Global warming and hepatotoxin production by cyanobacteria: what can we learn from experiments?

Global temperature is expected to rise throughout this century, and blooms of cyanobacteria in lakes and estuaries are predicted to increase with the current level of global warming. The potential environmental, economic and sanitation repercussions of these blooms have attracted considerable attention among the world’s scientific communities, water management agencies and general public. Of particular concern is the worldwide occurrence of hepatotoxic cyanobacteria posing a serious threat to global public health. Here, we highlight plausible effects of global warming on physiological and molecular changes in these cyanobacteria and resulting effects on hepatotoxin production. We also emphasize the importance of understanding the natural biological function(s) of hepatotoxins, various mechanisms governing their synthesis, and climate-driven changes in food-web interactions, if we are to predict consequences of the current and projected levels of global warming for production and accumulation of hepatotoxins in aquatic ecosystems.     

Application of Coffee Silverskin in cosmetic formulations: physical/antioxidant stability studies and cytotoxicity effects

Context: Currently, there is an increasing interest of cosmetic industry on natural extracts. The inclusion of antioxidants in topical formulations can contribute to minimize oxidative stress in the skin, which has been associated with aging. Also, questions of sustainability are leading to the study of new cosmetic ingredients obtained from food by-products. Coffee Silverskin (CS) is a food by-product with established antioxidant activity that has not yet been incorporated into a topical formulation.

Objective: The aim of this study was to evaluate the physical and microbiological stabilities and antioxidant activity of a hand cream formulation containing 2.5% (w/w) of CS extract upon production and after 6 months of shelf-life and in vitro safety/cytotoxicity on skin cell lines after production.

Materials and methods: The in vitro cytotoxicity was evaluated with MTS and LDH assays, at different concentrations, in HaCaT and HFF-1 cells. Formulations were stored at 25?°C/65% RH and 40?°C/75% RH. Physical, microbiological, and antioxidant stabilities were evaluated by centrifugation, viscosity, total colony count, DPPH and total phenolic content (TPC).

Results: The hand cream containing 2.5% (w/w) of CS extract showed stable physical characteristics independently of the storage conditions. The DPPH activity and TPC of the CS formulation were significantly higher compared with those of the base formulation. However, during storage, the antioxidant activity decreases slightly. Microbiological quality was also confirmed. No cytotoxic effects were observed.

Conclusion: It is possible to suggest that this formulation is stable under extreme conditions and safe for topical use.     

The influence of Elfreda Chatman’s theories: a citation context analysis

The range of theoretical frameworks currently being used by researchers into information behaviour is abundant and diverse. We need to examine thoroughly the contribution of theories and models to further research, as this would help to improve future investigations in the field. This paper adopts this approach, by thoroughly examining the influence that Elfreda Chatman’s three middle-range theories have had on subsequent research. A citation context analysis was carried out on the basis of those received by Information poverty theory, life in the round theory and normative behaviour theory. Analysis covered the year of publication, the type of work and the subject-matter of the citing documents. The cites in context or theoretical incidents were analysed for frequency of citation in citing documents, the content of Chatman’s work being cited, the context co-citation analysis, the citation style and the citation location. The analysis of citation in context has allowed us to draw a distinction between the author and her work, while verifying that not all cites are the same. These differences reflect the unequal relevance of these theories to subsequent research.

     

Removal of Immiscible Contaminants from Sandy Soils Monitored by Means of Dielectric Measurements

The main objective of this paper is to explore the potential application of electromagnetic waves to evaluate the effect of contaminant removal in granular soils. Thus, various specimens of saturated silica sand were prepared using paraffin oil and lubricant oil as contaminants. Four flushing fluids were used to remove the contaminants from sand columns: Deionized water, water-detergent, water-detergent-alcohol solution, and water vapor. Dielectric permittivity was measured at different stages of the removal process at the frequency from 20?MHz?to?1.3?GHz. The measured permittivity was compared with that determined for clean and fully contaminated specimens. A theoretical mixture formula was calibrated and implemented to estimate the volume fraction of contaminant present in the pore fluid. It is concluded in this work that dielectric parameters reflect the contamination level of the soil for the nonpolar organic compounds used here. Measurement of permittivity allows us to determine that the inclusion of alcohol and detergent in the displacing fluid improved the removal efficiency. However, water vapor was the most efficient removal agent.     

