Epipubic bones in eutherian mammals from the late Cretaceous of Mongolia

An important transformation in the evolution of mammals was the loss of the epipubic bones. These are elements projecting anteriorly from the pelvic girdle into the abdominal region in a variety of Mesozoic mammals, related tritylodonts, marsupials and monotremes but not in living eutherian (placental) mammals. Here we describe a new eutherian from the Late Cretaceous period of Mongolia, and report the first record of epipubic bones in two distinct eutherian lineages. The presence of epipubic bones and other primitive features suggests that these groups occupy a basal position in the Eutheria. It has been argued that the epipubic bones support the pouch in living mammals, but epipubic bones have since been related to locomotion and suspension of the litter mass of several attached, lactating offspring. The loss of the epipubic bones in eutherians can be related to the evolution of prolonged gestation, which would not require prolonged external attachment of altricial young. Thus the occurrence of epipubic bones in two Cretaceous eutherians suggests that the dramatic modifications connected with typical placental reproduction may have been later events in the evolution of the Eutheria.     

New flexible growth function and its application to the growth of small mammals

The effects of three putative genes which contribute to age-related hearing loss (AHL genes) were evaluated using auditory brainstem response (ABR) thresholds and post-mortem cochlear histopathology in 25 recombinant BXD inbred mouse strains, originally derived from C57BL/6J (B6) and DBA/2J (D2) progenitor strains. All BXD strains showed substantial elevation of ABR thresholds and loss of spiral ganglion cells (SGCs) during the first year of life. The findings are consistent with our genetic model in which D2 and B6 inbred strains both possess the Ahl (age-related hearing loss) gene, whereas D2 possesses two additional chromosomal loci with AHL genes (Ahl2 and Ahl3). The between-strain distribution in the severity of SGC loss and ABR threshold elevations suggests that the severity of hearing loss is determined in large part by the number of AH L genes an animal possesses and by additional genetic background effects. The present findings also demonstrate that, because BXD strains vary substantially in the rate and severity of progressive hearing loss (but are genetically closely related), they can provide powerful animal models for developmental studies of AHL.     

Pelvic ultrasonography in normal girls and in girls with pubertal precocity

Small bowel allograft rejection in large animals has yet to be well defined. There are no specific early signs of graft rejection. The present experiments were undertaken to compare acute small bowel allograft rejection in pigs with and without FK506 and also to examine the usefulness of mucosal biopsies. Thirty-six outbred Large-White pigs were divided into (1) group 1 (n = 9): nonimmunosuppressed recipients; (2) group 2 (n = 8): FK506-immunosuppressed recipients; (3) group 3 (n = 2): autotransplant controls; and (4) donors (n = 17). Orthotopic small bowel transplantations were performed with Thiry-Vella loops for daily biopsies. The survival rate of group 2 was significantly longer than that of group 1 (P < 0.05). One best survivor in group 2 was killed at postoperative day (POD) 365. Treatment by FK506 prevented rejection, but most of the pigs died of pneumonia. In group 1, rejection began on POD 3 and progressed to severe rejection rapidly within 7 days. In group 2, rejection began from POD 6 to POD 8, but either remained mild or spontaneously improved. The differences in the routine laboratory data and the tumor necrosis factor-alpha level were not evident between the groups. Histological studies of repeated graft biopsies are thus considered to be essential for detecting signs of graft rejection.     

