早产儿超声心脏几何形态学与血流动力学的相关性分析

摘要 目的：探讨与分析早产儿超声心脏几何形态学与血流动力学的相关性。方法：研究时间为2018年8月到2020年6月,选择本院收治的早产儿150例(早产组)和足月儿150例(足月组)作为研究对象,两组新生儿都给予超声检查,记录、左心室舒张期内径(Left ventricular diastolic diameter,LVDd)、左心室收缩期内径(Left ventricular systolic diastolic,LVDs)、左房内径(Left atrial diameter,LAD)、左心室相对厚度(Left ventricular relative wall thickness,LVRWT)、左心室心肌质量(Left ventricular myocardial mass,LVM)、左室后壁舒张期厚度(Left ventricular posterior walldepth,LVPWd)、左心室舒张末期容积(Left ventricular end diastolic volume,LVDV)、左心室收缩末期容积(Left ventricular end systolic volume,LVSV)、每搏输出量(Stroke volume,SV)、左心室射血分数(Left ventricular ejection fraction,LVEF)、左心室缩短分数(Left ventricular fractional shortening,LVFS)等指标并进行相关性分析。结果：早产组的LVDd、LVDs、LAD、LVPWd、LVRWT、LVM值都显著低于足月组(P<0.05)。早产组的LVDV、LVSV、SV值低于足月组(P<0.05),两组LVEF、LVFS值对比差异无统计学意义(P>0.05)。在早产组中,Pearson相关性分析显示LVDd、LVDs、LAD、LVPWd、LVRWT、LVM值与LVDV、LVSV、SV值存在正相关性(P<0.05)。Cox比例风险回归模型显示早产儿的出生体重、身长为影响LVDd、LVDV值的主要因素(P<0.05)。结论：早产儿超声心脏几何形态学指标与血流动力学指标呈正相关,提示超声能准确记录和监测早产儿的心脏几何形态学与血流动力学,可作为评估早产儿心功能的一种可靠方法。     

骨髓问充质干细胞移植对VCD所致卵巢损伤的修复研究

目的：探讨小鼠骨髓间充质干细胞（MSCs）移植对去氧乙烯基环己烯（VCD）所致卵巢早衰治疗的可行性。方法：采用VCD（160mgkg^-l,day^-1）连续腹腔注射来诱导小鼠卵巢早衰。每侧卵巢注射转染了绿色荧光基因小鼠骨髓来源的MSCs,于移植后14、28天及45天,取各组血液标本及卵巢组织,同时观察小鼠动情周期的变化;酶联免疫法检测血清FSH、LH水平,显微镜下观察MSC在卵巢的分布。结果：MSCs移植后各组均可见绿色荧光,并且主要分布于卵巢间质区,卵巢泡膜细胞区也可见绿色荧光细胞。MSCs组动情周期较实验对照组缩短,FSH与LH水平较实验对照组低,差异具有显著性。结论：骨髓间充质干细胞可改善卵巢早衰小鼠的卵巢内分泌功能,并且长时间存在于卵巢组织。骨髓间充质干细胞可能成为卵巢早衰治疗的新方法。     

早期干预对早产儿脑损伤预后的临床观察

目的:探讨早期联合干预对脑损伤早产儿智能及运动发育的影响。方法:80例存在脑损伤的早产儿随机分为干预组与对照组,每组各40例,对照组给予常规治疗与保健指导,干预组在此基础上联合神经节苷脂治疗与早期康复训练,定期随访两年,观察比较患儿纠正胎龄40周时神经行为评分(NBNA),智力及运动发育情况。结果:干预组患儿纠正胎龄40周NBNA评分为33.04±1.12,对照组NBNA评分为30.95±0.88,两组间差异有统计学意义(P<0.05);干预组MDI与PDI指数分别于9月龄始和6月龄始显著高于对照组(P<0.01或0.05);1岁时进行Gesell智力发育检查,干预组大运动、精细动作、适应性、语言、个人-社会交往等五个能区情况均明显好于对照组(P<0.01);干预组17.5%的后遗症发生率显著低于对照组32.5%的发生率(P<0.01)。结论:联合早期干预治疗可有效促进脑损伤早产儿神经系统功能修复,改善智能及运动发育,减少后遗症发生。     

