bluuebunny/crossref_metadata_2025_split huggingface dataset:
Excessive ovarian follicular development in pregnant pigtailed macaques (Macaca nemestrina)
Authors: Chandrashekar Varadaraj , Dierschke Donald J. , Wolf Richard C. 
Published: June 2005

AbstractTo evaluate the status and possible control of ovarian follicular development during pregnancy, circulating levels of estrone (E1), estradiol‐17β (E2), and follicle‐stimulating hormone (FSH) were measured throughout gestation in both intact and ovariectomized pregnant pigtailed monkeys (Macaca nemestrina). From an additional group of pregnant monkeys, ovaries were obtained at late gestation (on day 150 or 159 of pregnancy) for histological studies. Circulating concentrations of E1 and E2 increased on day 13 and remained elevated for about 10 days; they then declined and reached low levels on day 32 of gestation. After day 60, there were gradual but smaller increases in estrogen levels to day 140, after which both E1 and E2 levels increased significantly, reaching maximum levels (E1 = 832.2 ± 210.8 pg/ ml; E2 = 1.66 ± 0.32 ng/ml) at the end of pregnancy. Removal of ovaries on day 35 of gestation did not affect pregnancy or the pattern of estrogen secretion. Serum concentrations of FSH demonstrated only minor fluctuations during pregnancy but were similar to those found during the early follicular phase of cycling pigtailed monkeys investigated in this study. Ovarian histology revealed extensive follicular growth; in addition to the corpus luteum of pregnancy, ovaries were packed with pre‐antral, small antral, and medium‐sized Graafian follicles. Some of these follicles appeared to be cystic and showed various degree of atresia; their general appearance was similar to the follicles of human females with polycystic ovary syndrome. Our data suggest that FSH may initiate ovarian follicular growth during gestation. High levels of estrogens were incapable of suppressing FSH secretion but may be responsible for the induction of atresia in a large number of follicles in pregnant pigtailed monkeys.
Relation between the dominance rank of female rhesus monkeys and their access to males
Authors: Zumpe Doris , Michael Richard P. 
Published: June 2005

AbstractSystematic observations were made on 12 measures of the sexual, aggressive, and social interactions of 24 male–female pairs of rhesus monkeys in six social groups, each consisting of one male and four ovariectomized females tested in a large room. Each female in a group was treated in turn first with estradiol alone and then with estradiol and progesterone in combination. When hormone‐treated, the female was also observed during pair tests with the male in the same large observation room (four males, eight females, 240 group tests, 240 pair tests). The dominance ranks of females during group tests were determined post hoc by means of the dominance index [Zumpe & Michael, American Journal of Primatology 10:291–300, 1986]. In all six groups, the most dominant female virtually monopolized the male, and the subordinate females' interactions with the male, assessed during pair tests, were almost completely suppressed during group tests. This “dominant female effect” was a robust phenomenon that depended solely on female dominance rank. It was independent of the identity and hormonal status of females and of the social preferences of males as expressed in pair tests. These findings demonstrate the existence of female mate competition in an Old World primate.
Sexual dimorphism, mating system, and effect of phylogeny in De Brazza's monkey (Cercopithecus neglectus)
Authors: Leutenegger Walter , Lubach Gabriele 
Published: June 2005

AbstractDe Brazza's monkey (Cercopithecus neglectus), like other guenons, shows marked sexual dimorphism in an array of features. While strong sexual dimorphism is generally associated with a polygynous mating system, populations of De Brazza's monkeys in Gabon are reportedly monogamous. An explanation of this unique phenomenon is offered here. Patterns of sexual dimorphism are examined for morphology, growth and development, behavior, and ecology, and field and captive studies on the social organization and mating system of De Brazza's monkey and congeneric guenon species are reviewed. Based on the findings, it is postulated that 1) De Brazza's monkeys are not strictly monogamous, but exhibit interpopulational variation in their mating system, from facultative monogamy to mild polygyny; 2) marked sexual dimorphism most likely reflects the effect of the historical‐phylogenetic factor; ie, it represents a holdover of a degree of dimorphism established earlier in evolutionary history when the degree of polygyny Was higher; and 3) lessening in the degree of polygyny and a tendency toward monogamy represents a consequence of selection toward small group size. Small group size, a unique antipredator strategy, and failure to form polyspecific associations are ultimately most likely the result of intragroup and interspecific competition and predation pressure.
Temporal and endocrine sequelae of aspirating follicular contents in rhesus monkeys
Authors: Hutz Reinhold J. , Dierschke Donald J. , Wolf Richard C. 
Published: June 2005

