[Examination of the mechanical properties of zirconia and porcelain blocks after grinding with smooth and coarse diamond burrs].

UNLABELLED: Porcelain and Zirconia are widely used materials in oral rehabilitation for fixed partial dentures, FPD. Among many important properties, A FPD should be able to resist bite forces, the harsh oral environment and to remain intact for a long period of time. When coming back from the dental laboratory, the mechanical properties of the FPD are optimal. But it is not uncommon for the dentist to perform a machining procedures on the restoration in order to achieve good fitting to the prepared teeth. In most cases these modifications are made using high speed dental hand piece, and diamond burs. The surface integrity of the restoration is an important parameter that influences on the restoration strength and durability. The more smooth the restoration surface is, it is less prone to fracture, and is less prone to coloring and plaque retention. Therefore, every modification the dentist makes on the restoration is not recommended. In some cases, the adjustments are made on a FPD which is already cemented to the teeth. If the teeth are vital, the implications of the machining of the restoration are even more destructive. As a result of the friction between the bur and the restoration, the temperature rises. There is a risk of pulp necrosis in temperature above 42 degrees C. The purpose of this study is to compare the mechanical properties of Zirconia and Porcelain blocks after grinding with smooth burs made in a new technology, Magic touch, Strauss co. (Ranana, Israel) and coarse burs. MATERIALS AND METHODS: blocks of Porcelain MARK II for CEREC (VIDENT), and Zirconia IPS e.max ZirCAD (Ivoclar Vivadent) were sliced to slices of 1mm and underwent drilling using the two kinds of burs, using thermocoupling--Almemo, Holzkirchen, Germany. So that the rise in temperature was measured through the drilling. Blocks of Porcelain and Zirconia were machined with the two kinds of burs, and their surface roughness was examined with Mitutoyo Surftest 402 Profilometer. Further examination was made with SEM micrographs. RESULTS: the samples machined with Magic touch burs, both on Porcelain and Zirconia, were significantly smoother than the samples machined with coarse burs (P 0.05). There was no significant rise in temperature (above 42 degrees C) using both kind of burs, on both Porcelain and Zirconia. The SEM microscopy demonstrates smoother surface of the porcelain and Zirconia which were grinded with Magic touch burs. CONCLUSIONS: Magic touch diamond burs, enables the dentist to perform fit adjustments on Porcelain or Zirconia FPD, leaving the restoration with minimum surface roughness, without elevating the temperature to high values, permitting both the tooth and the restoration to remain strong and durable for a longer period of time.

Outcome of hospitalized MDR-TB patients: Israel 2000-2005.

MDR-TB has emerged in Israel following an immigrations wave from the Former Soviet Union (FSU) and Ethiopia. The purpose of this study was to outline characteristics and outcome of hospitalized MDR-TB patients. We retrospectively summarized charts of MDR-TB patients hospitalized in the national referral tuberculosis centers from January 2000 to December 2005, and followed them for 2 years. One hundred thirty-two patients were identified with a median age of 40 years and male predominance (77%). The majority of the patients were immigrants from FSU (83%) and Ethiopia (7.6%). They were characterized by alcohol (25.8%) and IV drug abuse (23.5%), presented with advanced disease manifested by hypoalbuminemia (50.8%) and smear positivity (70.5%). Cure was achieved in 50.3% and 30.4% died. Factors independently associated with death were patients' age (OR = 1.036 for each year, 95%CI 1.0-1.1, p = 0.014), hypoalbuminemia (OR = 2.95, 95%CI 1.1-7.6, p = 0.025), smear positivity at diagnosis (OR = 3.7, 95%CI 1.2-11.4, p = 0.023), alcohol abuse (OR = 4.8, 95%CI 1.7-13.7, p = 0.004) and XDR-TB resistance pattern (OR 8.3, 95%CI 1.5-44.6, p = 0.014). This study brings out the poor prognosis of a highly vulnerable immigration population. Efforts should be focused on earlier diagnosis and treatment in a well controlled hospital environment and to professional support groups to attend to this population's special needs.

Liver tuberculosis in an HIV patient: diagnosis and management.

