Homozygous TBC1 domain-containing kinase (TBCK) mutation causes a novel lysosomal storage disease - a new type of neuronal ceroid lipofuscinosis (CLN15)?

Homozygous mutation of TBC1 domain-containing kinase (TBCK) is the cause of a very recently defined severe childhood disorder, which is characterized by severe hypotonia, global developmental delay, intellectual disability, epilepsy, characteristic facies and premature death. The link between TBCK loss of function and symptoms in patients with TBCK deficiency disorder (TBCK-DD) remains elusive. Here we demonstrate for the first time the histopathological characteristics of TBCK deficiency consisting of 1) a widespread and massive accumulation of lipofuscin storage material in neurons of the central nervous system without notable neuronal degeneration, 2) storage deposits in few astrocytes, 3) carbohydrate-rich deposits in brain, spleen and liver and 4) vacuolated lymphocytes. Biochemical examinations ruled out more than 20 known lysosomal storage diseases. These investigations strikingly uncover TBCK-DD as a novel type of lysosomal storage disease which is characterized by different storage products rather than one specific type of accumulated material. Due to the clear predominance of intraneuronal lipofuscin storage material and the characteristic clinical presentation we propose to classify this disease as a new subtype of neuronal ceroid lipofuscinosis (CLN15). Our results and previous reports suggest an autophagosomal-lysosomal dysfunction caused by enhanced mTORC1-mediated autophagosome formation and reduced Rab-mediated autophagosome-lysosome fusion, thus disclosing potential novel targets for therapeutic approaches in TBCK-DD.

The Possible Role of Mast Cells and VEGF in Peritumoural Oedema of Secretory Meningioma.

Objective: Secretory meningiomas constitute a relatively rare subtype of meningiomas and present often with massive peritumoural oedema. From our previous report, a high number of mast cells were demonstrable in this subtype of meningiomas. The present study aimed to obtain more information about mast cell derived progangiogenic factors and mediators as well as VEGF receptors in secretory meningioma. Additionally, the correlation of histological factors such as the presence of mast cells and the radiological evidence of surrounding tumour oedema was analysed. Material and Method: Sixteen cases of secretory meningioma were examined. Relevant clinical information was obtained from the patient files. The peritumoural oedema was determined either by CT or MRI scans and graded as mild, moderate and severe. Immunohistochemical studies of histamine, substance P, serotonin, VEGF and VEGF receptors were performed. A double-blind quantitative evaluation of mast cells staining positively for VEGF in a comparison with total mast cells in secretory meningiomas was made by two histopathologists. Results: There was no immunoreactivity against histamine or substance P within the tumour tissue or in mast cells. Fine granules of serotonin were demonstrated within the mast cells and a coarse granular expression of VEGF was found within the mast cells. Our preliminary data demonstrated that tumours with moderate to severe degree of peritumoural oedema usually contained more than 50% of VEGF-staining positive mast cells. Conclusion: Secretory meningiomas are characterized by a significantly increased number of mast cells. VEGF and serotonin might be involved in the pathophysiological process of this vasogenic brain oedema. The preliminary data demonstrated the potential relation between the radiological evidence of increasing oedema and the high numbers of mast cell staining positively for VEGF.

[Frontotemporal dementia]. / Frontotemporale Demenz (Pick-Komplex). Kurzübersicht anhand eines Fallbeispiels.

BACKGROUND: Among the primary degenerative dementias, frontotemporal dementia (FTD, Pick's disease) is very important along with Alzheimer's disease. The estimated prevalence is 15:100,000 in the 45- to 64-year-old population; thus, it appears that the FTD as a cause for so-called presenile dementia is nearly as common as Alzheimer's disease. CASE REPORT: The case of a 52-year-old woman is described that presented with slowly progressive lack of concentration and disturbance of memory. Furthermore, the immediate family had noticed a change in her premorbid personality. Due to additional depressive symptoms, she was misdiagnosed with depressive pseudodementia first. CONCLUSION: Since the clinical presentation of FTD is variable and the correct classification has been uncertain for a long time, clinical diagnosis can be very difficult, so that the disease is often detected too late or remains completely misdiagnosed. On this basis, pathology, clinical aspects, diagnosis, and therapeutic options of FTD will be demonstrated according to current standards of knowledge.

