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Biomedical subjects

L Nyström

Publications and source records attributed to L Nyström.

At least 55 records · Page 3Linked to original sources
PubMed2001

Combinations of beta cell specific autoantibodies at diagnosis of diabetes in young adults reflects different courses of beta cell damage.

To explore the natural course of beta cell function in recent onset diabetes, a subgroup (n=157) of all incident cases (n=879) 15-34 years old, 1992-1993 in Sweden, and with positivity for at least one autoantibody of islet cell antibodies (ICA), glutamic acid decarboxylase antibodies (GADA) or tyrosine phosphatase antibodies (IA-2A) were followed prospectively for the first four years with annual analysis of C-peptide. The aim was to relate the course of beta cell function, measured as C-peptide, in early diabetes with the presence of different islet autoantibodies at diagnosis. We found that patients positive for ICA alone (n=11) had significantly higher C-peptide levels both at diagnosis and during the first three years compared with the other patients (n=146; p=0.022, p<0.001, p=0.004 and p=0.0022). Patients positive for GADA alone or in combination with other antibodies (n=125) had significantly lower C-peptide during the first three years after diagnosis compared with the other patients (n=32, p<0.001, p=0.0011 and p=0.0136). Patients with two or three autoantibodies had C-peptide levels similar to levels found in patients positive only for GADA. However, after four years, there were no significant differences between any of the groups of different autoantibody combinations. At diagnosis, 55% (86/157) of the patients had C-peptide levels above the lower normal range of 0.25 nmol/l, but the frequency of patients with beta cell function above this level decreased after two years to 41% (65/157; p=0.035) and after four years to 22% (35/157; p=0.0041). It is concluded that young adult diabetic patients positive only for ICA at diagnosis have a better preserved beta cell function with higher levels of C-peptide during the first three years compared with patients positive for GADA alone or in combinations with other autoantibodies.

Adolescent↗
PubMed2001

Prevalence of multiple sclerosis in Västerbotten County in northern Sweden.

OBJECTIVE: To estimate the prevalence and clinical characteristics of multiple sclerosis (MS) in Västerbotten County in northern Sweden. METHODS: Individuals with MS were identified from several sources. A follow-up interview and/or examination was performed in 94% of cases still living in the area during 1997-99. Onset adjusted prevalence and a definition of onset symptoms were applied. RESULTS: A total of 313 cases were identified, resulting in an onset adjusted crude prevalence of MS for January 1990 of 125/105 (95% confidence interval (CI): 112-140). Female predominance was evident (163/105 (95% CI: 142-187) vs 86/105 (95% CI: 71-104)). Diagnostic coding registers were the most important source for identification of cases. CONCLUSIONS: The crude prevalence of MS in Västerbotten was higher than previous reports from other major areas in Scandinavia. The adjusted prevalence was significantly higher when compared with a previous study from Göteborg, south-western Sweden. The methodology used in this study gives a high degree of case ascertainment and increases the comparability of multiple sclerosis epidemiological studies.

Adolescent↗
PubMed2001

Intrauterine infection may be a major cause of stillbirth in Sweden.

AIM OF THE STUDY: To investigate intrauterine infection as a cause for unexplained stillbirth. METHODS: Chorioamnionitis was studied in a material of stillbirths (117 subjects from the years 1985-1994) from a region in the south Sweden. Control material (126 alive and healthy newborns and with healthy mothers) was gathered from the same region. RESULTS: Chorioamnionitis was a common diagnosis both with stillbirths and 'healthy' deliveries (82 and 68%, respectively). Extension of the inflammation to decidua basalis was seven times more common among stillbirths than among controls (odds ratio 7.2, confidence interval 2.8-21.9). The most common bacteria found at cultures were Escherichia coli, Coagulase negative staphylococcus, Enterococcus faecalis and group B Streptococcus. The risk for stillbirth was doubled if both inflammation and bacteria were present (odds ratio 2.3, confidence interval 0.92-5.8). Meconium discharge was more common among stillbirths than controls (odds ratio=4.7, confidence interval 1.7-14). There were no differences in any respect regarding macerated and non-macerated stillbirths. Our findings are similar to the results from studies in developing countries except for the higher incidence of stillbirths in such countries. CONCLUSIONS: Thus, a large part of otherwise unexplained stillbirths might be due to ascending infections.

