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Biomedical subjects

F Lebas

Publications and source records attributed to F Lebas.

At least 19 recordsLinked to original sources
PubMed2006

[Apnea of prematurity: risk factors and ambulatory treatment with caffeine citrate].

INTRODUCTION: Apnea of prematurity develop during the first days of life and usually resolve by the time the infant reaches 36-37 weeks postmenstrual age. In a few cases, they persist beyond term, especially in infants delivered at the youngest gestational ages (24-28 GA), and require specific care. In our unit, those preterm babies are discharged home with caffeine citrate treatment. Discontinuing the treatment is performed in hospital when they achieve a postmenstrual age of at least 42 weeks. OBJECTIVE: To identify predictive factors of persistent apnea in preterm babies. MATERIAL AND METHODS: Retrospective study comparing a population of 41 preterm infants discharged with treatment to 123 preterm babies discharged without treatment to identify predictors of persistent apnea. RESULTS: Factors significantly associated were: birth weight<1500 g, initial hypotension, gastroesophageal reflux, need for continuous positive airway pressure and multiparity. At home, no infant died and no adverse effect was reported by parents. CONCLUSION: Persistent apnea can be responsible for prolonged hospitalization. Risk factors can be identified in some children. Discharging with treatment can be an alternative to their hospitalization.

Ambulatory Care↗
PubMed2006

[Caffeine citrate utilization for treatment of apnea in French neonatal units].

UNLABELLED: Caffeine citrate is commonly used for prophylaxis and treatment of apnea in preterm babies. OBJECTIVE: To evaluate the use of caffeine citrate in french neonatal units. MATERIALS AND METHODS: Postal survey in 100 neonatal units. RESULTS: Answers were obtained from 81 units. Sixty-three units use systematic prophylactic treatment and the threshold of gestationnal age (weeks gestation) for this systematic treatment is 32 weeks. Caffeine citrate is administered as a loading dose of 20 mg/kg followed by a maintenance dose of 5 mg/kg in 95% of the units. Discontinuing the treatment occurs between 33 and 35 weeks in 37% of the units and between 35 and 37 weeks in 53%. Two third of neonatologits describe recurrent apnea beyond 37 weeks, with the need to continue treatment. Fourteen units sometimes discharge babies at home with ambulatory caffeine citrate treatment and discontinue treatment by 42 to 46 weeks'gestation. A mean duration of 5 days without apnea is required before discharge. CONCLUSION: French teams respect "recommendations" concerning doses and duration without apnea before discharge. Indication of treatment, threshold for systematic treatment, duration of treatment and ambulatory treatment differ among teams.

Apnea↗
PubMed2004

[Analgesic effects of Emla cream and saccharose solution for subcutaneous injections in preterm newborns: a prospective study of 265 injections].

OBJECTIVE: To compare the analgesic effects of non nutritive pacifier sucking, oral administration of a 30% saccharose solution, local application of Emla and their association for subcutaneous injection of erythropoietin (EPO) in preterm infants. METHODS: Our study was a randomised, prospective study conducted over 5 months. Neonates with a gestational age below 33 weeks of gestation and older than 8 days of life were included if they were treated with EPO (three subcutaneous injections per week during 6 weeks). For each consecutive EPO injection, patients were randomised between four groups of intervention: non nutritive pacifier sucking (T), oral administration of 0.2-0.5 ml of a 30% saccharose solution with non nutritive pacifier sucking (S), local application of Emla with non nutritive pacifier sucking (E), and oral administration of 0.2-0.5 ml of a 30% saccharose solution with local application of Emla and with non nutritive pacifier sucking (S + E). Each child was its own control. Pain was assessed with the Newborn Acute Pain scale (DAN) and with the Neonatal Facial Coding System (NFCS). RESULTS: Thirty-three neonates were included, representing 265 injections. Distribution was: 41 in group T, 71 in group E, 86 in group S and 67 in group E + S. Mean DAN and NFCS scores were statistically different between groups T, E and S. Analgesic effect of saccharose (-1.05) was greater than Emla (-0.56). Used together, effects were adding up without potentialisation. CONCLUSION: This study shows that the association of non nutritive pacifier sucking with oral administration of saccharose and local application of Emla has a better analgesic effect than each of these three interventions alone for subcutaneous injection of EPO.

