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Burke AR, Singh RN, Carroll DL, Wood JC, D'Agostino RB, Ajayan PM, Torti FM, Torti SV.
Biomaterials. 2012 Apr ;33(10):2961-70.
PMID: 22245557
Breast tumors contain a small population of tumor initiating stem-like cells, termed breast cancer stem cells (BCSCs). These cells, which are refractory to chemotherapy and radiotherapy, are thought to persist following treatment and drive tumor recurrence. We examined whether BCSCs are similarly resistant to hyperthermic therapy, and whether nanoparticles could be used to overcome this resistance. Using a model of triple-negative breast cancer stem cells, we show that BCSCs are markedly resistant to traditional hyperthermia and become enriched in the surviving cell population following treatment. In contrast, BCSCs are sensitive to nanotube-mediated thermal treatment and lose their long-term proliferative capacity after nanotube-mediated thermal therapy. Moreover, use of this therapy in vivo promotes complete tumor regression and long-term survival of mice bearing cancer stem cell-driven breast tumors. Mechanistically, nanotube thermal therapy promotes rapid membrane permeabilization and necrosis of BCSCs. These data suggest that nanotube-mediated thermal treatment can simultaneously eliminate both the differentiated cells that constitute the bulk of a tumor and the BCSCs that drive tumor growth and recurrence.
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Barnes LE, Levender MM, Fleischer AB, Feldman SR.
Dermatol Clin. 2012 Apr ;30(2):293-300.
PMID: 22284143
Acne vulgaris affects most adolescents and two-thirds of adults and is associated with substantial psychosocial burden. Health-related quality of life (HRQOL) for patients with acne is an important factor of patient care, and several dermatologic and acne-specific measures have been created to assist in acne research, management, and care. This review describes several skin disease and acne-specific HRQOL measures and their applications in clinical care or research. The ideal HRQOL measure for the management of patients with acne is a concise questionnaire that places minimal burden on respondents and allows physicians to track improvement in HRQOL with successful treatment.
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Nagarajan D, Melo T, Deng Z, Almeida C, Zhao W.
Free Radic Biol Med. 2012 Mar 15;52(6):983-92.
PMID: 22198183
Radiotherapy is one of the major treatment regimes for thoracic malignancies, but can lead to severe lung complications including pneumonitis and fibrosis. Recent studies suggest that epithelial-to-mesenchymal transition (EMT) plays an important role in tissue injury leading to organ fibrosis. To investigate whether radiation can induce EMT in lung epithelial cells and also to understand the potential mechanism(s) associated with this change, rat alveolar type II lung epithelial RLE-6TN cells were irradiated with 8Gy of (137)Cs γ-rays. Western blot and immunofluorescence analyses revealed a time-dependent decrease in E-cadherin with a concomitant increase in α-smooth muscle actin (α-SMA) and vimentin after radiation, suggesting that the epithelial cells acquired a mesenchymal-like morphology. Protein levels and nuclear translocation of Snail, the key inducer of EMT, were significantly elevated in the irradiated cells. Radiation also induced a time-dependent inactivation of glycogen synthase kinase-3β (GSK3β), an endogenous inhibitor of Snail. A marked increase in phosphorylation of ERK1/2, but not JNK or p38, was observed in irradiated RLE-6TN cells. Silencing ERK1/2 using siRNAs and the MEK/ERK inhibitor U0126 attenuated the radiation-induced phosphorylation of GSK3β and altered the protein levels of Snail, α-SMA, and E-cadherin in RLE-6TN cells. Preincubating RLE-6TN cells with N-acetylcysteine, an antioxidant, abolished the radiation-induced phosphorylation of ERK and altered protein levels of Snail, E-cadherin, and α-SMA. These findings reveal, for the first time, that radiation-induced EMT in alveolar type II epithelial cells is mediated by the ERK/GSK3β/Snail pathway.
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Arcury TA, Weir M, Chen H, Summers P, Pelletier LE, Galván L, Bischoff WE, Mirabelli MC, Quandt SA.
