Search PubMed⌕ Search

Biomedical subjects

L Bernard

Publications and source records attributed to L Bernard.

At least 91 records · Page 5Linked to original sources
PubMed1992

Lack of effect of respiratory syncytial virus infection on theophylline disposition in children.

Conflicting reports raise a question about decreased plasma clearance (Clp) of theophylline in man during viral infections. Thus a dilemma exists concerning requisite dose adjustments. We examined this issue by retrospectively evaluating theophylline Clp in children infected with respiratory syncytial virus (RSV). Two pharmacokinetic approaches were applied to a one-compartment open model to fit theophylline concentrations during 83 hospitalizations of 76 children, 6 to 48 months of age, who received intravenous theophylline therapy and were tested for RSV infection. Iterative linear regression analyses of all theophylline data were used to estimate apparent volume of distribution, elimination rate constant, plasma half-life, and Clp in 39 of the hospitalizations. When insufficient data were available to distinguish apparent volume of distribution and elimination rate constant (n = 44), steady-state estimates of Clp were calculated. An age-matched and percentile body weight-matched cohort design presented RSV as the primary covariate. Theophylline Clp was similar in 29 matched RSV-infected and -uninfected pairs (1.32 +/- 0.14 and 1.25 +/- 0.05 ml/kg per minute, respectively), as were other pharmacokinetic values. Unexpectedly, a significant, inverse linear relationship was found for Clp and percentile body weight. Additionally, children born prematurely and hospitalized in the neonatal intensive care unit had significantly higher theophylline Clp; this did not affect findings regarding RSV infection. Theophylline Clp was not decreased in RSV-infected children. Current theophylline dosing recommendations for young children infected with RSV should not be altered, but careful monitoring of plasma theophylline levels should be continued.

Case-Control Studies↗
PubMed1991

Early scintigraphic detection of experimental myocardial infarction in dogs with technetium-99m-glucaric acid.

Recent data have generated some interest in technetium-99m-(99mTc) glucaric acid as an in vivo viability marker. We studied 99mTc-glucaric acid retention in canine models of myocardial ischemia (20-min occlusion of the LAD/40-min reperfusion), acute myocardial infarction (MI) (90-min LAD occlusion/3-hr reperfusion), and chronic MI (90-min occlusion and either 48-hr or 10-day reperfusion). Regional myocardial blood flow was measured by radiolabeled microspheres. No preferential uptake of glucaric acid was observed in ischemic but viable myocardium. The compound showed high affinity for necrotic myocardial tissue for several days following injury. The preferential uptake in infarcted tissue disappeared by 10 days following injury. This study shows that 99mTc-glucaric acid acts exclusively as a marker of necrosis in canine models of MI. Technetium-99m-glucaric acid may have clinical utility in early cardiac imaging of myocardial infarction and in differentiating recent from old injuries.

Animals↗
PubMed1990

Substratum effects on cell dispersal, morphology, and differentiation in cultures of avian neural crest cells.

Adhesive extracellular matrix (ECM) molecules appear to play roles in the migration of neural crest cells, and may also provide cues for differentiation of these cells into a variety of phenotypes. We are studying the influences of specific ECM components on crest differentiation at the levels of both individual cells and cell populations. We report here that the glycoproteins fibronectin and laminin differentially affect melanogenesis in cultures of avian neural crest-derived cells. Clusters of neural crest cells were allowed to form on explanted neural tubes for 24 and 48 hr, and then subcultured on uncoated glass coverslips or coverslips coated with fibronectin or laminin. The morphology of cells varied on the three substrata, as did patterns of cell dispersal. Crest cells dispersed most rapidly and extensively on fibronectin. In contrast, cells on laminin dispersed initially, but then assumed a stellate morphology and rapidly formed small aggregates. Cell dispersal was minimal on glass substrata, resulting in a uniformly dense distribution. These patterns of dispersal were similar in subcultures of both 24- and 48-hr clusters, although dispersal of cells from older clusters was less extensive. The rate and extent of melanogenesis correlated with patterns of cell dispersal. Cell from 24-hr clusters underwent melanogenesis significantly more slowly on fibronectin than on the other two substrata. Pigment cells began to differentiate by 2 days of subculture in the cell aggregates on laminin and in the dense centers of cultures on untreated glass. By 5 days, there was significantly more melanogenesis in cultures on laminin and glass than on fibronectin substrata. Melanogenesis in cultures of 48-hr clusters was more rapid and extensive on control (glass) substrata than on fibronectin or laminin, correlating with reduced cell dispersal. We conclude that fibronectin and laminin, which are found along neural crest migratory pathways in vivo, can affect melanogenesis in vitro by regulating patterns of cell dispersal.

