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A Denys

Publications and source records attributed to A Denys.

At least 91 records · Page 5Linked to original sources
PubMed1994

Ureteral stents: exchange under fluoroscopic control as an effective alternative to cystoscopy.

From September 1991 to February 1993, in 83 patients (74 women and nine men, aged 24-86 years), 166 double-J ureteral stents (initially placed to treat fistulas or stenoses located within the inferior third of the ureter) were exchanged during 127 procedures. Stents were extracted from the bladder through the urethra under fluoroscopic monitoring by using a lasso made of a 0.018-inch guide wire and a 7-F catheter. Then a new stent was placed over a 0.035-inch guide wire that had been previously coiled in the renal pelvis. Exchange was successful in 161 (97%) of 165 stents.

Adult↗
PubMed1994

Hepatic tumors: detection and characterization at 1-T MR imaging enhanced with AMI-25.

PURPOSE: To evaluate the ability of magnetic resonance (MR) imaging enhanced with AMI-25 to depict and characterize hepatic tumors. MATERIALS AND METHODS: Sixty-four patients (41 men and 23 women, aged 24-65 years [mean, 55 years]) underwent 1-T MR imaging: 22 had metastatic disease; 10, hepatocellular carcinoma; seven, hemangioma; three, focal nodular hyperplasia; three, gallbladder adenocarcinoma; two, lymphoma; one, adenoma; and 16, no tumor. Pre- and postcontrast images (alone and in combination) were analyzed by three independent radiologists. Receiver operating characteristic curves were constructed to compare tumor characterization. RESULTS: Signal intensity was decreased in all benign tumors but not in malignant tumors. The number of tumors depicted (nonenhanced images, 657 tumors; enhanced, 753; and combined, 760) was not statistically different. Receiver operating characteristic curves did not show improved characterization with AMI-25. CONCLUSION: AMI-25 does not improve depiction of hepatic tumors. Although characterization of hepatic tumors was not improved with AMI-25, uptake of AMI-25 seems specific for hepatic tumors at MR imaging.

Carcinoma, Hepatocellular↗
PubMed1994

[Effect of subinhibitory doses of some antibiotics on bacteria in vitro].

The study was aimed at observation of influence of subinhibitory doses of selected beta-lactam antibiotics (cefuroxime, ceftazidime, thienamycin) and of ciprofloxacin on morphology and physiology of S. aureus and E. coli. The bacteria were subjected to action of these antibiotics in various subinhibitory concentrations in fluid Mueller-Hinton medium at 37 degrees C for 18 hours, and morphological changes in bacterial cells were observed in light and electronic microscope. In case of E. coli changes appeared as presence of elongated forms, while S. aureus formed giant cells with changes in staining. It was found that intensity of these morphological changes was proportional to concentrations of antibiotics. For determination of influence of tested antibiotics on growth of bacteria they were cultured in the fluid Mueller-Hinton medium containing antibiotics in concentrations of 4, 1 1/4 MIC. The culture lasted for 6 hours, and number of bacterial cells in 1 ml of the medium was periodically determined. Distinct inhibition of growth of bacterial cells was proportional to the used concentrations of antibiotics. Described in this paper morphological changes of bacteria found confirmation in change of their physiology expressed as inhibition of bacterial cell growth.

Anti-Bacterial Agents↗
PubMed1993

Amygdala atrophy in Alzheimer's disease. An in vivo magnetic resonance imaging study.

