Changes in plasma lipoproteins and liver lipids in neonatal rats

Transient increases in triglycerides and cholesterol were found in rat liver immediately after birth. Plasma VLDL and HDL increased after birth and reached a plateau after one week of life. The content of cholesterol ester was low at birth in all lipoproteins and increased in LDL and HDL during the first week of life. After birth, VLDL became enriched in apolipoproteins C and E, whereas HDL was enriched in apolipoprotein C and depressed in apolipoprotein E. The developmental changes in plasma lipoprotein levels and compositions in rats during the first week of life are comparable to those described in humans.     

Parturition in Macaca nemestrina

Measures were taken on 187 pregnancies of 104 pig-tailed macaques (Macaca nemestrina) to document the normative course of parturition and to identify factors correlated with high risk for poor pregnancy outcomes. Analyses involved weekly physical examinations and diurnal sleep-wake-fulness patterns during trimester three; behavior during labor and delivery; and newborn sex, Apgar ratings, birthweight, and reflexes. Onset of labor was estimated at three–four hours before delivery, the time when circadian activity level first deviated from its predelivery pattern. Active labor averaged 92 minutes, and was characterized by increased uterine contractions and manipulation of the vaginal area. The modal delivery time was 2200 hr through 2400 hr. Most infants emerged from the vulva in a cranial-anterior-anterior presentation, with only a brief pause between head expulsion and complete emergence. Females with histories of poor pregnancy outcomes were more likely to deliver after midnight and showed less labor-unique behavior than females with good outcome histories. Infants of high-risk females that were delivered after midnight had lower Apgar scores and more bruising than infants of low-risk females delevered before of after midnight, suggesting that high-risk females may have more difficult deliveries. Overall, the results show that simple direct observations of parturition can yield important quantitative normative information that is correlated with reproductive risk factors.     

Hemostatic profile during late pregnancy and early postpartum period in mares

Hemostasis is a physiological process that prevents excessive blood loss and represents a protective mechanism at the time of delivery. Peripartum hemorrhage is a recurring hazardous condition to mare's health; therefore, we aimed to study mares' hemostatic profile to investigate whether physiological adjustments occur during late pregnancy and early postpartum. Fifteen pregnant mares have been monitored from the 34th week of pregnancy until the third week after foaling. Fifteen nonpregnant mares were used as control group. Jugular blood samples were analyzed for platelet count (Plt), prothrombin time (PT), activated partial thromboplastin time (aPTT), and fibrinogen (Fb). Platelet count showed significant changes at foaling (P < 0.05) and a negative correlation (r = −0.968; P = 0.032) with postpartum. Prothrombin time changed (P < 0.05) showing a significant correlation (r = 0.675; P = 0.016) with late pregnancy. Fibrinogen concentrations changed throughout the experimental period (P < 0.0001). The linear regression model revealed a positive correlation (r = 0.9210; P < 0.0001) between Fb and late pregnancy and a negative correlation (r = −0.9583; P = 0.042) between Fb and early postpartum. The shortening in PT recorded in the imminence of parturition along with the increase in Plt and Fb at foaling might reflect a physiological hypercoagulable state that constrains excessive bleeding, enhancing mares' odds of surviving. Our research improves the knowledge about blood coagulation in periparturient mares providing specific information on routine coagulation tests that may support in monitoring mare's hemostatic profile during late pregnancy and early postpartum.     

Pregnancy-associated glycoprotein concentrations during pregnancy and the postpartum period in Azawak Zebu cattle

Specific RIA systems were developed and used to measure pregnancy-associated glycoprotein (PAG) concentrations during gestation and the postpartum period in Azawak Zebu cows. Twelve females were palpated per rectum and diagnosed as pregnant. Blood samples were taken at 5-10-day intervals from approximately Week 8 of gestation until Week 10 postpartum (pp). One Zebu cow (Z15) initially diagnosed as pregnant showed PAG concentrations lower than the assay sensitivity (<0.20 ng/ml) and did not calve. Another cow (ZSand) showed abnormally high PAG concentrations during gestation and was excluded from the general PAG profile. The 10 other Zebu cows exhibited a very similar PAG profile. In these animals, concentrations increased progressively from Week 8 to 35 of gestation (from 6.0+/-4.2 to 196.0+/-34.8 ng/ml), remaining relatively constant until Week 39 (210.8+/-74.8 ng/ml), when they increased sharply to reach their highest level (1095.6+/-607.2 ng/ml) at around parturition. After delivery, PAG concentrations declined significantly (P<0.05) until Week 2 postpartum (348.4+/-85.6 ng/ml) and slowly until Week 10 postpartum. Our results revealed that the PAG pattern in Zebu cattle was similar to those of taurine breeds during the first two trimesters of pregnancy, but differed in the peripartum period.     

