Correlation between PMP-22 messenger RNA expression and phenotype in hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a deletion in chromosome 17p11.2, which includes the gene for the peripheral myelin protein 22 (PMP-22). A "gene dosage" effect is probably the mechanism underlying HNPP, but the amount of PMP-22 mRNA in sural nerves of HNPP patients is highly variable and the role of PMP-22 underexpression in impairing myelination has yet to be clarified. We have studied 6 genetically proven HNPP patients, to evaluate the relationship between PMP-22 mRNA levels, and clinical, neurophysiological, and neuropathological findings. Underexpression of PMP-22 mRNA correlates with disease severity and with mean axon diameter and g ratio, but not with myelin thickness, number of "tomacula," or nerve conduction parameters. Our findings further confirm that underexpression of PMP-22 is the main pathogenetic mechanism underlying the severity of clinical symptoms and signs in HNPP. Smaller axons in sural nerves of HNPP patients with lower PMP-22 levels suggests that underexpression of PMP-22 may also affect axon development.

Advances in Charcot-Marie-Tooth disease research: cellular function of CMT-related proteins, transgenic animal models, and pathomechanisms. The European CMT Consortium

The First Workshop of the European Consortium on Charcot-Marie-Tooth (CMT) disease brought together neuroscientists, molecular and cell biologists, neuropathologists, neurologists, and geneticists with a common interest in the understanding of the fundamental mechanisms that underlie the pathogenesis of CMT. The interdisciplinary group of 25 expert scientists discussed recent advances in (i) molecular genetics and histopathology of CMT, (ii) development of suitable animal models, (iii) understanding of the cellular function of CMT-related proteins, and (iv) studies using nerve biopsies from CMT patients. In this minireview, we summarize the key findings presented and discuss their impact on CMT research.

Underexpression of messenger RNA for peripheral myelin protein 22 in hereditary neuropathy with liability to pressure palsies

Hereditary neuropathy with liability to pressure palsies (HNPP) is associated with a deletion in chromosome 17p11.2, including the gene for the peripheral myelin protein 22 (PMP-22). Because of the proposal that a decreased dosage of the PMP-22 gene was the cause of HNPP, we evaluated sural nerves from eight patients with the 17p11.2 deletion and from five normal controls. The relative amount of PMP-22 mRNA was significantly lower in HNPP patients compared with normal controls (p < 0.02) using a semiquantitative reverse transcriptase-polymerase chain reaction. There was no significant decrease of Pzero mRNA. Sural nerves from HNPP patients showed normal immunostaining with monoclonal antibodies against PMP-22, Pzero, and myelin basic protein, and only rare myelinated fibers, classified as "tomacula," showed a patchy staining of the compact myelin with monoclonal antibody against PMP-22. The significant underexpression of PMP-22 mRNA in HNPP patients compared with normal controls demonstrates that a decreased dosage of the PMP-22 gene is the most likely pathogenetic mechanism in HNPP.

Simulation of soft-tissue tumor excisions: a multimodal interactive approach

Total 3-D reconstruction of the tumor size, shape, and relations with surrounding structures using CT, MRI, sonography, and angiography images can make simulated radical resection of soft-tissue sarcomas possible, thus sparing normal tissues. With our approach, starting from three MR images for a given patient, a new single image representation of all three parameters is generated by using two different techniques on a workstation in a standard UNIX and X-11 environment. The first one is a transformation linking together the MR parameters and the RGB (red, green, blue) color components. The second one is an unsupervised segmentation method based on a number of neural and fuzzy models. We can dinamically render and update a stereo display using field sequential presentation of left and right eye views on the monitor, with Cristal Eyes LCD shutter eyewear (StereoGraphics Inc., San Rafael, CA) to view it. As 3D locating tool, a 3D locating control system based on low-frequency magnetic fields (Polhemus Fastrak) has been chosen. Simulations of soft-tissues excisions may be performed in this interactive environment with augmented-reality modalities. All this, in our experience, has greatly facilitated the simulation of soft-tissue sarcoma excisions.

