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Heart Activity (heart + activity)
Selected AbstractsRole of the neuropeptide CCAP in Drosophila cardiac functionDEVELOPMENTAL NEUROBIOLOGY, Issue 3 2005Davide Dulcis Abstract The heartbeat of adult Drosophila melanogaster displays two cardiac phases, the anterograde and retrograde beat, which occur in cyclic alternation. Previous work demonstrated that the abdominal heart becomes segmentally innervated during metamorphosis by peripheral neurons that express crustacean cardioactive peptide (CCAP). CCAP has a cardioacceleratory effect when it is applied in vitro. The role of CCAP in adult cardiac function was studied in intact adult flies using targeted cell ablation and RNA interference (RNAi). Optical detection of heart activity showed that targeted ablation of CCAP neurons selectively altered the anterograde beat, without apparently altering the cyclic cardiac reversal. Normal development of the abdominal heart and of the remainder of cardiac innervation in flies lacking CCAP neurons was confirmed by immunocytochemistry. Thus, in addition to its important role in ecdysis behavior (the behavior used by insects to shed the remains of the old cuticle at the end of the molt), CCAP may control the level of activity of the anterograde cardiac pacemaker in the adult fly. Expression of double stranded CCAP RNA in the CCAP neurons (targeted CCAP RNAi) caused a significant reduction in CCAP expression. However, this reduction was not sufficient to compromise CCAP's function in ecdysis behavior and heartbeat regulation. © 2005 Wiley Periodicals, Inc. J Neurobiol, 2005 [source] Early signs of lethal effects in Daphnia magna (Branchiopoda, Cladocera) exposed to the insecticide cypermethrin and the fungicide azoxystrobinENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 10 2010Ursula Friberg-Jensen Abstract This study presents the effects of sublethal concentrations of pesticides cypermethrin and azoxystrobin on the activity of several physiological parameters of egg-carrying Daphnia magna studied using a video-image technique. Single tethered daphnids were continuously recorded for 24,h of pesticide exposure, and the activity of the heart, the filtering limbs, the mandibles, and the focal spine were subsequently analyzed. Acute toxicity tests based on the criteria of immobilization were performed on egg-carrying D. magna, and sublethal concentrations of 0.1, 1.0, and 10,µg/L cypermethrin and 0.5, 1.0, and 2.0,mg/L azoxystrobin were established. At a concentration as low as 0.1,µg/L cypermethrin, the 5% effective concentration after 24,h of exposure (EC5,24h), the activity of the focal spine increased and the filtering limb activity decreased. The activity of the mandibles was reduced by exposure to 1.0 (EC18,24,h) and 10,µg/L (EC41,24,h) cypermethrin, whereas heart activity increased at a concentration of 10,µg/L (EC41,24,h). With regard to azoxystrobin, the activity of all response parameters except the focal spine decreased by exposure to 0.5,mg/L (EC4,24h) azoxystrobin. The focal spine was not affected by azoxystrobin. The results show that physiological mechanisms important for ingestion of food in D. magna may be impaired by low concentrations of commonly used pesticides. Environ. Toxicol. Chem. 2010;29:2371,2378. © 2010 SETAC [source] A cardiac signature of emotionalityEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 11 2007Stefan Koelsch Abstract Human personality has brain correlates that exert manifold influences on biological processes. This study investigates relations between emotional personality and heart activity. Our data demonstrate that emotional personality is related to a specific cardiac amplitude signature in the resting electrocardiogram (ECG). Two experiments using functional magnetic resonance imaging show that this signature correlates with brain activity in the amygdala and the hippocampus during the processing of musical stimuli with emotional valence. Additionally, this cardiac signature correlates with subjective indices of emotionality (as measured by the Revised Toronto Alexithymia Scale), and with both time and frequency domain measures of the heart rate variability. The results demonstrate intricate connections between emotional personality and the heart by showing that ECG amplitude patterns provide considerably more information about an individual's emotionality than previously believed. The finding of a cardiac signature of emotional personality opens new perspectives for the investigation of relations between emotional dysbalance and cardiovascular disease. [source] Functional morphology of embryonic development in the Port Jackson shark Heterodontus portusjacksoni (Meyer)JOURNAL OF FISH BIOLOGY, Issue 4 2008K. R. Rodda The oviparous Port Jackson shark Heterodontus portusjacksoni embryo has a long incubation of 10,11 months during which it undergoes major morphological changes. Initially the egg capsule is sealed from the external environment by mucous plugs in either end of the capsule. Four months into incubation, the egg capsule opens to the surrounding sea water. Fifteen stages of development are defined for this species, the first 10 occur within the sealed capsule, the remaining five after capsule opening to hatching. The functional significance of major definitive characters such as circulation within the yolk membrane and embryo, rhythmic lateral movement of the embryo, external gill filaments, heart activity, internal yolk supplies, egg jelly and the significance of the opening of the egg capsule are described. The egg jelly in the sealed capsule functions to mechanically protect the embryo during early development, however, it eventually creates a hypoxic environment to the embryo as the available oxygen is used