bluuebunny/crossref_metadata_2025 huggingface dataset:
Functional Consequences of an Integration of Motion and Stereopsis in Area MT of Monkey Extrastriate Visual Cortex
Authors: Lappe Markus
Published: April 2008

Experimental evidence from neurophysiological recordings in the middle temporal (MT) area of the macaque monkey suggests that motion-selective cells can use disparity information to separate motion signals that originate from different depths. This finding of a cross-talk between different visual channels has implications for the understanding of the processing of motion in the primate visual system and especially for behavioral tasks requiring the determination of global motion. In this paper, the consequences for the analysis of optic flow fields are explored. A network model is presented that effectively uses the disparity sensitivity of MT-like neurons for the reduction of noise in optic flow fields. Simulations reproduce the recent psychophysical finding that the robustness of the human optic flow processing system is improved by stereoscopic depth information, but that the use of this information depends on the structure of the visual environment.
Using Visual Latencies to Improve Image Segmentation
Authors: Opara Ralf , Wörgötter Florentin
Published: April 2008

An artificial neural network model is proposed that combines several aspects taken from physiological observations (oscillations, synchronizations) with a visual latency mechanism in order to achieve an improved analysis of visual scenes. The network consists of two parts. In the lower layers that contain no lateral connections the propagation velocity of the activity of the units depends on the contrast of the individual objects in the scene. In the upper layers lateral connections are used to achieve synchronization between corresponding image parts. This architecture assures that the activity that arises in response to a scene containing objects with different contrast is spread out over several layers in the network. Thereby adjacent objects with different contrast will be separated and synchronization occurs in the upper layers without mutual disturbance between different objects. A comparison with a one-layer network shows that synchronization in the latency dependent multilayer net is indeed achieved much faster as soon as more than five objects have to be recognized. In addition, it is shown that the network is highly robust against noise in the stimuli or variations in the propagation delays (latencies), respectively. For a consistent analysis of a visual scene the different features of an individual object have to be recognized as belonging together and separated from other objects. This study shows that temporal differences, naturally introduced by stimulus latencies in every biological sensory system, can strongly improve the performance and allow for an analysis of more complex scenes.
On the Capacity of Threshold Adalines with Limited-Precision Weights
Authors: Stevenson Maryhelen , Huq Shaheedul
Published: April 2008

The effect of limited-precision weights on the capacity of the threshold Adaline is examined. In particular, an experimental technique is used to determine the capacity of the threshold Adaline for several different levels of weight precision. The results provide some insight into the manner in which the capacity of the threshold Adaline increases as the number of bits per weight increases. As might be expected, the growth in capacity due to an additional bit per weight is greatest when the original number of bits per weight is small, and decreases as the original number of bits per weight increases.
What Matters in Neuronal Locking?
Authors: Gerstner Wulfram , van Hemmen J. Leo , Cowan Jack D.
Published: April 2008

Exploiting local stability, we show what neuronal characteristics are essential to ensure that coherent oscillations are asymptotically stable in a spatially homogeneous network of spiking neurons. Under standard conditions, a necessary and, in the limit of a large number of interacting neighbors, also sufficient condition is that the postsynaptic potential is increasing in time as the neurons fire. If the postsynaptic potential is decreasing, oscillations are bound to be unstable. This is a kind of locking theorem and boils down to a subtle interplay of axonal delays, postsynaptic potentials, and refractory behavior. The theorem also allows for mixtures of excitatory and inhibitory interactions. On the basis of the locking theorem, we present a simple geometric method to verify the existence and local stability of a coherent oscillation.
Hebbian Learning of Context in Recurrent Neural Networks
Authors: Brunel Nicolas
Published: April 2008

Single electrode recordings in the inferotemporal cortex of monkeys during delayed visual memory tasks provide evidence for attractor dynamics in the observed region. The persistent elevated delay activities could be internal representations of features of the learned visual stimuli shown to the monkey during training. When uncorrelated stimuli are presented during training in a fixed sequence, these experiments display significant correlations between the internal representations. Recently a simple model of attractor neural network has reproduced quantitatively the measured correlations. An underlying assumption of the model is that the synaptic matrix formed during the training phase contains in its efficacies information about the contiguity of persistent stimuli in the training sequence. We present here a simple unsupervised learning dynamics that produces such a synaptic matrix if sequences of stimuli are repeatedly presented to the network at fixed order. The resulting matrix is then shown to convert temporal correlations during training into spatial correlations between attractors. The scenario is that, in the presence of selective delay activity, at the presentation of each stimulus, the activity distribution in the neural assembly contains information of both the current stimulus and the previous one (carried by the attractor). Thus the recurrent synaptic matrix can code not only for each of the stimuli presented to the network but also for their context. We combine the idea that for learning to be effective, synaptic modification should be stochastic, with the fact that attractors provide learnable information about two consecutive stimuli. We calculate explicitly the probability distribution of synaptic efficacies as a function of training protocol, that is, the order in which stimuli are presented to the network. We then solve for the dynamics of a network composed of integrate-and-fire excitatory and inhibitory neurons with a matrix of synaptic collaterals resulting from the learning dynamics.

