Rapid quality control for testing the radiochemical purity of 99Tc(m)-tetrofosmin.

We describe a new thin-layer chromatography (TLC) method to evaluate the radiochemical purity of 99Tc(m)-tetrofosmin without the drawbacks of toxicity, solvent ratios and time requirement associated with the standard TLC method. The new method uses miniaturized instant TLC plates impregnated with silica gel (ITLCTM/SG, 2.5 x 10 cm) for the stationary phase and 2-butanone for the mobile phase. The standard TLC method was performed with ITLCTM/SG plates (5 x 20 cm) and dichloromethane/acetone (65:35, v/v). Thirty five preparations were analysed by both methods with a storage phosphor imaging system to determine the percentages of hydrolyzed-reduced 99Tc(m) compound (99Tc(m)O2), 99Tc(m)-tetrofosmin and free 99Tc(m)-pertechnetate (99Tc(m)O4(-)). Using the miniaturized TLC method, 99Tc(m)-tetrofosmin had a mean Rf value of 0.55 (standard deviation, 0.05), while 99Tc(m)O4(-) migrated with the solvent front (Rf=1) and 99Tc(m)O2 remained at the origin of the strips (Rf=0). No significant difference was found between miniaturized and standard TLC methods for the radiochemical purity of 99Tc(m)-tetrofosmin using the Wilcoxon matched-pair signed-rank test (P=0.82). Furthermore, the two methods showed a good correlation as measured by the Spearman rank coefficient (r=0.89) and were in perfect agreement, with a kappa index of +1, for a cut-point between positive and negative set at 90%. In conclusion, the results indicate that the miniaturized TLC method is effective for the routine evaluation of the radiochemical purity of 99Tc(m)-tetrofosmin, without some of the drawbacks of the standard method.

Prognostic impact of cathepsin D and c-erbB-2 oncoprotein in a subgroup of node-negative breast cancer patients with low histological grade tumors.

Some node-negative breast cancer patients, with initially good prognosis, relapse from their cancer and are poorly identified. In the present study, based on prospective data of 197 tumors, we measured cathepsin D (cath D, n=197), pS2 protein (n=125), c-erbB-2 oncoprotein (n=100) and epidermal growth factor receptor (EGF-R, n=99) to better define the risk of relapse of node-negative patients in comparison with that defined by the clinical and histological factors. The median follow-up in surviving patients was 75 months. Univariate analysis indicated that patients with histological grade III tumors (the Scarff, Bloom and Richardson classification) had a much poorer prognosis than those with histological grade I or II tumors (P=0.0027 for relapse-free survival and P=0.0156 for overall survival). When the population of node-negative patients was divided by tertiles, high cath D levels showed a significant association with an early relapse (P=0.0316). Using cut-off values, patients with high cath D (> or =25 pmol/mg protein) or c-erbB-2 oncoprotein (> or =4 Human Neu Unit/microg protein) levels, had a significant worse relapse-free survival (P=0.0147 and 0.0417, respectively). No prognostic information was supported by pS2 protein or EGF-R measurements. In multivariate analysis, histological grade, cath D and c-erbB-2 oncoprotein remained independent predictors of recurrence (P=0.005, 0.0361 and 0.0321, respectively). By combining low levels of cath D and c-erbB-2 oncoprotein in histological grade I or II tumors, we identified a subgroup of patients with a 100% relapse-free survival probability at 6 years of follow-up. Moreover, the subgroup of patients with histological grade I or II tumors and high values of both cath D and c-erbB-2 oncoprotein showed a prognosis as poor as the subgroup defined by histological grade III alone, respectively 66% and 70% relapse-free survival at 6 years of follow-up. In conclusion, the combination of conventional prognostic factor (histological grade) and biochemical factors (cath D and c-erbB-2 oncoprotein) enabled us to identify, in this preliminary study, a subgroup of patients having an increased risk of relapse in a group (node-negative patients with low histological grade tumors) considered as good prognosis.

Emergency interruption of the inferior vena cava: a debatable issue.

In spite of improvements in the diagnosis and treatment of thromboembolic disease, pulmonary embolism continues to be a major cause of morbidity and mortality. Anticoagulation remains the preferred therapy for deep venous thrombosis; however, this form of treatment is either ineffective or contraindicated for some patients. For these patients, partial interruption of the inferior vena cava via percutaneous filter placement has become the procedure of choice to protect against fatal pulmonary embolism. We described in this paper results obtained with the available permanent filters and complications of these filters described in the literature. We highlighted the interest of temporary filters in patients whose thromboembolic risk is temporary, finally we insist on recognised indications for vena cava filters when anticoagulation is contraindicated or ineffective.

