Do different degrees of human activity affect the diet of Brazilian silverside Atherinella brasiliensis?

The aim of the present study was to test whether different degrees of human activity affect the diet of the Brazilian silverside Atherinella brasiliensis in two tropical estuaries. Fish were collected along the salinity gradient of two Brazilian estuaries, the heavily impacted Paraiba Estuary and the less impacted Mamanguape Estuary, in the dry and wet seasons. The findings confirm that A. brasiliensis has generalist feeding habits and is able to change its diet under different environmental conditions. The results indicate clear spatial (i.e. along the estuarine gradient) changes in diet composition in both estuaries, but diet was also influenced by the degree of anthropogenic disturbance. During the wet season in the nutrient enriched Paraiba Estuary, when human activity was higher, the diet of A. brasiliensis was poorer and dominated by few dietary items, reflecting the potential impoverishment of prey items in this heavily disturbed system. The specimens collected in the most affected estuary also had a greater frequency of micro‐plastics and parasites in their stomachs, reflecting the greater degree of human disturbance in the estuary. The present findings suggest that the diet of A. brasiliensis could be a useful indicator of changes in the ecological quality of these and other tropical estuaries of the western Atlantic Ocean.     

Diet and Feeding Behavior of <Emphasis Type="Italic">Leontopithecus chrysomelas</Emphasis> (Callitrichidae) in Degraded Areas of the Atlantic Forest of South-Bahia,Brazil

Habitat disturbance alters plant diversity and food resource availability, affecting the ecology, and ultimately the survival and reproduction, of species depending on those plants. Studies in degraded areas serve to improve our understanding of the consequences of habitat modification for endangered species and to guide conservation actions. We studied diet composition, monthly variation in feeding behavior and fruit feeding time, and dietary diversity in two golden-headed lion tamarin (Leontopithecus chrysomelas) groups ranging in a degraded area of the Atlantic Forest in South-Bahia, Brazil, over a 12-mo period. We recorded feeding behavior and food items consumed through continuous observations and focal animal sampling, and performed dietary analyses on samples from consumed fruits. Substrate manipulation to search for animal prey was the feeding activity most frequently observed, followed by fruit consumption. We observed nectar drinking and exudate feeding at low frequencies from April through July. Bromeliads were the principal foraging substrate. We observed the use of 114 plant species, confirming the large dietary diversity reported for the species. Individual trees from the family Melastomataceae, common in degraded forests, accounted for the highest visiting frequencies (40%). Fruit availability was the main factor explaining variation in monthly fruit feeding time, despite the absence of climatic seasonality. Nutritional or energetic characteristics did not affect fruit choice. Differences in floristic composition appear to be a major determinant of the species’ diet in different study areas. Regional forest restoration programs should consider including advanced forest species, to improve both forest quality and animal mobility between fragments.     

Antimicrobial resistance and class I integrons in Salmonella enterica isolates from wild boars and Bísaro pigs

The antibiotic resistance phenotype and genotype and the integron type were characterized in 58 Salmonella enterica isolates recovered from Bísaro pigs and wild boars (20 S. Typhimurium, 17 S. Rissen, 14 S. Enteritidis and 7 S. Havana). Most S. Typhimurium isolates (15/20 of Bísaro pigs and wild boars) showed ampicillin, chloramphenicol, streptomycin, tetracycline, sulfonamide, and amoxicillin-clavulanic acid resistances. Of the 17 S. Rissen isolates of both origins, 13 were resistant to ampicillin, tetracycline and trimethoprim-sulfamethoxazole. Among the S. Enteritidis isolates of Bísaro pigs, eight were nalidixic acid-resistant and three were sulfonamide-resistant. The tet(A) or tet(G) genes were detected in most tetracycline-resistant isolates. The intI1 gene was identified in 72.5% of S. enterica isolates in which the conserved region 3' of class 1 integrons (qacEΔ1+sul1) was also amplified, whereas none had the intI2 gene. The dfrA12+orfF+aadA2 gene cassette arrangement was found in the variable region of class 1 integrons in 14 S. Rissen isolates. Fifteen S. Typhimurium isolates had two integrons with variable regions of 1000 and 1200 bp that harbored the aadA2 and blaPSE-1 gene cassettes, respectively. In these isolates the floR and tet(G) genes were also amplified, indicative of the genomic island 1 (SGI1). Salmonella Typhimurium and S. Rissen of animal origin frequently show a multi-antimicrobial resistant phenotype, which may have implications in public health.     

