The Significance of Cell Surface N-Glycosylation for Internalization and Potency of Cytotoxic Conjugates Targeting Receptor Tyrosine Kinases

Precise anticancer therapies employing cytotoxic conjugates constitute a side-effect-limited, highly attractive alternative to commonly used cancer treatment modalities, such as conventional chemotherapy, radiotherapy or surgical interventions. Receptor tyrosine kinases are a large family of N-glycoproteins intensively studied as molecular targets for cytotoxic conjugates in various cancers. At the cell surface, these receptors are embedded in a dense carbohydrate layer formed by numerous plasma membrane glycoproteins. The complexity of the cell surface architecture is further increased by galectins, secreted lectins capable of recognizing and clustering glycoconjugates, affecting their motility and activity. Cell surface N-glycosylation is intensively remodeled by cancer cells; however, the contribution of this phenomenon to the efficiency of treatment with cytotoxic conjugates is largely unknown. Here, we evaluated the significance of N-glycosylation for the internalization and toxicity of conjugates targeting two model receptor tyrosine kinases strongly implicated in cancer: HER2 and FGFR1. We employed three conjugates of distinct molecular architecture and specificity: Affibody_HER2-vcMMAE (targeting HER2), vcMMAE-KCK-FGF1.E and T-Fc-vcMMAE (recognizing different epitopes within FGFR1). We demonstrated that inhibition of N-glycosylation reduced the cellular uptake of all conjugates tested and provided evidence for a role of the galectin network in conjugate internalization. In vitro binding studies revealed that the reduced uptake of conjugates is not due to impaired HER2 and FGFR1 binding. Importantly, we demonstrated that alteration of N-glycosylation can affect the cytotoxic potential of conjugates. Our data implicate a key role for cell surface N-glycosylation in the delivery of cytotoxic conjugates into cancer cells.     

Selected Mediators of Inflammation in Patients with Acute Ischemic Stroke

During a stroke, a series of biochemical and metabolic changes occur which eventually lead to the death of cells by necrosis or apoptosis. This is a multi-stage process involving oxidative stress and an inflammatory response from the first signs of occlusion of a blood vessel until the late stages of regeneration and healing of ischemic tissues. The purpose of the research was to assess the concentration of pro-inflammatory cytokines IL-6 and TNF-α in the blood serum of patients with ischemic stroke (AIS) and to investigate their role as new markers in predicting functional prognosis after thrombolytic therapy. The researches have shown that the concentrations of the measured biomarkers were higher compared to the control group. Serum levels of IL-6 and THF-α before the initiation of intravenous thrombolysis were lower in the subgroup of patients with a favourable functional result (mRS: 0–2 pts) compared to the group of patients with an unfavourable functional result (mRS: 3–6 pts). A positive correlation was found between the concentration of IL-6 and TNF-α in patients with AIS during <4.5 h and on one day after the onset of stroke, which means that the concentration of IL-6 increases with the increase in TNF-α concentration. It has also been shown that higher levels of IL-6 in the acute phase of stroke and on the first and seventh days, and TNF-α during onset, were associated with poorer early and late prognosis in patients treated with intravenous thrombolysis. A relationship was found between the level of IL-6 and TNF-α in the subacute AIS and the severity of the neurological deficit. It has been shown that the investigated biomarkers may be a prognostic factor in the treatment of thrombolytic AIS.     

ESR-spectroscopy in medical practice and biomedical research

The authors describe the use of the ESR technique during the past 20 years. There are many examples of the application of the technique in different investigations. The authors propose the new way of training medical students to apply it.     

Sulfonated polysulfone membranes with antifouling activity

The protein fouling phenomenon was investigated on modified polysulfone ultrafiltration membranes. The sulfonation degree was correlated to the extent of deposition of bovine serum albumin. It was shown that membranes prepared from modified polysulfone were less fouled than their off-charge analogues. The fouling phenomenon was also investigated for membranes prepared from co-cast blends. It was demonstrated that blends containing more than 50 wt.-% of sulfonated derivative behaved like a membrane from pure sulfonated polysulfone. The effect was attributed to surface separation of polymers and formation of surfaces enriched with sulfonic groups.     

