Social and environmental determinants of reproductive cycles in patas monkeys

The menstrual cycles of a captive group of patas monkeys were followed for 15 months by taking vaginal smears and lavages three times a week. Without an adult male in the group, menstrual cycles still showed the expected qualitative changes previously associated with the onset and with the end of a mating period. The addition of an adult male to the female group, once mating season cycles were evident, did not result in further changes in erythrocytes or sediment levels in vaginal samples or cycle regularity. Menstrual-cycle onsets for related females were significantly more synchronized than onsets for unrelated females. Preliminary observations on adult male patas housed separately from the females indicate that they too undergo seasonal changes in physiology and behavior.     

Reproduction in the vervet monkey (Cercopithecus aethiops): II. Annual menstrual patterns and seasonality

Menstrual patterns and progesterone levels were monitored for 5 years from a cohort of 28 female vervet monkeys that were individually caged indoors. Three distinct cycle types (short, normal, and prolonged) were defined according to cycle length. Mean length of the normal cycle (32.5 days) and menses duration (4.8 days) are in agreement with previous reports. Prolonged cycles (> 50 days) contributed 20% of the total, with a decreased incidence during the natural peak breeding period. Weekly progesterone measurements indicated that many prolonged cycles were associated with an extended luteal phase, while others were probably due to lack of ovulation. From these data it would appear that the vervet monkey, although not strongly seasonal, does favor a particular time of year for breeding in a colony housed indoors.     

Timing of surgery during the menstrual cycle and prognosis of breast cancer

There are conflicting reports on the differential effect of surgery performed during the two phases of the menstrual cycle, namely, follicular and luteal, and prognosis of operable breast cancer. A statistical meta-analysis of the published evidence suggests a modest survival benefit of 15+/-4% when the operation is performed during the luteal phase. Further research in this area might provide a novel avenue to understand the natural history of breast cancer. A spin off from these studies might be the understanding of the importance of events that occur at the time of surgery in determining long term prognosis.     

Cellular characteristics of nipple aspiration fluid during the menstrual cycle in healthy premenopausal women

Cellular characteristics of nipple aspiration fluid during the menstrual cycle in healthy premenopausal women Fifteen healthy premenopausal female volunteers underwent weekly nipple aspiration of ductal fluid from both breasts during two menstrual cycles to investigate the variability of the cellular profile of the ductal fluid. Ductal fluid was successfully obtained using breast massage and nipple-areolar suction from 247/280 (89%) breasts. 83% of samples available for cytological analysis were cellular and 30% of cellular aspirates contained ductal epithelial cells identified using standard morphological criteria. No significant variation in cell number or cell type was identified during the menstrual cycle. All samples tested had an 'H' score of zero for oestrogen receptor. Seven out of 14 women expressed the proliferation marker Mcm-2 in the cells of at least one of the specimens, with no evidence of a menstrual cycle influence on expression. In conclusion, the cellular profile of breast ductal fluid did not vary consistently during the menstrual cycle, permitting future breast cancer screening studies incorporating serial nipple aspirations to be performed independent of the phase of the cycle.     

Analytical and biological variation of biomarkers of oxidative stress during the menstrual cycle

Little information is available on the intra-individual variability of oxidative stress biomarkers in healthy individuals and even less in the context of the menstrual cycle. The objective of this study was to characterize the analytical and biological variability of a panel of 21 markers of oxidative damage, antioxidant defence and micronutrients in nine healthy, regularly menstruating women aged 18–44 years. Analyses included measurement of lipid peroxidation, antioxidant enzymes and antioxidant vitamins. Blood specimens were collected, processed and stored using standardized procedures on days 2, 7, 12, 13, 14, 18, 22 and 28 in one cycle for each subject. Replicate analyses of markers were performed and two-way nested random effects ANOVA was used to describe analytical, intra-individual and inter-individual variability. No statistically significant differences at α=0.05, or temporal effects across the menstrual cycle were observed. Analytical variability was the smallest component of variance for all variables. The ICC among replicates ranged from 0.80 to 0.98. Imprecision based on quality control materials ranged from 1 to 11%. The critical differences between serial results varied greatly between assays ranging from 6 to 216% of the mean level. These results provide important initial information on the variability of biomarkers of oxidative stress, antioxidant defence and micronutrients across the menstrual cycle.     

