Fasting Healthy Volunteers Research Articles

Pharmacokinetic and Bioequivalence Study of the Two-component Drug Product "Ezetimibe + rosuvastatin" (JSC "Sanofi-aventis group", Russia): Resuts and Experience with the Use of Enzymatic Hydrolysis in the Analysis of Samples

Introduction. As a part of the registration of the drug product a bioequivalence study of the fixed-dose combination "Ezetimibe + rosuvastatin" (JSC "Sanofi-aventis group", Russia) compared with coadministered Ezetrol® (ezetimibe) and Crestor® (rosuvastatin) was conducted with 76 healthy volunteers. Enzymatic hydrolysis was used to evaluate the pharmacokinetics of total ezetimibe. This was the reason for the inclusion of the additional monitored parameters in the validation and analysis.Aim. The purpose of the bioequivalence trial was a comparative study of the pharmacokinetics and evidence of the bioequivalence of the fixed-dose combination "Ezetimibe + rosuvastatin" (ezetimibe + rosuvastatin,tablets, 10 + 40 mg, JSC "Sanofi-aventis group", Russia) compared with coadministrated monocomponent drugs ezetimibe and rosuvastatin in fasting healthy volunteers after a single administration using the described additional parameters for controlling the enzymatic hydrolysis of ezetimibe-glucuronide during the analysis of samples.Materials and methods. To prove bioequivalence, an open label, comparative, randomized, crossover two-period clinical trial was conducted. During the study, blood plasma samples were taken from volunteers, the concentrations of ezetimibe (unconjugated) and total ezetimibe (ezetimibe + ezetimibe-glucuronide) and rosuvastatin in plasma samples were determined by validated HPLC-MS/MS methods. Based on the received data pharmacokinetic and statistical analysis was performed and confidence intervals (CI) for the pharmacokinetic parameters Cmax and AUC0-72 were calculated.Results and discussion. It can be concluded that the studied formulations are bioequivalent in terms of pharmacokinetic parameters of ezetimibe (free) and rosuvastatin. Pharmacokinetic parameters of total ezetimibe were considered as secondary and were not required for the conclusion on bioequivalence. While HPLC-MS/MS analysis of incurred samples, additional control parameters for the enzymatic hydrolysis of ezetimibe-glucuronide made it possible to legitimately reject the results of inaccurate analytical batches.Conclusion. Thus, according to the criteria used in the study, the drugs are proved to be bioequivalent. The described additional parameters for controlling the enzymatic hydrolysis of ezetimibe-glucuronide have been shown to be effective.

Pharmacokinetics and Endocrine Effects of an Oral Dose of D-Pinitol in Human Fasting Healthy Volunteers.

The present study characterizes the oral pharmacokinetics of D-Pinitol, a natural insulin mimetic inositol, in human healthy volunteers (14 males and 11 females). D-Pinitol absorption was studied in (a) subjects receiving a single oral dose of 15 mg/kg (n = 10), or (b) 5 mg/kg pure D-Pinitol (n = 6), and (c) subjects receiving D-Pinitol as part of carbohydrate-containing carob pods-derived syrup with a 3.2% D-Pinitol (Dose of 1600 mg/subject, n = 9). The volunteers received a randomly assigned single dose of either D-Pinitol or carob pod-derived syrup. Blood samples were collected at 0, 15, 30, 45, 60, 90, 120, 180, 240, 360 and 1440 min after intake. Plasma concentration of D-Pinitol was measured and pharmacokinetic parameters obtained. The data indicate that when given alone, the oral absorption of D-Pinitol is dose-dependent and of extended duration, with a Tmax reached after almost 4 h, and a half-life greater than 5 h. When the source of D-Pinitol was a carob pods-derived syrup, Cmax was reduced to 40% of the expected based on the data of D-Pinitol alone, suggesting a reduced absorption probably because of competition with monosaccharide transport. In this group, Tmax was reached before that of D-Pinitol alone, but the estimated half-life remained the same. In the D-Pinitol groups, plasma concentrations of glucose, insulin, glucagon, ghrelin, free fatty acids, and pituitary hormones were additionally measured. A dose of 15 mg/kg of D-Pinitol did not affect glucose levels in healthy volunteers, but reduced insulin and increased glucagon and ghrelin concentrations. D-Pinitol did not increase other hormones known to enhance plasma glucose, such as cortisol or GH, which were surprisingly reduced after the ingestion of this inositol. Other pituitary hormones (gonadotropins, prolactin, and thyroid-stimulating hormone) were not affected after D-Pinitol ingestion. In a conclusion, D-Pinitol is absorbed through the oral route, having an extended half-life and displaying the pharmacological profile of an endocrine pancreas protector, a pharmacological activity of potential interest for the treatment or prevention of insulin resistance-associated conditions.

