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Biomedical subjects

A Denys

Publications and source records attributed to A Denys.

At least 19 recordsLinked to original sources
PubMed2006

[CT-angiography of peripheral arterial diseases: principle and current indications].

Recent advances in multi-detector CT technology, improving the spatial resolution and the acquisition time, provide basis for CT-angiography of the abdominal aorta and peripheral vessels of the lower extremities. The objective of this review is to help the clinician to understand principle of CT-angiography of peripheral vessels and to provide an overview of the current clinical applications as well as the futures directions in diagnosis, treatment planning and post-therapeutic surveillance in peripheral vascular diseases.

Contrast Media↗
PubMed2006

[CT-enteroclysis].

Computed tomography enteroclysis (CTE) has become a well-defined imaging modality for the evaluation of various small bowel disorders. The large volume (2 l) of enteral contrast agent administrated via a nasojejunal catheter ensures small bowel distension. Following helical CT acquisition is completed by multiplanar views. CTE is of particular value in intermediate or advanced Crohn's disease. It has become the method of choice for small bowel tumours. The cause and degree of low-grade small bowel obstruction is more readily analyzed with the technique of CTE than conventional CT. CTE should be selectively used to answer specific questions of the small bowel. It essentially contributes to the diagnostic quality of modern small bowel imaging, and therefore deserves an established, well-defined place among the other available techniques.

Humans↗
PubMed2006

Lead cations affect the control of both meiosis arrest and meiosis resumption of the mouse oocyte in vitro at least via the PKC pathway.

The aim of this study was to determine in vitro whether lead has a direct cytotoxic effect on the female gamete or through its surrounding somatic cells. We had previously demonstrated that it partly accumulates in the mouse ovary and induces follicle and oocyte apoptosis. The data reported here demonstrate for the first time that low levels of Pb(NO3)2 (<or=10 pM) affect oocyte meiosis in vitro. On the one hand, in condition similar to the in vivo one, i.e. in hypoxanthine (HX)-maintained meiotic arrest, Pb(NO3)2 was able to significantly release the oocytes from this arrest. On the other hand, when meiosis occurred spontaneously in vitro, Pb(NO3)2 inhibits meiosis. Whereas PMA, an agonist of PKC was able to prevent the first lead effect, calphostin C, an antagonist, was able to significantly prevent lead inhibition of spontaneous GVBD. And, similarly to Pb2+, the inhibition of PKC by calphostin C prevented HX to maintain the meiotic arrest whereas its activation by PMA inhibited spontaneous GVBD. No significant differences in the effects of Pb(NO3)2 on the oocytes were observed whatever the cumulus cells were present or absent. Moreover, lead did not seem to affect the metaphase plate formation. We concluded that Pb2+ may disturb the control of oocyte meiosis at least in part through its ability to interfere with the PKC pathway in taking place of Ca2+ ions.

Animals↗
PubMed2006

Transjugular liver biopsy: prospective evaluation of the angle formed between the hepatic veins and the vena cava main axis and modification of a semi-automated biopsy device in cases of an unfavorable angle.

In cases of transjugular liver biopsies, the venous angle formed between the chosen hepatic vein and the vena cava main axis in a frontal plane can be large, leading to technical difficulties. In a prospective study including 139 consecutive patients who underwent transjugular liver biopsy using the Quick-Core biopsy set, the mean venous angle was equal to 49.6 degrees. For 21.1% of the patients, two attempts at hepatic venous catheterization failed because the venous angle was too large, with a mean of 69.7 degrees. In all of these patients, manual reshaping of the distal curvature of the stiffening metallic cannula, by forming a new mean angle equal to 48 degrees , allowed successful completion of the procedure in less than 10 min.

Adult↗
PubMed2005

[Management of postpartum haemorrhage].

Today, postpartum hemorrhage remains a leading cause of maternal morbidity and mortality. Medical treatment, various surgical procedures and/or uterine artery embolisation have considerably reduced the risk of hysterectomy. It is important to identify the different risk factors of hemorrhage after delivery and to take the precautions to avoid it. A clear strategy defined by the obstetrical team is essential to decrease the delay in the management of this complication in order to increase the chances of a successful treatment.