OBJECTIVES: To study the ability of magnetic resonance imaging to measure the volume of the amygdala and detect amygdala atrophy in patients with early Alzheimer's disease. DESIGN: Prospective case-control study and "blind" measurements. SETTING: Subjects were ambulatory outpatients selected from an institutional practice in Paris, France. PATIENTS: We studied 11 patients with probable Alzheimer's disease according to National Institute of Neurologic and Communicative Disorders and Stroke/Alzheimer's Disease and Related Disorders Association (NINCDS-ADRDA) and Consortium to Establish a Registry for Alzheimer's Disease (CERAD) inclusion and exclusion criteria, as well as six age-matched control subjects. INTERVENTION: None. MAIN OUTCOME MEASURE: A 1.5-T magnetic resonance imager was used to acquire the images. Two neuroradiologists independently and blindly measured the volume of the right and left amygdalas on high-resolution contiguous slices. In addition, other cerebral structures, ie, the sylvian fissures, temporal lobes, lateral and third ventricles, corpus callosum, and hippocampal formation, were measured on a single slice. RESULTS: The values obtained by the two observers correlated highly (r = .90), and interrater variability was 13%. The Alzheimer's disease group showed significant (33%, P < .0001) atrophy of the amygdala when compared with the control group. The other structures showed less variation. CONCLUSION: Significant amygdala atrophy can be detected in vivo in patients with early Alzheimer's disease by means of standard magnetic resonance imaging. This technique may be useful in the early diagnosis of Alzheimer's disease.

Aged↗
PubMed1993

Renal cell carcinoma containing fat: demonstration with CT.

It is widely believed that demonstration of fat within a well-marginated renal tumor at computed tomography (CT) is highly suggestive of angiomyolipoma and can rule out renal cell carcinoma. The authors describe a patient in whom CT demonstrated a solid mass containing calcifications and small amounts of fat. Renal cell carcinoma was diagnosed at pathologic examination. The carcinoma had tubular and papillary architectural configurations associated with areas of osseous metaplasia located in the fibrous stroma of the tumor. Renal cell carcinoma should be considered in the differential diagnosis of well-marginated lipomatous renal tumors when intratumoral calcifications are identified at CT. Such calcified, fat-containing renal tumors must be evaluated with surgical exploration and treated as any other indeterminate renal tumors.

Adipose Tissue↗
PubMed1993

[Role of MRI in the diagnosis of kidney cancer].

The recent technical developments in magnetic resonance imaging (MRI) and the use of paramagnetic contrast media (gadolinium compounds) have considerably improved the performances of MRI for the detection and characterization of renal tumors. MRI does not have specific merits for the diagnosis of the typical form of cancer, nor for the detection of small kidney tumors, both being mainly based on computed tomography (CT). On the other hand, it can be used for the diagnosis of atypical forms of cancers (small, hypovascular, cystic or hemorrhagic cancers) which raise problems of differential diagnosis with some pseudotumoral lesions, complex cysts and benign tumors. Its complementarity to CT for the characterization of an atypical mass results from the signal information it provides, from a better contrast resolution, and from the possibility to make sections in all planes of space. Except for angiomyolipoma, which has a fatty content, there is no really specific MR criterion as present to evidence benign renal tumors. Concerning regional extension, CT remains the primary technique of choice, as it allows studying the limits of the tumor, the renal compartment ans its walls, the renal vein and the inferior vena cava, the neighboring organs and the contralateral kidney all together. Its findings allow defining the indications of MRI, which, as a complementary exploration, is often decisive to assess venous invasion.

Diagnosis, Differential↗
PubMed1992

[Imaging of renal cancer in adults].

In its typical form renal carcinoma shows at imaging as a solid, heterogeneous and vascularized mass deforming the kidney; its CT scan appearance is usually very suggestive. Atypical forms (small or cystic carcinomas, large carcinomas with exorenal extension, haemorrhagic carcinomas) mainly raise problems of characterization; the lesional image is always suspicious at CT or combined US, CT and MRI examinations. The detection of small tumours primarily rests on CT with contrast injection, a technique which is more sensitive (94%) than all other techniques. Among non-tumoral lesions which may look like renal carcinomas, some pseudotumoral inflammatory lesions and suspicious atypical cysts often require histological examination. With the exception of angiomyolipoma with its fat content detectable at CT or MRI, there is no truly specific criterion to differentiate benign tumour from cancer. The diagnosis of renal carcinoma extension primarily rests on MRI. In a number of cases the results are so inadequate for the study of renal veins and caval vein that a complementary exploration of these veins by Doppler ultrasonography or MRI must be requested.

