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F Jamar

Publications and source records attributed to F Jamar.

At least 19 recordsLinked to original sources
PubMed2004

Calculation of the renal perfusion and glomerular filtration rate from the renal impulse response obtained with MRI.

The aim of this study was to assess the importance of deconvolution for the calculation of renal perfusion and glomerular filtration rate (GFR) on the basis of concentration-time curves as measured with perfusion MRI. Six rabbits were scanned dynamically after injection of a gadolinium chelate. Concentration-time curves were generated by manually drawing regions of interest in the aorta and the renal cortex. To remove the dependency on the arterial input function, a regularized structured total least-squares deconvolution algorithm was used to calculate the renal impulse response. This curve was fitted by the sum of two gamma variate functions, corresponding to the passage of the contrast agent in the glomeruli and the proximal convoluted tubules. Tracer kinetics models were applied to these two functions to obtain the renal perfusion and GFR. For comparison, these two parameters were also calculated on the basis of the renal concentration-time curve before deconvolution. The renal perfusion values correlated well (r = 0.9, P = 0.014) with the values calculated by a validated upslope method. The GFR values correlated well (r = 0.9, P = 0.014) with the values obtained from the clearance of (51)Cr-EDTA. A comparison of the values obtained with and without deconvolution demonstrated the necessity of deconvolution.

Algorithms↗
PubMed2004

Parapharyngeal metastases from thyroid cancer.

AIM: To emphasise the pattern of lymphatic dissemination in the parapharyngeal space from thyroid cancer. PATIENTS AND METHOD: Among 696 patients treated for thyroid cancer between 1986 and 2001, parapharyngeal metastasis was diagnosed in three patients, previously treated for papillary thyroid carcinoma. RESULTS: All three patients have been treated by surgical resection through lateral cervical approach. Two of them were controlled regionally whereas the remaining one had a submucosal pharyngeal metastasis locally resected 27 months after parapharyngeal resection. CONCLUSIONS: Parapharyngeal metastasis is rare, but should be a recognized pattern of lymphatic dissemination from thyroid carcinoma to avoid unnecessary radioiodine and because surgical resection is efficacious with acceptable morbidity.

Carcinoma, Papillary↗
PubMed2003

[Pharyngoesophagolaryngeal metastases of medullary thyroid carcinoma. A case report].

We report the case of a patient with medullary thyroid carcinoma (MTC) who presented multiple pharyngoesophagolaryngeal metastases detected by flexible laryngoscopy. Pathology confirmed the diagnosis after resection with CO2 laser under direct laryngoscopy. Because of worsening dyspnea, complete circular pharyngolaryngectomy was performed with reconstruction of the pharyngeal region with a major pectoralis musculocutaneous flap. The postoperative period was satisfactory. At 17 months, calcitonin level was elevated; subcutaneous cervical metastases of the MTC developed and were resected. At 27 months, oral nutrition and phonation remained satisfactory. We discuss the diagnostic and therapeutic strategies used for this very unusual form of locoregional spread of medullary carcinoma of the thyroid gland.

Biomarkers, Tumor↗
PubMed2002

Scintigraphy using a technetium 99m-labelled anti-E-selectin Fab fragment in rheumatoid arthritis.

