This study was carried with the intention of explaining the causes of modifications in intracranial pressure (ICP) during paradoxical sleep (PS) in normal and hydrocephalic infants, and establishing relationships between these modifications and cerebral blood volume (CBV). All tests (conventional sleep polygraphy, ICP measured by a transducer on the fontanel, CBV measured by isotopic labelling of red blood cells in vivo) were carried out without use of surgical procedures. During paradoxical sleep there was a sustained wave of increased intracranial pressure lasting from 10 to 20 minutes, as well as phase-type variations lasting no longer than 1 minute. Increased ICP was also observed in the normal subjects. Recordings show that there is well-defined correlation between the sustained wave of high intracranial pressure and an increase in CBV.

Blood Volume↗

PubMedDate not supplied

[Respiration and night sleep in children "at risk" for sudden and unexpected death (author's transl)].

Polygraphic recordings were used to study respiration and night sleep in 26 such children. These children, who were "at risk" for sudden and unexpected death, could be divided into two groups : near-miss (NM) (15 cases), and those who were brothers, sisters, or cousins of a child who had died suddenly and unexpectedly (8 cases), or had periodic respiration (RP) (3 cases). No significant differences were found between the groups in respiratory tests, except for a significantly lower RP rate in the NM group and an increase in number of isolated pauses. Sleep organization was similar in both groups, though there was a significantly higher rate of active sleep (SA) in the NM group more than 2 months old. The highest respiratory indices were noted in the extreme cases of a non-NM group (including 2 brothers of infants who had died unexpectedly). Treatment with Diphemanil methylsulfate (Prantal) reduced the number of SA and respiratory pauses of the NM infants less than 2 months old.

Female↗

PubMedDate not supplied

Retinoic acid modulates RAR alpha and RAR beta receptors in human glioma cell lines.

To identify retinoic acid (RA) signalling pathways involved in growth and differentiation in cells of the glial lineage, two human glioma ceh lines were studied. The three RA receptors (RARs) mRNAs were constitutively expressed, and of the three RXRs, RXR beta appeared predominant. Western blotting analysis confirmed the constitutive expression of RAR alpha and RAR beta. Treatment with all-trans-RA induced morphological changes in the two cell lines, which progressed from their normal pattern of randomly oriented spindle-shaped cells to fibroblast-like glial cells. RA up-regulated RAR alpha and RAR beta mRNAs in both cell lines. Interestingly, RA treatment up-regulated RAR beta proteins but not RAR alpha proteins, suggesting post-transcriptional regulations of RAR transcripts in glioma cells.

Brain Neoplasms↗

PubMedDate not supplied

Night sleep heart rate patterns recorded by cardiopneumography at home in normal and at-risk for SIDS infants.

It has been reported that infants at higher than normal epidemiological risk for the sudden infant death syndrome (SIDS) have abnormal cardiac autonomic activity. A prospective work was performed using cardiopneumographic recordings (CPG) in order to evaluate heart rate (HR) and heart rate variability (HRV) patterns in sleeping normal control infants (C) and in infants at-risk for SIDS in their normal environment at home. One hundred appropriate-for-gestational age full-term infants were studied: 28 C, 48 SIDS siblings (SS), and 24 near-miss for SIDS (NM) within the first 2 weeks following the first detected apparent life-threatening event. The three groups of infants were comparable with respect to gestational and conceptional ages, birthweights, sex distribution and socio-economic backgrounds. CPG were done over two successive nights. Records were visually analysed for sleep states (quiet: QS, and combined active + indeterminate sleep: AIS) and wakefulness (W) coding. Periods of W were not analysed. An automatic programme allowed us to study HR minute-by-minute, and to assess whether HR and HRV patterns were specific to a certain part of the night, records were divided into three periods (2200-0040 h, 0041-0320 h, and 0321-0600 h). In C and SS groups, the HR was significantly lower in the 2nd night-period than in the 1st and 3rd periods in both QS and AIS (P less than 0.05). In the NM group this difference was only observed during AIS (P less than 0.05). During the three night-periods the HR was significantly elevated in AIS as compared to QS (at least P less than 0.05) in all infant groups except the NM group during the 2nd night-period. During QS the HR was significantly higher in NM than in C and SS groups (P less than 0.02). During AIS the HR did not differ between infant groups. HRV was significantly lower in the NM group during QS in the three night-periods (P less than 0.05). There was no difference in the HR and HRV patterns between C and SS groups with respect to sleep states and night period. We concluded that following the first detected apparent life-threatening event differences in the HR and HRV patterns can be demonstrated when sleeping NM infants are compared with both C and SS infants especially during QS in different night periods studied by CPG at home.

Female↗

PubMedDate not supplied

[Sleep disorders in children].

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Child↗

PubMedDate not supplied

[Sleep rhythms in children].

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Child↗