The evaluation of transferred health care services in Wunnimin Lake, Wapekeka and Kingfisher Lake First Nations: a nursing perspective

The Canadian federal government initiated the policy to transfer administrative control of health services to First Nations communities in the late 1980s. While there are outstanding issues concerning the implementation of the policy, many communities consider this an opportunity to improve the health of First Nations people and the work environment of health care providers. This paper reports on the evaluation of the process of transfer of health services experienced by three communities in northwestern Ontario, Canada, focusing on nursing services. Based on interviews with health care providers and community members, the overall assessment was that transfer had successfully addressed chronic issues relating to the working conditions of nurses and problems of recruitment and retention.

Preparation of alpha-(2,2-diphenylhydrazino)lactones and related compounds by radical cyclization: use of glyoxylic acid hydrazone derivatives

Glyoxylic acid diphenylhydrazone (2a) and the corresponding O-benzyloxime (2b) are easily esterified in high yield by beta-bromo alcohols. The resulting esters undergo radical cyclization to alpha-(2,2-diphenylhydrazino)- or alpha-[(phenylmethoxy)amino]lactones on treatment with tributyltin hydride. Esters for radical cyclization were also made using a beta-(phenylseleno) alcohol and an enol ether. Several derivatives of glyoxylic acid were evaluated, but none was as effective as 2a or 2b. The imine 28 was prepared by an indirect route; it undergoes radical cyclization with displacement of the nitrogen substituent (28 --> 30) so that an alpha-amino lactone can be generated by acid hydrolysis of the cyclization product.

The utilization of antenatal services in remote Manitoba First Nations communities

The purpose of this study was to describe the utilization of antenatal services by First Nations women in four northern Manitoba communities between January, 1996 and December 1996, and to explore possible relationships between the women's behaviors and antenatal clinic attendance. This study indicated that First Nations women received an optimal level of antenatal service. On average, the women first came to the nursing station in the ninth week of pregnancy and saw the health care provider generally a nurse, ten times for routine visits before maternal evacuation. A minority of women, however, had fewer than five visits. The frequency of routine antenatal clinic attendance was explained by the linear multiple regression model. A higher number of past pregnancies was associated with a decrease in the number of routine antenatal visits, while the number of pregnancy losses predicted the number of visits, after other variables had been taken into account. Married marital status was a positive predictor for the early initiation of care, after past pregnancies and risk score have been taken into account.

Groucho/TLE/R-esp proteins associate with the nuclear matrix and repress RUNX (CBF(alpha)/AML/PEBP2(alpha)) dependent activation of tissue-specific gene transcription

The Runt related transcription factors RUNX (AML/CBF(alpha)/PEBP2(alpha)) are key regulators of hematopoiesis and osteogenesis. Using co-transfection experiments with four natural promoters, including those of the osteocalcin (OC), multi drug resistance (MDR), Rous Sarcoma Virus long terminal repeat (LTR), and bone sialoprotein (BSP) genes, we show that each of these promoters responds differently to the forced expression of RUNX proteins. However, the three RUNX subtypes (i.e. AML1, AML2, and AML3) regulate each promoter in a similar manner. Although the OC promoter is activated in a C terminus dependent manner, the MDR, LTR and BSP promoters are repressed by three distinct mechanisms, either independent of or involving the AML C terminus, or requiring only the conserved C-terminal pentapeptide VWRPY. Using yeast two hybrid assays we find that the C terminus of AML1 interacts with a Groucho/TLE/R-esp repressor protein. Co-expression assays reveal that TLE proteins repress AML dependent activation of OC gene transcription. Western and northern blot analyses suggest that TLE expression is regulated reciprocally with the levels of OC gene expression during osteoblast differentiation. Digital immunofluorescence microscopy results show that TLE1 and TLE2 are both associated with the nuclear matrix, and that a significant subset of each colocalizes with AML transcription factors. This co-localization of TLE and AML proteins is lost upon removing the C terminus of AML family members. Our findings indicate that suppression of AML-dependent gene activation by TLE proteins involves functional interactions with the C terminus of AML at the nuclear matrix in situ. Our data are consistent with the concept that the C termini of AML proteins support activation or repression of cell-type specific genes depending on the regulatory organization of the target promoter and subnuclear localization.

