dose dependency
Recently Published Documents


TOTAL DOCUMENTS

278
(FIVE YEARS 26)

H-INDEX

39
(FIVE YEARS 3)

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Paula V. Monje ◽  
Ketty Bacallao ◽  
Gabriela I. Aparicio ◽  
Anil Lalwani

Abstract Background Heregulin is a ligand for the protooncogene product ErbB/HER that acts as  a key mitogenic factor for human Schwann cells (hSCs). Heregulin is required for sustained hSC growth in vitro but must be thoroughly removed before cell collection for transplantation due to potential safety concerns. The goal of this study was to develop simple cell-based assays to assess the effectiveness of heregulin addition to and removal from aliquots of hSC culture medium. These bioassays were based on the capacity of a β1-heregulin peptide to elicit ErbB/HER receptor signaling in adherent ErbB2+/ErbB3+ cells. Results Western blotting was used to measure the activity of three different β1-heregulin/ErbB-activated kinases (ErbB3/HER3, ERK/MAPK and Akt/PKB) using phospho-specific antibodies against key activating residues. The duration, dose-dependency and specificity of β1-heregulin-initiated kinase phosphorylation were investigated, and controls were implemented for assay optimization and reproducibility to detect β1-heregulin activity in the nanomolar range. Results from these assays showed that the culture medium from transplantable hSCs elicited no detectable activation of the aforementioned kinases in independent rounds of testing, indicating that the implemented measures can ensure that the final hSC product is devoid of bioactive β1-heregulin molecules prior to transplantation. Conclusions These assays may be valuable to detect impurities such as undefined soluble factors or factors for which other biochemical or biological assays are not yet available. Our workflow can be modified as necessary to determine the presence of ErbB/HER, ERK, and Akt activators other than β1-heregulin using native samples, such as fresh isolates from cell- or tissue extracts in addition to culture medium.


2021 ◽  
Vol 26 (42) ◽  
Author(s):  
Natalia Ruetalo ◽  
Ramona Businger ◽  
Michael Schindler

Background: The COVID-19 pandemic urges for cheap, reliable, and rapid technologies for disinfection and decontamination. One frequently proposed method is ultraviolet (UV)-C irradiation. UV-C doses necessary to achieve inactivation of high-titre SARS-CoV-2 are poorly defined. Aim: We investigated whether short exposure of SARS-CoV-2 to UV-C irradiation sufficiently reduces viral infectivity and doses necessary to achieve an at least 6-log reduction in viral titres. Methods: Using a box and two handheld systems designed to decontaminate objects and surfaces, we evaluated the efficacy of 254 nm UV-C treatment to inactivate surface dried high-titre SARS-CoV-2. Results: Drying for 2 hours did not have a major impact on the infectivity of SARS-CoV-2, indicating that exhaled virus in droplets or aerosols stays infectious on surfaces for at least a certain amount of time. Short exposure of high titre surface dried virus (3–5*10^6 IU/ml) with UV-C light (16 mJ/cm2) resulted in a total inactivation of SARS-CoV-2. Dose-dependency experiments revealed that 3.5 mJ/cm2 were still effective to achieve a > 6-log reduction in viral titres, whereas 1.75 mJ/cm2 lowered infectivity only by one order of magnitude. Conclusions: SARS-CoV-2 is rapidly inactivated by relatively low doses of UV-C irradiation and the relationship between UV-C dose and log-viral titre reduction of surface residing SARS-CoV-2 is nonlinear. Our findings emphasize that it is necessary to assure sufficient and complete exposure of all relevant areas by integrated UV-C doses of at least 3.5 mJ/cm2 at 254 nm. Altogether, UV-C treatment is an effective non-chemical option to decontaminate surfaces from high-titre infectious SARS-CoV-2.


Author(s):  
Sviatlana Pankavec ◽  
Jerzy Falandysz ◽  
Izabela Komorowicz ◽  
Alwyn R. Fernandes ◽  
Anetta Hanć ◽  
...  