Animals↗
PubMed1988

[Variations in the incidence of fractures of the upper part of the femur in aged persons in the Quebec region].

To estimate the incidence of fracture of the proximal end of the femur in people aged 50 years or older living in the Quebec area in 1971, 1976 and 1981 we determined the number of admissions for such fractures to the 15 acute care hospitals in the region. From 1971 to 1981 the number of fractures increased by 71%; the increases for those aged 75 to 84 years and 85 years or over were 98% and 118% respectively. The variation is only partly explained by changes in sex and age distribution of the population; the incidence rates also increased. Among men aged 75 to 84 years the incidence rate per 1000 person-years rose from 2.63 in 1971 to 5.22 in 1981, an increase of 98%; the corresponding figures for men aged 85 years or more were 9.76 and 16.91, an increase of 73%. Among women aged 75 to 84 years the rate rose from 7.28 to 8.81, an increase of 21%; the corresponding figures for women aged 85 years or more were 20.40 and 24.27, an increase of 21% and 19% respectively.

Age Factors↗
PubMed1988

[Differences in nitrogen and RNA contents between free bacteria and bacteria fixed to food particles in the rumen contents, in the case of different diets; consequences for estimating the ratio of bacterial nitrogen in duodenal nitrogen].

Differences in nitrogen and RNA contents were found between liquid-associated and solid-adherent bacteria isolated from the reticulo-rumen of ruminants offered various diets. Consequences on the estimation of the bacterial nitrogen flow to the duodenum are discussed.

Animal Feed↗
PubMed1986

[Absenteeism as a predictor of severe morbidity. A double case-control study (myocardial infarction and industrial accident) in a large company of the Quebec Province].

Are absenteeism indicators usefull as predictor of serious morbidity in a working population? To seek an answer was the objective of a double case-control study carried out in a large company (17000 workers) of Quebec Province. In the first study, 64 cases of myocardial infarction (incidence density = 1.66% +/- 0.35) were compared with 64 controls matched for sex, age and type of work. In the second one, 142 cases of labor accident were compared with 142 controls sampled in a similar way. Absenteeism frequency and length were analysed during the period of 6 to 12 years prior to the onset of the health problem. Ratios were calculated on an individual basis for all causes of absence and for sick leave; they were adjusted for length of service. A four classes interval scale was used for the comparison. An excess of absence length exists in the two studies. The excess is not significant for the myocardial infarction cases (+ 33%, with a statistical power = 51%). It is significant for the labor accident cases (+ 52%, p less than 0.01). The corresponding odds ratio calculated in reference to the lowest absence group were 2.4 (0.9-6.6) and 2.7 (1.5-4.9). The cumulative absence length can be considered as a predictor of serious disease. A conceptual framework of the relationship between absence and natural disease history is presented. The epidemiological approach to the phenomenon of absence is certainly usefull in spite of the controversy underlined by the social sciences.

Absenteeism↗
PubMed1981

[Curing trial of complicated oncologic pain by D-phenylalanine (author's transl)].

UNLABELLED: Aim of investigations: Very often, chronic pain treatments used for the management of terminal ill cancer patients do not prevent acute or incident pain from coming up. For twenty months D-phenylalanine (DPA), an enkephalinase inhibitor, has been investigated in order to forestall this pain. METHODS: Nine caucasian patients, three males and six females, between forty-nine and seventy-eight, were selected for this trial after informed consent. They were all undergoing severe incident pains related to complications (scabies, osteoporosis, painful cough or colic, Charley-Horse, RX-necrosis of skin or mucous membranes, etc) in spite of having their chronic pain component cured: phanol-rhizotomy: two cases, neuro-adrenolysis by alcohol: four cases, Brampton mixture: three cases. They were administered DPA, 250 mg three times a day for fifteen days, followed by a ten days pause, resumption and so on. RESULTS: Seven patients out of nine were alleviated and they never claimed for more or other analgesics until they died. Four of them got very good ataraxia during the same time (survival mean x = 99,33 days). No side effect was reported, even in patients taking Brampton mixture. CONCLUSIONS: DPA seems a useful drug to prevent acute or incident pain in malignant diseases. Our data point out the consequences the enkephalinases inhibitors will take up for the cure of intractable cancer pain.

Affect↗
PubMed1979

Spontaneous gastric rupture in the newborn.

Spontaneous rupture of the stomach during the neonatal period is the most common type of nonobstructive perforation. The clinical manifestations include severe abdominal distension, vomiting, and respiratory distress. However, diagnosis is based on an upright x-ray film of the abdomen which shows the "saddle" of "football" sign due to massive pneumoperitoneum. The fatality rate is still quite high. Success in treatment depends on early diagnosis and immediate surgical intervention.

Adult↗