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Biomedical subjects

E F Robertson

Publications and source records attributed to E F Robertson.

At least 55 records · Page 3Linked to original sources
PubMed1986

Management and outcome of children with congenital hypothyroidism detected on neonatal screening in South Australia.

Thirty-eight congenitally hypothyroid children who were detected in a neonatal screening programme have been treated for a mean period of 3.8 years (range, 0.5-8.5 years) by the maintenance of the free thyroxine index in the upper normal range as the main determinant of the dose of thyroxine. Only excessive elevation of, or serial rises in, thyroid stimulating hormone (TSH) level influenced the dose of thyroxine. This treatment strategy, which aims to avoid the potentially adverse effects of thyroxine overdosage, has often resulted in delayed return of TSH levels to normal, especially in athyrotic children (mean TSH +/- SD at one year of age in athyrotic children, 72 +/- 90 mU/L; in children with ectopic thyroid glands, 24 +/- 16 mU/L; normal range, 0-7 mU/L). The mean thyroxine dose of about 100 micrograms/m2 did not change significantly with age, and is lower than the doses that are sometimes quoted in the literature; athyrotic children require significantly more thyroxine (P less than 0.05) than those with ectopic thyroid glands. Symptoms and signs of congenital hypothyroidism, although subtle, were significantly more common (P less than 0.05 for symptoms and P less than 0.001 for signs) in athyrotic children compared with those with ectopic glands. No physical or developmental abnormality related to congenital hypothyroidism has been demonstrated on follow-up; mean height and weight percentiles approximate the 50th percentile at ages one to six years and mean developmental scores +/- SD at about two years of age by the Griffiths Mental Development Scale and at 4.5-6.5 years by the Wechsler Preschool and Primary Scale are 102.4 +/- 10.4 and 111.2 +/- 12.2, respectively. Long-term follow-up studies are necessary to exclude more subtle developmental and neurological abnormalities.

Age Determination by Skeleton↗
PubMed1986

The Port Pirie cohort study: maternal blood lead and pregnancy outcome.

During a three-year period, 831 pregnant women in and around Port Pirie, South Australia--a lead smelter community with longstanding lead pollution--were enrolled in a cohort study to examine prospectively the relation between body lead burden and pregnancy outcome. Three-quarters of the enrolled women were residents of the Port Pirie municipality; the other women lived in adjacent towns and countryside. At 14-20 weeks' gestation, the Port Pirie resident women had a mean blood lead concentration of 10.6 micrograms/dl, while the mean in the other (non-Port Pirie) women was 7.6 micrograms/dl. Similar differences were observed in maternal blood samples taken at 30-36 weeks, at delivery, and from the umbilical cord. These blood lead measures, in conjunction with information collected on other risk factors, were then examined in relation to pregnancy outcome. Among 749 pregnancies followed to completion, pre-term delivery was statistically significantly associated, in a dose-response manner, with maternal blood lead concentration at delivery. Mothers of late fetal deaths (stillbirths) had blood lead concentrations at 14-20 weeks' gestation similar to those of all the other women but had lower concentrations at delivery than the other women. Outcomes of pregnancy for which no association with blood lead was detected were spontaneous abortion, low birthweight (for births at term), intrauterine growth retardation, premature rupture of the membranes, and congenital anomalies.

Abortion, Spontaneous↗
PubMed1985

The Port Pirie cohort study. Blood lead concentrations in early childhood.

A cohort of over 600 children who were born between 1979 and 1982 and accounted for the great majority of all births in Port Pirie, South Australia, and its immediate environs, underwent capillary blood sampling at the ages of 6 months, 15 months, 2 years, and annually thereafter. The mean blood lead concentration (Pb-B) initially rose markedly, peaked at 2 years of age, and subsequently declined gradually at 3 and 4 years of age. No differences in Pb-B were observed between girls and boys. Secular trends in Pb-B at the age of 2 years that were observed in blood samples taken over the 1981-1984 period suggest that both the drought of 1982 and changes in community behaviour may have accounted for some of the age-related variation. The Pb-B was associated positively with surface soil lead concentrations, with a two-fold variation in mean Pb-B between residential zones within Port Pirie. Pb-B was higher in summer than in winter months at the ages of 6 and 15 months, but not at older ages. These findings suggest that lead in dust influences strongly blood lead concentrations in early childhood.

Age Factors↗
PubMed1982

Enzymatic diagnosis of the mucopolysaccharidoses: experience of 96 cases diagnosed in a five-year period.

