bluuebunny/crossref_metadata_2025 huggingface dataset:
Acute Evaluation of Programmer‐Guided AV/PV and VV Delay Optimization Comparing an IEGM Method and Echocardiogram for Cardiac Resynchronization Therapy in Heart Failure Patients and Dual‐Chamber ICD Implants
Authors: BAKER JAMES H. , MCKENZIE JOHN , BEAU SCOTT , GREER G. STEPHEN , PORTERFIELD JAMES , FEDOR MATTHEW , GREENBERG STEVEN , DAOUD EMILE G. , CORBISIERO RAFFAELE , BAILEY J. RUSSELL , PORTERFIELD LINDA
Published: November 2006

Introduction: Intracardiac delay optimization of biventricular and dual‐chamber pacing devices currently relies on time‐consuming echocardiographic measurements. A novel intracardiac electrogram (IEGM) method for atrioventricular (AV/PV) and interventricular (VV) delay optimization was developed, which can be performed during routine device follow‐up.

Methods and Results: In this prospective, nonrandomized, multi‐center trial, patients previously implanted with St. Jude Medical cardiac resynchronization therapy defibrillator (CRT‐D) devices or dual‐chamber implantable cardioverter defibrillators (ICDs) underwent standard AV/PV and/or VV delay optimization guided by Doppler echocardiogram measurements of the maximum aortic velocity time integral (aortic VTI). Aortic VTI measurements applying the IEGM method recommended delays were then obtained in all patients. Fifty‐eight patients (age: 68 ± 11 years; 81% male; 74% ischemic) and 57 patients (age: 71 ± 10 years; 74% male; 71% ischemic) were enrolled for AV/PV and VV delay evaluation, respectively. An independent core lab determined the maximum aortic VTIs.

Data analysis of the AV, PV, and VV delays demonstrated the concordance correlation coefficient (CCC) between the standard method aortic VTI values and the IEGM method aortic VTI values was 97.5%, 96.1%, and 96.6%, respectively. All analyses demonstrated that the CCC > 90% (P < 0.05).

Conclusion: The automated programmer‐based IEGM method provides a reliable and simpler alternative to standard techniques for the optimization of AV/PV and VV delay settings in patients with CRT‐D devices and dual‐chamber ICDs.
Magnetic Navigation in Percutaneous Coronary Intervention
Authors: PATTERSON MARK S. , SCHOTTEN JEROEN , VAN MIEGHEM CARLOS , KIEMENEIJ FERDINAND , SERRUYS PATRICK W.
Published: November 2006

Magnetic navigation is the use of adjustable magnetic fields to precisely direct wires and equipment for clinical applications. It is a recently developed option that is now available for interventional cardiology. Procedures are based on the production of a three‐dimensional reconstruction of the vessel lumen from standard angiographic images. Knowledge of the positions of the table and image intensifier during angiography allows calculation of the vessel coordinates in real space within the patient's chest. The applied magnetic field can be changed at any time to redirect the wire tip in order to improve navigation through complex and tortuous anatomy.

The digital information of the coronary reconstruction can be used in further novel ways. Firstly, the integration of multislice computerized tomography images adds information about the path of the previous lumen of chronic total occlusions. Secondly, the computed center‐line of the reconstructed vessel can be superimposed onto the live fluoroscopy images as a three‐dimensional guide. The combination of improved navigation together with the other available system features may improve time, contrast, and material usage in a range of coronary lesions. Future potential developments include improvements in equipment and software, and potential therapeutic strategies under consideration include the use of equipment to perform remote control procedures, and the integration of the system to improve bone marrow–derived stem cell delivery.
Embolic Protection Devices in Saphenous Vein Graft Interventions
Authors: CRAGUN DAVID T. , HEUSER RICHARD R.
Published: November 2006

Saphenous vein grafts (SVGs) are widely used as aortocoronary conduits during coronary artery bypass surgery and are critical in the high early success of coronary bypass revascularization. Saphenous vein grafts tend to be more prone than native coronary arteries to accelerated atherosclerosis and intimal fibrosis and thus frequently lead to recurrent symptoms and require further revascularization. Percutaneous coronary interventions (PCI) have become the prime means of SVG mechanical revascularization but are plagued by higher complication rates than PCI on native coronaries, largely due to embolic debris mobilized from around the target lesion in the SVG. Several mechanical devices and techniques have been developed to capture this friable material during the PCI before it can embolize; these devices have shown great promise in reducing the morbidity and mortality of these interventions and should be employed routinely.
Review of Interventional Repair for Abdominal Aortic Aneurysm
Authors: CHANE MAJED , HEUSER RICHARD R.
Published: November 2006

Abdominal aortic aneurysm is associated with high mortality rate. For over 50 years, open surgical repair was the standard approach for large aneurysms. However, over the past decade, endovascular aneurysm repair (EVAR) has emerged as a viable alternative. EVAR is associated with lower operative and short‐term morbidity and mortality and similar long‐term survival (up to 4 years) compared with surgical repair. Endoleak remains a significant limitation associated with aneurysm expansion and reintervention. With newer, more versatile endograft designs, improvements in durability, and better surveillance techniques, the utilization of EVAR is likely to continue to expand.
Percutaneous Transcatheter Repair for Mitral Regurgitation
Authors: BLOCK PETER C.
Published: November 2006