The t(8;21) chromosomal translocation in acute myelogenous leukemia modifies intranuclear targeting of the AML1/CBFalpha2 transcription factor

Targeting of gene regulatory factors to specific intranuclear sites may be critical for the accurate control of gene expression. The acute myelogenous leukemia 8;21 (AML1/ETO) fusion protein is encoded by a rearranged gene created by the ETO chromosomal translocation. This protein lacks the nuclear matrix-targeting signal that directs the AML1 protein to appropriate gene regulatory sites within the nucleus. Here we report that substitution of the chromosome 8-derived ETO protein for the multifunctional C terminus of AML1 precludes targeting of the factor to AML1 subnuclear domains. Instead, the AML1/ETO fusion protein is redirected by the ETO component to alternate nuclear matrix-associated foci. Our results link the ETO chromosomal translocation in AML with modifications in the intranuclear trafficking of the key hematopoietic regulatory factor, AML1. We conclude that misrouting of gene regulatory factors as a consequence of chromosomal translocations is an important characteristic of acute leukemias.

Crystal structure of the nuclear matrix targeting signal of the transcription factor acute myelogenous leukemia-1/polyoma enhancer-binding protein 2alphaB/core binding factor alpha2

Transcription factors of the acute myelogenous leukemia (AML)/polyoma enhancer-binding protein (PEBP2alpha)/core-binding factor alpha (CBFA) class are key transactivators of tissue-specific genes of the hematopoietic and bone lineages. AML-1/PEBP2alphaB/CBFA2 proteins participating in transcription are associated with the nuclear matrix. This association is solely dependent on a highly conserved C-terminal protein segment, designated the nuclear matrix targeting signal (NMTS). The NMTS of AML-1 is physically distinct from the nuclear localization signal, operates autonomously, and supports transactivation. Our data indicate that the related AML-3 and AML-2 proteins are also targeted to the nuclear matrix in situ by analogous C-terminal domains. Here we report the first crystal structure of an NMTS in an AML-1 segment fused to glutathione S-transferase. The model of the NMTS consists of two loops connected by a flexible U-shaped peptide chain.

Intranuclear targeting of AML/CBFalpha regulatory factors to nuclear matrix-associated transcriptional domains

The AML/CBFalpha runt transcription factors are key regulators of hematopoietic and bone tissue-specific gene expression. These factors contain a 31-amino acid nuclear matrix targeting signal that supports association with the nuclear matrix. We determined that the AML/CBFalpha factors must bind to the nuclear matrix to exert control of transcription. Fusing the nuclear matrix targeting signal to the GAL4 DNA binding domain transactivates a genomically integrated GAL4 responsive reporter gene. These data suggest that AML/CBFalpha must associate with the nuclear matrix to effect transcription. We used fluorescence labeling of epitope-tagged AML-1B (CBFA2) to show it colocalizes with a subset of hyperphosphorylated RNA polymerase II molecules concentrated in foci and linked to the nuclear matrix. This association of AML-1B with RNA polymerase II requires active transcription and a functional DNA binding domain. The nuclear matrix domains that contain AML-1B are distinct from SC35 RNA processing domains. Our results suggest two of the requirements for AML-dependent transcription initiation by RNA polymerase II are association of AML-1B with the nuclear matrix together with specific binding of AML to gene promoters.

