It has long been considered that a severe coagulation deficiency in premature newborns could be a major contributing factor in the occurrence of intraventricular hemorrhage (IVH). High-grade IVH has also been shown to coincide with severe derangement of coagulation in extremely low birth weight infants. This review focuses on the relevance of the physiologically developing immature hemostatic system to IVH, and the potential benefit of agents affecting hemostasis for IVH therapy or prevention in preterm infants. The findings of small, open-label interventional studies on the effect of ethamsylate, vitamin K, fresh frozen plasma, recombinant activated factor VII, and prothrombin complex concentrate on the premature coagulation system will be reviewed.
Human platelets carry membrane glycoproteins that control platelet aggregation and activation. A number of clinical studies have suggested that certain polymorphisms of genes encoding these proteins increase the risk for cardiovascular disease. The frequency of gene polymorphisms for the four most common platelet glycoproteins (HPA 1, 2, 3 and 5) was examined and correlated with the primary cause of end-stage renal disease (ESRD) in Greek patients on HD. Fifty-five (55) patients on chronic maintenance haemodialysis (HD) (22 female, 33 male), aged from 23- to 87-years-old, (mean age 66 years), being on dialysis for 53 +/- 34 months, were included in the study. HPA-1, -2, -3, and -5 genotyping was performed using polymerase chain reaction (PCR) amplification with sequence-specific primers (PCR-SSP). Calculated relative frequencies of the alleles were as follows: HPA-1a/b 0.81/0.19, HPA-2a/b 0.92/0.08, HPA-3a/b 0.62/0.38 and HPA-5a/b 0.93/0.07. There was a statistically significant association between the HPA-1b allele and hypertension as the primary cause of ESRD (65% of patients with hypertension vs 23% of all other patients carried the HPA-1b allele, p=0.02, Fishers exact test). The results suggest that Greek carriers of the HPA-1b allele with hypertension may be at increased risk for developing end-stage renal disease.
An extensive four-year research program has been carried out to explore and acquire knowledge about the fundamental agricultural practices and processes affecting the mobility and bioavailability of pesticides in soils under semi-arid Mediterranean conditions. Pesticide leaching was studied under field conditions at five different depths using suction cups. Monitoring of metolachlor, alachlor, atrazine, deethylatrazine (DEA), deisopropylatrazine (DIA), and bromide ions in soil water, as well as dye patterns made apparent the significant role of preferential flow to the mobility of the studied compounds. Irrespective to their adsorption capacities and degradation rates, atrazine, metolachlor and bromide ions were simultaneously detected to 160 cm depth. Following 40 mm irrigation, just after their application, both alachlor and atrazine were leached to 160 cm depth within 18 h, giving maximum concentrations of 211 and 199 ?g L(-1), respectively. Metolachlor was also detected in all depth when its application was followed by a rainfall event (50 mm) two weeks after its application. The greatest concentrations of atrazine, alachlor and metolachlor in soil water were 1795, 1166 and 845 ?g L(-1), respectively. The greatest concentrations of atrazines degradation products (both DEA and DIA) appeared later in the season compared to the parent compound. Metolachlor exhibited the greatest persistence with concentrations up to 10 ?g L(-1) appearing in soil water 18 months after its application. Brilliant blue application followed by 40 mm irrigation clearly depict multi-branching network of preferential flow paths allowing the fast flow of the dye down to 150 cm within 24 h. This network was created by soil cracks caused by shrinking of dry soils, earthworms and plant roots. Chromatographic flow of the stained soil solution was evident only in the upper 10-15 cm of soil.
A five-year groundwater monitoring program undertaken in Evros (north-east Greece), showed a diversification in the levels of pesticide residues detected in adjacent transboundary aquifers. During the first two years 37 wells, including irrigation, drinking water and artesian wells were monitored while the next three years the survey was focused on the 11 most contaminated wells. The presence of pesticide residues was also monitored in the phreatic horizon (shallow groundwater) of four experimental boreholes drilled in the respective margins of four fields. Among the compounds found alachlor, metolachlor, atrazine, desethylatrazine (DEA), desisopropylatrazine (DIA) and caffeine were constantly detected. Pesticide concentrations were much lower (up to 1.54 ?g/L) in the water of the monitored drinking water wells (deep groundwater aquifers) compared to those found in the phreatic horizon (experimental boreholes) of the respective areas (up to 5.20 ?g/L). DEA to atrazine concentration ratios (DAR) determined for the phreatic horizon of the three boreholes and respective wells were lower than 1, indicating that preferential flow was the cause of the fast downward movement of atrazine to the phreatic horizon. In contrast the DAR for the fourth borehole and the adjacent well were greater than 1 indicating the absence of preferential flow of atrazine. Catabolic processes of the soil converted atrazine to DEA which is more mobile than atrazine itself through chromatographic (darcian) flow. This differential behavior of pesticides in adjacent aquifers (3 km) was further investigated by determining the apparent age of water in the two wells. The apparent age of the water present in the first aquifer was 21.7 years whereas the apparent age of that in the second aquifer was approximately 1.2 years. The faster replenishing rate of the latter is an indication that this aquifer is very vulnerable to contamination with pollutants present in the infiltrated soil water.
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