Peripheral inflammation exacerbates α-synuclein toxicity and neuropathology in Parkinson's models.

AIMS: Parkinson's disease and related disorders are devastating neurodegenerative pathologies. Since α-synuclein was identified as a main component of Lewy bodies and neurites, efforts have been made to clarify the pathogenic mechanisms of α-synuclein's detrimental effects. α-synuclein oligomers are the most harmful species and may recruit and activate glial cells. Inflammation is emerging as a bridge between genetic susceptibility and environmental factors co-fostering Parkinson's disease. However, direct evidence linking inflammation to the harmful activities of α-synuclein oligomers or to the Parkinson's disease behavioural phenotype is lacking. METHODS: To clarify whether neuroinflammation influences Parkinson's disease pathogenesis, we developed: (i) a 'double-hit' approach in C57BL/6 naive mice where peripherally administered lipopolysaccharides were followed by intracerebroventricular injection of an inactive oligomer dose; (ii) a transgenic 'double-hit' model where lipopolysaccharides were given to A53T α-synuclein transgenic Parkinson's disease mice. RESULTS: Lipopolysaccharides induced a long-lasting neuroinflammatory response which facilitated the detrimental cognitive activities of oligomers. LPS-activated microglia and astrocytes responded differently to the oligomers with microglia activating further and acquiring a pro-inflammatory M1 phenotype, while astrocytes atrophied. In the transgenic 'double-hit' A53T mouse model, lipopolysaccharides aggravated cognitive deficits and increased microgliosis. Again, astrocytes responded differently to the double challenge. These findings indicate that peripherally induced neuroinflammation potentiates the α-synuclein oligomer's actions and aggravates cognitive deficits in A53T mice. CONCLUSIONS: The fine management of both peripheral and central inflammation may offer a promising therapeutic approach to prevent or slow down some behavioural aspects in α-synucleinopathies.

Review: PrP 106-126 - 25 years after.

A quarter of a century ago, we proposed an innovative approach to study the pathogenesis of prion disease, one of the most intriguing biomedical problems that remains unresolved. The synthesis of a peptide homologous to residues 106-126 of the human prion protein (PrP106-126), a sequence present in the PrP amyloid protein of Gerstmann-Sträussler-Scheinker syndrome patients, provided a tractable tool for investigating the mechanisms of neurotoxicity. Together with several other discoveries at the beginning of the 1990s, PrP106-126 contributed to underpin the role of amyloid in the pathogenesis of protein-misfolding neurodegenerative disorders. Later, the role of oligomers on one hand and of prion-like spreading of pathology on the other further clarified mechanisms shared by different neurodegenerative conditions. Our original report on PrP106-126 neurotoxicity also highlighted a role for programmed cell death in CNS diseases. In this review, we analyse the prion research context in which PrP106-126 first appeared and the advances in our understanding of prion disease pathogenesis and therapeutic perspectives 25 years later.

Clinical and biomarker profiling of prodromal Alzheimer's disease in workpackage 5 of the Innovative Medicines Initiative PharmaCog project: a 'European ADNI study'.

