Biomedical subjects

B Akesson

Publications and source records attributed to B Akesson.

At least 19 recordsLinked to original sources

PubMed1992

Fish as a source of exposure to mercury and selenium.

In a total of 395 subjects with varying fish consumption habits, mercury levels in whole blood (B-Hg), and selenium levels in plasma (P-Se) were studied. Also, in subcohorts, mercury levels in blood cells (Ery-Hg; n = 79), plasma (P-Hg; n = 158) and urine (U-Hg; n = 125) were analysed. There were statistically significant associations between fish intake on the one hand, and B-Hg, Ery-Hg and P-Hg, on the other, but not so with U-Hg. In subjects who never had fish, the average B-Hg was 1.8 ng/g, in subjects who had at least two fish meals each week, 6.7 ng/g. Ery-Hg, and to a less extent P-Hg, were associated with levels of marine n-3 polyunsaturated fatty acids (PUFA) in serum phosphatidylcholine. P-Hg and U-Hg were associated with numbers of teeth with amalgam fillings. P-Se also correlated with fish intake. In subjects who never had fish, P-Se averaged 80 micrograms/l, in subjects who had at least two fish meals per week, 91 micrograms/l. There was an association between PUFA and P-Se. Further, there were statistically significant associations between P-Se on the one hand, and B-Hg, Ery-Hg and P-Hg on the other. The data clearly demonstrate the importance of fish for the exposure to methylmercury and selenium in the Swedish diet, and the impact of amalgam as a source of exposure to inorganic mercury.

Adult↗

PubMed1992

Trace element status in healthy subjects switching from a mixed to a lactovegetarian diet for 12 mo.

The consequences of a change from a mixed to a lactovegetarian diet for 12 mo on trace element concentrations in plasma, hair, urine, and feces were studied in 16 women and 4 men. After the diet shift, intakes of zinc and magnesium did not change but that of selenium decreased by 40%. Three months after the diet shift, plasma and hair concentrations of zinc, copper, and selenium had decreased but those of magnesium had increased and the concentrations of mercury, lead, and cadmium in hair were lower. Also, the excretion of zinc, copper, and magnesium in urine, and that of selenium in urine and feces had decreased. Only small changes occurred during the remaining lactovegetarian-diet period. Three years later trace element concentrations had reverted towards baseline concentrations; copper values were similar to baseline concentrations but data for magnesium were slightly higher, and more complex patterns were observed for zinc and selenium. It is concluded that a shift to a lactovegetarian diet changes trace element status.

Adult↗

PubMed1992

Dietary intake and nutritional status in patients with systemic sclerosis.

Oesophageal dysmotility and abnormalities of intestinal function are important manifestations in systemic sclerosis and may have a significant effect on nutrient absorption and nutritional status. In this study 30 patients with systemic sclerosis with symptoms from the gastrointestinal tract were compared with matched healthy control subjects with respect to nutrient intake (four day record), anthropometric measurements, and biochemical nutritional status. The intake of energy (8.1 and 8.4 MJ/day) and its distribution among nutrients did not differ between patients and control subjects, but the lower intake of dietary fibre among patients with systemic sclerosis suggests that they avoided food with a coarse structure, such as coarse bread. The intake of vegetables and fruit also tended to be lower among patients with systemic sclerosis. Half of the patients had a subnormal arm muscle circumference, and two patients also had a subnormal triceps skinfold thickness, indicating severe malnutrition. The concentration of ascorbic acid, alpha-tocopherol, carotene, selenium, and also the proportion of linoleic acid (18:2) in serum phosphatidylcholine was lower in patients than in control subjects.

Adult↗

PubMed1992

Fatty acid composition of adipose tissue and serum micronutrients in relation to common rheumatic complaints in Swedish adults 50-70 years old.

Biochemical markers of nutritional status, such as adipose tissue fatty acid composition and circulating levels of micronutrients, may reflect dietary habits, but may also be related to inflammatory activity. We examined the relationship between common rheumatic complaints such as osteo-arthrosis, arthralgia, tendinitis, low-back pain, and neck pain, and the composition of adipose tissue fatty acids, serum concentrations of retinol, ascorbic acid, alpha-tocopherol and selenium in 502, out of 900 randomly selected individuals 50-70 years old. Compared with control subjects the rheumatic group as a whole (p less than 0.01) as well as subgroups like those with arthralgia (p less than 0.01), subacromial shoulder pain (p less than 0.03), and low-back pain (p less than 0.05), had decreased proportions of adipose tissue arachidonic acid. The abnormalities correlated with the duration of the symptom-free period preceding adipose tissue sampling and could not be explained by the evaluation of possible confounding factors. Regarding other fatty acids and micronutrients there were no differences between symptomatic subjects and controls. One explanation for the low proportion of adipose tissue arachidonic acid may be increased eicosanoid production.

