Peripheral neuropathy in late-onset Krabbe disease: report of three cases.

Late-onset Krabbe disease may have variable misleading clinical manifestations and be a puzzling problem for physicians. We report clinical and peripheral nerve studies of three patients with adult-onset Krabbe disease. Two cases had a predominantly spastic paraparesis; in one case, the symptoms mimicked a cerebrovascular disorder. Predominantly, demyelinating neuropathy was observed in one case and axonal neuropathy in two cases. In all cases, no typical intracytoplasmic inclusions were found. These observations suggest that peripheral neuropathy in adult-onset Krabbe disease has variable clinical and pathological characteristics, different from those described in the classic form.

Evaluation of brain apoptosis in a CADASIL postmortem case.

OBJECTIVE: To evaluate the role of apoptosis in the pathogenesis of brain lesions in cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), a hereditary microangiopathy leading to cognitive decline and dementia, caused by mutations in the NOTCH3 gene. MATERIALS AND METHODS: Detection of apoptotic nuclei in temporal lobe, brain stem, medulla oblongata, hippocampus and basal ganglia from one young CADASIL patient was performed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP nick end-labeling (TUNEL). RESULTS: Our results showed a great involvement of glial cells in apoptotic cell death in the majority of the brain regions examined; neuronal apoptosis was significantly present only in the brain stem region. CONCLUSIONS: We hypothesized that in the early stages of the disease neuronal involvement of apoptosis is limited to the cells of the brain stem, sparing the cortical area which is involved in neuronal apoptosis and cognitive decline later.

CSF levels of beta-amyloid 1-42, tau and phosphorylated tau protein in CADASIL.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) can be considered a useful model of pure subcortical vascular dementia (SVD) because it occurs in young adults, unlikely to have concomitant age- and Alzheimer's disease (AD)-related pathology. In patients with CADASIL we evaluated the cerebrospinal fluid (CSF) levels of beta-amyloid 1-42 (Abeta42), total tau protein (t-tau) and phosphorylated tau protein (p-tau), which are well-accepted biomarkers of AD. METHODS: The CSF Abeta42, t-tau and p-tau levels were determined with Innotest beta-amyloid 1-42, Innotest hTAU-Ag and Innotest Phospho-tau 181p sandwich enzyme-linked immunoassay, in 10 CADASIL patients and 17 healthy age-matched subjects. A case-control statistical analysis was carried out. RESULTS: CSF Abeta42 levels were significantly lower in CADASIL patients than in controls, whereas CSF t-tau and p-tau levels did not differ between the two groups. CONCLUSIONS: The pattern found in CADASIL patients is similar to that reported in those with sporadic SVD, suggesting that decreased CSF Abeta42 might be related to the subcortical vascular lesions in the white matter.

Prominent brain axonal damage and functional reorganization in "pure" adrenomyeloneuropathy.

BACKGROUND: Cerebral involvement is usually absent in pure adrenomyeloneuropathy (AMN). Recently, nonconventional MR studies have reported brain abnormalities in patients with pure AMN, providing evidence that occult cerebral involvement may occur in this disease. It remains unclear, however, whether these brain abnormalities reflect centripetal extension of spinal cord long-tract axonopathy or can be the expression of a pathologic process largely involving the brain. METHODS: Conventional MRI and proton MR spectroscopic imaging (1H-MRSI) data of four patients with pure AMN were compared to those of four men with spinal cord injury (SCI) and 10 age-matched healthy men (HM). Resonance intensity areas of N-acetylaspartate (NAA) and choline were calculated as ratios to creatine (Cr) in voxels located in white matter (WM) regions. Functional MRI (fMRI) data during simple motor task were obtained in a separate session in three patients with AMN and three age-matched HM. RESULTS: Conventional MRI examinations were normal in all patients. On 1H-MRSI, NAA/Cr values were lower in all WM regions of patients with AMN than in those of patients with SCI (p < 0.05) and HM (p < 0.01). In contrast, patients with SCI showed NAA/Cr values lower than HM only in the periventricular WM (p = 0.04). At fMRI, patients with AMN showed a more pronounced activation than HM in all movement-associated cortical regions contralateral to the hand moved and an exclusive voxel activation of the primary motor, somatosensory, and posterior parietal cortices ipsilateral to the hand moved. CONCLUSIONS: CNS damage in pure adrenomyeloneuropathy is not confined exclusively to spinal cord and seems to primarily involve the brain.