Single Dose Study Assessing the Pharmacokinetic and Metabolic Profile of Alverine Citrate in Healthy Volunteers.

Alverine citrate is a spasmolytic commonly prescribed in conditions such as irritable bowel syndrome, painful diverticular disease of the colon, and primary dysmenorrhea. While clinical efficacy data on alverine alone or in combination with simethicone is freely available, surprisingly little information regarding the pharmacokinetics and metabolism of alverine can be found in literature. The first HPLC-MS/MS analytical protocol for determination of alverine parent, 4-hydroxy alverine, N-desethyl alverine and 4-hydroxy alverine glucuronide in human plasma was developed and validated. The two validated methods were used for analyzing plasma samples collected during an open label, non-comparative, single dose, one-period, one-treatment, pharmacokinetic and metabolic profile study of Spasmonal® Forte 120 mg hard capsule, conducted in 12 fasting healthy male and female volunteers of Caucasian descent. The study confirmed previous suspicions that parent alverine is subject to high pharmacokinetic variability and also revealed that the metabolic process most susceptible to outlying performance in Caucasians is hydroxylation to the active metabolite 4-hydroxy alverine. Another interesting observation made is that alverine parent accounts for only 3%, whereas total 4-hydroxy alverine (free and conjugated) accounts for 94% of alverine-related moieties in circulation (based on comparisons of total exposure).

Noninvasive monitoring of fibre fermentation in healthy volunteers by analyzing breath volatile metabolites: lessons from the FiberTAG intervention study

ABSTRACT The fermentation of dietary fibre (DF) leads to the production of bioactive metabolites, the most volatile ones being excreted in the breath. The aim of this study was to analyze the profile of exhaled breath volatile metabolites (BVM) and gastrointestinal symptoms in healthy volunteers after a single ingestion of maltodextrin (placebo) versus chitin-glucan (CG), an insoluble DF previously shown to be fermented into short-chain fatty acids (SCFA) by the human microbiota in vitro. Maltodextrin (4.5 g at day 0) or CG (4.5 g at day 2) were added to a standardized breakfast in fasting healthy volunteers (n = 15). BVM were measured using selected ion flow tube mass spectrometry (SIFT-MS) throughout the day. A single ingestion of 4.5 g CG did not induce significant gastrointestinal discomfort. Untargeted metabolomics analysis of breath highlighted that 13 MS-fragments (among 408 obtained from ionizations of breath) discriminated CG versus maltodextrin acute intake in the posprandial state. The targeted analysis revealed that CG increased exhaled butyrate and 5 other BVM – including the microbial metabolites 2,3-butanedione and 3-hydroxybutanone – with a peak observed 6 h after CG intake. Correlation analyses with fecal microbiota (Illumina 16S rRNA sequencing) spotlighted Mitsuokella as a potential genus responsible for the presence of butyric acid, triethylamine and 3-hydroxybutanone in the breath. In conclusion, measuring BMV in the breath reveals the microbial signature of the fermentation of DF after a single ingestion. This protocol allows to analyze the time-course of released bioactive metabolites that could be proposed as new biomarkers of DF fermentation, potentially linked to their biological properties. Trial registration: Clinical Trials NCT03494491. Registered 11 April 2018 – Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT03494491

Raman spectroscopy characterization of the major classes of plasma lipoproteins

Raman spectroscopy has been vastly employed for the characterization of different bio-molecular species spanning from single protein to the in-vivo analysis of tissues. However, despite the huge work done, a detailed description of the Raman spectra acquired from the main classes of plasma lipoproteins is still missing.In this work, we extracted, the major classes of lipoproteins: the triacylglycerol-rich very low density lipoproteins (VLDL); the more cholesterol-rich low density lipoproteins (LDL); and the high density lipoproteins (HDL); from human plasma of six fasting healthy volunteers. The extracted lipoproteins were dried on CaF2 slides and analysed using a 633 nm laser line non-in resonance with the carotenoids present in the sample.The obtained spectra showed peaks relative to the different biomolecules composing lipoproteins: cholesterol, triglycerides, membrane lipids, carotenoids, and apolipoproteins (proteins). The intensity of the peaks from lipids and proteins are well in accordance with the measured composition of lipoproteins; but the information is acquired in a much faster way by Raman spectroscopy. Besides, Raman spectroscopy provides easily information on the levels of carotenoids and unsaturated fatty acid present in the samples.Overall, our data provide a clear comprehension of the Raman spectra from lipoproteins ad suggest that Raman spectroscopy could be a viable approach for the fast characterization of lipoproteins.

