Induction of amyloid and associated pathological changes induced by alveolar hydatid cysts (AHC), the larval stage of Echinococcus multilocularis, were studied in Balb/c, C57BL/6J, CBA and A/JAX strains of mice. The onset and incidence of amyloidosis in these four strains corresponded with the intensity of hepatic inflammation and not with the load of parasite biomass. The spleens of AHC-infected mice were more sensitive to amyloid deposition than livers or kidneys. Rabbit antisera raised against mouse AA-amyloid protein (Azocasein induced) was shown to cross-react with AHC-induced amyloid (AHCA). The immunological cross-reactivity was determined by three different assays: immunoperoxidase, indirect immunofluorescence and Ouchterlony tests. In order to determine the chemical nature of AHCA, it was extracted from the tissues of C57BL/6J mice at 12 weeks p.i., either in water or 6 M acid-urea buffer. The AHCA protein showed a molecular weight (Mw) of 8,000 daltons and a pI value of 5.3. Azocasein-induced and purified amyloid protein from C57BL/6J mice had a similar MW but a pI value of 5.8. The amino acid composition of purified AHCA presented a closer relationship of AHCA to senescence-induced (age associated) amyloid protein than to AA-amyloid. The role of AHC-derived factors in the pathogenesis of secondary amyloidosis was studied in vitro and in vivo. AHC-antigens were purified by affinity chromatography and by gel filtration on Sephacryl S-300. Purified AHC-antigens were cytotoxic and chemotactic when tested in vivo and phlogistic when introduced intradermally or intraperitoneally in mice. Furthermore, AHC-antigens were amyloidogenic. The injection of 1 mg i.p. in mice induced amyloid deposition after 96 hours in their spleens. In Balb/c, C57BL/6J and A/JAX mice, amyloid deposition was correlated with the appearance of an amyloid enhancing-like factor (AHC-AEF) in the spleens. AHC-AEF appeared just prior to amyloid deposition. The passive transfer of AHC-AEF t

Considerable evidence suggests that insulin-dependent diabetes mellitus (IDDM) is a T cell-mediated autoimmune process that is directed against antigenic target(s) on pancreatic $ beta$ cells. To better understand T cell involvement in the pathogenesis of IDDM, a panel of T cell hybridomas were produced from pancreas-derived T cells of spontaneously diabetic NOD mice. A total of 119 hybridomas were constructed from 8 fusions and 94 of these were tested. Twelve hybridomas were found to be islet-reactive since they produced high level of interleukin-2 (IL-2) in the presence of NOD islet cells and NOD antigen-presenting cells (APC's). The responses could also be detected against islet cells of other strains (i.e. C3H/Hej or C57B1/6), but only in the presence of the NOD APC's. Phenotyping of these islet-reactive hybridomas showed that all of them were CD3$ sp{+}$CD4$ sp{+}$. Furthermore, a high frequency (39%) of CD4$ sp{+}$ T hybridomas in the panel were found to be islet reactive. In addition, analysis of T-cell receptor (TCR) V$ sb{ beta}$ expression of these islet-reactive T-cell hybridomas revealed that TCR V$ sb{ beta}$ element usage is heterogeneous unlike findings in some experimentally induced autoimmune diseases.

BB rats spontaneously develop an insulin-dependent diabetes mellitus strikingly similar to the syndrome observed in man. The disorder requires the presence of multiple susceptibility genes and unknown environmental factors. At least one susceptibility gene resides within the u haplotype of the rat major histocompatibility complex (RT1). Restriction fragment length polymorphism analysis of genomic DNA from rats generated from a series of intercrosses between diabetic BB rats and Buffalo rats (RT1$ sp{ rm b})$ demonstrated that animals heterozygous throughout the RT1 developed IDDM. A single dose of the high risk allele was thus shown to be sufficient for the development of IDDM if other susceptibility factors are present. RFLP analysis of DNA from rats generated in three other breeding studies involving the r8 and r4 recombinant haplotypes mapped the IDDM susceptibility genes between the RT1.A and RT1.C loci, the immune response region. As the u regions of the various haplotypes used in these studies were not derived from the BB rat, the development of IDDM in the progeny strongly suggested that the MHC requirement for IDDM is only for a "u" allele and not a particular or "diabetogenic" u allele. / Analysis of the expression of MHC genes in isolated islets of age-matched BB and Wistar-Furth rats demonstrated enhanced class I MHC gene expression in the islets of prediabetic BB rats. Immunohistochemical analysis confirmed that enhanced class I expression was an early event during the pathogenesis of IDDM, and did not detect aberrant expression of class II antigen on beta cells. Investigation of the inducibility of class I and II MHC genes on the rat insulinoma cell line RIN5F by crude lymphokine preparations or recombinant gamma-interferon indicated that although both classes of genes were inducible, their kinetics of induction are quite different. In vitro nuclear transcriptions demonstrated that induction of the genes had a transcriptional basis. Although class II genes were induced by gamma-interferon, class II antigen was not detected by flow cytometric analysis.

