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Biomedical subjects

A Wennberg

Publications and source records attributed to A Wennberg.

At least 37 records · Page 2Linked to original sources
PubMed1992

Cytotoxicity of corroded gallium and dental amalgam alloys. An in vitro study.

The cytotoxicity of one gallium and three different dental amalgam alloys was assessed in a cell culture system. Two evaluation methods were used, the filter method and an extraction method. Before being tested, set specimens of the alloys were stored in 0.9% NaCl solution for 1 and 10 weeks, to corrode. The alloys showed various degrees of cytotoxicity, ranging from mild to marked. Differences were found between the two testing methods, but in most cases no major differences in cytotoxicity were found between the Ga alloy and the amalgams. The results encourage further study and development of the Ga alloy, which is mercury-free.

Biocompatible Materials↗
PubMed1992

General condition of asymptomatic patients with advanced colorectal cancer receiving palliative chemotherapy. A longitudinal study.

A Nordic multicenter study in asymptomatic patients with advanced colorectal cancer compared initial chemotherapy with sequential methotrexate-5-FU with leucovorin rescue (MFL) for 6 months versus primary expectancy with chemotherapy only after the appearance of symptoms. The study (183 patients randomized between January 1985 and February 1990) showed that symptom-free survival, progression-free survival and survival respectively were about 6 months longer in the group of patients randomized to initial MFL. Whether these prolongations could be achieved without an impaired 'quality of life' was studied in an associated study. Between January 1985 and March 1987, 43 patients were randomized at one of the hospitals, 36 of which were interviewed with a questionnaire at randomization. Even if all these patients were considered, by the physician, to be 'free of symptoms from their disease', 16/36 (44%) had symptoms that could be referred to the disease. In spite of this, the patients were in a good general condition, and considerably better off than patients considered to have 'symptoms from the disease' who were interviewed with the same questionnaire when randomized in a parallel study of symptomatic patients. Patients randomized to initial chemotherapy and interviewed longitudinally maintained their good condition throughout treatment. Toxicity was mild, although the patients expressed more adverse effects than the physicians recorded. Since symptom-free survival, progression-free survival and survival were statistically significantly longer in the group of patients randomized to MFL also in this associated study, it is concluded that initial chemotherapy can prolong symptom-free survival and survival without reduced 'quality of life' during the treatment period.

Adult↗
PubMed1992

Preclinical neurophysiological signs of parkinsonism in occupational manganese exposure.

To study the effects from low level exposure to manganese, 30 men at steel smelting works and 60 nonexposed reference subjects, were neurophysiologically examined using: (i) Electroencephalogram (EEG), Event related auditory evoked potential (AEP/P300), Brain stem auditory evoked potential (BAEP) and diadochokinesometry. No group differences concerning EEG or BAEP were found. Diadochokinesis was slower and there was a tendency towards prolonged P300 latency in the exposed group as compared to the referents. These effects may be interpreted as early (subclinical) signs of disturbances of the same type as parkinsonism.

Adult↗
PubMed1991

New Swedish occupational standards for some organic solvents.

In 1987, the Swedish government requested a unique investigation of the consequences of a 50% reduction of permissible exposure levels (PEL) for organic solvents. As a result, 29 solvents were investigated and for 25 of them a reduction--if not to 50%--was suggested. For 13 of the solvents, there existed scientific arguments for a reduction of the PEL. For 12 solvents, no specific biomedical information was available. Presumed interactions between solvents may have influenced the decisions, but technological/economic feasibility criteria may also have been used by the regulators. This suggests that the use of technological/economic feasibility criteria can give lower PELs than health criteria. This is within the intentions of the Swedish Work Environment Act.

Acetates↗
PubMed1991

Incidence of work-related disorders and absenteeism as tools in the implementation of work environment improvements: the Sweden Post strategy.

In 1989, a comprehensive, five-year work environment project (Postal Work Environment [PWE] 2000) was launched by Sweden Post (SP). Its purpose was to identify the jobs and employees with the most exposed work environments and, in conjunction herewith, to initiate remedial programmes. Standardized interviews with a selection of employees and statistical and epidemiological evaluation of illness absenteeism and occupational injuries served as input data for devising different measures of work-related ill health (subjective complaints, symptoms, illness, illness absenteeism, and occupational injury). The results provided an incentive to regional action programmes, in which 'risk areas and risk occupations' were correlated with the load factors, primarily in ergonomic and work organization areas, cited in interview replies. In its regional efforts. PWE 2000 served as a stimulus/catalyst in the implementation of various regional action programmes.

