PubMed HealthSearch

Biomedical subjects

L Nyström

Publications and source records attributed to L Nyström.

At least 19 recordsLinked to original sources

Improved method for the determination of 5,6-dihydroxytryptamine and 5,7-dihydroxytryptamine in tissue using high-performance liquid chromatography with electrochemical detection.

A liquid chromatographic method with electrochemical detection is described for the determination of the 5-hydroxytryptamine (5-HT) neurotoxins 5,6-dihydroxytryptamine (5,6-DHT) and 5,7-dihydroxytryptamine (5,7-DHT) in rat brain tissue. This method has also been used for the determination of 5-hydroxyindoleacetic acid, homovanillic acid and 5-HT in other tissue samples. The method is based on extraction of the indoles from brain samples with perchloric acid followed by reversed-phase liquid chromatography with electrochemical detection. The detection limit is 1 ng per 100 mg of tissue. This paper describes a quick and reliable method of assaying the 5-HT neurotoxins 5,6-DHT and 5,7-DHT in brain tissue, which is improved compared to currently available assays.

5,6-Dihydroxytryptamine

Male predominance of type 1 (insulin-dependent) diabetes mellitus in young adults: results from a 5-year prospective nationwide study of the 15-34-year age group in Sweden.

The incidence of diabetes mellitus in Sweden in the 15-34 year age group was prospectively studied on a nationwide basis, beginning 1 January 1983. A total of 1,214 male and 720 female cases of newly-diagnosed (excluding gestational) diabetes were reported over a 5-year period. This corresponds to an incidence of 20.5 per 100,000/year in male subjects and 12.7 per 100,000/year in female subjects. Most cases were classified as Type 1 (insulin-dependent) diabetes, with an incidence of 15.9 in males and 8.6 in females. The incidence of Type 1 diabetes decreased gradually with age, while the incidence of Type 2 (non-insulin-dependent) diabetes increased. A male predominance was found in all age groups, with a male-to-female ratio of 1.8:1 for Type 1 diabetes and 1.3:1 for Type 2 diabetes. Maximum blood glucose concentration at diagnosis was significantly higher in males than in females in both Type 1 and Type 2 diabetic subjects. In contrast, the percent desirable weight was significantly higher in females, both in Type 1 and Type 2 diabetic subjects. The difference in diabetes incidence therefore cannot be attributed to any methodological error. The present finding of a marked male predominance after puberty in Type 1 diabetes in an ethnically quite homogeneous population supports the hypothesis that environmental risk factors and life-style are important for the development of the disease.

Adolescent

Predictive value of islet cell and insulin autoantibodies for type 1 (insulin-dependent) diabetes mellitus in a population-based study of newly-diagnosed diabetic and matched control children.

Most studies evaluating immune markers for prediction of Type 1 (insulin-dependent) diabetes mellitus have focused on first degree relatives, although only 10% of newly-diagnosed patients have an affected first degree relative. The Swedish Childhood Diabetes Register identifies 99% of all diabetic children at diagnosis. In this population-based study, islet cell antibodies and insulin autoantibodies in 0-14-year-old Swedish consecutively-diagnosed patients and control subjects were analysed to define their sensitivity and specificity. Over 16 months (1986-1987), 515 Swedish children developed diabetes. Plasma samples were obtained from 494 (96%) patients, and 420 matched control children. Among patients, the frequency of islet cell antibodies was 84% (415 of 494), insulin autoantibodies 43% (145 of 334); 40% (135 of 334) were positive for both and 88% (294 of 334) were positive for one or both. Among control children, 3% (14 of 420) had islet cell antibodies, 1% (4 of 390) insulin autoantibodies, and 4% (16 of 390) had either autoantibody marker. The predictive value of finding a patient with the disease was only 7% since 4% of the control children were antibody-positive and the cumulative incidence rate up to 15 years of age is 0.38%. None of the autoantibody-positive (n = 21) or negative control children developed diabetes during 3 to 5 years of follow-up. Longitudinal investigations of islet cell or insulin-autoantibody-positive healthy children are necessary to accurately determine the conversion rate from marker positivity to disease onset.

