Effects of various load magnitudes on ACL: an in vitro study using adolescent porcine stifle joints.

INTRODUCTION: The escalating incidence of anterior cruciate ligament (ACL) injuries, particularly among adolescents, is a pressing concern. The study of ACL biomechanics in this demographic presents challenges due to the scarcity of cadaveric specimens. This research endeavors to validate the adolescent porcine stifle joint as a fitting model for ACL studies. METHODS: We conducted experiments on 30 fresh porcine stifle knee joints. (Breed: Yorkshire, Weight: avg 90 lbs, Age Range: 2-4 months). They were stored at - 22 °C and a subsequent 24-h thaw at room temperature before being prepared for the experiment. These joints were randomly assigned to three groups. The first group served as a control and underwent only the load-to-failure test. The remaining two groups were subjected to 100 cycles, with forces of 300N and 520N, respectively. The load values of 300N and 520N correspond to three and five times the body weight (BW) of our juvenile porcine, respectively. RESULT: The 520N force demonstrated a higher strain than the 300N, indicating a direct correlation between ACL strain and augmented loads. A significant difference in load-to-failure (p = 0.014) was observed between non-cyclically loaded ACLs and those subjected to 100 cycles at 520N. Three of the ten samples in the 520N group failed before completing 100 cycles. The ruptured ACLs from these tests closely resembled adolescent ACL injuries in detachment patterns. ACL stiffness was also measured post-cyclical loading by applying force and pulling the ACL at a rate of 1 mm per sec. Moreover, ACL stiffness measurements decreased from 152.46 N/mm in the control group to 129.42 N/mm after 100 cycles at 300N and a more significant drop to 86.90 N/mm after 100 cycles at 520N. A one-way analysis of variance (ANOVA) and t-test were chosen for statistical analysis. CONCLUSIONS: The porcine stifle joint is an appropriate model for understanding ACL biomechanics in the skeletally immature demographic. The results emphasize the ligament's susceptibility to injury under high-impact loads pertinent to sports activities. The study advocates for further research into different loading scenarios and the protective role of muscle co-activation in ACL injury prevention.

Precision soft tissue balancing: grid-assisted pie-crusting in total knee arthroplasty.

Introduction: The varus and valgus knee deformities result from imbalance in tension between medial and lateral soft tissue compartments. These conditions need to be addressed during total knee arthroplasty (TKA). However, there is no consensus on optimal soft-tissue release techniques for correcting varus and valgus deformities during TKA. We assessed the efficacy of a novel grid-based pie-crusting technique on soft-tissue release. Methods: Cadaver knees were dissected, leaving only the femur and tibia connected by an isolated MCL or the femur and fibula connected by an isolated LCL. Bone cuts were made as performed during primary TKA. Mechanical testing was performed using an MTS machine. A 3D-printed 12-hole grid was placed directly over the MCL and LCL. Using an 18-gauge needle, horizontal in-out perforations were made 3 mm apart. Deformation and stiffness of the ligaments were collected after every 2 perforations. Means were calculated, and regression analyses were performed. Results: A total of 7 MCL and 6 LCL knees were included in our analysis. The mean medial femorotibial (MFT) space increased from 6.018 ± 1.4 mm-7.078 ± 1.414 mm (R2 = 0.937) following 12 perforations. The mean MCL stiffness decreased from 32.15 N/mm-26.57 N/mm (R2 = 0.965). For the LCL group, the mean gap between the femur and fibula increased from 4.287 mm-4.550 mm following 8 perforations. The mean LCL stiffness decreased from 29.955 N/mm-25.851 N/mm. LCL stiffness displayed a strong inverse relationship with the number of holes performed (R2 = 0.988). Discussion: Our results suggest that using this novel grid for pie-crusting of the MCL and LCL allows for gradual lengthening of the ligaments without sacrificing their structural integrity. Our proposed technique may serve as a valuable piece in the soft-tissue release toolkit for orthopaedic surgeons performing TKA in varus and valgus deformed knees.

Comparative study of locking neutralization plate construct versus tension band wiring with a cannulated screw for patella fractures: experimental and finite element analysis.

