Water as Veneering Modeling Liquid Affects Microhardness of Glassy Matrix Veneering Ceramic.

PURPOSE/AIM: To evaluate the effect of different veneering liquids used for modeling on microhardness, fracture toughness and biaxial flexural strength of a glass-veneering ceramic. MATERIAL AND METHODS: The manufacturer recommended modeling liquid (ML), distilled water (DW), isopropyl alcohol (IA), 0.5% (P05), 1% (P1), and 2% (P2) polyethylene glycol solutions were mixed with feldspathic ceramic powder to form disc-shaped samples (n=20, 15 mm × 1.2 mm). After sintering, samples were mirror-polished and subjected to Vickers indentation (n=5) for measurement of microhardness and fracture toughness. The remaining 15 samples from each group were subjected to biaxial flexural strength. Data were subjected to one-way ANOVA and Weibull analysis. RESULTS: The microhardness was affected by veneering liquid (p=0.002): DW promoted higher microhardness values than ML and IA. Fracture toughness (p=0.301) and flexural strength (p=0.930) were not affected by the veneering liquid but Weibull parameters were affected. All groups presented surface pores under high magnification. CONCLUSION: Even though the use of DW led to higher values of surface microhardness than the ML, all obtained values are inside the range of enamel microhardness values reported in the literature. Such parameters may affect antagonist wear and should be reported in clinical trials.

Association of positive and negative life events with cognitive performance and psychological status in late life: A cross-sectional study in Northern Portugal.

Objectives: Life events have important effects on psychological well-being. Yet, studies have mainly focused on exploring the impact of traumatic and negative experiences on health and well-being, with positive events receiving marginal attention. In this study, we investigated the association between negative and positive life events, cognitive performance and psychological status in older individuals. Method: A cross-sectional approach with a sample of 97 community-dwelling adults, recruited from a network of 23 centres/institutions in Northern Portugal, and aged between 56 and 85 years, was conducted. All participants were evaluated through a battery of tests assessing for depressive mood, perceived stress, and cognitive functioning. Life events were measured using the Lifetime Experiences Scale (LIFES) which covers 75 life experiences organized in eight domains. Results: A total of 95.9% of the participants reported more positive life events than negative throughout life. Participants reporting more positive experiences had lower scores in the depressive mood and perceived stress measures. At the domain-level of LIFES scale, more negative experiences in the Work and Health domains were associated with a depressed mood and more perceived stress. Significant positive associations were found between positive life experiences and most cognitive measures, after controlling for sex, education, age and depressive symptoms. Namely, more positive experiences at School, Leisure, and Living conditions were positively associated with better performance across cognitive tests. Discussion: This study adds important evidence on the association between of life events, both negative and positive experiences, on cognition and psychological well-being, providing a more balanced view of the field.

Short communication: Occurrence of methicillin-resistant Staphylococcus aureus and coagulase-negative staphylococci in dairy goat herds in Ohio, United States.

In light of the scarcity of information about the occurrence and epidemiology of methicillin-resistant Staphylococcus aureus (MRSA) and coagulase-negative staphylococci (MRCNS) in small ruminants in general, and particularly dairy goats, we launched this limited-scope study. The findings reported here show the detection of MRSA and MRCNS in goat milk and teat skin samples from dairy goat herds in the state of Ohio. A total of 120 milk samples and 120 teat-swab samples were collected from 5 farms. After conventional isolation and phenotypic characterization of the staphylococci colonies, bacterial isolates were tested by PCR assay targeting the genes nuc to identify Staphylococcus aureus and mecA to detect MRSA and MRCNS. The clonal complexes of MRSA isolates was also determined by multiloccus sequence typing. Fifteen (6.2%) positive S. aureus samples were found in this study: 9 from milk and 6 from teat skin samples. Four (2%) MRSA isolates were detected and, using multiloccus sequence typing genotyping, these were designated to clonal complexes CC133 (n = 2; milk samples) and CC5 (n = 2; teat skin). Three (1.25%) coagulase-negative staphylococci isolates from the teat skin also harbored the mecA gene. Although, the MRSA isolated from milk samples is not a typical human-associated lineage, the CC5 clone isolated from teat skin is a common and widespread clonal complex associated with humans, suggesting that this extramammary niche could be a relevant reservoir of methicillin-resistant staphylococci. Furthermore, the fact that 75% of MRSA were recovered from 1 farm showing poor hygiene practices strengthens the hypothesis that good hygiene practices could be useful to prevent persistence and spread of MRSA at a farm level.

