On the Architecture of Starch Granules Revealed by Iodine Binding and Lintnerization. Part 2: Molecular Structure of Lintnerized Starches.

This investigation validated iodine binding in combination with lintnerization for studying the structural nature of the amorphous areas in starch granules. Lintners of four iodine vapor-stained and non-stained amylose-containing starches and their waxy counterparts were analyzed by high-performance anion-exchange chromatography (HPAEC). The composition of the lintners was strongly affected by the absence of amylose in barley and potato starch but not in maize and cassava starch.

On the architecture of starch granules revealed by iodine vapor binding and lintnerization. Part 1: Microscopic examinations.

Structural nature of glucan chains in the amorphous part of granular starch was examined by iodine vapor treatment and lintnerization. Four iodine-stained amylose-containing normal starches and their waxy counterparts were examined under a microscope before, during, and after lintnerization. The presence of amylose retarded the lintnerization rate.

Modification of Pea Starch Digestibility through the Complexation with Gallic Acid via High-Pressure Homogenization.

Pea starch and some legume starches are the side streams of plant-based protein production. Structural modification toward moderate digestibility and desirable functionality is a way to increase the economic values of these side-stream starches. We applied an innovative and sustainable technique, high-pressure homogenization, to alter pea starch structure, which resulted in a high level of complexation with the small phenolic acid molecule, gallic acid, to alter starch digestibility.

Eliminating protein interference when quantifying potato reducing sugars with the miniaturized Somogyi-Nelson assay.

Reducing sugar (RS) quantification is essential in the potato industry because RS content plays a vital role in potato quality, acrylamide formation, post-harvest management, and new variety development. A miniaturized Somogyi-Nelson (SN) analysis can effectively and accurately quantify RS. However, soluble proteins in potatoes interfere with SN analysis.

PD-L1 checkpoint blockade delivered by retroviral replicating vector confers anti-tumor efficacy in murine tumor models.

Immune checkpoint inhibitors (CPIs) are associated with a number of immune-related adverse events and low response rates. We provide preclinical evidence for use of a retroviral replicating vector (RRV) selective to cancer cells, to deliver CPI agents that may circumvent such issues and increase efficacy. An RRV, RRV-scFv-PDL1, encoding a secreted single chain variable fragment targeting PD-L1 can effectively compete with PD-1 for PD-L1 occupancy.

Impacts of Starch and the Interactions Between Starch and Other Macromolecules on Wheat Falling Number.

Wheat with a low falling number (FN) has been particularly prevalent in recent years and has resulted in a loss of more than $140 million in a single year in the wheat industry in the Pacific Northwest of the United States. FN measurement is a standard method for the evaluation of grain α-amylase activity, and a low FN indicates a reduction in hot wholemeal paste viscosity due to sprouting damage. Recent studies show that a low FN may result from a developmental change of starch and adverse effects of non-α-amylase macromolecules on wheat.

Reduction of falling number in soft white spring wheat caused by an increased proportion of spherical B-type starch granules.

A low falling number (FN) in wheat indicates high α-amylase activity associated with poor end-use quality. We hypothesize starch - the substrate of α-amylase, can directly influence hot flour pasting properties and its susceptibility to α-amylase, which further affects viscosity. We examined the structural characteristics of starch in three soft white spring wheat cultivars grown in Idaho in 2013 (normal FN year) and 2014 (low FN year with pre-harvest rains).

Structure and Digestion of Common Complementary Food Starches.

Starch is the major source of dietary glucose for rapid development of children. Starches from various crops naturally differ in molecular structures and properties. Cooking, processing, and storage may change their molecular properties and affect their digestibility and functionality.

Efficient Therapeutic Protein Expression Using Retroviral Replicating Vector with 2A Peptide in Cancer Models.

Toca 511, a retroviral replicating vector (RRV), uses an internal ribosomal entry site (IRES) to express an optimized yeast cytosine deaminase (yCD2), which converts 5-fluorocytosine to 5-fluorouracil. This configuration is genetically stable in both preclinical mouse models and human clinical trials. However, the use of IRES (∼600 bp) restricts choices of therapeutic transgenes due to limits in RRV genome size.

