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A Magnuson

Publications and source records attributed to A Magnuson.

18 recordsLinked to original sources
PubMed2006

Bridging-type changes facilitate successive oxidation steps at about 1 V in two binuclear manganese complexes--implications for photosynthetic water-oxidation.

The redox behavior of two synthetic manganese complexes illustrates a mechanistic aspect of importance for light-driven water oxidation in Photosystem II (PSII) and design of biomimetic systems (artificial photosynthesis). The coupling between changes in oxidation state and structural changes was investigated for two binuclear manganese complexes (1 and 2), which differ in the set of first sphere ligands to Mn (N(3)O(3) in 1, N(2)O(4) in 2). Both complexes were studied by electron paramagnetic resonance (EPR) and X-ray absorption spectroscopy (XAS) in three oxidation states which had been previously prepared either electro- or photochemically. The following bridging-type changes are suggested. In 1: Mn(II)-(mu-OR)(mu-OCO)(2)-Mn(II)<-->Mn(II)-(mu-OR)(mu-OCO)(2)-Mn(III)-->Mn(III)-(mu-OR)(mu-OCO)(mu-O)-Mn(III). In 2: Mn(II)-(mu-OR)(mu-OCO)(2)-Mn(III)<-->Mn(III)-(mu-OR)(mu-OCO)(2)-Mn(III)-->Mn(III)-(mu-OR)(mu-OCO)(mu-O)-Mn(IV). In both complexes, the first one-electron oxidation proceeds without bridging-type change, but involves a redox-potential increase by 0.5-1V. The second one-electron oxidation likely is coupled to mu-oxo-bridge (or mu-OH) formation which seems to counteract a further potential increase. In both complexes, mu-O(H) bridge formation is associated with a redox transition proceeding at approximately 1V, but the mu-O(H) bridge is observed at the Mn(2)(III,III) level in 1 and at the Mn(III,IV) level in 2, demonstrating modulation of the redox behavior by the terminal ligands. It is proposed that also in PSII bridging-type changes facilitate successive oxidation steps at approximately the same potential.

Electrochemistry↗
PubMed2005

Normal values and differences between intraperitoneal and subcutaneous microdialysis in patients after non-complicated gastrointestinal surgery.

OBJECTIVE: Visceral ischemia is an early event in the development of shock and organ failure. Microdialysis has been presented as a promising method for detection of visceral hypoxia and ischemia. The aim of this study was to investigate differences in the metabolic response measured by microdialysis between intraperitoneal and subcutaneous locations and to estimate normal values of lactate/pyruvate ratio, glucose and glycerol. MATERIAL AND METHODS: Intraperitoneal and subcutaneous metabolic responses were compared regarding lacate/pyruvate ratio, glucose and glycerol, during 45 postoperative hours in 33 patients undergoing various non-complicated elective major gastrointestinal surgery. RESULTS: Intraperitoneal lactate/pyruvate ratio started around 15 and decreased over time, while subcutaneous levels were stable around 9. Glucose levels were higher intraperitoneally and increased rapidly during the first 9 h to 8.6 mM, while the subcutaneous levels increased during 21 h to 7.5 mM. Intraperitoneal glycerol levels were stable around 100 microM, while subcutaneous values started around 230 microM and then increased. CONCLUSIONS: In a non-complicated postoperative course the lactate/pyruvate ratio and glucose levels are higher intraperitoneally, suggesting a higher postoperative intraperitoneal metabolism. Glycerol levels are higher and increase subcutaneously, suggesting increased postoperative energy demand, particularly in the visceral organs, as being responsible for the lipolysis seen in the subcutaneous tissue.

Adult↗
PubMed2004

Results of intraperitoneal microdialysis depend on the location of the catheter.

BACKGROUND AND OBJECTIVE: Intraperitoneal microdialysis was recently described as a method for early detection of visceral ischemia. The method seems safe and accurate. The intra-abdominal catheter used may imply variations in results depending on the location of the catheter. The aim of the study was to investigate possible differences in metabolic parameters obtained depending on various locations of the intra-abdominal catheter, compared with using the subcutaneous reference catheter. METHOD: After right-sided hemicolectomy in 12 patients, three catheters were placed and fixed intraperitoneally: one at the anastomosis, one in the omentum and one embedded between the small intestinal loops. A subcutaneous catheter placed in the pectoral region was used as reference. Analyses of lactate/pyruvate ratio and glucose and glycerol levels were done during a period of 45 hours postoperatively. RESULTS: Lactate/pyruvate ratio decreased numerically at all three intraperitoneal locations during the study while the subcutaneous lactate/pyruvate ratio increased slightly. Significant differences between intraperitoneal and subcutaneous locations were found as well as differences between the three intraperitoneal locations. Highest values of the lactate/pyruvate ratio were found at the anastomosis, while the widest range was found at the small intestine. Subcutaneous glucose levels were lower while glycerol levels were higher compared with intraperitoneal values. CONCLUSIONS: In evaluating postoperative metabolism, intraperitoneal microdialysis is influenced by the location of the microdialysis catheter. The same pattern is, however, recorded over time. The juxta-anastomotic region and the small intestinal loop area seem to be the most reasonable locations for measurements.

