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Biomedical subjects

L Hagmar

Publications and source records attributed to L Hagmar.

At least 73 records · Page 4Linked to original sources
PubMed1998

Polychlorinated biphenyls in blood plasma among Swedish female fish consumers in relation to low birth weight.

The authors examined the hypothesized association between the body burden of polychlorinated biphenyls (PCB) in women and the risk of low birth weight for their infants. In Sweden, a main exposure route for PCBs and other persistent organochlorine compounds is through the consumption of fatty fish from the Baltic Sea (on the Swedish east coast). A previous comparison between a cohort of consumers of large quantities of fish from the Swedish east coast and a reference population, together with a following analysis based on questionnaire data from a case-control study within the east coast cohort, supported the hypothesized association. In 1995, blood samples were collected from the wives and ex-wives of fishermen from the Swedish east coast (n = 192) who had given birth during the period 1973-1991. Cases (n = 57), i.e., infants with low birth weight (1,500-2,750 g), were matched with controls (n = 135; birth weight, 3,250-4,500 g) on gender, parity, and calendar year of birth. The concentration of 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in plasma was analyzed; it has been suggested that CB-153 is a relevant biomarker of exposure to PCBs. The concentration of CB-153 in the plasma of mothers during the year of childbirth was "estimated" using some alternative plausible kinetic models. For two alternative estimated exposure datasets, which were focused on separately, an increase in the risk of a low birth weight was observed at a CB-153 concentration of 300 and 400 ng/g lipid weight, respectively (adjusted odds ratios of 2.1 (95% confidence interval (CI) 1.0-4.7) and 2.3 (95% CI 0.9-5.9)). The present results strengthen the findings reported previously for this study population.

Adolescent↗
PubMed1998

Cancer predictive value of cytogenetic markers used in occupational health surveillance programs.

It has not previously been clear whether cytogenetic biomarkers in healthy subjects will predict cancer. Earlier analyses of a Nordic and an Italian cohort indicated predictivity for chromosomal aberrations (CAS) but not for sister chromatid exchanges (SCES). A pooled analysis of the updated cohorts, forming a joint study base of 5271 subjects, will now be performed, allowing a more solid evaluation. The importance of potential effect modifiers, such as gender, age at testing, and time since testing, will be evaluated using Poisson regression models. Two other potential effect modifiers, occupational exposures and smoking, will be assessed in a case-referent study within the study base.

Biomarkers↗
PubMed1998

Agreement between reported fish consumption obtained by two interviews and its impact on the results in a reproduction study.

In an ongoing study of the hypothesised association between consumption of fish contaminated with persistent organochlorine compounds and low birth weight, a relevant measure of exposure is the accumulated fish consumption over long time periods. An issue of concern in this study is the quality of the retrospective exposure assessments. The present investigation was undertaken to determine the agreement between reported fish consumption in two interviews with approximately one year in between. in order to evaluate its impact on the effect estimates. The agreement decreased with increasing retrospective time interval between interview and focused time period of fish consumption. Furthermore, the exposure assessments based on the two interviews led to considerably different effect estimates.

Adult↗
PubMed1998

Plasma levels of selenium, selenoprotein P and glutathione peroxidase and their correlations to fish intake and serum levels of thyrotropin and thyroid hormones: a study on Latvian fish consumers.

OBJECTIVE: To study the relationships between fish intake and different markers of selenium status and thyroid hormone function. DESIGN: Cross-sectional study. SETTING AND SUBJECTS: Sixty-eight men (age 24-79 years) were recruited among coastal fishermen and inland subjects from Latvia. None of the subjects was on selenium medication or had any known endocrine disease. MAIN OUTCOME MEASURES: Correlations between fish intake, plasma levels of selenium, selenoprotein P, glutathione peroxidase, organic mercury in erythrocytes and TSH in serum. RESULTS: Selenium in plasma ranged from 0.30 to 1.56 micromol/l, selenoprotein P from 0.54 to 2.21 arbitrary units relative to pooled plasma, and glutathione peroxidase from 1.20 to 5.73 mg/l. The number of fish meals per month was correlated with plasma selenium, selenoprotein P and glutathione peroxidase (r = 0.63, r = 0.62 and r = 0.50, respectively; P<0.001). Plasma selenium was correlated with selenoprotein P and glutathione peroxidase (r = 0.88 and r = 0.67, respectively; P < 0.001), and also selenoprotein P and glutathione peroxidase were correlated (r = 0.63, P < 0.001). The mean plasma selenium level in those with a high fish intake (21-50 fish meals/month), was 81% higher than in those with lowest fish intake. TSH in serum was inversely correlated with plasma selenium and selenoprotein P. Thyroid hormone levels were not correlated with plasma selenium, selenoproteins or fish intake. CONCLUSIONS: In this study group, selenium from fish intake had a marked impact on all variables studied on selenium status. No impact of selenium status on T3 and T4 levels was observed. The slightly negative correlation of selenium status with TSH levels might indicate a higher TSH secretion at low selenium status.

