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L Riera

Publications and source records attributed to L Riera.

At least 19 recordsLinked to original sources
PubMed1997

Molecular cloning and expression of an interferon-inducible protein encoded by gene 203 from the gene 200 cluster.

We report here the complete coding sequence of a 203 cDNA, a member of the interferon-inducible Ifi 200 gene family. By combining reverse-transcriptase PCR and rapid amplification of cDNA ends (RACE) techniques we have obtained a 3.8-kb cDNA corresponding to a 203 mRNA. When used as a probe in northern analysis, its 3' segment hybridized to a 3.8-kb interferon-inducible mRNA, whereas the 5'-end additionally hybridized to a less abundant interferon-inducible 1.8-kb mRNA. Nucleotide sequence analysis revealed that the two mRNAs share the 5'-untranslated region and the same open reading frame, which encodes a hydrophilic protein composed of 408 amino acids. The difference between them is due to a 3'-untranslated region extended by alternative polyadenylation site selection. Furthermore, 203 mRNA was found to be inducible by interferon-alpha in various murine cell lines. Using polyclonal antibodies raised against a segment specific for the 203 protein, we established that p203 protein levels increase on treatment with interferon-alpha in murine fibroblasts and that p203 is located in the nucleus.

3T3 Cells↗
PubMed1997

Transfer of the interleukin-2 gene into human cancer cells induces specific antitumor recognition and restores the expression of CD3/T-cell receptor associated signal transduction molecules.

Normal peripheral blood mononuclear cells (PBMC) were co-cultured with a human lung cancer cell line (LC89) transduced with the interleukin-2 (IL-2), IL-7, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha) genes to evaluate the capacity of the engineered cells to: allow survival of CD3+ and CD56+ cells, generate cytotoxic effectors with HLA class I restricted and unrestricted antitumor activity, and interfere in the molecular organization of the CD3/T-cell receptor associated signal transduction machinery. When PBMC were cultured up to 3 weeks with IL-2 releasing LC89 cells (LC89/IL-2), the number of viable CD3+ and CD56+ lymphocytes was much greater than in cultures with parental cells or with LC89 cells transduced with the other cytokine genes. After 1 week of coculture, a variable degree of restricted and unrestricted killing directed against different targets was observed. When the cultures were prolonged up to 3 weeks, LC89/IL-2 cells induced a marked increase in specific cytotoxic activity, which was coupled to a further enhancement of unrestricted lytic function. In the presence of LC89/IL-7 cells the degree of specific lysis remained unchanged, whereas unrestricted effectors were markedly decreased. No cytotoxic activity could be induced by LC89/GM-CSF and LC89/TNF-alpha cells in the few lymphocytes surviving after 3 weeks of culture. Coculture of parental LC89 cells with PBMC was consistently associated with a downmodulation in the expression of the CD3 zeta chain, as well as of the tyrosine kinases p56ick and ZAP-70. On the contrary, LC89/IL-2 cells, and not LC89 cells transduced with the IL-7, GM-CSF, or TNF-alpha gene, were capable of reverting the immunosuppressive effect exerted by the tumor cells. This protective effect could be maintained in cultures prolonged up to 4 weeks. When the same cultures were set up in Transwell, ie, with a membrane separation between cancer cells and PBMC, the expression of the CD3 zeta chain and of the p56ick and ZAP-70 tyrosine kinases remained unchanged under all culture conditions, indicating that the downmodulation of T-cell signal transduction molecules requires a direct cell to cell contact. These results show that transfer of the IL-2 gene into the DNA of human cancer cells promotes both restricted and unrestricted antitumor activity, and is capable of restoring and maintaining the expression of molecules involved in the process of T-cell mediated tumor cell recognition, thus underlining the potential role of the IL-2 gene in the design of vaccination protocols with cytokine gene transduced cancer cells.

Adenocarcinoma↗
PubMed1996

Interleukin-8 induces the accumulation of B-cell chronic lymphocytic leukemia cells by prolonging survival in an autocrine fashion.

