HISTONE DEACETYLASE19 Controls Ovule Number Determination and Transmitting Tract Differentiation

The gynoecium is critical for the reproduction of flowering plants as it contains the ovules and the tissues that foster pollen germination, growth, and guidance. These tissues, known as the reproductive tract (ReT), comprise the stigma, style, and transmitting tract (TT). The ReT and ovules originate from the carpel margin meristem (CMM) within the pistil. SHOOT MERISTEMLESS (STM) is a key transcription factor for meristem formation and maintenance. In all above-ground meristems, including the CMM, local STM downregulation is required for organ formation. However, how this downregulation is achieved in the CMM is unknown. Here, we have studied the role of HISTONE DEACETYLASE 19 (HDA19) in Arabidopsis (Arabidopsis thaliana) during ovule and ReT differentiation based on the observation that the hda19-3 mutant displays a reduced ovule number and fails to differentiate the TT properly. Fluorescence-activated cell sorting coupled with RNA-sequencing revealed that in the CMM of hda19-3 mutants, genes promoting organ development are downregulated while meristematic markers, including STM, are upregulated. HDA19 was essential to downregulate STM in the CMM, thereby allowing ovule formation and TT differentiation. STM is ectopically expressed in hda19-3 at intermediate stages of pistil development, and its downregulation by RNA interference alleviated the hda19-3 phenotype. Chromatin immunoprecipitation assays indicated that STM is a direct target of HDA19 during pistil development and that the transcription factor SEEDSTICK is also required to regulate STM via histone acetylation. Thus, we identified factors required for the downregulation of STM in the CMM, which is necessary for organogenesis and tissue differentiation.

Assessing the role of REM13, REM34 and REM46 during the transition to the reproductive phase in Arabidopsis thaliana

REM (reproductive meristem) transcription factors have been proposed as regulators of plant reproductive development mainly based on their specific expression patterns in reproductive structures, but their roles are still largely unknown probably because of their redundancy. We selected three REM genes (REM13, REM34 and REM46) for functional analysis, based on their genome position and/or co-expression data.Our results suggest that these genes have a role in flowering time regulation and may modulate cell cycle progression. In addition, protein interaction experiments revealed that REM34 and REM46 interact with each other, suggesting that they might work cooperatively to regulate cell division during inflorescence meristem commitment.Previous attempts of using co-expression data as a guide for functional analysis of REMs were limited by the transcriptomic data available at the time. Our results uncover previously unknown functions of three members of the REM family of Arabidopsis thaliana and open the door to more comprehensive studies of the REM family, where the combination of co-expression analysis followed by functional studies might contribute to uncovering the biological roles of these proteins and the relationship among them.

Secondary use of data extracted from a clinical information system to assess the adherence of tidal volume and its impact on outcomes

OBJECTIVES

To extract data from clinical information systems to automatically calculate high-resolution quality indicators to assess adherence to recommendations for low tidal volume.

DESIGN

We devised two indicators: the percentage of time under mechanical ventilation with excessive tidal volume (>8mL/kg predicted body weight) and the percentage of patients who received appropriate tidal volume (≤8mL/kg PBW) at least 80% of the time under mechanical ventilation. We developed an algorithm to automatically calculate these indicators from clinical information system data and analyzed associations between them and patients' characteristics and outcomes.

SETTINGS

This study has been carried out in our 30-bed polyvalent intensive care unit between January 1, 2014 and November 30, 2019.

PATIENTS

All patients admitted to intensive care unit ventilated >72h were included.

INTERVENTION

Use data collected automatically from the clinical information systems to assess adherence to tidal volume recommendations and its outcomes.

MAIN VARIABLES OF INTEREST

Mechanical ventilation days, ICU length of stay and mortality.

RESULTS

Of all admitted patients, 340 met the inclusion criteria. Median percentage of time under mechanical ventilation with excessive tidal volume was 70% (23%-93%); only 22.3% of patients received appropriate tidal volume at least 80% of the time. Receiving appropriate tidal volume was associated with shorter duration of mechanical ventilation and intensive care unit stay. Patients receiving appropriate tidal volume were mostly male, younger, taller, and less severely ill. Adjusted intensive care unit mortality did not differ according to percentage of time with excessive tidal volume or to receiving appropriate tidal volume at least 80% of the time.

