Search PubMed⌕ Search

Biomedical subjects

C Perreault

Publications and source records attributed to C Perreault.

At least 73 records · Page 4Linked to original sources
PubMed1988

Bone marrow transplantation for myelodysplastic syndromes.

Eight patients with myelodysplastic syndromes (MDS) were treated with bone marrow transplantation (BMT). Median age was 34.5 years and ranged between 3 and 45. FAB diagnosis was refractory anaemia (RA) in three, RA with excess of blasts (RAEB) in four and RAEB in transformation (RAEB-t) in one case. Four patients were prepared with cyclophosphamide and total body irradiation whilst the other four received busulphan and cyclophosphamide. Engraftment was documented in seven of eight patients. Two patients died from complications related to the procedure. One had early veno-occlusive disease of the liver whilst the other died 46 months after BMT from pulmonary fibrosis. One patient died from recurrent disease 11 months after BMT. Five patients are alive and in complete remission 9-35 months post-transplantation. Four of these patients have a Karnofsky score greater than or equal to 90%. These results suggest that BMT can induce prolonged disease-free survival in patients under 50 years of age. If a compatible donor is available, marrow transplantation should be seriously considered in the treatment of MDS.

Adult↗
PubMed1987

[Exploratory analysis of mental health in an unemployment situation : the case of workers in the manufacturing sector of eastern Montréal (Part 1).].

The objectives of this research are to take the inventory of the psychosocial mechanisms that promote the unemployed individual's equilibrium, and to draw the profile of mental health practices existing in a homogenous group of unemployed persons in the manufacturing sector. In the first part, the authors review the methodology used in the course of their study and present a global analysis of the daily experiences of unemployed individuals, by showing the means they have put into effect to ensure their subsistance and that of their family. The second part seeks to provide an original viewpoint to the issue of mental health. The analysis includes an inventory of mental health practices followed by a brief description of techniques used to establish mutual aid networks.

English Abstract↗
PubMed1987

[Exploratory analysis of practices in mental health in an unemployment situation : the case of workers in the manufacturing sector of Eastern Montréal (Part 2).].

In this article, the authors present results stemming from the exploratory analysis of mental health practices that are used by a group of unemployed workers. The study presents five types of practices: the enhancement of the unemployed individual's experience, institutional consultation within the health care system, anticipation, self-actualization and changes to the unemployment situation. These various mental health practices, demonstrated among a homogenous group of unemployed individuals in the manufacturing sector, promote a wider reflexion of intervention methods.

English Abstract↗
PubMed1986

Interstitial deletion of the long arm of chromosome 5 (5q-) in leukemia and other hematological disorders: clinical and biological relevance of variable breakpoint patterns.

From January 1983 to January 1985, we have found a deletion of the long arm of chromosome 5 (5q-) in the bone marrow cells of 8 patients; they represent consecutive patients referred to our institution for investigation and treatment of the following hematological disorders in whom the 5q- abnormality was found: acute nonlymphocytic leukemia (ANLL) (3), refractory anemia with excess blasts (RAEB) (2), preleukemia (PL) (1), sideroblastic anemia (SA) (1), refractory anemia (RA) (1). The deletion proved to be interstitial in all patients, with 3 different breakpoint patterns emerging: q13q33, q11.2q21, q11.2q33. Proximal breakpoint q11.2 was found only in patients with an initial diagnosis of ANLL. The common region deleted in all patients was comprised between bands q13q21. The clinical relevance and biological meaning of the heterogeneity of proximal and distal breakpoints found in this study are discussed.

Adult↗
PubMed1986

Characterization of human thymic dendritic cells in culture.

