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Biomedical subjects

C Rousseau

Publications and source records attributed to C Rousseau.

At least 37 records · Page 2Linked to original sources
PubMed2000

Scholastic achievement of adolescent refugees from Cambodia and Central America.

This study investigated the relationship of emotional disturbance and pre- and postmigration environment to the scholastic achievement of adolescent refugees of very different cultural backgrounds. One hundred fifty-two Central American and Cambodian students in six Canadian high schools, as well as their parents, were interviewed to assess the students' emotional problems (using the Youth Self-Report and Child Behavior Checklist) and to determine the pre- and postmigration family environment. The findings indicated that the relationship between the emotional problems and scholastic achievement of teenaged refugees was tenuous. It was concluded that a connection between young refugees' symptomatology and their functional capacity should not be assumed. Nonetheless, certain pre- and postmigration variables, particularly trauma experienced in the homeland, seem to be associated with the academic achievement of some refugees.

Achievement↗
PubMed1999

Family trauma and its association with emotional and behavioral problems and social adjustment in adolescent Cambodian refugees.

OBJECTIVE: The main aim of this study was to investigate the effect of war-related trauma on the subsequent social adjustment and functioning of young Cambodian refugees. METHOD: This longitudinal study of 67 young Cambodian refugees in Montreal interviewed in the first year of high school and then 2 years later examines a family's exposure to war related premigration trauma and its association with an adolescent's emotional and behavioral problems and social adjustment. Emotional and behavioral problems were assessed using the Youth Self-Report and an inventory of risk behavior. Social adjustment was assessed in terms of academic achievement, peer relations, and feeling of competence. RESULTS: The trauma a family suffered before leaving their homeland and prior to the teenager's birth seems to play a protective role at various times in adolescence with regard to externalized symptoms, risk behavior, and school failure in boys, and foster positive social adjustment in girls. CONCLUSIONS: These reactions may be understood as overcompensation by the children of the survivors of a massacre, to whom the implicit duty to succeed has been passed on. They suggest that a broader range of posttraumatic responses to war situations should be investigated and that trauma's dual nature as both burden and source of strength should be examined more closely.

Adolescent↗
PubMed1998

Polyalkylcyanoacrylate nanoparticles as carriers for granulocyte-colony stimulating factor (G-CSF).

The human recombinant granulocyte colony-stimulating factor (rhG-CSF) is largely used in the treatment of neutropenia occurring during chemotherapy. After injection, this glycoprotein distributes through the whole body. Thus, to obtain high and durable bone marrow concentrations, targeting with polyalkylcyanoacrylate nanoparticles was considered. Two methods of preparation were investigated: anionic polymerization and precipitation of the preformed polymer. By anionic polymerization, it was possible to associate more than 66% of rhG-CSF with nanoparticles (polyisobutyl- or polyisohexylcyanoacrylate nanoparticles) when the glycoprotein was added at the end of the polymerization process. It has been shown that the rhG-CSF was mainly adsorbed on the surface of the nanoparticles and most of the colony stimulating activity was conserved. Using precipitation of performed polyisohexylcyanoacrylate, 90% of rhG-CSF was associated with nanoparticles, the protein being mainly adsorbed onto the nanoparticle surface. In this case, a decrease of the colony stimulating activity was however observed. Whatever the method used, the in vitro release of rhG-CSF from the polyisohexylcyanoacrylate nanoparticles, was progressive during 8 h in seric conditions. Nevertheless, using mice as an animal model, it has been shown that the short-term effects of intravenously injected rhG-CSF were not increased by its association with polyisohexylcyanoacrylate nanoparticles.

Animals↗
PubMed1998

Between myth and madness: the premigration dream of leaving among young Somali refugees.