Absenteeism↗
PubMed1991

Effects of intravenous nutrition on lipoprotein metabolism, body composition, weight gain and uremic state in experimental uremia in rats.

The effect on serum lipids, lipoprotein fractions, body composition, weight gain and uremic state of including fat in intravenous nutrition was evaluated in rats with chronic uremia. Uremic rats were given high energy (1385 kJ.kg body weight-1.day-1), low nitrogen (0.6 g N.kg body weight-1.day-1) total parenteral nutrition (TPN) for 12 d with either glucose or glucose plus 30% lipids (Intralipid) as the energy source. Additional uremic and nonuremic groups were fed a standard diet orally. During TPN, serum triglyceride and cholesterol levels were slightly higher in rats fed lipid-based TPN compared to those administered glucose-based TPN or fed the oral diet; but there were no differences 8 h after feeding. The serum lipoprotein fractions showed accumulation of lipids in LDL resulting from the lipid-based TPN but no differences in VLDL. In orally fed uremic rats, more lipids were found in HDL than in the TPN-treated rats. The fractional clearance of the fat emulsion was normal and independent of the nutrition composition. Uremic rats administered lipid-based TPN for 21 d had the same weight gain as orally fed, nonuremic control rats (23 +/- 3 vs. 22 +/- 2%); glucose-based TPN did not support normal growth (10 +/- 1%). Uremic rats fed orally did not grow and retained significantly more body water than TPN-fed uremic rats. In uremic animals, lipid-based TPN also was associated with normal body composition despite significantly lower levels of carnitine in plasma, skeletal muscle and heart tissue.(ABSTRACT TRUNCATED AT 250 WORDS)

Administration, Oral↗
PubMed1991

Clinical evaluation of pulp and dentine sensitivity after supragingival and subgingival scaling.

The exposure of dentinal tubules by the removal of root cementum on scaling procedures has been proposed to be a source of pulp injury and to cause dentine hypersensitivity. The aim of this study was to evaluate the sensitivity of the pulp and dentine after supragingival and subgingival scaling. Eleven patients with periodontally diseased mandibular incisors were selected. The subjects were divided into two groups according to marginal bone loss. The pulp sensitivity was evaluated by an electric pulp test. Dentine sensitivity was evaluated with two forms of controlled stimulations (probe and air-jet) and with a questionnaire. No changes in pulp sensitivity were found after scaling, but a clinically significant increase in dentine sensitivity to probe and/or air stimuli was observed in 6 patients. Five of these were also sensitive to daily life stimuli. A natural mechanism of desensitization seemed to have occurred two weeks after subgingival debridement. This study showed that supragingival and subgingival scaling might cause a more or less transient occurrence of dentine hypersensitivity.

Adult↗
PubMed1991

Follow-up study of endodontic status in an adult Swedish population.

The purpose of this study was to examine changes in the endodontic status of selected teeth in a population over time, in order to get a long-term perspective of endodontically treated teeth. A random sample of the adult Swedish population was selected in 1974 and offered a clinical and radiographic examination. Eleven years later 351 of the selected persons attended a follow-up examination (1985). In radiographs, covering the mandibular premolar and molar regions, the status of 1974 was directly compared, tooth by tooth, with the status of 1985. The results showed that a number of endodontically treated teeth with an apical periodontitis healed during the observation period. During the same period, approximately the same number of endodontically treated teeth presented with a new apical periodontitis. This finding suggested that cross-sectional studies could provide reliable information on the long-term success rate of endodontic treatment at the population level. The periapical lesions that persisted or developed during the observation period were strongly related to incomplete root canal obturation, which is in agreement with observations in follow-up studies from teaching and specialist clinics.

Adult↗
PubMed1991

Manganese exposure in steel smelters a health hazard to the nervous system.

