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31.
A registry was set up by the national college of cardiologists practicing in general hospitals in February 1993. The data concerned mode of admission, demographic details, initial clinical and haemodynamic evaluation and hospital outcome. Special attention was given to the electrocardiographic changes before and, in patients receiving thrombolytic therapy, after treatment. An analysis of predictive factors for mortality was performed both in the group of patients "revascularised" and in the group treated conventionally. One thousand and twenty three cases from 327 centres were analysed. There were 1292 men and 531 women, with an average age of 67.9 years. The average time interval from onset of symptoms to hospital admission was 5 h 30 min, 56.8% of patients arriving within 6 hours. 36.4% of the population underwent thrombolysis or angioplasty, 75% of patients under 75 years of age admitted before the 5th hours underwent a procedure of myocardial revascularisation. The hospital mortality was 14%, 8.7% in those revascularised and 17% in patients treated conventionally. Factors predictive of mortality were age, female gender, Killip Classes III or IV, systolic blood pressure of less than 100 mmHg, heart rate of more than 100/min and contraindications of thrombolysis. The maximum ST depression, the sum of ST depression, the sum of ST elevation and depression, were also significant predictive factors of a fatal hospital outcome in the whole population group and in patients treated conventionally. In the reperfused group, only the initial sum of ST elevation and depression was predictive of mortality: 120 minutes after the beginning of thrombolysis, the sum of ST elevations and of elevations and depressions was predictive of twice the mortality when the values exceeded 0.6 mv and 1.4 mv respectively.  相似文献   
32.
Our serie of ten canine cutaneous epitheliotropic T-cell lymphomas (CTCL), is found in old dogs, belonging mainly to the Boxer breed. Site on the mucous membranes (especially buccal), the muco-cutaneous junctions, their clinical expression is polymorphous. Lesions, follow on one after another (erythema, plaques, nodules) and are diversely associated in a given animal, the borders between the different stages often being difficult to establish. Adenopathies noted at the time of the diagnosis or during the course of the condition are accompanied by an involvement of the blood and organs (analogous to Sézary's disease). The progression of the disease can be very rapid in the buccal forms, which are generally aggressive, and in cases of violent, uncontrollable pruritus, which may be disturbing for the owner (with requests for euthanasia). The neoplastic infiltrate is constituted of small lymphocytes with hyperchromatic, convoluted nuclei (incipient stages), then large cells with a "histiocytic" appearance for the nodules. Epitheliotropism, which is maximal for the infiltrated plaque stage, shows up either in the form of a flux of totally epitheliotropic isolated cells (Ketron-Goodman type) or in that of Pautrier abscess-like collections. THe veterinary literature is in agreement that the CTCL cell expresses CD3, but two recent studies are in contradiction as regards its membership of helper or cytotoxic/suppressor populations. For our 10 cases, all the cells of lymphocytic morphology were, without exception, CD3+ and CD45+, irrespective of their situation within the epithelium or the chorion. The CD3+ cells in the epithelium were systematically CD8+, CD4- (confirming P.F. Moore's observations), expressing CD5 in a variable way, and, mostly, the Ki-67 nuclear proliferation Ag. The CD3+ cells of the chorion were exclusively, or mainly, CD8+, and occasionally CD4+. They expressed CD5 in a variable way, and, for a minority, the Ki-67 nuclear proliferation Ag. On the pathogenic level, it may be suggested that a T clone, CD8+, undergoes the "homing" phenomenon within the epithelium, enters the cell cycle, then manifests a tropism towards the chorion, which it infiltrates. Despite some particularities, which may be clinical (serious mucous attacks), cytological (the "histiocytic" appearance of the nodule cells) or immunophenotypic (expression of CD8, similar to what is observed in man in a considerable number of Pagetoid reticulosis), CTCL constitutes an interesting model of spontaneous pathology, and could prove useful in: - identifying various etiological factors (given that the dog, as a close commensal of man, is subject to the same environmental factors).  相似文献   
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Codon usage bias of 1,117 Drosophila melanogaster genes, as well as fewer D. pseudoobscura and D. virilis genes, was examined from the perspective of relative abundance of isoaccepting tRNAs and their changes during development. We found that each amino acid contributes about equally and highly significantly to overall codon usage bias, with the exception of Asp which had very low contribution to overall bias. Asp was also the only amino acid that did not show a clear preference for one of its synonymous codons. Synonymous codon usage in Drosophila was consistent with "optimal" codons deduced from the isoaccepting tRNA availability. Interestingly, amino acids whose major isoaccepting tRNAs change during development did not show as strong bias as those with developmentally unchanged tRNA pools. Asp is the only amino acid for which the major isoaccepting tRNAs change between larval and adult stages. We conclude that synonymous codon usage in Drosophila is well explained by tRNA availability and is probably influenced by developmental changes in relative abundance.  相似文献   
35.
