Therapeutic limb hypothermia for the treatment of traumatic acute limb ischemia.

Acute limb ischaemia (ALI) is an emergent clinical condition that strains pre-hospital resources and impacts healthcare costs and patient quality of life. Hypothermia has long been used in clinical and research settings to mitigate ischaemic damage in tissues, but prompt reperfusion is needed to prevent loss of limb or function from ALI. To address the unmet need for pre-hospital intervention of threatened limbs awaiting definitive specialty care, we have focused on controlled application of hypothermia. Over years of animal experiments, phantom limb creation, and materials selection, we conceptualised and created a portable limb-cooling device that can be used alone or combined with a traditional tourniquet or resuscitative endovascular balloon occlusion of the aorta. Here, we describe our process of building and testing the device, from computer simulation through animal-limb metabolic studies, to prototype testing.

Black dots: High-yield traction force microscopy reveals structural factors contributing to platelet forces.

Measuring the traction forces produced by cells provides insight into their behavior and physiological function. Here, we developed a technique (dubbed 'black dots') that microcontact prints a fluorescent micropattern onto a flexible substrate to measure cellular traction forces without constraining cell shape or needing to detach the cells. To demonstrate our technique, we assessed human platelets, which can generate a large range of forces within a population. We find platelets that exert more force have more spread area, are more circular, and have more uniformly distributed F-actin filaments. As a result of the high yield of data obtainable by this technique, we were able to evaluate multivariate mixed effects models with interaction terms and conduct a clustering analysis to identify clusters within our data. These statistical techniques demonstrated a complex relationship between spread area, circularity, F-actin dispersion, and platelet force, including cooperative effects that significantly associate with platelet traction forces. STATEMENT OF SIGNIFICANCE: Cells produce contractile forces during division, migration, or wound healing. Measuring cellular forces provides insight into their health, behavior, and function. We developed a technique that calculates cellular forces by seeding cells onto a pattern and quantifying how much each cell displaces the pattern. This technique is capable of measuring hundreds of cells without needing to detach them. Using this technique to evaluate human platelets, we find that platelets exerting more force tend to have more spread area, are more circular in shape, and have more uniformly distributed cytoskeletal filaments. Due to our high yield of data, we were able to apply statistical techniques that revealed combinatorial effects between these factors.

More than Just the Number of Brain Metastases: Evaluating the Impact of Brain Metastasis Location and Relative Volume on Overall Survival After Stereotactic Radiosurgery.

OBJECTIVE: Most evidence describing outcomes of patients with brain metastases is based on number of brain metastases, rather than location or volume. We evaluated the impact of tumor location and relative volume on overall survival (OS) among a large cohort of patients treated with stereotactic radiosurgery. METHODS: Clinical, radiographic, and dosimetric data were collected on patients treated with first (if multiple) stereotactic radiosurgery for brain metastases. Multivariate analyses were performed to investigate the impact of brain metastasis relative location and volume on OS after stereotactic radiosurgery. RESULTS: Analysis included 300 patients with 817 tumors (116 patients with single brain metastasis). The most common tumor locations were supratentorial (75% of tumors), cerebellar (19%), and brainstem (5%). Median tumor volume was 0.4 mL (range, 0.003-65.0 mL). Tumor-specific factors associated with inferior OS included brainstem location versus both supratentorial and cerebellum locations for particular assumed values of cube root tumor volume (P < 0.001 for each) and increasing total supratentorial tumor volume (P = 0.004). Patients with supratentorial tumors and cerebellar tumors demonstrated similar OS, and cube root total tumor volume within the cerebellum and brainstem did not predict for OS. CONCLUSIONS: The presence of brainstem metastases and cumulative supratentorial tumor volume are adverse features that result in inferior survival. These results can be used to inform patient prognosis and future clinical trial design.

The measurand problem in breath alcohol testing.

Proper interpretation of forensic measurements can be critical to the administration of justice. Breath alcohol testing is commonly relied upon to measure the concentration of alcohol in breath or, indirectly, in blood. The concentration sought constitutes the "quantity intended to be measured," referred to as the measurand. Although breath tests always probe the same physical quantity, their measurand is dictated by statute and varies between jurisdictions. Thus, identical numerical values obtained from tests in disparate jurisdictions may refer to different quantities and may not indicate the relevant statutory measurand. This can lead to misinterpretation of results, referred to as the "measurand problem." We first illustrate the concept of the measurand. Thereafter, the measurand problem is illustrated through application of Hlastala's breath test paradigm and Gullberg's work on breath test uncertainty. It is shown that where the measurand is not properly accounted for, conclusions based upon breath test evidence are undermined.

Targeting FoxO1 with AS1842856 suppresses adipogenesis.

Hyperplasia (i.e., increased adipogenesis) contributes to excess adiposity, the hallmark of obesity that can trigger metabolic complications. As FoxO1 has been implicated in adipogenic regulation, we investigated the kinetics of FoxO1 activation during adipocyte differentiation, and tested the effects of FoxO1 antagonist (AS1842856) on adipogenesis. We found for the first time that the kinetics of FoxO1 activation follows a series of sigmoid curves, and reveals the phases relevant to clonal expansion, cell cycle arrest, and the regulation of PPARγ, adiponectin, and mitochondrial proteins (complexes I and III). In addition, multiple activation-inactivation transitions exist in the stage of terminal differentiation. Importantly, persistent inhibition of FoxO1 with AS1842856 almost completely suppressed adipocyte differentiation, while selective inhibition in specific stages had differential effects on adipogenesis. Our data present a new view of FoxO1 in adipogenic regulation, and suggest AS1842856 can be an anti-obesity agent that warrants further investigation.