Helminth Parasites of the Lizard Nothobachia ablephara (Gymnophthalmidae) in Caatinga Areas from the Sertão of Brazil.

The lizard Nothobachia ablephara is endemic to dune areas and sandy soils adjacent to the São Francisco River in semiarid northeastern Brazil. Forty-nine lizard specimens were collected in 2 Caatinga areas in the municipality of Petrolina in Pernambuco state. Three gastrointestinal helminth taxa were identified, the nematodes Parapharyngodon alvarengai and Physaloptera sp. and the cestode Oochoristica sp. Nothobachia ablephara showed low parasite richness, but high levels of infection by P. alvarengai. There were no significant differences between the parasitism rates of the 2 study areas or between male and female lizards. This is the first study on parasitism in N. ablephara, thereby increasing knowledge of parasite fauna that infect gymnophthalmid lizards in the Sertão of Brazil.

New additions to the herpetofauna of the Dois Irmãos State Park, an urban Atlantic Rainforest fragment in northeastern Brazil

The Atlantic Rainforest is the second largest forest block in the Neotropics, which originally comprised more than 150 million ha in highly heterogeneous environmental conditions. In this study, we updated the list of amphibians and reptiles in the Dois Irmãos State Park (PEDI), a conservation unit that is an Atlantic Rainforest remnant in Pernambuco State, northeastern Brazil. Active and passive surveys were carried out weekly, from June 2008 to April 2009, respectively by searching different forest microenvironments and by using pitfall traps. We recorded 34 species of amphibians belonging to 10 families and 27 species of reptiles belonging to 17 families. This study adds three species of amphibians and 18 species of reptiles to previous surveys of the herpetofauna at the PEDI. The PEDI comprises a richness equivalent to 49% of the anurans and 32% of the reptiles recorded in the Atlantic Rainforest in Pernambuco State. This area makes up the group of urban protected areas in which the local herpetofauna has been inventoried, as well as isolated areas in the metropolitan region of the municipality of Recife. Regarding these urban areas, the PEDI Reserve comprises 38.7% of the local richness, being considered a well-maintained remnant in an urban area. Thus, we highlight the need to invest in the conservation of urban forest fragments, given the significant richness that PEDI displays in relation to other extremely impoverished Atlantic Rainforest areas.

New additions to the herpetofauna of the Dois Irmãos State Park, an urban Atlantic Rainforest fragment in northeastern Brazil

The Atlantic Rainforest is the second largest forest block in the Neotropics, which originally comprised more than 150 million ha in highly heterogeneous environmental conditions. In this study, we updated the list of amphibians and reptiles in the Dois Irmãos State Park (PEDI), a conservation unit that is an Atlantic Rainforest remnant in Pernambuco State, northeastern Brazil. Active and passive surveys were carried out weekly, from June 2008 to April 2009, respectively by searching different forest microenvironments and by using pitfall traps. We recorded 34 species of amphibians belonging to 10 families and 27 species of reptiles belonging to 17 families. This study adds three species of amphibians and 18 species of reptiles to previous surveys of the herpetofauna at the PEDI. The PEDI comprises a richness equivalent to 49% of the anurans and 32% of the reptiles recorded in the Atlantic Rainforest in Pernambuco State. This area makes up the group of urban protected areas in which the local herpetofauna has been inventoried, as well as isolated areas in the metropolitan region of the municipality of Recife. Regarding these urban areas, the PEDI Reserve comprises 38.7% of the local richness, being considered a well-maintained remnant in an urban area. Thus, we highlight the need to invest in the conservation of urban forest fragments, given the significant richness that PEDI displays in relation to other extremely impoverished Atlantic Rainforest areas.