Improvement in the quantification of reducing sugars by miniaturizing the Somogyi-Nelson assay using a microtiter plate.

Measuring reducing sugar is a common practice in carbohydrate research, and the colorimetric assay developed by Somogyi and Nelson has a high sensitivity in a broad concentration range. However, the method is time-consuming when analyzing a large number of samples. In this study, a modified Somogyi-Nelson assay with excellent accuracy and sensitivity was developed using a 96-well microplate.

Accelerating access and scale-up of optimized ART in low-income and middle-income countries: a call for a coordinated end-to-end approach.

Purpose Of Review: To discuss how aligning the collective power of scientists, regulators, drug companies, donors, implementers and advocates to achieve a single goal - accelerating access to simpler, safer, more robust and more affordable HIV treatment - can rapidly advance antiretroviral optimization efforts and enable scale-up.

Recent Findings: Harmonization of traditionally sequential processes can address the delays commonly experienced in introducing new products to low-income and middle-income countries, by facilitating an 'end-to-end' approach that mitigates risk and encourages early planning for all aspects of product introduction.

Summary: Planning with the 'end-in-mind' can facilitate healthy markets, benefit the application of new technologies, and accelerate the development of improved products in parallel (versus traditionally sequential efforts).

Retroviral Replicating Vector Delivery of miR-PDL1 Inhibits Immune Checkpoint PDL1 and Enhances Immune Responses In Vitro.

Tumor cells express a number of immunosuppressive molecules that can suppress anti-tumor immune responses. Efficient delivery of small interfering RNAs to treat a wide range of diseases including cancers remains a challenge. Retroviral replicating vectors (RRV) can be used to stably and selectively introduce genetic material into cancer cells.

Improved Starch Digestion of Sucrase-deficient Shrews Treated With Oral Glucoamylase Enzyme Supplements.

Background And Objective: Although named because of its sucrose hydrolytic activity, this mucosal enzyme plays a leading role in starch digestion because of its maltase and glucoamylase activities. Sucrase-deficient mutant shrews, Suncus murinus, were used as a model to investigate starch digestion in patients with congenital sucrase-isomaltase deficiency.Starch digestion is much more complex than sucrose digestion.

Contribution of the Individual Small Intestinal α-Glucosidases to Digestion of Unusual α-Linked Glycemic Disaccharides.

The mammalian mucosal α-glucosidase complexes, maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI), have two catalytic subunits (N- and C-termini). Concurrent with the desire to modulate glycemic response, there has been a focus on di-/oligosaccharides with unusual α-linkages that are digested to glucose slowly by these enzymes. Here, we look at disaccharides with various possible α-linkages and their hydrolysis.

Extensive Replication of a Retroviral Replicating Vector Can Expand the A Bulge in the Encephalomyocarditis Virus Internal Ribosome Entry Site and Change Translation Efficiency of the Downstream Transgene.

We have developed retroviral replicating vectors (RRV) derived from Moloney murine gammaretrovirus with an amphotropic envelope and an encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES)-transgene cassette downstream of the env gene. During long-term (180 days) replication of the vector in animals, a bulge of 7 adenosine residues (A's) in the J-K bifurcation domain sometimes serially added A's. Therefore, vectors with 4-12 A's in the A bulge in the J-K bifurcation domain were generated, and the impact of the variants on transgene protein expression, vector stability, and IRES sequence upon multiple infection cycles was assessed in RRV encoding yeast-derived cytosine deaminase and green fluorescent protein in vitro.

Learning from the private sector: towards a keener understanding of the end-user for microbicide introduction planning.

Introduction: In planning for the introduction of vaginal microbicides and other new antiretroviral (ARV)-based prevention products for women, an in-depth understanding of potential end-users will be critically important to inform strategies to optimize uptake and long-term adherence. User-centred private sector companies have contributed to the successful launch of many different types of products, employing methods drawn from behavioural and social sciences to shape product designs, marketing messages and communication channels. Examples of how the private sector has adapted and applied these techniques to make decisions around product messaging and targeting may be instructive for adaptation to microbicide introduction.

