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Biomedical subjects

G Lindström

Publications and source records attributed to G Lindström.

At least 19 recordsLinked to original sources
PubMed2004

Modelling diffuse nutrient flow in eutrophication control scenarios.

The Swedish Water Management Research Programme (VASTRA) focuses on the development and demonstration of tools for more efficient eutrophication control when implementing the EU water framework directive in Sweden. During the first half of the programme, models for nitrogen flow were developed, and at present, similar models for phosphorus are under construction (e.g. HBV-P). The programme is interdisciplinary, and scientists are collaborating in actor-games and focus group evaluations including scenario analysis. The scenarios modelled in VASTRA phase I, show that (i) changed agricultural practices can be the most effective and least expensive way to reduce nitrogen transport from land to the sea; (ii) constructed agricultural wetlands may only have small impact on riverine nitrogen transport in some regions, due to natural hydrometeorological dynamics; (iii) removing planktivorous fish may be an efficient way of reducing the algal concentrations in lakes without the undesired side-effect of increased nutrient load to the down-stream river system. In VASTRA phase II, one of the highlights will be interdisciplinary scenario-modelling of different measure strategies in a pilot catchment of southern Sweden (Rönne å).

Agriculture↗
PubMed2002

Comparability of world-wide analytical data of PCDDs, PCDFs and non-ortho PCBs in samples of chicken, butter and salmon.

It was the primary objective of the present study to elucidate, from a chemical analytical point of view, the comparability of dioxin determinations and the consequences concerning the data on levels in food reported world-wide. To do so, an international intercalibration study on the determination of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and dioxin-like PCBs in three natural food items was performed between March and June 2000. Samples of chicken, butter and salmon, collected in Norway, where sent to 42 laboratories and analysed for 20 PCDDs/PCDFs/non-ortho PCBs. The study generated congener-specific data for the three food matrixes both on wet weight and lipid basis. The reported data from 37 laboratories, in 15 countries, were statistically analysed in order to determine the congener-specific comparability as well as the comparability based on a toxic equivalency value (TEQ). Based on the reported data the mean relative standard deviations (mean RSD) for the WHO98-TEQDFP measurements were found to range from 36% to 57% the three foods. For chicken, the consensus level was 1.2 ppt TEQ on lipid basis, and the reported levels by 24 laboratories were between 0.53 and 2.2 ppt. For butter, the consensus was 0.55 ppt TEQ. 27 laboratories reported levels from 0.18 up to 1.5 ppt. For the salmon, sample levels of 5.9 to 38 ppt TEQ (by 25 laboratories) was reported where 15 ppt was the consensus value. It can thus be concluded that the world-wide data on dioxins, at background levels in foods, are not direct numerically comparable due to inherent analytical reasons. Up to 50% deviations are expected when interlaboratory dioxin results for foods are compared.

Adult↗
PubMed2001

Adipose tissue concentrations of dioxins and dibenzofurans, titers of antibodies to Epstein-Barr virus early antigen and the risk for non-Hodgkin lymphoma.

A rapid increase in the incidence of non-Hodgkin lymphoma (NHL) has been reported in many countries. Exposure to certain pesticides or organochlorines has been shown to be a risk factor. Epstein-Barr virus (EBV) is a human herpesvirus that has been associated with some subgroups of NHL, such as Burkitt lymphoma and lymphomas related to severe immunosuppression. In this study we measured concentrations of dioxins and dibenzofurans in 33 NHL cases and 39 surgical controls. For 23 of the cases and 32 of the controls EBV titers were also available. Median titer of antibodies to EBV early antigen (EA) IgG was higher in patients than in controls. Concentrations of dioxins and dibenzofurans were divided into two groups according to the median concentration for the controls. Unconditional logistic regression analysis was performed adjusting for sex, age, and body mass index. For several higher chlorinated congeners increased risk was found for patients in the high-concentration and high-titer group. For toxic equivalency factor >27.79 and EA>80 an odds ratio of 2.8 with 95% confidence interval 0.52-18 was calculated. These results indicated that current exposure to certain organochlorines in combination with EBV might increase the risk for NHL.