Potential distribution and conservation of the Colobosauroides carvalhoi Soares and Caramaschi, 1998: a rare and endemic lizard of Northeast Brazil / Distribuição potencial e conservação de Colobosauroides carvalhoi Soares and Caramaschi, 1998: um lagarto raro e endêmico do nordeste do Brasil

Abstract Ecological niche modeling has contributed to the investigation of the geographical distribution and conservation of rare or little recorded species. Therefore, we studied the known and potential distributions of Colobosauroides carvalhoi Soares and Caramaschi 1998 and discuss the implications for its conservation. Data were obtained by manual collections made in quarterly samplings in three different regions, considering the regions with occurrence records and surrounding areas. The known distribution was determined by occurrence records and literature data, and potential distribution was estimated with an ecological niche model by the MaxEnt algorithm. Twenty-five specimens were collected exclusively in forest formations of Caatinga and Caatinga-Cerrado. Our data corroborated the relative rarity of C. carvalhoi and reflected the biogeographical history of the group, where it is restricted to forest formations with milder environmental conditions. The occurrence records indicated new records of C. carvalhoi, but the known distribution value is compatible with a restricted distribution. The ecological niche model estimated few areas with environmental suitability for the species and corroborated the restricted and relict distribution patterns. Finally, the known and potential distribution values ​​were compatible with criteria for threatened species. These results suggest a worrisome scenario for C. carvalhoi conservation. However, the limited data about the species population do not allow the proper definition of its conservation status. Therefore, we suggest using potential distribution values with alternative criteria for redefining the conservation status of C. carvalhoi and the development of new studies that support a better assessment of its conservation aspects.

Resumo A modelagem ecológica de nicho vem contribuindo para investigar a distribuição geográfica e conservação de espécies raras ou com poucos registros de ocorrência. Neste sentido, investigou-se a distribuição conhecida e potencial da espécie Colobosauroides carvalhoi Soares & Caramaschi, 1998, discutindo as implicações para a conservação da espécie. Os dados foram coletados por meio de coletas manuais realizadas em amostragens trimestrais realizadas em três regiões distintas, considerando as regiões com registros de ocorrência conhecidos e áreas adjacentes. A distribuição conhecida foi determinada a partir dos novos registros de ocorrência e dados da literatura e a distribuição potencial estimada por meio de um modelo ecológico de nicho com uso do algoritmo MaxEnt. Vinte e cinco exemplares da espécie C. carvalhoi foram coletados exclusivamente em formações arbóreas da Caatinga e áreas de interface entre a Caatinga e o Cerrado. Estes resultados corroboram a relativa raridade da espécie e refletem a história biogeográfica do grupo, relacionada a ambientes florestados e que apresentam condições ambientais mais amenas. Os registros de ocorrência de C. carvalhoi indicam novos registros, entretanto, o valor de distribuição conhecida foi compatível com valores de distribuição restrita. O modelo ecológico de nicho estimou poucas áreas adequadas à ocorrência da espécie, corroborando um padrão de distribuição restrita e relictual. Por fim, os valores de distribuição conhecida e potencial estimados são compatíveis com valores definidos para espécies ameaçadas. Estes resultados sugerem um cenário preocupante para a conservação de C. carvalhoi. Entretanto, a atual limitação de dados populacionais dificulta uma adequada avaliação de seu status de conservação. Portanto, sugerimos o uso dos valores de distribuição potencial como critério alternativo para avaliar seu status de conservação até que novos estudos possam subsidiar uma melhor avaliação da conservação da espécie.

PAR-1 and PAR-2 Expression Is Enhanced in Inflamed Odontoblast Cells.

