Slowly cycling Rho kinase-dependent actomyosin cross-bridge slippage explains intrinsic high compliance of detrusor smooth muscle

Biological soft tissues are viscoelastic because they display timeindependent pseudoelasticity and time-dependent viscosity. However, there is evidence that the bladder may also display plasticity, defined as an increase in strain that is unrecoverable unless work is done by the muscle. In the present study, an electronic lever was used to induce controlled changes in stress and strain to determine whether rabbit detrusor smooth muscle (rDSM) is best described as viscoelastic or viscoelastic plastic. Using sequential ramp loading and unloading cycles, stress-strain and stiffness-stress analyses revealed that rDSM displayed reversible viscoelasticity, and that the viscous component was responsible for establishing a high stiffness at low stresses that increased only modestly with increasing stress compared with the large increase produced when the viscosity was absent and only pseudoelasticity governed tissue behavior. The study also revealed that rDSM underwent softening correlating with plastic deformation and creep that was reversed slowly when tissues were incubated in a Ca2+ -containing solution. Together, the data support a model of DSM as a viscoelastic-plastic material, with the plasticity resulting from motor protein activation. This model explains the mechanism of intrinsic bladder compliance as slipping cross bridges, predicts that wall tension is dependent not only on vesicle pressure and radius but also on actomyosin cross-bridge activity, and identifies a novel molecular target for compliance regulation, both physiologically and therapeutically

UAS-SfM for coastal research : geomorphic feature extraction and land cover classification from high-resolution elevation and optical imagery

© The Author(s), 2017. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Remote Sensing 9 (2017): 1020, doi:10.3390/rs9101020.The vulnerability of coastal systems to hazards such as storms and sea-level rise is typically characterized using a combination of ground and manned airborne systems that have limited spatial or temporal scales. Structure-from-motion (SfM) photogrammetry applied to imagery acquired by unmanned aerial systems (UAS) offers a rapid and inexpensive means to produce high-resolution topographic and visual reflectance datasets that rival existing lidar and imagery standards. Here, we use SfM to produce an elevation point cloud, an orthomosaic, and a digital elevation model (DEM) from data collected by UAS at a beach and wetland site in Massachusetts, USA. We apply existing methods to (a) determine the position of shorelines and foredunes using a feature extraction routine developed for lidar point clouds and (b) map land cover from the rasterized surfaces using a supervised classification routine. In both analyses, we experimentally vary the input datasets to understand the benefits and limitations of UAS-SfM for coastal vulnerability assessment. We find that (a) geomorphic features are extracted from the SfM point cloud with near-continuous coverage and sub-meter precision, better than was possible from a recent lidar dataset covering the same area; and (b) land cover classification is greatly improved by including topographic data with visual reflectance, but changes to resolution (when <50 cm) have little influence on the classification accuracy.This project was funded by the U.S. Geological Survey (USGS) Coastal and Marine Geology Program and the Department of the Interior Northeast Climate Science Center

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Role of Protein Kinase Cζ and Calcium Entry in KCl-Induced Vascular Smooth Muscle Calcium Sensitization and Feedback Control of Cellular Calcium Levels

