Biomedical subjects

Peter J Anderson

Publications and source records attributed to Peter J Anderson.

27 records · Page 2Linked to original sources

PubMed2005

Management of facial dysmorphogenesis in nemaline myopathy: a case report.

Nemaline myopathy is a rare congenital muscle disease, which is clinically and genetically heterogeneous. Both neonatal and adult onset can occur; in those with neonatal onset, the resulting muscle weakness can also afflict the facial musculature and hence influence facial growth and development. This article reports on a case in which no orthodontic intervention was undertaken during childhood and adolescence. An early decision was made to treat the facial dysmorphogenesis surgically once skeletal maturity had been reached. The authors discuss and illustrate the untreated facial growth in this condition and the surgical outcome following orthodontic treatment and orthognathic surgery.

Adolescent↗

PubMed2004

Neuropsychological functioning in children with early-treated phenylketonuria: impact of white matter abnormalities.

Impact of white matter abnormalities (WMAs) on neuropsychological functioning in children with early-treated phenylketonuria (ETPKU) was examined. Children with ETPKU (20 males, 12 females, mean age 11 years 2 months, SD 3 years 6 months) and controls (20 males, 14 females, mean age 10 years 4 months, SD 3 years 1 month) aged 7 to 18 years were assessed using tests of attention, processing speed, memory and learning, executive function, and academic achievement. Those with ETPKU, exhibiting WMAs extending into subcortical/frontal regions (n=14), displayed significant impairments in a number of domains. Children with ETPKU but no WMAs (n=6), or pathology restricted to the posterior periventricular region (n=12), displayed only mild deficits. Concurrent phenylalanine levels correlated weakly with cognitive parameters, whereas lifetime phenylalanine levels were associated with deficits in several cognitive domains. Impairments in children with extensive WMAs are consistent with compromised neural transmission, which is characterized by dysmyelination. However, children with no detectable, or mild WMAs, also displayed cognitive problems, indicating that neuropsychological functioning in children with ETPKU is determined by a complex interaction of biological and environmental factors.

Adolescent↗

PubMed2004

Mandibular lengthening by distraction for airway obstruction in treacher-collins syndrome: the long-term results.

Mandibular lengthening by distraction was performed in a 6-year-old severely affected Treacher-Collins syndrome patient who was tracheostomy dependent. As previously reported, this procedure permitted tracheostomy removal once distraction was complete. Now that the patient is skeletally mature, the long-term results of this intervention are reported with regard to his clinical outcome and an assessment of the anatomical changes in the upper airway during growth. Although the distraction could be considered a success in that it enabled permanent decannulation and improved the minimum cross-sectional area of the upper airway, there was no further increase in the minimum cross-sectional area of the upper airway during childhood growth. It is significant that the abnormal growth pattern of the mandible, which is characteristic of this syndrome, did not alter from its preoperative pattern once distraction was completed.

Airway Obstruction↗

PubMed2004

Intracranial volume measurement of metopic craniosynostosis.

The authors report 32 patients with nonsyndromic isolated metopic synostosis who have undergone evaluation of their intracranial volumes. Twenty-five were male and seven were female. The measured intracranial volumes were compared with normal age-corrected values established in the authors' unit, and any differences were noted. The authors found that, although there was a range of intracranial volumes, in the male patients, intracranial volumes were significantly smaller than those found in the normal population (P < 0.05). However, this result was not found in the smaller female sample. These results contrast with those of smaller earlier studies, but the authors conclude that intracranial volumes are smaller than average for age-corrected normal values; this finding highlights the need for volume expansion in conjunction with cranial reshaping.

Case-Control Studies↗

PubMed2004

Executive functioning in school-aged children who were born very preterm or with extremely low birth weight in the 1990s.

OBJECTIVE: To determine the frequency, nature, and severity of executive dysfunction (EDF) at 8 years of age in extremely low birth weight (ELBW)/very preterm infants who were born in the 1990s, compared with normal birth weight (NBW) control subjects. METHODS: A geographically determined cohort study was conducted in Victoria, Australia. The ELBW/very preterm cohort comprised 298 consecutive survivors at 2 years of age who had gestational ages <28 completed weeks or birth weights <1000 g and were born during 1991-1992. The NBW cohort comprised 262 randomly selected children of birth weight >2499 g matched on date of birth, gender, ethnicity, and health insurance status. The participation rate was 92% (275 of 298) for the ELBW/very preterm cohort and 85% (223 of 262) for the NBW cohort. Cognitive and behavioral measures of executive functioning were administered. RESULTS: The ELBW/very preterm cohort exhibited significant EDF compared with their NBW peers in all areas assessed. The cognitive assessment revealed global impairment rather than deficits in specific executive domains. The ELBW/very preterm children also displayed more behavioral problems indicative of EDF than the NBW children. Severe impairments were exhibited in only a small minority of ELBW/very preterm children. No statistical conclusions were altered after adjustment for sociodemographic variables or when children with substantial neurosensory impairment were excluded. CONCLUSIONS: School-aged children who were born in the 1990s and were very preterm or had ELBW are at greater risk for developing EDF and require ongoing neuropsychological review throughout middle childhood.

Child↗

PubMed2003

Teratomas of the head and neck region.

