[Preoxygenation by high-flow nasal cannula in a patient with difficult ventilation and intubation criteria]. / Cas clinique. Préoxygénation par lunettes nasales à haut débit chez un patient présentant des critères de ventilation et d'intubation difficiles.

The different protocols and algorithms for difficult intubation highlight the need for early detection of patients at risk of ventilation and difficult intubation. These protocols allow an adaptation of the management and all conclude that an emergency trans-tracheal approach is necessary in case of impossible intubation. In this context, the prevention of hypoxemia must be a major concern of any anaesthetic management. Indeed, in case of an impossible orotracheal intubation, the occurrence of hypoxemia is directly correlated to the duration of apnea. Classically, preoxygenation maneuvers can significantly increase the duration of apnea without hypoxemia. Furthermore, apneic oxygenation maneuvers may be added in case of impossible ventilation but permeable laryngeal passage. This article reports on a patient with difficult intubation and ventilation criteria who benefitted from preoxygenation associated with apneic oxygenation via high flow nasal cannula.

Les différents protocoles et algorithmes d'intubation difficile mettent en avant la nécessité d'un dépistage précoce des patients à risque de ventilation et d'intubation difficiles. Ces protocoles permettent une adaptation de la prise en charge en concluant, tous, à la nécessité d'un abord trans-trachéal en urgence en cas d'intubation impossible. Dans ce contexte, la prévention des hypoxémies se doit d'être une préoccupation majeure de toute prise en charge anesthésique. En effet, en cas d'intubation orotrachéale impossible, la survenue d'une hypoxémie est directement corrélée à la durée de l'apnée. Classiquement, les manœuvres de pré-oxygénation permettent d'augmenter significativement la durée d'apnée sans hypoxémie. à celles-ci peuvent s'ajouter les manœuvres d'oxygénation apnéique en cas de ventilation impossible, mais avec une filière laryngée perméable. Cet article rapporte et discute le cas d'un patient présentant des critères d'intubation et de ventilation difficile qui a pu bénéficier d'une pré-oxygénation associée à une oxygénation apnéique par l'intermédiaire de lunettes nasales à haut débit.

Extraction and quantification of amino acids in human stratum corneum in vivo.

BACKGROUND: Amino acid (AA) levels in stratum corneum (SC) are potential biomarkers of skin health while their systemic levels may be used to diagnose inherited metabolic diseases. OBJECTIVES: To examine reverse iontophoresis, in human volunteers, as a minimally invasive tool to analyse AAs within the skin and subdermally. METHODS: In four volunteers, the amounts of iontophoretically extracted AAs were compared with those determined in the SC following repetitive tape stripping and with the plasma concentrations. Glucose levels, evaluated in the different compartments, were used as a control. RESULTS: SC concentrations of 13 essentially zwitterionic AAs were ∼100-fold higher than the respective plasma levels. Passive and reverse iontophoretic extraction for 4 h did not deplete the SC depot of AAs, a fact reinforced by postextraction tape stripping, which revealed that AAs remained in the SC at this time. In contrast, glucose was much less abundant in the SC and was fully and relatively quickly extracted by reverse iontophoresis. CONCLUSIONS: It follows that reverse iontophoresis is useful for quantifying AAs in the SC and these data are highly correlated with levels obtained by tape stripping. However, reverse iontophoresis is impractical for the routine monitoring of AA plasma concentrations (unlike the situation for glucose, the skin reservoir of which is much smaller).

The role of the 3' untranslated region in mRNA sorting to the vicinity of mitochondria is conserved from yeast to human cells.

