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Biomedical subjects

F Tamion

Publications and source records attributed to F Tamion.

27 records · Page 2Linked to original sources
PubMed1998

Nitric oxide synthase inhibition and the induction of cytochrome P-450 affect heme oxygenase-1 messenger RNA expression after partial hepatectomy and acute inflammation in rats.

OBJECTIVES: a) To evaluate in vivo, in rat liver, heme oxygenase-1 (HO-1) messenger RNA (mRNA) expression level and the regulation of 3',5'-cyclic guanosine monophosphate (cGMP) production during hepatic regeneration, localized inflammation, and systemic inflammation; and b) to investigate the effect of the induction of cytochrome P-450 and nitric oxide synthase (NOS) inhibition on HO-1 mRNA level and cGMP production in the liver. DESIGN: Experimental, comparative study. SETTING: Biochemical and molecular biology laboratory. SUBJECTS: Six-wk-old male Sprague-Dawley rats (n = 60). INTERVENTIONS: We randomly divided the rats into four groups: a) saline controls; b) animals receiving lipopolysaccharide (600 microg/kg) for systemic inflammation; c) animals receiving turpentine oil (5 mL/kg) for localized inflammation obtained by sterile abscess; and d) partially hepatectomized animals (two-thirds removal of the parenchyma) for hepatic regeneration. MEASUREMENTS AND MAIN RESULTS: Hepatic regeneration induced HO-1 mRNA expression, as shown by quantitative reverse transcription-polymerase chain reaction analysis. The time course of liver HO-1 mRNA induction after partial hepatectomy and localized and systemic inflammation showed a similar and gradual increase, with a maximum at 6 hrs and a return to a minimal level 48 hrs after treatments. Liver HO-1 mRNA was overexpressed during localized vs. systemic inflammation. This overexpression was not correlated with either serum IL-6 or corticosterone concentrations, but is related to increased cGMP production. The administration of phenobarbital, a cytochrome P-450 inducer and of nitro-L-arginine methyl ester, a NOS inhibitor, prevented cGMP production and abolished the overexpression of HO-1 mRNA. CONCLUSIONS: The results of this study indicate that HO-1 mRNA is induced during hepatic regeneration with a similar time course to that observed during acute inflammation. In addition, we demonstrated that: a) HO-1 mRNA is overexpressed during localized vs. systemic inflammation; b) this overexpression is not correlated with IL-6 or corticosterone concentrations but is related to intrahepatic cGMP production; c) induction of cytochromes P-450 and/or inhibition of NOS both reduce liver cGMP production and HO-1 mRNA expression. These results suggest that in rat liver, a cGMP-transducing pathway may control HO-1 mRNA expression. Thus, there may be a role for HO-1 mRNA in the modulation of the hepatic stress response.

Acute Disease↗
PubMed1997

Gut ischemia and mesenteric synthesis of inflammatory cytokines after hemorrhagic or endotoxic shock.

The intestine plays a major role in the pathophysiology of multiorgan failure. Although the systemic inflammatory response might be induced by endotoxin released through bacterial translocation, other factors such as intestinal ischemia might be implicated. We investigated the relationship between intestinal ischemia-reperfusion and cytokine release in rat models of hemorrhagic or endotoxic shock. Plasma levels of tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), lactate, and endotoxin, as well as macrophage TNF-alpha and IL-6 mRNA expression, were assessed at the end of shock and resuscitation. Hemodynamic changes and lactate levels suggested the presence of intestinal ischemia in both models. Mesenteric levels of TNF-alpha and IL-6 were increased by hemorrhage and further increased after saline resuscitation. Similar results were obtained with mRNA cytokine gene expression in macrophages. Endotoxin was not detectable in the hemorrhagic group. Endotoxic shock also increased production of cytokines, which, in contrast to hemorrhage, was not further increased by resuscitation. These results suggest that intestinal ischemia-reperfusion upon hemorrhage and resuscitation may be a major trigger for cytokine gene expression in the absence of endotoxin.