Aged↗
PubMed2004

Postoperative on-line monitoring with intraperitoneal microdialysis is a sensitive clinical method for measuring increased anaerobic metabolism that correlates to the cytokine response.

BACKGROUND: Visceral ischaemia and cytokine release are early stages in the development of shock and multiorgan failure. Because of lack of methods to measure anaerobic metabolism or visceral hypoxia in the early phase, diagnosis is not usually established until shock and organ failure are evident. METHODS: Nineteen patients were studied postoperatively after major abdominal gastrointestinal surgery. A microdialysis catheter was placed intraperitoneally before closure of the abdomen. Analysis of glucose, pyruvate and lactate was performed every second hour and the ratio between lactate and pyruvate was calculated. Peritoneal fluid was collected from a peritoneal drainage for analysis of tumour necrosis factor alpha (TNF-alpha) and interleukin 10 (IL-10). RESULTS: Sixteen of the patients had a normal postoperative course; the lactate/pyruvate ratio started at the level of 20 immediately postoperatively and decreased significantly during the first 45 postoperative hours (P = 0.007). A similar pattern was recorded for peritoneal TNF-alpha, which decreased correspondingly (P = 0.003). A correlation coefficient of 0.303 (P < 0.001 ) between lactate/pyruvate ratio and TNF-alpha was found. After an initial short increase, IL-10 decreased over time (P < 0.001). Three of the patients had abnormalities in the microdialysis results, cytokines and clinical outcome. These patients are presented separately. CONCLUSIONS: A normal postoperative course results in a decrease in the intraperitoneal lactate/pyruvate ratio, TNF-alpha and IL-10. A correlation between the intraperitoneal lactate/pyruvate ratio and TNF-alpha was found which suggests that intraperitoneal microdialysis is a sensitive, indirect method in analysing the postoperative intraperitoneal inflammatory response. A complicated postoperative course was preceded by increase of the peritoneal lactate/pyruvate ratio interpreted as splanchnic hypoxia and also an increased TNF-alpha level.

Adult↗
PubMed2004

Effect of sample aging on patient samples kept at ambient temperature before analysis with the Abbott Cell-Dyn 4000 hematology analyzer.

The effect of sample aging was studied on 80 blood samples collected from in-house patients within 2 hours before aspiration into the Cell-Dyn 4000 hematology analyzer. The first aspiration defined the zero-time value, and the samples were stored at ambient room temperature (23 degrees C) and reanalyzed at 12, 24, 48, 72, and 145 hours. Statistical analyses were made against the matched zero-time result for each patient. We report that the total white blood cell count is reliable for up to 24 hours, and that the 5-part differential count is reliable for up to 12 hours, being limited by the fragile eosinophils. This report shows that within 24 hours the neutrophil count, combined with the white cell count, is a more robust indicator of deviation of the main leukocyte subpopulation than the 5-part differential count. The platelet count was reliable for up to 12 hours. The erythrocyte mean cell volume (MCV) increased continuously during the observation period. In contrast, mean cell hemoglobin (MCH) showed a very small decrease after 72 hours. It is therefore proposed that MCH, and not MCV, should be used for diagnosis of the type of anemia.

Blood Cell Count↗
PubMed2002

Photo-induced oxidation of a dinuclear Mn(2)(II,II) complex to the Mn(2)(III,IV) state by inter- and intramolecular electron transfer to Ru(III)tris-bipyridine.

