The Experts below are selected from a list of 144 Experts worldwide ranked by ideXlab platform

M. E. Diatroptov - One of the best experts on this subject based on the ideXlab platform.

  • Infradian Rhythm in proliferative activity of a culture of embryonic fibroblast like cells from c57bl 6 mice
    Bulletin of Experimental Biology and Medicine, 2020
    Co-Authors: M. A. Diatroptova, E. A. Ponomarenko, M. E. Diatroptov
    Abstract:

    We studied daily dynamics of proliferative activity of embryonic fibroblast-like cells in culture during the logarithmic growth phase. Daily increase in cell count in the culture showed a 4-day Rhythm that persisted over 3 weeks of culturing. In cultures from different animals, the phase of this Rhythm was synchronous and did not depend on the moment of cell isolation. It can be hypothesized that the 4-day bioRhythm of proliferative activity of embryonic fibroblast-like cells in culture is determined by external environmental factors, probably of electromagnetic nature.

  • Infradian Rhythm in Proliferative Activity of a Culture of Embryonic Fibroblast-Like Cells from C57BL/6 Mice
    Bulletin of Experimental Biology and Medicine, 2020
    Co-Authors: M. A. Diatroptova, E. A. Ponomarenko, M. E. Diatroptov
    Abstract:

    We studied daily dynamics of proliferative activity of embryonic fibroblast-like cells in culture during the logarithmic growth phase. Daily increase in cell count in the culture showed a 4-day Rhythm that persisted over 3 weeks of culturing. In cultures from different animals, the phase of this Rhythm was synchronous and did not depend on the moment of cell isolation. It can be hypothesized that the 4-day bioRhythm of proliferative activity of embryonic fibroblast-like cells in culture is determined by external environmental factors, probably of electromagnetic nature.

  • Ultradian and Infradian Rhythms in the Dynamic of Testosterone Concentration in the Serum of the White-Breasted Hedgehog Erinaceus roumanicus
    Scientific Reports, 2020
    Co-Authors: Marina  ;v. Rutovskaya, A. M. Kosyreva, M. E. Diatroptov
    Abstract:

    The aim of the study was to identify ultradian (intraday) and Infradian (multi-day) Rhythms in the dynamics of testosterone concentration in the blood serum of white-breasted hedgehogs. Blood sampling was performed from the femoral veins of 12 male hedgehogs. We found ultradian Rhythms of testosterone on both sampling dates—March 7–8 (a day length of 11 hours and 15 minutes) and May 10–11 (a day length of 16 hours). An 8-hour Rhythm of testosterone concentration has been established. The acrophases were at the same times in both photoperiods and thus independent of sunset times. The study of the Infradian Rhythms of testosterone was daily carried out on May 22—June 3, at 07:40 to 08:50 and from June 27 to July 7, at 16:15–16:50. It revealed an Infradian Rhythm of the testosterone concentration with a period of 4-days in both the morning and the evening sampling. According to our previous investigation, the Infradian Rhythms of testosterone among individual hedgehogs, rodents and primates have the same period. That indicates the common mechanisms for their formation. In case of experimental studies, the phase of ultradian and Infradian bioRhythms will need to be taken into account because the testosterone concentration in acrophase is 2–4 times higher than in bathyphase.

  • Infradian Rhythms of Resistance to a Dissociative Anesthetic in Wistar Male Rats under Normal Conditions and After Surgical Removal of the Adrenal Glands and Testes
    Bulletin of Experimental Biology and Medicine, 2019
    Co-Authors: D. Sh. Dzalilova, M. A. Diatroptova, V. A. Mkhitarov, M. E. Diatroptov
    Abstract:

    Daily dynamics of changes in the latency of a response to dissociative anesthetic tiletamine (time from injection to ataxia) was studied in mature Wistar rats. Both intramuscular and intravenous administration of the anesthetic was associated with 4-day oscillations of the latent period synchronous with the dynamics of changes in the concentration of glucocorticoid hormones. The period and phases of the Infradian Rhythm of resistance to the anesthetic remained unchanged after removal of both adrenal glands and testes and administration of corticosterone synthesis blocker trilostane diminishing the 4-day cycle of changes in corticosterone level. Therefore, hormones of the adrenal glands and testes do not play the key role in the mechanisms of formation of the 4-day Infradian Rhythm.

