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Biomedical subjects

I Akesson

Publications and source records attributed to I Akesson.

At least 19 recordsLinked to original sources
PubMed2001

Self-reported and measured time of vibration exposure at ultrasonic scaling in dental hygienists.

In the present study, our objective was to quantify the daily duration of vibration exposure from ultrasonic scaling in dental hygienists and to compare different methods of self-estimates to time-recorded measurements. The exposure time was self-estimated by use of diary and interview methods in 10 subjects. We found that the measured total daily exposure time was limited, only on average 12min, with a great variation, however, between and within the subjects. Self-assessed duration of exposure was overestimated, on average three times higher with a diary and even more at an interview (8 times). In conclusion, the objectively measured exposure time was short and clearly overestimated in self-reports.

Adult↗
PubMed2000

Musculoskeletal symptoms among dental personnel; - lack of association with mercury and selenium status, overweight and smoking.

Our objective was to describe the occurrence of musculoskeletal symptoms and how they affect the daily life of three different occupational groups of dental personnel. A cross sectional-study was performed among 268 dental staff members and 111 referents. Female dental hygienists and female dentists showed, compared with their referents, higher prevalence of symptoms during the past 12 months from neck, shoulders and hands/wrists. Both dental groups also had higher frequencies of combined symptoms from these body regions, as well as longer duration of symptoms in neck and shoulders during the past 12-month period. Male dentists had higher frequencies of neck and shoulder symptoms compared with their referents. Female dental assistants did not deviate from their referents. The symptoms from each single body region, or the occurrence of symptoms from multiple regions in a subject, did not show any statistically significant association with mercury (whole blood and urinary levels) or selenium (plasma level) status, neither with smoking habits nor overweight (Body Mass Index). The high frequency of musculoskeletal disorders probably reflects the specific work load in dentistry, with high demands on vision and precision and fine manipulative hand movements and work with unsupported, elevated arms. The symptoms might impair work capacity and the future possibility to stay in the profession. Further studies are needed to verify this.

Adult↗
PubMed1999

Musculoskeletal disorders among female dental personnel--clinical examination and a 5-year follow-up study of symptoms.

OBJECTIVES: To explore the natural course of musculoskeletal disorders during a 5-year period among dental personnel, to survey findings and diagnoses according to a standardized protocol, and to compare and evaluate different methods for the detection of musculoskeletal disorders in a population. METHODS: In a 5-year follow-up study, dental personnel (n = 90) and referents (n = 30) were studied. The Nordic questionnaire (years 0 and 5), the present pain rating according to the Borg category ratio scale, and physical examination (year 5) were used. RESULTS: In year 0 the prevalence of symptoms in the shoulders, the wrists/hands, and, unexpectedly, the hips was higher in the dental personnel as compared with the referents. Furthermore, those (16%) who had left the dental profession during the observation period showed a higher prevalence of and, often, combined symptoms from several body regions in year 0 than did those who stayed. Dental personnel who remained in the profession tended to have an increased risk of developing more symptoms in the shoulders and the elbows/wrists/hands in year 5 as compared with year 0 and at year 5 were in more pain and had received more diagnoses for the neck/shoulder region relative to the referents. Furthermore, there was a considerable variation in symptoms during the follow-up period. The sensitivity of the pain rating and of the Nordic questionnaire in detecting musculoskeletal disorders was high for the neck and shoulders but was not as high for the elbow, wrists/hands, or hips. The association was better for diagnoses than for findings. The opposite patterns were observed for specificity. CONCLUSIONS: Dental personnel had an increased risk of developing musculoskeletal disorders as verified by symptoms and diagnoses and more painful or persistent conditions. This led to a selection out of work. The questionnaire and the present pain rating gave a relatively good picture of the prevalence of musculoskeletal disorders arising from the neck, shoulders, and hips and would be useful as screening tools. Their sensitivity in detecting disorders was higher for diagnoses than for findings. However, these methods were not as sensitive for disorders involving the elbows/wrists/hands. Physical examinations gave more detailed information.

Adult↗
PubMed1998

Evaluation of a workplace redesign of a grocery checkout system.

