[DNA mapping in the capsid of giant bacteriophage phiEL (Caudovirales: Myoviridae: Elvirus) by analytical electron microscopy].

INTRODUCTION: Giant phiKZ-like bacteriophages have a unique protein formation inside the capsid, an inner body (IB) with supercoiled DNA molecule wrapped around it. Standard cryo-electron microscopy (cryo-EM) approaches do not allow to distinguish this structure from the surrounding nucleic acid of the phage. We previously developed an analytical approach to visualize protein-DNA complexes on Escherichia coli bacterial cell slices using the chemical element phosphorus as a marker. In the study presented, we adapted this technique for much smaller objects, namely the capsids of phiKZ-like bacteriophages. MATERIAL AND METHODS: Following electron microscopy techniques were used in the study: analytical (AEM) (electron energy loss spectroscopy, EELS), and cryo-EM (images of samples subjected to low and high dose of electron irradiation were compared). RESULTS: We studied DNA packaging inside the capsids of giant bacteriophages phiEL from the Myoviridae family that infect Pseudomonas aeruginosa. Phosphorus distribution maps were obtained, showing an asymmetrical arrangement of DNA inside the capsid. DISCUSSION: We developed and applied an IB imaging technique using a high angle dark-field detector (HAADF) and the STEM-EELS analytical approach. Phosphorus mapping by EELS and cryo-electron microscopy revealed a protein formation as IB within the phage phiEL capsid. The size of IB was estimated using theoretical calculations. CONCLUSION: The developed technique can be applied to study the distribution of phosphorus in other DNA- or RNA-containing viruses at relatively low concentrations of the element sought.

[Effect of jerusalem artichoke extract on the functioning of malate dehydrogenase in the liver of rats with alloxan diabetes]. / Vliianie ékstrakta topinambura na funktsionirovanie malatdegidrogenazy v pecheni krys pri alloksanovom diabete.

An increase in the activity and the appearance of a new isoform of NAD-dependent malate dehydrogenase (MDH; EC 1.1.1.37) has been detected in the liver of rats with alloxan diabetes was revealed. This confirms the possibility of MDH involvement in the adaptive reaction of the body under oxidative tress caused by biochemical changes in diabetic animals. The increase in the hepatic MDH activity in rats with experimental type I diabetes mellitus (T1DM) is associated with the formation of an additional MDH isoform in peroxisomes. Data on the expression of the MDH encoding genes mdh1 and mdh2 confirm that in T1DM the increase in MDH activity occurs at the level of transcription of MDH encoding genes. The use of the extract of Helianthus tuberosus led to a marked decrease in the blood glucose concentration of rats with alloxan diabetes, abolished by the change in transcriptional activity of the studied genes and blocked the formation of new MDH isoforms in rats with experimental alloxan diabetes. This suggest that extract of H. tuberosus may be of considerable interest from the point of view of pharmacological correction of metabolic changes during the development of pathologies of this kind.

[Regional chemotherapy in treatment of patients with unresectable liver metastases of uveal melanoma].

PURPOSE: Retrospective efficacy analysis of transcatheter arterial treatment for unresectable liver metastases of uveal melanoma. MATERIALS AND METHODS: There were performed 38 courses: hepatic arterial chemoembolization with Lipiodol (HACE, n 9) and combination of HACE with hepatic artery infusion (HAI, n = 29). In 9 patients we used the following chemotherapeutic agents: doxorubicin (10-50mg), carboplatin (150 to 450 mg), dacarbazine (200-400mg), mustophoran (360-624mg) and mitomycinum C (5-10mg). RESULTS: There were no mortality or serious complication. According to mRECIST, partial response, stabilization and progression of liver metastases was seen in 1, 3 and 5 patients, retrospectively. The mean survival after arterial treatment was 9,4 (2-34) mo. The 6-, 12- and 18- mo survival rates were 56%, 22% and 11% respectively. CONCLUSION: Transcatheter therapy in unresectable liver metastases of uveal melanoma is safe and can prolong survival of selected patients up to 34 mo.