Optimal excitation and emission wavelengths to analyze amino acids and optimize neurotransmitters quantification using precolumn OPA-derivatization by HPLC.

We describe an analytical methodology to obtain high sensitivity and better resolution through the study of fluorometric excitation (λex) and emission (λem) spectrum wavelengths of OPA-amino acids. The spectrum emission study revealed a maximum signal peak at 450 nm for aspartate and glutamine. For glycine, taurine, and GABA, the maximum signal peak was at 448 and for glutamate at 452 nm. The remaining amino acids analyzed showed a maximum emission around 450 nm. The best signal obtained within the spectrum excitation experiments was using 229- to 450-nm λex-λem. The drawbacks observed at these wavelengths were a baseline drift and negative peaks occurrence. Thus, the excitation wavelength of 240 nm was chosen (240- to 450-nm λex-λem) as a compromise between a very good signal response and a baseline stability to resolve the 18 amino acids studied. Furthermore, this protocol was properly validated. On the other hand, the elution gradient program used for neuroactive amino acids (aspartate, glutamate, glycine, taurine and GABA) showed separation to the baseline, in a 15-min run in all of them. Other amino acids, up to 18, also exhibited a very good separation in a 25-min run. In conclusion, we propose the use of 240- to 450-nm λex-λem wavelengths, in OPA-amino acids analysis, as the most suitable protocol to obtain the best signal response, maintaining an optimum chromatographic resolution.

Plasma progranulin levels in cortical dementia phenotypes with asymmetric perisylvian atrophy.

BACKGROUND AND PURPOSE: Decreased plasma progranulin levels are a very specific marker for the diagnosis of frontotemporal lobar degeneration (FTLD) caused by mutations in the progranulin gene (GRN). A frequent neuroimaging pattern in this type of dementia is asymmetric cortical atrophy. The aim of this study was to screen for GRN-linked FTLD in cases with different cortical dementia phenotypes and asymmetric perisylvian atrophy. METHODS: Progranulin plasma levels were analyzed in a variety of FTLD phenotypes (n = 71), dementia of the Alzheimer type (DAT) (n = 22) and probable Lewy body dementia (n = 8), both latter groups presented with asymmetric perisylvian atrophy. A group of elderly controls (n = 29) and DAT cases with symmetric atrophy (n = 33) were also analyzed. The GRN gene was sequenced in cases with lower plasma levels. RESULTS: Four cases with clinical FTLD phenotypes and plasma levels below 70 ng/ml were found to carry different GRN mutations: M1?, C139R, a point mutation in the splice donor site of intron 3 (A89VfsX41), and a deletion in exon 9 (A303AfsX57), this latter one being a new mutation. Thirteen cases with levels between 72 and 85 ng/ml did not show pathogenic changes in the GRN gene. None of the cases with asymmetric atrophy and clinical phenotypes other than FTLD had GRN mutations. CONCLUSIONS: Asymmetric perisylvian atrophy is not likely to predict progranulin-linked FTLD unless it is associated with a consistent FTLD clinical phenotype.

Seaweed as a source of novel nutraceuticals: sulfated polysaccharides and peptides.

Seaweeds and seaweed-derived products are underexploited marine bioresources and a source of natural ingredients for functional foods. Nutritional studies on seaweeds indicate that brown and red seaweeds possess a good nutritional quality and could be used as an alternative source of dietary fiber, protein, and minerals. Moreover, bioactive sulfated polysaccharides are the main components of soluble fiber in seaweeds and also bioactive peptides can be prepared from seaweed protein. This chapter gives an overview of the main biological properties of sulfated polysaccharides and peptides from brown and red seaweeds. Recent studies have provided evidence that sulfated polysaccharides from seaweeds can play a vital role in human health and nutrition. Besides, peptides derived from algal protein are most promising as antihypertensive agents. Further research work, especially in vivo studies, are needed in order to gain a better knowledge of the relation structure-function by which bioactive compounds from seaweeds exert their bioactivity.

