Assessment of the causes of Hg bioaccumulation in the fish of a Mediterranean lagoon subject to environmental management interventions.

In a Mediterranean lagoon characterized by high levels of Hg in the sediment, Hg content in commercial fish species was determined, and, in order to establish Hg concentration in the water column, Diffusive Gradient in Thin films technique (DGT) was used. The results allowed to state (1) the disturbance of the surface sediment and its resuspension in the water column did not cause detectable increase in Hg releases, (2) the East basin acted more than the West one in contamination of fish species, (3) the small-sized sea-breams (<400 g) were more contaminated than larger sizes ones (>400 g). We concluded: (1) fish contamination may also depend on direct contact with releases of the contaminant and small, gregarious and less sedentary subjects are more likely to incur releases of Hg; (2) Hg releases can be greater in areas with a relatively low sedimentary organic matter load compared to areas subjected to high density macroalgal mat, regardless of the amount of Hg present in the sediments; (3) wind transport of plant masses in low energy storage areas, may constitute an increase factor of Hg in the sediment. A critical review of the results was made in comparison with the available literature reports and some hypotheses were proposed regarding the possible dynamics and availability of the contaminant.

Autologous CD133+ cells augment the effect of portal embolization.

AIM: The standard to treat liver tumors is a resection. When the future liver remnant (FLRV) is below 30% (healthy livers) or 40% (cirrhotic livers or previous chemotherapy), surgery carries the risk of severe complications. Portal vein embolization (PVE) gained a worldwide diffusion as a tool to augment the FLRV. Cell therapies are recent players at the frontiers of medicine. This study presents a clinical experience to evaluate the synergistic effect of combined PVE and autologous CD133+ cells coadministration. METHODS: Sixteen patients have been enrolled in the study up today. Inclusion criteria were: primary or metastatic liver malignancy with a FLRV<30% or 40%. A baseline volumetric CT-scan was obtained. CD34+ were mobilized to the blood stream by G-CSF administration and collected by immunomagnetic separation. Simultaneously with PVE, cells were administered to the non occluded liver segments. Follow-up CT scans were taken at 30th post treatment day. RESULTS: The patients (N.=6) showed an increased volume gain (Mann-Whitney test P<0.001, two sided) compared to a set of cases whose treatment was PVE only (N.=10). DISCUSSION: The use of autologous stem cells as an augmenter of liver regeneration has a clinical potential to improve the resectability of liver tumors.

Arsenic-resistant bacteria isolated from contaminated sediments of the Orbetello Lagoon, Italy, and their characterization.

AIMS: The aim of this study was to isolate arsenic-resistant bacteria from contaminated sediment of the Orbetello Lagoon, Italy, to characterize isolates for As(III), As(V), heavy metals resistance, and from the phylogenetic point of view. METHODS AND RESULTS: Enrichment cultures were carried out in the presence of 6.75 mmol l(-1) of As(III), allowing isolation of ten bacterial strains. Four isolates, ORAs1, ORAs2, ORAs5 and ORAs6, showed minimum inhibitory concentration values equal or superior to 16.68 mmol l(-1) and 133.47 mmol l(-1) in the presence of As(III) and As(V), respectively. Isolate ORAs2 showed values of 1.8 mmol l(-1) in the presence of Cd(II) and 7.7 mmol l(-1) of Zn(II), and isolate ORAs1 pointed out a value of 8.0 mmol l(-1) in the presence of Cu(II). Analysis of 16S rRNA gene sequences revealed that they can be grouped in the three genera Aeromonas, Bacillus and Pseudomonas. Phylogenetic analysis of the four more arsenic-resistant strains was also performed. CONCLUSION: Isolates are highly resistant to both As(III) and As(V) and they could represent good candidates for bioremediation processes of native polluted sediments. SIGNIFICANCE AND IMPACT OF THE STUDY: This study provides original results on levels of resistance to arsenic and to assigning genera of bacterial strains isolated from arsenic-polluted sediments.

Enhanced levels of oxidized low-density lipoprotein prime monocytes to cytokine overproduction via upregulation of CD14 and toll-like receptor 4 in unstable angina.