Am J Ind Med. 2012 Mar ;55(3):191-204.
PMID: 22237961
The quality of housing provided to migrant farmworkers is often criticized, but few studies have investigated these housing conditions. This analysis examines housing regulation violations experienced by migrant farmworkers in North Carolina, and the associations of camp characteristics with the presence of housing violations.
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Chung E, Rylander MN.
Cell Stress Chaperones. 2012 Mar ;17(2):203-14.
PMID: 22116637
Conditioning protocols involving mechanical stress independently or with chemical cues such as growth factors (GFs) possess significant potential to enhance bone regeneration. However, utilization of thermal stress conditioning alone or with GFs for bone therapy has been under-investigated. In this study, a preosteoblast cell line (MC3T3-E1) was exposed to treatment with water bath heating (44°C, 4 and 8 min) and osteoinductive GFs (bone morphogenetic protein-2 and transforming growth factor-β1) individually or in combination to investigate whether these stimuli could promote induction of bone-related markers, an angiogenic factor, and heat shock proteins (HSPs). Cells remained viable when heating durations were less than 20 min at 40ºC, 16 min at 42ºC, and 10 min at 44ºC. Increasing heating duration at 44°C, promoted gene expression of HSPs, osteocalcin (OCN), and osteopontin (OPN) at 8 h post-heating (PH). Heating in combination with GFs caused the greatest gene induction of osteoprotegerin (OPG; 6.9- and 1.6-fold induction compared to sham-treated and GF only treated groups, respectively) and vascular endothelial growth factor (VEGF; 16.0- and 1.6-fold compared to sham and GF-only treated groups, respectively) at 8 h PH. Both heating and GFs independently suppressed the matrix metalloproteinase-9 (MMP-9) gene. GF treatment caused a more significant decrease in MMP-9 protein secretion to non-detectable levels compared to heating alone at 72 h PH. Secretion of OCN, OPN, and OPG increased with the addition of GFs but diminished with heating as measured by ELISA at 72 h PH. These results suggest that conditioning protocols utilizing heating and GFs individually or in combination can induce HSPs, bone-related proteins, and VEGF while also causing downregulation of osteoclastic activity, potentially providing a promising bone therapeutic strategy.
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Nicklas BJ, Gaukstern JE, Legault C, Leng I, Rejeski WJ.
Contemp Clin Trials. 2012 Mar ;33(2):450-5.
PMID: 22155531
There is a need to identify evidenced-based obesity treatments that are effective in maintaining lost weight. Weight loss results in reductions in energy expenditure, including spontaneous physical activity (SPA) which is defined as energy expenditure resulting primarily from unstructured mobility-related activities that occur during daily life. To date, there is little research, especially randomized, controlled trials, testing strategies that can be adopted and sustained to prevent declines in SPA that occur with weight loss. Self-monitoring is a successful behavioral strategy to facilitate behavior change, so a provocative question is whether monitoring SPA-related energy expenditure would override these reductions in SPA, and slow weight regain. This study is a randomized trial in older, obese men and women designed to test the hypothesis that adding a self-regulatory intervention (SRI), focused around self-monitoring of SPA, to a weight loss intervention will result in less weight and fat mass regain following weight loss than a comparable intervention that lacks this self-regulatory behavioral strategy. Participants (n=72) are randomized to a 5-month weight loss intervention with or without the addition of a behavioral component that includes an innovative approach to promoting increased SPA. Both groups then transition to self-selected diet and exercise behavior for a 5-month follow-up. Throughout the 10-month period, the SRI group is provided with an intervention designed to promote a SPA level that is equal to or greater than each individual's baseline SPA level, allowing us to isolate the effects of the SPA self-regulatory intervention component on weight and fat mass regain.
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Strowd RE, Geer C, Powers A, Abou-Zeid N.
J Clin Neurosci. 2012 Mar ;19(3):466-8.