CBFA2, frequently rearranged in leukemia, is not responsible for a familial leukemia syndrome

We have identified a family with an autosomal dominant platelet disorder with a predisposition for developing myeloid malignancies and have previously demonstrated linkage of this trait to chromosome 21q22.1-22.2. The nearest flanking markers, D21S1265 and D21S167, define the familial platelet disorder (FPD) critical region at a genetic distance of approximately 15.2 centimorgans and physical distance of approximately 6 megabases. This locus is of particular interest as it has previously been implicated in the pathogenesis of acute myelogenous leukemia (AML) and acute lymphoblastic leukemia (ALL) through the (8;21), (3;21) and (12;21) chromosomal translocations. In each of these cases, the CBFA2 gene is rearranged. As well, there is a potential association of this locus with the hematologic abnormalities seen in Down syndrome (trisomy 21). To identify the mutant gene in this pedigree, a positional cloning strategy has been undertaken. Several candidate genes map to this locus including: CBFA2, IFNAR1, IFNAR2, CRFB4, GART, SON, KCNE1, SCL5A3 and ATP50. CBFA2, as well as IFNAR1 and CRFB4, were the focus of initial mutational analysis efforts. In this report, we exclude CBFA2 as a candidate by Northern and Southern blotting, RNase protection, single-strand conformational polymorphism (SSCP), direct sequencing and gel-shift analysis. Exons of the IFNAR1 and CRFB4 genes were also analyzed by SSCP and demonstrated no evidence of mutation. SSCP analysis identified a new polymorphism in the second exon of the CRFB4 gene and confirmed a previously described polymorphism in the fourth exon of IFNAR1. Efforts are currently underway to delimit further the FPD critical region and to analyze the other known candidate genes, as well as novel candidate genes, which map to this locus.

Subcellular partitioning of transcription factors during osteoblast differentiation: developmental association of the AML/CBF alpha/PEBP2 alpha-related transcription factor-NMP-2 with the nuclear matrix

The subnuclear location of transcription factors may functionally contribute to the regulation of gene expression. Several classes of gene regulators associate with the nuclear matrix in a cell type, cell growth, or cell cycle related-manner. To understand control of nuclear matrix-transcription factor interactions during tissue development, we systematically analyzed the subnuclear partitioning of a panel of transcription factors (including NMP-1/YY-1, NMP-2/AML, AP-1, and SP-1) during osteoblast differentiation using biochemical fractionation and gel shift analyses. We show that nuclear matrix association of the tissue-specific AML transcription factor NMP-2, but not the ubiquitous transcription factor YY1, is developmentally upregulated during osteoblast differentiation. Moreover, we show that there are multiple AML isoforms in mature osteoblasts, consistent with the multiplicity of AML factors that are derived from different genes and alternatively spliced cDNAs. These AML isoforms include proteins derived from the AML-3 gene and partition between distinct subcellular compartments. We conclude that the selective partitioning of the YY1 and AML transcription factors with the nuclear matrix involves a discriminatory mechanism that targets different classes and specific isoforms of gene regulatory factors to the nuclear matrix at distinct developmental stages. Our results are consistent with a role for the nuclear matrix in regulating the expression of bone-tissue specific genes during development of the mature osteocytic phenotype.

Rearrangement of the AML1/CBFA2 gene in myeloid leukemia with the 3;21 translocation: expression of co-existing multiple chimeric genes with similar functions as transcriptional repressors, but with opposite tumorigenic properties

