Improper waste disposal of silver-mercury amalgam.

The objective of this work was to estimate the quantity of mercury residue present in dental amalgam that is generated and discarded in the city of Manaus (Amazon-Brazil). For this purpose, the locations of amalgam usage (10 public and 31 private dental clinics), the method by which the residue is discarded (14 clinics improper disposal), and the analysis of total mercury in the sediment of the controlled landfill (2.68-3 µgHg/g), were described. It was concluded that: there are dental clinics in the city that discard mercury residue into the common waste disposal system, which contravenes health safety standards.

Cadmium-induced disruption of environmental exploration and chemical communication in matrinxã, Brycon amazonicus.

The effects of cadmium exposure on both environment exploration and behavioral responses induced by alarm substance in matrinxã (Brycon amazonicus), a fish species endemic to the Amazon basin, were investigated. Fish exposed to 9.04+/-0.07 microg/L waterborne cadmium for 96h followed by 24h depuration period in clean water, were video-recorded for 15 min, followed by immediate introduction of conspecific skin extract to the tank and a new 30 min period of fish video-recording. Cd-exposed matrinxã showed a significantly lowered locomotor activity (t-test t(12)=2.7; p=0.025) and spatial distribution (t-test t(12)=2.4; p=0.03) relative to the unexposed control fish prior to the alarm substance introduction, and did not present any significant reaction when the skin extract was introduced. The control fish, in opposite, showed a higher level of activity and spatial distribution prior the skin extract contact and significantly decreased their response after the chemical stimulus (locomotion-repeated-measure ANOVA F(1,11)=5.6; p=0.04; spatial distribution F(1,11)=19.4; p=0.001). In conclusion, exposure to a low level of cadmium affects both the environment exploration performance and the conspecific chemical communication in matrinxã. If the reduced environmental exploration performance of Cd-exposed fish is an adjustment to the compromised chemical communication or an independent effect of cadmium is the next step to be investigated.

Crystallization, preliminary X-ray analysis and molecular-replacement solution of haemoglobin-II from the fish matrinxã (Brycon cephalus).

Haemoglobins constitute a set of proteins with interesting structural and functional properties, especially when the two large animal groups reptiles and fishes are focused on. Here, the crystallization and preliminary X-ray analysis of haemoglobin-II from the South American fish matrinxã (Brycon cephalus) is reported. X-ray diffraction data have been collected to 3.0 A resolution using synchrotron radiation (LNLS). Crystals were determined to belong to space group P2(1) and preliminary structural analysis revealed the presence of two tetramers in the asymmetric unit. The structure was determined using the standard molecular-replacement technique.

Crystallization, preliminary X-ray analysis and molecular-replacement solution of the carboxy form of haemoglobin I from the fish Brycon cephalus.

Haemoglobin, the 'honorary enzyme' [Brunori (1999), Trends Biochem. Sci. 24, 158-161], constitutes a prime prototype for allosteric models. Here, the crystallization and preliminary X-ray analysis of haemoglobin I from the South American fish Brycon cephalus are reported. X-ray diffraction data have been collected to 2.5 A resolution using synchrotron radiation (LNLS). Crystals were determined to belong to the space group P6(1)22 and preliminary structural analysis revealed the presence of one dimer (alphabeta) in the asymmetric unit. The structure was determined using standard molecular-replacement techniques.

Purification, crystallization and preliminary x-ray diffraction analysis of carboxyhaemoglobin-II from the fish Piaractus mesopotamicus (pacu).

Carboxyhaemoglobin-II isolated from the pacu (Piaractus mesopotamicus) has been crystallized and X-ray diffraction data were collected to 2.0 A resolution using synchrotron radiation. Crystals were characterized as belonging to the space group I23; preliminary structural analysis reveals the presence of one dimer in the asymmetric unit.

Identificacao e incidencia de germes anaerobios em amostras enviadas a Secao de Microbiologia do Laboratorio Central do Hospital das Clinicas da FMUSP. / Identification and incidence of anaerobic bacteria in samples sent to the Microbiological Section of the Central Laboratory of the Hospital das Clinicas of the Faculdade de Medicina of the University of Sao Paulo

Foram realizadas culturas em anaerobiose de 250 amostras organicas diversas de pacientes hospitalizados. Resultados positivos para bacterias anaerobias foram obtidos em 32%, demonstrando assim a importancia desse procedimento para o diagnostico e tratamento de infeccoes em pacientes hospitalizados. Os resultados foram semelhantes aos obtidos atraves de metodos diferentes usados por outros autores