Serum s100b protein levels as a neuroinflammatory biomarker of acutely relapsed paranoid schizophrenia patients.

OBJECTIVE: The s100b inflammatory protein is involved in schizophrenia pathophysiology. We aim at studying the evolution of the s100b serum levels in acutely relapsed paranoid schizophrenia patients at three different time points (admission, discharge and 3 months after hospital discharge 3MAHD). METHODS: Twenty-three paranoid schizophrenia inpatients meeting DSM-IV criteria participated in the research. Twenty-three healthy subjects matched by age, gender and season acted as the control group. Psychopathology was measured with the Positive and Negative Syndrome Scale (PANSS). Serum s100b levels were determined at 12:00 and 24:00 h with an enzyme-linked immunoassay kit. RESULTS: Patients had significant higher serum s100b levels at admission and discharge (12:00 h) than the group of healthy subjects. At admission and discharge, s100b serum levels at 24 h had decreased compared to the 24:00 h s100b levels of the healthy subjects. At 3MAHD patients and healthy subjects had similar levels of serum s100b protein. Positive and negative PANSS scores decreased significantly between admission and discharge. Positive and negative PANSS scores decreased between discharge and 3MAHD, but these changes had no statistical significance. CONCLUSIONS: Our study confirms that the acute inflammatory response produced in acutely relapsed patients is reversed after 3 month of hospital discharge. The variations of serum s100b concentrations when the patients suffer from an acute relapse may be a useful predictor of disease evolution.

Acute paranoid schizophrenia relapsed inpatients present summer/ winter but not day/night changes in serum S100B concentrations.

Healthy subjects present higher summer than winter S100B protein concentrations. There is no available information regarding if schizophrenia patients present the same pattern. The aim of this research is to study if patients with schizophrenia present seasonal changes in serum S100B concentrations.

Day/Night and Summer/Winter Changes in Serum Total Antioxidant Capacity.

BACKGROUND: Seasonal and circadian changes are two factors described to affect blood levels of some biological molecules. The Total Antioxidant Capacity (TAC) is one global measure of the antioxidant capacity of a system. There is no agreement about the existence of day/night changes in TAC levels as well as there is no information about seasonal changes in TAC levels. OBJECTIVE: The aims of this research are studying if there are summer/winter changes in TAC concentrations or if TAC concentrations have day/night changes. METHOD: Ninety-eight healthy subjects took part in the summer study of whom 64 participated in the winter one. Blood was sampled at 09:00, 12:00 and 00:00 h. TAC was measured by the ABTS radical cation technique. Results are expressed in mmol/L of trolox equivalents. RESULTS: The subjects had significantly higher TAC levels in summer than winter at the three-time point studied. Summer 09:00 TAC concentration was significantly higher than the 12:00 and 00:00 h concentrations (1.34±0.26 vs 0.83±0.19, 0.75±0.18). Summer TAC 12:00 h concentrations were significantly higher than the 00:00 h concentrations (0.83±0.19 vs. 0.75±0.18). Winter 09:00 TAC concentrations were significantly higher than the 12:00 and 00:00 h concentrations (1.24±0.16 vs. 0.73±0.10, 0.67±0.13). There were no significant differences between the 12:00 and 00:00 h TAC concentrations. CONCLUSION: Strong methodological biases may be made if the seasonal and circadian changes in serum TAC concentration are not taken into account when researching in this area.

A three-month longitudinal study of changes in day/night serum total antioxidant capacity in paranoid schizophrenia.