BACKGROUND: In the field of Alzheimer's disease (AD), the validation of biomarkers for early AD diagnosis and for use as a surrogate outcome in AD clinical trials is of considerable research interest. OBJECTIVE: To characterize the clinical profile and genetic, neuroimaging and neurophysiological biomarkers of prodromal AD in amnestic mild cognitive impairment (aMCI) patients enrolled in the IMI WP5 PharmaCog (also referred to as the European ADNI study). METHODS: A total of 147 aMCI patients were enrolled in 13 European memory clinics. Patients underwent clinical and neuropsychological evaluation, magnetic resonance imaging (MRI), electroencephalography (EEG) and lumbar puncture to assess the levels of amyloid ß peptide 1-42 (Aß42), tau and p-tau, and blood samples were collected. Genetic (APOE), neuroimaging (3T morphometry and diffusion MRI) and EEG (with resting-state and auditory oddball event-related potential (AO-ERP) paradigm) biomarkers were evaluated. RESULTS: Prodromal AD was found in 55 aMCI patients defined by low Aß42 in the cerebrospinal fluid (Aß positive). Compared to the aMCI group with high Aß42 levels (Aß negative), Aß positive patients showed poorer visual (P = 0.001), spatial recognition (P < 0.0005) and working (P = 0.024) memory, as well as a higher frequency of APOE4 (P < 0.0005), lower hippocampal volume (P = 0.04), reduced thickness of the parietal cortex (P < 0.009) and structural connectivity of the corpus callosum (P < 0.05), higher amplitude of delta rhythms at rest (P = 0.03) and lower amplitude of posterior cingulate sources of AO-ERP (P = 0.03). CONCLUSION: These results suggest that, in aMCI patients, prodromal AD is characterized by a distinctive cognitive profile and genetic, neuroimaging and neurophysiological biomarkers. Longitudinal assessment will help to identify the role of these biomarkers in AD progression.

Neuronal cell adhesion genes and antidepressant response in three independent samples.

Drug-effect phenotypes in human lymphoblastoid cell lines recently allowed to identify CHL1 (cell adhesion molecule with homology to L1CAM), GAP43 (growth-associated protein 43) and ITGB3 (integrin beta 3) as new candidates for involvement in the antidepressant effect. CHL1 and ITGB3 code for adhesion molecules, while GAP43 codes for a neuron-specific cytosolic protein expressed in neuronal growth cones; all the three gene products are involved in synaptic plasticity. Sixteen polymorphisms in these genes were genotyped in two samples (n=369 and 90) with diagnosis of major depressive episode who were treated with antidepressants in a naturalistic setting. Phenotypes were response, remission and treatment-resistant depression. Logistic regression including appropriate covariates was performed. Genes associated with outcomes were investigated in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) genome-wide study (n=1861) as both individual genes and through a pathway analysis (Reactome and String databases). Gene-based analysis suggested CHL1 rs4003413, GAP43 rs283393 and rs9860828, ITGB3 rs3809865 as the top candidates due to their replication across the largest original sample and the STAR*D cohort. GAP43 molecular pathway was associated with both response and remission in the STAR*D, with ELAVL4 representing the gene with the highest percentage of single nucleotide polymorphisms (SNPs) associated with outcomes. Other promising genes emerging from the pathway analysis were ITGB1 and NRP1. The present study was the first to analyze cell adhesion genes and their molecular pathways in antidepressant response. Genes and biomarkers involved in neuronal adhesion should be considered by further studies aimed to identify predictors of antidepressant response.

Effectiveness of anthracycline against experimental prion disease in Syrian hamsters.

Prion diseases are transmissible neurodegenerative conditions characterized by the accumulation of protease-resistant forms of the prion protein (PrP), termed PrPres, in the brain. Insoluble PrPres tends to aggregate into amyloid fibrils. The anthracycline 4'-iodo-4'-deoxy-doxorubicin (IDX) binds to amyloid fibrils and induces amyloid resorption in patients with systemic amyloidosis. To test IDX in an experimental model of prion disease, Syrian hamsters were inoculated intracerebrally either with scrapie-infected brain homogenate or with infected homogenate coincubated with IDX. In IDX-treated hamsters, clinical signs of disease were delayed and survival time was prolonged. Neuropathological examination showed a parallel delay in the appearance of brain changes and in the accumulation of PrPres and PrP amyloid.

Stem cell paracrine effect and delivery strategies for spinal cord injury regeneration.

