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Benoit Talbot, Maarten J Vonhof, Hugh G Broders, Brock Fenton, Nusha Keyghobadi
Parasite-host relationships create strong selection pressures that can lead to adaptation and increasing specialization of parasites to their hosts. Even in relatively loose host-parasite relationships, such as between generalist ectoparasites and their hosts, we may observe some degree of specialization of parasite populations to one of the multiple potential hosts. Salivary proteins are used by blood-feeding ectoparasites to prevent hemostasis in the host and maximize energy intake. We investigated the influence of association with specific host species on allele frequencies of salivary protein genes in Cimex adjunctus, a generalist blood-feeding ectoparasite of bats in North America...
March 15, 2018: Journal of Evolutionary Biology
Afrina Mustari, Naoki Nakamura, Satoko Kawauchi, Shunichi Sato, Manabu Sato, Izumi Nishidate
To evaluate cerebral hemodynamics and spontaneous low-frequency oscillations (SLFOs) of cerebral blood flow in rat brain, we investigated an imaging method using a digital RGB camera. In this method, the RGB values were converted into tristimulus values in the CIE (Commission Internationale de l'Eclairage) XYZ color space, which is compatible with the common RGB working spaces. Monte Carlo simulation for light transport in tissue was then used to specify the relationship among the tristimulus XYZ values and the concentrations of oxygenated hemoglobin ( C HbO ), deoxygenated hemoglobin ( C HbR ), and total hemoglobin ( C HbT ) and cerebral tissue oxygen saturation ( StO 2 )...
March 1, 2018: Biomedical Optics Express
Ryan L Sheppard, Joshua M Swift, Aaron Hall, Richard T Mahon
Introduction: Individuals with a known susceptibility to high altitude pulmonary edema (HAPE) demonstrate a reduced ventilation response and increased pulmonary vasoconstriction when exposed to hypoxia. It is unknown whether reduced sensitivity to hypercapnia is correlated with increased incidence and/or severity of HAPE, and while acute exercise at altitude is known to exacerbate symptoms the effect of exercise training on HAPE susceptibility is unclear. Purpose: To determine if chronic intermittent hypercapnia and exercise increases the incidence of HAPE in rats...
2018: Frontiers in Physiology
Thenappan Thenappan, Mark L Ormiston, John J Ryan, Stephen L Archer
Pulmonary hypertension is defined as a resting mean pulmonary artery pressure of 25 mm Hg or above. This review deals with pulmonary arterial hypertension (PAH), a type of pulmonary hypertension that primarily affects the pulmonary vasculature. In PAH, the pulmonary vasculature is dynamically obstructed by vasoconstriction, structurally obstructed by adverse vascular remodeling, and pathologically non-compliant as a result of vascular fibrosis and stiffening. Many cell types are abnormal in PAH, including vascular cells (endothelial cells, smooth muscle cells, and fibroblasts) and inflammatory cells...
March 14, 2018: BMJ: British Medical Journal
Seth W Holwerda, Rachel E Luehrs, Allene L Gremaud, Nealy A Wooldridge, Amy K Stroud, Jess G Fiedorowicz, Francois M Abboud, Gary L Pierce
Relative burst amplitude of muscle sympathetic nerve activity (MSNA) is an indicator of augmented sympathetic outflow and contributes to greater vasoconstrictor responses. Evidence suggests anxiety-induced augmentation of relative MSNA burst amplitude in patients with panic disorder, thus we hypothesized that acute stress would result in augmented relative MSNA burst amplitude and vasoconstriction in individuals with chronic anxiety. Eighteen participants with chronic anxiety (ANX, 8 men/10 women, 32{plus minus}2 years) and 18 healthy controls with low/no anxiety (CON, 8 men/10 women, 39{plus minus}3 years) were studied...
March 14, 2018: Journal of Neurophysiology
Alfonso Reimúndez, Carlos Fernández-Peña, Guillermo García, Rubén Fernández, Purificación Ordás, Rosalía Gallego, José L Pardo-Vazquez, Victor Arce, Félix Viana, Rosa Señarís
The coupling of energy homeostasis to thermoregulation is essential to maintain homeothermy in changing external environments. We studied the role of the cold thermoreceptor TRPM8 in this interplay in mice of both sexes. We demonstrate that TRPM8 is required for a precise thermoregulation in response to cold, in fed and fasting. Trpm8-/- mice exhibited a fall of 0.7 °C in core body temperature (Tc) when housed at cold temperatures, and a deep hypothermia (below 30 °C) during food deprivation. In both situations TRPM8-deficiency induced an increase in tail heat loss...
March 12, 2018: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
Kevin F Elwood, Robert W Wong
PURPOSE: To describe a case of transient, partial, central retinal artery occlusion with paracentral acute middle maculopathy optical coherence tomography presentation in a young healthy patient after ingestion of the synephrine-containing supplement, Havok. METHODS: Retrospective case report with fundus photography, fluorescein angiography, and optical coherence tomography. RESULTS: A 20-year-old man presented with severe acute vision loss in the right eye...
