Multi-omics profiling of CSF from spinal muscular atrophy type 3 patients after nusinersen treatment: a 2-year follow-up multicenter retrospective study.

Spinal muscular atrophy (SMA) is a neurodegenerative disorder caused by mutations in the SMN1 gene resulting in reduced levels of the SMN protein. Nusinersen, the first antisense oligonucleotide (ASO) approved for SMA treatment, binds to the SMN2 gene, paralogue to SMN1, and mediates the translation of a functional SMN protein. Here, we used longitudinal high-resolution mass spectrometry (MS) to assess both global proteome and metabolome in cerebrospinal fluid (CSF) from ten SMA type 3 patients, with the aim of identifying novel readouts of pharmacodynamic/response to treatment and predictive markers of treatment response. Patients had a median age of 33.5 [29.5; 38.25] years, and 80% of them were ambulant at time of the enrolment, with a median HFMSE score of 37.5 [25.75; 50.75]. Untargeted CSF proteome and metabolome were measured using high-resolution MS (nLC-HRMS) on CSF samples obtained before treatment (T0) and after 2 years of follow-up (T22). A total of 26 proteins were found to be differentially expressed between T0 and T22 upon VSN normalization and LIMMA differential analysis, accounting for paired replica. Notably, key markers of the insulin-growth factor signaling pathway were upregulated after treatment together with selective modulation of key transcription regulators. Using CombiROC multimarker signature analysis, we suggest that detecting a reduction of SEMA6A and an increase of COL1A2 and GRIA4 might reflect therapeutic efficacy of nusinersen. Longitudinal metabolome profiling, analyzed with paired t-Test, showed a significant shift for some aminoacid utilization induced by treatment, whereas other metabolites were largely unchanged. Together, these data suggest perturbation upon nusinersen treatment still sustained after 22 months of follow-up and confirm the utility of CSF multi-omic profiling as pharmacodynamic biomarker for SMA type 3. Nonetheless, validation studies are needed to confirm this evidence in a larger sample size and to further dissect combined markers of response to treatment.

Biological determinants of blood-based cytokines in the Alzheimer's disease clinical continuum.

Converging translational and clinical research strongly indicates that altered immune and inflammatory homeostasis (neuroinflammation) plays a critical pathophysiological role in Alzheimer's disease (AD), across the clinical continuum. A dualistic role of neuroinflammation may account for a complex biological phenomenon, representing a potential pharmacological target. Emerging blood-based pathophysiological biomarkers, such as cytokines (Cyt) and interleukins (ILs), have been studied as indicators of neuroinflammation in AD. However, inconsistent results have been reported probably due to a lack of standardization of assays with methodological and analytical differences. We used machine-learning and a cross-validation-based statical workflow to explore and analyze the potential impact of key biological factors, such as age, sex, and apolipoprotein-E (APOE) genotype (the major genetic risk factor for late-onset AD) on Cyt. A set of Cyt was selected based on previous literature, and we investigated any potential association in a pooled cohort of cognitively healthy, mild cognitive impairment (MCI), and AD-like dementia patients. We also performed explorative analyses to extrapolate preliminary clinical insights. We found a robust sex effect on IL12 and an APOE-related difference in IL10, with the latter being also related to the presence of advanced cognitive decline. IL1ß was the variable most significantly associated with MCI-to-dementia conversion over a 2.5 year-clinical follow-up. Although preliminary, our data support further clinical research to understand whether plasma Cyt may represent reliable and noninvasive tools serving the investigation of neuroimmune and inflammatory dynamics in AD and to foster biomarker-guided pathway-based therapeutic approaches, within the precision medicine development framework.

α-Synuclein Heteromers in Red Blood Cells of Alzheimer's Disease and Lewy Body Dementia Patients.