In this thesis, composed of two separate articles, we studied the frequency of COPD exacerbations and assessed the effectiveness of inhaled corticosteroids in preventing a first exacerbation of COPD. We used an inception cohort of COPD patients, formed from the computerised databases of Saskatchewan. / The rate of COPD exacerbations was 11.5 per 100 person-years. It increased with age and was 50% higher in men than women. Use of inhaled corticosteroids in the year prior to the index date and current use were associated with a small increase in the risk of a first exacerbation (adjusted RR = 1.27, 95% CI: 1.08--1.48 and 1.51, 95% CI: 1.22--2.87, respectively). The risk increased with increasing daily dose (adjusted RR per 1000 mug = 1.83, 95% CI: 1.47--2.28). / We did not find that the use of inhaled corticosteroids reduces the risk of a first exacerbation in patients with COPD.

The accumulation of eosinophils at sites of inflammation is one of the hallmarks of asthma. The aim of the present study was to investigate the involvement of PGD2 and the DP1 and DP2 receptors in eosinophil recruitment in vivo. In this project, a group of Brown Norway rats were administered intratracheally with PGD2, which activates both DP1 and DP2 receptors, as well as selective agonists of DP1 (BW245C) and DP2 (15R-methyl-PGD 2 and 13,14-dihydro-15-oxo-PGD2) receptors. In addition, we have also tested the effect of 15-deoxy-Delta12,14-PGJ 2 which known to activate PPARgamma and NF-kappaB, and DP2 receptors. Negative control animals received saline alone while positive control animals received 5-oxo-ETE. In this work, we have shown for the first time that PGD2 and selective DP2 receptor agonists induce pulmonary eosinophilia in vivo in the following order of potency; (15R-methyl-PGD 2 > PGD2 ≈ 15-deoxy-Delta12,14-PGJ 2 > dhk-PGD2). This effect was time dependent with the maximal response being observed after 24 h. Interestingly; this response was somehow diminished when higher dose was tested (10mug). This effect is most likely to be mediated solely through the DP2 receptor since this effect was not shared by the DP1 specific agonist BW245C. These results are consistent with an important role for PGD2 and the DP 2 receptor/CRTH2 in allergic diseases such as asthma and suggest that this receptor may be an important therapeutic target for these conditions.

The objective of this study was to identify subgroups in patients with Alzheimer's Disease (AD), based on a dissociation in their performance on visuospatial tasks: one subgroup with predominant impairment on object recognition or the "What" system, and another subgroup with predominant impairment in spatial recognition or the "Where" system. Also, an attempt was made to clarify the relationship between attention on these two visuospatial processes. Amongst twenty-four patients with AD, we identified two pairs of patients with dissociated performances. However, except for one case, the dissociations found were mainly based on the prominent impairment of the spatial ability or the "Where" system. Based on the performance of cohort, our results suggested that spatial abilities are more impaired than the object recognition ability. In addition the results showed that AD also affects the central executive system, and that the impairments in visuospatial processes, especially the "What" system, may at least partly be explained by deficits in this system. These findings also indicate that certain sub-components of visuospatial processes can be distinctively affected by AD.

