Differentiation of human bone marrow stem cells into cells with a neural phenotype: diverse effects of two specific treatments

BACKGROUND: It has recently been demonstrated that the fate of adult cells is not restricted to their tissues of origin. In particular, it has been shown that bone marrow stem cells can give rise to cells of different tissues, including neural cells, hepatocytes and myocytes, expanding their differentiation potential. RESULTS: In order to identify factors able to lead differentiation of stem cells towards cells of neural lineage, we isolated stromal cells from human adult bone marrow (BMSC). Cells were treated with: (1) TPA, forskolin, IBMX, FGF-1 or (2) retinoic acid and 2-mercaptoethanol (BME). Treatment (1) induced differentiation into neuron-like cells within 24 hours, while a longer treatment was required when using retinoic acid and BME. Morphological modifications were more dramatic after treatment (1) compared with treatment (2). In BMSC both treatments induced the expression of neural markers such as NF, GFAP, TUJ-1 and neuron-specific enolase. Moreover, the transcription factor Hes1 increased after both treatments. CONCLUSION: Our study may contribute towards the identification of mechanisms involved in the differentiation of stem cells towards cells of neural lineage

Analytical methods for the evaluation of α-L-fucosidase activity in sheep milk

The lack of analytical methods for measuring the activity of highly thermolable endogenous enzymes in sheep milk is a factor that hampers the protection of typical Protected Designation of Origin (PDO) dairy products made from raw milk. In order to provide a solution, this study assesses, tests, and fully validates analytical procedures for the determination of α-L-fucosidase activity in sheep milk. While the UV–VIS method has been optimized for this matrix in order to solve clarification problems before the spectrophotometric reading, a reversed phase high-performance liquid chromatography literature method proposed for bovine milk has been successfully applied also to sheep milk. Both methods have been fully validated in terms of sensitivity, linearity, precision, and accuracy, displaying low detection and quantification limits, excellent linearity over a wide enzymatic activity interval, very good repeatability and reproducibility, and the lack of any bias. The analysis of a number of real samples of whole sheep milk has allowed the evaluation of an average value (46.78 ± 5.49 U mL−1) and range (from 29.27 ± 2.60 to 72.64 ± 1.17 U mL−1) of α-L-fucosidase activity. Such activity does not seem to differ substantially from those measured for bovine milk. Finally, marked seasonal variability has been observed in this preliminary dataset

Assessment and validation of methods for the determination of γ-glutamyltransferase activity in sheep milk

The determination of enzymatic activity in sheep milk is still today a practically unexplored field of research. This study proposes and fully validates two analytical procedures (i.e. by means of UV-vis spectrophotometry and RP-HPLC methods) for the determination of γ-glutamyltransferase activity in sheep milk. Both methods are characterised by low detection and quantification limits, excellent linearity over a wide enzymatic activity interval, very good repeatability and reproducibility, and are bias-free. The RP-HPLC method provides better sensitivity and automation capability levels than that of UV-vis, and its use is hence suggested for screening purposes. These methods have been preliminarily tested with a number of real samples of whole sheep milk, obtaining an average γ-glutamyltransferase activity value of 2.93 ± 0.50 U ml−1 and a range from 2.72 ± 0.10 U ml−1 to 3.46 ± 0.11 U ml−1

Sensory profile development for an Italian PDO ewe’s milk cheese at two different ripening times

The sensory profile technique was applied to the Italian Protected Designation of Origin (PDO) Fiore Sardo cheese, made exclusively from raw ewe's milk in artisanal farms in Sardinia. The descriptive sensory analysis was used to find the sensory attributes which characterize this PDO cheese at two different ripening times (105 and 180 days). The product specification states that the cheese must have no less than 105 days of maturation before being sold, while at more than 180 days it is usually used grated. Twelve expert panelists, whose efficacy was confirmed by variance analysis, identified and evaluated 10 sensory attributes on cheese samples: smoked and rennet for odor; sour and salty for taste, piquant for trigeminal sensation; smoked and rennet for aroma; floury, grainy and friability for texture. The judges were also asked to provide an overall evaluation of sensory typicality. Cheeses from different farms ripened for 105 days differed significantly for smoked odor, salty, grainy and typicality, whereas the cheeses ripened for 180 days were significantly different for smoked odor, piquant, friability and sensory typicality. The comparison between cheeses from the same farm at 105 and 180 days showed no significant differences

