Hematoma volume affects the accuracy of computed tomographic angiography 'spot sign' in predicting hematoma expansion after acute intracerebral hemorrhage.

BACKGROUND: We hypothesized that the presence of tiny, enhancing foci ('spot sign') within acute hematomas is associated with hematoma expansion. METHODS: We retrospectively analyzed the effect of hematoma volume on accuracy of computed tomographic angiography (CTA) in predicting hematoma expansion in 312 patients with acute intracerebral hemorrhage (ICH). The patients were divided into 2 groups according to their initial hematoma volume (<30 vs. ≥30 ml). CTA was performed at admission and 24 h after initial presentation. RESULTS: The <30-ml group consisted of 203 patients of whom 42 had hematoma expansion (20.9%). The ≥30-ml group consisted of 109 patients of whom 34 had hematoma expansion (31.19%). In the <30-ml group, the sensitivity and specificity of CTA in predicting hematoma expansion were 71.4 and 93.8%, respectively. In the ≥30-ml group, the sensitivity and specificity of CTA were 85.7 and 91.9%, respectively. For all 312 patients, the area under the curve was 0.86 (p < 0.001, 95% CI 0.80-0.92); the sensitivity and specificity of CTA were 77.9 and 93.2%, respectively. CONCLUSIONS: CTA can reliably predict hematoma expansion in clinical practice, especially for hematomas >30 ml.

[Time course of calpain activity changes in rat neurons following fluid percussion injury and the interventional effect of mild hypothermia].

OBJECTIVE: To investigate the time course of calpain activity changes in rat neurons following fluid percussion injury (FPI) under normothermia (37 degrees celsius;) and mild hypothermia (32-/+0.5) degrees celsius;. METHODS: In vitro cultured rat neurons were subjected to FPI followed by application of mild hypothermia for intervention at different time points, and the changes in intraneuronal calpain activity following FPI and the interventional effect of mild hypothermia on calpain activity were evaluated by UV-spectrophotometry at different time points. RESULTS: Remarkable changes occurred in calpain activity in the neurons following FPI at 37 degrees celsius;, and mild hypothermia produced obvious interventional effect on calpain activity in close relation to the timing of intervention initiation. CONCLUSION: Intraneuronal calpain activity changes following FPI are involved in the pathological process of cellular injury, and mild hypothermia might offer protection against traumatic brain injury to some extent by regulating calpain activity. The interventional effect of mild hypothermia is associated with the timing of the intervention initiation.

[Labeling neural stem cells with superparamagnetic iron oxide in vitro and tracking after implantation with MRI in vivo].

OBJECTIVE: To evaluate the feasibility of monitoring the neural stem cells implanted into the brain by the technique of labeling with superparamagnetic iron oxide (SPIO). METHODS: Neural stem cells were isolated from the cerebral cortex of newborn Wister rats and cultured. SPIO particles and poly-L-lysine were added into the medium to be co-cultured foe one hour. After the formation of neurospheres, Prussian blue staining was conducted and transmission electron microscopy was used to identify the iron particles in these neural stem cells. Sixteen adult female Wistar rats underwent transplantation of labeled neural stem cells into the right side of brain and non-labeled cells were transplanted into the contralateral part as controls. 1, 2, 4, 6, and 7 weeks after the transplantation, MRI examination with the scanning sequences of SE T2WI, FSE T2WI, and GRE T2 * respectively was conducted on the brains of the rats. Four rats at each time point were killed and their brains were taken out to undergo HE staining and Prussian blue staining to track the presence of labeled-cells. RESULTS: After the addition of SPIO the neurospheres continued to proliferate and differentiate normally. Electron microscopy showed vacuolar structures of different sizes under the cytoplasma membrane within and outside which there were high-density iron particles. Prussian blue staining showed numerous blue stained particles in the cytoplasm of the labeled cells. Remarkable low signal change was seen in the right brain transplanted with labeled cells, especially in the condition of scanning sequence of GRET2. Such change could be seen up to 7 weeks after the transplantation. No signal change was found in the left brain. CONCLUSION: SPIO labeling technique is useful in monitoring the outcome of transplanted neural stem cells.