Adolescent

Risk of developing insulin-dependent diabetes mellitus (IDDM) before 35 years of age: indications of climatological determinants for age at onset.

This study analyses data from two nationwide prospective diabetes registries now covering about 3400 cases from 19 million person-years of follow-up in the age group 0-34 years. The risk of developing insulin-dependent diabetes mellitus (IDDM) per 100,000 individuals before 15 years was 386 (95% confidence intervals (CI): 362-410) for boys and 391 (95% CI: 367-415) for girls and by 35 years 701 (95% CI: 671-731) for men and 562 (95% CI: 534-690) for women. The incidence rate showed a maximum for both boys and girls in early puberty. After pubertal years a sharp increase in the male to female incidence ratio of IDDM was notable. At 10-14 years it was 0.94, at 15-19 years 1.59 and at 20-24 years 2.08. A Cox regression model was used to analyse the effects on age at onset of sex, population density and climatological factors as measured by north-south area of residence and season at onset. The effect of sex was confirmed (P less than 0.001). A significant effect (P = 0.004) of season was shown when the four seasons were classified according to a four stage scale related to mean temperature. When dividing Sweden into 11 regions according to north-south gradient (Latitude 55 degrees, 56 degrees, 57 degrees, ..., 65 degrees) a significant effect (P = 0.038) was also found. However, no effects of population density or living near the coast versus in the interior were found. It is concluded that a large proportion of the young are at risk of developing this chronic disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

Mortality of all incident cases of diabetes mellitus in Sweden diagnosed 1983-1987 at age 15-34 years. Diabetes Incidence Study in Sweden (DISS) Group.

From 1983 all incident cases of diabetes in the age group 15-34 years in Sweden have been recorded prospectively. The aim of the present study was to assess the mortality pattern of cases reported for 1983-87 and followed until the end of 1987. Eighteen deaths were identified by linkage to the national death register. When comparing the mortality in the cohort with Swedish males and females in general, an excess mortality was found in all the groups studied. It is, however, less pronounced if the analysis is restricted to those with Type 1 diabetes (standardized mortality ratio (SMR) and 95% confidence interval = 2.1; 0.8, 4.6), Type 2 diabetes (SMR = 4.8; 1.3, 12.3) or Type 1 + Type 2 (SMR = 2.7; 1.3, 5.0). Eight (44%) of the deaths were in patients with secondary diabetes, a diagnosis that applied to less than 3% of the cohort. Alcohol abuse was prevalent in six cases and suspected in another two. Hypoglycaemia was established as a cause of death in only one case but could not be excluded in a further six. Only one death was associated with ketoacidosis. No valid support for an increased risk of the 'dead in bed' syndrome was found. We suggest that diabetes was decisively important for the death in two cases and less important in 10. In the remaining six cases the existing documentation precludes a proper judgement.

Adolescent

The Swedish childhood diabetes study. Vaccinations and infections as risk determinants for diabetes in childhood.

In a nationwide incident case referent study we have evaluated vaccinations, early and recent infections and the use of medicines as possible risk determinants for Type 1 (insulin-dependent) diabetes mellitus in childhood. A total of 339 recently onset diabetic and 528 referent children, age 0-14 years, were included. Information about infections was collected from a mailed questionnaire and about vaccinations from childhood health care centres and schools. When vaccinations were considered as possible risk factors for diabetes, a significant decrease in relative risk estimated as odds ratio (OR) was noted for measles vaccination (OR = 0.69; 95% confidence limits 0.48-0.98). For vaccination against tuberculosis, smallpox, tetanus, whooping cough, rubella and mumps no significant effect on OR for diabetes was found. The odds ratios for Type 1 diabetes for children exposed to 0.1-2 or over 2 infections during the last year before diagnosis of diabetes revealed a linear increase (OR = 1.0, 1.96 and 2.55 for 0, 1-2 and over 2 infections, respectively). The trend was still significant when standardized for possible confounders such as age and sex of the children, maternal age and education and intake of antibiotics and analgetics. In conclusion, a protective effect of measles vaccination for Type 1 diabetes in childhood is indicated as well as a possible causal relationship between the onset of the disease and the total load of recent infections.

Adolescent

The Swedish Childhood Diabetes Study: a seven-fold decrease in short-term mortality?

