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PubMed1996

A new monitor with a zinc-oxide thin film semiconductor sensor for the measurement of volatile sulfur compounds in mouth air.

Halitosis, defined as unpleasant oral odor, is a concern among the general public. Halitosis is generally diagnosed by organoleptic examination and by gas chromatographic analysis of the main source of halitosis, volatile sulfur compounds, such as hydrogen sulfide, methyl mercaptan, and dimethyl sulfide. Gas chromatography requires a large-scale system and a long running time. We investigated the use of a zinc-oxide thin film semiconductor sensor for measuring trace volatile sulfur compounds in mouth air. Mouth air samples collected in teflon bags from 21 volunteers were analyzed by 3 methods: the monitor analysis, gas chromatography, and organoleptic examination by 3 judges. The readings of the monitor were correlated with the values of the total volatile sulfur compounds measured by gas chromatography (r = 0.75, P < 0.01) and also with the organoleptic scores given by the judges (r = 0.76, P < 0.01). The organoleptic scores were correlated with the gas chromatographic values (r = 0.71, P < 0.01). These results suggest that this new monitor with a zinc-oxide thin film semiconductor sensor may be used for the diagnosis of halitosis. Its small size and simplicity of handling may enable its use for routine chair-side study and field surveys of halitosis.

Breath Tests↗
PubMed1998

The influence of tertiary butyl alcohol and volatile salts on the sublimation of ice from frozen sucrose solutions: implications for freeze-drying.

The purpose of this work was to investigate the phase behavior of tertiary butanol (TBA) and volatile ammonium salts in frozen mixtures with some commonly used excipients and the efficacy of such volatile additives in accelerating the sublimation of ice from frozen solutions. Differential scanning calorimetry was employed to determine first-order phase transformations and glass transition temperatures in binary and ternary mixtures. Ice sublimation rates were studied by conventional freeze-drying and mass loss with time. A eutectic temperature (268 K) was identified for the anhydrous TBA-sucrose system. In frozen ternary water-excipient-TBA systems, the relative amplitudes of the glass and phase transitions, as measured during warming scans, were found to depend critically on the previous cooling rates. Glass transitions of all the freeze-concentrated mixtures used were determined. The sublimation studies indicated an ability of all volatile additives to accelerate ice sublimation from amorphous, freeze-concentrated solutions, but no clear ranking order, applicable to all systems studied, could be established.

Calorimetry, Differential Scanning↗
PubMed2007

Effects of high pressure treatment on volatile profile during ripening of ewe milk cheese.

The effect of high-pressure treatment on the volatile profile of ewe milk cheeses was investigated. Cheeses were submitted to 200, 300, 400 and 500 MPa at 2 stages of ripening (after 1 and 15 d of manufacturing) and volatile compounds were assayed at 15 and 60 d of ripening. High-pressure treatment altered the balance of volatile profile of cheeses, limiting the formation of acids, alcohols, ketones, aldehydes, and sulfur compounds and enhancing the formation of 2,3-butanedione. In general, cheeses pressurized at 15 d of ripening were more similar to untreated cheeses than those treated at 1 d. Cheeses treated at 300 MPa after 1 d of manufacturing were characterized by higher levels of free amino acids, ethanol, ethyl esters, and branched-chain aldehydes, whereas cheeses treated at 500 MPa after 1 d of manufacturing had lower microbial populations, showed the highest abundance of 2,3-butanedione, pyruvaldehyde, and methyl ketones, and the lowest abundance of alcohols.

Animals↗
PubMed1986

Effects of broiler litter volatiles and ammonia on fungal spore germination.

The effects of broiler litter volatiles on spore germination of 12 fungal species were determined. The volatiles inhibited spore germination of all species except Scopulariopsis brevicaulis. The inhibitory effect was fungistatic. The inhibitory volatile substances in litter were higher in built-up litter than in freshly used litter and were soluble in an acid solution. Ammonia was identified by infrared analysis as a fungal inhibitory substance in litter. The effect of various concentrations of ammonia produced from ammonium chloride (NH4Cl) was studied, and it was determined that concentrations of ammonia below 150 micrograms/g dry weight of litter were fungistatic for most species. At higher concentrations, ammonia was fungitoxic, with the exception of S. brevicaulis whose spore germination was not inhibited at this high concentration. Fungitoxic levels of ammonia were not found in the litter samples, but broiler house conditions necessary to produce fungitoxic levels are discussed.