Single Dose Bioequivalence Study of Two Rivaroxaban Tablet Formulations, Administered Orally after Being Crushed and Suspended in Apple Puree

The bioavailability of an active substance might be altered when a solid oral dosage form (SODF) is crushed or disintegrated and mixed with fluids or food in order to assist swallowing. In consequence, the current European Medicines Agency (EMA) practice is to request comparative bioavailability testing for bridging safety and efficacy data from a formulation administered whole to the same product administered crushed. Specific criteria for waiving in vivo testing of crushed products are available only for BCS Class I and Class III drugs. Since rivaroxaban is a Class II drug which can be administered crushed and mixed with fluids, any generic formulation has to be tested against the originator in this setting. Therefore, an open label, randomized, single dose, two-period, two-sequence, crossover bioequivalence study with administration of rivaroxaban 10 mg crushed tablets suspended in apple puree was conducted in 24 fasting healthy volunteers. Both rivaroxaban treatments were well tolerated by the study subjects. A standardized, dose efficient and fully reproducible protocol for grinding, mixing and administering investigational medicinal products was developed and applied. Assessment of bioequivalence was based on plasma concentrations of parent rivaroxaban, quantified using a validated HPLC/ MS/MS method. The 90% confidence intervals for Cmax and AUC0-t least square mean T/R ratios were within the bioequivalence acceptance range of 80% to 125%. Results from the present study reinforced the bioequivalence conclusion reached for the same test and reference products following administration of whole tablets in fasting state. No notable changes in bioavailability occurred when rivaroxaban tablets were crushed, immediately dispensed in 70 mL apple puree and quantitatively (entire dose recovered) administered to fasting volunteers.

Target site pharmacokinetics of doxycycline for rosacea in healthy volunteers is independent of the food effect

AimsDoxycycline (DFD‐09) oral capsules 40 mg are approved for the treatment of inflammatory lesions of rosacea. Unlike the food‐induced lowering of doxycycline's peak plasma concentration (Cmax), its exposure under fed conditions in the skin, the drug's target site for rosacea, is unknown. The present study explored the effect of food on the dermal pharmacokinetics of doxycycline.MethodsThe pharmacokinetics of doxycycline in the dermal interstitial fluid (d‐ISF) and plasma of healthy volunteers were assessed in parallel groups under fed (n = 6) and fasting (n = 6) conditions during a 14‐day once‐daily treatment course with doxycycline oral capsules 40 mg (DFD‐09). Sampling of d‐ISF and plasma was performed on days 1, 10 (fasting group d‐ISF only) and 14.ResultsTwelve subjects were randomized, and 11 analysed. No causally drug‐related adverse events occurred. Dermal doxycycline exposures (Cmax and area under the curve) under the fed state were about 30% lower than under the fasting state at day 1 but were similar at steady state. In analogy to skin, plasma exposure showed no between‐group difference at steady state. Accumulation ratios were higher in the skin than in plasma. Correcting for plasma protein binding (~90%), dermal doxycycline exposure was approximately threefold higher than unbound plasma exposure.ConclusionsAt steady state, doxycycline concentrations in the skin of fed and fasting healthy volunteers were comparable. Doxycycline's efficacy in rosacea is possibly due to considerable dermal accumulation of unbound doxycycline and is independent of the effect of food.

Impact of blood cell counts and volumes on glucose concentration in uncentrifuged serum and lithium-heparin blood tubes.

Although it is known that glucose concentration exhibits a time-dependent decay in uncentrifuged serum and lithium-heparin blood tubes, no evidence exists on how this variation may depend on blood cell counts (CBC) and volumes. Venous blood was drawn from 30 non fasting healthy volunteers into three serum and three lithium-heparin tubes. One serum and lithium-heparin tubes were centrifuged within 15 min after collection and glucose was measured with a hexokinase assay. The second and third serum and lithium-heparin tubes were maintained at room temperature for 1 and 2 h after the first tubes were centrifuged. These other tubes were then centrifuged and glucose was measured. CBC was performed in the first lithium-heparin tube, before centrifugation. The mean decrease of glucose was higher in lithium-heparin plasma than in serum (0.33 vs. 0.24 mmol/L/h; p<0.001). Glucose concentration decreased by 7% and 5% per hour in lithium-heparin plasma and serum, respectively. In univariate analysis, the absolute decrease of glucose concentration was associated with sex (higher in men than in women), red blood cell (RBC) count, hematocrit, white blood cell (WBC) count, neutrophils and monocytes in both lithium-heparin plasma and serum. In multivariate analysis, the decrease of glucose concentration remained independently associated with RBC, WBC, neutrophils and monocytes in both sample matrices. No significant association was found with platelet number and erythrocyte or platelet volume. Glucose concentration decrease in uncentrifuged lithium-heparin and serum tubes depends on the baseline number of RBC, WBC, neutrophils and monocytes within the tubes.

High-intensity physical exercise increases serum α-klotho levels in healthy volunteers.

