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Dive into the research topics where Jakob Kristinsson is active.

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Featured researches published by Jakob Kristinsson.


Forensic Science International | 1999

Drugged driving in the Nordic countries--a comparative study between five countries

A. S. Christophersen; G. Ceder; Jakob Kristinsson; Pirjo M. Lillsunde; Anni Steentoft

The purpose of this study was to compare whether the high incidence of drugged driving in Norway was different to that in the other Nordic countries. All blood samples received by Nordic forensic institutes during one week in 1996, from drivers suspected by the police of driving under the influence (Denmark: n = 255, Finland: n = 270, Iceland: n = 40, Sweden: n = 86, Norway: n = 149), were analysed for alcohol and drugs (benzodiazepines, cannabinoids, amphetamines, cocaine, opiates and a number of antidepressant drugs) independent of the primary suspicion, and using the same analytical cut-off levels at the different institutes. The primary suspicion was directed towards drugs in more than 40% of the Norwegian cases, drugs were detected in more than 70% of these samples. In only 0-3% of the cases from Denmark, Finland and Iceland, were drugs suspected, while the corresponding frequency for Sweden was 17%. However, evidential breath analyses were used for about three-quarters of the Swedish drivers suspected to be influenced by alcohol. Blood alcohol concentrations (BACs) below the legal limits were found in 32, 18 and 2% of the Norwegian, Icelandic and Finnish cases, respectively (BAC < 0.05%), in 10% of the Danish cases (BAC < 0.08%) and in 20% of the Swedish cases (BAC < 0.02%). Drugs were most frequently found in the Norwegian and Swedish cases with no alcohol (80-83%). Similar frequencies of drugs in samples with BACs above the legal limits (19-22%), were obtained for all countries. Benzodiazepines, tetrahydrocannabinol and amphetamine represented the most commonly detected drugs. Our results show that differences between Norway and other Nordic countries with regard to drugs and driving, are connected to the selection criteria made by the police and with more focus on drugged driving in Norway.


Journal of Addictive Diseases | 2004

Validity of Self-Reports and Drug Use Among Young People Seeking Treatment for Substance Abuse or Dependence

Elisabet Solbergsdottir; Gudbjorn Bjornsson; Larus S. Gudmundsson; Torarinn Tyrfingsson; Jakob Kristinsson

Abstract The present study assessed drug use and the validity of self-reports of drug use among young people seeking treatment. On admission the participants (n =316), 215 males and 101 females, were interviewed about their drug use. Urine samples were collected to screen for alcohol, amphetamine, benzodiazepines, cannabis, cocaine, methylenedioxymethamphetamine (MDMA) and opiate use. Self-reports of substance use were compared with urinalysis results. Seventy-three percent of the participants reported use of two or more substances. Single substance users were primarily alcohol users. Kappa agreement between self-report and urinalysis results was of acceptable concordance (≥ 0.65) except for alcohol (κ =0.19). Conditional kappa values were good (≥ 0.85) with exception of opiates (cond. κ =0.57). The self-reports were generally reliable among young people seeking treatment. No significant differences (p ≥ 0.54) were found in the validity of self-reports between the genders.


Accident Analysis & Prevention | 2011

Drugs related to motor vehicle crashes in northern European countries: A study of fatally injured drivers

Jørg Mørland; Anni Steentoft; Kirsten Wiese Simonsen; Ilkka Ojanperä; Erkki Vuori; Kristín Magnúsdóttir; Jakob Kristinsson; G. Ceder; Robert Kronstrand; Asbjørg S. Christophersen

The aim of this study was to find which drugs and drug combinations were most common in drivers who died, in particular, in single vehicle crashes where the responsibility for the crash would be referred to the driver killed. The study included all available blood samples from drivers, who died within 24h of the accident, in the years 2001 and 2002 in the five Nordic countries (total population about 24 million inhabitants). The samples were analysed for more than 200 different drugs in addition to alcohol, using a similar analytical programme and cut-off limits in all countries. In three countries (Finland, Norway and Sweden) blood samples were available for more than 70% of the drivers, allowing representative prevalence data to be collected. 60% of the drivers in single vehicle crashes had alcohol and/or drug in their blood samples, compared with 30% of drivers killed in collisions with other vehicles. In single vehicle accidents, 66% of the drivers under 30 years of age had alcohol and/or drugs in their blood (alcohol only - 40%; drugs only - 12%; alcohol and drugs - 14%). The drugs found were mostly illicit drugs and psychoactive medicinal drugs with warning labels (in 57% and 58% respectively of the drivers under 30 with drugs present). Similar findings were obtained for drivers 30-49 years of age (63% with alcohol and/or drugs). In drivers aged 50 years and above, killed in single vehicle crashes (48% with alcohol and/or drugs) illicit drugs were found in only one case, and psychoactive medicinal drugs were detected less frequently than in younger age groups. In 75% of single vehicle crashes, the driver was under 50 years. Thus, the majority of accidents where the drivers must be considered responsible, occurred with drivers who had recently used alcohol, or drugs, alone or in combination. The drugs involved were often illicit and/or psychoactive drugs with warning labels. Therefore a large proportion of single vehicle accidents appear to be preventable, if more effective measures against driving after intake of alcohol and drugs can be implemented.


