Molecular Update of β-Thalassemia Mutations in the Syrian Population: Identification of Rare β-Thalassemia Mutations

β-Thalassemia (β-thal) is an autosomal recessive disorder characterized by variable degrees of anemia, bone marrow hyperplasia, splenomegaly, and complications related to the severity of the anemic state. The β-thalassemias result from mutations in and around the β-globin gene (HBB) located as a cluster on the short arm of chromosome 11. In Syria, β-thal is highly prevalent. The main aim of this study was to identify the frequency of HBB mutations in 189 Syrian β-thal patients and carriers of β-thal. Out of the 189 patients and carriers recruited in this study, 181 patients had at least one HBB mutation and eight patients did not show any mutation. The 10 most frequent ones constituted 77.5% of all HBB mutations. These mutations in order of frequency were: IVS-I-110 (G?>?A) (17.0%), IVS-I-1 (G?>?A) (14.7%), codon 39 (C?>?T) (14.4%), IVS-II-1 (G?>?A) (9.8%), codon 8 (–AA) (6.2%), IVS-I-6 (T?>?C) (5.2%), IVS-I-5 (G?>?C) (4.9%), codon 5 (–C) (3.2%), IVS-I-5 (G?>?A) (3.2%) and codon 37 (G?>?A) (2.2%). Another 21 mutations were less frequent or sporadic. These results provide important tools for adapting a prenatal molecular diagnostic test for the Syrian population.     

Acute myocardial infarction: clinical characteristics, management and outcome in a university medical centre in a developing Middle Eastern country

BACKGROUND: The management and outcome of acute myocardial infarction (AMI) have not been well studied in developing countries, although demographic data from the World Health Organization indicate that developing countries contribute a major share to the global burden of cardiovascular disease. OBJECTIVES: To analyze the clinical characteristics, management and outcome of patients hospitalized with AMI in a university medical centre in a developing Middle Eastern country. METHODS: The study population comprised all patients hospitalized with AMI at the American University of Beirut between January 1, 1997, and December 30, 1998. The medical records of the patients were reviewed to determine their clinical characteristics, the diagnostic and invasive procedures used during the hospitalization, and any in-hospital complications, including death. RESULTS: The population comprised 184 patients with a mean age of 60+/-13 years. Fifty-two per cent of the infarcts were anterior and 76% developed Q waves. Fifty-one per cent of the patients received thrombolytic therapy. At discharge, 80% of the patients were given acetylsalicylic acid, 35% were given beta-blockers, 34% were given angiotensin-converting enzyme inhibitors and 30% were given statins. Seventy-two per cent of the patients underwent coronary angiography, 23% underwent percutaneous transluminal coronary angioplasty and 13% had coronary artery bypass grafting. The in-hospital mortality was 13%. The predictors of in-hospital mortality were advanced age (over 60 years), diabetes, prior AMI, Killip class greater than I and ejection fraction less that 40%. In contrast, the predictors of coronary angiography were younger age (less than 60 years), absence of diabetes or no history of AMI, Killip class I and ejection fraction greater than 40%. CONCLUSIONS: Coronary angiography after AMI was performed more frequently than expected in a university medical centre in a developing country, and it seemed to be selectively used in the low- risk patients rather than the high-risk ones. Furthermore, the underuse of medical therapy with beta-blockers and statins was evident. These findings should prompt cardiac societies in these countries to initiate educational campaigns focusing on the cost-effectiveness of therapy in AMI to optimize the use of their limited resources.     

LPS inhibits endothelin-1-mediated eNOS translocation to the cell membrane in sinusoidal endothelial cells

