1474
retrospective study is reassuring for those advocating mammographic screening in younger women. However, Miller says that Kopans’ group have "overinterpreted" their findings. Only a randomised controlled study in a large population is likely to provide unequivocal data to answer this question. Miller believes alone.6 This
that future research should concentrate on the treatment of cancers detected after screening. Most importantly, staging procedures should be refined, perhaps by the use of oncogene markers, to enable more accurate assessment of the efficacy of different
therapeutic regimens. 1. Editorial. Breast cancer screening in women under 50. Lancet 1991; 337: 1575-76. 2. Miller AB. Breast cancer screening in women under 50. Lancet 1991; 338: 113. 3. Merz B. Author of Canadian Breast Cancer Study retracts warnings. JNCI 1992; 84: 832-34. 4. Day NE, Duffy SW. Breast screening in women under 50. Lancet 1991; 338: 113-14. 5. Kopans DB. Breast screening in women under 50. Lancet 1991; 338: 447. 6. Anonymous. Mammography and new treatments highlight conference. Cancer Weekly 1992; May 4.
Statistics. A comparison of trends in and levels of mortality from these two sources thus formed the basis of an assessment of the representativeness of SEER data.2 The two sets of data reflected the same trend for all sites but there were some race, sex, and site-specific differences between them in size of trends in and levels of mortality. No clear pattern of non-representativeness emerged, which suggests that the differences are due to a variety of factors-ie, the SEER populations could have differed from the national population in demographic features, environmental exposures, or socioeconomic status. 1. 2.
Reynolds T. Cancer data bases expanding. J Natl Cancer Inst 1992; 84: 839-41. Frey CM, McMillen MM, Cowan CD, Horm JW, Kessler LG. Representativeness of the Surveillance, Epidemiology and End Results program data: recent trends in cancer mortality rates. J Natl Cancer Inst 1992; 84: 872-77.
Consumer goods containing radioactive substances HIV infection from dentist to
patients
The US Centers for Disease Control has concluded that David Acer, the Florida dentist with AIDS, was the most likely source of infection for at least 5 of his patients who acquired the disease while being treated by him. These 5 had no other known identifiable risk factors for the infection apart from invasive dental procedures; 3 others, who also became HIV positive had other known risk factors.1,2 The conclusion was based on molecular analyses of the virus from the dentist, from 7 of his patients, and from 35 local controls (AIDS patients from 2 HIV clinics sited within 90 miles of Acer’s practice). Virus from the dentist had closer similarities in the G-V3 section of the envelope gene with those from 5 of his patients than with those from the other 2 or the 35 local controls. When signature analysis of the viral sequences was done (an analysis of the aminoacid sequences in the V3 region), again the viruses from the dentist and the same 5 patients stood apart from the other viruses. The CDC conclusion has been queried2°3on several grounds. One is based on the way the control viruses were sampled. DNA of viruses from Acer and his patients were extracted from the white blood cells and cloned, whereas those from the local controls were tested without the cloning step. Since every patient infected with AIDS has a "swarm" of viruses differing from each other by a few DNA base-pairs rather than a single variant, the argument is that the variants identified in the local controls may represent the swarm rather than a specific variant. Other concerns were about the length of the nucleotide sequence analysed and the statistical limitations of the methods used for the cluster analyses. Even if there should be agreement that the dentist was the source of infection for some of his patients, how the transmission occurred has not been worked out. 1. Ou
Chin-Yih, Ciesielski CA, Myers G, et al. Molecular epidemiology of HIV transmission in a dental practice. Science 1992; 256: 1165-71. 2. Palca J. CDC closes the case of the Florida dentist. Science 1992; 256: 1130-31. 3. Smith TF, Waterman MS. The continuing case of the Florida dentist. Science 1992; 256: 1155-56.
Ionisation chamber smoke detectors, radioluminous clocks and watches, and compasses containing tritium light sources are some of the consumer goods that contain radioactive substances. The National Radiological Protection Board provides advice to manufacturers and suppliers who voluntarily offer their products for review. It is impossible to ensure that these goods are used and disposed of in accordance with the manufacturers’ instructions, so the Government intends to make approval of the goods compulsory before they are supplied to the public. In its assessment the Board will concentrate on possibility of harm during normal use and disposal but will also pay attention to the possibility of hazards or misuse. The standards for its approval of various goods are given in a booklet1 published this week. 1. Board statement
on approval of consumer goods containing radioactive substances. Documents of the NRPB 1992, vol 3, no 2. London: HM Stationery Office, 1992. Pp 73. £10. ISBN 0-85951-350-5.
