Pilomyxoid astrocytoma of the spinal cord in an adult.

We report a 45-year old woman with a pilomyxoid astrocytoma (PMA) of the cervical spinal cord with a rapid clinical course and fatal outcome. Moreover, two family members of the patient were reported to have brainstem tumours with similar histopathological features. This may be the first report of familial PMAs.

Renin and angiotensinogen expression and functions in growth and apoptosis of human glioblastoma.

The expression and function in growth and apoptosis of the renin-angiotensin system (RAS) was evaluated in human glioblastoma. Renin and angiotensinogen (AGT) mRNAs and proteins were found by in situ hybridisation and immunohistochemistry in glioblastoma cells. Angiotensinogen was present in glioblastoma cystic fluids. Thus, human glioblastoma cells produce renin and AGT and secrete AGT. Human glioblastoma and glioblastoma cells expressed renin, AGT, renin receptor, AT(2) and/or AT(1) mRNAs and proteins determined by RT-PCR and/or Western blotting, respectively. The function of the RAS in glioblastoma was studied using human glioblastoma cells in culture. Angiotensinogen, des(Ang I)AGT, tetradecapaptide renin substrate (AGT1-14), Ang I, Ang II or Ang III, added to glioblastoma cells in culture, did not modulate their proliferation, survival or death. Angiotensin-converting enzyme inhibitors did not diminish glioblastoma cell proliferation. However, the addition of selective synthetic renin inhibitors to glioblastoma cells decreased DNA synthesis and viable tumour cell number, and induced apoptosis. This effect was not counterbalanced by concomitant addition of Ang II. In conclusion, the complete RAS is expressed by human glioblastomas and glioblastoma cells in culture. Inhibition of renin in glioblastoma cells may be a potential approach to control glioblastoma cell proliferation and survival, and glioblastoma progression in combination therapy.

Expression of Tie-2 in human peripheral and autonomic nervous system.

Tie-2, a tyrosine kinase receptor, is essential for vascular integrity by regulating cellular adhesion between pericytes and endothelial cells. The aim of this study was to identify sites of expression of Tie-2 other than the vasculature. Tie-2 expression was first detected in human colon by Western blotting and reverse-transcription-polymerase chain reaction (RT-PCR) in tissue extracts. The presence of the Tie-2 mRNA and protein was detected by immunohistochemistry and in situ hybridization in cells of the colon myenteric and submucosal plexus, in both neuronal and Schwann cells. Tie-2 protein was also found in the nervous system of the female urogenital tract. In the human sciatic nerve and schwannoma, RT-PCR, Western blotting and immunohistochemistry analysis further confirmed the presence of Tie-2 mRNA and protein in non-autonomic peripheral nervous tissue. In conclusion, using several approaches and tissues we have demonstrated the presence of Tie-2 in human peripheral and autonomic nervous tissue, suggesting a role for Tie-2 in neural tissue. Thus, attempts to disrupt the tumour vessels by manipulation of the Tie-2 system in tumours may result in side-effects in peripheral nerves.

Reduced latency but no increased brain tumor penetrance in mice with astrocyte specific expression of a human p53 mutant.

p53-germline mutations located in the core DNA-binding domain have been associated with a more dominant tumor penetrance especially for breast cancer and brain tumors. We previously reported an unusual accumulation of CNS tumors associated with a unique p53 germline mutation, Y236delta (deletion of codon 236). To test whether this tissue-specific tumor predisposition reflects a gain-of-function activity of Y236delta, we generated transgenic mice expressing Y236delta in astrocytes using the regulatory elements of the glial fibrillary acidic protein (GFAP) gene. After transplacental exposure to N-ethyl-N-nitrosourea (25 mg/kg BW) brain tumors developed in 18% (7/39) of GFAP-Y236delta transgenic p53-/- mice, while in p53+/- mice the incidence was 28% (11/40) (P>0.3). However, the mean tumor latency for GFAP-Y236delta/p53+/- mice was significantly shorter than for p53+/- mice, with 19.9 weeks vs 31.6 weeks (P=0.039), respectively. Taken together, cell specific expression of Y236delta results in an acceleration of tumor progression but does not confer a higher tumor penetrance. Conceivably, the transdominant effect of Y236delta provided a growth advantage early in the progression of neoplastic cells, since the endogenous p53 wild-type allele was lost in all brain tumors independent of the genotype. This reflects well observations from human astrocytic neoplasms with p53 mutations.

