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Biomedical subjects

U Engel

Publications and source records attributed to U Engel.

At least 37 records · Page 2Linked to original sources
PubMed1996

Lectin staining of renal cell tumours with special emphasis on oncocytomas.

There are conflicting results respecting the segmental tubular origin of renal oncocytomas, a type of tumour said to be highly differentiated and benign, though metastases have been described. The aim of this study was, by applying different lectins on renal cell carcinomas (n = 50) and oncocytomas (n = 12), to search for patterns which could indicate a specific segmental origin of oncocytomas and perhaps elucidate the differentiation of this tumour. The following lectins were applied: jacalin, peanut agglutinin (PNA), wheat germ agglutinin (WGA), phytohemagglutinin E (PHA-E), concanavalin A (Con A), and Dolichos biflorus agglutinin (DBA). The results show that oncocytomas are positive when jacalin, a Lectin that stains distal tubules and collecting tubules, is used, supporting the view that the tumour derives from distal or collecting tubules. The staining of the oncocytomas is generally polarized as in normal kidney tubules underlining that the tumour is highly differentiated. Two oncocytomas with aggressive behaviour showed areas with a diffuse pattern suggesting lower differentiation.

Adenoma, Oxyphilic↗
PubMed1995

From rodent glial precursor cell to human glial neoplasia in the oligodendrocyte-type-2 astrocyte lineage.

With only a few exceptions, the precursor cells representing the normal counterparts of human tumours are unknown. The comparative lack of information about the lineages involved in tissue development, and difficulties in growing many human tumors in a manner suitable for cellular biological analysis, together often make it difficult to study the differences between normal and tumor cells and to develop many of the model systems that would be useful in the study of human cancer. By applying techniques previously utilized to study glial progenitor cells, we have isolated a human glioblastoma multiforme (GBM)-derived population that expresses many properties otherwise uniquely expressed by oligodendrocyte-type-2 astrocyte (O-2A) progenitor cells. Hu-O-2A/Gb1 (for Human O-2A lineage Glioblastoma number 1) cells responded to similar mitogens and differentiation modulators as rodent O-2A progenitors, and generated cells with features of precursor cells, oligodendrocytes and astrocytes. Moreover, 1H-NMR analysis of amino acid composition demonstrated a striking conversation of types and quantities of free amino acids between the human tumour cells and the rodent primary cells. Hu-O-2A/Gb1 cells represent the first human glioma-derived population for which unambiguous lineage assignment has been possible, and our results indicate that the human O-2A lineage can contribute to one of the most malignant of glial tumours. In addition, the highly diagnostic 1H-NMR spectrum expressed by Hu-O-2A/Gb1 cells raises the possibility of eventual non-invasive identification of tumors of this lineage.

Animals↗
PubMed1994

Renal cell carcinoma: prognostic factors.

OBJECTIVE: To establish the prognostic value of a series of pre-operative, per-operative and histopathological parameters in relation to renal cell carcinoma (RCC). PATIENTS AND METHODS: This retrospective study involved a consecutive series of 76 patients (46 men and 30 women with a mean age of 65.3 years [range 44-91]) with a histologically confirmed diagnosis of RCC. Patients who were admitted over the period 1980-1984 were included. Data such as erythrocyte sedimentation rate (ESR), alkaline phosphatase level, histological tumour grade, degree of necrosis and presence of tumour vessels were evaluated in relation to actuarial survival. RESULTS: The ESR and alkaline phosphatase level at the time of diagnosis of RCC, the histological tumour grade, degree of necrosis and presence of tumour vessels on angiography were all found to affect the actuarial length of survival significantly (P < or = 0.05 log-rank test). Macroscopic tumour demarcation estimated per-operatively by the surgeon or after surgery by the pathologist, microscopic demarcation, vascular density on histological examination, tumour diameter and vascular density on angiography were found not to affect actuarial survival significantly. CONCLUSION: The value of establishing simple and reliable diagnostic indicators for patients with RCC is stressed.

Adult↗
PubMed1994

Nucleolar organizer regions (AgNORs) in primary and recurrent gliomas. A retrospective study.