An "augmented-reality" aid for plastic and reconstructive surgeons

Starting from MR and CT images for a given patient, a new single image representation of all parameters has been generated by using false-color techniques in a standard UNIX and X-11 environment. A transformation linking together the MR, CT parameters and the RGB (red, green, blue) color components has been used. Moreover an unsupervised segmentation method based on a number of neural and fuzzy models may directly produce segmented image volumes. Each image of the various sequences has been interactively displayed by using a specifically designed application. The resulting images have been displayed on a stereo monitor allowing the three-dimensional rendering of visual data through LCD shuttered glasses. Moreover, a 3-D control system based on low frequency magnetic fields has been used, while a bandheld Polhemus stylus could be used as an electronic knife for dissecting the 3-D data set and for defining flaps and grafts. Bone or soft-tissue contour can be analyzed, and sections can be removed from the model to allow a view of the underlying structures. Flaps and grafts obtained utilizing the above-reported techniques can be fitted exactly, without repeated removal and recarving. Nuances of depth, tapering, and arc are carved directly into the bone, while chances of asymmetry are markedly diminished. In this way, moreover, anesthetic times are reduced by more efficient utilization of operative time, which usually offsets the increased cost of imaging.

De novo duplication in Charcot-Marie-Tooth type 1A

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Use of cosH1 probe in hereditary neuropathy with liability to pressure palsies: a reliable genetic test for demonstration of identical size of 17p11.2 deletion in unrelated patients

We describe pulsed-field gel electrophoresis (PFGE) analysis of 10 unrelated Italian families and seven isolated cases with hereditary neuropathy with liability to pressure palsies (HNPP). Our sample includes patients with different clinical features, varying from classical liability to pressure palsies to ingravescent polyneuropathy. The frequency and the uniformity in size of the 17p11.2 deletion was evaluated by using cosH1 probe from the Charcot-Marie-Tooth neuropathy type 1A (CMT1A)-REP region. The presence of the deletion was demonstrated in all our patients; furthermore, the deletion was of identical size, although our patients had different clinical features. Molecular analysis of the 17p11.2 region by PFGE method proved to be a reliable and non-invasive method of diagnosis in HNPP cases both familial and isolated.

Segmentation of multivariate medical images via unsupervised clustering with "adaptive resolution"

The need for quantitative information is becoming increasingly important in the clinical field. In this paper we present an interactive X11 based system, devoted to segmentation of multivariate medical images, including an unsupervised neural network approach to clustering. The following steps are considered in the analysis sequence: feature extraction, reduction of dimensionality, unsupervised data clustering, voxel classification, interactive post-processing refinement. The environment turns out to be extremely interactive, thus making the user able to display and modify data during processing, to set parameters, to choose different methods and different tools for each step, and to define online the whole analysis sequence.

Expression of high- and low-affinity neurotrophin receptors on human transformed B lymphocytes

We performed high-sensitivity flow cytometry and Western blotting to study the expression of the low-affinity NGF receptor (p75NGFR) and of the transmembrane tyrosine kinase (Trk) family of high-affinity receptors for the different neurotrophic factors on Epstein-Barr virus (EBV)-transformed human B lymphocytes. Reverse transcriptase (RT) polymerase chain reaction (PCR) with single and multiple sets of primers (multiplex RT-PCR) was used to survey the repertoire of neurotrophin receptor transcripts in this cell line. We demonstrated that transformed B cells express detectable levels of Trk b and its mRNA. Conversely, negative results were obtained for p75NGFR, Trk a, and Trk c. Exposure of EBV-transformed B lymphocytes to brain-derived neurotrophic factor (BDNF) triggered the phosphorylation of Trk b, as demonstrated by Western blots of cell lysates probed with monoclonal antibody against phosphotyrosine.

Insulin-like growth factor-II as a paracrine growth factor in human neuroblastoma cells

