RESUMEN
According to the Americans with Disabilities Act (1990), couples with blood-borne viruses that lead to infectious disease cannot be denied fertility treatment as long as the direct threat to the health and safety of others can be reduced or eliminated by a modification of policies or procedures. Three types of infectious patients are commonly discussed in the context of fertility treatment: those with human immunodeficiency virus (HIV), hepatitis C or hepatitis B. Seventy-five per cent of hepatitis C or HIV positive men and women are in their reproductive years, and these couples look to assisted reproductive techniques for risk reduction in conceiving a pregnancy. In many cases, only one partner is infected. Legal and ethical questions about treatment of infectious patients aside, the question most asked by clinical embryologists and andrologists is: "What are the laboratory protocols for working with gametes and embryos from patients with infectious disease?" The serostatus of each patient is the key that informs appropriate treatments. This guidance document describes protocols for handling gametes from seroconcordant and serodiscordant couples with infectious disease. With minor modifications, infectious patients with stable disease status and undetectable or low viral load can be accommodated in the IVF laboratory.
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Infecciones por VIH/prevención & control , Guías de Práctica Clínica como Asunto , Técnicas Reproductivas Asistidas , Criopreservación , Combinación Emtricitabina y Fumarato de Tenofovir Disoproxil/uso terapéutico , Femenino , Fertilización In Vitro , Células Germinativas , Infecciones por VIH/virología , Seropositividad para VIH , Fiebre Hemorrágica Ebola/prevención & control , Fiebre Hemorrágica Ebola/virología , Hepatitis B/prevención & control , Hepatitis B/virología , Hepatitis C/prevención & control , Hepatitis C/virología , Humanos , Transmisión Vertical de Enfermedad Infecciosa , Masculino , Embarazo , Complicaciones Infecciosas del Embarazo , Riesgo , Conducta de Reducción del Riesgo , Semen , Espermatozoides/metabolismo , Carga Viral , Infección por el Virus Zika/prevención & control , Infección por el Virus Zika/virologíaRESUMEN
This article presents a pictorial history of the free-ranging colony of rhesus monkeys (Macaca mulatta) on Cayo Santiago, Puerto Rico, in commemoration of the 75th anniversary of its establishment by Clarence R. Carpenter in December 1938. It is based on a presentation made by the authors at the symposium, Cayo Santiago: 75 Years of Leadership in Translational Research, held at the 36th Annual Meeting of the American Society of Primatologists in San Juan, Puerto Rico, on 20 June 2013.
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Investigación Biomédica/historia , Etología/historia , Macaca mulatta/fisiología , Animales , Conducta Animal , Historia del Siglo XX , Historia del Siglo XXI , Puerto Rico , ReproducciónRESUMEN
Genetic studies not only contribute substantially to our current understanding of the natural variation in behavior and health in many species, they also provide the basis of numerous in vivo models of human traits. Despite the many challenges posed by the high level of biological and social complexity, a long lifespan and difficult access in the field, genetic studies of primates are particularly rewarding because of the close evolutionary relatedness of these species to humans. The free-ranging rhesus macaque (Macaca mulatta) population on Cayo Santiago (CS), Puerto Rico, provides a unique resource in this respect because several of the abovementioned caveats are of either minor importance there, or lacking altogether, thereby allowing long-term genetic research in a primate population under constant surveillance since 1956. This review summarizes more than 40 years of genetic research carried out on CS, from early blood group typing and the genetic characterization of skeletal material via population-wide paternity testing with DNA fingerprints and short tandem repeats (STRs) to the analysis of the highly polymorphic DQB1 locus within the major histocompatibility complex (MHC). The results of the paternity studies also facilitated subsequent studies of male dominance and other factors influencing male reproductive success, of male reproductive skew, paternal kin bias, and mechanisms of paternal kin recognition. More recently, the CS macaques have been the subjects of functional genetic and gene expression analyses and have played an important role in behavioral and quantitative genetic studies. In addition, the CS colony has been used as a natural model for human adult-onset macular degeneration, glaucoma, and circadian rhythm disorder. Our review finishes off with a discussion of potential future directions of research on CS, including the transition from STRs to single nucleotide polymorphism (SNP) typing and whole genome sequencing.