Percutaneous mitral valve repair for patients with mitral regurgitation is emerging as an exciting new area in interventional cardiology. Because of the complex etiologies of mitral regurgitation, multiple technologies are being tested in preclinical and clinical settings to evaluate their efficacy and safety. Direct percutaneous repair of the mitral valve is undergoing Phase II and Phase I trials using the Evalve mitral clip and Edwards mitral suture devices, respectively. Devices placed in the coronary sinus might be applicable for specific patient populations where the mitral annulus and coronary sinus have favorable anatomic relationships. Other devices employ intra‐atrial or intra‐ventricular approaches to the mitral annulus to move the posterior annulus forward and thereby improve mitral valve coaptation. How many of these new techniques will ultimately be successful for clinical use will depend on the results of ongoing clinical trials.
Fabrication of Hard and Strong α/β‐Si3N4 Composites With MgSiN2 as Addivitives
Authors: Peng Gui‐hua , Jiang Guo‐jian , Li Wen‐lan , Zhang Bao‐lin , Chen Li‐dong
Published: November 2006

α/β‐Si3N4 composites with various α/β phase ratios were prepared by hot pressing at 1600°–1650°C with MgSiN2 as sintering additives. An excellent combination of mechanical properties (Vickers indentation hardness of 23.1 GPa, fracture strength of about 1000MPa, and toughness of 6.3 MPa·m1/2) could be obtained. Compared with conventional Si3N4‐based ceramics, this new material has obvious advantages. It is as hard as typical in‐situ‐reinforced α‐Sialon, but much stronger than the latter (700 MPa). It has comparable fracture strength and toughness, but is much harder than β‐Si3N4 ceramics (16 GPa). The microstructures and mechanical properties can be tailored by choosing the additive and controlling the heating schedule.
On the Decomposition of Synthetic Gibbsite Studied by Neutron Thermodiffractometry
Authors: Mercury José Manuel Rivas , Pena Pilar , De Aza Antonio H. , Sheptyakov Denis , Turrillas Xavier
Published: November 2006

The thermal decomposition mechanism of synthetic Al(OH)3 (gibbsite) was studied in situ by neutron thermodiffractometry in an ambient atmosphere from room temperature to 600°C with 50°C steps. Gibbsite decomposed to yield AlO·(OH) (boehmite) and then poorly crystallized χ‐Al2O3. Rietveld analysis was used to refine the cell parameters' variation of gibbsite and its thermal expansion coefficients were obtained: for the a‐axis: 15±1 × 10−6 K−1, for b: 10±2 × 10−6 K−1, and for c: 17±2 × 10−6 K−1.
Biocompatibility of different barrier membranes in cultures of human CRL 11372 osteoblast‐like cells: an immunohistochemical study
Authors: Bilir Ayhan , Aybar Buket , Tanrikulu Sinasi H. , Issever Halim , Tuna Sevilcan
Published: November 2006

Objective: The aim of this study was to evaluate the biocompatibility of two different barrier materials in cultures of human osteoblast‐like cells (CRL 11372) in vitro.

Material and methods: Polylactic acid (Epi‐Guide®; EG) and collagen membrane (Bio‐Collagen®, BC) were examined. To analyze the effect of materials on cell proliferation, cell numbers and cell viability, cells were cultured on the barrier membranes for 24 and 72 h. Cells plated on culture dishes (CD) served as positive controls. Cell proliferation rate was assessed by the bromodeoxyuridine (BrdU) immunohistochemical technique. The cell numbers of each well were counted. Cell viability was estimated by counting the number of cells, which excluded trypan blue solution. Scanning electron microscopy (SEM) was used to observe the interactions between osteoblastic cells and barrier membranes.

Results: The highest number of BrdU‐labeled cells were seen on CD after both of the time periods. In comparison with the other two groups, BC showed significantly fewer cells after both time periods. Regarding cell numbers, after 24 and 72 h of incubations CD showed the highest number of cells. The number of viable cells was similar for all the groups. After 72 h for the EG group, SEM view showed flat cells. After 72‐h time periods, the BC group revealed a weak adhesion of cells to the barriers.

Conclusion: The results demonstrate that cells were able to proliferate on these materials and EG promoted the proliferation of human osteoblast like cells. We prefer to use the EG membrane.
Influence of the application of platelet‐enriched plasma in oral mucosal wound healing
Authors: Lindeboom Jérôme A. H. , Mathura Keshen R. , Aartman Irene H. A. , Kroon Frans H. M. , Milstein Dan M. J. , Ince Can
Published: November 2006

Purpose: The aim of this study was to describe and quantify the therapeutic value of platelet concentrate on the capillary density in oral mucosal wound healing.

Material and methods: The subjects included 10 healthy edentulous patients who underwent bilaterally a sinus floor elevation procedure and a buccal onlay graft with autologous iliac crest bone for maxillary reconstruction. During surgery, platelet‐rich plasma (PRP) was prepared from a blood sample taken from the patient. After randomization in a split‐mouth design, at one side PRP was administered in the wound and at the contralateral side a placebo. At baseline, microvascular capillary density was scored with the orthogonal polarization spectral (OPS) imaging technique and repeated measurements were performed postoperatively on a daily basis until the tenth day, after which measurements were continued weekly until the fifth postoperative week.

Results: Ten patients, five males and five females, were included in the study with a mean age of 54.2±9.1 years for females and 57.6±6.9 years for males. Donor platelet counts from whole blood had a mean value of 248.5±13.5 × 109/l, while the value of platelet counts in the PRP had a mean of 975.9±97.9 × 109/l. Wound healing was significantly accelerated in the PRP‐treated mucosal wounds during the first 10 postoperative days. After the second week, no obvious differences between the PRP or placebo side could be noted.