We recently demonstrated, using yeast DNA microarrays, that mRNAs of polysomes that coisolate with mitochondria code for a subset of mitochondrial proteins. The majority of these mRNAs encode proteins of prokaryotic origin. Herein, we show that a similar association occurs between polysomes and mitochondria in human cells. To determine whether mRNA transport machinery is conserved from yeast to human cells, we examined the subcellular localization of human OXA1 mRNA in yeast. Oxa1p is a key component in the biogenesis of mitochondrial inner membrane and is conserved from bacteria to eukaryotic organelles. The expression of human OXA1 cDNA partially restores the respiratory capacity of yeast oxa1- cells. In this study, we demonstrate that 1) OXA1 mRNAs are remarkably enriched in mitochondrion-bound polysomes purified from yeast and human cells; 2) the presence of the human OXA1 3' untranslated region (UTR) is required for the function of the human Oxa1p inside yeast mitochondria; and 3) the accurate sorting of the human OXA1 mRNA to the vicinity of yeast mitochondria is due to the recognition by yeast proteins of the human 3' UTR. Therefore, it seems that the recognition mechanism of OXA1 3' UTR is conserved throughout evolution and is necessary for Oxa1p function.

Outbreak of tuberculosis among substance users and homeless people in Greater Montréal, Canada, 2003-2016.

BACKGROUND: In Canada, active tuberculosis (TB) is found mainly among migrants from endemic countries and Indigenous populations. However, cases of active tuberculosis in substance users and homeless persons have been reported in Greater Montréal since 2003. OBJECTIVE: To describe the Montréal TB outbreak in terms of the sociodemographic characteristics, risk factors and clinical characteristics of cases, as well as the intensity of public health interventions, the follow-up and identification of locations of potential transmission. METHODS: All cases of active tuberculosis with the same genotype of interest residing in Quebec and epidemiologically linked cases were included in the analysis. Data were retrospectively extracted from routine public health investigations. Characteristics of cases were summarized using Excel. Spatial analysis of locations frequented during cases' infectiousness periods was performed. RESULTS: Between January 2003 and February 2016 a total of 35 cases were identified. Most (86%) were non-Indigenous people born in Canada. Of these, 28 had several risk factors, including substance use (93%), alcohol abuse (64%), homelessness (46%), comorbidities such as HIV coinfection (36%) and advanced stage of the disease. Seven cases without risk factors were all close contacts of cases. Intensity of case management by public health authorities was high. Locations frequented by cases with risk factors included crack houses, shelters and rehabilitation centers in Montréal's downtown core and a residential setting in a suburban area. CONCLUSION: TB outbreaks can occur in marginalized Canadian-born urban populations, especially those with substance use. Tailored interventions in this population may be needed for screening, and earlier identification of both latent and active TB and better linkage to care.

Fall in blood glucose level precedes meal onset in free-feeding rats.

It has been suggested for a long time that the metabolic stimulation to eat or the hunger arousal of eating, originated from a fall in the blood glucose level induced by the periodic failure of hepatic glucose production to match the peripheral glucose uptake. However, this suggestion has not been substantiated directly by the results of periodic blood glucose evaluations performed during intermeal intervals in free-fed rats. In this experiment, a technique involving a continuous blood glucose determination over several hours was used in free-feeding, undisturbed rats. It was shown that all nocturnal and diurnal meals were preceded by a 6 to 8% fall of blood level, starting 5 to 6 min prior to meal onset. The overall consequences of these findings are discussed.

Palatability and preabsorptive insulin release.

The purpose of these experiments was to determine whether the level of orally-triggered and vagally-mediated preabsorptive insulin release was related to the degree of food palatability as measured by the amount of food necessary to produce satiation. Rats were habituated to a feeding schedule of five meals per day. During a test meal they were presented with one of 3 forms of their regular diet: unaltered, sweetened with Sucaryl sodium or adulterated with quinine hydrochloride. From 1.5 min preceding the meal to 19.5 min later, blood was continuously drawn via a chronic intravenous catheter. Blood was collected for regular intervals and immunoreactive insulin levels were determined. During the test meals, the rats ate 3, 4.9 and 1.5 g of the three diets, respectively. Within the first 3 min following meal onset, they exhibited a peak insulin release of 47, 65 and 25 microU/ml, respectively. Since this early insulin response disappeared long before the end of the meal, it was suggested that the palatability-dependent amount eaten could be affected by the palatability-modulated preabsorptive insulin release.

Cephalic phase responses to sweet taste.

