[Accuracy and efficiency of 2D/3D single-vertebra spine navigation registration method based on dual-view feature fusion].

Objective: To investigate the accuracy and efficiency of spine 2D/3D preoperative CT and intraoperative X-ray registration through a framework for spine 2D/3D single-vertebra navigation registration based on the fusion of dual-position image features. Methods: The preoperative CT and intraoperative anteroposterior (AP) and lateral (LAT) X-ray images of 140 lumbar spine patients who visited Huashan Hospital Affiliated to Fudan University from January 2020 to December 2023 were selected. In order to achieve rapid and high-precision single vertebra registration in clinical orthopedic surgery, a designed transformation parameter feature extraction module combined with a lightweight module of channel and spatial attention (CBAM) was used to accurately extract the local single vertebra image transformation information. Subsequently, the fusion regression module was used to complement the features of the anterior posterior (AP) and lateral (LAT) images to improve the accuracy of the registration parameter regression. Two 1×1 convolutions were used to reduce the parameter calculation amount, improve computational efficiency, and accelerate intraoperative registration time. Finally, the regression module outputed the final transformation parameters. Comparative experiments were conducted using traditional iterative methods (Opt-MI, Opt-NCC, Opt-C2F) and existing deep learning methods convolutional neural network (CNN) as control group. The registration accuracy (mRPD), registration time, and registration success rate were compared among the iterative methods. Results: Through experiments on real CT data, the image-guided registration accuracy of the proposed method was verified. The method achieved a registration accuracy of (0.81±0.41) mm in the mRPD metric, a rotational angle error of 0.57°±0.24°, and a translation error of (0.41±0.21) mm. Through experimental comparisons on mainstream models, the selected DenseNet alignment accuracy was significantly better than ResNet as well as VGG (both P<0.05). Compared to existing deep learning methods [mRPD: (2.97±0.99) mm, rotational angle error: 2.64°±0.54°, translation error: (2.15±0.41) mm, registration time: (0.03±0.05) seconds], the proposed method significantly improved registration accuracy (all P<0.05). The registration success rate reached 97%, with an average single registration time of only (0.04±0.02) seconds. Compared to traditional iterative methods [mRPD: (0.78±0.26) mm, rotational angle error: 0.84°±0.57°, translation error: (1.05±0.28) mm, registration time: (35.5±10.5) seconds], registration efficiency of the proposed method was significantly improved (all P<0.05). The dual-position study also compensated for the limitations in the single-view perspective, and significantly outperforms both the front and side single-view perspectives in terms of positional transformation parameter errors (both P<0.05). Conclusion: Compared to existing methods, the proposed CT and X-ray registration method significantly reduces registration time while maintaining high registration accuracy, achieving efficient and precise single vertebra registration.

[Recurrence and metastasis of pheochromocytoma/paraganglioma after tumor resection and clinical characteristics analysis].

Objective: The purpose of this study is to investigate the incidence of recurrence or metastasis of pheochromocytoma/paraganglioma (PPGL) patients after primary tumor resection, and to compare the differences of clinical indicators between patients with or without recurrence or metastasis. Methods: This study is a retrospective study. All 157 patients were followed up after tumor resection in Peking Union Medical College Hospital from 2008 to 2016. We obtained the basic information [age of diagnosis, gender, height, weight and body mass index (BMI)], the onset status of PPGL (age of onset, course of disease, family history, tumor location, whether the tumor is bilateral or multiple, and preoperative blood pressure), clinical and pathological features of PPGL tumor (tumor size, whether it could adhere, invade or infiltrate during operation, whether the tumor capsule is smooth and complete on the postoperative pathological diagnosis, whether there is infiltration growth and cystic necrosis on tumor pathology and Ki-67 index), and laboratory examination results [24 hours urinary norepinephrine (NE), epinephrine (E), dopamine (DA) before operation]. According to the outpatient or telephone follow-up, the postoperative incidences of recurrence and metastasis were explored, and the basic information, status of onset, clinical and pathological characteristics of tumors, and laboratory test results of patients were compared. Results: A total of 157 patients, 69 males and 88 females, were with an average age of (42.4±13.4) years old. There were 103 patients with PCC and 54 with PGL. The average follow-up time was (9.5±2.0) years. Of the 103 patients with PCC, 13 (12.6%) had postoperative recurrence and 9 (8.7%) had distant metastasis. Compared with the patients without recurrence and metastasis, the onset age of the 13 patients with recurrence was younger [(27.3±15.7) years vs (39.3±12.2) years, P=0.003], the course of disease was longer [48.0 (23.0, 141.0) months vs 12.0 (4.0, 60.0) months, P=0.010]. The tumor size of 9 patients with distant metastasis was larger [8.0 (6.1, 12.8) cm vs 5.0 (4.0, 7.0) cm, P=0.027]. Of the 54 patients with PGL, 8 (14.8%) had postoperative recurrence and 5 (9.3%) had distant metastasis. Compared with the patients without recurrence and metastasis, the course of disease of the 8 patients with recurrence was longer [90.0 (36.3, 165.0) months vs 24.0 (8.0, 72.0) months, P=0.009], and the proportion of primary tumors with multiple lesions was higher (4/8 vs 4.4%, P=0.003). The preoperative diastolic blood pressure was higher in 5 patients with distant metastasis [(146.0±32.1) mmHg vs (120.6±25.3) mmHg, P=0.043] (1 mmHg=0.133 kPa), and the proportion of primary tumors with multiple lesions was higher (2/4 vs 4.4%, P=0.029). Conclusion: PPGL patients are prone to have recurrence or metastasis. PPGL patients with postoperative recurrence or distant metastasis had younger onset age, longer course of disease, larger tumor size and higher proportion of multiple lesions.

