PubMed Health⌕ Search

Biomedical subjects

D Mathieu

Publications and source records attributed to D Mathieu.

At least 91 records · Page 5Linked to original sources
PubMed1996

[Indications for hyperbaric oxygen therapy. Organization of the treatment unit. Training of personnel].

Pathophysiologic mechanisms involved in the application of HBO therapy are poorly understood that may limit its clinical use. However, useful indications are well standardized in the setting of critical care medicine, CO poisoning, decompression sickness, gas gangrene and soft tissue anaerobic infections, crush syndrome, burns, sudden deafness... HBO therapy is also indicated in the management of chronic limb ischemia, diabetic foot lesion, osteomyelitis, osteoradionecrosis. These clinical indications have been evaluated in a Consensus Conference on Hyperbaric Medicine that has classified its application according to its efficiency. Indications were classified as strongly recommended (positively affects the patient's survival), recommended (does not influence the patient's survival but is important for the prevention of serious disorders) and optional (regarded as a additional treatment modality). Clinical application of HBO therapy requires specific equipment including a multiplace hyperbaric chamber and specific educational program and training for personnel employed in the clinical hyperbaric center. Lastly, HBO therapy is related to accurate rules defining its indications as well as its evaluation that are minimal prerequisites for safety and clinical results.

Atmosphere Exposure Chambers↗
PubMed1996

[Carbon monoxide poisoning: current aspects].

Carbon monoxide (CO) poisoning still represents a frequent and severe casualty in France. Aside the well-known effect of CO on hemoglobin, the role of CO binding to other hemoproteins like myoglobin and cytochrome a3 have been more recently recognized. Moreover, in addition to these hypoxic injuries, the reoxygenation phase may itself induce toxic effects by a mechanism close to the ischemia-reperfusion phenomenon. Clinical manifestations include neurologic disturbances, cardiac arrythmia, respiratory and circulatory failures which usually disappear with removal from toxic atmosphere and administration of oxygen. However, long term neurologic manifestations may occur and lead to important functional impairment and disability. Hyperbaric oxygen in actually the treatment of choice to avoid the occurrence of delayed sequelae. HBO is advocated in every patient who remains comatose on hospital admission, who had lost consciousness during toxic exposure or with persisting neurologic abnormalities. CO poisoned pregnant women should also undergo HBO. Well designed prevention programs are urgently needed in our country to decrease the incidence and the consequences of CO poisoning.

Carbon Monoxide Poisoning↗
PubMed1995

Impact of magnetic resonance imaging on the diagnosis of abdominal complications of paroxysmal nocturnal hemoglobinuria.

Magnetic resonance (MR) imaging is a method of choice for assessing vascular patency and parenchymal iron overload. During the course of paroxysmal nocturnal hemoglobinuria (PNH), it is clinically relevant to differentiate abdominal vein thrombosis from hemolytic attacks. Furthermore, the study of the parenchymal MR signal intensity adds informations about the iron storage in kidneys, liver, and spleen. Twelve PNH patients had 14 MR examinations of the abdomen with spin-echo T1- and T2-weighted images and flow-sensitive gradient echo images. Vessels patency and parenchymal signal abnormalities--either focal or diffuse--were assessed. MR imaging showed acute complications including hepatic vein obstruction in five patients, portal vein thrombosis in two patients, splenic infarct in one patient. In one patient treated with androgens, hepatocellular adenomas were shown. Parenchymal iron overload was present in the renal cortex of eleven patients with previous hemolytic attacks. On the first MR study of the remaining patient with an acute abdominal pain showing PNH, no iron overload was present in the renal cortex. Follow-up MR imaging showed the onset of renal cortex iron overload related to multiple hemolytic attacks. Despite the fact that all our patients were transfused, normal signal intensity of both liver and spleen was observed in three of them. MR imaging is particularly helpful for the diagnosis of abdominal complications of PNH.

Abdominal Pain↗
PubMed1995

The effects of donor and recipient endotoxemia on TNF alpha production and mortality in the rat model of syngenic orthotopic liver transplantation.

