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Biomedical subjects

U Engel

Publications and source records attributed to U Engel.

13 recordsLinked to original sources
PubMed1992

Safety effects of speed reducing measures in Danish residential areas.

On May 1, 1977 a new code was introduced into the Danish Road Traffic Act. The result was a change in layout and speed limits in a great number of residential streets; in most cases the streets were transformed into 30 km/h streets and in few cases into 15 km/h streets. In addition to speed signs, both types of streets were equipped with speed reducing measures. Based on experiences from a selection of experimental streets, mostly 30 km/h streets, different, but very positive effects were found. Overall there was a reduction in the mean speed in these areas of 11 km/h. On the 223 km, 30 km/h streets there was a reduction of 77 accidents and 88 casualties within a period of three years. These reductions were caused by the implementation of speed signs, speed reducing measures, and a reduction in traffic. On the basis of 44 experimental streets, where traffic was recorded both before and after the changes, the reduction in risk of casualties, i.e. the number of casualties per road user km, was 72%, while the risk of accidents seemed to be unchanged. Considering serious injuries alone, a very high reduction of 78% was found. Accidents included in the study consist of all police reported accidents, i.e. accidents with personal injury as well as damage only accidents.

Accidents, Traffic↗
PubMed1992

Myocardial perfusion at fatal infarction: location and size of scintigraphic defects.

In a consecutive study of myocardial scintigraphy in acute ischemic syndrome, four patients had 99mTc-hexamibi injected intravenously before they developed fatal cardiogenic shock. Planar scintigraphy was performed after death. Slices of the hearts after autopsy were analyzed for scintigraphic and pathoanatomic abnormalities. Location of perfusion defects in planar views of the heart was in good agreement with the scintigraphied, sliced sections. The extent of infarction judged from inspection and formasan staining was much smaller (7%-40% and 6%-43% of the total slice area) than found at scintigraphy, where 83%-92% of the myocardium showed ischemia as defined by a 99mTc-hexamibi uptake below an arbitrary limit on half maximum uptake. Myocardial hypoperfusion might thus aggravate the functional impairment at myocardial infarction and lead to cardiogenic shock.

Aged↗
PubMed1992

[The morphology of hemostasis failure in gliosal brain tumors].

A retrospective study was conducted into 37 brains of patients, who had died of Grade 2-4 glioma. For assessment of morphological signs of hemorheological failure, microcirculation was checked by H & E, Klüver-Barrera, and Goldner staining as well as by staining for fibrin, using a modified technique according to Zerbino and Lukasewitsh. Microthrombosis was recorded from 30 in the above 37 brains, all of them related to patients with Grade 3 glioma and glioblastoma. Fibrin thrombi represented the predominant variant of microthrombosis. They exhibited differentiated characteristics depending on their localisation in the central and the peripheral regions of the tumour or in surrounding brain tissue. Also included in the study were rates of vascular proliferation and types of necrosis as well as relations between these and microthrombi. The role played by microthrombi in such cases of glial tumours is discussed in some detail.

Adult↗
PubMed1992

[Aneurysm at the base of the brain and tuberous sclerosis].

Reported is the rare case of intracranial aneurysm in a boy aged one year with tuberous sclerosis. Inconspicuous development in the first few months after birth was followed, in the sixth month of age, by aggravating manifestation of convulsive seizures which were clinically diagnosed as tuberous sclerosis. Rapid progression of the clinical pattern was preterminally followed by cerebral haemorrhage which was caused by circumscribed, partially purulent arteritis along with formation of a mycotic aneurysm on the anterior segments of the arterial circle of Willis. The development of this aneurysm is discussed in conjunction with the morphological and clinical findings of tuberous sclerosis.

Aneurysm, Infected↗
PubMed1991

Eosinophilic renal cell tumours. A study on tumour heterogeneity with special emphasis on oncocytes.

Eosinophilic renal tumour cells are found in oncocytomas, granular cell carcinomas, clear cell carcinomas and in a recently defined entity known as "congeners of oncocytomas". Ultrastructural examination of paraffin embedded tumour tissue representing eosinophilic areas in 40 renal cell tumours was performed in order to characterize the different types of eosinophilic cells. The results showed all tumours diagnosed light microscopically as oncocytomas to be composed of cells containing abundant mitochondria. Similar cells were, however, also found in one case of a clear cell carcinoma and in one case diagnosed light microscopically as a "congener". Oncocytes may therefore be found as part of non-oncocytomas and there seems to be a gradual transition from oncocytes to other eosinophilic cells of renal cell carcinomas. Preoperative subclassification of renal cell tumours based on small biopsy specimens is thus of limited value.

Adenoma↗
PubMed1991

[Diffuse primary leptomeningeal gliomatosis].

