Search PubMed⌕ Search

Biomedical subjects

D Schiffer

Publications and source records attributed to D Schiffer.

At least 91 records · Page 5Linked to original sources
PubMed1991

Dystrophic neurites around amyloid plaques of human patients with Gerstmann-Sträussler-Scheinker disease contain ubiquitinated inclusions.

Dystrophic neurites have been previously observed around prionic protein-derived amyloid plaques of Gerstmann-Sträussler-Scheinker (GSS) disease. Ubiquitin (Ubq) immunohistochemistry reveals the presence of dot-like stainings around many of these plaques. In order to determine the nature of ubiquitinated deposits, we performed an immunogold electron microscope study on autoptic samples from the cerebellum of a GSS patient. Both pre- and post-embedding staining methods showed Ubq-positive dense bodies and filamentous structures, belonging to dystrophic neurites. They are analogous to ubiquitinated neuritic processes described around cerebellar amyloid plaques of Alzheimer's disease (AD). These results suggest that amyloid deposition is responsible for the degeneration of adjacent axon terminals in both AD and GSS.

Amyloid↗
PubMed1991

Chondroitin sulfate proteoglycan surrounds a subset of human and rat CNS neurons.

Chondroitin sulfate proteoglycan (CS-PG) bearing glycosaminoglycan (GAG) chains containing unsulfate (COS) and 6-sulfate (C6S) disaccharides was immunolocalized in rat and human CNS by using monoclonal antibodies (MAb) specific for the two disaccharides. The immunostaining with both MAb was restricted to the periphery of a neuronal subset in rat and human CNS. Double immunofluorescence showed codistribution of the antigens around the same neuronal population. The staining with anti-COS MAb was stronger than with anti-C6S MAb, suggesting that the proteoglycan (PG) contains mainly COS disaccharides. In different rat cortical areas, 40-60/mm2 positive interneurons were found, the visual cortex showing the highest value. In human cortex, positivity was also observed around the soma of some pyramidal cells. In the rat, positive neurons were also localized in deep cerebellar nuclei, reticular nucleus of the thalamus, and other structures of the midbrain and hindbrain. CA3 region of hippocampus and the external layer of pyriform cortex were characterized by positivity of the neuropil. Immunoelectronmicroscopy showed the antigens in the extracellular space around the neuronal soma, the synaptic elements and the cell processes of the neuropil. The neuronal surface of the soma and of the proximal dendrites were positive, but the pre- and postsynaptic membranes and clefts were negative.

Aged↗
PubMed1991

Histologic prognostic factors in ependymoma.

The prognostic value of a series of histologic signs and clinical features was studied in a series of 298 ependymomas, collected from different institutions. The distribution of tumor sites varied in relation to patient age, with infratentorial cases prevailing under 4 years. Life table univariate analysis demonstrated as highly significant prognostic factors: (1) the number of mitoses; (2) endothelial hyperplasia; (3) necrosis; (4) intracranial site; (5) age less than 4 years. Multivariate analysis by tumor site revealed mitoses cell density, age greater than 16 years in supratentorial cases, and subependymoma in infratentorial cases to be prognostically important. Comparison of the anaplastic variant with the other tumor types in intracranial cases did not show a significant difference in survival even though the median survival time of anaplastic cases was shorter. The main conclusion is that the histological criteria employed to diagnose anaplasia in ependymomas. The number of mitoses is a very important prognostic factor in supratentorial cases, whereas endothelial proliferations and necroses are much less important as prognostic factors than in gliomas.

Adolescent↗
PubMed1991

Coexpression of platelet-derived growth factor (PDGF) B chain and PDGF B-type receptor in human gliomas.