[Radiographic assessment of vertebral artery injury in anterior cervical surgery in healthy adults].

Objectives: To study the relationship between the anatomical parameters of transverse foramen and intervertebral discs in the cross-section of the cervical spine in healthy adults, and to evaluate the risk of vertebral artery injury in the anterior cervical spine surgery. Methods: There were 24 healthy adults(12 male, 12 female) underwent neck CT angiography with clear vertebral artery and the adjacent structure imaging from June to December 2014 in Huashan Hospital, Fudan University. The anatomical parameters of vertebral artery V2 segment with lower cervical vertebrae and intervertebral discs were measured by cross-sectional images of C(3-6). The corresponding parameters of different sex and both sides of the same segment were analyzed by independent samples t-test and paired t test, respectively. The least significant difference(LSD) t test was used to compare the corresponding data between different segments. Results: The vertebral artery was not walking in the middle of the transverse foramen in healthy individual, but partial medial, partial front walking. Transverse diameter of transverse foramen in male and female were 6.62-6.89 mm and 6.21-6.45 mm, and sagittal diameter was 5.41-6.48 mm and 5.40-6.10 mm, respectively.The transverse foramen were slightly oval. The distance between vertebral artery and midline in male and female were 14.23-16.12 mm and 13.60-15.04 mm, respectively, which was much larger than the width of cervical vertebral corpectomy. Compared with C(3-4), intervertebral disc, the transverse distance between the vertebral artery and the uncovertebral joint of C(4-5), C(5-6) was smaller, and the distance from the vertebral artery to the posterior margin of the uncovertebral joint was relatively small, the difference was statistically significant (t=2.449, P=0.022). The distance from vertebral artery to the posterior margin of uncinate process was 1/5-2/5 of the distance between the anterior and posterior edge of the corresponding segmental vertebra. Conclusion: Based on this anatomical study, the risk of vertebral artery injury in conventional anterior cervical decompression is small, and the risk of vertebral artery injury in different segments is slightly different.

Localization and expression of histone H2A variants during mouse oogenesis and preimplantation embryo development.

Epigenetic modifications of the genome, such as histone H2A variants, ensure appropriate gene activation or silencing during oogenesis and preimplantation embryo development. We examined global localization and expression of the histone H2A variants, including H2A.Bbd, H2A.Z and H2A.X, during mouse oogenesis and preimplantation embryo development. Immunocytochemistry with specific antibodies against various histone H2A variants showed their localization and changes during oogenesis and preimplantation development. H2A.Bbd and H2A.Z were almost absent from nuclei of growing oocytes (except 5-day oocyte), whereas H2A.X was deposited in nuclei throughout oogenesis and in preimplantation embryos. In germinal vesicle (GV) oocyte chromatin, H2A.Bbd was detected as a weak signal, whereas no fluorescent signal was detected in GV breakdown (GVBD) or metaphase II (MII) oocytes; H2A.Z showed intense signals in chromatin of GV, GVBD and MII oocytes. H2A. Bbd showed very weak signals in both pronucleus and 2-cell embryo nuclei, but intense signals were detected in nuclei from 4-cell embryo to blastula. The H2A.Z signal was absent from pronucleus to morula chromatin, whereas a fluorescent signal was detected in blastula nuclei. Our results suggest that histone H2A variants are probably involved in reprogramming of genomes during oocyte meiosis or after fertilization.

