Recent progress and outlooks in rhodamine-based fluorescent probes for detection and imaging of reactive oxygen, nitrogen, and sulfur species.

Reactive oxygen species (ROS), reactive nitrogen species (RNS), and reactive sulfur species (RSS) serve as vital mediators essential for preserving intracellular redox homeostasis within the human body, thereby possessing significant implications across physiological and pathological domains. Nevertheless, deviations from normal levels of ROS, RNS, and RSS disturb redox homeostasis, leading to detrimental consequences that compromise bodily integrity. This disruption is closely linked to the onset of various human diseases, thereby posing a substantial threat to human health and survival. Small-molecule fluorescent probes exhibit considerable potential as analytical instruments for the monitoring of ROS, RNS, and RSS due to their exceptional sensitivity and selectivity, operational simplicity, non-invasiveness, localization capabilities, and ability to facilitate in situ optical signal generation for real-time dynamic analyte monitoring. Due to their distinctive transition from their spirocyclic form (non-fluorescent) to their ring-opened form (fluorescent), along with their exceptional light stability, broad wavelength range, high fluorescence quantum yield, and high extinction coefficient, rhodamine fluorophores have been extensively employed in the development of fluorescent probes. This review primarily concentrates on the investigation of fluorescent probes utilizing rhodamine dyes for ROS, RNS, and RSS detection from the perspective of different response groups since 2016. The scope of this review encompasses the design of probe structures, elucidation of response mechanisms, and exploration of biological applications.

Computer-assisted virtual preoperative planning in orthopedic surgery for acetabular fractures based on actual computed tomography data.

Acetabular fractures have always been very challenging for orthopedic surgeons; therefore, appropriate preoperative evaluation and planning are particularly important. This study aimed to explore the application methods and clinical value of preoperative computer simulation (PCS) in treating pelvic and acetabular fractures. Spiral computed tomography (CT) was performed on 13 patients with pelvic and acetabular fractures, and Digital Imaging and Communications in Medicine (DICOM) data were then input into Mimics software to reconstruct three-dimensional (3D) models of actual pelvic and acetabular fractures for preoperative simulative reduction and fixation, and to simulate each surgical procedure. The times needed for virtual surgical modeling and reduction and fixation were also recorded. The average fracture-modeling time was 45 min (30-70 min), and the average time for bone reduction and fixation was 28 min (16-45 min). Among the surgical approaches planned for these 13 patients, 12 were finally adopted; 12 cases used the simulated surgical fixation, and only 1 case used a partial planned fixation method. PCS can provide accurate surgical plans and data support for actual surgeries.

[Effects of Swan-like Shape Memory Connector on stress shielding rate and callus development during experimental fracture healing process].

OBJECTIVE: To investigate the stress shielding rate, ultrastructural and biomechanical property of the healing bone fixed by Swan-like Shape Memory Connector (SMC) during experimental fracture healing in rabbits. METHODS: Unilateral osteotomy of left humeral diaphysis was performed in 140 adult New Zealand rabbits. The humeral fracture was fixed with SMC in study group and 4-hole dynamic compression plate (DCP) in control group. The animals were sacrificed at the 2nd, 4th, 8th, 12th, and 16th weeks postoperatively. The humeral shafts were harvested for three-point bending tests and stress shielding rate examination. Samples from the fracture gaps were observed with scanning electron microscope. RESULTS: Within an observation period of 12 weeks after operation, the stress shielding rates were significantly lower in study group than those in control group, and the bending strength and the bending rigidity were statistically higher. It was also found that collagen fibers in callus was arranged more regulate and early mineral deposition in study group. CONCLUSION: These results suggest that SMC contributes to the proliferation and differentiation of osteoblasts, promoting the formation and calcification of bone matrix and enhancing biomechanical property of the healing bone, which might be closely correlated with a less stress shielding effect produced by SMC.

[Effects of soybean isoflavones on expression levels of osteoprotegerin and osteoprotegerin ligand mRNAs in bone tissues of ovariectomized rats].

OBJECTIVE: To investigate the effects of soybean isoflavones (SI) on expression levels of osteoprotegerin (OPG) and osteoprotegerin ligand (OPGL) mRNAs in bone tissues of ovariectomized rats, and to discuss the mechanism of soybean isoflavaones in preventing and treating postmenopausal osteoporosis (PMO). METHODS: Thirty adult SD rats were randomly divided into 3 groups: sham-operation group, untreated group and SI-treated group. The rats in the last two groups were bilaterally ovariectomized. The bone density of L(3) to L(6) vertebrae was detected after 12-week intervention. Total RNA was extracted from femur head and the expression levels of OPG and OPGL mRNAs were examined by real-time quantitative polymerase chain reaction. RESULTS: SI could increase the bone density of lumbar vertebrae in ovariectomized rats, up-regulate the expression level of OPG mRNA and down-regulate the ratio of OPGL mRNA/OPG mRNA, but exert no significant effect on the expression of OPGL mRNA. CONCLUSION: The therapeutic effects of SI on PMO may be related to regulating the expression levels of OPG and OPGL mRNAs, and the ratio of OPGL mRNA/OPG mRNA.