Urinary immunoreactive estrogen and pregnanediol-3-glucuronide during the normal menstrual cycle of the female lowland gorilla (Gorilla gorilla)

Urine samples were taken daily during 22 menstrual cycles of six normal adult female gorillas. Urine was analyzed for total immunoreactive estrogens (E_t) and pregnanediol-3-glucuronide (PdG) and indexed by creatinine (Cr). An average cycle length of 32 ± 1 days (mean ± SE) with a range of 25–42 days is reported. Estrogen values range from 4 to 128 ng/mg Cr and show a midcycle peak and a midluteal rise. PdG values range from 0.01 to 2.4 μg/mg Cr and display a low, flat follicular phase followed by a luteal elevation. The follicular phase is 19.5 ± 1 days in length (range 11–30 days) and accounts for the variation in cycle length. The luteal phase is 12.3 ± 0.3 days long (range 10–14 days). In contrast to previous studies, PdG levels rise two days before the estrogen peak. The results from the present study are compared with information available on the gorilla, chimpanzee, and human. The accuracy of various alignment methods is discussed, as well as the importance of the methods presented in this study for the captive propagation of gorillas.     

Genetic and environmental determinants of osteoporosis

Osteoporosis is a common, complex disease that is influenced by genetic and environmental factors. Although molecular genetic studies have identified several potential regions of linkage, underlying susceptibility gene(s) are largely unknown. Genetic susceptibility to osteoporosis may be both context dependent and developmentally regulated, and epigenetic mechanisms are the likely link between gene and environment. In this paper we will review the status of genetic research into osteoporosis, and present the evidence for gene-environment interaction in its pathogenesis. Finally, the current challenges and future directions of research will be briefly discussed.     

Plasma levels of gonadotropin releasing hormone during menstrual cycle ofMacaca radiata

A sensitive radioimmunoassay for gonadotropin releasing hormone has been developed. The assay has been validated for its specificity by testing various analogues of gonadotropin releasing hormone. Analysis of plasma samples during the menstrual cycle of 4 female bonnet monkeys showed a significant increase in the immunoreactive gonadotropin releasing hormone levels during preovulatory period of the menstrual cycle.     

月经周期对女性睡眠-觉醒和静息-活动的影响

目前有关月经周期对睡眠影响的研究结果并不一致,而对月经周期中昼夜睡眠-觉醒及静息-活动节律尚缺乏系统性的研究.本研究旨在观察正常育龄期女性月经周期中睡眠-觉醒及静息-活动昼夜节律的变化.我们采用静息-活动监测仪(actigraphy)和睡眠日志,调查了12个自然生活状态下健康育龄期妇女在月经周期不同阶段,即行经期、围排卵期、黄体早期及黄体晚期中睡眠与活动节律的变化.结果显示,睡眠-觉醒节律参数在四期之间无统计学显著差异;而静息-活动节律方面,所有受试女性静息-活动节律的平均日周期长度为(24.01±0.29)h,并且四期之间无显著性差异.行经期日间稳定系数(interdaily stability,IS)比黄体早期显著增加(P＜0.05).黄体早期日间活动开始时间明显较黄体晚期提前(P＜0.05);黄体早期的活动峰值时相比围排卵期显著提前(P＜0.05).月经周期可以影响静息-活动昼夜节律时相.而总体静息-活动数量与质量未发生显著变化;健康育龄期妇女在月经周期的各阶段中睡眠-觉醒节律亦无明显变异.     

Genetic and environmental determinants of skin color

Skin reflectance measurements on a sample of 154 Black and 191 White same-sex twin pairs, attending Philadelphia area schools, are analyzed to determine the effects of genetic and environmental factors. The measurements obtained in July and August, on the forehead, inner upper arm, and flexor surface of the forearm with red, green, and blue filters, were reduced to one index which we call skin color. Analysis of this index using the path analysis of Rao et al. ('74) estimates the major variance components due to racial, residual genetic, and common environmental factors as 67%, 5%, and 22%, respectively.     

