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Biomedical subjects

L G Heding

Publications and source records attributed to L G Heding.

At least 55 records · Page 3Linked to original sources
PubMed1980

Glomerular structural changes in rabbits on treatment with bovine and porcine insulin. A morphometric analysis.

Weak nonspecific immunological stimuli can irritate the glomerular mesangium as observed following administration of insulin preparations of varying degrees of purity. In the present study further substances were investigated with regard to this effect. We wished to examine which substances obtained during purification of insulin are mainly responsible for the antigenicity, and whether porcine and bovine MC insulin have the same antigenic properties. Rabbits were treated for up to 90 days with bovine MC insulin, bovine proinsulin, bovine a + b-component, porcine a-component and porcine b-component. The kidneys were analysed morphometrically and antibody titers to bovine insulin, a-component, porcine PP and proinsulin were determined in the various test groups. It was found that bovine MC insulin and porcine MC insulin possess the same immunological activity, i.e. no antibody formation to either of the two insulins was demonstrable. Similarly, there were no differences in the morphometric findings; slight transient mesangial changes were demonstrable after both insulins. However a-component and b-component showed a pronounced immunogenic potency with antibody formation. Marked and partly persisting mesangial alterations were demonstrable, with the antigenicity of the a-component being particularly marked. The implication of the study is that a "pure" or optimally purified insulin should be used in the therapy of diabetes mellitus.

Animals↗
PubMed1980

Metabolic responses to hypoglycemia in juvenile diabetics.

Glucagon and metabolic responses to insulin-induced hypoglycemia were studied in seven juvenile diabetics, age 31 +/- 2 years (mean and S.E.M.), duration of diabetes 17 +/- 3 years, with diabetic autonomic neuropathy (decreased beat-to-beat variation in heart rate during hyperventilation and/or orthostatic hypotension) and in seven control patients of similar age and duration of diabetes with out neuropathy. Before the hypoglycaemic episode, normoglycemia had been maintained for at least 10 hours. Following hypoglycemia, a slight but significant and similar increase in plasma glucagon was found in both patient groups. Metabolic responses to hypoglycemia were also similar in the two patient groups. In conclusion, diabetic autonomic neuropathy has no effect on glucagon and metabolic responses to hypoglycemia in juvenile, insulin-treated diabetics.

Adult↗
PubMed1980

Pancreatic B-cell function and abnormal urinary peptides in a boy with lipoatrophic diabetes and stenosis of the aqueduct of Sylvius.

A boy with the classical clinical manifestations of acquired lipoatrophic diabetes has been studied for 5 years from the onset of diabetes at age 13. At the age of 15 a ventriculo-cisternal shunt operation was performed because of stenosis of the aqueduct of Sylvius, followed by a dramatic improvement in his diabetic state with a decrease of the 24 hr insulin requirement from 130 to 32 units. After 12 months there was a relapse with increased insulin requirement up to the preoperative level. Pimozide treatment was given for 7 months with no effect on the metabolic derangements. Extremely high basal levels of serum C-peptide and pro-insulin were found throughout the period of observation. A further increase occurred after i.v. arginine infusion tests, indicating hyperfunctioning B-cells. Repeated screenings of peptides in the urine by sephadex chromatography revealed pathological patterns similar to those observed in patients with other hypothalamic disorders, but different from that found in the urine of patients with congenital generalized lipodystrophy. Injection into mice of peptides extracted from the preoperative urine produced an acute hyperglycemia. The mechanisms behind this hypothalamic syndrome are unknown, but it is postulated that the abnormal urinary polypeptides originate from disorganized hypothalamic centres and that these peptides may be responsible for the disturbed carbohydrate and lipid metabolism.

Adolescent↗
PubMed1980

B-cell response to exercise in diabetic and non-diabetic children.

20 non-diabetic and 11 insulin dependent diabetic (IDD) children underwent short time (20 min) bicycle ergometer exercise followed by a 10 min rest period. Glucose, IRI, C-peptide and proinsulin were determined prior to and at the end of the exercise, and again after 10 min rest. While no significant change in mean glucose was observed during exercise in the non-diabetics, significant decreases were observed in IRI, C-peptide and proinsulin. After 10 min rest glucose as well as the three B-cell secretory products increased significantly. The change in glucose was significantly (p less than 0.001) correlated to the change in IRI. In the resting period IRI rose more than C-peptide in some subjects. IRI even rose without simultaneous rise in C-peptide indicating a release of tissue bound IRI. The group of IDD children did not show any significant changes in glucose and total IRI, while the endogenous insulin, as measured by C-peptide, did show a fall during exercise. The same was found for proinsulin. The lack of increased endogenous secretion during the rest period was most likely due to suppression of B-cell due to hyperinsulinism and lack of increased glucose concentrations during the rest period.

Adolescent↗
PubMed1979

Development of ketonemia in fasting patients with hyperthyroidism.

Concentrations of ketone bodies, free fatty acids, glycerol, lactate, glucose, insulin, glucagon and cortisol were determined 6-hourly during 36 hours of fasting in 4 hyperthyroid patients and in 4 euthyroid controls. The concentrations of ketone bodies were elevated in hyperthyroid patients from the beginning and increased during fasting more rapidly and to higher values as compared to the controls. After 6 hours of fasting the blood ketone concentrations were 1.1--1.8 mM in hyperthyroid patients and 0.3--0.6 mM in the controls. After 36 hours the concentrations had increased to about 3.5 mM and 1.4 mM in hyperthyroid and control subjects, respectively. The concentrations of free fatty acids were identical in the groups compared postprandially, but increased significantly more in the hyperthyroid patients than in the controls during fasting. The glycerol concentration was higher in the hyperthyroid group throughout the observation period. The concentrations of insulin were slightly higher in the hyperthyroid group than in the control, whereas the concentrations of the "ketogenic" hormones, glucagon and cortisol were identical in the compared groups. It is concluded that hyperthyroidism leads to an increased tendency to ketosis, that is partly explained by increased concentrations of free fatty acids and that might also involve a direct action of long term thyroid hormone excess on enzyme activities (e.g. carnitine acyltransferase in liver).