Clinical Toxicology | 2008

Acute poisonings in Iceland: A prospective nationwide study

Jakob Kristinsson; Runolfur Palsson; Gudborg A. Gudjonsdottir; Margret Blondal; Sigurdur Gudmundsson; Curtis P. Snook

Introduction. Poisoning is a common cause of emergency visits and hospital admission in Western countries. The purpose of this study was to assess the incidence and type of toxic exposures presenting to emergency medical facilities in Iceland. Materials and methods. The study was prospective and included all patients with confirmed or suspected poisoning presenting to hospitals and rural medical centers providing emergency services in Iceland during the twelve-month period from April 2001 until March 2002. Results. A total of 1,121 toxic exposures were documented representing an incidence of 3.91 cases per 1,000 inhabitants per year. The female to male ratio was 1.23. The majority of exposures (56.7%) occurred in the patients home, 60% were deliberate, 72% had drugs and/or alcohol as their main cause, and 11% involved illicit drugs. Exposures to chemicals other than drugs were usually unintentional. Conclusion. Toxic exposures requiring emergency medical care are common in Iceland. Self-poisonings by ingestion of prescription drugs and/or alcohol accounted for the majority of cases.


Journal of the Neurological Sciences | 2006

Ceruloplasmin and superoxide dismutase (SOD1) in Parkinson's disease: a follow-up study.

Gudlaug Tórsdóttir; Sigurlaug Sveinbjörnsdóttir; Jakob Kristinsson; Jon Snaedal; Torkell Jóhannesson

In this follow-up study concentration, oxidative activity and specific oxidative activity of ceruloplasmin (CP) in serum and the activity of superoxide dismutase (SOD1) in erythrocytes were reexamined in 28 of originally 40 patients with Parkinsons disease (PD), and their age- and gender-matched controls. The mean CP and SOD1 parameters were significantly lower in the patients than in the controls. SOD1 activity and age of the patients were inversely correlated. The patients were divided into two subgroups based on their H&Y score i.e. groups II and III (12 patients) versus groups IV and V (16 patients). No significant difference was found in the CP or SOD1 parameters between the subgroups. Patients were also divided into two subgroups based on treatment with levodopa and decarboxylase blocker alone (12 patients) or given additionally a dopamine agonist (15 patients). No significant difference in the parameters was found between these subgroups in relation to intake of dopamine agonists. Results of this study are in agreement with results of the former study 5 years earlier. There is considerable overlap in individual values between patients and controls of the parameters studied. Thus CP and SOD1 have no obvious value for diagnosis or clinical evaluation of PD.


Neuropsychiatric Disease and Treatment | 2012

Ceruloplasmin and iron in Alzheimer's disease and Parkinson's disease: a synopsis of recent studies.

Jakob Kristinsson; Jon Snaedal; Gudlaug Tórsdóttir; Torkell Jóhannesson

Ceruloplasmin (Cp) concentration and oxidative activity in serum are lowered in Parkinson’s disease (PD). In most PD patients, iron increases in the substantia nigra in the midbrain. In PD, the low Cp concentration and activity in serum and the high iron amounts in the substantia nigra appears to be correlated. An hereditary background is common in PD and variations in the Cp gene that have been found in PD are associated with high iron levels in the substantia nigra. Variations in Cp synthesis and in the incorporation of copper into the Cp molecule are essential features of PD. In Alzheimer’s disease (AD), the Cp activity in serum is lowered but not the concentration, except in the advanced stages of the disease. Generally, iron is not increased in the AD brain. In the AD brain, iron accumulates in neuritic plaques and in neurofibrillary tangles. There is also increased risk of iron-mediated tissue damage, which may possibly be counteracted by Cp. At the same time, the AD brain is short in copper, which presumably results in the deficient activity of many copper enzymes in the brain, in addition to Cp. Lowered Cp activity in serum most likely stems from lessened incorporation of copper in the Cp molecule and similar incorporation defects might also apply to other copper enzymes in AD.


