Biomedical subjects
M Parslow
Publications and source records attributed to M Parslow.
Developmental changes in pituitary-thyroid function in the human fetus and newborn.
Maturation of the hypothalamic pituitary thyroid axis as reflected in cord serum thyroid hormone concentrations was assessed in premature and full term infants born between 26 and 43 weeks gestation. Measurements of thyroxine (T4), free T4 (FT4), thyrotropin (TSH) and thyroxine binding globulin (TBG) in cord sera were correlated with gestational age, sex and birthweight and compared to similar measurements in well two month old infants and adults. There were significant increases in T4, FT4, and TBG with increasing gestational age (GA) between 26 and 33-35 weeks (P less than 0.001). After 34 weeks, none of these parameters varied with GA. When the infants were separated on the basis of sex the linear regression curves describing the relationships between hormone and TBG concentrations and GA were not different from the curves in the total population. The mean FT4/TSH ratio increased significantly with age throughout gestation (P less than 0.01) and was significantly lower in cord blood samples than in blood samples from the 2-month-old infants or the adults. The results suggest that the set point for negative feedback control of TSH secretion at the pituitary level is changing between 26 weeks GA and 2 months of life. Thyroid gland sensitivity to TSH stimulation also appears to be increasing between 26 and 33 weeks GA.
Interstitial deletion of the long arm of chromosome no. 5 in two unrelated children with congenital anomalies and mental retardation.
Two unrelated children with partial deletion of the long arm of a chromosome no. 5 are reported. The boy presented with severe hypotonia, developmental delay, and a few minor defects of the face including frontal bossing, antimongoloid slant of the palpebral fissures, depressed nasal bridge and bilateral epicanthal folds. With age, his hypotonia has improved. The parents have normal chromosomes; the mother has a 9qh+ variant. The second patient, a girl, presented at birth with multiple congenital anomalies including cleft palate, epicanthal folds, anteverted nostrils, horseshoe kidneys and club feet. At 4 years of age, she was small and severely retarded. The normal parents and the normal sister showed no chromosomal abnormalities. Gene mapping studies in both patients failed to define a specific gene locus to the deleted chromosome regions. Including these two patients, there appear to be only three reported cases of patients with 5q deletion. A comparative description of the third patient is included in this report. There are some clinical similarities but these are inadequate to identify a clinical syndrome. This perhaps is explained by some quantitative and qualitative differences in the deletions.
A deleted extra chromosome 22 identified by DNA replication banding.
The identification of a deleted extra chromosome 22 by means of the DNA replication banding pattern is reported. The characteristics of DNA replication banding, its advantages and superiority in chromosome identification are described.
Two cases of trisomy 12p due to rcpt (12;21)(p11;p11) inherited through three generations.
Two cases of trisomy 12p due to a familial translocation t(12;21) (p11;p11) inherited through three generations are presented. The clinical features of both affected individuals are consistent with those previously reported. Study of the NORs by silver staining showed translocation of the NOR from chromosome 21 onto the der(12) and suggested that the activity of this site has been suppressed in some carriers.