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排序方式： 共有4083条查询结果，搜索用时 15 毫秒
41.
RG Jaeger PT de Oliveira MM Jaeger VC de Araújo 《Canadian Metallurgical Quarterly》1997,84(6):663-667
BACKGROUND: Endoscopic sclerotherapy (ST), widely used as treatment of bleeding esophageal varices, might cause motility disturbances of the esophagus as well as mucosal damage. We performed this study to evaluate the long-term effects of repeated sclerotherapy on esophageal motility and mucosa. METHODS: Ten patients with liver cirrhosis and bleeding esophageal varices treated with repeated ST were evaluated after the last ST, median 52 months, by esophageal manometry and gastroscopy where forceps biopsies were taken. RESULTS: We found a significant difference in the distal esophageal sphincter intraabdominal length. The distal esophageal sphincter pressure was somewhat lower in the ST group although the difference did not reach statistical significance. There was infiltration of neutrophil leukocytes in biopsies from four patients and normal findings in the rest. CONCLUSIONS: Long-term follow-up evaluation showed statistically longer distal esophageal intraabdominal length in the ST group. No mucosal alterations were found at the histopathological investigation. 相似文献
42.
TM Behr WS Becker RM Sharkey ME Juweid RM Dunn HJ Bair FG Wolf DM Goldenberg 《Canadian Metallurgical Quarterly》1996,37(5):829-833
The renal uptake of radiolabeled antibody fragments and peptides presents a problem in radioimmunodetection and therapy, compromising lesion sensitivity, especially with intracellularly-retained isotopes. Previously, we showed that cationic amino acids and their derivatives are capable of significantly reducing kidney uptake in animals. We report our initial clinical results of successful renal uptake reduction in five patients who underwent cancer radioimmunodetection with 99mTc-anti-CEA Fab' fragments. METHODS: The patients were infused with two liters of a commercially-available nutritive amino acid solution (containing approximately 2.25 g/liter lysine-glutamate and 2.50 g/liter arginine), whereas 75 control patients received the same volume of saline (quantification of organ and tumor kinetics from conjugate whole-body views by ROI technique). RESULTS: The renal uptake in the amino acid group was significantly lower (p<0.05) than in the control group (11.1 +/- 2.0% injected dose versus 17.7 +/- 7.0% injected dose at 24 hr postinjection), whereas the uptake of all other organs remained unaffected. Gel filtration chromatography of the urine taken from amino-acid-treated patients showed that a significantly higher amount of excreted activity was bound to intact Fab' (53% of excreted activity) in contrast to only less than 10% in the control group. CONCLUSION: The renal uptake of monoclonal antibody fragments in patients can be reduced significantly by amino acid infusion, even at considerably lower doses than those that were safe and effective in animals. As was found in animals, the mechanism seems to rely on an inhibition of the re-absorption of tubularly-filtered proteins by the proximal tubule cells. These results encourage further clinical trials to lower the renal uptake experienced in radioimmunodetection, as well as in therapeutic trials with antibody fragments and peptides. 相似文献
43.
DM Skyba G Camarano NC Goodman RJ Price TC Skalak S Kaul 《Canadian Metallurgical Quarterly》1996,28(5):1292-1300
OBJECTIVES: We sought to 1) study the effects of FS-069 on cardiac and systemic hemodynamic function, myocardial blood flow, left ventricular wall thickening and pulmonary gas exchange when injected intravenously; and 2) compare the myocardial kinetics and microvascular rheology of FS-069 and Albunex when injected directly into a coronary artery. BACKGROUND: FS-069 is a second-generation echocardiographic contrast agent composed of perfluoropropane-filled albumin microspheres; it is capable of consistent and reproducible myocardial opacification from a venous injection. METHODS: Nine dogs were used to study the effects of FS-069 on hemodynamic function, pulmonary gas exchange, left ventricular wall thickening and myocardial blood flow and to characterize its myocardial kinetics when injected intravenously. These dogs were also used to compare the myocardial kinetics of FS-069 with those of Albunex during intracoronary injections. Nine Sprague-Dawley rats were used to compare the microvascular rheology of these two contrast agents, and in vitro modeling was performed to assess whether the microvascular findings of FS-069 can explain its echocardiographic behavior during direct coronary injections. RESULTS: There were no effects of 30 rapid venous injections of FS-069 (every 20 s) on cardiac output; mean aortic, pulmonary or left atrial pressures; and peak positive and negative first derivative of left ventricular pressure (dP/dt). Similarly, there were no effects of this agent on radiolabeled microsphere-measured regional myocardial blood flow, left ventricular wall thickening or pulmonary gas exchange. When injected intravenously, the myocardial transit of this agent resembled a gamma-variate form. When diluted FS-069 was injected directly into the coronary artery; however, its transit resembled the integral of gamma-variate function, with persistent myocardial opacification lasting several minutes, which was different from that of Albunex. Intravital microscopy revealed that, unlike Albunex, when no bubbles are entrapped within the microcirculation after an arterial injection, a very small fraction of the diluted, larger FS-069 microbubbles are entrapped. In vitro modeling confirmed that this small fraction of microbubbles can result in persistent myocardial opacification. CONCLUSIONS: FS-069 produces no changes in hemodynamic function, myocardial blood flow, left ventricular wall thickening or pulmonary gas exchange when injected intravenously in large amounts. When diluted FS-069 is injected into the coronary artery, a very small fraction of the larger bubbles are entrapped within the microcirculation, resulting in a persistent contrast effect. Thus, although FS-069 is a safe intravenous echocardiographic contrast agent, it cannot provide information on myocardial blood flow when injected directly into a coronary artery. 相似文献
44.
