Delayed and deficient dermal maturation in mice lacking the CXCR3 ELR-negative CXC chemokine receptor

Replacement of wounded skin requires the initially florid cellular response to abate and even regress as the dermal layer returns to a relatively paucicellular state. The signals that direct this "stop and return" process have yet to be deciphered. CXCR3 chemokine receptor and its ligand CXCL11/IP-9/I-TAC are expressed by basal keratinocytes and CXCL10/IP-10 by keratinocytes and endothelial cells during wound healing in mice and humans. In vitro, these ligands limit motility in dermal fibroblasts and endothelial cells. To examine whether this signaling pathway contributes to wound healing in vivo, full-thickness excisional wounds were created on CXCR3 wild-type (+/+) or knockout (-/-) mice. Even at 90 days, long after wound closure, wounds in the CXCR3(-/-) mice remained hypercellular and presented immature matrix components. The CXCR3(-/-) mice also presented poor remodeling and reorganization of collagen, which resulted in a weakened healed dermis. This in vivo model substantiates our in vitro findings that CXCR3 signaling is necessary for inhibition of fibroblast and endothelial cell migration and subsequent redifferentiation of the fibroblasts to a contractile state. These studies establish a pathophysiologic role for CXCR3 and its ligand during wound repair.     

Mathematical model of network dynamics governing mouse sleep-wake behavior

Recent work in experimental neurophysiology has identified distinct neuronal populations in the rodent brain stem and hypothalamus that selectively promote wake and sleep. Mutual inhibition between these cell groups has suggested the conceptual model of a sleep-wake switch that controls transitions between wake and sleep while minimizing time spent in intermediate states. By combining wake- and sleep-active populations with populations governing transitions between different stages of sleep, a "sleep-wake network" of neuronal populations may be defined. To better understand the dynamics inherent in this network, we created a model sleep-wake network composed of coupled relaxation oscillation equations. Mathematical analysis of the deterministic model provides insight into the dynamics underlying state transitions and predicts mechanisms for each transition type. With the addition of noise, the simulated sleep-wake behavior generated by the model reproduces many qualitative and quantitative features of mouse sleep-wake behavior. In particular, the existence of simulated brief awakenings is a unique feature of the model. In addition to capturing the experimentally observed qualitative difference between brief and sustained wake bouts, the model suggests distinct network mechanisms for the two types of wakefulness. Because circadian and other factors alter the fine architecture of sleep-wake behavior, this model provides a novel framework to explore dynamical principles that may underlie normal and pathologic sleep-wake physiology.     

Smoking, fibrinogen and cancer mortality

Associations of race, smoking history and fibrinogen levels with cancer mortality were investigated prospectively using the ARIC study. Our cohort consisted of 14,320 participants aged 45-64 at baseline. In an adjusted Cox regression, black current heavy smokers (> or = 15 cigarettes per day) demonstrated higher risk of respiratory/intrathoracic organ cancer mortality than nonblack current heavy smokers. Black former heavy smokers were also found to be at an increased risk of respiratory/intrathoracic organ cancer mortality when compared to nonblack former heavy smokers. Elevated fibrinogen levels were associated with an increased risk of respiratory/intrathoracic organ cancer mortality. Compared to fibrinogen < 259 mg/dl, fibrinogen 294-335 mg/dl had an adjusted hazard ratio of 3.68 (95% CI: 1.80-7.55), and fibrinogen > or = 336 mg/dl had an adjusted hazard ratio of 3.78 (95% CI: 1.84-7.75). Fibrinogen was also a predictor of other types of cancer mortality among black participants, but not among nonblack participants. For 10 race/smoking history categories, fibrinogen levels ranged from a mean of 287 mg/dl for nonblack former light smokers to a mean of 338 mg/dl for black current heavy smokers. Smokers had higher fibrinogen levels than nonsmokers, and black smokers had higher fibrinogen levels than nonblack smokers. Smoking carries high risks of cancer mortality for African Americans. A factor that needs to be considered in the overall assessment of risk is fibrinogen level, which has been linked to angiogenesis and metastases of tumors.     

Digital autoradiography using room temperature CCD and CMOS imaging technology

CCD (charged coupled device) and CMOS imaging technologies can be applied to thin tissue autoradiography as potential imaging alternatives to using conventional film. In this work, we compare two particular devices: a CCD operating in slow scan mode and a CMOS-based active pixel sensor, operating at near video rates. Both imaging sensors have been operated at room temperature using direct irradiation with images produced from calibrated microscales and radiolabelled tissue samples. We also compare these digital image sensor technologies with the use of conventional film. We show comparative results obtained with (14)C calibrated microscales and (35)S radiolabelled tissue sections. We also present the first results of (3)H images produced under direct irradiation of a CCD sensor operating at room temperature. Compared to film, silicon-based imaging technologies exhibit enhanced sensitivity, dynamic range and linearity.     

