Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 615
Filtrar
1.
Artículo en Inglés | MEDLINE | ID: mdl-24224144

RESUMEN

This tribute to her parents by one co-author (NDP) is the fruit of a more than a decade-long search by the senior author (FH) for the details of the lives of Bernhard and Gertraud ("Traute") Düll. These pioneers studied how space/terrestrial weather may differentially influence human mortality from various causes, the 27-day mortality pattern being different whether death was from cardiac or respiratory disease, or from suicide. FH is the translator of personal information about her parents provided by NDP in German. Figuratively, he also attempts to "translate" the Dülls' contribution in the context of the literature that had appeared before their work and after their deaths. Although the Dülls published in a then leading journal, among others (and FH had re-analyzed some of their work in a medical journal), they were unknown to academies or libraries (where FH had inquired about them). The Dülls thoroughly assembled death certificates to offer the most powerful evidence for an effect of solar activity reflected in human mortality, as did others before them. They went several steps further than their predecessors, however. They were the first to show possibly differential effects of space and/or Earth weather with respect to suicide and other deaths associated with the nervous and sensory systems vs. death from cardiac or respiratory disease as well as overall death by differences in the phase of a common 27-day cycle characterizing these mortality patterns. Furthermore, Bernhard Düll developed tests of human visual and auditory reaction time to study effects of weather and solar activity, publishing a book (his professorial dissertation) on the topic. His unpublished finding of an increased incidence of airplane crashes in association with higher solar activity was validated after his death, among others, by Tatiana Zenchenko and A. M. Merzlyi.

3.
Epidemiol Infect ; 141(10): 2173-84, 2013 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-23228468

RESUMEN

In the incidence patterns of cholera, diphtheria and croup during the past when they were of epidemic proportions, we document a set of cycles (periods), one of which was reported and discussed by A. L. Chizhevsky in the same data with emphasis on the mirroring in human disease of the ~11-year sunspot cycle. The data in this study are based on Chizhevsky's book The Terrestrial Echo of Solar Storms and on records from the World Health Organization. For meta-analysis, we used the extended linear and nonlinear cosinor. We found a geographically selective assortment of various cycles characterizing the epidemiology of infections, which is the documented novel topic of this paper, complementing the earlier finding in the 21st century or shortly before, of a geographically selective assortment of cycles characterizing human sudden cardiac death. Solar effects, if any, interact with geophysical processes in contributing to this assortment.


Asunto(s)
Cólera/epidemiología , Crup/epidemiología , Difteria/epidemiología , Pandemias/estadística & datos numéricos , Análisis de Varianza , Fenómenos Cronobiológicos , Humanos , India/epidemiología , Federación de Rusia/epidemiología , Actividad Solar
4.
Scr Med (Brno) ; 83(1): 5-15, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21603087

RESUMEN

Countering the trend in specialization, we advocate the trans-disciplinary monitoring of blood pressure and heart rate for signatures of environmental cyclic and other variabilities in space as well as terrestrial weather on the one hand, and for surveillance of personal and societal health on the other hand. New rules (if confirmed novel laws) emerge as we recognize our inheritance from the cosmos of cycles that constitute and characterize life and align them with inheritance from parents. In so doing, we happen to follow the endeavors of Gregor Mendel, who recognized the segregation and independent assortment of what became known as genes. Circadians, rhythms with periods, τ, between 20 and 28 hours, and cycles with frequencies that are higher (ultradian) or lower (infradian) than circadian, are genetically anchored. An accumulating long list of very important but aeolian (nonstationary) infradian cycles, characterizing the incidence patterns of sudden cardiac death, suicide and terrorism, with drastically different τs, constitutes the nonphotic (corpuscular emission from the sun, heliogeomagnetics, ultraviolet flux, gravitation) Cornélissen-series.

