Saliva S100B in professional sportsmen: High levels at resting conditions and increased after vigorous physical activity.

BACKGROUND: Neurological dysfunction is a key medical concern in professional sportsmen (PSM). We investigated whether saliva S100B concentrations in PSM and healthy controls are modified before and after training. METHODS: We conducted a case-control-study in 75 patients (25 PSM vs 50 controls) in which S100B saliva concentrations were expressed as absolute values and percentage of change (%) from samples drawn before (T0) and after (T1) training. RESULTS: No differences (P>0.05) between groups were found regarding clinical, monitoring and laboratory parameters. S100B both in PSM and controls was higher at T1 when compared to T0 (P<0.01). In PSM, S100B was higher than controls (P<0.001) at T0 and T1. S100B% at T0-T1 was higher (P<0.001) in PSM and in controls and between PSM and controls (P<0.001). CONCLUSIONS: Increased saliva S100B levels in PSM before and after training suggest a paracrine/autocrine protein's role connected to stressing activity, which becomes especially evident in PSMs.

Urinary S100A1B and S100BB to predict hypoxic ischemic encephalopathy at term.

Urinary S100A1B and S100BB were measured to detect cases at risk of hypoxic-ischemic encephalopathy (HIE) in asphyxiated newborns. We recruited 42 asphyxiated infants and 63 healthy term neonates. S100A1B and S100BB were measured at first urination (time 0) and at 4 (time 1), 8 (time 2), 12 (time 3), 16 (time 4), 20 (time 5), 24 (time 6), 72 (time 7) hours after birth. 20 infants had no/mild HIE with good prognosis (Group A) and 22 had moderate/severe HIE with a greater risk of neurological handicap (Group B). Urine S100A1B and S100BB levels were significantly (P less than 0.0.01, for all) higher at all monitoring time-points in Group B than Group A and controls, but not between Group A and controls. Both S100A1B and S100BB have great sensitivity and specificity for HIE since their first measurement. In conclusion, S100A1B and S100BB are increased in urine collected from asphyxiated newborns who will develop HIE since first urination, and their measurement may be useful to early predict HIE when monitoring procedures are still of no avail.

High maternal blood S100B concentrations in pregnancies complicated by intrauterine growth restriction and intraventricular hemorrhage.

BACKGROUND: Intrauterine growth restriction (IUGR) is associated with perinatal mortality and with neurologic damage from intraventricular hemorrhage (IVH). We investigated whether S100B, a neural protein found in high concentrations after cell injury in the nervous system, is increased in serum of women whose pregnancies are complicated by IUGR and whose newborns develop IVH. We also explored the prognostic accuracy of maternal serum S100B for IVH in the newborn. METHODS: We conducted a case-control study of 106 pregnancies complicated by IUGR, including a subgroup (n = 26) who developed IVH after birth, and 212 unaffected pregnancies matched for gestational age. Ultrasound examination, Doppler velocimetry patterns (in the utero-placental vessels and middle cerebral artery), and maternal blood collection were performed before birth; cerebral ultrasound and neurologic examinations were performed after birth. RESULTS: S100B was higher (P <0.001) in IUGR pregnancies complicated by IVH than in those that were not and in controls. At a cutoff of 0.72 microg/L, sensitivity was 100% [95% confidence interval (95% CI), 87%-100%] and specificity was 99.3% (97.5%-99.9%) for prediction of IVH (area under the ROC curve, 0.999). The prevalence of IVH was 8.2% in the whole study population, 93% (95% CI, 83.6%-100%) in those with maternal S100B >0.72 microg/L, and 0% (0%-2.5%) in those with maternal S100B <0.72 microg/L. CONCLUSION: For prediction of IVH, measurements of maternal S100B may be useful at times before clinical, laboratory, and ultrasound patterns can identify risk of IVH.

A single course of antenatal betamethasone reduces neurotrophic factor S100B concentration in the hippocampus and serum in the neonatal rat.

The effects of a single course of antenatal betamethasone on S100B protein concentration were investigated in Fisher 344 rats. On day 20 of gestation, pregnant rats were injected twice 8 h apart with either (1) 170 microg kg(-1) body weight betamethasone ("clinically-equivalent dose", equivalent to 12 mg twice, 24 h apart in humans), (2) half of this dose (equivalent to 6 mg) or (3) vehicle. We report reference values for S100B protein in the serum and different brain regions in both genders at 1, 2, and 21 days after birth. Interestingly, S100B concentration showed a time-dependent and brain region-specific pattern of expression. At P1, S100B was higher in the serum of males compared to females. In addition, we show that both doses of betamethasone decreased S100B concentration in the serum of males at P1, whereas in the hippocampus, it was reduced by the clinically-equivalent dose only. This suggests that lowering the dose of antenatal betamethasone may be less detrimental for brain maturation and therefore we reiterate the need for clinical trials with a low dose regimen.

Amniotic fluid S100B protein in mid-gestation and intrauterine fetal death.

Fetal death in the mid-trimester of pregnancy is unexplained and no reliable markers are available to identify at-risk women. We aimed to assess use of alpha fetoprotein and S100B concentrations in amniotic fluid as markers. We did a case-control study in 758 healthy women undergoing amniocentesis at mid-gestation, of whom 12 had a spontaneous intrauterine fetal death before 28 weeks, and 746 matched controls. Concentrations were corrected for gestational age by conversion to multiples of median (MoM) of healthy controls of the same gestational age. Concentrations of S100B, but not alpha fetoprotein, were significantly higher (p<0.0001) in women who later had spontaneous fetal death (median 4.431 MoM [95%CI 3.605-6.197]) than in controls (1.000 MoM [1.062-1.121]). Sensitivity, specificity, and positive and negative predictive values of S100B as a diagnostic test were 100%, suggesting that measurement of this protein at amniocentesis could be useful to identify at-risk women.

Amniotic fluid levels of S100B protein in normal and trisomy-21 foetuses.

BACKGROUND: The human chromosome 21 has been shown to contain the gene for the beta subunit of the S100B protein. The present case-control study was aimed at investigating whether overproduction of S100B protein is detectable in the amniotic fluid of foetuses with trisomy-21. METHODS: Measurements of S100B in amniotic fluid samples from 14 pregnant women with trisomy-21 foetuses were compared with those obtained from 182 physiological pregnancies. S100B was measured in the samples using an immunoluminometric assay (LIA-mat Sangtec 100). RESULTS: Our results showed that S100B protein amniotic fluid levels were significantly higher in trisomy-21 foetuses (0.83+/-0.21 microg/l) than in controls (0.51+/-0.22 microg/l) (p<0.05). CONCLUSION: The present finding supports the notion that the expression of S100B is increased in trisomy-21 foetuses; it also constitutes a prerequisite basis for a possible involvement of the protein in pathogenic processes associated with trisomy-21, and/or for its potential employment as a diagnostic tool.

Human milk contains S100B protein.

The present study constitutes the first finding of the calcium-binding protein S100B and of its mRNA in human milk, as revealed by a quantitative immunoluminometric assay, by Western blot analysis and by reverse transcription-polymerase chain reaction (RT-PCR) assay followed by restriction enzyme digestion. The concentration of S100B in milk is markedly higher than that observed in other biological fluids such as cord blood, peripheral blood, urine, cerebrospinal fluid and amniotic fluid. This finding could be related to a possible trophic role, which has been hypothesized for the protein.