Transverse patella fractures, accounting for approximately 1% of Orthopedic injuries, pose intricate challenges due to their vital role in knee mechanics. This study aimed to compare the biomechanical performance of a construct, integrating cannulated screws and an anterior locking neutralization plate, with the conventional tension band wiring technique for treating these fractures. Experimental testing and Finite Element Analysis were employed to evaluate the constructs and gain profound insights into their mechanical behavior. Sixteen cadaveric knees were prepared, and transverse patella fractures were induced at the midpoints using a saw. The plate construct and tension band wire fixation were randomly assigned to the specimens. A cyclic test evaluated the implants' durability and stability, simulating knee movement during extension and flexion. Tensile testing assessed the implants' maximum failure force after cyclic testing, while Finite Element Analysis provided detailed insights into stress distribution and deformation patterns. Statistical analysis was exclusively performed for the experimental data. Results showed the plate enhanced stability with significantly lower deformation (0.09 ± 0.12 mm) compared to wire fixation (0.77 ± 0.54 mm) after 500 cycles (p = 0.004). In tensile testing, the construct also demonstrated higher failure resistance (1359 ± 21.53 N) than wire fixation (780.1 ± 22.62N) (p = 0.007). Finite Element Analysis highlighted distinct stress patterns, validating the construct's superiority. This research presents a promising treatment approach for transverse patella fractures with potential clinical impact and future research prospects. This study presents a promising advancement in addressing the intricate challenges of transverse patella fractures, with implications for refining clinical practice. The construct's improved stability and resistance to failure offer potential benefits in postoperative management and patient outcomes.

Association between Possibility of Purchasing Cigarettes and E-cigarette Experience among Korean Adolescent Smokers.

BACKGROUND: To aim of this study was to examine the association between perceived possibility of purchasing cigarettes and e-cigarette experience among adolescents who currently smoke cigarettes. METHODS: Data were derived from the Korea Youth Risk Behavior Web-Based Survey; a total of 29,169 current smokers participated. The dependent variable was e-cigarette experience in the previous month. Analyses included χ2 test and survey logistic regression. RESULTS: A perceived easy possibility of purchasing cigarettes increased the odds of e-cigarette experience (odds ratio, 1.19; 95% confidence interval, 1.07-1.33) compared to when it was perceived as impossible. An easy possibility of purchasing cigarettes increased the odds of e-cigarettes experience among males aged 12-15 or 17 years compared to when it was impossible to purchase cigarettes. CONCLUSION: A perceived easy possibility of purchasing cigarettes was more likely to increase e-cigarette experience among adolescents. Laws restricting adolescents' access to e-cigarettes must be strengthened.

Antioxidant activity of levan coated cerium oxide nanoparticles.

Levan coated cerium oxide nanoparticles (LCNPs) with the enhanced antioxidant activity were successfully synthesized and characterized. Levan and their derivatives are attractive for biomedical applications attributable to their antioxidant, anti-inflammation and anti-tumor properties. LCNPs were synthesized using the one-pot and green synthesis system with levan. For production of nanoparticles, levan plays a role as a stabilizing and reducing agent. Fourier transform infrared spectroscopy (FT-IR) analysis showed that LCNPs successfully synthesized. The morphology and size of nanoparticles were confirmed by transmission electron microscopy (TEM) and dynamic light scattering (DLS). LCNPs have good water solubility and stability. The conjugation of levan with cerium oxide nanoparticles improved antioxidant activity. Moreover the level of ROS was reduced after treatment of LCNPs to H2O2 stimulated NIH3T3 cells. These results demonstrate that the LCNPs are useful for applying of treatment of ROS induced diseases.

Self-assembled levan nanoparticles for targeted breast cancer imaging.

We report on the targeted imaging of breast cancer using self-assembled levan nanoparticles. Indocyanine green (ICG) was encapsulated in levan nanoparticles via self-assembly. Levan-ICG nanoparticles were found to be successfully accumulated in breast cancer via specific interaction between fructose moieties in levan and overexpressed glucose transporter 5 in breast cancer cells.

