Biomedical subjects

M Lilja

Publications and source records attributed to M Lilja.

At least 37 records · Page 2Linked to original sources

PubMed1998

Immunoglobulin- and complement-coated bacteria in pus from peritonsillar abscesses.

Fifty-five samples of pus were collected from 51 acute, non-perforated, two spontaneously ruptured and two recurrent peritonsillar abscesses (35 males and 18 females; median age 18 years) and analysed regarding (i) aerobic and anaerobic bacteria (standard culturing), (ii) morphology of bacteria and inflammatory cells (direct microscopy of acridine orange-stained material), and (iii) the percentage of bacteria coated with immunoglobulins IgG, secretory IgA (SIgA) and IgM and complement cleavage product C3b (immunofluorescence assay). Seventy-one per cent of the abscesses harboured a mixed bacterial flora of various aerobes and anaerobes. In none of the cases with a single bacterial species (27 per cent) could immunoglobulin- or complement-coated bacteria be found. In abscesses with a mixed flora, 18 per cent harboured IgG-coated, 15 per cent SIgA-coated, five per cent IgM-coated and five per cent C3b-coated bacteria, respectively. All pus samples contained inflammatory cells in abundance but they were mostly deformed and only occasionally could intracellular bacteria be recognized. Insufficient immunoglobulin-coating of bacteria might be an important aetiopathogenic factor in the development of a peritonsillar abscess. Bactericide in the abscesses is accomplished chiefly by protective mechanisms not dependent on antigen recognition by antibodies.

Adolescent↗

PubMed1998

Variants of renin-angiotensin system genes and echocardiographic left ventricular mass.

AIMS: Variants of renin-angiotensin system genes are shown to be associated with cardiovascular pathology. The association between renin-angiotensin system genes and left ventricular mass was investigated in a population-based case-control study. METHODS AND RESULTS: The association between echocardiographic left ventricular mass and both insertion/deletion polymorphism of the angiotensin-converting enzyme gene and the methionine-threonine variant at position 235 of the angiotensinogen gene was studied in a random cohort of 430 hypertensive and 426 control subjects. No differences in the adjusted left ventricular mass values between the different genotypes were seen among either the hypertensive or the control subjects, whether men or women, or in the subgroups of normotensive or physically active subjects. Gene variation had no statistically significant synergistic effect on left ventricular mass values. In control women, the deletion allele of the angiotensin-converting enzyme gene was associated with an increased risk of left ventricular hypertrophy. However, this finding was based on a small number of women with left ventricular hypertrophy and should be interpreted with caution. CONCLUSION: Variations in renin-angiotensin system genes had no major effect on left ventricular mass in this middle-aged population-based cohort of hypertensives and control subjects.

Adult↗

PubMed1998

Hyperinsulinemia and carotid atherosclerosis in hypertensive and control subjects.

OBJECTIVE: To analyze the relationships between carotid atherosclerosis measured as intima-media thickness (IMT) and different measures of insulin in a population-based case-control study of men and women. RESEARCH DESIGN AND METHODS: Carotid ultrasonographic measurements and 2-h oral glucose tolerance tests were performed in a random sample of 513 hypertensive subjects, aged 40-59 years, and in 518 age- and sex-matched control subjects. The associations between IMT and the different measures of insulin were analyzed through multiple regression and by insulin quintiles. The independent effect of insulin was estimated after concurrent adjustment for age, obesity, LDL cholesterol, and systolic blood pressure. RESULTS: The most powerful correlates with IMT were LDL cholesterol, age, systolic blood pressure, pack-years of smoking, and of the different insulin parameters, 2-h post-load insulin. In stepwise regression analysis, the independent predictors of the mean IMT were LDL cholesterol, systolic blood pressure, pack-years of smoking, and age (P < 0.0001) after adjustment for the independent predictors. In analysis of variance, no positive association of insulin parameters with IMT was found between the 2-h insulin quintiles after adjustment for the independent variables. The exclusion of diabetic subjects did not change the results. CONCLUSIONS: The present study of a population-based sample of men and women found inconsistent associations between different insulin measures and IMT after adjustment for the independent variables.

Adult↗

PubMed1998

Morphological changes during early trans-tibial prosthetic fitting.