Since 1 July 1977 all Swedish children aged 0-14 years with newly diagnosed Type 1 diabetes have been recorded on a central register. Out of 3228 patients registered up to 31 December 1985, 10 children (seven boys) had died during this time period. The overall mortality was 0.75 per 1000 patient-years. When compared with the general population the standardized mortality ratio (SMR) for both sexes was 2.09 (95% confidence limits 1.14-3.83). When analysed separately for sex, the higher mortality remained significant for males only (SMR = 2.61, 1.28-5.32). Five deaths were most probably due to diabetes and the remaining five were due to accidents, other diseases and, in one case, not identifiable with certainty. In comparison with previous studies there was a very low mortality in young-onset diabetic patients. However, short-term mortality is still significantly raised even in a country with a good economic and educational patient status and easy access to free hospital care.

Accidents

Pre- and perinatal factors in febrile convulsions.

In a community based study, 110 children with febrile convulsions (FC) were identified prospectively. Pre- and perinatal risk factors were compared with 213 age and sex matched controls sampled from the community. During pregnancy, proteinuria and preeclampsia/eclampsia occurred more often in mothers of cases. Premature birth and bilirubinemia greater than 200 mumol/l were also more common in cases. There were no differences between cases and controls in occurrence of chronic illnesses in mothers, parents age at birth, birth order, and factors occurring during delivery such as type of anesthesia, occurrence of acute or elective cesarean section, use of vacuum extraction, mode of presentation, signs of fetal distress in amnion fluid, umbilical problems, abnormalities of fetal heart rate or duration of delivery. Perinatal asphyxia was uncommon and there was no difference between cases and referents. Occurrence of complications during the first neonatal week did not differ between groups.

Bilirubin

Mortality in circulatory diseases, especially ischaemic heart disease, among Swedish professional drivers: a retrospective cohort study.

The aim of the investigation was to study mortality from circulatory diseases, especially ischaemic heart disease (IHD), in a cohort of Swedish professional drivers. The cohort included 1,731 male members of the Swedish Transport Workers Union. During the follow-up period, 1974-1985, 123 drivers died. Information concerning the cause of death was acquired from the Cause-of-Death Register. Standardized Mortality Ratio (SMR) for circulatory diseases and ischaemic heart disease were significantly higher among professional drivers (SMR = 127 and 138, respectively) than in the reference group consisting of Swedish males.

Adolescent

Obstructive lung disease in northern Sweden: respiratory symptoms assessed in a postal survey.

The prevalence of respiratory symptoms in 6,610 adults (3,372 men and 3,238 women); 35-36, 50-51 and 65-66 yrs of age, living in selected areas of Norrbotten, northern Sweden, were assessed in a postal survey. Response rates were identical in men and women, and at least one respiratory symptom was reported by 41% of each sex. Twenty two percent reported sputum production, and 14% reported wheezing. Despite differences in smoking habits and in the different age groups, the prevalence of symptoms did not differ between the sexes, or between urban and rural areas. Symptoms were as common in people living in the rural interior as in the industrialized coastal area. Present or past history of asthma was reported by 323 (5.9%) subjects, whilst 234 (4.1%) subjects stated that they had chronic bronchitis or emphysema. Less than half of the subjects who reported attacks of breathlessness together with wheezing stated that they had at any time had asthma. Whilst the exact prevalence of had asthma. Whilst the exact prevalence of at any time had asthma and chronic bronchitis cannot be assessed from this postal survey, its results indicate that the prevalence of asthma may be higher in northern Sweden than has been reported from the south of Sweden.

Adult

An incident case-referent study of febrile convulsions in children: genetical and social aspects.

In a prospective community-based study of 103 children with febrile convulsions (FC), social and genetical factors were compared with 193 age and sex matched referents sampled from the community. FC were found more often among parents of cases than referents (odds ratio 21.0; p less than 0.001). A history of FC in any type of relative was found in 39.8% of cases and 10.4% of referents (odds ratio 5.8; p less than 0.001). The familial occurrence of FC is best described by a multifactorial (polygenic) model. No difference was found between groups in the occurrence of other diseases than FC affecting the central nervous system and only one case was mentally retarded. No difference was found between cases and referents in the age of independent walking and ability to speak at age 18 months. Children with FC more often had infectious diseases than referents (odds ratio 2.84; p = 0.002). Children with FC more often lived in apartments and spent their time in day by day care institutions (odds ratio 2.91; p = 0.02). Parents' occupation did not differ between groups. Mothers of children with FC more often had compulsory education only compared with mothers of referents.