Adipose Tissue↗
PubMed2001

Case-control study on concentrations of organohalogen compounds and titers of antibodies to Epstein-Barr virus antigens in the etiology of non-Hodgkin lymphoma.

A rapid increase in incidence of non-Hodgkin lymphoma (NHL) has been reported from many countries. Exposure to certain pesticides and organochlorines has been shown to be risk factors. Epstein-Barr virus (EBV) is a human herpesvirus that has been associated with some subgroups of NHL, such as Burkitt lymphoma and lymphomas related to severe immunosuppression. In this study, we measured lipid adjusted blood concentrations of 36 congeners of polychlorinated biphenyls (PCBs), p,p'-dichlorodiphenyl-dichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), four different subgroups of chlordanes (trans-nonachlordane, cis-nonachlordane, MC6 and oxychlordane) and 2,2',4,4'-tetrabrominated diphenyl ether (TBDE) in incident cases of NHL and controls from the general population. Titers of antibodies to the Epstein-Barr early antigen (EA) were correlated to concentrations of organochlorines. We found a significant difference in lipid adjusted blood concentrations of total PCBs and TBDE between cases and controls. Titers of antibodies to EA IgG > 80 were correlated to an increased risk for NHL with odds ratio (OR) = 1.9, 95% confidence interval (CI) =0.94-3.8. This risk was further increased in those with a level above the median value of "sum of PCBs" (OR=4.0, CI=1.2-14), HCB (OR=5.3, CI=1.6-19), sum of chlordanes (OR=4.0, CI=1.2-14) and TBDE (OR=21, CI=4.6-124), suggesting an interaction between EBV and a higher concentration of these chemicals. Also for the "sum of immunotoxic PCBs" increased risk was found in that group (OR=6.4, CI=1.9-24). Subdivision of NHL in histological types yielded highest risks for low-grade B-cell NHL.

Antibodies, Viral↗
PubMed2000

Concentrations of organochlorines related to titers to Epstein-Barr virus early antigen IgG as risk factors for hairy cell leukemia.

Hairy cell leukemia (HCL) is a rare chronic B-cell malignancy that, according to modern classifications, is a subgroup of non-Hodgkin lymphomas (NHLs). A rapid increase in incidence of NHL has been reported in many countries. The reasons for this increase are largely unknown, but exposure to organochlorines has been suggested as a risk factor. Epstein-Barr virus is a human herpesvirus that has been associated with certain subgroups of NHL. In this study, we measured lipid adjusted blood concentrations (in nanogram per gram) of 36 congeners of polychlorinated biphenyls (PCBs), p, p'-dichlorodiphenyldichloroethylene (p,p'-DDE), hexachlorobenzene (HCB), and four subgroups of chlordanes (trans-nonachlor, cis-nonachlor, MC6, and oxychlordane) in incident cases of HCL and controls from the general population. We obtained results on organochlorines and antibodies for 54 cases and 54 controls. Titers of antibodies to the Epstein-Barr early antigen and Epstein-Barr nuclear antigen, measured as P107, were correlated to concentrations of organochlorines to evaluate the possibility of an interaction between these factors in the pathogenesis of HCL. We found no significant difference in lipid-adjusted blood concentrations of total PCBs, p,p'-DDE, HCB, or the sum of the chlordanes between cases and controls. Titers of antibodies to Epstein-Barr early antigen IgG [Greater and equal to] 40 were correlated to an increased risk for HCL. This risk was further increased in those with a level above the median value of p,p'-DDE, HCB, or the sum of the chlordanes, suggesting an interaction between Epstein-Barr virus and a higher concentration of these chemicals. We also found increased risk for the sum of immunotoxic PCB group.

Antibodies, Viral↗
PubMed1999

Identification of 19 polybrominated diphenyl ethers (PBDEs) in long-finned pilot whale (Globicephala melas) from the Atlantic.

