Repeated hand urticaria due to contact with fishfood.
(17/2329)
BACKGROUND: The etiology of urticaria is often difficult to determine. However, in case of repeated circumstance-connected urticaria, the reason may be easily clarifyable. CASE: A 51-year-old healthy woman repeatedly experienced occupational hand urticaria when handling fish food. An unexpected reason for the urticaria was found in that the fishfood contained histamine as a "contaminant". CONCLUSIONS: In fishfood batches, biological degradation can produce histamine and possibly other toxic substances that can lead to occupational health problems. (+info)
Exposure to exogenous estrogens in food: possible impact on human development and health.
(18/2329)
There has been increasing concern about the impact of environmental compounds with hormone-like action on human development and reproductive health over the past decades. An alternative but neglected source of hormone action that may be considered in this connection is hormone residues in meat from husbandry animals treated with sex steroid hormones for growth promotion. Treatment of cattle with naturally occurring or synthetic sex hormones may enhance lean muscle growth and improve feed efficiency and is therefore a very cost effective procedure for cattle producers who have used it for decades in some Western countries, including the USA and Canada. The Joint Food and Agricultural Organisation/World Health Organisation (FAO/WHO) expert committee on food additives (JECFA) and the US Food and Drug Administration (FDA) considered, in 1988, that the residues found in meat from treated animals were safe for the consumers. We have re-evaluated the JECFA conclusions regarding the safety of estradiol residues in meat in the light of recent scientific data, with special emphasis on estradiol levels in prepubertal children. These levels are needed for estimates of the normal daily production rates of estradiol in children, who may be particularly sensitive to low levels of estradiol. In our opinion, the conclusions by JECFA concerning the safety of hormone residues in meat seem to be based on uncertain assumptions and inadequate scientific data. Our concerns can be summarized as follows. 1) The data on residue levels in meat were based on studies performed in the 1970's and 1980's using radioimmunoassay (RIA) methods available at the time. The sensitivity of the methods was generally inadequate to measure precisely the low levels found in animal tissues, and considerable variation between different RIA methods for measuring steroids exists. Therefore the reported residue levels may be subject to considerable uncertainty. 2) Only limited information on the levels of the various metabolites of the steroids was given despite the fact that metabolites also may have biological activity. 3) Reliable data on daily production rates of steroid hormones were and are still lacking in healthy prepubertal children. This lack is crucial as previous guidelines regarding acceptable levels of steroid residues in edible animal tissues have been based on very questionable estimates of production rates in children. Thus, even today the US FDA bases its guidelines on the presumably highly overestimated production rates in prepubertal children given in the JECFA 1988 report. 4) The possible biological significance of very low levels of estradiol is neglected. In conclusion, based on our current knowledge possible adverse effects on human health by consumption of meat from hormone-treated animals cannot be excluded. (+info)
Measurement of cadmium-induced metallothionein in urine by ELISA and prevention of overestimation due to polymerization.
(19/2329)
Urinary metallothionein (MT) is a biological marker of cadmium (Cd) exposure and Cd-induced renal dysfunction. The MT is prone to oxidation due to high cysteine content and forms polymers, which can result in overestimation of the protein by immunochemical methods. The objectives of the present study were to develop an enzyme-linked immunosorbent assay (ELISA) for the measurement of MT in urine and to find ways by which the protein could either be preserved in its monomeric form or converted to this form before analysis to avoid overestimation. Urine specimens analyzed were either from rats repeatedly injected with Cd or from individuals chronically exposed to cadmium through their diets. The MT in rat urine remained in the monomeric form if the urine was collected at 4 degrees C but did not if it was collected at room temperature. The MT was also polymerized if the urine was subjected to repeated freezing and thawing. Overestimation of MT in rat urine occurred (as much as 12-fold) if the MT was polymerized. Addition of 5mM mercaptoethanol to freshly collected rat urine retarded MT polymerization, and addition of 50mM mercaptoethanol converted the polymerized MT to its monomeric form. Analysis of MT in frozen human urine samples revealed that if the urines were not treated with mercaptoethanol, the estimates of MT concentration were up to 11-fold higher than in the treated samples. We conclude that the polymerization of MT in rat and human urines is a serious problem and results in overestimation of the protein by ELISA and that this problem could be overcome by the addition of mercaptoethanol to the urine samples prior to analysis. (+info)
Selenium elimination in pigs after an outbreak of selenium toxicosis.