The recently discovered klotho proteins have roles in a diverse range of metabolic processes with the oldest protein, α-klotho, implicated in various cellular pathways in energy, glucose, and phosphate metabolism. Circulating soluble klotho (sKl), derived from membrane α-klotho cleavage, not only has effects on ion channels and insulin signaling pathways, but is inversely associated with mortality. Effects of physical exercise on sKl have not been well studied. The effect of a single high-intensity standardized exercise on sKl and serum phosphate (sPi) levels in healthy adults was investigated. A standard Bruce protocol treadmill exercise was undertaken by 10 fasting healthy volunteers. sKl, sPi, and blood glucose levels were measured in samples collected 1-week prior, immediately pre (T pre), 0 (T post), 30 (T 30), 240 (T 240) min, and 1-week after exercise. Median (interquartile range) age of participants was 47.5 (44–51) years; five (50%) were male. All study participants achieved at least 90% predicted maximum heart rate (MHR). sKl increased acutely after exercise (T pre median 448 pg/mL vs. T post median 576 pg/mL; p < 0.01). There was a nonsignificant sPi decline at T 30 (T pre 0.94 ± 0.12 mmol/L vs. T 30 0.83 ± 0.22 mmol/L). Exercise led to a reduction in blood glucose by T 240 with median glucose levels at T pre, T post, T 30, and T 240 of 6.0, 6.5, 6.3, and 5.7 mmol/L, respectively. In conclusion, a single high-intensity exercise session is associated with a transient increase in sKl, a delayed reduction in blood glucose, and a nonsignificant decrease in sPi levels in healthy adults. The evaluation of long-term effects of cardiovascular fitness programs on sKl and sPi in healthy individuals and disease cohorts are required to identify potential lifestyle modifications to help improve chronic disease management and long-term outcomes.

Comparative Bioavailability Study of Two 81 mg Coated Tablet Formulations of Acetylsalicylic Acid in Fasting Healthy Volunteers

Introduction: Low-dose acetylsalicylic acid is used as antithrombotic agent and the enteric-coated formulations are widely used to minimize the gastrointestinal side effects. Aim: To compare the bioavailability of two acetylsalicylic acid formulations (Ecasil-81®, 81 mg coated tablet) in fasting healthy volunteers. Methods: Healthy volunteers (n=16) were recruited to a monocentric, open label, randomized, two-way crossover pharmacokinetic study, with seven days washout period between the treatments. They received a single 81 mg oral dose of a test (new formulation) or a standard reference formulation of acetylsalicylic acid (Ecasil-81®) after about 8 h fasting. Blood samples were collected over a period of 36 h. The salicylic acid plasma concentration was evaluated by high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). Noncompartmental pharmacokinetic analysis was performed using the WinNonlin program. Results: The maximum plasma concentration (Cmax) of salicylic acid was 5433 and 5719 ng/mL reached in 3.66 and 4.02 h (tmax) for the test and the reference formulation, respectively. The 90% confidence interval of the ratios of geometric means of Cmax and area under curve of plasma concentration until the last concentration observed (AUC0- last) were within the interval 80-125%. Conclusion: The new acetylsalicylic acid formulation has a bioavailability equivalent to the reference formulation for the rate and the extent of absorption.

Moringa Oleifera leaf extract increases plasma antioxidant status associated with reduced plasma malondialdehyde concentration without hypoglycemia in fasting healthy volunteers.

To investigate the effect of Moringa Oleifera leaf extract (MOLE) on plasma glucose concentration and antioxidant status in healthy volunteers. A randomized crossover design was used in this study. Healthy volunteers were randomly assigned to receive either 200 mL of warm water (10 cases) or 200 mL of MOLE (500 mg dried extract, 10 cases). Blood samples were drawn at 0, 30, 60, 90, and 120 min for measuring fasting plasma glucose (FPG), ferric reducing ability of plasma (FRAP), Trolox equivalent antioxidant capacity (TEAC) and malondialdehyde (MDA). FPG concentration was not signifificantly different between warm water and MOLE. The consumption of MOLE acutely improved both FRAP and TEAC, with increases after 30 min of 30 μmol/L FeSO4 equivalents and 0.18 μmol/L Trolox equivalents, respectively. The change in MDA level from baseline was signifificantly lowered after the ingestion of MOLE at 30, 60, and 90 min. In addition, FRAP level was negatively correlated with plasma MDA level after an intake of MOLE. MOLE increased plasma antioxidant capacity without hypoglycemia in human. The consumption of MOLE may reduce the risk factors associated with chronic degenerative diseases.

