Presymptomatic Testing for Huntington's Disease in Mexico: 28 Years of Experience.

INTRODUCTION: Huntington's disease (HD) is a genetic neurodegenerative disorder with dominant inheritance. Our center in Mexico City has offered presymptomatic testing (PT) since 1995. OBJECTIVE: To describe the main clinical and demographic characteristics of at-risk HD individuals who applied to the PT program, the reasons for seeking it, and the molecular results. METHODS: A cross-sectional study was conducted with sociodemographic and clinical data of all PT applicants from 1995-2023. Reasons for seeking PT were assessed using a modified questionnaire. In addition, anxiety, and depressive symptoms before and after PT were evaluated with Beck's instruments; cognitive impairment (CI) was assessed with the Mini-Mental State Examination (MMSE) and molecular results. RESULTS: 214 people applied for PT (2.1% of the at-risk population identified in our center); 63% were women (mean age of 37.11 years). 204 (95.3%) were accepted and 190 received results. 70% indicated that the main reason for applying for PT was to inform their offspring about the risk of inheriting HD. Significant differences were observed in the reasons for seeking PT by age group. Although some subjects received treatment, Beck's instrument scores did not indicate special attention or pharmacological treatment. The MMSE showed probable CI in 20 subjects. Of those who received results, 37% were carriers of a full penetrance allele. CONCLUSION: Our center has the only formal PT program for HD in Mexico. The reasons for seeking PT are varied and age-related. Although PT is offered to all subjects at risk for HD, uptake remains low.

Clinical and Molecular Features of First Mexican Friedreich's Ataxia Patients with Compound Heterozygous FXN Mutations.

BACKGROUND: Friedreich's ataxia (FRDA) is caused by homozygous GAA repeat expansions or compound heterozygous (CH) mutations in FXN gene. Its broad clinical spectrum makes it difficult to identify, thus an accurate diagnosis can only be made by genetic testing. OBJECTIVE: This study aims to present data on FXN variants observed in patients with sporadic or recessive ataxia, including detailed data of the first CH Mexican patients. MATERIALS AND METHODS: One hundred and eight patients with recessive or sporadic cerebellar ataxia were referred to our institution between 2009 and 2019 for FXN molecular testing. This was achieved using a combined methodology of triplet repeat-primed PCR (polymerase chain reaction), long PCR, FXN sequencing and multiplex-ligation probe-amplification. RESULTS: Eighteen patients had a homozygous FXN genotype; whereas five were CH patients with a slow progression and phenotypic variability, including a late-onset case with spastic paraparesis, and a Charcot-Marie-Tooth-like case. CONCLUSIONS: These first Mexican CH patients pose important implications for genetic counseling and FRDA management.

Immunomodulatory effect and clinical outcome in Parkinson's disease patients on levodopa-pramipexole combo therapy: A two-year prospective study.

Parkinson's disease (PD), the second most frequent neurodegenerative disease, has been linked to increased central and peripheral inflammation. Although the response of the immune system to dopaminergic treatment remains to be fully understood, dopaminergic agonists are known to exhibit immunoregulatory properties which may, at least in part, explain their therapeutic effect in PD. This highlights the need of analyzing immune parameters in longitudinal studies on PD patients receiving specific therapeutic regimes. In this work, PD patients were included in a two-year prospective study comparing the effect of levodopa alone and a levodopa/pramipexole combo therapy on several regulatory and pro-inflammatory immune cell populations. We demonstrated that PD patients show decreased circulating levels of several important regulatory subpopulations, as determined by flow cytometry. Notably, when administered alone, levodopa decreased the levels of functional Bregs and SLAMF1+ tolerogenic DCs and increased the levels of total and HLA-DR+ classical monocytes, while the pramipexole/levodopa combo may promote Treg- and tolerogenic DC-mediated regulatory responses. These results suggest that a regime based on levodopa alone may promote a pro-inflammatory-type response in PD patients, but when combined with pramipexole, it promotes a clinically beneficial regulatory-type environment.

Theory of mind impairment in Huntington's disease patients and their relatives.

Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. METHODS We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. RESULTS The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. CONCLUSION The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

Theory of mind impairment in Huntington's disease patients and their relatives / Déficits en teoría de la mente en pacientes con enfermedad de Huntington y sus familiares

ABSTRACT Huntington disease (HD) is an autosomal dominant genetic disorder characterized by movement disorders, cognitive impairment, and psychiatric symptoms. Relatives of HD patients experience a great burden as the latter suffer from altered social conduct and deterioration of interpersonal relationships. Theory of mind (ToM) is the ability to attribute mental states (to oneself and others). Deficits in ToM are thought to have a role in the changes in empathy and interpersonal difficulties that HD patients face. Methods: We conducted a cross sectional study to compare ToM task scores of patients with mild to moderate HD, their relatives (spouse or at-risk first-degree relative with a negative gene test) and controls.Individuals with dementia or depression were excluded. The ToM test battery included Spanish versions of the Reading Mind in the Eyes Test (RMET), Happé's Strange Stories (Social and Physical Stories subtests) and the Hinting Task. Results: The series comprised 12 HD patients, 12 relatives and 12 controls. The HD patients showed lower affective ToM scores than controls (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Cognitive ToM tasks scores were lower in HD patients than controls as well (Happé's Social Stories 9 [2.6] vs 13 [1.9], p = 0.001; the Hinting Task 13.6 [3.4] vs 17.5 [4.0], p = 0.009). In the Hinting Task, HD relatives had lower scores in than controls (13 [3.2] vs 17.5 [4.0], p = 0.009) and similar scores to controls in the rest of the battery. Conclusion: The HD patients with mild to moderate disease severity and their relatives show ToM deficits.

RESUMEN La enfermedad de Huntington (EH) es una enfermedad genética autosómica dominante caracterizada por trastornos del movimiento, deterioro cognitivo y síntomas psiquiátricos. Los familiares de las personas con EH experimentan gran carga dado que los pacientes sufren de conducta social alterada y deterioro de relaciones interpersonales. La Teoría de la mente (ToM) consiste en la habilidad para atribuir estados mentales (a uno mismo o a otros). Se piensa que déficits en ToM tienen un rol en los cambios en empatia y en las dificultades interpersonales que los pacientes con EH enfrentan. Métodos: Condujimos un estudio transversal para comparar el desempeño en puntajes de tareas de ToM en pacientes con EH leve a moderada, sus familiares (pareja o familiar en riesgo con prueba genética negativa) y controles sanos. Se excluyó a sujetos con demencia o depresión. La batería de pruebas de ToM incluyó versiones en español de la prueba de lectura de la mente en los ojos (RMET), Historias Extrañas de Happé (subpruebas Social y Física) y Hinting Task. Resultados: La serie consistió de 12 pacientes con EH, 12 familiares y 12 controles. Los pacientes con EH mostraron puntajes menores de tareas de ToM afectiva que los controles (RMET 19 [3.5] vs 23.9 [2.7], p = 0.016). Los puntajes de tareas de ToM cognitiva fueron inferiores a los controles en los pacientes con EH (Historias Sociales de Happé 9 [2.6] vs 13 [1.9], p = 0.001; Hinting task 13.6 [3.4] vs 175 [4.0], p = 0.009). En la Hinting task los familiares de pacientes con EH mostraron puntajes inferiores que los de los controles (13 [3.2] vs 175 [4.0], p = 0.009) y puntajes similares a aquellos de los controles en el resto de la batería. Conclusión: Los pacientes con EH con enfermedad leve a moderada y sus familiares muestran déficits en tareas de ToM.

Expression of Dopamine Receptors in Immune Regulatory Cells.

OBJECTIVE: Parkinson's disease (PD) patients are usually treated with L-dopa and/or dopaminergic agonists, which act by binding five types of dopaminergic receptors (DRD1-DRD5). Peripheral immune cells are known to express dopamine receptors on their membrane surface, and therefore they could be directly affected by the treatment. Regulatory cells are the main modulators of inflammation, but it is not clear whether dopaminergic treatment could affect their functions. While only regulatory T cells (Tregs) have been proved to express dopamine receptors, it is not known whether other regulatory cells such as CD8regs, regulatory B cells (Bregs), tolerogenic dendritic cells, and intermediate monocytes also express them. METHODS: The expression of dopamine receptors in Tregs, CD8regs, Bregs, tolerogenic dendritic cells, and intermediate monocytes was herein evaluated. cDNA from 11 PD patients and 9 control subjects was obtained and analyzed. RESULTS: All regulatory cell populations expressed the genes coding for dopamine receptors, and this expression was further corroborated by flow cytometry. These findings may allow us to propose regulatory populations as possible targets for PD treatment. CONCLUSIONS: This study opens new paths to deepen our understanding on the effect of PD treatment on the cells of the regulatory immune response.