Morphological changes in the amputation stump may have serious implications regarding the suspension and fit of the prosthetic socket. In an earlier study (Lilja and Oberg, 1997) the authors have shown that the volume of the trans-tibial amputation stump decreases according to a negative power function after amputation, and that the stump volume does not stabilise until four months after the operation. In the present study, Magnetic Resonance Imaging (MRI) technique was used to examine morphological changes in the amputation stump after trans-tibial amputation in a small number of cases. The authors expected to find a decrease in the cross-sectional area of the stump and of the separate muscles similar to the findings in earlier studies. However, two different patterns were found. The cross-sectional area of the entire stump as well as that of the medial muscle group changed according to the authors' hypothesis, i.e. an initial fast decrease, followed by a more moderate decrease of the area. In the lateral muscle group another pattern was found. After an initial rapid decrease the area increased, sometimes to a magnitude larger than the initial value. After the amputation the lateral muscle group may acquire a new function, contributing to the suspension of the socket. Despite the limited number of patients, this study presents findings which may be important in the clinical fitting of trans-tibial prostheses.

Aged↗

PubMed1998

Effect of hypertension, diabetes and other cardiovascular risk factors on kidney size in middle-aged adults.

The aim of the study was to investigate in a population-based series (1031 subjects, age range 40-60 years) whether the renal size of hypertensive subjects differs from that of control subjects and whether the difference might be due to hypertension itself or risk factors associated with hypertension. The renal measurements were performed by abdominal ultrasound. The genders were analyzed separately. Hypertensive men had slightly larger kidneys than controls (70.1+/-8.9 cm2 vs. 67.9+/-8.7 cm2, p <0.008). The difference was, however, mediated mainly through the body mass index (BMI), whereas hypertension, blood pressure or hypertensive medication did not affect renal size. High serum concentrations of uric acid and creatinine were associated with smaller kidney size (p <0.001 and p <0.05, respectively). Alcohol users had slightly larger kidneys than abstainers, but the difference was not significant. Renal size increased with pack years of smoking. Diabetics had 4.8% larger kidneys (p <0.039), but no difference was observed between the subjects with impaired glucose tolerance and those with normal test results. In multivariate analysis, the most significant factors associated with enlarged kidney size were the fasting blood glucose concentration (p < or = 0.0001), smoking (p < or = 0.0001) and atherosclerotic lesions in carotid arteries (p <0.002). The kidneys were also slightly larger in hypertensive women than in control subjects, but the difference was only of borderline significance (p <0.08). Women on hormone replacement therapy had smaller kidneys than other women (p <0.05), but there was no difference in renal measures between premenopausal and postmenopausal women. In multivariate analysis, the most significant factors contributing to large kidney size were blood glucose concentration (p <0.0001) and smoking (p <0.05), while age and serum creatinine concentration were associated with smaller kidney size (p <0.0001 and p <0.0001). We conclude that renal size is related to sex and the subject's height and weight. Smoking, abnormal glucose tolerance, blood uric acid, creatinine, carotid atherosclerosis and hormone replacement therapy in women were also significant factors for renal size. Hypertensive subjects had larger kidneys than controls, mainly because of their more frequent obesity and abnormal glucose test.

Adult↗

PubMed1997

Baroreflex sensitivity in drug-treated systemic hypertension.

Baroreflex sensitivity is impaired in patients with systemic hypertension. The persistence of abnormal baroreflex sensitivity despite adequate blood pressure control may be one of the reasons why the effect of antihypertensive therapy on coronary artery disease mortality has been less than expected on the basis of the achieved blood pressure levels.

Adult↗

PubMed1997

Direct microscopy of effusions obtained from peritonsillar abscesses as a complement to bacterial culturing.

Effusion material was aspirated from 51 consecutive peritonsillar abscesses (34 male, 17 female; age range eight to 46 years) and subjected to direct microscopy after staining with acridine orange. Bacteria were counted per ml effusion material and their morphology was analyzed. In addition, aerobic and anaerobic bacterial culturing was performed. Effusions containing beta-haemolytic streptococci Group A, which appeared as a single species contained fewer bacteria (8 x 10(6) per ml, median value) than effusions harbouring a mixed flora (7 x 10(8) bacteria per ml, median value). Direct microscopy of effusions obtained from peritonsillar abscesses makes possible rapid identification of a single or mixed flora, which is of importance for the antibiotic treatment of the disease.