Evaluation of the diurnal intraocular pressure fluctuations and blood pressure under dehydration due to fasting

Introduction: This study aimed to investigate the diurnal intraocular pressure fluctuations under dehydration conditions and the relationship between the intraocular pressure fluctuations and blood pressure. Methods: The intraocular pressures (IOP), body weights, as well as systolic and diastolic blood pressures (SBP, DBP) of 36 fasting healthy volunteers were recorded at 8:00 a.m. and 5:00 p.m. in the Ramadan of 2014 and two weeks after it. The data were analyzed using paired Student’s t-test and Pearson correlation analysis. Results: As the results demonstrated, the mean diurnal IOP differences of IOP, SBP, DBP, and weight were 2.67±1.33 mmHg, 9.44±8.02 mmHg, 3.33±5.94 mmHg, and 0.90±0.46 kg during the fasting period, respectively. In addition, the mean diurnal IOP differences of IOP, SBP, DBP, and weight were -0.33±1.4 mmHg (P=0.001), 0.55±7.25mmHg (P=0.003), -3.33±5.94 mmHg (P=0.001), and 0.12±0.45 kg (P=0.001) during the control period, respectively. There was a moderate correlation between the diurnal IOP and SBP differences (r=0.517, P=0.028). Conclusion: Based on the findings of the current study, the total fluid volume might have a more dominant effect on IOP peaks than the sympathetic system activity. Furthermore, the SBP was found to correlate with the IOP.

The preanalytical stability of glucagon as measured by liquid chromatography tandem mass spectrometry and two commercially available immunoassays.

Background One of the main challenges in the measurement of glucagon is the premise that it is unstable in human plasma. Traditionally, protease inhibitors have been used to prevent its degradation; however, their use is controversial. Here, we investigated the optimal method of sample collection for glucagon, with measurement by liquid chromatography tandem mass spectrometry (LC-MS/MS) and two commercially available immunoassays. Methods Blood from healthy fasting volunteers (n = 10) was processed under a variety of preanalytical conditions including collection in EDTA vs. lithium heparin tubes and the addition of aprotinin and/or a dipeptidyl-peptidase IV (DPPIV) inhibitor. Additionally, the effect of freeze thaw was assessed. Plasma glucagon concentrations were measured by LC-MS/MS and two commercially available immunoassays (HTRF® sandwich immunoassay, Cisbio and Milliplex MAP Human Metabolic Hormone Panel, Merck Millipore). Results A systematic bias of Milliplex > LC-MS/MS > HTRF was noted and plasma glucagon concentrations were significantly different between methods (Milliplex vs. LC-MS/MS P < 0.01; Milliplex vs. HTRF P < 0.0001; LC-MS/MS vs. HTRF P < 0.001). The addition of aprotinin, DPPIV inhibitor or a combination of aprotinin and DPPIV inhibitor had no effect on plasma glucagon concentrations when compared to 'non-stabilized' samples or each other. Whether samples were taken in EDTA tubes or lithium heparin tubes made no difference to plasma glucagon concentrations. These findings were consistent for all three methods. Plasma glucagon concentrations were not significantly different after two freeze-thaw cycles (performed on samples in EDTA tubes containing aprotinin and DPPIV inhibitor). Conclusions This study demonstrates that glucagon is stable in both EDTA and lithium heparin tubes when stored at -80℃. Furthermore, the addition of aprotinin and DPPIV inhibitors is unnecessary.

Fluorometric Bio-Sniffer (Gas Phase Biosensor) for Breath Acetone as a Volatile Product of Lipid Metabolism