Conclusion: PRP has a strong stimulant effect on capillary regeneration in wound healing. These effects are mainly noticeable during the early stages of wound healing.
The IL1A (−889) gene polymorphism is associated with chronic periodontal disease in a sample of Brazilian individuals
Authors: Moreira P. R. , Costa J. E. , Gomez R. S. , Gollob K. J. , Dutra W. O.
Published: November 2006

Background and Objective:  It has been proposed that genotypes reflective of polymorphisms in cytokine genes can predispose individuals to disease by enhancing inflammatory processes. The C/T polymorphism at position −889 of the IL1A gene influences interleukin‐1α expression, with the T allele inducing higher expression. The aim of this study was to evaluate the association of the IL1A (−889) gene polymorphism in Brazilian individuals with different clinical forms of periodontitis and severity of disease.

Material and Methods:  DNA was obtained from oral swabs of 163 Brazilian individuals and was amplified using the polymerase chain reaction (PCR). Products were submitted to digestion and were analyzed by electrophoresis to distinguish the C and T alleles.

Results:  A significant difference in the genotype distribution was observed when comparing the chronic periodontitis group with the control group, evaluating only nonsmokers (chi‐squared analysis = 9.91; p = 0.007), as well as when smokers were included (chi‐squared analysis = 6.36; p = 0.04). Moreover, we observed a higher incidence of the T allele in the chronic periodontitis group (37.8%) when compared with the control group (18.4%) in nonsmokers (p = 0.006, odds ratio = 2.69, confidence interval = 1.27–5.68) and also when smokers were included (p = 0.03, odds ratio = 1.87, confidence interval = 0.98–3.56). No statistical difference was observed when the aggressive periodontitis group was compared with the control group. With regard to severity of disease, no statistical difference was observed.

Conclusion:  These data show an association of the IL1A (−889) polymorphism with chronic periodontitis in Brazilian individuals.
Hydroperoxide reduction by thioredoxin‐specific glutathione peroxidase isoenzymes of Arabidopsis thaliana
Authors: Iqbal Aqib , Yabuta Yukinori , Takeda Toru , Nakano Yoshihisa , Shigeoka Shigeru
Published: November 2006

Arabidopsis thaliana contains eight glutathione peroxidase (GPX) homologs (AtGPX1–8). Four mature GPX isoenzymes with different subcellular distributions, AtGPX1, ‐2, ‐5 and ‐6, were overexpressed in Escherichia coli and characterized. Interestingly, these recombinant proteins were able to reduce H2O2, cumene hydroperoxide, phosphatidylcholine and linoleic acid hydroperoxides using thioredoxin but not glutathione or NADPH as an electron donor. The reduction activities of the recombinant proteins with H2O2 were 2–7 times higher than those with cumene hydroperoxide. Km values for thioredoxin and H2O2 were 2.2–4.0 and 14.0–25.4 µm, respectively. These finding suggest that GPX isoenzymes may function to detoxify H2O2 and organic hydroperoxides using thioredoxin in vivo and may also be involved in regulation of the cellular redox homeostasis by maintaining the thiol/disulfide or NADPH/NADP balance.
Improvements in Treatment Strategies for Patients With Antineutrophil Cytoplasmic Antibody‐associated Rapidly Progressive Glomerulonephritis
Authors: Hotta Osamu , Ishida Aki , Kimura Tomoyoshi , Taguma Yoshio
Published: November 2006

Abstract:  The course of rapidly progressive glomerulonephritis (RPGN) caused by antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis is often life‐threatening, especially in the elderly when pulmonary involvement and/or severely impaired renal function are present. Corticosteroids and cyclophosphamide are the first‐line treatment, but ironically infection, not vascular events such as hemorrhage, caused by the vasculitis itself, is the most common cause of death of RPGN patients. Several new treatment strategies, such as leukocytapheresis (LCAP) and intravenous immunoglobulin (IVIg), have become available during the past decade and these treatments have made it possible to treat high‐risk RPGN patients without inducing serious immunosuppressive states. In the present paper we review recent clinical trials of LCAP and IVIg therapy in patients with pauci‐immune/ANCA‐associated RPGN, and show improved clinical outcomes after using these new treatment strategies in our institution.
Fluctuations in Peripheral Blood Leukocyte and Platelet Counts and Leukocyte Recruitment With Large Volume Leukocytapheresis in Healthy Volunteers
Authors: Yamaji Ken , Onuma Shin , Yasuda Mitsunori , Kanai Yosinori , Tsuda Hiroshi , Takasaki Yoshinari
Published: November 2006

Abstract:  Based on sporadic reports indicating that the effectiveness of leukocytapheresis (LCAP) is proportional to the number of leukocytes removed, it is anticipated that increasing the volume of blood treated, and thus the number of leukocytes removed, will improve the effectiveness of therapy. In advance of its clinical application, the possible clinical usefulness of large volumes of LCAP (pulse LCAP), which treats 5000 mL of blood rather than the usual volume of 3000 mL, was investigated in healthy subjects. As compared with conventional LCAP, pulse LCAP provided comparable safety and enabled the removal of approximately 4.7 times more neutrophils, 1.2 times more lymphocytes, and 1.6 times more monocytes. It also resulted in a more pronounced overshoot phenomenon, as well as lymphocyte and monocyte overshoot, which are not seen with conventional LCAP. The neutrophil overshoot resulted from the recruitment of leukocytes from the bone marrow neutrophil pool as well as from the circulating neutrophil pool and marginal neutrophil pool. Recruitment from the bone marrow pool involved not only recruitment of mature neutrophils but also recruitment from all stages of differentiation and proliferation, including the pluripotent stem cell (CFU‐GEMM) fraction; granulocyte‐monocyte precursor cell (CFU‐GM) fraction; and the fraction of juvenile granulocyte precursors cells capable of cell division, from myeloblasts to myelocytes. Based on the lymphocyte and monocyte overshoot, it was inferred that cells were recruited from mucosal lymphatic tissue, in addition to the lymph nodes, spleen, thymus, and bone marrow. These phenomena might play an important role in the mechanism that underlies the effectiveness of LCAP and the increased effectiveness of pulse LCAP, and it will be necessary to work to elucidate them. Moreover, it appears that investigating the clinical efficacy of pulse LCAP in patients who do not respond to conventional LCAP would be of major significance.
Cytapheresis for the Treatment of Myeloperoxidase Antineutrophil Cytoplasmic Autoantibody‐Associated Vasculitis: A Pilot Study of 21 Patients
Authors: Hasegawa Midori , Ohashi Atsushi , Kabutan Nao , Hiramatsu Saori , Kato Masao , Murakami Kazutaka , Tomita Makoto , Nabeshima Kunihiro , Hiki Yoshiyuki , Sugiyama Satoshi
Published: November 2006

