Time-course of cigarette smoke contamination of clinical hydrogen breath-analysis tests.

1983 ◽  
Vol 29 (11) ◽  
pp. 1980-1981 ◽  
Author(s):  
A Rosenthal ◽  
N W Solomons
Keyword(s):  
Gas Chromatography ◽  
Cigarette Smoke ◽  
Time Course ◽  
Fold Increase ◽  
Breath Hydrogen ◽  
Breath Sample ◽  
Breath Tests ◽  
Exhaled Air ◽  
Baseline Values ◽  
Hydrogen Breath Tests

Abstract The time-course of the contamination of exogenous hydrogen from cigarette smoke on postprandial breath hydrogen concentration was evaluated in 10 subjects, six regular smokers and four occasional smokers. Breath hydrogen values were determined by gas chromatography 10 min, 5 min, and immediately prior to smoking a filter cigarette; during smoking from a sample of exhaled air containing smoke; and 5, 10, and 15 min after extinguishing the cigarette. A three- to 137-fold increase above basal hydrogen concentrations was produced by exhaled cigarette smoke, but most subjects had re-equilibrated to baseline values within 10 to 15 min after the cigarette. If subjects undergoing clinical hydrogen breath tests cannot refrain from smoking during the duration of the test, one should allow an interval of at least 15 min from the end of smoking to the collection of a breath sample.

scholarly journals The transcription factor OpWRKY2 positively regulates the biosynthesis of the anticancer drug camptothecin in Ophiorrhiza pumila

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Xiaolong Hao ◽  
Chenhong Xie ◽  
Qingyan Ruan ◽  
Xichen Zhang ◽  
Chao Wu ◽  
...  
Keyword(s):  
Transcription Factor ◽  
Anticancer Activity ◽  
Time Course ◽  
Indole Alkaloid ◽  
Fold Increase ◽  
Wrky Transcription Factor ◽  
Mobility Shift ◽  
Pathway Gene ◽  
Low Concentrations ◽  
Encoding Gene

AbstractThe limited bioavailability of plant-derived natural products with anticancer activity poses major challenges to the pharmaceutical industry. An example of this is camptothecin, a monoterpene indole alkaloid with potent anticancer activity that is extracted at very low concentrations from woody plants. Recently, camptothecin biosynthesis has been shown to become biotechnologically amenable in hairy-root systems of the natural producer Ophiorrhiza pumila. Here, time-course expression and metabolite analyses were performed to identify novel transcriptional regulators of camptothecin biosynthesis in O. pumila. It is shown here that camptothecin production increased over cultivation time and that the expression pattern of the WRKY transcription factor encoding gene OpWRKY2 is closely correlated with camptothecin accumulation. Overexpression of OpWRKY2 led to a more than three-fold increase in camptothecin levels. Accordingly, silencing of OpWRKY2 correlated with decreased camptothecin levels in the plant. Further detailed molecular characterization by electrophoretic mobility shift, yeast one-hybrid and dual-luciferase assays showed that OpWRKY2 directly binds and activates the central camptothecin pathway gene OpTDC. Taken together, the results of this study demonstrate that OpWRKY2 acts as a direct positive regulator of camptothecin biosynthesis. As such, a feasible strategy for the over-accumulation of camptothecin in a biotechnologically amenable system is presented.

scholarly journals Amplification of the thapsigargin-evoked increase in the cytosolic free Ca2+ concentration by acetylcholine in acutely isolated mouse submandibular acinar cells

1996 ◽  
Vol 317 (3) ◽  
pp. 779-783 ◽  
Author(s):  
Peter. M. SMITH ◽  
Helen. E. REED
Keyword(s):  
Plasma Membrane ◽  
Time Course ◽  
Acinar Cells ◽  
Fold Increase ◽  
Extrusion Process ◽  
Significant Alteration ◽  
Atpase Inhibitor ◽  
Fura 2