The sweet taste of nonnutritive sweeteners has been reported to increase hunger and food intake through the mechanism of cephalic-phase insulin release (CPIR). We investigated the effect of oral sensation of sweetness on CPIR and other indexes associated with glucose metabolism using nutritive and nonnutritive sweetened tablets as stimuli. At lunchtime, 12 normal-weight men sucked for 5 min a sucrose, an aspartame-polydextrose, or an unsweetened polydextrose tablet (3 g) with no added flavor. The three stimuli were administered in a counterbalanced order, each on a separate day at 1-wk intervals. Blood was drawn continuously for 45 min before and 25 min after the beginning of sucking and samples were collected at 1-min intervals. Spontaneous oscillations in glucose, insulin, and glucagon concentrations were assessed as were increments (slopes) of fatty acid concentrations during the baseline period. The nature of the baseline (oscillations: glucose, insulin, and glucagon; and slopes: fatty acids) was taken into account in the analyses of postexposure events. No CPIR and no significant effect on plasma glucagon or fatty acid concentrations were observed after the three stimuli. However, there was a significant decrease in plasma glucose and insulin after all three stimuli. Only the consumption of the sucrose tablet was followed by a postabsorptive increase in plasma glucose and insulin concentrations starting 17 and 19 min, respectively, after the beginning of sucking. In conclusion, this study suggested that oral stimulation provided by sweet nonflavored tablets is not sufficient for inducing CPIR.

Metabolic and behavioral consequences of a snack consumed in a satiety state.

BACKGROUND: In view of the influence of dietary habits on obesity, human eating patterns merit study. OBJECTIVE: We investigated the behavioral and biological consequences of consumption of a 1-MJ snack by subjects in a satiety state. DESIGN: Eleven lean young men were deprived of time cues and subjected to continuous blood withdrawal over each of 4 sessions scheduled 2 wk apart. The first session was a basal session designed to determine the following in each subject: 1) the amount eaten in an ad libitum lunch; 2) the temporal patterns of plasma concentrations of glucose, insulin, fatty acids, and triacylglycerols between lunch and the spontaneous dinner request; and 3) the latency of the dinner request. In the 3 other sessions, each subject ingested the same lunch as in the basal session and a nutritionally well-balanced snack either 5 min before his individual peak of hyperglycemia observed in the first session, 40 min after this peak, or 120 min before the time he had requested his dinner in the first session. RESULTS: There was no significant difference in latency of the dinner request or the energy intake at dinner between sessions. Insulin secretion increased but glucose profiles did not change significantly regardless of the time of snack intake. CONCLUSION: A snack consumed in a satiety state fails to prolong the intermeal interval and would thus tend to favor storage.

Substrate oxidation and control of food intake in men after a fat-substitute meal compared with meals supplemented with an isoenergetic load of carbohydrate, long-chain triacylglycerols, or medium-chain triacylglycerols.

BACKGROUND: It has been suggested that hunger may be delayed and food intake reduced under metabolic conditions that spare carbohydrate oxidation. OBJECTIVE: Our objective was to examine the role of glucose metabolism in the control of food intake in men by using medium-chain triacylglycerols (MCTs) to spare carbohydrate oxidation. DESIGN: In 10 male volunteers, isolated and deprived of any time cues, we studied the effects of 4 lunches on hunger ratings, the duration of satiety, the amount of food ingested at dinner, energy expenditure, substrate oxidation, and plasma variables until the time of the dinner request. One lunch was a basic 2310-kJ meal containing 40 kJ fat substitute (Sub lunch). The 3 other lunches consisted of the same basic meal supplemented with either 1200 kJ long-chain triacylglycerols (LCT lunch), 1200 kJ MCTs (MCT lunch), or 900 kJ carbohydrate plus 300 kJ LCTs (Cho lunch). RESULTS: Energy expenditure was not significantly different after the different lunches, but carbohydrate oxidation was lower after the MCT and LCT lunches than after the Cho lunch. Fat oxidation was greater after the MCT and LCT lunches. The time of the dinner request was significantly delayed after the Cho lunch. Food intake at dinner was significantly lower after the MCT lunch than after the Sub and Cho lunches, but the dinner meal request was not delayed. CONCLUSION: Carbohydrate may have a greater role in the duration of satiety than does fat, but MCTs may play an active role in other aspects of the control of food intake, especially in satiation at the next meal.

