4 resultados para Newborn

em University of Connecticut - USA


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Cattle are the species used most frequently for the development of assisted reproductive technologies, such as nuclear transfer. Cattle cloning can be performed by a large number of laboratories around the world, and the efficiency of nuclear transfer in cattle is the highest among all species in which successful cloning has been achieved. However, an understanding of the expression of imprinted genes in this important species is lacking. In the present study, real time reverse transcription polymerase chain reaction (RT-PCR) was utilized to quantify the expression of the bovine Igf2, Igf2r, and H19 genes in eight major organs (brain, bladder, heart, kidney, liver, lung, spleen, and thymus) of somatic cell cloned calves that died shortly after birth, in three tissues (skin, muscle, and liver) of healthy clones that survived to adulthood, and in corresponding tissues of control animals from natural reproduction. We found that, deceased bovine cloned calves exhibited abnormal expression of all three genes studied in various organs. Large variations in the expression levels of imprinted genes were also seen among these clones, which were produced from the same genetic donor. In surviving adult clones, however, the expression of these imprinted genes was largely normal, except for the expression of the Igf2 gene in muscle, which was highly variable. Our data showed disruptions of expression of imprinted genes in bovine clones, which is possibly due to incomplete reprogramming of donor cell nuclei during nuclear transfer, and these abnormalities may be associated with the high neonatal mortality in cloned animals; clones that survived to adulthood, however, are not only physically healthy but also relatively normal at the molecular level of those three imprinted genes.

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BACKGROUND: There are differences in the literature regarding outcomes of premature small-for-gestational-age (SGA) and appropriate-for gestational-age (AGA) infants, possibly due to failure to take into account gestational age at birth. OBJECTIVE: To compare mortality and respiratory morbidity of SGA and AGA premature newborn infants. DESIGN/METHODS: A retrospective study was done of the 2,487 infants born without congenital anomalies at RESULTS: Controlling for GA, premature SGA infants were at a higher risk for mortality (Odds ratio 3.1, P = 0.001) and at lower risk of respiratory distress syndrome (OR = 0.71, p = 0.02) than AGA infants. However multivariate logistic regression modeling found that the odds of having respiratory distress syndrome (RDS) varied between SGA and AGA infants by GA. There was no change in RDS risk in SGA infants at GA 32 wk (OR = 0.41, 95% CI 0.27 - 0.63; p < 0.01). After controlling for GA, SGA infants were observed to be at a significantly higher risk for developing chronic lung disease as compared to AGA infants (OR = 2.2, 95% CI = 1.2 - 3.9, P = 0.01). There was no significant difference between SGA and AGA infants in total days on ventilator. Among infants who survived, mean length of hospital stay was significantly higher in SGA infants born between 26-36 wks GA than AGA infants. CONCLUSIONS: Premature SGA infants have significantly higher mortality, significantly higher risk of developing chronic lung disease and longer hospital stay as compared to premature AGA infants. Even the reduced risk of RDS in infants born at >/=32 wk GA, (conferred possibly by intra-uterine stress leading to accelerated lung maturation) appears to be of transient effect and is counterbalanced by adverse effects of poor intrauterine growth on long term pulmonary outcomes such as chronic lung disease.

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Sex differences in seasonal timing include differences in hatch- or birth-date distribution and differences in the timing of migration or maturation such as protandrous arrival timing (PAT), which is early male arrival at breeding sites. I describe a novel form of protandrous arrival timing, as a sex difference in birth-date distribution in a live-bearing fish (Dwarf Perch, Micrometrus minimus). In this species, birth coincides with arrival at breeding sites because newborn males are sexually active. A series of samples of pregnant females and young of year was collected in Tomales Bay, CA. I analyzed the daily age record in otoliths to estimate the conception date of broods and the age that young-of-year individuals were born. Males were born at a younger age than females, as indicated by the daily age record and also by the predominance of females in broods from which some young had already been born, which was a common occurrence in pregnant females with older embryos. Sex ratio of broods varied with conception date such that early-season broods were predominantly male, possibly as a result of temperature-dependent sex determination. The combined effects of the sex difference in age at birth and seasonal shift in sex ratio were to shift the mean birth date of males relative to females by five days. The most likely ultimate explanation for PAT in the Dwarf Perch is that it arises from exploitation (scramble) competition for mating opportunities among recently-born young-of-year males.

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The purpose of this study was to describe predictors of level of grief and physical symptoms in mothers during the year after a newborn death. This was undertaken to fmd better ways to help these mothers during this crisis. Following appropriate approvals, volunteer subjects were contacted through hospitals, the Internet, and a health department. Of the 75 who responded, 77% were White and married, 64% were Christian. 51 % had other living children, 72% had had no prior pregnancy losses, 87% had support with decision-making about newborn care, and their mean age was 30 yrs. Once subjects had agreed to take Par4 the survey and consent form were sent to them. Study outcome variables were: Total scores on the Perinatal Grief Scale, Short Version (level of grief; T oedter, Lasker, & Alhadeff. 1988) and Sickness Impact Profile 68 (level of physical symptoms; de Bruin, Buys, de Witte, & Diederiks, 1994). Predictor variables were total scores on the Personal Resources Questionnaire 85, Part U (perceived support; Brandt & Weinert, 1981); Relationship Satisfaction Questionnaire (relationship satisfaction; Olson & McCubbin, 1983); Emotion-Focused. Problem-Focused, and Mixed Coping Subscales (emotion-focused, problem-focused, and mixed coping; Lazarus & Folkman, 1988); interval since death, ethnicity, religion, socioeconomic status, gestational age, and presence of living children. Coefficient alphas for scales were all over .75. In two stepwise-hierarchical multiple regressions, perceived support and emotion- focused coping combined to predict 43% of the variance in level of grief, and level of grief alone predicted 50% of the variance in level of physical symptoms. In written comments, mothers said they valued their role in decision-making about newborn care even with death as the result. and felt supported in that process. Findings may be used to design intervention programs to help bereaved mothers following a newborn death. Specifically, programs can help increase perceived support for bereaved mothers, and teach new ways of coping. Both strategies may result in lower levels of grief and physical symptoms in this group of bereaved mothers.