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Biomedical subjects

P J Anderson

Publications and source records attributed to P J Anderson.

At least 19 recordsLinked to original sources
PubMed1998

The feet in Pfeiffer's syndrome.

Broad toes are the classic clinical finding occurring in the feet in Pfeiffer's syndrome patients, but few cases undergo formal radiological assessment. However, the feet in other craniosynostosis syndromes resulting from mutations of the fibroblast growth factor receptor 2 gene have anomalies at many other sites within the feet, which raised the possibility that there may also be a wider range of anomalies other than broad big toes in the feet of those with Pfeiffer's syndrome. The object of this study was to assess prospectively the incidence and pattern of clinical and radiographic anomalies of the feet of patients with a confirmed diagnosis of Pfeiffer's syndrome. Twenty-two Pfeiffer's syndrome patients were examined both clinically and radiologically for anomalies of the feet. Clinical examination revealed broad big toes in 12 patients and syndactyly in 2. Radiographs of the feet were evaluated by a radiologist with an interest in skeletal dysplasia as well as by members of the Craniofacial team. A wider range of radiological than clinical anomalies involving the phalanges, metatarsals, and tarsals was seen. The severity of the anomalies observed ranged from normal to those resembling the feet of Apert's syndrome patients. Only 4 patients had radiologically normal feet. These radiographic findings suggest that there is a range of foot anomalies more extensive than the broad big toes, which are classically associated with Pfeiffer's syndrome.

Acrocephalosyndactylia↗
PubMed1998

Neuropsychological complications of IDDM in children 2 years after disease onset.

OBJECTIVE: To compare the neuropsychological profiles of children with IDDM with a community control group at two time points: 3 months after disease onset and 2 years after the baseline assessment. RESEARCH DESIGN AND METHODS: A total of 123 children (age 3-14 years) with recent IDDM onset were compared with 129 community control subjects, stratified for age and sex, on standardized measures of general intelligence, attention, speed of processing, memory, learning, executive skills, and behavioral adjustment soon after diagnosis and 2 years later. Exclusion criteria were premorbid evidence of central nervous system disease or trauma, or English not spoken in the home. RESULTS: There were no differences between children with IDDM and control subjects on any measure at the initial assessment 3 months after disease onset. Two years later, children with IDDM tended to show a less positive change, relative to control subjects, in their standardized scores on measures of general intelligence, and significantly so on the vocabulary (P < 0.01) and block design (P < 0.05) subtests. Multivariate group differences were also apparent on speed of processing (P < 0.05) and learning (P < 0.01) subtests, reflecting smaller developmental gains in the children with IDDM when compared with control subjects. CONCLUSIONS: The findings are consistent with previous reports, suggesting that IDDM is associated with an increased risk of mild neuropsychological dysfunction. The skills most affected in this cohort were information processing speed, acquisition of new knowledge, and conceptual reasoning abilities. Clinicians and educators should be made aware of the risk of specific neuropsychological deficits in children with IDDM.

Adolescent↗
PubMed1997

Functional identification of calcium binding residues in bovine alpha-lactalbumin.

The functional role of previously identified calcium binding residues in alpha-lactalbumin (alpha-LA) was investigated by site-directed mutagenesis. Mutation of D82 to alanine did not effect the binding affinity for calcium, the protein structure, or its function in the lactose synthase assay, suggesting that this aspartate side chain is not essential for calcium binding or structural stabilization. In contrast, mutation of either D87 or D88 to alanine completely eliminated the strong calcium binding and altered alpha-LA as shown by several spectroscopically derived properties such as near- and far-UV CD and intrinsic fluorescence studies. These latter two mutants displayed significantly reduced abilities to stimulate lactose synthase activity (<3.5% of the maximal rate). Additionally, residues K79 and D84, which chelate calcium by backbone carbonyls, were mutated to alanine. K79A lost approximately 50% of its tertiary structure and stability (as determined by CD) but retained full calcium binding activity, indicating that at least the lysine side chain does not influence the carbonyl-mediated calcium coordination. In contrast, D84A lost approximately 25% of its tertiary structure and stability which was accompanied by a modest reduction in calcium affinity. Both mutants were able to stimulate normal lactose synthase activity. The triple mutant, D82A/D87A/D88A alpha-LA, lost its ability to bind calcium, similar to D87A and D88A. These studies clearly demonstrate the importance and variation of side chain interactions, which might be the seminal event in the establishment of the correct calcium binding loop conformation, possibly to stabilization and final folding of the overall protein structure.

Animals↗
PubMed1997

The cervical spine in Crouzon syndrome.