  • An Infradian Rhythm of changes in the thyroxine level and related periodicity in feather replacement during passerine bird molting
    Biology Bulletin Reviews, 2014
    Co-Authors: M. E. Diatroptov
    Abstract:

    The blood serum thyroxine and corticosterone levels of molting starlings ( Sturnus vulgaris ) were determined daily by enzyme immunoassay over 15 days. A 3-day Rhythm for changes in the thyroxine content and a 4-day Rhythm for corticosterone were observed, taking place synchronously in different individuals. The beginning of new flight feather growth coincided with maximal thyroxine concentration in the blood serum and also displayed a 3-day periodicity. A 3-day Rhythm was also observed in the feather replacement dynamics of free-living passerines ( Passer montanus , Parus major , and Chloris chloris ). This Rhythm was synchronous in the examined species, although they differed in the timing of their postnuptial molt. A synchronous manifestation of a 3-day Rhythm of changes in the thyroxine level and feather replacement by molting in individuals of both the same and different passerine species has been observed.

Chin Moi Chow - One of the best experts on this subject based on the ideXlab platform.

  • The periodicity of sleep duration – an Infradian Rhythm in spontaneous living
    Nature and science of sleep, 2013
    Co-Authors: Shi Ngar Wong, Mark Halaki, Chin Moi Chow
    Abstract:

    The sleep-wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.

  • the periodicity of sleep duration an Infradian Rhythm in spontaneous living
    Nature and Science of Sleep, 2013
    Co-Authors: Shi Ngar Wong, Mark Halaki, Chin Moi Chow
    Abstract:

    The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.

Francesco Dentali - One of the best experts on this subject based on the ideXlab platform.

  • Seasonal and monthly variability in the incidence of venous thromboembolism. A systematic review and a meta-analysis of the literature.
    Thrombosis and haemostasis, 2011
    Co-Authors: Francesco Dentali, Walter Ageno, Elena Rancan, Alberto V Donati, Luca Galli, Alessandro Squizzato, Achille Venco, Pier Mannuccio Mannucci, Roberto Manfredini
    Abstract:

    Many studies showed that the occurrence of cardiovascular and cerebrovascular events exhibits a seasonal and monthly variation. Evidences of a seasonal and monthly variation in the incidence of venous thromboembolism (VTE) are more conflicting. We conducted a systematic review and a meta-analysis of the literature to assess the presence of an Infradian Rhythm of this disease. MEDLINE and EMBASE databases were searched up to January 2010. Monthly and seasonal variation in the incidence of VTE were analysed. We included studies analysing seasonal or monthly aggregation in the incidence of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with an objective diagnosis of VTE. Two authors independently reviewed and extracted data. Seventeen studies for a total of about 35,000 patients were included. Twelve studies analysed the seasonal variation and 10 studies the monthly variation of VTE. Our results showed a significantly increased incidence of VTE in winter (chi-square 146.04, p

  • Seasonal and monthly variability in the incidence of venous thromboembolism
    Thrombosis and Haemostasis, 2011
    Co-Authors: Walter Ageno, Elena Rancan, Luca Galli, Alessandro Squizzato, Achille Venco, Roberto Manfredini, Alberto Donati, Pier Mannucci, Francesco Dentali
    Abstract:

    SummaryMany studies showed that the occurrence of cardiovascular and cerebrovascular events exhibits a seasonal and monthly variation. Evidences of a seasonal and monthly variation in the incidence of venous thromboembolism (VTE) are more conflicting. We conducted a systematic review and a meta-analysis of the literature to assess the presence of an Infradian Rhythm of this disease. MEDLINE and EMBASE databases were searched up to January 2010. Monthly and seasonal variation in the incidence of VTE were analysed. We included studies analysing seasonal or monthly aggregation in the incidence of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with an objective diagnosis of VTE. Two authors independently reviewed and extracted data. Seventeen studies for a total of about 35,000 patients were included. Twelve studies analysed the seasonal variation and 10 studies the monthly variation of VTE. Our results showed a significantly increased incidence of VTE in winter (chi-square 146.04, p <0.001), with a relative risk (RR) of VTE of 1.143 (99% CI [1.141, 1.144]), and a significantly increased incidence of VTE in January (chi-square 232.57, p <0.001) with an RR of VTE of 1.194 (99% CI 1.186, 1.203). Subgroup analyses including only idiopathic venous thromboembolic events confirmed the results of principal analyses. In conclusion, our data support the presence of an Infradian pattern in the incidence of venous thromboembolic events, with a significantly higher risk in Winter and in January. Future studies are needed to better clarify the mechanisms behind this pattern.

Shi Ngar Wong - One of the best experts on this subject based on the ideXlab platform.