Ammonia↗
PubMed1999

The immune system and the effects of non-volatile anesthetics on neutrophil transmigration through endothelial cell monolayers.

Inflammation represents the consequence of capillary dilation with accumulation of fluid and transmigration of leukocytes into the surrounding tissue. Leukocytes play a major role in the defense system of the body against invading microorganisms. This defense system has a non-specific branch consisting of granulocytes and macrophages and a specific branch of lymphocytes. Granulocytes release cytotoxic compounds from their intracellular granules into their local environment when encountering microorganisms. This random destruction happens rapidly, but it may also harm healthy tissue of the body. Leukocytes patrol the body by circulating through the blood and lymphatic system ensuring a continuous surveillance which is a prerequisite for an efficient defense. Upon tissue damage and inflammation, leukocytes are recruited from the blood to sites of injury, and this trafficking displays exquisite specificity. In the late 1890 s, Metchnikoff noted the power of certain blood cells to move towards microorganisms and ingest them. In fact, leukocytes adhere to the endothelium of the blood vessels, and subsequently leave the circulation by transmigration through the intercellular junctions of the endothelial cell monolayer. Transmigration is driven by chemoattractants, a process known as diapedesis. Reversible adherence of leukocytes to the endothelium, basement membranes, and other surfaces is an essential event in the establishment of inflammation, whose molecular basis is beginning to be understood. Inflammation may become chronic in many pathophysiologic processes and disease states. In long-term mechanically ventilated critically ill patients, non-volatile anesthetics are needed over a prolonged time period. Perioperative infections are a major cause of morbidity and mortality in critically ill patients. Therefore, the influence of non-volatile anesthetics and opioid agents on the immune system is of high interest. After presentation of the different effectors of the immune system and their fluxes through the body, the aim of this review is to propose a general model of leukocyte transmigration through endothelial cell monolayers. It emphasizes in which way different non-volatile anesthetic drugs may affect the non-specific branch of the immune system, i.e. the leukocyte transmigration through endothelial cell monolayers.

Anesthetics↗
PubMedDate not supplied

The effects of volatile anesthetic agents on pulmonary surfactant function.

The purpose of this article is to review the findings from research directed at understanding the effects of volatile anesthetics on the respiratory surface known as pulmonary surfactant. Anesthetics have long been known to have a disruptive effect on biological membranes. This review will highlight the interactions of volatile anesthetics with pulmonary surfactant. This paper has emphasized the interaction of volatile anesthetics with the pulmonary surfactant monolayer versus the lipid bilayer. The goal of this review is to uncover to what extent this understanding has progressed in forty years. Although the goal is quite broad, the information gathered and the advice given is specific. Theories of anesthesia and surfactant structure and function are summarized and discussed in light of early physico-chemical approaches and extend to an era where powerful new three-dimensional structural techniques can be used to answer this question.

Anesthetics, Inhalation↗
PubMed2001

Analysis of volatile disease markers in blood.

BACKGROUND: The diagnostic potential of breath analysis has been limited by a lack of knowledge on origin, distribution, and metabolism of the exhaled substances. To overcome this problem, we developed a method to assess trace amounts of hydrocarbons (pentane and isoprene), ketones (acetone), halogenated compounds (isoflurane), and thioethers (dimethyl sulfide) in the blood of humans and animals. METHODS: Arterial and venous blood samples were taken from mechanically ventilated patients. Additional blood samples were taken from selected vascular compartments of 19 mechanically ventilated pigs. Volatile substances were concentrated by means of solid-phase microextraction (SPME), separated by gas chromatography, and identified by mass spectrometry. RESULTS: Detection limits were 0.02-0.10 nmol/L. Venous concentrations in pigs were 0.2-1.3 nmol/L for isoprene, 0-0.3 nmol/L for pentane, and 1.2-15.1 nmol/L for dimethyl sulfide. In pigs, substances were not equally distributed among vascular compartments. In humans, median arteriovenous concentration differences were 3.58 nmol/L for isoprene and 1.56 nmol/L for pentane. These values were comparable to pulmonary excretion rates reported in the literature. Acute respiratory distress syndrome (ARDS) patients had lower isoprene concentration differences than patients without ARDS. CONCLUSIONS: The SPME method can detect volatile substances in very low concentrations in the blood of humans and animals. Analysis of volatile substances in vascular compartments will enlarge the diagnostic potential of breath analysis.