Several cytokines have been suggested to play a regulatory action on the neoplastic clone of patients with B-cell chronic lymphocytic leukemia (B-CLL) by interfering in the differentiation, proliferation, or death/survival pathways. Interleukin-8 (IL-8) is a chemoattractant protein constitutively expressed at the mRNA level and released by B-CLL cells. In view of the presence of the IL-8 receptor mRNA and of specific IL-8 binding, confirmed also by Scatchard analysis using 125I-IL-8, the study was extended to evaluate the possible regulatory role of this cytokine on B-CLL cells. IL-8 failed to show any in vitro proliferative effect on leukemic B-CLL cells. By contrast, the propidium iodide (PI) staining of the DNA content showed that IL-8 could prolong the survival of resting B-CLL cells in 11 of 16 cases studied. In the remaining 5 cases, 90.6% +/- 4.39% SD of the cells after culture remained viable and IL-8 could exert a significant death protection action after pretreatment with 10(-4) mol/L hydrocortisone, which reduced the percentage of viable B-CLL cells. The dose range of IL-8 capable of inducing the prolonging survival effect is comparable with the levels of IL-8 released constitutively by B-CLL cells, indicating that the death protection action is exerted at physiologic doses. The in vitro rescue from death induced by IL-8 is reflected by an increased expression of bcl-2 mRNA in B-CLL cases incubated in the presence of IL-8. These findings were further confirmed at the protein level, because in B-CLL cells that displayed a bimodal bcl-2 intracytoplasmatic protein expression IL-8 was capable of upmodulating the bcl-2high expression peak. The potential autocrine regulatory action exerted by IL-8 is supported by the evidence that exogenous IL-8 can upregulate IL-8 mRNA in B-CLL cells. These results, together with the demonstration that antibody-mediated neutralization of endogenous IL-8 could induce a significant in vitro reduction in the number of living cells, further support the hypothesis that, in B-CLL, the physiologic doses of IL-8 released constitutively by the leukemic clone may play an autocrine role in the process of cell accumulation characteristic of this disease.

Antigens, CD↗
PubMed1995

Renal angioscopy.

Explore the source record for details and available documents.

Accidents, Traffic↗
PubMed1994

Effect of different preservation solutions on adenine nucleotide content and metabolism in human kidney transplantation.

Differences in purine metabolism produced by three preservation solutions were studied by determining the adenine nucleotide (ATP, ADP, AMP, and IMP) and nucleoside (adenosine, inosine, and hypoxanthine) levels in human kidney cortical biopsies. Forty kidney allografts were studied using University of Wisconsin (UW) solution (n = 20), Euro-Collins (EC) solution (n = 12), and modified EC solution with mannitol (M; n = 8). No significant differences were found between the three solutions studied with regard to ATP, ADP, or AMP changes. The mean ATP level (nmol/mg prot +/- SEM) at the end of preservation in the UW group was 2.7 +/- 0.3 nmol/mg, in the EC group 3.8 +/- 0.7 nmol/mg, and in the M group 2.3 +/- 0.4 nmol/mg. ATP 30 min after reperfusion in the UW, EC, and M groups was 5.7 +/- 0.8 nmol/mg, 6.4 +/- 1.0 nmol/mg, and 4.6 +/- 0.5 nmol/mg, respectively. However, an important difference appeared in the catabolic products determined. Kidneys perfused with UW solution had a significantly higher level of adenosine (2.6 +/- 0.6 nmol/mg), inosine (11.8 +/- 2.2 nmol/mg), and hypoxanthine (18.1 +/- 2.1 nmol/mg) at the end of cold storage than those perfused with EC (0.4 +/- 0.1 nmol/mg, 2.0 +/- 0.8 nmol/mg, and 7.1 +/- 1.4 nmol/mg) and M solutions (0.2 +/- 0.05 nmol/mg, 0.5 +/- 0.1 nmol/mg, and 5.2 +/- 0.6 nmol/mg; P < 0.05). These levels returned to initial values 30 min postreperfusion and there were no differences with the EC or M solution groups at that time.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenine Nucleotides↗
PubMed1994

Cytokine gene therapy in oncology.

Over the last few years the possibility of introducing foreign material into the genome of host cells has become technically feasible. This has opened a new era in the treatment of congenital disorders, but has also offered potential innovative avenues in the management of cancer patients. Here, we shall discuss how cytokine genes may be successfully transduced into the DNA of different experimental tumours and how through this approach the tumorigenicity of the neoplastic cells may be abrogated. Emphasis will be given on the demonstration that following cytokine gene transfer, namely with the interleukin 2 (IL-2) gene, two of the primary goals of an optimal immunotherapeutic approach, i.e. anti-tumour specificity and memory, may be achieved. Attention will be focused, in particular, on the results so far obtained, as well as on ongoing studies, with human tumour cells engineered to release different cytokine genes. The design and activation of the first clinical protocols aimed at treating advanced cancer patients with cytokine gene-transduced neoplastic cells will also be discussed, together with other strategies of genetic engineering currently under investigation.

