797
On the contrary, this is a most welcome development. The legal and accountancy professions do not protest when their members go off to work in government, management, or other fields. Such actions ensure that the attitudes and experiences of people from those two professions are widely disseminated throughout society. The main trouble with science is that very few people outside science have any concept of what science can offer or any understanding of what it involves. This situation will change only when many individuals with good scientific training move to other careers, especially in management, finance, government, and the media. Only then will science come to be more widely understood. We should be training far more scientists than could possibly be employed within science itself, and should be delighted rather than dismayed when they take their scientific training into other realms. Efamol Research Inc, Kentville, Nova Scotia, Canada B4N 4H8
DAVID F. HORROBIN
Bovine spongiform encephalopathy SiR,—I would like to correct your Round the World correspondent (Feb 10, p 343) on two points. First, your correspondent alleges that Germany has banned imports of British beef and that thirteen countries have followed. This is not so. Germany, which did impose some import restrictions in November last year, have amended their requirements and now accept boneless British beef without any restriction. No other country has placed any restriction on our beef. Second, the specific temperatures at which rendering systems operate have never been established in UK law. There have been changes in rendering processes over the years, in particular a move from batch to continuous rendering, but these have been introduced as a result of commercial pressures and technological developments. More importantly, both batch and continuous systems operate at a range of temperatures (batch, 100-150°C; continuous, lOO-145OC). The role of rendering plants in the epidemiology of bovine spongiform encephalopathy is being investigated and the results will be published on completion of the work. Ministry of Agriculture, Fisheries and Food, Tolworth, Surbiton, Surrey KT6 7NF, UK
K. C. MELDRUM Chief Veterinary Officer
Transmissible agent of Kaposi
SiR,—The conclusion reached by Professor Beral and her colleagues (Jan 20, p 123) that a separately transmissible agent causes Kaposi’s sarcoma (KS) was apparent early in the AIDS epidemic. A prediction! that KS would be detected with increased frequency outside the context of HIV infection has been confirmed by Dr Friedman-Kien and colleagues (Jan 20, p 168) and by the papers they reference. As implied by Beral et al we consider the decrease in KS among AID S patients to be a natural consequence of the difference of transmissibility between HIV and the unknown agent which became apparent after spread from the initial focus of the most sexually active homosexual/bisexual men (ie, those most likely to be infected with both agents). By comparing the over-representation of KS in AIDS with its frequency after organ transplantation, Beral et al imply that immunosuppression alone accounts for a "baseline", albeit low, frequency of KS. It may be that immunosuppressive therapies are associated with KS, the risk depending on geographical region, time period, and clinical situation. A review of HIV-negative KS patients treated in our region revealed four known to have received previous steroid therapy, out of hundreds of such treated patients at risk. On the other hand, two of these four had also received blood transfusions. As previously noted,reports of post-transfusion KS correspond in time to the greatly increased use of transfusion therapy to increase the chance of graft survival. There is no a priori reason to assume that the spread of HIV and the KS agent are exactly parallel in time, and transfusion-borne KS before the AIDS epidemic should receive serious evaluation. A study in Sweden3 indicated a two-fold increase in the incidence of KS of the elderly, beginning at the end of the 1960s. This is also consistent with the increased spread of a KS agent in recent decades-an agent which may have been present in western countries at least since the time of Kaposi’s original description in 1872. The KS lesion begins with an increase in blood capillaries and lymphatic channels and the end-result is a spindle-cell tumour which may develop nuclear atypia. A similar histological progression has been noted in avian haemangiomatosis, which shows striking clinical similarities to KS and is caused by a retrovirus of the avian leukosis groUp.2 Both diseases are associated with lymphoma. Thus retroviruses, including those not associated with primate disease, deserve consideration in the search for a KS agent. Departments of Pathology and Dermatology, University Hospital,
Responsibility for food safety SiR,—Your note on food safety (March 3, p 531) makes a mistake in believing that part I of the report of the Committee on the Microbiological Safety of Food recommends that responsibility for food safety should be transferred from the Ministry of Agriculture, Fisheries and Food (MAFF) to the Department of Health (DH). Our recommendation is rather less sweeping. The relevant paragraph (5.41) of the report reads, in part: "The Committee has also debated whether MAFF rather than DH should take the lead with the committees concerned with microbiological food hazards. We are clearly of the opinion that the lead should be with DH (R5.3)... This is not in any way to understate the vital part that we consider MAFF will need to play in dealing with the causes of the contamination of food eg, by reducing the levels of contamination of food animals and of crops. These are clearly areas where MAFF will need to take the lead in deciding what action is necessary once a decision has been taken that a public health risk exists." Office of the Vice-Chancellor, The University of Manchester, Manchester M13 9PL, UK
MARK RICHMOND
, A poorly reproduced document listing the committee’s recommendations and the Government’s response was all that the Department of Health saw fit to supply us with-hence our cautious equating of the undefined "lead" with "responsibility".-ED. L.