AbstractIn an attempt to enrich the fruiting bodies with Lithium (Li), this study cultivated mushrooms using growing sets that were fortified with Li2O at 1.0, 5.0, 10, 50, 100 and 500 mg·kg−1 dw. Compost fortification up to 100 mg·kg−1 dw induced a dose-dependent increase in Li accumulation with resulting median mushroom concentrations of 2.0, 8.6, 16, 29 and 38 mg·kg−1 dw, respectively, relative to the unfortified control at 0.087 mg·kg−1 dw. The dose dependency appears to level off as Li2O addition approaches 100 mg·kg−1, suggesting that there is a limit to the ability of the species to accumulate/tolerate Li. Mushrooms did not grow at the 500 mg·kg−1 dw fortification level. At the highest viable level of fortification (100 mg·kg−1 dw), the fruiting bodies were around 440-fold richer in Li content than the control mushrooms. Additionally, the fortification at all levels up to 100 mg·kg−1 dw showed very low, if any, effect on the co-accumulation of the other, studied trace mineral constituents, with concentrations occurring at the lower range of those reported for commercial A. bisporus mushrooms.


Biomolecules ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 826
Author(s):  
Daniel Joseph ◽  
Johannes Schulze

Cannabinoid drugs are registered for postoperative nausea and emesis, Tourette syndrome and tumor-related anorexia, but are also used for spasticity and pain relief, among other conditions. Clinical studies for spasmolysis have been equivocal and even conclusions from meta-analyses were not consistent. This may be due to uncertainty in diagnostic criteria as well as a lack of direct spasmolytic activity (direct causality). In this review we used the Hill criteria to investigate whether a temporal association is causal or spurious. Methods: A systematic literature search was performed to identify all clinical trials of cannabinoids for spasticity. Studies were evaluated for dose dependency and time association; all studies together were analyzed for reproducibility, coherence, analogy and mechanistic consistency. A Funnel plot was done for all studies to identify selection or publication bias. Results: Twenty-seven studies were included in this meta-analysis. The spasmolytic activity (effect strength) was weak, with a nonsignificant small effect in most studies and a large effect only in a few studies (“enriched” studies, low patient numbers). No dose dependency was seen and plotting effect size vs. daily dose resulted in a slope of 0.004. Most studies titrated the cannabinoid to the optimum dose, e.g., 20 mg/d THC. The effect decreased with longer treatment duration (3–4 months). The spasmolytic effect is consistent for different European countries but not always within a country, nor is the effect specific for an etiology (multiple sclerosis, spinal cord injury, others). For other criteria like plausibility, coherence or analogous effects, no data exist to support or refute them. In most studies, adverse effects were frequently reported indicating a therapeutic effect only at high doses with relevant side effects. Conclusions: Current data do not support a specific spasmolytic effect; a general decrease in CNS activity analogous to benzodiazepines appears more likely. Whether individual patients or specific subgroups benefit from cannabinoids is unclear. Further studies should compare cannabinoids with other, nonspecific spasmolytic drugs like benzodiazepines.


Cancers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 2481
Author(s):  
Madjid Soltani ◽  
Farshad Moradi Kashkooli ◽  
Mohammad Souri ◽  
Samaneh Zare Harofte ◽  
Tina Harati ◽  
...  

Application of drugs in high doses has been required due to the limitations of no specificity, short circulation half-lives, as well as low bioavailability and solubility. Higher toxicity is the result of high dosage administration of drug molecules that increase the side effects of the drugs. Recently, nanomedicine, that is the utilization of nanotechnology in healthcare with clinical applications, has made many advancements in the areas of cancer diagnosis and therapy. To overcome the challenge of patient-specificity as well as time- and dose-dependency of drug administration, artificial intelligence (AI) can be significantly beneficial for optimization of nanomedicine and combinatorial nanotherapy. AI has become a tool for researchers to manage complicated and big data, ranging from achieving complementary results to routine statistical analyses. AI enhances the prediction precision of treatment impact in cancer patients and specify estimation outcomes. Application of AI in nanotechnology leads to a new field of study, i.e., nanoinformatics. Besides, AI can be coupled with nanorobots, as an emerging technology, to develop targeted drug delivery systems. Furthermore, by the advancements in the nanomedicine field, AI-based combination therapy can facilitate the understanding of diagnosis and therapy of the cancer patients. The main objectives of this review are to discuss the current developments, possibilities, and future visions in naoinformatics, for providing more effective treatment for cancer patients.


Plants ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 968
Author(s):  
Jin-Hong Kim ◽  
Kwon Hwangbo ◽  
Eujin Lee ◽  
Shubham Kumar Dubey ◽  
Moon-Soo Chung ◽  
...  

