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Biomedical subjects

F Lenoir

Publications and source records attributed to F Lenoir.

10 recordsLinked to original sources
PubMed1998

Use of a pulse oximeter in an adult emergency department: impact on the number of arterial blood gas analyses ordered.

STUDY OBJECTIVES: To assess the impact of pulse oximetry (SpO2) on the indications and the number of arterial blood gas (ABG) levels ordered in an adult emergency department (ED). DESIGN: A prospective study during a 2-month period in 1993 with a pulse oximeter available and a comparison with the same period in 1992 without the oximeter. SETTING: An adult medical ED of a university hospital in France. PATIENTS: All patients who underwent ABG or SpO2 measurements. INTERVENTIONS: During the prospective study, residents ordered ABG or SpO2 measurements at their discretion. The reasons for their ordering were reviewed by two independent experts who determined whether their choice was justified. The data were compared with those for 184 consecutive patients who had ABG measurements in 1992. MEASUREMENTS AND RESULTS: The study included 152 patients. SpO2 alone was used in 33 patients; ABG levels were measured in 119 patients. The use of SpO2 did not result in the ordering of fewer useful ABG determinations. One hundred and five (88%) ABG measurements were justified. There were fewer unjustified ABG determinations in 1993 when the pulse oximeter was available than in 1992 when it was not (14 of 119 vs 54 of 184; p<0.001) mainly because fewer ABG determinations were ordered for miscellaneous nonrespiratory indications (13 of 119 vs 43 of 184; p<0.01). CONCLUSION: The availability of a pulse oximeter did not affect the ordering of useful ABG measurements but allowed a significant reduction of unjustified ABG measurements. Substantial cost savings could be achieved by using SpO2 in an ED.

Adult↗
PubMed1994

Organization of the endoplasmic reticulum in renal cell lines MDCK and LLC-PK1.

The spatial organization of the endoplasmic reticulum has been studied in two renal cell lines, MDCK and LLC-PK1, which originate from the distal and proximal portions of the mammalian nephron, respectively, and which form a polarized epithelium when they reach confluence in tissue culture. The two renal cell lines, grown to confluence on either solid or permeable supports, were investigated by fluorescence microscopy, confocal microscopy, and transmission electron microscopy. Fluorescence labeling of the endoplasmic reticulum was achieved using the cationic fluorescent dye DIOC6 (3). In order to differentiate fluorescent labeling of the endoplasmic reticulum from that of the mitochondria, cells were also labeled with rhodamine 123. For electron microscopy, the spatial organization of the endoplasmic reticulum was examined in thick sections using the long-duration osmium impregnation technique or the ferrocyanide/osmium technique. In both cell lines, the endoplasmic reticulum formed an abundant tubular network of canaliculi that frequently abutted the basolateral domain of the plasma membrane and occasionally the apical membrane. Elements of the endoplasmic reticulum were also found in close proximity to mitochondria that, as in the nephron, formed branched structures. Canaliculi appeared circular or flattened and had an inner diameter of 10-70 nm for MDCK cells and 20-90 nm for LLC-PK1 cells. Such a three-dimensional organization might facilitate the translocation of defined lipid species between the endoplasmic reticulum and the plasma membrane, and between the endoplasmic reticulum and mitochondria.

Animals↗
PubMed1991

Neuroendocrine factors affecting the glycogen metabolism of purified Mytilus edulis glycogen cells: partial characterization of the putative glycogen mobilization hormone--demonstration of a factor that stimulates glycogen synthesis.

A putative glycogen mobilizing hormone (GMH) from the marine mussel Mytilus edulis L. has been partially characterized. GMH activity is present in the cerebral ganglia and the hemolymph serum and promotes the mobilization of glycogen in isolated glycogen cells. The cerebral GMH is trypsin sensitive and partially heat labile and has an apparent molecular mass of greater than 20 kDa. Following fractionation of cerebral extracts by molecular mass, a second factor, with a molecular mass of ca. 1.5 kDa, was discovered. This factor stimulates post-incubation incorporation of 14C into glycogen in isolated glycogen cells.

