Electron Transfer in a Bio-Photoelectrode Based on Photosystem I Multilayer Immobilized on the Conducting Glass

A film of ~40 layers of partially oriented photosystem I (PSI) complexes isolated from the red alga Cyanidioschyzon merolae formed on the conducting glass through electrodeposition was investigated by time-resolved absorption spectroscopy and chronoamperometry. The experiments were performed at a range of electric potentials applied to the film and at different compositions of electrolyte solution being in contact with the film. The amount of immobilized proteins supporting light-induced charge separation (active PSI) ranged from ~10%, in the absence of any reducing agents (redox compounds or low potential), to ~20% when ascorbate and 2,6-dichlorophenolindophenol were added, and to ~35% when the high negative potential was additionally applied. The origin of the large fraction of permanently inactive PSI (65–90%) was unclear. Both reducing agents increased the subpopulation of active PSI complexes, with the neutral P700 primary electron donor, by reducing significant fractions of the photo-oxidized P700 species. The efficiencies of light-induced charge separation in the PSI film (10–35%) did not translate into an equally effective generation of photocurrent, whose internal quantum efficiency reached the maximal value of 0.47% at the lowest potentials. This mismatch indicates that the vast majority of the charge-separated states in multilayered PSI complexes underwent charge recombination.     

Use of FIB to Study ZDDP Tribofilms

Focussed ion beam milling (FIB) followed by TEM has been used to study ZDDP tribofilms on rubbed steel surfaces. It has been found that the impact of high energy platinum and gallium ions during FIB causes significant morphological and structural changes to the uppermost 30–50 nm of a ZDDP tribofilm. This can be prevented by the low energy deposition of a quite thick gold layer prior to installation of the sample in the FIB facility. This problem, and its solution, have been quite widely reported in the non-tribology literature but have not previously been highlighted in the application of FIB to study tribological surfaces. It has also been found, using this gold pre-deposition method, that the bulk of the ZDDP tribofilm studied has a polycrystalline structure.     

The Importance of Platelets Response during Antiplatelet Treatment after Ischemic Stroke—Between Benefit and Risk: A Systematic Review

Ischemic stroke is a disease related to abnormal blood flow that leads to brain dysfunction. The early and late phases of the disease are distinguished. A distinction is made between the early and late stages of the disease, and the best effect in treating an ischemic stroke is usually achieved within the first hours after the onset of symptoms. This review looked at studies platelet activity monitoring studies to determine the risks and benefits of various approaches including antiplatelet therapy. A study was conducted on recently published literature based on PRISMA. This review includes 32 research articles directly addressing the importance of monitoring platelet function during antiplatelet therapy (dual or monotherapy) after ischemic stroke. In patients with transient ischemic attack or ischemic stroke, antiplatelet therapy can reduce the risk of stroke by 11–15%, assuming that patients respond well. Secondary prevention results are dependent on platelet reactivity, meaning that patients do not respond equally to antiplatelet therapy. It is very important that aspirin-resistant patients can benefit from the use of dual antiplatelet therapy. The individualized approach to secondary stroke prevention is to administer the most appropriate drug at the correct dose and apply the optimal therapeutic procedure to the individual patient.     

Bifunctional Opioid/Melanocortin Peptidomimetics for Use in Neuropathic Pain: Variation in the Type and Length of the Linker Connecting the Two Pharmacophores

Based on the mechanism of neuropathic pain induction, a new type of bifunctional hybrid peptidomimetics was obtained for potential use in this type of pain. Hybrids consist of two types of pharmacophores that are connected by different types of linkers. The first pharmacophore is an opioid agonist, and the second pharmacophore is an antagonist of the pronociceptive system, i.e., an antagonist of the melanocortin-4 receptor. The results of tests in acute and neuropathic pain models of the obtained compounds have shown that the type of linker used to connect pharmacophores had an effect on antinociceptive activity. Peptidomimetics containing longer flexible linkers were very effective at low doses in the neuropathic pain model. To elucidate the effect of linker lengths, two hybrids showing very high activity and two hybrids with lower activity were further tested for affinity for opioid (mu, delta) and melanocortin-4 receptors. Their complexes with the target receptors were also studied by molecular modelling. Our results do not show a simple relationship between linker length and affinity for particular receptor types but suggest that activity in neuropathic pain is related to a proper balance of receptor affinity rather than maximum binding to any or all of the target receptors.     