Adult↗
PubMed1998

Impact of exposure to insulation wool on lung function and cough in Swedish construction workers.

OBJECTIVES: To investigate whether application of insulation wool adversely affects lung volumes and increases the occurrence of symptoms of airway irritation. METHODS: Data from nationwide health check ups in 1981-93 of male construction workers born in 1955 or later were used to investigate cross sectional (n = 96,004) and longitudinal (n = 26,298) associations between lung volumes, vital capacity (VC), and forced expiratory volume in one second (FEV1) and exposure to insulation wool by combining a job exposure matrix (JEM) and self reported exposure. Data on 12 month prevalence of persistent cough not associated with the common cold was available for the period 1989-92. Potential confounding from smoking, exposure to asbestos, silica, and isocyanates, was considered in the analyses. RESULTS: For those in the highest exposure category (self reported duration of exposure of > or = 11 years, and high exposure according to the JEM) VC was on average 2.5 cl lower (95% CI -6.5 to 1.5) than in those with no exposure. The corresponding figures for FEV1 was -2.4 cl (95% CI -6.1 to 1.3). In the longitudinal analyses, the yearly change in VC between the first and last spirometry for those in the highest exposure category was 0.50 cl (95% CI -0.97 to 1.98) less than in the unexposed category. The corresponding figure for FEV1 was 0.89 cl (95% CI - 0.70 to 2.06). High exposure to insulation wool, asbestos, or silica, during the 12 months preceding the check up was associated with increased odds ratios (ORs) for persistent cough of the same magnitude as current smoking. CONCLUSIONS: The results indicate no effects on VC or FEV1 from exposure to insulation wool. Recent exposure to insulation wool, asbestos, and silica was associated with an increased prevalence of persistent cough.

Adult↗
PubMed1998

Postoperative prognosis in craniopharyngioma with respect to cardiovascular mortality, survival, and tumor recurrence.

Specific causes of death, survival, and recurrence rates were assessed in a cohort of 60 patients who had undergone surgery for craniopharyngioma between 1951 and 1988. Compared to the general population, the standardized mortality ratio (SMR) was increased [5.55; 95% confidence interval (CI), 3.68-8.22], and it was higher among females (SMR, 11.4) than males (SMR, 4.79). The risk of cardio- and cerebrovascular mortality (SMR, 3.21; 95% CI, 1.29-6.61) was also enhanced. The cumulative survival rates 10 and 15 yr after the initial operation were 68% (95% CI 54-78) and 59% (95% CI 30-63), respectively. A multivariate survival analysis adjusting for age showed a protective effect of radiotherapy (hazard ratio, 0.3; 95% CI, 0.1-0.8) and an increased risk of death after recurrence (hazard ratio, 4.4; 95% CI, 1.4-14), but no obvious effect of radicality at surgery. However, when patients who had died within 6 months after surgery were excluded, no significant protective effect of radiotherapy remained. The cumulative frequency of recurrence after 10 yr was 33% (95% CI, 22-48%), and that after 15 yr was 40% (95% CI, 28-56%). The incidence of recurrence did not differ significantly with respect to age, radicality at surgery, or postoperative radiotherapy. The determinants for long term outcome in patients with craniopharyngioma are interrelated in a complex way, which calls for strict selection criteria in follow-up studies and the use of multivariate statistical models.

Cardiovascular Diseases↗
PubMed1997

The impact of age, lactation and dietary habits on PCB in plasma in Swedish women.

