Current state of interventional cardiology in congenital heart disease.

Congenital interventional cardiology seeks to provide alternative percutaneous solutions to congenital cardiac problems in preference to more traditional surgical approaches. Simpler procedures have been refined and are now achievable in smaller children and infants. More complex procedures are increasingly recognised as superior to surgical alternatives, though most patients with complex disease inevitably undergo combinations of interventional, surgical and joint or hybrid procedures. This review seeks to highlight recent advances in these techniques of most interest to the readership of this journal.

The development of genome-wide association studies and their application to complex diseases, including lupus.

In this review, we explain the motivation for carrying out genome-wide association studies (GWAS), contrasting the achievements of linkage-based experiments for Mendelian traits with the difficulties found when applying that type of experiment to complex diseases. We explain the technical and organizational developments that were required to make GWAS feasible, as well as some of the theoretical concerns that were raised during the design of these studies. We describe the impressive achievements of GWAS in lupus, and compare them with the experiences in three other genetically complex disorders: rheumatoid arthritis, type 1 diabetes and coronary heart disease. GWAS have been successful in identifying many new susceptibility loci for these four diseases, and have provided the motivation for novel immunological work. We conclude by describing preliminary steps that have been taken towards translating the results of GWAS into improvements in patient care, explaining some of the difficulties involved, as well as successes that have already been achieved.

Transcatheter and endovascular stent graft management of coarctation-related pseudoaneurysms.

OBJECTIVE: Surgical correction of congenital aortic coarctation can lead to a number of important problems including late pseudoaneurysm formation. Redo surgery has a significant risk. Endovascular stent graft repair is increasingly used but there are limited data regarding this indication. We describe the experience of two UK congenital referral centres. DESIGN: Retrospective analysis of patients treated with endovascular aortic stent grafting for late pseudoaneurysms. SETTING: Two UK congenital heart centres, Bristol Heart Institute and Leeds General Infirmary. PATIENTS: 17 patients were treated 2006-2012. This represents all patients treated with this technique. MAIN OUTCOME MEASURES: Procedural and postprocedure success and complications. RESULTS: The average time from index repair to endovascular repair of pseudoaneurysm was 24.6 years. The majority (70.6%) had patch aortoplasty as the original surgical procedure and 41.2% were not under follow-up or discharged. Stent grafting procedural success rate was 100%. Median hospital stay postprocedure was 3 days. There was no procedural mortality or immediate complication. There were four minor early and three minor late complications. Imaging follow-up was available for an average of 31.6 months (range 6-65 months). All patients have demonstrated positive remodelling of the pseudoaneurysm with no incidence of continued expansion or stent graft failure up to 5 years following implant. CONCLUSIONS: Endovascular stent graft treatment of pseudoaneurysms show promising results in a population who have a high risk of surgical re-intervention. Complication rates appear to be low and recovery is quick. Longer-term data remain essential to scrutinise stent graft performance in this situation.

Some chronic obstructive pulmonary disease will originate in neonatal intensive care units.

Chronic lung disease is the most common adverse outcome in survivors of prematurity. These infants experience frequent hospitalisation because of respiratory-related illness in their first year, as well as persistent cough, wheeze and oxygen dependence. Although the severity of respiratory illness decreases and supplemental oxygen is needed less as their lungs mature, childhood is still complicated by persistent wheeze, cough and reduced exercise tolerance in comparison with their peers. Although there is little longitudinal follow-up data beyond adolescence, imaging studies suggest that these infants are highly likely to suffer with respiratory problems akin to chronic obstructive pulmonary disease in later adulthood. The nature of their long-term respiratory problems, the impact of cigarette smoking and the effect on life expectancy are all unanswered questions that need addressing as these infants grow up.

Students conducting consultations in general practice and the acceptability to patients.

OBJECTIVES: The General Medical Council has recommended that medical students should gain more experience in general practice. The study set out to determine patients' reactions to consultations conducted by a medical student alone prior to seeing their GP. DESIGN: A random sample of patients attending general practice surgeries in the Oxford area completed a questionnaire following consultation with a medical student. SETTING: Six general practice teaching surgeries. SUBJECTS: Fifth-year medical students. RESULTS: Of 130 responders 98% experienced no disadvantage in seeing the student; 35% considered that there were advantages in seeing the student; 98% said that they would be prepared to consult with a student again; 85% expressed no concerns about the gender of the student. CONCLUSIONS: The results of this study are very reassuring concerning the acceptability to patients of consulting with medical students and are more favourable than those reported for studies of students being present in consultations by GPs.

Expression of IGFBP-1 in normal and cirrhotic human livers.