(20/2329)
In May 1996, 150 grower pigs in 5 California counties were exposed to selenium-contaminated feed distributed by a single feed company. Feed samples from 20 herds had a mean selenium concentration of 121.7 ppm dry weight (range, 22.1-531 ppm). In San Luis Obispo County, 52 pigs in 24 herds were exposed to the feed, and 8 pigs died with signs of paralysis. Bilateral symmetrical poliomyelomalacia involving the ventral horns of the cervical and lumbar intumescence was evident on histologic examination of spinal cord from affected pigs. Of 44 surviving exposed pigs, 33 (75%) exhibited signs of selenosis, including anorexia, alopecia, and hoof lesions. Thirty-nine of 44 pigs (88.6%) had elevated (>1 ppm) blood selenium concentrations. Surviving exposed pigs were changed to a standard commercial ration containing approximately 0.5 ppm (dry weight) selenium. Blood selenium concentrations were determined weekly for 46 days following removal of the contaminated feed and were compared with values of 20 control pigs fed a standard commercial ration. Mean (+/-SD) blood selenium concentrations of exposed pigs were 3.2 +/- 2.6 ppm at the initial sampling and 0.4 +/- 0.1 ppm after 46 days. Mean blood selenium concentrations of < or = 0.3 ppm for control pigs at all samplings were significantly lower (P < 0.001) than concentrations for exposed pigs. Muscle and liver samples of 22 of the 44 exposed pigs were collected at slaughter approximately 72 days after withdrawal of the selenium-contaminated feed. Muscle samples had a mean selenium concentration of 0.36 ppm (wet weight). Liver samples had a mean selenium concentration of 1.26 ppm (wet weight). One liver sample had a selenium value in the toxic range for pigs (3.3 ppm wet weight; reference range, 0.4-1.2 ppm). A 1-compartment pharmacokinetic model of selenium elimination in exposed pigs was generated, and the geometric mean blood selenium elimination half-life was estimated to be 12 days. The 60-day withdrawal time recommended by the Food Animal Residue Avoidance Database was considered sufficient to allow safe human consumption of tissues from exposed pigs. (+info)
Gene sequence and properties of an s-triazine ring-cleavage enzyme from Pseudomonas sp. strain NRRLB-12227.
(21/2329)
Pesticides based on the s-triazine ring structure are widely used in cultivation of food crops. Cleavage of the s-triazine ring is an important step in the mineralization of s-triazine compounds and hence in their complete removal from the environment. Cyanuric acid amidohydrolase cleaves cyanuric acid (2,4,6-trihydroxy-s-triazine), which yields carbon dioxide and biuret; the biuret is subject to further metabolism, which yields CO(2) and ammonia. The trzD gene encoding cyanuric acid amidohydrolase was cloned into pMMB277 from Pseudomonas sp. strain NRRLB-12227, a strain that is capable of utilizing s-triazines as nitrogen sources. Hydrolysis of cyanuric acid was detected in crude extracts of Escherichia coli containing the cloned gene by monitoring the disappearance of cyanuric acid and the appearance of biuret by high-performance liquid chromatography (HPLC). DEAE and hydrophobic interaction HPLC were used to purify cyanuric acid amidohydrolase to homogeneity, and a spectrophotometric assay for the purified enzyme was developed. The purified enzyme had an apparent K(m) of 0.05 mM for cyanuric acid at pH 8.0. The enzyme did not cleave any other s-triazine or hydroxypyrimidine compound, although barbituric acid (2,4, 6-trihydroxypyrimidine) was found to be a strong competitive inhibitor. Neither the nucleotide sequence of trzD nor the amino acid sequence of the gene product exhibited a significant level of similarity to any known gene or protein. (+info)
From November 1998 through January 1999, 52 cases of trichinellosis were identified by the public health surveillance systems in 11 cities and districts of the state of Northrhine-Westfalia (NRW), Germany. In comparison, zero to 10 cases were reported annually in Germany during 1987-1997. This report summarizes the investigation of these cases, which indicated the existence of two simultaneous outbreaks-one caused by contaminated ground meat and the other by a commercially prepared raw smoked sausage. (+info)
High-resolution gas chromatographic profiles of volatile organic compounds produced by microorganisms at refrigerated temperatures.
(23/2329)
Three different strains of bacteria isolated from spoiled, uncooked chicken were grown in pure culture on Trypticase soy agar supplemented with yeast extract. The volatile organic compounds produced by each culture were concentrated on a porous polymer precolumn and analyzed by high-resolution gas chromatographic mass spectrometry. Twenty different compounds were identified. Both qualitative and quantitative differences in the chromatographic profiles from each culture were found. (+info)
Antimicrobial activity of Monascus pilosus IFO 4520 against contaminant of Koji.
(24/2329)
Antimicrobial activity of Monascus pilosus IFO 4520 was examined to prevent contamination during beni-koji making in the open air. The antibacterial effect of the beni-koji prepared with this strain occured with 30 mg/ml of beni-koji extract in combination with 0.5% lactic acid against two contaminants of koji, Micrococcus varians and Bacillus subtilis. There were two compounds, antibacterial and antiyeast substances, in the beni-koji extract. These results suggest a possibility of inhibiting the growths of contaminants during beni-koji making using beni-koji extract and lactic acid. (+info)