The mean concentration of the chlorinated biphenyl 2,2',4,4',5,5'-hexachlorobiphenyl (CB-153) in plasma from 192 fishermen's wives from the Swedish east coast was on a fresh weight basis 960 (range 80-4300) pg/g and lipid adjusted 160 (range 20-780) ng/g lipid. The concentration of CB-153 in plasma was significantly influenced by age, total lactation time and place of living during childhood and adolescence (fishing village vs. other place). The residential variable probably reflects early life consumption of fish from the Baltic Sea (at the Swedish east coast) contaminated with persistent organochlorine compounds.

Adult↗
PubMed1997

Monitoring of polychlorinated biphenyls in human blood plasma: methodological developments and influence of age, lactation, and fish consumption.

Human plasma samples from 50 wives of fishermen have been analyzed with respect to PCBs. The non-ortho-substituted PCB congeners CB-126 and CB-169 were determined by mass spectrometry in negative ion chemical ionization mode, which demonstrated a limit of detection of 30 fg. The recoveries of the internal standards used for determination of ortho-substituted CBs were approximately 95%. Two methods, one gravimetric and the other based on enzymatic determinations of triglycerides, cholesterol and phospholipids, were compared for the determination of total amount of lipids in the plasma samples; the correlation coefficient was 0.82 and the slope 0.98. For practical reasons, enzymatic determinations are recommended for further use. The total, lipid-adjusted concentrations of PCBs in plasma were influenced by age, total lactation time and consumption of fatty fish from the Baltic Sea.

Adult↗
PubMed1997

Increased cerebrovascular mortality in patients with hypopituitarism.

OBJECTIVE: An increased prevalence of atherosclerosis has been shown among patients with hypopituitarism. The aim of the present study was to assess whether patients with hypopituitarism experience increased cardiovascular, in particular cerebrovascular, mortality. DESIGN AND PATIENTS: Retrospective cohort study of mortality, 1952-1992, in 344 patients, of whom 130 were female, receiving conventional hormone replacement for hypopituitarism following neurosurgery for pituitary tumours. The general population in the catchment area of southern Sweden from which the patients were recruited constituted the reference population. Expected mortality was obtained from cause, sex, calendar year, and 5-year age-specific death raise for the area. RESULTS: Increased mortality from cerebrovascular disease (standardized mortality ratio (SMR) 3.39; 95% CI 2.27-4.99) was the main contributor to the increased overall cardiovascular mortality (SMR 1.75; 95% CI 1.40-2.19). The increase in mortality from cardiac diseases was much smaller (SMR 1.41; 95% CI 1.04-1.88). The risk for cerebrovascular death was higher in women (SMR 4.91) than in men (SMR 2.64). The relative risk for cerebrovascular death was independent of the time interval since diagnosis of pituitary insufficiency, but was greater in subjects diagnosed at an earlier age (< 55 years). No increased mortality in malignant tumours was observed (SMR 0.95; 95% CI 0.60-1.48). CONCLUSION: The increased cerebrovascular mortality may be due to GH deficiency, or to long-term lack or inadequacy of substitution for other pituitary hormones. The observations that an early onset of pituitary insufficiency and female sex are predictors for a high risk for cerebrovascular mortality merit particular attention when treating this group of patients.

Adult↗
PubMed1997

Airway symptoms and lung function in pipelayers exposed to thermal degradation products from MDI-based polyurethane.

