Targeting of human fibroblast growth factor receptor 2 by a novel specific nanobody

Inhibition of FGFR2 signaling is promising in targeted therapy of FGFR2-related tumors. In this study, anti-FGFR2 nanobodies (Nbs) were isolated through screening of an immune camelid phage display library. Four rounds of biopanning were carried out with commercial human FGFR2 antigen and enrichment was assessed by ELISA and phage titration. The gene of Nb was sub-cloned into the expression vector, and the recombinant vector was transformed into Escherichia coli WK6 cells. The recombinant protein was purified using Ni-NTA affinity chromatography. The anti-FGFR2 Nb (C13) was characterized by SDS-PAGE, western blotting, competitive inhibition ELISA, flow cytometry, MTT, and migration assay. C13 Nb recognized FGFR2 with high specificity and no cross-reactivity was observed with other tested antigens. The affinity of C13 Nb was calculated to be 1.5 × 10-9 M. Results of cytotoxicity showed that C13 Nb (10 µg/ml) inhibited 85% of the proliferation of T-47D cells (p < 0.001). In addition, C13 inhibited the migration of 68% of T-47D toward the source of the growth factor (p < 0.01). The flow cytometry showed that C13 Nb bound to the surface of FGFR2+ cells, T-47D cell line (96%). Results indicate the potential of anti-FGFR2 Nb for targeted therapy of FGFR2-overexpressing tumors after complementary investigations.

Identifying SARS-CoV-2 main protease inhibitors by applying the computer screening of a large database of molecules

The outbreak of coronavirus disease 2019 (COVID-19) at the end of 2019 affected global health. Its infection agent was called severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Wearing a mask, maintaining social distance, and vaccination are effective ways to prevent infection of SARS-CoV-2, but none of them help infected people. Targeting the enzymes of SARS-CoV-2 is an effective way to stop the replication of the virus in infected people and treat COVID-19 patients. SARS-CoV-2 main protease is a therapeutic target which the inhibition of its enzymatic activity prevents from the replication of SARS-CoV-2. A large database of molecules has been searched to identify new inhibitors for SARS-CoV-2 main protease enzyme. At the first step, ligand screening based on similarity search was used to select similar compounds to known SARS-CoV-2 main protease inhibitors. Then molecules with better predicted pharmacokinetic properties were selected. Structure-based virtual screening based on the application of molecular docking and molecular dynamics simulation methods was used to select more effective inhibitors among selected molecules in previous step. Finally two compounds were considered as SARS-CoV-2 main protease inhibitors.

Biological Activities and the Essential Oil Analysis of Cousinia harazensis and C. calocephala

This research aimed to evaluate the cytotoxicity, anti-bacterial, anti-fungal and heme polymerization inhibition activities, as well as the detection of the chemical composition of essential oils and measurement of the amount of total phenol and flavonoids of Cousinia harazensis and C. calocephala. In-vitro growth inhibitory effects of methanol extracts on A2780, T-47D, A549 and Hep-G2 cells were evaluated by MTT assay. MIC and MBC/MFC were determined by the agar dilution method. The anti-malarial activity of herbs was assessed with an inhibition test of heme detoxification (ITHD). Total phenol and flavonoids content measured by Folin-Ciocalteu method. The essential oils from two herbs were extracted by hydro-distillation, and GC/MS analyzed their compositions. Cell studies against selected cell lines growth in MTT assay were related to C. harazensis on Hep-G2 with IC₅₀ of 4.521 µg/mL. The MIC of anti-bacterial and anti-fungal effects is related to C. harazensis extract on Staphylococcus epidermidis and Aspergillus fumigatus with 15.62 and 62.5 mg/mL, respectively. Both extracts do not have anti-malarial activity. C. harzensis content was richer in total phenol and flavonoids rather than the other herb. m-benzyl benzyl alcohol (46.7%) and butyl phthalate (14.7%) are the major compounds of C. harazensis; main components of C. calocephala are 3-methyl-tetrahydrofuran (24.6%) and oleic acid (15.4%). In conclusion, C. harazensis with more phenol and flavonoids content showed better results in terms of biological activities.

Synthesis of novel amodiaquine analogs and evaluation of their in vitro and in vivo antimalarial activities

BACKGROUND & OBJECTIVES

Due to the rapid increase of drug resistance in Plasmodium parasites, there is a pressing need of developing new antiplasmodial drugs. In this study, new amodiaquine (AQ) analogs were synthesized, followed by an evaluation of their antiplasmodial activity.

METHODS

A new series of quinoline derivatives containing N-alkyl (piperazin-1-yl)methyl benzamidine moiety was synthesized by reacting 4-[(4-(7-chloroquinolin-4-yl)piperazin-1-yl)methyl]benzonitrile with appropriate primary amines. The synthesized compounds were investigated for inhibitory activity by inhibition test of heme detoxification (ITHD). Their antiplasmodial activity was then evaluated using the classical 4-day suppressive test (Peter's test) against Plasmodium berghei-infected mice (ANKA strain).

