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Dive into the research topics where Jan van Amsterdam is active.

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Featured researches published by Jan van Amsterdam.


Drug Safety | 1998

ACE inhibitor-induced angioedema. Incidence, prevention and management.

Wim Vleeming; Jan van Amsterdam; Bruno H. Stricker; Dick J. De Wildt

SummaryAvailable information from 1980 to 1997 on angiotensin converting enzyme (ACE) inhibitor-induced angioedema and its underlying mechanisms are summarised and discussed. The incidence of angioedema is low (0.1 to 0.2%) but can be considered as a potentially life-threatening adverse effect of ACE inhibitor therapy. This adverse effect of ACE inhibitors, irrespective of the chemical structure, can occur early in treatment as well as after prolonged exposure for up to several years. The estimated incidence is quite underestimated. The actual incidence can be far higher because of poorly recognised presentation of angioedema as a consequence of its late onset in combination with usually long term therapy. Also, a spontaneous reporting bias can contribute to an actual higher incidence of this phenomenon. The incidence can be even higher (up to 3-fold) in certain risk groups, for instance Black Americans. Treatment includes immediate withdrawal of the ACE inhibitor and acute symptomatic supportive therapy followed by immediate (and long term) alternative therapy with other classes of drugs to manage hypertension and/or heart failure.Preclinical and clinical studies for the elucidation of the underlying mechanism(s) of ACE inhibitor-associated angioedema have not generated definite conclusions. It is suggested that immunological processes and several mediator systems (bradykinin, histamine, substance P and prostaglandins) are involved in the pathogenesis of angioedema. A great part of all reviewed reports suggest a relationship between ACE inhibitor-induced angioedema and increased levels of (tissue) bradykinin. However, no conclusive evidence of the role of bradykinin in angioedema has been found and an exclusive role of bradykinin seems unlikely. So far, no clear-cut evidence for an immune-mediated pathogenesis has been found. In addition, ACE gene polymorphism and some enzyme deficiencies are proposed to be involved in ACE inhibitor-induced angioedema. Progress in pharmacogenetic and molecular biological research should throw more light on a possible genetic component in the pathogenesis of ACE inhibitor-associated angioedema.


Regulatory Toxicology and Pharmacology | 2010

Adverse health effects of anabolic-androgenic steroids.

Jan van Amsterdam; A. Opperhuizen; F. Hartgens

Anabolic-androgenic steroids (AAS) are synthetic drugs derived from testosterone. Illegally, these drugs are regularly self-administered by body builders and power lifters to enhance their sportive performance. Adverse side effects of AAS include sexual dysfunction, alterations of the cardiovascular system, psyche and behavior, and liver toxicity. However, severe side effects appear only following prolonged use of AAS at high dose and their occurrence is limited. Occasionally, AAS abuse may be linked to certain social and psychological traits of the user, like low self-esteem, low self-confidence, suffered hostility, childhood conduct disorder, and tendency to high-risk behavior. The overwhelming stereotype about AAS is that these compounds cause aggressive behavior in males. However, the underlying personality traits of a specific subgroup of the AAS abusers, who show aggression and hostility, may be relevant, as well. Use of AAS in combination with alcohol largely increases the risk of violence and aggression. The dependence liability of AAS is very low, and withdrawal effects are relatively mild. Based on the scores for acute and chronic adverse health effects, the prevalence of use, social harm and criminality, AAS were ranked among 19 illicit drugs as a group of drugs with a relatively low harm.


European Neuropsychopharmacology | 2007

Role of acetaldehyde in tobacco smoke addiction.

Reinskje Talhout; Antoon Opperhuizen; Jan van Amsterdam

This review evaluates the presumed contribution of acetaldehyde to tobacco smoke addiction. In rodents, acetaldehyde induces reinforcing effects, and acts in concert with nicotine. Harman and salsolinol, condensation products of acetaldehyde and biogenic amines, may be responsible for the observed reinforcing effect of acetaldehyde. Harman and salsolinol inhibit monoamine oxidase (MAO), and some MAO-inhibitors are known to increase nicotine self-administration and maintain behavioural sensitization to nicotine. Harman is formed in cigarette smoke, and blood harman levels appear to be 2-10 times higher compared to non-smokers. Since harman readily passes the blood-brain barrier and has sufficient MAO-inhibiting potency, it may contribute to the lower MAO-activity observed in the brain of smokers. In contrast, the minor amounts of salsolinol that can be formed in vivo most likely do not contribute to tobacco addiction. Thus, acetaldehyde may increase the addictive potential of tobacco products via the formation of acetaldehyde-biogenic amine adducts in cigarette smoke and/or in vivo, but further research is necessary to substantiate this hypothesis.


European Addiction Research | 2010

Ranking the harm of alcohol, tobacco and illicit drugs for the individual and the population.