Failure to improve the effect of thrombolysis by memantine in a rat embolic stroke model.

OBJECTIVES: Partial and delayed recanalization is a regular finding after thrombolysis in stroke patients who may benefit from additional therapy with neuroprotectants. To translate this scenario into an experiment, memantine was combined with thrombolysis in an embolic stroke model and tissue outcome was assessed in terms of complete and incomplete damage. METHODS: Tissue plasminogen activator (tPA, 5 mg/kg, b.w.) was administered 1.5 or 3.5 hours after embolic middle cerebral artery (MCA) occlusion in rats. In both groups, rats were assigned to additional therapy with memantine (10 mg/kg, i.p.) or saline injection. Ischemia and eventual reperfusion were continuously monitored by laser-Doppler flowmetry. Reperfusion was defined as a lasting increase in post-thrombolytic cerebral blood flow to >60% of baseline (complete) or to a lesser degree (partial). Experiments were terminated 6 hours post-occlusion to obtain quantitative histopathology. RESULTS: tPA induced complete or partial recanalization in 54% of treated animals. Successful reperfusion reduced total ischemic lesion volume by 42% compared with non-reperfused animals (p<0.05), but increased significantly the percentage of scattered neuronal injury from 25.6 (non-reperfusion) to 36.3% (reperfusion, p<0.05). Memantine did not improve the effect of tPA-induced recanalization on infarct morphology whether applied at 1.5 or 3.5 hours post-occlusion. DISCUSSION: We conclude from our experiments that add-on therapy with memantine did not alter the effect of thrombolysis in an embolic stroke model. Recanalization appears to be a prerequisite to confer neuroprotective effects.

Clinicopathologic features of aggressive meningioma emphasizing the role of radiotherapy in treatment.

BACKGROUND AND PURPOSE: Although meningiomas are typically benign, they occasionally behave in an aggressive fashion and carry a less favorable prognosis. The aim of this study was to review the clinical, radiologic and histopathologic features of these aggressive variants as well as the outcome after multimodality therapy. PATIENTS AND METHODS: 16 patients with atypical meningiomas (n = 11) and anaplastic meningiomas (n = 5) were treated in the Departments of Neurosurgery and Radiation Oncology at the University Hospital of Philipps University Marburg, Germany, between 1997 and 2003. Tumor grading was based on new WHO criteria. There were eleven men and five women with a mean age of 54 years. The median follow-up period was 34 months. RESULTS: A total of 24 surgical procedures were performed for these 16 patients. Only seven patients underwent postoperative fractionated stereotactic radiotherapy. Patients with atypical meningioma received radiotherapy only for the recurrent disease. Six patients (37.5%) experienced tumor recurrence after a mean period of 27.2 months in spite of gross total resection. Radiographic findings suggestive of aggressiveness were observed mostly with WHO grade III meningiomas. By comparing the proliferation rate in four cases with atypical meningioma operated twice, the recurrent tumor had a higher proliferation rate than the first tumor in three cases. A special proliferation pattern was noticed in MIB-1 with anaplastic meningiomas. The mean overall survival period was 66.5 months. There was no mortality among patients with atypical meningioma, while four out of five patients with anaplastic meningioma died during follow-up. CONCLUSION: Considering the higher rate of recurrence in aggressive meningiomas even after radical surgical excision and the possibility that the recurrent tumor is more aggressive than the original one, surgery should be combined with postoperative fractionated radiotherapy to improve local tumor control. The peculiar focal expression patterns of anaplastic meningioma in MIB-1 might be a marker of such malignant development.

