Interactions between long interpregnancy interval and advanced maternal age on neonatal outcomes.

BACKGROUND: After the implementation of the universal two-child policy in China, it was more frequent to have long interpregnancy intervals (IPIs) and advanced maternal age. However, the interactions between long IPIs and advanced maternal age on neonatal outcomes are unknown. METHODS: The study subjects of this historical cohort study were multiparas with singleton live births between October 1st, 2015, and October 31st, 2020. IPI was defined as the interval between delivery and conception of the subsequent pregnancy. Logistic regression models were used to calculate adjusted odds ratios (aORs) and 95% confidence intervals (CIs) of the risks of preterm birth (PTB), low birth weight (LBW), small for gestation age, and 1-min Apgar score ≤ 7 in different IPI groups. Relative excess risk due to interaction (RERI) was used to evaluate the additive interaction between long IPIs and advanced maternal age. RESULTS: Compared with the 24 ≤ IPI ≤ 59 months group, the long IPI group (IPI ≥ 60 months) was associated with a higher risk of PTB (aOR, 1.27; 95% CI: 1.07-1.50), LBW (aOR, 1.32; 95% CI 1.08-1.61), and one-minute Apgar score ≤ 7 (aOR, 1.46; 95% CI 1.07-1.98). Negative additive interactions (all RERIs < 0) existed between long IPIs and advanced maternal age for these neonatal outcomes. Meanwhile, IPI < 12 months was also associated with PTB (aOR, 1.51; 95% CI 1.13-2.01), LBW (aOR, 1.50; 95% CI 1.09-2.07), and 1-min Apgar score ≤ 7 (aOR, 1.93; 95% CI 1.23-3.04). CONCLUSIONS: Both short and long IPIs are associated with an increased risk of adverse neonatal outcomes. Appropriate IPI should be recommended to women planning to become pregnant again. In addition, better antenatal care might be taken to balance the inferiority of advanced maternal age and to improve neonatal outcomes.

A meta-analysis of fluconazole for the prevention of invasive fungal infection in preterm infants.

OBJECTIVE: The present aimed to evaluate the efficacy and safety of fluconazole for prophylactic use in preterm infants with very low birth weight (VLBW) by using an evidence-based methodology. METHODS: A computerized literature search was conducted in PubMed, the Cochrane Database of Systematic Reviews, MEDLINE, EMBASE, the ISI Web of Knowledge databases, the Chinese Biomedical (CBM) database, China National Knowledge Infrastructure, the WanFang database, and the VIP Chinese science and technology journal database to find all the randomized controlled trials conducted between January 2000 and December 2019 that studied the prevention of invasive fungal infection (IFI) by fluconazole in preterm infants with VLBW. A meta-analysis was conducted using the RevMan 5.3 and GRADEprofiler 3.2.2 software. RESULTS: A total of 14 studies (including 1,930 preterm infants with VLBW) were included. The meta-analysis found that the prophylactic use of fluconazole significantly reduced the incidence of IFI (RR = 0.39; 95% CI: 0.24-0.64, P < 0.05), overall mortality (RR = 0.77; 95% CI: 0.61-0.97, P < 0.05), and fungal colonization rate (RR = 0.32; 95% CI: 0.25-0.41, P < 0.05) in preterm infants with VLBW. There was no significant effect on some common complications and neurological development in preterm infants. The application of fluconazole would not lead to the development of fungal resistance in the short term and would have no significant adverse effects. CONCLUSION: The prophylactic use of fluconazole significantly reduced the incidence of IFI, overall mortality, and fungal colonization in preterm infants; however, the impact of prophylactic use of fluconazole on preterm infants needs to be evaluated in a large number of clinical studies because of the limited data.

[Dynamic observation of pulmonary function by plethysmography in preterm infants with bronchopulmonary dysplasia].