Cells with dendritic shape, the so-called dendritic cells (DCs), have been described in many tissues. In order to characterize one DCs population, normal human thymus specimens were obtained from children undergoing cardiovascular surgery. These specimens were either put in culture or fixed for in situ ultrastructural, immunocytochemical and cytochemical studies. In culture, DCs could be differentiated from other non-lymphoid cell populations. They presented long, fine processes and an irregular nucleus. Like interdigitating cells (IDCs) in situ, their cytoplasm contained many free ribosomes and mitochondria, and a well-developed endoplasmic reticulum and Golgi complex. They showed a variable number of tubulovesicular structures and membrane-bound dark homogeneous granules. They never displayed phagolysosomes, tonofilaments or desmosomes. They were Ia+, ATPase+, S-100 protein+, vimentin+, esterase-, lysozyme-, and cytokeratin- cells. Macrophages were easily identified by their numerous lysosomes and large phagolysosomes. They were esterase+, lysozyme+, vimentin+, ATPase +/-, S-100 protein- and cytokeratin-. Although they were Ia+, membrane labelling was not as important as on DC's membrane. In situ, S-100 protein-positive cells had a dendritic shape and were located mainly in medullary regions and at the cortico-medullary border. The staining was diffused both in the nucleus and in the cytoplasm. Lysozyme-positive cells were randomly distributed in the cortex, the medulla and the connective septa. They were round cells and the staining was intracytoplasmic. These observations demonstrate that DCs can be isolated in human thymic cultures, and they suggest that these cells correspond to IDCs in situ. They also provide evidence to suggest that DCs and macrophages are two distinct cellular populations.

Adenosine Triphosphatases↗
PubMed1986

Characterization of plasma cell populations at autopsy after human allogeneic bone marrow transplantation.

Postmortem fixed tissue sections of the lymphoid and digestive systems of eight consecutive leukemic patients dying of various diseases after bone marrow transplantation (BMT) were analyzed for the presence of the heavy chains gamma, alpha, mu, delta, and epsilon and light chains kappa and lambda, with the use of a standard immunoperoxidase method. Two distinct types of plasma cell populations were found. The first type was a widely distributed polyclonal plasma cell population, lacking IgD-positive plasma cells and germinal centers. The second type of plasma cell population, found in 6 of 8 patients, was a group of monoclonal plasma cell populations positive for the heavy chains gamma, alpha, mu, or delta. Recent immunohistologic observations of the human lymph node suggest that the first type of polyclonal plasma cell population could arise from a nonspecific expansion of sIgM+, sIgD- B lymphocytes. The lack of germinal centers, a structure closely involved in specific-antibody production, may correlate with the poor specific-antibody response documented in patients after BMT. The monoclonal plasma cell populations, found with an unexpectedly high frequency, are probably related to a functional T-cell defect.

Adolescent↗
PubMed1986

Demonstration of OKT6 antigen on human thymic dendritic cells in culture.

In situ, two types of dendritic cells (DCs) have been characterized in more detail: the interdigitating DCs of peripheral lymphoid tissues and the epidermal Langerhans cells. In order to characterize human thymic DCs, normal human thymus specimens were obtained from children undergoing cardiovascular surgery. In culture, DCs could be easily differentiated from macrophages and epithelial cells by their long fine processes, irregular nucleus, and dark, membrane-bound granules. By immunoelectron microscopy, using the protein A-gold and the avidin-biotinperoxidase complex techniques, cultured DCs were strongly labeled with anti-Ia and anti-OKT6 monoclonal antibodies. These results demonstrate that the phenotype of thymic DCs is similar to that of epidermal Langerhans cells and suggest that they may belong to the same cellular lineage.

Antibodies, Monoclonal↗
PubMed1985

Lymphoid interstitial pneumonia after allogeneic bone marrow transplantation. A possible manifestation of chronic graft-versus-host disease.