Human fibroblasts undergo oxidative stress-induced apoptosis without internucleosomal DNA fragmentation.

In order to evaluate the reliability of fibroblasts as a cell model for studying apoptosis, we tested the response of normal human fibroblasts to the oxidative stress inducers H(2)O(2) and 2-deoxy-D-ribose (dRib). Our results showed that fibroblasts treated with dRib and H(2)O(2) are induced to undergo apoptosis as demonstrated by reduction in total cell number, chromatin condensation, phosphatidylserine (PS) exposure, activation of caspase-3 and 7, changes in mitochondrial membrane potential and increase in the number of terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling (TUNEL)-positive nuclei. However we only found a slight increase in the percentage of cells in the sub-G1 region evaluated by flow cytometry, and we did not observe DNA fragmentation by agarose gel electrophoresis. Early in apoptosis, DNA cleavage generates high molecular weight (HMW) fragments which can be detected by TUNEL assay; successively followed by a pronounced DNA brake down into low molecular weight (LMW) fragments, detected as a "DNA ladder" by conventional agarose gel electrophoresis and as an hypodiploid peak by propidium iodide (PI) flow cytometry assay. Our results thus suggest that only HMW fragmentation occurs in fibroblasts exposed to dRib or H(2)O(2) and the lack of internucleosomal DNA fragmentation may depend on the peculiar characteristics of human fibroblasts themselves, irrespective of the apoptotic stimulus used. The existence of distinct events leading to cell death in different cell types makes it necessary to use a combination of strategies and techniques to evaluate the occurrence of apoptosis.

Cell response to oxidative stress induced apoptosis in patients with Leber's hereditary optic neuropathy.

OBJECTIVES: Leber's hereditary optic neuropathy (LHON) is a maternally inherited disease in which acute or subacute bilateral visual loss occurs preferentially in young men. Over 95% of LHON cases are associated with one of three mitochondrial DNA (mtDNA) point mutations, but only 50% of men and 10% of women who harbour a pathogenetic mtDNA mutation develop optic neuropathy. This incomplete penetrance and preference for men suggests that additional genetic (nuclear or mitochondrial) and/or environmental factors must modulate phenotype expression in LHON. A role for reactive oxygen species (ROS) in mitochondrial diseases, secondary to mtDNA mutations, or as a result of the direct effect of ROS cytotoxicity, has been implicated in many mitochondrial disorders, including LHON. The purpose of this study was to investigate the role of oxidative stress induced apoptosis in LHON. METHODS: The 2-deoxy-D-ribose induced apoptotic response of peripheral blood lymphocytes from six patients with LHON and six healthy subjects was investigated using light microscopy, flow cytometry, agarose gel electrophoresis, and the measurement of mitochondrial membrane potential. RESULTS: Cells of patients with LHON had a higher rate of apoptosis than those of controls and there was evidence of mitochondrial involvement in the activation of the apoptotic cascade. CONCLUSIONS: These differences in oxidative stress induced apoptosis are in line with the hypothesis that redox homeostasis could play a role in the expression of genetic mutations in different individuals and could represent a potential target in the development of new therapeutic strategies.

DNA end labelling (TUNEL) in a 3 year old girl with Leigh syndrome and prevalent cortical involvement.

Neuropathological study of a 3 1/2 year old girl with familial Leigh syndrome who also harboured a rare ATPase gene mutation disclosed extensive and unusual lesions in the cerebral cortex, despite a typical histological pattern. Early lesions in the periacqueductal grey matter of the brainstem, characterised by capillary congestion and initial regressive neuronal changes, were also observed, along with TUNEL reactive neuronal cells showing morphological signs typical of apoptosis in cortical areas with neuronal cell loss. The finding of lesions in atypical brain areas and for the first time, very early regressive neuronal phenomena, suggest that early changes in crucial brain areas may have been a cause of death. The abundance of TUNEL positive nuclei in cortical areas in the present case suggests that the apoptosis may be involved in the mechanism of neuronal death in Leigh syndrome.