Determinants of behavioral rhythmicity during artificial menstrual cycles in rhesus monkeys (Macaca mulatta)

Reproductive success in many mammals depends on synchrony between copulation and ovulation, which is insured by the phenomenon of heat in the female. Certain anthropoid primates including rhesus monkeys do not show heat but may copulate throughout the menstrual cycle, especially when pairs are isolated from conspecifics. In social groups, however, mating mostly occurs around midcycle. We wished to test the hypothesis that copulations are more closely linked to ovulation when males have simultaneous access to several females in different cycle phases. Artificial menstrual cycles were therefore induced by giving hormones to ovariectomized female rhesus monkeys observed in small social groups that each consisted of four females and one male. The cycles of two hormone-treated femlab in each group were either made to synchronize or be offset by 7-day increments so that the estradiol peak of one female occurred 7 days before, and 7 and 14 days after, the estradiol peak of the other. Radioimmunoassay of plasma samples (N = 224) confirmed the timing of the estradiol peaks. Results from eight unique male-female groups (4 males, 8 females, 16 male-female pairs, 718 tests) fully supported the hypothesis. Compared with synchronized cycles, the amplitudes of rhythmic changes in offset cycles were reduced for ejaculations made by males but greatly enhanced for ejaculations received by females. We propose that this socio-hormonal integration of behavior in the group is highly adaptive and enhances the reproductive success of both males and females.     

Social and menstrual cycle phase influences on the behavior of group-housed Cebus apella

This study examined sexual and other social behavior in relation to menstrual cycle phase in four mixed-sex social groups of Cebus apella. Groups consisted of two adult males and either six or nine adult females. Menstrual cycles of high (rank 1–2) and low (rank 3–7) dominance-rank females from each group were monitored via vaginal swabs, and correlated with data collected from ongoing behavioral observations. Only cycles bounded by positive detection of menstrual blood were included in this analysis (n = 15 females, 182 cycles; mean ± s.d., cycle length = 20.8 ± 1.2 days). Rates of copulation and female solicitation of males varied significantly with cycle phase, with highest rates at midcycle. While total rates of solicitation and copulation did not vary with female dominance rank, copulation rates with the dominant male were significantly greater for high ranking females than for low ranking ones. Variance observed in affiliative and agonistic behaviors, including those with males, was attributable to female rank rather than cycle phase. Females and males were also observed attempting to interfere with copulations of lower ranking same-sex individuals. Although further study, particularly of wild populations, is needed, these results indicate that female-female reproductive competition should be included as a component of the capuchin breeding system. As in other primate species, both social and hormone-related factors influence the sexual behavior of Cebus apella. © 1995 Wiley-Liss, Inc.     

Fas, FasL, Bcl-2, and Bax in the endometrium of rhesus monkey during the menstrual cycle

To study possible role and regulation of apoptosis occurred in primate endometrium, the expression of apoptosis-related molecules, Fas, FasL, B cell lymphoma/leukaemia-2 (Bcl-2), and Bax were analyzed in relation to occurrence of apoptosis and proliferation in the cycling endometrium of the rhesus monkey using immunohistochemistry and Western blot. The cell apoptosis and proliferation were evaluated by means of in situ 3'-end labeling and Ki67 immunostaining, respectively. The results showed that the expressions of Fas, Fas ligand (FasL), Bcl-2, and Bax were co-localized predominantly in the epithelial cells of the endometrium. Modest Fas staining with no obvious change was detected throughout the menstrual cycle, while the levels of FasL and Bax protein in the epithelial cells increased in the secretory phase when apoptosis was most prevalent. In contrast, epithelial immunostaining for Bcl-2 was maximal during the proliferative phase and decreased in the secretory phase. Bcl-2 immunoreactivity was also detected in some immunocytes. The coordinated expression of Fas, FasL, Bcl-2, and Bax in the cycling endometrium of the rhesus monkey suggests that the cyclic changes in endometrial growth and regression may be regulated by the balance of these factors under the action of ovary steroids.     