OBJECTIVE: To study the effect of bronchopulmonary dysplasia (BPD) on lung function in preterm infants. METHODS: According to the presence/absence or the severity of BPD, 72 preterm infants were divided into non-BPD group (n=44), mild BPD group (n=15) and moderate BPD group (n=13). Lung function was assessed by plethysmography on days 7, 14 and 28 after birth. RESULTS: The preterm infants in the three groups had gradual increases in tidal volume per kilogram (TV/kg), functional residual capacity (FRC), ratio of time to peak tidal expiratory flow to total expiratory time (%T-PF) and ratio of volume to peak tidal expiratory flow to total expiratory volume (%V-PF) on days 7, 14 and 28 after birth, while there were gradual reductions in effective airway resistance per kilogram (Reff/kg) and respiratory rate (RR) (P<0.05). Compared with the non-BPD group on days 7, 14 and 28 after birth, the mild and moderate BPD groups had significantly lower TV/kg, FRC, %T-PF, and %V-PF and significantly higher Reff/kg and RR (P<0.05). On day 7 after birth, the moderate BPD group had significantly higher airway resistance, Reff/kg and FRC/kg than the mild BPD group (P<0.05). CONCLUSIONS: There is a certain degree of pulmonary function impairment in preterm infants with BPD. Dynamic monitoring of lung function by plethysmography is useful for assessing lung development in the neonatal period in these infants.

[Effect of red blood cell storage duration on the clinical effect of exchange transfusion and internal environment in neonates with hyperbilirubinemia].

OBJECTIVE: To study the effect of red blood cell (RBC) storage duration on the clinical effect of exchange transfusion (ET) and internal environment in neonates with hyperbilirubinemia. METHODS: A retrospective analysis was performed for the clinical data of 135 neonates with hyperbilirubinemia who received ET between January 2015 and August 2018. According to RBC storage duration, the neonates were divided into short-term storage group (RBCs were stored for ≤7 days) with 56 neonates and long-term storage group (RBCs were stored for >7 days) with 79 neonates. The two groups were compared in terms of serum total bilirubin (TBIL) level and the rate of TBIL reduction at 0 and 12 hours after ET, as well as the duration of continued phototherapy and rate of repeated ET. Routine blood test parameters, electrolytes, blood glucose, and blood gas parameters were measured before ET and at 0 hour after ET. RESULTS: At 0 hour after ET, there were no significant differences in the TBIL level and the rate of TBIL reduction between the two groups (P>0.05). At 12 hours after ET, the long-term storage group had a significantly higher TBIL level and a significantly lower rate of TBIL reduction than the short-term storage group (P<0.01). The long-term storage group had a significantly longer duration of continued phototherapy after ET than the short-term storage group (P<0.05). Compared with the short-term storage group, the long-term storage group had significantly higher incidence rates of ET-related complications, including hyponatremia, hyperkalemia, and metabolic acidosis (P<0.05). CONCLUSIONS: The use of RBCs with a storage duration of >7 days in ET for neonates with hyperbilirubinemia does not affect the immediate effect of ET, but these neonates tend to have a poor outcome after continued phototherapy and high risk of hyponatremia, hyperkalemia, and metabolic acidosis.

Risk factors for recurrent macrosomia and child outcomes.

BACKGROUND: Women who had delivered a macrosomic newborn will have a higher risk to deliver another macrosomia. We aimed to examine the recurrence risk of macrosomia in the subsequent pregnancy and the implications in long-term child health. METHODS: Data from the Collaborative Perinatal Project, a longitudinal birth cohort with 54,371 singleton births, were used. 401 recurrent macrosomic infants (macro-macro) and 1327 normal weight babies with a macrosomia in the last pregnancy (macro-normal) were selected to explore risk factors for recurrent macrosomia. Furthermore, 768 newly onset macrosomia with normal birthweight infant in previous pregnancies (normal-macro) were identified to examine long-term health effects of recurrent macrosomia. RESULTS: The recurrent rate of macrosomia was 23.2% [95% confidence interval (CI) 21.2%, 25.2%]. White race, higher pre-pregnant body mass index (BMI), more gestational weight gain, male infant and more prior macrosomic infants were significant risk factors for recurrent macrosomia. At 4 years of age, recurrent macrosomic infants had a higher BMI (16.7 vs. 16.1 kg/m2, adjusted ß: 0.36, 95% CI: 0.12, 0.60) and a higher risk of overweight and obesity (adjusted OR: 1.56, 95% CI: 1.10, 2.23) than infants with normal birthweight after a previous macrosomic sibling. There was no significant difference between recurrent macrosomia and newly onset macrosomia in child outcomes after adjustment for covariates. CONCLUSIONS: Fetal macrosomia has a high recurrence rate in the following pregnancy. Higher maternal pre-pregnant BMI and gestational weight gain are still important risk factors for recurrence of macrosomia, which in turn increases the risk for childhood obesity.

