Characterization and application of a biosurfactant isolated from Candida utilis in salad dressings.

This study aimed at characterizing a biosurfactant from Candida utilis, and use it in the preparation of salad dressings. The biosurfactant was produced in mineral medium supplemented with 6% glucose and 6% waste frying canola oil. The crude biosurfactant was then tested for stability in different conditions of pH, salt concentration, heating time and temperature. The critical micelle dilution, chemical composition, and structural analysis were determined. The compound was resistant to extreme conditions and presented stable surface tension and emulsification activity in alkaline pH and was characterized as a carbohydrate-lipid-protein complex showing the best formulation and consistency at 0.7% (w/v) with guar gum indicating potential applicability in food emulsions.

Toxic effects of two essential oils and their constituents on the mealworm beetle, Tenebrio molitor.

The study identified insecticidal effects from the cinnamon and clove essential oils in Tenebrio molitor L. (Coleoptera: Tenebrionidae). The lethal concentrations (LC50 and LC90), lethal time, and repellent effect on larvae, pupae, and adults of T. molitor after exposure to six concentrations of each essential oil and toxic compounds were evaluated. The chemical composition of the cinnamon oil was also determined and primary compounds were eugenol (10.19%), trans-3-caren-2-ol (9.92%), benzyl benzoate (9.68%), caryophyllene (9.05%), eugenyl acetate (7.47%), α-phellandrene (7.18%), and α-pinene (6.92%). In clove essential oil, the primary compounds were eugenol (26.64%), caryophyllene (23.73%), caryophyllene oxide (17.74%), 2-propenoic acid (11.84%), α-humulene (10.48%), γ-cadinene (4.85%), and humulene oxide (4.69%). Cinnamon and clove essential oils were toxic to T. molitor. In toxic chemical compounds, eugenol have stronger contact toxicity in larvae, pupae, and adult than caryophyllene oxide, followed by α-pinene, α-phellandrene, and α-humulene. In general, the two essential oils were toxic and repellent to adult T. molitor. Cinnamon and clove essential oils and their compounds caused higher mortality and repellency on T. molitor and, therefore, have the potential for integrated management programs of this insect.

Spent Pot Liner (SPL) induced DNA damage and nuclear alterations in root tip cells of Allium cepa as a consequence of programmed cell death.

There are various toxic effects of environmental pollutants, including apoptosis and carcinogenesis. Spent Pot Liner (SPL) is solid waste from the aluminum industry. It has a highly variable composition, including cyanide, fluoride, organics and metals. Preliminary characterizations of the effect of SPL on Allium cepa show the presence of condensed nuclei. Thus, the aim of this study was to analyze the toxic effect of SPL in A. cepa root meristem in the context of programmed cell death (PCD). A lot of specific features of this process such as DNA fragmentation, condensed chromatin, spherical nuclei and the formation of apoptotic-like bodies were observed in root meristem after SPL treatment. Root meristem treated with SPL 25% solution exhibited an alteration in antioxidant enzyme activities; a reduction in NCR as a consequence of high percentage of condensed nuclei; DNA fragmentation, detected by electrophoresis and TUNEL assay; cytoplasm vacuolization and also a disturbance in root morphology. These features are associated with programmed cell death (PCD) under abiotic stress. Therefore, these data show that SPL induces apoptosis-like PCD in root meristem cells of A. cepa.

Cytogenetic alterations induced by SPL (spent potliners) in meristematic cells of plant bioassays.

Spent potliners (SPL) is solid waste generated by the aluminum industry during the manufacture of aluminum metal. Information on the cytotoxicity effect of SPL is necessary to facilitate understanding of their action on organisms and to subsidize environmentally correct solutions. Thus, the aim of the present investigation is to compare the effect of SPL on meristematic cells of Allium cepa and Zea mays and also to discuss the mechanisms of SPL cytotoxicity involved. A strong inhibition on root growth in higher SPL concentrations has been observed in both A. cepa and Z. mays. For cytogenetic analysis, the results showed a reduction of mitotic index and increase of different abnormalities as the SPL concentration increased. We observed bridges, chromosome fragments, stickiness, multipolar anaphase, later segregation and cell death. In general, it was possible to observe an increase of different abnormalities as the SPL concentration increased. It is obvious from the results of the present investigation that SPL is cytotoxic on meristematic cells of plant tests (A. cepa and Z. mays).