The human neuroblastoma line, SK-N-SH, has been subcloned into SH-SY5Y, a neuroblast N cell line, and SH-EP, an epithelial Schwann S cell line. We have previously shown that SH-SY5Y neuroblastoma cells produce insulin-like growth factor II (IGF-II), which acts by an autocrine mechanism to stimulate cell growth. In the current study, we examined the effect of IGF-II on SH-EP neuroblastoma cells. Northern blot and reverse transcriptase-polymerase chain reaction analyses indicate that SH-EP cells do not produce IGF-I or IGF-II but express the type I and type II IGF receptors (IGF-IR and IGF-IIR). Cell surface expression of IGF-IR, assessed by fluorescence-activated sorting, was lower in SH-EP cells than in SH-SY5Y cells. Immunoprecipitation of IGF-IR, followed by anti-phosphotyrosine or anti-IGF-IR immunoblotting, demonstrated functional expression of these receptors in both cell types and confirmed the lower level of IGF-IR expression in SH-EP cells. IGF-II promoted SH-EP cell growth in the presence of low concentrations of calf serum (0.1-0.3%) or 10 ng/ml epidermal growth factor (EGF). IGF-II stimulation of SH-EP growth was eliminated by the IGF-IR blocking antibody (alpha IR-3) but not by an IGF-IIR blocking antibody. Stimulation of cell growth via this receptor was also indicated by the ligand specificity for IGF analogs and insulin (IGF-II approximately IGF-I approximately des(1-3)IGF-I >> insulin). These results indicate that in the presence of a permissive factor such as calf serum or EGF, IGF-II stimulates SH-EP cell growth via the IGF-IR. Collectively, these data suggest that within primary neuroblastomas, IGF-II may act as a paracrine factor to contribute to the promotion of S cell growth.

Hereditary neuropathy with liability to pressure palsies and inherited brachial plexus neuropathy--two genetically distinct disorders

OBJECTIVE

To determine whether hereditary neuropathy with liability to pressure palsies (HNPP) and inherited brachial plexus neuropathy (IBPN) are genetically distinct disorders and to evaluate the usefulness of fluorescence in situ hybridization (FISH) for diagnosing HNPP in individual patients.

DESIGN

We studied representative metaphases from patients with HNPP and IBPN with use of FISH and a DNA probe.

MATERIAL AND METHODS

With use of FISH, 14 persons from 4 unrelated families with HNPP and 7 members from 3 unrelated families with IBPN were studied. We used a DNA probe that hybridizes to chromosome 17p11.2 in an area thought to be deleted in HNPP.

RESULTS

Each participant in this study who had HNPP showed deletion of this chromosome site. Each of the 10 control subjects and 7 patients with IBPN showed normal fluorescent signals on both number 17 chromosomes.

CONCLUSION

These results demonstrate that HNPP and IBPN are genetically different. FISH with this probe is a sensitive and specific method for detecting the chromosomal deletion in individual patients without the use of family studies or linkage analysis.

Molecular analysis of three cases with hereditary motor and sensory neuropathy with myelin outfolding

We describe three patients affected by a congenital motor and sensory neuropathy with excessive myelin outfoldings (MOs) [15]. Clinical and electrophysiological features supported the diagnosis of hereditary motor and sensory neuropathy. We previously reported a genetic study on these three patients, which failed to demonstrate either the duplication in chromosome 17p11.2 or the mutations at exons 1 and 2 of the peripheral myelin protein gene (PMP-22) and suggested an autosomal recessive (AR) inheritance. In this study we described the absence of the most common mutations, which characterized other forms of hereditary motor and sensory neuropathy (HMSN). In particular the absence of molecular changes in the PMP-22 gene definitively sets HMSN with MOs apart from the more common CMT1A, hereditary neuropathy with liability to pressure palsies (HNPP) and progressive sensory-motor polyneuropathy with tomaculous changes at sural nerve biopsy.

Progressive sensory-motor polyneuropathy with tomaculous changes is associated to 17p11.2 deletion

We examined for the presence of 17p11.2 deletion, by Southern blotting and fluorescent in situ hybridization, 3 cases with progressive sensory-motor polyneuropathy and diffuse tomaculous changes at sural nerve biopsy. We demonstrated in all the cases the 17p11.2 deletion, previously reported in hereditary neuropathy with pressure palsy, an inherited disorder of the peripheral nervous system with similar pathologic changes but a different clinical phenotype. The molecular study of the 17p11.2 region should be considered as a non invasive method for differential diagnosis in selected cases of progressive polyneuropathy.

