A combined musculoskeletal and finite element model of a foot to predict plantar pressure distribution

In this study, a combined subject-specific numerical and experimental investigation was conducted to explore the plantar pressure of an individual. The research utilized finite element (FE) and musculoskeletal modelling based on computed tomography (CT) images of an ankle-foot complex and three-dimensional gait measurements. Muscle forces were estimated using an individualized multi-body musculoskeletal model in five gait phases. The results of the FE model and gait measurements for the same subject revealed the highest stress concentration of 0.48 MPa in the forefoot, which aligns with previously-reported clinical observations. Additionally, the study found that the encapsulated soft tissue FE model with hyper-elastic properties exhibited higher stresses compared to the model with linear-elastic properties, with maximum ratios of 1.16 and 1.88 MPa in the contact pressure and von-Mises stress, respectively. Furthermore, the numerical simulation demonstrated that the use of an individualized insole caused a reduction of 8.3% in the maximum contact plantar pressure and 14.7% in the maximum von-Mises stress in the encapsulated soft tissue. Overall, the developed model in this investigation holds potential for facilitating further studies on foot pathologies and the improvement of rehabilitation techniques in clinical settings.

The Nephroprotective Effect of In Utero Administration of Green Synthesized Titanium Dioxide Nanoparticles in Albino Rats

Titanium dioxide nanoparticles (TiO2-NPs) are one of the most popular nanoscale materials and have a wide range of applications in the manufacturing industry; nonetheless, researchers' focus has been directed to the detrimental consequences of TiO2-NPs. The current study was designed to assess the potential hazardous effects of chemically synthesized TiO2-NPs on the placenta and feto-maternal kidneys of rats. On the other hand, the probable positive impact of TiO2-NPs made after green synthesis was also evaluated. HepG2 cell lines were used to assess the cytotoxicity of chemical and green TiO2-NPs. Five groups of fifty pregnant female rats were formed (n=10). The first (control) group received distilled water. The second and third groups were orally given 100 and 300 mg/kg body weight (bw) of chemical TiO2-NPs, respectively. The fourth and fifth groups were orally given 100 and 300 mg/kg bw of green synthesized TiO2-NPs, respectively. On gestational day 20 (GD 20), blood and tissues were collected for biochemical and histological studies. Our findings revealed that chemical TiO2-NPs induced apoptosis in HepG2 cells at high concentrations, while there was no observed toxicity for green TiO2-NPs. The chemically treated TiO2-NPs groups showed a significant decrease in the level of HDL and a significant increase in cholesterol, LDL-cholesterol, and triglyceride levels. Renal tissues showed necrosis with exfoliation of lining epithelial cells, degenerated tubules, and glomerulonephritis. While the placenta was atrophied and hyalinized. Moreover, Bax expression significantly increased in the renal tubular cells and the villi of the placenta. Contrariwise, green TiO2-NPs-treated groups showed a significant rise in HDL levels with a significant reduction in triglycerides and LDL levels, while cholesterol levels were unaffected. Also, renal tissues showed mild degenerative changes in the glomeruli and renal tubules; thus, noticeable regeneration of epithelium lining tubules was detected in the maternal kidney. Bax showed a minimal reaction in the renal tubules and the villi of the placenta. It concluded that in contrast to chemical TiO2-NPs, biosynthesized TiO2-NPs with garlic showed a positive impact on the biochemical profile and histological investigations.

Genetic effects of chemically and biosynthesized titanium dioxide nanoparticles in vitro and in vivo of female rats and their fetuses

With the increase in nanoparticles (NPs) products on the market, the possibility of animal and human exposure to these materials will increase. The smaller size of NPs facilitates their entrance through placental barriers and allows them to accumulate in embryonic tissue, where they can then be a source of different developmental malformations. Several toxicity studies with chemically synthesized titanium dioxide NPs (CTiO2 NPs) have been recently carried out; although there is insufficient data on exposure to biosynthesized titanium dioxide NPs (BTiO2 NPs) during pregnancy, the study aimed to evaluate the ability of an eco-friendly biosynthesis technique using garlic extract against maternal and fetal genotoxicities, which could result from repeated exposure to TiO2 NPs during gestation days (GD) 6-19. A total of fifty pregnant rats were divided into five groups (n = 10) and gavaged CTiO2 NPs and BTiO2 NPs at 100 and 300 mg/kg/day concentrations. Pregnant rats on GD 20 were anesthetized, uterine horns were removed, and then embryotoxicity was performed. The kidneys of the mothers and fetuses in each group were collected and then maintained in a frozen condition. Our results showed that garlic extract can be used as a reducing agent for the formation of TiO2 NPs. Moreover, BTiO2 NPs showed less toxic potential than CTiO2 NPs in HepG2 cells. Both chemically and biosynthesized TiO2 NP-induced genetic variation in the 16S rRNA sequences of mother groups compared to the control group. In conclusion, the genetic effects of the 16S rRNA sequence induced by chemically synthesized TiO2 NPs were greater than those of biosynthesized TiO2 NPs. However, there were no differences between the control group and the embryo-treated groups with chemically and biologically synthesized TiO2 NPs.