Influence of medium-chain and long-chain triacylglycerols on the control of food intake in men.

Hunger may be delayed and food intake reduced under metabolic conditions that spare carbohydrate oxidation, especially during oxidation of medium-chain triacylglycerols (MCTs) or monounsaturated triacylglycerols. In 12 healthy, adult, male volunteers isolated and deprived of any time cues, we compared the effects of 4 high-carbohydrate breakfasts (1670 kJ) supplemented either with a fat substitute (Sub; 70 kJ) or with 1460 kJ fat as monounsaturated long-chain triacylglycerols (LCT-U), saturated long-chain triacylglycerols (LCT-S), or MCTs. In the first session we investigated the effects of these breakfasts on the following food intake variables: hunger ratings at repeated intervals, the time until the spontaneous request for the next 2 free-choice meals, and the amount of food consumed. In a second session with fixed lunches, we studied the effects of the same breakfasts on plasma glucose, insulin, triacylglycerol, fatty acid, and beta-hydroxybutyrate concentrations. The addition of any of the fats to the high-carbohydrate breakfasts did not alter hunger ratings, but significantly delayed the request for lunch compared with the low-fat breakfast. The free-choice lunch eaten after the MCT breakfast was also significantly smaller. Blood glucose and insulin concentrations were lower after the 3 fat breakfasts, followed by larger increases in glucose and enhanced insulin responses 30 min after the lunch. No differences were observed between the LCT-U and LCT-S conditions. We conclude that MCTs decreased food intake by a postabsorptive mechanism, although the exact effect of these lipids on carbohydrate oxidation will require further studies involving nutrient balance measurements.

An endocrine and metabolic definition of the intermeal interval in humans: evidence for a role of leptin on the prandial pattern through fatty acid disposal.

BACKGROUND: It has been proposed that leptin provides a hormonal link between adipose stores and food intake. OBJECTIVE: This study investigated the role of leptin in the prandial pattern. DESIGN: In experiment 1, a spontaneous prandial pattern was recreated in 6 young, normal-weight men who were deprived of time cues and had blood withdrawn continuously at a frequency of one tube every 5 min. Meals were consumed ad libitum and dinner was requested voluntarily. Data from a second experiment, conducted in 8 subjects, were used to confirm the changes in leptin during the intermeal interval (IMI). RESULTS: Plasma leptin gradually rose to a peak (62 +/- 18% of the lunch concentration) during the IMI and declined before the dinner request (-21 +/- 4% of the peak concentration). This preprandial decline was confirmed in experiment 2 (-15 +/- 9%). The leptin concentration at lunch and fat-free mass were the only significant predictors of the IMI (both: r(2) = 0.91, P = 0.03). With fat intake at lunch, the leptin concentration at lunch was a positive predictor of the area under the curve of plasma fatty acids during the IMI (r(2) = 0.95, P = 0.01). Moreover, the leptin concentration at lunch was negatively correlated with energy intake in the first course of this meal (r = -0.95, P < 0.005). A similar result was found at dinner (r = -0.85, P < 0.05). Last, the change in leptin was predicted accurately by changes in glucose, triacylglycerol, and fatty acids (r(2) = 0.87, P < 10(-5)). CONCLUSION: Plasma leptin concentrations increase during a spontaneous IMI and decline before the onset of a meal. The results argue for a role of leptin in the prandial pattern through fatty acid peripheral disposal.

Satiety power of dietary fat: a new appraisal.

