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排序方式: 共有2644条查询结果,搜索用时 15 毫秒
81.
SJ Benson BL Ruis AL Garbers AM Fadly KF Conklin 《Canadian Metallurgical Quarterly》1998,72(12):10301-10304
A new subgroup of avian leukosis virus (ALV) that includes a unique env gene, designated J, was identified recently in England. Sequence analysis of prototype English isolate HPRS-103 revealed several other unique genetic characteristics of this strain and provided information that it arose by recombination between exogenous and endogenous virus sequences. In the past several years, ALV J type viruses (ALV-J) have been isolated from broiler breeder flocks in the United States. We were interested in determining the relationship between the U.S. and English isolates of ALV-J. Based on sequence data from two independently derived U.S. field isolates, we conclude that the U.S. and English isolates of ALV-J derive from a common ancestor and are not the result of independent recombination events. 相似文献
82.
RATIONALE AND OBJECTIVES: The authors correlate computed tomography (CT) findings in biphasic spiral technique with histopathology in patients with hepatocellular carcinoma (HCC) who had undergone liver resection (LR) or orthotopic liver transplantation (OLT). METHODS: Preoperative biphasic spiral CT findings in 33 consecutive patients (23 men, 10 women, aged 43-74 years; LR group: n = 17; OLT group; n = 16) with liver cirrhosis and HCC were reviewed retrospectively by consensus of two radiologists and correlated with pathology from liver specimens. RESULTS: Of the 16 patients in the OLT group with 1 to 5 confirmed HCC lesions (total lesions: 29; mean lesion diameter: 2 cm; range: 0.6-5.0 cm), CT before OLT depicted 22 lesions in 15 patients (sensitivity for lesions with a diameter of 0.5-1.0 cm, 20%; for lesions 1.1-2.0 cm, 82%; and for lesions 2.1-3.0 cm and > 3.0 cm, 86% and 100%, respectively). Among the 17 patients in the LR group (total lesions: 21; mean lesion diameter: 5.4 cm; range: 1.0-11.0 cm), CT detected 18 lesions. Lesion-by-lesion sensitivity, as correlated with pathology, was calculated at 76% and 86% in the OLT and LR groups, respectively (overall sensitivity, 80%). The diameter of CT detected lesions, compared with liver specimens, corresponded in 90% of lesions (maximum deviation, 15%). Characteristic CT findings of HCC included unenhanced hypoattenuating focal liver lesions (32 lesions), with hyperattenuation (38 lesions) in the arterial phase of contrast material administration. CONCLUSIONS: Biphasic spiral CT for preoperative HCC detection correlated with pathology in 80%, thus proving this technique to represent a sensitive imaging modality for pretherapeutic evaluation of HCC. 相似文献
83.
SM Gardiner PA Kemp JE March J Woolley T Bennett 《Canadian Metallurgical Quarterly》1998,125(7):1543-1550
Male, Long Evans rats (350-450 g) were anaesthetized and had pulsed Doppler probes and intravascular catheters implanted to allow monitoring of regional (renal, mesenteric and hindquarters) haemodynamics in the conscious state. Our main objectives were to:- assess the effects of administering human recombinant tumour necrosis factor (TNF)-alpha and human recombinant interleukin-1 (IL-1)beta, alone and together; determine the influence of pretreatment with a mixture of antibodies to TNF-alpha and IL-1beta on responses to co-administration of the cytokines; ascertain if pretreatment with a mixture of the antibodies to TNF-alpha and IL-1beta had any influence on the responses to lipopolysaccharide (LPS). TNF-alpha (10, 100 and 250 microg kg(-1), in separate groups, n=3, 9 and 8, respectively) caused tachycardia (maximum delta, +101+/-9 beats min(-1)) and modest hypotension (maximum delta, -10+/-2 mmHg), accompanied by variable changes in renal and mesenteric vascular conductance, but clear increases in hindquarters vascular conductance; only the latter were dose-related (maximum delta, +6+/-6, +27+/-9, and +61+/-12% at 10, 100 and 250 microg kg(-1), respectively). IL-1beta (1, 10, and 100 microg kg(-1) in separate groups, n = 8, 8 and 9, respectively) evoked changes similar to those of TNF-alpha (maximum delta heart rate, +69+/-15 beats min(-1); maximum delta mean blood pressure, -14+/-2 mmHg; maximum delta hindquarters vascular conductance, +49+/-17%), but with no clear dose-dependency. TNF-alpha (250 microg kg(-1)) and IL-1beta (10 microg kg(-1)) together caused tachycardia (maximum delta, +76+/-15 beats min(-1)) and hypotension (maximum A, -24+/-2 mmHg) accompanied by increases in renal, mesenteric and hindquarters vascular conductances (+52+/-6%, +23+/-8%, and +52+/-11%, respectively). Thereafter, blood pressure recovered, in association with marked reductions in mesenteric and hindquarters vascular conductances (maximum delta, -50+/-3% and -58+/-3%, respectively). Although bolus injection of LPS (3.5 mg kg(-1)) caused an initial hypotension (maximum delta, -27+/-11 mmHg) similar to that seen with co-administration of the cytokines, it did not