A Multi-Strategy Adaptive Comprehensive Learning PSO Algorithm and Its Application.

In this paper, a multi-strategy adaptive comprehensive learning particle swarm optimization algorithm is proposed by introducing the comprehensive learning, multi-population parallel, and parameter adaptation. In the proposed algorithm, a multi-population parallel strategy is designed to improve population diversity and accelerate convergence. The population particle exchange and mutation are realized to ensure information sharing among the particles. Then, the global optimal value is added to velocity update to design a new velocity update strategy for improving the local search ability. The comprehensive learning strategy is employed to construct learning samples, so as to effectively promote the information exchange and avoid falling into local extrema. By linearly changing the learning factors, a new factor adjustment strategy is developed to enhance the global search ability, and a new adaptive inertia weight-adjustment strategy based on an S-shaped decreasing function is developed to balance the search ability. Finally, some benchmark functions and the parameter optimization of photovoltaics are selected. The proposed algorithm obtains the best performance on 6 out of 10 functions. The results show that the proposed algorithm has greatly improved diversity, solution accuracy, and search ability compared with some variants of particle swarm optimization and other algorithms. It provides a more effective parameter combination for the complex engineering problem of photovoltaics, so as to improve the energy conversion efficiency.

Adenomas with high-grade dysplasia and early adenocarcinoma are more likely to be sessile in the proximal colon.

AIM: Size and the sessile morphology of an adenoma may explain why colonoscopy is less effective in preventing proximal colonic cancer than distal cancers. We wanted to determine if advanced polypoid neoplasms (APNs, i.e. adenoma with high-grade dysplasia or early adenocarcinoma) are more likely to be sessile and/or smaller in the proximal colon. METHOD: We searched our institution's pathology database from 2004 to 2012 and identified patients with APNs. Polyps were categorized by size, morphology and location in the colon. Average polyp size and morphology were determined for each location. RESULTS: During the study period, 564 patients with APNs were identified. Of these, adenocarcinoma was noted in 21.6% and high-grade dysplasia in 78.4%. The average patient age was 64.4 years and 54.9% were men. The proportion of APNs that were ≤ 5 mm was 1.7%, ≤ 10 mm 19.3% and ≤ 15 mm 39%. APNs in the proximal colon were larger than those in the distal colon, but the difference was not statistically significant (27 vs 24 mm; P = 0.06). Eighty-three per cent of APNs in the proximal colon were sessile vs 57% in the distal colon (P = 0.001). APNs in the proximal colon were almost four times more likely to be sessile than in the distal colon (OR = 3.7). A similar association was noted for polyps ≤ 20 mm or polyps with high-grade dysplasia. CONCLUSION: APNs in the proximal colon were almost four-times more likely to be sessile than those in the distal colon. No difference in the size of polyps was noted.

Use of an improved atpA amplification and sequencing method to identify members of the Campylobacteraceae and Helicobacteraceae.

UNLABELLED: Emerging Campylobacter and Arcobacter spp. have been increasingly isolated from human clinical samples, food, veterinary samples and the environment. Unambiguous species identification of such organisms is of obvious importance in epidemiological studies, but is also necessary to accurately assess their host range and determine their prevalence in the food chain and in the environment. Species identification methods for the Campylobacteraceae have been described; however, some with high resolving power are limited to a small number of taxa, while other broader-range methods cannot distinguish between closely related species. We present in this study a novel species identification method, based on amplification and sequencing of a portion of the atpA gene. This method, which uses a single primer pair, was able to amplify and accurately identify all current taxa within Campylobacter and Arcobacter as well as several members of the Helicobacteraceae, although unambiguous identification of the Camp. fetus subspecies could not be achieved. In addition, five putative novel Campylobacter taxa were recognized, making this new species identification method valuable in the characterization of novel epsilonproteobacteria. Thus, a single-locus method that can accurately identify multiple epsilonproteobacterial species will prove important in the characterization of emerging organisms and those associated with illness. SIGNIFICANCE AND IMPACT OF THE STUDY: The atpA-based species identification method described here uses a single primer pair to amplify DNA from all current validly-described Campylobacter and Arcobacter taxa, as well as multiple members of the Helicobacteraceae. This method unambiguously identified all taxa tested, although it could not discriminate the subspecies of Camp. fetus. Furthermore, five putative novel Campylobacter taxa were observed following testing of environmental campylobacters with this method. The scope and resolution of this method make it an important addition to studies of epsilonproteobacterial epidemiology and evolution.