BACKGROUND: Red blood cells (RBCs) contain the majority of α-synuclein (α-syn) in blood, representing an interesting model for studying the peripheral pathological alterations proved in neurodegeneration. OBJECTIVE: The current study aimed to investigate the diagnostic value of total α-syn, amyloid-ß (Aß1-42), tau, and their heteroaggregates in RBCs of Lewy body dementia (LBD) and Alzheimer's disease (AD) patients compared to healthy controls (HC). METHODS: By the use of enzyme-linked immunosorbent assays, RBCs concentrations of total α-syn, Aß1-42, tau, and their heteroaggregates (α-syn/Aß1-42 and α-syn/tau) were measured in 27 individuals with LBD (Parkinson's disease dementia, n = 17; dementia with Lewy bodies, n = 10), 51 individuals with AD (AD dementia, n = 37; prodromal AD, n = 14), and HC (n = 60). RESULTS: The total α-syn and tau concentrations as well as α-syn/tau heterodimers were significantly lower in the LBD group and the AD group compared with HC, whereas α-syn/Aß1-42 concentrations were significantly lower in the AD dementia group only. RBC α-syn/tau heterodimers had a higher diagnostic accuracy for differentiating patients with LBD versus HC (AUROC = 0.80). CONCLUSION: RBC α-syn heteromers may be useful for differentiating between neurodegenerative dementias (LBD and AD) and HC. In particular, RBC α-syn/tau heterodimers have demonstrated good diagnostic accuracy for differentiating LBD from HC. However, they are not consistently different between LBD and AD. Our findings also suggest that α-syn, Aß1-42, and tau interact in vivo to promote the aggregation and accumulation of each other.

Nusinersen treatment and cerebrospinal fluid neurofilaments: An explorative study on Spinal Muscular Atrophy type 3 patients.

The antisense oligonucleotide Nusinersen has been recently licensed to treat spinal muscular atrophy (SMA). Since SMA type 3 is characterized by variable phenotype and milder progression, biomarkers of early treatment response are urgently needed. We investigated the cerebrospinal fluid (CSF) concentration of neurofilaments in SMA type 3 patients treated with Nusinersen as a potential biomarker of treatment efficacy. The concentration of phosphorylated neurofilaments heavy chain (pNfH) and light chain (NfL) in the CSF of SMA type 3 patients was evaluated before and after six months since the first Nusinersen administration, performed with commercially available enzyme-linked immunosorbent assay (ELISA) kits. Clinical evaluation of SMA patients was performed with standardized motor function scales. Baseline neurofilament levels in patients were comparable to controls, but significantly decreased after six months of treatment, while motor functions were only marginally ameliorated. No significant correlation was observed between the change in motor functions and that of neurofilaments over time. The reduction of neurofilament levels suggests a possible early biochemical effect of treatment on axonal degeneration, which may precede changes in motor performance. Our study mandates further investigations to assess neurofilaments as a marker of treatment response.

Potential Diagnostic Value of Red Blood Cells α-Synuclein Heteroaggregates in Alzheimer's Disease.

A plethora of complex misfolded protein combinations have been found in Alzheimer disease (AD) brains besides the classical pathological hallmarks. Recently, α-synuclein (α-syn) and its heterocomplexes with amyloid-ß (Aß) and tau have been suggested to be involved in the pathophysiological processes of neurodegenerative diseases. These pathological features are not limited to the brain, but can be also found in peripheral fluids. In this respect, red blood cells (RBCs) have been suggested as a good model to investigate the biochemical alterations of neurodegeneration. Our aim is to find whether RBC concentrations of α-syn and its heterocomplexes (i.e., α-syn/Aß and α-syn/tau) were different in AD patients compared with healthy controls (HC). The levels of homo- and heteroaggregates of α-syn, Aß and tau, were analyzed in a cohort of AD patients at early stage either with dementia or prodromal symptoms (N = 39) and age-matched healthy controls (N = 39). All AD patients received a biomarker-based diagnosis (low cerebrospinal fluid levels of Aß peptide combined with high cerebrospinal fluid concentrations of total tau and/or phospho-tau proteins; alternatively, a positivity to cerebral amyloid-PET scan). Our results showed lower concentrations of α-syn and its heterocomplexes (i.e., α-syn/Aß and α-syn/tau) in RBCs of AD patients with respect to HC. RBC α-syn/Aß as well as RBC α-syn/tau heterodimers discriminated AD participants from HC with fair accuracy, whereas RBC α-syn concentrations differentiated poorly the two groups. Although additional investigations are required, these data suggest α-syn heteroaggregates in RBCs as potential tool in the diagnostic work-up of early AD diagnosis.