CONCLUSIONS

Automatic calculation of process-of-care indicators from clinical information systems high-resolution data can provide an accurate and continuous measure of adherence to recommendations. Adherence to tidal volume recommendations was associated with shorter duration of mechanical ventilation and intensive care unit stay.

Awareness and use of mouthguards in risk sports by Spanish children between 6 and 18 years of age

AIM

To investigate awareness and frequency of use of mouthguards in children and adolescents who engage in high-risk sports in various federated sports clubs in different provinces of Catalonia (Spain).

MATERIALS

A total of 207 athletes aged between 6 and 18 years who belonged to one of the various official sports clubs across Catalonia (Spain) took part in the study. The participants completed a survey that included 13 anonymous questions to assess their awareness and use of a mouthguard while engaging in high-risk sports, the person who recommended its use, and among other variables, the dental history of sports-related injuries. Statistical analysis was performed using the chi-square test; Fisher's exact test and analysis of variance (ANOVA) were used to determine the relationships among the variables. A p-value of 0.05 and a 95% reliability were considered statistically significant.

CONCLUSION

Use of a mouthguard as a preventive measure in sport was very low. One of the main reasons for this was the large amount of disinformation about this type of protection. It would be beneficial to enforce mandatory use of mouthguards in all high-risk sports.

Fetal heart rate monitoring during fetoscopic repair of open spinal neural tube defects: a single-centre observational cohort study

BACKGROUND

During fetal surgery, the haemodynamic stability of the fetus depends on the haemodynamic stability of the mother. The primary objective of this study was to assess changes in fetal heart rate (FHR) throughout the different stages of surgery. The secondary objective was to assess potential changes in maternal physiological parameters and their association with FHR.

METHODS

This was a single-center observational cohort study conducted between 2015 and 2019 in 26 women undergoing intra-uterine fetoscopic repair of open spina bifida. The primary outcome was FHR. Maternal physiologic parameters were measured at the beginning, during and after surgery. The linear mixed-effects model fitted by maximum likelihood was used to assess changes in each variable at specific times throughout the surgery, and the repeated measures correlation coefficient was used to study the association between FHR and maternal physiological parameters.

RESULTS

One (3.8%) case of fetal bradycardia (FHR <110 beats per minute) required the administration of intramuscular atropine. No other significant FHR changes were observed during surgery. Maternal oesophageal temperature (P <0.001), lactate levels (P=0.002), and mean arterial pressure (P=0.016) changed significantly during surgery, although none of these changes was clinically relevant. The FHR showed a significant association with maternal carbon dioxide tension (r=0.285, 95% CI 0.001 to 0.526) and maternal heart rate (r=0.302, 95% CI 0.025 to 0.535).

CONCLUSION

The FHR remained stable during intra-uterine fetoscopic repair of open spina bifida. Maternal carbon dioxide tension and heart rate may have a mild influence on FHR.

Alternative Splicing Generates a MONOPTEROS Isoform Required for Ovule Development

The plant hormone auxin is a fundamental regulator of organ patterning and development that regulates gene expression via the canonical AUXIN RESPONSE FACTOR (ARF) and AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) combinatorial system. ARF and Aux/IAA factors interact, but at high auxin concentrations, the Aux/IAA transcriptional repressor is degraded, allowing ARF-containing complexes to activate gene expression. ARF5/MONOPTEROS (MP) is an important integrator of auxin signaling in Arabidopsis development and activates gene transcription in cells with elevated auxin levels. Here, we show that in ovules, MP is expressed in cells with low levels of auxin and can activate the expression of direct target genes. We identified and characterized a splice variant of MP that encodes a biologically functional isoform that lacks the Aux/IAA interaction domain. This MP11ir isoform was able to complement inflorescence, floral, and ovule developmental defects in mp mutants, suggesting that it was fully functional. Our findings describe a novel scenario in which ARF post-transcriptional regulation controls the formation of an isoform that can function as a transcriptional activator in regions of subthreshold auxin concentration.

