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Biomedical subjects

M Giroux

Publications and source records attributed to M Giroux.

At least 37 records · Page 2Linked to original sources
PubMed1994

Expression of ADP-glucose pyrophosphorylase in maize (Zea mays L.) grain and source leaf during grain filling.

The time course of ADP-glucose pyrophosphorylase activity and of starch accumulation rate measured in grain, from pollination to maturity, in Zea mays L. plants grown outdoors, was coincident for 2 years. No such correlation was observed in the adjacent leaf, which, furthermore, presented large year-to-year differences in starch accumulation pattern. Analysis of the expression of ADP-glucose synthase at the protein levels, using antibodies directed against the Bt2 or Sh2 subunits, established that the variation of activity in the grain was explained by parallel changes in the content of both subunits. The cDNA for Bt2 and Sh2 subunits were used as probes to quantify the corresponding messenger. In grain, the time course of Bt2 and Sh2 mRNA accumulation anticipated, with a similar pattern, the specific peptide variations, which suggests a transcriptional control of expression. By contrast, the control of leaf activity by protein content was less obvious than in the grain, and changes in leaf enzyme specific activity were suggested during the first 20 d after pollination. A clone homologous to the grain Bt2 subunit cDNA was isolated from a maize leaf cDNA library, and a sequence comparison showed that the leaf clone (L2) was a partial cDNA representing one-third of the mature peptide. A 97% homology was observed between Bt2 and L2 in their coding region, but homology was poor in the 3' noncoding border. This result demonstrates that Bt2 and L2 arise from different genes presenting a tissue-specific expression pattern and provides an explanation for the earlier reported differences between leaf and grain in the size of peptide and mRNA for the Bt2-homologous subunit.

Amino Acid Sequence↗
PubMed1994

Echocardiographic detection of intracardiac thrombi complicating ventriculo-atrial shunt. Report of two cases.

Right atrial thrombi are rare but serious complications of ventriculoatrial (VA) shunts. Two hydrocephalic patients who received a VA shunt developed thromboembolic complications. The initial manifestation was malfunction of the distal end of the shunt and right heart failure. Bidimensional echocardiography demonstrated an intracardiac mass on the distal intra-auricular end of the shunt. Pulmonary scan showed multiple emboli even in the asymptomatic patient. This demonstrates the important role of bidimensional echography as a noninvasive diagnostic technique for this particular complication of a VA shunt. Medical and surgical treatment modalities are discussed.

Aged↗
PubMed1993

Abducens palsy following shunting for hydrocephalus.

Over a period of 12 years, 80 patients underwent ventricular shunting for normal pressure hydrocephalus. Three developed sixth cranial nerve palsy in the first two weeks after surgery. This uncommon complication is usually transitory following the same pattern of abducens palsy after lumbar puncture or spinal anesthesia. Traction on the nerve with local ischemia has been involved as the responsible mechanism in both instances.

Abducens Nerve↗
PubMed1993

Experimental study of transplacental passage of alpha interferon by two assay techniques.

Two methods of assaying alpha interferon (IFN-alpha) were compared during an experiment aimed at determining whether IFN-alpha crosses the human placenta. Human placentas, collected after delivery following a normal pregnancy to term, were catheterized on both sides: fetal and maternal. The IFN-alpha was introduced in known amounts in the maternal circulation and was assayed in the efferent fetal fluid. The following two detection methods were used: radioimmunoassay by competition with [125I]IFN-alpha and assay with a biological system in which IFN-alpha protected Madin-Darby bovine kidney cells from destruction by vesicular stomatitis virus. The results obtained by the two methods were in perfect agreement for the efferent fetal fluid samples. They showed the absence of placental transfer of IFN-alpha. The biological method was found to be more sensitive than radioimmunoassay for low IFN-alpha titers (< 10 IU/ml) but was less reproducible, probably owing to the use of twofold dilutions. The specificities of the two methods were similar and their practicalities were equivalent; the biological method, however, was less costly. The study illustrates the complementarity of the two methods, which were based on different principles. The agreement obtained between the two methods provides a clear confirmation of the experimental results.

Adult↗
PubMed1992

Intraventricular central neurocytoma.

A case of central neurocytoma treated surgically is described. The authors review the literature. Emphasis is placed on radiological and pathological features not previously described. In particular, the intra-operative ultrasound appearance is described. The role of adjunctive radiotherapy is also discussed.

Adolescent↗
PubMed1991

Placental transfer of glycosaminoglycans in the human perfused placental cotyledon model.

