Initial results, predictors of success, and long-term outcome of primary coronary angioplasty for acute myocardial infarction in a community hospital.
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Aged↗
Biomedical subjects
N Sabri
Publications and source records attributed to N Sabri.
Electron tomography reveals posttranscriptional binding of pre-mRNPs to specific fibers in the nucleoplasm.
Using electron tomography, we have analyzed whether the Balbiani ring (BR) pre-mRNP particles in transit from the gene to the nuclear pore complex (NPC) are bound to any structure that could impair free diffusion through the nucleoplasm. We show that one-third of the BR particles are in contact with thin connecting fibers (CFs), which in some cases merge into large fibrogranular clusters. The CFs have a specific protein composition different from that of BR particles, as shown by immuno-EM. Moreover, we have identified hrp65 as one of the protein components of the CFs. The sequencing of hrp65 cDNA reveals similarities with hnRNP proteins and splicing factors. However, hrp65 is likely to have a different function because it does not bind to nascent pre-mRNA and is not part of the pre-mRNP itself. Taken together, our observations indicate that pre-mRNPs are not always freely diffusible in the nucleoplasm but interact with fibers of specific structure and composition, which implies that some of the posttranscriptional events that the pre-mRNPs undergo before reaching the NPC occur in a bound state.
Amino Acid Sequence↗
The Ct-RAE1 protein interacts with Balbiani ring RNP particles at the nuclear pore.
RAE1 is an evolutionarily conserved protein that associates with both mRNPs and nucleoporins, and may bridge the interaction between mRNP export cargoes and the nuclear pore complex (NPC). However, the mechanism by which RAE1 functions in mRNA export is still unknown and the time point at which RAE1 interacts with the exported RNP has not been directly investigated. Here we have addressed this question in the Balbiani ring (BR) system of Chironomus tentans using immunoelectron microscopy. The RAE1 protein of C. tentans, Ct-RAE1, is 70% identical to human RAE1/mrnp41 (hRAE1) and is recognized by antibodies raised against hRAE1. As in vertebrate cells, Ct-RAE1 is concentrated at the nuclear envelope and also dispersed throughout the nuclear interior. Here we show that Ct-RAE1 does not bind to the BR particle either cotranscriptionally or in the nucleoplasm. Instead, the interaction between Ct-RAE1 and the exported BR particle occurs at the NPC. Moreover, the localization of Ct-RAE1 at the NPC is correlated with the presence of an exported RNP in the NPC. Finally, the anti-RAE1 antibody does not label the cytoplasmic side of BR particles in transit through the central channel, which indicates that Ct-RAE1 either remains anchored at the nuclear side of the NPC during translocation of the RNP through the central channel or becomes transiently associated with the RNP but is rapidly released into the cytoplasm.
Amino Acid Sequence↗
Ascorbate increases electrotransformation efficiency of intact maize cells.
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Ascorbic Acid↗
Electropermeabilization of intact maize cells induces an oxidative stress.
By applying electric field pulses through cell suspensions, cell membranes can be permeabilized transiently, giving free access to the cytosol. Electropulsation is now routinely used in cell biology when introducing various molecules such as proteins and nucleic acids into the cell. But the molecular and cellular bases of cell electropermeabilization are still unclear. In the present study, we observed that electropermeabilization of intact black Mexican sweet (BMS) maize cells induces a generation of oxygen species (oxidative jump). Using the chemiluminescent probe lucigenin, we have shown that the electro-induced chemiluminescent response depends on the level of the stress factor as shown by its dependence on the electric parameters (electric field intensity, duration, and number of pulses). While the electroinduced cell permeabilization has a short life, the oxidative jump that is triggered by this electropermeabilization is a much longer-lived response. The electroinduced loss in viability is linearly correlated to permeabilization. However, there is no correlation between the oxidative jump and the loss in viability. The modulation of oxygen species electroinduction by antioxidant products (dimethylsulfoxide, sodium L-ascorbate, and glutathione) does not lead to an increase in cell viability. Such results are different to those observed with mammalian cells and indicate that even if the same phenomenon is observed with mammalian cells and indicate that even if the same phenomenon is observed when pulsing mammalian or intact plant cells, the associated metabolic response is not the same.
Antioxidants↗
Closure of a persistent femoral artery pseudoaneurysm complicating coronary angioplasty using the femostop compression device and direct ultrasound visualization.
Nonsurgical closure of femoral artery pseudoaneurysm (PSA), using ultrasound guidance and compression with the ultrasound probe or a C-clamp, has been previously described. We report a patient in whom a different compression device was used (the Femostop) which also allows direct ultrasound visualization of the PSA and femoral vessels at the site of compression. This resulted in adequate PSA with preservation of flow in both artery and vein throughout the procedure.
Aneurysm↗
Frequency of coronary artery disease and left ventricle dysfunction in cocaine users.