sarcoma
MICHAEL DICTOR NIELS BENDSÖE
S-221 85 Lund, Sweden
1. Dictor M. Kaposi’s sarcoma: a trifactorial model. Med Hypoth 1987; 22: 429-41. 2. Dictor M, Jarplid B. The cause of Kaposi’s sarcoma: an avian retroviral analog. JAm Acad Dermatol 1988; 18: 399-402. 3. Dictor M, Attewell R. Epidemiology of Kaposi’s sarcoma in Sweden prior to the
acquired immunodeficiency syndrome. Int J Cancer 1988; 42: 346-51.
SIR,-We read with interest Dr Friedman-Kien and colleagues’ (Jan 20, p 168) of Kaposi’s sarcoma (KS) in six HIVseronegative homosexual men. We can add a further case. A 58-year-old bisexual American man presented in 1985 to the immunology clinic of the Royal Perth Hospital, Western Australia, with a 17-year history of biopsy-proven KS in the region of the left axilla and overlying the left scapula. In 1968, aged 41, he had been treated for secondary syphilis and had a Jarisch-Herxheimer reaction with associated nephrotic syndrome, at which time skin lesions were first noted. The glomerulonephritis resolved spontaneously but the KS lesions persisted, with further confirmatory biopsies in 1974 and 1984. Sera from 1985 and 1987 were seronegative for HIV-1by enzyme immunoassays (Abbott, Genetic Systems, Wellcome) and by western blot. T-lymphocyte studies in 1985 revealed a T4 cell count
report
within the normal range and
a
T4/T8
ratio of 2-3. Normal
delayed-type hypersensitivity was demonstrated in 1985 (’Multitest CMI’).
On the contrary, this is a most welcome development. The legal and accountancy professions do not protest when their members go off to work in government, management, or other fields. Such actions ensure that the attitudes and experiences of people from those two professions are widely disseminated throughout society. The main trouble with science is that very few people outside science have any concept of what science can offer or any understanding of what it involves. This situation will change only when many individuals with good scientific training move to other careers, especially in management, finance, government, and the media. Only then will science come to be more widely understood. We should be training far more scientists than could possibly be employed within science itself, and should be delighted rather than dismayed when they take their scientific training into other realms. Efamol Research Inc, Kentville, Nova Scotia, Canada B4N 4H8
DAVID F. HORROBIN
Bovine spongiform encephalopathy SiR,—I would like to correct your Round the World correspondent (Feb 10, p 343) on two points. First, your correspondent alleges that Germany has banned imports of British beef and that thirteen countries have followed. This is not so. Germany, which did impose some import restrictions in November last year, have amended their requirements and now accept boneless British beef without any restriction. No other country has placed any restriction on our beef. Second, the specific temperatures at which rendering systems operate have never been established in UK law. There have been changes in rendering processes over the years, in particular a move from batch to continuous rendering, but these have been introduced as a result of commercial pressures and technological developments. More importantly, both batch and continuous systems operate at a range of temperatures (batch, 100-150°C; continuous, lOO-145OC). The role of rendering plants in the epidemiology of bovine spongiform encephalopathy is being investigated and the results will be published on completion of the work. Ministry of Agriculture, Fisheries and Food, Tolworth, Surbiton, Surrey KT6 7NF, UK
K. C. MELDRUM Chief Veterinary Officer
Transmissible agent of Kaposi
SiR,—The conclusion reached by Professor Beral and her colleagues (Jan 20, p 123) that a separately transmissible agent causes Kaposi’s sarcoma (KS) was apparent early in the AIDS epidemic. A prediction! that KS would be detected with increased frequency outside the context of HIV infection has been confirmed by Dr Friedman-Kien and colleagues (Jan 20, p 168) and by the papers they reference. As implied by Beral et al we consider the decrease in KS among AID S patients to be a natural consequence of the difference of transmissibility between HIV and the unknown agent which became apparent after spread from the initial focus of the most sexually active homosexual/bisexual men (ie, those most likely to be infected with both agents). By comparing the over-representation of KS in AIDS with its frequency after organ transplantation, Beral et al imply that immunosuppression