Effect of a temporary lying position on cerebral hemodynamic and cerebral oxygenation parameters in patients with severe brain trauma.

BACKGROUND: Temporary transition from the half-seated position (HSP) to the lying position (LyP) is often associated with an increase in intracranial pressure (ICP) during management of patients with severe traumatic brain injury (TBI). This study was designed to assess the impact of the temporary LyP on cerebral perfusion and oxygenation in cases of severe TBI. METHOD: Patients with a severe blunt TBI with indication of ICP monitoring were prospectively included. Patients underwent standardized management according to the international guidelines to minimize secondary insults. For each patient, a maneuver to a LyP for 30 min was performed daily during the first 7 days of hospitalization. ICP, cerebral perfusion pressure (CPP), mean velocity (Vm), pulsatility index (PI), regional cerebral oxygen saturation (rScO2), jugular venous oxygen saturation (SvjO2)) were compared in the HSP and the LyP. RESULTS: Twenty-four 24 patients were included. The median Glasgow coma scale score was 6 (interquartile range (IQR), 3-8), the median injury severity score was 32 (IQR, 25-48), and the mean age was 39 ± 16 years. On day 1, ICP (+ 6 mmHg (IQR, 4-7 mmHg)) and CPP (+ 10 mmHg (IQR, 5-14 mmHg) were significantly increased in the LyP compared with the HSP. Vm increased significantly in the LyP on the mainly injured side (+ 6 cm/s (IQR, + 0-11 cm/s); P = 0.01) and on the less injured side (+ 4 cm/s (IQR, + 1-8 cm/s); P < 0.01). rScO2 behaved similarly (+ 2 points (IQR, + 2-4 points) and + 3 points (IQR, + 2-5 points), respectively; P < 0.001). Mixed models highlighted the significant association between the position and CPP, Vm, rScO2, with more favorable conditions in the lying position. CONCLUSIONS: Within the first week of management, the temporary LyP in cases of severe TBI was associated with a moderate increase in CPP, Vm, and rScO2despite a moderate increase in ICP.

Identification and functional characterization of two HOOKLESS genes in Tomato (Solanum lycopersicum).

The apical hook of dark-grown dicotyledonous plants results from asymmetric growth of the inner and outer sides of the upper part of the hypocotyl. This protective structure prevents damage of the shoot apical meristem and the young leaves as the seedling pushes through the soil. HOOKLESS (HLS1) of Arabidopsis was recognised as an ethylene response gene whose product is required for hook formation. We cloned two cDNAs from tomato, Sl-HLS1 and Sl-HLS2, and showed through the complementation of the Arabidopsis hls1 mutant that the encoded proteins are functional orthologs of At-HLS1. The genomic clones of Sl-HLS1 and Sl-HLS2 showed similar structure with two introns and three exons. While the data indicate complete functional redundancy between the two tomato HLS genes, only the expression of Sl-HLS2 is regulated by ethylene and auxin and the ethylene-induced expression of Sl-HLS2 is localised in the outer side of the hook while the auxin-responsive expression is not restricted to a specific side of the hook. 1-MCP, an inhibitor of ethylene signalling, inhibited auxin-enhanced accumulation of Sl-HLS2 mRNA in the apical hook suggesting that regulation of Sl-HLS2 by auxin is ethylene-dependent. The overexpression of tomato Sl-HLS1 and Sl-HLS2 in Arabidopsis confers hypersensitivity to ethylene. The data presented bring further insight into the complex ethylene-auxin interplay in hook formation.

Comprehensive Profiling of Ethylene Response Factor Expression Identifies Ripening-Associated ERF Genes and Their Link to Key Regulators of Fruit Ripening in Tomato.