First-trimester growth and the risk of low birth weight

BACKGROUND: Previous studies have demonstrated a correlation between first-trimester size and birth weight. It is not known, however, whether low birth weight is related to first-trimester growth. We sought to determine whether the risk of low birth weight and birth weight that was low for gestational age is related to the size of the embryo or the fetus in the first trimester. METHODS: From a data base of ultrasound records of more than 30,000 pregnancies, we identified women who had no important medical problems, a normal menstrual history, and a first-trimester ultrasound scan in which the crown-rump length of the embryo or fetus had been measured. We examined the relation between the outcome of 4229 pregnancies and the difference between the measured and the expected crown-rump length in the first trimester, expressed as equivalent days of growth. RESULTS: A first-trimester crown-rump length that was two to six days smaller than expected was associated with an increased risk (as compared with a normal or slightly larger than expected crown-rump length) of a birth weight below 2500 g (relative risk, 1.8; 95 percent confidence interval, 1.3 to 2.4), a birth weight below 2500 g at term (relative risk, 2.3; 95 percent confidence interval, 1.4 to 3.8), a birth weight below the fifth percentile for gestational age (relative risk, 3.0; 95 percent confidence interval, 2.0 to 4.4), and delivery between 24 and 32 weeks of gestation (relative risk, 2.1; 95 percent confidence interval, 1.1 to 4.0), but not with delivery between 33 and 36 weeks (relative risk, 1.0; 95 percent confidence interval, 0.7 to 1.5). CONCLUSIONS: Suboptimal first-trimester growth may be associated with low birth weight, low birth-weight percentile, and premature delivery.     

Evaluation of triplet growth status at birth using individualized growth assessment: comparison with conventional methods and development of a new classification system

A new growth classification system for triplets based on individual growth curve standards provides new information on the growth status of triplets at birth. OBJECTIVES. The objectives of this study were to characterize growth outcome at birth in triplet pregnancies using Individualized Growth Assessment methods, and to compare these results to conventional methods of growth outcome evaluation. STUDY DESIGN. Rossavik growth models derived from second-trimester ultrasound measurements were used to predict the birth characteristics of 21 triplet neonates. Actual measurements of weight, head, abdominal, and thigh circumferences at birth were compared to population standards and to predicted values, the latter by calculation of Growth Potential Realization Index (GPRI) values. GPRI values were calculated using singleton (measurement procedure correction) and triplet (measurement procedure correction+decreased soft tissue deposition) correction factors (SCF, TCF). Neonatal Growth Assessment Scores (NGAS) were calculated using both sets of GPRI values. RESULTS. Three types of triplet neonates were identified. Group I (33.3%) were normal with both types of NGAS values, had very few abnormal GPRI values or anatomic measurements, and were all appropriate for gestational age. Group III (14.3%) were abnormal with both types of NGAS values, most GPRI values were abnormal, and all were small for gestational age. Group II (52.4%) had abnormal NGAS values when calculated from GPRI values determined with SCF and normal NGAS values when calculated from GPRI values determined with TCF. All but one was AGA. Almost all GPRIWT and GPRIThC values were abnormal using SCF and normal using TCF. CONCLUSION. Although growth outcome in triplet neonates can be normal (Group I) or intrauterine growth retarded (Group III), the majority are in an intermediate group (Group II) characterized by a decrease in soft tissue mass, which may or may not be pathological.     

Catecholamine release in the newborn infant at birth

Catecholamines were determined by a fluorimetric technique in umbilical blood which was collected from newborn infants immediately after birth. The mean catecholamine concentration was 62.1 nmol/liter in the umbilical artery and 29.3 nmol/liter in the umbilical vein of newborn full term infants delivered uneventfully. This value is considerably higher than in resting adults. Similar levels of catecholamines were seen after elective cesarean sections, whereas considerably higher levels were found after breech deliveries. In the full term asphyxiated infants about a 4-fold increase of the catecholamine concentration was found in both the umbilical arterial and venous blood. The amine concentration level correlated inversely to the pH below 7.25 (10 log catecholamine concentration versus pH, r = -0.71). Preterm infants had, in general, lower amine levels than full term infants both after uneventful deliveries and after intrauterine asphyxia. The catecholamine levels were considerably increased in the newborn infants who showed some kind of abnormal fetal heart rate variation during the last hour before birth; in particular baseline changes were associated with high levels whereas only a moderate increase was seen after loss of beat-to-beat variation.     

