PubMed Health⌕ Search

Biomedical subjects

K Schwechheimer

Publications and source records attributed to K Schwechheimer.

At least 19 recordsLinked to original sources
PubMed2001

Spinal intramedullary metastases. Report of two cases and review of the literature.

Two cases of intramedullary metastasis were observed in our department within a short period of time that change the picture of uncommon locations of spinal metastases as described in literature. The patients presented primarily with rapidly progressing flaccid paraparesis of the lower extremities. Both additionally described diffusely located hypesthesia and pallhypesthesia of the limbs. One complained about sphincter disturbance. Both were treated by laminectomy and microsurgical extirpation of the tumor. In the first case reported here, an intramedullary metastasis of an epithelioid sarcoma in the conus medullaris region was ascertained which may be regarded as the first such reported case. In the second case report, histologic findings confirmed a thoracic intramedullary metastasis of a mastocarcinoma. At follow-up 6 and 8 months postoperatively, we observed full recovery of neurologic function in one patient and partial recovery in the other. Intramedullary metastases are extremely rare. Clinical presentation may show rapid onset and outcome is related to rapid resection and adjuvant therapy. In contrast to intracerebral metastases, this is a remarkable incidence of sarcomatous intramedullary metastatic disease.

Breast Neoplasms↗
PubMed2001

Cerebral aspergillosis: comparison of radiological and neuropathologic findings in patients with bone marrow transplantation.

Thirty-six lesions in six patients who died from cerebral Aspergillus infection after bone marrow transplantation (BMT) were studied with regard to signal intensity, contrast enhancement, size, and location. The diagnosis was confirmed in all cases by autopsy. Retrospective correlation of histopathological and radiological findings was possible for 14 lesions. Most of the lesions (22/36) had isointense to low signal intensity on T2-weighted images (T2WI). Histopathologically, hemorrhagic necrosis was determined in three of them. Areas of high signal intensity on T1-weighted images (T1WI) were related to gross hemorrhage. Two infarctions showed intravascular accumulation of fungal hyphae with secondary thrombosis of the vessel. The remaining 12 lesions had high signal intensity on T2WI and low on T1WI. Histopathologically, four were infectious and four were unspecific demyelinated lesions. In conclusion, cerebral aspergillosis typically presented with large lesions showing isointense to low signal intensity on T2WI that could have areas of high signal on T1WI. Contrast enhancement was only visible in 15 lesions, and the predominant locations were the subcortical white matter, the cerebellum, and the basal ganglia. Small lesions with high signal on T2WI and low signal on T1WI could not necessarily be related to Aspergillus infection.

Adolescent↗
PubMed2000

Expression of cancer testis genes in human brain tumors.

Cancer-testis (CT) genes are expressed in a variety of human cancers but not in normal tissues, except for testis tissue, and represent promising targets for immunotherapeutic and gene therapeutic approaches. Because little is known about their composite expression in human brain tumors, we investigated the expression of seven CT genes (MAGE-3, NY-ESO-1, HOM-MEL-40/SSX-2, SSX-1, SSX-4,HOM-TES-14/SCP-1, and HOM-TES-85) in 88 human brain tumor specimens. Meningiomas expressed only HOM-TES-14/SCP-1 (18% of meningiomas were HOM-TES-14/SCP-1 positive) and did not express any other CT genes. One ependymoma was negative for all CT genes tested. SSX-4 was the only CT gene expressed in oligodendrogliomas (2 of 5 cases), and it was also expressed in oligoastrocytomas (3 of 4 cases) and astrocytomas (10 of 37 cases). Astrocytomas were most frequently positive for HOM-TES-14/SCP-1 (40%) and SSX-4 (27%), followed by HOM-TES-85 (13%), SSX-2 (11%), and MAGE-3 (7%). Whereas MAGE-3 was detected only in grade IV astrocytomas, the expression of the other CT genes showed no clear correlation with histological grade. Of 39 astrocytomas, 60% expressed at least one CT gene, 21% expressed two CT genes, and 8% coexpressed three CT genes of the seven CT genes investigated. We conclude that a majority of oligoastrocytomas and astrocytomas might be amenable to specific immunotherapeutic interventions. However, the identification of additional tu-mor-specific antigens with a frequent expression in gliomas is warranted to allow for the development of widely applicable polyvalent glioma vaccines.

