Influence of cationic and anionic additives on the electrical properties of ionophore-based ion-selective membranes

The steady-state electrical behavior of cation-selective ionophore membranes with different kinds of ionic additives was studied on a theoretical basis. Membranes with both mobile and fixed anionic sites exhibit nonlinear current–voltage curves, which is in contrast with the ohmic behavior of pure fixed-site membranes. This can be explained from the specific concentration profiles in the membrane, illustrating pronounced polarization effects for the mobile sites. Surprisingly, the influence of the fixed sites on the current response is still observable even when the mobile sites predominate. At high voltages, current saturation occurs by limitations of the back-diffusion of free ionophores. This can be overcome when other, uncomplexed, cations contribute to the current flow. Membranes with both cationic and anionic sites cannot be strongly polarized, in analogy to other systems where an inert electrolyte is confined to a given phase. These membranes respond with current saturation at relatively low voltages. Currents above this limit can be achieved by an additional permeation of anions from the aqueous solution through the membrane, as shown by model calculations.     

Brainstem auditory evoked magnetic fields in response to stimulation with brief tone pulses

Brainstem auditory evoked magnetic fields evoked by monaural stimulation with Gaussian-modulated tone pulses were recorded in the parieto-occipital region of two normally hearing human subjects. Very small signals with an amplitude of 5-10 fT were detectable only under optimal (with respect to selection of subjects, technique of stimulation, minimization of ambient and instrumental noise level, signal processing, etc.) experimental conditions. The most important findings are that: (a) different components of the magnetic signal show maxima at different recording positions over the scalp, and (b) the magnetic equivalent of the electric wave V exhibits a polarity reversal at symmetrical positions in both hemispheres.     

The effect of surgery, performed under ischemia, on the fine structure of the hand muscles]

The ultrastructural picture of the intact and injured hand muscles has been examined by the authors during and after operations in tourniquet ischaemia of 12 patients, in connection with tendon and nerve reconstruction. Muscle specimina were taken partly in the beginning of the ischaemization, and partly at the end ot it, every 15--20 minutes, and the muscle specimina have been examined by means of electron microscope. It has been found that in the first 2 hours of ischaemia neither the intact muscles, nor those previously injured suffer demonstrable damage.     

Stevia und Steviaglykoside in der Ernährung von Kindern und Jugendlichen

In the position paper of the American Academy of Nutrition and Dietetics on non-nutritive sweeteners, stevia and steviol glycosides are listed as save products that can be used in a nutritional regimen recommendable for general use. According to current FAO/WHO data, the average nutritional intake of stevia glycoside is approximately 1–2 mg/kg body weight, thus not exceeding the recommended accepted daily intake (ADI) of 4 mg/kg body weight.The Nutrition Committee of the Austrian Academy of Paediatrics demands clear declarations of the amounts of stevia and steviol glycosides for all nutrients of relevance to children and adolescents (fruit juice, carbonated beverages, cow’s milk, etc.) in order to calculate the actual nutritional intake of stevia and steviol glycosides.     

DNA methylation and breast cancer-associated variants

Breast Cancer Research and Treatment - A breast cancer polygenic risk score (PRS) comprising 313 common variants reliably predicts disease risk. We examined possible relationships between genetic...     

Prognostic role of adjuvant radiotherapy in triple‐negative breast cancer: A historical cohort study