The Importance of Cytokinins during Reproductive Development in Arabidopsis and Beyond

Fertilization and seed formation are fundamental events in the life cycle of flowering plants. The seed is a functional unit whose main purpose is to propagate the plant. The first step in seed development is the formation of male and female gametophytes and subsequent steps culminate in successful fertilization. The detailed study of this process is highly relevant because it directly impacts human needs, such as protecting biodiversity and ensuring sustainable agriculture to feed the increasing world population. Cytokinins comprise a class of phytohormones that play many important roles during plant growth and development and in recent years, the role of this class of phytohormones during reproduction has become clear. Here, we review the role of cytokinins during ovule, pollen and seed formation at the genetic and molecular levels. The expansion of knowledge concerning the molecular mechanisms that control plant reproduction is extremely important to optimise seed production.

Practical recommendations in the obstetrical patient with a COVID-19 infection

La infección por COVID-19 afecta también a las pacientes obstétricas. La atención obstétrica habitual ha continuado a pesar de la pandemia. Existen series de casos de pacientes obstétricas. Parece que las técnicas neuroaxiales son seguras y es importante asegurarse que los bloqueos funcionen correctamente antes de una cesárea. Es por esto que se recomienda que los bloqueos sean realizados por anestesiólogos expertos. La protección y seguridad de los profesionales es un punto fundamental y, en caso de anestesia general, también se recomienda acudir al anestesiólogo más experto. Las pacientes gravemente enfermas deben reconocerse rápida y precozmente, para poder suministrarles el tratamiento adecuado lo antes posible. La susceptibilidad a las trombosis hace que la anticoagulación profiláctica sea prioritaria.

Effectiveness of steroids versus placebo in preventing upper airway obstruction after extubation in critically ill children: rationale and design of a multicentric, double-blind, randomized study

Background

Post-extubation upper airway obstruction (UAO) is a frequent complication causing stridor and respiratory distress, which occasionally require reintubation, thereby increasing morbidity and mortality rates. Contradictory results have been obtained in studies assessing the effectiveness of steroids in preventing post-extubation UAO, and the available evidence is limited. We designed a multicentric randomized, placebo-controlled study to explore the effectiveness of dexamethasone in preventing post-extubation UAO in children.

Methods

A multicentric, prospective, double-blind, randomized, placebo-controlled, phase IV clinical trial has been designed. The sample will include pediatric patients who are between 1 month and 16 years of age and who have been intubated for more than 48 h. Patients who have airway disorders or who have received steroids within the previous seven days will be excluded. Patients will be randomly assigned to receive either placebo or a therapy with dexamethasone 0.25 mg/kg every 6 h to be started 6 to 12 h prior to extubation (to a total of four doses). Randomization will be performed at a 1:1 ratio. Follow-up of patients will be carried out for 48 h after extubation. The main objective of this study is to access the reduction in the incidence of moderate to severe UAO symptoms following extubation. Secondary objectives include assessing the decrease in the incidence of reintubation, evaluating the use of additional therapies for UAO, and monitoring potential side effects of dexamethasone.

Discussion

The results of this study will contribute to the existing evidence on prophylaxis for post-extubation airway obstruction.

Trial registration

EudraCT identifier: 2009–016596-30. Registered on May 11, 2010.

Genetic insights into the modification of the pre-fertilization mechanisms during plant domestication

Plant domestication is the process of adapting plants to human use by selecting specific traits. The selection process often involves the modification of some components of the plant reproductive mechanisms. Allelic variants of genes associated with flowering time, vernalization, and the circadian clock are responsible for the adaptation of crops, such as rice, maize, barley, wheat, and tomato, to non-native latitudes. Modifications in the plant architecture and branching have been selected for higher yields and easier harvests. These phenotypes are often produced by alterations in the regulation of the transition of shoot apical meristems to inflorescences, and then to floral meristems. Floral homeotic mutants are responsible for popular double-flower phenotypes in Japanese cherries, roses, camellias, and lilies. The rise of peloric flowers in ornamentals such as snapdragon and florists' gloxinia is associated with non-functional alleles that control the relative expansion of lateral and ventral petals. Mechanisms to force outcrossing such as self-incompatibility have been removed in some tree crops cultivars such as almonds and peaches. In this review, we revisit some of these important concepts from the plant domestication perspective, focusing on four topics related to the pre-fertilization mechanisms: flowering time, inflorescence architecture, flower development, and pre-fertilization self-incompatibility mechanisms.

