Comparison of the predictive values of MRI-based vertebral bone quality scores for the determination of osteoporosis in different diseases.

PURPOSE: The study aimed to examine the consistency of vertebral bone quality (VBQ) scores for assessing osteoporosis across different etiologies and explore the predictive value of various VBQ scores for fragility vertebral fractures. METHODS: Patients with fragility fractures were matched by age and sex to patients with lumbar degeneration. VBQ scores were calculated in T1- and T2-weighted magnetic resonance imaging. Differential analysis of bone quality was performed based on etiology. RESULTS: A total of 96 inpatients were retrospectively enrolled. VBQT1 scores were only sensitive to osteoporotic bone in degenerative group (p < 0.01), failing to identify osteoporosis in fractured group (p > 0.05). For the degenerative group, the area under the curve (AUC) using the VBQT1 scores to differentiate osteoporosis was 0.72. After controlling the confounding variables, only VBQT2 scores were significantly higher in fractured group than degenerative group, with a greater AUC of 0.82 predicting fragility fractures. VBQT1 scores moderately correlated with femoral neck T-scores in degenerative group (r = -0.45, p < 0.01) but not in fractured group (r = -0.24, p > 0.05). VBQT2 scores were not associated with femoral neck T-scores (p > 0.05). CONCLUSION: This study is the first to evaluate the effectiveness of VBQs scores in assessing osteoporosis post-fracture. Only non-fractured patients' bone quality is fully susceptible to VBQT1 scores. While VBQT1 scores may not correlate with fragility fractures, VBQT2 scores present a viable alternative.

VTSNN: a virtual temporal spiking neural network.

Spiking neural networks (SNNs) have recently demonstrated outstanding performance in a variety of high-level tasks, such as image classification. However, advancements in the field of low-level assignments, such as image reconstruction, are rare. This may be due to the lack of promising image encoding techniques and corresponding neuromorphic devices designed specifically for SNN-based low-level vision problems. This paper begins by proposing a simple yet effective undistorted weighted-encoding-decoding technique, which primarily consists of an Undistorted Weighted-Encoding (UWE) and an Undistorted Weighted-Decoding (UWD). The former aims to convert a gray image into spike sequences for effective SNN learning, while the latter converts spike sequences back into images. Then, we design a new SNN training strategy, known as Independent-Temporal Backpropagation (ITBP) to avoid complex loss propagation in spatial and temporal dimensions, and experiments show that ITBP is superior to Spatio-Temporal Backpropagation (STBP). Finally, a so-called Virtual Temporal SNN (VTSNN) is formulated by incorporating the above-mentioned approaches into U-net network architecture, fully utilizing the potent multiscale representation capability. Experimental results on several commonly used datasets such as MNIST, F-MNIST, and CIFAR10 demonstrate that the proposed method produces competitive noise-removal performance extremely which is superior to the existing work. Compared to ANN with the same architecture, VTSNN has a greater chance of achieving superiority while consuming ~1/274 of the energy. Specifically, using the given encoding-decoding strategy, a simple neuromorphic circuit could be easily constructed to maximize this low-carbon strategy.

Does the sizing of current cervical disc arthroplasty systems match Chinese cervical anatomic dimensions?

Objective: The objectives of this study were to analyze the computed tomography (CT) scan imaging data of the cervical spine from healthy volunteers and to correlate the measurements to the dimensions of current cervical disc arthroplasty systems. Methods: A total of 130 participants (78 males and 52 females) with a mean age of 41.0 years (range 18.0-66.0 years) who had undergone computed tomography scans of the cervical spine were included. The linear parameters of the C3 to C7 levels, including anterior-posterior diameter (AP), middle disc height (DH), anterior disc height (ADH), posterior disc height (PDH) and center mediolateral diameter (ML), were measured. The analysis was conducted comparing different cervical levels, sexes, and age groups. Known dimensions from eight cervical disc arthroplasty systems were compared with the morphologic data. Results: A total of 520 vertebral segments were measured. The mean values for the measured parameters were as follows: anterior-posterior diameter 16.08 ± 1.84 mm, mediolateral diameter 16.13 ± 1.99 mm, anterior disc height 3.88 ± 1.11 mm, disc height 5.73 ± 1.00 mm, posterior disc height 2.83 ± 0.94 mm, and mediolateral diameter/anterior-posterior diameter 1.01 ± 0.13. All parameters except for posterior disc height were significantly different across the different cervical levels (p < 0.05). There were also significant sex differences in terms of the linear parameters. No differences were found in the majority of parameters among the different age groups (p > 0.05), except for anterior-posterior diameter at the C6/7 level. A comparison of the bone dimensions from the study data and the dimensions of the implants indicated the presence of a size mismatch in the currently available cervical disc prostheses. Conclusion: There is a large discrepancy between the cervical anatomical data of Chinese patients and the sizes of currently available prostheses. The dimensions collected in this study could be used to design and develop appropriate disc prostheses for Chinese patients.

Ideal entry point and trajectory for C2 pedicle screw placement in children: a 3D computed tomography study.

