Brain-Derived Neurotrophic Factor (BDNF) and First-Episode Psychosis. A longitudinal one-year prognosis study.

The brain-derived neurotrophic factor (BDNF) is a neurotrophin that has been linked to the schizophrenia neurodevelopmental hypothesis.

DELAYED NEUROPSYCHIATRIC SYNDROME AFTER CARBON MONOXIDE POISONING.

arbon monoxide (CO) is an odorless, tasteless, colorless and nonirritating gas 1. In Spain, most of the accidents due to CO poisoning are caused by water heaters2,3,4. CO binds to hemoglobin with much greater affinity than oxygen, for- ming carboxyhemoglobin (COHb) and resulting in impaired oxygen transport and utilization.XS In up to 40 percent of patients with significant CO exposure, a delayed neuropsy- chiatric syndrome (DNS) can arise 3 to 240 days after appa- rent recovery, characterized by cognitive deficits, personality changes, movement disorders, and focal neurologic deficits, which may persist for a year or longer.

S100B and schizophrenia.

The research for peripheral biological markers of schizophrenia, although abundant, has been unfruitful. In the last 2 decades, the S100B protein has made its own room in this area of research. S100B is a calcium-binding protein that has been proposed as a marker of astrocyte activation and brain dysfunction. Research results on S100B concentrations and schizophrenia clinical diagnosis are very consistent; patients with schizophrenia have higher S100B concentrations than healthy controls. The results regarding schizophrenia subtypes and clinical characteristics are not as conclusive. Age of patients, body mass index, illness duration and age at onset have been found to show no correlation, a positive correlation or a negative correlation with S100B levels. With respect to psychopathology, S100B data are inconclusive. Positive, negative and absence of correlation between S100B concentrations and positive and negative psychopathology have been reported. Methodological biases, such as day/night and seasonal variations, the use of anticoagulants to treat biological samples, the type of analytical technique to measure S100B and the different psychopathological scales to measure schizophrenia symptoms, are some of the factors that should be taken into account when researching into this area in order to reduce the variability of the reported results. The clinical implications of S100B changes in schizophrenia remain to be elucidated.

Chronotype as modulator of morning serum melatonin levels.

BACKGROUND: The search for biological markers of individual characteristics has produced scanty results. Melatonin (MLT), the main hormonal product of the pineal gland, has been used as a biological marker of neuroticism, introversion-extroversion and morningness-eveningness. Morningness-eveningness indicates preferences associated with morning or evening activities. The goal of this research is to study if serum MLT levels are related to morningness-eveningness preference. METHODS: Twenty-three morning type and twenty-one evening type healthy volunteers took part in the study. Morningness-eveningness was evaluated with the Composite Scale of Morningness. Blood was drawn at 09:00, 12:00 and 00:00 h. MLT levels were measured with an ELISA. RESULTS: At 09:00 h evening type subjects had significantly higher serum MLT levels than morning type subjects (8.4±3.6 pg./ml. vs. 4.6±3.2 pg./ml., p<0.02). CONCLUSIONS: Morning serum MLT may be used as a biological peripheral marker of morningness-eveningness preference. Our results emphasise the convenience of expanding MLT studies until 09:00 h when differences between morning type and evening type subjects may still be found.

Factor neurotrófico derivado del cerebro y primeros episodios psicóticos. Estudio pronóstico de un año / Brain-derived neurotrophic factor (bdnf) and first-episode psychosis. a longitudinal one-year prognosis study