Our knowledge of the factors mediating ethylene-dependent ripening of climacteric fruit remains limited. The transcription of ethylene-regulated genes is mediated by ethylene response factors (ERFs), but mutants providing information on the specific role of the ERFs in fruit ripening are still lacking, likely due to functional redundancy among this large multigene family of transcription factors. We present here a comprehensive expression profiling of tomato (Solanum lycopersicum) ERFs in wild-type and tomato ripening-impaired tomato mutants (Never-ripe [Nr], ripening-inhibitor [rin], and non-ripening [nor]), indicating that out of the 77 ERFs present in the tomato genome, 27 show enhanced expression at the onset of ripening while 28 display a ripening-associated decrease in expression, suggesting that different ERFs may have contrasting roles in fruit ripening. Among the 19 ERFs exhibiting the most consistent up-regulation during ripening, the expression of 11 ERFs is strongly down-regulated in rin, nor, and Nr tomato ripening mutants, while only three are consistently up-regulated. Members of subclass E, SlERF.E1, SlERF.E2, and SlERF.E4, show dramatic down-regulation in the ripening mutants, suggesting that their expression might be instrumental in fruit ripening. This study illustrates the high complexity of the regulatory network connecting RIN and ERFs and identifies subclass E members as the most active ERFs in ethylene- and RIN/NOR-dependent ripening.

Thoracic Trauma Severity score on admission allows to determine the risk of delayed ARDS in trauma patients with pulmonary contusion.

BACKGROUND: Pulmonary contusion is a major risk factor of acute respiratory distress syndrome (ARDS) in trauma patients. As this complication may appear after a free interval of 24-48 h, detection of patients at risk is essential. The main objective of this study was to assess the performance of the Thoracic Trauma Severity (TTS) score upon admission in predicting delayed ARDS in blunt trauma patients with pulmonary contusion. METHODS: All blunt thoracic trauma patients admitted consecutively to our trauma centre between January 2005 and December 2009 were retrospectively included if they presented a pulmonary contusion on the admission chest computed tomography scan. Main outcome measure was the presence of moderate or severe ARDS (PaO2/FiO2 ratio≤200) for 48 h or more. The global ability of the TTS score to predict ARDS was studied by ROC curves with a threshold analysis using a grey zone approach. RESULTS: Of 329 patients studied (75% men, mean age 36.9 years [SD 17.8 years], mean Injury Severity Score 21.7 [SD 16.0]), 82 (25%) presented with ARDS (mean lowest PaO2/FiO2 ratio of 131 [SD 34]). The area under the ROC curves for the TTS score in predicting ARDS was 0.82 (95% CI 0.78-0.86) in the overall population. TTS scores between 8 and 12 belonged to the inconclusive grey zone. A TTS score of 13-25 was found to be independent risk factors of ARDS (OR 25.8 [95% CI 6.7-99.6] P<0.001). CONCLUSIONS: An extreme TTS score on admission accurately predicts the occurrence of delayed ARDS in blunt thoracic trauma patients affected by pulmonary contusion. This simple score could guide early decision making and management for a non-negligible proportion of this specific population.

Ethylene Control of Fruit Ripening: Revisiting the Complex Network of Transcriptional Regulation.

The plant hormone ethylene plays a key role in climacteric fruit ripening. Studies on components of ethylene signaling have revealed a linear transduction pathway leading to the activation of ethylene response factors. However, the means by which ethylene selects the ripening-related genes and interacts with other signaling pathways to regulate the ripening process are still to be elucidated. Using tomato (Solanum lycopersicum) as a reference species, the present review aims to revisit the mechanisms by which ethylene regulates fruit ripening by taking advantage of new tools available to perform in silico studies at the genome-wide scale, leading to a global view on the expression pattern of ethylene biosynthesis and response genes throughout ripening. Overall, it provides new insights on the transcriptional network by which this hormone coordinates the ripening process and emphasizes the interplay between ethylene and ripening-associated developmental factors and the link between epigenetic regulation and ethylene during fruit ripening.

Carotenoid accumulation during tomato fruit ripening is modulated by the auxin-ethylene balance.