Free radicals and an oxidant/antioxidant imbalance have been involved in the schizophrenia pathophysiology. The total antioxidant capacity (TAC) is a measure of the antioxidant capacity of a system. Day/night changes are a biological characteristic of hormones such as melatonin or cortisol. There is little information about TAC day/night changes in schizophrenia patients. The aim of this research is to study if there are day/night changes in serum TAC levels of schizophrenia patients. Thirty-two DSM-IV schizophrenia paranoid patients were studied. Blood was sampled at 12:00 and 00:00 h at admission, discharge and three months after hospital discharge (TMAHD). TAC results are expressed as mmol of Trolox/L. Patients did not have day/night TAC differences at admission (12:00: 0.67±0.12 vs. 00:00: 0.61±0.14, p>0.14) or discharge (12:00: 0.65±0.15 vs. 00:00: 0.65±0.12, p>0.99). At TMHD, patients had significantly higher TAC levels at midday than midnight (12:00: 0.83±0.10 vs. 00:00: 0.74±0.12, p<0.006) as it has been reported in healthy subjects. There were no significant TAC differences at 12.00 and 00:00 between admission and discharge. At TMAHD, patients had significantly higher TAC levels than at admission and discharge, both at 12:00 and 00:00 h. In conclusion, the absence of day/night serum TAC changes when clinically relapsed and the normalization of day/night serum TAC changes at TMHD can be considered as a biological marker of schizophrenia evolution.

Day/night changes in serum S100B protein concentrations in acute paranoid schizophrenia.

There are day/night and seasonal changes in biological markers such as melatonin and cortisol. Controversial changes in serum S100B protein levels have been described in schizophrenia. We aim studying whether serum S100B levels present day/night variations in schizophrenia patients and whether S100B levels are related to psychopathology. Sixty-five paranoid schizophrenic inpatients participated in the study. Psychopathology was assessed with the Positive and Negative Syndrome Scale (PANSS) at admission and discharge. Blood was drawn at 12:00 (midday) and 00:00 (midnight) hours at admission and discharge. Sixty-five healthy subjects matched by age, gender and season acted as control group. At admission and discharge patients had significantly higher serum S100B concentrations at midday and midnight than healthy subjects. At admission, patients showed a day/night variation of S100B levels, with higher S100B levels at 12:00 than at 00:00h (143.7±26.3pg/ml vs. 96.9±16.6pg/ml). This day/night difference was not present in the control group. Midday and midnight S100B at admission decreased when compared to S100B at discharge (midday, 143.7±26.3 vs. 83.0±12, midnight 96.9±16.6 vs. 68.6±14.5). There was a positive correlation between the PANSS positive subscale and S100B concentrations at admission. This correlation was not present at discharge. CONCLUSIONS: acute paranoid schizophrenia inpatients present a day/night change of S100B serum levels at admission that disappears at discharge. The correlation between serum S100B concentrations and the PANSS positive scores at admission as well as the decrease of S100B at discharge may be interpreted as an acute biological response to the clinical state of the patients.

Low levels of serum total antioxidant capacity and presence at admission and absence at discharge of a day/night change as a marker of acute paranoid schizophrenia relapse.

BACKGROUND: An oxidant-antioxidant system dysregulation has been described as a schizophrenia pathophysiological base. The total antioxidant capacity (TAC) is one measure of the antioxidant capacity of a system. Day/night concentration changes is a biological characteristic of hormones such as melatonin or cortisol. There is no information about TAC day/night changes in schizophrenia. AIMS: Studying the existence of a day/night TAC change in schizophrenia. METHOD: Forty-three DSM-IV paranoid schizophrenia inpatients participated in the study. Thirty healthy subjects matched by age and gender acted as control group. Blood was sampled at 12:00 and 00:00h the day after admission and the day before discharge. Serum TAC was measured by the ABTS radical cation technique and expressed in Trolox mmol/L. RESULTS: Patients had significantly lower TAC levels at admission and discharge (12:00 and 00:00) than controls. At admission patients had a TAC day/night change, with higher day-time than night-time levels (0.66±0.14 vs 0.60±0.15) as well as healthy subjects (0.83±0.07 vs 0.77±0.11). At discharge patients had a similar TAC level at 12:00 and 00:00 (0.64±0.15 vs 0.63±0.14). CONCLUSION: Schizophrenic patients present a deficit of the antioxidant system. The initial presence and the later absence of a day/night change deserves future studies.

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.

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.