Many young Somali refugees experience long premigration waits and a poorly delimited transition period in a succession of countries before reaching their final destination. During this difficult passage, a myth dealing with departure and exodus is collectively constructed, and it serves as a dynamic, mobilizing dream that orients individual strategies. This substitution of "dream travel" for real travel during the transition period, especially if it is prolonged, may cause Somali youths to lose contact with reality and eventually to slide into madness. The authors' approach is based on three assumptions: (a) that pastoralism predisposes the Somali to value travel as a way of maturing, (b) that age-based peer groups create special migratory dynamics, and (c) that an ethic of solidarity involves many people in the adventure of a migrant youth. When trapped in an indefinite transition period, young men share khat-chewing sessions during which they relate success stories and dreams of leaving. Many grow frustrated with the delay, and if their departure plans fall through, the "dream trip" often becomes "dream madness." Actual cases illustrate how some young Somali get lost in their dreams. A young Somali's vulnerability is heightened when he extricates himself from the system of reciprocal obligations or when the liminal stage ends with the mourning of the impossible dream. In the universe of madness visited by some young Somali migrants, the boundaries between the real and the imaginary are poorly marked. The paper is based on fieldwork carried out in the Horn of Africa and in Canada, interviews with Somali immigrants and members of the community, and clinical psychiatric data collected in Montreal.

Adaptation, Psychological↗
PubMed1998

Parent-child agreement on refugee children's psychiatric symptoms: a transcultural perspective.

OBJECTIVE: To compare the types and rates of psychiatric symptoms of young Central American and Cambodian refugees, as reported by both parents and children, and to examine parent-child agreement in reporting symptoms. METHOD: Interviews were conducted with 123 children aged 8 to 12 years and 158 adolescents aged 12 to 16 years and their parents. Parents assessed psychiatric symptoms via the Child Behavior Checklist, the 8- to 12-year-olds responded to the Dominic, and the adolescents answered the Youth Self-Report. Means of Internalizing and Externalizing scores were compared on the basis of ethnic origin, parent's sex, and child's sex, as were the Spearman correlation coefficients of parents' and children's ratings. RESULTS: The Cambodian parents reported few symptoms in their children, and the Central Americans reported almost as many symptoms as did parents in U.S. clinical samples. The Cambodian children reported less symptoms than the Central Americans, but the interethnic difference was not significant in the adolescents' self-reports. Parent-child agreement varied considerably by sex and ethnic origin of the informant. CONCLUSIONS: The results underscore the need to involve multiple informants in assessing psychiatric symptoms of refugee children in spite of the difficulties inherent in field research with this population. They also show that data on multiple informants gathered from Western samples are not universally valid.

Adolescent↗
PubMed1998

In vivo inaccessibility of somatostatin receptors to 111In-pentreotide in primary renal cell carcinoma.

The presence of somatostatin receptors on human renal cell carcinomas in surgically removed kidneys has been demonstrated by autoradiography. The aim of this study was to detect to in vivo presence of somatostatin receptors in primary renal tumours and their possible metastases before surgery, using 111In-pentreotide scintigraphy. 201Tl was used as a sensitive tumour-seeking agent with blood flow-dependent uptake. Fifteen patients were imaged before surgical removal of the renal tumour. Thirteen tumours were malignant. The large tumours (more than 4 cm in diameter) did not accumulate 111In-pentreotide or 201Tl. In contrast, the single small tumour accumulated both tracers. A scalp skin metastasis was demonstrated in one patient by 201Tl and 111In-pentreotide uptake. In one case, known lung metastases were visualized with both 201Tl and 111In-pentreotide, but the lung metastases of another three patients as well as one case of epidural metastasis were not identified. In one patient with a photopaenic lesion, positive labelling of the surgically removed tumour was demonstrated by in vitro autoradiography. Somatostatin receptor scintigraphy with 111In-pentreotide appears to have little value for the detection of metastases in patients with renal cell carcinoma, as some metastases (especially those of the lungs) were missed. The absence of 111In-pentreotide uptake by large primary tumours is an interesting finding, suggesting inaccessibility of these very large tumours to drugs.

