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J Le Cloirec

Publications and source records attributed to J Le Cloirec.

16 recordsLinked to original sources
PubMed2001

Role of vagal innervation on intragastric distribution and emptying of liquid and semisolid meals in conscious pigs.

The role of vagal innervation on emptying patterns and intragastric distributions of liquid and semisolid meals is still controversial. We aimed to record these features after dorsal, ventral and truncal vagotomies, using external gamma scintigraphy in conscious pigs in which the dorsal vagus specifically innervates the proximal stomach. Imaging of the stomach was performed for all experimental situations and before surgery using 99mTc-labelled glucose and porridge meals. Emptying of liquids was faster after dorsal vagotomy, whereas it was unchanged after ventral and truncal vagotomies (T1/2 = 57 +/- 8.5, 31 +/- 14.4, 54 +/- 9.1 and 42 +/- 14.9 min for intact, dorsal, ventral and truncal vagotomies, respectively). On the other hand, truncal vagotomy significantly reduced the emptying rate of semisolids whereas dorsal and ventral vagotomies had no significant effect (T1/2 = 96 +/- 7.2, 113 +/- 8.1, 75 +/- 9.9 and 260 +/- 56.6 min for intact, dorsal, ventral and truncal vagotomies). Morphological analysis of the gastric shape confirmed an overdistended proximal stomach after truncal vagotomy only. For semisolids, proximal stomach emptying followed the same emptying pattern as the entire stomach, irrespective of the surgical procedure. We concluded that the proximal stomach is the main control for the emptying of liquids and semisolids. The vagal control of overall gastric emptying for semisolids is probably identical to that modulating the intragastric distribution of the meal.

Animals↗
PubMed2001

Importance of the choice of the collimator for the detection of small lesions in scintimammography: a phantom study.

99mTc methoxyisobutylisonitrile planar scintimammography (SMM) is mostly performed using low-energy high-resolution (LEHR) parallel collimators. We studied whether using a different collimator could improve the detection of small (< 1.5 cm) lesions for which SMM sensitivity is poor. Thirty four breast phantom configurations were considered, either with hot spheres simulating lesions or without any spheres. For each configuration, four planar acquisitions were performed using LEHR, low-energy ultra high-resolution (LEUHR), high-resolution fan-beam (HRFB) and ultra high-resolution fan-beam (UHRFB) collimators. Images corresponding to the 20% and 10% energy windows and to the Jaszczak subtraction were calculated. A database including 156 borderline images was derived. After training, 10 observers scored the images for the presence of a sphere. The performances in sphere detection were studied using receiver operating characteristic (ROC) analysis. For all types of image, the area under the ROC curve was highest with the UHRFB collimator and lowest with either the LEUHR or the HRFB collimator. For the 10% energy window images conventionally used in SMM, the detection sensitivities averaged 91%, 73%, 60% and 55% for the UHRFB, LEHR, HRFB and LEUHR collimators respectively, for the same specificity of 64%. We conclude that detection of small tumours in planar SMM might be significantly improved by using a UHRFB collimator instead of an LEHR collimator.

Breast Neoplasms↗
PubMed2000

Somatostatin receptor in breast cancer and axillary nodes: study with scintigraphy, histopathology and receptor autoradiography.

UNLABELLED: We conducted a prospective analysis of somatostatin receptor scintigraphy using (111)In radiolabeled pentetreotide, a somatostatin analog, in patients with breast cancer in the aim to visualize the primary tumor and axillary or parasternal metastatic extension because some malignant breast tumors express somatostatin receptors (SS-R) in 50%, approximately. An analysis of SS-R was performed by autoradiography. PATIENTS AND METHODS: Thirteen patients with clinically suspected breast tumors (T1, T2), and at least one palpable axillary node (N1) were included. In vivo planar scintigrams were acquired 1, 4, and 24 h after subcutaneous, then after intravenous injections (24 h delay between injections). Improved (111)In-pentetreotide uptake in invaded nodes after subcutaneous injection was hypothesized. Ex vivo scintigrams of surgical specimens were also acquired immediately after tumor resection and axillary dissection. Pathological examination and receptor autoradiography were performed on all surgical specimens. RESULTS: Among 11 pathologically proven malignant tumors (9 ductal and 2 lobular carcinomas), only four were scintigraphically visible although six expressed SS-R receptors in vitro. Among six pathologically proven malignant nodes, four expressed SS-R, including two visualized scintigraphically. Scintigrams acquired after subcutaneous injections were less sensitive than after intravenous injections. There were no false positive. False negatives occurred in cases with small tumors with low-density or heterogeneously distributed SS-R. There was no significant difference by histological type or prognostic factors. CONCLUSION: Somatostatin receptor scintigraphy does not appear to be sensitive enough to evaluate axillary node extension of breast cancer or even to confirm the presence of tumoral tissue, and this whatever the administration route for (111)In-pentetreotide.

Adult↗
PubMed2000

Contribution of 99Tcm-DMSA scintigraphy to aetiological diagnosis in renal transplant recipients with impaired renal function.