Hepatic involvement is common in miliary and extra-pulmonary tuberculosis but is usually clinically silent. Therefore, it is rarely diagnosed. We report the case of a patient that presented with prolonged fever and hepatomegaly. Liver biopsy revealed non-necrotizing granulomas that led in turn to the diagnosis of generalized tuberculosis and HIV infection. The patient reported an old untreated tuberculosis and depression of the immune system provoked the reactivation of this old tuberculosis focus. We describe the clinical course of the disease and the challenges associated with the complexity of the treatment. Diagnosis of hepatic tuberculosis requires a high degree of suspicion especially in AIDS patients who show atypical presentations. However, it is a potential curable disease and good results have been obtained with the four drug regimen.

Involvement of autoimmunity in the pathogenesis of aggressive periodontitis.

The aim of this study was to investigate the involvement of autoimmune reactions to native and post-translationally modified extracellular matrix components in the pathogenesis of periodontitis. Sera from individuals with aggressive periodontitis (AgP, n = 25), chronic periodontitis (CP, n = 14), and gingivitis (G, n = 18) were tested for the presence of autoantibodies against: (a) native collagen type I (CI) and collagen type III (CIII); (b) CI and CIII post-translationally modified by reactive oxygen species (ROS) of the type present during inflammation; and (c) citrullinated filaggrin-derived peptides (CCP). Autoantibodies to native and ROS-modified CI and CIII as well as autoantibodies to CCP were observed exclusively in patients with AgP and not in those with CP or G. In conclusion, autoimmune reactions to native and post-translationally modified self-antigens may play a role specifically in the pathogenesis of AgP.

A novel microscopic assay for oral malodor-related microorganisms.

Previous research has shown that the production of volatile sulfide compounds (VSC) by oral bacteria is associated with oral malodor. In the present study, we report a novel technique (microscopic sulfide assay (MSA)) for the quantification of VSC-producing oral microorganisms. The MSA was performed by overnight incubation of saliva samples in the presence of ferrous sulfate and sodium thiosulfate, followed by digital analysis of cells stained black due to cell-associated precipitation of ferric sulfide. This method was found to correlate significantly with oral malodor parameters, including mean odor judge scores (two judges, r = 0.48 and p = 0.001) and Halimeter® readings (r = 0.53 and p < 0.001), in a group of 42 subjects. As compared with odor judge scores as the gold standard, the new MSA technique yielded a diagnostic accuracy of 0.7 (ROC, p = 0.023). Results indicate that the MSA may serve as a diagnostic technique for assessing oral malodor levels and aid in identifying the particular bacteria involved in this condition.

A phase I study of 99mTc-hR3 (DiaCIM), a humanized immunoconjugate directed towards the epidermal growth factor receptor.

A phase I trial was conducted to evaluate the safety, tumour and normal tissue localization, pharmacokinetics and radiation dosimetry of Tc-hR3, a humanized monoclonal antibody directed towards the epidermal growth factor receptor, in 12 patients with recurrent or metastatic epithelial malignancies. Patients were injected intravenously with 3.0 mg or 6.0 mg (1010 MBq) of Tc-hR3. Blood and plasma concentrations of radioactivity were measured and a complete 24 h urine collection was obtained. Whole-body images were acquired up to 24 h post-injection and normal organ uptake quantified. Radiation dosimetry was estimated using MIRDose. Safety was evaluated by clinical observation, biochemical/haematological testing and by measuring immune response to Tc-hR3. There were no adverse effects, no changes in biochemical/haematological indices and no immune response to Tc-hR3. Tc-hR3 was rapidly cleared from the blood with a distribution half-life of 10.8+/-3.8 min. The volume of distribution, and clearance, were 180+/-37 ml.kg and 14+/-3 ml.kg.min, respectively. The elimination phase could not be discerned due to increasing blood radioactivity at later times. About 19-24% was excreted in the urine. Normal tissue uptake was mainly in the liver (44-50%), spleen (3-4%) and kidneys (3%). Imaging was positive in one patient with squamous cell carcinoma of the mouth and an involved cervical lymph node. The whole-body radiation dose from Tc-hR3 was 1.34+/-0.02x10 mSv.Bq. We conclude that Tc-hR3 exhibited an excellent safety profile. Future studies to determine the sensitivity and specificity of imaging with Tc-hR3 in a larger group of patients with pre-selection for epidermal growth factor receptor positivity are planned.