Acridine Orange↗

PubMed1997

Elderly people's daily activities and need for mobility support.

The aim of the present study is to describe elderly people's performance of some daily activities in relation to their need for mobility support in their living environment. Two groups of individuals, over the age of 65 and living in an old urban area with access to elevators in their housing, were compared, as regards mobility, shopping, hobbies and social contacts. The first group (n = 284) comprised persons who needed assistance from another person in using the elevator. The subjects in the second group (n = 325) were able to manage the elevator independently. The subjects in the first group experienced more problems in carrying out the activities than those in the second group. Weekly shopping was the only action in which the findings demonstrated no main differences between the groups. Throughout all the activities of daily living (ADL), and in both groups, there were persons who were rated as having the capacity to perform the activities, but did not do so and did not want to do so. The elderly, especially in the first group, wanted to engage in more activities than they were judged to have the capacity for and/or the environmental support to do. The implications of the result for the assessment of the homes of the elderly in relation to their environment are discussed.

Activities of Daily Living↗

PubMed1997

Selective attachment of beta-haemolytic streptococci group A to oropharyngeal epithelium in health and disease.

Localization and semiquantification of beta-haemolytic streptococci, Group A (GABHS), GABHS attachment and general bacterial attachment to epithelial cells (bacterial number and morphology) were studied during GABHS-positive acute tonsillitis and pharyngitis infections and among healthy GABHS carriers. Samples were collected from various areas of the oropharynx (palatine tonsils, posterior oropharyngeal wall, palatoglossal arch and buccal mucosa). During acute tonsillitis and pharyngitis, GABHS grew in samples obtained from the palatine tonsils and posterior oropharyngeal wall. The ratio of GABHS colonies to other aerobic colonies increased, and GABHS became attached to epithelial cells of both palatine tonsils and posterior oropharyngeal wall. In GABHS carriers, GABHS were found mainly on the palatine tonsils, but these microorganisms were not attached to the epithelium. Overall bacterial attachment to tonsillar and oropharyngeal epithelial cells increased during active tonsillitis and pharyngitis.

Attachment Sites, Microbiological↗

PubMed1996

Sex-related differences in autonomic modulation of heart rate in middle-aged subjects.

BACKGROUND: Women have worse outcomes when they experience acute myocardial infarction (MI), but the reasons for this sex-related difference are not well understood. Because cardiovascular neural regulation plays an important role in cardiac mortality, we studied possible sex-related differences in the autonomic modulation of heart rate (HR) in middle-aged subjects without known heart disease. METHODS AND RESULTS: Baroreflex sensitivity (BRS) and HR variability were studied in randomly selected, age-matched populations of middle-aged women (n = 186; mean age, 50 +/- 6 years) and men (n = 188; mean age, 50 +/- 6 years) without hypertension, diabetes, or clinical or echocardiographic evidence of heart disease. BRS measured from the overshoot phase of the Valsalva maneuver was significantly lower in women (8.0 +/- 4.6 ms/mm Hg, n = 152) than in men (10.5 +/- 4.6 ms/mm Hg, n = 151) (P < .001), and the low-frequency component of HR variability measured from ECG recordings also was lower in women (P < .001), whereas the high-frequency component was higher in women than in men (P < .001). The ratio between the low-and high-frequency oscillations also was lower in the women (P < .001). The increase of HR and decrease of high-frequency component of HR variability in response to an upright posture were smaller in magnitude in women than in men (P < .01 for both). After adjustment for differences in the baseline-variables, such as blood pressure, HR, smoking, alcohol consumption, and psychosocial score, the sex-related differences in BRS and HR variability still remained significant (P < .001 for all). Women with estrogen replacement therapy (n = 46) had significantly higher BRS and total HR variance than the age-matched women without hormone treatment (P < .01 for both), and the BRS and HR variability of the women with estrogen therapy did not differ from those of the age-matched men. CONCLUSIONS: Baroreflex responsiveness is attenuated in middle-aged women compared with men, but the tonic vagal modulation of HR is augmented. Hormone replacement therapy appears to have favorable effects on the cardiovascular autonomic regulation in postmenopausal women.