Accumulating evidence suggest that a good way to compare the satiety power of meals with different compositions or energy contents is to measure the onset latency of the next meal when freely requested by subjects deprived of any time cues. This study was performed in normal-weight young men (aged 19-24 y) isolated from time cues. At sessions 1 and 2, we studied the effects of two high-carbohydrate pasta lunchs with either 50 g low-energy butter substitute (lunch A) or 50 g butter (lunch B) on hunger ratings, on the latency of the dinner request, and on energy and nutrient intakes at the offered ad libitum dinner. Sessions 3 and 4 were designed to examine the effects of the two lunchs on the postlunch and predinner profiles of plasma glucose, insulin, glucagon, and lipids; consequences on the metabolic and hormonal responses to the fixed dinner offered on request also were tested. The addition of 1588 kJ butter to the pasta lunch compared with the addition of 67 kJ butter substitute had no effect on hunger ratings but significantly delayed the onset of dinner by approximately 38 min; however, neither energy intake nor nutrient intakes were different. The high-fat lunch led to a slightly different postlunch plasma glucose concentration profile but, as expected, to higher plasma triacylglycerol and fatty acid concentrations. The high-fat lunch also led to postdinner glucose intolerance with normal insulin and high fatty acid concentrations that may help explain the partial and delayed adjustment in energy intake after a high-fat meal as reported by some studies.

Comparing the effects of aspartame and sucrose on motivational ratings, taste preferences, and energy intakes in humans.

This study compared the effects of four breakfast preloads on motivational ratings, taste preferences, and energy intakes of 24 normal-weight nondieting young men and women. The preloads, composed of creamy white cheese (fromage blanc), were either plain or sweetened with aspartame or sucrose. Their energy value was either 1255 or 2929 kJ (300 or 700 kcal). Taste preferences were measured before and 150 min after breakfast. Motivational ratings were obtained at 30-min intervals. The subjects ate lunch, snack, and dinner meals in the laboratory. The consumption of low-energy as opposed to high-energy breakfasts, regardless of sweetness, led to elevated motivational ratings and increased energy intakes at lunch. However, intakes at subsequent meals were the same for all preloads, and no overall compensation in energy was observed. Aspartame did not promote hunger or lead to increased energy intakes in normal-weight subjects.

Effects of acute exercise on food intake and plasma free fatty acid levels.

The effects of acute exercise (swimming) on food intake (FI) and plasma free fatty acids (PFFA) were examined in male adult rats. FI decreased during the first hour after swimming; it was unchanged during the second hour; it decreased again during the third hour. Body weight decreased over the 24 hours following exercise (-1.7 +/- 1 g) while the animals gained weight during no exercise periods (+3.2 +/- 1 g). At the end of exercise, plasma glucose augmented as well as PFFA levels. An increase in sympathoadrenal activity per se and its inhibitory effect on insulin release can both be responsible for fatty acid mobilization from adipose tissue. Lipolysis could be a cause of hypophagia.

Chronic intracerebral cannula can affect feeding behavior in the rat.

Intracerebral cannulae were placed in the lateral ventricle of rats. It was shown that the cannulae per se can affect feeding behavior. After recovery from surgery, rats displayed an unusual eating rate which consisted of very long, slow and large meals. This slow eating rate led to a modification of the circadian pattern; it induced a decrease in night-time and increase in day-time cumulative intakes. This phenomenon appeared when cannulae crossed the cortical motor area concerned with forelimb movements. Different stereotaxic coordinates had to be used in order to place cannulae in the lateral ventricle without disturbing the feeding pattern. This observation underlines the importance of recording feeding pattern before any surgery in any study of feeding behavior.

Sensory versus dietary factors in cafeteria-induced overweight.

Normal Wistar rats became hyperphagic and obese when presented with high-fat, high-sugar or "cafeteria" diets. This phenomenon could be due to the very palatability of the offered foods but a metabolic factor could be suspected. In an attempt to distinguish the effects of the nutritional characteristics from those of the sensory properties of food, a new cafeteria diet, the "isocafeteria" diet, was developed. It consists of a choice of foods of similar, well-balanced composition but varying in taste, smell and texture. It was confirmed that in normal Wistar rats, the high-fat and the traditional "cafeteria" diet led to extra-weight gain. It was demonstrated that the daily presentation of a new choice of the palatable foods which composed the "isocafeteria diet" led also to a sustained increase in food intake and to overweight. Variety and high palatability are per se sufficient factors to overcome regulatory mechanisms. It was shown that the metabolic efficiency of such a regimen was strikingly higher than those of high-fat and traditional cafeteria diets.