Is the Hypointensity in Motor Cortex the Hallmark of Amyotrophic Lateral Sclerosis?

BACKGROUND: Amyotrophic lateral sclerosis (ALS) is a devastating disease that targets motor neurons. Upper motor neurons degeneration is pathologically characterized by brain iron accumulation. Signal attenuation in the shape of a ribbon at the posterior border of the precentral gyrus can be observed on conventional magnetic resonance imaging (MRI) sequences including T2-weighted sequence. METHODS: With the aim to know the qualities of this potential marker of ALS, we conducted a prospective study. Patients with definite ALS in the age range of 40-70 years and healthy controls underwent 3T brain MRI using a standardized sequence. A second MRI was performed 18 months later under the same conditions in the patients with ALS. RESULTS: Most of the patients with ALS (91.66%) exhibited a "black ribbon" (BR) with an average area of 79.98 mm3. Signal attenuation discriminated ALS with a mean value of 63.97 arbitrary units (AU) on the left BR (95% CI: 60.67-67.27), a mean value of 59.15 AU (95% CI: 54.78-63.53) on the right BR, and a significant difference with control subjects presenting a mean value of 107.85 AU (p < 0.001). The optimal cut-off point for differentiating patients with ALS from controls (sensitivity, 0.92; specificity, 0.93) was 83 AU. Forced vital capacity and muscle strength in the contralateral upper extremity were significantly correlated with the ribbon intensity in ALS. Patients who underwent a second study exhibited significant changes in the BR related to the rapid evolution of the disease. CONCLUSIONS: This marker represents a valuable tool for the selection of candidates and their follow-up in clinical trials.

Paraoxonase-1 polymorphisms and cerebral ischemic stroke: a pilot study in mexican patients.

BACKGROUND: The serum paraoxonase-1 (PON1) associated to HDL presents two common polymorphisms in the positions 192 and 55. These polymorphisms are considered determinant of the capacity of HDL to protect LDL from their oxidative modification. In this context, the PON1 genotype has been associated with cardiovascular diseases, including stroke. OBJECTIVE: To determine the allelic and genotypic frequencies of PON1 L55M and Q192R as well as the enzymatic activities of PON1 in subjects with and without atherothrombotic stroke. METHODS: There were included 28 people with atherothrombotic stroke and 29 without stroke. The genotyping was carried out by PCR-RFLP and the phenotyping by measurement of the activities of paraoxonase and arylesterase in serum. RESULTS: For the polymorphism Q192R, the allelic frequencies (Q/R) were 0.46/0.54 and 0.48/0.52 (p= 0.843) for the control group and the group with stroke, respectively. While for the polymorphism L55M, the allelic frequencies (L/M) were 0.81/0.19 for the control group, and 0.78/0.22 for the group with stroke (p= 0.610). The activity levels of paraoxonase were not significantly different between the control and stroke groups (450 vs. 348 UI/mL, p= 0.093) While the activity levels of arylesterase were significantly different between the studied groups (90 vs. 70 UI/mL, p= 0.001); however, upon adjustment by multiple linear regression, it was not longer significant. CONCLUSION: The polymorphisms Q192R and L55M, and the paraoxonase activity of PON1 are not risk factors for atherothrombotic stroke according to the results of this study.

