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Biomedical subjects

M Le Blanc

Publications and source records attributed to M Le Blanc.

At least 19 recordsLinked to original sources
PubMed2000

Two-dimensional polyacrylamide gel electrophoresis of the protease SP220K, a renal cell carcinoma marker.

The present study analyses, by two-dimensional polyacrylamide gel electrophoresis, the protease SP220K isolated from renal cell carcinoma. The pure molecule is separated using either immobilized pH gradient or isoelectric focusing in conventional carrier ampholyte in the first dimension. Some interactions with the acrylamide matrix in isoelectric focusing are discussed. The results demonstrate that two-dimensional gel electrophoresis performed with enriched media such as basolateral membranes, allows the detection of the protease. In addition, the non detection of the molecule up to now by this methodology can be explained by the high tendency of oligomerization of SP220K. Effectively the high molecular weight form of the molecule of 220 kDa is favoured in two-dimensional gel electrophoresis over monomeric forms which are better detected in SDS PAGE. This was confirmed by immunostaining performed with an antiserum to SP220K produced by nitrocellulose-bound antigen.

Biomarkers, Tumor↗
PubMed1993

Chemical and biological evidence links microcystins to salmon 'netpen liver disease'.

Evidence is presented that links microcystins to a severe liver disease that occurs in Atlantic salmon that are netpen-reared in coastal British Columbia. Liquid chromatography-linked protein phosphatase bioassay analysis of extracts of liver tissue taken from Atlantic salmon afflicted with netpen liver disease showed the presence of an inhibitor of protein phosphatase that was chromatographically indistinguishable from microcystin-LR. Analysis of liver tissue from healthy control fish showed a complete absence of microcystin-LR. Intraperitoneal injection of microcystin-LR into healthy Atlantic salmon re-created the pathologic changes of netpen liver disease, including diffuse necrosis and hepatic megalocytosis.

Animals↗
PubMed1992

Family dynamics, adolescent delinquency, and adult criminality.

Family and offending is probably the theme most researched in criminology. A comprehensive array of characteristics of family life have been linked to offending since the beginning of this century. This theme has been approached from two directions: a bivariable point of view, in which one characteristic of the family is related to a measure of offending, and a multivariate point of view, in which some family characteristics are used to explain offending. The literature is dominated by bivariable studies and although there are a few multivariate studies no specific theoretical perspective is proposed. In this paper we choose a control theory perspective and a comprehensive set of family variables to answer the following question: Can the explanation of offending be improved by a dynamic system family control theory? Additionally, the literature is principally focused on adolescent delinquency; in consequence we will study the following question: Are the family characteristics that explain most efficiently juvenile delinquency the same ones for the explanation of adult criminality?

Adolescent↗
PubMed1991

Social and psychological consequences, at 10 years old, of an earlier onset of self-reported delinquency.

In this paper we will answer the following question: what are the consequences of an earlier onset of delinquency on competence several years after onset? Rather than studying the social and psychological predictors of an early onset, we will be interested in the impact of the age of onset of self-reported delinquency on the social and personal adaptation of boys at age 10, social and personal adaptation referring to the broad concepts of competence--"having the requisite or adequate capacity or qualities to function or develop in a particular way" or "sufficiency of means for the necessities and conveniences of life."

Achievement↗
PubMed1991

Can disruptive boys be helped to become competent?

The Montréal Longitudinal Study of Disruptive Boys, an experimental study, was designed to understand boys who were considered disruptive in kindergarten. One part of the study involved assessing effects of a preventive treatment program carried out during the boys' early years in primary school. This paper reports on the outcome of the randomized treatment experiment 3 years after treatments ended. Disruptive boys were randomly allocated to a treated group and two nontreated groups. Treatment consisted of parent training and training of boys for social skills, fantasy play and television viewing. Results suggest that the treatment program had some positive effects. Some of the improvements were not evident immediately after treatment ended.

Achievement↗
PubMed1991

[Types of families, living conditions, functioning of family systems and social maladjustment during latency and adolescence in underprivileged milieus].

Available data on the impact of certain types of families is lacking, and the results are often misleading with respect to maladjustment. Following a description of variations in delinquent activity and behaviour problems according to family type, the authors analyse the difficulties in the operation of family systems. Comparisons of six family types apply to data from 763 boys aged 10, 319 female and 426 male adolescents, aged 14 and 15: intact families, father-based and mother-based single-parent families, father-based and mother-based reconstituted families and substitute families. The article's data show that in the late eighties, nearly 40 per cent of children and adolescents living in low-income districts in Montreal belonged to disunited families. In addition, the data confirm a classic observation: in comparison with intact families, disunited families are underprivileged in relation to living conditions, deficient in relation to psychosocial functioning, and propitious to behaviour problems and delinquent activity. In addition, it has been established that certain disunited family types represent a considerable risk factor. The damaging effect of family structure increases in the following order: intact families, mother-based single-parent families, mother-based reconstituted families, substitute families, father-based reconstituted families and father-based single-parent families. Finally, certain intervention methods are suggested to help prevent behaviour and family problems.

