The removal of the tetra-azo dye Direct Black 22 (DB22) using the microalga was evaluated in the present study, aiming to understand the contribution of different processes (biodegradation, photodegradation, and adsorption) in the removal of this contaminant. The growth and morphological characteristics of were not affected by the presence of the dye in the reaction medium. The efficiency of dye removal was 62.
View Article and Find Full Text PDFMelatonin is an indolamine secreted to circulation by the pineal gland according to a circadian rhythm. Melatonin levels are higher during nighttime, and the principal function of this hormone is to organize the temporal night and day distribution of physiological adaptive processes. Besides hormonal pineal production, melatonin is synthesized in various organs and tissues like the ovaries or the placenta for local utilization.
View Article and Find Full Text PDFThe light/dark cycle is the main external cue to synchronize the human biological clock. Modern lifestyles typically lead to less daylight exposure and blunted 24 h-amplitude. We evaluated the association of outdoor daylight exposure (frequency, duration, regularity and shift) with chronotype estimated by sleep phase, regularity of routines, sleep, well-being (WHO-5), and depressive symptoms (PHQ-9), in a sample of 1,095 participants (81.
View Article and Find Full Text PDFAmong the public health recommendations for supporting mental health during the COVID-19 pandemic, many strategies had an impact on biological rhythms, like sleep hygiene, physical exercise and healthy eating habits. Considering the known relationship between circadian organization and mental health, our aim was to test the association between behavioral regularity and mental health, and its interaction with chronotype, in a large sample surveyed in Brazil. We collected longitudinal data using online questionnaires that assessed sociodemographic characteristics, behavioral routines, mental health (PHQ-9, GAD-7, WHO-5 scales), and chronotype estimation based on midpoint of sleep on free days - MSF (μMCTQ), in a sample of 1390 participants (81% females).
View Article and Find Full Text PDFThis review summarizes data related to the potential importance of the ubiquitously functioning antioxidant, melatonin, in resisting oxidative stress and protecting against common pathophysiological disorders that accompany implantation, gestation and fetal development. Melatonin from the maternal pineal gland, but also trophoblasts in the placenta, perhaps in the mitochondria, produce this molecule as a hedge against impairment of the uteroplacental unit. We also discuss the role of circadian disruption on reproductive disorders of pregnancy.
View Article and Find Full Text PDFNumerous physiological and behavioral processes in living organisms exhibit strong rhythmicity and are regulated within a 24-hour cycle. These include locomotor activity and sleep patterns, feeding-fasting cycles, hormone synthesis, body temperature, and even mood and cognitive abilities, all of which are segregated into different phases throughout the day. These processes are governed by the internal timing system, a hierarchical multi-oscillator structure conserved across all organisms, from bacteria to humans.
View Article and Find Full Text PDFObjective: Herein, we evaluated pinealectomy-induced melatonin absence to determine its effects on craniofacial and dental development in the offspring.
Design: Female Wistar rats in three groups, i.e.
Pineal gland secretes the hormone melatonin at night with a circadian rhythm. The synthesis and secretion of melatonin are stimulated at night by norepinephrine released by sympathetic postganglionic neurons projecting from the superior cervical ganglia. Norepinephrine simultaneously activates α- and β-adrenoceptors, triggering melatonin synthesis.
View Article and Find Full Text PDFMethods Mol Biol
October 2022
Pineal microdialysis is characterized by the real-time monitoring of melatonin, neurotransmitters, metabolites, and other compounds released by the pineal gland throughout 24 h. It is a technique with great advantages that allows in vivo study of the ongoing pineal gland metabolism. In this chapter, we describe the entire process of pineal microdialysis that includes probe manufacturing, surgical procedure for its implantation, and the sample collection process.
View Article and Find Full Text PDFThe pinealectomy technique consists of the surgical removal of the superficial pineal gland. This procedure allows the ablation of circulating indoles produced by this gland. Withdrawal of systemic melatonin, a pineal hormone, affects animal circadian rhythms and induces several physiological changes that are the subject of many investigations.
View Article and Find Full Text PDFMelatonin is synthesized and secreted by the pineal gland in mammals. Its synthesis is triggered at night by norepinephrine released in the interstices of the gland. This nocturnal production is dependent on the transcription, translation, and/or activation of the enzymes arylalkylamine-N-acetyltransferase (AANAT), acetylserotonin O-methyltransferase (ASMT), and tryptophan hydroxylase (TPH).
View Article and Find Full Text PDFObjectives: The emergence of the coronavirus disease 2019 (COVID-19) pandemic and subsequent lockdowns and social distancing measures adopted worldwide raised questions about the possible health effects of human social isolation.
