101
|
Abstract
Peripheral neuropathy has emerged as the most common neurologic complication of human immunodeficiency virus (HIV) infection. It will continue to play an Important role in HIV Infection given the fact that HIV-infected Individuals are living longer, are at risk of long-term metabolic complications, and face an Increasing exposure to potentially neurotoxic antiretroviral drugs. We review the various types of peripheral neuropathy that have been associated with HIV infection, including distal symmetrical polyneuropathy, toxic neuropathy from antiretroviral drugs, diffuse infiltrative lymphocytosis syndrome, inflammatory demyelinating polyneuropathies, multifocal mononeuropathies, and progressive polyradiculopathy.
Collapse
Affiliation(s)
- Sergio Ferrari
- Department of Neurological and Visual Sciences, Section of Neurology, University of Verona, Verona, Italy
| | | | | | | | | | | | | |
Collapse
|
102
|
De Angelis MV, Di Muzio A, Capasso M, Angiari C, Cavallaro T, Fabrizi GM, Rizzuto N, Uncini A. Segmental conduction abnormalities and myelin thickenings in Val102/fs null mutation of MPZ gene. Neurology 2004; 63:2180-3. [PMID: 15596778 DOI: 10.1212/01.wnl.0000145707.17402.1d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors report in patients with Val102/fs null mutation a possibly age dependent variability of clinical and electrophysiologic phenotype, segmental conduction abnormalities mainly in ulnar nerves at the elbow, and excessive myelin foldings and thickenings. The authors hypothesize that myelin thickenings at the paranodal region, in concurrence with compression at usual entrapment sites or minor repetitive trauma, may induce segmental conduction abnormalities.
Collapse
Affiliation(s)
- M V De Angelis
- Neurodegenerative Diseases Unit, Aging Research Center, Ce.S.I., G d'Annunzio University Foundation Chieti-Pescara, Chieti, Italy
| | | | | | | | | | | | | | | |
Collapse
|
103
|
Rampello L, Cerasa S, Alvano A, Buttà V, Raffaele R, Vecchio I, Cavallaro T, Cimino E, Incognito T, Nicoletti F. Dementia with Lewy bodies: a review. Arch Gerontol Geriatr 2004; 39:1-14. [PMID: 15158576 DOI: 10.1016/j.archger.2003.11.003] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2003] [Revised: 11/26/2003] [Accepted: 11/28/2003] [Indexed: 02/04/2023]
Abstract
The dementia with Lewy bodies (DLB) is the second major type of senile, degenerative dementia, after the Alzheimer disease (AD). It is characterized by the presence of cytoplasmic inclusions of alpha-synuclein in the cerebral cortex and in the nuclei of the brain stem. DLB patients frequently have complex visual hallucinations, depressive symptoms, Parkinsonian manifestations and cognitive deficits, showing important associations with the Parkinson disease and the AD. The DLB should be differentiated from atypical Parkinsonisms, but the differential diagnosis often remains difficult and unsafe. Clinical and neuropathological findings, as well as neuroimaging are valuable tools in establishing specific diagnosis of DLB. Acetylcholinesterase inhibitors, dopamine-agonists, benzodiazepines of short or medium half-life, and antidepressants may be useful in the treatment of DLB, depending on the dominant symptoms of the given patients.
Collapse
Affiliation(s)
- L Rampello
- Department of Neurosciences, University of Catania, Azienda Policlinico-Neurologia, Via S. Sofia, 78, Catania I-95125, Italy.
| | | | | | | | | | | | | | | | | | | |
Collapse
|
104
|
Frigerio R, Fabrizi GM, Ferrarini M, Cavallaro T, Brighina L, Santoro P, Agostoni E, Cavaletti G, Rizzuto N, Ferrarese C. An unusual transthyretin gene missense mutation (TTR Phe33Val) linked to familial amyloidotic polyneuropathy. Amyloid 2004; 11:121-4. [PMID: 15478468 DOI: 10.1080/13506120410001727767] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Familial amyloidotic polyneuropathy is a rare autosomal dominant disease, with clinical symptoms beginning in most kindreds within the third to seventh decades of life. The primary defect results from one of a number of mutations in the transthyretin (TTR) gene. Over 80 mutations in the TTR gene have been described. Most mutations give rise to adult onset progressive peripheral and autonomic neuropathy, due to amyloid deposition within the nerves, and often subclinical cardiac amyloid and vitreous deposits. We report here the clinical and molecular characterization of a rare TTR missense mutation discovered in a young woman from Macedonia, showing severe axonal sensory-motor polyneuropathy, restrictive cardiomyopathy and bilateral vitreous deposits. The transthyretin gene, analyzed by direct nucleotide sequencing, demonstrated a T to G transversion at nucleotide 183 in the exon 2 which is predicted to cause a heterozygous valine for phenylalanine substitution at codon 33 (TTR Phe33Val). This mutation has been previously reported only twice, without complete clinical descriptions.
Collapse
Affiliation(s)
- Roberta Frigerio
- Department of Neuroscience and Biomedical Technologies, University of Milano-Bicocca, Monza, Italy
| | | | | | | | | | | | | | | | | | | |
Collapse
|
105
|
Cavallaro T, Fabrizi GM, Angiari C, Lus G, Cabrini I, Cotrufo R, Rizzuto N. Are giant axons a pathological marker of charcot-marie-tooth neuropathy type 2E? J Peripher Nerv Syst 2004. [DOI: 10.1111/j.1085-9489.2004.009209bm.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
106
|
Angiari C, Ferrarini M, Taioli F, Cavallaro T, Fabrizi GM, Rizzuto N. Charcot-marie-tooth disease type 1: novel cases and novel mutations detected by DHPLC. J Peripher Nerv Syst 2004. [DOI: 10.1111/j.1085-9489.2004.009209bh.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
107
|
Ferrari S, Cavallaro T, Lanzafame M, Malena M, Rizzuto N. Painful neuropathy vasculitis in HIV infection. J Peripher Nerv Syst 2004. [DOI: 10.1111/j.1085-9489.2004.009209bl.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
108
|
De Angelis MV, Capasso M, Anghiari C, Cavallaro T, Di Muzio A, Fabrizi GM, Uncini A. Myelin thickenings in val 102/fs null mutation of MPZ gene. J Peripher Nerv Syst 2004. [DOI: 10.1111/j.1085-9489.2004.009209bd.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
109
|
Fabrizi GM, Cavallaro T, Angiari C, Bertolasi L, Cabrini I, Ferrarini M, Rizzuto N. Giant axon and neurofilament accumulation in Charcot-Marie-Tooth disease type 2E. Neurology 2004; 62:1429-31. [PMID: 15111691 DOI: 10.1212/01.wnl.0000120664.07186.3c] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The axonal type 2 Charcot-Marie-Tooth disease (CMT2) is phenotypically poorly characterized. Here the authors report a family with a Pro22Ser mutation in the neurofilament-light gene (NF-L; CMT2E) manifesting electrophysiologically as the demyelinating type 1 CMT (CMT1) and pathologically as an axonopathy with giant axons and accumulation of disorganized NF. NF-L should be investigated in CMT2 as well as in CMT1 not associated with the usual genes PMP22, Cx32, and P0.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy.
| | | | | | | | | | | | | |
Collapse
|
110
|
Lus G, Nelis E, Jordanova A, Löfgren A, Cavallaro T, Ammendola A, Melone MAB, Rizzuto N, Timmerman V, Cotrufo R, De Jonghe P. Charcot-Marie-Tooth disease with giant axons: a clinicopathological and genetic entity. Neurology 2004; 61:988-90. [PMID: 14557576 DOI: 10.1212/wnl.61.7.988] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The authors report an Italian family with autosomal-dominant Charcot-Marie-Tooth disease (CMT) in which there were giant axons in the sural nerve biopsy. Linkage to the known CMT2 loci (CMT2A, CMT2B, CMT2D, CMT2F) and mutations in the known CMT2 genes (Cx32, MPZ, NEFL), GAN, NEFM, and CMT1A duplication/HNPP deletion were excluded. This family with CMT and giant axons has a pathologic and genetic entity distinct from classic CMT.