BACKGROUND: Tomato fruit ripening is controlled by ethylene and is characterized by a shift in color from green to red, a strong accumulation of lycopene, and a decrease in ß-xanthophylls and chlorophylls. The role of other hormones, such as auxin, has been less studied. Auxin is retarding the fruit ripening. In tomato, there is no study of the carotenoid content and related transcript after treatment with auxin. RESULTS: We followed the effects of application of various hormone-like substances to "Mature-Green" fruits. Application of an ethylene precursor (ACC) or of an auxin antagonist (PCIB) to tomato fruits accelerated the color shift, the accumulation of lycopene, α-, ß-, and δ-carotenes and the disappearance of ß-xanthophylls and chlorophyll b. By contrast, application of auxin (IAA) delayed the color shift, the lycopene accumulation and the decrease of chlorophyll a. Combined application of IAA + ACC led to an intermediate phenotype. The levels of transcripts coding for carotenoid biosynthesis enzymes, for the ripening regulator Rin, for chlorophyllase, and the levels of ethylene and abscisic acid (ABA) were monitored in the treated fruits. Correlation network analyses suggest that ABA, may also be a key regulator of several responses to auxin and ethylene treatments. CONCLUSIONS: The results suggest that IAA retards tomato ripening by affecting a set of (i) key regulators, such as Rin, ethylene and ABA, and (ii) key effectors, such as genes for lycopene and ß-xanthophyll biosynthesis and for chlorophyll degradation.

Prevalence of large and occult pneumothoraces in patients with severe blunt trauma upon hospital admission: experience of 526 cases in a French level 1 trauma center.

BACKGROUND: Occult pneumothoraces (PTXs), which are not visible on chest x-ray, may progress to tension PTX. The aim of study was to establish the prevalence of large occult PTXs upon admission of patients with severe blunt trauma, according to prehospital mechanical ventilation. METHODS: Patients with severe trauma consecutively admitted to our institution for 5 years were retrospectively analyzed. All patients with blunt thoracic trauma who had undergone computed tomographic (CT) within the first hour of hospitalization were included. Mechanical ventilation was considered as early if it was introduced in the prehospital period or on arrival at the hospital. Occult PTXs were defined as PTXs not visible on chest x-ray. All PTXs were measured on CT scan (largest thickness and vertical dimension). Large occult PTXs were defined by a largest thickness of 30 mm or more. RESULTS: Of the 526 patients studied, 395 (75%) were male, mean age was 37.9 years, mean Injury Severity Score was 22.2, and 247 (47%) received early mechanical ventilation. Of 429 diagnosed PTXs, 296 (69%) were occult. The proportion of occult PTXs classified as large was 11% (95% confidence interval, 8%-15%). The overall prevalence of large occult PTXs was 6% (95% confidence interval, 4%-8%). Both CT measurements and proportion of large occult PTXs were found statistically comparable in patients with or without mechanical ventilation. CONCLUSIONS: Six percent of studied patients with severe trauma had a large and occult PTX as soon as admission despite a normal chest x-ray result. The observed sizes and rates of occult PTX were comparable regardless of the initiation of early mechanical ventilation.

The auxin Sl-IAA17 transcriptional repressor controls fruit size via the regulation of endoreduplication-related cell expansion.

Auxin is known to regulate cell division and cell elongation, thus controlling plant growth and development. Part of the auxin signaling pathway depends on the fine-tuned degradation of the auxin/indole acetic acid (Aux/IAA) transcriptional repressors. Recent evidence indicates that Aux/IAA proteins play a role in fruit development in tomato (Solanum lycopersicum Mill.), a model species for fleshy fruit development. We report here on the functional characterization of Sl-IAA17 during tomato fruit development. Silencing of Sl-IAA17 by an RNA interference (RNAi) strategy resulted in the production of larger fruit than the wild type. Histological analyses of the fruit organ and tissues demonstrated that this phenotype was associated with a thicker pericarp, rather than larger locules and/or a larger number of seeds. Microscopic analysis demonstrated that the higher pericarp thickness in Sl-IAA17 RNAi fruits was not due to a larger number of cells, but to the increase in cell size. Finally, we observed that the cell expansion in the transgenic fruits is tightly coupled with higher ploidy levels than in the wild type, suggesting a stimulation of the endoreduplication process. In conclusion, this work provides new insights into the function of the Aux/IAA pathway in fleshy fruit development, especially fruit size and cell size determination in tomato.