Adult↗
PubMed2001

Sociodemographic predictors of self-rated health in patients with diabetes of short duration.

AIMS: To examine the impact of gender and socioeconomic factors on health-related quality of life (HRQoL) one year and eight years after diabetes diagnosis. METHODS: Two national incidence cohorts who contracted diabetes between the ages of 15 and 34 years (n=554) and matched control groups from the general population of Sweden (n=1,029) were surveyed. Data on HRQoL, diabetes treatment, marital status, education, social class, and employment were collected via a questionnaire mailed to the younger cohort (aged 16-35) one year after diagnosis and to the older cohort (aged 23-42) eight years after diagnosis. Response rates were 73% among people with diabetes and 68% among the controls. Multivariable linear regression models were used to analyse the impact of gender and socioeconomic factors on HRQoL in the diabetic and control groups. The dependent variable was the "general health perceptions" score of the SWED-QUAL instrument, which corresponds to the "global self-rated health" concept. RESULTS: A model including all the sociodemographic variables explained 6% of the variance in self-rated health one year after diabetes diagnosis and 13% of the variance eight years after diagnosis. In the control groups, the level of explanation was 2-3%. Female gender was an independent predictor of poor self-rated health in the older diabetic cohort, but not in the younger cohort. CONCLUSIONS: Gender and socioeconomic factors were more closely associated with self-rated health eight years after diabetes diagnosis than one year after diagnosis, indicating early sociodemographic stratification in the health of the diabetic populations studied.

Adolescent↗
PubMed2000

Excess costs of medical care 1 and 8 years after diagnosis of diabetes: estimates from young and middle-aged incidence cohorts in Sweden.

To analyze the excess costs of medical care during the first decade after diabetes diagnosis, we surveyed two national incidence cohorts who contracted diabetes at age of 15-34 years and matched control groups from the general population of Sweden. Ninety percent of the diabetic subjects were on insulin treatment. Data on healthcare utilization and use of glucose lowering drugs and medical devices were collected via a questionnaire mailed to a recent cohort 1 year after diagnosis and a previously registered cohort 8 years after diagnosis. Costing was based on average national costs of hospital inpatient and out-patient care, an original study of daycare costs, and sales prices of the National Corporation of Swedish Pharmacies. One year after diabetes diagnosis, the annual excess costs of care were US$4743 among men and US$4976 among women (1997 prices). Hospital inpatient care accounted for more than 50% of the excess costs. Eight years after diagnosis, the excess costs were US$2010 among men and US$2734 among women. The higher costs for women were mainly related to hospital out-patient care, but also to more intensive self-monitoring. We conclude that diabetes in young and middle-aged people is a major economic challenge even before significant complications may have developed.

Adolescent↗
PubMed2000

Ketoacidosis in young adults is not related to the islet antibodies at the diagnosis of Type 1 diabetes mellitus--a nationwide study.