Routine 99Tcm-dimercaptosuccinic acid (DMSA) scintigraphy was performed in a series of 24 kidney transplant recipients with impaired renal function. Diagnostic findings on planar and tomoscintigraphic acquisitions obtained 3 and 4 h after the injection of 130-140 MBq 99Tcm-DMSA were compared with the diagnosis established by fine-needle biopsy in 13 patients and by clinical course and other examinations (ultrasonography, bacteriology) in 11 patients. Renal scintigraphy demonstrated segmental defects in patients with rejection (n = 2/6), immunosuppressor nephrotoxicity (n = 2/6), acute pyelonephritis (n = 3/3), renal artery stenosis (n = 1/1) and obstructive lymphocele (n = 1/1). Diffuse lack of uptake was observed in one patient with severe renal failure. The scintigram was normal in 14 patients, including three with lesions histologically compatible with graft rejection or immunosuppressor nephrotoxicity. 99Tcm-DMSA was thus found to contribute little to the differential diagnosis between graft rejection and immunosuppressor nephrotoxicity. However, it may be useful for identifying specific disease states, particularly acute pyelonephritis, seen as well-delimited systematized defects. 99Tcm-DMSA scintigraphy could also be used in late follow-up after pyelonephritis in renal transplant recipients.

Adult↗
PubMed1998

Use of indium-111 pentetreotide somatostatin receptor scintigraphy to detect recurrent thyroid carcinoma in patients without detectable iodine uptake.

We conducted a prospective evaluation of somatostatin receptor scintigraphy (SRS) for the diagnosis of recurrent vesicular or papillary thyroid carcinoma in 16 patients with no detectable iodine uptake. SRS was performed 1, 4 and 24 h after intravenous injection of 137-200 MBq of indium-111 pentetreotide. Results were interpreted in terms of assumed presence of tumoral tissue: there were three true-positives (19%), one false-positive (6%) and 12 false-negatives (75%). The three true-positive patients had multiple lesions visible on computerized tomography. SRS was negative in all patients with a high thyroglobulin level alone. In addition, we analyzed the consequences of interpretative criteria and somatostatin receptor expression variability for SRS positivity as well as the risk of false-positives. We conclude that when iodine uptake cannot be demonstrated in patients with suspected recurrence of differentiated thyroid carcinoma, SRS would not appear to contribute to diagnosis, and that interpretative criteria commonly used for tumours with a high receptor density may be too restrictive for tumours with a low receptor density.

Adult↗
PubMed1995

Per operative localization of a carcinoid tumour of the breast using indium-111 pentetreotide and a nuclear surgical probe.

A 69-year-old woman presented with a single enlarged lymph node in the left axilla. Clinical examination and other investigations, including various imaging methods, failed to reveal the primary tumour. However, indium-111 pentetreotide scan revealed a site of uptake in the anterior region of the left thorax. Peroperative imaging with 111In-pentetreotide confirmed the tumour uptake and use of a nuclear surgical probe allowed precise localization of the tumour, which was completely resected.

Aged↗
PubMed1994

[Radionuclide studies in the surveillance of the renal transplant].

Since Collins et al. first reported in 1963 that ortho-iodohippurate is taken up by the parenchyma, much progress has been made in isotope techniques. Advances have been made in the performance of the gamma cameras and the associated data processing. A major step was the introduction of tracers for studying renal function. More than an imagery technique, scintigraphy is a means of exploring of organ function. Its non-invasiveness and the low patient irradiation allow for repeated use, especially for long term follow ups. It is therefore important to precisely define the role of scintigraphic techniques in the follow up of renal transplantations in coordination with other techniques including echography.

Humans↗
PubMed1993

111Indium-F(ab)'2-NCA 102 monoclonal antibody: in vitro study of a specific agent for the detection of inflammatory foci.

A new antigranulocyte antibody was evaluated in vitro for the detection of inflammatory foci in man. The specificity for polymorphonuclear cells (PMN) of NCA 102, an anti-NCA 95 monoclonal IgG1, was determined with immunohistochemical and cytofluorometrical tests. Its affinity, assessed by Scatchard analysis, was 1.1 x 10(9) L/mol and the number of epitopes per granulocyte reached about 10(5). The biological properties of PMNs incubated with NCA 102 were not inhibited even when coupled with DTPA. A F(ab)'2 fragment was radiolabelled with 111Indium and incubated in the presence of whole blood. More than 65% radioactivity was selectively taken up by the PMN population. These findings indicated that NCA 102 antibody is suitable for sepsis detection.

Animals↗
PubMed1993

Iterative reconstruction methods for nonuniform attenuation distribution in SPECT.

Two iterative methods, a generalization of the Chang method and a projection precorrection, were investigated to determine whether the use of an attenuation map could improve nonuniform attenuation compensation. After a detailed description of the methods, results obtained with simulated and phantom data were compared. This study demonstrates that projection precorrection provides accurate quantification and good image quality as early as the precorrection step, whereas the generalized Chang method requires computation of one more iteration.

