BACKGROUND: Although several shortterm animal models of stunning and hibernation have been studied extensively, it has been difficult to produce a consistent animal model of chronic hibernation. The aim of the present study was to develop a nonsurgical porcine stent model of coronary stenosis in order to investigate the relationship between chronic dysfunctional myocardium and viability using 2D-echo, dobutamine stress echo (DSE) and positron emission tomography (PET). METHODS AND RESULTS: Focal progressive coronary stenosis was induced by implantation of an oversized stent in the left anterior descending (LAD) and/or circumflex (LCX) coronary artery in a total of 115 pigs, according to various experimental protocols: copper stent in the LAD (group I, n = 5); noncoated stainless steel stent in the LAD combined with balloon overstretch (group II, n = 7); poly(organo)phosphazene-coated stent in the LAD (group III, n = 77); and poly(organo)phosphazene-coated stent in both the LAD and the LCX (group IV, n = 26). Occurrence of left ventricular dysfunction was evaluated weekly by 2D-echo. At the time of left ventricular dysfunction the presence of viable myocardium within the dysfunctional region was investigated with DSE and PET, and confirmed by histology. The degree of coronary artery stenosis was measured by quantitative coronary angiography and morphometry. Severe coronary artery stenosis in the presence of dysfunctional, but viable, myocardium was induced in groups III and IV (47% and 11% of the animals, respectively). CONCLUSIONS: The authors developed a nonsurgical porcine stent model of progressive coronary stenosis using an oversized polymer-coated stent resulting in chronically decreased myocardial function, with residual inotropic reserve and viable myocardium. This condition may arise from repetitive periods of ischemia, or from sustained hypoperfusion, or a combination of these processes eventually leading to myocardial hibernation. (Int J Cardiovasc Intervent 2000; 3: 111-120) 相似文献
Preparations of live or lysates ofMycobacterium bovis strain Calmette-Guérin (BCG) have long been used as treatments for a variety of cancer types, especially those involving the urinary tract, with varying success. This study was conducted to compare the antitumoral activity of BCG and the thermostable macromolecular antigen complex of BCG (A60) when used as preventive treatments, in conjunction with or without tumor antigens, against growth and dissemination of the EMT6 murine tumor cell line. It was demonstrated that tumor antigens alone did not significantly alter the oncological indexes, although a slight increase in both T lymphocyte and macrophage activations was found. It was further demonstrated that A60 induces a protective activity up to 40% greater than that of live BCG and that this protection was not accompanied by any of the adverse effects sometimes observed during BCG immunotherapy.Abbreviations BCGMycobacterium bovis
strain Calmette-Guérin
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A60
the thermostable macromolecular antigen complex ofM. bovis BCG
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EMT6
murine transplantable mammary adenocarcinoma
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ELISA
enzyme-linked immunosorbent assay 相似文献
BACKGROUND & AIMS: Collagenous colitis (CC) is a well-described entity causing chronic diarrhea and characteristic histologic findings. Several treatment options have been suggested, but no controlled data are available. We conducted a placebo-controlled trial to show the clinical and histologic effects of budesonide in CC. METHODS: Twenty-eight patients were randomly assigned to receive placebo (n = 14) or budesonide 9 mg daily (n = 14) for 8 weeks. Patients were evaluated clinically, and blinded biopsy specimens were analyzed from fixed locations at weeks 0 and 8. Clinical response was defined as a decrease of at least 50% in the disease activity score (number of bowel movements in the last 7 days). At week 8, nonresponders received open-label budesonide for the next 8-week period; responders discontinued treatment and were followed up. RESULTS: Three patients discontinued the study prematurely. Intention-to-treat analysis showed clinical response in 8 of 14 patients in the budesonide group compared with 3 of 14 responders for placebo (P = 0.05) after 8 weeks of blinded therapy, together with improved stool consistency. Histologically, there was no change in the mean thickness of the collagen band but a significant decrease of the lamina propria infiltrate in the budesonide group (P < 0.001). CONCLUSIONS: Budesonide is efficacious in inducing short-term clinical response in CC with significant reduction of the histologic infiltrate in the lamina propria. 相似文献
We review changes in the status of butterflies in Europe, focusing on long-running population data available for the United Kingdom, the Netherlands, and Belgium, based on standardized monitoring transects. In the United Kingdom, 8% of resident species have become extinct, and since 1976 overall numbers declined by around 50%. In the Netherlands, 20% of species have become extinct, and since 1990 overall numbers in the country declined by 50%. Distribution trends showed that butterfly distributions began decreasing long ago, and between 1890 and 1940, distributions declined by 80%. In Flanders (Belgium), 20 butterflies have become extinct (29%), and between 1992 and 2007 overall numbers declined by around 30%. A European Grassland Butterfly Indicator from 16 European countries shows there has been a 39% decline of grassland butterflies since 1990. The 2010 Red List of European butterflies listed 38 of the 482 European species (8%) as threatened and 44 species (10%) as near threatened (note that 47 species were not assessed). A country level analysis indicates that the average Red List rating is highest in central and mid-Western Europe and lowest in the far north of Europe and around the Mediterranean. The causes of the decline of butterflies are thought to be similar in most countries, mainly habitat loss and degradation and chemical pollution. Climate change is allowing many species to spread northward while bringing new threats to susceptible species. We describe examples of possible conservation solutions and a summary of policy changes needed to conserve butterflies and other insects. 相似文献