Autonomic Nervous System↗

PubMed1996

Heart rate variability in systemic hypertension.

Low heart rate (HR) variability is a risk factor for cardiac mortality in various patient populations, but it has not been well established whether patients with long-standing hypertension have abnormalities in the autonomic modulation of HR. Time and frequency domain measures of HR variability were compared in randomly selected, age-matched populations of 188 normotensive and 168 hypertensive males (mean age 50 +/- 6 years for both). The standard deviation of the RR intervals was lower in the hypertensive subjects than in the normotensive ones (52 +/- 19 vs 59 +/- 20 mss; p <0.01), and the very low and low-frequency spectral components of HR variability analyzed as absolute units were reduced in the hypertensive patients relative to the normotensive controls (p <0.001 for both). Hypertensive subjects also had blunted changes of the normalized low- and high-frequency components in response to an upright (sitting) posture (NS) as compared with normotensive subjects (p <0.001 for both). Multiple regression analysis showed the standard deviation of the RR intervals to be predicted most strongly by systolic blood pressure, both in the patients with hypertension (beta--0.20, p=0.01) and in the normotensive subjects (beta--0.28, p=0.0002). After adjustment for the baseline differences in blood pressure and body mass index, none of the absolute measures of the HR variability or the responses of the normalized units of HR variability to a change in the body posture differed between the hypertensive subjects and normotensive controls. These data show that long-standing hypertension results in reduced overall HR variability and blunted autonomic responses to a change in body posture. Altered autonomic modulation of HR in hypertension is mainly due to elevated blood pressure and obesity in males with long-standing hypertension as compared with normotensive subjects.

Adult↗

PubMed1996

Sex difference in the regulation of plasma high density lipoprotein cholesterol by genetic and environmental factors.

Association between high density lipoprotein (HDL) cholesterol concentration and restriction fragment length polymorphisms at the cholesteryl ester transfer protein (CETP) gene locus was studied in a random population-based cohort of 526 Caucasian subjects (259 men, mean age 50.9 years, and 267 women, mean age 51.8 years). HDL cholesterol concentration was adjusted for age, body mass index, alcohol consumption, smoking and plasma triglyceride and low density lipoprotein cholesterol levels. In females, the HDL cholesterol levels were associated with TaqIB polymorphism (1.46 mmol/l in the B1B1 genotype, 1.56 mmol/l in B1B2 and 1.72 mmol/l in B2B2, P = 0.0001 for the trend). In contrast, this was not observed in men (1.24, 1.20, 1.27 mmol/l, NS). The association was seen even in women who were current smokers (1.41, 1.56, 1.75 mmol/l, n = 72, P = 0.007), but not in male smokers (1.26, 1.19, 1.14 mmol/l, n = 102, NS). In male non-smokers the association was weak (1.22, 1.20, 1.32 mmol/l, n = 157, P = 0.05). In postmenopausal women not receiving hormone replacement therapy (n = 108), the association continued to be present, although weaker (1.50, 1.58, 1.70 mmol/l, P = 0.06). CETP activity (n = 101) tended to be lower in subjects with the B2B2 genotype. In conclusion, a clear-cut sex difference was observed in the genotype effect on plasma HDL cholesterol levels. The slight attenuation of the gene dosage effect after menopause suggests that the gender difference may be, at least in part, due to sex hormones. A genetic subgroup (men with the B2B2 genotype) particularly susceptible to the HDL cholesterol decreasing effect of smoking could be demonstrated.

Adult↗

PubMed1996

Association between angiotensin converting enzyme gene polymorphism and carotid atherosclerosis.

