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Lee SH, Li XH, Lu QY, Zhan CL, Kim JD, Lee GH, Sim JM, Cui XS. Nobiletin enhances mitochondrial function by regulating SIRT1/PGC-1α signaling in porcine oocytes during in vitro maturation. Biochem Biophys Res Commun 2024; 706:149747. [PMID: 38479243 DOI: 10.1016/j.bbrc.2024.149747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 02/23/2024] [Accepted: 03/04/2024] [Indexed: 03/24/2024]
Abstract
Nobiletin is a natural flavonoid found in citrus fruits with beneficial effects, including anti-inflammatory, anti-cancer and anti-oxidation effects. The aim of this study was to investigate whether nobiletin improves mitochondrial function in porcine oocytes and examine the underlying mechanism. Oocytes enclosed by cumulus cells were cultured in TCM-199 for 44 h with 0.1% dimethyl sulfoxide (control), or supplemented with 5, 10, 25, and 50 μM of nobiletin (Nob5, Nob10, Nob25, and Nob50, respectively). Oocyte maturation rate was significantly enhanced in Nob10 (70.26 ± 0.45%) compared to the other groups (control: 60.12 ± 0.47%; Nob5: 59.44 ± 1.63%; Nob25: 63.15 ± 1.38%; Nob50: 46.57 ± 1.19%). The addition of nobiletin reduced the levels of reactive oxygen species and increased glutathione levels. Moreover, Nob10 promoted mitochondrial biogenesis by upregulating the protein levels of sirtuin 1 (SIRT1) and peroxisome proliferator-activated receptor-gamma coactivator 1α (PGC-1α). This resulted in an increase in the number of active mitochondria, mitochondrial DNA copy number, mitochondrial membrane potential, and ATP production, thereby enhancing mitochondrial function. The protein level of p53 decreased, followed by the phosphorylation of B-cell lymphoma 2, suggesting a reduction in mitochondria-mediated apoptosis in the Nob10 group. Additionally, the release of cytochrome c from the mitochondria was significantly diminished along with a decrease in the protein expression of caspase 3. Thus, nobiletin has a great potential to promote the in vitro maturation of porcine oocytes by suppressing oxidative stress and promoting mitochondrial function through the upregulation of the SIRT1/PGC-1α signaling pathway.
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Affiliation(s)
- Song-Hee Lee
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Xiao-Han Li
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Qin-Yue Lu
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Cheng-Lin Zhan
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Ji-Dam Kim
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Gyu-Hyun Lee
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Jae-Min Sim
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea
| | - Xiang-Shun Cui
- Department of Animal Science, Chungbuk National University, Cheongju, Chungbuk, 28644, Republic of Korea.
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Min CG, Ma X, Wang YC, Zhong CK, Yuan CS, Zhang KY, Zhan CL, Hou SK, Wang XH, Wang J, Zhao J, Fang Y, Liu HY, Ding H, Guo J, Lu WF. The effects of repeated freezing and thawing on bovine sperm morphometry and function. Cryobiology 2024; 115:104892. [PMID: 38593909 DOI: 10.1016/j.cryobiol.2024.104892] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Revised: 03/14/2024] [Accepted: 04/02/2024] [Indexed: 04/11/2024]
Abstract
Refreezing the remaining genetic resources after in vitro fertilization (IVF) can conserve genetic materials. However, the precise damage inflicted by repeated freezing and thawing on bovine sperm and its underlying mechanism remain largely unexplored. Thus, this study investigates the impact of repeated freeze-thaw cycles on sperm. Our findings indicate that such cycles significantly reduce sperm viability and motility. Furthermore, the integrity of the sperm plasma membrane and acrosome is compromised during this process, exacerbating the advanced apoptosis triggered by oxidative stress. Additionally, transmission electron microscopy exposed severe damage to the plasma membranes of both the sperm head and tail. Notably, the "9 + 2" structure of the tail was disrupted, along with a significant decrease in the level of the axonemal protein DNAH10, leading to reduced sperm motility. IVF outcomes revealed that repeated freeze-thaw cycles considerably impair sperm fertilization capability, ultimately reducing the blastocyst rate. In summary, our research demonstrates that repeated freeze-thaw cycles lead to a decline in sperm viability and motility, attributed to oxidative stress-induced apoptosis and DNAH10-related dynamic deficiency. As a result, the utility of semen is compromised after repeated freezing.
