Debulking for in-stent restenosis in the brachytherapy era: does it still have a role?

Despite the advent of intracoronary brachytherapy, treatment of in-stent restenosis, particularly diffuse in-stent restenosis, remains problematic. Adjunctive debulking prior to brachytherapy may improve long-term outcomes. We review the literature and report our results of a series of patients treated with excimer laser coronary atherectomy along with balloon angioplasty and brachytherapy for in-stent restenosis. We conclude that adjunctive debulking may improve the long-term clinical outcomes of patients with diffuse in-stent restenosis treated with angioplasty and intracoronary radiation. A randomized controlled trial is warranted.     

F. Clinical Renal Pharmacology and Therapeutics

Literature Survey

F. Clinical Renal Pharmacology and Therapeutics     

Should minimally invasive aortic valve replacement be restricted to primary interventions?

BACKGROUND: The role of minimally invasive aortic valve replacement in cardiac reoperations has not yet been defined. The purpose of this study is to report our experience with this technique. METHODS: Nineteen consecutive patients underwent aortic valve replacement via J-sternotomy as a reoperative cardiac procedure between 1999 and 2005. The mean age was 73.6 +/- 11.4 years. Previous cardiac operations included 12 (63.2 %) coronary artery bypass graftings, 6 (31.5 %) aortic valve replacements and 1 (5.2 %) mitral valve replacement. Mean follow-up was 23.6 +/- 19.7 months. The medical records were retrospectively analyzed. RESULTS: All procedures were successful. Mean aortic cross-clamping time and cardiopulmonary bypass time were 87.4 +/- 32.7 and 133.1 +/- 54.4 minutes, respectively. Cannulation sites were: ascending aorta (52.6 %), femoral artery (47.4 %), femoral vein (94.8 %) and right atrium (5.2 %). Myocardial protection was obtained by selective coronary osteal cold crystalloid cardioplegia and systemic cooling (mean 26.2 +/- 4 degrees C). Average intubation time was 1.5 +/- 1.4 days. Mean intensive care unit stay and postoperative hospital stay was 2.9 +/- 2.6 and 12.9 +/- 5.7 days, respectively. Median chest tube output was 550 ml. There were 4 revisions for bleeding. There were 2 late deaths and one non-incision related hospital death (5 %). This patient, who was already being treated for chronic dialysis, died on day 22 due to a cerebrovascular accident. CONCLUSIONS: Minimally invasive aortic valve replacement is feasible as a reoperative procedure. Its major advantage is avoidance of cardiac reexposure with potential damage to coronary grafts. We think this technique deserves more widespread application.     

Is Chlamydia pneumoniae a risk factor for peripheral atherosclerosis?

Seroepidemiological studies have shown a relationship between Chlamydia pneumoniae and coronary atherosclerosis. It is not clear whether Chlamydia pneumoniae is also a risk factor for peripheral atherosclerosis. Chlamydia pneumoniae antibodies were measured by a microimmunofluorescence method in 75 patients who underwent surgery for peripheral atherosclerosis, and the seroprevalence was compared with that in the normal population. Chlamydia pneumoniae immunoglobulin-G seroprevalence was 80% in the study group vs. 40% in controls. More foam cells were noted on light microscopy in atherosclerotic plaques from the infected patients. The 60 infected patients were divided into: group A (n = 35) given both anti-chlamydial and antiplatelet agents for 1 year; and group B (n = 25) given antiplatelet therapy only. The groups were compared on the basis of clinical findings, ankle-brachial index, and antibody titers. Decreasing Chlamydia pneumoniae immunoglobulin-G seroprevalence in group A correlated significantly with increasing ankle-brachial index and improvement in clinical findings. It was concluded that Chlamydia pneumoniae may be a risk factor for peripheral atherosclerosis.     