Protease-activated receptors (PARs) are G protein-coupled receptors, which are activated by proteolytical cleavage of the amino-terminus and act as sensors for extracellular proteases. We hypothesized that PAR-1 and PAR-2 can be modulated by inflammatory stimulus in human dental pulp cells. PAR-1 and PAR-2 gene expression in human pulp tissue and MDPC-23 cells were analyzed by quantitative polymerase chain reaction. Monoclonal PAR-1 and PAR-2 antibodies were used to investigate the cellular expression of these receptors using Western blot, flow cytometry, and confocal microscopy in MDPC-23 cells. Immunofluorescence assays of human intact and carious teeth were performed to assess the presence of PAR-1 and PAR-2 in the dentin-pulp complex. The results show for the first time that human odontoblasts and MDPC-23 cells constitutively express PAR-1 and PAR-2. PAR-2 activation increased significantly the messenger RNA expression of matrix metalloproteinase (MMP)-2, MMP-9, MMP-13, and MMP-14 in MDPC-23 cells ( P < 0.05), while the expression of these enzymes decreased significantly in the PAR-1 agonist group ( P < 0.05). The high-performance liquid chromatography and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry analysis showed the presence of MMP-13 activity cleaving PAR-1 at specific, noncanonical site TLDPRS42↓F43LL in human dental pulp tissues. Also, we detected a presence of a trypsin-like activity cleaving PAR-2 at canonical site SKGR20↓S21LIGRL in pulp tissues. Confocal microscopy analysis of human dentin-pulp complex showed intense positive staining of PAR-1 and PAR-2 in the odontoblast processes in dentinal tubules of carious teeth compared to intact ones. The present results support the hypothesis of activation of the upregulated PAR-1 and PAR-2 by endogenous proteases abundant during the inflammatory response in dentin-pulp complex.

Potential distribution and conservation of the Colobosauroides carvalhoi Soares and Caramaschi, 1998: a rare and endemic lizard of Northeast Brazil.

Ecological niche modeling has contributed to the investigation of the geographical distribution and conservation of rare or little recorded species. Therefore, we studied the known and potential distributions of Colobosauroides carvalhoi Soares and Caramaschi 1998 and discuss the implications for its conservation. Data were obtained by manual collections made in quarterly samplings in three different regions, considering the regions with occurrence records and surrounding areas. The known distribution was determined by occurrence records and literature data, and potential distribution was estimated with an ecological niche model by the MaxEnt algorithm. Twenty-five specimens were collected exclusively in forest formations of Caatinga and Caatinga-Cerrado. Our data corroborated the relative rarity of C. carvalhoi and reflected the biogeographical history of the group, where it is restricted to forest formations with milder environmental conditions. The occurrence records indicated new records of C. carvalhoi, but the known distribution value is compatible with a restricted distribution. The ecological niche model estimated few areas with environmental suitability for the species and corroborated the restricted and relict distribution patterns. Finally, the known and potential distribution values ​​were compatible with criteria for threatened species. These results suggest a worrisome scenario for C. carvalhoi conservation. However, the limited data about the species population do not allow the proper definition of its conservation status. Therefore, we suggest using potential distribution values with alternative criteria for redefining the conservation status of C. carvalhoi and the development of new studies that support a better assessment of its conservation aspects.

High pressure Raman spectra of monoglycine nitrate single crystal.

Single crystal of monoglycine nitrate has been studied by Raman spectroscopy under high pressures up to 5.5 GPa. The results show changes in lattice modes in the pressure ranges of 1.1-1.6 GPa and 4.0-4.6 GPa. The first change occurs with appearance of bands related to the lattice modes as well as discontinuity in the slope of dΩ/dP of these modes. Moreover, bands associated with the skeleton of glycine suggest that the molecule undergoes conformational modifications. The appearance of a strong band at 55 cm(-1) point to a second phase transition associated with the lattice modes, while the internal modes remain unchanged. These anomalies are probably due to rearrangement of hydrogen bonds. Additionally, decompression to ambient pressure shows that the phase transitions are reversible. Finally, the results show that the nitrate anions play an important role on the stability of the monoglycine nitrate crystal.