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Genética/historia , Macaca mulatta/genética , Animales , Historia del Siglo XX , Historia del Siglo XXI , Puerto RicoRESUMEN
Cayo Santiago is the oldest continuously operating free-ranging rhesus monkey colony in the world. Population control of this colony has historically been carried out by periodic live capture and removal of animals. However, the effect of such a strategy on the size, growth rate, age structure, and sex ratio of the population has not been analyzed. This study reviews past removal data and uses a population projection model to simulate the effects of different removal schemes based on Cayo Santiago demographic data from 2000-2012. The model incorporates negative density-dependence in female fertility, as well as male and female survival rates, to determine the population-level effects of selective removal by age and sex. Modeling revealed that removal of sexually immature individuals has negligible effects on the population dynamics explaining why with an initial population of 1309 in 2000 and annual removals of immature monkeys a mean annual population growth rate of 12% and a final population size of â¼1,435 individuals by 2012 (â¼0.009 animal/m(2) ) was observed. With no removals, the population is expected to exhibit dampened oscillations until reaching equilibrium at â¼1,690 individuals (â¼0.0111 animal/m(2) ) in 2,100. In contrast, removal of adult females (≥4 yrs) would significantly reduce the population size, but would also promote an increase in population growth rate due to density feedback. A maximum annual production of 275 births is expected when 550 adult females are present in the population. Sensitivity analyses showed that removing females, in contrast to controlling their fertility through invasive treatments would contribute the most to changes in population growth rate. Given the density compensation on fertility, stabilizing the population would require removing â¼80% of the current population of adult females. This study highlights the importance of addressing the population-level density effects, as well as sensitivity analyses, to optimize management strategies.
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Conservación de los Recursos Naturales , Macaca mulatta/fisiología , Animales , Demografía , Femenino , Masculino , Modelos Biológicos , Densidad de Población , Dinámica Poblacional , Crecimiento Demográfico , Puerto RicoRESUMEN
Reproductive synchrony and the consequent clustering of births are hypothesized to be regulated by seasonal changes in rainfall and food availability. Such climate-related seasonality is, however, questionable in tropical populations occupying temporally invariant habitats year round. Using the long-term data of the Cayo Santiago rhesus macaques from 1973 to 2013, this study distinguishes synchrony (a greater than chance clustering of births) from seasonality (a cluster of births during a period of the year when abiotic conditions are favorable) and shows that females are highly synchronized (>72% of births in a 3-month period) but the effects of environmental zeitgebers on reproduction are overridden by biological factors. Specifically, biotic and abiotic factors including (i) loss of immature offspring; (ii) population density; (iii) age at delivery; (iv) rainfall; and (v) changes in colony management were modeled in relation to the annual onset of births and the median birth date. Females experiencing loss of immature offspring had an interbirth interval of <365 days in average and the proportion of these females increased up to 48% due to changes in colony management overtime, although reproductive synchrony increased with increasing population density. A secular trend in both the onset of births and the median date of birth is documented and the model predicts that the median birth date will advance across all calendar-based seasons by 2050. The secular trend in reproduction appears to be triggered by changes in the age at delivery of females, the absence of physiological constraints from maternal investment due to offspring loss, shorter interbirth interval, and a higher degree of coordination due to increasing population density. This study challenges the reproductive phenology previously described for rhesus macaques highlighting the importance of long-term studies in addressing the ultimate causes of reproductive synchrony.
