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Biomedical subjects

W Feiden

Publications and source records attributed to W Feiden.

At least 73 records · Page 4Linked to original sources
PubMed1995

[Computer-assisted speech recognition in diagnostic pathology. Development of the DragonDictate-30 K system for documentation].

The speech recognition system DragonDictate-30 K is the first commercially available product for personal computers (PC) that includes a thesaurus of 30,000 words which can replace the computer keyboard completely for report writing. The system is speaker-adaptative, i.e., it can learn the phonetic pattern of the pathologist's voice. We have developed a thesaurus with special terms from the field of diagnostic pathology to shorten the time-consuming training phase. DragonDictate is compatible with all text-oriented DOS computer software tools. The recommended minimal hardware configuration is a personal computer with a 80,486 processor with 16 MB on board and a 200 MB hard disk.

Computer Peripherals↗
PubMed1995

[Correlation of preoperative neuroradiologic with postoperative histologic diagnosis in pathological intracranial processes].

PURPOSE: To determine the accuracy of preoperative neuroradiological diagnosis of pathological intracranial processes in a prospective study. MATERIALS AND METHODS: A team of three neuroradiologists determined the diagnosis in CT, MR and angiography prior to stereotactic biopsy or operative resection (173 patients). Only one diagnosis was allowed, except in those cases with two equally probable diagnosis (24 patients). In 106 patients a resection of a brain tumor, in 67 cases a stereotactic biopsy was performed. According to the histological diagnosis the patients were subdivided into three groups: 1: complete agreement: the single diagnosis was correct. 2: conditional agreement: on of the 2 differential diagnosis was correct. 3: no agreement RESULTS: In 131 cases (76%) a complete agreement, in 24 cases (14%) a conditional agreement and in 18 patients (10%) no agreement were found. Assuming only stereotactic procedures the neuroradiological diagnosis was correct in 44 cases (66%) and incorrect in 10 cases (15%). In 13 patients (19%) one of the two differential diagnosis was correct. The specificity of the major tumors was calculated between 92% and 100%. The sensitivity for pituitary adenomas (n = 9) and neurinomas (n = 11) was 100%, the sensitivity for meningiomas (n = 32) was 94%. A sensitivity was calculated between 50% and 71% for astrocytomas (WHO I to WHO IV, n = 64) and metastases (n = 24). CONCLUSION: The accuracy was found to be higher than in the comparable retrospective studies.

Adolescent↗
PubMed1995

[Creutzfeldt-Jakob disease. What is the role of MR tomography?].

Creutzfeldt-Jakob disease (CJD) is a rare, but fatal and transmissible brain disease. The clinical diagnosis is based upon progressing dementia, myoclonic jerks and characteristic EEG changes, but it is difficult to diagnose and not only in the early phase of the disease. Cerebral biopsy is reserve for individual selected cases and contested because of the danger of contamination from instruments and potential transmission. We report three patients with histologically confirmed CJD and confirm that MRI is a valuable tool for the diagnosis of this disease.

Biopsy↗
PubMed1994

Monoclonal antibodies directed against the Epstein-Barr virus-encoded nuclear antigen 1 (EBNA1): immunohistologic detection of EBNA1 in the malignant cells of Hodgkin's disease.

Monoclonal antibodies directed against the Epstein-Barr virus nuclear protein 1 (EBNA1) were used to examine conventional paraffin sections from a series of EBV-associated lymphoproliferative disorders by immunohistochemistry. The presence of latent EBV infection in tumor cells was determined by in situ hybridization for the Epstein-Barr virus early RNAs (EBERs). Of those EBER-positive cases a total of 28 of 40 cases of Hodgkin's disease, 3 of 3 cases of Burkitt's lymphoma, and 8 of 8 cases of human immunodeficiency virus-associated cerebral B-cell lymphoma expressed detectable amounts of EBNA1. In the positive cases, expression was confined to the tumor cells. No reactivity was detected in EBV-negative cases of the above tumors or in 8 cases of EBV-negative cases of large cell anaplastic non-Hodgkin lymphoma. This report provides the first unequivocal evidence for the expression of the EBNA1 protein in the tumor cells of Hodgkin's disease and validates an important reagent with which to analyze the role of EBV in various virus-associated malignancies.

Amino Acid Sequence↗
PubMed1994

Application of minimal spanning trees in glioma grading--a CLIPPER program for the calculation and construction of minimal spanning trees.

We present a CLIPPER program for the calculation and graphical representation of minimal spanning trees (MST) which is available on request on diskette from the authors. The MST are a useful parameter for structural cluster detection. They can be applied to grading problems in tumour biology. We present and discuss the applicability of MST by an example from the field of astrocytoma grading.

Algorithms↗
PubMed1994

Detection of numerical chromosome aberrations in brain tumours by fluorescence in situ hybridization on smear preparations of small tumour biopsies.