Several recurring chromosomal translocations involve the AML1 gene at 21q22 in myeloid leukemias resulting in fusion mRNAs and chimeric proteins between AML1 and a gene on the partner chromosome. AML1 corresponds to CBFA2, one of the DNA-binding subunits of the enhancer core binding factor CBF. Other CBF DNA-binding subunits are CBFA1 and CBFA3, also known as AML3 and AML2. AML1, AML2 and AML3 are each characterized by a conserved domain at the amino end, the runt domain, that is necessary for DNA-binding and protein dimerization, and by a transactivation domain at the carboxyl end. AML1 was first identified as the gene located at the breakpoint junction of the 8;21 translocation associated with acute myeloid leukemia. The t(8;21)(q22;q22) interrupts AML1 after the runt homology domain, and fuses the 5' part of AML1 to almost all of ETO, the partner gene on chromosome 8. AML1 is an activator of several myeloid promoters; however, the chimeric AML1/ETO is a strong repressor of some AML1-dependent promoters. AML1 is also involved in the t(3;21)(q26;q22), that occurs in myeloid leukemias primarily following treatment with topoisomerase II inhibitors. We have studied five patients with a 3;21 translocation. In all cases, AML1 is interrupted after the runt domain, and is translocated to chromosome band 3q26. As a result of the t(3;21), AML1 is consistently fused to two separate genes located at 3q26. The two genes are EAP, which codes for the abundant ribosomal protein L22, and MDS1, which encodes a small polypeptide of unknown function. In one of our patients, a third gene EVI1 is also involved. EAP is the closest to the breakpoint junction with AML1, and EVI1 is the furthest away. The fusion of EAP to AML1 is not in frame, and leads to a protein that is terminated shortly after the fusion junction by introduction of a stop codon. The fusion of AML1 to MDS1 is in frame, and adds 127 codons to the interrupted AML1. Thus, in the five cases that we studied, the 3;21 translocation results in expression of two coexisting chimeric mRNAs which contain the identical runt domain at the 5' region, but differ in the 3' region. In addition, the chimeric transcript AML1/MDS1/EVI1 has also been detected in cells from one patient with the 3;21 translocation as well as in one of our patients. Several genes necessary for myeloid lineage differentiation contain the target sequence for AML1 in their regulatory regions. One of them is the CSF1R gene. We have compared the normal AML1 to AML1/MDS1, AML1/EAP and AML1/MDS1/EVI1 as transcriptional regulators of the CSF1R promoter. Our results indicate that AML1 can activate the promoter, and that the chimeric proteins compete with the normal AML1 and repress expression from the CSF1R promoter. AML1/MDS1 and AML1/EAP affect cell growth and phenotype when expressed in rat fibroblasts. However, the pattern of tumor growth of cells expressing the different chimeric genes in nude mice is different. We show that when either fusion gene is expressed, the cells lose contact inhibition and form foci over the monolayer. In addition, cells expressing AML1/MDS1 grow larger tumors in nude mice, whereas cells expressing only AML1/EAP do not form tumors, and cells expressing both chimeric genes induce tumors of intermediate size. Thus, although both chimeric genes have similar effects in transactivation assays of the CSF1R promoter, they affect cell growth differently in culture and have opposite effects as tumor promoters in vivo. Because of the results obtained with cells expressing one or both genes, we conclude that MDS1 seems to have tumorigenic properties, but that AML1/EAP seems to repress the oncogenic property of AML1/MDS1.

The tissue-specific nuclear matrix protein, NMP-2, is a member of the AML/CBF/PEBP2/runt domain transcription factor family: interactions with the osteocalcin gene promoter

The nuclear matrix protein, NMP-2, was originally identified as an osteoblast-specific DNA-binding complex localized exclusively to the nuclear matrix. NMP-2 was shown to recognize two binding sites, site A (nt-605 to -599) and site B (nt -441 to -435), in the rat bone-specific osteocalcin gene promoter. This study shows that the NMP-2 binding sites A and B as well as a third NMP-2 binding site (nt -135 to -130) constitute a consensus sequence, ATGCTGGT, and represent an AML-1 recognition motif. AML-1 is a member of the AML transcription factor family which is associated with acute myelogenous leukemia and binds to the sequence TGCTGGT via its DNA-binding runt domain. Electrophoretic mobility shift assays reveal that a component of NMP-2 is a member of the AML/PEBP2/runt domain transcription factor family based on cross-competition with AML-1 consensus oligonucleotide. Limited immunoreactivity of NMP-2 with a polyclonal N-terminal AML-1 antibody and inability of the AML-1 partner protein CBF-beta to form complexes with NMP-2 indicate that NMP-2 is not identical to AML-1 but represents a variant AML/PEBP2/runt domain protein. Western and Northern blots reveal the presence of multiple AML-related proteins and AML-1 transcripts in several osseous cell lines. Furthermore, our results indicate that AML family members may selectively partition between nuclear matrix and nonmatrix compartments. Because proteins that contain a runt domain are implicated in tissue-specific transcriptional regulation, our results support the concept that the nuclear matrix mediates osteoblast-specific expression of the osteocalcin gene.

