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J F Chatal

Publications and source records attributed to J F Chatal.

143 records · Page 8Linked to original sources
PubMed1976

[Adrenal scintigraphy using 131 I-19-iodocholesterol. Value in the exploration of Cushing's syndrome].

On the basis of 7 cases representing the essential types of aetiology of Cushing's syndrome, it is possible to define the value, limitations and role of adrenal scintigraphy using 131I-19-iodocholesterol in the diagnostic investigation of hypercortisolism. The essential value of the investigation is morphological rather than functional drome. Thus adrenal scintigraphy has the same role in diagnostic investigation as various radiological procedures such as pneumoperitoneum and angiography. The latter, however, are technically difficult and fraught with risk, in contrast to the isotopic examination. The principle limitations of the method are not dosimetric but lie in the relative difficulty of interpretation of the documents obtained.

Adrenal Gland Neoplasms↗
PubMed1975

[Diagnostic value of ytterbium 169 citrate in cancerology].

Several radio-nuclides are used in Cancerology for their tumoral tropism and, in fact, 67 gallium citrate and 57Co bleomycin almost exclusively. But, these nuclides have some disadvantages, such as we tried to evaluate the interest to 169 ytterbium citrate; this radiolanthanide has already been studied in animals for its affinity for tumoral and normal tissues by HISADA and al. [5]. Our preliminary study has been made on 44 patients bearing different neoplastic diseases. In 8 cases, we have measured the percent radioactivity excreted by urines and stools in 5 days following injection. Scintigraphy of most of the patients has been made at 48 hours, but for several cases of non malignant or malignant pulmonary diseases, a cinetic study allowed us to follow the evolution of the intensity the pathological fixation. The results show: -- a weak urinary and fecal excretion; -- a good scintigraphic contrast from 48 hours; -- an important radioactive fixation in bone metastasis of various origins, in primary and secondary brain and liver tumors; -- an important radioactive fixation in lung cancers and inflammatory diseases however our preliminary cinetic study seems to be a good mean of differential diagnosis. At the cost of a non negligeable irradiation dose of bone, the tumoral fixation can be considered as good and the cinetic studies we intend to develop will perhaps improve the specificity of the diagnosis.

Bone Neoplasms↗
PubMedDate not supplied

Site-specific conjugation of chain-terminal chelating polymers to Fab' fragments of anti-CEA mAb: effect of linkage type and polymer size on conjugate biodistribution in nude mice bearing human colorectal carcinoma.

Polylysine-based chelating polymers were used for site-specific modification of anti-CEA mAb Fab' fragments via their SH group distal to the antigen-binding site of the antibody molecule. Conjugation was performed using chain-terminal (pyridyldithio)propionate or 4-(p-maleimidophenyl)butyrate moieties to form reducible (S-S) or stable (S-C) bonds between a polymer and Fab' molecule, respectively. One S-S conjugate (S-S9) and two different S-C conjugates (S-C3 and S-C9) were prepared using 3- and 9-kDa molecular weight polymers. No significant loss of immunoreactivity was observed in solid-phase immunoassay, 90-95% of 111In-labeled conjugates being bound to CEA-coated Sepharose beads. After labeling with 111In, the conjugates had a specific radioactivity of 90-120 microCi/micrograms. Injected in nude mice bearing LS 174T carcinoma, the conjugates produced different biodistribution patterns. S-S9 was practically unable to accumulate in tumor and produced very rapid blood clearance of radioactivity and high uptake of radioactivity in liver, spleen, and especially kidneys (225% ID/g 24 h postinjection). S-C3 and S-C9 produced practically the same blood clearances (much slower than that of S-S9) and significant tumor uptake (9-10% ID/g at 24 h). S-C3 gave significantly lower radioactivity in spleen, skin, and bones, and cleared more rapidly from liver and kidneys. Renal uptake for S-C3 and S-C9 was rather high (45% ID/g at 24 h), but much lower than for S-S9.

Adenocarcinoma↗
PubMedDate not supplied

Synthesis of new bivalent peptides for applications in the Affinity Enhancement System.