The degree of tonic force (F) maintenance induced in vascular smooth muscle upon K+ depolarization with 110 mM KCl can be greatly reduced by inhibition of rhoA kinase (ROCK). We explored the possibility that a protein kinase C (PKC) isotype may also play a role in causing KCl-induced Ca2+ sensitization. In isometric rings of rabbit artery, the PKC inhibitors, Go-6983 (3-[1-[3-(dimethylamino)propyl]-5-methoxy-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione), GF-109203X (2-[1-(3-dimethylaminopropyl)indol-3-yl]-3-(indol-3-yl) maleimide), and a cell-permeable (myristoylated) pseudosubstrate inhibitor of PKCζ (PIPKCζ) inhibited KCl-induced tonic F. A myristoylated pseudosubstrate inhibitor of PKCα/β that inhibited phorbol dibutyrate-induced F slightly potentiated KCl-induced tonic F and attenuated 30 mM KCl-induced F. Although the ROCK inhibitor, H-1152 [(S)-(+)-2-methyl-1-[(4-methyl-5-isoquinolinyl)-sulfonyl]-hexahydro-1H-1,4-diazepine dihydrochloride], reduced basal phosphorylation of myosin light-chain phosphatase-targeting subunit at Thr853 (MYPT1-pT853), 3 and 10 μM GF-109203X inhibited only KCl-stimulated phosphorylation, not basal MYPT1-pT853. In fura-2-loaded tissues, GF-109203X and PIPKCζ elevated basal [Ca2+]i (calcium) and potentiated KCl-induced tonic increases in calcium while reducing KCl-induced tonic increases in F. Blockade by nifedipine of Ca2+ entry through voltage-operated Ca2+ channels reduced KCl-induced Ca2+ sensitization and KCl-stimulated but not basal MYPT1-pT853. These data together support a model in which ROCK and PKCζ are constitutively active and function in “resting” muscle to regulate the basal levels of MYPT1-pT853 and calcium, respectively. In this model, KCl-induced increases in calcium activate PKCζ to feed forward and cause additional MYPT1-pT853 above that induced by constitutive ROCK, permitting Ca2+ sensitization and strong F maintenance. Active PKCζ also feeds back to attenuate the degree of KCl-induced increases in calcium

Influence of gender and age on the peripheral immune response in stroke

Background: Women and men have unique stroke risk factors and can experience different poststroke infections. Objective: The aim of this study is to determine the influence of gender, age, and risk factors on the peripheral immune response in stroke/transient ischemic attack (TIA). Method: A total of 192 adult acute stroke/TIA cases were analyzed for age, gender, risk factors for stroke/TIA, and white blood cell with differential count. χ2 Test and analysis of variance were conducted to test for differences between genders and age groups related to stroke risk factors and the immune response. Growth modeling was used to test for trended differences in the immune response. Results: Women were 4 years older than men; fewer women had strokes in the younger age group (<79 years) and more men currently smoked. Trended lymphocyte percentages for the young and old (slope, P = .04; pattern, P = .02) and admission monocyte percentages by gender were significantly different (P = .01). Conclusions: Age influenced trended lymphocyte numbers and gender influenced monocyte percentage on admission

Peripheral immune response and infection in first-time and recurrent ischemic stroke or transient ischemic attack

Goals: The aims of this study were to determine if the infection rate differs between the first and recurrent ischemic stroke/transient ischemic attack (TIA), if the pattern of the peripheral immune response (PIR) differs between the first and recurrent ischemic stroke/TIA and if infection further influenced the pattern of the PIR. Methods: Retrospective review of 500 stroke cases with strict exclusion criteria (e.g., hemorrhagic stroke, subarachnoid hemorrhage, or spontaneous intracerebral hemorrhage; history of cancer; on steroids or immune suppressive drugs; recent invasive procedure) resulted in inclusion of 198 cases. Independent variables were first stroke or recurrent stroke and not infected or infected cases. Main-effect dependent variables were the white blood cell (WBC) and differential leukocyte counts (percentages of 100 cell counts for neutrophils, lymphocytes, and monocytes and absolute counts of neutrophils, lymphocytes, and monocytes). Findings: Infection rate was not different between the first versus recurrent stroke (p = .279). The pattern of WBC and differential counts were not different between groups, but addition of the covariate of infection showed group differences (p = .05). A four-group comparison of the dependent variables with the laboratory normal ranges showed lymphocyte percentages below the lower range limit in all four groups. Generalized linear modeling showed a modest rise (15%) in WBC counts in both groups with concomitant infection, a modestly low (−18%) lymphocyte percentage in recurrent stroke with infection, and a more substantial rise (22%–26%) in absolute neutrophil count in both groups with concomitant infection. Conclusions: Infection influences the pattern of the PIR in the first and recurrent stroke/TIA, and this difference can be quantified

