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S Escobar

Publications and source records attributed to S Escobar.

8 recordsLinked to original sources
PubMed1995

Structural analysis of human and murine flt3 ligand genomic loci.

Both the murine and human genomic loci that encode flt3 ligand have been cloned. flt3 ligand is a hematopoietic growth factor that stimulates the proliferation of stem and progenitor cells. The portions of the murine and human flt3 ligand genomic loci encompassing the coding region of the protein are approximately 4.0 kb and 5.9 kb, respectively. The human genomic locus is larger as a result of the presence of repeated sequences within introns I, II, IV, V and VI. The transmembrane isoform of the murine and human flt3 ligand proteins are each encoded within seven exons (1-5 + 7 and 8). Analyses of flt3 ligand cDNA clones show that alternative splicing of a putative sixth exon results in the generation of a soluble form of the flt3 ligand protein. The sizes of each of the exons are well conserved between species. Murine and human flt3 genomic loci have a similar exon: intron structure compared to the genomic loci encoding Steel factor and colony stimulating factor 1. These proteins, which appear to be ancestrally related, are hematopoietic growth factors that stimulate cells via specific and structurally related tyrosine kinase receptors on the cell surface.

Alternative Splicing↗
PubMed1995

Expression of the flt3 receptor and its ligand on hematopoietic cells.

Expression of the flt3 tyrosine kinase receptor and its ligand were examined on various murine and human hematopoietic cell lines. Surface expression of flt3 receptor and flt3 ligand were detected by flow cytometry using biotinylated human flt3 ligand or biotinylated soluble human flt3 receptor Fc fusion protein (flt3R-Fc), respectively. Flt3 receptor and ligand expression were also examined by Northern blot analysis. Flt3 receptor was expressed on the surface of only two of nine murine cell lines and nine of 15 human cell lines, with positive cells representing the B cell, early myeloid, and monocytic lineages. Staining for surface expression of the flt3 ligand revealed that seven of nine murine cell lines and nine of 15 human cell lines screened were positive by flow cytometry. All murine and human cell lines assayed were positive for flt3 ligand RNA expression by Northern blot analysis, but not all cell lines expressing flt3 ligand mRNA had detectable surface expression. Cells expressing the flt3 ligand were of the myeloid, B cell and T cell lineages at various stages of differentiation. Only the OCI-AML-5, NALM-6, and AML-193 cell lines coexpressed both surface flt3 receptor and ligand. The myeloid leukemic M1 cell terminally differentiate into macrophage-like cells under the influence of leukemia inhibitory factor (LIF). We found that LIF-stimulated M1 cells down-regulated surface expression and mRNA levels of the flt3 receptor, but up-regulated expression of the flt3 ligand. Although we could demonstrate that the flt3 receptor was functional in the M1 cell line, flt3 ligand could not induce the M1 cells to differentiate.

Animals↗
PubMed1970

Intestinal absorption of calcium-47 after treatment with oral oestrogen-gestogens in senile osteoporosis.

Intestinal absorption of radiocalcium was measured in 15 postmenopausal women with osteoporosis before and after six months' treatment with an oral oestrogen-gestogen combination. Comparison with a control group indicated a significant improvement in intestinal absorption after treatment. Though there is no evidence that oestrogens have an anabolic effect on human bone, these results indicate that they affect the intestinal absorption of calcium directly.

Aged↗
PubMedDate not supplied

[Total gastrectomy in newborn infant].

Total gastrectomy is rarely indicated in childhood and when necessary it involves multiple ulterior therapeutic problems, mainly nutritional, which need a meticulous physiological approach to avoid further complications, as illustrated by the following patient who, at age 15 months, was submitted to total gastric resection, Y en Roux esophagojejunal anastomosis and splenectomy, because of peritonitis secondary to dehiscence of a recent esophagogastric anastomosis for partial gastric resection due to gastric volvulus and necrosis, which in turn were associated to diaphragmatic relaxation. The patient was admitted to our hospital one month later with signs of acute calorie-protein malnutrition (W/A 60% and W/H 68%, NCHS standards) requiring combined parenteral and enteral nutritional support (via central venous catheter and jejunostomy tube for 15 and 35 days respectively) together with intramuscular vitamin B 12, oral iron and oral vitamin supplements before it became possible to fed him only by mouth. Prophylaxis against Streptococcus pneumonia infections with monthly benzatin penicillin was also instituted. Mean daily weight increases of 16 g, W/A 68% and W/H 74% were thus achieved before hospital discharge, without evidence of dumping syndrome nor alkaline reflux.

Gastrectomy↗
PubMedDate not supplied

[Modular diet and parenteral support in persistent diarrhea].

Eleven infants with protracted diarrhea were treated with modular diet and short-term parenteral nutrition. Mean age at admission was 3.7 months with males predominating. Enteropathogenic E. coli, classic serotypes, were isolated from 7 patients and rotavirus from one. A child with combined, severe immunodeficiency died. Milk protein intolerance was diagnosed in another patient. Balance studies and peroral biopsies were performed. Malnutrition was more frequent and hospital stay was longer in those infants who developed nosocomial infections. Even though this treatment shortened the duration of the hospitalization, the negative nutritional impact persisted: Weight/Age (NCHS) decreased from 84% to 61%, with rapid recovery after discharge. Fecal lactic acid excretion was increased on admission to 1,296 mg x day and disaccharidase activity was decreased. The modular diet decreased both fecal volume and lactic acid excretion.

Diarrhea, Infantile↗
PubMedDate not supplied

[Refractory diarrhea].

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Diarrhea, Infantile↗
PubMedDate not supplied

[The modular diet].

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Diarrhea, Infantile↗