Animals↗
PubMed1993

Relationship between donor renal interstitial surface and post-transplant function.

Forty-three biopsies were performed between 30 and 60 min after reperfusion. Patients (22 males/21 females, mean age 41 +/- 12 years, mean donor age 32 +/- 14 years) were treated either with antilymphocytic globulin, cyclosporin, and prednisolone (24 cases), or OKT3, cyclosporin, and prednisolone (19 cases). Ten patients had delayed post-transplant renal function (DPRF), defined as haemodialysis requirements after surgery, and seven patients had acute rejection 11 +/- 16 days post-transplant. Kidneys were perfused with a hypertonic solution containing mannitol. All patients were followed up for at least 30 months. During follow-up, five patients lost their grafts due chronic rejection, two patients due to noncompliance and one due to recurrence of focal segmental glomerulosclerosis. One patient died from heart infarction. Biopsies were stained with H&E, Masson's trichrome, periodic acid-Schiff (PAS) and silver methenamine. Interstitial fibrosis, interstitial oedema, tubular vacuolization, and peritubular capillary oedema were measured using a semiquantitative scale. Five 400 x magnification micrographs of cortical interstitium from silver-methenamine-stained sections were used to measure percentage of interstitial surface with a morphometer. Interstitial surface was 18.7 +/- 6.2% (range 3.2-35.3%). A positive correlation was found between interstitial surface and donor age (r = 0.469, P = 0.0015). No relationship was found between warm and cold ischaemia times and tubular vacuolization or peritubular capillary oedema.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[Acquired cystic renal disease associated with renal carcinoma: report of 3 cases].

Presentation of three cases of haemodialysis patients with acquired cystic renal disease (ACRD) who, over the course of their illness, developed clear cells renal carcinoma. The paper emphasizes the common association of these two entities and the need to consider ACRD cases as patients at high risk of developing renal neoplasia.

Adenocarcinoma↗
PubMed1992

[Mannitol solution (M-400) vs. mannitol solution combined with allopurinol in the prevention of post-transfusion acute renal failure].

Evaluation on the incidence of Acute Renal Failure (ARF) from a total of 41 corpse renal graft receptors, 20 of which received perfusion with mannitol solution at 400 mOsm/kg (Group 1) and 21 the same mannitol solution plus allopurinol (Group 2). No significant differences were present between both groups when they were analyzed for ARF incidence (15% vs 23.8%); overall incidence was 19.5%. 24-hour initial diuresis was shown to be an excellent predictor for long-term graft functionality. We can conclude that the addition of mannitol to the perfusion solution contributes decisively to reduce post-transplantation ARF, while addition of allopurinol does not have further beneficial effects.

Acute Kidney Injury↗
PubMed1987

A comparison of the in-vitro activity of seventeen antibiotics against Streptococcus faecalis.

The in-vitro activity of seventeen antibiotics against 177 clinical strains of Streptococcus faecalis was evaluated. Ampicillin and mezlocillin were the most active beta-lactams tested (geometric mean MICs, 0.61 and 0.74 mg/l, respectively). Aminoglycosides showed poor activity and 22.6% of the strains were resistant to 2000 mg/l of streptomycin. No correlation was observed between MICs of gentamicin and streptomycin. Moderate activity was observed when testing norfloxacin and ciprofloxacin. Teicoplanin and co-trimoxazole were extremely active, showing geometric mean MICs of 0.59 and 0.08 mg/l respectively. All strains were susceptible to vancomycin and teicoplanin.

Ampicillin↗
PubMed1985

Detection of Haemophilus influenzae type b antigenuria by Bactigen and Phadebact kits.

Two commercially available reagents, latex particles (Bactigen) and Staphylococcus aureus suspensions (Phadebact), were compared for the detection of the capsular polyribitol phosphate antigen of Haemophilus influenzae type b in 18 pediatric patients with proven infections due to H. influenzae type b. Whereas both tests nearly equally detected the antigen in the first urine specimens from the patients, the latex test remained positive significantly longer than did the Phadebact test for serial urine specimens. We conclude that the Bactigen test is slightly more sensitive than the Phadebact test for detecting urinary H. influenzae type b antigen.

Agglutination Tests↗