Introducción. El factor neurotrófico derivado del cerebro(BDNF) es una neurotrofina que se ha relacionado con la hipótesis del neurodesarrollo de la esquizofrenia. Varios estudios confirman que los niveles de BDNF en el primer episodio psicótico (PEP) son más bajos que en los controles sanos. Sin embargo, los datos al respecto de la evolución de los niveles tras un PEP y el valor pronóstico de dichos niveles son controvertidos. Método. Se compararon los niveles séricos de BDNF al ingreso de 28 pacientes hospitalizados con PEP con 28controles sanos. También se midió el BDNF al momento del alta, a los tres, seis, nueve y doce meses. Los niveles de BDNF se presentan en ng/ml. Se buscó correlación con la sintomatología psicótica medida con la Escala de Síndrome Positivo y Negativo (PANSS) y se evaluó en valor pronóstico de los niveles basales para predecir mala funcionalidad (medida por la Evaluación Global del Funcionamiento) y/o recaída, así como el diagnóstico ulterior de un trastorno psicótico crónico. Resultados. Al ingreso, los niveles de BDNF de los pacientes fueron significativamente más bajos que los niveles de los controles sanos (18,52±4,51 vs. 26,55±3,22, p<0,001). Al altalos niveles de PEP aumentaron hasta niveles de los controles sanos (25,95±3,96 vs. 26,55±3,22, p=0,539). En las siguientes determinaciones, los niveles de BDNF en PEP disminuyeron, alcanzando los valores de ingreso y siendo significativamente más bajos que los controles sanos y los niveles al alta(pacientes: tres meses: 19,68±3,88; seis meses: 19,02±4,13;nueve meses: 17,64±5,24; doce meses:17,51±3,45 vs. controles sanos: 26,55±3,22, todos p<0,001). Se encontró una correlación negativa entre el BDNF al ingreso y las puntuaciones de la subescala de síntomas negativos de la PANSS con una tendencia hacia la significación (r=-0,303, p=0,093). ... (AU)

Introduction. The brain-derived neurotrophic factor(BDNF) is a neurotrophin that has been linked to the schizophrenia neurodevelopmental hypothesis. Several studiesconfirm that the BDNF levels in first-episode psychosis (FEP)are lower than in healthy controls (HC). However, data aboutevolution of BDNF levels after a FEP and about the prognostic value of these levels are controversial. Method. Serum BDNF levels at admission of 28 inpatients with FEP were compared with 28 HC. BDNF was also measured at discharge, three, six, nine and twelve months. BDNF levels are presented in ng/ml. We looked for correlation of BDNF levels with the psychotic symptomatology measuredwith the Positive and Negative Syndrome Scale (PANSS) andalso the prognostic value of basal levels was evaluated topredict poor functionality (measured by the Global Assessment of Functioning) and/or relapse, as well as the subsequent diagnosis of a chronic psychotic disorder. Results. At admission, patients BDNF levels were significantly lower than HC levels (18.52±4.51 vs. 26.55±3.22,p<0.001). At discharge FEP levels increase until HC levels(25.95±3.96 vs. 26.55±3.22, p=0,539). Upon the following determinations, BDNF FEP levels decreased, reaching the admission values, and being significantly lower than the HC andthe levels at discharge (patients: three months: 19.68±3.88;six months: 19.02±4.13; nine months: 17.64±5.24; twelve months: 17.51±3.45 vs. HC: 26.55±3.22, all p<0.001). A negative correlation was found between admission BDNF levels and the PANSS negative symptoms subscale score with a trend towards significance (r=-0.303, p=0.093). BDNF levels at admission of patients with por functionality and/orrelapse at 12 months were lower than BDNF levels of patients with goof functionality and without relapse, this difference had a trend towards significance. (15.38±4.72 vs.19.57±4.06; p=0.071). (AU)

Summer/winter changes in serum S100B protein concentration as a source of research variance.