Adult↗
PubMed1997

Long terminal repeat and nef gene variants of human immunodeficiency virus type 1 in perinatally infected long-term survivors and rapid progressors.

HIV-1 sequences from perinatally infected children were analyzed in the long terminal repeat (LTR) region and nef in order to investigate associations of viral variation and disease progression. Four long-term survivors who reached 10 years of age or older, and four rapid progressors who survived less than 2 years, participated in this study. LTR sequences of multiple independent viral variants from each individual were compared. No sequence pattern within the LTR consistently distinguished long-term survivors from rapid progressors or vice versa. Deletions and insertions within transcription factor binding sites of the LTR and nef ranging from 8 to 341 bp were found in viral variants from the eldest long-term survivor (LTS047). These deletions and duplications may be associated with the survival of LTS047 via an unknown mechanism. Among all children in this study, the sites in the untranslated region (NF-kappaB, SP1, and TATA box) were more conserved than the sites in the nef/LTR overlap region (NFAT, purine-rich region, USF, TCF1alpha), reflecting the importance of the sites in the untranslated region for viral replication. A mutation in the E box motif within the USF site among the sequences from a long-term survivor (LTS113) is predicted to disrupt protein binding and may be associated with slow disease progression. Mutations of the SP1-III site in a rapid progressor (RP056) indicate that this site is not necessary for rapid disease progression.

Amino Acid Sequence↗
PubMed1997

CBP70, a glycosylated nuclear lectin.

Some years ago, a lectin designated CBP70 that recognized glucose (Glc) but had a stronger affinity for N-acetylglucosamine (GlcNAc), was first isolated from HL60 cell nuclei. Recently, a cytoplasmic form of this lectin was described, and one 82 kDa nuclear ligand was characterized for the nuclear CBP70. In the present study, the use of Pronase digestion and the trifluoromethanesulphonic acid (TFMS) procedure strongly suggest that the nuclear and the cytoplasmic CBP70 have a same 23 kDa polypeptide backbone and, consequently, could be the same protein. In order to know the protein better and to obtain the best recombinant possible in the future, the post-translational modification of the nuclear and cytoplasmic CBP70 was analyzed in terms of glycosylation. Severals lines of evidence indicate that both forms of CBP70 are N- and O-glycosylated. Surprisingly, this glycosylation pattern differs between the two forms, as revealed by beta-elimination, hydrazinolysis, peptide-N-glycosydase F (PNGase F), and TFMS reactions. The two preparations were analyzed by affinity chromatography on immobilized lectins [Ricinus communis-l agglutinin (RCA-I), Arachis hypogaea agglutinin (PNA), Galanthus nivalis agglutinin (GNA), and wheat germ agglutinin (WGA)] and by lectin-blotting analysis Sambucus nigra agglutinin (SNA), Maackia amurensis agglutinin (MAA), Lotus tetragonolobus (Lotus), succinylated-WGA, and Psathyrella velutina agglutinin (PVA)]. Both forms of CBP70 have the following sugar moities: terminal beta Gal residues, Gal beta 1-3 GalNAc, Man alpha 1-3 Man, sialic acid alpha 2-6 linked to Gal or GalNAc; and sialic acid alpha 2-3 linked to Gal. However, only nuclear CBP70 have terminal GlcNAc and alpha-L-fucose residues. All these data are consistent with the fact that different glycosylation pattern found for each form of CBP70 might act as a complementary signal for cellular targeting.

Agglutinins↗
PubMed1997

The influence of culture and context on the pre- and post-migration experience of school-aged refugees from Central America and Southeast Asia in Canada.

Pre- and post-migration contexts of refugee children from Central America and Southeast Asia were compared. The results suggest that the culture of origin radically modulates the relationship between the pre-migration experience and the developing post-migration universe. In the case of the Central American children, the state-sponsored violence suffered in the country of origin is strongly associated with subsequent family conflicts, whereas in the case of the Southeast Asians, conflict is associated with an active social network in the community of origin, suggesting that there is a delicate balance between the support provided and the burden imposed by the extended family.

