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Cerebral blood flow was estimated on 60 occasions in 15 well infants, 29-34 wk of gestational age, 5-17 days after birth, using 133-Xenon clearance after intravenous injection. The sleep state of the infants was determined by biparietal electroencephalography, clinical observation, and tracings of heart rate and respiration. Blood flow was 22% higher in the 11 estimations made during wakefulness, when compared to the 17 estimations made during quiet sleep. There was no difference between blood flow in active and quiet sleep. Also there was no difference between blood flow during periods of trace alternant and blood flow during periods of continuous electroencephalographic activity. It is suggested that flow-metabolism coupling is present in stable, preterm infants. The absence of an increase in cerebral blood flow during active sleep as compared with quiet sleep suggests that the neurophysiologic and neurometabolic mechanisms of rapid eye movement sleep are not yet fully developed in preterm infants.

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Nilsson, I., Anderson von Rosen, I . Serum antibodies against Borreliu ufzelii, Borreliu hurgdoyfiri sensu stricto and the 41-kiloDalton flagellin in patients from a Lyme borreliosis endemic area: Analysis by EIA and immunoblot. APMIS 104: 907-914, 1996. To evaluate the possible importance of antigenic heterogeneity in the serological diagnosis of Lyme borreliosis a study was performed using antigens from various Lyme Borreliu strains. Serum samples from 102 patients with clinical signs of the infection, all living in an endemic area in southern Sweden, were evaluated by four enzyme immuno assays (EIA). The sera were initially tested for the immunoglobulin G response to antigens from a local Borreliu ufxlii strain (ACAI). Serum samples from healthy blood donors residing in the same region were used to define seropositivity in the ACAI-EIA. Immunoblotting was performed with the ACAI antigen and the reactive bands were analysed. A serum was defined as positive when at least four of the Borreliu specific polypeptides (OspC, OspA, OspB, p39, p41 [flagellin], p83, p94, I 10kDa) were stained. The same sera were then analysed in three other IgG enzyme immunoassays, one based on antigens from Borreliu burgclorjeri sensu stricto B3 1, and another on pooled protein fractions from strains B31 and ACAI. In the third EIA, sera were analysed for antiflagellin reactivity (B. ufzelii strain DK-1). An inconstant immune response was demonstrated in the EIAs and the seropositivity varied between 30-47'%1 when low positive values were excluded, and between 38-73'%1 if all values were included. Fifty sera (50/102) met the criteria for a positive immunoblot, but positive immunoblots were detected with both low positive and negative sera independent of antigen used in the EIAs. Antigens of the local B. ufzelii strain were found to detect a higher number of seropositive individuals, which suggests that the antibody reactivity to Lyme Borreliu increases when antigens from a strain endemic in a particular geographical region are used. Data from this study suggest that EIA alone seems insufficient for the serodiagnosis, and antigenic heterogeneity of Lyme Borreliu spp. influences the performance of serum antibody tests. The reliability of serological assays could be increased when the serum antibodies against antigens of Borrdiu spp. predominant in the local geographical region are measured. hurgdorferi sensu lato (9). The clinical diagnosis is often difficult, owing to the diffuse and non-