Algorithms↗
PubMed1988

[Value of scintigraphy using labelled polynuclears in the diagnosis of infection of a joint prosthesis].

Fifty-three patients with suspected infection of prosthetic joints had Indium-111 granulocyte scintigraphy. Twenty-nine of them had associated technetium-99m phosphate scans. Labelled granulocyte sensitivity was 82% and specificity 100% for the group of 47 patients with suspected late infection. Technetium phosphate sensitivity was 92% and specificity 25%. The main quality of labelled granulocyte scintigraphy is its high specificity: there were no false positives in our series. Its main limitation seems to be that sensitivity is sometimes only moderate: we had 4 false negatives. The probable explanation is the histological characteristics of bone infection: vascular thromboses occur frequently and at an early stage, the inflammatory infiltrate is not very abundant and often has a low granulocyte content. The method is therefore reliable and can be used in situations where diagnosis of periprosthetic infection is difficult with conventional techniques.

Evaluation Studies as Topic↗
PubMed1985

[Detection of intra-abdominal suppuration. Value of scintigraphy with indium-111-labeled autologous polynuclears].

Between February, 1982 and August, 1983, 53 patients with symptoms suggestive of post-operative intra-abdominal abscess were explored by scintigraphy with indium-111 labeled autologous polymorphonuclears. The sensitivity and specificity of this method were both 96%. Scintigraphy of course must be preceded by ultrasonic exploration which is of more delicate interpretation as well as less sensitive (60%) and less specific (84%). The results of scintigraphy avoided an unnecessary laparotomy in more than one-half of the patients.

Abdomen↗
PubMed1984

[Quantification of separate renal function using Tc 99m DTPA and Tc 99m DMSA. Correlations between individual isotopic data and creatinine clearance].

The purpose of this prospective study (30 controls and 100 renal patients) is to compare one to each other the values of renal function measured with: 1--the DTPA 99mTc , 2--the DMSA 99mTc , and 3--the creatinine clearance. After the control values being established, correlations are done for the whole group (n = 130) between the creatinine clearance, the DTPA 99mTc clearance and the fixation rate of the DMSA 99mTc . The correlations obtained are:--Clcr Versus Cldtpa = 0,91.--Clcr Versus % Dmsa = 0,90. - Cldtpa Versus % Dmsa = 0,93. and indicate the two isotopic tests performed give similar quantitative results than creatinine clearance. Camera and computer allow to measure the separate renal function one by one, the two isotopic test giving similar values for each kidney. The results of these studies give a good concordance with the observed diseases, except for partial renal artery stenosis. The pyelic retention of DMSA 99mTc product, in condition of ureteral compression, gives a potential overestimation of this test and is a matter to debate. The extreme simplicity and facility of DMSA 99mTc procedures make this investigation accessible to any patient and give excellent morphological and functional tests. DTPA 99mTc clearances--global and separate kidney--give a more sensitive approach than DMSA 99mTc does because vascular captation , elimination rates could be focused. DTPA 99mTc procedure is to be used in patients with transplanted kidney, silent IVP kidney, contrast media contraindication or for exploring glomerular clearance without urine collection.

Adolescent↗
PubMedDate not supplied

Renal scintigraphy in insulin-dependent diabetes mellitus: early glomerular and urologic dysfunction.

Glomerular filtration rate (GFR) and renal plasma flow (RPF) were measured by intravenous injection of 99mTc-diethylenetriaminepentaacetic acid (DTPA) and 131I-Hippuran in 115 insulin-dependent diabetic patients with albumin excretion rates (AER) less than 200 micrograms/min, and in 45 normal subjects. Separate kidney function and urinary elimination were estimated by renography. GFR was increased in the diabetic patients (152 +/- 24 ml/min/1.73 m2 vs. 128 +/- 15) and correlated significantly with RPF (r = 0.5; p less than 10(-9)). No relationship was found between GFR and the duration of diabetes, blood glucose, HbA1c, or AER. Fifty patients were hyperfiltering with RPF and filtration fraction higher than those in the normofiltering group. Slow intrarenal or pyeloureteral elimination, either unilateral or bilateral, was observed in 3 controls and 60 diabetic subjects (24 hyperfiltering; 36 normofiltering) and did not disappear with the patient in the standing position. In these 60 patients, mean age, duration of diabetes, blood glucose, HbA1c, 24 h albumin excretion rate, and frequency of peripheral or autonomic neuropathy did not differ from patients with normal scintigraphy; GFR was lower in the group with slow elimination, but not significantly so. 99mTc-DTPA renal uptake was symmetric in all the controls; asymmetric renal uptake with asymmetric GFR was observed in 13 patients (7 hyperfiltering; 6 normofiltering) and often associated with slower elimination. No evidence for renal stenotic atheroma or parenchymatous disease was found on the angiopyeloureterography. The results suggest that incipient uropathy is a very common phenomenon that occurs irrespective of glomerular dysfunction.

Diabetes Mellitus, Type 1↗