Kazutoshi Nose

NEW MEASUREMENT OF HYDROGEN GAS AND ACETONE VAPOR IN GASES EMANATING FROM HUMAN SKIN

ABSTRACT We have found that hydrogen gas and acetone vapor emanate from human skin. Emanation gases from human skin were collected for 5–10 min from arm, palm, or forefinger with a homemade probe and bags. The trapped gases were analyzed by gas chromatography, and hydrogen gas and acetone vapor were found to exist in all subjects. The probe (44 mm outer diameter, 6 mm height and inner volume of 3.8 mL) directly covered a 9.4 cm2—flat skin surface of the arm, and a modified Tedlar bag or aluminum bag could cover a finger or the whole palm. The average rates of acetone vapor and hydrogen gas released from human skin (15 subjects) is 80–800 and 5–50 pg cm−2 min−1, respectively. There is a good linear relationship between the emanation rate and the concentration of those gases in human breath. Correlation factors for acetone vapor and hydrogen gas are 0.81 and 0.66, respectively. The proposed non-invasive clinical technique imposes only very minor physical stress on a subject during sampling.

Estimation of Molecular Hydrogen Consumption in the Human Whole Body After the Ingestion of Hydrogen-Rich Water

Recent studies have revealed that inhaled or ingested hydrogen gas (H2) inactivates reactive oxygen species such as hydroxyl radicals in various kinds of diseases and disorders in animal models and that H2 reduces oxidative stress-induced damage in brain, heart, and other peripheral tissues. These reports suggested that exogenous H2 is partially trapped by oxygen radicals. This study was conducted to evaluate H2 consumption after the ingestion of H2-rich water. Seven adult subjects ingested H2-rich water. The H2 content of their expired breath was measured by gas chromatography with a semiconductor. The ingestion of H2-rich water rapidly increased breath H2 content to its maximal level of approximately 36 ppm at 10 min after ingestion and thereafter decreased it to the baseline level within 60 min. Taken together with simultaneous measurements of expiratory minute volume, 59% of the ingested H2 was exhaled. The loss of H2 from the water during the experimental procedures accounted for 3% or less of the H2. H2 release from the skin surface was estimated as approximately 0.1%. Based on the remaining H2 mass balance, approximately 40% of the ingested H2 was consumed in the body. As the H2 molecule is reported to be a weak scavenger of hydroxyl radicals and is not effective against superoxide or hydrogen peroxide, the rate of hydroxyl radical production was estimated to be at least 1.0 μmol/min/m2 (equivalent to 29 nmol/min/kg), assuming that the H2 molecules were all used to scavenge hydroxyl radicals and that bacterial consumption in the alimentary tract and on the skin surface could be excluded. In summary, 59% of ingested H2 was exhaled, and most of the remainder was consumed in the body.

Breath Hydrogen Produced by Ingestion of Commercial Hydrogen Water and Milk

Objective To compare how and to what extent ingestion of hydrogen water and milk increase breath hydrogen in adults. Methods Five subjects without specific diseases, ingested distilled or hydrogen water and milk as a reference material that could increase breath hydrogen. Their end-alveolar breath hydrogen was measured. Results Ingestion of hydrogen water rapidly increased breath hydrogen to the maximal level of approximately 40 ppm 10–15 min after ingestion and thereafter rapidly decreased to the baseline level, whereas ingestion of the same amount of distilled water did not change breath hydrogen (p < 0.001). Ingestion of hydrogen water increased both hydrogen peaks and the area under the curve (AUC) of breath hydrogen in a dose-dependent manner. Ingestion of milk showed a delayed and sustained increase of breath hydrogen in subjects with milk intolerance for up to 540 min. Ingestion of hydrogen water produced breath hydrogen at AUC levels of 2 to 9 ppm hour, whereas milk increased breath hydrogen to AUC levels of 164 ppm hour for 540 min after drinking. Conclusion Hydrogen water caused a rapid increase in breath hydrogen in a dose-dependent manner; however, the rise in breath hydrogen was not sustained compared with milk.

High-throughput assay of nitric oxide metabolites in human plasma without deproteinization by lab-on-a-chip electrophoresis using a zwitterionic additive

In order to develop a high-throughput assay for nitric oxide metabolites, nitrite (NO2-) and nitrate (NO3-), in biological fluids, we have investigated the simultaneous determination of them using an electrophoretic lab-on-a-chip (microchip capillary electrophoresis, MCE) technique. In this study, in order to establish an MCE assay process without deproteinization, the addition of a zwitterionic additive into the running buffer to reduce the adsorption of protein onto the surface of channel was investigated. Initially, some zwitterionic additives were investigated by making a comparison of relative standard deviations (RSDs) of the migration times for NO2(-) and NO3(-) on capillary electrophoresis. From the results of our comparison of the RSD values, 2% (w/w) N-cyclohexyl-2-aminoethanesulfonic acid (CHES) was selected. As a result of the application of the running buffer with CHES to the MCE process, the complete separation of NO2(-) and NO3(-) in human plasma without deproteinization was achieved within 1 min. Since the RSD values of the positions of the peaks were less than 2.3%, beneficial reduction effects on MCE were suggested. When we used an internal standard method in order to correct the injection volume, the RSDs of the peak heights and areas were less than 10%, and the correlation coefficients of spiked calibration curves ranging from 0 to 350 microM were 0.999 and 0.997 for NO2(-) and NO3(-), respectively. The limits of detection (S/N=3) were 53 microM for NO2(-) and 41 microM for NO3(-). Moreover, the correlation coefficients in excess of 0.99 between the MCE method and a conventional Griess method were achieved for both NO2(-) and NO3(-). Consequently, the possibility of establishing a high-throughput assay process was obtained by utilizing 2% (w/w) CHES to reduce protein adsorption.