Amplified delivery of indium-111 to EGFR-positive human breast cancer cells.

A method is described to amplify the delivery of 111In to human breast cancer cells utilizing a novel human serum albumin-human EGF (HSA-hEGF) bioconjugate substituted preferentially in the HSA domain with multiple DTPA metal chelators for 111In. 111In-DTPA-HSA-hEGF exhibited a lower receptor-binding affinity than 111In-DTPA-hEGF but was rapidly and specifically bound, internalized and translocated to the nucleus in EGFR-positive MDA-MB-468 breast cancer cells. 111In-DTPA-HSA-hEGF was cytotoxic in vitro mainly through the emission of short-range Auger electrons and partially through the effects of the hEGF moiety to MDA-MB-468 cells overexpressing EGFR (1-2 x 10(6) receptors/cell) but not towards MCF-7 breast cancer cells with a 100-fold lower level of EGFR on their surface. The cytotoxicity in vitro against MDA-MB-468 cells of 111In-DTPA-HSA-hEGF substituted with nine DTPA chelators was enhanced 4-fold compared to 111In-DTPA-hEGF monosubstituted with DTPA. Studies are planned to further evaluate 111In-DTPA-HSA-hEGF in vivo as a new imaging and targeted radiotherapeutic agent for breast cancer.

Appropriate procedures for the safe handling and pathologic examination of technetium-99m-labelled specimens.

Technetium 99m may now be used to identify sentinel nodes for surgical excision in a growing number of cancer sites. The pathology specimens of these sentinel nodes and of any injected tumoural sites are radioactive. Consequently, specific clinical and laboratory procedures must be developed to handle these specimens safely. It is recommended that specimens containing the injection site should be quarantined for a period to permit decay of radioactivity. This quarantine does delay the reporting of pathology results to surgeons, oncologists and other clinicians, but it does not adversely affect final patient management.

Stents in total occlusion for restenosis prevention. The multicentre randomized STOP study. The Israeli Working Group for Interventional Cardiology.

AIMS: This multicentre randomized study set out to evaluate whether coronary stenting improves the results of successful balloon angioplasty for chronic total occlusion. Balloon angioplasty for chronic total occlusion has a high restenosis rate. Several reports have suggested that coronary stenting may decrease the likelihood of restenosis and reocclusion. METHODS AND RESULTS: Patients with total coronary artery occlusions who had an optimal PTCA result were randomized either to no further treatment or additional stent implantation. The AVE microstent was used and all patients were scheduled for a 1-, 3-, and 6-month clinical follow-up. Repeat coronary angiography to assess the rate and pattern of restenosis was performed at 6 months or earlier if clinically indicated. Ninety-six patients were enrolled in this study. The mean age was 59. 3+/-10.3 years and 15 were females. Forty-eight patients were randomized to the stent arm, receiving 52 stents (lengths 18-39 mm). Stent implantation was successful in all and there were no major procedure-related complications. Sixty-nine patients (72%) were restudied after 6 months. The binary restenosis rates (50%), in the PTCA arm were 70.9% with a minimal lumen diameter of 1.01+/-0.79 mm compared to 42.1% in the stent arm with a minimal lumen diameter of 1.63+/-1.02 mm (P=0.034). Reocclusion occurred in 7.9% in the stent group compared to 16.1% in the PTCA group. Restenosis in the PTCA group was focal in 88% of patients and occurred at the point of total obstruction (within 5 mm), compared to diffuse instent restenosis, which occurred in 54% of the patients in the stent group. CONCLUSION: Coronary stenting can significantly decrease the rate of restenosis and reocclusion of total occlusions. As restenosis in the stent group was more diffuse, care should be taken to implant short stents at the site of occlusion.

Treatment of nonresectable hepatocellular carcinoma with intrahepatic 90Y-microspheres.