Adipose Tissue↗

PubMed1992

Effect of six months of fish oil supplementation in stable rheumatoid arthritis. A double-blind, controlled study.

Therapeutic effects of fish oil (10 g/day) in rheumatoid arthritis were investigated in a randomized, controlled, double-blind study. Forty-three patients completing the study were evaluated at 0, 3 and 6 months. The nutrient intake in the fish oil group and in the control group was essentially similar. In the fish oil group, the percentage of n-3 fatty acids in serum phosphatidylcholine increased by 9.6 (range 2.6-16.1). Patients in the fish oil group reported a significantly decreased consumption of NSAID at 3 and 6 months, and the status of global arthritic activity improved at 3 months in physician's assessment. Control patients reported an increased global arthritic activity at 6 months. No change was found in patient assessment of pain, duration of morning stiffness or functional capacity. Essentially no change occurred in biochemical markers of inflammation. We conclude that fish oil has small anti-inflammatory effects with at most a NSAID-saving potential. The value of prolonged supplementation remains to be evaluated.

Adult↗

PubMed1992

Cancer incidence and mortality among Swedish Baltic Sea fishermen.

A 25% lower cancer mortality was found for 1360 Swedish fishermen who fished on the Baltic Sea than for the general population. The fishermen consumed twice as much fish as the population in the same county. In spite of the low overall cancer mortality, increased mortality from myeloma, as well as increased incidences of gastric carcinoma and squamous cell cancer of the skin and lips, was observed in the cohort. The decrease in risk for ischemic heart disease was not significant. Whether the dietary intake of fatty acids and selenium from fish contributed to the decreased risk was difficult to evaluate. Moreover, whether the consumption of fish from the Baltic Sea, contaminated with, for example, polychlorinated dioxins and dibenzofurans and other persistent organochlorine substances, contributed to the observed increased specific cancer risks is not known. However, the net health effect of high fish consumption from the Baltic Sea seems to be positive.

Adult↗

PubMed1992

The effects of a 2-year switch from a mixed to a lactovegetarian diet on trace element status in hypertensive subjects.

Trace element status of 20 hypertensive subjects (14 women and 6 men, mean age 52 years) was compared to that of normotensives. The changes in trace element status, body weight and blood pressure after a 2-year switch from a mixed to a lactovegetarian diet were also compared between these groups. The concentration of copper in plasma and that of lead in hair were higher in hypertensive subjects than in normotensives, but the concentrations of zinc, magnesium and selenium in plasma, urine and hair were similar to those of normotensives. In the hypertensive subjects, 3 months after the diet shift there was a decrease in the concentrations of zinc in plasma, hair and urine, that of copper in plasma and hair, of magnesium in urine, of selenium in plasma and hair, and an increase in the magnesium content in plasma and hair. Also the concentrations of mercury, lead and cadmium in hair decreased after the diet switch. Among the hypertensives, the relative increase of magnesium in plasma was greater than that of normotensives; their relative decreases of selenium and lead in hair were lower, that of cadmium greater and that of copper in urine was lower. Four years after the start of the experiment when most subjects had resumed a mixed diet, mineral and trace element concentrations in plasma, hair and urine were similar to their baseline levels. Three months after the diet switch the relative decrease in body weight was more marked among hypertensive women (5%) than in female normotensives (3%), but similar among men of both groups (5%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Nutrient intake and biochemical markers of nutritional status during long-term follow-up after total and partial gastrectomy.

Dietary intake and biochemical nutritional status was studied in patients who had undergone total gastrectomy (TG, n = 10) or partial gastrectomy (PG, n = 10) several years ago. The dietary intake of energy, macronutrients and micronutrients was very similar in the two groups and was also similar to the intake reported for healthy subjects in Sweden. The concentration of alpha-tocopherol in serum was subnormal in the TG group and that of carotene in both groups of patients, and the values were also significantly lower in the TG group than in the PG group. This was probably due to fat malabsorption, since dietary intake was found to be adequate. The proportions of n-6 and n-3 polyunsaturated fatty acids in serum phosphatidylcholine were not significantly different between the TG and PG groups. Iron deficiency was found in three patients in the TG group. Three patients (two TG, one PG) had elevated serum alkaline phosphatase and one patient (PG) had subnormal cobalamin concentration. For ascorbic acid, folate, calcium, phosphorus, magnesium, zinc, copper and selenium, the serum concentrations were normal or close to normal. Although the stores of some micronutrients seemed smaller after total gastrectomy, no major differences in nutritional status were found between the TG and PG groups. For the demonstration of decreased micronutrient stores during long-term follow-up after gastrectomy, an extended profile of biochemical markers of nutritional status is recommended.