Breath analysis for healthcare and disease monitoring has become popular recently in global. There are hundreds of volatile organic compounds (VOCs) exist in human breath, and some of them can offer medical and biological information as the bloodstream. Particularly,acetone is one of the typical VOCs in exhaled breath, which is related to lipid metabolism in fasting, exercise and diabetes mellitus. The breath acetone concentrations have been previously shown to correlate strongly with blood acetone concentrations as well as with other ketones such as beta-hydroxybutyrate. Besides, there are many studies found the correlation between the breath acetone concentrations and blood glucose concentrations. Previous research indicated that the breath acetone concentration in healthy people shows the range from 200 to 900 ppb and higher concentration was found in breath of diabetic patients. Increase of the acetone concentration is usually a sign that cells cannot effectively use glucose as energy source, which often occurs in starvation, aerobic exercise, lack of insulin or resistance of insulin. Thus, acetone in exhaled breath has a potential to be a biomarker for non-invasive monitoring the progressive of diabetes. Typical quantitation of gaseous acetone usually uses gas chromatography with mass spectrometry (GC/MS) or proton transfer reaction mass spectrometry (PTR-MS). These methods are highly sensitivity but still have disadvantages in cost, measurement time and hard for continuity. Therefore, a rapid, convenient and highly selective method for acetone determination is strongly required. In this study, a highly sensitive acetone bio-sniffer (gas-phase biosensor) was developed and used to assess the acetone from exhale breath for evaluating the lipid metabolism. Nicotinamide adenine dinucleotide (NADH)-dependent secondary alcohol dehydrogenase (S-ADH) is a kind of enzyme that can reduce acetone to be isopropanol and meanwhile oxidase NADH to be NAD+ in acidic condition. It is known that NADH can be excited by UV (ultraviolet) light at central wavelength of 340 nm and release a fluorescent emission at peak of 490 nm simultaneously, while NAD+ do not have similar optical property. Thus, acetone concentration can be measured using the decreasing of NADH fluorescence intensity that is consumed by the enzymatic reaction of S-ADH. The fluorometric acetone bio-sniffer was composed of a NADH fluorescence measurement system, a flow-cell attaching on the fiber probe and an enzyme-immobilized membrane. The NADH measurement system consisted of a UV-LED as the excitation light source, band-pass filters ( λ = 340 ± 10 nm and λ = 490 ± 10 nm) for reducing noise, a photomultiplier tube (PMT) as fluorescence detector and bifurcated optical fibers for assemble. S-ADH was immobilized on the hydrophilic-PTFE membrane and equipped on the top of flow-cell by silicone O-ring. Phosphate buffer, which contained NADH, was circulated in the flow-cell to supply fresh co-enzyme and eliminate isopropanol and NAD+that produced by the enzyme membrane. When bio-sniffer contacted the gaseous acetone, enzymatic reaction that mentioned above occurred immediately and the change of fluorescence would detect by the PMT. This acetone bio-sniffer showed rapid reaction, highly sensitivity and selectivity. When the acetone vapors were supplied to the sensing region, fluorescent intensity decreased immediately and reached to a steady state. Then, the intensity would return to the initial value in short time when the acetone vapor supply was stopped. The relation between the concentration of acetone and the change of fluorescent intensity was investigated and the dynamic range was confirmed from 20 to 5300 ppb of acetone in the gas phase. This range encompasses the concentration of acetone vapors found in breath of healthy people and of those suffering from disorders of carbohydrate metabolism. The selectivity of the S-ADH was also characterized; several different VOCs were employed to compare the responses. The interference of 2-butanol and 2-pentanone were ignorable because they contained in healthy people in very low concentration. Finally, we applied the bio-sniffer to measure breath acetone for evaluation of lipid metabolism during long time fasting and an aerobic exercise test. The results showed that the mean breath acetone concentration of long time fasting healthy volunteers were higher than those who did not have fasting and display significant difference. Furthermore, the concentration of acetone in breath was observed significantly increase during aerobic exercise and it would recover to the initial value after long time rest. This highly sensitivity acetone bio-sniffer provides a new kind of analytical tool for non-invasive evaluation of human lipid metabolism and it is also expected to use for the clinical applications such as monitoring the progression of diabetes mellitus and diagnosis of other metabolism diseases.

Use of Metabolomics to Trend Recovery and Therapy After Injury in Critically Ill Trauma Patients.

Metabolomics is the broad and parallel study of metabolites within an organism and provides a contemporaneous snapshot of physiologic state. Use of metabolomics in the clinical setting may help achieve precision medicine for those who have experienced trauma, where diagnosis and treatment are tailored to the individual patient. To examine whether metabolomics can (1) distinguish healthy volunteers from trauma patients and (2) quantify changes in catabolic metabolites over time after injury. Prospective cohort study with enrollment from September 2014 to May 2015 at an urban, level 1 trauma center. Included in the study were 10 patients with severe blunt trauma admitted within 12 hours of injury with systolic blood pressure less than 90 mm Hg or base deficit greater than 6 mEq/L and 5 healthy volunteers. Plasma samples (n = 35) were obtained on days 1, 3, and 7, and they were analyzed using mass spectrometry. Principal component analyses, multiple linear regression, and paired t tests were used to select biomarkers of interest. A broad-based metabolite profile comparison between trauma patients and healthy volunteers was performed. Specific biomarkers of interest were oxidative catabolites. Trauma patients had a median age of 45 years and a median injury severity score of 43 (interquartile range, 34-50). Healthy fasting volunteers had a median age of 33 years. Compared with healthy volunteers, trauma patients showed oxidative stress on day 1: niacinamide concentrations were a mean (interquartile range) of 0.95 (0.30-1.45) relative units for trauma patients vs 1.06 (0.96-1.09) relative units for healthy volunteers (P = .02), biotin concentrations, 0.43 (0.27-0.58) relative units for trauma patients vs 1.21 (0.93-1.56) relative units for healthy volunteers (P = .049); and choline concentrations, 0.17 (0.09-0.22) relative units for trauma patients vs 0.21 (0.18-0.22) relative units for healthy volunteers (P = .004). Trauma patients showed lower nucleotide synthesis on day 1: adenylosuccinate concentrations were 0.08 (0.04-0.12) relative units for trauma patients vs 0.15 (0.14-0.17) relative units for healthy volunteers (P = .02) and cytidine concentrations were 1.44 (0.95-1.73) relative units for trauma patients vs 1.74 (1.62-1.98) relative units for healthy volunteers (P = .05). From trauma day 1 to day 7, trauma patients showed increasing muscle catabolism: serine levels increased from 42.03 (31.20-54.95) µM to 79.37 (50.29-106.37) µM (P = .002), leucine levels increased from 69.21 (48.36-99.89) µM to 114.16 (92.89-143.52) µM (P = .004), isoleucine levels increased from 20.43 (10.92-27.41) µM to 48.72 (36.28-64.84) µM (P < .001), and valine levels increased from 122.56 (95.63-140.61) µM to 190.52 (136.68-226.07) µM (P = .004). There was an incomplete reversal of oxidative stress. Metabolomics can function as a serial, comprehensive, and potentially personalized tool to characterize metabolism after injury. A targeted metabolomics approach was associated with ongoing oxidative stress, impaired nucleotide synthesis, and initial suppression of protein metabolism followed by increased nitrogen turnover. This technique may provide new therapeutic and nutrition targets in critically injured patients.