Spinal cord injury (SCI) is a complicated neuropathological condition that results in functional dysfunction and paralysis. Various treatments have been proposed including drugs, biological factors and cells administered in several ways. Stem cell therapy offers a potentially revolutionary mode to repair the damaged spinal cord after injury. Initially, stem cells were considered promising for replacing cells and tissue lost after SCI. Many studies looked at their differentiation to replace neuronal and glial cells for a better functional outcome. However, it is becoming clear that different functional improvements recognized to stem cells are due to biomolecular activities by the transplanted stem cells rather than cell replacement. This review aimed to discuss the paracrine mechanisms for tissue repair and regeneration after stem cell transplantation in SCI. It focuses on stem cell factor production, effect in tissue restoration, and novel delivery strategies to use them for SCI therapy.

Mesenchymal stem cells encapsulated into biomimetic hydrogel scaffold gradually release CCL2 chemokine in situ preserving cytoarchitecture and promoting functional recovery in spinal cord injury.

Spinal cord injury (SCI) is an acute neurodegenerative disorder caused by traumatic damage of the spinal cord. The neuropathological evolution of the primary trauma involves multifactorial processes that exacerbate the pathology, worsening the neurodegeneration and limiting neuroregeneration. This complexity suggests that multi-therapeutic approaches, rather than any single treatment, might be more effective. Encouraging preclinical results indicate that stem cell-based treatments may improve the disease outcome due to their multi-therapeutic ability. Mesenchymal Stem Cells (MSCs) are currently considered one of the most promising approaches. Significant improvement in the behavioral outcome after MSC treatment sustained by hydrogel has been demonstrated. However, it is still not known how hydrogel contribute to the delivery of factors secreted from MSCs and what factors are released in situ. Among different mediators secreted by MSCs after seeding into hydrogel, we have found CCL2 chemokine, which could account for the neuroprotective mechanisms of these cells. CCL2 secreted from human MSCs is delivered efficaciously in the lesioned spinal cord acting not only on recruitment of macrophages, but driving also their conversion to an M2 neuroprotective phenotype. Surprisingly, human CCL2 delivered also plays a key role in preventing motor neuron degeneration in vitro and after spinal cord trauma in vivo, with a significant improvement of the motor performance of the rodent SCI models.

Time-course of c-Jun N-terminal kinase activation after cerebral ischemia and effect of D-JNKI1 on c-Jun and caspase-3 activation.

The c-Jun N-terminal kinase (JNK) signaling pathway plays a critical role in ischemic brain injury. The d-retro-inverso form of c-Jun N-terminal kinase-inhibitor (D-JNKI1), a cell-permeable inhibitor of JNK, powerfully reduces neuronal death induced by permanent and transient ischemia, even when administered 6 h after the ischemic insult, offering a clinically relevant window. We investigated the JNK molecular cascade activation in rat cerebral ischemia and the effects of D-JNKI1 on this cascade. c-Jun activation starts after 3 h after ischemia and peaks at 6 h in the ischemic core and in the penumbra at 1 h and at 6 h respectively. The 6 h c-Jun activation peak correlates well with that of P-JNK. We also examined the activation of the two direct JNK activators, MAP kinase kinase 4 (MKK4) and MAP kinase kinase 7 (MKK7). MKK4 showed the same time course as JNK in both core and penumbra, reaching peak activation at 6 h. MKK7 did not show any significant increase of phosphorylation in either core or penumbra. D-JNKI1 markedly prevented the increase of P-c-Jun in both core and penumbra and powerfully inhibited caspase-3 activation in the core. These results confirm that targeting the JNK cascade using the TAT cell-penetrating peptide offers a promising therapeutic approach for ischemia, raising hopes for human neuroprotection, and elucidates the molecular pathways leading to and following JNK activation.

Associations of the plasma interleukin 6 (IL-6) levels with disability and mortality in the elderly in the Treviso Longeva (Trelong) study.

IL-6 expression is regulated by the interplay of several transcriptional and hormonal factors, including sex steroids and glucocorticoids. In late life IL-6 expression increases as a result from loss of the normally inhibiting sex steroids. IL-6 is one of several proinflammatory cytokines. It has been proposed that many chronic inflammatory diseases are the result of a dysregulation of IL-6 expression. In this work we demonstrate that increased IL-6 levels in elderly are associated with higher disability and mortality, also independently of age and comorbidity.

