Jorge E Ossa

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Genetic linkage studies place a gene causing early onset familial Alzheimer's disease (FAD) on chromosome 14q24.3 (refs 1–4). Five mutations within the S182 (Presenilin 1: PS–1) gene, which maps to this region, have recently been reported in several early onset FAD kindreds5. We have localized the PS-1 gene to a 75 kb region and present the structure of(More)
Various cattle populations in the Americas (known as criollo breeds) have an origin in some of the first livestock introduced to the continent early in the colonial period (16th and 17th centuries). These cattle constitute a potentially important genetic reserve as they are well adapted to local environments and show considerable variation in phenotype. To(More)
Missense mutations in the presenilin 1 (PS1) gene cause the most common form of dominant early–onset familial Alzheimer's disease (FAD)1,2 and are associated with increased levels of amyloid β–peptides (Aβ) ending at residue 42 (Aβ42) in plasma and skin fibroblast media of gene carriers3. Aβ42 aggregates readily and appears to provide a nidus for the(More)
We describe a method for culturing over 90% pure bovine macrophages from peripheral blood mononuclear cells separated with Nycoprep. The cells were cultured for 12 days and then stained with esterase and with anti CD14 to test for purity. The method is reproducible and ensures an adequate number of cells for immunological research. Additionally, we report(More)
Extracts of nine species of plants traditionally used in Colombia for the treatment of a variety of diseases were tested in vitro for their potential antitumor (cytotoxicity) and antiherpetic activity. MTT (Tetrazolium blue) and Neutral Red colorimetric assays were used to evaluate the reduction of viability of cell cultures in presence and absence of the(More)
Endosseous implants have been used as orthodontic anchorage in recent years. A 3-dimensional mathematical model was constructed that uses the finite element method, which simulated an endosseous implant and an upper canine with its periodontal ligament and cortical and cancellous bone. Levels of initial stress were measured during 2 types of canine(More)
Because involuntary hospitalization involves the restricting of an individual's autonomy and choice, the challenge in nursing practice is to listen to the client's perceptions and then to set "limits in a humane and least restrictive manner to assure the safety of the client and others" (American Nurses' Association, 1982). However, the danger is that(More)
Healthy waterfowl were found to be carriers of duck plague (DP) virus. Black ducks (Anas rubripes) and Canada geese (Branta canadensis) surviving a natural outbreak of DP at Coloma, Wisconsin, in 1973 yielded DP virus in cloacal swabs taken four years postinfection. Experimental infection of previously unexposed mallard ducks (Anas platyrhynochos) with the(More)
To demonstrate a possible association between stress factors and the presence of human cytomegalovirus (HCMV) DNA in leukocytes and in cell-free body fluids, at 2-week intervals over a 6-month period, specimens were taken for HCMV DNA testing from 11 healthy CMV-seropositive individuals who were also surveyed for stress-producing events occurring during the(More)
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