Comparative expression analysis of the antagonistic transcription factors EVI1 and MDS1-EVI1 in murine tissues and during in vitro hematopoietic differentiation.

An alternative form of the transcription factor EVI1, MDS1-EVI1, which previously had been believed to exist only in the context of leukemic fusion mRNAs, has recently been shown to be expressed also in normal human tissues. Moreover, it acts as an antagonist of EVI1, activating transcription of reporter constructs repressed by EVI1. We cloned the murine homolog of MDS1-EVI1 as well as mMds1 and show localization of mMds1 close to mEvi1 on chromosome 3. Using RT-PCR, we demonstrate widespread expression of both Evi1 forms in the adult mouse, as well as their upregulation during in vitro hematopoietic differentiation. Our data underscore the biological importance of both EVI1 and MDS1-EVI1 and provide the basis for further studies of their function in the mouse model system.

Arabidopsis thaliana RAD6 homolog AtUBC2 complements UV sensitivity, but not N-end rule degradation deficiency, of Saccharomyces cerevisiae rad6 mutants.

AtUBC2 of Arabidopsis thaliana encodes a structural homolog of the RAD6 gene of Saccharomyces cerevisiae with approximately 65% identical amino acids. Like structural homologs from other organisms, AtUBC2 lacks the carboxyl-terminal extension of mostly acidic amino acids which is present in Rad6p. AtUBC2 was expressed in S. cerevisiae rad6 mutants. It was found to partially complement the UV sensitivity and reduced growth rate of rad6 mutants at elevated temperatures. AtUBC2 however, has no apparent influence on the degradation of N-end rule substrates in the heterologous host.

[Comparison between left and right humeral arterial pressure. Indirect measurement with an automatic apparatus]. / Comparaison des pressions artérielles humérales droites et gauches. Mesure indirecte avec un appareil automatique.

Is humeral blood pressure identical in the right arm and left arm? We attempted to answer this question by simultaneous measurement of pressure on each side by a semi-automatic indirect method. Results were analysed by the linear regressions method. This study showed that it is possible to estimate the pressure on one side on the basis of a measurement made on the opposite side. The accuracy of this estimation is +/- 10 mmHg regarding the blood pressure of a given individual and is +/- 4 mmHg in terms of the mean blood pressure of the population in general. Thus, provided there is no anatomical abnormality of the arterial system, it would seem to make no difference if blood pressure is measured on the left side or right side.

[Effects of medullary pyramidal stimulation on myocardial contractility in anesthetized dogs]. / Effets de la stimulation des pyramides bulbaires sur la contractilité myocardique chez le chien narcosé.

In anaesthetized dogs, medullary pyramid stimulation produces a decrease of myocardial contractility. The peak of the first derivative of the left ventricular pressure (dP/dt max) was used to assess myocardial contractility; this index is independent of afterload. Medullary pyramid stimulation produces a decrease of dP/dt max and of the maximal left ventricular pressure (L.V.P. max) also, after bilateral vagotomy. But the same stimulation induces only a decrease of L.V.P. max after inhibiting beta-adrenergic efferences and bilateral vagotomy. Just as corticopyramidal fibres inhibiting alpha-adrenergic vascular tone, one does consider the existence of corticopyramidal fibres inhibiting beta-adrenergic efferences to myocardium.

[Assessment of cardiac output by a non-invasive method. Estimation of partial pressure of CO2 by rebreathing of expired gas. Comparison with thermodilution]. / Mesure du débit cardiaque par une méthode non agressive. Estimation de la pression partielle de CO2 par réinhalation du gaz expiré. Comparaison avec la thermodilution.

The cardiac output was measured in 65 patients by the FICK principle after estimation of the pp CO2 in mixed venous blood by rebreathing. This technique has been used mainly during exercise, and recently in intensive care units. We used it in resting patients hospitalised for diagnosis and treatment of a range of cardiac diseases, and in patients referred to our Physiological Laboratory. The reproductibility of our results using the rebreathing method was good: the variation of the individual results averaged 8.9%. The values of the cardiac output by rebreathing were compared to those obtained by thermodilution in 30 patients. A high coefficient of correlation was found: r = 0,897 (2p less than 0,001). This non-invasive technique is simple, rapid, and easily repeatible. Its use for serial estimations of the cardiac output should be retained.

[Periodic oscillating respiration outside of comatous stages]. / Respiration périodique oscillante en dehors d'états comateux

A periodic oscillating breathing was observed in 11 subjects during study of their pulmonary function. All these patients were male and more than 50 years old. A cardiovascular disease was clinically evident in eight of them. Arterial hypoxemia was found in five subjects and a light hypocapnia in three. Analysis of oscillating rhythms first, revealed unexistence of ventilatory pauses between periods of deep breaths in some subjects and secondly, showed existence of permanent or discontinuous periodic rhythms. Breath by breath changes in ventilation were essentially induced by oscillations in tidal volume. Discontinuous oscillating breathing appeared after forced maximal inspiration and this periodic rhythm was frequently associated with sights. This periodic breathing began or persisted under progressive hypoxia but disappeared under normobaric hyperoxia. These data are discussed in terms of changes in the ventilatory control system and in central regulation of breathing patterns.

[Effects of O2 inhalation on the partial arterial-alveolar pressure of CO2 in healthy patients and in patients suffering from chronic bronchitis (author's transl)]. / Effets de l'inhalation d'O2 pur sur la différence artério-alvéolaire de pression partielle de CO2 chez le sujet normal et le bronchiteux chronique.

The increase in arterial-alveolar CO2 difference (D[a-A]CO2) on 100% O2 breathing was studied in healthy subjects and in chronic bronchitic patients with or without hypoxemia. This increase in D(a-A)CO2 showing the enhancement of the dead-space effect (i.e. of the ventilation/perfusion ratio; VA/Q,), resulted from increase in PaCO2 or/and from decrease in PACO2 and was only found in hypoxic bronchitic subjects. In such subjects D(a-A)CO2 increased by about 50%. This phenomenon seems to arise from the vasomotor effect of pure O2 on pulmonary circulation and the role played by the Haldane effect in increasing PaCO2 and thus D(a-A)CO2 in some subjects is very weak. In subjects where inhalation of pure O2 produced the greatest increase in D(a-A)CO2 and in VA/Q, the calculated value of the venous admixture (QSh/QT) after measurement of D(A-a)O2 at the 30th min of hyperoxia was overestimated. Indeed D(A-a) O2 was enlarged by increasing the dead-space effect under 100% O2 breathing.