Zmiany właściwości elektrycznych tkanki neoplazmatycznej u pacjentów z chorobą nowotworową

Malnutrition is a common condition in patients with advanced cancer. Nutritional deficits have a significant impact on mortality, morbidity and quality of life among those patients. Direct parameters (resistance, reactance, phase angle (PA)) determined by bioelectrical impedance analysis (BIA) may be used for monitoring of tissue electrical properties. These values may be used as prognostic markers in various disease conditions. Objective. The aim of the study was to examine tissue electrical properties in patients with cancers. Design. BIA was performed in a group of 13 patients with cancer before chemotherapy and 13 healthy volunteers (control group), whereas the ImpediMed bioimpedance analysis SFB7 BioImp v1.55 (Pinkenba Qld 4008, Australia), was applied. The Shapiro-Wilk (S-W) test was used to assess the distribution conformity of examined parameters with a normal distribution; the Fisher (F) test was used to assess variance homogeneity. To compare the two groups (independent samples) according to the type of distribution and variance homogeneity a Student’s T-Test was used. A p value < 0,005 was considered statistically significant. Results. In cancer patients PA was significantly (p=0.002) lower than in the control group (4.62o š 0,87 vs. 5.69o š 0.71, respectively). Resistance was significantly (p = 0.048) larger in patients with cancer than in the control group (573.06 š 63.78 ohm vs. 514.48 š 78.78 ohm, respectively). No significant differences of reactance were found between cancer patients and the control group (46.3 š 7.9 ohm vs. 50.62 š 5.43 ohm; p = 0.12). Conclusion. Patients with cancers have altered tissue electrical properties (resistance and phase angle).Niedożywienie wśród pacjentów z chorobą nowotworową stanowi istotny klinicznie problem, wpływając na zwiększoną śmiertelność, umieralność oraz jakość życia. Bezpośrednie pomiary bioimpedancji elektrycznej (opór indukcyjny, opór pojemnościowy, kąt fazowy) stanowić mogą prognostyczny marker stanu zdrowia. Celem badania było wykazanie różnic w wartościach oporu indukcyjnego, pojemnościowego i kąta fazowego pomiędzy pacjentami z chorobą nowotworową a zdrowymi ochotnikami. Materiał. Pomiar bioimpedancji elektrycznej wykonano w grupie 13 pacjentów z potwierdzoną chorobą nowotworową przed chemioterapią i w grupie kontrolnej złożonej z 13 zdrowych ochotników (ImpediMed bioimpedance analysis SFB7 BioImp v1.55; Pinkenba Qld 4008, Australia). Zastosowane metody. Wartości analizowanych parametrów scharakteryzowano za pomocą wartości średniej i odchylenia standardowego. Do oceny istnienia różnic parametrów mierzalnych między badanymi grupami zastosowano testy parametryczne, po uprzednim sprawdzeniu normalności rozkładu na podstawie testu W Shapiro-Wilka i jednorodności wariancji na podstawie testu F-Fischera. Do porównania dwóch grup niezależnych użyto testu t-Studenta. Przyjęto 5 proc. błąd wnioskowania i związany z nim poziom istotności p < 0,05, wskazujący na istnienie istotnych statystycznie różnic. Analizy statystyczne przeprowadzono w oparciu o oprogramowanie komputerowe STATISTICA v. 8.0 (StatSoft, Polska). Wyniki. Wykazano istotną statystycznie różnicę wartości kątów fazowych pomiędzy pacjentami z chorobą nowotworową a grupą zdrowych ochotników (4,62o š 0,87 vs. 5,69o š 0,71; p = 0,002) oraz w oporze indukcyjnym pomiędzy pacjentami z chorobą nowotworową a grupą zdrowych ochotników (573,06 š 63,78 ohm vs. 514,48 š 78,78 ohm; p = 0,048). Nie wykazano istotnej statystycznie różnicy w oporze pojemnościowym pomiędzy pacjentami z chorobą nowotworową a grupą zdrowych ochotników (46,3 š 7,9 ohm vs. 50,62 š 5,43 ohm; p = 0,12). Wnioski: Wykazano zmiany właściwości elektrycznych tkanki (opór indukcyjny i kąt fazowy) u pacjentów z chorobą nowotworową

Nichrome Capacitors on Polycarbonate Substrate for Monitoring Cell Culture Using Impedance Sensing Technique

The aim of this work was to present a method of tissue culture research by measuring the impedance of cells cultured in the presence of nichrome. For this purpose, the Electric Cell-substrate Impedance Sensing system was used with a prototype substrate containing comb capacitors made of nichrome. Magnetron sputtering, photolithography and etching processes were used to produce the thin-film electrodes. In the experimental part, cells of mouse fibroblast cell line L929 were cultured according to the instruction manual in complete medium, under controlled growth conditions. Inoculation of arrays was carried out by 300 microliters per well of cell suspension at ~1.2×105 cells/ml. The results of the monitoring cells behavior in tissue culture indicate good cell viability and proliferative potential

Effect of selenium supplementation in thyroid gland diseases

Selenium, a non-metal chemical element, is present in the human body in trace quantities and accumulates mostly in the thyroid gland. Selenium-rich food includes offal, meat and meat products, seafood, milk and dairy products, yeast, and bread. The aim of the study is to collate and discuss research results obtained over the last 13 years regarding the influence of selenium in diseases of the thyroid gland. Selenium deficiency can lead to a number of thyroid diseases. Over 30 proteins containing selenium called selenoproteins, and their numerous functions in the human body, have been identified. Research shows that selenium is essential for proper synthesis, activation and metabolism of thyroid hormones. It also can postpone the development of hypothyroidism, reduce the level of anti-thyroid peroxidase antibodies (TPOAb) and thyroglobulin antibodies (TgAb), normalize thyroid echogenicity in ultrasound examination, improve the condition of patients with Graves’ disease andautoimmune thyroiditis (AIT) (Hashimoto’s thyroiditis), and reduce the incidence of postpartum thyroid dysfunction. The recommended dose of selenium for adults is 45-55 μg 24 h-1 (Polish recommendations) or 55 μg 24 h-1 (recommendations in the US). Selenium may have a toxic effect in doses above 400 μg 24 h-1; therefore a threshold of 400 μg 24 h-1 has been adopted as the maximum safe dose. The role of selenium supplementation in diseases of the thyroid gland is still subject to discussion

Bioelectrical Impedance Phase Angle as a Prognostic Indicator of Survival in Head-and-Neck Cancer

Background: Phase angle could be an alternative to subjective global assessment for the assessment of nutrition status in patients with head-and-neck cancer. Methods: We prospectively evaluated a cohort of 75 stage IIIB and IV head-and-neck patients treated at the Otolaryngology Department, Head and Neck Surgery, Medical University of Lublin, Poland. Bioelectrical impedance analysis was performed in all patients using an analyzer that operated at 50 kHz. The phase angle was calculated as reactance divided by resistance (Xc/R) and expressed in degrees. The Kaplan–Meier method was used to calculate survival. Results: Median overall survival in the cohort was 32.0 months. At the time of analysis, 47 deaths had been recorded in the cohort (62.7%). The risk of shortened overall survival was significantly higher in patients whose phase angle was less than 4.733 degrees than in the remaining patients (19.6 months vs. 45 months, p = 0.0489; chi-square: 3.88; hazard ratio: 1.8856; 95% confidence interval: 1.0031 to 3.5446). Conclusions: Phase angle might be prognostic of survival in patients with advanced head-and-neck cancer. Further investigation in a larger population is required to confirm our results