Evidence of apoptosis via TUNEL staining in muscle biopsy from patients with mitochondrial encephaloneuromyopathies.

Apoptosis is an evolution-conserved form of cell death essential for development and maintenance of tissue homeostasis. Dysregulation of apoptosis has been implicated in several pathological conditions, including neurodegenerative disorders. The crucial role of mitochondria in regulation of the apoptotic pathway prompted us to investigate the pattern of apoptosis in muscle biopsies from 17 patients with mitochondrial encephaloneuromyopathies caused by mtDNA defects. The results were compared with muscle biopsies from controls and from patients with myopathies without mitochondrial impairment. The terminal deoxynucleotidyl transferase-mediated dUTP nick and labelling (TUNEL) reaction was used as marker of apoptosis. Our findings were very heterogeneous, even between patients with the same mtDNA mutations, suggesting that tissue evaluation of apoptotic process is less useful than in vitro techniques, for investigating the role of apoptosis in mitochondrial pathologies.

Genetic leukoencephalopathies with unknown metabolic pathogenesis.

The authors describe the principal forms of genetic leucodystrophies with unknown metabolic pathogenesis, indicating their main clinical signs and the new findings concerning the molecular genetic that are useful for the laboratory confirmation of the clinical suspicion.

Enhanced 2-deoxy-D-ribose-induced-apoptosis, a phenotype of lymphocytes from old donors, is not observed in the Werner syndrome.

Werner syndrome (WS) is an inherited disease characterized by the premature appearance of features of normal aging in young adults. To evaluate the relationship between Werner syndrome and aging, we analyzed the apoptotic response of peripheral blood lymphocytes (PBLs) from two WS patients (mean age 34 years old) incubated with 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis in quiescent cells through an oxidative stress; the results have been compared to two control groups (mean age 35 and 83 years old, respectively). The presence of apoptotic cells was detected by light microscopy, flow cytometry, and agarose gel electrophoresis. In all three groups an increased time-dependent apoptotic response was evident, but the apoptotic response to dRib was lower in WS's cells than in cells from age-matched controls and less than in cells from older subjects. Our results confirm a low susceptibility of WS cells to DNA damaging agents as dRib and suggest that the pathogenic mechanisms underlying normal cellular aging and WS's cellular senescence may be different.

Apoptotic response and cell cycle transition in ataxia telangiectasia cells exposed to oxidative stress.

The recently identified ATM gene plays a role in a signal transduction network activating multiple cellular functions in response to DNA damage. An attractive hypothesis is that the ATM protein is involved in a specialized antioxidant system responsible for detoxifying reactive oxygen intermediate and that the absence or dysfunction of this protein in AT cells would render them less capable of dealing with oxidative stress. In order to investigate the role of the ATM gene in cell cycle control and programmed cell death, Lymphoblastoid cell lines derived from four Ataxia-Telangiectasia (AT) patients and six controls have been analyzed. All cell lines were incubated with 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis through oxidative stress. The result showed an impaired response to dRib-induced apoptosis in AT cells, as well as a defect of cellular cycle arrest in G1/S phase and a normal expression of p53 protein. This indicate that the kinase activity of ATM gene product plays a very important role in the cellular response to oxidative stress. In conclusion the altered response of AT cells to oxidative stress and particularly their resistance to apoptotic cell death, could explain the high predisposition of these cells to progress toward malignant transformation.

Vitamin E serum levels and gastric cancer: results from a cohort of patients in Tuscany, Italy.

