PubMed Health⌕ Search

Biomedical subjects

I de Vries

Publications and source records attributed to I de Vries.

At least 19 recordsLinked to original sources
PubMed2005

[Measures to reduce absorption in the treatment of intoxications].

New guidelines on gastrointestinal decontamination in overdose situations have been published. In cases of serious and potentially life-threatening intoxication, gastric lavage can be performed up to 1 hour after ingestion. It should not be considered as routine treatment. If a patient has ingested a potentially toxic amount of a poison which is known to be absorbed by charcoal, single-dose activated charcoal in powder form may be considered up to 1 hour after ingestion. After ingestion of a potentially lethal amount of a toxin that is travelling through the enterohepatic or entero-enteral circulation, multiple-dose activated charcoal can be considered. The efficacy of carbamazepine, theophylline, quinine, dapsone and phenobarbital has been proven. In the treatment of potentially life-threatening intoxications with sustained-release preparations or drug-filled packages, particularly after ingestion of substances that do not bind to activated charcoal, whole bowel irrigation can be considered. Only ifdefaecation is insufficient should administration of a laxative together with activated charcoal be considered.

Cathartics↗
PubMed2005

[Toxicity of dioxins in humans].

Dioxins are produced as pollutants in industrial production processes and during incineration (e.g. of waste). Thanks to their highly lipophilic nature and long half-life in fat tissue, they accumulate in the food chain. One of the most important initial steps in the toxicity of dioxins is the activation of a cytosol receptor. This induces the production of a number of proteins, including cytochrome P450 CYP1A1. Our knowledge about the effects of dioxins in humans is based primarily on long-term epidemiological studies of people who were exposed to high concentrations of dioxins, either occupationally or as the result of an accident. The best known and most definitely established effect of exposure to dioxins is chloracne. Whether there is a relation between exposure to dioxins and other diseases, such as cancer, is uncertain.

Animals↗
PubMed2003

[Health risks raised by ephedra in food supplements].

In recent years, the use of herbal preparations containing Ephedra has increased and so has the number of reported negative health effects. Ephedra products are used as a slimming aid, (sports) performance enhancer, stimulant during long working hours and as a plant-based ecstasy-surrogate in the party scene. The health effects caused by the use of Ephedra products are mainly restlessness, agitation, tachycardia and palpitations. The most important risk factors are the relatively high amounts of Ephedra alkaloids in the preparations available, the varying concentrations within different batches of the same product, the relatively high risk of voluntary overdosing in order to improve results and the occurrence of interactions with the concurrent use of other stimulants and medicines.

Dietary Supplements↗
PubMed2002

[An epidemic of epileptic seizures after consumption of herbal tea].

UNLABELLED: At the end of September 2001 the Inspectorate for Health Protection and Veterinary Public Health and the National Poisons Control Centre (NPCC) were informed about adverse health effects after consumption of a herbal tea. During consultations it was suggested that Japanese star anise (Illicium anisatum L.), which is known to contain a neurotoxin, may have been inadvertently mixed into the herbal tea. In view of the severity of the adverse health effects and the clear association with consumption of a specific herbal tea, the supplier was urgently advised to withdraw the suspected herbal tea from the market. A total of 63 persons reported symptoms of general malaise, nausea and vomiting 2-4 hours following consumption of the herbal tea. Twenty-two persons required hospitalisation, of whom 16 due to generalised tonic-clonic seizures. Medical investigations revealed no underlying pathology and after supportive treatment, the patients were discharged in good health. Morphologic and organoleptic investigations of the suspected herbal tea indicated that this possibly contained Japanese star anise. NMR analysis of the herbal tea confirmed the presence of the neurotoxin anisatin, a non-competitive GABA-antagonist which can cause hyperactivity of the central nervous system and tonic-clonic seizures. CONCLUSION: Ingestion of a herbal tea containing anisatin caused the reported serious adverse health effects. Close cooperation between clinicians, the Inspectorate for Health Protection and Veterinary Public Health and the NPCC played a vital role in preventing further harm to public health.

Adult↗
PubMed2001

Clinical evaluation of nine hollow-fibre membrane oxygenators.

