The Aux/IAA, Sl-IAA17 regulates quality parameters over tomato fruit development.

Auxin is known to be involved in all the stages of fruit development. Aux/IAAs are regulators of the auxin signaling at the transcription level. In a recent study, using RNAi strategy to limit the expression Sl-IAA17, it was shown that this tomato AuxIAA regulates fruit size mainly through altering the ploidy level of pericarp cells. Indeed, Sl-IAA17 down-regulated lines showed fruit with larger diameter, bigger volume and heavier weight than wild-type. The increase in fruit size was associated with thicker pericarp rather than larger locular spaces. The thicker pericarp was linked to larger cells harboring higher ploidy level, probably due to more active endoreduplication at the beginning of fruit development. The present report describes some additional phenotypes, not described in the initial article, among which are soluble solid content, juice pH, firmness, seed weight and fruit morphology.

[Delayed tamponade and traumatic myocardial contusion: evaluate the risk after blunt chest trauma]. / Tamponnade tardive et contusion myocardique: un risque à évaluer après un traumatisme thoracique fermé

Cardiac contusion is frequently found in patients with blunt chest trauma. It is important to note that even if there is a low incidence of pericardial effusion, iterative echocardiography should be used to provide essential information for the diagnosis of cardiac tamponade which can be life-threatening during hospitalisation. The case has been reported of a 17-year-old patient with blunt thoracic trauma in whom the introduction of anticoagulant treatment induced a delayed cardiac tamponade with myocardiac failure 3 weeks after a cardiac contusion. Thoracic computed tomography confirmed the diagnosis and moreover, revealed a pleural effusion with pulmonary embolism. The drainage of the pericardial effusion (700 ml) rapidly restored haemodynamic stability and as such has been proved to be life-saving.

A new simple technique for the insertion of cuffed central venous catheters: an initial experience.

BACKGROUND: Although tunneled polyurethane catheters with polyester cuffs are useful when prolonged central venous access is necessary but their insertion still remains challenging at times. We report the first study of a new cuffed polyurethane catheter (Seldicuff) that can be easily inserted using the Seldinger technique without the need of a vein dilator and that incorporates a tunneling needle onto the catheter. A Seldicuff catheter was placed in 15 patients (mean age: 53 +/- 11 years) who required prolonged parenteral nutrition. All catheters were inserted into the right subclavian vein. The procedure lasted 6.4 +/- 0.8 minutes and no complication directly related to catheter placement was noted. Catheters remained in position for a mean duration of 103 days (range, 58 to 220 days). During this period, no infectious or mechanical complications were observed. CONCLUSION: These results demonstrate that placement of this novel cuffed catheter is as simple as inserting a conventional central venous catheter.

Intrathecal baclofen after traumatic brain injury: early treatment using a new technique to prevent spasticity.

BACKGROUND: In the early course of severe head trauma, the clinical value of intrathecal administration of baclofen to reduce autonomic disorders and spasticity has not been established. METHODS: We studied four patients (Glasgow Coma Scale score 3 or 4) with autonomic disorders and spasticity who failed to respond to conventional treatment during the early course of head injury. Baclofen (25 microg/mL) was infused continuously through an intrathecal catheter inserted at patient bedside and subcutaneously tunneled. When this treatment was successful, the spinal catheter was removed and surgically replaced by another catheter connected to a subcutaneous pump. Clinical follow-up was obtained at 6 months after the head injury. RESULTS: Mean delay for the initiation of intrathecal baclofen was 25 days (range, 21 to 31 days), and optimal dose was 385 +/- 185 microg/day. In all patients, the Ashworth score was consistently reduced (3.5 +/- 0.5 vs. 4.5 +/- 0.5 for upper limbs and 2 +/- 0.5 vs. 4.5 +/- 0.5 for lower limbs), as were both the frequency and intensity of autonomic disorders. The spinal catheters were used during a mean period of 9.5 +/- 1.7 days without complications. All three survivors were equipped with a programmable pump and had a lower Ashworth score at 6 months. Autonomic disorders had disappeared in two patients and remained modest in the remaining patient. CONCLUSION: Continuous administration of baclofen via the intrathecal route using this new technique seems to reduce autonomic disorders and spasticity during the early course of severe traumatic head injury.

