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El mundo médico ha negado durante mucho tiempo la posibilidad de que el feto pudiese sentir dolor. Posteriormente, experimentos realizados en recién nacidos muy prematuros han mostrado que las estructuras necesarias para la percepción del dolor están presentes desde la mitad del segundo trimestre del embarazo. A partir de estos resultados, la necesidad de tratar este dolor se ha hecho evidente. Paralelamente, la mejora de las técnicas de imagen prenatal y el desarrollo de la medicina fetal han permitido manejar y tratar in utero algunas enfermedades fetales. Las técnicas de anestesia y analgesia permiten no solamente manejar el dolor de la madre durante estas intervenciones, sino también tratar el dolor del feto y disminuir, si es necesario, los movimientos fetales durante estos procedimientos.

Abstract: Pollution effects on fish populations were estimated with a simulation model, using Leslie matrices. Results from changing only first-year survival rate (So) have already been published (Schaaf et al. 1987). This paper explores the effects of perturbing both So and the adult survival rate (Si) for 12 spatial-temporal stocks. Most stocks examined are more sensitive to permanent change in Si than to changes in So. The relative importance of these two rates in determining the population growth rate (λ) depends upon the age distribution of the expected lifetime egg production of age i females (Vi). In turn, the vector Vi, as measured by its mean and standard deviation, is shown to vary among geographic or temporal stocks of a single species. Hence, we quantify the impact on population size of destroying a fixed percentage of habitat, relative to where and when it occurs (i.e., relative impact on Si and So). For example, destroying 1% of the Atlantic menhaden habitat would reduce λ by 0.8% and the population by 8.0% in 10 yr, if the impact affected only adults (e.g., offshore in winter). If the 1% habitat destruction all occurred in the estuaries, affecting juveniles as well, λ would be reduced by almost 5%, and in 10 yr drive the population down to 58% of its former equilibrium. We show that knowledge of the mean and variance of the age distribution of Vi permits prediction of relative sensitivity among species to pollution. Within species, this knowledge of Vi permits comparison of the effects of impacting different life stages and at different times and places.

Abstract: We have developed a simulation model to estimate pollution effects on economically important estuarine-dependent fish populations. Traditionally, pollution studies have focused upon impacts on individual organisms; however, wise management of marine resources depends upon an understanding of dynamics at the population level. As a required first step toward conducting relevant pollution studies, we have compiled available life history data on eight species (14 spatial-temporal stocks), concentrating on age-specific rates of growth, survival, and fecundity. Leslie matrix models of species population dynamics were used to predict pollutant impacts—mediate through changes in 1st-year survival. On average, and without compensation, these modelled stocks respond to a one-time-50% reduction in first-year survival by taking ten years to equilibrate at 88% of their preimpact abundance. Our synthesis of the data included a search for derived (standardized) population parameters to evaluate differences in susceptibility among and within fish populations to pollutant stresses. We demonstrated that knowledge of a species’ age-specific fecundity pattern provides additional predictive power of its response to pollution perturbation.

(Abstracted from Ultrasound Obstet Gynecol2018;52:715–721)Nuchal translucency (NT) is a collection of fluid at the back of the fetal neck; its thickness can be measured by ultrasound between 10 and 13 + 6 weeks of gestation. An increased thickness, often defined as an NT of greater than the 99th centile, which corresponds approximately to a threshold of 3.5 mm, is associated with a risk of chromosomal abnormalities, as well as genetic syndromes such as Noonan and Smith-Lemli-Opitz syndrome, and major structural birth defects.

Little information was available on metabolism by animals of Mn in chemical forms existing in plants. Incorporation of 54Mn into plants is a practical way to facilitate such studies; however, before this could be done, studies were required on factors affecting 54Mn uptake by plants. Accordingly, the influence of dose levels and dose‐date and harvest‐date on 54Mn uptake by four plant species were studied. Also, the absorption by rats of the 54Mn incorporated into plants was studied. Increasing 54Mn dose level from 0.86 to 8.6 and 86 µCi decreased uptake. Applying the dose 19 days after planting increased 54Mn uptake, as compared to applying it 12 days after. Uptake by soybeans [Glycine max(L.) Merrill] was higher than by corn (Zea maysL.), millet (Panicumsp.), or sorghum [Sorghum bicolor(L.) Moench] ✕ sudan (Sorghum vulgare sudanense), especially at the lowest dose level. Livers of weanling male rats fed 54Mnforage contained only one‐third as much 54Mn as those of rats given 54MnCl2. Similar effects were evident in kidneys and duodenum. Thus, Mn in forage was much less available to rats than Mn as the chloride illustrating the importance of chemical form of Mn on its metabolism and value to animals.

FERRITIN is an iron-storage protein found in the cytoplasm of a wide variety of plant and animal cells1,2. Structurally, the molecule comprises a hollow protein shell, apoferritin, composed of 20 or 24 subunits, within which variable amounts of inorganic iron may be sequestered. These subunits may not be chemically identical since multiple molecular forms of differing charge, isoferritins, have been found in several organs by electrophoresis3,4or electrofocusing5,6. Although the structural relationship of the isoferritins is unclear, these findings raise the possibility that the charge differences may represent primary structures coded by different genes. In addition to the isoferritins found in normal cells, an “abnormal” ferritin has also been found in malignant cell lines7and in livers of tumour bearing animals8,9. As part of our investigations into tumour specific and embryonic antigens, we have examined the isoferritin profile in human hepatoma and compared it to that found in normal adult and foetal liver. Here we supply evidence for a unique isoferritin species in human hepatoma that is not present in normal adult liver. This tumour-specific isoferritin may correspond to a similar isoferritin found in foetal liver in early gestation.