scholarly journals Melanin-concentrating hormone in peripheral circulation in the human

2017 ◽  
Vol 232 (3) ◽  
pp. 513-523 ◽  
Author(s):  
J Naufahu ◽  
F Alzaid ◽  
M Fiuza Brito ◽  
B Doslikova ◽  
T Valencia ◽  
...  
Keyword(s):  
Energy Homeostasis ◽  
Reference Range ◽  
Resting Metabolic Rate ◽  
Peripheral Circulation ◽  
Reference Ranges ◽  
Older Individuals ◽  
Rp Hplc ◽  
Melanin Concentrating Hormone ◽  
Males And Females

Melanin-concentrating hormone (MCH) is a hypothalamic neuropeptide with a well-characterised role in energy homeostasis and emergent roles in diverse physiologic functions such as arousal, mood and reproduction. Work to date has predominantly focused on its hypothalamic functions using animal models; however, little attention has been paid to its role in circulation in humans. The aims of this study were to (a) develop a radioimmunoassay for the detection of MCH in human plasma; (b) establish reference ranges for circulating MCH and (c) characterise the pattern of expression of circulating MCH in humans. A sensitive and specific RIA was developed and cross-validated by RP-HPLC and MS. The effective range was 19.5–1248 pg MCH/mL. Blood samples from 231 subjects were taken to establish a reference range of 19.5–55.4 pg/mL for fasting MCH concentrations. There were no significant differences between male and female fasting MCH concentrations; however, there were correlations between MCH concentrations and BMI in males and females with excess fat (P < 0.001 and P = 0.020) and between MCH concentrations and fat mass in females with excess fat (P = 0.038). Plasma MCH concentrations rose significantly after feeding in a group of older individuals (n = 50, males P = 0.006, females P = 0.023). There were no robust significant correlations between fasting or post-prandial MCH and resting metabolic rate, plasma glucose, insulin or leptin concentrations although there were correlations between circulating MCH and leptin concentrations in older individuals (P = 0.029). These results indicate that the role of circulating MCH may not be reflective of its regulatory hypothalamic role.

Role of inertia in the measurement of dynamic compliance

1975 ◽  
Vol 38 (1) ◽  
pp. 64-69 ◽  
Author(s):  
J. Dosman ◽  
F. Bode ◽  
J. Urbanetti ◽  
R. Antic ◽  
R. Martin ◽  
...  
Keyword(s):  
Frequency Dependence ◽  
Dynamic Compliance ◽  
Age Group ◽  
Older Individuals ◽  
Breathing Frequency ◽  
Frequency Dependent ◽  
Younger Age ◽  
Significant Difference ◽  
Males And Females

Dynamic compliance (Cdyn) was measured at different frequencies (breaths/min) in 30 nonsmoking males and females aged 30–59 yr. In those aged 30–49 yr Cydn at 90 breaths/min was significantly higher than at 15 breaths/min while those aged 50–59 yr showed no significant difference. Assuming an inertance of 0.01 cmH2O/l per s-2, and a sinusoidal breathing frequency, Cydn at 60 and 90 breaths/min was corrected for inertia. In the 30–49 yr age group corrected Cydn did not change with increasing frequency of breathing whereas in the 50–59 yr age group Cydn at 15 breaths/min was significantly higher than at 90 breaths/min (P is less than 0.05). In this age group, four of eight subjects were frequency dependent when corrected for inertia. These findings indicate that inertia influences Cydn at breathing frequencies of 60 per min and above. Unless this is taken into account, frequency dependence of compliance may be missed. The results also indicate that frequency dependence of compliance is normal in some older individuals but is not normal in the younger age group.

MCH Neuron Activity Is Sufficient for Reward and Reinforces Feeding

2019 ◽  
Vol 110 (3-4) ◽  
pp. 258-270 ◽  
Author(s):  
Pelin Dilsiz ◽  
Iltan Aklan ◽  
Nilufer Sayar Atasoy ◽  
Yavuz Yavuz ◽  
Gizem Filiz ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Glucose Tolerance ◽  
Energy Homeostasis ◽  
Neuron Activity ◽  
Physiological Effects ◽  
Short Term ◽  
Direct Role ◽  
Reward Function ◽  
Melanin Concentrating Hormone

Background: Melanin-concentrating hormone (MCH)-expressing neurons have been implicated in regulation of energy homeostasis and reward, yet the role of their electrical activity in short-term appetite and reward modulation has not been fully understood. Objectives: We investigated short-term behavioral and physiological effects of MCH neuron activity manipulations. Methods: We used optogenetic and chemogenetic approaches in Pmch-cre transgenic mice to acutely stimulate/inhibit MCH neuronal activity while probing feeding, locomotor activity, anxiety-like behaviors, glucose homeostasis, and reward. Results: MCH neuron activity is neither required nor sufficient for short-term appetite unless stimulation is temporally paired with consumption. MCH neuronal activation does not affect short-term locomotor activity, but inhibition improves glucose tolerance and is mildly anxiolytic. Finally, using two different operant tasks, we showed that activation of MCH neurons alone is sufficient to induce reward. Conclusions: Our results confirm diverse behavioral/physiological functions of MCH neurons and suggest a direct role in reward function.

