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Biomedical subjects

L Gerhard

Publications and source records attributed to L Gerhard.

At least 37 records · Page 2Linked to original sources
PubMed1988

Preliminary experimental results with the nitrosourea derivative ACNU in the treatment of malignant gliomas.

Comparative studies were carried out to evaluate the cytotoxic effectiveness of the nitrosureas ACNU (Nimustine) and BCNU (Carmustine) at equitoxic dose levels in xenografts from two astrocytomas grades III/IV (Li, Re) and one oligodendroglioma grade III (Oe) on nude mice. Growth delay was measured as the endpoint. All tumours were characterized initially and at regular intervals in later passages as to their histomorphologic pattern, expression of glial fibrillary acid protein and DNA-content by means of flow cytometry. These characteristics were shown to be unchanged in our xenografts over more than 27 passages. Growth delays of 18.7 days (ACNU) and 2.4 days (BCNU) for the Li-xenograft (p less than 0.01) were observed at an LD10 for both drugs. For the Re- and Oe-xenografts, growth delays of 18.0 vs. 14.0 days (p less than 0.001) and greater than 27.0 vs. 14.2 days (p less than 0.02) were observed at an equitoxic dose of 33 mg/kg ACNU or BCNU i.p., respectively. These preclinical data suggest a therapeutic advantage with ACNU for these high grade gliomas and should encourage further experimental and clinical investigations.

Animals↗
PubMed1988

[Intracranial space-occupying processes in psychiatry--30 years' of clinico-neuropathologic catamnesis].

Despite declining frequency of postmortem examinations in mental hospitals no corresponding decline in the proportion of intracranial space-occupying lesions is observed in a 30-years retrospective study. 77.5% of these lesions were meningiomas, gliomas, metastases, and subdural haematomas. 70.4% of all 71 patients had major psychiatric abnormalities during the clinical course. In 58% of these patients no clinical diagnosis of intracranial space-occupying process was made. Reasons for the diagnostic delay and for the postmortem results are discussed. The significance of psychopathological change in the group of long-term residents in mental hospitals is stressed.

Adult↗
PubMed1988

[Therapy and prognosis of brain tumors in the 1st years of life].

37 infants with brain tumours diagnosed in the first three years of life were studied. Among the 28 histologically verified tumours were 7 ependymomas, 6 medulloblastomas, 5 cerebellar astrocytomas, 3 astrocytomas and 2 spongioblastomas of the optic nerve. Features of clinical symptoms, therapy and follow-up studies are described. 7 infants survived in long-term follow-up with good or fair quality of life. Results of treatment were satisfactory in cerebellar astrocytomas only.

Brain Neoplasms↗
PubMed1988

[Heterotransplantation of a human glioma and brain metastases in the athymic nude mouse--a preclinical model for radiation oncology. 1. Basic principles and methodology].

In spite of the great efforts undertaken in the different disciplines, the prognosis of patients with highly malignant gliomas, i.e. astrocytomas of degrees III and IV remains unfavorable. Up to now, new findings about an improvement of radiooncologic therapy methods are obtained retrospectively from the results of complex and time-consuming clinical studies. The heterotransplantation of human tumor tissue in immune-deficient nu/nu mice gives the opportunity to check preclinically the efficiency of different fractionation schemes and cytostatic drugs already. The author's experiences and therapy results are presented in order to demonstrate the possibilities as well as the limits of this in-vivo model performed with a view to clinical conditions.

Animals↗
PubMed1987

Familial glioma: occurrence within the "familial cancer syndrome" and systemic malformations.

The family pedigree across eight generations is presented with an association of osteochondrodysplasia, other skeletal abnormalities, familial glial tumours in a father and his son, colonic and other adenomatous disease, and pigment changes. This family cluster of diseases is considered to be a dysontogenetic process with blastomatous features and grouped within the phakomastoses. A review of the literature indicates that some "familial gliomas" show additional malformations, thus resembling phakomatoses. Others are found to be members within a "familial cancer syndrome". A trait of "hereditary glioma" apart from these syndromes is difficult to identify, especially if only sibships are considered which are likely to share common environmental factors.

Adolescent↗
PubMed1987

Optic nerve trauma: clinical, electrophysiological and histological remarks.

18 patients with post-traumatic visual disease of the optic nerve are presented. In the post-traumatic stage, visual evoked potentials were monitored. In amaurosis there was a high incidence of midface or frontobasal fractures. The severity of the trauma is not correlated with the severity of visual deficits. Flash evoked potential (FEP) findings were different: In most cases there was a correlation of clinical and FEP findings. In some we found false positive potentials in the acute stage. In smaller visual field deficits the alterations of FEP could not be correlated with the clinical disorders. FEP alterations depended on time. The pathophysiological mechanisms are discussed in regard to the pathological findings in 51 unselected autopsies with an investigation of the visual pathway from the intraorbital optic nerve to the visual cortex. Because of the different morphological alterations the clinical, neurological and ophthalmological examination should be followed by standard CT scanning to evaluate intracranial haematomas and by CT scanning with thin slices of the optic nerves and the soft tissue of the orbit. Visual evoked potentials (VEP) and in the unconscious patient, flash evoked potentials (FEP) do not give much more security for therapeutic decisions in comparison with former times. The histological findings do not support the hypothesis that operative decompression is successful.

