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Biomedical subjects

W Schachenmayr

Publications and source records attributed to W Schachenmayr.

At least 19 recordsLinked to original sources
PubMed2000

Neurofilament H immunoreaction in oligodendrogliomas as demonstrated by a new polyclonal antibody.

We have characterized a new polyclonal antibody against heavy chain (H) of neurofilament which can be used to demonstrate neurofilament H in normal brain tissue and oligodendroglioma cells immunocytochemically and immunochemically. Using this antibody we found neurofilament H-immunoreactive tumor cells in 13 oligodendrogliomas (6 WHO grade II, 7 WHO grade III) out of 84 oligodendrogliomas investigated (59 WHO grade II and 25 WHO grade III). Double immunolabeling and confocal laser scanning microscopy showed colocalization of neurofilament H and glial fibrillary acidic protein in certain oligodendroglioma cells. Colocalization of neurofilament and synaptophysin was observed only rarely. The results support the notion that oligodendrogliomas consists of a heterogeneous cell population displaying various stages of differentiation and dedifferentiation. The occurrence of neurofilament H-immunoreactive tumor cells in oligodendrogliomas is not related to the survival of the patients.

Adolescent↗
PubMed1999

[Axillary nerve paralysis after playing squash. A case report].

A 27-year-old otherwise healthy male presented with an isolated but complete axillary nerve palsy after excessive squash playing. When repeated electromyographic investigations showed no signs of reinnervation in the deltoid muscle, surgery was performed in order to restore nerve function. Intraoperatively, the nerve showed a short segment of thinning about 2 cm distally the nerve's origin from the posterior fascicle. As intraoperative electrophysiological testing was also negative (no electrically evoked nerve action potentials across the lesion) the suspicious nerve segment was resected and nerve continuity restored by sural grafts. Histologically, no intact nerve structures could be found at the site of the thinning. Most likely the lesion was caused by traction forces. Follow-up studies showed reinnervation of deltoid function over time.

Adult↗
PubMed1999

[Metaplastic meningioma with cartilaginous differentiation].

A meningioma with cartilaginous areas is described. The tumour arose in the region of the right sphenoid wing in a 74-year-old woman. Histologically, it showed large areas of a typical meningothelial meningioma, among which numerous cartilaginous islands and some chondroid regions, obviously of intermediate (meningothelial/cartilaginous) differentiation, could be seen. Cartilaginous tumour areas showed lower MIB1-labelling indices than typical meningioma regions, where an increased proliferative activity was seen focally. The current WHO classification lists such tumours as metaplastic meningiomas, reflecting the potential of meningioma cells for mesenchymal differentiation. Metaplastic meningiomas may show different metaplasias (xanthomatous, osseous, lipomatous, cartilaginous, etc.). Extensive cartilaginous metaplasias are very uncommon. Identification of typical meningioma areas is the key for the diagnosis of this meningioma variant.

Aged↗
PubMed1998

[Meningeal melanocytoma].

A 38-year-old man presented with an intracranial extra-axial tumour at the base of the left posterior fossa which proved to be a meningeal melanocytoma. Meningeal melanocytoma is a rare, benign melanotic tumour of the leptomeninges occurring predominantly in the posterior fossa or the upper spinal cord in adults. It shows characteristic cytologic features with isomorphic epitheliod or spindle-shaped cells, often with prominent nucleoli and a variable content of intracytoplasmic melanin. It usually lacks signs of malignancy such as high mitotic rate, necroses or infiltrative growth and shows a low labeling index in proliferation marker studies. Its immunohistological profile with S-100 protein-, vimentin- and HMB-45-positive tumour cells is similar to that of (primary or metastatic) malignant melanoma. This differential diagnosis is crucial because of the totally different therapeutic and prognostic implications. Therefore, everyone dealing with surgical neuropathology should be familiar with the rare, but clinically important diagnosis of meningeal melanocytoma.

Adult↗
PubMed1998

Prognostic implication of histopathological, immunohistochemical and clinical features of oligodendrogliomas: a study of 89 cases.