UNLABELLED: Treatment for nonresectable hepatocellular carcinoma (HCC) is palliative. The relatively greater arteriolar density of hepatic tumors compared with normal liver suggests that intrahepatic arterial administration of 90Y-microspheres can be selectively deposited in tumor nodules and results in significantly greater radiation exposure to the tumor than external irradiation. The purpose of this study was to determine the proportion (frequency) and duration of response, survival, and toxicity after intrahepatic arterial injection of 90Y-microspheres in patients with HCC. METHODS: Patients with documented HCC, Eastern Cooperative Oncology Group performance status 0-3, adequate bone marrow, and hepatic and pulmonary function were eligible for study. Patients who had significant shunting of blood to the lungs or gastrointestinal (GI) tract or who could not undergo cannulation of the hepatic artery were excluded. Patients received a planned dose of 100 Gy through a catheter placed into the hepatic artery. RESULTS: Twenty-two patients were treated with 90Y-microspheres; 20 of the treated patients (median age, 62.5 y) were evaluated for treatment efficacy. Nine patients were Okuda stage I, and 11 were Okuda stage II. The median dose delivered was 104 Gy (range, 46-145 Gy). All 22 treated patients experienced at least 1 adverse event. Of the 31 (15%) serious adverse events, the most common were elevations in liver enzymes and bilirubin and upper GI ulceration. The response rate was 20%. The median duration of response was 127 wk; the median survival was 54 wk. Multivariable analysis suggested that a dose >104 Gy (P = 0.06), tumor-to-liver activity uptake ratio >2 (P = 0.06), and Okuda stage I (P = 0.07) were associated with longer survival. CONCLUSION: Significantly higher doses of radiation can be delivered to a HCC tumor by intrahepatic arterial administration of 90Y-microspheres than by external beam radiation. This treatment appears to be beneficial in nonresectable HCC with acceptable toxicity.

A comparison of EGF and MAb 528 labeled with 111In for imaging human breast cancer.

UNLABELLED: Our objective was to compare 111In-labeled human epidermal growth factor (hEGF), a 53-amino acid peptide with anti-epidermal growth factor receptor (EGFR) monoclonal antibody (MAb) 528 (IgG2a) for imaging EGFR-positive breast cancer. METHODS: hEGF and MAb 528 were derivatized with diethylenetriamine pentaacetic acid (DTPA) and labeled with 111In acetate. Receptor binding assays were conducted in vitro against MDA-MB-468 human breast cancer cells. Biodistribution and tumor imaging studies were conducted after intravenous injection of the radiopharmaceuticals in athymic mice bearing subcutaneous MCF-7, MDA-MB-231, or MDA-MB-468 human breast cancer xenografts or in severe combined immunodeficiency mice implanted with a breast cancer metastasis (JW-97 cells). MCF-7, MDA-MB-231, JW-97, and MDA-MB-468 cells expressed 1.5 x 10(4), 1.3 x 10(5), 2.7 x 10(5), and 1.3 x 106 EGFR/cell, respectively in vitro. RESULTS: 111In-DTPA-hEGF and 111In-DTPA-MAb 528 bound with high affinity to MDA-MB-468 cells (Ka of 7.5 x 10(8) and 1.2 x 10(8) L/mol, respectively). 111In-DTPA-hEGF was eliminated rapidly from the blood with < 0.2% injected dose/g (%ID/g) circulating at 72 h after injection, whereas 111In-DTPA-MAb 528 was cleared more slowly (3%ID/g in the blood at 72 h). Maximum localization of 111In-DTPA-hEGF in MDA-MB-468 tumors (2.2 %ID/g) was 10-fold lower than with 111In-DTPA-MAb 528 (21.6 %ID/g). There was high uptake in the liver and kidneys for both radiopharmaceuticals. Tumor-to-blood ratios were greater for 111In-labeled hEGF than for MAb 528 (12:1 versus 6:1), but all other tumor-to-normal tissue ratios were higher for MAb 528. MDA-MB-468 and JW-97 tumors were imaged successfully with both radiopharmaceuticals, but tumors were more easily visualized using 111In-labeled MAb 528. There was no direct quantitative relationship between EGFR expression on breast cancer cell lines in vitro, and tumor uptake of the radiopharmaceuticals in vivo, but control studies showed that tumor uptake was receptor mediated. CONCLUSION: Our results suggest that the tumor uptake in vivo of receptor-binding radiopharmaceuticals is controlled to a greater extent by their elimination rate from the blood than by the level of receptor expression on the cancer cells. Radiolabeled anti-EGFR MAbs would be more effective for tumor imaging in cancer patients than peptide-based radiopharmaceuticals such as hEGF, because they exhibit higher tumor uptake at only moderately lower tumor-to-blood ratios.