The Treviso Longeva (Trelong) study: a biomedical, demographic, economic and social investigation on people 70 years and over in a typical town of North-East of Italy.

Longevity is a complex process resulting from genetic and environmental factors, as well as their interaction. These factors are poorly understood, and the comparison among health status, socio-economics, demographic and other characteristics of the elderly people can help in understanding these complex interactions. Such an interdisciplinary approach is necessary to allow an appropriate evaluation of longevity. Here we report the methodology and the first results of a representative study performed in 2003-2004 on people of 70 years and over, living in a typical town of North-East of Italy. In the research we collected biomedical, demographic, socio-economic and quality of life (QoL) data.

Amyloid in Alzheimer's disease and prion-related encephalopathies: studies with synthetic peptides.

Deposition of amyloid-beta protein (beta A) in brain parenchyma and vessel walls is a major pathological feature of Alzheimer's disease (AD). In prion-related encephalopathies (PRE), too, an altered form of prion protein (PrPsc) forms amyloid fibrils and accumulates in the brain. In both conditions the amyloid deposition is accompanied by nerve cell loss, whose pathogenesis and molecular basis are not understood. Neuropathological, genetic and biochemical studies indicate a central role of beta A in the AD pathogenesis. Synthetic peptides homologous to beta A and its fragments contribute to investigate the mechanisms of beta A deposit formation and the role played by beta A in AD pathogenesis. The physicochemical studies on the beta-sheet conformation and self-aggregation properties of beta A peptides indicate the conditions and the factors influencing the formation of beta A deposits. The neurotoxic activity of beta A and its fragments support the causal relationship between beta A deposits and the neuropathological events in AD. Numerous studies were performed to clarify the mechanism of neuronal death induced by exposure to beta A peptides. A similar approach has been used to investigate the role of PrPsc in PRE; in these diseases, the association between accumulation of PrPsc and neuropathology is evident and numerous data indicate that PrPsc itself might be the infectious agent responsible for disease transmission. Thus, PrP peptides were used to investigate the pathogenic role of PrPsc in PRE and the conformational change responsible for the conversion PrPc to PrPsc that makes the molecule apparently infectious. In particular, we synthesized a peptide homologous to residues 106-126, an integral part of all abnormal PrP isoforms that accumulate in the brain of subjects' PRE. This peptide is fibrillogenic, has secondary structure largely composed of beta-sheet and proteinase-resistant properties, is neurotoxic and induces astrogliosis. In this review, we summarize and compare the data obtained with beta A and PrP peptides and analyze the significance in terms of amyloidogenic proteins and neurodegeneration.

Tetracycline affects abnormal properties of synthetic PrP peptides and PrP(Sc) in vitro.

Prion diseases are characterized by the accumulation of altered forms of the prion protein (termed PrP(Sc)) in the brain. Unlike the normal protein, PrP(Sc) isoforms have a high content of beta-sheet secondary structure, are protease-resistant, and form insoluble aggregates and amyloid fibrils. Evidence indicates that they are responsible for neuropathological changes (i.e. nerve cell degeneration and glial cell activation) and transmissibility of the disease process. Here, we show that the antibiotic tetracycline: (i) binds to amyloid fibrils generated by synthetic peptides corresponding to residues 106-126 and 82-146 of human PrP; (ii) hinders assembly of these peptides into amyloid fibrils; (iii) reverts the protease resistance of PrP peptide aggregates and PrP(Sc) extracted from brain tissue of patients with Creutzfeldt-Jakob disease; (iv) prevents neuronal death and astrocyte proliferation induced by PrP peptides in vitro. NMR spectroscopy revealed several through-space interactions between aromatic protons of tetracycline and side-chain protons of Ala(117-119), Val(121-122) and Leu(125) of PrP 106-126. These properties make tetracycline a prototype of compounds with the potential of inactivating the pathogenic forms of PrP.