Nineteen tetra- to hexabrominated diphenyl ethers were identified at ppb concentration in the blubber of pilot whale caught off the coast of the Faroe Islands in 1994 and 1996. Higher total concentrations were found in the pooled samples of young males (3,160 ng/g lipid) and females (3,038 ng/g lipid) compared to adult females (843 ng/g and 1,048 ng/g lipid) and males (1,610 ng/g lipids). The predominant isomers in all samples were 2,2',4,4'-TeBDE (PBDE #47) and 2,2',4,4', 5-PeBDE (PBDE #99) accounting for some 70% of the sum of the 19 isomers.

Adipose Tissue↗
PubMed1999

Dioxin and dibenzofuran concentrations in blood of a general population from Tarragona, Spain.

The concentrations of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) were determined in plasma samples of 20 nonoccupationally exposed subjects living in the vicinity of a new hazardous waste incinerator (HWI), now under construction in Tarragona (Catalonia, Spain). The mean PCDD/F value was 27.0 pg I-TEQ/g lipid with a range from 14.8 to 48.9 pg I-TEQ/g lipid. All samples showed higher PCDD than PCDF levels. Although PCDD/F concentrations were higher in women (27.7 pg I-TEQ/g lipid) than in men (25.2 pg I-TEQ/g lipid), the difference was not statistically significant. While a significant correlation (r = 0.565, p < 0.01) between the age of the subjects and the levels of PCDD/F in plasma could be observed, no significant differences were found in relation to the specific residential area. The plasma concentrations of PCDD/F obtained in the current study are discussed and compared with the results of similar investigations reported in the last two years.

Adult↗
PubMed1999

Dioxin and dibenzofuran concentrations in adipose tissue of a general population from Tarragona, Spain.

Polychlorinated dibenzo-p-dioxin (PCDD) and polychlorinated dibenzofuran (PCDF) levels were determined in adipose tissue of 15 autopsied subjects who at the time of death had lived in the city of Tarragona (Catalonia, Spain) and surroundings during at least the last 10 years. PCDD/F concentrations ranged between 13.37 and 69.37 ng I-TEQ/kg fat, with mean and median values of 30.98 and 26.30 ng I-TEQ/kg fat, respectively. PCDD/F concentrations were higher (p < 0.01) in women (mean value: 44.95 ng I-TEQ/kg fat) than in men (mean value: 24.00 ng I-TEQ/kg fat). Although individuals living in industrial areas showed higher PCDD/F levels than those living Tarragona downtown the difference was not statistically significant. When Principal Component Analysis was applied to the concentrations of PCDD/Fs found in the 15 adipose tissue samples together with those found in 20 blood samples collected in a previous study, a single two-dimensional model was obtained, which would explain 62.9% of the variance in the data. The PCDD/F concentrations in adipose tissue found in the current study are of the same order of magnitude than those reported for most industrialized countries.

Adipose Tissue↗
PubMed1999

Polybrominated diphenyl ethers detected in human adipose tissue from Spain.

Polybrominated diphenyl ethers (PBDEs) were detected in 13 human adipose tissue samples from Spain, 3 women and 10 men. Tetra-, penta- and hexabrominated diphenyl ethers were determined at ng/g lipid (ppb) level in all the samples. The average TeBDE level was 1.36 ng/g, the average PeBDE was 0.93 ng/g and the HxBDE 1.83 ng/g. Human adipose tissue levels of PBDE obtained in the current samples from Spain are comparable with the tissue levels reported in recent Swedish investigations.

Adipose Tissue↗
PubMed1998

[Do flame retardants increase the risk of non-Hodgkin lymphoma? The levels of polybrominated diphenyl ethers are increasing in the environment].