Animals↗
PubMed1997

Comparative physiologic effects of noninvasive assist-control and pressure support ventilation in acute hypercapnic respiratory failure.

STUDY OBJECTIVE: To compare the effects of noninvasive assist-control ventilation (ACV) and pressure support ventilation (PSV) by nasal mask on respiratory physiologic parameters and comfort in acute hypercapnic respiratory failure (AHRF). DESIGN: A prospective randomized study. SETTING: A medical ICU. PATIENTS AND INTERVENTIONS: Fifteen patients with COPD and AHRF were consecutively and randomly assigned to two noninvasive ventilation (NIV) sequences with ACV and PSV mode, spontaneous breathing (SB) via nasal mask being used as control. ACV and PSV settings were always subsequently adjusted according to patient's tolerance and air leaks. Fraction of inspired oxygen did not change between the sequences. MEASUREMENTS AND RESULTS: ACV and PSV mode strongly decreased the inspiratory effort in comparison with SB. The total inspiratory work of breathing (WOBinsp) expressed as WOBinsp/tidal volume (VT) and WOBinsp/respiratory rate (RR), the pressure time product (PTP), and esophageal pressure variations (deltaPes) were the most discriminant parameters (p<0.001). ACV most reduced WOBinsp/VT (p<0.05), deltaPes (p<0.05), and PTP (0.01) compared with PSV mode. The surface diaphragmatic electromyogram activity was also decreased >32% as compared with control values (p<0.01), with no difference between the two modes. Simultaneously, NIV significantly improved breathing pattern (p<0.01) with no difference between ACV and PSV for VT, RR, minute ventilation, and total cycle duration. As compared to SB, respiratory acidosis was similarly improved by both modes. The respiratory comfort assessed by visual analog scale was less with ACV (57.23+/-30.12 mm) than with SB (75.15+/-18.25 mm) (p<0.05) and PSV mode (81.62+/-25.2 mm) (p<0.01) in our patients. CONCLUSIONS: During NIV for AHRF using settings adapted to patient's clinical tolerance and mask air leaks, both ACV and PSV mode provide respiratory muscle rest and similarly improve breathing pattern and gas exchange. However, these physiologic effects are achieved with a lower inspiratory workload but at the expense of a higher respiratory discomfort with ACV than with PSV mode.

Acute Disease↗
PubMed1996

A randomized cross-over comparison of the hemodynamic response to intermittent hemodialysis and continuous hemofiltration in ICU patients with acute renal failure.

OBJECTIVE: To compare the hemodynamic response of ICU patients with acute renal failure of a 24-h continuous arteriovenous hemofiltration (CAVH) and that of patients with a 4-h intermittent hemodialysis (HD). DESIGN: Cross-over randomized clinical trial. The two periods to be compared were a 24-h CAVH and the 24-h encompassing a 4-h HD. These two periods were separated by a 24-h wash-out period. SETTING: Ten bed medicosurgical ICU of a tertiary care center in Paris, France. PATIENTS: Inclusion criterion was the requirement of replacement therapy for acute renal failure in patients already submitted to mechanical ventilation. INTERVENTIONS: CAVH was performed with Ringers' lactate used for restitution and infused before the hemofilter. The ultrafiltrate output was maintained at around 15 ml/min. HD was performed with a bicarbonate-buffered dialysate. MEAN OUTCOME MEASURES: Mean arterial pressure (MAP), use of adrenergic drugs, and change in body weight during each period. RESULTS: Twenty-seven consecutive patients were included, 15 CAVH-HD and 12HD-CAVH. CAVH and HD allowed the same metabolic efficacy. No hemodynamic parameter (MAP, amount of adrenergic drugs, change in body weight) differed between the two methods. CONCLUSIONS: CAVH is equivalent to HD in terms of MAP and the use of vasopressive drugs and fluids. Establishing the superiority of CAVH would require carefully controlled studies assessing either outcome or changes in tissue oxygenation.

Acute Kidney Injury↗
PubMed1996

Bordetella bronchoseptica pneumonia with shock in an immunocompetent patient.

