Impulsive Goodwin’s Oscillator Model of Endocrine Regulation: Local Feedback Leads to Multistability

Author(s):  
Zhanybai T. Zhusubaliyev ◽  
Alexander Medvedev ◽  
Anton V. Proskurnikov
1995 ◽  
Vol 73 (suppl_2) ◽  
pp. 36 ◽  
Author(s):  
Dean R Boyd ◽  
Ronald S Kensinger ◽  
Robert J Harrell ◽  
Dale E Bauman

2020 ◽  
Vol 2020 (1) ◽  
Author(s):  
Erfeng Xu ◽  
Yingrui Zhang ◽  
Yonggang Chen

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Giulia Brigante ◽  
Giorgia Spaggiari ◽  
Barbara Rossi ◽  
Antonio Granata ◽  
Manuela Simoni ◽  
...  

AbstractTrying to manage the dramatic coronavirus disease 2019 (COVID-19) infection spread, many countries imposed national lockdown, radically changing the routinely life of humans worldwide. We hypothesized that both the pandemic per se and the consequent socio-psychological sequelae could constitute stressors for Italian population, potentially affecting the endocrine system. This study was designed to describe the effect of lockdown-related stress on the hypothalamic-pituitary-thyroid (HPT) axis in a cohort of young men. A prospective, observational clinical trial was carried out, including patients attending the male infertility outpatient clinic before and after the national lockdown for COVID-19 pandemic. The study provided a baseline visit performed before and a follow-up visit after the lockdown in 2020. During the follow-up visit, hormonal measurements, lifestyle habits and work management were recorded. Thirty-one male subjects were enrolled (mean age: 31.6 ± 6.0 years). TSH significantly decreased after lockdown (p = 0.015), whereas no significant changes were observed in the testosterone, luteinising hormone, follicle-stimulating hormone, estradiol and prolactin serum levels. No patient showed TSH serum levels above or below reference ranges, neither before nor after lockdown. Interestingly, TSH variation after lockdown was dependent on the working habit change during lockdown (p = 0.042). We described for the first time a TSH reduction after a stressful event in a prospective way, evaluating the HPT axis in the same population, before and after the national lockdown. This result reinforces the possible interconnection between psychological consequences of a stressful event and the endocrine regulation.


2000 ◽  
Vol 23 (3) ◽  
pp. 409-410
Author(s):  
Gottfried Mayer-Kress

Among the metaphors used in the target article are “musical instruments,” “water waves,” and other types of mechanical oscillators. The corresponding equations have inertial properties and lead to standing waves that depend on boundary conditions. Other, physiologically relevant quantities like refractory times are not contained in the mechanical oscillator model but occur naturally, for instance, in biological forest fire metaphors.


Emotion ◽  
2005 ◽  
Vol 5 (2) ◽  
pp. 208-225 ◽  
Author(s):  
Sy-Miin Chow ◽  
Nilam Ram ◽  
Steven M. Boker ◽  
Frank Fujita ◽  
Gerald Clore

2004 ◽  
Vol 11 (2) ◽  
pp. 179-189 ◽  
Author(s):  
P E L√∏nning

The development of aromatase inhibitors for breast cancer therapy is a result of successful translational research exploring the biochemical effects of different compounds in vivo. Studies assessing plasma oestrogen levels as well as in vivo aromatase inhibition have revealed a consistent difference with respect to biochemical efficacy between the third generation compounds (anastrozole, letrozole and exemestane) and the previous, first and second generation drugs, corresponding to the improved clinical effects of these compounds as outlined in large phase III studies. Thus, endocrine evaluation has been found to be a valid surrogate parameter for clinical efficacy. Moreover, the results from these studies have added important biological information to our understanding of endocrine regulation of breast cancer. Based on the clinical results so far, aromatase inhibitors are believed to play a key role in future adjuvant therapy of postmenopausal breast cancer patients and potentially also for breast cancer prevention. Interesting findings such as the lack of cross-resistance between steroidal and non-steroidal compounds should be further explored, as this may add additional information to our understanding of breast cancer biology.


Sign in / Sign up

Export Citation Format

Share Document