CM Snapper F Rosas MA Moorman L Jin K Shanebeck DM Klinman MR Kehry JJ Mond CR Maliszewski 《Canadian Metallurgical Quarterly》1996,8(6):877-885
IFN-gamma has been shown to either stimulate or inhibit Ig secretion. No studies have yet addressed the basis for these seemingly conflicting properties nor whether IFN-gamma acted directly at the level of the B cell to mediate its effects. Thus, we studied the ability of IFN-gamma to regulate Ig secretion in sort-purified, resting murine B cells that were >99% Ig+, activated either through membrane Ig using unconjugated or dextran-conjugated anti-IgD antibodies (alphadelta-dex) or through CD40 using soluble or membrane CD40 ligand (CD40L). B cells activated with alphadelta-dex proliferated but do not secrete Ig, even in the presence of IL-1 + IL-2. We demonstrate that IFN-gamma only when added subsequent to B cell stimulation with alphadelta-dex, but not unconjugated anti-IfD antibody, plus IL-1 + IL-2 induces up to 100-fold enhancements in Ig secretion and in the numbers of Ig-secreting cells. The predominant Ig isotype secreted is IgM, with IgG3 and IgG2a comprising the majority of non-IgM antibody. IFN-gamma must act in concert with IL-2 for stimulation of Ig secretion. Further, IFN-gamma synergizes with IL-3 + granulocyte-macrophage colony stimulating factor for induction of Ig synthesis. IFN-gamma also enhances IgA syntheses by transforming growth factor-beta-induced membrane IgA+ cells. By contrast, 125IIFN-gamma fails to stimulate Ig secretion in B cells activated with CD40L in the presence or absence of IL-1 + IL-2 or IL-4. However, the combination of CD40L and alphabeta-dex is strongly synergistic for IFN-gamma-induced Ig secretion. Thus, these data establish that IFN-gamma can act directly on the B cell to induce Ig synthesis without the participation of any other cell and demonstrates that the mode of activation of the B cell plays an important role in directing the action of IFN-gamma. 相似文献
45.
OBJECTIVE: To evaluate angiogenesis in squamous cell carcinoma in situ (CIS) and microinvasive squamous cell carcinoma of the uterine cervix and to investigate the relations among angiogenesis, stromal inflammation, and depth of invasion. METHODS: Three groups of women were studied: 22 controls who had undergone hysterectomy for benign conditions; 18 with squamous cell CIS of the cervix who underwent cone biopsy, hysterectomy, or both; and 14 with microinvasive squamous cell carcinoma who underwent conization of the cervix and subsequent surgical management according to depth of invasion. All specimens were stained immunohistochemically for factor VIII-related antigen. Areas below the basement membrane with the highest angiogenic density were selected. The degree of stromal inflammatory reaction was assessed. Statistical analyses included Kruskal-Wallis, analyses of variance and covariance, Scheffe and Bonferroni-Dunn post hoc procedures, and Pearson correlation analysis. P < .05 was considered statistically significant. RESULTS: Microvessel counts per high-power field (x 400) of microinvasive squamous cell carcinoma of the cervix differed significantly from those of controls and squamous cell CIS (median 34.5 per high-power field, range 9-76 versus median 17, range 7-47, and median 19, range 8-39, respectively; P < .005). Microvessel counts per high-power field in squamous cell CIS did not differ significantly from those of controls (P = .91). Among patients with microinvasive squamous cell carcinoma of the cervix, no significant correlation was found between microvessel counts per high-power field and the depth of invasion (r = 0.19, P = .51). Stromal inflammatory reaction (graded 0-3) differed significantly among controls, squamous cell CIS, and microinvasive carcinoma (mean 0.40, 0.83, and 1.64, respectively; P < .005). CONCLUSIONS: Microinvasive squamous cell carcinoma of the uterine cervix is angiogenic, but depth of invasion is not associated with increased angiogenicity. Squamous cell CIS is not angiogenic. 相似文献
46.
