Molecular effects of polystyrene nanoplastics on human neural stem cells

by Raquel Martin-Folgar, Mª Carmen González-Caballero, Mónica Torres-Ruiz, Ana I. Cañas-Portilla, Mercedes de Alba González, Isabel Liste, Mónica Morales

Nanoplastics (NPs) have been found in many ecological environments (aquatic, terrestrial, air). Currently, there is great concern about the exposition and impact on animal health, including humans, because of the effects of ingestion and accumulation of these nanomaterials (NMs) in aquatic organisms and their incorporation into the food chain. NPs´ mechanisms of action on humans are currently unknown. In this study, we evaluated the altered molecular mechanisms on human neural stem cell line (hNS1) after 4 days of exposure to 30 nm polystyrene (PS) NPs (0.5, 2.5 and 10 μg/mL). Our results showed that NPs can induce oxidative stress, cellular stress, DNA damage, alterations in inflammatory response, and apoptosis, which could lead to tissue damage and neurodevelopmental diseases.

Gait analysis: An effective tool to mechanically monitor the bone regeneration of critical-sized defects in tissue engineering applications

by Pablo Blázquez-Carmona, Juan Mora-Macías, Juan Morgaz, María del Mar Granados, Jaime Domínguez, Esther Reina-Romo

Introduction

Tissue engineering has emerged as an innovative approach to treat critical-size bone defects using biocompatible scaffolds, thus avoiding complex distraction surgeries or limited stock grafts. Continuous regeneration monitoring is essential in critical-size cases due to the frequent appearance of non-unions. This work evaluates the potential clinical use of gait analysis for the mechanical assessment of a tissue engineering regeneration as an alternative to the traditional and hardly conclusive manual or radiological follow-up.

Materials and methods

The 15-mm metatarsal fragment of eight female merino sheep was surgically replaced by a bioceramic scaffold stabilized with an external fixator. Gait tests were performed weekly by making the sheep walk on an instrumented gangway. The evolution of different kinematic and dynamic parameters was analyzed for all the animal’s limbs, as well as asymmetries between limbs. Finally, potential correlation in the recovery of the gait parameters was evaluated through the linear regression models.

Results

After surgery, the operated limb has an altered way of carrying body weight while walking. Its loading capacity was significantly reduced as the stance phases were shorter and less impulsive. The non-operated limbs compensated for this mobility deficit. All parameters were normalizing during the consolidation phase while the bone callus was simultaneously mineralizing. The results also showed high levels of asymmetry between the operated limb and its contralateral, which exceeded 150% when analyzing the impulse after surgery. Gait recovery significantly correlated between symmetrical limbs.

Conclusions

Gait analysis was presented as an effective, low-cost tool capable of mechanically predicting the regeneration of critical-size defects treated by tissue engineering, as comparing regeneration processes or novel scaffolds. Despite the progressive normalization as the callus mineralized, the bearing capacity reduction and the asymmetry of the operated limb were more significant than in other orthopedic alternatives.

Latent class analyses of multimorbidity and all-cause mortality: A prospective study in Chilean adults

by Gabriela Nazar, Felipe Díaz-Toro, Yeny Concha-Cisternas, Ana María Leiva-Ordoñez, Claudia Troncoso-Pantoja, Carlos Celis-Morales, Fanny Petermann-Rocha

Multimorbidity patterns can lead to differential risks for all-cause mortality. Within the Chilean context, research on morbidity and mortality predominantly emphasizes individual diseases or combinations thereof, rather than specific disease clusters. This study aimed to identify multimorbidity patterns, along with their associations with mortality, within a representative sample of the Chilean population. 3,701 participants aged ≥18 from the Chilean National Health Survey 2009–2010 were included in this prospective study. Multimorbidity patterns were identified from 16 chronic conditions and then classified using latent class analyses. All-cause mortality data were extracted from the Chilean Civil Registry. The association of classes with all-cause mortality was carried out using Cox proportional regression models, adjusting by sociodemographic and lifestyle variables. Three classes were identified: a) Class 1, the healthiest (72.1%); b) Class 2, the depression/cardiovascular disease/cancer class (17.5%); and c) Class 3, hypertension/chronic kidney disease class (10.4%). Classes 2 and 3 showed higher mortality risk than the healthiest class. After adjusting, Class 2 showed 45% higher mortality risk, and Class 3 98% higher mortality risk, compared with the healthiest class. Hypertension appeared to be a critical underlying factor of all-cause morbidity. Particular combinations of chronic diseases have a higher excess risk of mortality than others.

