Survey of ethylenethiourea (ETU) in ethylenebis(dithiocarbamate) (EBDC) fungicides

Ethylenethiourea (ETU) has been recognized as a compound with adverse toxicological properties. It may occur in ethylenebis(dithiocarbamate) (EBDC) fungicides as a by-product and/or a degradation product. Restrictions have been issued by the Italian Health Authority to keep the level of ETU in EBDC formulations under 0.5% (on an EBDC technical product basis). A survey was carried out on 85 samples of commercial formulations from the Italian market to verify compliance with the above limitation. ETU was extracted by methanol and determined by gas chromatography with a flame ionization detector. Three of the 85 samples (3.5%) exceeded the limit of 0.5% established by the Italian legislation for ETU.     

Diagnostic image (5) (Ileum pathology)

In a 28-year-old woman Crohn's disease was diagnosed. She had drug treatment but the situation deteriorated and ileocoecal resection was carried out. In the surgical specimen the diagnosis was confirmed.     

Sorption of Phosphate and Cr(VI) by Fe(III) and Cr(III) Hydroxides

Understanding the chemical behavior and interactions of Cr(VI) (e.g., HCrO₄ ⁻) and other anions, such as orthophosphate (P) with insoluble metal hydroxides (i.e., Cr[III] and Fe[III]) in disposal landfills or in chromite ore processing residue (CORP)–enriched soil is very important in predicting the movement and the fate of Cr(VI). This study evaluates the sorption behavior of P and Cr(VI) by Fe(III) (i.e., ferrihydrite), Cr(III) (i.e., Cr[OH]₃), and coprecipitated Fe(III)/Cr(III) hydroxides. These metal hydroxide sorbents were synthesized, and sorption of P and Cr(VI) were conducted at different pH using a batch technology. Our results show that P and Cr(VI) sorption by metal hydroxides decreased with increasing suspension pH. Greater decrease in P sorption was observed when Cr(III) was present in the structures of hydroxides. Following the sorption of low concentration of P (i.e., 0.5 mM), the sorption of subsequently added Cr(VI) by hydroxides was less influenced. However, Cr(VI) sorption was greatly inhibited when high concentration of P (i.e., 10 mM) prereacted with hydroxides, particularly in Fe(III) hydroxide system. Results also indicated that high concentration of Cr(VI) (10 mM) could dissolve Cr(III) hydroxide at pH 3 and reprecipitate as an amorphous form of Cr(VI) and Cr(III) compound at pH about 6.5. Although coprecipitation of Cr(VI) with Cr(III) can inhibit Cr(VI) movement through soil profiles, the inhibition seems to be low due to the gradual release of Cr(VI) with increasing pH. Received: 16 April 2002/Accepted: 29 October 2002     

Crusted (Norwegian) scabies in Dakar (Senegal)

Between January 1993 and June 1997, 30 patients with crusted scabies were seen at the dermatological clinic in Dakar (Senegal). Seventeen of these patients were male and 13 were female. Six were children aged 5 to 15 years and 24 were adults aged 18 to 70 years. Diagnosis of crusted scabies was straightforward because this condition, which was rare in Dakar before 1990, has become much more common and is now familiar to Senegalese dermatologists. The infection presented as an extensive scaly or crusted eruption with symmetrical lesions affecting the hands, feet, knees, elbows and ears in particular. Scalp involvement was reported in 25 patients. Erythrodermia was present in 4 cases and pachyonychia in 4 cases. Twenty-seven of the 30 patients had moderate or severe pruritus, whereas an absence of pruritus is regarded as a classical characteristic of crusted scabies. Diagnosis was readily confirmed by examination of hyperkeratotic material under the microscope: numerous mites and eggs were present. The two most common etiological factors were auto-immune diseases (6 cases, 4 of whom were receiving no steroid or other immunosuppressive treatment at the time of onset of crusted scabies) and malnutrition (5 of the 6 children in the study). The other associated conditions identified were: physical debilitation (4 cases), HIV infection (3), mental disability-Down's syndrome (3) and long term use of topical steroids for artificial depigmentation (2). Two patients were immunocompetent and 5 patients died shortly after diagnosis, before any underlying conditions could be identified. Seven patients were cured with benzyl benzoate. Seven others, all adults, received a single oral dose of ivermectin (200 mg/kg) and topical kerolytic drugs. Ivermectin was ineffective in 1 case, and an improvement was observed in another case, although a complete cure was achieved only after a second dose. The other patients were all cured and showed no signs of scabies one month after ivermectin treatment. A recurrence was observed in 3 patients a few months later however, suggesting that these patients were reinfected. No side effects were reported in any of the patients treated with ivermectin.     

The two PM(2.5) (fine) and PM(2.5-10) (coarse) fractions: evidence of different biological activity.

Recent studies have shown that an increased concentration of environmental particulate matter (PM(10)) is related to many respiratory diseases. One major issue is whether the toxicity of the particles resides in some particular fraction as defined by chemical composition and size. The overall purpose of this study was to compare the in vitro toxicity of coarse (PM(2.5-10)) and fine (PM(2.5)) particulate matter, collected in an urban area of Rome, in relation to their physicochemical composition as assessed by analytic electron microscopy and atomic absorption spectroscopy. In particular, our aim was to evaluate the importance of particle physicochemical components in the induced toxicity. The in vitro toxicity assays used included human red blood cell hemolysis, cell viability, and nitric oxide (NO) release in the RAW 264.7 macrophage cell line. The hemolytic potential has been widely used as an in vitro toxicity screen and as a useful indicator of oxidative damage to biomembranes. We found that human erythrocytes underwent dose-dependent hemolysis when they were incubated with varying concentrations of fine and coarse particles. The hemolytic potential was greater for the fine particles than for the coarse particles in equal mass concentration. However, when data were expressed in terms of PM surface per volume unit of suspension, the two fractions did not show any significant hemolytic differences. This result suggested that the oxidative stress induced by PM on the cell membranes could be due mainly to the interaction between the particle surfaces and the cell membranes. RAW 264.7 macrophage cells challenged with particles showed decreased viability and an increased release of NO, a key inflammatory mediator, and both effects were not dose dependent in the tested concentration range. The fine particles were the most effective and the differences between the two size fractions in inducing these biological effects remained unchanged when the basis of comparison was changed from weight to surface measures. It seemed therefore that these differences relied on the different physicochemical nature of the particles. The main chemical difference between the two fractions resided in a greater abundance of C-rich particles with S traces in the fine fraction. Therefore, we cautiously suggest a role for these particles in the induction of toxicity.     

Diagnostic image (6) (Pustulous skin lesions)

During chemotherapy a 35-year-old woman developed pustulous skin lesions. Biopsies of these lesions showed Candida albicans. Blood cultures were positive for C. albicans. The patient died.