Multiple drug resistance (MDR) of tumor cells to cytostatics is one of the most often and severe complications of chemotherapy in oncological patients. The phenomenon of MDR could be due to a sharp increase of the activity of the ATP-dependent transport proteins of the ABC system, that provides pumping of the drug from the cells to the extracellular space. Up to now, all the attempts to design agents preventing MDR were of no success. One of the prospective trends is the use of hydrophilic regulator hexapeptides. Three regulator hydrophilic hexapeptides of the linear and cyclic structure were used as the MDR modulators. The sensitivity of the tumor cells to various cytostatics in the presence of the peptides was determined by the MTT-test and the direct counting of the survived cells. The effect of the hexapeptides on MCF7, KB8-5 and PC3 cells was investigated. It was concluded that the hydrophilic hexapeptides of the linear and cyclic structure increased the sensitivity to doxorubicin (a cytostatic). The tumor cell MDR inhibition was mediated by the ATP-dependent transport protein MRP. Such a characteristic of the hexapeptides is of interest for their use as agents preventing MDR.

Efficacy of arbidol and ridostin in cupping postvaccinal complications due to variolation was studied by the clinico-virological, hematological and biochemical indices and it was shown that arbidol was efficient in cupping development of dermal complications, lowered the severity of the postvaccinal reaction and stimulated the cellular and humoral immune response. Ridostin, a high molecular interferon inductor, was highly efficient in cupping all the forms of the postvaccinal complications, including the neurological and cutaneous ones.

Resistance of 2134 clinical isolates of etiologically significant species of gramnegative bacteria to 5 beta-lactam antibiotics, i. e. cefepime, piperacillin/tazobactam, cefoperazone/sulbactam, imipenem and ceftazidime (the 3^rd generation cephalosporin) as the reference drug was investigated for the period of 5 years (2004-2008). In total, 554 strains of E.coli, 578 strains of P.aeruginosa, 255 strains of Acinetobacter spp., 161 strains of Proteus mirabilis, 359 strains of Klebsiella pneumoniae and 227 strains of Enterobacter cloacae were assayed in dynamics. The comparative analysis of the frequency of the antibiotic resistant isolates from the patients treated within 2004-2008 with often and long-term use of cefoperazom-sulbactam, meropenem and imipenem revealed an increase in development of resistance to all beta-lactams, including the inhibitor-protected ones. It least of all concerned imipenem, still isolation of 39.5% of the imipenem resistant strains of P.aeruginosa was in favour of the tendency. A dramatic 3-5-fold rise of resistance in 2007 and 2008 in the isolates of K.pneumoniae, E.cloacae and Acinetobacter spp. to both the inhibitor-protected beta-lactams, that averaged 56 and 45%, 45 and 35% and 26 and 30% respectively, deserved attention. It was assumed that the main mechanism of resistance in the isolates to the inhibitor-protected beta-lactams was hyperproduction of beta-lactamase of type CTX-M. The large part of the cefepime resistant isolates of K.pneumoniae and Acitetobacter spp. (76.8 and 62.2% respectively) was in favour of the assumption. It was concluded that periodical reversion of the policy of preventive antibiotic prophylaxis was necessary, since such a prophylaxis is a reliable barrier to development of postoperative complications and at the same time it promotes selection of nosocomial strains with some other mechanisms of antibiotic resistance under hospital conditions.

Clinical signs of acute respiratory tract viral infection and influenza in 150 patients under the standard symptomatic therapy with cycloferon, an early interferon 1 and 2 inductor are described. The patients were randomized by the body temperature on the day of the medical advise seeking. The clinical process of the respiratory tract infection was characterized by the second increase of the body temperature stated in 31.8% of the patients. By the clinical signs the infection was mixed (virus-virus) that explained the second increase of the body temperature. Normalization of the temperature was stated on the 4^th or 5^th day of the observation. The catarrhal and intoxication syndromes were observed for no more than 5 days. When the treatment was started in time (on the day of the medical advise seeking), cycloferon provided minimization of the intoxication and catarrhal syndromes and normalization of the body temperature on the 4^th day of the therapy without the use of antibacterial agents.

The use of cytoflavin solution in complex therapy of patients with neuroinfection was studied. It showed a favourable effect on the disease clinical process, evident from less pronounced intoxication and meningeal signs by the 11th day of the treatment and improvement of the liquorological picture. The cytoflavin efficacy was also confirmed by normalization of the brain bioelectric activity evident from the electroencephalograms and by reduction of the level of antioxidants, such as metalloproteids and superoxidodismutase, that was in favour of the drug antiinflammatory and antioxidant effects. The use of cytoflavin tablets during in early convalescence period promoted earlier recovery of the intellectual and mnestic reactions. On the whole, the use of cytoflavin promoted favourable process and outcomes of neuroinfections and could be recommended for the use during the acute state and re habilitation of the patients.