Background: It is difficult to design a system to reliably deliver volatile anaesthetics such as halothane or isoflurane to in vitro preparations such as tissues or cells cultures: the very volatility of the drugs means that they can rapidly dissipate from even carefully-prepared solutions. Furthermore, many experiments require the control of other gases (such as oxygen or carbon dioxide) which requires constant perfusion.
New Method: We describe a constant perfusion system that is air-tight (i.e., allows the accurate administration of hypoxic or hypercapnic gas mixtures), in which volatile anaesthetic is delivered via calibrated vaporisers by constant bubbling into the perfusing solution (and continuously monitored for stability by infrared spectroscopy in the headspace above the solution).
Results: We have confirmed the accuracy (i.e., linear relationship of dissolved concentrations with vapour dial settings) and stability (i.e., over time) of the anaesthetic concentrations in solutions in samples taken from the bottles into which anaesthetic is bubbled, and from samples taken from the tissue perfusion bath, using gas chromatrography-mass spectrometry (GC-MS).
Conclusions: It is possible to deliver volatile anaesthetics in accurate concentrations to cell/tissue preparations whilst adjusting ambient air composition rapidly, stable over sustained time periods.
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http://dx.doi.org/10.1016/j.jneumeth.2015.11.002 | DOI Listing |
Background: Previously, a depth of anesthesia bispectral index (BIS™) <45 was considered lowand found to have no clinical benefit. A BIS <35 was considered very low and was not only without evident clinical benefit but also associated with a greater risk of postoperative delirium. We considered the association between BIS and the anesthetic dose of inhalational agents, quantified using the minimum alveolar concentration (MAC) fraction, which was the patient's end-tidal inhalational agent concentration divided by the agent's altitude- and age-adjusted minimum alveolar percentage concentration.
View Article and Find Full Text PDFACS Sens
January 2025
School of Materials Science and Engineering, Tongji University, Shanghai 201804, P. R. China.
Visual, sensitive, and selective detection of carcinogenic substances is highly desired in portable health protection and practical medicine production. However, achieving this goal presents significant challenges with the traditional single-mode sensors reported so far, as they have limited sensing mechanisms and provide only a single output signal. Here, we report an effective optical and electrical dual-mode sensor for the visual, sensitive, and selective detection of -nitrosodiethylamine (NDEA), a typical volatile carcinogenic substance, leveraging the synergy of ionic liquid-doped liquid crystals (IL-LC).
View Article and Find Full Text PDFIndian J Med Res
November 2024
Department of Receptor Biology and Tumor Metastasis, Chittaranjan National Cancer Institute, Kolkata, India.
Background & objectives The choice of anesthetic for better perioperative conservation of immune responses has always been contentious. This study investigated the differential impact of the intravenous anesthetic, propofol, and the volatile anesthetic, isoflurane on the T cell immune responses, if any, among individuals going through perioperative breast cancer. Methods Perioperative blood samples (preoperative, intraoperative and postoperative) collected from participants with breast cancer in two arms namely isoflurane arm (n=50) and the propofol arm (n=50) were analyzed for T cell immune response using flow cytometry and ELISA.
View Article and Find Full Text PDFCommun Med (Lond)
December 2024
Rostock Medical Breath Research Analytics and Technologies (ROMBAT), Department of Anesthesiology, Intensive Care Medicine and Pain Therapy, Rostock University Medical Center, Rostock, Germany.
Background: Menopause driven decline in estrogen exposes women to risk of osteoporosis. Detection of early onset and silent progression are keys to prevent fractures and associated burdens.
Methods: In a discovery cohort of 120 postmenopausal women, we combined repeated quantitative pulse-echo ultrasonography of bone, assessment of grip strength and serum bone markers with mass-spectrometric analysis of exhaled metabolites to find breath volatile markers and quantitative cutoff levels for osteoporosis.
NeuroSci
December 2024
Department of Palliative Medicine, Poznan University of Medical Sciences, 61-701 Poznań, Poland.
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