STUDY DESIGN: All cervical spine radiographs of 44 patients with Crouzon syndrome treated at Great Ormond Street Hospital during the past 10 years were studied. OBJECTIVES: To assess the incidence and pattern of cervical spine abnormalities of patients with a confirmed diagnosis of Crouzon syndrome, but particularly regarding progressive fusion. SUMMARY OF BACKGROUND DATA: Previous studies into the cervical spine anomalies in those with Crouzon syndrome have shown an increased incidence of congenital abnormalities compared with the normal population. There is some suggestion from previous studies that cervical spine fusions are progressive in nature. METHODS: All radiographs were reviewed by the craniofacial team, along with a single pediatric radiologist with experience in assessment of skeletal dysplasias. RESULTS: Radiologic abnormalities included "butterfly" vertebrae and fusions of the bodies and the posterior elements. Evidence of fusion was present in eight of 44 (18%) of patients. C2-C3 and C5-C6 were almost equally affected. Block fusions involving multiple vertebrae were seen. Analysis of sequential studies in 16 patients showed evidence of progression in five. CONCLUSIONS: These results reveal an incidence of fusions that is lower than reported previously. There is radiologic evidence from serial studies that the fusions are progressive, and because these patients are children, the fusion process may not be complete, which may account for the lower incidence of fusions than in previous studies. The pattern of fusions is different from that in earlier studies, which may be a result of the method of diagnosis because this population is less likely to include atypical forms of other syndromes (which have a higher incidence of cervical fusions, particularly at C2-C3). Regarding other congenital anomalies, it appears that butterfly vertebrae are especially prevalent in association with Crouzon syndrome.

Cervical Vertebrae↗
PubMed1997

Non-invasive continuous arterial pressure, heart rate and stroke volume measurements during graded head-up tilt in normal man.

The haemodynamic effects of head-up tilt (HUT) at different tilt angles were investigated non-invasively in eight normal male subjects. Mean arterial pressure (MAP; by Ohmeda Finapres 2300), stroke volume (SV) and heart rate (HR; by BoMed NCCOM3-R7S) were continuously recorded whilst performing a series of HUTs (55 degrees, 10 degrees, 20 degrees, 30 degrees and 55 degrees) lasting 3 min each. The response to HUT was proportional to the sinc of the tilt angle. The magnitude of the response varied between subjects. HUT to 55 degrees resulted in mean (95% confidence limits) increases in MAP by 16 (+/-16)% and HR by 11 (+/-24)% and a decrease in SV by -25 (+/-22)%. These results were repeatable after 30 min. At small tilt angles, i.e. < or = 20 degrees, MAP did not change and HR decreased by -3 (+/-4)%. A detailed analysis revealed immediate dynamic (0-30 s), late dynamic (30-90 s) and plateau (after 90 s) phases in the response to HUT. In conclusion, HUT produces reproducible haemodynamic effects, although differences exist among subjects. A detailed analysis of these effects can be successfully performed using non-invasive methods.

Adult↗
PubMed1997

Single-dose pharmacokinetics of paracetamol and its conjugates in Chinese non-insulin-dependent diabetic patients with renal impairment.

OBJECTIVE: A single oral dose of paracetamol (20 mg.kg-1) was given to 38 Chinese patients with non-insulin-dependent diabetes mellitus (NIDDM) who had either normal renal function or varying degrees of renal impairment, with creatinine clearances ranging from 4 to 123 ml.min-1.1.73 m-2. The plasma and urinary concentrations of paracetamol and its major metabolites were measured by high-performance liquid chromatography (HPLC). RESULTS: The absorption and elimination of paracetamol were unaffected by renal impairment. However, the area under the plasma concentration time curve and the elimination half-life of paracetamol metabolites increased significantly with worsening renal insufficiency. Mean renal clearances of paracetamol and its conjugates were significantly reduced in these subjects. There was no evidence of altered metabolic activation with renal impairment. CONCLUSION: The results demonstrate that paracetamol disposition is minimally affected by diabetic nephropathy; however, extensive accumulation of conjugates may occur.

Acetaminophen↗
PubMed1997

Hand anomalies in Crouzon syndrome.

OBJECTIVE: To review the hand radiographs of patients with Crouzon syndrome, to look for extracranial manifestations of the condition at this site. DESIGN: The hand radiographs of those with Crouzon syndrome attending the Craniofacial Service at Great Ormond Street between 1985 and 1996 were reviewed. RESULTS: Thirty-three patients underwent a total of 34 radiographs, one patient having had a serial study. This revealed a range of minor anomalies. Most striking was the presence of carpal fusions in four cases, a feature which has not previously been reported. CONCLUSION: The hands of Crouzon syndrome may have anomalies including carpal fusions, and these results are evidence that the condition may produce subtle effects on the hands.

Adolescent↗
PubMed1997

Development of a radiopharmaceutical activity schedule for technetium-99m dimercaptosuccinic acid in children based on image quality criteria.

The aim of this study was to determine an activity schedule (amount of administered activity in relation to body weight) for technetium-99m dimercaptosuccinic acid examinations in children, from information present in renal scintigraphic images. Scans from 48 children (5 weeks to 14.8 years old) were graded for image quality according to the clarity of both kidney outline and internal structure. Numerical image data (kidney and background counts, signal-to-noise ratio) were associated with these subjective gradings to formulate three criteria, specifying the required values of the above-measured parameters to yield optimum grades of image quality. When applied to derived functions, a kidney uptake of 20% was required to satisfy the criterion based on the signal-to-noise ratio. Using this value with the other two criteria predicts the form of the weight-dependent activity schedule as a function of imaging time. Examples of schedules for imaging times of 300 and 600 s are compared with a schedule based on surface area.

