Prenatally detected double trisomy: Klinefelter and Down syndrome

Double trisomies are a rare occurrence. We report the first case of a Down and Klinefelter's syndrome (48,XXY,+21) in a fetus that was prenatally diagnosed during the 15th week of pregnancy. Even though the nasal bone was present, and the color-Doppler study of the ductus venosus and the nuchal thickness were normal, the maternal serum test results indicated an increased risk of Down syndrome and consequentially a genetic amniocentesis was performed. A 48,XXY,+21 karyotype was observed and the patient decided to terminate the pregnancy. In this case, we did not find the typical ultrasound (US) signs that would have led us to the chromosomopathy; furthermore, we emphasize the advantages of using biochemical screening which, in our case, were crucial in arriving at the correct diagnosis. Copyright © 2006 John Wiley & Sons, Ltd.     

An attempt to recover economic losses from decadal changes in two lagoon systems of Sri Lanka through a newly patented mangrove product

Kahandamodara and Kalametiya are two estuarine lagoons located within about 12 km distance along the Southern coast of Sri Lanka. According to a socio-economic survey, both lagoons have been moderately to high saline water bodies and the latter was an important center of prawn fishery until the late 1960s. Two irrigation projects upstream (Udawalawe irrigation scheme and Muruthawela Wewa), which came into operation in 1967 and 1968 respectively, increased freshwater inflows to these two lagoons and altered flora, fauna, and water quality, with a decline of lagoon fishery as a result. At the same time, the increase in freshwater favorised the Mangrove Apple Sonneratia caseolaris to expand spontaneously. Following many hectares of vegetation increase of this species, our study focused on recovering the economic loss of fisheries decline by using new ethnobotanic information on this species. We found that the pulp of the fruit of the Mangrove Apple is tasty and can be used to prepare a fruit drink. However, it has not been commercialised, or even practiced widely at homes, due to the fact that numerous small seeds in the fruit release certain phenolic compounds when damaged, giving a bad colour and an astringent taste to the pulp. We developed a method to get the fruit pulp from the Mangrove Apple minimising the addition of phenolic compounds. This fruit pulp was then used to produce ice cream and fruit drinks, and the whole procedure has been patented in Sri Lanka for the favour of the local people. Apparently this is a novel mangrove product reported for the first time in mangrove ethnobotany. In addition, analysis of the fruit pulp of the S. caseolaris for nutritional composition revealed that it is very rich in phosphorus and dietary fiber, indicating that these new products may have an even higher potential as a supplementary food. Its use as a health food and as a commercialised eco-product is expected to bring new gains in spite of the former ecosystem and fishery decrease. It is however not known to which extent these novel ethnobiological/socio-economical uses outbalance functions lost by ecosystem degradation.     

Neurotoxicology of ortho-substituted polychlorinated biphenyls

Ortho-substituted, non-planar PCBs reduce dopamine content in both nonhuman primate brain and pheochromocytoma (PC12) cells. Planar, dioxin-like, congeners have no effect on dopamine content in PC12 cells. Additional in-vitro results indicate that dopamine reduction by PCBs is due to inhibition of tyrosine hydroxylase activity.     

The Impact of Brown-Headed Cowbird Parasitism on Populations of the White-Crowned Sparrow

Brown-headed Cowbirds, Molothrus ater , are brood parasites on many species of North American Passerines. Cowbird parasitism is frequently cited as a contributing factor in the decline of United States passerine populations, based on three lines of evidence. First, range expansion and population increases by Cowbirds in this century are dramatic and well documented. Second, increasing rates of parasitism have been discovered in a variety of host species populations. Finally, direct negative effects of parasitism on certain vulnerable species notably Kirtland's Warbler, Dendroica kirtlandii , have been demonstrated. It remains unproven, however, that Cowbirds have significant negative effects on more abundant and widely-distributed hosts.
We report here on the impact of Cowbird parasitism on populations of Nuttall's White-crowned Sparrow, Zonotrichia leucophrys nuttalli , in the San Francisco Bay Area. This widespread songbird is now subject to a 40–50% rate of parasitism in San Francisco, an increase from 5% only 15 years ago. Using known mortality and fecundity values, we calculate that this population of White-crowns cannot maintain its numbers when the parasitism rate exceeds approximately 20%. Present levels of parasitism thus appear to threaten the longevity survival of this adaptable Songbird in the San Francisco Bay Area.     