Risk factors for necrotizing enterocolitis in very preterm infants: a case-control study in southwest China.

OBJECTIVE: The objective of this study is to investigate perinatal risk factors for necrotizing enterocolitis (NEC) in very preterm infants. METHODS: This retrospective study included all preterm infants with a gestational age <32 weeks attending our institution from 2013 to 2016. The NEC group comprised patients with NEC enrolled according to the inclusion criteria. Controls were selected from the database and were matched for gender, gestational age, and birth weight. Enumeration data are expressed as percentages (%) and were compared using the χ2 test. Quantitative data are expressed as the mean (standard deviation) and were compared using Student's t-test. Conditional logistic regression analyses were performed to identify the factors significantly associated with NEC. RESULTS: During the study period, 945 very preterm infants were admitted to the neonatal intensive care unit, of whom 46 (4.87%) acquired NEC. A total of 33 cases were enrolled in the NEC group, and 33 controls were selected from the database. Univariate analyses revealed significant differences between groups in the incidence of maternal placenta previa, neonatal infection symptoms, septicemia, and intravenous aminophylline administration (p < .05). Conditional logistic regression analysis demonstrated statistically significant associations of neonatal septicemia (odds ratio [OR] = 4.000, p = .043) and intravenous aminophylline (OR = 4.922, p = .035) with NEC. CONCLUSION: Neonatal septicemia and intravenous aminophylline use are risk factors associated with NEC development in very preterm infants.

Asiaticoside attenuates hyperoxia-induced lung injury in vitro and in vivo.

OBJECTIVES: Asiaticoside (AS) displays anti-inflammation, and anti-apoptosis effect, but the role of AS in hyperoxia-induced lung injury (HILI) treatment is undefined. Therefore, the aim of this study was to investigate the effects of AS on HILI on premature rats and alveolar type II (AEC II) cells. MATERIALS AND METHODS: Sprague-Dawley premature rats (n=25/group) were exposed to 80% O2 with or without AS. Then, we detected 80% O2-induced lung injury and survival rate of premature rat. We tested the concentration of malondialdehyde (MDA), myeloperoxidase (MPO), total antioxidant capacity (TAOC), tumor necrosis factor α (TNF-α), interleukin 6 (IL-6), and interleukin 1ß (IL-1ß) in premature rats' blood. Then, the AEC II cell apoptosis was observed by Hoechst 33258 staining and flow cytometry. Simultaneously, nuclear factor (erythroid-derived 2)-like 2 (Nrf2) signaling pathway was measured by Western blot. RESULTS: Our results found that AS-treated group rats had significantly higher survival rates than 80% O2 group at day 14 (P<0.05). AS protected HILI, decreased the MPO and MDA concentration, and reversed TAOC level (P<0.05). AS also downregulated the levels of TNF-α, IL-1ß, and IL-6 in the premature rat's blood (P<0.01). Moreover, AS markedly attenuated AEC II cell apoptosis and increased Nrf2 and Heme oxygenase 1 (HO-1) expression in the nucleus (P<0.05). CONCLUSION: AS showed protective effects on premature rats of HILI in vitro and in vivo. AS can potentially be developed as a novel agent for the treatment of HILI diseases.

Resveratrol suppresses hyperoxia-induced nucleocytoplasmic shuttling of SIRT1 and ROS production in PBMC from preterm infants in vitro.

