Coronary artery spasm (CAS) simulating inferior ST elevation myocardial infarction (STEMI).

Coronary arteries vasospasm (CAS) is commonly seen in invasive cardiology laboratory during diagnostic catheterization or coronary intervention. Though the incidence of Printzmetal angina is uncommon, coronary vasospasm resulting in acute myocardial infarct is rare, especially if there is no significant atherosclerotic plaque within the coronary vasculature.

A rare coronary anatomy comprising dual (Type IV) left anterior descending arteries and an anomalous left circumflex artery from the right coronary artery.

We present the case of a rare coronary anomaly in a 64-year-old male who presented with exertional angina. The right coronary artery (RCA) was dominant, giving origin proximally to an anomalous left circumflex (LCX) artery and a left anterior descending (LAD) artery which supplied the conventional mid and distal LAD territory. The left main artery (LM) arose from the left coronary sinus and branched into a large first septal and an intermediate artery. There was associated non-critical atherosclerotic disease. We report this because of the rare division of the LAD area of supply by arteries from both coronary sinuses (dual LAD) with an anomalous LCX also arising from the proximal RCA. The clinical implications are discussed.

Durian induced hyperkalaemia.

Hyperkalaemia is a life threatening acute medical emergency. Patients with end stage renal failure are more prone to get hyperkalaemia as potassium is normally excreted via the kidneys. Therefore, patients with end stage renal failure should avoid food with high potassium contents. Bananas are well known to have high potassium content. However, the 'king of fruits' the durian, has higher potassium content compared to bananas. We describe a case of life threatening hyperkalaemia in a lady with end stage renal failure who ate durians prior to her presentation.

Feasibility and accuracy of 64-row MDCT coronary imaging from a centre with early experience: a review and comparison with established centres.

The accuracy of multi-detector computed tomographic (MDCI) coronary angiography (CTA) is dependant on image quality as well as the experience of the operator. Established centers have reported negative predictive values of over 95%. The aim of our study was to investigate the accuracy and feasibility of CTA for the assessment of haemodynamically significant coronary stenosis in a center with very early experience (<6 months) utilizing the improved spatial and temporal resolutions of the latest generation 64-row MDCI scanner. One hundred and twenty eight patients (93 male, 35 female; mean age 56.2 +/- 9.5 years) with suspected or known coronary artery disease underwent both CIA and conventional coronary angiographv (CCA). The sensitivity, specificity, positive (PPV) and negative (NPV) predictive values for stenoses > or =50% by CIA compared to CCA were 70%, 97%, 70% and 97% respectively. Evaluation of main and proximal segments in patients with good quality images (78% of patients) produced values of 94%, 95%, 74% and 99% respectively. The improved spatial and temporal resolutions of 64-row MJ) CT provided a high negative predictive value in assessing significant coronary artery stenosis even in a centre with very early experience. However, new centers embarking on CTA might not be able to reproduce the results reported by more experienced centers.

Solution structures of two CCHC zinc fingers from the FOG family protein U-shaped that mediate protein-protein interactions.

BACKGROUND: Zinc finger domains have traditionally been regarded as sequence-specific DNA binding motifs. However, recent evidence indicates that many zinc fingers mediate specific protein-protein interactions. For instance, several zinc fingers from FOG family proteins have been shown to interact with the N-terminal zinc finger of GATA-1. RESULTS: We have used NMR spectroscopy to determine the first structures of two FOG family zinc fingers that are involved in protein-protein interactions: fingers 1 and 9 from U-shaped. These fingers resemble classical TFIIIA-like zinc fingers, with the exception of an unusual extended portion of the polypeptide backbone prior to the fourth zinc ligand. [15N,(1)H]-HSQC titrations have been used to define the GATA binding surface of USH-F1, and comparison with other FOG family proteins indicates that the recognition mechanism is conserved across species. The surface of FOG-type fingers that interacts with GATA-1 overlaps substantially with the surface through which classical fingers typically recognize DNA. This suggests that these fingers could not contact both GATA and DNA simultaneously. In addition, results from NMR, gel filtration, and sedimentation equilibrium experiments suggest that the interactions are of moderate affinity. CONCLUSIONS: Our results demonstrate unequivocally that zinc fingers comprising the classical betabetaalpha fold are capable of mediating specific contacts between proteins. The existence of this alternative function has implications for the prediction of protein function from sequence data and for the evolution of protein function.

A class of zinc fingers involved in protein-protein interactions biophysical characterization of CCHC fingers from fog and U-shaped.

Zinc fingers (ZnFs) are extremely common protein domains. Several classes of ZnFs are distinguished by the nature and spacing of their zinc-coordinating residues. While the structure and function of some ZnFs are well characterized, many others have been identified only through their amino acid sequence. A number of proteins contain a conserved C-X2-C-X12-H-X1-5-C sequence, which is similar to the spacing observed for the 'classic' CCHH ZnFs. Although these domains have been implicated in protein-protein (and not protein-nucleic acid) interactions, nothing is known about their structure or function at a molecular level. Here, we address this problem through the expression and biophysical characterization of several CCHC-type zinc fingers from the erythroid transcription factor FOG and the related Drosophila protein U-shaped. Each of these domains does indeed fold in a zinc-dependent fashion, coordinating the metal in a tetrahedral manner through the sidechains of one histidine and three cysteine residues, and forming extremely thermostable structures. Analysis of CD spectra suggests an overall fold similar to that of the CCHH fingers, and indeed a point mutant of FOG-F1 in which the final cysteine residue is replaced by histidine remains capable of folding. However, the CCHC (as opposed to CCHH) motif is a prerequisite for GATA-1 binding activity, demonstrating that CCHC and CCHH topologies are not interchangeable. This demonstration that members of a structurally distinct subclass of genuine zinc finger domains are involved in the mediation of protein-protein interactions has implications for the prediction of protein function from nucleotide sequences.

Obstructive jaundice secondary to hepatocellular carcinoma.

This prospective study aimed to identify different groups of patients with the rare pathology of biliary obstruction caused by hepatocellular carcinoma (HCC). Patients were evaluated with blood tests, chest radiography, ultrasound of the liver and endoscopic retrograde cholangiopancreatography/percutaneous transhepatic cholangiography. Patients who were potentially operable were further assessed with selective hepatic angiography and computed tomography (CT). Of the 38 patients with obstructive jaundice secondary to HCC, the levels of obstruction were extrahepatic in 19 patients and intrahepatic in 19 patients. The clinical presentations and blood biochemistry were similar in these two groups of patients. "Curative' resection was significantly more common in extrahepatic obstruction (8/19) than in intrahepatic obstruction (0/19) (chi 2 with Yates correction P = 0.001). All non-resectable tumours, except in four patients with terminally ill disease, were palliated with stents. Survival in patients who had "curative' liver resection was significantly better than in those who had no resection (median survival 25.3 vs. 2.1 months, log-rank test P = 0.004). Patients with extrahepatic biliary obstruction secondary to HCC had a better chance of being treated by liver resection, which resulted in a significantly improved survival rate compared to patients with intrahepatic obstruction.