Impaired copper and iron metabolism in blood cells and muscles of patients affected by copper deficiency myeloneuropathy.

AIMS: Severe copper deficiency leads in humans to a treatable multisystem disease characterized by anaemia and degeneration of spinal cord and nerves, but its mechanisms have not been investigated. We tested whether copper deficit leads to alterations in fundamental copper-dependent proteins and in iron metabolism in blood and muscles of patients affected by copper deficiency myeloneuropathy, and if these metabolic abnormalities are associated with compensatory mechanisms for copper maintenance. METHODS: We evaluated the expression of critical copper enzymes, of iron-related proteins, and copper chaperones and transporters in blood and muscles from five copper-deficient patients presenting with subacute sensory ataxia, muscle paralysis, liver steatosis and variable anaemia. Severe copper deficiency was caused by chronic zinc intoxication in all of the patients, with an additional history of gastrectomy in two cases. RESULTS: The antioxidant enzyme SOD1 and subunit 2 of cytochrome c oxidase were significantly decreased in blood cells and in muscles of copper-deficient patients compared with controls. In muscle, the iron storage protein ferritin was dramatically reduced despite normal serum ferritin, and the expression of the haem-proteins cytochrome c and myoglobin was impaired. Muscle expression of the copper transporter CTR1 and of the copper chaperone CCS, was strikingly increased, while antioxidant protein 1 was diminished. CONCLUSIONS: copper-dependent enzymes with critical functions in antioxidant defences, in mitochondrial energy production, and in iron metabolism are affected in blood and muscles of patients with profound copper deficiency leading to myeloneuropathy. Homeostatic mechanisms are strongly activated to increase intracellular copper retention.

Effects of manidipine and delapril in hypertensive patients with type 2 diabetes mellitus: the delapril and manidipine for nephroprotection in diabetes (DEMAND) randomized clinical trial.

To assess whether angiotensin-converting enzyme inhibitors and third-generation dihydropyridine calcium channel blockers ameliorate diabetic complications, we compared glomerular filtration rate (GFR; primary outcome), cardiovascular events, retinopathy, and neuropathy in 380 hypertensive type 2 diabetics with albuminuria <200 mg/min included in a multicenter, double-blind, placebo-controlled trial (DEMAND [Delapril and Manidipine for Nephroprotection in Diabetes]) and randomized to 3-year treatment with manidipine/delapril combination (10/30 mg/d; n=126), delapril (30 mg/d; n=127), or placebo (n=127). GFR was centrally measured by iohexol plasma clearance. Median monthly GFR decline (interquartile range [IQR]) was 0.32 mL/min per 1.73 m(2) (IQR: 0.16-0.50 mL/min per 1.73 m(2)) on combined therapy, 0.36 mL/min per 1.73 m(2) (IQR: 0.18-0.53 mL/min per 1.73 m(2)) on delapril, and 0.30 mL/min per 1.73 m(2) (IQR: 0.12-0.50 mL/min per 1.73 m(2)) on placebo (P=0.87 and P=0.53 versus combined therapy or delapril, respectively). Similar findings were observed when baseline GFR values were not considered for slope analyses. Albuminuria was stable in the 3 treatment groups. The hazard ratio (95% CI) for major cardiovascular events between combined therapy and placebo was 0.17 (0.04-0.78; P=0.023). Among 192 subjects without retinopathy at inclusion, the hazard ratio for developing retinopathy between combined therapy and placebo was 0.27 (0.07-0.99; P=0.048). Among 200 subjects with centralized neurological evaluation, the odds ratios for peripheral neuropathy at 3 years between combined therapy or delapril and placebo were 0.45 (0.24-0.87; P=0.017) and 0.52 (0.27-0.99; P=0.048), respectively. Glucose disposal rate decreased from 5.8±2.4 to 5.3±1.9 mg/kg per min on placebo (P=0.03) but did not change on combined or delapril therapy. Treatment was well tolerated. In hypertensive type 2 diabetic patients, combined manidipine and delapril therapy failed to slow GFR decline but safely ameliorated cardiovascular disease, retinopathy, and neuropathy and stabilized insulin sensitivity.

Clinical and radiological features of brain neurotoxicity caused by antitumor and immunosuppressant treatments.