up. This generates several physiological challenges to the developing embryo. It is able to overcome these problems by morphological changes such as increasing the effective surface area for gaseous exchange with the development of external gill filaments, fins and extensive circulation in both the embryo and attached external yolk sac. These adaptations become limiting as the embryo grows and respiratory needs outweigh the available oxygen. At this time, the mucous plugs dissolve and the capsule becomes open to the external environment. [source] Blink rate in boys with fragile X syndrome: preliminary evidence for altered dopamine functionJOURNAL OF INTELLECTUAL DISABILITY RESEARCH, Issue 9 2005J. E. Roberts Abstract Background Dopamine, a neurotransmitter involved in motor and cognitive functioning, can be non-invasively measured via observation of spontaneous blink rates. Blink rates have been studied in a number of clinical conditions including schizophrenia, autism, Parkinsons, and attention deficit/hyperactivity disorder with results implicating either hyper or hypo dopaminergic states. Methods This study examined spontaneous blink rate in boys with fragile X syndrome (FXS). Blink rates of boys (4,8 years old) with FXS (n = 6) were compared with those of age-matched typically developing boys (n = 6) during active and passive tasks. Blink rates (blinks per minute) for each task were compared between the two groups. Then, the relation between blink measures and core FXS-related features [problem behaviours, arousal, fmr 1 protein (FMRP)] were examined within the group of boys with FXS. Results Blink rate in boys with FXS was significantly higher than typically developing boys during passive tasks. Within the FXS group, there were significant correlations between blink rate and problem behaviours and physiological arousal (i.e. heart activity) but not with FMRP. Conclusions Observed differences in spontaneous blink rate between boys with and without FXS and the relation between blink rate and physiological and behavioural measures in boys with FXS suggests that further work examining dopamine dysfunction as, a factor in the pathophysiology of FXS may be warranted. [source] ORIGINAL ARTICLE: Treatment with Adalimumab (Humira®) and Intravenous Immunoglobulin Improves Pregnancy Rates in Women Undergoing IVF,AMERICAN JOURNAL OF REPRODUCTIVE IMMUNOLOGY, Issue 2 2009Edward E. Winger Problem, The purpose of this study was to investigate whether treatment with TNF-, inhibitors and/or intravenous immunoglobulin (IVIG) increases in vitro fertilization (IVF) success rates among young (<38 years) women with infertility and T helper 1/T helper 2 cytokine elevation. Method of study, Seventy-five sub-fertile women with Th1/Th2 cytokine elevation were divided into four groups: Group I: Forty-one patients using both IVIG and Adalimumab (Humira®), Group II: Twenty-three patients using IVIG, Group III: Six patients using Humira®, and Group IV: Five patients using no IVIG or Humira®. Results, The implantation rate (number of gestational sacs per embryo transferred, with an average of two embryos transferred by cycle) was 59% (50/85), 47% (21/45), 31% (4/13) and 0% (0/9) for groups I, II, III and IV respectively. The clinical pregnancy rate (fetal heart activity per IVF cycle started) was 80% (33/41), 57% (13/23), 50% (3/6) and 0% (0/5) and the live birth rate was 73% (30/41), 52% (12/23), 50% (3/6) and 0% (0/5) respectively. There was a significant improvement in implantation, clinical pregnancy and live birth rates for group I versus group IV (P = 0.0007, 0.0009, and 0.003, respectively) and for group II versus group IV (P = 0.009, 0.04 and 0.05, respectively). Conclusion, The use of a TNF-, inhibitor and IVIG significantly improves IVF outcome in young infertile women with Th1/Th2 cytokine elevation. [source] Gase als zelluläre Signalstoffe.BIOLOGIE IN UNSERER ZEIT (BIUZ), Issue 3 2010Gasotransmitter Abstract Die Gase Stickoxid (NO), Kohlenmonoxid (CO) und Schwefelwasserstoff (H2S) werden aufgrund ihrer Wirkung als Signalstoffe als "Gasotransmitter" zusammengefasst. Diese Gase spielen eine wichtige Rolle als intra- und interzellulärer Signalstoff im Verdauungs-, Atmungs- oder Urogenitalsystem, bei der Steuerung des Herzschlags oder Nervenaktivitäten. Die Forschung ist dabei, Funktionen und weitere Details der Wirkmechanismen dieser Gase und ihre Implikationen für Physiologie, Pathophysiologie und Pharmakologie zu erarbeiten. Vom bisher neuesten Kandidaten , dem H2S , gibt es Hinweise, dass er in hoher Konzentration im Gehirn und in den Hoden vorkommt und bei Lern-/Gedächtnisprozessen sowie bei Geschlechtsfunktionen eine Rolle spielt. Durch Entwicklung von Wirksubstanzen zur Beeinflussung der H2S-Produktion oder entsprechender Zielorte könnte sich hieraus ein interessantes pharmakologisches Potenzial entwickeln. Gasotransmitters , gases as cellular signalling molecules The gases nitric oxide (NO), carbon monoxide (CO) and hydrogen sulphide (H2S) because of their capacity as signalling molecules have been now collectively termed "gasotransmitters". These gases play an important role in inter- and intracellular signalling, as in the digestive, respiratory or urogenital tract, in controlling heart activity or in nerve function. Research now tries to work out functions and further details about the mechanism of action of these gases and their implications for physiology, pathophysiology and pharmacology. The most recent candidate, H2S, is found in high concentrations in the brain and in the testis and hence is involved in learning/memory and in reproductive functions. The development of new substances interfering with the production of H2S or its targets may constitute an interesting pharmacological potential. [source] | |||||||||||||