OBJECTIVES: The purpose of this study was to establish whether oxidized low-density lipoprotein (oxLDL) contributes to cytokine overproduction via upregulation of CD14 and toll-like receptor-4 (TLR-4) expression on circulating monocytes of unstable angina (UA) patients. METHODS AND RESULTS: Expression of CD14 and TLR-4 on circulating monocytes, and the concentration of plasma oxLDL, (interleukin [IL])-6, IL-1 beta, IL-8, tumor necrosis factor (TNF)-alpha, monocyte chemoattractant protein-1 (MCP-1) were measured in 27 control (C) subjects, 29 patients with stable angina (SA), and 27 with UA. CD14 and TLR-4 expression on monocytes and circulating IL-6, IL-1 beta, and oxLDL were higher in UA than in SA and C subjects (P<0.001). In in vitro experiments, oxLDL increased CD14 and TLR-4 expression (P<0.001) in control monocytes as well as IL-6, IL-1 beta, and at a lower extent TNF-alpha and MCP-1 levels in the supernatant (P from <0.05 to <0.001). The preincubation of sera derived from UA patients but with control monocytes also induced a significant increase of CD14 and TLR-4 expression (P<0.001) and of IL-6 and IL-1 beta production (P<0.001) in the supernatant. CONCLUSIONS: In UA patients oxLDL may contribute to monocyte overproduction of some cytokines by upregulating CD14 and TLR-4 expression.

Interações de bebês em creche / Infant's interactions at day care

O artigo trata de eventos interativos de bebês com coetâneos. Inicialmente, abordamos concepções e métodos de estudo sobre interação de bebês na literatura, a partir da década de 1970. A seguir, apresentamos estudo empírico realizado através da análise de gravações em vídeo do projeto Processos de adaptação de bebês a creche, que acompanhou 21 bebês (4-14 meses) em creche universitária. A investigação deu-se em duas fases. A primeira, pela identificação de episódios interativos envolvendo os 21 bebês, considerando-se interação como fazer algo juntos. A segunda, pela análise microgenética dos episódios interativos de um bebê. Tal análise revelou freqüentes, fluidas e entrecortadas interações, que ultrapassam o fazer algo juntos, podendo o comportamento ser regulado mesmo à distância e mesmo que um dos parceiros não saiba que está regulando o comportamento do outro. Isso nos levou a tratar as interações como ocorrendo em um campo interativo, através da concepção de co-regulação do comportamento (AU)

Interações de bebês em creche / Infant's interactions at day care

O artigo trata de eventos interativos de bebês com coetâneos. Inicialmente, abordamos concepções e métodos de estudo sobre interação de bebês na literatura, a partir da década de 1970. A seguir, apresentamos estudo empírico realizado através da análise de gravações em vídeo do projeto Processos de adaptação de bebês a creche, que acompanhou 21 bebês (4-14 meses) em creche universitária. A investigação deu-se em duas fases. A primeira, pela identificação de episódios interativos envolvendo os 21 bebês, considerando-se interação como fazer algo juntos. A segunda, pela análise microgenética dos episódios interativos de um bebê. Tal análise revelou freqüentes, fluidas e entrecortadas interações, que ultrapassam o fazer algo juntos, podendo o comportamento ser regulado mesmo à distância e mesmo que um dos parceiros não saiba que está regulando o comportamento do outro. Isso nos levou a tratar as interações como ocorrendo em um campo interativo, através da concepção de co-regulação do comportamento.

A incompletude como virtude: interação de bebês na creche / Incompleteness as a virtue: interaction of babies at day care

Neste artigo, mostramos algumas características dos processos interativos de crianças fundamentalmente no 1º ano de vida, através do estudo de alguns episódios de interação, recortados através do registro em vídeo, durante pesquisa em uma creche universitária, com crianças (7 a 14 meses) brincando livremente. Num primeiro momento, mostramos a importância da definição de um conceito de interação que consiga captar e traduzir as características das interações ocorridas nessa faixa de idade. Também, mostramos a importância dos procedimentos metodológicos, usados para recortar o material empírico, na definição desse conceito de interação. Nessa faixa etária, os episódios de interação encontrados são bastante rápidos e desordenados e estas características são resultantes, em grande parte, do desajeitamento motor dos bebês. Esta incompletude motora, por sua vez, pode ser um elemento capaz de prolongar um episódio de interação entre crianças pequenas e/ou mesmo propiciar o surgimento de novos episódios de interação (AU)

A incompletude como virtude: interação de bebês na creche / Incompleteness as a virtue: interaction of babies at day care