Utilidad de los niveles de colestanol en el diagnóstico y seguimiento de los pacientes con xantomatosis cerebrotendinosa / Usefulness of cholestanol levels in the diagnosis and follow-up of patients with cerebrotendinous xanthomatosis

Introducción: la xantomatosis cerebro-tendinosa (XCT) es una enfermedad autosómica recesiva producida por un déficit de la enzima 27-hidroxilasa. Como consecuencia, existe una deficiencia de ácido quenodeoxicólico y una sobreproducción de colestanol que se deposita en los tejidos. Clínicamente cursa con cataratas, diarrea, xantomas y diferentes síntomas neurológicos. A pesar de que los niveles de colestanol se emplean en el diagnóstico de la XCT, se desconoce su correlación con la clínica y el pronóstico. Métodos: se han revisado 14 pacientes afectos de XCT, diagnosticados entre 1995 y 2008 en dos centros de referencia para el diagnóstico genético, en los que se había determinado el colestanol. Se han estudiado los principales datos demográficos, clínicos y terapéuticos y su posible relación con los niveles de colestanol. Resultados: la media de los niveles de colestanol al diagnóstico fue de 106μmol/ l. No se encontró ninguna relación entre el colestanol plasmático y los diferentes síntomas neurológicos, ni con el grado de discapacidad al diagnóstico medido mediante la EDSS. Tras la instauración del tratamiento se obtuvo una reducción significativa del colestanol plasmático en todos los casos (reducción media de 91μmol/ l en una media de 34 meses), a pesar de lo cual sólo un paciente se estabilizó clínicamente. Conclusiones: la presencia de niveles elevados de colestanol es muy útil para el diagnóstico de la XCT, pero no tiene valor pronóstico (no se correlaciona con la situación funcional). Su normalización no siempre se acompaña de una estabilización clínica, pero su monitorización puede ser útil para el ajuste del tratamiento (AU)

Introduction: cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disease caused by a deficiency of mitochondrial enzyme sterol 27-hydrolylase. Such a deficiency results in a reduced production of chenodeoxycholic acid and in an increased formation of cholestanol. It is clinically characterized by cataracts, diarrhoea, xanthomas, premature arteriosclerosis and a number of progressive neurological symptoms. Although cholestanol levels are used for the diagnosis of CTX, their correlation with the clinical symptoms and their prognostic usefulness have not been assessed so far. Methods: we reviewed 14 CTX patients diagnosed between 1995 and 2008 in two reference centres for the genetic diagnosis of this disorder, whose cholestanol levels had been recorded. We studied the main demographic, clinical and therapeutical data and their correlation with plasma cholestanol levels. Results: the average cholestanol level at diagnosis was 105.8μmol/l. These levels did not correlate with any neurological symptoms or with disability at diagnosis scored by the EDSS. After treatment, all patients achieved a significant reduction in plasma cholestanol levels (average reduction of 91μmol/l in an average follow-up of 34 months), although only one patient remained clinically stable. Conclusions: high cholestanol levels are very useful for diagnosis of CTX but they do not have a prognostic value (they do not correlate with severity). Normalisation of cholestanol levels is not always associated with clinical stabilisation. However, follow-up of cholestanol levels can be useful for the dose adjustment (AU)

Cerebrotendinous xanthomatosis in Spain: clinical, prognostic, and genetic survey.

BACKGROUND AND PURPOSE: Cerebrotendinous xanthomatosis (CTX) is a rare autosomal recessive disorder caused by mutations in the CYP27A1 gene resulting in sterol-27-hydroxylase deficiency. Current information about CTX is based mainly on case reports, with only few large series reported. Although perceived as a potentially treatable condition, efficacy of chenodeoxycholic acid plus statin therapy remains unclear. To perform a nationwide survey of confirmed cases, with a thorough analysis of genotype-phenotype data and prognostic factors. METHODS: Retrospective review of the clinical and epidemiological aspects and mutations of all the patients diagnosed since 1992 in the main reference centers for genetic testing of CTX in Spain. RESULTS: Twenty-five patients from 19 families were identified. An average delay of 19 years was observed between symptom onset and clinical diagnosis. Two main clinical subgroups were recognizable: a classic form (cerebellar and other supratentorial symptoms) and a spinal form (chronic myelopathy). Cholestanol levels did not correlate with clinical presentation, severity or response to therapy. Despite treatment, five patients died during follow-up, one to 4 years after diagnosis. Thirteen different mutations were identified, with a higher frequency of p.R395C in Northwestern Spain and p.R405W in Southern Spain. None of the mutations could be associated with a particular clinical feature combination or prognosis. CONCLUSIONS: This is the first nationwide extensive series of CTX reported in Spain. The higher number of cases in some areas suggests a possible founder effect. Spinal forms had a less severe prognosis. A delayed diagnosis could contribute to the lack of significant response to treatment.