PMID: 22249021
Spinal dural arteriovenous fistula (DAVF) is an acquired vascular malformation of the spinal cord that presents as a congestive myelopathy resulting from venous hypertension, edema, and ischemia within the cord. Acute clinical exacerbations have been demonstrated in a variety of clinical settings. We report a unique presentation of a 45-year-old male with progressive paraplegia that acutely worsened following three independent treatments with oral and intravenous steroid administration. Spinal angiogram revealed a spinal DAVF at L3 and the patient underwent successful surgical repair. This report highlights the clinical presentation of spinal DAVF and emphasizes the unique and important potential relationship between steroid administration and clinical deterioration.
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Hardison SA.
Ann Intern Med. 2012 Feb 21;156(4):319-20.
PMID: 22351719
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Edwards IJ.
Nat Rev Urol. 2012 Feb 21. [Epub ahead of print]
PMID: 22349653
The complexity and diversity of proteoglycan structure means that they have a range of functions that regulate cell behavior. Through multiple interactions of their core proteins and glycosaminoglycans with extracellular matrix proteins, growth factors and chemokines, proteoglycans affect cell signaling, motility, adhesion, growth and apoptosis. Progressive changes in proteoglycans occur in the tumor microenvironment, but neither the source nor consequences of those changes are well understood. Proteoglycans studied in prostate cancer include versican-a hyalectan regulator of cell adhesion and migration-and the small leucine-rich proteoglycans decorin, biglycan and lumican, which have roles in cell signaling and tissue organization. Studies support an inhibitory role in prostate cancer for decorin and lumican. Conversely, the basement membrane proteoglycan perlecan might be a tumor promoter through upregulation of sonic hedgehog signaling. Loss of the growth-inhibitory cell-surface proteoglycans syndecan-1 and betaglycan in early prostate cancer might facilitate progression, but syndecan-1 effects are pleiotropic and its renewed expression in advanced tumors might adversely affect outcome. Importantly, cellular changes and enzymatic activity in the developing tumor can alter proteoglycan composition and structure to modify their function. Emerging studies suggest that cancers, including those of the prostate, use these changes to promote their own survival, growth, and spread.
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Robbins ME, Brunso-Bechtold JK, Peiffer AM, Tsien CI, Bailey JE, Marks LB.
Radiat Res. 2012 Feb 21. [Epub ahead of print]
PMID: 22348250
Technological developments in radiation therapy and other cancer therapies have led to a progressive increase in five-year survival rates over the last few decades. Although acute effects have been largely minimized by both technical advances and medical interventions, late effects remain a concern. Indeed, the need to identify those individuals who will develop radiation-induced late effects, and to develop interventions to prevent or ameliorate these late effects is a critical area of radiobiology research. In the last two decades, preclinical studies have clearly established that late radiation injury can be prevented/ameliorated by pharmacological therapies aimed at modulating the cascade of events leading to the clinical expression of radiation-induced late effects. These insights have been accompanied by significant technological advances in imaging that are moving radiation oncology and normal tissue radiobiology from disciplines driven by anatomy and macrostructure to ones in which important quantitative functional, microstructural, and metabolic data can be noninvasively and serially determined. In the current article, we review use of positron emission tomography (PET), single photon emission tomography (SPECT), magnetic resonance (MR) imaging and MR spectroscopy to generate pathophysiological and functional data in the central nervous system, lung, and heart that offer the promise of, (1) identifying individuals who are at risk of developing radiation-induced late effects, and (2) monitoring the efficacy of interventions to prevent/ameliorate them.
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Beeman SM, Kemper AR, Madigan ML, Franck CT, Loftus SC.
