Correlation between severity of coronary artery stenosis and perfusion defect assessed by SPECT myocardial perfusion imaging

Numerous non-invasive techniques are developed to assess the severity of coronary artery disease (CAD). Coronary angiography (CAG) is an established method for the diagnosis and to quantify the severity of coronary artery stenosis. Single photon emission computed tomography-myocardial perfusion imaging (SPECT-MPI) using Technetium-99m (Tc-99m) tetrofosmin is also a useful established technique for the assessment of severity of CAD. This prospective observational study was carried out in Bangabandhu Sheikh Mujib Medical University (BSMMU) to assess the severity of coronary artery stenosis using Tc-99m Single Photon Emission Computed Tomography myocardial perfusion imaging (SPECT-MPI) in comparison with CAG. Eighty two (82) consecutive patients with mean age 53.51(SD+/-7.08) years and Candian Cardiovascular Society (CCS) class I and II severity of chest pain, male: female ratio (4.8:1) was studied. Tc-99m SPECT-MPI was performed by one-day exercise stress and rest protocol. A total of two hundred and forty six coronary artery territories examined in this study. By CAG normal coronary arteries were found in seventy six, moderate stenosis in twenty four and severe stenosis in one hundred and forty-six coronary artery territories whereas SPECT-MPI found normal perfusion in twenty seven, mild perfusion abnormality in seventeen, moderate perfusion abnormality in thirty two and severe perfusion abnormality in one hundred and sixty five coronary artery territories. Sensitivity and specificity of SPECT-MPI using Tc-99m tetrofosmin in detecting coronary artery stenosis were 87.09% and 80.95% respectively. The positive predictive value, negative predictive value and accuracy of the test were 91.01%, 73.91% and 85.18% respectively. From this study it can be concluded that Tc-99m SPECT-MPI was a safe, effective and excellent non-invasive tool for the detection of severity of coronary artery lesion and can be used to predict severity of CAD.     

Endoscopic Diagnosis of a Clinically Silent Aortoesophageal Fistula: Case Report and Review of the Literature

We report a rare case of a secondary aortoesophageal fistula discovered incidentally during elective upper endoscopy. The patient had previously undergone repair of a descending thoracic aortic aneurysm with a Dacron interposition graft. Esophagoscopy 2 months after the aneurysm repair demonstrated a large mid-esophageal erosion with visualization of the aortic graft at the base. The aortoesophageal fistula had been clinically silent to this point. During preparation for surgery the patient developed large-volume esophageal hemorrhage and died following attempted endovascular repair of the fistula. A review of the literature on the diagnosis and surgical management of aortoesophageal fistula is presented.Presented at the 30th Annual Meeting of the Military Society for Vascular Surgery, Bethesda, MD, December 5, 2002.     

On admission hypomagnesemia in critically ill children: Risk factors and outcome

Objective  

To determine the frequency and associated risk factors of hypomagnesemia in pediatric intensive care unit on admission in a developing country.     

Hierarchical model-based tracking of cervical vertebrae from dynamic biplane radiographs

We present a novel approach for automatically, accurately and reliably determining the 3D motion of the cervical spine from a series of stereo or biplane radiographic images. These images could be acquired through a variety of different imaging hardware configurations. We follow a hierarchical, anatomically-aware, multi-bone approach that takes into account the complex structure of cervical vertebrae and inter-vertebrae overlapping, as well as the temporal coherence in the imaging series. These significant innovations improve the speed, accuracy, reliability and flexibility of the tracking process. Evaluation on cervical data shows that the approach is as accurate (average precision 0.3 mm and 1°) as the expert human-operator driven method that was previously state of the art. However, unlike the previously used method, the hierarchical approach is automatic and robust; even in the presence of implanted hardware. Therefore, the method has solid potential for clinical use to evaluate the effectiveness of surgical interventions.     

The Frequency and Functional Impact of Overlapping Hypertension on Hypertrophic Cardiomyopathy: A Single-Center Experience

J Clin Hypertens (Greenwich) Between 1995 and 2005, 196 adults with hypertrophic cardiomyopathy (HCM) were evaluated. Among these, 122 (62%, group 1) patients also had systemic hypertension. The clinical presentation, management, outcome, and echocardiographic findings of these patients were compared with 74 (38%, group 2) patients without systemic hypertension. Patients in group 1 were older at the time of HCM diagnosis and had a higher prevalence of diabetes (28% vs 9%; P=.02) and coronary artery disease (40% vs 25%; P=.03). In addition, echocardiography showed a significantly higher prevalence of systolic anterior motion of the anterior mitral valve in association with dynamic left ventricular outflow obstruction (52% vs 19%; P=.02) and mitral annular calcification (27% vs 13%; P=.03) in group 1 patients. Left ventricular wall thickness (17 mm vs 19 mm), end-diastolic diameter (42 mm vs 42 mm), resting outflow tract gradient >30 mm Hg (17% vs 16%), and ejection fraction (65% vs 64%) were similar in the two groups. HCM frequently coexists with systemic hypertension in the adult population. Presence of systemic hypertension in HCM patients is associated with older age and higher risk of diabetes, coronary artery disease, and noncardiac death.     

The Toll-like receptor 2 (TLR2) ligand FSL-1 is internalized via the clathrin-dependent endocytic pathway triggered by CD14 and CD36 but not by TLR2

Little is known of how Toll-like receptor (TLR) ligands are processed after recognition by TLRs. This study was therefore designed to investigate how the TLR2 ligand FSL-1 is processed in macrophages after recognition by TLR2. FSL-1 was internalized into the murine macrophage cell line, RAW264.7. Both chlorpromazine and methyl-β-cyclodextrin, which inhibit clathrin-dependent endocytosis, reduced FSL-1 uptake by RAW264.7 cells in a dose-dependent manner but nystatin, which inhibits caveolae- and lipid raft-dependent endocytosis, did not. FSL-1 was co-localized with clathrin but not with TLR2 in the cytosol of RAW264.7 cells. These results suggest that internalization of FSL-1 is clathrin dependent. In addition, FSL-1 was internalized by peritoneal macrophages from TLR2-deficient mice. FSL-1 was internalized by human embryonic kidney 293 cells transfected with CD14 or CD36 but not by the non-transfected cells. Also, knockdown of CD14 or CD36 in the transfectants reduced FSL-1 uptake. In this study, we suggest that (i) FSL-1 is internalized into macrophages via a clathrin-dependent endocytic pathway, (ii) the FSL-1 uptake by macrophages occurs irrespective of the presence of TLR2, and (iii) CD14 and CD36 are responsible for the internalization of FSL-1.     

Mediastinal atypical carcinoid and neurofibromatosis type 1

We report a case of mediastinal atypical carcinoid in a 63-year-old woman with neurofibromatosis type 1 (NF-1), who presented with shortness of breath and a bulky mediastinal mass. Initial consideration was given to a neurogenic tumor. However, on thoracoscopic biopsy, the histologic appearance was consistent with an atypical carcinoid. Carcinoid tumors have been reported in association with NF-1 previously, but commonly in such unusual sites as the ampulla of Vater and duodenum and not in the thorax. The bulky, extensive, and highly vascular nature of the lesion precluded resection or debulking surgery. To our knowledge, there are no previous reports of atypical carcinoid of the lung or mediastinum in a patient with neurofibromatosis. This case report, therefore extends the spectrum of solid neoplasia in general and carcinoid tumors in specific, as they occur in association with NF-1.     

Uretero-vesical junction obstruction presenting as gaint hydronephrosis

A rare case of giant hydronephrosis due to ureterovesical junction obstruction is presented.