Neste artigo, mostramos algumas características dos processos interativos de crianças fundamentalmente no 1º ano de vida, através do estudo de alguns episódios de interaçäo, recortados através do registro em vídeo, durante pesquisa em uma creche universitária, com crianças (7 a 14 meses) brincando livremente. Num primeiro momento, mostramos a importância da definiçäo de um conceito de interaçäo que consiga captar e traduzir as características das interaçöes ocorridas nessa faixa de idade. Também, mostramos a importância dos procedimentos metodológicos, usados para recortar o material empírico, na definiçäo desse conceito de interaçäo. Nessa faixa etária, os episódios de interaçäo encontrados säo bastante rápidos e desordenados e estas características säo resultantes, em grande parte, do desajeitamento motor dos bebês. Esta incompletude motora, por sua vez, pode ser um elemento capaz de prolongar um episódio de interaçäo entre crianças pequenas e/ou mesmo propiciar o surgimento de novos episódios de interaçäo

Crianças pequenas brincando em creche: a possibilidade de múltiplos pontos de vista / Multiple perspectives about young infants playing at day care

Este trabalho surgiu como um foco secundário de uma pesquisa sobre interação criança-criança. Nesse estudo é proposto um meta-olhar sobre o fazer do pesquisador, analisando o próprio coletar dos dados, com a idéia de que os dados não são dados, mas construídos na interação entre a rede de significações do pesquisador e os eventos no aqui-e-agora da situação observada. Assim, partindo do pressuposto da incapacidade estrutural humana de um acesso a uma realidade externa independente (Maturana & Varela), este segundo foco de pesquisa delimita três perspectivas diversas sobre os dados coletados, a serem igualmente consideradas: 1) a perspectiva do pesquisador; 2) a das educadoras envolvidas no cuidado das crianças; 3) a das próprias crianças. Essas perspectivas mostraram-se freqüentemente divergentes. Os episódios apresentados nesse trabalho permitem uma análise dessa diversidade de perspectivas, propiciando interpretações e ações que por vezes ocasionam desencontros ou interrupções nas interpretações e no fluxo de interações (AU)

Crianças pequenas brincando em creche: a possibilidade de múltiplos pontos de vista / Multiple perspectives about young infants playing at day care

Este trabalho surgiu como um foco secundário de uma pesquisa sobre interaçäo criança-criança. Nesse estudo é proposto um meta-olhar sobre o fazer do pesquisador, analisando o próprio "coletar dos dados", com a idéia de que os dados näo säo dados, mas construídos na interaçäo entre a rede de significaçöes do pesquisador e os eventos no aqui-e-agora da situaçäo observada. Assim, partindo do pressuposto da incapacidade estrutural humana de um acesso a uma realidade externa independente (Maturana & Varela), este segundo foco de pesquisa delimita três perspectivas diversas sobre os "dados coletados", a serem igualmente consideradas: 1) a perspectiva do pesquisador; 2) a das educadoras envolvidas no cuidado das crianças; 3) a das próprias crianças. Essas perspectivas mostraram-se freqüentemente divergentes. Os episódios apresentados nesse trabalho permitem uma análise dessa diversidade de perspectivas, propiciando interpretaçöes e açöes que por vezes ocasionam desencontros ou interrupçöes nas interpretaçöes e no fluxo de interaçöes.

Biomarker responses at different levels of biological organisation in crabs (Carcinus aestuarii) experimentally exposed to benzo(alpha)pyrene.

The aim of this study was to validate a multi-trial biomarker approach for the evaluation of toxicological risk due to benzo(alpha)pyrene. Carcinus aestuarii, exposed to increasing concentrations of B(alpha)P in the water, was used as the bioindicator organism. A set of biomarkers were tested in order to: identify biological materials for biomarker and residue analysis; determine a group of sensitive techniques for the assessment of PAH contamination; investigate correlation between responses at different levels of biological organisation. The results underlined that BPMO activities in hepatopancreas and gills were a good biomarker of exposure to PAH-type compounds. B esterases activities in hemolymph and porphyrin patterns in excreta could be proposed as a non-destructive approach for evaluating chemical exposure in this species.

The effect of complete versus incomplete information on odour discrimination in a parasitic wasp.