Impact of sex and age on sensory evaluation of sugar and fat in dairy products.

Ratings of sugar/fat mixtures were examined in eight groups (2 sexes x 4 age categories) of healthy, normal-weight subjects (N = 226). The subjects were tested immediately before and after a standard lunch. Stimuli were 20 semisolid mixtures of soft white cheese or heavy cream containing between 0 and 30 grams of fat per 100 g, and sweetened with 1, 5, 10, 20 or 40% sucrose (wt./wt.). The subjects briefly tasted the samples; they rated stimulus sweetness, fat content and pleasantness, using 9-point scales. Sweetness ratings were a direct function of sucrose concentration. Rating of fat content was more accurate in older subjects. While palatability was nearly synonymous with sugar content in young boys, most groups showed inverted U-shaped preference functions, with optimal sucrose level at 10% in females and 20% in males. Stimuli were rated very slightly but significantly fatter and sweeter after than before lunch; taste preference ratings in the fed condition were sometimes reduced.

A method for long-term and accurate measurement and recording of the blood glucose level in man.

We describe a technique of continuous and long-term withdrawal of venous blood which permits a continuous measurement and recording of the blood glucose level. The preparation and setting up of a special double lumen catheter are detailed. This technique provides very accurate blood glucose time course determination and requires the withdrawal of small amounts of blood.

Exercise training modifies nutrient self-selection in rats.

Few studies have examined the effects of exercise training on macronutrient self-selection in rats. It has been observed that trained rats decreased carbohydrate and increased fat and protein intakes. In the present experiment, total energy intake and macronutrient self-selection were examined in adult male rats placed on a self-selection regimen and submitted to 2 h of treadmill exercise daily for 20 days at the beginning of the nocturnal period. Two control groups of rats were examined during the same time: a sedentary group that was food and water deprived during the same 2 h while trained rats were exercising, and a control group that was examined only for body weight gain and 24-h food intake. Food intakes of sedentary and trained rats were continuously recorded. At the end of the experiment, body weight of trained rats was lower than that of sedentary and control rats. The 24-h cumulative intake of trained rats was significantly reduced; this reduction was due to a decrease in fat intake, whereas carbohydrate intake was increased. In sedentary rats, 24-h intake was not modified but fat intake was significantly increased from the beginning to the end of the experiment. During the first 6 h of the night, protein and fat intakes of trained rats were reduced, and carbohydrate ingestion remained the same. Daytime food intake represented only 8.7% of the 24-h intake. Exercise training significantly increased this intake. It is noteworthy that during the middle part of the day (3-9 h) trained rats significantly enhanced protein and carbohydrate ingestion.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of interscapular brown adipose tissue denervation on body weight and feed efficiency in alcohol drinking rats.

In rats, chronic alcohol intake increases energy expenditure and enhances interscapular brown adipose tissue (IBAT) mass and activity. It is known that alcohol intake is mainly preprandial. In man, alcohol intake during a meal increases postprandial thermogenesis. Since diet-induced thermogenesis is mediated by the sympathetic nervous system, the effect of IBAT surgical denervation was examined on body weight (BW), food intake (FI) and feed efficiency (FE) in alcohol drinking rats. Alcohol drinking rats gained significantly less BW than water drinking rats; FI was identical and so FE was less in alcohol-treated animals. After sympathectomy, the water drinking group was identical to its own control group for BW gain, FI and FE. BW gain of sympathectomized drinking rats was significantly higher than that of controls. FI and FE were nearly identical. It is concluded that the increase in thermogenesis observed in chronic alcohol-treated rats is partly suppressed by sympathectomy. This increase could also involve other BAT mass and other tissues in the whole rat.