[A preliminary report of laparoscopic extraperitoneal colostomy anterior to posterior sheath of rectus abdominis-transversus abdominis to prevent parastomal hernia].

Objective: To examine the preliminary effect of laparoscopic extraperitoneal colostomy anterior to posterior sheath of rectus abdominis-transversus abdominis for the prevention of parastomal hernia after abdominoperineal resection for rectal cancer. Methods: This study is a prospective case series study. From June 2021 to June 2022, patients with low rectal cancer underwent laparoscopic abdominoperineal resection combined with extraperitoneal colostomy anterior to posterior sheath of rectus abdominis-transversus abdominis at the First Department of General Surgery, Shaanxi Provincial People's Hospital were enrolled. The clinical data and postoperative CT images of patients were collected to analyze the incidence of surgical complication and parastomal hernia. Results: Totally 6 cases of patient were enrolled, including 3 males and 3 females, aging 72.5 (19.5) years (M(IQR)) (range: 55 to 79 years). The operation time was 250 (48) minutes (range: 190 to 275 minutes), the stoma operation time was 27.5 (10.7) minutes (range: 21 to 37 minutes), the bleeding volume was 30 (35) ml (range: 15 to 80 ml). All patients were cured and discharged without surgery-related complications. The follow-up time was 136 (105) days (range: 98 to 279 days). After physical examination and abdominal CT follow-up, no parastomal hernia occurred in the 6 patients up to this article. Conclusions: A method of laparoscopic extraperitoneal colostomy anterior to posterior sheath of rectus abdominis-transversus abdominis is established. Permanent stoma can be completed with this method safely. It may have a preventive effect on the occurrence of parastomal hernia, which is worthy of further study.

Three-Dimensional Dirac Phonons with Inversion Symmetry.

Dirac semimetals associated with bulk Dirac fermions are well known in topological electronic systems. In sharp contrast, three-dimensional (3D) Dirac phonons in crystalline solids are still unavailable. Here we perform symmetry arguments and first-principles calculations to systematically investigate 3D Dirac phonons in all space groups with inversion symmetry. The results show that there are two categories of 3D Dirac phonons depending on their protection mechanisms and positions in momentum space. The first category originates from the four-dimensional irreducible representations at the high symmetry points. The second category arises from the phonon branch inversion, and the symmetry guarantees Dirac points to be located along the high symmetry lines. Furthermore, we reveal that nonsymmorphic symmetries and the combination of inversion and time-reversal symmetries play essential roles in the emergence of 3D Dirac phonons. Our work not only offers a comprehensive understanding of 3D Dirac phonons but also provides significant guidance for exploring Dirac bosons in both phononic and photonic systems.

Two-Dimensional Dirac Semimetals without Inversion Symmetry.

Realizing stable two-dimensional (2D) Dirac points against spin-orbit coupling (SOC) has attracted much attention because it provides a platform to study the unique transport properties. In previous work, Young and Kane [Phys. Rev. Lett. 115, 126803 (2015)PRLTAO0031-900710.1103/PhysRevLett.115.126803 proposed stable 2D Dirac points with SOC, in which the Berry curvature and edge states vanish due to the coexistence of inversion and time-reversal symmetries. Herein, using the tight-binding model and k·p effective Hamiltonian, we present that 2D Dirac points can survive in the presence of SOC without inversion symmetry. Such 2D Dirac semimetals possess nonzero Berry curvature near the crossing nodes, and two edge states are terminated at one pair of Dirac points. In addition, according to symmetry arguments and high-throughput first-principles calculations, we identify a family of ideal 2D Dirac semimetals, which has nonzero Berry curvature in the vicinity of Dirac points and visible edge states, thus facilitating the experimental observations. Our work shows that 2D Dirac points can emerge without inversion symmetry, which not only enriches the classification of 2D topological semimetals but also provides a promising avenue to observe exotic transport phenomena beyond graphene, e.g., nonlinear Hall effect.

Symmetry-Protected Topological Triangular Weyl Complex.

