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Biomedical subjects

E DeJesus

Publications and source records attributed to E DeJesus.

5 recordsLinked to original sources

Melanoma cell lines from different stages of progression and their biological and molecular analyses.

The biological and molecular characteristics of cell lines from metastatic melanomas have been extensively studied but less is known about cells from the biologically earliest stage of primary melanoma. The overall success rate of establishing permanent cell lines from such lesions is only 10% of that for biologically late primary or metastatic melanomas, although our laboratory now has eight cell lines available. The cells are immortal but show reduced or no proliferation in soft agar and immunodeficient mice when compared with primary melanomas from the biologically advanced vertical growth phase. Metastatic melanoma cell lines from patients with familial melanoma or xeroderma pigmentosum are biologically similar to those from patients with spontaneous melanomas. Irrespective of the malignant stages, deletions and mutations can occur in exons 1-3 of the p16INK4A gene. DNA fingerprinting was then employed to demonstrate the uniqueness of individual cell lines and to confirm the identity of cell lines derived from same patients. These cell lines are an excellent resource to investigate melanoma progression.

Animals↗

Gastrointestinal tract colonization with vancomycin-resistant Enterococcus faecium in an animal model.

Vancomycin-resistant enterococci have become important nosocomial pathogens in many institutions. The gastrointestinal tract of susceptible hosts serves as the likely reservoir from which the organism is disseminated. To study factors promoting colonization and the efficacy of decontamination therapy with antimicrobial agents, a model of gastrointestinal colonization with vancomycin-resistant Enterococcus faecium was developed in CF1 mice. At baseline, all animals were colonized with non-vancomycin-resistant enterococci (5.0 log10 CFU/g), but vancomycin-resistant organisms were not detectable. Following gastric inoculation with 5 x 10(8) CFU of a clinical isolate of vancomycin-resistant E. faecium, the strain transiently colonized the gastrointestinal tract of 100% of mice but was undetectable by Day 14 (< or = 2.7 log10 mean CFU/g). In animals who received 5 mg of streptomycin per ml or 250 micrograms of vancomycin per ml in drinking water, colonization with the organism occurred at significantly higher bacterial counts than in controls at 7 days following inoculation (9.4 for vancomycin, 9.2 for streptomycin, and 5.1 log10 mean CFU/g for controls; P < 0.05). Fecal concentrations of vancomycin-resistant E. faecium persisted at high counts through Day 22 in mice receiving these antibiotics, but low counts were also still detected in 3 of 10 control animals. In mice with previously established vancomycin-resistant E. faecium colonization, oral administration of ramoplanin, a lipoglycodepsipeptide to which the strain was susceptible, suppressed growth of all enterococci in feces, including the vancomycin-resistant strain after 7 days of therapy (< or = 3.1 and < or = 3.3 log10 mean CFU/g for vancomycin and streptomycin groups, respectively). All mice had a recurrence of colonization with vancomycin-resistant E. faecium after the ramoplanin was discontinued. In summary, this animal model demonstrates the importance of antibiotics in predisposing to gastrointestinal colonization with vancomycin-resistant Enterococcus spp. Although treatment with ramoplanin temporarily suppressed the organism, recurrence of colonization due to relapse or reinfection occurred.

Administration, Oral↗

Repression of rearranged mu gene and translocated c-myc in mouse 3T3 cells X Burkitt lymphoma cell hybrids.

The productively rearranged immunoglobulin mu chain gene and the translocated cellular oncogene c-myc are transcribed at high levels both in human Burkitt lymphoma cells carrying the t(8;14) chromosome translocation and in mouse plasmacytoma X Burkitt lymphoma cell hybrids. In the experiments reported here these genes were found to be repressed in mouse 3T3 fibroblast X Burkitt lymphoma cell hybrids. Such repression probably occurs at the transcriptional level since no human mu- and c-myc messenger RNA's are detectable in hybrid clones carrying the corresponding genes. It is therefore concluded that the ability to express these genes requires a differential B cell environment. The results suggest that the 3T3 cell assay may not be suitable to detect oncogenes directly involved in human B cell oncogenesis, since 3T3 cells apparently are incapable of transcribing an oncogene that is highly active in malignant B cells with specific chromosomal translocations.

Animals↗

Portrait of a pusher--"mother".

The authors describe a case history of a drug pusher who has represented a special problem for their drug treatment program, since he functions symbiotically with this program, and is intimately involved with its clientele. Such a development, in the course of a drug treatment program, has implications for the practicality of the treatment approach. Methods of coping are discussed.

Adult↗

Developmental issues in deaf children.

This article presents an overview of the development of deaf children. The central difficulty for these children is acquiring language; however, delays in language development are not inevitable. Deaf children of deaf parents are less likely to experience problems in this and other areas of development than are deaf children of hearing parents, although this latter group represents 90% of the population of deaf children. Much more needs to be known about the development of deaf children and the environmental strategies that maximize the development of children with a major sensory deficit. The implications for caregiving to deaf children and their families are discussed.

Child↗