The network has a stable spontaneous activity, and stable delay activity develops after a critical learning stage. The availability of a learning dynamics makes possible a number of experimental predictions for the dependence of the delay activity distributions and the correlations between them, on the learning stage and the learning protocol. In particular it makes specific predictions for pair-associates delay experiments.
Neural Correlation via Random Connections
Authors: Chover Joshua
Published: April 2008

A simple neural network is studied, which has sparse, random, plastic, excitatory connections and also feedback loops between sensory cells and correlator cells. Time is limited to several discrete instants, where firing is synchronous. For parameter values within biological ranges, the system exhibits a capacity for associative recall, with a controlled amount of extraneous firing, following Hebb-like synaptic changes.
Autonomous Design of Artificial Neural Networks by Neurex
Authors: Michaud François , Rubio Ruben Gonzalez
Published: April 2008

Artificial neural networks (ANN) have been demonstrated to be increasingly more useful for complex problems difficult to solve with conventional methods. With their learning abilities, they avoid having to develop a mathematical model or acquiring the appropriate knowledge to solve a task. The difficulty now lies in the ANN design process. A lot of choices must be made to design an ANN, and there are no available design rules to make these choices directly for a particular problem. Therefore, the design of an ANN demands a certain number of iterations, mainly guided by the expertise and the intuition of the developer. To automate the ANN design process, we have developed Neurex, composed of an expert system and an ANN simulator. Neurex autonomously guides the iterative ANN design process. Its structure tries to reproduce the design steps done by a human expert in conceiving an ANN. As a whole, the Neurex structure serves as a framework to implement this expertise for different learning paradigms. This article presents the system's general characteristics and its use in designing ANN using the standard backpropagation learning law.
Intracoronary Administration of Isosorbide Dinitrate Induced Severely Slow Flow and Transient ST-Segment Elevation
Authors: Yamashita Kazuhito , Tasaki Hiromi
Published: April 2008

Nitroglycerin is one of the most widely used drugs in the treatment of angina. However, nitroglycerin fails to relieve angina in patients with syndrome X who have microvessel dysfunction. Microvessel function is impaired in several diseases. In this article, the authors report that despite normal coronary angiograms at control, intracoronary administration of isosorbide dinitrate induced severe coronary slow flow and transient ST-segment elevation with mild chest pain in a patient with congestive heart failure. The authors speculated that functional stenosis and a delay in the dilatation of microvessels less than 100 µm in diameter because of their dysfunction resulted in a severely slow flow after intracoronary administration of isosorbide dinitrate.
The Roles of Oxidized Low-Density Lipoprotein and Interleukin-6 Levels in Acute Atherothrombotic and Lacunar Ischemic Stroke
Authors: Guldiken Baburhan , Guldiken Sibel , Turgut Burhan , Turgut Nilda , Demir Muzaffer , Celik Yahya , Arikan Ender , Tugrul Armagan
Published: April 2008

The role of circulating, oxidized low-density lipoprotein and interleukin-6 levels in acute ischemic stroke considering the primary-vessel disease was investigated. The study consisted of 28 patients with acute ischemic stroke and 23 control subjects. Patients were subdivided into large-vessel (n = 12) and small-vessel (n =16) disease stroke groups according to the Trial of Org 10172 in Acute Stroke Treatment (TOAST) criteria. The means of oxidized low-density lipoprotein and interleukin-6 levels of patients with acute ischemic stroke were higher than controls ( P < .01, P < .05). Mean oxidized low-density lipoprotein level was higher in the large-vessel disease group than in the small-vessel disease group ( P < .01). The mean of inteleukin-6 levels was higher in the small-vessel disease group ( P < .01). The results of the present study showed that oxidative stress promotes large-vessel disease rather than small-vessel disease stroke, and inflammation may play important an role in the development of small-vessel disease stroke.
Spontaneous Coronary Artery Dissection Mimicking Acute Aortic Dissection
Authors: Seong Hwan Kim  , Kim Min-Kyu , Eung Ju Kim  , Woo Jung Park  , Young Jin Choi  , Chong Yun Rhim
Published: April 2008

Spontaneous coronary artery dissection is a rare cause of acute coronary syndrome or sudden cardiac death, occurring predominantly in the female sex without cardiovascular risk factors. Although the etiology and pathogenesis remain uncertain, hypertension has not appeared to be one of the most important factors. This case report describes a patient with spontaneous coronary artery dissection in proximal Right coronary artery who presented the signs and symptoms of acute aortic dissection. The authors postulate that hypertension may have been an important factor for the pathogenesis of the spontaneous coronary artery dissection.
Thienopyridine Therapy Influences Late Outcome After Coronary Stent Implantation
Authors: Aradi Dániel , Kónyi Attila , Pálinkás László , Berki Tímea , Pintér Tünde , Tahin Tamás , Horváth Iván , Papp Lajos , Komócsi András
Published: April 2008

Clinical significance of resistance to aspirin and thienopyridine therapy is poorly defined. The authors aimed to evaluate whether more effective antiplatelet therapy is associated with better outcome in patients on dual-antiplatelet treatment. Using optical aggregometer, maximal platelet aggregation values were measured with induction of adenosine diphosphate, collagen, and adrenaline 30 ± 5 days after coronary stent implantation in 134 patients. Markers of platelet activation were also analyzed with fluorescent immunoassay in 57 patients. After 10 months of follow-up, 33 patients reached the composite endpoint of cardiovascular death, myocardial infarction, and revascularisation. Adenosine diphosphate-induced maximal aggregation values were in significant relationship with the development of major adverse cardiac events ( P < .01). Level of soluble P-selectin proved to be an independent risk factor of adverse outcome ( P < .05). As efficacy of thienopyridine therapy showed significant relation with clinical outcome, the authors conclude that interindividual variability in response to adenosine diphosphate-receptor antagonists may be of substantial clinical importance.
Percutaneous Thrombin Injection for Treatment of Iatrogenic Femoral Artery Pseudoaneurysms: A Case for Caution
Authors: Ohlow Marc-Alexander , Secknus Maria-Anna , von Korn Hubertus , Weiss Reginald , Lauer Bernward
Published: April 2008

