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D Overkamp

Publications and source records attributed to D Overkamp.

29 records · Page 2Linked to original sources
PubMed1992

Simple computer-assisted diagnosis of acute myocardial infarction in patients with acute thoracic pain.

In order to minimize the initial diagnostic uncertainty in patients suspected of having acute myocardial infarction, we prospectively extracted predictive variables from previous history, ECG, and clinical chemical parameters of 87 patients, who were admitted for acute thoracic pain. The variables thus extracted were: Thoracic pain in previous history, duration of pain, white blood cell count, blood glucose, creatine-kinase, and S-T elevation in the ECG. These parameters were used for formulating a mathematical model based upon univariate and multivariate statistical methods. The sensitivity of the model in the study population was 95% and the specificity 77%. Correct classification was achieved in 89% of cases. In a second phase, the prognostic index was prospectively evaluated in a second set of 122 consecutive patients. In this test population, the sensitivity was 89% and the specificity 86%. 87% of patients were classified correctly.

Adult↗
PubMed1991

Selected ion monitoring gas chromatography/mass spectrometry using uniformly labelled (13C)glucose for determination of glucose turnover in man.

An optimized method is described for the mass fragmentographic determination of uniformly labelled (13C)glucose in human plasma using a butylboronic acid acetate derivative, and capillary gas chromatography. The advantages of the method are the ease and speed of the derivatization procedure, the small sample size, high precision (interassay coefficient of variation 5.7%), and applicability of a relatively low-cost mass spectrometer. This method allows glucose tracer experiments to be performed in man using the bolus injection technique, necessitating analysis of many samples. The results on glucose turnover obtained in a clinical experiment were in full agreement with previously published data.

Adult↗
PubMed1991

Different awareness of hypoglycaemia induced by human or purified pork insulin in type I diabetic patients.

Recently, there have been reports on a diminished awareness of hypoglycaemia after a switch from purified pork insulin (PPI) to human insulin (HI) in insulin-dependent diabetes mellitus (IDDM). To clarify this phenomenon we investigated nine IDDM patients without signs of autonomic neuropathy. After an overnight euglycaemic clamp, blood glucose was lowered to hypoglycaemic levels by means of an artificial pancreas (Biostator) on 2 days. Insulin was used in a double-blind, randomized, cross-over fashion, either PPI or HI. The symptomatology and the hormonal counterregulation of developing hypoglycaemia was recorded. Venous concentrations of free insulin, cortisol, glucagon, growth hormone and the prevailing blood glucose were similar under both insulins. Eight out of nine IDDM patients felt more symptoms and at a higher blood glucose concentration under PPI than under HI. The first symptom of developing hypoglycaemia appeared at a mean blood glucose concentration of 61.1 +/- 5.4 mg.dl-1 under PPI and 44.4 +/- 5.3 mg.dl-1 under HI respectively (P less than 0.05). We conclude that HI may cause symptoms of hypoglycaemia to appear later and with a lesser number in comparison to PPI.

Adult↗
PubMed1990

Symptoms of hypoglycemia--a comparison between porcine and human insulin.

For more than 2 years now it has been controversially debated whether awareness of hypoglycemia is reduced when type I diabetic patients are switched from porcine to human insulin. In order to address this question, we studied nine C-peptide negative diabetics (age 27.6 years, Broca index 106%, duration of diabetes 5.7 years, HbA1, 8.8%) in comparison with eight healthy volunteers (age 22.4 years, Broca index 104%). Following euglycemic monitoring overnight, a controlled hypoglycemia was induced by altering the algorithms of the Biostator. This was done in a double-blind, cross-over fashion using porcine or human insulin on 2 nonconsecutive days. There were no differences between the results obtained with respect to the time course of the study, blood glucose, amount of insulin infused, and concentration of venous free insulin achieved. Of the nine diabetics, eight were aware of hypoglycemia at a higher blood glucose level under porcine insulin. The first symptom of hypoglycemia was perceived at a mean blood glucose level of 61.1 +/- 5.4 mg/dl under porcine insulin and of 44.4 +/- 5.3 mg/dl under human insulin (P less than or equal to 0.05). Thirty symptoms were noted under porcine insulin exclusively or preferentially as opposed to only eight which were observed exclusively or preferentially under human insulin. The healthy volunteers evidenced fewer symptoms at lower blood glucose concentrations than the diabetics. The clear difference between human and porcine insulin could not unequivocally be reproduced in this group.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Exercise and insulin requirements.