BACKGROUND: S100B is a calcium binding protein that can be measured in cerebral and extra cerebral biological tissues and fluids. Circadian and seasonal variations have been described in several biological molecules such as melatonin, cortisol and testosterone. Healthy subjects do not have a circadian rhythm of S100B. There is no information on seasonal variations of S100B levels. The aim of this research is to study whether healthy subjects present summer/winter changes in serum S100B protein concentrations. METHODS: Ninety-eight subjects were studied in summer, of those, 64 participated in the winter evaluation. Blood was drawn by venipuncture at 09:00 h, 12:00 h and 00:00 h in summer and winter. Serum was separated from blood by centrifugation and stored at -70° until analysis. Serum S100B concentrations were measured by ELISA. RESULTS: Serum S100B concentrations were significantly higher in summer than winter (09:00 h: 43.4 ± 24.6 ng/ml vs. 29.3 ± 22.7 ng/ml, p < 0.001; 12:00 h: 42.8 ± 25.0 ng/ml vs. 23.0 ± 22.1 ng/ml, p < 0.001; 00:00 h: 44.5 ± 23.2 ng/ml vs. 28.5 ± 24.6 ng/ml, p < 0.001). Age, gender, body mass index and time points when blood was extracted did not affect serum S100B concentrations neither in summer nor in winter. CONCLUSIONS: Our results point to the fact that there is an important difference in serum S100B concentrations between summer and winter. It is strongly advisable to consider this summer/winter difference in serum S100B concentrations when researching into this area.

El cronotipo como modulador de los niveles séricos diurnos de melatonina / Chronotype as modulator of morning serum melatonin levels

Introducción. La búsqueda de marcadores biológicos que se relacionen con características específicas de las personas no ha producido grandes resultados. Los niveles sanguíneos de la melatonina (MLT), principal producto hormonal de la glándula pineal, han sido utilizados como marcador biológico del neuroticismo, la introversión-extroversión y la matutinidad vespertinidad. El concepto de matutinidad hace referencia a la preferencia de las personas para realizar actividades por las mañanas, mientras que la vespertinidad hace referencia a la preferencia para realizar actividades por la noche. El objetivo de este trabajo consiste en estudiar si los niveles séricos de MLT se relacionan con la matutinidad o vespertinidad. Metodología. La muestra está compuesta por 44 voluntarios sanos, de los cuales 23 son del tipo matutino y 21 del tipo vespertino. La matutinidad-vespertinidad fue valorada con la Escala Compuesta de Matutinidad. Se analizaron 3 muestras de sangre, extraídas a las 09:00, 12:00 y 00:00 h. Los niveles de MLT fueron determinados mediante un ELISA. Resultados. A las 09:00 h, los sujetos vespertinos tenían niveles de MLT significativamente más altos que los sujetos matutinos (8,4±3,6 pg/ml vs 4,6±3,2 pg/ml, p<0,02).Conclusiones. Los niveles séricos de MLT a las 09:00 h. pueden ser usados como un marcador biológico periférico de vespertinidad-matutinidad. Nuestros resultados enfatizan la conveniencia de alargar los estudios de MLT al menos hasta las09:00 h, cuando aun se pueden encontrar diferencias en los niveles séricos de MLT entre los tipos matutinos y vespertinos (AU)

Background. The search for biological markers of individual characteristics has produced scanty results. Melatonin (MLT), the main hormonal product of the pinealgl and, has been used as a biological marker of neuroticism, introversion-extroversion and morningness-eveningness. Morningness-eveningness indicates preferences associated with morning or evening activities. The goal of this research is to study if serum MLT levels are related to morningness eveningness preference. Methods. Twenty-three morning type and twenty-one evening type healthy volunteers took part in the study. Morningness-eveningness was evaluated with the Composite Scale of Morningness. Blood was drawn at 09:00, 12:00 and 00:00 h. MLT levels were measured with an ELISA. Results. At 09:00 h evening type subjects had significantly higher serum MLT levels than morning type subjects (8.4±3.6 pg./ml. vs. 4.6±3.2 pg./ml., p<0.02). Conclusions. Morning serum MLT may be used as a biological peripheral marker of morningness-eveningness preference. Our results emphasise the convenience of expanding MLT studies until 09:00 h when differences between morning type and evening type subjects may still be found (AU)