Transient inhibition of the ERK pathway prevents cerebellar developmental defects and improves long-term motor functions in murine models of neurofibromatosis type 1.

Individuals with neurofibromatosis type 1 (NF1) frequently exhibit cognitive and motor impairments and characteristics of autism. The cerebellum plays a critical role in motor control, cognition, and social interaction, suggesting that cerebellar defects likely contribute to NF1-associated neurodevelopmental disorders. Here we show that Nf1 inactivation during early, but not late stages of cerebellar development, disrupts neuronal lamination, which is partially caused by overproduction of glia and subsequent disruption of the Bergmann glia (BG) scaffold. Specific Nf1 inactivation in glutamatergic neuronal precursors causes premature differentiation of granule cell (GC) precursors and ectopic production of unipolar brush cells (UBCs), indirectly disrupting neuronal migration. Transient MEK inhibition during a neonatal window prevents cerebellar developmental defects and improves long-term motor performance of Nf1-deficient mice. This study reveals essential roles of Nf1 in GC/UBC migration by generating correct numbers of glia and controlling GC/UBC fate-specification/differentiation, identifying a therapeutic prevention strategy for multiple NF1-associcated developmental abnormalities.

Gender differences in marital disruption among patients with cancer: results from the Korean National Health and Nutrition Examination Survey (KNHANES).

BACKGROUND: Cancer is a major life event that imposes huge economic and mental burdens on patients and families. In addition, the diagnosis of cancer also causes significant family discordance that can lead to marital problems such as divorce or separation. The aim of this study was to investigate the association and any related gender differences between cancer diagnosis and marital disruption among cancer survivors. MATERIALS AND METHODS: We used the recent cross-sectional Korea National Health and Nutrition Examination Survey (4th and 5th; Years 2008-2012). The study participants were 623 married cancer survivors over the age of 19. A multivariate logistic regression analysis was conducted to estimate odds ratios. RESULTS: After adjusting for socioeconomic status and health-related behaviors, the odds ratio of marital disruption among female cancer survivors compared with male cancer survivors was 3.94 (95%CI 1.30-11.94; p=0.02). The odds ratio of marital disruption for the below-average economic level compared with the above-average economic level was 5.64 (95%CI: 1.03-31.02; p=0.05). When compared with the non-smoking cancer survivors, the smoking cancer survivors had an OR of marital disruption equal to 2.94 (95%CI: 1.08-8.00; p=0.03). CONCLUSIONS: The findings of this study suggest that the odds of marital disruption among female cancer survivors are higher than those among their male counterparts. Medical practitioners should be sensitive to early signs of marital discord in couples affected by a cancer diagnosis. Early identification and psychosocial intervention might reduce the frequency of divorce and separation and thus improve quality of life and quality of care for cancer survivors.

Indocyanine green encapsulated nanogels for hyaluronidase activatable and selective near infrared imaging of tumors and lymph nodes.

Indocyanine green (ICG) encapsulated hyaluronic acid (HA) nanogels were first studied for highly selective detection of specific cancers and lymph nodes via hyaluronidase sensitive switch-on of near infrared fluorescence as a long-lasting and stimuli-responsive imaging probe.

SAG/RBX2/ROC2 E3 ubiquitin ligase is essential for vascular and neural development by targeting NF1 for degradation.

SAG/RBX2/ROC2 protein is an essential RING component of SCF E3 ubiquitin ligase. The role of SAG during embryogenesis remains unknown. We report a critical role for SAG in controlling vascular and neural development by modulating RAS activity via promoting degradation of neurofibromatosis type 1 (NF1). Mice mutant for Sag died at embryonic day 11.5-12.5 with severe abnormalities in vascular and nervous system. Sag inactivation caused Nf1 accumulation and Ras inhibition, which blocks embryonic stem (ES) cells from undergoing endothelial differentiation and inhibits angiogenesis and proliferation in teratomas. Simultaneous Nf1 deletion fully rescues the differentiation defects in Sag(-/-) ES cells and partially rescues vascular and neural defects in Sag(-/-) embryos, suggesting that the effects of Sag deletion may not be solely explained by Nf1 misregulation. Collectively, our study identifies NF1 as a physiological substrate of SAG-CUL1-FBXW7 E3 ligase and establishes a ubiquitin-dependent regulatory mechanism for the NF1-RAS pathway during embryogenesis.

