Search PubMed⌕ Search

Biomedical subjects

J F Moreau

Publications and source records attributed to J F Moreau.

At least 109 records · Page 6Linked to original sources
PubMed1994

[Color Doppler ultrasonography in urology].

Due to the development of the duplex mode, combining ultrasound images with Doppler recording, and especially the development of flow colour coding. Doppler is now increasingly used to investigate the kidney and male genital tract. It is now the technique of choice in the initial diagnosis of certain renal diseases: primary renal vein thrombosis, iatrogenic and malformative arteriovenous anomalies, vascular complications of renal transplantation, and for examination of the scrotal contents in a context of acute scrotum or investigation of the cavernosal arteries in the case of erection disorders. It allows a rapid diagnosis and guides the subsequent radiological assessment. Doppler can also provide useful or even essential additional information in the case of a known abnormality such as renal cancer, in which it defines the venous extension when CT scan is technically insufficient. In certain fields, such as diagnosis of renovascular hypertension or exploration of the prostate, the place of Doppler is still poorly defined and remains controversial, except in a few specialised centres equipped with sophisticated apparatuses used by experienced operators. After briefly reviewing Doppler techniques and the basic steps in interpretation, the authors define the contribution and limitations of colour Doppler in the investigation of the urinary tract and male genital tract. Normal appearances and the results of Doppler-ultrasound in nephrourological disease are illustrated.

Genital Diseases, Male↗
PubMed1994

[Positioning of hemodialysis catheters after locating the internal jugular vein by echo-Doppler].

Despite significant progress, vascular access remains a major concern for nephrologists. For the last 6 years we have used as temporary vascular access silastic twin catheters implanted into the internal jugular vein based on Canaud's method. We have developed in 15 patients an ultrasound-guided method using an ultrasonic Doppler to improve access to the internal jugular vein, prior to its catheterization. Ultrasound assistance was provided by a 5MHz mechanical sectorscanning transducer (Toshiba 270A). The internal jugular vein and carotid artery were visualized. The skin overlying the internal jugular vein was marked with indelebile ink. The internal jugular vein was cannulated successfully in 14 patients. The use of ultrasound guidance to cannulate the internal jugular vein improves success, and reduces complications. This method is recommended in patients with distorted cervical or subclavicular anatomic characteristics, or with bleeding tendency.

Catheterization, Central Venous↗
PubMed1994

[Femoral arteriovenous fistulas after vascular puncture for hemodialysis].

From 1978 to 1991 we observed 10 patients who developed femoral arteriovenous fistula after venous puncture for hemodialysis. The fistula most often appeared after several punctures, but 3 developed after a single puncture. Diagnosis was made on the basis of local observation and auscultation of the vessel (bruit + thrill n = 10, hematoma n = 4, pulsatile mass n = 1). Two patients had arteriography and 2 had echo-doppler. Arteriography was not required for diagnosis (since clinical signs were sufficient), or for treatment, since echo-doppler and surgery indicated the location of the fistula. Five patients underwent surgery. In all cases, continuity of the main vessels of the lower member was maintained or reestablished during surgery. Surgery is mandatory for high flow rate. Such fistulas cannot be used and can cause cardiac failure in patient with another fistula for hemodialysis. Surgery should not be undertaken too early because of the possibility of spontaneous clotting (particularity if echo-doppler shows low flow rate), and to allow organization of the lesions and easier dissection. Auscultation of the vessel should be a routine procedure after any femoral vein puncture in order that this complication not be overlooked.

Adult↗
PubMed1994

[Tunneled double femoral catheters: emergency vascular access for hemodialysis].

Transient vascular access for hemodialysis is a daily problem in nephrology. Internal jugular twin catheters using Canaud's technique is the method of reference, which we have applied since 1987. In 3 cases where the internal jugular route was impraticable, twin catheters via the femoral route were used. The catheter was placed by percutaneous route, at the bedside, in rigorous aseptic conditions and with local anesthesia. The catheter emerge at mid-thigh. Mean placement time was 45 mn. The ideal site for distal end of the catheters is in the inferior vena cava. No traumatic complication occurred during placement. No infectious episode was observed. All the catheters that were removed were sterile in culture. No thrombosis of femoral, iliac or inferior cava veins were observed by echodoppler after removal of the catheters. In conclusion, twin femoral catheters are a good alternative when jugular access is impossible or contraindicated.

Adult↗
PubMed1994

[Imaging of vascular complications of renal transplantation].