The chimeric repressor version of an Ethylene Response Factor (ERF) family member, Sl-ERF.B3, shows contrasting effects on tomato fruit ripening.

Fruit ripening involves a complex interplay between ethylene and ripening-associated transcriptional regulators. Ethylene Response Factors (ERFs) are downstream components of ethylene signaling, known to regulate the expression of ethylene-responsive genes. Although fruit ripening is an ethylene-regulated process, the role of ERFs remains poorly understood. The role of Sl-ERF.B3 in tomato (Solanum lycopersicum) fruit maturation and ripening is addressed here using a chimeric dominant repressor version (ERF.B3-SRDX). Over-expression of ERF.B3-SRDX results in a dramatic delay of the onset of ripening, enhanced climacteric ethylene production and fruit softening, and reduced pigment accumulation. Consistently, genes involved in ethylene biosynthesis and in softening are up-regulated and those of carotenoid biosynthesis are down-regulated. Moreover, the expression of ripening regulators, such as RIN, NOR, CNR and HB-1, is stimulated in ERF.B3-SRDX dominant repressor fruits and the expression pattern of a number of ERFs is severely altered. The data suggest the existence of a complex network enabling interconnection between ERF genes which may account for the pleiotropic alterations in fruit maturation and ripening. Overall, the study sheds new light on the role of Sl-ERF.B3 in the transcriptional network controlling the ripening process and uncovers a means towards uncoupling some of the main ripening-associated processes.

Characterization of the tomato ARF gene family uncovers a multi-levels post-transcriptional regulation including alternative splicing.

BACKGROUND: The phytohormone auxin is involved in a wide range of developmental processes and auxin signaling is known to modulate the expression of target genes via two types of transcriptional regulators, namely, Aux/IAA and Auxin Response Factors (ARF). ARFs play a major role in transcriptional activation or repression through direct binding to the promoter of auxin-responsive genes. The present study aims at gaining better insight on distinctive structural and functional features among ARF proteins. RESULTS: Building on the most updated tomato (Solanum lycopersicon) reference genome sequence, a comprehensive set of ARF genes was identified, extending the total number of family members to 22. Upon correction of structural annotation inconsistencies, renaming the tomato ARF family members provided a consensus nomenclature for all ARF genes across plant species. In silico search predicted the presence of putative target site for small interfering RNAs within twelve Sl-ARFs while sequence analysis of the 5'-leader sequences revealed the presence of potential small uORF regulatory elements. Functional characterization carried out by transactivation assay partitioned tomato ARFs into repressors and activators of auxin-dependent gene transcription. Expression studies identified tomato ARFs potentially involved in the fruit set process. Genome-wide expression profiling using RNA-seq revealed that at least one third of the gene family members display alternative splicing mode of regulation during the flower to fruit transition. Moreover, the regulation of several tomato ARF genes by both ethylene and auxin, suggests their potential contribution to the convergence mechanism between the signaling pathways of these two hormones. CONCLUSION: All together, the data bring new insight on the complexity of the expression control of Sl-ARF genes at the transcriptional and post-transcriptional levels supporting the hypothesis that these transcriptional mediators might represent one of the main components that enable auxin to regulate a wide range of physiological processes in a highly specific and coordinated manner.

A dominant repressor version of the tomato Sl-ERF.B3 gene confers ethylene hypersensitivity via feedback regulation of ethylene signaling and response components.

