Biomedical subjects

H Eriksson

Publications and source records attributed to H Eriksson.

At least 163 records · Page 9Linked to original sources

PubMed1987

Diabetes mellitus in Swedish middle-aged men. The study of men born in 1913 and 1923.

As part of a study of the epidemiology of diabetes mellitus in middle-aged Swedish men, the present paper reports the prevalence and incidence of diabetes and the prevalence of impaired glucose tolerance. Two cohorts of 50-year-old men, representative of the corresponding male population of Gothenburg, Sweden, were examined in 1963 and 1973, respectively, and then followed until 1980. In the cohort of men born in 1913 (n = 855) the diabetes prevalence (WHO criteria), based on a questionnaire and fasting blood glucose, increased from 1.5% at age 50 to 7.6% at age 67. In the cohort of men born in 1923 (n = 226) the prevalence was 3.7% at age 50 and 4.0% at age 57. The overall prevalence of diabetes and impaired glucose tolerance was 25% among men born in 1913 (age 67) and 18% among men born in 1923 (age 57). The cumulative risk of developing diabetes from age 50 to 67 was 7.8%. Variables associated with impaired glucose tolerance and newly found diabetes, when degree of obesity was considered, were systolic blood pressure and triglycerides, well known risk factors for both coronary heart disease and diabetes. Uric acid, fasting insulin and glutamic puruvic transaminase, recently discussed as possible risk factors, were also associated with impaired glucose tolerance and newly found diabetes. Thus, both impaired glucose tolerance and newly found diabetes were associated with a clustering of risk factors, not only for diabetes but also for coronary heart disease.

Blood Glucose↗

PubMed1987

Effect of long-term administration of manganese on biogenic amine levels in discrete striatal regions of rat brain.

The effect of long-term manganese exposure of rats on biogenic amine levels in striatal brain regions is described. Four groups of male Sprague-Dawley rats received manganese as MnCl2 continuously in the drinking water for 60, 100, 165 and 265 days, respectively. Discrete regions within the caudate-putamen were punched out. Dopamine, 3,4-dihydroxyphenylacetic acid, homovanillic acid, serotonin and 5-hydroxyindoleacetic acid were determined by high performance liquid chromatography with electrochemical detection. Rats exposed for 60 and 165 days showed significantly increased levels of dopamine and 3,4-dihydroxyphenylacetic acid in discrete regions of the dorsal caudate-putamen. The affected regions were possibly not identical in the two age groups but they were adjacently situated. These alterations were not found in rats exposed for 100 or 265 days.

Animals↗

PubMed1987

Effects of manganese oxide on monkeys as revealed by a combined neurochemical, histological and neurophysiological evaluation.

Four monkeys were exposed to a total of 8 g each of manganese as oxide by repetitive subcutaneous injections during 5 months, after which they were left for 1 week to 6 months before they were sacrificed. All animals developed hyperactive behaviour after about 2 months. About 5 months after the start of the exposure the animals became hypoactive with an unsteady gait, and subsequently an action tremor appeared in some of the animals. The animals lost power in both upper and lower limbs and the movements of the hands and feet were very clumsy. The serum content of manganese rose 10-40 times during the exposure time and the content in brain was generally increased more than 10 times, with the highest content found in globus pallidus and putamen. The observed neurochemical effects were also largest in globus pallidus and putamen. In these regions there was a considerable depletion of dopamine and 3,4-dihydroxyphenylacetic acid, while the homovanillic acid content remained almost unchanged. A severe neuronal cell loss was observed in globus pallidus but not in other regions. This is in accordance with results from the most recent neuropathological study of a human suffering from chronic manganese poisoning [Yamada et al. (1986) Acta Neuropathol 70: 273-278] where globus pallidus was devoid of neuronal cells while the content of pigmented cells in substantia nigra was normal. Our data suggest a reduction in number of dopaminergic nerve terminals, as the activity of the dopamine synthesizing enzyme DOPA-decarboxylase was also lowered.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1987

Cardiac and pulmonary causes of dyspnoea--validation of a scoring test for clinical-epidemiological use: the Study of Men Born in 1913.

