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Biomedical subjects

R P Davies

Publications and source records attributed to R P Davies.

At least 19 recordsLinked to original sources
PubMed2006

Use of routine computed tomography brain scanning of psychiatry patients.

The aim of this study was to evaluate the usefulness of CT of the brain in patients presenting with a psychiatric condition without focal neurological signs. The reports of 397 consecutive CT brain scans of patients presenting to two acute tertiary hospital psychiatric services over a 2-year period were assessed retrospectively. Of the 397 patients, 241 had psychosis, 87 had depression, 44 had bipolar affective disorder, seven had alcohol dependence, five had dementia, and the remaining 13 had a variety of diagnoses including personality disorder and transient ischaemic attack. Findings on 377 (95%) of the CT scans showed no abnormality. Specific abnormalities were described in 20 (5%) of the CT scans. Three scans showed non-specific minor abnormalities, which, when followed up by MRI, showed no relevant abnormality. All the abnormalities shown on CT were considered to be clinically unrelated to the patient's psychiatric condition. In conclusion, the pretest probability of finding a space-occupying lesion or other pertinent abnormality in patients presenting with psychiatric illnesses in this retrospective study appears not to be greater than that of the general population. The outcome of this study could be implemented to develop a clinical pathway for limiting assessment by CT for possible organic pathology in acute psychiatric illness.

Adolescent↗
PubMed2002

Gadolinium-enhanced computed tomographic aortography.

Radiographic contrast agents using gadolinium have a better safety profile and photoelectric effect than iodinated contrast, allowing use where iodinated contrast is contraindicated. A case of gadolinium-enhanced computed tomographic aortography (CTA) for suspected thoracic dissection is reported. Aortic enhancement was sufficient for confident exclusion of an intimal flap. The findings were later confirmed by MRI. Vascular enhancement diminished below the diaphragm and tissue enhancement was minimal. Gadolinium diethylenetriamine penta-acetic acid (Gd-DTPA) may be used for CTA of the thoracic aorta, where the use of iodinated contrast is contraindicated. Multi-slice CT may expand the role of gadolinium enhancement in the future.

Aortic Dissection↗
PubMed2001

Oxygen capture by lithiated organozinc reagents containing aromatic 2-pyridylamide ligands.

The sequential reaction of ZnMe2 with a 2-pyridylamine (HN(2-C5H4N)R, R = Ph: 1; 3,5-Xy (=3,5-xylyl): 2; 2,6-Xy: 3; Bz (=benzyl): 4; Me: 5), tBuLi and thereafter with oxygen affords various lithium zincate species, the solid-state structures of which reveal a diversity of oxo-capture modes. Amine 1 reacts to give both dimeric THF [Li(Me)OZn[N(2-C5H4N)Ph]2] (6), wherein oxygen has inserted into the Zn-C bond of a [MeZn[N(2-C5H4N)-Ph]2] ion, and the trigonal Li2Zn complex, bis(OtBu)-capped (THF x Li)2-[[(mu3-O)tBu]2Zn[N(2-C5H4N)Ph]2] (7). The structural analogue of 6 (8) results from the employment of 2, while the use of more sterically congested 3 yields a pseudo-cubane dimer [(THF x [Li(tBu)OZn(OtBu)Me]]2] (9) notable for the retention of labile Zn-C(Me). Amines 4 and 5 afford the oxo-encapsulation products [mu4-O)Zn4[(2-C5H4N)-NBz]6] (10b), and [tBu(mu3-O)-Li3(mu6-O)Zn3[(2-C5H4N)NMe]6] (11), respectively, with concomitant oxo-insertion into a Li-C interaction resulting in capping of the fac-isomeric (mu6-O)M3M'3 distorted octahedral core of the latter complex by a tert-butoxide group.

Journal Article↗
PubMed2001

Percutaneous ultrasound-guided thrombin injection for coagulation of post-traumatic pseudoaneurysms.

Most peripheral pseudoaneurysms are iatrogenic or, less commonly, post-traumatic. Pseudoaneurysms are associated with characteristic findings of a pulsatile palpable mass and an audible to and fro murmur. The diagnosis can be easily confirmed using colour duplex ultrasound. A successful treatment for the coagulation of pseudoaneurysms as an alternative to ultrasound-guided manual compression is described. The method involves ultrasound-guided direct percutaneous injection of a small quantity of thrombin through a fine needle. This technique is simple and effective, resulting in rapid occlusion of the pseudoaneurysm. Two cases are reported.

Adult↗
PubMed1999

Historical declines in tuberculosis in England and Wales: improving social conditions or natural selection?

OBJECTIVES: A reinvestigation of the relationship between the decline of tuberculosis and improvement in social conditions in England and Wales during Victorian times. DESIGN: A retrospective study using data published in the annual reports of the Registrar General from 1853 to 1910. MEASURES ASSESSED: The diseases studied, in addition to tuberculosis were dysentery and cholera, including their total and infant mortality. Social conditions were evaluated from earnings and population density per house. RESULTS: Tuberculosis mortality declined at an annual average rate of 1.71% (95% confidence interval [Cl] 0.77-2.63), whereas total mortality, infant mortality and mortality from cholera and dysentery and house population density showed no statistically significant decline over the same period. Real earnings increased by 1.05% (95% CI 0.29-1.81). CONCLUSION: Improving social conditions do not provide the total explanation for the decline in tuberculosis during Victorian times. Other factors, principally natural selection, probably played a role. Part of the current increase in tuberculosis may be caused by effective drug therapy eliminating natural selection.

Cause of Death↗
PubMed1997

Tandem balloon dilatation for childhood achalasia.

BACKGROUND: There are no previous reports of tandem balloon dilatation in childhood achalasia. OBJECTIVE: To report the treatment of four cases of paediatric achalasia using tandem balloon dilatation of the lower oesophageal sphincter. A review of the literature since 1986 was undertaken to compare outcomes of balloon dilatation and surgery. MATERIALS AND METHODS: A retrospective review of the patients diagnosed with this condition and treated at our institution over the past 6 years: all four patients were treated by balloon dilatation of the lower oesophageal sphincter using two or three balloons in tandem. The definition of technical success was demonstration of a waist at 1-1.5 atmospheres of inflation pressure followed by abolition of the waist at higher pressures. Where this was unable to be achieved using a single balloon, two or three balloons in tandem were used. RESULTS: No patient required oesophagomyotomy, and symptomatic control has been good to excellent in three of four patients. No significant side effects were encountered. CONCLUSIONS: Balloon dilatation and surgery have similar success rates in paediatric achalasia. Because of the low morbidity associated with balloon dilatation, the procedure should be considered as first line treatment of this condition. If the lower oesophageal sphincter is stretched insufficiently using a single balloon, tandem balloon dilatation should be utilised.

Catheterization↗
PubMed1996

Three year follow-up of a case of giant cell arteritis presenting with a chronic cough and upper limb ischaemic symptoms.

A case of giant cell arteritis presenting in an atypical fashion with respiratory and upper limb ischaemic symptoms is described. The subclavian and axillary arterial involvement is demonstrated in this case, and followed up with repeated angiographic examinations over the next 3 yr. Despite resolution of all symptoms and return of pulses and a recordable blood pressure in the ischaemic upper limb, there was no angiographic evidence of resolution of the axillary artery stenoses.

Arm↗
PubMed1996

Small gauge gelfoam plug liver biopsy in high risk patients: safety and diagnostic value.

The performance of a percutaneous core biopsy of the liver may be contraindicated in patients at higher risk of haemorrhage. In this clinical setting, gelfoam plug embolization of the needle track has been proposed to minimize haemorrhagic complications of biopsy. In the present study, gelfoam plug liver biopsy was performed in 51 consecutive patients at increased risk of haemorrhage. An 18 gauge spring-loaded disposable cutting needle was used through a 4 French sheath. The biopsy track was embolized by three to four gelfoam pledgets. In every patients, the cores of hepatic tissue were adequate for histopathological diagnosis. There were no fatalities and no serious complications. Gelfoam plug liver biopsy using this needle and sheath in combination appears to be a safe procedure and produces diagnostic cores for histological analysis. This method represents an alternative to transjugular liver biopsy and is technically more straight-forward to perform.

Adolescent↗
PubMed1995

Sporting 'groin strains': not always muscular!

A gluteal artery pseudoaneurysm presenting as a 'groin strain' following minor trauma is reported. Diagnosis was made by CT scan and arteriography. Treatment was with superselective catheterization and microcoil embolization.

Adolescent↗
PubMed1994

Incidence of the empty delta sign in computed tomography in the paediatric age group.

The computed tomographic (CT) appearances of dural sinus thrombosis are variable, but include visualization of thrombus within the sinus on post-contrast images (the 'empty triangle' or 'empty delta' sign). This review of 104 consecutive examinations was undertaken to assess the incidence of the empty delta sign in a paediatric group undergoing CT examinations. The number of examinations in which a sagittal sinus filling defect was seen in three or more images, was unexpectedly high. An overall incidence of 18% was noted. Defects due to bone artifact and defects seen on only one or two slices were excluded. The age distribution of abnormal scans was markedly skewed towards young infants. Nine of 27 examinations (33%) in infants less than 1 month of age, were positive for filling defects, compared with six of 21 (29%) aged between 1 and 12 months, and four of 56 (7%) aged over 1 year. This review suggests that the finding of a filling defect or empty delta sign in the sagittal sinus is not pathognomonic for sinus thrombosis that results in clinically apparent manifestations. Second, a filling defect apparent on CT may resolve spontaneously. The incidence of non-occlusive sinus thrombosis may be significantly higher than previously recognized, particularly in young infants where predisposing conditions including dehydration, infection or prematurity coexist. Previous studies have indicated that the sensitivity of the empty delta sign is approximately 30%. This study implies that either the empty sign has limited specificity in the paediatric population, or that unrecognized non-occlusive sinus thrombosis is much more frequent than previously described.