The effects of administration of endotoxin to donors or recipients on the mortality rate, evolution of endotoxin levels, and tumor necrosis factor alpha (TNF-alpha) release were investigated in a syngenic orthotopic liver transplantation model in Lewis rats with portal reperfusion only. No significant recipient endotoxemia, TNF-alpha release, or mortality occurred in control recipients following transplantation from normal donors. The doses of endotoxin needed to kill 50% and 100% of animals after hepatic artery ligation were, respectively, 4 mg/kg and 10 mg/kg. Transplantation of animals' livers with no preservation phase from donors who were administered a lethal dose of endotoxin for this combination (10 mg/kg) produced significant recipient endotoxemia at 10 min (6.9 +/- 2.5 x 10(3) endotoxin unit/ml (EU/ml), P < 0.01), 45 min (8.8 +/- 1.1 x 10(3) EU/ml, P < 0.001) and 8 hr (18.5 +/- 3.5 x 10(3) EU/ml, P < 0.001) after graft reperfusion. Significant levels of TNF-alpha were also detected in these animals at 45 min (280 +/- 70 pg/ml, P < 0.007) and 8 hr (80 +/- 40 pg/ml, P < 0.05) when compared with the controls. Mortalities in recipients of OLT from donor animals that had received endotoxin (2 mg/kg or 4 mg/kg) immediately prior to the harvesting procedure was 0% and 20%, respectively, compared with no death in the control group. When recipient animals were administered endotoxin immediately after graft reperfusion the resistance to endotoxin administration was significantly reduced compared with animals that had not received OLT (LD50 < 2 mg/kg versus 4 mg/kg; LD100 4 mg/kg versus 10 mg/kg, respectively). These results show that endotoxin and its effects can be transferred from the liver graft donor to the recipient and that OLT per se reduces the recipient resistance to endotoxin with subsequent increase in mortality.

Animals↗
PubMed1995

Hyperbaric oxygenation in severe perineal Crohn's disease.

PURPOSE: Perineal involvement in Crohn's disease is a common and distressing condition, often refractory to medical or surgical treatments. Recent reports suggest the efficacy of hyperbaric oxygenation (HBO) in the healing of perineal lesions. We evaluated HBO in severe patients with perineal Crohn's disease. METHODS: Ten consecutive patients (8 women, 2 men; mean age, 30 years) were studied. There were four superficial fissures, four cavitating ulcers, six low or superficial fistulas, two high fistulas, and one irreversible anal stenosis. All patients had received one or more medical treatments without healing the perineal lesions, and all had had previous surgery for perineal lesions. RESULTS: Two patients discontinued HBO after a few sessions and did not complete treatment. Eight patients completed at least 30 HBO sessions and were evaluable. At the end of the procedure, six of eight patients treated were healed, three completely and three partially. All patients who healed completely received HBO as an additional treatment to local perineal surgery. CONCLUSION: HBO might be useful as a last resort treatment of chronic perineal Crohn's disease, resistant to other treatments or as a complement to surgery.

Adult↗
PubMed1995

Intraarticular tolerability and kinetics of gadolinium tetra-azacyclododecane tetraacetic acid.

RATIONALE AND OBJECTIVES: We assessed the tolerability and the intraarticular kinetics of gadolinium tetra-azacyclododecane tetraacetic acid (Gd-DOTA) using magnetic resonance (MR) imaging. METHODS: Twelve of 18 dogs received an intraarticular injection of Gd-DOTA solution. Pathologic examination of all joints was performed with assessment of Gd-DOTA bone absorption. Effects of Gd-DOTA on chondrocyte viability and proliferation in vitro were determined using cultures of rabbit chondrocytes. Four dogs underwent MR imaging of the stifle joint before and after intraarticular injection of 0.8 ml Gd-DOTA at a concentration of 2 mmol/l (300 mOsm/l). Intraarticular kinetics of Gd-DOTA were determined from quantitative measurements using repeated sagittal spin-echo T1-weighted images. RESULTS: No microscopic changes of the joints or Gd-DOTA bone absorption were detected. No cytotoxicity for chondrocytes was observed at a concentration of 5 mmol/l, but a decreased cell count was observed at a high concentration (50 mmol/l). The intraarticular Gd-DOTA concentration decreased with time according to a logarithmic curve with an intraarticular half-life of 103-152 min (M = 127 min). CONCLUSION: Gd-DOTA is a safe intraarticular contrast agent with a long half-life in the joint cavity.

Absorption↗
PubMed1995

Cervical necrotizing fasciitis: clinical manifestations and management.