Thinness at birth in a northern industrial town

OBJECTIVE: To determine whether babies in an area of Britain with unusually high perinatal mortality have different patterns of fetal growth to those born elsewhere in the country. DESIGN: Measurement of body size in newborn babies. SETTING: Burnley (perinatal mortality in 1988 15.9/1000 total births) and Salisbury (perinatal mortality 10.8/1000 total births), England. SUBJECTS: Subjects comprised 1544 babies born in Burnley, Pendle, and Rossendale Health District, and 1025 babies born in Salisbury Health District. MAIN OUTCOME MEASURES: Birthweight, length, head, arm and abdominal circumferences, and placental weight were determined. RESULTS: Compared with babies born in Salisbury, Burnley babies had lower mean birthweight (difference 116 g, 95% confidence interval (CI) 77,154), smaller head circumferences (difference 0.3 cm, 95% CI 0.2, 0.4), and were thinner as measured by arm circumference (difference 0.3 cm, 95% CI 0.3, 0.4), abdominal circumference (difference 0.5 cm, 95% CI 0.4, 0.6) and ponderal index (difference 0.8 kg/m3, 95% CI 0.6, 1.0). The ratio of placental weight to birthweight was higher in Burnley (difference 0.6%, 95% CI 0.4, 0.9). These differences were found in boys and girls and did not depend on differences in duration of gestation or on the different ethnic mix of the two districts. Mothers in Burnley were younger, shorter in stature, had had more children, were of lower social class, and more of them smoked during pregnancy than mothers in Salisbury. These differences did not explain the greater thinness of their babies. CONCLUSIONS: Babies born in Burnley, an area with high perinatal mortality, are thin. The reason is unknown. Poor maternal nutrition is suspected because Burnley babies have a higher ratio of placental weight to birthweight. The greater thinness at birth of Burnley babies could have long term consequences, including higher rates of cardiovascular disease.     

Endogenous digoxin-like immunoreactivity during pregnancy and at birth

A typhoid fever outbreak affecting 54 school students occurred in a Public School of Móstoles, Madrid. The date of onset was 11 June 1991 and the last detected case was 8 July 1991. Salmonella typhi was cultured from blood and/or stool samples corresponding to 54 patients and one food-handler. There were no secondary cases detected. Epidemiological investigation suggested a salad or a custard as the common source. Patients and the food-handler were treated with ampicillin/amoxicillin for up to three weeks. There were seven relapses that were also treated with the same antibiotics with success. None were found to be excreting the organisms when tested after four months. All the Salmonella typhi isolated strains were phagetype 34, biotype Xylose +, Tetrationate Reductase + and harboured a similar 22 Mdal plasmid, they were also susceptible to the antibiotics tested.     

The development of ketogenesis at birth in the rat

In the suckling newborn rat, blood ketone bodies begin to increase slowly 4h after birth and then rise sharply between 12 and 16h, whereas the major increase in plasma non-esterified fatty acids and liver carnitine occurs during the first 2h of life, parallel with the onset of suckling. In the starved newborn rat, which shows no increase in liver carnitine unless it is fed with a carnitine solution, the developmental pattern of the ketogenic capacity (tested by feeding a triacylglycerol emulsion, which increases plasma non-esterified fatty acids by 3-fold) is the same as in the suckling animal. This suggests that the increases in plasma non-esterified fatty acids and liver carnitine seen 2h after birth in the suckling animal are not the predominant factors inducing the switch-on of ketogenesis. Injection of butyrate to starved newborn pups resulted in a pattern of blood ketone bodies which was similar to that found after administration of triacylglycerols, but, at all time points studied, the hyperketonaemia was more pronounced with butyrate. It is suggested that, even if the entry of long-chain fatty acids into the mitochondria is a rate-limiting step, it is not the only factor controlling ketogenesis after birth in the rat. As in the adult rat, there is a reciprocal correlation between the liver glycogen content and the concentration of ketone bodies in the blood.     