Molecular diagnosis of hereditary neuropathy with liability to pressure palsies (HNPP) by detection of 17p11.2 deletion in Italian patients

Hereditary neuropathy with a liability to pressure palsies (HNPP) is an autosomal dominant disorder characterized by recurrent pressure palsies generally precipitated by minor trauma; weakness and paraesthesia usually improve and recover completely in a few months. By Southern blotting and fluorescent in situ hybridization analysis we confirm the presence of a 17p11.2 deletion in familial and in isolated cases of HNPP, suggesting that molecular analysis of the 17p11.2 region could also be a reliable and non-invasive method of diagnosis in sporadic cases, where a correct diagnosis usually requires a nerve biopsy. Although HNPP is a mild disease and not all patients seek medical attention, a presymptomatic diagnosis is useful for assessing the risk during genetic counselling, due to the inheritance of the mutation.

[An expert system for the planning of whole-body irradiation treatments]

Total body irradiation (TBI) combined with intensive chemotherapy and bone marrow transplantation is used with increasing success for the treatment of hematologic malignancies with severe prognosis. An expert system, developed on the basis of the experience acquired during the last years in our department, has been designed to optimize the different treatment steps. The choice of an expert system is based on its capabilities in reconstructing a rule-based reasoning through the combination of theoretical and empirical knowledge. Particularly, a subsystem dealing with the steps to be taken to optimize treatment in TBI has been designed using medical and physical data. Our system can determine radiation treatment variables together with a sequence of quality control procedures. Moreover, indications are given about short, medium and long term damage probabilities and toxicity estimates, both derived from literature data and our personal series of cases. Treatment quality can be assessed and the different techniques compared using these data. This project is aimed at providing physicians and physicists with useful clinical suggestions for TBI setting for bone marrow transplantation.

The POEMS syndrome: report of six cases

We report six patients affected by POEMS syndrome (Polyneuropathy, Organomegaly, Endocrinopathy, Monoclonal gammopathy, and Skin changes), a peculiar multiorgan disease frequently associated with osteosclerotic myeloma or other plasma cell disorders. Sensorimotor polyneuropathy was associated with multisystem involvement in all of the patients, with osteosclerotic myeloma in 2 cases, monoclonal gammopathy of undetermined significance in 2 cases and Castleman's disease in the final two. In all of the patients, sural nerve biopsy findings were consistent with a mixed, axonal and demyelinating neuropathy. Increased levels of Interleukin-6 were found in two cases, but the pathogenesis of the disease is far from established.

Hereditary motor and sensory neuropathy with myelin outfolding: clinical, genetic and neuropathological study of three cases

We describe 3 patients affected by a congenital motor and sensory neuropathy with excessive myelin outfoldings (MOs). Clinical and electrophysiological features supported the diagnosis of hereditary motor and sensory neuropathy (HMSN). The genetic study failed to demonstrate either the duplication in chromosome 17p11.2 or the mutations at exons 1 and 2 of the myelin protein gene, PMP-22, recently observed in HMSN type Ia, and suggested an autosomal recessive (AR) inheritance. Sural nerve biopsy revealed a demyelinating process with prominent hypertrophic changes and excessive MOs formation. The percentage of MOs was significantly higher than in 3 age-matched HMSN Ia patients. MOs were morphologically and morphometrically different from tomacular-like thickenings of myelin. Myelin thickness was significantly lower than in the three HMSN Ia controls and linear regression showed a thinner myelin related to axon diameter. The reported cases demonstrate that HMSN with MOs is a well defined variant of HMSN and that a primary defect in the myelination process may be proposed as a possible pathogenic mechanism.

17p11.2 duplication is a common finding in sporadic cases of Charcot-Marie-Tooth type 1

We investigated the presence of duplication in chromosome 17p11.2 in 4 individuals with sporadic Charcot-Marie-Tooth disease (CMT 1) and 1 isolated case where a definite differential diagnosis between CMT 1 and Déjérine-Sottas disease was not achieved. The 5 affected cases and their parents and relatives were submitted to a complete clinical, neurophysiologic and genetic evaluation. A sural nerve biopsy was performed in all the isolated patients. Paternity was tested and confirmed. The presence of DNA duplication was detected in all the sporadic cases and was absent in all parents and relatives, thus confirming that a de novo dominant mutation is commonly present also in patients without a familial history and that there is a practical relevance of the genetic study in distinguishing isolated cases of CMT 1 from other forms of hereditary motor and sensory neuropathies or demyelinating neuropathies.

