PubMed Health⌕ Search

Biomedical subjects

M Bouchard

Publications and source records attributed to M Bouchard.

At least 19 recordsLinked to original sources
PubMed1993

Solvent history dependence of gramicidin-lipid interactions: a Raman and infrared spectroscopic study.

We have investigated the interactions between gramicidin and a model membrane composed of one phospholipid, dimyristoylphosphatidylcholine, as a function of the cosolubilization solvent and incubation time used in the sample preparation. Three organic solvents have been used; trifluoroethanol, a mixture of methanol/chloroform (1:1 v/v), and ethanol. Using Fourier transform infrared spectroscopy, we have demonstrated that the conformation adopted by gramicidin in the membrane is dependent upon the cosolubilization solvent used, and, only with trifluoroethanol, it is possible to incorporate gramicidin entirely as a beta 6.3-helix. Moreover, Raman spectroscopy results indicate that the orientation of the tryptophan side chains in gramicidin and their interaction with the hydrocarbon chains and the carbonyl groups of the lipids are also dependent on the cosolubilization solvent. On the other hand, the effect of the incorporation of gramicidin on the thermotropism of the lipid bilayer was found to be dependent upon the conformation of gramicidin in the lipid bilayers.

Dimyristoylphosphatidylcholine↗
PubMed1989

The persistent Müllerian duct syndrome: a molecular approach.

A rare form of male pseudohermaphroditism is characterized by the persistence of Müllerian derivatives in phenotypic males. To determine the etiology of this syndrome, we studied the expression of anti-Müllerian hormone (AMH) in six boys, including three brothers, with the persistent Müllerian duct syndrome. All except one presented with an inguinal hernia containing the Müllerian derivatives, and in two boys the hernial sac contained the contralateral testis. AMH was normally expressed in the testicular tissue of two patients, as shown by bioassay of anti-Müllerian activity and immunocytochemistry. The testicular tissue of the other patients had no detectable bioactive or immunoreactive AMH, yet they expressed AMH mRNA with a normal transcription initiation site and in the amount expected for their age. These results prove the heterogeneity of the persistent Müllerian duct syndrome and suggest that it may sometimes involve peripheral insensitivity to AMH.

Animals↗
PubMed1989

[Familial congenital adrenal hyperplasia caused by 11 beta-hydroxylase. Failure of prevention of sexual ambiguity and prenatal diagnosis].

In a sepharad family from Morocco, 2 children out of 4 had congenital adrenal hyperplasia with 11 beta-hydroxylase deficiency. The index case had a very severe genital masculinization (Prader V), diagnosed at 18 months of age. For the fourth pregnancy, dexamethasone was given from the 8th to the 24th week of amenorrhea, in order to prevent the virilization of a female fetus. The treatment was interrupted for 5 days, at the 20th week, because of amniocentesis. As the amniotic steroid concentrations were normal, the treatment was stopped. Nevertheless the neonate also has severe virilization of the external genitalia and postnatal hormonal studies confirmed the diagnosis of congenital adrenal hyperplasia due to 11 beta-hydroxylase deficiency. The reasons for the failure of the treatment are analyzed.

Adrenal Hyperplasia, Congenital↗
PubMed1987

Comparative efficacies of erythromycin-sulfisoxazole and cefaclor in acute otitis media: a double blind randomized trial.

A prospective double blind trial compared the fixed combination of erythromycin-sulfisoxazole (E/S) with cefaclor in the treatment of acute otitis media. One hundred nineteen children in six centers across Canada were studied. Diagnostic tympanocentesis of 134 ears yielded 135 bacterial isolates: Streptococcus pneumoniae (42%); Haemophilus influenzae (21%); Branhamella catarrhalis (10%); Streptococcus pyogenes (5%); and other bacteria (22%). Seventy-seven percent of strains of B. catarrhalis and 14% of strains of H. influenzae were beta-lactamase producers. E/S exhibited greater in vitro activity against H. influenzae and B. catarrhalis. Twenty-three patients had bacteriologically sterile middle ear fluid. The overall clinical outcome at Days 10 and 31 was identical in both treatment groups. Otoscopic findings improved more rapidly in the E/S group than in the cefaclor group at 10 and 31 days (P less than or equal to 0.04). In cases where pre-treatment middle ear fluid was negative on routine bacterial culture, complete cure at 10 days was observed in 75% of patients treated with E/S but only in 14% of those treated with cefaclor (P = 0.02). Side effects were infrequent and comparable between the test drugs. E/S is at least as effective as cefaclor in the management of acute otitis media and may be superior, particularly for cases not yielding bacteria on routine culture.