Bordetella bronchoseptica is a rarely reported cause of human infection, but is a common respiratory tract commensal of mammals. Human infection with B. bronchoseptica is almost always associated with severe underlying disease and contact with an appropriate animal reservoir. We report a case of pneumonia with shock caused by B. bronchoseptica in an immunocompetent patient.

Animals↗
PubMed1994

Circulating interleukin-8 concentrations in patients with multiple organ failure of septic and nonseptic origin.

OBJECTIVES: Interleukin (IL)-8, a pro-inflammatory cytokine, is a potent chemoattractant factor and an activator of neutrophils produced by many cell types after stimulation by IL-1, tumor necrosis factor (TNF), or microbial products such as endotoxins. We investigated whether the presence of measurable IL-8 in plasma was associated with the clinical status of severely ill septic or nonseptic patients susceptible to the development of multiple organ failure. DESIGN: Cohort study. SETTING: A collaborative study between an intensive care unit and a research laboratory. SUBJECTS: Circulating IL-8 concentrations were measured in the plasma of 27 patients with sepsis syndrome and in 16 patients with noninfectious shock because these two conditions put patients at risk for the development of multiple organ failure. Sixteen of 27 patients with severe infection and 13 of 16 patients with noninfectious pathologies developed multiple organ failure. MEASUREMENTS AND MAIN RESULTS: A specific enzyme-linked immunosorbent assay (ELISA) for IL-8 was set up with a monoclonal and a rabbit polyclonal antihuman IL-8 using a sandwich technique. High concentrations of circulating IL-8 were found in the plasma of patients with sepsis syndrome. Among septic patients, a significant difference was observed between concentrations of IL-8 in survivors (n = 16) and nonsurvivors (n = 11) (81 +/- 13 pg/mL vs. 3326 +/- 1219 pg/mL, respectively; p = .001). A correlation was noticed between plasma IL-8 and IL-6 concentrations (r2 = .42; p = .001), while no correlation was observed between IL-8 and TNF-alpha values, or between IL-8 and IL-1 beta. Although the mortality rate of nonseptic, multiple organ failure patients was 92%, low plasma concentrations of IL-8 were found (78 +/- 34 pg/mL), while high plasma concentrations were measured in septic, multiple organ failure patients (mortality rate 69%) who were sampled at a similar stage. By contrast, increased IL-6 values were observed in both septic and nonseptic, multiple organ failure patients. CONCLUSIONS: In septic patients, high amounts of circulating IL-8 concentrations correlate with fatal outcome, whereas only low plasma concentrations of IL-8 are present in patients with nonseptic, multiple organ failure. This finding suggests that the signals involved in the exacerbation of IL-8 production are different, depending on infectious or noninfectious etiology.

Aged↗
PubMed1992

[Erythroderma induced by teicoplanin].

We report the case of a 38-year old man who developed erythroderma during treatment with teicoplanin for staphylococcal septicaemia. The clinical symptoms, which included high fever, shock and erythroderma, were suggestive of staphylococcal toxic shock. After teicoplanin was withdrawn and replaced by vancomycin the disease followed a favourable course. The reintroduction test was positive. This case illustrates the problems associated with the diagnosis of erythroderma in intensive care patients and confirms that it is possible to prescribe vancomycin in cases with allergic reaction to teicoplanin.

Adult↗
PubMedDate not supplied

[Malignant Neuroleptic Syndrome during tiapride treatment].

Tiapride, a benzamide compound, is a neuroleptic drug used in the treatment of some behavior troubles, especially in the alcohol withdrawal syndrome. We report a new case of malignant neuroleptic syndrome during a tiapride treatment in a 39 year-old alcoholic patient who had been admitted after a minor trauma. Symptoms were typical, with malignant hyperthermia in the absence of sepsis, coma, extrapyramidal syndrome, rhabdomyolysis, and severe metabolic acidosis. Dantrolene succeeded to reverse hyperthermia and rigidity; probably due to its delayed administration however, irreversible acidosis led to the patient's demise.

Adult↗