PEN-2 gene mutation in a familial Alzheimer's disease case.

Genetic evidence indicates a central role of cerebral accumulation of beta-amyloid (Abeta) in the pathogenesis of Alzheimer's disease (AD). Beside presenilin 1 and 2, three other recently discovered proteins (Aph 1, PEN 2 and nicastrin) are associated with gamma-secretase activity, the enzymatic complex generating Abeta. Alterations in genes encoding these proteins were candidates for a role in AD. The PEN 2 gene was examined for unknown mutations and polymorphisms in sporadic and familial Alzheimer patients. Samples from age-matched controls (n=253), sporadic AD (SAD, n=256) and familial AD (FAD, n=140) were screened with DHPLC methodology followed by sequencing. Scanning the gene identified for the first time a missense mutation (D90N) in a patient with FAD. Three intronic polymorphisms were also identified, one of which had a higher presence of the mutated allele in AD subjects carrying the allele epsilon4 of apolipoprotein E than controls. The pathogenic role of the PEN-2 D90N mutation in AD is not clear, but the findings might lead to new studies on its functional and genetic role.

Central endotoxin induces different patterns of interleukin (IL)-1 beta and IL-6 messenger ribonucleic acid expression and IL-6 secretion in the brain and periphery.

Centrally injected endotoxin induced high levels of interleukin (IL)-6 in serum, but the mechanisms of this induction and the signal conveying the information from the brain to the periphery are not yet known. To help characterize the pathway of centrally mediated induction of IL-6 in periphery, the cytokine levels were measured in rat serum and cerebrospinal fluid at different times after intracerebro-ventricular endotoxin (LPS, 2.5 micrograms/rat). In the same experiments, IL-6 and IL-1 beta messenger RNA (mRNA) expression, measured by Northern blot analysis, were evaluated in the periphery (adrenals, lymph nodes, and mononuclear cells) and brain (hypothalamus, hippocampus and striatum). In serum, IL-6 levels were highest after 2h; then they rapidly decreased. IL-6 mRNA showed the same time-course in adrenals and lymph nodes. The pattern in the central nervous system was different: in the cerebrospinal fluid, IL-6 was detectable starting from 2h, reaching a plateaux at 4-8h and remaining detectable until 16 h. IL-6 mRNA expression in the brain areas showed a similar time-course, reaching a maximum at 4-8 h. IL-1 beta mRNA induction started at the same time in brain and periphery, i.e. 1 h after LPS, but the maximal effect was reached at 2 h in mononuclear cells, adrenals, and lymph nodes, and at 8 h in brain regions. The results indicate that circulating IL-6 induced by central LPS is produced mainly peripherally and that synthesis of IL-6 and IL-1 beta are regulated differently in the brain and periphery.

Interferon-gamma potentiates interleukin (IL)-6 and tumor necrosis factor-alpha but not IL-1beta induced by endotoxin in the brain.

Because interferon-gamma (IFN gamma) is present in the central nervous system during neurologic diseases associated with inflammation, its effect on endotoxin-induced cytokines was studied. Cerebrospinal fluid (CSF) and serum levels of interleukin (IL)-1beta, IL-6, and tumor necrosis factor-alpha (TNF alpha), their messenger RNA expression in brain areas (hypothalamus, hippocampus, and striatum) and in spleen were evaluated 2 and 8 h after endotoxin [lipopolysaccharide (LPS), 25 microg/rat i.c.v.], IFN gamma (2.5 microg/rat i.c.v.) or after their coadministration in rats. CSF and serum IL-1beta levels were increased by LPS alone and IFN gamma coadministration did not furtherly increase them. IFN gamma potentiated LPS effect on IL-6 and TNF alpha levels in both CSF and serum. LPS and IFN-gamma coadministration did not alter IL-1beta messenger RNA expression induced by LPS in brain areas and in spleen, but it potentiated that of IL-6 and TNF alpha. The present in vivo data show that i.c.v. coadministration of LPS and IFN gamma results in a potentiation of cytokine production (IL-6 and TNF alpha) which may trigger a cascade of events relevant to neurodegenerative processes. This action is independent of IL-1beta because the production of this cytokine is not altered by IFN gamma treatment.