The case of a patient who developed a femoral artery pseudoaneurysm following cardiac catheterization is described. After 2 failed attempts of ultrasound-guided compression repair, the patient underwent percutaneous thrombin injection with, beside of complete closure of the pseudoaneurysm, a severe limb ischemia due to distal thrombin migration with consecutive clot formation finally resulting in thigh amputation of the affected leg. Indications, advantages, and disadvantages of various options for the treatment of iatrogenic femoral artery pseudoaneurysms (vascular surgery, ultrasound-guided compression, percutaneous thrombin injection, and other nonsurgical treatment modalities), as well as risk factors for distal migration of liquid thrombin after percutaneous injection, are discussed in this report.
Hierarchical Analysis of Cardiovascular Risk Factors in Relation to the Development of Acute Coronary Syndromes, in Different Parts of Greece: The CARDIO2000 Study
Authors: Panagiotakos Demosthenes B. , Pitsavos Christos , Chrysohoou Christine , Stefanadis Christodoulos
Published: April 2008

During 2000 to 2002, 700 men (59 ± 10 years) and 148 women (65 ± 9 years) patients with first event of an ACS were randomly selected from cardiology clinics of Greek regions. Afterwards, 1078 population-based, age-matched and sex-matched controls were randomly selected from the same hospitals. The frequency ratio between men and women in the case series of patients was about 4:1, in both south and north Greek areas. Hierarchical classification analysis showed that for north Greek areas family history of coronary heart disease, hypercholesterolemia, hypertension, diabetes (explained variability 35%), and less significantly, dietary habits, smoking, body mass index, and physical activity status (explained variability 4%) were associated with the development of ACS, whereas for south Greek areas hypercholesterolemia, family history of coronary heart disease, diabetes, smoking, hypertension, dietary habits, physical activity (explained variability 34%), and less significantly body mass index (explained variability <1%), were associated with the development of the disease.
Comparison of Monotherapy Versus Combination Antihypertensive Therapy in Elderly Patients With Essential Hypertension
Authors: Antonopoulos Stavros , Kokkoris Stelios , Gerakari Styliani , Mikros Sotirios , Nitsotolis Thomas , Vikeli Despina , Korantzopoulos Panagiotis , Giannoulis Gregory
Published: April 2008

Authors sought to compare the efficacy of monotherapy versus combination antihypertensive therapy in elderly patients. Patients in this study, aged 65 to 85 years, were divided into 4 groups and entered an 8-week treatment period. First group: 22 patients, amlodipine 5 mg/d increasing to 10 mg; second: 20 patients, eprosartan 600 mg/d increasing to 600 mg twice a day; third: 21 patients, amlodipine 5 mg/d and indapamide 2.5 mg/d, increasing amlodipine to 10 mg/d; fourth: 23 patients, imidapril 10 mg/d and indapamide 2.5 mg/d, imidapril doubled to 20 mg/d. A greater drop in systolic and in diastolic blood pressure was obtained by combination of amlodipine and indapamide compared with amlodipine or eprosartan monotherapy. Imidapril and indapamide showed similar efficacy compared with eprosartan monotherapy but not with amlodipine monotherapy. Amlodipine and indapamide appeared more effective than imidapril and indapamide in diastolic blood pressure. Combination treatment with amlodipine and indapamide or imidapril and indapamide effectively reduces blood pressure in elderly patients with essential hypertension.
Prevalence of Metabolic Syndrome in Patients With Clinically Advanced Peripheral Vascular Disease
Authors: Qadan Laila R. , Ahmed Adel A. , Safar Hussein A. , Al-Bader Marzouk A. , Ali Amr A.
Published: April 2008

The aim of this cross-sectional study was to determine the prevalence of metabolic syndrome (MetS) and its components among 100 patients with progressive peripheral arterial disease (PAD) referred for diagnostic angiography in preparation for a revascularization procedure. The prevalence of MetS was more than 95%. Diabetes mellitus was the most prevalent component followed by hypertension and low high-density lipoprotein. Almost half the patients aggregated in the highest metabolic score category. A direct relationship was identified between the number of MetS components and serum uric acid ( P = .001) and C-reactive protein ( P = .826), whereas an inverse relationship was seen between the clustering of components and androgen levels in men ( P < .001). For PAD, which could have a benign clinical course, early screening for MetS might identify those at greater risk of failing conservative therapy and progressing to a more aggressive atherosclerotic disease typically associated with high morbidity and mortality.
Endovascular Embolization of Intracranial Aneurysms
Authors: Guan Yong-Song , Wang Ming-Quan
Published: April 2008