The feasibility of two-step radioimmunotherapy (RIT) of cancer by the Affinity Enhancement System (AES) has been demonstrated in experimental and clinical studies. This technique, associating a bispecific antibody and a bivalent peptide radiolabeled with iodine-131, has been developed to reduce toxicity and to improve therapeutic efficacy compared to one-step targeting methods. The use of AES with different beta-emitters such as rhenium-188, samarium-153, or lutetium-177 or alpha-emitters such as actinium-225 or bismuth-213 is now considered. Thus three new peptides, designed to allow for the coupling of a variety of bifunctional chelating agents BCA, were synthesized by associating two glycyl-succinyl-histamine (GSH) arms, which are recognized by the 679 monoclonal antibody (mAb-679), with different binding agents, such as p-nitrophenylalanine or N,N-bis(carboxymethyl)-4-N'-(9-fluorenylmethyloxycarbonyl)aminobenzylamine. Immunoreactivity and serum stability evaluation were performed for each synthesized peptide. One of the three peptides (LM218) proved to be more stable than the others, and three different BCAs were coupled to LM218 (CITC-DTPA, CITC-TTHA, and CITC-CHXA''DTPA). One of these products, LM218-BzTTHA was radiolabeled with indium-111 without loss of immunoreactivity toward the mAb-679. These new peptides will allow pretargeted RIT with a large variety of radionuclides, to adapt the choice of the radionuclide (LET, half-life, penetrating emission) to the nature and size of targeted tumors.

Animals↗
PubMedDate not supplied

Lymphoscintigraphy in the sentinel lymph node technique for breast tumor: value of early and late images for the learning curve.

As the performance of early (H+1 to H+4) and late (D1) lymphoscintigraphic images raises organizational problems in outpatient surgery for breast cancer, only early images are generally obtained. The present study evaluated whether two series of images are better than one and defined the advantages of both methodologies. One hundred and eighteen patients with infiltrating breast carcinoma (T(0), T(1) and T(2)) were included in the study: 87 in group A (early and late images) and 31 in group B (only early images). All patients received two peritumoral injections of (99m)Tc-sulfur colloid, 15-18 MBq (group A) and <15 MBq (group B). During the operation, the patent blue bye technique was associated with radioactivity detection. The two groups were comparable for histological type and tumor size and localization. Successful localization of sentinel nodes on early lymphoscintigraphic images was significantly greater for group B. The identification of a sentinel node focus on early lymphoscintigraphy increased by 10% during the study. Sentinel node detection by the isotopic method alone, or the two methods combined, was comparable for both groups. In radioactivity detection, the count rate for sentinel nodes versus background (contralateral breast) was similar for the two groups. During the learning phase, two series of images gave a definite advantage. Subsequently, lymphoscintigraphy performed at +2 h was sufficient (the results for the two groups became indistinguishable).

Adult↗
PubMedDate not supplied

The joint Task Group on clinical utility of labelled antibodies of the Society of Nuclear Medicine Europa (SNME) and the European Nuclear Medicine Society (ENMS).

In September 1985 a task group on the clinical utility of labelled antibodies was founded by the Society of Nuclear Medicine - Europe. This document was elaborated to report the aims and the programs of the group. In September 1986 the European Nuclear Medicine Society decided to participate in this initiative and a joint task group was created. INITIAL DOCUMENT: A. The aims to the Task Group are to monitor, co-ordinate and promote research and clinical application of techniques using radiolabelled antibodies in nuclear medicine. A.1. The Group should develop into a major point of reference, giving scientific and technical support to each member of the Society involved in this field. B. To pursue these purposes it will be necessary to develop the following: B.1. Criteria to evaluate the suitability of antigen-antibody systems for tumour detection and/or therapy. B.2. Criteria for quality control of radioimmunoreagents. B.3. Criteria for the prevention of adverse reactions or damage due to the reagent. B.4. Selection of suitable dosimetric methods for diagnostic or therapeutic applications. B.5. Elaboration of protocols for clinical experiments, including appropriate techniques to be applied in single cases. B.6. Organization of cooperative studies. C. The Task Group should promote: C.1. Informal meetings between the members of the Group. C.2. Workshops open to the members of the Society and other researchers. C.3. Publication of reports in appropriate journals.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Deep hypotension induced by sodium nitroprusside in neurosurgery. II.--Cerebral hemodynamic effects and metabolic rate of oxygen (author's transl)].

