Combining proton and phosphorus magnetic resonance spectroscopy offers a unique opportunity to study the oxidative and glycolytic components of metabolism in working muscle. This paper presents a 7 T proton calf coil design that combines dipole and loop elements to achieve the high performance necessary for detecting metabolites with low abundance and restricted visibility, specifically lactate, while including the option of adding a phosphorus array. We investigated the transmit, receive, and parallel imaging performance of three transceiver dipoles with six pair-wise overlap-decoupled standard or twisted pair receive-only coils. With a higher SNR and more efficient transmission decoupling, standard loops outperformed twisted pair coils. The dipoles with standard loops provided a four-fold-higher image SNR than a multinuclear reference coil comprising two proton channels and 32% more than a commercially available 28-channel proton knee coil. The setup enabled up to three-fold acceleration in the right-left direction, with acceptable g-factors and no visible aliasing artefacts. Spectroscopic phantom measurements revealed a higher spectral SNR for lactate with the developed setup than with either reference coil and fewer restrictions in voxel placement due to improved transmit homogeneity. This paper presents a new use case for dipoles and highlights their advantages for the integration in multinuclear calf coils.
- MeSH
- fantomy radiodiagnostické * MeSH
- kosterní svaly * diagnostické zobrazování chemie MeSH
- kyselina mléčná chemie metabolismus MeSH
- lidé MeSH
- magnetická rezonanční spektroskopie metody MeSH
- magnetická rezonanční tomografie * metody MeSH
- poměr signál - šum MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Metabolic transformation of cancer cells leads to the accumulation of lactate and significant acidification in the tumor microenvironment. Both lactate and acidosis have a well-documented impact on cancer progression and negative patient prognosis. Here, we report that cancer cells adapted to acidosis are significantly more sensitive to oxidative damage induced by hydrogen peroxide, high-dose ascorbate, and photodynamic therapy. Higher lactate concentrations abrogate the sensitization. Mechanistically, acidosis leads to a drop in antioxidant capacity caused by a compromised supply of nicotinamide adenine dinucleotide phosphate (NADPH) derived from glucose metabolism. However, lactate metabolism in the Krebs cycle restores NADPH supply and antioxidant capacity. CPI-613 (devimistat), an anticancer drug candidate, selectively eradicates the cells adapted to acidosis through inhibition of the Krebs cycle and induction of oxidative stress while completely abrogating the protective effect of lactate. Simultaneous cell treatment with tetracycline, an inhibitor of the mitochondrial proteosynthesis, further enhances the cytotoxic effect of CPI-613 under acidosis and in tumor spheroids. While there have been numerous attempts to treat cancer by neutralizing the pH of the tumor microenvironment, we alternatively suggest considering tumor acidosis as the Achilles' heel of cancer as it enables selective therapeutic induction of lethal oxidative stress.
- MeSH
- acidóza patofyziologie MeSH
- antitumorózní látky farmakologie MeSH
- citrátový cyklus účinky léků MeSH
- energetický metabolismus MeSH
- fyziologická adaptace MeSH
- glukosa metabolismus MeSH
- glykolýza MeSH
- kapryláty farmakologie MeSH
- koncentrace vodíkových iontů MeSH
- kyselina mléčná metabolismus MeSH
- lidé MeSH
- mitochondrie účinky léků metabolismus patologie MeSH
- nádorové buňky kultivované MeSH
- nádorové mikroprostředí * MeSH
- nádory farmakoterapie metabolismus patologie MeSH
- oxidační stres MeSH
- sulfidy farmakologie MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
D-laktátová acidóza reprezentuje zriedkavú formu metabolickej acidózy, ktorá sa vyskytuje najčastejšie u pacientov so syndrómom krátkeho čreva. Ide o závažnú, niekedy až život ohrozujúcu komplikáciu. Príčinou je akumulácia D-laktátu v organizme, ktorý vzniká v nadmernom množstve fermentáciou nevstrebaných sacharidov mikrobiotou hrubého čreva. Predominantne býva postihnutý nervový systém, z čoho vyplýva aj klinická manifestácia. V klinickom obraze dominuje široká škála nešpecifických neurologických príznakov. Ochorenie sa môže niekedy manifestovať somnolenciou až kómou. Z aspektu laboratórnej diagnostiky ochorenie charakterizuje ťažká metabolická acidóza so zvýšenou aniónovou medzerou. V tejto kazuistike prezentujeme ojedinelý prípad 54-ročnej ženy s Crohnovou chorobou a syndrómom krátkeho čreva, ktorá bola v krátkom čase opakovane hospitalizovaná pre recidívu ťažkej metabolickej acidózy so závažnou poruchou vedomia. Na základe zhodnotenia anamnestických údajov, klinického obrazu a laboratórnych vyšetrení bola pacientke diagnostikovaná D-laktátová acidóza. V diskusii rozoberáme jednotlivé kroky, ktoré viedli k tejto diagnóze a porovnávame našu skúsenosť s údajmi vo svetovej literatúre.