Child

The Swedish childhood diabetes study. An analysis of the temporal variation in diabetes incidence 1978-1987.

The Swedish Childhood Diabetes Register combines continuous prospective reporting on incident cases and regular retrospective review of hospital records in all paediatric departments in the country and has, from 1978 to 1987, compiled 3838 cases. A validity test using an independent source has revealed a degree of ascertainment of 100%. When fitting a linear regression model to the natural logarithm of the yearly incidence rates, a significant increase over time was found for girls and for both sexes combined. To analyse the time trend with respect to age, sex, calendar year and birth cohort and their interactions, Poisson regression modelling was used. There was a significant age effect and interaction between age and sex. When these age and sex effects were taken into account a significant increase over time was found. Calendar period had a significant effect when adjusted for cohort effects whereas cohort did not add significantly to the explanation of the variance. There was no significant interaction between sex and calendar period indicating similar time variations for both sexes. The temporal variability was also apparently similar among different age groups. The observed increase of childhood insulin-dependent diabetes mellitus (IDDM) affecting both sexes and all age groups, strongly supports the importance of environmental factors in the aetiology of IDDM.

Adolescent

Prevalence and characteristics of persons with dependency on feeding at institutions for elderly.

The prevalence of dependency on feeding was estimated in 3,607 residents cared for in old people's homes, nursing homes, somatic long-stay clinics, psychiatric long-stay wards and psychogeriatric wards. Ten per cent of the residents were found to be dependent on the staff to eat. The highest proportion was found in nursing homes and somatic long-stay clinics. A considerably larger proportion of the residents with dependency on assisted feeding imposed the highest workload on the staff. Residents who were totally dependent on assisted feeding were more disabled with regard to other ADL functions and also they were demented more often. Loss of the ability to eat was related to an inability in other ADL functions. Support was gained for a hierarchical loss of ADL functions as suggested by Katz & Apkom. Feeding problems seem to be a terminal phenomenon in demented patients.

Activities of Daily Living

Mortality from circulatory diseases, especially ischaemic heart disease in sea pilots and boatmen in Sweden 1951-84: a retrospective cohort study.

A cohort of 1455 sea pilots and boatmen employed after 1921 was established. Those identified and alive in 1951 (n = 1323) were linked to the Swedish cause of death register 1951-84. In 21 352 person-years 383 deaths were observed among sea pilots compared with 379.3 expected (SMR = 101;95% CI between 99 and 112) and in 12,127 person-years the observed number of deaths among boatmen was 136, expected 135.9 (SMR = 100) when Swedish men were used as a reference population. For ischaemic heart disease (IHD) (ICD-8: 410-414) the SMR was equal to 96 (obs = 131, exp = 137.2) for sea pilots and 91 (obs = 44, exp = 48.4) for boatmen. No trend over time or geographical differences could be observed. A healthy worker effect could not explain why there was no excess mortality from IHD.

Aged

The Swedish childhood diabetes study--results from a nine year case register and a one year case-referent study indicating that type 1 (insulin-dependent) diabetes mellitus is associated with both type 2 (non-insulin-dependent) diabetes mellitus and autoimmune disorders.

