Colloidal mercury (Hg) distribution in soil samples by sedimentation field-flow fractionation coupled to mercury cold vapour generation atomic absorption spectroscopy.

Diverse analytical techniques are available to determine the particle size distribution of potentially toxic elements in matrices of environmental interest such as soil, sediments, freshwater and groundwater. However, a single technique is often not exhaustive enough to determine both particle size distribution and element concentration. In the present work, the investigation of mercury in soil samples collected from a polluted industrial site was performed by using a new analytical approach which makes use of sedimentation field-flow fractionation (SdFFF) coupled to cold vapour generation electrothermal atomic absorption spectroscopy (CV-ETAAS). The Hg concentration in the SdFFF fractions revealed a broad distribution from about 0.1 to 1 µm, roughly following the particle size distributions, presenting a maximum at about 400-700 nm in diameter. A correlation between the concentration of Hg in the colloidal fraction and organic matter (O.M.) content in the soil samples was also found. However, this correlation is less likely to be related to Hg sorption to soil O.M. but rather to the presence of colloidal mercuric sulfide particles whose size is probably controlled by the occurrence of dissolved O.M. The presence of O.M. could have prevented the aggregation of smaller particles, leading to an accumulation of mercuric sulfides in the colloidal fraction. In this respect, particle size distribution of soil samples can help to understand the role played by colloidal particles in mobilising mercury (also as insoluble compounds) and provide a significant contribution in determining the environmental impact of this toxic element.

Bidialysis: a new technique.

An increase in solute removal, a shorter dialysis session, the patient's well being and the reduction of global costs are the principal aims of the new hemodialysis methods. The simultaneous use of two hemodialyzers in hemodialysis has been experimented by other researchers. Our technique involves the use of two cuprophan hemodialyzers in sequence (double filter system: DFS), each one connected separately to fresh dialysate. Fifteen symptomatic large patients were treated with DFS and the results were compared to conventional hemodialysis (CHD). After the first hemodialyzer, modification of pH and electrolytes occurred in the plasma composition. In the second hemodialyzer, urea depuration occurred without further significant changes in hydroelectrolytic or acid-basic plasma patterns. The Kt/V increased from 1.10 to 1.29 (18%). The authors conclude that in DFS there was an advantage in urea clearance, osmolarity stability and reduction of side effects.

[Cardiac troponin I in chronic hemodialysis. Comparison of methods and results after 3 months]. / Troponina I cardiaca negli emodializzati cronici. Metodi a confronto e risultati a tre mesi.

The laboratory and instrumental markers today in use for the determination of myocardial damage present limitations in dialysis patients due to interference patterns that tend to reduce prognostic evaluation. The aim of this study is to evaluate whether troponin I (cTnI), a recently established marker of myocardial damage, can help to identify, in asymptomatic patients too, minor ischemic lesions that could screen this patient population for future acute cardiac events. In our study of 103 patients undergoing chronic dialysis, instrumental measurements and serum dosages of cTnI were carried out at the onset and after three months, using first and second generation methods. Among the patients who tested positive using the above tests, 4 acute cardiac events were observed. A follow-up of the present study is due in one year's time.

Hemodialysis with two sequential hemodialyzers.

BACKGROUND/AIMS: The principal aims of the new hemodialysis methods are: a short-time dialysis session, the increase of solute removal, the patient's well-being and, when possible, the reduction of global costs. Other researchers have experimented the simultaneous use of two hemodialyzers in hemodialysis. We tested a new technique which involves the use of two Cuprophan hemodialyzers in sequence (double filter system: DFS), each one connected separately to fresh dialysate. METHODS: We treated 15 large patients with DFS and compared the results with conventional hemodialysis (CHD). RESULTS: Our results showed a significant difference between CHD and DFS in the depuration values. After the first hemodialyzer, modification of pH and electrolytes occurred in the plasma composition. In the second hemodialyzer, urea depuration occurred without further significant changes in hydroelectrolytic and acid-basic plasma patterns. The Kt/V increased from 1.10 to 1.29 (18%). CONCLUSION: Our technique is conceived for the following goal: to increase the diffusion of solution without increasing costs and side effects.

Normal serum biochemical and hematological parameters in Macaca fascicularis.

The effects of age, sex, pregnancy, were analyzed and data from fasted and fed animals were compared in a population of cynomolgus macaques. No significant sex effects were observed for biochemical values and no changes were found in male hematological parameters in relation to age. Most values of females during pregnancy were within normal ranges. Comparison between fed and fasted animals showed that several biochemical parameters (e.g., ALT, glucose, CPK, LDH) and several hematological parameters (e.g., monocytes, eosinophils, basophils, hemoglobin, MCV, MCHC, and MCH) were affected by food intake.