Placental transfer of unfractionated heparin (UH), of low molecular weight heparin CY 216 (LMWH) and of Dermatan sulphate (DS) was studied using the human perfused placental cotyledon model. Two different techniques were used to assess the transfer: labelled molecules and biological activities as measured by antifactor Xa or antifactor IIa activities. No biological activity was present in the fetal circulation, for any of the drugs used; however, very low fractions of the perfused radioactivity were recorded, 0.76% +/- 0.36%, 1.46% +/- 1.44% and 2.37% +/- 0.89% for DS, UH and LMWH, respectively.

Dermatan Sulfate↗
PubMed1991

Maternal and umbilical cord concentrations of fentanyl after epidural analgesia for cesarean section.

The maternal and umbilical concentrations of fentanyl were measured after epidural analgesia for cesarean section, using a highly sensitive radioimmunoassay method. Sixteen parturients were anesthetized with a single epidural injection of a mixture of 85 mg bupivacaine 0.5%, 60 mg etidocaine 1%, and 100 micrograms fentanyl with epinephrine 1:200,000. Apparent maternal individual maximum peak concentration (Cmax) of fentanyl was 0.38 +/- 0.16 ng/ml (mean +/- SD) (range 0.12-0.59 ng/ml) and the time to reach Cmax (Tmax) was 24 +/- 14 min (range 5-60 min). Infants were born 19 to 42 min after epidural administration of fentanyl (mean 27 min). Fentanyl concentrations in neonates was 0.13 +/- 0.04 ng/ml for the umbilical vein and 0.06 +/- 0.03 ng/ml for the artery. The fetus extraction ratio was 53 +/- 19% (range 20-83%). The large difference between arterial and venous concentrations of fentanyl may be due to a metabolization by the fetus and/or an uptake of the drug in the fetal tissues. Thus, even if fentanyl levels reaching the fetus after cesarean section under epidural anesthesia, using local anesthetics with 100 micrograms of fentanyl, are within safe range values, the likelihood of fentanyl uptake by fetal tissues calls for a cautious use of repeated fentanyl administration.

Analgesia, Epidural↗
PubMed1990

[Epidural hematoma of the posterior cranial fossa].

The use of CT scans has entirely modified the prognosis of epidural hematomas of the posterior cranial fossa. The analysis of a personal series of 20 cases diagnosed and treated over a 10 year period, that is 6.5% of E.D.H. cases seen in this hospital, has enabled us: to propose an anatomical study regrouping the different topographic forms observed in the literature as well as in the present series. to check the deceptive radiological appearance of these hematomas. The main sign remains the existence of a cranial fracture at the level of the occipital bone. Repeated CT scans should attempt to localize this lesion. In 15% of our cases, the lesion was only detected on the second CT scan. to recommend a simple and rapid surgical procedure in the ventral decubitus position, which does not involve the foramen magnum approach. This is performed away from the occipital junction of the venous sinus. to underline the progressive decrease in the mortality rate (10%) and the good subsequent prognosis of these apparently serious forms which have left no sequelae.

Adolescent↗
PubMed1990

Effects of pH on antipyrine transfer across the human placenta ex vivo.

The influence of pH variations on transplacental transfer of antipyrine was studied using a human placental cotyledon perfused ex vivo. The antipyrine transfer rate is positively correlated with the pH in the fetal circulation and negatively correlated with the pH in the maternal circulation. Thus, the transfer rate is negatively correlated with the difference between pH values in maternal and fetal circulations. The antipyrine transfer rate is also positively correlated with the flows in maternal and fetal circulations. The above parameters allowed to explain 50% of the variance on the transfer rates obtained in various experimental conditions. In a final series of experiments where these parameters for each placenta were fixed at identical values, a good reproducibility in the results was obtained, the variation coefficient being 17%. Thus, establishing the effect of variations in pH allowed a good standardization of the perfused cotyledon model. This effect cannot be explained by modifications in the ionized fraction of the antipyrine molecular and is probably due to physiological mechanisms.

Adult↗
PubMed1990

[Respiratory symptoms in schoolchildren in Toulouse. Influence of atmospheric pollution].

In order to get a better knowledge on respiratory illnesses of children in Toulouse, and to evaluate the influence of air pollution, 1,000 children between 8 and 11 years of age, living in five different areas of the city were observed during one year (March 1985-March 1986), together with the measure of twenty pollutants. A questionnaire was used to assess the history of respiratory diseases and the chronic respiratory pathology. According to the areas, no difference appeared, other than the frequent cough which is more important in an area with lower social income (p less than 0.01). The acute respiratory illnesses, as noted during the year of observation, had a different pattern according to the areas (p less than 0.0001). Amongst the five pollutants used for the analytic study through the cross-correlations, four: nitrogen monoxide and dioxide, black fumes, and ammonia particulate derivatives are related to the respiratory diseases.

Acute Disease↗
PubMed1987

Transcutaneous carbon dioxide measurements in the fetus during labor.