OBJECTIVE: By assessing silent mating-type information regulation 2 homolog 1 (SIRT1) nucleocytoplasmic shuttling and reactive oxygen species (ROS) levels in peripheral blood mononuclear cells (PBMCs), this study aimed to explore the role of SIRT1 in premature infants after exposure to hyperoxia and assess the protective effects of resveratrol (Res). METHODS: Firstly, ROS levels as well as SIRT1 translocation and expression in PBMCs samples were evaluated from 40 premature infants with different oxygen amounts received at birth. Then, PBMCs, from additional 40 premature infants administered no oxygen at birth, were used to establish an in vitro model of hyperoxia. RESULTS: In infants that received O2 at birth, ROS and MDA levels, and SIRT1 translocation rates gradually increased in a concentration-dependent manner, while SIRT1 gradually decreased. In agreement, PBMCs cultured in vitro showed increased ROS levels after exposed to hyperoxia, SIRT1 translocation increased as well. However, treatment with Res resulted in opposite effects. CONCLUSION: Res inhibits ROS release in PBMCs from preterm infants exposed to hyperoxia, likely by preventing SIRT1 nucleocytoplasmic shuttling and increasing SIRT1 expression.

[Pathogen distribution, risk factors, and outcomes of nosocomial infection in very premature infants].

OBJECTIVE: To study the pathogen distribution and risk factors of nosocomial infection in very preterm infants, as well as the risk of adverse outcomes. METHODS: A retrospective analysis was performed for the clinical data of 111 very preterm infants who were born between January and December, 2016 and had a gestational age of <32 weeks and a birth weight of <1 500 g. According to the presence or absence of nosocomial infection after 72 hours of hospitalization, the infants were divided into infection group and non-infection group. The infection group was analyzed in terms of pathogenic bacteria which caused infection and their drug sensitivity. A multivariate logistic regression analysis was used to investigate the potential risk factors and risk of adverse outcomes of nosocomial infection in very preterm infants. RESULTS: Gram-negative bacteria were the main pathogens for nosocomial infection in very preterm infants and accounted for 54%, among which Pseudomonas aeruginosa was the most common one; the following pathogens were fungi (41%), among which Candida albicans was the most common one. The drug sensitivity test showed that Gram-negative bacteria were highly resistant to ß-lactam and carbapenems and highly sensitive to quinolones, while fungi had low sensitivity to itraconazole and high sensitivity to 5-fluorocytosine and amphotericin B. Early-onset sepsis, duration of peripherally inserted central catheter, steroid exposure, and duration of parenteral nutrition were risk factors for nosocomial infection in very preterm infants (P<0.05). Compared with the non-infection group, the infection group had significantly higher risks of pulmonary complications (P<0.05), as well as a significantly longer length of hospital stay and a significantly higher hospital cost (P<0.001). CONCLUSIONS: Nosocomial infection in very preterm infants is affected by various factors and may increase the risk of adverse outcomes. In clinical practice, reasonable preventive and treatment measures should be taken with reference to drug sensitivity, in order to improve the prognosis of very premature infants.

Two new species of Tipula (Vestiplex) from Southern China based on morphological and molecular data, with redescription of Tipula (Vestiplex) bicalcarata (Diptera, Tipulidae, Tipulinae).

Two new species of subgenus Tipula (Vestiplex) Bezzi, 1924, Tipula (Vestiplex) leigongshanensis Men & Young, sp. n. and Tipula (Vestiplex) maoershanensis Men & Young, sp. n. are described and illustrated. Tipula (Vestiplex) bicalcarata Savchenko, 1965 is redescribed and illustrated based on additional morphological characters. Partial mitochondrial cytochrome oxidase subunit I (COI) sequences of these three species are provided. Pairwise genetic distances among two new species and related species, Tipula (Vestiplex) bicalcarata, Tipula (Vestiplex) coxitalis Alexander, 1935, and Tipula (Vestiplex) sternotuberculata Alexander, 1935 range from 0.028 to 0.091 using Kimura-2-parameter model. Diagnostic features of the sperm pump for taxonomic use are discussed.

Resveratrol as a potential therapeutic drug for respiratory system diseases.

