An investigation of the cause of the eosinophilia-myalgia syndrome associated with tryptophan use

Article Abstract:

Eosinophilia-myalgia syndrome is an illness involving abnormal blood levels of eosinophils (a type of white blood cell) and muscle pain; it can be serious and even fatal. The condition was first reported in three patients in October 1989, and was soon linked to consumption of tryptophan supplements. Tryptophan is an amino acid present in many proteins; the supplements have been used for treating depression, insomnia, and other health problems. Scientists had not previously determined whether the tryptophan itself, or some substance used in the production of the supplements, caused eosinophilia-myalgia syndrome. An investigation was conducted into the relationship between tryptophan products and eosinophilia-myalgia syndrome. The investigation included surveillance of cases of the syndrome in Minnesota, and a survey of tryptophan use in Minneapolis-St. Paul. It was found that more women than men used tryptophan products, and increasing numbers of people used the products from 1980 to 1989. For some of the study subjects, the manufacturer of the supplement was known; of these, 29 of 30 people with eosinophilia-myalgia took products manufactured by one specific company, Showa Denko K.K. There was only one case of the illness among persons who used tryptophan from other manufacturers, and it appears that in this case the product was probably mislabeled and was actually manufactured by Showa Denko K.K. Of 35 people who did not get eosinophilia-myalgia, 21 consumed supplements made by Showa Denko K.K. It was concluded based on these data and laboratory analysis of tryptophan samples that the illness was caused by an unidentified chemical constituent resulting from altered manufacturing processes of the company. There were two manufacturing changes that may have produced the unknown chemical constituent: reduced amounts of powdered carbon were used in a purification step; and a new strain of Bacillus amyloliquefaciens was utilized in a fermentation process. These two changes in procedure appeared to be linked. The unidentified chemical constituent thought to have caused the illness was probably present in tiny quantities because the tryptophan products made by Showa Denko K.K. are 99.6 percent pure tryptophan, which exceeds United States requirements. (Consumer Summary produced by Reliance Medical Information, Inc.)

Health aspects, Complications and side effects, Dietary supplements, Tryptophan, Eosinophilia-myalgia syndrome

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The epidemiology and clinical aspects of the hemolytic uremic syndrome in Minnesota

Article Abstract:

The hemolytic uremic syndrome is a condition characterized by destruction of red blood cells, decreased numbers of platelets (blood cells essential for clotting) and renal (kidney) failure. It is the main cause of renal failure among children, and some subtypes of the syndrome are associated with variants of the bacterial species Escherichia coli. One variant, E. coli O157:H7, produces a toxin capable of causing many diseases, including hemolytic uremic syndrome. Evidence exists that this disease has been increasing in recent years and, to learn more about its epidemiology in Minnesota, a retrospective review of all cases in that state between 1979 and 1988 was conducted. In addition, a case-control study (two controls per case) was carried out among patients whose illness began between January 1986 and December 1988. One hundred seventeen cases of hemolytic uremic syndrome were identified during the study period in people under 18 years of age (average age, just under 4 years). The incidence increased substantially, from 0.5 per 100,000 child-years in 1979 to 2.0 per 100,000 child-years in 1988. In children younger than 5, the incidence went from 1.6 to 5.8 cases per 100,000 child-years. Most cases occurred between June and October. Patients' symptoms are described. Almost half the patients required dialysis, and the majority (89 percent) received transfusions of red blood cells, platelets, or plasma. Four deaths occurred. E. coli O157:H7 was identified in the stools of 13 of 28 patients (46 percent) who submitted such specimens. In the case-control study, it was found that patients ('cases') were more likely to attend day-care centers than controls. Children whose disease became most severe were those with high numbers of one type of white blood cell (polymorphonuclear leukocytes), a shorter initial phase of the disease, or bloody diarrhea. The disease appears to be increasing in Minnesota and may be transmitted in day-care centers, perhaps via contaminated hamburger. It constitutes an important public health problem and occurrences should be reported in more states than Minnesota and Washington (as is the case now). (Consumer Summary produced by Reliance Medical Information, Inc.)

Diagnosis, Pediatric diseases, Children, Demographic aspects, Diseases, Minnesota, Hemolytic-uremic syndrome

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Absence of HIV infection in blood donors with indeterminate Western blot tests for antibody to HIV-1

Article Abstract:

In the presence of a virus, the B cells of the body's natural defense system, the immune system, produce a protein called an antibody that specifically binds to and inactivates that virus. Blood from volunteer donors is commonly screened for antibody to the human immunodeficiency virus type 1 (HIV-1) in order to determine whether the individual had been previously exposed to the HIV virus. The Western blot assay, used to verify the presence of the HIV-1 antibody, reveals six to nine characteristic bands if antibody to HIV-1 is present. Although blood samples will often produce one or two bands, a positive test for HIV-1 antibody requires the demonstration of only certain types of bands; otherwise the test result is considered indeterminate, meaning that it is not positive or negative. Various tests were performed to determine whether HIV-1 or HIV-2 was present in the blood from 99 volunteer blood donors, who tested positive for the HIV-1 antibody on the enzyme immunoassay test and indeterminate in the Western blot assay. Of the 99 blood donors, 98 reported no risk factors for HIV-1 infection, and one donor had used intravenous drugs. After 14 months, 65 donors were still reactive for HIV-1 antibody. The Western blot results were still indeterminate in 91 cases and negative in eight cases. There was no evidence of HIV-1 or HIV-2 infection in the 99 donors. Thus, persons at low risk for HIV infection with persistent indeterminate HIV-1 Western blot are not infected with HIV-1 or HIV-2. (Consumer Summary produced by Reliance Medical Information, Inc.)

Evaluation, Testing, Blood donors, Blood donation, HIV antibodies, Immunoenzyme technique, Immunoenzyme techniques, Western immunoblotting, Western blot

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