Second primitive malignant tumour in patients with gynaecological cancer

OBJECTIVE: The purpose of this study was to characterise the occurrence of multiple primitive gynaecological malignant neoplasias, restricted to the genital tract and breast or associated with other organs, and to detect which types of association are most frequent concerning location, histology and staging. POPULATION AND METHODS: The records of patients with gynaecological cancer at the Portuguese Institute of Oncology--Lisbon Centre, between 1986 and 1993 were used in this study. RESULTS: Of the 10,746 women with gynaecological cancer, 91 (0.8%) were found to have a second primitive malignant neoplasia. Of these neoplasias, 64% (58 cases) were also located at a gynaecological site. The most frequent associations were endometrium/breast (13 cases), bilateral breast (12 cases) and ovary/endometrium (11 cases). The majority of primitive multiple gynaecological tumours were synchronous. Regarding gynaecological cancer and non-gynaecological cancer, in 28 cases (31%), the most common non-gynaecological location was the colon/rectum. Five patients had triple tumours. CONCLUSION: Although these situations are relatively rare the possibility of multiple primitive cancers should be considered with the presence of malignant tumours in two or more organs. This distinction between multiple primitive or metastatic cancers could be important for treatment as well as prognosis.     

Antioxidant Systems from Pepper (Capsicum annuum L.): Involvement in the Response to Temperature Changes in Ripe Fruits

Sweet pepper is susceptible to changes in the environmental conditions, especially temperatures below 15 °C. In this work, two sets of pepper fruits (Capsicum annuum L.) which underwent distinct temperature profiles in planta were investigated. Accordingly, two harvesting times corresponding to each set were established: Harvest 1, whose fruits developed and ripened at 14.9 °C as average temperature; and Harvest 2, with average temperature of 12.4 °C. The oxidative metabolism was analyzed in all fruits. Although total ascorbate content did not vary between Harvests, a shift from the reduced to the oxidized form (dehydroascorbate), accompanied by a higher ascorbate peroxidase activity, was observed in Harvest 2 with respect to Harvest 1. Moreover, a decrease of the ascorbate-generating enzymatic system, the γ-galactono-lactone dehydrogenase, was found at Harvest 2. The activity values of the NADP-dependent dehydrogenases analyzed seem to indicate that a lower NADPH synthesis may occur in fruits which underwent lower temperature conditions. In spite of the important changes observed in the oxidative metabolism in fruits subjected to lower temperature, no oxidative stress appears to occur, as indicated by the lipid peroxidation and protein oxidation profiles. Thus, the antioxidative systems of pepper fruits seem to be involved in the response against temperature changes.     

Pancreatic lipase activity in emulsions containing seed meals: Effect of extrusion

