PubMed Health⌕ Search

Biomedical subjects

D Mathieu

Publications and source records attributed to D Mathieu.

At least 37 records · Page 2Linked to original sources
PubMed2001

[Hyperbaric oxygen for the treatment of necrotizing fasciitis].

Necrotizing fasciitis (NF) is a severe often life threatening bacterial infection. There are 2 main reasons to use hyperbaric oxygen (HBO2): the polymorphism of the bacterial flora with a predominance of anaerobes, either strict or aerotolerant; and the tissular necrosis due to an extensive disseminated microvascular obstruction within the infected area. Association of HBO2 to antibiotics and surgery is based on strong pathophysiological findings as well as on evidences from animal studies. Clinical evidence in human is still lacking even if published data supports its use in severe cases. Controversy on its use as a treatment for NF is caused more by the difficulty to dispose of a hyperbaric equipment allowing for the management of a patient in critical state, than by doubt on its real efficiency.

Animals↗
PubMed2001

Carbon monoxide poisoning: interpretation of randomized clinical trials and unresolved treatment issues.

Since hyperbaric oxygen therapy (HBO2) appeared as a treatment for CO poisoning in 1960, whether and when to use it for CO poisoning have often been debated. HBO2 has been advocated to treat severe CO poisoning to limit delayed and permanent neurologic sequelae. Initially, inferences about efficacy were based on clinical experience and uncontrolled studies, but since1989, six prospective clinical trials have been reported comparing HBO2 and normobaric O2 administration to treat patients with acute CO poisoning. Of the six trials, four found better clinical outcomes among patients receiving HBO2 while two have shown no treatment effect. The most recent and best-designed randomized controlled clinical trial, performed in Salt Lake City, supports the efficacy of HBO2 in severe acute CO poisoning in accordance with scientific rationale and clinical experience. However, a number of important issues remain for future investigation, which could be addressed in a large multi-center trial. Such a trial should attempt to determine the optimal number of HBO2 treatments and the maximum treatment delay from CO poisoning for HBO2 to provide efficacy in patients with specific risk factors for a poor outcome.

Carbon Monoxide Poisoning↗
PubMed2000

Oral contraceptive use and focal nodular hyperplasia of the liver.

BACKGROUND & AIMS: Because most patients with focal nodular hyperplasia (FNH) are young women, an important decision is whether to discontinue oral contraceptive (OC) use. The aims of this study were to evaluate (1) the number and size of FNH lesions in women with various patterns of OC use and in women without OC use and (2) the modifications in the number and size of FNH lesions during follow-up, according to OC use. METHODS: In a 9-year study in 216 women with FNH, the diameter and number of lesions documented by magnetic resonance (MR) imaging were evaluated (1) at diagnosis according to OC use as follows: group A, no OC use (n = 28); group B, high-dose OC use (n = 46); group C, low-dose OC use (n = 98); group D, successive use of high-dose and low-dose OCs (n = 33); and group E, use of progestogens only (n = 11); and (2) during follow-up in 136 women, 14 of whom were OC nonusers who stayed off OCs, 89 discontinued OC use, 26 took low-dose OCs, and 7 stayed on a progestogen only. Twelve women became pregnant. In 168 women, the diagnosis of FNH was made based on a combination of rigorously defined MR criteria. In the remaining 48 patients, diagnosis was by surgical biopsy (n = 36) or resection (n = 12). Mean diameter and number of lesion(s) per patient were assessed by MR imaging using the same protocol in all study patients. RESULTS: No significant differences in the number or size of lesions were found in the 5 patient groups. During follow-up, a change in lesion diameter occurred in only 4 women; this event was not influenced by OC use. In the 12 patients who became pregnant, lesion size was unchanged after delivery, pregnancy was uneventful, and delivery occurred spontaneously. CONCLUSIONS: These data suggest that (1) neither the size nor the number of FNH lesions are influenced by OC use; (2) size changes during follow-up are rare and do not seem to depend on OC use; and (3) pregnancy is not associated with FNH changes or complications.