Adipose tissue levels of tetra-BDE (2,2',4,4' tetra-brominated diphenyl ether) were measured in 42 male or female cancer patients [19 with non-Hodgkin's lymphoma (NHL), 23 with malignant melanoma (MM)], and in 27 controls without a diagnosis of cancer. As compared with tetra-BDE concentrations in controls, those in the MM subgroup did not differ, but those in the NHL subgroup were higher. Subgrouping of the cancer patients by occupational categories showed professional car, bus and truck drivers (at possible risk of exposure to PBDEs used as flame retardants in vehicle manufacture) to have higher tetra-BDE levels than controls, but not computer operators (at possible risk of exposure to PBDEs used in VDUs). Due to the small size of the series, however, the results may solely be regarded as hypothesis-generating, and further studies are needed.

Adult↗
PubMed1998

Some aspects of the etiology of non-Hodgkin's lymphoma.

In epidemiologic studies, non-Hodgkin's lymphoma (NHL) has been associated with exposure to chemicals such as phenoxyacetic acids; chlorophenols; dioxins; organic solvents including benzene, polychlorinated biphenyls, chlordanes; and immunosuppressive drugs. Experimental evidence and clinical observations indicate that these chemicals may impair the immune system. The risk is increased for NHL in persons with acquired and congenital immune deficiency as well as autoimmune disorders. Also, certain viruses have been suggested to be of etiologic significance for NHL. In some cases of NHL the common mechanism for all these agents and conditions may be immunosuppression, possibly in combination with viruses.

Dioxins↗
PubMed1998

Concentrations of the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether in human adipose tissue in Swedish persons and the risk for non-Hodgkin's lymphoma.

Concentrations of the flame retardant 2,2',4,4'-tetrabrominated diphenyl ether (2,2',4,4'-TeBDE) in the adipose tissue of 77 individuals from Sweden were determined. The subjects were recruited during the time period 1995-97 and encompassed both men and women ranging from 28 to 85 years in age. Of the subjects included, 19 patients had non-Hodgkin's lymphoma (NHL), 23 patients had malignant melanoma, 8 patients had other cancers or in situ changes, and 27 persons had no cancer diagnosis. The mean concentration of 2,2',4,4'-TeBDE was 5.1 ng/g lipid (range 0.6-27.5) for the 27 persons without malignancies. For NHL patients the mean concentration was 13.0 ng/g lipid (range 1.0-98.2). A nonsignificantly elevated risk with dose response was found for NHL when the cases and controls were compared in the two highest concentration groups (2.05-< 5.43 ng/g lipid and > or = 5.43 ng/g lipid) with the lowest group (< 2.05 ng/g lipid) yielding odds ratio (OR) 1.9 with 95% confidence interval (CI) 0.3-14 and OR 3.8, CI 0.7-26, respectively. The results for the patients with malignant melanoma did not differ from the controls.

Adipose Tissue↗
PubMed1998

Case-control study on breast cancer and adipose tissue concentrations of congener specific polychlorinated biphenyls, DDE and hexachlorobenzene.

In a case-control study on 43 patients operated for invasive breast cancer (cases) and 35 patients operated for benign breast disease (controls) adipose tissue concentrations of polychlorinated biphenyls (PCBs), 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE) and hexachlorobenzene (HCB) were investigated. Approximately 10 g of breast tissue free from tumour was taken and frozen until analysis. No significant difference for the sum of non co-planar PCBs or DDE was found between cases and controls. For postmenopausal women the odds ratio (OR) was increased for co-planar PCB #77 > 4.5 pg/g lipid (OR = 5.8, 95% confidence interval (CI) = 0.8-42), PCB #126 > 145 pg/g lipid (OR = 2.2, 95% CI = 0.2-18), PCB #169 > 90 pg/g lipid (OR = 7.8, 95% CI = 0.6-96), and for HCB > 40 ng/g lipid (OR = 1.9, 95% CI = 0.4-7.2) adjusted for age and parity. The risk increased further for postmenopausal women with oestrogen receptor positive tumours yielding for PCB #77 adjusted OR 33 (95% CI 1.8-588), PCB #126 OR not calculable (no unexposed cases), PCB #169 OR 8.6 (95% CI 0.5-136) and hexachlorobenzene OR 7.1 (95% CI 1.1-45). Also for the sum of PCB > 1230 ng/g lipid adjusted OR increased to 1.8 (95% CI 0.4-7.3) whereas the results were similar for DDE.