How Sensitive Are Transdermal Transport Predictions by Microscopic Stratum Corneum Models to Geometric and Transport Parameter Input?

While predictive models of transdermal transport have the potential to reduce human and animal testing, microscopic stratum corneum (SC) model output is highly dependent on idealized SC geometry, transport pathway (transcellular vs. intercellular), and penetrant transport parameters (e.g., compound diffusivity in lipids). Most microscopic models are limited to a simple rectangular brick-and-mortar SC geometry and do not account for variability across delivery sites, hydration levels, and populations. In addition, these models rely on transport parameters obtained from pure theory, parameter fitting to match in vivo experiments, and time-intensive diffusion experiments for each compound. In this work, we develop a microscopic finite element model that allows us to probe model sensitivity to variations in geometry, transport pathway, and hydration level. Given the dearth of experimentally-validated transport data and the wide range in theoretically-predicted transport parameters, we examine the model's response to a variety of transport parameters reported in the literature. Results show that model predictions are strongly dependent on all aforementioned variations, resulting in order-of-magnitude differences in lag times and permeabilities for distinct structure, hydration, and parameter combinations. This work demonstrates that universally predictive models cannot fully succeed without employing experimentally verified transport parameters and individualized SC structures.     

Coformulation of Broadly Neutralizing Antibodies 3BNC117 and PGT121: Analytical Challenges During Preformulation Characterization and Storage Stability Studies

In this study, we investigated analytical challenges associated with the formulation of 2 anti-HIV broadly neutralizing antibodies (bnAbs), 3BNC117 and PGT121, both separately at 100 mg/mL and together at 50 mg/mL each. The bnAb formulations were characterized for relative solubility and conformational stability followed by accelerated and real-time stability studies. Although the bnAbs were stable during 4°C storage, incubation at 40°C differentiated their stability profiles. Specific concentration-dependent aggregation rates at 30°C and 40°C were measured by size exclusion chromatography for the individual bnAbs with the mixture showing intermediate behavior. Interestingly, although the relative ratio of the 2 bnAbs remained constant at 4°C, the ratio of 3BNC117 to PGT121 increased in the dimer that formed during storage at 40°C. A mass spectrometry-based multiattribute method, identified and quantified differences in modifications of the Fab regions for each bnAb within the mixture including clipping, oxidation, deamidation, and isomerization sites. Each bnAb showed slight differences in the levels and sites of lysine residue glycations. Together, these data demonstrate the ability to differentiate degradation products from individual antibodies within the bnAb mixture, and that degradation rates are influenced not only by the individual bnAb concentrations but also by the mixture concentration.     

Clean intermittent catheterization rates after initial and subsequent treatments with onabotulinumtoxinA for non-neurogenic overactive bladder in real-world clinical settings

Objective: Previous randomized controlled trials have reported a 6.1–6.9% incidence of clean intermittent catheterization (CIC) following treatment with onabotulinumtoxinA in non-neurogenic overactive bladder (OAB) patients who were inadequately managed by ≥1 anticholinergic. A multi-center retrospective chart review assessed the real-world rate of voiding dysfunction requiring catheterization.

Methods: Patients received onabotulinumtoxinA 100?U (approved dose) administered by experienced injectors between January 2013 and June 2015. Patients using CIC or an indwelling catheter for ≥24?hours for voiding dysfunction prior to onabotulinumtoxinA injections were excluded. The primary outcome was post-treatment CIC (lasting >24?hours; per individual physician’s clinical judgment considering patient’s voiding symptoms, post-void residual [PVR] urine volumes and patient bother). Potential baseline predictors of CIC (history of pelvic prolapse, cystocele, diabetes, PVR urine volume and age) were assessed using multivariable logistic regression.

Results: Overall, 299 patients received their first treatment with onabotulinumtoxinA 100?U. Mean age was 66.4 years; 98.3% were female. The incidence of CIC was 2.7% in the total study population after the first treatment with onabotulinumtoxinA. The de novo CIC rate in treatments 2 and 3 combined was similarly low (3.2%). None of the evaluated baseline characteristics were significant predictors of CIC initiation due to the low CIC incidence.

Conclusions: This real-world study of non-neurogenic OAB patients treated with onabotulinumtoxinA suggests that the CIC rate is lower than the rates reported in previous studies. There were no significant correlations between baseline predictors and CIC initiation, although statistical significance may not have been reached because of the low incidence of CIC.