Dyspnoea is one of the earliest symptoms in several conditions, such as heart disease and airway obstruction. However, the early phases of these two conditions are hard to distinguish in a reproducible way. In a population study of the natural history and epidemiology of congestive heart failure a scoring test to differentiate the two conditions was developed. In this report the test is presented and evaluated against various clinical and laboratory measures in 644 men sampled from the general population. The test provides a 'cardiac score' and a 'pulmonary score', both based on history and findings at the physical examination. Men who had pulmonary scores (indicating a pulmonary cause of the dyspnoea) had significantly lower values of spirometry variables but no significant pulmonary congestion at X-ray compared to a reference group (no dyspnoea, no pulmonary scores). Men with cardiac scores had significantly larger hearts and more congestion but no significant change of variables measuring airways obstruction compared to the reference group (no dyspnoea, no cardiac scores). Even though there was a moderate overlap of impaired cardiac and pulmonary function in the dyspnoea group, perhaps due to smoking being a common causal agent, the test appears to differentiate the causes of dyspnoea in a manner similar to clinical evaluation but, in contrast to the latter, in a defined and therefore reproducible way.

Aged↗

PubMed1987

Dyspnoea in a cross-sectional and a longitudinal study of middle-aged men: the Study of Men Born in 1913 and 1923.

In a longitudinal population study, 855 men, born in 1913 and initially examined when 50 years old, were followed for 17 years with measurements of dyspnoea and other variables performed at ages 50, 54, and 67 years. In addition a sample of 226 men born in 1923 was followed from 50 to 57 years of age. At the latest examination, four different methods for measuring dyspnoea were used, one based on questionnaire, one on interview, and two on visual analogue scales. The estimates from these methods were highly intercorrelated, and correlated with measures of cardiopulmonary function as well. The prevalence of dyspnoea grade 2 (shortness of breath when walking with someone of the same age on the level) or more, not counting the mildest form of dyspnoea in these populations, was 2.8%, 3.0%, 5.2% and 10.3% at 50, 54, 57 and 67 years of age, respectively. Dyspnoea grade 1 (shortness of breath when walking quickly on the level or uphill) was less well related to age. A scoring system to differentiate various possible causes of dyspnoea was applied. About one third of the dyspnoeic men had signs and symptoms of cardiac disease, one quarter had pulmonary disease, and a quarter had a combination of both causes. The remaining 20% had no signs or symptoms indicating cardiopulmonary disease but in the majority of the cases other plausible causes were found.

Aged↗

PubMed1987

The mortality in an age cohort followed from birth to age 70.

The Study of Men Born in 1913 is a prospective population study of cardiovascular diseases in Gothenburg, Sweden, that started in 1963. To describe survival curves and mortality pattern, all boy-children born alive in 1913 in the city of Gothenburg, were identified. This birth cohort was followed from birth to age 70 for residence, vital status and cause of death. At the age of 50 years, 25% of the birth cohort were dead and at age 70, 43% had died. The high infant mortality and the great impact of infectious diseases in the beginning of this century is illustrated. The death rate for the cohort was almost identical to national figures for men in the same age group. Men who migrated from Gothenburg had a death rate very similar to those who stayed. It can therefore be concluded that the men in the Study of Men Born in 1913 is a representative sample not only of men in Gothenburg but also of men in Sweden as far as mortality is concerned. Special attention was paid to death from otitis media complications, congestive heart failure, and diabetes. Few persons died from these diseases before age 50 when the prospective study started and therefore did not influence the study of the natural history for these conditions to any great extent. Otitis media infections might be studied retrospectively from this age.

Aged↗

PubMed1986

The acute GH action in rat adipocytes is associated with enhanced phosphorylation of a 46 kDa plasma membrane protein enriched by GH-Sepharose.