D-lactic acidosis represents a rare form of metabolic acidosis that occurs most commonly in patients with short bowel syndrome. This is a serious, sometimes life-threatening complication. The cause is the accumulation of D-lactate in the body, which is formed in excessive amounts by fermentation of unabsorbed carbohydrates by the intestinal microbiota. The nervous system is predominantly affected, which also results in clinical manifestations. The clinical picture is dominated by a wide range of non-specific neurological symptoms. The disease can sometimes manifest as somnolence to coma. From the aspect of laboratory diagnostics, the disease is characterized by severe metabolic acidosis with an increased anion gap. In this case report, we present a unique case of a 54-year-old woman with Crohn's disease and short bowel syndrome who in a short time was repeatedly hospitalized for recurrence of severe metabolic acidosis with severe impaired consciousness. Based on the evaluation of anamnestic data, clinical picture and laboratory tests, the patient was diagnosed with D-lactic acidosis. In the discussion we discuss the individual steps that led to this diagnosis and compare our experience with data in the world literature.
- MeSH
- acidóza laktátová * diagnóza etiologie terapie MeSH
- Crohnova nemoc komplikace MeSH
- kyselina mléčná metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- metabolické nemoci mozku komplikace MeSH
- péče o pacienty v kritickém stavu MeSH
- poruchy vědomí MeSH
- syndrom krátkého střeva * komplikace MeSH
- výsledek terapie MeSH
- Check Tag
- lidé středního věku MeSH
- lidé MeSH
- ženské pohlaví MeSH
- Publikační typ
- kazuistiky MeSH
BACKGROUND: Inadequate blood supply is one of the major risk factors for anastomotic leak after low anterior rectal resection. Early detection of ischemia might predict complicated healing and enable anastomotic salvage, which is associated with better outcomes. A microdialysis offers a real-time evaluation of adequate bowel perfusion through monitoring of tissue metabolism. In this experimental study, we assessed the role of microdialysis in detecting early ischemia after colorectal anastomosis. MATERIALS AND METHODS: Colorectal anastomosis was performed in six miniature pigs. A microdialysis catheter was placed on the bowel serosa 5 mm proximal to the anastomosis. Metabolic changes were monitored hourly before and after initiating ischemia, which was induced by ligation of the inferior mesenteric artery and skeletonization of the mesocolon. RESULTS: Significant increase in tissue levels of lactate was detected after 60 min of ischemia (13.6 [10.4-16.1] versus 6.75 [1.8-9.6] mmol/L at baseline; P < 0.005). The lactate/pyruvate ratio increased accordingly. The concentration of glycerol increased significantly after 2 hours-from a baseline value of 29.5 (3-84) to 125 (79-201) mmol/L (P < 0.005). The decrease in glucose levels was also significant after 60 minutes-0 (0-0.2) versus 4.7 (3.3-6.8) mmol/L at baseline. However, its values started to decline before ischemia. CONCLUSIONS: Surface microdialysis can detect ischemic changes early and may be a promising method in postoperative monitoring of colorectal anastomosis.