OBJECTIVES: To study the prevalence of symptoms from the eyes and the upper and lower respiratory tract, lung function, and immunological sensitisation towards isocyanates in pipelayers exposed to thermal degradation products from methylene diphenyl diisocyanate (MDI)-based polyurethane (PUR). MATERIAL AND METHODS: 50 presently active and 113 formerly active pipelayers were examined. Also, 65 unexposed workers were investigated for comparison. The one year prevalence of symptoms and smoking history (questionnaire data), lung function (vital capacity (VC) and forced expiratory volume in one second (FEV1), and atopy (positive skin prick tests towards standard allergens) were assessed among pipelayers and controls. For the pipelayers, the presence of work related symptoms and estimates of isocyanate and welding exposure were obtained from an interview. Skin prick tests towards specific isocyanate antigens and determinations of IgE-MDI and IgG-MDI in serum were also performed. RESULTS: The prevalence of episodes (more than once a month) of irritative eye symptoms, congestion of the nose, and soreness or dryness in the throat was much higher among the PUR pipelayers than among the controls. Most of the pipelayers with symptoms reported that these had started and occurred in relation to the PUR welding tasks. Presently active pipelayers with recent high PUR exposure showed a significant reduction of FEV1 compared with the controls. The estimated reduction, adjusted for smoking, was -0.3 l (P = 0.04). There was no confounding effect of ordinary welding. None of the pipelayers showed positive skin prick reactions against the specific isocyanate antigens used, or positive IgE-MDI, and only two had increased IgG-MDI. CONCLUSIONS: The findings indicate that exposure to thermal degradation products from MDI-based polyurethane has adverse effects on the mucous membranes and airways.

Adult↗
PubMed1997

Cumulative lead exposure in relation to mortality and lung cancer morbidity in a cohort of primary smelter workers.

OBJECTIVES: The purpose of this study was to determine the mortality and cancer incidence of long-term lead smelter workers at a primary smelter. METHODS: A cohort of 3979 workers employed for at least 1 year during 1928-1979 and a subcohort of 1992 workers employed in lead-exposed departments (lead only workers) was formed. The expected mortality in 1955-1987 and cancer incidence in 1958-1987 were calculated relative to the county rates, specified for cause, gender, 5-year age groups, and calendar year. A cumulative blood-lead index was used for the dose-response analyses. RESULTS: The lung cancer incidence of the total cohort [standardized incidence ratio (SIR) 2.8, 95% confidence interval (95% CI) 2.1-3.8] and the group with the highest exposure (SIR 3.1, 95% CI 2.0-4.6) was high. Similar risk estimates were observed with a latency of 15 years. The workers hired before 1950 had higher lung cancer risk estimates (SIR 3.6, 95% CI 2.6-5.0) than the workers hired later (SIR 1.3, 95% CI 0.6-2.6, no latency period). The risk estimates for lung cancer were further elevated in the subcohort of lead-only workers (SIR 5.1, 95% CI 2.0-10.5 in the highest exposed subgroup; latency period of 15 years). No excesses of other malignancies were noted. CONCLUSIONS: The increased relative risks were probably mainly due to interactions between lead and other carcinogenic exposures, including arsenic. Further study is required concerning such possible interactions before a role in the induction of lung cancer can be ascribed to lead.

Aged↗
PubMed1996

MDA in plasma as a biomarker of exposure to pyrolysed MDI-based polyurethane: correlations with estimated cumulative dose and genotype for N-acetylation.

The object of this study was to investigate whether exposure of pipe-layers to thermal degradation products of diphenylmethane diisocyanate (MDI) could be assessed by analysing 4,4-methylenedianiline (MDA) in hydrolysed plasma and urine, and whether the genotype for N-acetylation affected these biomarker levels. Blood and urine samples were drawn from 30-pipe-layers who had been welding polyurethane (PUR) insulated pipes during the preceding 3 months. MDA in hydrolysed plasma and urine was determined with a gas chromatography-mass spectrometry technique, and genotype for N-acetylation was analysed with a polymerase chain reaction technique. MDA in plasma was detected in 18 of the 30 pipe-layers. Their plasma concentrations of MDA varied from 0.05 to 8.48 micrograms/l. There was a significant negative correlation between time since last welding of PUR-insulated pipes and P-MDA (rs = 0.50, P = 0.005). There was also a significant positive correlation between the estimated number of welded PUR-insulated pipes during the preceding 3 months and P-MDA (rs = 0.68, P = < 0.001). No significant association between genotype of N-acetylation and P-MDA was observed in a multiple regression analysis when adjustment was made for the estimated cumulative exposure to thermal degradation products of MDI. MDA in urine was detected in only four of the 30 pipe-layers. These four subjects had been welding PUR pipes on the same day as the sampling, or on the day before. The present results indicate the spot plasma samples analysed for MDA may give a rather good estimate of exposure to MDI during the preceding months. P-MDA, but not U-MDA, therefore seems to be a useful biomarker of long-term exposure to MDI. The individual N-acetylation capacity did not affect the plasma levels of MDA.