Collapse
Affiliation(s)
- G Lus
- Department of Neurological Sciences, First Division of Clinical Neurology, Faculty of Medicine, Second University of Naples and Interuniversity Center for Research in Neuroscience, Naples, Italy.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
111
|
Capasso M, Di Muzio A, Ferrarini M, De Angelis MV, Caporale CM, Lupo S, Cavallaro T, Fabrizi GM, Uncini A. Inter-nerves and intra-nerve conduction heterogeneity in CMTX with Arg(15)Gln mutation. Clin Neurophysiol 2004; 115:64-70. [PMID: 14706470 DOI: 10.1016/j.clinph.2003.08.024] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
OBJECTIVE In X-linked Charcot-Marie-Tooth disease (CMTX), electrophysiological and histopathological studies have suggested either a demyelinating or an axonal polyneuropathy. We report a CMTX family with a striking heterogeneity of nerve conductions between and within nerves. METHODS Two men and one woman have been studied by conduction velocities, sural nerve biopsy with morphometry (one man) and DNA analysis. RESULTS In both men motor conduction velocities were slowed in the demyelinating range, conduction velocity differences among nerves in the same subject varied from 13 to 24 m/s, and distal median compound muscle action potential (CMAP) amplitudes were 3-5 times reduced compared to ulnar CMAPs. Abnormal area reduction or excessive temporal dispersion of proximal CMAP was present in at least two nerves in all patients. Sural nerve biopsy showed reduction of large myelinated fibres, cluster formations, occasional onion bulbs. Teased fibres study revealed short internodes for fibre diameter, enlarged Ranvier nodes but no evidence of segmental demyelination and remyelination. DNA analysis showed an Arg(15)Gln mutation in connexin32 gene in all patients. CONCLUSIONS In this family conduction slowing and segmental conduction abnormalities, in absence of morphological evidence of de-remyelination, may be related to short internodes, widened Ranvier nodes and the specific effect of the mutation. The occurrence in some CMTX patients of a non uniform involvement between and within nerves, as in acquired demyelinating neuropathies, should be kept in mind to avoid misdiagnoses.
Collapse
Affiliation(s)
- M Capasso
- Neurodegenerative Diseases Unit, Institute of Aging, University G. d'Annunzio, Ospedale SS. Annunziata, Via dei Vestini, I-66013 Chieti, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
112
|
Salvi F, Scaglione C, Michelucci R, Linke RP, Obici L, Ravani A, Rimessi P, Ferlini A, Meletti S, Cavallaro T, Tassinari CA, Martinelli P. Atypical familial motor neuropathy in patients with mutant TTR Ile68Leu. Amyloid 2003; 10:185-9. [PMID: 14640031 DOI: 10.3109/13506120308998999] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Two sisters from an Italian family shared progressive motor symptoms, preceding the onset of sensory and autonomic disturbances. The familial occurrence of axonal and slowly progressive polyneuropathy led us to consider these patients as candidates for TTR molecular analysis. We found a missense mutation causing Ile68Leu TTR substitution in both. The aims of this work are to report the possibility of a motor onset of amyloid polyneuropathy and to suggest the search for TTR mutations in familial cases of axonal polyneuropathy. Second, to stress the possible occurrence of amyloid within the spinal canal as the potential pathogenesis and responsible for motor presentation.
Collapse
Affiliation(s)
- F Salvi
- Dipartimento di Scienze Neurologiche, Ospedale Bellaria, Via Altura 3, 40139 Bologna, Italy.
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
113
|
Sparaco M, Simonati A, Cavallaro T, Bartolomei L, Grauso M, Piscioli F, Morelli L, Rizzuto N. MELAS: clinical phenotype and morphological brain abnormalities. Acta Neuropathol 2003; 106:202-12. [PMID: 12910360 DOI: 10.1007/s00401-003-0716-z] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2002] [Revised: 01/28/2003] [Accepted: 04/03/2003] [Indexed: 10/26/2022]
Abstract
We describe the clinical and neuropathological findings of three unrelated autopsy cases of MELAS harboring the A3243G transition in the mitochondrial DNA (mtDNA). Using immunohistochemical techniques, we studied the expression of several subunits of the respiratory chain in various brain regions from the same cases. In all three cases there was a reduced immunocytochemical staining for mtDNA-encoded subunits of the respiratory chain, confirming the presence of a defective mitochondrial protein synthesis in this disease. Mitochondrial abnormalities were mostly confined to multiple areas of different size and shape, in agreement with the focal character of the brain pathology in MELAS, and were most prominent in the cerebral cortex, providing a morphological contribution to the explanation of the cognitive regression of the patients. Immunoreactivity for mtDNA-encoded subunits was reduced in the walls of many pial and intracerebral arterioles of different brain regions but there was no clear correlation between territories of affected vessels and distribution of the histological and immunohistochemical lesions. Cerebral focal lesions in MELAS might have a metabolic nature and several pathogenetic mechanisms might be involved in the genesis of stroke-like episodes when there is a local increased ATP demand.
Collapse
Affiliation(s)
- M Sparaco
- UO di Neurologia con SU, Azienda Ospedaliera, Benevento, Italy
| | | | | | | | | | | | | | | |
Collapse
|
114
|
Del Colle R, Fabrizi GM, Turazzini M, Cavallaro T, Silvestri M, Rizzuto N. Hereditary neuropathy with liability to pressure palsies: electrophysiological and genetic study of a family with carpal tunnel syndrome as only clinical manifestation. Neurol Sci 2003; 24:57-60. [PMID: 12827539 DOI: 10.1007/s100720300072] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Hereditary neuropathy with liability to pressure palsies (HNPP) is an autosomal dominant disease characterized by recurrent sensory or motor manifestations. The molecular basis of HNPP is a deletion on chromosome 17p11.2. We studied a family (father, 61 years; mother, 55 years; 6 children of mean age 25.3 years) showing symptoms of carpal tunnel syndrome in 4 members (the parents and 2 sons). No one of them reported episodes of nerve palsy. In all the patients, except the mother and the younger son, electrophysiologic evaluation showed a sensorimotor polyneuropathy with delayed sensorimotor latencies. Genetic analysis was carried out in the parents and the eldest son. The 17p11.2 deletion was detected in the father and son, indicating paternal transmission of the disease. Clinical manifestations of HNPP may be atypical. Sometimes there is no history of acute nerve palsy, as in this family. For this reason, the frequence of HNPP might be underestimated. Electrophysiological examination is of great importance for the diagnosis of HNPP. Genetic analysis is a rapid and reliable diagnostic tool that can be combined with simplified electrophysiological examination, avoiding the need for nerve biopsy. In conclusion, the diagnosis of HNPP should be invoked in early onset entrapment neuropathies.