To assess the diagnostic and prognostic relevance of nucleolar organizer regions (AgNORs) the silver-stained AgNOR structures of 46 human gliomas (22 primary gliomas, 21 first and 3 second recurrences) from 28 patients were counted and measured. Surgical specimens of two neuropathological centres were included in this retrospective study. The tumours were classified into 8 groups according to WHO criteria of diagnosis and grading and their state of recurrence: 1: primary glioma grade II; 2: primary glioma grade III; 3: glioblastoma grade IV; 4: first recurrence of glioma grade II; 5: first recurrence of glioma grade III; 6: first recurrence of glioblastoma grade IV; 7: second recurrence of glioma grade II and 8: second recurrence of glioma grade III. AgNOR numbers demonstrated a positive correlation with increasing histological grade. Similarly, higher levels of AgNORs were in general found in recurrent tumours compared to primary tumours with few exceptions in groups, in which few numbers only could be analyzed. The present study demonstrates the utility of evaluating AgNOR in assessing malignant gliomas and indicates that recurrences have a higher proliferative potential than original tumours. The problems of standardization of the AgNOR technique are especially crucial for the retrospective evaluation of fixed and embedded pathological material.

Adult↗
PubMed1994

[Menkes' kinky hair disease: a clinical and pathological case report with special reference to glial changes in the brain damage].

Menkes' kinky hair disease (Kinky hair disease, trichopoliodystrophy) is a rare hereditary disease of copper metabolism. In this study we report about the case of a boy with a long course of disease who died at the age of 6. The last phase of the disease was characterized by an almost uncontrollable excitation stage and later by an apallic syndrome. Clinical course and autopsy result are presented here. The protracted course obviously led to unusual neuropathological changes. In addition to the known neuronal damages an excessive reactive gliosis could be found. The unusual neuropathological course of this gliosis perhaps allows the conclusion that apart from neuronal damages disturbances of copper metabolism have an influence on the glia.

Brain↗
PubMed1994

[Limited radical approach in differentiated thyroid gland cancers. A prospective study of 107 patients].

From 1979 until 1987 a prospective study about limited radical therapy of 107 patients with differentiated cancer of the thyroid was performed. Nearly all of the tumors were occult papillary or encapsulated papillary and follicular carcinomas. The thyroid was not completely resected. Postoperative therapy consisted in TSH-suppression. After a follow-up of 7.5 (5-12) years one patient had died because of the tumor disease. Four patients had to be reoperated for lymph node metastases and then stayed free of disease as all other patients.

Adenocarcinoma, Follicular↗
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↗
PubMed1989

[Identification of the recurrent laryngeal nerve in thyroid gland surgery--a status determination].

The recurrent laryngeal nerve palsy is the most important complication in thyroid surgery. It seems to be possible to reduce the rate of palsies by consequently identifying the recurrent laryngeal nerve. A comparison of statistics out of the literature with and without identification of the recurrent laryngeal nerve shows this. A follow-up of our patients of the years 1980-1982 (1312 operations) confirms this finding.

Adult↗
PubMed1988

[Technics and complications in reinterventions on the thyroid].

In preference to the two long-established operative procedures for recurrent goitre - extracapsular and intracapsular resection - we have introduced meticulous preparation between the thin capsule around the recurrent goitre and the more solid external capsule in a procedure which combines the advantages of both older methods and avoids most of their pitfalls. The recurrent laryngeal nerves and the parathyroids are always outside the external capsule. The incidence of injury to these structures is minimised by this procedure. From 1980-1985 we performed 2575 thyroid operations, of which 165 operations were for recurrent goitre (6.4%), bilateral in 89 cases. Two patients died of cardiopulmonary complications (1.2%). Preoperative laryngeal nerve palsy was present in 21 cases, postoperative acquired nerve injuries occurred in 28 patients, all in all 31 nerve paralysis (18.8%), or 12.2% when compared with nerves at risk. Eight patients suffered laryngeal nerve palsy on both sides (five with preoperative nerve palsy on one side). Eleven patients showed normal function of laryngeal nerves on follow-up, whilst permanent nerve palsy was found in seventeen cases (10.3%), or 6.7% when related to nerves at risk. Hypoparathyroidism was found in 7 patients of which 4 cases showed permanent changes (2.4%).

Goiter↗
PubMed1988

Failure in school, family conflicts, and psychosomatic disorders in adolescence.

Adolescence is considered to be a transitory phase in the life course. It is hypothesized that failure in school, which carries the risk of an occupational and social "downward mobility" in the future life course in comparison to the family of origin, can function as a social "stressor" which has detrimental effects on the social and emotional climate within the family and manifests itself in symptoms of stress such as psychosomatic disorders. The results are based on a questionnaire survey carried out with a representative sample of 1717 students aged 13-16 in West Germany. The data support the hypotheses: psychosomatic symptom frequency is reinforced when adolescents experience failure in school and social and emotional conflict in their relationships with parents. Multivariate analysis shows that these effects are interconnected: failure in school has a direct effect on the frequency of psychosomatic disorders, and an indirect effect by influencing social and emotional conflicts in the family. The underlying causes for the tensions between adolescents and their parents are conceived in the social and economic opportunity structures of the society.

Achievement↗