Enzyme involved in survival of Mycobacterium tuberculosis in mice identified

SCIENCE AND MEDICINE

Needling cocaine addicts helps abstinence ositive findings from a randomised controlled trial of auricular acupuncture for cocaine addiction provide hope for patients who are difficult to treat, researchers report this week. Moreover, the data may have implications for future research. Given the lack of effective conventional treatments, auricular acupuncture is widely used for cocaine addiction. Yet, trials so far have been inconclusive, perhaps because of difficulties with selecting an appropriate control group, note the team led by Arthur Margolin (Yale University School of Medicine, New Haven, CT, USA). So the group compared the US National Acupuncture Detoxification Association (NADA) protocol with auricular acupuncture at “sham” points and with a non-specific relaxation protocol in 82 cocaine and opiate-dependent patients receiving methadone. Patients were offered

P

refuted the possibility that differential treatments five times a week for 8 drop-out of non-responders influweeks, and their urine was tested for enced the findings, note the investicocaine three times a week. gators (Arch Intern Med 2000; 160: Fewer patients completed active 2305–12). Auricular acupuncture (46%) acupuncture may than sham acupuncshow promise long ture (63%) or the Rights were not term, but another relaxation control granted to include study is underway to (81%). Despite this, this image in address this issue, intention-to-treat electronic media. notes Margolin. analysis showed that The data also indipatients randomly Please refer to the cate that sham assigned to the printed journal. acupuncture is not NADA protocol were sufficiently different significantly more from active acupunclikely to have a negature to act as a true tive urine sample But does it work? placebo, which has compared with the implications for further research, says control or sham groups. Margolin. “Given that acupuncture In the last week of treatment, clinical research is in its 53·8% of the active acupuncture infancy . . . obviously, we have much group tested free of cocaine comto learn”, he adds. pared with 23·5% of the sham acupuncture group, and 9·1% of the relaxation control. Further analysis Kelly Morris

Enzyme involved in survival of Mycobacterium tuberculosis in mice identified

U

S researchers report that isocitrate lyase (ICL), an enzyme essential for the metabolism of fatty acids, is vital for the persistence of Mycobacterium tuberculosis in mice. In-vivo metabolism of M tuberculosis is “profoundly influenced by the host response to infection”, which could have implications for treatment of patients with chronic tuberculosis and vaccine development. Studies have suggested that fatty acids may be a major source of energy for M tuberculosis in chron-

ically infected lung tissue. ICL is part of the glyoxylate shunt—one of the pathways used for fatty acid metabolism the other being the ␤-oxidation cycle. John McKinney (Howard Hughes Medical Institute, NY, USA) and colleagues infected immune competent mice with wild-type or ⌬ICL bacteria. They noted that at 2 weeks mice infected with the ⌬ICL mutant and wild-type bacteria showed no difference but by 16 weeks the lungs of the wild-type mice were “grossly inflamed and

enlarged, with numerous and expanding tubercles” (Nature 2000 406: 736–38). The researchers suggest that ICL is important for survival of M tuberculosis during the persistent phase of infection. They also note that “the phenotype of ⌬ICL bacteria was more pronounced in activated than resting macrophages”, which suggests a direct link to the hosts immune status and the need for ICL. Haroon Ashraf

“Dumpers” may confound clinical trial results heating patients may be confounding clinical trial results, a new study suggests. The study finds that one in three patients participating in a clinical trial were “dumping” their medications before clinic visits and then claiming they had taken their medication as instructed when, in fact, they had not. The study looked at the medication use of 236 smokers participating in a larger trial assessing the effect that smoking-cessation counselling and regular use of an inhaled bronchodilator has on the progression of chronic obstructive pulmonary disease. The patients were given inhalers equipped with a device called a

C

658

Nebulizer Chronolog (Medtrac Technologies, Lakewood, CO, USA), which records the date and time an inhaler is used. 135 of the 236 patients were told of the device’s ability to log the date and time of use, while 101 were told that the device monitored only the amount of drug used (Chest 2000; 118: 290–95). Lead author Michael Simmons (Los Angeles, CA, USA) says the original purpose of the study was to see what effect counselling and clinic visits had on inhaler use. “We did not expect this kind of behaviour”, he says, and at first the researchers suspected the device had malfunctioned. But when the researchers went back

over the data, they discovered that 30 (29%) of the 101 patients who did not know of the device’s date-recording and time-recording abilities had fired their inhalers 100 or more times in a 3 h period, typically shortly before a clinic visit, apparently so the clinic staff would think the patients had used their inhalers regularly. In contrast, only one of the patients who knew about the device’s capabilities had “dumped” medicine. The researchers could not identify any factors that would help researchers identify which patients are likely to be medication “dumpers”. Michael McCarthy

THE LANCET • Vol 356 • August 19, 2000

For personal use only. Not to be reproduced without permission of The Lancet.