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Affiliation(s)
- Chang-Guo Min
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Xin Ma
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Yu-Chan Wang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Cheng-Kun Zhong
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Chong-Shan Yuan
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Kai-Yan Zhang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Cheng-Lin Zhan
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Sheng-Kui Hou
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Xin-Hai Wang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jun Wang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jing Zhao
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Yi Fang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Hong-Yu Liu
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - He Ding
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jing Guo
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China.
| | - Wen-Fa Lu
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China; Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China; College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China.
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Zhang KY, Guo J, Zhan CL, Yuan CS, Min CG, Li ZQ, Liu HY, Wang J, Zhao J, Lu WF, Ma X. β-hydroxybutyrate impairs bovine oocyte maturation via pyruvate dehydrogenase (PDH) associated energy metabolism abnormality. Front Pharmacol 2023; 14:1243243. [PMID: 37637420 PMCID: PMC10450765 DOI: 10.3389/fphar.2023.1243243] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 08/03/2023] [Indexed: 08/29/2023] Open
Abstract
Background: Ketosis is one of the most frequent and costly metabolic disorders in high-producing dairy cows, and negatively associated with the health and reproductive performance of bovine. Ketosis is mainly caused by the accumulation of ketone body β-hydroxybutyric acid and its diagnosis is based on β-hydroxybutyrate (βHB) concentration in blood. Methods: In this study, we investigated the effects of βHB on bovine oocyte maturation in the concentration of subclinical (1.2 mM) βHB and clinical (3.6 mM). Results: The results showed βHB disrupted bovine oocyte maturation and development capacity. Further analysis showed that βHB induced oxidative stress and mitochondrial dysfunction, as indicated by the increased level of reactive oxygen species (ROS), disrupted mitochondrial structure and distribution, and depolarized membrane potential. Furthermore, oxidative stress triggered early apoptosis, as shown by the enhanced levels of Caspase-3 and Annexin-V. Moreover, 3.6 mM βHB induced the disruption of the pyruvate dehydrogenase (PDH) activity, showing with the decrease of the global acetylation modification and the increase of the abnormal spindle rate. Conclusion: Our study showed that βHB in subclinical/clinical concentration had toxic effects on mitochondrial function and PDH activity, which might affect energy metabolism and epigenetic modification of bovine oocytes and embryos.
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Affiliation(s)
- Kai-Yan Zhang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jing Guo
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Cheng-Lin Zhan
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Chong-Shan Yuan
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Chang-Guo Min
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Zhi-Qiang Li
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Hong-Yu Liu
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jun Wang
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Jing Zhao
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Wen-Fa Lu
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
| | - Xin Ma
- Key Laboratory of the Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun, Jilin, China
- Jilin Provincial International Joint Research Center of Animal Breeding and Reproduction Technology, Jilin Agricultural University, Changchun, Jilin, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun, Jilin, China
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Liu S, Ju AQ, Duan AY, Zhan CL, Gao LP, Ma X, Yang SB. Presence of Ginsenoside Re during in vitro maturation protects porcine oocytes from heat stress. Reprod Domest Anim 2022; 57:1572-1583. [PMID: 36001037 DOI: 10.1111/rda.14234] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Revised: 08/10/2022] [Accepted: 08/20/2022] [Indexed: 11/30/2022]
Abstract
Heat stress (HS) affects the development of porcine gametes and embryos negatively, induces the decrease of reproductive ability significantly, threatens global pig production. Ginsenoside Re (GRe), is a main bioactive component of ginseng, shows very specific anti-apoptotic, antioxidant and anti-inflammatory activities. To investigate the alleviating effect of GRe on the in vitro maturation of porcine oocyte under the HS, the polar body extrusion rate, intracellular levels of reactive oxygen species (ROS) and glutathione (GSH), ATP content, mitochondrial membrane potential (MMP) were assessed. For the current study, porcine cumulus-oocyte complexes (COCs) randomly divided into four groups: the control, GRe, HS and HS+GRe group. The results showed that HS inhibited the cumulus cell expansion and polar body extrusion rate, the levels of GSH and MMP, the ATP content, the gene expression of Nrf2 of porcine oocytes and the parthenogenetic activation (PA) embryo development competence, but GRe treatment could partly neutralize these adverse effects. Moreover, HS increased the ROS formation and percentage of apoptosis, the gene expression of HSP90, CASP3 and CytoC of porcine oocytes, but GRe could weaken the effect on Cyto C and BAX expression induced by HS. Taken together, these results showed that the presence of GRe during in vitro maturation protects porcine oocytes from HS. These findings lay a foundation for GRe may be used as a potential protective drug to protect porcine oocytes against HS damage.