Reductive activation of racemic 1,10-bis(acetoxy)-7-methoxymitosene WV15 in the presence of DNA, followed by enzymatic digestion and HPLC analysis, revealed the formation of various DNA adducts. Reduction is a necessary event for adduct formation to occur. This reductive activation was performed under hypoxic conditions in various ways: (1) chemically, using a 2-fold excess of sodium dithionite (Na2S2O4), (2) enzymatically using NADH-cytochrome c reductase, (3) electrochemically on a mercury pool working electrode, and (4) catalytically, using a H2/PtO2 system. Five different mitosene-DNA adducts were detected. These adducts were also present when poly(dG-dC) was used instead of DNA, but were absent with poly(dA-dT). All were shown to be adducts of guanine. Reduction of 1, 10-dihydroxymitosene WV14 in the presence of DNA did not result in detectable adduct formation, demonstrating the importance of good leaving groups for efficient adduct formation by these mitosenes. Finally, two of the adducts were isolated and their structures elucidated, using mass spectrometry, 1H NMR and circular dichroism (CD). The structures were assigned as the diastereoisomers N2-(1"-n-hydroxymitosen-10"-yl), 2'-deoxyguanosine (n = alpha or beta). These type of adducts, in which the mitosene C-10 is covalently bonded to the N-2 of a guanosylic group, are different from the well-known mitomycin C 2'-deoxyguanosine monoadducts, that is linked via the mitomycin C C-1 position, demonstrating that the order of reactivity of the C-1 and C-10 in these mitosenes is reversed, as compared to mitomycin C. The 7-methoxy substituent of WV15 is a likely factor causing this switch. Evidence is presented that the 7-substituent of mitosenes also influences their DNA alkylation site. Adducts 4 and 5 represent the first isolated and structurally characterized covalent adducts of DNA and a synthetic mitosene.  相似文献   
36.
The structural features of apolipoprotein (apo) B that are important for its covalent linkage to apo(a) to form lipoprotein(a) (Lp(a)) are incompletely understood. Although apoB100 cysteine 4326 is required for the disulfide linkage with apo(a), other structural features, aside from a single free cysteine residue, must be important for apoB's initial interaction with apo(a) and for facilitating the formation of the disulfide bond. To determine if sequences carboxyl-terminal to cysteine 4326 affect the efficiency of Lp(a) formation, we used "pop-in, pop-out" gene targeting in a human apoB yeast artificial chromosome to introduce nonsense mutations into exon 29 of the apoB gene. The mutant yeast artificial chromosomes, which coded for the truncated versions of human apoB, apoB95, and apoB97, were then used to express these mutant forms of apoB in transgenic mice. As judged by in vitro assays of Lp(a) formation, apoB95 (4330 amino acids) formed a small amount of Lp(a) but did so slowly. In contrast, apoB97 (4397 amino acids) formed Lp(a) rapidly, although not quite as rapidly as the full-length apoB100 (4536 amino acids). These results were supported by an analysis of double-transgenic mice expressing both human apo(a) and either apoB95 or apoB97. In mice expressing both apoB95 and apo(a), there was only a trace amount of Lp(a) in the plasma, and most of the apo(a) was free, whereas in mice expressing both apoB97 and apo(a), virtually all of the apo(a) was bound to apoB97 in the form of Lp(a). These results show that sequences carboxyl-terminal to apoB95 (amino acids 4331-4536) are not absolutely required for Lp(a) formation, but this segment of the apoB molecule, particularly residues 4331-4397, is necessary for the efficient assembly of Lp(a).  相似文献   
37.