Histopathological, immunohistochemical and clinical parameters were correlated with survival in 89 cases of oligodendroglioma (65 patients with grade II and 24 patients with grade III of the WHO classification). Median survival time and 5-year survival rate were 3.5 years and 76% for patients with oligodendroglioma grade II and 0.875 years and 23% for patients with oligodendroglioma grade III. The tumor biopsy specimens were immunohistochemically analyzed for Ki 67 (MIB-1), vimentin, glial fibrillary acidic protein (GFAP), neuron-specific enolase (NSE) and synaptophysin. MIB-1 nuclear labeling index ranged from 0.0% to 33.4%; vimentin-immunoreactive tumor cells were found in 25 cases. MIB-1 nuclear labeling index and vimentin immunoreaction showed a significant statistical correlation to the 5-year survival rate of the patients. Tumors with vimentin expression (n=25) and/or high MIB-1 labeling index (n=26) had a poorer prognosis than tumors lacking vimentin expression (n=57) and/or displaying a low MIB-1 labeling index (n=56). The expression of immunoreactivity for GFAP (n=53), NSE (n=23) and synaptophysin (n=15) appeared to be of no prognostic relevance. Patients with gross total tumor resection (n=47) had a median survival time and 5-year survival rate of 3.3 years and 84% compared to 1.2 years and 42% for patients with subtotal resection (n=41). The comparison between patients who underwent surgery alone (n=53) and those who had surgery plus postoperative radiation therapy showed no significant survival benefit from postoperative radiation therapy. In conclusion, tumor grade, MIB-1 labeling index, expression of vimentin and the extent of surgery are shown to be of prognostic relevance for patients with oligodendroglioma.

Adolescent↗
PubMed1998

Multidrug resistance in glioblastoma. Chemosensitivity testing and immunohistochemical demonstration of P-glycoprotein.

Chemosensitivity of previously untreated glioblastomas to mitoxantrone, methotrexate, ACNU and BCNU was tested on cultured tissue. Sixteen of 62 tumors were partially chemosensitive in vitro. The monoclonal antibody C 219 was used to demonstrate the presence of p-glycoprotein in the 16 sensitive and five highly resistant glioblastomas. All 21 tumors identically expressed p-glycoprotein. These results show that untreated glioblastomas primarily express p-glycoprotein even if they are at least partially chemosensitive in vitro. Therefore, immunohistochemical demonstration of p-glycoprotein with the monoclonal antibody C 219 can not provide reliable information on short term resistance of the individual tumors to antineoplastic drugs. P-glycoprotein expression could, however, help to explain the disappointing overall long-term efficacy of chemotherapy by showing the existence of cell populations with early drug resistance in these tumors.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1998

Follow-up in carriers of the 'MELAS' mutation without strokes.

Eight carriers of the A3243G mutation of mitochondrial DNA without stroke-like episodes were monitored for up to 7 years in clinical and metabolic studies, by magnetic resonance imaging (MRI) and positron emission tomography (PET). None developed mitochondrial encephalopathy (MELAS), but 2 developed diabetes mellitus, 1 terminal kidney failure and 2 cardiomyopathy. One patient improved markedly under ubiquinone. Electroencephalography showed progressive slowing in 2 cases, but electrophysiological tests and MRI were otherwise noncontributary. PET showed widespread cortical and basal ganglion metabolic deficits in 6 cases. We conclude that internal medical complications are more common than MELAS in adult carriers of the mutation. PET findings, firstly reported in such patients, suggest that chronic subclinical encephalopathy is very frequent, and PET may play a role in monitoring in the future.

Adolescent↗
PubMed1997

Pleomorphic xanthoastrocytoma: report of six cases with special consideration of diagnostic and therapeutic pitfalls.

BACKGROUND: Pleomorphic xanthoastrocytoma (PXA) is a rare clinicopathologic entity that occurs typically in young patients. Improved neuroradiologic techniques, especially gadolinium-enhanced magnetic resonance imaging (MRI), reveal a characteristic tumor appearance. METHODS: We present six cases of PXA operated on with unusual clinical course, elucidating different clinical implications. RESULTS: Two patients showed subsequent progression into a malignant glioma, one case was a primary anaplastic PXA. The latter case had not previously been reported in the literature. Increased mitotic activity seems to indicate a worse clinical course; whereas focal infiltration of the brain does not necessarily lead to malignant transformation. CONCLUSIONS: Surgical removal is the treatment of choice. A consequent follow-up is mandatory in order to detect a potentially malignant recurrence as early as possible and to select patients who need additional therapy.