Biomarkers↗

PubMed1991

Hydrolysis of chylomicron polyenoic fatty acid esters with lipoprotein lipase and hepatic lipase.

The lipolysis of rat chylomicron polyenoic fatty acid esters with bovine milk lipoprotein lipase and human hepatic lipase was examined in vitro. Chylomicrons obtained after feeding fish oil or soy bean oil emulsions were used as substrates. The lipolysis was followed by gas chromatography or by using chylomicrons containing radioactive fatty acids. Lipoprotein lipase hydrolyzed eicosapentaenoic (20:5) and arachidonic acid (20:4) esters at a slower rate than the C14-C18 acid esters. More 20:5 and 20:4 thus accumulated in remaining tri- and diacylglycerols. Eicosatrienoic, docosatrienoic and docosahexanoic acids exhibited an intermediate lipolysis pattern. When added together with lipoprotein lipase, hepatic lipase increased the rate of lipolysis of 20:5 and 20:4 esters of both tri- and diacylglycerols. Addition of NaCl (final concentration 1 M) during the course of lipolysis inhibited lipoprotein lipase as well as the enhancing effect of hepatic lipase on triacylglycerol lipolysis. Hepatic lipase however, hydrolyzed diacylglycerol that had already been formed. Chylomicron 20:4 and 20:5 esters thus exhibit a relative resistance to lipoprotein lipase. It is suggested that the tri- and diacylglycerol species containing these fatty acids may accumulate at the surface of the remnant particles and act as substrate for hepatic lipase during a concerted action of this enzyme and lipoprotein lipase.

Animals↗

PubMed1991

Exposure to dioxins and dibenzofurans through the consumption of fish.

BACKGROUND: In some regions, including the Baltic Sea, fatty fish such as salmon and herring contain high levels of polychlorinated dibenzodioxins and dibenzofurans. We investigated human exposure to these potentially toxic substances in relation to the consumption of fish from the Baltic Sea. METHODS: Plasma levels of 10 different dibenzofurans and 7 dioxins were analyzed in three groups of Swedish men: one group with a high intake of fish (fish eaten almost daily; n = 11), one with a moderate intake of fish (about once per week; n = 9), and one with no consumption of fish (usually because of allergy; n = 9). RESULTS: Plasma levels of several of the compounds we measured were higher in the men with a high intake of fish than in those who consumed moderate amounts, and the levels were higher in those who ate moderate amounts of fish than in those who ate none. The median amounts of the most toxic dioxin (2,3,7,8-tetrachlorodibenzo-p-dioxin) were 8.0 pg per gram of plasma lipid (range, 2.0 to 13) in the high-intake group, 2.6 pg per gram (range, 1.2 to 4.2) in the moderate-intake group, and 1.8 pg per gram (range, 1.0 to 2.5) in the nonconsumers (P = 0.001 and 0.02, respectively). There were consistent and statistically significant associations between the reported amount of fish eaten and the plasma levels of several of the dibenzofurans and dioxins. CONCLUSIONS: Contaminated fish such as those from the Baltic Sea are an important source of exposure to polychlorinated dibenzofurans and dibenzodioxins in persons who eat fish regularly. However, the clinical consequences of such exposure remain uncertain.

Adult↗

PubMed1991

Nutritional status after total and partial gastrectomy with Roux-en-Y reconstruction.

Dietary intake and nutritional status were studied in two groups of patients after total gastrectomy (n = 10) and after partial gastrectomy (n = 10). All patients were reconstructed with a Roux-en-Y loop. Investigations were carried out 4-17 years after the operation. Eight patients in the group undergoing total gastrectomy and four patients undergoing partial gastrectomy had gastric carcinoma and were without recurrent disease 5-15 years after the operation. A clinical dietician conducted an anthropometric evaluation. All patients underwent an upper gastrointestinal endoscopy, clinical examination, [14C]triolein breath test and a blood chemistry profile. The median weight loss from operation to investigation was 2.1 kg in the partial gastrectomy group and 6.7 kg in the total gastrectomy group (n.s.). After partial gastrectomy three patients had a subnormal body mass index (n.s.). This was not found in the total gastrectomy group. Energy intake was below that recommended in seven patients in the partial gastrectomy group (three of them had a subnormal body mass index) and in two in the total gastrectomy group (n.s.) [14C]triolein breath testing revealed fat malabsorption in three patients after partial gastrectomy and in five patients after total gastrectomy (n.s.).