Intracranial aneurysm (ICA) is a common condition but with a high mortality rate when rupture occurs. The treatment of ruptured or unruptured ICA, especially with an endovascular approach, has been evolving rapidly. The current generally accepted opinion suggests that endovascular embolization is an effective technique for preventing the recurrence of aneurysm rupture, but the rebleeding rate after endovascular embolization is found to be higher than that after surgical clipping. In addition, long-term follow-up data are required for the evaluation of the effectiveness of endovascular treatment in unruptured ICA. This review presents the current understanding of ICA, the selection of optimal treatment approaches, and in particular, the advances in endovascular embolization in the treatment of ICA, including embolic materials, therapeutic and assisting techniques, long-term effectiveness, and limitations.
Acute Myocardial Infarction in a Young Man Using Anabolic Steroids
Authors: Wysoczanski Mariusz , Rachko Maurice , Bergmann Steven R.
Published: April 2008

Anabolic-androgenic steroids are used worldwide to help athletes gain muscle mass and strength. Their use and abuse is associated with numerous side effects, including acute myocardial infarction (MI). We report a case of MI in a young 31-year-old bodybuilder. Because of the serious cardiovascular complications of anabolic steroids, physicians should be aware of their abuse and consequences.
Inferior Vena Cava Agenesia and a Massive Bilateral Iliofemoral Venous Thrombosis
Authors: Vucicevic Zeljko , Degoricija Vesna , Alfirevic Zrinka , Sharma Mirella
Published: April 2008

The absence of the inferior vena cava is a rare congenital anomaly and represents a modest risk for deep-venous thrombosis. When associated with genetic polymorphism or other hypercoagulable states, the risk can increase several times. A case of young man with the inferior vena cava agenesia and deep-venous thrombosis of both legs triggered by the physical effort is reported. The view that the congenital inferior vena cava malformation represents a predisposition to deep-venous thrombosis in spite of well-developed collateral circulation is supported. In these circumstances, various external triggers (physical effort, hormonal contraception etc) may precipitate thrombosis. Because the patient had no other convincing and permanent risk factors for thrombosis, the lifelong anticoagulant therapy was not recommended.
Splenic Vein Thrombosis Following Abdominal Compression and Vibration: A Case Report
Authors: Tzur Irma , Almoznino-Sarafian Dorit , Dotan Eynat , Copel Laurian , Gorelik Oleg , Shteinshnaider Miriam , Cohen Natan
Published: April 2008

The authors describe a 46-year-old man with isolated splenic vein thrombosis (SVT) that developed after concrete drilling, which caused significant compression and vibration of the abdominal wall. Methyltetrahydrofolate reductase (MTHFR) deficiency-related hyperhomocysteinemia, which was subsequently diagnosed, predisposed him to this event. To the best of the knowledge of authors, this is the first report of isolated splenic vein thrombosis caused by compression and vibration of the abdomen. Relevant aspects of isolated post-traumatic splenic vein thrombosis in this context are discussed.
Randomized, Double Blind, Placebo-Controlled Clinical Trial to Evaluate the Lymphagogue Effect and Clinical Efficacy of Calcium Dobesilate in Chronic Venous Disease
Authors: Flota-Cervera Fernando , Flota-Ruiz Cintia , Treviño Carlos , Berber Arturo
Published: April 2008

The aims of the present study were to investigate the effect of calcium dobesilate on lymph flow and lymphovenous edema in patients with chronic venous disease. It was a randomized, placebo-controlled, double-blind clinical trial. Patients received 1 capsule of 500 mg calcium dobesilate every 8 hours (1.5 g/day) or placebo by 49 days. By the end of the treatment period, only the patients treated with calcium dobesilate had normalization of lymphogammagraphy (capture index and speed of lymph flow; 80 and 78%, respectively). Only patients treated with calcium dobesilate had statistically significant reduction in the perimeter of leg, calf, and ankle. Twenty-two out of 25 (88%) calcium dobesilate—treated patients presented clinical improvement versus 5 out of 24 (20.8%) in the placebo group. One patient on calcium dobesilate developed rash and one patient on placebo complained of vomiting. In the present study, calcium dobesilate normalized lymph physiology and improved symptoms in patients with chronic venous disease.
Anterior ST-Segment Elevation With Right Coronary Artery Occlusion: A Unique Case of Isolated Right Ventricular Infarction
Authors: Muhammad Kamran I. , Kapadia Samir R.
Published: April 2008

Anterior ST-segment elevation is the classic electrocardiographic feature of anterior left ventricular myocardial infarction due to occlusion of the left anterior descending artery. However, anterior ST-segment elevation has also been described in patients with right coronary artery occlusion, in whom concomitant inferior ST-segment elevation is also typically present. A case of proximal right coronary artery occlusion resulting in anterior ST-segment elevation without inferior ST-segment elevation is reported in this article. It is hypothesized that the inferior left ventricular wall was protected by left-to-right collaterals, as seen on coronary angiography, with resultant isolated right ventricular infarction upon proximal right coronary artery occlusion. In conclusion, this report presents a unique case of an isolated right ventricular infarction resulting in an electrocardiographic pattern mimicking anterior-wall left ventricular infarction.
Acute Posttraumatic Ischemia of the Limbs: Algodystrophy or Related Syndrome? A Prospective Study on a Series of 25 Patients
Authors: Pistorius Marc-Antoine , Connault Jérôme , Kalassy Chady , Goueffic Yann , Planchon Bernard
Published: April 2008