Adolescent↗
PubMed1997

Mitoxantrone-induced DNA strand breaks in cell-cultures of malignant human astrocytoma and glioblastoma tumors.

In this study mitoxantrone (Mtx) induced DNA strand breaks were measured with the alkaline elution technique in short term cell cultures derived from human gliomas. Glioblastomas or astrocytomas from 5 patients who underwent intracranial surgery were cultured and incubated i h with different concentrations of Mtx (0, 0.01, 0.1 and 1.0 microgram/ml). The alkaline elution method was modified to measure DNA lesions in human gliomas. Mtx induced DNA strand breaks in a dose dependent manner in all cell cultures tested. There was a linear increase of DNA strand break frequency induced by Mtx between 0.01-1.0 microgram/ml. concerning these in vitro data, Mtx might be potentially useful for the treatment of patients with malignant brain tumors.

Aged↗
PubMed1997

[Metaplastic ossification in an acoustic neurinoma].

We report the case of a 52-year-old woman with a cerebellopontine angle tumor, which appeared to have arisen from the 8th nerve. Microscopically the tumor was proved to be an acoustic neurinoma and showed unusual findings such as inclusions of mature bone and bone marrow. The histogenesis and diagnostic relevance of the very rare heterotopic osteogenesis in acoustic neurinomas is discussed.

Cerebellar Neoplasms↗
PubMed1996

VACTERL with the mitochondrial np 3243 point mutation.

The VACTERL association of vertebral, anal, cardiovascular, tracheo-esophageal, renal, and limb defects is one of the more common congenital disorders with limb deficiency arising during blastogenesis. The cause is probably heterogeneous; a molecular basis has not yet been defined. We report on a family in which a female infant with VACTERL was born in 1977 and died at age 1 month due to renal failure. Because her mother and sister later developed classical mitochondrial cytopathy associated with the A-G point mutation at nucleotide position (np) 3243 of mitochondrial (mt) DNA, we performed a molecular analysis of mt DNA in preserved kidney tissue from the VACTERL case. We discovered 100% mutant mt DNA in multicystic and 32% mutant mt DNA in normal kidney tissue. Mild deficiency of complex I respiratory chain enzyme activity was found in the mother's muscle biopsy. Other maternal relatives were healthy but had low levels of mutant mt DNA in blood. This is the first report to provide a precise molecular basis for a case of VACTERL. The differing tissue pathology depending on the percentage of mutant mt DNA suggests a causal connection between the mutation and symptoms. VACTERL, and this type of multicystic renal dysplasia, are new phenotypes for the np 3243 point mutation. The possibility of a mitochondrial disorder should be born in mind and also that VACTERL may occur as a first manifestation of a mutation that has been present for generations. This would have major implications for patient management and for genetic counselling regarding both the risk of recurrence and risk of other mitochondrial syndromes in affected families.

Abnormalities, Multiple↗
PubMed1996

Relation between cerebral oxygen delivery and neuronal cell damage in fetal sheep near term.

Asphyxia is one of the major causes for fetal brain damage. Although the quality of life of the so affected children is mostly very limited, the pathogenesis of hypoxic fetal brain damage is poorly understood. Particularly, there is a lack of studies, in which cerebral oxygen delivery is directly correlated to the extent of neuronal cell damage in the same brain specimens. Therefore, we measured cerebral oxygen delivery before (- 1 h), during (+3 min & +27 min) and after (+10 min, +4 h, +72 h) 30 min of ischaemia in 5 chronically catheterized normoxemic fetal sheep at 129 +/- 1 days gestation (term is at 147 days) using the microsphere method. In contrast to previous studies (Williams et al. 1990), we arrested carotid arterial blood flow above the lingual artery for 30 min during surgery. Seventy-two hours later the fetal brains were fixed in vivo under barbiturate anaesthesia of both the fetus and the ewe. After cerebral blood flow analysis neuronal cell damage was assessed with light microscopy in 43 specimens of the fetal brain after cresyl violet/fuchsin staining using a scoring system. After arrest of carotid arterial blood flow cerebral blood flow was reduced by 80%. Neuronal cell damage was focussed on the cerebral cortex. Almost no damage could be detected in deeper parts of the brain. In the cerebrum there was threshold oxygen delivery of 3 ml O2/100 g tissue/min, below which neuronal damage occurred. However, there was no correlation between cerebral oxygen delivery and neuronal cell damage in specimens of the cerebrum, in which oxygen delivery was less than 3 ml O2/100 g tissue/min, suggesting selective vulnerability. Therefore, in addition to the reduction in cerebral oxygen delivery, other variables, e.g. neurotransmitter release, receptor pattern or oxygen radicals, may be involved in the development of brain damage.