[A rare cause of sudden death in young adults with "normal" heart: the Brugada syndrome]. / Une cause rare de mort subite de l'adulte jeune à "coeur normal": le syndrome de Brugada.

BACKGROUND: Brugada syndrome is a rare condition causing sudden death in young adults due to unexpected sudden-onset ventricular fibrillation. Diagnosis is based on the presence of an ST depression in the anteroseptal territory and a right branch block. No underlying dysrhythmic condition or arrhythmogenic heart disease can be detected. CASE REPORT: A 15-year old boy with an uneventful past history experienced cardiocirculatory failure due to ventricular fibrillation during a sports competition. Cardiac arrest developed and resuscitation was initially successful but death ensued due to cerebral anoxia. Characteristic electrocardiographic signs and the presence of similar anomalies in a brother and an aunt led to the diagnosis of Brugada syndrome. DISCUSSION: Brugada syndrome is a recently discovered hereditary condition with a probably underestimated prevalence. Systematic family studies have demonstrated autosomal dominant inheritance. The characteristic electrocardiographic anomalies can be transitory and may be unmasked by sensitivization tests. The only currently effective treatment is the implantable defibrillator programmed to prevent sudden death by ventricular fibrillation.

Changes in breathing pattern and respiratory muscle performance parameters during difficult weaning.

OBJECTIVE: This study examined, using noninvasive means, the changes in breathing pattern and inspiratory muscle pressure-time indices during difficult progressive withdrawal of pressure-support ventilation. DESIGN: A prospective analysis of the temporal evolution of several respiratory variables in difficult-to-wean patients. SETTING: A university hospital intensive care unit. PATIENTS: A heterogeneous group of 17 patients receiving prolonged mechanical ventilation. INTERVENTIONS: Daily measurements of breathing pattern and respiratory muscle performance parameters in difficult-to-wean patients. MEASUREMENTS AND MAIN RESULTS: We examined breathing pattern variables, rapid shallow breathing (respiratory rate/tidal volume), tracheal occlusion pressure, maximal inspiratory pressure (P(I)max), and the tension-time index of the inspiratory muscles (TTmus = P(I)/P(I)max x Ti/Ttot) (where Ti/Ttot is inspiratory fraction of the cycle). All measurements were repeated at 24-hr intervals throughout the difficult weaning period. The patients were extubated on satisfying ten of 12 classical weaning criteria. Eleven patients were successfully weaned from mechanical ventilation while six patients were not. Weaning failure was associated with the following: a) longer periods of mechanical ventilation before weaning; b) high values of tracheal occlusion pressure, respiratory rate, minute ventilation, and effective impedance maintained throughout the difficult weaning period; and c) persistent high PaCO2 and intrinsic positive end-expiratory pressure values. As the weaning failure patients' inspiratory muscles confronted an increasing inspiratory load, values of the tension-time index of the inspiratory muscles entered or remained in the fatigue zone. In contrast, weaning success patients normalized their breathing pattern and decreased their tracheal occlusion pressure, effective impedance, and tension-time index values. CONCLUSIONS: Breathing pattern alterations and respiratory muscle performance impairments lead to ventilator dependency after prolonged mechanical ventilation. The measurement of variables such as the noninvasive tracheal occlusion pressure, inspiratory power of breathing, and tension-time index of the inspiratory muscles facilitate the management of difficult-to-wean patients.

A novel NADPH-dependent aldehyde reductase gene from Vigna radiata confers resistance to the grapevine fungal toxin eutypine.