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Macaca mulatta/fisiología , Reproducción , Factores de Edad , Animales , Femenino , Masculino , Puerto Rico , Estaciones del AñoRESUMEN
While osteopenia (OPE) and osteoporosis (OPO) have been studied in various species of aging nonhuman primates and extensively in ovariectomized rhesus and cynomolgus macaques, there is virtually no information on the effects of castration on the skeleton of male nonhuman primates. Most information on castrated male primates comes from a few studies on the skeletons of eunuchs. This report used a subset of the Caribbean Primate Research Center's (CPRC) Cayo Santiago (CS) rhesus macaque skeletal collection to qualitatively and quantitatively compare the bone mineral density (BMD) of castrated and age-matched intact males and, thereby, determine the long-term effects of castration (orchidectomy) on bone. Lumbar vertebrae, femora, and crania were evaluated using dual-energy X-ray absorptiometry (DEXA or DXA) and digital radiography augmented, when fresh tissues were available, with autoradiography and histology. Results confirmed physical examinations of long bones that castration causes changes in the skeleton of male rhesus macaques similar to those found in eunuchs, including OPE and OPO of the vertebrae and femora, thinning of the skull, and vertebral fractures and kyphosis of the spine more severe than that caused by normal aging alone. Also like eunuchs, some castrated CS male rhesus monkeys had a longer life span than intact males or females. Based on these results and the effects of castration on other tissues and organs of eunuchs, on behavior, hormone profiles and possibly on cognition and visual perception of human and nonhuman primates, and other mammals, castrated male rhesus macaques should be used with caution for laboratory studies and should be considered a separate category from intact males. Despite these caveats, the castrated male rhesus macaque should make an excellent animal model in which to test hormone replacement therapies for boys and men orchidectomized for testicular and prostate cancer.
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Densidad Ósea , Fémur/fisiología , Vértebras Lumbares/fisiología , Macaca mulatta/fisiología , Orquiectomía/veterinaria , Cráneo/fisiología , Absorciometría de Fotón/veterinaria , Animales , Autorradiografía/veterinaria , Masculino , Puerto Rico , Intensificación de Imagen RadiográficaRESUMEN
Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys on Cayo Santiago prior to 1985 when the entire colony was given its first dose of tetanus toxoid. The immediate reduction in mortality that followed tetanus toxoid inoculation (TTI) has been documented, but the long-term demographic effects of eliminating tetanus infections have not. This study uses the Cayo Santiago demographic database to construct comparative life tables 12 years before, and 12 years after, TTI. Life tables and matrix projection models are used to test for differences in: (i) survival among all individuals as well as among social groups, (ii) long-term fitness of the population, (iii) age distribution, (iv) reproductive value, and (v) life expectancy. A retrospective life table response experiment (LTRE) was performed to determine which life cycle transition contributed most to observed changes in long-term fitness of the population post-TTI. Elimination of clinical tetanus infections through mass inoculation improved the health and well-being of the monkeys. It also profoundly affected the population by increasing survivorship and long-term fitness, decreasing the differences in survival rates among social groups, shifting the population's age distribution towards older individuals, and increasing reproductive value and life expectancy. These findings are significant because they demonstrate the long-term effects of eradicating a major cause of mortality at a single point in time on survival, reproduction, and overall demography of a naturalistic population of primates.
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Demografía , Esperanza de Vida , Macaca mulatta/inmunología , Enfermedades de los Monos/prevención & control , Tétanos/prevención & control , Animales , Femenino , Tablas de Vida , Masculino , Enfermedades de los Monos/inmunología , Puerto Rico , Reproducción/fisiología , Estudios Retrospectivos , Tétanos/veterinaria , Toxoide Tetánico/inmunología , Tiempo , VacunaciónRESUMEN
Density-dependence is hypothesized as the major mechanism of population regulation. However, the lack of long-term demographic data has hampered the use of density-dependent models in nonhuman primates. In this study, we make use of the long-term demographic data from Cayo Santiago's rhesus macaques to parameterize and analyze both a density-independent and a density-dependent population matrix model, and compare their projections with the observed population changes. We also employ a retrospective analysis to determine how variance in vital rates, and covariance among them, contributed to the observed variation in long-term fitness across different levels of population density. The population exhibited negative density-dependence in fertility and the model incorporating this relationship accounted for 98% of the observed population dynamics. Variation in survival and fertility of sexually active individuals contributed the most to the variation in long-term fitness, while vital rates displaying high temporal variability exhibited lower sensitivities. Our findings are novel in describing density-dependent dynamics in a provisioned primate population, and in suggesting that selection is acting to lower the variance in the population growth rate by minimizing the variation in adult survival at high density. Because density-dependent mechanisms may become stronger in wild primate populations due to increasing habitat loss and food scarcity, our study demonstrates that it is important to incorporate variation in population size, as well as demographic variability into population viability analyses for a better understanding of the mechanisms regulating the growth of primate populations.