Collapse
Affiliation(s)
- R Del Colle
- Department of Neurology, Legnago Hospital, Via Gianella 1, I-37045 Legnago (VR), Italy
| | | | | | | | | | | |
Collapse
|
115
|
Zanusso G, Ferrari S, Cardone F, Zampieri P, Gelati M, Fiorini M, Farinazzo A, Gardiman M, Cavallaro T, Bentivoglio M, Righetti PG, Pocchiari M, Rizzuto N, Monaco S. Detection of pathologic prion protein in the olfactory epithelium in sporadic Creutzfeldt-Jakob disease. N Engl J Med 2003; 348:711-9. [PMID: 12594315 DOI: 10.1056/nejmoa022043] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
BACKGROUND Olfactory cortexes and the olfactory tracts are involved in sporadic Creutzfeldt-Jakob disease. We examined peripheral regions of the olfactory sensory pathway, including the olfactory mucosa, to assess whether pathologic infectious prion protein (PrPSc) is deposited in the epithelium lining the nasal cavity. METHODS We studied nine patients with neuropathologically confirmed sporadic Creutzfeldt-Jakob disease. We obtained the brain, the cribriform plate with the attached olfactory mucosa, and the surrounding respiratory epithelium at autopsy. Control samples of nasal mucosa were obtained post mortem or at biopsy from age-matched control subjects and from control patients with other neurodegenerative diseases. The olfactory and respiratory mucosa and the intracranial olfactory system were analyzed by light microscopy, immunohistochemistry, and Western blotting for pathological changes and for deposition of PrPSc. RESULTS In all nine patients with sporadic Creutzfeldt-Jakob disease, PrPSc was found in the olfactory cilia and central olfactory pathway but not in the respiratory mucosa. No PrPSc was detected in any of the tissue samples from the 11 controls. CONCLUSIONS Our pathological and biochemical studies show that PrPSc is deposited in the neuroepithelium of the olfactory mucosa in patients with sporadic Creutzfeldt-Jakob disease, indicating that olfactory biopsy may provide diagnostic information in living patients. The olfactory pathway may represent a route of infection and a means of spreading prions.
Collapse
Affiliation(s)
- Gianluigi Zanusso
- Department of Neurologic and Visual Sciences, University of Verona, Verona, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
116
|
Massa R, Palumbo C, Cavallaro T, Panico MB, Di Muzio A, Bei R, Terracciano C, Rizzuto N, Bernardi G, Modesti A. Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 69. J Peripher Nerv Syst 2003. [DOI: 10.1046/j.1529-8027.2003.00069.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
117
|
Bossi B, Ardolino G, Fabrizi GM, Bertolasi L, Cavallaro T, Polo S, Barbieri S, Rizzuto N, Priori A. Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 42. J Peripher Nerv Syst 2003. [DOI: 10.1046/j.1529-8027.2003.00042.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
118
|
Angiari C, Fabrizi GM, Cavallaro T, Ferrarini M, Cabrini I, Simonati A, Rizzuto N. Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 50. J Peripher Nerv Syst 2003. [DOI: 10.1046/j.1529-8027.2003.00050.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
119
|
Cimini N, Ferracci F, Macrì E, Cavallaro T, Moretto G. Abstracts of the 8th Meeting of the Italian Peripheral Nerve Study Group: 28. J Peripher Nerv Syst 2003. [DOI: 10.1046/j.1529-8027.2003.00028.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
120
|
Capasso M, Di Muzio A, Cavallaro T, Taioli F, Fabrizi G, Uncini A. NON-UNIFORM CONDUCTION SLOWING IN X-LINKED DOMINANT CHARCOT-MARIE-TOOTH DISEASE (CMTX). J Peripher Nerv Syst 2002. [DOI: 10.1046/j.1529-8027.2002.7011_8.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
|
121
|
Fabrizi GM, Ferrarini M, Cavallaro T, Taioli F, Polo A, Jarre L, Rizzuto N. Gonosomal Mosaicism Of A Novel Heterozygous Mutation Of P Causes Charcot‐Marie‐Tooth Neuropathy Type 1b With Apparent Autosomal Recessive Inheritance. J Peripher Nerv Syst 2001. [DOI: 10.1046/j.1529-8027.2001.01007-22.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- GM Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - M Ferrarini
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - T Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - F Taioli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - A Polo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - L Jarre
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - N. Rizzuto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| |
Collapse
|
122
|
Agazzi P, Polo A, Ferrari S, Cavallaro T, Rizzuto N, Nardelli E. A Case Of Paraneoplastic Neuropathy (PN) And Anti‐Glycolipid Antibodies (GLA). J Peripher Nerv Syst 2001. [DOI: 10.1046/j.1529-8027.2001.006001040.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- P Agazzi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| | - A Polo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| | - S Ferrari
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| | - T Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| | - N Rizzuto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| | - E. Nardelli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona
| |
Collapse
|
123
|
Fabrizi GM, Ferrarini M, Cavallaro T, Jarre L, Polo A, Rizzuto N. A somatic and germline mosaic mutation in MPZ/P(0) mimics recessive inheritance of CMT1B. Neurology 2001; 57:101-5. [PMID: 11445635 DOI: 10.1212/wnl.57.1.101] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To identify the molecular basis of a demyelinating Charcot-Marie-Tooth disease type 1 (CMT1) with presumed autosomal recessive inheritance. BACKGROUND CMT1, an inherited motor and sensory neuropathy with low nerve conduction velocities, is caused by dominantly inherited mutations in the genes of the peripheral myelin protein 22 (PMP22), myelin protein zero (MPZ/P(0)), and early growth response 2 transcription factor (EGR2/Krox-20). PATIENTS AND METHODS Two young sisters born of clinically and electrophysiologically healthy parents had a severe CMT1 neuropathy of presumed autosomal recessive inheritance. The older sister underwent a nerve biopsy. The authors analyzed PMP22, MPZ/P(0), and EGR2/Krox-20 by automated direct nucleotide sequencing. For rapid mutation detection, they determined the restriction-fragment-length polymorphisms for TaqI in the fluorescein-labeled target DNA sequence amplified by PCR. RESULTS Nerve biopsy disclosed a demyelinating and remyelinating neuropathy with onion bulb formations. Both sisters had a novel heterozygous G308-->A transition of MPZ/P(0) without any mutation of PMP22 or EGR2/Krox-20. The G308-->A transition was a nonconservative mutation that changed a glycine into a glutamate at the amino acid residue 74 in the extracellular domain of the mature MPZ/P(0). None of 50 healthy controls had the mutation. The healthy mother had a low amount of the mutation in blood (congruent with 20%) as well as in skin, buccal epithelium, and hairs (30%). Because the healthy mother carried clones of somatic mutant cells and had transmitted the G308-->A transition to the affected daughters, she also harbored germline mutant cells. CONCLUSION In hereditary demyelinating neuropathies, somatic and germline mosaicism of dominant mutations in the myelin protein genes may mimic autosomal recessive inheritance.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy.
