In vivo transfection and/or cross-priming of dendritic cells following DNA and adenoviral immunizations for immunotherapy of cancer--changes in peripheral mononuclear subsets and intracellular IL-4 and IFN-gamma lymphokine profile.

In order to provoke an immune response, a tumor vaccine should not only maximize antigen-specific signals, but should also provide the necessary "co-stimulatory" environment. One approach is to genetically manipulate tumor cells to either secrete lymphokines (GM-CSF, IL-12, IL-15) or express membrane bound molecules (CD80, CD86). Furthermore, patient dendritic cells can be loaded with tumor-associated antigens or peptides derived from them and used for immunotherapy. Genetic modification of dendritic cells can also lead to presentation of tumor-associated antigens. Transfection of dendritic cells with DNA encoding for such antigens can be done in vitro, but transfection efficiency has been uniformly low. Alternatively, dendritic cells can also be modulated directly in vivo either by "naked" DNA immunization or by injecting replication-deficient viral vectors that carry the tumor specific DNA. Naked DNA immunization offers several potential advantages over viral mediated transduction. Among these are the inexpensive production and the inherent safety of plasmid vectors, as well as the lack of immune responses against the carrier. The use of viral vectors enhances the immunogenicity of the vaccine due to the adjuvant properties of some of the viral products. Recent studies have suggested that the best strategy for achieving an intense immune response may be priming with naked DNA followed by boosting with a viral vector. We have successfully completed a phase I and phase II clinical trials on immunotherapy of prostate cancer using naked DNA and adenoviral immunizations against the prostate-specific membrane antigen (PSMA) and phase I clinical trial on colorectal cancer using naked DNA immunization against the carcinoembryonic antigen (CEA). The vaccination was tolerated well and no side effects have been observed so far. The therapy has proven to be effective in a number of patients treated solely by immunizations. The success of the treatment clearly depends on the stage of the disease proving to be most efficient in patients with minimal disease or no metastases. A panel of changes in the phenotype of peripheral blood lymphocytes and the expression of intra-T-cell lymphokines seems to correlate with clinical improvement.

Water uptake and relaxation processes in mixed unlimited swelling hydrogels.

The rheological oscillatory test parameters have been observed for highly concentrated hydroxypropylmethyl cellulose (HPMC), carboxymethylcellulose-sodium (NaCMC) and mixed HPMC/NaCMC hydrogels obtained by swelling of matrix tablets in 0.1 mol cm(-3) HCl and pH 6.8 phosphate buffer. The mechanical spectra of the gels have been analysed using theoretical models, i.e. a generalised Maxwell model and an adapted Maxwell model, both based on Ferry and Williams approximations. The relaxation time spectra as well as the parameters characteristic of linear viscoelastic behaviour have been calculated: zero shear viscosity (eta(0)), plateau moduli (G(N)(0), G(0)' and G(0)"), zero-relaxation time (tau(0)) and mean relaxation time (θ). The mechanical spectra of mixed HPMC/NaCMC hydrogels differ considerably from those of the pure ones, the type of the spectrum depending on the two polymers' ratios. In both media, the rheological models applied define the HPMC gels as homogeneous entangled networks, and those of NaCMC and mixed HPMC/NaCMC as heterogeneous physical gels. The relationship between the kinetic constants of water penetration and the mean relaxation times suggests that the molecular relaxation controls the water uptake velocity. With all the systems tested irrespective of pH of the aqueous phase, an inversely proportional dependence between the viscosity and the water penetration velocity has been noted. Since the degree of hydration is one of the factors determining the degree and velocity of drug release from the hydrogel matrices, the relation between the kinetic parameters of water penetration and the viscosity is a characteristic indicator for the gel structure, the degree of swelling and the drug release rate.

Influence of hydrogel structure on the processes of water penetration and drug release from mixed hydroxypropylmethyl cellulose/thermally pregelatinized waxy maize starch hydrophilic matrices.