Atividade antimicrobiana e indutora de fitoalexinas do hidrolato de carqueja [Baccharis trimera (Less. ) DC. ] / Antimicrobial activity and phytoalexin induction of Baccharis trimera (Less. ) DC. hydrolate

Hidrolato é o líquido resultante da extração de óleo essencial de plantas aromáticas por arraste a vapor apresentando em sua composição importantes metabólitos do vegetal de origem. O objetivo deste trabalho foi avaliar a atividade indutora de fitoalexinas, bem como as propriedades antifúngica e antibacteriana do hidrolato de carqueja (Baccharis trimera). Foram testadas as concentrações de 1, 10, 25, 50, 75 e 100%. A atividade indutora de fitoalexinas foi avaliada em mesocótilos estiolados de sorgo e em cotilédones de soja. A atividade antifúngica foi avaliada sobre a germinação de esporos de Pseudocercospora vitis, Cercospora kaki e Hemileia vastatrix. A atividade antibacteriana foi avaliada sobre a multiplicação de Xanthomonas campestris pv. passiflorae, Erwinia carotovora e Bacilllus subtilis. O hidrolato não induziu a produção de fitoalexinas em soja, mas promoveu esta atividade em sorgo a partir da concentração de 50%. Atividade antibacteriana ocorreu para os três isolados a partir da concentração de 75%, com inibição de até 87,9% sobre B. subtilis. O hidrolato não mostrou atividade antifúngica.

Hydrolate is a product resulting from the extraction of a plant essential oil using steam distillation, which presents major metabolites of such plants in its composition. The objective of this work was to evaluate the phytoalexin induction and the antifungal and antibacterial activities of the Baccharis trimera hydrolate, in the concentrations of 1, 10, 25, 50, 75 and 100%. Phytoalexin induction was evaluated in etiolated sorghum mesocotyl and in soybean cotyledons. The antifungal activity was evaluated on the spore germination of Pseudocercospora vitis, Cercospora kaki and Hemileia vastatrix, while the antibacterial activity was evaluate on the Xanthomonas campestris pv. passiflorae, Erwinia carotovora and Bacillus subtilis multiplication. The hydrolate did not induce the phytoalexin synthesis in soybean, but it provided activity in sorghum in the concentration of 50% and above. Antibacterial activity occurred for the three isolates tested at the concentrations of 75 and 100%, with inhibition up to 87.9% for B. subtilis. The hydrolate showed no antifungal activity.

Statistical, computational and visualization methodologies to unveil gene primary structure features.

OBJECTIVES: Gene sequence features such as codon bias, codon context, and codon expansion (e.g. trinucleotide repeats) can be better understood at the genomic scale level by combining statistical methodologies with advanced computer algorithms and data visualization through sophisticated graphical interfaces. This paper presents the ANACONDA system, a bioinformatics application for gene primary structure analysis. METHODS: Codon usage tables using absolute metrics and software for multivariate analysis of codon and amino acid usage are available in public databases. However, they do not provide easy computational and statistical tools to carry out detailed gene primary structure analysis on a genomic scale. We propose the usage of several statistical methods--contingency table analysis, residual analysis, multivariate analysis (cluster analysis)--to analyze the codon bias under various aspects (degree of association, contexts and clustering). RESULTS: The developed solution is a software application that provides a user-guided analysis of codon sequences considering several contexts and codon usage on a genomic scale. The utilization of this tool in our molecular biology laboratory is focused on particular genomes, especially those from Saccharomyces cerevisiae, Candida albicans and Escherichia coli. In order to illustrate the applicability and output layouts of the software these species are herein used as examples. CONCLUSIONS: The statistical tools incorporated in the system are allowing to obtain global views of important sequence features. It is expected that the results obtained will permit identification of general rules that govern codon context and codon usage in any genome. Additionally, identification of genes containing expanded codons that arise as a consequence of erroneous DNA replication events will permit uncovering new genes associated with human disease.

A serine proteinase inhibitor isolated from Tamarindus indica seeds and its effects on the release of human neutrophil elastase.