The acute anti-lipolytic effect of human growth hormone (hGH) in maximally noradrenaline-stimulated intact rat adipocytes was selectively associated with increased phosphorylation of a 46 kDa plasma membrane protein which was highly enriched by hGH-Sepharose chromatography. The same protein was also phosphorylated by an endogenous protein kinase in isolated plasma membranes, although then no hGH effect could be demonstrated. About 14% of the phosphate incorporated into the protein in isolated plasma membranes was found in tyrosine residues and the remainder in serine and threonine. The possible relation of the 46 kDa protein with the hGH plasma membrane receptor is discussed.

Adipose Tissue↗

PubMed1986

Fasting blood glucose and risk of coronary heart disease, stroke, and all-cause mortality: a 17-year follow-up study of men born in 1913.

This report concerns the relationship between baseline levels of fasting blood glucose (FBG) in non-diabetics and the subsequent 17-year incidence of coronary heart disease (CHD), stroke and all-cause mortality. In 1963, 973 men aged 50 years were recruited from a general Swedish urban population for a prospective study of risk factors for CHD. Eight hundred and fifty-five (88%) men agreed to participate and have been observed for 17 years. The 832 men who had no history of myocardial infarction, stroke, diabetes mellitus or who had a fasting blood glucose below 7.0 mmol/l at baseline were selected for this analysis. CHD occurred in 106 men, 35 developed a stroke and 137 died during follow-up. When quintiles and deciles of the FBG distribution were considered, no trend of 17-year incidence of CHD, stroke or death was apparent. However, for men with an FBG above the 95th percentile (greater than 5.7 mmol/l) a non-significant trend towards increasing risk was indicated.

Aged↗

PubMed1986

Pitfalls in the assay of cyclic AMP-dependent protein kinase activity in microsacs from Torpedo marmorata.

Endogenous phosphorylation of the nicotinic acetylcholine receptor (nAChR) in microsacs from Torpedo marmorata was found to be affected by several reagents commonly used in the preparation of cyclic AMP (cAMP)-dependent protein kinases and in its activity determination. The presence of a Na+,K+-ATPase inhibitor is essential to avoid a rapid depletion of ATP, even when a membrane fraction highly enriched in the nAChR is used. The presence of the thiol reducing agent dithiothreitol was found to abolish the cAMP dependence of nAChR phosphorylation, whereas the less potent reagent 2-mercaptoethanol did not affect the assay. Concentrations in the millimolar range of the chelators EDTA and EGTA were found to inhibit nAChR phosphorylation effectively. This inhibition was not due to a withdrawal of Ca2+ by the chelators, but rather to a reversible inhibition by the Mg2+ complexes. These observations may explain some of the discrepancies found in the literature concerning endogenous and exogenous nAChR phosphorylation.

Animals↗

PubMed1986

Effects of manganese chloride on the rat developing nervous system.

Sprague-Dawley rats were exposed to sublethal doses of manganese chloride during their postnatal development period up to 44 days of age. They showed transient clinical signs of disease and a decreased homovanillic acid (HVA) content in the striatum and hypothalamus between 15 and 22 days of age. The manganese content in the brain was increased 20-40 times during this period as determined with neutron activation analyses. In spite of this no structural damage or signs of maturation disturbances in the nervous system were found. Interruption of manganese exposure reversed the changes in HVA content.

Animals↗

PubMed1985

A sensitive method to introduce membrane-bound proteins into recipient cells based on affinity enrichment of lipid vesicles to the recipient cell prior to fusion.