Investigating the Potential Use of Chemical Biopsy Devices to Characterize Brain Tumor Lipidomes

The development of a fast and accurate intraoperative method that enables the differentiation and stratification of cancerous lesions is still a challenging problem in laboratory medicine. Therefore, it is important to find and optimize a simple and effective analytical method of enabling the selection of distinctive metabolites. This study aims to assess the usefulness of solid-phase microextraction (SPME) probes as a sampling method for the lipidomic analysis of brain tumors. To this end, SPME was applied to sample brain tumors immediately after excision, followed by lipidomic analysis via liquid chromatography-high resolution mass spectrometry (LC-HRMS). The results showed that long fibers were a good option for extracting analytes from an entire lesion to obtain an average lipidomic profile. Moreover, significant differences between tumors of different histological origin were observed. In-depth investigation of the glioma samples revealed that malignancy grade and isocitrate dehydrogenase (IDH) mutation status impact the lipidomic composition of the tumor, whereas 1p/19q co-deletion did not appear to alter the lipid profile. This first on-site lipidomic analysis of intact tumors proved that chemical biopsy with SPME is a promising tool for the simple and fast extraction of lipid markers in neurooncology.     

Overcoming Steroid Resistance in Pediatric Acute Lymphoblastic Leukemia—The State-of-the-Art Knowledge and Future Prospects

Acute lymphoblastic leukemia (ALL) is the most common malignancy among children. Despite the enormous progress in ALL therapy, resulting in achieving a 5-year survival rate of up to 90%, the ambitious goal of reaching a 100% survival rate is still being pursued. A typical ALL treatment includes three phases: remission induction and consolidation and maintenance, preceded by a prednisone prephase. Poor prednisone response (PPR) is defined as the presence of ≥1.0 × 10⁹ blasts/L in the peripheral blood on day eight of therapy and results in significantly frequent relapses and worse outcomes. Hence, identifying risk factors of steroid resistance and finding methods of overcoming that resistance may significantly improve patients’ outcomes. A mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK-ERK) pathway seems to be a particularly attractive target, as its activation leads to steroid resistance via a phosphorylating Bcl-2-interacting mediator of cell death (BIM), which is crucial in the steroid-induced cell death. Several mutations causing activation of MAPK-ERK were discovered, notably the interleukin-7 receptor (IL-7R) pathway mutations in T-cell ALL and rat sarcoma virus (Ras) pathway mutations in precursor B-cell ALL. MAPK-ERK pathway inhibitors were demonstrated to enhance the results of dexamethasone therapy in preclinical ALL studies. This report summarizes steroids’ mechanism of action, resistance to treatment, and prospects of steroids therapy in pediatric ALL.     

Photocatalytic Degradation of 4,4′-Isopropylidenebis(2,6-dibromophenol) on Magnetite Catalysts vs. Ozonolysis Method: Process Efficiency and Toxicity Assessment of Disinfection By-Products

Flame retardants have attracted growing environmental concern. Recently, an increasing number of studies have been conducted worldwide to investigate flame-retardant sources, environmental distribution, living organisms’ exposure, and toxicity. The presented studies include the degradation of 4,4′-isopropylidenebis(2,6-dibromophenol) (TBBPA) by ozonolysis and photocatalysis. In the photocatalytic process, nano- and micro-magnetite (n-Fe₃O₄ and μ-Fe₃O₄) are used as a catalyst. Monitoring of TBBPA decay in the photocatalysis and ozonolysis showed photocatalysis to be more effective. Significant removal of TBBPA was achieved within 10 min in photocatalysis (ca. 90%), while for ozonation, a comparable effect was observed within 70 min. To determine the best method of TBBPA degradation concentration on COD and TOC, the removals were examined. The highest oxidation state was obtained for photocatalysis on μ-Fe₃O₄, whereas for n-Fe₃O₄ and ozonolysis, the COD/TOC ratio was lower. Acute toxicity results show noticeable differences in the toxicity of TBBPA and its degradation products to Artemia franciscana and Thamnocephalus platyurus. The EC₅₀ values indicate that TBBPA degradation products were toxic to harmful, whereas the TBPPA and post-reaction mixtures were toxic to the invertebrate species tested. The best efficiency in the removal and degradation of TBBPA was in the photocatalysis process on μ-Fe₃O₄ (reaction system 1). The examined crustaceans can be used as a sensitive test for acute toxicity evaluation.     