Ethylene Response Factors (ERFs) are downstream components of the ethylene signal transduction pathway, although their role in ethylene-dependent developmental processes remains poorly understood. As the ethylene-inducible tomato Sl-ERF.B3 has been shown previously to display a strong binding affinity to GCC-box-containing promoters, its physiological significance was addressed here by a reverse genetics approach. However, classical up- and down-regulation strategies failed to give clear clues to its roles in planta, probably due to functional redundancy among ERF family members. Expression of a dominant repressor ERF.B3-SRDX version of Sl-ERF.B3 in the tomato resulted in pleiotropic ethylene responses and vegetative and reproductive growth phenotypes. The dominant repressor etiolated seedlings displayed partial constitutive ethylene response in the absence of ethylene and adult plants exhibited typical ethylene-related alterations such as leaf epinasty, premature flower senescence and accelerated fruit abscission. The multiple symptoms related to enhanced ethylene sensitivity correlated with the altered expression of ethylene biosynthesis and signaling genes and suggested the involvement of Sl-ERF.B3 in a feedback mechanism that regulates components of ethylene production and response. Moreover, Sl-ERF.B3 was shown to modulate the transcription of a set of ERFs and revealed the existence of a complex network interconnecting different ERF genes. Overall, the study indicated that Sl-ERF.B3 had a critical role in the regulation of multiple genes and identified a number of ERFs among its primary targets, consistent with the pleiotropic phenotypes displayed by the dominant repression lines.

SlARF4, an auxin response factor involved in the control of sugar metabolism during tomato fruit development.

Successful completion of fruit developmental programs depends on the interplay between multiple phytohormones. However, besides ethylene, the impact of other hormones on fruit quality traits remains elusive. A previous study has shown that down-regulation of SlARF4, a member of the tomato (Solanum lycopersicum) auxin response factor (ARF) gene family, results in a dark-green fruit phenotype with increased chloroplasts (Jones et al., 2002). This study further examines the role of this auxin transcriptional regulator during tomato fruit development at the level of transcripts, enzyme activities, and metabolites. It is noteworthy that the dark-green phenotype of antisense SlARF4-suppressed lines is restricted to fruit, suggesting that SlARF4 controls chlorophyll accumulation specifically in this organ. The SlARF4 underexpressing lines accumulate more starch at early stages of fruit development and display enhanced chlorophyll content and photochemical efficiency, which is consistent with the idea that fruit photosynthetic activity accounts for the elevated starch levels. SlARF4 expression is high in pericarp tissues of immature fruit and then undergoes a dramatic decline at the onset of ripening concomitant with the increase in sugar content. The higher starch content in developing fruits of SlARF4 down-regulated lines correlates with the up-regulation of genes and enzyme activities involved in starch biosynthesis, suggesting their negative regulation by SlARF4. Altogether, the data uncover the involvement of ARFs in the control of sugar content, an essential feature of fruit quality, and provide insight into the link between auxin signaling, chloroplastic activity, and sugar metabolism in developing fruit.

Hemoperitoneum semiquantitative analysis on admission of blunt trauma patients improves the prediction of massive transfusion.

BACKGROUND: The purpose of this study was to define whether the semiquantitative analysis of hemoperitoneum increases the accuracy of early prediction of massive transfusion (MT). METHODS: A retrospective review of severe trauma patients consecutively admitted to our trauma intensive care unit between January 2005 and December 2009 was conducted. Patients diagnosed with blunt abdominal trauma who had a computed tomography scan on admission were included. The hemoperitoneum size was defined using the Federle score on computed tomography as large, moderate, or minimal/none. The association between MT (≥10 U of packed red blood cells in the first 24 h) and moderate and large sizes of hemoperitoneum was assessed using a multiple logistic model. RESULTS: Of the 381 patients meeting the inclusion criteria, 270 (71%) were male; the mean age was 35.5 ± 18.2 years and mean injury severity score was 23.4 ± 17. Ninety-seven (26%) had large hemoperitoneum, 107 (28%) had moderate hemoperitoneum, and 177 (46%) had minimal/no hemoperitoneum. Eighty-three patients (22%) required MT. The positive predictive value for MT of a large hemoperitoneum was 41%, 23% for a moderate hemoperitoneum, and 10% for minimal/no hemoperitoneum (P < .001). The corresponding values for hypotensive patients were 61%, 32%, and 25%, respectively (P < .001). In the multivariate analysis model, only the large size of hemoperitoneum was significantly associated with MT (OR 6.4, 95% CI 2.9-14, P < .001, r(2) = 0.47). CONCLUSION: The assessment of the size of hemoperitoneum on admission substantially improves the prediction of MT in trauma patients and should be used to trigger and guide initial haemostatic resuscitation.

