Measurement of investment portfolio performances

Management of investment portfolio includes technical and fundamental analysis, selection of appropriate securities, designing the optimal portfolio structure, portfolio performance measurement, monitoring and portfolio rebalancing. Investing in securities involves active, balanced or passive investment strategies. In addition, the structure of investment portfolio consists of investment securities and trading book. Investment securities include liquid part that is a secondary liquidity reserve and the income part which is held to maturity in order to achieve the greatest possible profit. Trading book are securities that are traded continuously in order to make a profit according to current price differences. Investment activities are based on information about rates of return, the degree of risk, economic forecasts and risk preferences. After creating an optimal portfolio that is on the efficiency frontier, investment managers perform ongoing monitoring by measuring performance of securities. Investment instruments and tools for evaluating portfolio performance are quite developed: Sharpe’s index, Treynor’s index, Sortino ratio, Jensen index, Modigliani alpha index, CAPM and APT. Using these indices and models, portfolio managers assess portfolio performance and redesign the portfolio structure to bring current portfolio to the efficiency frontier as close as possible. Usability of these models and techniques are in creating and maintaining an optimal investment portfolio in accordance with the preferences of investors in terms of yield and risk

Breast reconstruction by pedicled transverse rectus abdominis myocutaneous flap

Reconstruction of the amputated breast in female patients after surgical management of breast carcinoma is possible with the use of autologous tissue, synthetic implants, or by combining autologous tissue and synthetic materials. Autologous tissue provides soft and sufficiently elastic tissue which is usable for breast reconstruction and eventually obtains original characteristics of the surrounding tissue on the chest wall. The use of the TRAM flap for breast reconstruction was introduced in 1982 by Hartrampf Scheflan, and Black. The amount of the TRAM flap tissue allows breast reconstruction in the shape most adequate to the remaining breast. The possibilities of using the TRAM flap as pedicled myocutaneous flap or as free TRAM flap make this flap a superior choice for breast reconstruction in comparison with other flaps

Ultrasonographic findings validity in the identification of metastatic regional lymph nodes in patients with cutaneous melanoma

Background/Aim. Early identification of lymph node (LN) metastases has both therapeutic and prognostic significance in patients with cutaneous melanoma. Ultrasonographic (US) examination of LN morphological characteristics and US of LN morphological and vascular characteristics are diagnostic methods used in identification of regional LN metastases, thus rendering a base for lymphonododisection indication. The aim of this study was to determine validity of these two US diagnostic methods and eventual statistically significant difference between them. Methods. The study included the two groups of the patients with clinical stage III melanoma. The group I included 31 patients followed up by the use of US of LN morphological characteristics due to the fact that US findings described them only. The group II included 30 patients in whom morphological and vascular LN characteristics were followed up. The patients of both groups were examined in the Institute for Radiology, Military Medical Academy using an ultrasonographic unit type Akuson Sequoia Model 2000. After that, therapeutic and elective radical disections were performed. Sensitivity, specificity and accuracy of US examination of LN were checked by histopathological examination. Results. The presence of LN metastases in the group I was suggested by LN enlargement and its extent, while in the group II it was suggested by the ratio of LN length and width in 83.3% of the patients, echogenicity of LN center in 76.7% of the patients, LN resistance index in 73.3% of the patients, pathologic LN vascularization in 86.7%, and pathologic intranodal arborization in 83.3% of the patients. In 67.7% of the patients in the group I and in 93.3% of the patients in the group II matastatic changes of LN were diagnosed by pathohistology. A difference between validities of the two groups was statistically significant (p < 0.05). Conclusion. LN size without other US morphological and vascular characteristics of LN does not provide enough valid US finding for a reliable preoperative identification of LN with metastatic changes in patients with cutaneous melanoma

Validity of ultrasound-guided aspiration needle biopsy in the diagnosis of micrometastases in sentinel lymph nodes in patients with cutaneous melanoma

Background/Aim. Cutaneous melanoma is one of the most aggressive solid cancers, that develops local, regional and distant metastases. The presence of metastases in lymph nodes is in correlation with Breslow tumor thickness. According to various researches, in melanoma with more than 4 mm Breslow thickness, lymph node micrometastases can be found in 60-70% of cases. Sentinel lymph nodes biopsy is a diagnostic procedure for lymph node micrometastasis detection, which is necessary for disease staging. In recent studies, ultrasound-guided fine needle aspiration with cytology (US FNAC) of the sentinel lymph node was used as less invasive procedure, but is not accepted as the standard procedure. The goal of this work was to define sensitivity, specification and precision of the ultrasound-guided fine needle aspiration method in comparison with standard sentinel lymph node biopsy. Methods. After obtaining the Ethics Committee’s permission, from 2012 to 2014 a total of 60 patients with cutaneous melanoma were enrolled, and divided into three groups: group I with thin melanoma, group II with intermediate thickness melanoma and group III with thick melanoma. The presence of micrometastases in sentinel regional lymph nodes was analyzed by US FNAC. The results obtained were compared to sentinel lymph nodes biopsy (SLNB) results. The golden standard for calculating the specific, sensitive and precise characteristics of the method of US FNAC of sentinel lymph nodes was histopathologic lymph node examination of sentinel lymph nodes acquired through biopsy. Results. Detection rate of US FNAC was 0% in the group I, 5% in the group II and 30% in the group III. SLNB detection rates were: 10% in the group I, 15% in the group II, and 45% in the group III. In melanoma thicker than 4 mm, 15% of the patients were false negative by US FNAC. The sensitivity of US FNAC for all the patients was 50%: in the group I, 0%; in the group II, 33.3%; and in the group III, 66.6%. The method specificity for all examined patients was 100% and accuracy 88%: group I, 90%; group II, 90%; group III, 85%. The FNAC and SLNB micrometastasis detection rate was significantly higher in melanoma with Breslow thickness > 4 mm (group 3) in comparison to thin and intermediate thickness tumors. Conclusion. The method of ultrasound-guided fine needle aspiration of sentinel lymph nodes, according to its sensitivity, has a place in the diagnostics of micrometastasis in regional lymph nodes only in thick melanoma, but not in thin and intermediary thickness melanoma. The results must be confirmed in a larger number of patients. If this observation could be confirmed, it would rationalize treatment of patients with thick melanoma, decrease the number of operations and shorten the time to make the diagnosis