The cardiac isoform of alpha-actin in regenerating and atrophic skeletal muscle, myopathies and rhabdomyomatous tumors: an immunohistochemical study using monoclonal antibodies.

The two sarcomeric isoforms of actins, cardiac and skeletal muscle alpha-actin, are highly homologous so that their immunohistochemical distinction is extremely difficult. Taking advantage of monoclonal antibodies distinguishing the two conservative amino acid exchanges near the aminoterminus, we have performed an extended immunohistochemical analysis of the cardiac alpha-actin (CAA) isoform in normal, regenerating, diseased and neoplastic human muscle tissues. Intense and uniform CAA staining is seen in fetal and adult myocardium and in fetal skeletal muscle while adult skeletal muscle is essentially negative, except for muscle spindle myocytes and a few scattered muscle fibres with overall reduced diameter. By contrast, CAA synthesis is markedly induced in regenerating skeletal muscle cells, in Duchenne muscular dystrophy and upon degenerative atrophy. CAA has also been detected in certain vascular and visceral smooth muscle cells. Among tumors, CAA has consistently been seen in rhabdomyosarcomas and rhabdomyomatous cells of nephroblastomas, whereas, smooth muscle tumors have shown only occasional staining. While the synthesis of this actin isoform is less restricted than previously thought, monoclonal antibodies against CAA provide a well-defined, reliable and sensitive diagnostic tool for the definition and detection of aberrant differentiation in diseased skeletal muscle and of striated muscle differentiation in rhabdomyosarcomas.

Biological activity of paediatric cerebral cavernomas: an immunohistochemical study of 28 patients.

OBJECTIVE: According to the hypothesis that paediatric cerebral cavernomas may have different biological activity compared to adult cavernomas, immunohistochemical analysis was used to elucidate the biological nature of paediatric cavernomas. PATIENTS AND METHODS: We examined the histological features and the proliferative and angiogenic capacity of the tissue specimens acquired from 28 paediatric patients. Normal paediatric brain tissues obtained from paediatric autopsy cases were used as a control group. The proliferative activity of the endothelium and the neoangiogenetic capacity were investigated by immunohistochemistry for proliferating cell nuclear antigen (PCNA), Ki-67 epitope (MIB-1), Flk-1 receptor, vascular endothelial growth factor (VEGF), hypoxia-inducible factor (HIF)-1 alpha, and endoglin antibody, respectively. Afterwards, the results of the paediatric lesions were analysed and compared with the correspondent values of previously reported immunohistochemical analysis in adult cavernomas. RESULTS: Positive immunostaining of VEGF was detected significantly less in paediatric cavernomas compared to adult cases (p<0.05). In contrast, endoglin, a protein that is upregulated during an increased vascular shear stress, was expressed more often in paediatric cavernomas (p<0.05). Neither the expression of the PCNA nor the expression of the HIF-1alpha was found significantly different between paediatric and adult cavernomas. However, the positive immunoreaction for MIB-1 occurred more often in the paediatric cases (p<0.05). CONCLUSIONS: The immunohistochemical study indicates that paediatric cavernomas are dynamic lesions. The VEGF/Flk-1 associated neoangiogenesis may play a minor role for the biology of paediatric cavernomas, while endoglin seems to act more prominently than previously thought, particularly for the biology of paediatric cavernomas.

Secretory meningioma: immunohistochemical findings and evaluation of mast cell infiltration.