Eutypine, 4-hydroxy-3-(3-methyl-3-butene-1-ynyl) benzyl aldehyde, is a toxin produced by Eutypa lata, the causal agent of eutypa dieback of grapevines. It has previously been demonstrated that tolerance of some cultivars to this disease was correlated with their capacity to convert eutypine to the corresponding alcohol, eutypinol, which lacks phytotoxicity. We have thus purified to homogeneity a protein from Vigna radiata that exhibited eutypine-reducing activity and have isolated the corresponding cDNA. This encodes an NADPH-dependent reductase of 36 kDa that we have named Vigna radiata eutypine-reducing enzyme (VR-ERE), based on the capacity of a recombinant form of the protein to reduce eutypine into eutypinol. The strongest homologies (86.8%) of VR-ERE at the amino acid level were found with CPRD14, a drought-inducible gene of unknown function, isolated from Vigna unguiculata and with an aromatic alcohol dehydrogenase (71.7%) from Eucalyptus gunnii. Biochemical characterization of VR-ERE revealed that a variety of compounds containing an aldehyde group can act as substrates. However, the highest affinity was observed with 3-substituted benzaldehydes. Expression of a VR-ERE transgene in Vitis vinifera cells cultured in vitro conferred resistance to the toxin. This discovery opens up new biotechnological approaches for the generation of grapevines resistant to eutypa dieback.

Expression of an antisense 1-aminocyclopropane-1-carboxylate oxidase gene stimulates shoot regeneration in Cucumis melo.

The role of ethylene in shoot regeneration was investigated using transgenic Cucumis melo plants expressing an antisense 1-aminocyclopropane-1-carboxylate (ACC) oxidase gene. ACC oxidase catalyses the last step of ethylene biosynthesis. Leaf and cotyledon explants from the transgenic plants exhibited low ACC oxidase activity and ethylene production, whereas the regeneration capacity of the tissues was greatly enhanced (3.5- and 2.8-fold, respectively) compared to untransformed control tissues. Addition of ethylene released by 50 or 100 µM 2-chloroethylphosphonic acid dramatically reduced the shoot regeneration rate of the transgenic tissues. The results clearly demonstrate that ethylene plays an important role in C. melo morphogenesis in vitro.

Modulation of glycerol and ethanol yields during alcoholic fermentation in Saccharomyces cerevisiae strains overexpressed or disrupted for GPD1 encoding glycerol 3-phosphate dehydrogenase.

The possibility of the diversion of carbon flux from ethanol towards glycerol in Saccharomyces cerevisiae during alcoholic fermentation was investigated. Variations in the glycerol 3-phosphate dehydrogenase (GPDH) level and similar trends for alcohol dehydrogenase (ADH), pyruvate decarboxylase and glycerol-3-phosphatase were found when low and high glycerol-forming wine yeast strains were compared. GPDH is thus a limiting enzyme for glycerol production. Wine yeast strains with modulated GPD1 (encoding one of the two GPDH isoenzymes) expression were constructed and characterized during fermentation on glucose-rich medium. Engineered strains fermented glucose with a strongly modified [glycerol] : [ethanol] ratio. gpd1delta mutants exhibited a 50% decrease in glycerol production and increased ethanol yield. Overexpression of GPD1 on synthetic must (200 g/l glucose) resulted in a substantial increase in glycerol production ( x 4) at the expense of ethanol. Acetaldehyde accumulated through the competitive regeneration of NADH via GPDH. Accumulation of by-products such as pyruvate, acetate, acetoin, 2,3 butane-diol and succinate was observed, with a marked increase in acetoin production.

Serotonin syndrome due to an overdose of moclobemide and clomipramine. A potentially life-threatening association.

The serotonin syndrome is frequently characterized by minor neurologic manifestations that regress rapidly (such as confusion, tremor, ...). Many medications including tricyclic antidepressants, serotonin reuptake inhibitors, tryptophan and the association of monoamine oxidase inhibitors together with a serotoninergic agent have been implicated in this syndrome. In certain cases, and for poorly understood reasons, clinical manifestations can include circulatory collapse, malignant hyperthermia, convulsions and rhabdomyolysis. These forms are often fatal. Treatment, other than the withdrawal of the offending drug, is symptomatic. Dialysis may be of value in withdrawing the drug from the circulatory system. We report a patient with the serotonin syndrome of favorable outcome due to an overdose of moclobemide and clomipramine.