Effects of SARS-CoV-2 Inflammation on Selected Organ Systems of the Human Body

Introduction and purpose of the study: SARS-CoV-2 virus does not only affect the respiratory system. It may cause damage to many organ systems with long-term effects. The latest scientific reports inform that this virus leaves a long-term trace in the nervous, circulatory, respiratory, urinary and reproductive systems. It manifests itself in disturbances in the functioning of the organs of these systems, causing serious health problems. The aim of the study was to review the latest research into the long-term effects of COVID-19 and determine how common these symptoms are and who is most at risk. Based on a literature review using the electronic scientific databases of PubMed and Web of Science on the long-term effects of SARS-CoV-2 infection, 88 studies were included in the analysis. The information contained in the analyzed literature shows that the SARS-CoV-2 virus can cause multi-organ damage, causing a number of long-term negative health complications. Conclusions: There is evidence that the virus can cause long-term complications lasting more than six months. They mainly concern disturbances in the functioning of the nervous, circulatory and respiratory systems. However, these studies are small or short-lasting, and many are speculative.     

Myo-inositol hexakisphosphate degradation by Bifidobacterium infantis ATCC 15697

The ability of five strains of different bifidobacterial species (Bifidobacterium animalis, B. bifidum, B. infantis, B. longum, B. pseudolongum) isolated from human and animal gut to degrade myo-inositol hexaphosphate or phytic acid (InsP(6)) has been evaluated. The disappearance of phytate and the generation of lower myo-inositol phosphates were determined in a complex medium in which phytic acid was the only source of phosphorus. Bifidobacterium infantis ATCC 15697 showed the highest level of phytate-degrading activity. This strain displayed optimal activity at slight acid pH (6.0-6.5) and 50 degrees C, but also retained high activity levels at neutral pH and 37 degrees C. B. infantis ATCC 15697 produced maximum activity during the stationary phase of growth and when 1% lactose was used as carbon source. In contrast, the presence of inorganic phosphate in the growth medium inhibited phytase activity. The ability of B. infantis ATCC 15697 to generate lower myo-inositol phosphates and, particularly, accumulate myo-inositol tri-phosphates (InsP(3)) from partial hydrolysis of InsP(6) could contribute to the reduction of the anti-nutritional properties of InsP(6) and the generation of intermediate compounds with beneficial properties during food processing and gastrointestinal transit.     

The Influence of Betulin and Its Derivatives EB5 and ECH147 on the Antioxidant Status of Human Renal Proximal Tubule Epithelial Cells

Betulin and its derivatives, 28-propyne derivative EB5 and 29-diethyl phosphonate analog ECH147, are promising compounds in anti-tumor activity studies. However, their effect on kidney cells has not yet been studied. The study aimed to determine whether betulin and its derivatives—EB5 and ECH147—influence the viability and oxidative status of human renal proximal tubule epithelial cells (RPTECs). The total antioxidant capacity of cells (TEAC), lipid peroxidation product malondialdehyde (MDA) level, and activity of antioxidant enzymes (SOD, CAT, and GPX) were evaluated. Additionally, the mRNA level of genes encoding antioxidant enzymes was assessed. Cisplatin and 5-fluorouracil were used as reference substances. Betulin and its derivatives affected the viability and antioxidant systems of RPTECs. Betulin strongly reduced TEAC in a concentration-dependent manner. All tested compounds caused an increase in MDA levels. The activity of SOD, CAT, and GPX, and the mRNA profiles of genes encoding antioxidant enzymes depended on the tested compound and its concentration. Betulin showed an cisplatin-like effect, indicating its nephrotoxic potential. Betulin derivatives EB5 and ECH147 showed different impacts on the antioxidant system, which gives hope that these compounds will not cause severe consequences for the kidneys in vivo.