The aim of this study was to present clinical and paraclinical features of a rarely studied vascular syndrome that usually occurs after a minor traumatic injury. The prospective study of 25 patients identified a group of young subjects, mainly women, generally with history of vascular hyperactivity to cold, showing disseminated pain in a limb always combined with vasospasm, consecutive to a minor traumatic injury in general, and simulating acute ischemia of a limb. The patients' arterial and microcirculatory flows were restored after warming, which proved that they were suffering from intense, reversible but pathological vasospasm, because of its duration, diffusion, intensity, and disproportion as to the triggering event. The symptoms may recur, but they respond to physiotherapy. Patients' follow-up showed that microcirculatory function remains abnormal sometime after the initial episode with, in particular, an exacerbation of the venoarteriolar reflex.
Management of Primary Pulmonary Artery Sarcoma: Experience of a Single Center
Authors: Fernández-Golfín Covadonga , Escribano Pilar , Cortina José , Tello Rocío , Hernández Felipe , López-Rios Fernando , Delgado Jiménez Juan , Saenz de la Calzada Carlos
Published: April 2008

Primary sarcoma of the pulmonary artery (PSPA) is extremely rare. Many cases are misdiagnosed as pulmonary arterial hypertension (PAH) because of chronic thromboembolic disease (CTD). Four cases of PSPA with the initial misdiagnosis are reported. The presence of a unique mass in the main pulmonary artery or proximal branches, rapidly progressive dyspnea, and constitutional symptoms should raise the suspicion of PSPA. The pathological diagnosis is usually confirmed during surgery, which is done along with adjuvant chemotherapy, the treatment of choice.
Endothelial Dysfunction in Chronic Obstructive Pulmonary Disease
Authors: Moro Leo , Pedone Claudio , Scarlata Simone , Malafarina Vincenzo , Fimognari Filippo , Antonelli-Incalzi Raffaele
Published: April 2008

Background: Cardiovascular diseases are prevalent in people with chronic obstructive pulmonary disease (COPD). We hypothesized that endothelial dysfunction could be a marker of the proatherogen status in COPD. Methods and results: We measured endothelial dysfunction by flow-mediated dilation (FMD) and after sublingual administration of nitroglycerin (nitrate-mediated dilation: NMD) in 44 COPD patients and 48 controls. Compared with controls COPD patients had worse mean FMD (5.4% vs 8.2%, P < .001) and NMD (12.0% vs 13.9%, P = .007). FMD was inversely related to FEV1/VC ratio ( r = −0.327, P = .030). The negative association between COPD and FMD was confirmed after correction for potential confounders in a multiple linear regression model (β = −0.019, P = .002). In the same model NMD (β = 0.396, P < .001) was positively associated with FMD. Conclusions: Endothelial-dependent and, to a lesser extent, endothelial-independent dilations are significantly impaired in COPD, and the impairment is proportional to the severity of bronchial obstruction.
Lipid-Lowering Therapy is Related to Inflammatory Markers and 3-Year Mortality in Patients With Critical Limb Ischemia
Authors: Isma Nazim , Barani Jamal , Mattiasson Ingrid , Lindblad Bengt , Gottsäter Anders
Published: April 2008

To evaluate relationships between lipid-lowering therapy, inflammation, and 3-year mortality in critical limb ischemia (CLI), 259 consecutive CLI patients underwent evaluation of medication, tumor necrosis factor-α, interleukin-6 (IL-6), neopterin, high-sensitivity C-reactive protein (hs-CRP), 8-epi-PGF2 α, and endothelin-1. Mortality was assessed after 3 years. Sixty-one patients (24%) were on lipid-lowering therapy and 59 patients (97%) on statins. Patients on lipid-lowering therapy were younger and showed lower low-density lipoprotein cholesterol, hs-CRP, and IL-6 levels than patients without therapy. Three-year survival was higher among patients on lipid-lowering therapy. In logistic regression, the effect of lipid-lowering therapy on 3-year survival was significant with inflammatory markers entered into the model one by one but disappeared when all inflammatory markers were entered into the model together. In conclusion, hs-CRP and IL-6 levels were lower and 3-year survival was higher in CLI patients on lipid-lowering therapy.
Racial Differences in Coronary Artery Lesions: A Comparison of Coronary Artery Lesions Between Mainland Chinese and Australian Patients
Authors: Jiang Shi-sen , Lv Lei , Juergens Crag P. , Chen Shao-liang , Xu Dong-jin , Huang Zhe-yong
Published: April 2008

Aims: The purpose of this study was to compare coronary lesions in mainland Chinese and Australians using coronary angiography (CAG). Methods and results: 6251 suspected coronary heart disease (CHD) patients (3021 Chinese patients from Nanjing and 3230 Australian patients from Sydney) who underwent a CAG between January 1, 2001, and December 31, 2003, were studied. Of these, 69.4% Chinese and 75.5% Australians were diagnosed with CHD. The incidences of both left main coronary artery (LM) and left anterior descending branch (LAD) lesions in Australians were higher than that for Chinese of the same gender. In the same age range, above 40, Gensini scores of Australians were significantly higher than those of Chinese. Conclusion: In both Chinese and Australians, men had more severe coronary lesions than women. Comparison among different age ranges in the 2 ethnic groups shows that Australians typically have artery lesions more than 10 years earlier than mainland Chinese.
Late Presentation of a Lead Perforation as a Complication of Permanent Pacemaker Insertion
Authors: Haq Salman A. , Heitner John F. , Lee Leonard , Kassotis John T.
Published: April 2008