In this study we analyzed the expression of mRNA for PDGF-B and PDGF B-type receptor (PDGFrecB) in 42 biopsy specimens from human astrocytic gliomas and other brain tumors. All gliomas expressed PDGF-B mRNA at higher levels than found in peritumoral and normal nervous tissues. Levels of PDGF-B transcripts correlated strongly with those of mRNA for glial fibrillary acidic protein. Thus, the production of PDGF-B mRNA may be attributed mainly to tumoral glial cells. PDGFrecB transcripts were found in 24 out of 29 gliomas, in agreement with the hypothesis of an autocrine growth stimulation in these tumors. Moreover, mean levels of PDGFrecB expression were higher in glioblastomas than in astrocytomas and over 30-fold higher in meningiomas than in gliomas. This suggests that in gliomas PDGFrecB can be expressed also by vascular elements, in agreement with the hypothesized existence of a paracrine mechanism that may be responsible for the endothelial hyperplasias.

Astrocytoma↗
PubMed1991

Relationship between glial reaction to a stab wound and tumor development after receiving transplacental ethylnitrosourea in the rat.

Fisher 344 rats born from mothers treated with ethylnitrosourea (ENU) 50 mg/kg intravenously were injured at the 1st and 2nd month of extrauterine life by a transcranial stab. The wound affected cerebral cortex, white matter and basal ganglia. The animals were killed 15 and 45 days and 5 months after injury and cell reaction was studied histologically and immunohistochemically. Bromodeoxyuridine (BrdUrd) was administered 1 h before sacrifice and the labeled cells were evaluated. In ENU-treated rats injured at 1 month of age only minor differences were found in comparison with injured controls. In ENU rats injured at 2 months of age and killed 15 days later, a higher number of BrdUrd-labeled cells was found in comparison with controls; 45 days after injury the cell reaction acquired the aspect of a microtumor, however, no microtumor unrelated with the needle track was present. In ENU rats killed 5 months after the injury, there was no difference between injured and not injured ENU-treated rats, as far as the aspect and the number of tumors were concerned. The tumor phenotype was, thus, anticipated by the cell response to trauma in ENU rats. The interpretation is that the additional cell division, in response to trauma, anticipate not only the phenotypic, but also the cell kinetics changes, as indicated by BrdUrd labeling.

Animals↗
PubMed1991

Myoglobinuria and carnitine palmityl transferase deficiency in father and son.

A 18-year-old man had recurrent myoglobinuria following exercise and fasting. His parents originated from the same village, which has less than 1000 inhabitants. His 53-year-old father suffered from similar episodes, whereas his mother and elder brother were symptom free. Biochemical investigations on muscle and platelets disclosed carnitine palmityl transferase (CPT) deficiency in the patient and his father. His mother and brother showed intermediate CPT values consistent with their being heterozygotes. This appears to be the first report of CPT deficiency with recurrent myoglobinuria in two generations (so-called quasidominant transmission).

Adolescent↗
PubMed1991

Pathology and neuroepidemiology of the brain and nervous system.

The main contributions in 1990 to oncology of the nervous system in the fields of pathology and epidemiology are discussed in this review. In the area of pathology many articles are devoted to case series and to clinicopathologic correlations, especially for brain tumors in children, for which precise correlations are still lacking. Immunohistochemistry is widely represented in this year's literature and its contributions are directed primarily to the recognition of antigens or new antigens in the tumors, in order to reach a more appropriate classification of information on pathogenesis. Other problems were those of the relationship between angiogenesis and tumor invasion, the characteristics of tumor invasiveness, tumor immunology, host resistance, and molecular aspects. A number of papers have also been dedicated to cell kinetics and to the application of methods revealing the proliferation potential of tumors, to achieve a better prognostic formulation from biopsies. Epidemiologic studies continue to explore the incidence of tumors, especially in young patients, and the associations with exposures to different stimuli and immunosuppression.

Animals↗
PubMed1991

Ubiquitin in motor neuron disease: study at the light and electron microscope.

Several neurodegenerative diseases, including motor neuron disease (MND), are characterized by formation of abnormal cytoskeleton-derived inclusions which contain ubiquitin (Ubq). We have studied the distribution of Ubq in 26 cases of MND with light and electron microscopic immunocytochemistry. Ubiquitin-positive inclusions were found in neurons of anterior horns in most cases of amyotrophic lateral sclerosis (ALS) but were not present in other forms of MND. Ubiquitin immunoreactivity was observed in 10-15 nm intraneuronal filaments, which were not stained by antibodies to neurofilaments, and on dense bodies of dystrophic neurites throughout the neuropil of anterior horns and pyramidal tracts. Data analysis showed a trend toward lower percentage of Ubq-positive neurons in cases with longer duration of illness or lower number of neurons. A high percentage of Ubq-positive inclusions occurred in cases with an aggressive clinical course, suggesting that ubiquitination takes place at early stages of the disease.