Artefacts induced on <Emphasis Type="Italic">c</Emphasis>-type haem proteins by electrode surfaces

In this work it is demonstrated that the characterization of c-type haem containing proteins by electrochemical techniques needs to be cautiously performed when using pyrolytic graphite electrodes. An altered form of the cytochromes, which has a redox potential 300 mV lower than that of the native state and displays peroxidatic activity, can be induced by interaction with the pyrolytic graphite electrode. Proper control experiments need to be performed, as altered conformations of the enzymes containing c-type haems can show activity towards the enzyme substrate. The work was focused on the study of the activation mechanism and catalytic activity of cytochrome c peroxidase from Paracoccus pantotrophus. The results could only be interpreted with the assignment of the observed non-turnover and catalytic signals to a non-native conformation state of the electron-transferring haem. The same phenomenon was detected for Met–His monohaem cytochromes (mitochondrial cytochrome c and Desulfovibrio vulgaris cytochrome c-553), as well as for the bis-His multihaem cytochrome c ₃ from Desulfovibrio gigas, showing that this effect is independent of the axial coordination of the c-type haem protein. Thus, the interpretation of electrochemical signals of c-type (multi)haem proteins at pyrolytic graphite electrodes must be carefully performed, to avoid misassignment of the signals and incorrect interpretation of catalytic intermediates.     

Relaxation of reproductive suppression in non-breeding female naked mole-rats, Heterocephalus glaber

Ninety-four non-reproductive female naked mole-rats, from seven colonies, were studied in terms of vaginal perforation, vaginal smears and urinary concentrations of oestradiol-17β and progesterone in relation to the time of parturition of the breeding female, the queen. The study concentrated mainly on the period from nine days prepartum to 13 days postpartum of 12 births. Sixty-eight percent ( n = 253) of the non-reproductive females had detectable urinary concentrations of oestradiol-17β and many of these had perforated vaginas throughout the study period. These females showed a significantly increased urinary concentration of oestradiol six days prior to parturition of the queen. In females with undetectable concentrations of oestradiol-17β, the proportion with perforated vaginas increased from six days prepartum (54%) to reach a peak on the day of parturition (92%) of the queen. Urinary progesterone-concentrations were 0.7nmol/mmol creatinine at some stage in the study period in 90% of the females and scattered short peaks or spikes were experienced by all these females, but without synchronization between the females in a colony and without any detectable correlation with the time of parturition of the queen. Maximal concentrations in some females were comparable to the values in cycling breeding females during the luteal phase, but were of a much shorter duration than in breeding females. Vaginal smears did not show clear cyclic patterns.     

Galactodendritic Phthalocyanine Targets Carbohydrate-Binding Proteins Enhancing Photodynamic Therapy

