Search PubMed⌕ Search

Biomedical subjects

S Fraser

Publications and source records attributed to S Fraser.

111 records · Page 7Linked to original sources
PubMedDate not supplied

Clinical significance of isolated paraventricular cysts on cranial ultrasonography.

OBJECTIVES: Isolated paraventricular cysts detected on routine cranial ultrasonography in premature and full term neonates are often incidental findings. The aetiology and clinical significance of these lesions is uncertain. A case control study was designed to attempt to clarify the clinical significance of isolated paraventricular cysts in terms of growth and neurodevelopment. METHODS: Ten infants with isolated paraventricular cysts on neonatal cranial ultrasonography were identified. These were matched with 10 control infants for sex, gestational age and birthweight. All infants were assessed at a corrected age of 18-31 months for growth and neurodevelopment. Two index infants and their controls were excluded from analysis of psychometric data as the neurodevelopmental assessment tools used were different. RESULTS: There was no statistically significant difference between the index and control groups in terms of growth, motor and psychometric assessment at follow up. CONCLUSIONS: The study suggests that isolated paraventricular cysts detected on routine cranial ultrasonography have no prognostic significance. However the study involved a small sample size with limited power of study (power = 0.3). A larger prospective cohort study would help to clarify the clinical significance of this condition.

Case-Control Studies↗
PubMedDate not supplied

Analysis of neural crest cell lineage and migration.

In this review, we describe the results of recent experiments designed to investigate various aspects of neural crest cell lineage and migration. We have analyzed the lineage of individual premigratory neural crest cells by injecting a fluorescent lineage tracer dye, lysinated fluorescein dextran, into cells within the dorsal neural tube. Individual clones contained cells that were located in very diverse sites consistent with their being sensory neurons, prepigment cells, Schwann cells, adrenergic cells, and neural tube cells. These results suggest that some neural crest cells in the trunk and cranial regions are multipotent prior to their emigration from the neural tube. The environment through which neural crest cells move influences both the pattern and direction of their migration. We have shown that the sclerotomal portion of the somites are responsible for the rostrocaudal pattern of trunk neural crest cell movement, whereas the neural tube appears to govern the dorsoventral position of neural crest-derived ganglia. In addition, the notochord inhibits the movement of neural crest cells. In order to understand necessary cell-matrix interactions in neural crest migration, we have performed perturbation experiments, in which antibodies directed against cell surface or extracellular matrix molecules were introduced along neural crest pathways. We find that integrins, fibronectin, laminin, and tenascin all play some role in cranial neural crest emigration. Thus, multiple factors may be involved in controlling neural crest cell migration, and different factors may be important for migration in different regions of the embryo.

Animals↗