PURPOSE: To identify the ideal entry point for pediatric C2 pedicle screw and to obtain parameters of it for the indication of pediatric atlantoaxial fusion arthrodesis. METHODS: The pediatric cervical CT images were reconstructed into the 3D digital models and the C2 vertebrae were separated. The location of ideal entry point and screw placement related linear and angular parameters were assessed on the 3D digital models. RESULTS: A total of 214 pedicles from 107 C2 digital models were analyzed. The average entry point for C2 was 3.80 ± 2.78 mm medial to the lateral notch (LN) and 2.57 ± 1.70 mm superior to the LN. The average pedicle diameter (PD) was 6.02 ± 1.31 mm, and the average pedicle screw length (PSL) was 25.63 ± 3.46 mm. Statistical differences were found between different sex for PD and PSL (P < 0.05). As patient age increases, using the most lateral and inferior edge of the lateral mass as a reference marker, the entry point tends to move medial and cephalad, when using the LN as a reference marker, the entry point tends to move medial and slightly caudad. Univariate linear regression analysis suggested that these linear parameters were associated with age (P < 0.01). CONCLUSION: In this study, we found that the measurement results of C2 pedicle screw varied based on sex, laterality, and ages for children younger than 18 years. The entry point of the screws facilitating ideal trajectory tends to change in a linear way as a function of age. This information helps the surgeon to establish the specific anatomy related to C2 pedicle screw placement to facilitate fixation in the pediatric patients.

Proteomic Analysis Reveals the Vital Role of Synaptic Plasticity in the Pathogenesis of Temporal Lobe Epilepsy.

Temporal lobe epilepsy (TLE) is a chronic neurological disorder that is often resistant to antiepileptic drugs. The pathogenesis of TLE is extremely complicated and remains elusive. Understanding the molecular mechanisms underlying TLE is crucial for its diagnosis and treatment. In the present study, a lithium-pilocarpine-induced TLE model was employed to reveal the pathological changes of hippocampus in rats. Hippocampal samples were taken for proteomic analysis at 2 weeks after the onset of spontaneous seizure (a chronic stage of epileptogenesis). Isobaric tag for relative and absolute quantization (iTRAQ) coupled with liquid chromatography-tandem mass spectrometry (LC-MS/MS) technique was applied for proteomic analysis of hippocampus. A total of 4173 proteins were identified from the hippocampi of epileptic rats and its control, of which 27 differentially expressed proteins (DEPs) were obtained with a fold change > 1.5 and P < 0.05. Bioinformatics analysis indicated 27 DEPs were mainly enriched in "regulation of synaptic plasticity and structure" and "calmodulin-dependent protein kinase activity," which implicate synaptic remodeling may play a vital role in the pathogenesis of TLE. Consequently, the synaptic plasticity-related proteins and synaptic structure were investigated to verify it. It has been demonstrated that CaMKII-α, CaMKII-ß, and GFAP were significant upregulated coincidently with proteomic analysis in the hippocampus of TLE rats. Moreover, the increased dendritic spines and hippocampal sclerosis further proved that synaptic plasticity involves in the development of TLE. The present study may help to understand the molecular mechanisms underlying epileptogenesis and provide a basis for further studies on synaptic plasticity in TLE.

Population pharmacokinetics and dosing optimization of mezlocillin in neonates and young infants.

OBJECTIVES: Mezlocillin is used in the treatment of neonatal infectious diseases. However, due to the absence of population pharmacokinetic studies in neonates and young infants, dosing regimens differ considerably in clinical practice. Hence, this study aimed to describe the pharmacokinetic characteristics of mezlocillin in neonates and young infants, and propose the optimal dosing regimen based on the population pharmacokinetic model of mezlocillin. METHODS: A prospective, open-label pharmacokinetic study of mezlocillin was carried out in newborns. Blood samples were collected using an opportunistic sampling method. HPLC was used to measure the plasma drug concentrations. A population pharmacokinetic model was developed using NONMEM software. RESULTS: Ninety-five blood samples from 48 neonates and young infants were included. The ranges of postmenstrual age and birth weight were 29-40 weeks and 1200-4000 g, respectively, including term and preterm infants. A two-compartment model with first-order elimination was developed to describe the population pharmacokinetics of mezlocillin. Postmenstrual age, current weight and serum creatinine concentration were the most important covariates. Monte Carlo simulation results indicated that the current dose of 50 mg/kg q12h resulted in 89.2% of patients achieving the therapeutic target, when the MIC of 4 mg/L was used as the breakpoint. When increasing the dosing frequency to q8h, a dose of 20 mg/kg resulted in 74.3% of patients achieving the therapeutic target. CONCLUSIONS: A population pharmacokinetic model of mezlocillin in neonates and young infants was established. Optimal dosing regimens based on this model were provided for use in neonatal infections.

Baicalein improves cognitive deficits and hippocampus impairments in temporal lobe epilepsy rats.

Temporal lobe epilepsy (TLE) is a chronic neurological disorder that is a refractory disease. Baicalein possesses various pharmacological activities, including neuroprotection in neurodegenerative disease. However, whether baicalein is protective in the treatment of TLE is not determined. Therefore, the present study investigated the role of baicalein in the treatment of TLE. Baicalein was injected intraperitoneally to TLE rats for two weeks after the onset of spontaneous recurrent seizures (SRS). Rats were observed for the occurrence of SRS, and cognitive and hippocampus injuries were evaluated. Oxidative stress and inflammatory cytokines were measured. Corticosterone and its receptor, actin-associated protein F-actin and cofilin-1 were investigated in the brains of epileptic rats. Baicalein significantly improved cognition and reduced hippocampus damage and mossy fibre sprouting in TLE rats without obvious SRS suppression. Baicalein produced excellent anti-oxidative and anti-inflammatory effects in TLE rats. Baicalein restored the disruption of the glucocorticoid signal pathway and actin-associated protein in TLE rats. These results suggest that the neuroprotective effects of baicalein on cognition and the hippocampus are associated with the suppression of oxidative stress and inflammation and the regulation of the glucocorticoid pathway and actin-associated protein in TLE rats. This evidence supports the use of baicalein as an adjuvant agent for epilepsy treatment.