Acetone↗
PubMed2004

[Volatile anesthetics and synaptic transmission in the central nervous system].

Long-lasting changes in the synaptic efficacy of signaling between neurons in the central nervous system are thought to be involved in memory consolidation and recall. Such long-lasting changes were first demonstrated by Bliss et al. in 1973. They found that high frequency stimulation to the hippocampus produced an increase in the amplitude of excitatory postsynaptic potentials, which lasted at least for hours. This phenomenon is known as long-term potentiation (LTP). LTP occurs in many synaptic pathways, and some forms of LTP appear to be triggered by the influx of calcium through NMDA receptors. General anesthetics are thought to affect LTP, since clinically relevant concentrations of volatile anesthetics seem to modify ligand-gated ion channels such as glutamate receptors and GABA(A) receptors. Previous studies have shown that volatile anesthetics such as isoflurane and sevoflurane enhance GABA(A) receptor-mediated inhibition, suggesting that general anesthesia is produced, at least in part, by enhancing neural inhibition mediated by GABA(A) receptors. This review focuses on recent research concerning the effects of volatile anesthetics on synaptic transmission, synaptic plasticity, and clinically important diseases imparing synaptic transmission in the central nervous system.

Anesthetics, Inhalation↗
PubMed1992

[Poisoning with volatile hydrocarbons. 3 cases and a review].

BACKGROUND: Volatile crude oil derivates (hydrocarbons) are becoming more and more widely used in homes and during leisure activities. This leads to a high rate of intoxications with these products in children (5% of all pediatric intoxications, 25% of all lethal intoxications). Clinical courses, pathophysiology, and therapy of these intoxications are referred and studied. METHODS: Based on a literature review and 3 cases reports with different clinical courses, intoxications with volatile hydrocarbons are analyzed. RESULTS: The inhalation of volatile hydrocarbons causes an ARDS. This explains the high mortality. Early oxygen-treatment with PEEP-ventilation, however, facilitates a favourable outcome without residual defects as we demonstrate in one case. Another patient needs prolonged ventilatory support after a delayed start of therapy. A third patient cannot be saved even with ECMO. CONCLUSIONS: Initial pulmonary symptoms after hydrocarbon intoxication, such as coughing and cyanosis, are signs for a severe course. Immediate hospitalization with repetitive chest x-rays and adequate instant therapy are the only option to reduce the high mortality of this intoxication.

Child↗
PubMed2006

Pollution of ambient air by volatile anesthetics: a comparison of 4 anesthetic management techniques.

Long-term exposure to waste anesthetic gas (WAG) may lead to health problems. The purpose of this study was to compare WAG concentrations resulting from 4 combinations of fresh gas flow (FGF) and vaporizer settings during a simulated intravenous induction in which the anesthetic is deepened using a volatile anesthetic delivered via mask ventilation before intubation. By using a lung model, WAG was sampled 3 times each using 4 combinations and 3 volatile anesthetics: 3% sevoflurane, 2% isoflurane, and 6% desflurane. The combinations were FGF off/vaporizer on, FGF on/vaporizer off, both on, and both off. WAG was measured using a MIRAN Ambient Air Analyzer placed at a level approximating the anesthetist's head. One-way analysis of variance with a Student-Newman-Keuls post hoc test was used to compare the concentration of WAG among the combinations of FGF/vaporizer settings for each agent. Regardless of the agent, only the FGF on/vaporizer on combination at 60 seconds resulted in a statistically greater WAG level (P < .005). The results support using 3 of the 4 combinations examined when mask ventilation with a volatile agent accompanies intravenous induction. Future studies should examine other methods of controlling WAG levels and use time-weighted averages to help address clinical significance.

Adult↗
PubMed1991

Gas chromatographic method for trapping and detection of volatile organic compounds from human mouth air.

The present investigation describes a convenient method for collection and analysis of volatile organic compounds from 25 ml mouth air samples. Tenax-GC trapping devices coated with Teflon are used to adsorb and concentrate volatile organic compounds in mouth air at -20 degrees C, which are then thermally desorbed at 140 degrees C. Gas chromatography (GC) analyses are performed using an aluminum column coated with Teflon and packed with 2% poly-MPE on 80/100 mesh Tenax-GC, and employing a flame ionization detector. This procedure allows for amplification of peak heights and detection of compounds that may otherwise escape direct analysis. Of the six prominent peaks detected, identification based on retention times indicates the presence of methanol, acetaldehyde, ethanol and acetone. Volatiles collected using this procedure can be maintained at -20 degrees C for up to 48 hours before analysis. The compact sample tubes allow the system to be easily portable, particularly suitable for sampling breath of persons with localized oral or systemic diseases at locations away from the laboratory. The superiority of this method is that relatively small samples are required for analysis, unlike previously published methods which are based on collection of large volumes of expired air in plastic bags.