| | | | | | | | | | | |
Collapse
|
124
|
Ferrarini M, Fabrizi GM, Nardelli E, Polo A, Zanette GP, Cavallaro T, Rizzuto N. The PHE64LEU Variant Of
TTR
Is Associated With A Late‐Onset Form Of Familial Amyloidotic Polyneuropathy Dominated By Motor Involvement. J Peripher Nerv Syst 2001. [DOI: 10.1046/j.1529-8027.2001.01007-24.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- M Ferrarini
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - GM Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - E Nardelli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - A Polo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - GP Zanette
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - T Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| | - N. Rizzuto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Italy
| |
Collapse
|
125
|
Fabrizi GM, Simonati A, Taioli F, Cavallaro T, Ferrarini M, Rigatelli F, Pini A, Mostacciuolo ML, Rizzuto N. PMP22 related congenital hypomyelination neuropathy. J Neurol Neurosurg Psychiatry 2001; 70:123-6. [PMID: 11118262 PMCID: PMC1763468 DOI: 10.1136/jnnp.70.1.123] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
The peripheral myelin protein 22 (PMP22) is a tetraspan membrane protein which is localised in the compact myelin of the peripheral nerves. In fibroblasts, where it was originally identified as growth arrest related factor 3 (Gas3), PMP22 has been shown to modulate cell proliferation; in the peripheral nervous system its roles are still debated. The duplication of PMP22 is the most common cause of the demyelinating form of the autosomal dominant Charcot-Marie-Tooth neuropathy (CMT1A); rarer missense mutations of PMP22 also cause CMT1A or severe dehypomyelinating neuropathies of infancy grouped under the heading of Dejerine-Sottas syndrome (DSS). Here, a sporadic patient affected with DSS is described; nerve biopsy disclosed a picture of hypomyelination/amyelination with basal laminae onion bulbs and no florid demyelination and it was consistent with congenital hypomyelination neuropathy (CHN); molecular analysis disclosed a novel point mutation of PMP22 that causes a non-conservative arginine for cysteine substitution at codon 109, in the third transmembrane domain. CHN is the rarest and severest form of DSS and it is thought to reflect dysmyelination rather than demyelination. The reported case suggests that missense point mutations may alter a putative role of PMP22 in modulating Schwann cell growth and differentiation.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Policlinico Giambattista Rossi, via delle Menegone 10, 37134 Verona, Italy.
| | | | | | | | | | | | | | | | | |
Collapse
|
126
|
Fabrizi GM, Taioli F, Cavallaro T, Rigatelli F, Simonati A, Mariani G, Perrone P, Rizzuto N. Focally folded myelin in Charcot-Marie-Tooth neuropathy type 1B with Ser49Leu in the myelin protein zero. Acta Neuropathol 2000; 100:299-304. [PMID: 10965800 DOI: 10.1007/s004019900175] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Charcot-Marie-Tooth disease type 1 B (CMT1B) is a demyelinating neuropathy caused by mutations in the myelin protein zero (P0) gene (MPZ). A few cases of CMT1B were recently found to be characterized by focally folded myelin sheaths in nerve biopsy specimens; the significance of this association is unknown. Here, we describe two unrelated pedigrees harboring a heterozygous Ser49Leu substitution in P0ex. In both pedigrees, the mutation caused a late-onset, relatively mild CMT1B; in one pedigree, two patients had atrophy of peroneal muscles but hypertrophy of the gastrocnemius muscles. The sural nerve biopsy performed in the two index cases revealed an identical chronic demyelinating and remyelinating neuropathy dominated by focal foldings of the myelin sheath shaped either as tomacula or as out/infoldings. The report adds Ser49Leu to the mutations of P0ex associated with focally folded myelin and provides strong evidence that such a structural alteration of the myelin sheath reflects a distinct pathogenetic mechanism in a subgroup of CMT1B.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, University of Verona, Policlinico Giambattista Rossi, Italy
| | | | | | | | | | | | | | | |
Collapse
|
127
|
Sparaco M, Cavallaro T, Rossi G, Rizzuto N. Immunohistochemical demonstration of spinal ventral horn cells involvement in a case of "myoclonus epilepsy with ragged red fibers" (MERRF). Clin Neuropathol 2000; 19:200-7. [PMID: 10919352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
OBJECTIVE To detect mitochondrial lesions in the spinal cord from an autoptic case of myoclonus epilepsy with ragged-red fibers (MERRF) that harbored the A8344G mutation and was deemed to be free of pathological abnormalities in the spinal cord after conventional post-mortem examination. MATERIALS AND METHODS Antibodies against subunits of complex III and IV of the respiratory chain were used to perform immunohistochemical analysis on cervical, thoracic and lumbar sections of the spinal cord from the case of MERRF and from controls. Immunostaining was carried out by the avidin-biotin peroxidase complex (ABC) method. RESULTS A selective decreased expression of subunit II of cytochrome c oxidase (COX-II) was found in all spinal cord sections from the patient. CONCLUSIONS The immunohistochemical demonstration of mitochondrial lesions in the spinal ventral horn cells from this case with MERRF seems to be consistent with the results of many genetic studies pointing to a high and homogeneous distribution of mutant mtDNA in different neuronal populations of patients with this disease. The use of these immunological probes in the study of mitochondrial encephalomyopathies can increase both the resolution and the specificity of morphological observations in the central nervous system (CNS).
Collapse
Affiliation(s)
- M Sparaco
- U.O. di Neurologia e Neuroriabilitazione, Ospedale S. Maria del Carmine, Rovereto, Italy
| | | | | | | |
Collapse
|
128
|
Polo A, Aldegheri R, Bongiovanni LG, Cavallaro T, Rizzuto N. Painless fractures and thermoregulation disturbances in sensory-autonomic neuropathy: electrophysiological abnormalities and sural nerve biopsy. Neuropediatrics 2000; 31:148-50. [PMID: 10963103 DOI: 10.1055/s-2000-7488] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
We describe the case of a young girl suffering from thermoregulation disturbances, painless fractures and arthropathy since early childhood. The patient was diagnosed as having a hereditary sensory autonomic neuropathy. Although needle EMG, conventional nerve conduction studies and somatosensory evoked potentials gave normal results, sympathetic skin responses (SSRs) were absent. Sural nerve biopsy showed a substantial reduction in the number of small myelinated and unmyelinated fibers. We emphasize the importance of SSR testing in revealing a condition which is otherwise difficult to identify by electrophysiological techniques. The combined evidence of functional and morphological findings is strongly suggestive of selective peripheral nerve involvement.
