Volume 42 (2008): Issue 2 (June 2008)

Background. The purpose was to evaluate the enlargement of the Baker cyst and the significance of medial compartment knee osteoarthritis.

Patients and methods. In a period of two years we evaluated 66 patients with MRI signs of the Baker cyst and medial compartment knee osteoarthritis (median age 56 years, age range 34-84 years, 23 males and 43 females). One group was with MRI signs of the large Baker cyst and the other one with the small Baker cyst. Following graded criteria for medial compartment were used: cartilage thickness, meniscus degeneration, bone marrow oedema, effusion. Lateral compartment was normal.

Results. In the group with the large Baker cyst, 26/31 cases (84%) had medial compartment cartilage loss. Eighteen from them had associated 3^dh degree meniscal degeneration. Five/31 (16%) cases had only medial meniscus involvement. In the second group, 17/35 (48%) cases had cartilage loss, with 3^dh degree meniscal degeneration was 14 (82%). In 18/35 (52%) cases only meniscus degeneration was present, 67% had 1^st degree of meniscus degeneration. There was a statistically significant difference in the group with the distended Baker cyst between different degrees of medial meniscus degeneration.

Conclusion. The size of the Baker cyst, as a soft tissue tumour, is strongly correlated with degenerative changes of the cartilage and with the degree of meniscus degeneration on the medial compartment of the knee joint.

Background. Detailed knowledge of the ovine jugular vein anatomy and physiology is a prerequisite for proper use of sheep as teaching or an experimental model in interventional radiology.

Material and methods. Ascending and descending jugular venograms in tilted position were done in 25 sheep to evaluate the jugular vein (JV) size and anatomy of its valves.

Results. The average maximal diameter of 50 JVs was 13.34 ± 1.18 mm. Each vein contained an average of 4.36 ± 0.98 valves. All valves were competent and 96.3% were bicuspid.

Conclusions. Because of similarities between ovine JV and human femoral vein in regards to diameters, number and type of valves and function of their valves with increased central and hydrostatic pressure, the ovine JV is a good model for evaluation of creation of JV valve incompetence, percutaneous valve transplantation and evaluation of prosthetic valve devices.

Background. Epidermoids occurring within the lateral ventricles are rare. They are slow growing benign tumours, usually presented with non-specific signs of deterioration of mental functions.

Case report. Authors present a case of 49-year-old woman with epidermoid located in the frontal part of lateral ventricle. She underwent magnetic resonance imaging before the surgical treatment and the final patohistological diagnosis.

Conclusions. Suprasellar and intraventricular epidermoids are rare, but must be included in differential diagnoses as well as meningeomas, ependimomas, subependimomas and papillomas of the choroid plexus.

Background. Cancer of the head and neck represents a diverse group of malignant diseases; so far, no factor in a wide spectrum of biochemical and histological candidate-markers has yet been identified to predict reliably the natural course of the disease or its response to the therapy to be used in routine clinical practice. Among the factors that promote tumor growth and invasion, several protease systems, implemented in proteolytic degradation of extracellular matrix components, were studied, including papain-like lysosomal cysteine proteases (e.g. cathepsins B and L) and their physiological inhibitors cystatins (e.g. stefins A and B, cystatin C). The aim of the present report is to review the published studies on clinical applicability of cysteine cathepsins and their endogenous inhibitors stefins in squamous cell carcinoma of the head and neck and to present recent research results from this area conducted jointly by the Institute of Oncology Ljubljana and ENT Department of the University Medical Center Ljubljana, Slovenia.

Conclusions. According to our experience, immunohistochemical staining of cysteine cathepsins and stefins seems to be of limited value for predicting either treatment response or patients' survival. However, the results of studies on stefin A in tumor tissue cytosols should be considered hypothesis-generating and deserves further evaluation in the frame of prospective controlled multicentric clinical study.

Background. Silencing oncogenes or other genes that contribute to tumor malignancy and progression offers a promising approach to treating cancer. Specific and efficient silencing of gene expression can be achieved by RNA interference (RNAi) technology using small interfering RNA (siRNA) or short hairpin RNA (shRNA). However, a major challenge in RNAi technology is effective delivery of interfering molecules into target cells. The aim of our study was to evaluate electroporation as a perspective method for efficient in vitro transfection of LPB fibrosarcoma cells with plasmid DNA expressing shRNA.

Methods. Induction of shRNA-mediated gene silencing by electroporation was determined by fluorescence microscopy, flow cytometry and western blot analysis. The effect of electroporation conditions on cell survival and proliferation was determined by clonogenic assay.

Results and conclusions. Our results demonstrated that electroporation is a feasible and effective method for delivery of plasmid DNA expressing shRNA into cancer cells in vitro. Electrotransfection of murine LPB fibrosarcoma cells, continuously expressing green fluorescence protein - GFP (LPB_GFP), with plasmid DNA encoding shRNA-GFP, reduced GFP expression, which was determined on the protein level, as well as by measurement of GFP fluorescence intensity. A pronounced reduction in GFP expression level was detected from the second to the fifth day after treatment. Moreover, the method is easy to perform and showed low cell damaging effects, which are the most important and preferential factors for further in vivo studies.

Background. In addition to the chemotherapeutic drug being present within the tumor during electric pulse delivery, successful electrochemotherapy requires the entire tumor volume to be subjected to a sufficiently high electric field, while the electric field in the surrounding healthy tissue is as low as possible to prevent damage. Both can be achieved with appropriate positioning of the electrodes and appropriate amplitude of electric pulses.

Methods. We used 3D finite element numerical models and a genetic optimization algorithm to determine the optimum electrode configuration and optimum amplitude of electric pulses for treatment of three subcutaneous tumor models of different shapes and sizes and a realistic brain tumor model acquired from medical images.

Results. In all four tumor cases, parallel needle electrode arrays were a better choice than hexagonal needle electrode arrays, since their utilization required less electric current and caused less healthy tissue damage. In addition, regardless of tumor geometry or needle electrode configuration, the optimum depth of electrode insertion was in all cases deeper than the deepest part of the tumor.

Conclusions. Our optimization algorithm was able to determine the best electrode configuration in all four presented models and with further improvement it could be a useful tool in clinical electrochemotherapy treatment planning.

Background. The information of the overall production of major cyanobacterial cyclic peptides in a water body is essential for risk assessment and for the prediction of future development of the bloom. A procedure that gives a review of both toxic and non-hepatotoxic hydrophilic cyclic peptide production is important to evaluate the ecological conditions in the water environment and to predict the release of dangerous toxic and tumour promoting substances.

Methods. The cyclic peptides were identified on the basis of their retention times, characteristic spectra, molecular masses and biological activity. The non-hepatotoxic cyclic peptides were characterised by their inhibition of porcine pancreatic elastase, while cytotoxicity to mammalian cells was tested with the MTT test on B16 cell line.

Conclusions. The method presented gives a rapid, simultaneous assessment, preliminary identification and estimation of bioactive cyclic peptides. The synthesis of non-hepatotoxic cyclic peptides can mediate the release various toxic and otherwise biologically active substances that induce systemic genotoxicity in mammals.