The aim of this study was to evaluate the effects on the working postures and movements of a cashier when two different locations of the scales (one to the left of the cashier, the other under the conveyer belt in front of the cashier) were used in a grocery checkout system. Two cashiers (of average stature and short stature) were videotaped while working, in both sitting and standing working positions. Analysis of the video tapes was performed using the WOPALAS method and video observations. The results of the study show that the design of the checkout system with the scales under the conveyer belt provides a more favourable working position for both the taller and the shorter cashier. Additionally, the results indicate that a standing position is more favourable than a sitting one for the taller cashier while for the shorter cashier the sitting position is better.

Ergonomics↗
PubMed1997

Quantifying work load in neck, shoulders and wrists in female dentists.

OBJECTIVE: To assess the work load in neck and upper limbs of dentists. METHODS: Twelve right-handed female dentists (six with and six without a history of definite neck/shoulder disorders, pair-wise matched for age) were studied when performing authentic dental work. Electromyography (EMG) was used to quantify the muscular load of the shoulders bilaterally and of the right forearm. Positions and movements of the head and wrists were measured, using inclinometers and electrogoniometers. RESULTS: During work, the median load for the right upper trapezium muscle was 8.4% of the maximal voluntary EMG activity (MVE); during 90% of the time the load was > or = 3.3% MVE ("static" load). The figures were somewhat lower on the left side (7.0% and 2.5% MVE, respectively). Subjects with disorders had over all lower load levels for the trapezius muscles, although not statistically significant at < 0.05, than those without disorders. During a standardized reference contraction for the trapezius, the load was 17% MVE, and the quotient between MVE and torque [normalized to maximal voluntary torque (MVC)] was 0.5. These figures may be used for transformations. The muscular load on the right forearm was similar to the loads on the trapezius. The head was, on average, forward tilted > or = to 39 degrees, and during 10% of the time > or = 49 degrees. The left hand was held in more static positions, with palmar flexion and ulnar deviation, also reflected by lower angular velocities and repetitiveness, as compared with the right one, which was dorsiflexed. CONCLUSIONS: Dentists are exposed to high load on the trapezius muscles bilaterally, and steep, prolonged forward bending of the head. Further, for the wrists the postures were constrained, but the dynamic demands were low.

Adult↗
PubMed1995

Neuropathy in female dental personnel exposed to high frequency vibrations.

OBJECTIVE: To evaluate early neuropathy in dental personnel exposed to high frequency vibrations. METHODS: 30 dentists and 30 dental hygienists who used low and high speed hand pieces and ultrasonic scalers were studied, and 30 dental assistants and 30 medical nurses not exposed to vibration (all women). Vibrotactile sensibility, strength, motor performance, sensorineural symptoms and signs, and vascular symptoms in the hands, as well as mercury concentrations in biological samples and cervicobrachial symptoms, were studied. RESULTS: The two groups exposed to vibration had significant impairments of vibrotactile sensibility, strength, and motor performance, as well as more frequent sensorineural symptoms. In the dentists there were significant associations between the vibrotactile sensibility and strength, motor performance, superficial sensibility, and sensorineural symptoms. There were no associations between these findings and cervicobrachial symptoms, mercury concentrations, or smoking. There was no increase of vascular symptoms of the hands in the groups exposed to vibration. CONCLUSION: Dental hygienists and dentists had a slight neuropathy, which may be associated with their exposure to high frequency vibrations, and which may be detrimental to their work performance. Thus, development of safer equipment is urgent.

Adult↗
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↗
PubMed1990

Effects of a gonadotropin-releasing hormone agonist on progesterone formation in cultured human granulosa cells.

Human granulosa cells from follicles of natural cycles (13 women) in mid- or late follicular phase were cultured in modified Medium-199. Human luteinizing hormone (100 micrograms/l), follicle-stimulating hormone (100 micrograms/l) and gonadotropin-releasing hormone agonist (GnRHa) (10(-12) to 10(-6) mol/l) alone or in combination were added to the culture medium. Medium content of progesterone was analysed. In granulosa cells obtained in the mid-follicular phase, the basal progesterone formation averaged 0.5 pg.cell-1.(48 h)-1. FSH caused a 3-fold stimulation. GnRHa (10(-6) mol/l) had a variable influence on the basal progesterone formation, whereas it consistently inhibited (40-50%) the FSH response. In granulosa cells from late follicular phase basal progesterone formation averaged 5 pg.cell-1.(48 h)-1 and was stimulated 3- to 6-fold by LH. GnRHa (10(-6) mol/l) stimulated the basal progesterone formation and caused a tended to potentiate the LH response on progesterone formation. It is concluded that GnRHa at relatively high concentrations exerts direct effects on gonadotropin-stimulated progesterone formation of human granulosa cells and that these effects are different (inhibitory or stimulatory) dependent on the degree of follicular maturation, and/or type of gonadotropin used.