The kinetics of water penetration and molsidomine release from both hydroxypropylmethyl cellulose (HPMC) and mixed HPMC/thermally pregelatinized waxy maize starch (SDWMT) hydrophilic matrices has been examined in 0.1 mol x dm(-3) HCl (pH 1.0) and 0.06 mol x dm(-3) Na3PO4/HCl buffer (pH 6.8). The rheological oscillatory test parameters of their gel layers obtained by swelling of the matrices in the two aqueous media have been observed. The kinetic swelling properties of mixed HPMC/SDWMT hydrogels (i.e. degree and velocity of both water penetration and swelling, transport mechanism which controls solvent sorption) directly influence the drug release behaviour and the structural features of the formed gel layer. Both diffusion processes are diffusion-controlled ones, their mechanisms being influenced insignificantly by the relaxation properties of the hydrated macromolecules. It has been established by means of comparative viscoelastic analysis, that mixed HPMC/SDWMT hydrogels demonstrate the typical behaviour of 'filled' composite systems having poor adhesion between the surface of the elastic SDWMT 'filler' and the continuous HPMC phase. Due to the inter-phase relations between the swollen starch granules and the linear cellulose derivative as well as to the specific structure of amylopectin molecule, the pregelatinized waxy maize starch shows a stronger influence on the velocities of both water penetration and drug release from mixed HPMC/SDWMT matrices.

[Cytogenetic effect of thaliblastine in a culture of human peripheral blood lymphocytes]. / Tsitogenetichekii éffekt taliblastina v kul'ture limfotsitov perifericheskoi krovi cheloveka.

The mutagenicity of thaliblastine (Bulgarian potential antitumor drug) was investigated in vitro in lymphocytes from healthy donors, and in vivo in lymphocytes of oncological patients after thaliblastine administration. No increase in the rate of chromosome aberrations was noted with increasing thaliblastine concentrations in vitro and in the course of therapy in vivo. Some polyploid metaphases were found in the lymphocytes of the patients treated with thaliblastine, as a result of the statmokinetic effect of the drug. Thaliblastine exerts extraordinarily slight mutagenic effect, as compared with other cytostatics.

Changes in the plasma levels and basic pharmacokinetic parameters of digoxin used in combination with gentamicin, amiodarone and spironolactone.

Digoxin was administered intravenously (0.035 mg/kg b.w.). A prior five-day treatment with gentamicin (100 mg/kg b.w., 10 mg/kg b.w., i.m.), amiodarone (30 mg/kg b.w., s.c.) and spironolactone (10 mg/kg b.w., p.o.) caused elevation of plasma digoxin levels primarily because the alpha half-life was prolonged (t1/2 alpha). In a combined five-day application of digoxin with gentamicin (10 mg/kg b.w., i.m.), and of digoxin with amiodarone, the plasma levels of digoxin rose due to the lengthened beta half-life (t1/2 beta). In administering a combination of digoxin and spironolactone, the plasma digoxin levels dropped, t1/2 alpha decreased and t1/2 beta increased. A 15-day digoxin treatment tested combinations of digoxin, from days eight to 15, with gentamicin (10 mg/kg b.w., i.m.); with amiodarone, or with spironolactone. The digoxin level was elevated with the combinations of digoxin-amiodarone and digoxin-spironolactone: t1/2 alpha was longer in both cases, while t1/2 beta was longer only for the digoxin-amiodarone combination. No changes were found in the creatinine clearance or renal histology of experimental animals after treatment, nor were any deviations found in the values of T3, T4 and TTX.

Effect of digoxin on experimental adrenaline-induced hyperglycemia and insulin-induced hypoglycemia.

The effect of digoxin (0.035 mg/kg b.w., i.v.) on adrenaline-induced hyperglycemia (adrenaline: 50 micrograms/kg b.w., s.c.) and on insulin-induced hypoglycemia (insulin: 0.4 mU/kg b.w., s.c.) was studied in experiments on rabbits. Digoxin intensified the adrenaline-induced hyperglycemia at the 30th and 60th minutes of application. The hyperglycemia in this case subsided more rapidly. Digoxin alone caused on elevation of the blood sugar levels that was most pronounced at the 30th minute of introduction. These elevated levels fell to the initial value by the 180th minute. The blood sugar levels in the rabbits treated with physiological solution rose slightly. This was most noticeable at the 120th minute. Digoxin attenuated the insulin-induced hypoglycemia significantly at the 120th, 150th, and 180th minutes (p < 0.05). We suggest that the increase of the adrenaline-induced hyperglycemia and the attenuation of the insulin-induced hypoglycemia could be linked to the release of catecholamines in the acute stage of the action of Digitalis glycosides.

Different chemotherapy schedules in metastatic colorectal cancer: a response and survival analysis.