Administration, Cutaneous↗
PubMed2004

[Congenital toxoplasmosis: a new case of infection during pregnancy in an previously immunized and immunocompetent woman].

UNLABELLED: Congenital toxoplasmosis is a potentially serious infection which usually affects infants born to non immune women. CASE REPORT: Our case report focuses on a baby born to a normally immunocompetent woman previously immunized against toxoplasmosis. To our knowledge only three similar cases have been published until now. CONCLUSION: We conclude that in front of a patient neonatal congenital infection picture, toxoplasmosis cannot be excluded on the ground of maternal immunity status and must be quickly investigated, given the emergency of appropriate treatment.

Angola↗
PubMed2004

[Use of diazepam in the treatment of opioid neonatal abstinence syndrome].

INTRODUCTION: The fetal opiate exposure presents many risks for the newborn. One of the most important is the neonatal abstinence syndrome that associates neurological and digestive signs. In some cases the vital prognosis can be involved. The evaluation of the syndrome's severity is based on certificated scales. The mortality has been reduced by the improved management of these neonates. Diamorphine, phenobarbital, chlorpromazine and diazepam are the most currently used. However, there is no consensus on the treatment. The data concerning the treatment are controversial, especially for the use of diazepam. The aim of our study was to describe the effects of diazepam obtained in three different centers and to compare our results to those of the literature. POPULATION AND METHODS: Twenty-three neonates were included. They were all hospitalized for abstinence syndrome and treated by diazepam. The Finnegan scale was used to evaluate the symptom's severity and the effects of the diazepam. The principal evaluation criteria were the duration of treatment and hospitalization, the timing in recovery of birth weight and the percentage of birth weight loss. RESULTS: The average treatment duration was 7 days, the average hospitalization duration was 18 days, the birth weight was recovered at 10 days of life and the percentage of loss of birth weight was 6.5%. Diazepam treatment failed in only one case. No case of intense dehydration occurred. CONCLUSION: Due to the retrospective design of the study, the diazepam could not be compared to other drugs. Nevertheless, it argues against the "anti-diazepam" attitude. A controlled randomised prospective study is needed to evaluated the optimal therapeutic strategy.

Adult↗
PubMed2003

Effects of jump training on passive mechanical stress and stiffness in rabbit skeletal muscle: role of collagen.

AIMS: This study evaluated the effect of a 15-week jump training period on mechanical parameters and collagen concentration of different muscle types in rabbits, at 50, 90 and 140 days of age. METHODS: Trained (T) animals were made to jump over obstacles in order to get food and water. The height of the obstacle was increased according to the animal's age. Control (C) animals were sedentary. Mechanical parameters (force, stress, stiffness) and collagen concentration were measured in Extensor Digitorum Longus (EDL), Rectus Femoris (RF), Semimembranosus Proprius (SMP) and Psoas Major (PSOAS). RESULTS: Both EDL and RF collagen concentrations and passive mechanical parameters increased between 50 and 140 days of age (P<0.001), whereas SMP and PSOAS collagen concentrations decreased (P<0.001). Soluble collagen concentration decreased similarly with age in all muscles and groups. Exercise training at 140 days induced a significant increase in force (EDL 20.4% and RF 15.3%, 0.01<P<0.05), stress (EDL 26.8% and RF 22.6%, P<0.001), and stiffness (EDL 13.2% and RF 16%, 0.001<P<0.05) with a greater collagen concentration (EDL 16.1% and RF 19.1%, 0.001<P<0.05). Finally, stiffness and stress are well correlated with collagen concentration in EDL and RF muscles at 140 days (0.74<r<0.84, P<0.05). CONCLUSION: These results suggest that jump training can increase muscle capabilities of strength and stiffness in fast-twitch mixed muscles with pennate architecture (EDL, RF). This increase is essentially mediated by a rise in cross-linked collagen fraction, coupled with a relative decrease in soluble collagen. The collagen covalent cross-links improve resistance and stability in force transmission processes during stretching.