Adult↗
PubMed1991

Ultrastructural localization of factor VIII-related antigen in endothelial proliferations of malignant gliomas.

The ultrastructural localization of Factor VIII-related antigen (FVIII/RAg) in the endothelial cells of malignant gliomas was studied with immunogold labelling on thin sections of LR White-embedded tissue. FVIII/RAg was localized in Weibel-Palade bodies (WPBs) as well as in cytoplasmic vacuoles and vesicles, and in extracellular spaces. Stained WPBs were found both in cells surrounding vascular channels and in several proliferating cells of solid buds and glomeruli. Our results confirm previous ultrastructural observations on non-neural tissues that FVIII/RAg is produced by endothelial cells and stored in WPBs. The presence of FVIII/RAg-stained WPBs in capillary buds and tufts indicates that at least some of the proliferating cells are endothelial in origin rather than pericytes. Thus, the contribution of endothelial cells to new vessel formation seems to be more substantial than previously reported.

Antigens↗
PubMed1991

Cerebellar syndrome in adult celiac disease with vitamin E deficiency.

We studied a woman with adult onset celiac disease complicated by a cerebellar syndrome that progressed despite the resolution of the malabsorption symptoms with a gluten free diet. The patient presented vitamin E deficiency and the cerebellar symptoms improved with vitamin E therapy. This case supports the possible role of this deficiency in the development of the neurological complications of celiac disease.

Adult↗
PubMed1991

Familial autosomal recessive rigid spine syndrome with neurogenic facio-scapulo-peroneal muscle atrophy.

Two sisters and a first cousin presented with rigid spine and facio-scapulo-peroneal muscle atrophy. The patients belonged to a family with two first-cousin marriages. Electromyography, muscle and nerve biopsy showed neurogenic muscle atrophy without peripheral nerve involvement. Follow up did not show progression of the disease. This is the first observation of an association of neurogenic facio-scapulo-peroneal and rigid spine syndrome. The double first-cousin marriage suggests autosomal recessive inheritance.

Adolescent↗
PubMed1991

Risk factors in motor neuron disease: a case-control study.

A case-control study of risk factors in 512 cases of motor neuron disease (MND) and 512 controls, affected by other neurological diseases, was performed. Clinical history showed a significant increase in gastric ulcer and mechanical injuries among MND cases, whereas the frequencies of operations, poliomyelitis, malignancies and autoimmune diseases were similar for cases and controls. The women affected by MND had a later menarche and an earlier menopause; therefore, the reproductive period was significantly shorter, supporting a possible role of sexual hormones in the pathogenesis of MND. The analysis of occupations showed an increased number of farmers and also of subjects exposed to chemical products among MND cases.

Adult↗
PubMed1991

Ependymoma: internal correlations among pathological signs: the anaplastic variant.

In a series of 298 cases of ependymoma, survival analysis identified some prognostic histological factors but failed to demonstrate a worse survival for the anaplastic variant diagnosed with the common criteria used for assessing anaplasia in primitive brain tumors. This finding suggests that either anaplastic ependymoma does not exist, or that the established criteria are not useful in its identification. To solve these problems, the association of histological, immunohistochemical, and ultrastructural signs in 173 intracranial cases was investigated and analyzed by means of contingency tables. Many signs had only focal distribution. Some signs, meaningful for anaplasia, such as very high cell density and number of mitoses, were found to be associated, whereas other signs usually considered indicative of anaplasia, such as endothelial hyperplasia, glomeruli, and necrosers, were not. In addition, pseudorosettes, mesodermic areas, and incomplete formation of perivascular pseudorosettes were signs associated with very high cell density and number of mitoses. Distribution of glial fibrillary acidic protein and vimentin, as well as other immunohistochemical and ultrastructural features, were not helpful, with the exception of microsettes found by electron microscopy. Our conclusion is that the anaplastic variant of ependymoma is recognizable only when some histological prognostic factors, such as cell density and number of mitoses, are maximally expressed.