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Macaca mulatta/fisiología , Animales , Fertilidad , Densidad de Población , Dinámica Poblacional , Puerto RicoRESUMEN
This paper reports the results of an eight-year study of seasonal reproduction in the free-ranging colony of rhesus monkeys on Cayo Santiago, Puerto Rico. There was a significant correlation between the start of the annual spring rainy season and the estimated median conception date (r = .94, p < .001) and median birth date (r = .94, p < .001). Conceptions followed the commencement of spring rains by 70 days. Significant and negative correlations were found between the number of days from the start of the rains to the first conception (r = -.93, p < 0.01) and median conceptions (r = -.91, p < .01). When spring rains were delayed, the interval between the onset of rains and conceptions decreased linearly. The median birth date for the Cayo Santiago population was accurately predicted for 1984 using two methods. When results from Cayo Santiago were applied retrospectively to data from the colony of rhesus monkeys near La Parguera, Puerto Rico, it explained the three-month difference in seasonality of reproduction between the two populations located at the same latitude (18°N). Photoperiod, as a function of latitude, appears to set the temporal limits of seasonal reproduction in rhesus macaques, while the onset of spring rains regulates reproductive activity within that range, at least in the Cayo Santiago population. The biological channel through which the effect is mediated has not been identified.
RESUMEN
Secondary sex ratios (SSR) were calculated from 1,385 offspring delivered by 372 females in the Cayo Santiago population of free-ranging rhesus monkeys (Macaca mulatta) from 1976 through 1984. The SSR for the entire colony ranged from 0.86 to 1.46 males per female (combined total: 1.08), but no significant difference was observed (P > .05). SSR values were compared among the troops for each year. The SSR differed significantly among the six social groups (P < .05) only in 1978. The annual SSR of each troop was compared over 9 years. Significant variation was found only in group O. The annual SSR was significantly skewed (P < .05, males > females) for three troops in 3 separate years. The SSR did not vary according to troop rank. No significant difference was found among the 17 matrilines of the population, but comparison of matrilines within each social group revealed a significant difference in the SSR (P < .02) for the three matrilines in group I. This was due to the significantly skewed SSR (P = .0080, females > males) of the DM genealogy in that troop. SSR values were not related to matrilineal rank. Individual dominance rank did not bias the SSR. Complete reproductive histories for 266 females showed no evidence of significantly skewed SSR values. Age-related effects on the SSR were examined by using cross-sectional and cohort-based analyses. The SSR did not vary significantly (P > .05) with maternal age, but it was significantly skewed (P < .05) toward males at the ages of 5 and 9 years. Parity had no significant effect (P > .05) on SSR values. Wide variation occurred in the SSR of the Cayo Santiago population. Rank-related adjustment of the SSR at the level of the troop, matriline, or individual, as reported in short-term studies of other primate social groups, may reflect normal annual variation in the SSR evident only from longitudinal observations of large multigroup primate populations.
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Sixty-four male and 33 female free-ranging rhesus monkeys (Macaca mulatta) from one of six social groups on the island of Cayo Santiago, Puerto Rico, were surveyed to establish normal values for the hemogram and serum biochemical and electrolytes for the colony. Mean values (± 1 SD) are reported by sex for each of three age groups (2-3, 4-9 and ≥ 10 years). All adult females (≥ 4 years) were pregnant. There were significant differences for a number of variables compared to the range reported in the existing literature, and among the age and sex groups in the sampled population.