Protonophoric activity of eutypine, a toxin from Eutypa lata, in plant mitochondria.

Eutypine is a toxin produced by Eutypa lata, the causal agent of the dying-arm disease of grapevine. We have previously shown that this toxin behaves as a lipophylic weak acid (pK = 6.2) and induces drastic changes in both the respiration and energy balance of grapevine cells. In the present study, the molecular mode of action of eutypine at the mitochondrial level, using methyl-eutypine, the unprotonable derivative of the toxin, has been investigated. The effects of these molecules on mitochondrial respiration and membrane potential were compared using isolated mitochondria from grapevine cells in suspension cultures or potato tuber mitochondria. Eutypine induces marked stimulation of oxygen consumption and a depolarizing effect, while methyl-eutypine exhibits a very small effect on both the rate of oxygen uptake and membrane potential. For high eutypine concentrations, a mixed effect corresponding to a direct inhibition of electron transport and uncoupling can be observed. In addition, below 200 microM, eutypine displays a linear relationship between oxidation rate and membrane potential similar to that of the classical protonophore carbonyl cyanide-m-chlorophenylhydrazone (CCCP). However, unlike CCCP, eutypine induces a potential-dependent proton conductance that can be due to the potential-dependent migration of the dissociated form of the toxin across the membrane. It is concluded that eutypine uncouples mitochondrial oxidative phosphorylation and decreases the ADP/O ratio in grapevine cells by increasing the proton leaks via a cyclic protonophore mechanism. The physiological aspects of these results are discussed.

Expression of ACC oxidase antisense gene inhibits ripening of cantaloupe melon fruits.

The plant hormone ethylene plays a major role in the ripening of climacteric fruit. We have generated transgenic cantaloupe Charentais melons expressing an antisense ACC oxidase gene; ACC oxidase catalyzes the last step of ethylene biosynthesis. Ethylene production of transgenic fruit was < 1% of control untransformed fruit, and the ripening process was blocked both on and off the vine. The antisense phenotype could be reversed by exogenous ethylene treatment. Analysis of antisense ACC oxidase melons indicated that the ripening process includes ethylene-dependent and ethylene-independent pathways. Because the transgenic line we generated displays extended storage life and improved quality, it has a promising potential for commercial development.

Genetic analysis of organogenesis in the cotyledons of zygotic embryos of sunflower (Helianthus annuus L.).

Crosses were made between five cytoplasmic male-sterile and five restorer sunflower inbred lines. Twenty-five F1 hybrids and their parents were studied for their organogenesis ability in a randomized block design with four replications. Each replication per genotype consisted of ten petri dishes with four expiants. Regeneration medium consisted of full MS medium modified by the addition of hormones and solidified with 6 g/l agar. Statistical analysis showed that both general and specific combining abilities were significant for all of the organogenesis parameters studied, and both showed several significant positive or negative values. General combining ability values were usually higher than those of specific combining ability, indicating the importance of additive genetic control for organogenesis parameters in sunflower. Narrow-sense heritability for the number of explants producing shoots and roots was 65.8%, which suggests that organogenesis of currently inferior inbred lines in sunflower should be improved in a crossing program.

Occlusion pressure and its ratio to maximum inspiratory pressure are useful predictors for successful extubation following T-piece weaning trial.