March 8, 2018: Retinal Cases & Brief Reports
Lucía Isidoro, Mercedes Ferrer, Mercedes Perusquía
BACKGROUND: Testosterone, 5α- and 5β-dihydrotestosterone (-DHT) induce an acute in vitro vasorelaxation and in vivo vasodepressor, hypotensive and antihypertensive responses. Our aim was to study whether androgen-induced blood pressure (BP) reduction is involved with a blockade of Ca2+ influx through L-type voltage-operated calcium channels (L-VOCCs) and/or the signaling pathways of α1 -adrenoceptors to induce vasoconstriction, which are one of the major mechanisms of BP maintenance...
March 12, 2018: Endocrine Research
Shotaro Kawakami, Tetsuhiko Yasuno, Takuro Matsuda, Kanta Fujimi, Ai Ito, Saki Yoshimura, Yoshinari Uehara, Hiroaki Tanaka, Takao Saito, Yasuki Higaki
BACKGROUND: High-intensity exercise reduces renal blood flow (RBF) and may transiently exacerbate renal dysfunction. RBF has previously been measured invasively by administration of an indicator material; however, non-invasive measurement is now possible with technological innovations. This study examined variations in RBF at different exercise intensities using ultrasound echo. METHODS: Eight healthy men with normal renal function (eGFRcys 114 ± 19 mL/min/1...
March 10, 2018: Clinical and Experimental Nephrology
Fanfan Li, Mengzhou He, Meitao Yang, Yao Fan, Yun Chen, Xi Xia, Yin Xie, Dongrui Deng
Preeclampsia (PE) is a pregnancy-specific, multi-system disorder and the leading cause of maternal and perinatal morbidity and mortality in obstetrics worldwide. Excessive vasoconstriction and dysregulated coagulation function are closely associated with PE. Heat shock protein 20 (HSP20) is ubiquitously expressed under normal physiological conditions and has important roles in vascular dilatation and suppression of platelet aggregation. However, the role of HSP20 in the pathogenesis of PE remains unclear. In this study, we collected chorionic plate resistance arteries (CPAs) and serum from 118 healthy pregnant women and 80 women with PE and detected the levels of HSP20 and its phosphorylated form...
March 9, 2018: Frontiers of Medicine
Christine C Helms, Mark T Gladwin, Daniel B Kim-Shapiro
Erythrocytes regulate vascular function through the modulation of oxygen delivery and the scavenging and generation of nitric oxide (NO). First, hemoglobin inside the red blood cell binds oxygen in the lungs and delivers it to tissues throughout the body in an allosterically regulated process, modulated by oxygen, carbon dioxide and proton concentrations. The vasculature responds to low oxygen tensions through vasodilation, further recruiting blood flow and oxygen carrying erythrocytes. Research has shown multiple mechanisms are at play in this classical hypoxic vasodilatory response, with a potential role of red cell derived vasodilatory molecules, such as nitrite derived nitric oxide and red blood cell ATP, considered in the last 20 years...
2018: Frontiers in Physiology
Jenny Skytte Larsson, Vitus Krumbholz, Anders Enskog, Gudrun Bragadottir, Bengt Redfors, Sven-Erik Ricksten
OBJECTIVE: Data on renal hemodynamics, function, and oxygenation in early clinical septic shock are lacking. We therefore measured renal blood flow, glomerular filtration rate, renal oxygen consumption, and oxygenation in patients with early septic shock. DESIGN: Prospective comparative study. SETTING: General and cardiothoracic ICUs. PATIENTS: Patients with norepinephrine-dependent early septic shock (n = 8) were studied within 24 hours after arrival in the ICU and compared with postcardiac surgery patients without acute kidney injury (comparator group, n = 58)...
March 6, 2018: Critical Care Medicine
Torill Berg
K+ -channels of the Kv7/KCNQ-family hyperpolarize and stabilize excitable cells such as autonomic neurons and vascular smooth muscle cells (VSMC). Kv7 may therefore play a role in blood pressure (BP) homeostasis, and prevent a high total peripheral vascular resistance (TPR), a hallmark of hypertensive disease. The present study analyzed if Kv7 channels influence catecholamine release and TPR in normotensive (WKY) and spontaneously hypertensive rats (SHR), and if they may contribute to the antihypertensive protection seen in young, female SHR...
2018: Frontiers in Physiology
Scott E Rudkin, Craig L Anderson, Tristan R Grogan, David A Elashoff, Richard M Treger
BACKGROUND AND OBJECTIVES: In severe circulatory failure agreement between arterial and mixed venous or central venous values is poor; venous values are more reflective of tissue acid-base imbalance. No prior study has examined the relationship between peripheral venous blood gas (VBG) values and arterial blood gas (ABG) values in hemodynamic compromise. The objective of this study was to examine the correlation between hemodynamic parameters, specifically systolic blood pressure (SBP) and the arterial-peripheral venous (A-PV) difference for all commonly used acid-base parameters (pH, Pco2 , and bicarbonate)...