Antigens, Neoplasm↗
PubMed1999

Reverse transcriptase polymerase chain reaction as a reliable method to detect epidermal growth factor receptor exon 2-7 gene deletion in human glioblastomas.

Epidermal growth factor receptor (EGFR) gene amplification has been reported to occur in diverse carcinoma types such as lung, ovarian, and breast carcinomas and in glioblastomas. A 801-bp in-frame deletion close to the aminoterminus of the receptor protein has been found to occur more or less frequently within at least three of these tumor entities. We studied EGFR gene alterations using the polymerase chain reaction and EGFR gene expression of 65 astrocytic tumors (51 glioblastomas World Health Organization [WHO] IV, five anaplastic astrocytomas WHO III, and nine astrocytomas WHO II). EGFR gene amplification, as determined by Southern blotting using a full-length cDNA probe, was observed in 22 of 51 glioblastomas (43%) but in none of the grade II astrocytomas. Two of five anaplastic astrocytomas at WHO III showed a considerable degree of EGFR amplification but, according to the neuroradiological data, these two tumors had to be considered as glioblastomas. The most frequently found genetic alteration was the 801-bp deletion near the receptor aminoterminus comprising a complete loss of exon 2 to exon 7 (del2-7). We showed that RT-PCR is superior to Southern blot analysis in detection of this type of deletion and can be assigned to 9 of 38 (24%) glioblastomas examined. Expression of a EGF receptor protein was enhanced in most of the tumors with gene amplification. However, 5 of 18 tumors that express a receptor protein in the absence of EGFR gene amplification also showed elevated levels of EGFR gene expression. In addition to the full-length receptor protein, a signal in the 140-kDa range was observed in 17 of 35 glioblastomas (49%). This fragment may correspond to the truncated de12-7 receptor protein or might be due to proteolysis of the full-length receptor protein.

Blotting, Southern↗
PubMed1999

Lhermitte-Duclos disease as a component of Cowden's syndrome. Case report and review of the literature.

In recent years, 16 cases involving the association between Lhermitte-Duclos disease (LDD), which is a hamartomatous overgrowth of cerebellar tissue, and Cowden's syndrome (CS), an autosomal-dominant condition characterized by multiple hamartomas and neoplasias, have been reported. LDD may be one of the manifestations of CS. Recently, mutations of the PTEN/MMAC 1 gene, a tumor suppressor gene, have been found in families with CS, including four patients in whom LDD was diagnosed. The authors present a case of LDD in a 53-year-old woman who also had the typical mucocutaneous lesions found in CS, as well as goiter and intestinal polyposis. In this case, CS had never been suspected until the diagnosis of LDD was made. The mutation detected in the PTEN/MMAC 1 gene as well as neuropathological results are described.

Cerebellar Neoplasms↗
PubMed1999

Genetic profile of the giant cell glioblastoma.

Giant cell glioblastoma is a rare glioblastoma variant characterized by the presence of large, bizarre, multinucleated giant cells. This glioblastoma subtype develops clinically de novo after a short clinical history and contains a high frequency of p53 mutations. In this study, we screened a series of 18 giant cell glioblastomas for additional genetic alterations. PCR-SSCP followed by DNA sequencing revealed PTEN mutations in 5 of 15 tumors (33%). Of these, two mutations were located in exon 5, two mutations in exon 6, and one mutation each in exons 1 and 9. Four mutations were point mutations and two mutations were deletions. One neoplasm contained two PTEN mutations (exons 5 and 6). None of the giant cell glioblastomas showed a homozygous deletion of PTEN orp16, or amplification of MDM2. Immunohistochemically, MDM2 overexpression was either not observed or detected in only a minor fraction of tumor cells. Differential PCR revealed EGFR amplification in only one of 17 tumors (6%). These results indicate that giant cell glioblastomas occupy a hybrid position, sharing with primary (de novo) glioblastomas a short clinical history, the absence of a less malignant precursor lesion and a 30% frequency of PTEN mutations. With secondary glioblastomas that develop through progression from low-grade astrocytomas, they have in common a younger patient age at manifestation and a high frequency (>70%) of p53 mutations.

