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H van Beek

Publications and source records attributed to H van Beek.

At least 19 recordsLinked to original sources
PubMed1992

Increased metallothionein in the liver and kidney of patients with amyotrophic lateral sclerosis.

To evaluate the putative role of metals and trace elements in the pathogenesis of classic amyotrophic lateral sclerosis, we studied the metallothionein levels in liver and kidney samples obtained at autopsy from 24 patients with amyotrophic lateral sclerosis and 18 controls. To assay metallothioneins and copper, cadmium, and zinc bound to metallothioneins, we used high-performance liquid chromatography directly coupled to flame atomic absorption spectrometry. Total cadmium, zinc, and copper concentrations were determined separately with the use of graphite furnace atomic absorption spectrometry with Zeeman background correction. The median liver metallothionein level was 60.3 mg/kg (range, 9 to 318 mg/kg) in the patients with amyotrophic lateral sclerosis and 12.6 mg/kg (range, 0 to 104.5 mg/kg) in the controls. In the kidney, median metallothionein levels were 126.9 mg/kg (range, 44 to 387 mg/kg) in the patients with amyotrophic lateral sclerosis and 64 mg/kg (range, 13.1 to 187 mg/kg) in the controls. Total zinc, cadmium, and copper concentrations, as measured by atomic absorption spectrometry, were not significantly different in patients vs controls. Our finding of elevated metallothionein levels in organs from patients with amyotrophic lateral sclerosis may indicate an increased exposure to metals.

Adolescent↗
PubMed1991

[The impacted upper cuspid].

Impacted upper cuspids may give rise to problems, such as the formation of cysts and the resorption of adjacent teeth. Early diagnosis (before the age of 12) is important. Proper timing of extraction of the deciduous cuspid may lead to spontaneous correction. When the position of the cuspid is unclear, orthopantomography and a lateral skull film may be helpful. Palatally impacted cuspids should be exposed surgically and moved into position by orthodontic treatment. Labially impacted cuspids are exposed by relocation of an attached gingival flap. The experience of the authors with the treatment of 81 patients are reported.

Adolescent↗
PubMed1990

[Lead poisoning in cattle in north Netherlands. October 1989-January 1990].

By the end of 1989 a serious lead intoxication of cattle occurred in the northern part of the Netherlands (provinces Groningen and Friesland). This intoxication appeared to be caused by contaminated feed. Over 300 farms were stricken, with about 15,500 animals (mostly dairy cattle). In a period of one to four weeks these animals consumed about 1,000 kg of lead. This resulted in lead levels in milk, livers, and kidneys above the regulatory safety limits. Thanks to the chelating therapy that was rapidly applied by the local veterinarians, only about 30 animals died of an acute lead intoxication. The cooperating governmental and private authorities took action to prevent exposure of consumers to lead-contaminated animal products. Based on careful estimations, predictions were made of the lead levels to be expected in animals products and the time needed for depletion of these levels. The appropriate animals were marked to ensure their identification, and the decline in time of the lead levels in milk and offals was conscientiously monitored. In the second week of 1990 the lead concentrations were decreased to levels well below the regulatory limits, and hence the marks were removed from the animals.

Animal Feed↗
PubMed1988

[A case of selenium poisoning in piglets].

Acute paralysis was observed in suckling piglets and weaner piglets on a pig breeding farm. Pathomorphological investigations revealed characteristic lesions in the central nervous system. These lesions were indicative of selenium poisoning. This was verified by chemical-toxicological analysis of organs and tissues of the affected pigs. Poisoning was shown to have been caused by the feed: one feed preparation contained an extremely large amount of selenium, which was due to human failure.

Animal Feed↗
PubMed1988

Environmental contamination by heavy metals and fluoride in the Saeftinge salt marsh (The Netherlands) and its effect on sheep.

The Saeftinge salt marsh in the Westerschelde estuary (southwestern part of the Netherlands) represents one of the very few tidal brackish marsh ecosystems in Western Europe. From May 1983 to May 1985 the local pollution of this marsh with metals and fluoride was investigated. Samples from soil and vegetation were analysed monthly for cadmium, lead, copper, zinc, manganese, iron, and fluoride. The amount of these substances in the soil appeared to be related to both the percentage of clay particles and organic matter in the soil and to the frequency of tidal submergences. In vegetation, the pollutants clearly showed a seasonal variation. Adherent clay, deposited on the plants during submergences, contributed considerably to the total amount of these elements. Sheep grazing in the marsh were investigated for renal and faecal excretion of these elements, but no relation between these samples and the seasonal variation in vegetation was found. Presumably sheep consumed vegetation selectively, avoiding the more contaminated plants. Regular clinical inspections of the sheep revealed no signs of acute or chronic intoxication. The organs of sheep that died during the investigation showed increased levels of cadmium in the liver and kidney, and iron in the liver, but not enough to cause alarm. Fluoride found in the rib material, although slightly increased, did not indicate fluorosis. In conclusion, contamination with metals and fluoride, as observed in the salt marsh, apparently does not impair the health of locally grazing sheep. This may be due to selective consumption behaviour of the sheep, their stabling during the winter, limited biological availability of the elements studied, and a sheep management adapted to the local circumstances.

Animals↗
PubMed1986

Metal pollution in a salt marsh and its effect on sheep.

In a salt marsh in the Westerschelde, samples were taken from soil and vegetation during 15 months. Concentrations of Cd, Pb, Cu, Zn, Mn, and Fe were measured and compared with levels of these metals in livers, kidneys, and faeces of sheep grazing there. The contamination extent of soil ranges from 2 (Cu) to 8 (Cd); in spring some plants exceed the advised maximum tolerable level of dietary Cd for sheep. However, levels of metals in organs from sheep do not indicate intoxication, nor did clinical inspections and autopsies. It is suggested that sheep exhibit a selective consumption behaviour and that the bioavailability of the metals in this marsh is low.

Animals↗