Transcriptome-based dose–response curves were recently applied to the phytodosimetry of gamma radiation in a dicot plant, Arabidopsis thaliana, as an alternative biological assessment of genotoxicity using DNA damage response (DDR) genes. In the present study, we characterized gamma ray-responsive marker genes for transcriptome-based phytodosimetry in a monocot plant, rice (Oryza sativa L.), and compared different phytodosimetry models between rice and Arabidopsis using gamma-H2AX, comet, and quantitative transcriptomic assays. The transcriptome-based dose–response curves of four marker genes (OsGRG, OsMutS, OsRAD51, and OsRPA1) were reliably fitted to quadratic or exponential decay equations (r2 > 0.99). However, the single or integrated dose–response curves of these genes were distinctive from the conventional models obtained by the gamma-H2AX or comet assays. In comparison, rice displayed a higher dose-dependency in the comet signal and OsRAD51 transcription, while the gamma-H2AX induction was more dose-dependent in Arabidopsis. The dose-dependent transcriptions of the selected gamma-ray-inducible marker genes, including OsGRG, OsMutS, OsRAD51, and OsRPA1 in rice and AtGRG, AtPARP1, AtRAD51, and AtRPA1E in Arabidopsis, were maintained similarly at different vegetative stages. These results suggested that the transcriptome-based phytodosimetry model should be further corrected with conventional genotoxicity- or DDR-based models despite the high reliability or dose-dependency of the model. In addition, the relative weighting of each gene in the integrated transcriptome-based dose–response model using multiple genes needs to be considered based on the trend and amplitude of the transcriptional change.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Mohamed Lotfy ◽  
Mohamad Ayaad

Abstract Background Preoperative anxiety has deleterious effects on patients’ outcome through its influence on intraoperative requirements of anesthetics and analgesics (Bayrak et al., J Coll Physicians Surg Pak 29:868–873, 2019), postoperative (PO) pain intensity, and analgesia requirement, and may even increase PO morbidity and mortality after certain types of surgery. Melatonin is a methoxyindole synthesized and secreted principally by the pineal gland at night under control of an endogenous rhythm of secretion generated by the suprachiasmatic nuclei. The current study hypothesized that preoperative melatonin could reduce patients’ anxiety and reduce intraoperative (IO) and postoperative (PO) analgesic in a dose-dependent manner. Results Preoperative consultation was, to some extent, effective in reducing patients’ anxiety and apprehension. At 1 h after receiving premedication, Anxiety Specific to Surgery Questionnaire (ASSQ) scores were significantly lower in study groups in comparison to baseline scores and at 1 h scores of P group patients (patients who received 3 ml of plain distilled water), and this significant effect extended for 3-h PO. The reported ∆∆ASSQ between study groups was 25.9% between M2 (melatonin) and Z (midazolam) groups and 36.9% between groups M1 (received melatonin in a dose of 3 mg) and M2 (received melatonin in a dose of 6 mg). Preoperative anxiolytic therapy allowed reduction of PO pain scores and analgesia consumption with prolongation of duration till 1st request of rescue analgesia, and these effects were more pronounced with melatonin 6 mg in comparison to placebo, melatonin 3mg, or midazolam. Conclusion Preoperative melatonin is an appropriate policy for reduction of preoperative anxiety and provided reduction of PO anxiety, pain scores, and consumption of analgesia thus promoting early recovery and short PO hospital stay. Dose dependency was evident, and preoperative melatonin 6-mg dose provided satisfactory effect.


2021 ◽  
Vol 19 ◽  
Author(s):  
Yusuf Cem Kaplan ◽  
Omer Demir

: It is challenging to balance the fetal risks associated with the use of antiepileptic drugs (AEDs) against maternal and fetal risks of seizure worsening and therefore it is very important to define and distinguish the possible risks entailed by different AEDs. This paper aims to undertake a comprehensive review regarding the possible risks of four classical (phenytoin, carbamazepine, phenobarbital and valproate) and two newer (lamotrigine and levetiracetam) AEDs during pregnancy. The review focuses on major and organ-specific malformations, dose-dependent risks, mono vs polytherapy, and clinical pharmacokinetics. A discussion regarding the safety of AED use during breastfeeding is also provided.


Sign in / Sign up

Export Citation Format

Share Document