To model the structural and functional parts of the water oxidizing complex in Photosystem II, a dimeric manganese(II,II) complex (1) was linked to a ruthenium(II)tris-bipyridine (Ru(II)(bpy)(3)) complex via a substituted L-tyrosine, to form the trinuclear complex 2 [J. Inorg. Biochem. 78 (2000) 15]. Flash photolysis of 1 and Ru(II)(bpy)(3) in aqueous solution, in the presence of an electron acceptor, resulted in the stepwise extraction of three electrons by Ru(III)(bpy)(3) from the Mn(2)(II,II) dimer, which then attained the Mn(2)(III,IV) oxidation state. In a similar experiment with compound 2, the dinuclear Mn complex reduced the photo-oxidized Ru moiety via intramolecular electron transfer on each photochemical event. From EPR it was seen that 2 also reached the Mn(2)(III,IV) state. Our data indicate that oxidation from the Mn(2)(II,II) state proceeds stepwise via intermediate formation of Mn(2)(II,III) and Mn(2)(III,III). In the presence of water, cyclic voltammetry showed an additional anodic peak beyond Mn(2)(II,III/III,III) oxidation which was significantly lower than in neat acetonitrile. Assuming that this peak is due to oxidation to Mn(2)(III,IV), this suggests that water is essential for the formation of the Mn(2)(III,IV) oxidation state. Compound 2 is a structural mimic of the water oxidizing complex, in that it links a Mn complex via a tyrosine to a highly oxidizing photosensitizer. Complex 2 also mimics mechanistic aspects of Photosystem II, in that the electron transfer to the photosensitizer is fast and results in several electron extractions from the Mn moiety.

2,2'-Dipyridyl↗
PubMed2000

Towards an artificial model for Photosystem II: a manganese(II,II) dimer covalently linked to ruthenium(II) tris-bipyridine via a tyrosine derivative.

In order to model the individual electron transfer steps from the manganese cluster to the photooxidized sensitizer P680+ in Photosystem II (PS II) in green plants, the supramolecular complex 4 has been synthesized. In this complex, a ruthenium(II) tris-bipyridine type photosensitizer has been linked to a manganese(II) dimer via a substituted L-tyrosine, which bridges the manganese ions. The trinuclear complex 4 was characterized by electron paramagnetic resonance (EPR) and electrospray ionization mass spectrometry (ESI-MS). The excited state lifetime of the ruthenium tris-bipyridine moiety in 4 was found to be about 110 ns in acetonitrile. Using flash photolysis in the presence of an electron acceptor (methylviologen), it was demonstrated that in the supramolecular complex 4 an electron was transferred from the excited state of the ruthenium tris-bipyridine moiety to methylviologen, forming a methylviologen radical and a ruthenium(III) tris-bipyridine moiety. Next, the Ru(III) species retrieved the electron from the manganese(II/II) dimer in an intramolecular electron transfer reaction with a rate constant kET > 1.0 x 10(7) s(-1), generating a manganese(II/III) oxidation state and regenerating the ruthenium(II) photosensitizer. This is the first example of intramolecular electron transfer in a supramolecular complex, in which a manganese dimer is covalently linked to a photosensitizer via a tyrosine unit, in a process which mimics the electron transfer on the donor side of PS II.

2,2'-Dipyridyl↗
PubMed1999

The role of cytochrome b559 and tyrosineD in protection against photoinhibition during in vivo photoactivation of photosystem II

In vivo photoactivation of Photosystem II was studied in the FUD39 mutant strain of the green alga Chlamydomonas reinhardtii which lacks the 23 kDa protein subunit involved in water oxidation. Dark grown cells, devoid of oxygen evolution, were illuminated at 0.8 μE m-2s-1 light intensity which promotes optimal activation of oxygen evolution, or at 17 μE m-2s-1, where photoactivation compete with deleterious photodamage. The involvement of the two redox active cofactors tyrosineD and cytochrome b559 during the photoactivation process, was investigated by EPR spectroscopy. TyrosineD on the D2 reaction center protein functions as auxiliary electron donor to the primary donor P+680 during the first minutes of photoactivation at 0.8 μE m-2s-1 (compare with Rova et al., Biochemistry, 37 (1998) 11039-11045.). Here we show that also cytochrome b559 was rapidly oxidized during the first 10 min of photoactivation with a similar rate to tyrosineD. This implies that both cytochrome b559 and tyrosineD may function as auxiliary electron donors to P+680 and/or the oxidized tyrosine&z.ccirf;Z on the D1 protein, to avoid photoinhibition before successful photoactivation was accomplished. As the catalytic water-oxidation successively became activated, TyrosineD remained oxidized while cytochrome b559 became rereduced to the equilibrium level that was observed prior to photoactivation. At 17 μE m-2s-1 light intensity, where photoinhibition competes significantly with photoactivation, tyrosineD was very rapidly completely oxidized, after which the amount of oxidized tyrosineD decreased due to photoinhibition. In contrast, cytochrome b559 became reduced during the first 2 min of photoactivation at 17 μE m-2s-1. After this, it was reoxidized, returning to the equilibrium level within 10 min. Thus, during in vivo photoactivation in high-light cytochrome b559 serves two functions. Initially, it probably oxidizes the reduced primary acceptor pheophytin, thereby relieving the acceptor side of reductive pressure, and later on it serves as auxiliary electron donor, preventing donor-side photoinhibition.