In a study of the effects of low-level exposure to manganese (0.19-1.39 mg/m3 for 1-45 years) 30 men (aged 20-64 years) from two steel smelting works and 60 unexposed referents (aged 22-65 years) were examined with the use of a general health inquiry, electroencephalography, event-related auditory evoked potentials, brain-stem auditory evoked potentials, diadochokinesometry, simple and complex reaction time, finger tapping, digit span, mental arithmetic, vocabulary, a coding task, manual dexterity, symptoms, and mood scales, the diagnostic interview scheme, a dynamic rating scale for neurasthenic syndrome, and a comprehensive psychopathological rating scale. No group differences were found in the electroencephalography or the psychiatric examinations. However, there were increased frequencies of some symptoms, the diadochokinesis was slower, the P-300 latency and reaction time were increased, and finger-tapping and digit-span performance were impaired in the exposed group. These effects were interpreted as early (subclinical) signs of disturbances of the same type as parkinsonism.

Adult↗
PubMed1990

Adhesion of root canal sealers to bovine dentine and gutta-percha.

The adhesive properties of eight root canal sealers, applied as a thin layer between a dentine and a gutta-percha surface, were investigated. Tensile bond strengths ranged from 0.02 MPa (Sealpex) to 2.38 MPa (AH26). Inspection of fractured surfaces indicated failure of adhesion to dentine (Tubli-Seal) and to gutta-percha (AH26, Diaket) as well as failure of cohesion (CRCS, Kloroperka N-O, ProcoSol, rosin chloroform, Sealapex). Pretreatment of the dentine surface with EDTA caused a significant increase in bond strength for ProcoSol, rosin chloroform, Sealapex, and Tubli-Seal.

Adhesiveness↗
PubMed1989

Quality of life during cytostatic therapy for advanced symptomatic colorectal carcinoma: a randomized comparison of two regimens.

Physician- and patient-rated 'quality of life' was studied in patients receiving chemotherapy for advanced symptomatic colorectal cancer. The patients participated in a Nordic multicentre randomized study comparing single-drug 5-fluorouracil (5-FU) with a combination of sequential methotrexate-5-FU with leucovorin rescue (MFL). Forty-four patients (all patients included at one of the hospitals) entered this associated 'quality of life' study, 22 in each group. In the MFL group, five patients had a partial remission (PR) and seven prolonged stationary disease (SD), whereas in the 5-FU group, only one patient had a PR and two SD. Median survival was longer in the MFL group (9 months) than in the 5-FU group (4 months). According to the physicians' judgement, 12 (55%) of the patients randomized to MFL experienced improved 'quality of life' compared to five (23%) in the 5-FU group. Patients' ratings gave the same figure (55%) in the MFL group, whereas only two (9%) patients in the 5-FU group considered themselves improved. The correlations between physicians' and patients' ratings were good. Adverse effects of treatment were minor and influenced ratings negatively only in one patient (5-FU group). Items that reflected changes in everyday activities discriminated better than other items in the 'quality of life' assessment. Since 'quality of life' measures were better in the MFL group in this associated study, and since objective and subjective responses, changes in Karnofsky performance status (KPS) and in survival also were better in the MFL group, not only in this study but also in the Nordic trial (249 patients randomized), we conclude that MFL is superior to 5-FU as a palliative treatment.

Adult↗
PubMed1989

Endodontic status and suggested treatment in a population requiring substantial dental care.

The purpose of this study was to analyse endodontic status and treatment suggested for Swedish citizens requiring substantial dental care. According to the Swedish dental insurance system, treatment plans including radiographs have to be submitted for approval if the estimated cost of treatment exceeds a certain level (USD 500 in 1977). A sample of 1094 treatment plans received during 1977 and 1978 was randomly selected. In the radiographs the number of remaining teeth was recorded, periapical condition was evaluated and the quantity and quality of previous endodontic treatment were estimated. In addition, treatment plans concerning the teeth with periapical lesions were studied. The results indicated that patients analysed in this study that needed expensive treatment had more missing teeth, more root-filled teeth and more teeth with periapical lesions than what has been reported in previous studies of samples supposed to accurately represent the Swedish population. However, the technical quality of the root fillings and the frequency of periapical lesions in root-filled teeth were the same as in previous studies, with high frequencies of inadequate root fillings and related unfavourable responses. Thus the patients in this study retained a significant need for endodontic treatment despite having already received a great deal of endodontic care. Further, it was found that nearly half of the observed periapical lesions would not be treated based on the submitted plans.

Adolescent↗
PubMed1989

Evaluation of alternatives to chloroform in endodontic practice.