A novel myelin protein zero (V136G) homozygous mutation causing late onset demyelinating polyneuropathy with brain white matter lesions.

Although less common than peripheral myelin protein 22 (PMP22) duplication, there are mutations in myelin protein zero (MPZ) responsible for Charcot-Marie-Tooth disease (CMT) with a number of different clinical profiles. We report here a novel MPZ homozygous mutation, with a peculiar pattern characterized by a late-onset demyelinating profile. In addition, the patient presented brain white matter lesions seemingly ascribable to the mutation.

[Usefulness of cholestanol levels in the diagnosis and follow-up of patients with cerebrotendinous xanthomatosis]. / Utilidad de los niveles de colestanol en el diagnóstico y seguimiento de los pacientes con xantomatosis cerebrotendinosa.

INTRODUCTION: cerebrotendinous xanthomatosis (CTX) is an autosomal recessive disease caused by a deficiency of mitochondrial enzyme sterol 27-hydrolylase. Such a deficiency results in a reduced production of chenodeoxycholic acid and in an increased formation of cholestanol. It is clinically characterized by cataracts, diarrhoea, xanthomas, premature arteriosclerosis and a number of progressive neurological symptoms. Although cholestanol levels are used for the diagnosis of CTX, their correlation with the clinical symptoms and their prognostic usefulness have not been assessed so far. METHODS: we reviewed 14 CTX patients diagnosed between 1995 and 2008 in two reference centres for the genetic diagnosis of this disorder, whose cholestanol levels had been recorded. We studied the main demographic, clinical and therapeutical data and their correlation with plasma cholestanol levels. RESULTS: the average cholestanol level at diagnosis was 105.8 µmol/l. These levels did not correlate with any neurological symptoms or with disability at diagnosis scored by the EDSS. After treatment, all patients achieved a significant reduction in plasma cholestanol levels (average reduction of 91 µmol/l in an average follow-up of 34 months), although only one patient remained clinically stable. CONCLUSIONS: high cholestanol levels are very useful for diagnosis of CTX but they do not have a prognostic value (they do not correlate with severity). Normalisation of cholestanol levels is not always associated with clinical stabilisation. However, follow-up of cholestanol levels can be useful for the dose adjustment.

Cerebrotendinous xanthomatosis: neuropathological findings.

Cerebrotendinous xanthomatosis is an inherited autosomal recessive lipid storage disease caused by a 27-hydroxylase enzyme deficiency, characterised clinically by tendon xanthomas, premature cataracts, chronic diarrhoea and progressive neurologic dysfunction. The disease is very uncommon and there are very few pathological descriptions. We report a 52-year-old male who presented with a neuropsychiatric disorder and cognitive decline. Despite treatment the patient developed optic atrophy, parkinsonism and dementia and died. The autopsy revealed a nonspecific brain and cerebellar atrophy. Under microscopic examination, lipid crystal clefts, neuronal loss, demyelination, reactive astrocytosis and perivascular macrophages were found. These findings suggest the limited reversibility of the disease, and its poor prognosis, specially if treatment is not started early.

[Clinical variability and diagnostic controversies in CADASIL]. / Variabilidad clínica y controversias diagnósticas en el CADASIL.

Cardiovascular risk factors are present in 85% of patients with stroke. However, up to 6%-15% of patients have a stroke secondary to unusual reasons such as systemic diseases, coagulation disorders, etc., and, in some cases, no reason can be identified even after performing an extensive study. This usually happens in young people. In this regard, the diagnostic screening must consider hereditary causes of stroke. CADASIL, an autosomal dominant brain white matter angiopathy, is emerging as a not uncommon cause of stroke with diverse clinical manifestations. Its clinical diagnosis is controversial because of the diverse role of the brain imaging study, the biopsy of the vessels of skin or other tissues and the DNA study.