OBJECTIVE: To study the expression of Toll-like receptor 2 (TLR-2) and TLR-4 and its association with proinflammatory cytokines in synovial tissue from patients with rheumatoid arthritis (RA), osteoarthritis (OA), and healthy individuals. METHODS: Synovial tissue specimens from 29 RA patients were stained for TLR-2, TLR-4, and proinflammatory cytokines (interleukin-1beta [IL-1beta], IL-12, IL-17, IL-18, and tumor necrosis factor alpha [TNFalpha]). The expression of TLR-2, TLR-4, and cytokines as well as the degree of inflammation in synovial tissue were compared between patients with RA, patients with OA (n = 5), and healthy individuals (n = 3). Peripheral blood mononuclear cells (PBMCs) were incubated with IL-12 and IL-18, and TLR expression was assessed using fluorescence-activated cell sorter analysis. Production of TNFalpha and IL-6 was measured using Luminex bead array technology. RESULTS: In RA synovial tissue, the expression of TLR-2 was slightly higher than that of TLR-4. Interestingly, both TLR-2 and TLR-4 were expressed at higher levels in moderately inflamed synovium, as compared with synovial tissue with no or severe inflammation. TLR expression in both the lining and the sublining was associated with the presence of IL-12 and IL-18, but no other cytokines, in the lining. The expression of both TLRs was low in synovial tissue from OA patients and healthy donors. Stimulation of PBMCs with IL-12 and IL-18 resulted in increased expression of both TLR-2 and TLR-4; this could be blocked with anti-interferon-gamma (anti-IFNgamma) antibodies, suggesting a role for IFNgamma. Lipopolysaccharide- or lipoteichoic acid-mediated triggering of PBMCs incubated with IL-12/IL-18 or IFNgamma led to an increased production of both TNFalpha and IL-6, indicating the functionality of TLR-2 and TLR-4. CONCLUSION: TLR-2 and TLR-4 are expressed in synovial tissue of patients with clinically active disease and are associated with the levels of both IL-12 and IL-18. The synergistic effect of IL-12 and IL-18 on T cell IFNgamma production seems to regulate expression of TLR-2 and TLR-4 in the synovial tissue of RA patients. 相似文献
In this survey, we studied the effect of extensive amikacin usage on the epidemiology of aminoglycoside resistance in a general hospital. The baseline resistance in the 12 months before amikacin was 5.8% for amikacin, 15.2% for gentamicin, 16.4% for tobramycin and 14.0% for netilmicin. During the following 44 months, amikacin was the aminoglycoside of first choice. In the first 2 years of this phase, resistance to amikacin did not change significantly. Later, amikacin resistance rose significantly, mainly due to the introduction of amikacin-resistant Enterobacter aerogenes strains. In general there was a significant decrease in resistance to gentamicin and tobramycin. Resistance mechanisms were examined in 380 strains. AAC(3)V, and AAC(6')I alone or coupled with ANT(2") or AAC(3) were the most prevalent enzymes. In the amikacin phase, we noticed a significant increase of strains harbouring the AAC(6')I enzyme, while strains with the AAC(3)V were less frequently isolated. Strains with permeability resistance did not become more prevalent during the period of extensive amikacin use. 相似文献
Around one third of schizophrenia patients are non-responders to antipsychotic therapy. The present study aimed to delineate the pathway-phenotypes of non-remitters (NRTT) and partial remitters (PRTT) to treatment with antipsychotics as defined using the Global Clinical Impression scales. We recruited 60 NRTT, 50 PRTT and 43 healthy controls and measured schizophrenia symptoms, neurocognitive tests, plasma CCL11, interleukin-(IL)-6, IL-10, Dickkopf protein 1 (DKK1), high mobility group box-1 protein (HMGB1), κ- and μ-opioid receptors (KOR and MOR, respectively), endomorphin-2 (EM-2), and β-endorphin. Soft independent modeling of class analogy (SIMCA) showed that NRTT and PRTT are significantly discriminated with a cross-validated accuracy of 94.7% and are qualitatively distinct classes using symptomatome, and neuro-immune-opioid-cognitome (NIOC) features as modeling variables. Moreover, a NIOC pathway phenotype discriminated PRTT from healthy controls with an accuracy of 100% indicating that PRTT and controls are two qualitative distinct classes. Using NIOC features as discriminatory variables in SIMCA showed that all PRTT were rejected as belonging to the normal control class and authenticated as belonging to their target class. In conclusion, a non-response to treatment can best be profiled using a SIMCA model constructed using symptomatome and NIOC features. A partial response should be delineated using SIMCA by authenticating patients as controls or PRTT instead of using scale-derived cut-off values or a number of scale items being rated mild or better. The results show that PRTT is characterized by an active NIOC pathway phenotype and that both NRTT and PRTT should be treated by targeting neuro-immune and opioid pathways.