Branch pattern of starch internal structure influences the glucogenesis by mucosal Nt-maltase-glucoamylase.

To produce sufficient amounts of glucose from food starch, both α-amylase and mucosal α-glucosidases are required. We found previously that the digestion rate of starch is influenced by its susceptibility to mucosal α-glucosidases. In the present study, six starches and one glycogen were pre-hydrolyzed by α-amylase for various time periods, and then further hydrolyzed with the mucosal α-glucosidase, the N-terminal subunit of maltase-glucoamylase (Nt-MGAM), to generate free glucose.

Blockade of type I interferon (IFN) production by retroviral replicating vectors and reduced tumor cell responses to IFN likely contribute to tumor selectivity.

Unlabelled: We developed a Moloney mouse leukemia virus (MLV)-based retroviral replicating vector (RRV), Toca 511, which has displayed tumor specificity in resected brain tumor material and blood in clinical trials. Here, we investigated the interaction between Toca 511 and human host cells, and we show that RRVs do not induce type I interferon (IFN) responses in cultured human tumor cells or cultured human primary cells. However, exogenous type I IFN inhibited RRV replication in tumor cells and induced IFN-regulated genes, albeit at a lower level than in primary cells.

MicroRNA 142-3p attenuates spread of replicating retroviral vector in hematopoietic lineage-derived cells while maintaining an antiviral immune response.

We are developing a retroviral replicating vector (RRV) encoding cytosine deaminase as an anticancer agent for gliomas. Despite its demonstrated natural selectivity for tumors, and other safety features, such a virus could potentially cause off-target effects by productively infecting healthy tissues. Here, we investigated whether incorporation of a hematopoietic lineage-specific microRNA target sequence in RRV further restricts replication in hematopoietic lineage-derived human cells in vitro and in murine lymphoid tissues in vivo.

Mucosal C-terminal maltase-glucoamylase hydrolyzes large size starch digestion products that may contribute to rapid postprandial glucose generation.

Scope: The four mucosal α-glucosidases, which differ in their digestive roles, generate glucose from glycemic carbohydrates and accordingly can be viewed as a control point for rate of glucose delivery to the body. In this study, individual recombinant enzymes were used to understand how α-glucan oligomers are digested by each enzyme, and how intermediate α-amylolyzed starches are hydrolyzed, to elucidate a strategy for moderating the glycemic spike of rapidly digestible starchy foods.

Methods And Results: The C-terminal maltase-glucoamylase (ctMGAM, commonly termed "glucoamylase") was able to rapidly hydrolyze longer maltooligosaccharides, such as maltotetraose and maltopentaose, to glucose.

Maltase-glucoamylase modulates gluconeogenesis and sucrase-isomaltase dominates starch digestion glucogenesis.

Objectives: Six enzyme activities are needed to digest starch to absorbable free glucose; 2 luminal α-amylases (AMY) and 4 mucosal maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI) subunit activities are involved in the digestion. The AMY activities break down starch to soluble oligomeric dextrins; mucosal MGAM and SI can either directly digest starch to glucose or convert the post-α-amylolytic dextrins to glucose. We hypothesized that MGAM, with higher maltase than SI, drives digestion on ad limitum intakes and SI, with lower activity but more abundant amount, constrains ad libitum starch digestion.

Mammalian mucosal α-glucosidases coordinate with α-amylase in the initial starch hydrolysis stage to have a role in starch digestion beyond glucogenesis.

Starch digestion in the human body is typically viewed in a sequential manner beginning with α-amylase and followed by α-glucosidase to produce glucose. This report indicates that the two enzyme types can act synergistically to digest granular starch structure. The aim of this study was to investigate how the mucosal α-glucosidases act with α-amylase to digest granular starch.

Starch source influences dietary glucose generation at the mucosal α-glucosidase level.

The quality of starch digestion, related to the rate and extent of release of dietary glucose, is associated with glycemia-related problems such as diabetes and other metabolic syndrome conditions. Here, we found that the rate of glucose generation from starch is unexpectedly associated with mucosal α-glucosidases and not just α-amylase. This understanding could lead to a new approach to regulate the glycemic response and glucose-related physiologic responses in the human body.