Adolescent↗
PubMed2000

Placement of a fenestrated Palmaz stent across the renal arteries. Feasibility and outcome in an animal study.

OBJECTIVES: To investigate the feasibility of placing stents across renal arteries. Design we have studied in pigs: (i) the feasibility of accurately placing a fenestrated stent in front of one renal ostium; (ii) the short-term effects on renal arteries and function after the placement of such a fenestrated stent. MATERIALS AND METHODS: Eight fenestrated Palmaz stents were placed over pigs' renal ostia under fluoroscopy. Five weeks later, angiograms were performed and the animals were sacrificed. Proliferation of the healing tissues over the ostia was measured and analysed by microscopy. Serum creatinine was measured prior to all angiograms and at 5 weeks. RESULTS: All eight stents were correctly placed. One stent later migrated and was excluded from the study. One pig died at day 1. Gross examination confirmed the correct placement of the fenestrations in four pigs out of seven (57%). In the six remaining pigs, at 5 weeks, there was no angiographic evidence of stent misplacement and all the kidneys were fully perfused. Nine renal ostia were covered by struts and neointima with a mean area of coverage of 38+/-5% altogether. No tissue proliferation was observed over the three renal ostia located in front of the fenestration. Serum creatinine did not significantly increase at 5 weeks. CONCLUSION: Creating a fenestration in a stent for renal arteries may be worth while in order to avoid neointimal covering of the renal ostia. However, accurate placement of such a fenestrated stent remains a difficult task.

Animals↗
PubMed2000

Acute occlusion of popliteal and/or tibial arteries: the value of percutaneous treatment.

OBJECTIVES: to describe early and mid-term results with a percutaneous therapeutic protocol including thromboaspiration, thrombolysis, and correction of the underlying lesion by PTA. METHODS: thirty-three consecutive selected patients with recent (<1 month) reversible acute ischaemia associated with popliteal and/or tibial occlusion were studied. The primary endpoints were technical success (defined as residual mural thrombus less than 20% of the lumen and the presence of at least one tibial artery on angiogram), patient survival and limb salvage at 1 and 12 months. Secondary endpoints included complications, primary, assisted primary and secondary patency determined by duplex scan at 1, 6 and 12 months. RESULTS: technical success was achieved in 27 patients (82%). Twenty patients were treated by thrombo- aspiration+/-thrombolysis only, and seven required additional PTA (26%). In six patients (18%), percutaneous techniques failed, and embolectomy was performed in two, bypass in one and major amputations in three (9%). For the entire series, the survival rate was 100% at 1 month and 94% at 1 year. The limb salvage rate was 91% at 1 month and 1 year. The cumulative primary patency, assisted primary patency and secondary patency rates were 81%, 81% and 86% respectively at 1 month and 66%, 72% and 77%, respectively, at 12 months. Early complications occurred in 10 patients (30%): five groin haematomas (15%), four compartment syndromes (12%) and one haemoglobinuria (3%). CONCLUSION: percutaneous techniques offer excellent early and mid-term results in selected patients presenting with acute ischaemia with popliteal and/or tibial arteries occlusion.

Acute Disease↗
PubMed2000

Inhaled nitric oxide modulates leukocyte kinetics in the mesenteric venules of endotoxemic rats.