We studied the function of learning in the parasitoid Leptopilina heterotoma by looking at discrimination of odour stimuli used in foraging for a host. To optimize the rate of encounters with hosts, these parasitoids are expected to assess the extent to which variation in host-substrate odours is reliably associated with variation in the presence of hosts, that is, substrate profitability. Where the association is reliable, parasitoids should attend to variation in odours and discriminate between them; where it is not, they should ignore it. We hypothesized that foraging decisions are based on the completeness of information the animal has about differences in substrate profitabilities. Our laboratory studies showed that discrimination and non-discrimination of odour stimuli are dynamic behavioural decisions that can be related to the degree of substrate variation and to an animal's informational state. In wind-tunnel studies, females learned to discriminate between odours from substrates that were qualitatively different, for example, between odours from apple and pear substrates or between yeast substrates with different C6 compounds added. They did not discriminate when differences were small (e.g. between odours from two apple varieties or between yeast patches with different concentrations of ethyl acetate), unless unrewarding experiences provided evidence of the absence of hosts in one of the substrates. Hence, we suggest that non-discrimination between odour stimuli in L. heterotoma is not a lack of ability to discriminate but a functional decision by the parasitoid. Copyright 1998 The Association for the Study of Animal Behaviour. Copyright 1998 The Association for the Study of Animal Behaviour.

Mercury levels along the food chain and risk for exposed populations.

Mercury was not regarded as a pollutant of primary importance until many deaths due to mercury poisoning occurred in the 1950s. More recently, adverse health effects have been documented at relatively low exposure levels, and monitoring data must now be interpreted in this light. The Mediterranean basin has been studied in great detail over the past 20 years because of the anomalous natural presence of mercury. Marine animals of this basin have higher mercury body burdens than the same (or similar) species in the Atlantic. The mercury found in marine organisms is mainly in the form of methyl mercury. Long-term and frequent intake of seafood with high mercury levels by populations living in coastal fishing villages is associated with a toxic risk, especially in pregnant women. High blood and hair concentrations of mercury have repeatedly been found in fishermen of Tyrrhenian coastal villages. In some cases these concentrations have been associated with an increase in DNA damage in blood cells. High mercury levels in hair and blood of people from a fishing village of Madeira have also been found. This information deserves renewed scrutiny with regard to preventive efforts needed.

A putative new peptide synthase operon in Bacillus subtilis: partial characterization.

A large operon-type structure has been located between the gltA and citB loci on the Bacillus subtilis chromosome. On the basis of the analysis of the 25 kb sequenced so far, it potentially encodes at least three large proteins which contain structural motifs associated with the subunits of all characterized peptide synthases. The amino acid recognition specificity of this new peptide synthase is discussed in the light of sequence homology with other synthases.

Cytogenetic monitoring of fishermen with environmental mercury exposure.

Due to high mercury levels in many Mediterranean aquatic organisms, people who live in this area and consume large amounts of seafood are exposed to a toxicological hazard. A group of 51 fishermen exposed to mercury through eating contaminated seafood from the northern Tyrrhenian Sea underwent cytogenetic monitoring. This work is part of a research project consisting of the evaluation of micronuclei (MN), chromosomal aberrations (CA) and sister-chromatid exchanges (SCE) in peripheral blood lymphocytes. Here we present data on mercury levels in blood and on micronucleus frequencies in peripheral blood lymphocytes of fishermen. The range of mercury concentrations in blood was 10.08-304.11 ng/g fresh weight, the average was 88.97 +/- 54.09 ng/g. Micronucleus frequency was defined with at least 2000 binucleated cells scored for each person; the average was 8.74 +/- 2.56 expressed on 1000 binucleated cells. A statistical correlation was found between MN frequency and total mercury concentration in blood (p = 0.00041, r = 0.674), as well as between MN frequency and age (p = 0.017). No other parameters taken into account correlated with MN frequency.

A new human growth hormone production process using a recombinant Bacillus subtilis strain.

We constructed a series of hybrid plasmids which directed the synthesis of different human growth hormone (hGH) precursor sequences in Bacillus subtilis. In addition to the 191 amino acids of the hormone, the precursors had in common an amino-terminal extension characterized by the presence of a methionine at position 1 and of the tetrapeptide Ile-Glu-Gly-Arg preceding the first residue (Phe) of hGH. The sequence between the methionine and the tetrapeptide was specific for each precursor and, because of the presence of charged residues, conferred particular properties to the molecules. Long homopolymeric tail-containing precursors such as MRRRRRRIILM-IEGR appeared insoluble whereas shorter sequences of the type MRR-IEGR and MEELM-IEGR augmented the solubility of the precursors with respect to Met-hGH. The soluble precursors could be easily purified from the bulk proteins taking advantage of the charged residues present on the N-terminal tail. After purification, the natural hGH was obtained by treating the precursors with the protease Factor Xa which cleaves after the arginine residue of the tetrapeptide IEGR. A protocol for the production and purification of authentic hGH from a strain expressing one of these soluble precursors is reported.

