[Safety and efficacy of a new domestic distal perforated stent graft in the treatment of Stanford type B aortic dissection].

Objective: To evaluate the safety and efficacy of a new domestic distal perforated stent graft (Talos stent) in the treatment of Stanford type B aortic dissection (TBAD). Methods: Twenty-five patients with TBAD treated with Talos stent in Yan'an Hospital Affiliated to Kunming Medical University from February 2018 to December 2019 were selected as the research subjects. Intraoperative angiography was performed to determine the number of branch arteries that remained after stent release. On postoperative day 5 (POD5), the pain intensity of the patients was evaluated by visual analog scale (VAS). The computed tomography angiography (CTA) of the patients before operation, 6 months and 12 months after operation were compared including aortic diameter, true lumen diameter, and false lumen diameter at the level of tracheal bifurcation. Follow-up was performed 1 month, 6 months, 12 months, and 24 months after surgery, and the occurrence of stent-related adverse events, reoperation and survival rate were recorded. Results: The enrolled patients included 19 males and 6 females, aged (52.6±11.1) years. Intraoperative angiography showed that 4 (1, 7) branch arteries were preserved, and the VAS score was 1 (0, 1) on POD5. The aortic diameters at the level of the tracheal bifurcation were (34.9±1.1) mm, (34.6±0.9) mm and (34.8±1.0) mm before surgery, 6 months and 12 months after surgery, and there was no significant difference (P=0.926); the diameters of the main true lumen at the level of the tracheal bifurcation were (13.3±1.6) mm, (21.8±1.0) mm and (22.3±1.1) mm before surgery, 6 months and 12 months postoperatively, while the diameters of the main false lumen at the level of the tracheal bifurcation were (20.8±2.2) mm, (4.5±1.5) mm, and (4.6±1.7) mm, respectively. Compared with before surgery, the diameter of true lumen increased significantly 6 months and 12 months after surgery (both P<0.001), while the diameter of false lumen decreased (both P<0.001). No stent-related adverse events occurred within 30 days after surgery, no secondary operations occurred within 12 months after surgery, no type Ⅰ and type Ⅲ endoleaks, no deaths or cases of paraplegia were reported, and the stent structure and position remained good. There were no deaths or paraplegia cases 24 months postoperatively, and no stent-related adverse events occurred. Conclusion: Using Talos stent in the treatment of TBAD can effectively help remodel the aorta, while preserve the intercostal artery and spinal artery, with good clinical effect and safety.

Regulation of Eye Development by Protein Serine/Threonine Phosphatases-1 and -2A.

The protein serine/threonine phosphatases-1 and -2A are major cellular phosphatases, playing a fundamental role in organisms from prokaryotes to eukaryotes. They contribute to 90% dephosphorylation in eukaryote proteins. In the eye, both phosphatases are highly expressed and display important functions in regulating normal eye development. Moreover, they are implicated in pathogenesis through modulation of stress-induced apoptosis. Here we review the recent progresses on these aspects.

The tumor suppressor, p53 regulates the γA-crystallin gene during mouse lens development.

The tumor suppressor, p53 regulates a large number of target genes to control cell proliferation and apoptosis. In addition, it is also implicated in the regulation of cell differentiation in muscle, the circulatory system and various carcinoma tissues. We have recently shown that p53 also controls lens differentiation. Regarding the mechanism, we reveal that p53 directly regulates several genes including c-Maf and Prox1, two important transcription factors for lens differentiation, and αA and ßA3/A1, the lens differentiation markers. In the present study, we present evidence to show that the γA-crystallin gene distal promoter and the first intron also contain p53 binding sites and are capable of mediating p53 control during mouse lens development. First, gel mobility shifting assays revealed that the p53 protein in nuclear extracts from human lens epithelial cells (HLE) directly binds to the p53 binding sites present in the γA-crystallin gene. Second, the exogenous wild type p53 induces the dose-dependent expression of the luciferase reporter gene driven by the basic promoter containing the γA-crystallin gene p53 binding site. In contrast, the exogenous dominant negative mutant p53 causes a dose-dependent inhibition of the same promoter. Third, ChIP assays revealed that p53 binds to the γA-crystallin gene promoter in vivo. Finally, in the p53 knockout mouse lenses, the expression level of the γAcrystallin gene was found attenuated in comparison with that in the wild type mouse lenses. Together, our results reveal that p53 regulates γA-crystallin gene expression during mouse lens development. Thus, p53 directly regulates all 3 types of crystallin genes to control lens differentiation.

p53 directly regulates αA- and ßA3/A1-crystallin genes to modulate lens differentiation.