Cells, Cultured↗
PubMed1987

Aging and urinary vasopressin excretion in healthy men.

The influence of age on urinary excretion of arginine vasopressin (antidiuretic hormone) was examined in three groups of healthy men, 25 +/- 1 (n = 12), 40 (n = 44) and 50 years of age (n = 28) respectively. Despite increasing plasma vasopressin with progressive age (2.5 +/- 0.6 vs. 3.5 +/- 0.4 vs. 7.4 +/- 1.0 ng/l, respectively) (means +/- SE), urinary excretion of vasopressin turned out similar (6.7 +/- 1.0 vs. 6.8 +/- 0.8 vs. 6.9 +/- 0.6 ng/h). No differences in sodium excretion, serum osmolality and creatinine clearance appeared that could explain these findings. The present results suggest that age-related impairment of renal concentrating capacity is compensated for by increasing circulating plasma vasopressin. Furthermore, differences in tubular handling of the hormone with age may explain the present findings, and may be another compensatory mechanism for decreased urinary concentrating ability.

Adult↗
PubMed1986

The effect of sodium depletion and potassium supplementation on vasopressin, renin and catecholamines in hypertensive men.

Seventeen 50-year-old hypertensive men (157 +/- 4/110 +/- 2 mmHg, mean +/- SE) were given low sodium diet for one week, which was supplemented with potassium the following week. The urinary Na+/K+ excretion ratio changed from 2:1 to 1:5 and 1:12, respectively, during dietary intervention. Arterial plasma vasopressin decreased by 3.4 +/- 1.7 ng/l (0.05 less than p less than 0.10) and urinary excretion of vasopressin was reduced by nearly 50% (p less than 0.001) during sodium depletion, while plasma noradrenaline increased by 38% (p less than 0.001) and plasma dopamine showed an increase by 58% (p less than 0.001). Plasma renin concentration increased four-fold during sodium depletion (p less than 0.001). With combined salt depletion and potassium supplementation, arterial plasma vasopressin decreased by 9.5 +/- 4.0 ng/l (p less than 0.05) compared to control. Urinary excretion of vasopressin together with plasma noradrenaline and dopamine were unchanged during the second week. The reduction of blood pressure was most marked during the first week (143 +/- 3/103 +/- 2 mmHg, p less than 0.05), but continued to fall also during the second week. Thus, during sodium restriction in middle-aged hypertensive men, blood pressure reduction occurs concomitantly with inhibited vasopressin release, despite enhanced renin and catecholamine release. Potassium supplementation during sodium restriction induces only minor changes in these variables.

Blood Pressure↗
PubMed1985

Intra-abdominal pressure and trunk muscle activity during lifting. III. Effect of abdominal muscle training in chronic low-back patients.

Isometric training of the abdominal muscles is often recommended in programs of primary or secondary prevention for low-back pain. In this study 20 male workers with 2-18 years' history (average 5 1/2 years) of low-back pain without sciatica went through intense isometric abdominal muscle training for 5 weeks. Before and after training the subjects had trunk flexion and extension strength tests and a series of standardized lifts. The intraabdominal pressure (IAP) and the EMG activity of the oblique abdominal muscles, and of the erector spinae muscle were recorded. It was found that: the strength of the abdominal muscles increased; the increased strength was correlated to an improved recruitment of motor units in the oblique abdominal muscles; the EMG activity of the oblique abdominal muscles when lifting decreased after training, i.e. the acquired ability to recruit more motor units was not made use of; the IAP at lifting was generally not affected. A better knowledge of the mechanisms responsible for the IAP in different situations is needed to support advice on training or other prevention.

Abdomen↗
PubMed1983

Intraabdominal pressure and trunk muscle activity during lifting--effect of abdominal muscle training in healthy subjects.