Collapse
Affiliation(s)
- A Polo
- Dipartimento di Scienze Neurologiche e della Visione, Policlinico Borgo Roma, Verona, Italy
| | | | | | | | | |
Collapse
|
129
|
Rigatelli F, Fabrizi G, Simonati A, Cavallaro T, Ferrarini M, Taioli F, Mostacciuolo M, Rizzuto N. CONGENITAL HYPOMYELINATION NEUROPATHY WITH A NOVEL MUTATION OF PMP22. J Peripher Nerv Syst 2000. [DOI: 10.1046/j.1529-8027.2000.00513-51.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- F. Rigatelli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - G.M. Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - A. Simonati
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - T. Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - M. Ferrarini
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - F. Taioli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - M.L. Mostacciuolo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - N. Rizzuto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| |
Collapse
|
130
|
Fabrizi G, Polo A, Cavallaro T, Pinardi C, Taioli F, Corra' C, Rizzuto N. X‐LINKED DOMINANT CHARCOT‐MARIE‐TOOTH NEUROPATHY: ANALYSIS OF A PEDIGREE WITH A NOVEL MUTATION OF CONNEXIN 32. J Peripher Nerv Syst 2000. [DOI: 10.1046/j.1529-8027.2000.00513-21.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- G.M. Fabrizi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - A. Polo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - T. Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - C. Pinardi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - F. Taioli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - C. Corra'
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| | - N. Rizzuto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona. Verona
| |
Collapse
|
131
|
Nardelli E, Agazzi P, Polo A, Boaretto M, Cavallaro T, Ferracci F, Moretto G, Rizzuto N. HYPERTROPHY OF SPINAL ROOTS IN CHRONIC INFLAMMATORY DEMYELINATING NEUROPATHY. J Peripher Nerv Syst 2000. [DOI: 10.1046/j.1529-8027.2000.00513-41.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- E. Nardelli
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy. Departments of Medicine Neurology and of
| | - P. Agazzi
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy. Departments of Medicine Neurology and of
| | - A. Polo
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy. Departments of Medicine Neurology and of
| | - M. Boaretto
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy. Departments of Medicine Neurology and of
| | - T. Cavallaro
- Department of Neurological and Visual Sciences, Section of Clinical Neurology, University of Verona, Verona, Italy. Departments of Medicine Neurology and of
| | | | | | - N Rizzuto
- Ospedale di Belluno, , Belluno, Italy
| |
Collapse
|
132
|
Fabrizi GM, Cavallaro T, Taioli F, Orrico D, Morbin M, Simonati A, Rizzuto N. Myelin uncompaction in Charcot-Marie-Tooth neuropathy type 1A with a point mutation of peripheral myelin protein-22. Neurology 1999; 53:846-51. [PMID: 10489052 DOI: 10.1212/wnl.53.4.846] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND The peripheral myelin protein-22 (PMP22) gene has four transmembrane domains, two extracellular loops, and a short cytoplasmic tail. Its roles in the peripheral nervous system remain unclear. The most common cause of Charcot-Marie-Tooth neuropathy type 1A (CMT1A) is a PMP22 gene duplication. Missense point mutations in the transmembrane domains are rare alternative causes that have undetermined pathogenetic mechanisms. OBJECTIVE To investigate the phenotype-to-genotype correlations in a pedigree with unusual CMT1A. METHODS We identified a pedigree with an autosomal dominant motor-sensory neuropathy and severely reduced nerve conduction velocities who did not have the PMP22 duplication. Specimens from sural nerve biopsies from two patients of different ages were evaluated morphometrically. By automated direct nucleotide sequencing we analyzed PMP22 and the gene of the major structural myelin protein zero (P0). RESULTS Nucleotide 159 of PMP22 showed an A-to-T heterozygous mutation, predicted to cause an aspartate-to-valine substitution at codon 37 in the first extracellular loop of the protein. The mutation co-segregated with the disease in the pedigree and was absent in 80 healthy controls. The histopathologic phenotype was a de-remyelinating neuropathy with onion bulb formations, characterized by prominent uncompaction of the myelin sheath in the majority of fibers and by frequent tomacula. CONCLUSION We have described a novel mutation in the first extracellular loop of PMP22 associated with an atypical CMT1A that overlaps pathologically with CMT1B caused by point mutations in the extracellular domain of P0.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, University of Verona, Italy
| | | | | | | | | | | | | |
Collapse
|
133
|
Simonati A, Fabrizi GM, Pasquinelli A, Taioli F, Cavallaro T, Morbin M, Marcon G, Papini M, Rizzuto N. Congenital hypomyelination neuropathy with Ser72Leu substitution in PMP22. Neuromuscul Disord 1999; 9:257-61. [PMID: 10399754 DOI: 10.1016/s0960-8966(99)00008-5] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We describe a patient with congenital hypomyelination neuropathy. The pathological and morphometrical findings in the sural nerve biopsy were consistent with a defect of myelin formation and maintenance. Direct sequence analysis of the genomic regions coding the peripheral myelin proteins P0 and PMP22 disclosed a heterozygous missense point mutation that leads to a Ser72Leu substitution in the second transmembrane of PMP22. Codon 72 mutations of PMP22 are associated with different phenotypes encompassing the Dejerine-Sottas syndrome and including congenital hypomyelination neuropathy.
Collapse
Affiliation(s)
- A Simonati
- Department of Neurological and Visual Sciences, University of Verona, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
134
|
Casali C, Fabrizi GM, Santorelli FM, Colazza G, Villanova M, Dotti MT, Cavallaro T, Cardaioli E, Battisti C, Manneschi L, DiGennaro GC, Fortini D, Spadaro M, Morocutti C, Federico A. Mitochondrial G8363A mutation presenting as cerebellar ataxia and lipomas in an Italian family. Neurology 1999; 52:1103-4. [PMID: 10102446 DOI: 10.1212/wnl.52.5.1103] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Affiliation(s)
- C Casali
- Neurological Institute, La Sapienza University, Rome, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
135
|
Abstract
A patient is described with a Déjérine-Sottas syndrome caused by a novel heterozygous Cys(98)Tyr mutation in the extracellular domain of the major peripheral myelin protein zero (P0ex). Homotypical interactions between P0ex tetramers of apposed extracellular faces of the Schwann cell membrane play a crucial part in myelin compaction. The amino acid change disrupts a unique disulphide bond that stabilises the immunoglobulin-like structure of P0ex and it is predicted to cause severe dehypomyelination through dominant negative effects on the wild type protein.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological and Visual Sciences, University of Verona, Italy
| | | | | | | | | | | |
Collapse
|
136
|
Rizzuto N, Morbin M, Cavallaro T, Ferrari S, Fallahi M, Galiazzo Rizzuto S. Focal lesions area feature of chronic inflammatory demyelinating polyneuropathy (CIDP). Acta Neuropathol 1998; 96:603-9. [PMID: 9845290 DOI: 10.1007/s004010050941] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In a study designed to identify the neuropathological features typical of chronic inflammatory demyelinating polyneuropathy (CIDP), we reviewed the sural nerve biopsy findings in 105 patients with this disorder. The patients' mean age at biopsy was 49 years. In 65% of patients the disease had a progressive and in 35% a relapsing-remitting course. In 47% of cases the disorder was idiopathic; the remainder had various concurrent conditions. All sural nerve biopsy specimens showed varying amounts of active demyelination associated with onion bulbs (48% of cases), endoneurial edema (55%) and inflammatory infiltrates (25%). The immunopathological hallmarks were T cell infiltration with macrophagic activation and up-regulation of major histocompatibility complex (MHC) class II expression, without B cell infiltration or immunoglobulin deposition on myelin sheaths. In 30% of cases some myelin sheaths showed C3d deposition. Analysis of proinflammatory cytokine expression invariably showed interleukin-1 in perivascular and endoneurial ramified cells and tumor necrosis factor-alpha prevalently in epineurial macrophages, whereas it detected interferon-gamma only in samples with perivascular inflammatory cells. This immunological pattern suggests that the cellular components of immunity play the major role in CIDP. In 19% of cases the neuropathological changes had a focal distribution. This distinctive feature corresponded to more active demyelination, more frequent detection of inflammatory infiltrates and more prominent immunological activation, suggesting that focal involvement is a possible step in the course of the disease.