A woman died at the age of 22 years. Lifetime diagnosis had been inflammatory arachnopathy. The course of the disease had taken at least 6 years. Autopsy revealed primary diffuse leptomeningeal astrocytoma of the brain and spinal cord without neoplastic foci in the parenchyma of the central nervous system. Patchy dystrophic calcifications were recorded from the cerebral and cerebellar cortex.

Adult↗
PubMed1990

The aortic wall: an in vitro study of the double-line pattern in high-resolution US.

An in vitro study of macroscopically normal aortas from human cadavers was performed with high-resolution ultrasound (US). Rectangular pieces of 10 fresh aortas were submerged in saline solution and scanned from the intimal side. On US images a characteristic double-line pattern, consisting of an inner and an outer echogenic line separated by a relatively hypoechoic line, was seen. This configuration was initially interpreted as tunica intima, tunica media, and tunica adventitia. The thickness of each layer on the US images was measured by means of a computer-assisted procedure and on histologic specimens was measured by means of stereomicroscopy. The correlation between the two measurements was poor. Experiments in which intima and part of the media were removed did not change the US appearance. Plexiglas, metal plates, and plastic foil showed a similar double-line pattern. A needle experiment disclosed that the inner echogenic and the hypoechoic lines were displayed in front of the true water-tissue interface, which was represented by the outer echogenic line. The authors conclude that the double-line pattern is thus an artifact.

Aorta↗
PubMed1990

[The necessity of intraoperative identification of the contralateral lobe in "struma uninodosa"].

Between July 1st, 1988 and July 31st, 1989 we registered 74 consecutive patients with a unilateral goitre. In all these patients the preoperative sonography showed no pathologic finding in the contralateral lobe of the thyroid. In 16 cases we found and resected nodules in the lobe, which was supposed to be normal. A consequent exposure of the whole thyroid gland, independent of the preoperative sonographic finding, principally is necessary. So, the rate of "false" goitre recurrences might be decreased.

Adenoma↗
PubMed1976

[The systolic time intervals in functional disorders of the thyroid: a simple and fast screening test].

The systolic time intervals (LVET, PEP, and ratio LVET/PEP) were determined in 53 patients presenting with signs or symptoms of thyroid dysfunction. Patients with clinical evidence of congestive heart failure, with arterial hypertension or old myocardial infarction, and patients receiving cardioactive drugs, were excluded from the study. Thyroid function was evaluated by means of T3-RIA, serum thyroxin and TRH stimulation test.

Adult↗
PubMed1976

Presence of muscarinic inhibitory and absence of nicotinic excitatory receptors at the terminal sympathetic nerves of chicken hearts.

Nicotine (2 X 10(-4) M) or acetylcholine (5.5 X 10(-4) M) in the presence of 3 X 10(-6) M atropine did not increase the rate or amplitude of contraction in isolated atria or ventricular strips of the chicken heart; both drugs also did not cause an output of noradrenaline or adrenaline and did not evoke antidromic discharges in the right sympathetic nerves of isolated perfused chicken hearts. In contrast, "high K+-solutions" evoked an output of noradrenaline and adrenaline and caused a burst of antidromic discharges. Dimethylphenylpiperazine (DMPP; 3.1 X 10(-4) M), by a tyramine-like action, elicited a small output of noradrenaline and increased rate and amplitude of contraction" but did not evoke antidromic discharges. The noradrenaline output caused by DMPP was not reduced by lowering the extracellular Ca2+ concentration from 1;8 to 0.1125 mM.-Acetyl-choline (10(-5) and 10(-4) M)inhibited the noradrenaline and adrenaline outputs evoked by electrical stimulation of the right sympathetic nerves (3 HZ, 1 ms, 30 V); the inhibition was blocked by 3 X 10(-6) M atropine.-It is concluded that the terminal parts of sympathetic nerves of the chicken heart possess muscarinic inhibitory receptors but lack nicotinic excitatory receptors. Thus prejunctional nicotinic receptors are not an integral part of the terminal sympathetic neurone otherwise they would be present at this neurone in all species.

Acetylcholine↗
PubMed1975

[Proceedings: The echocardiogram in the differential diagnosis of mitral valve insufficiency].

54 patients with mitral incompetence of varying origin have been studied by echocardiography. Echocardiography was usually not helpful in the diagnosis of pure mitral incompetence of mixed mitral valve lesions. However, it proved to be a sensitive method for recognition of the typical anomaly in "mid systolic click/late systolic murmur syndrome", which is ballooning of one or both leaflets toward the left atrium (17 out of 22 patients). The echo was equally useful for documentation of an abnormal systolic motion of the anterior mitral leaflet toward the septum, which was found in 7 of the 11 studied cases of hypertrophic obstructive cardiomyopathy.

Echocardiography↗