CUP-SHAPED COTYLEDON1 (CUC1) and CUC2 regulate cytokinin homeostasis to determine ovule number in Arabidopsis

Seeds derive from ovules upon fertilization and therefore the total number of ovules determines the final seed yield, a fundamental trait in crop plants. Among the factors that co-ordinate the process of ovule formation, the transcription factors CUP-SHAPED COTYLEDON 1 (CUC1) and CUC2 and the hormone cytokinin (CK) have a particularly prominent role. Indeed, the absence of both CUC1 and CUC2 causes a severe reduction in ovule number, a phenotype that can be rescued by CK treatment. In this study, we combined CK quantification with an integrative genome-wide target identification approach to select Arabidopsis genes regulated by CUCs that are also involved in CK metabolism. We focused our attention on the functional characterization of UDP-GLUCOSYL TRANSFERASE 85A3 (UGT85A3) and UGT73C1, which are up-regulated in the absence of CUC1 and CUC2 and encode enzymes able to catalyse CK inactivation by O-glucosylation. Our results demonstrate a role for these UGTs as a link between CUCs and CK homeostasis, and highlight the importance of CUCs and CKs in the determination of seed yield.

Fetoscopic two-layer closure of open neural tube defects

OBJECTIVE

Fetoscopy for closure of open neural tube defects (NTD) remains controversial, as the use of patches or single-layer closure is not considered to meet the standards of good neurosurgical reconstruction. In this study, we describe a fetoscopic two-layer (myofascial and skin) closure technique for the treatment of NTD in five patients and report the preliminary anatomical outcome at birth.

METHODS

From February to September 2017, five pregnant women with a fetus with a NTD, including three cases of myelomeningocele and two cases of myelocele, were operated on using a fetoscopic two-layer closure technique. In this technique, with the uterus exteriorized and using three 10-Fr ports, the placode is dissected from the surrounding tissue and detethered, removing the cystic tissue. The skin is undermined by blunt dissection and the defect is sutured to the midline in two layers (myofascial and skin) using a running 4/0 resorbable barbed suture.

RESULTS

Median gestational age at the procedure was 24 + 3 (range, 23 + 5 to 27 + 3) weeks. Surgery was successful in all cases, without any intraoperative complications. Median time in surgery was 180 (range, 140-180) min and median time for fetoscopy was 105 (range, 65-120) min. In terms of obstetric complications, three cases of premature rupture of membranes and one case of chorioamnionitis were recorded. Median gestational age at delivery was 34 + 1 (range, 25 + 4 to 37 + 2) weeks and two patients delivered vaginally. The closed defect was watertight with good quality tissue in all cases.

CONCLUSION

Fetoscopic two-layer closure of NTD may improve the quality of the tissue covering the defect, diminishing the need for postnatal surgical revision, and preserving the well-documented beneficial effects of prenatal closure on the neural tissue and hindbrain herniation. However, this technique may not be appropriate for those cases with wide diastasis of the myofascial layer or with a low quantity of available tissue. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.

SUMOylation Inhibition Mediated by Disruption of SUMO E1-E2 Interactions Confers Plant Susceptibility to Necrotrophic Fungal Pathogens

Protein modification by SUMO modulates essential biological processes in eukaryotes. SUMOylation is facilitated by sequential action of the E1-activating, E2-conjugating, and E3-ligase enzymes. In plants, SUMO regulates plant development and stress responses, which are key determinants in agricultural productivity. To generate additional tools for advancing our knowledge about the SUMO biology, we have developed a strategy for inhibiting in vivo SUMO conjugation based on disruption of SUMO E1-E2 interactions through expression of E1 SAE2^UFDCt domain. Targeted mutagenesis and phylogenetic analyses revealed that this inhibition involves a short motif in SAE2^UFDCt highly divergent across kingdoms. Transgenic plants expressing the SAE2^UFDCt domain displayed dose-dependent inhibition of SUMO conjugation, and have revealed the existence of a post-transcriptional mechanism that regulates SUMO E2 conjugating enzyme levels. Interestingly, these transgenic plants displayed increased susceptibility to necrotrophic fungal infections by Botrytis cinerea and Plectosphaerella cucumerina. Early after fungal inoculation, host SUMO conjugation was post-transcriptionally downregulated, suggesting that targeting SUMOylation machinery could constitute a novel mechanism for fungal pathogenicity. These findings support the role of SUMOylation as a mechanism involved in plant protection from environmental stresses. In addition, the strategy for inhibiting SUMO conjugation in vivo described in this study might be applicable in important crop plants and other non-plant organisms regardless of their genetic complexity.

