Diurnal variation in total plasma tryptophan in controls and in depression.

Circadian rhythms of total tryptophan were investigated by assays of hourly blood samples over 25 h. The study population consisted of four endogenously depressed patients investigated in the absence of any treatment and six healthy controls. The abnormalities detected by statistical analyses in untreated depression consisted mainly of amplitude reduction; the phase positions of the depressed patients were similar to those of the controls.

Short-term effect of cold provocation on single-breath carbon monoxide diffusing capacity in subjects with and without Raynaud's phenomenon.

The lung diffusing capacity for carbon monoxide was determined by the single breath method (DLCOsb) before, during, and after immersion of the left hand in cold water in four groups of subjects: (i) normal individuals; (ii) subjects with idiopathic Raynaud's disease; (iii) patients with progressive systemic sclerosis without associated Raynaud's phenomenon; and (iv) patients with connective tissue disease associated with Raynaud's phenomenon. Our results showed significant differences in the evolution of DLCOsb after cold stimulation between the groups. Control subjects (group one) showed a transient but significant reduction in DLCOsb at the end of two minutes of cold stimulation, normalizing ten minutes later. Subjects with primary Raynaud's phenomenon (group two) showed on the contrary a transient but significant rise in DLCOsb after 2 minutes, while subjects with an isolated connective tissue disease without Raynaud's phenomenon (group three) showed a significant decrease in DLCOsb at both observation times. Patients with Raynaud's phenomenon associated with a connective tissue disease (group four) showed a delayed decrease in DLCOsb ten minutes after cold stimulation. This latter result appeared as an addition to the effects of cold stimulation observed in groups two and three.

Effects of feeding time upon daily intake and body weight.

Feeding behavior in five dogs was studied in three experimental situations, called A, B and C. In situation A the dogs had free access to food and water. Results from this experiment were used to determine the times of high and low ingestion for each individual dog. In situation B, there was limited access to food during the dog's period of high ingestion, and in situation C there was limited access to food during periods of low ingestion. Daily food intake was found to diminish as the dogs proceeded from A and B to C, and was especially pronounced between A and C. Body weight also diminished significantly between A and C.

[Rhythmic patterns of food and water intake in the dog: preliminary study (author's transl)]. / Rythmes spontanés des prises alimentaire et hydrique chez le chien: etude préliminaire

The spontaneous rhythmic patterns of food and water intake in the dog during periods of 24 hr have been studied under three experimental conditions: natural light, continuous light and artificial light with day and night sequences. Under natural light there is a rhythmic pattern in the frequency of food intake and the amount of food consumed. During the night, periods of food consumption are numerous and the amount of food ingested is significant. During the day both the number of periods of food intake and the amount of food consumed is less. Similar results were obtained under continuous light. Under artificial light, with day and night sequences, there is a tendency to equalize the amount of food consumed through the 24 hr. This produced a displacement of frequency curves. In these three situations there seems to be an important relationship between the amount of food consumed and the time intervals following periods of food intake. Generally, similar results were obtained for water intake.

Circadian rhythms in depression and recovery: evidence for blunted amplitude as the main chronobiological abnormality.

Circadian rhythms of body temperature, plasma cortisol, norepinephrine (NE), thyroid stimulating hormone (TSH), and melatonin were compared in 16 endogenously depressed, 15 recovered (after 3 weeks of anti-depressant treatment), and 16 normal subjects. The depressed patients showed clear circadian rhythm abnormalities, consisting mainly in amplitude reduction. This amplitude reduction was significantly correlated with the patients' Hamilton depression scores. Normal circadian profiles were restored after recovery when amplitude, in particular, was increased. Features of the circadian rhythms observed in remission may be associated with antidepressant drug effects, whereas those observed in depression resemble the circadian rhythms observed in normal subjects living under conditions of temporal isolation and those of blind subjects. Our findings suggest that depression may be related both to a weakening of the coupling processes between internal pacemakers and to an abnormal sensitivity to environmental information.

Circadian rhythm in plasma noradrenaline of healthy sleep-deprived subjects.

Under normal sleep-wake conditions, noradrenaline (NA) secretions in supine subjects exhibit a weak circadian variation with a peak that occurs around noon; the sleep span is characterized by reduced NA secretion. Some investigators have reported that the circadian NA rhythm is completely obliterated during sleep deprivation. In our laboratory, plasma NA was assayed every hour for 24 h in nine healthy men 20-23 years of age. All men were deprived of sleep and were required to eat and walk around every hour to prevent sleep. However, subjects remained supine for 20 min before blood samples were collected to eliminate the effect of activity. Persistence of a slight decrease in the night concentration in several subjects, despite sleep deprivation, suggests that NA secretion may be influenced by a biological clock whose activity becomes visible when the influence of posture is removed.

Influences de la castration et du propionate de testosterone sur le comportement des rats conditionnes par paires.

Four groups of 10 male rats (Group A: normal rats, Group B: castrated rats, Group C: castrated rats + 1 mg P.T./day, Group D: castrated rats + 1 dose of 50 mg/kg of P.T. cyclohexane) were avoidance conditioned during nine sessions of 50 trials. They were conditioned individually during sessions 4, 5 and 6 and by pairs during sessions 1, 2, 3, 7, 8 and 9. During these last sessions, all groups presented a low level of acquisition and aggressive behaviour. These phenomena were worsened in the castrated rats whose performances stayed low even when they were conditioned individually. On the other hand, the frequency of their aggressive behaviour was often higher than that of the other groups. The injection of P.T. cyclo-hexane improves the performance of the castrated animals but does not entirely compensate for the differences between control and experimental rats.