  • The periodicity of sleep duration – an Infradian Rhythm in spontaneous living
    Nature and science of sleep, 2013
    Co-Authors: Shi Ngar Wong, Mark Halaki, Chin Moi Chow
    Abstract:

    The sleep-wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.

  • the periodicity of sleep duration an Infradian Rhythm in spontaneous living
    Nature and Science of Sleep, 2013
    Co-Authors: Shi Ngar Wong, Mark Halaki, Chin Moi Chow
    Abstract:

    The sleep–wake cycle is a process not only dictated by homeostatic and circadian factors but also by social and environmental influences. Thus, the total sleep time partly reflects sleep need, which is integral to the dynamics of sleep loss recovery. This study explored the nature of the observed oscillations in total sleep time in healthy adults under spontaneous living conditions. Actigraph-measured sleep data for 13 healthy young male adults were collected over 14 consecutive days and analyzed for habitual sleep duration. The total sleep time periodicity was modeled using the cosinor method for each individual across the 14 days. The findings confirm the existence of periodicity in habitual sleep duration as there were clear periodic patterns in the majority of the participants. Although exclusive to each individual, the observed oscillations may be a resultant response of homeostatic sleep need, circadian timing, and/or social and environmental influences. These findings instigate further indepth studies into the periodicity of sleep duration in healthy individuals to provide a better understanding of sleep need in short versus long sleepers, in predicting work performance, and reducing sleepiness-related accidents following shift work, and how this periodicity may impact sleep treatment outcome in clinical populations.

Roberto Manfredini - One of the best experts on this subject based on the ideXlab platform.

  • Seasonal and monthly variability in the incidence of venous thromboembolism. A systematic review and a meta-analysis of the literature.
    Thrombosis and haemostasis, 2011
    Co-Authors: Francesco Dentali, Walter Ageno, Elena Rancan, Alberto V Donati, Luca Galli, Alessandro Squizzato, Achille Venco, Pier Mannuccio Mannucci, Roberto Manfredini
    Abstract:

    Many studies showed that the occurrence of cardiovascular and cerebrovascular events exhibits a seasonal and monthly variation. Evidences of a seasonal and monthly variation in the incidence of venous thromboembolism (VTE) are more conflicting. We conducted a systematic review and a meta-analysis of the literature to assess the presence of an Infradian Rhythm of this disease. MEDLINE and EMBASE databases were searched up to January 2010. Monthly and seasonal variation in the incidence of VTE were analysed. We included studies analysing seasonal or monthly aggregation in the incidence of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with an objective diagnosis of VTE. Two authors independently reviewed and extracted data. Seventeen studies for a total of about 35,000 patients were included. Twelve studies analysed the seasonal variation and 10 studies the monthly variation of VTE. Our results showed a significantly increased incidence of VTE in winter (chi-square 146.04, p

  • Seasonal and monthly variability in the incidence of venous thromboembolism
    Thrombosis and Haemostasis, 2011
    Co-Authors: Walter Ageno, Elena Rancan, Luca Galli, Alessandro Squizzato, Achille Venco, Roberto Manfredini, Alberto Donati, Pier Mannucci, Francesco Dentali
    Abstract:

    SummaryMany studies showed that the occurrence of cardiovascular and cerebrovascular events exhibits a seasonal and monthly variation. Evidences of a seasonal and monthly variation in the incidence of venous thromboembolism (VTE) are more conflicting. We conducted a systematic review and a meta-analysis of the literature to assess the presence of an Infradian Rhythm of this disease. MEDLINE and EMBASE databases were searched up to January 2010. Monthly and seasonal variation in the incidence of VTE were analysed. We included studies analysing seasonal or monthly aggregation in the incidence of deep-vein thrombosis (DVT) and/or pulmonary embolism (PE) with an objective diagnosis of VTE. Two authors independently reviewed and extracted data. Seventeen studies for a total of about 35,000 patients were included. Twelve studies analysed the seasonal variation and 10 studies the monthly variation of VTE. Our results showed a significantly increased incidence of VTE in winter (chi-square 146.04, p <0.001), with a relative risk (RR) of VTE of 1.143 (99% CI [1.141, 1.144]), and a significantly increased incidence of VTE in January (chi-square 232.57, p <0.001) with an RR of VTE of 1.194 (99% CI 1.186, 1.203). Subgroup analyses including only idiopathic venous thromboembolic events confirmed the results of principal analyses. In conclusion, our data support the presence of an Infradian pattern in the incidence of venous thromboembolic events, with a significantly higher risk in Winter and in January. Future studies are needed to better clarify the mechanisms behind this pattern.