Adult↗
PubMed1998

E-Cadherin in human brain tumours: loss of immunoreactivity in malignant meningiomas.

Cadherins are a family of glycoproteins that are associated with cell adhesion mechanisms. They are divided into subclasses. The E- and P-cadherins are regarded as the epithelial subtype. Their expression has been demonstrated in many different carcinoma types. Using immunomorphological techniques, we studied the expression of E-cadherin in a series of 145 human brain tumours with the monoclonal antibody 5H9. Western blot analysis was used to confirm the immunohistochemical data. The tumour types represented were astrocytoma WHO I (n = 7), astrocytoma WHO II (n = 6), astrocytoma WHO III (n = 14), glioblastoma WHO IV (n = 8), oligodendroglioma WHO II (n = 5), ependymoma WHO II (n = 5), choroid plexus papilloma WHO I (n = 5), pineoblastoma WHO IV (n = 5), medulloblastoma WHO IV (n = 5), neurinoma WHO I (n = 5), meningioma WHO I and WHO III (n = 75) and pituitary adenoma WHO I (n = 5). Only choroid plexus papillomas (5/5) and meningiomas showed E-cadherin expression. In benign meningiomas (n = 45; 100%), positive E-cadherin immunoreactivity was found regardless of the histomorphological subtype. E-Cadherin was also expressed in 21 WHO I meningiomas (100%) invading dura, bone, brain, and muscle. In contrast, E-cadherin was absent from the majority of morphologically malignant meningiomas (6/9, 66.6%). In addition, in recurrent meningiomas (n = 9), E-cadherin expression in the recurrent tumours was identical to that in the primary neoplasm except in cases with malignant progression, where the malignant recurrent tumour was E-cadherin negative. In 2 cases of metastasizing meningiomas, no E-cadherin immunoreactivity was found in the primary tumours or their metastases.

Adult↗
PubMed1998

Myopathy in two siblings with nephropathic cystinosis.

Nephropathic cystinosis is a hereditary disorder characterized by a specific defect in the transport of cystine across the lysosomal membrane, leading to an accumulation of protein-free cystine in tissues, including conjunctiva, liver, bone marrow and kidney. Renal transplantation is necessary because of renal failure. With improved life-expectancy, neurological complications have been reported, including cases of distal myopathy diagnosed ante- and post-mortem. We report on two further rare cases of two siblings suffering from cystinosis who developed a predominantly distal myopathy, proven electrophysiologically and on biopsy during life. The reported clinical picture of a distal atrophy resembling a neurogenic disease, confirms a picture apparently typical in cystinosis. Possible effects of cysteamine therapy on the course of the myopathy are discussed. Copyright 1998 Lippincott Williams & Wilkins

Journal Article↗
PubMed1997

A patient with interstitial deletion of the short arm of chromosome 3 (pter-->p21.2::p12-->qter) and a CHARGE-like phenotype.

We report on a 4-month-old boy with a de novo interstitial deletion of the short arm of chromosome 3 (pter-->p21.2::p12-->qter) and clinical findings typical of proximal 3p deletion together with coloboma of iris, heart defect, choanal atresia, retardation of growth and development, genital hypoplasia, and ear anomalies. Family history was unremarkable and parental chromosomes were normal. The clinical manifestations of the patient are compared with those of 10 patients previously described with a proximal 3p deletion. The additional CHARGE-like phenotype is discussed.

Abnormalities, Multiple↗
PubMed1996

Expression of ciliary neurotrophic factor is maintained in spinal motor neurons of amyotrophic lateral sclerosis.