Aging↗
PubMed2000

Restricted feed intake during fattening reduces intramuscular lipid deposition without modifying muscle fiber characteristics in rabbits.

The present study was conducted to determine the effects of feed restriction during fattening on muscle fiber characteristics and intramuscular lipid traits. From 11 wk of age onward, rabbits were given free access to feed (control group), or received 70% of the control feed intake (restricted group). At the same weight at slaughter, restricted-fed rabbits were 3 wk older than controls (18 vs. 15 wk). The longissimus lumborum (LL, white loin), biceps femoris (BF, white thigh) and semimembranosus proprius (SMP, red thigh) muscles were then removed, and biochemical and histochemical assays were performed. In the three muscles, there was no effect of feed restriction on mean fiber size or percentage of the different fiber types. Restricted vs. control feeding resulted in a significant reduction (P<0.001) in total lipid content in all three muscles. This reduction was paralleled by a decline (P<0.001) in the activities of the malic enzyme and glucose-6 phosphate dehydrogenase (G6PDH), generating NADPH for the support of fatty acid synthesis. The diet-induced variations in lipid concentration and enzyme activities were larger (P<0.05) in the pure oxidative SMP muscle than in the predominantly fast-twitch glycolytic LL and BF muscles. Whatever feeding status, the ratio of malic enzyme to G6PDH activities was sharply lower (P<0.001) in SMP than in BF and LL muscles (averaging 1.5 vs. 9 and 15, respectively). These data indicate that nutritional status regulates intramuscular lipid deposition, without changing fiber-type composition. Further studies are necessary to determine the role of G6PDH in the lipogenic process of oxidative vs. glycolytic muscles.

Analysis of Variance↗
PubMed1995

[In vitro simulation of rabbit cecal fermentation in a semi- continuous flow fermentor. III. Effect of the quantity of dry matter introduced daily in the fermentor and reproducibility of the method].

In a preliminary experiment, 3 Rusitec-like fermentors of 1 L capacity were operated under identical conditions. The only difference was the quantity to treated substratum introduced daily into each fermentor: 15 g/d (M15); 40 g/d (M40); and 60 g/d (M60) on a dry matter basis. The fermentation substratum was a rabbit feed that had been digested with amylase and pepsin. The organic matter was lost over 48 h at a significantly higher rate in the M15 fermentor than in M40 and M60: 30.4%, 19.7% and 17.3%, respectively. The pH values observed in M40 and M60 (5.99 and 5.83) were similar to that observed in vivo under ad libitum feeding conditions. The pH was higher in M15 (6.7), as observed in vivo with restricted animals just before the daily meal. The volatile fatty acids (VFA) proportions for C2, C3 and C4 were similar to the in vivo proportion for the 3 fermentors. The daily total VFA production was the largest with M40 but was associated with a poor stability and an excess of minor VFAs. The introduction of 15 g/d was preferred by the authors because of organic matter disappearance rate, pH stability and VFA production. In a second experiment, 4 fermentors were used in the same way as the M15 one, in order to study the reproducibility of the method. Small but significant differences between fermentors were observed for all parameters in relation to a high fermentor stability from 1 day to the next.(ABSTRACT TRUNCATED AT 250 WORDS)

Amylases↗
PubMed1994

Influence of the nutritional deficit of foetal survival and growth and plasma metabolites in rabbit does.