The endothelin system in human glioblastoma.

Endothelin-1 (ET-1) is a powerful mitogenic and/or anti-apoptotic peptide produced by many cancer cells. To evaluate the potential role of the endothelin system in glioblastoma we first determined the cellular distribution of the mRNA and proteins of the components of the endothelin system, preproendothelin-1 (PPET-1), endothelin-converting enzyme-1 (ECE-1), and ET(A) and ET(B) receptors in human glioblastoma tissue and glioblastoma cell lines. PPET-1, ECE-1, and ET(A) receptor were highly expressed in glioblastoma vessels and in some scattered glioblastoma areas whereas ET(B) receptor was mainly found in cancer cells. This suggests that glioblastoma vessels constitute an important source of ET-1 that acts on cancer cells via the ET(B) receptor. Four human glioblastoma cell lines expressed mRNA for all of the components of the ET-1 pathway. Bosentan, a mixed ET(A) and ET(B) receptor antagonist, induced apoptosis in these cell lines in a dose-dependent manner. Apoptosis was potentiated by Fas Ligand (APO-1L, CD95L), a pro-apoptotic peptide, only in LNZ308 cells, corresponding to the known functional Fas expression in these cell lines. LNZ308 cells also expressed the long and short forms of the cellular FLICE/caspase-8 inhibitory protein (FLIP). Bosentan and a protein kinase C inhibitor down-regulated short FLIP in these cells. ET-1 induced transient phosphorylation of extracellular signal-regulated kinase but did not induce long-term thymidine incorporation in LNZ308 glioblastoma cells. These results suggest that, in glioblastoma cells, ET-1, mainly acting via the ET(B) receptor, is a survival/antiapoptotic factor produced by tumor vasculature, but not a proliferation factor, involving protein kinase C and extracellular signal-regulated kinase pathways, and stabilization of the short form of FLIP.

Clinicopathological and molecular biological studies in a patient with neurolymphomatosis.

We describe a patient with a clinical disorder that resembled vasculitic neuropathy in which peripheral nerves were successively affected over several months, but without systemic involvement. An initial muscle biopsy near the involved nerves showed signs of nonspecific inflammation around the muscle and nerve fibers. Immunosuppressive treatment resulted in a dramatic reduction in pain, but relapses of the disease eventually occurred, and the patient died 22 months after onset of the first symptoms. Pathologically, a malignant non-Hodgkin's B-cell lymphoma, restricted to the intra- and extradural peripheral nervous system, was found. The demonstration by Southern blotting of immunoglobulin heavy chain gene rearrangement confirmed the monoclonal nature of the lymphomatous cells. In situ hybridization tests for Epstein-Barr and herpes virus subtypes were negative. Our case underlines i) how difficult diagnosis can be despite extensive investigations, ii) the usefulness of immunosuppressive treatment in the early stage of the disease, iii) the importance of immunostaining and genome analysis for distinguishing between different types of human neurolymphomatosis, and iv) the fact that the initial inflammatory process in the muscle biopsy may be interpreted either as a paraneoplastic effect of the lymphoma or as a viral inflammatory neuromyopathy that triggers the development of the malignant lymphoma.

p53 gene mutation and ink4a-arf deletion appear to be two mutually exclusive events in human glioblastoma.

P16 and P14ARF are two tumor suppressors encoded by the locus ink4a-arf which is frequently deleted in human tumors. Recent experiments performed with mouse embryonic fibroblasts have shown that P14ARF is an upstream regulator of the P53 pathway. This raises the question as to whether in human tumors the loss of p14arf and mutation of p53 are mutually exclusive events which segregate with genetic alterations at other loci. To examine this question we performed a multigenic analysis on 29 gliomas. We analysed p53 and p14arf in relation with five other genetic loci encoding the most frequently mutated genes in human gliomas: cdkn2a, mdm2, egfr, pten and the chromosomal regions 10q23.3 and 10q25-26. Our study shows for the first time that p53 mutations and p14arf deletions appear mutually exclusive in human glioblastoma, suggesting that they may be functionally redundant in glioma tumorigenesis. The P53 pathway is, therefore, disrupted in 81.8% of malignant gliomas (WHO grades III and IV), either by mutation of the p53 gene (31.8%) or by p14arf deletion (54.5%). These tumors further showed MDM2 overexpression (9.1%), egfr oncogene amplification/egfr overexpression (50%), pten mutations (27.3%) and loss of heterozygosity (LOH) at the chromosomal regions 10q23.3 (86.4%) and 10q25-26 (100%). These alterations did not segregate with p53 mutations or p14arf deletions, while p14arf and cdkn2a were always deleted.

