Significance of mechanical loading in bone fracture healing, bone regeneration, and vascularization

In 1892, J.L. Wolff proposed that bone could respond to mechanical and biophysical stimuli as a dynamic organ. This theory presents a unique opportunity for investigations on bone and its potential to aid in tissue repair. Routine activities such as exercise or machinery application can exert mechanical loads on bone. Previous research has demonstrated that mechanical loading can affect the differentiation and development of mesenchymal tissue. However, the extent to which mechanical stimulation can help repair or generate bone tissue and the related mechanisms remain unclear. Four key cell types in bone tissue, including osteoblasts, osteoclasts, bone lining cells, and osteocytes, play critical roles in responding to mechanical stimuli, while other cell lineages such as myocytes, platelets, fibroblasts, endothelial cells, and chondrocytes also exhibit mechanosensitivity. Mechanical loading can regulate the biological functions of bone tissue through the mechanosensor of bone cells intraosseously, making it a potential target for fracture healing and bone regeneration. This review aims to clarify these issues and explain bone remodeling, structure dynamics, and mechano-transduction processes in response to mechanical loading. Loading of different magnitudes, frequencies, and types, such as dynamic versus static loads, are analyzed to determine the effects of mechanical stimulation on bone tissue structure and cellular function. Finally, the importance of vascularization in nutrient supply for bone healing and regeneration was further discussed.

Evaluation Effect of Aspiration of 0.2 ml of Cerebrospinal Fluid After Completion of Injection 0.5% Bupivacaine and Reinjection Into Subarachnoid Space on Sensory and Motor Block in Cesarean Section: A Randomized Clinical Trial

Background

Spinal anesthesia (SPA) is the most common type of anesthesia administered for cesarean section. The main aim of this study was to evaluate the effect of aspiration of CSF (0.2 mL) immediately after SPA with hyperbaric 0.5% bupivacaine on the extent of sensory and motor block.

Methods

In this clinical trial, 60 women at ≥37 weeks of gestation and aged between 18 and 46 years, candidate for cesarean delivery under spinal anesthesia were randomly allocated into two equal groups (n = 30). Group A (CSF-aspiration group) received the spinal anesthesia with 10 mg of hyperbaric 0.5% bupivacaine with aspiration of 0.2 ml of CSF. Group B (no-CSF-aspiration group) received only 10 mg of 0.5% hyperbaric bupivacaine. Pin-prick analgesia and motor block were tested during the induction.

Results

The mean maximum level of analgesia was T6 in each group. Although the mean time to reach the maximum level of anesthesia (4.43 ± 5.14 vs. 2.76 ± 2.04, P = 0.107) and to reach T10 level (50.56 ± 11.51 vs. 49.10 ± 13.68, P = 0.665) in the CSF-aspiration group is longer than the non-CSF-aspiration group, but this differences were not significant. There were no significant between-group differences regarding sensory and motor block quality (P = 0.389) or failed SPA (four cases in CSF-aspiration group vs. two cases in no-CSF-aspiration group, P = 0.389). The incidence of bradycardia, hypotension, headache, vomiting and nausea were similar in both groups (P > 0.05). In addition, the difference in hemodynamic parameters between the two groups over times was not statistically significant.

Conclusion

Our finding indicated that the aspiration of 0.2 ml of CSF after injection of spinal anesthesia with hyperbaric 0.5% bupivacaine does not seem to affect the extent of sensory and motor block, success rate, or outcome after SPA in cesarean section.

Clinical Trial Registration

[https://www.irct.ir/search/result?query=IRCT20120915010841N25], identifier [IRCT20120915010841N25].

Fe3O4@PDA@PANI core-shell nanocomposites as a new adsorbent for simultaneous preconcentration of Tartrazine and Sunset Yellow by ultrasonic-assisted dispersive micro solid-phase extraction

In this research, novel magnetic Fe₃O₄@PDA@PANI core-shell nanoparticles were designed and fabricated as an efficient adsorbent in the service of ultrasound-assisted dispersive micro-solid phase extraction for simultaneous preconcentration of Sunset Yellow (SY) and Tartrazine (Tar) before UV-Vis spectrophotometric detection. This adsorbent was fully characterized by Fourier Transform Infrared (FT-IR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), and Energy Dispersive X-ray (EDX) analysis. To overcome the spectral overlapping of SY and Tar dyes, the derivative spectrophotometric method was successfully used for the simultaneous detection of dyes in their binary solutions. The operating parameters affecting preconcentration efficiency and spectrophotometric determination were optimized. Under optimal conditions, the limit of detections (LOD) was obtained 0.2 and 0.5 ng mL^-1 for SY and Tar, respectively. The adsorption capacity and reusability of core-shell nanoparticles were significant. The satisfactory results of analysis of a few real samples indicate that the method is very favored in the analysis of various complex matrices.

The quality of life of the patients with diabetes type 2 using EQ-5D-5 L in Birjand

BACKGROUND

Due to high prevalence of diabetes and its complications, evaluating of the patients' quality of life is critical. EQ-5D-5 L is a valid tool for assessing the quality of life in chronic diseases including diabetes. The present study conducted to illustrate the quality of life for the patients who referred to the Diabetes clinic and determine its relationship with their demographic and clinical characteristics in Birjand in 2017.

METHODS

In this cross-sectional study, 300 patients with type 2 diabetes were selected through a systematic sampling in 2017. Data were collected using a checklist including patients' demographic, clinical and laboratory information and the EQ-5D-5 L. Data were entered the SPSS (22) software, analyzed by independent sample T-test, ANOVA, Chi-Square and logistic regression tests. Statistical significance was inferred at α = 0.05.

RESULTS

Mean age for the participants was 58.1 ± 9.6 years. The mean score for the quality of life based on the EQ-5D-5 L and VAS scale were 0.89 ± 0.13 and 65.22 ± 9.32, respectively. Moderate and severe problems were found in the anxiety/depression dimensions in 12% of the patients, while these numbers for the presence of pain/discomfort and mobility were slightly higher (13.7 and 13.6%, respectively). The mean scores for quality of life and VAS were significantly higher in the men, employed and patients < 50 years age.

CONCLUSION

The quality of life for the type 2 diabetes patients is affected by numerous factors including sex, occupation, duration of the disease and the presence of complications such as neuropathy and nephropathy.