INTRODUCCIÓN: La paraoxonasa-1 (PON1) sérica asociada a las HDL presenta dos polimorfismos comunes en las posiciones 192 y 55. Estos polimorfismos se consideran determinantes para la capacidad de las HDL de proteger a las LDL de su modificación oxidativa. En este contexto, el genotipo de PON1 se ha asociado con enfermedades cerebrovasculares, que incluyen el infarto cerebral. OBJETIVO: Determinar las frecuencias alélicas y genotípicas de PON1-L55M y PON1- Q192R, así como las actividades enzimáticas de PON1 en sujetos con y sin infarto cerebral aterotrombótico. MÉTODOS: Se incluyeron 28 personas con infarto cerebral aterotrombótico y 29 sin infarto. Las genotipificaciones se realizaron mediante PCR-RFLP y las fenotipificaciones mediante la medición de las actividades paraoxonasa y arilesterasa en suero. RESULTADOS: Para el polimorfismo Q192R, las frecuencias alélicas (Q/R) fueron 0.46/0.54 y 0.48/0.52 (p= 0.843) para el grupo control y el grupo con infarto, respectivamente. Mientras que para el polimorfismo L55M, las frecuencias alélicas (L/M) fueron 0.81/0.19 para el grupo control y 0.78/0.22 para el grupo con infarto (p= 0.610). Los niveles de actividad paraoxonasa no fueron significativamente diferentes entre los grupos control y con infarto (450 vs. 348 Ul/mL, p= 0.093). Mientras que los niveles de actividad arilesterasa fueron significativamente diferentes entre los grupos estudiados (90 vs. 70 Ul/mL, p= 0.001), sin embargo, al ajustarla por regresión lineal múltiple, dejo de ser significativa. CONCLUSIÓN: Los polimorfismos Q192R y L55M, y la actividad paraoxonasa de la PON1 no son factores de riesgo para el infarto cerebral aterotrombótico en este estudio.

Paraoxonase-1 polymorphisms and cerebral ischemic stroke: a pilot study in mexican patients / Caracterización polimórfica de la paraoxonasa-1 en el infarto cerebral aterotrombótico de una poblacion mexicana: estudio piloto

Abstract Background: The serum paraoxonase-1 (PON1) associated to HDL presents two common polymorphisms in the positions 192 and 55. These polymorphisms are considered determinant of the capacity of HDL to protect LDL from their oxidative modification. In this context, the PON1 genotype has been associated with cardiovascular diseases, including stroke. Objective: To determine the allelic and genotypic frequencies of PON1 L55M and Q192R as well as the enzymatic activities of PON1 in subjects with and without atherothrombotic stroke. Methods: There were included 28 people with atherothrombotic stroke and 29 without stroke. The genotyping was carried out by PCR-RFLP and the phenotyping by measurement of the activities of paraoxonase and arylesterase in serum. Results: For the polymorphism Q192R, the allelic frequencies (Q/R) were 0.46/0.54 and 0.48/0.52 (p= 0.843) for the control group and the group with stroke, respectively. While for the polymorphism L55M, the allelic frequencies (L/M) were 0.81/0.19 for the control group, and 0.78/0.22 for the group with stroke (p= 0.610). The activity levels of paraoxonase were not significantly different between the control and stroke groups (450 vs. 348 UI/mL, p= 0.093) While the activity levels of arylesterase were significantly different between the studied groups (90 vs. 70 UI/mL, p= 0.001); however, upon adjustment by multiple linear regression, it was not longer significant. Conclusion: The polymorphisms Q192R and L55M, and the paraoxonase activity of PON1 are not risk factors for atherothrombotic stroke according to the results of this study.

Resumen Introducción: La paraoxonasa-1 (PON1) sérica asociada a las HDL presenta dos polimorfismos comunes en las posiciones 192 y 55. Estos polimorfismos se consideran determinantes para la capacidad de las HDL de proteger a las LDL de su modificación oxidativa. En este contexto, el genotipo de PON1 se ha asociado con enfermedades cerebrovasculares, que incluyen el infarto cerebral. Objetivo: Determinar las frecuencias alélicas y genotípicas de PON1-L55M y PON1- Q192R, así como las actividades enzimáticas de PON1 en sujetos con y sin infarto cerebral aterotrombótico. Métodos: Se incluyeron 28 personas con infarto cerebral aterotrombótico y 29 sin infarto. Las genotipificaciones se realizaron mediante PCR-RFLP y las fenotipificaciones mediante la medición de las actividades paraoxonasa y arilesterasa en suero. Resultados: Para el polimorfismo Q192R, las frecuencias alélicas (Q/R) fueron 0.46/0.54 y 0.48/0.52 (p= 0.843) para el grupo control y el grupo con infarto, respectivamente. Mientras que para el polimorfismo L55M, las frecuencias alélicas (L/M) fueron 0.81/0.19 para el grupo control y 0.78/0.22 para el grupo con infarto (p= 0.610). Los niveles de actividad paraoxonasa no fueron significativamente diferentes entre los grupos control y con infarto (450 vs. 348 Ul/mL, p= 0.093). Mientras que los niveles de actividad arilesterasa fueron significativamente diferentes entre los grupos estudiados (90 vs. 70 Ul/mL, p= 0.001), sin embargo, al ajustarla por regresión lineal múltiple, dejo de ser significativa. Conclusión: Los polimorfismos Q192R y L55M, y la actividad paraoxonasa de la PON1 no son factores de riesgo para el infarto cerebral aterotrombótico en este estudio.