Respiratory system diseases are common and major ailments that seriously endanger human health. Resveratrol, a polyphenolic phytoalexin, is considered an anti-inflammatory, antioxidant, and anticancer agent. Thanks to its wide range of biological activities, resveratrol has become a hotspot in many fields, including respiratory system diseases. Indeed, research has demonstrated that resveratrol is helpful to relieve pulmonary function in the general population. Meanwhile, growing evidence indicates that resveratrol plays a protective role in respiratory system diseases. This review aimed to summarize the main protective effects of resveratrol in respiratory system diseases, including its anti-inflammatory, antiapoptotic, antioxidant, antifibrotic, antihypertensive, and anticancer activities. We found that resveratrol plays a protective role in the respiratory system through a variety of mechanisms, and so it may become a new drug for the treatment of respiratory system diseases.

Construction of p66Shc gene interfering lentivirus vectors and its effects on alveolar epithelial cells apoptosis induced by hyperoxia.

BACKGROUND: The aim of this study is to observe the inhibitive effects of p66Shc gene interfering lentivirus vectors on the expression of p66Shc, and to explore its effects on alveolar epithelial cells apoptosis induced by hyperoxia. METHODS: The gene sequences were cloned into the pLenR-GPH-shRNA lentiviral vector, which was selected by Genebank searches. The pLenR-GPH-shRNA and lentiviral vector packaging plasmid mix were cotransfected into 293T cells to package lentiviral particles. Culture virus supernatant was harvested, and then the virus titer was determined by serial dilution assay. A549 cells were transduced with the constructed lentiviral vectors, and real-time polymerase chain reaction (RT-PCR) and Western blot were used to evaluate p66Shc expression. This study is divided into a control group, a hyperoxia group, an A549-p66ShcshRNA hyperoxia group, and a negative lentivirus group. Cell apoptosis was detected by flow cytometry after 24 hours; the expression of X-linked inhibitor of apoptosis protein (XIAP) and caspase-9 were detected by immunohistochemistry assay. The production of reactive oxygen species and cellular mitochondria membrane potential (ΔΨm) were determined by fluorescence microscopy. RESULTS: We successfully established the p66Shc gene interfering lentivirus vectors, A549-p66ShcshRNA. The A549-p66ShcshRNA was transfected into alveolar epithelial cells, and the inhibitive effects on the expression of p66Shc were observed. Both RT-PCR and Western blot demonstrated downregulation of p66Shc expression in A549 cells. In the A549-p66ShcshRNA hyperoxia group, we found dampened oxidative stress. A549-p66ShcshRNA can cause p66Shc gene silencing, reduce mitochondrial reactive oxygen species generation, reduce membrane potential decrease, reduce the apoptosis of A549 cells, and reduce alveolar epithelial cell injury, while the lentiviral empty vector group had no such changes. CONCLUSION: p66Shc gene interfering lentivirus vector can affect the alveolar epithelial cells apoptosis induced by hyperoxia.

[Resveratrol increases sirtuin 1 expression in peripheral blood mononuclear cells of premature infants and inhibits the oxidative stress induced by hyperoxia in vivo].

OBJECTIVE: To explore the effect of resveratrol on the levels of sirtuin 1 (SIRT1) and reactive oxygen species (ROS) in peripheral blood mononuclear cells (PBMCs) of premature infants exposed to hyperoxia. METHODS: Peripheral blood and isolated PBMCs from premature infants (gestational age<32 weeks) without oxygen supplement were collected and were randomly assigned into four groups: control, air+resveratrol, hyperoxia, and hyperoxia+resveratrol. The PBMCs were cultured in vitro for 48 hours, then the ROS content in PBMCs was measured by laser scanning confocal microscopy. Malondialdehyde (MDA) content in the medium was measured by the whole spectrum spectrophotometer. SIRT1 positioning was assessed by immunofluorescence. SIRT1 expression levels in PBMCs were measured by Western bolt. RESULTS: Compared with the control group, the level of SIRT1 in the air+resveratrol group increased significantly (P<0.05). The levels of ROS and MDA and the SIRT1 transposition rate in the hyperoxia group increased significantly, while the expression level of SIRT1 decreased significantly compared with the control group (P<0.05). The levels of ROS and MDA and the SIRT1 transposition rate decreased significantly (P<0.05), and the expression level of SIRT1 increased significantly in the hyperoxia+resveratrol group (P<0.05). CONCLUSIONS: Resveratrol can increase SIRT1 expression in PBMCs and inhibit SIRT1 shuttle from nucleus to cytoplasm in order to increase the ability of antioxidative stress in premature infants exposed to hyperoxia, thereby reducing the oxidative stress injury in premature infants.