Impairment of central motor conduction in diabetic patients

In 70 patients with diabetes mellitus (DM) we recorded the motor evoked potentials (MEPs) following magnetic stimulation of the motor cortex and spinal roots. Central motor conduction time (CMCT) was determined as the difference between MEP latencies after cortical and spinal stimulation. The mean CMCTs for the biceps, thenar and tibialis anterior muscles were prolonged in the DM group, as compared to normal controls, and 21 patients exceeded the CMCT upper confidence limit for at least one muscle. CMCT changes and peripheral conduction velocity abnormalities occurred independently and were related to different clinical parameters. We conclude that a subclinical impairment of central motor conduction is present in 30% of DM patients, independently from the occurrence of a diabetic peripheral neuropathy and possibly reflecting different pathophysiological mechanisms.

Expression of common acute lymphoblastic leukemia antigen (CD 10) by myelinated fibers of the peripheral nervous system

The common acute lymphoblastic leukemia antigen (CALLA), CD10, is a 100-kDa surface glycoprotein endowed with neutral endopeptidase activity, shared by a number of hemopoietic and non-hemopoietic cells. In this report, immunohistochemical and Western blot techniques, using different anti-CD10 monoclonal antibodies, were utilized to demonstrate that CD10 is also expressed by myelin sheaths of the human peripheral nervous system (PNS), but not of the central nervous system. CD10-positive immunoreactivity appeared to be localized in the outer and inner borders of myelinated fibers, in nodes of Ranvier and in the Schmidt-Lantermann clefts, thus showing a distribution pattern very similar to that of myelin-associated glycoprotein (MAG). The above findings suggest that CD10 antigen, through its enzymatic activity, may have a functional role in the assembly and maintenance of PNS myelin. In addition, it is not known whether CD10, similarly to MAG, may be a target antigen in some PNS immune-mediated disorders.

Wernicke-Korsakoff Encephalopathy Following Biliopancreatic Diversion

Wernicke-Korsakoff disease with sensory-motor neuropathy was diagnosed in three out of a series of 1,663 patients (0.18%), with onset 2, 3 and 5 months after biliopancreatic diversion. Precipitating factors were vomiting, minimal food intake, anorexia, rapid weight loss, and glucose-containing intravenous feeding. Recovery was partial in two and complete in one of the patients. In the early postop, prophylactic thiamine should be given to the patients with excessively limited eating capacity. Larger doses of thiamine should be instituted parenterally either in the case of suspected Wernicke-Korsakoff encephalopathy or before starting feeding for protein malnutrition.

Charcot-Marie-Tooth (CMT) 1a duplication at 17p11.2 in Italian families

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Hereditary motor and sensory neuropathy with deafness, mental retardation and absence of large myelinated fibers

Two brothers with a presumably hereditary motor and sensory polyneuropathy (HMSN), sensory-neural hearing loss and mental retardation had clinical features and neuropathological changes in the sural nerve which may set the disorder apart from previously described types of HMSN. Consecutive sural nerve biopsies from one case showed absence of large myelinated fibers and a normal complement of small fibers. We infer from our findings that a developmental abnormality with faulty growth and subsequent axonal atrophy may be responsible.

"Pure" meningeal carcinomatosis as the autopsy-proven sole manifestation of an undetected cancer

Meningeal carcinomatosis (MC) was diagnosed in a 37-year-old woman, based on the finding of neoplastic cells in the cerebrospinal fluid. The patient had no relevant antecedent except the resection of a breast "nodule" at the age of 20. No primary cancer nor other metastases were detected, even at autopsy. Histopathology, immunocytochemistry and electron microscopy confirmed pure leptomeningeal infiltration by poorly differentiated adenoepithelial cancer. This case includes several unusual features and raises the possibility of an extremely long-lasting interval between an unrecognized primary (breast?) carcinoma and MC.