Abstract:  Twenty‐one patients with myeloperoxidase‐antineutrophil cytoplasmic autoantibody (MPO‐ANCA)‐associated vasculitis were treated using cytapheresis. Of these, 17 were treated for glomerulonephritis and four were treated for pulmonary hemorrhage. The overall survival rate was 85.7% with a follow‐up duration of 24.0 ± 13.8 months. In the 17 patients with MPO‐ANCA‐associated glomerulonephritis, pretreatment creatinine was 3.2 ± 1.6 mg/dL, and renal function recovered in 76.5%. Pulmonary hemorrhage was ameliorated in all four patients. Abdominal pain occurred in three of the 21 patients but symptoms resolved soon after the cytapheresis procedure was completed. No other adverse effects occurred during cytapheresis. From these results, cytapheresis can be considered a safe and effective treatment for MPO‐ANCA‐associated vasculitis. As for the mechanism of its action, soluble tumor necrosis factor receptor 1 (sTNFR), sTNFR2 and interleukin 1 receptor antagonist were elevated soon after cytapheresis and those levels 2 h after the cytapheresis procedure were higher than before the procedure in some cases. These elevations might be related to the efficacy of cytapheresis.
A Case Report of Leukocytapheresis for Refractory Leg Ulcers Complicated With Rheumatoid Arthritis
Authors: Itoh Yoko , Takeshita Yasuyo , Ozawa Yoshinori , Tohma Shigeto , Umemura Satoshi
Published: November 2006

Abstract:  Leukocytapheresis (LCAP) has recently been investigated for the treatment of drug‐resistant rheumatoid arthritis (RA). In the present clinical study, we used LCAP in three patients with rheumatoid arthritis (RA), with drug‐resistant leg ulcers. LCAP was carried out once a week for five weeks. Erythrocyte sedimentation rate, C‐reactive protein, rheumatoid factor titers and tender joint counts did not change when LCAP was used but the ulcers began to recede after the first treatment and, by the end of the fifth treatment, the ulcers had healed. The activated leukocytes that are the major part of the inflammation of skin ulcers are removed from the peripheral blood by LCAP. Thus, it is supposed that the activated leukocytes shift from the inflammatory skin ulcer to peripheral blood, causing the skin ulcer to recover. We hypothesize that LCAP is a useful treatment for refractory leg ulcers complicated with RA.
A Case Report of Pulmonary‐Renal Syndrome Treated With Continuous Hemodiafiltration and Hemodialysis
Authors: Uji Yoshitaka , Shimizu Tomoharu , Yoshioka Toyokazu , Yamamoto Hiroshi , Endo Yoshihiro , Tani Toru
Published: November 2006

Abstract:  This case describes a 40‐year‐old man complaining of general malaise, dyspnea with hemoptysis and anuria. Laboratory data indicated renal failure and the presence of systemic inflammation. His chest radiograph and computed tomography showed bilateral diffuse interstitial alveolar infiltration. These findings indicated acute deterioration of chronic renal dysfunction complicated by interstitial pneumonitis. He initially received daily conventional hemodialysis (HD), an antibiotic and oxygen therapy. However, his renal and pulmonary function continued to deteriorate. Antineutrophil cytoplasm antibodies against myeloperoxidase (MPO‐ANCA) and antibodies against proteinase 3 (PR3‐ANCA) were negative. We suspected that his pulmonary‐renal syndrome was caused by ANCA‐negative vasculitis. We applied mechanical ventilation, pulsed methylprednisolone therapy and continuous hemodiafiltration (CHDF) combined with HD. PaO2/FiO2 ratio and mean pulmonary arterial pressure gradually improved after initiation of CHDF. He was finally separated from mechanical ventilation after 44 days in the hospital. He is currently alive with the support of conventional HD.
Mechanisms of ventricular arrhythmogenesis in mice following targeted disruption ofKCNE1modelling long QT syndrome 5
Authors: Thomas Glyn , Killeen Matthew J. , Gurung Iman S. , Hakim Parvez , Balasubramaniam Richard , Goddard Catharine A. , Grace Andrew A. , Huang Christopher L.‐H.
Published: November 2006