[Inefficacy of theophylline in preventing hypoxemia in abdominal surgery]. / Inefficacité de la théophylline dans la prévention de l'hypoxémie en chirurgie abdominale.

It would be very useful to prevent post surgery ventilatory and gazometric insufficiencies that represent a significant risk factor. Ten patients have received proper doses of theophyllin in order to maintain accurate plasmatic concentration immediately after surgery. During the next 24 hours, their respiratory frequency, tidal volume, ventilation per minute, PaO2 and PaCO2 have been recorded. Those data have been compared with a test group (N = 10) having received injections of placebo. No relevant discrepancy exists in the ventilation parameters nor any increase of PaO2. The significant factor is a substantial decrease of PaCO2. It appears that theophyllin has no significatory efficiency for controlling the post surgery hypoventilation and hypoxemia.

[Acid-base changes across the rat jejunum, in vitro (author's transl)]. / Modification des équilibres acido-basiques par le jéjunum de rat, in vitro.

Everted sacs of rat jejunum are able to adjust to near 6.5 any solution whose pH is situated between 5.5 and 9.5. Beyond these limits the adjustment becomes incomplete. Changes in PCO2 and total CO2 associated with changes in mucosal pH-values suggest that bicarbonate or CO2-movements toward the jejunal lumen involved in this adjustment process are predominant.

[Effect of pH on the motility of isolated jejunal loops in dogs]. / Action du pH sur la motilité d'une anse jéjunale isolée chez le chien.

Thirty-Vella jejunal loops are perfused at a constant rate with solutions of variable pH (1.55-11.25). Net loop absorption and motility of the oral segment do not significantly vary between pH values of 2.2 to 10.0. At a more acid pH, there exists a strong increase in the amplitude of pressure waves accompanied by a decrease in their frequence.

[Cardiac adaptation in highly skilled swimmers and soccer player: a vectorcardiographic approach]. / Adaptation cardiaque chez des nageurs et des footballeurs de haut niveau : approche vectorcardiographique.

Nine swimmers and nine soccers have been studied by the mean of Frank lead vectorcardiographic system. According to classical criteria, both the two groups present similar marked left ventricular hypertrophy. Numerous indices suggest that right ventricular hypertrophy is also associated though more important for the swimmers. The assumption of volume overload because of special hemodynamic conditions during swimming is proposed.

[Synchronous electric activity with inspiration in the vastus lateralis muscle of the anesthesied dog breathing spontaneously]. / Activité électrique synchrone avec l'inspiration dans le muscle vaste externe du Chien anesthésié respirant spontanément

In the dog, under chloralose or pentobarbitone anesthesia and breathing spontaneously, a muscular electrical activity of low voltage synchronous with respiration was observed in m. vastus lateralis. The mean maximum amplitude of this activity is inversely linked with respiratory rate. When the respiratory frequency is equal or exceeds 25 cycles per minute this activity disappears. Such a phenomenon seems to be related to the activity of the respiratory centre.

[Respiratory stimulant effect of S 2620 in the dog anesthetized with pentobarbital]. / Action stimulante respiratoire du S 2620 chez le chien anesthésié au pentobarbital

In the dog under pentobarbitone anesthesia, the intravenous injection of 1 mg/kg S 2620 is followed by a significant increase in respiratory rate, PaO2 and pHa and by a large decrease in PaCO2. Cervical vagotomy and chemoreceptor denervation reduced and even abolished these effects. They can be induced again by a second intravenous injection or by direct instillation in the fourth ventricle. These results suggest a central action of the drug.

[Influence of eating modalities on water intake in dog (author's transl)]. / Incidences des modalités d'alimentation sur la prise d'eau chez le chien

Food and water intake of a dog which had free access to water were studied in three experimental circumstances: 1) Food given ad libitum. 2) Food given at fixed hours. 3) Food deprivation for four days followed by resumption of food intake. A) The results indicate the water intake follows a pattern, the profile, range and duration of which can be modified within 24 hrs. In spite of modifications related to food intake, a typical profile remains which suggests that water is taken according to a program which is at least partly indepdent of food intake. B) Under experimental condition 1, food and water intake were weakly related, probably revealing an acquired relationship between the meal weight and the water intake which immediately precedes and follows food intake. The correlation was strengthened when the dog was forced to eat only once a day (observation 2). On the contrary, after a period of starvation (observation 3) the previous relationship between meal weight and water intake lessens and others appear which suggest the action of direct mechanisms of shortage compensation as far as water and food are concerned.

[Cardiovascular effects of S 2620 in dogs anesthetized with pentobarbital]. / Propriétés cardio-vasculaires du S 2620 chez le chien anesthésié au pentobarbital.

In the dog under pentobarbitone anesthesia, the intravenous infusion of 1 mg/kg S 2620 results in tachycardia and systemic arterial hypertension. The same attenuated effects are caused by a second injection of the drug after cervical vagotomy and chemoreceptors denervation. Tachycardia and peripheral vaso constriction can account for elevation of arterial pressure.