Immunomodulatory and antioxidant effect of green synthesized titanium dioxide nanoparticles on pregnant female albino rats and their fetuses

Titanium dioxide nanoparticles (TiO2 NPs) are one of the various nanoparticles that have been increasingly commonly used in vital sectors. This study was aimed at evaluating the effects of prenatal exposure to the chemical TiO2 NPs (CHTiO2 NPs) and green-synthesized TiO2 NPs (GTiO2 NPs) on immunological and oxidative status as well as lungs and spleen. Fifty pregnant female albino rats were divided into five groups of ten rats each: control, CHTiO2 NPs-treated groups orally received 100 and 300 mg/kg CHTiO2 NPs, and GTiO2 NPs-treated groups received 100 and 300 mg/kg GTiO2 NPs, respectively, daily for 14 days. The serum level of proinflammatory cytokines IL-6, oxidative stress markers (MDA and NO), and antioxidant biomarkers (SOD and GSH-PX) were assayed. Spleen and lungs were collected from pregnant rats and fetuses for histopathological examinations. The results showed a significant increase in IL-6 levels in treated groups. In the CHTiO2 NPs-treated groups, there was a significant increase in MDA activity and a significant decrease in GSH-Px and SOD activities, revealing its oxidative effect, while GSH-Px and SOD activities significantly increased in the 300 GTiO2 NPs-treated group, confirming the antioxidant effect of green-synthesized TiO2 NPs. Histopathological findings of the spleen and lungs of the CHTiO2 NPs-treated group revealed severe congestion and thickening of the blood vessels, while those of the GTiO2 NPs-treated group revealed mild tissue alterations. It could be deduced that green synthesized titanium dioxide nanoparticles have immunomodulatory and antioxidant effects on pregnant female albino rats and their fetuses, with an ameliorated impact on the spleen and lung compared to chemical titanium dioxide nanoparticles.

Ameliorative effect of biosynthesized titanium dioxide nanoparticles using garlic extract on the body weight and developmental toxicity of liver in albino rats compared with chemically synthesized nanoparticles

The application of metallic nanoparticles poses risks to human and animal health. Titanium dioxide nanoparticles (TiO₂NPs) are the most commonly synthesized metallic oxides in the world. Exposure to TiO₂NPs can cause toxicity in the target organisms. This study aimed to evaluate the effects of green and chemical TiO₂NPs on maternal and embryo-fetal livers. Green TiO₂NPs using garlic extract (GTiO₂NPs) and chemical TiO₂NPs (CHTiO₂NPs) were synthesized and characterized by x-ray powder diffraction and high-resolution transmission electron microscopy. The cytotoxicity of both chemical and green TiO₂NPs was determined against HepG₂ cell lines. Fifty pregnant female Albino rats were equally and randomly divided into five groups. Group 1 was kept as a control. Groups 2 and 3 were orally treated with 100 and 300 mg/kg body weight of CHTiO₂NPs, respectively. Groups 4 and 5 were orally treated with 100 and 300 mg/kg of GTiO₂NPs, respectively, from day 6 to 19 of gestation. All dams were euthanized on gestation day 20. All live fetuses were weighed and euthanized. Blood and tissue samples were collected for biochemical, histopathological, and Bax-immunohistochemical expression analyses. Our results indicated that garlic could be used as a reducing agent for the synthesis of TiO₂NPs, and the produced NPs have no toxic effect against HepG₂ cells compared with CHTiO₂NPs. The maternal and fetal bodyweights were greatly reduced among the chemically TiO₂NPs induced animals. The mean serum level of AST and ALT activities and the total protein level significantly increased when TiO₂NPs were administered at high doses. Histologically, the CHTiO₂NPs-treated groups revealed vacuolated and necrotized hepatocytes with congested and dilated blood vessels in the fetal and maternal livers. The immunohistochemistry revealed distinct positive staining of Bax expressed in the hepatocytes. Nevertheless, the biosynthesis of TiO₂NPs using garlic extract had a minimal effect on the normal architecture of the liver. It could be concluded that the bioactivity of TiO₂NPs can be modified by green synthesis using garlic extract. Compared to the CHTiO₂NPs, the exposure to GTiO₂NPs showed reduced liver damage in maternal and embryo-fetal rats.

Stress distribution changes in growth plates of a trunk with adolescent idiopathic scoliosis following unilateral muscle paralysis: A hybrid musculoskeletal and finite element model

This study aimed to investigate changes occurred in the stress distribution in the growth plates (GPs) of a trunk with adolescent idiopathic scoliosis (AIS) following unilateral muscle paralysis. We hypothesized that weakening the appropriately chosen muscles on the concave side can decelerate AIS deformity progression. Muscle forces and reaction loads were estimated by an optimization-driven musculoskeletal (MS) model of adolescents with a normal- and an AIS trunk, and then applied on the finite element model of GPs of L1 through L4. Different set patterns of 95% reduction in the strength of the concave-side longissimus thoracis pars thoracic (LGPT), multifidus lumborum (MFL), and LGPT + MFL muscles were performed in the MS models. Results of this study showed that weakening of the concave-side MFL and LGPT muscles rendered a 35% correction in the symptomatic axial rotation of the AIS spine, and a reduction of about 25% in the compressive von Mises stress on the concave side of GPs, respectively, which can decelerate the deformity progression. It was observed that unilateral muscle weakening caused a compensatory activation of the rest of muscles to retain the spine stability. The intradiscal pressures and ratio between the rotations toward either side of the scoliotic spine, found here, matched well with some recent in-vivo investigations. One of the applications of the stability-based MS model of AIS spine with unilaterally weakened muscles presented in this study is to optimize the performance of the currently used braces. To fortify the presented therapeutic approach, experiments should be done on scoliotic animals.

Fulminant orbital cellulitis with complete loss of vision

Bacterial orbital cellulitis is a condition that rarely presents with complete loss of vision. A case is reported of a 69-year-old man who presented with fulminant onset of proptosis, significant ophthalmoplegia and no perception of light. Computed tomography showed no evidence of paranasal sinus disease. Despite treatment with intravenous flucloxacillin, ceftriaxone and metronidazole, and later, penicillin after Streptococcus pyogenes was grown from tissue culture, there was no improvement in vision; however ocular motility returned to normal.