PubMed Health⌕ Search

Biomedical subjects

N T Lequang

Publications and source records attributed to N T Lequang.

6 recordsLinked to original sources
PubMed1997

Usefulness of markers in managing tobacco withdrawal.

To evaluate the usefulness of tobacco markers in dependent smokers being treated with transdermal nicotine patches, a study was conducted at the Tobacco Withdrawal Consultation Centre at the Hôpital Laennec, Paris, France. 125 patients were included in the study and, in a first time, carbon monoxide in exhaled air, carboxyhaemoglobin, urinary nicotine and cotinine, Fagerström index, were measured and correlated to the amount of nicotine inhaled per day. The most significant value was observed for cotinine. In a second time, 25 patients were followed clinically and biologically with urinary continine monitoring (group FC) and 73 were followed up only clinically (group FC). The success rate of therapy 12 weeks after the end of treatment was 72% in group FB and 28% in group FC. The nicotine patch dose was positively correlated (p < 0.01) with successful outcome. The lower the urinary cotinine level at 4 weeks, the more likely was successful outcome (p < 0.05). If psychological factors remain important, urinary cotinine monitoring in the course of nicotine patch treatment thus favours successful withdrawal.

Administration, Cutaneous↗
PubMed1994

[Quantification of passive smoking in an survey of smoking coaches in the French high-speed trains (TGV Sud-Est)].

OBJECTIVES: Passive smoking has been demonstrated in many situations. We designed an experimental protocol to measure passive smoking in the coaches of the French high-speed train (TGV) and to attempt to identify interindividual variability in sensitivity. METHODS: Ten healthy non-smokers (5 males, 5 females) volunteered to avoid exposure to tobacco smoke for the duration of the study. On three separate occasion they were subjected to a 5-hour trip in the smoking coaches of the French TGV (south-east line). Twelve-hour urine samples were collected before each trip and over the following 72 hours. Urinary cotinine was measured in each fraction. RESULTS: Significant levels of urinary cotinine were found for a prolonged period in these passive smokers. Elimination of the tobacco by-product was similar to the level observed in subjects smoking 2 to 5 cigarettes per day. The kinetics of cotinine elimination was reproducible from one trip to another for any given individual, however significant interindividual variability was observed despite normal liver function in all. CONCLUSION: Measurement of urinary cotinine is potentially useful in non-smokers who are involuntarily exposed to tobacco smoke and who wish to know the extent of their exposure.

Adult↗
PubMed1994

Urine collection for nicotine and cotinine measurement in studies on nicotine addicts.

One of the reasons for the paucity of tabagism exposure data on the consequences of smoking is the difficulty in obtaining urine samples and the fact that the optimal storage conditions remains undetermined. The authors therefore assessed the influence of storage on urinary nicotine and cotinine levels both at room temperature and after freezing. The variations observed were not statistically significant for up to 30 hours at room temperature or for up to 8 days at -25 degrees C. They then studied the excretion of cotinine and nicotine in overnight and 24-h urine specimens collected from 90 non-smokers exposed to tobacco smoke and 40 smokers. The correlation between overnight and 24-h excretion was excellent in the case of cotinine (r = 0.89) and poor for nicotine (r = 0.18), probably because of their respective half-lives. Lastly, the usefulness of referring the urinary cotinine to the urinary creatinine was questioned. The authors conclude that valuable studies should be based on overnight urines samples stored at room temperature for up to 30 hours and then frozen at -25 degrees C until quantification of cotinine expressed in microgram/fraction.

Adult↗
PubMed1991

Concentrations of high-density lipoprotein subfraction HDL2 and lipoprotein A-I in a random population of healthy subjects.

High-density lipoproteins (HDL) are now currently subdivided according either to density and size-HDL2 and HDL3--or to surface apoprotein composition--lipoprotein A-I (LpA-I) without A-II, and LpA-I:A-II. In samples from blood bank donors (60 women, 47 men), we evaluated HDL subclasses, LpA-I particles, and other classic risk factors for atherosclerosis and compared them with each other. We found a good correlation between HDL2 and LpA-I (r = 0.74, P less than 0.001), the correlation being more marked in women (r = 0.74) than in men (r = 0.67). LpA-I was also strongly correlated with total apolipoprotein A-I (apoA-I) (r = 0.61), which suggests that LpA-I represents a significant portion of the variable pool of apoA-I. By contrast, LpA-I:A-II but not LpA-I was correlated with HDL3, confirming the preferential association of LpA-I with HDL2. The difference between the sexes was more marked for HDL2 (+66% in women) than for LpA-I (+25%). We conclude that in normolipemic subjects the size of the HDL2 pool depends on that of LpA-I. Considering the speed and low cost of the assay, determination of HDL2 cholesterol might be a useful tool for assessing cardiovascular risk.

Apolipoprotein A-I↗