Anxiety, Separation↗
PubMed1997

Characterization of a putative 82 kDa nuclear ligand for the N-acetylglucosamine-binding protein CBP70.

Since nuclear lectins were first characterized several years ago, six lectins have been isolated. Furthermore, the existence of nuclear glycoproteins containing N-linked complex-oligosaccharide chains or O-linked GlcNAc residues was evidenced. These latter are abundant in the nucleus and are well-studied so far. The presence of both glycoprotein and lectin in the cell nucleus led us to postulate that these two proteins could interact and play a role in some nuclear activities such as the modulation of transcription and/or nuclear cytoplasmic exchanges or by the disruption of protein-protein interactions. In such context, the recent data concerning the GlcNAc-binding activity of CBP70 argued this postulate. However, to study the possible role of a glycoprotein-lectin complex, it was critical to isolate the two partners. Because CBP70 was also a cytoplasmic protein, the lectin was isolated in both cytoplasmic and nuclear compartments in order to investigate the putative ligand in the two cellular compartments. The results obtained with cross-linking experiments on isolated and membranedepleted nuclei incubated with the CBP70 bearing an iodinatable, cleavable, photoreactive cross-linking agent (sulfosuccinimidyl 2-(p-azidosalicylamido) ethyl-1,3'-dithiopropionate) and immunoprecipitation experiments with polyclonal antibodies raised against CBP70, revealed that both nuclear and cytoplasmic CBP70 have the same 82 kDa nuclear ligand which is absent in the cytoplasmic fraction. In addition, this ligand is glycosylated, containing GlcNAc residues, and, therefore, the complex between CBP70 and the 82 kDa polypeptide could be due to a glycoprotein-lectin interaction. These results raised the possibility that nuclear glycoprotein-lectin interaction could be involved in nuclear activities.

Cell Extracts↗
PubMed1997

Microinjection of bivalve eggs: application in genetics.

New strategies for embryonic manipulation have been developed in recent years through plant and animal research. However, research on marine invertebrate embryos has suffered from a lack of basic tools, such as microinjection. Here we present a technique developed for microinjecting eggs and embryos of the oyster Crassostrea gigas and the mussel Mytilus edulis. In experimental trials, approximately 40% of microinjected embryos survived. This technique was used to microinject beta-galactosidase, for which specific detection techniques were developed. A reporter construct (CMV-beta) based on a promoter of cytomegalovirus linked to the beta-galactosidase-encoding gene was then microinjected, and the expression level of this construct was monitored. The suitability of this technique is discussed in terms of its application to the manipulation of bivalve mollusks in pathology and genetics.

Animals↗
PubMed1996

School performance and emotional problems in refugee children.

The relationship between school performance and emotional problems was assessed in a general population sample of refugee children from Southeast Asia and Central America. Results suggested that learning difficulties and levels of academic achievement were associated with emotional problems in both groups but that, despite comparable academic records, remedial measures were more often prescribed for Central American children.

Achievement↗
PubMed1996

[The Free School and Hospital in Paris with respect to dentistry: the dental school in France].

It is here recalled and described the foundation of the Free School and Hospital of Paris in 1880, including their financial project and the different options for their setting up and begin their courses. By the way we'd like to report that our first professor at the School of Dentistry of Buenos Aires, Dr. Nicasio Etchepareborda, studied at that Free Dental school, getting his professional degree in 1882. This certificate, donated to the Museum of our Faculty by his family, was dated November 1st 1882.

France↗
PubMed1995

Residents' perceptions of transcultural psychiatric practice.

A questionnaire was distributed to 190 psychiatry residents to analyze the impact of three factors on residents' perceptions of their transcultural practice: cultural identity of residents; degree of exposure to patients from different cultures; and training in cultural psychiatry. Results suggest that residents' perceptions vary according to the resident's cultural origin. The training in psychiatry and the degree of exposure to patients from different cultures had no significant influence on the residents' perceptions. Overall these results emphasize the necessity to revise the cultural content of residents' psychiatry curriculum to, among other things, raise residents' awareness of their own cultural identity.

