Biomedical subjects

P J Jørgensen

Publications and source records attributed to P J Jørgensen.

At least 19 recordsLinked to original sources

PubMed2000

Maternal seafood diet, methylmercury exposure, and neonatal neurologic function.

OBJECTIVE: To determine whether neonatal neurologic function is adversely affected by seafood contaminants from maternal diet during pregnancy. STUDY DESIGN: One hundred eighty-two singleton term births were evaluated in the Faeroe Islands, where marine food includes pilot whale. Maternal serum, hair, and milk and umbilical cord blood were analyzed for contaminants. Levels of essential fatty acids, selenium, and thyroid hormones were determined in cord blood. Each infant's neurologic optimality score was determined at 2 weeks of age adjusted for gestational age, and predictors were assessed by regression analysis. RESULTS: Exposures to methylmercury and polychlorinated biphenyls were increased in relation to maternal seafood intake, as were omega3 fatty acid concentrations in cord serum. Thyroid function was normal. After adjustment for confounders, a 10-fold increase of the cord-blood mercury concentration was associated with a decreased neurologic optimality score of 2.0 (P =. 03). This effect corresponds to a decrease in gestational age of about 3 weeks. Other indicators of the seafood diet had no effect on this outcome. CONCLUSIONS: Prenatal exposure to methylmercury from contaminated seafood was associated with an increased risk of neurodevelopmental deficit. Thus in this North Atlantic population, methylmercury constituted an important neurologic risk factor, although effects of other seafood components were not detectable.

Adult↗

PubMed2000

Biochemical markers of ischaemia for the early identification of acute myocardial infarction without St segment elevation.

Blood was collected on admission and after 1-2 h in 130 consecutive patients admitted with typical chest pain in order to assess the capacity of myoglobin, fatty-acid-binding protein (FABP), CK-MB mass, and troponin I (TnI) in the early identification of acute myocardial infarction (AMI) without ST elevation. Using the maximum value within 6 h of onset of symptoms, AMI was detected with a 90-95% sensitivity and a 81-94% specificity by FABP at a cut-off level 8-12 midrog/l, or 81-86% and 89-93%, respectively, by myoglobin at a cut-off level 70-90 microg/l. CK-MB mass and TnI had low sensitivity, albeit very high specificity. As almost all AMI patients were identified within 6 h, serial measurements of FABP or myoglobin ruled out AMI with a very high degree of certainty. Due to the low prevalence of AMI (16%), the positive predictive values were modest (47-73%), yet increasing the probability of AMI by a factor 3-4. Myoglobin and FABP are very useful markers in the early triage of chest pain patients.

Adult↗

PubMed1999

Methylmercury exposure biomarkers as indicators of neurotoxicity in children aged 7 years.

The mercury concentration in blood or scalp hair has been widely used as a biomarker for methylmercury exposure. Because of the increased risks associated with exposures during prenatal and early postnatal development, biomarker results must be interpreted with regard to the age-dependent susceptibility. The authors compared regression coefficients for five sets of exposure biomarkers in 917 children from the Faroe Islands examined at birth, 1 year, and 7 years. Outcome variables were the results of neuropsychologic examination carried out in 1993-1994 at age 7 years. After adjustment for covariates, the cord-blood concentration showed the clearest associations with deficits in language, attention, and memory. Fine-motor function deficits were particularly associated with the maternal hair mercury at parturition. Mercury concentrations in the child's blood and hair at age 7 years were significant predictors only of performance on memory for visuospatial information. These findings emphasize the usefulness of the cord-blood mercury concentration as a main risk indicator. They also support the notion that the greatest susceptibility to methylmercury neurotoxicity occurs during late gestation, while early postnatal vulnerability is less, and they suggest that the time-dependent susceptibility may vary for different brain functions.

Biomarkers↗

PubMed1999

Absorption and retention of nickel from drinking water in relation to food intake and nickel sensitivity.