Adrenal glands in anencephaly

An apparatus for collection of free-flow urine from female horses is described. This apparatus is a modification of a similar device described previously. It allows the collection of voided urine from adult female horses without confining them to metabolic stables or resorting to invasive procedures like bladder catheterisation. It is relatively easy to use after a short adaptation period.     

Classifier ensemble for an effective cytological image analysis

Breast cancer is the most common type of cancer among women. As early detection is crucial for the patient’s health, much attention has been paid to the development of tools for effective recognition of this disease. This article presents an application of image analysis and classification methods for fine needle biopsy. In our approach, each patient is described by nine microscopic images taken from the biopsy sample. The images are related to regions of the biopsy that seem interesting to the physician who selects them arbitrarily. We propose four different hybrid segmentation algorithms dedicated to processing these images and examine their effectiveness for the nuclei feature extraction task. Classification is carried out with the usage of a classifier ensemble based on the Random Subspaces approach. To boost its effectiveness, we use a linear combination of the support functions returned by the individual classifiers in the ensemble. In the proposed medical support system, the final decision about the patient is delivered after a fusion of nine separate outputs of the classifier – each for a different image. Experimental results carried out on a diverse dataset collected by the authors prove that the proposed solution outperforms state-of-the-art classifiers and shows itself to be a valuable tool for supporting day-to-day cytologist’s routine.     

The influence of different factors on the kinetics of potentiostatic forming of pasted positive lead electrodes

The influence of such factors are the surface active material, H₃BO₃ and mixing of H₂SO₄ on the potentiostatic forming of positive lead electrodes with the production paste was investigated. The potentiostatic forming of pasted positive plates with 4PbO.PbSO₄ has been examined.     

An investigation of mass transfer in a countercurrent three-phase fluidized bed

The rate of absorption with chemical reaction has been measured in a bed of solid spheres fluidized by upward flowing gas and irrigated by downward flowing liquid for different reactant concentrations in the liquid phase and different values of the liquid superficial velocity.Values of the effective inerfacial area per unit volume of a static bed, a, and the gas-film mass-transfer coefficient, k_g, are reported as functions of the liquid superficial velocity.     

Non-BCS Temperature Dependence of Energy Gap in Thin Film Electron-Doped Cuprates

We investigate the dependence of the energy gap (G) on the temperature (T) for the electron-doped high-temperature superconductors. The following compounds, in the form of the thin films, have been taken into consideration: La_2?x Ce _x CuO₄ (LCCO), Pr_2?x Ce _x CuO₄ (PCCO), and Nd_2?x Ce _x CuO₄ (NCCO). It was found that G(T) deviates from the BCS prediction more, if a concentration of cerium assumes the lower values. For the lowest concentration (in the case of LCCO and NCCO), the function G(T) is not quite like the BCS curve, which is connected with the existence of the residual Nernst region. Next, it has been pointed out that the NCCO superconductor becomes structurally unstable for the maximum concentration of cerium, which is leading to the anomalous dependence of the energy gap on the temperature and the induction of the wide Nernst region.     

The deterministic subspace method for constructing classifier ensembles

Ensemble classification remains one of the most popular techniques in contemporary machine learning, being characterized by both high efficiency and stability. An ideal ensemble comprises mutually complementary individual classifiers which are characterized by the high diversity and accuracy. This may be achieved, e.g., by training individual classification models on feature subspaces. Random Subspace is the most well-known method based on this principle. Its main limitation lies in stochastic nature, as it cannot be considered as a stable and a suitable classifier for real-life applications. In this paper, we propose an alternative approach, Deterministic Subspace method, capable of creating subspaces in guided and repetitive manner. Thus, our method will always converge to the same final ensemble for a given dataset. We describe general algorithm and three dedicated measures used in the feature selection process. Finally, we present the results of the experimental study, which prove the usefulness of the proposed method.