Proteinaceous inhibitors with high inhibitory activities against human neutrophil elastase (HNE) were found in seeds of the Tamarind tree (Tamarindus indica). A serine proteinase inhibitor denoted PG50 was purified using ammonium sulphate and acetone precipitation followed by Sephacryl S-300 and Sephadex G-50 gel filtration chromatographies. Inhibitor PG50 showed a Mr of 14.9 K on Sephadex G-50 calibrated column and a Mr of 11.6 kDa on sodium dodecyl sulfate-polyacrylamide gel electrophoresis. PG50 had selective activity while cysteine proteinases (papain and bromelain) and serine proteinases (porcine pancreatic elastase and bovine chymotrypsin) were not inhibited, it was strongly effective against serine proteinases such as bovine trypsin and isolated human neutrophil elastase. The IC50 value was determined to be 55.96 microg.mL-1. PG50 showed neither cytotoxic nor haemolytic activity on human blood cells. After pre-incubation of PG50 with cytochalasin B, the exocytosis of elastase was initiated using PAF and fMLP. PG50 exhibited different inhibition on elastase release by PAF, at 44.6% and on release by fMLP, at 28.4%. These results showed that PG50 preferentially affected elastase release by PAF stimuli and this may indicate selective inhibition on PAF receptors.

[Necrotizing fasciitis after varicella]. / Fasceíte necrosante pós varicela.

Necrotizing fasciitis is a rare and severe infection characterised by extremely rapid progressive involvement of the superficial fascias and deep dermal layers of the skin, with resultant vasculitis and necrosis. The authors present three clinical cases of necrotizing fasciitis; all three patients previously had varicella rash, rapid progressive spreading erythema with severe pain and toxic shock syndrome. Two patients had positive cultures of b-haemolytic streptococcus. Early stage differential diagnosis with celulitis, aggressive antibiotic treatment and pediatric intensive care support are essential. However, the main therapy is early extensive surgical approach involving all indurate areas, down to and including the muscle fascia.

[Hospital nursing service--introducing this silent giant]. / O serviço de enfermagem hospitalar-apresentando este gigante silencioso.

This article shows the importance of the nursing service in the health organizations. The metaphor "giant" will be used to describe the extent of this service, and the term "silent" will be used to refer to the little acknowledgment the nursing service receives from the community. The extent and complexity of the nursing assistance is vital for the effectiveness of the processes of health care, however its structure and organization is unknown by the community. The nursing service congregates a great number of personnel with different levels of education. The planning, organization, structure and operation of this service follow the principles of the General Theory of Administration. Knowledge from this area has also been used to help health institutions to achieve its goals and objectives. This study also approaches the client and the quality of health assistance, pointing out the need of reexamining the administrative model adopted and looking forward to systemic alternatives.

Trance surgery in Brazil.

This report presents the results of fieldwork in Brazil on healer-mediums who perform crude forms of surgery, often employing sharp instruments. We found that these healer-mediums were in a hyperaroused brain state while they were engaged in behaviors commonly described in the anthropology literature as "possession trance"; therefore, this practice is termed "trance surgery" in this report. The research was conducted at widely scattered sites throughout Brazil. We observed several thousand patients being treated by 9 trance surgeons and videotaped several hundred of these cases. In addition to background information and our own observational material, this paper includes 2 medical case reports, physiological data gathered from healers and patients, and results of a pathologist's examination of a surgically excised tumor. Topographic brain mapping revealed increased brain activity (36-44 Hz) when healer-mediums were engaged in trance behaviors, compared to resting baseline conditions at midline scalp locations (Cz, P < .009 and Pz, P < .004; both matched t tests). These results suggest the presence of a hyperaroused brain state associated with the trance behaviors of the healers. We believe that such a state is required for this unusual practice, but other factors may also be involved. In contrast, a small sample of patients monitored during possession trance surgical procedures revealed no high-frequency brain activity; instead, there were indications of cortical quieting, suggesting relaxation, despite the absence of anesthesia. Pathohistological examination of a tumor excised from a patient in our presence revealed a human fibroadenoma. We conclude that these practices are usually benign and that pain is often absent, despite the lack of sterile procedures and anesthesia. Although during the period of our investigation we were informed anecdotally of 3 cases involving serious complications or death, we personally observed no cases of shock, hemorrhage, or death. The cases presented in this paper, as well as others we have followed, suggest that serious illnesses, not likely to improve without treatment, may do so after trance surgery procedures are performed. If the major benefit of trance surgery is to initiate self-healing processes, it would have to do so in powerful ways, which possibly can be elucidated with positron emission tomography and functional magnetic resonance imaging scans. Positive findings would be helpful in understanding large-scale healing effects and may lead to new treatment protocols.

