Modulation of pineal activity during the 23rd sunspot cycle: Melatonin rise during the ascending phase of the cycle is accompanied by an increase of the sympathetic tone.

In two groups of female CD-rats nocturnal urine (19-23 h, 23-3 h, 3-7 h) was collected at monthly intervals over 658 days (I: 1997-1999) and 494 days (II: 1999-2000) coinciding with the ascending limb (1996-2000) of the 23rd sunspot cycle (1996-2008). The excretion of 6-sulfatoxymelatonin (aMT6s: I, II) was determined as well as the ratio of noradrenaline/adrenaline (NA/A: I) reflecting the activity of the sympathetic nervous system. AMT6s was higher in II than I (19-7 h: +24%; P<0.001; 23-3 h: +30% and 3-7 h: +17%, P<0.001), and progressively increased (19-23 h) showing linear regressions (I: R=+0.737, P=0.003; II: R=+0.633, 0.008) which correlated (I) with the Planetary Index (Ap: R=+0.598, P=0.020), an established estimate of geomagnetic disturbances due to solar activity. NA/A rose at all intervals (I: 46-143%) correlating with Ap (R=+0.554-0.768; P=0.0399-0.0013). These results indicate that melatonin secretion rises as solar activity increases during the ascending limb of a sunspot cycle accompanied by growing geomagnetic disturbances (Ap) which elevate the sympathetic tone and thus affect the pineal gland, initially stimulating the activity of arylalkylamine N-acetyltransferase and subsequently fostering the expression of N-acetylserotonin O-methyltransferase (rate-limiting enzyme for melatonin biosynthesis) if Ap increases further. The potential (patho) physiological significance of these findings is discussed and the need for a systematic continuation of such studies is emphasized.

The Association of Subjective Stress, Urinary Catecholamine Concentrations and PC Game Room Use and Musculoskeletal Disorders of the Upper Limbs in Young Male Koreans

The use of PCs can cause health problems, including musculoskeletal disorders (MSDs) of the upper limbs. This study was performed to investigate whether using PCs in PC game rooms may induce MSDs of the upper limbs. 284 young male Koreans were included. A self-administered, structured questionnaire was used to gather information about game room use, perceived subjective stress, and the symptoms related to MSDs. Urinary concentrations of epinephrine, norepinephrine, and dopamine were measured in spot urine. The symptom prevalence of MSDs of the upper limbs increased according to the increase of the duration of game room use. The intensity of perceived subjective stress showed a significant dose-response relationship with the frequency of MSDs symptoms in neck and shoulder areas. However, the urinary level of catecholamines was not significantly correlated with the symptom prevalence of MSDs in the upper limbs. These findings suggest that using PCs in game rooms produce physical stress on the upper limbs, strong enough to induce MSDs.

Separación de aminas biogénicas mediante cromatografía líquida de alta resolución / High-performance liquid chromatographic determination of biogenic amines

En este trabajo se han compilado los distintos modos cromatográficos y sistemas de detección utilizados en la cromatografía líquida de alta resolución de aminas biogénicas. Se indican las características generales del intercambio catiónico, fase reversa, fase reversa de pares iónicos y cromatografía de partición con fase reversa de pares iónicos. También se analizan comparativamente la detección UV, detección fluorimétrica usando fluorescencia nativa o bien derivatización pre- y postcolumna y detección electroquímica de gran utilidad para esta extensa familia de compuestos. Se dan ejemplos de aplicación de interés en el campo bioquímico-clínico, con el análisis de ácido homovainillínico, ácido 3,4-dihidroxifenilacético y ácido 5-hidroxiindolacético en líquido cefalorraquídeo, metanefrinas, ácido 3,4-dihidroxifenilacético, catecolaminas, ácidos urinarios y 3-metoxi-4-hidroxifenilglicol en orina, catecolaminas y 3-metoxi-4-hidroxifenilglicol en plasma, catecolaminas, 3-metoxi-4-hidroxifenilglicol y otros neurotransmisores en cerebro de rata. Se discuten, también, los tratamientos previos requeridos especialmente para orina y plasma, así como las condiciones de conservación y su incidencia en los resultados obtenidos

Estudio humoral en pacientes esquizofrénicos / Humoral determination among schizophrenic patients

Se presentan los resultados del estudio de los niveles de excreción urinaria de Dopamina, Noradrenalina y Adrenalina, así como la concentración y captura plaquetaria de Serotonina en un grupo de pacientes esquizofrénicos y uno de sujetos supuestamente sanos. Se realizaron análisis estadísticos mediante el test de comparación de medias T` (para muestras con dispersiones muy diferentes) y el test U de Mann Withey. Se encontró en los pacientes esquizofrénicos una disminución significativa de la excreción de Dopamina compatible con la acción por años de los neurolépticos sobre los receptores pre y possinápticos, así como un aumento marcado en la Serotonina plaquetaria y en su captura plaquetaria debido entre otros factores a la disminución encontrada en el recambio de Dopamina