Doublecortin May Play a Role in Defining Chondrocyte Phenotype

Embryonic development of articular cartilage has not been well understood and the role of doublecortin (DCX) in determination of chondrocyte phenotype is unknown. Here, we use a DCX promoter-driven eGFP reporter mouse model to study the dynamic gene expression profiles in mouse embryonic handplates at E12.5 to E13.5 when the condensed mesenchymal cells differentiate into either endochondral chondrocytes or joint interzone cells. Illumina microarray analysis identified a variety of genes that were expressed differentially in the different regions of mouse handplate. The unique expression patterns of many genes were revealed. Cytl1 and 3110032G18RIK were highly expressed in the proximal region of E12.5 handplate and the carpal region of E13.5 handplate, whereas Olfr538, Kctd15, and Cited1 were highly expressed in the distal region of E12.5 and the metacarpal region of E13.5 handplates. There was an increasing gradient of Hrc expression in the proximal to distal direction in E13.5 handplate. Furthermore, when human DCX protein was expressed in human adipose stem cells, collagen II was decreased while aggrecan, matrilin 2, and GDF5 were increased during the 14-day pellet culture. These findings suggest that DCX may play a role in defining chondrocyte phenotype.     

Surgical pathology of submandibular gland. Experience in La Rioja community

The AA. had work through medical histories of 44 patients operated for inflammatory and tumoral pathology of submandibular gland. Between inflammatory diseases they emphasize sialolithiasis (45%), acute submaxillaritis (18%) and Kuttner's tumor (11%). Pleomorphic adenoma accounted for the 50% of tumors. Diagnosis was based on each peculiar history sheet, on imaging procedures (simple X-ray plate, echography, sialography, TC) and extemporaneous biopsy. In all cases a complete exeresis of the gland was performed. In malignoma cases the procedure was completed with a prophylactic neck dissection. Incidence of lasting paralysis of the ramus marginalis mandibulae accounted for 6.8%.     

Calculation of the Orientation Relationships of Directionally Solidified Eutectic Ceramics by a Modified Coincidence of Reciprocal Lattice Points Model (CRLP)

The Coincidence of Reciprocal Lattice Points (CRLP) method was used to predict, according to geometric considerations, the most favorable orientation relationships (ORs) between the component phases in a family of directionally solidified eutectic ceramics (DSEC) (NiO–YSZ, CoO–YSZ, NiO–CeO₂, NiO–GDC, CoO–CeO₂, and CoO–GDC) grown by the laser floating zone method. The ORs predicted by the CRLP model are consistent with those experimentally found in a previous work by means of Electron Backscatter Diffraction (EBSD). In this article, we also present a modification to the model with the aim of taking into account that the most stable ceramic–ceramic interfaces are usually formed between atomic planes with low Miller indices, due to their higher atomic density and bigger interplanar spacing. Thus, we introduce in the calculation of the overall coincidence volume a weighting factor which is a function of the interplanar spacing. This modified CRLP method has been applied to the aforementioned eutectic ceramics, and the results are presented and discussed in comparison with the traditional CRLP results and the experimental findings.     

Surgical pathology of parotid gland tumors

The records of 27 patients operated for parotid tumors were reviewed retrospectively. Pleomorphic adenoma was the most frequent tumor (37.1%) and required subtotal parotidectomy in all cases. Twenty percent presented permanent facial paralysis of the marginal mandibular branch. No recurrence has been observed in five years of follow-up. Warthin's tumor, found in 11.1% of patients, was removed by either superficial or subtotal parotidectomy. Parotidean cysts were observed in 7.4% and were excised by superficial parotidectomy. The malignant tumors included squamous cell carcinoma (22.2%), adenoid cystic carcinoma (14.8%), melanoma (3.7%), and renal-cell metastasis (3.7%). All were treated by total parotidectomy with conservation of the facial nerve in 67%. Twenty-five percent had postoperative facial paralysis and 33% developed Frey's syndrome. Thirty-three percent died in the next 5 years from locoregional metastases.     