OBJECTIVE: We previously described a novel radiolabelled monoclonal antibody (1.2B6), which reacts with porcine E-selectin, for targeting activated endothelium as a means of imaging inflammatory disorders, and presented initial clinical work based on (111)In-labelled antibody. The aim of the present study was to evaluate a Fab fragment of 1.2B6 labelled with (99m)Tc in patients with rheumatoid arthritis (RA) by comparison with (i) (111)In-labelled 1.2B6 F(ab')(2) and (ii) conventional bone scanning. METHODS: (99m)Tc-1.2B6-Fab ( approximately 440 MBq) and (111)In-1.2B6-F(ab')(2) ( approximately 27 MBq) were compared in 10 patients using a double-isotope protocol. Images were obtained 4 and 20-24 h after injection. Two normal volunteers were also imaged. In a separate group of 16 patients, (99m)Tc-1.2B6-Fab and (99m)Tc-oxidronate ((99m)Tc-HDP) ( approximately 740 MBq) were compared on the basis of visual and semi-quantitative analysis of joint uptake (joint/soft tissue ratios) 4 h after injection. The respective biodistributions and blood clearances of the two 1.2B6 fragments were also compared. RESULTS: Image contrast was slightly better with (99m)Tc-Fab at 4 h but equal for the two tracers at 24 h. Diagnostic accuracy, taking joint tenderness or swelling as the clinical endpoint, was 76% for both fragments at 24 h. Plasma clearance of (99m)Tc-Fab was faster than that of (111)In-F(ab')(2) (t(1/2) 142 vs 421 min; P<0.0001). (99m)Tc-Fab appeared somewhat unstable in vivo, as shown by activity in the thyroid gland and bowel. The diagnostic accuracy of (99m)Tc-Fab was 88%, higher than that of (99m)Tc-HDP (57%) as a result of the low specificity of the latter in RA. Receiver operating characteristic (ROC) curve analysis using joint/soft tissue ratios as a variable cut-off showed that (99m)Tc-Fab discriminates better than (99m)Tc-HDP between actively inflamed and silent joints (Z=4.72; P<0.0001). No uptake of (99m)Tc-Fab was observed by inactive or normal joints, whereas (99m)Tc-HDP was taken up by all joints to a variable degree, making the decision as to whether a particular joint is actively involved or chronically damaged very difficult. CONCLUSION: (99m)Tc-anti-E-selectin-Fab scintigraphy can be used successfully to image synovitis with better specificity than (99m)Tc-HDP bone scanning. The advantages over (111)In-1.2B6-F(ab')(2) are easier availability of the radionuclide, improved physical properties and optimal imaging 4 h after injection.

Adult↗
PubMed2001

Video-assisted neck exploration for primary and secondary hyperparathyroidism: initial experience.

BACKGROUND: Minimally invasive surgery (MIS) for primary hyperparathyroidism includes unilateral neck exploration, access via a totally endoscopic approach, and access via a video-assisted procedure. We report herein our initial experience with the video-assisted neck exploration procedure for primary (PHPT) and secondary hyperparathyroidism (SHPT). METHODS: Between June 1999 and May 2000, 35 patients were selected for PHPT (n = 25) and SHPT (n = 10). In all cases, video-assisted neck exploration was performed under general anesthesia, leading to selective adenoma removal in PHPT or subtotal parathyroid resection in SHPT. Patient selection was based on the preoperative localization studies (ultrasonography and sestamibi scintigraphy). RESULTS: Five of the 25 patients operated on for PHPT (20%) and three of the 10 patients who underwent surgery for SHPT (30 %) were converted to a conventional surgical technique. The mean operative times in PHPT and SHPT were 48.9 +/- 18.7 min and 136.8 +/- 18.7 min, respectively. The recurrent laryngeal nerve was identified in 45% of the patients. The median size and weight of the resected parathyroid glands were 1.8 cm (range, 0.9-2.5) and 1 g (range, 0.5-7), respectively. The length of skin incision was 24 +/- 1.2 mm. All but one patient are currently cured, with a median follow-up of 6 months (range, 2-13). Postoperative complications included hematoma and transient hoarseness in one patient each (2.85%). The median pain intensity, based on the visual analogue scale (VAS) method, as measured at postoperative day 1 was 0.5 (range, 0-3.6). In the PHPT group, the postoperative hospital stay was

Adult↗
PubMed2001

Tc-99m HDP bone scan showing bone changes in a case of tuberous sclerosis or Bourneville's disease.

