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Biomedical subjects

C Greenland

Publications and source records attributed to C Greenland.

At least 19 recordsLinked to original sources
PubMed2001

Expression of the oncogenic NPM-ALK chimeric protein in human lymphoid T-cells inhibits drug-induced, but not Fas-induced apoptosis.

Anaplastic large cell lymphomas (ALCLs) are frequently associated with the t(2;5)(p23;q35) translocation, leading to the expression of NPM-ALK, a fusion protein linking nucleophosmin and anaplastic lymphoma kinase, a receptor tyrosine kinase. In ALCLs, dimerization of NPM-ALK leads to constitutive autophosphorylation and activation of the kinase, necessary for NPM-ALK oncogenicity. To investigate whether NPM-ALK, like other oncogenic tyrosine kinases, can inhibit drug-induced apoptosis, we permanently transfected NPM-ALK into Jurkat T-cells. As in ALCLs, NPM-ALK was expressed as a constitutively kinase-active 80 kDa protein, and could be detected by immunocytochemistry in nucleoli, nuclei and cytoplasm. Doxorubicin-induced apoptosis (assessed by cell morphology and annexin V-FITC binding) was significantly inhibited in two independent NPM-ALK-expressing clones (5.2+/-1.8 and 7.5+/-0.8% apoptosis), compared to control vector-transduced cells (36+/-6.7%). Similar results were observed with etoposide. In contrast, Fas-induced apoptosis was not inhibited. Cytochrome c release into the cytosol was delayed in doxorubicin-, but not anti-Fas-treated transfectant cells, indicating that apoptosis inhibition occurred upstream of mitochondrial events. Using NPM-ALK mutants, we demonstrated that inhibition of drug-induced apoptosis: (1) requires functional kinase activity, (2) does not involve phospholipase C-gamma, essential for NPM-ALK-mediated mitogenicity and (3) appears to be phosphoinositide 3-kinase independent, despite a strong Akt/PKB activation observed in wild type NPM-ALK-expressing cells. These results suggest that the NPM-ALK antiapoptotic and mitogenic pathways are distinct.

Adenosine Triphosphate↗
PubMed2001

Anaplastic large cell lymphoma with the t(2;5)(p23;q35) NPM/ALK chromosomal translocation and duplication of the short arm of the non-translocated chromosome 2 involving the full length of the ALK gene.

This report describes a case of anaplastic large cell lymphoma with the canonical t(2;5)(p23;q35) translocation in association with duplication of the short arm of the non-translocated chromosome 2, as demonstrated by two colour fluorescence in situ hybridisation. Because the tumour cells were tetraploid, these abnormalities were in duplicate, with four copies of the full length ALK gene and two copies of the t(2;5)(p23;q35) translocation. Despite multiple copies of the normal ALK gene, immunohistochemical, reverse transcriptase polymerase chain reaction, and western blot analysis demonstrated that only the fusion gene NPM/ALK was expressed and that normal ALK genes remained silent. Although based on a single case, these data indicate that structural rather than numerical abnormalities of the ALK gene are implicated in the pathogenesis of anaplastic large cell lymphomas.

Anaplastic Lymphoma Kinase↗
PubMed2000

Ligation of the CD44 adhesion molecule inhibits drug-induced apoptosis in human myeloid leukemia cells.

Adhesion molecules can improve hematopoietic cell survival; however, their role in leukemic cell resistance to drug-induced apoptosis is poorly documented. The CD44 adhesion molecule is strongly expressed on acute myeloid leukemia (AML) blasts. Using 2 myeloid cell lines, HL60 and NB4, evidence is presented that prior incubation with the CD44-specific monoclonal antibody (mAb) A3D8, reported to induce differentiation of AML blasts, significantly decreases apoptosis induced by 3 drugs used in AML chemotherapy: daunorubicin (DNR), mitoxantrone, and etoposide. In addition, in HL60 cells, CD44 ligation with A3D8 mAb fully abrogates the DNR-triggered generation of ceramide, a lipid second messenger involved in the DNR apoptotic signaling pathway. Moreover, results show that the A3D8 mAb and Bcl-2 additively inhibit DNR-induced apoptosis in HL60 cells overexpressing Bcl-2. These results suggest that, to eradicate AML blasts, the differentiation-inducing anti-CD44 mAb A3D8 should not be administered prior to apoptosis-inducing drugs.

Apoptosis↗
PubMed2000

Further demonstration of the diversity of chromosomal changes involving 2p23 in ALK-positive lymphoma: 2 cases expressing ALK kinase fused to CLTCL (clathrin chain polypeptide-like).