Cytochrome P-450 activities in human and rat brain microsomes.

The role of cytochrome P450 in the metabolism of dextromethorphan, amitriptyline, midazolam, S-mephenytoin, citalopram, fluoxetine and sertraline was investigated in rat and human brain microsomes. Depending on the parameters, the limit of quantification using gas chromatography-mass spectrometry methods was between 1.6 and 20 pmol per incubation, which generally contained 1500 microg protein. Amitriptyline was shown to be demethylated to nortriptyline by both rat and human microsomes. Inhibition studies using ketoconazole, furafylline, sulfaphenazole, omeprazole and quinidine suggested that CYP3A4 is the isoform responsible for this reaction whereas CYP1A2, CYP2C9, CYP2C19 and CYP2D6 do not seem to be involved. This result was confirmed by using a monoclonal antibody against CYP3A4. Dextromethorphan was metabolized to dextrorphan in rat brain microsomes and was inhibited by quinidine and by a polyclonal antibody against CYP2D6. Only the addition of exogenous reductase allowed the measurement of this activity in human brain microsomes. Metabolites of the other substrates could not be detected, possibly due to an insufficiently sensitive method. It is concluded that cytochrome P450 activity in the brain is very low, but that psychotropic drugs could undergo a local cerebral metabolism which could have pharmacological and/or toxicological consequences.

Early lacunar strokes complicating polyarteritis nodosa: thrombotic microangiopathy.

OBJECTIVE: To determine the patterns and mechanisms of polyarteritis nodosa (PAN)-associated strokes (PANAS). BACKGROUND: Strokes are reputed to be rare complications of PAN and to occur at a late stage (2 to 3 years). The cause of stroke is unknown but may be related either to atherosclerosis-like occlusive vasculopathy, caused possibly by hypertension or corticosteroid (CS) use, or to vasculitic arterial occlusion. METHODS: Clinical and radiologic patterns, latencies, and current therapy at onset in 15 PANAS patients (4 of the authors' and 11 published cases) were analyzed. RESULTS: A lacunar stroke syndrome (11/15 cases, 73%) was the most frequent stroke pattern in PANAS (multiple, small, deep infarcts in 6, [55%], pontine lacunae in 3 [27%], and leukoaraiosis in 2 [18%]), followed by pure lobar hematoma and bilateral, possibly cardioembolic, large ischemic infarcts (2 cases each). A stroke latency shorter than that previously established (within 8 months in 73% of cases; mean latency, 6.5 months) and a close relationship between the use of CS and stroke in PAN also were found. Of the 77% of first-time or recurrent lacunar strokes that developed despite CS therapy, 80% appeared within 6 months and 50% within 3 weeks of CS initiation. CONCLUSION: Early lacunar stroke syndrome, related to deep small- or pontine-penetrating artery thrombotic microangiopathy rather than vasculitis, was the most frequent PANAS pattern. This vasculopathy may be aggravated by corticosteroid (CS) therapy enhancement of either platelet thromboxane A2 production or arterial wall fibrosis. Thus, antiplatelet drugs in association with CS may be advisable for preventing stroke occurrence or recurrence in PAN.

[Inflammatory and infectious manifestations of the nervous system]. / Manifestations inflammatoires et infectieuses du système nerveux.

The Central Nervous System is the site of a wide variety of inflammatory and infectious diseases. Some disease entities have been in the focus of interest in recent years and progress has been achieved in our understanding of some chosen domains. We will review recent progress in our knowledge about transmissible spongiformes encephalopathies and AIDS-associated lesions, and briefly discuss cerebral vasculitis, granulomatous diseases and the most frequent infections by parasites.

[Cardiac fibrosarcoma discovered by cerebral metastases]. / Fibrosarcome cardiaque découvert par métastases cérébrales.