Interstitial pneumonia (IP) is a frequent and serious complication of bone marrow transplantation with a median time of onset about 2 months posttransplant. Most cases result either from toxicity of radiation and chemotherapy or from infection with pathogens such as cytomegalovirus. Described are two patients with chronic graft-versus-host disease (GVHD) who presented with late-onset IP 242 and 632 days posttransplant. Histologic examination of lung biopsy specimens disclosed a lymphoid interstitial pneumonia (LIP) in both cases. The major lymphocyte subset found in bronchoalveolar lavages and lung tissue was OKT8(+) and showed a positive dot staining for acid phosphatase. Contrary to peripheral blood mononuclear cells, most OKT8(+) lymphocytes in the lungs were OKT3(-). Since acute GVHD lesions are mediated mainly by cytotoxic T-lymphocytes, our data suggest that LIP in marrow-grafted patients may be a manifestation of chronic GVHD. It should be distinguished from the more common types of IP encountered following bone marrow transplantation.

Acid Phosphatase↗
PubMed1985

Serum immunoglobulin levels following allogeneic bone marrow transplantation.

In order to study the posttransplant evolution of serum immunoglobulin levels, we measured serum IgG, IgA and IgM levels in 50 recipients of allogeneic bone marrow before transplantation and at different intervals thereafter (days 39, 120, 365 and 730). IgG and IgM levels were depressed for 1 year and IgA levels for 2 years posttransplant. Immunoglobulin deficiency was more severe and prolonged in patients with graft versus-host-disease. Hypogammaglobulinemia may contribute to the frequent infections observed in these patients, especially those with chronic graft-versus-host disease.

Adolescent↗
PubMed1985

14q+ abnormality with probable t(8;14)(q24;q32) in a young Haitian immigrant with acquired immunodeficiency syndrome and concomitant Burkitt's-like lymphoma.

Cytogenetic analyses were carried out in a young Haitian immigrant with acquired immunodeficiency syndrome and concomitant Burkitt's-like lymphoma associated with massive bone marrow infiltration. A characteristic 14q+ abnormality was found in all bone marrow cells examined. Although chromosome abnormality involving band 8q24 was not evident in all the cells examined, some karyotypes show that the typical t(8;14)(q24;q32) is most probably present. No other complex rearrangements could be identified. This is the first report of concomitant acquired immunodeficiency syndrome and Burkitt's-like lymphoma in the Haitian community. Our cytogenetic findings provide further evidence for the role of specific chromosomal rearrangements in Burkitt's-like lymphoma oncogenesis in the setting of acquired immunodeficiency syndrome.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Persistence of host Langerhans cells following allogeneic bone marrow transplantation: possible relationship with acute graft-versus-host disease.

Langerhans cells (LC) are bone marrow-derived dendritic antigen-presenting cells found in the epidermis. In an effort to determine the origin (host versus donor) of LC at different intervals following bone marrow transplantation, we performed skin biopsies in 16 recipients of sex-mismatched marrow. LC were identified using monoclonal antibody OKT6 in an indirect immunoperoxidase assay and their donor or host origin determined according to the presence or absence of Y body. The presence of Y-positive (donor) LC could be demonstrated in all (6/6) skin biopsies of female recipients of male marrow tested between days 39 and 730 post-transplant. Persistence of host LC in male recipients of female marrow was documented in all (6/6) recipients studied on day 39 and in two out of seven patients tested on day 120 post-transplant. From day 365 onward, no residual host LC could be detected, suggesting that by this time all epidermal LC are donor-derived. Our study demonstrates that host LC usually persist for 39 and up to 120 d following bone marrow transplantation. The relevance of this observation to the possible role of LC and other host dendritic antigen-presenting cells in the graft-versus-host reaction is discussed.

Acute Disease↗
PubMed1985

Chronic myeloid leukemia with an unusual simple variant translocation: t(22;22)(q13;q11).

A second example of chronic myeloid leukemia (CML) with the unusual simple variant t(22;22) is reported. In this case, break points are readily identified at bands q13 and q11. The nature of simple variant translocations in CML is discussed in the light of recent knowledge acquired from in situ hybridization of c-Ableson proto-oncogen DNA probes to metaphase spreads of CML patients.

Adult↗