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The idiopathic inflammatory myopathies (IIM) are a group of autoimmune diseases characterized by chronic lymphocytic and macrophagic infiltration in muscle. Because the mechanism for recruitment of these cells probably involves chemokines, we focused on the study of the expression pattern of some beta chemokines and receptors because it may provide a basis for selective immunotherapy. The expression of CCL3 (MIP-1alpha), CCL4 (MIP-1beta), CCL5 (RANTES) and their main receptors (CCR1 and CCR5) was studied by semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and immunohistochemistry in a series of 16 IIM and five controls (four normal muscles and one tonsil). Except for CCL5, strong expression was observed by RT-PCR with all molecules in all IIM subtypes in comparison to control muscle. Immunohistochemistry revealed diffuse CCL4 expression in all vessels in dermatomyositis. In both polymyositis and sporadic inclusion body myositis (s-IBM) it was restricted to vessels in the vicinity of inflammatory exudates. CCL5 expression was low, restricted to a few inflammatory cells in all IIM; CCR1 expression was mainly restricted to macrophages and s-IBM endothelial cells, whereas CCR5 was localized in inflammatory cells invading non-necrotic muscle fibres. Expressions of both receptors were also recorded in few muscle fibres. In conclusion, the upregulation of beta chemokines and receptors in IIM and their differential expression by various cells may contribute to chronic inflammation and to the peculiar distribution of inflammatory exudates in these diseases.

Sporadic inclusion body myositis (s-IBM) is the most frequent progressive acquired inflammatory myopathy in people older than 50 years. Abnormal aggregates of 'Alzheimer's proteins', including tau proteins, have been previously demonstrated in s-IBM. In the present study, we have investigated by immunohistochemistry and immunoblotting analysis the presence of tau proteins in muscle biopsy samples from patients with s-IBM and other myopathies with rimmed vacuoles, using newly developed antibodies raised against tau protein epitopes found in Alzheimer's disease brain. Tau immunoreactivity was shown in rimmed vacuoles or inclusions, preferentially with antibodies directed against phosphorylated carboxy-terminal epitopes of tau proteins. Cytoplasmic reactivity was also demonstrated in atrophic, nonvacuolated fibres, as well as in non-necrotic fibres invaded by inflammatory cells. Abnormally phosphorylated tau aggregates were also found in other compartments of the muscle fibre in s-IBM and other myopathies. Tau immunoblotting showed an electrophorectic profile of a doublet within the range of 60-62 kDa isovariants, which was different from tauopathies of the central nervous system. Finally, the unique pattern of immunoreactivity of s-IBM samples towards anti-tau antibodies is a new clue to a possible distinct subclass of peripheral tauopathy, different from the tauopathies of the central nervous system.

This study is to further confirm the diagnostic value of class I MHC detection in muscle biopsies of adult patients presenting with clinical features of dermatomyositis (DM) and to address its diagnostic value in the case of nonspecific biopsies. A retrospective study was performed on muscle biopsies in 22 patients presenting with clinical features of DM. Immunohistochemical detection of class I MHC was performed in all cases. On pathological features two groups of patients were recorded: group I (14 patients) with typical features of DM and group II (eight patients) with almost normal muscle biopsies (no inflammatory exudates, no perifascicular atrophy). Abnormal sarcolemmal class I MHC expression was recorded in all cases. In all muscle biopsies of group I patients, class I MHC expression was observed in almost all fibres but was stronger in perifascicular areas (eight patients) or was restricted to perifascicular atrophic fibres (six patients). In all muscle biopsies of group II patients, only some perifascicular fibres expressed class I MHC. According to Bohan and Peter criteria, patients were classified as definite DM (nine group I and three group II patients), probable DM (five group I and two group II patients) and possible DM (three group II patients). Abnormal perifascicular class I MHC expression is of diagnostic value in patients presenting with clinical features of DM especially when muscle biopsy fails to show typical features such as inflammatory infiltrates and/or perifascicular atrophy.

The INK4a-ARF locus encodes two unrelated proteins that both function in tumour suppression: p16INK4a and p19INK4d. Although p19INK4d expression has not been studied in central nervous system (CNS) tumours, it has been reported that p16INK4a inactivation is involved in the growth of glioblastomas. This observation has not been reported in relation to other CNS tumours. To understand further the role of p16INK4a and p19INK4d in neuroglial tumour growth, expression of both p16INK4a and p19INK4d mRNAs was studied by reverse transcription polymerase chain reaction RT-PCR in 59 neuroglial tumours, in which Ki67 labelling indices (LI) were also determined. P16INK4a mRNA was found in all pilocytic astrocytomas (7/7), in all grade II and III astrocytomas (7/7 and 4/4, respectively), in 4/12 glioblastomas, 8/8 oligodendrogliomas, 10/11 anaplastic oligodendrogliomas, 4/7 ependymomas and 3/3 anaplastic ependymomas but not in normal brain. In contrast, p19INK4d mRNA was detected in all tumours and control tissues. p16INK4a expression was associated with a low Ki67 LI in glioblastomas but not in other tumours. P16INK4a expression was not related to anaplasia in oligodendrogliomas and ependymomas. In tumours expressing p16INK4a, in situ hybridization showed a widespread expression of p16INK4a mRNA in tumour cells and in foci of microvascular proliferation. These results strongly support the concept that p16INK4a is involved in the regulation of proliferation in glioblastomas. Other cell cycle regulators which are yet unknown may also play a role in the control of oligodendrogliomas or ependymomas outgrowth. Further studies are required to evaluate the role of p19INK4d in neuroglial tumours.