Copper sulfate pretreatment prevents mitochondrial electron transport chain damage and apoptosis against MPP+-induced neurotoxicity.

Intrastriatal injection of 1-methyl-4-phenylpyridinium (MPP+) is considered a model to reproduce some biochemical alterations observed in Parkinson's disease (PD) patients. Among those alterations, inhibition of mitochondrial complex I activity, increased free radical production and reduced antioxidant responses have been reported. Copper (Cu) plays an important role in the metabolism and antioxidative responses through its participation as a cofactor in the cytochrome c oxidase enzyme (COX), Cu/Zn-superoxide dismutase (Cu/Zn-SOD), and metallothioneins. We tested the effect of copper sulfate (CuSO4) pretreatment on the mitochondrial electron transport chain (METC) in the striatum after MPP+ toxicity in rats. The results showed that the MPP+ intrastriatal injection reduced mitochondrial complex I, II, IV and V activities; while 10 µmol of CuSO4 pretreatment counteracted this damage. Activities of complexes I, II and IV, were coincident with ATP recovery. Moreover, Cu/Zn-SOD activity was reduced as a consequence of MPP+ damage; however, copper pre-treatment kept the striatal Cu/Zn-SOD activity unchanged in MPP+-damaged animals. We observed that MPP+ also reduced the metallothionein (MT) content and that CuSO4 pretreatment maintained baseline values. CuSO4 pretreatment also reduced the striatal caspase-3 and caspase-9 activities that were increased three days after MPP+-induced damage. The present study provided evidence that copper pretreatment reduced MPP+-induced apoptotic damage, probably through direct action on copper-dependent proteins or indirectly on proteins in the apoptotic pathway.

[Genetic factors associated with dementia in Parkinson's disease (PD)]. / Factores genéticos de la demencia en la enfermedad de Parkinson (EP).

Parkinson's disease (PD) is a neurodegenerative disorder characterized by motor and non-motor symptoms. Dementia is a frequent complication of idiopathic Parkinsonism or PD, usually occurring later in the protracted course of the illness. Some risk factors to develop dementia in PD are aging, severe Parkinson´s symptoms, rigid-akinetic form, hallucinations, and mild cognitive impairment documented at the first examinations. It is not yet clear if some genetic factors are either risk or protector for progression to dementia. In a review of the literature, we found that mutations in the alpha-synuclein gene are the most responsible for developing dementia, either from PARK1 or 4 mutations. GBA (glucocerebrosidase) is another accountable factor. However, the vast majority of patients suffer from non-Mendelian or complex forms of PD, which are likely caused by the combined effects of genetic and environmental factors. There is not until now a clear relation between some polymorphisms in candidate genes and cognitive deterioration, as many studies have not clearly identified this phenotype.

Serum leptin is associated with metabolic syndrome in obese Mexican subjects.

BACKGROUND: The metabolic syndrome (MetS) is a cluster of metabolic abnormalities including insulin resistance, dyslipidemia, high blood pressure, and abdominal adiposity. Obese patients develop leptin resistance, and an increased waist circumference (WC) due to deposition of abdominal fat. The aim of this study was to evaluate the association between circulating leptin levels and MetS among sample adult Mexican workers. METHOD: A total of 204 workers aged 20-56 were evaluated. Anthropometric index, blood pressure, fasting plasma glucose, and lipid profile were measured by spectrophotometric methods. Fasting insulin and leptin were measured by inmunoenzimatic methods. Furthermore, homeostasis model assessment for insulin resistance (HOMA-IR) was calculated. RESULTS: The prevalence of MetS according to the ATP-III criteria was 33.8% and leptin concentrations were 2.5 times higher in women than men. Subjects with MetS had higher levels of leptin (26.7 ± 13.7) compared with those without MetS (20.1 ± 13.9; P <0.001). Leptin increased significantly while BMI increased as well (normal 14.0 ± 8.9, overweight 22.7 ± 11.7 and obese 31.4 ± 14.6) in addition to other variables such as WC, HDL-C, insulin levels, and HOMA index. Each component of MetS was stratified by sex and submitted by linear regression with a 95% of accuracy. The 50% and 53% of the BMI is explained by the concentration of leptin in men and women, respectively (P < 0.001). CONCLUSION: This study found that leptin was associated with the MetS, especially in obesity and insulin resistance, indicating a high risk for university workers to develop hypertension, DM2, and cardiovascular disease.