Algorithms↗
PubMed2005

[Rupture of hepatic focal nodular hyperplasia. About two cases].

The diagnostics of focal nodular hyperplasia is reached through the use of imaging. When the diagnostic is certain, surgical abstention is the rule. Nevertheless, we were confronted with two cases of a rare complication; that of intraperitoneal rupture. In this situation, we suggest to first do an arteriography to control the bleeding, then to perform surgery when the patient has reached hemodynamic stability. Spontaneous rupture as a complication of benign nodular hyperplasia remains a rare event and only five cases were reported in litterature.

Adult↗
PubMed2005

[Radiofrequency tumor ablation: from the liver to the lung passing by the kidney].

Tumor ablation using radiofrequency technique is an interventional radiology method for the treatment of liver renal or pulmonary tumors. The size of the lesion is the limiting factor of this technique. Tumors below 3 cm are treated with a 90% efficacy in one session. Complications are variable according to the organ treated.

Catheter Ablation↗
PubMed2005

[Non invasive multidetector CT angiography of coronary arteries: when and how should I do?].

Recent advances in multi-detector computed tomography technology offer a reliable tool for coronary arteries visualization and atherosclerotic plaque assessment. The objective of this article is to describe the principle of coronary angiography using multi-detector computed tomography, review the current diagnostic performances and help the reader to understand current applications and future challenges of multi-detector computed tomography in coronary artery disease diagnosis and management.

Coronary Angiography↗
PubMed2005

[Complications of liver cirrhosis: oesophageal varices, ascites and hepato-cellular carcinoma].

The principal treatment for bleeding oesophageal varices is endoscopic ligation. Non-cardioselective beta-blockers are the gold-standard of primary prophylaxis. The principal treatment for ascites is a salt-free diet and diuretics, mainly spironolactone, if necessary associated with a loop diuretic. In refractory ascites, paracentesis or installation of a transjugular intrahepatic portosystemic shunt (TIPS) are two possible treatment options. Cirrhosis patients are at higher risk of developing hepato-cellular carcinoma. Surgery is only possible in a small number of cases. Percutaneous destruction techniques have nearly the same survival rate as that obtained by surgery and should be proposed to patients where surgery is not an option.

Adrenergic beta-Antagonists↗
PubMed2004

Influence of detector collimation on SNR in four different MDCT scanners using a reconstructed slice thickness of 5 mm.

The purpose of this paper is to compare the influence of detector collimation on the signal-to-noise ratio (SNR) for a 5.0 mm reconstructed slice thickness for four multi-detector row CT (MDCT) units. SNRs were measured on Catphan test phantom images from four MDCT units: a GE LightSpeed QX/I, a Marconi MX 8000, a Toshiba Aquilion and a Siemens Volume Zoom. Five-millimetre-thick reconstructed slices were obtained from acquisitions performed using detector collimations of 2.0-2.5 mm and 5.0 mm, 120 kV, a 360 degrees tube rotation time of 0.5 s, a wide range of mA and pitch values in the range of 0.75-0.85 and 1.25-1.5. For each set of acquisition parameters, a Wiener spectrum was also calculated. Statistical differences in SNR for the different acquisition parameters were evaluated using a Student's t-test (P<0.05). The influence of detector collimation on the SNR for a 5.0-mm reconstructed slice thickness is different for different MDCT scanners. At pitch values lower than unity, the use of a small detector collimation to produce 5.0-mm thick slices is beneficial for one unit and detrimental for another. At pitch values higher than unity, using a small detector collimation is beneficial for two units. One manufacturer uses different reconstruction filters when switching from a 2.5- to a 5.0-mm detector collimation. For a comparable reconstructed slice thickness, using a smaller detector collimation does not always reduce image noise. Thus, the impact of the detector collimation on image noise should be determined by standard deviation calculations, and also by assessing the power spectra of the noise.

Artifacts↗
PubMed2004

[Value of CT in small-bowel obstruction].

Small bowel obstruction is a leading cause of admission in surgical and emergency units. During the last two decades, the classical philosophy of "never let the sun set or rise on small-bowel obstruction" has been succeeded by a new management based especially on the cause and the severity of the obstruction. It most often allows a correct choice between medical therapy and surgery using laparotomy or laparoscopy. This changing attitude is still in progress and is mainly related to the high accuracy of computed tomography. This review will discuss the semiology and value of computed tomography compared with clinical examination and other imaging modalities.