OBJECTIVE: Variations in the angiotensin converting enzyme (ACE) gene have been implicated in cardiovascular pathology. Therefore, the association between the intima-media thickness (IMT) of the carotid artery and the insertion/ deletion (I/D) polymorphism of the ACE gene was investigated. SUBJECTS: Three hundred men and 300 women were selected randomly from the middle-aged population living in the town Oulu, Finland, of whom 515 subjects (85.8%) participated. METHODS: The IMT of the carotid arteries was determined by bilateral B-mode ultrasonography. IMT values were adjusted for gender, age, height, plasma low-density lipoprotein cholesterol level, smoking and systolic blood pressure. The I/D polymorphism of the ACE gene was determined by polymerase chain reaction. RESULTS: Among non-smokers, the subjects with the DD genotype had significantly higher carotid IMT than did those with II or ID. The association was found also in combined IMT plaque values. In the total population the association was weaker and it was absent in current smokers. Genotype could explain 1.3-2.7% of the variance of carotid IMT in non-smokers. No association between the amount or size of carotid plaques and genotype was observed. CONCLUSIONS: Variations at the ACE gene locus contribute to the degree of the early changes in carotid atherosclerosis in the population. The gene effect is, however, masked by stronger effects of environmental factors such as smoking. The lack of association between atherosclerotic plaques and genotypes may reflect different mechanisms being involved in plaque development and early arterial wall thickening.

Adult↗

PubMed1996

Prevalence of carotid atherosclerosis in middle-aged hypertensive and control subjects. A cross-sectional systematic study with duplex ultrasound.

BACKGROUND: Arterial hypertension has been found to increase atherosclerotic lesions, although contradictory results have suggested that hypertension has little or no effect. These discrepancies are probably caused by differences in populations. OBJECTIVE: To examine the effect of hypertension on carotid atherosclerosis in a population-based series of patients with an established diagnosis of arterial hypertension and controls. METHODS: Carotid intima-media thickness (IMT) and plaques were evaluated with duplex ultrasound in 1031 middle-aged (aged 40-60 years) men (n = 511) and women (n = 520), 513 with arterial hypertension and 518 controls. IMT was measured in the internal carotid artery, bifurcation and proximal, middle and distal common carotid artery, determining mean and maximal values for each patient. RESULT: Male sex, age, smoking and cholesterol were the most significant risk factors for combined plaque and intima-media thickness (CPIMT); hypertension and and abnormal glucose test result were further significant risk factors. There was a significant difference in CPIMT between the hypertensive and control subjects, but this was caused by the differences in the men; there were no statistically significant differences among the women. Plaques were found more frequently in the hypertensive men than they were in their controls (62.8 versus 49.8%), the corresponding percentages for the hypertensive and control women being 38.0 and 32.1%. There was a larger proportion of male subjects with a long duration of hypertension (> or = 7 years) who had plaques and greater CPIMT than there was of those with a short duration of hypertension. CONCLUSION: Hypertension had a significant effect on CPIMT and on the prevalence of plaques in men, but its effect in women was not significant. A long duration of hypertension resulted in greater CPIMT values and a higher prevalence of plaques, particularly in men.

Adult↗

PubMed1996

Dispersion of the QT interval and autonomic modulation of heart rate in hypertensive men with and without left ventricular hypertrophy.

Left ventricular hypertrophy is an independent risk factor for sudden cardiac death in hypertension, but the mechanisms of electrical instability associated with hypertrophy are not well known. We studied dispersion of the QT interval, an index of inhomogeneity of repolarization, and heart rate variability, a measure of cardiac autonomic modulation, in a randomly selected population of 162 men with systemic hypertension and made comparisons between the patients with echocardiographic evidence of left ventricular hypertrophy (left ventricular mass index > or = 131 g/m2, n = 44) and those without hypertrophy (left ventricular mass index < 131 g/m2, n = 118). The heart rate-corrected QT dispersion (67 +/- 37 versus 53 +/- 21 milliseconds, P < .05) and QT apex dispersion (55 +/- 22 versus 44 +/- 16 milliseconds, P < .01) were significantly longer in the patients with left ventricular hypertrophy than in those without hypertrophy. Thirteen of the 44 patients (30%) with hypertrophy versus 7 of the 118 patients (6%) without hypertrophy had an abnormally long QT apex dispersion ( > 70 milliseconds) (P < .001). The time and frequency domain measures of heart rate variability did not differ significantly between the patient groups with and without left ventricular hypertrophy. The measures of heart rate variability were not related to QT dispersion or left ventricular mass index but had a negative correlation with blood pressure values (eg, r = -.30 between the low-frequency component of heart rate variability and systolic pressure, P < .001). Age, body mass index, antihypertensive medication, and the other demographic variables were similar between the groups, but the patients with left ventricular hypertrophy had higher systolic (P < .01) and diastolic (P < .01) pressures compared with the patients without hypertrophy. Left ventricular hypertrophy in hypertensive men is associated with inhomogeneity of the early phase of ventricular repolarization, favoring susceptibility to reentrant ventricular tachyarrhythmias. Abnormalities in cardiac autonomic function, which may trigger a spontaneous onset of arrhythmias, are related to elevated blood pressure but not specifically to left ventricular hypertrophy.

