Serum levels of S-100B after recreational scuba diving

Recreational scuba diving is a sport of increasing popularity. Previous studies indicating subtle brain injury in asymptomatic divers imply a cumulative effect of minor neural insults in association with diving for professional and/or recreational purposes, over the long-term. This is the first study to investigate putative neural tissue burden during recreational scuba diving by measuring circulating levels of S-100B, a sensitive biomarker of brain injury. 5 male divers performed 3 consecutive dives under conservative recreational diving settings (maximum depth 15 m, duration of dive 56 min, ascend rate 1.15 m/min) with an interval of 12 h between each session. Although a small increase in serum S-100B levels after each dive was apparent, this increase did not quite reach statistical significance (p=0.057). Moreover, no abnormal S-100B values were recorded (mean baseline: 0.06 μg/L, mean post-dive: 0.086 μg/L) and no effect of the 3 consecutive dives on changes in S-100B levels was detected. These results suggest that under the experimental conditions tested, diving does not seem to have a discernible and/or cumulative impact on central nervous system integrity. The extent to which variable diving settings and practices as well as individual susceptibility factors underlie putative neural tissue burden in asymptomatic divers, remains to be established.

The prognostic value of serum S-100B protein in spontaneous subarachnoid haemorrhage

BACKGROUND

Despite the major progress in neurophysiological monitoring, there are still difficulties in the early identification and quantification of cerebral damage after a stroke. In this prospective study we examined the associations between serum S-100B protein, a serum marker of brain injury, and initial neurological-neuroimaging severity, secondary deterioration, external ventricular drainage (EVD: therapeutic intervention) and outcome in patients with subarachnoid haemorrhage (SAH).

METHOD

We recorded all pertinent clinical data of 52 patients with SAH and measured S-100B serum levels on admission and every 24 h for a maximum of 9 consecutive days. Mann-Whitney U-test and Kruskal Wallis analysis were employed to assess the association of S-100B levels with all variables of interest. Log-rank test was used to evaluate survival and Cox's proportional hazard regression analysis to define the significant predictors of survival rate.

FINDINGS

Admission S-100B was statistically significantly associated with initial neurological status, neuroimaging severity, and one-year outcome (p = 0.0002, 0.001, and 0.017, Kruskal Wallis analysis). Admission S-100B above 0.3 microg/L predicted unfavourable outcome (p < 0.0001, log rank test) and constituted an independent predictor of short-term survival (p = 0.035 Cox's proportional hazard regression analysis) with a hazard ratio of 2.2 (95% C.I.: 1.06-4.6) indicating a more than doubling of death probability. Secondary neurological deterioration associated with S-100B increase (p < 0.0001) and external ventricular drainage (EVD) with S-100B reduction (p = 0.003, Wilcoxon signed rank test).

CONCLUSIONS

Serum S-100B protein seems to be a useful biochemical indicator of neurological - neuroimaging severity, secondary deterioration, EVD (therapeutic intervention), and outcome in patients with SAH.

Serum S-100B Protein as A Biochemical Marker of Brain Injury: A Review of Current Concepts

S-100 protein, described initially by Moore, constitutes a large family of at least 20 proteins with calcium binding ability. It is found as homo- or hetero-dimers of two different subunits (A and B). Types S-100AB and S-100BB are described as S-100B protein and are shown to be highly specific for nervous tissue. It is present in the cytosol of glial and Schwann cells, and also in adipocytes and chondrocytes, although in very low concentrations in the latter two. The role of protein S-100B is not yet fully understood. It is suggested that it has intracellular and extracellular neurotropic as well as neurotoxic function. At nanomolar levels, S-100B stimulates neurite outgrowth and enhances survival of neurons. However, at micromolar levels it stimulates the expression of inflammatory cytokines and induces apoptosis. Recently, serum S-100B protein has been proved to be an attractive surrogate marker of primary severe brain injury and secondary insults. It can be measured in the arterial and venous serum; it is not affected by haemolysis and remains stable for several hours without the need for immediate analysis. Its short half-life makes measurements crucial in the emergency and intensive care settings. This review summarises published findings on S-100B regarding its role as a serum biochemical marker of brain injury, i.e., after severe, moderate or mild neuro-trauma, subarachnoid haemorrhage, thrombo-embolic stroke, cerebral ischaemia and brain tumours, as well as extracranial trauma, neurodegenerative and psychiatric disorders.