Lead perforation is a less-recognized delayed complication of device implantation. Delay in recognition may prove fatal. Predictors of postimplantation pericardial effusion, which serves as a marker of perforation, include concomitant use of transvenous pacemaker, steroid use within 7 days, and older age. The authors report a case of an 86-year-old patient who presented with a lead perforation 16 months following the original pacemaker insertion. Following surgical repair with sternotomy, a new ventricular lead was placed via a transvenous approach at the right ventricular septum. A higher clinical suspicion should be maintained in the elderly in whom perforation occurs more frequently, and consideration should be given to implanting the lead in sites other than the right ventricular apex to minimize the risk of this late complication.
Progression of Nonculprit Plaque Stenosis Following Successful Percutaneous Intervention
Authors: Bunch T. Jared , Rihal Charanjit S. , Gumina Richard J. , Cooper Leslie , Caplice Noel M.
Published: April 2008

Despite percutaneous intervention after an acute coronary syndrome, patients remain at high risk for recurrent events in the first year. Prior studies have shown that a plaque rupture can occur not only at a single culprit lesion site but also in other atherosclerotic plaques throughout the coronary vasculature in patients with stable angina, silent myocardial ischemia, and during acute coronary syndromes. A 71-year-old man who presented with exertional angina and who had a successful stent in a culprit right coronary artery is described in this article. After 4 weeks, he represented with accelerated angina. A prior lesion in the obtuse marginal artery, remote from the site of the index lesion, had progressed from a 30% to 90% stenosis. This case report demonstrates the systemic nature of acute coronary syndromes, highlights the inherent instability of coronary artery disease, and supports the notion of aggressive secondary prevention in these patients.
Effects of Policosanol (10 mg/d) Versus Aspirin (100 mg/d) in Patients With Intermittent Claudication: A 10-Week, Randomized, Comparative Study
Authors: Illnait José , Castaño Gladys , Alvarez Ernesto , Fernández Lilia , Mas Rosa , Mendoza Sarahí , Gamez Rafael
Published: April 2008

Antiplatelet therapy, including aspirin, is recommended to lower the vascular risk in patients with intermittent claudication. Policosanol has increased walking distances in these patients, probably because of its antiplatelet effects, but the effect of shorter treatment has not been studied. This double-blind study compared the effects of policosanol 10 mg/d and aspirin 100 mg/d for 10 weeks on walking distances in claudicants. Thirty-nine patients were randomized to policosanol or aspirin. Walking distances on a treadmill were assessed before and after treatment. Policosanol significantly increased the initial and absolute claudication distances, while aspirin changed neither variable. Policosanol, not aspirin, significantly lowered serum low-density lipoprotein-cholesterol and total cholesterol while raising high-density lipoprotein-cholesterol. In conclusion, treatments of policosanol, not aspirin, for 10 weeks significantly increased walking distances, but modestly, in contrast with previous results. Therefore, the duration of treatments at the doses tested was too short for meaningful effects on the treadmill test.
Surrogate Markers for Atherosclerosis in Overweight Subjects With Atherogenic Dyslipidemia: The GEMS Project
Authors: Genoud Myriam , Wietlisbach Vincent , Feihl François , Mermod Alice , Morin Diane , Darioli Roger , Nicod Pascal , Mooser Vincent , Waeber Bernard , Hayoz Daniel , Waeber Gérard
Published: April 2008

Metabolic syndrome is a constellation of major risk factors for cardiovascular disease. In affected individuals with this syndrome, the independent contribution of low high-density lipoprotein—cholesterol and increased triglyceride levels to the development of atherosclerosis remains to be clarified. We assessed the relationship between these 2 parameters and several surrogate markers for atherosclerosis. One hundred and twenty overweight cases, defined as having high-density lipoprotein—cholesterol (≤25 age- and gender-specific percentile in general population) and high triglyceride values (≥75 percentile) were compared with 120 discordant overweight controls defined on lipid values (high-density lipoprotein—cholesterol ≥50 percentile and triglycerides ≤50 percentile). Case-control pairs were matched for age and gender. Carotid and femoral arteries were examined to determine carotid intima-media thickness and the presence of atherosclerotic plaque(s). Endothelial function was assessed by laser Doppler flowmetry in the skin microvasculature. Daytime ambulatory blood pressure monitoring was performed for each subject. Cases had higher prevalence of atherosclerotic plaques (mean 1.50 ± 0.15 vs 0.80 ± 0.15, P < .001), increased carotid intima-media thickness (mean 0.66 ± 0.15 vs 0.61 ± 0.15, P < .01), and a significantly reduced temperature-induced and postischemic endothelial vasodilation compared with controls. In conclusion, low high-density lipoprotein—cholesterol and high triglycerides levels are major contributors to peripheral atherosclerosis and are associated with an increase in intima-media thickness and impaired microvascular endothelial function in overweight individuals.
Brachial Artery Flow-Mediated Vasodilation in Patients With Cardiac Syndrome X
Authors: Li Ai-Hsien , Lee Bai-Chin , Chen Kuo-Chin , Weng Ching-Sung , Chu Shu-Hsun
Published: April 2008