AbstractAspiration of ovarian follicular contents in humans is a well‐established procedure used to obtain oocytes for fertilization in vitro (IVF). However, the effects of aspiration on the menstrual cycle and resulting luteal function have been incompletely characterized. The present study was designed to investigate alterations in the temporal and endocrine characteristics of menstrual cycles following aspiration of contents of the dominant preovulatory follicle (DF) on day 10 of the cycle in normal rhesus monkeys. When aspiration was performed prior to the preovulatory surge of luteinizing hormone (LH), cycle length was extended to 38.6 ± 8.6 [15] (x days ± SD, [n]), as compared to 29.5 ± 5.7 [8] days when the surge occurred before the time of aspiration. Mean and maximal amounts of progesterone (P) in the luteal phase and the number of days in which P‐values were > 1 ng/ml were significantly greater when aspiration was performed prior to the surge of LH than for aspiration after this event. Laparoscopic observations made in the midluteal phase in animals of the former group demonstrated that the corpus luteum (CL was derived from a follicle other than the original DF which had been aspirated on day 10 of the menstrual cycle; observations in the latter group of animals indicated that the CL was derived from the DF.
Effects of anesthetic agents on the adrenocortical system of female baboons
Authors: Walker Margaret L. , Pepe Gerald J. , Garnett Nelson L. , Albrecht Eugene D. 
Published: June 2005

AbstractInvasive surgical procedures are often used to study the reproductive and adrenocortical endocrine systems in primates. Anesthetic agents must, therefore, be used that have the least confounding effects on these systems. The present study was designed to characterize various adrenocortical endocrine responses of female baboons (Papio anubis), each treated for 120 minutes with an infusion of ketamine HCl (6 mg/min) in 5% dextrose in water (0.40 ml/min), a combination of ketamine and acetylpromazine (0.6 mg acetylpromazine and 6 mg ketamine HCl/min) in 5% dextrose in water, or inhalation of vaporized halothane (1.0% halothane, N2O 25%, 1 liter/min; O2 75%, 3 liters/min). Blood samples were collected throughout the treatment period, and serum was assayed for prolactin (PRL), dehydroepiandrosterone (DHA), dehydroepiandrosterone sulfate (DHAS), and cortisol (F). No significant elevations in DHA, F, or PRL concentrations were found following infusion of ketamine alone. Only serum DHAS concentrations were significantly altered after long‐term exposure to ketamine. Acetylpromazine increased PRL concentrations tenfold to levels significantly greater than those in ketamine‐ and halothane‐treated animals but had no effect on serum DHA, DHAS, or F. Treatment with halothane had no effect on serum PRL, DHA, or DHAS but did suppress F (>40%) concentrations over time. These data indicate that ketamine is best suited for the collection of biological samples when deep analgesia is not required but that halothane is preferable in the latter situation.
Activity budgets of woolly spider monkeys, or muriquis (Brachyteles arachnoides)
Authors: Strier Karen B. 
Published: June 2005

AbstractOne group of woolly spider monkeys, or muriquis (Brachyteles arachnoides), was observed from June 1983 through July 1984 at Fazenda Montes Claros, Minas Gerais, Brazil. The study subjects spent an average of 49% of their daylight time resting, 29% traveling, and 19% feeding. They shifted their diurnal schedule of activities in response to seasonal changes in temperature and rainfall. The activity budgets of adult males and females were similar. However, a comparison of three adult females in different reproductive conditions revealed that the lactating female spent a greater proportion of time feeding than did both the pregnant and nonreproductive females. Intraspecific differences in group size and diet appear to be important to understanding differences in the activity budgets of Brachyteles. Differences between locomotion patterns of woolly spider monkeys and sympatric howler monkeys may explain activity budget differences based on group size and diet.
Immunoreactive parathyroid hormone levels in platyrrhini and catarrhini: A comparative analysis with three different assays
Authors: Adams John S. , Gacad Mercedes A. , Rude Robert K. , Deseran Mark , Endres David B. , Mallette Lawrence E. 
Published: June 2005