[Silencing of Pin1 suppresses hyperoxia-induced apoptosis of A549 cells].

OBJECTIVE: To explore the effect of silence of Pin1 expression on hyperoxia-induced apoptosis in alveolar epithelial cells A549. METHODS: A549 cells were divided into four groups: control, hyperoxia, negative lentivirus and Pin1-shRNA hyperoxia. The hyperoxia group was exposed to a mixture of 95%O2 and 5%CO2 for 10 minutes. Then cells were cultured in a closed environment. After 24 hours, the changes of morphology were observed under an inverted microscope. Cell apoptosis was detected by flow cytometry (FCM). The expression of X-linked inhibitor of apoptosis protein (XIAP) and Caspase-9 were detected by immunohistochemistry. The production of reactive oxygen species (ROS) and cellular mitochondria membrane potential (△Ψm) were determined by fluorescence microscopy. RESULTS: Under the inverted microscope, the A549 cells grew slowly and the changes in morphology of the cells were most obvious in the hyperoxia and negative lentivirus groups. The changes in morphology of A549 cells were obviously improved in the Pin1-shRNA hyperoxia group. The FCM results showed that the apoptosis rate of A549 cells increased, Caspase-9 expression increased, XIAP expression decreased, mitochondrial ROS production increased and mitochondrial membrane potential decreased in the hyperoxia and negative lentivirus groups compared with the control group (P<0.05). Compared with the hyperoxia and negative lentivirus groups, the apoptosis rate of A549 cells decreased, Caspase-9 expression decreased, XIAP expression increased, mitochondrial ROS production decreased and mitochondrial membrane potential increased in the Pin1-shRNA hyperoxia group (P<0.05), although the levels of the indexes did not reach to those of the control group. CONCLUSIONS: Silencing of Pin1 could suppress hyperoxia-induced apoptosis of A549 cells.

[Roles of PKCß/P66Shc oxidative stress signal pathway in mediating hyperoxia-induced ROS production in alveolar epithelial cells].

OBJECTIVE: To explore the roles of PKCß/P66Shc oxidative stress signal pathway in mediating hyperoxia-induced reactive oxgen species (ROS) production in alveolar epithelial cells (A549) and the protective effects of PKCß inhibitor on hyperoxia-induced injuries of alveolar epithelial cells. METHODS: A549 cells were cultured in vitro and randomly divided into three groups: control, hyperoxia and PKCß inhibitor LY333531 treatment. The hyperoxia group was exposed to a mixture of O2 (950 mL/L) and CO2 (50 mL/L) for 10 minutes and then cultured in a closed environment. The LY333531 group was treated with PKCß inhibitor LY333531 of 10 µmol/L for 24 hours before hyperoxia induction. Cells were collected 24 hours after culture and the levels of PKCß, Pin1, P66Shc and P66Shc-Ser36 were detected by Western blot. The intracellular translocation of P66Shc, the production of ROS and cellular mitochondria membrane potential were measured using the confocal microscopy. RESULTS: Compared with the control group, the levels of PKCß, Pin1, P66Shc and P-P66Shc-Ser36 in A549 cells 24 hours after culture increased significantly in the hyperoxia group. These changes in the hyperoxia group were accompanied with an increased translocation rate of P66Shc from cytoplasm into mitochondria, an increased production of mitochondrial ROS, and a reduced mitochondrial membrane potential. Compared with the hyperoxia group, the levels of Pin1, P66Shc and P66Shc-Ser36 in A549 cells, the translocation rate of P66Shc from cytoplasm into mitochondria and the production of mitochondrial ROS decreased significantly, while the mitochondrial membrane potential increased significantly in the LY333531 treatment group. However, there were significant differences in the above mentioned measurements between the LY333531 treatment and control groups. CONCLUSIONS: Hyperoxia can increase the expression of PKCß in alveolar epithelial cells and production of mitochondrial ROS and decrease mitochondrial membrane potential. PKCß inhibitor LY333531 can partially disrupt these changes and thus alleviate the hyperoxia-induced alveolar epithelial cell injury.