Cardiac syndrome X (CSX) differs from coronary artery disease (CAD) and is characterized by angina, positive stress test, and patent coronary arteries. The probable mechanism is a microvascular disorder associated with endothelial dysfunction. In this study, brachial artery flow-mediated vasodilation was used as well as the endothelin-1 assay to assess endothelial function in patients with cardiac syndrome X (CSX), coronary artery disease (CAD), and healthy controls. All subjects underwent a 2-step brachial artery flow-related vasodilatation test. Serum endothelin-1, one of the most potent constricting factors, was measured for all participants. Patients with CSX had a lower brachial artery dilation ratio than controls but higher than that of CAD patients. Control subjects and CSX patients had higher endothelin-1 levels than CAD patients. CSX patients were found to have worse endothelial function than healthy volunteers, but patients with CAD had even worse endothelium function than CSX patients.
Potential Pitfalls of Renal Angiography: A Case of Atypical Fibromuscular Dysplasia
Authors: Pratap T. , Sloand James A. , Narins Craig R.
Published: April 2008

Although angiography remains the gold standard for the diagnosis of renal artery stenosis, renovascular disease can at times present with unusual patterns that may be difficult to detect. The authors present a case in which an initial renal angiogram failed to identify the presence of severe disease involving both a main and accessory renal artery. Repeat angiography coupled with the use of adjunctive catheter-based techniques including translesional pressure gradient determination and intravascular ultrasound with virtual histology imaging revealed the presence of atypical fibromuscular dysplasia that was treated with good clinical results. The case highlights the importance of performing careful and complete renal angiography, including imaging of smaller accessory renal arteries, and describes several readily available catheter-based techniques that can be useful in elucidating the physiological significance and etiology of renal artery stenosis.
Rhabdomyolysis following Accidental Intra-arterial Injection of Local Anesthetic
Authors: Selimoglu Ozer , Basaran Murat , Ugurlucan Murat , Ogus Temucin Noyan
Published: April 2008

Drug-induced myopathy, also named Nicolau syndrome, is a well-known phenomenon following intramuscular injection of certain agents, most commonly reported with penicillin or diclofenac. The mechanism responsible for the pathology is proposed to be incidental administration of the drug into the small arterioles. In this report, we present a Nicolau syndrome-like case that developed following accidental injection of a local anesthetic agent into the femoral artery during coronary angiography.
Coronary Collateral Circulation: Any Effect on P-Wave Dispersion?
Authors: Aslan Halil , Turgut Okan , Yalta Kenan , Yilmaz Mehmet B. , Ozdemir Ramazan , Ermis Necip , Sezgin Alpay T. , Yetkin Ertan , Tandogan Izzet , Yilmaz Ahmet
Published: April 2008

Coronary collateral circulation determines the severity of ischemic myocardial damage. Increased P-wave dispersion is an independent predictor for atrial fibrillation. Consistent evidence is little about the relation between coronary collateral circulation and arrhythmia risk. In this article, the effect of coronary collateral circulation on P-wave dispersion was evaluated. Collateral grade and P-wave dispersion were ascertained in 100 patients with ≥85% diameter stenoses in left anterior descending or right coronary arteries. Left ventricular function score was also determined in all patients. Coronary collateral circulation was absent in 32 patients, whereas 68 patients had coronary collateral circulation. Patients with collateral grade ≥1 had greater left ventricular function score than did patients with collateral grade 0 ( P = .048). However, there was no significant difference between P-wave dispersion of patients with and without coronary collateral circulation ( P = .45). The presence of coronary collateral circulation failed to exert a beneficial decreasing effect on P-wave dispersion.
Simultaneous Presentations of Deep Vein Thrombosis and Cerebral Sinus Thrombosis in a Case of Primary Antiphospholipid Syndrome
Authors: Sakamoto Shingo , Akutsu Koichi , Kawase Kayoko , Takada Tatsuro , Seyama Hidenori , Takahashi Jun , Miyamoto Susumu , Nonogi Hiroshi , Takeshita Satoshi
Published: April 2008

Antiphospholipid syndrome is characterized with arterial and venous thrombosis. In this article, a 38-year-old man presented with headache and swelling of his left limb, which had lasted for 2 months. Duplex ultrasonography showed thrombosis of the left femoral vein. Cerebral magnetic resonance imaging also showed cerebral sinus thrombosis. Serological examination showed that antiphospholipid syndrome was the underlying disease condition in this patient. Despite adequate anticoagulant therapy, deep vein thrombosis and cerebral sinus thrombosis exacerbated, resulting in inferior vena cava occlusion, papilloedema, and abducent nerve paralysis. Optic canal decompression and cistern-peritoneal shunt operation were performed, following which his neurological symptoms were relieved. The occurrence of cerebral sinus thrombosis as initial presentation of antiphospholipid syndrome is extremely rare and remains a diagnostic challenge. Although the clinical presentation is highly variable, the diagnosis should be considered in patients with antiphospholipid syndrome presenting with recent unusual headaches. Improved diagnosis and treatment strategy may ultimately improve the clinical outcome of these patients.
Effects of Cilostazol and Pentoxifylline on Forearm Reactive Hyperemia Response, Lipid Profile, Oxidative Stress, and Inflammatory Markers in Patients With Intermittent Claudication
Authors: de Albuquerque Renato Maranhão , Virgini-Magalhães Carlos Eduardo , Lencastre Sicuro Fernando , Bottino Daniel Alexandre , Bouskela Eliete
Published: April 2008