5.
Hist Geo Space Sci ; 1(2): 49-61, 2010 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-21547003

RESUMEN

In the late 19th century, Charles Egeson, a map compiler at the Sydney Observatory, carried out some of the earliest research on climatic cycles, linking them to about 33-year cycles in solar activity, and predicted that a devastating drought would strike Australia at the turn of the 20th century. Eduard Brückner and William J. S. Lockyer, who, like Egeson, found similar cycles, with notable exceptions, are also, like the map compiler, mostly forgotten. But the transtridecadal cycles are important in human physiology, economics and other affairs and are particularly pertinent to ongoing discusions of climate change. Egeson's publication of daily weather reports preceded those officially recorded. Their publication led to clashes with his superiors and his personal life was marked by run-ins with the law and, possibly, an implied, but not proven, confinement in an insane asylum and premature death. We here track what little is known of Egeson's life and of his bucking of the conventional scientific wisdom of his time with tragic results.

6.
Scr Med (Brno) ; 83(1): 16-32, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-21566725

RESUMEN

Three spectral components with periods of about (~) 0.41, ~0.5 and ~1.0 year had been found with serially independent sampling in human circulating melatonin. The time series consisted of around-the-clock samples collected for 24 hours at 4-hour intervals from different patients over several years. Some of these components had been found to be circadian stage-dependent, the daytime measurements following mostly a circannual variation, whereas a half-year characterized the nighttime samples. The latter were incorporated into a circasemiannual map. The relative brevity of the series prevented a check for the coexistence of all three spectral components, even if each component seemed to have a raison d'être. In time series of transdisciplinary data, a 1.00-year synchronized component is interpreted as representing the seasons. The half-year may qualify the circannual waveform, but it is also a signature of geomagnetics. An ~0.41-year (~5-month) component is the signature of solar flares. It has been called a cis-half-year (cis = on this side of a half-year) and may be detected only intermittently. Charles L. Wolff predicted the existence, among others, of ~0.42- and ~0.56-year components as beat periods of rotations at different solar latitudes.The multiple components characterizing circulating melatonin could also be found in a (to our knowledge unique) data set of a clinically healthy scientist (RBS). Herein, we focus on vascular data self-measured by RBS as he aged from ~20 to ~60 years. A multi-component model consisting of cosine curves with periods of 0.41, 0.50 and 1.00 year was fitted to weekly means of systolic (S) and diastolic (D) blood pressure (BP) and heart rate (HR) collected ~5 times a day over 39 years by RBS. All three components can coexist for a while, although all of them are nonstationary in their characteristics and come and go by the criterion of statistical significance.Intermittently, BP and HR are synchronized selectively with one or the other aspect of RBS' physical environment, namely the seasons (at ~1.0 year), earth magnetism (at ~0.5 year) and/or solar flares (at ~0.42 year). Cosmic-biotic transfer of information, albeit hardly of energy (the biospheric amplitudes are very small) may be mediated in this set of frequency windows. As found earlier, RBS' circulation is also frequency-trapped environmentally in multidecadal windows, HR being locked into the transtridecadal Brückner, or rather Brückner-Egeson-Lockyer, BEL sunspot and terrestrial weather cycle, while his BP follows Hale's didecadal cycle in the changing polarity of sunspots.The ~0.41-year HR cycle may be associated with changes in solar flares, the cis-half-year amplitude of HR showing a cross-correlation coefficient of 0.79 with the total solar flare index (from both solar hemispheres) at a lag of ~3.2 years. The superposed time courses of these two variables indicate the presence of a shared Horrebow-Arago-Schwabe sunspot cycle of ~11 years, the cis-half-year in HR being more prominent after the total solar flare index reaches its ~11-year peak. Differences in the time-varying behavior of BP vs. HR are also described.

7.
Scr Med (Brno) ; 83(1): 38-40, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-22267948
8.
J Hum Hypertens ; 24(3): 165-74, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-19571828