RESULTS

The results showed that the percentage of heme detoxification inhibition in the active compounds was 90%. The most promising analogs, N-butyl-4-[(4-(7-chloroquinolin-4-yl)piperazin-1-yl)methyl]benzamidine (compound 1e), and 4-[(4-(7-chloroquinolin-4-yl)piperazin-1-yl)methyl)]-N-(4-methylpentan-2-yl)benzamidine (compound 1f) displayed 97.65 and 99.18% suppressions at the doses of 75 and 50 mg/kg/day, respectively. Further, the mean survival time of the mice treated with these compounds was higher than that of the negative control group.

INTERPRETATION & CONCLUSION

The newly synthesized amodiaquine analogs presented sufficient antiplasmodial activity with excellent suppressions and high in vitro heme detoxification inhibition. Higher mean survival time of the mice treated with synthetic compounds further confirmed the in vivo antimalarial activity of these new AQ analogs. Therefore, these compounds have the potential to replace common drugs from 4-aminoquinoline class. However, further investigations such as pharmacokinetic evaluations, cytotoxicity, toxicity, and formulation seem to be necessary.

No effect of ovarian stimulation and oocyte yield on euploidy and live birth rates: an analysis of 12 298 trophectoderm biopsies

STUDY QUESTION

Does ovarian stimulation affect embryo euploidy rates or live birth rates (LBRs) after transfer of euploid embryos?

SUMMARY ANSWER

Euploidy rates and LBRs after transfer of euploid embryos are not significantly influenced by gonadotropin dosage, duration of ovarian stimulation, estradiol level, follicle size at ovulation trigger or number of oocytes retrieved, regardless of a woman’s age.

WHAT IS KNOWN ALREADY

Aneuploidy rates increase steadily with age, reaching &gt;80% in women &gt;42 years old. The goal of ovarian stimulation is to overcome this high aneuploidy rate through the recruitment of several follicles, which increases the likelihood of obtaining a euploid embryo that results in a healthy conceptus. However, several studies have suggested that a high response to stimulation might be embryotoxic and/or increase aneuploidy rates by enhancing abnormal segregation of chromosomes during meiosis. Furthermore, a recent study demonstrated a remarkable difference in euploidy rates, ranging from 39.5 to 82.5%, among young oocyte donors in 42 fertility centres, potentially suggesting an iatrogenic etiology resulting from different stimulation methods.

STUDY DESIGN, SIZE, DURATION

This is a retrospective cohort study that included 2230 in vitro fertilisation (IVF) with preimplantation genetic testing for aneuploidy (PGT-A) cycles and 930 frozen-thawed single euploid embryo transfer (FET) cycles, performed in our centre between 2013 and 2017.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A total of 12 298 embryos were analysed for ploidy status. Women were divided into five age groups (&lt;35, 35–37, 38–40, 41–42 and &gt;42 years old). Outcomes were compared between different durations of stimulation (&lt;10, 10–12 and ≥13 days), total gonadotropin dosages (&lt;4000, 4000–6000 and &gt;6000 IU), numbers of oocytes retrieved (&lt;10, 10–19 and ≥20 oocytes), peak estradiol levels (&lt;2000, 2000–3000 and &gt;3000 pg/mL), and sizes of the largest follicle on the day of trigger (&lt;20 and ≥20 mm).

MAIN RESULTS AND THE ROLE OF CHANCE

Within the same age group, both euploidy rates and LBRs were comparable between cycles regardless of their differences in total gonadotropin dosage, duration of stimulation, number of oocytes harvested, size of the largest follicles or peak estradiol levels. In the youngest group, (&lt;35 years, n = 3469 embryos), euploidy rates were comparable between cycles with various total gonadotropin dosages (55.6% for &lt;4000 IU, 52.9% for 4000–6000 IU and 62.3% for &gt;6000 IU; P = 0.3), durations of stimulation (54.4% for &lt;10 days, 55.2% for 10–12 days and 60.9% for &gt;12 days; P = 0.2), number of oocytes harvested (59.4% for &lt;10 oocytes, 55.2% for 10–19 oocytes and 53.4% for ≥20 oocytes; P = 0.2), peak estradiol levels (55.7% for E2 &lt; 2000 pg/mL, 55.4% for E2 2000–3000 pg/mL and 54.8% for E2 &gt; 3000 pg/mL; P = 0.9) and sizes of the largest follicle (55.6% for follicles &lt;20 mm and 55.1% for follicles ≥20 mm; P = 0.8). Similarly, in the oldest group (&gt;42 years, n = 1157 embryos), euploidy rates ranged from 8.7% for gonadotropins &lt;4000 IU to 5.1% for gonadotropins &gt;6000 IU (P = 0.3), from 10.8% for &lt;10 days of stimulation to 8.5% for &gt;12 days of stimulation (P = 0.3), from 7.3% for &lt;10 oocytes to 7.4% for ≥20 oocytes (P = 0.4), from 8.8% for E2 &lt; 2000 pg/mL to 7.5% for E2 &gt; 3000 pg/mL (P = 0.8) and from 8.2% for the largest follicle &lt;20 mm to 8.9% for ≥20 mm (P = 0.7). LBRs after single FET were also comparable between these groups.