In a comparative study we investigated the performance characteristics of nine hollow-fibre oxygenators. In a clinical setting, 10 units of each type of oxygenator were tested for oxygen exchange, transoxygenator pressure drop, heat exchanger performance and blood trauma. The oxygenators included are Maxima PRF Plus, Affinity, Forte, Affinity NT, Quantum, Optima, Capiox 1.8, Hilite and Quadrox. Ninety patients scheduled for elective coronary bypass surgery were enrolled in the study. Cardiotomy suction blood was not allowed to mix with the circulating blood. Samples were taken preoperatively (t1), immediately after cooling and crossclamping of the aorta (t2), during rewarming (t3), and postoperatively (t4). The results showed that under clinical conditions all of the tested oxygenators are well capable of meeting the normal and above-normal oxygen needs. The Quantum and Affinity NT are the best performing oxygenators with respect to oxygen transfer. The Quantum oxygenator with a small membrane surface area of 1.9 m2 has also the highest oxygen transfer per square metre. A direct relationship between shunt fraction and blood flow could not be established in all oxygenators. The lowest shunt fraction at 4 litres blood flow was seen in the Maxima, Quantum and Affinity NT groups (15%). At near physiological PaO2-values, we noticed a negative influence on the shunt fraction. Large differences exist in pressure drop between the oxygenators under standardized conditions with circulating priming, as well as during bypass. The lowest pressure drop was noticed in the Quadrox and Affinity NT, the highest in the Quantum, Capiox and Optima. However, we did not measure any differences in pressure drop after cooling and during re-warming. Differences exist between the heat exchanger performances. The Quadrox oxygenator is the most efficient, while the Maxima has the smallest performance factor. It was not possible to calculate heat exchanger performance for the Hilite due to incorrect temperature measurement. The high pressure gradients in some of the devices did not result in higher haemolysis. Plasma free haemoglobin values were low in each oxygenator. There are no differences in platelet drop postoperatively. The influence on blood trauma of the higher pressure drop in some of the tested devices, in combination with the higher centrifugal pump revolutions needed to overcome this gradient, has to be studied with longer perfusion times.

Blood Gas Analysis↗
PubMed1999

[Risks of ingesting cleansing tablets for dental prostheses].

Aim of the study was to determine the frequency and severity of intoxication caused by cleansing tablets for dental prostheses. The investigation was performed by the National Poisons Controle Centre in Bilthoven, the Netherlands. In 1996, alle 78 physicians who requested information from the Centre about intoxications with cleansing tablets for dental prostheses were sent a questionnaire enquiring about the exposure situations and the severity of the effects of the intoxications. Forty-six questionnaires (59%) were returned. Older people (24: 52%) and children (14; 30%) constituted the largest groups of intoxicated. As a rule, accidental ingestion of the tablets was involved. In most cases, one tablet had been swallowed. Local effects, mostly of a mild nature, were reported in 22 patients. Systemic effects were reported in two patients but in these cases the connection with the ingestion was doubtful.

Accidents, Home↗
PubMed1998

Healthy volunteer studies in toxicology.

In the future there will be an increasing need for quantitative human risk assessment in order to develop soundly-based risk level regulations. Human volunteer studies can contribute to gain essential data needed for this risk assessment. Volunteer studies are especially relevant to study the biokinetics and metabolism of a compound. Comparison of these data with those of laboratory animals can increase the accuracy in extrapolation study results from animals to man. Furthermore, the results of volunteer studies can be used to fill in the gaps of knowledge which cannot be solved with in vitro or animal studies in order to develop adequate physiologically-based biokinetic or biodynamic models for human risk assessment.

Animals↗
PubMed1998

[Acute management of patients bitten by poisonous snakes].

The management of poisonous snake bites includes first aid and clinical medical treatment. First aid consists of reassurement of the patient, immobilisation of the bitten limb and rapid transport to the nearest hospital to monitor the vital functions. In no case suction, incision or tight bandages should be applied. The degree of envenomation can be classified in three categories depending on the spread of the symptoms: no symptoms, only local non-progressive symptoms, and systemic or local rapidly progressive symptoms (severe envenomation). Antivenin therapy is indicated in severe envenomation. Because of the risk of anaphylactic reactions or serum sickness, antivenin should be given with great caution. Antibiotic therapy and tetanus prophylaxis are advised in all cases. Immediate consultation with the National Intoxication Centre of the Rijksinstitut voor Volksgezondheid en Milieu (RIVM) is always warranted; telephone: 030-2748888. In a national protocol, which is available at the RIVM, the Harbour Hospital Rotterdam, the Academic Medical Centre and Artis Zoo Amsterdam, the correct management of snake bites is described. An overview of all antivenins available in the Netherlands is also given in this protocol.

Anaphylaxis↗
PubMed1998

Lead toxicokinetics. Development of a biokinetic model to understand and predict the outcome of treatment.

Quite often physicians contact the Dutch Poisons Control Centre for information on patients with increased lead exposure. The most important questions raised by physicians dealing with these patients are how to estimate the lead exposure and the total lead body burden, how to interpret blood lead concentrations and whether the patient needs treatment. In order to answer these questions we need knowledge of the toxicokinetics of lead in the human body. To achieve insight and to make this knowledge accessible to physicians a biokinetic model for lead metabolism in the human body was developed. A four-compartment model with first-order kinetics, based on the concept of Kneip, was used. A biokinetic model uses a mathematical approach to translate the complex biological and kinetic behaviour of lead. In order to develop this biokinetic model two computer programmes were used. At the moment the model is tested with clinical data from patient treated at the medical toxicology outpatient clinic of the Utrecht University Hospital (this department cooperates very closely with the National Poisons Control Centre). Especially with regard to chelation therapy for elevated blood lead levels due to chronic exposure, the model is very helpful in visualising the toxicokinetics of lead in the human body. Toxicokinetic model might help improve knowledge of lead toxicokinetics, leading to well-considered guidelines for treatment of lead intoxications.