Forty-five cases of cervical necrotizing fasciitis are reported, and their clinical, bacteriologic, and therapeutic implications are considered. Fasciitis was of dental origin in 78% of cases, pharyngeal in 16%, and surgical or posttraumatic in 6%. The condition extended to the face in 22% of cases, to the lower part of the neck in 56%, and to the mediastinum in 40%. Soft-tissue cultures were positive in 78% of cases. Anaerobes were isolated along with aerobes in 49% of cases (mean, 2.2 isolates per patient) and in pure culture in 22%. Treatment included surgical debridement and drainage and the administration of antibiotics active against both anaerobic and gram-negative aerobic bacteria. Hyperbaric oxygen was used for adjunctive treatment. The bacteria involved did not affect clinical manifestations, extension, or mortality. The survival rate among our patients was 78%. Mortality was significantly higher among cases with mediastinal extension (44% vs. 7%; P < .01); thus the prompt recognition and drainage of sites of mediastinal extension are of critical importance. Other risk factors for death were an age of > 70 years, underlying diabetes, the development of septic shock within 24 hours after admission, and prolonged prothrombin time.

Adolescent↗
PubMed1995

Prevention of thrombotic complications of the nephrotic syndrome by the low-molecular-weight heparin enoxaparin.

The nephrotic syndrome (NS) carries one of the highest risks of thrombotic complications. Consequently, over the last 15 years, some nephrologists have treated patients risk (i.e. those with albuminemia < 20 g/l and membranous nephropathy) with anticoagulants: either subcutaneous heparin (Kakkar protocol) or antivitamin K. Low-molecular-weight heparin (LMWH) has a longer plasma half-life and better bioavailability than standard heparin and can thus be administered as a single daily injection. LMWH also carries a lower risk of hemorrhage. We prospectively studied the safety and efficacy of the LMWH Enoxaparin for preventive anticoagulation in NS. In a preliminary study, 10 adult nephrotic patients with biological markers of thrombosis risk (severe hypoalbuminemia and/or anomalies of the fibrinolytic pathway and/or deficiency in coagulation inhibitors) were given 40 mg (4,000 U) of Enoxaparin daily for at least 3 months; 3 patients were treated for 3 months, 1 for 6 months and 6 for 12 months. Patients were assessed for silent thrombosis, using renal vein Doppler ultrasonography, lower leg vein Doppler ultrasonography and lung ventilation-perfusion scintigraphy, before entry to the trial and subsequently at 3-month intervals. As LWMH caused no obvious side effects and no thrombosis was observed during the pilot study, we then placed 55 adult nephrotic patients free of thrombosis on the same treatment. Patients were seen according to the usual calendar required by their individual illnesses. At each examination, patients were assessed for clinical signs and symptoms of thrombosis and side effects; plasma D-dimer and urinary fibrin-fibrinogen degradation products were also measured at each visit.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Diagnostic tests for pneumonia in ventilated patients: prospective evaluation of diagnostic accuracy using histology as a diagnostic gold standard.

The diagnostic accuracy of protected-specimen brush (PSB), bronchoalveolar lavage (BAL), and endotracheal aspirates (EA) was prospectively evaluated in a series of 28 mechanically ventilated patients (MV patients) who died within 3 d of the bronchoscopic procedure, using postmortem lung examination as the gold standard for establishing the diagnosis of pneumonia. The entire fixed lungs were carefully dissected along the bronchovascular axes and each segment was cut into 5- to 10-mm thick sections, enabling gross examination of the lung parenchyma. Two tissue blocks were taken from each segment, including grossly abnormal areas whenever present. In several cases, two peripheral (subpleural) lung-tissue blocks were also taken from each lobe prior to systematic dissection of the lungs. Quantitative cultures (QC) and direct cytologic and microbiologic examination (DE) was performed on respiratory samples obtained within 72 h before death. Values of 10(3) cfu/ml of Ringer's solution, 10(4) cfu/ml of retrieved fluid, and 10(6) cfu/ml of respiratory secretions were used as cutoff points for quantitative PSB, BAL, and EA cultures, respectively. The main findings in this study were that: (1) Pneumonia was present in 67% of the patients. (2) Histologic lesions of pneumonia were mainly bilateral and predominated in the dependent lung segments. (3) Coexistence of a variety of noninfectious processes was a common finding in patients with pneumonia. (4) In several cases pneumonia was absent from peripheral lung samples while more central areas of the same segment displayed typical foci of pneumonia. (5) The sensitivity of quantitative cultures was 55%, 57%, and 47% for EA, PSB, and BAL, respectively, and the specificity was 85%, 88%, and 100%, respectively. Reducing the diagnostic threshold of EA to 10(5) cfu/ml of respiratory secretions instead of 10(6) cfu/ml resulted in a sensitivity of 63.1% and a specificity of 75% for EA. The sensitivity of direct examination (DE) was 50%, 47%, and 47%, respectively, and the specificity was 75%, 88%, and 87%. (6) The presence of intracellular organisms (ICO) in BAL had a 36.8% sensitivity and 100% specificity in establishing the diagnosis of pneumonia regardless of their percentage. (7) Although 15 patients (53%) were not on antibiotics or were off antibiotics for more than 48 h before testing, no relationship could be established between the patients' antibiotic status and the result of any diagnostic test. By using a recommended methodology for respiratory sampling techniques together with complete postmortem lung examination as a diagnostic "gold standard," this study provides a realistic insight into the diagnostic values of EA, PSB, and BAL in MV patients with suspected pneumonia.

