We evaluated the feasibility and quality of uncomplicated hypertension care based on telemedicine in a rural area of northern Sweden. The intervention subjects were 91 consecutive patients with primary hypertension. For comparison, 182 age- and sex-matched patients with hypertension were randomly selected from a similar health centre. The telemedicine equipment consisted of a video link between the physician and the patients, supported by a system for accessing medical data via the Internet. During a 21-month study period, telemedicine was used in 270 (91%) of the 297 consultations in the intervention group. All health personnel involved in the telemedicine treatment rated the method as feasible. Both systolic and diastolic blood pressure improved in the two groups during the study period. In the intervention group, a higher proportion had their blood pressure within treatment goals (systolic blood pressure <140 mmHg, diastolic blood pressure <90 mmHg) both at baseline and at follow-up than in the comparison group. An adjusted multivariate model (adjustment for sex, age, time between visits, change in number of drugs between first and last visit, blood pressure at first visit) showed that the intervention group had a higher probability (OR 2.7, 95% CI 1.4-5.2) of reaching the target blood pressure levels than the reference group. Treatment of hypertension by means of telemedicine was quite feasible and at least as effective as face-to-face consultations with a physician.
A newly developed liquid chromatography-tandem mass spectrometry (LC-MS-MS) method was used to study 3000 human urine samples from 3 different populations for 23 analytes covering phenylethylamines, benzylpiperazine, and non-benzodiazepine hypnotics. Direct injection of urine and LC-MS-MS with rapid chromatography and atmospheric pressure chemical ionization was used in the screening step. The cutoff levels were chosen to be at the limit of detection for most analytes to identify as many positive samples as possible. Typically one ion transition was monitored from the pseudo-molecular ions in the multiple reaction monitoring mode. Of the 797 positive screening findings, 518 (65%) were confirmed by a second LC-MS-MS analysis including solid-phase extraction. Confirmed analytical findings included 22 cases positive for N-benzylpiperazine, 88 for 3,4-methylenedioxy-N-methylamphetamine and metabolites, 4 for 1-phenyl-2-butylamine, 24 for zolpidem and metabolites, 118 for zopiclone and metabolites, and 1 for zaleplon. In conclusion, LC-MS-MS was found to be a robust alternative for drugs of abuse screening, offering high sensitivity compared with immunochemical screening methodology.
There is a limit in the number of substances detected by commercially available reagents. It is therefore important to have other, complementary techniques. Liquid chromatography-tandem mass spectrometry (LC-MS-MS) may offer one possibility. An LC-MS-MS procedure based on the detection of positive ions after atmospheric pressure chemical ionization (APCI) was developed for direct measurement of 3,4-methylenedioxymethamphetamine (MDMA) and 3,4-methylenedioxyamphetamine in urine. It was compared with Online Amphetamines. The LC-MS-MS methodology showed improved sensitivity (1 00-ng/mL cutoff and specificity with a coefficient of variation of 10%. It was compared to the immunochemical analysis using 1000 clinical patient urine samples. The positive samples were confirmed by gas chromatography-mass spectrometry. The LC-MS-MS method detected almost four times as many samples positive for MDMA compared to the immunochemical method, with no false positives and one false negative. Our study suggests that LC-MS-MS offers an alternative to immunochemical methods in drug of abuse screening.
Zopiclone is a benzodiazepine-like hypnotic that was believed not to have any abuse potential. Nevertheless, during the past few years there have been an increasing number of reports on the abuse and misuse of zopiclone. Despite this, methods for screening analysis in urine are lacking. To investigate whether UV detection would be possible to use for this purpose, a liquid chromatography method with ultraviolet detection for analyzing zopiclone and its urinary metabolites was developed, with liquid chromatography-mass spectrometry for confirmation. The method was used for analyzing samples from subjects receiving methadone. The limits of detection were approximately 100 ng/mL in control urine samples and 500 ng/mL in urine samples from subjects receiving methadone. However, due to the high background in these patients' urine, a single therapeutic dose was impossible to detect.
By allowing for direct injection of urine, liquid chromatography-tandem mass spectrometry (LC-MS-MS) with atmospheric-pressure chemical ionization has proven to be useful for analysis of drugs of abuse in human urine. The purpose of this study was to evaluate this technique by direct screening for 23 different substances (phenylethylamines, hypnotics, and N-benzylpiperazine) in urine samples. It was possible to achieve lower detection limits compared with commercial immunochemical methods. There was a linear response for all analytes with an intraday coefficient of variation of about 16%, and the gradient elution gave a variability in relative retention time of about 1%. Positive results were confirmed by reanalysis including sample preparation by solid-phase extraction. Among the 529 authentic urine samples analyzed, 35 samples were screened positive for phenylethylamines, and 20 for hypnotics. Of these, 23 (66%) samples were confirmed to be positive for phenylethylamines, and 11 (55%) for hypnotics. This study demonstrates that LC-MS-MS is a valuable complement to immunochemical screening analysis, especially for substances for which immunochemical methods are not yet available or when an increased sensitivity is needed.
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