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Biomedical subjects

K Kjaer

Publications and source records attributed to K Kjaer.

At least 37 records · Page 2Linked to original sources
PubMed1992

Infertility and pregnancy outcome in an unselected group of women with insulin-dependent diabetes mellitus.

OBJECTIVES: The null hypothesis of this study is that infertility and pregnancy outcomes in women with insulin-dependent diabetes are identical to those of nondiabetic control subjects. STUDY DESIGN: A questionnaire survey comprising an unselected population of 18- to 49-year-old diabetic women and a comparable control group was performed. Reply rates were 94% (n = 245) and 88% (n = 253), respectively. RESULTS: Cumulative rates of pregnancies and involuntary infertility (17%) did not differ between the two groups. Diabetic women had significantly fewer pregnancies (1.4 vs 1.7) and fewer births per pregnancy than controls, and more diabetic women were nulliparous (48% vs 38%). Half of all diabetic pregnancies were planned. Diabetic women reported that their diabetes had a negative influence on their attitude toward having children. CONCLUSION: In insulin-dependent diabetic women the ability to conceive is normal, but diabetic women have fewer pregnancies and fewer births per pregnancy than controls.

Adolescent↗
PubMed1992

Epidemiology of menarche and menstrual disturbances in an unselected group of women with insulin-dependent diabetes mellitus compared to controls.

To describe the age at menarche and the prevalence of menstrual disturbances in an unselected group of women with insulin-dependent diabetes mellitus compared to controls, we identified all women having debut of diabetes mellitus before the age of 30 yr and living in the County of Funen, Denmark on July 1, 1987 and being between 18 and 49 yr old. The women received a structured questionnaire inquiring information concerning menstrual conditions. An age comparable group of nondiabetic women was used as controls; 245 (94%) diabetic women and 253 (88%) controls answered the questionnaire. Among women with debut of diabetes before the age of 10 yr, the age at menarche was delayed 1 yr when comparing to controls (P less than 0.0001). During the past 6 months before answering the questionnaire, 8.2% of the diabetic women and 2.8% of the controls had experienced episodes of secondary amenorrhea (P less than 0.01). Corresponding figures for oligomenorrhea were 10.6% and 4.8% (P less than 0.02), for polymenorrhea 7.3% and 5.2% (NS), and for all types of menstrual disturbances 21.6% and 10.8%, respectively (P less than 0.005). Episodes of secondary amenorrhea occurring more than 6 months before answering the questionnaire had been experienced by 10.7% of the diabetic population vs. 4.8% of the controls (P less than 0.05); corresponding figures for primary amenorrhea were 4.9% and 1.2%, respectively (P less than 0.05). We conclude that the age at menarche among women having developed insulin-dependent diabetes mellitus before the age of 10 yr was delayed by 1 yr when compared to controls. The overall prevalence of menstrual disturbances is increased in diabetic women compared to nondiabetic controls.

Adult↗
PubMed1992

Effect of simvastatin in patients with type I (insulin-dependent) diabetes mellitus and hypercholesterolemia.

In 10 hypercholesterolemic patients with Type I (insulin-dependent) diabetes, simvastatin 10-40 mg/day was compared to placebo in a randomized, double-blind, cross-over study with treatment periods of 12 weeks. Between each treatment there was a wash-out period of 4 weeks. Compared to placebo, simvastatin reduced total cholesterol by 19% (p less than 0.001) and low density lipoprotein (LDL) cholesterol by 24% (p less than 0.001). Simvastatin therapy reduced plasma triglyceride by 8% and increased high density lipoprotein (HDL) cholesterol by 8%, but neither of these alterations was significant (p greater than 0.05). Diabetic control and daily requirement of insulin were not influenced by simvastatin. In six patients, all men, there were no alterations in the concentrations of dehydroepiandrosterone-sulphate, testosterone, estradiol, prolactin, luteinizing hormone or follicle-stimulating hormone, while sex hormone-binding globulin was significantly (19% (p less than 0.05)) reduced during therapy with simvastatin. Thus, in Type I (insulin-dependent) diabetic patients, simvastatin causes significant reductions in plasma total cholesterol and LDL cholesterol which are similar in magnitude to those observed in non-diabetics. This favourable effect can be obtained without any concomitant negative influence on glucose regulation or total gonadal steroid hormone concentrations.

Adult↗
PubMed1992

Contraception in women with IDDM. An epidemiological study.

OBJECTIVE: To study whether suitable contraceptive methods to women with diabetes mellitus in fact are applied. RESEARCH DESIGN AND METHODS: A questionnaire survey on the use of contraceptives in all 18-to-49-yr-old women (n = 261) with IDDM in Funen County, Denmark, and an age-comparable control group, (n = 287) was performed. Data were collected from 1987 to 1990. Response was achieved from 94% diabetic women and 88% control subjects. RESULTS: The overall use of contraception in diabetic women (77.1%) was almost identical to that of control subjects (73.6%). Compared with control subjects, significantly fewer diabetic women were using the OCP (P < 0.005) and partner sterilization (P < 0.05), whereas more diabetic women were sterilized (P < 0.0005). Among diabetic contraceptive users, the IUD, female sterilization, condoms, and the OCP each accounted for roughly 20%. Diabetic women using the OCP were predominantly young, and most had never been pregnant; approximately 20% of them used high-dose formulations. Sterilization was frequently used by older diabetic women, and most of these women had 2 or more children; 27% of the diabetic women using an IUD were nulligravidae. Further, 18% used a method with an unsuitable high failure rate. CONCLUSIONS: Our study demonstrates that diabetic women are not sufficiently advised concerning use of contraception.