In order to facilitate the management of sports and work for insulin injecting diabetic patients we analyzed 6 different situations: 1) In the morning before injecting insulin stepwise increasing bicycle ergometry until exhaustion with a duration of less than one half hour may be performed without previous reduction of insulin or additional oral carbohydrates. Maximal work load can thus be determined with ECG monitoring. After insulin injection we advise our patients to estimate their reaction by calculating with exercise units. One exercise unit equals 20 minutes of half maximal exercise or one hour of 30% maximal exercise. 2) Performing one exercise unit the diabetic will have to anticipate a blood glucose reduction of -60 mg/dl. In order to maintain normal blood glucose levels he will have to reduce the regular insulin bolus 3) in the morning by -3,3 IU or 4) by -1.7 IU in the evening or he should 5) take +12 g of oral glucose (quickly absorbable carbohydrates). 6) A reduction of basal rate (CSII) or NPH insulin (ICT) is not advisable for exercise up to 3 hours. On the basis of these mean values every diabetic patient has to monitor blood glucose during exercise and adapt the measures to his individual reactions.

Adult↗
PubMed1988

Between and within subject variation of the first phase insulin response to intravenous glucose.

Eight normal subjects underwent two intravenous glucose tolerance tests to determine the between and within subject variation of the first phase insulin response. Variability was represented by the coefficient of variation. The between subject variation for the incremental 0-10 min insulin area was 58%, and the within subject variation was 22% (median value), range 3-55%. The variation of the first phase response expressed in four different ways was compared. The total and incremental (above fasting levels) 0-10 min areas provided less variable results (variation 52 and 58%) than the 1 + 3 min insulin levels (variation 72%) or mean of the incremental 3-5 min insulin levels (variation 66%). The ratio of the incremental 0-10 min insulin to glucose areas was as variable (variation 53%) as the insulin responses alone. The variability of insulin responses to intravenous glucose severely limits their value as early predictors of B-cell failure.

Adult↗
PubMed1988

Production of polyclonal antibodies in ascitic fluid of mice: technique and applications.

Balb/c mice immunised intraperitoneally with insulin developed significantly higher antibody concentrations in their serum than mice immunised subcutaneously. The antibody response was dose related, 50 ug amounts being more effective than either 20 ug or 5 ug amounts. In contrast, the antibody titres in the ascitic fluid of mice immunised with growth hormone were significantly higher after 5 ug when compared to 25 and 100 ug amounts. Repeated intraperitoneal injections of an emulsion of sheep IgG or human growth hormone in complete Freund's adjuvant, together with a single intraperitoneal injection of Pristane, induced ascites formation in most mice within 5 weeks. Up to 90 mL could be obtained from a single mouse by abdominal tapping, and the antibodies derived from the ascitic fluid proved suitable for application in a radioimmunoassay.

Animals↗
PubMed1987

[Effect of rapid atrial pacing on left ventricular ejection fraction in patients without organic heart disease].

Pacing-induced decrease of left ventricular ejection fraction (LVEF) in patients with coronary artery disease has been proposed as a sign of myocardial ischemia, whereas a slight increase or no change is speculated to be the normal response to rapid atrial pacing. The studies of the pacing-induced effects in normals, however, are of limited value, because of either inhomogeneous patient population or different, mainly non-invasive, methods for determination of LVEF. It was therefore the aim of the present study to assess the pacing-induced changes of left ventricular ejection fraction in a homogeneous group of patients. In 10 patients (mean age: 48 +/- 2 years) with normal coronary arteriograms and normal LV-function at rest, rapid atrial pacing was performed stepwise to a maximal pacing rate of 150 beats per minute. In all patients left ventricular end-diastolic pressure LVEDP and time constant of relaxation period tau decreased, while the parameter of contractility Max Dp/dt increased due to increase in heart rate. Furthermore, there was no limited coronary reserve or myocardial lactate production during atrial stimulation as a sign of pacing-induced ischemia. In all patients biplane ventriculography was performed at rest and during maximal stimulation. While end-diastolic volume index EDVI decreased in every patient (71 +/- 5----42 +/- 4 ml/m2, p less than 0.005) and systolic volume index did not change (17 +/- 2----14 +/- 2 ml/m2, N.S.), there was a significant decrease of ejection fraction from 75 +/- 2 to 66 +/- 3% (p less than 0.005). Basal heart rate, age, sex or basal ejection fraction did not influence the response of ejection fraction to rapid atrial pacing. Even after drug-induce afterload reduction there was a significant pacing induced decrease of ejection fraction.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMedDate not supplied

Successful treatment of brain abscess caused by Nocardia in an immunocompromised patient after failure of co-trimoxazole.

Disseminated infection caused by Nocardia asteroides is a fairly rare entity occurring mostly in immunocompromised states. Metastatic brain abscesses are a frequent and ominous complication. We report on a patient whose underlying disease was stage II pulmonary sarcoidosis. He acquired disseminated N. asteroides infection while on immunosuppressive therapy with prednisolone. After the generally recommended therapy with co-trimoxazole (trimethoprim/sulfamethoxazole) proved ineffective in controlling his brain abscesses, the lesions of the central nervous system completely resolved under a combination of oral rifampicin with i.v. imipenem, followed by oral rifampicin and ampicillin/clavulanic acid.

Adult↗