Animals↗
PubMed1990

A putative neuroendocrine factor that stimulates glycogen mobilization in isolated glycogen cells from the marine mussel Mytilus edulis.

Glycogen synthesized by purified glycogen cells, from the labial palps of Mytilus edulis, was labeled by preincubation in culture medium containing D-[U-14C]glucose. It was stable for at least 4 hr of postincubation in the absence of 14C. Glycogen mobilization was provoked by an acid extract of the cerebral ganglia. The active factor was also found in the hemolymph. The glycogen cells exhibited a dose-dependent response to the cerebral extract. The active cerebral factor is methanol soluble and possesses hydrophobic properties. It is postulated that this factor is a neurohormone.

Animals↗
PubMed1988

A gonial mitosis-stimulating factor in cerebral ganglia and hemolymph of the marine mussel Mytilus edulis L.

A gonial mitosis-stimulating factor produced by the cerebral ganglia of the mussel Mytilus edulis has been demonstrated. This factor induces an increase of [3H]thymidine incorporation in the DNA of isolated mantle cells. Dose-response data are obtained with the methanol phase of an acidic ganglia extract. The rate of [3H]thymidine incorporation is compared with aspartate transcarbamylase specific activity, another bioassay previously described to estimate mitotic activity. This heat-stable mitogenic factor appears to have a molecular weight of less than 5000 Da. A gonial mitogenic factor is also found in the hemolymph and circulatory cells.

Animals↗
PubMed1986

[Blood pressure from 0 to 18 months. Use of an automatic measurement method].

A prospective study of blood pressure in 251 neonates and infants aged 0 to 18 months was undertaken with an automatic measurement method. Children of black race (n = 33) were taller (p less than 0.05), heavier (p less than 0.025) and older (p less than 0.001) than the rest of the sample, but had lower systolic (SAP) and diastolic arterial pressures (DAP), especially between 9 and 18 months (p less than 0.01). There was no significant difference according to race [North Africans (n = 50), white (n = 143) and the others (n = 25)], or to sex. For the sample (n = 218) of non black children, SAP and DAP increased with age (p less than 0.001), weight (p less than 0.001) and height (p less than 0.001). Percentiles were determined in each age class for SAP and DAP. Mean pressure figures increased from 86.8 mmHg (0-1 month) to 108 mmHg (9-12 months) for SAP and from 52.5 mmHg (0-1 month) to 65.5 mmHg (9-12 months) for DAP.

Age Factors↗
PubMed1982

Enzymatic determination of acetate in serum or plasma using a centrifugal fast analyser.

A simple enzymatic spectrophotometric micromethod is described for direct kinetic assay of acetate in serum or plasma using the Eni-Gemsaec centrifugal fast analyser. The method is based on the transformation of acetate and ATP into acetylphosphate and ADP by acetate kinase (EC 2.7.2.1). ADP is further measured by two coupling reactions involving pyruvate kinase (EC 2.7.1.40) and lactate dehydrogenase (EC 1.1.1.27) with measurement of NADH consumption at 340 nm. The method involves a reagent blank for compensation of reagent deterioration, a preincubation of 3 min without acetate kinase to eliminate any interference due to endogenous pyruvate, and a two-point kinetic protocol with measurements of absorbance at 95s and 395 s. The analytical performances of the proposed method were investigated using an evaluation scheme proposed by the French Society of Clinical Biology.

Acetate Kinase↗
PubMed1977

[Electrometric determination of urinary ammonia using a continuous-flow automatic method].

A critical study has been designed to evaluate the application of an electrometric method to the assay of ammonia in urine. The use of NH3-gaz permeable membrane electrode with a continuous flow system seems to have solved most of the problems evoked by former studies. The results obtained show that the method is reliable for the use in clinical routine. The simplification of the ammonia measurement procedure thus achieved will allow an important increase in the number of renal function tests that a clinical routine laboratory can handle in a hospital.

Ammonia↗