Biopsy↗
PubMed1995

Hepatocellular adenoma: MR imaging features with pathologic correlation.

OBJECTIVE: The purpose of this study was to describe the MR imaging characteristics of hepatic adenomas and to correlate these features with pathologic findings. MATERIALS AND METHODS: Sixteen patients from four institutions who had 31 hepatocellular adenomas underwent MR imaging with T1- and T2-weighted pulse sequences at 1.5 T. Dynamic gadolinium-chelate-enhanced gradient-recalled-echo (GRE) MR imaging was done in eight patients with 15 lesions. Twenty-three lesions in 15 patients were confirmed by surgical excision. MR images were retrospectively reviewed by three experienced radiologists for signal intensity of lesions relative to liver, heterogeneity, contrast enhancement, and presence of signs of histopathologic correlates. These imaging findings were then compared with histopathologic findings. RESULTS: Nearly all (29 of 31 lesions) hepatocellular adenomas showed heterogeneous signal intensity on MR images. Most (19/31) were predominantly hyperintense on proton density- or T2-weighted images; the predominant signal intensity on T1-weighted images varied. Thirteen of 15 lesions showed early arterial enhancement relative to liver on dynamic GRE MR images. MR imaging was most successful in showing intratumoral hemorrhage (10 of 12 histopathologically proven lesions), large intratumoral vessels (five of five), fatty change (three of six), and peliosis (three of three cases). In two lesions, capsules (one of five) and central scars (one of three) were detected. CONCLUSION: Hepatocellular adenomas have a highly variable appearance on MR images because of their varied histologic appearances. Although no definitive MR imaging signal or structural characteristics can be identified, tumor heterogeneity, particularly when related to hemorrhage, and early arterial enhancement can suggest a diagnosis of hepatocellular adenoma in the proper patient population.

Adenoma, Liver Cell↗
PubMed1995

Management of focal nodular hyperplasia and hepatocellular adenoma in young women: a series of 41 patients with clinical, radiological, and pathological correlations.

Preoperative distinction between focal nodular hyperplasia (FNH) that should be managed conservatively and hepatocellular adenoma (HA) that should be resected remains difficult. The result is controversial management of these patients. The aims of this study were to report the value of modern imaging procedures for noninvasive diagnosis of these lesions, to assess the value of intraoperative frozen section studies, and to propose a management strategy in those patients. Forty-one consecutive women with FNH (35 cases) or HA (6 cases) treated at our institution between 1985 and 1992 were studied. New imaging techniques, including enhanced magnetic resonance imaging (MRI) and color Doppler ultrasonography (US), were prospectively appraised in addition to usual techniques. Histological examination of surgical specimens was obtained in all cases. A sixfold increase in the number of patients with FNH was observed during this study, whereas the number of patients with HA did not change. FNHs were incidental US findings in 74% of the cases. The best imaging procedure in the diagnosis of FNH was enhanced MRI with a sensitivity of 70% and a specificity of 98%. Color Doppler US was a useful adjunct. Intraoperative frozen section studies were performed in 16 patients with 19 tumors with a sensitivity of 89% and a specificity of 100%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenoma, Liver Cell↗
PubMed1995

Clinical evaluation of the Vital system compared with the Hémoline diphasic method for the detection of aerobic blood cultures.