OBJECTIVE: The objectives of this study were to develop a model for studying endothelin-1-mediated eNOS regulation in cultured sinusoidal endothelial cells and determine the effect of endothelin-1 and endotoxin (LPS) on eNOS localization. METHODS: Changes in caveolin-1, calmodulin, and eNOS expression were determined by western blot and densitometric analysis. Endothelin receptor expression and localization and the intracellular localization of eNOS and caveolin-1 were assessed by confocal microscopy. RESULTS: Sinusoidal endothelial cells expressed caveolin-1 and calmodulin, and expression was altered in cultured and passaged cells. eNOS expression decreased significantly in 24-h cultured cells, with expression dropping below the level of detection in passaged cells. Both endothelin A and endothelin B receptors were expressed on the cell surface after 24 h in culture. In 24-h cultured cells, caveolin-1 was localized in the perinuclear region and cell membrane, while eNOS was predominantly localized in the perinuclear region, where it co-localized with caveolin-1. Endothelin-1 stimulated eNOS translocation to the cell membrane. Pretreatment with LPS markedly inhibited the endothelin-1-mediated eNOS translocation. CONCLUSIONS: These studies demonstrate an LPS-mediated uncoupling of endothelin receptor activation and eNOS translocation. This functional uncoupling may, in part, account for the hyperconstrictive effects of endothelin-1 during inflammatory conditions.     

Risk factors for local recurrence of large gastrointestinal lesions after endoscopic mucosal resection

Techniques in Coloproctology - Endoscopic mucosal resection (EMR) is the primary treatment modality for superficial gastrointestinal mucosal lesions > 2 cm. However, the...     

Pitfalls in diagnosis and clinical, echocardiographic, and hemodynamic findings in endomyocardial fibrosis: a 25-year experience

Endomyocardial fibrosis (EMF) is a fascinating disease entity of unknown etiology. It is prevalent in the tropical zone. Its essential features are the formation of fibrous tissue on the endocardium and to a lesser extent in the myocardium of the inflow tract and apex of one or both ventricles. It results in endocardial rigidity, atrioventricular valve incompetence secondary to papillary muscle involvement, and progressive reduction of the cavity of the involved ventricle leading to restriction in filling and atrial enlargement. This article will present 21 patients with EMF who were initially referred to our hospital from 1979 to 2004 with different diagnoses: rheumatic heart disease with mitral and or tricuspid regurgitation (n = 9), constrictive pericarditis (n = 6), restrictive cardiomyopathy (n = 1), hypertrophic cardiomyopathy apical type (n = 2), dilated cardiomyopathy (n = 2), and Ebstein malfunction of the tricuspid valve (n = 1). The clinical, echocardiographic, hemodynamic, and angiographic findings in these 21 patients are presented; echocardiographic findings lead to the right diagnosis. The presence of a small ventricle with obliteration of the apex and large atrium shown on two-dimensional echocardiography is highly suggestive of EMF.     

Incidence of atrial fibrillation in heart transplant patients: long-term follow-up

BACKGROUND: The incidence of atrial fibrillation (AF) in heart transplant patients has not been well documented. METHODS: To determine the incidence of AF in a cohort of patients undergoing cardiac transplantation, clinical data were obtained from a prospectively collected database for all consecutive orthotopic heart transplantation (OHT) patients and for all consecutive coronary artery bypass graft (CABG) surgery patients between January 1984 and March 2004 at our institution. A cohort of 1,714 OHT patients and low-risk CABG (normal ejection fraction [EF] and no left ventricular hypertrophy [LVH]) patients were age- and sex-matched. RESULTS: The average age in the two groups was 56 +/- 7 years with 87% male and 81% white race and body mass index (BMI) of 26 +/- 4. There were 3 cases of AF (0.3%) in the OHT group and 757 cases of AF (21%) in the low-risk CABG group. The strongest independent predictor of freedom from postoperative AF was having had a transplant (odds ratio [OR] 96, 95% confidence interval [CI] 13-720). The incidence of AF, atrial flutter (AFL), and supraventricular tachycardia (SVT) in OHT was 0.33, 2.8%, and 1.3%, respectively. Given that incidence of AF, AFL, and SVT in historical post-CABG population is 25%, 17%, and 4.3%, transplanted patients appear to have lower incidence of AF, AFL, and SVT than the reference population. Consistent with this, transplanted patients underwent few ablation procedures for atrial arrhythmias. Additionally, the three patients with AF had bicaval anastomoses suggesting the possibility of PACs originating in the donor superior vena cava (SVC) or IVC (inferior vena cava) initiating AF in these patients. CONCLUSIONS: In a cohort study of transplant and low-risk CABG patients, the strongest independent predictor of freedom from AF is having undergone transplant surgery. One potential explanation for the markedly lower incidence of AF may be effective isolation of thoracic veins with documented cases retaining the native SVC.     

