141 research outputs found
Electro-acoustic transducers on the basis of thin PZT-films
In the present work PZT-type thin films have been obtained by RF sputtering and electroacoustic transducers characterized by high sensitivity (t), wide range of measured relative deformations (q) and high working frequencies (w) were built. Polycrystalline ferroelectric thin films with the perovskite type structure and chemical composition Pb(Zro.33Tio.4sWo.oiCdo.oi)03 have been fabricated by RF sputtering. The films exhibited
slightly lower values of dielectric constant, residual polarization and piezoelectric coefficient </33 = 80 x 10“12 C/N, as compared with the ceramics of the same chemical composition. The thin films keep such a value of du up to the Curie point. On the basis of the PZT-type thin films the isotropic and anisotropic piezoelectric sensors were built and investigated. The electrical signal of the isotropic sensors is proportional to the sum of the
main components of the relative deformation tensor whereas the signal of the anisotropic sensors depends on the angle between the sensor axis and the main axis of the deformation tensor of the sample under investigation. The sensors are characterized by high stability of the generated signal
Multivariate analysis of oestrogen receptor alpha, pS2, metallothionein and CD24 expression in invasive breast cancers
Determination of oestrogen receptor alpha (ER) represents at present the most important predictive factor in breast cancers. Data of ours and of other authors suggest that promising predictive/prognostic factors may also include pS2, metallothionein (MT) and CD24. Present study aimed at determining prognostic and predictive value of immunohistochemical determination of ER, pS2, MT, and CD24 expression in sections originating from 104 patients with breast cancer. An univariate and multivariate analysis was performed. Both univariate and multivariate analyses demonstrated that cytoplasmic-membranous expression of CD24 (CD24c-m) represents a strong unfavourable prognostic factor in the entire group and in most of the subgroups of patients. In several subgroups of the patients also a prognostic value was demonstrated of elevated expression of pS2 and of membranous expression of CD24. Our studies demonstrated that all patients with good prognostic factors (higher ER and pS2 expressions, lower MT expression, CD24c-m negativity) survived total period of observation (103 months). The study documented that cytoplasmic-membranous expression of CD24 represented an extremely strong unfavourable prognostic factor in breast cancer. Examination of the entire panel of the studied proteins permitted to select a group of patients of an exceptionally good prognosis
Differences in oestrogen and progesterone receptors, HER-2, p53 expression and proliferation in ductal breast cancers in relation to histopathological grade
In case of breast cancer the grade of differentiation and expression of oestrogen
and progesterone receptors falls within the first category of prognostic factors
according to the College of American Pathologists. HER-2, p53 and Ki67 belong
to the second category and their significance still awaits confirmation. The aim of
the present study was to examine the relationship between the intensity of expression
of oestrogen receptors (ER), progesterone receptors (PgR), HER-2, p53
and Ki67 in cells of ductal breast cancer of G1, G2 or G3 differentiation grade. In
paraffin sections of 60 ductal breast cancers (20 cases in G1, 20 in G2 and 20 in
G3), immunocytochemical reactions were performed to detect the expression of
ER, PgR, HER-2, p53 and Ki67. Following a semi-quantitative appraisal of the
preparations under examination, appropriate statistical tests were used to document
significant relationships. We noted significant positive correlations between
ER and PgR (the entire group studied, G1–3, and the G1 group), HER-2 and p53
(G2) and between p53 and Ki67 expression (G2). Significant negative correlations
were found between ER and p53 (G1–3), PgR and p53 (G1–3, G1, G3) and between
PgR and Ki67 (G1–3, G2). The studies performed demonstrated distinct
relationships between the expression intensity of various proteins in tumour cells
in relation to the grade of differentiation of the tumour. We also showed that
a parallel determination of ER, PgR and p53 expression may carry high predictive
value as to response to tamoxifen treatment
The influence of Pb vacancies on the properties of PZT-type ceramics transducers
This article is dedicated to prof. J. Ranachowski The result of investigations of the influence of lead vacancies on the crystalline structure of PZT-type ceramic piezoelectric materials is presented. The solid solution of PbTiO3 - PbZrO3 - sigma n=13 Pb(B'1-alpha B''alpha)O3, characterized by the perovskite-type structure (ABO3), is the basis of those materials. The lead vacancies (VPb) was originated by a thermal treatment. Investigations of the influence of the lead deficiency on the crystalline structure of PZT-type ceramics have been performed for solid solutions characterized by compositions corresponding to the tetragonal or rhombohedral boundary of the morphotropic region (PCR-1, PCR-8: Piezoelectric Ceramics of Rostov) and to tetragonal phase region compositions (ceramics of Pb1-x(Zr0.39Ti0.59W0.01Cd0.01) O3). It has been found that the deficiency in lead causes a reconstruction of the perovskite phase crystalline structure or a change of the elementary cell parameters of that phase. The solid solutions on the basis of Pb(Zr,Ti)O3 resolve themselves into PbTiO3, ZrO2 and PbO when the lead deficiency caused by thermal treatment increases
Loss of estrogen receptor beta expression correlates with shorter overall survival and lack of clinical response to chemotherapy in ovarian cancer patients
