Erythropoietin attenuates lipopolysaccharide-induced splenic and thymic apoptosis in rats.

Apoptosis of lymphoid tissues during sepsis is well documented and linked to the pathobiology of organ failure and death. In this study, we evaluated the effect of a single dose of recombinant erythropoietin (EPO) on thymic and splenic apoptosis in an endotoxic sepsis model. Young male Wistar rats were divided into 3 groups and administered intraperitoneally (IP) either normal saline; lipopolysaccharide (LPS) 10 mg/kg; or EPO (5000 U/kg) 30 min before lipopolysaccharide. Six hours following LPS administration animals were sacrificed. Apoptosis was assessed by hematoxylin-eosin staining, terminal deoxynucleotide transferase-mediated fluorescein-dUTP nick end labeling (TUNEL), and caspase-3 immunostaining. When compared with animals given LPS, animals pretreated with EPO displayed reduced splenic and thymic TUNEL positivity of 44+/-3 (p<0.05) and 143+/-4 (p<0.05) nuclei per high power field (hpf), respectively. Caspase-3 positivity was also significantly reduced in the spleen and thymus, with 31+/-4 (p<0.05) and 93+/-3 (p<0.05) positive stained nuclei per hpf, respectively. Serum nitrite levels were elevated in animals given lipopolysaccharide. Pretreatment with EPO attenuated the increase in nitrite levels; however, this did not reach statistical significance. We conclude that a single dose of recombinant erythropoietin can reduce thymic and splenic apoptosis associated with lipopolysaccharide administration.

Transcranial Doppler assessment of cerebral blood flow velocity in term newborns.

Using the transcranial Doppler technique to assess postnatal changes in cerebral blood flow velocity, we studied the anterior cerebral artery, middle cerebral artery, and internal carotid artery of 31 healthy, term newborn infants. Normative values for the 1st, 3rd, and 5th days of life were determined. Cerebral blood flow velocity values in all three arteries examined correlated well with each other and we observed a statistically significant increase only in middle cerebral artery blood flow velocity between the 1st and 3rd, and 1st and 5th postnatal days. Thus, if we assume that flow velocities in various cerebral arteries undergo similar change, only one representative artery need be examined. The middle cerebral artery appears to be the vessel of choice. This choice simplifies the recording procedure, particularly in repeated examinations.