Variabilidad clínica y controversias diagnósticas en el CADASIL / Clinical variability and diagnostic controversies in CADASIL

Los factores de riesgo cardiovascular están presentes en un 85% de los pacientes con enfermedad cerebrovascular. No obstante, en un 6-15% de los pacientes el ictus se debe a causas poco frecuentes como enfermedades sistémicas, alteraciones de la coagulación, etc. y, en algunos casos, a pesar de un estudio exhaustivo, no es posible identificar la causa del ictus. Esto ocurre con más frecuencia en pacientes jóvenes. En estos casos es necesario ampliar el estudio al examen de causas genéticas de la enfermedad cerebrovascular. CADASIL, una arteriopatía autosómica dominante que afecta a la sustancia blanca cerebral, está emergiendo como una causa no infrecuente de enfermedad cerebrovascular con diversas manifestaciones clínicas. Su diagnóstico es objeto de controversia por el diferente papel que tiene el estudio de imagen cerebral, el examen mediante biopsia de los vasos de la piel u otros órganos y el estudio genético molecular (AU)

Cardiovascular risk factors are present in 85% of patients with stroke. However, up to 6%-15% of patients have a stroke secondary to unusual reasons such as systemic diseases, coagulation disorders, etc., and, in some cases, no reason can be identified even after performing an extensive study. This usually happens in young people. In this regard, the diagnostic screening must consider hereditary causes of stroke. CADASIL, an autosomal dominant brain white matter angiopathy, is emerging as a not uncommon cause of stroke with diverse clinical manifestations. Its clinical diagnosis is controversial because of the diverse role of the brain imaging study, the biopsy of the vessels of skin or other tissues and the DNA study (AU)

Study of plasma antioxidant status in Alzheimer's disease.

To examine the plasma antioxidant status of Alzheimer's disease (AD) patients and to evaluate the influence of apolipoprotein E (APOE) genotype. There are reasons to suspect involvement of the free hydroxyl radical in the pathogenesis of AD. In contrast, studies in plasma of AD patients for the evaluation of levels of biomarkers of oxidation are controversial. Twenty AD patients diagnosed using the National Institute for Neurological Disorders/Alzheimer's Disease and Related Disorders (NINDS/ADRDA) criteria and 22 controls chosen amongst different subjects without cognitive damage. All the subjects--both AD patients and controls--were stratified by their APOE genotype (3/3, 3/4 or 4/4), which was determined by PCR. Plasma total antioxidant capacity (TAC) was determined using two complementary procedures: FRAP, which measures the ferric reduction capacity, and ABTS, which measures the radical scavenging capacity. In addition, 2-amino-adipic semialdehyde (2-AAS), a biomarker of protein oxidation, was evaluated. No significant difference was observed between the AD and control groups regarding plasma TAC. When the subjects were classified by their APOE genotype, significant differences were found in the APOE 4/4 group in the TCA determined by the FRAP method. Subjects with APOE genotype 4/4, which is the group with higher incidence in AD, showed lower antioxidant capacity of plasma. It is the first time that antioxidant capacity in plasma is evaluated in AD patients characterized by their APOE genotypes.

New V272A presenilin 1 mutation with very early onset subcortical dementia and parkinsonism.

In this report, we present the clinical and pathological details of a kindred of four individuals with a novel missense mutation (V272A) of the presenilin 1 gene (PSEN1) that experienced a subcortical dementia. The age of onset of symptoms ranged 26-36-year old, with an age at death of 36-46 years. Initial symptom was a marked mood disorder, with prominent parkinsonism in one case. The neuropsychological study, as well as the neuroimaging and PET in the proband were concordant with a subcortical dementia. The cerebral pathology showed in this patient, aside from the classical lesions of Alzheimer disease, Lewy bodies in cortex and substantia nigra, and widespread subcortical neuritic lesions. This clinical pattern and pathology expands the clinical spectrum of familial Alzheimer's disease and compel to include mutations of PSEN1 gene in the genetic study of subcortical dementia.