In a collaborative study at two university hospitals, the recovery of microorganisms and the speed of detection of microbial aerobic growth by the Vital system (bioMérieux) and a diphasic conventional blood culture system were compared. The Vital system monitors each blood culture bottle every 15 minutes to detect inactivation of fluorescent suspended in the broth medium due to microbial growth. A total of 1086 comparisons were made between the two systems, yielding a total of 117 isolates. Microorganisms were recovered more often from the Vital aerobic bottles (p < 0.05). The Vital system detected 43% of the microorganisms within the first 12 hours of incubation whereas in the same time the conventional system detected only 5% of the microorganisms. The results demonstrate that the Vital system is a reliable, continuous monitoring, fully automated system and an attractive alternative to conventional blood culture methods.

Bacteremia↗
PubMed1995

Magnetic resonance imaging of penile rupture: aid to diagnosis.

We report on a patient with atypical clinical findings in whom magnetic resonance imaging confirmed the suspicion of penile rupture. The tear appeared as an obvious discontinuity of the low signal intensity of the tunica albuginea and was associated with a hematoma. We conclude that magnetic resonance imaging is useful for confirming the diagnosis of penile rupture when clinical findings are atypical, indicating surgical repair.

Adult↗
PubMed1995

Long-term clinical and virological outcome after liver transplantation for cirrhosis caused by chronic delta hepatitis.

Liver transplantation for liver diseases related to hepatitis B virus (HBV) and hepatitis delta virus (HDV) remains problematic because of the risk of viral recurrence. We report here the long-term virological outcome of patients transplanted for HDV-related liver cirrhosis (HDV cirrhosis). From December 1984 to December 1990, 76 patients with HDV cirrhosis underwent liver transplantation. Before transplantation, all the patients were HBsAg-positive/anti-HDV positive, and all but one were HBV DNA-negative by dot blot hybridization. HDV RNA was detected by HDV RT-PCR and liver HDAg by fluorescent HDV Ab. After transplantation, all the patients except four received continuous long-term anti-HBs passive immunoprophylaxis. The actuarial 5-year survival was 88%. All patients who did not receive anti-HBs immunoprophylaxis remained HBsAg-positive and developed hepatitis. Among the 68 patients receiving antiHBs immunoprophylaxis with a minimum follow-up of 2 months, HBsAg reappeared in 7 (10.3%) after a mean of 17 months. These seven patients developed hepatitis, with simultaneous HBV and HDV replication; and four cleared later HBsAg. Patients without HBV reinfection were studied for HDV reinfection: liver HD Ag or serum HDV RNA were present in 88% of the patients during the first year, without developing hepatitis; however, they were no longer detectable after 2 years in 95% of the patients. In conclusion, liver transplantation for HDV cirrhosis gives good results, with a 5-year actuarial survival of 88%.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗
PubMed1994

Carbon dioxide rebreathing method of cardiac output measurement during acute respiratory failure in patients with chronic obstructive pulmonary disease.

OBJECTIVE: To compare measurement of cardiac output by the CO2 rebreathing method vs. the thermodilution cardiac output technique in the setting of acute respiratory failure in patients with chronic obstructive pulmonary disease. DESIGN: Prospective, comparative study of two methods in a consecutive sample. SETTING: Intensive care unit. PATIENTS: Twenty-five patients with chronic obstructive pulmonary disease with acute respiratory failure were studied. The patients were being mechanically ventilated and monitored with systemic and pulmonary artery catheters. MEASUREMENTS AND MAIN RESULTS: Cardiac output was determined, using both the thermodilution technique and an indirect CO2 Fick method. Veno-arterial CO2 content difference was calculated from an estimated mixed venous PCO2 obtained by an equilibrium CO2 rebreathing method and measured PaCO2. PCO2 was converted to content using the equation of the CO2 dissociation curve described by McHardy. A wide range of cardiac output was studied. There was a significant correlation between thermodilution and CO2 rebreathing methods (r2 = .92, p < .001). The mean difference between thermodilution and CO2 rebreathing methods was -0.06 L/min/m2, standard deviation for the bias was 0.028 L/min/m2, and 95% confidence interval for the bias was -0.120 to -0.001 L/min/m2. CONCLUSION: Our results suggest that the CO2 rebreathing method may be a reliable non-invasive technique to determine cardiac output in mechanically ventilated patients with chronic obstructive pulmonary disease.

Acute Disease↗