排序方式: 共有32条查询结果,搜索用时 0 毫秒
1.
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
2.
3.
4.
Rossiev VA Makarov SV Aleksandrova IIa Dolgikh GT Lipshina SR Stukalova TA Trushina OA Fedorova EIu Lipina LN Sivak VF Korenev PP Murashov BF 《Terapevticheski? arkhiv》2002,74(7):35-38
AIM: To assess efficiency of immunosuppressive therapy and subsequent autologous transplantation of stem blood cells (SBC) in patients with multiple sclerosis. MATERIAL AND METHODS: The trial enrolled 23 patients (4 men and 19 women) with multiple sclerosis (MS) lasting for 3 to 12 years. The age of the patients ranged from 18 to 44 years. The index of the progression was above 1 in all the patients. A remitting, primary-progredient, secondary-progredient course was diagnosed in 3, 3 and 17 patients, respectively. Posttransplantation follow-up was 1 to 1.5 years. The degree of the neurological deficiency (0-6 scores) was estimated by the scale of functional systems damage. Lymphocyte subpopulations were evaluated by enzyme immunoassay according to expression of membrane antigens CD3, CD4, CD8, CD16, CD20, CD25, CD56, CD95 using monoclonal antibodies ICO (Biomedspectr), humoral immunity--by serum levels of IgA, IgM and IgG. SBC mobilization was conducted for 5 days by subcutaneous introduction of neipogen (Roche) in a dose 8.7-10 mcg/kg. Preparation of SBC was made on Haemonetics blood separator on mobilization day 4-5. Cryopreservation was carried out in programmed freezer (Cryomed) with 7% dimethylsulphoxide as a cryoprotector. Pretransplantation conditioning was conducted according to the schemes BEAM + antilymphocytic globulin (protocol N 1) and fludar + melfalan + ALG (protocol N 2). RESULTS: In posttransplantation period most of the patients achieved a fall in intensity of motor and coordination disorders. No recovery of cranial nerve function was observed. The protocols of pretransplantation preparation were compared by efficiency and organic toxicity. CONCLUSION: Indications to immunosuppressive therapy in MS patients were defined, pathogenetic validation of the immunosuppressive therapy was attempted. 相似文献
5.
6.
M. A. Berger B. Ia. Stukalova V. S. Mitrofanov 《Bulletin of experimental biology and medicine》1958,45(3):343-346
Summary Synthetic dl-cycloserine obtained at the Institute of Pharmacology and Chemotherapy of the USSR Academy of Medical sciences was tested in experiments in vitro. It was demonstrated that this preparation has a wide antimicrobic range of action towards gram positive, as well as towards gram negative microbes, such asB. typhi abdominalis,B. paratyphi A et al.Dl-cycloserine has a bacteriostatic effect toward various strains of mycobacterium tuberculosis which are sensitive or resistant to streptomycin, phthivazid and PAS.It was revealed that this preparation does not show any significant chemotherapeutic effect in experimentally indiced hematogenic tuberculosis in mice and tuberculosis in guinea pigs. However, its toxicity in prolonged administration to guinea pigs is very low. If kept in a thermostat during 8–10 days at a temperature of 37°C the preparation is inactivited by 25 to 30%.Presented by Active Member of the Acad. Med. Sci. USSR V. V. Zakusov 相似文献
7.
8.
9.
10.
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