生物蛋白胶封堵合并宫颈环扎术治疗胎膜早破的疗效观察

目的:观察生物蛋白胶封堵合并宫颈环扎术治疗胎膜早破,对孕妇、胎儿及新生儿的影响,明确该技术治疗胎膜早破的疗效。方法:我院产科共收治妊娠<30周胎膜早破患者48例,采用生物蛋白胶封堵合并宫颈环扎术治疗胎膜早破,观察治疗后孕妇羊水指数,胎儿双顶径,新生儿出生时体重,及孕妇的副反应。结果:在本次封堵治疗过程中均一次封堵成功,没有不良反应发生,所有孕妇术后阴道流水情况均明显改善,其中有2例孕妇术后1周阴道流水停止。所有孕妇术后羊水漏出量均明显减少,B超检查显示羊水指数均在(6±2)cm,胎儿每周双顶径增长均达到(0.15±0.02)cm,延长孕周最短(5±2)w,10例早产,38例继续妊娠至37 w。新生儿出生时体重为(2000±260)g,无1例发生NRDS。同期没有进行宫颈内封堵仅行药物保胎治疗的10例孕妇,胎龄延长最长达到10 d,最短者24 h内出现早产分娩,早产儿平均体重1400 g,均发生NRDS,有2例放弃治疗,4例在NICU行治疗,最终因各种并发症死亡。48例行封堵治疗孕妇未发生过敏反应,无阴道出血及产后出血和感染等。结论:应用生物蛋白胶结合宫颈环扎术治疗胎膜早破,手术操作简单,可延长了孕周,提高了新生儿成活率,无不良反应,具有广泛的应用前景。     

Testing the faux-UTR model for NMD: analysis of Upf1p and Pab1p competition for binding to eRF3/Sup35p

Nonsense-mediated mRNA decay (NMD) is a surveillance mechanism that accelerates the degradation of mRNAs containing premature translation termination codons. This quality control pathway depends on the NMD-specific factors, Upf1p, Upf2p/Nmd2p, and Upf3p, as well as the two release factors, eRF1 and eRF3 (respectively designated Sup45p and Sup35p in yeast). NMD activation is also enabled by the absence of the poly(A)-binding protein, Pab1p, downstream of a termination event. Since Sup35p interacts with both Upf1p and Pab1p we considered the possibility that differential binding of the latter factors to Sup35p may be a critical determinant of NMD sensitivity for an mRNA. Here we describe three approaches to assess this hypothesis. First, we tethered fragments or mutant forms of Sup35p downstream of a premature termination codon in a mini-pgk1 nonsense-containing mRNA and showed that the inhibition of NMD by tethered Sup35p does not depend on the domain necessary for the recruitment of Pab1p. Second, we examined the Sup35p interaction properties of Upf1p and Pab1p in vitro and showed that these two proteins bind differentially to Sup35p. Finally, we examined competitive binding between the three proteins and observed that Upf1p inhibits Pab1p binding to Sup35p whereas the interaction between Upf1p and Sup35p is relatively unaffected by Pab1p. These data indicate that the binding of Upf1p and Pab1p to Sup35p may be more complex than anticipated and that NMD activation could involve more than just simple competition between these factors. We conclude that activation of NMD at a premature termination codon is not solely based on the absence of Pab1p and suggest that a specific recruitment step must commit Upf1p to the process and Upf1p-associated mRNAs to NMD.     

Copper,zinc and iron levels in premature infants following red blood cell transfusion

This study aimed to investigate effect of erythrocyte suspension (ES) transfusion on Cu, Zn, and Fe levels. It was conducted on 53 premature infants who were admitted to Hacettepe Hospital and received EST for first time. Blood samples were drawn before and 96 h after ES transfusion to determine Cu, Zn, and Fe levels in plasma and/or erythrocytes. The mean plasma Cu levels were 99 ± 3 μg/dl and 113 ± 3 μg/dl; Zn levels were 105 ± 2 μg/dl and 115 ± 23 μg/dl; mean plasma Fe level was 58.1 ± 19.4 and 75.2 ± 25.4 μg/dl and mean erythrocyte Fe level was 4182 ± 2314 μg/ml and 7009 ± 5228 μg/ml, before and after ES transfusion. The differences between before and after ES transfusion in Cu, Zn and Fe levels were significant. Correlation between plasma and erythrocyte Fe levels was significant both before and after ES transfusion. Though Fe overload is a major cause of morbidity/mortality after ES transfusion, alterations in trace elements should also be considered when transfusing blood to infants and children.     