From July 1, 1977 to July 1, 1986, 3,503 incident cases of Type 1 (insulin-dependent) diabetes mellitus were registered in the Swedish childhood diabetes study. Using data from this register and from a case-referent study, including all incident Type 1 diabetic children in Sweden during one year and, for each patient, two referent children matched according to age, sex and county, we have studied the associations between Type 1 diabetes and familial Type 1 and Type 2 (non-insulin-dependent) diabetes, thyroid, adrenal, allergic, rheumatic, heart and bowel disease. The mean annual incidence per 100,000 during the nine year period was 25.1 for boys and 23.5 for girls. In 8.5% of the patients, one parent had Type 1 diabetes, 73% of whom were fathers. Fifty-six of the patients (1.7%) had a parent with Type 2 diabetes. The prevalence of parental Type 1 diabetes tended to be higher in patients with younger age at onset; whereas, the opposite was found for patients with parental Type 2 diabetes. In the case-referent study, the age-adjusted odds ratio for Type 1 diabetes when a first and/or second degree relative had Type 1 diabetes was 5.5 (95% confidence limits 4.0-7.7), and in accordance with the findings of the case register, the odds ratio tended to be highest in patients with the youngest age at onset. Season at onset of the patients was not associated with parental Type 1 diabetes. The odds ratio for Type 1 diabetes was significantly increased 3.3 (95% confidence limits: 2.3-4.6) when Type 2 diabetes was reported in relatives (three generations).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent

The Swedish childhood diabetes study--social and perinatal determinants for diabetes in childhood.

Using the Swedish childhood diabetes register, a nationwide, case-referent study was performed from September 1, 1985 to August 31, 1986. Based on the information from a mailed questionnaire sent to all incident diabetic children and for each diabetic child - two referent children matched according to age, sex, and county, we have analysed perinatal events and aspects of the social environment as possible risk factors for Type 1 (insulin-dependent) diabetes in childhood. A significantly larger proportion of the mothers of the diabetic children were older than 40 years compared to those of the referent children (33% and 24%, p = 0.01 respectively). A smaller percentage of mothers of the diabetic children had a high educational level compared to mothers of referent children (10% and 15%, p = 0.03 respectively) and 39% of the fathers of the diabetic children were manual workers compared to 31% of the fathers of referent children (p = 0.03). Perinatal events did not differ between diabetic and referent children. In children 0-6 years, the duration of breast-feeding was significantly shorter in diabetic children than among referent children (median duration for diabetic children 5 months compared to 6 months for referent children p = 0.03). When considering the presence of Type 1 diabetes among relatives, maternal age over 40 years, low educational level of the mother, and the father being a manual worker as risk factors, the presence of 1 to 4 of any of these risk factors increased the relative risk for Type 1 diabetes cumulatively from 1.2-7.5.(ABSTRACT TRUNCATED AT 250 WORDS)

Child

Diet and cancer mortality in the counties of Sweden.

The association between standardized cancer mortality rate ratios from 1969-1978 and dietary practices was examined in an ecologic study of the 24 counties of Sweden by means of several independent data sources. The study supports the hypothesis that a high intake of cereal fiber protects against colorectal cancer (r = -0.75 for males and r = -0.67 for females). This study found no association between fat intake and colorectal cancer. However, a negative correlation between milk consumption and this type of cancer was found. A suggested hypothesis is that calcium protects against colorectal cancer, since milk is the major source for calcium intake in Sweden. This could indicate that, for societies with a high fat intake, preventive measures which increase the intake of fiber and milk or calcium might have a greater impact on mortality from cancer of the colon and rectum than would a moderate decrease in the intake of fat. There are no indications in this study that fat intake promotes breast cancer.

Adolescent

Lung function abnormalities in patients with primary biliary cirrhosis.

Twenty-five patients with primary biliary cirrhosis (PBC) in different stages were investigated with respect to pulmonary function abnormalities. The results were compared with a reference sample of 17 sex- and age-matched healthy subjects. A high prevalence of lung function impairment was found in the PBC patients (14/25 [56%]). Bronchial asthma was present in three patients, and severe lung emphysema in one. These four patients had an abnormal lung function, mainly of obstructive type. There was a statistically significant difference between the remaining 21 PBC patients without chronic obstructive lung disease and the reference subjects with respect to diffusion capacity. Almost all abnormal lung function data were found in the symptomatic PBC patients (i.e. symptoms of pruritus, xanthoma, xanthelasmata, jaundice, hyperpigmentation, hepatosplenomegaly), 13 out of 18 (72%), whereas only one out of seven asymptomatic patients was affected. Nine patients (36%) had reduced diffusion capacity compared with none of the reference subjects. The lung function abnormalities in PBC patients are similar to those found in sarcoidosis, another granulomatous disease.

Adult