Changes in the surface charge of plasma lipoproteins during their auto-oxidation

Low density lipoproteins (LDL) and high density lipoproteins (HDL) surface potential (charge) changes were studied upon autooxidation, using positively charged spin probes. Lipid peroxidation product accumulation in LDL and HDL suspensions was found to be accompanied by a significant reduction in their surface area associated with a decreased negative surface charge, and probably, deposition of lipid peroxidation polar products and/or surface charge redistribution as a result of lipoprotein autooxidative modification.     

Aggression in pigtailed macaque (Macaca nemestrina) breeding groups affects pregnancy outcome

Past research has shown that aggressive behaviors can affect female reproductive outcome in nonhuman primate captive breeding programs. In this study, aggressive behaviors were recorded in a colony of pigtailed macaque monkeys (Macaca nemestrina) and related to pregnancy outcome. For 22 weeks, behavioral data were collected from nine breeding groups, consisting of zero to one male (some males were removed after a cycle of conceptions for husbandry reasons) and four to eight females. Observations included all occurrences of 11 aggressive behaviors during 15 min observation sessions, 1-3 times a week. Mean weekly aggression levels during the study period were determined for each group as well as for each pregnancy. Aggression data were summarized with Principal Components Analyses. Results indicate that pigtailed macaque aggression falls into five distinctive categories: warn, engage, threaten, pursue, and attack. Breeding groups differed in their levels of aggression, even after controlling for group size, presence of a sire, and group stability. Levels of the five aggression categories were found to affect the probability that a pregnancy ended in either a natural birth of a live infant, a clinical intervention producing a live infant, or a nonviable outcome. The predictive value of aggression was significant when clinical interventions were included as possible reproductive outcomes. Behavioral observation of captive groups could identify "risk" conditions affecting pregnancy outcome and the requirement for clinical intervention.     

Weaning, body weight, and postpartum amenorrhea duration in pigtailed macaques (Macaca nemestrina)

Early permanent infant separation or weaning decreases the time interval between pregnancies and interbirth intervals for many female primates. At least part of the interpregnancy interval consists of postpartum amenorrhea, a period of non-menstruation lasting from the time of birth until the female begins to ovulate. This study investigated the effects of weaning age and dam's body weight on the duration of the interval between pregnancies, the duration of postpartum amenorrhea, and the number of cycles to conception in a year-round breeder. Female pigtailed macaques (Macaca nemestrina) have an observable perineal swelling that fluctuates throughout the menstrual cycle and provides a means of detecting ovulation. The perineal swelling records of socially housed pigtailed macaques were studied from July 1996 to September 1998. Postpartum amenorrhea data were obtained on 44 females who gave birth to normal, viable infants. As weaning age increased and dam's weight decreased, postpartum amenorrhea, and consequently the interval between pregnancies, increased in duration. The interpregnancy interval consisted almost entirely of the postpartum amenorrhea phase. Our finding that a higher dam's body weight decreased the length of postpartum amenorrhea duration lends support to the hypothesis that a minimum body weight is necessary for menstrual cycles to occur. Most females became pregnant on their first ovulation regardless of weaning age and whether or not they were carrying an infant. As the weaning age of the infant and the dam's weight increased, ovulation went from occurring after separation to occurring before separation.     

Cell-mediated immunity in human pregnancy: Changes in lymphocyte reactivity during pregnancy and postpartum.

The function of thymus-dependent lymphocytes (T lymphocytes) was studied in women during pregnancy and labor and postpartum by evaluating the blastogenesis of peripheral lymphocytes, which were stimulated with phytohemagglutin-P (PHA-P) in both whole-blood semimicroculture and purifed lymphocyte culture. Data from 353 random samples (203 women) and 50 serial specimens from 10 women revealed that PHA-P induced-lymphocyte blastogenesis was significantly (p less than 0.005) reduced during pregnancy and labor but rapidly returned to normal several days after artificial termination in the early stage of pregnancy as well as after full-term delivery. These results indicate that the T-lymphocyte function in maternal peripheral blood is depressed by causes related to pregnancy. It seems very likely that depressed T-lymphocyte function during pregnancy is caused by inhibitory factors in the blood plasma derived from the feto-placental unit. Questions relating to the inhibitory factors in maternal plasma are discussed.     