Whole-body Tc-99m HDP scintigraphy was performed in a 25-year-old woman with known tuberous sclerosis. The scintigraphic pattern showed multiple foci of abnormal activity over the hands, phalanges, feet, tibias, fibulas, ulnas, and radii, where radiographs showed periosteal apposition, irregular cortical thickening, and cystlike lesions on the phalanges. The spine, pelvis, and ribs showed heterogeneous tracer uptake where radiographs showed patchy areas of increased bone density. This radiographic pattern is characteristic of osseous tuberous sclerosis. Although previous reports suggested the opposite conclusion, this observation indicates that an abnormal result of bone scintiscan can be observed in osseous tuberous sclerosis.

Adult↗
PubMed2000

Effects on human and nonhuman primate immune response of a new rat anti-CD2 monoclonal antibody.

BACKGROUND: Nonhuman primate models are highly clinically relevant in transplantation. The development of immunosuppressive tools or a tolerogenic regimen for primate models therefore represents an important goal of transplantation immunological research. Hence, we have developed a rat monoclonal antibody (mAb) that recognizes the CD2 molecule (LO-CD2b) on both human and nonhuman primate cells. METHODS: The LO-CD2b mAb has been characterized by flow cytometry, E-rosetting inhibition, and Western blotting. In vitro inhibition of immune responses by LO-CD2b was assessed after both mitogenic and allogeneic stimulation in mixed lymphocyte reactions (MLR). Several LO-CD2b dose and time responses were tested. In vivo, peripheral and lymph node T-cell depletion was examined both by flow cytometry and immunohistology in 10 baboons that received intravenous injection of LO-CD2b at different doses and time courses. Xenosensitization (anti-rat) was assessed by ELISA. Renal allograft survival was followed in two baboons treated with iterative LO-CD2b injections. RESULTS: In vitro, LO-CD2b binds a lymphocyte antigenic determinant of 52 kDa that is recognized by other well-characterized anti-CD2 mAbs (T11, Leu5b). LO-CD2b recognized natural killer CD2+ cells. Administration of 200 ng/ml LO-CD2b almost completely inhibited human and baboon mitogenic stimulation. Allogeneic baboon and human MLR were completely inhibited by the addition of LO-CD2b (at 312 ng/ml) on the day of the initiation of culture; when added after 1 or 2 days, LO-CD2b still provided a significant MLR inhibition (>50%). Incubation of LO-CD2b with baboon peripheral blood mononuclear cells produced very low cytokine levels (interferon-y, tumor necrosis factor-alpha, interleukin 2). In secondary MLR, baboon peripheral blood mononuclear cells previously incubated with LO-CD2b were unable to respond to a second allogeneic stimulation but were able to react to mitogens. In vivo, within the first hour after LO-CD2b injection (at 0.15, 0.5, and 2 mg/kg), an 85-90% peripheral depletion of CD2+ cells was observed. A partial T-cell depletion in inguinal lymph nodes was seen after 1 week. The mechanism of peripheral T-cell depletion could have been antibody-dependent cell cytotoxicity or opsonization but was complement independent. Iterative LO-CD2b injections (12 days at 0.35 mg/kg) slightly prolonged the renal allograft survival in two baboons. CONCLUSION: LO-CD2b is a nonactivating rat anti-CD2 mAb able to strongly inhibit both mitogenic and allogeneic responses in human and nonhuman primates. In vivo, LO-CD2b provides a rapid peripheral T-cell depletion, which is reversible within days after the cessation of injections. This rat mAb represents a very important tool for in vivo experimental investigation in nonhuman primates because it similarly reacts against human T cells in vitro.

Animals↗
PubMed2000

The role of radioactive somatostatin and its analogues in the control of tumor growth.

