Topotecan Treatment and Its Toxic Effects on Hematologic Parameters and Trace Elements

The aim of this study was to investigate the effects of topotecan, a topoisomerase I-inhibiting anticancer agent, on hematologic parameters and serum levels of trace elements. The study was conducted on three groups consisting of 16 and 18 rabbits in the study groups and 15 rabbits in the control group. Rabbits in group I (n = 16) received high-dose topotecan intravenously (i.v.; 0.5 mg/kg once daily), while rabbits in group II (n = 18) received low-dose topotecan i.v. (0.25 mg/kg once daily) for 3 days. The 15 rabbits comprising the control group did not receive topotecan. Serum samples were collected from each rabbit on the first day, before the treatment, and on the 15th day of treatment. Erithrocytes, hemoglobin, white blood cell count, thrombocyte count, and trace elements such as selenium, copper, lead, zinc, and cobalt were analyzed. Hemoglobin levels and erythrocyte counts were lower in both study groups than in the control group. However, thrombocyte and leukocyte counts were similar in all three groups (p > 0.005). Serum trace element levels (copper, lead, zinc, and cobalt) did not differ significantly between groups. However, serum selenium levels were significantly lower in both study groups than the control group (p < 0.001). The results revealed that topotecan treatment causes a decrease in erythrocyte counts and hemoglobin levels due to bone marrow suppression, and these effects must be taken into account during treatment. In addition, selenium supplementation might be helpful in cancer patients receiving topotecan to increase the effect of the chemotherapeutic agent.     

Antifungal, phytotoxic and insecticidal properties of essential oil isolated from Turkish Origanum acutidens and its three components, carvacrol, thymol and p-cymene

The chemical composition of essential oil isolated by hydrodistillation from the aerial parts of Origanum acutidens was analyzed by GC-MS. Carvacrol (87.0%), p-cymene (2.0%), linalool acetate (1.7%), borneol (1.6%) and beta-caryophyllene (1.3%) were found to be as main constituents. Antifungal, phytotoxic and insecticidal activities of the oil and its aromatic monoterpene constituents, carvacrol, p-cymene and thymol were also determined. The antifungal assays showed that O. acutidens oil, carvacrol and thymol completely inhibited mycelial growth of 17 phytopathogenic fungi and their antifungal effects were higher than commercial fungicide, benomyl. However, p-cymene possessed lower antifungal activity. The oil, carvacrol and thymol completely inhibited the seed germination and seedling growth of Amaranthus retroflexus, Chenopodium album and Rumex crispus and also showed a potent phytotoxic effect against these plants. However, p-cymene did not show any phytotoxic effect. Furthermore, O. acutidens oil showed 68.3% and 36.7% mortality against Sitophilus granarius and Tribolium confusum adults, respectively. The findings of the present study suggest that antifungal and herbicidal properties of the oil can be attributed to its major component, carvacrol, and these agents have a potential to be used as fungicide, herbicide as well as insecticide.     

Distinctive communication networks in inactive states of β2-adrenergic receptor: Mutual information and entropy transfer analysis

Mutual information and entropy transfer analysis employed on two inactive states of human beta-2 adrenergic receptor (β₂-AR) unraveled distinct communication pathways. Previously, a so-called “highly” inactive state of the receptor was observed during 1.5 microsecond long molecular dynamics simulation where the largest intracellular loop (ICL3) was swiftly packed onto the G-protein binding cavity, becoming entirely inaccessible. Mutual information quantifying the degree of correspondence between backbone-C_α fluctuations was mostly shared between intra- and extra-cellular loop regions in the original inactive state, but shifted to entirely different regions in this latest inactive state. Interestingly, the largest amount of mutual information was always shared among the mobile regions. Irrespective of the conformational state, polar residues always contributed more to mutual information than hydrophobic residues, and also the number of polar-polar residue pairs shared the highest degree of mutual information compared to those incorporating hydrophobic residues. Entropy transfer, quantifying the correspondence between backbone-C_α fluctuations at different timesteps, revealed a distinctive pathway directed from the extracellular site toward intracellular portions in this recently exposed inactive state for which the direction of information flow was the reverse of that observed in the original inactive state where the mobile ICL3 and its intracellular surroundings drove the future fluctuations of extracellular regions.     