Deprivation of growth hormone-releasing hormone early in the rat's neonatal life permanently affects somatotropic function.

This work investigated in rats whether passive immunization against the endogenous GHRF in the early postnatal period led to permanent alterations of somatotropic function, similar to those observed in several human growth disorders, e.g. constitutional growth delay (CGD). On postnatal days 1, 2, 4, 6, 8, and 10, rats were given an anti-GHRF-serum (GHRH-Ab, 100 microliters/rat, sc) and were tested 1, 30, and 60 days after this treatment for basal and GHRH-stimulated GH secretion both in vivo and in vitro. GHRH-Ab reduced both basal and GHRF-stimulated GH secretion at all intervals and induced marked and chronic impairment of growth rate. The following differences were observed in the GHRH-Ab treated rats compared to normal rabbit serum-treated controls: 1) GH biosynthesis (incorporation of L-[3H]leucine into the electrophoretic band of GH): reduction of about 70%, 1 day but not 30 days after treatment; 2) Pituitary weight: significant reduction in absolute weight (30-40%) at all posttreatment intervals, and relative weight, 1 and 30 days after treatment. 3) Pituitary GH concentration: significant reduction in GH content (about 40%) but not concentration, at all posttreatment intervals; 4) Percentage of somatotrophs (immunocytochemistry): about 40% reduction 1 day, but not 30 and 60 days after treatment; 5) Hypothalamic somatostatin messenger RNA (mRNA) levels in situ hybridization): selective reduction (40%) in the periventricular nucleus 1 day but not 30 days after treatment; 6) Hypothalamic somatostatin cell number (immunocytochemistry): no significant changes in any hypothalamic area at any interval; 7) Pituitary somatostatin binding (in situ autoradiography): significant reduction, 1 day and 30 days after treatment; 8) Somatostatin inhibition of GH release "in vitro": somatostatin effect on GH release was reduced 30 days after treatment. These and previous data indicate that: 1) Transient deprivation of GHRF in the immediate postnatal period of the rat leads to permanent impairment of growth rate and somatotropic function; 2) GHRF deficiency itself or through reduction of GH secretion impairs somatostatin functions temporarily in the hypothalamus and permanently in the pituitary; 3) This rat model may mimic some forms of growth disorders in humans and holds promise as useful tools for investigating the underlying pathophysiological mechanisms.

Anti-amyloidogenic activity of tetracyclines: studies in vitro.

Cerebral deposition of beta-amyloid is a major neuropathological feature in Alzheimer's disease. Here we show that tetracyclines, tetracycline and doxycycline, classical antibiotics, exhibit anti-amyloidogenic activity. This capacity was determined by the exposure of beta 1-42 amyloid peptide to the drugs followed by the electron microscopy examination of the amyloid fibrils spontaneously formed and quantified with thioflavine T binding assay. The drugs reduced also the resistance of beta 1-42 amyloid fibrils to trypsin digestion. Tetracyclines not only inhibited the beta-amyloid aggregates formation but also disassembled the pre-formed fibrils. The results indicate that drugs with a well-known clinical profile, including activity in the central nervous system, are potentially useful for Alzheimer's therapy.

Neurodegenerative Effects Induced by Chronic Infusion of Quinolinic Acid in Rat Striatum and Hippocampus.

