BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off e...BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off ers maximum therapeutic benefi t remains unclear.This study aimed to identify the optimal partial infl ation volume for REBOA.METHODS:In a swine model of hemorrhagic shock,nine healthy female pigs were randomly assigned to three groups based on balloon inflation volume:30%(R30),60%(R60),and 100%(R100)of the volume required to eliminate the contralateral femoral arterial waveform.Hemodynamic variables,fluid and vasopressor requirements,and biochemical markers were evaluated during balloon occlusion and resuscitation following 40%blood volume-controlled hemorrhage.RESULTS:The R30 group showed higher mean arterial pressure during resuscitation and required less fluid and norepinephrine than those of the R100 group.The mean heart rate significantly differed over time among the groups,with more gradual changes in the R30 group.Markers of ischemia-reperfusion injury(lactate,pH,blood urea nitrogen,and creatinine)similarly exhibited significant temporal differences.Post hoc analysis revealed significant pH differences between the groups.The plasma lactate and creatinine levels were significantly lower in the R30 group than those in the other two groups.CONCLUSION:In this swine hemorrhagic shock model,partial REBOA with 30%balloon inflation maintained hemodynamic stability while reducing metabolic derangement compared with higher ballon volumes of 60%and 100%inflation.A strategy involving partial inflation targeting approximately 30%,followed by monitoring the blood pressure trend while using a vasoconstrictor,if necessary,may have potential clinical utility.展开更多
Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT （SHR）, SCARECROW （SCR）, and SCARECROW-LIKE 23 （SCL23）. Recently, it...Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT （SHR）, SCARECROW （SCR）, and SCARECROW-LIKE 23 （SCL23）. Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for spec- ification of the endodermis （known as the bundle sheath） in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein com- plexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feed- back loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morpho- logical analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis （known as the starch sheath） in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.展开更多
In multicellular organisms, controlling the timing and extent of asymmetric cell divisions （ACDs） is crucial for correct patterning. During post-embryonic root development in Arabidopsis thaliana, ground tissue （GT...In multicellular organisms, controlling the timing and extent of asymmetric cell divisions （ACDs） is crucial for correct patterning. During post-embryonic root development in Arabidopsis thaliana, ground tissue （GT） maturation involves an additional ACD of the endodermis, which generates two different tissues： the endo- dermis （inner） and the middle cortex （outer）. It has been reported that the abscisic acid （ABA） and gibberellin （GA） pathways are involved in middle cortex （MC） formation. However, the molecular mechanisms under- lying the interaction between ABA and GA during GT maturation remain largely unknown. Through transcriptome analyses, we identified a previously uncharacterized C2H2-type zinc finger gene, whose expression is regulated by GA and ABA, thus named GAZ （GA- AND ABA-RESPONSIVE ZINC FINGER）. Seedlings ectopically overexpressing GAZ （GAZ-OX） were sensitive to ABA and GA during MC formation, whereas GAZ-SRDX and RNAi seedlings displayed opposite phenotypes. In addition, our results indicated that GAZ was involved in the transcriptional regulation of ABA and GA homeostasis. In agreement with pre- vious studies that ABA and GA coordinate to control the timing of MC formation, we also confirmed the unique interplay between ABA and GA and identified factors and regulatory networks bridging the two hor- mone pathways during GT maturation of the Arabidopsis root.展开更多
基金supported by Seoul National University Hospital(0420210270).
文摘BACKGROUND:Resuscitative endovascular balloon occlusion of the aorta(REBOA)is a minimally invasive technique used to control non-compressible torso hemorrhage.However,the optimal degree of partial occlusion that off ers maximum therapeutic benefi t remains unclear.This study aimed to identify the optimal partial infl ation volume for REBOA.METHODS:In a swine model of hemorrhagic shock,nine healthy female pigs were randomly assigned to three groups based on balloon inflation volume:30%(R30),60%(R60),and 100%(R100)of the volume required to eliminate the contralateral femoral arterial waveform.Hemodynamic variables,fluid and vasopressor requirements,and biochemical markers were evaluated during balloon occlusion and resuscitation following 40%blood volume-controlled hemorrhage.RESULTS:The R30 group showed higher mean arterial pressure during resuscitation and required less fluid and norepinephrine than those of the R100 group.The mean heart rate significantly differed over time among the groups,with more gradual changes in the R30 group.Markers of ischemia-reperfusion injury(lactate,pH,blood urea nitrogen,and creatinine)similarly exhibited significant temporal differences.Post hoc analysis revealed significant pH differences between the groups.The plasma lactate and creatinine levels were significantly lower in the R30 group than those in the other two groups.CONCLUSION:In this swine hemorrhagic shock model,partial REBOA with 30%balloon inflation maintained hemodynamic stability while reducing metabolic derangement compared with higher ballon volumes of 60%and 100%inflation.A strategy involving partial inflation targeting approximately 30%,followed by monitoring the blood pressure trend while using a vasoconstrictor,if necessary,may have potential clinical utility.
文摘Development of the functional endodermis of Arabidopsis thaliana roots is controlled, in part, by GRAS transcription factors, namely SHORT-ROOT （SHR）, SCARECROW （SCR）, and SCARECROW-LIKE 23 （SCL23）. Recently, it has been shown that the SHR-SCR-SCL23 regulatory module is also essential for spec- ification of the endodermis （known as the bundle sheath） in leaves. Nevertheless, compared with what is known about the role of the SHR-SCR-SCL23 regulatory network in roots, the molecular interactions of SHR, SCR, and SCL23 are much less understood in shoots. Here, we show that SHR forms protein com- plexes with SCL23 to regulate transcription of SCL23 in shoots, similar to the regulation mode of SCR expression. Our results indicate that SHR acts as master regulator to directly activate the expression of SCR and SCL23. In the SHR-SCR-SCL23 network, we found a previously uncharacterized negative feed- back loop whereby SCL23 modulates SHR levels. Through molecular, genetic, physiological, and morpho- logical analyses, we also reveal that the SHR-SCR-SCL23 module plays a key role in the formation of the endodermis （known as the starch sheath） in hypocotyls. Taken together, our results provide new insights into the regulatory role of the SHR-SCR-SCL23 network in the endodermis development in both roots and shoots.
文摘In multicellular organisms, controlling the timing and extent of asymmetric cell divisions （ACDs） is crucial for correct patterning. During post-embryonic root development in Arabidopsis thaliana, ground tissue （GT） maturation involves an additional ACD of the endodermis, which generates two different tissues： the endo- dermis （inner） and the middle cortex （outer）. It has been reported that the abscisic acid （ABA） and gibberellin （GA） pathways are involved in middle cortex （MC） formation. However, the molecular mechanisms under- lying the interaction between ABA and GA during GT maturation remain largely unknown. Through transcriptome analyses, we identified a previously uncharacterized C2H2-type zinc finger gene, whose expression is regulated by GA and ABA, thus named GAZ （GA- AND ABA-RESPONSIVE ZINC FINGER）. Seedlings ectopically overexpressing GAZ （GAZ-OX） were sensitive to ABA and GA during MC formation, whereas GAZ-SRDX and RNAi seedlings displayed opposite phenotypes. In addition, our results indicated that GAZ was involved in the transcriptional regulation of ABA and GA homeostasis. In agreement with pre- vious studies that ABA and GA coordinate to control the timing of MC formation, we also confirmed the unique interplay between ABA and GA and identified factors and regulatory networks bridging the two hor- mone pathways during GT maturation of the Arabidopsis root.