RESUMEN

To compare the circadian variation of blood pressure (BP) between patients with intra-cerebral haemorrhage (ICH) and with cerebral infarction (CI), around-the-clock BP measurements were obtained from 89 hypertensive patients with ICH, from 63 patients with CI and from 16 normotensive volunteers. The single and population-mean cosinor yielded individual and group estimates of the MESOR (Midline Estimating Statistic Of Rhythm, a rhythm-adjusted mean value), circadian double amplitude and acrophase (measures of extent and timing of predictable daily change). Comparison shows that without any difference in BP MESOR, the circadian amplitude of systolic (S) BP was larger in ICH than CI patients (P<0.001), and both groups differed from the healthy volunteers in BP MESOR and pulse pressure (P<0.001) and in the circadian amplitude of SBP (P<0.005). The smaller population circadian amplitude of diastolic (D) BP of the ICH group (P=0.042) is likely related to a larger scatter of individual circadian acrophases in this group as compared with that in the other two groups, an inference supported by a smaller day-night ratio of DBP for ICH vs CI patients (P=0.007). Heart rate (HR) variability, gauged by the standard deviation (SD), was decreased in both patient groups as compared with that in healthy controls, more so among ICH than CI patients (P=0.025). Thus, patients with ICH had a higher incidence of abnormal circadian characteristics of BP than patients with CI, the major differences relating to a larger circadian amplitude of SBP, a smaller HR-SD, and a larger incidence of odd circadian acrophases of DBP.


Asunto(s)
Presión Sanguínea , Isquemia Encefálica/fisiopatología , Ritmo Circadiano , Frecuencia Cardíaca , Hemorragias Intracraneales/fisiopatología , Accidente Cerebrovascular/fisiopatología , Anciano , Pueblo Asiatico/estadística & datos numéricos , Isquemia Encefálica/etnología , China/epidemiología , Femenino , Humanos , Incidencia , Hemorragias Intracraneales/etnología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Accidente Cerebrovascular/etnología
9.
Clin Ter ; 160(5): 375-86, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19997684

RESUMEN

Col. Eugene L. (Gene) Kanabrocki, PhD, commanding officer of the 361st Medical Laboratory of the U.S. Army Reserve, together with Col. Lawrence E. (Larry) Scheving, Professor at the University of Arkansas, initiated in May 1969 a linked cross-sectional (hybrid) study at Fort Sam Houston, TX, to examine the oscillatory (circadian) nature of many physiological variables in a group of 13 army men, 22-28 years of age, anticipating that such data would serve, as indeed they did, as time-specified reference values in future investigations of health and aging. In the initial study, 36 variables were examined around the clock in observations at 3-hour intervals. In subsequent 24-hour profiles, mapped in May of 1971 (mostly on new, young subjects, and not officially part of the Aging Project), 1979, 1988, 1993, 1998 and 2003, additional subjects and variables were included. The follow-up studies were conducted at the Hines VA Medical Center in Hines, Illinois. Of the original 13 subjects, four were measured in all 6 studies and another four in 5 of the 6 studies. Three of the eight became diabetic (Type II) and three had vascular circulatory problems. Presently, a bank of circadian data for 187 medically relevant variables of blood (plasma or serum), saliva, urine, vital signs and other variables on the same subjects covers a span of 34 years. Dr. Robert B. Sothern (RBS), of the University of Minnesota, USA, the major analyst of Gene's investigations, in addition to being an add-on subject as he was in three studies, set up the half-hourly monitoring of blood pressure (BP) and heart rate (HR) in the 2003 study that yielded the data suggesting that the standard deviations (SD) of systolic (S) and diastolic (D) BP and HR are infl uenced by a magnetic storm. Since the standard deviation rather than the amplitude of a vascular spectral component was affected, we may be dealing with a stochastic rather than frequency window-dependent resonance with a magnetic storm. Gene and RBS also found (p< 0.08) an about-decadal signature of solar activity in long-acting natriuretic peptide (LANP), vessel dilator (VSDL), insulin, LH, prolactin, T3 uptake and, most importantly, in melatonin (p=0.004), noted solely to constitute a stimulus for follow-up studies, even when resonance occurs in an anticipated Horrebow-Schwabe circadecadal window gauged by relative sunspot (Wolf) numbers and involves many endocrine variables, as anticipated on the basis of independent evidence in melatonin and cortisol. The wealth of circadian information collected in these studies by Gene constitutes a treasure trove of unique advances in the battle of the normal range, with solid contributions also by Prof. Germaine Cornélissen of the University of Minnesota, USA, and by Prof. Ramon C. Hermida of the University of Vigo, Spain.