Mutations withinKCNE1encoding a transmembrane protein which coassembles with K+channels mediating slow K+,IKs, currents are implicated in cardiac action potential prolongation and ventricular arrhythmogenicity in long QT syndrome 5. We demonstrate the following potentially arrhythmogenic features in simultaneously recorded, left ventricular, endocardial and epicardial monophasic action potentials from Langendorff‐perfused murineKCNE1−/− hearts for the first time. (1) Prolonged epicardial (57.1 ± 0.5 ms cf. 36.1 ± 0.07 ms in wild‐type (WT),P< 0.001;n= 5) and endocardial action potential duration at 90% repolarication (APD90) (54.4 ± 2.4 ms cf. 48.5 ± 0.3 ms,P< 0.05;n= 5). (2) Negative transmural repolarization gradients (ΔAPD90: endocardial minus epicardial APD90) (−2.5 ± 2.4 ms, compared with 12.4 ± 1.1 ms in WT,P< 0.001;n= 5). (3) Frequent epicardial early afterdepolarizations (EADs) and spontaneous ventricular tachycardia (VT) in 4 out of 5KCNE1−/− hearts but not WT (n= 5). EADs were especially frequent following temporary cessations of ventricular pacing. (4) Monomorphic VT lasting 1.36 ± 0.2 s in 5 out of 5KCNE1−/− hearts, following premature stimuli but not WT (n= 5). (5) Epicardial APD alternans. Perfusion ofKCNE1−/− hearts with 1 μmnifedipine induced potentially anti‐arrhythmic changes including: (1) restored epicardial APD90(from 57.1 ± 0.5 ms to 42.3 ± 0.4 ms,P< 0.001;n= 5); (2) altered ΔAPD90to values (11.2 ± 2.6) close to WT (P> 0.05;n= 5); (3) EAD suppression during both spontaneous activity and following cessation of ventricular pacing (n= 5) to give similar features to WT controls (n= 5); (4) suppression of programmed electrical stimulation‐induced VT; and (5) suppression of APD alternans. These findings suggest arrhythmic effects of reduced outward currents expected inKCNE1−/− hearts and their abolition by antagonism of inward L‐type Ca2+current.
The effect of cerebral hypothermia on white and grey matter injury induced by severe hypoxia in preterm fetal sheep
Authors: Bennet L. , Roelfsema V. , George S. , Dean J. M. , Emerald B. S. , Gunn A. J.
Published: November 2006

Prolonged, moderate cerebral hypothermia is consistently neuroprotective after experimental hypoxia–ischaemia; however, it has not been tested in the preterm brain. Preterm (0.7 gestation) fetal sheep received complete umbilical cord occlusion for 25 min followed by cerebral hypothermia (fetal extradural temperature reduced from 39.4 ± 0.3 to 29.5 ± 2.6°C) from 90 min to 70 h after the end of occlusion or sham cooling. Occlusion led to severe acidosis and profound hypotension, which recovered rapidly after release of occlusion. After 3 days recovery the EEG spectral frequency, but not total intensity, was increased in the hypothermia‐occlusion group compared with normothermia‐occlusion. Hypothermia was associated with a significant overall reduction in loss of immature oligodendrocytes in the periventricular white matter (P< 0.001), and neuronal loss in the hippocampus and basal ganglia (P< 0.001), with suppression of activated caspase‐3 and microglia (isolectin‐B4 positive). Proliferation was significantly reduced in periventricular white matter after occlusion (P< 0.05), but not improved after hypothermia. In conclusion, delayed, prolonged head cooling after a profound hypoxic insult in the preterm fetus was associated with a significant reduction in loss of neurons and immature oligodendroglia, with evidence of EEG and haemodynamic improvement after 3 days recovery, but also with a persisting reduction in proliferation of cells in the periventricular region. Further studies are required to evaluate the long‐term impact of cooling on brain growth and maturation.
Extracellular chelation of zinc does not affect hippocampal excitability and seizure‐induced cell death in rats
Authors: Lavoie Nathalie , Peralta Modesto R. , Chiasson Marilou , Lafortune Kathleen , Pellegrini Luca , Seress László , Tóth Katalin
Published: November 2006

In the nervous system, zinc can influence synaptic responses and at extreme concentrations contributes to epileptic and ischaemic neuronal injury. Zinc can originate from synaptic vesicles, the extracellular space and from intracellular stores. In this study, we aimed to determine which of these zinc pools is responsible for the increased hippocampal excitability observed in zinc‐depleted animals or following zinc chelation. Also, we investigated the source of intracellularly accumulating zinc in vulnerable neurons. Our data show that membrane‐permeable and membrane‐impermeable zinc chelators had little or no effect on seizure activity in the CA3 region. Furthermore, extracellular zinc chelation could not prevent the accumulation of lethal concentrations of zinc in dying neurons following epileptic seizures. At the electron microscopic level, zinc staining significantly increased at the presynaptic membrane of mossy fibre terminals in kainic acid‐treated animals. These data indicate that intracellular but not extracellular zinc chelators could influence neuronal excitability and seizure‐induced zinc accumulation observed in the cytosol of vulnerable neurons.
Inhibition of myosin light‐chain phosphorylation inverts the birefringence response of porcine airway smooth muscle
Authors: Smolensky Alexander V. , Gilbert Susan H. , Harger‐Allen Margaret , Ford Lincoln E.
Published: November 2006

Muscle birefringence, caused mainly by parallel thick filaments, increases in smooth muscle during stimulation, signalling thick filament formation upon activation. The reverse occurs in skeletal muscle, where a decrease in birefringence has been correlated with crossbridge movement away from the thick filaments. When force generation by trachealis muscle was inhibited with wortmannin, which inhibits myosin light‐chain phosphorylation and thick‐filament formation, but not the calcium increase caused by stimulation, the birefringence response inverted, suggesting crossbridge movement similar to that of skeletal muscle. Resistance to quick stretches was much greater in stimulated muscle than in unstimulated muscle before wortmannin treatment and no different in stimulated and unstimulated muscle after force inhibition by wortmannin. Before wortmannin treatment, stimulation reduced thick‐filament cross‐sectional areas in electron micrographs by 44%. After force inhibition by wortmannin, filament areas were not significantly different in stimulated and unstimulated muscle and not significantly different from those of relaxed muscle without wortmannin treatment. These results suggest that myofibrillar‐space calcium causes crossbridges to move away from the thick filaments without firmly attaching to thin filaments.
Rubidium-Rich Asymptotic Giant Branch Stars
Authors: García-Hernández D. A. , García-Lario P. , Plez B. , D'Antona F. , Manchado A. , Trigo-Rodríguez J. M.
Published: November 2006