Minimal heparinization in coronary angioplasty--how much heparin is really warranted?

The purpose of the study was to assess the results of percutaneous transluminal coronary angioplasty (PTCA), performed with a single intravenous bolus of 2,500 U of heparin, in a nonemergency PTCA cohort. Three hundred of 341 consecutive patients (87.9%) undergoing PTCA were prospectively enrolled in the study. They received heparin, 2,500-U intravenous bolus, before PTCA, with intention of no additional heparin administration. Patient and lesion characteristics as well as PTCA results were evaluated independently by 2 physicians. Patients were followed up by structured telephone questionnaires at 1 and 6 months after PTCA. Mean activated clotting time obtained 5 minutes after heparin administration was 185+/-19 seconds (range 157 to 238). There were 3 (1%) in-hospital major adverse cardiovascular events: 2 deaths (0.66%), 1 (0.33%) Q-wave myocardial infarction. Emergency coronary surgery and stroke were not reported. Six patients (2%) experienced abrupt coronary occlusion within 14 days after PTCA, warranting repeat target vessel revascularization. Angiographic and clinical success were achieved in 96% and 93.3%, respectively. No bleeding or vascular complications were recorded. Six-month follow-up (184 patients) revealed 3 cardiac deaths (1 arrhythmic, 2 after cardiac surgery), 1 Q-wave myocardial infarction, and 9.7% repeat target vessel revascularization. This study suggests that very low doses of heparin and reduced activated clotting time target values are safe in non-emergency PTCA, and can reduce bleeding complications, hospital stay, and costs. Larger, randomized, double-blind heparin dose optimization studies need to confirm this notion.

111In-labeled EGF is selectively radiotoxic to human breast cancer cells overexpressing EGFR.

UNLABELLED: Our objective was to determine whether the internalization and nuclear translocation of human epidermal growth factor (hEGF) after binding to its cell surface receptor (EGFR) could be exploited to deliver the Auger electron emitter 111In into EGFR-positive breast cancer cells for targeted radiotherapy. METHODS: hEGF was derivatized with diethylenetriamine pentaacetic acid (DTPA) and radiolabeled with 111In-acetate. The internalization of 111In-DTPA-hEGF by MDA-MB-468 breast cancer cells (1.3x10(6) EGFRs/cell) was determined by displacement of surface-bound radioactivity by an acid wash. The radioactivity in the cell nucleus and chromatin, isolated by differential centrifugation, was measured. The effect on the growth rate of MDA-MB-468 or MCF-7 (1.5x10(4) EGFRs/cell) cells was determined after treatment in vitro with 111In-DTPA-hEGF, unlabeled DTPA-hEGF, or 111In-DTPA. The surviving fraction of MDA-MB-468 or MCF-7 cells treated in vitro with 111In-DTPA-hEGF was determined in a clonogenic assay. The radiotoxicity in vivo against normal hepatocytes or renal tubular cells was evaluated by measuring alanine aminotransferase (ALT) or creatinine levels in mice administered high amounts of 111In-DTPA-hEGF (equivalent to human doses up to 14,208 MBq) and by light and electron microscopy of the tissues. RESULTS: Approximately 70% of 111In-DTPA-hEGF was internalized by MDA-MB-468 cells within 15 min at 37 degrees C and up to 15% was translocated to the nucleus within 24 h. Chromatin contained 10% of internalized radioactivity. The growth rate of MDA-MB-468 cells was decreased 3-fold by treatment with 111In-DTPA-hEGF (45-60 mBq/cell). Treatment with unlabeled DTPA-hEGF caused a 1.5-fold decrease in growth rate, whereas treatment with 111In-DTPA had no effect. Targeting of MDA-MB-468 cells with up to 130 mBq/cell of 111In-DTPA-hEGF resulted in a 2-logarithm decrease in their surviving fraction. No decrease in the growth rate or surviving fraction of MCF-7 cells was evident. There was no evidence of hepatotoxicity or renal toxicity in mice administered high amounts of 111In-DTPA-hEGF. Radiation dosimetry estimates suggest that the radiation dose to an MDA-MB-468 cell targeted with 111In-DTPA-hEGF could be as high as 25 Gy with up to 19 Gy delivered to the cell nucleus. CONCLUSION: 111In-DTPA-hEGF is a promising novel radiopharmaceutical for targeted Auger electron radiotherapy of advanced, hormone-resistant breast cancer.