GFAP expression of human Schwann cells in tissue culture

We have studied the expression of the intermediate filament (IF) proteins, vimentin and glial fibrillary acidic protein (GFAP), in cultured human Schwann cells (SC) from patients with different neuropathies and normal control cases. SC cultures from sural nerve biopsies of 8 subjects with axonal neuropathies, 8 with demyelinating neuropathies and 3 normal controls were included in this study and processed with double immunofluorescence technique, using anti-vimentin and anti-GFAP antibodies, during the 2nd, 4th and 6th week of culture. Five cultures incubated with anti-GFAP antibodies were also processed for immunoelectron microscopy. Specificity tests of the used antibodies were performed. We have found that: (1) cultured human SC constantly express vimentin; (2) SC from normal controls are GFAP-negative in the first period of culture; (3) SC from pathologic nerves can contain GFAP-immunoreactive IF and the percentage of GFAP-positive SC is higher in axonal than in demyelinating neuropathies; (4) during the permanence in culture human SC from both normal and pathologic cases acquire the ability to synthesize GFAP. The obtained data suggest that the removal from axonal contact and the resulting loss of myelinating function induce a cytoskeletal cellular response in human SC characterized by the cytoplasmic accumulation of GFAP-immunoreactive IF.

Protective effect of cyproheptadine in a gerbil model of cerebral ischemia

The efficacy of Cyproheptadine, a serotonin antagonist, in preventing the cerebral ischemic damage was tested on experimental model of transient global cerebral ischemia in Mongolian Gerbil. The semi-quantitative histological evaluation of the severity of ischemic damage showed a protective effect of Cyproheptadine, mainly in the anterior cortical areas.

Schwann cell GFAP expression increases in axonal neuropathies

We studied the Schwann cell (SC) GFAP immunoreactivity in normal human peripheral nerves and in neuropathies of different origin. Immunofluorescence and immunocytochemistry were carried out on serial frozen sections of 58 peripheral nerve biopsies using monoclonal antibodies (mabs) antivimentin and anti GFAP, and antiserum anti S-100 and anti GFAP. To test the specificity of the mabs and antiserum used, proper competition controls on tissue sections of 2 selected cases, tissue cultures studies of human fibroblasts and immunoblotting of homogenates of human fibroblasts, 3 normal and 5 pathologic nerves were carried out. In order to evaluate a possible correlation between SC GFAP positivity and neuropathologic findings a quantitative study was performed, evaluating the SC GFAP reactivity in all the 58 cases, and relating the SC GFAP positivity to the index of nerve pathology (IP) in 9 selected cases, and to the percentage of teased fibers showing axonal degeneration or demyelination and remyelination in 25 representative cases. We demonstrate that in normal human sural nerves and in demyelinating neuropathies only a few scattered SC are recognized by the mabs or antiserum anti GFAP. On the contrary in axonal neuropathies the majority of SC gain the property to express intermediate filaments which show common antigenic properties with GFAP.

[Accuracy of distribution of the doses obtained with electron beams of irregular shape and in the presence of inhomogeneous structures]

The authors have addressed the problem of dose distribution calculation accuracy when irregularly shaped electron beams are used and structural dishomogeneities are present. The mathematical model used for the electrons from the "scattering foil" and from the colimator walls is the "gaussian pencil beam", and the total dose is obtained by adding to the above mentioned components the dose from the electrons diffused by the field defining frame and from bremsstrahlung photons. Depth dose curves, with and without frames, are compared with a satisfactory correspondence between the calculated and the measured curves. The calculation method is considered accurate within 2% of dose and 2 mm in position. When dishomogeneous structures are present and treated as semi-infinite layers, corrections are referred in 2-D to a single anatomical section and can be extended to 3-D if a sufficient number of sections is available for the whole volume definition. However current algorithms need to be improved when there is the possibility to use a much more powerful hardware.

Class II antigen expression on human cultured Schwann cells from patients with Charcot-Marie-Tooth disease

T lymphocytes control the extent of the immune reaction by recognizing the antigen in connection with class II histocompatibility surface molecules, coded by genes located on the HLA-D locus. The expression of HLA-DR antigens is confined to a few antigen presenting cells, like lymphocytes and macrophages, which can therefore induce the initial phase of the immune reaction. We report that also Schwann cells (SC) from patients with Charcot-Marie-Tooth disease (CMT), an hereditary disorder of the peripheral nervous system, are able to express HLA-DR antigens. Human SC cultures were carried out from sural nerve biopsies of CMT and normal control cases. Cultures were tested on day 7, 14, 21 and 28, with double immunofluorescence technique using rabbit antiserum anti-S-100 and mouse anti-HLA-DR monoclonal antibody. SC from CMT were HLA-DR positive since the first few days, continuing to express class II antigens for all the duration of the culture. The presence of class II antigens on cultured SC from CMT disease suggests that immune-mediated mechanisms may be relevant in the pathogenesis of this degenerative disorder of the peripheral nervous system.