Transcriptomic Signature of the SHATTERPROOF2 Expression Domain Reveals the Meristematic Nature of Arabidopsis Gynoecial Medial Domain

Plant meristems, like animal stem cell niches, maintain a pool of multipotent, undifferentiated cells that divide and differentiate to give rise to organs. In Arabidopsis (Arabidopsis thaliana), the carpel margin meristem is a vital meristematic structure that generates ovules from the medial domain of the gynoecium, the female floral reproductive structure. The molecular mechanisms that specify this meristematic region and regulate its organogenic potential are poorly understood. Here, we present a novel approach to analyze the transcriptional signature of the medial domain of the Arabidopsis gynoecium, highlighting the developmental stages that immediately proceed ovule initiation, the earliest stages of seed development. Using a floral synchronization system and a SHATTERPROOF2 (SHP2) domain-specific reporter, paired with FACS and RNA sequencing, we assayed the transcriptome of the gynoecial medial domain with temporal and spatial precision. This analysis reveals a set of genes that are differentially expressed within the SHP2 expression domain, including genes that have been shown previously to function during the development of medial domain-derived structures, including the ovules, thus validating our approach. Global analyses of the transcriptomic data set indicate a similarity of the pSHP2-expressing cell population to previously characterized meristematic domains, further supporting the meristematic nature of this gynoecial tissue. Our method identifies additional genes including novel isoforms, cis-natural antisense transcripts, and a previously unrecognized member of the REPRODUCTIVE MERISTEM family of transcriptional regulators that are potential novel regulators of medial domain development. This data set provides genome-wide transcriptional insight into the development of the carpel margin meristem in Arabidopsis.

Cytokinin response factors integrate auxin and cytokinin pathways for female reproductive organ development

The developmental program of the pistil is under the control of both auxin and cytokinin, which crosstalk converges on the regulation of the auxin carrier PIN-FORMED 1 (PIN1). Here we show that in the triple transcription factor mutant cytokinin response factor 2 (crf2) crf3 crf6 both pistil length and ovule number were reduced. PIN1 expression was also lower in the triple mutant and the phenotypes couldn't be rescued by exogenous cytokinin application. pin1 complementation studies using genomic PIN1 constructs showed that the pistil phenotypes were only rescued when the PCRE1 domain, to which CRFs bind, was present. Without this domain, pin mutants resemble the crf2 crf3 crf6 triple mutant, indicating the pivotal role of CRFs in the auxin-cytokinin crosstalk.

Live and let die: a REM complex promotes fertilization through synergid cell death in Arabidopsis

Fertilization in flowering plants requires a complex series of coordinated events involving interaction between the male and female gametophyte. We report here molecular data on one of the key events underpinning this process – the death of the receptive synergid cell and the coincident bursting of the pollen tube inside the ovule to release the sperms.

We show that two REM transcription factors, VALKYRIE (VAL) and VERDANDI (VDD), both targets of the ovule identity MADS-box complex SEEDSTICK-SEPALLATA3, interact to control the death of the receptive synergid cell. In vdd_1/+ mutants and VAL_RNAi lines we find that GAMETOPHYTIC FACTOR 2 (GFA2), required for synergid degeneration, is down regulated, while FERONIA (FER) and MYB98 expression, necessary for pollen tube attraction and perception remain unaffected. We also demonstrate that the vdd_1/+ phenotype can be rescued by expressing VDD or GFA2 in the synergid cells. Taken together, our findings reveal that the death of the receptive synergid cell is essential for the maintenance of the following generations, and that a complex formed of VDD and VAL regulate this event.