Asunto(s)
Ritmo Circadiano , Historia del Siglo XX , Historia del Siglo XXI , Humanos , Estados Unidos , Guerra
10.
Clin Ter ; 160(2): e13-24, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19452095

RESUMEN

An increase in the circadian amplitude (A) of blood pressure (BP) had been reported to precede a rise in the circadian BP average (MESOR, M), as pre-hypertension in the stroke-prone Okamoto rat. In humans, children with a positive family history of high BP and/or related cardiovascular disease had, on average, a larger BP-A than children with a negative family history, and an elevated BP-A was associated with intermediate values of the left ventricular mass index (LVMI), whereas an elevation in BP-M was only observed for larger LVMI values. Against this background, with 24-hour ambulatory monitoring (ABPM) interpreted chronobiologically, Pietro Cugini (University La Sapienza of Rome, Italy) has reported an elevation of both the circadian BP-M and BP-A as occurring with a minimal change (hypertensive) retinopathy. He determined by cosinor the extent of predictable BP change within a day as BP-2A, estimated by the least squares fit of a 24-hour cosine curve to the data. As compared to controls without retinopathy, he found a retinal end-organ involvement associated with average systolic (S) / diastolic (D) BP-Ms of 124/76 vs. 112/72 mmHg, with corresponding SBP/DBP-As of 12/10 vs. 8/7 mmHg. We refer to "Cugini's syndrome", suggesting the need for clarification, preferably in longitudinal studies, of any generalizable sequence in end-organ involvement, that may occur in the course of the development of some human Vascular Variability Disorders (VVDs) of unknown etiology, that include an elevation of the circadian BP-A and/or BP-M, concomitantly or separately in a sequence with the BP-A increase preceding that in BP-M, as in models of high BP in the rat or vice versa. Seven-day half-hourly or hourly around-the-clock monitoring of BP and HR variability interpreted chronobiologically, C-ABPM, as a minimum, is recommended for routine medical care to detect VVDs consisting of 1. MESOR-hypertension, MH; 2. Circadian Hyper-Amplitude-Tension, CHAT (BP overswing); 3. odd timing of the circadian rhythm of BP but not that of HR; 4. above-threshold pulse pressure; and/or 5. below-threshold HR variability. All conditions are best determined by 24-hour/7-day or, when abnormality is detected, longer C-ABPM. Eventually, all conditions will need to be assessed in the light of reference values from gender- and age-matched peers, as is now the case for the fi rst three VVDs listed above. When C-ABPM is not practicable, a 7-day series of 3-hourly manual self-measurements during waking (and one measurement about mid-sleep) (C-MBPM) is recommended. When continuous monitoring becomes possible, as it is within the state of the science, detecting Cugini's syndrome will also become possible with the clarification as to whether any change in BP-M and/or BP-A occurs concomitantly or sequentially, with changes in BP-A anticipated to precede changes in BP-M.


Asunto(s)
Presión Sanguínea/fisiología , Ritmo Circadiano/fisiología , Hipertensión/fisiopatología , Enfermedades de la Retina/etiología , Algoritmos , Animales , Monitoreo Ambulatorio de la Presión Arterial , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Ratas , Síndrome
11.
Clin Ter ; 160(2): ep25-34, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19452096