Multicentre study of thyroid nodules in patients with Graves' disease.

BACKGROUND: The association of Graves' disease with thyroid nodules and thyroid carcinoma is rarely reported. The incidence seems to be increasing according to recent literature. The aim of this multicentre study was to review patients who had surgery for Graves' disease associated with thyroid nodules, and to evaluate the risk of thyroid carcinoma. METHODS: A retrospective study was made of 557 consecutive patients who underwent operation for Graves' disease between 1991 and 1997 in five endocrine surgery departments. Each patient underwent clinical, biochemical, ultrasonographic and scintigraphic evaluation. None of the patients had had previous radioactive iodine therapy or external irradiation. Surgery consisted of either a subtotal or total thyroidectomy. RESULTS: Nodules were observed before operation in 140 patients (25.1 per cent). Thyroid carcinoma was diagnosed in 21 patients (15.0 per cent), always inside a nodule. The incidence of thyroid carcinoma associated with Graves' disease was 3.8 per cent (21 of 557 patients): 20 papillary and one follicular carcinoma. The carcinoma was multifocal in two patients. Tumour diameter ranged from 2 to 25 mm. A nodule was palpable in four patients. CONCLUSION: This multicentre study of patients having thyroidectomy for Graves' disease showed that 3.8 per cent had a carcinoma; the rate of carcinoma in cold nodules was 15.0 per cent. Surgery should be advised in any patient with Graves' disease and a thyroid nodule; the operation should be total thyroidectomy.

The role of polyester patch angioplasty in carotid endarterectomy: a multicenter study.

The objectives of this study were to examine the morphology, restenosis, dilatation, and possible complications of polyester collagen impregnated carotid patches. Between March 1994 and January 1995, 207 patients (56 females and 151 males) undergoing 221 carotid endarterectomies (CE) with a collagen-impregnated knitted polyester patch were enrolled in a European prospective multicenter study. Patches were used for arteries deemed to be smaller than usual by visual inspection. General anesthesia was used in 201 procedures (91%), and a shunt was used in 76 procedures (34.4%). One hundred fourteen CE (51.6%) were checked by a perioperative arteriography or angioscopy. The diameter of the internal carotid artery (ICA) and carotid bulb (CB) were measured by duplex scan both preoperatively and every 6 months during follow-up. The main end point was carotid occlusion or restenosis, defined as a stenosis of 50% or more according to NASCET criteria. Carotid polyester-impregnated patches appear to be reliable. The patch was easy to cut and suture, and hemostasis was obtained immediately. No rupture occurred. However, the higher restenosis rate in women may restrict the use of polyester patch to men.

Early carotid endarterectomy after a nondisabling stroke: a prospective study.

On the recommendation of several studies, carotid endarterectomy (CEA) should be delayed for at least 6 weeks in patients suffering an acute nondisabling stroke. Our objective was to determine if these patients could be safely operated on earlier, thus decreasing the risk of a recurrent stroke prior to surgery. This prospective study, carried out from January 1990 to December 1997, included 72 consecutive patients having a nondisabling hemispheric stroke with severe ipsilateral carotid stenosis (NASCET 70-99%). All patients underwent CEA within 15 days of stroke onset. Patients were considered to have a nondisabling hemispheric stroke if (1) symptoms of hemispheric ischemia persisted longer than 24 hr and (2) the resulting deficit caused no major impairment in their everyday activities. All patients were examined by a neurologist prior to carotid angiography and contrast CT scan. Hemorrhage seen on the initial CT scan eliminated the patient from the study. If the CT scan with contrast injection was negative, patients underwent magnetic resonance imaging. CEA was performed under general anesthesia with intraluminal shunting. All patients had a postoperative duplex scan and yearly follow-up by a neurologist and a surgeon, with a duplex scan of the carotid arteries. Mean follow-up was 53 months. Our study shows that CEA can be performed relatively safely within 15 days following an acute nondisabling stroke. The arbitrary 6-week delay for CEA may unnecessarily expose patients with high-grade stenosis to a recurrent stroke, which could be prevented by earlier surgery.

