Search PubMed⌕ Search

Biomedical subjects

K Dietzmann

Publications and source records attributed to K Dietzmann.

At least 55 records · Page 3Linked to original sources
PubMed1997

Chloroquine effects on intrauterine and postnatal dendritic maturation of hippocampal neurons and on lipid composition of the developing rat brain.

The aim of the study was to analyse the intrauterine effects of Chloroquine on the dendritic maturation in the hippocampal region under considering of the lipid composition in brain tissue. 131 brains of rat pups from day 22 of pregnancy and 49 brains from offsprings from day 7 of life were investigated. The findings indicate changes in the geometric dendritic architecture of the CA3 neurons on the 7th day of life. The length of apical shaft, apical dendrites and basilar dendrites of the CA3 neurons showed a significant elongation (p < 0.05) under low doses of Chloroquine. Furthermore a early considerable formation of dendritic spines during the intrauterine period could be observed for CA1 spines at the day 22 p.c. A significant increase of the fatty acids, a reduced amount of sphingomyelines, cephalines and gangliosides was found. These results underline the fact of a mild toxic effect under a low dosis of Chloroquine in our model.

Administration, Oral↗
PubMed1997

Hypothalamic osteolipoma: a case report.

The authors present a case of an ossified lipoma at tuber cinerum, an incidental finding when performing an autopsy of a 61-year old male. A tight connection to right communicans posterior artery led first to the diagnosis of a calcified saccular aneurysm, but histologic examination revealed an osteolipoma consisting of mature adipose tissue and formation of bone. Intracranial lipomas are neither hamartomas nor true neoplasms, but they are more likely to be congenital malformations. The recent literature is reviewed, and the two most current embryologic concepts of the development of intracranial lipomas are discussed.

Autopsy↗
PubMed1996

Immunohistochemically detectable p53 and mdm-2 oncoprotein expression in astrocytic gliomas and their correlation to cell proliferation.

The aim of this report was to investigate the expression of the p53 and mdm-2 oncoproteins in astrocytic gliomas and to assess their interrelation to proliferating activities. Using monoclonal antibodies directed against p53 and mdm-2, these proteins were stained immunohistochemically in 60 astrocytic brain tumors with different histologic grade. Positive p53 stained nuclei were detected in 25.4% of the tumor cases. Mdm-2 staining products were only localized in 10.5% of specimens. Significant correlations could be found between p53, MIB-1, PCNA and mitotic index on the one hand, and tumor grade on the other hand. There were no clear relations between mdm-2 expression and proliferation markers. The grade of ploidy has a lower priority for the proliferating activity. In most cases mdm-2 immunoreactivity was strongly associated with a low or negative p53 expression.

Astrocytoma↗
PubMed1995

Laser-excited fluorescence studies of mitochondrial function in saponin-skinned skeletal muscle fibers of patients with chronic progressive external ophthalmoplegia.

The functional behavior of mitochondria in skeletal muscle of patients with chronic progressive external ophthalmoplegia was studied by laser-excited fluorescence measurements of NAD(P)H and flavoproteins in saponin-skinned fibers. Variations in the mitochondrial content and the presence of partially respiratory chain-inhibited mitochondria can be detected using this novel method.

DNA, Mitochondrial↗
PubMed1995

Abnormal dendritic maturation of neurons under the influence of a Tilorone analogue (R 10.874).

Tilorone analogue (R 10.874) has a close affinity to the lysosomal compartment of cells and forms a non degradable carbohydrate-lipid-drug complex accumulated within digesting organelles. Resembling biochemical and structural changes are seen in hereditary mucopolysaccharidoses accompanied with abnormal dendritogenesis. On the other hand, developmental toxicity (TERRY et al. 1992), antiproliferative effects (ALGARRA et al. 1993) and interactions with DNA (GELLER et al. 1985) are generated by tilorone. Therefore it should be interesting to know whether the amphiphilic cationic compound is able to produce an abnormal dendritogenesis as in storage diseases or an impaired arborisation of dendrites and what could be the reason for the misdevelopment. We demonstrate that there was a fetal retardation in the development of dendritic network, even under influence of low dosis of the analogue R 10.874. The dendritic dismaturation was concomitant with an increased amount of fatty acids and a slightly disarranged metabolic pathway of gangliosides. The dendritic arborisation closed the gap of retarded development between intrauterine treated and untreated rats after 7 days of postnatal drug elimination. We suppose that a fetotoxic effect and not the lysosomopathy is responsible for the reduced dendritic network.

Animals↗
PubMed1995

Expression of cathepsin D in human astrocytic neoplasias.