Analysis of Breath and Skin Gases Emanating During Exercise Using an Original Biogas Sampling System Connected to an Atmospheric Pressure Ionization Mass Spectrometer

Cardiopulmonary exercise testing is widely used in the field of sports and clinical medicine. Among the indices for evaluating exercise capacity, the anaerobic threshold is one of the most important parameters, often represented by the ventilatory threshold. The threshold, however, is sometimes not easy to determine. Yet, while more than several thousands kinds of chemical have been detected in human breath, there have been relatively few reports about the chemicals released within skin gas. In the present paper, we examined human breath and skin gas mass spectra data to explore the chemical compounds associated with anaerobic metabolism during exercise. Six healthy men, breathing purified artificial air via a two-way valve mouth piece and performing incremental bicycle ergometer exercises, were studied. Their breath was continuously analyzed using an atmospheric pressure ionization mass spectrometer (APIMS). On separate experimental days, skin gas from the palms of five subjects during the same exercise routine was monitored by an originally developed skin gas sampling system connected to the APIMS. The API mass spectra (represented by ion intensities at m /z = 3 - 200 ) indicated numerous changing patterns between subject rest, warm up, ramp exercise and recovery periods. The exercise states caused remarkable increases to ion intensity. This was to within 7 and 6 kinds of m/z for breath and skin gas respectively. During recovery, by contrast, ion intensities gradually decreased. The changing ion intensity patterns displayed some similarity to oxygen consumption patterns.

Molecular Hydrogen Consumption in the Human Body During the Inhalation of Hydrogen Gas

Inhaling or ingesting hydrogen (H2) gas improves oxidative stress-induced damage in animal models and humans. We previously reported that H2 was consumed throughout the human body after the ingestion of H2-rich water and that the H2 consumption rate ([Formula: see text]) was 1.0 μmol/min/m(2) body surface area. To confirm this result, we evaluated [Formula: see text]during the inhalation of low levels of H2 gas. After measuring the baseline levels of exhaled H2 during room air breathing via a one-way valve and a mouthpiece, the subject breathed low levels (160 ppm) of H2 gas mixed with purified artificial air. The H2 levels of their inspired and expired breath were measured by gas chromatography using a semiconductor sensor. [Formula: see text] was calculated using a ventilation equation derived from the inspired and expired concentrations of O2/CO2/H2, and the expired minute ventilation volume, which was measured with a respiromonitor. As a result, [Formula: see text] was found to be approximately 0.7 μmol/min/m(2)BSA, which was compatible with the findings we obtained using H2-rich water. [Formula: see text] varied markedly when pretreatment fasting to reduce colonic fermentation was not employed, i.e., when the subjects baseline breath hydrogen level was 10 ppm or greater. Our H2 inhalation method might be useful for the noninvasive monitoring of hydroxyl radical production in the human body.

Case study on changes in exhalation of carbon monoxide and nitrogen oxide in breath and skin gas during 2-day smoking cessation and restart

It is generally accepted that the breath of current smokers contains higher carbon monoxide (CO) and lower nitric oxide (NO) and that smoking cessation increases NO and decreases CO in breath. However, it remains unknown whether cigarette cessation reversibly changes breath NO/CO levels and how smoking cessation and restart could modify CO/NO-producing abilities in breath and skin gas. In the present case study, a so-called healthy smoker repeatedly performed 2-day smoking cessation and restart. To compare breath and skin exhalation, minute exhalation volumes per body surface of CO (VCO), NO (VNO) and nitrogen oxide (NO(x), VNO(x)) in breath and skin gas were calculated using gas chromatography with a semiconductor sensor, chemiluminescence method and respiro-monitor. We found a rapid decrease of breath VCO during smoking cessation and an increase of breath VCO after restart, insignificant changes in skin VCO, insignificant changes in breath and skin VNO, and significant biphasic and reversible changes in breath and skin VNO(x)/VNO(2) (= VNO(x) - VNO). Dominant NO(x) was NO in breath and NO(2) in skin gas. These results suggested that CO and NO(x) in breath and skin gas could be reversibly and acutely altered during 2-day smoking cessation and restart even in the case of a long-term cigarette smoker.

Emanation of Hydroxyl Radicals From Human Skin

Hydroxyl radicals (OH) that emanated from the skin on the palm of the hand were detected using a novel laser-induced fluorescence system, which consisted of an ultraviolet laser system, a chamber with a sample entrance, and a detection system with a photomultiplier. When a subject placed the palm of their hand over the sampling entrance, the resultant excitation spectrum exhibited a specific increase in the region representing the resonance fluorescence signal for OH radicals. By examining seven volunteers using the system, we found that the ingestion of a vitamin C solution significantly decreased the palm to background signal ratio from 1.16±0.04 (SD) to 1.03±0.03 and that vitamin E significantly reduced the ratio from 1.14±0.09 to 1.00±0.04. These results strongly suggest that OH radicals emanate from the skin surface.