We assessed lysosomal exohydrolase activities in homogenates of cultured skin fibroblasts and peripheral blood leucocytes of approximately 550 patients referred from throughout Australasia and suspected of having a mucopolysaccharidosis. Of these, 96 patients from 80 families were diagnosed as being homozygous deficient for a particular lysosomal enzyme activity. Clinical phenotype varied considerably within each of the enzyme-deficient states. This did not correlate with the level of "residual" enzyme activity in leucocyte or fibroblast homogenates. It was not always possible to discriminate heterozygotes from normal controls by enzyme assay of leucocyte or fibroblast homogenates in this study of a large number of mucopolysaccharidoses Type II by means of a single hair root assay system.

Clinical Enzyme Tests↗
PubMed1981

Combined analysis of acetylcholinesterase and alpha-fetoprotein improves the accuracy of antenatal diagnosis of neural-tube defects.

Acetylcholinesterase (AChE), butyrylcholinesterase (BChE) and alpha-fetoprotein (AFP) were measured in 293 amniotic fluids from the second and third trimesters of pregnancy in a prospective study of their diagnostic value in the detection of neural-tube defects (NTD). In normal samples, the mean AChE and BChE concentrations were 3.0 u/L (SEM = 9.1 u/L) and 15.2 u/L (SEM = 1.2 u/L) in the second trimester, and 1.6 u/L (SEM = 0.1 u/L) and 7.8 u/L (SEM = 0.6 u/L) in the third trimester. AFP levels fell throughout the second trimester to unmeasurable levels in the third. AChE levels were markedly elevated in samples from NTD pregnancies at all gestational ages, and a cut-off level of the mean + 3 SD optimally separated normal from abnormal samples. This cut-off correctly predicted 10 of 11 fetuses with neural lesions; there were three false positive results. A similar cut-off for AFP predicted nine of 11 cases of neural lesion with two false positive results. For BChE, a cut off of 50 u/L predicted eight of 11 neural lesions with two false positive results. The specificity, sensitivity, and predictive value positive (PVP) were calculated for each test. The assays of AFP and AChE were useful when used individually (PVP congruent to 80%), but a Bayesian combination of these two tests produced a superior PVP (98%). Because the cost of AChE assay is low, and the test is so simple, it is suggested that an AChE analysis should be performed whenever an amniocentesis is requested for the diagnosis of NTD.

Acetylcholinesterase↗
PubMed1980

Para-influenza pneumonia in DiGeorge syndrome two years after thymic epithelial transplantation.

A patient with DiGeorge syndrome developed pneumonia caused by para-influenza virus type 3 two years after immunological reconstitution with foetal thymic eptihelium. There was a transient reduction of mitogen-induced lymphocyte transformation at the time of the pneumonia. Although she recovered from the pneumonia, brochitis persisted and the virus could still be isolated from her pharyngeal secretions 3 1/2 months later.

Antibodies, Viral↗
PubMed1979

Screening of newborn infants for hypothyroidism. Two years' experience in South Autralia.

Over a period of two years, 40,000 newborn infants in South Australia have been screened for congenital hypothyroidism by the measurement of thyroxine and, on selected samples, of thyroid stimulating hormone. Samples were those obtained for an established newborn screening programme in the State. Eight infants with hypothyroidism were detected; in seven, this was due to congenital agenesis of the thyroid gland and one infant had residual thyroid tissue. A further three sick infants had abnormalities of thyroid function; in two, this was transient and reverted to normal after several weeks and the third infant died. Three infants had thyroxine-binding globulin deficiency.

Congenital Hypothyroidism↗
PubMed1979

Evaluation of a state-wide neonatal screening programme.

A screening programme which was already established to detect phenylketonuria in the newborn period in South Australia was extended to include screening for galactosaemia, homocystinuria, hereditary tyrosinaemia, histidinaemia, maple syrup urine disease and severe alpha 1-antitrypsin deficiency for a trial period. Later, screening for hypothyroidism was introduced. Results suggest that screening for galactosaemia and hypothyroidism are useful additions to the programme. Screening for trrosinaemia and alpha 1-antitrypsin deficiency produced a high number of requests for repeat samples, causing anxiety and no positive benefit to patients. Homocystinuria, an eminently treatable condition, was not detected, nor was maple syrup urine disease, a much less readily treatable condition. Histidinaemia was detected only once. Screening for tyrosinaemia, alpha 1-antitrypsin deficiency, maple syrup urine disease and histidinaemia has been discontinued. Newborn screening in South Australia currently includes tests for phenylketonuria, hypothydroidism, galactosaemia and homocystinuria.