Milk-induced wheezing in children with asthma.

BACKGROUND: Food allergy has been gaining increasing attention, mostly as causing gastrointestinal and cutaneous reactions. Its role in asthma seems to be under-recognised. OBJECTIVES: This study's aim is to explore the frequency of involvement of a common food, namely cow's milk, in childhood asthma. METHODS: 32 children (5 months to 11 years; median 24 months; mean 34 months) with asthma and a suspected history of cow's milk allergy were studied. They underwent skin prick testing (SPT) and specific IgE (sIgE) testing to whole cow's milk (WCM), casein, α-lactalbumin, and ß-lactoglobulin, followed by single-blind oral milk challenge. RESULTS: Reactions to milk challenge occurred in 12 (37.5%) including wheezing in 5 (41.7%, or 15.6% of the whole group). Children who developed wheezing at the time of challenge were younger than those who had negative challenge (23.0 months vs. 34.8 months). Challenge was positive in 33.3% of subjects who had a positive SPT, and SPT was positive in 50% of challenge-positive subjects. Regarding sIgE, challenge was positive in 26.7% of sIgE-positive subjects, and sIgE was positive in 33.3% of challenge positive subjects. Skin or serum testing with individual protein fractions did not seem to add significant advantage over testing with WCM alone. CONCLUSION: This study shows that cow's milk can cause wheezing in children with asthma. Although SPT seemed to be more reliable than sIgE testing, both had suboptimal reliability. It is worth considering possible milk allergy in children with asthma, particularly when poorly controlled in spite of proper routine management.

Long-term human hematopoiesis in the SCID-hu mouse.

Coimplantation of small fragments of human fetal thymus and fetal liver into immunodeficient SCID mice resulted in the formation of a unique structure (Thy/Liv). Thereafter, the SCID-hu mice showed reproducible and long-term reconstitution of human hematopoietic activity. For periods lasting 5-11 mo after transplantation, active T lymphopoiesis was observed inside the grafts and cells that were negative for T cell markers were found to have colony-forming units for granulocyte/macrophage (CFU-GM) and erythroid burst-forming unit (BFU-E) activity in the methylcellulose colony assay. In addition, structures similar to normal human bone marrow were observed inside the Thy/Liv grafts, consisting of blast cells, mature and immature forms of myelomonocytic cells, and megakaryocytes. These data indicate long-term maintenance, in vivo, of human progenitor cells for the T lymphoid, myelomonocytic, erythroid, and megakaryocytic lineages. The role of the implanted fetal liver fragments was analyzed using HLA-mismatched Thy/Liv implants. The HLA type of the liver donor was found on T cells and macrophages in the graft. In addition, cells grown in the methylcellulose colony assay and cells in a bone marrow-like structure, the "thymic isle," expressed the HLA type of the liver donor. Thus, the Thy/Liv implants provided a microenvironment in which to follow human hematopoietic progenitor cells for multiple lineages. The formation of the Thy/Liv structures also results in a continuous source of human T cells in the peripheral circulation of the SCID-hu mouse. Though present for 5-11 mo, these cells did not engage in a xenograft (graft-versus-host) reaction. This animal model, the first in which multilineage human hematopoietic activity is maintained for long periods of time, should be useful for the analysis of human hematopoiesis in vivo.

Lipid IVA inhibits synthesis and release of tumor necrosis factor induced by lipopolysaccharide in human whole blood ex vivo.