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Affiliation(s)
- Shuang Liu
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - An-Qi Ju
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - Ao-Yi Duan
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - Cheng-Lin Zhan
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - Le-Peng Gao
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - Xin Ma
- College of Animal Science and Technology, Jilin Agricultural University, Jilin, China
| | - Shu-Bao Yang
- Center for Reproductive Medicine, Jilin Medical University, Jilin, China
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Zhang WX, Zhan CL, Geng XC, Mu DW, Yan GD, Chu X. Decreased +gz tolerance following lower body positive pressure: simulated push-pull effect. Aviat Space Environ Med 2001; 72:1045-7. [PMID: 11718510] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
OBJECTIVE The purpose of this study was to attempt to simulate the push-pull maneuver on a single-axis human centrifuge using lower body positive pressure (LBPP), and to observe the effect of the push-pull maneuver on +Gz tolerance. METHODS Six volunteers participated in the experiment. They were subjected to LBPP of up to 300 mm Hg for 1 min. Blood pressure (BP) and heart rate (HR) were monitored before, during and after LBPP. Immediately after LBPP, +Gz tolerance was measured on a human centrifuge. RESULTS During LBPP, systolic BP (SBP) and diastolic BP (DBP) increased significantly, mean arterial pressure (MAP) increased but not significantly, and HR decreased significantly. After LBPP, SBP and MAP decreased significantly, while DBP and HR decreased but not significantly. In all subjects, +Gz tolerance decreased after LBPP. The decreased value was 0.70 +/- 0.06 G, maximum 1.0 G and minimum 0.5 G. CONCLUSION The push-pull maneuver can be simulated on a single-axis human centrifuge using LBPP. The physiologic effects of LBPP were similar to those of -Gz. We observed that +Gz tolerance decreased after LBPP, which confirmed the push-pull effect from the experiment.
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Affiliation(s)
- W X Zhang
- 5th Department, Institute of Aviation Medicine, Air Force, PLA, China.
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Chu X, Geng XC, Zhang WX, Zhan CL, Wang RD, Yan GD. [Data analysis of 492 times centrifuge examination]. Space Med Med Eng (Beijing) 2000; 13:451-5. [PMID: 11767787] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
Objective. To sum up the experiences and to find the regularity of centrifuge examinations. Method. The data of nine years of centrifuge examination (from 1988 to 1996) of pilots who suffered from black out or LOC frequently were analyzed. Result. There were totally 492 times centrifuge examinations. First centrifuge examination included 229 pilots, 49 qualified, 180 unqualified. Second centrifuge examination included 263 pilots, 50 qualified, 213 unqualified. The pilots were all male. The average age of first centrifuge examination was 29.27 +/- 4.87 years. Average flying time was 1015.24 +/- 131.89 h. 68.7% of their plane was JJ-6 or above. Conclusion. Most pilots undergoing centrifuge examination these nine years were 26-35 year old, and had flown for 601-1200 h. The planes they flew are mostly high-performance fighter aircraft. Close attention must be paid to pilots under similar condition by the flight surgeon. It is recommended that the special equipment of G-tolerance training should be added to the fighter aircraft units.
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Affiliation(s)
- X Chu
- Institute of Aviation Medicine, The Air Force, Beijing, China
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Geng XC, Zhan CL, Yan GD, Chu X, Lu X. The protection against +Gz afforded by pressure breathing with different pressure schedules. Space Med Med Eng (Beijing) 2000; 13:166-70. [PMID: 11543476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
OBJECTIVE System of pressure breathing for +Gz (PBG) has been incorporated into service in the high performance fighter aircraft, but there were significant differences among PBG pressure schedules used in different countries. The purpose of this study was to define an optimal pressure schedule in PBG system. METHOD Five male subjects wearing GZ-2 anti-G suit and medium-sized bladder vest, plus PBG with 1.6, 2.4, and 3.2 kPa/G pressure schedules, respectively, were exposed to rapid onset (3.0 G/s) centrifuge +Gz runs. +Gz protection of PBG with each of the three pressure schedules were measured and the subjective ratings were collected. RESULT The +Gz protection afforded by PBG with 1.60, 2.40, and 3.20 kPa/G pressure schedules were 2.00 +/- 0.31, 2.54 +/- 0.32, and 2.44 +/- 0.31 G, respectively. Subjective ratings showed that the PBG with 2.40 kPa/G pressure schedule was better than the other two. CONCLUSION Our data suggest that a PBG pressure schedule of 2.4 kPa/G in PBG system is optimal. It not only assures the anti-G performance of PBG, but also reduces its side effects.