Background: Estrogen receptor beta (ERβ) belongs to a large family of nuclear receptors. Recent studies have suggested that ERβ in contrast to ERα might act as a tumour suppressor in ovarian cancer (OVCA). Materials and Methods: Expression of ERβ was detected by immunocytochemistry in 11 OVCA cell lines and by immunohistochemistry in 43 (41 FIGO stage III) OVCA specimens prepared before chemotherapy and 30 specimens from the same group after chemotherapy. Cisplatin sensitivity in the 11 cell lines was also analysed. Results: No significant correlations between cisplatin-sensitivity and expression of ERβ was found in the cell lines. In the cases which responded well to chemotherapy (complete response) ERβ expression at preliminary laparotomy (PL) was significantly higher (p=0.0004) than in those with progressive disease. Kaplan-Meier analysis revealed that the patients with higher ERβ expression (>30% of cells) at PL had an increased overall survival time and progression-free time (p=0.00161 and p=0.03255, respectively) than the patients with lower ERβ espression. Significantly shorter overall survival time characterized the cases with lower immunoreactivity score of ERβ expression at secondary cytoreduction (SCR) (p=0.00346). Conclusion: The loss of ERβ expression in ovarian tumours may be a feature of malignant transformation
Stromal myofibroblasts in breast cancer: relations between their occurrence, tumor grade and expression of some tumour markers
It is suggested that tumour stromal myofibroblasts exert an
unfavourable effect on the biology of breast cancer. We are
aware of only a single study which examined relationships
between manifestation of myofibroblasts in the stroma of breast
cancer and clinicopathological data of the patients. The present
study was aimed at estimation of the effect exerted by
myofibroblasts present in the tumour stroma on principal
pathological parameters and on expression of Ki67, P53 and HER-2
proteins in the group of the most frequent breast cancers, the
ductal cancers. In paraffin sections of 60 ductal breast cancers
(20 cases in G1, 20 in G2 and 20 in G3), immunohistochemical
reactions were performed to detect expression of smooth muscle
actin (SMA) in order to visualize myofibroblasts, Ki67, P53 and
HER-2. The studies demonstrated that the most numerous
myofibroblasts were present in G3 cases and they were the least
frequent in G1 cases (P = 0.02). Positive correlations were
observed between the presence of myofibroblasts in tumour stroma
and expression of Ki67 and HER-2 in breast cancer cells in the
entire group (P < 0.001 and P = 0.001, respectively), in G2
cases (P = 0.003 and P = 0.03) and in G3 cases (P = 0.01 and P =
0.03). Considering that the higher grade, Ki67 and HER-2 are
thought to represent unfavourable prognostic factors, the
elevated content of myofibroblasts in tumour stroma is probably
typical for cases with worse prognosis
Estrogen Receptor Alpha Expression in Ovarian Cancer Predicts Longer Overall Survival
Estrogen as a potential factor of ovarian carcinogenesis, acts via two nuclear receptors, estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ), but the cellular signal pathways involved are not completely clear so far. In this study we have described the expression of ERα, detected by immunocytochemistry in 11 ovarian carcinoma cell lines and by immunohistochemistry in 43 Federation Internationale des Gyneacologistes et Obstetristes stage III ovarian carcinoma specimens prepared before and after treatment with cisplatin-based schemes. For cisplatin resistance is a major obstacle in the treatment of ovarian carcinoma, analysis of cisplatin sensitivity in 11 ovarian carcinoma cell line was also performed. The strong nuclear ERα expression was only shown in the single A2780P cell line. Expression of ERα in tissue specimens did not reveal any correlations between histopathological parameters (histologic type and grading). We demonstrated a significant association with ERα expression in specimens from primary laparotomies (PL) and cause–specific survival. In the cases terminated by death of the patient, overall immunoreactivity score of ERα expression at PL was significantly lower than in surviving patients. In addition, Kaplan-Meier analysis revealed significantly shorter overall survival time and progression-free time in cases with lower immunoreactivity score of ERα expression at PL. Our findings support the hypothesis that aberrant hormone activity, by way of altered receptor expression, might be an important factor in the malignant transformation of ovarian cancer
Inhibition of APN/CD13 leads to suppressed progressive potential in ovarian carcinoma cells
<p>Abstract</p> <p>Background</p> <p>Aminopeptidase N (APN/CD13), a 150-kDa metalloprotease, is a multifunctional cell surface aminopeptidase with ubiquitous expression. Recent studies have suggested that APN/CD13 plays an important role in tumor progression of several human malignancies. In the current study, we investigated the role of APN/CD13 in ovarian carcinoma (OVCA) progression.</p> <p>Methods</p> <p>We first examined the expression of APN/CD13 at the protein level in a variety of OVCA cell lines and tissues. We subsequently investigated whether there was a correlation between APN/CD13 expression and invasive potential of various OVCA cell lines. Moreover, we investigated the function of APN/CD13 in OVCA cells using bestatin, an APN/CD13 inhibitor, or transfection of siRNA for APN/CD13.</p> <p>Results</p> <p>We confirmed that APN/CD13 was expressed in OVCA tissues and cell lines to various extents. There was a positive correlation between APN/CD13 expression and migratory potential in various OVCA cell lines with accordingly enhanced secretion of endogenous MMP-2. Subsequently, we found a significant decrease in the proliferative and migratory abilities of OVCA cells after the addition of bestatin or the inhibition of APN/CD13 expression by siRNA. Furthermore, in an animal model, daily intraperitoneal administration of bestatin after inoculation of OVCA cells resulted in a decrease of peritoneal dissemination and in prolonged survival of nude mice.</p> <p>Conclusion</p> <p>The current data indicate the possible involvement of APN/CD13 in the development of OVCA, and suggest that clinical use of bestatin may contribute to better prognosis for ovarian carcinoma patients.</p
- …