Weyl points are often believed to appear in pairs with opposite chirality. In this work, we show by first-principles calculations and symmetry analysis that single Weyl phonons with linear dispersion and double Weyl phonons with quadratic dispersion are simultaneously present between two specific phonon branches in realistic materials with trigonal or hexagonal lattices. These phonon Weyl points are guaranteed to locate at high-symmetry points due to the screw rotational symmetry, forming a unique triangular Weyl complex. In sharp contrast to conventional Weyl systems with surface arcs terminated at the projections of a pair of Weyl points with opposite chirality, the phonon surface arcs of the unconventional triangular Weyl complex connect the projections of one double Weyl point and two single Weyl points. Importantly, the phonon surface arcs originating from the triangular Weyl complex are extremely long and span the entire surface Brillouin zone. Furthermore, there are only nontrivial phonon surface states across the isofrequency surface, which facilitates their detection in experiments and further applications. Our work not only offers the promising triangular phonon Weyl complex but also provides guidance for exploring triangular Weyl bosons in both phononic and photonic systems.

Robust Twin Pairs of Weyl Fermions in Ferromagnetic Oxides.

The ferromagnetic Weyl semimetals with inversion symmetry usually possess odd pairs of Weyl fermions. Here, we present an inversion eigenvalue argument to dictate the existence of even pairs of ferromagnetic Weyl fermions. We show, by a combination of first-principles calculations and symmetry analyses, that this exotic topological feature can be verified in ferromagnetic oxides in different space groups. In particular, a realistic candidate, i.e., hollandite RbCr_{4}O_{8} with a high Curie temperature (∼295 K), hosts intriguing twin pairs of Weyl fermions, which are robustly stable against perturbations. Moreover, our effective model and symmetry analysis show that the twin pairs of Weyl fermions originate from a mirrored nodal ring pair. The nontrivial surface states and Fermi arcs of RbCr_{4}O_{8} are clearly visible, further revealing the topological features. This work strengthens the understanding of the parity analysis in exploring ferromagnetic topological materials with unconventional fermionic excitations.

Laparoscopic transcystic common bile duct exploration: surgical indications and procedure strategies.

BACKGROUND: LTCBDE combined with or without modified techniques is safe and efficacious for the management of gallstones and concomitant, even large, common bile duct (CBD) stones. METHODS: To describe the surgical indications and procedure strategies of laparoscopic transcystic common bile duct exploration (LTCBDE), a retrospective analysis of 205 patients with concomitant gallstones and CBD stones treated using LTCBDE between June 2008 and June 2015 was performed. Clinical data on disease characteristics, methods for cystic duct incision and CBD stone extraction (with or without laser lithotripsy), and surgical outcomes were collected and reviewed. RESULTS: CBD stones were successfully cleared in all patients. No patient was converted to choledochotomy or laparotomy. The cystic duct diameter ranged 3-8 mm, and 85 patients with cystic duct diameter ≥ 5 mm. The mean time for CBD stone extraction was 25.3 min, with the operative time ranged from 63 to 170 min. Lithotripsy was used in 74 (36.1%) patients among which 26 patients with cystic duct diameter ≥ 5 mm. Estimated blood loss during surgery was 10-120 ml per patient, and no intra-operative blood transfusions were needed. The mean postoperative hospital stay was 5.1 (range 3-7) days, and postoperative complications developed in seven patients. No bile duct injury, stricture, remnant, recurrent stones, or other adverse events were observed during the mean follow-up of 8 months. CONCLUSIONS: Based on preoperative MRCP and intra-operative IOC findings about cystic duct diameter, the diameter of CBD, CBD stone size, we summarized and proposed the surgical indications and suitable techniques and strategies during LTCBDE.

[Role and mechanism of lipopolysaccharide induced exosome in the pathogenesis of acute lung injury].