A sensitive analytical procedure for studying membrane-bound structures has been developed. Membrane glycoproteins inserted into liposomes were transferred to recipient cells by use of a lectin, concanavalin A, bound to the cells as a bridge to generate proximity between the recipient cell and the glycoprotein-containing liposome, prior to exposure to the fusing agent, poly(ethylene glycol). Partially purified histocompatibility antigen from rats was introduced into the membrane of human lymphocytes. After treating the cells with poly(ethylene glycol) under fusion conditions, some of the antigen present in the preparation could not be eluted with alpha-methyl mannoside and EDTA, indicating that incorporation in the cell membrane had taken place. This antigen remained exposed on the lymphocyte surface for approximately 1 h as demonstrated by sensitivity of the lymphocytes to the lytic effect of an antiserum to the histocompatibility antigen in the presence of complement. Some of the lectin molecules seemed to be internalized in the cells but no induction of cell mitosis was observed. The described method gives an opportunity to work with small amounts of membrane proteins inserted into liposomes, introducing them into recipient cells for analysis of their biological activities.

Animals↗

PubMed1985

Oestradiol and progesterone receptors in the pig oviduct during the oestrous cycle.

The concentrations of the tissue receptors for oestradiol (E) and progesterone (P) in the porcine oviduct at different stages on the oestrous cycle have been investigated by in vitro binding and exchange methods. Both hormones bound to specific cytoplasmic (Rc) and nuclear (Rn) receptor proteins with high affinity. The concentrations of ERc and ERn were two-fold higher in the ampulla as compared to the isthmus. The amount of ERc in the isthmic portion of the oviduct did not vary throughout the oestrous cycle. However, the ampullar ERc concentrations increased during prooestrus, showed a maximum at standing oestrus, thereafter decreasing. Significant variations in the amount of oviductal ERn were observed. Despite the differences in ERn amounts between segments, the concentration of ERn increased significantly during late prooestrus, attaining a three-fold elevation and remaining elevated during the period of standing oestrous and early luteal phase (days 3-4), thereafter returning to basal levels. No significant variations in the amount of isthmic PRc were found throughout the period studied. The ampulla, however, showed a significant increase in PRc concentrations during standing oestrus, thereafter decreasing. The concentrations of PRn in isthmus and ampulla were of about the same magnitude and varied significantly during the oestrous cycle, increasing in concentration from standing oestrous onwards. The temporal relationships between the variations in levels of oestradiol and progesterone receptors in oviductal tissues and those of the circulating plasma levels were established. The data obtained in this study suggest a relationship between the changes in the levels of oestradiol and progesterone oviductal binding during the first days of the oestrous cycle, and the gamete and embryo transport throughout the oviduct in the porcine species.

Animals↗

PubMed1985

Medical chemistry: evaluation of active and problem-oriented teaching methods.

In the preclinical phase of basic medical education at the Karolinska Institute in Stockholm, Sweden, chemistry extends over 16 weeks and changes were made to the teaching methods during 7 of those weeks--one in organic chemistry and 6 in intermediary metabolism. The number of lectures was reduced and problem-oriented group tasks wee introduced instead which required a higher level of student responsibility for individual learning. Teaching and group tasks were designed to give the students a better understanding of the biochemical processes in their entirety as well as the way these are controlled in the human body. From this base the students will be enabled to discuss and understand physiological, pathological and medical phenomena. Experience and results show that student performance in examinations improved significantly, that students acquired a better understanding and a more comprehensive grasp of the subject, and a noticeably more positive interest in medical chemistry. They remember approximately 60% more a few years after completing the course than do students who have been instructed in a more traditional manner, and although the load of the teachers has increased by some 20% in respect of scheduled time, the instructors have gained in improved student contact and a wider knowledge of their subjects. The results have remained the same for each course since the change was introduced in 1977. Due to new admission criteria, more students now have less knowledge of mathematics and chemistry, and more students have social circumstances that make independent studies more attractive (family obligations and financial obligations).(ABSTRACT TRUNCATED AT 250 WORDS)

Biochemistry↗

PubMed1985

Oxotremorine acts as a partial nicotinic agonist on cultured chick myotubes.