STUDY OBJECTIVE: In most weaning studies, failure group patients are reventilated prior to extubation, thus compromising the evaluation of the applied weaning indices' predictive values. This study determines the usefulness of both standard and recent indices in predicting successful extubation following prolonged mechanical ventilation. DESIGN AND METHODS: Following a successful 20-min T-piece trial, ten traditional weaning criteria, as well as airway occlusion pressure (PO.1), maximal inspiratory pressure (MIP), PO.1/MIP ratio, and shallow breathing (F/VT) were determined in unselected patients undergoing prolonged mechanical ventilation. Having satisfied 8 of 10 classic weaning criteria, 67 patients were extubated after an additional 40 min of successful spontaneous T-piece breathing, and included in the study. After extubation, the tracheal tube resistive pressure (RP) values were measured. RESULTS: Twelve (18%) patients failed extubation. The failure group's average age was significantly greater (69.43 vs 48.43 years). The PO.1, PO.1/MIP, and F/VT values of the success (3.62 +/- 1.35 cm H2O, 0.05 +/- 0.04, and 50 +/- 23 b.min-1.L-1) and failure (7.38 +/- 2.67 cm H2O, 0.14 +/- 0.04, and 69 +/- 25 b.min-1.L-1) groups were significantly different (p < 0.005). The diagnostic accuracies of these indices were, respectively, 88%, 98%, and 73%. The spirometric, gas exchange, and tracheal tube RP values of the two groups showed no significant differences. CONCLUSION: PO.1 and PO.1/MIP ratio provide the best means of predicting extubation success, and they are not influenced by tracheal tube resistance.

[Bongaarts: a model of fertility and its application to Spain]. / Bongaarts: un modelo de fecunididad y su aplicacion en Espana.

PIP: The author describes the Bongaarts model and applies it to data from a 1985 national fertility survey undertaken in Spain. The focus is on evaluating the model's explanatory power and validity. (SUMMARY IN ENG AND FRE)^ieng

[High frequency jet ventilation combined with conventional mechanical ventilation in the treatment of adult respiratory distress syndrome]. / Jet ventilation à haute fréquence combinée à la ventilation mécanique conventionnelle dans le traitement du SDRA.

Better understanding of the physiopathology of ventilatory mechanisms associated with ARDS and the recent re-evaluation of the iatrogenic potential of mechanical ventilation (MV) brings us closer to the best suited ventilatory mode for these patients. In severely ill ARDS patients, only a small lung volume is ventilated, and remains available for the totality of the gas exchanges (baby lung concept). The goal of MV is to restore and maintain an optimal exchange volume while limiting mechanical agression of the lung tissue. Analysis of the ARDS related pressure-volume relationship (P/V) is helpful in specifying the tolerable limits of the ventilatory pressure regimen. The lower limit (end expiratory pressure) must be kept above the lower inflexion point of the curve, in order to increase the ventilated lung volume and avoid distal airway collapse. Under this limit, gas exchanges are altered by the shunt effect, and shear stress lesions result from the repeated opening and closing of the distal airways. The upper limit (end inspiratory pressure) must be situated below the upper inflexion point of the curve, in order to avoid lesions resulting from surdistension of the alveolocapillary membranes and barotraumatisms. The only way to position MV in such a narrow pressure window, is to greatly reduce the tidal volume (VT). Though CO2 retention would inevitably occur under conventional MV conditions, high frequency ventilation (HFV) seems better adapted to these theoreotical objectives; small VT's are injected under a limited amplitude pressure regimen and a satisfactory CO2 clearance is maintained. This ventilatory mode, existing since more than 15 years, has recently benefited from many technical improvements as well as the concept of oscillating the ventilation around a selected mean pressure in the central region of the P/V curve. In the past, HFV was applied using low pressure regimens, situated below the lower inflexion point of the curve. The resulting failures are, a posteriori, explained by insufficient lung volumes, unable to maintain adequate gas exchanges. Current work is aimed at re-evaluating HFV, using higher mean airway pressure levels. Combined HFV is another advance towards the theoretical goal of restoring and maintaining optimally ventilated lung volumes. Though HFV alone can maintain lung volumes oscillating around a mean value, it cannot re-expand atelectatic areas. The small VT's used are insufficient to overcome these area's elevated opening pressures. Volume recruitment by periodic hyperinflations, or sighs, though generally considered useless in conventional MV, have been shown to be of great benefit in HFV.(ABSTRACT TRUNCATED AT 400 WORDS)

Bronchoalveolar lavage for diagnosing bacterial pneumonia in mechanically ventilated patients.

