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Biomedical subjects

C Kühl

Publications and source records attributed to C Kühl.

121 records · Page 7Linked to original sources
PubMed1975

Dipping procedure for blood glucose determination with Dextrostix and the Eyetone reflectance meter. Assessment of a practical technique.

A dipping procedure for blood glucose determination with the Dextrastix-Eyetone system has been evaluated. The procedure involves the immersion of the Dextrostix reagent area for 1 min in a tube of whole blood followed by wash, blotting and reading as in the regular procedure. Sixty-five blood samples, covering a wide glucose concentration range, were estimated for their glucose content in random order both by the dipping procedure and a conventional Dextrostix-Eyetone procedure. An almost perfect agreement between the two methods was found, the coefficient of correlation being 0.99 and the regression line very close to the ideal line. The presence of a Dextrostix reagent area in the blood was found to bring about glycolysis. Except at high blood glucose levels, this glycolysis, however, was insignificant if the strip was correctly removed after 1 min. The dipping procedure overcomes the main technical problem of conventional procedures: the inconsistency of the drop application on the reagent area. As it is easy to perform and a reliable alternative to conventional procedures, it is recommendable in all cases where blood samples are available.

Blood Glucose↗
PubMed1975

Human placental lactogen concentration during physiological fluctuations of serum glucose in normal pregnant and gestational diabetic women.

Oral glucose tolerance tests (OGTT) were carried out in 9 normal pregnant women and 11 non-obese gestational diabetics in late pregnancy. All samples were analysed for the content of glucose, insulin and placental lactogen hormone (HPL). Furthermore, spontaneous changes in the serum HPL concentration during a 3 h period were studied in 6 normal women in the 2nd half of pregnancy. During OGTT only small and insignificant changes in the level of HPL were observed in both the normal subjects and the gestational diabetics. Furthermore, the mean HPL concentration curves of the normal subjects and the gestational diabetics were superimposed although the mean glucose concentration curves were significantly different. The study of spontaneous changes in HPL revealed only small and insignificant fluctuations in the serum HPL level, and the mean concentration curve resembled those obtained from the OGTT-study. It is concluded that neither the absolute serum glucose level, nor physiological fluctuations in the serum glucose concentration seemed to influence the serum concentration of HPL in this type of patients.

Adult↗
PubMed1975

Glucose metabolism during and after pregnancy in normal and gestational diabetic women. 1. Influence of normal pregnancy on serum glucose and insulin concentration during basal fasting conditions and after a challenge with glucose.

Glucose and insulin concentrations during basal fasting conditions and after an oral challenge with glucose have been studied during early, mid and late pregnancy and also after delivery in a group of 9 normal women. No significant changes in the fasting serum glucose concentration was observed during pregnancy. In contrast the fasting serum insulin gradually increased. No changes in the mean glucose concentration curve were observed until the second half of pregnancy where the level of the curve was significantly elevated, but statistically calculated limits of normality derived from a special study of non-pregnant normal controls were not exceeded. The serum insulin response to glucose was significantly increased at all stages of gestation and in parallel the insulin-to-glucose index calculated for the total areas below the insulin and glucose concentration curves increased significantly. The fasting insulin-to-glucose index also increased and was found to be significantly correlated to the stage of gestation. The shape of the glucose and insulin curves was modified in the opposite direction by pregnancy: the peak value of glucose was delayed whereas that of insulin was advanced. The results indicate that in pregnancy a diminished "peripheral sensitivity" to endogenous insulin apparently develops.

Adult↗
PubMedDate not supplied

Neutral insulin solutions physically stabilized by addition of Zn2+.

Commercial neutral insulin solutions, all of which contain 2-3 zinc atoms per hexameric unit of insulin, have a relatively limited physical stability when exposed to heat and movement, as for example in insulin infusion pumps. Physical stabilization of neutral insulin solutions has been obtained by addition of two extra Zn2+ per hexamer of insulin. This addition stabilizes porcine and human neutral solutions equally well and does not affect the chemical stability of the insulin. The stabilization is probably obtained by a further strengthening of the hexameric structure of insulin, so that the formation of insoluble insulin fibrils (via the dissociation into the insulin monomer or dimer) is impeded or prevented. The addition of an extra 2 Zn2+ has been shown to be without influence on the insulin immunogenicity in rabbits or on the rate of absorption after subcutaneous injection in diabetic patients. It is concluded that neutral insulin solution can be physically stabilized by addition of extra Zn2+ without affecting other qualities of the insulin preparation including chemical stability, immunogenicity, and duration of action after injection.

Adult↗
PubMedDate not supplied

Comparison of glycaemic control in diabetic patients treated with morning or evening human ultratard insulin.

To investigate whether morning or evening injection of a long-acting insulin preparation (Ultratard HM, Novo) affects the glycaemic control in insulin-dependent diabetic (IDDM) patients, 24-hour blood glucose and plasma free insulin profiles were obtained in nine C-peptide negative IDDMs after one daily injection of insulin Ultratard HM either before breakfast (0800 h) or at 2200 h during the preceding 14 days. There was a tendency towards higher plasma free insulin levels and lower blood glucose values from 0100 h to 1300 h when Ultratard HM insulin was injected at 2200 h as compared to the morning injection. There was, however, only a significant difference between the corresponding plasma free insulin values at 1200 h, and blood glucose levels did not differ significantly at any time point investigated. The number of blood glucose values below 3 mmol/l in the study periods was 6 when insulin Ultratrad HM was injected at 2200 h as opposed to 2 when insulin was given at 0800 h, but this difference was not significant.