Alpha-tocopherol has been reported to play an important role against oxidative damage and in the inhibition of cell transforming and mutagenesis. We analysed vitamin E serum levels in 51 cases of patients affected by gastric cancer at different stages of the disease, and in 49 age-matched controls. All patients had normal values of alpha-tocopherol. However, when patients have been grouped according to histotype of gastric lesions, a significant vitamin E increase has been found in diffuse gastric cancer histotype compared to the intestinal histotype. Our results suggest that a correlation between vitamin E serum levels and gastric cancer histotype should be considered.

Clinical and stabilometric monitoring in a case of cerebellar atrophy with vitamin E deficiency.

The authors describe a case of early onset ataxia with cerebellar atrophy and vitamin E deficiency, treated with alpha-tocopherol supplementation and physically rehabilitated by postural biofeedback. Clinical assessments, serum vitamin E levels and postural evaluation by means of a stabilometric platform continued for about 2 years and significant clinical improvement was recorded. Our study confirms that combined physical therapy and vitamin E supplementation may result in improvement of cerebellar function. Motor improvement is directly related to vitamin E serum levels, providing further confirmation that normal vitamin E levels are crucial for proper brain functions.

Vitamin E serum levels in Rett syndrome.

In order to study the role of vitamin E in the pathogenesis of Rett syndrome (RS), we analysed vitamin E serum levels in twenty-eight patients affected by this disorder. We found lower vitamin E serum levels in nine cases (32.1%). These results indicated that the oxidative free radical metabolism may be impaired in a significant percentage of Rett syndrome patients suggesting the need for further studies of tissue vitamin E in different brain regions.

Increased apoptotic response to 2-deoxy-D-ribose in ataxia-telangiectasia.

Ataxia-telangiectasia (AT) is an autosomal recessive disease characterized by neurodegeneration and immunodeficiency. Hypersensitivity to radiation and chromosome instability are the biological markers of this disease. The gene responsible for AT (ATM), has been identified on chromosome 11q22-23; it encodes a large polypeptide partially homologous to the phosphatidylinositol (PI) 3-kinase family. PI 3-kinase is a protein family playing an important role in the prevention of apoptosis. In order to investigate the apoptosis pathway, we tested peripheral blood cells from AT patients and controls exposed to 2-deoxy-D-ribose (dRib), a reducing sugar that induces apoptosis in human quiescent lymphocytes, probably through oxidative damage. Our results show that the response to dRib-induced apoptosis is significantly more elevated in AT cells than in control cells, suggesting that the apoptotic process plays a role in the pathogenesis of AT disease.

Vitamin E serum levels are normal in ataxia telangiectasia (Louis-Bar disease).

In order to study the role of vitamin E in the pathogenesis of ataxia telangiectasia, we analysed vitamin E serum levels in five children with this disorder. No differences with respect to controls were found. However, these negative results do not exclude that abnormal vitamin E metabolism may be present at the cellular level.

Disappearance of skin lipofuscin storage and marked clinical improvement in adult onset coeliac disease and severe vitamin E deficiency after chronic vitamin E megatherapy.

A case of adult onset coeliac disease with IgA and severe vitamin E deficiencies, associated with cerebellar impairment and peripheral neuropathy, is described. Nerve conduction velocities, BAERs and SEP were altered. Brain nMR showed cortical atrophy mainly in the frontal and parietal regions. At ultrastructural examination, nerve biopsy showed a severe nerve fiber loss with presence of lipofuscin. Lipofuscin has been also found in skin and muscle biopsy. Duodenal biopsy showed villar atrophy with criptae hypoplasia. IgA, Apo A1 lipoprotein and cholesterol were decreased. Serum level of vitamin E was not detectable and its amount did not increase after an oral loading (2 g bolus). Parenteral vitamin E administration (900 mg/day) was able to normalize the plasma values only after 6 months of chronic administration of the drug in coincidence with a significant improvement of clinical and neurophysiological signs, and disappearance of lipofuscin storage in the skin biopsy.

Plasma levels of vitamin E in Parkinson's disease.

We report the analysis of plasma levels of vitamin E that has been found normal in 20 italian patients with Parkinson's disease (PD) confirming the previously reported results from other groups. We discuss the literature data about the possible protective effect of antioxidant agents in the PD and generally in the aging processes.