Accuracy of the main Doppler methods for evaluating the degree of carotid stenoses (continuous wave, pulsed wave, and color Doppler).

OBJECTIVE: To compare the accuracy of the main Doppler methods for quantifying the degree of carotid stenoses in 133 patients. METHOD: seven parameters were measured: maximum velocity (V.max) inside the stenosis (by pulsed wave [PW]), grade and index of spectral disturbance (STI) at the outlet of the stenosis (by PW and continuous wave [CW]), ratio of velocities I(IC/CC) in the internal and common carotid (by PW), and ratio of vessel cross-section and residual lumen area (%Color) inside the stenosis (color Doppler). The reference methods were the grades of spectral disturbance and the STI (by CW), already validated against endarterectomy specimens. CONCLUSION: For poststenosis measurements, a high correlation was found between the grades or STI measured by PW and CW (reference method). The measurement of these parameters was easier in PW mode. For intrastenotic velocity, the increase in V.max was not proportional to the degree of stenosis, and V.max showed large fluctuations for the same degree of stenosis. I(IC/CC) also showed large fluctuations for the same degree of stenosis. The correlation was poor for these two parameters, which could only be used for detecting two groups of stenosis: >75% or >90% in area. Color Doppler (conventional and power) routinely overestimated the degree of stenosis by 10%-15% but correlated better with the reference method and was more accurate and reproducible than V.max. A special procedure can be used to avoid this overestimation and improve the accuracy of the color Doppler.

[Basedow's disease and thyroid nodules. A common association]. / Maladie de Basedow et nodules thyroïdiens. Une association non exceptionnelle.

The frequency of thyroid cancer associated with Graves' disease is a controversial subject. The authors retrospectively studied 110 consecutive patients operated for Graves' disease between 1991 and 1996. Each patient was evaluated by clinical and laboratory examination, ultrasound and isotope scan. None of the patients had a history of external beam cervical radiotherapy or radioactive iodine. All patients were treated by total or subtotal thyroidectomy. Thyroid nodules were detected in 28 patients (24 women, 4 men), and 6 of them corresponded to papillary carcinoma (5.5% of patients with Graves' disease and 21.4% of patients with Graves' disease associated with nodules). These data suggest the value of surgery in Graves' disease associated with thyroid nodules.

[A comparative study of the Doppler methods for evaluation of the degree of carotid artery stenosis. Continuous, pulsed, color Doppler]. / Etude comparative des méthodes Doppler pour l'évaluation du degré des sténoses carotidiennes. Doppler continu, pulsé, couleur.

OBJECTIVE: Compare various Doppler methods for the quantification of the degree of stenosis on 85 patients. METHOD: the following parameters were measured: maximal velocity (Vmax) inside the stenosis (PW), grades of spectral disturbances at the outlet of the stenosis (PW-CW), index of spectral disturbance (STI) at the outlet of the stenosis (PW-CW), ratio of velocities I(IC/CC) in internal and common carotid (PW), ratio of vessel cross section and residual lumen area (% STEN) by color Doppler. The reference method was the Grades of spectral disturbance and the index of stenosis measured post stenosis. (Method validated against angiography and pieces of endarterectomy.) The following comparisons were done; grades and STI by CW against grades and STI by PW, Vmax (PW) against grade and STI, % STEN (color) against grade and STI, % STEN (color) against Vmax (PW), I(IC/CC) (PW) against grade and STI, I(IC/CC) (PW) against Vmax. CONCLUSION: (a) grades or stenosis index : showed the best reproductibility; (b) a high correlation was found between the grades or stenosis index post stenosis measured by CW or PW; (c) Vmax was not proportional to the stenosis degree and showed large fluctuations for the same stenosis degree; (d) the I(IC/CC) showed large fluctuations for the same stenosis degree, the correlation was poor for this velocity ratio. Both Vmax and I(IC/CC) allow to detect only 2 groups of stenosis > 75% or > 90% in area; (e) color doppler over-estimate stenosis degree by approximately 20% but was more accurate and reproducible than Vmax. An appropriate procedure was designed to avoid this over estimation.

[Thyroid nodules associated with Graves' disease: another argument for surgical treatment]. / Nodules thyroïdiens associés: un argument de plus en faveur du traitement chirurgical de la maladie de Basedow.