Journal of the Neurological Sciences | 2010

Case–control studies on ceruloplasmin and superoxide dismutase (SOD1) in neurodegenerative diseases: A short review

Gudlaug Tórsdóttir; Jakob Kristinsson; Jon Snaedal; Sigurlaug Sveinbjörnsdóttir; Gretar Gudmundsson; Stefán Hreidarsson; Torkell Jóhannesson

This short review describes a series of case-control studies on the concentration and oxidative activity of ceruloplasmin (CP) in serum and the activity of superoxide dismutase (SOD1) in erythrocytes in patients with Alzheimers disease (AD), Parkinsons disease (PD) and Downs syndrome (DS). The same parameters were re-examined in the PD patients 5 years later. The specific oxidative activity (oxidative activity related to mass) of CP was calculated in PD and DS. In AD and PD the oxidative activity of CP and SOD1 activity was significantly lower in patients than controls. The specific oxidative activity of CP was also significantly lower in PD patients. The difference in all parameters determined was still present 5 years later in PD patients. There was no difference in the concentration or activity of CP in patients with DS and controls. Because of the gene-dose effect (the gene for SOD1 is located on chromosome 21); the SOD1 activity was 50% higher in the patients than the controls. The CP specific oxidative activity and SOD1 activity were found to be significantly lower in the older (>40 years) than the younger DS patients. Whether changes in CP and SOD1 in AD, PD and DS are primary changes or a result of prolonged disease burden needs to be examined.


Clinical Toxicology | 2000

Severe Atenolol and Diltiazem Overdose

Curtis P. Snook; Kristinn Sigvaldason; Jakob Kristinsson

Case Report: A case of combined, massive overdose of both atenolol and diltiazem in an adult male is reported. Cardiac arrest ensued which was responsive to cardiopulmonary resuscitation. Bradycardia, hypotension, and oliguria followed which were resistant to intravenous pacing and multiple pharmacologic interventions, including intravenous fluids, calcium, dopamine, dobutamine, epinephrine, prenalterol, and glucagon. Adequate mean arterial pressure and urine output were restored only after addition of phenylephrine to therapy with multiple agents and transvenous pacing. The patient survived until discharge after a hospital course complicated by nontransmural myocardial infarct on hospital day 4 and pneumonia. Laboratory testing subsequently revealed high serum levels of both atenolol and diltiazem. The atenolol level of 35 μg/mL in this patient is the highest reported associated with survival. Conclusion: This case illustrates severe cardiovascular toxicity after overdose of both atenolol and diltiazem. Oliguria, which has previously been reported in severe atenolol overdose, was successfully treated without hemodialysis by the addition of phenylephrine to aggressive therapy with pacing, inotropic, and pressor support.


Dementia and geriatric cognitive disorders extra | 2011

Ceruloplasmin and Iron Proteins in the Serum of Patients with Alzheimer’s Disease

Gudlaug Tórsdóttir; Jakob Kristinsson; Jon Snaedal; Torkell Jóhannesson

Backgrounds/Aims: The oxidative activity of ceruloplasmin (CP) in serum has been found to be lowered in patients with Alzheimer’s disease (AD). We investigated whether changes in CP were reflected by altered iron parameters in AD patients. Methods: Iron parameters, and CP concentration, activity and specific activity were determined in the serum of 41 AD patients and controls. Results: CP activity and specific activity were significantly lower in the AD patients. CP concentration and activity were negatively correlated with the ferritin concentration in both groups. CP concentration was positively correlated with age in the control group but not in the patients group. Conclusion: The lowered CP activity in the serum of AD patients was not reflected by the iron parameters. As CP concentration only rises with age in the controls, this may indicate failing adaption to age-related alterations in iron metabolism in AD patients.


Acta Veterinaria Scandinavica | 2006

Iron and iron/manganese ratio in forage from Icelandic sheep farms: relation to scrapie

Kristín Björg Gudmundsdóttir; Sigurdur Sigurdarson; Jakob Kristinsson; Tryggvi Eiríksson; Torkell Jóhannesson

This study was undertaken in order to examine whether any connection existed between the amounts of iron in forage and the sporadic occurrence of scrapie observed in certain parts of Iceland. As iron and manganese are considered antagonistic in plants, calculation of the Fe/Mn ratios was also included by using results from Mn determination earlier performed in the same samples. Forage samples (n = 170) from the summer harvests of 2001–2003, were collected from 47 farms for iron and manganese analysis. The farms were divided into four categories: 1. Scrapie-free farms in scrapie-free areas (n = 9); 2. Scrapie-free farms in scrapie-afflicted areas (n = 17); 3. Scrapie-prone farms (earlier scrapie-afflicted, restocked farms) (n = 12); 4. Scrapie-afflicted farms (n = 9). Farms in categories 1 and 2 are collectively referred to as scrapie-free farms. The mean iron concentration in forage samples from scrapie-afflicted farms was significantly higher than in forage samples from farms in the other scrapie categories (P = 0.001). The mean Fe/Mn ratio in forage from scrapie-afflicted farms was significantly higher than in forage from scrapie-free and scrapie-prone farms (P < 0.001). The results indicated relative dominance of iron over manganese in forage from scrapie-afflicted farms as compared to farms in the other categories. Thus thorough knowledge of iron, along with manganese, in soil and vegetation on sheep farms could be a pivot in studies on sporadic scrapie.

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Anni Steentoft

University of Copenhagen

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Erkki Vuori

University of Helsinki

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Tryggvi Eiríksson

Agricultural University of Iceland

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