Application of a Mycoplasma group-specific PCR for monitoring decontamination of Mycoplasma-infected Chlamydia sp. strains.

Mycoplasma contamination of biological materials remains a major problem. Most contaminations are caused by the use of Mycoplasma-contaminated cell lines. We adapted a Mycoplasma group-specific PCR to detect Mycoplasma contamination in cell lines and demonstrate its use in monitoring decontamination procedures with Mycoplasma-contaminated suspensions of Chlamydia spp.

A calibrator for the determination of the erythrocyte concentration in electronic blood cell counting.

A stable calibrator, suitable for the quality control of electronic counting of erythrocytes, has been developed. The assigned concentration is determined by the cooperation of six laboratories using various types of blood cell counting instruments. The performance of the instruments was checked prior to operation.

Phosphatidylinositol-specific phospholipase C activity as a marker to distinguish between pathogenic and nonpathogenic Listeria species.

In this study, 468 Listeria strains were checked for the presence of phosphatidylinositol-specific phospholipase C (PI-PLC) activity by using a simple assay that consisted of overlaying colonies formed on agar plates with L-alpha-phosphatidylinositol as substrate. In this assay, PI-PLC-active colonies show turbid halos around the colonies as a result of the release of insoluble diacylglycerol from the substrate. This activity was detected only in the pathogenic species Listeria monocytogenes and was not present in any of the 167 strains of Listeria seeligeri, Listeria welshimeri, Listeria innocua, Listeria murrayi, and Listeria grayi tested.

Relative inhibition of rat plasma and erythrocyte cholinesterases by pesticide combinations.

A selected combination of carbamate pesticides (carbofuran, oxamyl and propoxur were examined for cholinesterase (ChE) inhibition. The enzyme source was rat plasma and erythrocytes. Enzyme activity was determined colorimetrically using the Ellman technique adapted for erythrocyte ChE activity.

Salmonella contamination of poultry flocks in The Netherlands.

The contamination of poultry in the Netherlands with Salmonella enteritidis was tested. For this, different methods (detection of S. enteritidis in faecal samples of 25 g; detection of S.

Non-target and environmental hazards of pesticides.

When compared with pesticide pollution from other sources and pollution by other agents, the hazards of atmospheric pollution by pesticides appear relatively insignificant. The high persistency in the environment observed especially with the organochlorines suggests that there could be a gradual accumulation of residual pesticides in the atmosphere. Thus, in addition to the function of redistributing pesticides by air currents and aerial drifts, the atmosphere may become a major reservoir for drift prone finely divided particulate pesticides and highly volatile compounds.

Evaluation and interpretation of data obtained with immunoassays and DNA-DNA hybridization techniques.

During the last decade several new analytical techniques have been developed for testing food products and clinical samples. One technique uses sensitive immunoassays such as enzyme-linked immunosorbent assay (ELISA) and latex agglutination. The most important step in developing sensitive immunoassays is the evaluation of the assay for specificity, cross-reactivity and sensitivity.

Reductive dehalogenation of dichloroanilines by anaerobic microorganisms in fresh and dichlorophenol-acclimated pond sediment.

We investigated the transformation of 2,4-dichloroaniline (2,4-DiCA) and 3,4-DiCA to monochloroanilines (CA) in anaerobic pond sediment. Dechlorination of 3,4-DiCA to 3-CA started after a lag period of 3 weeks and was complete after an additional 5 weeks. Although 2,4-DiCA disappeared over 8 weeks, the appearance of a CA product could not be detected.

Overproduction and purification of Treponema pallidum recombinant-DNA-derived proteins TmpA and TmpB and their potential use in serodiagnosis of syphilis.

We report the construction of expression plasmids carrying two Treponema pallidum genes encoding for the 42-kilodalton membrane protein TmpA (treponemal membrane protein A) and the 34-kilodalton membrane protein TmpB. Using the leftward promoter of bacteriophage lambda, which is controlled by a thermosensitive repressor, we obtained a high level of heat-inducible synthesis of TmpA and TmpB in Escherichia coli K-12. Both proteins were purified to near homogeneity, and the presence of antibodies to TmpA and TmpB in human sera was determined by an enzyme-linked immunosorbent assay.

Subacute toxicity of Zwittergent administered intramuscularly.

In order to assess the systemic toxicity of Zwittergent 3-14, a detergent used in the protein-detergent complex vaccines for its attractive immunogenic properties, a subacute toxicity study was performed. In this 4-week toxicity experiment five female and five male rats per group were injected intramuscularly with 0.25 ml of 0, 75, 750 and 7500 micrograms Zwittergent ml-1 sterile saline solution.

