Novel oral microscope gives mechanistic insights into colloidal drivers of friction in oral biofilms.

Texture and mouthfeel are central to the sensory enjoyment of food and beverages. Yet our incomplete understanding of how food boluses are transformed in the mouth limits our texture prediction ability. As well as thin film tribology, the interaction of food colloids with the oral tissue and salivary biofilms plays a key role in texture perception via mechanoreceptors in the papillae. In this study we describe the development of an oral microscope capable of quantitative characterization of the inactions of food colloids with papillae and their concurrent saliva biofilm. We also highlight how the oral microscope revealed key microstructural drivers of several topical phenomena (oral residue formation, coalescence in-mouth, grittiness of protein aggregates and finally microstructural origin of polyphenol astringency) in the domain of texture creation. The coupling of a fluorescent food grade dye with image analysis enabled specific and quantitative determination of the microstructural changes in mouth. Emulsions either underwent no aggregation, small aggregation, or extensive aggregation depending on whether their surface charge facilitated complexation with the saliva biofilm. Quite surprisingly cationic gelatin emulsions that were already aggregated with saliva in mouth underwent coalescence if subsequently exposed to tea polyphenols (EGCG). Large protein aggregates were found to aggregate with the saliva coated papillae, increasing their size tenfold and possibly explaining why there are perceived as gritty. An exciting observation was the oral microstructural changes that occurred upon exposure to tea polyphenols (EGCG). Filiform papillae shrunk, and the saliva biofilm was seen to precipitate/collapse, exposing a very rough tissue surface. These tentative early steps are the first in vivo microstructural insights into the different food oral transformations that are drivers of key texture sensation.

Pharmacometabolomics study identifies circulating spermidine and tryptophan as potential biomarkers associated with the complete pathological response to trastuzumab-paclitaxel neoadjuvant therapy in HER-2 positive breast cancer.

Defining biomarkers that predict therapeutic effects and adverse events is a crucial mandate to guide patient selection for personalized cancer treatments. In the present study, we applied a pharmacometabolomics approach to identify biomarkers potentially associated with pathological complete response to trastuzumab-paclitaxel neoadjuvant therapy in HER-2 positive breast cancer patients. Based on histological response the 34 patients enrolled in the study were subdivided into two groups: good responders (n = 15) and poor responders (n = 19). The pre-treatment serum targeted metabolomics profile of all patients were analyzed by liquid chromatography tandem mass spectrometry and the differences in the metabolomics profile between the two groups was investigated by multivariate partial least squares discrimination analysis. The most relevant metabolites that differentiate the two groups of patients were spermidine and tryptophan. The Good responders showed higher levels of spermidine and lower amounts of tryptophan compared with the poor responders (p < 0.001, q < 0.05). The serum level of these two metabolites identified patients who achieved a pathological complete response with a sensitivity of 90% [0.79-1.00] and a specificity of 0.87% [0.67-1.00]. These preliminary results support the role played by the individual patients' metabolism in determining the response to cancer treatments and may be a useful tool to select patients that are more likely to benefit from the trastuzumab-paclitaxel treatment.

Grade 4 unclassified renal cell carcinoma with sarcomatoid component expressing S-100 protein. A case report with peculiar diagnostic and therapeutic implications.

Grade 4 unclassified renal cell carcinoma, with a sarcomatoid component (URCCSC) is a rare high grade tumor presumptively derived from all histological subtypes of renal cell carcinoma (RCC). Even though rare, URCCSC generates a great deal of interest, as it is a particularly aggressive variant of RCC, that is poorly responsive to chemo-immunotherapy. Whether it originates from a separate sarcomatoid cell clone within the tumor or from true cell dedifferentiation from RCC has yet to be established. The diagnosis of URCCSC is usually based on morphological and immunohistochemical characteristics of the neoplastic cells which show transitional epithelial/mesenchymal features. In fact, the frequent loss of epithelial markers and gain of mesenchymal phenotypes, can result in difficulties in interpreting diagnostic data. Consequently assigning the optimal therapeutic treatments can be hindered due to this biological "complexity." Here we present the clinicopathological records of a 51 year-old patient who underwent an excision of a periureteral retroperitoneal mass, and whose first pathological diagnosis was malignant peripheral nerve sheath tumor (MPNST). Eleven months after surgery, a CT-scan revealed a local recurrence of the disease. Later on the patient was admitted to our hospital and a systemic, sarcoma-oriented, treatment was initiated. A partial remission was observed but only with a dacarbazine based regimen administered as a third line therapy, after which a second surgery took place. The removed tumor was diagnosed as URCCSC based on the peculiar morphologic and immunohistochemical characteristics of the cells. Pathological assessment of the first intervention was re-evaluated, resulting in a diagnosis of URCCSC. This case-report therefore highlights the implications that an erroneous pathologic diagnosis can have for the clinical management of this disease. Furthermore, the unexpected response to a dacarbazine based regimen, indicates that this drug should be included among the therapeutic options available against this type of renal carcinoma.

Structural and compositional changes in the salivary pellicle induced upon exposure to SDS and STP.

Sodium dodecyl sulphate (SDS) and sodium tripolyphosphate (STP) act to remove stained pellicle from dentition and loosen deposits on tooth surfaces that may become cariogenic over time. This study investigated how SDS and STP impact the salivary pellicle adsorbed onto hydroxyapatite and silica sensors using a dual polarisation interferometer and a quartz-crystal microbalance with dissipation. After the pellicle was exposed to SDS and STP the remaining pellicle, although weaker, due to the loss of material, became less dense but with a higher elastic component; suggesting that the viscous component of the pellicle was being removed. This would imply a structural transformation from a soft but dense structured pellicle, to a more diffuse pellicle. In addition, the majority of proteins displaced by both SDS and STP were identified as being acidic in nature; implying that the negatively charged groups of SDS and STP may be responsible for the displacement of the pellicle proteins observed.