Acute Disease↗
PubMed1986

Facial expressions of emotions and ethological behavioral categories.

The purpose of this study was to measure the capacity of human subjects to match facial expressions of emotions and behavioral categories that represented the motivational states they are supposed to illustrate. 100 university students were shown facial stimuli they had to classify using ethological behavioral categories. The results showed that accuracy of judgment was over-all lower than what was usually found when fundamental emotional categories were used. The data also indicated that the relation between emotional expressions and behavioral tendencies was more complex than expected.

Adult↗
PubMed1986

[Severe hypertrophic cardiomyopathy associated with an adrenocortical adenoma].

A case of severe asymmetrical hypertrophic cardiomyopathy occurring in a 11 month-old infant presenting with adrenocortical adenoma is reported. Cardiac involvement, as shown by echocardiography, recovered after complete excision of the tumor. Despite few published cases, the etiology of the associated cardiomyopathy is discussed.

Adenoma↗
PubMed1977

[Increased hematological toxicity of antineoplastic drugs with simultaneous androgenotherapy (author's transl)].

Thirty two patients with malignant lymphoma - mainly Hodgkin's disease - were randomized for simultaneous treatment by high doses of metenolone during MOPP chemotherapy, to reduce its hematological toxicity. The results have shown surprisingly an increased hemato-toxicity in patients receiving androgens, with significantly more marked anemia and thrombocytopenia, reducing the total doses of anti-cancer drugs. This side effect could be explained by a cycling of the hematopoietic stem-cells and call to some caution when androgens are used during cancer chemotherapy.

Androgens↗
PubMed1976

Cell volume measurements in acute leukaemia: method and value for diagnosis and prognosis.

Cell volume was measured using a Coulter counter in 42 cases of adult acute leukaemia, before any therapy. In every patient, the distribution was log-normal. A breakdown of the results with regard to the cell-type gives the following informations: The mean modal volume (M.M.V.) differs significantly from one type of leukaemia to another: the cell size in the myeloblastic type is larger than in the lymphoblastic, and smaller than in the monoblastic and myelomonocytic types. The dispersion of cell volumes, for a single patient, is low in acute lymphoblastic leukaemia, wider in myeloblastic cases and is even larger in myelo-monocytic patients. In 9 of the 10 acute myelo-monocytic leukaemias studied, the existence of two populations was shown by a double peak. Once relapse occurs, the cell volumes seem greater than during the first phase of the disease, at least in acute lymphoblastic leukaemia. No correlation has been found between the mean modal volumes and the labeling index, after incorporation of 3H-TdR.

Adolescent↗
PubMed1976

Sleep analysis during drug-free weekends in chronic schizophrenic patients.

The authors made a polygraphic registration of the night sleep in a sample of 14 chronic schizophrenic patients who for several months (mean 8 months) have been on a stable, relatively low maintenance dosage of neuroleptics administered according to the drug-free weekend schedule (two consecutive drug-free days at the weekend). During this treatment none of them showed a relapse or deterioration (BPRS, CGI, and NOSIE rating scales were applied periodically). Their only complaint was of sleep deterioration during the drugfree weekend nights, especially during the second night. The polygraphic night-sleep pattern of each patient was studied during two consecutive weeks. No difference was found between the adaptation night on medication and the consecutive night on medication during the first week, and between the adaptation and readaptation nights on medication during two consecutive weeks. There was no difference in any sleep parameters between the nights on medication and the first drug-free nights. There was a signifcant difference in the total sleep time between the nights on medications and the second drug-free nights. No difference was found in any other sleep parameters in nights analysed as a blocks and in the distribution of NREM and REM stages in the first vs. the second half of the night when B3 was compared with A2. The practical implication is, that to avoid any change in nocturnal behavior it is preferable to withdraw the medication on two nonconsecutive days in the week. The evaluation of both daily and nocturnal behavior seems to be a useful tool in evaluating the first sign of the drug-withdrawal syndrome.