Accidents↗
PubMed1983

[Craniocerebral injuries in childhood].

Causes of head injury in childhood depend on age. In contrast to the adults there are differences in pathophysiological mechanisms and in the site of lesions. Brain stem disorders are more frequent, superficial brain damage is less frequent than in children. Multiple lesions of the limbic system are as well important as those ones of the mesencephalon. Most of the cases of apallic syndromes in childhood can be due to these lesions.

Accidents, Traffic↗
PubMed1983

[Histological changes in the superficial temporal artery and their significance for extracranial-intracranial bypass operations].

To obtain criteria for assessing the "suitability" of an extracranial artery to be used as a donor artery in extracranial-intracranial bypass operations we examined first of all the histological changes in 103 temporal arteries of patients on whom EC/IC bypass surgery had been performed. The intima, which consists of one to two cell layers in adolescents, thickens in the course of the following decades locally or concentrically, in some cases incorporating elastic elements during the process. No arteriosclerotic plaques were seen. The originally continuous, plicated lamina elastica interna shows increasing defects in continuity in the course of the aging process, as well as loosening up to the point of fragmentation, especially in the field of the intima padding. The tunica media which is at first 30-80 mu thick, continuous to thicken in the course of life; in 60-year old persons it attains a thickness of approximately 200 mu. The changes described here occur 1.) in men in a particularly characteristic age-dependent manner; 2.) not earlier than in healthy persons, as far as the patients studied by us seem to show; and 3.) do not show any dependence on the vascular process described in this article.

Adult↗
PubMed1981

Diffuse and multicentric brain tumors -- correlation of histological, clinical and CT appearance.

In 14 cases of diffuse astrocytoma, glioblastoma and cerebral lymphoma CT was compared to the gross anatomy and their histology at corresponding levels. Diffuse spread of tumor even in areas of considerable increase of cellular density are not recognizable in CT including application of contrast medium. Circumscribed and frequently multiple foci inside of diffuse areas of gliomatosis may have necrosis and extensive vascular changes including haemorrhage. These foci alone are demonstrable by pathological changes in CT and may suggest multiple metastatic growth or vascular lesions. True unconnected multiple lesions in gliomas are rare as can be demonstrated by intensive histological investigations but occur in cerebral lymphomas.

Aged↗
PubMed1981

Morphological studies in malignant tumors of the peripheral nervous system (neurofibrosarcoma, malignant schwannoma, schwann cell sarcoma).

9 cases of malignant tumors of the peripheral nerve sheaths have been observed and their morphology including ultrastructures have been studied. 5 cases could be classified as neurofibrosarcomas, I as a Schwann cell sarcoma. Another cases may be grouped with the melaninproducing Schwann cell sarcomas and 2 cases with the "epitheloid Schwann cell sarcomas". The latter group, their separation or their connection to soft tissue sarcomas and to the "medullo-epitheliomas" of peripheral nerves are discussed.

Adult↗
PubMed1981

Multiple meningiomas. Clinical and computer tomographic observations.

The same histological types of tumor are found in multiple as in solitary meningiomas. Multiple meningiomas cannot be considered in every case to be a forme fruste of von Recklinghausen's disease. The incidence of multiple meningiomas in this paper is higher than had been reported before the introduction of computer tomography (CT) into clinical practice. The number of tumor nodes is determined more accurately by CT than by angiography because tumors are detected in patients without neurological deficit. CT has limitations in the verification of small meningioma nodules near the base of the skull and in the differentiation of multiple meningiomas from meningeal meningiomatosis or primary meningeal sarcomatosis.

Adolescent↗
PubMed1981

Follow-up studies in the posterior fossa in children using computerized tomography.

Tumours in the posterior fossa in children only present minor problems in diagnosis since the introduction of the computerized tomogram, but in postoperative follow-up studies it is rather difficult to distinguish between the various findings in the posterior fossa. This holds true especially for medulloblastomas and ependymomas. Operative changes in the anatomical structures, metal-clips, scar-like changes, post-radiation sclerosis and other findings are reasons why it is almost impossible to diagnose early recurrence of these tumours. In order to obtain more information after operation, CT findings were studied in 36 children with tumours in the posterior fossa. The findings are summarized and discussed.

Astrocytoma↗
PubMed1980

Experimental hypothalamic dysfunction in dogs.

The authors demonstrate an experimental model in dogs developed in order to study endocrine disorders as a result of suprasellar space occupying lesion. Fogarty balloon catheters were inserted in dogs below the optic chiasm and filled with contrast medium. The study of thyroid function shows that initially reversible hypothalamic hypothyroidism develops and that in a second stage most animals develop chronic thyroid dysfunction which is irreversible even after careful removal of the experimental tumor. The clinical symptoms correlate with these findings. Morphological examinations prove the fact that the hypothalamic disorders are due to disturbances of the blood-brain-barrier in the hypothalamus following hypothalamic compression and decompression.

Animals↗