Two experiments were conducted in order to determine the influence of nutritional deficit on foetal survival and growth in rabbits does. All females were mated within 12 h of parturition and all the young were removed at that time. In experiment 1, females were fed close to ad libitum (C1, n = 20), or restricted to 100% (M1, n = 20) or 75% (R1, n = 19) of the maintenance energy requirement. On d 28 of gestation, foetal mortality was similar in the 3 groups, whereas foetal weight and protein content of the litters were reduced in feed-restricted groups (P < 0.001). In experiment 2, females were fed ad libitum (C2, n = 12) or were restricted to the same level as in R1 (R2, n = 13). Blood samples were collected on d 17 and 28 of gestation before and after (1 and 3 h) a standardized meal. Pre- and postprandial concentrations of non-esterified fatty acids and urea were lower in the R2 than in the C2 females (P < 0.01). Preprandial concentrations of glucose were similar in both groups at d 17, and higher in the R2 groups than in the C2 group at d 28. The postprandial concentration of glucose was higher 1 h after the meal and lower 3 h after the meal in the R2 group (P < 0.01). Progesterone was significantly higher in the R2 females at d 17 (P < 0.001). These results suggest that nutrient deficit may be responsible for reduced foetal growth in concurrently pregnant and lactating does.

Animal Nutritional Physiological Phenomena↗
PubMed1993

Effects of lactation on fetal survival and development in rabbit does mated shortly after parturition.

Primiparous rabbit does were mated within 12 h after parturition (d 0). They were immediately weaned (Group W; n = 31) or allowed to suckle 10 young rabbits (Group L; n = 32). Blood samples were collected at d 0, 7, 17, and 28. Feed intake and live weight were measured weekly and pregnant does (Group W, n = 24; Group L = 25) were slaughtered at d 28. Feed intake was 78% higher in L than in W females throughout gestation (P < .001). However, L females lost weight during the second half of gestation (-243 +/- 25 g) compared with W females, which gained weight (246 +/- 20 g). The weights of carcass, skin, and adipose tissues were severely reduced at d 28 in the L group (P < .01). Ovulation rate (11.0 +/- .3 corpora lutea) and early embryonic mortality (< d 15) were similar in both groups (12.3 +/- 2%), whereas late embryonic mortality (> or = d 15) was higher in L than in W does (13.9 +/- 3 vs 3.9 +/- 1%; P < .01). Fetal weight was reduced by nearly 20% in L compared with W females (P < .01). Plasma concentrations of progesterone were lower in L than in W females at d 7 and 17 (P < .001), whereas concentrations of estradiol were similar in both groups throughout gestation. These results indicate that fetal survival and development can be impaired in lactating females.

Animals↗
PubMed1992

[In vitro simulation of rabbit cecal fermentation in a semi- continuous flow fermentor. II. Effect of inoculum type].

Two Rusitec fermentors were operated under identical conditions. One was seeded with an inoculum of rabbit caecal contents, and the other with bovine rumen contents. The fermentation substrate was rabbit feed that had been digested with amylase and pepsin. The substrate constituents (organic matter, OM and NDF) were lost in 48 h at a significantly higher rate in the presence of rumen inoculum (OM: +10%, NDF: +15%). The pHs of the 2 fermentors were similar at pH 6.6. The fermentors produced similar amounts of protein nitrogen per 24 h, after 6 d of adaptation. Volatile fatty acid production was slightly higher in the presence of rumen inoculum. The fermentor inoculated with rumen contents produced a higher percentage of propionic acid (25%) than of butyric acid (7%), while fermentation with rabbit caecal contents gave the opposite ratio (C3/C4 = 0.81). Consequently, only the rabbit caecal inoculum provided the fermentation profile characteristic of the species.

Amylases↗
PubMed1992

[In vitro simulation of rabbit cecal fermentation in a semi- continuous flow fermentor. I. Role of food substrate pretreatment].

