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Biomedical subjects

F Kersting

Publications and source records attributed to F Kersting.

At least 37 records · Page 2Linked to original sources

Diagnosis of dissecting aortic aneurysm with suprasternal echocardiography.

A 33 year old woman with Marfan's syndrome and aortic root dissection was studied with precordial and suprasternal echocardiography. The precordial approach revealed some typical features of aortic root dissection. With suprasternal echocardiography it was possible to visualize the characteristic diagnostic feature of this disease: within the aortic lumen an m-shaped pattern--the aortic intimal flap--moving downward to the posterior aortic wall during systole. The diagnosis was confirmed with aortic cineangiography and intraoperative findings. Thus, suprasternal echocardiography can be a useful method of detecting aortic root dissection, especially in patients with aortic arch dissection alone.

Adult↗

Enhanced elimination of warfarin during treatment with cholestyramine.

1 The elimination and anticoagulant activity of a single intravenous dose of warfarin (1.0-1.2 mg/kg) without and with concomitant cholestyramine treatment (about 4 g three times daily) was studied in five healthy male subjects. 2 Cholestyramine treatment decreased the biological half-life of plasma warfarin (from a mean value of 2 days -1.3 days) and increased the total clearance of this drug (from a mean value of 37 ml kg-1 day-1--53 ml kg--1 day--1). 3 The total anticoagulant effect per dose of warfarin, as measured by the area under the effect v time curve, was also reduced by cholestyramine (average reduction of about 25%). 4 Warfarin possibly undergoes enterohepatic recycling in man which can be interrupted by cholestyramine.

Adult↗

Site of action of methyldopa in lowering the blood pressure in man.

1. Methyldopa was administered to hypertensive patients in association with two different inhibitors of dopa decarboxylase, one of which, carbidopa, scarcely penetrates the central nervous system while the other, benserazide, penetrates the central nervous system when given in high doses. 2. The evidence suggests that in man, as in animals, the predominant action of methyldopa is mediated by the formation of methyldopamine and methyl-nor-adrenaline within the brain.

Benserazide↗

[Fully automatic computer-analysis of electrocardiograms in clinical routine (author's transl)].

A fully automated Ecg recording and interpretation system (Hewlett Packard HP 5) consisting of a central computer and two peripheral units was evaluated during a four-month period. Ecgs were transmitted via public telephone lines, as was the report from central station to peripheral recording and print-out unit. Within a few seconds after recording and print-out unit. Within a few seconds after recording and transmission a preliminary report is available in printed format. The transmitted Ecgs are stored at the central computer and are being retrieved and evaluated manually there. Three cardiologists read the tracings and furnished final reports. 468 Ecgs were thus compared in our test time of 10 days for statistical evaluation with the following results: 1. 73.1% of all statements were read correctly by the computer. 2. There is a large range of diagnostic accuracy between 0% and 100%. 3. The evaluation of Ecg changed by cardiologists reflects the individual experience of the controllers regarding the Ecg statements as well as computer-dependent possibilities like modification etc. of Ecg. 4. As an example the diagnosis "myocardial infarction" is compared with other Ecg computer programs by means of a quality index calculated from sensitivity and specificity: HP 5 with 158.5 points reaches a similar level as the Pipberger program with 162.6 and the Bonner with 159.5 points. 5. Referring to false negative results this program is acceptable in all diagnostic groups with ca. 8%, except conduction defects with 17.7%. 6. Referring to false positive results the diagnostic groups myocardial infarction/ischemia and conduction defects are not satisfactory with 36.5% and 23.4%. 7. In all the tested system seems to be very useful in routine Ecg interpretation of bigger hospitals.

Cardiology↗

Uremic cardiomyopathy: studies on cardiac function in the guinea pig.