Die Strahlengefahr — realistisch gesehen

It is evident that ionizing radiation at high doses is able to damage living organisms and may induce cancer and leukemia in man. At low doses, however, biopositive effects appear possible too, for which examples are given. The mechanism of such effects can be explained as a general stimulation of the natural immune system. In conclusion, radiation at low doses is thus not as dangerous as often assumed but is rather essential for life and the maintenance of health.     

Cytogenetic analysis of trophoblasts by comparative genomic hybridization in embryo-fetal development anomalies

Cytogenetic studies of spontaneous abortions or intrauterine fetal death depend on conventional tissue culturing and karyotyping. This technique has limitations such as culture failure and selective growth of maternal cells. Fluorescent in situ hybridization (FISH) using specific probes permits diagnosis of aneuploidies but is limited to one or a few chromosomal regions. Comparative genomic hybridization (CGH) provides an overview of chromosomal gains and losses in a single hybridization directly from DNA samples. In a prospective study, we analyzed by CGH trophoblast cells from 21 fetuses in cases of spontaneous abortions, intrauterine fetal death or polymalformed syndrome. Six numerical chromosomal abnormalities including one trisomy 7, one trisomy 10, three trisomies 18, one trisomy 21 and one monosomy X have been correctly identified by CGH. One structural abnormality of the long arm of chromosome 1 has been characterized by CGH. One triploidy and two balanced pericentromeric inversions of chromosome 9 have not been identified by CGH. Sexual chromosomal constitutions were concordant by both classical cytogenetic technique and CGH. Contribution of trophoblast analysis by CGH in embryo-fetal development anomalies is discussed. Copyright © 2001 John Wiley & Sons, Ltd.     

Different mechanisms of extinction of conditioned taste aversion are dependent on time intervals of extinction following conditioning

After extinction, the reappearance of a conditioned response induced by an unconditioned stimulus which is weaker than that used during the conditioning training indicates that the extinction procedure does not eliminate the original conditioned memory. Recent studies on fear conditioning have shown that rats exhibited little or no recovery of conditioned responding if the time interval between fear acquisition and extinction was short, suggesting that the extinction process may erase the original conditioning trace in this situation. In the present study, a saving experiment was conducted in rats to investigate whether an aversive response could be recovered following extinction training with different time intervals after acquisition of conditioned taste aversion (CTA). Male Long–Evans rats developed CTA by associating a 0.2% sucrose solution with malaise induced by intraperitoneal injection of 4 ml/kg 0.15 M LiCl and were subjected to extinction training with an interval of 5 h (5H group) or 24 h (24H group) after acquisition of CTA. Rats in the 5H group, but not in the 24H group, exhibited no aversive responding to the sucrose solution followed by the injection of a lower dose of LiCl (1 ml/kg). These findings indicate that the extinction procedure administered at different time points following the acquisition of CTA affects recovery of extinguished aversive memory and suggest that an unlearning process may be involved in the mechanisms of CTA extinction with short intervals between acquisition and extinction.     

Spillover of functionally important organisms between managed and natural habitats

Land-use intensification has led to a landscape mosaic that juxtaposes human-managed and natural areas. In such human-dominated and heterogeneous landscapes, spillover across habitat types, especially in systems that differ in resource availability, may be an important ecological process structuring communities. While there is much evidence for spillover from natural habitats to managed areas, little attention has been given to flow in the opposite direction. This paper synthesizes studies published to date from five functionally important trophic groups, herbivores, pathogens, pollinators, predators, and seed dispersers, and discusses evidence for spillover from managed to natural systems in all five groups. For each of the five focal groups, studies in the natural to managed direction are common, often with multiple review articles on each subject which document dozens of examples. In contrast, the number of studies which examine movement in the managed to natural direction is generally less than five studies per trophic group. These findings suggest that spillover in the managed to natural direction has been largely underestimated. As habitat modification continues, resulting in increasingly fragmented landscapes, the likelihood and size of any spillover effect will only increase.