47.
NA Giese L Gabriele TM Doherty DM Klinman L Tadesse-Heath C Contursi SL Epstein HC Morse 《Canadian Metallurgical Quarterly》1997,186(9):1535-1546
Mice with a null mutation of the gene encoding interferon consensus sequence-binding protein (ICSBP) develop a chronic myelogenous leukemia-like syndrome and mount impaired responses to certain viral and bacterial infections. To gain a mechanistic understanding of the contributions of ICSBP to humoral and cellular immunity, we characterized the responses of control and ICSBP-/- mice to infection with influenza A (flu) and Leishmania major (L. major). Mice of both genotypes survived infections with flu, but differed markedly in the isotype distribution of antiflu antibodies. In sera of normal mice, immunoglobulin (Ig)G2a antibodies were dominant over IgG1 antibodies, a pattern indicative of a T helper cell type 1 (Th1)-driven response. In sera of ICSBP-/- mice, however, IgG1 antibodies dominated over IgG2a antibodies, a pattern indicative of a Th2-driven response. The dominance of IgG1 and IgE over IgG2a was detected in the sera of uninfected mice as well. A seeming Th2 bias of ICSBP-deficient mice was also uncovered in their inability to control infection with L. major, where resistance is known to be dependent on IL-12 and IFN-gamma as components of a Th1 response. Infected ICSBP-deficient mice developed fulminant, disseminated leishmaniasis as a result of failure to mount a Th1-mediated curative response, although T cells remained capable of secreting IFN-gamma and macrophages of producing nitric oxide. Compromised Th1 differentiation in ICSBP-/- mice could not be attributed to hyporesponsiveness of CD4(+) T cells to interleukin (IL)-12; however, the ability of uninfected and infected ICSBP-deficient mice to produce IL-12 was markedly impaired. This indicates that ICSBP is a deciding factor in Th responses governing humoral and cellular immunity through its role in regulating IL-12 expression. 相似文献
48.
DM Schuster 《Canadian Metallurgical Quarterly》1996,2(4):503-514
The nature of the inhibition of camel retina acetylcholinesterase (AChE) activity by tetrahydro-aminoacridine (THA, tacrine) has been investigated in the present study. The non-significant change of the percent inhibition of AChE by THA with respect to various lengths of the preincubation period showed the type of the reversible inhibition. THA reversibly inhibited AChE activity in a concentration dependent manner; IC50 was 0.23 microM while the IC100 was 14.22 microM. The K(m) for the hydrolysis of acetylthiocholine iodide was found to be 62.6 microM in the control system; a value increased in the THA treated systems. The Vmax was 0.472 mumole/min/mg protein for the control system, while it decreased in the THA treated systems. Dixon, as well as Lineweaver-Burk, plots and their secondary replots indicated that the nature of the inhibition is of the linear mixed type, which is considered to be a partial competitive and pure non-competitive mixture. The values of Ki(slope) and K'i(intercept) were estimated as 0.068 microM and 0.181 microM, respectively. The K'i was greater than Ki indicating that THA has a greater affinity of binding for the peripheral site than the active site of the camel retina AChE. The use of camel retina as a good experimental animal model may open new avenues for studying acetylcholine and AChE metabolism. 相似文献
49.
The physical process of jamming could take architectural sustainability/recyclability to a whole new level. It involves achieving structural rigidity through the crowding of particles within a confined space, rather than by permanent bonding. Project Z-Form, a collaboration between a team of physicists from the JaegerLab at the University of Chicago – including PhD students Kieran Murphy and Leah Roth and professor Heinrich Jaeger – and artist Dan Peterman , sets out to develop a pourable material that not only self-supports but can also bear loads. Here they explain the project and the concepts behind it. 相似文献
50.
D Kammerer-Doak K Baurick W Black DM Barbo HO Smith 《Canadian Metallurgical Quarterly》1996,63(1):133-137
BACKGROUND: Germ cell tumors, the most common ovarian malignancies in females under the age of 21, are rare in older women. We report an unusual case of a mixed embryonal carcinoma and endodermal sinus germ cell tumor in a perimenopausal patient and review the differential diagnosis and management of these malignancies with respect to age. CASE: A 53-year-old woman complaining of irregular menses and pelvic pain was found to have a large pelvic mass and a positive pregnancy test. Subsequent investigation revealed a large left adnexal mass, and an elevated beta-HCG and alpha-AFP. At laparotomy, a mixed germ cell tumor was found. The patient was treated with multiagent chemotherapy and currently is without evidence of disease. CONCLUSION: Although rare, the diagnosis of germ cell tumor should be considered in older women presenting with a large pelvic mass. The treatment and prognosis is similar regardless of age, except that reproductive-sparing surgery is not a priority in the older patient. 相似文献