Homogenous catalyzed ozonation of simazine. Effect of Mn(II) and Fe(II).

Simazine, [2-chloro, 4,6-bis(ethylamino)-1,3,5-s-triazine], a common herbicide typically found in surface and ground water was ozonised by using catalytic amounts of Mn(II) and Fe(II). An optimum value for metal concentration was found in the process. Some inhibition of the simazine degradation rate was observed when these metals were added above the optimum concentration. The pH of the reaction media played a significant role in the simazine oxidation rate. Thus, an increase in simazine conversion was observed when the pH was raised from 5 to 9. However, the catalytic effect of added manganese was negligible at the highest pH used in this study (pH 9). The beneficial influence of Fe(II) was also observed when utilising the combination of ozone and hydrogen peroxide. Contrarily, Mn(II) presented a negative influence on simazine conversion when using this oxidation technology.     

Expansion of Calamagrostis villosa in sub-alpine Nardus stricta grassland: Cessation of cutting management or high nitrogen deposition?

Calamagrostis villosa has recently expanded in Nardus stricta-dominated sub-alpine grassland of the Giant Mountains (Krkono?e/Karkonosze, the Czech Republic). To investigate whether this expansion has been promoted by high nitrogen deposition or by the cessation of agricultural management, grassland plots dominated by C. villosa were manipulated with four treatments: control (Con), fertilised (Fer), cut (Cut) and cut–fertilised (Cut–Fer). NH₄NO₃ was used at the rate of 30 kg N ha^?1 and fertilisation and cutting were performed once a year after data collection in late July between 2000 and 2006.Plant species composition (analysed by RDA) was significantly influenced by cutting but not by fertilisation. Cutting reduced the cover, biomass, sward height and tiller density of C. villosa. Seedlings of N. stricta and panicles of C. villosa were recorded only in plots with cutting management.To investigate the effect of treatments on the spread of C. villosa, grassland sods dominated by N. stricta were transplanted into the experimental plots. Six years later, the density and cover of C. villosa spreading into the N. stricta sods were highest in Fer treatment.C. villosa was recognised as a defoliation-sensitive species and this sensitivity cannot be overcome by an increase in N supply. Recent expansion of C. villosa in the sub-alpine grassland can by explained by a long-term succession after the cessation of agricultural management and an increase in the N availability in recent decades.     

Prenatal diagnosis of congenital Chagas' disease (American trypanosomiasis)

The prenatal diagnosis of congenital transmission of Chagas' disease in a pregnant woman with the indeterminate form of the disease is reported. Sonography revealed fetal hydrops at 31 weeks' gestation. Anti-Trypanosoma cruzi IgM and IgG antibodies were negative in the fetal blood sampled by cordocentesis, but T. cruzi trypomastigotes were found in its buffy coat. Owing to anemia, in utero exchange transfusion was undertaken, but fetal demise ensued. Labor was induced and a stillborn infant weighing 2030 g was delivered. The pathological examination revealed placentitis and meningoencephalitis, myocarditis and splenitis in the stillborn fetus. Amastigotes were found in the myocardium, brain and placenta. Copyright © 2004 John Wiley & Sons, Ltd.     

Pilot study for the neonatal screening of fragile X syndrome

An Erratum has been published for this article in Prenatal Diagnosis 23 (9), 2003, 771. Fragile X syndrome (SFX) is the commonest form of inherited mental retardation. Due to the highly variable phenotype clinical diagnosis is complicated. In nearly all cases, the disorder is caused by expansion of a CGG-repeat in the 5′-untranslated region of the FMR1 (fragile X mental retardation-1) gene. We have evaluated the feasibility, efficiency and costs of two methodologies in order to develop a simple test to screen large populations: PCR and fragile X mental retardation-1 protein (FMRP) immunodetection. We studied 100 newborn males using PCR and immunodetection (26.91 Euro). All but one amplified the CGG repeat of the FMR1 gene within the normal size range. The sample that failed to amplify showed only 28% of FMRP expression by immunodetection study; both results indicated an affected male. A further 100 males were studied only by polymerase chain reaction (PCR) (7.8 Euro); all of them amplified within the normal size range. Both methodologies, PCR and immunodetection, are feasible for screening large populations, PCR being the most suitable, economical and less time-consuming. However, it is advisable to keep slides for immunodetection when PCR fails or the external control shows no amplification. Early detection of SFX-affected individuals would represent a great benefit for their maximum social integration, due to appropriate treatment and early stimulation and would permit a cascade screening in their pedigree. Copyright © 2002 John Wiley & Sons, Ltd.     