AbstractSerum concentrations of the hormonal form of vitamin D3—1,25‐dihydroxy‐vitamin D3 [1,25‐(OH)2‐D3]—are elevated in many genera of platyrrhines when compared to catarrhines; this elevation is presumed to result from a decrease in the ability of the target cell receptor effectively to recognize 1,25‐(OH)2‐D3. The activity of the renal 25‐hydroxyvitumin D3‐1α‐hydroxylase, the mammalian enzyme which synthesizes the majority of the circulating 1,25‐(OH)2‐D3, is accelerated by parathyroid hormone (PTH). In order to determine whether the elevated serum concentrations of 1,25‐(OH)2‐D3 in platyrrhines were the result of relative hyperparathyroidism, we measured serum levels of immunoreactive parathyroid hormone (iPTH) in normocalcemic platyrrhines, catarrhines, and human subjects with assays that recognize different domains of the human PTH molecule. Antisera directed against the biologically active, aminoterminus of PTH yielded comparable mean values for iPTH among three test groups. The mean concentration of iPTH as assessed by a “proximal” midregion assay was significantly reduced in platyrrhine serum when compared to either human or catarrhine serum. A “distal” midregion assay yielded a reduced mean value for iPTH in both platyrrhine and catarrhine serum when compared to human serum. These data suggest that 1) high circulating levels of 1,25‐(OH)2‐D3 in New World primates are not the result of hyperparathyroidism; and 2) structural homology between human and primate PTH diminishes progressively as one moves toward the carboxyterminus of the molecule and is lost more rapidly in the platyrrhine than in the catarrhine hormone.
Movement and reproductive behavior of solitary male redtail guenons (Cercopithecus ascanius)
Authors: Jones W. Thomas , Bush Betsy B. 
Published: June 2005

AbstractAdult male redtail guenons (Cercopithecus ascanius) live as resident males in heterosexual groups or as nonresident males outside groups. Data are reported here on movement and temporary intrusions by nonresident males in heterosexual groups. These data further elucidate the reproductive strategies of this class of individual. Observations of three radiocollared males provided data on the details of their movement relative to groups. Regular sampling of three heterosexual groups provided data on patterns of nonresident males' intrusions. During peak mating months, nonresident males formed loose affiliations with groups. The males affiliated with one group at a time, with each affiliation lasting several weeks. Nonresident male intrusions in groups were unevenly distributed and were not correlated with the number of potentially fertile females in each group. Estimates of male density indicate that there were about two nonresident males per group, which suggests an adult sex ratio of three females per male within the study area. Nonresident male redtail guenons apparently do not spread their reproductive efforts over several groups at once, but instead each male tends to direct his attention toward the group offering the best opportunity for reproductive payoffs. Factors that determine which groups they attempt to infiltrate may include the characteristics of resident males, female choice, or both, but the number of fertile females probably has no effect. The male low density and female‐biased sex ratio among adults should facilitate resident males' attempts to monopolize fertilizations in groups; however, resident males were unable to prevent copulations by nonresident males even when only one nonresident was intruding in a group.
Combining scientific experimentation with conventional housing: A pilot study with rhesus monkeys
Authors: Preilowski Bruno , Reger Michael , Engele Hans 
Published: June 2005

AbstractIn search of a method to increase the validity of experimental data and simultaneously counteract the negative consequences of restricted laboratory environments, a pilot study was run with three rhesus monkeys (Macaca mulatta), which were trained and tested with a laboratory‐type task in the animal housing facility. The testing apparatus was made available to individual animals 24 hours a day at their living cage and was connected to a computer that controlled the test and the distribution of regular monkey chow as reward. The animals were thus able to work whenever they wanted, for whatever period of time they chose, in their accustomed home environment. Besides furnishing data on the distribution of activity and performance over extended periods of time, the study provided more data than those obtained previously when animals were tested each day for only a limited time in an isolated test chamber. It was also found that the self‐initiated manipulatory activity required by the test considerably reduced the number of motor stereotypies. Thus, testing animals within the housing facility was profitable for the investigators and beneficial for the animals.
Seasonal changes in serum dehydroepiandrosterone, androstenedione, and testosterone levels in the squirrel monkey (Saimiri boliviensis boliviensis)
Authors: Wiebe R. Herbert , Williams Lawrence E. , Abee Christian R. , Yeoman Richard R. , Diamond Edward J. 
Published: June 2005