Antitumor and immunosuppressant treatment-related neurotoxicity can determine nonspecific clinical syndromes. Exclusion of other possible causes, among which tumor progression, appearance of paraneoplastic disease, renal or hepatic failure, diabetes or hypertension, is relevant. We report clinical and neuroradiological features in five patients with neurotoxic syndromes due to chemotherapy/radiotherapy or immunosuppression in the context of neoplastic disease/organ transplantation. Acute neurological syndrome developed in three patients after methotrexate (MTX), cyclosporine A, and L-asparaginase therapy, respectively. MRI showed posterior reversible encephalopathy in two cases and venous thrombosis with intraparenchymal hematoma in the third patient. Late onset clinical syndrome occurred in the last two patients, treated with MTX or radiation therapy for breast cancer metastasis and pituitary adenoma. Neuroimaging showed brain diffuse abnormalities. Patients affected by tumors suffer from increased risk for treatment-related toxicities. Appearance or worsening of neurological signs and symptoms challenge the clinician to discriminate between CNS involvement by the tumor, toxicity of drugs, parane-oplastic disease and infections. MRI has a key role in differential diagnosis. Close interaction between the neurologist, the oncologist and the neuroradiologist leads to the optimal management of patients.

Normal expression of myelin protein zero with frame-shift mutation correlates with mild phenotype.

Mutations in the gene encoding for myelin protein zero (MPZ) cause inherited demyelinating peripheral neuropathies of different severity. The molecular and cellular mechanisms by which the MPZ mutations cause neuropathy are incompletely understood. We investigated MPZ, myelin basic protein, and peripheral myelin protein 22 (PMP22) protein expression levels in a nerve biopsy of a Charcot-Marie-Tooth type 1B patient heterozygous for the Val 102 frame-shift mutation. We demonstrate by quantitative immunohistochemical as well as by Western blot analyses that MPZ expression levels were not reduced in myelin membranes, a finding that is in accordance with the mild phenotype of this patient. Our data show that heterozygous 'loss-of-function' of MPZ may not necessarily lead to reduced protein levels. In conclusion, we demonstrate that careful analysis of protein expression levels in peripheral nerve tissues provides important information with respect to the understanding of the molecular basis of these neuropathies.

Sensory neuron diseases.

Sensory neuron diseases (SND) are a distinct subgroup of peripheral-nervous-system diseases, first acknowledged in 1948. Acquired SND have a subacute or chronic course and are associated with systemic immune-mediated diseases, vitamin intoxication or deficiency, neurotoxic drugs, and life-threatening diseases such as cancer. SND are commonly idiopathic but can be genetic diseases; the latter tend to involve subtypes of sensory neurons and are associated with certain clinical pictures. The loss of sensory neurons in dorsal root ganglia causes the degeneration of short and long peripheral axons and central sensory projections in the posterior columns. This pathological process leads to a pattern of sensory nerve degeneration that is not length dependent and explains distinct clinical and neurophysiological abnormalities. Here we propose a comprehensive approach to the diagnosis of acquired and hereditary SND and discuss clinical, genetic, neurophysiological, neuroradiological, and neuropathological assessments.

Tubule and neurofilament immunoreactivity in human hairy skin: markers for intraepidermal nerve fibers.

The cytoplasmic protein gene product 9.5 (PGP 9.5) is considered a reliable marker for intraepidermal nerve fibers (IENFs). However, PGP 9.5 expression has never been compared with antibodies against the main components of the cytoskeleton. We compared the density of PGP 9.5-positive IENF at the leg with that obtained using a panel of antibodies specific for certain cytoskeletal components, namely, anti-unique beta-tubulin (TuJ1), anti-nonphosphorylated microtubule-associated protein-1B (MAP1B), anti-70 and 200 KDa neurofilament (NF), and antiphosphorylated neurofilament (SMI 312), in 15 healthy subjects and in 10 patients with painful neuropathy. We also performed colocalization studies and investigated the relationship between IENFs and Schwann cells. In both controls and neuropathies, the density of IENF labeled by PGP 9.5, TuJ1, and MAP1B did not differ, whereas that of NF and SMI 312 was significantly lower. Double-staining studies confirmed that antibodies against cytoskeletal markers can be used to reliably stain skin nerve fibers, suggesting that they might provide insight into specific axonal impairment in peripheral neuropathies.

Neurophysiological diagnosis of acquired sensory ganglionopathies.

We examined 29 patients with chronic progressive ganglionopathy of different etiology. Neurophysiological abnormalities were dominated by a widespread decrease in sensory nerve action potential amplitudes, which involved both upper and lower limb nerves, even in patients with asymmetrical or patchy clinical presentation. This impairment of sensory nerve conduction, reflecting a nonlenght-dependent pattern of peripheral axon degeneration, should be considered the hallmark of ganglionopathies. The evidence of central sensory pathway impairment, which allows to localize the pathology to the dorsal root ganglion neurons, could be better confirmed by cervical magnetic resonance imaging, which showed a diffuse hyperintensity in the posterior columns in all patients, than by somatosensory evoked potentials, which were undetectable in most of the patients. Few patients showed an impairment of individual motor nerves, which appeared more severe in paraneoplastic associated ganglionopathies. Neurophysiological abnormalities did not appear significantly changed at the 4-year follow-up. We emphasize that distinct abnormalities allow to differentiate ganglionopathies from axonal sensory neuropathies on routine neurophysiological examination.