Accid Anal Prev. 2012 Feb 17;47C():128-139.[Epub ahead of print]
PMID: 22342960
A total of 34 dynamic matched frontal sled tests were performed, 17 low (2.5g, Δv=4.8kph) and 17 medium (5.0g, Δv=9.7kph), with five male human volunteers of approximately 50th percentile height and weight, a Hybrid III 50th percentile male ATD, and three male PMHS. Each volunteer was exposed to two impulses at each severity, one relaxed and one braced prior to the impulse. A total of four tests were performed at each severity with the ATD and one trial was performed at each severity with each PMHS. A Vicon motion analysis system, 12 MX-T20 2 megapixel cameras, was used to quantify subject 3D kinematics (±1mm) (1kHz). Excursions of select anatomical regions were normalized to their respective initial positions and compared by test condition and between subject types. The forward excursions of the select anatomical regions generally increased with increasing severity. The forward excursions of relaxed human volunteers were significantly larger than those of the ATD for nearly every region at both severities. The forward excursions of the upper body regions of the braced volunteers were generally significantly smaller than those of the ATD at both severities. Forward excursions of the relaxed human volunteers and PMHSs were fairly similar except the head CG response at both severities and the right knee and C7 at the medium severity. The forward excursions of the upper body of the PMHS were generally significantly larger than those of the braced volunteers at both severities. Forward excursions of the PMHSs exceeded those of the ATD for all regions at both severities with significant differences within the upper body regions. Overall human volunteers, ATD, and PMHSs do not have identical biomechanical responses in low-speed frontal sled tests but all contribute valuable data that can be used to refine and validate computational models and ATDs used to assess injury risk in automotive collisions.
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Harris S, Chan MD, Lovato JF, Ellis TL, Tatter SB, Daniel Bourland J, Munley MT, Deguzman AF, Shaw EG, Urbanic JJ, McMullen KP.
Int J Radiat Oncol Biol Phys. 2012 Feb 17. [Epub ahead of print]
PMID: 22342297
PURPOSE: Radiosurgery has been successfully used in selected cases to avoid repeat whole-brain irradiation (WBI) in patients with multiple brain metastases of most solid tumor histological findings. Few data are available for the use of radiosurgery for small-cell lung cancer (SCLC). METHODS AND MATERIALS: Between November 1999 and June 2009, 51 patients with SCLC and previous WBI and new brain metastases were treated with GammaKnife stereotactic radiosurgery (GKSRS). A median dose of 18 Gy (range, 10-24 Gy) was prescribed to the margin of each metastasis. Patients were followed with serial imaging. Patient electronic records were reviewed to determine disease-related factors and clinical outcomes after GKSRS. Local and distant brain failure rates, overall survival, and likelihood of neurologic death were determined based on imaging results. The Kaplan-Meier method was used to determine survival and local and distant brain control. Cox proportional hazard regression was performed to determine strength of association between disease-related factors and survival. RESULTS: Median survival time for the entire cohort was 5.9 months. Local control rates at 1 and 2 years were 57% and 34%, respectively. Distant brain failure rates at 1 and 2 years were 58% and 75%, respectively. Fifty-three percent of patients ultimately died of neurologic death. On multivariate analysis, patients with stable (hazard ratio [HR] = 2.89) or progressive (HR = 6.98) extracranial disease (ECD) had worse overall survival than patients without evidence of ECD (p = 0.00002). Concurrent chemotherapy improved local control (HR = 89; p = 0.006). CONCLUSIONS: GKSRS represents a feasible salvage option in patients with SCLC and brain metastases for whom previous WBI has failed. The status of patients' ECD is a dominant factor predictive of overall survival. Local control may be inferior to that seen with other cancer histological results, although the use of concurrent chemotherapy may help to improve this.
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Grover M, Bernard CE, Pasricha PJ, Lurken MS, Faussone-Pellegrini MS, Smyrk TC, Parkman HP, Abell TL, Snape WJ, Hasler WL, McCallum RW, Nguyen L, Koch KL, Calles J, Lee L, Tonascia J, Unalp-Arida A, Hamilton FA, Farrugia G, .