Much controversy surrounds the incidence of thyroid cancer associated with Graves' disease. We studied retrospectively 110 patients operated on for Graves' disease between 1991 and 1996. Each patient was evaluated by clinical exam, biological test, ultrasonography, and scintigraphy. No patient had a history of prior external radiation to the head or the neck. All patients underwent near total or total thyroidectomy. Nodules in the thyroid were detected in 28 cases: 6 were papillary carcinoma (5.5% from patients with Graves' disease, and 21.4% from patients with Graves' disease associated with thyroid nodules). These data suggest interest of surgery in Graves' disease associated with thyroid nodules.

Chemiluminescence immunoassay of thyrotropin with acridinium-ester-labeled antibody evaluated and compared with two other immunoassays.

A new chemiluminometric immunoassay of thyrotropin (TSH) involves antibody labeled with acridinium ester ("Magic Lite System," Ciba Corning Diagnostic Corp.). The assay is rapid, with two incubations totaling 2.5 h, requires two standards per run, and takes 10 s per sample for the quantification step. Analytical performance, within- and between-run reproducibilities, and linearity were excellent. The detection limit is 0.04 milli-int. unit/L. Results correlated well with those obtained by immunoradiometric assay (RIA-gnost hTSH, Hoechst-Behring) and immunofluorometric assay (hTSH Delfia, LKB): r = 0.975. TSH measurements in 32 euthyroid subjects ranged from 0.4 to 4.8 milli-int. units/L (mean 1.35 milli-int. units/L). TSH values for 51 hypothyroid and subclinically hypothyroid patients ranged from 2 to 65 milli-int. units/L. TSH values for 33 hyperthyroid patients (less than 0.14 milli-int. unit/L, less than 0.04 milli-int. unit/L in 16 of the 33) were clearly lower than for most untreated euthyroid subjects. For 169 other individuals whose thyroid function was being routinely assessed. TSH ranged from 0.4 to 4.8 milli-int. units/L, three had TSH less than 0.14 milli-int. unit/L, and four had TSH between 0.14 and 0.4 milli-int. unit/L. This system is as efficient and reliable for screening for thyroid function as the two comparison systems.

[Quantification of carotid atheroma, by vascular ultrasonics and spectral analysis, after myocardial infarction. Apropos of 80 cases]. / Quantification de l'athérome carotidien, par l'échotomographie vasculaire et l'analyse spectrale, après infarctus du myocarde. A propos de 80 observations.

A prospective study of carotid artery atheroma by vascular echotomography and spectral analysis was performed in 40 patients with myocardial infarction and 40 control subjects. Carotid artery atheroma was commoner in the group of patients with myocardial infarction (72.5% +/- 6.8%), earlier (9 years), more commonly bilateral (37.5% +/- 7.6%) and more stenotic (32.5% +/- 7.4%) than in the control group (p less than 0.000a, p less than 0.0001 and p less than 0.002, respectively). The severity of carotid artery atheroma correlated with the site of coronary artery disease; the following significant relationships were found: stenosing 40% and/or bilateral carotid atherosclerosis and left anterior descending disease (p less than 0.02); carotid atherosclerosis and double or triple vessel disease (p less than 0.05). The authors conclude that detection of carotid artery atheroma after myocardial infarction is valuable for two reasons: it gives an indication as to the severity of the coronary disease; carotid endarterectomy may be considered at the same time as coronary artery bypass surgery.

[Detection and quantification of carotid atheroma. Respective value of vascular ultrasonography, spectrum analysis and digital intravenous angiography]. / Dépistage et quantification de l'athérome carotidien. Intérêts respectifs de l'échotomographie vasculaire, de l'analyse spectrale et de l'angiographie numérisée intraveineuse.

This retrospective study involved 37 subjects who were examined by means of intravenous digitalised angiography, vascular ultrasonography and spectral analysis of the Doppler signal. The last two examinations were found to give the most precise images and functional information. The concordances between angiography and ultrasonography on the one hand and spectral analysis on the other were 82 and 90 per cent. The authors have established a protocol in order to limit and systematize these examinations during screening for carotid atheroma: the risk factors are weighted; a score is obtained by summation; depending on the value of this score and the patient's age, the investigation procedure is pursued or not. The sequence always consists of ultrasonography followed by spectral analysis when plaque is detected and by angiography when the plaque is stenotic or ulcerated. In symptomatic patients, ultrasonography and digitalised angiography are performed routinely.