Sub-chronic copper pretreatment reduces oxidative damage in an experimental Huntington's disease model.

Quinolinic acid (QUIN) striatal injection in rat reproduces the main neurochemical features of Huntington's disease (HD), including oxidative damage. In this study, we evaluated the effect of a copper (Cu) supplement in drinking water (90 ppm Cu, 28 days) on the QUIN-induced HD model in the rat. Copper exposure caused no signs of liver toxicity; however, it produced significant Cu accumulation in striatum. It is noteworthy that QUIN also caused increased striatal Cu content; when the supplement was administered to animals with QUIN-injury, an even higher metal striatal accumulation was observed. Cu pre-treatment preserved striatal gamma-aminobutyric acid (GABA) content, which was reduced by QUIN intrastriatal injection. Similarly, apomorphine-induced circling behavior was reduced in Cu-pretreated QUIN-damaged rats. Metal supplement in drinking water prevented both lipid peroxidation and reactive oxygen species (ROS) formation caused by QUIN in striatum. In Cu-treated groups, superoxide dismutase-1 (SOD1) activity showed a significant increase, while SOD2 activity was slightly enhanced. Although the pathophysiological role for higher Cu levels in patients with HD and in experimental models of the disease is not fully understood, results in the present study suggest that Cu oral intake stimulates anti-oxidant defenses, an effect that may be a potential factor for reducing the progression of HD.

Parahippocampal gray matter alterations in Spinocerebellar Ataxia Type 2 identified by voxel based morphometry.

Spinocerebellar Ataxia Type 2 (SCA2) is a genetic disorder causing cerebellar degeneration that result in motor and cognitive alterations. Voxel-based morphometry (VBM) analyses have found neurodegenerative patterns associated to SCA2, but they show some discrepancies. Moreover, behavioral deficits related to non-cerebellar functions are scarcely discussed in those reports. In this work we use behavioral and cognitive tests and VBM to identify and confirm cognitive and gray matter alterations in SCA2 patients compared with control subjects. Also, we discuss the cerebellar and non-cerebellar functions affected by this disease. Our results confirmed gray matter reduction in the cerebellar vermis, pons, and insular, frontal, parietal and temporal cortices. However, our analysis also found unreported loss of gray matter in the parahippocampal gyrus bilaterally. Motor performance test ratings correlated with total gray and white matter reductions, but executive performance and clinical features such as CAG repetitions and disease progression did not show any correlation. This pattern of cerebellar and non-cerebellar morphological alterations associated with SCA2 has to be considered to fully understand the motor and non-motor deficits that include language production and comprehension and some social skill changes that occur in these patients.

Plasma ceruloplasmin ferroxidase activity correlates with the nigral sonographic area in Parkinson's disease patients: a pilot study.

Increased area of the substantia nigra (SN) associated to iron deposition has been proposed as a specific marker for Parkinson's disease (PD). Echogenicity, assessed by transcranial sonography (TCS), has been used to measure such an iron deposition. On the other hand, ferroxidase activity is known to play a role in brain iron metabolism and thus could be involved in increased SN echogenicity of PD patients. The present study was conducted to search for a possible correlation between both markers: TCS of SN and plasma ferroxidase activity. Twenty-one PD patients and 13 healthy volunteers (HV) were included. Mean SN sonographic areas were 0.31 cm² for PD patients and 0.12 cm² for HV (P < 0.001), while plasma ferroxidase activity was reduced in PD patients (P < 0.001). Interestingly, plasma ferroxidase activity was inversely correlated with the SN size by TCS (R² = 0.31), suggesting a relationship between the two markers.

Low frequency of common LRRK2 mutations in Mexican patients with Parkinson's disease.