Does the size of the hemoperitoneum help to discriminate the bleeding source and guide therapeutic decisions in blunt trauma patients with pelvic ring fracture?

BACKGROUND: In blunt trauma patients with a hemoperitoneum and a pelvic injury, multiple sources of active bleeding may exist. The purpose of this study was to determine whether the size of the hemoperitoneum helps to establish the bleeding source and guide therapeutic decisions in patients with pelvic fractures. METHODS: The charts of patients with pelvic fractures admitted to a trauma intensive care unit from January 2005 to December 2009 were reviewed retrospectively. The hemoperitoneum size was defined by semiquantitative analysis (minimal/none, moderate, and large) using the Federle score on computed tomographic scan or during laparotomy. Active peritoneal hemorrhages requiring immediate laparotomy were compared according to hemoperitoneum size. RESULTS: Of 185 patients, hemoperitoneum did not occur in 116 patients, moderate in 43, and large in 26. Among 102 patients (55%) who were hypotensive (systolic blood pressure <90 mm Hg) on admission, 27 needed therapeutic laparotomy and 15 needed pelvic embolization. Laparotomy (39% vs. 2%) and pelvic embolization (22% vs. 4%) were required significantly more often in patients with hemoperitoneum (moderate or large) than those without hemoperitoneum. The positive predictive value for an active peritoneal hemorrhage derived from qualitative analysis of the hemoperitoneum (moderate or large) was 39% (4% in hypotensive patients and 40% in those requiring pelvic embolization). The corresponding values for large hemoperitoneum only (semiquantitative analysis) were 62%, 70%, and 67%, respectively. CONCLUSION: In patients with pelvic fractures, hemoperitoneum does not mean peritoneal injury requiring hemostatic procedure. Semiquantitative analysis of the hemoperitoneum improves predictability of peritoneal hemorrhage than qualitative analysis of hemoperitoneum. However, there remains numerous false-positives even in presence of large hemoperitoneum associated with hypotension.

What are the specific computed tomography scan criteria that can predict or exclude the need for renal angioembolization after high-grade renal trauma in a conservative management strategy?

BACKGROUND: The indications of renal angioembolization for patients with high-grade renal trauma (HGRT) are based on angiographic criteria to reduce the failure rate of conservative management (CM). There is no consensus to predict or exclude an indication of renal angioembolization with a computed tomography (CT) scan. The aim of this study was to evaluate CT-specific criteria to predict or exclude the need for renal embolization. METHODS: All traumatized patients admitted with renal injury were considered between 2005 and 2009. We included all patients who had an HGRT (classified by American Association for the Surgery of Trauma Organ Injury Scale grade≥3) treated by CM. We collected the demographic, CT, angiographic, management, and outcome data for these patients. CT criteria were retrospectively studied to define their predictive values for renal embolization. RESULTS: Among 101 patients with renal injury, 58 were HGRT, and 53 of them were treated by CM. Ten patients (19%) received renal embolization because of an ongoing renal hemorrhage. There was no significant difference for urologic interventions (2 [20%] vs. 7 [16%]), CM failure rate (1 [10%] vs. 2 [5%]), and during hospital stay between these patients and those who did not received embolization. None of the CT criteria had a negative predictive value for renal embolization to 100%, only the absence of intravascular contrast extravasation associated with a perirenal hematoma rim distance<25 mm excludes an indication for embolization. CONCLUSIONS: In patients with HGRT who had bleeding, a strategy of targeted angiography can be realized safely in using specific CT scan criteria that can predict with high accuracy and exclude the need for embolization, without reducing the success rate of CM.

Long-term sedation in intensive care unit: a randomized comparison between inhaled sevoflurane and intravenous propofol or midazolam.