PEBP2/CBF, the murine homolog of the human myeloid AML1 and PEBP2 beta/CBF beta proto-oncoproteins, regulates the murine myeloperoxidase and neutrophil elastase genes in immature myeloid cells

The myeloperoxidase (MPO) and neutrophil elastase genes are expressed specifically in immature myeloid cells. The integrity of a polyomavirus enhancer core sequence, 5'-AACCACA-3', is critical to the activity of the murine MPO proximal enhancer. This element binds two species, myeloid nuclear factors 1 alpha and 1 beta (MyNF1 alpha and -beta), present in 32D cl3 myeloid cell nuclear extracts. The levels of the MyNF1s increase during early 32D cl3 cell granulocytic differentiation. Both MyNF1 alpha and -beta supershift with an antiserum raised by using a peptide derived from the N terminus of polyomavirus enhancer-binding protein 2/core-binding factor (PEBP2/CBF) alpha subunit. The specific peptide inhibits these supershifts. In vitro-translated PEBP2/CBF DNA-binding domain binds the murine MPO PEBP2/CBF site. An alternate PEBP2/CBF consensus site, 5'-GACCGCA-3', but not a simian virus 40 enhancer core sequence, 5'-TTCCACA-3', binds the MyNF1s in vitro and activates a minimal murine MPO-thymidine kinase promoter in vivo. The murine neutrophil elastase gene 100-bp 5'-flanking sequences contain several functional elements, including potential binding sites for PU.1, C/EBP, c-Myb, and PEBP2/CBF. The functional element 5'-GGCCACA-3' located at positions -66 to 72 differs from the PEBP2/CBF consensus (5'-PuACCPuCA-3') only by an A-to-G transition at position 2. This DNA element binds MyNF1 alpha and -beta weakly. The N terminis of two PEBP2/CBF alpha subunit family members, PEBP2 alpha A and PEBP2 alpha B (murine AML1), are nearly identical, and 32D c13 cl3 cells contain both corresponding mRNAs. Since t(8;21), t(3;21), and inv(16), associated with myeloid leukemias, disrupt subunits of PEBP2/CBF, we speculate that the resulting oncoproteins, AML1-ETO, AML1-EAP, AML1-Evi1, and CBF beta-MYH11, inhibit early myeloid differentiation.

The E2F transcription factor is a cellular target for the RB protein

Although it is generally believed that the product of the retinoblastoma susceptibility gene (RB1) is an important regulator of cell proliferation, the biochemical mechanism for its action is unclear. We now show that the RB protein is found in a complex with the E2F transcription factor and that only the under phosphorylated form of RB is in the E2F complex. Moreover, the adenovirus E1A protein can dissociate the E2F-RB complex, dependent on E1A sequence also critical for E1A to bind to RB. These sequences are also critical for E1A to immortalize primary cell cultures and to transform in conjunction with other oncogenes. Taken together, these results suggest that the interaction of RB with E2F is an important event in the control of cellular proliferation and that the dissociation of the complex is part of the mechanism by which E1A inactivates RB function.

Adenovirus E1A-mediated negative control of genes activated during F9 differentiation

The phenotype of a differentiated cell results from the expression of a unique set of genes in that cell. The differentiation of F9 teratocarcinoma cells in response to retinoic acid and cyclic AMP is an excellent example of this process, as the appearance of several gene products during the course of the differentiation process has been documented. In principle, the activation of gene expression could be due to the appearance of positive-acting factors, the loss of negative-acting factors, or a combination of both. Since F9 cells have been shown to express a cellular E1A analog whereas differentiated F9 cells do not, and it is known that the viral E1A gene exerts a negative effect on transcription of both viral and cellular genes, we determined whether the cellular genes activated during F9 cell differentiation are subject to E1A negative control. We found that infection of differentiated F9 cells with wild-type adenovirus resulted in a decline in the levels of collagen type IV mRNA and plasminogen activator mRNA, both of which are induced by differentiation. At least for the collagen gene, this phenomenon appears to involve a transcriptional repression.