Relation of hemoglobin measured at different times in pregnancy to preterm birth and low birth weight in Shanghai, China

This paper addresses two questions: 1) What is the relation of hemoglobin in the second gestational month to preterm birth and low birth weight? 2) How does the relation differ when hemoglobin in the fifth or eighth month or the lowest pregnancy hemoglobin are examined in place of first trimester values? These relations were examined prospectively in 829 women from Shanghai, China in 1991-1992. The population was nearly homogeneous by race, parity, antenatal care, and smoking. Rates of birth outcomes were compared between hemoglobin categories based on 10 g/liter groupings, with 110-119 g/liter as the reference group. Rates of low birth weight and preterm birth (but not small-for-gestational age) were related to early pregnancy hemoglobin concentration in a U-shaped manner. The relative risks (95% confidence intervals) for preterm birth in women by g/liter of hemoglobin were 2.52 (0.95-6.64) for > or = 130 g/liter, 1.11 (0.41-2.99) for 120-129 g/liter, 1.64 (0.77-3.47) for 100-109 g/liter, 2.63 (1.17-5.90) for 90-99 g/liter, and 3.73 (1.36-10.23) for 60-89 g/liter. Use of hemoglobin values in the fifth or eighth month attenuated the association with preterm birth. When lowest pregnancy hemoglobin values were used, the association of anemia with both outcomes was obscured, and risk of preterm birth at high hemoglobin values increased dramatically.     

Relation between birth weight at term and systolic blood pressure in adolescence

OBJECTIVE: To examine whether birth weight is related to systolic blood pressure during adolescence. DESIGN: Retrospective (comparative) cohort study. The observers who traced and studied the subjects were unaware of their case-control status. SUBJECTS: 330 subjects were born in Cardiff in 1975-7. Cases who were low birth weight at term (< 2500 g) were matched with controls of normal birth weight (3000-3800 g) at term. MAIN OUTCOME MEASURES: Systolic blood pressure measured by random zero sphygmomanometry in the subject's right arm with the subject supine, corrected for size and age. RESULTS: The mean age at examination was 15.7 years. The mean systolic blood pressure of the cases was 105.8 mm Hg and of the controls 107.5 mm Hg. The corrected difference (95% confidence interval) in systolic blood pressure between the cases and controls was 1 mm Hg (-3 to +1 mm Hg; two tailed probability 0.33). CONCLUSION: Systolic blood pressure in adolescents of low birth weight is not significantly different from that of adolescents of normal birth weights.     

Variation in response to growth factor stimuli in satellite cell populations

The effects of lifelong ethanol consumption and ageing on the morphology of locus coeruleus (LC) were studied in alcohol-preferring AA (Alko Alcohol) rats of both sexes. Ethanol (12% v/v) was the only available liquid for the ethanol-consuming rats from 3 months up to 24 months of age. Young (3-month-old) and old (24-month-old) control groups were included in the measurements. The LC morphometry was performed by an unbiased disector method. In the old control rats, the total neuron number, neuronal density and the volume of the LC proper did not differ from the young controls. In the ethanol-exposed rats, the total neuron number of the LC was decreased by 30% and the LC neuronal density by 22%, compared to the age-matched controls. No gender difference was found in the vulnerability of LC neurons to ethanol-induced degeneration. The results suggest a remarkable sensitivity of the LC neurons to the ethanol-induced degeneration in both male and female rats. The possible mechanisms and functional implications of this neuronal loss are discussed.     

Age of mother at last birth in two historical populations

This study uses sets of historical family reconstitutions from all of Quebec and from four villages of the Haut-Jura, France--first marriages of 2226 and 994 women, respectively--to investigate the physiological and social factors affecting age of mother at last birth before and during fertility transition. Age remained high throughout the period covered in Quebec, under 'natural' conditions, but showed a steady decline in the French material which extends to late 19th century generations practising family limitation. Age at marriage had no influence in Quebec; in France, however, women with the most surviving children at age 35 continued childbearing the latest. There was no link between biological ability to achieve a live birth, or in health status or aging rhythm, and age at last birth. Behaviour of mothers and daughters showed no relation. The variability in age at last birth thus appears to be random under natural conditions; with the onset of controls, social differences seem to influence not only the end of childbearing, but all aspects of behaviour governing final family size and child survival.     