Gene delivery system based on highly specific recognition of surface-vimentin with N-acetylglucosamine immobilized polyethylenimine.

Gene and drug-delivery systems that use immobilization of carbohydrates are useful for the specific targeting of lectin-expressing tissues. Here, we report that N-acetylglucosamine (GlcNAc) with polyethylenimine (GlcNAc-PEI) specifically interacted with vimentin-expressing cells such as 293FT and HeLa cells. Recently, the intermediate filaments vimentin and desmin have been reported to have GlcNAc-binding lectin-like properties on the cell surface. Therefore, GlcNAc-conjugated agents can be targeted to vimentin- and desmin-expressing cells and tissues. Vimentin-expressing 293FT and HeLa cells were efficiently transfected with green fluorescent protein and luciferase genes by using GlcNAc-PEI; the expression of these genes in vimentin-knockdown cells were low. Confocal microscopic analysis showed that GlcNAc-PEI complexes interacted with vimentin on the cell surface of HeLa cells. These results demonstrate that GlcNAc-PEI/DNA complexes were specifically taken up by 293FT and HeLa cells via vimentin. We suggest that this gene-delivery system could be used to target various vimentin-expressing cells such as fibroblasts and tumor cells.

Design of selective gas sensors using additive-loaded In2O3 hollow spheres prepared by combinatorial hydrothermal reactions.

A combinatorial hydrothermal reaction has been used to prepare pure and additive (Sb, Cu, Nb, Pd, and Ni)-loaded In2O3 hollow spheres for gas sensor applications. The operation of Pd- and Cu-loaded In2O3 sensors at 371 °C leads to selective H2S detection. Selective detection of CO and NH3 was achieved by the Ni-In2O3 sensor at sensing temperatures of 371 and 440 °C, respectively. The gas responses of six different sensors to NH3, H2S, H2, CO and CH4 produced unique gas sensing patterns that can be used for the artificial recognition of these gases.

Amnibacterium kyonggiense gen. nov., sp. nov., a new member of the family Microbacteriaceae.

A Gram-positive, non-motile bacterium, designated KSL51201-037(T), was isolated from Anyang stream, Republic of Korea, and was characterized using a polyphasic taxonomic approach. Comparative 16S rRNA gene sequence analysis showed that strain KSL51201-037(T) belonged to the family Microbacteriaceae of the class Actinobacteria and exhibited 96.9 % gene sequence similarity to Labedella gwakjiensis KSW2-17(T), 96.0 % to Leifsonia ginsengi wged11(T) and 95.9 % to Microterricola viridarii KV-677(T). The G+C content of the genomic DNA was 72.7 mol%. Strain KSL51201-037(T) had l-2,4-diaminobutyric acid as the diagnostic cell-wall diamino acid, MK-11 and MK-12 as the major menaquinones, anteiso-C(15 : 0) (47.8 %) and iso-C(16 : 0) (24.0 %) as the major fatty acids and phosphatidylglycerol and three unknown phospholipids as the major polar lipids. On the basis of phenotypic and genotypic properties and phylogenetic distinctiveness, it is suggested that strain KSL51201-037(T) represents a novel species of a new genus in the family Microbacteriaceae for which the name Amnibacterium kyonggiense gen. nov., sp. nov. is proposed. The type strain of the type species is KSL51201-037(T) (=KEMC 51201-037(T)=JCM 16463(T)).

Selective regulation of autoreactive B cells by FcgammaRIIB.

