Melatonin in cancer biology: pathways, derivatives, and the promise of targeted delivery.

Melatonin, historically recognized for its primary role in regulating circadian rhythms, has expanded its influence particularly due to its wide range of biological activities. It has firmly established itself in cancer research. To highlight its versatility, we delved into how melatonin interacts with key signaling pathways, such as the Wnt/ß-Catenin, PI3K, and NF-κB pathways, which play foundational roles in tumor development and progression. Notably, melatonin can intricately modulate these pathways, potentially affecting various cellular functions such as apoptosis, metastasis, and immunity. Additionally, a comprehensive review of current clinical studies provides a dual perspective. These studies confirm melatonin's potential in cancer management but also underscore its inherent limitations, particularly its limited bioavailability, which often relegates it to a supplementary role in treatments. Despite this limitation, there is an ongoing quest for innovative solutions and current advancements include the development of melatonin derivatives and cutting-edge delivery systems. By synthesizing the past, present, and future, this review provides a detailed overview of melatonin's evolving role in oncology, positioning it as a potential cornerstone in future cancer therapeutics.

Field implementation of long-distance quantum key distribution over aerial fiber with fast polarization feedback.

Quantum key distribution with polarized qubits has not yet been realized over the aerial fiber, due to rapid polarization changes. Here, we report our recent work towards quantum communication through an aerial fiber channel. We designed a fast polarization feedback module featuring high efficiency, fast speed, and good stability. With this module, we implemented long-distance quantum key distribution over different types of aerial fiber links based on polarization encoding. Our work takes a significant step towards the application of quantum communications in complex environments.

[Relationship between serum adiponectin and bone mineral density in preterm infants].

OBJECTIVE: To examine serum adiponectin level in preterm infants and to evaluate the relationship between serum adiponectin and bone mineral density in preterm infants. METHODS: Seventy-two appropriate-for-gestational-age neonates were classified into three groups according to their gestational ages: early preterm (31-33(+6) weeks, 13 cases), late preterm (34-36(+6) weeks, 16 cases), and full-term (37-42 weeks, 43 cases). Venous blood was collected at one week of their life to measure serum adiponectin concentration. During the period, omnisense ultrasound bone sonometer was applied to measure speed of sound (SOS) of the left tibia. RESULTS: The median of tibia SOS in the early preterm group was significantly lower than in the late preterm and full term groups (P<0.05), and the median of tibia SOS in the late preterm group was lower than in the full-term group (P<0.05). Serum adiponectin level was lowest in the early preterm group, and the full-term group had the highest serum adiponectin level. Serum adiponectin level was positively correlated with tibia SOS in preterm infants (r=0.664, P<0.05). According to the result of multivariate linear stepwise regression analysis, serum adiponectin and birth weight were independent predictor of tibia SOS in preterm infants. CONCLUSIONS: Serum adiponectin level is lower in preterm infants than that in full-term infants. There is a positive correlation between serum adiponectin and bone mineral density in preterm infants.

[Relationship between bone turnover markers and bone sound of speed in appropriate-for-gestational-age neonates].

OBJECTIVE: To investigate the correlation of gestational age (GA) with carboxyterminal propeptide of type I procollagen (PICP), deoxypyridinoline (DPD), and bone sound of speed (SOS) in appropriate-for-gestational-age (AGA) neonates, as well as the relationship between bone turnover markers and bone SOS. METHODS: Sixty-five AGA neonates were included in the study. The neonates were divided into three groups: preterm infant (GA ≤3 4 weeks, 14 cases), late preterm infant (34 weeks

Quantitative study of circadian variations of ambulatory blood pressure in Chinese healthy, hypertensive, and diabetes subjects.

Ambulatory blood pressure monitoring (ABPM) recorded abundant data of BP and heart rate (HR) variations with even more derived parameters for evaluation of BP. Using our ABP database system established recently, we studied quantitatively the data of 24-hr ABP in Chinese. First, 155 Chinese were divided into three groups: 50 healthy subjects (C) of 20 men and 30 women, aged 60.0 +/- 10.3 (SD) years; 58 hypertensive patients (H, mild or moderate hypertension) of 33 men and 25 women, aged 59.4 +/- 8.0 years; 47 diabetes patients (D, type 2 diabetes, all were normotensive and with no insulin treatment) with 28 men and 19 women, aged 61.0 +/- 8.5 years. Then 24-hr ABP was monitored by TM-2421 Monitor and data were analyzed by ABP database, cosinor method, and conventional statistics. Our results were 4-fold: 1) systolic BP (SBP), diastolic BP (DBP), HR, rate-pressure product (HR x SBP) showed circadian variations, and significant circadian rhythms were confirmed by cosinor method in all groups. MESOR (midline estimate statistic of rhythm) differed significantly among three groups (H had the highest and C had the lowest values); 2) BP means (SBP, DBP, pulse pressure [PP], and HR x SBP) and BP loads (SBP, DBP, and PP) showed significant differences among the groups (H and D had higher values than that of C); 3) there were no significant differences of BP variability (BPV) of SBP, DBP, and PP among the groups; 4) areas under curve of BP (SBP, DBP, and PP) in H were significantly higher than in C and there was no significant difference between H and D. We concluded that ABPM can offer abundant information on BP evaluation by its direct recording data and derived parameters. The computerized way of treating the large numbers of ABPM values supplies a useful tool in evaluation of BP. Our results suggest that clinically normotensive diabetes patients had some pathological alterations in their BP systems.

Overweight influence on circadian variations of ambulatory blood pressure in Chinese adolescents.