Amyotrophic Lateral Sclerosis and Oxidative Stress: A Double-Blind Therapeutic Trial After Curcumin Supplementation.

OBJECTIVE: To investigate the efficacy of curcumin oral supplementation (600 mg/day, Brainoil), a natural antioxidant compound, in Amyotrophic Lateral Sclerosis (ALS). METHODS: Patients were randomized into two groups: Group A received placebo for 3 months, then Brainoil for the following 3 months, Group B took Brainoil for 6 months. The evaluations were conducted at basal (T0), after 3 months of double blinded Brainoil or placebo treatment (T1), and after the 3 month open-label phase (T2). Clinical evaluations and oxidative stress biomarkers, including oxidative protein products (AOPPs), ferric reducing ability (FRAP), total thiols (T-SH) and lactate, were evaluated, compared to a control group, during an incremental forearm exercise test. RESULTS: Over the entire study Group B showed a stable score of the ALS-FRS-r which decreased in Group A (p<0.01), in parallel with a reduction of AOPPs (p<0.01) which was not detected into Group A. Also FRAP exercise values remained stable in Group B, while in Group A they were reduced without treatment at T1 (0.05T0 exercise lactate was lower compared to Group A (p<0.01). Compared to controls, the whole ALS population showed a greater oxidative stress (p<0.001), those treated with curcumin (Group B) exhibiting decreased exercise AOPPs at T2 with values approaching those of controls. CONCLUSION: Although further studies are needed to confirm these data, treatment with curcumin shows encouraging results indicating a slight slowdown in disease progression, improving aerobic metabolism and oxidative damage, this also contributing to deepen knowledge into the pathogenic mechanisms of ALS.

α-Synuclein Heterocomplexes with ß-Amyloid Are Increased in Red Blood Cells of Parkinson's Disease Patients and Correlate with Disease Severity.

Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), ß-amyloid1-42 (Aß1-42) and tau, in both brain and peripheral tissues. In addition to oligomers, the role of the interactions of α-syn with Aß or tau has gradually emerged. Nevertheless, despite intensive research, NDs have no accepted peripheral markers for biochemical diagnosis. In this respect, Red Blood Cells (RBCs) are emerging as a valid peripheral model for the study of aging-related pathologies. Herein, a small cohort (N = 28) of patients affected by Parkinson's disease (PD) and age-matched controls were enrolled to detect the content of α-syn (total and oligomeric), Aß1-42 and tau (total and phosphorylated) in RBCs. Moreover, the presence of α-syn association with tau and Aß1-42 was explored by co-immunoprecipitation/western blotting in the same cells, and quantitatively confirmed by immunoenzymatic assays. For the first time, PD patients were demonstrated to exhibit α-syn heterocomplexes with Aß1-42 and tau in peripheral tissues; interestingly, α-syn-Aß1-42 concentrations were increased in PD subjects with respect to healthy controls (HC), and directly correlated with disease severity and motor deficits. Moreover, total-α-syn levels were decreased in PD subjects and inversely related to their motor deficits. Finally, an increase of oligomeric-α-syn and phosphorylated-tau was observed in RBCs of the enrolled patients. The combination of three parameters (total-α-syn, phosphorylated-tau and α-syn-Aß1-42 concentrations) provided the best fitting predictive index for discriminating PD patients from controls. Nevertheless further investigations should be required, overall, these data suggest α-syn hetero-aggregates in RBCs as a putative tool for the diagnosis of PD.

α-Synuclein Aggregated with Tau and ß-Amyloid in Human Platelets from Healthy Subjects: Correlation with Physical Exercise.