Humans↗
PubMed2002

Traumatic injuries: imaging of pelvic fractures.

Pelvic trauma includes a great variety of very polymorphous lesions, differing from each other by their anatomical aspect, their context and therapeutic implication: In order to be efficient, the radiologist first has to know diagnostic value of each radiological technique, in order to suggest the investigation strategy appropriate to any clinical situation. Then, he must be able to accurately describe fractures and to include them into a classification in agreement with the clinician. Pelvic fractures form a polymorphous group. In the isolated acetabular fractures, function is mainly at stake. Radiological assessment relies upon good-quality plain films completed by CT imaging in fine slices with multiplanar reconstruction. Letournel's classification remains the reference standard. Management consists mainly of re-establishing a joint congruence to prevent early coxarthrosis. Pelvic fractures often occur in violent trauma and are associated with visceral lesions, putting vital prognosis at stake. Radiological assessment must be included in multidisciplinary management and CT imaging stands for the most complete and least time-consuming device, allowing for investigation of both visceral and osseous lesions. In case of hemodynamic shock, external fracture stabilization and embolization of pelvic bleeding are preponderant. Tile/Association for Osteosynthesis classification is the most used presently. It allows good description of mechanisms and lesions and more adapted management.

Fractures, Bone↗
PubMed2002

[Acute clinical pancreatitis following selective transcatheter arterial chemoembolization of hepatocellular carcinoma].

Acute pancreatitis can complicate non-selective transcatheter arterial embolization of hepatocellular carcinoma with an incidence ranging from 1,7% (acute clinical pancreatitis) to 40% (biological pancreatitis). This complication is thought to be related to embolization of extrahepatic arterial collaterals. We report herein a case of acute clinical pancreatitis developing within 24 hours after a second course of selective transcatheter arterial chemo-embolization into the proper hepatic artery. Neither anatomical arterial variation nor particular risk factor for acute pancreatitis could be identified. This complication is unusual after selective arterial embolization. Because it may clinically mimick a postembolization syndrome, dosage of serum pancreatic enzymes should be performed systematically in case of abdominal pain following chemoembolization.

Acute Disease↗
PubMed2002

Gene transfer of CD154 and IL12 cDNA induces an anti-leukemic immunity in a murine model of acute leukemia.

IL12 is an essential cytokine for the generation of T helper 1 response, natural killer (NK) cells and cytotoxic T lymphocyte (CTL) stimulation. CD154 triggers CD40 on antigen-presenting cells, thus inducing antigen presentation to the immune system and production of IL12. As IL12 and CD154 share several pathways mediating immune response, we investigated in an aggressive murine model of acute leukemia the relative antileukemic efficiency of IL12, CD154 and IL12 + CD154 gene transfer. Live leukemic cells transduced by IL12, CD154, and IL12 + CD154 showed reduced leukemogenicity but CD154 protective effect was reduced when 10(6) leukemic cells were injected. Vaccines with lethally irradiated IL12-transduced cells were able to cure mice previously injected with 10(4) leukemic cells and adoptive transfer of IL12-induced antileukemic immunity protected recipient mice. NK cytotoxicity was enhanced in mice vaccinated with leukemic cells transduced by IL12, CD154, and CD154 + IL12. IL12 transduced cells induced IFN-gamma mRNA in CD4(+) and CD8(+) T cells isolated from the spleen of vaccinated animals, however, in vivo depletion experiments showed that IL12 vaccine effect was CD4(+) but not CD8(+) T cell dependent. We conclude that IL12 gene is a more potent candidate than CD154 for gene therapy of acute leukemia.

Acute Disease↗
PubMed2002

[Surgical anatomy of the liver: what you need to know].

A precise knowledge of arterial, portal, hepatic and biliary anatomical variations is mandatory when a liver surgery is planned. However, only certain variations must be searched when a precise intervention is planned. The main liver resection and biliary interventions will be precised. Related anatomical variations will be precised.

Cholecystectomy↗