Two studies were performed to examine the influence of fasting and food intake on the absorption and retention of nickel added to drinking water and to determine if nickel sensitization played any role in this regard. First, eight nonallergic male volunteers fasted overnight before being given nickel in drinking water (12 micrograms Ni/kg) and, at different time intervals, standardized 1400-kJ portions of scrambled eggs. When nickel was ingested in water 30 min or 1 h prior to the meal, peak nickel concentrations in serum occurred 1 h after the water intake, and the peak was 13-fold higher than the one seen 1 h after simultaneous intake of nickel-containing water and scrambled eggs. In the latter case, a smaller, delayed peak occurred 3 h after the meal. Median urinary nickel excretion half-times varied between 19.9 and 26.7 h. Within 3 days, the amount of nickel excreted corresponded to 2.5% of the nickel ingested when it was mixed into the scrambled eggs. Increasing amounts were excreted as the interval between the water and the meal increased, with 25.8% of the administered dose being excreted when the eggs were served 4 h prior to the nickel-containing drinking water. In the second experiment, a stable nickel isotope, 61Ni, was given in drinking water to 20 nickel-sensitized women and 20 age-matched controls, both groups having vesicular hand eczema of the pompholyx type. Nine of 20 nickel allergic eczema patients experienced aggravation of hand eczema after nickel administration, and three also developed a maculopapular exanthema. No exacerbation was seen in the control group. The course of nickel absorption and excretion in the allergic groups did not differ and was similar to the pattern seen in the first study, although the absorption in the women was less. A sex-related difference in gastric emptying rates may play a role. Thus, food intake and gastric emptying are of substantial significance for the bioavailability of nickel from aqueous solutions.

Absorption↗

PubMed1999

Improvement in semen quality associated with decreasing occupational lead exposure.

BACKGROUND: Cross-sectional studies have suggested that occupational lead exposure may adversely affect sperm quality. METHODS: Sperm quality changes were prospectively assessed in 19 men employed at a car battery plant where efforts were made to decrease the exposure level. The participants delivered monthly samples of semen and venous blood during their employment at the factory. The factory then closed, and additional samples were obtained from 16 of the men. RESULTS: Average blood-lead concentrations decreased from 2.03 mumol/l to 0.96 mumol/l during the observation period. Concomitantly, significant improvements were seen in the proportion of motile cells both at sample delivery and after 24 hr, and in penetration. However, the sperm cell concentration and the proportion of morphological abnormalities did not change. CONCLUSIONS: These results support the notion that occupational lead exposure at currently acceptable levels has a small adverse effect on sperm quality, especially sperm motility, and that this effect is at least partially reversible.

Adult↗

PubMed1999

Tremor frequency patterns in mercury vapor exposure, compared with early Parkinson's disease and essential tremor.

A new portable tremometer allows determination of tremor intensities at different tremor frequencies. Based on past studies, two tremor frequency windows of similar size were chosen at 3.0-6.5 Hz and 6.6-10.0 Hz to reflect major tremor intensities in Parkinson's disease and mercury vapor poisoning, respectively. In 81 healthy controls, total tremor intensity was higher for the preferred hand and depended on age. Ten patients treated for Parkinson's disease showed substantially increased tremor intensity, especially within the low-frequency window. This pattern was also apparent in 14 patients with de novo Parkinson's disease whose overall tremor intensity was only mildly elevated. In contrast, ten patients with essential tremor had peak frequencies in both windows, and some patients had increased tremor on one side only. Sixty-three Brazilian gold traders exposed to mercury vapor showed increased tremor predominantly in the high-frequency window. Three of the gold traders had a narrower tremor peak at frequencies of 7-8 Hz. While the urine-mercury concentration was significantly associated with the current number of burning sessions per week, it did not correlate with tremor intensities. However, eight traders had a urinary mercury excretion level above 50 microg and at the same time a greatly increased average tremor intensity within the high-frequency window. These patterns were statistically significant for relative tremor intensities, but were less clear when total intensities were used. These observations suggest that the relative distribution of tremor intensities in specific frequency bands may be a valuable supplement to current diagnostic methods for subjects with mercury vapor exposure.

Adult↗

PubMed1998

[Blood lead concentration in the Danish population after introduction of lead-free gasoline].

Blood lead concentrations in a Danish reference population were related to information from an extensive questionnaire on work, environment and life style. The mean concentration of lead in blood was 0.167 mumol/L, i.e. significantly lower than in previous studies. This finding is in accordance with the fact that less than 10% of petrol used in Denmark contained lead additives (up to 0.15 g/L). An important finding was that the well-documented predictors for lead in blood at higher concentration levels, such as age, gender, menopausal status, and intake of alcohol, are still valid in a low-level exposure situation. In addition, a strong and negative correlation was found between blood lead concentrations and dietary supplementation with vitamins and minerals. The present data indicate that lead exposure may still constitute a health risk in a small proportion of adult males and postmenopausal women.

