No abstract

Objectives: Among the diverse forms of amyloidosis, secondary type is the most frequent one. Diagnosis of amyloid deposition is based on the identification of the fibrillary protein amyloid by means of Congo Red (CR) or crystal violet (CV) stains, but these techniques do not differentiate between the different types of amyloid fibrils. The aim of this study was to identify by immunofluorescence (IF) AA amyloid a pathological fibrillar low-molecularweight protein formed by cleavage of serum amyloid A (SAA) protein in labial salivary gland (LSG) biopsies from patients with secondary amyloidosis. Study design: 98 LSG were studied, 65 were from patients with secondary amyloidosis and 33 from subjects with chronic inflammatory diseases without evidence of this anomaly. All sections were stained with hematoxylin and eosin (H&E), CV, CR and IF using anti-AA antibodies. Positive and negative controls were used for all techniques.Results: CV and CR demonstrated that the amyloid substance was found mainly distributed periductally (93.8%), followed by periacinar and perivascular locations (p<0.001); however, the IF demonstrated that amyloid AA substance predominates in the periacinar area (73.8%), followed by periductal and perivascular locations (p<0.001). IF has a sensitivity of 83%, 100% of specificity, 100% of predictive positive value and 75% of predictive negative value.Conclusions: The results of this study confirm the efficacy of the LSG biopsy as a highly reliable method for diagnosis of secondary amyloidosis.

The marine shore tailings deposit at the Bahía de Ite, Atacama desert, Southern Peru was studied in order to understand the biogeochemical processes resulting from the construction of a wetland on the oxidizing tailings. For this purpose, un-remediated and remediated parts of the tailings were studied by solid and aqueous geochemistry, mineralogy, and microbiology methods. Preliminary results show that the oxidizing tailings have a low-pH oxidation zone (pH 1-4) with a strong accumulation of efflorescent salts (10-20 cm thick) at the surface due to the upward capillary transport of metal cations in the arid climate (up to 800 mg/L Fe, 160 mg/L Cu, 15 mg/L Zn, 70 mg/L Mn, 0.2 mg/L Cd, 1.3 mg/L Co and 2.5 mg/L Ni). In contrast, these bivalent metals occur in very low concentrations (mainly under the detection limit) below the wetland due to the established near neutral pH and reducing conditions (~150 mV). The alkaline waters (pH 8) that infiltrated into the Bahía de Ite tailings deposit contained high natural background arsenic concentrations (~500 µg/L As). The preliminary data suggest that the infiltration of the wetland induced retention of the metal cations and the formation of a Fe(II) plume. The Fe(II) plume was pushed toward the sea due to the increased hydraulic pressure of the wetland, where, in contact with the more oxidizing (400 mV) and alkaline sea water, the precipitation of Fe(III) hydroxides was triggered in the area of the shore line. In the shoreline samples, the As concentrations in the pore water are below the detection limit, suggesting that the As is retained by the Fe(III) hydroxide. This conclusion was confirmed by sequential extraction data.

Preliminary results of a microbiologal study of the marine shore tailings disposal at the Bahia de Ite (tailings from Toquepala and Cuajone porphyry copper mines, Peru) are presented. The goal of the study is to understand the microbiological communities and its distribution in the tailings profiles before and after the installation of a wetland on the marine shore tailings deposit. The tailings have low sulfide (~2 wt% pyrite equivalent) and low carbonate contents. Molecular based methods, mainly terminal restriction fragment length polymorphism (T-RFLP), cloning and sequencing as well as cultivation methods were applied to characterize the microorganisms. Iron/sulfur oxidizing bacteria (e.g. Leptospirillum, Acidithiobacillus and Sulfobacillus-like) and heterotrophs (e.g. Acidiphilium and Acidobacterium-like) were present in the still oxidizing tailings. The maximum bacteria, as determined by total cell count, were detected at the oxidation front where sulfide minerals as pyrite and oxygen are both available. These tailings are characterized by a low biomass and a low bacterial diversity. In the remediated zone, due to the less extreme condition, the bacterial diversity was higher and a dominance of heterotrophs and sulfate reducing bacteria (SRB) were expected in this zone.