AbstractThe squirrel monkey (Saimiri boliviensis boliviensis) has a well‐defined breeding season during which adult males undergo androgen‐dependent morphological changes, with acquisition of active spermatogenesis. To assess the hormonal events of this annual cycle, blood samples were obtained weekly from ten adult males, and serum was assayed for testosterone (T), androstenedione (ΔA), and dehydroepiandrosterone (DHEA). A significant seasonal variation was noted in mean serum T (P < 0.02), ΔA (P < 0.02), and DHEA (P < 0.001) concentrations. Mean ΔA concentrations increased from a nonbreeding season nadir of 91.4 ± 12.9 ng/ml (mean ± standard error) to a prebreeding concentration of 139 ± 10.5 ng/ml and breeding season peak of 167.5 ± 15.4 ng/ml (P < 0.05). Mean DHEA concentrations increased from a nonbreeding season nadir of 8.3 ± 0.8 to a breeding season peak of 14.3 ± 1.2 (P < 0.001). Mean T levels in the nonbreeding (52.2 ± 11.6 ng/ ml) and prebreeding season (48.6 ± 7.4) were similar. However, T significantly increased during the breeding season to 103.5 ± 12.8 ng/ml (P < 0.05). Progressive changes in body weight and morphology paralleled the rise in serum ΔA levels. The pattern of peripheral serum androgen concentrations throughout the year would suggest annual activation of the hypothalamic‐pituitary‐adrenal and/or hypothalamic‐pituitary‐gonadal axes.
Tropical rain forest conversion and perspectives in the conservation of wild primates (Alouatta and Ateles) in Mexico
Authors: Estrada Alejandro , Coates‐Estrada Rosamond 
Published: June 2005

AbstractThe original distribution of the tropical rain forest and of the populations of Alouatta palliata, Al. pigra, and the two subspecies of Ateles geoffroyi in southern Mexico have been reduced by at least 90% in the last 40 years as a result of conversion of natural habitat to pasture and agricultural fields. This dramatic conversion has been caused mainly by the rapid growth of the human population in the southern states of the country. In the region of Los Tuxtlas in southern Veracruz, where the only longitudinal popululational and ecological studies of A. palliata and At. g. vellerosus have taken place, only 15% of the original extension of the tropical rain forest remains today. The intensive destruction of suitable primate habitat in this region has resulted in an accelerated process of extinction of the primate species. It is estimated that only about 200 At. g. vellerosus and about 1200 Al. palliata exist in the remaining small portion of their original habitat. Today, the distribution of the three primate species in Mexico is intensively and extensively fragmented, and only five potential foci for conservation exist in the country. Urgent action is required to protect the primate populations in the region of Los Tuxtlas and at the other four foci, as some of these populations may disappear by 1995.
Age assessment using cementum annulus counts and tooth wear in a free‐ranging population of Macaca mulatta
Authors: Kay Richard F. , Cant John G. H. 
Published: June 2005

AbstractEstimates were made of the tooth wear and the number of cementum annuli on lower first molars of Macaca mulatta of known age that had lived on Cayo Santiago, Puerto Rico. It is demonstrated that both these measurements are significantly correlated with age. Neither measurement by itself, however, strongly enough corrected with age to provide a reliable guide to the true age of individuals older than about 14 years, although cementum annulus counts clearly provide a more reliable guide to age determination than does wear. A combination of tooth wear and annulus number is a somewhat better predictor of age, with a multiple regression explaining 19% of the overall variance in age. As has been reported previously in tropical ungulates, there is more than one cementum annulus per year deposited on the M1S of our sample. Comparison with rainfall data indicates that the number of dry intervals in the animal's life corresponds on a one‐to‐one basis with the number of annuli. It is hypothesized that such dry intervals cause nutritional stress, which in turn is reflected in periods of arrested or slowed growth in the tooth cementum. Also, more annuli are formed per year on the teeth of males than those of females. Stress engendered by intermale competition may play a role in this phenomenon.
Patterns of reproduction and mortality in two captive colonies of hanuman langur monkeys (Presbytis entellus)
Authors: Harley Diahan 
Published: June 2005