The effects of creatinine (5.6-22.6 mg/100 ml), guanidinosuccinic acid (8.7-35.2 mg/100 ml) and of urea (60-600 mg/100 ml) on the mechanical function and oxygen consumption in isolated guinea pig hearts have been assessed. None of the parameters measured (dp/dt max, dp/dt min and Q O2) was significantly affected by creatinine or guanidinosuccinic acid. However, urea significantly reduced mechanical activity and caused a marked increase of oxygen consumption, indicating impairment of heart function expressed as a diminution of the ratio formula (see text). Pretreatment with creatinine and guanidinosuccinic acid did not alter the effect of norepinephrine on mechanical activity and oxygen consumption when compared with the effects of norepinephrine (1 X 10(-8) g/ml and 1 X 10(-7) g/ml) given alone. In contrast, urea pretreatment lowered the norepinephrine induced increase of left ventricular pressure rise/fall and of oxygen consumption. In addition, reduction of the increase in the ratio formula (see text): after urea perfusion indicates diminution of the "economic" effect of norepinephrine.

Animals↗

Clinical and cardiovascular effects of alpha methyldopa in combination with decarboxylase inhibitors.

The peripheral decarboxylase inhibitor carbidopa, given (100 mg/day) for 6 wk in a double-blind trial, lowered supine diastolic pressure of 10 patients with essential hypertension treated with alpha methyldopa by a small (6 mm Hg) but significant (p less than 0.05) amount. Large doses of benserazide (1.5 gm) did not modify the hypotensive effect of 1.0 gm of alpha methyldopa in untreated hypertension but significantly reduced the central nervous side effects of sedation and dry mouth. These studies indicate that extensive peripheral decarboxylation is not necessary for alpha methyldopa to lower blood pressure and would be compatible with the central nervous site of hypotensive action of this drug.

Adult↗

Cardiovascular effects of a new inotropic drug in dog and normal man.

Cardiovascular effects of 1-butyl-3(1-(6,7-dimethoxyquinazolin-4-yl) piperidin 4 yl urea) (BDPU) were studied in 16 anesthetized dogs and in 7 healthy male volunteers. In animal experiments intravenous doses of 100, 250, and 500 mug/kg/min produced dose-related, significant increases in cardiac output and peak left ventricular dp/dt. No changes in heart rate and blood pressure occurred at 100 mug/kg/min, whereas higher doses caused falls in both systolic and diastolic blood pressures, accompanied by significant rises in heart rate. Inotropic effects could also be demonstrated in man. Changes of the systolic time intervals were dose-related and began at 64 mug/kg/min. At 250 mug/kg/min, the highest dose administered, the pre-ejection period decreased by 14.8 +/- 4.42 msec and its ratio with left ventricular ejection time by 0.049 +/- 0.017 against their respective control values (p less than 0.01). In contrast to animal experiments, no hypotension or tachycardia was observed in any subject. Pharmacokinetic studies showed a plasma elimination half-life of 76 +/- 3 min (mean +/- SE). There were no subjective side effects and standard laboratory tests were not altered, but there was a slight but significant rise in the urinary enzymes, lactic dehydrogenase (LDH) and glutamic oxaloacetic transaminase (GOT), which persisted up to 7 days.

Animals↗

A comparison of cardiovascular effects of dobutamine and isoprenaline after open heart surgery.

In a cross-over study, the cardiovascular effects of dobutamine were assessed in 11 patients who had undergone operation for replacement of the mitral or aortic valve approximately four hours earlier. In 9 of these the effects of isoprenaline were assessed for comparison. Dose-response curves were obtained using four dose levels of dobutamine in the range 1.25-10 mug/kg per min and of isoprenaline in the range of 0.005-0.04 mug/kg per min. Both drugs produced similar dose-dependent increases in heart rate and cardiac output and a dose-dependent decrease in peripheral resistance. Mean arterial pressure was only slightly increased by either drug. The positive inotropic effect of dobutamine was confirmed, but the chronotropic effect was not significantly different from that of isoprenaline. This contrasts with the findings of previous studies, and possible reasons for this are discussed.

Adolescent↗

Antihypertensive effects, plasma levels and beta-adrenergi blocking activity of racemic and dextrorotatory propranolol in man.

In hypertensive patients, whose blood pressure was decreased by racemic propranolol, the dextrorotatory isomer had no antihypertensive effect. The differences in antihypertensive activity of racemic and dextrorotatory propranolol cannot be explained by different plasma levels. The data indicate that the hypotensive effect of propranolol is due to beta-receptor blockade.

Blood Pressure↗