cause mesenteric or hindquarters vasodilatation, and there was only a slow onset renal vasodilatation. The recovery in blood pressure following LPS was less than after the cytokines, and in the former condition there was no mesenteric vasoconstriction. By 24 h after co-administration of TNF-alpha and IL-1beta or after bolus injection of LPS, the secondary reduction in blood pressure was similar (-16+/-2 and -13+/-3 mmHg, respectively), but in the former group the tachycardia (+117+/-14 beats min(-1)) and increase in hindquarters vascular conductance (+99+/-21%) were greater than after bolus injection of LPS (+54+/-16 beats min ' and +439%, respectively). Pretreatment with antibodies to TNF-alpha and IL-1beta (300 mg kg(-1)) blocked the initial hypotensive and mesenteric and hindquarters vasodilator responses to co-administration of the cytokines subsequently. However, tachycardia and renal vasodilatation were still apparent. Premixing antibodies and cytokines before administration prevented most of the effects of the latter, but tachycardia was still present at 24 h. Pretreatment with antibodies to TNF-alpha and IL-1beta before infusion of LPS (150 microg kg(-1) h(-1) for 24 h) did not affect the initial fall in blood pressure, but suppressed the hindquarters vasodilatation and caused a slight improvement in the recovery of blood pressure. However, pretreatment with the antibodies had no effect on the subsequent cardiovascular sequelae of LPS infusion. the results indicate that although co-administration of TNF-alpha and IL-1beta can evoke cardiovascular responses which, in some respects, mimic those of LPS, and although antibodies to the cytokines can suppress most of the cardiovascular effects of the cytokines, the antibodies have little influence on the haemodynamic responses to LPS, possibly because, during infusion of LPS, the sites of production and local action of endogenous cytokines, are not accessible to exogenous antibodies. 相似文献
84.
Assessment of gestational age is one of the most important aims of ultrasonography in obstetrics. As pregnancy progresses, influences of factors which makes the growth of the fetuses different, cumulates. It has been revealed that the earlier in pregnancy ultrasound examination was performed, the better precision in the assessment of gestational age was obtained. The best precision is encountered when Crown-rump length is measured between 7-9 weeks of gestation. Until the end of the half of pregnancy, biparietal measurement allows for better assessment of gestational age than the date of the last menstrual period. As pregnancy progresses the variability of the measurements increases, reaching 7 week variation at term. The aim of this study is the assessment of fetal sacral length ultrasonographic measurements in the calculation of gestational age. The investigated group consists of 453 pregnant women between 16-41 weeks of physiological gestation. 相似文献
85.
N Fernandez L Monge AL Garcia-Villalon JL Garcia B Gomez G Dieguez 《Canadian Metallurgical Quarterly》1995,294(2-3):483-490
The in vitro effects of endothelin-1 on cerebral veins were studied using cylindrical segments, 5 mm long, from dog pial veins. Isometric responses to endothelin-1 (10(-12)-10(-7) M) and to the endothelin ET(B) receptor agonist, IRL 1620 (Suc-[Glu9,Ala11,15]endothelin-1-(8-21), 10(-12) -10(-7) M), were recorded in veins under control conditions and pretreated with the endothelin ET(A) receptor antagonist, BQ-123 (cyclo-(D-Asp-Pro-D-Val-Leu-D-Trp), 10(-8) -10(-5) M), and the endothelin ETB receptor antagonist, BQ-788 (N-[N-[N-[(2,6-dimethyl-1-piperidinyl)carbonyl]-4-methyl-L-leucyl]-1-(me thoxycarbonyl)-D-tryptophyl]-D-norleucine monosodium, 10(-6) and 10(-5) M). The response to endothelin-1 was also recorded in veins pretreated with the nitric oxide synthesis inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME, 10(-4) M), or the cyclooxygenase inhibitor, meclofenamate (10(-5) M), and in veins without endothelium or placed in medium without Ca2+ but with EDTA (0.1 mM). In control veins, endothelin-1 produced a concentration-dependent contraction (EC50 = 2.0 x 10(-10) M; maximal contraction = 113 +/- 6 mg) and IRL 1620 induced no effects or a small contraction only with high concentrations (10(-8) - 10(-6) M) (EC50 = 1.5 x 10 (-8) M; maximal contraction = 9 +/- 3 mg). BQ-123 shifted the response to endothelin-1 to the right in a parallel, concentration-dependent way, whereas BQ-788, L-NAME or meclofenamate did not modify the response to endothelin-1. Compared with the control, veins in a medium without Ca2+ had similar EC50 values, but a lower maximal contraction induced by endothelin-1 (57 +/- 10 mg, P < 0.05), and veins without endothelium exhibited similar EC50 values. Thus, endothelin-1 produces marked cerebral venoconstriction that could be mainly mediated by activation of endothelin ETA receptors, may be dependent on extracellular Ca2+, and may be independent of endothelium, nitric oxide and prostanoids. 相似文献
86.