Neurogastroenterol Motil. 2012 Feb 17. [Epub ahead of print]
PMID: 22339929
Background Cellular changes associated with diabetic (DG) and idiopathic gastroparesis (IG) have recently been described from patients enrolled in the Gastroparesis Clinical Research Consortium. The association of these cellular changes with gastroparesis symptoms and gastric emptying is unknown. The aim of this study was to relate cellular changes to symptoms and gastric emptying in patients with gastroparesis. Methods Earlier, using full thickness gastric body biopsies from 20 DG, 20 IG, and 20 matched controls, we found decreased interstitial cells of Cajal (ICC) and enteric nerves and an increase in immune cells in both DG and IG. Here, demographic, symptoms [gastroparesis cardinal symptom index score (GCSI)], and gastric emptying were related to cellular alterations using Pearson's correlation coefficients. Key Results Interstitial cells of Cajal counts inversely correlated with 4 h gastric retention in DG but not in IG (r = -0.6, P = 0.008, DG, r = 0.2, P = 0.4, IG). There was also a significant correlation between loss of ICC and enteric nerves in DG but not in IG (r = 0.5, P = 0.03 for DG, r = 0.3, P = 0.16, IG). Idiopathic gastroparesis with a myenteric immune infiltrate scored higher on the average GCSI (3.6 ± 0.7 vs 2.7 ± 0.9, P = 0.05) and nausea score (3.8 ± 0.9 vs 2.6 ± 1.0, P = 0.02) as compared to those without an infiltrate. Conclusions & Inferences In DG, loss of ICC is associated with delayed gastric emptying. Interstitial cells of Cajal or enteric nerve loss did not correlate with symptom severity. Overall clinical severity and nausea in IG is associated with a myenteric immune infiltrate. Thus, full thickness gastric biopsies can help define specific cellular abnormalities in gastroparesis, some of which are associated with physiological and clinical characteristics of gastroparesis.
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Ambrosius WT, Polonsky TS, Greenland P, Goff DC, Perdue LH, Fortmann SP, Margolis KL, Pajewski NM.
Clin Trials. 2012 Feb 16. [Epub ahead of print]
PMID: 22333998
BACKGROUND: Although observational evidence has suggested that the measurement of coronary artery calcium (CAC) may improve risk stratification for cardiovascular events and thus help guide the use of lipid-lowering therapy, this contention has not been evaluated within the context of a randomized trial. The Value of Imaging in Enhancing the Wellness of Your Heart (VIEW) trial is proposed as a randomized study in participants at low intermediate risk of future coronary heart disease (CHD) events to evaluate whether CAC testing leads to improved patient outcomes. PURPOSE: To describe the challenges encountered in designing a prototypical screening trial and to examine the impact of uncertainty on power. METHODS: The VIEW trial was designed as an effectiveness clinical trial to examine the benefit of CAC testing to guide therapy on a primary outcome consisting of a composite of nonfatal myocardial infarction, probable or definite angina with revascularization, resuscitated cardiac arrest, nonfatal stroke (not transient ischemic attack (TIA)), CHD death, stroke death, other atherosclerotic death, or other cardiovascular disease (CVD) death. Many critical choices were faced in designing the trial, including (1) the choice of primary outcome, (2) the choice of therapy, (3) the target population with corresponding ethical issues, (4) specifications of assumptions for sample size calculations, and (5) impact of uncertainty in these assumptions on power/sample size determination. RESULTS: We have proposed a sample size of 30,000 (800 events), which provides 92.7% power. Alternatively, sample sizes of 20,228 (539 events), 23,138 (617 events), and 27,078 (722 events) provide 80%, 85%, and 90% power. We have also allowed for uncertainty in our assumptions by computing average power integrated over specified prior distributions. This relaxation of specificity indicates a reduction in power, dropping to 89.9% (95% confidence interval (CI): 89.8-89.9) for a sample size of 30,000. Samples sizes of 20,228, 23,138, and 27,078 provide power of 78.0% (77.9-78.0), 82.5% (82.5-82.6), and 87.2% (87.2-87.3), respectively. LIMITATIONS: These power estimates are dependent on form and parameters of the prior distributions. CONCLUSIONS: Despite the pressing need for a randomized trial to evaluate the utility of CAC testing, conduct of such a trial requires recruiting a large patient population, making efficiency of critical importance. The large sample size is primarily due to targeting a study population at relatively low risk of a CVD event. Our calculations also illustrate the importance of formally considering uncertainty in power calculations of large trials as standard power calculations may tend to overestimate power. Clinical Trials 2012; 0: 1-15. http://ctj.sagepub.com.