Adult↗

PubMed1996

Variation at the angiotensin-converting enzyme gene and angiotensinogen gene loci in relation to blood pressure.

To investigate whether the polymorphisms in the angiotensin-converting enzyme and angiotensinogen genes are associated with hypertension, we carried out a case-control study of 508 hypertensive and 523 control subjects randomly selected from the Social Insurance Institution register. The cohorts were well characterized and matched for age and sex. The insertion/ deletion polymorphism of the angiotensin-converting enzyme gene and the methionine-->threonine variant at position 235 of the angiotensinogen gene were determined by the polymerase chain reaction technique. The allele frequencies and genotype distributions of both polymorphisms were similar in hypertensive and control subjects. Systolic and diastolic pressures adjusted for age, body mass index, and alcohol consumption did not differ significantly between the different genotypes of the angiotensin-converting enzyme and angiotensinogen genes. The variation at the angiotensinogen and angiotensin-converting enzyme genes did not have any statistically significant synergistic effect on blood pressure levels. In conclusion, the polymorphisms in the reninangiotensin cascade genes do not confer a significantly increased risk for the development of hypertension in this middle-aged, population-based cohort.

Adult↗

PubMed1995

Volumetric determinations with CAD/CAM in prosthetics and orthotics: errors of measurement.

During the next decade CAD/CAM technique will probably become routine in prosthetics and orthotics, not only as a complement to manual techniques, but also introducing new possibilities. However, even complex and sophisticated techniques have errors of measurement that must be considered. Such errors are of two principal kinds: systematic errors and random errors. In this study we have evaluated the Swedish CAPOD system with respect to volumetric determinations. We used two types of reference objects for volume determinations: cylinders and amputation residual limb models. Three different sizes were examined of each type of object. Volume measurements with CAPOD were compared with volumes obtained by water immersion or mathematical calculation (cylinders only). We found a constant, linear systematic error of +2.5%. Such an error can easily be corrected for. The random error, represented by the coefficient of variation, was 0.5%, which means that there is a theoretical possibility to detect volume changes exceeding 1%. We consider the precision sufficient for clinical practice in prosthetics and orthotics. Biological variations due to soft tissue deformation must be added on top of these errors. Such deformations were not evaluated in this study.

Artificial Limbs↗

PubMed1994

Effects of early administration of enalapril on radionuclide left ventricular ejection fraction and plasma N-terminal atrial natriuretic peptide after acute myocardial infarction.

The effects of enalapril therapy on radionuclide ejection fraction and plasma N-terminal atrial natriuretic peptide were investigated in a randomized, double-blind, placebo-controlled study of 52 patients with acute myocardial infarction. The medication was begun intravenously within 24 hours of the onset of symptoms. At discharge and the end point of 6 months, the radiographic size of the heart was significantly smaller in patients receiving (n = 28) than in those not receiving (n = 24) enalapril therapy (p < 0.03 vs < 0.01). However, left ventricular ejection fraction decreased simultaneously from 50 +/- 10% to 47 +/- 11% in patients treated with enalapril, whereas it increased from 48 +/- 13% to 50 +/- 14% in control patients (p < 0.05 for the difference of the changes). The decrease in ejection fraction was most marked in the infarct-related region of the left ventricle (p < 0.01). During the in-hospital period, plasma N-terminal atrial natriuretic peptide was decreased in patients treated with enalapril, whereas it was increased in those treated with placebo with complicated acute myocardial infarction (p < 0.05). During the following 6 months, the differences remained insignificant. Early administration of enalapril significantly attenuated heart enlargement after myocardial infarction and probably improved hemodynamics during the acute phase of complicated infarction. The decrease in ejection fraction during recovery indicates an impairment of systolic function. The decrease in infarct-related regional ejection fraction suggests that the impairment may be due to poor healing of the infarction scar.

Aged↗