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Affiliation(s)
- X C Geng
- Institute of Aviation Medicine, Air Force of China, Beijing
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Zhang WX, Zhan CL, Geng XC, Lu X, Yan GD, Chu X. Cerebral blood flow velocity by transcranial Doppler during a vertical-rotating table simulation of the push-pull effect. Aviat Space Environ Med 2000; 71:485-8. [PMID: 10801001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
BACKGROUND The push-pull effect (PPE) has been suspected of causing many aircraft accidents. The perfusion and then withdrawal of cerebral blood during the PPE may change the state of the cerebral blood vessel. HYPOTHESIS During head-down tilt (HDT) cerebral vasoconstriction occurs in response to the elevated perfusion pressure to maintain cerebral blood flow, and during subsequent head-up tilt (HUT) the increased resistance of the cerebral blood vessel recovers slowly. METHODS Ten healthy male non-pilots were exposed to the following protocol using a rotating-table to simulate the push-pull maneuver: HUT (+1 Gz) for 1 min followed by transition to HDT (-1 Gz) 10 s followed by transition to HUT (+1 Gz) 1 min. Cerebral blood flow velocity and pulsatility indices in the left middle cerebral artery were continually measured with a transcranial Doppler (TCD) instrument. RESULTS Mean blood flow velocity (Vm) increased significantly by 10%, during the first 5 s of HDT, recovered to baseline during HDT 5 10 s, and remained unchanged during subsequent HUT. Systolic blood flow velocity (Vs) increased by 9% during HDT 5-10 s and 11% during HUT 0-5 s. Diastolic blood flow velocity (Vd) decreased by -9% during HDT 5-10 s, and -22% during HUT 0-5 s. Vs-Vd increased by 26% during HDT 5 10 s, and 41%, during HUT 0-5 s. Pulsatile indices (PI) and resistance index (RI) increased by 26%) and 15% during HDT 5-10 s, and by 40% and 27% during HUT 0-5 s, respectively. Vs, Vs-Vd, PI, and RI remained at the higher level, and Vd remained at the lower level to HDT 15-20 s. CONCLUSIONS The results indicate that cerebral vasoconstriction occurred to prevent brain over-perfusion during HDT. During HUT, the elevated resistance of the cerebral vessel remained at the higher level for about 20 s, and may have worsened the cerebral perfusion from exposure to +Gz. This may be one of the mechanisms of PPE.
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Affiliation(s)
- W X Zhang
- 5th Department, Institute of Aviation Medicine, Air Force, PLA, Beijing, China.
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Zhang WX, Zhan CL, Geng XC, Yan GD, Lu X, Chu X. [Effects of rotating-table simulated "push-pull maneuver" on cerebral circulation function]. Space Med Med Eng (Beijing) 2000; 13:34-7. [PMID: 12214607] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/26/2023]
Abstract
OBJECTIVE To investigate the change and regulation of cerebral circulation during rotating-table simulated push-pull maneuver. METHOD A special rotating-table was used to simulate the push-pull maneuver. 10 healthy adults were subjected to a series of "head-up stand (+1Gz) 1 min head-down stand (-1Gz) 10 s and head-up stand (+1Gz) 1 min" changes. Cerebral blood flow velocity and pulsatility indices in the left middle cerebral artery were constantly measured with a TC2020TCD using Transcranial Doppler [correction of Transcanial Dopplor] instrument. RESULT During 10 s head-down stand (-1Gz) systolic velocity (Vs) increased, diastolic velocity (Vd) decreased, and the pulsatility indices (PI and RI) increased significantly in the left middle cerebral artery. During subsequent head-up stand (+1Gz), these changes didn't resume immediately and maintained for at least 20 s. CONCLUSION This result implied that the push-pull maneuver increased the resistance of the cerebral vessels, which might be one of the mechanisms of the push-pull effect.