The accuracy of color Doppler US (CDUS) for the detection of main renal transplant artery stenoses is excellent (Se 92%; SP 99%). Whereas the sensitivity of CDUS is still unsatisfactory for the detection of arterial branch stenosis (Se 70%), it has become higher than previously reported because of the ability of color flow images to identify hemodynamic changes at the site of stenosis and focal downstream repercussions in the case of tight stenosis. Color Doppler US is a valuable method in the detection of segmental infarction or large areas of cortical necrosis. However, small superficial cortical perfusion defects are usually undetectable by color Doppler. Contrast-enhanced MRI appears to be more accurate than color Doppler US; it is useful in confirming the diagnosis of infarction and detecting small infarcts missed by color Doppler US, and provides an accurate evaluation of the extent of the infarct; Spectral features (reflux during the whole diastole) obtained from renal arteries in case of acute renal vein thrombosis are suggestive but not specific since they can be observed in the case of severe acute rejection with cortical necrosis. Such findings associated with a lack of venous Doppler signals in the whole kidney are highly suggestive of renal transplant vein thrombosis. Post-biopsy arteriovenous fistulas and false arterial aneurysms are accurately detected by color Doppler Imaging. Color Doppler appears to be the primary Imaging modality for early detection of renal allograft vascular complications.(ABSTRACT TRUNCATED AT 250 WORDS)

Aneurysm↗
PubMed1994

[MRI in cancer of the prostate with T1-weighted sequences using fat suppression and injection of gadolinium].

The assessment of tumor extension in 20 patients with cancers of the prostate at a clinical stage A or B included MRI with a body coil before prostatectomy. Transverse and coronal T1-weighted sections with injections of gadopentate dimeglumine (gadolinium) and fat suppression were systematically taken to assess the vascularity of the various regions of the prostate and of the cancer, as well as the merits of such sequences for the assessment of extension. The normal, poorly vascularized peripheral area is only slightly enhanced by injection, while the transition area, which is most often hyperplastic in the age group studied, enhances heterogeneously with contrast. All cancers enhance after injection. In the assessment of extension, the major merit of gadolinium is that it allows exploration both of the vesiculodeferential junction on coronal sections and of the structure of the seminal vesicles. Thus a normal junction allows ruling out macroscopic invasion of the vesicles. In addition, gadolinium allows correcting false positive MRI findings when the areolar structure of the vesicles is preserved. Gadolinium does not provide additional evidence of extension through the capsule in comparison with T2-weighted sequences. On a whole, in our series, MRI with a body coil, associated T2-weighted sequences and T1-weighted sequences after gadolinium injection and fat suppression, has 58% sensitivity and 100% specificity for the diagnosis of stage C cancers.

Aged↗
PubMed1993

The effects of cyclosporine on HILDA/LIF gene expression in human T cells.

We examined the effect of cyclosporine on HILDA/LIF gene expression in alloreactive human T lymphocyte clones (ATLCs) 2B11 and 2F7 obtained from cells infiltrating a rejected human kidney graft. Both ATLCs were stimulated either by the specific antigen or by PMA + calcium ionophore in the presence of various concentrations of CsA (10-500 ng/ml). Inhibition of HILDA/LIF gene expression was analyzed at the protein level using a proliferative assay on the HILDA/LIF-dependent Da-1a cell line and by RNA blotting using a specific probe. Without CsA, the kinetics of mRNA accumulation for both ATLCs peaked at 5 and 10 hr, respectively, after mitogenic and antigenic stimulations. HILDA/LIF activity peaked at 24 and 72 hr, respectively, after mitogenic and antigenic stimulation in supernatants from both ATLCs and decreased thereafter. Subsequent experiments with CsA were thus performed at these time points. Our results show that HILDA/LIF mRNA accumulation and protein secretion in 2B11 and 2F7 clones were strongly inhibited in a dose-dependent manner by CsA, in both stimulation conditions. Maximal inhibition of HILDA/LIF transcripts and protein secretion (60-90%) was observed within the range of 75-500 ng/ml CsA.

Cyclosporine↗
PubMed1993

HILDA/LIF, G.CSF, IL-1 beta, IL-6, and TNF alpha production during acute rejection of human kidney allografts.

HILDA/LIF, a recently described glycoprotein, has been characterized from supernatants of alloreactive T cell clones (CD4 and CD8) extracted from a human rejected kidney graft. This suggests a possible role for HILDA/LIF in the rejection process. In order to further investigate this possible role and the role of other cytokines in allograft rejection, we tested HILDA/LIF, G.CSF, IL-6, TNF alpha, and IL-1 beta in supernatants of cultured mononucleated cells from patients during rejection and from stable grafted patients. In addition, we also tested HILDA/LIF in urine of the same patients. No significant differences were directly observed in the production of HILDA/LIF, TNF alpha, and IL-1 beta in supernatants from mononucleated cells between rejecting and stable patients. However, when antibodies were used to block the TNF alpha and the IL-1 beta receptors, an increase of both cytokines was detected in cells from rejecting patients suggesting that an over-expression of both receptors and cytokines occurred during rejection. A significant increase was also observed for both G.CSF and IL-6 during the rejection compared to stable grafts. In addition, HILDA/LIF was detected in urine of patients during rejection and not in urine of stable patients, suggesting that this cytokine may indeed play a role in rejection.

