BACKGROUND:Adipose-derived stem cells have anti-aging effects,but whether adipose-derived stem cells from donors of different ages are different needs further study. OBJECTIVE:To compare the biological properties of adipose-derived stem cells in old and young mice. METHODS:Adipose-derived stem cells were extracted from adipose tissue of C57BL mice aged 8 and 14 weeks,respectively.The differences of cell cycle,apoptosis,and proliferation of adipose-derived stem cells in old and young mice were compared.The expression levels of aging-related P21 and P27 genes and proteins of adipose-derived stem cells in old and young mice were detected by quantitative PCR and western blot assay. RESULTS AND CONCLUSION:Compared with old mouse adipose-derived stem cells,young mouse adipose-derived stem cells were more active,more regular in morphology,less apoptosis,faster proliferation,and lower in expression of age-related P21 and P27 genes and proteins.It has been proven that adipose-derived stem cells from young mice have better anti-aging effects.

Objective:To design and develop a cone-beam CT imaging system for small animals with continuously adjustable spatial resolution.Methods:The imaging system used an X-ray source with a focal spot size of 30 μm and a flat panel detector with a pixel size of 100 μm. On this premise, a " stepping-focusing-rotating" image acquisition mode was proposed, in which the " focusing" and " stepping" systems were sequentially embedded in the " rotating" system. In this acquisition mode, the X-ray source and flat panel detector were relatively stationary to form the " focusing" system. When the " stepping" system accurately transported the object to the scanning position, the " focusing" system could achieve adjustable spatial resolution by making linear motion around the object to be scanned according to different experimental requirements. Finally the " rotating" system achieve high-quality imaging.Results:The variable spatial resolution of small animal CBCT ranges from 35.7 μm to 71.4 μm, and the FOV ranges from 39.6 mm to 108.0 mm. The conversion time for the limit spatial resolution is 19.125 s, which allowed accurate 3D reconstruction of normal mice at different resolutions with high reproducibility.Conclusions:A cone-beam CT suitable for small animals has been developed, whose spatial resolution and FOV can be adjusted arbitrarily within a certain range, which can meet the different imaging requirements in rodent experiments.

Xenotransplantation is an important approach to addressing the shortage of donor organs. However, it still faces numerous challenges, such as acute rejection and zoonotic diseases. Organoid-on-a-chip technology refers to a microcell culture device that simulates the physiological functions of human organs in vitro. In recent years, it has achieved a series of important results in the field of allotransplantation and has great application prospects in the field of xenotransplantation, bringing new opportunities for xenotransplantation research. Therefore, this article discusses the current research status and progress of organoid-on-a-chip technology, combined with the various problems faced by xenotransplantation, to explore the application of organoid-on-a-chip technology in solving the selection of immunosuppressive regimens, matching and viral reactivation in xenotransplantation. This aims to open up new avenues for solving the current problems in the field of xenotransplantation and promote its further development.

Objective:To design and develop a cone-beam CT imaging system for small animals with continuously adjustable spatial resolution.Methods:The imaging system used an X-ray source with a focal spot size of 30 μm and a flat panel detector with a pixel size of 100 μm. On this premise, a " stepping-focusing-rotating" image acquisition mode was proposed, in which the " focusing" and " stepping" systems were sequentially embedded in the " rotating" system. In this acquisition mode, the X-ray source and flat panel detector were relatively stationary to form the " focusing" system. When the " stepping" system accurately transported the object to the scanning position, the " focusing" system could achieve adjustable spatial resolution by making linear motion around the object to be scanned according to different experimental requirements. Finally the " rotating" system achieve high-quality imaging.Results:The variable spatial resolution of small animal CBCT ranges from 35.7 μm to 71.4 μm, and the FOV ranges from 39.6 mm to 108.0 mm. The conversion time for the limit spatial resolution is 19.125 s, which allowed accurate 3D reconstruction of normal mice at different resolutions with high reproducibility.Conclusions:A cone-beam CT suitable for small animals has been developed, whose spatial resolution and FOV can be adjusted arbitrarily within a certain range, which can meet the different imaging requirements in rodent experiments.

BACKGROUND:As an emerging treatment method,stem cell therapy is expected to improve the ovarian environment,delays the aging of ovarian granulosa cells,and brings new hope to older pregnant women.OBJECTIVE:To review the mechanism and research progress of stem cells against ovarian granulosa cell senescence.METHODS:CNKI and PubMed databases were retrieved for articles on stem cell therapy for ovarian granulosa cell senescence.Chinese and English search terms were"stem cells,ovary granulosa cells,aging."Finally,67 articles were included for analysis.RESULTS AND CONCLUSION:(1)This review summarizes five mechanisms of ovarian granulosa cell senescence:DNA damage and decreased repair capacity,oxidative stress,impaired mitochondrial function,inflammatory response,and changes in hormone levels.(2)This article summarizes five main mechanisms of stem cells in the treatment of ovarian granulosa cell senescence:promoting proliferation and inhibiting apoptosis,differentiation potential and regeneration ability,secreting factors,anti-oxidation,anti-inflammatory response,and immune regulation.(3)At present,there are various types of stem cells that can cooperate to treat ovarian granulosa cell senescence through a variety of ways,and stem cell therapy has broad prospects in restoring female fertility.