Adult↗

PubMed1991

Experimental study on the metabolism of dimethylethylamine in man.

Dimethylethylamine (DMEA) is an aliphatic tertiary amine, which is used as a catalyst in the mould core manufacturing. During 8 h, four healthy volunteers were exposed to four different DMEA air concentrations (10, 20, 40 and 50 mg/m3; 20 mg/m3, two subjects only). DMEA was biotransformed into dimethylethylamine N-oxide (DMEAO). On average, DMEAO, accounted for 90% of the combined amount of DMEA and DMEAO excreted into the urine. The half-lives of DMEA and DMEAO in plasma were 1.3 and 3.0 h, respectively. The urinary excretion of DMEA and DMEAO followed a two-phase pattern. The half-lives in the first phase were 1.5 h for DMEA and 2.5 h for DMEAO. In the second phase, which started about 9 h after the end of exposure, half-lives of 7 h for DMEA and 8 h for DMEAO were recorded. The combined concentration of DMEA and DMEAO, in both plasma and urine, showed an excellent correlation with the air concentration of DMEA. Thus, both urinary excretion and plasma concentration can be used for biological monitoring of exposure to DMEA. An 8-h exposure to 10 mg DMEA/m3 corresponds to a postexposure plasma concentration and 2-h postexposure urinary excretion of 4.9 mumol/l and 75 mmol/mol creatinine, respectively.

Adult↗

PubMed1991

Fat-cell heat production, adipose tissue fatty acids, lipoprotein lipase activity and plasma lipoproteins in adiposis dolorosa.

1. Gluteal adipose tissue was examined in 13 patients with generalized adiposis dolorosa, a clinical condition characterized by painful adiposity with a chronic intractable course. The total metabolic activity of fat cells, isolated by collagenase and suspended in Krebs-Ringer bicarbonate buffer with glucose and insulin, was assessed by the measurement of heat production at 37 degrees C using microcalorimetry. 2. Fat cells were markedly enlarged; their metabolic activity expressed in terms of microW/g, but not in pW/cell, was significantly decreased when compared with both lean and weight-matched non-painful subjects. Both mean values were, however, significantly higher than in grossly obese subjects with similar mean cell size. Heat production as expressed per g of tissue, but not per cell, was inversely correlated with body mass index. One additional patient had unilateral disease, and fat cells from the painful side had a lower heat production than cells from the unaffected side. 3. The fatty acid composition of adipose tissue, as determined by g.c., revealed a significantly increased proportion of monounsaturated (18:1 and 16:1) at the expense of saturated (14:0 and 18:0) fatty acids compared with healthy control subjects. The activity of adipose tissue lipoprotein lipase was slightly, but not significantly, decreased. 4. It is concluded that a metabolic pathogenetic factor cannot be ruled out in adiposis dolorosa. As the results do not explain the nature of the diffuse pain, further studies need to be performed.

Adipose Tissue↗

PubMed1991

Visual disturbances in man as a result of experimental and occupational exposure to dimethylethylamine.

Experimental exposure of four volunteers to 40-50 mg/m3 of dimethylethylamine (DMEA) for eight hours caused irritation of the mucous membrane of their eyes, subjective visual disturbances (haze), and slight oedema of the corneal epithelium. The thickness of the cornea showed a slight but consistent increase in all four subjects at these exposures and in two subjects exposed to 10 mg/m3. Concentrations of 80 and 160 mg/m3 for 15 minutes caused eye irritation but no visual disturbances or corneal oedema. Occupational exposure for eight hours to about 25 mg/m3 of DMEA (with peaks above 100 mg/m3) was also associated with eye irritation, haze, and corneal oedema. The divergence between our findings and other reports in which visual disturbances occurred at lower concentrations during occupational exposure may be due to peak concentrations.

Adult↗

PubMed1991

Dimethylethylamine in mould core manufacturing: exposure, metabolism, and biological monitoring.

The exposure and metabolism of dimethylethylamine (DMEA) was studied in 12 mould core makers in four different foundries using the Ashland cold box technique. The mean time weighted average (TWA) full work shift DMEA exposure concentration was 3.7 mg/m3. Inhaled DMEA was excreted into urine as the original amine and as its metabolite dimethylethylamine-N-oxide (DMEAO). This metabolite made up a median of 87 (range 18-93) % of the sum of DMEA and DMEAO concentrations excreted into the urine. Occupational exposure did not significantly increase the urinary excretion of dimethylamine or methylethylamine. The data indicate half lives after the end of exposure for DMEA in urine of 1.5 hours and DMEAO of three hours. The postshift summed concentration of DMEA and DMEAO in plasma and urine is a good indicator of the TWA concentration in air during the workday, and might thus be used for biological monitoring. An air concentration of 10 mg/m3 corresponds to a urinary excretion of the summed amount of DMEA and DMEAO of 135 mmol/mol creatinine.