Adolescent↗
PubMed1994

Colour duplex ultrasound: a screening modality for femoropopliteal disease in patients with intermittent claudication.

In patients presenting with intermittent claudication, Colour Duplex Ultrasound (CDU) examination of the femoro-popliteal segment has been proposed as a screening modality. Those patients with atheromatous lesions suitable for percutaneous transluminal angioplasty (PTA) could proceed to diagnostic angiography. Patients with long segment occlusive disease demonstrated by CDU, who were not considered suitable candidates for surgery, would not require angiographic examination. This prospective study was performed on 46 limbs in 25 consecutive patients who presented for investigation of claudication. There was close correlation between the two methods in the demonstration of high-grade stenoses and occluded segments. Using angiography as the 'gold standard' this study indicated a diagnostic accuracy for CDU of 93% with a sensitivity of 89% and a specificity of 95%. Angiography tended to show longer occluded segments than CDU. Colour Duplex Ultrasound shows promise as a screening investigation in patients with intermittent claudication to detect lesions that may be suitable for PTA.

Aged↗
PubMed1994

Posttraumatic priapism in a 7-year-old boy.

Priapism in childhood is most commonly a low-flow state due to sickle cell anemia. A high-flow priapism was seen in a 7-year-old boy following a straddle-injury-induced arteriocavernosal fistula. Penile aspiration, intracorporeal alpha-agonist injection and unilateral arterial embolization failed to resolve the priapism which eventually settled following a cavernosaphenous shunt.

Child↗
PubMed1993

Percutaneous cystogastrostomy for treatment of pancreatic pseudocysts.

Cystogastrostomy or cystojejunostomy at open operation has been the usual treatment for symptomatic pancreatic pseudocyst. The aim of this study was to assess prospectively the results of percutaneous cystogastrostomy (PCG) for the treatment of symptomatic pseudocysts. The technique of PCG comprised initially of drainage of the pseudocyst with a 10 Fr percutaneous, transgastric catheter. This initial drainage catheter had two components; the first, between the pseudocyst and the stomach, drained the pseudocyst and the second, between the stomach and exterior, acted as a percutaneous gastrostomy. The initial drain was left in situ for 14 days, at which time it was exchanged percutaneously for the definitive PCG; a double ended Mallecot type catheter that drained between the pseudocyst and the stomach. The latter catheter was left in situ until there was no residual pseudocyst demonstrated on computerized tomography scan and was removed endoscopically. Eleven patients with large (> 6 cm), symptomatic pseudocysts have been treated with PCG. All patients were treated successfully without the need for surgical intervention. The median time to radiological resolution was 24 days. There were four episodes of sepsis, two related to central venous line infections nad two related to catheter blockage. Percutaneous, cystogastrostomy blockage was managed by either replacing the initial drain or inserting a second catheter. The median follow up after successful treatment was 9 months (range 2-17). There were no symptomatic recurrences and one small (2 cm) asymptomatic recurrent pseudocyst. This preliminary experience with PCG demonstrates the efficacy of this procedure for treating symptomatic pancreatic pseudocysts.

Adult↗
PubMed1992

Radiological assessment of duodenal calibre in congenital duodenal obstruction.

A review of barium meal studies in 32 cases of congenital intrinsic duodenal obstruction (CDO) from the Adelaide Children's Hospital was performed to assess and measure pre and post operative duodenal dilatation. Comparisons were made with a group of 153 normal barium studies from the same Hospital with a view to quantifying normal and abnormal proximal duodenal calibre. Duodenal size was expressed as a ratio D1/L1, (diameter of 1st part of duodenum/height of first lumbar vertebra). In this study a normal range of duodenal diameter was found to be 0.90 to 1.62 (+/- 2 SD from mean), with a mean of 1.26. The CDO patients recorded a range of postoperative ratios on first follow-up barium studies of between 1.2 and 4.5 with a mean of 2.28. Where serial studies had been performed, duodenal diameter was found to show some decrease in size postoperatively. In patients who underwent surgery for membrane obstruction there was a trend towards normalisation of duodenal diameter over time, compared with the atresia group. However, this difference did not reach statistical significance.

Barium Sulfate↗
PubMed1992

Percutaneous drainage of a thigh haematoma: case report of an unusual radiographic appearance.

We present a case of fat necrosis in the thigh of a ten year old girl, resulting in unusual multiple, ovoid filling defects seen in the residual cavity following drainage of a subcutaneous haematoma. No similar cases have been found on review of the literature. The appearance is described to aid diagnosis at the time of initial cavity drainage, avoiding the need for further investigation.

Child↗