De novo DNA methylation of the paternal genome in 2-cell mouse embryos.

The developmental dynamics of DNA methylation events have been well studied. Active demethylation of the paternal genome occurs in the zygote, passive demethylation occurs during cleavage stages, and de novo methylation occurs by the blastocyst stage. It is believed that the paternal genome has lower levels of methylation during early development than the maternal genome. However, in this study, we provide direct and indirect evidence of genome-wide de novo DNA methylation of the paternal genome after the first cell cycle in mouse embryos. Although very little methylation was detected within the male pronucleus in zygotes, an intense methylation signal was clearly visible within the androgenetic 2-cell embryos. Moreover, the DNA methylation level of the paternal genome in the post-zygotic metaphase embryos was similar to that of the maternal genome. Using indirect immunofluorescence with an antibody to methylated lysine 9 in histone H3, we provided new evidence to support the concept of spatial compartmentalization of parental genomes in 2-cell mouse embryos. Nevertheless, the transient segregation of parental genomes was not observed by determining the DNA methylation distribution in the 2-cell embryos even though DNA methylation asymmetry between the maternal and paternal pronucleus existed in the 1-cell stage. The disappearance of separate immunofluorescence signals of 5-methyl cytosine in the 2-cell embryos might be attributed to the de novo methylation of the paternal genome during the first mitotic cycle.

Changes in the expression of Fox O1 and death ligand genes during follicular atresia in porcine ovary.

Follicular atresia, a key phenomenon in follicle development, eliminates most of the follicles in mammalian ovaries. To investigate the molecular mechanism of follicular atresia in porcine ovaries, we investigated the mRNA expression of three important cell death ligand-receptor systems and Fox O1 in follicles with a diameter of 3-5 mm. The phosphorylation and subcellular localization of Fox O1 during granulosa cell apoptosis was also determined. TRAIL and Fas L played an important role in follicular atresia at this stage. Fox O1 expression was upregulated during atresia, and was confined to the nucleus of granulosa cells; however, phosphorylated Fox O1 was localized to the cytoplasm. These results suggest Fox O1 involvement in the regulation of TRAIL and Fas L expression during follicular atresia in pigs.

Hydroxysafflor yellow A suppresses liver fibrosis induced by carbon tetrachloride with high-fat diet by regulating PPAR-γ/p38 MAPK signaling.

CONTEXT: One approach to protect against liver fibrosis is the use of herb-derived natural compounds, such as hydroxysafflor yellow A (HSYA). The antifibrosis effect of HYSA against liver fibrosis has been investigated; however, its mechanisms have not yet been entirely revealed. OBJECTIVES: To study the protective effects of HSYA on liver fibrosis induced by carbon tetrachloride (CCl4) and a high-fat diet (HFD), and to determine the mechanism of action of HSYA. MATERIALS AND METHODS: CCl4 and HFD were used to mimic liver fibrosis in rats, and serum biochemical indicators were determined. The antifibrosis effects of HSYA were evaluated and its mechanisms were investigated by histopathological analysis, immunohistochemical staining, enzyme-linked immunosorbent assays, real-time-PCR, and western blotting. RESULTS: HSYA reduced CCl4- and HFD-mediated liver fibrosis and ameliorated serum biochemical indicator, downregulated the expression of tissue inhibitor of metalloproteinase-1 (TIMP-1) (0.31 ± 0.03 protein, 0.59 ± 0.02 mRNA) and transformin growth factor-ß1 (TGF-ß1) (0.81 ± 0.02 protein, 0.58 ± 0.04 mRNA), and upregulated the expression of peroxisome proliferator-activated receptor-γ (PPAR-γ) (1.57 ± 0.13 protein, 2.48 ± 0.19 mRNA) and matrix metallopeptidases-2 (MMP-2) (2.31 ± 0.16 protein, 2.79 ± 0.22 mRNA) (p < 0.01, versus model group). These effects were significantly attenuated by PPAR-γ antagonist GW9662 via blocking the phosphorylation of p38 MAPK. DISCUSSION AND CONCLUSION: These data demonstrate a novel role for HSYA in inhibiting CCl4- and HFD-mediated liver fibrosis, and reveal that PPAR-γ and p38 MAPK signaling play pivotal roles in the prevention of liver fibrosis induced by CCl4 and HFD.