Adult↗

PubMed1991

Chromatography of selenoproteins in human serum using matrix-bound heparin.

Since previous experiments indicated that a major selenoprotein in human serum interacts with heparin, chromatography of serum on matrix-bound heparin was studied. When human serum was applied to heparin-agarose columns, approximately half of the applied selenium was not retained on the columns. Approx. 40% of the selenium could then be eluted either with increasing concentrations of heparin or ammonium acetate. Using a scaled-down version of this procedure, selenoproteins from 0.5 ml serum were separated into the heparin-binding and non-heparin-binding fractions. In an experiment where healthy subjects were given supplements of yeast selenium (200 micrograms/d) for eight weeks, the concentration of selenium in serum was almost doubled and then approached the original concentration 16 weeks after the end of the supplementation. During supplementation, no change in the concentration of heparin-binding selenoproteins was observed, and instead the increase in serum selenium occurred in non-heparin-binding proteins. This suggests that the need for selenium by the heparin-binding proteins was saturated already at the starting serum selenium level (1.0 mumol/l). Since interaction with heparin has been observed also for selenoprotein P isolated from rat plasma, the protein in the heparin-binding fraction, demonstrated in this paper, may be a human analogue to selenoprotein P.

Adult↗

PubMed1990

Controlled thermal degradation for the identification and quantification of amine N-oxides in urine.

Studies of amine N-oxides in urine are important for the evaluation of occupational exposure to amines. These thermolabile compounds are difficult to handle by either gas or liquid chromatography, so a device for controlled thermal degradation has therefore been developed. It consists of a short precolumn with shut-off valves at both ends and an aluminum block for heating, and it was connected to the injection port of a gas chromatograph. After injection of amine N-oxides onto the precolumn and thermal degradation, the degradation products were allowed to enter the analytical column. Trimethylamine N-oxide (TMAO) and triethylamine N-oxide (TEAO) were investigated. Their thermal degradation patterns could be used for identification and quantification in aqueous solutions and in urine. Linear calibration graphs based on degradation product peaks (trimethylamine and O,N,N-trimethylhydroxylamine from TMAO and diethylamine and triethylamine from TEAO) were obtained for concentrations up to 500 ppm. Detection limits in aqueous solutions were 0.2 ppm (ca. 1 ng) for TMAO and 1 ppm for TEAO and the precisions were 6% and 9%, respectively. In urine, similar values were obtained for TEAO. The detection limit for TEAO corresponds to the expected concentration in urine after an 8-h exposure to air containing 0.8 mg/m3 of triethylamine.

Amines↗

PubMed1990

Effects of human pancreatic lipase-colipase and carboxyl ester lipase on eicosapentaenoic and arachidonic acid ester bonds of triacylglycerols rich in fish oil fatty acids.

Fish oil chylomicrons, obtained from mesenteric duct chyle of rats fed [3H]20:5 and [14C]20:4 or [3H]20:5 and [14C]18:2 in a fish oil emulsion, were incubated with human pancreatic lipase-colipase, human carboxyl ester lipase (CEL) and human duodenal contents. With duodenal contents, the triacylglycerols labelled with [3H]20:5 and [14C]20:4 were rapidly converted to free fatty acids (FFA) and monoacylglycerols. Also during incubation with lipase-colipase the [3H]- and [14C]triacylglycerols disappeared completely and at equal rates, but in this case much [3H]20:5 and [14C]20:4 accumulated in diacylglycerols. When CEL was also added, the rate of disappearance of [3H]- and [14C]triacylglycerols increased and the radioactivity of diacylglycerols decreased markedly. During incubation of chylomicrons labelled with [3H]20:5 and [14C]18:2 with lipase-colipase, the rates of hydrolysis of [3H]- and [14C]triacylglycerols were similar, but more [3H]20:5 than [14C]18:2 accumulated in diacylglycerols. The accumulation of [3H]diacylglycerol was reduced by adding CEL. Also when fatty acids were analyzed by gas chromatography, 20:5 was enriched in remaining triacylglycerol and in diacylglycerol after incubation with lipase-colipase alone. The data thus indicate that both lipase-colipase and CEL participate in the hydrolysis of 20:5 and 20:4 ester bonds of dietary triacylglycerol.

Animals↗