January 1, 2018: Journal of Intensive Care Medicine
Baraa K Al-Khazraji, Leena N Shoemaker, Joseph S Gati, Trevor Szekeres, J Kevin Shoemaker
The larger intracranial conduit vessels contribute to the total cerebral vascular resistance, and understanding their vasoreactivity to physiological stimuli is required when attempting to understand regional brain perfusion. Reactivity of the larger cerebral conduit arteries remains understudied due to a need for improved imaging methods to simultaneously assess these vessels in a single stimulus. We characterized reactivity of basal intracranial conduit arteries (basilar, right and left posterior, middle and anterior cerebral arteries) and the right and left internal carotid arteries, to manipulations in end-tidal CO2 (PetCO2 )...
January 1, 2018: Journal of Cerebral Blood Flow and Metabolism
Hua Su, Chen Ye, Qian Wen, Hong-Yan Zhu, Li-Xia Yi, Chun Zhang
BACKGROUND: It is well-recognized that injection of iodinated radiographic contrast media (CM) sometimes causes acute renal injury via multiple mechanisms, such as vasoconstriction, toxicity on glomerular endothelium and tubular epithelium and so forth. CASE PRESENTATION: A 51-year-old man developed acute renal injury with proteinuria after CM administration. To our surprise, in his renal biopsy sample the myelin figure like structure was observed in glomerular endothelium and mesangial cells by transmission electron microscopy...
March 6, 2018: BMC Nephrology
Ijad Kao, Yu Xiong, Axel Steffen, Kathrin Smuda, Lian Zhao, Radostina Georgieva, Axel Pruss, Hans Bäumler
Hemoglobin-based oxygen carriers (HBOCs) are being developed as oxygen and plasma volume-expanding therapeutics though their potential to promote oxidative tissue injury and nitric oxide (NO) scavenging combined with vasoconstriction has raised safety concerns. Therefore, we focused on these aspects during preclinical studies performed with the recently introduced hemoglobin microparticles (HbMP-700). Besides oxidative stress, we investigated possible vasoconstrictory influence of HBOCs as well as genetic toxicity...
March 6, 2018: Artificial Organs
Craig P Allen, Kicheon Park, Ang Li, Nora D Volkow, George F Koob, Yingtian Pan, Xiu-Ti Hu, Congwu Du
Cocaine addiction is associated with dysfunction of the prefrontal cortex (PFC), which facilitates relapse and compulsive drug taking. To assess if cocaine's effects on both neuronal and vascular activity contribute to PFC dysfunction, we used optical coherence tomography and multi-wavelength laser speckle to measure vascularization and hemodynamics and used GCaMP6f to monitor intracellular Ca2+ levels ([Ca2+ ]in ) as a marker of neuronal activity. Rats were given short (1 hour; ShA) or long (6 hours; LgA) access cocaine self-administration...
March 5, 2018: Addiction Biology
Natalie G Ormshaw, Rehan T Junejo, Janice M Marshall
PURPOSE: Prevalence of cardiovascular disease (CVD) is greater in South Asians (SAs) than White Europeans (WEs). Endothelial dysfunction and blunted forearm vasodilatation to environmental stressors have been implicated in CVD. We investigated whether these features are present in young SA men. METHODS: In 15 SA and 16 WE men (19-23 years), we compared changes in forearm blood flow, arterial blood pressure (ABP), forearm vascular conductance (FVC), heart rate, and electrodermal resistance (EDR; sweating) following release of arterial occlusion (reactive hyperaemia endothelium-dependent) and 5 single sounds at 5-10 min intervals (stressors)...
March 3, 2018: European Journal of Applied Physiology
Tadashi Tsubouchi, Takeshi Kunimatsu, Shinji Tsujimoto, Akihiko Kiyoshi, Yasunori Katsura, Seiko Oku, Kazuhiro Chihara, Yukiko Mine, Toru Yamada, Isao Shimizu, Kiyoko Bando
The pharmacological activity of DSP-6952, a novel compound was investigated, compared to that of clinically efficacious gastrointestinal (GI) prokinetic 5-hydroxytryptamine4 (5-HT4 ) receptor agonists. DSP-6952 had a strong affinity of Ki=51.9nM for 5-HT4(b) receptor, and produced contraction in the isolated guinea pig colon with EC50 of 271.6nM and low intrinsic activity of 57%, similar to tegaserod and mosapride. In the development of the 5-HT4 receptor agonists, cardiovascular risk was deliberately evaluated, because some related prokinetics were reported to cause with cardiovascular adverse events, such as ventricular arrhythmias or ischemia...
March 1, 2018: European Journal of Pharmacology
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