AIMS: To test the hypothesis that there is lower prevalence of islet antibodies in subjects with newly diagnosed Type 1 diabetes mellitus in young adulthood than in children is associated with less severe diabetes at time of diagnosis. METHODS: This investigation was based on a nationwide study (Diabetes Incidence Study in Sweden) of 15-34-year-old newly diagnosed diabetic subjects. During 1992-1993, all diabetic subjects (excluding secondary and gestational diabetes) were reported on standardized forms, with information about clinical characteristics at diagnosis. The study examined islet cell antibodies (ICA) by indirect immunofluorescence, and autoantibodies to glutamic acid decarboxylase (GADA), tyrosine phosphatase-like antigen (IA-2A) and insulin (IAA) as well as C-peptide by radioimmunoassay. RESULTS: Blood samples were available from 78 patients with diabetic ketoacidosis (DKA) and 517 non-acidotic patients. The prevalence of ICA (63% vs. 57%), GADA (63% vs. 66%), IA-2A (35% vs. 44%) and IAA (20% vs. 15%) were very similar in patients with or without DKA. The median levels of the four autoantibodies did not differ between the two groups. High blood glucose (P < 0.001) and low C-peptide levels (P < 0.001) were the only parameters found to be related to DKA. CONCLUSIONS: The similarities in findings of newly diagnosed diabetic patients with or without DKA regarding ICA, GADA, IA-2A and IAA suggest that there is no relationship between the expression of antigenicity and the severity of beta-cell dysfunction. The lower prevalence of the four autoantibodies in 15-34-year-old diabetic subjects compared with previous findings in children is not explained by misclassification of diabetes type.

Adolescent↗
PubMed2000

Service screening with mammography in Sweden--evaluation of effects of screening on breast cancer mortality in age group 40-49 years.

The aim of the study was to develop a model for estimating the effect of the nation-wide service screening program with mammography on breast cancer mortality in Sweden. In 1997, the introduction of population-based service screening had been completed in all 26 counties. In approximately half of the counties suitable for evaluation, the lower age limit for invitation was 40 years (study population) and in the other half the age limit was 50 years (control population). The numbers of females aged 40 49 years for the two populations were 202,152 and 237,279, respectively (1988). The study and control populations were compared for the period 1986-1996 with regard to refined breast cancer mortality. To adjust for geographical differences, the period 1976 1986 was used as reference. With a mean follow-up time of 8 years, the estimated relative risk of breast cancer death in relation to invitation to service screening among women aged 40-49 years at breast cancer diagnosis was 0.91 (95% confidence interval 0.72-1.15). These findings were compatible with those presented in the previous overview of the Swedish randomized studies.

Adult↗
PubMed2000

Epidemic of coeliac disease in Swedish children.

Coeliac disease has emerged as a public health problem. The aim of the present study was to analyse trends in the occurrence of symptomatic coeliac disease in Swedish children from 1973 to 1997, and to explore any temporal relationship to changes in infant dietary patterns. We established a population-based prospective incidence register of coeliac disease in 1991, and, in addition, retrospective data from 1973 were collected. A total of 2151 cases fulfilled the diagnostic criteria. Furthermore. We collected national data on a yearly basis on duration of breastfeeding, intake of gluten-containing cereals and recommendations on when and how to introduce gluten into the diet of infants. From 1985 to 1987 the annual incidence rate in children below 2 y of age increased fourfold to 200-240 cases per 100000 person years, followed from 1995 by a sharp decline to the previous level of 50-60 cases per 100000 person years. This epidemic pattern is quite unique for a chronic disease of immunological pathogenesis, suggesting that prevention could be possible. The ecological observations made in this study are compatible with the epidemic being the result, at least in part, of a change in and an interplay among three factors within the area of infant feeding, i.e. amount of gluten given, age at introduction of gluten, and whether breastfeeding was ongoing or not when gluten was introduced. Other factor(s) may also have contributed, and the search for these should be intensified.

Adolescent↗
PubMed2000

Mortality risk in an adult cohort with a newly diagnosed unprovoked epileptic seizure: a population-based study.

PURPOSE: We sought to investigate mortality risk in an adult cohort with newly diagnosed unprovoked epileptic seizures. METHODS: One hundred seven patients who were at least 17 years old and had newly diagnosed unprovoked epileptic seizures were prospectively identified during a period of 20 months between 1985 and 1987. Patients were followed until the date of death or the end of 1996. The standard mortality ratio (SMR) was analyzed in the whole cohort and in the portion of the cohort with recurrent seizures at inclusion. The influences on the SMR of time since diagnosis, sex, age at diagnosis, seizure cause, seizure type, and cause of death were also investigated. RESULTS: The SMR was significantly increased (SMR, 2.5; 95% confidence interval [CI], 1. 2-3.2). This significantly increased risk was found during the first 2 years after diagnosis (year 1: SMR, 7.3; 95% CI, 4.4-12.1; year 2: SMR, 3.6; 95% CI, 1.6-8.1) and at years 9-11 (SMR, 5.4; 95% CI, 2. 7-11.2). The increased mortality risk was most pronounced when the seizures occurred before the age of 60 years. Mortality risk was elevated among patients with remote symptomatic epilepsy (SMR, 3.3; 95% CI, 2.4-4.5) but not idiopathic epilepsy. CONCLUSIONS: There is increased mortality risk in an adult cohort with newly diagnosed unprovoked epileptic seizures. This increase is found in symptomatic patients, young patients, and during the first 2 years after the diagnosis.