Adult↗
PubMed1991

Angiotensin-converting enzyme inhibition as a therapeutic principle in Bartter's syndrome.

The effect of captopril has been investigated in four patients with Bartter's syndrome treated for 12 weeks. Baseline biochemistry showed normal serum aldosterone (mean 347 pmol.l-1) and a mean serum renin of 217 mU-l-1, and a considerable increase in serum renin during captopril treatment. Serum aldosterone decreased gradually during the study period to about half its initial value. The patients presented with a mean serum potassium of 2.5 mmol.l-1, which rose to 3.4 mmol.l-1 on captopril. Lymphocytes showed a substantial captopril-induced increase in intracellular sodium (from 15 to 22.5 mmol.l-1 on average), but no change in the potassium content. Captopril was well-tolerated. It may be an alternative to potassium-sparing diuretics for maintaining normal serum potassium levels in patients with Bartter's syndrome.

Adult↗
PubMed1991

Phases of phosphatidyl ethanolamine monolayers studied by synchrotron x-ray scattering.

For the first time, phospholid monolayers at the air/water interface have been studied by x-ray diffraction and reflection all along the isotherm from the laterally isotropic fluid (the so-called LE phase) to the ordered phases. The model used to analyze the data, and the accuracy of the parameters deduced, were tested by comparing the results obtained with two lipids having the same head group but different chain lengths. Compression of the fluid phase leads predominantly to a change of thickness of the hydrophobic moiety, much less of its density, with the head group extension remaining constant. The main transition involves a considerable increase (approximately 10%) of the electron density in the hydrophobic region, a dehydration of the head group and a positional ordering of the aliphatic tails, albeit with low coherence lengths (approximately 10 spacings). On further compression of the film, the ordered phase undergoes a continuous transition. This is characterized by an increase in positional ordering, a discontinuous decrease in lateral compressibility, a decrease in chain tilt angle with respect to the surface normal towards zero and probably also a head group dehydration and ordering.

Liposomes↗
PubMed1987

Phospholipid monolayers between fluid and solid states.

Monolayers of the phospholipid dimyristoyl phosphatidic acid on the surface of water have been studied by a combination of the new techniques of synchrotron x-ray diffraction and fluorescence microscopy with classical surface pressure data. The pressure vs. area isotherm changes slope at the surface pressures pi c and pi s. The optical technique demonstrates that between pi c and pi s the fluid phase coexists with a denser "gel" phase. Electron diffraction data have shown that the gel phase has bond orientational order over tens of micrometers. However, the x-ray data demonstrate that positional correlations extend only over tens of angstroms. Thus, the gel phase is not crystalline. Above pi s a solid phase is formed with a positional correlation range that is eight times longer for the chemically purest films.

Glycerophospholipids↗
PubMed1985

Effect of quinine on plasma digoxin concentration and renal digoxin clearance.

In order to explore the digoxin-quinine interaction, digoxin steady state pharmacokinetics was studied before and during quinine coadministration in seven healthy subjects. Quinine (250 mg/day) increased mean plasma digoxin concentration from 0.64 +/- 0.12 to 0.80 +/- 0.18 ng/ml (p less than 0.05) within one week. Urinary digoxin recovery rose from 154.0 +/- 18.8 to 181.5 +/- 22.6 micrograms/24 h (p less than 0.01), whereas renal digoxin clearance was unaltered in the presence of quinine (181.5 +/- 24.2 vs. 174.1 +/- 26.5 ml/min). An increase in quinine dose (to 750 mg/day) caused further increments in plasma digoxin levels, whereas renal digoxin clearance remained unchanged. Quinine elevates plasma digoxin concentrations in a stepwise fashion probably due to an impairment of extrarenal digoxin clearance.

Adult↗
PubMed1983

Verapamil-induced changes in digoxin kinetics and intraerythrocytic sodium concentration.

Verapamil increases plasma digoxin concentration by about 60% to 80%. To explore the clinical consequences of this interaction, we evaluated single-dose digoxin kinetics along with repeated measurements of intraerythrocytic sodium concentration in eight healthy subjects before and during verapamil coadministration. Verapamil reduced mean total body clearance of digoxin from 4.68 +/- 0.41 to 3.29 +/- 0.26 ml/min/kg and prolonged digoxin biologic t1/2 from 33.5 +/- 2.4 to 41.4 +/- 2.3 hr. These kinetic changes were associated with a greater elevation of intraerythrocytic sodium concentration than controls. Verapamil had no effect on intraerythrocytic sodium content. In vitro experiments revealed no influence of verapamil on the number of glycoside receptors on human lymphocytes. Since intracellular sodium concentration has proved to correlate closely with clinical signs of digoxin toxicity, our indicate that verapamil is likely to increase the risk of digoxin-induced arrhythmias.