Collapse
Affiliation(s)
- N Rizzuto
- Department of Neurological and Visual Sciences, University of Verona, Policlinico di Borgo Roma, Italy
| | | | | | | | | | | |
Collapse
|
137
|
Fabrizi GM, Simonati A, Morbin M, Cavallaro T, Taioli F, Benedetti MD, Edomi P, Rizzuto N. Clinical and pathological correlations in Charcot-Marie-Tooth neuropathy type 1A with the 17p11.2p12 duplication: a cross-sectional morphometric and immunohistochemical study in twenty cases. Muscle Nerve 1998; 21:869-77. [PMID: 9626246 DOI: 10.1002/(sici)1097-4598(199807)21:7<869::aid-mus4>3.0.co;2-4] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
In a cross-sectional, clinical, and morphometric analysis we assessed the correlation between the clinical and pathological evolution of disease in 20 unrelated patients of various ages affected by Charcot-Marie-Tooth neuropathy type 1A (CMT1A) with the 17p11.2p12 (peripheral myelin protein 22, PMP22) duplication. The severity of neurologic deficits and slowing of motor conduction velocity at the median nerve did not vary significantly with the patients' age. The amount of demyelination was significantly higher below 15 years than in older age groups; in contrast, myelinated fiber and onion bulb densities were similar at all ages. The results indicate that in duplicated CMT1A, the pathological process develops early in life and progresses little during the course of the disease. Younger patients had lower g-ratio values, suggesting that the trigger of demyelination in early years could be a hypermyelination, resulting from PMP22 overexpression. Yet none of the 20 patients examined had immunohistochemical evidence of altered PMP22 expression. The early onset and development of the disorder make it difficult to detect PMP22 overdosage in nerve biopsies.
Collapse
Affiliation(s)
- G M Fabrizi
- Department of Neurological Sciences and Visual Sciences, University of Verona, Policlinico Borgo Roma, Italy
| | | | | | | | | | | | | | | |
Collapse
|
138
|
Abstract
BACKGROUND Two cases of neuroma of the sural nerve after stripping of the small saphenous vein are reported. PATIENTS This 39-year-old woman and this 52-year-old man complained of paresthesia and burning pain, which worsened with walking, in the area of the sural nerve, about 1 month after saphenectomy of the small saphenous vein. RESULTS Exploratory surgery in both cases led to the identification of the spindle neuroma-in-continuity of the sural nerve confirmed histologically. The nerve was sectioned and the proximal stump implanted under the deep fascia. This resulted in complete remission of the symptoms in one case, and partial in the other. CONCLUSION It is likely that the nerve was lacerated during stripping, as a process of periphlebitis might cause adhesion of the vein to the nerve, and then the spindle neuroma developed. The authors underline the necessity of including neuroma of the sural nerve among the possible, albeit rare, complications of stripping of the small saphenous vein.
Collapse
|
139
|
Federico A, Plewnia K, Battisti C, Cavallaro T, Dotti MT, Malandrini A, Manneschi L. Palpebral ptosis and muscle fatiguability associated with perineurial cell ensheathment of muscle fibers: a new disease of the neuromuscular junction? J Neurol Sci 1997; 149:147-50. [PMID: 9171322 DOI: 10.1016/s0022-510x(97)05381-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Perineurial cell ensheathment of muscle fibers has been reported only in one patient. Here we describe a new case with identical morphologic features and a similar, but milder clinical course characterized by progressive muscle weakness and bilateral palpebral ptosis. EMG examination (including repetitive stimulation) and antibodies against acetylcholine receptors were normal. Muscle biopsy revealed several muscle fibers encircled by stratified rings of homogeneous material in which elongated nuclei were visible; this material was positively stained by antibodies directed at epithelial membrane antigen. On ultrastructural examination these encircling-fiber spirals had the characteristics of perineurial cells. It is not clear yet whether perineurial cell ensheathment of muscle fibers is an occasional feature, or whether it has a pathogenetic role in the clinical picture of both cases. The perineurial sheaths might alter the correct neuromuscular transmission mimicking a myasthenia-like disease, either by interfering with the neuromuscular junction, or by changing the microenvironment, and, thus, altering the general excitability of the muscle fibers.
Collapse
Affiliation(s)
- A Federico
- Institute of Neurological Science, University of Siena, Italy.
| | | | | | | | | | | | | |
Collapse
|
140
|
Abstract
Here we report the clinical and pathological findings in a 30-year-old drug addict in whom an intravenous injection of heroin led to reversible coma with respiratory depression and heart failure. On regaining consciousness, the patient was found to have rhabdomyolysis with renal failure requiring dialysis and peripheral neuropathy. Three weeks later his neurological condition suddenly deteriorated and delayed encephalopathy developed, leading to death 20 days later. The neuropathological study of the brain disclosed pale, spongy myelin with diffuse reactive astrogliosis and microglial proliferation, without hypoxic necrotic lesions. The cerebral and cerebellar cortices were unchanged. The absence of typical hypoxic lesions and the presence of spongiosis with massive astrocytosis distinguished this case from the previously reported cases of delayed leukoencephalopathy following severe hypoxia. An immunocytochemical study designed to exclude an underlying alteration of the metabolic oxidative pathway detected normal expression of the respiratory chain complexes IV, III and V. Despite the absence of an oxidative chain alteration in our patient, we cannot exclude the possibility that an individual predisposition played a pathogenetic role in this delayed leukoencephalopathy.
Collapse
Affiliation(s)
- N Rizzuto
- Department of Neurological and Visual Sciences, Policlinico Borgo Roma, University of Verona, Italy.
| | | | | | | | | | | | | |
Collapse
|
141
|
Malandrini A, Carrera P, Palmeri S, Cavallaro T, Fabrizi GM, Villanova M, Fattapposta M, Vismara L, Brancolini V, Tanganelli P, Calì A, Morocutti C, Zeviani M, Ferrari M, Guazzi GC. Clinicopathological and genetic studies of two further Italian families with cerebral autosomal dominant arteriopathy. Acta Neuropathol 1996; 92:115-22. [PMID: 8841656 DOI: 10.1007/s004010050498] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report on two Italian families with an early-adult onset autosomal dominant disorder, characterized by leukoencephalopathy, migraine, psychiatric disturbances, stroke and dementia. These findings fulfill the diagnostic criteria for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome. Moreover, to confirm the CADASIL gene location to 19p12, we performed a linkage analysis with four microsatellite markers. The results of the genetic study gave positive but not significant lod scores, indicating only weak evidence of a linkage with 19p12. In one autopsy case, we found extensive ischemic changes due to the selective involvement of the small muscular arteries of the cerebral white matter. The lesions consisted of a thickening of the media with deposition of granular eosinophilic material. Ultrastructural examination of the arterial walls showed graded damage to smooth muscle cells, mostly of the longitudinal layer, and an abnormal proliferation of basal lamina components. Immunocytochemical analysis showed strong reactivity using antibodies to collagen IV and smooth myosin proteins. The results suggest a primary involvement of the smooth muscle cells of small cerebral arteries, with a secondary alteration of basal lamina components and elastic tissue.