Adolescent↗
PubMed1991

Lonidamine in malignant brain tumors.

Among new therapeutic modalities for both primary and secondary brain tumors, selective manipulation of metabolic pathways seems attractive. In human malignant gliomas and cell lines from a glioblastoma multiform, lonidamine has been shown to interfere with aerobic glycolysis with a decrease of lactate production by the inhibition of a mitochondrially-bound hexokinase; this selective reduction of the energetic capabilities of glioma cells would be a limiting factor for processes requiring energy, such as cell growth and recovery from potentially lethal damage after radiotherapy or chemotherapy. The activity of lonidamine in malignant gliomas after surgery in association with conventional radiotherapy is being investigated, while previous studies have suggested a limited, but clear therapeutic activity of the drug in recurrent malignant gliomas. In brain metastases lonidamine has not been effective as a radiation enhancer, but has been shown to potentiate systemic chemotherapy. Most common side effects were myalgias, testicular pain and ototoxicity with no serious organ toxicity or myelosuppression.

Antineoplastic Agents↗
PubMed1990

Ubiquitinated filamentous inclusions in spinal cord of patients with motor neuron disease.

The ultrastructural localization of ubiquitin (Ubq) in spinal cord of 2 cases of amyotrophic lateral sclerosis was studied, using immunoperoxidase and immunogold labeling on Vibratome sections or on sections cut from paraffin blocks. Two different types of ubiquitinated cytoplasmic inclusions were observed: (1) bundles composed of 10-15 nm filaments; (2) small rounded bodies without a limiting membrane. A panel of antibodies to neurofilaments (NFs) did not stain the ubiquitinated bundles, and decorated only axonal swellings. Ubq-positive filamentous deposits could be identified with inclusions previously described ultrastructurally. The absence of staining with antibodies to NFs might be due to abnormalities of the filaments, possibly because of a dysfunction of the ubq proteolytic system.

Amyotrophic Lateral Sclerosis↗
PubMed1990

Vascular response to irradiation in malignant gliomas.

The vascular response to irradiation was studied in peritumoral cortex and tumor areas in 9 autopsied cases of glioblastoma multiforme and in 10 biopsies of reoperated cases. The study was carried out by histological, immunohistochemical and electron microscope procedures. Hyaline thickening of the vessel walls with deformation and impoverishment of endothelial nuclei are the most striking features. Formation of large PAS-positive areas from the confluence of thickened vessel walls and development of a fibroblastic proliferation follow. Fibroblastic areas may entrap tumor glial cells. In PAS-positive areas a special population resembles myofibroblasts of tissue scars. Electron microscope reveals the production of collagen fibrils in and outside vessel walls. The presence of collagen III and IV is in line with the present interpretation of the mesodermic component.

Adult↗
PubMed1990

Cytochrome c oxidase and coenzyme Q in neuromuscular diseases: a histochemical study.

Cytochrome c oxidase (CCO) has been histochemically studied in 250 muscle biopsies from patients with different neuromuscular diseases. The results were compared with those obtained on serial sections stained with Gomori's trichrome and with the methods for NADH tetrazolium reductase, succinate dehydrogenase and lactate dehydrogenase. In 58 selected cases serial sections were also stained with a method demonstrating coenzyme Q (CoQ) activity. Demonstration of structural alterations was as good with CCO as with the methods for other oxidative enzymes: particularly evident were alterations of the distribution of mitochondria, such as core areas in central core and multiminicore diseases. Unstained fibers were observed in mitochondrial myopathies, in Becker, Emery-Dreifuss, limb-girdle, facio-scapulo-humeral muscular dystrophies, muscle infarction, polymyositis, motor neuron diseases and neuropathies. The histochemical method for CoQ showed only low specificity, since partial staining was also present in areas devoid of mitochondria, such as cores. CoQ deficiency was not observed in any of the 19 mitochondrial myopathies examined.

Biopsy↗