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Biomedical subjects

G Graziani

Publications and source records attributed to G Graziani.

At least 199 records · Page 11Linked to original sources

Effect of 5-fluorouracil on carcinoembryonic antigen expression and shedding at clonal level in colon cancer cells.

BACKGROUND: The carcinoembryonic antigen (CEA) is a tumor marker largely utilized for the detection of minimal disease or as a target of immunotherapeutic approaches. In preclinical models CEA has been found to be up-regulated after exposure of cancer cells to 5-fluorouracil (5-FU). In the present study, the clonal distribution of CEA and its regulation by 5-FU at clonal level was investigated using human HT-29 colon cancer cells. MATERIALS AND METHODS: The extent of CEA expression was measured in terms of: (a) antigen levels on plasma membrane, by flow cytometry; (b) cytoplasm and membrane protein, by Western blot analysis: (c) transcript, by Northern blot analysis; (d) CEA shedding by radioimmunossay. RESULTS: CEA protein and gene transcript were variably expressed among different clones. In all cases 5-FU was able to increase the percentage of CEA-positive cells, the amount of antigen, either in the membrane or cytosolic fractions, and the corresponding transcript. Moreover, a marked increase of CEA shedding was found in drug-treated cells with respect to that of controls. The increase of CEA induced by the antimetabolite was not the result of a selection mechanism based on preferential killing of CEA negative cells. The antimetabolite was capable of enhancing antigen expression also in other CEA-positive tumor cell lines with different basal levels of the marker. CONCLUSIONS: The present findings could be of potential value to increase the sensitivity of diagnostic procedures based on detection of CEA positive tumor cells. Moreover, the antimetabolite might be included in immunotherapeutic protocols to facilitate recognition of CEA-positive cancer cells by immune responses.

Antimetabolites, Antineoplastic↗

[Sepsis, acute renal failure and multiple organ dysfunction syndrome].

The so-called systemic inflammatory response syndrome (SIRS ) represents the cellular inflammatory and neuroendocrine systemic reaction in response to many adverse events. epsis is defined as IR induced by bacterial, mycotic or viral toxins. The circulating toxins deriving from the bacterial wall can activate the septic cascade that induces many systemic reactions involving the activation of the cellular immunity, complement and coagulation system. The endothelial cell is the target of the systemic phlogistic reaction; its stimulation is followed by the production of many vasoactive paracrine and systemic agents. In this context, local and systemic cytokine production plays a major role in inducing the septic cascade, which although meant to be a phlogistic defense reaction, can often become an uncontrolled and dangerous inflammatory reaction. The sepsis-derived lesions can involve many organs and apparatus leading to the picture of sepsis syndrome. Sepsis syndrome often induces severe pulmonary lesions with a picture of acute respiratory distress syndrome (ARDS ). The combination of acute renal failure and sepsis is associated with a high mortality rate, namely in patients with a nitric oxide-induced systemic reduction in peripheral vascular resistances and septic shock. The toxinemia can also induce myocardial damage with a reduction in cardiac performance. Therefore, septic patients who have a combination of pulmonary, cardio-vascular, renal and cerebral lesions present with the picture of multiple organ dysfunction syndrome, that can increase mor-tality to > 0%.

Acute Kidney Injury↗

[Polymyxin-B direct hemoperfusion (PMX-DHP) in gram negative sepsis].

UNLABELLED: Severe sepsis and septic shock have a mortality rate that may range between 28 and 50%. It is estimated that approximately 200,000 patients die per annum in the USA as a consequence of sepsis. The reduction of plasma endotoxin levels to achieve a favourable outcome for septic patients has been previously demonstrated but the effectiveness of treatments targeting single inflammatory mediators during established sepsis has been disappointing. Furthermore,some clinical study clinically showed valuable reduction in cytokine levels by hemofiltration alone. The prompt removal of endotoxins could be an effective way to reduce the immunological activation and the amount of NO produced by endotoxin-activated inducible NO-synthase in many tissues and cells. The polymyxin B cartridge is an extracorporeal hemoperfusion device (PMX-DHP) known to remove circulating endotoxins. Open-label clinical trials testing PMX-DHP have demonstrated its safety in the septic shock treatment while the overall survival rate significantly improved in comparison with the control groups. The purpose of this study was to investigate the effects of PMX-DHP on redox status, inflammatory cytokine profile, monocytes and PMN leukocyte activation in Gram-negative sepsis. Prospective study: six patients, 2 males and 4 females 60.5+/-24.5 years old, in ICU for severe Gram-negative sepsis (emergency surgery for intra abdominal infection). Two PMX-DHP runs, at T0 and T1; 2 hours each; the first within 24 hours from sepsis diagnosis or 12 hours after emergency surgery, the first PMX-DHP at T0, the second after 24 hours.; APACHE II score at T0: 20.1+/-3.7; SOFA score 14.2+/-2.5; organ failure: 3+/-1.5; norepinephrine(Ne) in 1 patient; Ne + dopamine (DA) in 4 patients; DA in 1 patient only. Mean dosage: Ne 0.24 mcg/kg/min; DA 8.9 mcg/kg/min. Four patients in CRRT (continuous veno-venous hemofiltration, AN69 hemofilter) for the entire length of the study. QB 100+/-10 ml/min. Pre and post PMX-DHP, plasma endotoxins as well as anti-IL 1-beta, IL2, IL4, IL5, IL6, IL8, IL10, TNF-alpha, GM-CSF, IFN-gamma levels were measured. Expression of CD64 on monocytes and PMN leukocytes and I -2r CD25 on CD4+ T cells by flow cytometry. Total and reduced plasma cysteine, homocysteine, glutathione (GSH); plasma glutathione peroxidase (GSH-Px) and reductase (GSH-Rx); erythrocyte GSH (eGSH), eGSH-Px and eGSH-Rx; NADP and NADPH and their ratio assessed pre and post PMX-DHP, all compared with 15 age and gender-matched healthy subjects for complete REDOX characterization. RESULTS: We observed a significant reduction of endotoxin levels post PMX-DHP; CD64 monocytes and PMN leukocytes overexpression returned to normal; pro-inflammatory cytokines Il6, Il 10 and TNF-alpha were significantly reduced. We detected no differences in plasma levels of anti-IL 1-beta, IL2, IL4, IL5, IL8, GM-CSF, IFN-gamma pre versus post PMX-DHP. SOFA score from 14.2+/-2.5 to 8.9+/-2.1 post PMX-DHP runs. Four out of six patients survived and were discharged; mortality was 33% versus the anticipated 51%. CONCLUSION: PMX-DHP reduces circulating endotoxins, down-activates monocytes and PMN leukocytes, reduces pro-Inflammatory cytokines and corrects the redox environment imbalance preventing oxidative damage to endothelial cells and the metabolic and functional microvascular derangements that usually lead to multi-organ failure and septic shock.

Adult↗