A long-debated issue concerning the nucleosynthesis of neutron-rich elements in asymptotic giant branch (AGB) stars is the identification of the neutron source. We report intermediate-mass (4 to 8 solar masses) AGB stars in our Galaxy that are rubidium-rich as a result of overproduction of the long-lived radioactive isotope
87
Rb, as predicted theoretically 40 years ago. This finding represents direct observational evidence that the
22
Ne(α,n)
25
Mg reaction must be the dominant neutron source in these stars. These stars challenge our understanding of the late stages of the evolution of intermediate-mass stars and would have promoted a highly variable Rb/Sr environment in the early solar nebula.
Nondestructive Optical Measurements of a Single Electron Spin in a Quantum Dot
Authors: Berezovsky J. , Mikkelsen M. H. , Gywat O. , Stoltz N. G. , Coldren L. A. , Awschalom D. D.
Published: November 2006

Kerr rotation measurements on a single electron spin confined in a charge-tunable semiconductor quantum dot demonstrate a means to directly probe the spin off-resonance, thus minimally disturbing the system. Energy-resolved magneto-optical spectra reveal information about the optically oriented spin polarization and the transverse spin lifetime of the electron as a function of the charging of the dot. These results represent progress toward the manipulation and coupling of single spins and photons for quantum information processing.
Risk factors for new episodes of sick leave due to neck or back pain in a working population. A prospective study with an 18-month and a three-year follow-up
Authors: Bergström Gunnar , Bodin Lennart , Bertilsson Helena , Jensen Irene B
Published: November 2006

Objectives:To identify risk factors for new episodes of sick leave due to neck or back pain.

Methods:This prospective study comprised an industrial population of 2187 employees who were followed up at 18 months and 3 years after a comprehensive baseline measurement. The potential risk factors comprised physical and psychosocial work factors, health-related and pain-related characteristics and lifestyle and demographic factors. The response rate at both follow-ups was close to 73%.

Results:At the 18-month follow-up, 151 participants reported at least one episode of sick-listing due to neck or back pain during the previous year. Risk factors assessed at baseline for sick leave due to neck or back pain at the follow-up were blue-collar work, back pain one or several times during the previous year, 1–99 days of cumulative sickness absence during the previous year (all causes except neck or back pain), uncertainty of one’s own working ability in 2 years’ time and the experience of few positive challenges at work. After 3 years, 127 participants reported at least one episode of sick leave due to back or neck pain during the year previous to follow-up. The risk factors for this pain-related sick leave were blue-collar work, several earlier episodes of neck pain, no everyday physical activities during leisure time (cleaning, gardening and so on), lower physical functioning and, for blue-collar workers separately, repetitive work procedures.

Conclusion:The most consistent risk factors for new episodes of sick leave due to neck or back pain found during both the follow-ups were blue-collar work and several earlier episodes of neck or back pain assessed at baseline. Preventive efforts to decrease sick leave due to neck or back pain may include measures to increase the occurrence of positive challenges at work and to minimise repetitive work procedures. An evidence-based secondary prevention of neck and back pain including advice to stay active is also warranted.
Occupational asthma: an assessment of diagnostic agreement between physicians
Authors: Fishwick David , Bradshaw Lisa , Henson Mandy , Stenton Chris , Hendrick David , Burge Sherwood , Niven Rob , Warburton Chris , Rogers Trevor , Rawbone Roger , Cullinan Paul , Barber Chris , Pickering Tony , Williams Nerys , Ayres Jon , Curran Andrew D
Published: November 2006

Objectives:To investigate the levels of agreement between expert respiratory physicians when making a diagnosis of occupational asthma.

Methods:19 cases of possible occupational asthma were identified as part of a larger national observational cohort. A case summary for each case was then circulated to 12 physicians, asking for a percentage likelihood, from the supplied information, that this case represented occupational asthma. The resulting probabilities were then compared between physicians using Spearman’s rank correlation and Cohen’s κ coefficients.

Results:Agreement between the 12 physicians for all 19 cases was generally good as assessed by Spearman’s rank correlation. For all 66 physician–physician interactions, 45 were found to correlate significantly at the 5% level. The agreement assessed by κ analysis was more variable, with a median κ value of 0.26, (range –0.2 to +0.76), although 7 of the physicians agreed significantly (p<0.05) with ⩾5 of their colleagues. Only in one case did the responses for probability of occupational asthma all exceed the “on balance” 50% threshold, although 12 of the 19 cases had an interquartile range of probabilities not including 50%, implying “on balance” agreement. The median probability values for each physician (all assessing the identical 19 cases) varied from 20% to 70%. Factors associated with a high probability rating were the presence of a positive serial peak expiratory flow Occupation Asthma SYStem (OASYS)-2 chart, and both the presence of bronchial hyper-reactivity and significant change in reactivity between periods of work and rest.

