Evaluation of Blue-Blocking Lenses Effects on the Melatonin Production level.

Author(s):  
Oussama Ben Abdellah ◽  
Laurent Canale ◽  
Pascal Dupuis ◽  
Bousselham Samoudi ◽  
Adel Asselman ◽  
...  
2021 ◽  
Vol 4 (1) ◽  
pp. 99-114
Author(s):  
Janaína B Garcia ◽  
Fernanda G Do Amaral ◽  
Daniela C Buonfiglio ◽  
Rafaela FA Vendrame ◽  
Patrícia L Alves ◽  
...  

The pineal gland synthesizes melatonin exclusively at night, which gives melatonin the characteristic of a temporal synchronizer of the physiological systems. Melatonin is a regulator of insulin activities centrally and also peripherally and its synthesis is reduced in diabetes.  Since monosodium glutamate (MSG) is often used to induce the type 2 diabetic and metabolic syndrome in animal models, the purpose of this work is to evaluate the potential effects of MSG given to neonates on the pineal melatonin synthesis in different aged male and female rats. Wistar rats were subcutaneously injected with MSG (4mg/g/day) or saline solution (0.9%) from the second to eighth post-natal day. The circadian profiles both melatonin levels and AANAT activity were monitored at different ages. Body weight, naso-anal length, adipose tissues weight, GTT, ITT and serum insulin levels were also evaluated. Typical obesity with the neonatal MSG treatment was observed, indicated by a great increase in adipose depots without a concurrent increase in body weight. MSG treatment did not cause hyperglycemia or glucose intolerance, but induced insulin resistance. An increase of melatonin synthesis at ZT 15 with phase advance was observed in in some animals. The AANAT activity was positively parallel to the melatonin circadian profile. It seems that MSG causes hypothalamic obesity which may increase AANAT activity and melatonin production in pineal gland. These effects were not temporally correlated with insulin resistance and hyperinsulinemia indicating the hypothalamic lesions, particularly in arcuate nucleus induced by MSG in early age, as the principal cause of the increase in melatonin production.


2019 ◽  
Vol 1 (4) ◽  
pp. 21-26 ◽  
Author(s):  
O. V. Bobko ◽  
O. V. Tikhomirova ◽  
N. N. Zybina ◽  
O. A. Klitsenko

The objective of the study is to show significance of desynchronosis laboratory markers in risk assessment of metabolic syndrome (MS) development. Materials and Methods. There were examined 98 men, aged 43-88, diagnosed with dyscirculatory encephalopathy showing one and more risk factors for development of cardiovascular diseases. They were divided into 2 groups according to the international guidelines of 2009: with MS (n = 61) and without MS (n = 37). Parameters of fats, glucose metabolism, inflammatory mediators, fat tissue metabolism markers, melatonin metabolite excretion (6-sulfatoxymelatonin) were defined in blood serum and urine. Results. The article presents data on changes in leptin, adiponectin, PAI-1, testosterone production and 6-sulfatoxymela-tonin excretion in patients with MS. There are calculated threshold values of these markers definitely increasing MS risk and logistic regression equation which allows assessing MS risk for an individual patient. Conclusion. Detected disorders of melatonin synthesis diurnal dynamics in patients with MS and interconnection between melatonin production and adiponectin, leptin, PAI-1, testosterone synthesis allow considering these parameters as desynchronosis markers significant for MS development.


2004 ◽  
Vol 15 (3) ◽  
pp. 197-204 ◽  
Author(s):  
M. Zeman ◽  
P. Pavlik ◽  
D. Lamos˘ová ◽  
I. Herichová ◽  
E. Gwinner

2013 ◽  
Vol 5 (3) ◽  
pp. 186-194 ◽  
Author(s):  
Hella Bartsch ◽  
Dieter Mecke ◽  
Hansgeorg Probst ◽  
Heinz Kupper ◽  
Eckhard Seebald ◽  
...  