It is well established that the tumor suppressor p53 plays major roles in regulating apoptosis and cell cycle progression. In addition, recent studies have demonstrated that p53 is actively involved in regulating cell differentiation in muscle, the circulatory system and various carcinoma tissues. We have recently shown that p53 also controls lens differentiation. Regarding the mechanism, we reveal that p53 directly regulates c-Maf and Prox1, two important transcription factors to control cell differentiation in the ocular lens. In the present study, we present further evidence to show that p53 can regulate lens differentiation by controlling expression of the differentiation genes coding for the lens crystallins. First, the αA and ßA3/A1 gene promoters or introns all contain putative p53 binding sites. Second, gel mobility shifting assays revealed that the p53 protein in nuclear extracts from lens epithelial cells directly binds to the p53 binding sites found in these crystallin gene promoters or introns. Third, exogenous wild type p53 induces dose-dependent expression of the luciferase reporter gene driven by different crystallin gene promoters and the exogenous dominant negative mutant p53 causes dose-dependent inhibition of the same crystallin genes. Fourth, ChIP assays revealed that p53 binds to crystallin gene promoters in vivo. Finally, in the p53 knockout mouse lenses, expression levels of various crystallins were found down-regulated in comparison with those from the wild type mouse lenses. Together, our results reveal that p53 directly regulates expression of different sets of genes to control lens differentiation.

PP-1α and PP-1γ display antagonism and differential roles in tumorigenicity of lung cancer cells.

Protein serine/threonine phosphatases are important cellular signaling molecules and play major roles in regulating many different functions including cell proliferation, senescence, programmed cell death, and oncogenic cell transformation. Among different serine/threonine phosphatases, PP-1 and PP-2A contribute to more than 90% phosphatase activities in eukaryotes. While the functions of PP-2A in cell transformation and tumorigenesis have been well established, the role of PP-1 in carcinogenesis remains to be further explored. Moreover, PP-1 exists in different isoforms, whether these isoforms have differential functions in tumorigenesis remains to be examined. In the present study, we demonstrated that in lung cancer 1299 cells, PP1α and PP- 1 & γ exist in an antagonizing balance. In the parent H1299 cells, PP-1γ is dominant, about 4-fold higher than that of PP-1α. Overexpression of PP-1α significantly down-regulates PP-1γ at both mRNA and protein levels. In contrast, knockdown of PP-1α leads to upregulation of PP-1γ. Moreover, overexpression of PP-1α significantly attenuates the ability of the H1299 cells in promoting tumorigenicity as tested in immuno-deficient nude mice. This attenuation is derived from the halted cell cycle progression, which is largely attributed by the changed RB-E2F activity. Together, our results demonstrate that PP-1α and PP-1γ not only antagonize each other in lung cancer cells, but also display differential functions in tumorigenicity.

Protein serine/threonine phosphotase-1 is essential in governing normal development of vertebrate eye.

Protein serine/threonine phosphatase-1 (PP-1) is one of the key enzymes responsible for dephosphorylation in vertebrates. Protein dephosphorylation via PP-1 is implicated in many different biological processes including gene expression, cell cycle control, transformation, neuronal transmission, apoptosis, autophage and senescence. However, whether PP-1 directly controls animal development remains to be investigated. Here, we present direct evidence to show that PP-1 plays an essential role in regulating eye development of vertebrates. Using goldfish as a model system, we have shown the following novel results. First, inhibition of PP-1 activity leads to death of a majority of the treated embryos, and the survived embryos displayed severe phenotype in the eye. Second, knockdown of each catalytic subunit of PP-1 with morpholino oligomers leads to partial (PP-lα knockdown) or complete (PP-lß or PP-lγ knockdown) death of the injected embryos. The survived embryos from PP-1α knockdown displayed clear retardation in lens differentiation. Finally, overexpression of each subunit of PP-1 also causes death of majority of the injected embryos and leads to abnormal development of goldfish eye. Mechanistically, Pax-6 is one of the major downstream targets mediating the effects of PP-1 function since the eye phenotype in Pax-6 knockdown fish is similar to that derived from overexpression of PP-1. Together, our results for the first time provide direct evidence that protein phosphatase-1 plays a key role in governing normal eye formation during goldfish development.

GEFT, A Rho family guanine nucleotide exchange factor, regulates lens differentiation through a Rac1-mediated mechanism.