Adolescent↗
PubMedDate not supplied

Reproducibility of the glucagon test.

The influence of the fasting blood glucose (FBG) concentration on the beta-cell responsiveness to glucagon was studied twice in 9 insulin-dependent diabetic patients with residual beta-cell function. At a FBG of 7.7 +/- 0.3 mmol/l (mean +/- SEM) all patients displayed a preserved beta-cell function with a plasma C-peptide concentration of 0.25 +/- 0.03 nmol/l 6 min after an i.v. injection of glucagon. In contrast, at a FBG of 3.2 +/- 0.01 mmol/l 4 out of 9 patients would have been classified as not having an endogenous insulin secretion. All the patients had the lowest 6 min C-peptide concentration 0.06 +/- 0.01 nmol/l on the day with the lowest blood glucose concentration. The reproducibility of the glucagon test was assessed by comparing the results from two test days in 12 insulin-dependent, 9 non-insulin-dependent diabetic patients and 6 normal subjects. The 6 min plasma C-peptide concentration, the peak plasma C-peptide concentration, and the area under the plasma C-peptide curves were not different on the two test days in any subgroup. In all diabetic patients and normal subjects, the 6 min plasma C-peptide concentration (r = 0.93, coefficient of variation (CV) = 0.16), the peak plasma C-peptide concentration (r = 0.93, CV = 0.16) and the area under the plasma C-peptide curve (r = 0.94, CV = 0.16) were all significantly correlated. The results show that the prevailing FBG significantly affects the outcome of the glucagon test and confirm its reproducibility.

Adolescent↗
PubMedDate not supplied

Guar gum and glycemic control of pregnant insulin-dependent diabetic patients.

The effect of guar gum preparation on the glycemic control of 12 pregnant insulin-dependent diabetic patients was investigated. The study was performed on inpatients and lasted 3 wk (from week 32 of pregnancy and onward). Weeks 32 and 34 were control periods during which time the patients had their normal diet only. During week 33, the diet was supplemented with guar. The mean blood glucose level of week 33 was 14% lower than that of week 32 (P less than 0.01) but equal to that of week 34. Mean fluctuations of blood glucose during individual days of the 3 wk were similar. The M-value declined significantly from week 32 to week 33, but the M-value of week 33 was not different from that of week 34. The average 24-h glycosuria declined by 63% from week 32 to week 33 (P less than 0.05), whereas the values of weeks 33 and 34 were not significantly different. The mean daily insulin doses of weeks 32, 33, and 34 were similar. The results show that whereas admission of pregnant insulin-dependent diabetic women to a diabetes ward exerts a favorable influence on diabetes control, no further improvement is obtainable if the diet is supplemented with guar.

Adult↗
PubMedDate not supplied

Clinical experience with a new device that will simplify insulin injections.

In order to test clinically a newly developed, simple, and convenient device for giving multiple injections of short-acting insulin (Actrapid HM, Novo, Bagsvaerd, Denmark), 16 type I diabetic patients previously stabilized on intensified conventional therapy regimens participated in a randomized crossover study for a period of 6 wk. The patients used conventional syringes for injections of short-acting insulin during one period and the new device during the other. Conventional syringes were used for injections of basal insulin during both periods. Metabolic control was assessed by twice-weekly blood glucose profiles, HbA1c, and the frequency of hypoglycemic reactions; no significant differences were found during the two treatment periods. No infections at the injection sites were seen. Patients' evaluation of the new device was very positive.

Adult↗
PubMedDate not supplied

Absorption of subcutaneously infused insulin: influence of the basal rate pulse interval.

Eight insulin-dependent diabetic patients were given two constant infusions (each 1 IU/h) of 125I-labeled insulin into the abdominal subcutaneous tissue for about 12 h. Insulin was infused in pulses into one side of the abdomen in 6-min intervals (by means of an Auto-Syringe pump) and in the other side of the abdomen, insulin was infused in 1-h intervals (by means of a Medix pump). The size of the subcutaneous depots was continuously measured by counting the radioactivity at the infusion sites. After starting the infusions, the two depots were built up to steady-state levels at the same time and of the same size (approximately 3 IU) and with similar absorption rates. Thus, during basal rate insulin infusion, identical insulin absorption kinetics was achieved, irrespective of a 10-fold difference in the pulse rate.

Absorption↗
PubMedDate not supplied

Subcutaneous insulin infusion: change in basal infusion rate has no immediate effect on insulin absorption rate.

Eight insulin-dependent diabetic patients were simultaneously given subcutaneous infusions (1.12 IU/h each) of 125I-labeled Actrapid insulin in each side of the abdominal wall. After 24 h of infusion, the size of the infused insulin depots was measured by external counting for 5 h. The basal infusion rate was then doubled in one side and halved in the other for the next 4 h. Finally, 1.12 IU/h of insulin was given in both sides of the abdominal wall for an additional 3 h. The changes in the size of the depots were measured, and the absorption rates for each hour were calculated. During the first 5 h of infusion, the depot size was almost constant (approximately 5 IU) with an absorption rate that equaled the infusion rate. Doubling the infusion rate led to a significant increase in depot size, but the absorption rate remained unchanged for the first 3 h, and only thereafter was a significant increase seen. When the infusion rate was reduced to the initial 1.12 IU/h, the absorption rate remained elevated during the next 3 h. Correspondingly, when the infusion rate was decreased, the depot size also decreased, but the absorption rate remained unchanged for the first 3 h. The results show that a change in the basal insulin infusion rate does not lead to any immediate change in the insulin absorption rate. This should be considered when planning an insulin-infusion program that includes alteration(s) in the basal-rate setting.

Absorption↗