Serum nicotine and cotinine levels during nicotine-patch therapy.

We related serum nicotine and cotinine levels while subjects were smoking their usual numbers of cigarettes to levels while wearing a nicotine patch under carefully controlled, smoke-free conditions in a clinical research center. Twenty-four volunteers who needed intensive treatment for severe nicotine dependence were admitted to the clinical research center and were treated with a 22 mg transdermal nicotine patch each day and an intensive smoking-cessation program. Serum nicotine and cotinine levels, withdrawal symptoms, and hours and quality of sleep were noted. The steady-state serum nicotine and cotinine levels produced with the nicotine patch were lower than those observed when the subjects were smoking. Mean nicotine and cotinine levels were inversely related to mean withdrawal scores for the first 6 days. A fixed dose of transdermal nicotine will not be effective for all smokers. Individualization of therapy should be based on objective biologic measures such as serum cotinine and subjective assessment of withdrawal relief.

Comparison of cardiac troponin I and lactate dehydrogenase isoenzymes for the late diagnosis of myocardial injury.

Cardiac troponin I (cTnI) is a highly specific marker that is elevated in the blood for several days following myocardial infarction. The lactate dehydrogenase (LD) isoenzyme 1 to isoenzyme 2 ratio (LD1/LD2) is the established marker for the late diagnosis of myocardial infarction. In this study, the sensitivity of cardiac troponin I (cTnI) and LD1/LD2 were compared as late markers of myocardial injury over a 5-day period in 36 patients admitted with a diagnosis of myocardial infarction to the coronary care unit. Over this period, the sensitivity of cTnI was significantly greater than that of LD1/LD2 (P < .05). The concurrent elevation of both cardiac markers of the five day period range from 53.1% to 79.4%. However, this low concordance was largely due to an LD1/LD2 < 1 in the presence of an increased cTnI. The average discordance over the 5-day period was 29.5%. Because cardiac troponin I (cTnI) has greater sensitivity than lactate dehydrogenase isoenzymes for delayed diagnosis of myocardial injury and is a more cost-effective test, the authors recommend it as a test of choice in this setting.

Bisalbuminuria in an adult with bisalbuminemia and nephrotic syndrome.

Bisalbuminemia (or alloalbuminemia) is a relatively rare hereditary or acquired condition characterized by the presence of two distinct albumin bands, or, less commonly, a single widened albumin band, after agarose gel electrophoresis of serum. Bisalbumins are caused by point- or chain-mutations that occur with a population frequency of 1:10,000 to 1:1000. Although no adverse clinical effects have been attributed to bisalbumins, some albumin variants have altered affinity for steroid hormones, thyroxine, or drugs. We report a case of bisalbuminuria in a 25-year-old man with bisalbuminemia and nephrotic syndrome.

A solid phase extraction method for determination of nicotine in serum and urine by isotope dilution gas chromatography/mass spectrometry with selected ion monitoring.

A rapid method for measuring nicotine concentration in serum and urine is described. Deuterated nicotine is used as an internal standard. Nicotine and deuterated nicotine are extracted using a copolymeric-bonded phase silica column. The extract is analysed by gas chromatography coupled with mass spectrometry (GC/MS) operating in selected ion monitoring mode. The method has a lower limit of detection of approximately 2 micrograms/L and is linear to at least 2000 micrograms/L. Within-run percentage coefficients of variation (% CV) are < 4 in both assays over a nicotine concentration range of 10-2000 micrograms/L. Between-run % CV in the serum assay are 5.4, 5.2, 4.8 and 5.9, respectively, at nicotine concentrations of 10, 15, 25, and 50 micrograms/L. Between-run % CV in the urine assay are 5.9, 4.5, 2.7 and 5.2, respectively, at nicotine concentrations of 100, 250, 500, and 2000 micrograms/L. The absolute recovery of nicotine is 61 +/- 6% (mean +/- SD) over the range of 10-250 micrograms/L. The assay has been used to measure serum nicotine concentrations and 24-h urinary excretion of nicotine to monitor the extent of replacement in subjects receiving transdermal nicotine therapy for smoking cessation.

Malignancies arising in oncocytic schneiderian papillomas: a report of 2 cases and review of the literature.

Oncocytic schneiderian papillomas (OSPs) are uncommon benign neoplasms that arise from the sinonasal schneiderian epithelium. Malignancies arising in OSPs are rare, and, to our knowledge, only 14 such instances have been reported in the medical literature. We report 2 additional cases--a small cell carcinoma and a sinonasal undifferentiated carcinoma arising in OSPs and presenting synchronously with the benign neoplasm. The potential for malignant transformation in OSPs is small, but warrants that these papillomas be completely excised to exclude a coexisting carcinoma.

Drugs detected in patients suspected of acute intoxication.

Drug screens were performed for 434 adult patients who presented to the Parkland Memorial Hospital Emergency Department with suspected acute drug overdose. The screening consisted of analysis of urine by automated high performance liquid chromatography (REMEDi) in combination with qualitative EMIT immunoassays. Selected patients also had ethanol measured in blood, salicylate and acetaminophen measured in serum, and urine specimens analyzed qualitatively for cannabinoids. Most patients (83.4%), regardless of age, race, or gender, had evidence of consumption of at least one drug. The drugs detected most often were ethanol (30.0%) and cocaine (23.7%). At least one of the nine most common drugs-of-abuse (amphetamines, barbiturates, benzodiazepines, cannabinoids, cocaine, ethanol, opiates, opioids, and phencyclidine) was detected in 64.5% of the specimens, and combinations of these drugs were present in 45.4%. For most drugs, age, gender, ethnicity, time of day, day of week, and indication for screening could not be used to predict the drug screen result.

Assessment of human exposure to gaseous pollutants.

A mathematical model to aid in assessment of human environmental exposure to volatile organic substances is presented. The model simulates the convective and diffusive transport of gas from the ambient environment into the human body by way of the respiratory and circulatory systems. Data required include easily obtained physical and chemical properties of substances as well as several estimated or measured physiological parameters. Transient and steady-state tissue concentrations resulting from an input atmospheric partial pressure are predicted. From these concentrations, an effective dose may be calculated, allowing for the determination of an exposure-response relationship based upon independently obtained dose-response data. The model's results compare favorably to experimental data on oxygen and halothane. Steady-state conditions are reached very rapidly. These results suggest that uptake of these substances is limited by both ventilation and perfusion. rates are demonstrated to be essentially linear within the current neighborhoods. Conditions in which the primary processes of ventilation, diffusion, perfusion, and elimination limit uptake of gases are considered. Expressions describing the conditions necessary for a single process to limit gas uptake are derived. Accompanying equations for estimating tissue concentrations under these limiting conditions are presented.