Amyloid neuropathy in light chain multiple myeloma

We describe a 73-year-old man with peripheral neuropathy and light chain lambda-type myeloma. A sural nerve biopsy showed the typical neuropathological picture of amyloid neuropathy. With the present case we first demonstrate amyloid deposits in peripheral nerves during light chain multiple myeloma and stress the importance of amyloidosis in the development of peripheral neuropathy.

[Hereditary sensory motor neuropathy: degenerative disease or a disease with an immune-mediated pathogenesis?]

The clinical data proving that some hereditary motor-sensory neuropathies (HMSN type 1) are steroid sensitive may indicate inflammatory or immunomediated mechanisms as cofactors contributing to the clinical course of these disorders. The finding of HLA-DR positivity of Schwann cells in HMSN type I along with the presence in some cases of inflammatory infiltrates in nerve sections provides further evidence for this hypothesis.

Anti-lymphocyte globulin stimulates normal human T cells to proliferate and to release lymphokines in vitro. A study at the clonal level

Human peripheral blood mononuclear cells (PBMC) were stimulated in vitro with anti-lymphocyte globulin (ALG), and the phenotypic and functional properties of the blasts obtained were investigated. When stained with monoclonal antibodies (MoAbs), all of the blasts were identified as T cells that expressed predominantly the CD4 phenotype (70% of the cells). The remaining blasts were CD8+. These findings demonstrate that ALG stimulates both helper-inducer and cytotoxic-suppressor cells at random since the CD4 to CD8 ratio in the stimulated blasts was the same as in resting PBMC. This ratio is different from that observed in short-term cultures of T cells stimulated with phytohemagglutinin (PHA) under the same conditions (CD4 to CD8 ratio less than 1). ALG-stimulated T cells were cloned by limiting dilution in the presence of recombinant Interleukin-2 (rIL-2). The clones obtained were expanded and maintained in long term cultures with rIL-2. Thirty-two clones were tested for their capacity of producing colony stimulating activity (CSA) or burst promoting activity (BPA). Twenty-eight of them produced CSA and 12 produced BPA. No correlation was found between the surface phenotype and the ability of the clones to produce CSA or BPA (ie, both the CD4+ and CD8+ clones released the cytokines). When 16 of the same clones were tested for II-2 and gamma interferon (gamma IFN) production, 12 were found to be gamma INF and IL-2 producers. All of the gamma IFN producers also released IL-2, whereas in the single clones no correlation was found with the capacity of releasing BPA and CSA. Supernatants from selected T-cell clones were also tested for hematopoietic growth factor activities in the presence of neutralizing antisera to human granulocyte-macrophage colony stimulating factor (GM-CSF) or to Interleukin-3 (IL-3). It was found that most CSA was attributable to GM-CSF, whereas BPA was mainly related to the presence of IL-3.

HLA-DR Schwann cell reactivity in peripheral neuropathies of different origins

HLA-DR antigens have been found on Schwann cells in peripheral neuropathies of different origins but not in normal control cases. Class II antigen reactivity was more intense in chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and hereditary motor and sensory neuropathy type 1 (HMSN), but was also observed in toxic or metabolic neuropathies. The expression of HLA-DR antigen on Schwann cells does not appear to be related to the inflammatory or autoimmune origin of the disease.

Direct immunofluorescence in sural nerve biopsies

Direct immunofluorescence (DIF) has been carried out in 66 sural nerve biopsies using antibodies against human IgG, IgA, IgM, C3, C4, albumin, fibrinogen, and kappa- and lambda-chains. In 37 out of 63 (59%) different neuropathies immunoglobulins or other plasma proteins were found within the peripheral nerves. IgM along the myelin sheaths were found in monoclonal IgM-K-associated demyelinating peripheral neuropathy and chronic inflammatory demyelinating peripheral neuropathy. IgM within the perineurium were detected in hereditary, diabetic, paraneoplastic, paraproteinemic and neuropathies of unknown cause. In inflammatory, vasculitic, hereditary and toxic neuropathies fibrinogen, albumin, IgG and IgA were variably observed in endoneurium, endoneurial vessels, perineurium and epineurial vessels. In our experience DIF appears to be just an unspecific marker of sural nerve pathology. In selected cases however DIF may be helpful in the diagnosis or in better understanding the pathogenetic mechanisms of the disease.