Oxígeno y oxidación I: especies reactivasde oxígeno y daño oxidativo de sustratos biológicos / Oxigen and oxidation I: reactive oxigen species and oxidative damage to biological substrates

La mayoría de los organismos eucarióticos necesitan el oxígeno para mantener una suficiente producción de energía para sobrevivir. Sin embargo, durante la utilización del oxígeno se originan especies reactivas intermedias, que resultan dañinas para los sustratos biológicos. Esto es lo que se denomina la paradoja aerobia. En el organismo humano existe un equilibrio entre estas especies reactivas de oxígeno y los sistemas de defensa antioxidante. Cuando este equilibrio se descompensa en favor de las especies reactivas de oxígeno se crea la situación de estrés oxidativo. Este desequilibrio se puede originar por una ingesta deficiente de antioxidantes naturales precedentes de la dieta o por situaciones de exposición a fuentes de especies radicales como son contaminación ambiental, estrés deportivo, enfermedades inflamatorias crónicas, radiaciones, etc. En esta revisión se describen la reactividad y la generación en situaciones fisiológicas de las distintas especies reactivas de oxígeno (el radical superóxido, el peróxido de hidrógeno, el oxígeno en estado triplete o excitado y el radical hidroxilo).Además, se estudia el mecanismo de oxidación de los sustratos biológicos (lípidos, proteínas y ácidos nucleicos) (AU)

Oxígeno y oxidación II: mecanismosde defensa antioxidante de los sistemas biológicos / Oxigen and oxidation II: antioxidant defense system of cellular organisms

En el organismo humano existe un equilibrio entre las especies reactivas oxidantes y los sistemas de defensa antioxidante. Cuando este equilibrio se descompensa en favor de las especies reactivas oxidantes se crea la situación de estrés oxidativo. La protección de los organismos celulares frente a los agentes oxidantes generados en el metabolismo aerobio está organizada en diferentes niveles de actuación. Las estrategias de defensa incluyen cuatro niveles de protección: prevención, interacción, reparación y adaptación. En esta revisión se realiza una descripción de los antioxidantes endógenos y dietéticos, teniendo en cuenta si la acción antioxidante se produce antes que el substrato se haya expuesto al estrés oxidativo o si la acción antioxidante sucede cuando el daño oxidativo se está produciendo o ya se ha producido. Se analiza el papel preventivo frente a la oxidación de los sistemas enzimáticos antioxidantes superóxido dismutasa, catalasa y glutation peroxidasa, de los sistemas proteicos que actúan como secuestrantes de metales como la transferrina, la ceruloplasmina y la hemoglobina y de los compuestos antioxidantes de origen dietético como los carotenoides, los flavonoides y la vitamina C. También se analiza el papel de interacción en el proceso de oxidación de los antioxidantes endógenos y dietéticos tanto de naturaleza hidrosoluble (vitamina C, ácido úrico y bilirrubina) como liposolubles (vitamina E, ubiquinol, carotenoides, flavonoides). Por último, se hace una mención a los procesos de reparación y adaptación en el sistema de defensa de protección frente al daño oxidativo de los sistemas biológicos (AU)

Apolipoprotein E Pittsburgh variant is not associated with the risk of late-onset Alzheimer's disease in a Spanish population.

The objective of this study was to assess whether the APOE(Pittsburgh) variant (APOE*4P) is associated to Alzheimer's disease (AD) in a population from Madrid (Spain). APOE*4P variant is caused by an exonic mutation which results in the substitution of proline-28 for leucine-28, only present in APOE*4 alleles. A study in a US population associated this APOE variant with an increased risk for AD, about five times higher than the risk attributed to APOE*4 carriers overall. One hundred and seventeen cases of late-onset AD and 121 matched control subjects from Madrid (Spain) were included. We studied the APOE polymorphism and the APOE*4P occurrence, by PCR and restriction analysis, and plasma lipids levels using standard protocols. As expected, APOE*4 was significantly overrepresented in AD cases. The APOE*4P mutation was observed in heterozygous state in four subjects, two AD (1.71%) and two controls (1.65%). APOE*4P did not confer higher risk for AD, globally (odds ratio 0.14; 95% confidence interval (CI) 0.02-1.12) or respect to APOE*4 carriers (odds ratio 0.14; 95% CI 0.02-1.24). There were no differences in plasma lipids levels among genotype groups. The mutation frequency in controls was higher in our sample than in the US one (1.65 and 0.18%, respectively; Fisher test P = 0.049). Our results suggest that this variant is not so uncommon in our population and is not directly related to AD, contrary to what has been proposed for other populations.

