Peter Dockery

Activation of Akt/PKB, increased phosphorylation of Akt substrates and loss and altered distribution of Akt and PTEN are features of Alzheimer's disease pathology

Studies suggest that activation of phosphoinositide 3‐kinase‐Akt may protect against neuronal cell death in Alzheimers disease (AD). Here, however, we provide evidence of increased Akt activation, and hyperphosphorylation of critical Akt substrates in AD brain, which link to AD pathogenesis, suggesting that treatments aiming to activate the pathway in AD need to be considered carefully. A different distribution of Akt and phospho‐Akt was detected in AD temporal cortex neurons compared with control neurons, with increased levels of active phosphorylated‐Akt in particulate fractions, and significant decreases in Akt levels in AD cytosolic fractions, causing increased activation of Akt (phosphorylated‐Akt/total Akt ratio) in AD. In concordance, significant increases in the levels of phosphorylation of total Akt substrates, including: GSK3βSer9, tauSer214, mTORSer2448, and decreased levels of the Akt target, p27kip1, were found in AD temporal cortex compared with controls. A significant loss and altered distribution of the major negative regulator of Akt, PTEN (phosphatase and tensin homologue deleted on chromosome 10), was also detected in AD neurons. Loss of phosphorylated‐Akt and PTEN‐containing neurons were found in hippocampal CA1 at end stages of AD. Taken together, these results support a potential role for aberrant control of Akt and PTEN signalling in AD.

Potential role of mesenchymal stem cells (MSCs) in the breast tumour microenvironment: stimulation of epithelial to mesenchymal transition (EMT)

Bone marrow-derived mesenchymal stem cells (MSCs) are known to specifically migrate to and engraft at tumour sites. Understanding interactions between cancer cells and MSCs has become fundamental to determining whether MSC-tumour interactions should be harnessed for delivery of therapeutic agents or considered a target for intervention. Breast Cancer Cell lines (MDA-MB-231, T47D & SK-Br3) were cultured alone or on a monolayer of MSCs, and retrieved using epithelial specific magnetic beads. Alterations in expression of 90 genes associated with breast tumourigenicity were analysed using low-density array. Expression of markers of epithelial–mesenchymal transition (EMT) and array results were validated using RQ-PCR. Co-cultured cells were analysed for changes in protein expression, growth pattern and morphology. Gene expression and proliferation assays were also performed on indirect co-cultures. Following direct co-culture with MSCs, breast cancer cells expressed elevated levels of oncogenes (NCOA4, FOS), proto-oncogenes (FYN, JUN), genes associated with invasion (MMP11), angiogenesis (VEGF) and anti-apoptosis (IGF1R, BCL2). However, universal downregulation of genes associated with proliferation was observed (Ki67, MYBL2), and reflected in reduced ATP production in response to MSC-secreted factors. Significant upregulation of EMT specific markers (N-cadherin, Vimentin, Twist and Snail) was also observed following co-culture with MSCs, with a reciprocal downregulation in E-cadherin protein expression. These changes were predominantly cell contact mediated and appeared to be MSC specific. Breast cancer cell morphology and growth pattern also altered in response to MSCs. MSCs may promote breast cancer metastasis through facilitation of EMT.

Network Formation in Gluten-Free Bread with Application of Transglutaminase

ABSTRACT One of the main problems associated with gluten-free bread is obtaining a good structure. Transglutaminase (TGase), an enzyme that catalyzes acyl-transfer reactions through which proteins can be cross-linked could be a way to improve the structure of gluten-free breads. The objective of this study was to evaluate the impact of TGase at different levels (0, 0.1, 1, and 10 U of TGase/g of protein) on the quality of gluten-free bread. The recipe consisted of white rice flour (relative amount: 35), potato starch (30), corn flour (22.5), xanthan gum (1), and various protein sources (skim milk powder [SMP] [12.5], soya flour, and egg powder). The influence of the various proteins in combination with the different addition levels of TGase on bread quality (% bake loss, specific volume, color, texture, image characteristics, and total moisture) was determined. Confocal laser-scanning microscopy (CLSM) was used to evaluate the influence of TGase on the microstructure of the bread. Baking tests showed that...

Textural Comparisons of Gluten-Free and Wheat-Based Doughs, Batters, and Breads

ABSTRACT Studies were conducted with two newly developed gluten-free bread recipes. One was based on corn starch (relative amount 54), brown rice (25), soya (12.5), and buckwheat flour (8.5), while the other contained brown rice flour (50), skim milk powder (37.5), whole egg (30), potato (25), and corn starch (12.5), and soya flour (12.5). The hydrocolloids used were xanthan gum (1.25) and xanthan (0.9) plus konjac gum (1.5), respectively. Wheat bread and gluten-free bread made from commercial flour mix were included for comparison. Baking tests showed that wheat and the bread made from the commercial flour mix yielded significantly higher loaf volumes (P < 0.01). All the gluten-free breads were brittle after two days of storage, detectable by the occurrence of fracture, and the decrease in springiness (P < 0.01), cohesiveness (P < 0.01), and resilience (P < 0.01) derived from texture profile analysis. However, these changes were generally less pronounced for the dairy-based gluten-free bread, indicating ...