Air Pollutants↗
PubMedDate not supplied

Chemical analysis of smoke of Indian cigarettes, bidis and other indigenous forms of smoking--levels of steam-volatile phenol, hydrogen cyanide and benzo(a)pyrene.

Levels of steam-volatile phenol, hydrogen cyanide and benzo(a)pyrene in various types of tobacco smoking products marketed in the country have been determined for the first time. Steam-volatile phenol levels in six popular brands of Indian cigarettes varied from 118 to 226 micrograms, and in six popular brands of bidis, from 129 to 273 micrograms. Cheroot and cigarillos yielded 400 micrograms and 333 micrograms steam-volatile phenol respectively. The hydrogen cyanide levels in the mainstream smoke of five popular brands of Indian cigarettes varied from 366 to 638 micrograms and in the mainstream smoke of four popular brands of bidis from 688 to 904 micrograms. Cheroot and cigarillos yielded 588 micrograms and 1119 micrograms hydrogen cyanide respectively. The values of benzo(a)pyrene content in Indian cigarettes varied from 85 to 114 ng and in bidis from 108 to 144 ng. Herbal bidi and cheroot had 1315 ng and 2519 ng benzo(a)pyrene respectively. Cigarettes were smoked as per international standard smoking conditions and the levels of noxious agent were found to be higher than in currently marketed western cigarettes. However, these levels in all the indigenous products including bidis cannot be directly compared with those of cigarettes as they were smoked under modified conditions.

Benzo(a)pyrene↗
PubMedDate not supplied

[Effect of long-term anti-orthostatic hypokinesia on the composition of volatile metabolites in the exhaled air].

This paper presents measurements of volatile metabolites in the air exhaled by test subjects exposed to year-long antiorthostatic hypokinesia (-5 degrees). The test subjects were subdivided into two groups (Group A and Group B), which used different countermeasures. It was found that during the first 30 days of exposure exhalation of volatile metabolites reached a new and higher level. During test days 1 through 240 the content of volatile metabolites increased significantly in both groups; however the increase in Group B was less expressed than in Group A. At the final stage of the experiment, i.e. from day 240 through 370, the difference between the two groups was levelled off.

Acetaldehyde↗
PubMed1989

[Response of the cervical sympathetic activity to acute hypoxemia in dogs and its modification by volatile anesthetics].

Response of the cervical sympathetic activity (CSA) to acute hypoxemia was studied in dogs in the absence and in the presence of either halothane (H), enflurane (E), isoflurane (I) or sevoflurane (S). Multifiber potentials of CSA, EEG, heart rate (HR), arterial blood pressure (ABP) and arterial oxygen saturation (SaO2) were continuously monitored. CSA increased responding to acutely induced hypoxemia at a speed of -6 - 9% (SaO2).min-1. The response of CSA was estimated in two ways as a function of SaO2: The threshold was determined at the SaO2 level where CSA increased by 3% over the basal level and the gain was determined by the slope of CSA increase divided by the SaO2 span. They were 92% and -1.88 in the absence of volatile anesthetics, respectively. The threshold and the gain decreased markedly in the presence of various concentrations of volatile anesthetics. They were 89.2% and -1.16; 81% and -0.74; 84.2% and -1.16 and 86.2% and -0.94 with 1 MAC of H, E, I and S, respectively. The depressant effects of volatile anesthetics on the CSA responses to acutely induced hypoxemia can cause depressed control of the autonomic nervous system against hypoxemia and conceal the manifestation of clinical signs of hypoxemia.

Anesthetics↗
PubMed1986

[Volatile anesthetics and tricyclic antidepressives. A case study].

