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Biomedical subjects

B Bergström

Publications and source records attributed to B Bergström.

At least 19 recordsLinked to original sources
PubMed1996

A longitudinal study of resin-bonded prostheses.

Resin-bonded fixed partial dentures, without definitive tooth preparation and current resinous cements and perceptive treatment, have had an inordinate number of dislodgments in initial restorative efforts. A longitudinal examination of resin-bonded prostheses was performed after a mean observation time exceeding 6 years. To prevent stress fatigue fractures of the cement bondings, one proximal groove was prepared in dentin for each anterior abutment and the inner surfaces of the frameworks were silicoated. Five of 34 prostheses debonded, and the bond strength between resin and high gold alloys was too low to resist fatigue fractures during this study. The results of this study and other reports suggested a need for increased retention and resistance form of the frameworks to improve longevity of resin-bonded prostheses.

Adult↗
PubMed1995

Experimental evaluation of the effect of filtration of diesel exhaust by biologic exposure indicators.

The airway resistance, compliance of the respiratory system, transfer factor, and alveolar volume of 33 healthy rabbits were studied before and after exposure to diluted diesel exhaust generated in an experimental motor. Three diesel fuels and two particle traps were tested. Subsequent to the post-exposure lung function measurements, the animals were sacrificed and the lungs were processed for morphologic examination. The concentrations of particles, nitrogen dioxide, and formaldehyde were measured. The inflammatory airway changes were most pronounced in animals exposed to exhaust from standard fuel. Small changes were identified in animals exposed to exhaust filtered through the catalytic trap as well or exposed to unfiltered exhaust from fuels intended for densely built-up areas. Increase in compliance of the respiratory system was associated with the concentration of soot particles and formaldehyde. Compliance decreased significantly in animals exposed to exhaust from standard fuel filtered through the particle traps and increased almost significantly in animals exposed to unfiltered exhaust from the same fuel.

Air Pollutants↗
PubMed1995

Prospective study of autonomic nerve function in type 1 and type 2 diabetic patients: 24 hour heart rate variation and plasma motilin levels disturbed in parasympathetic neuropathy.

To clarify the impact of autonomic neuropathy in diabetic patients, we have conducted a prospective study of 58 Type 1 and 51 Type 2 diabetic patients (investigated at baseline, after 4, and after 7 years). In Type 1 diabetic patients, the sympathetic nerve function (orthostatic acceleration and brake indices) and in Type 2 patients, parasympathetic nerve function (R-R interval variation; E/l ratio) deteriorated during 7 years of prospective observation. Symptoms of autonomic neuropathy were associated with signs of autonomic neuropathy (low brake indices) in Type 1 but not in Type 2 diabetic patients. In the latest assessment 24 h ECG recording was performed and blood samples assayed for neuropeptide Y (NPY) and motilin were obtained. Type 1 diabetic patients with parasympathetic neuropathy (abnormal E/l ratio) showed significantly lower SD value (less variation in the R-R intervals; 29 [17] vs 50 [16], [mean (interquartile range)]; p = 0.001) and higher postprandial plasma motilin values (70 [20] pmol l-1 vs 50 [15] pmol l-1; p < 0.01) than patients with normal parasympathetic nerve function. In Type 2 diabetic patients, sympathetic neuropathy (low brake indices) was associated with an increased frequency of ventricular extra systolic beats during 24 h ECG recording (rs = 0.65; p < 0.01). Postprandial plasma NPY levels were not associated with disturbed autonomic nerve function.

Adolescent↗
PubMed1994

Maternal health and child survival in relation to socioeconomic factors.

The health of 280 rural Somali women of reproductive age was studied using a structured questionnaire, measuring weight, height, arm circumference and estimations of hemoglobin. Mean height and weight were 159 cm and 53 kg, respectively. 12.7% had a weight below 50 kg and 5.6% had a height below 150 cm. One third of the women had a body mass index of 19 indicating sub/malnutrition. Mean hemoglobin was 105 g/l. Every fourth woman had a hemoglobin level between 85 and 100, while every tenth had a value below 70 g/l. A higher hemoglobin level and better child survival rate were associated with the husband's reading ability, whether the household owned a farm, whether the woman had a second job, whether the woman possessed gold and the household's possession of a radio.