Serum ghrelin and PYY enterohormones during acute critical illness: A prospective observational trial

Introduction Gastrointestinal failure during critical illness is associated with decreased intake and limited tolerance to enteral feeding. Enterohormones like ghrelin and PYY could play a role in these dysfunctions. This study aimed at defining: – the time course of serum ghrelin and PYY during the first 5 days of stay; – correlations with limited tolerance to enteral feeding. Material and methods Thirty consecutive patients (age: 56.4 ± 16.4; BMI: 26.3 ± 4.5) and 10 fasting healthy volunteers (age: 34.1 ± 6.8; BMI: 23.1 ± 4.2) were included. In patients, blood was sampled for 5 consecutive days and once in the control group. Blood samples were immediately centrifuged at 3000 × g for 10 minutes at 4 °C. Ghrelin samples were acidified to pH 4 and then all samples were stored at –80 °C until processing. Ghrelin and PYY serum concentrations were measured using a commercial ELISA test. Enteral feeding intolerant patients were defined as patients with at least one episode of high gastric residual volume (> 250 mL) and/or diarrhea (> 200 mL of liquid stools/day). Comparisons between continuous variables were done using ANOVA and the Wilcoxon U -test as appropriated. Alpha error was set at 5%. Results The incidence of intolerance among patients was 41.4%. Mean gastric residual volume (millilitres) was higher in intolerant than in tolerant patients ( P P = 0.03) and than controls (53.5 pg/mL [17.5–191.7 pg/mL] vs. 6.4 pg/mL [0.35–18.1 pg/mL]; P = 0.02). Daily PYY serum concentration was higher in intolerant than in tolerant patients, specifically on days 2 (median (IQR): 103.2 pg/mL [23.2–193.6 pg/mL] vs. 16.9 pg/mL [3.9–54 pg/mL]; P = 0.02) and day 5 (103.2 pg/mL [23.2–193.6 pg/mL] vs. 16.9 pg/mL [3.9 to 54 pg/mL]; P = 0.02). Controls had a significantly higher serum ghrelin concentration than either tolerant patients (median (IQR): 1435.7 pg/mL [1335.5–1775.5 pg/mL] vs. 219.4 pg/mL [84–420.5 pg/mL]; P P = 0.004). Unexpectedly, serum ghrelin concentration was higher in intolerant compared to tolerant patients (median (IQR): 283.5 pg/mL [92–1002.5 pg/mL] vs. 219.4 pg/mL [84–420.5 pg/mL]; P = 0.02). No difference in serum ghrelin concentration between tolerant compared to intolerant patients was found from day 1 to day 5. Conclusions In critically ill patients, mean serum concentration of ghrelin and PYY significantly differ from that of healthy controls. These findings support a role of enterohormones in the critical illness-associated gastrointestinal failure.

Study of FibroTest and hyaluronic acid biological variation in healthy volunteers and comparison of serum hyaluronic acid biological variation between chronic liver diseases of different etiology and fibrotic stage using confidence intervals