Antibodies↗
PubMed1993

Immunogenicity of HILDA/LIF either in a soluble or in a membrane anchored form expressed in vivo by recombinant vaccinia viruses.

Insertion of various cDNAs in the genome of the vaccinia virus (VV) enables the in vivo and in vitro study of the functional role and/or the immunogenicity of the virally encoded recombinant proteins. We have prepared a recombinant VV expressing the cDNA of the human cytokine HILDA/LIF (human interleukin for DA cells/leukaemia inhibitory factor), and used this virus to immunize mice against this protein, which is very homologous to its murine counterpart (approximately 80% homology). We also constructed and expressed by the same system a chimeric gene encoding the HILDA/LIF protein fused to the 37 COOH-terminal amino-acids of the human decay accelerating factor (DAF). This sequence proved to be sufficient for the targeting of the fusion protein to the cell membrane, where it is linked to the phosphatidylinositols. Both recombinant VVs induced cytokine-specific antibodies in mice as analysed with an ELISA where the recombinant HILDA/LIF was plastic-coated and a cytofluorometric assay where the LIF-DAF molecule was present at the cell surface of stably transfected P815. In the latter case HILDA/LIF remained biologically active suggesting that it was expressed in its native form. The LIF-DAF fusion protein was found to exhibit a better capacity to elicit an antibody response against the native form of the cytokine as detected in cytofluorometric assays. Whatever the recombinant virus used to immunize the mice, the MoAbs obtained were positive either in the ELISA or in the cytofluorometric assays but one, which suggested that the plastic coating induced a conformational change of HILDA/LIF.

Animals↗
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

[Radiological exploration of hematuria].

Hematuria is defined as the presence of blood in urine. Its site of origin can be in any point of the urinary tract. Its discovery leads to clinical, biological and radiological investigations. The causes of hematuria are dominated, in terms of frequency, by urinary infection and lithiasis. The risk of associated lesions, especially of a tumor, must lead to regarding them as excluding diagnoses. Besides the so-called "medical" hematurias of glomerular origin (hematuria with proteinuria and cylinder casts) and hematurias occurring during a first episode of cystitis in women, the radiological exploration of "surgical" hematuria is systematic and always begins with an IVP. When the IVP is normal, a cystoscopy is most often made. The other radiological examinations (CT, Doppler ultrasound) are performed only according to the findings of IVP and cystoscopy. Arteriography combined with renal phlebography is indicated if the assessment is negative in case of recurrent hematuria or of massive hematuria. It is mainly aimed at detecting a vascular malformation. When this exploration is completed, an etiology is found is about 90% of all cases.

Female↗
PubMed1993

[Renal Doppler ultrasonography in the diagnosis of acute obstructions of the upper urinary tract].

A comparative study of the resistivity indices (RI) obtained in both kidneys has been carried out in 30 controls and 60 patients with suspected unilateral acute obstruction of the upper urinary tract. Doppler findings (difference in the mean RI of both kidneys, delta RI) in the pathologic population have been systematically correlated to the data yielded by intravenous pyelography (IVP). In the control population delta RI was always < or = 0.03 (mean delta RI = 0.01, SD = 0.01). Considering that an increase in delta RI > or = 0.05 (> mean RI + 3 SD) is significant, 93% sensitivity and 100% specificity are obtained for the diagnosis of unilateral acute obstruction. Comparison of the resistivity indices of both kidneys is more specific and more sensitive than the assessment of the index on the obstructed side only; it improves the performance of ultrasonography in the initial diagnosis of acute urinary tract obstruction.

Acute Kidney Injury↗
PubMed1993

Incubation of monocytes with adriamycin increases secretion of hepatocyte stimulating factor for fibrinogen biosynthesis.

This work provides evidence that the production by monocytes of hepatocyte stimulating factor(s) for fibrinogen biosynthesis was dramatically increased when monocytes were exposed to Adriamycin. This effect was related to an increased production of leukaemia inhibiting factor (LIF), a cytokine known to stimulate fibrinogen biosynthesis by hepatic cells. Adriamycin also induces an increase in membrane-associated urokinase on monocytes. These results are consistent with the clinical observation in patients with ovarian cancer that when the CA-125 tumour marker decreases during chemotherapy, an increased level of D-dimer is a marker of good prognosis.

Cells, Cultured↗