Adult↗
PubMed1994

Fertility, infertility and child survival of Somali women.

The relationship of reproductive patterns, some socio-economic factors and child survival was studied in 766 rural Somali women. A structured questionnaire was the method of data collection. Teenage marriage was the norm for the women, and divorce was very common. The mean number of live births was 5.2, and the mean number of surviving children was 3.7. 2/3 of the women aged 45+ had a parity of 6 or more, about one third had had at least one miscarriage and one fifth had experienced one stillbirth. Primary infertility was observed in 7% of the women aged 45+, while 20% were considered subfertile. Verbal autopsy showed that mortality was highest among infants and accounted for 63% of the child deaths. Major causes of death were neonatal tetanus, diarrhoea and respiratory diseases. Child survival and reproductive outcome ratios were found to be negatively related to the increasing age of the mother and parity. Divorce and widowhood were also found to be associated with low child survival.

Abortion, Spontaneous↗
PubMed1992

Lung function and precipitating antibodies in low exposed wood trimmers in Sweden.

Wood trimmers are exposed to molds that periodically grow on timber that may induce alveolitis and obstructive lung disease. We have evaluated respiratory symptoms, bronchial reactivity, and lung function in 28 wood trimmers at a Swedish sawmill and in 19 unexposed office workers. Eleven (sero-positive) of the wood trimmers had precipitating antibodies in peripheral blood against one or several molds. The exposure to dust (median 0.26 mg/m3), viable mold spores (median 2950 cfu/m3), viable bacteria (median 370 cfu/m3), airborne endotoxins (range 0.0015-0.0025 microgram/m3), and terpenes (range 0.4-23 mg/m3) was lower than levels that earlier have been reported to affect lung function. The wood trimmers reported an increased prevalence of cough and breathlessness. They also showed signs of a mild obstructive impairment with a tendency to increase bronchial sensitivity to metacholine and decreased FEV1 after 2 days free from exposure. FEV1 decreased more during the working week in the sero-positive workers than among the sero-negative workers, and for the whole group the decrease in FEV1 and MEF25 was correlated to the degree of mold exposure.

Adult↗
PubMed1992

Plasma neuropeptide Y (NPY) and galanin before and during exercise in type 1 diabetic patients with autonomic dysfunction.

Plasma neuropeptide Y (NPY), plasma galanin and plasma catecholamines were determined before and during an ergometer exercise test in 11 type 1 diabetic patients (age 19-36 years, mean 30; duration of diabetes 2-18 years, mean 9) with autonomic dysfunction and in 13 age-matched healthy controls (age 24-36 years, mean 29). Before exercise, plasma NPY (100 +/- 6 pmol/l vs 144 +/- 7 pmol/l; P less than 0.001) and plasma galanin (54 +/- 3 pmol/l vs 77 +/- 5 pmol/l; P less than 0.005) were significantly lower in patients than in controls. During exercise, plasma NPY, plasma adrenaline, and plasma noradrenaline increased in patients and controls while galanin only increased in patients. Since there was a direct correlation between plasma NPY before exercise and the increment (delta 80%) in noradrenaline during exercise (r = 0.54; P less than 0.01), it is suggested that plasma NPY determined in the basal situation may be a useful marker of sympathetic nerve failure in diabetic patients.

Adult↗
PubMed1992

Temporary health effects from exposure to water-borne paints.

Temporary health effects of exposure to experimental paints were studied. Ten painters feeling nuisance from water-borne paints and eight painters not feeling such nuisance applied eight experimental water-borne paints according to normal work routines. The effects were a decrease in forced vital capacity, forced expiratory volume in 1 s and peak expiratory flow, an increase in urine excretion, and a decrease in urine density. A small, but statistically highly significant, increase in the mean volume of erythrocytes was observed. The effects were similar in the two groups, but the "nuisance group" reacted with a larger urine excretion and a larger increase in the mean volume of erythrocytes. The effects did not influence physical work capacity. The effects on the lungs and urinary excretion were probably not associated with the organic solvents or ammonia in the paints. Instead, they were probably due to derivatives of isothiazolinone. This assumption needs verification.