Cirrhosis of the liver, a condition characterised by hepatocyte regeneration, is also associated with elevated insulin levels and insulin resistance. In animal models hepatic regeneration is associated with increased IGFBP-1 gene expression. Insulin is known to be an inhibitor of IGFBP-1 gene expression and circulating insulin levels in man demonstrate a negative correlation with IGFBP-1 levels. To further our understanding of the regulation of IGFBP-1 in cirrhosis we have studied steady state levels of IGFBP-1 mRNA in human liver from three groups of patients: Group 1, tissue obtained at the time of harvesting donor liver for orthotopic liver transplantation (n = 4); group 2, patients undergoing major liver resection with no histological evidence of chronic liver disease (n = 4); and group 3, patients undergoing orthotopic transplantation for chronic liver failure (n = 9). Simultaneous samples of serum were taken at the time of surgery in some patients and in these patients IGFBP-1 mRNA levels were related to circulating levels of IGFBP-1 and insulin. IGFBP-1 mRNA was detectable in all the human liver samples with the greatest levels seen from the normal livers of group 2 patients. Insulin levels were elevated in the cirrhotic group 3 patients compared to a normal range as were IGFBP-1 levels. There was no relationship between circulating levels of IGFBP-1 and IGFBP-1 gene expression. In conclusion, IGFBP-1 mRNA is present in human adult liver at the time of surgery and also in cirrhotic liver despite high levels of insulin suggesting that there are factors other than insulin regulating IGFBP-1 gene expression.

Histochemical detection of binding sites for human growth hormone using biotinylated ligand.

Recombinant human growth hormone was covalently linked to biotin via a six-carbon spacer arm. Biotinylation was confirmed by electrophoresis and mass spectrometry showed that approximately 50% of the hormone was monobiotinylated. The modified growth hormone (GH) was shown to bind to the GH receptor of IM9 human lymphoid cells with an affinity of 0.55 x 10(9) M-1. Bioactivity of biotinylated GH measured in the Nb2 bioassay was 53.9% that of unlabeled GH. GH binding sites on human IM9 cells were visualized histochemically with the biotinylated hormone, a technique that provides a means of identifying receptors for GH on target cells in vitro.

A double-staining technique for detection of growth hormone and insulin-like growth factor-I binding to rat tibial epiphyseal chondrocytes.

In the present study a double-staining technique was developed to investigate simultaneous GH and insulin-like growth factor-I (IGF-I) binding to chondrocytes in a monolayer cell culture. Rat tibial epiphyseal chondrocytes were isolated by enzymatic digestion and cultured in monolayer. GH and IGF-I were labelled with biotin. The affinity of the biotin-labelled ligands was compared with unlabelled ligands in a radioreceptor assay. To study the distribution of GH and IGF-I binding in the monolayer, chondrocytes were incubated with biotinylated ligands with or without an excess of unlabelled ligands, followed by incubation with Vectastain ABC complex, which was then reacted with diaminobenzidine (DAB). Double staining was accomplished by carrying out the first reaction with DAB in the presence of nickel ammonium sulphate to give a black precipitate, followed by incubation with the second ligand, then ABC complex and finally DAB in the absence of nickel ammonium sulphate to give a brown stain. The presence of type-II collagen was demonstrated by immunohistochemistry and used as a marker for differentiated chondrocytes. Biotin-labelled GH and biotin-labelled IGF-I exhibited dose-dependent displacements of 125I-labelled GH and 125I-labelled IGF-I respectively from the chondrocytes in a radioreceptor assay. The displacement curves were identical to those of unlabelled ligands indicating that the affinity was unaltered. Binding of biotinylated GH to cells was seen throughout the culture in regions where there was little or no type-II collagen staining. IGF-I binding was predominantly localized to cells at high density; areas which also showed a high degree of staining for type-II collagen.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired growth hormone resistance in patients with hypercatabolism.

Sepsis, surgery and critical illness are associated with an increased catabolic rate, which if prolonged delays recovery and increases morbidity and mortality. There is evidence that changes in the GH/IGF-I axis are permissive to protein catabolism. Critically ill, septic patients have high basal levels of GH, low levels of IGF-I and its carrier binding protein IGFBP-3, high levels of an inhibitory binding protein, IGFBP-I, and increased serum protease activity which reduces the affinity of IGFBP-3 for IGF-I. Overall there is a reduction in the indirect IGF-I-mediated anabolic actions of GH and an increase in the direct catabolic actions of GH. These physiological changes may be adaptive when a sick patient is fasting; however, the availability of modern intensive care means that these changes are no longer an advantage. GH and IGF-I, in pharmacological doses, promote positive nitrogen balance, in both animal models and man. Preliminary studies with IGF-I in postsurgical patients suggest that it may provide a practical therapy. Future studies need to focus on outcome measures in relation to the use of GH and IGF-I as anabolic therapies.

Expression of functional growth hormone receptors in human granulosa cells.

Both clinical and experimental evidence suggest that growth hormone may be of importance for ovarian function. The present study investigated whether growth hormone receptors are expressed in human granulosa cells. Granulosa cells were isolated either from natural cycles or from stimulated cycles in the course of in-vitro fertilization. Total RNA hybridized with a 32P-labelled rat growth hormone receptor cRNA probe revealed one major transcript with an estimated size of 4.5 kb and one minor transcript with an estimated size of 1.3 kb. Biotinylated growth hormone was used to analyse growth hormone binding. Competitive growth hormone binding was detected in freshly isolated granulosa cells, as well as in cultured cells. Growth hormone augmented basal and/or follicle stimulating hormone-stimulated steroidogenesis in granulosa cells obtained from patients with natural cycles, but the response to growth hormone stimulation showed considerable variation. We conclude that functional growth hormone receptors are present in human granulosa cells and that growth hormone, therefore, may have an important role in ovarian function.

Effects of tri-iodothyronine and insulin-like growth factor-I (IGF-I) on alkaline phosphatase activity, [3H]thymidine incorporation and IGF-I receptor mRNA in cultured rat epiphyseal chondrocytes.

The effects of tri-iodothyronine (T3) and insulin-like growth factor-I (IGF-I) on [3H]thymidine incorporation, alkaline phosphatase (ALP) activity and IGF-I receptor mRNA levels were studied in rat epiphyseal chondrocytes cultured in monolayer. Chondrocytes from enzymatically digested rat tibia epiphyseal growth plates were seeded in monolayer culture and precultured for 7-14 days in Ham's F-12 medium supplemented with 10% (v/v) newborn calf serum and 1% (v/v) of a serum substitute. After preculture the medium was changed to Ham's F-12 medium containing 1% (v/v) serum from hypophysectomized rats, and the effects of T3 and/or IGF-I on DNA synthesis ([3H]thymidine incorporation), ALP activity (a late marker of differentiated epiphyseal chondrocytes) and IGF-I receptor mRNA levels were studied. ALP activity was increased by T3 in a dose-dependent manner with a maximal response at 10 micrograms T3/l (678 +/- 86% compared with control culture). The increase in ALP activity was accompanied by a concomitant decrease in [3H]thymidine incorporation (52 +/- 14% compared with control culture). Human GH (hGH; 50 micrograms/l) and IGF-I (25 micrograms/l) had no stimulatory effect on ALP activity. However IGF-I (10 micrograms/l) exerted an inhibition on the T3 (10 micrograms/l)-induced increase in ALP activity (64 +/- 9% compared with T3-treated culture). T3 (3 micrograms/l) inhibited the increase in [3H]thymidine incorporation caused by 25 micrograms IGF-I/l (51 +/- 13% compared with IGF-I-treated culture). Furthermore, IGF-I receptor mRNA levels were increased by 10 micrograms T3/l (137 +/- 4.2% compared with control culture) while no effect of hGH (50 micrograms/l) or IGF-I (25 micrograms/l) was demonstrated. Both T3 and IGF-I were shown to interact with epiphyseal chondrocytes and both substances seemed to affect cell proliferation and maturation and therefore longitudinal bone growth. Furthermore, the results indicated that IGF-I is important for proliferation of the cells while T3 initiates the terminal differentiation of epiphyseal chondrocytes.

Continuous passive motion device for hand rehabilitation.

Prototypes have been designed and manufactured for a lightweight portable device which continually moves all the joints of the hand passively through a range of motion. Inflatable bag modules in the palm of the hand are ganged together to create the required range of motion. A battery-operated air pump cycles compressed air to the modules. Initial clinical experience with patients who have flexion contractures caused by burns, trauma, and Dupuytren's contractures has shown the device to be well tolerated and effective.

The effects of ischaemia, lysophosphatidylcholine and palmitoylcarnitine on rat heart phospholipase A2 activity.

Phospholipase A2 activity was studied in the isolated rat heart following coronary artery ligation. In both the homogenate and mitochondrial fractions phospholipase A2 activity was significantly depressed at 20 min post ligation in the ischaemic region only. This is at a time of peak lysophospholipid concentration and severity of arrhythmias. No such depression of activity was seen in a crude sarcolemmal fraction, possibly due to washout of inhibitory factors during isolation. Lysophosphatidylcholine and palmitoylcarnitine, two amphiphiles known to accumulate during ischaemia, were both shown to be capable of inhibiting phospholipase A2. It is suggested that lysophospholipid and palmitoylcarnitine accumulation during ischaemia may contribute to the depression of phospholipase A2 activity seen and that the decreased metabolism of lysophospholipids may be of more importance in their accumulation than increased production by phospholipase A2.