Native pulmonary valve endocarditis requiring pulmonary valve replacement in adulthood: a case series

Native pulmonary valve endocarditis is a rare phenomenon as native valve endocarditis tends to typically affect the left sided heart valves. However, the right-sided heart valves can be affected in patients with a history of intravenous drug use, whereby the tricuspid valve is most commonly affected. We present two cases who were diagnosed with native pulmonary valve endocarditis in the absence of congenital heart disease. In the first case, the native pulmonary valve endocarditis was probably a derivative of compounding factors of an enlarged underlying pulmonary artery and staphylococcal bacteraemia. In the second case, a common causal organism of native valve endocarditis following dental treatment and the resultant echocardiography findings was of significant interest. In summary, native pulmonary valve endocarditis is relatively rare complication in the adult population, especially in the absence of congenital heart disease.

Off-pump external pericardial patch repair for post-infarct left ventricular free wall rupture: a case series

We describe an off-pump surgical approach to this challenging condition supported by our results from a case series, which would add to existing literature in the management of this life-threatening complication. We identified seven patients who underwent surgical intervention for left ventricular (LV) free wall rupture at our institution. They were all diagnosed to have cardiac tamponade secondary to free wall rupture of the LV in the presence of acute myocardial infarction. The surgical technique comprised of utilizing an external pericardial patch which was secured using surgical biological glues (fibrin-based sealants or gelatin hydrogels). The 30-day mortality, 1-year survival and 2-year survival were 57, 42 and 42%, respectively. Advanced age, female gender and use of cardiopulmonary bypass were characteristics that were not significantly associated with survival. We advocate the use of an off-pump external pericardial patch repair strategy as a ‘bridge to recovery’ in this extremely high-risk group of patients.

P1247 Bilateral endogenous endophthalmitis as the initial presentation of hacek prosthetic valve infective endocarditis

Summary

A 75 year old lady with a prosthetic aortic valve (St Jude mechanical AVR) presented to ophthalmology with a one month history of black spots in the vision of her left eye with a further episode in her right eye two weeks later, leading to a diagnosis of bilateral endogenous endopthalmitis and was admitted to hospital. There was no history of trauma and the chest and abdominal examination was normal. The erythrocyte sedimentation rate (40) and C reactive protein (45.8) were elevated. She had several sets of blood cultures, which were positive for Aggregatibacter actinomycetemcomitans, a HACEK organism and was started on empirical Ceftriaxone. The transthoracic echocardiography was normal. However, the suspicion of Infective Endocarditis (IE) was high, therefore a transoesophageal echocardiography was performed and showed an aortic root abscess (Image 1). An urgent computerised aortogram was performed. Following a planned two week period of intravenous antibiotics the patient was taken to theatre to have a redo AV valve replacement and root repair. Following a prolonged period on intensive care and a six week course of pathogen directed antibiotic therapy she was then fit enough to be discharged.

Conclusion

We present the first case in the literature of a HACEK Prosthetic Valve endocarditis presenting with bilateral endogenous endophthalmitis.

Abstract P1247 Figure. TOE image of Absess

Progress in Arabidopsis genome sequencing and functional genomics

Arabidopsis thaliana has a relatively small genome of approximately 130 Mb containing about 10% repetitive DNA. Genome sequencing studies reveal a gene-rich genome, predicted to contain approximately 25000 genes spaced on average every 4.5 kb. Between 10 to 20% of the predicted genes occur as clusters of related genes, indicating that local sequence duplication and subsequent divergence generates a significant proportion of gene families. In addition to gene families, repetitive sequences comprise individual and small clusters of two to three retroelements and other classes of smaller repeats. The clustering of highly repetitive elements is a striking feature of the A. thaliana genome emerging from sequence and other analyses.

Sequence and analysis of chromosome 4 of the plant Arabidopsis thaliana

The higher plant Arabidopsis thaliana (Arabidopsis) is an important model for identifying plant genes and determining their function. To assist biological investigations and to define chromosome structure, a coordinated effort to sequence the Arabidopsis genome was initiated in late 1996. Here we report one of the first milestones of this project, the sequence of chromosome 4. Analysis of 17.38 megabases of unique sequence, representing about 17% of the genome, reveals 3,744 protein coding genes, 81 transfer RNAs and numerous repeat elements. Heterochromatic regions surrounding the putative centromere, which has not yet been completely sequenced, are characterized by an increased frequency of a variety of repeats, new repeats, reduced recombination, lowered gene density and lowered gene expression. Roughly 60% of the predicted protein-coding genes have been functionally characterized on the basis of their homology to known genes. Many genes encode predicted proteins that are homologous to human and Caenorhabditis elegans proteins.

Mebeverine decreases mass movements and stool frequency in lactulose-induced diarrhoea

BACKGROUND

In spite of its frequent use in the treatment of irritable bowel disease little is known about mebeverine's mode of action in man.