Adipose Tissue↗
PubMed1996

Increased concentrations of octachlorodibenzo-p-dioxin in cases with breast cancer--results from a case-control study.

Organochlorines are persistent and highly lipophilic environmental contaminants which bioaccumulate in the food chain. Some of these chemicals, 2,2-bis(p-chlorophenyl)-1,1,1-trichloroethane (DDT) and polychlorinated biphenyls (PCBs), have been suggested to be of significance in the aetiology of breast cancer. 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) is an anti-oestrogen in animal studies and should be thus lower the risk of breast cancer. The other isomers of polychlorinated dibenzo-p-dioxins (PCDDs) or the chemically related polychlorinated dibenzofurans (PCDFs) have not been tested regarding carcinogenesis of the breast. The purpose of this study was to investigate whether PCDDs or PCDFs influence the risk for breast cancer. Consecutive patients who underwent surgery for a breast disease between 1993 and 1995 were recruited for the study. Cases were 22 patients with infiltrative breast cancer and controls were 19 patients operated for a benign breast disease during the same time period. Approximately 10 g of breast tissue free from tumour was taken from the specimen and frozen until analysis. Fat was extracted, cleaned and analysed with a high-resolution gas chromatograph coupled to a high-resolution mass spectrometer. Median concentrations of octachlorinated dibenzo-p-dioxin (OCDD) were 598 (170-14,880) and 396 (103-1,847) pg/g lipid in the cases and in the controls, respectively. In a multivariate logistic regression analysis controlling for other risk factors for breast cancer increased odds ratio (OR) was obtained for OCDD: 401-1000 pg/g lipid yielded OR 3.8, 95% confidence interval (CI) 0.4-39, > 1000 pg/g lipid gave OR 5.2, CI 0.4-72. When the lipid OCDD variable was examined as a continuous risk factor there was a 1.09 (9%), CI 0.95-1.25, increase in the adjusted OR for breast cancer per 100 unit (pg/g lipid) increase in OCDD. No differences were found between cases and controls for the other six tested PCDDs. Mean concentration of TCDD was in the cases 3.6 (1.0-7.9) and in the controls 3.3 (1.1-6.3) pg/g lipid. For PCDFs no significant differences were found between cases and controls. The results were not changed if oestrogen or progesterone receptor status, S-phase fraction and DNA ploidy were considered. Breast tissue concentration of OCDD was increased in cancer patients, whereas the concentrations of other PCDDs and PCDFs were equal in cases and controls.

Adult↗
PubMed1995

Absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans by breast-fed infants.

The absorption of polychlorinated biphenyls, dibenzo-p-dioxins and dibenzofurans was studied in four breast-fed infants. The absorption was measured by comparing the estimated total intake and the excretion in faeces, during 48 hours, at three different time points; 1, 2 and 3 months post parta. The levels of the analysed compounds in the human milk are typical for Sweden, i.e approximately 20 ppt toxic equivalents for the dibenzo-p-dioxins and dibenzofurans and for the polychlorinated biphenyls approximately 16 ppt toxic equivalents. For most of the congeners the absorption is found to be over 95%. Higher excretion is noticed for heptachlorinated and octachlorinated dioxins.

Absorption↗
PubMed1995

Workshop on perinatal exposure to dioxin-like compounds. I. Summary.

An international workshop reviewed 20 ongoing or recently completed studies of the effects of perinatal exposures to dioxins, dibenzofurans, and PCBs on the reproductive, endocrine, neurodevelopmental, and immune systems. Many of the observed effects are consistent with these compounds acting as "environmental hormones" or endocrine disrupters. This report summarizes the conclusions and future directions described at the workshop.

Animals↗