Preparation and physicochemical properties of edible films from gelatin and Andean potato (Solanum tuberosum Group Phureja) starch

A novel edible film formulation using native Andean potato starch (APS) and gelatin (G) was developed, and evaluated as a function of the APS/G ratio (3:1, 1:1, and 1:3). The films were physicochemically, structurally (FTIR and Raman), morphologically (SEM), thermally (DSC/TGA) and mechanically characterised. The addition of starch increased water resistance, clarity and thermal stability of the films. The SEM micrographs showed a heterogeneous surface and a compact structure. The films also showed low values for both tensile strength and elastic modulus. FTIR analysis revealed intermolecular interactions between the gelatin and starch. Edible film obtained in this work may have potential applications in many fields.     

Diminished adherence and/or ingestion of virulent Mycobacterium tuberculosis by monocyte-derived macrophages from patients with tuberculosis

The interaction between the macrophage and Mycobacterium tuberculosis is mediated by a variety of macrophage membrane-associated proteins. Complement receptors have been implicated in the adherence of M. tuberculosis to macrophages. In the present work, the adherence and/or ingestion of M. tuberculosis H37Rv to human monocyte-derived macrophages (MDM) from patients with tuberculosis (TB) and healthy controls was measured by microscopical examination, [3H]uracil incorporation, and CFU. The adherence and/or ingestion was enhanced by fresh serum and inhibited by heat inactivation, EDTA treatment, and anti-CR1 and anti-CR3 antibodies. Comparison of MDM from TB patients and healthy controls showed that the former exhibited a significantly decreased capacity to adhere and/or ingest M. tuberculosis, as determined by the number of CFU and 3H incorporation. The expression of CR1 (CD35) and CR3 (CD11b/CD18) on MDM from TB patients and healthy controls, as determined by flow cytometry, did not show significant differences. These results suggest that the lower ingestion of M. tuberculosis by MDM from TB patients is not due to defects in complement receptors, and therefore, there might be other molecules involved in the adherence and/or ingestion process that render MDM from TB patients ingest less mycobacteria than those from healthy controls.     

Toughening and brittle‐tough transition in polyamide 12‐organoclay/maleated styrene‐ethylene‐co‐butylene‐styrene nanocomposites

Tough nanocomposites based on polyamide 12 (PA12) can be obtained by the addition of a maleated rubber to a highly dispersed PA12‐clay nanocomposite by melt processing. The nanostructure behavior was evaluated by X‐ray diffraction and transmission electron microscopy. The results showed that the organoclay was highly dispersed and mostly located in the PA12 matrix due to the larger affinity between the polyamide and the clay, but some of the organoclay was also present in the polymer/polymer interface. The presence of organoclay slightly increased the dispersed particle size, indicating decreased compatibilization. This was attributed to a partial shielding of maleic anhydride compatibilizer by surfactant. The addition of the elastomer considerably improved the toughness of the PA12‐based nanocomposites, maintaining its stiffness; i.e., the nanocomposites with 25% rubber content showed an increase of 25‐fold of notched impact strength of the PA12 matrix, meanwhile ductility and stiffness remained constant. This allowed us to obtain toughened PA12 PNs throughout a large range of strain rate and a modulus similar to that of the unmodified PA12. The position of the brittle/tough transition in terms of rubber content, determined by the standard notched Izod test (25% mSEBS) is basically the same as that determined by the essential work of fracture procedure. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Structure,thermal stability,and mechanical properties of nanocomposites based on an amorphous polyamide

Polymer nanocomposites based on an amorphous polyamide (aPA) modified with three organoclays were obtained in the melt state. The observed T_g decreases indicated that some organic modifier of the OMMT (surfactant) migrated to the matrix during mixing. The decrease in the thermal stability of the aPA in nitrogen atmosphere on organoclay addition was attributed to the instability of the organoclays. The smaller decrease in the thermal stability of the nanocomposites in air atmosphere was attributed to a barrier effect. The largest dispersion (an average of only 1.2 layers per particle) occurred using the octadecylamine‐modified organoclay (I30) that has the maximum uncovered surface; this indicates the basic importance of this parameter on exfoliation. Despite the bulky nature of the aPA that hinders the matrix/inorganic surface interactions, this dispersion level is comparable to that of semicrystalline polyamides with similar polarity. This indicates that the relation between high polarity of the matrix and high dispersion level also works in bulky aPAs, as that of this study. The significant modulus increases (56% for the nanocomposite with 5% I30) are consistent with the measured high dispersion level. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers