Secundum atrial septal defect repair: long-term surgical outcome and the problem of late mitral regurgitation.

This study examines the clinical and surgical outcome of a group of 55 patients (mean age 33 years) with secundum atrial septal defect who underwent surgical repair of this defect between 1981 and 1990. A group of 25 of these patients underwent late echocardiographic follow-up. Fifty-two patients underwent repair by direct suturing and three by patch closure. Surgical mortality was nil. There was one late death of a 58 year old who died from cardiac failure 4 years after surgery. Late postoperative morbidity consisted of two patients; one, age 63 at the time of surgery, required mitral and tricuspid valve replacement 6 years later and one, age 77 at surgery, developed cardiac failure 3 years later. Atrial fibrillation persisted in the six patients who had the rhythm before surgery and developed postoperatively in two patients aged 54 and 58. Two patients aged 49 and 57 developed immediate postoperative sinus node dysfunction requiring permanent pacing. The mean age at surgery of those six patients who suffered cardiac morbidity was 60 years. The patients with preoperative angiographic evidence of mitral valve prolapse were significantly older (P < 0.001) and had higher mean pulmonary artery pressures (P < 0.001) than patients with normal valves. There was no significant relationship between shunt size and mitral valve prolapse. Echocardiographic follow-up showed persistent mitral valve prolapse in all nine patients who developed the condition preoperatively. Five patients developed mitral valve prolapse with mitral regurgitation postoperatively, one of whom needed subsequent mitral and tricuspid valve replacement. These five patient were on average older (mean age 54) but the group was too small to prove significance. The follow-up data illustrate the current low mortality and morbidity associated with surgical closure of atrial septal defects. Late postoperative echocardiography had revealed not only that mitral valve prolapse persists in those patients who developed the condition pre-operatively but that new cases of mitral valve prolapse with mitral regurgitation can occur after atrial septal defect closure.     

The interrelation between the monophasic action potential duration, cycle length and ischaemia in the human left ventricle.

Steady state monophasic action potentials were recorded from a single site in the left ventricular endocardium during incremental atrial pacing to the point of angina in 25 patients. Ischaemic areas of the left ventricle were documented using a perfusion marker (99mTc-MIBI) simultaneously with the action potential recording procedure. Recordings were obtained from an ischaemic area in 13 patients and from a non-ischaemic area in 12. A linear correlation between action potential duration and cycle length changes was demonstrated for both ischaemic and non-ischaemic zone recordings between cycle length changes of 750 and 428 ms. Ischaemia induced a shortening of the action potential duration significantly greater than that produced by cycle length changes (P less than 0.0001). Mean action potential duration shortening corrected for 100 ms change in cycle length for ischaemic zone recordings was 31.4 +/- 4.2 (SD) compared to 23.3 +/- 3.1 ms for non-ischaemic zone recordings. A range of values of action potential duration shortening in unit time was analysed for sensitivity and specificity for the detection of ischaemia. A value of 26.5 ms per 100 ms change in cycle length provided the optimum compromise with 88% sensitivity and specificity. Our data provide a means of employing the monophasic action potential duration to quantify early localized ischaemia in the presence of an alteration in cycle length.     

Pregnancy rates after conservative treatment for borderline ovarian tumours: A systematic review

Borderline ovarian tumours account for 10–15% of all ovarian cancers, and there have been numerous studies indicating their excellent long-term prognosis. As this disease commonly affects younger women, the issue of fertility-preserving surgery is increasingly important.     