BACKGROUND: Teratomas are exceptionally rare malformations in the head and neck region. They are mostly benign but as a direct result of their rarity, most clinician's experience of these tumours is very limited, and consequently most of the associated literature consists of single case reports. In this paper, however, all the cases managed by a major Craniofacial Unit (the Australian Craniofacial Unit) were reviewed to attempt to identify common problems encountered in their management. MATERIAL AND METHODS: All cases managed by the Australian Craniofacial Unit over the last 25 years were reviewed. In total a series of nine cases was identified, but two were seen and operated on in overseas centres and the data in these cases were incomplete, and have been excluded from the study. Case note, radiology and pathology review was undertaken to collect data. RESULTS: In total a series of seven cases was identified as suitable for inclusion in this study. Six of these have had a minimum of 9 years follow-up, three having completed growth. CONCLUSION: The initial and subsequent management demonstrates that these tumours when benign can be successfully removed, but depending on the affected site may require continued multidisciplinary management until growth has finished.

Brain Neoplasms↗

PubMed2002

A flavoprotein encoded in Selenomonas ruminantium is characterized after expression in Escherichia coli.

Selenomonas ruminantium is an obligate anaerobe that is very important for the provision of vitamin B12 to ruminants, which are particularly dependent upon this cofactor. One important use for vitamin B12 in anaerobic bacteria is for the utilization of glycerol as carbon source. A new flavoprotein has been found expressed by Escherichia coli from a plasmid created as part of a gene library of S. ruminantium. The 2.5-kb fragment of chromosomal DNA responsible for protein expression contains parts of two operons. Only one polypeptide (the flavoprotein) encoded by the S. ruminantium DNA is produced in E. coli in large amounts. The gene for the flavoprotein has been identified and is probably transcribed as part of an operon involved in glycerol metabolism in S. ruminantium. The flavoprotein has been purified and its molecular properties have been examined. Sequence analysis showed that this protein is a divergent member of the family of nitroreductases. Pure protein is a homodimer with a molecular weight of 44,500, containing one molecule of FMN per dimer. Like other nitroreductases, this protein forms a complex with pyridine nucleotide (NADPH), but unlike other nitroreductases, it fails to be reduced in this complex at a biologically significant rate. It has none of the common catalytic properties of other members of the nitroreductase family.

Amino Acid Sequence↗

PubMed2002

The value of radionuclide studies in children with autosomal recessive polycystic kidney disease.

PURPOSE: To describe and analyze the appearances of autosomal recessive polycystic kidney disease (ARPKD) on Tc-99m DMSA and Tc-99m HIDA scintigraphy. MATERIALS AND METHODS: The authors evaluated scintigraphic findings for 13 boys and 9 girls (age range, 2 months to 22.75 years; mean, 7.5 years) with ARPKD. Fourteen children underwent Tc-99m DMSA and 20 underwent Tc-99m HIDA scintigraphy according to European guidelines. Kidney outline, internal structure, tracer uptake, and differential function were analyzed on Tc-99m DMSA images, whereas relative liver lobe sizes, hepatocyte tracer uptake, time to peak, and excretion into the biliary tree and gut were evaluated on Tc-99m HIDA scans. RESULTS: On Tc-99m DMSA images, loss of kidney outline and internal structure was seen in 75% of the scans, and patchy tracer uptake with focal defects throughout the kidneys, particularly at the poles, was evident in 93%. In 85% of the cases, the Tc-99m DMSA changes did not correlate with the ultrasonographic findings where the kidneys are uniformly affected. Characteristic findings on Tc-99m HIDA scans were enlarged left liver lobe in 80%, a delay in maximal hepatocyte uptake in 68%, delayed tracer excretion into the biliary tree in 32% (with stasis in the prominent intrahepatic biliary ducts in 50% or pooling into the segmentally dilated biliary ducts in 25%), and delayed excretion into the gut in 40% of patients. CONCLUSIONS: In a child with clinically enlarged kidneys that appear diffusely hyperechoic on ultrasound, the appearances on Tc-99m DMSA imaging strongly support the diagnosis of ARPKD. The Tc-99m HIDA findings, especially of an enlarged left lobe of the liver with bile stasis or dilatation, further support the diagnosis.

Adolescent↗

PubMedDate not supplied

Analysis of intracranial volume in apert syndrome genotypes.

OBJECTIVE: Apert syndrome is caused by a mutation of the fibroblastic growth factor type 2 gene and in nearly all of the cases where the mutation has been identified it occurs in one of two adjacent sites of the gene, either position 252 or position 253. There is currently uncertainty whether a worse neurosurgical outcome occurs in association with a particular genotype. We investigated whether there were clinically subtle (but relevant) morphological differences in the craniofacial skeleton, which would result in differences in the intracranial volume, which might account for apparent differences in surgical outcome. METHOD: Three-dimensional CT scans of pre-operative Apert syndrome whose genotype had been identified had the intracranial volume measured using the Cavalieri estimator with correction for partial voluming effects. The values were compared to age and sex normals and then the two genotypes compared. RESULTS: Intracranial volumes were measured for 22 cases, 16 with the 252 mutation and 6 with the 253 mutation. CONCLUSIONS: All cases except two had greater than their sex- and age-adjusted mean normal intracranial volumes. For the 252 and 253 genotypes there were no discernible differences in intracranial volumes between the two genotypes.

Acrocephalosyndactylia↗