FcgammaRIIB is an inhibitory receptor which plays a role in limiting B cell and DC activation. Since FcgammaRIIB is known to dampen the signaling strength of the BCR, we wished to determine the impact of FcgammaRIIB on the regulation of BCRs which differ in their affinity for DNA. For these studies, FcgammaRIIB deficient BALB/c mice were bred with mice expressing the transgene-encoded H chain of the R4A anti-DNA antibody which gives rise to BCRs which express high, low or no affinity for DNA. The deletion of FcgammaRIIB in R4A BALB/c mice led to an alteration in the B cell repertoire, allowing for the expansion and activation of high affinity DNA-reactive B cells. By 6-8 months of age, R4A x FcgammaRIIB-/- BALB/c mice spontaneously developed anti-DNA antibody titers. These mice also displayed an induction of IFN-inducible genes and an elevation in levels of the B cell survival factor, BAFF. These data demonstrate that FcgammaRIIB preferentially limits activation of high affinity autoreactive B cells and can influence the activation of DC through an immune complex-mediated mechanism.

Surface modification of polydimethylsiloxane (PDMS) induced proliferation and neural-like cells differentiation of umbilical cord blood-derived mesenchymal stem cells.

Stem cell-based therapy has recently emerged for use in novel therapeutics for incurable diseases. For successful recovery from neurologic diseases, the most pivotal factor is differentiation and directed neuronal cell growth. In this study, we fabricated three different widths of a micro-pattern on polydimethylsiloxane (PDMS; 1, 2, and 4 microm). Surface modification of the PDMS was investigated for its capacity to manage proliferation and differentiation of neural-like cells from umbilical cord blood-derived mesenchymal stem cells (UCB-MSCs). Among the micro-patterned PDMS fabrications, the 1 microm-patterned PDMS significantly increased cell proliferation and most of the cells differentiated into neuronal cells. In addition, the 1 microm-patterned PDMS induced an increase in cytosolic calcium, while the differentiated cells on the flat and 4 microm-patterned PDMS had no response. PDMS with a 1 microm pattern was also aligned to direct orientation within 10 degrees angles. Taken together, micro-patterned PDMS supported UCB-MSC proliferation and induced neural like-cell differentiation. Our data suggest that micro-patterned PDMS might be a guiding method for stem cell therapy that would improve its therapeutic action in neurological diseases.

Cytotoxic and antitumor activity of momilactone B from rice hulls.

The cytotoxic and antitumor activity of methanolic extract of rice hulls (MERH) were evaluated by the MTT-dye reduction assay against human colon cancer cells and the colonic aberrant crypt foci (ACF) assay in 1,2-dimethylhydrazine (DMH)-injected F344 male rats, respectively. MERH was found to be highly cytotoxic, with IC50 values of 0.5 microg/mL in vitro. Forty weeks of MERH supplementation (50 mg/kg of body weight/day) reduced colonic pre-neoplastic ACF formation by 35% (p < 0.01). An active compound, momilactone B, was isolated from MERH by silica gel chromatography, Sephadex LH-20 chromatography, and HPLC. The cytotoxic activity of momilactone B was evaluated by the MTT-dye reduction, lactate dehydrogenase (LDH), and colony-forming ability assays in human colon cancer HT-29 and SW620 cells. The results indicated that momilactone B from rice hulls might be a new candidate for chemotherapeutic agent against human colon cancer.

Reversal of the TPA-induced inhibition of gap junctional intercellular communication by Chaga mushroom (Inonotus obliquus) extracts: effects on MAP kinases.

Chaga mushroom (Inonotus obliquus) has continued to receive attention as a folk medicine with indications for the treatment of cancers and digestive diseases. The anticarcinogenic effect of Chaga mushroom extract was investigated using a model system of gap junctional intercellular communication (GJIC) in WB-F344 normal rat liver epithelial cells. The cells were pre-incubated with Chaga mushroom extracts (5, 10, 20 microg/ml) for 24 h and this was followed by co-treatment with Chaga mushroom extracts and TPA (12-O-tetradecanoylphorbol-13-acetate, 10 ng/ml) for 1 h. The inhibition of GJIC by TPA (12-O-tetradecanoylphorbol-13-acetate), promoter of cancer, was prevented with treatment of Chaga mushroom extracts. Similarly, the increased phosphorylated ERK1/2 and p38 protein kinases were markedly reduced in Chaga mushroom extracts-treated cells. There was no change in the JNK kinase protein level, suggesting that Chaga mushroom extracts could only block the activation of ERK1/2 and p38 MAP kinase. The Chaga mushroom extracts further prevented the inhibition of GJIC through the blocking of Cx43 phosphorylation. Indeed cell-to-cell communication through gap junctional channels is a critical factor in the life and death balance of cells because GJIC has an important function in maintaining tissue homeostasis through the regulation of cell growth, differentiation, apoptosis and adaptive functions of differentiated cells. Thus Chaga mushroom may act as a natural anticancer product by preventing the inhibition of GJIC through the inactivation of ERK1/2 and p38 MAP kinase.