OBJECTIVE: to determine whether inhaled nitric oxide (NO) would alter leukocyte kinetics in the septic microvasculature. DESIGN: Randomized, controlled trial. SETTING: Experimental laboratory. SUBJECTS: Male Sprague Dawley rats. INTERVENTIONS: Rats were treated with either saline or endotoxin (10 mg/kg, iv) and then allowed to breathe either air or air plus NO (10 ppm). MEASUREMENTS AND MAIN RESULTS: After a 4-hr period, rolling, firm adhesion, and emigration of leukocytes and endothelial dysfunction were monitored in mesenteric venules by using intravital videomicroscopy. Compared with controls, endotoxemic rats exhibited a profound influx in mesenteric venule rolling leukocytes (55+/-17 vs. 70+/-19 leukocytes/min; p < .05), associated with a reduction of leukocyte rolling velocity (83+/-14 vs. 34+/-3 microm/sec; p < .05). In endotoxemic rats, venular endothelium leukocyte firm adhesion (1.15+/-0.32 vs. 4.08+/-0.96 leukocytes/ 100 microm; p < .05) and emigration (0.84+/-0.47 vs. 4.23+/-1.2 leukocytes/100 microm; p < .05) increased compared with controls. Inhaled NO had no effect on leukocyte kinetics in control rats. Inhaled NO significantly attenuated endotoxin-induced venular endothelium leukocyte adhesion (4.08+/-0.96 vs. 1.86+/-0.76 leukocytes/100 microm; p < .05) and emigration (4.23+/-1.2 vs. 1.68+/-0.72 leukocytes/100 microm; p < .05). Compared with control rats, macromolecular (FITC-dextran) vascular leakage, expressed as the perivenular/intravenular fluorescence intensity ratio, increased in endotoxemic rats (0.56+/-0.02 vs. 0.81+/-0.05; p < .01). Endotoxin-induced macromolecular vascular leakage increases were partially prevented by inhaled NO (0.66+/-0.01 vs. 0.56+/-0.02; p < .05). CONCLUSION: These observations suggest that inhaled NO reduces leukocyte adhesion and the degree of vascular permeability dysfunction in mesenteric venule of endotoxemic rats.

Administration, Inhalation↗
PubMed2000

Percutaneous stenting of an latrogenic superior mesenteric artery dissection complicating suprarenal aortic aneurysm repair.

PURPOSE: To report endovascular repair of an iatrogenic superior mesenteric artery (SMA) dissection caused by a balloon occlusion catheter. CASE REPORT: A 68-year-old man with a suprarenal aortic aneurysm underwent conventional prosthetic replacement, during which visceral artery back bleeding was controlled with balloon occlusion catheters. Six hours postoperatively, the patient experienced an episode of bloody diarrhea with abdominal pain and tenderness and mild metabolic acidosis. Colonoscopy revealed colitis (grade I) without necrosis of the right and left colon. An emergent abdominal computed tomographic scan showed signs of mesenteric ischemia with bowel dilatation and SMA wall hematoma; angiography identified a dissection 1 cm distal to the SMA origin. An Easy Wallstent was deployed percutaneously, successfully reestablishing SMA patency. The postoperative course was uneventful, and the patient remains asymptomatic with a patent SMA stent and aortic graft at 1 year. CONCLUSIONS: latrogenic SMA dissection should be suspected after suprarenal aortic aneurysm repair if signs of mesenteric ischemia arise. Prompt and thorough imaging studies are necessary to confirm the diagnosis and assess the potential for an endoluminal treatment.

Aged↗
PubMed2000

Effects of breathing air at 4 atm abs: evidence for a change in strategy.

The effect of breathing air at 4 atm abs on two tasks was investigated. For the recognition memory task, subjects learned a list of symbols in anticipation of a recognition test. The second task was a speed test in which subjects were instructed to detect all occurrences of a given target. A signal detection analysis of performance to the recognition test showed that sensitivity index was invariant, but the criterion (beta) became stricter under hyperbaric pressure. For the speed test, the results showed that under pressure the error rate increased progressively with time while the working speed remained constant. It is argued that strategic variables may be particularly sensitive to the hyperbaric environment.

Analysis of Variance↗
PubMed2000

[Role of microcirculation in multiorgan failure of infectious origin].

