AIMS/HYPOTHESIS: The aim of this substudy (Eudra CT No:2019-001997-27)was to assess ATB availability in patients with infected diabetic foot ulcers(IDFUs)in the context of microcirculation and macrocirculation status. METHODS: For this substudy, we enrolled 23 patients with IDFU. Patients were treated with boluses of amoxicillin/clavulanic acid(AMC)(12patients) or ceftazidime(CTZ)(11patients). After induction of a steady ATB state, microdialysis was performed near the IDFU. Tissue fluid samples from the foot and blood samples from peripheral blood were taken within 6 hours. ATB potential efficacy was assessed by evaluating the maximum serum and tissue ATB concentrations(Cmax and Cmax-tissue)and the percentage of time the unbound drug tissue concentration exceeds the minimum inhibitory concentration (MIC)(≥100% tissue and ≥50%/60% tissue fT>MIC). Vascular status was assessed by triplex ultrasound, ankle-brachial and toe-brachial index tests, occlusive plethysmography comprising two arterial flow phases, and transcutaneous oxygen pressure(TcPO2). RESULTS: Following bolus administration, the Cmax of AMC was 91.8 ± 52.5 μgmL-1 and the Cmax-tissue of AMC was 7.25 ± 4.5 μgmL-1(P<0.001). The Cmax for CTZ was 186.8 ± 44.1 μgmL-1 and the Cmax-tissue of CTZ was 18.6 ± 7.4 μgmL-1(P<0.0001). Additionally, 67% of patients treated with AMC and 55% of those treated with CTZ achieved tissue fT>MIC levels exceeding 50% and 60%, respectively. We observed positive correlations between both Cmax-tissue and AUCtissue and arterial flow. Specifically, the correlation coefficient for the first phase was r=0.42; (P=0.045), and for the second phase, it was r=0.55(P=0.01)and r=0.5(P=0.021). CONCLUSIONS: Bactericidal activity proved satisfactory in only half to two-thirds of patients with IDFUs, an outcome that appears to correlate primarily with arterial flow.

• Keywords
• antibiotic, diabetic foot, infection, microdialysis, peripheral arterial disease,
• MeSH
• Anti-Bacterial Agents * pharmacokinetics   administration & dosage   therapeutic use   MeSH
• Diabetic Foot * drug therapy   metabolism   MeSH
• Administration, Intravenous MeSH
• Middle Aged MeSH
• Humans MeSH
• Microcirculation * drug effects   MeSH
• Aged MeSH
• Check Tag
• Middle Aged MeSH
• Humans MeSH
• Male MeSH
• Aged MeSH
• Female MeSH
• Publication type
• Journal Article MeSH

Two methods of capillary electrophoresis with contactless conductivity detection have been developed for monitoring the levels of glucose and lactate in clinical samples. The separations are performed in uncoated fused silica capillaries with inner diameter 10 or 20 μm, total length 31.5 cm, length to detector 18 cm, using an Agilent electrophoretic instrument with an integrated contactless conductivity detector. Glucose is determined in optimized background electrolyte, 50 mM NaOH with pH 12.6 and 2-deoxyglucose is used as an internal standard; the determination of lactate is performed in 40 mM CHES/NaOH with pH 9.4 and lithium cations as an internal standard. Both substances are determined in minimal volumes of (1) nutrient media after cell incubation, and (2) microdialysates of human adipose tissue; after dilution and filtration as the only treatment of the sample. The migration time of glucose is 2.5 min and that of lactate is 1.5 min with detection limits at the micromolar concentration level. The developed techniques are suitable for sequential monitoring of glucose and lactate over time during metabolic experiments.

• Keywords
• Capillary electrophoresis, Cell incubation, Contactless conductivity detection, Glucose, Lactate, Microdialysis, Rapid determination,
• MeSH
• Electric Conductivity * MeSH
• Electrophoresis, Capillary methods   MeSH
• Glucose analysis   MeSH
• Calibration MeSH
• Culture Media chemistry   MeSH
• Cells, Cultured MeSH
• Lactic Acid analysis   MeSH
• Humans MeSH
• Microdialysis methods   MeSH
• Adipose Tissue MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Glucose MeSH
• Culture Media MeSH
• Lactic Acid MeSH

Methyltriphenylphosphonium (TPMP) salts have been widely used to measure the mitochondrial membrane potential and the triphenylphosphonium (TPP+) moiety has been attached to many bioactive compounds including antioxidants to target them into mitochondria thanks to their high affinity to accumulate in the mitochondrial matrix. The adverse effects of these compounds on cellular metabolism have been insufficiently studied and are still poorly understood. Micromolar concentrations of TPMP cause a progressive inhibition of cellular respiration in adherent cells without a marked effect on mitochondrial coupling. In permeabilized cells the inhibition was limited to NADH-linked respiration. We found a mixed inhibition of the Krebs cycle enzyme 2-oxoglutarate dehydrogenase complex (OGDHC) with an estimated IC50 3.93 [3.70-4.17] mM, which is pharmacologically plausible since it corresponds to micromolar extracellular concentrations. Increasing the lipophilic character of the used TPP+ compound further potentiates the inhibition of OGDHC activity. This effect of TPMP on the Krebs cycle ought to be taken into account when interpreting observations on cells and mitochondria in the presence of TPP+ derivatives. Compounds based on or similar to TPP+ derivatives may also be used to alter OGDHC activity for experimental or therapeutic purposes.

• MeSH
• Cell Line MeSH
• Citric Acid Cycle drug effects   MeSH
• Citrate (si)-Synthase drug effects   metabolism   MeSH
• Glutamate Dehydrogenase drug effects   metabolism   MeSH
• Isocitrate Dehydrogenase drug effects   metabolism   MeSH
• Ketoglutarate Dehydrogenase Complex antagonists & inhibitors   metabolism   MeSH
• Muscle, Skeletal enzymology   MeSH
• Rats MeSH
• Malate Dehydrogenase drug effects   metabolism   MeSH
• Membrane Potential, Mitochondrial drug effects   MeSH
• Onium Compounds pharmacology   MeSH
• Rats, Wistar MeSH
• Pyruvate Dehydrogenase Complex drug effects   metabolism   MeSH
• Mitochondria, Muscle drug effects   enzymology   MeSH
• Triphenylmethyl Compounds pharmacology   MeSH
• Animals MeSH
• Check Tag
• Rats MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Citrate (si)-Synthase MeSH
• Glutamate Dehydrogenase MeSH
• Isocitrate Dehydrogenase MeSH
• Ketoglutarate Dehydrogenase Complex MeSH
• Malate Dehydrogenase MeSH
• Onium Compounds MeSH
• Pyruvate Dehydrogenase Complex MeSH
• triphenylmethylphosphonium MeSH Browser
• Triphenylmethyl Compounds MeSH