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J Martin-Comin

Publications and source records attributed to J Martin-Comin.

At least 19 recordsLinked to original sources
PubMed1997

Radiopharmaceuticals for the study of inflammatory processes: a review.

Recent advances in our understanding of the pathophysiology of inflammatory processes at the molecular level, combined with progress in radiopharmaceutical sciences, has boosted the development of nuclear medicine techniques for the diagnosis of infection/inflammation. The use of radiolabelled white blood cells has been studied and evaluated in several pathologies and is still the reference method. Several alternative approaches, however, have been developed that may, in the future, improve the specificity and the ease of use of the technique. For the first time, a radiopharmaceutical that may distinguish between sterile and septic inflammation, 99Tcm-Infecton, has been developed. Also, monoclonal antibody fragments, cytokines and a variety of new synthetic peptides that bind specifically to granulocytes have been prepared. Particularly promising appears to be the detection of the expression of adhesion molecules by activated endothelium as a first-line technique for the detection of inflammatory foci. For the diagnosis of autoimmunity and chronic inflammatory processes, important progress has also been made. Autoimmunity can now be studied by in vivo detection of tissue-infiltrating activated lymphocytes by radiolabelled interleukin-2. A radiopharmaceutical for the diagnosis of monocyte infiltration, J001X, is also available, and the commercially available Octreoscan holds promise in autoimmune and chronic inflammatory diseases. The efforts of the scientific community have given us new perspectives in diagnostic nuclear medicine: easier techniques that promise better sensitivity and specificity are now also being tested for the study of new disease conditions. The results of the clinical trials now in progress will determine the future of this challenging and fascinating field and the role of nuclear medicine in the management of patients with infection/inflammation.

Antibodies, Monoclonal↗
PubMed1997

MAG3 renogram deconvolution in kidney transplantation: utility of the measurement of initial tracer uptake.

UNLABELLED: The study of renal retention function by deconvolution analysis of renographic curves is useful to calculate quantitative parameters in renal studies. The aim of the work is to evaluate the usefulness of 99mTc-MAG3 renogram deconvolution in renal function monitoring of kidney graft recipients. METHODS: Forty-three kidney grafts and 112 renograms were studied: 41 were diagnosed as functioning graft, 35 as acute tubular necrosis, 24 as acute rejection, 8 as obstruction and 4 as cyclosporin toxicity. The parameters calculated were mean transit time (MTT), time at 20% of renal retention function (T20) and initial uptake (IU). RESULTS: MTT and T20 were significantly longer in obstructives than in functioning grafts (p < 0.001). Initial uptake was significantly lower in acute tubular necrosis (ATN) and acute rejection (p < 0.001) and in obstructives (p < 0.05) than in functioning grafts. The joint evaluation of MTT and IU allowed to diagnose cases with graft function severely impaired. CONCLUSION: Initial uptake is useful in evaluating post-transplantation complications and in combination with MTT and T20 reflects renal dysfunction severity.

Adult↗
PubMed1996

Simultaneous administration of 99Tcm-HMPAO-labelled autologous leukocytes and 111In-labelled non-specific polyclonal human immunoglobulin G in bone and joint infections.

The aim of this study was to investigate the ability of 111In-labelled human polyclonal immunoglobulin G (111In-IgG) to localize bone and joint infections compared with 99Tcm-HMAPO-labelled leukocytes (99Tcm-WBC). Thirty-four patients routinely referred for investigation of bone and joint infections were studied. In all patients, a bone scan using 99Tcm-MDP was initially obtained. Subsequently, 99Tcm-WBC and 111In-IgG were simultaneously injected and images obtained at 30 min, 4 h and 24 h post-injection. Diagnostic accuracy was established by bacteriology of specimens obtained by needle aspiration and/or surgery, other imaging methods and clinical follow-up. The images were read by three experienced observers blinded to any other information; the clinical suspicion of infection and the diagnosis were established when two observers agreed. Infection was confirmed in 11 patients. The 99Tcm-WBC scans gave 8 true-positive, 5 false-positive, 18 true-negative and 3 false-negative results. With 111In-IgG, the figures were 7, 6, 17 and 4, respectively. The sensitivity, specificity and accuracy were 72.7%, 78.2% and 76.4% respectively for the labelled leukocytes and 63.6%, 73.9% and 70.6% respectively for 111In-IgG. There was greater agreement between the observers with 99Tcm-WBC than 111In-IgG. In this study, 111In-IgG was less sensitive and less specific than 99Tcm-WBC scintigraphy for the diagnosis of chronic infections, but these differences were not significant. Both tracers appear to be useful in the diagnosis of bone and joint infections. However, our results were less reliable for the diagnosis of an infected prosthesis.

Adult↗
PubMed1995

Simultaneous administration of 111In-human immunoglobulin and 99mTc-HMPAO labelled leucocytes in inflammatory bowel disease.

Technetium-99m hexamethylpropylene amine oxime (HMPAO) labelled leucocytes and indium-111 polyclonal immunoglobulin (IgG) were simultaneously injected into a group of 27 patients routinely referred for the investigation of inflammatory bowel disease (IBD). Ten-minute anterior abdomen and tail on detector views were obtained at 30 min, 4 h and 24 h p.i. of both tracers. The diagnosis of IBD was obtained in all cases by endoscopy with biopsy and/or surgery. Images were blindly evaluated by two experienced observers who only knew of the clinical suspicion of IBD. IBD was confirmed in 20 patients (12 with Crohn's disease and eight with ulcerative colitis). Sensitivity, specificity and accuracy were 100%, 85% and 96% respectively for labelled leucocytes and 70%, 85% and 74% for IgG. Both IgG and leucocyte scans were normal in six out of seven patients in whom a diagnosis of IBD was excluded; the remaining patient, with ischaemic colitis, was falsely positive with both agents. As far as disease extension is concerned, the IgG study localized 27 diseased segments, whereas 49 were seen with the leucocyte study. Eighty-four segments were normal and 25 showed tracer uptake with both agents. Twenty-four were positive only with the leucocyte study and two were positive only with the IgG study. Agreement between the agents was 80.7%. These results confirm that 111In-human polyclonal scintigraphy is less sensitive than 99mTc-HMPAO scintigraphy both for the diagnosis of IBD and in the evaluation of disease extension. Nevertheless, if leucocyte labelling is not available, labelled IgG can be used only for diagnostic purposes.