Collapse
Affiliation(s)
- A Malandrini
- Institute of Neurological Sciences, University of Siena, Policlinico Le Scotte, Italy
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
142
|
Fabrizi GM, Cardaioli E, Grieco GS, Cavallaro T, Malandrini A, Manneschi L, Dotti MT, Federico A, Guazzi G. The A to G transition at nt 3243 of the mitochondrial tRNALeu(UUR) may cause an MERRF syndrome. J Neurol Neurosurg Psychiatry 1996; 61:47-51. [PMID: 8676159 PMCID: PMC486456 DOI: 10.1136/jnnp.61.1.47] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
OBJECTIVE To verify the phenotype to genotype correlations of mitochondrial DNA (mtDNA) related disorders in an atypical maternally inherited encephalomyopathy. METHODS Neuroradiological, morphological, biochemical, and molecular genetic analyses were performed on the affected members of a pedigree harbouring the heteroplasmic A to G transition at nucleotide 3243 of the mitochondrial tRNALeu(UUR), which is usually associated with the syndrome of mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). RESULTS The proband was affected by a fullblown syndrome of myoclonic epilepsy with ragged red fibres (MERRF), severe brain atrophy, and basal ganglia calcifications, without the MRI T2 hyperintense focal lesions which are pathognomonic of MELAS. Oligosymptomatic relatives were variably affected by lipomas, goitre, brain atrophy, and basal ganglia calcifications. Muscle biopsies in the proband and his mother showed a MELAS-like pattern with cytochrome c oxidase hyperreactive ragged red fibres and strongly succinate dehydrogenase reactive vessels. Quantification of the A3243G mutation disclosed 78% and 70% of mutated mtDNA in the muscle of the severely affected proband and of his oligosymptomatic mother respectively. Nucleotide sequencing of the mitochondrial tRNALeu(UUR) and tRNALys in the proband's muscle failed to show any additional nucleotide change which could account for the clinical oddity of this pedigree by modulating the expression of the primary pathogenic mutation. CONCLUSION So far, MERRF has been associated with mutations of the mitochondrial tRNALys, and MELAS with mutations of the mitochondrial tRNALeu(UUR). Now MERRF may also be considered among the clinical syndromes associated with the A to G transition at nt 3243 of the tRNALeu(UUR).
Collapse
Affiliation(s)
- G M Fabrizi
- Istituto di Scienze Neurologiche, Università di Siena, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
143
|
Fabrizi GM, Lodi R, D'Ettorre M, Malandrini A, Cavallaro T, Rimoldi M, Zaniol P, Barbiroli B, Guazzi G. Autosomal dominant limb girdle myopathy with ragged-red fibers and cardiomyopathy. A pedigree study by in vivo 31P-MR spectroscopy indicating a multisystem mitochondrial defect. J Neurol Sci 1996; 137:20-7. [PMID: 9120483 DOI: 10.1016/0022-510x(95)00321-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
We describe a late-onset autosomal dominant limb girdle myopathy, associated with dilated cardiomyopathy and mental deterioration. In two affected members of the pedigree with histochemical (ragged-red and cytocrome c oxidase - negative fibers) and ultrastructural abnormalities of muscle mitochondria, in vivo muscle phosphorus MR spectroscopy disclosed a slow rate of phosphocreatine resynthesis after exercise. Brain phosphorus MR spectroscopy revealed a defect of the energy metabolism in the two patients and in a third asymptomatic member, as shown by a significantly low phosphocreatine, increased ADP and decreased phosphorylation potential. Molecular analysis of muscle mitochondrial DNA failed to reveal any known mutation, including multiple deletions of the mtDNA which have been associated with some autosomal dominant mitochondrial diseases. The multisystem clinical involvement, the presence of ragged-red fibers and the alterations revealed by in vivo brain and muscle 31P-MRS suggest that this limb-girdle syndrome represents an unusual phenotype of mitochondrial cytopathy.
Collapse
Affiliation(s)
- G M Fabrizi
- Istituto di Scienze Neurologiche, Universitat di Siena, Policlinico Le Scotte, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
144
|
Malandrini A, Fabrizi GM, Cavallaro T, Zazzi M, Parrotta E, Romano L, Berti G, Villanova M, Guazzi GC. Neuronal intranuclear inclusion disease: polymerase chain reaction and ultrastructural study of rectal biopsy specimen in a new case. Acta Neuropathol 1996; 91:215-8. [PMID: 8787158 DOI: 10.1007/s004010050417] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
We report the case of a boy with neuronal intranuclear inclusion disease in whom the diagnosis was made by examination of a rectal biopsy specimen. Intranuclear inclusions were observed in the Auerbach and Meissner plexuses. In an attempt to understand the physiopathology of this very rare disease, we performed polymerase chain reaction (PCR) and reverse transcriptase-PCR analysis for viral nucleic acids of human immunodeficiency virus type 1 (HIV-1), HIV-2, human cytomegalovirus and measles virus. No viral nucleic acids were detected in the biopsy specimen.
Collapse
Affiliation(s)
- A Malandrini
- Institute of Neurological Sciences, University of Siena, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
145
|
Malandrini A, Cavallaro T, Fabrizi GM, Berti G, Salvestroni R, Salvadori C, Guazzi GC. Ultrastructure and immunoreactivity of dystrophic axons indicate a different pathogenesis of Hallervorden-Spatz disease and infantile neuroaxonal dystrophy. Virchows Arch 1995; 427:415-21. [PMID: 8548127 DOI: 10.1007/bf00199391] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
An immunohistochemical and ultrastructural analysis of dystrophic axons (DAs) in the brain and peripheral nerve of a patient with familial infantile neuroaxonal dystrophy (INAD) and in the brain of a patient with familial Hallervorden-Spatz Disease (HSD) revealed prevalent membrano-tubular or granulo-vesicular profiles with a graded pattern of evolution in INAD, while dense bodies, vesicles and amorphous material were present in HSD. DAs immunoreactivity with tai-protein and 200 kDa-neurofilament antibodies was stronger in HSD than in INAD. In both cases immunohistochemistry was positive for ubiquitin and negative for beta-tubulin and beta-amyloid. Distinct ultrastructural features and immunoreactivity pattern of cytoskeletal components suggest different pathogenetic mechanisms.
