints. Tanezumab 5 mg did not meet the primary endpoint (LS mean [95% CI] treatment difference vs placebo = -0.30 [-0.66 to 0.07; P = 0.1117]), preventing formal testing of key secondary endpoints for this dose. The proportion of patients with ≥50% improvement in LBPI at week 16 was 37.4% in the placebo group, 43.3% in the tanezumab 5 mg group (Odds ratio [95% CI] vs placebo = 1.28 [0.97 to 1.70; P = 0.0846]), and 46.3% in the tanezumab 10 mg group (Odds ratio [95% CI] vs placebo = 1.45 [1.09 to 1.91; P = 0.0101]). Prespecified joint safety events were more frequent with tanezumab 10 mg (2.6%) than tanezumab 5 mg (1.0%), tramadol (0.2%), or placebo (0%). Seven patients, all in the tanezumab 10 mg group (1.4%), underwent total joint replacement. In conclusion, tanezumab 10 mg significantly improved pain and function vs placebo in patients with difficult-to-treat chronic low back pain. Tanezumab was associated with a low rate of joint safety events, some requiring joint replacement.

Compartmentalized Culture of Perivascular Stroma and Endothelial Cells in a Microfluidic Model of the Human Endometrium.

The endometrium is the inner lining of the uterus. Following specific cyclic hormonal stimulation, endometrial stromal fibroblasts (stroma) and vascular endothelial cells exhibit morphological and biochemical changes to support embryo implantation and regulate vascular function, respectively. Herein, we integrated a resin-based porous membrane in a dual chamber microfluidic device in polydimethylsiloxane that allows long term in vitro co-culture of human endometrial stromal and endothelial cells. This transparent, 2-µm porous membrane separates the two chambers, allows for the diffusion of small molecules and enables high resolution bright field and fluorescent imaging. Within our primary human co-culture model of stromal and endothelial cells, we simulated the temporal hormone changes occurring during an idealized 28-day menstrual cycle. We observed the successful differentiation of stroma into functional decidual cells, determined by morphology as well as biochemically as measured by increased production of prolactin. By controlling the microfluidic properties of the device, we additionally found that shear stress forces promoted cytoskeleton alignment and tight junction formation in the endothelial layer. Finally, we demonstrated that the endometrial perivascular stroma model was sustainable for up to 4 weeks, remained sensitive to steroids and is suitable for quantitative biochemical analysis. Future utilization of this device will allow the direct evaluation of paracrine and endocrine crosstalk between these two cell types as well as studies of immunological events associated with normal vs. disease-related endometrial microenvironments.

Patterning of sharp cellular interfaces with a reconfigurable elastic substrate.

Micropatterned cocultures are a useful experimental tool for the study of cell-cell interactions. Patterning methods often rely on sequential seeding of different cell types or removal of a barrier separating two populations, but it is difficult to pattern sharp interfaces between pure populations with low cross-contamination when using these approaches. Patterning by the use of reconfigurable substrates can overcome these limitations, but such methods can be costly and challenging to employ in a typical biology laboratory. Here, we describe a low-cost and simple-to-use reconfigurable substrate comprised of a transparent elastic material that is partially cut to form a slit that opens when the device is stretched. The slit seals back up when released, allowing two initially separate, adherent cell populations to be brought together to form a contact interface. Fluorescent imaging of patterned cocultures demonstrates the early establishment of a sharp cellular interface. As a proof of principle, we demonstrate the use of this device to study competition at the interface of two stem cell populations.

Visualizing cell proximity with genetically encoded bioluminescent reporters.

Cell-cell interactions underlie diverse physiological processes ranging from immune function to cell migration. Dysregulated cellular crosstalk also potentiates numerous pathologies, including infections and metastases. Despite their ubiquity in organismal biology, cell-cell interactions are difficult to examine in tissues and whole animals without invasive procedures. Here, we report a strategy to noninvasively image cell proximity using engineered bioluminescent probes. These tools comprise "split" fragments of Gaussia luciferase (Gluc) fused to the leucine zipper domains of Fos and Jun. When cells secreting the fragments draw near one another, Fos and Jun drive the assembly of functional, light-emitting Gluc. Photon production thus provides a readout on the distance between two cell types. We used the split fragments to visualize cell-cell interactions over time in vitro and in macroscopic models of cell migration. Further application of these tools in live organisms will refine our understanding of cell contacts relevant to basic biology and disease.

Decline in varicella-zoster virus (VZV)-specific cell-mediated immunity with increasing age and boosting with a high-dose VZV vaccine.

The safety and immunogenecity of a booster dose of live attenuated varicella-zoster virus (VZV) vaccine was evaluated in 196 healthy subjects, >or=60 years old, who had already received a VZV vaccine >5 years before. This repeat booster dose was well tolerated. Cell-mediated immunity (CMI) to VZV was measured by an interferon-gamma (IFN-gamma) enzyme-linked immunosorbent spot-forming cell (ELISPOT) assay and a limiting dilution responder cell frequency (RCF) assay. Prevaccination responses decreased as a function of increasing age but were detectable in all subjects by use of the IFN-gamma ELISPOT assay. In most subjects, VZV-specific CMI was increased at 6 weeks postvaccination. The magnitude of the vaccine-induced IFN-gamma ELISPOT response was inversely related to prevaccination values. Although there was a significant correlation between the IFN-gamma ELISPOT and RCF assays, the ELISPOT assay had greater sensitivity and a wider dynamic range. A live attenuated VZV vaccine is safe and immunogenic in an elderly population, and the vaccine-induced immunity may be monitored by the IFN-gamma ELISPOT assay.