Biomedical subjects

S Jaramillo

Publications and source records attributed to S Jaramillo.

16 recordsLinked to original sources

PubMed1998

Synergistic transcriptional activation of the mouse urokinase plasminogen activator (uPA) gene and of its enhancer activator protein 1 (AP1) site by cAMP and retinoic acid.

We have investigated the mechanism whereby all-trans retinoic acid (tRA) potentiates the 8-bromo-cAMP (8-BrcAMP)-dependent transcription of the urokinase plasminogen activator (uPA) gene in SC115 mouse mammary carcinoma cells. Photoaffinity labelling experiments showed that tRA did not alter the cellular content of cAMP-dependent protein kinase regulatory subunits I and II. In agreement with this, nuclear run-on analysis in the presence of the translational inhibitor puromycin demonstrated that the effect of 8-BrcAMP and its potentiation by tRA were independent of protein synthesis. A transiently transfected 6.6 kb uPA 5'-flanking region-chloramphenicol acetyltransferase (CAT) fusion gene mimicked the response of the endogenous uPA gene. Thus 1 mM 8-BrcAMP induced a 100-200% increase in CAT content, 100 nM tRA had no effect and 100 nM tRA+1 mM 8-BrcAMP induced a 300-500% increase in cells co-transfected with tRA receptor and/or 9-cis-RA receptor. Analysis of 5'-deleted constructs showed that the tRA effect required at least two cis regions: -2657 to -2186, encompassing the 100 bp uPA enhancer, and -709 to -324, which exhibited silencing activity. Neither region contained a tRA-response element-like motif. Because tRA receptor and 9-cis-RA receptor interact with activator protein 1 (AP1), we tested whether tRA regulated the uPA enhancer AP1 site in the presence of 8-BrcAMP. We found that a dimer of this site fused to a minimal uPA-CAT fusion gene was responsive to 1 mM 8-BrcAMP (100% CAT increase), not responsive to 100 nM tRA, and synergistically responsive to 100 nM tRA+1 mM 8-BrcAMP (240% CAT increase) in cells co-transfected with Fos and Jun. Synergistic activation of the same construct and of the 6.6 kb uPA-CAT fusion gene was also obtained using tRA and 100 nM PMA. We conclude that multiple cis elements, probably including the uPA enhancer AP1 site, mediate the tRA potentiation of uPA transcription.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1997

Distribution of capsular types and antimicrobial susceptibility of invasive isolates of Streptococcus pneumoniae in Colombian children. Pneumococcal Study Group in Colombia.

Streptococcus pneumoniae is the leading bacterial cause of childhood pneumonia in the developing world. This study describes the type distribution and antimicrobial susceptibility of invasive pneumococcal isolates from Colombian children and is part of the Sistema Regional de Vacunas (SIREVA), a PAHO regional initiative designed to determine the ideal serotype composition of a protein polysaccharide pneumococcal conjugate vaccine for use in children less than 5 years old in Latin America. In Colombia, during the study period, centres in Bogota, Medellin, and Cali collected 324 S. pneumoniae isolates from invasive diseases, 238 (73.5%) from children under the age of 2. Pneumonia was the clinical diagnosis in 41.3% cases, meningitis in 41%, and sepsis in 11.2%. The seven most frequent types included 14(21.9%), 5(10.5%), 23F(9.6%), 1(9%), 6B(9%), 19F(7.1%), and 6A(6.2%). The frequency of diminished susceptibility to penicillin (DSP) was 12%, with 8.9% of isolates showing intermediate level resistance and 3.1% showing high level resistance. Among DSP isolates, 23% were also resistant to cefotaxime, 33.3% to erythromycin, 48.7% to chloramphenicol, and 74.3% to trimethoprim/sulfamethoxazole. Multiple resistance was detected in 59% of the isolates that have DSP. Penicillin resistance was associated with types 23F (53.8%) and 14 (25.6%). These data provides information on capsular types prevalent in Colombia that will not only allow the formulation of an ideal vaccine for the region but also reinforce the need for ongoing regional surveillance.