Adolescent↗
PubMed2000

Prognostic factors for the course of beta cell function in autoimmune diabetes.

This study presents a 2-yr follow-up of 281 patients, aged 15-34 yr, diagnosed with diabetes between 1992 and 1993. At diagnosis, 224 (80%) patients were positive for at least one of the following autoantibodies: islet cell antibodies (ICAs), glutamic acid decarboxylase antibodies (GADAs), or tyrosine phosphatase antibodies (IA-2As); the remaining 57 (20%) patients were negative for all three autoantibodies. At diagnosis, C-peptide levels were lower (0. 27; 0.16-0.40 nmol/L) in autoantibody-positive patients compared with autoantibody-negative patients (0.51; 0.28-0.78 nmol/L; P: < 0. 001). After 2 yr, C-peptide levels had decreased significantly in patients with autoimmune diabetes (0.20; 0.10-0.37 nmol/L; P: = 0. 0018), but not in autoantibody-negative patients. In patients with autoimmune diabetes, a low initial level of C-peptide (odds ratio, 2. 6; 95% confidence interval, 1.7-4.0) and a high level of GADAs (odds ratio, 2.5; 95% confidence interval, 1.1-5.7) were risk factors for a C-peptide level below the reference level of 0.25 nmol/L 2 yr after diagnosis. Body mass index had a significant effect in the multivariate analysis only when initial C-peptide was not considered. Factors such as age, gender, levels of ICA or IA-2A or insulin autoantibodies (analyzed in a subset of 180 patients) had no effect on the decrease in beta-cell function. It is concluded that the absence of pancreatic islet autoantibodies at diagnosis were highly predictive for a maintained beta-cell function during the 2 yr after diagnosis, whereas high levels of GADA indicated a course of decreased beta-cell function with low levels of C-peptide. In autoimmune diabetes, an initial low level of C-peptide was a strong risk factor for a decrease in beta-cell function and conversely high C-peptide levels were protective. Other factors such as age, gender, body mass index, levels of ICA, IA-2A or IAA had no prognostic importance.

Adolescent↗
PubMed2000

A community based study of HIV in women in rural Gutu District, Zimbabwe 1992 to 1993.

OBJECTIVE: To estimate the prevalence of HIV-1 infection and its relation to socio-economic and obstetric history factors. DESIGN: A cross sectional study. SETTING: 12 randomly selected villages in rural Gutu District, Zimbabwe. SUBJECTS: All women of fertile age (15 to 44 years) in the selected villages were invited to participate. In total 1,213 women were interviewed and examined. On average 75% and 81% of those eligible in 1992 and 1993 respectively participated (range for villages 57 to 87%). MAIN OUTCOME MEASURES: HIV sero-positivity. RESULTS: HIV prevalence was high, 21.9%. Single women below 20 years had the lowest prevalence (7.6%), while the highest (30.0%) was found in married women aged 20 to 29 years. Using a case-referent approach, women divorced, widowed or separated had twice as high a risk of being HIV positive as single women (Odds Ratio (OR) = 2.03; 95% confidence interval (CI) 1.40 to 2.93). There was a huge difference in the prevalence of HIV between villages, from 8.4 to 32.8%, thus the risk of having HIV in the two villages with the highest prevalence was more than five times higher (OR = 5.21 and 5.31 respectively) than in the village with the lowest. The multivariate logistic regression confirmed the findings of an increased risk for women aged 20 to 39 years as compared with women 15 to 19 years, and for women that were divorced, widowed or separated as compared with single. It also confirmed that the huge difference in the prevalence found between wards was statistically significant. CONCLUSION: Women contract HIV early in marriage. Young men's risk behaviour needs to be addressed and women must be aware of their risks before marriage.