Polychlorinated biphenyl congeners, hexachlorobenzene and DDTs in human milk in central Italy.

The concentration of organochlorine pesticides (hexachlorobenzene, p,p'-DDT and p,p'-DDE) and polychlorinated biphenyl (PCB) congeners in human milk from 56 donors in the hospitals of two Italian towns (Certaldo and Grosseto) are reported. The highest levels found were those of p,p'-DDE, which reached a mean of 2276 ng g-1 at Certaldo and 2270 ng g-1 at Grosseto, p,p'-DDT levels were about an order of magnitude less, with means of 350 and 298 ng g-1, respectively. The DDE/DDT ratio was approximately 8, which is much higher than that found in previous studies. Mean total PCBs were 451 and 295 ng g-1, respectively. About 70% of the PCB residues in the sample analysed consisted of only three congeners: 2,2',4,4',5,5' (IUPAC No. 153), 2,2',3,4,4',5' (138) and 2,2',3,4,4',5,5' (180).

Identification of sulfurtransferase enzymes in Azotobacter vinelandii.

Rhodanese and 3-mercaptopyruvate sulphurtransferase have been identified in A. vinelandii. Two distinct active fractions of the two sulphur transferases were obtained after FPLC ion-exchange chromatography of material partially purified from crude extracts. Rhodanese has been purified to homogeneity, and it consists of one polypeptide chain of Mr ca 25,000. A partial purification of 3-mercaptopyruvate sulphurtransferase was obtained.

Structural analysis of poly(ADP-ribose)polymerase in higher and lower eukaryotes.

A phylogenetic survey for the poly(ADP-ribose)polymerase has been conducted by analyzing enzyme activity in various organisms and determining the structure of the catalytic peptides by renaturation of functional activities of the enzyme in situ after electrophoresis in denaturing conditions (activity gel). The enzyme is widely distributed in cells from all different classes of vertebrates, from arthropods, mollusks and plant cells but could not be detected in echinoderms, nematodes, platyhelminths, thallophytes (including yeast) and bacteria. The presence on activity gels of a catalytic peptide with Mr = 115,000-120,000 was demonstrated in vertebrates, arthropods and mollusks but no activity bands were recovered in many lower eukaryotes, in plant cells and bacteria. By using an immunological procedure that used an antiserum against homogeneous calf thymus poly(ADP-ribose) polymerase, common immunoreactive peptides were visualized in mammals, avians, reptiles, amphibians and fishes, while lacking in non-vertebrate organisms. Our results indicate that the structure of poly(ADP-ribose) polymerase is conserved down to the mollusks suggesting its important role for DNA metabolism of multicellular organisms.

Calcium and polyphosphoinositides: their distribution in relation to the membrane changes occurring in the head of boar spermatozoa.

Ejaculated boar spermatozoa, previously incubated in a rigorously Ca++-free medium, were exposed to Ca++ for different incubation times and processed for the detection of Ca++ localization by a pyroantimonate technique. The distribution of polyphosphoinositides, anionic phospholipids natural constituents of membrane known to bind Ca++, was investigated using a specific cytochemical probe, i.e., neomycin conjugated with horseradish peroxidase. The in situ localizations thus obtained revealed: short exposure to Ca++ ions (10 min) evocated a Ca++-induced release of calcium from the nonmitochondrial intracellular store, i.e., the outer acrosomal membrane; a more prolonged exposure (20 min) triggered the occurrence of fusional and exocytotic events, that appeared to be morphologically related to the acrosome reaction; the outer acrosomal membrane, which is the fusigenic sperm membrane, was the elective site of the neomycin/peroxidase labeling. When assayed for the presence of a phospholipase C-like activity, the detergent extract obtained from boar spermatozoa exhibited substantial amount of p-nitrophenyl-phosphorylcholine hydrolyzing activity. The results, on the whole, allow us to suggest a relationship between Ca++ and polyphosphoinositides turnover in the events triggering the acrosome reaction, the exocytotic process peculiar to mammalian spermatozoa.