Lymphocytic Subpopulation Profiles in Bronchoalveolar Lavage Fluid and Peripheral Blood From Tobacco and Marijuana Smokers: Subjects
Healthy adult volunteers aged 25 to 50 years were recruited by public notices and newspaper advertisements. Eligibility of potential subjects who responded was determined using a standard screening questionnaire. Entry criteria included the following: (1) white; (2) either no marijuana use in the previous 3 years or current heavy, habitual marijuana use (a history of smoking at least 10 joints per week or the equivalent for the past 5 years); (3) no history of illicit drugs injected intravenously or of illicit substances other than cannabis inhaled into the lower respiratory tract; (4) no history of potentially harmful occupational exposure; and (5) no known current cardiorespiratory illness. mycanadianpharmacy
Fifty-six subjects fulfilled the entry criteria. Each answered the study questionnaire which elicited a medical history and detailed information regarding past and present marijuana, tobacco, and other substance use. Serum cotinine levels taken previously from a broad sample of subjects responding to this questionnaire were found to have a high degree of correlation with the self-reported smoking status. Based on this information, the subjects were divided into 4 groups: (1) Nonsmokers (NS)—no tobacco or marijuana use in the previous 3 years (n = 14); (2) Tobacco Smokers—current tobacco smokers (at least one cigarette per day on a regular basis for 1 or more years), no marijuana use in the previous 3 years (n = 14); (3) Marijuana Smokers—current heavy, habitual marijuana smokers, no tobacco use in the previous 3 years (n = 19); and (4) Marijuana and Tobacco Smokers—current heavy, habitual marijuana and tobacco smokers (n = 9). Before study participation, written informed consent was given by each subject as approved by the UCLA Human Subject Protection Committee. Within 6 months prior to the day scheduled for bronchoalveolar lavage (BAL), pulmonary function testing, including spirometry, lung volume determination, and diffusing capacity, was performed according to a uniform protocol and with designated equipment. Each subject underwent BAL after topical anesthesia with 0.45 percent tetracaine solution containing epinephrine, and, in some cases, intravenous premedication with atropine and diazepam. A total of 300 ml of sterile saline solution in 50-mi aliquots was rapidly infused into a right middle lobe segmental or subsegmental bronchus followed by immediate recovery of each aliquot with gentle manual suction. The first aliquot of recovered lavage fluid was discarded. Subsequent aliquots were pooled after being strained through a gauze sponge into test tubes containing Hanks’ balanced salt solution with 5 percent fetal calf serum and heparin. A peripheral blood (PB) sample was obtained immediately after BAL.