Peptide receptor scintigraphy with the radioactive somatostatin analogue [111In-DTPA-D-Phe1]octreotide is a sensitive and specific technique to show in vivo the presence and abundance of somatostatin receptors on various tumors. With this technique primary tumors and metastases of neuroendocrine cancers as well as of many other cancer types can be localized. This technique is currently used to assess the possibility of peptide receptor radionuclide therapy with repeated administration of high doses of [111In-DTPA-D-Phe1]octreotide. 111In emits Auger and conversion electrons, having a tissue penetration of 0.02-10 microns and 200-500 microns, respectively. Thirty end-stage patients with mostly neuroendocrine progressing tumors were treated with [111In-DTPA-D-Phe1]octreotide, up to a maximal cumulative patient dose of about 74 GBq, in a phase-I trial. There were no major clinical side effects after up to 2 years of treatment, except that in a few patients a transient decline in platelet counts and lymphocyte subsets occurred. Promising beneficial effects on clinical symptoms, hormone production, and tumor proliferation were found. Of the 21 patients who received a cumulative dose of more than 20 GBq, eight showed stabilization of disease and six others a reduction in tumor size. There is a tendency towards better results in patients whose tumors have a higher accumulation of the radioligand. Peptide receptor radionuclide therapy is also feasible with 111In as the radionuclide. Theoretically, depending on the homogeneity of distribution of tumor cells expressing peptide receptors and the size of the tumor, beta-emitting radionuclides, e.g., 90Y, labeled to DOTA-chelated peptides may be more effective than 111In for peptide receptor radionuclide therapy. The first peptide receptor radionuclide therapy trials with [90Y-DOTA-Tyr3]octreotide started recently.

Cell Division↗
PubMed2000

Orbital metastasis as primary manifestation of thyroid carcinoma.

A 59-year-old woman with unknown primary tumor developed progressive painless left upper eyelid swelling and exophthalmos. Computed tomography (CT) showed a well-circumscribed left orbital mass producing bone lysis. Immunohistologic staining of the incisional biopsy specimen was positive for thyroglobulin, suggesting an orbital metastasis from thyroid carcinoma. At this time, thyroglobulin was high (1400 ng/dL). Total thyroidectomy with lymph node dissection disclosed a follicular carcinoma with microscopic foci of papillary variant follicular carcinoma. Two months after radioiodine treatment, the CT showed a regression of the orbital tumor mass with concomitant decrease in thyroglobulin (428 ng/dL). Although orbital metastases of thyroid carcinoma are uncommon, thyroid carcinoma has to be considered as a potential primary tumor in a patient with an orbital metastasis.

Carcinoma, Papillary, Follicular↗
PubMed2000

OctreoTher: ongoing early clinical development of a somatostatin-receptor-targeted radionuclide antineoplastic therapy.

OctreoTher ((90)Y-DOTA-D-Phe(1)-Tyr(3)-octreotide, a.k.a. (90)Y-SMT 487) consists of a somatostatin peptide analogue (Tyr(3)-octreotide), coupled with a complexing moiety (DOTA), and labeled with a tightly bound beta-emitter (yttrium-90). By targeting somatostatin receptor-positive tumors (as imaged by OctreaScan it may deliver a tumoricidal dose of radiation. Phase I clinical trials, conducted in patients with neuroendocrine tumors, established the safety and tolerability of the dose selected for further study and demonstrated the capacity of OctreoTher to deliver radiation doses to tumors that resulted in significant neuroendocrine tumor shrinkage. Novartis-sponsored phase II studies will soon begin to test the efficacy of OctreoTher in breast and small cell lung cancer. A fixed-dose regimen of 120 mCi/cycle x 3 cycles administered with concomitant amino acid infusion has been chosen for the study. Phase I data and published literature support that this fixed dose regimen will be safely tolerated.

Animals↗
PubMed2000

A survey of guidelines in 27 EANM associated societies by the EANM Task Group on Quality Assurance and Standardisation. European Association of Nuclear Medicine.

