Biological activity of conjugates of muramyl dipeptides with batracylin derivatives.

Antitumour activity of batracylin (BAT), muramyldipeptide (MDP) and four immunomodulatory conjugates of BAT with MDP were evaluated in the study. The activity was assessed using viability tests performed in the cultures of tumour cell lines of different tissue origin such as WEHI 164 (fibrosarcoma), K562 (leukaemia), and Ab (melanoma), populations of immune cells isolated from peripheral blood, and the tumour cells mixed with immune cells. An intensity of cell death caused by the analogues was measured using flow cytometry analysis as subG1 peak and the distinction between necrotic and apoptotic DNA cleavage during cell death was performed using DNA fragmentation assay. The compounds 11c, 11e and 11h managed to kill WEHI 164 cells in the presence of immune cells in apoptotic manner while BAT and conjugate 11a caused necrosis at the same time. Necrotic pattern of DNA cleavage was also noted in all cultures containing K562 and Ab cells. BAT and MDP caused necrosis in the cultures of pure immune cells, while the conjugates did not affect these cultures at all. Surprisingly, some analogues increased viability of K562 and Ab cells. Low toxicity and ability to induce apoptosis suggested usefulness of some analogues, mainly 11c, as antitumour drugs in limited range of tumours of certain tissue origin, such as WEHI 164.

Immunomodulating effect of influenza vaccination in the elderly differing in health status.

The aim of this study was to analyse whether split influenza vaccine may elicit NK cytotoxic response in the vaccinated elderly people and whether this effect may be maintained over few weeks after vaccination. It was also worth investigating the relation between NK activity in the vaccinated and specific immune protection against influenza and non-specific against other infections. Two groups of volunteers were vaccinated with trivalent split viron influenza vaccine in two consecutive seasons (1999/2000; 2000/2001). The elderly group consisted of 142 people (65-92 years old) in the first season and 110 in the second; while the young (16-44 years old) of 98 and 67 people, respectively. An analysis of NK cytotoxic activity had been done before vaccination, two days, one month and fifth months thereafter. The results revealed that vaccination with the influenza vaccine had an augmenting effect on NK activity, in all groups examined, in both epidemic seasons, visible at two days and 1 month after the vaccination. In the elderly high pre- and post-vaccination NK activity was related to higher titers of anti-hemagglutinin, better health status and lower incidence of all cause respiratory tract infections. At the second vaccination, most of the elderly with chronic medical conditions and high NK activity, who did not attain the protective level of anti-hemagglutinins in the first season, converted into the protected. High pre- and post-vaccination NK activity predisposes elderly people to the protective humoral anti-hemagglutinin response and gives better protection from respiratory tract infections.

Complete remission of Bomirski Ab amelanotic melanoma in hamsters treated with the angiogenesis inhibitor TNP-470.

The growth of solid tumors and their metastasis is dependent on the development of new blood vessels (angiogenesis). In our previous studies it was found that angiogenesis inhibitor TNP-470 acting systematically can decrease the rate of growth of transplantable Bomirski Abmelanoma in hamsters. In this study we applied TNP-470 (30 mg/kg) peritumorally from the day when tumor was palpable over 10 days, once daily. Animals were killed 6 months later and examination by autopsy and histological preparations showed the complete remission of transplanted tumor and the lack of metastasis. Thus, Ab melanoma can be effectively cured with TNP-470 angiogenesis inhibitor when the substance is applied locally.

Luteal phase of the menstrual cycle in young healthy women is associated with decline in interleukin 2 levels.

The aim of this study was to look at the possible changes in the blood levels of Interleukin 2 (IL2) during the sexual cycle in generally healthy, young, regularly menstruating women. The concentrations of progesterone and 17beta-estradiol were measured using radioimmunological assay. The bioactivity of interleukin 2 was measured using a biological test on the IL2-sensitive CTLL cell line. The percentage of lymphocytes with intracellular IL2 was determined by flow cytometry. Eighteen healthy volunteers (19-29 years old) were examined on days 5, 8, 14, 18 and 25 of the same cycle. All women were characterised by a regular menstrual cycle as per physiological levels of 17beta-es-tradiol and progesterone. The luteal phase of the cycle was characterised by both a decrease of IL2 blood levels and a decrease in the percentage of intracellular 1L2-containing lymphocytes stimulated in vitro. The IL2 level fluctuations observed during the menstrual cycle may be one factor causing pre-menstrual infections observed in young women. On the other hand, the decrease of IL2 may be seen as a start of the immune suppression necessary for an embryo's nidation.

Synergistic effect of the angiogenesis inhibitor TNP-470 and tumor necrosis factor (TNF) on Bomirski Ab melanoma in hamsters.

Bomirski Ab transplantable melanoma bearing hamsters were treated with angiogenesis inhibitor TNP-470 or with rat tumor necrosis factor (TNF) at doses of 20 micrograms and 40 micrograms or with both TNP-470 and TNF at a dose of 20 micrograms each. The size of the growing tumor was measured everyday from the day when it was palpable. After the death of the animals the final size of their tumors was measured and the number and localisation of metastasis were determined. It was found that the rate of tumor growth was lowest in the group of animals treated with TNF at a dose of 40 micrograms and in the group of animals treated with TNP-470 and TNF at a dose of 20 micrograms. The frequency of metastasis was different in the experimental groups although their location was similar. The longest living animals belonged to the group treated with both TNP-470 and TNF. The results of the investigation indicate that TNP-470 and TNF act in a synergistic way that allows a decrease in the effective dose of TNF thus diminishing its noxious side effects.

Suppression of growth of Bomirski Ab melanoma and its metastasis in hamsters by angiogenesis inhibitor TNP-470.

The growth of solid tumors and their metastasis is dependent on the development of new blood vessels (angiogenesis). In this study, we examined the effect of the angiogenesis inhibitor TNP-470 on a fast growing melanoma in hamsters. The effect was observed both on tumor growth and metastasis. Treatment with TNP-470 caused a significant decrease in the rate of tumor growth and suppression of the development of metastasis in 63% of treated animals. Some of the hamsters treated with TNP-470 had the tumor excised and the effect of that operation on the development of metastasis was examined. In such cases the inhibitory effect of TNP-470 was weaker than in tumor bearing animals. This indicates that excision of tumor created more favourable conditions for angiogenesis and that the dose of TNP-470 should be increased to be effective in such conditions.