Dietary polyamines promote the growth of azoxymethane-induced aberrant crypt foci in rat colon

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.      

Immunological aspects of laboratory diagnosis of chronic urticaria

High prevalence of allergic diseases necessitates search for new methods of laboratory diagnosis thereof. We studied the diagnostic significance of the count of cells expressing low-affinity receptors to IgE (CD23+ cells) and compared this test with skin tests with non-infectious allergens and measurement of total serum IgE. 104 patients with various forms of chronic relapsing urticaria were examined. The count of CD23+ cells was markedly increased in atopic urticaria. The increase in the count of these cells and correlation with the results of skin test were less expressed in infectious allergic urticaria. In other forms of chronic urticaria characterized by negative results of skin tests the count of CD23+ cells was normal. The level of total serum IgE was low virtually in all patients. Hence, the count of cells carrying low-affinity receptors to IgE is highly informative, detecting IgE-mediated reactions in the patients, though this parameter does not allow identification of the allergen. This test can be used in complex with other methods of allergodiagnosis, particularly in cases when skin tests are for this or that reason impossible.     

Fast detection of DNA of hepatitis B virus by real time PCR

90 blood plasma samples from patients with suspected chronic viral hepatitis B (CVHB) were analyzed by real-time polymerized chain reaction (PCR). The findings were compared with the results obtained by 2 PCR electrophoresis-based test-systems; the sensitivity limit for the quantification of DNA of hepatitis B virus (HBV) was determined; in the present case, the limit corresponded to 30 replications of HBV DNA to reaction (600 GE/ml). The positive result of real-time PCR was registered in 53.3% of cases. The quantity of HBV DNA replications in blood plasma samples varied from 30 to 3.9 x 10(6) per reaction (600-7.8 x 10(7) GE/ml). Serological profiles were analyzed in 18 patients with the verified diagnosis of CVHB. HBV DNA was detected in blood of 65% of HBsAg(+)-patients. The markers of HBeAg replication were noted in 35.5% of patients; it is noteworthy, that HBeAg(+)-samples were characterized by a higher level of viral loads (> or = 10(6) GE/ml) versus HBeAg(-)-samples (> or = 6 x 10(3) GE/ml). An analysis of blood-plasma samples dynamically obtained from one patient with chronic renal insufficiency and CVHB showed a decreased level of viral load from 1.7 x 10(7) GE/ml to a negative finding of real-time PCR registered after a therapy course by zeffix. Hence, the automated and standardized real-time PCR, when used at a multi-field patient-care facility, ensures a better diagnosis of viral hepatitis B.     

Evasin‐3‐like anti‐chemokine activity in salivary gland extracts of ixodid ticks during blood‐feeding: a new target for tick control

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.     

RT-PCR-based evaluation of the activity of human papilloma virus infection in relapsing papillomatosis of the larynx

RT-PCR-based examination of papilloma samples obtained from patients with relapsing papillomatosis of the larynx showed an incidence rate of human papilloma virus (HPV) amounting to 89%. The viral load level of the studied samples, when measured by concurrent RT-PCR HPV, differed by more than 130 times. It made, in the untreated patient, 1.2 x 10(9) hormonal equivalents/ml, i.e. 13-fold higher versus the patient who received pathogenetic therapy. Thus, the approach in question provides for a possibility to monitor the activity of papilloma viral infection and to evaluate the efficiency of different variations of pathogenetic therapy because the "classic" variant of PCR-detection is not informative in the discussed case.