Assessing structural and functional plankton responses to carbendazim toxicity

A model ecosystem experiment was conducted to investigate the ability of an in situ Daphnia magna feeding bioassay to assess impairment of ecosystem function. Animals were deployed in model ecosystems dosed with different concentrations of the fungicide carbendazim, and effects on the postexposure feeding rate of D. magna were compared with effects on zooplankton species richness (ecosystem structure) and development of phytoplankton biomass (ecosystem function). In the medium-dosed systems (21 microg/L), a structural change was observed within the zooplankton community, but no indirect effects on phytoplankton development were detected. It appears that at this treatment level, functional redundancy was sufficient to prevent functional impairment despite species loss. The feeding assay did not show any response at this concentration. In the high-dosed systems (221 microg/L), structural changes in the zooplankton community were accompanied by increased development of phytoplankton biomass. The feeding bioassay also showed a significant response at this concentration. At the high treatment level, species loss resulted in functional impairment, indicating that at this level, functional redundancy could not compensate for loss of individuals. The D. magna feeding bioassay matched well with the functional response (i.e., the indirect effects on phytoplankton) in the dosed systems but not with the more subtle effects on zooplankton community structure. These results lend positive support to the use of in situ feeding bioassays in combination with structural indices, such as species richness, to assess the effects of stress on ecosystem functioning in a direct way.     

ABL-kinase domain point mutation as a cause of imatinib (STI571) resistance in CML patient who progress to myeloid blast crisis

Imatinib mesylate (STI571) is a major therapeutic advance for the management of chronic myeloid leukaemia (CML), however, a proportion of patients are refractory to it, particularly those in more advanced phases of CML. Different mechanisms of resistance to imatinib are suggested, including point mutations within ABL-kinase domains. A point mutation leading to substitution at the ATP binding site of ABL-kinase and insensitivity to imatinib was detected in our patient treated with imatinib, who progressed to blast crisis. Additionally, clonal evolution could lead to BCR–ABL-independent proliferation. Early detection of ABL-kinase mutation could predict the progression of CML treated with imatinib.     

Potentiated antitumor effects of interleukin 12 and interferon alpha against B16F10 melanoma in mice

Systemic administration of cytokines has not found broad application in cancer immunotherapy due to its toxicity and lack of effectiveness in a broad spectrum of tumors. Among the most promising cytokines used often in pre-clinical and clinical trials are interferon alpha and interleukin 12. We have shown in our study that combining IL-12 with IFN-alpha in a dose which alone does not show antitumor activity results in potentiated antitumor effects without inducing toxicity.     

Antitumor activity of tributyrin in murine melanoma model

Butyric acid has been known to inhibit growth and to induce differentiation of a variety of tumor cells. Butyrate-treated tumor cells have also been observed to undergo apoptosis. Although butyrate compounds have demonstrated antitumor activity in murine tumor models and have already been admitted to clinical trials in tumor patients, the exact mechanism of their antitumor effects has not been elucidated. The results of our study showed antitumor activity of tributyrin, a butyric acid prodrug, in murine melanoma model and are strongly suggestive that antiangiogenic effects could participate in antitumor effects of butyrate compounds in vivo.     

Opposite effect of donor-specific immunization by blood or splenocytes on the survival of heart tissue transplants in strong versus weak histoincompatible combination in mice

Recipients of allogeneic heart tissue were pretreated intravenously with blood or injected intraperitoneally with spleen cells. In H-2 incompatible donor-recipient combination (BALB/c----CBA/H) donor-specific immunization, both with blood and spleen cells, resulted in acceleration of graft rejection. On the other hand, increase in graft survival was observed following donor-specific but not third-party blood pretreatment in mice compatible in H-2 complex but bearing different minor histoincompatible antigens (BALB/c----DBA/2).     

Synthesis and pharmacological properties of derivatives of alpha-amino-beta-(p-chlorobenzoyl)-propionic acid and alpha-amino-gamma-(p-chlorophenyl)-tetrahydrofuran-2-one.

Several new alpha-aminoderivatives of gamma-(p-chlorophenyl)-tetrahydrofuran-2-one were synthesized. alpha-Aminoderivatives of beta-(p-chlorobenzoyl)-propionic acid 2-13 were used as the substrates. After the reduction with NaBH4 at 10-12 degrees C and cyclization the compounds were converted into the appropriate derivatives of tetrahydrofuran-2-one 16-26. In pharmacological tests compounds 9 and 26 abolished the aggressiveness in isolated mice while compound 8 showed antiinflammatory activity.     

Large complex odontoma of the left maxillary sinus

Odontomas as a group are the most common odontogenic neoplasms. They are mixed lesions containing fully formatted dental tissues, both epithelial and mesenchymal, and are usually found during a routine radiographic examination or as a factor in noneruption. Odontomas can be divided into two types: the complex and the compound odontoma. Both types are composed of enamel, dentin, cementum and pulp tissues, but in complex odontomas the tissues are arranged in a haphazard fashion with no discernible dental structures, whereas in compound odontomas the dental tissues exist in a more regular pattern so that the lesion consists of tooth-like structures. We report a case of a 23-year-old man with a large complex odontoma involving the left maxilla and maxillary sinus with clinical, radiographic and histological findings. Because of the size of the mass and its clinical course, benign neoplasms were considered in the differential diagnosis. Surgery was the treatment of choice, and recurrence of the lesion is not expected.