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Glycolysis at 75: Is it time to tweak the first elucidated metabolic pathway in history?

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889195862 Year: Pages: 126 DOI: 10.3389/978-2-88919-586-2 Language: English
Publisher: Frontiers Media SA
Subject: Nutrition and Food Sciences --- Medicine (General) --- Neurology --- Science (General)
Added to DOAB on : 2016-03-10 08:14:32
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Glycolysis, the pathway of enzymatic reactions responsible for the breakdown of glucose into two trioses and further into pyruvate or lactate, was elucidated in 1940. For more than seven decades, it has been taught precisely the way its sequence was proposed by Embden, Meyerhof and Parnas. Accordingly, two outcomes of this pathway were proposed, an aerobic glycolysis, with pyruvate as its final product, and an anaerobic glycolysis, identical to the aerobic one, except for an additional reaction, where pyruvate is reduced to lactate. Several studies in the 1980s have shown that both muscle and brain tissues can oxidize and utilize lactate as an energy substrate, challenging this monocarboxylate’s reputation as a useless end-product of anaerobic glycolysis. These findings were met with great skepticism about the idea that lactate could be playing a role in bioenergetics. In the past quarter of a century monocarboxylate transporters (MCTs) were identified and localized in both cellular and mitochondrial membranes. A lactate receptor has been identified. Direct and indirect evidence now indicate that the enzyme lactate dehydrogenase (LDH) resides not only in the cytosol, as part of the glycolytic pathway machinery, but also in the mitochondrial outer membrane. The mitochondrial form of the enzyme oxidizes lactate to pyruvate and concomitantly produces the reducing agent NADH. These findings have shed light on a major drawback of the originally proposed aerobic version of the glycolytic pathway i.e., its inability to regenerate NAD+, as opposed to anaerobic glycolysis that features the cyclical ability of regenerating NAD+ upon pyruvate reduction to lactate by the cytosolic form of LDH. The malate-aspartate shuttle (MAS), a major redox shuttle in the brain, was proposed as an alternative pathway for NAD+ generation for aerobic glycolysis. Nonetheless, would MAS really be necessary for that function if glycolysis always proceeds to the end-products, lactate and NAD+? An additional dilemma the originally proposed aerobic glycolysis presents has to do with the glycolytic pathway of erythrocytes, which despite its highly aerobic environment, always produces lactate as its end-product. It is time to reexamine the original, dogmatic separation of glycolysis into two distinct pathways and put to test the hypothesis of a unified, singular pathway, the end-product of which is lactate, the real substrate of the mitochondrial TCA cycle.

Transcellular Cycles Underlying Neurotransmission

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889196548 Year: Pages: 105 DOI: 10.3389/978-2-88919-654-8 Language: English
Publisher: Frontiers Media SA
Subject: Science (General) --- Neurology
Added to DOAB on : 2016-08-16 10:34:25
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Synaptic transmission demands the operation of a highly specialized metabolic machinery involving the transfer of metabolites and neurotransmitters between neurons, astrocytes and microvessels. In the last years, important advances have occurred in our understanding of the mechanisms underlying cerebral activation, neuroglial coupling and the associated neurovascular response. Briefly, exacerbated oxygen consumption in stimulated neurons is thought to trigger glycolytic lactate and glucose transfer from astrocytes which, in turn, obtain these fuels from the microvasculature. Neurotransmitter release is made possible by a combination of transcellular cycles exchanging metabolites between these three compartments, returning eventually the synapsis to its pre-firing situation in the resting periods. In spite of the enormous progresses achieved in recent years, the drivers determining the predominant direction of the fluxes, their quantitative contribution and their energy requirements, have remained until today incompletely understood, more particularly under the circumstances prevailing in vivo. In many instances, progress derived from the implementation of novel methodological approaches including advanced neuroimaging and neurospectroscopy methods. As a consequence, literature in the field became vast, diverse and spread within journals of different specialities. The e-book "Transcellular cycles underlying neurotransmission" aims to summaryze in a single volume, recent progress achieved in hypothesis, methods and interpretations on the trafficking of metabolites between neurons and glial cells, and the associated mechanisms of neurovascular coupling.

Cell Stress, Metabolic Reprogramming, and Cancer

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Book Series: Frontiers Research Topics ISSN: 16648714 ISBN: 9782889455652 Year: Pages: 68 DOI: 10.3389/978-2-88945-565-2 Language: English
Publisher: Frontiers Media SA
Subject: Medicine (General) --- Oncology
Added to DOAB on : 2019-01-23 14:53:43
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The present eBook presents one review, five mini-reviews, and an opinion article on the achievements and perspectives of studies on important aspects of cancer cell metabolic reprogramming whose mechanisms and regulation are still largely elusive. It also sheds light on certain novel functional components, which rewires cell metabolism in tumor transformation.