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Affiliation(s)
- W X Zhang
- Institute of Aviation Medicine, Air Force, Beijing, China
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Geng XC, Zhan CL, Yan GD, Chu X, Lu X, Zhang WX. [Integrated protection capability afforded by a new type capstan anti-G equipment and anti-G straining maneuver]. Space Med Med Eng (Beijing) 1999; 12:406-9. [PMID: 12432887] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
Abstract
Objective. To investigate the integrated protection capability afforded by a new type capstan anti-G equipment and anti-G straining maneuver, as a result we discussed the feasibility of protection for 8 G 10 s (rapid onset runs at 2 G/s) acceleration using an associated precept with the above both anti-G measures. Method. This study was accomplished using the human centrifuge with rapid onset at 2 G/s. First, we determined the relaxed +Gz tolerance of nine male aviation students, and then determined theirs most + Gz tolerance while thereinto the five aviation students using a new type capstan anti-G suit (NKH) + a new type anti-G valve (NKT) + L-1 anti-G straining maneuver (L-1) and the other four aviation students using a new type capstan counterpressure suit (NDC) + the new type anti-G valve (NKT) + L-1. Result. The most +Gz tolerance of five students was 8.80 +/- 0.27 G while using NKH + NKT + L-1 and was higher than their relaxed +Gz tolerance at 4.60 +/- 0.42 G (P< 0.01) and that the most +Gz tolerance of four students was 8.75 +/- 0.50 G while using NDC + NKT + L-1 and was higher than their relaxed +Gz tolerance at 4.50 +/- 0.46 G (P< 0.01). Conclusion. Pilot will be capable against the 8 G 10 s (rapid onset runs at 2 G/s) effectively using the new type capstan anti +/- G equipment and anti +/- G straining maneuver, and the provided precept has availability.
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Affiliation(s)
- X C Geng
- Institute of Aviation Medicine, Air Force, Beijing, China
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Geng XC, Wang X, Yan GD, Chu X, Zhan CL. [Two high performance fighter pilots with low +Gz tolerance rectified by centrifuge training]. Space Med Med Eng (Beijing) 1999; 12:56-8. [PMID: 11765776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
OBJECTIVE To demonstrate the effects of training on rectifying two high performance fight aircraft pilots with low +Gz tolerance. METHODS Anti-G straining maneuver (AGSM) and pressure breathing for +Gz (PBG) maneuver were trained during centrifuge +Gz stress. RESULTS After training, the +Gz tolerances with AGSM, and with PBG and anti-G suit were enhanced by 3.0 ~ 3.25 G and 2.75 ~ 3.0 G, respectively. The combined +Gz tolerance was higher than the relaxed +Gz tolerance by 4.25 ~ 4.5 G. Both two pilots had passed the 8 G 10 s SACM +Gz profile and reached the standard of training.
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Affiliation(s)
- X C Geng
- Institute of Aviation Medicine, The Air Force, Beijing, China
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Li CJ, Zhan CL. [On the standardization of new chemical risk evaluation with eye irritation test]. Zhonghua Yu Fang Yi Xue Za Zhi 1990; 24:338-40. [PMID: 2099270] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Three new chemicals, N-acyl glutamic acid as a stroma of cosmetics, an eye drops for myopia and 2, 4-dichloro-6-nitrophenylaminate (DCNP) as a new herbicide were evaluated with the eye irritation test. Japanese young rabbits were used, the right eye for test, the left as control. Before and after the test, the eye were stained with 2% sodium fluorescein and examined under slit-lamp microscope to observe the damage degree of cornea, and to record the reaction degree of conjunctiva and iris at the same time. Using the draize method to compare with three kinds of granding (method of bayard and hehir, of EPA and of NRC), the results were essentially the same. The severity of reaction to the eye irritation test is closely related to the kind of testing material and the concentration used and the length of time exposed. The standardization of eye irritation test is also discussed.
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Affiliation(s)
- C J Li
- School of Public Health West China University of Medical Sciences, Chengdu
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Li CJ, Zhan CL, Tang MY, Lu Y, Li GR, Peng XD, Li HY, Wu ZS, Zeng XM. [Optical and ultrastructural changes in the rabbit lens caused by microwaves]. Hua Xi Yi Ke Da Xue Xue Bao 1988; 19:200-3. [PMID: 3198105] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
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Liu YF, Xiao BL, Li SQ, Zhan CL. [Comparative study of enzyme histochemistry and two other indexes in toxicity experiments with isolated rat hepatocytes]. Hua Xi Yi Ke Da Xue Xue Bao 1986; 17:306-9. [PMID: 3570266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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15
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Cheng TJ, Dong QA, Xiao BL, Li SQ, Zhan CL. [Experimental study on liver injury by chlorobutadiene]. Hua Xi Yi Ke Da Xue Xue Bao 1986; 17:216-9. [PMID: 3557426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
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