Acetylation↗
PubMed1996

Toxicokinetics of 2,4- and 2,6-toluenediamine in hydrolysed urine and plasma after occupational exposure to 2,4- and 2,6- toluene diisocyanate.

OBJECTIVES: To assess the toxicokinetics of 2,4- and 2,6- toluenediisocyanate (TDI) in chronically exposed subjects. METHODS: Blood and urine, from 11 workers at two flexible foam polyurethane production plants, were sampled. By gas chromatography-mass spectrometry (GC-MS) 2,4- and 2,6-toluene diamine (TDA) were measured as pentafluoropropionic anhydride (PFPA) derivatives after acidic hydrolysis of plasma (P-TDA, ng/ml) and urine (U-TDA, microgram/h). RESULTS: In one of the plants the P-2,4-TDA concentrations were 0.4-1 ng/ml before a four to five week holiday and 0.2-0.5 ng/ml afterwards. The corresponding values for P-2,6-TDA were 2-6 and 0.5-2 ng/ml respectively. In the other plant the P-2,4-TDA concentrations were 2-23 ng/ml before the holiday and 0.5-6 ng/ml afterwards and the P-2,6-TDA concentrations were 7-24 ng/ml before and 3-6 ng/ml afterwards. The P-2,4-TDA concentrations were 2-24 ng/ml before a 12 day holiday, and 1-14 ng/ml afterwards. The corresponding values for P-2,6-TDA were 12-29 and 8-17 ng/ml, respectively. The urinary elimination rates (U-TDA, microgram/h) for 2,4-TDA before the holiday were 0.04-0.54 and 0.02-0.18 microgram/h afterwards. The corresponding values for 2,6-TDA were 0.18-0.76 microgram/h before and 0.09-0.27 microgram/h after the holiday. The half life in urine ranged between 5.8 and 11 days for 2,4- and 2,6-TDA. The differences in exposure were reflected by the P-TDA concentrations. The mean half life in plasma was 21 (range 14-34) days for 2,4-TDA and 21 (16-26) days for 2,6-TDA. The TDI air concentrations varied between 0.4 and 4 micrograms/m3 in one plant and in the other between 10 and 120 micrograms/m3. CONCLUSIONS: The half life in plasma of chronically exposed workers for 2,4-and 2,6-TDA was twice as long as for volunteers with short term exposure. An indication of a two phase elimination pattern in urine was found. The first phase was related to the more recent exposure and the second, much slower one was probably related to release of TDA in urine from TDI adducts in the body.

Air Pollution↗
PubMed1996

Cancer incidence and specific occupational exposures in the Swedish leather tanning industry: a cohort based case-control study.

OBJECTIVE: To study the effect on the incidence of cancer of exposure to chemicals handled in the leather tanning industry. MATERIALS AND METHODS: A case-control study was performed within a cohort of 2487 workers employed for at least six months during the period 1900-89 in three Swedish leather tanneries. 68 cancer cases (lung, stomach, bladder, kidney, nasal, and pancreatic cancers and soft tissue sarcomas) and 178 matched controls were studied. Effects of chemical exposures on cancer incidence, adjusted for age at risk, sex, and plant were estimated with a conditional logistic regression model. RESULTS: A significant association was found between exposure to leather dust and pancreatic cancer (odds ratio (OR) 7.19, 95% confidence interval (95% CI) 1.44 to 35-89). An association was indicated between leather dust from vegetable tanning and lung cancer. After adjustment for smoking habits a tentative association between organic solvents and lung cancer lost its significance. No association was found between exposure to chlorophenols and soft tissue sarcomas. CONCLUSIONS: The significant association between leather tanning and soft tissue sarcomas that was found in our previous cohort analysis could not be explained by exposure to chlorophenols. On the other hand a significant association was found between exposure to leather dust and pancreatic cancer, and exposure to leather dust from vegetable tanning was often present in cases with lung cancer. Due to the small numbers of cases, the results can, however, only lead to tentative conclusions.

Adult↗
PubMed1996

Dietary intake of fish contaminated with persistent organochlorine compounds in relation to low birthweight.