Environmental Enrichment of Pigs

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ISBN: 9783039280780 9783039280797 Year: Pages: 174 DOI: 10.3390/books978-3-03928-079-7 Language: English
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Animal Sciences
Added to DOAB on : 2020-04-07 23:07:08
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Pigs have a strong motivation to explore and root. In conventional pig husbandry systems, this need is difficult to fulfil, unless adequate enrichment materials are provided. This book summarises how enrichment strategies for pigs have evolved over the last few decades in different countries and provides a vast array of possibilities to enhance the exploratory needs of pigs. The role of enrichment material on avoidance of tail biting outbreaks or as an element triggering positive emotions in pigs is also discussed.

Genetic and Epigenetic Modulation of Cell Functions by Physical Exercise

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ISBN: 9783039284801 / 9783039284818 Year: Pages: 170 DOI: 10.3390/books978-3-03928-481-8 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Science (General) --- Biology --- Genetics
Added to DOAB on : 2020-06-09 16:38:57
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From an evolutionary perspective, our species has relied upon physical activity for most of its history to survive and has had to escape from predators, to scavenge for food, and to use physique to work or build necessary means for everyday life. Physical activity has been part of our evolution and progress since the very beginning and, consequently, our entire body has been programmed to be active physically. In the last 20 years, scientific research has increasingly shown that our ancient survival principle has beneficial effects not only on the cells and organs involved in physical activities but on the metabolism of the entire organism, influencing the homeostasis and integration of all bodily functions, likely stimulating the production of hormones and other regulatory molecules, with each affecting vital signalling pathways. Most of the web of factors involved in molecular signalling upon exercise are suspected to be centrally controlled by the brain, which has been reported to be deeply modified by physical activity. Such complexity requires a multifaceted approach to shed light on the molecular interactions that occur between physical activity and its outcome at a cellular level.

Advances in Mucoadhesive Polymers and Formulations for Transmucosal Drug Delivery

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ISBN: 9783039287529 / 9783039287536 Year: Pages: 206 DOI: 10.3390/books978-3-03928-753-6 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Medicine (General) --- Therapeutics
Added to DOAB on : 2020-06-09 16:38:57
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Mucoadhesive polymers are widely used in the design of dosage forms for transmucosal drug delivery to the eye, respiratory, gastrointestinal and reproductive tracts. These routes of drug administration offer a number of advantages including improved drug bioavailability, reduced frequency of administration, and the avoidance for the use of injections.

Keywords

furosemide --- electrospinning --- hydroxypropyl cellulose --- poly (vinylpyrrolidone) --- storage and loss moduli --- scanning electron microscopic images --- gellan gum --- pectin --- resveratrol --- mucoadhesive microspheres --- cytotoxicity --- in vitro permeability --- Caco-2 cells --- triple co-culture model --- Carbopol --- clobetasol --- Eudragit® E PO --- interpolyelectrolyte complex --- mucoadhesion --- oral lichen planus --- oral lyophilisates --- maltodextrin --- resuspendibility --- chitosan --- acrylated chitosan --- nanoparticles --- mucoadhesion --- mucosal membranes --- mucoadhesive polymers --- retention --- buccal mucosa drug delivery --- cyclodextrins --- films --- l-arginine --- mucoadhesive polymer --- omeprazole --- paediatric --- clotrimazole --- liposphere --- alkyl lactate --- xanthan gum --- Candida albicans --- mucoadhesion --- poly(2-ethyl-2-oxazoline) --- Carbopol® --- mucoadhesion --- interpolymer complexes --- thiolated hyaluronic acid --- hydrogel --- mucoadhesive --- biocompatibility --- controlled release --- drug delivery --- wound healing --- pluronic f127 --- thermoresponsive polymers --- thermogelling polymers --- detachment force --- rheology --- texture profile analysis --- chitosan derivatives --- mucosal drug delivery --- mucoadhesion --- trimethyl chitosan --- thiolated chitosan --- chitosan-catechol --- acrylated chitosan --- nanoparticles --- pioglitazone --- PLGA-PEG --- transmucosal permeations --- Alzheimer’s disease

Treatment Strategies and Survival Outcomes in Breast Cancer

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ISBN: 9783039287581 / 9783039287598 Year: Pages: 264 DOI: 10.3390/books978-3-03928-759-8 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Medicine (General) --- Internal medicine
Added to DOAB on : 2020-06-09 16:38:57
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Treatment strategies for breast cancer are wide-ranging and often based on a multi-modality approach, depending on the stage and biology of the tumour and the acceptance and tolerance of the patient. They may include surgery, radiotherapy, and systemic therapy (endocrine therapy, chemotherapy, and targeted therapy). Advances in technologies such as oncoplastic surgery, radiation planning and delivery, and genomics, and the development of novel systemic therapy agents alongside their evaluation in ongoing clinical trials continue to strive for improvements in outcomes. In this Special Issue, we publish a collection of studies looking at all forms of therapeutic strategies for early and advanced breast cancer, focusing on their outcomes, notably survival.

