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Biomedical subjects

J Giles

Publications and source records attributed to J Giles.

At least 19 recordsLinked to original sources

Adriamycin effects on the chick embryo.

Adriamycin is an anthracycline, anti-neoplastic drug with known teratogenic effects on foetal rats in what is known as the Adriamycin rat model (ARM). This includes conditions similar to those in newborn humans, known collectively as the VACTERL association. This comprises vertebral (V), anorectal (A), cardiac (C), tracheoesophageal (TE), renal (R) and limb (L) anomalies. We designed this study to test the hypothesis that the administration of Adriamycin to chick embryos would cause similar anomalies to those in the VACTERL association seen in the ARM. Fertilized Ross eggs received Adriamycin doses from 2-50 microg into the air sac and from 0.9-6 microg into the albumin. Administration varied from day 0-3 (D(0-3)) with D(0) being the first day of incubation. Control eggs received saline. Embryos were incubated at 38 degrees C and a relative humidity of 70%. Embryos were recovered on D(14), paraffin-embedded and transverse sections studied for morphological abnormalities. In the air sac group ( n=142), 71% of Adriamycin embryos survived versus 86% of controls (n=29). In the albumin group (n=121), 42% of Adriamycin embryos survived versus 55% of controls (n=69). No embryos demonstrated anomalies consistent with the VACTERL association. Ventral defects affected 1% of surviving Adriamycin embryos versus 4% of controls in the air sac group. In the albumin group, 19.8% of surviving Adriamycin embryos had ventral defects compared to 15.7% of surviving controls. Anophthalmia affected 1% of the surviving embryos in the Adriamycin air sac group and 2% of the Adriamycin albumin group. No controls developed anophthalmia. Exencephaly affected 2% of the survivors in the Adriamycin air sac group but none of the albumin group or controls. The administration of Adriamycin to chick embryos in comparable doses and times to those used in the ARM does not appear to produce comparable effects in relation to developmental anomalies, such as the VACTERL association. Despite examining different administration routes and mimicking the ARM, by giving Adriamycin to embryos at gastrulation, we were unable to re-create the anomalies seen in the ARM.

Abnormalities, Drug-Induced↗

Quantifying relative afferent pupillary defects using a Sbisa bar.

AIM: To compare the Sbisa bar (Bagolini filter bar) with neutral density filters (NDF) in quantifying relative afferent pupillary defects (RAPD). METHODS: 11 patients with a RAPD were graded and a neutral density filter bar was used to quantify the RAPD. This was repeated using the Sbisa bar. The Sbisa bar (Bagolini filter bar) is used by orthoptists to quantify density of suppression in amblyopia and is of a similar construct to NDFs. Before this clinical part of the study the luminance for each filter was measured, which enabled a direct comparison to be made. RESULTS: In the analysis of patients with RAPD a high correlation was found when comparing the Sbisa and NDF bars r = 0.95. This was statistically significant (p = <0.001). Correlation was also high when the luminance values for the filters were substituted for the clinical readings (r = 0.92; p=<0.001). CONCLUSION: The Sbisa bar is a comparable instrument to the NDF bar in measuring RAPD. Its availability in the clinical situation makes it a practical choice.

Female↗

Low dose computed tomography in suspected acute renal colic.

AIM: To evaluate whether computed tomography (CT) of the renal tract in suspected renal colic using reduced exposure factors maintains diagnostic accuracy. METHODS: Prospective multi-centre cohort study. Patients with suspected renal colic were examined using computed tomography (CT) of the renal tract followed by intravenous urography (IVU) in four different centres with five different CT systems. RESULTS: Sixty-nine patients with suspected renal colic had CT of the renal tract followed by IVU. CT was performed with reduced exposure factors, giving a mean CT effective dose of 3.5 (range 2.8-4.5) mSv compared with 1.5 mSv for IVU. Ureteric calculi were detected in 43 patients: CT and IVU detected 40 (93%) ureteric calculi. CT identified other lesions causing symptoms in five patients and identified renal calculi in 24 patients. IVU identified renal calculi in six patients and made false positive diagnosis of renal calculi in seven patients. Mean examination time for CT was 5 minutes and for IVU was 80 minutes. CONCLUSION: CT examination at reduced exposure factors maintains the diagnostic accuracy recorded in other series.

Acute Disease↗

Null alleles at the Huntington disease locus: implications for diagnostics and CAG repeat instability.

PCR amplification of the CAG repeat in exon 1 of the IT15 gene is routinely undertaken to confirm a clinical diagnosis of Huntington disease (HD) and to provide predictive testing for at-risk relatives of affected individuals. Our studies have detected null alleles on the chromosome carrying the expanded repeat in three of 91 apparently unrelated HD families. Sequence analysis of these alleles has revealed the same mutation event, leading to the juxtaposition of uninterrupted CAG and CCG repeats. These data suggest that a mutation-prone region exists in the IT15 gene bounded by the CAG and CCG repeats and that caution should be exercised in designing primers that anneal to the region bounded by these repeats. Two of the HD families segregated null alleles with expanded uninterrupted CAG repeats at the lower end of the zone of reduced penetrance. The expanded repeats are meiotically unstable in these families, although this instability is within a small range of repeat lengths. The haplotypes of the disease-causing chromosomes in these two families differ, only one of which is similar to that reported previously as being specific for new HD mutations. Finally, no apparent mitotic instability of the uninterrupted CAG repeat was observed in the brain of one of the HD individuals.

Aged↗

Trainee specialist: meeting the needs of service provision and career development.

A two-year modular training scheme to enable qualified speech and language therapists (SLTs) to become specialists in the field of acquired neurological disorders in adults was set up to address problems of: difficulty recruiting to senior posts; lack of opportunity for inexperienced therapists to gain experience in this field and the need for structured supervision. The paper describes how time was found to devise and implement the modular Nine Box System, the problems encountered, the advantages and disadvantages of the scheme as a whole and future developments. The scheme has potential to meet the needs of managers in creating a pool of experienced specialists to recruit to senior posts. It meets the needs of junior SLTs in providing a structured means of preparing for specialisation with guaranteed supervision.

Aphasia↗

Arteriovenous fistulas in renal transplants: color Doppler ultrasound observations.

One hundred twenty-six new renal transplants were scanned regularly with color Doppler ultrasound (CDU). In 22 (17.5%) of the grafts there was evidence of postbiopsy arteriovenous (AV) fistula during the first 6 months postoperatively. In 14 cases the fistula closed spontaneously. In the remaining eight, the fistula was still present up to 24 months later (four cases) or until the graft failed (four cases). Additionally, 163 established grafts were scanned for evidence of vascular abnormality. AV fistulas were observed in 15 grafts (8%). Circulatory complications of fistulas observed include vascular steal and a possible association with graft vein and artery stenosis.

Arteriovenous Fistula↗

Aortic dissection presenting as acute leg ischaemia.

Lower limb ischaemia as the only or main clinical manifestation of aortic dissection is a rare event. Two cases are presented where this occurred resulting in attempted embolectomy before the correct diagnosis was made. The diagnosis should be considered when embolectomy fails to retrieve thrombus and when angiography demonstrates spiral lucencies within the lumen of large vessels or non-filling of major vascular branches. The value of pre-operative angiography is emphasized.

Aged↗