Collapse
Affiliation(s)
- A Malandrini
- Institute of Neurological Sciences, University of Siena, Italy
| | | | | | | | | | | | | |
Collapse
|
146
|
Rizzuto N, Cavallaro T, Monaco S, Morbin M, Bonetti B, Ferrari S, Galiazzo-Rizzuto S, Zanette G, Bertolasi L. Role of HIV in the pathogenesis of distal symmetrical peripheral neuropathy. Acta Neuropathol 1995; 90:244-50. [PMID: 8525797 DOI: 10.1007/bf00296507] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
We report the results of a clinical, electrophysiological and pathological study conducted in 18 AIDS patients presenting a distal symmetrical predominantly sensory polyneuropathy (DSPN) characterized by painful dysesthesias as main complaint. Onset of the neuropathy was at CDC (Center for Disease Control) stage II in 2 patients, at CDC stage III in 5 patients and at CDC stage IV in the remainder. Electrophysiological investigation confirmed the presence of an axonal alteration in the sensory nerves, but also revealed motor involvement in all cases. The neuropathological features of sensory nerves were fiber loss and axonal degeneration with macrophagic activation. The expression of monocyte-macrophage markers and of major histocompatibility complex class II antigens appeared up-regulated in endoneurial ramified cells, while expression of CR3, a complement receptor involved in the process of phagocytosis, was down-regulated. In six nerve biopsy samples and in two out of five DSPN dorsal root ganglia we found HIV-related mRNA and protein located in scattered cells of the endoneurium which we presume to be macrophages. These data suggest that: (a) DSPN may occur early in the course of the disease and is not limited to later stages; (b) DSPN is not a ganglionitis but is actually a sensory-motor neuropathy; (c) the virus enters the peripheral nervous system and induces changes in the immunocompetent cell population with activation of macrophages. Storage of the virus inside macrophages may act both as a reservoir for the virus and as a putative cause of nerve damage, probably through release of cytotoxins and/or interaction with trophic factors.
Collapse
Affiliation(s)
- N Rizzuto
- Department of Neurological and Visual Sciences, University of Verona, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
147
|
Lazzarino LG, Nicolai A, Cavallaro T, Rizzuto N. Neurotoxicity of idiopathic hypereosinophilia on a case with simultaneous CNS and PNS involvement. Ital J Neurol Sci 1993; 14:259-62. [PMID: 8390972 DOI: 10.1007/bf02335668] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
We report the case of a patient with idiopathic hypereosinophilia in whom both central and peripheral nervous systems were affected. We discuss possible pathogenetic mechanisms explaining the neurotoxicity of idiopathic hypereosinophilia. Corticosteroid therapy should be given early and continued indefinitely.
Collapse
|
148
|
Cavallaro T, Martone RL, Stylianopoulou F, Herbert J. Differential expression of the insulin-like growth factor II and transthyretin genes in the developing rat choroid plexus. J Neuropathol Exp Neurol 1993; 52:153-62. [PMID: 8440997 DOI: 10.1097/00005072-199303000-00008] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023] Open
Abstract
Choroid plexus (CP) development may depend on an inductive interaction between primordial CP epithelium and the overlying mesenchyme. Expression of the two CP epithelial-expressed genes, transthyretin (TTR) and insulin-like growth factor II (IGF-II), were studied by in situ hybridization in the developing rat. Transthyretin mRNA is expressed in abundance in the primordial CP epithelium prior to CP morphogenesis (e10-11) but IGF-II mRNA expression begins later (e13) and increases gradually as morphogenesis proceeds. In the CP stroma (mesenchyme), IGF-II mRNA is abundant prior to CP morphogenesis but decreases as embryogenesis proceeds and is absent in the adult. Our findings suggest that IGF-II may play an early paracrine and later autocrine role in CP development. A model is proposed in which IGF-II synthesized by mesenchyme serves as an inducing principle for CP epithelial differentiation.
Collapse
Affiliation(s)
- T Cavallaro
- Department of Neurology, Columbia University, College of Physicians and Surgeons, New York, NY
| | | | | | | |
Collapse
|
149
|
Mizuno R, Cavallaro T, Herbert J. Temporal expression of the transthyretin gene in the developing rat eye. Invest Ophthalmol Vis Sci 1992; 33:341-9. [PMID: 1740364] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Transthyretin (TTR) is a 55-kilodalton tetrameric protein that plays an important role in the plasma transport of thyroxine and retinol. Plasma TTR is synthesized in the liver, but major sites of synthesis also have been described in the choroid plexus (CP) epithelium, the visceral yolk sac, and the eye. Recently, the retinal pigment epithelium (RPE) was identified as the specific site of TTR synthesis in the rat eye, and it was suggested that this established a functional homology between the RPE and the CP epithelium. In this study, the temporal pattern of TTR mRNA expression was investigated in the rat eye and brain during development (embryonic day 10 [e10]-postnatal day 7 [P7]) by in situ hybridization and quantitative densitometry. The TTR mRNA was present in abundance in the primordial CP before organogenesis (e10-12), but in the eye, TTR mRNA first was detected at considerably lower levels after organogenesis (e16) and only in a subset of RPE cells in the equatorial region. The relative abundance of TTR mRNA in RPE rose gradually until e21, but on the first day of life a surge was seen, followed by stabilization at adult levels by P7. These findings suggest that the requirement for TTR in CP and RPE, and possibly its function, may differ during development. The postnatal surge in RPE TTR message levels raises the possibility that transcription of the TTR gene in the newborn animal may be responsive to newly encountered environmental stimuli in the perinatal period, such as incident light.
Collapse
Affiliation(s)
- R Mizuno
- Department of Neurology, Columbia University, College of Physicians and Surgeons, New York, New York
| | | | | |
Collapse
|
150
|
Herbert J, Cavallaro T, Martone R. The distribution of retinol-binding protein and its mRNA in the rat eye. Invest Ophthalmol Vis Sci 1991; 32:302-9. [PMID: 1993581] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
Although a constant supply of retinol is a critical requirement for the visual cycle, the molecular mechanisms underlying retinol delivery, uptake, storage, and transport in the eye are not well understood. Previously the synthesis of serum retinol-binding protein (RBP) in the mammalian eye was reported. Now the distribution of RBP and RBP mRNA in the rat eye has been studied by immunohistochemical and in situ hybridization techniques has been studied. The RBP mRNA was present only in the cytoplasm of retinal pigment epithelial (RPE) cells, terminating abruptly at the pars plana. On the other hand, RBP immunoreactivity was more widespread. The most intense immunostaining was present in retinal ganglion cells, the corneal endothelium, and under certain conditions of tissue fixation, the corneal epithelium. Consistent but less intense immunoreactivity was detected in the photoreceptors, Müller cells, inner plexiform layer, ciliary epithelium and stroma, iris epithelium, retinal pigment epithelium, lacrimal glandular epithelium, and periorbital soft tissues. These findings suggest that RBP synthesized by the RPE may be secreted to various ocular locations. However, at present, uptake from plasma cannot be excluded as another possible source of ocular RBP. In the plasma, holo-RBP (the retinol-RBP complex) is transported in complex with another plasma protein, transthyretin (TTR). This substance is also synthesized by the RPE and its distribution in the eye is similar to that described for RBP. Taken together, these findings support the proposal that ocular RBP and TTR may function cooperatively in the intraocular translocation of retinol.
Collapse
Affiliation(s)
- J Herbert
- Department of Neurology, Columbia University, College of Physicians and Surgeons, New York City, NY
| | | | | |
Collapse
|