Adult↗
PubMed1983

Effects of physical activity and immobilization on plasma digoxin concentration and renal digoxin clearance.

Plasma digoxin concentration and renal digoxin clearance were determined during 2 hr of normal physical activity and during 2 hr of complete immobilization in eight healthy subjects on steady-state digoxin dosing. Mean plasma digoxin concentration rose from 0.64 +/- 0.13 ng/ml during physical activity to 1.04 +/- 0.19 ng/ml (63%) after 2 hr of rest. Resumption of physical activity resulted in gradual decline of plasma digoxin, and subsequent strenuous exercise reduced the value to preimmobilization level. Mean renal digoxin clearance was reduced from 168.4 +/- 18.7 ml/min during physical activity to 137.2 +/- 32.7 ml/min during rest whereas creatinine clearance was unchanged. The rise in plasma digoxin during rest is presumed to be due to changes in the binding of the drug to tissues such as skeletal muscles. Our findings indicate that attention should be given to the state of physical activity when kinetic studies are performed or when digoxin therapy is monitored by means of plasma digoxin analysis.

Adult↗
PubMed1983

The diagnostic value of determination of intraerythrocytic sodium and potassium concentrations versus plasma digoxin concentration in digoxin intoxication.

Plasma digoxin measurements have proved unserviceable as a means of differentiating between toxic and non-toxic patients. In order to assess the value of a biological effect of digoxin in this discrimination, intraerythrocytic sodium and potassium concentrations were determined in 55 chronically digitalized patients of whom 10 were digoxin-intoxicated according to ECG criteria. Digitoxicity was associated with elevated intraerythrocytic sodium concentration (mean +/- SEM 19.3 +/- 1.2 versus 11.3 +/- 0.3 mmol/l, p less than 0.001) and reduced intraerythrocytic potassium concentration (94.6 +/- 2.3 versus 100.0 +/- 0.6 mmol/l, p less than 0.001) compared to non-toxic patients. Mean (+/- SEM) plasma digoxin concentrations in the two groups were 3.14 +/- 0.41 and 1.57 +/- 0.09 nmol/l, respectively (p less than 0.001). When diagnosing toxicity in chronically digitalized patients, plasma digoxin and intraerythrocytic sodium determinations showed sensitivities of 60 and 100%, respectively. The predictive values of a positive test were 75% for plasma digoxin and 83% for intraerythrocytic sodium.

Aged↗
PubMed1983

Histochemical studies on genetical control of hormonal enzyme inducibility in the mouse. VI. Effects of short term castration.

The regional histology and esterase activity of the mouse epididymis after 24, 48, and 72 hr castration is reported. Differential sensitivity to androgen deprivation among the various epithelial cell types is described, allowing of positive identification of the cell types previously observed to survive long-term castration. The possibility of an androgen binding protein, as described in the rat and rabbit, is suggested on morphological grounds. The epididymal body appears to contain a class of highly androgen sensitive cells that degenerate rapidly following castration and a second class that survive from which regeneration occurs on testosterone replacement.

Animals↗
PubMed1982

Effect of nifedipine on digoxin kinetics in healthy subjects.

Verapamil has been shown to reduce total-body digoxin clearance by 35% due to impairments of both renal and extrarenal clearances. Our study was undertaken to evaluate the influence of the related calcium antagonist nifedipine on single-dose kinetics. Nifedipine increased extrarenal clearance of digoxin from 1.09 +/- 0.30(SD) to 1.45 +/- 0.23 ml/min/kg (P less than 0.05) and reduced the total urinary recovery of the drug from 69.2% +/- 5.9(SD) to 64.3% +/- 5.2 (P less than 0.05). There were no significant changes in renal digoxin clearance, distribution, or biological half-life or in digoxin distribution volumes during nifedipine coadministration.

Adult↗
PubMed1982

Intraerythrocytic sodium and potassium concentrations during acute and chronic digitalization.

To assess the cellular effects of digoxin, intraerythrocytic sodium and potassium concentrations were measured in 17 patients during the early phase of digitalization, in 45 patients on long-term therapy and in 64 non-digitalized control patients. Acute digitalization raised intraerythrocytic sodium from 11.6 +/- 0.4 to 16.7 +/- 1.0 mmol/l (mean +/- SEM) (p less than 0.01) and reduced intraerythrocytic potassium from 100.1 +/- 1.3 to 95.9 +/- 1.8 mmol/l (p less than 0.01). These changes were strongly correlated with the steady-state plasma digoxin concentration. During a few weeks of digoxin therapy, the intraerythrocytic cation composition normalized gradually. In patients on chronic treatment, neither intraerythrocytic sodium (11.3 +/- 0.3 mmol/l) nor potassium concentrations (100.0 +/- 0.6 mmol/l) differed significantly from the values of the control group (11.4 +/- 0.2 and 99.9 +/- 0.5 mmol/l, respectively). The changes in intraerythrocytic cation concentrations, induced by acute digitalization, seem to disappear during chronic administration of the drug.

Aged↗