- MeSH
- anastomóza chirurgická * škodlivé účinky MeSH
- glycerol metabolismus MeSH
- ischemie * MeSH
- krevní glukóza analýza MeSH
- kyselina mléčná metabolismus MeSH
- mikrodialýza * metody MeSH
- miniaturní prasata MeSH
- pooperační komplikace * MeSH
- prasata MeSH
- zvířata MeSH
- Check Tag
- mužské pohlaví MeSH
- ženské pohlaví MeSH
- zvířata MeSH
In evolution, genes survived that could code for metabolic pathways, promoting long term survival during famines or fasting when suffering from trauma, disease or during physiological growth. This requires utilization of substrates, already present in some form in the body. Carbohydrate stores are limited and to survive long, their utilization is restricted to survival pathways, by inhibiting glucose oxidation and glycogen synthesis. This leads to insulin resistance and spares muscle protein, because being the main supplier of carbon for new glucose production. In these survival pathways, part of the glucose is degraded in glycolysis in peripheral (muscle) tissues to pyruvate and lactate (Warburg effect), which are partly reutilized for glucose formation in liver and kidney, completing the Cori-cycle. Another part of the glucose taken up by muscle contributes, together with muscle derived amino acids, to the production of substrates consisting of a complete amino acid mix but extra non-essential amino acids like glutamine, alanine, glycine and proline. These support cell proliferation, matrix deposition and redox regulation in tissues, specifically active in host response and during growth. In these tissues, also glucose is taken up delivering glycolytic intermediates, that branch off and act as building blocks and produce reducing equivalents. Lactate is also produced and released in the circulation, adding to the lactate released by muscle in the Cori-cycle and completing secondary glucose cycles. Increased fluxes through these cycles lead to modest hyperglycemia and hyperlactatemia in states of healthy growth and disease and are often misinterpreted as induced by hypoxia.
- MeSH
- glukosa metabolismus MeSH
- glykolýza fyziologie MeSH
- játra metabolismus MeSH
- kosterní svaly metabolismus MeSH
- kyselina mléčná metabolismus MeSH
- kyselina pyrohroznová metabolismus MeSH
- ledviny metabolismus MeSH
- lidé MeSH
- zvířata MeSH
- Check Tag
- lidé MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- přehledy MeSH
Strains of Limosilactobacillus reuteri are used as starter and bioprotective cultures and contribute to the preservation of food through the production of fermentation metabolites lactic and acetic acid, and of the antimicrobial reuterin. Reuterin consists of acrolein and 3-hydroxypropionaldehyde (3-HPA), which can be further metabolized to 1,3-propanediol and 3-hydroxypropionic acid (3-HP). While reuterin has been the focus of many investigations, the contribution of 3-HP to the antimicrobial activity of food related reuterin-producers is unknown. We show that the antibacterial activity of 3-HP was stronger at pH 4.8 compared to pH 5.5 and 6.6. Gram-positive bacteria were in general more resistant against 3-HP and propionic acid than Gram-negative indicator strains including common food pathogens, while spoilage yeast and molds were not inhibited by ≤ 640 mM 3-HP. The presence of acrolein decreased the minimal inhibitory activity of 3-HP against E. coli indicating synergistic antibacterial activity. 3-HP was formed during the growth of the reuterin-producers, and by resting cells of L. reuteri DSM 20016. Taken together, this study shows that food-related reuterin producers strains synthesize a second antibacterial compound, which might be of relevance when strains are added as starter or bioprotective cultures to food products.
