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Biomedical subjects

J B Partridge

Publications and source records attributed to J B Partridge.

At least 19 recordsLinked to original sources

Differentiation and reversal of malignant changes in colon cancer through PPARgamma.

PPARgamma is a nuclear receptor that has a dominant regulatory role in differentiation of cells of the adipose lineage, and has recently been shown to be expressed in the colon. We show here that PPARgamma is expressed at high levels in both well- and poorly-differentiated adenocarcinomas, in normal colonic mucosa and in human colon cancer cell lines. Ligand activation of this receptor in colon cancer cells causes a considerable reduction in linear and clonogenic growth, increased expression of carcinoembryonic antigen and the reversal of many gene expression events specifically associated with colon cancer. Transplantable tumors derived from human colon cancer cells show a significant reduction of growth when mice are treated with troglitazone, a PPARgamma ligand. These results indicate that the growth and differentiation of colon cancer cells can be modulated through PPARgamma.

Adenocarcinoma↗

Asphyxia while swallowing solid food caused by bronchial compression: a variant of the pneumonectomy syndrome.

A 40 year old man presented with recurrent episodes of dyspnoea whilst swallowing solid food. He had undergone right pneumonectomy and thoracoplasty for recurrent pneumonias and empyema 23 years previously. Solid food boluses appeared to cause bronchial obstruction by compressing the surgically distorted left main bronchus. This is a new variant of the post pneumonectomy syndrome.

Adult↗

Computed tomographic assessment of coronary artery bypass grafts with fast dynamic scanning.

28 coronary grafts in 12 symptomatic patients were studied at the time of graft angiography at Prince Charles Hospital. The grafts were studied using the Toshiba 900S scanner with bolus injections of contrast agent into an anticubital vein. The assessment was carried out using fast incremental and continuous acquisition scanning with stepped reconstructions in the last 5 patients. Of the 27 grafts, 16 were shown at angiography to be patent and of good calibre. 14 of these were similarly assessed at CT. 11 were either diseased or blocked at angiography, and these were graded also as small, stenosed or blocked at CT. This early study would support previous reports that CT does offer a reliable method of diagnosing good patent grafts. The study also suggests that with conventional fast dynamic scanning some information regarding graft quality can be obtained.

Coronary Artery Bypass↗

Scimitar etcetera--the dysmorphic right lung.

'Dysmorphic lung' is introduced as a term to describe any complex congenital malformation which involves both abnormal vascular morphology and disordered growth of a whole lung. The major group within this definition is the scimitar syndrome, which we choose to mean a hypoplastic lung with anomalous venous drainage and various degrees of collateral arterial supply. Nine typical cases of scimitar are presented, with three closely related cases. Six other cases of dysmorphic lungs are also present. The relationships between the groups are discussed, and an effort is made to clarify the nomenclature used in this condition.

Humans↗

High leftward origin of the right coronary artery.

Minor variations in the position of the origin of the right coronary artery are not uncommon, but marked displacement is unusual. Three cases are presented in which the right coronary artery took origin from the middle third of the ascending aorta together with leftward displacement. Two cases were associated with valvar aortic stenosis. Selective catheterisation of this anomalous vessel can be difficult.

Aorta↗

Acetylsalicylic acid and dipyridamole improve the early patency of aorta-coronary bypass grafts. A double-blind, placebo-controlled, randomized trial.

A total of 125 patients undergoing aorta-coronary bypass grafting for disabling angina were randomized to receive either 330 mg of acetylsalicylic acid (aspirin) plus 75 mg of dipyridamole three times daily or a placebo for 6 months postoperatively. In addition, all patients were given warfarin for 3 months. Repeat angiography was performed at 6 months in 103 patients. In the treatment group 95 grafts were implanted in 48 patients, of which 87 were patent (91.6% patency rate). This figure compares with 88 grafts patent out of 118 implanted in 55 patients in the placebo group (74.6% patency rate) (p less than 0.01). We conclude that antiplatelet therapy improves the early patency of saphenous vein aorta-coronary bypass grafts.

Adult↗

Digital subtraction imaging in cardiac investigations.

The role of digital subtraction imaging (DSI) in the investigation of heart disease in patients of all ages, including neonates, was evaluated by the addition of a continuous fluoroscopy system to an existing, single-plane catheterisation laboratory. In some situations, DSI provided diagnostic images where conventional radiography could not and, in general, provided images of comparable quality to cineangiography. The total dose of contrast medium was usually less than that which would have been required for biplane cineangiography and the dose of radiation was always less. Digital subtraction imaging can make a significant contribution to the investigation of congenital heart disease and has some useful features in the study of acquired heart disease.

Adult↗

Digital subtraction angiography in infants and children with congenital heart disease.

Digital subtraction angiography was used as the sole imaging technique in 95 infants and children aged 13 hours to 16 years undergoing cardiac catheterisation for the investigation of congenital heart disease. Injections of diluted contrast medium were made selectively at central sites, and the images were obtained using continuous image intensification fluoroscopy at either 32.25 nC/kg/s (125 microR /s) or 129 nC/kg/s (500 microR /s). In all cases images adequate for diagnosis and management were obtained with appreciably less contrast medium and a lower radiation dose than in a comparable group of patients using conventional biplane cineangiography. Thus digital subtraction angiography is a viable alternative to biplane cineangiography for children with congenital heart disease.

Adolescent↗

Balloon occlusion angiography in critically ill neonates.

The use of balloon occlusion of a vessel during angiography is described in small ill babies. There were no complications associated with the technique, and angiographic visualisation of structures proximal to the balloon was improved especially in aortic arch anomalies.

Acute Disease↗

Vascular rings causing pulmonary collapse.

Mediastinal vascular anomalies (rings) have not previously been reported to cause pulmonary collapse. We record two cases where anomalous subclavian arteries were involved in the ring. This association can be predicted by considering the embryology of the subclavian arteries which arise from the lowest intersegmental arteries and migrate in a cephalad direction. An anomalous subclavian artery which did not complete this migration could cross the mediastinum at the carina. Investigation of a suspected vascular ring is firstly by a barium swallow which will show extrinsic compression of the oesophagus by the anomalous vessel. Arteriography demonstrates the exact anatomy of the vascular ring, but is a pre-surgical investigation undertaken in cases where the collapsed lung may re-expand following division of the vascular ring.

Aortography↗