Adolescent↗
PubMed1994

99Tcm-MAG3 renogram deconvolution in normal subjects and in normal functioning kidney grafts.

This study provides values of transit times obtained by 99Tcm- mercaptoacetyl triglycine (99Tcm-MAG3) renogram deconvolution for both normal subjects and kidney graft recipients. The analysis included 50 healthy kidney units from 25 volunteers and 28 normal functioning kidney grafts. The parameters calculated for the whole kidney (WK) and for the renal parenchyma (P) were: mean transit time (MTT) and times at 20% (T20) and 80% (T80) of renal retention function initial height. For healthy kidneys the WK MTT was 174 +/- 27 s and P MTT 148 +/- 22 s. The WK T20 values were 230 +/- 33 s and P T20 231 +/- 34 s. The WK T80 was 108 +/- 19 s and P T80 106 +/- 12 s. Whole kidney and parenchymal values of transit times for normal functioning kidney grafts do not present significant differences with respect to healthy kidneys.

Adolescent↗
PubMed1994

Evaluation of obstructed kidneys by discriminant analysis of 99mTc-MAG3 renograms.

This study sought to develop a method of improving the differential diagnostic between healthy and obstructed kidneys using only parameters derived from the 99mTc-MAG3 renogram. The analysis included data from 46 healthy and 36 obstructed kidney units. The parameters calculated were: mean transit time (MTT), time at 20% of the initial height of the renal retention function (T20) and time to peak of the renogram (TP). A discriminant analysis was carried out to obtain a discriminant function in order to differentiate between the two groups. The best results were obtained using the function: (2.5629 InT20) + (2.1280 In TP) -27.1224 which correctly classified 97.56% of the cases, giving a sensitivity of 94.44% and a specificity of 99.99%.

Adult↗
PubMed1991

Granulocyte-specific monoclonal antibody technetium-99m-BW 250/183 and indium-111 oxine-labelled leucocyte scintigraphy in inflammatory bowel disease.

Thirty-three patients suspected of suffering from inflammatory bowel disease were studied. Autologous leucocytes were labelled with indium 111 oxine and re-injected simultaneously with 0.3-0.5 mg of technetium 99m granulocyte-specific monoclonal antibody BW 250/183. Two scans were obtained, the early scan 3-4 h postinjection (p.i.) and the late scan 18-24 h p.i. Using the endoscopy study as standard, the diagnostic accuracy of both agents was determined. Sensitivity, specificity and accuracy of 111In scans was 88.8%, 100.0% and 93.7% at 4 h and 94.7%, 100.0% and 96.9% at 24 h, respectively. Concerning the results using antibodies, the values were 61.1%, 100.0% and 78.1% at 4 h and 78.9%, 92.8% and 84.8% at 24 h, respectively. Segmental analysis showed concordance in 89.3% and 93.3% of the cases at 4 and 24 h, respectively. Though less sensitive and less accurate than scanning employing indium 111 leucocytes, BW 250/183 granulocyte-specific scintigraphy can be used for inflammatory bowel disease diagnosis and localization.

Adult↗
PubMed1988

Calculation of portal contribution to hepatic blood flow with 99mTc-microcolloids. A noninvasive method to diagnose liver graft rejection.

The portal contribution (PC) to hepatic blood flow was calculated in 13 liver graft patients and 13 normal volunteers. The method is based on the quantification and normalization of the liver and spleen activity after the administration of 7 mCi (259 MBq) of 99mTc microcolloid. Forty examinations were performed in liver grafts and 13 in normal subjects. The PC was significantly higher in normal native liver (64.0 +/- 3.0%) than in functioning grafts (58.8 +/- 3.1%). In acutely rejecting patients, PC was significantly lower (52.4 +/- 2.0%) than in functioning grafts and similar to that observed in cholangitis (53.5 +/- 0.7%). The PC increases again once rejection has resolved (57.3 +/- 2.6%). During hepatitis post-transplant PC values (59.7 +/- 3.4%) were similar to those observed in functioning grafts. Overall, PC values over 55% are very unlikely to be due to rejection.

Adult↗
PubMed1986

111In-oxine-labelled autologous leucocytes in inflammatory bowel disease: new scintigraphic activity index.

The usefulness of scintigraphy with 111In-oxine-labelled autologous leucocytes was investigated in 27 patients with inflammatory bowel disease (IBD): 16 with ulcerative colitis and 11 with Crohn's disease. Scans were performed 2-4 h (early scan) and at 24 h (late scan) after leucocyte reinjection. No false-negative results occurred in the early scan; however, in the late scan, 2 patients with Crohn's disease had a normal scintigram. A new index of activity (Il) based on the number and relative activity of abnormal 111In-leucocyte zones was used for scan quantitation. All patients with clinically active IBD had Il greater than or equal to 2. The scintigraphic index showed a significant correlation with the Harvey clinical index, especially in patients with ulcerative colitis. Our results suggest that an early scan (2-4 h) provides useful information in cases of IBD, and that Il greater than or equal to 2 is indicative of the degree of disease activity in such patients.

Adolescent↗