Adult↗
PubMed1991

Pulmonary function in workers exposed to diesel exhausts: the effect of control measures.

To assess the protective effect of exhausts pipe filters or respirators on pulmonary function, 15 workers in a tunnel construction site, truck and loading machine drivers, rock workers, and others were studied. The total and respirable dust, combustible matter in respirable dust, carbon monoxide, nitrogen monoxide and nitrogen dioxide were measured for each subject during entire work shifts. The effect of the exposure on the lung function variables was measured by dynamic spirometry, carbon monoxide single breath technique, and nitrogen single breath wash-out. The exhaust pipe filtering had a protective effect, directly discernible in the drivers on vital capacity and FEV1.0 and for the whole group on FEV% and TLco. The dust respirators had no effect, probably because of the difficulties in correctly using personal protection under the circumstances in the tunnel. In the absence of a true exposure assessment, control measures for diesel exhausts can be tested by medical effect studies. Catalytic particle filters of diesel exhausts are one method of rendering the emissions less irritant, although they will not remove irritant gases. An indicator of diesel exhaust exposure should include the particle fraction of the diesel exhausts, but a discrimination between different sources of organic dust must be possible.

Adult↗
PubMed1991

Impeded lung function in moulders and coremakers handling furan resin sand.

A total of 39 moulders and coremakers exposed to furan resin sand and 27 unexposed local controls were examined by lung-function tests before and after a work shift. In all, 28 of the subjects exposed to furan resin sand and the control group were evaluated by dynamic spirometry and nitrogen washout. The remaining 11 subjects exposed to furan resin sand were studied using both static and dynamic spirometry and the CO single-breath technique. The time-weighted average exposure to furfuryl alcohol was about 7 mg/m3, with peak values exceeding the present Swedish short-term exposure limit (40 mg/m3). The exposure to respirable dust and formaldehyde as time-weighted over the shift was less than 2 mg/m3 and 0.4 mg/m3, respectively, in all groups. During the work shift studied, the 28 exposed subjects had more complaints of airway symptoms than did the controls, showing an average decrease of 0.21 in forced vital capacity but no fall in any other lung-function variable. The remaining 11 exposed subjects demonstrated a post-shift decrease in total lung capacity. The results indicate an acute restrictiveness induced by exposure to furan resin sand, but the underlying mechanism is unclear. Chronic impairment of lung function was not observed.

Adult↗
PubMed1991

Autonomic nerve antibodies and autonomic nerve function in type 1 and type 2 diabetic patients.

Complement-fixing adrenal medulla (CF-ADM), sympathetic ganglion (CF-SG), and vagal (CF-V) nerve antibodies were determined in diabetic patients. Among 74 patients with Type 1 diabetes, CF-ADM was detected in 7 (10%) cases, CF-SG in 14 (19%) cases, and CF-V in 8 (11%) cases. Among 38 patients with Type 2 diabetes, CF-ADM was detected in 5 (13%) cases, CF-SG in 4 (11%) cases, and CF-V in 6 (16%) cases. There were associations between autonomic nerve antibodies and autonomic nerve function. CF-ADM and/or CF-SG were significantly (P less than 0.002) less prevalent in Type 1 diabetic patients with autonomic neuropathy than in those without [5/44 (11%) vs. 14/30 (47%)] and, in agreement with this, the brake index, a sign of parasympathetic and sympathetic autonomic nerve function, was significantly (P less than 0.005) higher (more normal) in these patients (-0.56 +/- 0.13 vs. -1.04 +/- 0.12). In Type 2 diabetic patients, the E/I ratio, an index of parasympathetic nerve function, was significantly (P less than 0.03) lower (more abnormal) in those with CF-V than in those without (-1.81 +/- 0.17 vs. -1.20 +/- 0.11). In conclusion, the frequency of sympathetic nerve antibodies was decreased in Type 1 diabetic patients with autonomic neuropathy, while in Type 2 diabetic patients parasympathetic nerve antibodies were related to severe parasympathetic neuropathy.

