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Biomedical subjects

H Stiegler

Publications and source records attributed to H Stiegler.

81 records · Page 5Linked to original sources
PubMed1981

[Pharmacokinetics of theophylline and caffeine in premature infants with apnea (author's transl)].

In apneic premature infants treated with theophylline or caffeine the pharmacokinetics of the methylxanthines were investigated. Orally applied caffeine and theophylline were rapidly absorbed reaching peak plasma levels at 1-2 and 1-4 h resp. The plasma concentration of free theophylline was significantly higher (p less than 0.001) in prematures than in adults. In prematures and adults only 5 resp. 8% of caffeine were bound to the plasma proteins. The salivary methylxanthine concentration corresponds to the plasma concentration of the free drugs. The mean plasma half-live of theophylline was 22.3 h, the clearance 28.3 ml/kg/h and the volume of distribution 0.9 l/kg. For caffeine a plasma half-live of 70.6 h, a clearance of 8.6 ml/h/kg and a volume of distribution of 0.84 l/kg was found. A first oral dose of 7-9 mg/kg theophylline or caffeine should be administered to reach rapidly effective plasma concentrations of about 10 micrograms/ml. To maintain a mean plasma concentration of about 10 micrograms/ml, a daily oral maintenance dose of 5-9 mg/kg theophylline or 2 mg/kg caffeine should be given. High concentrations of unchanged caffeine and theophylline were excreted in the urine of premature infants indicating immaturity of the metabolizing hepatic enzymes. In prematures treated with theophylline caffeine was found in plasma as a metabolite of theophylline.

Apnea↗
PubMed1980

A new operative technique for kinking stenoses of the internal carotid artery.

A method of carotid artery plication for kinking stenoses of the internal carotid artery is described. This method has been used in 13 symptomatic patients with type III kinking up to now. Satisfactory long-term results were obtained in 11 patients, one patient had to be reoperated for postoperative stenosis and one patient died after the operation from ischemic cerebral injury. It is concluded that the method is a suitable alternative to resection procedures, particularly in cases of kinking and arteriosclerotic stenosis.

Aged↗
PubMed1980

Extracranial aneurysms of the carotid artery.

Aneurysms of the extracranial carotid artery represent a serious disease because of possible cerebral embolism and aneurysm rupture. Between 1960 and 1979, 28 aneurysms of the extracranial carotid artery were seen in 27 patients at our institution. Twenty-six of these patients noticed a pulsating tumor, 12 patients had neurological symptoms; 2 aneurysms were ruptured. Five times the external carotid artery, and 3 times the internal carotid artery were ligated without neurological symptoms. After aneurysm resection, the carotid artery was reconstructed in 4 cases by direct suture, and in 2 cases by patch angioplasty. Reconstruction was accomplished with a tube-graft in 9 instances, once an extra-intracranial shunt had to be performed in advance. Two patients developed neurological deficiencies after the operation (8.7%), in one of them these were permanent. In the follow-up, 20 patients were without symptoms (87%), 3 patients died after the operation (peri-operative mortality 13%). Out of the 5 non-operated patients 2 died after a short time: one of an acute myocardial infarction and one of an extensive cerebro-vascular infarction. Two patients with asymptomatic internal carotid aneurysm refused the operation and are without symptoms for 2 and 40 years respectively. Because of the potential risks of cerebro-vascular infarction and aneurysm rupture, good results of operative treatment call for an aggressive surgical approach in dealing with extracranial carotid aneurysms.

Adult↗
PubMed1979

Functional and metabolic features of an isolated perfused guinea pig heart performing pressure-volume work.

Cardiac performance and some parameters of glycolytic and oxidative metabolism were analyzed in isolated perfused guinea pig hearts performing pressure-volume work. Perfusion medium was an oxygenated Krebs-Henseleit bicarbonate buffer (pH 7.4) which contained glucose and physiological concentrations of pyruvate and insulin. The pressure-flow relationship in the coronary vascular bed indicated autoregulation of coronary flow. Left ventricular function was influenced by aortic pressure (Pa) and venous filling pressure (Pv) in accordance with the Frank-Starling principle, i.e. stroke work increased as a function of Pa or Pv to a certain maximum and then decreased. Myocardial oxygen consumption (MVO2), on the other hand, was linearly correlated with Pa and Pv, respectively, over the entire pressure range. Efficiency of the left ventricle, therefore, increased to an optimum (16%) and decreased at higher pressures. Myocardial contents of glycogen, ATP and creatine phosphate were not markedly influenced by a change in Pa or Pv. L-Noradrenaline (0.08 micrometer, NA) stimulated stroke work and MVO2 at a all Pv tested; efficiencies reached physiologic values (21%) at high volume loads. The increased MVO2 was associated with an acceleration of pyruvate decarboxylation and lactate release up to 10- and 15-fold, respectively, at elevated but physiological NA concentrations (0.2 micrometer). Our results demonstrate that the isolated perfused working guinea pig heart compares favourably with the non-failing Starling heart-lung preparation and hearts in situ, as far as coronary function, left ventricular performance and oxidative metabolism are concerned.

Animals↗
PubMedDate not supplied

Morbidity, mortality, and albuminuria in type 2 diabetic patients: a three-year prospective study of a random cohort in general practice.

In a 3-year prospective study, the prevalence of albuminuria and its relationship to macrovascular disease, pre-existing vascular risk factors and mortality rate were studied in a random cohort of 290 patients with Type 2 diabetes mellitus in general practice. Newly occurring micro- or macroalbuminuria was associated with significantly (p less than 0.05) higher systolic blood pressure: median (IQ range) 157 (140-170) vs 150 (130-160) mmHg, in addition to higher serum triglycerides: median (IQ range) 2.71 (1.84-4.25) vs 1.84 (1.35-3.14) mmol l-1, and C-peptide levels: median (IQ range) 1.30 (0.98-2.16) vs 1.10 (0.82-1.58) nmol l-1, at 3-year follow-up. Patients with macroalbuminuria at final examination had significantly higher systolic and diastolic blood pressure, serum triglyceride and beta 2-microglobulin levels, decreased HDL-cholesterol, and a significantly higher prevalence of carotid artery stenoses and peripheral vascular disease. Patients dying from vascular causes showed significantly higher urinary albumin levels at entrance as compared to the surviving patients: median (IQ range): 42.2 (11-249.7) vs 10.4 (4.6-28.0) mg l-1, p less than 0.008, and overall mortality rate was significantly linked with the presence of macroalbuminuria (26% vs 5% in normoalbuminuric patients). A comparison between the results of the initial and the final examination indicated an overall worsening of renal variables (albuminuria: median (IQ range): female 9.5 (4.5-21) vs 13.4 (5.1-39.7) mg l-1, (p less than 0.05); male 13.8 (4.7-34.1) vs 32.6 (8.1-78.7) (p less than 0.001), despite a significant improvement in metabolic variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