A Rusitec semi-continuous flow fermentor was used to study the influence of enzyme pretreatment of food substrates on the fermentation profile over a 2-week period following inoculation with rabbit caecal contents. Three types of substrate were examined: 1) homogenized commercial rabbit feed; 2) the solid remains of this feed after digestion with alpha-amylase for 24 h; and 3) substrate 2 digested for 4 h with pepsin (double enzyme treatment). One of a pair of nylon pouches containing 15 g substrate was replaced each day, thus producing a uniform 48-h fermentation. Fermentation of the untreated feed (1) for 5-6 days produced a fermentation profile quite different from that obtained in vivo in the rabbit caecum: propionic acid accounted for over 35% of total volatile fatty acid (VFA), and butyric acid for about 15%. Amylase digestion (2) gave a stable ferment profile closer to the in vivo profile, except that propionic and butyric acids were similar at 15% of total VFA. Digestion with both amylase and pepsin (3) produced a stable fermentation profile very close to the in vivo profile: C2 > 60%, C3 < 11% and 17% < C4 < 21%. The rate at which membrane constituents (acid detergent fibre, ADF) were lost in 48 h was similar to the digestibility coefficient measured in vivo by others for the same basic feed. Lastly, there was a high percentage (about 5%) of volatile C5 fatty acids; this could be due to the discontinuous fermentor input of one pouch per 24 h. Thus, feed pretreated with both amylase and pepsin simulates, in vitro, rabbit caecal fermentation in a semi-continuous Rusitec type fermentor.

Animal Feed↗
PubMed1986

[Experimental study of diarrhea induced by a strain of Escherichia coli (serogroup O-103) in growing rabbits].

The experimental infection by mouth of weaned, 6 week old rabbits was performed with Escherichia coli strain O-103/10 without any adjuvant. The quantities of E. coli for the 3 experimental treatments were - none (control) - 10(4) or 10(7) per animal. The 142 rabbits were divided into 2 groups, each including the 3 treatments: A - observation of weight and eventual diarrhea during 25 days after infection; B - killing during the same period of some healthy and diarrheic animals every 2 or 3 days, for physiological, bacteriological, and histological observations. In the A group, mortality after 25 days was 0/24 in the control, 12 and 15/24 for 10(4) and 10(7) treatments respectively, but it was observed earlier for the 10(7) one. Diarrhea has been observed for 90% of infected and 20% of control rabbits, at first on day 7, 12 and 20 post-infection for the 10(7), 10(4) and control treatments respectively. The mean duration of diarrhea was 4 days in infected and only 2 in control rabbits. Always, diarrhea and weight lost were observed before death. Although the slowing down of growth rate during the experimental period, at the end, mean live weight was quite the same for animals surviving in the 3 treatments. Necropsy of killed rabbits of the B group, revealed hemorrhagic damages mainly on cecal and colonic wall, associated with high counts for E. coli (10(7) to 8 X 10(9] in the cecal content. In rabbits with highest counts (9/15), E. coli was also observed in blood. In diarrheic rabbits cecal pH was higher (6.61 vs 5.82) and cecal VFA concentration lower (53 vs 98 mM/l) than in healthy ones; but the proportions of acetic, propionic and butyric acids were not significantly affected. At constant VFA concentration in the cecum, pH and E. coli counts were correlated (r = + 0.35). Histology revealed first, attachment of bacteria to the apex of villi cells, and furthermore destruction of the epithelium with hemorrhages and necrosis. Thus the strain O-103/10 of E. coli is confirmed to be pathogenic and will provide a good experimental model for studies of diarrhea due to E. coli.

Animals↗
PubMed1982

[Establishment of puberty in the doe rabbit (folliculogenesis and ovulation. Effect of rationing the diet].