The loss of protein homeostasis that has been associated with aging leads to altered levels and conformational instability of proteins, which tend to form toxic aggregates. In particular, brain aging presents characteristic patterns of misfolded oligomers, primarily constituted of ß-amyloid (Aß), tau, and α-synuclein (α-syn), which can accumulate in neuronal membranes or extracellular compartments. Such aging-related proteins can also reach peripheral compartments, thus suggesting the possibility to monitor their accumulation in more accessible fluids. In this respect, we have demonstrated that α-syn forms detectable hetero-aggregates with Aß or tau in red blood cells (RBCs) of healthy subjects. In particular, α-syn levels and its heteromeric interactions are modulated by plasma antioxidant capability (AOC), which increases in turn with physical activity. In order to understand if a specific distribution of misfolded proteins can occur in other blood cells, a cohort of human subjects was enrolled to establish a correlation among AOC, the level of physical exercise and the concentrations of aging-related proteins in platelets. The healthy subjects were divided depending on their level of physical exercise (i.e., athletes and sedentary subjects) and their age (young and older subjects). Herein, aging-related proteins (i.e., α-syn, tau and Aß) were confirmed to be present in human platelets. Among such proteins, platelet tau concentration was demonstrated to decrease in athletes, while α-syn and Aß did not correlate with physical exercise. For the first time, α-syn was shown to directly interact with Aß and tau in platelets, forming detectable hetero-complexes. Interestingly, α-syn interaction with tau was inversely related to plasma AOC and to the level of physical activity. These results suggested that α-syn heterocomplexes, particularly with tau, could represent novel indicators to monitor aging-related proteins in platelets.

α-Synuclein Aggregates with ß-Amyloid or Tau in Human Red Blood Cells: Correlation with Antioxidant Capability and Physical Exercise in Human Healthy Subjects.

Neurodegenerative disorders (NDs) are characterized by abnormal accumulation/misfolding of specific proteins, primarily α-synuclein (α-syn), ß-amyloid1-42 (Aß), and tau, in both brain and peripheral tissue. In addition to homo-oligomers, the role of α-syn interactions with Aß or tau has gradually emerged. The altered protein accumulation has been related to both oxidative stress and physical activity; nevertheless, no correlation among the presence of peripheral α-syn hetero-aggregates, antioxidant capacity, and physical exercise has been discovered as of yet. Herein, the content of α-syn, Aß, tau, and of their heterocomplexes was determined in red blood cells (RBCs) of healthy subjects (sedentary and athletes). Such parameters were related to the extent of the antioxidant capability (AOC), a key marker of oxidative stress in aging-related pathologies, and to physical exercise, which is known to play an important preventive role in NDs and to modulate oxidative stress. Tau content and plasma AOC toward hydroxyl radicals were both reduced in older or sedentary subjects; in contrast, α-syn and Aß accumulated in elderly subjects and showed an inverse correlation with both hydroxyl AOC and the level of physical activity. For the first time, α-syn heterocomplexes with Aß or tau were quantified and demonstrated to be inversely related to hydroxyl AOC. Furthermore, α-syn/Aß aggregates were significantly reduced in athletes and inversely correlated with physical activity level, independent of age. The positive correlation between antioxidant capability/physical activity and reduced protein accumulation was confirmed by these data and suggested that peripheral α-syn heterocomplexes may represent new indicators of ND-related protein misfolding.

A single center study: Aß42/p-Tau181 CSF ratio to discriminate AD from FTD in clinical setting.

Abnormal levels of beta amyloid (Aß42) and tau protein concentrations in the cerebral spinal fluid (CSF) have been largely described in Alzheimer's disease (AD). Thus, CSF analysis of these biomarkers has been incorporated in recent AD diagnostic criteria, and it is increasingly performed for neurodegenerative dementia diagnostic workout in clinical setting. Nevertheless, the precise biomarkers CSF features in neurodegenerative dementia, either AD or Frontotemporal dementia (FTD), are still not fully clear today. This is mainly due to lack of CSF clear cutoff values due to a well-known intersite (but even intrasite) variability of CSF procedures, ranging from collection to analysis. Applying CSF biomarker ratios, rather than their single values could represent a useful tool, especially for the differential diagnosis of different forms of dementia. We explored clinical values of six CSF ratios (by combining Aß42 and tau) in order to better discriminate between AD and FTD; we identified Aß42/p-Tau181 ratio as a potential good candidate for helping differentiating AD from FTD in the clinical practice.