AIM

To examine mebeverine's effect on transit though the gut during lactulose-induced diarrhoea.

METHODS

Nine healthy volunteers undertook a two-way randomized crossover study. Diarrhoea was induced using lactulose pre-treatment (20 m t.d.s., 4 days) and subjects received either mebeverine (135 mg t.d.s.) or no treatment. Transit of two enteric-coated capsules containing radiolabelled 8.4 mm tablets and 180-250 microM ion exchange resin were followed using gamma scintigraphy. Stool frequency and symptoms were assessed by diary cards.

RESULTS

Mebeverine reduced mean daily stool frequency associated with lactulose ingestion from a median of 2.25 (interquartile range (IQR) 1.75-2.75) to 1.5 (IQR 1.25-2.25) movements. Mebeverine significantly reduced the number of mass movements observed in the colon during the 11 h of the study from 2 (2-2) to 1 (1-2), and the number of retrograde movements from 1 (0-2) to 0 (0-0) (P < 0.05). Mebeverine did not significantly alter the gastric emptying rate of the intact capsule (2.9 (1.9-3.2) to 2.8 (2.6-4.0) h) however it induced a small but significant acceleration in small intestinal transit of the capsule (1.6 (0.8-2.0) h to 1.0 (0.52-1.32) h, P=0.02).

CONCLUSION

Mebeverine reduces the diarrhoeal effect of lactulose by decreasing the mass movements induced in the ascending colon. This effect may contribute to its clinical effect in irritable bowel syndrome.

Analysis of 1.9 Mb of contiguous sequence from chromosome 4 of Arabidopsis thaliana

The plant Arabidopsis thaliana (Arabidopsis) has become an important model species for the study of many aspects of plant biology. The relatively small size of the nuclear genome and the availability of extensive physical maps of the five chromosomes provide a feasible basis for initiating sequencing of the five chromosomes. The YAC (yeast artificial chromosome)-based physical map of chromosome 4 was used to construct a sequence-ready map of cosmid and BAC (bacterial artificial chromosome) clones covering a 1.9-megabase (Mb) contiguous region, and the sequence of this region is reported here. Analysis of the sequence revealed an average gene density of one gene every 4.8 kilobases (kb), and 54% of the predicted genes had significant similarity to known genes. Other interesting features were found, such as the sequence of a disease-resistance gene locus, the distribution of retroelements, the frequent occurrence of clustered gene families, and the sequence of several classes of genes not previously encountered in plants.

Spontaneous pneumomediastinum

Images

Surgical presentations of Ehlers-Danlos syndrome type IV. A case report

The case of a 28 year old man with Ehlers-Danlos syndrome (EDS) type IV is presented. He had the typical facies of this disorder, thin skin with atrophic scars and bruised easily. He suffered with congenital clubbed feet, heavy blood loss and poor wound healing following a traumatic compound fracture of the right leg, recurrent spontaneous pneumothoraces for which a pleurectomy was performed, two episodes of vascular rupture following minor trauma, one managed conservatively and the other surgically, and one episode of massive spontaneous vascular rupture which was fatal. In this report we highlight the surgical nature of the presenting complications of EDS type IV and demonstrate the hazards of surgical management. We conclude that, when possible, conservative management is preferable.

Endothelial function of human gastroepiploic artery. Implications for its use as a bypass graft

The human gastroepiploic artery has been used as a coronary artery bypass conduit in a limited number of clinical studies. It has been postulated that the capacity of the endothelium to release vasoactive substances may contribute to differing patency rates observed in established bypass grafts. We have now examined endothelial function in the human gastroepiploic artery. Endothelium-dependent relaxations to substance P were observed. A maximum relaxation of 83.25% +/- 8.2% (mean +/- standard error) was attenuated to 48.5% +/- 16.4% in the presence of L-NG-monomethyl-arginine, a specific inhibitor of endogenous nitric oxide synthesis. Removal of the endothelium abolished the relaxations. With a specific radioimmunoassay, concomitant changes in levels of cyclic guanosine 3',5'-monophosphate, the second messenger that elicits smooth muscle relaxation after release of the endothelium-derived relaxing factor, were measured. It was found that the gastroepiploic artery had significantly higher resting and stimulated levels of cyclic guanosine 3',5'-monophosphate than either the internal mammary artery or the saphenous vein. In the presence of the cyclooxygenase inhibitor indomethacin, and indomethacin plus L-NG-monomethylanginine, the maximum relaxation was decreased to 70% +/- 9.5% and 59% +/- 10.8%, respectively. Our data demonstrate that endothelium-derived relaxing factor and prostacyclin may exhibit synergy in the control of vascular tone in this vessel. It is concluded that the endothelium of the gastroepiploic artery has a strong capacity to secrete vasodilators and inhibitors of platelet activity. This could have important influence on long-term patency.