Adrenal Medulla↗
PubMed1990

The activity of the renin-angiotensin-aldosterone system before and during submaximal bicycle exercise in relation to circulatory catecholamines in patients with type 1 (insulin-dependent) diabetes mellitus.

To evaluate the renin-angiotensin-aldosterone system in relation to circulatory catecholamines, we determined renin activity, angiotensin II, aldosterone, adrenaline, and noradrenaline in plasma before and during a submaximal bicycle exercise test in 23 Type 1 (insulin-dependent) diabetic patients (aged 19-57 years, mean 37; duration of diabetes 2-32 years, mean 16), 17 with signs of cardiac autonomic neuropathy, and in 18 healthy non-diabetic subjects (aged 24-41 years, mean 29). At rest, Type 1 diabetic patients showed significantly lower aldosterone values than control subjects (0.14 +/- 0.02 nmol/l and 0.22 +/- 0.02 nmol/l; p less than 0.01) while renin activity (1.0 +/- 0.1 nmol.l-1.h-1 and 0.9 +/- 0.1 nmol.l-1.h-1) and angiotensin II (14 +/- 1 nmol/l and 18 +/- 2 nmol/l) did not differ significantly between patients and control subjects. During exercise, increments (increase from the resting value to the value at 80% of maximal working capacity) in renin (1.5 +/- 0.4 nmol.l-1.h-1 and 3.7 +/- 0.5 nmol.l-1.h-1; p less than 0.001), angiotensin II (28 +/- 8 nmol/l and 60 +/- 8 nmol/l; p less than 0.001), aldosterone (0.16 +/- 0.04 nmol/l and 0.25 +/- 0.05 nmol/l; p less than 0.05), adrenaline (1.96 +/- 0.49 nmol/l and 2.92 +/- 0.51 nmol/l; p less than 0.05), and noradrenaline (12.01 +/- 1.25 nmol/l and 18.74 +/- 1.45 nmol/l; p less than 0.01) were significantly lower in the patients than in control subjects.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Autonomic neuropathy in non-insulin dependent (type II) diabetes mellitus. Possible influence of obesity.

To assess the prevalence of autonomic neuropathy (AN) in non-insulin dependent diabetes mellitus (NIDDM) and its relationships with other diabetic complications, duration of diabetes, and obesity, we evaluated 51 NIDDM patients (age 41-59 years, mean 49 years, duration of diabetes 0-15 years, mean 6.9 years). AN tests included a deep breathing test (E/I ratio) and an orthostatic tilt table test (acceleration and brake (25 of 51, 49%) and the most frequent disturbance was an impaired E/I ratio (18 of 25; 72%). There were no obvious correlations between AN indices and the duration of diabetes, symptoms of AN, peripheral neuropathy or retinopathy. However, an influence of obesity on AN was suggested. Patients with AN showed a significantly higher BMI than patients without AN (31.0 +/- 0.9 vs. 27.5 +/- 0.8; P less than 0.01).

Adult↗
PubMed1989

Platelet sodium and potassium ATPase [corrected] activity and noradrenaline efflux rate in relation to autonomic and peripheral nerve function in insulin-dependent diabetic patients.

Low sodium and potassium adenosine triphosphatase (ATPase) activity has been proposed as a mechanism behind diabetic neuropathy. In this study the platelet ATPase activity and platelet noradrenaline efflux rate were determined in 47 insulin-dependent diabetes mellitus (IDDM) patients and 20 controls. Ulnar motor conduction velocities, tested in a subgroup, were lower in patients than in controls (52.7 +/- 1.3 m s-1 vs. 61.3 +/- 1.4 m s-1; P less than 0.001). Platelet ATPase activity tended to be increased in the patients compared with the controls (29.9 +/- 1.0 x 10(-3) min-1 vs. 26.9 +/- 1.1 x 10(-3) min-1; NS). In ulnar nerve function tested subjects, ATPase activity was higher in patients than in controls (31.2 +/- 1.7 x 10(-3) min-3 vs. 25.9 +/- 1.3 x 10(-3) min-1; P less than 0.01). The platelet noradrenaline efflux rate tended to be higher in patients with lower brake indices, a sign of autonomic neuropathy, than in controls (29.0 +/- 3.0 x 10(-3) min-1 vs. 21.2 +/- 0.9 x 10(-3) min-1; P less than 0.05). The platelet ATPase activity was not decreased in IDDM patients, however, a connection between diabetic autonomic neuropathy and platelet transmittor leakage was indicated.