To assess the usefulness of BAL in diagnosing bacterial pneumonia in mechanically ventilated patients, 80 BAL fluid samples obtained from 72 patients with lung infiltrates were studied using the following parameters: infected cell count (polymorphonuclear leukocytes or macrophages with intracellular organisms), microscopic examination of stained smears, and quantitative culture with the determination of the simplified bacterial index (SBI) and the predominant species index (PSI). Of the 80 BAL samples studied, 56 were performed under antibiotic therapy. Bacterial pneumonia was the final diagnosis in 28 cases. The SBI is the sum of the whole numbers of each bacterial concentration expressed as a common logarithm. The PSI is the whole number of the predominant microorganism's concentration expressed as a common logarithm. The discriminative value of each test was assessed using a receiver operating characteristic (ROC) curve, whereby the possibility of establishing a cutoff value used to discriminate between the presence or absence of pneumonia is evaluated. The percentage of infected cells was higher in the pneumonia group (8.8 +/- 18.1 versus 0.4 +/- 1.1%, p < 10(-3), but no cutoff value could be proposed. Under microscopic examination, the presence of bacteria was noted with a significantly greater frequency in the pneumonia group (sensitivity 67.8% and specificity 82.7%). A total of 58 BAL samples were positive when cultured. The SBI was significantly higher in the pneumonia group (6.5 +/- 2.9 versus 1.6 +/- 1.7, p < 10(-4).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of hydrophobic heat and moisture exchangers with heated humidifier during prolonged mechanical ventilation.

Inspired gases must be warmed and humidified during mechanical ventilation. In a prospective randomized study we compared the performance of a heated humidifier (HH) (Draegger Aquaport) and a heat and moisture exchanger (HME) (Pall Filter BB 2215). A total of 116 patients requiring mechanical ventilation (Servo 900 C Siemens) were enrolled into the study and were randomly assigned to 2 groups. Patients in group I were ventilated with a traditional breathing circuit with HH and patients in group II using a simplified circuit with HME. Pre-existing and hospital acquired atelectasis and pneumonia, occurrence of endotracheal tube (ET) occlusion and ventilatory parameters (respiratory rate, tidal volume) were studied. No statistical difference was found between groups for each parameter except the greater frequency of ET occlusions in the II group (0/61 vs 9/55) (p = 0.0008). Pall Filter (PF), a hydrophobic filter, humidifies the dry gases from the condensed water which is put down on the HME surfaces during cooling of saturated expired gases. This purely physical property is linked to the magnitude of the thermic gradient between the expired gases and the ambiant temperature. Performance impairment of PF in our study might be due to high ambiant temperature in the intensive care unit (usually around 28 degrees C) which reduces thermic gradient and water exchanges. We conclude that efficiency of PF may be weak in some conditions of ambiant temperature.

Enhancement of shoot regeneration potential by liquid medium culture from mature cotyledons of sunflower (Helianthus annuus L.).

We describe here a liquid culture system for the regeneration of shoots at high frequencies from mature cotyledon tissues of three genotypes of sunflower (Helianthus annuus L.) one of which had previously been found to be recalcitrant to regeneration when cotyledons were cultured on solid medium. Cotyledons were excised from 2-day-old seedlings and incubated in liquid Murashige and Skoog's modified medium supplemented with 5.4 µM naphthaleneacetic acid (NAA) and 4.4 µM benzylaminopurine (BAP). After two weeks in culture, the whole upper surface of regenerating explants was covered with green shootlets. The percentages of regenerating explants of three genotypes varied between 60 and 70%, and the number of shoots per regenerating explant was highly increased. The shootlets were transferred to solid Murashige and Skoog's medium allowing shoot development, then to rooting medium. Rooted plantlets were successfully acclimatized and gave fertile plants. The role of liquid medium culture in the induction of sunflower regeneration is discussed.