The normal host response to infection is a complex process which serves to localize and control bacterial invasion and to initiate repair of injured tissue. This inflammatory process is accompanied by activation of circulating and fixed phagocytic cells and generation of pro-inflammatory and anti-inflammatory mediators. Sepsis results when the prerequisite inflammatory response to infection becomes generalized, and thereby extends to involve otherwise normal tissue which is remote from the initial site of injury or infection. Sepsis is typically associated to cardiovascular alterations that have been characterized by increases in oxygen delivery to the tissues. Paradoxically, the host's systemic inflammatory response syndrome may simultaneously disturb the ability to adequately match tissue oxygen needs and availability at a time when tissue oxygen needs are typically increased. Depressed tissue oxygen availability relative to augmented needs may result from dysfunction at all of the central, regional, and microregional levels of the circulation. Significant dysregulation in the process by which oxygen availability is usually matched to changing tissue oxygen needs is typical associated with changes the microvascular blood flow behavior, vascular reactivity and endothelial and leukocyte activation. Specific tools developed to explore the microcirculation have been applied in the setting of both human and animal models sepsis. Abnormalities observed in the septic microvasculature are characterized by reductions in cutaneous and skeletal muscle blood flow and in mucosal intestinal ischemia and hypoxia. Regarding the skeletal muscle organ system, microvascular abnormalities were further characterized by an impairment of blood flow to increase in response to oxygen need increase. Also, microvascular abnormalities in the intestine were associated with evidence of endothelial and leukocyte activation leading to epithelial dysfunction. Thus, sepsis appears to be associated with early onset microvascular dysfunction. The relationship between microvascular dysfunction and endothelial and leukocyte activation leading to organ failure has been suggested by numerous studies.

Blood Flow Velocity↗
PubMed1999

Development of 5-iodo-2'-deoxyuridine milling process to reduce initial burst release from PLGA microparticles.

The aim of this study was to prepare 5-iodo-2'-deoxyuridine (IdUrd) loaded poly(d,l-lactide-co-glycolide) (PLGA) microspheres with a reduced initial burst in the in vitro release profile, by modifying the drug grinding conditions. IdUrd particle size reduction has been performed using spray-drying or ball milling. Spray-drying significantly reduced drug particle size with a change of the initial crystalline form to an amorphous one and led to a high initial burst. Conversely, ball milling did not affect the initial IdUrd crystallinity. Therefore, the grinding process was optimized to emphasize the initial burst reduction. A first step allowed us to set qualitative parameters such as ball number (7) and cooling with liquid nitrogen to obtain a mean size reduction and a narrow distribution. In a second step, three parameters including milling speed, drug amount and time were studied by a response surface analysis. The interrelationship between drug amount and milling speed was the most significant factor. To reduce particle size it should be necessary to use a moderate speed associated with a sufficient drug amount (400-500 mg). IdUrd release from microparticles prepared by the o/w emulsion/extraction solvent evaporation process with the lowest crystalline particle size (15.3 microns) was studied. Burst effect could be reduced significantly. Concerning the first phase of drug release, the burst was 8.7% for 15.3 microns compared to 19% for 19.5 microns milled drug particles.

Chemistry, Pharmaceutical↗
PubMed1999

Colchicine poisoning: report of a fatal case with body fluid and post-mortem tissue analysis by high-performance liquid chromatography.

A case involving a suicide by the ingestion of colchicine tablets is presented. Liquid chromatography has been used to measure the drug level in blood and in post-mortem tissues of the patient (a 42-year-old man). Plasma concentration 24 h after ingestion was 4.5 ng/mL. On autopsy, the kidney showed the highest concentration (396 ng/g). High concentrations were also found in the liver (347 ng/g) and heart (334 ng/g). Low concentrations were detected in the lung (58 ng/g), muscle (10 ng/g) and brain (5 ng/g).

Adult↗
PubMed1999

Unexpected MR-T1 enhancement of endocrine liver metastases with mangafodipir.

With the use of available liver magnetic resonance contrast agents, such as mangafodipir (Mn-DPDP), liver metastases do not exhibit enhancement on T1-weighted images. This absence of enhancement is due to the lack of hepatocytes within these tumors. The purpose of this report is to demonstrate an unexpected enhancement on T1-weighted images 30 minutes after injection of mangafodipir, in the case of endocrine liver metastases from a non-hyperfunctioning neuroendocrine pancreatic tumor. Different hypotheses could explain this unexpected enhancement, such as increased arterial tumoral flow or high metabolic activity. Contrary to liver metastases of other origins, Mn-DPDP enhancement can be present in neuroendocrine metastases. J. Magn. Reson. Imaging 1999;10:193-195.

Adenoma, Islet Cell↗