Adult↗
PubMed1992

Magnetic resonance imaging to monitor pathology of caudate-putamen after excitotoxin-induced neuronal loss in the nonhuman primate brain.

We used MR imaging to locate and monitor in vivo the pathological events taking place 2 to 4 weeks after unilateral striatal injections of ibotenic acid (IA) in the Papio papio baboon. As early as 2 weeks after IA injections, excitotoxic lesions in the caudate and the putamen were directly visualized on T1-weighted images as small areas of low signal intensity. On T2-weighted images, the lesion sites were visualized as areas of high-intensity signal, spreading over larger areas than the corresponding regions in T1-weighted images. These alterations of T2-values in the lesioned striatum persisted 4 weeks after surgery. However, as the striatal degeneration progressed from 2 to 4 weeks after lesion, the size of the areas of high signal intensity on T2-weighted images decreased, whereas the same regions appeared essentially unmodified on T1-weighted images. A marked enlargement of the ipsilateral lateral ventricle (a characteristic of excitotoxic striatal lesions) could be detected 4 weeks after surgery, on both axial T1- and T2-weighted images. Comparisons of MR images with postmortem anatomical data indicated that areas of increased T1 values corresponded to regions of severe neuronal depletion (a direct result of the excitotoxic lesion), whereas areas of increased T2 values corresponded to regions of increased content in astrocytes and ferritin and probably in the early period following lesion (2 weeks) to a superimposed edema.

Animals↗
PubMed1992

Gd-DOTA-enhanced MR imaging and color Doppler US of renal allograft necrosis.

In 21 recipients of renal transplants suspected of allograft necrosis, the authors correlated the results of imaging to pathologic and histologic data in order to describe the magnetic resonance (MR) imaging and color Doppler ultrasonographic (US) characteristics of infarction. All patients underwent MR imaging performed with and without gadolinium tetraazacyclododecanetetraacetic acid (DOTA) and color Doppler US. Nonenhanced T1-weighted images showed no obvious changes, whereas nonenhanced T2-weighted images demonstrated a slight increase in signal intensity in areas of ischemic necrosis and low or heterogeneous signal intensity in areas of hemorrhagic necrosis. Gd-DOTA-enhanced MR images showed no contrast material uptake in infarcted areas. Color Doppler US characteristics of infarction included absence of Doppler signal and alteration of the cortical echogenic structure, particularly in cases of ischemic necrosis. Color Doppler US allows measurement of vascular resistance and assessment of intrarenal vasculature and the renal pedicle. Gd-DOTA-enhanced MR imaging is useful in confirming the diagnosis of infarction and provides an accurate evaluation of the extent of the infarct.

Adult↗
PubMed1992

[Effect of TFX (Polfa) on the course of experimental bacterial infections in mice treated with ciprofloxacin, amikacin and cefoperazone].

The effect of TFX-Polfa administered alone or with three antibiotics on the survival time in mice infected with E.coli and S.aureus was estimated. TFX has been administered 48, 24, 2 hours before and 24, 48 and 72 hours after infection, in doses of 10 mg/kg of body weight. Ciprobay has been administered 2 hours after infection, and every 24 hours during the experiment in dose of 15, 7.5 and 3.75 mg/kg of body weight. Amikin has been used in doses of 7.5, 3.75 and 1.87 mg/kg of body weight, Cefobid in doses of 30, 15 and 7.5 mg/kg of body weight. The antibiotics have been administered 2 hours after infection and every 12 hours to the end of experiment. Animals have been observed 10 days after infection. The positive effect of TFX on the survival time in mice infected with E.coli has been observed, but this preparation has given a little effect on the tested parameter in mice infected with S.aureus. Best antibacterial effect of Ciprobay and Amikin has been observed after administration of clinical doses. However, simultaneous therapy with TFX and tested antibiotics resulted in various (positive and negative) effects on the survival time during 10 days of observation.