PURPOSE: To evaluate efficacy and adverse events related to inhaled sevoflurane for long-term sedation compared with standard intravenous (i.v.) sedation with propofol or midazolam. METHODS: Randomized controlled trial. Sixty intensive care unit (ICU) patients expected to require more than 24 h sedation were randomly assigned to one of three groups: group S, inhaled sevoflurane; group P, i.v. propofol; group M, i.v. midazolam. All patients also received i.v. remifentanil for goal-directed sedation (Ramsay scale and pain score) until extubation or for a maximum of 96 h. Primary end points were wake-up times and extubation delay from termination of sedative administration. Proportion of time within Ramsay score 3-4, i.v. morphine consumption at 24 h post extubation, hallucination episodes after end of sedation, adverse events, inorganic fluoride plasma levels, and ambient sevoflurane concentrations were recorded. RESULTS: Forty-seven patients were analyzed. Wake-up time and extubation delay were significantly (P<0.01) shorter in group S (18.6 ± 11.8 and 33.6 ± 13.1 min) than in group P (91.3 ± 35.2 and 326.11 ± 360.2 min) or M (260.2 ± 150.2 and 599.6 ± 586.6 min). Proportion of time within desired interval of sedation score was comparable between groups. Morphine consumption during the 24 h following extubation was lower in group S than in groups P and M. Four hallucination episodes were reported in group P, five in group M, and none in group S (P=0.04). No hepatic or renal adverse events were reported. Mean plasma fluoride value was 82 µmol l(-1) (range 12-220 µmol l(-1)), and mean ambient sevoflurane concentration was 0.3 ± 0.1 ppm. CONCLUSIONS: Long-term inhaled sevoflurane sedation seems to be a safe and effective alternative to i.v. propofol or midazolam. It decreases wake-up and extubation times, and post extubation morphine consumption, and increases awakening quality.

A new index derived from the cerebrovascular pressure transmission and correlated with consciousness recovery in severely head-injured intensive care patients.

BACKGROUND: In patients with serious head trauma, a moderate (20-25 mm Hg) mean level of intracranial pressure (ICP) may fail to distinguish patients with a real deteriorated intracranial status from those who are stable or improving. Because of these limitations, we analyzed the ICP curve in search of other relevant information regarding cerebrovascular pressure transmission. We looked for parameters with physiological meaning extracted from spectral analysis of cerebrovascular pressure transmission and correlated with consciousness recovery in patients with severe head injuries. METHODS: A prospective cohort study was conducted in an intensive care unit of the University Hospital, Montpellier, France, from December 2003 to December 2005. Thirty consecutive patients admitted for severe head trauma were subjected to sedatives, mechanical ventilation, and intraparenchymatous recording of ICP and were evaluated with Glasgow Outcome Scale score. Simultaneous 60-s recordings of ICP and arterial blood pressure (BP) signals, beginning as soon as possible after head trauma, were repeated until death or clinical stabilization, every 15 min, with physicians blinded to the patients' data. Spectra of ICP and BP waveforms were computed with Fourier transform. Amplitudes of cardiac and respiratory harmonics were analyzed. Cardiac (or respiratory) gain was defined as the ratio of amplitudes of cardiac (or respiratory) harmonic of ICP to BP signals and referred to as Gc and Gr, respectively. RESULTS: Twenty of the 30 enrolled patients recovered consciousness (Glasgow Outcome Scale score = 3, 4, or 5). Gr/Gc averaged over the whole recording period performed better in discriminating consciousness recovery (area under receiver operating characteristic [ROC] curve: 0.98; 95% confidence interval [CI]: 0.91-1) than ICP (0.76; 95% CI: 0.54-0.97), cerebral perfusion pressure (0.75; 95% CI: 0.53-0.97) and Gc (0.77; 95% CI: 0.57-0.99) (P < 0.001 for each comparison). When considering the recording period 30 h posttrauma (hpt), 162 hpt, a value of Gr/Gc > or =4 was always associated with consciousness recovery, and the relative risk was equal to 9 (95% CI: 1.42-57.12). CONCLUSIONS: Gr/Gc, which characterizes the cerebrovascular transmission, better discriminates bad evolution than high values of ICP or low values of cerebral perfusion pressure in patients with severe head trauma. A reduction in Gr/Gc ratio might be an early alarm signaling worsening intracranial hemodynamic conditions.