NPC1 gene deficiency leads to lack of neural stem cell self-renewal and abnormal differentiation through activation of p38 mitogen-activated protein kinase signaling.

Neural stem cells (NSCs) are capable of giving rise to neurons, glia, and astrocytes. Although self-renewal and differentiation in NSCs are regulated by many genes, such as Notch and Numb, little is known about the role of defective genes on the self-renewal and differentiation of NSCs from developing brain. The Niemann-Pick type C1 (NPC1) disease is a neurodegenerative disease caused by a mutation of the NPC1 gene that affects the function of the NPC1 protein. The ability of NSC self-renewal and differentiation was investigated using a model of NPC1 disease. The NPC1 disorder significantly affected the self-renewal ability of NSCs, as well as the differentiation. NSCs from NPC1-/- mice showed impaired self-renewal ability compared with the NPC1+/+ mice. These alterations were accompanied by the enhanced activity of p38 mitogen-activated protein kinases (MAPKs). Further, the specific p38 MAPK inhibitor SB202190 improved the self-renewal ability of NSCs from NPC-/- mice. This indicated that the NPC1 deficiency can lead to lack of self-renewal and altered differentiation of NSCs mediated by the activation of p38 MAPK, impairing the generation of neurospheres from NPC1-/- Thus, the NPC1 gene may play a crucial role in NSC self-renewal associated with p38 MAPK.

Chinese cabbage extracts and sulforaphane can protect H2O2-induced inhibition of gap junctional intercellular communication through the inactivation of ERK1/2 and p38 MAP kinases.

The cruciferous vegetables such as Chinese cabbages and broccoli are known to have anticancer phytochemicals, and the consumption of cruciferous vegetables has been proposed to protect against various cancers. The anticarcinogenic properties of some Chinese cabbage extracts and sulforaphane glucosinolate (SFN) were assessed by examining their ability to prevent the inhibition of gap junctional intercellular communication (GJIC) induced by hydrogen peroxide (H2O2) in WB-F344 normal rat liver epithelial cells. The cells were preincubated with Chinese cabbage extracts and SFN for 24 h followed by cotreatment with cells and H2O2 (750 microM) for 1 h. Chinese cabbage extracts and SFN prevented the inhibition of GJIC and phosphorylation of gap junction protein connexin43 (Cx43) by H2O2 treatment. Chinese cabbage extracts and SFN were able to prevent the inhibition of GJIC through the blocking of Cx43 phosphorylaton and inactivation of ERK 1/2 and p38 MAP kinase. The results suggest that cruciferous vegetables and their components, SFN, may exert the anticancer effect by targeting the GJIC as a functional dietary chemopreventive agent.

The role of IgM antibodies in the recognition and clearance of apoptotic cells.

Apoptotic cells not only translocate phosphatidylserine to the outside of the membrane, they activate phospholipases that remodel their membranes resulting in the exposure and diffusion of altered phospholipids. These altered phospholipids include lysophosphotidylcholine (LPC) that is a ligand for CRP and is also antigenic for natural IgM antibodies. Furthermore, soluble LPC acts as a "find me" signal to attract phagocytes to migrate toward apoptotic cells. IgM mediated opsonization of apoptotic cells with complement accelerates their clearance by phagocytic cells. Failure to rapidly remove apoptotic cells on the other hand, allows dying cells to undergo post-apoptotic necrosis and inflammation. Natural antibodies therefore provide a previously unrecognized role in prevention of autoimmunity.