OBJECTIVES: The purpose of this study was to assess the hypothesized association between persistent organochlorine compounds through the consumption of fatty fish from the Baltic Sea (at the Swedish east coast) and low birthweight. MATERIALS AND METHODS: During the period 1973-1991, 72 cases of low birthweight (1500-2750 g) were selected from among infants born to fishermen's wives within a cohort from the Swedish east coast. For each case two referents were selected. The mothers were interviewed about their dietary and smoking habits and place of living during childhood and adolescence. RESULTS: A high total current intake of fish from the Baltic Sea (> or = 4 meals per month) tended to increase the risk of having an infant with low birthweight [adjusted odds ratio (OR) 1.9, 95% confidence interval (95% CI) 0.9-3.9]. The effect was more conspicuous for the boys (OR 3.4, 95% CI 1.1-11). No such effects were observed when the estimated intake of fish was considered for the period in which the infant was born. However, mothers who had grown up in a fishing village had an increased risk of having an infant with low birthweight (OR 2.1, 95% CI 1.0-4.3). CONCLUSIONS: The variable "grown up in a fishing village" can be interpreted as an indirect measure of a mother's accumulated consumption of fish from the Baltic Sea. This idea supports an association between a high consumption of contaminated fish from the Baltic Sea and an increased risk for low birthweight. The effect estimates based on the mothers' reported fish consumptions were dependent on the period under consideration and therefore were somewhat ambiguous.

Adult↗
PubMed1995

Functional aspects of developmental toxicity of polyhalogenated aromatic hydrocarbons in experimental animals and human infants.

A scientific evaluation was made of functional aspects of developmental toxicity of polychlorinated biphenyls (PCBs), polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) in experimental animals and in human infants. Persistent neurobehavioral, reproductive and endocrine alterations were observed in experimental animals, following in utero and lactational exposure to PCBs, PCDDs and PCDFs. The lowest observable adverse effect levels (LOAELs) for developmental neurobehavioral and reproduction endpoints, based on body burden of TCDD-toxic equivalents (TEQs) in animals, are within the range of current background human body burdens. Relatively subtle adverse effects on neurobehavioral development and thyroid hormone alterations have also been observed in infants and children exposed to background levels. Exclusive use of the toxic equivalency factor (TEF) approach may underestimate the risk of neurodevelopmental effects, because both Ah receptor dependent and independent mechanisms may be involved in these effects. The use of marker congeners and/or bioassays based on Ah receptor mediated mechanisms are rapid, low cost pre-screening alternatives for expensive and time consuming gas chromatographic-mass spectrometric analysis.

Animals↗
PubMed1995

Test chamber exposure of humans to 1,6-hexamethylene diisocyanate and isophorone diisocyanate.

An isocyanate generation apparatus was developed and stable isocyanate atmospheres were obtained. At a concentration of 5 micrograms 1,6-hexamethylene diisocyanate (HDI) per m3 the precision was found to be 7% (n = 5). Three volunteers were each exposed to three different concentrations of HDI (11.9, 20.5, and 22.1 micrograms/m3) and three concentrations of isophorone diisocyanate (IPDI) (12.1, 17.7, and 50.7 micrograms/m3), in an exposure chamber. The duration of the exposure was 2 h. Urine and blood samples were collected, and hydrolysed under alkaline conditions to the HDI and IPDI corresponding amines, 1,6-hexamethylene diamine (HDA) and isophorone diamine (IPDA), determined as their pentafluoropropionic anhydride amides (HDA-PFPA and IPDA-PFPA). The HDA- and IPDA-PFPA derivatives were analysed using liquid chromatography mass spectrometry with thermospray monitoring negative ions. When working up samples from the exposed persons without hydrolysis, no HDA or IPDA was seen. The average urinary excretion of the corresponding amine was 39% for HDI and 27% for IPDI. An association between the estimated inhaled dose and the total excreted amount was seen. The average urinary elimination half-time for HDA was 2.5 h and for IPDA, 2.8 h. The hydrolysis condition giving the highest yield of HDA and IPDA in urine was found to be hydrolysis with 3 M sodium hydroxide during 4 h. No HDA or IPDA could be found in hydrolysed plasma (< ca 0.1 micrograms/l).

Adult↗