Thermal inactivation and variability of γ-glutamyltransferase and α-<span>L</span>-fucosidase enzymatic activity in sheep milk

We present a study of the thermal inactivation and variation of activity of two enzymes in sheep milk: γ-glutamyltransferase and α-L-fucosidase. We find that the thermal treatment of milk causes inactivation of α-L-fucosidase between 57 °C and 68 °C, and γ-glutamyltransferase between 68 °C and 80 °C. In untreated sheep milk, the highest level of enzymatic activity (EA) for these two enzymes is in the pH range 5.5–6.0 and 8.0–8.5, respectively. Skimming treatment causes the loss of 35% of the activity of γ-glutamyltransferase. No differences in the EA were ascribable to the diets evaluated in this study. We observed EAs of α-L-fucosidase and γ-glutamyltransferase over the entire lactation cycle, noting that the EA of the former increased from 81 to 207 U mL−1 (average 159 ± 30 U mL−1) while the EA of the latter from 3.12 to 4.89 U mL−1 (average 3.83 ± 0.34 U mL−1). Relationships between both enzymes and selected milk parameters (lipids, proteins, lactose, urea and somatic cells) are highlighted by Principal Component Analysis

Prediction of fatty acid content in sheep milk by Mid-Infrared spectrometry with a selection of wavelengths by Genetic Algorithms

Sheep breeding is one of the most widespread activities in Sardinia (Italy), and milk produced here is of crucial economic importance for the region. In order to make the milk payment system used in Sardinia more rewarding to the quality of milk, we developed Partial Least Square regression models to predict the concentration of the major fatty acids (measured with a GC-FID reference method) from the Mid- Infrared spectra of hundreds of Sardinian sheep milk samples collected in the period 2011e2013. Genetic Algorithms were used in order to select the most informative spectral subsets and therefore reduce the complexity of the model and in many cases also reduce the prediction error. Models obtained had a good predictive ability, with errors in the range of tenths of a gram of fatty acid on Kg of milk, and an acceptable precision for an immediate introduction on sheep milk payment in Sardinia

Optimization of a newly established gas-chromatographic method for determining lactose and galactose traces: Application to Pecorino Romano cheese

In this work, we present and validate new gas-chromatographic with flame injection detector method to measure traces of lactose and galactose in cheese. Analytes are first extracted from the matrix by repeated treatments with a 40% (v/v) methanol/water solution, followed by their silanization with a 2:1 mixture of trimethylsilylimidazole and trimethylchlorosilane. Validation parameters show excellent limits of detection and quantification, and very good precision and trueness. The method was tested with a wide sampling of Protected Designation of Origin (PDO) Pecorino Romano sheep cheese (33 samples, different for geographic area of production, seasonality and ripening levels). For all of them, the concentration of lactose and galactose were always below the relevant limits of detection (i.e. 0.54 and 0.90 mg kg−1, respectively). On this basis, PDO Pecorino Romano sheep cheese is, according to both European Community and European Food Safety Authority guidelines, a “lactose free” foodstuff, useful in the dietary management of patients with galactosaemia and of people who are lactose intolerant

SPME/GC-MS characterization of the volatile fraction of an Italian PDO sheep cheese to prevalent lypolitic ripening: the case of Fiore Sardo

A specifically aimed SPME/GC-MS method has been assessed in order to describe the volatile fraction of intense flavoring cheeses like Fiore Sardo PDO, a prevalent lipolytic ripening sheep cheese from Sardinia, Italy. A DVB/ CAR/PDMS 50/30 μm fiber and a 3-min exposure time showed to be the best compromise between the possibility to extract compounds with a wide range of polarity and molecular mass and the need to avoid competition and displacement effects among analytes. The volatile compound profile of Fiore Sardo PDO sheep cheese was largely characterized by carboxylic acids (about 68% of the total area of recognized peaks), whereas esters (14%), ketones (9%), and alcohols (8%) represented other abundant classes of low molecular weight species. A number of low-smelling thres- hold trace compounds were also identified as likely contributors of aroma of the Fiore Sardo PDO cheese