To evaluate the spectrum of coronary artery disease (CAD) in cocaine users, coronary angiograms obtained from 33 patients (26 men [79%] and 7 women [21%], mean age 37 years) with history of cocaine use and cardiac symptoms were retrospectively reviewed. Clinical indications for coronary angiograms included chest pain (n = 28), congestive failure (n = 4) and complete heart block (n = 1). Coronary angiograms were reviewed independently by 2 angiographers unaware of patient's clinical status. Thirteen patients (40%) had normal coronary angiograms, and 20 (60%) had CAD; 7 (21%) had mild CAD (less than or equal to 70% diameter stenosis), and 13 (40%) had significant CAD (greater than 70% diameter stenosis). Of 13 patients with significant CAD, 7 had 1-vessel, 4 had 2-vessel and 2 had 3-vessel CAD. There was enzymatic evidence of myocardial infarction in 12 of 33 patients (36%); all 12 had CAD (10 with significant and 2 with mild CAD). Mean age and number of risk factors (serum total cholesterol, cigarette smoking, systemic hypertension, diabetes mellitus, family history of CAD, and obesity) in patients with CAD (mild or significant) and with normal coronary angiograms were not statistically different. Left ventricular ejection fraction was normal in 15 patients (45%) and depressed in 18 (55%). All patients with CAD and low ejection fractions (n = 12) had regional wall motion abnormalities, whereas all those with normal coronary arteries and low ejection fraction (n = 6) had global hypokinesia.
Adult↗
Intracoronary urokinase as an adjunct to percutaneous transluminal coronary angioplasty in patients with complex coronary narrowings or angioplasty-induced complications.
The effectiveness of intracoronary urokinase infusion as an adjunct to percutaneous transluminal coronary angioplasty (PTCA) was studied in 50 patients who underwent angioplasty for complex coronary narrowings or had thromboembolic complications during PTCA (29 [58%] men, 3 [6%] stable and 37 [74%] unstable angina, and 16 [32%] prior coronary bypass surgery). The primary indications for intracoronary urokinase infusion were intracoronary thrombus in 27 patients (54%), distal coronary embolization in 9 (18%), and abrupt reclosure in 14 (28%). Urokinase was infused in a mean (+/- standard deviation) dosage of 399,000 +/- 194,000 IU (range 150,000 to 1,000,000) at an average rate of 5,000 to 20,000 IU/min. Angiographic success was achieved in 43 patients (86%). Complications included the need for urgent bypass surgery in 3 patients, Q-wave myocardial infarction in 2, and non-Q-wave myocardial infarction in 12 (8 of whom had peak creatine kinase less than twice the upper normal limit). The incidence of myocardial infarction was significantly higher in patients with vein grafts (69%) than in those with PTCA of native vessels (14%). Two patients died (1 massive gastrointestinal necrosis 24 hours after angioplasty, and 1 after urgent bypass surgery). Mean (+/- standard deviation) fibrinogen levels were 355 +/- 73 mg/dl before urokinase infusion, and 361 +/- 70, twelve hours afterward. Three patients had local bleeding, but no transfusions were needed. It is concluded that intracoronary urokinase is a safe and effective adjunct to PTCA in patients with associated thrombi and may improve the success rate in angioplasty complicated by thrombus formation.
Aged↗
Application of coronary angioplasty to the septal perforator arteries.
Significant coronary artery disease affecting the septal perforator arteries can cause anginal pain, rhythm disturbances, or septal infarction. However, since these vessels are usually inaccessible to coronary bypass surgery, there is a tendency among angiographers and angioplasters to overlook lesions of the septal perforator arteries. Our experience suggests that if medical treatment is not sufficient to treat clinical manifestations resulting from septal perforator disease, then coronary angioplasty can be considered a therapeutic alternative for revascularization. We herein present 11 patients who underwent coronary angioplasty of a major septal artery and discuss angiographic and technical aspects of the procedure.
Angina, Unstable↗
Intracoronary recombinant tissue-type plasminogen activator in unstable angina: a pilot angiographic study.
The effectiveness of intracoronary (IC) recombinant thromboplastin activator (rt-PA) was prospectively evaluated in seven patients with unstable angina and complex angiographic lesions or intracoronary filling defects (ICFD). There were four men and three women, with a mean age of 60 years. Three patients had multivessel disease and all patients had rest angina; none had evolving myocardial infarction. All patients were pretreated with aspirin and were given heparin. IC rt-PA was infused at the rate of 1 mg/min to a total of 50 mg, and angiographic changes were observed every 15 minutes. At 50 minutes, angiographic improvement was seen in two patients (28%), one of whom had complete and one of whom had partial resolution of ICFD. In two patients (28%) there was no change in the lesion, and three patients (42%) had worsening of the lesion appearance. In two of the latter, paradoxical closure was observed at the end of the infusion, and was treated successfully with ad hoc emergency angioplasty. This pilot study suggests that IC rt-PA at the dosage used may have variable effects on complex coronary lesions associated with unstable angina, and this may be of relevance in further trials evaluating IC thrombolysis in unstable coronary ischemic syndromes.
Angina, Unstable↗
Effect of atherosclerosis and hypertension on arterial epistaxis.
Eye fundus examination in twenty cases of hypertensive nose bleeding was carried out to evaluate the effect of hypertension and atherosclerosis on epistaxis. Arteriolar attenuation, atherosclerosis and venous congestion were detected in most of the cases. None showed haemorrhages or exudates. Hypertension and atherosclerosis seem to maintain and increase the severity of epistaxis, once it has been initiated by other factors.
Adult↗
Complications of cardiac catheterization, coronary angiography, and coronary interventions.
Cardiac catheterization and coronary angiography have evolved, especially after the advent of percutaneous coronary interventions. Although older patients with more advanced disease are being studied, the overall rate of complications has not dramatically increased and the spectrum of complications has somewhat changed to select the more acute nature of the procedures performed. Careful prophylactic measures such as anticoagulation, ischemia prevention, blood pressure control, hydration as well as the availability of defibrillation and pharmacologic and mechanical means of circulatory support have helped minimize these complications and improve outcome.
Anaphylaxis↗