Chronic myelogenous leukemia (CML) is a neoplastic disorder of pluripotent hematopoietic stem cells which follows a biphasic clinical course consisting initially of a relatively benign chronic phase followed by progression to a fatal acute leukemia (CML blast crisis). A clonal cytogenetic abnormality (i.e. the Philadelphia or Ph chromosome), resulting from the reciprocal translocation t(9;22)(q34;q11), is found in over 95% of patients. A hybrid gene is created at the breakpoint of Ph, derived from the ABL proto-oncogene (9q34) and from the BCR gene (22q11), which results in the expression of a 210 KDa fusion protein tyrosine kinase called P210BCR/ABL (P210). Expression of P210 alone is generally believed to be sufficient to induce chronic phase CML but, the deregulation of additional genes appears to be required for progression to CML blast crisis, as inferred by the presence of secondary cytogenetic abnormalities in over 80% of patients. To investigate the potential significance of P210 expression in the induction of genetic instability associated with CML progression, I studied cytogenetic changes in a murine cell line (32D) which expressed P210BCR/ABL from a retroviral vector. Using Giemsa-trypsin banding technique, I found a common marker chromosome t(4;12) in 13 subclones, a second new marker t(2;17) in 3/13 subclones and, additional clonal marker chromosomes in all of the subclones examined. Six subclones consisted of two or three karyotypically distinct cell populations. This study demonstrates that BCR/ABL can directly induce both numerical and structural chromosomal abnormalities in hematopoietic cells. This murine cell model may provide a useful tool to further study the causal relationship of cytogenetic instability and cooperative molecular events involved in the initiation and progression of CML.

Heterogeneity is a ubiquitous finding in human tissues. Indeed, the cellular heterogeneity of a tumor may be viewed as a caricature of normal tissue that defines the tissue of tumor origin and prognosis. The heterogeneity of a simple tissue, bladder epithelium, has been studied with quantitative flow cytometry to measure light scattering properties and lectin binding to cells in normal and malignant tissue. It was confirmed that such quantitative assessments could be used to reveal relationships of normal tissue heterogeneity to malignant tissue heterogeneity which were relevant to both normal tissue development and tumor status. In addition, an indicator of DNA replication/cell proliferation (a monoclonal antibody for DNA cruciforms) was studied for future use in normal and tumor tissues to reveal various aspects of that functional heterogeneity. Fundamental methods for quantitative assessment and qualitative distribution of the initiation sites of DNA replication were established and applied to normal and malignant cell lines. Such functional analyses of heterogeneity hold the prospect of identification and characterization of tumor stem cell populations.

Background. Peripheral vein infusion thrombophlebitis (PVIT) is a complication of intravenous therapy. We hypothesized that inherited thrombophilia may increase the risk of PVIT. / Purpose. In preparation for a multi-center study of our hypothesis, we conducted a pilot study to estimate PVIT incidence, measure the prevalence of inherited thrombophilia, and pilot test the study procedures. / Methods. A prospective case-control study of 25 cases (patients with PVIT) matched on catheter duration to 25 controls. PVIT risk factors and inherited thrombophilia were assessed. / Results. PVIT incidence was 14 per 1000 catheter-days. There were no significant differences in the prevalence of the inherited thrombophilia disorders among cases and controls (32% vs. 48%). A previous history of PVIT was noted in 4 cases compared to 0 controls. Procedural problems included a high rate of non-consent and inadequate communication with the laboratory. / Conclusions. Though an association between PVIT and inherited thrombophilia was not shown, a previous history of PVIT among cases supports a biological predisposition to PVIT. Our pilot study did provide useful data on PVIT incidence and procedural issues used to design a more definitive study of inherited thrombophilia and PVIT.

IL-12 and IL-13 are recently discovered cytokines which belong to Th1 and Th2 subtypes, respectively. To further support the hypothesis that Th2-type cytokines are involved in asthma, mRNA levels for IL-12 and IL-13 were measured in bronchial biopsies from asthmatics and normal controls as well as in moderately severe asthmatics before and after corticosteroid therapy using the technique of in situ hybridization. The number of IL-13 mRNA positive cells in asthmatics was significantly higher than that found in normal controls. However, there was a significant decrease in the number of IL-12 mRNA positive cells in asthmatic biopsies compared to normal controls. Following corticosteroid therapy, a significant decrease in IL-13 mRNA positive cells and an increase in the number of cells expressing IL-12 mRNA was detected. The results suggest an in vivo role of the cytokines in modulating allergic responses and support the role of Th2 type cytokines in asthma.