Adolescent↗
PubMed1997

Anomalous venous drainage in a case of non-syndromic craniosynostosis.

The authors describe the clinical and radiological findings in a case of non-syndromic craniosynostosis affecting multiple sutures, in which the intracranial venous drainage was grossly anomalous. Investigation by magnetic resonance imaging and angiography revealed that almost all of the intracranial venous blood was draining from the dural sinuses transosseoussly via enlarged emissary veins to the external jugular veins and the vertebral veins. Although present, both internal jugular veins were small. This discovery represented a contraindication for the vault expansion surgery that had been recommended as treatment for the patient's raised intracranial pressure, and it has important implications for the management of all types of craniosynostosis.

Cerebral Angiography↗
PubMed1997

Assessment of drainage in PUJ dilatation: pelvic excretion efficiency as an index of renal function.

Renal function is important when assessing the response of a dilated renal pelvis to a diuretic stimulus. Yet there is little in the literature to suggest how this should be undertaken. Our aim was to develop a model which we have called pelvic excretion efficiency (PEE). The PEE, which may be used to assess drainage, is a mathematical model of the ratio of the total kidney excretion to the total amount of isotope extracted from the blood by the kidney. Thirty-three children with a prenatal diagnosis of unilateral renal pelvic dilatation (PUJ) were treated conservatively after birth. As a group, they underwent a total of 164 diuretic DTPA renograms up to the age of 72 months. Drainage was assessed as the response to frusemide (defined as the time for the corrected renal curve to fall to 75% of the maximum value in the frusemide part of the study; T75), response to bladder emptying, a change of posture after frusemide (PM), and PEE. The contralateral normal kidney showed a combination of both 'good' T75 and PM drainage in 51% of renograms while the PEE showed drainage in all. The affected kidney with renal pelvic dilatation showed a combination of both 'poor' T75 and PM drainage in 42% of renograms. The PEE was low in 99% of these 'poor drainage' renograms. The PEE, the ratio of the mathematical model of renal uptake to excretion, is readily calculated and may be a more accurate and specific technique to assess drainage on diuretic renography.

Child↗
PubMed1997

The cervical spine in Saethre-Chotzen syndrome.

Twenty patients with a diagnosis of Saethre-Chotzen syndrome had their cervical spine radiographs reviewed. Radiologic abnormalities including vertebral fusion were present in 9 of the 20 patients. Fusion of both the vertebral bodies and the posterior elements was noted, although the latter site was more common. C2-3 was the level most commonly involved, although other levels were recorded. Analysis of sequential radiographs in nine patients revealed evidence of progression in seven patients. In those studies in children aged under 2 years, only 1 of 18 films showed evidence of fusion, while in those over 2 years of age, 10 of 12 showed evidence of fusion. These results reveal that the incidence of cervical anomalies in Saethre-Chotzen syndrome is greater than that in the general population. There is both direct and indirect evidence that the vertebral fusions are progressive during childhood.

Blepharoptosis↗
PubMed1997

Visceral fat and cardiovascular risk factors in Chinese NIDDM patients.

OBJECTIVE: The interrelations between obesity, glucose intolerance, hypertension, dyslipidemia, and insulin resistance are well recognized. These relationships are of particular interest in Hong Kong's Chinese population, in whom increasing affluence has coincided with a marked increase in the prevalence of NIDDM. We designed a pilot study to examine the relationships between visceral fat and cardiovascular risk factors in Chinese NIDDM patients. RESEARCH DESIGN AND METHODS: We studied 21 Chinese NIDDM patients whose visceral fat was quantified by magnetic resonance imaging. Cardiovascular risk factors including plasma lipids and 24-h ambulatory blood pressure (BP) were measured. In addition, insulin resistance was determined by a short insulin tolerance test (SITT). RESULTS: Increased visceral adiposity was significantly correlated with plasma triglycerides (r = 0.63, P = 0.004), the total cholesterol/HDL cholesterol ratio (r = 0.61, P = 0.008), the urinary albumin/creatinine ratio (r = 0.49, P = 0.04), and decreased insulin sensitivity as measured by the SITT (r = 0.47, P = 0.03). When the data were analyzed by tertiles, increasing visceral fat area was associated with higher plasma triglycerides, lower HDL cholesterol, and a smaller plasma glucose decrement during the SITT. In addition, the diurnal rhythm in BP and heart rate tended to be best preserved in those with the least visceral obesity. CONCLUSIONS: This pilot study demonstrates that visceral fat accumulation is associated with dyslipidemia, hypertension, insulin resistance, and albuminuria in Chinese patients with NIDDM.

Adipose Tissue↗
PubMed1997

Osteomyelitis occurring in the zygomatic bone.

Osteomyelitis of bones in the middle third of the face is rare, especially in westernized populations. The actiology is usually due to odontogenic sources or infected fracture sites. An unusual case of osteomyelitis of the zygomatic bone resulting from the use of radiotherapy in the management of recurrent basal cell carcinoma is presented. This illustrates a late complication of therapy for a cancer which commonly occurs in the head and neck region and is rapidly increasing in incidence in the UK.

Basal Cell Carcinoma↗