Ciliary neurotrophic factor (CNTF) was originally identified as a potent survival factor for a variety of neuronal cell types in vitro and in vivo and in particular in spinal motor neurons of embryonic chick and rat. Using a monoclonal antibody against CNTF (clone 4-68) we analysed the expression of CNTF in paraffin sections of seven human brains and spinal cords immunocytochemically using the ABC method and compared these results with sections of the spinal cords of patients suffering from amyotrophic lateral sclerosis (ALS). In normal human tissue of the central nervous system CNTF immunoreactivity was found in most of the motor neurons of the motor cortex and ventral horn, neurons of the nucleus oculomotorius, intermediolateralis, thoracicus, ependymal cells as well as in smooth muscle cells and endothelial cells of small arteries. A reduced number of astrocytes showed a positive immunocytochemical reaction. In peripheral nerves and nerve roots of the spinal cord we also found a positive staining of Schwann cells and some axons. These immunoreactions could be confirmed by Western blot analyses. Next we analysed postmortem paraffin sections of the spinal cord of seven patients suffering from ALS (age range 30-76 years, female/male = 4:3). We found CNTF immunoreactivity in most of the motor neurons of the ventral horn in 5 cases. In two cases the number of positively stained motor neurons was less. From these results we conclude that CNTF is expressed in a high number of upper and lower motor neurons in the human CNS and that its expression is maintained in ALS patients.

Aged↗
PubMed1996

Lipomatous medulloblastoma in adults. A distinct clinicopathological entity.

We report on three patients who presented with a cerebellar medulloblastoma at age 48, 53, and 59 years. Histopathology showed typical features of medulloblastoma, in one case with marked neuronal differentiation. In addition, all neoplasms contained focal accumulations of mature fat cells. Immunoreactivity of adipocytes for S-100 protein, neuron-specific enolase, synaptophysin, microtubule-associated protein-2, and glial fibrillary acidic protein and the lack of immunoreactivity to type IV collagen suggest lipomatous differentiation of neoplastic primitive neuroectodermal cells rather than an admixture of mesenchymal elements. Mitotic activity was low and the growth faction, as determined by the MIB-1 labeling index, was less than 5%. All patients are alive with a recurrence-free interval ranging from 3.5 to 12 years. These three patients and five similar previously reported cases all fit into the concept of the lipomatous medulloblastoma as a new clinicopathological entity characterized by (a) typical features of a cerebellar medulloblastoma with advanced neuronal differentiation, (b) areas of lipomatous differentiation, (c) low proliferative potential, (d) manifestation in adults (mean age, 50 years), and (e) apparent favorable clinical prognosis.

Adipose Tissue↗
PubMed1996

Primary spinal epidural manifestation of malignant lymphoma.

The clinical, histological and immunomorphological data in 19 cases of primary spinal epidural manifestation of malignant lymphomas collected between 1974 and 1994 are reported. The age of the patients varied between 11 and 87 years with a mean age of 56.3 years. There was a slight male predominance (11:8). In most cases, the onset of the clinical symptoms was rapid. The preferential tumour localization was the epidural space related to the thoracal vertebral bone. In each case, decompressive laminectomy was performed. The tumours were histologically and immunomorphologically classified as B-cell lymphomas (14 of 19), T-cell lymphomas (3 of 19) and anaplastic plasmacytoma (1 of 19). Except for one case, post-operative staging did not reveal anything other than epidural manifestation of the malignant lymphoma. The vertebral bone, however, was involved in seven cases. Irradiation alone, or in combination with chemotherapy, was performed as additional therapy. The post-operative survival time was variable.

Adolescent↗
PubMed1995

EGFR gene amplification--rearrangement in human glioblastomas.

Immunostaining using an affinity-purified rabbit polyclonal antibody against the extracellular domain of the epidermal-growth-factor receptor (EGFR) showed over-expression occurring in a fraction of tumor cells in 17 out of 18 human glioblastomas and in a majority of cells in 7 of the 18. Southern-blotting technique using a full-length EGFR cDNA probe showed a variable degree of amplification in 10 of the 17 glioblastomas, which was associated with EGFR over-expression in each case. In 2 of the glioblastomas with EGFR gene amplification, a rearrangement of the gene affecting the extracellular domain of the receptor was identified and DNA sequence analyses revealed an identical deletion-rearrangement of 801 base pairs between exons 2 to 7, resulting in an in-frame fusion of exons 1 and 8.

Base Sequence↗
PubMed1995

HMB45: a specific marker for melanoma metastases in the central nervous system?