LIMITATIONS, REASONS FOR CAUTION

Although this large study (2230 IVF/PGT-A cycles, 12 298 embryos and 930 single FET cycles) demonstrates the safety of ovarian stimulation in terms of aneuploidy and implantation potential of euploid embryos, a multi-centre study may help to prove the generalisability of our single-centre data.

WIDER IMPLICATIONS OF THE FINDINGS

These findings reassure providers and patients that gonadotropin dosage, duration of ovarian stimulation, estradiol level, follicle size at ovulation trigger and number of oocytes retrieved, within certain ranges, do not appear to significantly influence euploidy rates or LBRs, regardless of the woman’s age.

STUDY FUNDING/COMPETING INTEREST(S)

No external funding was received and there are no competing interests to declare.

TRIAL REGISTRATION NUMBER

N/A

Differential frontal alpha oscillations and mechanisms underlying loss of consciousness: a comparison between slow and fast propofol infusion rates

Mechanisms underlying loss of consciousness following propofol administration remain incompletely understood. The objective of this study was to compare frontal lobe electroencephalography activity and brainstem reflexes during intravenous induction of general anaesthesia, in patients receiving a typical bolus dose (fast infusion) of propofol compared with a slower infusion rate. We sought to determine whether brainstem suppression ('bottom-up') predominates over loss of cortical function ('top-down'). Sixteen ASA physical status-1 patients were randomly assigned to either a fast or slow propofol infusion group. Loss of consciousness and brainstem reflexes were assessed every 30 s by a neurologist blinded to treatment allocation. We performed a multitaper spectral analysis of all electroencephalography data obtained from each participant. Brainstem reflexes were present in all eight patients in the slow infusion group, while being absent in all patients in the fast infusion group, at the moment of loss of consciousness (p = 0.010). An increase in alpha band power was observed before loss of consciousness only in participants allocated to the slow infusion group. Alpha band power emerged several minutes after the loss of consciousness in participants allocated to the fast infusion group. Our results show a predominance of 'bottom-up' mechanisms during fast infusion rates and 'top-down' mechanisms during slow infusion rates. The underlying mechanisms by which propofol induces loss of consciousness are potentially influenced by the speed of infusion.

Theoretical Study of Kinetics and Mechanism of Reactions of Hydroxylamine and Amineoxide Anion with Methyl Iodide in Gas and Aqueous Phases

The kinetics and mechanism of the reactions of hydroxylamine and aminoxide anion with methyl iodide were studied with ab initio calculations, Monte-Carlo and QM/MM simulations in gas and aqueous phases. Geometrical parameters and charge calculations show that these reactions proceed through the SN2 (bimolecular nucleophilic displacement) mechanism only. The solvent effects on these reactions were studied by inserting water molecules in reaction media, Onsager model, Monte-Carlo and QM/MM simulations. Activation parameters indicate the expected variation in activation energy and rate coefficient in aqueous phase in comparison to the gas phase. The shift of potential energy barrier through the reactants or products for the studied reactions in the gas phase is in the opposite direction in comparison to the aqueous phase.

A Density Functional Theory Study of Cyclization of Citronellal

A theoretical study of the kinetics and mechanism of the cyclization of citronellal in the gas phase was performed using density functional theory methods at the B3LYP level of theory with 6-311G, 6-311G*, 6-31G**, 6-311G**, 6-311+G and 6-311 + +G basis sets at 298.15K, 433.15K, and 473.15K. Equilibrium molecular geometries and harmonic vibrational frequencies of the reactant, transition state and products were calculated. Rate constants and activation thermodynamic parameters were calculated and showed a fairly good agreement with experimental results. The effect of solvent polarity on the reaction was studied. These calculations indicated that the reaction proceeds through an asynchronous concerted mechanism.

Leaves Antimicrobial Activity of Glycyrrhiza glabra L

Licorice (Glycyrrhiza glabra L.) is an important medicinal plant. In this study, the antimicrobial activities of ethanolic and aqueous extracts from licorice leaves were studied compared to root extracts activities. Bacillus subtilis, Enterococcus faecalis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Escherichia coli, and Candida albicans were used as test organisms. Antimicrobial activity was tested by paper disc agar diffusion and serial dilution methods in order to determine minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The root and leave extracts showed activity against Candida albicans, and tested gram-positive bacteria in a dose dependent manner. The ethanolic extract of the leaves was the most active extract against gram-positive bacteria. Its effectiveness against strains provides hope that it can serve as an alternative therapeutic agent.