Over recent years hyperpolarization by dissolution dynamic nuclear polarization has become an established technique for studying metabolism in vivo in animal models. Temporal signal plots obtained from the injected metabolite and daughter products, e.g. pyruvate and lactate, can be fitted to compartmental models to estimate kinetic rate constants. Modeling and physiological parameter estimation can be made more robust by consistent and reproducible injections through automation. An injection system previously developed by us was limited in the injectable volume to between 0.6 and 2.4ml and injection was delayed due to a required syringe filling step. An improved MR-compatible injector system has been developed that measures the pH of injected substrate, uses flow control to reduce dead volume within the injection cannula and can be operated over a larger volume range. The delay time to injection has been minimized by removing the syringe filling step by use of a peristaltic pump. For 100μl to 10.000ml, the volume range typically used for mice to rabbits, the average delivered volume was 97.8% of the demand volume. The standard deviation of delivered volumes was 7μl for 100μl and 20μl for 10.000ml demand volumes (mean S.D. was 9 ul in this range). In three repeat injections through a fixed 0.96mm O.D. tube the coefficient of variation for the area under the curve was 2%. For in vivo injections of hyperpolarized pyruvate in tumor-bearing rats, signal was first detected in the input femoral vein cannula at 3-4s post-injection trigger signal and at 9-12s in tumor tissue. The pH of the injected pyruvate was 7.1±0.3 (mean±S.D., n=10). For small injection volumes, e.g. less than 100μl, the internal diameter of the tubing contained within the peristaltic pump could be reduced to improve accuracy. Larger injection volumes are limited only by the size of the receiving vessel connected to the pump.
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http://dx.doi.org/10.1016/j.jmr.2013.10.024 | DOI Listing |
Expert Rev Vaccines
January 2025
Department of Expanded Program on Immunization, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing, China.
Introduction: Pertussis poses a significant threat to infants under six months due to their immature immune systems, limited maternal antibody protection, and constraints in the vaccination schedule. Despite vaccination efforts, this group remains highly susceptible to severe complications. Addressing these challenges is crucial for improving the health outcomes of infants in China.
View Article and Find Full Text PDFPlant Cell Physiol
January 2025
Institute for Chemical Research, Kyoto University, Gokasho, Uji, 611-0011 Kyoto, Japan.
Lotus japonicus-ROOT HAIR LESS1-LIKE1 (LRL1) of Arabidopsis thaliana encodes a basic helix-loop-helix (bHLH) transcription factor (TF) involved in root hair development. Root hair development is regulated by an elaborate transcriptional network, in which GLABRA2 (GL2), a key negative regulator, directly represses bHLH TF genes, including LRL1 and ROOT HAIR DEFECTIVE6 (RHD6). Although RHD6 and its paralogous TFs have been shown to connect downstream to genes involved in cell morphological events such as endomembrane and cell wall modification, the network downstream of LRL1 remains elusive.
View Article and Find Full Text PDFJ Occup Health
January 2025
Department of Occupational and Environmental Health, Faculty of Pharmaceutical Sciences, Tokyo University of Science, Noda, Japan.
Bromopropane was introduced commercially as an alternative to ozone-depleting and global warming solvents. The identification of 1-bromopropane neurotoxicity in animal experiments was followed by reports of human cases of 1-bromopropane toxicity. In humans, the most common clinical features of 1-bromopropane neurotoxicity are decreased sensation, weakness in extremities, and walking difficulties.
View Article and Find Full Text PDFCurr Opin Crit Care
January 2025
Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS).
Purpose Of Review: This narrative review discusses the mechanisms connecting gut dysbiosis to adverse clinical outcomes in critically ill patients and explores potential therapeutic strategies.
Recent Findings: In recent years, the study of microbiota in ICUs has gained attention because of its potential effects on patient outcomes. Critically ill patients often face severe conditions, which can compromise their immune systems and lead to opportunistic infections from bacteria typically harmless to healthy individuals.
JAMA Intern Med
January 2025
Research and Development, Veterans Affairs Puget Sound Health Care System, Seattle, Washington.
Importance: SARS-CoV-2, influenza, and respiratory syncytial virus (RSV) contribute to many hospitalizations and deaths each year. Understanding relative disease severity can help to inform vaccination guidance.
Objective: To compare disease severity of COVID-19, influenza, and RSV among US veterans.
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