RESUMEN

BACKGROUND AND PURPOSE: Molecular clocks present in organs and individual cells throughout the body are central for the temporal coordination of internal biological processes among themselves and with external environmental cycles. Relationships between circadian clocks and normal vs. abnormal organ physiology can have significant impact relevant to not only cardiovascular health, but also to the general treatment and prognosis of human disease. Chronobiological statistical procedures were applied to previously published circadian clock gene (CG) mRNA expression data which were described macroscopically, in order to establish rhythm probability and point and interval estimates for amplitudes and acrophases for 14 clock and clock-controlled genes in mouse heart. CGs in general and their importance to cardiovascular health, as well as to diagnosis and treatment of human disease, are reviewed. MATERIALS AND METHODS: Organs from male Balb/c mice were harvested every 4 h for 24-h on the 3rd day in constant darkness and analyzed by quantitative real-time reverse transcription-polymerase chain reaction for 14 CGs: mPer1, mPer2, mPer3, mCry1, mCry2, mBmal1, mCK1delta, mCK1epsilon, mClock, mDbp, mNpas2, mRev-erbalpha, mRev-erbbeta, and mTim. Relative mRNA levels normalized to corresponding G3-PDH RNA levels were re-expressed as percent of the highest value for each CG and analyzed for circadian time effect by one-way ANOVA and for circadian rhythm characteristics by single cosinor. RESULTS: 12 CGs showed a significant time-effect at p < or = 0.031 by ANOVA and 13 CGs displayed a significant 24-h rhythm at p < or = 0.011 by cosinor analysis. Five CGs (mRev-erbalpha, mDbp, mPer1, mRev-erbbeta, mPer3) reached their maxima late in the presumed resting span, 5 CGs (mPer2, mCry2, mCK1delta, mCK1epsilon, mCry1) reached their peak early in the presumed activity span, while 3 genes (mBmal1, mClock, mNpas2) reached their peak late in the presumed activity span. CONCLUSIONS: Macroscopic inspection concluded a robust circadian rhythm in 8 CGs, while cosinor analysis detected significance in 13 of 14 CGs (the developmental gene mTim is usually not circadian rhythmic) and computed point and interval estimates for amplitudes and acrophases, useful in making future objective comparisons among organisms and conditions. Information on statistically-determined rhythm characteristics of the molecular clock presents new avenues for diagnosis and therapeutic intervention in conditions where disturbance of circadian CG expression is an important cause of morbidity in chronic illnesses and diseases with a strong circadian component, including coronary vascular disease.


Asunto(s)
Ritmo Circadiano/genética , Regulación de la Expresión Génica , Factores de Transcripción/genética , Transcripción Genética , Animales , Proteínas CLOCK , Regulación de la Expresión Génica/efectos de la radiación , Masculino , Ratones , Ratones Endogámicos BALB C , Microscopía/métodos , Miocardio/metabolismo , ARN Mensajero/biosíntesis , ARN Mensajero/genética , Transactivadores/biosíntesis , Transactivadores/genética , Factores de Transcripción/biosíntesis , Transcripción Genética/efectos de la radiación
13.
Neurotox Res ; 13(2): 85-96, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18515211

RESUMEN

While certain circadian hormonal changes are prominent, their predictable assessment requires a standardization of conditions of sampling. The 24-hour rhythm in circulating corticosterone of rodents, known since the 1950s, was studied as a presumed proxy for stress on 108 rats divided into 9 groups of 6 male and 9 groups of 6 female animals sampled every 4 hours for 24 hours. In a first stress study, the "no-rhythm" (zero-amplitude) assumption failed to be rejected at the 5% probability level in the two control groups and in 16 out of the 18 groups considered. A circadian rhythm could be detected with statistical significance, however, in three separate follow-up studies in the same laboratory, each on 168 rats kept on two antiphasic lighting regimens, with 4-hourly sampling for 7 or 14 days. In the first stress study, pooling of certain groups helped the detection and assessment of the circadian corticosterone rhythm. Without extrapolating to hormones other than corticosterone, which may shift more slowly or adjust differently and in response to different synchronizers, the three follow-up studies yielded uncertainty measures (95% confidence intervals) for the point estimate of its circadian period, of possible use in any future study as a reference standard. The happenstance of a magnetic disturbance at the start of two follow-up studies was associated with the detection of a circasemiseptan component, raising the question whether a geomagnetic disturbance could be considered as a "load". Far beyond the limitations of sample size, the methodological requirements for standardization in the experimental laboratory concerning designs of studies are considered in the context of models of depression. Lessons from nature's unforeseen geomagnetic contribution and from human studies are noted, all to support the advocacy, in the study of loads, of sampling schedules covering more than 24 hours.