We used 307 Californian doe-rabbits divided into 7 experimental groups. The first 4 groups, fed an ad libitum diet, were presented to the male at 11, 14, 17 or 20 weeks of age. The other 3 groups were fed a 75 p. 100 ad libitum diet and were presented to the male at 14, 17 and 20 weeks of age. Three to 5 does per group were killed at 8 postcoitum hours to check the ovarian follicles, and the remaining females, after effective mating, were killed 12 days later to check the ovulation rate. Acceptation of mating was homogeneous (75-80 p. 100) in all the groups, except in the one with the restricted diet presented to the male at 14 weeks of age (55 p. 100). In ad libitum-fed does, the percentage of females mated and ovulating reached one-third at 14 weeks and two-thirds at 17 and 20 weeks. Rationing retarded by 3 weeks live-weight gain and ability to ovulate. Whatever the diet given, the mean weight of does of this breed had to reach 3 kg before the first ovulation occurred and 3.3 kg before the percentage of females ovulating after mating became normal. The number of ova found in ovulating females did not differ statistically in any of the groups, but the rationed does tended to have fewer ova (- 8 p. 100) in direct relation to their live weight. In fact, whatever the diet, the number of ova increased more than 2-units for a weight increase of 1 kg of live weight. In ad-libitum-fed does, the follicle population doubled between 11 and 14 weeks, then decreased to attain at 20 weeks the value found at 11 weeks. Although this population was unimodal at 11 weeks, it became bimodal afterwards and was clearly so at 17-20 weeks. The second mode represented 5 then 8 p. 100 of the total follicles which were large-size (greater than 407000 mu2) and corresponded to preovulatory follicles. The number of atretic follicles followed a similar pattern. Rationing did not change the follicular population of the first mode; on the contrary, it altered the size and number of the large-sized follicle population of the second mode. Rationing also increased the percentage of atretic preovulatory follicles in the two oldest groups.

Aging↗
PubMed1981

[Apparent digestability after ligature of the pancreatic duct in the growing rabbit: effect of ad libitum feeding].

We studied the apparent digestibility of an ad libitum diet in 16 growing rabbits, 8 with pancreatic duct ligature (P-) and 8 sham-operated (TO). The study was divided into two 10-day periods, starting 5 and 33 days, respectively, after surgery. The food intake of the sham-operated animals was higher (160 g/day at the end of the experiment) than that of the ligated ones (stabilized at 100-120 g/day); mean daily gain was also higher in the former (TO: 33.7 g/day, P-: 15.6 g/day; P less than 0.01). Dry matter (MS) and energy digestibilities were not significantly different in the P- and the TO groups, but nitrogen (N) digestibility, decreased after pancreatic duct ligature (TO: 86.1, P-: 64.9; P less than 0.01), then increased in time much more in P- than in sham-operated rabbits, but remained lower in the ligated group (-5.6 points). The results suggest that digestive compensation was established after pancreatic duct ligature; its origin is hypothesized.

Animals↗
PubMed1980

[Water and food ingestion in the young rabbit given food deficient in methionine or lysine and drinking by free choice a solution of that amino acid or pure water].

In a first trial, 21 five-week old rabbits housed in individual cages were divided into 3 experimental lots. All of them received the same lysine-deficient pelleted diet but lot 1 drank pure water only, lot 2 had a free choice between a solution of l-lysine (1.6 g/l) or pure water, and lot 3 drank l-lysine only. The trial lasted 24 days. The growth of lot 1 rabbits was significantly lower than that of lot 3 rabbits. The performance of lot 2 animals was intermediate but quite similar to that of lot 3. The lot 2 animals drank significantly more of the lysine solution than pure water (56 vs 44 p. 100). In a second trial, 60 five-week old rabbits housed 5 to a cage were divided into 4 lots. Lot 1 received a sulphur amino acid (AAS)-deficient diet + pure water, lot 2 a balanced diet + pure water, lot 3 the deficient diet + pure water and a solution of dl-methionine (1 g/l), and lot 4 the deficient diet + pure water + another dl-methionine solution (3 g/l). The trial lasted 19 days. Lot 2 showed improved growth due to the intake of the better AAS balanced diet. Lot 3 and 4 rabbits had intermediate growth which approached that of lot 2 animals as the methionine concentration in the solution increased. In both cases, the rabbits preferred the methionine solution to the pure water: 77 p. 100 in lot 3 (1 g/l) and 60 p. 100 in lot 4 (3 g/l). In conclusion, when the diet was deficient in AAS or in lysine and there was a free choice between either pure water or a solution of the deficient amino acid, the rabbits preferred the solution.

Animals↗