Objective: To explore the effect and mechanism of exosome derived from lipopolysaccharide (LPS)-induced mouse macrophage (RAW264.7) on acute lung injury. Methods: RAW264.7 were cultured in vitro and divided into 2 groups: control group and LPS-induced group. The exosomes were extracted from the two groups of cell supernatant by ultracentrifugation and classified into 2 groups: C-EXO group and LPS-EXO group. In vivo, random allocation was used to averagely divide the eighteen male C57BL/6 mice into 3 groups: control group, EXO-control group and EXO-LPS group. All mice were sacrificed after 12 h. The lung tissue was used for HE staining to assess the degree of acute lung injury as well as immunohistochemical staining for interleukin (IL) -1ß and tumor necrosis factor (TNF)-α. The tissue protein expression levels of IL-1ß, TNF-α, ß-catenin, E-cadhein, ZO-1 and Occludin were measured by Western blot. In vitro, alveolar type Ⅱ epithelial cells (MLE-12) were cultured and divided into 3 groups: C-control group, EXO-control-induced group and EXO-LPS-induced group. The tissue protein expression levels of IL-1ß, TNF-α, and Occludin were measured by Western blot after 12 h. Results: The two samples of C-EXO group and LPS-EXO group was proved to be exosomes. Under a light microscope, the lung tissue of EXO-LPS group showed inflammatory cell infiltration, hemorrhage, interstitial and alveolar edema, and the thickness of alveolar septum. The tissue protein levels of IL-1ß and TNF-α in EXO-LPS group were obviously higher than the control group, EXO-control group (1.331±0.203 and 0.274±0.018, 0.892±0.074; 0.800±0.096 and 0.596±0.025, 0.441±0.061; all P<0.05). While the tissue protein levels of Occludin showed the opposite phenomenon (0.251±0.021 and 0.862±0.029, 0.453±0.013; all P<0.05). In vitro, Compared with the C-control group and the EXO-control-induced group, the expression levels of IL-1ß and TNF-α increased significantly in the EXO-LPS-induced group (0.900±0.033 and 0.320±0.030, 0.661±0.028; 0.739±0.045 and 0.151±0.024, 0.360±0.037; all P<0.05). whereas the protein levels of Occludin expression were reversed in MLE-12 (0.585±0.082 and 0.941±0.090, 0.732±0.083; all P<0.05). Conclusion: Exosomes derived from LPS-induced RAW264.7 can induced the acute lung injury by affecting barrier function, which probably is related to the low degree of Occludin in alveolar type Ⅱ epithelial cells.

[Role of Yes-associated protein 1 in angiotensinâ ¡-induced pulmonary fibrosis in rats].

Objective: To explore the mechanism of Yes-associated protein 1 (Yap1) in angiotensinⅡ(AngⅡ)-induced pulmonary fibrosis. Methods:In vivo, 18 male Wistar rats were randomly divided into three equal groups with 6 rats in each group, including control group, bleomycin-treated group (BLM), and BLM+ AngⅡ group. 28 days later, the lung tissues in all groups were harvested for the HE and Masson staining as well as the immunohistochemical (IHC) staining for Yap1. In vitro, the isolated fibroblasts were treated with 10(-7) mmol/L AngⅡor the AngⅡ-targeted inhibitor irbesartan for the scheduled time for mRNA and protein expressions of Yap1, PDZ-binding motif (TAZ), and collagen Ⅰusing PCR and Western blot, as well as the translocation test from the nucleus to the cytoplasm of Yap1 and TAZ. Subsequently, the fibroblasts were assigned into 4 groups: the empty plasmid (vector) group, the vector+ AngⅡ group, the Yap1 shRNA group, and the Yap1 shRNA+ AngⅡ group. Western blot was used to detect the relative expressions of Yap1, TAZ, Smad3 and collagen Ⅰ. The CCK-8 and EdU assays were performed to determine the proliferative capacity. Results:In vivo, severe lung fibrosis and increased Yap1 expression of IHC staining were found in BLM group. Additionally, more severe lung fibrosis and higher Yap1 expression were detected in the BLM+ AngⅡ group than the BLM group (both P<0.05). In vitro, both the mRNA and protein relative expressions of Yap1, TAZ and collagenⅠ were markedly higher in AngⅡ-treated groups than the control group (all P<0.05). Meanwhile, the relative expression of phosphorylated Yap1 reached its peak at 2 h after AngⅡ stimulation. In the protein translocation tests, after treated with AngⅡ for 24 h, the relative protein levels of Yap1 and TAZ in the nucleus of the AngⅡ group were significantly higher than those in the control group (0.382±0.007 vs 0.031±0.001, 1.097±0.030 vs 0.357±0.015). However, the relative protein expressions in the cytoplasm of the AngⅡ group were obviously less than that in the control group (0.323±0.058 vs 0.418±0.044, 0.858±0.059 vs 1.201±0.015). Compared with the AngⅡ group, the expressions of Yap1 and TAZ in the AngⅡ+ irbesartan group were higher in cytoplasm (0.598±0.060 vs 0.323±0.058, 1.495±0.052 vs 0.858±0.059), while lower in the nucleus (0.323±0.058 vs 0.418±0.044, 0.858±0.059 vs 1.201±0.015) (all P<0.05). Furthermore, the relative protein expressions of Yap1, TAZ, Smad3 and collagenⅠin Yap1 shRNA+ AngⅡ group were distinctly lower than the vector+ AngⅡ group (all P<0.05). In the cell proliferation tests, the absorbance and the percentage of EdU positive cells of vector+ AngⅡ group exceeded that of vector group (both P<0.05). However, the absorbance and the percentage of EdU positive cells in the Yap1 shRNA+ AngⅡgroup were less than the vector+ AngⅡ group (both P<0.05). Conclusion: AngiotensinⅡ promoted the collagen synthesis and cell proliferation in primary lung fibroblasts by increasing the Yap1 activity, leading to the progress of fibrosis.