The monoclonal antibody HMB45 is used to detect an epitope specific for melanocytes, malignant melanomas and melanoma metastases. Using the PAP method, we observed consistent expression of HMB45 in 19 metastases of melanotic and amelanotic malignant melanomas of the central nervous system, while metastases of 32 adenocarcinomas, 10 squamous cell and 8 small cell carcinomas were negative except for 2 cases of breast cancer. Differential diagnosis between cancer and melanoma metastases can be made using cytokeratins as an additional immunocytochemical marker protein. Ten meningeomas and 5 pineocytomas were also negative. Even though it is not absolutely specific, we consider the HMB45 immunoreaction diagnostic for a metastasis of a malignant melanoma if the tumour is cytokeratin negative and HMB45 positive in a large number of tumour cells.

Antigens, Neoplasm↗
PubMed1995

Schwann cell tumors express characteristic patterns of CD44 splice variants.

Members of the CD44 family of cell surface hyaluronate-binding proteins have been implicated in cell migration, cell-matrix interactions and tumor progression. To determine whether these proteins might play a role in the normal functions of Schwann cells and in their tumorigenesis, we examined the patterns of CD44 expression in Schwann cells from rat peripheral nerve, rat Schwann cell tumor lines, and human schwannomas. Normal rat spinal nerves and primary Schwann cell cultures expressed standard CD44 (CD44s) but not alternatively spliced variant isoforms. In contrast, rat Schwann cell tumor lines expressed both CD44s and a number of variants, including proteins containing sequences encoded by exon v6. Furthermore, we found that these cell lines bind hyaluronate, and that their cell surface hyaluronate binding correlates with CD44 expression. All of the human schwannomas also expressed CD44 variants, especially epitopes encoded by exon v5, the border between v7 and v8, and v9-10. These data indicate that Schwann cells normally express CD44s, that Schwann cell tumors express both CD44s and particular variants of CD44, and that CD44s and possibly variants of CD44 are involved in hyaluronate recognition by Schwann cell tumors.

Alternative Splicing↗
PubMed1995

On the role of human herpesvirus 6 in viral latency in nervous tissue and in cerebral lymphoma.

Latent infections by human herpesvirus 6 (HHV6) in nervous tissue and its role in human disease are poorly understood. For the present study, an improved PCR method has been applied to brain tissue samples from 5 different brain regions from 20 forensic post-mortem cases without neurologic involvement. Spleen tissue from these cases as well as 5 cerebral lymphoma tissue samples were also examined. HHV6 DNA was detected in 3 of 20 brains. The viral sequences could be amplified from cortical brain tissue from these 3 cases. In one of these cases, HHV6 DNA was detectable in two separate tissue samples. PCR was negative in brain lymphoma and spleen tissue. These findings point toward HHV6 latency in brain tissue and might thus support the reported glial tropism of this virus. No role could be found for HHV6 in the pathogenesis of cerebral lymphoma.

Adult↗
PubMed1995

Neuropathologic findings after organ transplantation. An autopsy study.

Since 1972 organ transplantations of kidney, bone marrow, liver, heart and lung have been performed at the University Hospital of Essen, Germany. Out of 2535 transplantations until September 1993, autopsies were performed in 157 patients In 25 patients (15.9%) neuropathologic findings (n = 26) were found. In 97 autopsies after bone marrow transplantation, 9 patients (9.3%) exhibited a severe neuropathologic alteration. In six patients (6/9; 66.6%), necrotisizing toxoplasmose encephalitis was found. Other cases showed a septic-metastatic mycotic encephalitis with crypto-coccus neoformans and candida albicans (n = 2) and leucemia infiltrates (n = 1). Massive cerebral hemorrhage was the most frequent neuropathologic finding after liver (4/8) and kidney transplantation (3/6). In addition liver-transplanted patients exhibited septic-metastatic encephalitis (3/8) and embolic brain infarct (1/8) as well as cerebral metastases (2/6) and primary malignant cerebral lymphoma in kidney transplantation (1/6). CNS findings in five autopsies after heart-lung-transplantation were diverse. They comprised intracerebral hemorrhage, intravasal lymphoma and septic-metastatic encephalitis, respectively. In summary, neuropathologic autopsy findings after organ transplantation are diverse and preferentially comprise infections, cerebral hemorrhages, and malignant lymphomas. After bone marrow transplantation, the most frequent neuropathologic autopsy finding was toxoplasmose encephalitis and massive cerebral hemorrhages after liver and kidney transplantations.

Adolescent↗