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Levine EA, Blazer DG, Kim MK, Shen P, Stewart JH, Guy C, Hsu DS.
J Am Coll Surg. 2012 Feb 16. [Epub ahead of print]
PMID: 22342786
BACKGROUND: Treatment of peritoneal metastases from appendiceal and colon cancer with cytoreductive surgery and hyperthermic intraperitoneal chemotherapy (HIPEC) shows great promise. Although long-term disease-free survival is achieved in some cases with this procedure, many patients have recurrence. Oncologists have treated such recurrences of appendiceal cancer similarly to colorectal carcinoma, which has been largely ineffective. This study uses gene expression analysis of peritoneal metastases to better understand these neoplasms. STUDY DESIGN: From a prospectively maintained database and tissue bank, 41 snap frozen samples of peritoneal metastases (26 appendiceal, 15 colorectal) from patients undergoing HIPEC with complete cytoreduction and more than 3 years of follow-up underwent global gene expression analysis. Distinct phenotypes were identified using unsupervised hierarchical clustering based on differential gene expression. Survival curves restratified by genotype were generated. RESULTS: Three distinct phenotypes were found, 2 consisting of predominantly low grade appendiceal samples (10 of 13 in Cluster 1 and 15 of 20 in Cluster 2) and 1 consisting of predominantly colorectal samples (7 of 8 in Cluster 3). Cluster 1 consisted of patients with good prognosis and Clusters 2 and 3 consisted of patients with poor prognosis (p = 0.006). Signatures predicted survival of low- (Cluster 1) vs high-risk (Cluster 2) appendiceal (p = 0.04) and low-risk appendiceal (Cluster 1) vs colon primary (Cluster 3) (p = 0.0002). CONCLUSIONS: This study represents the first use of gene expression profiling for appendiceal cancer, and demonstrates genomic signatures quite distinct from colorectal cancer, confirming their unique biology. Consequently, therapy for appendiceal lesions extrapolated from colonic cancer regimens may be unfounded. These phenotypes may predict outcomes guiding patient management.
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Soler R, Füllhase C, Hanson A, Campeau L, Santos C, Andersson KE.
J Urol. 2012 Feb 16. [Epub ahead of print]
PMID: 22341818
PURPOSE: Different cell based therapies have been tested, focusing on motor function. We evaluated the effect of human amniotic fluid stem cells and bone marrow derived mesenchymal stem cells (ALLCELLS, Emeryville, California) on bladder dysfunction in a rat model of Parkinson disease. MATERIAL AND METHODS: A nigrostriatal lesion was induced by 6-hydroxydopamine in 96 athymic nude female rats divided into 3 treatment groups. After 2 weeks the groups were injected with human amniotic fluid stem cells, bone marrow derived mesenchymal stem cells and vehicle for sham treatment, respectively. At 3, 7, 14 and 28 days the bladder function of 8 rats per group was analyzed by conscious cystometry. Brains were extracted for immunostaining. RESULTS: The nigrostriatal lesion caused bladder dysfunction, which was consistent in sham treated animals throughout the study. Several cystometric parameters improved 14 days after human amniotic fluid stem cell or bone marrow derived mesenchymal stem cell injection, concomitant with the presence of human stem cells in the brain. At 14 days only a few cells were observed in a more caudal and lateral position. At 28 days the functional improvement subsided and human stem cells were no longer seen. Human stem cell injection improved the survival of dopaminergic neurons until 14 days. Human stem cells expressed superoxide dismutase-2 and seemed to modulate the expression of interleukin-6 and glial cell-derived neurotrophic factor by host cells. CONCLUSIONS: Cell therapy with human amniotic fluid stem cells and bone marrow derived mesenchymal stem cells temporarily ameliorated bladder dysfunction in a Parkinson disease model. In contrast to integration, cells may act on the injured environment via cell signaling.