Continuous transcutaneous carbon dioxide partial pressure (tcPco2) was monitored in 40 spontaneous labors. The electrode was attached by glue fixation. An interpretable tracing was obtained in 36 cases. All cases but 2 were normal pregnancies. Thirty-two patients had epidural analgesia while the others had no analgesia. All infants had an Apgar score above 7 at five minutes after delivery and only two had a pH of the umbilical artery of less than 7.16. Mean duration of the recordings was 116 minutes (range: 15-300) and mean time for reaching steady-state was 27 minutes (range: 10-45 minutes). Mean value of tcPco2 was 48 mmHg (SD: 6) before 6 cm of dilatation, 47 mmHg (SD: 8) between 6 and 10 cm, and 47 mmHg (SD: 15) at the second stage of labor. Mean umbilical artery Pco2 was 48 mmHg (SD: 14) and mean umbilical artery pH was 7.25 (SD: 0.06). The range of tcPco2 obtained in these normal cases was 20 to 62 mmHg. Comparison of the results with those of other authors and with previous studies of normal labor and epidural analgesia show a higher tcPco2 compared to scalp Pco2. In contrast to other studies in these series no correlation was found in the series between umbilical artery Pco2 and tcPco2 values. This lack of correlation could be explained either by the small number of cases in which both measurements were available (9 cases) and by the small range of variation or by some inaccuracy in the measurements.(ABSTRACT TRUNCATED AT 250 WORDS)

Blood Gas Monitoring, Transcutaneous↗
PubMed1984

Effect of suloctidil on platelet function in patients with shortened platelet survival time.

The effect of suloctidil (600 mg/day) on platelet survival time (PST) and plasma and urine betathromboglobulin (BTG) was studied in a double-blind, placebo-controlled six-week crossover trial in 13 patients with shortened PST (less than 110 hrs, exponential model). Mean PST after suloctidil (110.6 hrs) was significantly higher than in the placebo phase (94.5 hrs) (p = 0.04). Mean plasma BTG was significantly lower during the suloctidil phase (42.8 ng/ml) compared with the placebo phase (65.8 ng/ml) (p = 0.02), but there was no significant difference in urine BTG. These results suggest that suloctidil provides a platelet protective effect and therefore may be of benefit in reducing the frequency of platelet mediated thromboembolic events.

Blood Platelets↗
PubMed1978

Study of fluorescent treponemal antibody test on cerebrospinal fluid using monospecific anti-immunoglobulin conjugates IgG, IgM, and IgA.

The fluorescent treponemal antibody test for cerebrospinal fluid (FTA-CSF) using monospecific conjugates anti-IgG, IgM, and IgA was used to determine the presence of anti-treponemal antibodies in the spinal fluid of 335 patients with primary, secondary, and latent syphilis and symptomatic and asymptomatic neurosyphilis and of patients with certain neurological disorders. Of these, 230 (68·65%) patients had non-reactive results to this test. Of the remaining 105 patients, 78, 63, and 10 had reactive results with anti-IgG, IgM, and IgA conjugates respectively. Of the 129 cases of known syphilis, 11 were diagnosed as primary, 32 as secondary, and 50 as latent, and 36 patients had neurosyphilis. None of the specimens from the patients with primary syphilis gave reactive results to the test. Specimens from 21 (65·62%) of the 32 patients with secondary syphilis, 30 (60%) of the 50 patients with latent syphilis, and all (97·22%), except one, of the 36 patients with neurosyphilis gave reactive results to one at least of the IgG, IgM, or IgA FTA-CSF tests. Among the specimens from patients with secondary syphilis twice as many gave reactive results with anti-IgG conjugate than with anti-IgM conjugate. However, with specimens from patients with latent syphilis and neurosyphilis this ratio was diminished to 1·5:1. The Kolmer complement-fixation test, although superior in sensitivity and specificity to the Venereal Disease Research Laboratory (VDRL) test, in patients with secondary and latent syphilis and neurosyphilis, was greatly inferior to the FTA-CSF test. Data indicate that anti-treponemal antibodies can be detected in the spinal fluid even in patients with no neurological symptoms in cases of secondary syphilis and that the FTA-CSF test can be a valuable tool in the early detection of an immunological response to treponemal infection in the spinal fluid.

Cerebrospinal Fluid↗
PubMed1967

Study of the use of lincomycin aerosols in dogs.

This paper reports studies on different aspects of the administration of lincomycin by aerosol in dogs.The purpose of the study was to determine the depth of penetration of the drug into the lungs and its transfer into the blood, urine and tissues when administered as an aerosol.Special consideration was given to the possibility of side effects at the level of the bronchial mucosa, since this study was viewed as preliminary to the use of the antibiotic in humans.

Aerosols↗