Kinematic and dynamic gait compensations resulting from knee instability in a rat model of osteoarthritis

Introduction

Osteoarthritis (OA) results in pain and disability; however, preclinical OA models often focus on joint-level changes. Gait analysis is one method used to evaluate both preclinical OA models and OA patients. The objective of this study is to describe spatiotemporal and ground reaction force changes in a rat medial meniscus transection (MMT) model of knee OA and to compare these gait measures with assays of weight bearing and tactile allodynia.

Methods

Sixteen rats were used in the study. The medial collateral ligament (MCL) was transected in twelve Lewis rats (male, 200 to 250 g); in six rats, the medial meniscus was transected, and the remaining six rats served as sham controls. The remaining four rats served as naïve controls. Gait, weight-bearing as measured by an incapacitance meter, and tactile allodynia were assessed on postoperative days 9 to 24. On day 28, knee joints were collected for histology. Cytokine concentrations in the serum were assessed with a 10-plex cytokine panel.

Results

Weight bearing was not affected by sham or MMT surgery; however, the MMT group had decreased mechanical paw-withdrawal thresholds in the operated limb relative to the contralateral limb (P = 0.017). The gait of the MMT group became increasingly asymmetric from postoperative days 9 to 24 (P = 0.020); moreover, MMT animals tended to spend more time on their contralateral limb than their operated limb while walking (P < 0.1). Ground reaction forces confirmed temporal shifts in symmetry and stance time, as the MMT group had lower vertical and propulsive ground reaction forces in their operated limb relative to the contralateral limb, naïve, and sham controls (P < 0.05). Levels of interleukin 6 in the MMT group tended to be higher than naïve controls (P = 0.072). Histology confirmed increased cartilage damage in the MMT group, consistent with OA initiation. Post hoc analysis revealed that gait symmetry, stance time imbalance, peak propulsive force, and serum interleukin 6 concentrations had significant correlations to the severity of cartilage lesion formation.

Conclusion

These data indicate significant gait compensations were present in the MMT group relative to medial collateral ligament (MCL) injury (sham) alone and naïve controls. Moreover, these data suggest that gait compensations are likely driven by meniscal instability and/or cartilage damage, and not by MCL injury alone.     

Antioxidant responses of halophyte plant Aeluropus littoralis under long-term salinity stress

Salinity influences the agricultural production all over the world. This constrain, similar to others biotic and abiotic stresses generate the reactive oxygen species such as superoxide, hydrogen peroxide and hydroxyl radicals. In the evolution process of halophyte plants the mechanisms to detoxify ROS, such as antioxidant enzymes, have been developed. Aeluropus littoralis is a special halophyte that selected to our research, so the plants treated with NaCl at different salt concentration (0, 250, 450 and 650 mM) for a period 45 days. Leaves and roots (separately) collected and their proteins extracted for superoxide dismutase (SOD), catalase (CAT), ascorbate peroxidase (APX) and peroxidase (POD) activity assay. Meanwhile the electrolyte leakage of leaves analyzed and increased at 450 and 650 mM of NaCl concentrations. Superoxide dismutase and catalase showed same pattern for changing in enzymatic activities (increasing activity by salt stress in roots and decreasing in shoot at 450 and 650 mM stress), also peroxidase and ascorbate peroxidase activity almost increased in all stress conditions.     

The use of previous crops as sustainable and eco-friendly management to fight Fusarium oxysporum in sesame plants

Sesame (Sesamum indicum L.), the “Queen of oil seeds” is being infected with pathogens, i.e., fungi, bacteria, virus and nematodes. Fusarium oxysporum sp. sesami (Zap.), is one of the fiercest pathogens causing severe economic losses on sesame. This work aimed to evaluate the impact of the cultivation of some preceding crops and seed inoculation with antagonistic predominant rhizospheric bacteria and actinomycetes on the incidence and development of Fusarium damping-off and wilt disease. Results showed that the lowest pre and/or post-emergence damping-off and wilt of sesame were recorded after onion and garlic, followed by wheat compared to clover in both the 2019 and 2020 seasons. In vitro, soil extracts from plots where onion and garlic have been cultivated slightly decreased the conidia germination and mycelium radial growth of F. oxysporum. The numbers of sesame rhizospheric F. oxysporum and fungi were lower after the cultivation of onion and garlic than those after wheat and clover. However, the numbers of actinomycetes and bacteria were higher in the onion, garlic, and clover rhizosphere than wheat. Among all isolated bacteria and actinomycetes associated with sesame roots cultivated after preceding plants, the Tricoderma viride and Bacillus subtilis (isolate No.3) profoundly reduce F. oxysporum mycelial growth in vitro. When sesame seeds were inoculated with Tricoderma viride, Bacillus subtilis, Streptomyces rochei and Pseudomonas fluorescens, the disease incidence of damping-off and wilt significantly decreased in the greenhouse and field trials conducted in both tested growing seasons, also had highly significant on plant health and growth parameters. Therefore, the current study suggested that using the preceding onion and garlic plants could be used for eco-friendly reduction of damping-off and wilt disease of sesame.     