Premature Stop Codon at Residue 101 within HIV-1 Rev Does Not Influence Viral Replication of Clade BC but Severely Reduces Viral Fitness of Clade B

HIV-1 Rev is an accessory protein that plays a key role in nuclear exportation, stabilization, and translation of the viral mRNAs. Rev of HIV-1 clade BC often shows a truncation of 16 AAs due to a premature stop codon at residue 101. This stop codon presents the highest frequency in clade BC and the lowest frequency in clade B. In order to discover the potential biological effect of this truncation on Rev activity and virus replication of clade BC, we constructed Rev expression vectors of clade BC with or without 16 AAs within C-terminal separately, and replaced the stop codon by Q in a CRF07_BC infectious clone. We found that 16 AAs truncation had no effect on expression and activity of Rev in clade BC.Also, the mutation from the stop codon to Q had no effect on virus replication of clade BC. Next, to investigate the effect of this truncation on Rev activity and replication capacity of clade B, Rev expression vectors of clade B carrying or lacking 16 AAs in C-terminal were constructed respectively, and residue Q at position 101 within Rev was substituted by the stop codon in a clade B infectious clone. It was found that 16 AAs truncation significantly down-regulated Rev expression and impaired clade B Rev activity. Furthermore, a Q-to-stop codon substitution within Rev significantly reduced viral replication fitness of clade B. These results indicate that the premature stop codon at residue 101 within Rev exerts diverse impact on viral replication among different HIV-1 clades.     

Examining tissue composition,whole-bone morphology and mechanical behavior of GorabPrx1 mice tibiae: A mouse model of premature aging

Gerodermia osteodysplastica (GO) is a segmental progeroid disorder caused by loss-of-function mutations in the GORAB gene, associated with early onset osteoporosis and bone fragility. A conditional mouse model of GO (Gorab^Prx1) was generated in which the Gorab gene was deleted in long bones. We examined the biomechanical/functional relevance of the Gorab^Prx1 mutants as a premature aging model by characterizing bone composition, tissue-level strains, and whole-bone morphology and mechanical properties of the tibia. MicroCT imaging showed that Gorab^Prx1 tibiae had an increased anterior convex curvature and decreased cortical cross-sectional area, cortical thickness and moments of inertia, compared to littermate control (LC) tibiae. Fourier transform infrared (FTIR) imaging indicated a 34% decrease in mineral/matrix ratio and a 27% increase in acid phosphate content in the posterior metaphyseal cortex of the Gorab^Prx1 tibiae (p < .05), suggesting delayed mineralization. In vivo strain gauge measurement and finite element analysis showed ∼two times higher tissue-level strains within the Gorab^Prx1 tibiae relative to LC tibiae when subjected to axial compressive loads of the same magnitude. Three-point bending tests suggested that Gorab^Prx1 tibiae were weaker and more brittle, as indicated by decreasing whole-bone strength (46%), stiffness (55%), work-to-fracture (61%) and post-yield displacement (47%). Many of these morphological and biomechanical characteristics of the Gorab^Prx1 tibia recapitulated changes in other animal models of skeletal aging. Future studies are necessary to confirm how our observations might guide the way to a better understanding and treatment of GO.     

枸橼酸咖啡因联合加温湿化高流量鼻导管通气对呼吸窘迫综合征早产儿神经发育和血清BMP-7、CC16的影响

摘要 目的：观察枸橼酸咖啡因联合加温湿化高流量鼻导管通气（HHHFNC）对呼吸窘迫综合征（RDS）早产儿神经发育和血清骨形态发生蛋白-7（BMP-7）、Clara细胞分泌蛋白（CC16）的影响。方法：纳入2019年3月~2021年3月期间我院新生儿重症监护室收治的RDS早产儿93例,通过随机数字表法将患儿分为对照组[接受鼻持续气道正压通气 (NCPAP)治疗]和实验组（接受枸橼酸咖啡因联合HHHFNC治疗）,例数分别为46例、47例。对比两组患儿无创辅助通气时间、总用氧时间、撤机失败率、血气分析指标、神经发育指标、BMP-7、CC16水平和并发症情况。结果：实验组的无创辅助通气时间、总用氧时间短于对照组,撤机失败率低于对照组（P<0.05）。两组治疗24 h后pH值组间对比无统计学差异（P>0.05）,实验组治疗24 h后血氧分压（PaO₂）高于对照组,二氧化碳分压（PaCO₂）低于对照组（P<0.05）。实验组治疗结束后精神运动发育指数（PDI）、智力发展指数（MDI）高于对照组,血清β-内啡肽（β-EP）水平低于对照组（P<0.05）。实验组治疗结束后血清BMP-7、CC16水平低于对照组（P<0.05）。两组患儿并发症发生率组间对比无统计学差异（P>0.05）。结论：枸橼酸咖啡因联合HHHFNC治疗早产儿RDS可缩短无创辅助通气时间,提高撤机成功率,促进氧合恢复,同时还可改善血清BMP-7、CC16水平,促进患儿神经发育。