We present a technique for the preparation and interphase cytogenetic analysis of native tumour cell nuclei from smear preparations of small biopsies of human brain tumours. The presence of tumour-specific numerical chromosome aberrations can be determined by fluorescence in situ hybridization (FISH) analysis using chromosome-specific repetitive DNA probes. The FISH analysis of smear preparations provides cytogenetic information about brain tumour samples, within 2 days, avoiding time-consuming and artefact-prone tumour cell culture.

Biopsy↗
PubMed1994

[Computer assisted grading of gliomas of the astrocytoma/glioblastoma groups].

For automated astrocytoma grading morphometric parameters are determined by means of an image analysis system and a special Ki-67(MIB1)/Feulgen-staining method allowing the quantification of the essential characteristics of malignant gliomas: growth pattern, cellularity, proliferation index and nucleus pleomorphism. Based upon a cluster analytical approach a grading scale resembling the WHO-scheme is established which is suitable for automatic glioma grading purposes (HOM-scale). For automatic glioma grading backpropagation neural networks are employed. The results are compared with those of a classical multivariate discriminant classificatory analysis. The presented approach can also be employed for automatic grading of other tumour entities.

Astrocytoma↗
PubMed1994

[Intracranial manifestations of Langerhans-cell histiocytosis. Nuclear magnetic resonance findings].

We report on 3 patients with intracranial manifestations of Langerhans cell histiocytosis (LH). The results are correlated with histological, clinical and radiological reports on some 70 patients described in the literature as suffering from intracranial LH. Two different morphological pictures can be differentiated. First, typical infiltrates can be seen by microscopy; these can be located in every part of the brain, but are seen mainly in the region of the hypothalamus. These infiltrations are shown as space-occupying lesions with Gd-DTPA enhancement. The other manifestation is a demyelinized lesion with a sparse infiltration of Langerhans cells. These lesions, which are located mainly in the region of the nucleus dentatus of the cerebellum and the brain stem, show increased signal intensity in the T2 sequence and no Gd-DTPA enhancement on MRI.

Adolescent↗
PubMed1994

[Familial association of hypothalamic hamartoma and polysyndactyly].

Hypothalamic hamartomas are congenital malformations. The association between hypothalamic hamartomas and other dysplasias, including polydactyly, is known to be a neonatal lethal syndrome. We report on two patients (mother and son) with asymptomatic large hypothalamic hamartomas and polysyndactyly. The relationship of the patients suggests an autosomal dominant transmission.

Adult↗
PubMed1993

Spectrum of complications during bacterial meningitis in adults. Results of a prospective clinical study.

OBJECTIVE: To determine systematically central nervous system and systemic complications during the acute phase of adult bacterial meningitis. DESIGN: Prospective clinical study. SETTING: University referral center, Department of Neurology. PATIENTS: A total of 86 consecutive patients between the ages of 15 and 87 years who had bacterial meningitis. MEASUREMENTS: Central nervous system complications, including brain swelling, hydrocephalus, brain abscess, subdural empyema, or subdural effusion (using computed tomography) and cerebrovascular involvement (using cerebral angiography), systemic complications, including septic shock, disseminated intravascular coagulation, adult respiratory distress syndrome, or septic or reactive arthritis, and typical complications arising during intensive care therapy. RESULTS: Of the 86 adult patients with bacterial meningitis, complications developed in 43 patients. The major central nervous system complications included angiographically documented cerebrovascular involvement (15.1% of the patients [13/86 patients]), brain swelling (14.0% [12/86]), hydrocephalus (11.6% [10/86]), and intracerebral hemorrhage (2.3% [2/86]), while septic shock (11.6% [10/86]), adult respiratory distress syndrome (3.5% [3/86]), and disseminated intravascular coagulation (8.1% [7/86]) dominated among the patients with systemic complications. Seven patients had cerebral herniation, three with a lethal course. The overall mortality was 18.6% [16/86] and was 10 of 30 (3.33%) in pneumococcal meningitis. CONCLUSIONS: Clinical and autopsy studies showed that the major determinants for the lethal outcome were primarily central nervous system complications in six patients, systemic complications in five, and a combination of both in another five. The identification of the various complications and their time of expected occurrence may help to develop additional treatment regimens in bacterial meningitis in adults.

Adolescent↗
PubMed1993

Combined Ki-67 and Feulgen stain for morphometric determination of the Ki-67 labelling index.

In this note we present a combined Ki-67 and Feulgen stain for morphometric determination of the Ki-67 labelling index. The immunohistochemical part of this double staining technique is based on the alkaline-phosphatase-anti-alkaline-phosphatase (APAAP) method, visualizing the enzyme activity by the nitro-blue-tetrazolium chloride (NBT)/bromo-chloro-3-indolyl-phosphate (BCIP) technique. The NBT/BCIP complex resists the hydrolytic activity of the Feulgen stain. The staining method presented allows semi-automatic determination of both the total nucleus-area as well as the Ki-67 positive nucleus-area using a morphometric computer system. The Ki-67 labelling index thus achieved is based on the relative nuclear area of Ki-67 positive nuclei and is clearly more precise and efficient than the counting method using an ocular grid.