Neuroendocrine regulation of prolactin secretion in adult female rhesus monkeys during different phases of the menstrual cycle: role of neuroexcitatory amino acid (NMA)

The present study attempts to examine the role of N-methyl-D, L-aspartate (NMDA) receptors in the central regulation of prolactin (PRL) secretion, which may be involved in ovarian function and its alteration by glutamate in various phases of the menstrual cycle of female rhesus monkeys (Macaca mulatta). The results suggest that the glutaminergic component of the control system, which governs PRL secretion by utilizing NMDA receptors, may have an important role in regulating changes in PRL secretion. The response of PRL during the luteal phase of the cycle was different from that observed in follicular and menstrual phases. Steroids may influence the NMDA-dependent drive to release PRL. N-methyl-D-aspartic acid (NMA) involvement in the regulation of PRL secretion may occur through activation of the PRL-stimulating system depending on the physiological state or steroidal milieu. It is possible, therefore, that the NMA-induced release of PRL-releasing factors (PRF) and PRL are enhanced in the presence of ovarian feedback.     

月经周期不同阶段游离皮质醇昼夜节律的变化

为了研究皮质醇分泌的昼夜节律在月经周期中的变化,实验对15位月经周期正常的育龄期健康妇女,在月经周期的不同阶段分别于24h内每隔两小时采样,检测唾液昼夜游离皮质醇水平。采用非线性回归分析模型分析皮质醇昼夜节律。结果显示,皮质醇昼夜节律在整个月经周期都具有复杂的明显受到亚节律(ultradian)影响的分泌形式;与月经期相比,围排卵期和黄体晚期昼夜节律波峰宽度(peak-width)明显减低(P=0．005与0．031),而昼夜节律波谷(trough)有抬高趋势(P=0．0622与0．066);黄体晚期的亚节律波幅(ultradian amplitude)与月经期相比显著减低(P=0．002)而与围排卵期相比有减低趋势(P=0．05)。这些结果提示月经周期的不同阶段对皮质醇分泌的昼夜节律有影响。     

Luteinizing hormone receptors in ovaries of the cynomolgus monkey (Macaca fascicularis) during the menstrual cycle

Ovarian luteinizing hormone (LH) receptors were characterized using ovarian tissues from 17 cynomolgus monkeys at different phases of the menstrual cycle. Low binding affinity receptors for ¹²⁵I-LH were observed throughout the menstrual cycle. The binding affinity of these receptors for LH (< 12 × 10¹⁰ M^?1) was approximately the same as that of ovarian LH receptors previously reported in human and nonhuman primates. In addition, high-affinity receptors (17?85 × 10¹⁰ M^?1) were also detected at the mid-luteal phase, during which a large functional corpus luteum was present. Thus the high-affinity LH receptors appear with the formation of the corpus luteum and disappear with its regression. Almost no fluctuation of binding capacity was observed throughout the menstrual cycle (32?112 fmol/ mg of ovarian tissue). The high-affinity LH receptor was judged to be derived from the functional corpus luteum.     

Genetic and environmental influences on nutrient intake

The relationship between genetic and the environment represents a pathway to better understand individual variations in nutrition intake and food preferences. However, the present literature is weakened somewhat by methodological flaws (e.g., overreliance on self-report questionnaires), discrepancies in statistical approaches, and inconsistent findings. Little research on this topic to date has included examination of micronutrient intake. The purpose of this study is to improve the existing literature on genetic and environmental influences on energy and nutrient intake by addressing these gaps. Twin pairs (N = 358; age 11–13 years) provided 3-day food intake diaries, which were assessed for intake of total energy, macronutrients, and micronutrients. Structural equation modeling revealed that genetic influences accounted for a significant portion of the total variance in total energy (48 %), macronutrients (35–45 %), minerals (45 %), and vitamins (21 %). Consistent with previous studies, the shared environment appeared to contribute little to nutritional intake. Findings on vitamin and mineral intake are novel and are particularly beneficial for further research on the contribution of micronutrients to individual physical health status. Better understanding of the linkage between genes, environment, and nutritional intake and deficiencies can clarify behavioral and physical outcomes, potentially informing risk reduction, primary prevention, and intervention strategies.