An in vitro evaluation of the potential toxicities and interactions of carbamate pesticides.

The inhibition of rat plasma cholinesterase was used to screen the toxicity of carbamate pesticides in vitro. All three carbamates studied-aldicarb, carbofuran and oxamyl-inhibited the rat cholinesterase in a dose-dependent manner, as determined by the Ellman technique. The concentrations that produced 25 and 50% inhibition of cholinesterase (IC(25) and IC(50)) were, respectively, 1 x 10(-8) and 5 x 10(-7)m for aldicarb, 1 x 10(-9) and 1.

Pharmacological interaction and combined toxicity of exposure to environmental chemicals.

Environmental chemicals are capable of interaction with each other and with endogenous substances to minimize or augment their individual toxicities. Interaction between chemicals could take place via the absorption, distribution and excretory routes. Induction and inhibition of the hepatic drug metabolising enzymes also play a significant role in chemical activation, detoxification and interactions.

Treponema pallidum subspecies pallidum (Nichols) and Treponema pallidum subspecies pertenue (CDC 2575) differ in at least one nucleotide: comparison of two homologous antigens.

In an attempt to identify antigenic differences between Treponema pallidum subsp. pallidum (T. pallidum) and Treponema pallidum subsp.

Screening for thalassaemia using the width of the Technicon H6000/H601 erythrocyte size histograms.

The red cell distribution width (RDW) calculated from the data of an erythrocyte size distribution (ESD) histogram generated by a Technicon H6000/H601 blood cell analyser was shown to be not suitable for distinguishing iron deficiency from thalassaemia trait and other microcytic conditions. The absolute distribution width at half maximum (ADW0.5) of these ESD histograms can be used efficiently for screening on thalassaemia trait.

Serological evidence for Encephalitozoon cuniculi infection (nosemiasis) in gnotobiotic guineapigs.

Encephalitozoon cuniculi infection (nosemiasis) was serologically diagnosed in hysterectomy-derived gnotobiotically reared guineapigs. The probability of vertical transplacental transmission is discussed.

Aflatoxin M1 in whole milk-powder reference materials.

The development of three full cream milk powder reference materials, certified for their aflatoxin M1 content, is briefly described. The materials were prepared and certified within the Reference Material Programme of the Community Bureau of Reference. The three reference materials RM's 282, 284 and 285 contain aflatoxin M1 at concentrations of: less than 0.

Aspartame: review of recent experimental and observational data.

In this report the neurotoxicity of aspartame and its constituent amino acids aspartic acid and phenylalanine is reviewed. The adverse reactions ascribed to the consumption of aspartame-containing products, as reported in the U.S.

Toxicity and bioaccumulation of chlorophenols in earthworms, in relation to bioavailability in soil.

The acute toxicity of five chlorophenols for two earthworm species was determined in two sandy soils differing in organic matter content and the results were compared with adsorption data. Adsorption increased with increasing organic matter content of the soils, but for tetra- and pentachlorophenol was also influenced by soil pH. Earthworm toxicity was significantly higher in the soil with a low level of organic matter.

Toxicokinetic aspects of thallium poisoning. Methods of treatment by toxin elimination.

The elimination techniques which are used in the treatment of thallium poisoning are evaluated in toxicokinetic perspective. Prussian Blue therapy and forced diuresis are effective in the treatment of acute as well as subacute thallium intoxications. Both elimination techniques can be applied without danger from neurological side effects.

Use of recombinant antigens expressed in Escherichia coli K-12 to map B-cell and T-cell epitopes on the immunodominant 65-kilodalton protein of Mycobacterium bovis BCG.

In gene libraries of Mycobacterium bovis BCG, Mycobacterium tuberculosis, and Mycobacterium leprae, recombinants were frequently encountered that expressed an immunodominant 65-kilodalton (kDa) protein antigen that was shown to react with a high proportion of mycobacterium-reactive human and murine T cells and murine monoclonal antibodies. In this study, recombinant antigens were used to map T-cell and B-cell epitopes on the M. bovis BCG 65-kDa protein that was previously designated MbaA.

Acute MCPP intoxication: report of two cases.

1. Two cases of serious intoxication with phenoxy herbicides (MCPP) are reported. 2.

Incidence of Foodborne Diseases in The Netherlands: Annual Summary 1982 and an Overview from 1979 to 1982.

Data on the incidence of foodborne disease in 1982 are presented. A total of 319 incidents affecting 1376 ill persons was analyzed. In 86 incidents (553 cases), the etiology was established.