Oxotremorine, a compound widely used as a muscarinic agonist, was found to inhibit binding of 125I-alpha-bungarotoxin to chick myotube nicotinic acetylcholine receptors, IC50 = 79 +/- 5 microM. Oxotremorine also induced a d-tubocurarine sensitive influx of 86Rb in the myotubes (EC50 = 50 +/- 15 microM). Comparative ion-flux studies with carbachol suggested a partial agonist mode of action of oxotremorine.

Animals↗

PubMed1985

ATP-induced cation influx in myotubes is additive to cholinergic agonist action.

Using biochemical methods, ATP was shown to induce an inward flux of 86Rb into cultured chick myotubes. A biphasic dose-response curve was observed, the first part of which was saturable and had an EC50 value of approximately 10 microM. beta, gamma-imido ATP inhibited the ATP-induced uptake. ADP, AMP and adenosine were less potent than ATP in producing influx. ATP-induced influx of 86Rb was found to be additive to carbachol-induced influx and, in contrast to the latter, not blocked by the nicotinic acetylcholine receptor antagonist alpha-bungarotoxin. The results suggest the presence of an ATP recognition-site on myotubes, triggering ion-permeation.

Adenosine Triphosphate↗

PubMed1985

The influence of body fat distribution on the incidence of diabetes mellitus. 13.5 years of follow-up of the participants in the study of men born in 1913.

In a prospective study of risk factors for ischemic heart disease, 792 54-yr-old men selected by year of birth (1913) and residence in Göteborg, Sweden, agreed to attend for questioning and a number of anthropometric and other measurements in 1967. Thirteen and one-half years later, these baseline findings were reviewed in relation to the number of men who had subsequently developed diabetes mellitus. This analysis focused on the importance of abdominal adipose tissue distribution, measured as the waist-to-hip circumference ratio, as a predictor for development of diabetes. Even when the confounding effect of body mass index, as a measure of the total body fat mass, was accounted for, the waist-to-hip ratio was positively and significantly associated with the risk for diabetes. These results from a prospective study strongly support previous cross-sectional findings indicating that not only the degree of obesity but also the localization of fat is a risk factor for diabetes.

Abdomen↗

PubMed1985

Body temperature in general population samples. The study of men born in 1913 and 1923.

Oral body temperature was measured in 816 men, 57 and 67 years old, sampled from the general population of Göteborg, Sweden, and 22 physically highly active men, sampled on clinical grounds. The measurements were taken in the morning for 14 months. After adding 0.3 degrees C to the readings to make them comparable with rectal readings, the mean body temperature was 36.8 +/- 0.4 degrees C. There was a seasonal variation with a peak during the winter and a trough during the summer. Body temperature was inversely correlated with height and positively correlated with weight and body fat but not with lean body mass. High physical activity and sensitivity to heat were associated with a higher than average body temperature. Sensitivity to cold was associated with a lower than average body temperature. Smoking prior to the measurements did not appear to affect body temperature.

Age Factors↗

PubMed1984

Lectin-mediated binding of liposome-inserted membrane proteins to red blood cells. A method to detect binding of antibodies to purified rat histocompatibility antigen or binding of insulin to the insulin receptor.

Partially purified membrane proteins such as the rat RT-1 histocompatibility antigen or the insulin receptor of porcine liver were inserted into liposomes. These liposomes then bound efficiently to Con A-coated red blood cells. After attachment of the liposomes to the cells, cell-liposome conjugates could be separated from free liposomes by centrifugation. Binding of FITC-labeled specific antibodies or insulin to membrane proteins inserted into the liposomes could then be analyzed with a cell flow cytofluorometer. The amount of RT-1 antigen that became associated with the cells depended on the composition and concentration of phospholipids during liposome formation. No association of RT-1 antigen to the cells was obtained in the presence of 50 mM alpha-methyl mannoside. The technique allows detection of micrograms amounts of the histocompatibility antigen associated with the red blood cells. It was possible to detect binding of insulin to cells to which approximately 9 ng (3 X 10(-14) mol) insulin receptor/10(6) cells had been attached. This amount of membrane protein was close to the detection limit of the method.

Animals↗