Peripheral arterial disease may lead to lower limb claudication and increased risk of systemic vascular dysfunction. In this article, the authors have investigated the peripheral vascular dysfunction evaluating forearm blood flow using venous occlusion plethysmography, lipid profile, and C-reactive protein in 60 patients with moderate intermittent claudication treated during 20 weeks with placebo (n = 16), cilostazol (200 mg/d; n = 17), or pentoxifylline (1200 mg/d; n = 15) in a randomized double-blinded clinical trial, taking into account smoking. Forearm blood flow after reactive hyperemia response (FBFh ) or oral nitroglycerine spray to evaluate endothelial-dependent and endothelial-independent vasodilation, respectively, pain-free and maximal walking distance, levels of C-reactive protein, triglycerides, cholesterol, low-density lipoprotein, and high-density lipoprotein—cholesterol in plasma were determined. The results showed that there was an improvement in the high-density lipoprotein—cholesterol, pain-free and maximal walking distance, and FBFh independent of treatment in nonsmoking patients. Cilostazol increased high-density lipoprotein—cholesterol level, maximal walking distance, and FBFh, whereas pentoxifylline reduced C-reactive protein level and increased maximal walking distance in total and nonsmoking groups. No treatment was effective in smokers
QT Dispersion and Left Ventricular Hypertrophy in Elderly Hypertensive and Normotensive Patients
Authors: Dimopoulos Stavros , Nicosia Franco , Donati Paolo , Prometti Paola , De Vecchi Massimiliano , Zulli Roberto , Grassi Vittorio
Published: April 2008

Inhomogeneity of ventricular repolarization as detected by QT dispersion may be a potential leading mechanism of sudden death in hypertensive and normotensive (age related) left ventricular hypertrophy. Aim of this study was to investigate QT dispersion, ventricular arrhythmias, and left ventricular mass index in elderly hypertensive and normotensive patients. Study population consisted of 60 consecutive patients (sex: 34 men/26 women; age: 63 ± 11 years) with essential arterial hypertension and 48 age and sex-matched control subjects (24 men/24 women; 64 ± 16 years). Measurements included QTc dispersion, ventricular arrhythmias, and left ventricular hypertrophy. Hypertensive patients had greater left ventricular mass index ( P = .006) and higher QTc dispersion ( P = .004) than controls. Left ventricular hypertrophy was diagnosed in 57 (31 men/26 women) of all subjects. These patients had higher blood pressure ( P < .05), Lown's score ( P < .001), and QTc dispersion ( P < .001). QTc dispersion and Lown's score were independent predictors of left ventricular mass index ( P < .001). Conclusively, QTc dispersion is a strong indicator of left ventricular mass index and might be used in risk stratification of hypertensive and normotensive elderly patients.
Ephedrine-Induced Acute Myocardial Infarction in a Young Athlete: A Case of Thrombus Management
Authors: Kranjec Igor , Cerne Andreja , Noc Marko
Published: April 2008

A case of acute myocardial infarction in a young athlete provoked by ephedrine abuse has been described in this study. An intracoronary thrombus found in the left anterior descending coronary artery at urgent angiography was successfully removed using the Pronto (Vascular Solutions, Minneapolis, Minnesota) aspiration catheter. The intravascular ultrasound examination performed thereafter showed a nonobstructive atherosclerotic plaque in the culprit artery; there was no evidence whatsoever of possible plaque disruption. The result of percutaneous coronary intervention was satisfactory, and no stent implantation was needed. The patient experienced no adverse events until his outpatient visit 3 months later.
Carotid and Femoral Atherosclerosis in Chronic Hepatitis C: A 5-Year Follow-Up
Authors: Bilora Franca , Campagnolo Enrico , Rinaldi Roberto , Rossato Alberto , Arzenton Marianna , Petrobelli Francesco
Published: April 2008

The objective of this study was to assess the progression of atherosclerosis in carotid and femoral arteries after a 5-year period using ultrasound in subjects with chronic hepatitis C and in controls matched for classic atherosclerotic risk factors. A total of 40 patients and 40 controls were assessed by echocolor Doppler in 2001 and in 2006 to evaluate plaque and intima-media thickness. The patients showed no changes in plaque and intima-media thickness during the 5-year period in all districts examined, whereas a significant increase in intima-media thickness in the carotid sections was recorded in the controls. Chronic hepatitis C seems to cause delay in the atherosclerotic process.
Angina Pectoris with Pharyngeal Pain Alone: A Case Report
Authors: Sone Michiyoshi , Koizumi Akiko , Tamiya Eiji , Inoue Kiyoshi , Ebihara Isao , Koide Hikaru , Okazaki Shinya , Kato Yoshiteru , Suzuki Jun , Daida Hiroyuki
Published: April 2008

Patients with pharyngeal pain are frequently encountered in the department of otorhinolaryngology. The pharyngeal pain is usually caused by an inflammation or a malignant disease. In some cases, anginal pain radiates to the pharynx. However, patients with angina pectoris who suffer from pharyngeal pain without chest pain are believed to be very rare. The patient was a 70-year-old man whose chief complaint was only pharyngeal pain on exertion. The pharyngeal pain was similar to acute pharyngitis with burning pain. Upon cardiac catheterization, no abnormality was found in the right coronary artery or in the circumflex artery, but 99% stenosis was found in the middle portion of the left anterior descending artery. There was no collateral circulation to the left anterior descending artery. Thus, percutaneous coronary intervention was performed, and the pharyngeal pain vanished.