Tumor necrosis factor (TNF) released by lipopolysaccharide (LPS)-stimulated mononuclear phagocytes is a critical mediator of sepsis. We examined the capacities of rough mutant Salmonella typhimurium LPS (Rc) and LPS partial structures lipid A, monophosphoryl lipid A (MPLA), lipid IVA, and lipid X to induce production of TNF in whole blood. Rc LPS (0.0001-10 ng/ml) produced a dose-dependent release of TNF as determined by cytotoxicity of actinomycin D-sensitized L929 murine fibroblasts. Lipid A, MPLA, lipid IVA, and lipid X exhibited decreasing capacities to stimulate production of TNF in whole blood, respectively. Fractional deacylation of LPS by incubation with acyloxyacyl hydrolase isolated from human leukocytes produced a reduction in the capacity of LPS to induce TNF release in whole blood. Maximal enzymatic deacylation reduced activity of LPS by greater than 100-fold. Coincubation with lipid IVA inhibited TNF release induced by Rc LPS or lipid A, but not by phorbol ester. In contrast, MPLA, lipid X, and deacylated LPS failed to inhibit LPS-stimulated release of TNF. Corresponding to the inhibition of the release of TNF protein, lipid IVA also inhibited the accumulation of TNF mRNA in LPS-stimulated mononuclear cells. These results suggest that lipid IVA may act as a competitive antagonist of LPS, perhaps at the receptor level.

A monoclonal antibody to beta 1 integrin (CD29) stimulates VLA-dependent adherence of leukocytes to human umbilical vein endothelial cells and matrix components.

The leukocyte beta 1 integrin receptor very late activation antigen-4 (VLA-4) (alpha 4 beta 1, CD49d/CD29) binds to vascular cell adhesion molecule-1 (VCAM-1) expressed on cytokine-activated endothelium. A mAb designated 8A2 was identified that stimulated the binding of U937 cells to CHO cells transfected with VCAM-1 cDNA but not endothelial-leukocyte adhesion molecule or CD4 cDNA. mAb 8A2 also rapidly stimulated the adherence of peripheral blood lymphocytes (PBLs) to VCAM-1-transfected CHO cells or recombinant human tumor necrosis factor-treated human umbilical vein endothelial cells. mAb 8A2-stimulated binding of PBL was inhibited by mAbs to VLA-4 or VCAM-1. Surface expression of VLA-4 was not altered by mAb 8A2 treatment and monovalent Fab fragments of mAb 8A2 were active. Immunoprecipitation studies reveal that mAb 8A2 recognizes beta 1-subunit (CD29) of integrin receptors. In contrast to mAbs directed to VLA-4 alpha-subunit (alpha 4, CD49d), mAb 8A2 did not induce homotypic aggregation of PBL. Additionally, mAb 8A2 stimulated adherence of PBL and hematopoietic cell lines to purified matrix components laminin and fibronectin. This binding was blocked by mAbs to the VLA alpha-subunits alpha 6 (CD49f), or alpha 5 (CD49e) and alpha 4 (CD49d), respectively. We conclude that mAb 8A2 modulates the affinity of VLA-4 and other leukocyte beta 1 integrins, and should prove useful in studying the regulation of beta 1 integrin function.

Complete Genome Sequence of Campylobacter jejuni Strain 12567, a Livestock-Associated Clade Representative.

We report here the complete genome sequence of Campylobacter jejuni strain 12567, a member of a C. jejuni livestock-associated clade that expresses glycoconjugates associated with improved gastrointestinal tract persistence.

Complete Genome Sequences of Three Campylobacter jejuni Phage-Propagating Strains.

Bacteriophage therapy can potentially reduce Campylobacter jejuni numbers in livestock, but it requires a detailed understanding of phage-host interactions. C. jejuni strains readily infected by certain phages are designated as phage-propagating strains. Here, we report the complete genome sequences of three such strains, NCTC 12660, NCTC 12661, and NCTC 12664.

Determination of patch electrode position for the internal cardioverter-defibrillator by cine computed tomography and its relation to the defibrillation threshold.