Antimicrobial Pyridazines: Synthesis,Characterization, Cytotoxicity,Substrate Promiscuity,and Molecular Docking

A facile and convenient synthesis of new pyridazines suitable for use as antimicrobial agents was reported. The hydrazide intermediate was coupled with various benzaldehydes and/or acetophenones and cyclized instantaneously to afford target pyridazine derivatives. The structures of new pyridazines were confirmed by IR, ¹H‐ and ¹³C‐NMR, elemental analysis in addition to representative LC/MS. Antimicrobial activity was screened against 10 bacterial and fungal strains. The new pyridazines showed strong to very strong antibacterial activity against Gram‐negative (GNB) bacteria, while none of them showed significant antifungal activity at the same concentration range. Chloro derivatives exhibited the highest antibacterial activity with MICs (0.892–3.744 μg/mL) lower than that of chloramphenicol (2.019–8.078 μg/mL) against E. coli, P. aeruginosa, and S. marcescens. Prediction of ADME parameters, pharmacokinetics, and substrate promiscuity revealed that these new pyridazines could be promising drug candidates. Cytotoxic studies on rat hepatocytes showed how much safe these new pyridazines on living organisms (IC₅₀>64 μg/mL). MOE docking studies showed a good overlay of these new pyridazines with co‐crystallized ligand within an E. coli DNA gyrase subunit B active sites (4KFG).     

Targeting ERK/COX-2 signaling pathway in permethrin-induced testicular toxicity: a possible modulating effect of matrine

Molecular Biology Reports - Permethrin (PER), the prevalent synthetic pyrethroid, was reported to have genotoxic effects along with male reproductive organs impairment. Matrine, the Chinese herb...     

The effect of magnetized water on the oxidation reaction of phenol derivatives and aromatic amines by horseradish peroxidase enzyme

The present study aimed to investigate, for the first time, the rate of the oxidation reaction of some derivatives of phenol and aromatic amines, that is, pyrogallol, catechol, resorcinol, ortho-aminophenol, meta-aminophenol, para-aminophenol, ortho-phenylenediamine, and para-phenylenediamine, in the presence of hydrogen peroxide in pure and magnetized solvents using horseradish peroxidase enzyme. The reaction was studied in the absence and presence of a magnetized solvent under completely identical conditions. The results showed that magnetized solvent could change the structure of the enzyme and reduce its activity. In addition, it affected the rate of oxidation of the selected derivatives through altering the strength of the hydrogen bonds of the system. The changes in the structure and activity of the enzyme were examined using UV–Vis and fluorescence spectroscopy as well as viscosity measurement technique. Examination of the secondary structure via the far UV-CD spectrum indicated the increase in the alpha helical structure in the magnetized solvent. When dissolved in a magnetized solvent, hydrogen peroxide as an enzyme substrate reduced the rate of enzymatic reaction and provided lower saturation conditions for the enzyme compared with when it was dissolved in the pure solvent.     

Taguchi array optimization of the reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for sensitive and rapid detection of dengue virus serotype 2

Biotechnology Letters - Serotype 2 of dengue virus (DENV-2) is the most prevalent cause of dengue fevers. In this study, the C-prM gene was used for specific detection of DENV-2 by RT-LAMP assay....     

Serum microRNA-33 levels in pre-diabetic and diabetic patients

Molecular Biology Reports - Diabetes mellitus (DM) is a metabolic disease characterized by hyperglycemia and abnormal insulin secretion. MicroRNAs are small, non-coding RNAs that are able to affect...     

Synthesis of some quinazolinones inspired from the natural alkaloid L-norephedrine as EGFR inhibitors and radiosensitizers

A set of quinazolinones synthesized by the aid of L-norephedrine was assembled to generate novel analogues as potential anticancer and radiosensitizing agents. The new compounds were evaluated for their cytotoxic activity against MDA-MB-231, MCF-7, HepG-2, HCT-116 cancer cell lines and EGFR inhibitory activity. The most active compounds 5 and 6 were screened against MCF-10A normal cell line and displayed lower toxic effects. They proved their relative safety with high selectivity towards MDA-MB-231 breast cancer cell line. Measurement of the radiosensitizing activity for 5 and 6 revealed that they could sensitize the tumour cells after being exposed to a single dose of 8 Gy gamma radiation. Compound 5 was able to induce apoptosis and arrest the cell cycle at the G2-M phase. Molecular docking of 5 and 6 in the active site of EGFR was performed to gain insight into the binding interactions with the key amino acids.     

Evaluation of Induced Apoptosis by Biosynthesized Zinc Oxide Nanoparticles in MCF-7 Breast Cancer Cells Using Bak1 and Bclx Expression

Doklady Biochemistry and Biophysics - Zinc oxide nanoparticles (ZnO NPs) have peaked interests in many researches in these recent years due to their advantageous application in modern health care...