Jan van Amsterdam; Antoon Opperhuizen; Maarten W. J. Koeter; Wim van den Brink

Drug policy makers continuously face a changing pattern of drug use, i.e. new drugs appear on the market, the popularity of certain drugs changes or drugs are used in another way or another combination. For legislative purposes, drugs have mostly been classified according to their addictive potency. Such classifications, however, lack a scientific basis. The present study describes the results of a risk assessment study where 19 recreational drugs (17 illicit drugs plus alcohol and tobacco) used in the Netherlands have been ranked by a Dutch expert panel according to their harm based on the scientific state of the art. The study applies a similar approach as recently applied by Nutt et al. [Lancet 2007;369:1047–1053], so that the results of both studies could be compared. The harm indicators scored are acute and chronic toxicity, addictive potency and social harm. The aim of this study is to evaluate whether the legal classification of drugs in the Netherlands corresponds with the ranking of the drugs according to their science-based ranking of harm. Based on the results, recommendations are formulated about the legal classification of recreational drugs at national and international level which serves a rational approach for drug control.


Journal of Psychopharmacology | 2015

The adverse health effects of synthetic cannabinoids with emphasis on psychosis-like effects

Jan van Amsterdam; Tibor M. Brunt; Wim van den Brink

Cannabis use is associated with an increased risk of psychosis in vulnerable individuals. Cannabis containing high levels of the partial cannabinoid receptor subtype 1 (CB1) agonist tetrahydrocannabinol (THC) is associated with the induction of psychosis in susceptible subjects and with the development of schizophrenia, whereas the use of cannabis variants with relatively high levels of cannabidiol (CBD) is associated with fewer psychotic experiences. Synthetic cannabinoid receptor agonists (SCRAs) are full agonists and often more potent than THC. Moreover, in contrast to natural cannabis, SCRAs preparations contain no CBD so that these drugs may have a higher psychosis-inducing potential than cannabis. This paper reviews the general toxicity profile and the adverse effects of SCRAs with special emphasis on their psychosis-inducing risk. The review shows that, compared with the use of natural cannabis, the use of SCRAs may cause more frequent and more severe unwanted negative effects, especially in younger, inexperienced users. Psychosis and psychosis-like conditions seem to occur relatively often following the use of SCRAs, presumably due to their high potency and the absence of CBD in the preparations. Studies on the relative risk of SCRAs compared with natural cannabis to induce or evoke psychosis are urgently needed.


Archives of Environmental Health | 2001

Traffic-related air pollution affects peak expiratory flow, exhaled nitric oxide, and inflammatory nasal markers

P.A. Steerenberg; Stefan Nierkens; Paul H. Fischer; Henk van Loveren; A. Opperhuizen; Jef Vos; Jan van Amsterdam

Abstract The authors used a longitudinal observational design, with repeated measures, to study the association between traffic-related air pollutants (i.e., nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke) and respiratory symptoms. Subjects (N = 82) attended an elementary school in either Utrecht (i.e., urban children) or Bilthoven (i.e., suburban children). These two geographic areas differed with respect to levels of Black Smoke (means = 53 μg/m3 and 18 μg/m3, respectively). Levels of nitric oxide, nitrogen dioxide, carbon monoxide, and Black Smoke were consistently higher in Utrecht than in Bilthoven (mean daily ratios were 8,1.5, 1.8, and 2.7, respectively). The authors compared mean levels of short-term effects of the aforementioned air pollutants on suburban and urban children. Urban children had higher mean levels (p = .05) of interleukin-8 (32%), urea (39%), uric acid (26%), albumin (15%), and nitric oxide metabolites (21 %) in nasal lavage than did suburban children. Peak expiratory flow, exhaled nitric oxide levels, and nasal markers were associated with levels of particulate matter with diameters less than or equal to 10 urn, Black Smoke, nitrogen dioxide, and nitric oxide. With respect to per-unit increases in air pollution, urban children had more increased peak expiratory flow, higher levels of exhaled nitric oxide, and more increased release of uric acid, urea, and nitric oxide metabolites than suburban children. In summary, urban children had increased levels of inflammatory nasal markers, and their responses were more pronounced than were the suburban childrens responses to the same increments of air pollution.