Adult↗
PubMed1975

[In vitro study of sensitivity of leukemic cells to cytotoxic drugs (anticytogram)].

The in vitro sensitivity of leukemic cells to cytotoxic drugs was assessed in 61 cases of acute leukemia in adults, 49 of them were of the no lymphoblastic type and in the first phase of the disease. The depression of the incorporation of 14-C-thymidine and 3-H-uridine after a two hours incubation with the various cytotoxic drugs was compared with the clinical result obtained with two of them There is a significant correlation between the in vitro depression of the incorporation of 14-C-thymidine and the clinical effect of the drugs. This method, which may be utilized also in solid tumors, allows to predict with some accuracy the effect of chemotherapy, and to select between the various cytotoxic drugs. However the failure of a chemotherapy is generally related to an in vitro insensitivity of the malignant cells to almost all drugs.

Acute Disease↗
PubMed1975

Prediction of the response to chemotherapy in acute leukemia.

The prognostic value of the in vitro incorporation of labeled thymidine was evaluated in 53 cases of acute leukemia, by means of autoradiography and liquid scintillation (LS) count. A higher rate of incorporation before therapy with higher labeling index and LS- specific activity was observed in patients who later responded to chemotherapy with a complete remission. The in vitro depression of labeled thymidine incorporation after incubation with the two drugs selected for the induction therapy was more marked in those who responded to therapy than in the nonresponders. The in vitro incorporation of 3H-thymidine was also evaluated after 48 hours of chemotherapy ("vivo-vitro" test). A decrease of the incorporation was observed frequently in the responders. On the other hand, in the group of nonresponders, there was generally an increase of the incorporation measured by the liquid scintillation count, often contrasting with a decrease of the labeling index, and corresponding to a higher rate of intracellular incorporation. The prognostic value of these findings appears to be significant, as it allows the response to chemotherapy to be predicted, as well as allowing the selection of the various cytotoxic drugs.

Acute Disease↗
PubMed1975

Polygraphic night sleep pattern during chronic single and multiple neuroleptic dose administration.

A comparison was made between the polygraphic night-sleep pattern of chronic schizophrenic patients who were receiving a single dose of neuroleptics at bedtime and between the night-sleep pattern of the same patients receiving the same amount of the same neuroleptic divided into 3-4 doses during daytime. It was shown that the single bedtime dose provoked a significant increase in the mean percentage of the NREM stage 4 and of the mean percentage of the REM state whereas the mean percentage of the NREM stage 2 was significantly decreased.

Adult↗
PubMed1974

Release phenomena and iterative activities in psychiatric geriatric patients.

This survey was undertaken to assess the frequency of some of the so-called release phenomena and iterative activities in an aged psychiatric population. Three groups of geriatric psychiatric patients with diagnoses of (I) organic brain syndrome, including senile dementia (56), (II) functional psychoses, predominantly schizophrenia (51) and (III) chronic schizophrenia never treated by neuroleptics or other biologic agents (16), were compared with (IV) a control group of 32 elderly people in good physical and mental health.In general, for the manifestations studied, the geriatric psychiatric patients suffering from an organic brain syndrome and treated with neuroleptics differed notably from the control group. This latter group, although older, had few neurological signs of senescence and the spontaneous oral movements usually associated with the use of neuroleptics were absent. Release phenomena such as the grasp and pouting reflexes, as well as the stereotyped activities, were encountered significantly more frequently in patients with an organic brain syndrome than in the two other groups of patients. Our survey has yielded limited results with regard to the possible influence of type of illness and neuroleptic treatment on the incidence of release phenomena and iterative activities.

Aged↗