Quantitative comparison of leakage under the tourniquet in forearm versus conventional intravenous regional anesthesia.

UNLABELLED: We compared the quantitative leakage between forearm and conventional IV regional anesthesia (IVRA). Forearm IVRA remains unpopular because of the theoretical risk of local anesthetic leakage through the interosseous vessels. IVRA was simulated on the forearm or arm during two separate, randomized sessions using a double tourniquet in 14 volunteers. A radiolabeled substance, DISIDA (99m Tc-disofenin) with a structure similar to lidocaine, was injected instead of local anesthetic. Volumes of 0.4 mL/kg (maximum 25 mL), were used for forearm IVRA and 0.6 mL/kg (maximum 45 mL) for conventional IVRA. A gamma camera recorded radioactivity levels in the limb distal to the tourniquet every 30 s while the tourniquet was inflated (25 min) and for 20 min postdeflation. The leakage of radiolabeled substance during inflation was similar in both groups, 6%+/-12% (mean +/- SD) from the forearm and 10%+/-20% from the upper arm. After deflation, mean loss of radioactivity was higher in conventional IVRA, 70%+/-7% vs 57%+/-11% and 82%+/-5% vs 69%+/-11% at 3 and 20 min, respectively (P < 0.001). We conclude that forearm IVRA results in tourniquet leakage comparable to conventional IVRA and is potentially safer because the required dose of local anesthetic is smaller. IMPLICATIONS: Using a tourniquet on the forearm for IV regional anesthesia does not increase the risk of drug leakage. This is potentially a safer technique compared with conventional IV regional anesthesia because a much smaller dose of local anesthetic is required.

Initial and long-term results with the CrossFlex stent--data from a national registry.

The Cordis CrossFlex trade mark stent is a balloon expandable helical coil made of stainless steel. OBJECTIVE: To assess the short- and long-term safety and efficacy of this stent by conducting a multi-center national registry. METHODS: One hundred and sixteen stents were implanted in 109 patients (mean age 59 3 10 years, 95 males). The lesions were classified as type B2 or C in 56 patients (51%). Successful deployment was achieved in 103 patients (94.5%). Failure was due to damage to the stent (two patients) or inability to reach the lesion (four patients). High-pressure deployment (>14 atm) was used in 68% of cases. RESULTS: Edge dissections occurred in nine patients after high-pressure deployment and necessitated implantation of a second stent. One patient with a large acute myocardial infarction died during hospitalization. Side branch occlusion occurred in five patients (4.6%). Subacute thrombosis occurred in two patients (1.8%) during the first four weeks. During a six-month follow-up period, 18 patients (16.5%) were rehospitalized with recurrent angina. Fifteen patients had coronary angiography and 13 (12.1%) needed additional target lesion revascularization (TLR). Twelve patients required a second PTCA for in-stent restenosis, and one needed a coronary artery bypass graft operation. CONCLUSIONS: The CrossFlex coronary stent can successfully be used in complex coronary lesions, with few short-term complications and a low TLR rate. Operators should be aware of the possibility of edge dissection during high-pressure implantation.

When to use bone scintigraphy. It can reveal things other studies cannot.

Despite advances in nuclear medicine, bone scintigraphy remains an important imaging technique. It is sensitive in detecting stress fractures and bone metastases and can assess suspected injury that is difficult to see on plain films (e.g., rib fracture). Scintigraphy is useful in evaluating new symptoms, response to therapy, and prognosis in patients with known malignant tumor. In patients with low back pain, the technique can determine the age of fractures to help identify osteoporosis and can uncover other causes of the pain (e.g., spondylolysis, arthritis). When Paget's disease is suggested by unexplained bone pain or an elevated serum alkaline phosphatase level, bone scintigraphy is a useful screening test. Combined with other appropriate nuclear medicine studies, it helps in early identification and localization of osteomyelitis. Scintigraphic scans can provide a general indicator of malignant versus benign disease (according to the amount of lesion activity seen) and may produce characteristic findings in certain primary tumors (e.g., osteoid osteoma) that are difficult to evaluate with other methods.