The value of adjuvant radiotherapy in triple‐negative breast cancer (TNBC) is currently debated. We assessed the association between adjuvant radiotherapy and survival in a large cohort of Asian women with TNBC. Women diagnosed with TNBC from 2006 to 2011 in five Asian centers (N = 1,138) were included. Survival between patients receiving mastectomy only, breast‐conserving therapy (BCT, lumpectomy and adjuvant radiotherapy) and mastectomy with radiotherapy were compared, and adjusted for demography, tumor characteristics and chemotherapy types. Median age at diagnosis was 53 years (range: 23–96 years). Median tumor size at diagnosis was 2.5 cm and most patients had lymph node‐negative disease. The majority of patients received adjuvant chemotherapy (n = 861, 76%) comprising predominantly anthracycline‐based regimes. In 775 women with T1‐2, N0‐1, M0 TNBCs, 5‐year relative survival ratio (RSR) was highest in patients undergoing mastectomy only (94.7%, 95% CI: 88.8–98.8%), followed by BCT (90.8%, 95% CI: 85.0–94.7%), and mastectomy with radiotherapy (82.3%, 95% CI: 73.4–88.1%). The adjusted risks of mortality between the three groups were not significantly different. In 363 patients with T3‐4, N2‐3, M0 TNBCs, BCT was associated with highest 5‐year RSR (94.1%, 95% CI: 81.3–99.4%), followed by mastectomy with radiotherapy (62.7%, 95% CI: 54.3–70.1%), and mastectomy only (58.6%, 95% CI: 43.5–71.6%). Following multivariable adjustment, BCT and mastectomy with radiotherapy remained significantly associated with lower mortality risk compared to mastectomy only. Overall, adjuvant radiotherapy was associated with higher survival in women aged <40 years, but not in older women. Adjuvant radiotherapy appears to be independently associated with a survival gain in locally advanced as well as in very young TNBC.     

Possible role of formaldehyde in the apoptotic and mitotic effect of 1-methyl-ascorbigen

PC-3 human prostate carcinoma cells were treated with 100 ug/ml 1-methyl-ascorbigen (Me-Asc). This treatment resulted in a significant decrease in tumor cell number in parallel with an increase in apoptotic cells. The formaldehyde (HCHO) level in the culture medium was also increased. Dimedone (Di), a known capture molecule forming formaldemethone with HCHO, applied simultaneously with Me-Asc in 10 ug/ml doses diminished the apoptosis-inducing effect of Me-Asc. The possible role of in situ generated HCHO in the induction of apoptosis is discussed.     

Role of mammogram and ultrasound imaging in predicting breast cancer subtypes in screening and symptomatic patients

BACKGROUNDBreast cancer (BC) radiogenomics, or correlation analysis of imaging features and BC molecular subtypes, can complement genetic analysis with less resource-intensive diagnostic methods to provide an early and accurate triage of BC. This is pertinent because BC is the most prevalent cancer amongst adult women, resulting in rising demands on public health resources. AIMTo find combinations of mammogram and ultrasound imaging features that predict BC molecular subtypes in a sample of screening and symptomatic patients. METHODSThis retrospective study evaluated 328 consecutive patients in 2017-2018 with histologically confirmed BC, of which 237 (72%) presented with symptoms and 91 (28%) were detected via a screening program. All the patients underwent mammography and ultrasound imaging prior to biopsy. The images were retrospectively read by two breast-imaging radiologists with 5-10 years of experience with no knowledge of the histology results to ensure statistical independence. To test the hypothesis that imaging features are correlated with tumor subtypes, univariate binomial and multinomial logistic regression models were performed. Our study also used the multivariate logistic regression (with and without interaction terms) to identify combinations of mammogram and ultrasound (US) imaging characteristics predictive of molecular subtypes.RESULTSThe presence of circumscribed margins, posterior enhancement, and large size is correlated with triple-negative BC (TNBC), while high-risk microcalcifications and microlobulated margins is predictive of HER2-enriched cancers. Ductal carcinoma in situ is characterized by small size on ultrasound, absence of posterior acoustic features, and architectural distortion on mammogram, while luminal subtypes tend to be small, with spiculated margins and posterior acoustic shadowing (Luminal A type). These results are broadly consistent with findings from prior studies. In addition, we also find that US size signals a higher odds ratio for TNBC if presented during screening. As TNBC tends to display sonographic features such as circumscribed margins and posterior enhancement, resulting in visual similarity with benign common lesions, at the screening stage, size may be a useful factor in deciding whether to recommend a biopsy.CONCLUSIONSeveral imaging features were shown to be independent variables predicting molecular subtypes of BC. Knowledge of such correlations could help clinicians stratify BC patients, possibly enabling earlier treatment or aiding in therapeutic decisions in countries where receptor testing is not readily available.