Chloroform is used in endodontics for plasticizing gutta-percha points and for facilitating removal of gutta-percha root canal fillings in need of re-treatment. Adverse health effects from exposure to chloroform have been reported, and to improve occupational health, it would be advantageous if a less hazardous solvent could replace chloroform. In this study, methylene chloride, methyl chloroform, tetrahydrofuran, xylol and eucalyptol were tested for their capacity to dissolve or soften gutta-percha points compared with chloroform. The effect of the test solvents was assessed by measuring the depth of penetration of a small indentor of fixed weight and shape into a gutta-percha disk covered with the test solution for various time periods. Chloroform showed the most pronounced effect, followed by methylene chloride, tetrahydrofuran, and methyl chloroform. When both occupational health and gutta-percha solvent capacity were considered, methyl chloroform seemed to be an interesting alternative to chloroform.

Chloroform↗
PubMed1989

Acute effects of ELF electromagnetic fields: a field study of linesmen working with 400 kV power lines.

The aim of the study was to investigate the possible acute effects of exposure to electric and magnetic fields. Twenty six experienced linesmen, aged 25 to 52, were studied during two working days while performing a simulated routine inspection of insulators on steel poles of a 400 kV power line. During one of the working days the inspection was performed on a power line in operation and on the other day the same procedure was performed on an identical power line, which was not in operation. The two days were found to be comparable with regard to the physical workload which, on the basis of heart rate measurements, was estimated to be high. Exposure to the electric and magnetic fields was measured using a device designed for on-worker sampling on each linesman. The mean exposure for the working day was estimated to be 2.8 kV/m (SD = 0.35) and 23.3 microT (SD = 4.2). The possible effects of exposure were studied using a battery of four automated performance tests, EEG, a mood scale, and a questionnaire to assess subjective symptoms. All workers were examined immediately before and after each workday. Furthermore, blood samples were collected for each subject on three different occasions during each workday. The battery of behavioural tests comprised a test of simple reaction time, a vigilance test, a test of short term memory (digit span), and a perceptual test (symbol digit). The four EEG recordings for each worker were judged blindly and sorted with regard to amount and stability of alpha activity. The blood samples were used for an analysis of possible changes during the workday with regard to the following hormones: thyroid stimulated hormone, luteinising hormone, follicle stimulating hormone, prolactin, cortisol, testosterone, and neopterin. Detailed analyses of the results using both parametric and nonparametric tests showed no statistically significant difference between the two conditions which could be attributed to exposure to electric and magnetic fields.

Adult↗
PubMed1988

Whole body fat oxidation before and after carnitine supplementation in uremic patients on chronic haemodialysis.

This study has evaluated whether uremic patients on chronic haemodialysis with subnormal plasma levels of free carnitine show any alterations in whole body fat oxidation before and after one week with carnitine supplementation (60 mg/kg/day). Carnitine plasma levels changed from subnormal to supranormal levels of both free and total carnitine concentrations. This increase was not associated with any alteration in either oxygen uptake, carbon dioxide production, respiratory quotient or blood substrate levels such as glucose, glycerol, free fatty acids and lactate. The fractional oxidation of an intravenously infused fat emulsion (Intralipid) was 17% before and 19% after carnitine supplementation. No side effects were observed in spite of the rather high dose of carnitine administration. This study failed to demonstrate any impact on net whole body fat oxidation in carnitine substituted uremic patients with initially subnormal levels of free plasma carnitine.

Calorimetry, Indirect↗
PubMed1988

Anthropometric assessment of the nutritional status of preschool-age children in Cape Verde.

The nutritional status of preschool-age children (0-6 years old) in Cape Verde was assessed using anthropometric measurements in a survey that involved 17 017 children from all regions of the country. About 26% of the estimated population in the target age group was included. Data were collected through primary health care centres during the latter part of 1983. The nutritional indicators weight-for-height, weight-for-age, and height-for-age were compared with reference data from the U.S. National Center for Health Statistics. Values of the indicators below -2 standard deviations of the median were considered to represent moderate undernutrition, while values below -3 standard deviations were taken to indicate severe malnutrition.The prevalence of low weight-for-height (wasting) was 2.5%, while that of severe wasting was 0.6%. The corresponding prevalences of low height-for-age and weight-for-age were 13.1% and 17.2%, respectively, with severe categories representing 2.3% and 6.1%, respectively, of the cases in the total sample. There is therefore a relatively strong tendency towards growth retardation or chronic, moderate nutritional deprivation in preschool-age children in Cape Verde, although there exist interregional variations.

Anthropometry↗