Gly482Ser PGC-1α Gene Polymorphism and Exercise-Related Oxidative Stress in Amyotrophic Lateral Sclerosis Patients.

The role of exercise in Amyotrophic lateral sclerosis (ALS) pathogenesis is controversial and unclear. Exercise induces a pleiotropic adaptive response in skeletal muscle, largely through the peroxisome proliferator-activated receptor γ coactivator 1α (PGC-1α), a transcriptional coactivator that regulates mitochondrial biogenesis and antioxidant defense mechanisms. It has been suggested that a Gly482Ser substitution in PGC-1α has functional relevance in human disorders and in athletic performance. To test this hypothesis, we examined the genotype distribution of PGC-1α Gly482Ser (1444 G > A) in ALS patients to evaluate whether or not the minor serine-encoding allele 482Ser is involved in oxidative stress responses during physical exercise. We genotyped 197 sporadic ALS patients and 197 healthy controls in order to detect differences in allelic frequencies and genotype distribution between the two groups. A total of 74 ALS patients and 65 controls were then comparatively assessed for plasmatic levels of the oxidative stress biomarkers, advanced oxidation protein products, ferric reducing ability and thiol groups. In addition a subgroup of 35 ALS patients were also assessed for total SOD and catalase plasmatic activity. Finally in 28 ALS patients we evaluated the plasmatic curve of the oxidative stress biomarkers and lactate during an incremental exercise test. No significant differences were observed in the genotype distribution and allelic frequency in ALS patients compared to the controls. We found significant increased advanced oxidation protein products (p < 0.001) and significant decreased ferric reducing ability (p < 0.001) and thiol groups (p < 0.001) in ALS patients compared to controls. When comparing different genotypes of PGC-1α, no relation between Gly482Ser polymorphism and oxidative stress biomarker levels was detected in resting conditions. On the other hand, when considering exercise performance, lactate levels were significantly higher (between p < 0.01 and p < 0.001) and greater protein oxidative products were found in AA (Ser482Ser) compared to GG (Gly482Gly) and GA (Gly482Ser) ALS patients. Our findings highlight the importance and confirm the involvement of oxidative stress in ALS pathogenesis. Although not associated with 1444 G > A SNP, ALS patients with Gly482Ser allelic variant show increased exercise-related oxidative stress. This thus highlights the possible role of this antioxidant defense transcriptional coactivator in ALS.

Methylation analysis of multiple genes in blood DNA of Alzheimer's disease and healthy individuals.

We collected blood DNA from 120 late-onset Alzheimer's disease (AD) patients and 115 healthy matched controls and analysed the methylation levels of genes involved in amyloid-beta peptide production (PSEN1 and BACE1), in DNA methylation (DNMT1, DNMT3A and DNMT3B), and in one-carbon metabolism (MTHFR), searching for correlation with age and gender, with biomarkers of one-carbon metabolism (plasma homocysteine, and serum folate and vitamin B12 levels), and with disease status (being healthy or having AD). We also evaluated the contribution of the APOE ϵ4 allele, the major late-onset AD genetic risk factor, to the studied gene methylation levels. All the genes showed low mean methylation levels (<5%) in both AD and control DNA, no difference between groups, and no correlation with the studied biomarkers, except for MTHFR that showed methylation levels ranging from 5% to 75%, and correlation with circulating biomarkers of one-carbon metabolism. However, mean MTHFR methylation levels were similar between groups (31.1% in AD and 30.7% in controls, P=0.58). Overall, present data suggest that none of the studied regions is differently methylated in blood DNA between AD and control subjects.

Evaluating the SERCA2 and VEGF mRNAs as Potential Molecular Biomarkers of the Onset and Progression in Huntington's Disease.