BACKGROUND:With the increase of age,the function of bone marrow-derived mesenchymal stem cells is gradually reduced,and delaying the aging of bone marrow-derived mesenchymal stem cells itself has become an important topic.OBJECTIVE:To explore ways to delay the aging of bone marrow-derived mesenchymal stem cells by changing the expression of telomerase Cajal body protein 1(TCAB1)gene.METHODS:Mouse bone marrow-derived mesenchymal stem cells were cultured by cell adhesion method.TCAB1 gene in bone marrow-derived mesenchymal stem cells was overexpressed and interfered by recombinant lentivirus technique.The expression of aging related genes P16,P21,P53,and P27 was detected by qPCR.The relative length of telomeres was detected by qPCR.The expression of aging proteins P16,P21,P53,and P27 was detected by western blot assay.Cell proliferation was detected by CCK-8 assay.Annexin V-PE/7-AAD apoptosis kit was used to detect the degree of cell apoptosis.RESULTS AND CONCLUSION:Bone marrow-derived mesenchymal stem cell lines overexpressing TCAB1 gene had decreased expression of senescence related genes and proteins,increased Telomere relative length,stronger cell proliferation,less apoptosis,and a youthful state.The expression of age-related genes and proteins in bone marrow mesenchymal stem cells interfering with TCAB1 gene increased,and the relative telomere length decreased;cell proliferation ability was weak;cell apoptosis was more,and cells showed senescence.These results indicate that increasing the expression of TCAB1 in an appropriate range can delay the rate of cell senescence.

BACKGROUND:As an emerging treatment method,stem cell therapy is expected to improve the ovarian environment,delays the aging of ovarian granulosa cells,and brings new hope to older pregnant women.OBJECTIVE:To review the mechanism and research progress of stem cells against ovarian granulosa cell senescence.METHODS:CNKI and PubMed databases were retrieved for articles on stem cell therapy for ovarian granulosa cell senescence.Chinese and English search terms were"stem cells,ovary granulosa cells,aging."Finally,67 articles were included for analysis.RESULTS AND CONCLUSION:(1)This review summarizes five mechanisms of ovarian granulosa cell senescence:DNA damage and decreased repair capacity,oxidative stress,impaired mitochondrial function,inflammatory response,and changes in hormone levels.(2)This article summarizes five main mechanisms of stem cells in the treatment of ovarian granulosa cell senescence:promoting proliferation and inhibiting apoptosis,differentiation potential and regeneration ability,secreting factors,anti-oxidation,anti-inflammatory response,and immune regulation.(3)At present,there are various types of stem cells that can cooperate to treat ovarian granulosa cell senescence through a variety of ways,and stem cell therapy has broad prospects in restoring female fertility.

BACKGROUND:With the increase of age,the function of bone marrow-derived mesenchymal stem cells is gradually reduced,and delaying the aging of bone marrow-derived mesenchymal stem cells itself has become an important topic.OBJECTIVE:To explore ways to delay the aging of bone marrow-derived mesenchymal stem cells by changing the expression of telomerase Cajal body protein 1(TCAB1)gene.METHODS:Mouse bone marrow-derived mesenchymal stem cells were cultured by cell adhesion method.TCAB1 gene in bone marrow-derived mesenchymal stem cells was overexpressed and interfered by recombinant lentivirus technique.The expression of aging related genes P16,P21,P53,and P27 was detected by qPCR.The relative length of telomeres was detected by qPCR.The expression of aging proteins P16,P21,P53,and P27 was detected by western blot assay.Cell proliferation was detected by CCK-8 assay.Annexin V-PE/7-AAD apoptosis kit was used to detect the degree of cell apoptosis.RESULTS AND CONCLUSION:Bone marrow-derived mesenchymal stem cell lines overexpressing TCAB1 gene had decreased expression of senescence related genes and proteins,increased Telomere relative length,stronger cell proliferation,less apoptosis,and a youthful state.The expression of age-related genes and proteins in bone marrow mesenchymal stem cells interfering with TCAB1 gene increased,and the relative telomere length decreased;cell proliferation ability was weak;cell apoptosis was more,and cells showed senescence.These results indicate that increasing the expression of TCAB1 in an appropriate range can delay the rate of cell senescence.

Betacoronavirus ; Coronavirus Infections ; Humans ; Pandemics ; Pneumonia, Viral ; Single-Cell Analysis

Objective:To evaluate the efficacy and safety of lopinavir/ritonavir (LPV/r) and arbidol in treating patients with coronavirus disease 2019 (COVID-19) in the real world.Methods:The clinical data of 178 patients diagnosed with COVID-19 admitted to Guangzhou Eighth People′s Hospital from January 20 to February 10, 2020 were retrospectively analyzed. According to patient′s antiviral treatment regimens, 178 patients were divided into 4 groups including LPV/r group (59 patients), arbidol group (36 patients), LPV/r plus arbidol combination group (25 patients) and the supportive care group without any antiviral treatment (58 patients). The primary end point was the negative conversion time of nucleic acid of 2019 novel coronavirus (2019-nCoV) by pharyngeal swab.Results:The baseline parameters of 4 groups before treatment was comparable. The negative conversion time of viral nucleic acid was (10.20±3.49), (10.11±4.68), (10.86±4.74), (8.44±3.51) days in LPV/r group, arbidol group, combination group, and supportive care group respectively ( F=2.556, P=0.058). There was also no significant difference in negative conversion rate of 2019-nCoV nucleic acid, the improvement of clinical symptoms, and the improvement of pulmonary infections by CT scan ( P>0.05). However, a statistically significant difference was found in the changing rates from mild/moderate to severe/critical type at day 7 (χ 2=9.311, P=0.017), which were 24%(6/25) in combination group, 16.7%(6/36) in arbidol group, 5.4%(3/56) in LPV/r group and 5.2%(3/58) in supportive care group. Moreover, the incidence of adverse reactions in three antiviral groups was significantly higher than that in supportive care group (χ 2=14.875, P=0.002). Conclusions:Antiviral treatment including LPV/r or arbidol or combination does not shorten the negative conversion time of 2019-nCoV nucleic acid nor improve clinical symptoms. Moreover, these antiviral drugs cause more adverse reactions which should be paid careful attention during the treatment.