The cerebral hemodynamic effects of sodium nitroprusside (S. N.) have been the object of animal studies mainly. During the only human study performed, the drop in mean arterial pressure (MAP) is limited to 67 mm Hg. The study of the evolution of cerebral blood flow (CBF) in cases of more severe hypotension (MAP less than 45 mm Hg) seems of some interest. The study was composed of the measurement of the CBF using Xenon 133 and the calculation of cerebral vascular resistances (CVR) as well as cerebral metabolic rate of oxygen (CMRO2). Eleven patients with an average age of 37 years underwent surgery for cerebral aneurism 10 to 15 days after the inaugural hemorrhagic accident, under narconeuroleptanalgesia and stable ventilatory conditions. They are divided into 2 groups: Group I, 9 patients with normal levels of consciousness; Group II, 2 patients either agitated or obnubilated. The study is composed of 3 successive measures: (1) (T0) during stable anesthesia just prior to hypotension; (2) (T1) after 5 minutes of hypotension (MAP = 40 +/- 7 MM Hg); (3) (T2) 20 minutes after having stopped S. N. infusion. For the 9 patients in Group I, CBF remains unchanged at T1, the CVR decreases (p less than 0.001) and CMRO2 decreases (p less than 0.05). At T2 all of these parameters return to T0 values. The postoperative clinical evolution is favorable and uncomplicated. For the 2 patients in Group II the CBF, initially higher, falls from 20 to 30 p. cent at T1 with a drastic reduction in CMRO2. Despite the improvement of these parameters at T2, a prolonged postoperative coma is observed. This study suggests that CBF and CMRO2 are important parameters to monitor during controlled severe hypotension. Decrease in MAP must be less than 50 p. cent of control value and time-limited.

Acid-Base Equilibrium↗
PubMedDate not supplied

[Ultrasonography and radiocholesterol scintigraphy in the topographic diagnosis of a pheochromocytoma (author's transl)].

Topographic diagnosis of adrenal pheochromocytoma were determined by ultrasonography in all 6 cases studied and by radiocholesterol scintigraphy in 6 out of 7 cases studied. It would appear that ultrasonography is preferable in the localization of an abdominal pheochromocytoma, whether adrenal or extra-adrenal. Intravenous urography along with rapid sequence nephrotomography and radiocholesterol scintigraphy, play a complementary role in confirming the topographic diagnosis. In case these methods prove unsuccessful or provide conflicting results, it is then possible to consider computed tomography, angiography and caval catheterization.

Adrenal Gland Neoplasms↗
PubMedDate not supplied

[Diagnostic value of thermography and Tc 99m bleomycin scintigraphy for nodules of the thyroid (author's transl)].

The combined interest of thermography and 99mTc Bleomycin scintigraphy in the differential diagnosis of a cold thyroid nodule was evaluated in 86 patients. In all cases a histological examination was performed. Of the 30 malignant nodules (clinically suspect and solitary nodules) 21 (70%) showed concentrations of 99mTc Bleomycin while only 7 of the 12 solitary malignant nodules did so. Among the 54 benign nodules the false positive rate was 54%. Thermography was positive in 26 (87%) of the 30 malignant nodules and in only 8 (67%) of the 12 solitary malignant nodules. For the 54 benign nodules the false positive rate was 72%. The combined results of the study do not provide any improvement in diagnostic accuracy. Thus it can be said that applications of 99mTc Bleomycin and thermography in the diagnosis of solitary hypofixiant nodules are of limited value.

Bleomycin↗
PubMedDate not supplied

Feasibility of radioimmunoguided surgery of colorectal carcinoma using indium 111 CEA specific antibody and simulation with a phantom using 2 steps targetting with bispecific antibody.

The study was undertaken to define the potential use of radiolabelled (Indium 111 or Technetium 99 m) carcinoembryonic antigen specific antibody (CEA f(ab')2) for the radioimmunodetection of colorectal cancer using an intraoperative hand-held gamma probe. A clinical study performed with ten patients showed that tumor with good uptake of CEA specific antibody could be detected with sufficient contrast only in two patients. Results of a biodistribution study performed with tumor fragment and normal tissue countings in a gamma counter showed high tumor uptake in five patients. There was no correlation between tumor uptake and the count rates measured intraoperatively. To increase the signal/background of the gamma probe, a simulation study with a peritoneal cavity phantom was performed. We determined the efficiency of a two steps targetting method compared to the direct method. We simulated different tumor sizes with plexiglas balls (0.5, 1, 2, 5 ml) and tested two scintillators (NaI, BgO). Experiments were performed with 111 In and 99 m Tc. The two steps targetting method was better than direct method. The results of simulation with direct method radiolabelled with 111 in confirmed our clinical study: no efficiency of a gamma probe for the surgeon to detect a tumor. However the two steps targetting method (indirect labelling method) was very encouraging to detect tumors (size 1 and 2 ml) and definitively convincing with 99 m Tc.

Antibody Specificity↗