Adult↗

PubMed1998

Predictors of blood lead concentrations in the lead-free gasoline era.

OBJECTIVES: Blood lead concentrations in a Danish reference population were related to information from an extensive questionnaire on work, environment, and life-style. METHODS: Data were gathered for 209 persons by means of a questionnaire and blood lead analyses. RESULTS: The mean concentration of lead in blood was 0.167 micromol/l (ie, significantly lower than in previous studies). This finding is in accordance with the fact that less than 10% of the gasoline used in Denmark contains lead additives (up to 0.15 g/l). An important finding was that the well-documented predictors for lead in blood at higher concentration levels, such as age, gender, menopausal status, and intake of alcohol, are still valid in a low-level exposure situation. In addition, a strong and negative correlation was found between blood lead concentrations and dietary supplementation with vitamins and minerals. CONCLUSIONS: The present data indicate that lead exposure may still constitute a health risk in a small proportion of adult men and postmenopausal women.

Adolescent↗

PubMed1997

Placebo response in environmental disease. Chelation therapy of patients with symptoms attributed to amalgam fillings.

Treatment of patients who attribute their environmental illness to mercury from amalgam fillings is largely experimental. On the Symptom Check List, overall distress, and somatization, obsessive-compulsive, depression, and anxiety symptom dimensions, were increased in 50 consecutive patients examined, and Eysenck Personality Questionnaire scores suggested less extroversion and increased degree of emotional liability. Succimer (meso-2, 3-dimercaptosuccinic acid) was given at a daily dose of 30 mg/kg for five days in a double-blind, randomized placebo-controlled trial. Urinary excretion of mercury and lead was considerably increased in the patients who received the chelator. Immediately after the treatment and 5 to 6 weeks later, most distress dimensions had improved considerably, but there was no difference between the succimer and placebo groups. These findings suggest that some patients with environmental illness may substantially benefit from placebo.

Adult↗

PubMed1996

Metal excretion and magnesium retention in patients with intermittent claudication treated with intravenous disodium EDTA.

Sixty patients with intermittent claudication participated in a double-blind placebo-controlled trial of 20 courses of intravenous chelation therapy with 3 g of disodium EDTA vs placebo during 5-9 weeks. After the first infusion, the 24-h urinary excretion of lead and zinc was approximately 25-fold higher in the EDTA-treated group; relative differences for copper and calcium were smaller. Urinary magnesium excretion in the EDTA-treated group was one-third less than in the control group. After the treatment period, the blood lead concentration had decreased by approximately 73% and the serum zinc concentration by approximately 34%; other changes in blood concentrations were negligible. The loss of essential minerals and the possible redistribution of lead in the body may constitute a disadvantage that should be taken into account in repeated intravenous EDTA treatment.

Adult↗

PubMed1995

Relation of a seafood diet to mercury, selenium, arsenic, and polychlorinated biphenyl and other organochlorine concentrations in human milk.

Human transition milk was sampled from 88 mothers at the Faroe Islands, where the seafood diet includes pilot whale meat and blubber. Milk mercury concentrations (median, 2.45 micrograms/liter) were significantly associated with mercury concentrations in cord blood and with the frequency of pilot whale dinners during pregnancy. Milk selenium concentrations (mean, 19.1 micrograms/liter) correlated significantly with concentrations in cord blood but not with seafood consumption. Arsenic concentrations were very low. Twenty-four of the milk samples were separated into four pools based on fish intake and milk mercury concentrations. The polychlorinated biphenyl (PCB) concentrations (1.8-3.5 micrograms/g lipid) were high and mainly due to congener numbers 153, 180, and 138. One pool contained a congener 77 concentration of 1380 ppt, which is the highest ever reported in a human specimen for a coplanar PCB. The highest PCB concentrations were seen in the pools from women who had eaten frequent whale dinners and whose milk contained high mercury concentrations. The concentrations of chlorinated dibenzo-p-dioxins and furans were not similarly elevated. Given the advantages associated with breast-feeding, advice to nursing mothers in this population should take into regard the possible risks associated with long-term exposure to milk contaminants.

Adult↗

PubMed1994

Human ventricular myosin light chain isotype 1 as a marker of myocardial injury.