Organic compounds in the extrapalial fluid and haemolymph of Anodonta cygnea (L.) with emphasis on the seasonal biomineralization process.

Bivalve mollusks, such as the freshwater mussel Anodonta cygnea, show seasonal changes in calcification. This cycle of calcification must either be a cause or a consequence for seasonal fluctuations in the organic composition of the animal's fluids, haemolymph and extrapallial fluid, the liquid media for biomineralization. We monitored the fluids of A. cygnea, throughout a 1-year cycle, for the presence of organic constituents, known to be important for biomineralization, such as proteins, glycosaminoglycans (GAGs) and hexosamines. Proteins were subjected to further study, namely through the total amino acid determination and fraction separation by agarose gel electrophoresis. GAG levels were fairly constant throughout the year, with a maximum concentration in July and a minimum in January, a feature also detected for glucosamine, although with higher fluctuations. Proteins showed highly increased concentrations during June and July, both in total amounts and individual fractions. All fractions showed similar trends throughout the year, with lowest general levels in October, the starting month of a period when some fractions were not detectable at all. All fractions ended this low period in May, when a sometimes-important increase could be detected. As to the total amino acid composition of the fluids, the general trend followed that of proteins, except for ornithine (Orn), a non-proteic amino acid. The overall fluctuations detected in the biological fluids of A. cygnea suggest that the main variation related to the calcification cycle must be quantitative, since no different compounds appear in specific periods, to achieve also specific results.

The action of Cd, Cu, Cr, Zn, and Pb on fluid composition of Anodonta cygnea (L.): organic components.

The heavy metals, Cd, Cu, Cr, Zn, and Pb, were used to incubate healthy specimens of the freshwater mussel species, Anodonta cygnea. Afterwards, their biological fluids, either haemolymph or extrapallial fluid were analyzed for the presence of several organic constituents, known to be important for biomineralization, such as proteins, glycosaminoglycans (GAGs) and glucosamine. Proteins were subjected to further study, namely through the total amino acid determination after acid hydrolysis. The most disturbing pollutants tested seem to be Pb, Zn, and Cr, which caused highly decreased overall compositions, namely with respect to protein, and glucosamine, in comparison to the control group. This suggests that this group contributes to a decrease of the metabolic activity, and thus mineralization, in the exposed animals.

[Stress related to administrative tasks in nursing]. / O estresse na atividade gerencial do enfermeiro.

According to several studies, nursing, especially in hospital settings, is one of the most stressful professions. The objective of this study was to identify the sources of stress related to the administrative tasks of nurses working in a hospital, as well as the main health changes that stress caused these professionals. The quantitative survey was carried out in 1996 with a sample of 207 nurses at a university hospital in the city of Porto Alegre, in the state of Rio Grande do Sul, Brazil. A questionnaire was used to collect data on stress sources and symptoms. The questionnaire also gathered demographic data, as well as information on the nurses' feelings about their working conditions. The average age of the study participants was 35.8 years, and the average time working at the hospital was 8.5 years. Among participants, 48% were considered to be stressed. Work overload was the stress source that best predicted relative risk of stress (6.1). In terms of stress symptoms, the most commonly reported ones were cardiovascular changes. However, gastrointestinal changes were related to a higher risk of stress (5.3). Managing other staff was the stress source that had the greatest number of significant correlations with stress symptoms. On the other hand, immunologic changes were the symptoms that had the highest correlation with stress sources. Our results suggest that stress related to administrative tasks in nursing may trigger changes in nurses' health.