Amino Acid Metabolism, Inborn Errors↗
PubMed1978

Successful restoration of immunity in the DiGeorge syndrome with fetal thymic epithelial transplant.

A 13-month-old girl presented with right upper lobe pneumonia and hypocalcaemic seizures: investigations showed hypoparathyroidism and impaired cell-mediated immune responses. Other features of the DiGeorge syndrome included hypertelorism, short philtrum of the lip, right-sided aortic arch, and aberrant origin of the left subclavian artery. Successful restoration of the immunodeficiency was achieved by transplantation of fetal thymic epithelium.

DiGeorge Syndrome↗
PubMed1978

Report of a mucopolysaccharidosis occurring in Australian aborigines.

The first 2 reported cases of a mucopolysaccharidosis occurring in an Australian aboriginal family are presented. Though these children had the characteristic morphological features of the Hurler syndrome, enzyme assay of cultured fibroblasts showed normal levels of alpha-L-iduronidase and decreased activity of arylsulphatase B. Thus, they represented the Hurler syndrome clinically, while they had the enzyme defect of the Maroteaux-Lamy syndrome, and they may represent a new severe form of the Maroteaux-Lamy syndrome. The parents of these children were first cousins. Though the children were not full blood aborigines, examination of the pedigree indicates that the gene originated in the common aboriginal family.

Australia↗
PubMed1976

Management of phenylketonuria: South Australian experience of 13 cases.

The management and present status of 13 children with phenylketonuria detected on the fifth day of life, who have been treated by diet thereafter for five to eight years, are discussed. In all 10 cases in which there has been continuous adequate dietary control of blood phenylalanine levels, the physical, social and mental development of the children has been normal. In some of these cases there is an unexplained discrepancy between the verbal and performance IQ scores. The present policy is to continue restricting the diet indefinitely, relaxation being permitted conditionally only after the age of seven years.

Australia↗
PubMedDate not supplied

Prenatal diagnosis of Zellweger's syndrome by chorionic villus sampling--and a caveat.

At 7.5 weeks gestation, two small chorionic villous biopsies were obtained from a woman at risk for Zellweger's cerebro-hepato-renal syndrome, and were separately established in culture. After 3 weeks, dihydroxyacetone phosphate acyltransferase (DHAP-AT) activity was measured in both cultures. The enzyme was markedly deficient in one cell strain and this was subsequently shown to have a male karyotype. However, the second culture had normal enzyme activity and a female karyotype. The pregnancy was terminated at 11.5 weeks gestation, and follow-up studies on fetal tissues confirmed a male fetus with markedly deficient DHAP-AT activity.

Acyltransferases↗
PubMedDate not supplied

Phosphorylation of isocitrate lyase in Escherichia coli.

Isocitrate lyase from Escherichia coli becomes phosphorylated in vitro by an endogenous kinase when partially purified extracts are incubated with [gamma-32P]ATP. Treatment of isocitrate lyase with histidine modifying reagents, and alkaline hydrolysis of in vitro phosphorylated enzyme indicated the presence of a phosphohistidine residue. Phosphorylation of isocitrate lyase can also occur in vivo, which indicates a possible regulatory significance of this modification. In addition to phosphorylation, isocitrate lyase is capable of incorporating label from both [alpha-32P]ATP and [14C]ATP suggesting that more than one type of covalent modification occurs on this enzyme. This report reviews the studies which have demonstrated the phosphorylation and modification of isocitrate lyase from Escherichia coli.

Escherichia coli↗
PubMedDate not supplied

Sociodemographic factors modifying the effect of environmental lead on neuropsychological development in early childhood.

A long-term prospective cohort study was conducted to examine the association between prenatal and postnatal exposure to environmental lead and childhood neuropsychological development. The possible interactive effects of blood lead and some covariates on early development were explored in this study. Our data suggest that gender of the child modifies the effect of lead on the neuropsychological development during early childhood. At the ages of 2 and 4 years, girls appear to be more sensitive than boys to the neuropsychological effects of lead. However, there is no significant modification of the effect of lead by some other covariates, such as parental smoking, socioeconomic status, home environment, birth weight, and the kind of infant feeding. Evidence of interactions between environmental lead exposure and other covariates in the causation of neuropsychological deficits in childhood underscores the desirability of considering both main effects and interactions in this area of research. Such effects, if confirmed, may have implications for public health intervention strategies.

Analysis of Variance↗