Influence of Gender and Age on the Peripheral Immune Response in Stroke

Background: Women and men have unique stroke risk factors and can experience different poststroke infections. Objective: The aim of this study is to determine the influence of gender, age, and risk factors on the peripheral immune response in stroke/transient ischemic attack (TIA). Method: A total of 192 adult acute stroke/TIA cases were analyzed for age, gender, risk factors for stroke/TIA, and white blood cell with differential count. χ2 Test and analysis of variance were conducted to test for differences between genders and age groups related to stroke risk factors and the immune response. Growth modeling was used to test for trended differences in the immune response. Results: Women were 4 years older than men; fewer women had strokes in the younger age group (<79 years) and more men currently smoked. Trended lymphocyte percentages for the young and old (slope, P = .04; pattern, P = .02) and admission monocyte percentages by gender were significantly different (P = .01). Conclusions: Age influenced trended lymphocyte numbers and gender influenced monocyte percentage on admission

The Influence of β-Adrenergic Receptor Kinase-1 on Stroke-induced Immunodeficiency Syndrome

Background: Immunodeficiency in acute ischemic stroke (AIS) is thought to be a result of norepinephrine suppression of the lymphoid tissue. The possible differences in the distribution of lymphocytes after stroke may be due to differences in responsiveness of lymphocyte β-adrenergic receptors to their kinase (BARK-1). Objective: The objective was to quantify the influence of lymphocyte BARK-1 on stroke-induced immunodeficiency in AIS patients. Methods: A prospective clinical cohort study was conducted (N = 44). Measures included age, gender, race, risk factors for stroke, stroke severity, comorbidities, presence of infection, white blood cell counts and differential proportions, and lymphocyte BARK-1. Student t tests, effect sizes, and linear and logistic regressions were conducted to test the study objective. The study was approved by the Oregon Health & Science University Institutional Review Board. Results: There were significant changes in all white blood cells and differential proportions and in the National Institutes of Health Stroke Scale from admission to 48 hours after onset of stroke deficits. Higher BARK-1 influenced the lower lymphocyte proportion at 48 hours, independent of age, P < .0001. Furthermore, BARK-1 also was associated with an increase in the likelihood of having sustained or stroke-induced immunodeficiency at 48 hours: odds ratio, 2.41; 95% confidence interval, 1.10–5.25; P = .027, and odds ratio, 2.79; 95% confidence interval, 1.03–7.52; P = .043, respectively. In all backward stepwise selection of factors, BARK-1 was the only factor consistently retained in the models. Conclusions: β-Adrenergic receptor kinase-1 has a significant quantifiable influence on lymphocyte proportion at 48 hours and on the classification of sustained stroke-induced immunodeficiency. Clinical Implications: β-Adrenergic stimulation influences immunodeficiency in AIS

The influence of β-adrenergic receptor kinase-1 on stroke-induced immunodeficiency syndrome

Background: Immunodeficiency in acute ischemic stroke (AIS) is thought to be a result of norepinephrine suppression of the lymphoid tissue. The possible differences in the distribution of lymphocytes after stroke may be due to differences in responsiveness of lymphocyte β-adrenergic receptors to their kinase (BARK-1). Objective: The objective was to quantify the influence of lymphocyte BARK-1 on stroke-induced immunodeficiency in AIS patients. Methods: A prospective clinical cohort study was conducted (N = 44). Measures included age, gender, race, risk factors for stroke, stroke severity, comorbidities, presence of infection, white blood cell counts and differential proportions, and lymphocyte BARK-1. Student t tests, effect sizes, and linear and logistic regressions were conducted to test the study objective. The study was approved by the Oregon Health & Science University Institutional Review Board. Results: There were significant changes in all white blood cells and differential proportions and in the National Institutes of Health Stroke Scale from admission to 48 hours after onset of stroke deficits. Higher BARK-1 influenced the lower lymphocyte proportion at 48 hours, independent of age, P < .0001. Furthermore, BARK-1 also was associated with an increase in the likelihood of having sustained or stroke-induced immunodeficiency at 48 hours: odds ratio, 2.41; 95% confidence interval, 1.10–5.25; P = .027, and odds ratio, 2.79; 95% confidence interval, 1.03–7.52; P = .043, respectively. In all backward stepwise selection of factors, BARK-1 was the only factor consistently retained in the models. Conclusions: β-Adrenergic receptor kinase-1 has a significant quantifiable influence on lymphocyte proportion at 48 hours and on the classification of sustained stroke-induced immunodeficiency. Clinical Implications: β-Adrenergic stimulation influences immunodeficiency in AIS