Morphometric analysis of Macaca nemestrina exposed to ethanol during gestation

This study was part of a multidisciplinary investigation of the effects of gestational ethanol exposure in nonhuman primates. Thirty-one pregnant Macaca nemestrina were exposed to weekly ethanol doses of 0.0, 0.3, 0.6, 1.2, 1.8, 2.5, 3.3, or 4.1 g/kg maternal weight. Dose cohorts 0.0 through 1.8 were exposed to the initial ethanol dose within 10 days postconception. Dose cohorts 2.5 through 4.1 received their initial dose after the fifth week of gestation. Morphometric analyses performed on cranial radiographs showed that animals exposed to high doses of gestational ethanol had, on average, slightly smaller, distorted crania than control animals. A dysmorphic, flat face characteristic of fetal alcohol syndrome was recognized in one animal of the 1.8 g/kg cohort. The animal that received the highest doses of gestational ethanol was microcephalic. Similar malformations were not seen with low ethanol exposures or in controls. These data suggest a pattern of cranial distortion that may be recognizable and characteristic of ethanol teratogenesis.     

Glucocorticoid receptor gene polymorphisms and disease activity during pregnancy and the postpartum period in rheumatoid arthritis

Introduction

The mechanism underlying the spontaneous improvement of rheumatoid arthritis (RA) during pregnancy and the subsequent postpartum flare is incompletely understood, and the disease course varies widely between pregnant RA patients. In pregnancy, total and free levels of cortisol increase gradually, followed by a postpartum decrease to prepregnancy values. The glucocorticoid receptor (GR) polymorphisms BclI and N363S are associated with relatively increased glucocorticoid (GC) sensitivity, whereas the 9β and ER22/23EK polymorphisms of the GR gene are associated with a relatively decreased GC sensitivity. We examined the relation between the presence of these GR polymorphisms and level of disease activity and disease course of RA during pregnancy and postpartum.

Methods

We studied 147 participants of the PARA study (Pregnancy-Induced Amelioration of Rheumatoid Arthritis study), a prospective study investigating the natural improvement during pregnancy and the postpartum flare in women with RA. Patients were visited, preferably before pregnancy, at each trimester and at three postpartum time points. On all occasions, disease activity was scored by using DAS28. All patients were genotyped for the GR polymorphisms BclI, N363S, 9β, and ER22/23EK and divided in groups harboring either polymorphisms conferring increased GC sensitivity (BclI and N363S; GC-S patients) or polymorphisms conferring decreased GC sensitivity (9β or 9β + ER22/23EK; GC-I patients). Data were analyzed by using a mixed linear model, comparing GC-S patients with GC-I patients with respect to improvement during pregnancy and the postpartum flare. The cumulative disease activity was calculated by using time-integrated values (area under the curve, AUC) of DAS28 in GC-I patients versus GC-S patients. Separate analyses were performed according to the state of GC use.

Results

GC-S patients treated with GC had a significantly lower AUC of DAS28 in the postpartum period than did GC-I patients. This difference was not observed in patients who were not treated with GCs. During pregnancy, GC-S and GC-I patients had comparable levels of disease activity and course of disease.

Conclusions

Differences in relative GC sensitivity, as determined by GR polymorphisms, are associated with the level of disease activity in the postpartum period in GC-treated patients, but they do not seem to influence the course of the disease per se.     

Measurement of excreted steroids in Macaca nemestrina

A practical method for the quantitative measurement of the estrogenic steroid estradiol-17β in the feces of pigtailed macaques (Macaca nemestrina) is described. The method, which includes homogenization, filtration, ether extraction, and sephadex purification, produces an 85.3% recovery of 3H-estradiol. Comparable recovery of 3H-progesterone (64.1%) and 3H-testoster-one (67.9%) is also obtained. Estradiol, measured by radioimmunoassay methodology, has inter- and intra-assay variations of 7.1% and 4.3%, respectively. Linearity of estradiol was checked by varying the amount of feces analyzed. Results show a correlation of 0.9945, Y = 32.526x + 0.205. Accuracy of estradiol, determined by adding radioinert estradiol to the feces before homogenization, was 98.7% with a correlation of 0.9950, Y = 1.027x ? 0.543. The menstrual cycles of several animals were analyzed and corresponded well with serum levels of estradiol-17β. Similar correspondence was obtained in matched fecal and serum samples from pregnant animals. These methods provide a practical and accurate solution to the problem of collecting hormone data in field studies without the potential complications of capture in laboratory research.