Fat-soluble vitamins in human lactation.

Lactation has three distinct phases: colostrum, transition, and mature, with the quantity of fat-soluble vitamins and carotenoids tending to decline while the total fat content increases. The number of deliveries seems to be directly related to higher concentrations of beta-carotene and vitamin E in colostrum. Little is known about vitamin quantities during the other phases. In the present study, vitamin A and E concentrations during different phases of lactation were measured in primiparous and multiparous mothers to analyze the variation and suitability for the diet of a breastfed child. Phase of lactation and number of deliveries were highly significant for log mean vitamin A while only one phase showed significance for log mean vitamin E. There was a sharp decline in the levels of vitamin A and E in the course of the initial phase of lactation. The variability between measurements declined as colostrum transitioned to mature milk. There were significant measurable inter-group differences in retinol levels in milk obtained during early lactation. Vitamin A and E content can reach 2.5 and 1.4 times of levels recommended intake, respectively.

[Effect of moderate salt restriction on the antihypertensive action of nifedipine: a double blind study]. / Influencia de la restricción salina moderada sobre la actividad antihipertensiva de la nifedipina: un estudio doble ciego.

Moderate salt restriction is of debatable efficacy in the treatment of mild or moderate hypertension; however, salt restriction enhances the activity of most antihypertensive drugs. Some observations suggest that the antihypertensive activity of calcium antagonists is not increased or could even decrease with dietary salt restriction. In the present work 15 patients suffering arterial hypertension and normal renal function are studied during four two week periods; a) unrestricted diet and medication, b) unrestricted diet and nifedipine (40 mg/day), c) low salt diet (5 g of salt/day) and nifedipine, and d) the same low salt diet, nifedipine and a salt supplement (6 g/day); salt or placebo were given in a double blind manner. At the end of each period arterial blood pressure was recorded, a urine sample for sodium determination was taken, and a blood sample was drawn for serum renine activity and biochemical parameters; at the end of each period patients' weight was recorded. Blood pressure significantly decreased (systolic: 9.83%, and dyastolic 11.17%) in patients treated with nifedipine, with no differences observed with salt modifications. Urinary sodium reflected correctly dietary salt modifications. Serum renine activity significantly increased during salt restriction. No significant changes were observed in weight or in the biochemical parameters studied. These results seem to suggest that the antihypertensive effect of nifedipine in patents suffering mild to moderate essential hypertension, with no change observed is not altered by the amount of salt in diet, at least within the limits studied (89.7 to 190 mEq/day of Sodium).

Induction of gentamicin resistance by visible light.

Recent studies have demonstrated the ability of visible light or phototherapy to modify the intracellular DNA of prokaryotic and eukaryotic cells. The present study was undertaken to determine the effect of light used in phototherapy on antibiotic resistance in prokaryotic cells using tester strains of gentamicin-sensitive Escherichia coli and Staphylococcus aureus. A growing population of the tester microorganisms was inoculated on plates containing nutrient medium and gentamicin. Experiments were performed to determine the effect of blue light on the induction of gentamicin-resistant mutants. The plates were divided into two populations, one of which was illuminated, while the other was kept in the dark to serve as a control. During photoirradiation, the plates were protected from direct sunlight and air coded to maintain a temperature of 27 degrees C. The sample distance from the light source was adjusted to maintain a fluence rate (450 nm) of 141 uW/cm2. Control experiments were performed to investigate the effect of photoirradiation on the media and gentamicin. An increased frequency of mutation to gentamicin resistance was seen in the irradiated population of bacteria. The mutagenic effect was observed over a wide range of gentamicin concentrations and correlated in a linear fashion with increasing duration of photoirradiation. There was an inverse correlation between the size of the bacterial inoculum and the recovery of mutant bacteria.