Diversification of SUMO-activating enzyme in Arabidopsis: implications in SUMO conjugation

Sumoylation is an essential posttranslational modification that participates in many biological processes including stress responses. However, little is known about the mechanisms that control Small Ubiquitin-like MOdifier (SUMO) conjugation in vivo. We have evaluated the regulatory role of the heterodimeric E1 activating enzyme, which catalyzes the first step in SUMO conjugation. We have established that the E1 large SAE2 and small SAE1 subunits are encoded by one and three genes, respectively, in the Arabidopsis genome. The three paralogs genes SAE1a, SAE1b1, and SAE1b2 are the result of two independent duplication events. Since SAE1b1 and SAE1b2 correspond to two identical copies, only two E1 small subunit isoforms are present in vivo: SAE1a and SAE1b. The E1 heterodimer nuclear localization is modulated by the C-terminal tail of the SAE2 subunit. In vitro, SUMO conjugation rate is dependent on the SAE1 isoform contained in the E1 holoenzyme and our results suggest that downstream steps to SUMO-E1 thioester bond formation are affected. In vivo, SAE1a isoform deletion in T-DNA insertion mutant plants conferred sumoylation defects upon abiotic stress, consistent with a sumoylation defective phenotype. Our results support previous data pointing to a regulatory role of the E1 activating enzyme during SUMO conjugation and provide a novel mechanism to control sumoylation in vivo by diversification of the E1 small subunit.

[Anesthesia for cesarean section in a patient with recessive dystrophic epidermolysis bullosa]

Recessive dystrophic epidermolysis bullosa is inherited as a rare autosomal disorder which causes blisters to form in the skin. We describe the treatment of a 39-year-old parturient with this condition. She was scheduled for elective cesarean section at 37 weeks' gestation. The patient had widespread skin lesions, had lost fingers, and had esophageal stenosis. The cesarean was performed under spinal anesthesia without complications. Recessive dystrophic epidermolysis bullosa requires adaptation of anesthetic technique that includes control over posture and careful handling of the skin. Material for attaching monitoring devices and inserting venous lines must be adapted to the particular deformities and skin lesions present.

[Fetoscopic tracheal occlusion for the treatment of severe congenital diaphragmatic hernia: preliminary results]

OBJECTIVES

To evaluate survival and lung growth in fetuses with severe congenital diaphragmatic hernia (CDH) treated with fetoscopic tracheal occlusion (FETO) compared with control fetuses and to analyze possible complications of the anesthetic techniques used.

PATIENTS AND METHODS

This prospective study was performed on fetuses with CDH. FETO was undertaken before the 29th week of gestation on fetuses with a lung-to-head ratio (LHR) less than 1. FETO was not performed on fetuses with an LHR between 1.0 and 1.5 or those with an LHR less than 1 where consent was not given. Lung growth was monitored by means of LHR. FETO was performed under fetal intramuscular anesthesia and maternal epidural anesthesia and sedation with remifentanil.

RESULTS

Seventeen fetuses were included in the study. FETO was performed on 11 fetuses and was effective in 9. The median percentage difference between LHR at diagnosis and prior to FETO was 1.15% (P=.183); between diagnosis and before removing the balloon, the difference was 130.5% (P=.003); and between diagnosis and before delivery, 90.18% (P=.003). In the control group (n=6), the median percentage difference between LHR at diagnosis and before delivery was 49.25% (P=.028). No significant hemodynamic or respiratory changes occurred in either mother or fetus during fetoscopy. All the fetuses in the control group died; 45.5% of those in the FETO group survived.

CONCLUSIONS

The use of FETO in cases of CDH appears to increase survival and lung growth. Fetal anesthesia in association with maternal epidural anesthesia and sedation makes it possible to place and remove the endotracheal balloon via fetoscopy with acceptable maternal comfort and without notable complications.