A monoclonal enzyme immunoassay for measuring human ventricular myosin light chain isotype 1 (HVMLC1) in serum has been developed. To evaluate the method in patients with suspected myocardial injury, we studied 51 patients (16 acute myocardial infarction (AMI), 19 unstable angina pectoris (UAP), 9 stable angina pectoris, 3 nonischemic heart disease, 4 hip surgery patients), and 190 controls (blood donors). Serial blood-samples were drawn from patients; a single blood-sample from controls. The diagnostic value of the HVMLC1 assay was compared with total creatine kinase (CK), CKMB activity, CKMB mass concentration, lactate dehydrogenase isoenzyme 1 (LD1), troponin T (TnT) and mitochondrial-aspartate aminotransferase (m-ASAT). The detection limit of HVMLC1 was 0.4 microgram/l (linear range 0-20 micrograms/l). Sera from 190 reference persons did not contain detectable levels of HVMLC1 (< 0.4 microgram/l; 99% percentile). The coefficients of variation were 13% (1.0 microgram/l) and 3.1% (17.7 micrograms/l). Cross-reactivity with myosin from skeletal muscle was seen. Times to peak value were: CK 19.3 +/- 2.0, LD1 43.4 +/- 3.2, HVMLC1 72.9 +/- 7.0, and m-ASAT 67.3 +/- 5.6 h. Time-curves of HVMLC1 and m-ASAT were similar, whereas time-curves for HVMLC1 and TnT were quite different in most cases. Peak value of HVMLC1 was five times higher than CK peak value and eight times that of LD1. HVMLC1 appeared in the blood within hours after the onset of chest pain and in the majority remained for more than a week after AMI. Among patients with UAP 16% (3/19) had elevated HVMLC1 in serum, whereas elevated TnT was seen in 26% (5/19) and elevated CKMB mass in 26% (5/19). We conclude that the new HVMLC1 assay offers a sensitive diagnosis of myocardial injury. It is characterized by a wide diagnostic time window. The similarity of the HVMLC1 and m-ASAT curves indicates that it may be used to estimate the extent of myocardial necrosis.

Adult↗

PubMed1994

Human milk as a source of methylmercury exposure in infants.

As methylmercury is excreted in human milk and infants are particularly susceptible to toxicity due to this compound, the purpose of this study was to evaluate the possible transfer of methylmercury to infants via breast-feeding. In a community with a high intake of seafood, 583 children from a birth cohort were followed. The duration of nursing was recorded, and hair samples were obtained for mercury analysis at approximately 12 months of age. The hair mercury concentrations increased with the length of the nursing period, and those nursed throughout the first year showed the highest geometric mean (9.0 nmol/g or 1.8 microg/g). Human milk therefore seems to be an important source of methylmercury exposure in infants. An increasing time interval from weaning to hair sample collection was not associated with any detectable decrease in mercury concentrations. A slow or absent elimination of methylmercury during the first year after birth could explain this finding. In certain fishing communities, infants nursed for long periods may be at increased risk of developing methylmercury toxicity.

Cohort Studies↗

PubMed1993

[Assessment of risk in patients admitted for observation for suspected acute myocardial infarction based on a sensitive immunoanalysis of serum creatine kinase isoenzyme MB].

We evaluated a new sensitive creatine kinase (CK) isoenzyme MB immunoassay with regard to clinical applicability and clinical outcome in 156 patients admitted consecutively to the Coronary Care Unit and suspected of having acute myocardial infarction (AMI). Sixty-five patients (42%) had AMI based on WHO criteria; 65 (42%) had ischemic heart disease (IHD) without AMI, and 26 (16%) had non-IHD. The 65 IHD-patients without AMI could be subdivided into a group of 24 patients with significant changes in serum CK MB levels and 41 patients with stable serum CK MB levels as compared to the non-IHD group. The cumulative cardiac survival after 2 1/2 year (i.e. not suffering cardiac death) was 95 +/- 3% for patients with stable CK MB levels; for those with changes in CK MB levels it was 66 +/- 10% (p < 0.003). It was 52 +/- 6% for the patients with AMI, similar to patients with changes in CK MB levels (p = 0.15). We conclude, that this new CK MB assay can, in patients with IHD without AMI, detect a sub-group, representing one-third of the patients in this group, which is not diagnosed using routine diagnostic procedures. These patients are characterized by a poor clinical outcome, similar to patients with definite AMI.