PURPOSE: To evaluate the response rate and overall survival (OS) of chemotherapy-naïve patients with metastatic colorectal adenocarcinoma treated with 4 different chemotherapy regimens. PATIENTS AND METHODS: One hundred fifty-eight patients with metastatic colorectal cancer (CRC) were included in this prospective study. The treatment regimens were as follows: a) Intraarterial (i.a.) chemotherapy: 5-fluorouracil (5-FU) 600 mg/m(2)/day by 120 hour-infusion, mitomycin C 8 mg/m(2) day 1, and epirubicin 80 mg/m(2) day 5, every 3 weeks, b) Intravenous (i.v.) chronochemotherapy: 5-FU 800 mg/m(2) i.v. infusion during 18.00 h-06.00h, leucovorin (LV) 100 mg/m(2) i.v. infusion during 18.00h-06.00h; and cisplatin 20mg/m(2) i.v. infusion, during 10.00h-18.00 h, all given on days 1-5, every 3 weeks, c) Scheme: 5-FU 500 mg/m(2) i.v. bolus, days 1-5, vincristine 1.2 mg/m(2) i.v. bolus, day 1, CCNU 120 mg/m(2) per so (p.o.), day 5, every 3 weeks. Scheme I was used as control group, d) Scheme II: 5-FU 425 mg/m(2) i.v. bolus, days 1-5, and LV 50 mg/m(2) i.v. bolus, days 1-5, every 3 weeks. The patients received 3-26 cycles of chemotherapy. The results taken were compared using the Kaplan-Meier life-table method, logrank test, Cox proportional hazard model, and Cox model with time-dependent covariates. RESULTS: Nine (26%) out of 34 patients with i.a. chemotherapy achieved complete response (CR), 8 (24%) partial response (PR), and 11 (32%) stable disease (SD). In the group of 42 patients with chronochemotherapy 4 (10%) achieved CR, 15 (36%) PR and 12 (28%) SD. In the group of 61 patients with conventional treatment with 5-FU and LV (scheme II) no CR was achieved with 11 (18%) patients responding partially. In the control group of treatment (scheme I) with 21 patients PR was observed in 2 (10%) patients. Patients with i.a. chemotherapy and chronochemotherapy achieved a similar OS, which was better than OS of scheme II. The survival was worst with scheme I. CONCLUSION: I.a. chemotherapy and chronochemotherapy showed an almost equivalent efficacy in terms of response rates, which were clearly superior to those achieved by schemes I and II. Also, OS was significantly better in the patients treated with i.a. chemotherapy and chronochemotherapy compared to patients treated with scheme II. The worst survival was seen in scheme I patients.

[An economical method for research on serum triacylglycerols in mass screening]. / Ikonomichen metod za izsledvane na serumnite triatsilglitseroli pri masov skrining.

A method with thin layer chromatography on alufoil of the firm "Merck" was developed for the needs of mass screening in the studies on lipid metabolism. Serum lipids extract is divided at a liquid phase benzine-diethyl ether 4:1. After carbonization, lipid spots are observed. The fourth of them is of TAG. The intensity of the spot is compared with the standard triolein. In this way the sera with hypertriglyceridemia are separated and only a small part of the mass screening (5-8%) are further studied by enzyme or other methods. In this way time and means are largely saved. Because of the small quantity of serum necessary for the investigations, the method is recommended for the pediatric practice as well.

Clinical study of the effect of the preparation DEODAN on leukopenia, induced by cytostatics.

The aim of the study is to establish the effect of the preparation DEODAN on leukopenia induced by chemotherapeutics in oncological patients. DEODAN is an oral preparation, obtained from lyzozyme lysates of Lactobacillus bulgaricus strain "I. Bogdanov patent strain tumoronecroticance B-51" ATCC 21815, called shortly LB51. In the study there are included two groups of patients--from National Oncological Centre, Sofia, the other from Clinic of Medicine, Bertha Academic Hospital, Clinics of Duisburg, Duisburg. All the patients, (78) have undergone combined chemotherapy. In all patients, leukopenia has been established in moderate and medium levels. The scheme of the application of DEODAN has been 3 g, three times a day before meals, from the first day of establishing the disturbances of the haemopoesis. The treatment lasted until the restoration of the haematological values. Only DEODAN was applied. The results obtained show that the recovery of the WBC count (values above 3000) took place in all of the patients between days 3 and 5. None of the patients displayed any infectious or febrile complications, as a result of the applied chemotherapy and the treatment with the preparation. DEODAN also improves the general condition of the patients.