Anaplastic lymphoma kinase (ALK)-positive lymphomas are characterized by expression of a hybrid protein, comprising the cytoplasmic portion of the ALK tyrosine kinase fused to a partner protein. This hybrid kinase is often encoded by the nucleophosmin (NPM) NPM-ALK fusion gene resulting from the (2;5)(p23;q35) chromosomal translocation. However, the ALK gene at 2p23 may also be involved in 2 variant translocations, namely t(1;2)(q25;p23) and t(2;3)(p23;q21), which create the TPM3-ALK and TFG-ALK fusion genes, respectively. We report here 2 lymphomas with an unusual finely granular cytoplasmic ALK staining pattern, clearly different from the pattern observed in ALK-positive lymphomas carrying NPM-ALK or its variants. A cloned complementary DNA sequence from 1 of these 2 lymphomas contained the ALK gene fused to the second clathrin heavy chain gene (also referred to as clathrin heavy polypeptide-like gene) (CLTCL). The distinctive granular cytoplasmic staining pattern for ALK was likely to be due to binding of the fusion protein to clathrin-coated vesicles. The CLTCL gene is constitutively expressed in lymphoid cells and therefore presumably contributes an active promoter for the CLTCL-ALK gene. The fusion protein had a molecular weight (250 kd) that differs from all known ALK products, and it was autophosphorylated in an in vitro kinase assay, confirming that it is constitutively active and hence capable of contributing to malignant transformation. These 2 cases, therefore, represent a hitherto undescribed mechanism of ALK activation in lymphoma and further illustrate the diversity of fusion partners for the ALK gene.

Amino Acid Sequence↗
PubMed1983

Chronic psychiatric patients in the community.

A feasibility study is presented which describes a cohort of 102 chronic psychiatric patients. The cases were selected on the criterion of four or more new admissions to psychiatric services in the Hamilton-Wentworth region during the year 1977. The group was predominately in the age 20-39 year range and both sexes were represented about equally. The diagnostic labels were personality disorder, schizophrenia, depression and alcoholism in descending order of frequency. The large majority were socially isolated and had contact with social agencies and the police. Seven deaths occurred in the cohort during the year of study.

Adult↗
PubMed1981

Institutional care of the mentally disordered in Canada--a 17th century record.

"General hospitals" for the care of the helpless poor, the aged and infirm, lunatics and idiots, which were developed in the mid-17th century by Louis XIV of France, soon spread to the colony in New France. Francois Charon, a wealthy businessman, built the Hôpital Général de Ville Marie, Montreal, which was opened in 1694 to care for impoverished and helpless men. The Hospital Register, discovered in the Archives of the Soeurs Grises, Montreal, provides details of the patients' names, dates of and reasons for admission and the dates of discharge or death. An analysis of the Register, covering the 45 years of the Charon period, reveals that among the 66 boys and men admitted, from 1694 to 1738, at least seven inmates suffered from some form of mental disorder or retardation. This suggests that the Hôpital Général de Ville Marie, together with the Hôpital Général de Québec, were the first Canadian institutions to provide care for the mentally disordered. Pierre Chevallier, who was retarded, lived in the hospital for 44 years until his death at the age of 85. The length of stay in the hospital indicates that the early settlers of New France were men of robust constitution and that the regime provided by the Frères Charon was physically as well as spiritually sustaining.

Adult↗
PubMed1978

William Henry Jackson (1861--1952): Riel's secretary: another case of involuntary commitment?

Although there have been many studies of the trial of Louis Riel, following the 1885 rebellion, much less attention has been paid to the fate of his secretary William Henry Jackson, who was charged with "treason-felony" and found not guilty, reason of insanity. In an effort to throw some new light on this neglected aspect of midico-legal history, this paper describes the intense political and religious relationship between Riel and his secretary which culminated in the onset of Jackson's mental illness. After a trial lasting less than half an hour, Jackson was committed to the "Selkirk Asylum" under a warrant of the then Lieutenant-Governor. Two weeks before Riel was executed, Jackson escaped from hospital and made his way into the U.S.A. No attempt was made to capture him. Jackson, having changed his name to Honoré Jaxon, became a labour organizer. He died in the psychopathic ward of Bellevue Hospital in New York on 10th January, 1952 at the age of ninety.

Adult↗
PubMed1977

Psychiatry and the dangerous sexual offender.

A study of Dangerous Sexual Offenders, undertaken for the Canadian Law Reform Commission, reveals that about one-third of DSOs seriously threatened or actually endangered the life of the victim. One-third were moderately assaultive. The remainder, mostly homosexual pedophiles, were offensive but not physically violent. The role of psychiatrists, employed by the Crown in the process of securing an indeterminate sentence, is described. Most of them did not declare their role as "double-agents". Their expert testimony before the Courts also revealed a failure to discriminate between fact and opinion. Individual prejudice was, not infrequently, presented as the wisdom of the psychiatric profession. The life of DSOs in Canadian penitentiaries, is likely to be exceedingly brutal. Four of them have been murdured while in custody. Others have killed themselves or made determined attempts to do so. Since it is obviously unethical for psychiatrists to participate in any procedure which is likely to result in harm or the death of an individual, the author urges the Canadian Psychiatric Association to support the Law Reform Commissions' condemnation of the DSO legislation. As an interim measure psychiatrists should be urged not to collaborate in DSO cases.

Adolescent↗