[Mechanism of angiotensin-converting enzyme 2 overexpression improving collagen synthesis in lung].

Objective: To explore the mechanism of angiotensin-converting enzyme 2 (ACE2) overexpression improving collagen synthesis in lung. Methods: Lung fibroblasts of mice over-expressing ACE2 and the wild type (WT) were cultured in vitro and divided into 5 groups: WT-control, WT-AngiotensinⅡ (AngⅡ), ACE2(+ /+) -control, ACE2(+ /+) -AngⅡ and ACE2(+ /+) -AngⅡ+ A779. The protein relative expression levels of ACE2, collagen Ⅰ, nicotinamide adenine dinucleotide phosphate oxidase 4 (NOX4), nucleotide binding and oligomerization domain-like receptor family pyrin domain-containing 3 (NLRP3), autophagy-related protein (Beclin1), ubiquitin-binding protein p62 (P62), microtubule-associated proteins light chain 3-Ⅱ (LC3-Ⅱ) were measured by Western blot and triphosadenine (ATP) level was measured by ATP Assay Kit. Fibroblasts over-expressing ACE2 were pretreated with or without the autophagy inhibitor and were separated into 4 groups: ACE2(+ /+) -control, ACE2(+ /+) -AngⅡ, ACE2(+ /+) -AngⅡ+ 3-MA and ACE2(+ /+) -3-MA. In vivo, random allocation was used to averagely divide mice into four groups: WT-control, WT-Bleomycin (BLM), ACE2(+ /+) - control, ACE2(+ /+) -BLM. Wild type and ACE2 over-expressing mice were instilled with bleomycin endotracheally (3.5 mg/kg) or the same volume saline. All mice were sacrificed after 28 days and the lung tissue were used for HE and Masson staining as well as immunohistochemical staining for NOX4, P62 and LC3. Results: The vimentin in lung fibroblasts isolated from mice was proved to be positive by both immunohistochemical and immunofluorescence. The ACE2 protein level of lung fibroblasts over-expressing ACE2 was higher than the wild type (0.202±0.062 and 0.067±0.040, P<0.05). The protein levels of collagenⅠ, NOX4 and NLRP3 in WT-AngⅡ group were obviously higher than the WT-control group (0.861±0.129 and 0.417±0.076, 0.432±0.036 and 0.318±0.058, 0.367±0.125 and 0.045±0.012, all P<0.05). The difference of collagenⅠand NLRP3 between ACE2(+ /+) -AngⅡ group and ACE2(+ /+) -control group had no statistical significance (all P>0.05). CollagenⅠand NOX4 protein level in ACE2(+ /+) -AngⅡ+ A779 group were observably higher than ACE2(+ /+) - AngⅡ group (0.707±0.155 and 0.458±0.108, 0.299±0.038 and 0.149±0.090, all P<0.05). The autophagy related protein levels of Beclin1, P62 and LC3-Ⅱ in ACE2(+ /+) -control group were distinctly higher than WT-control group (0.834±0.051 and 0.274±0.018, 0.467±0.078 and 0.093±0.025, 0.494±0.065 and 0.150±0.054, all P<0.05). However, these protein levels in ACE2(+ /+) -AngⅡ+ A779 group were lower than ACE2(+ /+) -AngⅡ group (1.331±0.203 and 1.565±0.069, 0.298±0.096 and 0.438±0.077, 0.464±0.093 and 0.768±0.071, all P<0.05). ACE2(+ /+) -AngⅡ+ 3-MA group had higher collagenⅠ (0.383±0.125 and 0.032±0.013, P<0.05) and lower LC3-Ⅱ protein level (1.177±0.140 and 1.387±0.183, P<0.05) than AngⅡ group. In bleomycin induced lung fibrosis in mice, ACE2(+ /+) -BLM mice exhibited milder lung fibrosis and lower NOX4 protein level but higher LC3-Ⅱprotein level compared with WT-BLM mice. Conclusion: ACE2 over-expression ameliorated collagen synthesis through enhancing autophagy in lung.