Secretory meningiomas constitute a relatively rare subtype of meningiomas, accounting for only 1.1% at our institution, with a 6:1 predominance of female patients. This study aimed to obtain more information about the immunohistochemical characteristics of this histological entity, and to analyse the effects of histological factors such as the presence of mast cells on the radiological evidence of surrounding tumour oedema that frequently occurred in this subtype of meningioma. Fourteen cases of secretory meningioma were examined. Relevant clinical information was obtained from the patient files. Peritumoural oedema was determined either by CT or MRI scans and graded as small, moderate and severe. In order to perform the quantitative evaluation of mast cells in secretory meningiomas in a comparison with other meningiomas, 14 non-secretory meningiomas were randomly selected and used as a control group. The immunohistochemical staining of carcinoembryonic antigen was positive within the secretory droplets and the cells surrounding them in all cases. Ki 67 (MIB 1) proliferative index mean values were 2.4%, indicating low expression in all secretory meningiomas. Moreover, from our statistical analysis, there is no clear-cut pattern of various types of cytokeratins emerging in secretory meningiomas. The secretory meningiomas were characterized by a significantly increased number of mast cells as compared with non-secretory meningiomas of different grades. As the present clinical findings and laboratory results could not confirm a correlation between mast cell density and radiological evidence of oedema, further studies of mediators are warranted.

Enlarged perivascular spaces mimicking multicystic brain tumors. Report of two cases and review of the literature.

The authors present two cases in which enlarged Virchow-Robin spaces were located in the basal ganglia and the thalamomesencephalic region. The incidence of such huge cystic lesions is extremely rare. The expanding nature of these lesions, demonstrated by the patients' progressive symptoms due to compression of the adjacent brain parenchyma and obstructive hydrocephalus, mimicked that of brain tumors. The two patients were successfully treated by neuroendoscopic cystocisternostomy or ventriculocystostomy. To the authors' knowledge there have been only two published reports on expanding Virchow-Robin spaces that produced a compressive effect or consequent hydrocephalus and were directly fenestrated using neuroendoscopic techniques. Neuroendoscopy appears to offer an effective surgical option in the treatment of symptomatic Virchow-Robin spaces.

Expression of p53 and p21 in primary glioblastomas.

BACKGROUND AND PURPOSE: Primary glioblastomas (GBMs) are highly radioresistant, and in contrast to secondary GBMs, they bear wild-type (wt) p53 protein, which is stabilized in a proportion of these tumors. Therefore, it was investigated in vivo whether p53 expression has prognostic value in patients undergoing radiochemotherapy. Additionally, the authors tried to identify, in vitro, subgroups of primary GBM with different susceptibilities to irradiation, on the basis of their p53 and p21 responses to ionizing radiation. MATERIAL AND METHODS: Tumor tissue samples from 31 patients suffering from primary GBM undergoing a combined radiochemotherapy with topotecan were investigated. The percentage of cells expressing p53 protein was determined immunohistochemically. Additionally, primary cultures from eleven primary GBMs were established and investigated. p53 and p21 expressions were evaluated before irradiation with 10 Gy and at 2 and 8 h after irradiation. p53 protein expression was measured by Western analysis and p21 mRNA expression by reverse transcription-polymerase chain reaction (RT-PCR). RESULTS: The percentage of p53-positive cells within the tumor specimens obtained from the 31 patients ranged from 0% to 28%, the median value being 4.3%. No significant correlation with disease-free survival or overall survival was found. In vitro, p53 protein was detected in seven of eleven cultures from primary GBM. After irradiation a decrease in p53 protein expression was seen in six of the seven p53-positive cultures. Half of the cultures (two of four) without basal p53 expression showed an increase in p53 expression after irradiation. Basal overexpression of p21 was detected in six of the eleven cultures; in four out of six irradiation led to a decrease in p21 expression. In all cell lines (five of eleven) initially showing absent p21 expression, irradiation induced p21 expression. Despite these responses, G1 arrest was not detectable in any of the GBM cultures. CONCLUSION: p53 protein expression in vivo does not correlate with the outcome of patients with primary GBM. Therefore, p53 protein content per se does not appear to be a helpful prognostic factor for prognosis-adapted therapy in primary GBM. By contrast, primary GBM cells in vitro show different and independent responses in their p53 and p21 pathways to ionizing radiation. The failure of G1 arrest seems to be due to a functional defect in the p53 pathway, either because p21 was not induced or because of an unidentified defect downstream from p21.