Production of cecropin A in transgenic rice plants has an impact on host gene expression

Expression of the cecropin A gene in rice confers resistance to the rice blast fungus Magnaporthe oryzae. In this study, a polymerase chain reaction-based suppression subtractive hybridization approach was used to generate a cDNA macroarray from the elite japonica rice (Oryza sativa L.) cultivar 'Senia'. Gene expression studies revealed that the expression of components of the protein secretory and vesicular transport machinery is co-ordinately activated at the pre-invasive stage of infection of rice by the blast fungus. Comparisons of gene expression between wild-type and cecropin A plants revealed the over-expression of genes involved in protection against oxidative stress in transgenic plants in the absence of the pathogen, which correlated well with the tolerance of these plants to oxidative stress. A subcellular fractionation analysis suggested that cecropin A accumulates in the endoplasmic reticulum in cecropin A rice. Moreover, a large number of genes related to the processes of synthesis, folding and stabilization of proteins that enter into the secretory pathway are over-expressed in cecropin A rice, confirming that these plants constitutively express the unfolded protein response. Transgenic expression of cecropin A in rice has an effect on the transcriptional reprogramming that accompanies plant adaptation to fungal infection. Overall, this study provides evidence for transgene-induced changes in gene expression in cecropin A rice under both optimal growth conditions and stress conditions imposed by fungal infection. The data also indicate that resistance to blast in cecropin A rice may be the consequence of a combination of the antifungal activity of cecropin A and cecropin A-mediated over-expression of rice genes.

[Two cases of congenital airway obstruction managed with ex utero intrapartum treatment procedures: anesthetic implications]

An ex utero intrapartum treatment (EXIT) procedure provides sufficient time to gain control of the potentially obstructed fetal upper airway while uterine placental circulation is maintained during cesarean section. We report 2 cases in which fetal congenital upper airway obstruction was managed without complications during EXIT procedures. We also discuss general considerations concerning the obstetric patient and the performance of intramuscular fetal anesthesia. Before the hysterotomy, sevoflurane at 1.5 minimum alveolar concentration was administered to assure sufficient uterine relaxation during EXIT. The 2 parturients remained hemodynamically stable during the procedure and uterine and placental perfusion was adequate. Nasotracheal intubation was possible in 1 fetus after a cervical mass was dissected. In the other, a tracheostomy was created. After the umbilical cord was clamped, the concentration of sevoflurane anesthetic gas was reduced and oxytocin and methylergometrine were administered to induce adequate uterine contractions within a few minutes. Both neonates survived the EXIT procedure with no complications.

Cerebral hemodynamic changes during sustained hypocapnia in severe head injury: can hyperventilation cause cerebral ischemia?

Hyperventilation (HV) is routinely used in the management of increased intracranial pressure (ICP) in severe head injury. However, this treatment continues to be controversial because it has been reported that long-lasting reduced cerebral blood flow (CBF) due to profound sustained hypocapnia may contribute to the development or deterioration of ischemic lesions. Our goal in this study was to analyze the effects of sustained hyperventilation on cerebral hemodynamics (CBF, ICP) and metabolism (arterio jugular differences of lactates = AVDL). CO2-reactivity and CBF was estimated using AVDO2 (arteriojugular differences of oxygen content). Global cerebral ischemia and increased anaerobic metabolism were considered according to AVDO2 and AVDL respectively. Thirty-three patients with severe and moderate head injury and increased ICP were included. Within 72 hours after accident, patients were hyperventilated for a period of 4 hours. During this time jugular oxygen saturation (SjO2), arterial oxygen saturation (SaO2), ICP, mean arterial blood pressure (MABP), AVDO2 and AVDL were recorded. In our study, most patients preserved CO2-reactivity (88.2%). In these cases HV was very effective in lowering ICP. Our findings showed that this reduction was due to a CBF decrease. According to basal AVDO2 twenty-five patients (75.7%) were considered as hyperemic and eight (24.2%) as not hyperemic. Global ischemia and increased anaerobic metabolism were detected in one case in the non-hyperemic group. According to AVDO2 and AVDL, no adverse effects were found during four hours of HV in hyperemic patients. Nevertheless, AVDO2 and AVDL are global measurements and might not detect regional ischemia surrounding focal lesions such as contusions and haematomas. We suggest that monitoring of AVDO2 or other haemometabolic variables should be mandatory when sustained HV is used in the management of head injury patients.