RESUMEN
Tetanus is a major cause of death in the free-ranging rhesus moonkey colony on the island of Cayo Santiago, Puerto Rico. During the five-year period of observation (July 1, 1976 through June 30, 1981), the mean annual tetanus mortality rate (± 1 SD) was 1.74% (±0.15). The mean annual total mortality rate was 6.77% (±0.78). The tetanus mortality rate varied sigificantly (P < 0.005) among the six troops on the island. Clinically confirmed tetanus accounted for 24.68% of the 231 deaths which occurred on the island during the study. Although the base population increassed from 479 to 914 monkeys or 90.8% in five years, there were no significant changes in either the total or the tetanus mortality rates. The mean age of tetanus deaths was 6.9 years (±3.9) in the males and 7.1 years (±5.4) in females. The mean age-specific tetanus mortality rate increased with age. Of the 67 confirmed tetanus cases, 57 proved fatal (26 males, 31 females) for a case fatality rate of 85.1%. There was no significant sex difference in the tetanus mortality rate. No confirmed cases of neonatal tetanus were observed. Infection of juveniles and adults of both sexes occurred chiefly through septic wounds, but postpartum infection of females was also noted. The peak incidence of tetanus deaths for both sexes occurred during the mating season of the annual reproductive cycle, as a consequence of increased levels of aggression and subsequent wounding. The diagnosis of tetanus was based solely on the clinicla signs and was characterized by early behavioural abnormalities consisting of torpor, reluctance to interact with other animals, inability to prehend food, inordinate thirst, difficulty in swallowing, progressive stiffening and adduction of the pectorla limbs, bipedeal running, "kangaroo hopping," "toppling over," and pilo-erection. As the disease advanced, severely affected individuals developed the classic human triad of tetanus symptomatology:trismus (lockjaw), extensor rigidity, and opisthotonus, which progressed in most cases to status epilepticus and death from respiratory paralysis or physical exhaustion. The course of the disease in fatal cases ranged in duration from 24 hours to ten dyas. Obese monkeys with mild cases of tetanus were the most likely to recover with some taking as long as a month to return to normal condition and regain body weight. Of ten recoveries, six were female and four male. Multiple cases were observed in one adult male, indicating that previous infections do not necessarily confer immunity to future attacks. Survivous did not have demonstrable antitoxin titers to Clostridium tetani toxin, thus confirming that tetanus is a nonimmunizing disease. One half of an annual birth crop of thesus monkeys inoculated with tetanus toxoid at the age of one year had protective levels of tetanus antitoxin seven years postinoculation. However, the immunization program had no significant effect on either the total or tetanus motality rates during the study.
RESUMEN
Tetanus was a major cause of mortality in the free-ranging population of rhesus monkeys (Macaca mulatta) on Cayo Santiago. From 1977 to 1984 the mean (±1 SD) annual total mortality rate (excluding neonatal deaths within 48 h postpartum, abortions, and stillbirths) was 6.39% ± .94%, and the mean annual tetanus mortality rate was 1.33% ± .45%. Tetanus deaths accounted for 19.5% of the total mortality in the colony. In 1985, all monkeys on the island, except infants and six adult monkeys, were given primary inoculations of tetanus toxoid. The following year, boosters were administered, and yearlings received primary inoculations. One fatal case of tetanus and one recovery from mild disease occurred in uninoculated adult monkeys in 1985, but no additional cases have been observed since. For 1985-1986 the mean annual total mortality rate was 3.69% ± .05%, and the mean annual tetanus mortality rate was .08% ± .08%. Thus, during the 2 years after inoculation against tetanus, the mean annual total mortality rate and the mean annual tetanus mortality rate declined by 42.2% and 94.0%, respectively, when compared to the 8-year period (1977-1984) prior to inoculation. These differences were significant [(χ2 = 12.48; P < .005), (χ2 = 16.94; P < .005)]. The elimination of tetanus infections through mass inoculation of the Cayo Santiago colony is expected to have a profound impact on the demography of the population by increasing the rate of population growth, by decreasing the differential rates of increase of the component social groups, and by changing the age distribution of the population.