Adolescent↗
PubMed1999

Purification of recombinant and human apolipoprotein A-1 using surfactant micelles in aqueous two-phase systems: recycling of thermoseparating polymer and surfactant with temperature-induced phase separation.

An effective system has been developed for purification of apolipoprotein A-1 from Escherichia coli fermentation solution and human plasma using aqueous two-phase extraction and thermal-phase separation. The system included non-ionic surfactants (Triton or Tween) and as top phase-forming polymer a random copolymer of ethylene oxide (50%) and propylene oxide (50%), Breox PAG 50A 1000, was used. The bottom phase-forming polymer was either hydroxypropyl starch, Reppal PES 100 and PES 200, or hydroxyethyl starch, Solfarex A 85. The top-phase-forming polymer and the surfactants are thermoseparating in water solution, i.e., when heated a water phase and a polymer/surfactant phase are formed. Recombinant apolipoprotein A-1, the Milano variant, was extracted from E. coli fermentation solution in a primary Breox-starch phase system followed by thermal separation of the Breox phase where the target protein was recovered in the water phase. Both in the Breox-starch system and in the water-Breox system Triton X-100 was partitioned to the Breox phase. The addition of non-ionic surfactants to the Breox-starch system had strong effect on the purification and yield of the amphiphilic apolipoprotein A-1. In a system containing 17% Breox PAG 50A 1000, 12% Reppal PES 100 and addition of 1% Triton X-100 the purification factor was 7.2, and the yield 85% after thermal separation of the Breox phase. Recycling of copolymer and surfactant was possible after thermal separation of copolymer phase. Approximately 85% of the copolymer and surfactant could be recycled in each extraction cycle. DNA could be strongly partitioned to the starch phase in the primary-phase system. This resulted in a 1000-fold reduction of E. coli DNA in the apolipoprotein A-1 solution obtained after thermoseparation. In extraction from human plasma containing low concentrations of apolipoprotein A-1, it was possible to reach a purification factor of 420 with 98% yield. By reducing the volume ratio to 0.1 Apo A-1 could be concentrated in a small volume of top phase (concentration factor 10) with a yield of 85% and a purification factor of 110.

Apolipoprotein A-I↗
PubMed1999

Non-responders to a postal questionnaire on respiratory symptoms and diseases.

Only few data have been published about non-responders in epidemiological studies on respiratory diseases. The aim of this study was to examine the characteristics of the non-responders and the reasons for non-response in a survey of respiratory health. All 9132 subjects, born 1925-1926, 1940-1941, 1955-1956 and 1970-1971 and living in eight representative areas in Norrbotten, Sweden, were invited to a prevalence study on asthma, chronic bronchitis and respiratory symptoms. The response rate was 85%. A sample of the non-responders from the cross-sectional postal questionnaire study was contacted by telephone and interviewed using the same questionnaire as had been used in the postal survey. Of the 1397 non-responders a stratified sample of 182 subjects were selected for this study and 144 agreed to participate. The response rate was increasing by increasing age. The main reason for non-response was that the subjects had forgotten to mail the questionnaire, lack of interest or lack of time. There were significantly higher proportions of current smokers and manual workers among the non-responders. The prevalence rates of wheezing, long-standing cough, sputum production, attacks of breathlessness, asthma and use of asthma medicines were significantly higher among the non-responders compared with the responders according both univariate and multivariate logistic regression analyses, in which the influences of age, sex, smoking habits, socioeconomic group and area of domicile were taken into account. The prevalence of respiratory symptoms and diseases was slightly underestimated in the postal survey.

Adult↗