Tricyclic antidepressants (TAD) are administered for therapy of nearly all types of depression. Interactions with anaesthetics are well known and are reported frequently in the literature. A case report about incidental findings from a series of experimental anaesthesias in healthy volunteers using different inhalation anaesthetics is presented enabling discussion of the problem of a possibly increased risk of anaesthesia in the presence of chronic TAD medication. 16 unpremedicated healthy subjects (mean age 27 +/- 4 y) received, at intervals of four weeks, inhalation anaesthesia by breathing spontaneously one of the volatile anaesthetics halothane, enflurane, or isoflurane in oxygen. The aim of the study was to investigate the influence of volatile anaesthetics on the human electroencephalogram. When evaluating the results an atypical increase of heart rate during anaesthesia was noticed in one subject. This tachycardia appeared during all three types of anaesthesia, all other observed parameters being normal. With the knowledge of these facts the volunteer was interviewed more thoroughly. He then admitted to have taken daily 125-175 mg of the TAD amitriptyline during the whole period of experiments (self-medication from lover's grief). We supposed therefore that the tachycardia during anaesthesia could be interpreted as an interaction between the TAD amitriptyline and the volatile anaesthetics halothane, enflurane, and isoflurane. After having discontinued TAD medication for some months, the volunteer, a medical student, repeated the experimental isoflurane anaesthesia with all other conditions identical. This time his heart rate did not differ from that of the other subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Gas chromatographic determination of electron capture sensitive volatile industrial chemical residues in foods, using AOAC pesticide multiresidue extraction and cleanup procedures.

Electron capture (EC) gas chromatographic (GC) parameters have been developed for determining some of the more volatile industrial chemicals that can be determined by the AOAC multiresidue method for organochlorine and organophosphorus pesticides with modified GC operating conditions. Retention times relative to pentachlorobenzene are reported for 143 industrial chemicals, pesticides, and related compounds on OV-101 GC columns at 130 degrees C. Also reported for most of the compounds are recoveries from fortified samples carried through the AOAC extraction and cleanup procedures for fatty and/or nonfatty foods, Florisil elution characteristics, and GC relative retention times on mixed OV-101 + OV-210 columns at 130 degrees C. Our laboratory has used the modified EC/GC parameters with the AOAC multiresidue extraction/cleanup procedures to determine many volatile halogenated industrial chemical contaminants in foods, chiefly in samples of fresh-water fish. Other modifications of the AOAC method are described to improve the tentative identification and quantitative measurement of these volatile residues.

Animals↗
PubMed1984

Volatile N-nitrosamines in baby bottle rubber nipples and pacifiers. Analysis, occurrence and migration.

A simple direct extraction method has been developed for rapid determination of volatile N-nitrosamines in rubber nipples and pacifiers. It consists of overnight extraction of the sample with dichloromethane in the presence of ascorbyl palmitate for N-nitrosation inhibition, filtration of the extract and rinsing of the samples with dichloromethane, concentration of the extract using a Kuderna-Danish concentrator, and final analysis by gas-liquid chromatography-Thermal Energy Analyser. The method gave excellent (80-100%) recoveries of various volatile N-nitrosamines that had been added to cut nipples or pacifiers at 20-80 micrograms/kg levels, and gave comparable or lower values than those obtained with another published method. The method is recommended for rapid screening purposes. A survey of 30 samples of various nipples and pacifiers indicated the presence of the following N-nitrosamines: N-nitrosodimethylamine (up to 70 micrograms/kg), N-nitrosodiethylamine (up to 88 micrograms/kg), N-nitrosodi-n-butylamine (up to 2796 micrograms/kg), N-nitrosopiperidine (up to 180 micrograms/kg), and N-nitrosomorpholine (up to 86 micrograms/kg). A more recent study, however, indicated a general decline in the levels of various volatile N-nitrosamines in these products. These N-nitrosamines were shown to migrate easily from the rubber products to liquid infant formula, orange juice and simulated human saliva.

Humans↗
PubMed1983

Profiles of urinary volatiles from metabolic disorders characterized by unusual odors.

The profiles of urinary volatiles from patients with phenylketonuria, maple syrup urine disease, isovaleric acidemia, or trimethylaminuria (fish-odor syndrome) were in each case vastly different from the normal urinary volatiles profile. In the maple syrup urine disease case, metabolites that occur distal to the block were found and a mechanism for their formation is suggested. A new major metabolite in isovaleric acidemia was also found. As well as providing a reliable diagnostic tool for diseases characterized by odors, the analysis of urinary volatiles may provide information to help our understanding of still unexplained aspects of the diseases.

Adolescent↗