[Emergency stenting for acute left main coronary artery closure during cardiac catheterization].

We report a case of acute closure of the left main coronary artery, a rare complication of diagnostic cardiac catheterization, treated by emergency stenting prior to aorto-coronary bypass surgery. We suggest encroachment of the Judkins catheter into a calcified left main ostium; with dissection and acute thrombosis of this segment, as the possible mechanism. Clinically, the patient's condition deteriorated to cardiogenic shock and loss of consciousness. Remarkably, there was no angiographic evidence of significant left main coronary artery disease, besides the presence of calcification in the proximal part of the left coronary system and ventricularization of coronary pressure at the time of engagement. We chose to slide quickly the angioplasty guidewire through the left main coronary artery, which allowed prompt mechanical recanalization and rapid restoration of coronary flow, with dramatic clinical and hemodynamic improvement. This relatively simple procedure allowed stenting the left main artery after brief predilation, and the patient came to by-pass surgery in excellent condition. The rationale for surgery in this case was the need for complete coronary revascularization because of significant 3-vessel coronary artery disease.

Patients with symptomatic ischemia have larger thallium perfusion abnormalities and more adverse prognosis than patients with silent ischemia.

OBJECTIVE: To evaluate the mechanism for silent ischemia and the effect on prognosis. DESIGN: To test the hypothesis that patients with silent (compared with symptomatic) ischemia have less severe ischemia and a more favorable prognosis, the authors prospectively evaluated 152 consecutive patients with a positive exercise electrocardiogram with exercise thallium scintigraphy and followed them for two years. SETTING: Tertiary care university-based hospital. RESULTS: Asymptomatic patients during the exercise test had a greater exercise duration (9.4 +/- 3.1 versus 6.3 +/- 2.5 mins, P < 0.01), maximal heart rate (155 +/- 20 versus 136 +/- 20 beats/min, P < 0.01), systolic blood pressure (184 +/- 21 versus 176 +/- 23 mmHg, P < 0.05) and double product than patients who were symptomatic with chest pain. Although there was no difference in the magnitude of ST depression, time to ST depression was greater in the asymptomatic (5.6 +/- 2.7 mins), compared with symptomatic (4.6 +/- 2.6 mins), group (P < 0.01). Thallium ischemic score was smaller during asymptomatic ischemia (2.1 +/- 2.7) compared with symptomatic ischemia (3.9 +/- 3.1, P < 0.01). These findings were also demonstrated in a subgroup of 107 patients with both a positive exercise electrocardiogram and positive thallium scan. The patients with asymptomatic ischemia had a two-year cardiac event rate of 5.1% compared with 13.8% in the symptomatic patients (P = 0.065). CONCLUSIONS: Patients with asymptomatic ischemia have less severe myocardial ischemia and a better prognosis than patients with symptomatic myocardial ischemia during exercise testing.

A right atrial mass in the presence of a permanent pacemaker electrode in a patient with polycythemia vera.

A case of a huge right atrial mass that developed 2 years after a permanent pacemaker implantation is described. The patient had a history of polycythemia vera, which is known to present a high tendency towards the development of thrombosis. In light of this fact, we suggest that in similar cases a full echocardiography follow-up should be performed, and long-term anticoagulant therapy should be considered in selected cases.

Preoperative magnetic resonance imaging in Marfan syndrome.

We report one of the first cases in Israel of composite-graft repair of an aortic aneurysm in Marfan syndrome, in which preoperative evaluation was done noninvasively using magnetic resonance imaging (MRI). Because of the relatively favorable outcome of surgical compared with medical treatment of aortic aneurysm in patients with Marfan syndrome, surgery is now more frequently considered, even in asymptomatic patients. MRI is an excellent diagnostic tool for evaluating the thoracic aorta and has been suggested as a replacement for preoperative cardiac catheterization. In the case presented here, MRI preoperative confirmation of a 6.0-cm aortic aneurysm in an asymptomatic 38-year-old man with Marfan syndrome, was followed by composite ascending aorta and aortic valve replacement. The postoperative course was good. This case supports the view that aortic aneurysm replacement can be performed based on a noninvasive preoperative evaluation using MRI.