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OBJECTIVE: To identify a gene expression signature in human cumulus cells (CCs) predictive of pregnancy outcome across multiple clinics, taking into account the clinic and patient variations inherent in IVF practice. DESIGN: Retrospective analysis of single human cumulus-oocyte complexes with the use of a combined microarray and quantitative reverse-transcription polymerase chain reaction (qRT-PCR) approach. SETTING: Multiple private IVF clinics. PATIENT(S): Fifty-eight patients. Samples from 55 patients underwent qRT-PCR analysis, and samples from 27 patients resulted in live birth. INTERVENTION(S): Gene expression analysis for correlation with pregnancy outcome on individual human CCs collected immediately after oocyte retrieval. Pregnancy prediction analysis used leave-one-out cross-validation with weighted voting. MAIN OUTCOME MEASURE(S): Combinatorial expression of 12 genes in 101 samples from 58 patients. RESULT(S): We found a set of 12 genes predictive of pregnancy outcome based on their expression levels in CCs. This pregnancy prediction model had an accuracy of 78%, a sensitivity of 72%, a specificity of 84%, a positive predictive value of 81%, and a negative predictive value of 76%. Receiver operating characteristic analysis found an area under the curve of 0.763 ± 0.079, significantly greater than 0.5 (random chance prediction). CONCLUSION(S): Gene expression analysis in human CCs should be considered in identifying oocytes with a high potential to lead to pregnancy in IVF-ET.
Asunto(s)
Células del Cúmulo/fisiología , Fertilización In Vitro/métodos , Perfilación de la Expresión Génica , Oocitos/fisiología , Resultado del Embarazo/genética , Adulto , Células del Cúmulo/citología , Implantación del Embrión , Femenino , Marcadores Genéticos , Pruebas Genéticas , Humanos , Nacimiento Vivo , Análisis de Secuencia por Matrices de Oligonucleótidos , Oocitos/citología , Embarazo , Estudios Retrospectivos , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Sensibilidad y EspecificidadRESUMEN
HIV-serodiscordant couples wishing to conceive often seek assisted reproduction, during which spermatozoa from infected men are washed to minimize the risk of HIV transmission to partner and fetus. We sought to improve this method by adding a microbicide, PPCM, as an HIV prophylactic. HIV-1 (BaL) inhibition by PPCM appears irreversible and independent of added Ca(2+). Without added Ca(2+), PPCM (≤10 mg/mL, ≤90 min), a stimulus of Ca(2+)-dependent acrosomal loss, has no effect on sperm motility, forward progression, or acrosomal status. PPCM-treated (10 mg/mL) sperm retain their ability to acrosome react when Ca(2+) is added. Sperm DNA integrity/function is unaffected by PPCM (≤10 mg/mL). Adding PPCM (5 mg/mL, 30 min) to washing media reduces infectivity (viral antigen p24 and RNA) of ex-vivo HIV-infected semen by 3-4 Logs compared with washing alone. Sperm washing with appropriate extracellular Ca(2+) levels and PPCM is significantly more effective than washing alone at reducing HIV infectivity.