ObjectivesPersonalized ranges of liver fibrosis serum biomarkers such as FibroTest or hyaluronic acid could be used for early detection of fibrotic changes in patients with progressive chronic liver disease. Our aim was to generate reliable biological variation estimates for these two biomarkers with confidence intervals for within-subject biological variation and reference change value. Design and methodsNine fasting healthy volunteers and 66 chronic liver disease patients were included. Biological variation estimates were calculated for FibroTest in healthy volunteers, and for hyaluronic acid in healthy volunteers and chronic liver disease patients stratified by etiology and liver fibrosis stage. ResultsIn healthy volunteers, within-subject biological coefficient of variation (with 95% confidence intervals) and index of individuality were 20% (16%–28%) and 0.6 for FibroTest and 34% (27%–47%) and 0.79 for hyaluronic acid, respectively. Overall hyaluronic acid within-subject biological coefficient of variation was similar among non-alcoholic fatty liver disease and chronic hepatitis C with 41% (34%–52%) and 45% (39%–55%), respectively, in contrast to chronic hepatitis B with 170% (140%–215%). Hyaluronic acid within-subject biological coefficients of variation were similar between F0–F1, F2 and F3 liver fibrosis stages in non-alcoholic fatty liver disease with 34% (25%–49%), 41% (31%–59%) and 34% (23%–62%), respectively, and in chronic hepatitis C with 34% (27%–47%), 33% (26%–45%) and 38% (27%–65%), respectively. However, corresponding hyaluronic acid indexes of individuality were lower in the higher fibrosis stages. ConclusionNon-overlapping confidence intervals of biological variation estimates allowed us to detect significant differences regarding hyaluronic acid biological variation between chronic liver disease subgroups.

Motilin-induced gastric contractions signal hunger in man

RationaleHunger is controlled by the brain, which receives input from signals of the GI tract (GIT). During fasting, GIT displays a cyclical motor pattern, the migrating motor complex (MMC), regulated...

Diurnal Alterations of Refraction, Anterior Segment Biometrics, and Intraocular Pressure in Long-Time Dehydration due to Religious Fasting

Purpose: To investigate the effects of dehydration due to fasting on diurnal changes of intraocular pressure, anterior segment biometrics, and refraction. Subjects and methods: The intraocular pressures, anterior segment biometrics (axial length: AL; Central corneal thickness: CCT; Lens thickness: LT; Anterior chamber depth: ACD), and refractive measurements of 30 eyes of 15 fasting healthy male volunteers were recorded at 8:00 in the morning and 17:00 in the evening in the Ramadan of 2013 and two months later. The results were compared and the statistical analyses were performed using the Rstudio software version 0.98.501. The variables were investigated using visual (histograms, probability plots) and analytical methods (Kolmogorov-Smirnov/Shapiro-Wilk test) to determine whether or not they were normally distributed. Results: The refractive values remained stable in the fasting as well as in the control period (p = 0.384). The axial length measured slightly shorter in the fasting period (p = 0.001). The corneal thickness presented a diurnal variation, in which the cornea measured thinner in the evening. The difference between the fasting and control period was not statistically significant (p = 0.359). The major differences were observed in the anterior chamber depth and IOP. The ACD was shallower in the evening during the fasting period, where it was deeper in the control period. The diurnal IOP difference was greater in the fasting period than the control period. Both were statistically significant (p = 0.001). The LT remained unchanged in both periods. Conclusions: The major difference was shown in the anterior chamber shallowing in the evening hours and IOP. Our study contributes the hypothesis that the posterior segment of the eye is more responsible for the axial length alterations and normovolemia has a more dominant influence on diurnal IOP changes.

Bioequivalence study of a novel orodispersible tablet of meloxicam in a porous matrix after single-dose administration in healthy volunteers

Meloxicam is a non-steroidal anti-inflammatory drug, indicated for osteoarthritis exacerbations, rheumatoid arthritis and ankylosing spondylitis symptomatic treatment. To compare the bioavailability of a 15 mg meloxicam orodispersible tablet (ODT) and a reference 15 mg tablet in healthy volunteers. Two randomized, crossover, bioequivalence studies were conducted. In both studies, 28 volunteers were randomly assigned to receive test ODT and reference tablet formulations in single dose under fasting conditions in two study periods, with a 7-day (Study I) or 14-day (Study II) wash-out between administrations. Blood samples were collected at pre-specified times. Pharmacokinetic parameters were obtained by noncompartmental analysis. Bioequivalence was assumed if the 90% confidence interval of the test/reference ratio of the least-squares means for Cmax, AUC0-t and AUC0-∞were within the 80.00 -125.00% range, according to the current guidelines. All 28 subjects in Study I and 26 subjects in study II completed the study and were included in the analysis. The 90% confidence intervals of the geometric means ratios for the logtransformed Cmax, AUC0-t and AUC0-∞were 87 - 96%, 88 - 96% and 87 - 96% in Study I, and 99 - 105%, 98 - 104% and 108 - 120% in Study II. Test product was characterized by a slightly earlier tmax than the reference, i.e., 4.9 ± 1.1 vs. 5.8 ± 2.6 hours in Study I (p = 1.000) and 3.8 ± 2.0 vs. 4.8 ±1.6 hours in Study II (p = 0.0054). The two drugs were well tolerated. Test and reference formulations met the regulatory criteria for bioequivalence in the fasting healthy volunteers enrolled.