Chronic intracerebroventricular infusion of MCH causes obesity in mice

2003 ◽  
Vol 284 (3) ◽  
pp. E583-E588 ◽  
Author(s):  
Akira Gomori ◽  
Akane Ishihara ◽  
Masahiko Ito ◽  
Satoshi Mashiko ◽  
Hiroko Matsushita ◽  
...  
Keyword(s):  
Body Weight ◽  
Weight Control ◽  
Energy Homeostasis ◽  
The Body ◽  
Intracerebroventricular Infusion ◽  
Melanin Concentrating Hormone ◽  
Important Regulator ◽  
Obesity In Mice ◽  
Body Weight Control

Melanin-concentrating hormone (MCH) is a cyclic amino acid neuropeptide localized in the lateral hypothalamus. Although MCH is thought to be an important regulator of feeding behavior, the involvement of this peptide in body weight control has been unclear. To examine the role of MCH in the development of obesity, we assessed the effect of chronic intracerebroventricular infusion of MCH in C57BL/6J mice that were fed with regular or moderately high-fat (MHF) diets. Intracerebroventricular infusion of MCH (10 μg/day for 14 days) caused a slight but significant increase in body weight in mice maintained on the regular diet. In the MHF diet-fed mice, MCH more clearly increased the body weight accompanied by a sustained hyperphagia and significant increase in fat and liver weights. Plasma glucose, insulin, and leptin levels were also increased in the MCH-treated mice fed the MHF diet. These results suggest that chronic stimulation of the brain MCH system causes obesity in mice and imply that MCH may have a major role in energy homeostasis.

Indirect calorimetry measurements of behavioral thermoregulation in a semiaquatic social rodent, Myocastor coypus

1992 ◽  
Vol 70 (5) ◽  
pp. 907-911 ◽  
Author(s):  
Christine Moinard ◽  
C. Patrick Doncaster ◽  
Hervé Barré
Keyword(s):  
Metabolic Rate ◽  
Indirect Calorimetry ◽  
Cold Water ◽  
Resting Metabolic Rate ◽  
Behavioral Thermoregulation ◽  
Myocastor Coypus ◽  
Thermoneutral Zone ◽  
Different Temperatures ◽  
Males And Females

The role of behavior is quantified in the maintenance of thermic homeostasis by a semiaquatic rodent, the coypu (Myocastor coypus). Indirect calorimetry measurements showed that huddling behavior is responsible for a 20% drop in resting metabolic rate at temperatures below the thermoneutral zone. Different associations of males and females in groups of two and three resulted in significant differences in decreases of resting metabolic rate. In a cold environment (Ta = −5 °C), males used a ball-like posture significantly more often than females. When presented with a choice of substrates (air versus water) at different temperatures, females tended to reduce their time spent in cold water but males did not, despite a greater loss of energy in water compared with air. These results appear to express a conflict between social and thermoregulatory behaviors, contributing to male-biased mortality in winter.

Effects of Age and Health on the Euthyroid Reference Ranges for Serum Free Thyroxine and Free Triiodothyronine

1985 ◽  
Vol 24 (02) ◽  
pp. 57-65 ◽  
Author(s):  
J. E. M. Midgley ◽  
K. R. Gruner
Keyword(s):  
Lower Limit ◽  
Healthy Subjects ◽  
Thyroid Dysfunction ◽  
Reference Range ◽  
Free Thyroxine ◽  
Reference Ranges ◽  
Free Triiodothyronine ◽  
Serum Free ◽  
Young Subjects ◽  
Age Range

SummaryAge-related trends in serum free thyroxine (FT4) and free triiodothyronine (FT3) concentrations were measured in 7248 euthyroid subjects (age-range 3 months to 106 years). 5700 were patients referred to hospitals for investigation of suspected thyroid dysfunction, but who were diagnosed euthyroid. 1548 were healthy blood donors (age-range 18-63 years) with no indication of thyroid dysfunction. FT4 concentrations were little affected by the age, the sex or the state of health of the subjects in either group. Serum FT3 concentrations were significantly affected by both age and health factors. The upper limit of the euthyroid reference range for young subjects up to 15 years was about 20% higher (10.4 pmol/1) than for adult subjects older than 25 years (8.8 pmol/1). The change in the upper limits typical of young subjects to that typical of adults occurred steadily over the decade 15–25 years. After this age, little further change occurred, especially in healthy subjects. Additionally, the lower limit of the euthyroid range for FT3 was extended by the inclusion in the reference group of patients referred to hospitals. Compared with the lower limit of the FT3 range for healthy subjects (5 pmol/1), the corresponding limit for referred subjects (young or adult) was 3.5–3.8 pmol/1. Broadening of the FT3 reference range was probably brought about by a significant number of patients in the hospital-referred group with the “1OW-T3 syndrome” of mild non-thyroidal illness. Accordingly, FT3 was inferior to FT4 in the discrimination of hypothyroidism, as FT4 was unaffected by this phenomenon. Effects of age and non-thyroidal illness on serum FT3 concentrations require great care when selecting subjects for a laboratory euthyroid reference range typical of the routine workload. Constraints on the choice of subjects for FT4 reference ranges are less stringent.