Asunto(s)
Trastornos Cronobiológicos/fisiopatología , Corticosterona/sangre , Depresión/fisiopatología , Campos Electromagnéticos , Estrés Fisiológico/fisiopatología , Animales , Peso Corporal , Trastornos Cronobiológicos/metabolismo , Ritmo Circadiano/fisiología , Depresión/metabolismo , Sacarosa en la Dieta/farmacología , Modelos Animales de Enfermedad , Femenino , Privación de Alimentos/fisiología , Humanos , Iluminación , Masculino , Ratas , Ratas Wistar , Actividad Solar , Estrés Fisiológico/metabolismo , Testosterona/sangre , Privación de Agua/fisiología
14.
J Hum Hypertens ; 22(9): 627-33, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18480832

RESUMEN

Blood pressure (BP) exhibits a circadian variation characterized by a morning increase, followed by a small postprandial valley and a deeper descent during nocturnal rest. Although abnormal 24-h variability (abnormal circadian variability (ACV)) predicts adverse cardiovascular disease (CVD) outcomes, a 7-day automatic ambulatory BP monitoring (ABPM) and subsequent chronobiologic analysis of the gathered data, permits identification of consistency of any abnormal circadian variation. To test whether normal overweight healthy men and women with prediabetes differed from subjects with normoglycemia in having ACV with a 7-day ABPM. Consent for a 7-day ABPM was obtained from subjects with family history of diabetes mellitus, who were participating in the screening phase for a randomized, double blind, placebo-controlled weight loss trial in prediabetics to prevent progression to diabetes mellitus. The automatic 7-day ABPM device recorded BP and heart rate every 30 min during the day and every 60 min during the night. Normoglycemic and prediabetic subjects matched for age, sex, race, BP, BMI, waist circumference and glycemic control, differed statistically significantly only in their fasting and/or 2-h postprandial serum glucose concentrations. Chronobiologically-interpreted 7-day ABPM uncovered no abnormalities in normoglycemics, whereas prediabetics had a statistically significantly higher incidence of high mean BP (MESOR-hypertension), excessive pulse pressure and/or circadian hyper-amplitude-tension (CHAT) (P<0.001). ACV detected with 7-day ABPM may account for the enhanced CVD risk in prediabetes. These findings provide a basis for larger-scale studies to assess the predictive value of 7-day ABPM over the long term.


Asunto(s)
Presión Sanguínea/fisiología , Estado Prediabético/fisiopatología , Adulto , Anciano , Glucemia/análisis , Monitoreo Ambulatorio de la Presión Arterial , Ritmo Circadiano , Diabetes Mellitus/prevención & control , Método Doble Ciego , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pérdida de Peso
15.
Scr Med (Brno) ; 80(4): 157-166, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19122770

RESUMEN

BIOCOS, the project aimed at studying BIOlogical systems in their COSmos, has obtained a great deal of expertise in the fields of blood pressure (BP) and heart rate (HR) monitoring and of marker rhythmometry for the purposes of screening, diagnosis, treatment, and prognosis. Prolonging the monitoring reduces the uncertainty in the estimation of circadian parameters; the current recommendation of BIOCOS requires monitoring for at least 7 days. The BIOCOS approach consists of a parametric and a non-parametric analysis of the data, in which the results from the individual subject are being compared with gender- and age-specified reference values in health.Chronobiological designs can offer important new information regarding the optimization of treatment by timing its administration as a function of circadian and other rhythms.New technological developments are needed to close the loop between the monitoring of blood pressure and the administration of antihypertensive drugs.

16.
Scr Med (Brno) ; 80(4): 151-156, 2007 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-19129929

RESUMEN

The aim of the study was to assess the time structure (chronome) of sudden cardiac death (SCD) in Austria. The daily incidence of SCD (ICD-10 I46.1) in Austria was obtained for the 4-year span from Jan 2002 to Dec 2005. Data were available separately for men and women. This data series was analyzed by linear-nonlinear rhythmometry. The major feature is the detection of a cis-half-year that is validated nonlinearly, the estimated period of the cis-half-year is 0.408 year (95% CI: 0.389, 0.426). It is concluded that the chronobiological analysis of sudden cardiac death in Austria showed the variability of total incidence with the period of a cis-half-year.