Carbon Nanotubes and Mesenchymal Stem Cells : Biocompatibility, Proliferation and Differentiation

The synergy of the unique properties of carbon nanotubes (CNT) with the remarkable potential of human mesenchymal stem cells (hMSC) provides an exciting opportunity for novel therapeutic modalities. However, little is known about the impact of CNT on hMSC behavior. We report the effect of CNT on hMSC renewal, metabolic activity, and differentiation. Furthermore, we tracked the intracellular movement of CNT through the cytoplasm to a nuclear location and assessed effects on cellular ultra structure.

Neurotrophin-3-mediated regeneration and recovery of proprioception following dorsal rhizotomy.

Injured dorsal root axons fail to regenerate into the adult spinal cord, leading to permanent sensory loss. We investigated the ability of intrathecal neurotrophin-3 (NT3) to promote axonal regeneration across the dorsal root entry zone (DREZ) and functional recovery in adult rats. Quantitative electron microscopy showed robust penetration of CNS tissue by regenerating sensory axons treated with NT3 at 1 and 2 weeks postrhizotomy. Light and electron microscopical anterograde tracing experiments showed that these axons reentered appropriate and ectopic laminae of the dorsal horn, where they formed vesicle-filled synaptic buttons. Cord dorsum potential recordings confirmed that these were functional. In behavioral studies, NT3-treated (but not untreated or vehicle-treated) rats regained proprioception. Recovery depended on NT3-mediated sensory regeneration: preventing regeneration by root excision prevented recovery. NT3 treatment allows sensory axons to overcome inhibition present at the DREZ and may thus serve to promote functional recovery following dorsal root avulsions in humans.

A new method of histologic dating of human endometrium in the luteal phase

Morphometric analysis was performed on 70 endometrial biopsy specimens collected from a population of fertile women. Of the 17 morphometric measurements that were performed on each endometrial biopsy, only 5 were required to achieve a highly significant correlation with chronologic dating based on luteinizing hormone surge (R = 0.99). The result of histologic dating, based on morphometric analysis of endometrial biopsies collected from a separate, unbiased population, correlated strongly and significantly with chronologic dating (r = 0.98, P less than 0.0001). The correlation was better than that achieved when histologic dating was performed according to the conventional dating criteria (r = 0.88, P less than 0.001).

WHEAT SOURDOUGH FERMENTATION: EFFECTS OF TIME AND ACIDIFICATION ON FUNDAMENTAL RHEOLOGICAL PROPERTIES

ABSTRACT The fundamental rheological characteristics of a biologically acidified, a chemically acidified, and a neutral preferment (sourdough) were monitored over the course of a 24-hr fermentation period using a split-plot design. Three doughs were subsequently prepared in which 20% of the flour was in the form of the respective preferment. A control dough containing no fermented material was also prepared. The fundamental rheological properties of both the dough and its isolated wet gluten were determined. Laser-scanning confocal microscopy was used to capture images of selected preferments and doughs. Results from the preferment showed that there was a decrease in elasticity (phase angle data from oscillatory measurements and relative recovery values from creep tests) and viscosity with fermentation time for all three preferments, all of which reached similar end values for these parameters. The microscopy images illustrated that the gluten strands were dissolved to a more amorphous structure during th...

A comparison between two methods of chronological dating of human endometrial biopsies during the luteal phase, and their correlation with histologic dating

This prospective study was performed on 61 infertile women to examine the correlation between histologic dating using the same criteria by two independent observers and chronological dating by two different methods: (1) determination of luteinizing hormone (LH) peak by daily LH assay, (2) calculation based on the onset of the next menstrual period (NMP). The correlation between histologic dating and chronological dating was found to be significantly better if the LH peak was used to determine the chronological date than if the NMP was used (r = 0.70 and 0.37, respectively).

How precise is histologic dating of endometrium using the standard dating criteria

Sixty-three endometrial biopsies were dated histologically by using the standard criteria on two separate occasions by the same observer. Overall, it was found that exact agreement occurred in 15 (24%), but disagreement of more than 2 days occurred in 6 (10%). The proportion of exact agreement in the first half of the luteal phase (32%) was found to be significantly higher (P less than 0.05) than that in the second half of the luteal phase (9%). In a separate part of the study, 27 women had two endometrial biopsies, each performed in a separate cycle. The within-subject between-cycle variation of the results of endometrial dating (exact agreement: 4%, disagreement of more than 2 days: 41%) was found to be significantly different from intraobserver variation (P less than 0.01 for both). The amount of intraobserver variation suggests that the traditional dating criteria are not precise enough to quantify corpus luteum function in the second half of the luteal phase, whereas the amount of within-subject between-cycle variation implies that the result of endometrial dating in one cycle cannot be used reliably to predict that of another cycle.