Diagnosis of Lyme borreliosis: non-specific serological reactions with Borrelia burgdorferi sonicate antigen caused by IgG2 antibodies.

ELISA methods that measure IgG class antibodies to sonicated Borrelia burgdorferi may give false positive results. These errors could be traced to non-specific reactivity in subclass IgG2 in several instances. Sera were sampled randomly from two adult populations, which differed in having a high and low incidence of Lyme disease. If the binding of IgG2 subclass antibodies was left unrecorded in the test by the use of monoclonal reagent antibodies selective for IgG1 and IgG3, the frequency of positivity in the ELISA test decreased in samples from the low risk group. Twenty-one samples were found to be positive in an immunoblot confirmatory test. Correct prediction of positivity was obtained for 15 sera by ELISA restricted to IgG1 plus IgG3, for only four sera by ELISA restricted to IgG2 and for only six sera by IgG subclass non-restricted ELISA. A non-restricted ELISA with purified flagella of B. burgdorferi as the antigen predicted correctly 14 of the immunoblot-positive sera. The results of this ELISA correlated well with those of the IgG1 plus IgG3 subclass restricted ELISA in the high risk population (r = 0.95, prevalence of seropositivity 12%), but was significantly worse for the low risk group (r = 0.47, prevalence 2.9%). IgG subclass restriction also decreased cross-reactions of syphilitic sera in the ELISA with sonicated antigen.

Volatile hydrocarbons in pharmaceutical solutions.

Volatile pollutants such as hydrocarbons have, during many years, been analysed in small concentrations in air, water, food, pharmaceutical solutions, and human blood and tissues. It has also been shown that such substances have unexpected consequences for cell cultures and scientific experiments. These substances also accumulate in patients receiving haemodialysis and these patients are exposed to quite high concentrations. The knowledge of the toxicity of such compounds has led to the development of maximum limit concentrations with the aim to decrease the exposure of humans. This paper discusses the problems of human exposure in general and especially through pharmaceutical solutions, and the possibilities of eliminating such compounds with the aim of decreasing the exposure as a hygienic challenge.

[Volatile organic halogen compounds in food]. / Flüchtige organische Halogenverbindungen in Lebensmitteln.

Volatile halocarbons have been found in raw water, chlorinated tap water, in blood of healthy individuals and patients, in milk, urine, solutions and laboratory suspensions manufactured by the Medical Industry. Tap water is also used in the food industry and therefore it is reasonable that they also could be analysed in food.

The prevalence of antibodies against viruses causing Kumlinge and Pogosta diseases on the islands of Iniö on the southwest coast of Finland.

The prevalence of antibodies against viruses causing Kumlinge (tick-borne encephalitis) and Pogosta disease in the population of Iniö, a small island community in southwest Finland was measured. Antibodies against Kumlinge disease were found in 28% of the population, and increased from 10% in the 0-19 year age group to 42% in the 60-79 year age group. The prevalence varied markedly between different islands, being highest in the outer, bushy islands. Antibodies against Pogosta disease were detected in 2.7%.

Effect of selenium supplementation to fertilizers on the selenium status of the population in different parts of Finland.

Concentrations of selenium in the soil are very low in most regions in Finland, which explains the low selenium contents of agricultural plants and the low dietary intake of selenium. The poor selenium status of the population in Finland has been considered a possible risk to public health. In 1984, it was decided to increase the selenium intake by adding selenate to common agricultural fertilizers. In this study, the selenium concentrations of whole blood and plasma, as well as erythrocyte glutathione peroxidase activities, were measured in blood samples from four different localities in Finland, in 1984 and 1986, before and during the agricultural selenium supplementation. A low blood level of selenium in the inhabitants of central Finland was demonstrated in 1984. The selenium level of people from the south-west archipelago was a little higher, and that from the northern part of Finland considerably higher than the level in the rest of the country. By 1986, differences between these localities had almost disappeared, and most levels had increased. Plasma selenium concentrations were lower than those in whole blood samples; the concentrations showed a significant correlation. The glutathione peroxidase activities were at the same level in all four localities in 1984. By 1986, they had all increased to a slightly higher level. A weak correlation was found between erythrocyte glutathione peroxidase activity and blood selenium level.

Human twinning rate in Iniö in the south-west of Finland.

A secular demographic study on the Iniö Island in SW Finland shows an even stronger decline of twinning rates than in the Aland Islands and the rest of the archipelago. Twinning rates in Iniö declined, in fact from about 30%, to less than 10%.

Volatile halocarbons in tap water as a problem in haemodialysis therapy.

The concentrations of volatile halocarbons in the tap water of Turku and of Turku University Central Hospital are quite high and are reduced but not eliminated during water treatment at the hospital. Before haemodialysis is started, only trichloromethane is found in the blood of the patients. Two hours later dichlorobromomethane and dibromochloromethane could also be found. These substances are absorbed, and possibly accumulate, in the body or are metabolised and excreted because all their concentrations are lower at the end of dialysis therapy. Therefore, maximum levels for volatile halocarbons in drinking water should be sufficiently low to prevent these substances being detected in body fluids and special care should be taken with hospital water.

Determination of volatile halocarbons in raw and drinking water, human serum, and urine by electron capture GC.

A method for quantitative determination of volatile halocarbons in raw and drinking water, human serum, and urine is presented. Samples of water, serum, or urine were extracted in a single step with petroleum ether, and the extracts are, without further purification, analysed by high resolution gas chromatography (GC) with electron capture detection (ECD). Both external and internal calibrations were used to standardize the analytical system. External calibration is done with pure halocarbons in purified well water. Internal calibration is accomplished by spiking serum and urine samples with reference halocarbons between each of two successive extractions and GC runs. 1-iodobutane is used as internal standard, both in calibrations and actual determinations.