Adult↗
PubMed1995

Future of biotechnology-based control of disease in marine invertebrates.

Infectious disease is the single most devastating problem in mollusc and shrimp aquaculture. Pathogens causing the greatest problems have been identified as viruses, prokaryotes, and protozoans. Two approaches employing methods of biotechnology have been proposed to prevent, manage, and control mollusc and shrimp diseases. The first is development of a diagnostic scheme for detection and identification of pathogens, using molecular probes. This offers the opportunity for prophylactic measures to be taken. Molecular probes have been prepared for the major pathogens of molluscs, but in the case of shrimp pathogens, only a few are available. Monoclonal antibodies have also been prepared and are used in immunodiagnosis, e.g., immunofluorescence detection. Such diagnostic tools are relatively new to aquaculture, but have enormous potential. A second approach to the control of disease in marine invertebrates, notably shrimp, involves use of genetically transformed strains resistant to specific pathogens. Pathogen-resistant transgenic animals have been developed, but such research has only just begun for molluscs and shrimp. Transfection methods applied to mollusc and shrimp embryos have been successful, with preliminary data showing efficiency of heterologous promoters in controlling expression of reporter genes. Other transformation systems also show promise, including transposable elements and densoviruses.

Animal Diseases↗
PubMed1994

Rapid filtration studies of the effect of cytosolic Ca2+ on inositol 1,4,5-trisphosphate-induced 45Ca2+ release from cerebellar microsomes.

Using microsomal membrane vesicles derived from sheep cerebellum, we measured the rate of inositol 1,4,5-trisphosphate (InsP3)-dependent 45Ca2+ efflux from 45Ca(2+)-loaded compartments during rapid perfusion with a medium containing InsP3 and various concentrations of free 40Ca2+ on the cytosolic side (pH 7.1, 5 mM Mg2+, in the absence of ATP at 20 degrees C). At 0.15 microM InsP3 and pCa 6.5, half-45Ca2+ release was attained within less than 200 ms. At low Ca2+ concentrations, the initial rate of 45Ca2+ release depended smoothly on InsP3 concentration, and InsP3 activated release with moderate positive cooperativity. Preliminary experiments performed at various free 40Ca2+ concentrations were consistent with a bell-shaped 40Ca2+ dependence of 45Ca2+ release. In the range of micromolar or higher free 40Ca2+ concentrations, the apparent inhibition of 45Ca2+ release was dependent on InsP3 concentration, and 45Ca2+ release for intermediate InsP3 concentrations was transient; under selected conditions, a second perfusion period, identical to the first one but separated from it by a short recovery period, was found to allow renewed 45Ca2+ efflux. At high Ca2+ concentration, fast reversible Ca(2+)-dependent desensitization of the channel, and not heterogeneity, was therefore responsible for the termination of InsP3-triggered 45Ca2+ efflux at submaximal concentrations of InsP3. At lower Ca2+ concentrations, a large fraction of the apparent activating effect of submicromolar 40Ca2+ concentrations on 45Ca2+ efflux that we had observed in the preliminary experiments proved to be the artifactual consequence of an inhibitory effect exerted by metal-free Ca2+ chelators on InsP3-dependent efflux at nanomolar 40Ca2+ concentrations. 1,2-Bis(2-aminophenoxy)ethane-N,N,N'-N'-tetraacetic acid, EGTA, and fluo-3 were all effective inhibitors. When this inhibition was taken into account, a rise in free 40Ca2+ concentration from 30 to 300 nM only weakly enhanced 45Ca2+ fluxes in the presence of a low concentration of InsP3. As a result, submicromolar free 40Ca2+ appears to be only a poor activator of InsP3-induced Ca2+ release under these experimental conditions.

Adenosine Triphosphate↗