The main aim of the EANM Task Group on Quality Assurance and Standardisation is to develop harmonised clinical procedures that are accepted within Europe. In order to achieve an evidence-based analysis of guidelines in the 27 EANM member societies, a survey was conducted. A questionnaire in mid 1999 investigated three major questions: (1) current status of national guidelines in EANM member societies, (2) specification of the cover and level of these national guidelines, and (3) future desires for national, EANM and SNM guidelines. The complete response rate was 96% (26/27). Guidelines are required by 19 of 27 member societies and have been initiated by 16 member societies. Guidelines are provided by 13 member societies, generally in the national language. In ten societies, specialists other than nuclear medicine physicians, mostly physicists and radiopharmacists, take the lead on some guidelines. Moreover, in some national societies there is active collaboration with other medical societies when writing guidelines, particularly cardiology societies. Currently, only 18% of the necessary procedure guidelines are covered. Compared with a survey conducted in 1993 by the EANM Committee on Quality Assurance and Standardisation, slow progress has been made in this regard, but compared with a survey conducted by the same committee in 1996 in 23 EANM member societies, the number of member societies providing guidelines has approximately doubled. Moreover, 26 of 27 member societies share a commitment for future development of guidelines and 21 of 27 prefer EANM guidelines to national guidelines. The results of this questionnaire justify the need for close co-operation between EANM, EANM member societies, the EANM Task Group on "Quality Assurance and Standardisation" and the Guideline Committee of the SNM. The clinical priorities are considered to be cardiac, renal and brain procedures.

Data Collection↗
PubMed1999

The author replies

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Journal Article↗
PubMed1999

Expression of aquaporin-1 in a long-term peritoneal dialysis patient with impaired transcellular water transport.

Aquaporin-1 (AQP1) has been claimed to be the molecular counterpart of the transcellular pathway for free-water movement across the peritoneum during peritoneal dialysis. We report the case of a 67-year-old man, on peritoneal dialysis for 11 years, in whom ultrafiltration failure due to an abolition of the transcellular water transfer (documented by a loss of sodium sieving) was associated with an apparently normal expression of AQP1. We suggest that an alteration of AQP1 structure, rather than of its expression, accounts for this observation.

Aged↗
PubMed1999

Radiolabelled somatostatin analogue(s) for peptide receptor scintigraphy and radionuclide therapy.

BACKGROUND: Peptide receptor scintigraphy with the radioactive somatostatin analogue, [111In-DTPA0]octreotide, is a sensitive and specific technique to show in vivo the presence and abundance of somatostatin receptors on various tumours. AIM: With this technique primary tumours and metastases of neuroendocrine cancers as well as of many other cancer-types can be localised. This technique is currently used to assess the possibility of peptide receptor radionuclide therapy (PRRT) with repeated administrations of high doses of [111In-DTPA0)octreotide. 111In emits Auger and conversion electrons having a tissue penetration of 0.02-10 microns and 200 to 500 microns, respectively. PATIENTS AND METHODS: Thirty end-stage patients with mostly neuroendocrine progressing tumours were treated with [111In-DTPA0]octreotide, up to a maximal cumulative patient dose of about 74 GBq, in a phase I trial. RESULTS: There were no major clinical side effects after up to two years treatment, except that in a few patients a transient decline in platelets counts and lymphocyte subsets occurred. Promising beneficial effects on clinical symptoms, hormone production and tumour proliferation were found. Of the 21 patients who received a cumulative dose of more than 20 GBq, eight patients showed stabilisation of disease and six other patients a reduction in size of tumours. There is a tendency towards better results in patients whose tumours have a higher accumulation of the radioligand. CONCLUSIONS: PRRT is feasible, also with 111In as radionuclide. Depending on the homogeneity of distribution of tumour cells expressing peptide receptors and the size of the tumour, beta-emitting radionuclides, e.g., 90Y, labelled to DOTA-chelated peptides, are also attractive candidates for PRRT. The first PRRT trials with [90Y-DOTA0,Tyr3]octreotide started recently.

Animals↗