Search PubMedSearch

Biomedical subjects

A Wennberg

Publications and source records attributed to A Wennberg.

At least 19 recordsLinked to original sources

The effect of short-term lipid infusion on liver function and biliary secretion in rats.

This study was undertaken to determine the effect of various lipid emulsions on the hepato-biliary system in rats. Rats were randomly divided into six groups and infused continuously for 48 hr with either long-chain triglycerides (LCT), medium-chain triglycerides (MCT) or a mixture of MCT and LCT. One group infused with physiological saline solution served as controls. Throughout this period the rats received a fat free diet ad libitum. During the last hour of lipid infusion bile was collected for determination of bile flow and composition. Subsequently, the rats were sacrificed and the morphology and lipid content of the liver determined. Only LCT lipid emulsions induced morphological changes and increased liver cholesterol content. In two rats infused with radiolabeled LCT, no labeled cholesterol was found in the liver, indicating that the excess hepatic cholesterol level may originate from enhanced cholesterol mobilization to the liver. Biliary cholesterol and phospholipid concentrations in LCT-treated rats were also elevated, as was the lithogenic index, whereas the other emulsions had no such effects. None of the emulsions affected the plasma liver function tests or bile flow. We therefore conclude that the lithogenicity of the bile in rats is directly related to the lipid components of the total parenteral nutrition and the type of triglyceride infused.

Animals

Prevalence of carnitine depletion in critically ill patients with undernutrition.

The aim of this study was to evaluate to what extent secondary carnitine deficiency may exist based on the prevalence of subnormal carnitine status in patients with critical illness and abnormal nutritional state. Healthy control patients (n = 12) were investigated and compared with patients with possible secondary carnitine deficiency, ie, patients with overt severe protein-energy malnutrition (PEM, n = 28), postoperative long-term (greater than 14 days) parenteral glucose feeding (250 g glucose/d, n = 7), severe liver disease (n = 10), renal insufficiency (n = 7), and sustained septicemia with increased metabolic rate (n = 8). Nutritional status, energy expenditure, creatinine excretion, and blood biochemical tests were measured in relationship to free and total carnitine concentrations in plasma and skeletal muscle tissue, as well as urinary excretion of free and total carnitine. The overall mortality rate was 48% within 30 days of the investigation in study patients with the highest mortality in liver disease (90%). The hospitalization range was 14 to 129 days in study patients. Most study patients had lost weight (4% to 19%) and had abnormal body composition. Patients with liver disease, septicemia, renal insufficiency, and those on long-term glucose feeding had significantly higher than predicted metabolic rate (+25% +/- 3%), while patients with severe malnutrition had decreased metabolic rate compared with controls. Patients with liver disease had increased plasma concentrations of free (96 +/- 16 mumol/L) and total (144 +/- 27 mumol/L) carnitine compared with controls (45 +/- 3, 58 +/- 7 mumol/L, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Aged

Prevalence and distribution of cervical dentine hypersensitivity in a population in Rio de Janeiro, Brazil.

The prevalence, distribution and possible causal factors of cervical dentine hypersensitivity were studied in a population from a Marine Dental Clinic in the city of Rio de Janeiro, Brazil. A total of 635 patients were examined for the presence of cervical dentine hypersensitivity by means of a questionnaire and intraoral tests (air and probe stimuli). There were 157 patients (25%) reporting to have hypersensitive teeth, but only 108 patients (17%) were diagnosed as having cervical dentine hypersensitivity. The prevalence of hypersensitivity was higher among females than males, but this difference was not statistically significant. Most females with hypersensitivity were aged 20-49 and most males were aged 40-59. Incisors and premolars had the highest prevalence of dentine hypersensitivity to air and probe stimuli, while molars had the lowest. The presence and history of dentine hypersensitivity were positively correlated with previous exposure to periodontal treatment. Only a few of the patients who claimed to have dentine hypersensitivity had tried treatment with desensitizing toothpastes or sought professional help.

Adolescent

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

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

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

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

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

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

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

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

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

A method for toxicity screening of biomaterials using cells cultured on millipore filters.

In the present paper a tissue culture technique is described whereby the toxicity of setting and solid materials may be evaluated. A cell monolayer was established on a millipore filter which was placed on an agar medium, cell side down. Test specimens were placed on top of the millipore filter and were allowed to influence the cells through the filter for two hours. The cell reaction was assessed by incubating the cells, still adherent to the filter, for the demonstration of succinate dehydrogenase activity. Materials with a cytotoxic effect caused a zone of inhibited enzyme activity in the cell-material contact area. The filters were examined macroscopically and scores from 0 to 3 were given to grade the severity of the cell response. Unset and set silicate cement, zinc phosphate cement and an acrylic resin were tested. The results obtained were consistent and in accordance with those of previous reports. The method was simple and rapid and appeared suitable for the assay of larger test series.

Animals

Ameloblasts--ion transport function.

Recent autoradiographic and in vitro studies have produced evidence that the cells of the enamel organ limit the movement of calcium into enamel during the matrix secretion phase, but have no effect on movement of calcium during the maturation phase. The cells of the enamel organ do not seem to control the flux of phosphorus into enamel at either phase of development. This concept is consistent with current theories on the control of ion fluxes into developing bone.

Ameloblasts

Long-term exposure to electric fields. A cross-sectional epidemiologic investigation of occupationally exposed workers in high-voltage substations.

In the present epidemiologic study, 53 workers with a long-term (more than five years) exposure to the electric field of 400 kV substations were examined and compared with a matched reference group of 53 nonexposed workers from the same power companies. Matching variables included age, geographic location and employment time. The aim of the study was to investigate the possibility of persistent, chronic health effects in the exposed group as a consequence of exposure. The investigation indluded the nervous system (neurasthenic symptoms, psychological tests, electroencephalography), the cardiovascular system (symptoms, blood pressure, electrocardiography), and the blood (hemoglobin, red blood cells, reticulocytes, white blood cells including differential count, thrombocytes, sedimentation rate). Fertility was also assessed. The results showed no differences between the exposed and reference groups as a consequence of the long-term exposure to the electric fields. The groups differed, however, in that the exposed group had (a) consistently better results on the psychological performance tests, (b) a fewer number of children, especially boys, and (c) somewhat higher education. The differences in test results were due to the higher education among the exposed. The difference in number of children was also thought to be related to factors other than exposure since it was found to be present already 10--15 years before the work in 400 kV substations began.

Adult