Childhood obesity and its consequences have been the subject of intense interest in recent years. In this study we examined the influence of overweight on circadian variations of ambulatory blood pressure (ABP) in Chinese adolescents. First, 24-hr ABP monitoring was performed in 252 adolescents divided into two groups with equivalent sex, age, and body height (49 girls and 77 boys in each group): controls (normal weight) were aged 13.68 +/- 1.21 years, height 165.37 +/- 9.45 cm, body mass index (BMI) 18.82 +/- 2.3; overweights (BMI > or = 24) were aged 13.71 +/- 1.23 years, height 165.75 +/- 9.47 cm, BMI 27.70 +/- 3.1. ABP recordings were treated by ABP database system and analyzed by cosinor method and conventional statistics methods. The circadian variations of ABP in adolescent patterned as "dipper" and circadian rhythmicity of ABP variations were confirmed by cosinor analysis in most adolescents of both groups. Significant statistical differences were found for rhythm parameters: the MESOR (midline estimate statistic of rhythm), peak, trough (the maximum and minimum values derived from the composed curves, respectively), and amplitude values between control and overweight groups. Significant higher values also were seen in the overweight group for most of ABP parameters (p < .01), such as, BP means (SBP, DBP, MAP: mean arterial pressure, or PP: pulse pressure), BP variability, BP loads and rate-pressure product (HR x SBP). Our results have shown that overweight influenced significantly on ABP and parameters derived from ABP recordings in Chinese adolescents, which suggests an increasing risk of cardiovascular diseases in overweight adolescents.

Cortisol secretion in the elderly. Influence of age, sex and cardiovascular disease in a Chinese population.

Adrenal function and aging have been the object of intense interest in recent years. In this study we analyzed morning (08:00 h) serum cortisol concentrations from a sample of Chinese subjects aged from 31 to 110 years. These levels differed according to age, health status and sex, although the sex difference was confirmed only among the healthy elderly. These results suggest that age (older than 60 years), disease and male sex are associated with increased morning serum cortisol levels in a Chinese population.

Circadian rhythm characteristics of serum cortisol and dehydroepiandrosterone sulfate in healthy Chinese men aged 30 to 60 years. A cross-sectional study.

The relation of adrenal function and aging has been the subject of intense interest in recent years. The circadian variations of plasma cortisol have been described in Caucasians, but little information is available on such hormone variations among the Chinese population, especially its changes with age. This study was, therefore, designed to examine the effects of age on the circadian variations of serum cortisol, dehydroepiandrosterone sulfate (DHEAS) and the molar ratio of cortisol/DHEAS in Chinese men, stratified by 10-year age-groups (i.e. men in their 30-60s, aged from 31 to 63 years old). Circadian variations of serum cortisol and DHEAS were documented at 2-h intervals from 8:00 to 22:00 and hourly from 22:00 to 8:00 in 26 healthy Chinese men. We found that the serum levels of both hormones showed a statistically significant circadian rhythmicity in all age-groups. The circadian pattern of serum cortisol was characterized by peaks (04:00-06:00) and troughs (18:00-24:00) occurring approximately 2h earlier than those usually reported in Caucasians. Aging did not significantly influence serum cortisol concentrations, but serum DHEAS levels declined significantly with age: subjects in their 60s had significantly lower levels, and their cortisol/DHEAS molar ratios were significantly higher than those in the younger age-groups.

Age-related modifications of circadian rhythm of serum leptin in healthy men.

BACKGROUND: Leptin, the product of the ob gene, is secreted by the adipocyte and is involved in the regulation of body weight, energy homeostasis and a wide spectrum of biological activities. OBJECTIVE: We studied how variations in circadian serum leptin levels change as people age. METHODS: Serum leptin levels were studied on a circadian basis in 26 men, 6 overweight (BMI >27.8) and 20 with normal weight. The normal-weight men were divided into four age groups: (A) in their 30s, (B) in their 40s, (C) in their 50s, and (D) in their 60s. Serum samples were drawn at 2-hour intervals from 8:00 to 22:00 and hourly from 22:00 to 8:00 for a total of 24 h. RESULTS: A significant circadian variation of leptin levels was found whatever the age with a peak at night and a trough around noon. The circadian leptin levels were higher in the older normal-weight groups (50s and 60s) and in the groups with a BMI >27.8. CONCLUSION: Our study demonstrates that changes in the characteristics of the circadian rhythm of serum leptin in healthy men are associated with both advancing age and increased BMI.

Aging and the circadian rhythm of melatonin: a cross-sectional study of Chinese subjects 30-110 yr of age.

Although previous reports indicate that nocturnal plasma melatonin secretion declines with age, some recent findings do not support this point. In the present cross-sectional study, we documented serum melatonin concentrations at two time points, 02:00 and 08:00 h, in 144 persons aged 30-110 yr and found a significant age-related decline. It began around the age of 60 and reached a very significantly lower level in subjects in their 70s and over 80 yr of age (P < 0.01, when compared with age <60 yr). Nocturnal melatonin levels were higher among (post-menopausal only) women than men overall (P < 0.05). In the older age-groups, nocturnal melatonin levels did not differ between healthy controls and subjects with high blood pressure or ischemic heart disease. To further check these results, we also assessed the circadian pattern of serum melatonin in four subgroups of healthy men, aged 30-39, 40-49, 50-59, and 60-69 yr: blood samples were taken at 2 h intervals from 08:00 to 22:00 h and hourly from 22:00 to 08:00 h. Our results showed generally similar circadian melatonin patterns that peaked at night with very low levels during the daytime. No significant difference was found among the three younger groups, but nocturnal melatonin levels were significantly lower in the men in their 60s.