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1.
Both macrophages and NK cells have been suggested to play a role in recognizing and eliminating early, in situ neoplasms. Therefore we studied the effect of inhibitors of macrophage and/or NK cell function on the take of transplantable spontaneous murine tumors in syngeneic mice. The treatment of animals with trypan blue, a selective inhibitor of macrophage function, decreased considerably the period of latency of BSP3 adenocarcinoma; however, it did not increase the take of SP4, SP82 and SP84 adenocarcinomas. The treatment of recipients with neutral red, a selective inhibitor of NK cell function, enhanced the take of SP4 adenocarcinoma. The treatment of mice with agents depressing both macrophage and NK cell function (silica or carrageenan) decreased the both macrophage and NK cell function (silica or carrageenan) decreased the period of latency and/or increased the take of SP4, SP82 and SP84 adenocarcinomas. Carrageenan or a combined treatment with both trypan blue and neutral red also enhanced the take of BaF1, a benzo(a)pyrene-induced fibrosarcoma. We concluded that both macrophages and NK cells may function as effector cells of an antitumoral surveillance system. 相似文献
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The development of cancer cachexia is perhaps the most common manifestation of advanced malignant diseases and has been recognized as a poor prognostic sign. The abnormalities associated with the condition include progressive weight loss, anorexia, asthenia, and anemia. The degree of cachexia is inversely correlated with the survival time of the patient and always implies a poor prognosis. Currently there is no established mechanism for cancer cachexia, but the severe metabolic disturbances and marked alterations in carbohydrate, lipid, and protein metabolism in the host finally lead to an increased energy deficiency. Weight loss, the key feature of cachexia, is due to a reduction of food intake, an increase in energy expenditure, or a combination of the two. A variety of changes in nutrient metabolism have been described in patients with cancer cachexia. Patients frequently exhibit a relative glucose intolerance and insulin resistance with increased activity of the Cori cycle. The cancer-bearing state affects protein synthesis and breakdown in different tissues of the body in a different manner. An acute-phase protein response can be presented in a significant proportion of patients with cancer with disease progression. A variety of proinflammatory cytokines appears to play a role in aspects of cachexia and a complex network of cytokines in combination with other factors might be involved. Aside from potential humoral mediators of cachexia, tumor-derived biologically active molecules have been reported recently. 相似文献
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Potent inhibition of HIV-1 entry by (s4dU)35 总被引:2,自引:0,他引:2
Horváth A Tokés S Hartman T Watson K Turpin JA Buckheit RW Sebestyén Z Szöllosi J Benko I Bardos TJ Dunn JA Fésüs L Tóth FD Aradi J 《Virology》2005,334(2):214-223
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Genetic variants of homocysteine metabolizing enzymes and the risk of coronary artery disease 总被引:2,自引:0,他引:2
Janosíková B Pavlíková M Kocmanová D Vítová A Veselá K Krupková L Kahleová R Krijt J Kraml P Hyánek J Zvárová J Andel M Kozich V 《Molecular genetics and metabolism》2003,79(3):167-175
It is unresolved whether elevated homocysteine in coronary artery disease (CAD) is the cause of arteriosclerosis or its consequence. In contrast, genetic variants of enzymes that metabolize homocysteine cannot be altered by arteriosclerosis. Consequently, their association with CAD would permit to imply causality. We modeled by regression analysis the effect of 11 variants in the methionine cycle upon CAD manifestation in 591 controls and 278 CAD patients. Among the examined variants only the carriership for the c.844ins68 in the cystathionine beta-synthase (CBS) gene was associated with a significantly lowered risk of CAD (OR=0.56; 95% CI=0.35-0.90 in the univariable, and OR=0.41, 95% CI=0.19-0.89 for obese people in the multivariable analysis, respectively). Healthy carriers of the c.844ins68 variant exhibited, compared to the wild type controls, significantly higher postload ratios of blood S-adenosylmethionine to S-adenosylhomocysteine (61.4 vs. 54.9, p=0.001) and of plasma total cysteine to homocysteine (8.6 vs. 7.3, p=0.004). The changes in these metabolites are compatible with an improved methylation status and with enhanced activity of homocysteine transsulfuration. In conclusion, the coincidence of clinical and biochemical effects of a common c.844ins68 CBS variant supports the hypothesis that compounds relating to homocysteine metabolism may play role in the development and/or progression of CAD. 相似文献
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Stringer WW Whipp BJ Wasserman K Pórszász J Christenson P French WJ 《European journal of applied physiology》2005,93(5-6):634-639
Published literature asserts that cardiac output (=O2×1/C(a-v)O2) increases as a linear function of oxygen uptake with a slope of approximately 5–6 during constant work rate exercise. However, we have previously demonstrated that C(a-v)O2 has a linear relationship as a function of O2 during progressively increasing work rate incremental exercise. Therefore, we hypothesized that may indeed have a non-linear relationship with respect to O2 during incremental, non-steady state exercise. To investigate this hypothesis, we performed five maximal progressive work rate exercise studies in healthy human subjects. was determined every minute during exercise using measured breath-by-breath O2, and arterial and pulmonary artery measurements of PO2, hemoglobin saturation, and content. was plotted as a function of O2 and the linear and non-linear (first order exponential and hyperbolic) fits determined for each subject. Tests for linearity were performed by assessing the significance of the quadratic terms added to the linear relation using least squares estimation in linear regression. Linearity was inadequate in all cases (group P<0.0001). We conclude that cardiac output is a non-linear function of O2 during ramp-incremental exercise; the pattern of non-linearity suggests that while the kinetics of are faster than those of O2 they progressively slow as work rate (and O2) increases. 相似文献
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Helmut Seidel Ralph Blüthner Janos Martin Gerhard Menzel Rudolf Panuska Peter Ullsperger 《European journal of applied physiology》1992,65(4):376-382
Summary Auditory event-related brain potentials (ERP) in response to two different tone stimuli (1.1 kHz or 1 kHz, 80 dB, 50 ms; given by headphones at a regular interstimulus interval of 5 s with a probability distribution of 70:30) were recorded from 12 healthy male subjects (Ss) during four different conditions with two repetitions: A - 60 dBA white noise (wN), no wholebody vibration (WBV); B - 60 dBA wN plus sinusoidal WBV in the az-direction with a frequency of 2.01 Hz and acceleration of 2 m ·s–2 root mean square; C - 80 dBA wN, no WBV; D - 80 dBA wN plus WBV. Each condition consisted of two runs of about 11 min interrupted by a break of 4 min. During the break with continuing exposure, but without auditory stimuli, Ss judged the difficulty of the tone-detection task and intensity of noise by means of cross-modality matching (CMM). Vibration-synchronous activity in the electrocardiogram was eliminated by a subtraction-technique. Noise caused an attenuation of the N1 and P2 amplitudes and prolongation of P3 latencies. The WBV did not cause systematic ERP effects. Condition B was associated with higher N1 and smaller P3 amplitudes. The factor condition had a significant effect on the peak latencies of P3 to target stimuli and the task difficulty judged by CMM. Both effects exhibited significant linear increases in the sequence of conditions A, B, C, D. For the evaluation of exposure conditions at work, it can be suggested that noise has a strong systematic effect which can be enhanced by WBV. The P3 latency is considered as an advantageous measure for the detection of objective effects of physical environmental factors, correlating with relevant subjective responses. 相似文献
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