YKL-40 expression in traumatic brain injury: an initial analysis

YKL-40 (chitinase 3-like protein 1) is expressed in a broad spectrum of inflammatory conditions and cancers. We have previously reported that YKL-40 levels are elevated in the cerebrospinal fluid (CSF) of macaques and humans with lentiviral encephalitis, as well as multiple sclerosis (MS). The current study assessed temporal CSF YKL-40 levels in subjects with severe traumatic brain injury (TBI; Glasgow Coma Scale [GCS] score <or=8). We also evaluated temporal expression of YKL-40 after parasagittal controlled cortical impact (CCI) injury over the parietal cortex (2.8 mm deep, 4 m/sec). We demonstrate that CSF YKL-40 levels are elevated after acute TBI, and that YKL-40 levels are higher in patients who died following injury than in patients who survived. YKL-40 levels significantly correlate with CSF levels of inflammatory cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha), as well as the inflammatory marker C-reactive protein (CRP). After CCI, in situ hybridization (ISH) showed that YKL-40 transcription is primarily associated with reactive astrocytes in pericontusional cortex. Tissue YKL-40 transcription time course analysis after CCI showed that YKL40 transcription in astrocytes began 1 day after injury, remained elevated for several days, and then declined by day 12. Similarly to our temporal CSF measurements in humans, YKL-40 induction after CCI is coincident with IL-1beta expression. Taken together these findings demonstrate that YKL-40 is induced in astrocytes during acute neuroinflammation, is temporally related to inflammatory mediator expression, and may be a useful biomarker for understanding secondary injury and for patient prognosis.

Extracorporeal treatment with cyanate in sickle cell disease: preliminary observations in four patients

The effects of extracorporeal carbamylation were determined in four patients with sickle cell anemia. Treatments were carried out in clusters every 4 to 6 weeks over a 6-month period. Mean carbamylation achieved in vivo was 1.3 moles cyanate per mole of hemoglobin. The mean in vitro P50 during treatment was 22.1 mm. Hg as compared to the pretreatment value of 30 mm. Hg. Hemoglobin concentration was increased over the 6 months by 24 per cent. The treatment resulted in the stimulation of erythropoiesis. Treated cells had a prolonged survival of about 40 days, but bilirubin did not fall. Blood volume and heart size remained unchanged. Carbamylation did not appear to alter the degree of sickling at any given O2 saturation. Painful attacks continued through the treatment period with a frequency of 84 per cent and a severity-frequency index of 77 per cent of that in the control period. There was no evidence of cyanate toxicity associated with extracorporeal therapy.