Photosensitizers (PSs) are of crucial importance in the effectiveness of photodynamic therapy (PDT) for cancer. Due to their high reactive oxygen species production and strong absorption in the wavelength range between 650 and 850 nm, where tissue light penetration is rather high, phthalocyanines (Pcs) have been studied as PSs of excellence. In this work, we report the evaluation of a phthalocyanine surrounded by a carbohydrate shell of sixteen galactose units distributed in a dendritic manner (PcGal₁₆) as a new and efficient third generation PSs for PDT against two bladder cancer cell lines, HT-1376 and UM-UC-3. Here, we define the role of galacto-dendritic units in promoting the uptake of a Pc through interaction with GLUT1 and galectin-1. The photoactivation of PcGal₁₆ induces cell death by generating oxidative stress. Although PDT with PcGal₁₆ induces an increase on the activity of antioxidant enzymes immediately after PDT, bladder cancer cells are unable to recover from the PDT-induced damage effects for at least 72 h after treatment. PcGal₁₆ co-localization with galectin-1 and GLUT1 and/or generation of oxidative stress after PcGal₁₆ photoactivation induces changes in the levels of these proteins. Knockdown of galectin-1 and GLUT1, via small interfering RNA (siRNA), in bladder cancer cells decreases intracellular uptake and phototoxicity of PcGal₁₆. The results reported herein show PcGal₁₆ as a promising therapeutic agent for the treatment of bladder cancer, which is the fifth most common type of cancer with the highest rate of recurrence of any cancer.     

Pelagic rotifers of Lake Glubokoe from 1897 to 1984

After alteration in the pattern of drainage of run-off from the surrounding swamps and changes in the colour and transparency of the Lake Glubokoe water, the previously epilimnial Trichocerca similis, Conochilus unicornis and Keratella cochlearis showed a shift of their maximum numbers to deeper layers. Pompholyx sp. and Trichocerca capucina, which are regarded as indicators of eutrophic waters, have disappeared from the pelagic zone of the lake and Conochilus hippocrepis, Synchaeta pectinata, Gastropus stylifer, Asplanchna herricki, Ascomorpha ecaudis, Ascomorpha saltans, Euchlanis dilatata and Trichocerca porcellus have made their appearance. Most of the new species are considered to be indicators of oligotrophic conditions. However the total density of pelagic rotifers remained at the same level. Apparently the establishment of the new species of rotifers was possible due to some ‘rarefaction’ of the epilimnion, the disappearance of predaceous Mesocyclops leuckarti and the invasion of the pelagic zone by Peridinium cinctum.     

Comparison of Unplanned Intensive Care Unit Readmission Scores: A Prospective Cohort Study

PurposeEarly discharge from the intensive care unit (ICU) may constitute a strategy of resource consumption optimization; however, unplanned readmission of hospitalized patients to an ICU is associated with a worse outcome. We aimed to compare the effectiveness of the Stability and Workload Index for Transfer score (SWIFT), Sequential Organ Failure Assessment score (SOFA) and simplified Therapeutic Intervention Scoring System (TISS-28) in predicting unplanned ICU readmission or unexpected death in the first 48 hours after discharge from the ICU.MethodsWe conducted a prospective cohort study in a single tertiary hospital in southern Brazil. All adult patients admitted to the ICU for more than 24 hours from January 2008 to December 2009 were evaluated. SWIFT, SOFA and TISS-28 scores were calculated on the day of discharge from the ICU. A stepwise logistic regression was conducted to evaluate the effectiveness of these scores in predicting unplanned ICU readmission or unexpected death in the first 48 hours after discharge from the ICU. Moreover, we conducted a direct accuracy comparison among SWIFT, SOFA and TISS-28 scores.ResultsA total of 1,277 patients were discharged from the ICU during the study period. The rate of unplanned ICU readmission or unexpected death in the first 48 hours after discharge from the ICU was 15% (192 patients). In the multivariate analysis, age (P = 0.001), length of ICU stay (P = 0.01), cirrhosis (P = 0.03), SWIFT (P = 0.001), SOFA (P = 0.01) and TISS-28 (P<0.001) constituted predictors of unplanned ICU readmission or unexpected death. The SWIFT, SOFA and TISS-28 scores showed similar predictive accuracy (AUC values were 0.66, 0.65 and 0.74, respectively; P = 0.58).ConclusionsSWIFT, SOFA and TISS-28 on the day of discharge from the ICU have only moderate accuracy in predicting ICU readmission or death. The present study did not find any differences in accuracy among the three scores.