Absolute dose verification of static intensity modulated radiation therapy (IMRT) with ion chambers of various volumes and TLD detectors

Aim

This study aims at examining absolute dose verification of step-and-shoot intensity modulated radiation treatment (IMRT) of prostate and brain patients by use of ion chambers of two different volumes and thermoluminescent detectors (TLD).

Investigation of the Effect of Some Optically Active Imine Compounds on the Enzyme Activities of hCA‐I and hCA‐II under In Vitro Conditions: An Experimental and Theoretical Study

Inhibitors of carbonic anhydrase (hCA; EC 4.2.1.1) are used as medicines for many diseases. Therefore, they are very important. In this study, a known series of Schiff bases were synthesized and their effects on the activities of hCA‐I and hCA‐II, which are cytosolic isoenzymes of carbonic anhydrase, were investigated under in vitro conditions. The synthesized compounds (H1, H2, H3, and H4) were found to cause inhibition on enzyme activities of hCA‐1 and hCA‐II. IC₅₀ values of H1, H2, H3, and H4 compounds were 140, 88, 201, and 271 μM for hCA‐I enzyme activity and 134, 251, 79, and 604 μM for hCA‐II enzyme activity, respectively. The synthesized Schiff bases were characterized by several methods, including ¹H NMR, FT‐IR, elemental analysis, and polarimetric measurements. Correlation coefficient square values (R²) of comparison of the theoretical and experimental ¹H NMR shifts for H1, H2, H3, and H4 compounds were found as 0.9781, 0.9814, 0.9758, and 0.8635, respectively.     

An update comprehensive review on the status of COVID-19: vaccines,drugs, variants and neurological symptoms

Various recently reported mutant variants, candidate and urgently approved current vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), many current situations with severe neurological damage and symptoms as well as respiratory tract disorders have begun to be reported. In particular, drug, vaccine, and neutralizing monoclonal antibodies (mAbs) have been developed and are currently being evaluated in clinical trials. Here, we review lessons learned from the use of novel mutant variants of the COVID-19 virus, immunization, new drug solutions, and antibody therapies for infections. Next, we focus on the B 1.1.7, B 1.351, P.1, and B.1.617 lineages or variants of concern that have been reported worldwide, the new manifestations of neurological manifestations, the current therapeutic drug targets for its treatment, vaccine candidates and their efficacy, implantation of convalescent plasma, and neutralization of mAbs. We review specific clinical questions, including many emerging neurological effects and respiratory tract injuries, as well as new potential biomarkers, new studies in addition to known therapeutics, and chronic diseases of vaccines that have received immediate approval. To answer these questions, further understanding of the burden kinetics of COVID-19 and its correlation with neurological clinical outcomes, endogenous antibody responses to vaccines, pharmacokinetics of neutralizing mAbs, and action against emerging viral mutant variants is needed.     

A validated antibody panel for the characterization of tau post-translational modifications

Background

Tau is a microtubule-binding protein, which is subject to various post-translational modifications (PTMs) including phosphorylation, methylation, acetylation, glycosylation, nitration, sumoylation and truncation. Aberrant PTMs such as hyperphosphorylation result in tau aggregation and the formation of neurofibrillary tangles, which are a hallmark of Alzheimer’s disease (AD). In order to study the importance of PTMs on tau function, antibodies raised against specific modification sites are widely used. However, quality control of these antibodies is lacking and their specificity for particular modifications is often unclear.

Methods

In this study, we first designed an online tool called ‘TauPTM’, which enables the visualization of PTMs and their interactions on human tau. Using TauPTM, we next searched for commercially available antibodies against tau PTMs and characterized their specificity by peptide array, immunoblotting, electrochemiluminescence ELISA and immunofluorescence technologies.

Results

We demonstrate that commercially available antibodies can show a significant lack of specificity, and PTM-specific antibodies in particular often recognize non-modified versions of the protein. In addition, detection may be hindered by other PTMs in close vicinity, complicating the interpretation of results. Finally, we compiled a panel of specific antibodies and show that they are useful to detect PTM-modified endogenous tau in hiPSC-derived neurons and mouse brains.

Conclusion

This study has created a platform to reliably and robustly detect changes in localization and abundance of post-translationally modified tau in health and disease. A web-based version of TauPTM is fully available at http://www.tauptm.org.

     

Single-stage photofermentative biohydrogen production from sugar beet molasses by different purple non-sulfur bacteria

Bioprocess and Biosystems Engineering - Biohydrogen production via fermentative routes offers considerable advantages in waste recycling and sustainable energy production. This can be realized by...