Event-related evoked potential P300 in frontotemporal dementia.

There are no studies on event-related cognitive potentials in frontotemporal dementia (FTD). In order to evaluate the aptitude and usefulness of the event-related P300 potential in this disease, we prospectively examined 60 cases: 11 patients with FTD diagnosed according to the Lund and Manchester criteria and Neary consensus criteria, 33 patients with a probable Alzheimer's disease diagnosis following NINCDS-ADRDA criteria, and 16 normal controls. P300 latency, amplitude and reaction time were recorded using an auditory oddball paradigm. In this sample, P300 potential could be reliably performed by 10/11 FTD patients, notwithstanding their language or executive function deficiencies. The FTD group P300 mean latency was midway between the normal controls and the Alzheimer's disease group (ANOVA F(2, 74199) = 16.5; p = 0.00003). The latency range of the FTD patients were within normal values (average plus 1.96 standard deviation of the values of the control group), except for one case with a latency of 448 ms. Post hoc Newman-Keuls analysis showed that the P300 latencies of the control and FTD groups did not differ significantly (p = 0.15) and that the Alzheimer's disease group had a delayed P300 latency that differed significantly from that of the FTD (p = 0.002) and control group (p = 0.0002). However, there was overlapping in P300 latency values of the three groups. Despite these differences in latencies, the reaction time was significantly increased in the FTD and the Alzheimer's disease groups. These findings indicate that the P300 potential is less affected in patients with FTD than those with Alzheimer's disease. This fact could aid in FTD diagnosis, differential diagnosis with Alzheimer's disease and possibly its clinical management.

Guava fruit (Psidium guajava L.) as a new source of antioxidant dietary fiber.

Guava (Psidium guajava L.) is a tropical fruit, widely consumed fresh and also processed (beverages, syrup, ice cream, and jams). Pulp and peel fractions were tested, and both showed high content of dietary fiber (48.55-49.42%) and extractable polyphenols (2.62-7.79%). The antioxidant activity of polyphenol compounds was studied, using three complementary methods: (i) free radical DPPH* scavenging, (ii) ferric reducing antioxidant power assay (FRAP), and (iii) inhibition of copper-catalyzed in vitro human low-density lipoprotein (LDL) oxidation. All fractions tested showed a remarkable antioxidant capacity, and this activity was correlated with the corresponding total phenolic content. A 1-g (dry matter) portion of peel contained DPPH* activity, FRAP activity, and inhibition of copper-induced in vitro LDL oxidation, equivalent to 43 mg, 116 mg, and 176 mg of Trolox, respectively. These results indicate that guava could be a suitable source of natural antioxidants. Peel and pulp could also be used to obtain antioxidant dietary fiber (AODF), a new item which combines in a single natural product the properties of dietary fiber and antioxidant compounds.

Study of antiphospholipid antibodies in patients treated with antiepileptic drugs.

BACKGROUND: Antiphospholipid antibodies (lupus anticoagulant and anticardiolipin antibodies) are associated with a variety of clinical situations, including drug-intake, but their relationships with antiepileptic drugs have been scarcely investigated. OBJECTIVE: To determine the prevalence of antiphospholipid antibodies in patients treated with antiepileptic drugs and the associated risk of thrombotic events. PATIENTS AND METHODS: We performed the serologic study of thirty-six consecutively prospectively recruited epileptic patients treated with diverse antiepileptic drugs during 44.38 +/- 8.08 months (mean +/- SD) in which antiphospholipid antibodies were determined using cardiolipin and a mixture of phospholipid from rabbit brain as antigen for detection of cardiolipin and lupus anticoagulant by ELISA and in addition lupus anticoagulant was carried out also using coagulometric assays. A clinical evaluation was done in order to determine the presence of thrombotic events in the following five years. RESULTS: Antiphospholipid antibodies were detected in 43% of these patients, in most of them as anticardiolipin antibodies (IgM subtype). The patients did not present thrombotic events during the time of the study. CONCLUSION: Antiphospholipid antibodies are positive in a high proportion of these patients but thrombosis were not found during the study duration. This may be explained by the fact that the profile of aCL positivity not associated to positive LA observed in these patients does not confer a risk for thrombotic events.