***TASK*** the task is to summarize an input biomedical literature in six sentences 
    ***INPUT*** the input is a biomedical literature 
    ***OUTPUT*** the output is the summary of an input biomedical literature in six sentences 
    ***DOCUMENTATION*** 
    ***EXAMPLES*** 
    Input: S100B is a protein which exerts both detrimental and neurotrophic effects , depending on its concentration in brain tissue . An increase of S100B in micromolar concentrations is observed in traumatic brain conditions and is associated with poor outcome . Micromolar levels of extracellular S100B in vitro may have deleterious effects . However , in nanomolar concentrations S100B has multiple neurotrophic effects in vitro may in vivo be regarded as a hallmark of neuroprotective efforts . This pilot study addresses the hypothesis that S100B serum concentrations may be of predictive validity for the response to antidepressant treatment in patients with major depression .  S100B plasma levels were determined in 25 patients with major depression and 25 matched healthy controls using an immunofluorimetric s and wich assay . S100B plasma levels were significantly higher in major depressive patients than in healthy controls and positively correlated with treatment response after 4 weeks of treatment . In a linear regression model , a significant predictive effect was found only for S100B and severity of depressive symptoms upon admission . These results suggest that neuroprotective functions of S100B counterbalance neurodegenerative mechanisms that are involved in the pathophysiology of major depression and in the response to antidepressant treatment Background Acute management of traumatic brain injury ( TBI ) , in particular mild TBI , focuses on the detection of the 5–7 % who may be harboring potentially life-threatening intracranial hemorrhage ( IH ) using CT scanning . Guidelines intending to reduce unnecessary head CT scans using available clinical variables to detect those at high IH risk have shown varying results . Recently , the Sc and inavian Neurotrauma Committee ( SNC ) derived a new set of high-IH risk variables for adults with TBI using an evidence -based literature review . Unlike previous guidelines , the SNC guideline incorporates serum values of the brain protein S100B with clinical variables . Methods We performed a nested cohort study of adults with mild TBI presenting to six emergency departments in New York and Pennsylvania within 6 h of injury . Patients were managed according to existing guidelines for CT selection . All patients underwent head CT scanning and serum S100B measurement , as well as prospect i ve collection of clinical variables , as a requirement of the parent study . Using the SNC guidelines , S100B values and clinical variables were applied to these subjects , classifying each into one of five pre-defined severity categories , as well as predicting the need for head CT scanning to identify IH . This classification was then compared to actual head CT results to determine guideline sensitivity and specificity . Results In total , 662 adults ( mean age 42 years , range 18–96 ; 258 females , 549 Caucasians ) were available for analysis ; 36 ( 5 % ) had IH on head CT scan . The SNC guidelines had a sensitivity of 97 % ( 95 % CI , 84–100 % ) and a specificity of 34 % ( 95 % CI , 30–37 % ) for the detection of IH on head CT . Application of the SNC guidelines would have result ed in a CT reduction of 32 % ( 211/662 patients ) . One patient with low-risk mild TBI and a S100B level under 0.10 μg/L had a traumatic CT abnormality and would have been discharged with strict adherence to the guidelines . However , this patient did not need any intervention for the injury and had a good outcome . Conclusion Using the SNC guideline could save approximately one third of CT scans in a pre-selected cohort of mild TBI patients with little or no impact on patient outcome Rationale S100B is an astrocytic , calcium-binding protein which in nanomolar concentrations has neuroprotective and regenerating effects on neurons and glial cells . Increased levels have been shown to be positively correlated with therapeutic response in major depression . Event-related potentials ( ERP ) have been reported to be impaired in depressed patients . Objectives The aim of our study was to assess the relationship between S100B and visually evoked ERP in depression . Methods ERP and S100B serum concentration were studied in 18 patients with major depression , before and after 4 weeks of antidepressant treatment .  Results The S100B concentration in patients was increased at intake and after 4 weeks of treatment compared to healthy controls . Initially increased P3-latency normalized and P2-latency significantly decreased after 4 weeks of treatment , although only in patients with clearly elevated initial S100B levels ( mean plus 2 SD of the healthy controls ) . Conclusion The neuroregenerative activity of moderately increased S100B levels in major depression might be a factor contributing to a decrease of prolonged ERP parameters in major depression during antidepressant treatment Disturbances in the serotonergic system are considered to be implicated in the pathophysiology of depressive disorders . The possible role of the neurotrophic factor S100 beta , which is suspected to regulate regeneration of serotonergic synapses , has not been investigated in depressive disorders . The  S100 beta concentration in the cerebrospinal fluid was measured in 11 patients with the current diagnosis of mild or moderate depressive episodes ( DSM-IV ) and in 11 matched control patients . Using the t test for paired sample s , the presence of a depressive episode was significantly associated with an elevation of the cerebrospinal fluid concentration of S100 beta ( t = 2.6 , d.f . = 10 , p = 0.024 ) . Replications of this finding in severely depressed patients are necessary to confirm the association between neurotrophic factor S100 beta and depressive disorders 
    Output:
    
The results indicated that elevated S100B levels might be associated with mood episodes in affective disorders .