Cerebrospinal fluid and neuropathological study in Devic's syndrome. Evidence of intrathecal immune activation

Cerebrospinal fluid (CSF) was studied in 2 cases of Devic's syndrome (DS). In one of these cases autopsy was carried out. The main CSF feature in DS is the association of blood-brain barrier damage and intrathecal IgG synthesis. These findings are in keeping with our neuropathological observation of diffuse central nervous system vasculitis and leptomeningitis. As a whole, our CSF and neuropathological findings in DS are consistently different from those in multiple sclerosis.

Peripheral neuropathy in Cockayne syndrome

Two siblings with Cockayne syndrome are reported. In one case a sural nerve biopsy showed a demyelinating peripheral neuropathy with occasional inclusions in Schwann cells made up of electron dense finely granular material intermingled with vacuoles or lamellar structures. The significance, if any, of this accumulated material remains unclear. The presence, in addition, of small finely lamellar intra-axonal osmiophilic bodies suggests an associated axonal involvement.

Experimental studies on peripheral nerve repair following early or delayed suture

Early suture of the sciatic nerve in rats was compared with delayed suture performed after 2 weeks. The distal tract of the nerve was studied morphologically using semifine sections and computerised measurements of the number and diameters of regenerated fibres, and electrophysiologically by the measurement of nerve velocity conduction. The morphological examination did not reveal any substantial difference, while the velocity conduction tests showed better reinnervation following early suture.

Italian multicenter study of dementia: a pathologically verified case of Alzheimer disease

The pathological findings in a case included in the Italian multicenter study of dementia on clinical grounds are reported. The histological and ultrastructural examination confirms the diagnosis of Alzheimer disease, evidence for the validity of the clinical protocol.

Congenital dyserythropoietic anemia type I: report of a pair of siblings

Two siblings affected with congenital dyserythropoietic anemia type I are described. They are the sixth familial occurrence reported. Particularly interesting is the comparison between the course and laboratory data of our cases. An unusual finding is the presence of the antigen 'i' on the erythrocytes of both patients.

Complete bilateral relapsing ophthalmoplegia in a diabetic patient with a sensory-motor distal polyneuropathy

The clinicopathological study of a case of relapsing complete bilateral external ophthalmoplegia associated with a sensory-motor polyneuropathy is presented. No other causes apart from diabetes mellitus were ascertained. The sural biopsy demonstrated an axonal as well as demyelinating neuropathy. The physiopathology of the rare cases of diabetic multiple bilateral cranial nerve palsies is discussed.

Polyglucosan bodies in the sural nerve of a diabetic patient with polyneuropathy

In the sural nerve of a 62-year-old woman with impaired glucose tolerance test and polyneuropathy, many intra-axonal polyglucosan bodies were observed. Polyglucosan bodies have been described in spontaneously or alloxan-diabetic rats, but are not usually observed in human diabetic neuropathy. Since intra-axonal polyglucosan bodies can occur in the sural nerve in various diseases and in aging, they are considered as non-specific changes. Their presence is probably related to a primary axonal neuropathy.

A quantitative and ultrastructural study of substantia nigra and nucleus centralis superior in Alzheimer's disease

In four patients with presenile Alzheimer's disease (AD) and three age-matched controls a quantitative study of neurons and neurofibrillary tangles (NFT) in the substantia nigra (SN) and nucleus centralis superior (NCS) was performed. A significant neuronal loss, similar in both nuclei, was found in AD cases, while the incidence of NFT was remarkably higher in NCS. Moreover, no significant correlation between neuronal loss and number of NFT was detected. An electron-microscopic study revealed that the subcortical NFT in NCS are made up of paired helical filaments in spite of their globose round shape.

Bannwarth syndrome: report of two cases

Report of two cases of Bannwarth syndrome, an apparently neglected condition both in the Italian and in the English literature.