Anti-Bacterial Agents↗

PubMed1992

Redundant regulation of urokinase plasminogen activator transcription by the two major isozymes of cAMP-dependent protein kinase.

The regulation of urokinase plasminogen activator (uPA) gene expression by the two major cAMP-dependent protein kinase isozymes was studied in SC115 mouse mammary carcinoma cells using the site-selective cAMP analog approach. SC115 cells expressed both type I and type II cAMP-dependent protein kinase holoenzyme (at a ratio of 2:3), and selective, partial activation of each holoenzyme could be demonstrated in vitro using appropriate combinations of cAMP analogs. When cells were exposed to the same analog combinations, uPA expression was upregulated 2- to 4-fold when either holoenzyme I or holoenzyme II was targeted. For comparison, a high concentration (1 mM) of 8-bromo-cAMP, an analog that does not discriminate between kinase isoforms, up-regulated uPA 10-fold. These findings suggest that there are two pathways of cAMP-dependent regulation of uPA, one mediated by holoenzyme I, the other by holoenzyme II, and that the end result of activation of each pathway is the same. Differences in the mechanism whereby each pathway regulates uPA were searched for but not found. Both pathways were shown to be dependent on catalytically active enzyme, to be potentiated by retinoic acid treatment, and to regulate uPA transcriptionally. The most likely interpretation of these findings is that uPA transcription is mediated solely by the action of the common catalytic subunit, regardless of whether it originated from holoenzyme I or holoenzyme II.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed1987

Circulating immune complexes in cancer patients.

Circulating Immune Complexes (CIC) have been described in malignant diseases. To elucidate their potential clinical significance, CIC of seventy-eight patients with cancer and of seventy-one normal individuals were studied. Total protein and immunoglobulin composition of CIC were quantitatively measured. Patients sera had consistently higher titers of CIC than normal individuals. Sodium Dodecyl Sulfate/Polyacrylamide Gel Electrophoresis (SDS/PAGE) showed subtle differences in the CIC protein composition between patients and normal individuals.

Adult↗

PubMed1986

Immunoglobulins (Ig) in circulating immune complexes (CIC) in cancer and inflammatory bowel disease (IBD).

Chronically inflamed tissues and most malignancies have antigenic properties. Patients with long-standing inflammatory bowel disease (IBD) are prone to development of colorectal cancer, which is known to shed antigens in the bloodstream. In an effort to study immunological aspects of these diseases, sera from patients with IBD and colorectal cancer were evaluated for presence of circulating antigen-antibody immune complexes (CIC), and compared to normal controls. CIC were precipitated by polyethylene glycol (PEG) and found to be elevated in all diseased groups. Dissociation of CIC and quantification of their antibody component revealed significant elevation of each immunoglobulin in IBD and in patients with colorectal cancer versus control: IgG = 1.776 +/- 1.573 vs 0.734 +/- 0.618 (P less than 0.001); IgA = 0.368 +/- 0.452 vs 0.090 +/- 0.198 (P less than 0.001); IgM = 0.434 +/- 0.235 vs 0.080 +/- 0.285 (P less than 0.001) serum total Ig levels were consistently much higher than CIC Ig. No correlation was found between the individual serum Ig components and the precipitable complexes-bound Ig, suggesting a selective recognition of antigenic components in the CIC, rather than non-specific association and subsequent precipitation of serum Ig. CIC may represent an easily accessible source of immunological determinants for the study of malignant and chronic inflammatory diseases.

Adolescent↗

PubMed1985

Tetraphocomelia in the syndrome of thrombocytopenia with absent radii (TAR syndrome).

We report on an infant with the syndrome of Thrombocytopenia with Absent Radii (TAR) with severe lower-limb involvement. Amegakaryocytic thrombocytopenia was detected at 6 days when the platelet count was 11,000/microL. The platelet count increased steadily to 100,000/microL at 3 years. The patient required bilateral above-knee amputations for femorotibial synostoses. We recommend postponement of all elective operations until platelet counts are normal.