Adolescent↗
PubMed1989

New high O2 carrying perfluorochemical emulsions: toxicity, radiosensitivity of GM-CFC and development of metastases in mice.

The effects of two new concentrated perfluorochemical emulsions based on F-66E and PFOB, which carry significantly more oxygen than Fluosol-DA 20%, were tested on normal tissues (toxicity and radiation response) and on the development of metastases from Lewis Lung Carcinoma (3LL) in female C57 BL/6 mice. Twenty one days after injection of F-66E or PFOB emulsions (15 ml/kg body weight), the spleen and liver weights were significantly increased but had returned to normal after 2-3 months. Splenomegaly already observed in 3LL bearing mice was significantly increased by F-66E emulsion injection. The radiosensitivity of GM-CFC was not altered when unanesthetized GM-CFC was not altered when unanesthetized mice were pretreated with F-66E emulsions and/or carbogen 1 hr prior to and during irradiation. The rate of tumor take and the period before detection of tumors were not modified when an emulsion of F-66E was injected simultaneously or 10 days after 3LL cells. Mean survival of mice, and the number of metastases on lung surfaces were similar in F-66E injected mice and control mice.

Animals↗
PubMed1989

[Comparison of the behavior of full-term infant mothers and premature infant mothers during an interaction with their babies].

Studies on the first interactions have permitted the identification of both mother and the infant competences. But we have observed that in the case of a preterm birth, the infant's competences are in a large way transformed. In this situation, the mother has to adjust her own competences to the preterm infant's decreased response level. We studied 10 full term mother-infant and 10 preterm mother-infant dyads on videotapes and observed non-verbal and verbal behavioral differences between the two samples. We noted differing characteristics in postures, gaze, gesture, mimics, as well as in speech addressed to the infants. These observations have permitted a better comprehension of the way in which full term infant mothers interact with their babies, through anticipation on the corporal level as well as on the verbal level of the infant's activity. In contrast, the preterm infant mothers do not anticipate the infant's behavior, but rather stimulate him in a continuous way.

Child Behavior↗
PubMed1988

Design, synthesis and evaluation of fluorocarbons and surfactants for in vivo applications. New perfluoroalkylated polyhydroxylated surfactants.

The progress achieved since the advent of Fluosol-DA is summarized in this paper, with special focus on the synthesis and evaluation of more adequate, reliable, industrially feasible fluorocarbons, structure/property relationships--molecular weight being recognized as the pre-eminent determining factor of both the fluorocarbon's excretion rate and the emulsion's stability-, the preparation of significantly more concentrated, more efficacious emulsions, etc. The key to further progress and better mastery of the emulsions' characteristics, especially in relation to increased shelf-life, prolonged i.v. persistence, and versatility, now lies in the development of new surfactants, better adapted to this objective. New families of well defined, monodisperse perfluoroalkylated polyhydroxylated surfactants derived from sugars and related compounds have been synthesized and fully characterized. Preliminary evaluation of their surface-active properties, emulsion stabilizing capacity and biocompatibility are reported.

Biocompatible Materials↗
PubMed1988

[Family system and delinquant behavior in adolescence in Montréal in 1985.].

This article raises three questions : Has the family unit changed between the mid-70s and the mid-80s? Which characteristics of the family system are the most appropriate indicators of felonious activity? Does the explanation of felonious activity vary according to the sex of an adolescent? Two surveys conducted with Montreal adolescents in 1974 and in 1985 provide the answers. The authors show that the family structure has changed in view of single parenthood, its living conditions have deteriorated, control has been tightened, but emotional relationships have remained the same. The authors have found that the components of a family structure can be related to a precise model ; rebellion precedes delinquency ; didactic methods filter the influence of other family factors ; the psy-chosocial functionning of the family as well as conjugality follow as precipitative factors; finally, structural factors appear to have a remote influence. Also, the authors have noticed a great resemblance between boys and girls with respect to the primordial factors of delinquent behavior. In conclusion, the authors suggest practical involvement, particularly in terms of a diagnostic strategy for family problems, along with intervention strategies according to the type of problem.

English Abstract↗
PubMed1988

An integrative control theory of delinquent behavior: a validation 1976-1985.

Criminology should be a field of inquiry where psychology and sociology meet in seeking to explain delinquency, but this has rarely been the case. Our paper is an attempt in that direction within the context of a control theory. Ever since Lewin (1933) proposed his famous formula: B = (P) x (E), where conduct (B) depends on the interaction between the characteristics of a person (P) and his environment (E), there have been numerous attempts to encourage theoreticians to develop integrative theories of conduct--in other words, to take account of the sociological and psychological factors simultaneously.

Adaptation, Psychological↗