Adult↗

PubMed1993

A programme for assigning target values for external quality assessment schemes in countries with no authorized reference laboratories. Annex. Experiences with deviating results on Ektachem 700 XR.

The use of consensus values in external quality assessment schemes (EQAS) involves several problems and should preferably be replaced with target values obtained by methods of high metrological level. However, such values are difficult to obtain. In the present study we transferred values from the NIST (former NBS) certified reference serum SRM 909 to lyophilized and frozen test sera for various inorganic components using flame absorption or flame emission spectrometry. Enzyme values were assigned by laboratories of members of the former Scandinavian Enzyme Committee. The assignment was based on 2-4 determinations each day through 3 days of experiment. A total of 10 laboratories participated in the work. The results were utilized in a Danish EQAS. One practical concern is the fairly long time (9 months) which was needed for production, collection and compiling all data. To get an impression of how much dry chemistry analysers, e.g, could influence consensus values a Kodak Ektachem 700 XR was studied using lyophilized and frozen sera. The results are reported in the annex. On NIST SRM 909 the values found for sodium(I) were 6% too high even though the findings on frozen human sera were accurate. For aspartate aminotransferase a result three times the target values was found on a human lyophilized serum, while the values on the frozen sera only were slightly too high.

Blood↗

PubMed1993

A quality manual for the clinical laboratory including the elements of a quality system. Proposed guidelines.

Development of quality manuals is a means for the promotion of quality in clinical laboratories by describing the total quality system. It also provides opportunity of checking whether the quality system is implemented in reality and demonstrates to the hospital administration and the clinicians that the laboratory is committed to quality. The intention of these guidelines is to describe the elements of the quality system for a large clinical laboratory, and to present such a system in the form of a quality manual. The proposed guidelines comply, where relevant, with ISO/IEC guide 25 'General requirements for the technical competence of testing laboratories' and EN 45001 'General criteria for the operation of testing laboratories'. The document may be used as an aid for laboratories wishing to be accredited according to EN 45001, or intending to apply for formal certification of their quality systems, according to ISO 9001 'Quality systems--Model for quality assurance in design/development, production, installation, and servicing' utilizing ISO 9004 'Quality management and quality system elements--guidelines; Part 2 Guidelines for service'. However, information about the minimum requirements for official recognition should be obtained from the particular accreditation or certification body concerned.

Chemistry, Clinical↗

PubMed1992

[Quality assurance of results of clinical chemical analyses in Danish hospital laboratories].

During the past 35 years, voluntary professional assessment of quality of the results of analyses in Danish hospital laboratories has been undertaken under the auspices of the Danish Society of Clinical Chemistry. The analytical quality of the laboratories is described by their "imprecision" and "accuracy" as expressed by "coefficient of variation" and "bias", respectively. The participation in these programmes was 90%. During the period between 1968 and 1987, inter-laboratory variation decreased markedly where all analyses were concerned. To ensure the necessary and adequate quality, establishment of specifications of quality based on clinical/biological goals of quality has proved necessary. The commonest reasons for large imprecision and bias from the target values are less specific methods of analysis, errors in calibration and sporadic "outliers". As the result of a stable organisation for ensuring quality, Denmark is well equipped for the introduction of the great demands in documentation of quality which may be anticipated from the Common Market during the immediate future.

Chemistry Techniques, Analytical↗

PubMed1992

Reference intervals for trace elements in blood: significance of risk factors.

A random sample of 100 men and 100 women was examined for whole-blood concentrations of mercury, lead, cadmium and selenium, and the serum concentrations of selenium, nickel, fluoride, aluminium, zinc and copper. Major predictors were sex, hormonal factors (pregnancy, menopause, use of oral contraceptives), age, tobacco smoking and alcohol drinking. Among notable associations, increased blood-mercury was related to the presence of more than four amalgam fillings in the teeth. Blood-mercury correlated with blood-selenium, but a relation to fish intake could only be demonstrated for the former parameter. In women, blood-lead appeared to increase with age, with the highest levels seen after the menopause. Serum-nickel was slightly lower in patients with nickel-related contact eczema. Only the selenium concentrations showed a slight increase in individuals taking mineral supplements. Serum-zinc concentrations decreased considerably during the day. Thus, due to the substantial influence of physiological and environmental factors, individual results must be interpreted in the light of the known predictors for the trace element concentration. However, population-based reference intervals for trace elements in blood are useful to explore geographic and temporal variations.

Adult↗