Primary heart tumors are rare, and the fibrosarcomas are exceptional. We present the findings in a 78 year old female who has been hospitalized in April 1997 with a history of 4 months of malaise, headaches and weight loss. Clinical examination showed a right lateral homonymous hemi-anopsia. Computed tomography (CT-Scan) of the brain showed two lesions in the occipital and temporal lobe, consistent with metastasis. Thoracic and abdominal-pelvic CT-Scan revealed a voluminous mass of the left auricle that has been interpreted as a probable sarcoma. Biopsy specimen of one of the cerebral lesions, performed at the Centre hospitalier universitaire vaudois (CHUV) on April 29th 1997, revealed fragments of a poorly differentiated sarcoma. After referral back to Neuchâtel, the patient suffered suddenly three weeks later from a cerebral vascular insult with instant onset of deep coma. She deceased on May 27. At autopsy we found a neoplastic lesion of the left auricle with invasion of the pulmonary veins. The histological appearance is similar to the appearance of the cerebral metastasis, showing a proliferation of spindled cells with a partial positivity for Vimentine. It was classified as a fibrosarcoma. Metastasis were found only in the brain with postoperative ischemic left occipitotemporal necrosis and neoplastic emboli.--We are discussing the various incidences of cardiac neoplasms in autopsies or biopsies.

Cells with TP53 mutations in low grade astrocytic tumors evolve clonally to malignancy and are an unfavorable prognostic factor.

It is important to understand how low grade tumors recur and progress to malignant lesions since this dramatically shortens patient survival. Here, we evaluated the concept that malignant progression and poor prognosis of low grade astrocytic tumors are TP53 dependent through clonal expansion of mutated cells. TP53 status was established in primary and recurrent tumors from 36 patients with WHO grade II astrocytic tumors and two tumor types were found. Tumors from 14 patients (39%; type 1) had TP53 mutated cells, and 92% of these recurred with 57% progressing to malignancy. The evolution of TP53 mutated cells before and after progression was examined using a clonal analysis procedure in yeast. Malignant progression was accompanied by an increased percentage of mutant TP53 (red) yeast colonies resulting from monoclonal expansion of cells with mutated TP53. The presence of TP53 mutations in WHO grade II astrocytic tumors was associated with malignant progression (P=0. 034, chi2 test) and shorter progression-free survival (PFS; 47.6+/-9. 6 months for TP53-mutated tumors vs 67.8+/-8.2 months for TP53-wild type tumors, P<0.05, log-rank test). Tumors from 22 patients (61%; type 2) were without TP53 mutations, and 64% of these recurred without a change in TP53 status, although 41% progressed to malignancy. This suggests that TP53 mutation is not an initiating or progression event in the majority of low grade astrocytic tumors. Our study also indicates that irradiation for WHO grade II astrocytic tumors might be associated with poor outcome (P<0.0001) and this was independent of TP53 status. These findings have important implications in the clinical management of patients with low grade astocytoma and provide new support to the clonal evolution model for tumor progression.

[Facial myositis: a localized form of generalized myositis?]. / Myosite faciale: une forme localisée de myosite généralisée?

We report a case of myositis presenting as an apparently unique progressive facial weakness. The only biological abnormality after an 8-year follow-up was an immunocytoma. Molecular analyses excluded facioscapulohumeral muscular dystrophy. Based on this single case and a review of the literature, we suggest a continuum between focal myositis and generalized myositis.

Absence of p53 gene mutations in a tumor panel representative of pilocytic astrocytoma diversity using a p53 functional assay.

Although p53-gene mutations occur with significant frequency in diffuse low-grade and high-grade astrocytomas, and are postulated to play an important role in tumorigenesis in these cases, the role of the p53 gene in pilocytic astrocytomas remains unclear. Published data using DNA-based assays for p53-gene analysis in these tumors have shown contradictory results in mutation frequency (0-14%). It is not known whether these heterogeneous results stem from the biological diversity of this tumor group or from technical problems. To re-evaluate p53-gene status in pilocytic tumors, we analyzed 18 tumors chosen to represent the clinical and biological heterogeneity of this tumor type with respect to anatomical location, patient age, gender, ethnic origin (Caucasian or Japanese) and the concomitant occurrence of neurofibromatosis type 1 (NF1). All primary tumors were histologically diagnosed as pilocytic astrocytoma (WHO grade I), except for one anaplastic pilocytic astrocytoma (WHO grade III) which developed in an NF1 patient and recurred as glioblastoma multiforme (WHO grade IV). p53 mutations were detected using an assay in yeast which tests the transcriptional activity of p53 proteins synthesized from tumor mRNA-derived p53-cDNA templates. None of 18 tumors, including 3 NF1-related tumors, showed p53-gene mutations between and including exons 4 and 11. We conclude that p53-gene mutations are extremely rare findings in pilocytic astrocytomas, and are absent even in those exceptional cases in which malignant progression of such tumors has occurred.