Molecular characterization of desmosomes in meningiomas and arachnoidal tissue.

Intercellular junctions morphologically identical to epithelial desmosomes are known structures in meningiomas and arachnoidal tissue. Desmoplakin as one of the desmosomal plaque components has proven to be a reliable marker for diagnosis of meningeal tumors. Here we demonstrate by immunofluorescence microscopy, immunoblot and reverse transcription-PCR reactions that cells of arachnoidal tissue, of diverse meningioma subtypes and of a meningioma-derived cell line contain the full complement of the typical desmosomal proteins desmoplakin (DP), plakophilin 2 (PP2), desmocollin 2 (Dsc2) and desmoglein 2 (Dsg2). Consequently, all these molecules are suitable for diagnostic applications of meningioma tumors. In addition to these constitutive desmosomal components, representative for single-layered (simple) epithelia, the dural border cells of the arachnoid and about 60% of the meningiomas tested were positive for desmocollin 3 (Dsc3), a protein in epithelia taken as an indicator for differentiation.

Isolated paramedullary hemangioblastoma originating from the first cervical nerve root: case report.

STUDY DESIGN: A retrospective case of an isolated paramedullary hemangioblastoma originating from the first cervical root is reported. OBJECTIVE: To describe an uncommon type of spinal hemangioblastoma and its operative treatment. SUMMARY OF BACKGROUND DATA: Spinal hemangioblastoma, rare finding accounting for approximately 1.5% to 2.5% of all spinal cord tumors, may have an intramedullary, extramedullary, or extradural location. Cervical hemangioblastomas occur in approximately 45% of the cases and are intramedullary in about 83% of the cases. METHODS: A 59-year-old man presented with acute subarachnoid hemorrhage in the basal cisterns. Four-vessel angiography showed a highly vascular small tumor at the dorsolateral side of the cervicomedullary junction fed by a branch of the vertebral artery. The lesion was surgically removed. RESULTS: Total removal of the lesion was achieved after identification of both the arterial feeder and the draining vein with the aid of microvascular Doppler sonography. There were no complications, and the patient did well after surgery. CONCLUSIONS: Although hemangioblastomas occurring in the cervicomedullary area usually may cause progressive neural compression, occasionally they also can present clinically as acute subarachnoid hemorrhage. This situation requires urgent and adequate treatment as in the reported case.

[Fatal bleeding complications caused by Evans syndrome (autoimmune thrombocytopenia and hemolytic anemia) and type II autoimmune hepatitis in a 56-year-old patient]. / Fatale Blutungskomplikationen durch Evans-Syndrom (autoimmune Thrombozytopenie und hämolytische Anämie) und Autoimmunhepatitis Typ II bei einer 56-jährigen Patientin.

BACKGROUND: Autoimmune hepatitis is a rare form of hepatitis of nonviral origin. Two main subentities have been described. The classical lupoid hepatitis (type I) is characterized by hypergammaglobulinemia and the presence of lupus erythematosus cells due to antinuclear antibodies. Autoimmune hepatitis type II, which is associated with antiliver/kidney microsomal antibodies type 1 (LKM 1) shows a more aggressive clinical course than autoimmune hepatitis type I and is frequently (41% of cases) associated with other immunologic diseases. CASE REPORT: In the present study we report a case of autoimmune hepatitis Type II, associated with autoimmune thrombocytopenia and hemolytic anemia, in a 56-year-old patient. The patient's death was caused by a fatal association of a failing coagulation system due to liver dysfunction and a severe autoimmune thrombocytopenia. The aggressive course of the thrombocytopenia even after splenectomy demonstrated that the splenic enlargement due to the portal hypertension was only a minor factor in the destruction of the thrombocytes. Interestingly, some findings of this case such as the advanced age, the presence of anti-smooth muscle antibodies and HLA-DR4 are usually associated with autoimmune hepatitis type I. CONCLUSION: The findings of this case indicate that concomitant autoimmune diseases can worsen the prognosis of autoimmune hepatitis. Prednisolone and azathioprine might not be sufficient to treat aggressive forms of autoimmune hepatitis. Immunosuppressive regimens administered to recipients after organ transplantation might be used as a therapy of autoimmune hepatitis in multicenter clinical trials.