Generation of induced pluripotent mouse stem cells in an indirect co-culture system.

Typically, production of induced pluripotent stem cells requires direct contact with feeder cells. However, once the stem cells have reached the appropriate maturation point, it is difficult to separate them from feeder cells, which must be irradiated with γ-rays or treated with the antibiotic mitomycin-C. We used a microporous poly-membrane-based indirect contact co-culture system with mouse embryonic fibroblasts to induce mouse pluripotent stem cells without radiation or antibiotics. We found that induced pluripotent stem cells induced by this co-culture method had a reprogramming efficiency and time similar to those induced using traditional methods. Furthermore, strongly expressed pluripotent markers showed a normal karyotype and formation and contained all three germ layers in a teratoma.

MiR-223-5p inhibitor suppresses microglia inflammation and promotes Nrg-1 in rats of spinal cord injury.

OBJECTIVE: The aim of this study was to investigate the role of microRNA-233-5p (miR-233-5p) in spinal cord injury (SCI), and to explore the possible underlying mechanism. MATERIALS AND METHODS: Microglia were first isolated from neonate rats and cultured in a suitable environment in vitro. Lipopolysaccharide (LPS) and interleukin-4 (IL-4) were used to activate microglia. The expressions of miR-223-5p, inducible nitric oxide synthase (iNOS) and arginase 1 (Arg-1) were measured by qRT-PCR, respectively. After transfection of miR-233-5p inhibitor, the expression levels of miR-223-5p, iNOS and Arg-1 in cells were detected as well. A moderate SCI model was successfully established in rats (10 g fallen on T10 spinal cord at the height of 5 cm). Subsequently, inflammation indexes at miR-223-5p peak moment were observed. Meanwhile, its neuro-protective effect at 28 days after SCI was estimated. Finally, Basso, Beattie, and Bresnahan (BBB) rating scale was applied to evaluate the hindlimb locomotor function of rats at 1, 3, 7, 14, 21, 28 days after SCI. RESULTS: MiR-223-5p inhibitor significantly promoted M2 microglia expression and degenerated M1 microglia expression in vitro. SCI elevated the level of miR-223-5p in injured spinal cord tissues within one week, which reached a peak at 5 days after injury. Meanwhile, miR-223-5p inhibitor remarkably reduced the expressions of inflammatory factors, including interleukin-1 beta (IL-1ß), interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) at 3 days after SCI, as well as increased neuregulin1 (NRG-1) expression. However, miR-223-5p inhibitor significantly declined the levels of apoptosis key enzyme-caspase-3 and glia reaction marker-glial fibrillary acidic protein (GFAP) at 7 and 28 days after SCI, respectively. As a result, BBB rating scale demonstrated that hindlimb locomotor function was significantly recovered in miR-223-5p injection group. CONCLUSIONS: MiR-223-5p was up-regulated in M1 microglia, whereas down-regulated in M2 microglia. MiR-223-5p inhibitor could significantly increase M2 microglia expression, while decrease M1 microglia expression in vitro. In vivo, miR-223-5p inhibitor suppressed the inflammatory response and reinforced NRG-1 level to reduce glia reaction and neuron apoptosis. Thereby, its treatment promoted the hindlimb locomotor function of rats.

Effect of bending rigidity in a dynamic model of a polyurethane prosthetic mitral valve.

We investigate the behaviour of a dynamic fluid-structure interaction model of a chorded polyurethane mitral valve prosthesis, focusing on the effects on valve dynamics of including descriptions of the bending stiffnesses of the valve leaflets and artificial chordae tendineae. Each of the chordae is attached at one end to the valve annulus and at the other to one of two chordal attachment points. These attachment points correspond to the positions where the chords of the real prosthesis would attach to the left-ventricular wall, although in the present study, these attachment points are kept fixed in space to facilitate comparison between our simulations and earlier results obtained from an experimental test rig. In our simulations, a time-dependent pressure difference derived from experimental measurements drives flow through the model valve during diastole and provides a realistic pressure load during systole. In previous modelling studies of this valve prosthesis, the valve presents an unrealistically large orifice at beginning of diastole and does not close completely at the end of diastole. We show that including a description of the chordal bending stiffness enables the model valve to close properly at the end of the diastolic phase of the cardiac cycle. Valve over-opening is eliminated only by incorporating a description of the bending stiffnesses of the valve leaflets into the model. Thus, bending stiffness plays a significant role in the dynamic behaviour of the polyurethane mitral valve prosthesis.