Familial cardiomyopathy and distal myopathy with abnormal desmin accumulation and migration.

Desminopathies form a heterogeneous group of myopathies characterised by pathological aggregations of desmin. We report a family, where mother and daughter presented with an atrioventricular block and a slowly progressive distal muscular weakness, with non-homogeneous focal atrophy on computed tomography scans. The mother developed a severe global heart insufficiency necessitating a heart transplantation at 56 years of age. Skeletal muscle biopsies were characterised by inclusion bodies strongly expressing desmin and alpha B-crystallin, with a predominantly subsarcolemmal localisation. Ultrastructurally most inclusions corresponded to non-membrane bound granulo-filamentous material with disruption of myofibrils. An immunoblot showed a hyperintense desmin band at 53 kDa and a second band at 49 kDa, the latter being absent in controls. The cardiac muscle of the explanted heart showed very similar inclusions. These cases illustrate that in this distinct subtype of desminopathies the cardiac muscle alterations are comparable with those observed in skeletal muscle, and suggest the possibility of a primary desmin pathology.

Ragged-red fibers and complex I deficiency in a neonate with arthrogryposis congenita.

We describe a neonate with hypotonia, weakness, early death owing to respiratory failure, and a severe form of arthrogryposis multiplex congenita. Postmortem studies revealed numerous ragged-red fibers and central nervous system abnormalities consistent with a mitochondrial disease. No NADH:ubiquinone-1 oxidoreductase (complex I) activity could be detected in skeletal muscle. These findings suggest that mitochondrial cytopathies can be associated with arthrogryposis multiplex congenita and should therefore be sought in neonates presenting with severe arthrogryposis.

Wernicke's encephalopathy with ballooned neurons in the mamillary bodies: an immunohistochemical study.

Two cases of Wernicke's encephalopathy with the rare phenomenon of ballooned neurons in the mamillary bodies are reported. Both patients suffered from acute Wernicke's symptoms starting approximately two weeks before death. The mamillary bodies contained grossly enlarged, ballooned neurons, in one case associated with focal necrosis. The affected neurons were immunoreactive for phosphorylated neurofilament (160 and 200 kDa), and synaptophysin. Ubiquitin and alpha beta-crystallin expression were not detected. The mamillo-thalamic tract appeared normal in both cases. There was a marked associated microglial reaction, as shown by the antibody Ki-MIP. It is concluded that the ballooning of mamillary neurons reflects an acute retrograde reaction to primarily axonal damage. Rather than being a rare manifestation of the disease, these cases may constitute a typical intermediate early stage (10-15 days) in the development of Wernicke's encephalopathy).

Phantom face: conscious correlate of neural reorganization after removal of primary sensory neurones.

A patient in whom mandibular and maxillary parts of right trigeminal ganglion were removed experienced referred sensations after stimulation of the right hand and right forehead. She described them either as parallel to the perception at the actual stimulation site or as coming uniquely from a (non-existent) stimulation of denervated territory. The latter occurred in 6-19% of stimulations performed on the right forehead and on digits 1, 3 and 4 of the right hand. Thumb stimulations were localized on the right side of the face, stimulations of right forehead, middle and ring fingers more precisely on right cheek. Referred sensations were present on postoperative day 7 and had a more real-like quality than 5 days later.

[Peripheral nerve and spinal cord complication in intravenous heroin addiction]. / Complications neurologiques périphériques et médullaires de la toxicomanie intraveineuse à l'héroïne.

The neurological complications observed in 6 HIV negative intravenous drug users are reported. Four developed acute neuromuscular involvement in a lumbosacral or brachial distribution with rhabdomyolysis, myoglobinuria, hypovolemia, renal and hepatic failure in the 3 most severely affected patients. Despite evidence of immunologic abnormalities and especially presence of anti-heroin antibodies, we feel that causative mechanisms include mixed compression and ischemia with an underlying toxic myopathy, resulting in segmental myopathy with secondary compression of peripheral nerves. Two patients developed myelopathy with acute or chronic onset. The mechanisms were vascular with spinal cord infarction in the acute form and probably infectious with secondary compressive arachnoiditis in the chronic form. In these 2 patients with myelopathy, outcome was poor.