Adult↗
PubMed1989

Impaired responses of plasma catecholamines to exercise in diabetic patients with abnormal heart rate reactions to tilt.

The plasma catecholamine response to a standardized bicycle exercise test was evaluated in 24 insulin-dependent diabetic (IDDM) patients in whom the heart rate reactions to deep breathing (E/I ratio) and to tilt, the immediate acceleration and the transient deceleration (acceleration and brake indices), had been assessed as tests of autonomic neuropathy. Patients with an abnormal acceleration index (n = 8) showed, compared with non-diabetic (n = 18) controls who had participated in previous studies, an impaired increment in noradrenaline during exercise (80% of maximal working capacity) (MWC) (12.38 +/- 1.46 nmol l-1 vs. 18.74 +/- 1.45 nmol l-1; P less than 0.01) and adrenaline (50% of MWC: 0.25 +/- 0.04 nmol l-1 vs. 0.54 +/- 0.08 nmol l-1; P less than 0.05). Similarly, patients with an isolated abnormal brake index (n = 6), i.e. with a normal acceleration index and a normal E/I ratio, showed compared with controls an impaired increment in noradrenaline (9.53 +/- 1.66 nmol l-1 vs. 18.74 +/- 1.45 nmol l-1; P less than 0.01) and adrenaline (1.41 +/- 0.22 nmol l-1 vs. 2.92 +/- 0.51 nmol l-1; P less than 0.05) during 80% of MWC. IDDM patients with abnormal heart rate reactions to tilt, an abnormal acceleration index or an abnormal brake index show impaired catecholamine responses to exercise, which can be demonstrated also in patients without signs of parasympathetic neuropathy.

Acceleration↗
PubMed1988

Diazo-positive metabolites in urine from workers exposed to aromatic nitro-amino compounds.

The amount of diazo-positive compounds in urine from workers at a chemical plant producing pharmaceuticals and explosives was determined in samples collected after work and after a holiday. Forty-five persons working with aromatic nitro-amino compounds (ANA) showed a statistically significant (p less than 0.01) increase in the exposed samples (1.21 +/- 1.40 mmol/mol creatinine) compared to the unexposed samples (0.56 +/- 0.31 mmol/mol creatinine). No increase in the level of diazo-positive metabolites was found in the 25 workers not exposed to ANA compounds. In a follow-up study, 32 trinitrotoluene (TNT) workers were divided into three exposure categories and seemed to show a dose-dependent increase in the level of urinary diazo-positive metabolites. However, there was a considerable interindividual variation. The method seems suitable for the biological assessment of exposure to ANA compounds--at least on a group level. This may be valuable, especially in situations where significant dermal uptake is expected.

Amines↗
PubMed1987

A flowthrough fecundity test with Nitocra spinipes (Harpacticoidea Crustacea) for aquatic toxicity.

A sublethal flowthrough fecundity test with the euryhaline harpacticoid copepod Nitocra spinipes has been developed as a complement to the acute toxicity test (for 48 or 96 hr LC50) with the same species (B-E. Bengtsson, 1981, Mar. Pollut. Biol. 9,238-241). Bacterial suspension as feed and test water are continuously fed by a peristaltic pump to the system. Newly fertilized females with ovigerous bands are harvested from laboratory cultures and put into the test vessels at the start of the experiment. They are then exposed to a series of concentrations of chemicals or industrial effluents for 13 days. The amount of live offspring (metanauplia and copepodids) are recorded and an EC50 for fecundity is calculated. The report gives a detailed technical description of the test system and presents the results from 11 tests with pure chemicals (Zn, Cd, As, and pentachlorophenate) and six industrial effluents (pulp industry, textile industry, and refinery) in salinities ranging from 3 to 25%.

Animals↗