Esterification of high amylose starch with short chain fatty acids modulates degradation by Bifidobacterium spp.

Large bowel luminal short chain fatty acids (SCFA) are protective against gut diseases such as colorectal cancer, Crohn’s disease and ulcerative colitis. High amylose maize starches acylated with acetic, propionic or butyric were previously shown to deliver SCFA to the gut and increase gut SCFA. This study examines the ability of five Bifidobacterium spp. (B. longum, B. breve, B. infantis, B. adolescentis and B. bifidum), Ruminococcus bromii and Faecalibacterium prausnitzii to degrade starches acylated with SCFA. Release of SCFA from modified starches was not observed, suggesting no preferential hydrolysis of the SCFA ester bond over the glycosidic bond. Acetylated and propionated starches are more readily degraded than either the base or butyrated starches in tested cultures. These observed differences may depend on modification to the starch structure. These structural differences alter the kinetics of starch digestion, irrespective of bacterial type, which may impact current approaches of prebiotic selection.Ya-Mei Lim, Mary B.Barnes, Sally L.Gras, Chris McSweeney, Trevor Lockett, Mary Ann Augustin, Paul R.Goole

Hydrodynamic radii of solubilized high amylose native and modified starches by pulsed field gradient NMR diffusion measurements

Over the last decade, there has been an increase in the application of pulsed field gradient nuclear magnetic resonance (PFG NMR) to characterize food materials. In this work, PFG NMR was used to examine the impact of chemical modification on properties of solubilized high amylose starches obtained from heated (121 °C for 15 min) starch suspensions (0.5% w/w). The starches examined were high amylose maize starch (HAMS) and high amylose maize starch chemically modified with acetate (HAMSA), propionate (HAMSP) and butyrate (HAMSB) at degree of substitution (DS) of 0.2. The hydrothermal treatment solubilized 3.36–4.96% of the starch in all samples, corresponding to concentrations of 10.36–10.91 μM on glucose equivalents basis. The hydrodynamic radii of the starches were 30 Å (HAMS), 45 Å (HAMSB), 60–70 Å (HAMSA & HAMSP). Contrary to expectations, the radii did not increase with the molecular weight of the fatty acid attached to the starch. Rather, the trend in the observed hydrodynamic radii was related to the physical organization of the starch molecules in higher DS granular dried starch (DS = 0.32–0.40) as observed by others using X-ray diffraction and small angle X-ray scattering, suggesting the preservation of the nano-structure of starch molecules upon solubilization. Upon storage (7 days at 25 °C), there was retrogradation of HAMS but not of modified HAMS. Given the correlation between retrogradation and food spoilage, the inhibition of retrogradation in the soluble fraction of modified HAMS may increase the stability of starch containing foods.Ya-Mei Lim, Shenggen Yao, Sally L.Gras, Chris McSweeney, Trevor Lockett, Mary Ann Augustin, Paul R.Goole

The diagnostic significance of the detection of cytokeratin 19 mRNA by quantitative RT-PCR in benign and malignant pleural effusions

Objective: To evaluate the diagnostic significance of detecting cytokeratin 19 (CK19) mRNA by quantitative reverse transcription polymerase chain reaction (RT-PCR) in benign and malignant pleural effusions. Methods: CK19 mRNA was examined by quantitative RT-PCR and CK19 was detected by Enzyme-linked immunoadsorbent assay (ELISA) in 32 patients with malignant pleural effusions and 35 patients with benign pleural effusions. Results: On the threshold of 200 copies/μl, the positive rate of CK19 mRNA in patients with malignant pleural effusions was 62.5%. The positive rates of CK19 mRNA and CK19 in the malignant pleural effusions were significantly higher than those in the benign group (P<0.01). Furthermore, the positive rate of CK19 mRNA was higher than that of CK19 in the malignant group (P<0.05). Conclusion: Detection of CK19 mRNA can be a promising diagnostic marker in differential diagnosis of benign and malignant pleural effusions

Venture Capitalists, Syndication and Governance in Initial Public Offerings

This paper examines the development of effective boards in venture capital (VC)-backed initial public offerings. It argues that VC-backed IPOs suffer from two sets of agency costs which are related to principal–agent and principal–principal relationships between the founders and members of the VC syndicate. Using a unique sample of 293 entrepreneurial IPOs in the UK it shows that VC syndicates invest in relatively more risky firms. VC-backed IPOs have more independent boards than IPOs with no VC involvement, with board independence being higher in syndicated VC-backed firms. These results are consistent with assumption that these governance factors are used to mitigate agency costs associated with VC involvement in IPO firms. We also find that in syndicated IPOs there is a higher equity presence of passive private equity firms investing alongside VC firms. Copyright Springer 2006