Alterations in conjunctival cytology and tear film dysfunction in patients with beta-thalassemia

PURPOSE

Patients with beta-thalassemia (beta-tha) represent a group with lifelong transfusion-dependent anemias. This study aimed to describe the conjunctival changes and tear film parameters in these patients.

METHODS

A total of 52 patients (104 eyes) with beta-tha major and 22 normal control subjects (44 eyes) were studied during 1999 through 2000. Tear film break-up time (BUT), Schirmer test, rose Bengal staining, and cytologic evaluation of the conjunctival epithelium were performed in all subjects. The Papanicolaou and May-Grümwald-Giemsa staining procedures were performed on all smears. Patients and control subjects were compared for tear function parameters and conjunctival changes.

RESULTS

The BUT, Schirmer test, and rose Bengal staining values were significantly lower (P < 0.001) in beta-tha patients than in control subjects. Keratinized cells were observed in conjunctival samples in 41% of patients, with a decrease in the number of goblet cells per slide in 64% of patients. In 9% of beta-tha patients, there were a slightly greater number of inflammatory cells than in control eyes.

CONCLUSION

Ocular surface disorder of these patients was characterized by goblet cell loss and conjunctival squamous metaplasia. Our findings were correlated positively with the variable age. Epithelial damage by toxic reaction and disorder of tear quality and quantity are implicated as important factors in the pathogenesis of the ocular surface disease in beta-tha patients.

Protein S-100b serum levels in trauma-induced brain death

OBJECTIVE

To analyze the time course of serum protein S-100b in patients with traumatic brain injury deteriorating to brain death and to investigate the predictive value of initial S-100b levels in relation to clinical and radiologic measures of injury severity with regard to brain death.

METHODS

Forty-seven patients who sustained severe head injury were studied. Blood samples for measurement of S-100b were drawn on admission in the intensive care unit and every 24 hours thereafter for a maximum of 6 consecutive days or until brain death occurred. Variables related to outcome were recorded, including age, sex, Glasgow Coma Scale (GCS), and brain CT findings on admission. Outcome was defined as deterioration to brain death or not.

RESULTS

Of the 47 patients studied, 17 deteriorated to brain death and 30 did not. On admission, patients who became brain dead had higher median serum S-100b levels compared with those who did not (2.32 microg/L vs 1.04 micro g/L, p = 0.0028). Logistic regression analysis showed that initial S-100b was an independent predictor of brain death (p = 0.041), in the presence of advanced age (p = 0.043) and low GCS score (p = 0.013). The odds ratio of 2.09 (95% CI, 1.03 to 4.25) indicates a more than doubling of the probability of deteriorating to brain death per 1- micro g/L increase in S-100b on admission. At clinical brain death, median S-100b was higher in patients with brain death compared with the peak S-100b value obtained over a 6-day period in those who did not become brain dead (6.58 microg/L vs 1.49 microg/L, p < 0.0001).

CONCLUSIONS

Prediction of brain death after severe head injury can be improved by combining clinical and S-100b data; thus, serum S-100b determination deserves to be included in the neuromonitoring of patients with severe traumatic brain injury.

Nuclear grooves in fine needle aspiration (FNA) biopsies of breast lesions

The present study was undertaken to evaluate the significance of grooved nuclei as an additional diagnostic criterion for primary breast carcinoma as well as their association with tumor grade in cytologic material obtained by fine needle aspiration (FNA). Cytologic slides of 105 cases of breast carcinoma (89 ductal, 10 lobular, 3 medullary, 3 mucinous) and 39 cases of benign lesions were reviewed. Histologic confirmation was obtained in all cases. In each case the number of grooved nuclei per 200 well-preserved cells per slide was recorded. Nuclear grooves were found in 62% (65/105) of the malignant and in 36% (14/39) of the benign lesions. This cytomorphologic feature was observed in all histologic types of breast carcinoma. Furthermore, nuclear grooves were present in all grades of ductal carcinoma, and at about the same frequency. Our findings indicate that in the mammary gland nuclear grooving cannot be considered as a criterion of malignancy, and is not helpful either in differentiating the various histologic types or in grading breast tumors in FNA preparations.

Isolation and identification of free amino acids as crystalline N-t-butyloxycarbonyl, O-phenacyl derivatives

A general and efficient method for the quantitative isolation of free amino acids from natural sources and their identification as crystalline N-t-butyloxycarbonyl amino acid phenacyl esters is described. The applicability of this method is illustrated in the isolation and characterization of major free amino acids from the Mediterranean fruit fly Ceratitis capitata.