17.
Scr Med (Brno) ; 80(4): 175-178, 2007 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19424513

RESUMEN

Re-evaluation of all functions of baroreflex by means of a simple mathematical model of circulation was the aim of the present study. The following states are modelled: 1. Rest. 2. Immediately after baroreceptor denervation. 3. Several days after denervation. 4. Physical exercise before denervation. 5. Physical exercise several days after denervation. Despite the same cardiac contractility and the same vasodilatation in working muscles as before denervation the cardiac output is by one third lower after baroreceptor denervation. In conclusion, a model simulation revealed the common regulation of blood pressure and blood volume by baroreflex and kidneys as a primary function of baroreflex.

18.
Scr Med (Brno) ; 80(5): 191-196, 2007 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-19436776

RESUMEN

The objective of this study was to find if there was a relationship between the time when cardiovascular rehabilitation was running in the patients after myocardial infarction and an average daily value of systolic and diastolic blood pressure at 7-day ambulatory blood pressure monitoring.Systolic and diastolic pressures significantly increased in patients who underwent cardiovascular rehabilitation in the morning from 9.00 a.m. to 10.15 a.m., and significantly decreased in those who did their physical exercise in the afternoon from 1.30 p.m. to 2.45 p.m., compared to their blood pressure values on days without rehabilitation.

19.
Scr Med (Brno) ; 80(4): 179-188, 2007 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19436777

RESUMEN

The relationship between age and circadian blood pressure (BP) variation was the aim of the present study. One hundred and eighty-seven subjects (130 males, 57 females), 20-77 years old, were recruited for seven-day BP monitoring. Colin medical instruments (Komaki, Japan) were used for ambulatory BP monitoring (oscillation method, 30-minute interval between measurements). A sinusoidal curve was fitted (minimum square method) and the mean value and amplitude of the curve (double amplitude corresponds to the night-day difference) were evaluated on every day of monitoring. The average 7-day values of the mean (M) and of double amplitude (2A) for systolic BP (SBP), diastolic BP (DBP), and heart rate (HR) were determined in each subject. The mean values of M (+/-SD) for the whole group were: SBP- 127+/-8, DBP - 79+/-6 mmHg, HR - 70+/-6 bpm; of 2A: SBP - 21+/-7, DBP - 15+/-5 mmHg, HR - 15+/-6 bpm. A linear relationship between M of SBP and age (r=0.341, p< 0.001) and DBP and age (r=0.384, p<0.001) was found (difference between 20 and 77 years: SBP - 16, DBP - 12 mmHg). 2A of SBP and DBP was increasing with age up to 35 years, then the curve remained relatively flat up to 55 years (maximum at 45 years), and then it decreased again (difference between 45 and 77 years: SBP - 13mmHg, DBP - 12 mmHg). Heart rate M and 2A were age-independent. The mean values of SBP and DBP were increasing with age up to 75 years, but the night-day difference of SBP and DBP reached its maximum value at 45 years and then decreased.

20.
Scr Med (Brno) ; 80(4): 133-150, 2007 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-19710947

RESUMEN

The mapping of time structures, chronomes, constitutes an endeavor spawned by chronobiology: chronomics. This cartography in time shows signatures on the surface of the earth, cycles, also accumulating in life on the earth's surface. We append a glossary of these and other cycles, the names being coined in the light of approximate cycle length. These findings are transdisciplinary, in view of their broad representation and critical importance in the biosphere. Suggestions of mechanisms are derived from an analytical statistical documentation of characteristics with superposed epochs and superposed cycles and other "remove-and-replace" approaches. These approaches use the spontaneously changing presence or absence of an environmental, cyclic or other factor for the study of any corresponding changes in the biosphere. We illustrate the indispensability of the mapping of rhythm characteristics in broader structures, chronomes, along several or all available different time scales. We present results from a cooperative cartography of about 10, about 20, and about 50-year rhythms in the context of a broad endeavor concerned with the Biosphere and the Cosmos, the BIOCOS project. The participants in this project are our co-authors worldwide, beyond Brno and Minneapolis; the studies of human blood pressure and heart rate around the clock and along the week may provide the evidence for those influences that Mendel sought in meteorology and climatology.

SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...