Establishment of a visualized nude mouse model of cervical carcinoma with high potential of lymph node metastasis via total orthotopic transplantation.

OBJECTIVE: To screen cervical carcinoma (CC) SiHa subgroups with high potential of lymphatic metastasis and establish a visualized nude mouse model of cervical carcinoma with a total orthotopic transplantation approach. METHODS: A cervical carcinoma SiHa subgroup with high potential of lymphatic metastasis was isolated by in vitro and in vivo primary culture and continuous passage screening of cervical carcinoma SiHa cells that stably expressed enhanced green fluorescent protein (EGFP). Forty male nude mice aged 6-8 weeks were equally randomized to group A receiving unscreened SiHa/EGFP cells, and group B received in vitro and in vivo screened SiHa/EGFP cells with high potential of lymph node metastasis. RESULTS: In the 20 animals of group A receiving orthotopic transplantation of unscreened SiHa/EGFP cells, the primary tumors were small; local lymph node metastasis was observed in five animals; local organ invasion and distal lymph node metastasis were observed in two animals; and no lung metastasis was observed. In the 20 animals of group B receiving screened SiHa/EGFP cells, local lymph node metastasis occurred in all animals; distal lymph node metastasis was observed in 18 animals; and lung metastasis was observed in seven animals. CONCLUSION: A cervical carcinoma SiHa subgroup with high potential of lymphatic metastasis was isolated and a visualized nude mouse model of cervical carcinoma with high potential of lymph node metastasis was established through total orthotopic transplantation successfully. This provided a good platform for the further study of cervical carcinoma-related mechanisms, especially mechanisms of lymphatic metastasis in cervical carcinoma.

Continuous culture of neuronal cells from adult human olfactory epithelium.

Cells from the olfactory epithelium of adult human cadavers have been propagated in primary culture and subsequently cloned. These cells exhibit neuronal properties including: neuron-specific enolase, olfactory marker protein, neurofilaments, and growth-associated protein 43. Simultaneously, the cells exhibit nonneuronal properties such as glial fibrillary acidic protein and keratin, the latter suggesting properties of neuroblasts or stem cells. These clonal cultures contain 5-10% of cells sufficiently differentiated to show odorant-dependent cyclic adenosine 3',5'-monophosphate (cAMP) or calcium-release responses when challenged with submicromolar concentrations of odorants. The potential of culturing neuronal cells from patients with neuropsychiatric disorders, such as Alzheimer's disease or schizophrenia, could enable the study of the pathophysiology of these neurons in the culture dish and allow new approaches to the study of mental illness.