Abnormalities, Multiple↗

PubMed1985

Dietary sodium deficiency potentiates the effect of prostaglandin E2 on in vitro renin release in the rat.

Using a renal cortical slice system from sodium loaded (SL) or sodium deficient (SD) rats, this study investigated whether the effect of prostaglandin E2 (PGE2) on renin release (RR) is mediated by tissue cyclic AMP content (TcAMPc) changes, and if it can be modified by dietary sodium manipulation. At 10(-5) M, PGE2 significantly stimulated RR and TcAMPc in both SL and SD groups of slices. PGE2 doses of 10(-9) M and 10(-7) M were ineffective, although RR, but not TcAMPc, was significantly greater in the SD group in response to 10(-7) M PGE2 than RR in the SL group. Addition of the phosphodiesterase inhibitor theophylline (10(-4) M) together with the same three PGE2 doses maintained the stimulatory effect of 10(-5)M PGE2 alone on RR and TcAMPc in both groups of slices, and reversed the effect of 10(-7) M PGE2 alone on RR and TcAMPc in the SD group of slices only. Added by itself, theophylline was ineffective. These data indicate that: PGE2 can stimulate RR by a direct effect on the juxtaglomerular cells; the RR responses to PGE2 and theophylline administration are enhanced in the SD state; and the possibility of cAMP mediation of the effect of PGE2 on RR is discussed.

Animals↗

PubMed1981

A microimmunofluorescent assay to detect human granulocyte antigens and antibodies.

Granulocyte antibodies are important in the pathogenesis of neonatal granulocytopenia, in some varieties of idiopathic granulocytopenia, and in transfusion reactions, particularly since the development of leukocyte transfusion therapy for granulocytopenic patients. Previous assays for the detection of granulocyte-specific antigens and antibodies were cumbersome, complex, and unreliable. Thus we have now described a new microimmunofluorescent method to assay human granulocyte antigens and their antibodies. This sensitive and reliable technique allows for the preservation of human granulocyte antigenicity for at least 24 hours. The granulocyte-specific antigens of a Caucasian population, residing in metropolitan New York, were studied by this microimmunofluorescent method. We report the distribution of granulocyte-specific antigens in this population, together with the corresponding gene frequency. This microimmunofluorescent test should improve our understanding of antigenic systems restricted to single cell populations.

Antibodies↗

PubMed1979

Segregation of HLA--D specificities with the HLA--B12 allotype.

In a search for bone marrow donors and HLA-D homozygous cells, MLC family studies were performed. Results of the experiments, in which the Seventh Workshop cells 7W569-KR and 7W568-WE were found, are presented here. Within the KR and the WE families two identified and two non-identified HLA-B12 allotype that both families carry.

Alleles↗

PubMed1977

Typing an unrelated panel with PLT cells: association with DW clusters.

Primed LD typing (PLT) cells prepared in one Laboratory (Madison) were shipped in the frozen state and tested in Tübingen on a separate panel that had been typed with homozygous typing cells. Those PLT cells that had been grouped, on the basis of their reaction with test cells of the Madison panel, as defining an HLA PL antigen showed identical or nearly identical patterns of reactivity with the Tübingen panel. Clear association between certain PL antigens and DW clusters as defined with homozygous typing cells could be demonstrated. Of particular interest may be combinations of certain PLT reactions with D-locus-typed cells, where the primed cells do not react as expected from the target's HLA-D type.

Epitopes↗

PubMed1977

Apparent lack of gene dosage effect in the PLT assay.

In this paper the results of primed lymphocyte typing (PLT) tests are reported which show the response to HLA-D-specific stimulator and to unrelated cells. The aim was to find out the sensitivity of the PLT method for evaluating not only qualitative HLA-D-region differences but also gene dosage effects. In addition, the primed cells were restimulated with cells from HLA-D-homozygous individuals mutually negative with the specific stimulator in the usual 5-day primary mixed lymphocyte culture incubation. No gene dosage effect in PLT experiments could be observed.

Epitopes↗

PubMed1977