Stimulation of the grape berry expansion by ethylene and effects on related gene transcripts, over the ripening phase.

Grape is considered as a non-climacteric fruit, the maturation of which is independent of ethylene. However, previous work had shown that ethylene is capable of affecting the physiological processes during maturation of grape berries. Experiments were designed to screen the gene pool affected by ethylene at the ripening inception in Cabernet Sauvignon berries. The results showed that only 73 of 14 562 genes of microarray slides were significantly modulated by a 24-h ethylene treatment (4 microl l(-1)), performed 8 weeks after flowering. The study then focused on accumulation of several mRNAs affected by ethylene in relation to the berry size. Indeed, we observed that ethylene application at véraison led to a berry diameter increase. This increase is mainly because of sap intake and cell wall modifications, enabling cell elongation. This was related to changes in the expression pattern of many genes, classified in two groups: (1) 'water exchange' genes: various aquaporins (AQUA) and (2) 'cell wall structure' genes: polygalacturonases, xyloglucan endotransglucosylases (XTH), pectin methyl esterases, cellulose synthases and expansins. The expression patterns were followed either along berry development or in three berry tissues (peel, pulp and seeds). Ethylene stimulates the accumulation of most gene transcripts in 1 h, and in several parts of the berry, this stimulation may last for 24 h in some cases. One XTH and one AQUA seem to be good candidates to explain the ethylene-induced berry expansion. This work brings more clues about the ethylene involvement in the development and ripening of grape berries.

Can electroencephalographic analysis be used to determine sedation levels in critically ill patients?

UNLABELLED: Prolonged use of sedative drugs frequently leads to oversedation of intensive care patients. Clinical assessment scales are not reliable in deeply sedated patients. Parameters obtained from spectral and bispectral analysis of electroencephalogram (EEG) records have been combined to create an index (BIS) to monitor anesthesia depth. The role of such parameters in monitoring the depth of the sedation in intensive care unit (ICU) patients has yet to be determined. We designed the present prospective study to redefine and calculate available spectral and bispectral parameters from raw EEG records and estimate their clinical relevance for the diagnosis of under- or oversedation levels in ICU patients. Forty adult patients receiving continuous midazolam and morphine sedation were included. We obtained 167 clinical evaluations of sedation level using Ramsay and COMFORT scales along with an EEG record of 300 s. Six spectral parameters-relative power of 4 frequency bands (beta, alpha, Theta, and delta), 95th percentile of the power spectrum (SEF95), and 50th percentile of the power spectrum (SEF50) and four bispectral parameters, real triple product, bispectrum (Bispectrum), bicoherence, and ratio 10-were calculated. The relevance of each of these parameters and combinations in predicting too light (Ramsay 1 and 2) or deep (Ramsay 5 and 6) sedation levels was assessed. These calculations were performed before and after exclusion of the agitated patients, whose COMFORT 4 score was above 2. The most relevant parameters for predicting levels of deep sedation (Ramsay 5 and 6) were ratio 10 (area under the curve = 0.763; 95% confidence interval, 0.679-0.833) and SEF95 (area under the curve = 0.687; 95% confidence interval, 0.597-0.767). The most relevant parameters for predicting light levels of sedation (Ramsay 1 and 2) were also ratio 10 (area under the curve = 0.829; 95% confidence interval, 0.695-0.917) and SEF95 (area under the curve = 0.798; 95% confidence interval, 0.650-0.898). There is a modest improvement in relevance of their linear combination in predicting sedation level. Results were similar after exclusion of agitated patients. We conclude that various calculated EEG descriptive parameters exhibited large interindividual variability. There was a strong correlation between EEG spectral and bispectral parameters. Bispectral analysis slightly improves the predictive power of simple spectral analysis in distinguishing too light or deep sedation levels in ICU patients. IMPLICATIONS: Spectral edge frequency 95 and Ratio 10 are the most relevant electroencephalogram (EEG) indexes for monitoring the level of sedation in intensive care unit patients but calculated EEG values exhibited large interindividual variability. Bispectral analysis of EEG provides a slight improvement over simple spectral analysis.