alone accounts for a "baseline", albeit low, frequency of KS. It may be that immunosuppressive therapies are associated with KS, the risk depending on geographical region, time period, and clinical situation. A review of HIV-negative KS patients treated in our region revealed four known to have received previous steroid therapy, out of hundreds of such treated patients at risk. On the other hand, two of these four had also received blood transfusions. As previously noted,reports of post-transfusion KS correspond in time to the greatly increased use of transfusion therapy to increase the chance of graft survival. There is no a priori reason to assume that the spread of HIV and the KS agent are exactly parallel in time, and transfusion-borne KS before the AIDS epidemic should receive serious evaluation. A study in Sweden3 indicated a two-fold increase in the incidence of KS of the elderly, beginning at the end of the 1960s. This is also consistent with the increased spread of a KS agent in recent decades-an agent which may have been present in western countries at least since the time of Kaposi’s original description in 1872. The KS lesion begins with an increase in blood capillaries and lymphatic channels and the end-result is a spindle-cell tumour which may develop nuclear atypia. A similar histological progression has been noted in avian haemangiomatosis, which shows striking clinical similarities to KS and is caused by a retrovirus of the avian leukosis groUp.2 Both diseases are associated with lymphoma. Thus retroviruses, including those not associated with primate disease, deserve consideration in the search for a KS agent. Departments of Pathology and Dermatology, University Hospital,
Responsibility for food safety SiR,—Your note on food safety (March 3, p 531) makes a mistake in believing that part I of the report of the Committee on the Microbiological Safety of Food recommends that responsibility for food safety should be transferred from the Ministry of Agriculture, Fisheries and Food (MAFF) to the Department of Health (DH). Our recommendation is rather less sweeping. The relevant paragraph (5.41) of the report reads, in part: "The Committee has also debated whether MAFF rather than DH should take the lead with the committees concerned with microbiological food hazards. We are clearly of the opinion that the lead should be with DH (R5.3)... This is not in any way to understate the vital part that we consider MAFF will need to play in dealing with the causes of the contamination of food eg, by reducing the levels of contamination of food animals and of crops. These are clearly areas where MAFF will need to take the lead in deciding what action is necessary once a decision has been taken that a public health risk exists." Office of the Vice-Chancellor, The University of Manchester, Manchester M13 9PL, UK
MARK RICHMOND
, A poorly reproduced document listing the committee’s recommendations and the Government’s response was all that the Department of Health saw fit to supply us with-hence our cautious equating of the undefined "lead" with "responsibility".-ED. L.
sarcoma
MICHAEL DICTOR NIELS BENDSÖE
S-221 85 Lund, Sweden
1. Dictor M. Kaposi’s sarcoma: a trifactorial model. Med Hypoth 1987; 22: 429-41. 2. Dictor M, Jarplid B. The cause of Kaposi’s sarcoma: an avian retroviral analog. JAm Acad Dermatol 1988; 18: 399-402. 3. Dictor M, Attewell R. Epidemiology of Kaposi’s sarcoma in Sweden prior to the
acquired immunodeficiency syndrome. Int J Cancer 1988; 42: 346-51.
SIR,-We read with interest Dr Friedman-Kien and colleagues’ (Jan 20, p 168) of Kaposi’s sarcoma (KS) in six HIVseronegative homosexual men. We can add a further case. A 58-year-old bisexual American man presented in 1985 to the immunology clinic of the Royal Perth Hospital, Western Australia, with a 17-year history of biopsy-proven KS in the region of the left axilla and overlying the left scapula. In 1968, aged 41, he had been treated for secondary syphilis and had a Jarisch-Herxheimer reaction with associated nephrotic syndrome, at which time skin lesions were first noted. The glomerulonephritis resolved spontaneously but the KS lesions persisted, with further confirmatory biopsies in 1974 and 1984. Sera from 1985 and 1987 were seronegative for HIV-1by enzyme immunoassays (Abbott, Genetic Systems, Wellcome) and by western blot. T-lymphocyte studies in 1985 revealed a T4 cell count
report
within the normal range and
a
T4/T8
ratio of 2-3. Normal
delayed-type hypersensitivity was demonstrated in 1985 (’Multitest CMI’).