Adult↗
PubMed1979

Metabolic studies in acute asthma before and after treatment.

We studied the metabolism and hormone profile of 9 patients with moderately severe acute asthma before treatment, and again 10 min after intravenous aminophylline (250 mg) or the selective beta-adrenergic stimulant hexoprenaline (5 microgram) intravenously. Compared with basal values in normal subjects the untreated asthmatics had statistically significant raised mean plasma pancreatic glucagon, free fatty acid (FFA) and glucose levels in the plasma and a significantly depressed mean plasma potassium level. Insulin, growth hormone, cortisol, thyrotropin and ketone body levels were normal. The only significant changes after therapy were a further fall in plasma potassium in the hexoprenaline-treated patients and a rise in the mean lactate concentration of the group as a whole. The clinical implications of these findings are briefly considered.

Acute Disease↗
PubMed1978

Hormonal profile, blood sugar control and HLA patterns in long-term insulin dependent diabetes with and without vascular disease.

Nineteen insulin dependent diabetics with onset at 30 years of age or less and duration of diabetes of greater than 25 years were divided into two groups on the basis of the presence or absence of clinically evident vascular disease. The patients without vascular disease were characterised by a later mean age of onset, lower fasting growth hormone concentration, and a lower frequency of the unusual HLA pattern B8 without A1 compared to the diabetics with vascular complications. The level of blood glucose control assessed over the last 15 years, insulin antibody titres, plasma glucagon levels and plasma cholesterol did not differ between the two groups. Residual beta cell activity was found in only one of the 19 patients. Although this study does not exclude an effect of the degree of blood glucose control or persistence of beta cell function in the early stages of diabetes on the subsequent development of vascular disease, it suggests that genetic factors, age of onset and plasma growth hormone levels may be more important.

Adult↗
PubMed1978

Characterization of seven C-peptide antisera.

The plasma C-peptide immunoreactivity (CPR) in 10 normal subjects varied considerably when measured with different antisera in parallel assays. The CPR level correlated with the blank "CPR" value measured in plasma devoid of C-peptide and to a lesser degree with the sensitivity of the standard curves obtained with the individual antisera. Storage of plasma samples at different temperatures and for different lengths of time before the analyses were carried out resulted in further variation in the CPR results. This was caused by a time- and temperature-dependent fall in CPR, which was more pronounced with some antisera than with others. This sensitivity to storage of plasma did not correlate with the antigenic characteristics of the antisera as determined by their reactivity with 11 specific fragments of the C-peptide molecule. The contribution of human proinsulin to the CPR concentration relative in normal subjects was considered to be negligible even though the relative immunoreactivity of human proinsulin and C-peptide ranged from 11 to 143 per cent among these antisera. These results suggest that differences in C-peptide antisera are a major reason for the variation in the concentration of circulating CPR as measured in different C-peptide immunoassays.

Animals↗
PubMed1978

beta-cell function in children with diabetes.

Although it is generally believed that insulin secretion is minimal or absent in juvenile-onset diabetes, we have found appreciable levels of C-peptide at the time of onset in 12 patients, 4 to 16 years old (9.3 +/- 4.2). Ten of them had ketonuria but none severe ketoacidosis. All entered a remission period. Most of the patients had near normal C-peptide levels during the remission, and their beta cells had the capacity to respond to a breakfast stimulation with increased insulin secretion. C-peptide and proinsulin were also determined in 98 juvenile diabetics with age at onset of 1 to 16 years (6.8 +/- 3.9) and a duration of diabetes between two and 17 years (6.7 +/- 3.4). Many were found to have persisting beta-cell function, which seems to be of importance for ensuring stability in metabolic control. Although little is known about factors that may slow or reverse the process leading to beta-cell failure, our results suggest that early detection and intensive treatment of diabetes before severe metabolic disturbances have occurred may help preserve beta-cell function.

Adolescent↗
PubMed1977

HLA-types, C-peptide and insulin antibodies in juvenile diabetes.

HLA-types were determined in 102 juvenile diabetics. HLA-B8 was found in 39 patients (RR 2.64; p less than 0.01) and HLA-BW15 in 32 patients (RR 1.33; n.s.). HLA-B7 was found in 14 patients (RR 0.40; p less than 0;05). There were no correlations between HLA-B8 or BW15 and family history of diabetes, occurrence of infection before onset of diabetes, ketonuria at onset or the age at onset of diabetes. Serum C-peptide, insulin binding capacity of IgG and total serum insulin, IRI, were determined in 94 patients who had had diabetes for more than two years and who were beyond the remission period. Measurable amounts of C-peptide were found in 33 patients (34.7%). There was no evidence of a relationship between any particular HLA-antigen and the B-cell function except for an increased incidence of do a decreased incidence of detectable C-peptide in patients with the combination HLA-B8, W15. Only four patients (4.3%) were lacking insulin antibodies; HLA-BW15 positive patients had higher levels of insulin antibodies than other groups, while HLA-B7 positive patients had lower levels; The results suggest that HLA-B7 and HLA-B18 might be associated with a different and perhaps milder form of juvenile diabetes.

Adolescent↗