Alkaline Phosphatase↗
PubMed1993

Recurrent t(12;19)(q13;q13.3) in intracranial and extracranial hemangiopericytoma.

We report on a recurrent intracranial hemangiopericytoma cytogenetically studied after short-term culture. The tumor had a uniform karyotype 47,XX,add(7)(q21),t(12;19)(q13;q13.3),del(13)(q14q22), +21. Remarkably, one case with an identical reciprocal (12;19) translocation has been previously reported as the sole cytogenetic change in a recurrent retroperitoneal hemangiopericytoma. This nonrandom structural change may characterize a subentity of hemangiopericytoma and might be of diagnostic value.

Aneuploidy↗
PubMed1993

The stereotactic biopsy diagnosis of focal intracerebral lesions in AIDS patients.

Focal intracerebral lesions were biopsied stereotactically in 23 adult HIV-infected patients, the main indication for which was the failure to respond to anti-toxoplasma treatment. A cerebral disease was the initial or main complaint in 19 of them. In 22 of 25 stereotactic approaches, a clear-cut morphological diagnosis could be established (9 primary brain lymphoma, 7 necrotizing toxoplasma encephalitis, 5 progressive multifocal leukoencephalopathy, 1 HIV encephalitis, 3 unspecific tissue changes). In 7 of 8 deceased patients, autopsy confirmed the bioptical diagnosis. The high diagnostic yield was related to the strategy of the stereotactic method and the sample size (3 to 4 consecutive samples along the stereotactic track including the marginal zones, 1 cm long tissue cylinders). Formalin fixation and paraffin embedding of the samples provide the possibility of serial sections and special stainings (immunohistochemistry, in-situ hybridization) and kill the HIV. Stereotactic brain biopsy is a highly accurate diagnostic tool to ascertain the nature of focal intracerebral lesions in selected AIDS patients.

AIDS Dementia Complex↗
PubMed1991

Accuracy of stereotactic brain tumor biopsy: comparison of the histologic findings in biopsy cylinders and resected tumor tissue.

Appropriate treatment for intracranial mass lesions depends upon accurate morphological diagnosis. In 47 of 360 patients the findings in stereotactically obtained tissue cylinders were compared with tumor resection (n = 38) or autopsy (n = 9) tissue material to define the accuracy of our stereotactic biopsy method. These biopsies were performed using the LEKSELL CT stereotactic frame and a spiral needle which procured about 10-mm-long tissue cylinders. Usually, three to four successive biopsy specimens were taken along the target trajectory placed through the whole lesion and its margins according to the CT imagings. Final morphological diagnosis was exclusively based on the histological findings of permanent paraffin sections. In 42 cases (89%), the histological results in biopsy and resection/autopsy tissue were identical, including mainly cases of low and high grade gliomas as well as some brain lymphomas, metastases, and cases of inflammatory brain lesions (aspergillosis, toxoplasmosis). In 3 patients with a diagnosis of brain lymphoma and low grade glioma on the basis of the surgical specimens, stereotactic biopsy revealed only unspecific reactive tissue changes. In two cases of the early part of the study, sampling errors occurred. This study provides evidence for the high diagnostic accuracy of the established stereotactic biopsy method which is characterized by representative tissue sampling and histological processing of the specimens.

Astrocytoma↗
PubMed1991

Amyloid angiopathy--a rare cause of intracerebral hemorrhage.

The cerebral amyloid angiopathy (CAA), morphologically characterized by amyloid deposition in the vessel walls which are altered to rigid tubes, is a chronic disease of the cortical and meningeal vessels and can cause intracerebral hemorrhages (1.5% of all intracerebral bleedings). We report the course of five surgically treated patients with lobar space-occupying intracerebral hemorrhages and CAA confirmed by histological examination. All patients were elderly (74-84 years), in good condition, and self-providing before the hemorrhage. There were no signs of dementia of the Alzheimer's type. In four cases, CT showed a hematoma in the parieto-occipital, and in one case in the temporo-parietal, region. After surgical evacuation, two patients recovered, one patient remained in bad condition, and two patients died from recurrent hemorrhage within two weeks. Spontaneous intracerebral hemorrhage of lobar localization in an elderly patient strongly suggests CAA. The prognosis seems to be poor in cases with recurrent hemorrhage, the other patients presented an uneventful course, comparable with patients operated on for intracerebral bleeding of other origin. Further investigations are necessary to elucidate the prognosis of this entity.

Aged↗