The Rho-family of small GTPase specific guanine nucleotide exchange factor, GEFT, is expressed at high levels in adult human excitable tissues including the brain, heart, and skeletal muscle. Previously, we demonstrated that GEFT is specifically expressed in the adult mouse hippocampus and cerebellum, and that overexpression of this protein can result in neurite and dendrite remodeling. This finding prompted us to explore the expression of GEFT in other tissues, which share common developmental ancestry to the nervous system, specifically the ocular system. Using immunohistochemical analysis specific for GEFT protein expression, we observed the highest ocular expression of GEFT occurring in the neuroblastic layer and differentiating lens fibers of the late-stage mouse embryo, and in the postnatal corneal epithelium, lens epithelium, and throughout the retina. Exogenous expression of GEFT in N/N1003A rabbit lens epithelial cells induced lens fiber differentiation as reflected by cell elongation and lentoid formation, as well as a strong increase in ß-crystallin and filensin expression. Moreover, transfection of lens epithelial cells with GEFT resulted in a Rac-1 mediated up-regulation of αA-, αB-, ßB-, γC-, or γF-crystallin promoter activities that is in part dependent on the nuclear localization of Rac1. Furthermore, pharmacological inhibition of Rac1 blocked GEFT-induced N/N1003A lens fiber differentiation and ßB-crystallin expression in ex vivo mouse lens explants. These results demonstrate for the first time a role for GEFT in lens cell differentiation and mouse eye development. Moreover, GEFT regulation of lens differentiation and eye development occurs through a Rac1-dependent mechanism.

Apoptosis: its functions and control in the ocular lens.

The ocular lens is a non-vascular and non-innervated transparent organ that plays an important role in vision processing. This unique organ is derived from the embryonic ectoderm of the brain region through a complicated differentiation process in which apoptosis plays a key role. First, when the committed ectoderm becomes thickened and invaginated, the defined number of cells required to form the lens vesicle is partially determined by apoptosis. Second, separation of lens vesicle from the above corneal ectoderm is executed through apoptosis of the lens stalk cells. Finally, differentiation of the lens epithelial cells is controlled by the regulators, most of which are involved in control of apoptosis at multiple signaling steps. The lens is also characterized by continuous growth and differentiation in the adulthood. Through the different stages of growth and differentiation in the adult lens, various stress conditions can induce apoptosis of the lens epithelial cells, leading to eventual non-congenital cataractogenesis. The present review summarizes the current knowledge on the functions and regulators of apoptosis in the ocular lens.

[Roentgeno-pathologic studies of peripheral pulmonary carcinoma].

122 patients with solitary pulmonary nodular lesions less than 3 cm in diameter admitted to our hospital from 1974 to 1985 are analysed. All lesions were negative by sputum exfoliative cytology and fiberoptic bronchoscopy. As lung cancer could not be excluded, exploratory thoracotomy was performed. They were diagnosed as primary peripheral pulmonary carcinoma by pathology. Of the 122 patients, 45 had adenocarcinoma, 42 squamous-cell carcinoma, 19 bronchiolo-alveolar carcinoma, 9 small cell carcinoma, 4 large cell carcinoma and 3 mixed type carcinoma. Pathologic specimen was compared with X-ray chest films to study the pathologic basis of radiologic manifestations. As there were different histologic types in solitary peripheral pulmonary carcinoma, their pathologic processes were different. Therefore, the radiologic features were also different. Different points of the radiologic manifestations might be helpful to differentiate different histologic types of pulmonary carcinoma and increase the diagnostic accuracy for early pulmonary carcinoma.

[Roentgenodiagnosis of primary lung carcinoma with cavity--analysis of 100 cases].

This paper reports the roentgenopathologic findings of 100 primary lung carcinomas with cavitation. It was found that formation of carcinomatous cavity was related to the histopathologic classification. The cavity could be formed in four ways: 1. Cancer tissue necrosis. 2. Abscess formation after obstructive infection. 3. Cancer infiltration around the bronchial wall leading to bronchial cancer embolus and necrosis. 4. The air-cyst-like lesion formation by check valve obstruction of cancer within the bronchial. A variety of cavity formation could result in different patterns such as: the thick walled cavity (42%), central cavity (28%), consolidation cavity (5%), thin walled cavity (7%), abscess cavity (6%) and spotted cavity (12%). The lobule, spicules or notched margins are usually observed on the outer wall of the thick walled cavity which are considered as the typical manifestation of cancer cavity. The consolidation cavity, thin walled cavity, abscess cavity or spotted cavity should be differentiated from infections, tuberculosis etc. The diagnosis can be proved by sputum examination and/or fiberbronchoscopy.

[X-ray manifestations of atypical peripheral lung cancer--analysis of 100 cases].

The X-ray findings of 100 cases of atypical peripheral lung cancer as compared with those of their pathological specimens are reported. In the chest film, the lesions showed irregular mass shadows, flakes of infiltrations, scattered nodules, rod-like infiltrations, thickened lung markings and thin-walled cavities, etc. These atypical X-ray changes are due to the intermingling of: (1) the site (2) the growth mode (3) the histologic type. For different lesions, even if the histologic type, position and size are the same, the X-ray findings may still be atypical due to the various growth modes. In addition to the recognition of the typical X-ray features, e.g. lobation, spicula, notch, etc, sputum exfoliative cytology, fibrobronchoscopic examination, puncture biopsy of the lung must also be considered in order to ensure early diagnosis.