Cardioverter-defibrillator implantation in 22 consecutive patients after aborted sudden cardiac death was followed by prospective determination of the correct anatomic position of epicardial patch electrodes by chest X-ray study and cine computed tomography; the data were compared with the defibrillation threshold obtained intraoperatively. Patch electrode position was qualitatively graded. Computed tomography improved the assessment as compared with X-ray study in 13 patients (59%), visualizing electrodes in relation to the underlying myocardial and vascular structures. Although the computed tomographic technique provided more precise visualization, its grading of patch position correlated as poorly as that of the X-ray study with the measured acute defibrillation threshold. Three-dimensional reconstruction by computed tomography made it possible to determine quantitatively left ventricular mass (free wall and septum) and the mass encompassed by the patch electrodes. The 34.6 +/- 13.7% (range 12.6 to 61.1%) of the left ventricular mass encompassed by both patch electrodes showed a linear relation to the defibrillation threshold (r = 0.64, p = 0.01). Differentiation of free wall and septal mass in these measurements revealed that the proportion of septal mass encompassed by patch electrodes correlated closely with the defibrillation threshold (r = -0.6, p = 0.019), whereas that of the free wall mass, although significantly larger (35.4 +/- 15.8 vs. 20.6 +/- 15.4 g, p = 0.007), did not. Thus, the position of epicardial patch electrodes could be reliably determined by computed tomography.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-4 induces endothelial vascular cell adhesion molecule-1 (VCAM-1) by an NF-kappa b-independent mechanism.

While all features of the inflammatory response induced by IL-1 are not observed following IL-4 stimulation, suboptimal concentrations both cytokines result in synergistic VCAM-1 expression in HUVEC. We have shown that, while IL-1 stimulated HUVEC express GM-CSF, tissue factor and VCAM-1, only VCAM-1 is detectable after exposure to IL-4. While kB was found essential for both basal and IL-1-mediated activity of VCAM-1, IL-4 induction was kB-independent. Inducible kB-binding proteins were identified in IL-1-, but not IL-4-stimulated nuclear extracts. Our results indicate that IL-4 exerts its transcriptional effects on the VCAM-1 gene through element(s) which do not require kB.

Quantitation of human haptoglobin: comparative ELISA studies using adsorption and capture methods.

Three ELISA methods for the quantitation of haptoglobin (Hp) in plasma and albumin are described: a polystyrene direct adsorption method and capture methods with antibody and hemoglobin. Hp aggregates generated by 60 degrees C heating showed as much as a hundred-fold higher response by polystyrene adsorption compared to the two capture methods, while unheated Hp showed comparable responses by the three methods.

Reparative approach for right-sided endocarditis. Operative considerations and results of valvuloplasty.

From 1981 to 1986, 12 patients were operated on for right-sided endocarditis after the failure of initial medical treatment (five staphylococcal, three streptococcal, two fungal, one gram-negative, and one mixed organism). The sources of infection were intravenous drugs in six patients, central catheters in two, and malformations in four. Preoperatively, 10 of 12 (83%) of these patients were in class III or IV. Reparative or reconstructive approaches, including valvuloplasty, were attempted for all these right-sided endocarditis lesions and were hemodynamically effective in 10 of 12 (83%) patients. The low right-sided intracardiac pressures and the three-leaflet configuration (one pulmonary and nine tricuspid valves) have lent themselves to this approach. Extensive annular invasion and multileaflet infections were technical limitations in the remaining patients. The overall outcome was favorable during the mean follow-up period of 25 months (hospital mortality 1/12, 8.3%; late death 1/11, 9%). Reparative or reconstructive approaches for right-sided infective endocarditis should be considered and can be successfully achieved. Their advantages include (1) improved hemodynamics, (2) low recurrence, and (3) favorable long-term results without staged or simultaneous prosthetic valve replacement.

Civilian spontaneous pneumothorax. Treatment options and long-term results.

The treatment of spontaneous pneumothorax in the civilian population can be influenced by the age of the patient and the presence of associated pulmonary disease. The medical records of 130 patients who presented with 168 occurrences of SP were reviewed during an 11-year period (1973 to 1984). Follow-up was from a minimum of 30 months to 13 years (mean 6.3 years). The therapeutic options included observation alone (40 occurrences), thoracentesis (6 occurrences), chest tube thoracostomy (102 occurrences), and thoracotomy (20 occurrences). Treatment of SP should be prompt with the objective of complete re-expansion of the lung and prevention of recurrent pneumothorax. This should be accomplished by the use of chest tube thoracostomy with early addition of thoracotomy as necessary. Selected use of thoracentesis can be effective. The use of observation alone can be dangerous and is associated with a higher recurrence rate.

Management of air embolism in blunt and penetrating thoracic trauma.