In this study we examined whether the potency of quinolinic acid (Quin) in inducing neurodegeneration in vivo was dependent on the exposure time of the tissue to the excitotoxin. The effect of chronic infusion of Quin into rat striatum and hippocampus was examined at the light microscopic level and by cell count on 40 microm Cresyl violet stained brain sections. Continuous infusion was at a constant speed (0.5 microl/h) for various times (15 h - 2 weeks) by osmotic minipumps (Alzet 2002). No build up of [3H]Quin occurred in the tissue during infusion; this was assessed by measuring the radioactivity 3 - 14 days after minipump placement. Intrastriatal infusion of 6 and 10 nmol/h Quin, but not of nicotinic acid, for 1 week induced a dose-dependent neurodegeneration (70 and 90% loss of neurons, respectively, compared to the contralateral striatum) extending 1.2 - 2 mm from the centre of the injection. The onset of the neurotoxicity caused by 10 nmol/h Quin was >24 h. One week's infusion of 4 nmol/h Quin did not induce neurotoxicity, but a 40% drop of neurons, compared to the contralateral side, occurred after 2 weeks. One week's intrahippocampal infusion of 2.4 and 6 nmol/h Quin, but not of nicotinic acid, caused a dose-dependent neurodegeneration with a radius of approximately 1 - 1.5 mm around the injection track. The onset of the neurotoxicity induced by 2.4 nmol/h Quin was < 15 h. The pattern of nerve cell loss induced by 1.2 nmol/h Quin after 1 week (CA4 cells lost in 50% of the rats) did not differ from that observed after 2 weeks of infusion. Nerve cell loss caused by Quin in the striatum and in the hippocampus was restricted to the injected area and antagonized by coinfusion with d(-)-2-amino-7-phosphonoheptanoic and kynurenic acids in molar ratios of 1:0.1 and 1:3, respectively. These data show that Quin's potency in inducing neurodegeneration in the striatum, but not in the hippocampus, depends on the exposure time of the tissue to the excitotoxin. In addition, neurodegeneration is induced faster by Quin in the hippocampus than in the striatum. The usefulness of this model to study the sequelae of the neurotoxic process in vivo will be discussed.

New mutation (R42P) of the parkin gene in the ubiquitinlike domain associated with parkinsonism.

OBJECTIVE: To investigate the association between parkin gene mutations and parkinsonism in an Italian family in which three of 12 siblings born to first-degree consanguineous parents had early-onset parkinsonism. BACKGROUND: Several deleting or truncating mutations as well as missense mutations of the parkin gene were associated with early-onset parkinsonism. METHOD: Three brothers were examined clinically at several stages of the disease. Single-strand conformational polymorphism analysis was done on the parkin gene of 32 members of the family. Samples showing mobility shifts were considered for mutation analysis. RESULTS: Direct DNA sequencing revealed a novel homozygous amino acid substitution, Arg42Pro, in all three patients compared with a control DNA sample. The mutation occurred in the ubiquitinlike domain at the N-terminal of the protein. The patients did not display the clinical hallmarks previously seen with parkin mutations and were indistinguishable from patients with sporadic PD. CONCLUSIONS: These findings confirm the recessive character of parkin mutations causing early-onset parkinsonism and the essential role of the ubiquitinlike region, highly conserved among species, and in accordance with the proposed parkin function.

Long-term acetyl-L-carnitine treatment in Alzheimer's disease.

In a double-blind, placebo-controlled, parallel-group, randomized clinical trial, we studied the efficacy of long-term (1-year) oral treatment with acetyl-L-carnitine in 130 patients with a clinical diagnosis of Alzheimer's disease. We employed 14 outcome measures to assess functional and cognitive impairment. After 1 year, both the treated and placebo groups worsened, but the treated group showed a slower rate of deterioration in 13 of the 14 outcome measures, reaching statistical significance for the Blessed Dementia Scale, logical intelligence, ideomotor and buccofacial apraxia, and selective attention. Adjusting for initial scores with analysis of covariance, the treated group showed better scores on all outcome measures, reaching statistical significance for the Blessed Dementia Scale, logical intelligence, verbal critical abilities, long-term verbal memory, and selective attention. The analysis for patients with good treatment compliance showed a greater drug benefit than for the overall sample. Reported adverse events were relatively mild, and there was no significant difference between the treated and placebo groups either in incidence or severity.