Keywords

advanced breast cancer --- metastatic --- chemotherapy --- antihormone therapy --- HER2 c-erbB2 --- HER2/neu --- trastuzumab --- pertuzumab --- T-DM1 --- lapatinib --- LKB1 --- Breast Cancer --- Older women --- Metformin --- Endocrine therapy --- breast cancer --- breast-conserving therapy --- mastectomy --- outcome --- comparative effectiveness --- metastatic breast cancer --- liquid biopsy --- cell-free DNA --- next-generation sequencing --- circulating tumor cells --- overdiagnosis --- mammography screening --- invasive breast cancer --- zero-inflated Poisson regression model --- breast cancer --- stage IV --- incidence --- tumor biology --- NCDB --- SEER --- Src kinase --- basal-like breast cancer --- cMet --- breast cancer --- radiotherapy --- lymph-node ratio --- disease-free survival --- physical activity --- breast cancer survivors --- physical function --- social well-being --- exercise characteristics --- APOBEC3B --- gene expression --- breast cancer --- ductal carcinoma in situ --- infiltrating breast cancer --- PIK3CA --- ERCC1 --- anthracycline resistance --- taxane sensitivity --- breast cancer --- colorectal cancer --- relative survival --- older patients --- geriatric oncology --- cancer treatment --- metastatic breast cancer --- lactate dehydrogenase --- serum biomarker --- LDH --- monitoring metastatic breast cancer --- palbociclib --- ribociclib --- abemaciclib --- fulvestrant --- aromatase inhibitors --- metastatic breast cancer --- contralateral prophylactic mastectomy --- contralateral breast cancer --- BRCA --- CHEK2 --- PALB2 --- ATM --- mutation carriers --- family history --- survival --- breast cancer --- young women --- histone deacetylase --- HDAC5 inhibitors --- LMK-235 --- breast cancer --- cyclin E --- older patients --- biomarker --- tumor biology --- prognosis --- survival --- n/a

Marine Chitin 2019

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ISBN: 9783039360727 / 9783039360734 Year: Pages: 288 DOI: 10.3390/books978-3-03936-073-4 Language: eng
Publisher: MDPI - Multidisciplinary Digital Publishing Institute
Subject: Medicine (General) --- Therapeutics
Added to DOAB on : 2020-06-09 16:38:57
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In 2019, we sent out a call for submissions to a Special Issue of Marine Drugs entitled “Marine Chitin 2019”, and we are pleased that this issue has now been published. Over 16 high-impact papers were included in this issue, which we now plan to publish as a book. In addition, we now seek to publish a further Special Issue of Marine Drugs, “Marine Chitin 2020–2021”. As before, we plan to produce an authoritative and exciting issue that will encompass breakthroughs in scientific and industrial chitin and chitosan research. Significant advances in chitin and chitosan research have been made since the 1970s, and current overviews in recent publications involving chitin and chitosan research advances are in need of an update.

Keywords

chitosan --- cytotoxicity --- polymer film --- sodium carbonate --- soluble chitosan complex --- chitin --- chitosan --- protease --- chitinase --- chitosan oligomers --- chitooligosaccharides --- anti-inflammatory action --- RAW264.7 macrophage --- chitosan oleate salt --- amphiphilic polymer --- PLGA --- nanoparticles --- mucoadhesion --- Caco-2 cell culture --- nile red --- curcumin --- chitooligosaccharide --- immunostimulatory activity --- RAW 264.7 cells --- mitogen-activated protein kinases (MAPK) --- phosphoinositide 3-kinases (PI3K)/Akt --- chitosan oligosaccharides --- streptomycin --- Pseudomonas aeruginosa --- biofilms --- conjugation --- chitin --- marine sponges --- scaffolds --- Aplysina archeri --- express method --- bromotyrosines --- crude oil --- blood --- methylene blue --- chitin --- chitosan --- Paenibacillus --- chitosanase --- chitosan oligomers --- ?-glucosidase inhibitor --- antioxidant --- Polybius henslowii --- marine resources --- chitosan --- chitooligosaccharides --- antifungal activity --- antioxidant activity --- chitin --- collagen --- electrospinning --- mechanical property --- 2D correlation spectroscopy --- polymorph --- chitosan lactate --- chitosan tartrate --- chitosan citrate --- Eudragit® S100 --- layer-by-layer film --- mucoadhesive film --- Tenofovir controlled release --- pH responsive release --- vaginal preexposure prophylaxis --- HIV sexual transmission --- chitin --- chitosan --- wound treatment --- derivatization --- nanocomposites --- chitosan --- antibacterial activity --- Clostridium perfringens --- pork sausage --- chitin --- chitosan --- chitooligosaccharides --- enzymatic modification --- biotechnology --- chitinase --- chitosanase --- lytic polysaccharide monooxygenase --- chitin deacetylase --- chitosan-coated liposomes --- chitosan hydrogel --- mucoadhesion --- vaginal infections --- antibacterial activity --- Staphylococcus epidermidis --- Staphylococcus aureus --- chitin --- roller compaction --- ball milling --- direct compression --- compression work --- crushing strength --- Hausner ratio --- Kawakita analysis --- bulk density --- dissolution

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