Absorption↗
PubMed1997

[A painful encounter with the weever (Echiichtis vipera)].

The National Poisons Information Centre of the National Institute of Public Health and the Environment in the Netherlands in the past 2 years received dozens of requests for information about intoxication due to stings of the weever, Echiichtis vipera. The venomous apparatus of the weever consists of gill cover spines and 5 to 8 dorsal fin spines. The fish buries itself in the sandy or muddy bottom of the sea to wait for prey. The mixture of toxins that enters the skin upon contact with the spines causes a heavy local reaction, characterized mostly by pain, which untreated persists for 24 hours. An erythematous oedema may develop locally, spread over the entire extremity and persist for days. Systemic reactions are rare. Since the toxin mixture is heat labile, treatment is essentially simple: clean the wound and immerse the affected limb as soon as possible in warm water (45 degrees C) for 30 to 90 minutes. This makes the pain disappear.

Animals↗
PubMed1997

Intermittent antegrade/selective cerebral perfusion during circulatory arrest for repair of the aortic arch.

If the aortic arch requires repair or replacement due to an aneurysm or dissection, conventional cardiopulmonary bypass (CPB) is not possible during the period in which the aortic arch is excluded from the circulation. This creates a situation in which there is no cerebral circulation. The brain needs adequate protection from this ischaemic insult. Hypothermic circulatory arrest (HCA), antegrade/selective cerebral perfusion (ASCP) and retrograde cerebral perfusion (RCP) are reported to exhibit their cerebral protective capabilities during procedures involving the aortic arch. HCA can provide adequate protection in procedures of short duration and avoids the complications associated with cerebral perfusion techniques. The main disadvantage of HCA is that the 'safe' duration of circulatory arrest is not clearly defined. Topical cooling of the head may enhance cerebral hypothermia and provide additional protection. If longer periods of circulatory arrest are anticipated or occur unexpectedly, we suggest that ASCP can offer improved cerebral protection by providing adequate brain perfusion and improved cerebral cooling. By using a coronary sinus perfusion catheter as a carotid artery cannula, it is not necessary to snare or clamp the carotid arteries. This technique minimizes the chance of damaging the carotid arteries. In this report, we describe our set-up and ASCP perfusion protocol for the surgical repair of an aortic arch aneurysm.

Aortic Aneurysm, Thoracic↗
PubMed1997

Acute work-related poisoning by pesticides in The Netherlands; a one year follow-up study.

The National Poisons Control Centre of the National Institute of Public Health and the Environment in the Netherlands conducted a prospective study on acute poisoning arising from exposure to pesticides in agricultural workers. The study was performed to determine the extent and severity of acute pesticide poisoning in the Netherlands and the working conditions that lead to these poisonings. All cases of potential acute occupational intoxication by pesticides in which the Poisons Control Centre was consulted in 1991 were thoroughly studied by an occupational hygienist and a specialist in internal medicine. With the consent of the patients and their physicians, the patients' medical condition and the working conditions leading to exposure were investigated on the spot. After the exclusion of 73 patients (27 non-occupational exposures, 7 occupational exposures in non-agricultural workers, 1 accident occurred abroad, 32 patients with illnesses unrelated to pesticides and 6 who could not be traced for follow-up), 54 cases of possible acute work-related pesticide poisoning remained for study. In 37 of the 54 events there was a direct relation between exposure to pesticides and acute health problems. In one patient doubt remained about the origin of the complaints and in 16 of the 54 cases pesticide poisoning was highly unlikely and the complaints could be attributed to other diseases. In the 37 remaining cases symptoms consisted of skin and/or eye lesions (23 cases) and systemic health effects (14 cases). Exposure to the soil disinfectant 1,3-dichloropropene resulted in severe skin damage. Direct contact of pesticides with the eyes invariability resulted in local irritation. Severe systemic poisonings occurred after exposure to organophosphate and carbamate insecticides and the soil disinfectant methyl bromide. Investigations at the site of the exposure revealed 43 cases of clear exposure to pesticides, in which, except for two cases, 1 worker per incident was involved. In 67% of the cases exposures took not place during pesticide dissemination, but during preparatory activities (35%), repair of application equipment (14%) and during re-entry (14%). In 79% of the cases splashing of pesticides or spray drift led to the exposure. In most accidents (74%) imperfect technical design or technical defects were important risk factors for exposure. Although most workers were aware of the risk of using pesticides, they were still careless in taking adequate protective measures. Especially during preparatory and reparations activities the wearing of protective clothing has to be emphasized.

Adolescent↗
PubMed1996

[Ivermectin: dangerous for dogs].

Given that the National Poisons Control Centre is regularly contacted about ivermectin intoxication in dogs, we would like to emphasize the warning of Nap et al. (4) that the use of ivermectin in companion animals, and especially Collies and Bobtails, is not without risk. For this reason, the 'off-label' use of ivermectin for these dogs is not advised. There is currently a wide choice of selective drugs for the treatment of canine parasitic diseases.

Animals↗