Search results for "RCA"
showing 10 items of 3171 documents
Infradian rhythms of serotonin and serotonin‐N‐acetyltransferase in the pineal gland of male rats
1983
Abstract The present investigation was carried out to determine whether in the pineal gland of male Sprague‐Dawley rats infradian rhythms with respect to serotonin, serotonin‐N‐acetyltransferase (NAT) activity, and hydroxyindole‐O‐methyltransferase (HIOMT) can be detected. The serotonin data obtained over a period of 4 weeks and subjected to power spectral analysis suggest the presence of infradian rhythms in the range of 6 and 4.3 days. NAT activity, obtained over a period of 28 days, revealed a 7‐day‐rhythm. A second peak occurring at 2.3 days remained just below the significance limit. HIOMT activity studied over a period of 8 days showed no statistically significant differences between …
Self-reported reasons for on-duty sleepiness among commercial airline pilots
2021
Experimental and epidemiological research has shown that human sleepiness is determined especially by the circadian and homeostatic processes. The present field study examined which work-related factors airline pilots perceive as causing on-duty sleepiness during short-haul and long-haul flights. In addition, the association between the perceived reasons for sleepiness and actual sleepiness levels was examined, as well as the association between reporting inadequate sleep causing sleepiness and actual sleep-wake history. The study sample consisted of 29 long-haul (LH) pilots, 28 short-haul (SH) pilots, and 29 mixed fleet pilots (flying both SH and LH flights), each of whom participated in a…
Zirkadiane Blutdruckrhythmik bei der Präeklampsie: Ein Prädiktor für die maternale und geburtshilfliche Situation?
2003
Background Preeclampsia is a pregnancy-induced multiorganic disease. The incidence is 5 - 7 % in all pregnant women. To assess the value of circadian blood pressure rhythm in preeclamptic women, 24-hour blood pressure monitoring might be useful. The purpose of this study was to determine the predictive value of circadian blood pressure rhythm for the maternal and obstetrical outcome in patients with mild preeclampsia. Patients and methods Sixty-six patients with mild preeclampsia underwent 24-hour blood pressure monitoring between 29 and 39 weeks gestation. Twenty-eight patients with normal circadian blood pressure rhythm were compared with thirty-eight patients with suspended circadian blo…
Effectiveness of interventions to improve cancer treatment and follow-up care in socially disadvantaged groups.
2019
Objective To identify and characterize the interventions that aimed to improve cancer treatment and follow-up care in socially disadvantaged groups. To summarize the state of the art for clinicians and researchers. Methods We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Eligible studies were randomized controlled trials and quasi-experimental studies with a control group (usual care or enhanced usual care) conducted in Organization for Economic Co-operation and Development (OECD) member countries and published until 2016. Results Thirty-one interventions were identified, the majority of which were conducted i…
Early urinary sodium trajectory and risk of adverse outcomes in acute heart failure and renal dysfunction.
2021
Introduction and objectives: Urinary sodium (UNa+) has emerged as a useful biomarker of poor clinical outcomes in acute heart failure (AHF). Here, we sought to evaluate: a) the usefulness of a single early determination of UNa+ for predicting adverse outcomes in patients with AHF and renal dysfunction, and b) whether the change in UNa+ at 24 hours (Delta UNa24 h) adds any additional prognostic information over baseline values. Methods: This is a post-hoc analysis of a multicenter, open-label, randomized clinical trial (IMPROVE-HF) (ClinicalTrials.gov NCT02643147) that randomized 160 patients with AHF and renal dysfunction on admission to a) the standard diuretic strategy, or b) a carbohydra…
Das Werk der inneren Uhr Zur Neuroanatomie des circadiauen Systems der S�uger
1993
Many aspects of mammalian life exhibit distinct alterations throughout the 24-h cycle. Morphological, physiological, and biochemical parameters display circadian rhythms which are thought to be generated by an endogenous pacemaker and regulated by environmental factors. The morphological substrates of the endogenous circadian system have been studied extensively during the last two decades. Although knowledge is far from complete, there is general agreement that the pathways involved consist mainly of retina, hypothalamus, spinal cord, sympathetic trunk, and pineal gland. This review characterizes the anatomical structures and tracts responsible for generation and maintenance of circadian r…
Electrophysiology of the Guinea-pig Pineal Organ: Sympathetic Influence and Different Reactions to Light and Darkness
1979
Publisher Summary Recent electrophysiological studies have shown that the guinea-pig pineal organ comprises two main categories of intrinsic cells, which are (a) pinealocytes which are predominantly influenced by central commissural fibers and (b) pinealocytes which are exclusively influenced by peripheral sympathetic fibers. The first group comprises spontaneously active cells which respond to olfactory, acoustic and short-term optic stimuli respectively. After sympathectomy their spontaneous activity is diminished but not suppressed. The second group comprises spontaneously active cells, which do not respond to short-term sensory stimulation and whose activity depends on the environmental…
Sympathetic Overactivity and 24-Hour Blood Pressure Pattern in Hypertensives with Chronic Renal Failure
1995
In order to assess the activity of the sympathetic system and to evaluate the 24-h blood pressure pattern in hypertensives with chronic renal failure (CRF), 12 CRF patients and 16 essential hypertensives (EHs) were studied. In all subjects, plasma samples for catecholamines and renin activity were obtained both in the basal condition and after standing, and 24-h blood pressure monitoring (ABPM) was performed. The 24-h mean blood pressure results were quite similar between CRFs and EHs. In 50% of the CRFs, ABPM showed a nighttime decrease in diastolic BP (DBP) greater than 10%, while in the remaining 50% the ABPM indicated a nondipper blood pressure pattern. Of the 16 EHs, 4 had a nighttime …
Predictors of Progression in Hypertensive Renal Disease in Children
2004
In hypertensive renal disease in children, several risk factors influence the development and the rate of progression of renal damage, including blood pressure levels, proteinuria, lipid disorders, and genetic differences. The impact of blood pressure on renal structures, the most important of the factors, depends not only on blood pressure levels, but also on the persistence of the blood pressure levels over time, mainly during the hours when the patient is resting or sleeping. Abnormal circadian variability is frequently observed in patients with renal damage, and nocturnal blood pressure reduction should be a major therapeutic objective to protect against a decline in renal function. Pro…