Most of the previously published surgical series of suprasellar meningiomas have two disadvantages: (1) patients involved were treated within a relatively long time period, making analysis more difficult, (2) radiographic long term follow-up examinations with either CT- or MRI-scans were not performed. Both disadvantages were overcome in our retrospective clinical study, consisting of 50 consecutive patients with suprasellar meningiomas treated between 1982 and 1991. Radiological, ophthalmological, and neurological investigations were performed preoperatively, postoperatively and at long term follow-up (mean: 5.7 years). A radiologically confirmed radical tumour removal could be achieved in 84% of patients. Both, the peri-operative mortality (2%) and serious operative morbidity (6%) were low. However, 12% of patients developed late onset epilepsy. At long term follow-up, visual function was improved in 67%, unchanged in 9% and worsened in 24%. In more than 50% of patients the vision showed recovery over a longer time period than the first 10 days after operation. Radiographic control examinations revealed tumour recurrences in 2 patients (both asymptomatic) and progress of residual tumour in 5 patients (2 symptomatic, 3 asymptomatic). Since introduction of modern neurosurgery, a clear improvement in the surgical treatment of suprasellar meningiomas can be observed. However, the still long delay in diagnosing these tumours correctly prevents a further improvement of the ophthalmological results at long-term follow-up. Due to a relatively high rate of late onset epilepsy, anticonvulsive prophylaxis for 6 months seems to be justified. Regarding present preoperative diagnostic measures, ia-DSA seems only be indicated in patients with CT/MRI-scans, suspicious for tumourous narrowing or invasion of major cerebral arteries. In addition, we recommend radiographic control examinations at regular time intervals to confirm radical tumour removal and to detect the "ideal" point of time for renewed treatment.  相似文献   
38.
Seven chlorine-containing orcinol derivatives (2-8) and orcinol (9) have been isolated from diseased bulbs of the edible lily Lilium maximowiczii, and their structures have been elucidated. Six of the chlorinated orcinol derivatives (2, 4-8) showed antifungal activity. Because organochlorine compounds are rare in terrestrial higher plants, their biosynthetic origin was examined. These compounds were shown to be induced in intact bulb scales by UV irradiation or by inoculation with the pathogenic fungus Fusarium oxysporum f. sp. lilii. Biosynthetic studies suggested that these "natural organochlorine pesticides" are produced by enzymatic chlorination of orcinol (9) with chloroperoxidase and hydrogen peroxide, which are both induced in the plant tissue under stress conditions.  相似文献   
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40.
New technologies, either renewables-based or not, are confronted with both economic and technical constraints. Their development takes advantage of considering the basic laws of economics and thermodynamics. With respect to the latter, the exergy concept pops up. Although its fundamentals, that is, the Second Law of Thermodynamics, were already established in the 1800s, it is only in the last years that the exergy concept has gained a more widespread interest in process analysis, typically employed to identify inefficiencies. However, exergy analysis today is implemented far beyond technical analysis; it is also employed in environmental, (thermo)economic, and even sustainability analysis of industrial systems. Because natural ecosystems are also subjected to the basic laws of thermodynamics, it is another subject of exergy analysis. After an introduction on the concept itself, this review focuses on the potential and limitations of the exergy conceptin (1) ecosystem analysis, utilized to describe maximum storage and maximum dissipation of energy flows (2); industrial system analysis: from single process analysis to complete process chain analysis (3); (thermo)economic analysis, with extended exergy accounting; and (4) environmental impact assessment throughout the whole life cycle with quantification of the resource intake and emission effects. Apart from technical system analysis, it proves that exergy as a tool in environmental impact analysis may be the most mature field of application, particularly with respect to resource and efficiency accounting, one of the major challenges in the development of sustainable technology. Far less mature is the exergy analysis of natural ecosystems and the coupling with economic analysis, where a lively debate is presently going on about the actual merits of an exergy-based approach.  相似文献   
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