Conclusions:Despite the importance of the diagnosis of occupational asthma and reasonable physician agreement, certain variations in diagnostic assessment were seen between UK expert centres when assessing paper cases of possible occupational asthma. Although this may in part reflect the absence of a normal clinical consultation, a more unified national approach to these patients is required.
Criteria and methods used for the assessment of fitness for work: a systematic review
Authors: Serra Consol , Rodriguez Mari Cruz , Delclos George L , Plana Manel , Gómez López Luis I , Benavides Fernando G
Published: November 2006

The main findings from reports published in scientific journals on the criteria and methods used to assess fitness for work were reviewed. Systematic searches were made using internet engine searches (1966–2005) with related keywords. 39 reports were identified, mostly from the US and western Europe. Assessment of fitness for work is defined by most as the evaluation of a worker’s capacity to work without risk to their own or others’ health and safety. It is mainly assessed at recruitment (pre-offer or post-offer), and when changes of work or health conditions occur. Five main criteria used by occupational doctors to evaluate fitness for work were identified: the determination of worker’s capacity and worker’s risk in relation to his or her workplace, as well as ethical, economic and legal criteria. Most authors agreed that assessment tools used need to be specific and cost-effective, and probably none gives unequivocal answers. Outcomes from fitness for work assessments range from “fit” to “unfit”, with other possible intermediate categories such as “fit subject to work modifications”, “fit with restrictions” or “conditionally fit (temporarily, permanently)”. Workplace modifications to improve or adjust working conditions must always be considered. There is confusion about the decision-making process to be used to judge about fitness for work. There is very scarce scientific evidence based on empirical data, probably because there are no standard or valid methodologies for all professions and circumstances.
UNPRECEDENTED POSSIBILITY OF DISCRETE SCATTERING STATES AND THEIR CONTROL
Authors: CHABANOV V. M. , ZAKHARIEV B. N.
Published: November 2006

The discrete states of unlimited wave motion, "antipodes" of Anderson's localization [Phys. Rev.109, 1492–1505 (1958)] ("continuum of bound states"), are presented. This newly mentioned and an unexpected kind of spectrum appeared to be attainable via a multiple combination of the remarkable phenomenon of resonance tunneling. It was found that this unusual spectral situation takes place for a quantum system of infinite irregularly distributed resonance tunneling potential traps. Generalization of this instructive phenomenon to periodic, multi-channel structures is considered.
INITIAL PROCESSES OF HYDROGEN CHEMISORPTION ON Si(111) SURFACE
Authors: MA LI , WANG JIANGUANG , WANG GUANGHOU
Published: November 2006

The chemisorption of one monolayer H atoms on Si (111) surface is studied by using the self-consistent, tight-binding, linear muffin-tin orbital method. Energies of adsorption systems, the layer projected density of states (LPDOS) and charge distributions are calculated. It is found that the adsorbed H atoms are more favorable on the top site with a distance of 0.185 nm above the Si surface. The LPDOS in the clean surface decreases significantly after H adsorption, since the dangling bonds of the surface atoms are partially saturated by the adsorbed H atoms.
Expression of peroxisome proliferator-activated receptor-γ in macrophage suppresses experimentally induced colitis
Authors: Shah Yatrik M. , Morimura Keiichirou , Gonzalez Frank J.
Published: November 2006

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has been shown to be a protective transcription factor in mouse models of inflammatory bowel disease (IBD). PPAR-γ is expressed in several different cell types, and mice with a targeted disruption of the PPAR-γ gene in intestinal epithelial cells demonstrated increased susceptibility to dextran sulfate sodium (DSS)-induced IBD. However, the highly selective PPAR-γ ligand rosiglitazone decreased the severity of DSS-induced colitis and suppressed cytokine production in both PPAR-γ intestinal specific null mice and wild-type littermates. Therefore the role of PPAR-γ in different tissues and their contribution to the pathogenesis of IBD still remain unclear. Mice with a targeted disruption of PPAR-γ in macrophages (PPAR-γΔMφ) and wild-type littermates (PPAR-γF/F) were administered 2.5% DSS in drinking water to induce IBD. Typical clinical symptoms were evaluated on a daily basis, and proinflammatory cytokine analysis was performed. PPAR-γΔMφmice displayed an increased susceptibility to DSS-induced colitis compared with wild-type littermates, as defined by body weight loss, diarrhea, rectal bleeding score, colon length, and histology. IL-1β, CCR2, MCP-1, and inducible nitric oxide synthase mRNA levels in colons of PPAR-γΔMφmice treated with DSS were higher than in similarly treated PPAR-γF/Fmice. The present study has identified a novel protective role for macrophage PPAR-γ in the DSS-induced IBD model. The data suggest that PPAR-γ regulates recruitment of macrophages to inflammatory foci in the colon.
Stimulation of colonic mucosal growth associated with oxidized redox status in rats
Authors: Tian Junqiang , Washizawa Naohiro , Gu Li H. , Levin Marc S. , Wang Lihua , Rubin Deborah C. , Mwangi Simon , Srinivasan Shanthi , Gao Yuhao , Jones Dean P. , Ziegler Thomas R.
Published: November 2006

Limited data in animal models suggest that colonic mucosa undergoes adaptive growth following massive small bowel resection (SBR). In vitro data suggest that intestinal cell growth is regulated by reactive oxygen species and redox couples [e.g., glutathione (GSH)/glutathione disulfide (GSSG) and cysteine (Cys)/cystine (CySS) redox]. We investigated the effects of SBR and alterations in redox on colonic growth indexes in rats after either small bowel transection (TX) or 80% midjejunoileal resection (RX). Rats were pair fed ± blockade of endogenous GSH synthesis with buthionine sulfoximine (BSO). Indexes of colonic growth, proliferation, and apoptosis and GSH/GSSG and Cys/CySS redox potentials (Eh) were determined. RX significantly increased colonic crypt depth, number of cells per crypt, and epithelial cell proliferation [crypt cell bromodeoxyuridine (BrdU) incorporation]. Administration of BSO markedly decreased colonic mucosal GSH, GSSG, and Cys concentrations in both TX and RX groups, with a resultant oxidation of GSH/GSSG and Cys/CySS Eh. BSO did not alter colonic crypt cell apoptosis but significantly increased all colonic mucosal growth indexes (crypt depth, cells/crypt, and BrdU incorporation) in both TX and RX groups in a time- and dose-dependent manner. BSO significantly decreased plasma GSH and GSSG, oxidized GSH/GSSG Eh, and increased plasma Cys and CySS concentrations. Collectively, these data provide in vivo evidence indicating that oxidized colonic mucosal redox status stimulates colonic mucosal growth in rats. The data also suggest that GSH is required to maintain normal colonic and plasma Cys/CySS homeostasis in these animal models.
An estimate of fetal autonomic state by time-frequency analysis of fetal heart rate variability
Authors: David Maya , Hirsch Michael , Karin Jacob , Toledo Eran , Akselrod Solange
Published: November 2006