Short-term memory and language outcomes after extreme prematurity at birth

The performance of 26 children (3;0-4;0 years) who were born before 32 weeks gestation was compared with the performance of 26 full-term children on a range of short-term memory and language measures. The measures tested vocabulary, expressive language, phonological short-term memory, and general nonverbal ability. Preterm children scored more poorly across the full range of measures. The mildly depressed performance of the preterm group on the short-term memory and language measures was attributable to the large deficits on these tests shown by a subgroup of approximately one third of preterm children identified as being "at risk" for persisting language difficulties using the Bus Story Test (Bishop & Edmundson, 1987). The findings indicate that preterm birth and associated hazards may constitute a significant risk factor for specific language impairment in a sizable minority of children.     

Risk factors for low birth weight and intrauterine growth retardation in Santiago, Chile

An epidemiologic case-control study to ascertain the determinants of low birthweight was carried out in Santiago, Chile, from January to December 1989. The cases were defined as livebirths < 2500 g. The controls were livebirths > or = 2500 g of birthweight. All cases and a random sample (1:1) of controls were selected among 8,254 singleton births occurring at the El Salvador Hospital in the Eastern area of Santiago. These deliveries represented 50% of institutional deliveries in the area. Home deliveries (2%) and private hospital deliveries were not included in the study. Information was obtained from hospital medical records by six trained medical students. Some information could not be obtained from the hospital medical records. Thus the second step in data collection was the tracking of all the selected subjects to their referring neighborhood health centers. For the analysis, the data were divided into 3 case (outcome) categories: 453 subjects were the total case group. From these, 153 were the IUGR case group and 300 were the LBW preterm case group. The general control group consisted of 605 normal birthweight infants. 565 were the IUGR control group and 40 were the preterm control group. A total of 25 risk factors showed a significant crude odds ratio for at least one of the groups. In the multivariate logistic regression analysis eight variables: No. of pregnancies, previous adverse outcomes, previous LBW, pregnancy maternal weight, No. of visits, month of first prenatal care visit, maternal smoking and intrahepatic cholestasis of pregnancy, were significantly associated with LBW after adjustment by confounding. Eight risk factors: IUGR in previous pregnancies, Previous adverse outcome, Maternal smoking, intrahepatic cholestasis, maternal pregnancy weight, maternal height, month first prenatal visit, No. of visit, were significant to IUGR. Only two variables: pregnancy weight, divorced mother, were significantly associated with low birth weight in the preterm group. The most relevant risk factors were included in stepwise logistic regression models carried out for the outcome LBW for the general group, term group and preterm group, in order to adjust by confounding. Adjusted odds ratios were then obtained. Prenatal care related factors and maternal adverse obstetric factors were at higher significance for LBW in the general and IUGR groups. Only nutritional factors were related to LBW in preterm group. Women who delivered a LBW or IUGR infant were more likely to have fewer pregnancies, a history of previous LBW, lower prepregnancy weight and lower gestational weight gain. ICP was associated with an elevated risk of LBW that was independent of gestational age.     

Racial and ethnic differences in determinants of intrauterine growth retardation and other compromised birth outcomes

OBJECTIVES: This study examined the extent of variation by race/ethnicity in the prevalence of adverse birth outcomes, whether differentials persisted after other risk factors were controlled for, and whether the direction and magnitude of relationships differed by type of outcome. METHODS: A revised system of measurement was used to estimate multinomial logistic models in a large, nationally representative US data set. RESULTS: Considerable racial/ethnic variation was found across birth outcome categories; differences persisted in the adjusted parameter estimates; and the effects of other risk factors on birth outcomes were similar as to direction, but varied somewhat in magnitude. The odds of compromised birth outcomes were much higher among African Americans than among Mexican Americans and non-Hispanic Whites. CONCLUSIONS: In addition to persistent racial inequality, we found strong adverse effects of both inadequate and "adequate-plus" prenatal care and smoking. Risk of intrauterine growth retardation was higher in the absence of medical insurance, and risk of all adverse birth outcomes was lower among mothers participating in the Special Supplemental Food Program for Women, Infants, and Children.