Journal Article↗
PubMed1999

The relationship of arsenic levels in drinking water and the prevalence rate of skin lesions in Bangladesh.

To determine the relationship of arsenic-associated skin lesions and degree of arsenic exposure, a cross-sectional study was conducted in Bangladesh, where a large part of the population is exposed through drinking water. Four villages in Bangladesh were identified as mainly dependent on wells contaminated with arsenic. We interviewed and examined 1,481 subjects [Greater/equal to] 30 years of age in these villages. A total of 430 subjects had skin lesions (keratosis, hyperpigmentation, or hypopigmentation). Individual exposure assessment could only be estimated by present levels and in terms of a dose index, i.e., arsenic levels divided by individual body weight. Arsenic water concentrations ranged from 10 to 2,040 microg/L, and the crude overall prevalence rate for skin lesions was 29/100. After age adjustment to the world population the prevalence rate was 30. 1/100 and 26.5/100 for males and females, respectively. There was a significant trend for the prevalence rate both in relation to exposure levels and to dose index (p < 0.05), regardless of sex. This study shows a higher prevalence rate of arsenic skin lesions in males than females, with clear dose-response relationship. The overall high prevalence rate in the studied villages is an alarming sign of arsenic exposure and requires an urgent remedy.

Adult↗
PubMed1998

Coupled activation of the donor and the acceptor side of photosystem II during photoactivation of the oxygen evolving cluster.

Photoactivation of photosystem II has been studied in the FUD 39 mutant of Chlamydomonas reinhardtii that lacks the 23 kDa extrinsic subunit of photosystem II. We have taken advantage of the slow photoactivation rate of FUD 39, earlier demonstrated in Rova, E. M., et al. [(1996) J. Biol. Chem. 271, 28918-28924], to study events in photosystem II during intermediate stages of the process. By measuring the EPR multiline signal, the decay of the variable fluorescence after single flashes, and electron transfer from water to the QB site, we found a good correlation between the building of a tetrameric Mn cluster, longer recombination times between QA- and the donor side of photosystem II, and the achievement of water splitting ability. An increased rate of electron transfer from QA- to the QB site on the acceptor side of photosystem II, mainly due to enhanced efficiency of binding of QB to its site, was found to precede the building of the Mn cluster. We also showed that TyrD was oxidized simultaneously with this increase in electron-transfer rate. Thus, it appears that photoactivation is sequential, with an increased rate of electron transfer on the acceptor side occurring together with the oxidation of TyrD in the first step, followed by the assembly of the Mn cluster. We suggest that a conformational change of photosystem II is induced early in the photoactivation process facilitating electron transfer from the primary donor to the acceptor side. As a consequence, TyrD, an auxiliary electron donor to P680+/TyrZ*, is oxidized. That this occurs before the Mn cluster is fully functional serves to protect photosystem II against donor side induced photodamage.

Animals↗
PubMed1998

Oral snuff, smoking habits and alcohol consumption in relation to oral cancer in a Swedish case-control study.

The use of oral snuff is a widespread habit in Sweden. We investigated whether the use of Swedish moist snuff leads to an increasing risk of oral cancer. Other risk factors such as smoking tobacco and alcoholic beverages were also investigated. Our study comprised 410 patients with oral cancer, from the period 1980-1989, and 410 matched controls. All subjects received a mailed questionnaire. The response rates were 96% and 91% for cases and controls, respectively. In the study, a total of 20% of all subjects, cases and controls, were active or ex-snuff users. The univariate analysis did not show any increased risk [odds ratio (OR) 0.7, 95% confidence interval (CI) 0.4-1.1] for active snuff users. We found an increased risk (OR 1.8, CI 1.1-2.7) for oral cancer among active smokers. Alcohol consumption showed the strongest risk for oral cancer. Among consumers of beer, an increased risk of 1.9 (CI 0.9-3.9) was found. Corresponding ORs for wine and liquor were 1.3 (CI 0.9-1.8) and 1.6 (CI 1.1-2.3), respectively. A dose-response effect was observed. Although not statistically significant, a multivariate analysis similarly suggested that the most important risk factors were beer and liquor consumption, followed by smoking.

Age Factors↗
PubMed1998

Occupational exposures, animal exposure and smoking as risk factors for hairy cell leukaemia evaluated in a case-control study.