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3141
Author(s):  
Aurora Laborda-Illanes ◽  
Lidia Sánchez-Alcoholado ◽  
Soukaina Boutriq ◽  
Isaac Plaza-Andrades ◽  
Jesús Peralta-Linero ◽  
...  

In this review we summarize a possible connection between gut microbiota, melatonin production, and breast cancer. An imbalance in gut bacterial population composition (dysbiosis), or changes in the production of melatonin (circadian disruption) alters estrogen levels. On the one hand, this may be due to the bacterial composition of estrobolome, since bacteria with β-glucuronidase activity favour estrogens in a deconjugated state, which may ultimately lead to pathologies, including breast cancer. On the other hand, it has been shown that these changes in intestinal microbiota stimulate the kynurenine pathway, moving tryptophan away from the melatonergic pathway, thereby reducing circulating melatonin levels. Due to the fact that melatonin has antiestrogenic properties, it affects active and inactive estrogen levels. These changes increase the risk of developing breast cancer. Additionally, melatonin stimulates the differentiation of preadipocytes into adipocytes, which have low estrogen levels due to the fact that adipocytes do not express aromatase. Consequently, melatonin also reduces the risk of breast cancer. However, more studies are needed to determine the relationship between microbiota, melatonin, and breast cancer, in addition to clinical trials to confirm the sensitizing effects of melatonin to chemotherapy and radiotherapy, and its ability to ameliorate or prevent the side effects of these therapies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ján Krahulec ◽  
Martin Šafránek

Abstract Background The aim of this study was to provide an information about the homogeneity on the level of enterokinase productivity in P. pastoris depending on different suppliers of the media components. Results In previous studies, we performed the optimisation process for the production of enterokinase by improving the fermentation process. Enterokinase is the ideal enzyme for removing fusion partners from target recombinant proteins. In this study, we focused our optimization efforts on the sources of cultivation media components. YPD media components were chosen as variables for these experiments. Several suppliers for particular components were combined and the optimisation procedure was performed in 24-well plates. Peptone had the highest impact on enterokinase production, where the difference between the best and worst results was threefold. The least effect on the production level was recorded for yeast extract with a 1.5 fold difference. The worst combination of media components had a activity of only 0.15 U/ml and the best combination had the activity of 0.88 U/ml, i.e., a 5.87 fold difference. A substantially higher impact on the production level of enterokinase was observed during fermentation in two selected media combinations, where the difference was almost 21-fold. Conclusions Results demonstrated in the present study show that the media components from different suppliers have high impact on enterokinase productivity and also provide the hypothesis that the optimization process should be multidimensional and for achieving best results it is important to perform massive process also in terms of the particular media component supplier .


2014 ◽  
Vol 40 (7) ◽  
pp. 734-754 ◽  
Author(s):  
Yoram Kroll ◽  
David Yechiam Aharon

Purpose – The purpose of this paper is to develop alternative analytical measures for the degree of operating leverage (DOL) that reflect the impact of uncertain demand shocks in the product's market on optimal production levels, sales and profits of the firm. Design/methodology/approach – The elasticity measures are constructed according to a theoretical formulation of optimal production level that corresponds to demand shocks for given predetermined levels of fixed cost. Findings – The paper suggests two main findings. First, the analytical marginal DOL is at least twice the traditional DOL depending on the structure of the shock, the production function and demand's elasticity. The traditional DOL is equal to the measure only when large-scale negative demand prompts the firm to abandon production. Second, the paper also provides an analytical measure of DOL in terms of elasticity of profit to sales rather than to production level. Both theoretically and empirically elasticity of profit to sales can be better measured and better reflects risk. Research limitations/implications – This paper should be extended to encompass multiple shocks on demand and supply while investigating the empirical multi variants distribution of the shocks. Practical implications – The model can be used by managers who are well informed about the fixed and variable costs of their firm. The model determines the mean profit- risk trade off which is an important factor in all investment decision problems. Originality/value – Surprisingly and according to the best knowledge, this paper is the first attempt in the literature for alternative analytical DOLs’ formulations that is coherent with basic economic theories of optimal production level under risk.


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