Quinolone drug withdrawn worldwide Abbott Laboratories is voluntarily withdrawing trom the marKet its quinolone derivative temafloxacin (Omniflox) after reports of serious adverse reactions, most of which have been reported in the USA, where the drug has been marketed since mid-February. Since then there have been about 50 reports of severe adverse reactions, including three deaths(these deaths have not been directly attributed to the drug). There were several cases of severe hypoglycaemia, especially in elderly patients with impaired renal function. Other adverse reactions were haemolytic anaemia, hepatic dysfunction, and kidney dysfunction that was serious enough for about half the patients to require dialysis. There were also reports of allergic reactions, some of which resulted in anaphylaxis. The drug is also marketed in Italy, the UK, Germany, Ireland, Sweden, and Argentina.
Representativeness of SEER data The US Surveillance, Epidemiology, and End Results (SEER) data system was set up in 1973. It forms the country’s primary source of national data on trends in cancer incidence and survival. It is made up of nine registries selected for their epidemiologically important subgroups and covering about 10% of the US population. However, there has been a lack of data on Hispanics, on rural populations generally, and on rural black populations in particular, and there are plans to add a new area with a large Hispanic population later this year.1 Apart from adequacy of coverage of population subgroups, an important point about the SEER data is that they should be representative of the whole US population, especially since they are used to establish baselines and projections for the future, for the planning of health-service requirements. SEER data include details of mortality. Information on mortality (but not on incidence or survival) is also available from the National Center for Health
HIV-infected children For the non-specialist, diagnosis and management of the HIV-infected child can provide special difficulties. Until trials in children are completed, some management policies have to be extrapolated from findings in adults. The difficulty in establishing HIV serological status in infants born to infected mothers compounds the issue. In HIV-infected children Pneurnocystis carinii pneumonia arises most commonly at age 3-6 months and carries a high mortality rate. Is prophylaxis indicated? Two specialists,l Dr Diana Gibbs and Dr Sam Walters, who have compiled guidelines for the management of HIV-infected children advise that, despite lack of data, trimethoprim-sulphamethoxazole be given prophylactically to children of uncertain HIV-infection status from age 3 weeks (after hyperbilirubinaemia has subsided). Their guidelines cover not only the management of HIV infection
retrospective study is reassuring for those advocating mammographic screening in younger women. However, Miller says that Kopans’ group have "overinterpreted" their findings. Only a randomised controlled study in a large population is likely to provide unequivocal data to answer this question. Miller believes alone.6 This
that future research should concentrate on the treatment of cancers detected after screening. Most importantly, staging procedures should be refined, perhaps by the use of oncogene markers, to enable more accurate assessment of the efficacy of different
therapeutic regimens. 1. Editorial. Breast cancer screening in women under 50. Lancet 1991; 337: 1575-76. 2. Miller AB. Breast cancer screening in women under 50. Lancet 1991; 338: 113. 3. Merz B. Author of Canadian Breast Cancer Study retracts warnings. JNCI 1992; 84: 832-34. 4. Day NE, Duffy SW. Breast screening in women under 50. Lancet 1991; 338: 113-14. 5. Kopans DB. Breast screening in women under 50. Lancet 1991; 338: 447. 6. Anonymous. Mammography and new treatments highlight conference. Cancer Weekly 1992; May 4.
Statistics. A comparison of trends in and levels of mortality from these two sources thus formed the basis of an assessment of the representativeness of SEER data.2 The two sets of data reflected the same trend for all sites but there were some race, sex, and site-specific differences between them in size of trends in and levels of mortality. No clear pattern of non-representativeness emerged, which suggests that the differences are due to a variety of factors-ie, the SEER populations could have differed from the national population in demographic features, environmental exposures, or socioeconomic status. 1. 2.
Reynolds T. Cancer data bases expanding. J Natl Cancer Inst 1992; 84: 839-41. Frey CM, McMillen MM, Cowan CD, Horm JW, Kessler LG. Representativeness of the Surveillance, Epidemiology and End Results program data: recent trends in cancer mortality rates. J Natl Cancer Inst 1992; 84: 872-77.