The effect of extrusion of soybean (Glycine max), yellow lupin (Lupinus luteus), and linseed (Linum usitatissimum) on the activity of porcine pancreatic lipase (PPL) was evaluated through pH‐Stat methodology with tributyrin emulsions in which the seed meals [extruded (E) and non‐extruded (NE)] were dispersed. The seed meals affected PPL activity in a concentration‐dependent fashion; at 2.3 mg/mL the meals reduced PPL activity (11.7–45.0% reduction) while the opposite was true (3.1–28.0% increase) at 6.8 mg/mL. PPL activity in the assays containing E‐lupin, E‐soybean and E‐linseed meals at 2.3 mg/mL was 109.7 and 11.3% higher and 25.5% lower than the activity in the emulsions containing the NE‐meals, respectively. The differences between the PPL activity in emulsions containing the extruded and NE‐meals could be due to changes in the emulsifying properties of the meals after extrusion; extrusion increased (10.2%) the emulsification capacity of lupin meal and for linseed meal this property was reduced (9.2%). In spite of the low PPL activity at low meal concentrations, the percentage of free fatty acids released after 30 min was similar to the theoretical maximum (66.6%) with two exceptions – NE‐soybean meal (59.5 ± 2.7%) and E‐linseed meal (57.9 ± 1.2%). Practical applications: Feed and food industries use plant protein sources that contain inhibitors of digestive enzymes. Various proteases inhibitors are inactivated during extrusion being less known the effect of extrusion on lipase inhibitors. Reduction of lypolysis rate, carried out mainly by pancreatic lipase in human and other animals, could influence feed and food consumption because satiety is controlled – at least in part – by undigested lipids. Our results show that extrusion can be used to reduce the inhibitory activity of lupin and soybean on PPL. On the other hand, extrusion of linseed increased the negative effect of this meal on PPL activity effect that could have applications in the development of food and ingredients for weight control.     

Acidity and DAG Content of Olive Oils Recently Produced on the Island of Mallorca

In this study, the quality characteristics, i.e., the acidity and acylglycerols, of currently produced Mallorcan oil was analyzed by titration and gas-chromatographic technique, respectively, in approximately 400 samples of monovarietal olive oil made from three genetic varieties (Arbequina, Empeltre, and Picual) on the island of Mallorca during the 2003/2004 and 2005/2006 seasons, and the differences in the compositions were discussed. Composition analysis showed that free fatty acids (FFAs) and DAGs were produced mainly by hydrolysis of triacylglycerols (TAGs). Fruit storage tests revealed that hydrolysis occurred during storage of olive fruits. The DAG content was higher in oil with higher acidity, but the maximal DAG content was only about 10 with 30% acidity, and the primary isomer found in Mallorcan oil was 1,3-DAG. However, the chiral-chromatographic study on the ratio of sn-1,2-DAG to the sum of sn-1,2-DAG and sn-2,3-DAG in a slightly hydrolyzed oil sample indicated that Empeltre and Picual fruits possess an sn-3-enantioselective lipase that leads to accumulation of sn-1,2-DAG. In currently produced Mallorcan oil, significant isomerization appears to occur and hydrolysis of the resulting 1,3-DAGs seems to lessen DAG accumulation.     

Predictive accuracy of body mass index in estimating body fatness measured by bioelectrical impedance

The aim of this study was to determinate the performance of body mass index (BMI) for the diagnosis of obesity and as a predictor of body fatness in adult Chilean subjects. We conducted a study in 433 women (18-73 years old; BMI: 19.7 to 69.7 kg/m2) and 264 men (18-83 y.; BMI: 19.1 to 54.8 kg/m2). Bioelectrical resistance was measured by impedance method and fat mass percent (FM%) was calculated by fatness-specific equations developed by Segal et al. Obesity was defined as a BMI of at least 30 kg/m2. Increased fatness was defined by the FM% cut-off points of at least 25% for men and at least 30% for women. Sixty-four percent of women and 23.6% of men with BMI below 30 kg/m2 had FM% higher than 30% and 25%, respectively. A value of BMI of 26 kg/m2 in women and 30 kg/m2 in men had the best agreement to the cut-off points of fatness according to sensitivity vs. specificity analysis The following equations were developed to predict individual fatness: women FM% = 0.96 x BMI + 0.154 x age + 1.44 (r2 = 0.75; standard error 3.8%); men FM% = 0.99 x BMI + 0.141 x age - 9.914 (r2 = 0.66; standard error 4.4%). Differences between measured and predicted FM% presented a wide variation, with a range of +/- 2 sd of 7.5% in women and 8.8% in men. The commonly used value of BMI 330 kg/m2 as a cut-off point for obesity does not have adequate sensitivity and specificity for the screening of increased fatness subjects, specially in women. In this study BMI shows a low reliability as a predictor of individual body fatness, particularly in men and in subjects with a BMI below 30 kg/m2.