Isolation of a clone partially encoding hill kangaroo X-linked hypoxanthine phosphoribosyltransferase: Sex differences in methylation in the body of the gene

An X-linked clone encoding exons 4–9 of the hypoxanthine phosphoribosyltransferase (HPRT) gene was isolated from a kangaroo (Macropus robustus: Marsupialia) EMBL4 genomic library. Sequence similarity between the kangaroo and eutherian HPRT coding sequences was high; however, intron sizes varied significantly between the kangaroo and other eutherian species. HpaII and HhaI sites in the body of the gene were generally hypermethylated in vivo on the active, relative to the inactive X, with sites within intron 3 showing essentially complete correspondence of activity with methylation and inactivity with unmethylation. At approximately 5 kb downstream from the gene, a switch to unmethylation of active X-linked sites occurred. This switch occurred within a cluster of HpaII and HhaI sites that may represent a CG island associated with a subsequent gene.The sequence data in this paper have been submitted to the Genbank Data library under the accession numbers M77 683; M77 684; M77 685; M77 686.     

Stress induced right ventricular dysfunction: An indication of reversible right ventricular ischaemia

Stress induced changes in left ventricular ejection fraction are widely used in the detection and assessment of coronary artery disease. This study demonstrates that right ventricular dysfunction may also occur, and assesses its significance in terms of coronary artery anatomy. This study involved 14 normal subjects and 26 with coronary artery disease investigated by equilibrium radionuclide ventriculography, at rest and during maximal dynamic exercise. Mean normal resting right ventricular ejection fraction (RVEF) was 0.40 (SD 0.118), and all normal subjects increased RVEF with stress (mean RVEF+0.13 SD 0.099). Mean RVEF in the subjects with coronary artery disease was significantly lower at 0.00 (SD 0.080), but there was overlap between the two groups. The largest falls in RVEF were seen if the right coronary artery was occluded without retrograde filling. In this subgroup with the most severely compromised right ventricular perfusion (nine subjects), RVEF always fell with stress, and mean RVEF was-0.08 (SD 0.050). There was no significant correlation between LVEF and RVEF, implying that the right ventricular dysfunction was due to right ventricular ischaemia, rather than secondary to left ventricular dysfunction. Stress induced right ventricular ischaemia can therefore be detected readily by radionuclide ventriculography.     

Expansion of airway basal epithelial cells from primary human non‐small cell lung cancer tumors

Pre‐clinical non‐small cell lung cancer (NSCLC) models are poorly representative of the considerable inter‐ and intra‐tumor heterogeneity of the disease in patients. Primary cell‐based in vitro models of NSCLC are therefore desirable for novel therapy development and personalized cancer medicine. Methods have been described to generate rapidly proliferating epithelial cell cultures from multiple human epithelia using 3T3‐J2 feeder cell culture in the presence of Y‐27632, a RHO‐associated protein kinase (ROCK) inhibitor, in what are known as “conditional reprograming conditions” (CRC) or 3T3 + Y. In some cancer studies, variations of this methodology have allowed primary tumor cell expansion across a number of cancer types but other studies have demonstrated the preferential expansion of normal epithelial cells from tumors in such conditions. Here, we report our experience regarding the derivation of primary NSCLC cell cultures from 12 lung adenocarcinoma patients enrolled in the Tracking Cancer Evolution through Therapy (TRACERx) clinical study and discuss these in the context of improving the success rate for in vitro cultivation of cells from NSCLC tumors.     

Bone mineral density in institutionalised patients with refractory epilepsy.

Bone mineral density (BMD) and content (BMC) were measured in 208 institutionalised patients with refractory epilepsy. BMD was in the osteoporotic range in 43% of males and 21% of females. BMC was reduced only in male patients. Apart from age and gender, no other factor or specific AED was particularly associated with reduced BMD or BMC. This study indicates the magnitude of the problem of bone disease in refractory epilepsy, in particular affecting young and male patients with chronic epilepsy.     

Propionibacterium acnes causing an aortic root abscess

A case of endocarditis caused by Propionibacterium acnes associated with an aortic root abscess is presented. This supports the current opinion that aortic root abscesses are not necessarily associated with microorganisms of high virulence.     

Effect of intermittent left anterior hemiblock on left ventricular function.

Studies of left ventricular function were performed during intermittent left anterior hemiblock, Max dP/dt and Vmax fell during left anterior hemiblock, with a rise in left ventricular end-diastolic pressure compared with a normally conducted beat.