The authors investigate the expression of enzyme cathepsin D in human astrocytic neoplasias revealing the dependency on the grade of anaplasia of the tumor. This investigation has shown that there is a significant difference of cathepsin D-expression between the group of low malignant astrocytomas (G1 and G2) and the group of highly malignant astrocytomas (G3 and glioblastoma). Enzyme expression decreases when the grade of anaplasia increases. Parallel experiments have shown that in the investigated tumors the expression of GFAP also decreases when the grade of anaplasia increases. These results are related to the role of cathepsin D in the protein metabolism of healthy human CNS. The authors assume that in low malignant tumors, owing to the persisting and well-developed cytoskeleton, the investigated enzyme cathepsin D expresses more strongly than in highly malignant tumors, which are characterized by a heavier loss of their capability to express regular structures so that cathepsin D finds less substrate and, correspondingly, expresses less strongly.

Anaplasia↗
PubMed1994

Coexpression of epidermal growth factor receptor protein and c-erbB-2 oncoprotein in human astrocytic tumors. An immunohistochemical study.

C-erbB-2-oncoprotein and the epidermal growth factor receptor (EGFR) protein are transmembrane glycoproteins with an external ligand-binding domain and a nearly homologous internal tyrosine kinase domain. In the present study it was investigated in 63 astrocytic tumors (9 astrocytomas G1, 18 astrocytomas G2, 17 anaplastic astrocytomas G3 and 19 glioblastomas G4) whether the structural homology of both glycoproteins correlated with the coexpression in astrocytic tumor cells. The immunoreactive products were identified by a computerized image analysis. There was no expression of the EGFR-protein in low grade astrocytomas (G1, G2) measured by density of gray level. The immunoreactivity increased remarkably in anaplastic and malignant gliomas. The number of the c-erbB2-oncoprotein-reactive tumor cells increased with the progression and dedifferentiation of tumors. Significant differences could be found between low grade anaplastic astrocytoma as well as glioblastoma. The correlative analysis resulted in a significant positive homology with increasing grading level between the expression of EGFR- and c-erbB-2 protein. The trend goes in the same direction. The results emphasize that EGFR- and c-erbB-2 protein were expressed in astrocytic tumors with increased malignancy and dedifferentiation.

Astrocytoma↗
PubMed1994

[Expression of P-glycoprotein as a multidrug resistance gene product in human reactive astrocytes and astrocytoma].

The immunohistochemical detection of multidrug resistance (MDR1) gene products and their mRNA within brain tumor cells has already been described by Fojo et al. 1987. 63 specimens of astrocytomas and glioblastomas were analysed in the present study (Grading type 1 to 4) by means of the monoclonal antibody JSB1. The endothelial cells were positive only in astrocytic tumors with a grading of 1. Increasing tumor grading resulted in more positive immunological reactions in tumor cells. The most impressive reaction could be found in anaplastic astrocytoma and glioblastoma (G3 and G4). Overexpression of this P-glycoprotein, a plasma membrane component of a relative molecular mass of 170 kDa was not only found in tumor cells of anaplastic astrocytomas, but also in endothelial cells and some non-neoplastic brain diseases. Positive immunological reactions in protoplasmatic astrocytes could be demonstrated in cases of phenylketonuria (1/1), tuberculous leptomeningitis (2/2), SSPE (3/4), X-ray necrosis (1/1) and necrotizing viral encephalitis (1/4). According to this, it seems that astrocytes are able to express P-glycoprotein under the influence of some special metabolic conditions. This underlines the detoxicating function of reactive astrocytes within the total number of cells in the CNS.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1993

[Primary leptomeningeal sarcomatosis in a 26-year-old patient].

Primary malignant mesenchymal tumours were seen in 2.4 per cent of all autopsy cases with primary CNS-tumours. Primary leptomeningeal sarcomatosis is rare in this group of tumours. We discuss the rare disease on the basis of the case history of a 26-year-old patient.

Adult↗
PubMed1992

[Granulomatous vasculitis--an uncommon manifestation of herpes simplex infection of the central nervous system].

A man died at the age of 50 years, following tentative clinical diagnosis of centrotemporal brain tumour. Strongly pronounced, extended, partially necrotized haemorrhagic inflammation of the leptomeninx, considerably thickened and reaching into cerebral tissue above, was recorded from the cerebral basis on post-mortem examination. The spinal leptomeninx was involved in the inflammatory process. Severe exudative and primary productive pseudotuberculous inflammation was the histological finding, although tuberculous origin could not be confirmed by bacteriological culturing. Polymerase chain reaction with subsequent southern-blot hybridization revealed Herpes simplex virus Type I as the cause of inflammation.

Autopsy↗
PubMed1992

[Primary intracranial plasma cell granuloma. Report of two cases].