Mutations in leucine-rich repeat kinase 2 gene (LRRK2) account for as much as 5-6% of familial Parkinson's disease (PD) and 1-2% of sporadic PD. These mutations represent the most frequent cause of autosomal dominant PD, particularly in certain ethnic groups. In this first report concerning LRRK2 mutations in Mexican-mestizos, we screened 319 consecutive PD patients (186 males; 133 females; mean age at onset: 52.4 years) for LRRK2 mutations in exons 31 and 41 and for the mutation in exon 35, which produces the Y1699C substitution. Three (0.94%) patients, two with sporadic PD and one with familial PD (disease mean age at onset, 53.3 years), were heterozygous for LRRK2 mutations. Of these three, two patients had one of two different mutations in exon 31 (R1441G and R1441H, respectively); the other patient carried the G2019S mutation in exon 41. The Y1699C mutation was absent from this PD sample. Four additional subjects, unaffected relatives of one PD patient with a mutation in LRRK2, were subsequently genetically tested. None of the three LRRK2 mutations identified was present in 200 neurologically healthy Mexican control individuals. These findings have important implications for molecular testing of LRRK2 mutations in Mexican PD patients.

Clinical and genetic characteristics of Mexican Huntington's disease patients.

We report the characteristics of 691 Mexican patients with Huntington's disease (HD). These patients, representing 401 families, constitute the largest series of Mexican HD cases as yet described in the literature. We found the clinical characteristics of these patients to be similar to those of other populations, but we observed a higher frequency of infantile cases, a shorter disease duration and a lower suicide rate. In 626 cases, for which molecular analyses were available, CAG-trinucleotide expansion size ranged from 37-106 repeats. The large number of CAG repeats (19.04 +/- 3.02) in normal alleles and the presence of new mutations suggest that the overall prevalence of HD in the Mexican population could be expected to be within range of, or higher than, that reported for Europeans.

Free copper, ferroxidase and SOD1 activities, lipid peroxidation and NO(x) content in the CSF. A different marker profile in four neurodegenerative diseases.

The understanding of oxidative damage in different neurodegenerative diseases could enhance therapeutic strategies. Our objective was to quantify lipoperoxidation and other oxidative products as well as the activity of antioxidant enzymes and cofactors in cerebrospinal fluid (CSF) samples. We recorded data from all new patients with a diagnosis of either one of the four most frequent neurodegenerative diseases: Parkinson's disease (PD), Alzheimer's disease (AD), Huntington's disease (HD) and lateral amyotrophic sclerosis (ALS). The sum of nitrites and nitrates as end products of nitric oxide (NO) were increased in the four degenerative diseases and fluorescent lipoperoxidation products in three (excepting ALS). A decreased Cu/Zn-dependent superoxide dismutase (SOD) activity characterized the four diseases. A significantly decreased ferroxidase activity was found in PD, HD and AD, agreeing with findings of iron deposition in these entities, while free copper was found to be increased in CSF and appeared to be a good biomarker of PD.

Apolipoprotein E epsilon4 allele is associated with Parkinson disease risk in a Mexican Mestizo population.

We investigated the association between apolipoprotein E (APOE) alleles and genotypes and Parkinson disease (PD) in 229 unrelated Mexican Mestizo PD patients and 229 controls. Results showed that both APOE-epsilon4 allele and APOE epsilon4/epsilon3 genotype are associated with PD (OR = 1.736, P = 0.011; OR = 1.688, P = 0.019, respectively). Mean age at onset of PD was not associated to any APOE allele or genotype, but was significantly earlier in familial PD when compared to sporadic cases (P = 0.025).

Arginine, citrulline and nitrate concentrations in the cerebrospinal fluid from patients with acute hydrocephalus.

Citrulline and nitric oxide (NO) are synthesized by NO synthase (NOS) in a 1:1-stoichiometry. In this study, we determined by HPLC arginine and citrulline concentrations by fluorescence detection and nitrate levels by UV absorbance detection in the cerebrospinal fluid (CSF) from patients with acute hydrocephalus that underwent ventricular drainage. We found increased citrulline concentration (50.6+/-17.2 versus 20.9+/-2.0 microM) and decreased arginine/citrulline molar ratio (0.42+/-0.11 versus 1.12+/-0.16) in hydrocephalus patients, while arginine and nitrate concentrations and citrulline/nitrate molar ratio remained with little change. Citrulline has been determined as a marker of NOS activity in some studies, but it remains to be determined the extent at which this statement holds true, since other biochemical pathways also regulate the concentration of this amino acid. Our results suggest that citrulline is primarily synthesized from NOS in acute hydrocephalus. The evaluation of sample deproteinization by addition of methanol for the analysis of amino acids in CSF is also reported.