- MeSH
- antiinfekční látky chemie metabolismus farmakologie MeSH
- Bacteria účinky léků růst a vývoj MeSH
- fermentace MeSH
- glyceraldehyd analogy a deriváty chemie metabolismus MeSH
- glycerol metabolismus MeSH
- koncentrace vodíkových iontů MeSH
- kyselina mléčná analogy a deriváty chemie metabolismus farmakologie MeSH
- kyselina octová metabolismus MeSH
- Lactobacillaceae chemie růst a vývoj metabolismus MeSH
- potravinářská mikrobiologie MeSH
- propan chemie metabolismus MeSH
- stabilita léku MeSH
- Publikační typ
- časopisecké články MeSH
Two enantiomers of lactic acid exist. While L-lactic acid is a common compound of human metabolism, D-lactic acid is produced by some strains of microorganism or by some less relevant metabolic pathways. While L-lactic acid is an endogenous compound, D-lactic acid is a harmful enantiomer. Exposure to D-lactic acid can happen by various ways including contaminated food and beverages and by microbiota during some pathological states like short bowel syndrome. The exposure to D-lactic acid cannot be diagnosed because the common analytical methods are not suitable for distinguishing between the two enantiomers. In this review, pathways for D-lactic acid, pathological processes, and diagnostical and analytical methods are introduced followed by figures and tables. The current literature is summarized and discussed.
INTRODUCTION: Cardiogenic shock complicating acute myocardial infarction has a very high mortality. Our present study focuses on serial measurement of lactate during admission due to cardiogenic shock and the prognostic effect of lactate and a relative change in lactate in patients after admission and the institution of intensive care treatment. METHODS AND RESULTS: This is a secondary analysis of the CardShock study. Data on lactate at baseline were available on 217 of 219 patients.In the study population, the median baseline lactate was 2.8 mmol/L (min-max range, 0.5-23.1 mmol/L).At admission, lactate was predictive of 30-day mortality with an adjusted Hazard ratio (HR) of 1.20 mmol/L (95% confidence interval, CI 1.14-1.27). Within the first 24 h of admission, baseline lactate remained predictive of 30-day mortality. Lactate at 6 h had a HR of 1.14 (95% CI 1.06-1.24) and corresponding values at 12 and 24 h had a HR of 1.10 (1.04-1.17), and of HR 1.19 (95% CI 1.07-1.32), respectively. A 50% reduction in lactate within 6 h resulted in a HR of 0.82 (95% CI 0.72-0.94). Corresponding hazard ratios at 12 and 24 h, were 0.87 (95% CI 0.76-0.98) and 0.74 (95% CI 0.60-0.91), respectively. CONCLUSION: The main findings of the present study are that baseline lactate is a powerful predictor of 30-day mortality, lactate at 6, 12, and 24 h after admission are predictors of 30-day mortality, and a relative change in lactate is a significant predictor of survival within the first 24 h after instituting intensive care treatment adding information beyond the information from baseline values.
- MeSH
- dospělí MeSH
- hemodynamika MeSH
- kardiogenní šok metabolismus mortalita MeSH
- kyselina mléčná metabolismus MeSH
- lidé středního věku MeSH
- lidé MeSH
- multivariační analýza MeSH
- proporcionální rizikové modely MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- Check Tag
- dospělí MeSH
- lidé středního věku MeSH
- lidé MeSH
- mužské pohlaví MeSH
- senioři nad 80 let MeSH
- senioři MeSH
- ženské pohlaví MeSH
- Publikační typ
- časopisecké články MeSH
- MeSH
- kyselina mléčná analýza metabolismus MeSH
- lidé MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- směrnice pro lékařskou praxi MeSH
Lactic acid and its anion lactate are known as metabolic waste products of bacterial fermentation and anaerobic muscle work. However, during the last 10 years of research, much evidence of their role in physiological reg- ulations of human organism has been accumulated. This review describes their role in metabolic adaptation of muscle and fat tissues, their stimulating effect on regeneration and reparation, double-edge function in the immune response, signaling role in the central nervous system, and modulatory function in humoral regulations. The review also describes their potential applications in acute medicine and in the prevention of chronic diseases.