The intracellular Ca2+ concentration was measured in single, acutely isolated, mouse submandibular acinar cells loaded with fura-2 AM. All experiments were performed in the absence of extracellular Ca2+ in order to eliminate Ca2+ influx. The microsomal ATPase inhibitor, thapsigargin, was used to release Ca2+ from intracellular stores and simultaneously prevent re-uptake into the stores. Sequential application of thapsigargin (2 μM) and the Ca2+ ionophore ionomycin (500 nM) indicated that thapsigargin was able to mobilize practically all intracellular Ca2+. Furthermore, in comparison with results obtained following inhibition of the plasma membrane Ca2+-ATPase by La3+ (2 mM), it may be shown that slowly unloading the intracellular Ca2+ stores using thapsigargin does not normally cause a massive, cytotoxic, increase in the cytosolic Ca2+ concentration, because Ca2+ is rapidly extruded from the cell across the plasma membrane. Application of a submaximal dose of acetylcholine (500 nM) during the rising phase of the response to thapsigargin caused a 3–4-fold increase in the amplitude of the rise in the cytosolic Ca2+ concentration without any significant alteration of the time course of the response. As thapsigargin alone is capable of mobilizing all releasable Ca2+, this increase in amplitude is most likely the result of inhibition of the Ca2+ extrusion process by acetylcholine.

scholarly journals The Use of Cryogenic Temperature Gas Chromatography for the Determination of Carbon Monoxide and Carbon Dioxide in Cigarette Smoke

1972 ◽  
Vol 6 (4) ◽  
Author(s):  
G.P. Morie ◽  
C.H. Sloan
Keyword(s):  
Carbon Dioxide ◽  
Gas Chromatography ◽  
Carbon Monoxide ◽  
Liquid Nitrogen ◽  
Cigarette Smoke ◽  
Cryogenic Temperature ◽  
Chromatographic Method ◽  
Porapak Q ◽  
Gas Chromatographic Method

AbstractA gas chromatographic method for the determination of carbon monoxide and carbon dioxide in cigarette smoke was developed. A column containing Porapak Q packing and a cryogenic temperature programmer which employed liquid nitrogen to cool the column to subambient temperatures was used. The separation of N

scholarly journals Dynamics of humoral immune response in pregnant mares and foals vaccinated with Theileria equi recombinant EMA-2

2018 ◽  
Vol 38 (6) ◽  
pp. 1105-1109
Author(s):  
Alice C. Santos ◽  
Fábio P.L. Leite ◽  
Ana M. Vianna ◽  
Guilherme B. Weege ◽  
Ilusca S. Finger ◽  
...  
Keyword(s):  
Immune Response ◽  
Humoral Immune Response ◽  
Fold Increase ◽  
Serum Levels ◽  
Vaccination Schedule ◽  
Theileria Equi ◽  
Humoral Immune ◽  
Baseline Values ◽  
Antibody Levels ◽  
First Time

ABSTRACT: Theileria equi is an infectious hemoprotozoan agent of equine piroplasmosis, a disease that has severe economic and sanitary impact internationally. In addition to its common clinical features, piroplasmosis can cause gestational losses and neonatal damage, which makes neonates susceptible to this disease. The aim of this study was to evaluate the dynamics of humoral immune response to recombinant EMA-2 of T. equi in pregnant mares and foals, as well as the transfer of vaccine antibodies through the colostrum ingested by sucking foals. For vaccine production, the EMA-2 expression gene was cloned and expressed in the yeast species, Pichia pastoris. Thirty-six horses were used, of which 18 were pregnant mares and 18 were foals. The mares were divided into control and vaccinated groups, and the vaccinated group received three doses of rEMA-2 every 21 days starting at 300 days of gestation. Foals from vaccinated and control groups were evaluated until the sixth month of life. The production of antibodies by foals on the rEMA-2 vaccination schedule was also evaluated from the second month of life. Foals in the vaccinated group had received three doses of the vaccine every 21 days. The method used to evaluate serum and colostrum samples was indirect ELISA, and plates were sensitized with the rEMA-2 protein. At the end of the vaccination schedule, vaccinated mares showed a 2.3-fold increase in antibody levels when compared to baseline values. The colostrum of vaccinated mares presented antibody levels of 1.0432±0.33. Foals delivered by vaccinated mares presented levels of antibodies greater than those of foals delivered by control mares after their first time sucking (at about twelve hours after birth). Foals vaccinated in the second month of life showed an 8.3-fold increase in antibody levels when compared to baseline values. The vaccination schedule with rEMA-2 was able to stimulate humoral immunity in pregnant mares. Vaccine immunoglobins were concentrated in the colostrum of vaccinated mares and foals delivered by these mares showed an increase in serum levels of vaccine antibodies after the first-time sucking.

