Menarche is a milestone in a woman's life as it denotes the start of reproductive capacity. Aim of this report is to review the recent developments and the current knowledge in the neuroendocrinology of pubertal onset and the factors, genetic and environmental, that influence menarcheal age. We also review the implications of early or late menarcheal age on a young woman's life.
Glucocorticoids (GCs) are essential for the maintenance of homeostasis and enable the organism to prepare for, respond to and manage stress, either physical or emotional. Cortisol, the principal GC in humans, is synthesized in the adrenal cortex. It is released in the circulation in a pulsatile and circadian pattern. GC secretion is governed by hypothalamus and pituitary. The hypothalamus senses changes in the external and internal environment that may disrupt the homeostatic balance of the organism (i.e. stressors), and responds by releasing corticotropin-releasing hormone (CRH) and arginine vasopressin (AVP) from parvocellular neurons projecting from the paraventricular nucleus to the median eminence. These neurohormones are released into the anterior pituitary where they act synergistically via specific receptors (CRH-R1 and V1B receptor, respectively) to trigger the release of the adrenocorticotropic hormone (ACTH) from the corticotrope cells into the systemic circulation. In turn, ACTH exerts its actions on the adrenal cortex via specific receptors, type 2 melanocortin receptors (MC2-R), to initiate the synthesis of cortisol, which is released immediately into the systemic circulation by diffusion. Hypothalamic CRH and AVP, pituitary ACTH and adrenal GCs comprise the hypothalamic-pituitary-adrenal (HPA) axis. In this brief review, the HPA axis and the various factors that regulate its function are described.
Purpose of Review To describe the possible neuroinvasion pathways of Severe Acute Respiratory Syndrome-related Coronavirus-2 (SARS-CoV-2), the virus responsible for the Coronavirus disease-19 (Covid-19) pandemic. Recent Findings We present data regarding the family of Coronaviruses (CoVs) and the central nervous system (CNS), and describe parallels between SARS-CoV-2 and other members of the family, which have been investigated in more depth and combine these findings with the recent advancements regarding SARS-CoV-2. Summary SARS-CoV-2 like other CoVs is neuroinvasive, neurotropic and neurovirulent. Two main pathways of CNS penetration seem to be the strongest candidates, the hematogenous and the neuronal. Τhe olfactory route in particular appears to play a significant role in neuroinvasion of coronaviruses and SARS-CoV-2, as well. However, existing data suggest that other routes, involving the nasal epithelium in general, lymphatic tissue and the CSF may also play roles in SARS-CoV-2 invasion into the CNS.
Epidemiological studies have shown several associations between asthma symptoms and dietary factors. The aim of this work was to evaluate the relationship between adherence to the Mediterranean diet and childhood asthma. A cross-sectional analysis was performed on 700 children (323 boys), 10-12 yr old, selected from 18 schools located in Athens greater area. Children and their parents completed questionnaires, which evaluated, among others, dietary habits. Asthma was defined according to ISAAC II criteria. Adherence to the Mediterranean diet was evaluated using the KIDMED score (theoretical range 0-12). Higher KIDMED score corresponds to greater adherence to the Mediterranean diet. Greater adherence to the Mediterranean diet was inversely associated with ever had wheeze (p = 0.001), exercise wheeze (p = 0.004), ever had diagnosed asthma (p = 0.002) and with any asthma symptoms (p < 0.001). One-unit increase in the KIDMED score was associated with 14% lower likelihood of having asthma symptoms (odds ratio = 0.86, 95% confidence interval 0.75-0.98), after adjusting for various confounders. No significant associations were found between asthma symptoms and consumption of fruits (p = 0.25), vegetables (p = 0.97), legumes (p = 0.76), cereals (p = 0.71), dairy (p = 0.61), salty snacks (p = 0.53), or margarine/butter (p = 0.42) consumption, while increased fish and meat intake was associated with less asthma symptoms (p = 0.04 and p = 0.01, respectively). Our findings suggest an inverse relationship between level of adherence to the Mediterranean diet and prevalence of asthma in school-aged children.
Mutations within HESX1 are a rare cause of SOD and hypopituitarism. However, the large number of familial patients with SOD in whom no mutations were identified is suggestive of an etiological role for other genetic factors. Furthermore, we have found that within our cohort SOD is associated with a reduced maternal age compared with isolated defects of the hypothalamopituitary axis.
The stress system co‐ordinates the adaptive responses of the organism to stressors of any kind. Inappropriate responsiveness may account for increased susceptibility to a variety of disorders, including asthma. Accumulated evidence from animal models suggests that exogenously applied stress enhances airway reactivity and increases allergen‐induced airway inflammation. This is in agreement with the clinical observation that stressful life events increase the risk of a new asthma attack. Activation of the hypothalamic–pituitary–adrenal (HPA) axis by specific cytokines increases the release of cortisol, which in turn feeds back and suppresses the immune reaction. Data from animal models suggest that inability to increase glucocorticoid production in response to stress is associated with increased airway inflammation with mechanical dysfunction of the lungs. Recently, a growing body of evidence shows that asthmatic subjects who are not treated with inhaled corticosteroids (ICS) are likely to have an attenuated activity and/or responsiveness of their HPA axis. In line with this concept, most asthmatic children demonstrate improved HPA axis responsiveness on conventional doses of ICS, as their airway inflammation subsides. Few patients may experience further deterioration of adrenal function, a phenomenon which may be genetically determined.
A compensatory delay in the maturational tempo in early-maturing girls and a catch-up mechanism in late-maturing girls was shown. The maturational differences manifest as differences in the time span from the onset of puberty to PHV. Early pubertal maturation in girls does not compromise adult height and is not always followed by early menarche.
What is already known about this subject• Breakfast skipping has been positively associated with childhood obesity.• Frequent meal consumption has been inversely associated with obesity in childhood.• There is lack of evidence about the common effect of the aformentioned meal patterns in overweight or obese children.What this study adds• Consuming more than 3 meals per day was associated with a lower likelihood of overweight or obesity if-andonly-if breakfast was not skipped.• Having breakfast on a daily basis together with a full meal pattern could contribute in the prevention of childhood obesity. SummaryObjectives: Increased meal frequency and daily breakfast consumption have been inversely associated with childhood obesity. The purpose of the study was to examine the possible interaction effect between meal frequency and breakfast consumption on childhood obesity.Methods: Seven hundred children (323 boys) aged 10-12 years were enrolled in this cross-sectional study. Several lifestyle, dietary and physical activity characteristics were recorded with food frequency and physical activity questionnaires. Body height and weight were measured and body mass index was calculated in order to classify children as overweight or obese (International Obesity Task Force classification). Multiple logistic regression analysis was used in order to evaluate the interaction between daily breakfast intake and more than three meals per day consumption with overweight or obesity.Reuslts: Of the children, 27.6% and 9.0% were overweight and obese, respectively. Moreover, 60.2%consumed three or more meals per day and 62.7% consumed breakfast in a regular daily basis. Children who consumed more than three meals per day and also consumed breakfast daily, were two times less likely to be overweight or obese (adjusted odds ratio: 0.49, 95% confidence interval: 0.27-0.88). Conclusion:A combined higher meal frequency and daily breakfast consumption dietary pattern may prevent overweight and obesity in children.
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