[Protective effects of mitochondrial ATP-sensitive potassium channel on A549 cell apoptosis induced by hyperoxia].

OBJECTIVE: To explore the protective effects of mitochondrial ATP-sensitive potassium channel opener diazoxide on hyperoxia-induced apoptosis of type II alveolar epithelial cells (A549 cells) and possible mechanisms. METHODS: A549 cells were cultured in vitro and divided randomly into control, hyperoxia and diazoxide group. The hyperoxia group was exposed to a mixture of O2 (900 mL/L) and CO2 (50 mL/L) for 10 minutes, then cultured in a closed environment. The diazoxide group was pretreated with diazoxide of 100 µmol/L for 24 hrs before hyperxia induction. The cells were collected 12, 24 and 48 hrs after culture. The morphologic changes of A549 cells were observed under an inverted microscope. A549 cell apoptosis was detected by flow cytometry. The expression of Omi/HtrA2 in the endochylema of A549 cells was determined by immunohistochemistry. RESULTS: A549 cells were damaged and the changes in morphology of the cells were serious in the hyperoxia group. The apoptosis rate of A549 cells and the expression of Omi/HtrA2 in the endochylema increased in the hyperoxia group compared with the control group (P<0.05). The growth and the morphology of A549 cells were greatly improved and the cell injuries were obviously alleviated in the diazoxide group. The expression of Omi/HtrA2 in the endochylema and the apoptosis rate of A549 cells were significantly reduced in the diazoxide group compared with the hyperoxia group (P<0.05). CONCLUSIONS: Diazoxide as an opener of mitoKATP channel can reduce the expression of Omi/HtrA2 and the apoptosis rate of A549 cells, thus relieves the injury of A549 cells induced by hyperoxia.

[Effects of Ucf-101 on expression of Omi/HtrA2 in kidneys of postasphyxial neonatal rats].

OBJECTIVE: To investigate the expression of serine protease Omi/HtrA2 in kidneys of postasphyxial neonatal rats, and to study the effects of Ucf-101 on apoptosis and the expression of Omi/HtrA2 in these rats. METHODS: Seventy-two neonatal Wistar rats of 7-10 days old were randomly divided into 3 groups: control, postasphyxial model, Ucf-101-treated postasphyxialThe postasphyxial model was established by normobaric asphyxiaExpression of Omi/HtrA2 was determined with streptavidin-peroxidase immunohistochemistry 2, 24 and 48 hrs after asphyxia. Terminal deoxynuleotidyl-mediated nick end labeling (TUNEL) was used to ascertain the apoptosis of renal cells. RESULTS: Compared with the control group, OmiHtrA2 expression in renal cells began to increase 2 hrs after asphyxia and peaked at 24 hrs. The expression of Omi/HtrA2 in the Ucf-101-treated postasphyxial group was significantly lower than that in the postasphyxial model group (P<0.01). TUNEL-positive cells began to increase 2 hrs after asphyxia and peaked at 24 hrs in the postasphyxial model group when compared with the control group. The number of TUNEL-positive cells in the Ucf-101-treated postasphyxial group was significantly lower than that in the postasphyxial model group at all time points (P<0.01). CONCLUSIONS: The expression of Omi/HtrA2 in kidneys is increased in postasphyxial neonatal rats. The increased Omi/HtrA2 expression may play an important role in the development of postasphyxial renal injury. Treatment with Ucf-101 can reduce the expression of Omi/HtrA2 in kidneys of postasphyxial neonatal rats and thus reduce renal tububar epithelial cell apoptosis.