Gender Diversity in Computing: An Environmental Perspective

10.28945/3248 ◽  
2008 ◽  
Author(s):  
Cecille Marsh
Keyword(s):  
Gender Diversity ◽  
Household Head ◽  
Female Students ◽  
Political Factors ◽  
Female Household Head ◽  
Dominant Female ◽  
Computer Confidence ◽  
Males And Females ◽  
Research Questions

Previous research conducted by the author investigated the socio-political backgrounds of two groups of female students studying computer-related university programmes. They came from distinctly different backgrounds and were enrolled at two institutions with very different legacies. The author found that socio-political factors, in particular the role of a dominant female household head and aggressive governmental affirmative action, had a significant effect on the girls’ levels of confidence and subsequently on their decision to study computer-related courses. Based on this insight, the researcher undertook to look further into gender diversity with respect to self-perceived general computer confidence and self-perceived ability to program a computer. A sample of both female and male Information T echnology students from very similar disadvantaged socio-economic backgrounds was surveyed. The sample of 204 students was drawn from all three years of the National Diploma in Information Technology. The author considered the following research questions: (i) Do males and females studying computer-related courses have differing computer selfefficacy levels? (ii) Do males and females studying computer programming have differing attitudes towards their ability to program? (iii) Do males and females differ in their attitudes towards the programming learning environment?

Age Advantages of Emotional Experience during the COVID-19 Pandemic are Robust, but Diminished Compared to Pre-pandemic Conditions

2020 ◽  
Author(s):  
Rui Sun ◽  
Disa Sauter
Keyword(s):  
Older Adults ◽  
Large Scale ◽  
Negative Emotion ◽  
Emotional Experience ◽  
Negative Emotions ◽  
Older Individuals ◽  
Selection Strategies ◽  
Scale Test ◽  
Prolonged Stress

Getting old is generally seen as unappealing, yet aging confers considerable advantages in several psychological domains (North &amp; Fiske, 2015). In particular, older adults are better off emotionally than younger adults, with aging associated with the so-called “age advantages,” that is, more positive and less negative emotional experiences (Carstensen et al., 2011). Although the age advantages are well established, it is less clear whether they occur under conditions of prolonged stress. In a recent study, Carstensen et al (2020) demonstrated that the age advantages persist during the COVID-19 pandemic, suggesting that older adults are able to utilise cognitive and behavioural strategies to ameliorate even sustained stress. Here, we build on Carstensen and colleagues’ work with two studies. In Study 1, we provide a large-scale test of the robustness of Carstensen and colleagues’ finding that older individuals experience more positive and less negative emotions during the COVID-19 pandemic. We measured positive and negative emotions along with age information in 23,629 participants in 63 countries in April-May 2020. In Study 2, we provide a comparison of the age advantages using representative samples collected before and during the COVID-19 pandemic. We demonstrate that older people experience less negative emotion than younger people during the prolonged stress of the COVID-19 pandemic. However, the advantage of older adults was diminished during the pandemic, pointing to a likely role of older adults use of situation selection strategies (Charles, 2010).

Role of Nut Consumption in the Management of Cognitive Decline - A Mini-Review

2018 ◽  
Vol 15 (9) ◽  
pp. 877-882 ◽  
Author(s):  
Blanka Klimova ◽  
Kamil Kuca ◽  
Martin Valis ◽  
Jakub Hort
Keyword(s):  
Cognitive Decline ◽  
Cognitive Functions ◽  
Dietary Intervention ◽  
Social Issues ◽  
Older Individuals ◽  
Active Life ◽  
Healthy Nutrition ◽  
Health Aging ◽  
Review Study

Background: Currently, there is a significant increase in the number of older generation groups, which may result in serious economic and social issues. Therefore, there is a need to prolong the active life of these older individuals, especially by focusing on modifying lifestyle factors such as healthy nutrition. In fact, recent research has shown that, for example, nuts are an important part of people’s healthy diet because they have appeared to be neuroprotective compounds which might maintain or in some cases even improve people’s cognitive functions. Objective: The purpose of this review study is to explore the role of the nut nutrition in the maintenance and delay of cognitive decline among older individuals. Results: The findings indicate that the nut consumption may contribute to the delay of cognitive decline in aging. However, this nut diet is just one component of the multi-nutrient dietary intervention for health aging. Conclusion: More longitudinal controlled randomized studies have to be performed in this field to prove the efficacy of the nut nutrition for the delay of cognitive decline.

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