Addiction | 2014

Cross-sectional and prospective relation of cannabis potency, dosing and smoking behaviour with cannabis dependence: an ecological study

Peggy van der Pol; Nienke Liebregts; Tibor M. Brunt; Jan van Amsterdam; Ron de Graaf; D.J. Korf; Wim van den Brink; Margriet van Laar

BACKGROUND AND AIMS Increased delta-9-tetrahydrocannabinol (THC) concentrations in cannabis may lead to higher THC exposure, cannabis dependence and treatment need, but users may also adapt the actual intake of THC through reduced inhalation of THC containing smoke (titration). We investigated whether consumers of stronger cannabis use less cannabis per joint or inhale less smoke than those using less potent cannabis and whether these factors predict cannabis dependence severity. METHODS Heavy cannabis users (n = 98) brought their own cannabis, rolled a joint and smoked it ad libitum in a naturalistic setting. We analysed the content of the joint, its association with smoking behaviour and the cross-sectional and prospective (1.5-year follow-up) relations between smoking behaviour and cannabis dependence severity (total number of DSM-IV dependence symptoms). RESULTS THC concentration in cannabis (range 1.10-24.70%) was correlated positively with cannabis dose per joint (b = 0.008, P = 0.01), but the resulting THC concentration per joint (range 0.24-15.72%) was associated negatively with inhalation volume (b = -0.05, P = 0.03). Smoking behaviour measures (number of puffs, inhaled volume, reduction of puff volume and puff duration while smoking) predicted follow-up dependence severity, independently of baseline dependence severity and monthly THC dose (number of joints × cannabis dose × cannabis THC concentration). Monthly THC dose only predicted follow-up dependence severity when unadjusted for baseline severity. CONCLUSIONS Cannabis users titrate their delta-9-tetrahydrocannabinol intake by inhaling lower volumes of smoke when smoking strong joints, but this does not fully compensate for the higher cannabis doses per joint when using strong cannabis. Thus, users of more potent cannabis are generally exposed to more delta-9-tetrahydrocannabinol. Smoking behaviour appears to be a stronger predictor for cannabis dependence severity than monthly delta-9-tetrahydrocannabinol dose.


Psychiatry Research-neuroimaging | 1999

Nitric oxide and biopterin in depression and stress

Jan van Amsterdam; A. Opperhuizen

Depression has been hypothesized to be related to the reduced biosynthesis of neurotransmitters such as serotonin, noradrenalin and dopamine. Much past research has also been devoted to dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis in depression. The present article reviews the evidence linking tetrahydrobiopterin, a co-factor in the biosynthesis of neurotransmitters, and nitric oxide, an apparent neuroendocrine modulator of the HPA axis, to the immune system and to neuronal control within affective disorder and stress. On the basis of this review, it is suggested that future psychoneuroimmunological research should more fully explore the possible role of tetrahydrobiopterin and nitric oxide in depressive disorders.


Archives of Environmental Health | 1999

Air Pollution is Associated with Increased Level of Exhaled Nitric Oxide in Nonsmoking Healthy Subjects

Jan van Amsterdam; Bert Verlaan; Henk van Loveren; Bernhard G. V. Elzakker; Sjef G. Vos; A. Opperhuizen; P.A. Steerenberg

The authors sought to determine which air pollutant is responsible for the increase in exhaled nitric oxide observed in healthy subjects. Exhaled nitric oxide was measured in 16 nonsmoking healthy subjects on 14 workdays, during which there were varying air-pollution levels. Contamination of samples by ambient nitric oxide was excluded. The baseline value of exhaled nitric oxide, determined at times when outdoor air pollution was low, ranged from 7 to 43 ppb (mean = 28+/-5 ppb). The daily value of exhaled nitric oxide (range = 5-60 ppb) was associated positively with ambient carbon monoxide (r = .85) and nitric oxide (r = .81). Exposure during the morning hours to high levels of outdoor pollution was associated with increased exhaled nitric oxide (i.e., 50% above baseline), which persisted for up to 5 h (i.e., 32% above baseline). These results indicated that exhaled nitric oxide levels represent a useful biomonitor of individual exposure to air pollutants.


Regulatory Toxicology and Pharmacology | 2011

Harm potential of magic mushroom use: A review

Jan van Amsterdam; Antoon Opperhuizen; Wim van den Brink

In 2007, the Minister of Health of the Netherlands requested the CAM (Coordination point Assessment and Monitoring new drugs) to assess the overall risk of magic mushrooms. The present paper is an updated redraft of the review, written to support the assessment by CAM experts. It summarizes the literature on physical or psychological dependence, acute and chronic toxicity, risk for public health and criminal aspects related to the consumption of magic mushrooms. In the Netherlands, the prevalence of magic mushroom use was declining since 2000 (last year prevalence of 6.3% in 2000 to 2.9% in 2005), and further declined after possession and use became illegal in December 2008. The CAM concluded that the physical and psychological dependence potential of magic mushrooms was low, that acute toxicity was moderate, chronic toxicity low and public health and criminal aspects negligible. The combined use of mushrooms and alcohol and the quality of the setting in which magic mushrooms are used deserve, however, attention. In conclusion, the use of magic mushrooms is relatively safe as only few and relatively mild adverse effects have been reported. The low prevalent but unpredictable provocation of panic attacks and flash-backs remain, however, a point of concern.

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Wim Vleeming

University of Amsterdam

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P.A. Steerenberg

Leiden University Medical Center

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