The Heartfile Lodhran CVD prevention project--end of project evaluation

Mainstream preventive interventions often fail to reach poor populations with a high risk of cardiovascular diseases (CVDs) in Pakistan. A community-based CVD primary prevention project aimed at developing approaches to reduce risk factors in such populations was established by Heartfile in collaboration with the National Rural Support Program in the district of Lodhran. The project implemented a range of activities integrated with existing social and health service mechanisms during a three year intervention period 2000/01-03/04. These were targeted in 4 key settings: community health education, mass media interventions, training of health professionals and health education through Lady Health Workers. The project received support from the Department for International Development, U.K. At the community level, a pre-test-post-test quasi-experimental design was used for examining project outcomes related to the community component of the intervention. Pre and post-intervention (training) evaluations were conducted involving all health care providers in randomly selected workshops in order to determine baseline levels of knowledge and the impact of training on knowledge level. In order to assess practices of physician and non-physician health care providers patient interviews, with control comparisons were conducted at each health care facility. Significant positive changes were observed in knowledge levels at a community level in the district of intervention compared with baseline knowledge levels particularly in relation to a heart healthy diet, beneficial level of physical activity, the causes of high blood pressure and heart attack and the effects of high blood pressure and active and passive smoking on health. Significant changes in behaviors at a practice level were not shown in the district of intervention. However the project played a critical role in spurring national action for the prevention and control of non-communicable diseases and introducing sustainable public health interventions for poor communities in Pakistan.     

Contralateral replacement of pacemaker and leads following laser sheath extraction and concomitant stenting for superior vena cava syndrome

We present the case of a 61-year-old man with a history of pacemaker implantation 15 years ago. The patient was admitted with chronic swelling of the right hemithorax and inflammation of the old incision scar after the replacement of pacemaker generator 6 years ago. The patient also presented symptoms and clinical signs of superior vena cava syndrome. Computed tomography of the thorax showed obstruction of the superior vena cava. The surgical procedure consisted of extraction of infected pacemaker system with excimer laser technique followed by dilatation and stenting of the SVC and finally implantation of a new permanent pacemaker system on the left side.     

Alpha heavy chain disease (report of 18 cases from Iraq).

The clinical and pathological features of 18 new patients with alpha heavy chain disease seen at two referral centres in Baghdad, Iraq, are described. The series included 14 males and four females ranging in age from 14 to 47 years. Almost all patients presented because of long-standing abdominal pain and diarrhoea. The tissue diagnosis and extent of the disease were established at laparotomy in most patients. Peroral jejunal biospy was used in a number of patients, mainly for follow-up. The serological abnormality was confirmed by immunoselection technique. Most of the patients had extensive thickening of the bowel wall and/or tumour masses of the small intestine and mesenteric nodes. Histopathological sections showed muscularis. Preliminary results of the treatment, including two long remissions, are reported. In general, our observations agree with those made by other authors, mostly from the Middle East and Africa. We believe that a high index of clinical suspicion, routine use of the immunoselection, and recognition of the early pathological changes may hopefully lead to the detection of more cases before the frank neoplastic phase of the disease.     

Polymer-supported CuPd nanoalloy as a synergistic catalyst for electrocatalytic reduction of carbon dioxide to methane