Rates of subsequent surgeries after meniscus repair with and without concurrent anterior cruciate ligament reconstruction

by Joseph B. Kahan, Patrick Burroughs, Logan Petit, Christopher A. Schneble, Peter Joo, Jay Moran, Maxwell Modrak, William Mclaughlin, Adam Nasreddine, Jonathan N. Grauer, Michael J. Medvecky

Objectives

The purpose of this study was to compare the rates of secondary knee surgery for patients undergoing meniscus repair with or without concurrent anterior cruciate ligament reconstruction (ACLr).

Methods

Utilizing a large national database, patients with meniscal repair with or without concurrent arthroscopic ACLr were identified. The two cohorts were then queried for secondary surgical procedures of the knee within the following 2 years. Frequency, age distribution, rates of secondary surgery, and type of secondary procedures performed were compared.

Results

In total, 1,585 patients were identified: meniscus repair with ACLr was performed for 1,006 (63.5%) and isolated meniscal repair was performed for 579 (36.5%). Minimum of two year follow up was present for 487 (30.7% of the overall study population).Secondary surgery rates were not significantly different between meniscus repair with concurrent ACLr and isolated meniscus repairs with an overall mean follow up of 13 years (1.5–24 years) (10.6% vs. 13.6%, p = 0.126). For the 2 year follow up cohort, secondary surgery rates were not significantly different (19.3% vs. 25.6%, p = 0.1098). There were no differences in survivorship patterns between the two procedures, both in the larger cohort (p = 0.2016), and the cohort with minimum 2-year follow-up (p = 0.0586).

Conclusion

The current study assessed secondary surgery rates in patients undergoing meniscus repair with or without concurrent ACLr in a large patient database. Based on this data, no significant difference in rates of secondary knee surgery was identified.

Anethole attenuates motor dysfunctions, striatal neuronal activity deficiency and blood brain barrier permeability by decreasing striatal α-synuclein and oxidative stress in rotenone-induced Parkinson’s disease of male rats

by Sadegh Moradi Vastegani, Seyed Esmaeil Khoshnam, Samireh Ghafouri, Nima Bakhtiari, Yaghoob Farbood, Alireza Sarkaki

Introduction

Anethole is the main compound of the essential oil of anise and several other plants, which has antioxidant, anti-inflammatory, and neuroprotective properties. Oxidative stress is considered as an important factor in the pathogenesis of PD. In the present study, we aimed to investigate the effects of anethole against rotenone-induced PD.

Methods

Male Wistar rats were randomly divided into six groups. Control group received DMSO + sunflower oil, model group received rotenone (2 mg/kg, s.c, daily for 35 days), positive control group received L-Dopa, and test groups received anethole (62.5, 125, and 250 mg/kg, i.g, daily for 35 days) 1 hour before each rotenone injection. Body weight changes, rotarod test, stride length test, and extracellular single unit recording were performed after treatment. After behavioral test, Brain water content and blood brain barrier (BBB) permeability were evaluated, and the levels of malondialdehyde (MDA), superoxide dismutases (SOD), alpha-synuclein and MAO-B were measured in the striatum.

Results

Chronic administration of rotenone induced body weight loss and caused significant dysfunction in locomotor activity, neuronl firing rate, and BBB. Rotenone also decreased SOD activity, increased MDA level, and elevated the expression of alpha-synuclein and MAO-B in the striatum. However, treatment with anethole attenuated body weight loss, motor function, neuronal activity, and BBB function. Furthermore, Anethole treatment attenuated oxidative stress and decreased the expression of alpha-synuclein and MAO-B compared to the rotenone group.

Conclusion

Our results show that through its antioxidant properties, aethole can improve the cellular, molecular and behavioral characteristics of rotenone-induced Parkinson’s disease.