S Antinori L Galimberti GL Tadini AL Ridolfo C Parravicini R Esposito M Moroni 《Canadian Metallurgical Quarterly》1995,14(10):911-914
Two patients with AIDS and disseminated tuberculosis characterized by cutaneous involvement are reported. They developed a maculopapular skin eruption, from which a multidrug-resistant Mycobacterium tuberculosis strain was isolated. In both cases the clinical course was rapidly fatal. Tuberculosis cutis miliaris disseminata should be differentiated from the skin lesions frequently seen in HIV-infected patients, especially from folliculitis. In patients with tuberculosis, the appearance of cutaneous lesions may be due to the haematogenous dissemination of mycobacteria. Therefore, early identification of the causative organism by use of optimal microbiological methods is fundamental. 相似文献
87.
88.
The use of Etest strips for antimicrobial susceptibility testing is a new and promising method with broad applications in microbiology. Since these strips contain a predefined continuous gradient of a drug, it is possible to obtain a reproducible, quantitative MIC reading. We performed a prospective and double-blinded study to compare the Etest and National Committee for Clinical Laboratory Standards (Villanova, Pa.) broth macrodilution methods for determining the MICs of fluconazole, itraconazole, and ketoconazole for 100 clinical isolates (25 Candida albicans, 25 Cryptococcus neoformans var. neoformans, 20 Torulopsis [Candida] glabrata, 15 Candida tropicalis, and 15 Candida parapsilosis). The Etest method was performed according to the manufacturer's instructions, and the reference method was performed according to National Committee for Clinical Laboratory Standards document M27-P guidelines. Despite differences between results for some species-drug combinations, Etest and macrobroth MICs were, in general, in good agreement. The MIC agreement rates for the two methods, within +/- 1 dilution, were 71% for ketoconazole, 80% for fluconazole, and 84% for itraconazole. According to our data, Etest has potential utility as an alternative method. 相似文献
89.
Functional studies have shown that the murine macrophage resistance gene Lsh/Ity/Bcg (candidate Nramp) regulates macrophage priming/activation for antimicrobial activity via the tumour necrosis factor-alpha (TNF-alpha)-dependent production of reactive nitrogen intermediates. Since Toxoplasma gondii also parasitizes macrophages, is a stimulator of endogenous TNF-alpha release, and is sensitive to nitric oxide-mediated killing in activated macrophages, studies were carried out using chromosome 1 congenic mouse strains to determine whether Lsh influences T. gondii infection. Two interesting observations were made: (i) contrary to expectation, mice carrying the Lsh-resistant allele died earlier over the acute phase of infection than Lsh-susceptible mice; and (ii) Lsh-resistant mice which survived this acute phase of infection showed lower brain cyst numbers than the Lsh-susceptible mice. Whilst the latter occurred independently of route of inoculation (oral, intraperitoneal, or subcutaneous), the former was influenced both by the route of inoculation and the genetic background on which the Lsh-resistant allele had been isolated. Hence, following oral administration of 20 brain cysts of the RRA strain of T. gondii, mice carrying the Lsh-resistant allele on a B10 genetic background showed a significantly enhanced rate of mortality over the acute (first 8-12 days) phase of infection than B10 Lsh-susceptible mice. Although this acute phase of infection in B10 background mice was accompanied by an increase in serum TNF-alpha levels in both Lsh-resistant and -susceptible mouse strains, early mortality preceded the TNF-alpha peak, and administration of neutralizing rabbit anti-TNF-alpha did not significantly enhance survival. Hence, inflammatory mediators other than TNF-alpha appear to be responsible for the increased rate of acute mortality observed in resistant mice. Infection intraperitoneally led to delayed mortality in B10 mice, with the mean time to 50% mortality now being significantly longer in Lsh-resistant than in Lsh-susceptible mice. On a BALB genetic background, it was the i.p. route of infection which led to acute mortality and more rapid death in the Lsh-resistant strain. When a less virulent inoculum was used and mortality delayed, Lsh-susceptible mice died more rapidly, and i.p. administration of rabbit anti-TNF-alpha led to 100% mortality between days 8 and 10 of infection in both susceptible and resistant mouse strains, consistent with a crucial protective role for TNF-alpha during this phase of infection.(ABSTRACT TRUNCATED AT 400 WORDS) 相似文献
90.
AL Evdonin DB Tvorogov NV Tsupkina NN Nikol'ski? ND Medvedeva 《Canadian Metallurgical Quarterly》1998,40(7):648-651
It is known that the growth factor activates appropriate membrane receptors which become starting points of cascades of protein-protein interactions leading to cellular response. Recent data suggest that different signalling pathways may cross-talk during the cellular response. Here we show that phosphoinositide-specific phospholipase C gamma 1, one of the key elements in phosphoinositide pathway of signal transduction, is physically associated with members of the STAT pathway. The precipitation of phospholipase C gamma 1, using polyclonal antibody in A-431 cells, leads to co-immunoprecipitation of STAT1 alpha and STAT1 beta, as well as STAT3. The formation of such complexes was observed in both unstimulated and EGF stimulated cells. The participation of SH3-domains in the formation of such complexes is discussed. 相似文献