Investigation of biopsies of a suprasellar tumour in a man, 33 years of age, and a supratentorial tumour in a woman, 18 years of age, resulted in histological diagnosis of intracranial plasma cell granuloma, a rare condition. Polyclonality of the plasma cells involved in the process could be verified by immunohistochemical investigation. Chordoma was clinically assumed in the first case and meningioma in the second. Biological behaviour and dubious prognosis are discussed, with reference being made to relevant literature.

Adolescent↗
PubMed1992

[Dendrite-morphometry of lamina-V-pyramidal cells in premature brain damaged humans--a Golgi study].

Specimens from the area 10 of the frontal cortex collected out of 7 patients with severe mental retardation, aged 3 to 24 years and also 8 non-neuropsychiatric age-matched controls were processed according to the Golgi-Kopsch method. The total length of the apical side-dendrites and of the basal dendrites was measured on layer V pyramidal neurons. Compared with controls the total dendritic length of the apical side-dendrites as well as of the basal dendrites was significant reduced in the affected patients (p less than 0.001). The reduced dendritic length represents perhaps a morphological correlate to the mental dysfunction.

Adolescent↗
PubMed1992

[Qualitative studies of Fahr disease].

We investigated brain tissue from 7 deceased patients with Fahr's disease using X-ray-analysis for the determination of compositional differences between calcareous particles in different areas of brain or between the left and right sides in a brain and differences in composition of concrements in different brains. We found, in all areas of one brain no difference in elementary composition. Differences were found between different brains, two brains showed a high silicon content.

Adolescent↗
PubMed1992

[Malignant angioendotheliomatosis as a rare cause of cerebrovascular insufficiency].

Malignant angioendotheliomatosis, so called intravascular malignant lymphomatosis or angiotropic lymphoma, was found in cerebral hemispheres, spinal cord and nerve roots of a 50-year-old woman who died 4 months after onset of neurological symptoms. The pathological findings were characterised by neoplastic cells within the lumina and wall of small vessels as well as by multiple infarcts in the CNS. Vascular occlusions were caused by tumor cells and secondary changes of the wall. Positive reactions of Common Leucocyte Antigen and B-cell-markers support the idea of a lymphoid origin for the tumor cells. The differentiation to the angiocentric lymphoma as a T-cell tumor and the obscure pathogenesis of this neoplastic process must be clarified in the future.

B-Lymphocytes↗
PubMed1991

[Regeneration of the sciatic nerve in the rat modified by neurotrophic factors].

In the present study an experimental rat model is presented enabling analysis of nerve regeneration in vivo through preformed tissue holes. The tissue space allows to bridge a gap about 10 mm. The neovascularization could follow the physiological course using the way through the epi- and perineurium in the chamber. The regeneration rate was investigated with and without application of a mixture of gangliosides showing a significant difference between both groups. Gangliosides stimulated the axonal outgrowth and the restoration of well-vascularized nerve fascicles. Further investigations should examine the effects of different neurotrophic substances in the tube.

Animals↗
PubMed1990

[Innervation anomalies--mechanism of adaptation or embryonal malformation?].

After injuries innervationanomalies are observest. Are these anomalies mechanismen of adaption or an embryological malformation, is a still mansverst question. This paper tries some contributions to the answer. The use of modern muscleenzymhistochemistry in connection of histological findings of nerves in certain levels gives assertions on anomalies of innervation and mechanisms of reinnervation. After 14, 28, 56 and 112 days tissues of nerves and muscle from 66 female WISTAR-rats were investigated after various lesions. We have found in 15 not operated rats that the so called typegrouping can be a expression of reparation process after microlesions of nerve and muscle. We interpreted the anomalies as an expression of a reaction of adaption. The innervationanomalies succeeded in the fore and behind extremities of the rate indirectly. Above all embryological malformations can explain some anomalies of innervation on the fore extremities. We conclude from our results that communication among nerves and nerve bundles were developed or activated. These mechanism seems to be effective only about a short distance. We did not find a MARTIN-GRUBER-anostomosis. The findings of reinnervation of the musculature were attributed to cross-innervation, collateral and orthotope reinnervation. Generally the innervationanomalies are an expression of plasticity of the peripheral nervous system in all periods of life. In the first place we interpreted this phenomenous as adaption of nerves after injury and in the second place as embryological malformation.

Animals↗
PubMed1990

[Regeneration processes in peripheral nerves following nerve transsection].

A brief account is given in this paper of latest knowledge on regeneration in peripheral nerve following axotomy. Structural changes are discussed together with metabolic peculiarities associated with such restoration. Separate reference is made to neurotrophic growth factors and their effects.

Animals↗