Tar and Nicotine in Cigarette Smoke

1969 ◽  
Vol 52 (3) ◽  
pp. 458-462 ◽  
Author(s):  
H C Pillsbury ◽  
C C Bright ◽  
K J O"Connor ◽  
F W Irish
Keyword(s):  
Gas Chromatography ◽  
Weight Gain ◽  
Relative Humidity ◽  
Cigarette Smoke ◽  
Confidence Level ◽  
Coefficient Of Variation ◽  
Random Order ◽  
Filter Holder ◽  
Isopropanol Solution

Abstract Cigarettes were conditioned 24 hr at 75°F and 60% relative humidity prior to being selected and smoked in a random order. Cigarettes were smoked in a Cambridge filter holder on an automatic smoking machine to a pre-determined butt length. TPM wet collection was on a CM113A filter disk and was determined as the net weight gain in the Cambridge filter holder after smoking. The filter pads were extracted with dioxane-isopropanol solution and were analyzed for moisture by gas chromatography. The pads and solvent extracts were steam distilled and the distillate was analyzed spectrophotometrically for nicotine. TPM dry was calculated as TPM wet minus nicotine and water. The coefficient of variation in this method is less than 5% with a 95% confidence level.

scholarly journals Regulation of skeletal muscle ATP catabolism by AMPD1 genotype during sprint exercise in asymptomatic subjects

2001 ◽  
Vol 91 (1) ◽  
pp. 258-264 ◽  
Author(s):  
Barbara Norman ◽  
Richard L. Sabina ◽  
Eva Jansson
Keyword(s):  
Skeletal Muscle ◽  
Energy Metabolism ◽  
Time Course ◽  
Fold Increase ◽  
Amp Deaminase ◽  
Biopsy Material ◽  
Plasma Ammonia ◽  
Muscle Energy ◽  
Muscle Energy Metabolism ◽  
Asymptomatic Subjects

Deficiency of myoadenylate deaminase, the muscle isoform of AMP deaminase encoded by the AMPD1 gene, is a common myopathic condition associated with alterations in skeletal muscle energy metabolism. However, recent studies have demonstrated that most individuals harboring this genetic abnormality are asymptomatic. Therefore, 18 healthy subjects with different AMPD1 genotypes were studied during a 30-s Wingate test in order to evaluate the influence of this inherited defect in AMPD1 expression on skeletal muscle energy metabolism and exercise performance in the asymptomatic population. Exercise performances were similar across the AMPD1 genotypes, whereas significant differences in several descriptors of energy metabolism were observed. Normal homozygotes (NN) exhibited the highest levels of AMP deaminase activities, net ATP catabolism, and IMP accumulation, whereas intermediate values were observed in heterozygotes (MN). Conversely, mutant homozygotes (MM) had very low AMP deaminase activities and showed no significant net catabolism of ATP or IMP accumulation. Accordingly, MM also did not show any postexercise increase in plasma ammonia. Unexpectedly, MN consistently exhibited greater increases in plasma ammonia compared with NN despite the relatively lower accumulation of IMP in skeletal muscle. Moreover, time course profiles of postexercise plasma ammonia and blood lactate accumulation also differed across AMPD1 genotypes. Finally, analysis of adenosine in leftover biopsy material revealed a modest twofold increase in MN and a dramatic 25-fold increase in MM.

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