Isometric training of the abdominal muscles is recommended as a preventive measure against low back complaints in the hope that the increased strength of the abdominal muscles should result in an increased intraabdominal pressure when lifting. There is, however, neither experimental nor clinical proof of this hypothesis. Twenty healthy young men went through intense isometric training of the abdominal muscles for five weeks. Before and after training the subjects were put through a standardized test programme, measuring the strength of abdominal and back muscles, and a series of lifts, 10, 25, and 40 kg, leg lifts and back lifts. The intraabdominal pressure (IAP), and the EMG activity of the oblique abdominal muscles, and of the erector spinae muscle were recorded. It was found that: The strength of the trunk flexors increased markedly after training. The activity of the oblique abdominal muscles when lifting decreased after training, i.e. motor unit recruitment was not improved. The IAP at lifting was not affected by training. The activity of the oblique abdominal muscles was of no decisive importance to the IAP. The strength of the back muscles increased, but the activity of the back muscles at lifts was not affected by training. In back lifts there was no detectable activity of the back muscles during the beginning of the lifting and during a great part of the lowering. In back lifts the maximum activity of the abdominal muscles appeared long before the peak of the IAP which may be of importance with regard to the pathogenesis of inguinal hernia. Further investigation is needed, both to study the effect of training on patients with back complaints, and to study the factors determining the IAP.

Abdomen↗
PubMed1982

Urinary calcium oxalate monohydrate crystals in ethylene glycol poisoning.

Four patients admitted for ethylene glycol intoxication had massive crystalluria, predominantly of needle-shaped calcium oxalate monohydrate--sometimes referred to as the 'hemp seed' habit. A few 'envelope' type crystals of calcium oxalate dihydrate were observed in one urine sample. Although not a pathognomonic sign, the presence of a large number of calcium oxalate monohydrate crystals (Whewellite) supports the diagnosis of ethylene glycol poisoning in patients having a metabolic acidosis of unknown aetiology. We conclude that the monohydrate form rather than the dihydrate form is the predominant type of calcium oxalate crystal formed in ethylene glycol poisoning.

Adult↗
PubMed1982

The in vivo metabolism of C3 in hepatobiliary disease associated with ulcerative colitis.

To study possible pathogenetic mechanisms in hepatobiliary disease associated with ulcerative colitis (UC), we performed a metabolic investigation of component C3 of the most important effector of humoral immunity, the complement system. Purified and biologically active C3 was labelled with 125I and injected together with 131I-albumin into seven patients. All had hepatobiliary disease, and total colectomy had previously been performed for severe UC in all patients. The results were compared with those for 16 normal individuals. The fractional catabolic rates (FCR) were calculated by the metabolic clearance method and by analysis of the plasma radioactivity disappearance curve. An increase in the FCR of C3 was found in the patient group, indicating that humoral immune mechanisms may be of pathogenetic importance in hepatobiliary disease associated with UC. The increased FCR was compensated for by and increased synthesis rate of the protein.

Adult↗
PubMed1980

Excretion of casts and uromucoid in urine after prolonged heavy exercise.

Excretion of uromucoid, albumin and casts in urine were determined in twenty well-trained men, ten aged 20-30 years, and ten aged 50-60 years, before, during and after a 70 km cross country ski race. During the race there was only a slight increase in uromucoid excretion, but a marked increase in the excretion of casts and albumin. The older subjects had a tendency to lower urine output during the race compared to the younger group. Reduction of urine output below ca. 25 ml/h was accompanied by a conspicuous increase in urine cast and albumin concentrations, with only a slight increase in uromucoid concentration, and even a reduction in uromucoid excretion. No significant relationship was found between cast excretion and uromucoid concentration. Thus the gross cylindruria observed during longstanding exercise must be ascribed to other urinary factors facilitating the formation of casts.

Adult↗
PubMed1980

The metabolism of C3 in adult coeliac disease.

To study possible pathogenetic mechanisms in adult coeliac disease, we performed a metabolic investigation of a component (C3) of the most important effector of humoral immunity, the complement system. Purified and biologically active C3 was labelled with 125I and injected together with 131I-labelled albumin into six patients with adult coeliac disease exhibiting different degrees of disease activity. The same labelled preparations were given to 12 normal individuals. Plasma and urine radioactivity were studied for a total of 8 days. Fractional catabolic rates (FCR) and synthesis rates were calculated by the metabolic clearance method. Other mathematical methods were not used because a final straight exponential was not always obtained, probably owing to extravascular sequestration of protein. An increased FCR was found in most patients, with the highest values seen in active, untreated disease. This suggests that activation of complement by immune complexes may be a pathogenetic factor in adult coeliac disease.

Celiac Disease↗