The charts of 61 patients treated from 1970 through 1981 were reviewed to determine the clinical outcome after treatment of air embolism from blunt (15 patients) and penetrating (21 gunshot and 25 stabbing) thoracic injuries. The diagnosis of air embolism was confirmed by the presence of air in the coronary arteries (57%), air aspirated from the heart (30%) or major artery (10%), or Doppler findings (3%). All patients were in shock or cardiac arrest, and in 36% of these patients there were early signs of hemoptysis or unexpected arrest after intubation and positive-pressure ventilation. Successful management included (1) early thoracotomy for diagnosis as well as for specific treatment, (2) hilar cross-clamping for control of bronchovenous communication, (3) maintenance of perfusion pressures with fluids, vasopressors, or aortic cross-clamping, and (4) prompt correction of the embolic source, usually a lung resection. The overall survival rate was 44%, which correlated with the mechanism of injury, with associated nonthoracic injuries, and with the occurrence of arrest in a controlled setting. We conclude that (1) air embolism can insidiously occur even in blunt trauma; (2) suspicion should be high with hemoptysis or unexpected arrest; and (3) successful treatment includes immediate thoracotomy for diagnosis, resuscitation, and prompt control of the bronchovenous communication.

Ventricular tachycardia with congenital ventricular diverticulum.

A 24-year-old man presented with symptomatic, recurrent, sustained ventricular tachycardia (VT). He was found to have a basal inferior left ventricular diverticulum. His sustained VT was reproduced by programmed electrical stimulation and was unresponsive to procainamide, tocainide, propafenone, and flecainide. Endocardial mapping followed by resection and cryoablative surgery was performed. The patient had only one recurrence after 18 months, with subsequent control with procainamide for over 14 months.

Surgical options for treating ventricular tachyarrhythmia and sudden death.

From 1981 to 1987, 62 patients with ventricular tachyarrhythmias and associated sudden death required treatment after unsuccessful initial medical therapy (51 patients) and previous surgical therapy (11 patients). Surgical options included direct revascularization (group I, 11 patients), endocardial resection (group II, 7 patients), automatic internal cardiac defibrillators (group III, 18 patients), and these combinations of operations: revascularization and endocardial resection (group IV, 18 patients), revascularization and insertion of automatic internal cardiac defibrillators (group V, 5 patients), and endocardial resection and insertion of cardiac defibrillator (group VI, 3 patients). Five underwent repeat revascularization (4) or endocardial resection (4) with mitral valve replacement (1) or papillary muscle reconstruction (2). The overall operative mortality of 8.1% (5/62) has been acceptable (2.8% or 1/36 for the simple procedures [groups I, II, and III] and 15.4% or 4/26 for the combined procedures [IV, V, and VI]; p less than 0.074). Operative risk factors included recent myocardial infarction (4/5 deaths) and depressed ejection fraction of 23% or less (5/5 deaths). These operative risks were highest in group IV and, thus, the highest mortality was in group IV (4/18 patients or 22%, p less than 0.022). Six late deaths (4 patients in group III) brought the overall survival rate to 82% or 51/62 patients at a mean follow-up of 30 months. Surgical treatment of sudden death ventricular tachyarrhythmias requires a planned, combined operative approach, since initial medical or surgical failures can occur. The optimal surgical approach requires complete revascularization, resection of the localized subendocardial arrhythmogenic focus, and ventricular reconstruction. An automatic defibrillator is a palliative alternative for less favorable surgical anatomy and for patients who are poor operative candidates for these combined or reoperative procedures.

Prevention of ischemia-induced myocardial platelet deposition by exogenous prostacyclin.