Developing sustainable energy strategies based on CO₂ reduction is an increasingly important issue given the world’s continued reliance on hydrocarbon fuels and the rise in CO₂ concentrations in the atmosphere. An important option is electrochemical or photoelectrochemical CO₂ reduction to carbon fuels. We describe here an electrodeposition strategy for preparing highly dispersed, ultrafine metal nanoparticle catalysts on an electroactive polymeric film including nanoalloys of Cu and Pd. Compared with nanoCu catalysts, which are state-of-the-art catalysts for CO₂ reduction to hydrocarbons, the bimetallic CuPd nanoalloy catalyst exhibits a greater than twofold enhancement in Faradaic efficiency for CO₂ reduction to methane. The origin of the enhancement is suggested to arise from a synergistic reactivity interplay between Pd–H sites and Cu–CO sites during electrochemical CO₂ reduction. The polymer substrate also appears to provide a basis for the local concentration of CO₂ resulting in the enhancement of catalytic current densities by threefold. The procedure for preparation of the nanoalloy catalyst is straightforward and appears to be generally applicable to the preparation of catalytic electrodes for incorporation into electrolysis devices.Developing sustainable energy resources and strategies to combat the hazards associated with the use of fossil fuels, which include global warming due to the increased concentration of greenhouse gases, is an important theme in the current energy and environmental research agenda (1–3). Electrochemical and photoelectrochemical CO₂ reduction to energy-dense hydrocarbon fuels could play a major role and become part of an integrated energy storage strategy, in combination with solar- or wind-generated electricity, as a way to store energy in the chemical bonds of carbon-based fuels (4–12). Metal-based catalysts for CO₂ reduction have been extensively studied over the last three decades. Metallic copper has proven to be the best available catalytic material for CO₂ reduction to hydrocarbons by electrochemical methods (13–19). Cu foils and single crystals have been extensively investigated but suffer from low surface areas, low catalytic current densities, and rapid deactivation during electrochemical CO₂ reduction (20). Recently, nanoparticle Cu catalysts (nanoCu) have been investigated as a way to increase catalytic current densities and stabilities. However, Faradaic efficiencies for electrocatalytic reduction to hydrocarbons decrease dramatically with particle size falling to ∼10% for particles less than 20 nm in diameter. The size effect has been attributed to an enhanced chemisorption strength for CO at small Cu nanoparticles compared with large particles or bulk Cu electrodes (13). An additional complication arises from the use of surfactants in the syntheses of nanoCu because they can lead to significant contamination issues requiring their removal by a high-temperature posttreatment which causes adverse particle growth and loss of monodispersity (21).Electrodeposition provides a facile and scalable technique for preparing catalytic electrodes. However, it can be difficult to control and typically leads to large particle sizes, often from hundreds of nanometers to micrometers in diameter (22), resulting in low catalytic surface areas. We describe here a novel electrochemical method for synthesizing ultrafine metal nanoparticles and their application to CO₂ reduction. It is based on the use of an electropolymerized, electroactive film of a vinyl-2,2′bipyridine complex of Fe(II). Following treatment with cyanide to displace a bpy ligand and coordinate cyanide, the Fe–CN groups provide a basis for binding metal ions from external solutions (21). After reduction of the film-incorporated metal ions to the corresponding metals, migration occurs to film surfaces where nanoparticles form with size control.An outline for the overall procedure is shown in Fig. 1 for the surface-film–based reduction of Cu(II) to Cu(0). It involves in sequence: (i) Formation of a polymeric film of poly-[Fe(vbpy)₃](PF₆)₂ (vbpy is 4-methyl-4′-vinyl-2,2′-bipyridine) by electropolymerization induced by vbpy-based reduction. The electropolymerization procedure has been applied to polymer film formation on a variety of conductive substrates (23–26) including glassy carbon (GC) electrodes, planar fluorine-doped tin oxide (FTO) slides, reticulated vitreous carbon, and high surface area gas diffusion electrodes. (ii) Addition of cyanide ions which displaces a vbpy ligand from Fe(II) to give poly-Fe(vbpy)₂(CN)₂, poly-vbpy. (iii) Binding of Cu(II) ions from an external solution with coordination to the cyanide ligands. (iv) Electroreduction of the Cu(II) ions to give ultrafine nanoCu of uniform distribution on the surface of the polymeric film.Open in a separate windowFig. 1.Stepwise synthesis of nanoCu. Step 1: A polymeric film of poly-Fe(vbpy)₃(PF₆)₂ is preformed by reductive electropolymerization. Step 2: Cyanide displacement of a vbpy ligand gives the dicyano film poly-[Fe(vbpy)₂(CN)₂,poly-vbpy]. Step 3: Metal ions Cu(II) are incorporated by binding to the cyanide ligands. Step 4: The bound metal ions are electrochemically reduced to metal nanoparticles.The generality of the procedure is also demonstrated with an extension to the synthesis of polymeric films surface-loaded with nanoPd and with bimetallic CuPd nanoalloy. We demonstrate that the Cu-loaded films are electrocatalysts for CO₂ reduction to methane and that, compared with nanoCu, which, to date, is the best catalyst for CO₂ reduction to hydrocarbons (13), the bimetallic CuPd nanoalloy provides an enhancement in Faradaic efficiency for CO₂ reduction to methane of >2 in both aqueous and organic solutions. The notable reactivity enhancement appears to arise from a synergistic mechanism involving Pd–H reduction of adsorbed CO from CO₂ reduction on Cu.     

Hepatic adenomatosis may mimic metastatic lesions of liver with 18F-FDG PET/CT

Hepatic adenomatosis is an uncommon benign neoplasm, with the presence of multiple adenomas (generally more than 4) within the liver. A 52-year-old woman presented with multiple (>10) solid liver lesions detected with abdominal ultrasonography and verified with magnetic resonance imaging (MRI). Subsequently, F-18 FDG PET/CT demonstrated increased uptake in these lesions. Histology revealed hepatic adenomatosis. F-18 FDG PET/CT cannot reliably differentiate hepatic adenomas from malignant processes on the basis of uptake.