[Influence of diazoxide on mitochondrial apoptosis in human renal tubular cells induced by serum obtained from neonates with asphyxia].

OBJECTIVE: To study the influence of diazoxide on mitochondrial apoptosis pathway of human renal proximal tubular cells (HK-2 cells). METHODS: Cultured HK-2 cells were inoculated on 6-well plates, according to stochastic tables law, and they were divided into normal serum-treated group (NSTG) , post-asphyxial serum treatment group (PSTG), and post-asphyxial serum and diazoxide treatment group (PSDTG). The serum from neonates 24 hours after asphyxia in a dilution of 20% (volume fraction) was used for challenge. Diazoxide in a final concentration of 100 mol/L, was used for intervention. The expression of caspase-3 was detected by immunohistochemical method. The translocation rate of Omi/HtrA2 and mitochondria membrane potential were determined by indirect immunofluorescence and confocal microscopy. RESULTS: Compared with that of NSTG, the expression of caspase-3 absorbance (A) value of HK-2 cells in PSTG was significantly increased (25.19 + or - 3.33 vs. 13.63 + or - 1.89, P<0.01), the translocation rate of Omi/HtrA2 of HK-2 cells in PSTG was significantly increased [(56.01 + or - 5.30)% vs.(37.59 + or - 5.60)%, P<0.01], mitochondrial membrane red/green fluorescence intensity ratio was decreased significantly (0.79 + or - 1.42 vs. 1.82 + or - 0.23, P<0.01). Compared with the PSTG, the expression value of caspase-3 of HK-2 cells in PSDTG was significantly decreased (20.17 + or - 2.19), the translocation rate of Omi/HtrA2 of HK-2 cells in PSDTG was significantly decreased [(46.91 + or - 2.70)%], and mitochondrial membrane red/green fluorescence intensity ratio increased significantly (1.47 + or - 0.14), but did not recover to the same degree as that of the NSTG (all P<0.01). CONCLUSION: The diazoxide may reduce the expression of caspase-3, intracellular translocation of Omi/HtrA2, and stability of mitochondrial membrane potential, thereby significantly alleviates HK-2 cells injury induced by post-asphyxial-serum of neonate.

[Role of Omi/HtrA2 in renal tubular cells apoptosis induced by post asphyxial serum of neonate].

OBJECTIVE: To investigate the mechanism of inducing apoptosis of Omi/HtrA2 in renal tubular cells with post asphyxial serum of neonate. METHODS: Human renal proximal tubular cell line HK-2 cell was used as target cell. They were divided into three groups: control group, asphyxia group and Ucf-101 (Omi/HtrA2 special inhibitor) treated group. The challenge concentration of serum obtained from neonates 24 hours after asphyxia was 20%, and the treatment concentration of Ucf-101 was 10 mumol/L. The Omi/HtrA2 translocation in renal tubular cells was observed with confocal microscopy, and the rate of apoptosis was detected with flow cytometer. RESULTS: It was found that Omi/HtrA2 was translocated into cytoplasm in asphyxia group, and the rate of Omi/HtrA2 translocation in HK-2 cells of asphyxia group was significantly increased [(28.1+/-3.6)% vs. (9.4+/-2.1)%, P<0.01]. Compared with the control group, after being treated with post asphyxial serum, the rate of apoptosis of HK-2 cells in asphyxia group was significantly increased [(36.3+/-4.4)% vs.(12.4+/-2.9)%, P<0.01]. Compared with asphyxia group, the rate of apoptosis in HK-2 cells in Ucf-101 treated group was significantly decreased [(27.0+/-3.9)% vs.(36.3+/-4.4)%, P<0.01]. CONCLUSION: These experimental data demonstrates that post asphyxial serum of neonate can induce apoptosis of HK-2 cells, and translocation of Omi/HtrA2 from mitochondria into cytoplasm may play an important role in its intracellular signal transduction mechanism in induction of apoptosis.