To evaluate occupational exposures as risk factors for hairy cell leukaemia (HCL), a population-based case-control study on 121 male HCL patients and 484 controls matched for age and sex was conducted. Elevated odds ratio (OR) was found for exposure to farm animals in general: OR 2.0, 95% confidence interval (CI) 1.2-3.2. The ORs were elevated for exposure to cattle, horse, hog, poultry and sheep. Exposure to herbicides (OR 2.9, CI 1.4-5.9), insecticides (OR 2.0, CI 1.1-3.5), fungicides (OR 3.8, CI 1.4-9.9) and impregnating agents (OR 2.4, CI 1.3-4.6) also showed increased risk. Certain findings suggested that recall bias may have affected the results for farm animals, herbicides and insecticides. Exposure to organic solvents yielded elevated risk (OR 1.5, CI 0.99-2.3), as did exposure to exhaust fumes (OR 2.1, CI 1.3-3.3). In an additional multivariate model, the ORs remained elevated for all these exposures with the exception of insecticides. We found a reduced risk for smokers with OR 0.6 (CI 0.4-1.1) because of an effect among non-farmers.

Adult↗
PubMed1998

Oral infections and dental factors in relation to oral cancer: a Swedish case--control study.

We investigated the role of oral infections, dentition and dental X-rays for oral cancer in a north Swedish population. This case-control study consisted of 410 cases with oral cancer for the period 1980-89 and 410 matched controls. All subjects received a mailed questionnaire. The response rates were 96% and 91% for cases and controls, respectively. The univariate analysis showed a statistically significant increased risk for oral cancer among individuals reporting problems with recurrent clinical oral infection (odds ratio (OR) 3.8). Separate analyses were made for groups with a clearly stated HSV-1 infection (OR 1.9) and highly suspected HSV-1 infection (OR 3.3) as reported by the subjects. Odds ratios were also calculated for infections in relation to tobacco and alcohol habits. For individuals reporting recurrent infection problems an increased risk was observed in every combination category. Dental factors such as different fillings, dentures and fixed prostheses showed no increased risks. Dental X-ray did not produce an increased OR either. A multivariate analysis suggested that the most important risk factors were oral infections followed by liquor consumption and active smoking.

Alcohol Drinking↗
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↗
PubMed1997

Different manganese binding sites in photosystem II probed by selective chemical modification of histidyl and carboxylic acid residues.

The binding of Mn2+ to manganese-depleted photosystem II was investigated after chemical modification of histidyl and carboxylic acid residues in the presence or absence of the native manganese cluster. K(M) values for Mn2+ were determined from steady-state electron transfer between Mn2+ and 2,6-dichlorophenolindophenol, the dissociation constant for Mn2+ was measured by observing the effect of added Mn2+ on the reduction of the primary donor P680+ after a saturating flash, and single-turnover electron donation from Mn2+ was followed by monitoring the decay kinetics of the EPR signal from the flash-induced tyrosine Zox radical. K(M) values for Mn2+ were found to be highly pH-dependent in both modified and unmodified photosystem II membranes. Treatment with histidine modifiers after removal of the manganese complex increased the K(M) values between 2.5 and 10 times and increased the dissociation constant for Mn2+ 8-fold, compared to membranes that were modified in the presence of the manganese cluster. Modification of carboxylic acid residues after removal of the manganese cluster increased the K(M) about 5-fold compared to membranes that were modified in the presence of the manganese cluster. The reduction rate of tyrosine Zox by Mn2+ was diminished after modification of either histidine or carboxylic acid residues. The apparent second-order rate constant decreased from 2.6 x 10(6) M(-1) s(-1) to 0.05 x 10(6) M(-1) s(-1) after histidine modification in the presence or absence of manganese, to 0.77 x 10(6) M(-1) s(-1) after carboxylic acid residue modification in the presence of manganese, and to 0.18 x 10(6) M(-1) s(-1) after carboxylic acid modification in the absence of manganese. Our results indicate the existence of two different manganese binding sites containing histidine, and at least two manganese sites with carboxylic acid residues, which are differently shielded against modifying agents by the native manganese cluster.

2,6-Dichloroindophenol↗
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↗
PubMedDate not supplied

Occupational exposures as risk factors for oral cancer evaluated in a Swedish case-control study.

In a case-control study with 410 cases and 410 matched controls from the period 1980-1989 we investigated the role of occupations and occupational exposures as risk factors for squamous cell oral cancer. All subjects received a questionnaire. The response rates were 96% and 91% for cases and controls, respectively. A significantly increased risk was found for pulp industry workers, odds ratio (OR) 4.0 and wood or product workers, OR 5.5. Exposure to chemicals such as phenoxyacetic acids yielded an OR of 1.7. The positive findings in this study may be explained by exposure to chemicals, but need to be verified in further studies.

Aged↗