Long-term outcome (up to 15 years) of balloon angioplasty of discrete native coarctation of the aorta in adolescents and adults

OBJECTIVES: This study evaluated the long-term follow-up results of balloon angioplasty (BA) in adolescent and adult patients with discrete coarctation of the aorta. BACKGROUND: Although the immediate and intermediate term results of BA for patients with aortic coarctation (AC) have been encouraging, there is a paucity of data on long-term follow-up results. METHODS: This basis of this study was follow-up of 49 patients (mean age, 22 +/- 7 years) undergoing BA for discrete AC at median interval of 10.2 years, including cardiac catheterization, magnetic resonance imaging, and Doppler echocardiography. RESULTS: No early or late deaths occurred. Balloon angioplasty produced a reduction in peak AC gradient from 66 +/- 23 mm Hg (95% confidence interval [CI]: 59.5 to 72.7) to 10.8 +/- 7 mm Hg (95% CI: 8.8 to 12.5) (p < 0.0001). Follow-up catheterization 12 months later revealed a residual gradient of 6.2 +/- 6 mm Hg (95% CI: 4.4 to 7.9) (p < 0.001). Four patients (7.5%) with suboptimal initial outcome with peak gradient >20 mm Hg had successful repeat angioplasty. Aneurysm developed at the site of dilation in four patients (7.5%). Magnetic resonance imaging follow-up results revealed no new aneurysm or appreciable changes in the size of pre-existing aneurysms, and no recoarctation was observed. Also, no appreciable changes in the Doppler gradient across the AC site were noted. The blood pressure had normalized without medication in 31 (63%) of the 49 patients. CONCLUSIONS: Long-term results of BA for discrete AC are excellent and should be considered as first option for treatment of this disease.     

Campylobacter fetus infection of an internal cardioverter defibrillator

Infection is a serious complication post implantation of an implantable cardiac defibrillator (ICD). We report a case of a 77-year-old man who had an ICD generator change complicated by a hematoma. The generator became infected at the time of Campylobacter fetus bacteremia. The ICD was removed and a new device was implanted without complication.     

Diabetic muscular infarction: emphasis on pathogenesis

Diabetic muscular infarction is a rare complication of diabetes. It usually occurs in those with target organ involvement of diabetes, generally affecting one or a group of muscles of the thigh, and can recur. The pathogenesis of the disease is still not clear. Here we report an unusual case of extensive muscle involvement of both thighs and calves, with special emphasis on pathogenesis.Abbreviations DMI Diabetic muscular infarction - MRI magnetic resonance imaging     

Left atrial flutter following pulmonary vein antrum isolation with radiofrequency energy: linear lesions or repeat isolation

INTRODUCTION: Left atrial flutter (LAFL) is a known complication of pulmonary vein isolation. Treatment of this arrhythmia currently involves both linear lesions as well as re-isolation. However, it is unknown if re-isolation alone is sufficient to prevent recurrence. This study reviews the incidence of LAFL following segmental PV antrum isolation (PVAI) in a large patient population and evaluates if re-isolation alone is sufficient to prevent recurrence. METHODS AND RESULTS: Seven hundred thirty-seven patients underwent PVAI. Twenty-three patients (3.1%) developed post-PVAI LAFL. All patients underwent a second procedure in which only repeat PVAI was done. During the second procedure, all flutter circuits were electroanatomically mapped. All patients were followed at 3, 6, and 12 months. All 23 patients demonstrated recovery in one or more PV. After repeat isolation of the PVs, 61% of patients were arrhythmia free off all antiarrhythmic drugs. A relationship between the presence/absence of pre-existing left atrial (LA) scar was observed. Of the 11 patients with pre-existing LA scar, 36% remained arrhythmia free off antiarrhythmic drugs. In contrast, of the 12 patients without pre-existing LA scar, 83% remained arrhythmia free off antiarrhythmic drugs (P = 0.03). CONCLUSION: Among patients with LAFL following PVAI, re-isolation alone is sufficient in preventing recurrence in patients without pre-existing LA scar. Patients with pre-existing LA scar tend to have recurrence requiring further ablation including linear lesions, and continue to need antiarrhythmic medications.