Analysis of Variance↗
PubMed1995

Clinical spectrum of the MELAS mutation in a large pedigree.

INTRODUCTION: MELAS is most often due to an mentally transmitted A-G transition mutation of mitochondrial DNA (mtDNA) at position 3243. In this study we report on the clinical spectrum associated with the mutation in the largest family reported so far. PATIENTS AND METHODS: In a family with three MELAS cases we identified 47 persons at risk for the mutation; sufficient data was available on 29. Mitochondrial disease was diagnosed in two of 9 deceased numbers (posthumous molecular analysis in one); 27 surviving family members underwent examination and 25 a molecular analysis of mt DNA from lymphoblasts. Then had a muscle biopsy and two were later autopsied. RESULTS: All 26 cases investigated by molecular analysis showed the mutation at position 3243. The 18 symptomatic patients without stroke-like episodes had sensorineural hearing loss in 15 cases, diabetes in 6, nephropathy in 7, mild myopathy in 4, cardiomyopathy in 2, cerebellar disease in 4 and mental retardation in 2 cases. Eight carriers were asymptomatic. Autopsy showed > 80% mutant mt DNA in all tissues except blood (20%) examined in a MELAS patients, but < 20 mutant mt DNA in all tissues except lever (40%) and kidney (70%) in a patient with hepatopathy, renal failure and diabetes. Histologic and biochemical studies of muscle biopsy were often non-informative. CONCLUSIONS: The mutation of mt DNA at position 3243 causes a multisystem disorder with a variable phenotype due to heteroplasmy. Most carriers are oligosymptomatic with hearing loss and a variety of neurological and internal medical symptoms. Diabetes, cardiomyopathy and renal disease, which is newly reported here for this mutation, are frequent. The blood test is a reliable screening tool in affected families, but is of prognostic value only combined with examination of other tissues.

Biopsy↗
PubMed1994

[Polyneuritis and myositis in Trypanosoma gambiense infection].

During a four-week trip to Nigeria a 54-year-old German developed a fever of 39 degrees C. Later on he had lymphadenopathy, pretibial oedema, dyspnoea and weight loss. After 16 weeks a wreath-like pale pink skin rash, increased pulse rate with pulse deficit and hepatosplenomegaly were noted. Abnormal laboratory findings were an increased blood sedimentation rate (95 mm), raised immunoglobulin M (483 mg/dl), haemoglobin of 12.0 g/dl, mean corpuscular volume of 76 fl and Borrelia IgM antibody titre of 1:512. The electrocardiogram was suggestive of myocarditis: the cardiac symptoms were controlled with digoxin and verapamil. The patient's general condition deteriorated while he was receiving antibiotic treatment with tetracycline and penicillin. Cerebrospinal fluid (CSF) showed an increased cell count (39/microliters) and albumin (0.98 g/dl). There was a mild, predominantly proximal, tetraplegia which--on the basis of electromyographic and biopsy findings--was thought to be due to polyneuritis and myositis. At this stage blood smear and CSF examination revealed Trypanosoma. He thereupon received suramin (1.0 g) and prednisolone (120 mg down to 40 mg) daily, to which melarsoprol was added after 6 days (0.5 ml up to 5.0 ml daily for 36 days). Almost all symptoms then regressed within 6 weeks.

Animals↗
PubMed1994

[Creutzfeldt-Jakob disease. Report of a case with an unusually long course and immunohistochemical localization of the prion protein and overview of current information].

The human spongiform encephalopathies are a group of neurodegenerative disorders of unknown origin. They comprise a group of horizontally transmissible and genetically determined diseases. We present here a case of Creutzfeldt-Jakob disease with an unusually long clinical course, in which the prion protein was localized immunohistochemically. The generally accepted hypothesis on the pathogenesis of these diseases is the so-called 'prion-hypothesis'. The implications of this hypothesis are discussed and a short review of the literature is given.

Atrophy↗