AbstractLongitudinal reproductive and mortality data collected from two colonies of Hanuman langur monkeys (Presbytis entellus) in California (University of California, Berkeley; San Diego Zoo) are presented. Approximately 10 years of data from each facility reveal that langur monkey females reach reproductive maturity between 3 and 5 years and have median birth intervals, following the birth of a live infant that survives beyond 9 months, of approximately 15.5 months. Births are not seasonal at either facility and pregnancy failure rates at UCB are approximately 30%. Mortality of subadults was highest during the neonatal period (<30 days), and probability of Sarvivorship at 5 years is between .41 and .50. Observed differences and similarities in patterns of reproduction and mortality between the two colonies and field populations are discussed.
The effects of feedback lighting on the circadian drinking rhythm in the diurnal new world primate Saimiri sciureus
Authors: Ferraro James S. , Sulzman Frank M. 
Published: June 2005

AbstractFeedback lighting provides illumination primarily during the subjective night (i.e., the photosensitive portion of the circadian cycle) in response to a given behavior. This technique has previously been used to test the nonparametric model of entrainment in nocturnal rodents. In three species (Rattus norvegicus, Mesocricetus auratus, and Mus musculus), the free‐running period of the locomotor activity rhythm was similar whether the animals were exposed to continuous light or discrete light pulses occurring essentially only during the subjective night (i.e., feedback lighting). In the current experiments, feedback lighting was presented to squirrel monkeys so that light fell predominately during the subjective night. Feedback lighting was linked to the drinking behavior in this diurnal primate so that when the animal drank, the lights went out. Despite this seemingly adverse predicament, the monkeys maintained regular circadian drinking rhythms. Furthermore, just as the period of the free‐running activity rhythms of nocturnal rodents exposed to continuous light or feedback lighting were similar, the period of the drinking rhythms of the squirrel monkeys in continuous light and feedback lighting were comparable (25.6 ± 0.1 and 25.9 ± 0.1 hours, respectively), despite a substantial decrease in the total amount of light exposure associated with feedback lighting. The free‐running period of monkeys exposed to continuous dark (24.5 ± 0.1 hours) was significantly shorter than either of the two lighting conditions (P < 0.001). The results presented for the drinking rhythm were confirmed by an examination of the temperature and activity rhythms. Therefore, discrete light pulses given predominately during the subjective night are capable of simulating the effects of continuous light on the free‐running period of the circadian rhythms of a diurnal primate. The response of squirrel monkeys to feedback lighting thus lends further support for the model and suggests that the major entrainment mechanisms are similar in nocturnal rodents and diurnal primates.
Aging and immunity in nonhuman primates: I. Effects of age and gender on cellular immune function in rhesus monkeys (Macaca mulatta)
Authors: Ershler William B. , Coe Christopher L. , Gravenstein Stefan , Schultz Kevin T. , Klopp Roger G. , Meyer Michael , Houser W. Daniel 
Published: June 2005

AbstractImmunity declines with advancing age. Lymphocyte proliferation, natural killer cell activity, and antibody response to tetanus toxoid vaccination were evaluated in cohorts of rhesus monkeys (Macaca mulatta) aged 2–36 years in order to characterize senescent changes in immune function. The results were analyzed in accordance with host age. Lymphocyte proliferation was generally low in older monkeys, especially males. Lymphocytes from old male monkeys responded significantly less to test mitogens than did those of old female (P<.05) or young males and females (P<.01). Natural killer cell function was similarly decreased in old monkeys; however, for this function there was no apparent gender difference. Antibody response to tetanus vaccine was less in older monkeys but was also low in several of the younger moskeys. These data confirm our expectation that, like other mammalian species, the rhesus monkey shows a decline in immune function with age and demonstrate further that the changes are more marked in males. Rhesus monkeys, therefore, are suitable for the investigation of mechanisms of immune senescence.