RESUMEN
Prior to 1985 tetanus was a major cause of mortality in the free-ranging colony of rhesus monkeys on Cayo Santiago, accounting for almost a quarter of annual deaths. In 1985 and 1986 all animals (except infants) received primary and booster doses, respectively, of tetanus toxoid. In subsequent years primary immunizations were given to all yearlings, and boosters were administered to all 2-year-old animals during the annual capture of the colony. The main objectives of the tetanus immunization program were to reduce the pain and suffering caused by tetanus infections and to decrease mortality in the colony. Other objectives were to evaluate the efficacy of the two-dose tetanus toxoid immunization protocol and to determine whether additional boosters might be required to provide adequate long-term protection against tetanus infections. The immediate effect of the mass immunization program was the elimination of clinical tetanus infections in the population and a 42.2% reduction in the overall mortality rate. Since the immunization program began, no cases of tetanus have been observed in the colony, except in two unimmunized infants, and it has not been necessary to give tertiary injections of tetanus toxoid to maintain protection against infection. A sample collected in 2004 of the original cohort of monkeys immunized in 1985 and 1986 showed that 93.3% (14/15) had protective tetanus antibody titers (>0.01 IU/ml) at the ages of 20-23 years, which is close to the life expectancy of the Cayo Santiago rhesus macaques. Two intramuscular doses of tetanus toxoid provided long-term, if not lifelong, protection against tetanus for rhesus monkeys living in a tropical clime where tetanus is enzootic and the risk of infection is great.
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Anticuerpos Antibacterianos/sangre , Macaca mulatta/inmunología , Enfermedades de los Monos/prevención & control , Toxoide Tetánico/inmunología , Tétanos/veterinaria , Animales , Femenino , Masculino , Enfermedades de los Monos/epidemiología , Enfermedades de los Monos/inmunología , Tétanos/inmunología , Tétanos/prevención & control , VacunaciónRESUMEN
La relación entre el colesterol sérico total (STC) y el rango social de dominio se investigó en machos adultos (>- 5 años) de una sola tropa formada en un ambiente fibre y natural de monos rhesus (Macaca mulatta) en Cayo Santiago, Puerto Rico. El rango de dominio, la edad y el peso corporal no se correlacionaron con STC, ni se correlacionó con la edad ni peso corporal. La media (ñ 1 SD) fue de 154.0 ñ 27.0 mg/dl. Siete de los 34 machos del muestreo tenían niveles de STC (189.1 ñ 4.3 mg/dl) mayores de 1 SD sobre la mediana para todos los machos. Estos monos no se diferenciaron significativamente en edad ni peso corporal entre ellos ni de los otros machos del estudio, pero cinco de los siete monos con STC alto eran machas de alto rango en el grupo y siete de ocho monos con STC (115.6 ñ 5.8 mg/dl) 1 SD o más por debajo de la media para todos los machos eran de bajo rango. La diferencia fue significativa (p<.05, "Fisher's Exact Test")
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Animales , Masculino , Colesterol/sangre , Macaca mulatta/sangre , Macaca/sangre , Predominio Social , Conducta Animal , Estrés Fisiológico/fisiopatologíaRESUMEN
Según estadísticas médicas en Estados Unidos, cerca del 15% de las parejas en edad reproductiva no pueden concebir de forma natural. Mayormente por razones de cambios en estilos de vida, el número de parejas con problemas de reproducción ha ido en aumento en años recientes. A sólo trece años del nacimiento del primer bebé de probeta, avances en el campo de la reproducción humana han logrado crear una gran gama de alternativas para ayudar a parejas infértiles a concebir un bebé saludable. En conjunto, estas técnicas se denominan Técnicas de Reproducción Asistida (ART por sus siglas en inglés) e incluyen: la fertilización in vitro (IVF), la transferencia de gametos intratubal (GIFT), la transferencia intratubal de cigotos (ZIFT), la transferencia tubal de embriones (TET), la donación de gametos o embriones, la criopreservación y la micromanipulación. Aún nos queda mucho por aprender pero la habilidad de fertilizar óvulos in vitro y el sostener la vida embriónica extracorpórea temprana, son una realidad de nuestro presente. Contrario a la creencia de que con estas técnicas estamos creando vida, con ellas lo que hemos logrado es remover algunas de las barreras que las diferentes causas de infertilidad imponen sobre la creación de la vida. Cerca de treinta mil bebés han nacido alrededor del mundo ayudados por estas técnicas. En años venideros el excitante campo de la reproducción humana promete traer más y mejores esperanzas al creciente número de parejas infértiles alrededor del mundo