Abnormalities of intracellular Ca2+ homeostasis and signalling as well as the down-regulation of neurotrophic factors in several areas of the central nervous system and in peripheral tissues are hallmarks of Huntington's disease (HD). As there is no therapy for this hereditary, neurodegenerative fatal disease, further effort should be made to slow the progression of neurodegeneration in patients through the definition of early therapeutic interventions. For this purpose, molecular biomarker(s) for monitoring disease onset and/or progression and response to treatment need to be identified. In the attempt to contribute to the research of peripheral candidate biomarkers in HD, we adopted a multiplex real-time PCR approach to analyse the mRNA level of targeted genes involved in the control of cellular calcium homeostasis and in neuroprotection. For this purpose we recruited a total of 110 subjects possessing the HD mutation at different clinical stages of the disease and 54 sex- and age-matched controls. This study provides evidence of reduced transcript levels of sarco-endoplasmic reticulum-associated ATP2A2 calcium pump (SERCA2) and vascular endothelial growth factor (VEGF) in peripheral blood mononuclear cells (PBMCs) of manifest and pre-manifest HD subjects. Our results provide a potentially new candidate molecular biomarker for monitoring the progression of this disease and contribute to understanding some early events that might have a role in triggering cellular dysfunctions in HD.

Lack of association between nuclear factor erythroid-derived 2-like 2 promoter gene polymorphisms and oxidative stress biomarkers in amyotrophic lateral sclerosis patients.

Oxidative stress involvement has been strongly hypothesized among the possible pathogenic mechanisms of motor neuron degeneration in amyotrophic lateral sclerosis (ALS). The intracellular redox balance is finely modulated by numerous complex mechanisms critical for cellular functions, among which the nuclear factor erythroid-derived 2-like 2 (NFE2L2/Nrf2) pathways. We genotyped, in a cohort of ALS patients (n = 145) and healthy controls (n = 168), three SNPs in Nrf2 gene promoter: -653 A/G, -651 G/A, and -617 C/A and evaluated, in a subset (n = 73) of patients, advanced oxidation protein products (AOPP), iron-reducing ability of plasma (FRAP), and plasma thiols (-SH) as oxidative damage peripheral biomarkers. Nrf2 polymorphisms were not different among patients and controls. Increased levels of AOPP (P < 0.05) and decreased levels of FRAP (P < 0.001) have been observed in ALS patients compared with controls, but no difference in -SH values was found. Furthermore, no association was found between biochemical markers of redox balance and Nrf2 polymorphisms. These data confirm an altered redox balance in ALS and indicate that, while being abnormally modified compared to controls, the oxidative stress biomarkers assessed in this study are independent from the -653 A/G, -651 G/A, and -617 C/A Nrf2 SNPs in ALS patients.

Twinkle mutation in an Italian family with external progressive ophthalmoplegia and parkinsonism: a case report and an update on the state of art.

The objective is to describe the clinical phenotype and genetic basis of a family with autosomal dominant progressive external ophthalmoplegia and parkinsonism with a Twinkle mutation. The proband, an 82 years old female, reported since childhood bilateral eyelid ptosis, ophthalmoplegia, sensorineural hypoacusis, mild depression since she was 45, with a positive familiar anamnesis of eyelid ptosis (father, two sisters and a son). She developed mild bilateral parkinsonism with a moderate clinical response to levodopa. The (123)I-FP-CIT SCAN evidenced a marked bilateral putaminal reduction and moderate caudate uptake reduction. Her 79 years old sister reported eyelid ptosis since she was 45 with ophthalmoplegia and developed a mild bilateral rest and postural tremor with moderate right arm plastic hypertonia when she was 76. The parkinsonism was confirmed with (123)I-FP-CIT SCAN. One of the two sons presented eyelid ptosis since he was 30 years old, with peripheral neuropathy with biopsy evidence of myopathy. We identified a G1750A mutation in the c10orf2 gene in the three patients. Mitochondrial dysfunction has been implicated in the pathogenesis of sporadic, idiopathic Parkinson disease (PD). In some cases, mitochondrial DNA primary genetic abnormalities or more commonly secondary rearrangements due to polymerase gamma (POLG) gene mutation can directly cause parkinsonism. Parkinsonism has been reported as a rare symptom associated to Twinkle (c10orf2). Parkinsonism has to be investigated in patients with PEO with analysis of Twinkle mutation.