Methods: We conducted a systematic review on PubMed, Scopus, and Embase electronic databases using terms related to human social isolation - defined as the isolation of an individual from regular routines and usual social contact - and psychological stress, searching for simulated or naturalistic isolation environments. We present the main results, as well as the validity and limitations of each model.
A large research portfolio indicates that an activated renal renin-angiotensin system or a deficit on melatonin is associated with several cardiovascular pathologies. In this observational clinical study, we hypothesized that alterations in urinary melatonin or angiotensinogen levels may be altered in two common conditions, preeclampsia and gestational diabetes. Our study's primary objective was to assess melatonin and angiotensinogen as novel disease biomarkers detectable and quantifiable in the urine of pregnant women with or without pregnancy complications.
View Article and Find Full Text PDFObjective: To assess the adherence to a set of evidence-based recommendations to support mental health during the coronavirus disease 2019 (COVID-19) pandemic and its association with depressive and anxiety symptoms.
Methods: A team of health workers and researchers prepared the recommendations, formatted into three volumes (1: COVID-19 prevention; 2: Healthy habits; 3: Biological clock and sleep). Participants were randomized to receive only Volume 1 (control), Volumes 1 and 2, Volumes 1 and 3, or all volumes.
Objective: To analyze the underdiagnosis of COVID-19 through nowcasting with machine learning in a Southern Brazilian capital city.
Methods: Observational ecological design and data from 3916 notified cases of COVID-19 from April 14th to June 2nd, 2020 in Florianópolis, Brazil. A machine-learning algorithm was used to classify cases that had no diagnosis, producing the nowcast.
Melatonin, an indolamine mainly released from the pineal gland, is associated with many biological functions, namely, the modulation of circadian and seasonal rhythms, sleep inducer, regulator of energy metabolism, antioxidant, and anticarcinogenic. Although several pieces of evidence also recognize the influence of melatonin in the reproductive physiology, the crosstalk between melatonin and sex hormones is not clear. Here, we review the effects of sex differences in the circulating levels of melatonin and update the current knowledge on the link between sex hormones and melatonin.
View Article and Find Full Text PDFMol Plant Microbe Interact
May 2021
Plant-growth-promoting bacteria (PGPB) stimulate plant growth through diverse mechanisms. In addition to biological nitrogen fixation, diazotrophic PGPB can improve nutrient uptake efficiency from the soil, produce and release phytohormones to the host, and confer resistance against pathogens. The genetic determinants that drive the success of biological nitrogen fixation in nonlegume plants are understudied.
View Article and Find Full Text PDFThe endocrine pancreas of pregnant rats shows evident plasticity, which allows the morphological structures to return to the nonpregnant state right after delivery. Furthermore, it is well-known the role of melatonin in the maintenance of the endocrine pancreas and its tropism. Studies indicate increasing nocturnal serum concentrations of maternal melatonin during pregnancy in both humans and rodents.
View Article and Find Full Text PDFThe plant rhizosphere harbors a diverse population of microorganisms, including beneficial plant growth-promoting bacteria (PGPB), that colonize plant roots and enhance growth and productivity. In order to specifically define bacterial traits that contribute to this beneficial interaction, we used high-throughput transposon mutagenesis sequencing (TnSeq) in two model root-bacterium systems associated with : DQS4 and SmR1. This approach identified ∼100 significant genes for each bacterium that appeared to confer a competitive advantage for root colonization.
View Article and Find Full Text PDFAims: Investigate the role of melatonin on the regulation of body temperature in aged animals that have impaired melatonin production.
Material And Methods: Aged Male Wistar rats were randomly assigned to the following groups: 1) control (vehicle added to the water bottles during the dark phase) and 2) melatonin-treated (10 mg/kg melatonin added to the water bottles during the dark phase). Before and after 16 weeks of vehicle or melatonin treatment, control group and melatonin-treated animals were acutely exposed to 18 °C for 2 h for an acute cold challenge and thermal images were obtained using an infrared camera.
Gen Comp Endocrinol
January 2021
Pregnancy and lactation are reproductive processes that rely on physiological adaptations that should be timely and adequately triggered to guarantee both maternal and fetal health. Pineal melatonin is a hormone that presents daily and seasonal variations that synchronizes the organism's physiology to the different demands across time through its specific mechanisms and ways of action. The reproductive system is a notable target for melatonin as it actively participates on reproductive physiology and regulates the hypothalamus-pituitary-gonads axis, influencing gonadotropins and sexual hormones synthesis and release.
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