Consumer goods containing radioactive substances HIV infection from dentist to
patients
The US Centers for Disease Control has concluded that David Acer, the Florida dentist with AIDS, was the most likely source of infection for at least 5 of his patients who acquired the disease while being treated by him. These 5 had no other known identifiable risk factors for the infection apart from invasive dental procedures; 3 others, who also became HIV positive had other known risk factors.1,2 The conclusion was based on molecular analyses of the virus from the dentist, from 7 of his patients, and from 35 local controls (AIDS patients from 2 HIV clinics sited within 90 miles of Acer’s practice). Virus from the dentist had closer similarities in the G-V3 section of the envelope gene with those from 5 of his patients than with those from the other 2 or the 35 local controls. When signature analysis of the viral sequences was done (an analysis of the aminoacid sequences in the V3 region), again the viruses from the dentist and the same 5 patients stood apart from the other viruses. The CDC conclusion has been queried2°3on several grounds. One is based on the way the control viruses were sampled. DNA of viruses from Acer and his patients were extracted from the white blood cells and cloned, whereas those from the local controls were tested without the cloning step. Since every patient infected with AIDS has a "swarm" of viruses differing from each other by a few DNA base-pairs rather than a single variant, the argument is that the variants identified in the local controls may represent the swarm rather than a specific variant. Other concerns were about the length of the nucleotide sequence analysed and the statistical limitations of the methods used for the cluster analyses. Even if there should be agreement that the dentist was the source of infection for some of his patients, how the transmission occurred has not been worked out. 1. Ou
Chin-Yih, Ciesielski CA, Myers G, et al. Molecular epidemiology of HIV transmission in a dental practice. Science 1992; 256: 1165-71. 2. Palca J. CDC closes the case of the Florida dentist. Science 1992; 256: 1130-31. 3. Smith TF, Waterman MS. The continuing case of the Florida dentist. Science 1992; 256: 1155-56.
Ionisation chamber smoke detectors, radioluminous clocks and watches, and compasses containing tritium light sources are some of the consumer goods that contain radioactive substances. The National Radiological Protection Board provides advice to manufacturers and suppliers who voluntarily offer their products for review. It is impossible to ensure that these goods are used and disposed of in accordance with the manufacturers’ instructions, so the Government intends to make approval of the goods compulsory before they are supplied to the public. In its assessment the Board will concentrate on possibility of harm during normal use and disposal but will also pay attention to the possibility of hazards or misuse. The standards for its approval of various goods are given in a booklet1 published this week. 1. Board statement
on approval of consumer goods containing radioactive substances. Documents of the NRPB 1992, vol 3, no 2. London: HM Stationery Office, 1992. Pp 73. £10. ISBN 0-85951-350-5.
Quinolone drug withdrawn worldwide Abbott Laboratories is voluntarily withdrawing trom the marKet its quinolone derivative temafloxacin (Omniflox) after reports of serious adverse reactions, most of which have been reported in the USA, where the drug has been marketed since mid-February. Since then there have been about 50 reports of severe adverse reactions, including three deaths(these deaths have not been directly attributed to the drug). There were several cases of severe hypoglycaemia, especially in elderly patients with impaired renal function. Other adverse reactions were haemolytic anaemia, hepatic dysfunction, and kidney dysfunction that was serious enough for about half the patients to require dialysis. There were also reports of allergic reactions, some of which resulted in anaphylaxis. The drug is also marketed in Italy, the UK, Germany, Ireland, Sweden, and Argentina.
Representativeness of SEER data The US Surveillance, Epidemiology, and End Results (SEER) data system was set up in 1973. It forms the country’s primary source of national data on trends in cancer incidence and survival. It is made up of nine registries selected for their epidemiologically important subgroups and covering about 10% of the US population. However, there has been a lack of data on Hispanics, on rural populations generally, and on rural black populations in particular, and there are plans to add a new area with a large Hispanic population later this year.1 Apart from adequacy of coverage of population subgroups, an important point about the SEER data is that they should be representative of the whole US population, especially since they are used to establish baselines and projections for the future, for the planning of health-service requirements. SEER data include details of mortality. Information on mortality (but not on incidence or survival) is also available from the National Center for Health
HIV-infected children For the non-specialist, diagnosis and management of the HIV-infected child can provide special difficulties. Until trials in children are completed, some management policies have to be extrapolated from findings in adults. The difficulty in establishing HIV serological status in infants born to infected mothers compounds the issue. In HIV-infected children Pneurnocystis carinii pneumonia arises most commonly at age 3-6 months and carries a high mortality rate. Is prophylaxis indicated? Two specialists,l Dr Diana Gibbs and Dr Sam Walters, who have compiled guidelines for the management of HIV-infected children advise that, despite lack of data, trimethoprim-sulphamethoxazole be given prophylactically to children of uncertain HIV-infection status from age 3 weeks (after hyperbilirubinaemia has subsided). Their guidelines cover not only the management of HIV infection