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Hewitt CA, Kaiser AB, Roth S, Craps M, Czerw R, Carroll DL.
Nano Lett. 2012 Feb 16. [Epub ahead of print]
PMID: 22316286
Thermoelectrics are materials capable of the solid-state conversion between thermal and electrical energy. Carbon nanotube/polymer composite thin films are known to exhibit thermoelectric effects, however, have a low figure of merit (ZT) of 0.02. In this work, we demonstrate individual composite films of multiwalled carbon nanotubes (MWNT)/polyvinylidene fluoride (PVDF) that are layered into multiple element modules that resemble a felt fabric. The thermoelectric voltage generated by these fabrics is the sum of contributions from each layer, resulting in increased power output. Since these fabrics have the potential to be cheaper, lighter, and more easily processed than the commonly used thermoelectric bismuth telluride, the overall performance of the fabric shows promise as a realistic alternative in a number of applications such as portable lightweight electronics.
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Daniel RW, Rowson S, Duma SM.
Ann Biomed Eng. 2012 Feb 15. [Epub ahead of print]
PMID: 22350665
The head impact exposure for athletes involved in football at the college and high school levels has been well documented; however, the head impact exposure of the youth population involved with football has yet to be investigated, despite its dramatically larger population. The objective of this study was to investigate the head impact exposure in youth football. Impacts were monitored using a custom 12 accelerometer array equipped inside the helmets of seven players aged 7-8 years old during each game and practice for an entire season. A total of 748 impacts were collected from the 7 participating players during the season, with an average of 107 impacts per player. Linear accelerations ranged from 10 to 100 g, and the rotational accelerations ranged from 52 to 7694 rad/s(2). The majority of the high level impacts occurred during practices, with 29 of the 38 impacts above 40 g occurring in practices. Although less frequent, youth football can produce high head accelerations in the range of concussion causing impacts measured in adults. In order to minimize these most severe head impacts, youth football practices should be modified to eliminate high impact drills that do not replicate the game situations.
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McCall C, McCall WV.
J Clin Sleep Med. 2012;8(1):59-65.
PMID: 22334811
This study examined changes in sleep parameters between the laboratory and the home setting before and after laboratory monitoring in depressed insomniacs undergoing treatment.
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Papoiu AD, Coghill RC, Kraft RA, Wang H, Yosipovitch G.
Neuroimage. 2012 Feb 15;59(4):3611-23.
PMID: 22100770
Previous PET and fMRI brain imaging studies targeting neural networks processing itch sensation have used histamine as the sole itch inducer. In contrast with histamine, cowhage-induced itch is mediated via proteinase activated receptors PAR2 and is transmitted through a separate spinothalamic pathway, therefore imaging the brain activation evoked by cowhage could provide further insight into central processing of itch. We report for the first time a functional MRI Arterial Spin Labeling (ASL) study of neuronal processing of itch induced by cowhage, analyzed in contrast with histamine-induced itch. We also explored the brain responses induced by histamine and cowhage combined in a tight sequence. The results of our analyses obtained in a group of 15 healthy volunteers suggested that cowhage and histamine co-activated a core group of brain structures, while also revealing notable differences. Core areas activated by both stimuli were found in the thalamus, primary and secondary somatosensory cortices, posterior parietal cortex, superior and middle temporal cortices, PCC, ACC, precuneus and cuneus. Cowhage induced a notably distinct and more extensive involvement of the insular cortex, claustrum, basal ganglia, putamen, thalamic nuclei and pulvinar. The differences observed between these two itch modalities were investigated to determine the impact of quantitative versus qualitative factors, and correlations between itch intensity and the patterns in brain activation were explored. Our analysis revealed that the most significant differences between cowhage and histamine itch were not affected by stimulus intensity, although a subset of regions displayed activations which were intensity-dependent. The combined application of cowhage and histamine highlighted the role of insula and claustrum in the processing of both itch modalities in the same time. The present results suggest the existence of overlapping but also distinct neuronal networks processing these two different types of itch.
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