An "inflammatory" mitochondrial myopathy. A case report.

We describe a case of an adult male patient with progressive external ophthalmoplegia and upper limb weakness, who presented with an episode of sudden respiratory failure. Muscle biopsy showed ragged-red and COX-negative fibers associated with discrete inflammatory infiltrates and necrotizing features. Apart from artificial ventilator support, he was treated with intravenous immunoglobulins and carnitine, with excellent clinical outcome. Mitochondrial DNA analysis revealed the 3251A>G mutation, previously reported in association with rapidly progressive mitochondrial myopathy and respiratory failure. Our case expands the spectrum of this mutation and suggests a therapeutic attempt with immunoglobulins in mitochondrial patients with acute respiratory failure, at least when this mutation and/or muscle inflammation is present. Moreover, this case supports the idea of a pathologic inflammatory response induced by mitochondrial disease; such an abnormal response may be a contributory factor in disease progression or acute exacerbation typical of some mitochondrial diseases, but further studies are needed.

Nerve, muscle and heart acute toxicity following oxaliplatin and capecitabine treatment.

Capecitabine plus oxaliplatin combination (XELOX) is the first-line treatment in metastatic colorectal cancer. Here we report a case of acute, severe but substantially reversible, neuromuscular and cardiac toxicity following XELOX chemotherapy. Muscle biopsy findings were consistent with a toxic myopathy with necrotizing features and vacuolar changes; COX-negative fibers were also present. The time course could support a main role for capecitabine, which may have some neurotoxic effects (more frequently central), but a detrimental interaction between the two drugs cannot be ruled out and further studies are needed.

Nerve and muscle involvement in mitochondrial disorders: an electrophysiological study.

Involvement of the peripheral nervous system in mitochondrial disorders (MD) has been previously reported. However, the exact prevalence of peripheral neuropathy and/or myopathy in MD is still unclear. In order to evaluate the prevalence of neuropathy and myopathy in MD, we performed sensory and motor nerve conduction studies (NCS) and concentric needle electromyography (EMG) in 44 unselected MD patients. NCS were abnormal in 36.4% of cases, and were consistent with a sensori-motor axonal multineuropathy (multifocal neuropathy), mainly affecting the lower limbs. EMG evidence of myopathy was present in 54.5% of patients, again mainly affecting the lower limbs. Nerve and muscle involvement was frequently subclinical. Peripheral nerve and muscle involvement is common in MD patients. Our study supports the variability of the clinical expression of MD. Further studies are needed to better understand the molecular basis underlying the phenotypic variability among MD patients.

A novel mitochondrial tRNA(Ile) point mutation associated with chronic progressive external ophthalmoplegia and hyperCKemia.

We have sequenced the entire mitochondrial DNA (mtDNA) from a 54-year-old man with chronic progressive external ophthalmoplegia (PEO) and hyperCKemia. Muscle biopsy showed ragged red and SDH positive/COX negative fibres, and the biochemistry was suggestive mitochondrial respiratory chain dysfunction. Analysis of mtDNA revealed a heteroplasmic m. 4308G>A mutation in the transfer RNA isoleucine gene (MT-TI gene). Our report expands the genetic heterogeneity of PEO.

Clock T3111C and Per2 C111G SNPs do not influence circadian rhythmicity in healthy Italian population.

A possible relationship between human circadian rhythmicity and polymorphisms in clock genes have been documented. However, these data are controversial, and studies both corroborating and denying them have been reported. T3111C Clock polymorphism had been associated with the human evening preference, however, this association has not been confirmed. Moreover, C111G Per2 polymorphism has been associated with the "morning larks" chronotype in one study, not yet replicated. We have, therefore, performed this study to evaluate whether Per2 C111G and Clock T3111C polymorphisms might influence sleep circadian rhythmicity in a sample of 219 Italian volunteers. A possible interaction between these polymorphisms was also investigated. No differences in Per2 C111G and Clock T3111C allele and genotype frequencies were found, and none of the combined Clock T3111C-Per2 C11G genotypes resulted more frequent in one group compared to the others. Present results do not support a role of these polymorphisms in the circadian phenotypes.