Expression of the genes of methyl-binding domain proteins in human gliomas.

DNA methylation is the most common epigenetic alteration in tumor genomes and might result in transcriptional repression of tumor suppressor genes. Moreover, recent results have demonstrated that both specific methylation patterns and functional components of the mismatch repair system are involved in the development of therapy resistance of tumor cells. Here we investigated the expression of the genes of methyl binding domain containing proteins (MBD) in human gliomas both in vivo and in vitro. We found expression of MBDs including MBD1, MBD2, MBD3 and MBD4/MED1 in all glioma cell lines and glioma biopsies. No differences existed in vitro with regard to individual MBDs and individual cell lines. In vivo, MBD1 and MBD2 were also expressed in all biopsies with only minor differences between individual tumors. MBD3 and MBD4/MED1, however, showed a correlation of expression with the grade of malignancy. Astrocytomas and anaplastic astrocytomas showed a weak expression compared with a high expression in glioblastoma multiforme.

Preconditioning-induced protection against cyanide-induced neurotoxicity is mediated by preserving mitochondrial function.

The central nervous system is one of the main target organs in cyanide toxicity. In this study, primary cultures of chick embryonic neurons were used to characterize sodium cyanide (NaCN)-induced cell death and to investigate the mechanism of NaCN-mediated preconditioning. After treatment of the cells with 1mM NaCN for 1h followed by a NaCN-free incubation period of 23 h, we observed features of apoptosis such as a reduction in nuclear size, chromatin condensation and nuclear fragmentation as evaluated by nuclear staining with Hoechst 33258 and electron microscopy. In addition, NaCN-induced neurotoxicity was reduced by the protein synthesis inhibitor cycloheximide (CHX) suggesting an active type of cell death. Most of the neurons with condensed chromatin and a shrunken nuclei also showed membrane damage at a late stage. Mitochondrial membrane potential as well as the protein levels of Bcl-2 and Bcl-x(L) decreased 15-60 min and 1-3 h after the exposure to NaCN (1mM, 1h), respectively. Preconditioning caused by incubating chick neurons with 100 microM NaCN for 30 min followed by a NaCN-free interval of 24h significantly protected the neurons against subsequent NaCN (1mM, 1h)-induced damage. Preconditioning prevented NaCN-induced decrease in the mitochondrial membrane potential as well as in the protein levels of Bcl-2 and Bcl-x(L) suggesting that preconditioning-induced neuroprotection is mediated by preserving mitochondrial function.

Activation of the anti-apoptotic Akt/protein kinase B pathway in human malignant gliomas in vivo.

In the present study we investigated two important signal transduction pathways in glioma biopsies. By Western analysis we found an overexpression of the epidermal growth factor receptor in 10 out of 27 (37%) glioblastoma multiforme (GBM), but not in astrocytomas WHO II/III which demonstrated only weak or absent expression. Only two GBM (8%) but none of the astrocytomas WHO II/III exhibited loss of PTEN expression. Activation of Akt/protein kinase B showed a close correlation with EGF receptor overexpression in human malignant gliomas since 6 out of 7 GBMs with high degrees of protein kinase B activation exhibited overexpression of the EGF receptor. In contrast, no significant differences in MAP kinase activation could be detected between individual GBMs. Our data show that EGF receptor overexpression seems to be responsible for activation of the protein kinase B whereas PTEN deletion seems to play a minor role in the dysregulation of this important pathway in human GBM in vivo.