In this study we present a noninvasive method that enables the investigation of the fetal heart rate (FHR) fluctuations. The objective was to design a quantitative measurement to assess the fetal autonomic nervous system and to investigate its development as a function of the gestational age. Our Medical Physics group has developed a complex algorithm for online beat-to-beat detection of the fetal ECG (FECG), extracted from the maternal abdominal ECG signal. We used our previously acquired FECG data, which includes noninvasive recordings of 200 maternal abdominal ECG signals. From these, we chose 35 cases of healthy pregnancies that we divided into three groups according to gestational age: Group 1, 23 ± 2 wk; Group 2, 32 ± 1 wk; and Group 3, 39 ± 1 wk. The FHR variability was analyzed by a time-frequency decomposition based on a continuous wavelet transform. We showed that, independent of the gestational age, most of the FHR power is concentrated in the very-low-frequency range (0.02–0.08 Hz) and in the low-frequency range (0.08–0.2 Hz). In addition, there is power in the high-frequency range that correlates with the frequency range of fetal respiratory motion (0.4–1.7 Hz). In the intermediate-frequency range (0.2–0.4 Hz), the power is significantly smaller. The changes in the average power spectrum in relation to gestation time were carefully and quantitatively examined. The results imply that there is a neural organization during the last trimester of the pregnancy, and the sympathovagal balance is reduced with the gestational age.
Circadian variation in swim performance
Authors: Kline Christopher E. , Durstine J. Larry , Davis J. Mark , Moore Teresa A. , Devlin Tina M. , Zielinski Mark R. , Youngstedt Shawn D.
Published: November 2006

Previous findings of time-of-day differences in athletic performance could be confounded by diurnal fluctuations in environmental and behavioral “masking” factors (e.g., sleep, ambient temperature, and energy intake). The purpose of this study was to examine whether there is a circadian rhythm in swim performance that is independent of these masking factors. Experienced swimmers ( n = 25) were assessed for 50–55 consecutive hours in the laboratory. The swimmers followed a 3-h “ultra-short” sleep-wake cycle, involving 1 h of sleep in darkness and 2 h of wakefulness in dim light, that was repeated throughout the observation. The protocol distributes behavioral and environmental masking factors equally across the 24-h period. Each swimmer was scheduled to perform six maximal-effort 200-m swim trials that were distributed equally across eight times of day ( n = 147 trials). Each trial was separated by 9 h. A cosine fit of intra-aural temperature data established the time of the lowest body temperature (Tmin). Swim performances were z-transformed and compared across the eight times of day and across twelve 2-h intervals relative to Tmin. Analysis of covariance, controlling for trial number, revealed a significant ( P < 0.001) pattern in swim performance relative to environmental and circadian times of day. Performance peaked 5–7 h before Tmin(∼2300) and was worst from 1 h before to 1 h after Tmin(∼0500). Mean swim performance was 169.5 s; circadian variation from peak to worst performance was 5.8 s. These data suggest a circadian rhythm in athletic performance independent of environmental and behavioral masking effects.
Factors Predicting Unsuccessful Big Bubble Deep Lamellar Anterior Keratoplasty
Authors: Michieletto Paolo , Balestrazzi Alessandra , Balestrazzi Angelo , Mazzotta Cosimo , Occhipinti Igor , Rossi Tommaso
Published: November 2006

Purpose: To evaluate the role of corneal structural resistance as a surgical failure factor in deep lamellar keratoplasty (DLK). Method: A total of 10 eyes of 10 patients underwent DLK at the Ophthalmic Hospital in Rome. The big bubble technique was performed for deep stromal dissection by air injection. Seven patients were affected by advanced keratoconus and corneal thinning ranging from 441 to 235 µm. Two patients were affected by central corneal opacity from herpetic keratitis, and one patient suffered from corneal leucoma caused by bacterial keratitis. Clinical follow-up comprising final astigmatism and visual acuity findings were evaluated with a minimum follow-up of 12 weeks. Results: DLK was successfully performed in eight eyes, five of which were affected by moderate to advanced keratoconus and three by post-infective corneal opacity. In these patients preoperative ultrasonic pachymetry ranged between 441 and 287 µm. In the remaining two patients a perforation of the Descemet’s membrane (DM) occurred while attempting to separate it from the overlying stroma by the big bubble technique, requiring a penetrating keratoplasty (PK) to be performed. In both cases preoperative ultrasonic pachymetry was below 250 µm. Both perforations occurred at a different site than the needle site and at the operative time of the big-bubble injection. Discussion: An ultrastructurally weakened DM may suffer a loss of resistance to a stressing force, becoming unable to tolerate the big bubble technique, and thus being perforated. Since the weakening of the DM is related to end-stage keratoconus corneal thinning, the preoperative corneal thickness rather than the surgeon’s ability can play a major role in surgical failure of DLK. Our study reveals a very high risk of perforation of the DM when pre-operative total pachymetry is below limit of 250 µm.