Costs of the Wastewater Standard in Pig Production in Mexico

The objective of this article is to address the environmental costs of pig farms in the La Piedad region Mexico, through an analysis of the standard on wastewater discharges to national water bodies. Field work was carried out from April to September 1999; a survey was conducted on 23 farms and samples of wastewater were taken on 11 farms. Pig production is the third most important system in Mexican livestock production. Heterogeneity in production systems, dependence on imported inputs (genetics and feed grains), and weak internalization of environmental costs are the main characteristics of pig production in Mexico. With no specific environmental regulations on intensive livestock activities at the municipal or state levels, Mexican Official Standard 001 on wastewater discharges is the only environmental obligation that pig farms must meet. Standard 001 on wastewater contains the maximum permissible limits for 20 contaminant parameters, and is based on a cost-benefit analysis that points to secondary treatment for the regulation’s economic viability. Investment in treatment systems and the fees that pig producers must pay when they fail to comply with the limits stipulated in the regulation, are estimated assessed as an approach to environmental costs. In order to remain within the limits in the standard, pig farms must invest in tertiary treatment, and that makes meeting the standard unaffordable for this sector.     

Intrauterine left chamber myocardial infarction of the heart and hydrops fetalis in the recipient fetus due to twin-to-twin transfusion syndrome

A rare complication of twin-to-twin transfusion syndrome (TTTS) is described: myocardial infarction of the recipient fetus. Myocardial infarction and hydrops are considered to be consequences of hypertension in the recipient. No other organs were affected. Pathological signs of intrauterine hypertension were estimated by the thickness of vessel walls and signs of hypertrophied myocardial cells. In the heart of the recipient fetus there was a chronic myocardial infarction near the apex cordis on the anterior wall with an aneurysm 4×5 mm in diameter. Diagnosis was based on light microscopic examination. The poor myocardial systolic function resulted in hydrops. Since the mother was administered β sympathomimetics in therapeutic doses the contribution of the drug to the myocardial infarction is uncertain, but we would like to suggest this as a possible adverse effect in TTTS. The present case is the first reported myocardial infarction in connection with the syndrome. Copyright © 2002 John Wiley & Sons, Ltd.     

Pulmonary stenosis and reactive right ventricular hypertrophy in the recipient fetus as a consequence of twin-to-twin transfusion

The present study describes an association between adverse outcome in the twin-to-twin transfusion syndrome (TTTS) and pulmonary stenosis or reactive right ventricular hypertrophy. Six discordant monozygotic twin pregnancies with TTTS are described. Ventricular hypertrophy and atrioventricular valvular regurgitation occurred in all the recipient twins with pulmonary valvular stenosis in three cases and infundibular stenosis in one case. The recipient twin in one pair and both twins in another pregnancy died as a consequence of immaturity but the remaining twins all survived. Surgical intervention was required in one baby for valvular pulmonary stenosis. Our observations suggest that elevated blood pressure in the transfusion recipient may play an important role in pathogenesis. We hypothesise that both pulmonary stenosis and right chamber hypertrophy are secondary to hemodynamic changes. Although we have found valvular pulmonary stenosis in three recipients and infundibular stenosis in only one, this (obstruction to outflow) could be due to right chamber hypertrophy. Copyright © 2001 John Wiley & Sons, Ltd.     

Trisomy 2 due to a 3:1 segregation in an abortion studied by QF-PCR and CGH

Balanced reciprocal translocation is one of the known causes of recurrent spontaneous abortions. Cytogenetic studies of unbalanced miscarriages are difficult due to the growth failure of early loss and usually macerated abortions. We present a molecular study of an abortion in which the father carries a balanced reciprocal translocation t(2;17)(q32.1;q24.3) using QF-PCR and CGH techniques. DNA analysis showed the presence of a trisomy 2 due to a 3:1 interchange segregation. Recombinant events could also be investigated by comparing DNA samples from the family. We propose QF-PCR in addition to CGH as an efficient diagnostic method to improve our knowledge of unbalanced offspring in balanced translocation carriers. Copyright © 2005 John Wiley & Sons, Ltd.