Amikacin↗
PubMed1992

[Role of MRI in the diagnosis of cancer of the kidney].

The recent technical developments in magnetic resonance imaging (MRI) and the use of paramagnetic contrast media (gadolinium compounds) have considerably improved the performances of MRI for the detection and characterization of renal tumors. MRI does not have specific merits for the diagnosis of the typical form of cancer, nor for the detection of small kidney tumors, both being mainly based on computed tomography (CT). On the other hand, it can be used for the diagnosis of atypical forms of cancers (small, hypovascular, cystic or hemorrhagic cancers) which raise problems of differential diagnosis with some pseudotumoral lesions, complex cysts and benign tumors. Its complementarity to CT for the characterization of an atypical mass results from the signal information it provides, from a better contrast resolution, and from the possibility to make sections in all planes of space. Except for angiomyolipoma, which has a fatty content, there is no really specific MR criterion as present to evidence benign renal tumors. Concerning regional extension, CT remains the primary technique of choice, as it allows studying the limits of the tumor, the renal compartment and its walls, the renal vein and the inferior vena cava, the neighboring organs and the contralateral kidney all together. Its findings allow defining the indications of MRI, which, as a complementary exploration, is often decisive to assess venous invasion.

Adenocarcinoma↗
PubMed1991

[Color and pulsed Doppler of renal masses. Angiographic and anatomo-pathological correlation].

We report the results of a prospective study about the detection of tumoral neovascularization, the renal vein involvement and the characterization of renal tumors by color and pulsed doppler. Twenty-six renal tumors including 19 renal carcinomas and 7 benign tumors (2 angiomyolipomas, 2 oncocytomas, 2 complex cysts and one adenoma) were prospectively explored. Benign cysts were excluded from the study. The results were correlated to pathologic (24/26) and angiographic datas (24/26). Doppler ultrasonography seems to be an accurate method for the detection of a neovascularization (19 true-positives/19 vascularised tumors, no false-positive) but pulsed doppler (no false-negative) is more sensitive than color doppler imaging (3 false-negatives), the results of color doppler were improved by using a new software for the color detection of very low flow. Spectral analysis found 3 different types of doppler curves inside the masses, but all of them were observed in benign and malignant tumors. We did not find any correlation between the size of the tumor and the peak systolic velocity. The specificity of Doppler regarding the renal vein and inferior vena cava involvement seems to be good (no false-positive). But as, in our series, we do not have any case of main renal vein involvement, the sensitivity of this technique cannot be assessed.

Adult↗
PubMed1991

[Conservative surgery of kidney cancer. Ex vivo surgery with immediate magnetic resonance imaging].

In addition to the technical difficulties arising when the tumor is located in the centre of the kidney, one of the stumbling blocks of conservative partial surgery of the parenchyma is the risk of leaving a second tumoral focus in place. In these cases, we propose an ex vivo operation associated with an intraoperative examination of the isolated kidney with nuclear magnetic resonance.

Anastomosis, Surgical↗
PubMed1991

[The effect of tienamycin on selected cellular immunologic parameters in mice during the course of viral-bacterial infections of the respiratory system].

The effect of tienamycin on selected parameters of the immunological system in mice infected with the influenza virus and Staphylococcus aureus was studied. Tienamycin was administered 24 hours, 2 hours prior the infection and 2 hours after the infection (model I), 24 hours and 48 hours after infecting the mice (model II). The authors analysed phagocytosis, bactericidal activity of peritoneal exudate cells and the LIF release induced by the staphylococcus antigen and the viral antigen by the spleen mice leukocytes. The authors found that the antibiotic given to non-infected mice inhibited phagocytosis of staphylococci by the peritoneal exudate cells. In mice that were infected a positive effect of the antibiotic on all studied parameters. Administering the antibiotic before infecting the mice produced an even better effect.

Animals↗