The idiopathic inflammatory myopathies (IIM), including dermatomyositis (DM), polymyositis (PM), and inclusion body myositis (IBM), are regarded as autoimmune diseases. They are characterized by chronic lymphocytic and macrophagic infiltration in muscle tissue. Of particular importance in understanding the immune response to IIM is the specific pattern of locally produced cytokines. Frozen muscle tissues from IIM (5 DM, 3 PM, and 1 IBM) were used to investigate the cytokine responses. The RT-PCR technique was instrumental to determine the pattern of expression of pro-inflammatory (IL-1 beta, IL-6, TNF-alpha), Th1 (IFN-gamma IL-2), and Th2 (IL-4) cytokines. Immunohistochemistry was also used to localize morphologically IFN-gamma and IL-4. Our results show that pro-inflammatory cytokines and Th1 cytokines are mainly expressed in IIM. The accumulation of mononuclear inflammatory cells and the inflammatory syndrome in IIM are probably related in part to the production of pro-inflammatory cytokines. Moreover, the pattern of local cytokine expression is consistent with a Th1 immune response related to autoimmune diseases.

Integrins form a family of cell adhesion molecules. CD44 glycoproteins are found in a wide variety of isoforms; the most common, CD44s (standard) is widely distributed, and functions as an adhesion molecule. In this study, we have investigated immunohistochemically the distribution of some VLA integrins (alpha2, alpha5 and alpha6 chains of beta1 integrins) and CD44s in 44 meningioma specimens and normal arachnoid villi. Meningiomas were of meningothelial (16), transitional (13) and fibroblastic (15) subtypes. There were 13 grade I, 19 grade II and 12 grade III (27%). Immunoprecipitates were quantified by image analysis and correlated with clinical (age, sex, location) and morphological data (histological subtypes and grades). VLA alpha5 chain was expressed by normal arachnoid villi (mainly cap cells) and by 42 out of 44 meningioma specimens. Expression was lower in fibroblastic meningiomas (P=0.02). VLA alpha2 and alpha6 chains were not observed in normal arachnoid villi. VLA alpha2 was expressed by 15 meningiomas, VLA alpha6 by 10. Interestingly, meningiomas expressing either VLA alpha2 or alpha6 were usually of grade III (P< or =(0.05). CD44s was found on various parts of arachnoid villi and in all meningiomas although expression was higher in meningothelial and transitional than in fibroblastic (P< or =0.001). These results show that VLA alpha5 and CD44s are widely expressed by arachnoid villi and meningiomas, in contrast to VLA alpha2 and VLA alpha6. It was noted that high grade meningiomas (III) express VLA alpha2 and alpha6 suggesting that changes in integrin pattern expression are a feature of these meningiomas. Moreover, strong CD44s expression characterizes meningothelial and transitional meningiomas. Previous studies have shown that high NCAM expression is a feature of fibroblastic meningiomas whereas meningothelial and transitional meningiomas expressed mainly E-Cadherin, and that polysialylated NCAM expression was restricted to high grade meningiomas. Taken together these features suggest that each cell adhesion molecule has a characteristic pattern of expression according to meningioma subtype and grade. No correlation was seen between integrins and CD44s expression and clinical data.

We report three cases of patients who complained of myalgia showing histological features similar to tubular aggregates in their muscle biopsies. All had an elevated erythrocyte sedimentation rate without any evidence of infectious or autoimmune disease. On electron microscopy, small areas of myofibrillar degeneration, selectively in type II fibres, were found in all patients, but no tubular aggregates were seen. Although the pathogenesis of these lesions is unclear, it does seem that this condition is acquired and transient.

PDGFs and their receptors expression were examined in a series of 46 meningiomas by using specific monoclonal antibodies. The immunostaining was quantified by an image analyser and the results correlated with clinical and morphological data (histological type and grade). In addition, since the PDGFB chain is encoded by the c-sis proto-oncogene localized on chromosome 22 and because monosomy 22 has been frequently reported in meningiomas, PDGFs and PDGFRs expression have been correlated with cytogenetic analysis performed in 29 cases. The results demonstrate PDGF A and PDGF B expression in most meningioma specimens and co-expression of these growth factors in numerous cells. PDGF A and B immunoreactivity was related to histological grade. PDGFR beta expression was strong in almost all meningiomas whereas PDGFR alpha was low. PDGFR alpha expression was related to tumour location and grade and PDGFR beta to histological subtype only. The cytogenetic analysis was not related to PDGFB chain expression. Taken together these data further confirm PDGF and PDGFR expression in human meningioma; PDGF may exist as an heterodimer (AB) as well as its receptor. The lack of correlation between cytogenetic analysis and PDGF values, the low level of PDGFB in recurrent meningiomas suggests that it is unlikely that the c-sis proto-oncogene plays an important role in the genesis of meningiomas.

A primary extraspinal medulloepithelioma with lung metastases is reported. The tumour was located in the presacral area. Microscopically, it showed typical features of medulloepithelioma with focal ependymal differentiation. Medulloepitheliomas are malignant tumours of primitive neuro-epithelium usually involving the cerebral hemispheres. This report demonstrates their possible extraspinal presacral occurrence. By immunohistochemistry, neuron-specific-enolase, S100 protein, vimentin, cytokeratin and glial fibrillary acidic protein were found in some tumour cells. Electron microscopy demonstrated poorly differentiated cells forming stratified epithelium resting on a basal lamina and short junctional complexes at the apical pole. Ultrastructural evidence of ependymal differentiation was observed. Presacral medulloepithelioma may arise from undifferentiated embryonic cells forming the presacral remnants of the neurenteric canal.