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Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon 总被引:1,自引:1,他引:1
We have examined whether dietary polyamines influence the formation and
initial growth of azoxymethane (AOM)-induced aberrant crypt foci (ACF) in
rat colon. Effects of a combination of dietary polyamines at three dose
levels (putrescine: 50, 280, 740 nmol/g; spermidine: 10, 261, 763 nmol/g;
spermine: 1, 31, 91 nmol/g) in the polyamine-poor AIN-76A diet were studied
in animals in two different experimental situations: animals treated with
AOM alone and animals treated with AOM + difluoromethylornithine (DFMO), a
specific inhibitor of endogenous polyamine synthesis. In both experimental
situations, dietary polyamines enhanced the growth of ACF, expressed as the
number of large ACF (foci with three or more aberrant crypts, ACF > or =
3), whereas the formation of ACF, expressed as the number of ACF, was
apparently not altered. In animals treated with AOM alone, maximal growth
enhancing effect on ACF was nearly obtained with the median level of
dietary polyamine. In rats fed a low polyamine diet, basic AIN-76A, DFMO
reduced the growth of AOM-induced ACF by 83%. This inhibitory effect of
DFMO was counteracted by dietary polyamines in a dose- dependent manner,
and it was abolished at the highest level of polyamines. In conclusion, it
was demonstrated that dietary polyamines are able to enhance the growth of
AOM-induced ACF. Further, dietary polyamines reversed the DFMO-caused
inhibition of ACF growth, probably by compensating for the DFMO-reduced
endogenous polyamine synthesis.
相似文献
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V T Za?tsev B I Peev I A Krivoruchko A V Maloshtan I V Sarian C A Pavlichenko 《Klinichna khirurhiia / Ministerstvo okhorony zdorov'ia Ukra?ny, Naukove tovarystvo khirurhiv Ukra?ny》1991,(9):29-32
The results of surgical treatment of 853 patients with obstructive jaundice of non-tumor genesis and initial bilirubin level in the blood of 100 mumol and higher are analysed. Individualization of therapeutic-tactical approach with the use of preoperative diagnosis of the level of obstruction of the bile ducts and severity of the state of a patient, and as well their preoperative decompression with the use of endoscopic methods permit to accomplish a number of measures aimed at reduction of the incidence of purulent-necrotic complications and lethality, improve the long-term results of treatment of the patients with obstructive jaundice. 相似文献
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N F Driuk Iu E Polishchuk L N Pavlichenko G B Dobroslav 《Klinichna khirurhiia / Ministerstvo okhorony zdorov'ia Ukra?ny, Naukove tovarystvo khirurhiv Ukra?ny》1989,(3):18-22
On the basis of the evaluation of a clinico-roentgenologic picture, the classification of occlusive-stenotic lesion of the vessels of the lower extremities is suggested. Transplantation for the crus and foot vascularization of the omental flap in 28 cases, and musculocutaneous flap--in 14 permitted to save an extremity more than in 70% of patients with the terminal stage of ischemia. 相似文献
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Grigorian AS Gilerovich EG Pavlichenko NN Kruglyakov PV Sokolova IB Polyntsev DG 《Bulletin of experimental biology and medicine》2011,150(4):551-555
We studied the effect of various methods of transplantation of mesenchymal stem cells on neuronal survival in rat brain 1
and 6 weeks after severe traumatic brain injury. It was found that intracerebral and systemic transplantation of mesenchymal
stem cells improves neuronal survival in the piriform cortex of the contralateral hemisphere without affecting neuronal survival
in the marginal zone of the traumatic cavity and amygdaloid nuclei. Intracerebral transplantation of mesenchymal stem cells
increases the content of the astroglial component of the scar in the borderline zone of the traumatic cavity. 相似文献
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Pavlichenko OV Shishkin AN Stepanova EV Dubovaya TK Krasil'nikov MA 《Bulletin of experimental biology and medicine》2006,142(4):474-477
We studied the role of VEGF signal pathway in autocrine regulation of tumor cell growth and survival under conditions of hypoxia.
Hypoxia-resistant CaOv/H substrain with high level of VEGF-A secretion was obtained by long-term culturing of CaOv ovarian
adenocarcinoma cells with CoCl2 (hypoxia inductor). VEGF-A directly participates in autocrine regulation of CaOv cell growth, including the maintenance of
cell growth under conditions of hypoxia or cytostatic treatment. On the other hand, CaOv/H cells retain high apoptotic potential
and are characterized by high expression of p27Kip1 (cyclin-dependent kinase inhibitor), which attests to possible involvement of this inhibitor into the regulation of apoptotic
response of cells under conditions of hypoxia.
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Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 142, No. 10, pp. 458–461, October, 2006 相似文献
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I. VANČOVÁ V. HAJNICKÁ M. SLOVÁK P. KOCÁKOVÁ G. C. PAESEN P. A. NUTTALL 《Parasite immunology》2010,32(6):460-463
Ticks exploit many evasion mechanisms to circumvent the immune control of their hosts including subversion of the communication language between cells of the immune system provided by chemokines and other cytokines. One subversive molecule secreted in the saliva of Rhipicephalus sanguineus is Evasin‐3, a structurally unique 7 kDa protein that selectively binds the neutrophil chemoattractants, CXCL8 and (with lower affinity) CXCL1. We compared anti‐human CXCL8 and anti‐mouse CXCL1/KC activities in salivary gland extracts prepared from adult Amblyomma variegatum, Rhipicephalus appendiculatus and Dermacentor reticulatus ticks during blood‐feeding. Both anti‐CXCL8 activity and anti‐CXCL1 activity were detected in all species and in both adult females and males, with consistently higher activity levels against CXCL8. These results suggest that Evasin‐3‐like activity is common amongst metastriate ixodid tick species, and provide further evidence of the importance to ticks in controlling neutrophils during blood‐feeding. As such, Evasin‐3 offers a new target for anti‐tick vaccine development. 相似文献
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B I Peev A V Maloshtan I A Krivoruchko S A Pavlichenko I V Sarian 《Vestnik khirurgii imeni I. I. Grekova》1991,147(7-8):29-32
The employment of endoscopic methods in 399 patients for preoperative decompression of the biliary system in mechanical jaundice was analyzed. Positive and negative aspects of each of the methods were established and indications for using them were determined. 相似文献