The antithrombotic effects of prostacyclin infusion on myocardial platelet deposition were studied in a canine model during and after global ischemia. Eleven isolated heart preparations were subjected to 1 hour of cardioplegic arrest under moderate hypothermia (27 degrees to 28 degrees C), including a control group (n = 7) and a prostacyclin-treated group (n = 4). The hearts of four other dogs were continuously perfused for 180 minutes. Platelet deposition was measured at 15 minute intervals throughout the 3 hour study. Serial full-thickness myocardial biopsy specimens were analyzed for activity of 111In-labeled platelets with 99mTc-labeled erythrocyte correction for tissue blood content. The pattern of platelet distribution was determined by scintiscans of each heart, taken with a gamma camera at the end of the 60 minute reperfusion period. Substantial myocardial platelet deposition was found in the control hearts after ischemia but not in the prostacyclin-treated group (p less than 0.05). Furthermore, prostacyclin infusion had a significant disaggregatory effect on intracoronary platelet deposits when the precardioplegic and postcardioplegic biopsy specimens were analyzed (p less than 0.05). Three hours of continuous perfusion did not increase tissue 111In-labeled platelet activity. Ex vivo images showed platelet deposition to be a diffuse patchy process with significantly more 111In activity in the endocardium than in the epicardium after global ischemia (p less than 0.05). These data show the potent antithrombotic properties of prostacyclin in preventing and disaggregating ischemia-induced intracoronary platelet deposition during and after cardioplegic arrest.

The fate of the 12 mm porcine valved conduit from the right ventricle to the pulmonary artery. A ten-year experience.

The 12 mm Dacron conduit containing a porcine valve is the smallest valved conduit manufactured and is used in the youngest infants with the most diminutive pulmonary arterial system. The outcome of patients with such a conduit is unknown. Between 1975 and 1985 there were 49 hospital survivors after placement of a 12 mm extracardiac valved conduit from the right ventricle to the pulmonary artery. Follow-up is available in 42 patients, aged 1 to 16 months (mean 3.5) and weighing 2.5 to 8.7 kg (mean 3.8). Twenty-eight patients (67%) have undergone subsequent conduit replacement, and 11 (26%) are alive and asymptomatic with a mean follow-up of 56 months. There were three late deaths. The interval between implantation and conduit change was 4.5 to 101 months (mean 44), allowing a weight gain of 2.7 to 23 kg (mean 10.4) before reoperation at age 12 to 117 months (mean 49). Despite elevated right ventricular pressures equaling systemic values, 37% of these patients were clinically asymptomatic. The gradient across the 12 mm valved conduit before explantation ranged from 30 to 173 torr (mean 83) with an almost equal predilection for stenosis at the proximal anastomosis, valve, conduit, distal anastomosis, and main pulmonary artery. The intervening pulmonary artery growth determined the size of the replacement conduit, 14 to 25 mm (mean 16), and was the main factor influencing the results of reoperation. This study demonstrates that the 12 mm porcine valve-containing conduit affords palliation in this difficult subset of patients with the smallest pulmonary arterial tree.

Aspirin anticoagulation in children with mechanical aortic valves.

The optimal method of anticoagulation in children with mechanical heart valves is controversial. Between 1975 and 1986, aspirin or aspirin with dipyridamole has been used for anticoagulation in children receiving a mechanical aortic valve at the University of California, San Francisco. Fifty-one patients (ages 1 to 23 years, mean 12.9 years) were treated with aspirin (n = 45) or aspirin with dipyridamole (n = 6) and observed a mean of 36.5 months (range 3 to 100 months). There were four late deaths: two from endocarditis and two from other medical problems, but none related to thrombosis or embolus. Follow-up was accomplished by direct contact with the patient, parent, or referring physician. Two patients (3.9%) were lost to late follow-up. One minor neurologic event occurred perioperatively and resolved spontaneously. There were no postoperative thromboembolic events. Eleven asymptomatic children were recently studied by magnetic resonance imaging or computed axial tomography of the brain and had no evidence of prior silent cerebral thromboembolic defects. There were four patients (5.9%) who had minor hemorrhagic complications: Three patients had nosebleeds and one patient had an upper gastrointestinal hemorrhage. Five patients were changed to warfarin anticoagulation: the patient with upper gastrointestinal hemorrhage and four older patients because of physician preference, all after uncomplicated aspirin therapy. There were no mechanical valve failures, although one patient required reoperation 9 months later for perivalvular leak. All children have remained in normal sinus or paced rhythm during follow-up. These results show that children with mechanical aortic valves in normal sinus rhythm can be safely treated with aspirin (or aspirin with dipyridamole) with little risk of thromboembolic events, valve thrombosis, or valve failure. Hemorrhagic complications resulting from aspirin are minor and easily treated.