Preliminary evaluation of probiotic properties of Lactobacillus strains isolated from Sardinian dairy products

Twenty-three Lactobacillus strains of dairy origin were evaluated for some functional properties relevant to their use as probiotics. A preliminary subtractive screening based on the abilities to inhibit the growth of microbial pathogens and hydrolyze conjugated bile salts was applied, and six strains were selected for further characterization including survival under gastrointestinal environmental conditions, adhesion to gut epithelial tissue, enzymatic activity, and some safety properties. All selected strains maintained elevated cell numbers under conditions simulating passage through the human gastrointestinal tract, well comparable to the values obtained for the probiotic strain Lactobacillus rhamnosus GG, and were able to adhere to Caco-2 cells to various extents (from 3 to 20%). All strains exhibited high aminopeptidase, and absent or very low proteolytic and strong β-galactosidase activities; none was found to be haemolytic or to produce biogenic amines and all were susceptible to tetracycline, chloramphenicol, erythromycin, ampicillin, and amoxicillin/clavulanic acid. Our results indicate that the Lactobacillus strains analyzed could be considered appropriate probiotic candidates, due to resistance to GIT simulated conditions, antimicrobial activity, adhesion to Caco-2 cell-line, and absence of undesirable properties. They could be used as adjunct cultures for contributing to the quality and health related functional properties of dairy products

Circadian rhythms of histatin 1, histatin 3, histatin 5, statherin and uric acid in whole human saliva secretion

The circadian rhythms of histatins 1, 3, 5, of statherin and uric acid were investigated in whole human saliva. Histatins showed a rhythm approximately synchronous with salivary flow rate (acrophase around 5 pm), the higher amplitude pertaining to histatin 1 (about 50% of the mesor). Uric acid showed a large rhythm asynchronous with flow rate and histatin concentrations (4.4 ± 1.4 am). Statherin did not show a significant circadian rhythm on five of six volunteers. This finding confirms that the secretion route of statherin is different from that of histatins

A Pair of Dopamine Neurons Target the D1-Like Dopamine Receptor DopR in the Central Complex to Promote Ethanol-Stimulated Locomotion in Drosophila

Dopamine is a mediator of the stimulant properties of drugs of abuse, including ethanol, in mammals and in the fruit fly Drosophila. The neural substrates for the stimulant actions of ethanol in flies are not known. We show that a subset of dopamine neurons and their targets, through the action of the D1-like dopamine receptor DopR, promote locomotor activation in response to acute ethanol exposure. A bilateral pair of dopaminergic neurons in the fly brain mediates the enhanced locomotor activity induced by ethanol exposure, and promotes locomotion when directly activated. These neurons project to the central complex ellipsoid body, a structure implicated in regulating motor behaviors. Ellipsoid body neurons are required for ethanol-induced locomotor activity and they express DopR. Elimination of DopR blunts the locomotor activating effects of ethanol, and this behavior can be restored by selective expression of DopR in the ellipsoid body. These data tie the activity of defined dopamine neurons to D1-like DopR-expressing neurons to form a neural circuit that governs acute responding to ethanol

Risk factors for oral mucositis in paediatric oncology patients receiving alkylant chemotherapy

BACKGROUND: We describe the risk indicators for oral mucositis (OM) in paediatric oncology patients hospitalised in the Institut Gustave Roussy (Villejuif-Paris) and treated with alkylant chemotherapy with autologous peripheral blood progenitor cells. METHODS: The sample was selected using PIGAS software. Three groups of subjects received different chemotherapy regimens: A. Melphalan, B. Busulfan and C. other alkylant protocols. The degree of mucositis was recorded by CTC version 2.0 (Common Toxicity Criteria). Descriptive statistics were performed. The association between mucositis and risk indicator variables was tested using a χ(2 )test. The association between case status and covariates was tested using unconditional logistic regression analysis. RESULTS: Of the 337 children enrolled, 241 showed mucositis (group 1) and 96 did not show mucositis (group 2) during alkylant chemotherapy. There was a higher prevalence of male patients in both groups. The three different chemotherapy regimen groups are correlated with the appearance of oral mucositis (χ(2 )= 22.42, p < 0.01). Weight loss was higher in group 1 (χ(2 )= 6.31, p = 0.01). The duration of aplasia was lower in the Busulfan protocol (7.5 days) than in the Melphalan group (9.3 days) or the other regimens (8.6 days). The use of Bufulfan(® )was directly associated with case status (presence of oral mucositis): odds ratio [OR] = 2.1 and confidence interval [95%CI] = 1.3–3.0. Also, occurrences of germinal tumours and secondary bacterial infections were directly linked with case status: [OR] = 1.4 and 1.8, confidence interval [95%CI] = 1.2 – 1.7 and 1.1 – 2.5, respectively. CONCLUSION: The presence of OM was associated with the three different chemotherapy regimens considered; in particularly patients treated with Busulfan had the highest prevalence

Cytochrome c used as a model system to probe the structural properties of benthic mucilage

Benthic mucilage, whether native or artificially fragmented to microscopic dimensions by ultrasonic treatment, was mixed with cytochrome c, which was used as a 12000 Da polycationic model compound. Cytochrome c binding profiles proved to depend on the aggregation state of the mucilage. The native mucus matrix binds cytochrome c quasi hyperbolically with an apparent affinity constant K = 1 x 106 M-1. As shown by chemical modification of both the mucilage and cytochrome c, the binding expression is dependent on the availability of both the positive charges on the cytochrome c surface and the negative charges within the mucus matrix. The extent of binding is sensitive to the ionic strength of the medium. The ultrasonic-stabilized mucus fragments display a peculiar binding profile, with an apparent low affinity, abruptly entering into a high affinity binding region. The results suggest that, depending on the mucus to polycation ratio, a polymeric reticulus builds up. This reticulus can accommodate molecules of at least 12000 Da molecular weight. The results are also discussed with respect to biological implications

A highly active fungal β-glucosidase - Purification and properties

A highly active thermostable beta-glucosidase was purified to homogeneity from a strain of Trichoderma sp. The enzyme was an extracellular glycoprotein and showed hydrolytic activity toward several beta-glucosides. Cellobiose was found to be the substrate of choice for this enzyme. This finding could suggest future technological applications of the purified protein